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Sample records for buffy coat preparations

  1. Preparation of leukocyte-poor platelet concentrates from buffy coats. I. Special inserts for centrifuge cups

    NARCIS (Netherlands)

    Pietersz, R. N.; Reesink, H. W.; Dekker, W. J.; Fijen, F. J.

    1987-01-01

    A special insert was developed for centrifuge cups in order to prepare leukocyte-poor platelet concentrates from buffy coats by using quadruple citrate phosphate dextrose-saline adenine glucose mannitol systems from different manufacturers. Each centrifuge cup could contain up to 4 sets of double

  2. White blood cell fragments in platelet concentrates prepared by the platelet-rich plasma or buffy-coat methods

    NARCIS (Netherlands)

    Dijkstra-Tiekstra, M. J.; van der Schoot, C. E.; Pietersz, R. N. I.; Reesink, H. W.

    2005-01-01

    BACKGROUND AND OBJECTIVES: White blood cell (WBC) fragments in platelet concentrates (PCs) may induce allo-immunization in the recipient. MATERIALS AND METHODS: As the level of WBC fragments can differ between PCs produced using different methods, we compared PCs prepared by using the buffy-coat

  3. Alterations in cytoskeletal organization and tyrosine phosphorylation in platelet concentrates prepared by the buffy coat method.

    Science.gov (United States)

    Estebanell, E; Díaz-Ricart, M; Escolar, G; Lozano, M; Mazzara, R; Ordinas, A

    2000-05-01

    Numerous morphologic and biochemical changes occurring during platelet storage may result in the impairment of platelet function. The effect of preparation and storage conditions on platelet function was analyzed through evaluation of cytoskeletal organization and signaling mechanisms involved in the activation of platelets by thrombin. Samples of platelets prepared by the buffy coat method were obtained before and after the platelet concentrates were prepared during storage for 1, 3, and 5 days. Thrombin-induced aggregation was monitored, and changes in the organization of proteins in the cytoskeleton were analyzed by gel electrophoresis. For the analysis of tyrosine phosphorylation, proteins were transferred to nitrocellulose membranes and probed with a specific antibody. The aggregation and the cytoskeletal organization induced by thrombin activation were markedly impaired immediately after preparation of platelet concentrates, although they normalized after the first 24 hours of storage and decreased progressively after 3 days of storage. Results in tyrosine phosphorylation paralleled those obtained with cytoskeletal organization, except for samples obtained immediately after processing to obtain platelet concentrates. These data indirectly suggest that the stress induced by the preparation method has an activating effect on platelet function that may imply a delayed platelet response to further stimuli. This effect may result in a deficient redistribution of signaling molecules within platelets.

  4. Intralesional autotherapy of cutaneous leishmaniasis with buffy coat cells: cytological findings

    DEFF Research Database (Denmark)

    Dabiri, S; Meymandi, S S; Hayes, M M

    2000-01-01

    The skin lesions of five patient volunteers with dry-type cutaneous leishmaniasis were treated by intralesional injection of auto-leukocytes prepared from buffy coat of the patient's own blood. Giemsa stained, air-dried cytological smear preparations were prepared from scrapings taken from...... the potential for intralesional autotherapy with buffy coat in dry-type cutaneous leishmaniasis....

  5. The 'cherry buffy-coat syndrome', a cause of decreased platelet yield in platelet concentrates obtained from buffy-coats.

    Science.gov (United States)

    Rebulla, P; Smacchia, C; Greppi, N; Porretti, L; Lopa, R; Cernuschi, M; Sirchia, G

    2001-01-01

    A large number of European blood centres, including our own, use the buffy-coat method for platelet production. In this article we describe a previously unnoticed phenomenon shown by a proportion of buffy-coats, which display an unusually bright cherry colour and low platelet counts. We performed bacterial cultures, platelet counts, pO2, pCO2 and pH, and evaluated platelet activation by flow cytometry in cherry versus normal-colour (control) buffy-coats. In addition, we compared donor characteristics in the two groups and platelet counts in the packed red blood cells (RBC) obtained from the original donations. Finally, we monitored the frequency of cherry buffy-coats in the bags of three manufacturers, and determined the concordance rate of two trained technicians in detecting cherry buffy-coats. Bacterial cultures were negative. Cherry buffy-coats contained significantly fewer platelets, more O2, less CO2 and had a significantly higher pH than normal buffy coats. Platelet activation was slightly higher in cherry buffy-coats. RBC from donations yielding cherry buffy-coats contained a significantly higher number of platelets than controls. Donor characteristics were not significantly different. Cherry buffy-coats were significantly more frequent with bags from one manufacturer (24%) than from others (9% and 11.6%). The concordance study showed excellent agreement. Our hypothesis is that the cherry colour is caused by O2 accumulation in buffy-coats with low platelet counts. The latter may be caused by platelet activation and aggregation during blood processing. Further work is needed to determine the cause of this phenomenon, its frequency in different laboratories and means to prevent it.

  6. Quality assessment of platelet concentrates prepared by platelet rich plasma-platelet concentrate, buffy coat poor-platelet concentrate (BC-PC and apheresis-PC methods

    Directory of Open Access Journals (Sweden)

    Singh Ravindra

    2009-01-01

    Full Text Available Background: Platelet rich plasma-platelet concentrate (PRP-PC, buffy coat poor-platelet concentrate (BC-PC, and apheresis-PC were prepared and their quality parameters were assessed. Study Design: In this study, the following platelet products were prepared: from random donor platelets (i platelet rich plasma - platelet concentrate (PRP-PC, and (ii buffy coat poor- platelet concentrate (BC-PC and (iii single donor platelets (apheresis-PC by different methods. Their quality was assessed using the following parameters: swirling, volume of the platelet concentrate, platelet count, WBC count and pH. Results: A total of 146 platelet concentrates (64 of PRP-PC, 62 of BC-PC and 20 of apheresis-PC were enrolled in this study. The mean volume of PRP-PC, BC-PC and apheresis-PC was 62.30±22.68 ml, 68.81±22.95 ml and 214.05±9.91 ml and ranged from 22-135 ml, 32-133 ml and 200-251 ml respectively. The mean platelet count of PRP-PC, BC-PC and apheresis-PC was 7.6±2.97 x 1010/unit, 7.3±2.98 x 1010/unit and 4.13±1.32 x 1011/unit and ranged from 3.2-16.2 x 1010/unit, 0.6-16.4 x 1010/unit and 1.22-8.9 x 1011/unit respectively. The mean WBC count in PRP-PC (n = 10, BC-PC (n = 10 and apheresis-PC (n = 6 units was 4.05±0.48 x 107/unit, 2.08±0.39 x 107/unit and 4.8±0.8 x 106/unit and ranged from 3.4 -4.77 x 107/unit, 1.6-2.7 x 107/unit and 3.2 - 5.2 x 106/unit respectively. A total of 26 units were analyzed for pH changes. Out of these units, 10 each were PRP-PC and BC-PC and 6 units were apheresis-PC. Their mean pH was 6.7±0.26 (mean±SD and ranged from 6.5 - 7.0 and no difference was observed among all three types of platelet concentrate. Conclusion: PRP-PC and BC-PC units were comparable in terms of swirling, platelet count per unit and pH. As expected, we found WBC contamination to be less in BC-PC than PRP-PC units. Variation in volume was more in BC-PC than PRP-PC units and this suggests that further standardization is required for preparation of BC

  7. Molecular diagnosis of toxoplasmosis: value of the buffy coat for the detection of circulating Toxoplasma gondii.

    Science.gov (United States)

    Brenier-Pinchart, Marie-Pierre; Capderou, Elodie; Bertini, Rose-Laurence; Bailly, Sébastien; Fricker-Hidalgo, Hélène; Varlet-Marie, Emmanuelle; Murat, Jean-Benjamin; Sterkers, Yvon; Touafek, Fériel; Bastien, Patrick; Pelloux, Hervé

    2015-08-01

    Early detection of Toxoplasma tachyzoites circulating in blood using PCR is recommended for immunosuppressed patients at high risk for disseminated toxoplasmosis. Using a toxoplasmosis mouse model, we show that the sensitivity of detection is higher using buffy coat isolated from a large blood volume than using whole blood for this molecular monitoring. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. A new cellulose acetate filter to remove leukocytes from buffy-coat-poor red cell concentrates

    NARCIS (Netherlands)

    Pietersz, R. N.; Dekker, W. J.; Reesink, H. W.

    1989-01-01

    Transfusion of leukocyte-free red cell concentrates (RCC) prevents or delays HLA immunization in multitransfused patients. We investigated a new cellulose acetate filter which was recently introduced to remove leukocytes from buffy-coat-poor RCC. It was found that the filtration time was only 10 min

  9. In vitro cell quality of buffy coat platelets in additive solution treated with pathogen reduction technology

    DEFF Research Database (Denmark)

    Ostrowski, Sisse R; Bochsen, Louise; Salado-Jimena, José A

    2010-01-01

    Pathogen reduction technologies (PRTs) may induce storage lesion in platelet (PLT) concentrates. To investigate this, buffy coat PLTs (BCPs) in PLT additive solution (AS; SSP+) with or without Mirasol PRT (CaridianBCT Biotechnologies) were assessed by quality control tests and four-color flow...

  10. Label-free capture of breast cancer cells spiked in buffy coats using carbon nanotube antibody micro-arrays

    Science.gov (United States)

    Khosravi, Farhad; Trainor, Patrick; Rai, Shesh N.; Kloecker, Goetz; Wickstrom, Eric; Panchapakesan, Balaji

    2016-04-01

    We demonstrate the rapid and label-free capture of breast cancer cells spiked in buffy coats using nanotube-antibody micro-arrays. Single wall carbon nanotube arrays were manufactured using photo-lithography, metal deposition, and etching techniques. Anti-epithelial cell adhesion molecule (EpCAM) antibodies were functionalized to the surface of the nanotube devices using 1-pyrene-butanoic acid succinimidyl ester functionalization method. Following functionalization, plain buffy coat and MCF7 cell spiked buffy coats were adsorbed on to the nanotube device and electrical signatures were recorded for differences in interaction between samples. A statistical classifier for the ‘liquid biopsy’ was developed to create a predictive model based on dynamic time warping to classify device electrical signals that corresponded to plain (control) or spiked buffy coats (case). In training test, the device electrical signals originating from buffy versus spiked buffy samples were classified with ˜100% sensitivity, ˜91% specificity and ˜96% accuracy. In the blinded test, the signals were classified with ˜91% sensitivity, ˜82% specificity and ˜86% accuracy. A heatmap was generated to visually capture the relationship between electrical signatures and the sample condition. Confocal microscopic analysis of devices that were classified as spiked buffy coats based on their electrical signatures confirmed the presence of cancer cells, their attachment to the device and overexpression of EpCAM receptors. The cell numbers were counted to be ˜1-17 cells per 5 μl per device suggesting single cell sensitivity in spiked buffy coats that is scalable to higher volumes using the micro-arrays.

  11. Label-free capture of breast cancer cells spiked in buffy coats using carbon nanotube antibody micro-arrays.

    Science.gov (United States)

    Khosravi, Farhad; Trainor, Patrick; Rai, Shesh N; Kloecker, Goetz; Wickstrom, Eric; Panchapakesan, Balaji

    2016-04-01

    We demonstrate the rapid and label-free capture of breast cancer cells spiked in buffy coats using nanotube-antibody micro-arrays. Single wall carbon nanotube arrays were manufactured using photo-lithography, metal deposition, and etching techniques. Anti-epithelial cell adhesion molecule (EpCAM) antibodies were functionalized to the surface of the nanotube devices using 1-pyrene-butanoic acid succinimidyl ester functionalization method. Following functionalization, plain buffy coat and MCF7 cell spiked buffy coats were adsorbed on to the nanotube device and electrical signatures were recorded for differences in interaction between samples. A statistical classifier for the 'liquid biopsy' was developed to create a predictive model based on dynamic time warping to classify device electrical signals that corresponded to plain (control) or spiked buffy coats (case). In training test, the device electrical signals originating from buffy versus spiked buffy samples were classified with ∼100% sensitivity, ∼91% specificity and ∼96% accuracy. In the blinded test, the signals were classified with ∼91% sensitivity, ∼82% specificity and ∼86% accuracy. A heatmap was generated to visually capture the relationship between electrical signatures and the sample condition. Confocal microscopic analysis of devices that were classified as spiked buffy coats based on their electrical signatures confirmed the presence of cancer cells, their attachment to the device and overexpression of EpCAM receptors. The cell numbers were counted to be ∼1-17 cells per 5 μl per device suggesting single cell sensitivity in spiked buffy coats that is scalable to higher volumes using the micro-arrays.

  12. Randomised comparison of leucocyte-depleted versus buffy-coat-poor blood transfusion and complications after colorectal surgery

    DEFF Research Database (Denmark)

    Jensen, L S; Kissmeyer-Nielsen, P; Wolff, B

    1996-01-01

    surgery were randomised to receive buffy-coat poor (n = 299) or filtered leucocyte-depleted red-cells (n = 290) when transfusion was indicated. 260 patients actually received blood transfusion. Three patients were excluded from analysis. FINDINGS: The 142 patients randomised to and transfused with buffy......-coat-poor blood had a significantly higher frequency of wound infections and intra-abdominal abscesses than the 155 patients who were allocated to this group but who were not transfused. (12 vs 1%, p ... higher frequency of wound infections and intra-abdominal abscesses than the 118 randomised to and receiving leucocyte-depleted blood (12 vs 0%, p

  13. Hemostatic function of buffy coat platelets in additive solution treated with pathogen reduction technology

    DEFF Research Database (Denmark)

    Ostrowski, Sisse R; Bochsen, Louise; Windeløv, Nis Agerlin

    2011-01-01

    BACKGROUND: Pathogen reduction technologies (PRTs) may influence the hemostatic potential of stored platelet (PLT) concentrates. To investigate this, buffy coat PLTs (BCPs) stored in PLT additive solution (SSP+) with or without Mirasol PRT treatment (CaridianBCT Biotechnologies) were compared...... by functional hemostatic assays. STUDY DESIGN AND METHODS: We performed in vitro comparison of PRT (PRT-BCP) and control pooled-and-split BCPs (CON-BCP) after 2, 3, 6, 7, and 8 days' storage. Hemostatic function was evaluated with thrombelastography (TEG) and impedance aggregometry (Multiplate), the latter also...... in a sample matrix (Day 2) with or without addition of red blood cells (RBCs), control plasma, and/or PRT-treated plasma. RESULTS: PRT treatment of 8-day-stored BCPs influenced clot formation (TEG) minimally, with reductions in maximum clot strength (maximum amplitude, p = 0.014) but unchanged initial fibrin...

  14. A comparison of peripheral blood and buffy coat smear examination for the prediction of bone marrow relapse of acute lymphoblastic leukaemia in childhood.

    Science.gov (United States)

    Franklin, I M

    1983-02-01

    In an attempt to see if buffy coat smear examination might be an alternative to bone marrow aspiration for predicting relapse, 98 consecutive bone marrow aspirates from 96 children with acute lymphoblastic leukaemia were examined blind with buffy coat and peripheral blood from the same patients. The 28 bone marrow aspirates from children no longer on treatment were all normal, and routine aspirates would appear unjustified in these patients. Eight of the remaining marrows showed relapse, but only three were not predicted from the peripheral blood and buffy coat. In no case was buffy coat superior to peripheral blood in the detection of bone marrow relapse. Routine bone marrow aspirates are an inefficient way of diagnosing relapse in acute lymphoblastic leukaemia in childhood, despite their precision, and a prospective study is needed to determine their value.

  15. A comparison of peripheral blood and buffy coat smear examination for the prediction of bone marrow relapse of acute lymphoblastic leukaemia in childhood.

    OpenAIRE

    Franklin, I M

    1983-01-01

    In an attempt to see if buffy coat smear examination might be an alternative to bone marrow aspiration for predicting relapse, 98 consecutive bone marrow aspirates from 96 children with acute lymphoblastic leukaemia were examined blind with buffy coat and peripheral blood from the same patients. The 28 bone marrow aspirates from children no longer on treatment were all normal, and routine aspirates would appear unjustified in these patients. Eight of the remaining marrows showed relapse, but ...

  16. Characterization of buffy coat-derived granulocytes for clinical use: a comparison with granulocyte colony-stimulating factor/dexamethasone-pretreated donor-derived products.

    Science.gov (United States)

    van de Geer, A; Gazendam, R P; Tool, A T J; van Hamme, J L; de Korte, D; van den Berg, T K; Zeerleder, S S; Kuijpers, T W

    2017-02-01

    Buffy coat-derived granulocytes have been described as an alternative to the apheresis product from donors pretreated with dexamethasone and granulocyte colony-stimulating factor (G-CSF). The latter is - dependent on the local and national settings - obtained following a demanding and time-consuming procedure, which is undesirable in critically ill septic patients. In contrast, buffy coat-derived products have a large volume and are often heavily contaminated with red cells and platelets. We developed a new pooled buffy coat-derived product with high purity and small volume, and performed a comprehensive functional characterization of these granulocytes. We pooled ten buffy coats following the production of platelet concentrates. Saline 0·9% was added to decrease the viscosity and the product was split into plasma, red cells and a 'super' buffy coat. Functional data of the granulocytes were compared to those obtained with granulocytes from healthy controls and G-CSF/dexamethasone-pretreated donors. Buffy coat-derived granulocytes showed adhesion, chemotaxis, reactive oxygen species production, degranulation, NETosis and in vitro killing of Staphylococcus aureus, Escherichia coli and Aspergillus species comparable to control and G-CSF/dexamethasone-derived granulocytes. Candida killing was superior compared to G-CSF/dexamethasone-derived granulocytes. Immunophenotyping was normal; especially no signs of activation in the buffy coat-derived granulocytes were seen. Viability was reduced. Buffy coats are readily available in the regular blood production process and would take away the concerns around the apheresis product. The product described appears a promising alternative for transfusion purposes. © 2017 International Society of Blood Transfusion.

  17. Treatment of buffy coat platelets in platelet additive solution with the mirasol(®) pathogen reduction technology system.

    Science.gov (United States)

    Castrillo, Azucena; Cardoso, Marcia; Rouse, Lindsay

    2013-02-01

    The Mirasol pathogen reduction technology (PRT) system uses riboflavin and ultraviolet light and is currently approved and used in Europe for the treatment of platelets and plasma. Mirasol treatment is intended to reduce the infectious pathogen load and to inactivate leukocytes in blood products. Our objective was to evaluate buffy coat platelet concentrates (BCPCs) prepared with platelet additive solution (PAS) and treated with the Mirasol system and to examine the effects on platelet cell quality during storage. 26 BCPCs were prepared and split, creating 13 paired control and test units. The test units were treated with the Mirasol system and the platelet quality was assessed in all units over 7 days of storage. All products met the incoming specifications for Mirasol treatment, and the pH of all Mirasol-treated BCPCs in PAS met the requirements of the Council of Europe guidelines throughout storage. Analysis of lactate production and glucose consumption rates, CD62p expression and cytokines indicates enhanced cellular metabolism in treated platelets, but the levels were within previously published ranges. While Mirasol-treated BCPCs in PAS had increased metabolism and activation compared to controls, the results indicate that these units can be stored for 7 days with acceptable cell quality.

  18. Quality control of buffy coat removed red cell concentrates--a Croatian experience.

    Science.gov (United States)

    Vuk, T; Očić, T; Patko, M Strauss; Jukić, I

    2014-12-01

    Results are presented of the statistical quality control of red cell concentrate buffy coat removed in additive solution (RCC/BC/AS) and red cell concentrate buffy coat removed and leucoreduced in additive solution (RCC/BC/LR/AS) produced at the Croatian Institute of Transfusion Medicine during an 8-year period (2005-2012). The aim was to assess quality conformity of these products with specified requirements, as well as the suitability and justification of current regulations on the minimal quality requirements. The measurements of all the study parameters of the products analysed are expressed using descriptive statistics and graphs showing the distributions of observed parameters. In RCC/BC/AS, the mean (± SD) volume was 279 ± 17 mL; haematocrit, 0.60 ± 0.03 L L(-1); haemoglobin content, 55 ± 5 g; leucocyte count, 0.65 ± 0.41 × 10(9); and haemolysis at expiry date, 0.16 ± 0.13%. In RCC/BC/LR/AS (post-production filtration), the mean (± SD) volume was 255 ± 14 mL; haematocrit, 0.60 ± 0.02 L L(-1); haemoglobin content, 51 ± 4 g; leucocyte count, 0.11 ± 0.16 × 10(6); and haemolysis at expiry date, 0.11 ± 0.07%. In RCC/BC/LR/AS (inline filtration), the mean (± SD) volume was 254 ± 15 mL; haematocrit, 0.61 ± 0.02 L L(-1); haemoglobin content, 51 ± 5 g; leucocyte count, 0.04 ± 0.06 × 10(6); and haemolysis at expiry date, 0.16 ± 0.10%. The standards were just met for leucocyte count in RCC/BC/AS (90%), whereas for all other parameters satisfactory results were obtained in at least 99% of products analysed. Total incidence of bacterial contamination was 0.23% for all products. Results of the RCC/BC/AS and RCC/BC/LR/AS quality control showed very high conformity with the specified requirements in the majority of study parameters, suggesting that the current requirements could be redefined and improved at the institutional level. © 2014 British Blood Transfusion Society.

  19. Pathogen reduction treatment of buffy coat platelet concentrates in additive solution induces proapoptotic signaling.

    Science.gov (United States)

    Reid, Samantha; Johnson, Lacey; Woodland, Narelle; Marks, Denese C

    2012-10-01

    Pathogen reduction technology (PRT) can potentially reduce the risk of transfusion-transmitted infections. However, PRT treatment of platelet (PLT) concentrates also results in reduced PLT quality and increased markers of apoptosis during storage. The aim of this study was to investigate changes to the expression and activation of proteins involved in apoptosis signaling. Samples from riboflavin and ultraviolet light PRT-treated and untreated (control) buffy coat-derived PCs in 70% SSP+ and 30% plasma were taken on Days 1, 5, and 7 of storage. Phosphatidylserine (PS) exposure, expression of Bcl-2 family proteins, cytochrome c release, and cleavage of caspase-3 and caspase-3 substrates were analyzed using flow cytometry and Western blotting. Compared to untreated controls, markers of apoptosis signaling were increased after PRT and subsequent storage. PS exposure on the PLT outer membrane was significantly higher after PRT on Days 5 and 7 of storage (p controls. This study demonstrated an increase in proapoptotic signaling during PLT storage, which was exacerbated by PRT. Many of these differences emerged outside the current 5-day storage period. These changes may not currently influence PLT transfusion quality, but will need to be carefully evaluated when considering extending PLT storage beyond 5 days. © 2012 American Association of Blood Banks.

  20. Hemostatic function of buffy coat platelets in additive solution treated with pathogen reduction technology.

    Science.gov (United States)

    Ostrowski, Sisse R; Bochsen, Louise; Windeløv, Nis A; Salado-Jimena, José A; Reynaerts, Inge; Goodrich, Raymond P; Johansson, Pär I

    2011-02-01

    Pathogen reduction technologies (PRTs) may influence the hemostatic potential of stored platelet (PLT) concentrates. To investigate this, buffy coat PLTs (BCPs) stored in PLT additive solution (SSP+) with or without Mirasol PRT treatment (CaridianBCT Biotechnologies) were compared by functional hemostatic assays. We performed in vitro comparison of PRT (PRT-BCP) and control pooled-and-split BCPs (CON-BCP) after 2, 3, 6, 7, and 8 days' storage. Hemostatic function was evaluated with thrombelastography (TEG) and impedance aggregometry (Multiplate), the latter also in a sample matrix (Day 2) with or without addition of red blood cells (RBCs), control plasma, and/or PRT-treated plasma. PRT treatment of 8-day-stored BCPs influenced clot formation (TEG) minimally, with reductions in maximum clot strength (maximum amplitude, p = 0.014) but unchanged initial fibrin formation (R), clot growth rate (α), and fibrinolysis resistance. In the absence of RBCs and plasma, PRT impaired aggregation (Multiplate) in stored BCPs, with reduced aggregation against thrombin receptor activating peptide-6 (p Addition of RBCs and PRT-treated or untreated plasma to PRT-BCP and CON-BCP, respectively, enhanced aggregation in both groups. Mirasol PRT treatment of BCPs had a minimal influence on clot formation, whereas aggregation in the absence of RBCs and plasma was significantly reduced. Addition of RBCs and plasma increased agonist-induced responses resulting in comparable aggregation between PRT-BCP and CON-BCP. The clinical relevance for PLT function in vivo of these findings will be investigated in a clinical trial. © 2010 American Association of Blood Banks.

  1. In vitro cell quality of buffy coat platelets in additive solution treated with pathogen reduction technology.

    Science.gov (United States)

    Ostrowski, Sisse R; Bochsen, Louise; Salado-Jimena, José A; Ullum, Henrik; Reynaerts, Inge; Goodrich, Raymond P; Johansson, Pär I

    2010-10-01

    Pathogen reduction technologies (PRTs) may induce storage lesion in platelet (PLT) concentrates. To investigate this, buffy coat PLTs (BCPs) in PLT additive solution (AS; SSP+) with or without Mirasol PRT (CaridianBCT Biotechnologies) were assessed by quality control tests and four-color flow cytometry. In vitro comparison of PRT and control pooled-and-split BCPs after 2, 3, 6, 7, and 8 days of storage was made. PLT concentration, count per unit, swirl, metabolism, activation (CD62P, PAC1, CD42b/GPIb, CD63, CD40L/CD154, CD40, annexin V), and microparticle, sCD40L, and sCD62P release were evaluated. PRT induced a minor initial PLT loss (Day 2 [mean±SD], 302×10(9) ±44×10(9) PLTs/unit vs. 325× 10(9) ±46×10(9) PLTs/unit; pcontrol BCP. Swirling was comparable and declined with similar rates in PRT-treated and control BCPs during storage. PRT enhanced PLT metabolism and activation, evidenced by lower pH(22) ; increased glucose consumption and lactate production rates (p<0.01); early increases in CD62P-, PAC1-, CD63-, CD40L-, CD40-, and annexin V-positive PLTs; reduced GPIb expression; and enhanced release of PLT-derived MPs and sCD40L (all p<0.05). CD62P and PAC1 expression changed with different kinetics during storage and varying GPIb expression was displayed within the CD62P/PAC1-positive PLT subsets. PRT treatment of BCP in AS induced a minor initial PLT loss and enhanced metabolism and PLT activation. The clinical relevance for PLT function in vivo of these findings will be investigated in a clinical trial. © 2010 American Association of Blood Banks.

  2. In vitro viability effects on apheresis and buffy-coat derived platelets administered through infusion pumps

    Directory of Open Access Journals (Sweden)

    Sandgren P

    2014-12-01

    Full Text Available Per Sandgren,1,2 Veronica Berggren,3 Carl Westling,1,2 Viveka Stiller1 1Department of Clinical Immunology and Transfusion Medicine, Karolinska University Hospital, 2Department of Laboratory Medicine, Karolinska Institutet, 3Department of Neonatology, Karolinska University Hospital, Stockholm, SwedenBackground: Different infusion pump systems as well as gravity infusion have been widely used in neonatal transfusion. However, the limited number of published studies describing the use of infusion pumps on platelets illustrates the necessity for more robust data.Methods: To evaluate the potential in vitro effects on the cellular, metabolic, functional and phenotypic properties of platelets, we set up a four-arm paired study simultaneously comparing the use of different infusion pumps (Alaris® CC/GP with unexposed platelets. The platelet units (n=8 were either produced by the apheresis technique and suspended in 100% plasma or derived from buffy coats to yield platelet units stored in approximately 30% plasma and 70% SSP+. Fresh and 5-day old platelets were tested.Results: Regardless of the production system or storage time used, no significant differences were observed in glucose and lactate concentration, pH, adenosine triphosphate levels, response to extent of shape change, hypotonic shock response reactivity, and CD62P expression. Similarly, no differences were observed in expression of the conformational epitope on glycoprotein IIb/IIIa, determined using procaspase-activating compound 1, or in the expression of CD42b and platelet-endothelial cell adhesion molecule-1 in a comparison between platelets administered through infusion pumps versus unexposed platelets.Conclusion: Using Alaris CC/GP infusion pumps had no influence on the cellular, functional, and phenotypic in vitro properties of platelets. This fact seems not to be affected by different production systems or storage time.Keywords: platelets, neonatal platelet transfusion

  3. High DNA stability in white blood cells and buffy coat lysates stored at ambient temperature under anoxic and anhydrous atmosphere.

    Directory of Open Access Journals (Sweden)

    Anne-Lise Fabre

    Full Text Available Conventional storage of blood-derived fractions relies on cold. However, lately, ambient temperature preservation has been evaluated by several independent institutions that see economic and logistic advantages in getting rid of the cold chain. Here we validated a novel procedure for ambient temperature preservation of DNA in white blood cell and buffy coat lysates based on the confinement of the desiccated biospecimens under anoxic and anhydrous atmosphere in original hermetic minicapsules. For this validation we stored encapsulated samples either at ambient temperature or at several elevated temperatures to accelerate aging. We found that DNA extracted from stored samples was of good quality with a yield of extraction as expected. Degradation rates were estimated from the average fragment size of denatured DNA run on agarose gels and from qPCR reactions. At ambient temperature, these rates were too low to be measured but the degradation rate dependence on temperature followed Arrhenius' law, making it possible to extrapolate degradation rates at 25°C. According to these values, the DNA stored in the encapsulated blood products would remain larger than 20 kb after one century at ambient temperature. At last, qPCR experiments demonstrated the compatibility of extracted DNA with routine DNA downstream analyses. Altogether, these results showed that this novel storage method provides an adequate environment for ambient temperature long term storage of high molecular weight DNA in dehydrated lysates of white blood cells and buffy coats.

  4. Characterization of buffy coat-derived granulocytes for clinical use: a comparison with granulocyte colony-stimulating factor/dexamethasone-pretreated donor-derived products

    NARCIS (Netherlands)

    van de Geer, A.; Gazendam, R. P.; Tool, A. T. J.; van Hamme, J. L.; de Korte, D.; van den Berg, T. K.; Zeerleder, S. S.; Kuijpers, T. W.

    2017-01-01

    Buffy coat-derived granulocytes have been described as an alternative to the apheresis product from donors pretreated with dexamethasone and granulocyte colony-stimulating factor (G-CSF). The latter is - dependent on the local and national settings - obtained following a demanding and time-consuming

  5. Effects of storage time and leucocyte burden of packed and buffy-coat depleted red blood cell units on red cell storage lesion

    Science.gov (United States)

    Kamel, Noha; Goubran, Fekry; Ramsis, Neven; Ahmed, Amal Sayed

    2010-01-01

    Background The red cell storage lesion (RCSL) comprises the biochemical and biomechanical changes that take place during red blood cell (RBC) storage, reducing the survival and function of these cells. Contaminating white blood cells have been major contributors to the RCSL. Markers of RCSL, such as CD47 and phosphatidylserine (PS), on RBC are attracting more attention. The aim of this study was to elucidate the effects of storage time and buffy-coat removal on CD47 and PS expression on RBC. Potassium and free haemoglobin levels in the supernatant plasma were also assessed. Materials and methods Forty-three red cell concentrates were divided into two groups [Group 1: packed red cells (n=22); Group 2: red cell units from which the buffy-coat had been removed (n=21)] and samples were collected on days 1, 14 and 28. Flow cytometry was used to monitor changes of CD47 and PS expression on RBC over times. Supernatant potassium was measured and percent of haemolysis calculated. Results A significant, progressive decrease in RBC CD47 expression during storage was observed in both groups. The decrease in RBC CD47 expression was significantly less in the buffy-coat-removed group of units than in the other group. The percentage of annexin V-positive cells increased significantly in both groups. Buffy-coat depleted components showed less expression of PS only in the early samples. There were significant, progressive increases in percentage of haemolysis and supernatant potassium during storage in both groups. Conclusion RBC stored for more than 14 days exhibited reduced CD47 and increased PS. Buffy coat removal reduced the loss of CD47, but had no impact on plasma haemoglobin, potassium or RBC PS exposure. PMID:20967167

  6. A COMPARISON OF RAPID DIAGNOSTIC TESTING (BY PLASMODIUM LACTATE DEHYDROGENASE), AND QUANTITATIVE BUFFY COAT TECHNIQUE IN MALARIA DIAGNOSIS IN CHILDREN.

    Science.gov (United States)

    Ifeorah, Ifeanyi Kanayo; Brown, Biobele J; Sodeinde, Olugbemiro O

    2017-01-01

    The World Health Organization (WHO) considers early and rapid diagnosis as one of the strategies to control malaria. This study compared the performance of Quantitative Buffy Coat (QBC) test and the Plasmodium lactate dehydrogenase (pLDH) rapid diagnostic test (RDT) with microscopy as the gold standard. The study involved children ages 0-5 years who presented with a history of fever at the University College Hospital, Ibadan, Nigeria. Blood was collected from each patient and used for RDT, QBC and Giemsa-stained blood films for malaria parasites (MP). Results of QBC and RDT were compared with microscopy results for the diagnosis of malaria. A total of 370 cases (194 boys and 176 girls) were studied giving a male: female ratio of 1.1:1. Of the 370 cases tested using Giemsa-stained thick blood films for MP, 78 (21 %) were positive. For the QBC test, 78 (21%) of the cases were positive with sensitivity, specificity, positive and negative predictive values of 70.5 %, 92.1%, 70.5 % and 92.1 % respectively. Seventy-six (20%) of the cases were positive by RDT with sensitivity, specificity, positive and negative predictive values of 84.2 %, 95.2 %, 82.1 %, and 95.9 % respectively. There was no significant difference in the sensitivity of QBC compared with the RDT. Both the QBC and the pfLDH (RDT) performed reasonably well in this study Malaria rapid diagnostic tests are recommended in malaria endemic clinical settings to avoid unnecessary antimalarial treatment. List of Abbreviations: AO: Acridine orange, AIDS: Acquired immunodeficiency syndrome, ACT: Artemisinin-based combination therapy, CM:Cerebral malaria, BCP:Benzothiocarboxypurine, DDT:Dichloro-diphenyl-trichloroethane, DNA:DeoxyriboNucleic Acid, ELAM-1: Endothelial leukocyte adhesion molecule, G6PD: Glucose-6-Phosphate Dehydrogenase, HIV: Human immuno deficiency virus, HRP 2: Histidine Rich Protein 2, ICAM -1: Inter cellular adhesion molecule1, ICER: Incremental cost effectiveness ratio, IL-1: Interleukin -1, IFN

  7. Whole blood treated with riboflavin and ultraviolet light: quality assessment of all blood components produced by the buffy coat method.

    Science.gov (United States)

    Schubert, Peter; Culibrk, Brankica; Karwal, Simrath; Serrano, Katherine; Levin, Elena; Bu, Daniel; Bhakta, Varsha; Sheffield, William P; Goodrich, Raymond P; Devine, Dana V

    2015-04-01

    Pathogen inactivation (PI) technologies are currently licensed for use with platelet (PLT) and plasma components. Treatment of whole blood (WB) would be of benefit to the blood banking community by saving time and costs compared to individual component treatment. However, no paired, pool-and-split study directly assessing the impact of WB PI on the subsequently produced components has yet been reported. In a "pool-and-split" study, WB either was treated with riboflavin and ultraviolet (UV) light or was kept untreated as control. The buffy coat (BC) method produced plasma, PLT, and red blood cell (RBC) components. PLT units arising from the untreated WB study arm were treated with riboflavin and UV light on day of production and compared to PLT concentrates (PCs) produced from the treated WB units. A panel of common in vitro variables for the three types of components was used to monitor quality throughout their respective storage periods. PCs derived from the WB PI treatment were of significantly better quality than treated PLT components for most variables. RBCs produced from the WB treatment deteriorated earlier during storage than untreated units. Plasma components showed a 3% to 44% loss in activity for several clotting factors. Treatment of WB with riboflavin and UV before production of components by the BC method shows a negative impact on all three blood components. PLT units produced from PI-treated WB exhibited less damage compared to PLT component treatment. © 2014 AABB.

  8. Storage of buffy-coat-derived platelets in additive solution: in vitro effects on platelets of the air bubbles and foam included in the final unit.

    Science.gov (United States)

    Sandgren, Per; Saeed, Kharija

    2011-04-01

    The air bubbles and foam that develop during the preparation of platelet units have traditionally been considered to interact with the platelets, causing activation and release reactions. However, there actually seems to be no data available concerning the platelet damage that may occur as a result of air bubbles and foam present in the final unit. In this in vitro study we, therefore, investigated the effects of not removing air bubbles/foam from final platelet units, by measuring in vitro parameters during a 7-day storage period. Platelet samples (n=8) from eight pools of 12 buffy-coats were aliquoted and prepared with the OrbiSac system for storage with (test) or without (reference) air bubbles/foam included in the final units. The metabolic, cellular and activation parameters of all units, comprising approximately 30% plasma and 70% SSP+ platelet additive solution, were analysed during the 7-day storage period. Differences in platelet counts and contents between the test and reference units were detected throughout storage (pstorage in the test units and was significantly higher than in the reference units (pstorage between the units (p=NS). Aggregates were visible (day 7) and occurred in three of the test units. pH was maintained at >6.8 (day 7) and swirling remained at the highest level (score =2) for all units throughout storage. This study shows that storage with air bubbles/foam causes considerable enhancement of disintegration of platelets. In addition, various in vitro parameters of the platelets remaining seem to be negatively affected. The results of this study suggest that platelets should be stored without air bubbles/foam, given that these cause increased disintegration of platelets.

  9. Characterization of blood components separated from donated whole blood after an overnight holding at room temperature with the buffy coat method.

    Science.gov (United States)

    Lu, Fa Qiang; Kang, Wei; Peng, Yu; Wang, Wei Ming

    2011-10-01

    With buffy coat (BC) processing of whole blood (WB) donations, increase in WB storage time to facilitate overnight holding before the separation of blood components would be a logistically attractive development. This study undertakes a comparative in vitro characterization of blood components prepared from WB samples that were either processed within 8 hours or stored overnight at room temperature before processing by the BC method. The WB units (400 mL) collected were either processed within 8 hours (fresh blood) or stored overnight (overnight blood) at room temperature. WB units were separated into individual-component red blood cells (RBCs), BC, and plasma. The in vitro quality of these blood components (RBCs, pooled platelet concentrates [PCs], and plasma) was analyzed during storage. Levels of 2,3-diphosphoglycerate (2,3-DPG) were found to be significantly lower immediately after processing, compared with the fresh WB samples, in RBCs that had been separated from an overnight-hold sample. However, this difference was not apparent after 14 days of storage. In pooled PCs, measurements for glucose, lactate, PO(2), PCO(2), extent of shape change, and hypotonic shock response were similar. The platelet yield in PCs prepared from an overnight-hold WB sample was significantly higher, while CD62P expression and annexin V binding were lower (p component that was most sensitive to the prolongation of production time and it only had 80% of the activity of the 8-hour FP. These data suggest that blood components (RBCs, pooled PCs, and FP) separated from WB that has been stored overnight at room temperature by the BC method are of acceptable quality. © 2011 American Association of Blood Banks.

  10. Incidence of Dirofiaria immitis in dogs presented at University of Nigeria, Nsukka Veterinary Teaching Hospital using wet smear and buffy coat techniques

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    Chukwuebuka Iniobong Ikenna Ugochukwu

    2016-08-01

    Full Text Available Objective: To determine the incidence of Dirofilaria immitis (D. immitis in dogs using the wet mount and buffy coat techniques for rapid detection of microfilaria in blood samples collected from dogs, to compare the two techniques for quick detection, to find if there is age susceptibility in the incidence of dirofilariasis in dogs presented at the Veterinary Teaching Hospital, University of Nigeria, Nsukka and to find out if there are breed and sex variations in the incidence of dirofilariasis in dogs presented at Veterinary Teaching Hospital, University of Nigeria, Nsukka. Methods: Blood samples were collected from the cephalic vein of 119 dogs. The blood samples were aseptically collected via cephalic venepuncture of each dog, collected into a tube containing ethylene diamine tetraacetic acid as anticoagulant, stored in an ice pack box at 5 °C and processed and examined for microfilaria using wet mount and buffy coat techniques. Results: A total of 4 dogs were positive for D. immitis microfilaria giving a prevalence of 3.36%, more male (4.83% than female (1.75% dogs were affected in this study. Although there was no significant difference between both groups, the prevalence was the highest in cross breeds (6.66%, moderate in local breeds (3.63% and absent in exotic breeds (0.00%. Although there was no significant (P < 0.05 difference amongst the 3 groups, only adult dogs were found positive for D. immitis microfilaria. Conclusions: Based on the results of this present study, both the wet mount and buffy coat techniques can be used at the discretion of the clinician and in the absence of modified Knott’s filter test, ELISA test and other diagnostic imaging techniques, in the rapid detection of microfilaria in blood samples from suspected cases of dirofilariasis.

  11. Overcoming the bottleneck of platelet lysate supply in large-scale clinical expansion of adipose-derived stem cells: A comparison of fresh versus three types of platelet lysates from outdated buffy coat-derived platelet concentrates.

    Science.gov (United States)

    Glovinski, Peter V; Herly, Mikkel; Mathiasen, Anders B; Svalgaard, Jesper D; Borup, Rehannah; Talman, Maj-Lis M; Elberg, Jens J; Kølle, Stig-Frederik T; Drzewiecki, Krzysztof T; Fischer-Nielsen, Anne

    2017-02-01

    Platelet lysates (PL) represent a promising replacement for xenogenic growth supplement for adipose-derived stem cell (ASC) expansions. However, fresh platelets from human blood donors are not clinically feasible for large-scale cell expansion based on their limited supply. Therefore, we tested PLs prepared via three methods from outdated buffy coat-derived platelet concentrates (PCs) to establish an efficient and feasible expansion of ASCs for clinical use. PLs were prepared by the freeze-thaw method from freshly drawn platelets or from outdated buffy coat-derived PCs stored in the platelet additive solution, InterSol. Three types of PLs were prepared from outdated PCs with platelets suspended in either (1) InterSol (not manipulated), (2) InterSol + supplemented with plasma or (3) plasma alone (InterSol removed). Using these PLs, we compared ASC population doubling time, cell yield, differentiation potential and cell surface markers. Gene expression profiles were analyzed using microarray assays, and growth factor concentrations in the cell culture medium were measured using enzyme-linked immunosorbent assay (ELISA). Of the three PL compositions produced from outdated PCs, removal of Intersol and resuspension in plasma prior to the first freezing process was overall the best. This specific outdated PL induced ASC growth kinetics, surface markers, plastic adherence and differentiation potentials comparable with PL from fresh platelets. ASCs expanded in PL from fresh versus outdated PCs exhibited different expressions of 17 overlapping genes, of which 10 were involved in cellular proliferation, although not significantly reflected by cell growth. Only minor differences in growth factor turnover were observed. PLs from outdated platelets may be an efficient and reliable source of human growth supplement allowing for large-scale ASC expansion for clinical use. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights

  12. Cytokines in platelet concentrates: a comparison of apheresis platelet (haemonetics) and filtered and unfiltered pooled buffy-coat derived platelet concentrates.

    Science.gov (United States)

    Seghatchian, M J; Wadhwa, M; Thorpe, R

    1997-03-01

    Variable degrees of platelet activation, shape changes, microvesiculation and fragmentation may occur during collection, processing and storage of platelet concentrates (PCs), contributing to different rate of platelet storage lesion. Leukocytes contribute to both the frequency of transfusion reactions and the acceleration of the rate of platelet storage lesion hence leukocyte removal of platelet concentrates has been introduced to overcome these problems. However transfusion reaction can still occur with the use of leuko-reduced products and it is not fully elucidated that the rate of storage lesion is equivalent for filtered and unfiltered counter parts. This issue has been addressed in this manuscript comparing the generation of cytokines during storage in PCs derived from pooled buffy coat with the standard apheresis products, with a similar level of leukocyte contamination. The EDTA-induced shape change in platelet was used as an index of platelet functional integrity. In addition IL-8 and TGF beta were used as indicators of filtration process-inducing stimulation of cytokines. Our results clearly indicate that a rapid disc/spheric conversion occurs during storage of buffy-coat derived PC, and while prestorage filtration reduces both IL-8 content immediately after filtration and at the end of platelet shelf life but such a process may lead to slight enhancement of the rate of TGF beta generation indicating that any additional process may have some bearing in stimulation of TGF beta release.

  13. Effect of adhesive properties of buffy coat on the quality of blood components produced with Top & Top and Top & Bottom bags.

    Science.gov (United States)

    Cerelli, Eugenio; Nocera, Martina; Di Bartolomeo, Erminia; Panzani, Paola; Baricchi, Roberto

    2015-04-01

    The Transfusion Medicine Unit of Reggio Emilia currently collects whole blood using conventional quadruple Fresenius Top & Top bags. In this study, new Fresenius Top & Bottom bags were assessed and compared to the routine method with regards to product quality and operational requirements. Twenty-one whole blood units were collected with both the new and the traditional bags, and then separated. Quality control data were evaluated and compared in order to estimate yield and quality of final blood components obtained with the two systems. We collected other bags, not included in the ordinary quality control programme, for comparison of platelet concentrates produced by pools of buffy coat. Compared to the traditional system, the whole blood units processed with Top & Bottom bags yielded larger plasma volumes (+5.7%) and a similar amount of concentrated red blood cells, but with a much lower contamination of lymphocytes (-61.5%) and platelets (-86.6%). Consequently, the pooled platelets contained less plasma (-26.3%) and were significantly richer in platelets (+17.9%). This study investigated the effect of centrifugation on the adhesiveness of the buffy coat to the bag used for whole blood collection. We analysed the mechanism by which this undesirable phenomenon affects the quality of packed red blood cells in two types of bags. We also documented the incomparability of measurements on platelet concentrates performed with different principles of cell counting: this vexing problem has important implications for biomedical research and for the establishment of universal product standards. Our results support the conclusion that the Top & Bottom bags produce components of higher quality than our usual system, while having equal operational efficiency. Use of the new bags could result in an important quality improvement in blood components manufacturing.

  14. Process Improvement by Eliminating Mixing of Whole Blood Units after an Overnight Hold Prior to Component Production Using the Buffy Coat Method

    Science.gov (United States)

    Mastronardi, Cherie; Levin, Elena; Bhakta, Varsha; Yi, Qi-Long; Stewart, Tamiko; Jenkins, Craig; Lefresne, Wanda; Sheffield, William; Acker, Jason P.

    2013-01-01

    The elimination of a thorough manual mixing of whole blood (WB) which takes place following the overnight hold, but before the first centrifugation step, during buffy coat component production at Canadian Blood Services (CBS) was investigated. WB was pooled after donation and split. Pairs of platelet, red blood cell (RBC), and plasma components were produced, with half using the standard method and half using a method in which the mixing step was eliminated. Quality assessments included yield, pH, CD62P expression and morphology for platelets, hemoglobin, hematocrit, hemolysis, and supernatant K+ for RBCs, and volume and factor VIII activity levels for plasma. All components, produced using either method, met CBS quality control criteria. There were no significant differences in platelet yield between components produced with and without mixing. A significant difference was seen for RBC hemolysis at expiry (P = 0.03), but for both groups, levels met quality control requirements. Noninferiority of components produced without mixing was confirmed for all parameters. Manual mixing is laborious and has a risk of repetitive strain for production staff and its significance is unclear. Elimination of this step will improve process efficiencies without compromising quality. PMID:24066260

  15. Process Improvement by Eliminating Mixing of Whole Blood Units after an Overnight Hold Prior to Component Production Using the Buffy Coat Method

    Directory of Open Access Journals (Sweden)

    Cherie Mastronardi

    2013-01-01

    Full Text Available The elimination of a thorough manual mixing of whole blood (WB which takes place following the overnight hold, but before the first centrifugation step, during buffy coat component production at Canadian Blood Services (CBS was investigated. WB was pooled after donation and split. Pairs of platelet, red blood cell (RBC, and plasma components were produced, with half using the standard method and half using a method in which the mixing step was eliminated. Quality assessments included yield, pH, CD62P expression and morphology for platelets, hemoglobin, hematocrit, hemolysis, and supernatant K+ for RBCs, and volume and factor VIII activity levels for plasma. All components, produced using either method, met CBS quality control criteria. There were no significant differences in platelet yield between components produced with and without mixing. A significant difference was seen for RBC hemolysis at expiry (P=0.03, but for both groups, levels met quality control requirements. Noninferiority of components produced without mixing was confirmed for all parameters. Manual mixing is laborious and has a risk of repetitive strain for production staff and its significance is unclear. Elimination of this step will improve process efficiencies without compromising quality.

  16. Diagnostic accuracy of loop-mediated isothermal amplification (LAMP for detection of Leishmania DNA in buffy coat from visceral leishmaniasis patients

    Directory of Open Access Journals (Sweden)

    Khan Md Gulam Musawwir

    2012-12-01

    Full Text Available Abstract Background Visceral leishmaniasis (VL remains as one of the most neglected tropical diseases with over 60% of the world’s total VL cases occurring in the Indian subcontinent. Due to the invasive risky procedure and technical expertise required in the classical parasitological diagnosis, the goal of the VL experts has been to develop noninvasive procedure(s applicable in the field settings. Several serological and molecular biological approaches have been developed over the last decades, but only a few are applicable in field settings that can be performed with relative ease. Recently, loop-mediated isothermal amplification (LAMP has emerged as a novel nucleic acid amplification method for diagnosis of VL. In this study, we have evaluated the LAMP assay using buffy coat DNA samples from VL patients in Bangladesh and compared its performance with leishmania nested PCR (Ln-PCR, an established molecular method with very high diagnostic indices. Methods Seventy five (75 parasitologically confirmed VL patients by spleen smear microcopy and 101 controls (endemic healthy controls −25, non-endemic healthy control-26, Tuberculosis-25 and other diseases-25 were enrolled in this study. LAMP assay was carried out using a set of four primers targeting L. donovani kinetoplast minicircle DNA under isothermal (62 °C conditions in a heat block. For Ln-PCR, we used primers targeting the parasite’s small-subunit rRNA region. Results LAMP assay was found to be positive in 68 of 75 confirmed VL cases, and revealed its diagnostic sensitivity of 90.7% (95.84-81.14, 95% CI, whereas all controls were negative by LAMP assay, indicating a specificity of 100% (100–95.43, 95% CI. The Ln-PCR yielded a sensitivity of 96% (98.96-87.97, 95% CI and a specificity of 100% (100–95.43, 95% CI. Conclusion High diagnostic sensitivity and excellent specificity were observed in this first report of LAMP diagnostic evaluation from Bangladesh. Considering its many fold

  17. The Current Techniques for Preparing Bioglass Coatings

    Science.gov (United States)

    Zhao, Yafan; Chen, Chuanzhong; Wang, Diangang

    Bioglasses are promising alternatives as biomedical materials to repair or replace damaged parts of bones because of its good bioactivity and biocompatibility. It is possible to combine the bone-bonding ability of the bioglass surface with the high mechanical properties of the metallic substrate though the coating of metallic implants with bioglass. The principles and characteristics of some coating techniques, including sintering, plasma spray, sol-gel, electrophoresis deposition, ion beam assisted deposition and pulsed laser deposition, are introduced. Their current applications in preparing bioglass coatings are reviewed in detail. The future application trends are also reviewed.

  18. Application and Preparation of Enteric Coating Materials

    Science.gov (United States)

    Zhou, M. M.; Wang, L.; Zhang, X. L.; Zhou, H. J.; Chen, X. Q.; Li, Y. T.; Yang, S. L.

    2017-02-01

    In this paper, polymethacrylate enteric coated materials based on the equal mass of methyl acrylic acid and ethyl acrylate as the main raw materials were synthesized through emulsion polymerization. Omeprazole Enteric-coated Capsules were prepared by the fluidized bed coating technology using above materials as enteric layer and in vitro enteric test was considered according to standard. The results showed that the material had good coverage in the surface of omeprazole isolated pellets, excellent acid resistance in artificial gastric acid environment, and reached the disintegration effect in the buffer solution of 20min. Moreover the drug release reached 88.2% and had excellent long-term storage.

  19. Preparation of ferrite-coated MFM cantilevers

    Energy Technology Data Exchange (ETDEWEB)

    Koblischka, M.R. [Institute of Experimental Physics, University of Saarbruecken, P. O. Box 151150, D-66041 Saarbruecken (Germany)]. E-mail: m.koblischka@mx.uni-saarland.de; Kirsch, M. [Institute of Experimental Physics, University of Saarbruecken, P. O. Box 151150, D-66041 Saarbruecken (Germany); Wei, J. [Institute of Experimental Physics, University of Saarbruecken, P. O. Box 151150, D-66041 Saarbruecken (Germany); Sulzbach, T. [Nanoworld Services GmbH, Schottkystrasse 10, D-91058 Erlangen (Germany); Hartmann, U. [Institute of Experimental Physics, University of Saarbruecken, P. O. Box 151150, D-66041 Saarbruecken (Germany)

    2007-09-15

    Ferrite-coated magnetic force microscopy (MFM) cantilevers were prepared for the use with a high-frequency MFM (HF-MFM) setup. The ferrite coatings were fabricated by means of radio frequency (RF) magnetron sputtering directly on the Si surface. Two types of ferrites were employed in this study: NiZnFe{sub 2}O{sub 4} spinel and Co{sub 2} Z-type hexaferrite (Ba{sub 3}Co{sub 2}Fe{sub 24}O{sub 41}, BCFO). The typical thickness of the coatings was 50 nm. For comparison, ferrite samples on (1 0 0) and (1 1 1)-oriented Si substrates (analogous to the surfaces of the cantilevers) were prepared. Successful HF-MFM imaging was performed with both types of cantilevers using harddisk writer poles as samples. The HF-MFM images obtained by ferrite-coated cantilevers evidently reveal more details of the magnetic field distribution of the writer poles up to the GHz range than conventional CoCr-coated MFM cantilevers.

  20. Preparing of Ni-Cu-P Coating

    Science.gov (United States)

    Shumei, Kang

    Ni-Cu-P coating by chemical plating has excellent corrosion resistance,wear resistance, thermal stability and electrical conductivity. In this paper, Ni-Cu-P was prepared by chemical deposition methods, the optimum process of chemical plating Ni-Cu-P. By using scanning electron microscopy(SEM), spectrum analyzer, Autolab workstation on the corrosion resistance of the coating. The results showed that: (1)after the specimen surface chemical plating nickelcopper phosphorus treatment, in the same corrosion potential, the corrosion current density was lower than that of Ni-P coating and substrate materials; (2)had a significant effect on corrosion resistance of quantity of citric acid sodium on nickel copper phosphorus alloy plating, coating corrosion resistance with increasing citric acid sodium content first increased and then decreased, and inaddition level of sodium citrate is 40g/L, the corrosion current density reaches a minimum, 14.51×10-6A/cm2; (3)under the same conditions, the Ni-Cu-P alloy coating pH impact is the biggest,the maximum impedance 1268.05Ω; (4)in the 3.5%NaCl solution, with the change of copper content, the main trend of the corrosion current is decreased first and then increased, and the content of copper in Energy spectrum analysis within 5.18Wt% corrosion current density of a minimum of 14.51×10-6A/cm2, the corrosion resistance. With the increase of Cu content in the coatings, the P content first increased and then decreased in the coating, the content of Ni decreased first and then increased; (5)the best technology:NiSO46H2O, CuSO4 25g/L, 5H2O 0.15g/L, C6H5Na3O7•2H2O 40g/L, NaH2PO2H2O 25g/L, CH3COONa 15g/L, KIO3 0.03g/L, C12H25NaO4SO3 0.01g/L, pH4.75 ± 0.01,temperature 80 ± 1 °C, deposition time of 2h.

  1. Preparation of Metal Coatings on Steel Balls Using Mechanical Coating Technique and Its Process Analysis

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    Liang Hao

    2017-04-01

    Full Text Available We successfully applied mechanical coating technique to prepare Ti coatings on the substrates of steel balls and stainless steel balls. The prepared samples were analyzed by X-ray diffraction (XRD and scanning electron microscopy (SEM. The weight increase of the ball substrates and the average thickness of Ti coatings were also monitored. The results show that continuous Ti coatings were prepared at different revolution speeds after different durations. Higher revolution speed can accelerate the formation of continuous Ti coatings. Substrate hardness also markedly affected the formation of Ti coatings. Specifically, the substance with lower surface hardness was more suitable as the substrate on which to prepare Ti coatings. The substrate material plays a key role in the formation of Ti coatings. Specifically, Ti coatings formed more easily on metal/alloy balls than ceramic balls. The above conclusion can also be applied to other metal or alloy coatings on metal/alloy and ceramic substrates.

  2. Preparation of Ti-coated diamond particles by microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Quanchao [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Yunnan Copper Smelting and Processing Complex, Yunnan Copper (Group) CO., LTD., Kunming 650102 (China); International Joint Research Center of Advanced Preparation of Superhard Materials Field, Kunming Academician Workstation of Advanced Preparation of Superhard Materials Field, Kunming 650093 (China); Peng, Jinghui [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); International Joint Research Center of Advanced Preparation of Superhard Materials Field, Kunming Academician Workstation of Advanced Preparation of Superhard Materials Field, Kunming 650093 (China); Xu, Lei, E-mail: xulei_kmust@aliyun.com [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Mechanical Engineering, University of Washington, Seattle, WA 98195 (United States); International Joint Research Center of Advanced Preparation of Superhard Materials Field, Kunming Academician Workstation of Advanced Preparation of Superhard Materials Field, Kunming 650093 (China); Srinivasakannan, C. [Chemical Engineering Department, The Petroleum Institute, P.O. Box 2533, Abu Dhabi (United Arab Emirates); and others

    2016-12-30

    Highlights: • The Ti-Coated diamond particles have been prepared using by microwave heating. • The uniform and dense coating can be produced, and the TiC species was formed. • With increases the temperature results in the thickness of coating increased. • The coating/diamond interfacial bonding strength increased with temperature increasing until 760 °C, then decreased. - Abstract: Depositing strong carbide-forming elements on diamond surface can dramatically improve the interfacial bonding strength between diamond grits and metal matrix. In the present work, investigation on the preparation of Ti-coated diamond particles by microwave heating has been conducted. The morphology, microstructure, and the chemical composition of Ti-coated diamond particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive x-ray spectrometer (EDX). The thickness of Ti coating was measured and the interfacial binding strength between Ti coating and diamond was analyzed. The results show that the surface of the diamond particles could be successfully coated with Ti, forming a uniform and continuous Ti-coated layer. The TiC was found to form between the surface of diamond particles and Ti-coated layer. The amount of TiC as well as the thickness of coating increased with increasing coating temperature, furthermore, the grain size of the coating also grew gradually. The interfacial bonding strength between coating and diamond was found to be best at the temperature of 760 °C.

  3. Dense protective coatings, methods for their preparation and coated articles

    Science.gov (United States)

    Tulyani, Sonia; Bhatia, Tania; Smeggil, John G.

    2015-12-29

    A method for depositing a protective coating on a complex shaped substrate includes the steps of: (1) dipping a complex shaped substrate into a slurry to form a base coat thereon, the slurry comprising an aqueous solution, at least one refractory metal oxide, and at least one transient fluid additive present in an amount of about 0.1 percent to 10 percent by weight of the slurry; (2) curing the dipped substrate; (3) dipping the substrate into a precursor solution to form a top barrier coat thereon; and (4) heat treating the dipped, cured substrate to form a protective coating.

  4. Study on Preparation Technologies of Thermal Barrier Coatings

    Science.gov (United States)

    Wang, Tao; Wang, Ning; Li, Yang; Wang, Hao; Tang, Jie; Wang, Yunshan

    Thermal barrier coatings (TBCs) is one of the main key technology for the high-pressure turbine blades which are the main components of the high-performance aerospace engines. It offers protection for underline metallic components from corrosion, oxidation and localized melting by insulating the metal from hot gases in the engine core. The properties and lifetime of TBCs are greatly influenced by the preparation technology, which includes plasma spraying (PS), physical vapor deposition (PVD) and laser re-melting (LM). In this paper, three technologies used to prepare the TBCs are reviewed. Resulting features of coating fabricated by each technology are also discussed such as: the porosity, the thermally grown oxide (TGO), the erosion resistance, the thermal shock and so on. Especially, it is pointed out that the performances of gradient coating and nano-coating are better than the traditional coatings. In addition, it is widely accepted that laser can be applied to re-melt the PS coating and even directly clad the gradient coating. In the future, the traditional preparation technology should be improved continually in order to enhance the coating lifetime, enhance the properties of coating and lower the cost of process. Moreover, the researches on gradient-nano-structured coatings preparation are absent and should be done with emphasis since the nano-structure and gradient structure can both benefit the lifetime and properties of coatings.

  5. Coated woven materials and method of preparation

    Science.gov (United States)

    McCreary, W.J.; Carroll, D.W.

    Coating of woven materials so that not only the outer surfaces are coated has been a problem. Now, a solution to that problem is by coating with materials, with metals or with pyrolytic carbon. Materials are deposited in Chemical Vapor Deposition (CND) reactions using a fluidized bed so that the porosity of the woven materials is retained and the tiny filaments which make up the strands which are woven (including inner as well as outer filaments) are substantially uniformly coated.

  6. NIF Anti-Reflective Coating Solutions: Preparation, Procedures and Specifications

    Energy Technology Data Exchange (ETDEWEB)

    Suratwala, T; Carman, L; Thomas, I

    2003-07-01

    The following document contains a detailed description of the preparation procedures for the antireflective coating solutions used for NIF optics. This memo includes preparation procedures for the coating solutions (sections 2.0-4.0), specifications and vendor information of the raw materials used and on all equipment used (section 5.0), and QA specifications (section 6.0) and procedures (section 7.0) to determine quality and repeatability of all the coating solutions. There are different five coating solutions that will be used to coat NIF optics. These solutions are listed below: (1) Colloidal silica (3%) in ethanol (2) Colloidal silica (2%) in sec-butanol (3) Colloidal silica (9%) in sec-butanol (deammoniated) (4) HMDS treated silica (10%) in decane (5) GR650 (3.3%) in ethanol/sec-butanol The names listed above are to be considered the official name for the solution. They will be referred to by these names in the remainder of this document. Table 1 gives a summary of all the optics to be coated including: (1) the surface to be coated; (2) the type of solution to be used; (3) the coating method (meniscus, dip, or spin coating) to be used; (4) the type of coating (broadband, 1?, 2?, 3?) to be made; (5) number of optics to be coated; and (6) the type of post processing required (if any). Table 2 gives a summary of the batch compositions and measured properties of all five of these solutions.

  7. Preparation of a MFI zeolite coating on activated carbon

    NARCIS (Netherlands)

    van der Vaart, R; van der Vaart, R.; Bosch, H.; Keizer, Klaas; Reith, T.

    1997-01-01

    A new and simple method for the preparation of MFI zeolite coated activated carbon is presented. Suitable nucleation sites for the growth of zeolites were introduced to the carbon by adding hydrophilic montmorillonite clay to the carbon substrate. A gas tight MFI zeolite coating was obtained on this

  8. Preparation of a MFI zeolite coating on activated carbon

    OpenAIRE

    van der Vaart, R.; Bosch, H.; Keizer, Klaas; Reith, T.

    1997-01-01

    A new and simple method for the preparation of MFI zeolite coated activated carbon is presented. Suitable nucleation sites for the growth of zeolites were introduced to the carbon by adding hydrophilic montmorillonite clay to the carbon substrate. A gas tight MFI zeolite coating was obtained on this modified substrate by hydrothermal growth.

  9. [Preparation of tablets containing enteric-coated diclofenac sodium pellets].

    Science.gov (United States)

    Qi, Xiao-Le; Zhu, Jia-Bi; Chen, Sheng-Jun

    2008-01-01

    Fluidized-bed manufactured enteric-coated diclofenac sodium pellets were compressed into tablets. The blend of two aqueous acrylic resins dispersion in different ratios, Eudragit NE30D and Eudragit L30D-55, were used to prepare enteric-coated diclofenac sodium pellets of different particle sizes and coating level. The cushioning pellets with different properties and these enteric-coated pellets were compressed into tablets in different proportions. The drug release of the tablets containing these pellets would be lower than 10% in 2 h in simulated gastric fluid, but reach (83 +/- 2.42)% in 1 h in simulated enteric fluid. The mixture of Eudragit NE30D and Eudragit L30D-55 could be used to prepare enteric pellets which are suitable for compression. The cushioning pellets which were composed of stearic acid/microcrystalline cellulose (4:1, w/w) could avoid rupture of the coating of pellets during the compression.

  10. Preparation and Post-Functionalization of Hyperbranched Polyurea Coatings

    NARCIS (Netherlands)

    Xiang, Fei; Asri, Lia; Ivashenko, Oleksii; Rudolf, Petra; Loontjens, Ton

    2015-01-01

    Postfunctionalizable hyperbranched polyurea coatings were prepared by the bulk polycondensation of AB(2) monomers on preactivated silicon substrates. As previously shown, AB(2) monomers were prepared, comprising a secondary amino group (A) and two blocked isocyanates (B) connected by hexyl spacers,

  11. Universal Nature-Inspired Coatings for Preparing Noncharging Surfaces.

    Science.gov (United States)

    Fang, Yan; Gonuguntla, Spandhana; Soh, Siowling

    2017-09-20

    Static charge generated by contact electrification on surfaces can lead to many undesirable consequences such as a reduction in the efficiency of manufacturing processes, damage to equipment, and explosions. However, it is extremely challenging to avoid contact electrification because it is ubiquitous: almost all types of materials charge on contact. Here, we coated materials with naturally occurring polydopamine (PDA) and tannic acid (TA) for preparing noncharging surfaces. Importantly, these coatings are very versatile and can be coated on a wide range of materials, including metals, inorganic materials, semiconductors, and polymers. Once coated, the amount of charge generated was found to reduce dramatically at different humidities. The reduction in charge may be due to the radical-scavenging property of PDA and TA. This simple general approach is ideal for coating the vast variety of materials that need to resist charging by contact electrification.

  12. Preparation of amine coated silver nanoparticles using ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. This article presents a simple method towards the preparation of functionalized silver nano- particles in a continuous medium. Silver nanoparticles were obtained through AgNO3 chemical reduction in ethanol and triethylenetetramine was used to stabilize and functionalize the metal. The product was characterized ...

  13. Preparation and characterization of biocompatible Nb-C coatings

    Energy Technology Data Exchange (ETDEWEB)

    Braic, M.; Braic, V.; Balaceanu, M. [National Institute for Optoelectronics, 409 Atomistilor, Magurele (Romania); Vladescu, A., E-mail: alinava@inoe.r [National Institute for Optoelectronics, 409 Atomistilor, Magurele (Romania); Zoita, C.N. [National Institute for Optoelectronics, 409 Atomistilor, Magurele (Romania); Titorencu, I. [Petru Poni Institute of Macromolecular Chemistry, 41A, Aleea G.G.Voda, Iasi (Romania); Institute of Cellular Biology and Pathology ' Nicolae Simionescu' , 8 B.P. Hasdeu, Bucharest (Romania); Jinga, V. [Petru Poni Institute of Macromolecular Chemistry, 41A, Aleea G.G.Voda, Iasi (Romania); Miculescu, F. [University Politehnica of Bucharest, 313 Sp. Independentei, Bucharest (Romania)

    2011-04-01

    Nb-C composite films, obtained by DC magnetron sputtering method, were investigated as possible candidates for the protective layers used in medical implants. Coatings of different carbon/niobium ratios were prepared and analyzed for elemental and phase composition, crystallographic structure, texture, corrosion behavior, and cell viability. The coating with the highest C/Nb ratio ({approx} 1.9) was found to have a nanocomposite structure, in which NbC nanocrystalline phase coexists with an amorphous a-C one. The coated samples exhibited an improved corrosion resistance as compared with the Ti alloy. Cell viability measurements proved that human osteosarcoma cells are adherent to the coating surfaces, the highest viability being found for the film with the highest carbon content.

  14. Conversion coatings prepared or treated with calcium hydroxide solutions

    Science.gov (United States)

    Minevski, Zoran (Inventor); Clarke, Eric (Inventor); Maxey, Jason (Inventor); Nelson, Carl (Inventor); Eylem, Cahit (Inventor)

    2002-01-01

    A conversion coating process that forms a stable and corrosion-resistant oxide layer on metal or metal oxide substrates or layers. Particularly, the conversion coating process involves contacting the metal or metal oxide substrate or layer with the aqueous calcium hydroxide solutions in order to convert the surface of the substrate to a stable metal oxide layer or coating. According to the present invention, the calcium hydroxide solution is prepared by removing carbon dioxide from water or an aqueous solution before introducing the calcium hydroxide. In this manner, formation of calcium carbonate particles is avoided and the porosity of the conversion coating produced by the calcium hydroxide solution is reduced to below about 1%.

  15. Thick c-BN coatings - Preparation, properties and application tests

    Energy Technology Data Exchange (ETDEWEB)

    Keunecke, M. [Fraunhofer Institute for Surface Engineering and Thin Films (IST), Braunschweig (Germany)]. E-mail: martin.keunecke@ist.fraunhofer.de; Wiemann, E. [Institute for Machine Tools and Factory Management (IWF), Berlin University of Technology (Germany); Weigel, K. [Fraunhofer Institute for Surface Engineering and Thin Films (IST), Braunschweig (Germany); Park, S.T. [Fraunhofer Institute for Surface Engineering and Thin Films (IST), Braunschweig (Germany); Bewilogua, K. [Fraunhofer Institute for Surface Engineering and Thin Films (IST), Braunschweig (Germany)

    2006-11-23

    Due to the outstanding properties of cubic boron nitride (c-BN) - c-BN is the second hardest of all known materials, has a high wear resistance and a high thermal stability - this material is very promising for a broad range of applications, especially for cutting tools, both as bulk and as a coating material. The state-of-the-art is the use of sintered cutting inserts with c-BN grains. Such c-BN grains are synthesized in an expensive high-pressure-high-temperature process. The requirements for cutting tools continuously increase in production engineering and this leads to a strong demand for new super hard tool coatings. Cubic boron nitride coatings could be an attractive solution. Unfortunately, the preparation of thick c-BN coatings, on the {mu}m scale, is difficult, due to some serious drawbacks and has been successful only in the last years for a few research groups worldwide. PVD processes allow the preparation of c-BN films thicker than 2 {mu}m on silicon and 1 {mu}m c-BN top layers on pre-coated cemented carbide cutting inserts. Measurements of mechanical properties like hardness and Young's modulus reveal that the properties of the c-BN coatings, with hardness of about 60 GPa, are nearly identical to those of c-BN bulk material. Results of systematic turning and milling tests of different coatings in combination with a c-BN top-layer on cemented carbide cutting inserts will be presented in detail. The new results confirm the high potential of c-BN coatings on cutting tools.

  16. Buffy the Vampire Slayer: A Superheroine, but not in Serbia

    National Research Council Canada - National Science Library

    Ljiljana Gavrilović

    2016-01-01

    This paper discusses the television series Buffy the Vampire Slayer, more specifically, its enormous popularity in the United States, Western Europe and Australia, and the absence of any reaction to the series in Serbia...

  17. Preparation and Properties of Microarc Oxidation Self-Lubricating Composite Coatings on Aluminum Alloy

    OpenAIRE

    Zhenwei Li; Shichun Di

    2017-01-01

    Microarc oxidation (MAO) coatings were prepared on 2024-T4 aluminum alloy using pulsed bipolar power supply at different cathode current densities. The MAO ceramic coatings contained many crater-like micropores and a small number of microcracks. After the MAO coatings were formed, the coated samples were immersed into a water-based Polytetrafluoroethylene (PTFE) dispersion. The micropores and microcracks on the surface of the MAO coatings were filled with PTFE dispersion for preparing MAO sel...

  18. Buffy the Vampire Slayer: A Superheroine, but not in Serbia

    Directory of Open Access Journals (Sweden)

    Ljiljana Gavrilović

    2016-02-01

    Full Text Available This paper discusses the television series Buffy the Vampire Slayer, more specifically, its enormous popularity in the United States, Western Europe and Australia, and the absence of any reaction to the series in Serbia. By comparing themes regarded as important in western societies to the current situation in Serbia, the analysis shows that Buffy the Vampire Slayer is a series that could not have gained popularity in Serbia because it uses the language of fantasy to speak about reality and pose unpleasant questions, which the Serbian public does not wish to hear.

  19. Bibliographic Good vs. Evil in Buffy the Vampire Slayer.

    Science.gov (United States)

    DeCandido, GraceAnne A.

    1999-01-01

    Describes the pivotal role of the school librarian in the television series, "Buffy the Vampire Slayer." Discusses the image of librarians; the power of knowledge; information-seeking behavior; the methodical nature of research; the importance of printed materials; issues with computers and online technology; and censorship and…

  20. Estudo do método da extração da camada leucoplaquetária na produção de hemocomponentes: avaliação laboratorial A study of the Buffy-coat extraction method for blood component processing: laboratorial analysis

    Directory of Open Access Journals (Sweden)

    Mario I. Serinolli

    2004-01-01

    Full Text Available Dentre os métodos para a obtenção de hemocomponentes destaca-se o método do plasma rico em plaquetas (PRP e o método da extração da camada leucoplaquetária (ECLP. Este estudo tem por objetivo comparar os métodos do PRP e da ECLP na produção de hemocomponentes. Foram processadas 88 bolsas de sangue total (ST pelo método do PRP, 130 bolsas triplas pelo método da ECLP (ECLPT e 215 bolsas coletadas em bolsas quádruplas pelo método da ECLP (ECLPQ com o uso de extrator automático. Encontramos diferença estatisticamente significante na quantidade de Hb total /unidade entre ECLPT e ECLPQ (p=0,005 e entre ECLPT e PRP (p=0,007 no ST. Houve diferença estatisticamente entre ECLPT e ECLPQ (pThe most commonly used methods for blood component processing are the "plasma rich in platelets method" (PRP, and the Buffy-coat extraction method (BC.The purpose of this study was to compare these two methods in the processing of blood components. Eighty-eight whole blood units (WB were processed by the PRP method, 130 blood units were processed by the BC triple blood bag method (BCT and 215 blood units were collected in quadruple blood bags by the BC method (BCQ using an automatic extractor. A statistically significant difference was observed in the number in the total Hb per unit of WB between the BCT and BCQ methods (p=0.005 and between the BCT and PRP methods (p=0.007. There were also statistically significant differences between the BCT and BCQ methods (p<0.001 and between BCQ and PRP methods (p<0.001 in relation to leukocytes/mL. In the RBC concentrates, we found statistically significant differences between the PRP method and both the BCT and BCQ methods in respect to hematocrit levels, Hb recovery, total Hb, leukocytes, leukocyte depletion, platelets and platelet depletion (p<0.001 in all cases. We also found statistically significant differences between the PRP, BCT and BCQ methods for the volume, platelet recovery, and leukocyte depletion (p<0

  1. Preparation of Nickel-Copper Bilayers Coated on Single-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Zhong Zheng

    2015-01-01

    Full Text Available Due to oxidizability of copper coating on carbon nanotubes, the interfacial bond strength between copper coating and its matrix is weak, which leads to the reduction of the macroscopic properties of copper matrix composite. The electroless coating technics was applied to prepare nickel-copper bilayers coated on single-walled carbon nanotubes. The coated single-walled carbon nanotubes were characterized through transmission electron microscope spectroscopy, field-emission electron microscope spectroscopy, X-ray diffractometry, and thermogravimetric analysis. The results demonstrated that the nickel-copper bilayers coated on single-walled carbon nanotubes possessed higher purity of unoxidized copper fine-grains than copper monolayers.

  2. Preparation of a Novel Water-based Acrylic Multi-Thermal Insulation Coating

    OpenAIRE

    Xiufang YE; Dongchu CHEN; Chang, Menglei; Youtian MO; Wang, Qingxiang

    2017-01-01

    To efficiently improve the thermal insulation effect of coatings, a novel water-based acrylic multi-thermal insulation coating (multi-WATIC) combined with thermal obstruction, echo, and radiation was prepared. The category and ratio of thermal insulation functional fillers are crucial. First, water-based acrylic thermal insulation coating (WATIC) with single thermal insulation functional fillers was prepared, and the thermal insulation property tests were done. Thereafter, a novel multi-WATIC...

  3. Preparation and Characterization of Fluorinated Hydrophobic UV-Crosslinkable Thiol-Ene Polyurethane Coatings

    Directory of Open Access Journals (Sweden)

    Wenjing Xia

    2017-08-01

    Full Text Available The polyurethane prepolymer terminated with a double bond was synthesized using isophorone diisocyanate (IPDI, hydroxyl terminated polybutadiene (HTPB, 1,4-butanediol (BDO, and 2-hydroxyethyl acrylate (HEA. Then, a series of innovative UV-curable polyurethane coatings were prepared by blending ene-terminated polyurethane, fluoroacrylate monomer, and multifunctional thiol crosslinker upon UV exposure. The incorporation of fluoroacrylate monomer and multifunctional thiols into polyurethane coatings significantly enhanced the hydrophobic property, mechanical property, pencil hardness, and glossiness of the polyurethane coatings. This method of preparing UV crosslinkable, hydrophobic polyurethane coatings based on thiol-ene chemistry exhibited numerous advantages over other UV photocuring systems.

  4. Calcium phosphorus bio-coating on carbon/carbon composites: Preparation, shear strength and bioactivity

    Science.gov (United States)

    Su, Yangyang; Li, Kezhi; Zhang, Leilei; Liu, Shoujie; Yuan, Ye; He, Song

    2017-10-01

    Microwave hydrothermal (MH) combining supersonic atmospheric plasma sprayed (SAPS) calcium phosphorus (Ca-P) bio-coatings on carbon/carbon (C/C) composite has been widely used due to their osteoconductivity and osteoproductivity. However, the erratic shear strength between coatings prepared only by SAPS (outer coating) and C/C substrates has attached more attention over the implant failure. Adding a coating prepared by MH (inner coating) before SAPS can possess superior shear strength to conventional outer coating. The inner coating with fine Ca-P particles was prepared through a unique MH method under different concentrations (10, 500 and 1000 mmol/L). The influence of concentration on microstructure, phase composition, roughness and shear strength are investigated in this paper. In particularly, the roughness of inner coatings on C/C substrates was found to related to the morphologies and particle size. Results showed that inner coatings have higher roughness which was beneficial for the promotion of shear strength between the obtained Ca-P bio-coating and the C/C substrates. Subsequently, the specimens were immersed in a simulated body fluid (SBF) to investigate the bioactivity.

  5. Preparation and Properties of Microarc Oxidation Self-Lubricating Composite Coatings on Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    Zhenwei Li

    2017-04-01

    Full Text Available Microarc oxidation (MAO coatings were prepared on 2024-T4 aluminum alloy using pulsed bipolar power supply at different cathode current densities. The MAO ceramic coatings contained many crater-like micropores and a small number of microcracks. After the MAO coatings were formed, the coated samples were immersed into a water-based Polytetrafluoroethylene (PTFE dispersion. The micropores and microcracks on the surface of the MAO coatings were filled with PTFE dispersion for preparing MAO self-lubricating composite coatings. The microstructure and properties of MAO coatings and the wear resistance of microarc oxidation self-lubricating composite coatings were analyzed by SEM, laser confocal microscope, X-ray diffractometry (XRD, Vickers hardness test, scratch test and ball-on-disc abrasive tests, respectively. The results revealed that the wear rates of the MAO coatings decreased significantly with an increase in cathode current density. Compared to the MAO coatings, the microarc oxidation self-lubricating composite coatings exhibited a lower friction coefficient and lower wear rates.

  6. INFLUENCE OF WORKPIECE SURFACE PREPARATION ON THERMAL BARRIER COATING DURABILITY

    Directory of Open Access Journals (Sweden)

    M. A. Petrova

    2014-01-01

    Full Text Available Article deals with the impact of workpiece surface quality on adhesive strength and durability of thermal barrier coating. The result revealed that the roughness of metal layer influences on the adhesion of ceramic coating and depends the thickness of ceramic crystals when using method of Electron beam deposition.

  7. Preparation of aluminide coatings on the inner surface of tubes by heat treatment of Al coatings electrodeposited from an ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Dongpeng; Chen, Yimin [School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Ling, Guoping, E-mail: linggp@zju.edu.cn [School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Liu, Kezhao; Chen, Chang’an; Zhang, Guikai [National Key Laboratory of Surface Physics, China Academy of Engineering Physics, Mianyang 621900 (China)

    2015-12-15

    Highlights: • Al coating is prepared on the inner surface of one-meter tube. • Al coating shows good adherence to the substrate. • The thickness of Al coating is uniform along the tube. • Aluminide coating is obtained by heat treating Al coating. • Structure of aluminide coating is regulated by different thickness of Al coating. - Abstract: Aluminide coatings were prepared on the inner surface of 316L stainless steel tubes with size of Ø 12 mm × 1000 mm by heat-treating Al coatings electrodeposited from AlCl{sub 3}-1-ethyl-3-methyl-imidazolium chloride (AlCl{sub 3}–EMIC) ionic liquid at room temperature. Studies on the electrolytic etching pretreatment of stainless tubes before Al coating electrodeposition were carried out. The Al coating showed good adherence to the substrate after electrolytic etching at 10 mA/cm{sup 2} for 10 min. The thickness of Al coatings was uniform along the tube. The structure of prepared aluminide coatings can be regulated by different thickness of Al coating. The outer layer of aluminide coatings was FeAl, Fe{sub 2}Al{sub 5} and FeAl{sub 3} for the samples of 1-μm, 5-μm and 10-μm thick Al coatings, respectively.

  8. Facile Preparation of a Robust and Durable Superhydrophobic Coating Using Biodegradable Lignin-Coated Cellulose Nanocrystal Particles

    Science.gov (United States)

    Huang, Jingda; Lyu, Shaoyi

    2017-01-01

    It is a challenge for a superhydrophobic coating to overcome the poor robustness and the rough surface structure that is usually built using inorganic particles that are difficult to degrade. In this study, a robust superhydrophobic coating is facilely prepared by using commercial biodegradable lignin-coated cellulose nanocrystal (L-CNC) particles after hydrophobic modification to build rough surface structures, and by choosing two different adhesives (double-sided tape and quick-setting epoxy) to support adhesion between the L-CNC particles and the substrates. In addition to excellent self-cleaning and water repellence properties, the resulting coatings show outstanding mechanical strength and durability against sandpaper abrasion, finger-wipe, knife-scratch, water jet, UV radiation, high temperature, and acidic and alkali solutions, possessing a wide application prospect. PMID:28906449

  9. The Preparation of Capsaicin-Chitosan Microspheres (CCMS Enteric Coated Tablets

    Directory of Open Access Journals (Sweden)

    Jian Chen

    2013-12-01

    Full Text Available This study aimed to research the preparation and content determination of capsaicin-chitosan microspheres (CCMS enteric coated tablets. The core tablets were prepared with the method of wet granulation. Nine formulae were designed to determine the optimal formula of the core tablet. Eudragit L100 was used to prepare the CCMS enteric-coated tablets. The effect of enteric coated formulation variables such as content of talc (10%, 25% and 40%, plasticisers (TEC and DBS, dosage of plasticiser (10%, 20% and 30% and coating weight (2%, 3% and 5% were evaluated for drug release characteristics. The in vitro release was studied using 0.1 N HCl and pH 6.8 phosphate buffer. Enteric coated tablets without ruptures or swelling behaviour over 2 h in 0.1 N HCl indicated that these tablets showed acid resistance. The accumulated release rate in phosphate buffer (pH 6.8 revealed that the prepared tablets were able to sustain drug release into the intestine and a first-order release was obtained for capsaicin. This research is the first report of the preparation and content determination of CCMS enteric coated tablets. The sustained release behavior of enteric coated formulations in pH 6.8 phosphate buffer demonstrated that it would be a potential drug delivery platform for sustained delivery of gastric irritant drugs.

  10. Preparation and Application of Conductive Textile Coatings Filled with Honeycomb Structured Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Filip Govaert

    2014-01-01

    Full Text Available Electrical conductive textile coatings with variable amounts of carbon nanotubes (CNTs are presented. Formulations of textile coatings were prepared with up to 15 wt % of CNT, based on the solid weight of the binder. The binders are water based polyacrylate dispersions. The CNTs were mixed into the binder dispersion starting from a commercially available aqueous CNT dispersion that is compatible with the binder dispersion. Coating formulations with variable CNT concentrations were applied on polyester and cotton woven and knitted fabrics by different textile coating techniques: direct coating, transfer coating, and screen printing. The coatings showed increasing electrical conductivity with increasing CNT concentration. The coatings can be regarded to be electrically conductive (sheet resistivity<103 Ohm/sq starting at 3 wt% CNT. The degree of dispersion of the carbon nanotubes particles inside the coating was visualized by scanning electron microscopy. The CNT particles form honeycomb structured networks in the coatings, proving a high degree of dispersion. This honeycomb structure of CNT particles is forming a conductive network in the coating leading to low resistivity values.

  11. Advancement in Preparation of Hydroxyapatite/bioglass Graded Coatings by Electrophoretic Deposition

    Science.gov (United States)

    Yao, Liang; Chen, Chuanzhong; Wang, Diangang; Bao, Quanhe; Ma, Jie

    Electrophoretic deposition is a good method in the preparation of hydroxyapatite/bioglass graded coatings. Its processing parameters are easy to be operated. As it is nonbeeline process, it can be used in the deposition of complex shape and porous surface. This paper reviewed the advancement of the graded coatings in recent years, concluded the principles, characters, steps of electrophoretic deposition of bioceramic coatings and analyzed influencing factors in detail, such as granularity of suspension, aging of suspension, dispersion media, PH of suspension, electricity, voltage, deposition time, pretreatment of substrate and sintering. The foreground of hydroxyapatite/bioglass graded coatings is expected.

  12. Preparation and Microcosmic Structural Analysis of Recording Coating on Inkjet Printing Media

    Directory of Open Access Journals (Sweden)

    Yudong Huang

    2011-08-01

    Full Text Available Preparation of recording coating on inkjet printing (RC-IJP media was proposed. The microstructure and roughness of RC-IJP was analyzed by scanning electron microscopy (SEM and atomic force microscope (AFM. The surface infiltration process of RC-IJP was studied by a liquid infiltration instrument. The distribution of C, O and Si composites on recording coating surface is analyzed by energy dispersive spectrum (EDS. The transmission electron microscopy (TEM analysis showed that the nanoscale silica could be dissolved uniformly in water. Finally, the print color is shown clearly by the preparative recording coating.

  13. ISOL Targets Prepared with a New Paint Infiltration Coating Method

    CERN Document Server

    Kawai, Yoko; Kiggans, J O; Stracener, Dan

    2005-01-01

    A new infiltration paint coating method has been developed for fabricating ISOL targets for radioactive ion beam applications. The technique has been shown to be inexpensive, fast, and almost universal for the uniform deposition of many refractory target materials onto the interior surfaces of complex geometry matrices, such as Reticulated-Vitreous-Carbon-Foam (RVCF). The process yields robust, highly permeable targets with fast diffusion and release properties. We demonstrate the viability of the technique for coating forms of RVCF compressed by factors of 6 and 10 with materials to form targets for use at high energy facilities such as RIA. The use of compressed RVCF, coated with an optimum thickness of target material, reduces target lengths to practical values, while preserving high permeability. We calculate thermal conductivities and diffusion for various targets on 6xRVCF and 10xRVCF.

  14. Preparation of spherical ceria coated silica nanoparticle abrasives for CMP application

    Energy Technology Data Exchange (ETDEWEB)

    Peedikakkandy, Lekha [Department of Metallurgical Engineering and Materials Science, IIT Bombay, Powai, Mumbai 400076 (India); Kalita, Laksheswar [Advanced Technology Group, Applied Materials India Pvt. Ltd., Department of Electrical Engineering, IIT Bombay, Powai, Mumbai 400076 (India); Kavle, Pravin [Department of Metallurgical Engineering and Materials Science, IIT Bombay, Powai, Mumbai 400076 (India); Kadam, Ankur; Gujar, Vikas; Arcot, Mahesh [Advanced Technology Group, Applied Materials India Pvt. Ltd., Department of Electrical Engineering, IIT Bombay, Powai, Mumbai 400076 (India); Bhargava, Parag, E-mail: pbhargava@iitb.ac.in [Department of Metallurgical Engineering and Materials Science, IIT Bombay, Powai, Mumbai 400076 (India)

    2015-12-01

    Highlights: • Nano-layer coating of ceria over silica nanoparticles. • Study effect of reaction pH and temperature on ceria coating over silica nanoparticles. • CMP application of ceria coated silica nanoparticles over SiO{sub 2} and SiN films. - Abstract: This paper describes synthesis of spherical and highly mono-dispersed ceria coated silica nanoparticles of size ∼70–80 nm for application as abrasive particles in Chemical Mechanical Planarization (CMP) process. Core silica nanoparticles were initially synthesized using micro-emulsion method. Ceria coating on these ultrafine and spherical silica nanoparticles was achieved using controlled chemical precipitation method. Study of various parameters influencing the formation of ceria coated silica nanoparticles of size less than 100 nm has been undertaken and reported. Ceria coating over silica nanoparticles was varied by controlling the reaction temperature, pH and precursor concentrations. Characterization studies using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Energy Dispersive X-ray analysis show formation of crystalline CeO{sub 2} coating of ∼10 nm thickness over silica with spherical morphology and particle size <100 nm. Aqueous slurry of ceria coated silica abrasive was prepared and employed for polishing of oxide and nitride films on silicon substrates. Polished films were studied using ellipsometry and an improvement in SiO{sub 2}:SiN selective removal rates up to 12 was observed using 1 wt% ceria coated silica nanoparticles slurry.

  15. Preparation and Mechanism Analysis of an Environment- friendly Maize Seed Coating Agent.

    Science.gov (United States)

    Zeng, Defang; Fan, Zhao; Tian, Xu; Wang, Wenjin; Zhou, Mingchun; Li, Haochuan

    2017-11-23

    Traditional seed coating agents often contain toxic ingredients, which contaminate environment and threaten human health. This paper expounds a method of preparing a novel environment-friendly seed coating agent for maize and researches its mechanism of action. The natural polysaccharide polymer, which is the main active ingredient of this environment-friendly seed coating agent, has the characteristics of innocuity and harmlessness, and it can replace the toxic ingredients used in the traditional seed coating agents. This environment-friendly seed coating agent for maize was mainly made up of the natural polysaccharide polymer and other additives. The field trials results showed that the control efficacy of Helminthosporiun maydis came to 93.72%, the anti-feeding rate of cutworms came to 81.29%, and the maize yield was increased by 17.75%. Besides, the LD50 value (half the lethal dose of rats) of this seed coating agent was 10 times higher than that of the traditional seed coating agents. This seed coating agent could improve the activity of plant protective enzymes (peroxidase, catalase and superoxidase dismutase) and increase the chlorophyll content. This seed coating agent has four characteristics of disease prevention, desinsectization, increasing yield and safety. The mechanism analyses results showed that this seed coating agent could enhance the disease control effectiveness by improving plant protective enzymes activity and increase maize yield by improving chlorophyll content. This article is protected by copyright. All rights reserved.

  16. Co3O4 protective coatings prepared by Pulsed Injection Metal Organic Chemical Vapour Deposition

    DEFF Research Database (Denmark)

    Burriel, M.; Garcia, G.; Santiso, J.

    2005-01-01

    of deposition temperature. Pure Co3O4 spinel structure was found for deposition temperatures ranging from 360 to 540 degreesC. The optimum experimental parameters to prepare dense layers with a high growth rate were determined and used to prepare corrosion protective coatings for Fe-22Cr metallic interconnects...

  17. Solid self-nanoemulsifying cyclosporin A pellets prepared by fluid-bed coating: preparation, characterization and in vitro redispersibility.

    Science.gov (United States)

    Lei, Yang; Lu, Yi; Qi, Jianping; Nie, Sufang; Hu, Fuqiang; Pan, Weisan; Wu, Wei

    2011-01-01

    The objective of this study was to evaluate fluid-bed coating as a new technique to prepare a pellet-based solid self-nanoemulsifying drug delivery system (SNEDDS) using cyclosporin A as a model of a poorly water-soluble drug. The rationale of this technique was to entrap a Liquid SNEDDS in the matrix of the coating material, polyvinylpyrrolidone K30, by fluid-bed coating. Pseudoternary phase diagrams were used to screen the liquid SNEDDS formulations. The optimal formulation was composed of Labrafil M(®) 1944 CS, Transcutol P(®), and Cremophor(®) EL in a ratio of 9:14:7. To prepare solid SNEDDS pellets, liquid SNEDDS was first dispersed in an aqueous solution of polyvinylpyrrolidone and then sprayed onto the surface of non-pareil pellets. Upon evaporation of water, polyvinylpyrrolidone precipitated and formed tight films to entrap the liquid SNEDDS. Visual observation and scanning electron microscopic analysis confirmed good appearance of the solid SNEDDS pellets. Our results indicated that up to 40% of the liquid SNEDDS could be entrapped in the coating layer. Powder x-ray diffraction analysis confirmed nonexistence of crystalline cyclosporin A in the formulation. Solid SNEDDS pellets showed a slower redispersion rate than the liquid SNEDDS. An increase in the total liquid SNEDDS loading led to faster redispersion, whereas increased coating weight (up to 400%) significantly decreased the redispersion rate. Both cyclosporin A loading and protective coating with 5% polyvinylpyrrolidone K30 did not significantly affect the redispersion rate. It is concluded that fluid-bed coating is a new technique with considerable potential for preparation of pellet-based solid SNEDDS formulations.

  18. Preparation, antibacterial effects and corrosion resistant of porous Cu–TiO{sub 2} coatings

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Haibo; Zhang, Xiangyu, E-mail: zhangxiangyu@tyut.edu.cn; Geng, Zhenhua; Yin, Yan; Hang, Ruiqiang; Huang, Xiaobo; Yao, Xiaohong; Tang, Bin

    2014-07-01

    Antibacterial TiO{sub 2} coatings with different concentrations of Cu (Cu–TiO{sub 2}) were prepared by micro-arc oxidation (MAO) on pre-sputtered CuTi films. The effect of Cu concentrations in CuTi films on the MAO process was investigated. The Cu–TiO{sub 2} coatings were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The corrosion resistance of Cu–TiO{sub 2} coatings was evaluated via potentiodynamic polarization method. The antibacterial properties were assessed by two methods: spread plate method and fluorescence staining. The experimental results demonstrate that the coatings are porous and consist of anatase phase, rutile phase and unoxidized titanium. The CuTi films are almost completely oxidized and the thickness of all MAO coatings is about 5–10 μm. Cu mainly exists as CuO in the TiO{sub 2} coatings. The Cu–TiO{sub 2} coatings exhibit excellent antibacterial activities, and the antibacterial rate gradually rise with the increase in Cu concentration in the MAO coatings. The corrosion resistance of MAO coatings is also improved slightly.

  19. Preparation and properties of silicone fouling release coatings with long-life afterglow fluorescent

    Directory of Open Access Journals (Sweden)

    Zhang Zhanping

    2017-01-01

    Full Text Available Based on polydimethylsiloxane, three-component coatings were prepared with different content of luminescence powder. The results showed that the illuminance of coatings increases with the content of luminescence powder, decays exponentially with the afterglow time, increases exponentially with the increase of exposure time. The afterglow illuminance augments with irradiated light illuminance. All coatings are hydrophobic and oleophilic. Surface free energy decreases with the increase of luminescence powder. They have highest impact-resistance and bend flexibility. The luminescence powder does not change obviously the shore hardness, tensile breaking strength, breaking elongation rate, elastic modular and roughness of coatings. The static test panels in sea generally could be covered obviously by biofouling including sponges, bryophytes and mussels, hydra, kelp, green algae after 2 months of immersion during growing season. But it never found that the barnacle attached on the coating surface during 4 years of immersion test. The static anti-fouling ability of the coatings is very limited. In addition, the sea creatures attached on the coating surface can be easily removed; even attached organisms will fall off and expose again the smooth coating surface. Consequently, all coatings with long-life afterglow fluorescent have a significant effect on preventing adhesion of barnacle and fouling-release performance.

  20. PREPARATION OF ZEOLITE X COATINGS ON SODA-LIME TYPE GLASS PLATES

    Directory of Open Access Journals (Sweden)

    M. Tatlier

    Full Text Available Abstract The dissolution of glass in highly alkaline reaction mixtures and the impact of this phenomenon on zeolite coating formation were investigated. Coating samples were prepared and characterized by X-ray diffraction (XRD, field emission gun scanning electron microscopy (FEGSEM and thermogravimetry (TG. It was demonstrated that zeolite X coatings might be prepared on soda-lime glass. Glass dissolved to some degree, up to 2% of its original mass, in the reaction mixtures for the conditions investigated. This dissolution affected the zeolite synthesis taking place on the glass surface, resulting in phases different from those obtained on inert metal surfaces in some cases, especially for the use of reaction mixtures with relatively high Si/Al ratios. The percentage of dissolution of glass plates increased with their decreasing thickness, indicating a surface phenomenon for the dissolution. The stabilities of the coatings, which varied with the synthesis conditions, benefited from the addition of extra thin layers of polyacrylic acid.

  1. Preparation of immobilized coating Fenton-like catalyst for high efficient degradation of phenol.

    Science.gov (United States)

    Wang, Jiankang; Yao, Zhongping; Wang, Yajing; Xia, Qixing; Chu, Huiya; Jiang, Zhaohua

    2017-05-01

    In this study, solid acid amorphous Fe 3 O 4 /SiO 2 ceramic coating decorated with sulfur on Q235 carbon steel as Fenton-like catalyst for phenol degradation was successfully prepared by plasma electrolytic oxidation (PEO) in silicate electrolyte containing Na 2 S 2 O 8 as sulfur source. The surface morphology and phase composition were characterized by SEM, EDS, XRD and XPS analyses. NH 3 -TPD was used to evaluate surface acidity of PEO coating. The results indicated that sulfur decorated amorphous Fe 3 O 4 /SiO 2 ceramic coatings with porous structure and higher acid strength had the similar pore size and the surface became more and more uneven with the increase of Na 2 S 2 O 8 in the silicate electrolyte. The Fenton-like catalytic activity of sulfur decorated PEO coatings was also evaluated. In contrast to negligible catalytic activity of sulfur undecorated PEO coating, catalytic activity of sulfur decorated PEO coating was excellent and PEO coating prepared with 3.0 g Na 2 S 2 O 8 had the highest catalytic activity which could degrade 99% of phenol within 8 min under circumneutral pH. The outstanding performance of sulfur decorated PEO coating was attributed to strong acidic microenvironment and more Fe 2+ on the surface. The strong acid sites played a key factor in determining catalytic activity of catalyst. In conclusion, rapid phenol removal under circumneutral pH and easier separation endowed it potential application in wastewater treatment. In addition, this strategy of preparing immobilized solid acid coating could provide guidance for designing Fenton-like catalyst with excellent catalytic activity and easier separation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. [Preparation and Characterization of Manganese and Fluorine Co-Modified Hydroxyapatite Composite Coating].

    Science.gov (United States)

    Zhang, Xue-jiao; Hao, Min; Qiao, Hai-xia; Zhang, Xiao-yun; Huang, Yong; Nian, Xiao-feng; Pang, Xiao-feng

    2016-03-01

    Titanium and titanium alloys have been widely used as orthopedic, dental implants and cardiovascular stents owing to their superior physical properties. However, titanium surface is inherently bio-inert, thus could not form efficient osseointegration with surrounding bone tissue. Therefore, to improve the surface property of titanium implant is significantly important in clinical application. Manganese and fluorine co-doped hydroxyapatite (FMnHAP) coatings were prepared on titanium substrate by electrochemical deposition technique. The as-prepared coatings were examined by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) tests. The results indicated that the FMnHAP coatings take the morphology of nanoscale-villous-like, the composite coating becomes more compact. The FTIR test indicated that the symmetry of bending vibration modes of hydroxyl changed, simulated body fluid immersion test proved that the FMnHAP coatings had induce carbonate-apatite formation, indicating that the composite coating possess excellent biocompatibility. In the electrochemical corrosion testing, the FMnHAP coatings showed stronger corrosion resistance than pure Ti.

  3. Electroless plating preparation and electromagnetic properties of Co-coated carbonyl iron particles/polyimide composite

    Science.gov (United States)

    Zhou, Yingying; Zhou, Wancheng; Li, Rong; Qing, Yuchang; Luo, Fa; Zhu, Dongmei

    2016-03-01

    To solve the serious electromagnetic interference problems at elevated temperature, one thin microwave-absorbing sheet employing Co-coated carbonyl iron particles and polyimide was prepared. The Co-coated carbonyl iron particles were successfully prepared using an electroless plating method. The microstructure, composition, phase and static magnetic properties of Co-coated carbonyl iron particles were characterized by combination of scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The electromagnetic parameters of Co-coated carbonyl iron particles/polyimide composite were measured in the frequency range of 2-18 GHz, and the electromagnetic loss mechanism of the material-obtained was discussed. The microwave absorption properties of composites before and after heat treatment at 300 °C for 100 h were characterized in 2-18 GHz frequency range. It was established that composites based on Co-coated carbonyl iron demonstrate thermomagnetic stability, indicating that Co coating reduces the oxidation of carbonyl iron. Thus, Co-coated carbonyl iron particles/polyimide composites are useful in the design of microwave absorbers operating at temperatures up to 300 °C.

  4. Easily recycled Bi2O3 photocatalyst coatings prepared via ball milling followed by calcination

    Science.gov (United States)

    Cheng, Lijun; Hu, Xumin; Hao, Liang

    2017-06-01

    Bi2O3 photocatalyst coatings derived from Bi coatings were first prepared by a two-step method, namely ball milling followed by the calcination process. The as-prepared samples were characterized by XRD, SEM, XPS and UV-Vis spectra, respectively. The results showed that monoclinic Bi2O3 coatings were obtained after sintering Bi coatings at 673 or 773 K, while monoclinic and triclinic mixed phase Bi2O3 coatings were obtained at 873 or 973 K. The topographies of the samples were observably different, which varied from flower-like, irregular, polygonal to nanosized particles with the increase in calcination temperature. Photodegradation of malachite green under simulated solar irradiation for 180 min showed that the largest degradation efficiency of 86.2% was achieved over Bi2O3 photocatalyst coatings sintered at 873 K. The Bi2O3 photocatalyst coatings, encapsulated with Al2O3 ball with an average diameter around 1 mm, are quite easily recycled, which provides an alternative visible light-driven photocatalyst suitable for practical water treatment application.

  5. Preparation of a Novel Water-based Acrylic Multi-Thermal Insulation Coating

    Directory of Open Access Journals (Sweden)

    Xiufang YE

    2017-08-01

    Full Text Available To efficiently improve the thermal insulation effect of coatings, a novel water-based acrylic multi-thermal insulation coating (multi-WATIC combined with thermal obstruction, echo, and radiation was prepared. The category and ratio of thermal insulation functional fillers are crucial. First, water-based acrylic thermal insulation coating (WATIC with single thermal insulation functional fillers was prepared, and the thermal insulation property tests were done. Thereafter, a novel multi-WATIC was prepared combined with the 3 thermal insulation functional fillers together, and the formula of the novel multi-WATIC was optimized based on single factor experiments by response surface methodology (RSM. Test results showed that multi-WATIC has excellent thermal insulation property, and the fitting result obtained by RSM is in good agreement with test data.DOI: http://dx.doi.org/10.5755/j01.ms.23.2.16090

  6. The promising application of graphene oxide as coating materials in orthopedic implants: preparation, characterization and cell behavior.

    Science.gov (United States)

    Zhao, Changhong; Lu, Xiuzhen; Zanden, Carl; Liu, Johan

    2015-02-10

    To investigate the potential application of graphene oxide (GO) in bone repair, this study is focused on the preparation, characterization and cell behavior of graphene oxide coatings on quartz substrata. GO coatings were prepared on the substrata using a modified dip-coating procedure. Atomic force microscopy (AFM), scanning electron microscopy (SEM) and Raman spectroscopy results demonstrated that the as-prepared coatings in this study were homogeneous and had an average thickness of ~67 nm. The rapid formation of a hydroxyapatite (HA) layer in the simulated body fluid (SBF) on GO coated substrata at day 14, as proved by SEM and x-ray diffraction (XRD), strongly indicated the bioactivity of coated substrata. In addition, MC3T3-E1 cells were cultured on the coated substrata to evaluate cellular activities. Compared with the non-coated substrata and tissue culture plates, no significant difference was observed on the coated substrata in terms of cytotoxicity, viability, proliferation and apoptosis. However, interestingly, higher levels of alkaline phosphatase (ALP) activity and osteocalcin (OC) secretion were observed on the coated substrata, indicating that GO coatings enhanced cell differentiation compared with non-coated substrata and tissue culture plates. This study suggests that GO coatings had excellent biocompatibility and more importantly promoted MC3T3-E1 cell differentiation and might be a good candidate as a coating material for orthopedic implants.

  7. Preparation and Thermal Characterization of Annealed Gold Coated Porous Silicon

    Directory of Open Access Journals (Sweden)

    Afarin Bahrami

    2012-01-01

    Full Text Available Porous silicon (PSi layers were formed on a p-type Si wafer. Six samples were anodised electrically with a 30 mA/cm2 fixed current density for different etching times. The samples were coated with a 50–60 nm gold layer and annealed at different temperatures under Ar flow. The morphology of the layers, before and after annealing, formed by this method was investigated by scanning electron microscopy (SEM. Photoacoustic spectroscopy (PAS measurements were carried out to measure the thermal diffusivity (TD of the PSi and Au/PSi samples. For the Au/PSi samples, the thermal diffusivity was measured before and after annealing to study the effect of annealing. Also to study the aging effect, a comparison was made between freshly annealed samples and samples 30 days after annealing.

  8. Preparation and characterization of TiO2 coated Fe nanofibers for electromagnetic wave absorber.

    Science.gov (United States)

    Jang, Dae-Hwan; Song, Hanbok; Lee, Young-In; Lee, Kun-Jae; Kim, Ki Hyeon; Oh, Sung-Tag; Lee, Sang-Kwan; Choa, Yong-Ho

    2011-01-01

    Recently, electromagnetic interference (EMI) and electromagnetic compatibility (EMC) have become serious problems due to the growth of electronic device and next generation telecommunication. It is necessary to develop new electromagnetic wave absorbing material to overcome the limitation of electromagnetic wave shielding materials. The EMI attenuation is normally related to magnetic loss and dielectric loss. Therefore, magnetic material coating dielectric materials are required in this reason. In this study, TiO2 coated Fe nanofibers were prepared to improve their properties for electromagnetic wave absorption. Poly(vinylpyrrolidone) (PVP) and Iron (III) nitrate nonahydrate (Fe(NO3)3 x 9H2O) were used as starting materials for the synthesis of Fe oxide nanofibers. Fe oxide nanofibers were prepared by electrospinning in an electric field and heat treatment. TiO2 layer was coated on the surface of Fe oxide nanofibers using sol-gel process. After the reduction of TiO2 coated Fe oxide nanofibers, Fe nanofibers with a TiO2 coating layer of about 10 nm were successfully obtained. The morphology and structure of fibers were characterized by SEM, TEM, and XRD. In addition, the absorption properties of TiO2 coated Fe nanofibers were measured by network analyzer.

  9. Preparation of Controlled-Release Fine Particles Using a Dry Coating Method.

    Science.gov (United States)

    Nakamura, Shohei; Sakamoto, Takatoshi; Ito, Tomonori; Kabasawa, Kazuhiro; Yuasa, Hiroshi

    2016-12-01

    Wet coating methods use organic solvents to prepare layered particles that provide controlled-release medications. However, this approach has disadvantages in that it can cause particle agglomeration, reduce pharmaceutical stability, and leave residual organic solvents. We used a dry coating method to overcome these issues. Fine particles (less than 50 μm in diameter) of controlled-release theophylline were created using theophylline (TP; model drug), polyethylene glycol 20,000 (PEG; drug fixative), hydrogenated castor oil (HCO; controlled-release material), hydrogenated rapeseed oil (HRSO; controlled-release material), and cornstarch (CS; core particle). An ultrahigh-speed mixer was employed to mix TP and CS for 5 min at 28,000 rpm. Subsequent addition of PEG produced single-core particles with a drug reservoir coating. Addition of HCO and HRSO to these particles produced a controlled-release layer on their surface, resulting in less than 10% TP dissolution after 8 h. We successfully demonstrated that this dry coating method could be used to coat 16-μm CS particles with a drug reservoir layer and a controlled-release layer, producing multi-layer coated single-core particles that were less than 50 μm in diameter. These can be used to prepare controlled-release tablets, capsules, and orally disintegrating tablets.

  10. Antimicrobial brass coatings prepared on poly(ethylene terephthalate) textile by high power impulse magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying-Hung, E-mail: tieamo2002@gmail.com; Wu, Guo-Wei; He, Ju-Liang

    2015-03-01

    The goal of this work is to prepare antimicrobial, corrosion-resistant and low-cost Cu65Zn35 brass film on poly(ethylene terephthalate) (PET) fabric by high-power impulse magnetron sputtering (HIPIMS), which is known to provide high-density plasma, so as to generate a strongly adherent film at a reduced substrate temperature. The results reveal that the brass film grows in a layer-plus-island mode. Independent of their deposition time, the obtained films retain a Cu/Zn elemental composition ratio of 1.86 and exhibit primarily an α copper phase structure. Oxygen plasma pre-treatment for 1 min before coating can significantly increase film adhesion such that the brass-coated fabric of Grade 5 or Grade 4–5 can ultimately be obtained under dry and wet rubbing tests, respectively. However, a deposition time of 1 min suffices to provide effective antimicrobial properties for both Staphylococcus aureus and Escherichia coli. As a whole, the feasibility of using such advanced HIPIMS coating technique to develop durable antimicrobial textile was demonstrated. - Highlights: • Prepare antimicrobial, corrosion-resistant and low-cost Cu65Zn35 brass film on PET fabric by HIPIMS • Brass-coated fabric with excellent durability, even undergone rubbing and washing tests • Brass-coated fabric provides effective antimicrobial properties for E. coli and S. aureus. • After brass coating, PET fabric still retained its mechanical property.

  11. Preparation of micro/nano-fibrous brushite coating on titanium via chemical conversion for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bing [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Ji’nan 250061 (China); School of Materials Science and Engineering, Shandong University, Ji’nan, 250061 (China); Suzhou Institute, Shandong University, Suzhou, 215123 (China); Guo, Yong-yuan [Orthopedic Department, Qilu Hospital of Shandong University, Ji’nan, 250012 (China); Xiao, Gui-yong [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Ji’nan 250061 (China); School of Materials Science and Engineering, Shandong University, Ji’nan, 250061 (China); Suzhou Institute, Shandong University, Suzhou, 215123 (China); Lu, Yu-peng, E-mail: biosdu@sdu.edu.cn [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Ji’nan 250061 (China); School of Materials Science and Engineering, Shandong University, Ji’nan, 250061 (China); Suzhou Institute, Shandong University, Suzhou, 215123 (China)

    2017-03-31

    Highlights: • A chemical conversion brushite coating was prepared on titanium. • The coating exhibits fibrous morphology in micro/nano-scale. • The surface of the coating shows high hydrophilicity and corrosion resistance in the simulated body fluid. • An improvement of cell response was observed on the surface of coated Ti compared to that of the uncoated. - Abstract: Calcium phosphate coatings have been applied on the surface of Ti implants to realize better osseointegration. The formation of dicalcium phosphate dihydrate (CaHPO{sub 4}·2H{sub 2}O), mineralogically named brushite on pure Ti substrate has been investigated via chemical conversion method. Coating composition and microstructure have been investigated by X-ray diffractometer, Fourier transform infrared spectrometer and field emission scanning electron microscope. The results reveal that the coatings are composed of high crystalline brushite with minor scholzite (CaZn{sub 2}(PO{sub 4}){sub 2}·2H{sub 2}O). A micro/nano-scaled fibrous morphology can be produced in the acidic chemical conversion bath with pH 5.00. The surface of the fibrous brushite coating exhibits high hydrophilicity and corrosion resistance in the simulated body fluid. The osteoblast cells grow and spread actively on the coated samples and the proliferation numbers and alkaline phosphate activities of the cells improve significantly compared to the uncoated Ti. It is suggested that the micro/nano-fibrous brushite coating can be a potential approach to improve the osteoinductivity and osteoconductivity of Ti implant, due to its similarity in morphology and dimension to inorganic components of biological hard tissues, and favorable responses to the osteoblasts.

  12. Reversed preparation of low-density poly(divinylbenzene/styrene) foam columns coated with gold films

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Yinhai; Wang, Ni; Li, Yaling; Yao, Mengqi; Gan, Haibo; Hu, Wencheng, E-mail: huwc@uestc.edu.cn

    2016-06-15

    Highlights: • A reversed fabrication of low density foam columns coated with gold films was proposed. • The uniformity in thickness and purity of gold film are easy to be controlled. • A compact layer is prepared through an electrophoretic deposition method. • A low density (12 mg/cc) foam column coated with gold film is obtained. - Abstract: This work aims to fabricate low-density, porous, non-conductive, structural poly(divinylbenzene/styrene) foam columns by high-internal-phase emulsion templating. We prepare these non-conductive foam columns coated with a thin gold layer by electrochemical deposition and the reversed preparation technique. As expected, the density of the foam obtained through this novel method was about 12 mg cm{sup −3}, and the thickness of the gold coating was about 3 μm. We performed field emission scanning electron microscopy to morphologically and microstructurally characterize the products and X-ray diffraction and energy dispersive spectroscopy to determine the composition of the gold coating.

  13. Nanosilica reinforced epoxy floor coating composites: preparation and thermophysical characterization

    Directory of Open Access Journals (Sweden)

    Mir Mohammad Alavi Nikje

    2012-01-01

    Full Text Available In this study, flooring grade epoxy/nanoSiO2 nanocomposites were prepared by in-situ polymerization method. Nano silica was treated by coupling agent in order to surface treating and introducing of reactive functional groups to achieving adequate bonding between polar inorganic nano particles and epoxy organic polymer. γ-Aminopropyltriethoxysilane (Amino A-100 was used as an effective and commercially available coupling agent and nano silica treated in acetone media. SEM observations of cured samples revealed that the nano silica was completely dispersed into polymer matrix into nanoscale particles. Thermal and physical properties of prepared samples were investigated and data showed improvements in physical and mechanical properties of the flooring samples in comparison with unfilled resin.

  14. Antibacterial properties of nano-silver coated PEEK prepared through magnetron sputtering.

    Science.gov (United States)

    Liu, Xiuju; Gan, Kang; Liu, Hong; Song, Xiaoqing; Chen, Tianjie; Liu, Chenchen

    2017-09-01

    significantly improve the antibacterial activity and bacterial adhesion ability of the PEEK samples. The compact and homogeneous nano-silver coating was successfully prepared on the surface of PEEK through magnetron sputtering. The nano-silver coated PEEKs demonstrated enhanced antibacterial activities and bacterial adhesion abilities and had no cytotoxic effects. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  15. Preparation and characterization of dense graphite/glassy carbon composite coating for sealing application

    Science.gov (United States)

    Wang, Yang; Chen, Zhaofeng; Yu, Shengjie; Pan, Ning; Liao, Jiahao

    2017-09-01

    Glassy carbon (GC), characterized by a homogeneous structure and glass-like fracture surface once broken, has attracted increasing attention because of its excellent performance. In this paper, a dense graphite/glassy carbon composite coating with low gas permeability was introduced. In this composite coating, small graphite particles acting as second phase were wrapped by glassy carbon matrix. The composite coatings with different mass fractions of graphite particles were prepared. The mass loss of phenolic resin was determined by TG (thermogravimetry) analysis to determine the pyrolysis process. Raman spectrum analysis indicates that graphite content in composite coatings affected the G/D ratio significantly. The permeability of composite coatings with 50% and 100% graphite particles was almost same, which was ranged from 6  ×  10-13 m3 · µm/m2 · s · Pa to 3  ×  10-13 m3 · µm/m2 · s · Pa within the differential pressure from 100 kPa to 70 kPa. While the composite coating with 150% graphite particles had higher gas permeability due to the tiny micro-cracks and micro-pores produced. What was more, the densification mechanism of graphite/glassy carbon composite coating was also discussed in detail.

  16. Preparation of carbon-coated TiO{sub 2} nanostructures for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang-Jun [Materials Research Center for Energy and Green Technology, Andong National University, Andong, Gyungbuk 760-745 (Korea, Republic of); Kim, Hansu [Department of Energy Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Kim, Young-Jun [Advanced Battery Research Center, Korea Electronics Technology Institute, Seongnam, Gyeonggi 463-816 (Korea, Republic of); Lee, Hyukjae, E-mail: hlee@andong.ac.kr [Materials Research Center for Energy and Green Technology, Andong National University, Andong, Gyungbuk 760-745 (Korea, Republic of)

    2011-06-01

    Highlights: > We prepare carbon-coated TiO{sub 2} nanotubes/nanowires by one-pot hydrothermal method. > Carbon coating increases electronic conductivity at higher calcination temperatures. > Carbon coating suppresses the agglomeration of nanotubes at lower calcination temperatures. - Abstract: Carbon-coated TiO{sub 2} one-dimensional nanostructures are synthesized by hydrothermal reaction followed by post-calcination at various temperatures. Post-calcination induces crystallization of TiO{sub 2} and the complete crystallization of anatase phase is observed at 600 deg. C of the calcination temperature. Carbon-coated TiO{sub 2} nanostructures show relatively poor crystallinity as compared with the pristine counterparts, but their lithiation capacity and high rate capability are improved throughout all calcination temperatures. The coated carbon suppresses severe agglomeration of TiO{sub 2} nanotubes which allows easy access of Li-ions and electrons to the whole surface of primary nanotubes, leading to the better lithiation performance. Higher calcination temperatures cause excessive growth of nanotube walls, leading to the collapse of tubular morphology and deterioration of lithiation performance. At 700 deg. C of the calcination temperature, the enhanced electronic conductivity from the graphitization of the coated carbon seems to be the main reason for the improved capacity of TiO{sub 2} nanowires.

  17. Strong Antibacterial Polydopamine Coatings Prepared by a Shaking-assisted Method

    Science.gov (United States)

    Su, Lei; Yu, Yang; Zhao, Yanshuang; Liang, Feng; Zhang, Xueji

    2016-04-01

    Strong antibacterial polydopamine (PDA) coatings prepared by a facile shaking-assisted method is reported for the first time. It was found that a minor modification made to the conventional synthesis procedure of PDA coatings, viz. replacing the static solution condition with a shaking solution condition by using a mechanical shaker, can produce the roughened polydopamine (rPDA) coatings at different substrates, e.g., glass, stainless steel, plastic, and gauze. The resulting rPDA coatings were characterized with Raman spectrum, zeta-potential analysis and contact angle measurement. The antibacterial activity of the rPDA coatings was evaluated by a shake flask test with gram-positive Staphylococcus aureus, and gram-negative Escherichia coli and Pseudomonas aeruginosa as bacteria models. Testing results revealed that, in the absence of any other antibacterial agents, the rPDA coatings exhibited remarkably enhanced antibacterial activities. In addition, such enhanced antibacterial activities of the rPDA coatings were found to be unimpaired by steam sterilization treatments.

  18. The approaches to thin film preparation and TEM observations on slurry Si-modified aluminide coatings

    Energy Technology Data Exchange (ETDEWEB)

    Shirvani, K. [Materials Eng. Group, Department of Design and Manufacturing, New Technologies Institute, Iranian Research Organization for Science and Technology, Tehran 18815-3538 (Iran); Saremi, M. [Department of Metallurgy and Materials Engineering, Faculty of Engineering, University of Tehran, North Amirabad, Tehran (Iran); Yamamoto, Y. [Department of Metallurgy and Ceramics Science, Graduate School of Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2006-02-15

    Transmission electron microscopy (TEM) can be used as a precision characterization tool to identify very small precipitates in diffusion aluminide coatings. However, in order to successfully prepare the appropriate samples for TEM observation, often non-traditional thin film preparation techniques need to be employed. In this work, two sample preparation methods of twin jet electro-polishing and ion milling were experienced to characterize fine precipitates (< 1 {mu}m), in Si-aluminide coatings applied on Ni-base superalloy In-738LC by slurry technique. These precipitates are concentrated throughout the topcoat zone. It was found that the preparation of thin film exactly from the outer zone of the coating is only possible using ion milling process. The ion-milled specimens were utilized to observe by JEOL high resolution TEM operating at an accelerating voltage of 300 kV. Electron diffraction patterns, bright field and EDS were used to identify the precipitate phases as well as the coating matrix. The results showed that the fine precipitates are typically chromium silicides in nature, mostly as Cr{sub 3}Si and CrSi, distributed in the {beta}-NiAl matrix phase. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  19. Preparation, characterization, and biological properties of organic-inorganic nanocomposite coatings on titanium substrates prepared by sol-gel.

    Science.gov (United States)

    Catauro, Michelina; Bollino, Flavia; Papale, Ferdinando

    2014-02-01

    When surface-reactive (bioactive) coatings are applied to medical implants by means of the sol-gel dip-coating technique, the biological proprieties of the surface of the implant can be locally modified to match the properties of the surrounding tissues to provide a firm fixation of the implant. The aim of this study has been to synthesize, via sol-gel, organoinorganic nanoporous materials and to dip-coat a substrate to use in dental applications. Different systems have been prepared consisting of an inorganic zirconium-based matrix, in which a biodegradable polymer, the poly-ε-caprolactone was incorporated in different percentages. The materials synthesized by the sol-gel process, before gelation, when they were still in sol phase, have been used to coat a titanium grade 4 (Ti-4) substrate to change its surface biological properties. Thin films have been obtained by means of the dip-coating technique. A microstructural analysis of the obtained coatings was performed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy. The biological proprieties have been investigated by means of tests in vitro. The bone-bonding capability of the nanocomposite films has been evaluated by examining the appearance of apatite on their surface when plunged in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma. The examination of apatite formation on the nanocomposites, after immersion in SBF, has been carried out by SEM equipped with energy-dispersive X-ray spectroscopy. To evaluate cells-materials interaction, human osteosarcoma cell line (Saos-2) has been seeded on specimens and cell vitality evaluated by WST-8 assay. © 2013 Wiley Periodicals, Inc.

  20. Matrix compatible solid phase microextraction coating, a greener approach to sample preparation in vegetable matrices.

    Science.gov (United States)

    Naccarato, Attilio; Pawliszyn, Janusz

    2016-09-01

    This work proposes the novel PDMS/DVB/PDMS fiber as a greener strategy for analysis by direct immersion solid phase microextraction (SPME) in vegetables. SPME is an established sample preparation approach that has not yet been adequately explored for food analysis in direct immersion mode due to the limitations of the available commercial coatings. The robustness and endurance of this new coating were investigated by direct immersion extractions in raw blended vegetables without any further sample preparation steps. The PDMS/DVB/PDMS coating exhibited superior features related to the capability of the external PDMS layer to protect the commercial coating, and showed improvements in terms of extraction capability and in the cleanability of the coating surface. In addition to having contributed to the recognition of the superior features of this new fiber concept before commercialization, the outcomes of this work serve to confirm advancements in the matrix compatibility of the PDMS-modified fiber, and open new prospects for the development of greener high-throughput analytical methods in food analysis using solid phase microextraction in the near future. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Preparation and Testing of Corrosion and Spallation-Resistant Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, John

    2015-11-01

    This Energy & Environmental Research Center (EERC) project is designed to determine if plating APMT®, a specific highly oxidation-resistant oxide dispersion-strengthened FeCrAl alloy made by Kanthal, onto nickel-based superalloy turbine parts is a viable method for substantially improving the lifetimes and maximum use temperatures of the parts. The method for joining the APMT plate to the superalloys is called evaporative metal bonding and involves placing a thin foil of zinc between the plate and the superalloy, clamping them together, and heating in an atmosphere-controlled furnace. Upon heating, the zinc melts and dissolves the oxide skins of the alloys at the bond line, allowing the two alloys to diffuse into each other. The zinc then diffuses through the alloys and evaporates from their surfaces. During this annual reporting period, the finite element model was completed and used to design clamping jigs to hold the APMT plate to the larger blocks of superalloys during the bonding process. The clamping system was machined from titanium–zirconium–molybdenum and used to bond the APMT plate to the superalloy blocks. The bond between the APMT plate was weak for one of each of the superalloy blocks. We believe that this occurred because enough oxidation had occurred on the surface of the parts as a result of a 1-month time period between sandblasting to prepare the parts and the actual bonding process. The other blocks were, therefore, bonded within 1 day of preparing the parts for bonding, and their joints appear strong. Scanning electron microscopy analyses of representative joints showed that no zinc remained in the alloys after bonding. Also, phases rich in hafnium and tantalum had precipitated near the bond line in the APMT. Iron from the APMT had diffused into the superalloys during bonding, more extensively in the CM247LC than in the Rene 80. Nickel from the superalloys had diffused into the APMT, again more extensively in the joint with the CM247LC than

  2. Enteric-coating of pulsatile-release HPC capsules prepared by injection molding.

    Science.gov (United States)

    Macchi, E; Zema, L; Maroni, A; Gazzaniga, A; Felton, L A

    2015-04-05

    Capsular devices based on hydroxypropyl cellulose (Klucel® LF) intended for pulsatile release were prepared by injection molding (IM). In the present work, the possibility of exploiting such capsules for the development of colonic delivery systems based on a time-dependent approach was evaluated. For this purpose, it was necessary to demonstrate the ability of molded cores to undergo a coating process and that coated systems yield the desired performance (gastric resistance). Although no information was available on the coating of IM substrates, some issues relevant to that of commercially-available capsules are known. Thus, preliminary studies were conducted on molded disks for screening purposes prior to the spray-coating of HPC capsular cores with Eudragit® L 30 D 55. The ability of the polymeric suspension to wet the substrate, spread, start penetrating and initiate hydration/swelling, as well as to provide a gastroresistant barrier was demonstrated. The coating of prototype HPC capsules was carried out successfully, leading to coated systems with good technological properties and able to withstand the acidic medium with no need for sealing at the cap/body joint. Such systems maintained the original pulsatile release performance after dissolution of the enteric film in pH 6.8 fluid. Therefore, they appeared potentially suitable for the development of a colon delivery platform based on a time-dependent approach. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Study on the Preparation of a High-Efficiency Carbon Fiber Dissipating Coating

    Directory of Open Access Journals (Sweden)

    Jing Li

    2017-07-01

    Full Text Available The working temperature of electronic components directly determines their service life and stability. In order to ensure normal operation of electronic components, cooling the coating is one of the best ways to solve the problem. Based on an acrylic amino-resin system, a dissipating coating was prepared with carbon fiber (CF as the main thermal conductive filler. The influence of the CF content on the thermal conductivity was determined by the single factor method. The surface structure was observed by scanning electron microscopy (SEM. The results show: With the increase of the CF mass fraction, both the heat dispersion and heat conduction coefficient of the coating tend to increase at first and then decrease, and the heat dissipation effect is optimum when the CF mass fraction is 12.3 wt %. At this point, the coating shows an excellent comprehensive performance, such as 1st level adhesion, H grade hardness, and thermal conductivity of 1.61 W/m·K. Furthermore, this paper explored the radiating mechanism of coating in which CF produces a coating which forms a heat “channel” for rapid heat conduction. When the optimal value is exceeded, the cooling effect is reduced because of the accumulation and the anisotropy of CF.

  4. Preparation and characterization of the micro-arc oxidation composite coatings on magnesium alloys

    Directory of Open Access Journals (Sweden)

    Yanfeng Ge

    2014-12-01

    Full Text Available The magnesium alloys attract the light-weight manufacture due to its high strength to weight ratio, however the poor corrosion resistance limits the application in automobile industry. The Micro-arc Composite Ceramic (MCC coatings on AZ91D magnesium alloys were prepared by Micro-arc Oxidation (MAO and electrophoresis technologies. The microstructure, corrosion resistance, abrasion resistance, stone impact resistance and adhesion of MCC coatings were studied respectively. The cross section morphologies showed that the outer organic coating was filled into the hole on surface of MAO coating, and it acted as a shelter against corrosive products. The copper-accelerated acetic acid salt spray Test, abrasion resistance test, stone impact resistance test, thermal shock resistance test and adhesion test were used to evaluate the protective characterization by the third testing organization which approved by GM. The test results showed the composite coatings meet all the requirements. The MCC coating on Mg presents excellent properties, and it is a promising surface treatment technology on magnesium alloys for production vehicles.

  5. SiC Conversion Coating Prepared from Silica-Graphite Reaction

    Directory of Open Access Journals (Sweden)

    Back-Sub Sung

    2017-01-01

    Full Text Available The β-SiC conversion coatings were successfully synthesized by the SiO(v-graphite(s reaction between silica powder and graphite specimen. This paper is to describe the effects on the characteristics of the SiC conversion coatings, fabricated according to two different reaction conditions. FE-SEM, FE-TEM microstructural morphologies, XRD patterns, pore size distribution, and oxidation behavior of the SiC-coated graphite were investigated. In the XRD pattern and SAD pattern, the coating layers showed cubic SiC peak as well as hexagonal SiC peak. The SiC coatings showed somewhat different characteristics with the reaction conditions according to the position arrangement of the graphite samples. The SiC coating on graphite, prepared in reaction zone (2, shows higher intensity of beta-SiC main peak (111 in XRD pattern as well as rather lower porosity and smaller main pore size peak under 1 μm.

  6. Preparation and characterization of a GPTMS/graphene coating on AA-2024 alloy

    Science.gov (United States)

    Dun, Yuchao; Zuo, Yu

    2017-09-01

    A γ-(2,3-epoxypropoxy) propyltrimethoxysilane/graphene (GPTMS/rGO) coating on AA-2024 aluminum alloy was prepared by immersing the aluminum alloy sample in a silane/graphene oxide solution and curing in oven at 180 °C. Silanol groups were grafted onto graphene oxide sheets during hydrolysis. The graphene oxide was stacked layer by layer through silanol groups. The synthesized coating was characterized with Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Raman spectra and scanning electron microscopy. The thickness of the composite coating increased greatly compared with that of silane coating, due to the mutual riveting effect. The covalent metallic-siloxane bonds (AlOSi) improved the adhesion force greatly. The laminate structure of graphene increased the hardness and declined the brittleness over 200 °C. The GPTMS/rGO coating showed good corrosion resistance. In 3.5% NaCl solution the anodic current density of the aluminum alloy sample with GPTMS/rGO coating was reduced by several orders of magnitude compared with those of bare aluminum alloy or the sample with graphene film.

  7. Factors influencing the preparation of silver-coated glass frit with polyvinyl-pyrrolidone

    Science.gov (United States)

    Xiang, Feng; Gan, Weiping

    2018-01-01

    In this work, a new electroless silver plating method for the synthesis of silver-coated glass frit composite powders with good morphology has been proposed and the polyvinyl-pyrrolidone (PVP) was used the activating agent. It was found that the weight ratio of PVP to glass frit affected the distribution and number of silver nanoparticles. Moreover, the loading capacity of the glass frit, the pH value and reaction temperature could influence the size of the silver nanoparticles and morphology of silver on the surface of glass frit. The as-prepared silver-coated glass frit was used to prepare a silver paste using an optimized process to form silver nanoparticles with uniform size and high density. The silver paste with silver-coated glass frit increased the photovoltaic conversion efficiency of silicon solar cells by 0.271% compared with the silver paste prepared with pure glass frit. The silver nanoparticles can promoted the precipitation of Ag crystallites on the silicon wafer. Therefore, the silver-coated glass frit can further optimize and enhance the electrical performance of solar cells.

  8. Optimization of coating solution for preparation of antibacterial copper-polyethylene nanocomposite

    Science.gov (United States)

    Ghorbani, Hamid Reza; Molaei, Mazaher

    2017-06-01

    Polyethylene film was coated with copper nanoparticles and its antibacterial properties were investigated. To make nanocomposite film, the solutions containing the copper nanoparticles were prepared using polyamide resin in six different concentrations of copper nanoparticles (1%, 2%, 3%, 5%, 7% and 10 wt%). Corona discharge was used to improve the nonpolar surface of polyethylene and prepare it for coating. Corona discharge was carried out in 5 min with power of 10 000 W. Characterisation of nanoparticles and the coated surface were performed using dynamic light scattering (DLS), x-ray diffraction (XRD) and scanning electron microscope (SEM). The antibacterial activity of polyethylene-copper nanocomposite against two type of bacteria including gram-negative Escherichia coli and gram-positive Staphylococcus aureus was measured by disc-diffusion method. In addition, the optimum concentration of copper nanoparticles was determined about 5 wt%. The current technique of coated film preparation reduces the amount of required nanoparticles which finally offers lower production cost.

  9. Preparation and Surface Modification of Silica Nanoparticles for Superhydrophopic Coating

    Directory of Open Access Journals (Sweden)

    Noor Hadi Aysa

    2017-12-01

    Full Text Available Silica  nanoparticles are well-known to be one of the multifunctional inorganic compounds which are widely used in medical applications. The aim of this study is to prepare the particles of nano silica oxide with particle size ranging from 20-25 nm. In the present study, surface modification of Silica nanoparticles was performed, and influence of modification on the structure and morphological properties was investigated. The resulting  nanoparticles were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM and atomic force microscopy (AFM.  Silica nanoparticles with the average diameter of about 20 nm were modified with oleic acid, as coupling agents, in order to modify their surface properties and make them more waterproof dispersible in the organic area. Among the results is that the  surface modification of the   Silica nano-particles leads to more dispersion in the organic medium which indicates better organic synthesis.One of the results obtained,is that modified silica-nanoparticles can be used effectively in environmental and safety applications and can be used in future medical applications as wound stick that prevent water from reaching the wound and then prevent  an inflamation.

  10. Preparation and characterization of chitosan-silver/hydroxyapatite composite coatings onTiO2 nanotube for biomedical applications

    Science.gov (United States)

    Yan, Yajing; Zhang, Xuejiao; Li, Caixia; Huang, Yong; Ding, Qiongqiong; Pang, Xiaofeng

    2015-03-01

    A biocomposite coating containing chitosan, silver, and hydroxyapatite was developed on anodized titanium substrate by electrochemical deposition. Coatings were characterized by field-emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and polarisation studies. Results showed that the prepared coatings had compact and dense morphology with a thickness of 6.2 ± 0.7 μm and that silver was evenly distributed. Testing the prepared coatings with Gram-positive and Gram-negative bacterial strains exhibited antibacterial activity because of the synergistic effect of silver and chitosan. The prepared coatings were also found to be nontoxic to MC3T3-E1 cells. These results suggested that chitosan/silver-hydroxyapatite biocomposite coatings can prevent the bacterial infection of implants.

  11. Microstructure evolution and mechanical properties of TiCN-Cr nano/micro composite coatings prepared by reactive plasma spraying

    Science.gov (United States)

    Zhang, Fanyong; He, Jining; Chen, Kai; Qin, Yanfang; Li, Chao; Yin, Fuxing

    2018-01-01

    Nanostructured TiCN based composite coatings with various Cr content were prepared by reactive plasma spray (RPS) from mixed powder (Ti-graphite + Cr) under nitrogen atmosphere. Results showed that composite coatings consisted mainly of TiC0.7N0.3 phase and residual metal Cr. Metal Cr plates were homogeneously embedded in TiCN matrix with good interface bond. The TiCN-Cr composite coatings exhibited lower porosity than TiCN coatings, but increasing porosity with excess Cr addition (30 wt.%). The TiCN-20 wt.% Cr coating showed the highest hardness (1309 HV0.2) among composite coatings, slight lower than the TiCN matrix coating (1526 HV0.2). Compared with the TiCN matrix coating, the TiCN-Cr composite coatings showed higher variability in surface microhardness distribution. The TiCN-Cr composite coatings showed slight higher friction coefficients (0.4-0.6) than TiCN matrix coating (0.35). The wear resistance of TiCN-Cr composite coatings was improved with less mass loss compared with TiCN coating under the test load of 400 N. The TiCN-Cr composite coatings with high Cr content showed the mixture of abrasive and adhesive wear.

  12. Preparation and evaluation of duloxetine hydrochloride enteric-coated pellets with different enteric polymers

    Directory of Open Access Journals (Sweden)

    Chen Kuang

    2017-05-01

    Full Text Available The main purpose of the present study was to prepare duloxetine hydrochloride (DXH enteric-coated pellets using different enteric polymers. Three layers (drug-loaded layer, barrier layer, and enteric-coated layer were applied to the inert core pellets, successively. The optimal formulation was manufactured by employing suspension layering method in fluidized bed processor (FBP with varieties of enteric polymers like Aqoat® AS-LF, Eudragit® L30D55 and HPMCP-HP55. The prepared pellets were measured for physical characterization and the in vitro dissolution profile. Scanning electron microscopy (SEM was conducted to observe the morphology of pellets, and different kinetic models were applied to analyze the release mechanism of Cymbalta® and home-made pellets. The coating weight gain of enteric-coated layer containing Eudragit® L30D55, Aqoat® AS-LF and HP-55 were determined to be 35%, 26% and 24%, respectively. The similarity factors (f2 of self-made capsules with above polymers and commercially available capsules (Cymbalta® were above 50 in the dissolution medium of pH 6.8 phosphate buffer solution (PBS. SEM figures showed the smooth surfaces of self-prepared pellets using Eudragit® L30D55 and Aqoat® AS-LF, whereas rough surface was found in the HP-55 pellets at day 0, and an impurity was appearing in the condition of 40 °C/75% relative humidity for 1 month. In conclusion, the pellets prepared by utilizing Eudragit® L30D55 and Aqoat® AS-LF were the optimal preparations based on the dissolution profile and stability.

  13. Preparation and magnetic properties of Ni–P–La coating by electroless plating on silicon substrate

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Yun [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Wang, Jihui, E-mail: jhwang@tju.edu.cn [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Yuan, Jing [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); College of Physics and Electronic Information Engineering, Qinghai University for Nationalities, Xining, Qinghai 810007 (China); Li, Haiqin [College of Physics and Electronic Information Engineering, Qinghai University for Nationalities, Xining, Qinghai 810007 (China)

    2016-02-28

    Graphical abstract: The content of Ni phase, which is the main ferromagnetic phase in Ni–P–La coating, is almost increased linearly with the concentration of La in plating solution. - Highlights: • The La element improves the magnetic properties of Ni–P–La coating. • Magnetism increases but the stability of bath decreases with La content and pH. • Coatings peel off at high temperature (≥80 °C) and magnetism is weak in short time. • The optimum is the La{sub 2}O{sub 3} of 10 mg L{sup −1}, pH of 5.0, temperature of 75 °C and time of 45 min. - Abstract: Ni–P–La coatings were prepared on Si substrate by electroless plating method under different La content, pH value, plating temperature and plating time. The surface morphology, chemical composition, structure and magnetic properties of coatings were observed and determined by scanning electron microscope (SEM), energy dispersive X-ray spectrometry (EDS), X-ray diffractometer (XRD) and vibrating sample magnetometer (VSM). The results showed that Ni–P–La coating is smooth and uniform with a cellular morphology grown in columnar manner. With the increase of La content, pH value and plating time, the thickness and saturation magnetization of coating are increased continuously, but the stability of plating bath is decreased greatly with La content and pH value. Under higher plating temperature, the thickness and saturation magnetization of coatings are obviously enhanced. But too high plating temperature is harmful to the plating bath and coating. The optimum plating conditions for Ni–P–La coating is La{sub 2}O{sub 3} addition of 10 mg L{sup −1}, pH value of 5.0, plating temperature of 75 °C and plating time of 45 min. The role of La element is to benefit the deposition of Ni element, promote the formation of Ni phase during the annealing process, and thus improve the magnetic properties of Ni–P–La coating.

  14. Preparation and testing of corrosion and spallation-resistant coatings

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, John P. [Univ. of North Dakota, Grand Forks, ND (United States); Cavalli, Matthew N. [Univ. of North Dakota, Grand Forks, ND (United States)

    2016-06-30

    its standard oxidation, spallation, and corrosion testing, which was scheduled for completion in the spring of 2016. However, because of commercial demands, the tests were not completed by the time of this report except some initial spallation tests at 1150°C. In those tests, several of the APMT plates separated from the CM247LC, likely because of the remaining aluminum oxide scale on the surface of the CM247LC. This implies that surface preparation may need to include machining to remove the oxide scale before bonding rather than just sandblasting. In previous tensile testing at 950°C, the breaks in the tensile samples always occurred in the APMT and not at the joints. Gasifier sampling was completed to determine what types of trace contaminants may occur in cleaned and combusted syngas and that could lead to corrosion or deposition in turbines firing coal syngas. The sampling was done from a pressurized fluidized-bed gasifier and a pressurized entrained-flow gasifier. The particles captured on a filter from syngas were typically 0.2 to 0.5 μm in diameter, whereas those captured from the combusted syngas were slightly larger and more spherical. X-ray photoelectron spectroscopy done at Oak Ridge National Laboratory showed that the particles do not contain any metals and have an atomic composition almost identical to that of the polycarbonate filter. This indicates that the particles are primarily soot-based and not formed from volatilization of metals in the gasifiers.

  15. Preparation of bilayer-core osmotic pump tablet by coating the indented core tablet.

    Science.gov (United States)

    Liu, Longxiao; Xu, Xiangning

    2008-03-20

    In this paper, a bilayer-core osmotic pump tablet (OPT) which does not require laser drilling to form the drug delivery orifice is described. The bilayer-core consisted of two layers: (a) push layer and (b) drug layer, and was made with a modified upper tablet punch, which produced an indentation at the center of the drug layer surface. The indented tablets were coated by using a conventional pan-coating process. Although the bottom of the indentation could be coated, the side face of the indentation was scarcely sprayed by the coating solution and this part of the tablet remained at least partly uncoated leaving an aperture from which drug release could occur. Nifedipine was selected as the model drug. Sodium chloride was used as osmotic agent, polyvinylpyrrolidone as suspending agent and croscarmellose sodium as expanding agent. The indented core tablet was coated by ethyl cellulose as semipermeable membrane containing polyethylene glycol 400 for controlling the membrane permeability. The formulation of core tablet was optimized by orthogonal design and the release profiles of various formulations were evaluated by similarity factor (f(2)). It was found that the optimal OPT was able to deliver nifedipine at an approximate zero-order up to 24 h, independent on both release media and agitation rates. The preparation of bilayer-core OPT was simplified by coating the indented core tablet, by which sophisticated technology of the drug layer identification and laser drilling could be eliminated. It might be promising in the field of preparation of bilayer-core OPT.

  16. Solid self-nanoemulsifying cyclosporin A pellets prepared by fluid-bed coating: preparation, characterization and in vitro redispersibility

    OpenAIRE

    Lei Y; Lu Y.; Qi J; Nie S; Hu F; Pan W; Wu W

    2011-01-01

    Yang Lei1,2, Yi Lu2, Jianping Qi2, Sufang Nie1, Fuqiang Hu3, Weisan Pan1, Wei Wu21School of Pharmacy, Shenyang Pharmaceutical University, Shenyang; 2School of Pharmacy, Fudan University, Shanghai; 3School of Pharmacy, Zhejiang University, Hangzhou, Zhejiang, People’s Republic of ChinaBackground: The objective of this study was to evaluate fluid-bed coating as a new technique to prepare a pellet-based solid self-nanoemulsifying drug delivery system (SNEDDS) using cyclosporin A as a m...

  17. Preparation and characterizations of bioglass ceramic cement/Ca-P coating on pure magnesium for biomedical applications.

    Science.gov (United States)

    Zhang, Xue; Li, Xiao-Wu; Li, Ji-Guang; Sun, Xu-Dong

    2014-01-08

    Magnesium has been recently recognized as a biodegradable metal for bone substitute applications. In order to improve the biocompatibility and osteointegration of pure Mg, two kinds of coatings, i.e., the Ca-P coating and bioglass ceramic cement (BGCC)/Ca-P coating, were prepared on the pure Mg ribbons in the present work. The Ca-P coating was obtained by aqueous solution method. Subsequently, Ca-P coated Mg was immersed into the BGCC slurry, which was prepared by the mix of SiO2-CaO-P2O5 bioglass ceramic (BGC) powders and phosphate liquid with a liquid-to-solid ratio (L/S) of 1.6, to obtain BGCC/Ca-P coating by a dipping-pulling method. The microstructures, morphologies, and compositions of these coatings have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS). The effect of these coatings on the mineralization activity of pure Mg has been investigated. The results indicated that both the Ca-P coating and BGCC/Ca-P coating could promote the nucleation of osteoconductive minerals, i.e., bone-like apatite, and the hydroxyapatite (HA) layer formed on the surface of the BGCC/Ca-P coating is obviously more dense, thick, and stable than that formed on the Ca-P coating after immersion in SBF solution for 15 days. The potentiodynamic polarization test indicated that the corrosion current density of the BGCC/Ca-P coated Mg is obviously lower than that of the Ca-P coating and 10 times lower than that of uncoated Mg. These results demonstrated that the BGCC/Ca-P coating can increase significantly the corrosion resistance of Mg and introduce a high biocompatibility of the bone-Mg substrate interface. In summary, the newly developed BGCC/Ca-P coated Mg has a good potential for biomedical applications.

  18. Preparation, characterization and dynamical mechanical properties of dextran-coated iron oxide nanoparticles (DIONPs).

    Science.gov (United States)

    Can, Hatice Kaplan; Kavlak, Serap; ParviziKhosroshahi, Shahed; Güner, Ali

    2017-04-20

    Dextran-coated iron oxide nanoparticles (DIONPs) with appropriate surface chemistry exhibit many interesting properties that can be exploited in a variety of biomedical applications such as magnetic resonance imaging (MRI) contrast enhancement, tissue repair, hyperthermia, drug delivery and in cell separation. This paper reports the experimental detail for preparation, characterization and investigation of thermal and dynamical mechanical characteristics of the dextran-coated Fe3O4 magnetic nanoparticles. In our work, DIONPs were prepared in a 1:2 ratio of Fe(II) and Fe(III) salt in the HCl solution with NaOH at given temperature. The obtained dextran-coated iron-oxide nanoparticles structure-property correlation was characterized by spectroscopic methods; attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and XRD. Coating dextran on the iron-oxide proof of important peaks can be seen from the ATR-FTIR. Dramatic crystallinity increment can be observed from the XRD pattern of the iron-oxide dextran nanoparticles. The thermal analysis was examined by differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and differential thermal analysis (DTA). Dynamical mechanical properties of dextran nanoparticles were analysed by dynamic mechanical analysis (DMA). Thermal stability of the iron oxide dextran nanoparticles is higher than that of the dextran.

  19. Enteric-coated sustained-release nanoparticles by coaxial electrospray: preparation, characterization, and in vitro evaluation

    Science.gov (United States)

    Hao, Shilei; Wang, Bochu; Wang, Yazhou; Xu, Yingqian

    2014-02-01

    Enteric-coated formulations can delay the release of drugs until they have passed through the stomach. However, high concentration of drugs caused by rapidly released in the small intestine leads to the intestinal damage, and frequent administration would increase the probability of missing medication and reduce the patient compliance. To solve the above-mentioned problems, aspirin-loaded enteric-coated sustained-release nanoparticles with core-shell structure were prepared via one-step method using coaxial electrospray in this study. Eudragit L100-55 as pH-sensitive polymer and Eudragit RS as sustained-release polymer were used for the outer coating and inner core of the nanoparticles, respectively. The maximum loading capacity of nanoparticles was 23.66 % by changing the flow rate ratio of outer/inner solutions, and the entrapment efficiency was nearly 100 %. Nanoparticles with core-shell structure were observed via fluorescence microscope and transmission electron microscope. And pH-sensitive and sustained drug release profiles were observed in the media with different pH values (1.2 and 6.8). In addition, mild cytotoxicity in vitro was detected, and the nanoparticles could be taken up by Caco-2 cells within 1.0 h in cellular uptake study. These results indicate that prepared enteric-coated sustained-release nanoparticles would be a more safety and effective carrier for oral drug delivery.

  20. PREPARING OF THE CHAMELEON COATING BY THE ION JET DEPOSITION METHOD

    Directory of Open Access Journals (Sweden)

    Jakub Skocdopole

    2017-07-01

    Full Text Available Preparation of chameleon coatings using an Ionized Jet Deposition (IJD technique is reported in the present paper. IJD is a new flexible method for thin film deposition developed by Noivion, Srl. The chameleon coatings are thin films characterised by a distinct change of their tribological properties according to the external conditions. The deposited films of SiC and TiN materials were examined by the Raman spectroscopy, SEM and XPS. The results of the Raman spectroscopy have proved an amorphous structure of SiC films. The data from XPS on TiN films have shown that the films are heavily oxidized, but also prove that the films are composed of TiN and pure Ti. The SEM provided information about the size of grains and particles constituting the deposited films, which is important for tribological properties of the films. Deposition of the chameleon coating is very complex problem and IJD could be ideal method for preparation of this coating.

  1. Preparation and characterization of chitosan-silver/hydroxyapatite composite coatings onTiO{sub 2} nanotube for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yajing [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Zhang, Xuejiao [Medical Informatics, Hebei North University, Zhangjiakou 075000 (China); Li, Caixia [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Huang, Yong [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); College of Lab Medicine, Hebei North University, Zhangjiakou 075000 (China); Ding, Qiongqiong [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Pang, Xiaofeng, E-mail: xfpang@aliyun.com [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2015-03-30

    Highlights: • Chitosan/silver-doped hydroxyapatite biocomposite coating was successfully deposited on anodized Ti by electrochemical deposition. • The chemical state of silver in the synthesized coatings was studied by XPS peak deconvolution. • The synthesized coatings have excellent antibacterial activity because of synergistic effect of the Ag and CS. • The CSAgHAp coatings showed good biocompatibility and no adverse effect in cell culture tests. - Abstract: A biocomposite coating containing chitosan, silver, and hydroxyapatite was developed on anodized titanium substrate by electrochemical deposition. Coatings were characterized by field-emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and polarisation studies. Results showed that the prepared coatings had compact and dense morphology with a thickness of 6.2 ± 0.7 μm and that silver was evenly distributed. Testing the prepared coatings with Gram-positive and Gram-negative bacterial strains exhibited antibacterial activity because of the synergistic effect of silver and chitosan. The prepared coatings were also found to be nontoxic to MC3T3-E1 cells. These results suggested that chitosan/silver-hydroxyapatite biocomposite coatings can prevent the bacterial infection of implants.

  2. Preparation and characterization of silica coated iron oxide magnetic nano-particles.

    Science.gov (United States)

    Li, Ying-Sing; Church, Jeffrey S; Woodhead, Andrea L; Moussa, Filsun

    2010-09-01

    Iron oxide magnetic nano-particles have been prepared by precipitation in an aqueous solution of iron(II) and iron(III) chlorides under basic condition. Surface modifications have been carried out by using tetraethoxysilane (TEOS) and mercaptopropyltrimethoxysilane (MPTMS). The uncoated and coated particles have been characterized with transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy, thermal gravimetric analysis (TGA), and infrared (IR) and Raman spectroscopy. The particle sizes as measured from TEM images were found to have mean diameters of 13nm for the uncoated and about 19nm for the coated particles. The measured IR spectra of the uncoated and MPTMS coated particles showed the conversion of magnetite to hematite at high temperature. The results obtained from both IR spectroscopy and TGA revealed that the mercaptopropylsilyl group in the MPTMS coated magnetite decomposed at 600 degrees C and the silica layer of the TEOS coated magnetite was rather stable. Raman spectroscopy has shown the laser heating effect through the conversion of magnetite to maghemite and hematite. Copyright 2010 Elsevier B.V. All rights reserved.

  3. Preparation and Properties of Superamphiphobic Wear-resistance PPS-based Coating

    Directory of Open Access Journals (Sweden)

    WANG Huai-yuan

    2017-01-01

    Full Text Available Superamphiphobic wear-resistance PPS-based coatings were prepared by a simple spraying method with a pore-forming reagent of NH4HCO3 and nano-filler of carbon nanotubes (CNTs.The surface morphology and the hydrophobicity,oleophobicity of the coating were analyzed by scanning electron microscope (SEM and contact angle meter.The wear-resistance of the coating was verified by sanding method with given load.The results indicate that a rough surface is obtained after pore-forming,and the porous structures in combination with the CNTs construct the special micro/nano-scale network structures.When the mass fraction of NH4HCO3 is 5%,the contact angles of the coating for water,glycerine and ethylene glycol are 162°,158° and 152°,showing superamphiphobic property.After polished 10000 times by abrasive paper,the coating shows slight friction marks and remains high hydrophobicity,exhibiting excellent wear-resistance.

  4. Preparation and performance of thermal insulation energy saving coating materials for exterior wall.

    Science.gov (United States)

    Wang, Fei; Liang, Jinsheng; Tang, Qingguo; Chen, Gong; Chen, Yalei

    2014-05-01

    Nano zinc oxide with a high refractive index has good thermal reflection performance, hollow glass microspheres have good thermal reflection and insulation performance, and sepiolite nanofibers with many nanostructural pores have good thermal insulation performance. The dispensability of nano zinc oxide in coating materials was improved by optimizing surface silane coupling agent modification process, leading to the good thermal reflection performance. The thermal insulation performance was improved by hollow glass microspheres and sepiolite nanofibers. On this basis, the thermal insulation coating materials were prepared by exploring the effect of amount, complex mode, and other factors of the above three kinds of functional fillers on the thermal reflection and insulation performance of coating materials. The results showed that the surface modification effect of nano zinc oxide was the best when the silane coupling agent addition was 6%. The reflection and insulation performance of the coatings were the best when the additions of modified nano zinc oxide, hollow glass microspheres, and sepiolite nanofibers were 3%, 4%, and 4%, respectively. Compared with the control coating materials, the thermal insulation effect was improved obviously, which was evaluated by the -13.5 degrees C increase of maximum temperature difference between the upper and the lower surfaces.

  5. Amorphous calcium phosphate nanospheres/polylactide composite coated tantalum scaffold: facile preparation, fast biomineralization and subchondral bone defect repair application.

    Science.gov (United States)

    Zhou, Rong; Xu, Wei; Chen, Feng; Qi, Chao; Lu, Bing-Qiang; Zhang, Hao; Wu, Jin; Qian, Qi-Rong; Zhu, Ying-Jie

    2014-11-01

    Calcium phosphate (CaP) materials are widely used in various biomedical areas such as drug/gene delivery and bone repair/tissue engineering. In this study, amorphous CaP nanospheres synthesized by a simple co-precipitation method are used to prepare the CaP-polylactide (CaP-PLA) composite. Then, the as-prepared CaP-PLA composite is used to coat tantalum (Ta) plates and porous scaffolds. Compared with bare Ta plate, CaP-PLA coated Ta plates show a high performance of surface biomineralization in simulated body fluid (SBF). In addition, the hydrophilicity of the CaP-PLA coated Ta plates is significantly improved. CaP-PLA coated Ta plates with bovine serum albumin (BSA) are prepared and used for the investigation of BSA release in vitro. The experimental results indicate a sustained BSA release property and simultaneous biomineralization of the as-prepared BSA-containing CaP-PLA coated Ta plates. Furthermore, CaP-PLA coated Ta scaffolds are favorable for the human osteoblast-like MG63 cells adhesion and spreading. The vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-containing CaP-PLA coated porous Ta scaffolds are used for the study of rabbit subchondral bone defect repair, covering with autogeneic periosteums. The as-prepared CaP-PLA composite coated Ta scaffolds are useful to guide the bone regeneration in vivo. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Preparation of suspensions of phospholipid-coated microbubbles by coaxial electrohydrodynamic atomization.

    Science.gov (United States)

    Farook, U; Stride, E; Edirisinghe, M J

    2009-03-06

    The use of phospholipid-coated microbubbles for medical applications is gaining considerable attention. However, the preparation of lipid-coated microbubble suspensions containing the ideal size and size distribution of bubbles still represents a considerable challenge. The most commonly used preparation methods of sonication and mechanical agitation result in the generation of polydisperse microbubbles with diameters ranging from less than 1 microm to greater than 50 microm. Efforts have been made via distinctly different techniques such as microfluidic and electrohydrodynamic bubbling to prepare lipid-coated microbubbles with diameters less than 10 microm and with a narrow size distribution, and recent results have been highly promising. In this paper, we describe a detailed investigation of the latter method that essentially combines liquid and air flow, and an applied electric field to generate microbubbles. A parametric plot was constructed between the air flow rate (Qg) and the lipid suspension flow rate (Ql) to identify suitable flow rate regimes for the preparation of phospholipid-coated microbubbles with a mean diameter of 6.6 microm and a standard deviation of 2.5 microm. The parametric plot has also helped in developing a scaling equation between the bubble diameter and the ratio Qg/Ql. At ambient temperature (22 degrees C), these bubbles were very stable with their size remaining almost unchanged for 160 min. The influence of higher temperatures such as the human body temperature (37 degrees C) on the size and stability of the microbubbles was also explored. It was found that the mean bubble diameter fell rapidly to begin with but then stabilized at 1-2 microm after 20 min.

  7. A Descriptive Overview of Japanese Shipbuilding Surface Preparation and Coating Methods

    Science.gov (United States)

    1982-09-01

    can best be summarized simply as the application of logic to the business of ship- building. For example, Ishikawajima - Harima Heavy Industries Co. Ltd...Japanese surface preparation and coating methods applicable to U.S. ship- yards. The project is subcontracted to IHI Marine Technology, Ishikawajima - Harima ... Heavy Industries Co., Ltd. (IHI) Japan and Chugoku Marine Paint, Ltd. The project report entitled Zone Painting Method should be published by the end

  8. Preparation and Photocatalytic Properties of SnO2 Coated on Nitrogen-Doped Carbon Nanotubes

    OpenAIRE

    Lingling Wang; Long Shen; Luping Zhu; Haiying Jin; Naici Bing; Lijun Wang

    2012-01-01

    SnO2 nanoparticles coated on nitrogen-doped carbon nanotubes were prepared successfully via a simple wet-chemical route. The as-obtained SnO2/CNx composites were characterized using X-ray powder diffraction, scanning electron microscopy, and transmission electron microscopy. The photocatalytic activity of as-prepared SnO2/CNx for degradation Rhodamine B under UV light irradiation was investigated. The results show that SnO2/CNx nanocomposites have a higher photocatalytic activity than pure Sn...

  9. Preparation of Coated Valproic Acid and Sodium Valproate Sustained-release Matrix Tablets.

    Science.gov (United States)

    Phaechamud, T; Mueannoom, W; Tuntarawongsa, S; Chitrattha, S

    2010-03-01

    The aim of this research was to investigate the technique for preparation of coated valproic acid and sodium valproate sustained-release matrix tablets. Different diluents were tested and selected as the effective absorbent for oily valproic acid. Effect of the amount of absorbent and hydroxypropylmethylcellulose on drug release from valproic acid-sodium valproate matrix tablets prepared with wet granulation technique was evaluated in pH change system. Colloidal silicon dioxide effectively adsorbed liquid valproic acid during wet granulation and granule preparation. The amounts of colloidal silicon dioxide and hydroxypropylmethylcellulose employed in tablet formulations affected drug release from the tablets. The drug release was prominently sustained for over 12 h using hydroxypropylmethylcellulose-based hydrophilic matrix system. The mechanism of drug release through the matrix polymer was a diffusion control. The drug release profile of the developed matrix tablet was similar to Depakine Chrono(®), providing the values of similarity factor (f2) and difference factor (f1) of 85.56 and 2.37, respectively. Eudragit(®) L 30 D-55 was used as effective subcoating material for core matrix tablets before over coating with hydroxypropylmethylcellulose film with organic base solvent. Drug release profile of coated matrix tablet was almost similar to that of Depakine Chrono(®).

  10. Preparation and characterizations of naproxen-loaded magnetic nanoparticles coated with PLA- g-chitosan copolymer

    Science.gov (United States)

    Thammawong, C.; Sreearunothai, P.; Petchsuk, A.; Tangboriboonrat, P.; Pimpha, N.; Opaprakasit, P.

    2012-08-01

    Naproxen (NPX) drug-loaded magnetic nanoparticles (MNPs) have been prepared in a one-step process utilizing a biocompatible polylactide-grafted-chitosan copolymer. The copolymer serves both as a NPX drug carrier as well as a polymeric surfactant for the synthesis of MNPs without the use of any additional surfactant. Highly stable MNPs with high magnetization in the form of maghemite (γ-Fe2O3) are prepared in aqueous media. Effects of preparation conditions on structures and properties of the copolymer-coated and drug-loaded MNPs are investigated by employing particle size and zeta potential measurements, transmission electron microscopy, vibrating sample magnetometer, X-ray diffraction, Fourier-transform infrared, nuclear magnetic resonance, and confocal Raman spectroscopy. The results show that average particle size (150-300 nm), coating efficiency, and coating structures of the resulting MNPs materials are strongly dependent on MNP/copolymer and MNP/NPX ratios in feed. It is also observed that NPX acts as co-surfactant in the drug-loading process, resulting in different encapsulating structures with the variation in the MNP/copolymer and MNP/NPX ratios. Properties of the MNPs materials can be further optimized for use in specific biomedical applications.

  11. [Preparation and structural detection of antibacterial hydroxyapatite coating material on Ti implant].

    Science.gov (United States)

    Zhu, Zi-Yuan; Zhang, Fu-Qiang; Zheng, Xue-Bin

    2006-10-01

    To investigate the method for preparing antibacterial hydroxyapatite coating material on Ti implant,and detect its surface feature, chemical composition and the crystal structure. The antibacterial hydroxyapatite coating material which contained silver-zirconium phosphate antimicrobial was prepared on the Ti implant by using vacuum plasma spraying technology. Samples were divided into 4 groups according to weight percent of the antimicrobial: group A (0), group B (2%), group C (5%) and group D (10%). The surface feature of each sample was observed under scanning electric microscope. The chemical composition and the crystal structure was detected by electronic probe and X-ray diffraction method respectively. The surface feature of each sample showed globular granule with caky structure and air pore. The crystal structure of group A, B, C mainly showed characteristic absorption band of Ca10(OH)2(PO4)6 which degraded while antimicrobial content increased. Except Ca10(OH)2(PO4)6 and CaZr (PO4)2, Na6CaP2O09 also appeared in group D. Ag+ could not be detected by electronic probe in group A and B. The contents of Ag+ in group C and D were similar. The antibacterial hydroxyapatite coating material which contained silver can be prepared on the Ti implant by using vacuum plasma spraying technology. The appropriate weight percent of the antimicrobial was 5%.

  12. Preparation and characterizations of naproxen-loaded magnetic nanoparticles coated with PLA-g-chitosan copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Thammawong, C.; Sreearunothai, P. [Thammasat University, School of Bio-Chemical Engineering and Technology, Sirindhorn International Institute of Technology (SIIT) (Thailand); Petchsuk, A. [National Metal and Materials Technology Center (MTEC) (Thailand); Tangboriboonrat, P. [Mahidol University, Department of Chemistry, Faculty of Science (Thailand); Pimpha, N. [National Nanotechnology Center (NANOTEC) (Thailand); Opaprakasit, P., E-mail: pakorn@siit.tu.ac.th [Thammasat University, School of Bio-Chemical Engineering and Technology, Sirindhorn International Institute of Technology (SIIT) (Thailand)

    2012-08-15

    Naproxen (NPX) drug-loaded magnetic nanoparticles (MNPs) have been prepared in a one-step process utilizing a biocompatible polylactide-grafted-chitosan copolymer. The copolymer serves both as a NPX drug carrier as well as a polymeric surfactant for the synthesis of MNPs without the use of any additional surfactant. Highly stable MNPs with high magnetization in the form of maghemite ({gamma}-Fe{sub 2}O{sub 3}) are prepared in aqueous media. Effects of preparation conditions on structures and properties of the copolymer-coated and drug-loaded MNPs are investigated by employing particle size and zeta potential measurements, transmission electron microscopy, vibrating sample magnetometer, X-ray diffraction, Fourier-transform infrared, nuclear magnetic resonance, and confocal Raman spectroscopy. The results show that average particle size (150-300 nm), coating efficiency, and coating structures of the resulting MNPs materials are strongly dependent on MNP/copolymer and MNP/NPX ratios in feed. It is also observed that NPX acts as co-surfactant in the drug-loading process, resulting in different encapsulating structures with the variation in the MNP/copolymer and MNP/NPX ratios. Properties of the MNPs materials can be further optimized for use in specific biomedical applications.

  13. Microstructures and properties of Cr-Cu/W-Cu bi-layer composite coatings prepared by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiaping; Feng, Xiaomei; Shen, Yifu; Chen, Cheng; Duan, Cuiyuan [Nanjing Univ. of Aeronautics and Astronautics (China). Dept. of Materials Science and Technology

    2016-06-15

    Cr-Cu/W-Cu bi-layer coatings with composite structures were fabricated by means of mechanical alloying. The Cr-Cu layer and the W-Cu layer were deposited successively and the as-synthesized bi-layer coating was made up of an inner Cr-Cu layer and an outer W-Cu layer. Microstructures, chemical and phase compositions of the as-prepared coatings were characterized. The results indicated that the bonding between the inner coating and the substrate was improved with the increase of Cu in the raw powder. The annealing treatment of the inner Cr-Cu layer was beneficial to the bonding between the inner Cr-Cu coating and the outer W-Cu coating layer. Mechanical properties such as microhardness, friction and wear resistance were tested. The as-synthesized coating could effectively improve the hardness and wear resistance of the Cu substrate.

  14. UV-curable nanocasting technique to prepare bioinspired superhydrophobic organic-inorganic composite anticorrosion coatings

    Directory of Open Access Journals (Sweden)

    K. C. Chang

    2015-02-01

    Full Text Available A UV-curing technique was used to develop advanced anticorrosive coatings made of a poly(methyl methacrylate (PMMA/silica composite (PSC with bioinspired Xanthosoma sagittifolium leaf-like superhydrophobic surfaces. First of all, a transparent soft template with negative patterns of xanthosoma sagittifolium leaf can be fabricated by thermally curing the polydimethylsiloxane (PDMS pre-polymer in molds at 60°C for 4 h, followed by detaching PDMS template from the surface of natural leaf. PSC coatings with biomimetic structures can be prepared by performing the UV-radiation process upon casting UV-curable precursor with photo-initiator onto cold-rolled steel (CRS electrode under PDMS template. Subsequently, UV-radiation process was carried out by using light source with light intensity of 100 mW/cm2 with exposing wavelength of 365 nm. Surface morphologies of the as-synthesized hydrophobic PMMA (HP and superhydrophobic PSC (SPSC coatings showed a large number of micro-scaled mastoids, each decorated with many nano-scaled wrinkles that were systematically investigated by using scanning electron microscopy (SEM. The contact angles of water droplets on the sample surfaces can be increased from ~81 and 103° on PMMA and PSC surfaces to ~148 and 163° on HP and SPSC surfaces, respectively. The SPSC coating was found to provide an advanced corrosion protection effect on CRS electrodes compared to that of neat PMMA, PSC, and HP coatings based on a series of electrochemical corrosion measurements in 3.5 wt% NaCl electrolyte. Enhanced corrosion protection of SPSC coatings on CRS electrodes can be illustrated by that the silica nanoparticles on the small papillary hills of the bioinspired structure of the surface further increased the surface roughness, making the surface exhibit superior superhydrophobic, and thus leading to much better anticorrosion performance.

  15. Aluminium-12wt% silicon coating prepared by thermal spraying technique: Part 2 microstructure and properties

    Directory of Open Access Journals (Sweden)

    Jiansirisomboon, S.

    2006-03-01

    Full Text Available At present, thermal spray technology has been widely used as an alternative method for wear protection in materials by applying coated layer on an original worn surface. This research studied the thermal sprayed Al-12wt%Si coating prepared by flame spray technique. This material has been known as a candidate for wear resistance in particularly an automobile industry. In this research, the most suitable spraying condition had been achieved by a design of experiment which was 38 ft3/hr (1.026 m3/hr of oxygen flow rate, 27 ft3/hr (0.729 m3/hr of acetylene flow rate and 58 mm of spray distance. The as-sprayed coating had a hardness of 87.0±8.3 HV, thickness of 236.7±20.5 μm, percentage volume fraction of porosity of 14.99± 1.63 and wear rate of 1.108x10-3 ± 0.001 mm3/m. Microstructure of the coating was also investigated.

  16. Preparation and characterization of controlled-release fertilizers coated with marine polysaccharide derivatives

    Science.gov (United States)

    Wang, Jing; Liu, Song; Qin, Yukun; Chen, Xiaolin; Xing, Rong'e.; Yu, Huahua; Li, Kecheng; Li, Pengcheng

    2017-09-01

    Encapsulation of water-soluble nitrogen fertilizers by membranes can be used to control the release of nutrients to maximize the fertilization effect and reduce environmental pollution. In this research, we formulated a new double-coated controlled-release fertilizer (CRF) by using food-grade microcrystalline wax (MW) and marine polysaccharide derivatives (calcium alginate and chitosan-glutaraldehyde copolymer). The pellets of water-soluble nitrogen fertilizer were coated with the marine polysaccharide derivatives and MW. A convenient and eco-friendly method was used to prepare the CRF. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the morphology and composition of the products. The nitrogen-release properties were determined in water using UV-Vis spectrophotometry. The controlled-release properties of the fertilizer were improved dramatically after coating with MW and the marine polysaccharide derivatives. The results show that the double-coated CRFs can release nitrogen in a controlled manner, have excellent controlled-release features, and meet the European Standard for CRFs.

  17. Preparation and characterization of porous carbon material-coated solid-phase microextraction metal fibers.

    Science.gov (United States)

    Zhu, Fang; Guo, Jiaming; Zeng, Feng; Fu, Ruowen; Wu, Dingcai; Luan, Tiangang; Tong, Yexiang; Lu, Tongbu; Ouyang, Gangfeng

    2010-12-10

    Two kinds of porous carbon materials, including carbon aerogels (CAs), wormhole-like mesoporous carbons (WMCs), were synthesized and used as the coatings of solid-phase microextraction (SPME) fibers. By using stainless steel wire as the supporting core, six types of fibers were prepared with sol-gel method, direct coating method and direct coating plus sol-gel method. Headspace SPME experiments indicated that the extraction efficiencies of the CA fibers are better than those of the WMC fibers, although the surface area of WMCs is much higher than that of CAs. The sol-gel-CA fiber (CA-A) exhibited excellent extraction properties for non-polar compounds (BTEX, benzene, toluene, ethylbenzene, o-xylene), while direct-coated CA fiber (CA-B) presented the best performance in extracting polar compounds (phenols). The two CA fibers showed wide linear ranges, low detection limits (0.008-0.047μgL(-1) for BTEX, 0.15-5.7μgL(-1) for phenols) and good repeatabilities (RSDs less than 4.6% for BTEX, and less than 9.5% for phenols) and satisfying reproducibilities between fibers (RSDs less than 5.2% for BTEX, and less than 9.9% for phenols). These fibers were successfully used for the analysis of water samples from the Pearl River, which demonstrated the applicability of the home-made CA fibers. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. AFM characterization of solid-supported lipid multilayers prepared by spin-coating.

    Science.gov (United States)

    Pompeo, G; Girasole, M; Cricenti, A; Cattaruzza, F; Flamini, A; Prosperi, T; Generosi, J; Castellano, A Congiu

    2005-06-15

    Lipids are the principal components of biologically relevant structures as cellular membranes. They have been the subject of many studies due to their biological relevance and their potential applications. Different techniques, such as Langmuir-Blodgett and vesicle-fusion deposition, are available to deposit ordered lipid films on etched surfaces. Recently, a new technique of lipid film deposition has been proposed in which stacks of a small and well-controlled number of bilayers are prepared on a suitable substrate using a spin-coater. We studied the morphological properties of multi-layers made of cationic and neutral lipids (DOTAP and DOPC) and mixtures of them using dynamic mode atomic force microscopy (AFM). After adapting and optimizing, the spin-coating technique to deposit lipids on a chemically etched Silicon (1,0,0) substrate, a morphological nanometer-scale characterization of the aforementioned samples has been provided. The AFM study showed that an initial layer of ordered vesicles is formed and, afterward, depending on details of the spin-coating preparation protocol and to the dimension of the silicon substrate, vesicle fusion and structural rearrangements of the lipid layers may occur. The present data disclose the possibility to control the lipid's structures by acting on spin-coating parameters with promising perspectives for novel applications of lipid films.

  19. Silica coating of luminescent quantum dots prepared in aqueous media for cellular labeling

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yunfei; Li, Yan, E-mail: yli@ecust.edu.cn; Zhong, Xinhua, E-mail: zhongxh@ecust.edu.cn

    2014-12-15

    Graphical abstract: A facile route based on modified Stöber method was used for the synthesis of silica coated QDs (QD@SiO{sub 2}) starting from aqueously prepared CdTe/CdS QDs. The resultant QD@SiO{sub 2} exhibited a significant increase in emission efficiency compared with that of the initial QDs, along with a small size (∼5 nm in diameter), great stability and low cytotoxicity, which makes it a good candidate as robust biomarker. - Highlights: • We present a facile modified Stöber method to prepare highly luminescent QD@SiO{sub 2}. • The PL efficiency of QDs increases significantly after silica coating. • QD@SiO{sub 2} exhibits small size (∼5 nm) and great dispersibility in aqueous solution. • QD@SiO{sub 2} presents extraordinary photo and colloidal stability. • The silica shell eliminates QD cytotoxicity, providing the access of bioconjugation. - Abstract: Silica coating is an effective approach for rendering luminescent quantum dots (QDs) with water dispersibility and biocompatibility. However, it is still challenging to prepare silica-coated QDs (QD@SiO{sub 2}) with high emission efficiency, small size and great stability in favor for bioapplication. Herein, we reported a modified Stöber method for silica coating of aqueously-prepared CdTe/CdS QDs. With the coexistence of Cd{sup 2+} and thioglycolic acid (TGA), a thin silica shell was formed around QDs by the hydrolysis of tetraethyl orthosilicate (TEOS). The resultant QD@SiO{sub 2} with a small size (∼5 nm in diameter) exhibits significantly higher emission efficiencies than that of the initial QDs. Also, QD@SiO{sub 2} has extraordinary photo and colloidal stability (pH range of 5–13, 4.0 M NaCl solution). Protected by the silica shell, the cytotoxicity of QDs could be reduced. Moreover, the QD@SiO{sub 2} conjugated with folic acid (FA) presents high specific binding toward receptor-positive HeLa cells over receptor-negative A549 cells.

  20. The Bcl-2 homologue Buffy rescues α-synuclein-induced Parkinson disease-like phenotypes in Drosophila.

    Science.gov (United States)

    M'Angale, P Githure; Staveley, Brian E

    2016-05-18

    In contrast to the complexity found in mammals, only two Bcl-2 family genes have been found in Drosophila melanogaster including the pro-cell survival, human Bok-related orthologue, Buffy. The directed expression of α-synuclein, the first gene identified to contribute to inherited forms of Parkinson disease (PD), in the dopaminergic neurons (DA) of flies has provided a robust and well-studied Drosophila model of PD complete with the loss of neurons and accompanying motor defects. To more fully understand the biological basis of Bcl-2 genes in PD, we altered the expression of Buffy in the dopamine producing neurons with and without the expression of α-synuclein, and in the developing neuron-rich eye. To alter the expression of Buffy in the dopaminergic neurons of Drosophila, the Ddc-Gal4 transgene was used. The directed expression of Buffy in the dopamine producing neurons resulted in flies with increased climbing ability and enhanced survival, while the inhibition of Buffy in the dopaminergic neurons reduced climbing ability over time prematurely, similar to the phenotype observed in the α-synuclein-induced Drosophila model of PD. Subsequently, the expression of Buffy was altered in the α-synuclein-induced Drosophila model of PD. Analysis revealed that Buffy acted to rescue the associated loss of locomotor ability observed in the α-synuclein-induced model of PD, while Buffy RNA interference resulted in an enhanced α-synuclein-induced loss of climbing ability. In complementary experiments the overexpression of Buffy in the developing eye suppressed the mild rough eye phenotype that results from Gal4 expression and from α-synuclein expression. When Buffy is inhibited the roughened eye phenotype is enhanced. The inhibition of Buffy in DA neurons produces a novel model of PD in Drosophila. The directed expression of Buffy in DA neurons provide protection and counteracts the α-synuclein-induced Parkinson disease-like phenotypes. Taken all together this

  1. Preparation and Characterization of FC Films Coated on PET Substrates by RF Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Huang Mei-lin

    2018-01-01

    Full Text Available Fluorocarbon (FC films were prepared on polyethylene terephthalate (PET plates and PET fabrics respectively by a radiofrequency (RF magnetron sputtering technique using polytetrafluoroethylene (PTFE as a target. Scanning electron microscope and X-ray photoelectron spectroscopy were used to investigate the morphology, structure and composition of the obtained FC films. The hydrophobicity and uvioresistant properties of the FC film coated fabric were studied. The results show that the FC films were successfully deposited on the PET substrates by a RF magnetron sputtering. The deposited films are made up of four components -CF3, -CF2-, CF- and -C-. The proportions of the four components and surface morphologies of the deposited films vary with the sputtering conditions. Compared with the original fabric samples, the hydrophobicity of the FC film coated fabrics is quite good and improved significantly.

  2. Poly(aryl ethers) and related polysiloxane copolymer molecular coatings: preparation and radiation degradation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mcgrath, J.E.

    1982-05-01

    The radiation degradation of poly(arylene ether sulfones) and related materials is studied. These basic studies are important both as a means to developing stronger, more stable matrix resins for composite materials, as well as to improve the data base in regard to chemical structure-physical property relationships. Thirty homo and copolymers were synthesized, at least partially characterized and, in several cases suitable film casting techniques were developed. Four samples were chosen for initial radiation degradation. Poly(dimethyl siloxane) soft bocks/segments can preferentially migrate to the surface of copolymer films. Since siloxanes are utilized as thermal control coatings, this form of 'molecular' coating is of interest. The chemistry for preparing such copolymers with any of the polymers described was demonstrated.

  3. One-Step Method for Preparation of Magnetic Nanoparticles Coated with Chitosan

    Directory of Open Access Journals (Sweden)

    Karla M. Gregorio-Jauregui

    2012-01-01

    Full Text Available Preparation of magnetic nanoparticles coated with chitosan in one step by the coprecipitation method in the presence of different chitosan concentrations is reported here. Obtaining of magnetic superparamagnetic nanoparticles was confirmed by X-ray diffraction and magnetic measurements. Scanning transmission electron microscopy allowed to identify spheroidal nanoparticles with around 10-11 nm in average diameter. Characterization of the products by Fourier transform infrared spectroscopy demonstrated that composite chitosan-magnetic nanoparticles were obtained. Chitosan content in obtained nanocomposites was estimated by thermogravimetric analysis. The nanocomposites were tested in Pb2+ removal from a PbCl2 aqueous solution, showing a removal efficacy up to 53.6%. This work provides a simple method for chitosan-coated nanoparticles obtaining, which could be useful for heavy metal ions removal from water.

  4. Composite coating prepared by micro-arc oxidation followed by sol-gel process and in vitro degradation properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yi [School of Mechanical Engineering and Automation, Beihang University, Beijing 100083 (China); Bai Kuifeng; Fu Zhenya [Research Center for Materials, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002 (China); Zhang Caili [Department of Civil and Architecture Engineering, Zhongyuan University of Technology, Zhengzhou, 450007 (China); Zhou Huan; Wang Liguo; Zhu Shijie; Guan Shaokang [Research Center for Materials, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002 (China); Li Dongsheng [School of Mechanical Engineering and Automation, Beihang University, Beijing 100083 (China); Hu Junhua, E-mail: hujh@zzu.edu.cn [School of Mechanical Engineering and Automation, Beihang University, Beijing 100083 (China); Research Center for Materials, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002 (China)

    2012-01-15

    A Mg phosphate coating was prepared on home-developed Mg-Zn-Ca alloy to improve its anticorrosion performance in simulated body fluid (SBF, Kokubo solution). The coating was prepared by micro-arc oxidation (MAO) method at the working voltage of 120-140 V. Evident improvement of anticorrosion was obtained even through the surface was porous. To further diminish the contact with SBF, a TiO{sub 2} layer was coated on the porous MAO layer by sol-gel dip coating followed by an annealing treatment. The coatings were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS). The electrochemical performance of the MAO and TiO{sub 2}/MAO coated alloys was evaluated by anodic polarization measurements. The pores on Mg phosphate layer provided accommodation sites for the subsequent TiO{sub 2} sol-gel coating which sealed the pores and hence significantly enhanced the anticorrosion while single MAO coating only improve anticorrosion within a limited range. The present result indicates that fabrication of composite coatings is a significant strategy to improve the corrosion resistance of Mg-Zn-Ca alloy and other alloys, thus enhancing the potential of using Mg alloys as bio-implants.

  5. Preparation and characterization of polymeric nanocomposite films for application as protective coatings

    Science.gov (United States)

    Gagliardi, S.; Rondino, F.; D'Erme, C.; Persia, F.; Menchini, F.; Santarelli, M. L.; Paulke, B.-R.; Enayati, A. L.; Falconieri, M.

    2017-08-01

    Addiction of ceramic nanoparticles to acrylic polymers provides a simple and effective means to produce paints with important properties, such as mechanical resistance and tailored wettability, even though for optimal performances, an engineered nanoparticle distribution would be desirable. In this paper we report on the realization and on the morphological and functional characterization of nanocomposites where the nanophase is distributed on the surface of acrylic polymer films, in order to enhance the expression of surface-related properties. To this aim, commercial titanium oxide and silicon oxide nanopowders were dispersed in water and the suspensions were air-sprayed on polymeric films prepared by paint brushing, thus producing a nanostructured ceramic surface coating. Control of the pH of suspensions and acrylic acid functionalization of the surface of titania were used together with high power ultrasonic treatments in order to control dimension of the aggregates in the sprayed suspensions. Optical microscopy, mechanical profilometry, and atomic force microscopy were used to characterize the nanocomposite surface morphology and correlate it to the coating functional properties, evaluated through mechanical abrasion tests and contact angle measurements; also, colorimetry on coated stones was performed in order to test the impact of the coatings on the aesthetical appearance and their photostability under UV irradiation. Results show that the nanostructured ceramic layer slightly improves the resistance of coatings to mechanical abrasion in case of polymer films prepared from latexes. The nanocomposite surface layer does not affect the wettability of the polymer, which remained slightly hydrophilic; this behavior is likely due to inadequate distribution of the nanophase. On the other hand UV-induced superhydrophilicity was observed when the concentration of surface titania nanoparticles is about 0.6 mg/cm2. Colorimetric analysis on historical and Carrara

  6. Effects of Surface Coating Preparation and Sliding Modes on Titanium Oxide Coated Titanium Alloy for Aerospace Applications

    Directory of Open Access Journals (Sweden)

    Bo Yuan Peng

    2014-01-01

    electrolytic oxidation (PEO. During the PEO procedure, a composition of silicate and phosphate was used as the electrolyte. In order to evaluate the coating, pin-on-disk (POD tribology tests and cyclic inclined sliding tests were used under dry room conditions. Furthermore, scanning electron microscopy (SEM and energy dispersive spectroscopy (EDS were utilized to examine the morphology and composition of the coating surfaces. The results of the POD tests revealed that the PEO coating could have a low coefficient of friction and suggested that high silicon concentrations in the PEO coatings take away oxygen from stoichiometric Ti oxides to create lubricating oxides. In addition, cyclic inclined sliding tests showed that smaller pores on the surface of the coating could permit a higher coating cohesive strength and allow the coated Ti alloy surface to perform better under high inclined sliding forces.

  7. Anticorrosion performance of chromized coating prepared by pack cementation in simulated solution with H2S and CO2

    Science.gov (United States)

    Wang, Qin-Ying; Behnamian, Yashar; Luo, Hong; Wang, Xian-Zong; Leitch, Michael; Zeng, Hongbo; Luo, Jing-Li

    2017-10-01

    A hash service environment containing H2S and CO2 in oil industry usually causes corrosion of carbon steel. In this study, the chromized coatings with different deposited time were prepared on the surface of carbon steel by the method of pack cementation to enhance its corrosion resistance. Then the microstructure, hardness, corrosion resistance as well as the semiconductor behavior of coatings in the simulated solution with saturated H2S and CO2 were investigated. The results show that the content of Cr in coating was increased by prolonging deposited time, and both chromium carbides and chromium nitrides were formed. Furthermore, coatings display higher polarization resistance, Rp, than that of the substrate, indicating a higher resistance to charge transfer on coating surface. The corrosion rates of coatings with different deposited time were significantly lower than that of substrate. Chemical analysis showed the formation of heavy sulfides on the surface of substrates after corrosion, while the least corrosion products were detected on the surface of coating with deposited time of 12 h. Mott-Schottky results indicated that coating of 12 h displayed less defects than the other two coatings with deposited time of 4 h and 8 h, which will be beneficial to improve corrosion resistance. The investigation showed that chromized coatings exhibited high corrosion resistance and owned a potential application in oil industry for corrosion prevention.

  8. Gastric transit and pharmacodynamics of a two-millimeter enteric-coated pancreatin microsphere preparation in patients with chronic pancreatitis

    NARCIS (Netherlands)

    Bruno, M. J.; Borm, J. J.; Hoek, F. J.; Delzenne, B.; Hofmann, A. F.; de Goeij, J. J.; van Royen, E. A.; van Leeuwen, D. J.; Tytgat, G. N.

    1998-01-01

    It has been suggested that enteric-coated pancreatin microsphere (ECPM) preparations with sphere sizes larger than 1.7 mm pass through the stomach at a slower rate than a meal and therefore may be less efficacious in restoring pancreatic enzyme activity than preparations with smaller sphere sizes.

  9. Preparation of an antibacterial, hydrophilic and photocatalytically active polyacrylic coating using TiO2nanoparticles sensitized by graphene oxide.

    Science.gov (United States)

    Nosrati, Rahimeh; Olad, Ali; Shakoori, Sahar

    2017-11-01

    In recent years more attentions have been paid for preparation of coatings with self-cleaning and antibacterial properties. These properties allow the surface to maintain clean and health over long times without any need to cleaning or disinfection. Acrylic coatings are widely used on various surfaces such as automotive, structural and furniture which their self-cleaning and antibacterial ability is very important. The aim of this work is the preparation of a polyacrylic based self-cleaning and antibacterial coating by the modification of TiO 2 as a coating additive. TiO 2 nanoparticles were sensitized to the visible light irradiation using graphene oxide through the preparation of TiO 2 /graphene oxide nanocomposite. Graphene oxide was prepared via a modified Hummers method. TiO 2 /graphene oxide nanocomposite was used as additive in a polyacrylic coating formulation. Hydrophilicity, photocatalytic and antibacterial activities as well as coating stability were evaluated for TiO 2 /graphene oxide modified polyacrylic coating and compared with that of pristine TiO 2 modified and unmodified polyacrylic coatings. TiO 2 /graphene oxide nanocomposite and polyacrylic coating modified by TiO 2 /graphene oxide additive were characterized using FT-IR, UV-Vis, XRD, and FESEM techniques. The effect of TiO 2 /graphene oxide composition and its percent in the coating formulation was evaluated on the polyacrylic coating properties. Results showed that polyacrylic coating having 3% W TiO 2 /graphene oxide nanocomposite additive with TiO 2 to graphene oxide ratio of 100:20 is the best coating considering most of beneficial features such as high photodecolorization efficiency of organic dye contaminants, high hydrophilicity, and stability in water. According to the results, TiO 2 is effectively sensitized by graphene oxide and the polyacrylic coating modified by TiO 2 /graphene oxide nanocomposite shows good photocatalytic activity under visible light irradiation. Copyright © 2017

  10. Preparation and evaluation of PEO-coated materials for a microchannel hemodialyzer.

    Science.gov (United States)

    Heintz, Keely; Schilke, Karl F; Snider, Joshua; Lee, Woo-Kul; Truong, Mitchell; Coblyn, Matthew; Jovanovic, Goran; McGuire, Joseph

    2014-07-01

    The marked increase in surface-to-volume ratio associated with microscale devices for hemodialysis leads to problems with hemocompatibility and blood flow distribution that are more challenging to manage than those encountered at the conventional scale. In this work stable surface modifications with pendant polyethylene oxide (PEO) chains were produced on polydimethylsiloxane (PDMS), polycarbonate microchannel, and polyacrylonitrile membrane materials used in construction of microchannel hemodialyzer test articles. PEO layers were prepared by radiolytic grafting of PEO-polybutadiene-PEO (PEO-PB-PEO) triblock polymers to the material surfaces. Protein repulsion was evaluated by measurement of surface-bound enzyme activity following contact of uncoated and PEO-coated surfaces with β-galactosidase. Protein adsorption was decreased on PEO-coated polycarbonate and PDMS materials to about 20% of the level recorded on the uncoated materials. Neither the triblocks nor the irradiation process was observed to have any effect on protein interaction with the polyacrylonitrile membrane, or its permeability to urea. This approach holds promise as a means for in situ application of safe, efficacious coatings to microfluidic devices for blood processing that will ensure good hemocompatibility and blood flow distribution, with no adverse effects on mass transfer. © 2013 Wiley Periodicals, Inc.

  11. Preparation of sintered silver nanosheets by coating technique using silver carbamate complex

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Hee-Yong; Cha, Jae-Ryung; Gong, Myoung-Seon, E-mail: msgong@dankook.ac.kr

    2015-03-01

    This study describes a coating technique approach for large-scale preparation of sintered silver nanosheets whose lateral dimensions were controlled in the thickness range of 50–65 nm. These procedures involved coating water-soluble poly (vinyl alcohol) (PVA) and silver 2-ethylhexylcarbamate (Ag-EHC), as well as thermal reduction of a silver precursor by heating at 150 °C, followed by dissolving away the PVA layer with alcoholic water. When the silver carbamate layer on the PVA layer was heated to 150 °C, the silver carbamate layer was thermally reduced and directed to grow into uniform sintered nanosheets with aspect ratios as high as 1000. The multi-stacked PVA/Ag structures and sintered silver nanosheets were confirmed by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. Measurements of the conductive property at room temperature indicated that these nanosheets were electrically continuous with a resistivity of approximately 7.3 × 10{sup −6} Ω cm. - Highlights: • A coating technique is used to make sintered Ag nanosheets. • PVA and silver carbamate act as a separation layer and a silver precursor. • The Ag nanosheets have thickness width 50–60 nm and width up to hundred μm. • The Ag nanosheets showed a resistivity of ca. 7.3 × 10{sup −6} Ω cm.

  12. Microstructure characterization of oxidation of aluminized coating prepared by a combined process

    Science.gov (United States)

    Liu, H. B.; Tao, J.; Xu, J.; Chen, Z. F.; Sun, X. J.; Xu, Z.

    2008-08-01

    Alumina layer is a good candidate for the tritium penetration barrier that is important in the control of tritium losses due to permeation through structural materials used in high-temperature gas-cooled reactors and in fusion reactors. This paper describes the microstructure of the oxide film of the tritium penetration barrier formed on 316L stainless steel, which was prepared by a combined process, namely, aluminizing and oxidizing treatments using a double glow plasma technology. Microstructure and phase structure of the coatings investigated were examined by scanning electronic microscope (SEM), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM), respectively. The chemical composition and the chemical states of Al, O elements in the oxidation film were identified by X-ray photoelectron spectroscopy (XPS). After aluminization, the typical microstructure of the coating mainly consisted of an outer high aluminum-containing intermetallic compound layer (Fe 2Al 5 and FeAl) and intermediate ferritic stainless steel (α Fe(Al))layer followed by the austenitic substrate. After the combined process, an oxide layer that consisted of Al 2O 3 and spinel FeAl 2O 4 had been successfully formed on the aluminizing coating surface, with an amorphous outmost surface and an underlying subsurface nanocrystalline structure.

  13. Assessment of osteoinduction using a porous hydroxyapatite coating prepared by micro-arc oxidation on a new titanium alloy.

    Science.gov (United States)

    Jing, Wensen; Zhang, Minghua; Jin, Lei; Zhao, Jian; Gao, Qing; Ren, Min; Fan, Qingyu

    2015-12-01

    Surface modification and material improvement is now an important way to improve the osseointegration between bone and uncemented prothesis. The purpose of this study was to investigate the bone ingrowth potential of porous hydroxyapatite (HA) coatings prepared by micro-arc oxidation (MAO) on Ti-3Zr-2Sn-3Mo-25Nb, a new titanium alloy. HA-coated specimens were implanted in the left proximal femoral medullary canal of beagles for 4, 12, and 24 weeks, and uncoated specimens were implanted in the right as a control. The surface morphology and phase composition were investigated with environmental scanning electron microscopy and X-ray diffractometry. The bone ingrowth was assessed by histomorphometry. A pull-out test was performed to assess the mechanical performance of the bone-implant interface. A porous coating was well prepared on the new titanium alloy by using the MAO method. The bone-to-implant contact was significantly higher for the HA-coated group compared to that in the uncoated group. Mechanical tests showed that the HA-coated group had significantly higher maximum force at the bone-implant interface compared to the uncoated specimens. MAO is a suitable coating approach for this new titanium alloy. The HA coating prepared by this approach can significantly promote bone ingrowth and the mechanical performance of the bone-implant interface. Copyright © 2015. Published by Elsevier Ltd.

  14. Nanocrystalline CdS thin films prepared by sol-gel spin coating

    Energy Technology Data Exchange (ETDEWEB)

    Thambidurai, M.; Muthukumarasamy, N.; Agilan, S.; Vasantha, S. [Coimbatore Institute of Technology (India). Dept. of Physics; Velauthapillai, Dhayalan [Univ. College of Bergen (Norway). Dept. of Engineering; Murugan, N. [Coimbatore Institute of Technology (India). Dept. of Mechanical Engineering; Balasundaraprabhu, R. [PSG College of Technology, Coimbatore (India). Dept. of Physics

    2011-05-15

    Nanocrystalline CdS thin films have been prepared using cadmium nitrate and thiourea as precursors using the solgel spin coating method. The structural studies carried out on the prepared films using X-ray diffraction and high resolution transmission electron microscopy revealed that the CdS films exhibit hexagonal structure and the grain size was observed to be 10 and 14 nm for the films annealed at 250 C and 450 C. The surface topography of the films was studied using atomic force microscopy and the roughness was found to be 32 nm. The optical absorbance studies showed a strong blue shift due to the quantum confinement effect present in the CdS films. The grain size calculated using the band gap energy and quantum confinement effect was found to be in agreement with the results obtained from structural studies. (orig.)

  15. Preparation and evaluation of graphene-coated solid-phase microextraction fiber

    Energy Technology Data Exchange (ETDEWEB)

    Chen Jinmei; Zou Jing; Zeng Jingbin; Song Xinhong; Ji Jiaojiao; Wang Yiru [Department of Chemistry and the Key Laboratory of Analytical Sciences of the Ministry of Education, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Ha, Jaeho [Food Analysis Center, Korea Food Research Institute, San 46-1, Baekhyun, Bundang, Seongnam, Gyonggi Province 463-746 (Korea, Republic of); Chen Xi, E-mail: xichen@xmu.edu.cn [Department of Chemistry and the Key Laboratory of Analytical Sciences of the Ministry of Education, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005 (China)

    2010-09-23

    In this paper, a novel graphene (G) based solid-phase microextraction (SPME) fiber was firstly prepared by immobilizing the synthesized G on stainless steel wire as coating. The new fiber possessed a homogeneous, porous and wrinkled surface and showed excellent thermal (over 330 {sup o}C), chemical and mechanical stability, and long lifespan (over 250 extractions). The SPME performance of the G-coated fiber was evaluated in detail through extraction of six pyrethroid pesticides. Although the thickness of G-coated fiber was only 6-8 {mu}m, its extraction efficiencies were higher than those of two commercial fibers (PDMS, 100 {mu}m; PDMS/DVB, 65 {mu}m). This high extraction efficiency may be mainly attributed to huge delocalized {pi}-electron system of G, which shows strong {pi}-stacking interaction with pyrethroid pesticide. The G-coated fiber was applied in the gas chromatographic determination of six pyrethroids, and their limits of detection were found to be ranged from 3.69 to 69.4 ng L{sup -1}. The reproducibility for each single fiber was evaluated and the relative standard deviations (RSDs) were calculated to be in the range from 1.9% to 6.5%. The repeatability of fiber-to-fiber and batch-to-batch was 4.3-9.2% and 4.1-9.9%. The method developed was successfully applied to three pond water samples, and the recoveries were 83-110% at a spiking of 1 {mu}g L{sup -1}.

  16. Chitosan-pectin hybrid nanoparticles prepared by coating and blending techniques.

    Science.gov (United States)

    Rampino, A; Borgogna, M; Bellich, B; Blasi, P; Virgilio, F; Cesàro, A

    2016-03-10

    The preparation of chitosan nanoparticles in combination with pectins, as additional mucoadhesive biopolymers, was investigated. Pectins from apple and from citrus fruit were considered; polygalacturonic acid was taken as a reference. Tripolyphosphate was used as an anionic cross-linker. Two different techniques were compared, namely the coating and the blending. Coated nanoparticles (NPs) in the ratio pectin:NPs from 2:1 to 5:1 evidenced that the size of NPs increased as the amount of pectin (both from apple and citrus fruit) was increased. In particular, for NPs coated with pectin from citrus fruit the size ranges from 200 to 260nm; while for NPs coated with pectin from apple the size ranges from 330 to 450nm. A minimum value of Z-potential around -35mV was obtained for the ratio pectin:NPs 4:1, while further addition of pectin did not decrease the Z-potential. Also blended NPs showed a dependence of the size on the ratio of the components: for a given ratio pectin:tripolyphosphate the size increases as the fraction of chitosan increases; for a low ratio chitosan:pectin a high amount of tripolyphosphate was needed to obtain a compact structure. The effect of the additional presence of loaded proteins in chitosan-pectin nanoparticles was also investigated, since proteins contribute to alter the electrostatic interactions among charged species. FT-IR and DSC characterization are presented to confirm the interactions between biopolymers. Finally, the biocompatibility of the used materials was assessed by the chorioallantoic membrane assay, confirming the safety of the materials. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Novel antibacterial silver-silica surface coatings prepared by chemical vapour deposition for infection control.

    Science.gov (United States)

    Varghese, S; Elfakhri, S; Sheel, D W; Sheel, P; Bolton, F J; Foster, H A

    2013-11-01

    Environmental contamination plays an important role in the transmission of infections, especially healthcare-associated infections. Disinfection transiently reduces contamination, but surfaces can rapidly become re-contaminated. Antimicrobial surfaces may partially overcome that limitation. The antimicrobial activity of novel surface coatings containing silver and silica prepared using a flame-assisted chemical vapour deposition method on both glass and ceramic tiles was investigated. Antimicrobial activity against a variety of bacteria including recent clinical isolates was investigated based on the BS ISO 22196:2007 Plastics--Measurement of antibacterial activity on plastics surfaces, British Standards Institute, London, method. Activity on natural contamination in an in use test in a toilet facility was also determined. Activity on standard test strains gave a log10 reduction of five after 1-4 h. The hospital isolates were more resistant, but MRSA was reduced by a log10 reduction factor of >5 after 24 h. Activity was maintained after simulated ageing and washing cycles. Contamination in situ was reduced by >99.9% after 4 months. Activity was inhibited by protein, but, although this could be overcome by increasing the amount of silver in the films, this reduced the hardness of the coating. The coatings had a good activity against standard test strains. Clinical isolates were killed more slowly but were still sensitive. The optimum composition for use therefore needs to be a balance between activity and durability. The coatings may have applications in health care by maintaining a background antimicrobial activity between standard cleaning and disinfection regimes. They may also have applications in other areas where reduction in microbial contamination is important, for example, in the food industry. © 2013 The Society for Applied Microbiology.

  18. Preparation and characterization of chondroitin‐sulfate‐A‐coated magnetite nanoparticles for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Tóth, Ildikó Y., E-mail: Ildiko.Toth@chem.u-szeged.hu; Illés, Erzsébet; Szekeres, Márta; Tombácz, Etelka, E-mail: tombacz@chem.u-szeged.hu

    2015-04-15

    Polysaccharides are promising candidates for manufacturing biocompatible core–shell nanoparticles with potential in vivo use. Superparamagnetic magnetite nanoparticles (MNPs) have prospective application in both diagnosis and therapy, and so developing a novel polysaccharide shell on MNP core is of great challenge. MNPs were prepared by co-precipitation, then the surface of purified MNPs was coated with chondroitin-sulfate-A (CSA) to obtain core–shell structured magnetite nanoparticles (CSA@MNP). The effect of the added amount of CSA on the surface charging and the aggregation state of MNPs at various pHs and 10 mM NaCl was measured by electrophoresis and dynamic light scattering. The amphoteric behavior of MNPs was fundamentally modified by adsorption of CSA polyanions. A very low CSA-loading induces the aggregation of MNPs, while four times more stabilizes the dispersions over the whole pH-range studied. The coagulation kinetics experiments measured at pH=6.3±0.3 showed that salt tolerance of CSA@MNPs rises up to ~150 mM NaCl. - Highlights: • Novel CSA-coated core–shell magnetite nanoparticles were prepared successfully. • The aggregation range of MNPs was shifted gradually to the lower pHs by CSA-loading. • CSA stabilizes electrosterically the MNPs over wide pH-range relevant to biosystems. • The salt tolerance of CSA@MNP enables them to use under physiological condition.

  19. Effect of Suspension Plasma-Sprayed YSZ Columnar Microstructure and Bond Coat Surface Preparation on Thermal Barrier Coating Properties

    Science.gov (United States)

    Bernard, Benjamin; Quet, Aurélie; Bianchi, Luc; Schick, Vincent; Joulia, Aurélien; Malié, André; Rémy, Benjamin

    2017-08-01

    Suspension plasma spraying (SPS) is identified as promising for the enhancement of thermal barrier coating (TBC) systems used in gas turbines. Particularly, the emerging columnar microstructure enabled by the SPS process is likely to bring about an interesting TBC lifetime. At the same time, the SPS process opens the way to a decrease in thermal conductivity, one of the main issues for the next generation of gas turbines, compared to the state-of-the-art deposition technique, so-called electron beam physical vapor deposition (EB-PVD). In this paper, yttria-stabilized zirconia (YSZ) coatings presenting columnar structures, performed using both SPS and EB-PVD processes, were studied. Depending on the columnar microstructure readily adaptable in the SPS process, low thermal conductivities can be obtained. At 1100 °C, a decrease from 1.3 W m-1 K-1 for EB-PVD YSZ coatings to about 0.7 W m-1 K-1 for SPS coatings was shown. The higher content of porosity in the case of SPS coatings increases the thermal resistance through the thickness and decreases thermal conductivity. The lifetime of SPS YSZ coatings was studied by isothermal cyclic tests, showing equivalent or even higher performances compared to EB-PVD ones. Tests were performed using classical bond coats used for EB-PVD TBC coatings. Thermal cyclic fatigue performance of the best SPS coating reached 1000 cycles to failure on AM1 substrates with a β-(Ni,Pt)Al bond coat. Tests were also performed on AM1 substrates with a Pt-diffused γ-Ni/γ'-Ni3Al bond coat for which more than 2000 cycles to failure were observed for columnar SPS YSZ coatings. The high thermal compliance offered by both the columnar structure and the porosity allowed the reaching of a high lifetime, promising for a TBC application.

  20. Calcium phosphate/porous silicon biocomposites prepared by cyclic deposition methods: Spin coating vs electrochemical activation

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Montelongo, J., E-mail: jacobo.hernandez@uam.es [Departamento de Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Gallach, D.; Naveas, N.; Torres-Costa, V. [Departamento de Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Climent-Font, A. [Departamento de Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Centro de Microanálisis de Materiales (CMAM), Universidad Autónoma de Madrid, Madrid 28049 (Spain); García-Ruiz, J.P. [Departamento de Biología Molecular, Universidad Autónoma de Madrid, Cantoblanco, Madrid 28049 (Spain); Manso-Silvan, M. [Departamento de Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid (Spain)

    2014-01-01

    Porous silicon (PSi) provides an excellent platform for bioengineering applications due to its biocompatibility, biodegradability, and bioresorbability. However, to promote its application as bone engineering scaffold, deposition of calcium phosphate (CaP) ceramics in its hydroxyapatite (HAP) phase is in progress. In that sense, this work focuses on the synthesis of CaP/PSi composites by means of two different techniques for CaP deposition on PSi: Cyclic Spin Coating (CSC) and Cyclic Electrochemical Activation (CEA). Both techniques CSC and CEA consisted on alternate Ca and P deposition steps on PSi. Each technique produced specific morphologies and CaP phases using the same independent Ca and P stem-solutions at neutral pH and at room temperature. The brushite (BRU) phase was favored with the CSC technique and the hydroxyapatite (HAP) phase was better synthesized using the CEA technique. Analyses by elastic backscattering spectroscopy (EBS) on CaP/PSi structures synthesized by CEA supported that, by controlling the CEA parameters, an HAP coating with the required Ca/P atomic ratio of 1.67 can be promoted. Biocompatibility was evaluated by bone-derived progenitor cells, which grew onto CaP/PSi prepared by CSC technique with a long-shaped actin cytoskeleton. The density of adhered cells was higher on CaP/PSi prepared by CEA, where cells presented a normal morphological appearance and active mitosis. These results can be used for the design and optimization of CaP/PSi composites with enhanced biocompatibility for bone-tissue engineering. - Highlights: • Proposed cyclic methods produce specific morphologies and CaP phases in biocomposites. • The brushite phase is favored in the biocomposite produced by Cyclic Spin Coating. • The hydroxyapatite phase is favored in the biocomposite produced by Cyclic Electrochemical Activation. • The Ca/P atomic ratio of hydroxyapatite was validated by elastic backscattering spectroscopy. • Cells grown showed morphological and

  1. Preparation of H2SO4 doped Polyaniline thin film solar cells by spin coating technique

    Science.gov (United States)

    Patel, Abhishek; Pataniya, Pratik; Patel, K. D.; Solanki, G. K.; Pathak, V. M.

    2017-05-01

    A water diluted H2SO4 solution was used to dissolve Polyaniline in order to obtain a solution for preparation of thin films by spin coating technique. The chemical bonding characteristics of the prepared films were investigated using Furrier transform infrared spectroscopy (FTIR) and the structural characterizations were accomplished by X-ray diffraction (XRD). UV-VIS absorption spectroscopy was used to determine the optical band gap of the deposited PANi films and the indirect optical band gap of PANi was estimated to be in the range of 1.3 to 1.8 eV from the Tauc's plot. Further, these films were deposited on the n-MoSe2 crystal in order to complete a solar cell structure. The polychromatic photo response of the prepared solar cells for different intensities was studied at room temperature and the efficiency and fill factor were found to be 1% and 0.26 respectively. The obtained Photo-conversion characteristics (I-V) were also used to determined series and shunt resistances of the prepared device. The series resistance was found to be around 33.3 kΩ which is quite high. This may be a reason for such a low efficiency of this cell.

  2. Preparation of N,O-carboxymethyl chitosan coated alginate microcapsules and their application to Bifidobacterium longum BIOMA 5920

    Energy Technology Data Exchange (ETDEWEB)

    Mi, Yu; Su, Ran [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University (China); Fan, Dai-Di, E-mail: fandaidi@nwu.edu.cn [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University (China); Zhu, Xiao-Li [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Urban and Environmental Science, Northwest University, Taibai North Road 229, Xi' an, Shaanxi 710069 (China); Zhang, Wen-Ni [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University (China); Shaanxi Key Laboratory of Degradable Biomedical Materials, School of Chemical Engineering, Northwest University (China)

    2013-07-01

    In order to greatly improve vitality of probiotic bacteria within the application, a novel biocompatible vehicle, N,O-carboxymethyl chitosan (NOCs) with appropriate degrees of substitution coat alginate (ALg) microparticles, was prepared by electrostatic droplet generation. The amount of chitosan (Cs) and N,O-carboxymethyl chitosan (NOCs) coated on the ALg microparticles was determined by differential scanning calorimetry. The surface morphology of ALg microparticles, Cs coated ALg microparticles and NOCs coated ALg microparticles was determined using scanning electron microscopy. The coating thickness of Cs coated ALg microparticles and that of NOCs coated ALg microparticles was directly observed with confocal laser scanning microscopy. In order to assess pH sensitivity of microparticles, the bovine serum albumin release from the microspheres was tested in acid solution (pH 2.0) for 2 h and subsequently in alkaline solution (pH 7.0) for 2 h. The survival of Bifidobacterium longum BIOMA 5920 loaded in NOCs coated with ALg microparticle was improved in simulated gastric juice (pH 2.0, for 2 h) compared to that of B. longum BIOMA 5920 loaded in ALg microparticles and Cs coated ALg microparticles. After incubation in simulated intestinal juices (pH 7.0, 2 h), the release of microencapsulated B. longum BIOMA 5920 was investigated. - Highlights: • Synthesised N,O-carboxymethyl chitosan (NOCs) coated alginate (ALg) microspheres. • Their effect on intestinal microflora was investigated in simulated gastric juices. • NOCs A coated ALg microspheres improved Bifidobacterium longum survival in SGJ. • The modified chitosan layer improved the pH-response of alginate microspheres. • NOCs A coated microspheres could be used to deliver oral bioactive compounds.

  3. Preparation of silicon-substituted hydroxyapatite coatings on Ti–30Nb–xTa alloys using cyclic electrochemical deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Sil [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University (Korea, Republic of); Jeong, Yong-Hoon [Biomechanics and Tissue Engineering Laboratory, Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University (Korea, Republic of); Brantley, William A. [Division of Restorative Science and Prosthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States)

    2014-12-01

    Silicon-substituted hydroxyapatite coatings on Ti–30Nb–xTa alloys, prepared using a cyclic electrochemical deposition method, have been investigated using a variety of surface analytical experimental methods. The silicon-substituted hydroxyapatite (Si-HA) coatings were prepared by electrolytic deposition in electrolytes containing Ca{sup 2+}, PO{sub 4}{sup 3−} and SiO{sub 3}{sup 2−} ions. The deposited layers were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and a wettability test. Phase transformation from (α″ + β) to largely β occurred with increasing Ta content in the Ti –30Nb–xTa alloys, yielding larger grain size. The morphology of the Si-HA coatings was changed by increasing the number of deposition cycles, with the initial plate-like structures changing to mixed rod-like and plate-like shapes, and finally to a rod-like structure. From the ATR-FTIR spectra, Si existed in the form of SiO{sub 4}{sup 4−} groups in Si-HA coating layer. The lowest aqueous contact angles and best wettability were found for the Si-HA coatings prepared with 30 deposition cycles. - Highlights: • Electrochemically deposited Si-HA coatings on Ti –30Nb–xTa alloys were investigated. • The Si-HA coatings were initially precipitated along the martensitic structure. • The morphology of the Si-HA coating changed with the deposition cycles. • Si existed in the form of SiO{sub 4}{sup 4−} groups in the Si-HA coating.

  4. Optical Constants of Crystallized TiO2 Coatings Prepared by Sol-Gel Process

    National Research Council Canada - National Science Library

    Xiaodong Wang; Guangming Wu; Bin Zhou; Jun Shen

    2013-01-01

      Titanium oxide coatings have been deposited by the sol-gel dip-coating method. Crystallization of titanium oxide coatings was then achieved through thermal annealing at temperatures above 400 °C...

  5. Preparation of pellets containing highly soluble drug by extrusion/spheronisation and coating with Kollicoat® SR 30D

    OpenAIRE

    Andreazza,Itamar Francisco; Ferraz,Humberto Gomes

    2011-01-01

    The aim of this study was to prepare and evaluate the pellets, containing a highly soluble drug (ascorbic acid), by the extrusion-spheronization process and coated with a release controlling polymer. The coating (undertaken in a fluid bed) was applied to three batches of the pellets with a dispersion of Kollicoat® SR 30 D, with each batch of pellets receiving a different level of polymer (5.07; 8.26 and 10.35%). The coated pellets were evaluated for sphericity by imaging analysis and comparat...

  6. Mechanical and Anticorrosive Properties of Graphene/Epoxy Resin Composites Coating Prepared by in-Situ Method

    OpenAIRE

    Zhiyi Zhang; Wenhui Zhang; Diansen Li; Youyi Sun; Zhuo Wang; Chunling Hou; Lu Chen; Yang Cao; Yaqing Liu

    2015-01-01

    The graphene nanosheets-based epoxy resin coating (0, 0.1, 0.4 and 0.7 wt %) was prepared by a situ-synthesis method. The effect of polyvinylpyrrolidone/reduced graphene oxide (PVP-rGO) on mechanical and thermal properties of epoxy resin coating was investigated using nanoindentation technique and thermogravimetric analysis, respectively. A significant enhancement (ca. 213% and 73 °C) in the Young modulus and thermal stability of epoxy resin coating was obtained at a loading of 0.7 wt %, re...

  7. Preparation and self-sterilizing properties of Ag@TiO{sub 2}–styrene–acrylic complex coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiang-dong; Chen, Feng; Yang, Jin-tao, E-mail: yangjt@zjut.edu.cn; Yan, Xiao-hui; Zhong, Ming-qiang, E-mail: zhongmingqiang@hotmail.com

    2013-04-01

    In this study, we report a simple and cost-effective method for self-sterilized complex coatings obtained by Ag@TiO{sub 2} particle incorporation into styrene–acrylic latex. The Ag@TiO{sub 2} particles were prepared via a coupling agent modification process. The composite latices characterized by transmission electron microscopy (TEM) study were highly homogeneous at the nanometric scale, and the Ag@TiO{sub 2} particles were well dispersed and exhibited an intimate contact between both the organic and inorganic components. The Ag@TiO{sub 2} nanoparticles significantly enhanced the absorption in the visible region and engendered a good heat-insulating effect of the complex coatings. Moreover, the Ag@TiO{sub 2} nanoparticle incorporation into this polymer matrix renders self-sterilized nanocomposite materials upon light excitation, which are tested against Escherichia coli and Staphylococcus aureus. The complex coatings display an impressive performance in the killing of all micro-organisms with a maximum for a Ag@TiO{sub 2} loading concentration of 2–5 wt.%. The weathering endurance of the complex coating was also measured. - Highlights: ► We prepared Ag@TiO{sub 2}–styrene–acrylic complex latex in one pot. ► Good antibacterial performances of complex coatings were observed. ► The complex coating was resistant to weathering after 48 h. ► The complex coating exhibits good heat-insulating effect.

  8. Chitosan-Based Coating with Antimicrobial Agents: Preparation, Property, Mechanism, and Application Effectiveness on Fruits and Vegetables

    Directory of Open Access Journals (Sweden)

    Yage Xing

    2016-01-01

    Full Text Available Chitosan coating is beneficial to maintaining the storage quality and prolonging the shelf life of postharvest fruits and vegetables, which is always used as the carrier film for the antimicrobial agents. This review focuses on the preparation, property, mechanism, and application effectiveness on the fruits and vegetables of chitosan-based coating with antimicrobial agents. Chitosan, derived by deacetylation of chitin, is a modified and natural biopolymer as the coating material. In this article, the safety and biocompatible and antimicrobial properties of chitosan were introduced because these attributes are very important for its application. The methods to prepare the chitosan-based coating with antimicrobial agents, such as essential oils, acid, and nanoparticles, were developed by other researchers. Meanwhile, the application of chitosan-based coating is mainly due to its antimicrobial activity and other functional properties, which were investigated, introduced, and analyzed in this review. Furthermore, the surface and mechanical properties were also investigated by researchers and concluded in this article. Finally, the effects of chitosan-based coating on the storage quality, microbial safety, and shelf life of fruits and vegetables were introduced. Their results indicated that chitosan-based coating with different antimicrobial agents would probably have wide prospect in the preservation of fruits and vegetables in the future.

  9. Properties and Cutting Performance of TiAlSiN Coating Prepared by Cathode Arc Ion Plating

    Science.gov (United States)

    Zhang, Er-Geng; Chen, Qiang; Wang, Qin-Xue; Huang, Biao

    2016-06-01

    TiAlSiN coating was deposited on high-speed steel (HSS) samples and cemented carbide tool inserts, respectively, by a new coating preparation procedure, and its properties and cutting performance were characterized. The coating thickness, chemical composition, microstructure morphology and mechanical properties were investigated by X-ray fluorescence measurement system, energy dispersive spectrometer (EDS), scanning electron microscope (SEM), nanoindentation, Rockwell hardness tester and ball-on-disc tribometer. A 3D orthogonal cutting experiment model was established by DEFORM-3D to study the influences of different coating thicknesses on cutting force and temperature, and the field cutting experiment was carried out. The results show that the thickness of TiAlSiN coating is 3.14μm prepared by the 3μm preparation procedure, microhardness is 36.727GPa with the Si content of about 5.22at.% as well as good fracture toughness and adhesion strength. The TC4 and AISI 1045 cutting tool inserts with 4μm coating thickness have the minimum cutting forces of about 734.7N and 450.7N, respectively. Besides, tool inserts with a thickness of 3μm have the minimum cutting temperatures of about 510.2∘C and 230.6∘C, respectively.

  10. Nanoemulsions coated with alginate/chitosan as oral insulin delivery systems: preparation, characterization, and hypoglycemic effect in rats.

    Science.gov (United States)

    Li, Xiaoyang; Qi, Jianping; Xie, Yunchang; Zhang, Xi; Hu, Shunwen; Xu, Ying; Lu, Yi; Wu, Wei

    2013-01-01

    This study aimed to prepare nanoemulsions coated with alginate/chitosan for oral insulin delivery. Uncoated nanoemulsions were prepared by homogenization of a water in oil in water (w/o/w) multiple emulsion that was composed of Labrafac(®) CC, phospholipid, Span™ 80 and Cremorphor(®) EL. Coating of the nanoemulsions was achieved based on polyelectrolyte cross-linking, with sequential addition of calcium chloride and chitosan to the bulk nanoemulsion dispersion that contained alginate. The particle size of the coated nanoemulsions was about 488 nm and the insulin entrapment ratio was 47.3%. Circular dichroism spectroscopy proved conformational stability of insulin against the preparative stress. In vitro leakage study indicated well-preserved integrity of the nanoemulsions in simulated gastric juices. Hypoglycemic effects were observed in both normal and diabetic rats. The relative pharmacological bioavailability of the coated nanoemulsion with 25 and 50 IU/kg insulin were 8.42% and 5.72% in normal rats and 8.19% and 7.84% in diabetic rats, respectively. Moreover, there were significantly prolonged hypoglycemic effects after oral administration of the coated nanoemulsions compared with subcutaneous (sc) insulin. In conclusion, the nanoemulsion coated with alginate/chitosan was a potential delivery system for oral delivery of polypeptides and proteins.

  11. Influence of silane on the structure of polystyrene prepared by sol-gel coatings via UV curing

    Science.gov (United States)

    Balbay, Senay; Acıkgoz, Caglayan

    2017-11-01

    Light, heat, oxygen, moisture, ozone, atmospheric pollution and biological effects are the most important effectives wreak to chemical degradation in the polymer structure. In result of chemical degradation on the polymer consist of problems such as discoloration, brittleness, surface cracks, perspiration, crumbling, smell, surface acidity. In this work, it is aimed to improve the problem of the polystyrene (PS) material against chemical degradation. For this reason, PS is coated with silica sol-gel hybrid coating. Silica sol-gel was synthesized by using vinyltrimethoxysilane (VTMS) as a cross-linker and tetraethylorthosilicate (TEOS) as a silica source. Firstly, four different pre-treatment technique (oven, vacuum oven, lyophilizer and freezing) was studied to determine the most suitable pre-treatment technique for coating on PS substrate of sol-gel prepared with initial formulation (S1). A freezing technique gave the best results for coating sample. The change of surface colour of coated PS was measured by CIE L*a*b* methods. Secondly, the most suitable curing agent (Irgacure 184, Irgacure 819, Darocur 1173 and TiO2 as crystalline anatase phase) was determined to coat the sol-gel on PS. It was determined to the lowest yellowing of PS surface hybrid coated as UV curing of TEOS sol modified by VTMS and TiO2 as photo-initiators. Finally, the chemical and morphological structure of the coated PS samples was determined by FT-IR and SEM instruments, respectively.

  12. Influence of silane on the structure of polystyrene prepared by sol-gel coatings via UV curing

    Directory of Open Access Journals (Sweden)

    Balbay Senay

    2017-01-01

    Full Text Available Light, heat, oxygen, moisture, ozone, atmospheric pollution and biological effects are the most important effectives wreak to chemical degradation in the polymer structure. In result of chemical degradation on the polymer consist of problems such as discoloration, brittleness, surface cracks, perspiration, crumbling, smell, surface acidity. In this work, it is aimed to improve the problem of the polystyrene (PS material against chemical degradation. For this reason, PS is coated with silica sol-gel hybrid coating. Silica sol-gel was synthesized by using vinyltrimethoxysilane (VTMS as a cross-linker and tetraethylorthosilicate (TEOS as a silica source. Firstly, four different pre-treatment technique (oven, vacuum oven, lyophilizer and freezing was studied to determine the most suitable pre-treatment technique for coating on PS substrate of sol-gel prepared with initial formulation (S1. A freezing technique gave the best results for coating sample. The change of surface colour of coated PS was measured by CIE L*a*b* methods. Secondly, the most suitable curing agent (Irgacure 184, Irgacure 819, Darocur 1173 and TiO2 as crystalline anatase phase was determined to coat the sol-gel on PS. It was determined to the lowest yellowing of PS surface hybrid coated as UV curing of TEOS sol modified by VTMS and TiO2 as photo-initiators. Finally, the chemical and morphological structure of the coated PS samples was determined by FT-IR and SEM instruments, respectively.

  13. Coatings of Different Carbon Nanotubes on Platinum Electrodes for Neuronal Devices: Preparation, Cytocompatibility and Interaction with Spiral Ganglion Cells.

    Directory of Open Access Journals (Sweden)

    Niklas Burblies

    Full Text Available Cochlear and deep brain implants are prominent examples for neuronal prostheses with clinical relevance. Current research focuses on the improvement of the long-term functionality and the size reduction of neural interface electrodes. A promising approach is the application of carbon nanotubes (CNTs, either as pure electrodes but especially as coating material for electrodes. The interaction of CNTs with neuronal cells has shown promising results in various studies, but these appear to depend on the specific type of neurons as well as on the kind of nanotubes. To evaluate a potential application of carbon nanotube coatings for cochlear electrodes, it is necessary to investigate the cytocompatibility of carbon nanotube coatings on platinum for the specific type of neuron in the inner ear, namely spiral ganglion neurons. In this study we have combined the chemical processing of as-delivered CNTs, the fabrication of coatings on platinum, and the characterization of the electrical properties of the coatings as well as a general cytocompatibility testing and the first cell culture investigations of CNTs with spiral ganglion neurons. By applying a modification process to three different as-received CNTs via a reflux treatment with nitric acid, long-term stable aqueous CNT dispersions free of dispersing agents were obtained. These were used to coat platinum substrates by an automated spray-coating process. These coatings enhance the electrical properties of platinum electrodes, decreasing the impedance values and raising the capacitances. Cell culture investigations of the different CNT coatings on platinum with NIH3T3 fibroblasts attest an overall good cytocompatibility of these coatings. For spiral ganglion neurons, this can also be observed but a desired positive effect of the CNTs on the neurons is absent. Furthermore, we found that the well-established DAPI staining assay does not function on the coatings prepared from single-wall nanotubes.

  14. Comparative bioavailability of two enteric-coated tablet preparations of diclofenac sodium.

    Science.gov (United States)

    Paton, D M

    1987-01-01

    In a random cross-over study, eight healthy volunteers received single 25 mg doses of enteric-coated diclofenac sodium tablets (as either Voltaren 25, Ciba-Geigy or Anfenax 25, Istituto Biochimico Italiano) after an overnight fast. The bioavailability of these two preparations of diclofenac sodium did not differ significantly as judged by absorption lag time, peak plasma concentration, time to peak plasma concentrations or area under the plasma concentration-time curve. Diclofenac was found to have a plasma clearance of 2.85 +/- 1.03 (s.d.) and 3.39 +/- 1.43 ml min-1 kg-1, a plasma terminal half-life of elimination of 0.61 +/- 0.25 and 0.71 +/- 0.39 h, and an apparent volume of distribution of 0.15 +/- 0.10 and 0.21 +/- 0.13 l kg-1 (the values obtained with the Ciba-Geigy preparation being shown before the Istituto Biochimico Italiano preparation in each case).

  15. Preparation and characterization of underwater superoleophobic chitosan/poly(vinyl alcohol) coatings for self-cleaning and oil/water separation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qian; Fu, Youjia; Yan, Xiaoxia; Chang, Yanjiao; Ren, Lili; Zhou, Jiang

    2017-08-01

    Highlights: • Underwater superoleophobic CS/PVA coatings were prepared using a facile method. • Immersion in NaOH solution was crucial to enhance roughness of the coating surface. • Effects of coating composition on wettability of coating surface were investigated. • The CS/PVA coatings possess self-cleaning property. • The CS/PVA coatings can be used for oil/water separation with high efficiency. - Abstract: In this paper, chitosan (CS)/poly(vinyl alcohol) (PVA) coatings cross-linked with glutaraldehyde (GA) were prepared. Effects of the coating composition and NaOH solution treatment on surface morphology and topography were investigated by scanning electron microscope and atomic force microscope. It was found that the process of immersing the CS/PVA coatings into NaOH solution was crucial to enhance rough structure on the coating surface. The rough surface structure and the hydrophilic groups of CS and PVA made the CS/PVA coatings possess underwater superoleophobicity and low adhesion to oil. Oil contact angle of the prepared CS/PVA coatings was up to 161° and slide angle was only 3°. Moreover, the CS/PVA coatings showed stable superoleophobicity in high salt, strong acidic, and alkaline environments as well as underwater self-cleaning property and excellent transparency. The CS/PVA coatings could be used for gravity driven oil/water separation with high efficiency.

  16. Preparation and in vitro Evaluation of Ethylcellulose Coated Egg Albumin Microspheres of Diltiazem Hydrochloride.

    Science.gov (United States)

    Shailesh, Tp; Vipul, Pd; Girishbhai, Jk; Manish, Cj

    2010-01-01

    The aim of the present investigation was to develop sustained release ethylcellulose-coated egg albumin microspheres of diltiazem hydrochloride (DH) to improve patient compliance. The microspheres were prepared by the w/o emulsion thermal cross-linking method using different proportion of the polymer to drug ratio (1.0:1.0, 1.0:1.5 and 1.0:2.0). A 3(2) full factorial design was employed to optimize two independent variables, polymer to drug ratio (X(1)) and surfactant concentration (X(2)) on dependent variables, namely % drug loading, % drug release in 60 min (Y(60)) and the time required for 80 % drug release (t(80)) were selected as dependable variable. Optimized formulation was compared to its sustained release tablet available in market. The polymer to drug ratio was optimized to 1:1 at which a high drug entrapment efficiency 79.20% ± 0.7% and the geometric mean diameter 47.30 ± 1.5 mm were found. All batches showed a biphasic release pattern; initial burst release effect (55% DH in 1 h) and then were released completely within 6 h. In situ coating of optimized egg albumin DH microspheres using 7.5% ethylcellulose significantly reduced the burst effect and provided a slow release of DH for 8-10 h. Finally, it was concluded that ethylcellulose-coated egg albumin DH microspheres is suitable for oral SR devices in the treatment of angina pectoris, cardiac arrhythmias, and hypertension due to their size and release profile.

  17. Preparation and Characterization of Silica-Coated Magnetic–Fluorescent Bifunctional Microspheres

    Directory of Open Access Journals (Sweden)

    Xiao Qi

    2009-01-01

    Full Text Available Abstract Bifunctional magnetic–fluorescent composite nanoparticles (MPQDs with Fe3O4MPs and Mn:ZnS/ZnS core–shell quantum dots (QDs encapsulated in silica spheres were synthesized through reverse microemulsion method and characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, vibration sample magnetometer, and photoluminescence (PL spectra. Our strategy could offer the following features: (1 the formation of Mn:ZnS/ZnS core/shell QDs resulted in enhancement of the PL intensity with respect to that of bare Mn:ZnS nanocrystals due to the effective elimination of the surface defects; (2 the magnetic nanoparticles were coated with silica, in order to reduce any detrimental effects on the QD PL by the magnetic cores; and (3 both Fe3O4MPs and Mn:ZnS/ZnS core–shell QDs were encapsulated in silica spheres, and the obtained MPQDs became water soluble. The experimental conditions for the silica coating on the surface of Fe3O4nanoparticles, such as the ratio of water to surfactant (R, the amount of ammonia, and the amount of tetraethoxysilane, on the photoluminescence properties of MPQDs were studied. It was found that the silica coating on the surface of Fe3O4could effectively suppress the interaction between the Fe3O4and the QDs under the most optimal parameters, and the emission intensity of MPQDs showed a maximum. The bifunctional MPQDs prepared under the most optimal parameters have a typical diameter of 35 nm and a saturation magnetization of 4.35 emu/g at room temperature and exhibit strong photoluminescence intensity.

  18. Neutral hydrophilic coatings for capillary electrophoresis prepared by controlled radical polymerization.

    Science.gov (United States)

    Navarro, Fabián H; Gómez, Jorge E; Espinal, José H; Sandoval, Junior E

    2016-12-15

    In the present study, porous silica particles as well as impervious fused-silica wafers and capillary tubes were modified with hydrophilic polymers (hydroxylated polyacrylamides and polyacrylates), using a surface-confined grafting procedure based on atom transfer radical polymerization (ATRP) which was also surface-initiated from α-bromoisobutyryl groups. Initiator immobilization was achieved by hydrosilylation of allyl alcohol on hydride silica followed by esterification of the resulting propanol-bonded surface with α-bromoisobutyryl bromide. Elemental analysis, IR and NMR spectroscopies on silica micro-particles, atomic force microscopy, ellipsometry and profilometry on fused-silica wafers, as well as CE on fused-silica tubes were used to characterize the chemically modified silica substrate at different stages. We studied the effect of monomer concentration as well as cross-linker on the ability of the polymer film to reduce electroosmosis and to prevent protein adsorption (i. e., its non-fouling capabilities) and found that the former was rather insensitive to both parameters. Surface deactivation towards adsorption was somewhat more susceptible to monomer concentration and appeared also to be favored by a low concentration of the cross-linker. The results show that hydrophilic polyacrylamide and polyacrylate coatings of controlled thickness can be prepared by ATRP under very mild polymerization conditions (aqueous solvent, room temperature and short reaction times) and that the coated capillary tubes exhibit high efficiencies for protein separations (0.3-0.6 million theoretical plates per meter) as well as long-term hydrolytic stability under the inherently harsh conditions of capillary isoelectric focusing. Additionally, there was no adsorption of lysozyme on the coated surface as indicated by a complete recovery of the basic enzyme. Furthermore, since polymerization is confined to the inner capillary surface, simple precautions (e.g., solution filtration

  19. Preparation of silica coated cobalt ferrite magnetic nanoparticles for the purification of histidine-tagged proteins

    Science.gov (United States)

    Aygar, Gülfem; Kaya, Murat; Özkan, Necati; Kocabıyık, Semra; Volkan, Mürvet

    2015-12-01

    Surface modified cobalt ferrite (CoFe2O4) nanoparticles containing Ni-NTA affinity group were synthesized and used for the separation of histidine tag proteins from the complex matrices through the use of imidazole side chains of histidine molecules. Firstly, CoFe2O4 nanoparticles with a narrow size distribution were prepared in an aqueous solution using the controlled co-precipitation method. In order to obtain small CoFe2O4 agglomerates, oleic acid and sodium chloride were used as dispersants. The CoFe2O4 particles were coated with silica and subsequently the surface of these silica coated particles (SiO2-CoFe2O4) was modified by amine (NH2) groups in order to add further functional groups on the silica shell. Then, carboxyl (-COOH) functional groups were added to the SiO2-CoFe2O4 magnetic nanoparticles through the NH2 groups. After that Nα,Nα-Bis(carboxymethyl)-L-lysine hydrate (NTA) was attached to carboxyl ends of the structure. Finally, the surface modified nanoparticles were labeled with nickel (Ni) (II) ions. Furthermore, the modified SiO2-CoFe2O4 magnetic nanoparticles were utilized as a new system that allows purification of the N-terminal His-tagged recombinant small heat shock protein, Tpv-sHSP 14.3.

  20. Preparation and characterization of PEG-coated silica nanoparticles for oral insulin delivery.

    Science.gov (United States)

    Andreani, Tatiana; de Souza, Ana Luiza R; Kiill, Charlene P; Lorenzón, Esteban N; Fangueiro, Joana F; Calpena, Ana Cristina; Chaud, Marco V; Garcia, Maria L; Gremião, Maria Palmira D; Silva, Amélia M; Souto, Eliana B

    2014-10-01

    The present study reports the production and characterization of PEG-coated silica nanoparticles (SiNP-PEG) containing insulin for oral administration. High (PEG 20,000) and low (PEG 6000) PEG molecular weights were used in the preparations. SiNP were produced by sol-gel technology followed by PEG adsorption and characterized for in vitro release by Franz diffusion cells. In vitro permeation profile was assessed using everted rat intestine. HPLC method has been validated for the determination of insulin released and permeated. Insulin secondary structure was performed by circular dichroism (CD). Uncoated SiNP allowed slower insulin release in comparison to SiNP-PEG. The coating with high molecular weight PEG did not significantly (p> 0.05) alter insulin release. The slow insulin release is attributed to the affinity of insulin for silanol groups at silica surface. Drug release followed second order kinetics for uncoated and SiNP-PEG at pH 2.0. On the other hand, at pH 6.8, the best fitting was first-order for SiNP-PEG, except for SiNP which showed a Boltzmann behavior. Comparing the values of half-live, SiNP-PEG 20,000 showed a faster diffusion followed by Si-PEG 6000 and SiNP. CD studies showed no conformational changes occurring after protein release from the nanoparticles under gastrointestinal simulated conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Glaze Icing on Superhydrophobic Coating Prepared by Nanoparticles Filling Combined with Etching Method for Insulators

    Directory of Open Access Journals (Sweden)

    Chao Guo

    2015-01-01

    Full Text Available Icing on insulators may cause flashover or even blackout accidents in the power transmission system. However, there are few anti-icing techniques for insulators which consume energy or manpower. Considering the water repelling property, the superhydrophobic surface is introduced for anti-icing of insulators. Among the icing forms, the glaze icing owns the highest density, strongest adhesion, and greatest risk to the power transmission system but lacks researches on superhydrophobic surface. In this paper, superhydrophobic surfaces with contact angle of 166.4°, contact angle hysteresis of 0.9°, and sliding angle of less than 1° are prepared by nanoparticle filling combined with etching method. The coated glass slide and glass insulator showed excellent anti-icing performance in the glaze icing test at −5°C. The superhydrophobicity and anti-icing property of the coatings benefit from the low surface energy and hierarchical rough structure containing micron scale pits and nanoscale coralloid bulges supported by scanning electron microscopy (SEM, atomic force microscopy (AFM, and X-ray photoelectron spectroscopy (XPS characterization.

  2. Preparation and optical properties of hybrid coatings based on epoxy-modified silane and rhodamine B

    Energy Technology Data Exchange (ETDEWEB)

    Zareba-Grodz, Iwona [Institute of Material Sciences and Applied Mechanics, Wroclaw University of Technology, Smoluchowskiego 25, 57-370 Wroclaw (Poland); Pazik, Robert [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-950 Wroclaw (Poland); Hermanowicz, Krzysztof [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-950 Wroclaw (Poland); Strek, Wieslaw [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-950 Wroclaw (Poland); Maruszewski, Krzysztof [Institute of Material Sciences and Applied Mechanics, Wroclaw University of Technology, Smoluchowskiego 25, 57-370 Wroclaw (Poland) and Electrotechnical Institute, Wroclaw Division, M. Sklodowskiej-Curie 55/61, 50-369 Wroclaw (Poland)]. E-mail: Krzysztof.Maruszewski@pwr.wroc.pl

    2006-07-15

    Amorphous silica materials have been successfully prepared by the controlled hydrolysis of tetraethoxysilane and glycidyloxypropyltrimethoxysilane. The rhodamine B has been introduced into the hydrolized silicate solutions. Thin films have been obtained by spin-coating of the obtained hydrolizates on quartz glass substrates. The morphology of the resulting thin-film samples have been characterized by optical and atomic force microscopies. The spectroscopic properties of samples have been characterized by FT IR and UV-VIS-NIR absorption measurements. The photoluminescence spectra have been recorded at room temperature. The emission of the hybrid materials doped with the dye exposed to UV radiation as a function of laser pulses has been measured. Basic physicochemical properties of the modified silica materials have also been determined.

  3. Preparation and evaluation of glyceryl monooleate-coated hollow-bioadhesive microspheres for gastroretentive drug delivery.

    Science.gov (United States)

    Liu, Yuanfen; Zhang, Jianjun; Gao, Yuan; Zhu, Jiabi

    2011-07-15

    The purpose of this study was to produce hollow and bioadhesive microspheres to lengthen drug retention time in the stomach. In these microspheres, ethylcellulose was used as the matrix, Eudragit EPO was employed to modulate the release rate, and glyceryl monooleate (GMO) was the bioadhesive polymer in situ. The morphological characteristics of the microspheres were defined using scanning electron microscopy. The in vitro release test showed that the release rate of drug from the microspheres was pH-dependent, and was not influenced by the GMO coating film. The prepared microspheres demonstrated strong mucoadhesive properties with good buoyancy both in vitro and in vivo. Pharmacokinetic analysis indicated that the elimination half-life time of the hollow-bioadhesive microspheres was prolonged, and that the elimination rate was decreased. In conclusion, the hollow-bioadhesive synergic drug delivery system may be advantageous in the treatment of stomach diseases. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Survival in vivo of platelets stored for 48 hours in the buffycoat at 4 degrees C compared to platelet rich plasma stored at 22 degrees C

    NARCIS (Netherlands)

    Pietersz, R. N.; Loos, J. A.; Reesink, H. W.

    1987-01-01

    High speed centrifugation allows separation of whole blood into cell free plasma, a buffy coat and leukocyte poor red cells. The buffy coat can be used for the preparation of platelet concentrates. High lactate production at 22 degrees C requires storage of the buffy coat at 4 degrees C. Survival in

  5. Neutral hydrophilic coatings for capillary electrophoresis prepared by controlled radical polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Fabián H.; Gómez, Jorge E.; Espinal, José H.; Sandoval, Junior E., E-mail: junior.sandoval@correounivalle.edu.co

    2016-12-15

    In the present study, porous silica particles as well as impervious fused-silica wafers and capillary tubes were modified with hydrophilic polymers (hydroxylated polyacrylamides and polyacrylates), using a surface-confined grafting procedure based on atom transfer radical polymerization (ATRP) which was also surface-initiated from α-bromoisobutyryl groups. Initiator immobilization was achieved by hydrosilylation of allyl alcohol on hydride silica followed by esterification of the resulting propanol-bonded surface with α-bromoisobutyryl bromide. Elemental analysis, IR and NMR spectroscopies on silica micro-particles, atomic force microscopy, ellipsometry and profilometry on fused-silica wafers, as well as CE on fused-silica tubes were used to characterize the chemically modified silica substrate at different stages. We studied the effect of monomer concentration as well as cross-linker on the ability of the polymer film to reduce electroosmosis and to prevent protein adsorption (i. e., its non-fouling capabilities) and found that the former was rather insensitive to both parameters. Surface deactivation towards adsorption was somewhat more susceptible to monomer concentration and appeared also to be favored by a low concentration of the cross-linker. The results show that hydrophilic polyacrylamide and polyacrylate coatings of controlled thickness can be prepared by ATRP under very mild polymerization conditions (aqueous solvent, room temperature and short reaction times) and that the coated capillary tubes exhibit high efficiencies for protein separations (0.3–0.6 million theoretical plates per meter) as well as long-term hydrolytic stability under the inherently harsh conditions of capillary isoelectric focusing. Additionally, there was no adsorption of lysozyme on the coated surface as indicated by a complete recovery of the basic enzyme. Furthermore, since polymerization is confined to the inner capillary surface, simple precautions (e.g., solution

  6. Preparation and characterization of 6-mercaptopurine-coated magnetite nanoparticles as a drug delivery system

    Directory of Open Access Journals (Sweden)

    Dorniani D

    2013-09-01

    Full Text Available Dena Dorniani,1 Mohd Zobir bin Hussein,1 Aminu Umar Kura,2 Sharida Fakurazi,2 Abdul Halim Shaari,3 Zalinah Ahmad4 1Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology, 2Vaccines and Immunotherapeutics Laboratory, 3Physics Department, Faculty of Science, 4Chemical Pathology Unit, Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia Background: Iron oxide nanoparticles are of considerable interest because of their use in magnetic recording tape, ferrofluid, magnetic resonance imaging, drug delivery, and treatment of cancer. The specific morphology of nanoparticles confers an ability to load, carry, and release different types of drugs. Methods and results: We synthesized superparamagnetic nanoparticles containing pure iron oxide with a cubic inverse spinal structure. Fourier transform infrared spectra confirmed that these Fe3O4 nanoparticles could be successfully coated with active drug, and thermogravimetric and differential thermogravimetric analyses showed that the thermal stability of iron oxide nanoparticles coated with chitosan and 6-mercaptopurine (FCMP was markedly enhanced. The synthesized Fe3O4 nanoparticles and the FCMP nanocomposite were generally spherical, with an average diameter of 9 nm and 19 nm, respectively. The release of 6-mercaptopurine from the FCMP nanocomposite was found to be sustained and governed by pseudo-second order kinetics. In order to improve drug loading and release behavior, we prepared a novel nanocomposite (FCMP-D, ie, Fe3O4 nanoparticles containing the same amounts of chitosan and 6-mercaptopurine but using a different solvent for the drug. The results for FCMP-D did not demonstrate “burst release” and the maximum percentage release of 6-mercaptopurine from the FCMP-D nanocomposite reached about 97.7% and 55.4% within approximately 2,500 and 6,300 minutes when exposed to pH 4.8 and pH 7.4 solutions, respectively

  7. Anisotropic SmCo5/FeCo core/shell nanocomposite chips prepared via electroless coating

    Directory of Open Access Journals (Sweden)

    Narayan Poudyal

    2015-08-01

    Full Text Available We report the preparation of anisotropic SmCo5/FeCo core/shell nanocomposite chip-like particles via an electroless coating process. The anisotropic SmCo5 nanoscale chips were first prepared by surfactant-assisted ball milling then coated with soft magnetic FeCo using cobalt sulfate (CoSO4.7H2O and iron sulfate (FeSO4.7H2O as metal precursors in presence of complexing agents. The influence of the soft-phase coating on the magnetic properties of the nanocomposite particles has been studied. The saturation magnetization of the composite particles increases with increasing coating while the coercivity decreases. The FeCo coated chips have an enhanced remanence (Mr = 44.5 emu/g with 16 wt % of FeCo compared to the uncoated chips (Mr = 36.7 emu/g, indicating exchange coupling between the hard and soft phases for the optimal soft-phase coating. Results of magnetic field alignment show the strong anisotropy of SmCo5/FeCo core/shell nanocomposite particles which can be used as building blocks of high-strength anisotropic magnets.

  8. Preparation and Evaluation of Diclofenac Sodium Tablet Coated with Polyelectrolyte Multilayer Film Using Hypromellose Acetate Succinate and Polymethacrylates for pH-Dependent, Modified Release Drug Delivery

    National Research Council Canada - National Science Library

    Jeganathan, Balamurugan; Prakya, Vijayalakshmi; Deshmukh, Abhijit

    2016-01-01

    .... The prepared IPCs were investigated using Fourier transform infrared spectroscopy. Diclofenac sodium (DS) tablets were prepared and were coated with polymer solution of HPMCAS and EE to achieve pH-dependent and sustained-release tablets...

  9. Preparation and corrosion resistance of magnesium phytic acid/hydroxyapatite composite coatings on biodegradable AZ31 magnesium alloy.

    Science.gov (United States)

    Zhang, Min; Cai, Shu; Zhang, Feiyang; Xu, Guohua; Wang, Fengwu; Yu, Nian; Wu, Xiaodong

    2017-06-01

    In this work, a magnesium phytic acid/hydroxyapatite composite coating was successfully prepared on AZ31 magnesium alloy substrate by chemical conversion deposition technology with the aim of improving its corrosion resistance and bioactivity. The influence of hydroxyapatite (HA) content on the microstructure and corrosion resistance of the coatings was investigated. The results showed that with the increase of HA content in phytic acid solution, the cracks on the surface of the coatings gradually reduced, which subsequently improved the corrosion resistance of these coated magnesium alloy. Electrochemical measurements in simulated body fluid (SBF) revealed that the composite coating with 45 wt.% HA addition exhibited superior surface integrity and significantly improved corrosion resistance compared with the single phytic acid conversion coating. The results of the immersion test in SBF showed that the composite coating could provide more effective protection for magnesium alloy substrate than that of the single phytic acid coating and showed good bioactivity. Magnesium phytic acid/hydroxyapatite composite, with the desired bioactivity, can be synthesized through chemical conversion deposition technology as protective coatings for surface modification of the biodegradable magnesium alloy implants. The design idea of the new type of biomaterial is belong to the concept of "third generation biomaterial". Corrosion behavior and bioactivity of coated magnesium alloy are the key issues during implantation. In this study, preparation and corrosion behavior of magnesium phytic acid/hydroxyapatite composite coatings on magnesium alloy were studied. The basic findings and significance of this paper are as follows: 1. A novel environmentally friendly, homogenous and crack-free magnesium phytic acid/hydroxyapatite composite coating was fabricated on AZ31 magnesium alloy via chemical conversion deposition technology with the aim of enhancing its corrosion resistance and

  10. Nanoemulsions coated with alginate/chitosan as oral insulin delivery systems: preparation, characterization, and hypoglycemic effect in rats

    OpenAIRE

    Li X; Qi J; Xie Y; Zhang X; Hu S; Xu Y.; Lu Y; Wu W

    2012-01-01

    Xiaoyang Li, Jianping Qi, Yunchang Xie, Xi Zhang, Shunwen Hu, Ying Xu, Yi Lu, Wei WuKey Laboratory of Smart Drug Delivery of Ministry of Education and People's Liberation Army (PLA), School of Pharmacy, Fudan University, Shanghai, ChinaAbstract: This study aimed to prepare nanoemulsions coated with alginate/chitosan for oral insulin delivery. Uncoated nanoemulsions were prepared by homogenization of a water in oil in water (w/o/w) multiple emulsion that was composed of Labrafac&re...

  11. Helium permeability of different structure pyrolytic carbon coatings on graphite prepared at low temperature and atmosphere pressure

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jinliang, E-mail: jlsong1982@yeah.net [Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Zhao, Yanling [School of Materials Science and Engineering, University of Jinan, Jinan 250022 (China); Zhang, Wenting [Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); School of Materials Science and Engineering, University of Jinan, Jinan 250022 (China); He, Xiujie; Zhang, Dongsheng; He, Zhoutong; Gao, Yantao; Jin, Chan; Xia, Huihao; Wang, Jianqiang; Huai, Ping; Zhou, Xingtai [Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2016-01-15

    Low density isotropic pyrolytic carbon (IPyC) and high density anisotropic pyrolytic carbon (APyC) coatings have been prepared at low temperature and atmosphere pressure. Helium gas permeabilities of nuclear graphite coated with IPyC and APyC of different thickness are studied using a vacuum apparatus. Both the permeation rates of the treated graphite gradually decrease with the increasing thickness of the coatings. The IPyC and APyC coatings can reduce the gas permeability coefficient of the samples by three and five orders of magnitude, respectively. The permeability difference is related to the microscopic structure, i.e., pores, as confirmed by scanning electron microscopy, mercury injection and X-ray tomography experiments. The changes of the permeability owing to heat cycles are observed to be negligible.

  12. Preparation of pellets containing highly soluble drug by extrusion/spheronisation and coating with Kollicoat® SR 30D

    Directory of Open Access Journals (Sweden)

    Itamar Francisco Andreazza

    2011-04-01

    Full Text Available The aim of this study was to prepare and evaluate the pellets, containing a highly soluble drug (ascorbic acid, by the extrusion-spheronization process and coated with a release controlling polymer. The coating (undertaken in a fluid bed was applied to three batches of the pellets with a dispersion of Kollicoat® SR 30 D, with each batch of pellets receiving a different level of polymer (5.07; 8.26 and 10.35%. The coated pellets were evaluated for sphericity by imaging analysis and comparative dissolution profile with a product commercially available in Brazil. All of the evaluated samples presented adequate physical properties and the dissolution profile of those coated with 5.07% of polymer proved to be similar to that of the commercially available brand name.

  13. Facile preparation of polyvinyl alcohol coated SiO2 stationary phases for high performance liquid chromatography.

    Science.gov (United States)

    Ji, Shunli; Zhang, Feifang; Wu, Shengjie; Yang, Bingcheng; Liang, Xinmiao

    2014-11-07

    A facile method to prepare a polar stationary phase for hydrophilic interaction chromatography (HILIC) was proposed by coating polyvinyl alcohol onto silica particles (PVA-Sil). A water or organic solvent-insoluble permanent PVA coating on the silica particle surface can be formed simply by dipping silica particles into a hot PVA solution and then settled from this solution, leaving a thin layer of PVA coating and frozen in a freezer. The PVA-Sil shields the silica core from solution erosion to some degree and the pH tolerance range was extended to 9.5 from 8.0 for bare silica. PVA-Sil demonstrated a good hydrophilic property for several kinds of polar compounds and ∼57000 m(-1) of plate count was achieved. This method can also be extended as a universal method to prepare various stationary phases with exchangeable functionalities by doping the desired ingredient in a PVA solution.

  14. Preparation and characterization of polymer nanocomposites coated magnetic nanoparticles for drug delivery applications

    Science.gov (United States)

    Prabha, G.; Raj, V.

    2016-06-01

    In the present research work, the anticancer drug 'curcumin' is loaded with Chitosan (CS)-polyethylene glycol (PEG)-polyvinylpyrrolidone (PVP) (CS-PEG-PVP) polymer nanocomposites coated with superparamagnetic iron oxide (Fe3O4) nanoparticles. The system can be used for targeted and controlled drug delivery of anticancer drugs with reduced side effects and greater efficiency. The prepared nanoparticles were characterized by Fourier transmission infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Curcumin drug loaded Fe3O4-CS, Fe3O4-CS-PEG and Fe3O4-CS-PEG-PVP nanoparticles exhibited the mean particle size in the range of 183-390 nm with a zeta potential value of 26-41 mV as measured using Malvern Zetasizer. The encapsulation efficiency, loading capacity and in-vitro drug release behavior of curcumin drug loaded Fe3O4-CS, Fe3O4-CS-PEG and Fe3O4-CS-PEG-PVP nanoparticles were studied using UV spectrophotometer. Besides, the cytotoxicity of the prepared nanoparticles using MTT assay was also studied. The curcumin drug release was examined at different pH medium and it was proved that the drug release depends upon the pH medium in addition to the nature of matrix.

  15. Facile preparation of carbohydrate microarrays by site-specific, covalent immobilization of unmodified carbohydrates on hydrazide-coated glass slides.

    Science.gov (United States)

    Lee, Myung-Ryul; Shin, Injae

    2005-09-15

    [reaction: see text] A new, simple and efficient immobilization method to attach mono-, di-, oligo-, and polysaccharides to hydrazide-coated glass slides was developed. Protein and cell-binding experiments show that the carbohydrate microarrays prepared by this method are applicable for the rapid analysis of protein-carbohydrate interactions and fast detection of pathogens.

  16. Enhanced oral bioavailability of novel mucoadhesive pellets containing valsartan prepared by a dry powder-coating technique

    DEFF Research Database (Denmark)

    Cao, Qing-Ri; Liu, Yan; Xu, Wei-Juan

    2012-01-01

    The aim of this study was to develop novel mucoadhesive pellets containing valsartan (VAL) with enhanced oral bioavailability. Two types of VAL loaded core pellets were prepared by an extrusion/spheronization method, and further dry-coated with a mixture of hydroxypropylmethylcellulose (HPMC) and...

  17. One-directional uniformly coated fibers, method of preparation, and uses therefor

    Science.gov (United States)

    Newkirk, L.R.; Valencia, F.A.; Riley, R.E.; Wallace, T.C. Sr.

    A problem addressed by this invention was how to obtain very long lengths of refractory metal-coated multifilamentary yarns having a uniform coating on the filaments which make up each yarn, the coating being uniform throughout the length of the yarn such that the coated yarns are suitable for being woven and are suitable for a variety of other uses. The solution is a continuous process which employs a chemical vapor deposition reaction at relatively low temperature and pressure and a separation of the gaseous reaction products from the coated yarn prior to allowing the coated yarn to cool.

  18. Facile preparation of superamphiphobic epoxy resin/modified poly(vinylidene fluoride)/fluorinated ethylene propylene composite coating with corrosion/wear-resistance

    Science.gov (United States)

    Wang, Huaiyuan; Liu, Zhanjian; Wang, Enqun; Zhang, Xiguang; Yuan, Ruixia; Wu, Shiqi; Zhu, Yanji

    2015-12-01

    A robust superamphiphobic epoxy resin (EP)/modified poly(vinylidene fluoride) (MPVDF)/fluorinated ethylene propylene (FEP) composite coating has been prepared through the combination of chemical modification and spraying technique. Nanometer silica (SiO2, 2.5 wt.%) and carbon nanotubes (CNTs, 2.5 wt.%) were added in the coating to construct the necessary reticulate papillae structures for superamphiphobic surface. The prepared EP composite coating demonstrated high static contact angles (166°, 155°) and low sliding angles (3°, 5°) to water and glycerol, respectively. Moreover, the prepared coating can also retain superhydrophobicity under strongly acidic and alkaline conditions. The brittleness of EP can be avoided by introducing the malleable MPVDF. The wear life of the EP composite coating with 25 wt.% FEP was improved to 18 times of the pure EP coating. The increased wear life of the coating can be attributed to the designed nano/micro structures, the self-lubrication of FEP and the chemical reaction between EP and MPVDF. The anti-corrosion performance of the coatings was investigated in 3.5% NaCl solution using potentiodynamic polarization. The results showed that the prepared superamphiphobic composite coating was most effective in corrosion resistance, primarily due to the barrier effect for the diffusion of O2 and H2O molecules. It is believed that this robust superamphiphobic EP/MPVDF/FEP composite coating prepared by the facile spray method can pave a way for the large-scale application in pipeline transport.

  19. Preparation and characterization of hydroxyapatite-coated iron oxide particles by spray-drying technique

    Directory of Open Access Journals (Sweden)

    karina Donadel

    2009-06-01

    Full Text Available Magnetic particles of iron oxide have been increasingly used in medical diagnosis by magnetic resonance imaging and in cancer therapies involving targeted drug delivery and magnetic hyperthermia. In this study we report the preparation and characterization of iron oxide particles coated with bioceramic hydroxyapatite by spray-drying. The iron oxide magnetic particles (IOMP were coated with hydroxyapatite (HAp by spray-drying using two IOMP/HAp ratios (0.7 and 3.2. The magnetic particles were characterized by way of scanning electronic microscopy, energy dispersive X-ray, X-ray diffraction, Fourier transformed infrared spectroscopy, flame atomic absorption spectrometry,vibrating sample magnetometry and particle size distribution (laser diffraction. The surface morphology of the coated samples is different from that of the iron oxide due to formation of hydroxyapatite coating. From an EDX analysis, it was verified that the surface of the coated magnetic particles is composed only of HAp, while the interior containsiron oxide and a few layers of HAp as expected. The results showed that spray-drying technique is an efficient and relatively inexpensive method for forming spherical particles with a core/shell structure.As partículas de óxido de ferro têm sido extensivamente usadas em diagnósticos médicos como agente de contraste para imagem por ressonância magnética e na terapia do câncer, dentre estas, liberação de fármacos em sitos alvos e hipertermia magnética. Neste estudo nós reportamos a preparação e caracterização de partículas magnéticas de óxido de ferro revestidas com a biocerâmica hidroxiapatita. As partículas magnéticasde óxido de ferro (PMOF foram revestidas com hidroxiapatita por spray-drying usando duas razões PMOF/HAp (0,7 e 3,2. As partículas magnéticas foram caracterizadas por microscopia eletrônica de varredura, energia dispersiva de raios X, difração de raios X, espectroscopia de absorção no infra

  20. Preparation and characterization of lanthanum-incorporated hydroxyapatite coatings on titanium substrates

    National Research Council Canada - National Science Library

    Lou, W; Dong, Y; Zhang, H; Jin, Y; Hu, X; Ma, J; Liu, J; Wu, G

    2015-01-01

    ...) coating, using a dip-coating technique with a La-HA sol along with post-heat treatment. The XRD, FTIR and EDX results presented in this paper confirmed that lanthanum was successfully incorporated into the structure of HA...

  1. Effect of Pulsed Waterjet Surface Preparation on the Adhesion Strength of Cold Gas Dynamic Sprayed Aluminum Coatings

    Science.gov (United States)

    Samson, T.; MacDonald, D.; Fernández, R.; Jodoin, B.

    2015-08-01

    It has been observed that the method of substrate surface preparation can have a profound effect on the adhesion strength of cold-sprayed metallic coatings. In this investigation, pure aluminum powder was sprayed onto aluminum alloy substrates using cold spray. The substrates used in this work had undergone a variety of surface preparations to impart varying degrees of surface roughness. The pulsed waterjet technique was used to increase the substrates' surface roughness beyond what can be achieved using traditional grit blasting procedures. Surfaces prepared using pulsed waterjet resulted in substantial increases in the pure aluminum coating adhesion strength. This increase may be the result of increased mechanical anchoring sites available as well as their favorable geometries. It is hypothesized that compressive residual stress may also contribute to increased adhesion strength.

  2. Microwave assisted radiant heating effect on the crystallization of SnO2 thin films prepared by spin-coating

    Science.gov (United States)

    Gome, Anil; Reddy, V. Raghavendra; Ganesan, V.; Gupta, Ajay

    2017-05-01

    Crystallization study of SnO2 thin films prepared by spin-coating method are reported when subjected to microwave assisted radiant heating (MARH). The as-prepared and annealed films are studied using atomic force microscopy, grazing incidence x-ray diffraction and conversion electron Mossbauer spectroscopy measurements. Sn4+ state in all films is confirmed from 119Sn Mossbauer spectroscopy measurements. The results indicate that one can employ microwave heating to prepare SnO2 thin films with controlled surface morphology which might be useful for various practical applications.

  3. Porous tantalum coatings prepared by vacuum plasma spraying enhance bmscs osteogenic differentiation and bone regeneration in vitro and in vivo.

    Science.gov (United States)

    Tang, Ze; Xie, Youtao; Yang, Fei; Huang, Yan; Wang, Chuandong; Dai, Kerong; Zheng, Xuebin; Zhang, Xiaoling

    2013-01-01

    Tantalum, as a potential metallic implant biomaterial, is attracting more and more attention because of its excellent anticorrosion and biocompatibility. However, its significantly high elastic modulus and large mechanical incompatibility with bone tissue make it unsuitable for load-bearing implants. In this study, porous tantalum coatings were first successfully fabricated on titanium substrates by vacuum plasma spraying (VPS), which would exert the excellent biocompatibility of tantalum and alleviate the elastic modulus of tantalum for bone tissue. We evaluated cytocompatibility and osteogenesis activity of the porous tantalum coatings using human bone marrow stromal cells (hBMSCs) and its ability to repair rabbit femur bone defects. The morphology and actin cytoskeletons of hBMSCs were observed via electron microscopy and confocal, and the cell viability, proliferation and osteogenic differentiation potential of hBMSCs were examined quantitatively by PrestoBlue assay, Ki67 immunofluorescence assay, real-time PCR technology and ALP staining. For in vivo detection, the repaired femur were evaluated by histomorphology and double fluorescence labeling 3 months postoperation. Porous tantalum coating surfaces promoted hBMSCs adhesion, proliferation, osteogenesis activity and had better osseointegration and faster new bone formation rate than titanium coating control. Our observation suggested that the porous tantalum coatings had good biocompatibility and could enhance osseoinductivity in vitro and promote new bone formation in vivo. The porous tantalum coatings prepared by VPS is a promising strategy for bone regeneration.

  4. Preparation of ZnO/Ag nanocomposite and coating on polymers for anti-infection biomaterial application.

    Science.gov (United States)

    Sadeghi, Babak

    2014-01-24

    ZnO/Ag nanocomposites coated with polyvinyl chloride (PVC) were prepared by chemical reduction method, for anti-infection biomaterial application. There is a growing interest in attempts in using biomolecular as the templates to grow inorganic nanocomposites in controlled morphology and structure. By optimizing the experiment conditions, we successfully fabricated high yield of ZnO/Ag nanocomposite with full coverage of high-density polyvinyl chloride (PVC) coating. More importantly, ZnO/Ag nanocomposites were shown to significantly inhibit the growth of Staphylococcus aureus in solution. It was further shown that ZnO/Ag nanocomposites induced thiol depletion that caused death of S. aureus. The coatings were fully characterized using techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Most importantly, compared to uncoated metals, the coatings on PVC promoted healthy antibacterial activity. Importantly, compared to ZnO-Ag -uncoated PVC, the ZnO/Ag nanocomposites coated was approximately triplet more effective in preventing bacteria attachment. The result of Thermal Gravimetric Analysis (TGA) indicates that, the ZnO/Ag nanocomposites are chemically stable in the temperature range from 50 to 900°C. This result, for the first time, demonstrates the potential of using ZnO/Ag nanocomposites as a coating material for numerous anti-bacterial applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Mechanical Properties And Microstructure Of AlN/SiCN Nanocomposite Coatings Prepared By R.F.-Reactive Sputtering Method

    Directory of Open Access Journals (Sweden)

    Nakafushi Y.

    2015-06-01

    Full Text Available FIn this work, AlN/SiCN composite coatings were deposited by r.f.-reactive sputtering method using a facing target-type sputtering (FTS apparatus with composite targets consisting of Al plate and SiC chips in a gaseous mixture of Ar and N2, and investigated their mechanical properties and microstructure. The indentation hardness (HIT of AlN/SiCN coatings prepared from composite targets consisting of 8 ~32 chips of SiC and Al plate showed the maximum value of about 29~32 GPa at a proper nitrogen gas flow rate. X-ray diffraction (XRD patterns for the AlN/SiCN composite coatings indicated the presence of the only peeks of hexagonal (B4 structured AlN phase. AlN coatings clarified the columnar structure of the cross sectional view TEM observation. On the other hand, microstructure of AlN/SiCN composite coatings changed from columnar to equiaxed structure with increasing SiCN content. HR-TEM observation clarified that the composite coatings consisted of very fine equiaxial grains of B4 structured AlN phase and amorphous phase.

  6. Porous tantalum coatings prepared by vacuum plasma spraying enhance bmscs osteogenic differentiation and bone regeneration in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Ze Tang

    Full Text Available Tantalum, as a potential metallic implant biomaterial, is attracting more and more attention because of its excellent anticorrosion and biocompatibility. However, its significantly high elastic modulus and large mechanical incompatibility with bone tissue make it unsuitable for load-bearing implants. In this study, porous tantalum coatings were first successfully fabricated on titanium substrates by vacuum plasma spraying (VPS, which would exert the excellent biocompatibility of tantalum and alleviate the elastic modulus of tantalum for bone tissue. We evaluated cytocompatibility and osteogenesis activity of the porous tantalum coatings using human bone marrow stromal cells (hBMSCs and its ability to repair rabbit femur bone defects. The morphology and actin cytoskeletons of hBMSCs were observed via electron microscopy and confocal, and the cell viability, proliferation and osteogenic differentiation potential of hBMSCs were examined quantitatively by PrestoBlue assay, Ki67 immunofluorescence assay, real-time PCR technology and ALP staining. For in vivo detection, the repaired femur were evaluated by histomorphology and double fluorescence labeling 3 months postoperation. Porous tantalum coating surfaces promoted hBMSCs adhesion, proliferation, osteogenesis activity and had better osseointegration and faster new bone formation rate than titanium coating control. Our observation suggested that the porous tantalum coatings had good biocompatibility and could enhance osseoinductivity in vitro and promote new bone formation in vivo. The porous tantalum coatings prepared by VPS is a promising strategy for bone regeneration.

  7. Mechanical and Anticorrosive Properties of Graphene/Epoxy Resin Composites Coating Prepared by in-Situ Method

    Directory of Open Access Journals (Sweden)

    Zhiyi Zhang

    2015-01-01

    Full Text Available The graphene nanosheets-based epoxy resin coating (0, 0.1, 0.4 and 0.7 wt % was prepared by a situ-synthesis method. The effect of polyvinylpyrrolidone/reduced graphene oxide (PVP-rGO on mechanical and thermal properties of epoxy resin coating was investigated using nanoindentation technique and thermogravimetric analysis, respectively. A significant enhancement (ca. 213% and 73 °C in the Young modulus and thermal stability of epoxy resin coating was obtained at a loading of 0.7 wt %, respectively. Furthermore, the erosion resistance of graphene nanosheets-based epoxy resin coating was investigated by electrochemical measurement. The results showed also that the Rrcco (ca. 0.3 mm/year of graphene nanosheets-based epoxy resin coating was far lower than neat epoxy resin (1.3 mm/year. Thus, this approach provides a novel route for improving erosion resistance and mechanical-thermal stability of polymers coating, which is expected to be used in mechanical-thermal-corrosion coupling environments.

  8. Mechanical and anticorrosive properties of graphene/epoxy resin composites coating prepared by in-situ method.

    Science.gov (United States)

    Zhang, Zhiyi; Zhang, Wenhui; Li, Diansen; Sun, Youyi; Wang, Zhuo; Hou, Chunling; Chen, Lu; Cao, Yang; Liu, Yaqing

    2015-01-20

    The graphene nanosheets-based epoxy resin coating (0, 0.1, 0.4 and 0.7 wt %) was prepared by a situ-synthesis method. The effect of polyvinylpyrrolidone/reduced graphene oxide (PVP-rGO) on mechanical and thermal properties of epoxy resin coating was investigated using nanoindentation technique and thermogravimetric analysis, respectively. A significant enhancement (ca. 213% and 73 °C) in the Young modulus and thermal stability of epoxy resin coating was obtained at a loading of 0.7 wt %, respectively. Furthermore, the erosion resistance of graphene nanosheets-based epoxy resin coating was investigated by electrochemical measurement. The results showed also that the Rrcco (ca. 0.3 mm/year) of graphene nanosheets-based epoxy resin coating was far lower than neat epoxy resin (1.3 mm/year). Thus, this approach provides a novel route for improving erosion resistance and mechanical-thermal stability of polymers coating, which is expected to be used in mechanical-thermal-corrosion coupling environments.

  9. Preparation and characterization of carbon/nickel oxide nanocomposite coatings for solar absorber applications

    Energy Technology Data Exchange (ETDEWEB)

    Roro, Kittessa T., E-mail: KRoro@csir.co.za [CSIR-National Laser Centre, P.O. Box 395, Pretoria 0001 (South Africa); Tile, Ngcali; Forbes, Andrew [CSIR-National Laser Centre, P.O. Box 395, Pretoria 0001 (South Africa); School of Physics, University of KwaZulu Natal, Private Bag X54001, Durban 5000 (South Africa)

    2012-07-01

    Nanocomposite materials have wide range of applications in solar energy conversion. In this work, C/NiO nanocomposite solar energy absorbing surfaces were prepared using sol-gel synthesis and deposited on aluminium substrates using a spin coater. The coatings were prepared from alcoholic sols based on Ni-acetate using diethalonamine as a chelating agent and polyethylene glycol (PEG) as organic template. Sucrose was used as a carbon source. Sols with different heating temperature and PEG concentrations were fabricated. Thermal analysis on the gel revealed that the xerogels weight loss stabilized at around 430 Degree-Sign C. It was found that the absorption edge shifts to the higher wavelength with an increase in the heating temperature in the temperature range studied, 300-550 Degree-Sign C, due to an increase in carbon content in the material. The main features of Raman spectra obtained from the composite films are the D and G bands, characteristic of graphitic carbon films. The G peak width narrowed while the ratio of the integrated intensities of the D and G peaks, I{sub D}/I{sub G}, increased with the heating temperature, suggesting a progressive increase of the graphitic domain within the films. The solar absorption property of the films was enhanced with the increase of PEG concentrations in the sols from 0 to 2 g and decreases with further increase of PEG. The best solar absorption, {alpha}{sub sol}, and the surface thermal emittance, {epsilon}{sub therm}, at 100 Degree-Sign C obtained were 85% and 5% for a single layer, respectively, yielding an optical selectivity S {alpha}{sub sol}/{epsilon}{sub therm} of 17.1.

  10. Carbon-coated copper nanoparticles prepared by detonation method and their thermocatalysis on ammonium perchlorate

    Directory of Open Access Journals (Sweden)

    Chongwei An

    2017-03-01

    Full Text Available Carbon-coated copper nanoparticles (CCNPs were prepared by initiating a high-density charge pressed with a mixture of microcrystalline wax, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX, and copper nitrate hydrate (Cu(NO32·3H2O in an explosion vessel filled with nitrogen gas. The detonation products were characterized by transmission electron microcopy (TEM, high resolution transmission electron microcopy (HRTEM, energy dispersive X-ray spectroscopy (EDX, X-ray diffraction (XRD, and Raman spectroscopy. The effects of CCNPs on thermal decomposition of ammonium perchlorate (AP were also investigated by differential scanning calorimeter (DSC. Results indicated that the detonation products were spherical, 25-40 nm in size, and had an apparent core-shell structure. In this structure, the carbon shell was 3-5 nm thick and mainly composed of graphite, C8 (a kind of carbyne, and amorphous carbon. When 5 wt.% CCNPs was mixed with 95 wt.% AP, the high-temperature decomposition peak of AP decreased by 95.97, 96.99, and 96.69 °Cat heating rates of 5, 10, and 20 °C/min, respectively. Moreover, CCNPs decreased the activation energy of AP as calculated through Kissinger’s method by 25%, which indicated outstanding catalysis for the thermal decomposition of AP.

  11. Investigation of Ag-TiO2 nanostructures photocatalytic properties prepared by modified dip coating method

    Science.gov (United States)

    AlArfaj, Esam

    2016-05-01

    In this article, titanium dioxide and silver nanostructures were deposited on glass substrates using modified sol-gel methods and dip-coating technique. The films were characterised chemically and physically using different techniques (TLC, UV-Vis and XRD) and tested for environmental applications regarding degradation of aromatic hydrocarbons. The photocatalytic activity of the TiO2 nanostructures is tested with different small concentrations of phenol in water and reaction mechanisms discussed. Considerable enhancement is observed in the photodegradation activity of Ag-modified (3 wt.%) TiO2 compared to unmodified TiO2 nanostructures for phenol concentrations within the pseudo-first-order Langmuir-Hinshelwood (LH) model for reaction kinetics. The pseudo-first-order global degradation rate constant increased from absorption to the visible region by its surface plasmon resonances and to suppress the anatase-rutile phase transformation. Moreover, TiO2 grain size prepared was found to be 10 nm which maximises the active surface area. For phenol initial concentrations as low as 0.0002 M, saturation trend in the degradation process occurred at 0.00014 M and the reaction rate can be fitted with half-order LH kinetics.

  12. Carbon-coated copper nanoparticles prepared by detonation method and their thermocatalysis on ammonium perchlorate

    Science.gov (United States)

    An, Chongwei; Ding, Penghui; Ye, Baoyun; Geng, Xiaoheng; Wang, Jingyu

    2017-03-01

    Carbon-coated copper nanoparticles (CCNPs) were prepared by initiating a high-density charge pressed with a mixture of microcrystalline wax, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and copper nitrate hydrate (Cu(NO3)2.3H2O) in an explosion vessel filled with nitrogen gas. The detonation products were characterized by transmission electron microcopy (TEM), high resolution transmission electron microcopy (HRTEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Raman spectroscopy. The effects of CCNPs on thermal decomposition of ammonium perchlorate (AP) were also investigated by differential scanning calorimeter (DSC). Results indicated that the detonation products were spherical, 25-40 nm in size, and had an apparent core-shell structure. In this structure, the carbon shell was 3-5 nm thick and mainly composed of graphite, C8 (a kind of carbyne), and amorphous carbon. When 5 wt.% CCNPs was mixed with 95 wt.% AP, the high-temperature decomposition peak of AP decreased by 95.97, 96.99, and 96.69 °Cat heating rates of 5, 10, and 20 °C/min, respectively. Moreover, CCNPs decreased the activation energy of AP as calculated through Kissinger's method by 25%, which indicated outstanding catalysis for the thermal decomposition of AP.

  13. Preparation and characterization of polypyrrole coating on fly ash cenospheres: role of the organosilane treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wang Bing; Li Qin; Kang Jinfang; Pang Jianfeng; Wang Wei; Zhai Jianping, E-mail: jpzhai@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, and School of the Environment, Nanjing University, Nanjing 210046 (China)

    2011-10-19

    The preparation of hybrid polypyrrole-fly ash cenospheres (PPY-FACs) is well documented. In order to create a suitable surface environment in favour of the formation of PPY, organofunctional modification of FACs' surface by different silane coupling agents is introduced prior to the PPY coating. The organosilanes used to treat the substrates are aminopropyltriethoxysilane (APS) and mercaptopropyltrimethoxysilane (MPTS). These hybrid PPY-FACs are characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy and contact angle measurement. These characterization results indicate that organosilane pretreatment contributes to the formation of PPY at the surface of FACs. Compared with MPTS, APS yields stronger bonding force between PPY and substrate surface, and thus is better for the loading of PPY due to the superior hydrophobic property. In addition, the introduction of FACs avoids the removal process of the template core to form a hollow structure because of the special structure of the substrates, which makes the process convenient and environmentally benign.

  14. Preparation and characterization of polypyrrole coating on fly ash cenospheres: role of the organosilane treatment

    Science.gov (United States)

    Wang, Bing; Li, Qin; Kang, Jinfang; Pang, Jianfeng; Wang, Wei; Zhai, Jianping

    2011-10-01

    The preparation of hybrid polypyrrole-fly ash cenospheres (PPY-FACs) is well documented. In order to create a suitable surface environment in favour of the formation of PPY, organofunctional modification of FACs' surface by different silane coupling agents is introduced prior to the PPY coating. The organosilanes used to treat the substrates are aminopropyltriethoxysilane (APS) and mercaptopropyltrimethoxysilane (MPTS). These hybrid PPY-FACs are characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy and contact angle measurement. These characterization results indicate that organosilane pretreatment contributes to the formation of PPY at the surface of FACs. Compared with MPTS, APS yields stronger bonding force between PPY and substrate surface, and thus is better for the loading of PPY due to the superior hydrophobic property. In addition, the introduction of FACs avoids the removal process of the template core to form a hollow structure because of the special structure of the substrates, which makes the process convenient and environmentally benign.

  15. Fiber-reinforced resin coating for endocrown preparations: a technical report.

    Science.gov (United States)

    Rocca, G T; Rizcalla, N; Krejci, I

    2013-01-01

    Coronal rehabilitation of endodontically treated posterior teeth is still a controversial issue. Although the use of classical crowns supported by radicular metal posts remains widespread in dentistry, their invasiveness has been largely criticized. New materials and therapeutic options based entirely on adhesion are available nowadays, from direct composite resins to indirect endocrowns. They allow for a more conservative, faster, and less expensive dental treatment. However, the absence of a metal or high-strength ceramic substructure as in full-crown restorations can expose this kind of restoration to a higher risk of irreversible fracture in case of crack propagation. The aim of this case report is to present a technique to reinforce the cavity of an endodontically treated tooth by incorporating a fiber-reinforced composite (FRC) layer into the resin coating of the tooth preparation, before the final impressions of the cavity. This technique allows the use of FRCs in combination with any kind of restorative material for an adhesive overlay/endocrown.

  16. High critical current density in YBCO coated conductors prepared by thermal co-evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Bindi, M [Edison Termoelettrica SpA, Foro Buonaparte 31, I-20121 Milan (Italy); Botarelli, A [Europa Metalli SpA, Superconductor Division, via Repubblica 257, I-55052 Fornaci di Barga, Lucca (Italy); Gauzzi, A [IMEM-CNR, Area delle Scienze 37/A, I-43010 Parma (Italy); Gianni, L [Edison Termoelettrica SpA, Foro Buonaparte 31, I-20121 Milan (Italy); Ginocchio, S [Edison Termoelettrica SpA, Foro Buonaparte 31, I-20121 Milan (Italy); Holzapfel, B [Institut fuer Festkoerper-und Werkstoffsforschung, Helmholtzstrasse 20, Dresden (Germany); Baldini, A [Europa Metalli SpA, Superconductor Division, via Repubblica 257, I-55052 Fornaci di Barga, Lucca (Italy); Zannella, S [Edison Termoelettrica SpA, Foro Buonaparte 31, I-20121 Milan (Italy)

    2004-03-01

    We report on the in situ preparation of Y Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} films uniformly deposited over large areas,>20 x 20 cm{sup 2}, at 690 C by thermal co-evaporation onto Ni-5 at.% W biaxially textured tapes buffered with e-beam evaporated CeO{sub 2}. Typically, the thickness of the YBCO and CeO{sub 2} layers was 0.9 and 0.1 {mu}m, respectively. Deposition rates were 0.2 and 2.5 nm s{sup -1}, respectively. X-ray diffraction {theta}-2{theta} Bragg-Brentano and pole figure measurements, and Nomarsky optical and SEM microscopy analysis show good biaxial texture of both layers, sharp interfaces and the absence of cracks. Midpoint critical temperatures, T{sub c}, fall reproducibly in the 87-88 K range with transition widths {delta}T{sub c} = 1 K. Remarkably high transport critical current densities, J{sub c}, in the 2.0-2.5 MA cm{sup -2} range are achieved at 77 K in 1 cm long samples. The above deposition route appears to be promising for the development of long-length YBCO coated conductors thanks to the relatively low deposition temperature, the high degree of uniformity over large areas and the simple single buffer layer architecture.

  17. Structural characterization of supported nanocrystalline ZnO thin films prepared by dip-coating

    Energy Technology Data Exchange (ETDEWEB)

    Casanova, J.R. [CITEDEF-CINSO-CONICET Centro de Investigaciones en Solidos, Juan B. de La Salle 4397, B1603ALO, Villa Martelli, Buenos Aires (Argentina); Heredia, E.A., E-mail: eheredia@citedef.gob.ar [CITEDEF-CINSO-CONICET Centro de Investigaciones en Solidos, Juan B. de La Salle 4397, B1603ALO, Villa Martelli, Buenos Aires (Argentina); Bojorge, C.D.; Canepa, H.R. [CITEDEF-CINSO-CONICET Centro de Investigaciones en Solidos, Juan B. de La Salle 4397, B1603ALO, Villa Martelli, Buenos Aires (Argentina); Kellermann, G. [Departamento de Fisica, Universidade Federal do Parana, Curitiba, PR (Brazil); Craievich, A.F. [Instituto de Fisica, Universidade de Sao Paulo, Cidade Universitaria, Sao Paulo, SP (Brazil)

    2011-09-15

    Nanocrystalline ZnO thin films prepared by the sol-gel dip-coating technique were characterized by grazing incidence X-ray diffraction (GIXD), atomic force microscopy (AFM), X-ray reflectivity (XR) and grazing incidence small-angle X-ray scattering (GISAXS). The structures of several thin films subjected to (i) isochronous annealing at 350, 450 and 550 deg. C, and (ii) isothermal annealing at 450 deg. C during different time periods, were characterized. The studied thin films are composed of ZnO nanocrystals as revealed by analysing several GIXD patterns, from which their average sizes were determined. Thin film thickness and roughness were determined from quantitative analyses of AFM images and XR patterns. The analysis of XR patterns also yielded the average density of the studied films. Our GISAXS study indicates that the studied ZnO thin films contain nanopores with an ellipsoidal shape, and flattened along the direction normal to the substrate surface. The thin film annealed at the highest temperature, T = 550 deg. C, exhibits higher density and lower thickness and nanoporosity volume fraction, than those annealed at 350 and 450 deg. C. These results indicate that thermal annealing at the highest temperature (550 deg. C) induces a noticeable compaction effect on the structure of the studied thin films.

  18. Preparation of calcium phosphate glass-ceramics and their coating on titanium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kasuga, T.; Nogami, M. [Nagoya Inst. of Tech. (Japan). Dept. of Materials Science and Engineering; Niinomi, M. [Toyohashi Univ. of Technology (Japan). Dept. of Production Systems Engineering

    2001-07-01

    Novel silica-free calcium phosphate glass-ceramics was prepared by heating a compact of 60CaO . 30P{sub 2}O{sub 5} . 3TiO{sub 2} . 7Na{sub 2}O glass powders. When powder-compacts of the glasses were heated at 850 C, they crystallized and subsequently sintered, resulting in glass-ceramics containing {beta}Ca{sub 3}(PO{sub 4}){sub 2} and {beta}-Ca{sub 2}P{sub 2}O{sub 7} crystalline phases. The glass-ceramics show relatively high mechanical strength of 100 {proportional_to} 120 MPa in bending and fracture toughness of K{sub IC} {approx} 1.9 MPa.m{sup 0.5}. Hydroxyapatite was formed newly on the surface of the glass-ceramic in simulated body fluid at 37 C. By heating a new type of titanium alloy (Ti-29Nb-13Ta-4.6Zr), on which the glass powders were placed, at 800 C in air, a glass-ceramic layer containing {beta}-Ca{sub 3}(PO{sub 4}){sub 2} crystal was found to be joined easily with the metal. The joining between the coating layer and the metal substrate is very strong in tensile bonding strength. (orig.)

  19. Silicate-entrapped porous coatings for preparing high-efficiency solid-phase microextraction sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Breton, Francois; Monton, Maria Rowena N. [University of Waterloo, Department of Chemistry, 200 University Ave. West, Waterloo, Ontario N2L 3G1 (Canada); Mullett, Wayne M. [MDS Nordion, 447 Marsh Road, Ottawa, Ontario K2K 1X8 (Canada); Pawliszyn, Janusz, E-mail: janusz@uwaterloo.ca [University of Waterloo, Department of Chemistry, 200 University Ave. West, Waterloo, Ontario N2L 3G1 (Canada)

    2010-06-11

    We present a novel way to prepare SPME fibers using a silicate entrapment of porous particles, followed by derivatization using classical organosilane chemistry. The fibers provide a good platform for on-fiber derivatization of desired extraction phases while providing porosity necessary for high extractions capacities. The porous network was created using potassium silicate and porous silica particles. Fibers derivatized using n-butyl, n-octyl, n-octadecyl and n-triacontyl groups were shown to extract benzodiazepines successfully. The coatings were determined to have an average thickness of ca. 8 {mu}m, as determined by a scanning electron microscope, permitting equilibrium times as fast as 2 min. The fibers also showed very good ruggedness towards a vast range of solvents and prolonged use. It was determined that greater extraction efficiencies could be obtained using triacontyl as an extraction phase. The C18 and C30 fibers were also found to provide good linearity (>0.99) for the model analytes over two orders of magnitude, with limits of detection in the sub ng mL{sup -1} levels. C30 fibers were used to establish a correlation between structurally diverse {beta}-blockers and their literature reported Log P values. The C30 fibers provided a good correlation (R{sup 2} = 0.9255) between {beta}-blockers ranging in hydrophobicity from Log P{sub literature} 0.16-4.15 and their respective experimentally determined Log K{sub spme} values.

  20. Comparison on mechanical properties of single layered and bilayered chitosan-gelatin coated porous hydroxyapatite scaffold prepared through freeze drying method

    Science.gov (United States)

    Effendi, M. D.; Gustiono, D.; Lukmana; Ayu, D.; Kurniawati, F.

    2017-02-01

    Biopolymer coated porous hydroxyapatite (HA) scaffolds were prepared for tissue engineering trough freeze drying method and impregnation. in this study, to mimic the mineral and organic component of natural bone, synthetic hydroxapatite (HA) scaffolds coated by polymer were prepared. Highly porous Hap scaffolds, fabricated by synthetic HA impregnation method on polyurethane foam, were coated with polymer coating solution, consisting of chitosan, Gelatin, and bilayered chitosan-gelatin prepared by aging and impregnating technique. For the purpose of comparison, The bare scaffolds without polymer coating layer were investigated. The Bare scaffolds were highly porous and interconnected with a pore size of around 150 µm-714 µm, has porosity at around 67,7% -85,7%, and has mechanical strength at around 0.06 Mpa - 0.071 Mpa, which is suitable for osteoblast cell Proliferation. Chitosan coated porous HA scaffold and gelatin coated porous HA scaffold had mechanical strength at around 0.81-0.85 Mpa, and 1.32-1.34 Mpa, respectively, with weight ratio of biopolymer and Hap was around 18%-22%. To compare these results, the coating on the bare scaffold with gelatin and chitosan had been conducted. Based on the result of FTIR, it could be concluded that coating procedure applied on porous hydroxy apatite (HA) coated by gelatin, chitosan coated HA scaffold, and bilayered Gelatin-chitosan coated porous HA scaffold, confirming that for allsampleshad no significant chemical effect on the coating structure. The compressive strength of bilayered Gelatin-chitosan coated HA scaffold had middle values between the rest, at around 1,06-1.2 Mpa for the samples at the same weight ratio of biopolymer: HA (around 18% - 22%). These results also confirming that coating by gelatin on porous hydroxyapatite was highest compresive strength and can be applied to improve mechanical properties of porous hydroxyapatite bare scaffold

  1. Preparation and properties of a coated slow-release and water-retention biuret phosphoramide fertilizer with superabsorbent.

    Science.gov (United States)

    Jin, Shuping; Yue, Guoren; Feng, Lei; Han, Yuqi; Yu, Xinghai; Zhang, Zenghu

    2011-01-12

    In this investigation, a novel water-insoluble slow-release fertilizer, biuret polyphosphoramide (BPAM), was formulated and synthesized from urea, phosphoric acid (H(3)PO(4)), and ferric oxide (Fe(2)O(3)). The structure of BPAM was characterized by Fourier transform infrared (FTIR) spectroscopy. Subsequently, a coated slow-release BPAM fertilizer with superabsorbent was prepared by ionic cross-linked carboxymethylchitosan (the core), acrylic acid, acrylamide, and active carbon (the coating). The variable influences on the water absorbency were investigated and optimized. Component analysis results showed that the coated slow-release BPAM contained 5.66% nitrogen and 11.7% phosphorus. The property of water retention, the behavior of slow release of phosphorus, and the capacity of adsorption of cations were evaluated, and the results revealed that the product not only had good slow-release property and excellent water retention capacity but also higher adsorption capacities of cations in saline soil.

  2. Preparation and characterization of polymer nanocomposites coated magnetic nanoparticles for drug delivery applications

    Energy Technology Data Exchange (ETDEWEB)

    Prabha, G., E-mail: gprabhagovinn@gmail.com; Raj, V., E-mail: alaguraj2@rediffmail.com

    2016-06-15

    In the present research work, the anticancer drug ‘curcumin’ is loaded with Chitosan (CS)-polyethylene glycol (PEG)-polyvinylpyrrolidone (PVP) (CS-PEG-PVP) polymer nanocomposites coated with superparamagnetic iron oxide (Fe{sub 3}O{sub 4}) nanoparticles. The system can be used for targeted and controlled drug delivery of anticancer drugs with reduced side effects and greater efficiency. The prepared nanoparticles were characterized by Fourier transmission infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Curcumin drug loaded Fe{sub 3}O{sub 4}-CS, Fe{sub 3}O{sub 4}-CS-PEG and Fe{sub 3}O{sub 4}-CS-PEG-PVP nanoparticles exhibited the mean particle size in the range of 183–390 nm with a zeta potential value of 26–41 mV as measured using Malvern Zetasizer. The encapsulation efficiency, loading capacity and in-vitro drug release behavior of curcumin drug loaded Fe{sub 3}O{sub 4}-CS, Fe{sub 3}O{sub 4}-CS-PEG and Fe{sub 3}O{sub 4}-CS-PEG-PVP nanoparticles were studied using UV spectrophotometer. Besides, the cytotoxicity of the prepared nanoparticles using MTT assay was also studied. The curcumin drug release was examined at different pH medium and it was proved that the drug release depends upon the pH medium in addition to the nature of matrix. - Highlights: • The considered drug carrier Fe{sub 3}O{sub 4}-CS-PEG-PVP nanoparticles were prepared and entrapping (Curcumin). • The amount of the drug had great effect on the drug LC and EE and zeta potential Nanocomposites. • The Curcumin- loaded Fe{sub 3}O{sub 4}-CS, Fe{sub 3}O{sub 4}-CS-PEG and Fe{sub 3}O{sub 4}-CS-PEG-PVP nanocomposites showed pH responsive drug release.

  3. Investigation into conductivity of silver-coated cenosphere composites prepared by a modified electroless process

    Science.gov (United States)

    Cao, Xiao Guo; Zhang, Hai Yan

    2013-01-01

    Silver-coated cenosphere composites are successfully fabricated by a modified electroless plating process that is modified by replacing the conventional pretreatment and sensitization steps by only using surface hydroxylation step to simplify the steps and reduce the overall cost of the coating process. Furthermore, the activation and electroless plating steps are merged into one step. The cenosphere particles are characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD) before and after the coating process. The relatively continuous and compact coating is obtained under the given coating conditions. The results indicated that the conductivity of Ag-coated cenospheres was improved with increasing the AgNO3 solution dosage and reaction time. It was also found that the optimum AgNO3 solution concentration was 0.05 mol/L, and the optimum range of reaction temperature was from 50 °C to 65 °C.

  4. Preparation and Performance of Plasma/Polymer Composite Coatings on Magnesium Alloy

    DEFF Research Database (Denmark)

    Bakhsheshi-Rad, H. R.; Hamzah, E.; Bagheriyan, S.

    2016-01-01

    A triplex plasma (NiCoCrAlHfYSi/Al2O3·13%TiO2)/polycaprolactone composite coating was successfully deposited on a Mg-1.2Ca alloy by a combination of atmospheric plasma spraying and dip-coating techniques. The NiCoCrAlHfYSi (MCrAlHYS) coating, as the first layer, contained a large number of voids,...

  5. Investigation into conductivity of silver-coated cenosphere composites prepared by a modified electroless process

    Energy Technology Data Exchange (ETDEWEB)

    Cao Xiaoguo, E-mail: xgcao@gdut.edu.cn [School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong 510006 (China); Zhang Haiyan [School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong 510006 (China)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer In this paper we described a modified eletroless Ag-coating process on cenospheres. Black-Right-Pointing-Pointer The modified method makes the plating process more cost-saving and with less steps. Black-Right-Pointing-Pointer The relatively uniform and continuous silver coating is obtained. Black-Right-Pointing-Pointer The effects of silver coating on cenospheres on conductivity were investigated. - Abstract: Silver-coated cenosphere composites are successfully fabricated by a modified electroless plating process that is modified by replacing the conventional pretreatment and sensitization steps by only using surface hydroxylation step to simplify the steps and reduce the overall cost of the coating process. Furthermore, the activation and electroless plating steps are merged into one step. The cenosphere particles are characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD) before and after the coating process. The relatively continuous and compact coating is obtained under the given coating conditions. The results indicated that the conductivity of Ag-coated cenospheres was improved with increasing the AgNO{sub 3} solution dosage and reaction time. It was also found that the optimum AgNO{sub 3} solution concentration was 0.05 mol/L, and the optimum range of reaction temperature was from 50 Degree-Sign C to 65 Degree-Sign C.

  6. Preparation and Electrochemical Properties of Graphene/Epoxy Resin Composite Coating

    Science.gov (United States)

    Liao, Zijun; Zhang, Tianchi; Qiao, Sen; Zhang, Luyihang

    2017-11-01

    The multilayer graphene powder as filler, epoxy modified silicone resin as film-forming agent, anticorrosion composite coating has been created using sand dispersion method, the electrochemical performance was compared with different content of graphene composite coating and pure epoxy resin coating. The open circuit potential (OCP), potentiodynamic polarization curves (Tafel Plot) and electrochemical impedance spectroscopy (EIS) were tested. The test results showed that the anti-corrosion performance of multilayer graphene added has improved greatly, and the content of the 5% best corrosion performance of graphene composite coating.

  7. Synthesis of SiO2-Coated Core-Shell ZnO Composites for Preparing High-Voltage Varistors

    Science.gov (United States)

    Qu, Xiao; Yao, Da-Chuan; Liu, Jin-Ran; Wang, Mao-Hua; Zhang, Han-Ping

    2017-09-01

    Monodispersed ZnO composite microspheres were successfully prepared by a facile ultrasound irradiation method. Then, the uniform core-shell structured composites were synthesized through the hydrolysis of tetraethyl orthosilicate on the surface of the ZnO composite microspheres. Microstructural studies of the as-obtained powders were carried out using the techniques of the x-ray powder diffraction, field emission scanning electron microscopy and transmission electron microscopy with energy dispersive x-ray spectroscopy. The results show that the pink ZnO composite powders as the core were spherical structures with the size of approximately 100 nm, and the SiO2 shell was fully coated on the surface of the core. On the basis of these results, the effect of SiO2 content on the thickness of the synthesized composites and microstructure, as well as the electrical properties of the ZnO varistors sintered in air at 1150°C for 2 h, were fully studied. In particular, the ZnO varistor prepared with the appropriate amount of the SiO2 coating (˜40 nm) leads to a superior electrical performance with the high breakdown voltage of 418 V mm-1 and an excellent nonlinear coefficient of 70.7, compared with the varistors obtained without the SiO2 coating. The high performance is attributed to the smaller and more homogeneous ZnO grains obtained via the SiO2 coating.

  8. Synthesis of SiO2-Coated Core-Shell ZnO Composites for Preparing High-Voltage Varistors

    Science.gov (United States)

    Qu, Xiao; Yao, Da-Chuan; Liu, Jin-Ran; Wang, Mao-Hua; Zhang, Han-Ping

    2018-01-01

    Monodispersed ZnO composite microspheres were successfully prepared by a facile ultrasound irradiation method. Then, the uniform core-shell structured composites were synthesized through the hydrolysis of tetraethyl orthosilicate on the surface of the ZnO composite microspheres. Microstructural studies of the as-obtained powders were carried out using the techniques of the x-ray powder diffraction, field emission scanning electron microscopy and transmission electron microscopy with energy dispersive x-ray spectroscopy. The results show that the pink ZnO composite powders as the core were spherical structures with the size of approximately 100 nm, and the SiO2 shell was fully coated on the surface of the core. On the basis of these results, the effect of SiO2 content on the thickness of the synthesized composites and microstructure, as well as the electrical properties of the ZnO varistors sintered in air at 1150°C for 2 h, were fully studied. In particular, the ZnO varistor prepared with the appropriate amount of the SiO2 coating (˜40 nm) leads to a superior electrical performance with the high breakdown voltage of 418 V mm-1 and an excellent nonlinear coefficient of 70.7, compared with the varistors obtained without the SiO2 coating. The high performance is attributed to the smaller and more homogeneous ZnO grains obtained via the SiO2 coating.

  9. Development of Zn-Al-Cu coatings by hot dip coated technology: preparation and characterization; Obtencion y caracterizacion de recubrimientos Zn-Al-Cu por inmersion en caliente sobre aceros de bajo carbono

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes, J.; Barba, A.; Hernandez, M. A.; Salas, J.; Espinoza, J. L.; Denova, C.; Torres-Villasenor, G.; Conde, A.; Covelo, A.; Valdez, R.

    2013-07-01

    In the present study, research concerning Zn-Al-Cu coatings on low carbon steels has been conducted in order to characterize different properties obtained by a hot-dip coated process. The results include preparation procedure as well as the processing parameters of the coatings. The obtained coatings were subjected to a cold rolling process followed by an anneal heat treatment at different temperatures and under different time conditions. The structural characteristics of coatings have been investigated by optical and electron microscopy. The mechanical properties were obtained by using micro-hardness testing, deep drawing and wear tests whereas chemical analyses were carried out using the SEM/EDAX microprobe. The corrosion properties were achieved by using a salt spray fog chamber and potentiodynamic tests in a saline solution. The coatings are resistant to corrosion and wear in the presence of sodium chloride, therefore, the coatings could be an attractive alternative for application in coastal areas, and adequate wear adhesive resistance. (Author)

  10. Fe-based soft magnetic composites coated with NiZn ferrite prepared by a co-precipitation method

    Science.gov (United States)

    Peng, Yuandong; Yi, Yi; Li, Liya; Ai, Hengyu; Wang, Xiaoxu; Chen, Lulu

    2017-04-01

    Fe powder was coated with NiZn ferrite by a co-precipitation method using chlorate as the raw material. Soft magnetic composites were manufactured via compaction and heat treatment of the coated powder. The coated powder and heat treated powder were analysed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy. Their magnetic properties were determined using a Quantum Design-Vibrating Sample Magnetometer (QD-VSM). The composites were analysed with SEM and EDS. The permeability and magnetic loss of the composites were measured with a B-H curve analyzer. The results show that, using the co-precipitation method, the raw precipitate was successfully prepared and coated the pure Fe powder and turned into spinel NiZn ferrite treated at 600 ℃ for 1 h. After heat treatment at 500 ℃ under air, the insulation coating layer of soft magnetic composite (SMC) was not destroyed and containing Fe, Ni, Zn and oxygen. The permeabilities of the SMC are stable at edge of the 2-200 kHz frequency range and the total loss was lower.

  11. Taking a bite out of "Buffy": Carnivalesque play and resistance in fan fiction

    Directory of Open Access Journals (Sweden)

    Amanda L. Hodges

    2011-09-01

    Full Text Available Popular culture provides a vital point of entry to examine discourses of hegemony and resistance at work within the growing culture of fandom. Drawing from epistemologies of feminism and poststructuralism, we deconstruct how fans read, co-construct, apply, and reenvision texts as they navigate societal notions of gender in their own constructions of subjectivity. We discuss subversive examples of sexuality and gender found in American popular culture, particularly the portrayal of femininity in the character of Faith, the bad girl from Buffy the Vampire Slayer. Such examples are important because they impart crucial hegemonic lessons that may then be played out in everyday life. By focusing on the third season of Buffy the Vampire Slayer, we examine the discourses of risk at play within the source text, fan sites, and online fan fiction. Bakhtin's ideas of carnival drive much of fan fiction, and Foucault's analysis of power relations as well as Butler's theories of performativity contribute to play that affords dynamic, critical perspectives with which to interrogate social metanarratives and their impact on the subject.

  12. A high performance ceria based interdiffusion barrier layer prepared by spin-coating

    DEFF Research Database (Denmark)

    Plonczak, Pawel; Joost, Mario; Hjelm, Johan

    2011-01-01

    . The decomposition of the polymer precursor used in the spin-coating process was studied. The depositions were performed on anode supported half cells. By controlling the sintering temperature between each spin-coating process, dense and crack-free CGO films with a thickness of approximately 1 μm were obtained...

  13. Durable hydrophobic coating composition for metallic surfaces and method for the preparation of the composition

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiong

    2017-02-14

    A durable hydrophobic coating composition containing fluorinated silanes for metallic surfaces, such as stainless steel surfaces. The composition includes at least one fluorine-containing silane compound, at least one phosphorus-containing silane compound, and at least one hydrolysable compound. This coating is suitable for condenser tubes, among other applications, to promote dropwise condensation.

  14. Polydimethylsiloxane microspheres with poly(methyl methacrylate) coating: Modelling, preparation, and characterization

    DEFF Research Database (Denmark)

    Ma, Baoguang; Hansen, Jens Henrik; Hvilsted, Søren

    2015-01-01

    functional PDMS microspheres were coated with poly(methyl methacrylate) (PMMA) by spin coating with different concentrations of PMMA solutions. The quality of the resulting PMMA shell is investigated using rheological measurements at 50 8C with a timesweep procedure. The results strongly suggest that PMMA...

  15. Effects of Organic Compounds on Microstructure, Optical, and Electrical Properties of ITO Thin Films Prepared by Dip-Coating Method

    Directory of Open Access Journals (Sweden)

    Ru-Yuan Yang

    2012-01-01

    Full Text Available Tin-doped Indium oxide (ITO thin films were prepared by sol-gel dip-coating technique using low-cost metal salts and organic solvents. The coated films were treated without annealing or annealed at 400°C and 600°C in 3% H2/97% N2 mixtures atmosphere. Microstructure, optical, and electrical properties of the prepared ITO films were investigated in detail. The maximum transmittance in the visible range (380–780 nm is 85.6%, and the best resistivity is 5×10−2 Ω-cm when annealed at 600°C in 3% H2/97% N2 mixtures atmosphere. It is found that the optical and electrical properties of the prepared ITO films are strongly related to the microstructure variation. The organic compounds could not be removed completely, and the prepared ITO thin films were not dense when the prepared ITO film was annealed at 600°C in 3% H2/97% N2 mixtures atmosphere, causing the poor conductivity.

  16. Preparation of biodegradable magnetic microspheres with poly(lactic acid)-coated magnetite

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Hong; Saatchi, Katayoun [Faculty of Pharmaceutical Sciences, University of British Columbia, 2146 East Mall, Vancouver, BC, 6T 1Z3 (Canada); Haefeli, Urs O. [Faculty of Pharmaceutical Sciences, University of British Columbia, 2146 East Mall, Vancouver, BC, V6T 1Z3 (Canada)], E-mail: uhafeli@interchange.ubc.ca

    2009-05-15

    Poly(lactic acid) (PLA)-coated magnetic nanoparticles were made using uncapped PLA with free carboxylate groups. The physical properties of these particles were compared to those of oleate-coated or oleate/sulphonate bilayer (W40) coated magnetic particles. Magnetic microspheres (MMS) with the matrix material poly(lactide-co-glycolide) (PLGA) or PLA were then formed by the emulsion solvent extraction method with encapsulation efficiencies of 40%, 83% and 96% for oleate, PLA and oleate/sulfonate-coated magnetic particles, respectively. MMS made from PLA-coated magnetite were hemocompatible and produced no hemolysis, whereas the other MMS were hemolytic above 0.3 mg/mL of blood.

  17. Preparation and magnetic properties of nano-Ni coated cenosphere composites

    Science.gov (United States)

    Meng, Xian-feng; Li, Dong-hong; Shen, Xiang-qian; Liu, Wei

    2010-04-01

    Ni coated cenosphere composites are successfully fabricated by heterogeneous precipitation method using metal salts, ammonium hydro-carbonate and cenospheres as the raw materials. The cenosphere particles are characterized by scanning electron microscope (SEM)/energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) during and after the coating process. All results show that relatively uniform, smooth and compact Ni layer has been successfully coated onto cenospheres under the given conditions, furthermore, the nanometer Ni crystallite has a face-centered cubic structure. Magnetic property of Ni coated cenosphere composites can be adjusted by controlling the synthesis conditions and content of magnetic metal. The low density Ni coated cenosphere composites may be utilized for electromagnetic wave shielding and microwave absorbing materials.

  18. Preparation of Lanthanum Zirconate Coatings by the Solution Precursor Plasma Spray

    Science.gov (United States)

    Wang, W. Z.; Coyle, T.; Zhao, D.

    2014-06-01

    Solution precursor plasma spray (SPPS) can synthesize powders and deposit the coatings synchronously. The lanthanum zirconate coatings are deposited by SPPS in the present study, and the dense coating can be obtained through changing the precursor solution. The addition of urea can change the heat exchange process for some precursor mixtures. However, almost no effect can be found on the microstructure of powder and coating by the addition of urea. The extra heat energy caused by the addition of urea is so small, as compared with the heat input by the present plasma jet, so that the heating effect can be ignored. The porosity of coatings increase when the LaCl3·7H2O instead of La(NO3)3·6H2O reacts with Zr(CH3CO2)4.

  19. Porous niobium coatings fabricated with selective laser melting on titanium substrates: Preparation, characterization, and cell behavior

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Sheng [Science and Technology on Power Beam Processes Laboratory, Beijing Aeronautical Manufacturing Technology Research Institute (BAMTRI), Beijing 100024 (China); State Key Lab of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Cheng, Xian; Yao, Yao; Wei, Yehui [Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Han, Changjun; Shi, Yusheng [State Key Lab of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Wei, Qingsong, E-mail: wqs_xn@163.com [State Key Lab of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhang, Zhen, E-mail: zhangzhentitanium@163.com [State Key Lab of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China)

    2015-08-01

    Nb, an expensive and refractory element with good wear resistance and biocompatibility, is gaining more attention as a new metallic biomaterial. However, the high price of the raw material, as well as the high manufacturing costs because of Nb's strong oxygen affinity and high melting point have limited the widespread use of Nb and its compounds. To overcome these disadvantages, porous Nb coatings of various thicknesses were fabricated on Ti substrate via selective laser melting (SLM), which is a 3D printing technique that uses computer-controlled high-power laser to melt the metal. The morphology and microstructure of the porous Nb coatings, which had pores ranging from 15 to 50 μm in size, were characterized with scanning electron microscopy (SEM). The average hardness of the coating, which was measured with the linear intercept method, was 392 ± 37 HV. In vitro tests of the porous Nb coating which was monitored with SEM, immunofluorescence, and CCK-8 counts of cells, exhibited excellent cell morphology, attachment, and growth. The simulated body fluid test also proved the bioactivity of the Nb coating. Therefore, these new porous Nb coatings could potentially be used for enhanced early biological fixation to bone tissue. In addition, this study has shown that SLM technique could be used to fabricate coatings with individually tailored shapes and/or porosities from group IVB and VB biomedical metals and their alloys on stainless steel, Co–Cr, and other traditional biomedical materials without wasting raw materials. - Highlights: • Porous Nb coating was firstly fabricated on Ti substrate by SLM technique. • Morphology, microstructure and hardness of the coating were characterized. • In vitro test of the coating showed good cell attachment, morphology and growth.

  20. Deposition parameters to improve the fouling-release properties of thin siloxane coatings prepared by PACVD

    Science.gov (United States)

    Akesso, Laurent; Navabpour, Parnia; Teer, Dennis; Pettitt, Michala E.; Callow, Maureen E.; Liu, Chen; Su, Xueju; Wang, Su; Zhao, Qi; Donik, Crtomir; Kocijan, Aleksandra; Jenko, Monika; Callow, James A.

    2009-04-01

    A range of SiO x-like coatings was deposited on glass slides from a hexamethylsiloxane precursor by plasma-assisted CVD. The effect of varying deposition parameters, specifically ion cleaning time and HMDSO/O 2 ratios, on the coating properties and antifouling performance was investigated. At low HMDSO/O 2 ratios, the resulting coatings were close to SiO 2. Carbon content in the bulk of the coatings increased with increasing HMDSO/O 2 ratio. Coatings deposited at high HMDSO/O 2 ratios and with the longest cleaning time (30 min), elevated the relative carbon content to 25 atomic %. Surface energies (22-43 mJ/m) were correlated with the degree of surface oxidation and hydrocarbon content. With the exception of the most polar coatings the apolar component of the surface energy ( γLW) was the dominant component. In the most hydrophilic coatings, the Lewis base component of the surface energy ( γ-) was dominant. Significantly improved antifouling performance was detected with the most reduced coatings deposited using the extended ion cleaning times. For both, the removal of sporelings of the marine green alga, Ulvalinza and the initial adhesion of the freshwater bacterium, Pseudomonas fluorescens, there was a strong, positive correlation between strength of attachment and ion cleaning time. Increased ion cleaning time will elevate the deposition temperature, increasing decomposition rates and thus the crosslinking of the polymer. Increased cross-linking may render these coatings less permeable to penetration and mechanical interlocking by the adhesive polymers used by these organisms, thus reducing their adhesion. Films with improved biological performance have potential for use as coatings in the control of biofouling in applications such as heat exchangers, where thin films are important for effective thermal transfer, or optical windows where transparency is important.

  1. Preparation and performance evaluation of epoxy-based heat reflective coating for the pavement

    Science.gov (United States)

    Hu, B.; Liang, Y. H.; Guo, L. Y.; Jiang, T.

    2017-04-01

    According to the basic characteristics and composition of heat-reflective coating, combining with the functional requirements of road materials, the experiment selects the epoxy resin with good wear resistance and adhesive force as a film forming material, with TiO2, SiO2 and extinction powder as the main functional filler. The experiment gets a good formula with suitable viscosity, low glossiness and good cooling effect, optimizes by orthogonal experiment. The experiment evaluates the indoor and outdoor cooling effect of heat-reflective coating, and analyses the road performance of the coating. The results shows that the better heat-reflective coating formula included 12% of titanium dioxide, 4% of silica and 4% of extinction powder. When the dosage of coating is 0.8kg/m2, the indoor specimen of heat-reflective coating decrease the temperature of 12 ∼ 14°C, and the specimen under solar radiation can reduce the temperature of 7 ∼ 9°C. The pavement of heat-reflective coating has good wear resistance, but the road slip resistance partly declines. Therefore, it needs to add the anti-sliding particles to meet the safe driving requirements.

  2. Evaluation of the quality of blood components prepared using the Reveos automated blood processing system.

    Science.gov (United States)

    Johnson, L; Winter, K M; Kwok, M; Reid, S; Marks, D C

    2013-10-01

    The Reveos automated blood processing system has been developed to combine primary and secondary processing of whole-blood units, resulting in a plasma unit, a red-blood-cell concentrate and an interim platelet unit per input. The aim of this study was to determine product specifications and in vitro quality of components produced by the Reveos system. Whole blood was processed using the Reveos system and compared with historical Reference units produced using semi-automated methods. Reveos red cells were leucoreduced and stored in SAGM at 4°C. Reveos plasma was frozen at -30°C and factor activity was assessed after thawing. Reference red cell, plasma and buffy coats were produced by top and bottom processing. Leucoreduced Reveos and Reference platelet concentrates were prepared by pooling four interim platelet units or four buffy coats, respectively, with SSP+. Processing with the Reveos system was faster (76 min) than semi-automated separation (92 min). The red cell and platelet yields were higher in the units prepared by the Reveos system. The Reference and Reveos red cell and plasma units had very similar in vitro quality parameters. The platelet concentrates were also similar in many in vitro parameters, including pH, glucose and lactate metabolism, hypotonic shock response and phosphatidylserine expression, although platelet activation markers (CD62P and cytokine levels) were higher in the Reveos units. The Reveos system can improve blood component efficiencies through reductions in processing time, whilst maintaining similar component quality. Vox Sanguinis © 2013 International Society of Blood Transfusion.

  3. Properties and structure of coatings from PG-SR powders prepared by a plasma method

    Science.gov (United States)

    Demidov, V. G.

    1998-08-01

    In recent years, a plasma method for obtaining coatings with the use of a controlled electric arc instead of an uncontrolled welding arc has found wide application in various branches of industry. The Laboratory of Materials Science at the Institute of Coal of the Siberian Branch of the Russian Academy of Sciences is working on the possibility of using plasma strengthening coatings for increasing the wear resistance of parts of mining equipment. A whole spectrum of coated parts for hydraulic supports and the equipment of concentration plants with an increased service life and wear resistance has been suggested.

  4. Corrigendum to "Preparation of Nafion-sulfonated clay nanocomposite membrane for direct menthol fuel cells via a film coating process" [J. Power Sources 165 (2007) 1-2

    Science.gov (United States)

    Kim, Tae Kyoung; Kang, Myeongsoon; Choi, Yeong Suk; Kim, Hae Kyung; Lee, Wonmok; Chang, Hyuk; Seung, Doyoung

    The author regrets that the above paper was printed with an error in the title. The correct title reads: "Preparation of Nafion-sulfonated clay nanocomposite membrane for direct methanol fuel cells via a film coating process".

  5. Overexpression of Buffy enhances the loss of parkin and suppresses the loss of Pink1 phenotypes in Drosophila.

    Science.gov (United States)

    M'Angale, P Githure; Staveley, Brian E

    2017-03-01

    Mutations in parkin (PARK2) and Pink1 (PARK6) are responsible for autosomal recessive forms of early onset Parkinson's disease (PD). Attributed to the failure of neurons to clear dysfunctional mitochondria, loss of gene expression leads to loss of nigrostriatal neurons. The Pink1/parkin pathway plays a role in the quality control mechanism aimed at eliminating defective mitochondria, and the failure of this mechanism results in a reduced lifespan and impaired locomotor ability, among other phenotypes. Inhibition of parkin or Pink1 through the induction of stable RNAi transgene in the Ddc-Gal4-expressing neurons results in such phenotypes to model PD. To further evaluate the effects of the overexpression of the Bcl-2 homologue Buffy, we analysed lifespan and climbing ability in both parkin-RNAi- and Pink1-RNAi-expressing flies. In addition, the effect of Buffy overexpression upon parkin-induced developmental eye defects was examined through GMR-Gal4-dependent expression. Curiously, Buffy overexpression produced very different effects: the parkin-induced phenotypes were enhanced, whereas the Pink1-enhanced phenotypes were suppressed. Interestingly, the overexpression of Buffy along with the inhibition of parkin in the neuron-rich eye results in the suppression of the developmental eye defects.

  6. Preparation and self-sterilizing properties of Ag@TiO2-styrene-acrylic complex coatings.

    Science.gov (United States)

    Zhou, Xiang-dong; Chen, Feng; Yang, Jin-tao; Yan, Xiao-hui; Zhong, Ming-qiang

    2013-04-01

    In this study, we report a simple and cost-effective method for self-sterilized complex coatings obtained by Ag@TiO2 particle incorporation into styrene-acrylic latex. The Ag@TiO2 particles were prepared via a coupling agent modification process. The composite latices characterized by transmission electron microscopy (TEM) study were highly homogeneous at the nanometric scale, and the Ag@TiO2 particles were well dispersed and exhibited an intimate contact between both the organic and inorganic components. The Ag@TiO2 nanoparticles significantly enhanced the absorption in the visible region and engendered a good heat-insulating effect of the complex coatings. Moreover, the Ag@TiO2 nanoparticle incorporation into this polymer matrix renders self-sterilized nanocomposite materials upon light excitation, which are tested against Escherichia coli and Staphylococcus aureus. The complex coatings display an impressive performance in the killing of all micro-organisms with a maximum for a Ag@TiO2 loading concentration of 2-5 wt.%. The weathering endurance of the complex coating was also measured. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Feasibility of preparing patterned molybdenum coatings on bismuth telluride thermoelectric modules.

    Energy Technology Data Exchange (ETDEWEB)

    Sarobol, Pylin; Hall, Aaron Christopher; Miller, Stephen Samuel; Knight, Marlene E.; LePage, William S.; Sobczak, Catherine Elizabeth.; Wesolowski, Daniel Edward

    2013-09-01

    Molybdenum electrical interconnects for thermoelectric modules were produced by air plasma spraying a 30%CE%BCm size molybdenum powder through a laser-cut Kapton tape mask. Initial feasibility demonstrations showed that the molybdenum coating exhibited excellent feature and spacing retention (~170%CE%BCm), adhered to bismuth-telluride, and exhibited electrical conductivity appropriate for use as a thermoelectric module interconnect. A design of experiments approach was used to optimize air plasma spray process conditions to produce a molybdenum coating with low electrical resistivity. Finally, a molybdenum coating was successfully produced on a fullscale thermoelectric module. After the addition of a final titanium/gold layer deposited on top of the molybdenum coating, the full scale module exhibited an electrical resistivity of 128%CE%A9, approaching the theoretical resistivity value for the 6mm module leg of 112%CE%A9. Importantly, air plasma sprayed molybdenum did not show significant chemical reaction with bismuth-telluride substrate at the coating/substrate interface. The molybdenum coating microstructure consisted of lamellar splats containing columnar grains. Air plasma sprayed molybdenum embedded deeply (several microns) into the bismuth-telluride substrate, leading to good adhesion between the coating and the substrate. Clusters of round pores (and cracks radiating from the pores) were found immediately beneath the molybdenum coating. These pores are believed to result from tellurium vaporization during the spray process where the molten molybdenum droplets (2623%C2%B0C) transferred their heat of solidification to the substrate at the moment of impact. Substrate cooling during the molybdenum deposition process was recommended to mitigate tellurium vaporization in future studies.

  8. Preparation and characterization of PVPI-coated Fe3O4 nanoparticles as an MRI contrast agent

    Science.gov (United States)

    Wang, Guangshuo; Chang, Ying; Wang, Ling; Wei, Zhiyong; Kang, Jianyun; Sang, Lin; Dong, Xufeng; Chen, Guangyi; Wang, Hong; Qi, Min

    2013-08-01

    Polyvinylpyrrolidone-iodine (PVPI)-coated Fe3O4 nanoparticles were prepared by using inverse chemical co-precipitation method, in which the PVPI serves as a stabilizer and dispersant. The wide angle X-ray diffraction (WAXD) and selected area electron diffraction (SAED) results showed that the inverse spinel structure pure phase polycrystalline Fe3O4 was obtained. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results exhibited that the resulted Fe3O4 nanoparticles were roughly spherical in shape with narrow size distribution and homogenous shape. Fourier transform infrared spectroscopy (FTIR) results suggested that PVPI interacted with Fe3O4 via its carbonyl groups. Results of superconducting quantum interference device (SQUID) indicated prepared Fe3O4 nanoparticles exhibited superparamagnetic behavior and high saturation magnetization. T2-weighted MRI images of PVPI-coated Fe3O4 nanoparticles showed that the magnetic resonance signal was enhanced significantly with increasing nanoparticles concentration in water at room temperature. These results indicated that the PVPI-coated Fe3O4 nanoparticles had great potential for application in MRI as a T2 contrast agent.

  9. Preparation and application of a coated-fiber needle extraction device.

    Science.gov (United States)

    Lou, Dawei; Chen, Huijun; Wang, Xiyue; Lian, Lili; Zhu, Bo; Yang, Qiaoling; Guo, Tingxiu; Li, Qiuying; Wang, Runnan; Guo, Xiaoyang

    2016-10-01

    In this study, a needle-trap device with fibers coated with a molecularly imprinted polymer was developed for separation. A number of heat-resistant Zylon filaments were longitudinally packed into a glass capillary, followed by coating with a molecularly imprinted polymer. Then, the molecularly imprinted polymer coating was copolymerized and anchored onto the surface of the fibers. The bundle of synthetic fibers coated with the molecularly imprinted polymer was packed into a 21G stainless-steel needle and served as an extraction medium. The coated-fiber needle extraction device was used to extract volatile organic compounds from paints and gasoline effectively. Subsequently, the extracted volatile organic compounds were analyzed by gas chromatography. Calibration curves of gaseous benzene, toluene, ethylbenzene, and o-xylene in the concentration range of 1-250 μg/L were obtained to evaluate the method, acceptable linearity was attended with correlation coefficients above 0.998. The limit of detection of benzene, toluene, ethylbenzene, and o-xylene was 11-20 ng/L using the coated-fiber needle-trap device. The relative standard deviation of needle-to-needle repeatability was less than 8% with an extraction time of 20 min. The loss rates after storage for 3 and 7 days at room temperature were less than 30%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Underwater Superoleophobic Surfaces Prepared from Polymer Zwitterion/Dopamine Composite Coatings.

    Science.gov (United States)

    Chang, Chia-Chih; Kolewe, Kristopher W; Li, Yinyong; Kosif, Irem; Freeman, Benny D; Carter, Kenneth R; Schiffman, Jessica D; Emrick, Todd

    2016-03-23

    Hydration is central to mitigating surface fouling by oil and microorganisms. Immobilization of hydrophilic polymers on surfaces promotes retention of water and a reduction of direct interactions with potential foulants. While conventional surface modification techniques are surface-specific, mussel-inspired adhesives based on dopamine effectively coat many types of surfaces and thus hold potential as a universal solution to surface modification. Here, we describe a facile, one-step surface modification strategy that affords hydrophilic, and underwater superoleophobic, coatings by the simultaneous deposition of polydopamine (PDA) with poly(methacryloyloxyethyl phosphorylcholine) (polyMPC). The resultant composite coating features enhanced hydrophilicity (i.e., water contact angle of ~10° in air) and antifouling performance relative to PDA coatings. PolyMPC affords control over coating thickness and surface roughness, and results in a nearly 10 fold reduction in Escherichia coli adhesion relative to unmodified glass. The substrate-independent nature of PDA coatings further promotes facile surface modification without tedious surface pretreatment, and offers a robust template for codepositing polyMPC to enhance biocompatibility, hydrophilicity and fouling resistance.

  11. A loss of Pdxk model of Parkinson disease in Drosophila can be suppressed by Buffy.

    Science.gov (United States)

    M'Angale, P Githure; Staveley, Brian E

    2017-06-12

    The identification of a DNA variant in pyridoxal kinase (Pdxk) associated with increased risk to Parkinson disease (PD) gene led us to study the inhibition of this gene in the Dopa decarboxylase (Ddc)-expressing neurons of the well-studied model organism Drosophila melanogaster. The multitude of biological functions attributable to the vitamers catalysed by this kinase reveal an overabundance of possible links to PD, that include dopamine synthesis, antioxidant activity and mitochondrial function. Drosophila possesses a single homologue of Pdxk and we used RNA interference to inhibit the activity of this kinase in the Ddc-Gal4-expressing neurons. We further investigated any association between this enhanced disease risk gene with the established PD model induced by expression of α-synuclein in the same neurons. We relied on the pro-survival functions of Buffy, an anti-apoptotic Bcl-2 homologue, to rescue the Pdxk-induced phenotypes. To drive the expression of Pdxk RNA interference in DA neurons of Drosophila, we used Ddc-Gal4 which drives expression in both dopaminergic and serotonergic neurons, to result in decreased longevity and compromised climbing ability, phenotypes that are strongly associated with Drosophila models of PD. The inhibition of Pdxk in the α-synuclein-induced Drosophila model of PD did not alter longevity and climbing ability of these flies. It has been previously shown that deficiency in vitamers lead to mitochondrial dysfunction and neuronal decay, therefore, co-expression of Pdxk-RNAi with the sole pro-survival Bcl-2 homologue Buffy in the Ddc-Gal4-expressing neurons, resulted in increased survival and a restored climbing ability. In a similar manner, when we inhibited Pdxk in the developing eye using GMR-Gal4, we found that there was a decrease in the number of ommatidia and the disruption of the ommatidial array was more pronounced. When Pdxk was inhibited with the α-synuclein-induced developmental eye defects, the eye phenotypes were

  12. Loss of porin function in dopaminergic neurons of Drosophila is suppressed by Buffy.

    Science.gov (United States)

    M'Angale, P Githure; Staveley, Brian E

    2016-11-24

    Mitochondrial porin, also known as the voltage-dependent anion channel (VDAC), is a multi-functional channel protein that shuttles metabolites between the mitochondria and the cytosol and implicated in cellular life and death decisions. The inhibition of porin under the control of neuronal Ddc-Gal4 result in short lifespan and in an age-dependent loss in locomotor function, phenotypes that are strongly associated with Drosophila models of Parkinson disease. Loss of porin function was achieved through exploitation of RNA interference while derivative lines were generated by homologous recombination and tested by PCR. The UAS/Gal4 expression system was exploited with directed expression in neurons achieved with the use of the Dopa decarboxylase and in the developing eye with the Glass multiple reporter transgenes. Statistical analyses for ageing assay employed Log rank (Mantel-Cox) test, climbing indices were fitted with a non-linear curve and confidence intervals compared at 95%. Biometric analysis of the eye phenotypes was obtained by unpaired student T-test. The expression of α-synuclein in neuronal populations that include dopamine producing neurons under the control of Ddc-Gal4 produces a robust Parkinson disease model, and results in severely reduced lifespan and locomotor dysfunction. In addition, the porin-induced phenotypes are greatly suppressed when the pro-survival Bcl-2 homologue Buffy is overexpressed in these neurons and in the developing eye adding to the cellular advantages of altered expression of this anti-apoptotic gene. When we co-expressed α-synuclein along with porin, it results in a decrease in lifespan and impaired climbing ability. This enhancement of the α-synuclein-induced phenotypes observed in neurons was demonstrated in the neuron rich eye, where the simultaneous co-expression of porin-RNAi and α-synuclein resulted in an enhanced eye phenotype, marked by reduced number of ommatidia and increased disarray of the ommatidia. The

  13. Preparation of Chitosan Coated Magnetic Hydroxyapatite Nanoparticles and Application for Adsorption of Reactive Blue 19 and Ni2+ Ions

    Directory of Open Access Journals (Sweden)

    Van Cuong Nguyen

    2014-01-01

    Full Text Available An adsorbent called chitosan coated magnetic hydroxyapatite nanoparticles (CS-MHAP was prepared with the purpose of improvement for the removal of Ni2+ ions and textile dye by coprecipitation. Structure and properties of CS-MHAP were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, and vibrating sample magnetometer (VSM. Weight percent of chitosan was investigated by thermal gravimetric analysis (TGA. The prepared CS-MHAP presents a significant improvement on the removal efficiency of Ni2+ ions and reactive blue 19 dye (RB19 in comparison with chitosan and magnetic hydroxyapatite nanoparticles. Moreover, the adsorption capacities were affected by several parameters such as contact time, initial concentration, adsorbent dosage, and initial pH. Interestingly, the prepared adsorbent could be easily recycled from an aqueous solution by an external magnet and reused for adsorption with high removal efficiency.

  14. Tribological performance of an H-DLC coating prepared by PECVD

    Energy Technology Data Exchange (ETDEWEB)

    Solis, J., E-mail: jsolis@ittla.edu.mx [IFS, University of Leeds, School of Mechanical Engineering, Leeds, LS2 9JT (United Kingdom); SEP/SES/TecNM/IT de Tlalnepantla, DEPI-Mechanical Engineering, 54070, Edo. Méx. (Mexico); Zhao, H.; Wang, C. [IFS, University of Leeds, School of Mechanical Engineering, Leeds, LS2 9JT (United Kingdom); Verduzco, J.A. [Instituto de Investigación en Metalurgia y Materiales, UMSNH, P.O. Box 888, 58000, Morelia, Mich. (Mexico); Bueno, A.S. [IFS, University of Leeds, School of Mechanical Engineering, Leeds, LS2 9JT (United Kingdom); Mechanical Engineering Department, Universidade Federal de São João Del Rei, 170 Praça Frei Orlando, 36307-352 São João Del Rei (Brazil); Neville, A. [IFS, University of Leeds, School of Mechanical Engineering, Leeds, LS2 9JT (United Kingdom)

    2016-10-15

    Highlights: • Duplex hydrogenated Diamond-like Carbon was produced and characterised. • Friction and wear under dry condition of H-DLC/steel tribopair was assessed. • Adhesive strength of the coating was 80N after the scratch tests under dry condition. • Maximum and minimum values of average coefficient of friction were 0.21 and 0.13. • A protective transferred layer on the counterpart produced a carbon-carbon contact. - Abstract: Carbon-based coatings are of wide interest due to their application in machine elements subjected to continuous contact where fluid lubricant films are not permitted. This paper describes the tribological performance under dry conditions of duplex layered H-DLC coating sequentially deposited by microwave excited plasma enhanced chemical vapour deposition on AISI 52100 steel. The architecture of the coating comprised Cr, WC, and DLC (a-C:H) with a total thickness of 2.8 μm and compressive residual stress very close to 1 GPa. Surface hardness was approximately 22 GPa and its reduced elastic modulus around 180 GPa. Scratch tests indicated a well adhered coating achieving a critical load of 80 N. The effect of normal load on the friction and wear behaviours were investigated with steel pins sliding against the actual coating under dry conditions at room temperature (20 ± 2 °C) and 35–50% RH. The results show that coefficient of friction of the coating decreased from 0.21 to 0.13 values with the increase in the applied loads (10–50 N). Specific wear rates of the surface coating also decrease with the increase in the same range of applied loads. Maximum and minimum values were 14 × 10{sup −8} and 5.5 × 10{sup −8} mm{sup −3}/N m, respectively. Through Raman spectroscopy and electron microscopy it was confirmed the carbon-carbon contact, due to the tribolayer formation on the wear scars of the coating and pin. In order to further corroborate the experimental observations regarding the graphitisation behaviour, the

  15. Kinetic Effects on Self-Assembly and Function of Protein-Polymer Bioconjugates in Thin Films Prepared by Flow Coating

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Dongsook [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA; Huang, Aaron [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA; Olsen, Bradley D. [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA

    2016-11-04

    The self-assembly of nanostructured globular protein arrays in thin films is demonstrated using protein–polymer block copolymers based on a model protein mCherry and the polymer poly(oligoethylene glycol acrylate) (POEGA). Conjugates are flow coated into thin films on a poly(ethylene oxide) grafted Si surface, forming self-assembled cylindrical nanostructures with POEGA domains selectively segregating to the air–film interface. Long-range order and preferential arrangement of parallel cylinders templated by selective surfaces are demonstrated by controlling relative humidity. Long-range order increases with coating speed when the film thicknesses are kept constant, due to reduced nucleation per unit area of drying film. Fluorescence emission spectra of mCherry in films prepared at <25% relative humidity shows a small shift suggesting that proteins are more perturbed at low humidity than high humidity or the solution state.

  16. Porous niobium coatings fabricated with selective laser melting on titanium substrates: Preparation, characterization, and cell behavior.

    Science.gov (United States)

    Zhang, Sheng; Cheng, Xian; Yao, Yao; Wei, Yehui; Han, Changjun; Shi, Yusheng; Wei, Qingsong; Zhang, Zhen

    2015-08-01

    Nb, an expensive and refractory element with good wear resistance and biocompatibility, is gaining more attention as a new metallic biomaterial. However, the high price of the raw material, as well as the high manufacturing costs because of Nb's strong oxygen affinity and high melting point have limited the widespread use of Nb and its compounds. To overcome these disadvantages, porous Nb coatings of various thicknesses were fabricated on Ti substrate via selective laser melting (SLM), which is a 3D printing technique that uses computer-controlled high-power laser to melt the metal. The morphology and microstructure of the porous Nb coatings, which had pores ranging from 15 to 50 μm in size, were characterized with scanning electron microscopy (SEM). The average hardness of the coating, which was measured with the linear intercept method, was 392±37 HV. In vitro tests of the porous Nb coating which was monitored with SEM, immunofluorescence, and CCK-8 counts of cells, exhibited excellent cell morphology, attachment, and growth. The simulated body fluid test also proved the bioactivity of the Nb coating. Therefore, these new porous Nb coatings could potentially be used for enhanced early biological fixation to bone tissue. In addition, this study has shown that SLM technique could be used to fabricate coatings with individually tailored shapes and/or porosities from group IVB and VB biomedical metals and their alloys on stainless steel, Co-Cr, and other traditional biomedical materials without wasting raw materials. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Preparation and properties of nanophase (Ce, Zr, PrO2-doped alumina coating on cordierite ceramic honeycomb for three-way catalysts

    Directory of Open Access Journals (Sweden)

    Jiuying Tian

    2012-03-01

    Full Text Available Nanophase (Ce, Zr, PrO2-doped alumina coatings were prepared by impregnating the cordierite ceramic honeycomb in the sol or in the slurry of already calcined powder, respectively. The effects of preparation methods on the crystal phase, texture, oxygen storage capacity (OSC, reducibility, surface morphology and thermal stability of coatings were investigated by X-ray diffraction (XRD, the Brunauer Emmet Teller (BET method, the oxygen pulsing technique, H2-temperature-programmed reduction (H2-TPR and scanning electron microscopy (SEM. These nanophase (Ce, Zr, PrO2-doped alumina coatings were used as supports to prepare Pd-only three-way catalysts, and evaluated with respect to catalytic activities. The results indicate that the nanophase (Ce, Zr, PrO2-doped alumina coatings prepared by the two methods have high thermal stability. However, the coating derived from the sol shows better crystalline structure, texture, reducibility and oxygen storage capacity than the coating derived from the slurry. SEM observation shows that the morphology of the coating derived from the sol is uniform and smooth. The Pd-only catalyst derived from the sol exhibits high three-way catalytic activity at low temperature and thermal stability, suggesting a great potential for applications.

  18. Synthesis, Properties and Application of Glucose Coated Fe3O4 Nanoparticles Prepared by Co-precipitation Method

    Science.gov (United States)

    Sari, Ayu Y.; Eko, A. S.; Candra, K.; Hasibuan, Denny P.; Ginting, M.; Sebayang, P.; Simamora, P.

    2017-07-01

    Synthesis of glucose coated Fe3O4 magnetic nanoparticles have been successfully prepared with co-precipitation method. Raw material of natural iron-sand was obtained from Buaya River, Deliserdang, Indonesia. The milled iron-sand was dissolved in HCl (37 mole %), and stirred in 300 rpm at 70°C for 90 minutes. Glucose was added to the filtered powder with varied content of 0.01, 0.02, and 0.03 mole, and precipitated by NH3 (25 mole%). After drying process, the final product subsequently was glucose coated magnetite (Fe3O4) nanoparticles. The characterizations performed were true density measurement, FTIR, VSM, XRD, BET, and adsorbent performance by AAS. The FTIR analysis showed that M-O (bending) with M=Fe (stretching vibration) with υ = 570.92 and 401.19 cm-1. While glucose coated well on nanoparticle Fe3O4, proved by functional groups C=O (stretching), M-O (stretching) and C-H (bending) with υ = 1404.17, 570.92, and 2368.58 cm-1, respectively. Single phase of magnetite (Fe3O4) structure was determined from XRD analysis with cubic spinel structure and lattice parameter of 8.396 Å. The optimum conditions, obtained on the Fe3O4 nanoparticles with 0.01 mole of glucose addition, which has true density value of 4.57 g/cm3, magnetic saturation, M s = 35,41 emu/g, coercivity, H cJ = 83.58 Oe, average particle size = 12.3 nm and surface area = 124.88 m2/g. This type magnetic nanoparticles of glucose-coated Fe3O4 was capable to adsorbed 93.78 % of ion Pb. Therefore, the glucose-coated Fe3O4 nanoparticle is a potential candidate to be used as heavy metal removal from wastewater.

  19. Optical Constants of Crystallized TiO2 Coatings Prepared by Sol-Gel Process

    Directory of Open Access Journals (Sweden)

    Jun Shen

    2013-07-01

    Full Text Available Titanium oxide coatings have been deposited by the sol-gel dip-coating method. Crystallization of titanium oxide coatings was then achieved through thermal annealing at temperatures above 400 °C. The structural properties and surface morphology of the crystallized coatings were studied by micro-Raman spectroscopy and atomic force microscopy, respectively. Characterization technique, based on least-square fitting to the measured reflectance and transmittance spectra, is used to determine the refractive indices of the crystallized TiO2 coatings. The stability of the synthesized sol was also investigated by dynamic light scattering particle size analyzer. The influence of the thermal annealing on the optical properties was then discussed. The increase in refractive index with high temperature thermal annealing process was observed, obtaining refractive index values from 1.98 to 2.57 at He-Ne laser wavelength of 633 nm. The Raman spectroscopy and atomic force microscopy studies indicate that the index variation is due to the changes in crystalline phase, density, and morphology during thermal annealing.

  20. Facile preparation and electrochemical properties of carbon coated Fe3O4 as anode material for lithium-ion batteries

    Science.gov (United States)

    Lv, Pengpeng; Zhao, Hailei; Zeng, Zhipeng; Wang, Jie; Zhang, Tianhou; Li, Xingwang

    2014-08-01

    Carbon coated Fe3O4 nanocomposite (Fe3O4/C) is synthesized via a simple sol-gel route and a subsequent carbon CVD process, with Fe2O3 xerogel as intermediate product. The nanoporous Fe2O3 xerogel is reduced to Fe3O4 during the CVD process. The prepared Fe3O4/C composite presents a well-distributed nanostructure composing of Fe3O4 nanoparticles coated with carbon layer. The electrode exhibits a stable reversible capacity of over 850 mAh g-1 at 0.1 A g-1, excellent cycling performance and good rate capability. Both of the nano-scale particle size of Fe3O4 and the carbon layer contribute to the excellent electrochemical performance of Fe3O4/C. An increase in electrode capacity with cycling is observed for the prepared Fe3O4/C composite when cycled at 50 °C, which is similar to other reported transition metal oxides. The preparation process of Fe3O4/C composite is facile, mild and productive.

  1. Microstructures of Ni–AlN composite coatings prepared by pulse electrodeposition technology

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Fafeng, E-mail: xiaff_npu@126.com [School of Mechanical Science and Engineering, Northeast Petroleum University, Daqing 163318 (China); Xu, Huibin [Department of Electronic and Information Engineering, Shanghai Normal University Tianhua College, Shanghai 201815 (China); Liu, Chao, E-mail: msm-liu@126.com [School of Electronics Science, Northeast Petroleum University, Daqing 163318 (China); Wang, Jinwu [School of Engineering, Northeast Agricultural University, Harbin 150030 (China); Ding, Junjie; Ma, Chunhua [School of Mechanical Science and Engineering, Northeast Petroleum University, Daqing 163318 (China)

    2013-04-15

    Ni–AlN composite coating was fabricated onto the surface of steel substrates by using pulse electrodeposition (PED) technique in this work. The effect of pulse current on the nucleation and growth of grains was investigated using transmission electronic microscopy (TEM), X-ray diffraction (XRD), scanning electronic microscopy (SEM) and atomic force microscopy (AFM), respectively. The results show that the contents of AlN nanoparticles increase with density of pulse current and on-duty ratio of pulse current increasing. Whereas the size of nickel grains decreases with density of pulse current increasing and on-duty ratio of pulse current decreasing. Ni–AlN composite coating consists of crystalline nickel (∼68 nm) and AlN particles (∼38 nm). SEM and AFM observations show that the composite coatings obtained by PED showed more compact surfaces and less grain sizes, whereas those obtained by direct current electrodepositing have rougher surfaces and bigger grain sizes.

  2. Antimicrobial Double-Layer Coating Prepared from Pure or Doped-Titanium Dioxide and Binders

    Directory of Open Access Journals (Sweden)

    Ran Li

    2018-01-01

    Full Text Available Fruit and vegetable containers with microbe-free surfaces can be made by coating with titanium dioxide (TiO2 particles or nonmetal (C, N, B, F doped-TiO2 particles, using wear resistant polymers, such as zein, and paint, as the binders and to form a continuous binding phase. The doped-TiO2 powders absorb visible light radiation, and thus possess a higher antibacterial effect than non-modified TiO2 particles in environmental conditions. The study also presents a double-layer coating to use less TiO2 particles in coating, while achieving higher antimicrobial activity. Containers with microbe-free surfaces can stop cross-contamination from infected workers or spoiled/decayed/contaminated fruits or vegetables, and thus are expected to be able to reduce the risk from microbiological contamination of fruits and vegetables during harvest in fields, and postharvest storage or transportation.

  3. Preparation and characterization of ultra-thin amphiphobic coatings on silicon wafers

    Energy Technology Data Exchange (ETDEWEB)

    Mou, Chun-Yueh, E-mail: cymou165@gmail.com; Yuan, Wei-Li; Shih, Chih-Hsin

    2013-06-30

    Fluorine-based amphiphobic coatings have been widely used in commercial domestic utensils and textiles to repel water and oil contaminants. However, few reports from the literature survey have discussed the effects on amphiphobicity of the nano- to micro-scale surface features of such a coating. In this research thin amphiphobic epoxy coatings based on a mixture of bisphenol A diglycidyl ether, tetraethylorthosilicate (TEOS), and a particular alkoxy silane with fluorinated side chains (F-silane) are deposited on silicon wafers. Film amphiphobicity is characterized by the measurement of water and oil contact angles of the coating. Film morphology is revealed in the scanned images using atomic force microscopy. The deposited films free of F-silane are about 10 nm thick. When a small amount of F-silane was firstly added, the water and oil contact angles of the deposited films jumped up to 107° and 69° respectively and then flattened out with increased F-silane. Water droplets gave an average plateau contact angle about 110°, while vegetable oil ones, 40°. It was noted that there is a dramatic decrease in the lyophobicity causing a reduction in contact angles. However, surface lyophobicity also depends on sub-microscopic surface structures. In addition, by increasing TEOS, it was shown that the formed silica sols or granules were helpful in enhancing the mechanical strength along with retaining the lyophobicity of the film. - Highlights: • Epoxy ultrathin films about 10 nm thick deposited on silicon wafer. • Nominal fluorinated silane added to epoxy coatings for amphiphobicity. • Surface lyophobicity retained by sub-micrometer granules in ultrathin coatings. • Film hardness improved by adding tetraethylorthosilicate.

  4. Efficiency enhancement of perovskite solar cells by fabricating as-prepared film before sequential spin-coating procedure

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Jiajia [Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of material science and technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China); Tao, Hai jun, E-mail: taohaijun@nuaa.edu.cn [Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of material science and technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China); Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu (China); Chen, Shanlong; Tan, Bin [Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of material science and technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China); Zhou, Ning [Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhu, Lumin; Zhao, Yuan [Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of material science and technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China); Wang, Yuqiao [Jiangsu Optoelectronic Functional Materials and Engineering Laboratory, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Tao, Jie [Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of material science and technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China)

    2016-05-15

    Graphical abstract: Schematic illustration of modified two-step spin-coating procedure for MAPbI{sub 3} perovskite thin films. - Highlights: • An as-prepared CH{sub 3}NH{sub 3}PbI{sub 3} and PbI{sub 2} film was introduced before the traditional two-step process. • Smooth morphology and trace amount of remaining PbI{sub 2} benefit the performance of solar cell. • The optimal as-prepared film introduced improves the efficiency of CH{sub 3}NH{sub 3}PbI{sub 3} solar cells from 9.11% to 11.16%. - Abstract: Sequential spin-coating procedure is a widely adopted strategy to prepare CH{sub 3}NH{sub 3}PbI{sub 3} on mesostructured TiO{sub 2} electrode for organolead halide perovskite-based solar cells. However, this method suffers from the rough surface and excessively residual PbI{sub 2} in the resulting perovskite film, deteriorating the device performance seriously. Herein, a facial modified sequential solution deposition method, by introducing an as-prepared CH{sub 3}NH{sub 3}PbI{sub 3} and PbI{sub 2} film before the traditional two-step process, was proposed to fabricate the perovskite-based solar cell with smooth morphology and trace amount of remaining PbI{sub 2}. The optimal as-prepared film introduced improves the efficiency of CH{sub 3}NH{sub 3}PbI{sub 3} solar cells from 9.11% to 11.16%. The enhancement of device performance can be attributed to the increased light absorption ability and decreased recombination rate of carriers in CH{sub 3}NH{sub 3}PbI{sub 3} absorber.

  5. Preparation and evaluation of PEGylated phospholipid membrane coated layered double hydroxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Mina Yan

    2016-06-01

    Full Text Available The aim of the present study was to develop layered double hydroxide (LDH nanoparticles coated with PEGylated phospholipid membrane. By comparing the size distribution and zeta potential, the weight ratio of LDH to lipid materials which constitute the outside membrane was identified as 2:1. Transmission electron microscopy photographs confirmed the core-shell structure of PEGylated phospholipid membrane coated LDH (PEG-PLDH nanoparticles, and cell cytotoxicity assay showed their good cell viability on Hela and BALB/C-3T3 cells over the concentration range from 0.5 to 50 μg/mL.

  6. Preparation of iron doped carbon coated W18O49 and its photoactivity.

    Directory of Open Access Journals (Sweden)

    Masahiro Toyoda

    2008-06-01

    Full Text Available Iron doping to carbon coated W18O49 was carried out through solid-state reaction of WO2.9 with iron acetate at 400 oC,followed by carbonization with poly(vinyl alcohol (PVA as carbon precursor at 800 oC in N2 atmosphere. Photoactivitiesof these samples were confirmed by phenol photodecomposition in its aqueous solution. They revealed the photoactivityunder visible light irradiation. Carbon coated W18O49 with iron exhibited higher photoactivity than it without iron. Additionof 1 % iron and 90/10 mixing ratio (WO2.9 / PVA derived the highest photoactivity to decompose the phenol.

  7. Electropolymerized nanoporous polymeric SPME coatings: preparation and characterization by small angle X-ray scattering and scanning electron microscopy.

    Science.gov (United States)

    Buszewski, Boguslaw; Olszowy, Pawel; Pikus, Stanislaw; Kozak, Maciej

    Polymeric polypyrrole and polythiophene solid phase microextraction (SPME) coatings were prepared using electropolymerization with a linear sweep voltammetry technique. Physicochemical properties were measured using different methods, in particular small angle X-ray scattering and scanning electron microscopy. By using innovative approaches for pore size measurement, we were able to calculate a maximum of the pore size range from 80 to 90 nm. Additionally, film thicknesses measured from 90 to 150 μm. Using scanning electron microscopy, we describe the characteristics of polymer growth on the support surface.

  8. SOURCES OF VARIABILITY IN COLLECTION AND PREPARATION OF PAINT AND LEAD-COATING SAMPLES

    Science.gov (United States)

    Chronic exposure of children to lead can result in permanent physiologic impairment. Since surfaces coated with lead-containing paints and varnishes are potential sources of exposure, it is extremely important that reliable methods for sampling and analysis be available. The so...

  9. Novel Active Surface Prepared by Embedded Functionalized Clays in an Acrylate Coating.

    Science.gov (United States)

    Xia, Yining; Ghasemlou, Mehran; Rubino, Maria; Auras, Rafael; Baghdachi, Jamil

    2015-11-11

    The research on a self-decontaminating surface has received significant attention because of the growth of pathogenic microorganisms on surfaces. In this study, a novel and simple technique for producing an active surface with antimicrobial functionality is demonstrated. A tethering platform was developed by grafting the biocide ampicillin (Amp) to a nanoclay and dispersing the nanoclay in a UV-curable acrylate coating applied on polypropylene films as the substrate. A coupling agent, [3-(glycidyloxy)propyl]trimethoxysilane, was used as a linker between the nanoclay and Amp. The Amp-functionalized clay was further modified with an organic surfactant to improve the compatibility with the coating. Several characterization assays, such as Fourier infrared transform analysis, thermogravimetric analysis, and X-ray diffraction, were conducted to confirm the presence of Amp in the nanoclay. Transmission electron microscopy images revealed that the clay particles were well dispersed in the coating and had a partial exfoliated morphology. The active coating surface was effective in inhibiting the growth of Gram-positive Listeria monocytogenes and Gram-negative Salmonella Typhimurium via contact. These findings suggest the potential for the development of active surfaces with the implementation of nanotechnology to achieve diverse functionalities.

  10. Preparation and stability of lipid-coated nanocapsules of cisplatin: anionic phospholipid specificity

    NARCIS (Netherlands)

    Velinova, M. J.; Staffhorst, R. W. H. M.; Mulder, W. J. M.; Dries, A. S.; Jansen, B. A. J.; de Kruijff, B.; de Kroon, A. I. P. M.

    2004-01-01

    Cisplatin nanocapsules represent a novel lipid formulation of the anti-cancer drug cis-diamminedichloroplatinum(II) (cisplatin), in which nanoprecipitates of cisplatin are coated by a phospholipid bilayer consisting of a 1:1 mixture of zwitterionic phosphatidylcholine (PC) and negatively charged

  11. Ceria based protective coatings for steel interconnects prepared by spray pyrolysis

    DEFF Research Database (Denmark)

    Szymczewska, Dagmara; Molin, Sebastian; Chen, Ming

    2014-01-01

    Stainless steels can be used in solid oxide fuel/electrolysis stacks as interconnects. For successful long term operation they require protective coatings, that lower the corrosion rate and block chemical reactions between the interconnect and adjacent layers of the oxygen or the hydrogen electrode...

  12. Hierarchical opal grating films prepared by slide coating of colloidal dispersions in binary liquid media.

    Science.gov (United States)

    Lee, Wonmok; Kim, Seulgi; Kim, Seulki; Kim, Jin-Ho; Lee, Hyunjung

    2015-02-15

    There are active researches on well ordered opal films due to their possible applications to various photonic devices. A recently developed slide coating method is capable of rapid fabrication of large area opal films from aqueous colloidal dispersion. In the current study, the slide coating of polystyrene colloidal dispersions in water/i-propanol (IPA) binary media is investigated. Under high IPA content in a dispersing medium, resulting opal film showed a deterioration of long range order, as well as a decreased film thickness due to dilution effect. From the binary liquid, the dried opal films exhibited the unprecedented topological groove patterns with varying periodic distances as a function of alcohol contents in the media. The groove patterns were consisted of the hierarchical structures of the terraced opal layers with periodic thickness variations. The origin of the groove patterns was attributed to a shear-induced periodic instability of colloidal concentration within a thin channel during the coating process which was directly converted to a groove patterns in a resulting opal film due to rapid evaporation of liquid. The groove periods of opal films were in the range of 50-500 μm, and the thickness differences between peak and valley of the groove were significantly large enough to be optically distinguishable, such that the coated films can be utilized as the optical grating film to disperse infra-red light. Utilizing a lowered hydrophilicity of water/IPA dispersant, an opal film could be successfully coated on a flexible Mylar film without significant dewetting problem. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Preparation of Microencapsulated Bacillus subtilis SL-13 Seed Coating Agents and Their Effects on the Growth of Cotton Seedlings

    Directory of Open Access Journals (Sweden)

    Liang Tu

    2016-01-01

    Full Text Available Inoculation of the bacterial cells of microbial seed coating agents (SCAs into the environment may result in limited survival and colonization. Therefore, the application efficacy of an encapsulated microbial seed coating agent (ESCA was investigated on potted cotton plants; the agent was prepared with polyvinyl alcohol, sodium dodecyl sulfate, bentonite, and microencapsulated Bacillus subtilis SL-13. Scanning electron micrography revealed that the microcapsules were attached to ESCA membranes. The ESCA film was uniform, bubble-free, and easy to peel. The bacterial contents of seeds coated with each ESCA treatment reached 106 cfu/seed. Results indicated that the germination rate of cotton seeds treated with ESCA4 (1.0% (w/v sodium alginate, 4.0% polyvinyl alcohol, 1.0% sodium dodecyl sulfate, 0.6% acacia, 0.5% bentonite, and 10% (v/v microcapsules increased by 28.74%. Other growth factors of the cotton seedlings, such as plant height, root length, whole plant fresh weight, and whole plant dry weight, increased by 52.70%, 25.13%, 46.47%, and 33.21%, respectively. Further analysis demonstrated that the peroxidase and superoxide dismutase activities of cotton seedlings improved, whereas their malondialdehyde contents decreased. Therefore, the ESCA can efficiently improve seed germination, root length, and growth. The proposed ESCA exhibits great potential as an alternative to traditional SCA in future agricultural applications.

  14. Preparation and properties of a double-coated slow-release NPK compound fertilizer with superabsorbent and water-retention.

    Science.gov (United States)

    Wu, Lan; Liu, Mingzhu; Rui Liang

    2008-02-01

    A double-coated slow-release NPK compound fertilizer with superabsorbent and water-retention was prepared by crosslinked poly(acrylic acid)/diatomite - containing urea (the outer coating), chitosan (the inner coating), and water-soluble granular fertilizer NPK (the core). The effects of the amount of crosslinker, initiator, degree of neutralization of acrylic acid, initial monomer and diatomite concentration on water absorbency were investigated and optimized. The water absorbency of the product was 75 times its own weight if it was allowed to swell in tap water at room temperature for 2 h. Atomic absorption spectrophotometer and element analysis results showed that the product contained 8.47% potassium (shown by K(2)O), 8.51% phosphorus (shown by P(2)O(5)), and 15.77% nitrogen. We also investigated the water-retention property of the product and the slow release behavior of N, P and K in the product. This product with excellent slow release and water-retention capacity, being nontoxic in soil and environment-friendly, could be especially useful in agricultural and horticultural applications.

  15. Improving chondrocyte harvests with poly(2-hydroxyethyl methacrylate coated materials in the preparation for cartilage tissue engineering

    Directory of Open Access Journals (Sweden)

    Mikako Harata

    2017-12-01

    Full Text Available Remarkable advances have been made in cartilage regenerative medicine to cure congenital anomalies including microtia, tissue defects caused by craniofacial injuries, and geriatric diseases such as osteoarthritis. However, those procedures require a substantial quantity of chondrocytes for tissue engineering. Previous studies have required several passages to obtain sufficient cell numbers for three-dimensional and monolayer cultures. Thus, our objective was to improve the quantity of chondrocytes that can be obtained by examining an anti-fouling polyhydrophilic chemical called poly(2-hydroxyethyl methacrylate (pHEMA. To determine the effectiveness of the chemical, pHEMA solution was applied via dip-coating to centrifuge tubes, serological pipettes, and pipette tips. The cell quantity obtained during standard cell culturing and passaging procedures was measured alongside non-coated materials as a control. A significant 2.2-fold increase of chondrocyte yield was observed after 2 passages when pHEMA was applied to the tubes compared to when non-coated tubes were utilized. The 3-dimensional chondrocyte pellets prepared from the respective cell populations and transplanted into nude mice were histologically and biochemically analyzed. No evidence of difference in matrix production for in vitro and in vivo cultures was found as well as similar proliferation rates and colony formation abilities. The use of pHEMA provides a powerful alternative method for expanding the quantity of chondrocytes harvested and handled during cell isolation and passaging to enhance cartilage tissue engineering.

  16. Sorption study of methylene blue on activated carbon prepared from Jatropha curcas and Terminalia catappa seed coats

    Directory of Open Access Journals (Sweden)

    Ismaila Olalekan Saheed

    2016-12-01

    Full Text Available This research work targets the effectiveness of the prepared activated carbon from Jatropha curcas and Terminalia catappa seed coats for the sorption of methylene blue (MB from aqueous solution. The prepared Jatropha activated carbon (JAC and Terminalia activated carbon (TAC were characterised using Fourier transform infrared spectroscopy (FTIR, Scanning electron microscopy (SEM and Branauer- Emmett-Teller (BET surface area analysis. Effect of initial concentration, pH, contact time, adsorbent dose and temperature on the sorption experiments were studied and the adsorption capacity of these adsorbents were found to be 37.84 mg/g and 17.44 mg/g for methylene blue uptake by JAC and TAC respectively. The experimental data were analysed using Langmuir, Fruendlich, and Dubinin-Radushkevich isotherms. The data fitted best into Langmuir isotherm for Methylene blue-JAC and Methylene blue-TAC systems. The kinetic studies fitted into pseudo second order kinetics model. The process chemistry was exothermic.

  17. Preparation and characterization of underwater superoleophobic chitosan/poly(vinyl alcohol) coatings for self-cleaning and oil/water separation

    Science.gov (United States)

    Wang, Qian; Fu, Youjia; Yan, Xiaoxia; Chang, Yanjiao; Ren, Lili; Zhou, Jiang

    2017-08-01

    In this paper, chitosan (CS)/poly(vinyl alcohol) (PVA) coatings cross-linked with glutaraldehyde (GA) were prepared. Effects of the coating composition and NaOH solution treatment on surface morphology and topography were investigated by scanning electron microscope and atomic force microscope. It was found that the process of immersing the CS/PVA coatings into NaOH solution was crucial to enhance rough structure on the coating surface. The rough surface structure and the hydrophilic groups of CS and PVA made the CS/PVA coatings possess underwater superoleophobicity and low adhesion to oil. Oil contact angle of the prepared CS/PVA coatings was up to 161° and slide angle was only 3°. Moreover, the CS/PVA coatings showed stable superoleophobicity in high salt, strong acidic, and alkaline environments as well as underwater self-cleaning property and excellent transparency. The CS/PVA coatings could be used for gravity driven oil/water separation with high efficiency.

  18. Influence of Pt particles on the porosity of Al{sub 2}O{sub 3} coating prepared by cathode plasma electrolytic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peng [Beijing Key Laboratory for Corrosion, Erosion and Surface Technology, University of Science and Technology Beijing, 100083, Beijing (China); Research Institute of Aerospace Special Materials and Processing Technology, 100074, Beijing (China); He, Yedong, E-mail: htgroup@mater.ustb.edu.cn [Beijing Key Laboratory for Corrosion, Erosion and Surface Technology, University of Science and Technology Beijing, 100083, Beijing (China); Zhang, Jin [Beijing Key Laboratory for Corrosion, Erosion and Surface Technology, University of Science and Technology Beijing, 100083, Beijing (China)

    2016-12-01

    Porous Al{sub 2}O{sub 3} and Al{sub 2}O{sub 3}-Pt coatings were successfully prepared on the Ni-based alloy by cathode plasma electrolytic deposition. It is found that the porosity of coatings can be reduced obviously by Pt particles co-deposited with Al{sub 2}O{sub 3}. This phenomenon can be attributed to that the mechanism of plasma discharge is changed in such CPED. As the Pt particles are dispersed in the Al{sub 2}O{sub 3} coating, the electron avalanche is difficult to occur. So, the breakdown takes place in the Al{sub 2}O{sub 3}-Pt coating difficultly, the destructive effect of the breakdown will therefore be decreased, and the porosity of Al{sub 2}O{sub 3} coating can be reduced which has been verified by the results of surface morphologies of the coatings. - Highlights: • The Al{sub 2}O{sub 3}-Pt coatings were prepared on Ni-based alloys by CPED. • The porosity of coating is reduced obviously by Pt particles dispersed with Al{sub 2}O{sub 3}. • The related mechanisms of plasma discharge in CPED were discussed.

  19. Antifouling and Antibacterial Multifunctional Polyzwitterion/Enzyme Coating on Silicone Catheter Material Prepared by Electrostatic Layer-by-Layer Assembly.

    Science.gov (United States)

    Vaterrodt, Anne; Thallinger, Barbara; Daumann, Kevin; Koch, Dereck; Guebitz, Georg M; Ulbricht, Mathias

    2016-02-09

    effect. Enzyme activity was found to be dependent on the depth of embedment in the multilayer coating. Depending on the used polymeric building block, up to a 60% reduction in the amount of adhering bacteria and clear evidence for killed bacteria due to the antimicrobial functionality of the coating could be confirmed. Overall, this work demonstrates the feasibility of an easy to perform and shape-independent method for preparing an antifouling and antimicrobial coating for the significant reduction of biofilm formation and thus reducing the risk of acquiring infections by using urinary catheters.

  20. Preparation and characterization of amorphous SiO{sub 2} coatings deposited by mirco-arc oxidation on sintered NdFeB permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.L., E-mail: jlxu@nchu.edu.cn [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Xiao, Q.F.; Mei, D.D. [School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Zhong, Z.C., E-mail: zzhong2014@sina.com [The Institute for Rare Earth Magnetic Materials and Devices, Jiangxi University of Science and Technology, Ganzhou 341000 (China); Tong, Y.X. [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Zheng, Y.F., E-mail: yfzheng@pku.edu.cn [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Li, L. [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China)

    2017-03-15

    Amorphous SiO{sub 2} coatings were prepared on sintered NdFeB magnets by micro-arc oxidation (MAO) in silicate solution. The surface and cross-sectional morphologies, element and phase composition, corrosion resistance and magnetic properties of the coatings were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), potentiodynamic polarization test and physical properties measurements system (PPMS). The results showed that the surface morphologies of the coatings exhibited the “coral reef” like structure, different from the typical MAO porous structure. With increasing the voltages, the thickness of the coatings increased from 12.72 to 19.90 µm, the content of Si element increased, while the contents of Fe, Nd and P elements decreased. The coatings were mainly composed of amorphous SiO{sub 2} and a few amorphous Fe{sub 2}O{sub 3} and Nd{sub 2}O{sub 3}. The amorphous SiO{sub 2} coatings presented excellent thermal shock resistance, while the thermal shock resistance decreased with increasing the voltages. The corrosion resistance of the coatings increased with increasing the voltages, and it could be enhanced by one order of magnitude compared to the uncoated NdFeB magnets. The MAO coatings slightly decreased the magnetic properties of the NdFeB samples in different degrees. - Highlights: • Amorphous SiO{sub 2} coatings were prepared on sintered NdFeB magnets by micro-arc oxidation. • The coatings presented excellent thermal shock resistance. • The corrosion resistance could be enhanced by one order of magnitude. • The MAO coatings slightly decreased the magnetic properties of the NdFeB samples.

  1. Study on the poisoning resistance of Pd-coated ZrCo alloy prepared by electroless plating method

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xiumei, E-mail: xiumei418@163.com; Wang, Shumao; Li, Zhinian; Yuan, Baolong; Ye, Jianhua; Qiu, Haochen; Wu, Yuanfang; Liu, Xiaopeng; Jiang, Lijun

    2016-12-15

    Highlights: • The Pd membrane was prepared by electroless plating method. • The Pd membrane was compact and uniform. • The effectiveness of Pd membranes was affected by impurity contents and temperatures. - Abstract: To improve the poisoning resistance of ZrCo alloy, Pd membranes have been prepared over the surface of the alloy substrates by using electroless plating method. The characteristics of Pd membranes have been examined by XRD, SEM, EDS and EPMA technologies. From SEM images, the uniform and compact thin Pd film was revealed. The effect of this Pd film was evaluated by comparing the hydrogen absorption properties of bare and Pd-coated ZrCo specimens in contaminated hydrogen gas. The degradation of hydrogen absorption of Pd-coated ZrCo induced by poisoning was less than that of bare ZrCo sample obviously, meaning that the Pd membranes over the surface of substrates appeared to be effective in improving the poisoning resistance of ZrCo alloy. Furthermore, the effect became more significant with the increasing of impurity contents in the experimental gas and the operation temperatures.

  2. Preparation of Stable Superhydrophobic Coatings on Wood Substrate Surfaces via Mussel-Inspired Polydopamine and Electroless Deposition Methods

    Directory of Open Access Journals (Sweden)

    Kaili Wang

    2017-06-01

    Full Text Available Mussel-inspired polydopamine (PDA chemistry and electroless deposition approaches were used to prepare stable superhydrophobic coatings on wood surfaces. The as-formed PDA coating on a wood surface exhibited a hierarchical micro/nano roughness structure, and functioned as an “adhesive layer” between the substrate and a metallic film by the metal chelating ability of the catechol moieties on PDA, allowing for the formation of a well-developed micro/nanostructure hierarchical roughness. Additionally, the coating acted as a stable bridge between the substrate and hydrophobic groups. The morphology and chemical components of the prepared superhydrophobic wood surfaces were characterized by scanning electron microscopy (SEM, Fourier transform infrared (FT-IR spectroscopy, and X-ray photoelectron spectroscopy (XPS. The PDA and octadecylamine (OA modified surface showed excellent superhydrophobicity with a water contact angle (CA of about 153° and a rolling angle (RA of about 9°. The CA further increased to about 157° and RA reduced to about 5° with the Cu metallization. The superhydrophobic material exhibited outstanding stability in harsh conditions including ultraviolet aging, ultrasonic washing, strong acid-base and organic solvent immersion, and high-temperature water boiling. The results suggested that the PDA/OA layers were good enough to confer robust, degradation-resistant superhydrophobicity on wood substrates. The Cu metallization was likely unnecessary to provide significant improvements in superhydrophobic property. However, due to the amazing adhesive capacity of PDA, the electroless deposition technique may allow for a wide range of potential applications in biomimetic materials.

  3. Facile Preparation of Water-Dispersible Graphene Sheets Stabilized by Carboxylated Oligoanilines and Their Anticorrosion Coatings.

    Science.gov (United States)

    Gu, Lin; Liu, Shuan; Zhao, Haichao; Yu, Haibin

    2015-08-19

    Dispersion of graphene in solvents is of crucial importance toward its practical applications. In this study, using a water-soluble carboxylated aniline trimer derivative (CAT(-)) as a stabilizer, the commercial graphene can be stably dispersed in water at high concentration (>1 mg/mL) via strong π-π interaction that was proved by Raman and UV-vis spectra. Moreover, the CAT(-)-functionalized graphene sheets (G-CAT(-) hybrid) exhibited high conductivity (∼1.5 S/cm), good electroactivity and improved electrochemical stability. The addition of well-dispersed graphene into waterborne epoxy system (G-CAT(-)/epoxy) remarkably improved corrosion protection compared with pure waterborne epoxy coating, based on a series of electrochemical measurements performed under 3.5% NaCl solution. This significantly enhanced anticorrosion performance is mainly due to the improved water barrier properties derived from highly dispersed graphene nanosheets in the epoxy coating.

  4. Photoinduced carbene generation from diazirine modified task specific phosphonium salts to prepare robust hydrophobic coatings.

    Science.gov (United States)

    Ghiassian, Sara; Ismaili, Hossein; Lubbock, Brett D W; Dube, Jonathan W; Ragogna, Paul J; Workentin, Mark S

    2012-08-21

    3-Aryl-3-(trifluormethyl)diazirine functionalized highly fluorinated phosphonium salts (HFPS) were synthesized, characterized, and utilized as photoinduced carbene precursors for covalent attachment of the HFPS onto cotton/paper to impart hydrophobicity to these surfaces. Irradiation of cotton and paper, as proof of concept substrates, treated with the diazirine-HFPS leads to robust hydrophobic cotton and paper surfaces with antiwetting properties, whereas the corresponding control samples absorb water readily. The contact angles of water were determined to be 139° and 137° for cotton and paper, respectively. In contrast, water placed on the untreated or the control samples (those treated with the diazirine-HFPS but not irradiated) is simply absorbed into the surface. Additionaly, the chemically grafted hydrophobic coating showed high durability toward wash cycles and sonication in organic solvents. Because of the mode of activation to covalently tether the hydrophobic coating, it is amenable to photopatterning, which was demonstrated macroscopically.

  5. Preparation of bone-implants by coating hydroxyapatite nanoparticles on self-formed titanium dioxide thin-layers on titanium metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Wijesinghe, W.P.S.L.; Mantilaka, M.M.M.G.P.G.; Chathuranga Senarathna, K.G. [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Herath, H.M.T.U. [Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Department of Medical Laboratory Science, Faculty of Allied Health Sciences, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Premachandra, T.N. [Department of Veterinary Pathobiology, Faculty of Veterinary Medicine, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Ranasinghe, C.S.K. [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Rajapakse, R.P.V.J. [Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Department of Veterinary Pathobiology, Faculty of Veterinary Medicine, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Rajapakse, R.M.G., E-mail: rmgr@pdn.ac.lk [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Edirisinghe, Mohan; Mahalingam, S. [Department of Mechanical Engineering, University College London, London WC1E 7JE (United Kingdom); Bandara, I.M.C.C.D. [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, 2 George Street, Brisbane 4001, QLD (Australia); Singh, Sanjleena [Central Analytical Research Facility, Institute of Future Environments, Queensland University of Technology, 2 George Street, Brisbane 4001, QLD (Australia)

    2016-06-01

    Preparation of hydroxyapatite coated custom-made metallic bone-implants is very important for the replacement of injured bones of the body. Furthermore, these bone-implants are more stable under the corrosive environment of the body and biocompatible than bone-implants made up of pure metals and metal alloys. Herein, we describe a novel, simple and low-cost technique to prepare biocompatible hydroxyapatite coated titanium metal (TiM) implants through growth of self-formed TiO{sub 2} thin-layer (SFTL) on TiM via a heat treatment process. SFTL acts as a surface binder of HA nanoparticles in order to produce HA coated implants. Colloidal HA nanorods prepared by a novel surfactant-assisted synthesis method, have been coated on SFTL via atomized spray pyrolysis (ASP) technique. The corrosion behavior of the bare and surface-modified TiM (SMTiM) in a simulated body fluid (SBF) medium is also studied. The highest corrosion rate is found to be for the bare TiM plate, but the corrosion rate has been reduced with the heat-treatment of TiM due to the formation of SFTL. The lowest corrosion rate is recorded for the implant prepared by heat treatment of TiM at 700 °C. The HA-coating further assists in the passivation of the TiM in the SBF medium. Both SMTiM and HA coated SMTiM are noncytotoxic against osteoblast-like (HOS) cells and are in high-bioactivity. The overall production process of bone-implant described in this paper is in high economic value. - Highlights: • Colloidal hydroxyapatite nanorods are prepared by a novel method. • Surfaces of titanium metal plates are modified by self-forming TiO{sub 2} thin-films. • Prostheses are prepared by coating hydroxyapatite on surface modified Ti metal. • Bioactivity and noncytotoxicity are increased with surface modifications.

  6. Preparation of tantalum carbide films by reaction of electrolytic carbon coating with the tantalum substrate

    OpenAIRE

    Massot, Laurent; Chamelot, Pierre; Taxil, Pierre

    2006-01-01

    This article demonstrates that coatings of tantalum carbide can be obtained by electrodeposition of carbon in molten fluorides on a tantalum substrate as an alternative to the CVD process. The structural characteristics of the carbon deposited by the electrolytic route lead to a high reactivity of this element towards a tantalum cathode to produce tantalum carbide. Mutual reactivity was shown to be enhanced if tantalum plate is replaced by an electrodeposited layer of tantalum, where th...

  7. Chromatographic matrix based on hydrogel-coated reticulated polyurethane foams, prepared by gamma irradiation

    Science.gov (United States)

    Sánchez, Mirna L.; Giménez, Claudia Y.; Delgado, Juan F.; Martínez, Leandro J.; Grasselli, Mariano

    2017-12-01

    Novel chromatographic materials for protein purification with high adsorption capacity and fouling resistance are highly demanded to improve downstream processes. Here, we describe a novel adsorptive material based on reticulated polyurethane foam (rPUF) coated with a functional hydrogel layer. rPUF provides physical rigidity through its macroscopic structure, whereas the hydrogel layer provides capacity to adsorb proteins by specific interactions. The hydrogel coating process was performed by the dip-coating method, using a polyvinyl alcohol (PVA) solution. The PVA hydrogel was linked to the rPUF material by using a radiation-induced crosslinking process in aqueous ethanol solution. The ethanol in the solvent mixture allowed a balance between PVA swelling and PVA dissolution during the irradiation step. The resulting material showed higher thermal stability than the non-irradiated one. In addition, a simultaneous radiation-induced grafting polymerization (SRIGP) was done by simple addition of glycidyl methacrylate monomer into the irradiation solution. In a further step, sulfonic ligands were included specifically in the hydrogel layer, which contained around 200% of PVA respect to the original rPUF. Materials were characterized by FT-IR, thermogravimetric analysis, SEM microscopy and EDX analysis. The cation-exchange rPUF material was functionally characterized by the Langmuir isotherm and a dynamic adsorption experiment to analyze the chromatographic properties for protein purification processes.

  8. Preparation and Characterization of Quaternized Chitosan Coated Alginate Microspheres for Blue Dextran Delivery

    Directory of Open Access Journals (Sweden)

    Kuo-Yu Chen

    2017-06-01

    Full Text Available In this study, 2-[(Acryloyloxyethyl]trimethylammonium chloride was graft polymerized onto chitosan (CS to form quaternary ammonium CS (QAC by using ammonium persulfate as a redox initiator. Alginate (ALG microspheres loaded with a water-soluble macromolecular model drug, blue dextran (BD, were obtained by corporation of coaxial gas-flow method and ionic gelation process. CS and QAC were then coated on the surfaces of ALG microspheres to generate core/shell structured CS/ALG and QAC/ALG microspheres, respectively. The experiment result showed that QAC/ALG microspheres had a smaller particle size due to the stronger electrostatic interactions between QAC and ALG molecules. In vitro drug release studies at pH 7.4 and pH 9.0 exhibited that the release rate of BD was significantly decreased after ALG microspheres coating with CS and QAC. Moreover, ALG microspheres coated with QAC showed a prolonged release profile for BD at pH 9.0. Therefore, QAC/ALG microspheres may be a promising hydrophilic macromolecular drug carrier for a prolonged and sustained delivery.

  9. Preparation of Zinc Oxide-Starch Nanocomposite and Its Application on Coating

    Science.gov (United States)

    Ma, Jinxia; Zhu, Wenhua; Tian, Yajun; Wang, Zhiguo

    2016-04-01

    A new production method of zinc oxide (ZnO)-starch nanocomposite was invented in this study. Starch was dissolved in zinc chloride (ZnCl2) solution (65 wt%) at 80 °C. Then, ZnO-starch nanocomposite was achieved when the pH of the solution was adjusted to 8.4 by NaOH solution (15 wt%). ZnO nanoparticles were also obtained when the generated ZnO-starch nanocomposite was calcined at 575 °C. The properties of ZnO-starch nanocomposite and ZnO nanoparticle were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated that the sizes of ZnO-starch composite and ZnO particle were 40-60 nm. UV blocking effect was observed from both ZnO-starch nanocomposite and ZnO nanoparticle. The ZnO-starch nanocomposite was used to directly coat the surface of plain paper with a laboratory paper coater. The surface strength and smoothness of paper were improved by the coating of ZnO-starch nanocomposite. The antibacterial property was also identified from the coated paper.

  10. Preparation, characterization and in vitro response of bioactive coatings on polyether ether ketone.

    Science.gov (United States)

    Durham, John W; Allen, Matthew J; Rabiei, Afsaneh

    2017-04-01

    Polyether ether ketone (PEEK) is a highly heat-resistant thermoplastic with excellent strength and elastic modulus similar to human bone, making it an attractive material for orthopedic implants. However, the hydrophobic surface of PEEK implants induces fibrous encapsulation which is unfavorable for stable implant anchorage. In this study, PEEK was coated via ion-beam-assisted deposition (IBAD) using a two-layer design of yttria-stabilized zirconia (YSZ) as a heat-protection layer, and hydroxyapatite (HA) as a top layer to improve osseointegration. Microstructural analysis of the coatings showed a dense, uniform columnar grain structure in the YSZ layer and no delamination from the substrate. The HA layer was found to be amorphous and free of porosities in its as-deposited state. Subsequent heat treatment via microwave energy followed by autoclaving crystallized the HA layer, confirmed by SEM and XRD analysis. An in vitro study using MC3T3 preosteoblast cells showed improved bioactivity in heat-treated sample groups. Cell proliferation, differentiation, and mineralization were analyzed by MTT assay and DNA content, osteocalcin expression, and Alizarin Red S (AR-S) content, respectively. Initial cell growth was increased, and osteogenic maturation and mineralization were accelerated most on coatings that underwent a combined microwave and autoclave heat treatment process as compared to uncoated PEEK and amorphous HA surfaces. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 560-567, 2017. © 2015 Wiley Periodicals, Inc.

  11. Preparation of silver-chitosan nanocomposites and coating on bandage for antibacterial wound dressing application

    Science.gov (United States)

    Susilowati, Endang; Maryani, Ashadi

    2016-02-01

    Bandage is a medical device that is essential for wound dressing. To improve the performance of the bandage, it has been coated by silver-chitosan nanocomposites (Ag/Chit) with pad-dry-cure method. The nanocomposites were performed by chemical reduction method at room temperature using glucose as reducing agent, sodium hydroxide (NaOH) as accelerator reagent, silver nitrate (AgNO3) as metal precursor and chitosan as stabilizing agent. Localized surface plasmon resonance (LSPR) absorption band of silver nanoparticles was investigated using UV-Vis spectrophotometer. The bandage coated Ag/Chit nanocomposites (B-Ag/Chit) were characterized by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). In addition, antibacterial activity of the bandage toward Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) were also studied. The formation of silver nanoparticles was confirmed by the appearance of LSPR absorption peak at 412.2 - 423.2 nm. Coating of nanocomposite cause increasing rigidity of bandage and decreasing on crystallinity. The bandages of B-Ag/Chit demonstrated good activity against both Gram positive (S. aureus) and Gram negative (E.Coli). Thus the bandages have a potential to be used for antibacterial wound dressing application.

  12. Preparation of silver-chitosan nanocomposites and coating on bandage for antibacterial wound dressing application

    Energy Technology Data Exchange (ETDEWEB)

    Susilowati, Endang, E-mail: endwati@yahoo.co.id; Ashadi [Chemistry Education Department, Faculty of Teacher Training and Education, Universitas Sebelas Maret Surakarta (Indonesia); Maryani [Medical Doctor Program, Faculty of Medicine, Universitas Sebelas Maret Surakarta, Indonesia Jl. Ir Sutami 36 A Surakarta Indonesia 53126 (Indonesia)

    2016-02-08

    Bandage is a medical device that is essential for wound dressing. To improve the performance of the bandage, it has been coated by silver-chitosan nanocomposites (Ag/Chit) with pad-dry-cure method. The nanocomposites were performed by chemical reduction method at room temperature using glucose as reducing agent, sodium hydroxide (NaOH) as accelerator reagent, silver nitrate (AgNO{sub 3}) as metal precursor and chitosan as stabilizing agent. Localized surface plasmon resonance (LSPR) absorption band of silver nanoparticles was investigated using UV-Vis spectrophotometer. The bandage coated Ag/Chit nanocomposites (B-Ag/Chit) were characterized by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). In addition, antibacterial activity of the bandage toward Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) were also studied. The formation of silver nanoparticles was confirmed by the appearance of LSPR absorption peak at 412.2 – 423.2 nm. Coating of nanocomposite cause increasing rigidity of bandage and decreasing on crystallinity. The bandages of B-Ag/Chit demonstrated good activity against both Gram positive (S. aureus) and Gram negative (E.Coli). Thus the bandages have a potential to be used for antibacterial wound dressing application.

  13. Preparation, Characterization, and Millimeter Wave Attenuation of Carbon Fibers Coated with Ni-Cu-P and Ni-Co-P Alloys

    Science.gov (United States)

    Ye, Mingquan; Li, Zhitao; Wang, Chen; Han, Aijun

    2015-12-01

    Composite carbon fibers (CFs) coated with Ni-X-P (X = Cu, Co, none) alloys were prepared by electroless plating. The morphology, crystal structure, elemental composition, and millimeter wave (MMW) attenuation performance of the alloy-coated CFs were characterized by scanning electron microscopy, x-ray diffractometry, energy-dispersive spectrometry, and microwave attenuation. CFs were coated with a layer of alloy particles. The P content in the Ni-Cu-P or Ni-Co-P-coated alloy was lower than that in the Ni-P alloy, and coating alloy Ni-P was amorphous. Coating alloys exhibited crystal characteristics after Cu or Co introduction. MMW-attenuation performance of alloy-coated CFs showed that the 3 and 8 mm wave-attenuation effects of CF/Ni-Cu-P and CF/Ni-Co-P were better than those of CF/Ni-P and CFs. The 8 mm wave-attenuation values and their increases were larger than those of the 3 mm wave. The MMW-attenuation performance is attributable to the alloy bulk resistivity and P content. The 3 mm wave-attenuation effects of wavelength-coated CF samples were slightly larger than those of the half wavelength samples. An optimal weight gain value existed for the MMW-attenuation performance of alloy-coated CFs.

  14. A novel technique using arti-spot coated on fleximeter strips to determine the clearance during tooth preparation in fixed partial denture

    Directory of Open Access Journals (Sweden)

    Soma Sundaram Prasadh

    2015-01-01

    Full Text Available The amount of occlusal clearance during tooth preparation for fixed partial denture is more crucial and critical phase of fixed prosthodontics. Improper tooth reduction leads to compromise in structural durability and failure of the restoration. Over reduction affects the biological principles of tooth preparation. This article uses color coded fleximeter strips coated with arti-spot to determine the amount of clearance during tooth preparation in fixed partial denture.

  15. La bibliothèque dans Buffy contre les vampires : grimoires et merveilles

    Directory of Open Access Journals (Sweden)

    Vanessa Bertho

    2008-01-01

    Full Text Available Avec cent quarante quatre épisodes de 1997 à 2003, la série Buffy contre les vampires a su occuper l’univers télévisuel américain et international par sa régénération fictionnelle dans le domaine des œuvres fantastiques pour adolescents. Les intrigues mettent en scène Buffy Summers, jeune californienne de la ville de Sunnydale. La tombée de la nuit y provoque la transformation d’établissements tout à fait respectables en espaces fantastiques. Leur influence dans les épisodes est indéniable, participant à l’atmosphère néogothique générale. Parmi eux, la bibliothèque revêt un aspect tout particulier. Quelle peut être sa place dans ce type de fiction ? Pourquoi mettre en lumière une telle structure ? Que révèle son usage ? Lieu de savoir, espace de narration et même personnage à part entière, son importance est aussi bien qualitative que quantitative. Durant les trois premières saisons, elle est un élément clé du lycée, comme source de savoir et par son aspect collégial. Dans une atmosphère scolaire, elle s’affirme en effet comme le lieu de rassemblement et de sociabilité nécessaire aux personnages principaux. Son usage habituel est détourné pour en faire un indispensable recueil d’indices et de récits sur l’histoire et les mythes rattachés aux figures fantastiques environnantes. La narration imprègne les deux faces de la bibliothèque, en développant les intrigues affectives le jour et les recherches d’ordre surnaturel au crépuscule. Elle s’avère incontournable pour la progression dramatique de la diégèse et l’installation des systèmes de représentation mythologiques. Lieu, institution et espace de narrativité, « l’armoire à livres » de Buffy contre les vampires est aussi un personnage à part entière. Elle s’inscrit ainsi dans l’orientation scénaristique de la série, qui réactive des éléments ancrés dans l’imaginaire collectif pour les moderniser en

  16. Synthesis and characterization of MoS2/Ti composite coatings on Ti6Al4V prepared by laser cladding

    Directory of Open Access Journals (Sweden)

    Rongjuan Yang

    2013-02-01

    Full Text Available The MoS2/Ti composite coating with sub-micron grade structure has been prepared on Ti6Al4V by laser method under argon protection. The morphology, microstructure, microhardness and friction coefficient of the coating were examined. The results indicated that the molybdenum disulfide was decomposed during melting and resolidification. The phase organization of composite coating mainly consisted of ternary element sulfides, molybdenum sulfides and titanium sulfides. The friction coefficient of and the surface roughness the MoS2/Ti coating were lower than those of Ti6Al4V. The composite coating exhibits excellent adhesion to the substrates, less surface roughness, good wear resistance and harder surface.

  17. Preparation of Solid Phase Microextraction (SPME) Probes through Polyaniline Multiwalled Carbon Nanotubes (PANI/MWCNTs) Coating for the Extraction of Palmitic Acid and Oleic Acid in Organic Solvents.

    Science.gov (United States)

    Khajeamiri, Alireza

    2012-01-01

    A fiber coating from polyaniline (PANI) was electrochemically prepared and employed for Solid phase micreoextraction (SPME). The PANI film was directly electrodeposited on the platinum wire surface using cyclic voltametry (CV) technique. The same method was applied for the preparation of SPME fiber coated by polyaniline multiwalled carbon nanotubes (PANI/MWCNTs) composite. The concentration of sulfuric acid for electropolymerization was 0.1 M in the presence of 0.045 M aniline in aqueous solution. For the electrodeposition of PANI/MWCNT composite, 4 μg/mL of MWCNTs was dispersed into the solution. Film coating was carried out on the platinum wire by repetitive cycling of potentials between 0 and 1.0 V at the scan rate of 0.05 V/s. The applicability of these coatings were assessed through employing a laboratory-made SPME injecting device and gas chromatography with mass spectrometry (GC-MS) for the extraction of palmitic acid and oleic acid from chloroform. The developed method proved to be simple and easy, offering high reproducibility. Both PANI coated and PANI/CNT coated probes had the ability to concentrate palmitic acid and oleic acid on their coating and produced strong signals in GC-MS chromatograms. In the meantime, PANI/CNT coated SPME probes produced signals which were stronger than those produced by PANI coated SPME probes. The amount of extracted palmitic acid and oleic acid from chloroform by the PANI/MWCNTs coating was about 6 and 12 times higher than the amount extracted by plane PANI SPME fibers respectively. It could be suggested that the composite material with CNTs has both an increased surface area and an elevated absorptive capacity which leads to this overall increase in extracted palmitic acid and oleic acid.

  18. The HtrA2 Drosophila model of Parkinson's disease is suppressed by the pro-survival Bcl-2 Buffy.

    Science.gov (United States)

    M'Angale, P Githure; Staveley, Brian E

    2017-01-01

    Mutations in High temperature requirement A2 (HtrA2), also designated PARK13, which lead to the loss of its protease activity, have been associated with Parkinson's disease (PD). HtrA2 is a mitochondrial protease that translocates to the cytosol upon the initiation of apoptosis where it participates in the abrogation of inhibitors of apoptosis (IAP) inhibition of caspases. Here, we demonstrate that the loss of the HtrA2 function in the dopaminergic neurons of Drosophila melanogaster results in PD-like phenotypes, and we attempt to restore the age-dependent loss in locomotor ability by co-expressing the sole pro-survival Bcl-2 homologue Buffy. The inhibition of HtrA2 in the dopaminergic neurons of Drosophila resulted in shortened lifespan and impaired climbing ability, and the overexpression of Buffy rescued the reduction in lifespan and the age-dependent loss of locomotor ability. In supportive experiments, the inhibition of HtrA2 in the Drosophila eye results in eye defects, marked by reduction in ommatidia number and increased disruption of the ommatidial array; phenotypes that are suppressed by the overexpression of Buffy.

  19. Numerical Control Device for Preparation Nano-Carbon Granule Coating Superhydrophobic Template and Its Application

    Science.gov (United States)

    Shang, G. R.; Li, Y.

    2017-12-01

    It is one of the ways for changing surface property by fabricating superhydrophibic coating with the help of template that is made of depositing nano-carbon particles of fuel flame on substrate such as pure copper or aluminium alloy. In the process of making template, it is difficult to keep the deposition layer uniformed. In this work, the problem was solved by manufacturing a set of numerical control equipment. It has been proved by application test that the deposition layer was uniformed by means of this facility. The contact angle is more than 150°. A new way has been developed for making superhydrohibic template.

  20. Preparation and properties of poly(vinylidene fluoride nanocomposites blended with graphene oxide coated silica hybrids

    Directory of Open Access Journals (Sweden)

    Q. Fu

    2012-04-01

    Full Text Available Graphene oxide coated silica hybirds (SiO2-GO were fabricated through electrostatic assembly in this work, then blended with poly(vinylidene fluoride (PVDF by solution mixing to make PVDF nanocomposites. The interfacial interaction was investigated by scanning electron microscopy (SEM, polarized optical microscopy (POM and Fourier transform infrared spectroscopy (FTIR. The results showed that the interfacial interaction was enhanced by adding of SiO2-GO and strong hydrogen bonds were observed. The as-made nanocomposites were investigated using standard tensile test and dynamic mechanical analysis (DMA measurements, mechanical properties of PVDF with SiO2-GO hybrids showed limited improvement.

  1. Preparation and characterization of Ag-coated cenospheres by magnetron sputtering method

    Energy Technology Data Exchange (ETDEWEB)

    Yu Xiaozheng [Beijing Key Laboratory for Powder Technology R and D, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China); Nanotechnology Industrialization Base of China, Tianjin 300457 (China); Shen Zhigang [Beijing Key Laboratory for Powder Technology R and D, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China); Nanotechnology Industrialization Base of China, Tianjin 300457 (China)], E-mail: shenzhg@buaa.edu.cn; Xu, Zheng [General Research Institute for Non-ferrous Metals, Beijing 100088 (China)

    2007-12-15

    In this paper, we show the feasibility of the magnetron sputtering deposition technique to grow 10-100-nm thick, uniform, continuous and well adhesive silver films on cenosphere particles so that the properties of the core particles can be suitably modified. Experiments were conducted with a magnetron sputtering deposition system in which a newly designed sample stage equipped with an ultrasonic vibration generator was used for the tumbling of cenosphere particles. The cenosphere particles are characterized by X-ray diffraction (XRD) analysis, field emission scanning electron microscope (FE-SEM) and inductively coupled plasma-atom emission spectrometer (ICP-AES) before and after the coating process. All results show the metal film has been successfully coated onto cenosphere particles. Under the given conditions, up to 3.0 wt.% silver was deposited on cenosphere particles measured by ICP-AES. The FE-SEM results indicate that at the micro-scale the relatively uniform, compact and well adhesive silver films with about 51 nm thickness were successfully deposited on cenosphere particles. The XRD analytic result indicates that the nanometer metal film has a face-centered cubic structure.

  2. Preparation and characterization of Ag-coated cenospheres by magnetron sputtering method

    Science.gov (United States)

    Yu, Xiaozheng; Shen, Zhigang; Xu, Zheng

    2007-12-01

    In this paper, we show the feasibility of the magnetron sputtering deposition technique to grow 10-100-nm thick, uniform, continuous and well adhesive silver films on cenosphere particles so that the properties of the core particles can be suitably modified. Experiments were conducted with a magnetron sputtering deposition system in which a newly designed sample stage equipped with an ultrasonic vibration generator was used for the tumbling of cenosphere particles. The cenosphere particles are characterized by X-ray diffraction (XRD) analysis, field emission scanning electron microscope (FE-SEM) and inductively coupled plasma-atom emission spectrometer (ICP-AES) before and after the coating process. All results show the metal film has been successfully coated onto cenosphere particles. Under the given conditions, up to 3.0 wt.% silver was deposited on cenosphere particles measured by ICP-AES. The FE-SEM results indicate that at the micro-scale the relatively uniform, compact and well adhesive silver films with about 51 nm thickness were successfully deposited on cenosphere particles. The XRD analytic result indicates that the nanometer metal film has a face-centered cubic structure.

  3. Chitosan-Coated Magnetic Nanoparticles Prepared in One Step by Reverse Microemulsion Precipitation

    Science.gov (United States)

    López, Raúl G.; Pineda, María G.; Hurtado, Gilberto; de León, Ramón Díaz; Fernández, Salvador; Saade, Hened; Bueno, Darío

    2013-01-01

    Chitosan-coated magnetic nanoparticles (CMNP) were obtained at 70 °C and 80 °C in a one-step method, which comprises precipitation in reverse microemulsion in the presence of low chitosan concentration in the aqueous phase. X-ray diffractometry showed that CMNP obtained at both temperatures contain a mixture of magnetite and maghemite nanoparticles with ≈4.5 nm in average diameter, determined by electron microscopy, which suggests that precipitation temperature does not affect the particle size. The chitosan coating on nanoparticles was inferred from Fourier transform infrared spectrometry measurements; furthermore, the carbon concentration in the nanoparticles allowed an estimation of chitosan content in CMNP of 6%–7%. CMNP exhibit a superparamagnetic behavior with relatively high final magnetization values (≈49–53 emu/g) at 20 kOe and room temperature, probably due to a higher magnetite content in the mixture of magnetic nanoparticles. In addition, a slight direct effect of precipitation temperature on magnetization was identified, which was ascribed to a possible higher degree of nanoparticles crystallinity as temperature at which they are obtained increases. Tested for Pb2+ removal from a Pb(NO3)2 aqueous solution, CMNP showed a recovery efficacy of 100%, which makes them attractive for using in heavy metals ion removal from waste water. PMID:24084716

  4. Preparation and characterization of amorphous SiO2 coatings deposited by mirco-arc oxidation on sintered NdFeB permanent magnets

    Science.gov (United States)

    Xu, J. L.; Xiao, Q. F.; Mei, D. D.; Zhong, Z. C.; Tong, Y. X.; Zheng, Y. F.; Li, L.

    2017-03-01

    Amorphous SiO2 coatings were prepared on sintered NdFeB magnets by micro-arc oxidation (MAO) in silicate solution. The surface and cross-sectional morphologies, element and phase composition, corrosion resistance and magnetic properties of the coatings were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), potentiodynamic polarization test and physical properties measurements system (PPMS). The results showed that the surface morphologies of the coatings exhibited the "coral reef" like structure, different from the typical MAO porous structure. With increasing the voltages, the thickness of the coatings increased from 12.72 to 19.90 μm, the content of Si element increased, while the contents of Fe, Nd and P elements decreased. The coatings were mainly composed of amorphous SiO2 and a few amorphous Fe2O3 and Nd2O3. The amorphous SiO2 coatings presented excellent thermal shock resistance, while the thermal shock resistance decreased with increasing the voltages. The corrosion resistance of the coatings increased with increasing the voltages, and it could be enhanced by one order of magnitude compared to the uncoated NdFeB magnets. The MAO coatings slightly decreased the magnetic properties of the NdFeB samples in different degrees.

  5. Gadolinium-doped zinc oxide thin films prepared on different substrates by sol-gel spin-coating

    Science.gov (United States)

    Fadzilah, A. R. Nurul; Othman, R. N.; Miskon, A.; Sahdan, M. Z.; Tawil, S. N. M.

    2017-12-01

    Gadolinium (Gd) doped zinc oxide (ZnO) thin films were prepared by sol-gel spin-coating technique. The solution was prepared using zinc acetate dihydrate and monoethanolamine (MEA) as a stabilizer. The Gd-doped ZnO thin films were deposited on different substrates; glass, aluminium doped ZnO (AZO), fluorine doped tin oxide (FTO) and silicon (Si). The structural and optical properties of Gd-doped ZnO on different substrates were studied using X-ray Diffraction (XRD), Field-Emission Scanning Electron Microscope-Energy Dispersive X-ray (FESEM-EDX) and Ultra Violet-Visible spectrophotometer (UV-Vis), respectively. Based on the XRD data, the crystallite size of the films was found to be in the range of 12.26 ˜ 22.95 nm, which shows a hexagonal wurtzite structure. Transmittance spectra of films deposited on AZO indicates a clear sinusoidal behavior as compared to samples prepared on glass and FTO. All samples exhibit magnetic properties at room temperature measured by means of Vibrating Sample Magnetometer (VSM).

  6. Preparation of Mn-containing mixed-oxide thin films by a dip-coating method using metal naphthenates

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, S.; Sugiyama, S.; Mazuka, N. (Shizuoka Univ., Shizuoka (Japan). Faculty of Engineering); Murakami, K. (Shizuoka Univ., Shizuoka (Japan). Research Inst. of Electronics); Yamada, T. (Nissei Electric Co. Ltd., Shizuoka (Japan))

    1994-07-01

    Mn-Co-Ni-O thin films with a metal atomic ratio of 3:2:1, which is expected to result in a negative temperature coefficient of resistance, have been prepared by means of dip coating in a toluene solution containing the corresponding metal naphthenates. The metal naphthenates decomposed thermally to become mixed oxides upon heat treatment at 450[degree]C. A Mn-Co-Ni-O thin film of an appropriate composition for use as a thermistor has been prepared from the mixed metal naphthenates by further heating at temperatures above 700[degree]C. The as-prepared thin film almost completely crystallized to form a complex spinel phase, a solid solution of MnCo2O4 and NiMn2O4, by further heat treatment at temperatures above 700[degree]C for 1h. The sheet resistance of the film was markedly lowered after heat treatment at temperatures above 600[degree]C. The temperature dependence of resistance of the film heat-treated at 700[degree]C was nonlinear. The thermal characteristics of the resistance show that the film is a promising material for use as a thermistor. 13 refs., 5 figs.

  7. Hydrogel Micro-/Nanosphere Coated by a Lipid Bilayer: Preparation and Microscopic Probing

    Directory of Open Access Journals (Sweden)

    Sarah Rahni

    2017-02-01

    Full Text Available The result of polymeric nanogels and lipid vesicles interaction—lipobeads—can be considered as multipurpose containers for future therapeutic applications, such as targeted anticancer chemotherapy with superior tumor response and minimum side effects. In this work, micrometer sized lipobeads were synthesized by two methods: (i mixing separately prepared microgels made of poly(N-isopropylacrylamide (PNIPA and phospholipid vesicles of micrometer or nanometer size and (ii polymerization within the lipid vesicles. For the first time, a high vacuum scanning electron microscopy was shown to be suitable for a quick validation of the structural organization of wet lipobeads and their constituents without special sample preparation. In particular, the structural difference of microgels prepared by thermal and UV-polymerization in different solvents was revealed and three types of giant liposomes were recognized under high vacuum in conjunction with their size, composition, and method of preparation. Importantly, the substructure of the hydrogel core and multi- and unilamellar constructions of the peripheral lipid part were explicitly distinguished on the SEM images of lipobeads, justifying the spontaneous formation of a lipid bilayer on the surface of microgels and evidencing an energetically favorable structural organization of the hydrogel/lipid bilayer assembly. This key property can facilitate lipobeads’ preparation and decrease technological expenses on their scaled production. The comparison of the SEM imaging with the scanning confocal and atomic force microscopies data are also presented in the discussion.

  8. Preparation, Characterization and in vivo Evaluation of Simple Monolithic Ethylcellulose-coated Pellets Containing Topiramate with Biphasic Release Characteristics.

    Science.gov (United States)

    Gong, Wei; Wang, Yuli; Shao, Shuai; Xie, Si; Shan, Li; Yang, Meiyan; Gao, Chunsheng; Zhong, Wu

    2016-01-01

    In our previous study, polyvinylpyrrolidone (PVP) was used both as a binder and a pore-former to prepare ethylcellulose (EC)-coated pellets to deliver topiramate (TPM) for a controlled release profile. The objective of this work was to further optimize the formulation and evaluate the in vivo profiles of TPM sustained-release pellets. Similar to the previous formulation with no binder, the in vitro drug release of TPM sustained-release pellets with 50% PVP binder in drug layer was sensitive to pore-former PVP level ranged from 27.0% to 29.0%. The higher the level of PVP was, the quicker release rate in vitro was. Moreover, when the proportion of poreformer PVP decreased, the Cmax decreased, and the tmax and mean residence time of TPM coated pellets were both prolonged. The in vitro release profile of optimal formulation showed biphasic release characteristics similar to reference formulation Trokendi XR(®), i.e., involving immediate release of TPM in initial release stage followed by a sustained release up to 24 h. Moreover, the impact of the pH of release medium on the drug release rate of TPM sustained-release pellets was not significant. The release mechanism of TPM from the sustained-release pellets might be the interaction of diffusion (coating-film) and corrosion (drug layer). The in vivo pharmacokinetics results showed the TPM sustained-release pellets had the similar in vivo pattern compared with Trokendi XR(®). These studies provide valuable basis for further development of TPM sustained-release pellets.

  9. Design and preparation of binary-binary SnO2-ZnO:F/MgF2/SiO2 transparent conducting oxide coatings

    Directory of Open Access Journals (Sweden)

    S Hadavi

    2012-12-01

    Full Text Available   In this study, we prepared the binary-binary TCO compounds of SnO2-ZnO by the spray pyrolysis technique. We also investigated the role of MgF2/SiO2 antireflection coatings in reducing optical reflectance in the visible region of TCO. Before preparation , we simulated the optical transmition of the films for optimizing the layer thicknesses. The results of this study showed increasing of optical transmittance in the visible region of TCO by adding antireflection coating layers.

  10. Mechanical particle coating using polymethacrylate nanoparticle agglomerates for the preparation of controlled release fine particles: The relationship between coating performance and the characteristics of various polymethacrylates.

    Science.gov (United States)

    Kondo, Keita; Kato, Shinsuke; Niwa, Toshiyuki

    2017-10-30

    We aimed to understand the factors controlling mechanical particle coating using polymethacrylate. The relationship between coating performance and the characteristics of polymethacrylate powders was investigated. First, theophylline crystals were treated using a mechanical powder processor to obtain theophylline spheres (<100μm). Second, five polymethacrylate latexes were powdered by spray freeze drying to produce colloidal agglomerates. Finally, mechanical particle coating was performed by mixing theophylline spheres and polymethacrylate agglomerates using the processor. The agglomerates were broken under mechanical stress to coat the spheres effectively. The coating performance of polymethacrylate agglomerates tended to increase as their pulverization progressed. Differences in the grindability of the agglomerates were attributed to differences in particle structure, resulting from consolidation between colloidal particles. High-grindability agglomerates exhibited higher pulverization as their glass transition temperature (Tg) increased and the further pulverization promoted coating. We therefore conclude that the minimization of polymethacrylate powder by pulverization is an important factor in mechanical particle coating using polymethacrylate with low deformability. Meanwhile, when product temperature during coating approaches Tg of polymer, polymethacrylate was soften to show high coating performance by plastic deformation. The effective coating by this mechanism may be accomplished by adjusting the temperature in the processor to the Tg. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Advanced fabrication method for the preparation of MOF thin films: Liquid-phase epitaxy approach meets spin coating method.

    KAUST Repository

    Chernikova, Valeriya

    2016-07-14

    Here we report a new and advanced method for the fabrication of highly oriented/polycrystalline metal-organic framework (MOF) thin films. Building on the attractive features of the liquid-phase epitaxy (LPE) approach, a facile spin coating method was implemented to generate MOF thin films in a high-throughput fashion. Advantageously, this approach offers a great prospective to cost-effectively construct thin-films with a significantly shortened preparation time and a lessened chemicals and solvents consumption, as compared to the conventional LPE-process. Certainly, this new spin-coating approach has been implemented successfully to construct various MOF thin films, ranging in thickness from a few micrometers down to the nanometer scale, spanning 2-D and 3-D benchmark MOF materials including Cu2(bdc)2•xH2O, Zn2(bdc)2•xH2O, HKUST-1 and ZIF-8. This method was appraised and proved effective on a variety of substrates comprising functionalized gold, silicon, glass, porous stainless steel and aluminum oxide. The facile, high-throughput and cost-effective nature of this approach, coupled with the successful thin film growth and substrate versatility, represents the next generation of methods for MOF thin film fabrication. Thereby paving the way for these unique MOF materials to address a wide range of challenges in the areas of sensing devices and membrane technology.

  12. Advanced Fabrication Method for the Preparation of MOF Thin Films: Liquid-Phase Epitaxy Approach Meets Spin Coating Method.

    Science.gov (United States)

    Chernikova, Valeriya; Shekhah, Osama; Eddaoudi, Mohamed

    2016-08-10

    Here, we report a new and advanced method for the fabrication of highly oriented/polycrystalline metal-organic framework (MOF) thin films. Building on the attractive features of the liquid-phase epitaxy (LPE) approach, a facile spin coating method was implemented to generate MOF thin films in a high-throughput fashion. Advantageously, this approach offers a great prospective to cost-effectively construct thin-films with a significantly shortened preparation time and a lessened chemicals and solvents consumption, as compared to the conventional LPE-process. Certainly, this new spin-coating approach has been implemented successfully to construct various MOF thin films, ranging in thickness from a few micrometers down to the nanometer scale, spanning 2-D and 3-D benchmark MOF materials including Cu2(bdc)2·xH2O, Zn2(bdc)2·xH2O, HKUST-1, and ZIF-8. This method was appraised and proved effective on a variety of substrates comprising functionalized gold, silicon, glass, porous stainless steel, and aluminum oxide. The facile, high-throughput and cost-effective nature of this approach, coupled with the successful thin film growth and substrate versatility, represents the next generation of methods for MOF thin film fabrication. Therefore, paving the way for these unique MOF materials to address a wide range of challenges in the areas of sensing devices and membrane technology.

  13. Preparation of PEI-coated bacterial biosorbent in water solution: optimization of manufacturing conditions using response surface methodology.

    Science.gov (United States)

    Mao, Juan; Kwak, In-Seob; Sathishkumar, Muthuswamy; Sneha, Krishnamurthy; Yun, Yeoung-Sang

    2011-01-01

    The aim of this study is to optimize preparation method of polyethyleneimine (PEI)-coated bacterial biosorbent in water as reaction media using fermentation waste biomass of Corynebacterium glutamicum as a raw material. The fermentation waste biomass of C. glutamicum and Reactive Red 4 were used as model raw bacterium and pollutant. Major factors affecting the performance of PEI-coated biosorbent were the amounts of polymer (PEI) and cross-linker glutaraldehyde (GA). These factors were optimized through response surface methodology (RSM) with two-level-two-factor (2(2)) full factorial central composite design. As a result, the optimum conditions were found to be 4.29 g of PEI and 0.15 mL of GA, with 10 g of the biomass, where the sorption capacity was enhanced 4.52-fold compared to that of the raw biomass. Therefore, this simple, cost-effective, and water-based method could be a useful modification tool for the development of a high performance biosorbent for removing anionic pollutants. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Comparison of sorption capacity and surface area of activated carbon prepared from Jatropha curcas fruit pericarp and seed coat

    Directory of Open Access Journals (Sweden)

    O.M. Ameen

    2012-08-01

    Full Text Available Activated carbons were prepared from fruit pericarp and seed coat of Jatropha curcas using KOH and NaCl as activating agents leading to the production of four samples of activated carbons JPS, JPP, JCS and JCP. The adsorption capacity based on adsorption of methylene blue was determined for each sample. A further study of adsorptive properties of the most efficient activated carbon (JPS was made by contacting it with standard solutions of methylene blue, acetic acid and potassium permanganate. The effects of mass of active carbon used, initial concentration of the solute and the pH of the solution on adsorption performance were investigated. Ash content and percentage fixed carbon were determined for two of the activated carbons (JPS and JCS with the highest adsorptive capacity. Equilibrium study on adsorption was carried out and the adsorption data were analyzed using the Langmuir isotherm. The results obtained indicate that activated carbons from the fruit pericarp and the seed coat of J. curcas can be used as high performance adsorbents with the fruit pericarp activated carbon showing the higher adsorption capacity. The adsorption data fitted well to the Langmuir model and adsorptive area of 824–910 m2/g was obtained for the activated carbon.DOI: http://dx.doi.org/10.4314/bcse.v26i2.2

  15. Grain morphology of YBCO coated superconductors prepared by spin process on Ni substrate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.F.; Du, S.J.; Yan, G.; Xi, W.; Wu, X.; Pang, Y.; Wang, F.Y.; Liu, X.H.; Feng, Y.; Zhang, P.X.; Wu, X.Z.; Zhou, L

    2003-04-15

    The YBCO thick films with c-axis preferred orientation were prepared by spin and printing processes on Ni substrates (including cold rolling Ni, cube textured Ni, and cube textured Ni+self-oxided NiO). The results show that the chrysanthemum (or spherulite) and polygon morphology grains dominate the microstructure of YBCO films. The chrysanthemum size is about 0.2-0.5 mm range, some reaches 1 mm, and polygon grains normally are placed in the center of the chrysanthemum grains. No chrysanthemum grains appear in the thick films prepared on the substrate with Ag or YBCO intermediate layers.

  16. Preparation and characterisation of Chlorogenic acid-gelatin: A type of biologically active film for coating preservation.

    Science.gov (United States)

    Fu, Shalu; Wu, Chunhua; Wu, Tiantian; Yu, Haixia; Yang, Shuibing; Hu, Yaqin

    2017-04-15

    Chlorogenic acid (CGA), a type of plant polyphenol, was conjugated onto gelatin (Gel) to prepare a novel coating material for the preservation of fresh seafood. The optimal reaction molar ratio of CGA to gelatin (4:1) was determined according to the CGA content in the CGA-Gel conjugate. CGA was confirmed to be successfully conjugated onto gelatin by 1H nuclear magnetic resonance and Fourier transform-infrared spectroscopy. The antioxidant activity of CGA-Gel was proven to be higher than that of the free CGA in 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) radical scavenging, hydrogen peroxide scavenging, ferric ion reducing power and lipid oxidation assays. The minimum inhibitory concentrations (MIC) of CGA against Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes and Staphylococcus aureus were 1, 1, 2 and 2mg/mL, respectively. The antibacterial activity of CGA-Gel was unaffected by conjugation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Chitosan-Coated Magnetic Nanoparticles with Low Chitosan Content Prepared in One-Step

    Directory of Open Access Journals (Sweden)

    Yolanda Osuna

    2012-01-01

    Full Text Available Chitosan-coated magnetic nanoparticles (CMNP were obtained at 50°C in a one-step method comprising coprecipitation in the presence of low chitosan content. CMNP showed high magnetization and superparamagnetism. They were composed of a core of 9.5 nm in average diameter and a very thin chitosan layer in accordance with electron microscopy measurements. The results from Fourier transform infrared spectrometry demonstrated that CMNP were obtained and those from thermogravimetric analysis allowed to determine that they were composed of 95 wt% of magnetic nanoparticles and 5 wt% of chitosan. 67% efficacy in the Pb+2 removal test indicated that only 60% of amino groups on CMNP surface bound to Pb, probably due to some degree of nanoparticle flocculation during the redispersion. The very low weight ratio chitosan to magnetic nanoparticles obtained in this study, 0.053, and the high yield of the precipitation reactions (≈97% are noticeable.

  18. Preparation and Characterization of Highly Fluorescent, Glutathione-coated Near Infrared Quantum Dots for in Vivo Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Yoshichika Yoshioka

    2008-10-01

    Full Text Available Fluorescent probes that emit in the near-infrared (NIR, 700-1,300 nm region are suitable as optical contrast agents for in vivo fluorescence imaging because of low scattering and absorption of the NIR light in tissues. Recently, NIR quantum dots (QDs have become a new class of fluorescent materials that can be used for in vivo imaging. Compared with traditional organic fluorescent dyes, QDs have several unique advantages such as size- and composition-tunable emission, high brightness, narrow emission bands, large Stokes shifts, and high resistance to photobleaching. In this paper, we report a facile method for the preparation of highly fluorescent, water-soluble glutathione (GSH-coated NIR QDs for in vivo imaging. GSH-coated NIR QDs (GSH-QDs were prepared by surface modification of hydrophobic CdSeTe/CdS (core/shell QDs. The hydrophobic surface of the CdSeTe/CdS QDs was exchanged with GSH in tetrahydrofuran-water. The resulting GSH-QDs were monodisperse particles and stable in PBS (phosphate buffered saline, pH = 7.4. The GSH-QDs (800 nm emission were highly fluorescent in aqueous solutions (quantum yield = 22% in PBS buffer, and their hydrodynamic diameter was less than 10 nm, which is comparable to the size of proteins. The cellular uptake and viability for the GSH-QDs were examined using HeLa and HEK 293 cells. When the cells were incubated with aqueous solutions of the GSH-QDs (10 nM, the QDs were taken into the cells and distributed in the perinuclear region of both cells. After 12 hrs incubation of 4 nM of GSH-QDs, the viabilities of HeLa and HEK 293 cells were ca. 80 and 50%, respectively. As a biomedical utility of the GSH-QDs, in vivo NIRfluorescence imaging of a lymph node in a mouse is presented.

  19. Preparation and characterization of carbon/nickel oxide nanocomposite coatings for solar absorber applications

    CSIR Research Space (South Africa)

    Roro, Kittessa T

    2012-04-01

    Full Text Available Nanocomposite materials have wide range of applications in solar energy conversion. In this work, C/NiO nanocomposite solar energy absorbing surfaces were prepared using sol-gel synthesis and deposited on aluminium substrates using a spin coater...

  20. Adhesion property and high-temperature oxidation behavior of Cr-coated Zircaloy-4 cladding tube prepared by 3D laser coating

    Science.gov (United States)

    Kim, Hyun-Gil; Kim, Il-Hyun; Jung, Yang-Il; Park, Dong-Jun; Park, Jeong-Yong; Koo, Yang-Hyun

    2015-10-01

    A 3D laser coating technology using Cr powder was developed for Zr-based alloys considering parameters such as: the laser beam power, inert gas flow, cooling of Zr-based alloys, and Cr powder control. This technology was then applied to Zr cladding tube samples to study the effect of Cr coating on the high-temperature oxidation of Zr-based alloys in a steam environment of 1200 °C for 2000s. It was revealed that the oxide layer thickness formed on the Cr-coated tube surface was about 25-times lower than that formed on a Zircaloy-4 tube surface. In addition, both the ring compression and the tensile tests were performed to evaluate the adhesion properties of the Cr-coated sample. Although some cracks were formed on the Cr-coated layer, the Cr-coated layer had not peeled off after the two tests.

  1. Facile preparation of polyethylenimine-tannins coated SiO2 hybrid materials for Cu2+ removal

    Science.gov (United States)

    Huang, Qiang; Liu, Meiying; Zhao, Jiao; Chen, Junyu; Zeng, Guangjian; Huang, Hongye; Tian, Jianwen; Wen, Yuanqing; Zhang, Xiaoyong; Wei, Yen

    2018-01-01

    Polyethylenimine-tannins coated SiO2 (SiO2@PEI-TA) hybrid materials have been prepared via a single-step multifunctional coating with polyethylenimine (PEI) and tannins (TA), and characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The as-prepared SiO2@PEI-TA composites were examined as adsorbents to remove the Cu2+ from aqueous solution. The effects of contact time, initial Cu2+ concentration, solution pH and temperature, on Cu2+ adsorption have been investigated. The results show that the adsorption of Cu2+ onto SiO2@PEI-TA is dependent on the contact time, Cu2+ concentration, pH and temperature. The SiO2@PEI-TA composites show a 2.4-fold increase in adsorption capacity, implying that the introduction of PEI-TA coating is in favor of the Cu2+ adsorption. Based on the analysis of kinetic data, the kinetics of Cu2+ adsorption is more accurately described by the pseudo-second-order model. The equilibrium data are analyzed by Langmuir and Freundlich isotherms. Results of isotherms show that the better agreement is Freundlich isotherm model with correlation coefficient of 0.9914, which suggests that the adsorption of Cu2+ onto SiO2@PEI-TA is mainly a heterogeneous adsorption process. Thermodynamic analyses show that the adsorption interaction is actually a spontaneous and endothermic chemical process, which might involve the chemical chelation between Cu2+ and functional groups (amine and carboxyl groups) on the surface of SiO2@PEI-TA. In addition, the Cu2+ ions could desorb from SiO2@PEI-TA by using acid solution and the adsorption efficiency remains at high level after five adsorption-desorption recycles. These results provide potential applications of these novel adsorbents for the removal of heavy metal Cu2+ from aqueous solution and also provide strong evidence to support the adsorption mechanism proposed in the study.

  2. Preparation of sulfonated graphene/polypyrrole solid-phase microextraction coating by in situ electrochemical polymerization for analysis of trace terpenes.

    Science.gov (United States)

    Zhang, Chengjiang; Zhang, Zhuomin; Li, Gongke

    2014-06-13

    In this study, a novel sulfonated graphene/polypyrrole (SG/PPy) solid-phase microextraction (SPME) coating was prepared and fabricated on a stainless-steel wire by a one-step in situ electrochemical polymerization method. Crucial preparation conditions were optimized as polymerization time of 15min and SG doping amount of 1.5mg/mL. SG/PPy coating showed excellent thermal stability and mechanical durability with a long lifespan of more than 200 stable replicate extractions. SG/PPy coating demonstrated higher extraction selectivity and capacity to volatile terpenes than commonly-used commercial coatings. Finally, SG/PPy coating was practically applied for the analysis of volatile components from star anise and fennel samples. The majority of volatile components identified were terpenes, which suggested the ultra-high extraction selectivity of SG/PPy coating to terpenes during real analytical projects. Four typical volatile terpenes were further quantified to be 0.2-27.4μg/g from star anise samples with good recoveries of 76.4-97.8% and 0.1-1.6μg/g from fennel samples with good recoveries of 80.0-93.1%, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Bioactive glass-ceramic coatings prepared by pulsed laser deposition from RKKP targets (sol-gel vs melt-processing route)

    Energy Technology Data Exchange (ETDEWEB)

    Rau, J.V., E-mail: giulietta.rau@ism.cnr.it [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133 Rome (Italy); Teghil, R. [Universita della Basilicata, Dipartimento di Chimica ' A.M. Tamburro' , Via dell' Ateneo Lucano, 10-85100 Potenza (Italy); CNR-IMIP U.O.S. di Potenza, Zona Industriale di Tito scalo (PZ) (Italy); Fosca, M. [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133 Rome (Italy); Universita di Roma ' La Sapienza' , Dipartimento di Chimica, Piazzale Aldo Moro, 5-00185 Rome (Italy); De Bonis, A. [Universita della Basilicata, Dipartimento di Chimica ' A.M. Tamburro' , Via dell' Ateneo Lucano, 10-85100 Potenza (Italy); CNR-IMIP U.O.S. di Potenza, Zona Industriale di Tito scalo (PZ) (Italy); Cacciotti, I.; Bianco, A. [Universita di Roma ' Tor Vergata' , Dipartimento di Ingegneria Industriale, UR INSTM ' Roma Tor Vergata' , Via del Politecnico, 1-00133 Rome (Italy); Albertini, V. Rossi [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133 Rome (Italy); Caminiti, R. [Universita di Roma ' La Sapienza' , Dipartimento di Chimica, Piazzale Aldo Moro, 5-00185 Rome (Italy); Ravaglioli, A. [Parco Torricelli delle Arti e delle Scienze, Via Granarolo, 64-48018 Faenza (Ra) (Italy)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Bioactive glass-ceramic coatings for bone tissue repair and regeneration. Black-Right-Pointing-Pointer Pulsed Lased Deposition allowed congruent transfer of target composition to coating. Black-Right-Pointing-Pointer Target was prepared by sol-gel process suitable for compositional tailoring. Black-Right-Pointing-Pointer Titanium, widely used for orthopaedics and dental implants, was used as substrate. Black-Right-Pointing-Pointer The physico-chemical properties of the prepared coatings are reported. -- Abstract: The deposition of innovative glass-ceramic composition (i.e. RKKP) coatings by Pulsed Lased Deposition (PLD) technique is reported. RKKP was synthesised following two methodologies: melt-processing and sol-gel, the latter being particularly suitable to tailor the compositional range. The PLD advantage with respect to other deposition techniques is the congruent transfer of the target composition to the coating. The physico-chemical properties of films were investigated by Scanning Electron and Atomic Force Microscopies, Fourier Transform Infrared Spectroscopy, Angular and Energy Dispersive X-ray Diffraction, and Vickers microhardness. The deposition performed at 12 J/cm{sup 2} and 500 Degree-Sign C allows to prepare crystalline films with the composition that replicates rather well that of the initial targets. The 0.6 {mu}m thin melt-processing RKKP films, possessing the hardness of 25 GPa, and the 4.3 {mu}m thick sol-gel films with the hardness of 17 GPa were obtained.

  4. Preparation and characterization of B{sub 4}C coatings for advanced research light sources

    Energy Technology Data Exchange (ETDEWEB)

    Störmer, Michael, E-mail: michael.stoermer@hzg.de [Helmholtz-Zentrum Geesthacht, Max-Planck-Strasse 1, D-21502 Geesthacht (Germany); Siewert, Frank [Helmholtz-Zentrum Berlin, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Sinn, Harald [European XFEL GmbH, Albert-Einstein-Ring 19, 22761 Hamburg (Germany)

    2016-01-01

    The challenging specifications for long X-ray mirrors for upcoming free-electron lasers can be achieved, especially for maintaining below 2 nm peak-to-valley shape error along the optical aperture of approximately 1 m-long mirrors. X-ray optical elements are required for beam transport at the current and upcoming free-electron lasers and synchrotron sources. An X-ray mirror is a combination of a substrate and a coating. The demand for large mirrors with single layers consisting of light or heavy elements has increased during the last few decades; surface finishing technology is currently able to process mirror lengths up to 1 m with microroughness at the sub-nanometre level. Additionally, thin-film fabrication is able to deposit a suitable single-layer material, such as boron carbide (B{sub 4}C), some tens of nanometres thick. After deposition, the mirror should provide excellent X-ray optical properties with respect to coating thickness errors, microroughness values and slope errors; thereby enabling the mirror to transport the X-ray beam with high reflectivity, high beam flux and an undistorted wavefront to an experimental station. At the European XFEL, the technical specifications of the future mirrors are extraordinarily challenging. The acceptable shape error of the mirrors is below 2 nm along the whole length of 1 m. At the Helmholtz-Zentrum Geesthacht (HZG), amorphous layers of boron carbide with thicknesses in the range 30–60 nm were fabricated using the HZG sputtering facility, which is able to cover areas up to 1500 mm long by 120 mm wide in one step using rectangular B{sub 4}C sputtering targets. The available deposition area is suitable for the specified X-ray mirror dimensions of upcoming advanced research light sources such as the European XFEL. The coatings produced were investigated by means of X-ray reflectometry and interference microscopy. The experimental results for the B{sub 4}C layers are discussed according to thickness uniformity, density

  5. Silica-Copper Oxide Composite Thin Films as Solar Selective Coatings Prepared by Dipping Sol Gel

    Directory of Open Access Journals (Sweden)

    E. Barrera-Calva

    2008-01-01

    Full Text Available Silica-copper oxide (silica-CuO composite thin films were prepared by a dipping sol-gel route using ethanolic solutions comprised TEOS and a copper-propionate complex. Sols with different TEOS/Cu-propionate (Si/Cu molar ratios were prepared and applied on stainless steel substrates using dipping process. During the annealing process, copper-propionate complexes developed into particulate polycrystalline CuO dispersed in a partially crystallized silica matrix, as indicated by the X-ray diffraction (XRD and X-ray photoelectron spectroscopy (XPS analyses. The gel thermal analysis revealed that the prepared material might be stable up to 400°C. The silica-CuO/stainless steel system was characterized as a selective absorber surface and its solar selectivity parameters, absorptance (α, and emittance (ε were evaluated from UV-NIR reflectance data. The solar parameters of such a system were mostly affected by the thickness and phase composition of the SiO2-CuO film. Interestingly, the best solar parameters (α = 0.92 and ε = 0.2 were associated to the thinnest films, which comprised a CuO-Cu2O mixture immersed in the silica matrix, as indicated by XPS.

  6. Preparation of platinum- and silver-incorporated TiO2 coatings in thin-film photoreactor for the photocatalytic decomposition of o-cresol.

    Science.gov (United States)

    Kuo, Yu-Lin; Su, Te-Li; Chuang, Kai-Jen; Chen, Hua-Wei; Kung, Fu-Chen

    2011-12-01

    Platinum-incorporated TiO2 (Pt-TiO2) and silver-incorporated TiO2 (Ag-TiO2) coatings on sapphire tubes of a thin-film photoreactor were prepared using a photoreduction process. Results of X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) revealed that the Ag-TiO2 coatings consisted of a mixture of Ag2O, Ag and TiO2 particles, owing to the partial oxidization of silver particles on the TiO2 coatings, while the Pt-TiO2 coating contained a mixture of Pt and TiO2 particles. Diffuse reflectance UV-Vis spectra (DRS) showed that metal particles (Ag or Pt) incorporated into the TiO2 coatings promoted optical absorption in the visible region and made it possible for the coatings to be excited by visible light. Photoluminescence (PL) spectra showed that the PL intensity of the Pt-TiO2 coating was lower than that of the Ag-TiO2 and TiO2 coatings, indicating that the Pt-TiO2 coating had a higher efficiency of charge carrier trapping, immigration and transfer, which subsequently promoted the pseudo-first-order rate constants after the UV/TiO2 process. The Pt-TiO2 coatings for the photocatalytic decomposition of o-cresol under UV light irradiation corresponded to a higher pseudo-first-order rate constant (k) of 0.02 min(-1) when compared with the photocatalytic decomposition rates of pure TiO2 coatings (k = 0.0062 min(-1)) and Ag-TiO2 coatings (k = 0.01 min(-1)). The experimental results also indicated that the photodegradation rate of the Pt-TiO2 coating under visible light irradiation was significantly higher than the photodegradation rates of the Ag-TiO2 and pure TiO2 coatings.

  7. PREPARATION OF TITANIA SOL-GEL COATINGS CONTAINING SILVER IN VARIOUS FORMS AND MEASURING OF THEIR BACTERICIDAL EFFECTS AGAINST E. COLI

    Directory of Open Access Journals (Sweden)

    Diana Horkavcova

    2015-09-01

    Full Text Available The work describes titania coatings containing various forms of silver applied on a titanium substrate by a dip-coating sol-gel technique. Silver was added into the basic titania sol in form of colloid particles of Ag, crystals of AgNO3, particles of AgI, particles of Ag3PO4 and Ag3PO4 developed in situ (in the sol by reaction of AgNO3 with added calcium phosphate (brushite or monetite. Mechanically and chemically treated titanium substrates were dipped at a constant rate into individual types of sols. Subsequently, they were slowly fired. The fired coatings contained microcracks. All over the surface there were evenly distributed spherical nanoparticles of silver (Ag, AgNO3 or microcrystals of AgI and Ag3PO4. The prepared coatings were tested under static conditions for their bactericidal effects against gram-negative bacteria Escherichia coli (E. coli. The coated substrates were immersed into a suspension of E. coli in physiological solution for 24 and 4 hours. The basic titania coatings with no silver demonstrated no bactericidal properties. Very good bactericidal effect against E. coli in both types of bactericidal test showed the titania coatings with AgNO3, Ag3PO4 crystals and Ag3PO4 developed in situ.

  8. Preparation of carbon coated Fe3O4 nanoparticles for magnetic separation of uranium

    Science.gov (United States)

    Zhang, Xiaofei; Wang, Jun

    2018-01-01

    Uranium(VI) was removed from aqueous solutions using carbon coated Fe3O4 nanoparticles (Fe3O4@C). Batch experiments were conducted to study the effects of initial pH, shaking time and temperature on uranium sorption efficiency. It was found that the maximum adsorption capacity of the Fe3O4@C toward uranium(VI) was ∼120.20 mg g-1 when the initial uranium(VI) concentration was 100 mg L-1, displaying a high efficiency for the removal of uranium(VI) ions. Kinetics of the uranium(VI) removal is found to follow pseudo-second-order rate equation. In addition, the uranium(VI)-loaded Fe3O4@C nanoparticles can be recovered easily from aqueous solution by magnetic separation and regenerated by acid treatment. Present study suggested that magnetic Fe3O4@C composite particles can be used as an effective and recyclable adsorbent for the removal of uranium(VI) from aqueous solutions.

  9. Preparation and properties of natural rubber reinforced with polydopamine-coating modified carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Y-L. Lu

    2017-01-01

    Full Text Available Multi-walled carbon nanotubes (MWCNTs were functionalized by polydopamine (PDA-coating and mixed with natural rubber (NR via latex compounding. Compared with pristine MWCNTs, the surface of MWCNT-PDA was covered by an amorphous and nanometer-scale PDA layer which had a large amount of oxygenic and nitric functional groups. So the MWCNT-PDA showed a perfect dispersion in NR matrix. The tensile strength of NR/MWCNT-PDA (5 phr composites is 28.6 MPa, compared with the pure NR, which increased by 42%. For the electrical properties, when the content of MWCNTPDA or MWCNTs is 2 phr, the volume resistivity of NR/MWCNT-PDA composites falls to about 2.7·109 Ω·cm, compared with 3.3·1013 Ω·cm of NR/MWCNT composites. The thermal conductivity of NR composites increased only by 28.2% when 5 phr MWCNT-PDA was added. A model proposed by Nan was used to calculate the thermal conductivity of NR/MWCNT composites, and the calculated values were compared with the experimental values, the results showed that the interface thermal resistance is the main reason why MWCNTs could not significantly increase the thermal conductivity of natural rubber.

  10. Fabrication and properties of zinc oxide thin film prepared by sol-gel dip coating method

    Directory of Open Access Journals (Sweden)

    Kayani Zohra Nazir

    2015-09-01

    Full Text Available ZnO thin films were deposited on a glass substrate by dip coating technique using a solution of zinc acetate, ethanol and distilled water. Optical constants, such as refractive index n and extinction coefficient k. were determined from transmittance spectrum in the ultraviolet-visible-near infrared (UV-Vis-NIR regions using envelope methods. The films were found to exhibit high transmittance, low absorbance and low reflectance in the visible regions. Absorption coefficient α and the thickness of the film t were calculated from interference of transmittance spectra. The direct optical band gap of the films was in the range of 3.98 to 3.54 eV and the thickness of the films was evaluated in the range of 173 to 323 nm, while the refractive index slightly varied in the range of 1.515 to 1.622 with an increase in withdrawal speed from 100 to 250 mm/s. The crystallographic structure of the films was analyzed with X-ray diffractometer. The films were amorphous in nature.

  11. Effect of copper content on the properties of electroless Ni–Cu–P coatings prepared on magnesium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Junjun [Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Wang, Xudong, E-mail: xdwang@ustb.edu.cn [Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Tian, Zhiyong [China Special Equipment Inspection and Research Institute, Beijing 100013 (China); Yuan, Ming; Ma, Xijuan [Shandong Aerospace Electro-technology Institute, Yantai 264670 (China)

    2015-11-30

    Highlights: • Electroless Ni–Cu–P coatings were obtained on ZK61M magnesium alloys. • The crystallinity and compactness increases with the increasing of copper content. • The introduction of copper element in the coatings contributes to the formation of passivation film. • The coatings with higher corrosion resistance were obtained from the solution with a higher CuSO{sub 4} concentration. - Abstract: The Ni–Cu–P coatings were obtained by electroless plating method on ZK61M magnesium alloys. The effect of copper content on the properties of electroless Ni–Cu–P coatings on magnesium alloys was further studied. The coatings surface and cross-section morphologies were observed with scanning electron microscope. The crystal structure and corrosion resistance of Ni–Cu–P coatings were evaluated by X-ray diffractometer and electrochemical tests. The experimental results showed that the Ni–Cu–P coatings were uniform and compact, and the corrosion resistance of these coatings was superior to Ni–P coatings owing to the introduction of copper. The crystallinity and compactness of the Ni–Cu–P coatings gradually enhanced with the increasing of copper content in the coatings. The introduction of copper element in the Ni–Cu–P coatings contributes to the formation of passivation film. The Ni–Cu–P coatings with higher corrosion resistance were obtained from the solution with a higher CuSO{sub 4} concentration.

  12. New catalyst supports prepared by surface modification of graphene- and carbon nanotube structures with nitrogen containing carbon coatings

    Science.gov (United States)

    Oh, Eun-Jin; Hempelmann, Rolf; Nica, Valentin; Radev, Ivan; Natter, Harald

    2017-02-01

    We present a new and facile method for preparation of nitrogen containing carbon coatings (NCC) on the surface of graphene- and carbon nanotubes (CNT), which has an increased electronic conductivity. The modified carbon system can be used as catalyst support for electrocatalytic applications, especially for polymer electrolyte membrane fuel cells (PEMFC). The surface modification is performed by impregnating carbon structures with a nitrogen containing ionic liquid (IL) with a defined C:N ratio, followed by a thermal treatment under ambient conditions. We investigate the influence of the main experimental parameters (IL amount, temperature, substrate morphology) on the formation of the NCC. Additionally, the structure and the chemical composition of the resulting products are analyzed by electron microscopic techniques (SEM, TEM), energy disperse X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS) and hot extraction analysis. The modified surface has a nitrogen content of 29 wt% which decreases strongly at temperatures above 600 °C. The new catalyst supports are used for the preparation of PEMFC anodes which are characterized by polarization measurements and electrochemical impedance spectroscopy (EIS). Compared to unmodified graphene and CNT samples the electronic conductivity of the modified systems is increased by a factor of 2 and shows improved mass transport properties.

  13. Preparation of sustained-release coated particles by novel microencapsulation method using three-fluid nozzle spray drying technique.

    Science.gov (United States)

    Kondo, Keita; Niwa, Toshiyuki; Danjo, Kazumi

    2014-01-23

    We prepared sustained-release microcapsules using a three-fluid nozzle (3N) spray drying technique. The 3N has a unique, three-layered concentric structure composed of inner and outer liquid nozzles, and an outermost gas nozzle. Composite particles were prepared by spraying a drug suspension and an ethylcellulose solution via the inner and outer nozzles, respectively, and mixed at the nozzle tip (3N-PostMix). 3N-PostMix particles exhibited a corrugated surface and similar contact angles as ethylcellulose bulk, thus suggesting encapsulation with ethylcellulose, resulting in the achievement of sustained release. To investigate the microencapsulation process via this approach and its usability, methods through which the suspension and solution were sprayed separately via two of the four-fluid nozzle (4N) (4N-PostMix) and a mixture of the suspension and solution was sprayed via 3N (3N-PreMix) were used as references. It was found that 3N can obtain smaller particles than 4N. The results for contact angle and drug release corresponded, thus suggesting that 3N-PostMix particles are more effectively coated by ethylcellulose, and can achieve higher-level controlled release than 4N-PostMix particles, while 3N-PreMix particles are not encapsulated with pure ethylcellulose, leading to rapid release. This study demonstrated that the 3N spray drying technique is useful as a novel microencapsulation method. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. The effects of solvents on the properties of ultra-thin poly (methyl methacrylate) films prepared by spin coating

    Energy Technology Data Exchange (ETDEWEB)

    Tippo, T. [Faculty of Engineering, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520 (Thailand); Thanachayanont, C.; Muthitamongkol, P.; Junin, C. [National Metal and Materials Technology Center, Thailand Science Park, Klong 1, KlongLuang, Pathumthani 12120 (Thailand); Hietschold, M. [Chemnitz University of Technology, Institute of Physics, Solid Surface Analysis Group, D-09107 Chemnitz (Germany); Thanachayanont, A., E-mail: ktapinun@kmitl.ac.th [Faculty of Engineering, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520 (Thailand)

    2013-11-01

    Poly (methyl methacrylate) (PMMA) is extensively used as an insulating layer in organic electronic devices. In this study, spin coating method was used to cast thin layers of PMMA for dielectric application from solutions in three different solvents, namely dimethylformamide (DMF), n-butyl acetate and toluene. The solvent's vapor pressure causes the solvent to vaporize at different rates leading to layer's distortion and different surface roughnesses. Preparation of suitable surface morphologies, for example, pinhole-free and crack-free was studied. A step profilometer was used to measure the film thicknesses. Alternatively an equation correlating final film thickness to spin speed and solution concentration was proposed. A metal/insulator/metal parallel plate capacitor structure was fabricated and the current density dependence on the applied electric field was measured. The resulting low surface roughness, low leakage currents, high breakdown voltage, and high dielectric constant were obtained for the 100 nm-thick PMMA film prepared with DMF. - Highlights: • Solvent effect on quality of poly (methyl methacrylate) films • Thickness, surface morphology, and electrical properties were studied. • Best surface morphology and electrical properties obtained using dimethylformamide.

  15. Optical and structural properties of nanostructured copper oxide thin films as solar selective coating prepared by spray pyrolysis method

    Directory of Open Access Journals (Sweden)

    Asadi M.

    2017-07-01

    Full Text Available Copper (II oxide thin films were prepared by spray pyrolysis method on soda-lime glass substrates using copper acetate precursor solution. Influence of substrate temperature on structural and optical properties was investigated. Structural analysis of these layers were carried out by X-ray diffraction (XRD. Single phase nature and high crystallinity of CuO nanostructures were observed on XRD patterns. The general appearance of the films was uniform and black in color. FT-IR transmittance spectra confirmed the results from the XRD study. Selective solar absorber coatings of copper oxide (CuO on stainless steel substrates was prepared by spray pyrolysis method. Effect of deposition temperature on optical properties of thin films was investigated. Optical parameters, absorbance (α and emittance (α were evaluated from reflectance data. It can be deduced that the porous structure, such as a light traps, can greatly enhance absorbance, while the composition, thickness and roughness of thin films can greatly influence the emissivity. Single phase nature and high crystallinity of CuO nanostructures were observed by XRD patterns. Solar absorbance of thin films were in the range of 85 % to 92 %.

  16. Preparation of visible-light-responsive TiO{sub 2} coatings using molten KNO{sub 3} treatment and their photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Liang [Tianjin Key Lab of Integrated Design and On-line Monitoring for Light Industry & Food Machinery and Equipment, Tianjin (China); College of Mechanical Engineering, Tianjin University of Science & Technology, No. 1038 Dagu Nanlu, Hexi District, Tianjin 300222 (China); College of Mechanical Engineering & Graduate School, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Guan, Sujun; Takaya, Shunsuke [College of Mechanical Engineering & Graduate School, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Yoshida, Hiroyuki [Chiba Industrial Technology Research Institute, 6-13-1, Tendai, Inage-ku, Chiba 263-0016 (Japan); Tochihara, Misako [JFE Techno-Research Corporation, No. 1 Kawasaki-cho, Chuo-ku, Chiba 260-0835 (Japan); Lu, Yun, E-mail: luyun@faculty.chiba-u.jp [College of Mechanical Engineering & Graduate School, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)

    2017-06-15

    Highlights: • Molten KNO{sub 3} treatment are used to prepare K-doped TiO{sub 2} photocatalyst coatings. • The coatings show good antibacterial activity even in absence of light. • The photocatalytic activity is increased with the amount increase of K-doping. • The good antibacterial activity should come from the doping and release of K ions. - Abstract: In this work, the process of mechanical coating followed by molten KNO{sub 3} treatment is given to prepare visible-light-responsive K{sup +}-doped TiO{sub 2}. X-ray diffraction (XRD), scanning electron spectroscopy (SEM), Energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) were conducted to characterize these TiO{sub 2} coatings. The results showed that K{sup +}-doped anatase TiO{sub 2}/Ti composite coatings formed after molten KNO{sub 3} treatment at elevated temperatures. Meanwhile, their photocatalytic degradation of methylene blue (MB) and the antibacterial activity against Escherichia coli (E. coli) was also studied. The visible-light-responsive photocatalytic activity of the coatings in MB degradation increased with increase of K{sup +} ions when holding temperature was raised from 673 to 773 K. An excellent antibacterial activity of the K{sup +}-doped TiO{sub 2}/Ti coatings against E. coli was also obtained even in absence of light. The antibacterial activity in dark should attribute to the release of K{sup +} ions from the coatings. The photocatalytic activity under visible-light irradiation should result from the absorption spectrum extension due to the doping of K{sup +} ions into the lattice of TiO{sub 2}.

  17. Preparation of bone-implants by coating hydroxyapatite nanoparticles on self-formed titanium dioxide thin-layers on titanium metal surfaces.

    Science.gov (United States)

    Wijesinghe, W P S L; Mantilaka, M M M G P G; Chathuranga Senarathna, K G; Herath, H M T U; Premachandra, T N; Ranasinghe, C S K; Rajapakse, R P V J; Rajapakse, R M G; Edirisinghe, Mohan; Mahalingam, S; Bandara, I M C C D; Singh, Sanjleena

    2016-06-01

    Preparation of hydroxyapatite coated custom-made metallic bone-implants is very important for the replacement of injured bones of the body. Furthermore, these bone-implants are more stable under the corrosive environment of the body and biocompatible than bone-implants made up of pure metals and metal alloys. Herein, we describe a novel, simple and low-cost technique to prepare biocompatible hydroxyapatite coated titanium metal (TiM) implants through growth of self-formed TiO2 thin-layer (SFTL) on TiM via a heat treatment process. SFTL acts as a surface binder of HA nanoparticles in order to produce HA coated implants. Colloidal HA nanorods prepared by a novel surfactant-assisted synthesis method, have been coated on SFTL via atomized spray pyrolysis (ASP) technique. The corrosion behavior of the bare and surface-modified TiM (SMTiM) in a simulated body fluid (SBF) medium is also studied. The highest corrosion rate is found to be for the bare TiM plate, but the corrosion rate has been reduced with the heat-treatment of TiM due to the formation of SFTL. The lowest corrosion rate is recorded for the implant prepared by heat treatment of TiM at 700 °C. The HA-coating further assists in the passivation of the TiM in the SBF medium. Both SMTiM and HA coated SMTiM are noncytotoxic against osteoblast-like (HOS) cells and are in high-bioactivity. The overall production process of bone-implant described in this paper is in high economic value. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Drosophila larvae lacking the bcl-2 gene, buffy, are sensitive to nutrient stress, maintain increased basal target of rapamycin (Tor signaling and exhibit characteristics of altered basal energy metabolism

    Directory of Open Access Journals (Sweden)

    Monserrate Jessica P

    2012-07-01

    Full Text Available Abstract Background B cell lymphoma 2 (Bcl-2 proteins are the central regulators of apoptosis. The two bcl-2 genes in Drosophila modulate the response to stress-induced cell death, but not developmental cell death. Because null mutants are viable, Drosophila provides an optimum model system to investigate alternate functions of Bcl-2 proteins. In this report, we explore the role of one bcl-2 gene in nutrient stress responses. Results We report that starvation of Drosophila larvae lacking the bcl-2 gene, buffy, decreases survival rate by more than twofold relative to wild-type larvae. The buffy null mutant reacted to starvation with the expected responses such as inhibition of target of rapamycin (Tor signaling, autophagy initiation and mobilization of stored lipids. However, the autophagic response to starvation initiated faster in larvae lacking buffy and was inhibited by ectopic buffy. We demonstrate that unusually high basal Tor signaling, indicated by more phosphorylated S6K, was detected in the buffy mutant and that removal of a genomic copy of S6K, but not inactivation of Tor by rapamycin, reverted the precocious autophagy phenotype. Instead, Tor inactivation also required loss of a positive nutrient signal to trigger autophagy and loss of both was sufficient to activate autophagy in the buffy mutant even in the presence of enforced phosphoinositide 3-kinase (PI3K signaling. Prior to starvation, the fed buffy mutant stored less lipid and glycogen, had high lactate levels and maintained a reduced pool of cellular ATP. These observations, together with the inability of buffy mutant larvae to adapt to nutrient restriction, indicate altered energy metabolism in the absence of buffy. Conclusions All animals in their natural habitats are faced with periods of reduced nutrient availability. This study demonstrates that buffy is required for adaptation to both starvation and nutrient restriction. Thus, Buffy is a Bcl-2 protein that plays an

  19. Ultra-high pressure water jetting for coating removal and surface preparation

    Science.gov (United States)

    Johnson, Spencer T.

    1995-01-01

    This paper shall examine the basics of water technology with particular attention paid to systems currently in use and some select new applications. By providing an overview of commercially available water jet systems in the context of recent case histories, potential users may evaluate the process for future applications. With the on going introduction of regulations prohibiting the use of chemical paint strippers, manual scrapping and dry abrasive media blasting, the need for an environmentally compliant coating removal process has been mandated. Water jet cleaning has been a traditional part of many industrial processed for year, although it has only been in the last few years that reliable pumping equipment capable of ultra-high pressure operation have become available. With the advent of water jet pumping equipment capable of sustaining pressures in excess of 36,000 psi. there has been shift away from lower pressure, high water volume systems. One of the major factors in driving industry to seek higher pressures is the ability to offer higher productivity rates while lowering the quantity of water used and subsequently reprocessed. Among benefits of the trend toward higher pressure/lower volume systems is the corresponding reduction in water jet reaction forces making hand held water jetting practical and safe. Other unique applications made possible by these new generation pumping systems include the use of alternative fluids including liquid ammonia for specialized and hazardous material removal applications. A review of the equipment used and the required modifications will be presented along with the conclusions reached reached during this test program.

  20. Compression forces and amount of outer coating layer affecting the time-controlled disintegration of the compression-coated tablets prepared by direct compression with micronized ethylcellulose.

    Science.gov (United States)

    Lin, K H; Lin, S Y; Li, M J

    2001-12-01

    The influence of compression force to inner core tablet or to outer coating layer of the compression-coated tablet on the function of time-controlled disintegration was investigated. The inner core tablet was directly compacted by sodium diclofenac (model drug) and ethylcellulose (EC) with 4.6-microm particle size was used as an outer coating layer. The immersion time of the compression-coated tablet previously soaked in pH 1.2 solution to simulate the residence time of the tablet in the GI tract affecting the dissolution behavior of the compression-coated tablet was also investigated. The effect of the amount of the outer coating layer used on the drug release was examined. The results indicate that sodium diclofenac released from these compression-coated tablets exhibited a longer lag of a period about 16.3 h in both distilled water and pH 6.8 buffer solution, followed by a different drug release behavior. The lag time was independent of the pH of dissolution medium, and the immersion time in pH 1.2 solution. After that lag time, the outer shell of the compression-coated tablets broke into two halves to make a rapid drug release. However, the drug release behavior of the soaked tablet in pH 6.8 buffer solution was dependent on the immersion time. The compression force tablet influenced the release behavior of drug less, but > 200 kg/cm(2) might delay the lag time. The lag time of the compression-coated tablets was linearly correlated with the compression force to the outer coating layer (r = 0.9896). We also found that the more the amount of outer coating layer added, the longer the lag time obtained. The study demonstrates that the time-controlled disintegration of the compression-coated tablet was effectively controlled by the compression force applied and the amount of outer coating layer added. Copyright 2001 Wiley-Liss, Inc. and the American Pharmaceutical Association

  1. High-temperature Corrosion Resistance of Composite Coating Prepared by Micro-arc Oxidation Combined with Pack Cementation Aluminizing

    Directory of Open Access Journals (Sweden)

    HUANG Zu-jiang

    2018-01-01

    Full Text Available Al2O3 ceramic film was obtained by micro-arc oxidation (MAO process on Al/C103 specimen, which was prepared by pack cementation aluminizing technology on C103 niobium alloy. With the aid of XRD and SEM equipped with EDS, chemical compositions and microstructures of the composite coatings before and after high-temperature corrosion were analyzed. The behavior and mechanism of the composite coatings in high-temperature oxidation and hot corrosion were also investigated. The results indicate that oxidation mass gain at 1000℃ for 10h of the Al/C103 specimen is 6.98mg/cm2, and it is 2.89mg/cm2 of the MAO/Al/C103 specimen. However, the mass gain of MAO/Al/C103 specimen (57.52mg/cm2 is higher than that of Al/C103 specimen (28.08mg/cm2 after oxidation 20h. After hot corrosion in 75%Na2SO4 and 25%NaCl at 900℃ for 50h, the mass gain of Al/C103 and MAO/Al/C103 specimens are 70.54mg/cm2 and 55.71mg/cm2 respectively, Al2O3 and perovskite NaNbO3 phases are formed on the surface; the diffusion of molten salt is suppressed, due to part of NaNbO3 accumulated in the MAO micropores. Therefore, MAO/Al/C103 specimen exhibits better hot corrosion resistance.

  2. Preparation of enteric-coated microcapsules of astaxanthin oleoresin by complex coacervation.

    Science.gov (United States)

    Li, Rongli; Chen, Rencai; Liu, Weiwei; Qin, Cuiying; Han, Jing

    2016-10-25

    Astaxanthin oleoresin (AO) has a number of beneficial physiological functions. However, its sensitivity to light, heat, oxygen and gastric fluids has limited its application. In this paper, we describe the preparation of AO enteric microcapsules by coacervation to improve its stability and enteric solubility, and evaluate their efficacy by measuring the drug loading, encapsulation efficiency, optical microscopic appearance, stability, in vitro release and bioavailability. The results obtained showed that the AO enteric microcapsules possessed a high encapsulation efficiency (85.9%), a satisfactory in vitro release profile, and the ability of the microencapsulated AO to resist the effects of light, heat and oxygen was improved by 2.2-fold, 3.1-fold and 2.4-fold, respectively, during storage. In addition, the bioavailability of AO microcapsules was approximately 1.29-fold higher than AO, which is important for pharmaceutical applications and as a functional food.

  3. Advanced anticorrosive coatings prepared from electroactive polyimide/graphene nanocomposites with synergistic effects of redox catalytic capability and gas barrier properties

    Directory of Open Access Journals (Sweden)

    J. M. Yeh

    2014-04-01

    Full Text Available In this study, electroactive polyimide (EPI/graphene nanocomposite (EPGN coatings were prepared by thermal imidization and then characterized by Fourier transformation infrared (FTIR and transmission electron microscope (TEM. The redox behavior of the as-prepared EPGN materials was identified by in situ monitoring for cyclic voltammetry (CV studies. Demonstrating that EPGN coatings provided advanced corrosion protection of cold-rolled steel (CRS electrodes as compared to that of neat EPI coating. The superior corrosion protection of EPGN coatings over EPI coatings on CRS electrodes could be explained by the following two reasons. First, the redox catalytic capabilities of amino-capped aniline trimer (ACAT units existing in the EPGN may induce the formation of passive metal oxide layers on the CRS electrode, as indicated by scanning electron microscope (SEM and electron spectroscopy for chemical analysis (ESCA studies. Moreover, the well-dispersed carboxyl-graphene nanosheets embedded in the EPGN matrix hinder gas migration exponentially. This would explain enhanced oxygen barrier properties of EPGN, as indicated by gas permeability analysis (GPA studies.

  4. In Situ Carbon Coated LiNi0.5Mn1.5O4 Cathode Material Prepared by Prepolymer of Melamine Formaldehyde Resin Assisted Method

    Directory of Open Access Journals (Sweden)

    Wei Yang

    2016-01-01

    Full Text Available Carbon coated spinel LiNi0.5Mn1.5O4 were prepared by spray-drying using prepolymer of melamine formaldehyde resin (PMF as carbon source of carbon coating layer. The PMF carbon coated LiNi0.5Mn1.5O4 was characterized by XRD, SEM, and other electrochemical measurements. The as-prepared lithium nickel manganese oxide has the cubic face-centered spinel structure with a space group of Fd3m. It showed good electrochemical performance as a cathode material for lithium ion battery. After 100 discharge and charge cycles at 0.5 C rate, the specific discharge capacity of carbon coated LiNi0.5Mn1.5O4 was 130 mAh·g−1, and the corresponding capacity retention was 98.8%. The 100th cycle specific discharge capacity at 10 C rate of carbon coated LiNi0.5Mn1.5O4 was 105.4 mAh·g−1, and even the corresponding capacity retention was 95.2%.

  5. Preparation of Controlled-Release Particles Based on Spherical Porous Silica Used as the Drug Carrier by the Dry Coating Method.

    Science.gov (United States)

    Nakamura, Shohei; Kondo, Shihoko; Mohri, Ayaka; Sakamoto, Takatoshi; Yuasa, Hiroshi

    2018-02-12

    A controlled-release formulation is a dosage form that could improve a patient's quality of life by reducing the frequency of administration, while ensuring the continued effect of the medicine and reducing the side effects. To prepare these controlled-release particles, a wet coating method in which a drug is coated with a controlled-release material using water or an organic solvent is used, but with this method, the coating process is very time-consuming and requires large amounts of energy for the drying phase. In addition, contact with water or an organic solvent may cause problems such as alteration of the drug. Therefore, the use of a dry coating method has attracted attention as a means of overcoming these issues. However, since the drug is fixed to the surface of a core particle, it is necessary to further coat it with a water-soluble material. We used spherical porous silica (SPS) particles, considering that the drug fixation via a water-soluble material would not be necessary if the drug were to be placed in the pores of these particles. We used SPS filled with theophylline (TP), a model drug, as the core particles. To prepare controlled-release particles (CRP), a controlled-release layer consisting of hydrogenated castor oil (HCO) was applied to the core particle surface by a dry coating method. The paddle method using 1% w/v polysorbate 80 solution as the test medium was employed to estimate the TP dissolution rate of the resulting CRPs. The 50% dissolution time of TP extended from 14 to 405 min with increasing the amount of the coated HCO. The Korsmeyer-Peppas model applied to the TP dissolution behavior yielded an n value of around 1. Moreover, the K value was comparable with the case in which a zero-order model was applied. It is thought that the dissolution of TP from CRPs will conform to the zero-order model.

  6. Preparation and tribological properties of self-lubricating TiO2/graphite composite coating on Ti6Al4V alloy

    Science.gov (United States)

    Mu, Ming; Zhou, Xinjian; Xiao, Qian; Liang, Jun; Huo, Xiaodi

    2012-09-01

    One-step plasma electrolytic oxidation (PEO) process in a graphite-dispersed phosphate electrolyte was used to prepare a graphite-containing oxide composite coating on Ti6Al4V alloy. The composition and microstructure of the oxide coatings produced in the phosphate electrolytes with and without addition of graphite were analyzed by X-ray diffractometer (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The tribological properties of the uncoated Ti6Al4V alloy and oxide coatings were evaluated using a reciprocating ball-on-disk tribometer. Results showed that the graphite-containing oxide composite coating can be successfully produced on Ti6Al4V alloy in the graphite-dispersed phosphate electrolyte using PEO process. The graphite-containing oxide composite coating registered much lower friction coefficient and wear rate than the uncoated Ti6Al4V alloy and the oxide coating without graphite under dry sliding condition, exhibiting excellent self-lubricating property.

  7. Preparation of the antithrombotic and antimicrobial coating through layer-by-layer self-assembly of nattokinase-nanosilver complex and polyethylenimine.

    Science.gov (United States)

    Wei, Xuetuan; Luo, Mingfang; Liu, Huizhou

    2014-04-01

    The bifunctional coating with antithrombotic and antimicrobial activity was developed using nattokinase (NK) and nanosilver (AgNPs). Firstly, the adsorption interactions between NK and AgNPs were confirmed, and the composite particles of NK-AgNPs were prepared by adsorption of NK with AgNPs. At 5FU/mL of NK concentration, the saturation adsorption capacity reached 24.35 FU/mg AgNPs with a high activity recovery of 97%, and adsorption by AgNPs also enhanced the heat stability and anticoagulant effect of NK. Based on the electrostatic force driven layer-by-layer self-assembly, the NK-AgNPs were further assembled with polyethylenimine (PEI) to form coating. UV-vis analysis showed that the self-assembly process was regular, and atom force microscopy analysis indicated that NK-AgNPs were uniformly embedded into the coating. The NK-AgNPs-PEI composite coating showed potent antithrombotic activity and antibacterial activity. This study developed a novel strategy to construct the bifunctional coating with antithrombotic and antimicrobial properties, and the coating material showed promising potential to be applied in the medical device. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Preparation and Surface Modification of Silica ‎Nanoparticles for Superhydrophopic Coating

    Directory of Open Access Journals (Sweden)

    Noor Hadi Aysa

    2017-12-01

    Full Text Available Silica  nanoparticles are well-known to be one of the multifunctional inorganic compounds which are widely used in medical applications. The aim of this study is to prepare the particles of nano silica oxide with particle size ranging from 20-25  nm. In the present study, surface modification of Silica nanoparticles was performed, and influence of modification on the structure and morphological properties was investigated. The resulting  nanoparticles were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM and atomic force microscopy (AFM.  Silica nanoparticles with the average diameter of about 20 nm were modified with oleic acid, as coupling agents, in order to modify their surface properties and make them more waterproof  dispersible in the organic area. Among the results is that the  surface modification of the   Silica nano-particles leads to more dispersion in the organic medium which indicates better organic synthesis.  One of the results obtained, is that modified silica-nanoparticles can be used effectively in environmental and safety applications and can be used in future medical applications as wound stick that prevent water from reaching the wound and then prevent  an inflamation

  9. Polymer solar cell modules prepared using roll-to-roll methods: Knife-over-edge coating, slot-die coating and screen printing

    DEFF Research Database (Denmark)

    Krebs, Frederik C

    2009-01-01

    -nm layer of transparent conducting indium–tin oxide (ITO). The ITO layer was first patterned by screen printing an etch resist followed by etching. The second layer was applied by either knife-over-edge (KOE) coating or slot-die coating a solution of zinc oxide nanoparticles (ZnO-nps) followed...... by curing. The second layer comprised a mixture of the thermocleavable poly-(3-(2-methylhexan-2-yl)-oxy-carbonyldithiophene) (P3MHOCT) and ZnO-nps and was applied by a modified slot-die coating procedure, enabling slow coating speeds with low viscosity and low surface tension ink solutions. The third layer...... was patterned into stripes and juxtaposed with the ITO layer. The fourth layer comprised screen-printed or slot-die-coated PEDOT:PSS and the fifth and the final layer comprised a screen-printed or slot-die-coated silver electrode. The final module dimensions were 28 cm×32 cm and presented four individual solar...

  10. Effect of copper content on the properties of electroless Ni-Cu-P coatings prepared on magnesium alloys

    Science.gov (United States)

    Liu, Junjun; Wang, Xudong; Tian, Zhiyong; Yuan, Ming; Ma, Xijuan

    2015-11-01

    The Ni-Cu-P coatings were obtained by electroless plating method on ZK61M magnesium alloys. The effect of copper content on the properties of electroless Ni-Cu-P coatings on magnesium alloys was further studied. The coatings surface and cross-section morphologies were observed with scanning electron microscope. The crystal structure and corrosion resistance of Ni-Cu-P coatings were evaluated by X-ray diffractometer and electrochemical tests. The experimental results showed that the Ni-Cu-P coatings were uniform and compact, and the corrosion resistance of these coatings was superior to Ni-P coatings owing to the introduction of copper. The crystallinity and compactness of the Ni-Cu-P coatings gradually enhanced with the increasing of copper content in the coatings. The introduction of copper element in the Ni-Cu-P coatings contributes to the formation of passivation film. The Ni-Cu-P coatings with higher corrosion resistance were obtained from the solution with a higher CuSO4 concentration.

  11. Preparation of Phytic Acid/Silane Hybrid Coating on Magnesium Alloy and Its Corrosion Resistance in Simulated Body Fluid

    Science.gov (United States)

    Wang, Fengwu; Cai, Shu; Shen, Sibo; Yu, Nian; Zhang, Feiyang; Ling, Rui; Li, Yue; Xu, Guohua

    2017-09-01

    In order to decrease the corrosion rate and improve the bioactivity of magnesium alloy, phytic acid/saline hybrid coatings were synthesized on AZ31 magnesium alloys by sol-gel dip-coating method. It was found that the mole ratio of phytic acid to γ-APS had a great influence on coating morphology and the corresponding corrosion resistance of the coated magnesium alloys. When the mole ratio of phytic acid to γ-APS was 1:1, the obtained hybrid coating was integral and without cracks, which was ascribed to the strong chelate capability of phytic acid and Si-O-Si network derived from silane. Electrochemical test result indicated that the corrosion resistance of the coated magnesium alloy was about 27 times larger than that of the naked counterpart. In parallel, immersion test showed that the phytic acid/silane hybrid coating could induce CaP-mineralized product deposition, which offered another protection for magnesium alloy.

  12. Structural evolution and optical properties of C-coated TiO2 nanoparticles prepared by laser pyrolysis

    Science.gov (United States)

    Scarisoreanu, M.; Alexandrescu, R.; Morjan, I.; Birjega, R.; Luculescu, C.; Popovici, E.; Dutu, E.; Vasile, E.; Danciu, V.; Herlin-Boime, N.

    2013-08-01

    Carbon- coated TiO2 nanoparticles were prepared by the IR laser pyrolysis technique. A sensitized mixture of TiCl4 and alternatively C2H4 and C2H4/C2H2 mixtures were used as titanium and carbon precursors, respectively. Optical, morphological and structural properties of the samples have been characterized by X-ray diffraction, transmission electron microscopy, high-resolution electron microscopy, selected area electron diffraction analysis and UV-vis diffuse reflectance spectroscopy. The phase composition of the nanoparticle system contains a mixture of anatase and rutile, with a preponderance of the anatase phase (90%) and with mean particle size of about 20 nm. The effect of increased carbon-dopant concentration on the essential structural properties of C-TiO2 nanopowders has been determined to be a decrease of the TiO2 anatase phase and of the particle mean diameter value (to about 18 nm). For the C-doped TiO2 nanoparticles, the UV-vis diffuse reflectance spectra showed an absorption shift to longer wavelengths, thus demonstrating an enhancement of the absorption in the visible spectrum.

  13. Structural evolution and optical properties of C-coated TiO{sub 2} nanoparticles prepared by laser pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Scarisoreanu, M., E-mail: monica.scarisoreanu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, POB MG-36, Bucharest 077125 (Romania); Alexandrescu, R.; Morjan, I.; Birjega, R.; Luculescu, C.; Popovici, E.; Dutu, E. [National Institute for Lasers, Plasma and Radiation Physics, POB MG-36, Bucharest 077125 (Romania); Vasile, E. [Metav, Research and Development, 31C.A. Rosetti Str, 020011, Bucharest (Romania); Danciu, V. [Babes-Boyai University, Faculty of Chemistry and Chemical Engineering, Electrochemical Research Laboratory, 11 Arany Janos Str, Cluj- Napoca, 400028 (Romania); Herlin-Boime, N. [Laboratoire Francis Perrin URA 2453 CEA-CNRS-IRAMIS, 91191 Gif-sur-Yvette (France)

    2013-08-01

    Carbon- coated TiO{sub 2} nanoparticles were prepared by the IR laser pyrolysis technique. A sensitized mixture of TiCl{sub 4} and alternatively C{sub 2}H{sub 4} and C{sub 2}H{sub 4}/C{sub 2}H{sub 2} mixtures were used as titanium and carbon precursors, respectively. Optical, morphological and structural properties of the samples have been characterized by X-ray diffraction, transmission electron microscopy, high-resolution electron microscopy, selected area electron diffraction analysis and UV–vis diffuse reflectance spectroscopy. The phase composition of the nanoparticle system contains a mixture of anatase and rutile, with a preponderance of the anatase phase (90%) and with mean particle size of about 20 nm. The effect of increased carbon-dopant concentration on the essential structural properties of C-TiO{sub 2} nanopowders has been determined to be a decrease of the TiO{sub 2} anatase phase and of the particle mean diameter value (to about 18 nm). For the C-doped TiO{sub 2} nanoparticles, the UV–vis diffuse reflectance spectra showed an absorption shift to longer wavelengths, thus demonstrating an enhancement of the absorption in the visible spectrum.

  14. Biocompatibility of Nanoporous TiO2 Coating on NiTi Alloy Prepared via Dealloying Method

    Directory of Open Access Journals (Sweden)

    Jin Huang

    2012-01-01

    Full Text Available This paper investigated the biocompatibility of nanoporous TiO2 coating on NiTi shape-memory alloy (SMA prepared via dealloying method. Our previous study shows that the dealloying treatment at low temperature leads to 130 nm Ni-free surface titania surface layer, which possesses good bioactivity because of the combination of hydroxyl (OH− group in the process of dealloying treatment simultaneously. In this paper, the biological compatibility of NiTi alloy before and after dealloying treatment was evaluated and compared by direct contact method with dermal mesenchymal stem cells (DMSCs by the isolated culture way. The interrelation between the biological compatibility and surface change of material after modification was systematically analyzed. As a consequence, the dealloying treatment method at low temperature could be of interest for biomedical application, as it can avoid sensitization and allergies and improve biocompatibility of NiTi shape-memory alloys. Thus it laid the foundation of the clinical trials for surface modification of NiTi memory alloy.

  15. Preparation and characterization of VO₂(M)-SnO₂ thermochromic films for application as energy-saving smart coatings.

    Science.gov (United States)

    Li, Wenjing; Ji, Shidong; Qian, Kun; Jin, Ping

    2015-10-15

    Novel VO2(M)/SnO2 heterostructured nanorods are prepared by combining the conventional hydrothermal synthesis method and post annealing process. The results reveal that the nanosized SnO2 particles are not only successfully grown on the surface of the VO2 nanorods but also uniformly distribute on VO2 without aggregation. The existence of the SnO2 nanoparticles inhibits the aggregation during the annealing process and widens the band gap of the VO2 crystals from 0.75 to 1.7 eV. The two aspects can both improve the optical properties of the VO2(M)/SnO2 composite film. The visible transmittance is up to 35.7% and the IR modulation at 2500 nm is more than 56%, which were much higher than the pure VO2(M) film. In addition, the SnO2 layer could reduce the width of the hysteresis from 17.8 to 10.7°C caused by Sn-doping and enhance the sensitivity. We believe that the VO2(M)/SnO2 heterostructured coating is a good candidate for smart windows. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Nanomechanical properties of TiCN and TiCN/Ti coatings on Ti prepared by Filtered Arc Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yong [School of Mechanical, Materials & Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Lu, Cheng, E-mail: chenglu@uow.edu.au [School of Mechanical, Materials & Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Yu, Hailiang [School of Mechanical, Materials & Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); School of Mechanical Engineering, Shenyang University, Shenyang 110044 (China); Kiet Tieu, A.; Su, Lihong; Zhao, Yue; Zhu, Hongtao [School of Mechanical, Materials & Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Kong, Charlie [Electron Microscope Unit, University of New South Wales, Sydney, NSW 2052 (Australia)

    2015-02-11

    Monolayer TiCN and multilayer TiCN/Ti coatings were deposited on the surface of Ti using the Filtered Arc Deposition System (FADS). Nanoindentation tests were performed on both coatings. The multilayer TiCN/Ti coating exhibited better ductility than the monolayer TiCN coating. The lattice constants of the coatings were characterized by X-ray diffraction. Transmission Electron Microscopy (TEM) was used to investigate the fracture behavior of the coatings. Inter-columnar, inclined and lateral cracks were found to be the dominant crack modes in the monolayer TiCN coatings while small bending crack and radial crack were the dominant crack modes in the multilayer TiCN/Ti coatings. The Finite Element Method (FEM) was used to simulate the indentation process. It was found that the Ti interlayer in the multilayer TiCN/Ti coating could efficiently suppress the fracture, which is responsible for the improved ductility of the multilayer TiCN/Ti coating.

  17. Effect of liquid oil additive on lithium-ion battery ceramic composite separator prepared with an aqueous coating solution

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Woo [Division of Advanced Materials Engineering, Kongju National University, 1223–24, Cheonan-daero, Cheonan, Chungnam, 31080 (Korea, Republic of); Ryou, Myung-Hyun [Department of Chemical & Biological Engineering, Hanbat National University, 125, Dongseodaero, Yuseong-gu, Daejeon, 34158 (Korea, Republic of); Lee, Yong Min, E-mail: yongmin.lee@hanbat.ac.kr [Department of Chemical & Biological Engineering, Hanbat National University, 125, Dongseodaero, Yuseong-gu, Daejeon, 34158 (Korea, Republic of); Cho, Kuk Young, E-mail: kycho@hanyang.ac.kr [Department of Materials Science and Chemical Engineering, Hanyang University, 55, Hanyangdaehak-ro, Sangrok-gu, Ansan, Gyeonggi-do, 15588 (Korea, Republic of)

    2016-08-05

    Ceramic composite separators (CCSs) play a critical role in ensuring safety for lithium-ion batteries (LIBs), especially for mid- and large-sized devices. However, production of CCSs using organic solvents has some cost and environmental concerns. An aqueous process for fabricating CCSs is attractive because of its cost-effectiveness and environmental-friendliness because organic solvents are not used. The success of an aqueous coating system for LIBs is dependent upon minimizing moisture content, as moisture has a negatively impact on LIB performance. In this study, CCSs were fabricated using an aqueous coating solution containing Al{sub 2}O{sub 3} and an acrylic binder. Compared with polyethylene (PE) separators, CCSs coated with an aqueous coating solution showed improved thermal stability, electrolyte uptake, puncture strength, ionic conductivity, and rate capability. In addition, our new approach of introducing a small amount of an oily liquid to the aqueous coating solution reduced the water adsorption by 11.7% compared with coatings that do not contain the oily liquid additive. - Highlights: • Ceramic composite separator is fabricated using aqueous coating process. • Coated separator showed enhanced mechanical and thermal stability. • Liquid oil additive in coating solution reduce moisture reabsorption of separator. • Oil additive in aqueous coating solution does not deteriorate LIB performance.

  18. Preparation and Characterization of Plasma Electrolytic Oxidation Coating on 5005 Aluminum Alloy with Red Mud as an Electrolyte Additive

    Science.gov (United States)

    Liu, Shifeng; Zeng, Jianmin; Wang, Youbin

    2017-10-01

    A coating with red mud as an electrolyte additive was applied to 5005 aluminum alloy using plasma electrolytic oxidation (PEO). The phase composition of the coating was investigated using X-ray diffraction. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) was used to determine the microstructure and composition profiles of the coating. The coating/substrate adhesion was determined by scratch testing. The corrosion behaviors of the substrate and coating were evaluated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The results indicated that the PEO coating with red mud consisted mainly of α-Al2O3 and γ-Al2O3, with small amounts of Fe2O3, CaCO3, and CaTiO3. The surface of the coating was the color of the red mud. The coating had a uniform thickness of about 80 μm and consisted of two main layers: a 6- μm porous outer layer and a 74- μm dense inner layer, which showed typical metallurgical adhesion (coating/substrate adhesion strength of 59 N). The coating hardness was about 1142 HV, much higher than that of the substrate (60 HV). The corrosion potential E corr and corrosion current density i corr of the coating were estimated to be -0.743 V and 3.85 × 10-6 A cm-2 from the PDP curve in 3.5 wt pct NaCl solution, and the maximum impedance and phase angle of the coating were 11 000 Ω and -67 deg, respectively, based on EIS. PEO coating with red mud improved the surface properties and corrosion resistance of 5005 aluminum alloy. This study also shows a potential method for reusing red mud.

  19. Composite films prepared by plasma ion-assisted deposition (IAD) for design and fabrication of antireflection coatings in visible and near-infrared spectral regions

    Science.gov (United States)

    Tsai, Rung-Ywan; Ho, Fang C.

    1994-11-01

    Ion-assisted deposition (IAD) processes configured with a well-controlled plasma source at the center base of a vacuum chamber, which accommodates two independent e-gun sources, is used to deposition TiO2MgF2 and TiO2-SiO2 composite films of selected component ratios. Films prepared by this technology are found durable, uniform, and nonabsorbing in visible and near-IR regions. Single- and multilayer antireflection coatings with refractive index from 1.38 to 2.36 at (lambda) equals 550 nm are presented. Methods of enhancement in optical performance of these coatings are studied. The advantages of AR coatings formed by TiO2-MgF2 composite films over those similar systems consisting of TiO2-SiO2 composite films in both visible and near-IR regions are also presented.

  20. Preparation and microwave-absorbing properties of silver-coated strontium ferrite with polyaniline via in situ polymerization

    Energy Technology Data Exchange (ETDEWEB)

    He, Zheng; Qi, Shuhua; Zhong, Xiaolan; Ma, Huan; Wang, Pei; Qiu, Hua

    2015-02-05

    Graphical abstract: Reflection losses of PANI (a), PANI/SrFe{sub 12}O{sub 19} (b) and PANI/Ag/SrFe{sub 12}O{sub 19} (c). - Highlights: • Preparation of a new type of electromagnetic particle and polymer compound. • The methods and process for preparation with detailed description and analysis. • The compound exhibited better thermal stability, conductivity and magnetic property than pure PANI. • The compound is an excellent candidate for application as a microwave absorber. - Abstract: In this contribution, a new type of conductive and magnetic PANI/Ag/SrFe{sub 12}O{sub 19} composites were synthesized via three-step method. First, SrFe{sub 12}O{sub 19} was synthesized through coprecipitation reaction, then Ag/SrFe{sub 12}O{sub 19} particles were prepared via chemical plating method. Finally, PANI/Ag/SrFe{sub 12}O{sub 19} composites were obtained by in-situ polymerization in the presence of Ag/SrFe{sub 12}O{sub 19.} The morphologies and properties of the samples were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), UV–Visible spectrophotometry (UV–Vis) and vibrating sample magnetometry (VSM). Results show that SrFe{sub 12}O{sub 19} and Ag/SrFe{sub 12}O{sub 19} particles are successfully synthesized. After coating Ag on SrFe{sub 12}O{sub 19} surface, the saturation magnetization of particles decrease from 117.22 emu/g to 70.54 emu/g, whereas its conductivity increase to 107 S/cm. Meanwhile, with the introduction of Ag/SrFe{sub 12}O{sub 19,} the PANI/Ag/SrFe{sub 12}O{sub 19} composites exhibit better thermal stability, electric and magnetic properties than pure PANI. Measurements of the reflection loss (R) show that PANI/Ag/SrFe{sub 12}O{sub 19} composites have a good microwave absorbing property in the X band, the reflection loss of the composites is below −10 dB between 8.7 GHz and 12.1 GHz, with a minimum loss value of −14.86 at 9.98 GHz.

  1. Preparation and properties of in-situ growth of carbon nanotubes reinforced hydroxyapatite coating for carbon/carbon composites.

    Science.gov (United States)

    Liu, Shoujie; Li, Hejun; Su, Yangyang; Guo, Qian; Zhang, Leilei

    2017-01-01

    Carbon nanotubes (CNTs) possess excellent mechanical properties for their role playing in reinforcement as imparting strength to brittle hydroxyapatite (HA) bioceramic coating. However, there are few reports relating to the in-situ grown carbon nanotubes reinforced hydroxyapatite (CNTs-HA) coating. Here we demonstrate the potential application in reinforcing biomaterials by an attempt to use in-situ grown of CNTs strengthen HA coating, using a combined method composited of injection chemical vapor deposition (ICVD) and pulsed electrodeposition. The microstructure, phases and chemical compositions of CNTs-HA coatings were characterized by various advanced methods. The scanning electron microscopy (SEM) images indicated that CNTs-HA coatings avoided the inhomogeneous dispersion of CNTs inside HA coating. The result show that the interfacial shear strength between CNTs-HA coating and the C/C composite matrix reaches to 12.86±1.43MPa. Potenitodynamic polarization and electrochemical impedance spectroscopy (EIS) studies show that the content of CNTs affects the corrosion resistance of CNTs-HA coating. Cell culturing and simulated body fluid test elicit the biocompatibility with living cells and bioactivity of CNTs-HA coatings, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Preparation and electrochemical properties of Li-rich spinel-type lithium manganate coated LiMn{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yumei; Lin, Zhenzhen [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Li, Yongliang [Analytical and Testing Center, Beijing Normal University, Beijing 100875 (China); Chen, Caifeng; He, Yi [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Yang, Xiaojing, E-mail: yang.xiaojing@bnu.edu.cn [College of Chemistry, Beijing Normal University, Beijing 100875 (China)

    2011-12-15

    Graphical abstract: Composites in which Li-rich spinel-type lithium manganate was coated on surface of LiMn{sub 2}O{sub 4} particles were prepared, and the cycling stabilities of composites were much improved. Highlights: Black-Right-Pointing-Pointer A composite of Li-rich spinel-type lithium manganate and LiMn{sub 2}O{sub 4}. Black-Right-Pointing-Pointer Li-rich spinel-type lithium manganate coating on the surface of LiMn{sub 2}O{sub 4} particles. Black-Right-Pointing-Pointer A synthetic method of sol-gel followed by heating. Black-Right-Pointing-Pointer Improved cycling stability without large degradation of initial capacity. -- Abstract: Li-rich spinel-type lithium manganate (SC) coated LiMn{sub 2}O{sub 4} composites were prepared and characterized by XRD, SEM, FT-IR, ICP, etc. Their charge/discharge behaviors were studied between 3.0 and 4.3 V at 40 mA g{sup -1} under room temperature, and the results showed that SC coated on surface of LiMn{sub 2}O{sub 4} could improve cycling stability of composite electrodes. The composite (S1) containing 4.8 wt% of SC exhibited noticeably improved cycling stability, whereas the initial specific capacity was very close to that of LiMn{sub 2}O{sub 4}.

  3. The Synthesis of Anatase Nanoparticles and the Preparation of Photocatalytically Active Coatings Based on Wet Chemical Methods for Self-Cleaning Applications

    Directory of Open Access Journals (Sweden)

    Dejan Verhovšek

    2012-01-01

    Full Text Available We report on an improved sol-gel method for the production of highly photocatalytic titanium dioxide (TiO2 anatase nanoparticles which can provide appropriate control over the final characteristics of the nanoparticles, such as particle size, crystallinity, crystal structure, morphology, and also the degree of agglomeration. The synthesized anatase nanoparticles were characterized using various techniques, such as X-ray powder diffraction (XRD, scanning electron microscopy (SEM, and transmission electron microscopy (TEM, and were tested in coatings for self-cleaning glass and ceramic surfaces. The coatings were prepared using a soft chemistry route and are completely transparent to visible light and exhibit a high photocatalytic effect, which was determined by contact-angle measurements. Finally, it is worth mentioning that both the sol-gel synthesis method and the coating-preparation method are based on a wet chemical process, thus presenting no risk of handling the TiO2 anatase nanoparticles in their potentially hazardous powder form at any stage of our development. Low-price, easy-to-handle, and nontoxic materials were used. Therefore, our work represents an important contribution to the development of TiO2 anatase nanoparticle coatings that provide a high photocatalytic effect and can thus be used for numerous applications.

  4. Impact of Overlapping Fe/TiO2 Prepared by Sol-Gel and Dip-Coating Process on CO2 Reduction

    Directory of Open Access Journals (Sweden)

    Akira Nishimura

    2016-01-01

    Full Text Available Fe-doped TiO2 (Fe/TiO2 film photocatalyst was prepared by sol-gel and dip-coating process to extend its photoresponsivity to the visible spectrum. To promote the CO2 reduction performance with the photocatalyst, some types of base materials used for coating Fe/TiO2, which were netlike glass fiber and Cu disc, were investigated. The characterization of prepared Fe/TiO2 film coated on netlike glass fiber and Cu disc was analyzed by SEM and EPMA. In addition, the CO2 reduction performance of Fe/TiO2 film coated on netlike glass disc, Cu disc, and their overlap was tested under a Xe lamp with or without ultraviolet (UV light, respectively. The results show that the concentration of produced CO increases by Fe doping irrespective of base material used under the illumination condition with UV light as well as that without UV light. Since the electron transfer between two overlapped photocatalysts is promoted, the peak concentration of CO for the Fe/TiO2 double overlapping is approximately 1.5 times as large as the Fe/TiO2 single overlapping under the illumination condition with UV light, while the promotion ratio is approximately 1.1 times under that without UV light.

  5. Preparation and characterization of reactively sintered Ni{sub 3}Al-hBN-Ag composite coating on Ni-based superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Shitang [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Zhou Jiansong [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Guo Baogang [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Zhou Huidi [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Pu Yuping [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Central Iron and Steel Research Institute, Beijing 100081 (China); Chen Jianmin [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)], E-mail: chenjm@lzb.ac.cn

    2009-04-03

    Ni{sub 3}Al-hBN-Ag intermetallic matrix composite coating was prepared on Ni-based superalloy by reactive sintering. The crystalline phase and microstructure of the coating were examined by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The results showed that the hBN particles pretreated by electroless nickel plating and hot-dip aluminizing and Ag particles with a size of several micrometers were homogeneously dispersed in the Ni{sub 3}Al matrix, and the composite coating had strong interfacial bonding with a fine and dense microstructure. During the reactive sintering, an exothermic reaction between Ni and Al associated with a transient liquid phase occurred, leading to in situ synthesis of the densified Ni{sub 3}Al matrix in the coating with a high tensile strength of more than 70 MPa. The high-temperature tribological properties evaluated on a ball-on-disc test rig showed that the coating possessed self-lubricating properties from room temperature to 800 deg. C due to a synergetic lubricating action of Ag and hBN.

  6. One-step preparation of superhydrophobic acrylonitrile-butadiene-styrene copolymer coating for ultrafast separation of water-in-oil emulsions.

    Science.gov (United States)

    Deng, Wanshun; Long, Mengying; Zhou, Qiannan; Wen, Ni; Deng, Wenli

    2017-09-23

    Superhydrophobic membranes with opposite wettability toward water and oil are able to separate water-in-oil emulsions. By constructing porous and hierarchal-structured superhydrophobic coating on filter paper, we hope a quick separation process could be achieved due to the acceleration of both demulsification and penetration process. Here, superhydrophobic coatings were prepared by simply spraying environmental and cost-effective acrylonitrile-butadiene-styrene copolymer (ABS) colloid in dichloromethane onto filter paper. The morphologies and wettability of the obtained coatings were carefully studied. Moreover, the separation performances in dealing with various surfactant-stabilized water-in-oil emulsions (SSWOE) were also investigated to verify our hypothesis. The morphologies of the ABS coatings varied with its weight concentration in dichloromethane and they changed from porous and plain surface into porous and hierarchal-structured surface. Besides, the hydrophobicity of the above coatings varied form hydrophobic to superhydrophobic. Moreover, the resulted superhydrophobic membranes show great separation capability in separating various span 80-stabilized water-in-oil emulsions with oil filtrate purities larger than 99.90% and huge penetration fluxes whose maximum is over 13,000L/(m(2)h). Thus, we envision that such membrane can be a practical candidate in dealing with water-in-oil emulsions to obtain pure oils. Copyright © 2017. Published by Elsevier Inc.

  7. Preparation

    Directory of Open Access Journals (Sweden)

    M.M. Dardir

    2014-03-01

    Full Text Available Some hexanamide-mono and di-linoleniate esters were prepared by the reaction of linolenic acid and hexanamide (derived from the reaction of hexanoic acid and diethanolamine. The chemical structure for the newly prepared hexanamide-mono and di-linoleniate esters were elucidated using elemental analysis, (FTIR, H 1NMR and chemical ionization mass spectra (CI/Ms spectroscopic techniques. The results of the spectroscopic analysis indicated that they were prepared through the right method and they have high purity. The new prepared esters have high biodegradability and lower toxicity (environmentally friendly so they were evaluated as a synthetic-based mud (ester-based mud for oil-well drilling fluids. The evaluation included study of the rheological properties, filtration and thermal properties of the ester based-muds formulated with the newly prepared esters compared to the reference commercial synthetic-based mud.

  8. Preparation and properties of β-SiAlON/ZrN nano-composites from ZrO2-coated Si3N4 powder

    Directory of Open Access Journals (Sweden)

    Aljoša Maglica

    2007-12-01

    Full Text Available In this study we report on the preparation and properties ofβ-SiAlON/ZrN electro-conductive nano-composites from ZrO2-coated Si3N4 powder. The silicon nitride powder was coated with nano-sized zirconia particles by the precipitation of ZrO2 from a zirconium acetate solution using urea as the precipitating agent. For the preparation of sintered β-SiAlON/ZrN composites two different approaches were used. In the first one the ZrO2-coated Si3N4 powder was mixed with the appropriate sintering additives (Al2O3, Y2O3 and AlN and reaction sintered, while in the second approach the coated powder was first calcined at 1600°C to prepare ZrNcoated Si3N4 powder that was subsequently mixed with the sintering additives and sintered. For comparison, composites with the same composition were also prepared by mixing Si3N4 and ZrO2 powders with sintering additives and sintered. During the thermal treatment and/or sintering of the Si3N4/ZrO2/AlN powder mixtures zirconia reacts with silicon nitride and aluminium nitride to form zirconium nitride. However, during sintering the agglomeration and grain growth of small, nanometric ZrN particles occurs. Despite the fact that the samples were sintered at atmospheric pressure they are dense, have relatively good flexural strengths and are electrically conductive.

  9. Preparation of polydopamine-coated graphene oxide/Fe3O4 imprinted nanoparticles for selective removal of fluoroquinolone antibiotics in water

    OpenAIRE

    Tan, Feng; Liu, Min; Ren, Suyu

    2017-01-01

    Antibiotics in water have recently caused increasing concerns for public health and ecological environments. In this work, we demonstrated polydopamine-coated graphene oxide/Fe3O4 (PDA@GO/Fe3O4) imprinted nanoparticles coupled with magnetic separation for fast and selective removal of fluoroquinolone antibiotics in water. The nanoparticles were prepared by the self-polymerization of dopamine using sarafloxacin as a template. The imprinted PDA film of 10~20?nm uniformly covered the surface of ...

  10. Preparation of transparent fluorocarbon/TiO{sub 2}-SiO{sub 2} composite coating with improved self-cleaning performance and anti-aging property

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jianping, E-mail: zf161162@163.com; Tan, Zhongyuan; Liu, Zhilei; Jing, Mengmeng; Liu, Wenjie; Fu, Wanli

    2017-02-28

    Graphical abstract: Semicrystalline colloidal particles of TiO{sub 2}-SiO{sub 2} composite oxide were prepared via a sol-gel approach and annealed by a microwave heating treatment. The fabricated fluorocarbon/TiO{sub 2}-SiO{sub 2} composite coatings are transparent, exhibit a highly stable and excellent hydrophilicity, an improved photocatalytic activity and outstanding self-cleaning performance. What’s more, the composite coatings display an excellent anti-aging performance toward UV irradiation. These findings indicate that the fluorocarbon/TiO{sub 2}-SiO{sub 2} composite coatings could be potentially used for outdoor applications. - Highlights: • Semicrystalline colloidal particles of TiO{sub 2}-SiO{sub 2} composite oxide presenting a particle size of 6–10 nm were prepared via a sol-gel approach and annealed by microwave heating method. • The fabricated transparent fluorocarbon/TiO{sub 2}-SiO{sub 2} composite coatings exhibited a superior hydrophilicity, an improved photocatalytic activity and excellent self-cleaning performance. • The fluorocarbon/TiO{sub 2}-SiO{sub 2} composite coatings exhibited an excellent anti-aging performance toward UV irradiation, rendering it quite suitable for outdoor applications. - Abstract: This work reports a facile method to fabricate transparent self-cleaning fluorocarbon coatings filled by semicrystalline colloidal particles of TiO{sub 2}-SiO{sub 2} composite oxide presenting a particle size ranging from 6 to 10 nm. Anatase-TiO{sub 2} crystallites were successfully obtained after microwave heating treatment of the TiO{sub 2}-SiO{sub 2} colloidal particles as confirmed by XRD, TEM and FTIR measurements. The fluorocarbon/TiO{sub 2}-SiO{sub 2} composite coatings exhibited a superior hydrophilicity and an improved photocatalytic activity in contrast to the TiO{sub 2}-filled coatings. In particular, a water contact angle (WCA) value of 4.5° and a decolorization ratio relative to methyl orange as high as 96.0% were

  11. Influence of precursor solution parameters on chemical properties of calcium phosphate coatings prepared using Electrostatic Spray Deposition (ESD).

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.; Wolke, J.G.C.; Schoonman, J.; Jansen, J.A.

    2004-01-01

    A novel coating technique, referred to as Electrostatic Spray Deposition (ESD), was used to deposit calcium phosphate (CaP) coatings with a variety of chemical properties. The relationship between the composition of the precursor solutions and the crystal and molecular structure of the deposited

  12. Membrane electrode assembly with enhanced platinum utilization for high temperature proton exchange membrane fuel cell prepared by catalyst coating membrane method

    Science.gov (United States)

    Liang, Huagen; Su, Huaneng; Pollet, Bruno G.; Linkov, Vladimir; Pasupathi, Sivakumar

    2014-11-01

    In this work, membrane electrode assemblies (MEAs) prepared by catalyst coating membrane (CCM) method are investigated for reduced platinum (Pt) loading and improved Pt utilization of high temperature proton exchange membrane fuel cell (PEMFC) based on phosphoric acid (PA)-doped poly(2,5-benzimidazole) (AB-PBI) membrane. The results show that CCM method exhibits significantly higher cell performance and Pt-specific power density than that of MEAs prepared with conventional gas diffusion electrode (GDE) under a low Pt loading level. In-suit cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) show that the MEAs prepared by the CCM method have a higher electrochemical surface area (ECSA), low cell ohmic resistance and low charge transfer resistance as compared to those prepared with GDEs at the same Pt loading.

  13. Preparation and characterization of iron oxide (Fe{sub 3}O{sub 4}) nanoparticles coated with polyvinylpyrrolidone/polyethylenimine through a facile one-pot deposition route

    Energy Technology Data Exchange (ETDEWEB)

    Karimzadeh, Isa [Shefa Neuroscience Research Center, Khatam ol Anbia Specialty and Subspecialty Hospital, Tehran (Iran, Islamic Republic of); Department of Physics, Faculty of Science, Central Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Aghazadeh, Mustafa, E-mail: maghazadeh@aeoi.org.ir [NFCRS, Nuclear Science and Technology Research Institute (NSTRI), P.O. Box 14395-834, Tehran (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Doroudi, Taher; Kolivand, Peir Hossein [Shefa Neuroscience Research Center, Khatam ol Anbia Specialty and Subspecialty Hospital, Tehran (Iran, Islamic Republic of)

    2017-07-01

    Highlights: • MNPs were prepared by cathodic electrodeposition. • In situ double polymer coating was achieved during electrodeposition. • The prepared MNPs have proper size and properties for biomedical applications. - Abstract: In this article, we report the electrochemical synthesis and simultaneous in situ coating of magnetic iron oxide nanoparticles (MNPs) with polyvinylpyrrolidone (PVP) and polyethylenimine (PEI). The cathodic deposition was carried out through electro-generation of OH{sup −} on the surface of cathode. An aqueous solution of Fe(NO{sub 3}){sub 3}·9H{sub 2}O (3.4 g/L) and FeCl{sub 2}·4H{sub 2}O (1.6 g/L) was used as the deposition bath. The electrochemical precipitation experiments were performed in the direct current mode under a 10 mA cm{sup −2} current density for 30 min. Polymer coating was performed in an identical deposition bath containing of 0.5 g PVP and 0.5 g PEI. The deposited uncoated and PVP-PEI coated MNPs were characterized through powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), and field-emission scanning and transmission electron microscopies (FE-SEM and TEM). Structural XRD and IR analyses revealed both samples to be composed of pure crystalline magnetite (Fe{sub 3}O{sub 4}). Morphological observations through FE-SEM and TEM proved the product to be spherical nanoparticles in the range of 10–15 nm. The presence of two coating polymers (i.e. PVP and PEI) on the surface of the electro-synthesized MNPs was proved by FTIR and DLS results. The percentage of the polymer coating (31.8%) on the MNPs surface was also determined based on DSC-TGA data. The high magnetization value, coercivity and remanence values measured by VSM indicated the superparamagnetic nature of both prepared MNPs. The obtained results confirmed that the prepared Fe{sub 3}O{sub 4} nanoparticles had suitable physico

  14. Preparation of a TiMEMO nanocomposite by the sol-gel method and its application in coloured thickness insensitive spectrally selective (TISS) coatings

    Energy Technology Data Exchange (ETDEWEB)

    Japelj, Bostjan; Vuk, Angela Surca; Orel, Boris; Perse, Lidija Slemenik; Jerman, Ivan [National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Kovac, Janez [Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2008-09-15

    An organic-inorganic nanocomposite was prepared via sol-gel processing from 3-(trimethoxysilyl)propyl methacrylate (MAPTMS) and titanium(IV) isopropoxide (TIP) precursors (TiMEMO) in the form of a viscous resin, and used as a binder for the preparation of coloured thickness insensitive spectrally selective (TISS) paints and corresponding solar absorber coatings. The spectral selectivity of TiMEMO-based TISS paints was optimized by varying the concentrations of binder and different pigments: black, coloured (red, green and blue) and aluminium flakes, the latter imparting low thermal emittance, which was correlated to the presence of titanium in the TiMEMO sol-gel host. The formation and the ensuing structure of the sol-gel TiMEMO hybrid was studied in detail and the nanocomposite structure of the TiMEMO binder formed was assessed from infrared and {sup 29}Si NMR measurements, which confirmed the formation of Ti-O-Si linkages established after the hydrolysed precursors condensed into a compliant resinous material. XRD measurements provided additional information about the existence of small coherent domains of silsesquioxane units in the sol-gel host. The abrasion resistance of the non-pigmented TiMEMO binder deposited in thin film form on a PMMA substrate was assessed by the Taber test, and its hardness compared with other resin binders which have been used for making TISS paint coatings. The surface properties of the non-pigmented TiMEMO binder and the ensuing TISS paint coatings were determined from contact angle measurements. The results showed that the water contact angles of non-pigmented TiMEMO binder increased from 70 to 125-135 for the corresponding pigmented TISS paint coatings, inferring the influence of surface roughness on surface energy in the presence of pigments. SEM measurements revealed a striking similarity in the surface morphology of the TISS paint coatings with some other surfaces exhibiting the Lotus effect. (author)

  15. Preparation of antibacterial coating based on in situ synthesis of ZnO/SiO{sub 2} hybrid nanocomposite on cotton fabric

    Energy Technology Data Exchange (ETDEWEB)

    Barani, Hossein, E-mail: barani@birjand.ac.ir

    2014-11-30

    Graphical abstract: - Highlights: • In situ approach was used to synthesize ZnO/SiO{sub 2} nanocomposites. • Spherical structure and stabilized ZnO/SiO{sub 2} hybrid nanocomposites were synthesized. • The synthesized ZnO particles have a hexagonal wurtzite crystal structure. • The ZnO nanoparticles enhance the moisture content of cotton fabric. • ZnO/SiO{sub 2} loaded cotton fabrics presented a good antibacterial property. - Abstract: In this study, the antibacterial cotton fabric was prepared using zinc oxide/silicon dioxide (ZnO/SiO{sub 2}) nanocomposite. The ZnO nanoparticles were synthesized with an in situ approach using two different methods on the cotton fabric. One of the methods was to synthesize ZnO nanoparticles into the prepared sol solution, and then coating on the cotton fabric. The other method was to synthesize ZnO nanoparticles on the silicon dioxide-coated cotton fabric. The morphological, structural, thermal, and antibacterial properties of ZnO/SiO{sub 2} nanocomposite-coated cotton fabric was studied using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffractometer, thermo gravimetric analysis, and Attenuated Total Reflection-Fourier Transform Infrared spectrometer. Synthesis of ZnO nanoparticles on the silicon dioxide coated cotton fabric sample resulted in agglomerated nanoparticles on the surface of cotton fiber, while the spherical nanoparticles structure was formed by synthesizing them into the sol solution of silicon dioxide. The EDS results indicated presence of ZnO/SiO{sub 2} nanocomposite on the surface of coated cotton fabric, and presented an inhibition zone against Staphylococcus aureus and Escherichia coli.

  16. Superhydrophobic and anti-reflective ZnO nanorod-coated FTO transparent conductive thin films prepared by a three-step method

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bao-jia, E-mail: li_bjia@126.com [School of Materials Science and Engineering, Jiangsu University, Zhenjiang, 212013 (China); Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang, 212013 (China); Huang, Li-jing; Ren, Nai-fei [Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang, 212013 (China); School of Mechanical Engineering, Jiangsu University, Zhenjiang, 212013 (China); Kong, Xia; Cai, Yun-long; Zhang, Jie-lu [Jiangsu Tailong Reduction Box Co. Ltd., Taixing, 225400 (China)

    2016-07-25

    A ZnO nanorod-coated FTO film was prepared by sputtering an AZO layer on FTO glass, thermal annealing of the AZO/FTO film, and hydrothermal growth of ZnO nanorods at 70 °C on the annealed AZO/FTO film using zinc foils as zinc source. Two other ZnO nanorod-coated FTO films were also prepared by hydrothermal growths of ZnO nanorods on the FTO glass and the unannealed AZO/FTO film respectively for comparison purpose. The results were observed in detail using X-ray diffraction, scanning electron microscopy, water contact/sliding angle measurement, spectrophotometry and four-point probe measurement. The ZnO nanorods on the annealed AZO/FTO film were found to exhibit denser distribution and better orientation than those on the FTO glass and the unannealed AZO/FTO film. As a result, the ZnO nanorod-coated annealed AZO/FTO film demonstrated superhydrophobicity, high transparency and low reflectance in the visible range. Also this film had the lowest sheet resistance of 4.0 Ω/sq, implying its good electrical conductivity. This investigation provides a valuable reference for developing multifunctional transparent conductive films. - Highlights: • ZnO nanorod-coated annealed AZO/FTO film was obtained by a three-step method. • FTO and unannealed AZO/FTO films were also used as substrates for comparison. • ZnO nanorods on the annealed AZO/FTO film were denser and more vertically-oriented. • The ZnO nanorod-coated annealed AZO/FTO film (Z/TA-FTO) had superhydrophobicity. • The Z/TA-FTO exhibited high transparency, low reflectance and good conductivity.

  17. Preparation and characterization of iron oxide (Fe3O4) nanoparticles coated with polyvinylpyrrolidone/polyethylenimine through a facile one-pot deposition route

    Science.gov (United States)

    Karimzadeh, Isa; Aghazadeh, Mustafa; Ganjali, Mohammad Reza; Doroudi, Taher; Kolivand, Peir Hossein

    2017-07-01

    In this article, we report the electrochemical synthesis and simultaneous in situ coating of magnetic iron oxide nanoparticles (MNPs) with polyvinylpyrrolidone (PVP) and polyethylenimine (PEI). The cathodic deposition was carried out through electro-generation of OH- on the surface of cathode. An aqueous solution of Fe(NO3)3·9H2O (3.4 g/L) and FeCl2·4H2O (1.6 g/L) was used as the deposition bath. The electrochemical precipitation experiments were performed in the direct current mode under a 10 mA cm-2 current density for 30 min. Polymer coating was performed in an identical deposition bath containing of 0.5 g PVP and 0.5 g PEI. The deposited uncoated and PVP-PEI coated MNPs were characterized through powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), and field-emission scanning and transmission electron microscopies (FE-SEM and TEM). Structural XRD and IR analyses revealed both samples to be composed of pure crystalline magnetite (Fe3O4). Morphological observations through FE-SEM and TEM proved the product to be spherical nanoparticles in the range of 10-15 nm. The presence of two coating polymers (i.e. PVP and PEI) on the surface of the electro-synthesized MNPs was proved by FTIR and DLS results. The percentage of the polymer coating (31.8%) on the MNPs surface was also determined based on DSC-TGA data. The high magnetization value, coercivity and remanence values measured by VSM indicated the superparamagnetic nature of both prepared MNPs. The obtained results confirmed that the prepared Fe3O4 nanoparticles had suitable physico-chemical and magnetic properties for biomedical applications.

  18. Preparation of Nafion-sulfonated clay nanocomposite membrane for direct menthol fuel cells via a film coating process

    Science.gov (United States)

    Kim, Tae Kyoung; Kang, Myeongsoon; Choi, Yeong Suk; Kim, Hae Kyung; Lee, Wonmok; Chang, Hyuk; Seung, Doyoung

    Nafion sulfonated clay nanocomposite membranes were successfully produced via a film coating process using a pilot coating machine. For producing the composite membranes, we optimized the solvent ratio of N-methyl-2-pyrrolidinone (NMP) to N, N‧-dimethylacetamide (DMAc), the amount of sulfonated montmorillonite (S-MMT) in composite membranes and the overall concentration of composite dispersions. Based on the optimized viscosity and composition, the composite dispersions were coated on a poly(ethylene terephthalate) (PET) substrate film. The distance between a metering roll and a PET film and the ratio of metering roll speed versus coating roll speed of the pilot coating machine were varied to control membrane thickness. The film coated composite membrane exhibited enhanced properties in the swelling behavior against MeOH solution, ion conductivity and MeOH permeability, compared to the cast Nafion composite membrane due to the higher dispersion state of S-MMT in Nafion matrix and the uniform distribution of small-size ion clusters. These properties influenced a cell performance test of a direct methanol fuel cell (DMFC), showing the film coated composite membrane had a higher power density than that of Nafion 115. The power density was also related with the higher selectivity of the composite membrane than Nafion 115.

  19. Preparation of Nafion-sulfonated clay nanocomposite membrane for direct methanol fuel cells via a film coating process

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Kyoung; Kang, Myeongsoon [Research Institute of Chemical and Electronic Materials, Cheil Industries Inc., Uiwang-si 437-711 (Korea); Choi, Yeong Suk; Kim, Hae Kyung; Lee, Wonmok; Chang, Hyuk; Seung, Doyoung [Energy and Materials Research Lab, Samsung Advanced Institute of Technology (SAIT) P.O. Box 111, Suwon 449-600 (Korea)

    2007-02-25

    Nafion sulfonated clay nanocomposite membranes were successfully produced via a film coating process using a pilot coating machine. For producing the composite membranes, we optimized the solvent ratio of N-methyl-2-pyrrolidinone (NMP) to N,N'-dimethylacetamide (DMAc), the amount of sulfonated montmorillonite (S-MMT) in composite membranes and the overall concentration of composite dispersions. Based on the optimized viscosity and composition, the composite dispersions were coated on a poly(ethylene terephthalate) (PET) substrate film. The distance between a metering roll and a PET film and the ratio of metering roll speed versus coating roll speed of the pilot coating machine were varied to control membrane thickness. The film coated composite membrane exhibited enhanced properties in the swelling behavior against MeOH solution, ion conductivity and MeOH permeability, compared to the cast Nafion composite membrane due to the higher dispersion state of S-MMT in Nafion matrix and the uniform distribution of small-size ion clusters. These properties influenced a cell performance test of a direct methanol fuel cell (DMFC), showing the film coated composite membrane had a higher power density than that of Nafion 115. The power density was also related with the higher selectivity of the composite membrane than Nafion 115. (author)

  20. Bax-inhibitor-1 knockdown phenotypes are suppressed by Buffy and exacerbate degeneration in a Drosophila model of Parkinson disease.

    Science.gov (United States)

    M'Angale, P Githure; Staveley, Brian E

    2017-01-01

    Bax inhibitor-1 (BI-1) is an evolutionarily conserved cytoprotective transmembrane protein that acts as a suppressor of Bax-induced apoptosis by regulation of endoplasmic reticulum stress-induced cell death. We knocked down BI-1 in the sensitive dopa decarboxylase (Ddc) expressing neurons of Drosophila melanogaster to investigate its neuroprotective functions. We additionally sought to rescue the BI-1-induced phenotypes by co-expression with the pro-survival Buffy and determined the effect of BI-1 knockdown on the neurodegenerative α-synuclein-induced Parkinson disease (PD) model. We used organismal assays to assess longevity of the flies to determine the effect of the altered expression of BI-1 in the Ddc-Gal4-expressing neurons by employing two RNAi transgenic fly lines. We measured the locomotor ability of these RNAi lines by computing the climbing indices of the climbing ability and compared them to a control line that expresses the lacZ transgene. Finally, we performed biometric analysis of the developing eye, where we counted the number of ommatidia and calculated the area of ommatidial disruption. The knockdown of BI-1 in these neurons was achieved under the direction of the Ddc-Gal4 transgene and resulted in shortened lifespan and precocious loss of locomotor ability. The co-expression of Buffy, the Drosophila anti-apoptotic Bcl-2 homologue, with BI-1-RNAi resulted in suppression of the reduced lifespan and impaired climbing ability. Expression of human α-synuclein in Drosophila dopaminergic neurons results in neuronal degeneration, accompanied by the age-dependent loss in climbing ability. We exploited this neurotoxic system to investigate possible BI-1 neuroprotective function. The co-expression of α-synuclein with BI-1-RNAi results in a slight decrease in lifespan coupled with an impairment in climbing ability. In supportive experiments, we employed the neuron-rich Drosophila compound eye to investigate subtle phenotypes that result from altered gene

  1. Bax-inhibitor-1 knockdown phenotypes are suppressed by Buffy and exacerbate degeneration in a Drosophila model of Parkinson disease

    Directory of Open Access Journals (Sweden)

    P. Githure M’Angale

    2017-02-01

    Full Text Available Background Bax inhibitor-1 (BI-1 is an evolutionarily conserved cytoprotective transmembrane protein that acts as a suppressor of Bax-induced apoptosis by regulation of endoplasmic reticulum stress-induced cell death. We knocked down BI-1 in the sensitive dopa decarboxylase (Ddc expressing neurons of Drosophila melanogaster to investigate its neuroprotective functions. We additionally sought to rescue the BI-1-induced phenotypes by co-expression with the pro-survival Buffy and determined the effect of BI-1 knockdown on the neurodegenerative α-synuclein-induced Parkinson disease (PD model. Methods We used organismal assays to assess longevity of the flies to determine the effect of the altered expression of BI-1 in the Ddc-Gal4-expressing neurons by employing two RNAi transgenic fly lines. We measured the locomotor ability of these RNAi lines by computing the climbing indices of the climbing ability and compared them to a control line that expresses the lacZ transgene. Finally, we performed biometric analysis of the developing eye, where we counted the number of ommatidia and calculated the area of ommatidial disruption. Results The knockdown of BI-1 in these neurons was achieved under the direction of the Ddc-Gal4 transgene and resulted in shortened lifespan and precocious loss of locomotor ability. The co-expression of Buffy, the Drosophila anti-apoptotic Bcl-2 homologue, with BI-1-RNAi resulted in suppression of the reduced lifespan and impaired climbing ability. Expression of human α-synuclein in Drosophila dopaminergic neurons results in neuronal degeneration, accompanied by the age-dependent loss in climbing ability. We exploited this neurotoxic system to investigate possible BI-1 neuroprotective function. The co-expression of α-synuclein with BI-1-RNAi results in a slight decrease in lifespan coupled with an impairment in climbing ability. In supportive experiments, we employed the neuron-rich Drosophila compound eye to investigate

  2. Surface characteristics of hydroxyapatite-coated layer prepared on nanotubular Ti–35Ta–xHf alloys by EB-PVD

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yong-Hoon [Department of Dental Materials and Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Biomechanics and Tissue Engineering Laboratory, Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States); Moon, Byung-Hak [Department of Dental Materials and Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials and Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Brantley, William A. [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, Columbus, OH (United States)

    2013-12-31

    In this study, we investigated the surface characteristics of hydroxyapatite (HA)-coated layers prepared by electron-beam physical vapor deposition (EB-PVD) on nanotubular Ti–35Ta–xHf alloys (x = 3, 7, and 15 wt.%). Ti–35Ta–xHf alloys were first prepared by arc melting. Formation of a nanotube structure on these alloys was achieved by an electrochemical method in 1 M H{sub 3}PO{sub 4} + 0.8 wt.% NaF electrolytes. The HA coatings were then deposited on the nanotubular surface by an EB-PVD method. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction (XRD). The electrochemical behavior was examined using a potentiodynamic polarization test in 0.9% NaCl solution. The Ti–35Ta–xHf alloys had an equiaxed grain structure with α″ + β phases, and the α″ phase disappeared with increases in Hf content. The Ti–35Ta–15Hf alloy showed higher β-phase peak intensity in the XRD patterns than that for the lower Hf-content alloys. A highly ordered nanotubular oxide layer was formed on the Ti–35Ta–15Hf alloy, and the tube length depended on Hf content. The HA coating surface formed at traces of the nanotubular titanium oxide layer and completely covered the tips of the nanotubes with a cluster shape. From the potentiodynamic polarization tests, the incorporation of Hf element and formation of the nanotubular structure were the main factors for achieving lower current density. In particular, the surface of the HA coating on the nanotubular structure exhibited higher corrosion resistance than that of the nanotubular titanium oxide structure without an HA coating. - Highlights: • Hydroxyapatite (HA) was coated on nanotubular Ti–35Ta–xHf alloys, using EB-PVD. • Increasing the Hf content reduced the relative proportion of α″ martensite to β-Ti in the microstructures. • The detailed nanotubular structure formed by anodization depended on alloy composition

  3. Preparation and evaluation of a novel molecularly imprinted polymer coating for selective extraction of indomethacin from biological samples by electrochemically controlled in-tube solid phase microextraction

    Energy Technology Data Exchange (ETDEWEB)

    Asiabi, Hamid [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Yamini, Yadollah, E-mail: yyamini@modares.ac.ir [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Seidi, Shahram; Ghahramanifard, Fazel [Department of Analytical Chemistry, Faculty of Chemistry, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of)

    2016-03-24

    In the present work, an automated on-line electrochemically controlled in-tube solid-phase microextraction (EC-in-tube SPME) coupled with HPLC-UV was developed for the selective extraction and preconcentration of indomethacin as a model analyte in biological samples. Applying an electrical potential can improve the extraction efficiency and provide more convenient manipulation of different properties of the extraction system including selectivity, clean-up, rate, and efficiency. For more enhancement of the selectivity and applicability of this method, a novel molecularly imprinted polymer coated tube was prepared and applied for extraction of indomethacin. For this purpose, nanostructured copolymer coating consisting of polypyrrole doped with ethylene glycol dimethacrylate was prepared on the inner surface of a stainless-steel tube by electrochemical synthesis. The characteristics and application of the tubes were investigated. Electron microscopy provided a cross linked porous surface and the average thickness of the MIP coating was 45 μm. Compared with the non-imprinted polymer coated tubes, the special selectivity for indomethacin was discovered with the molecularly imprinted coated tube. Moreover, stable and reproducible responses were obtained without being considerably influenced by interferences commonly existing in biological samples. Under the optimal conditions, the limits of detection were in the range of 0.07–2.0 μg L{sup −1} in different matrices. This method showed good linearity for indomethacin in the range of 0.1–200 μg L{sup −1}, with coefficients of determination better than 0.996. The inter- and intra-assay precisions (RSD%, n = 3) were respectively in the range of 3.5–8.4% and 2.3–7.6% at three concentration levels of 7, 70 and 150 μg L{sup −1}. The results showed that the proposed method can be successfully applied for selective analysis of indomethacin in biological samples. - Graphical abstract: An automated on

  4. Fabrication and design of bioactive agent coated, highly-aligned electrospun matrices for nerve tissue engineering: Preparation, characterization and application

    Science.gov (United States)

    Lee, Sang Jin; Heo, Min; Lee, Donghyun; Heo, Dong Nyoung; Lim, Ho-Nam; Kwon, Il Keun

    2017-12-01

    In this study, we designed highly-aligned thermoplastic polycarbonate urethane (PCU) fibrous scaffolds coated with bioactive compounds, such as Poly-L-Lysine (PLL) and Poly-L-Ornithine (PLO), to enhance cellular adhesion and directivity. These products were characterized by scanning electron microscope (SEM) analysis which demonstrated that highly aligned fiber strands were formed without beads when coated onto a mandrel rotating at 1800 rpm. During in vitro cell test, PLO-coated, aligned PCU scaffolds were found to have significantly higher proliferation rates than PLL coated and bare PCU scaffolds. Interestingly, dental pulp stem cells (DPSCs) were observed to stretch along the longitudinal axis parallel to the cell direction on highly aligned scaffolds. These results clearly confirm that our strategy may suggest a useful paradigm by inducing neural tissue repair as a means to remodeling and healing of tissue for restorative procedures in neural tissue engineering.

  5. A novel in situ strategy for the preparation of a β-cyclodextrin/polydopamine-coated capillary column for capillary electrochromatography enantioseparations.

    Science.gov (United States)

    Guo, Heying; Niu, Xiaoying; Pan, Congjie; Yi, Tao; Chen, Hongli; Chen, Xingguo

    2017-06-01

    Inspired by the chiral recognition ability of β-cyclodextrin and the natural adhesive properties of polydopamine under alkaline conditions, in this study, a rapid and in situ modification strategy was developed to fabricate β-cyclodextrin/polydopamine composite material coated-capillary columns for open tubular capillary electrochromatography. The results of scanning electron microscopy, FTIR spectroscopy, streaming potential, and electro-osmotic flow studies indicated that β-cyclodextrin/polydopamine was successfully fixed on the inner wall of the capillary column. This coating can be achieved within 1 h affording a greatly reduced capillary preparation time. The performance of the β-cyclodextrin/polydopamine-coated capillary was validated by the analysis of seven pairs of chiral analytes, namely epinephrine, norepinephrine, isoprenaline, terbutaline, verapamil, tryptophane, carvedilol. Good enantioseparation efficiencies were achieved for all. For three consecutive runs, the relative standard deviations for the migration times of the analytes for intraday, interday, and column-to-column repeatability were in the range of 0.41-1.74, 1.03-4.18, and 1.66-8.24%, respectively. Moreover, the separation efficiency of the β-cyclodextrin/polydopamine-coated capillary column did not decrease obviously over 90 runs. The strategy should also be feasible to introduce and immobilize other chiral selectors on the inner walls surface of capillary columns. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Thin coatings based on ZnO@C18-usnic acid nanoparticles prepared by MAPLE inhibit the development of Salmonella enterica early biofilm growth

    Science.gov (United States)

    Stan, Miruna Silvia; Constanda, Sabrina; Grumezescu, Valentina; Andronescu, Ecaterina; Ene, Ana Maria; Holban, Alina Maria; Vasile, Bogdan Stefan; Mogoantă, Laurenţiu; Bălşeanu, Tudor-Adrian; Mogoşanu, George Dan; Socol, Gabriel; Grumezescu, Alexandru Mihai; Dinischiotu, Anca; Lazar, Veronica; Chifiriuc, Mariana Carmen

    2016-06-01

    The aim of this study was to develop a nanostructured bioactive surface based on zinc oxide, sodium stearate (C18) and usnic acid (UA) exhibiting harmless effects with respect to the human cells, but with a significant antimicrobial effect, limiting the attachment and biofilm formation of food pathogens. ZnO nanoparticles were synthesized by sol-gel method and functionalized with C18 and UA. The coatings were fabricated by matrix assisted pulsed laser evaporation technique (MAPLE) and further characterized by TEM, SEM, SAED, XRD and IRM. The biological characterization of the prepared coatings consisted in cytotoxicity and antimicrobial assays. The cytotoxicity of ZnO@C18 and ZnO@C18-UA films was evaluated with respect to the human skin fibroblasts (CCD 1070SK cell line) by phase contrast microscopy, MTT assay and nitric oxide (NO) release. The covered surfaces exhibited a decreased cell attachment, effect which was more pronounced in the presence of UA as shown by purple formazan staining of adhered cells. The unattached fibroblasts remained viable after 24 h in the culture media as it was revealed by their morphology analysis and NO level which were similar to uncovered slides. The quantitative microbiological assays results have demonstrated that the bioactive coatings have significantly inhibited the adherence and biofilm formation of Salmonella enterica. The obtained results recommend these materials as efficient approaches in developing anti-adherent coatings for various industrial, medical and food processing applications.

  7. Isosorbide-5-mononitrate (5-ISMN) sustained-release pellets prepared by double layer coating for reducing 5-ISMN migration and sublimation.

    Science.gov (United States)

    Li, Guofei; Han, Dandan; Guan, Tingting; Zhao, Xingna; He, Haibing; Tang, Xing

    2010-11-15

    The major aim of this study was to prepare isosorbide-5-mononitrate (5-ISMN) sustained-release pellets and evaluate their stability. The pellets were prepared by extrusion/spheronization, and then the core pellets were coated with ethylcellulose (EC 10cp) and Eudragit(®)NE30D. Here, EC was used as the subcoating agent while Eudragit(®)NE30D acted as the outer-coating agent. 5-ISMN sustained-release pellets as a novel drug delivery system contained the immediate-release portion in the outer-coating layer. Unexpectedly, 5-ISMN was found to migrate from the interior of the pellets to the surface forming needle crystals and exhibited the phenomenon of sublimation, which resulted in a tremendous increase in the release rate. Our research showed that the migration and sublimation of the active ingredient was related to the temperature and humidity. Polyvinylpyrrolidone (PVP K30) can affect the precipitation of 5-ISMN by forming a charge transfer complex between the drug and PVP, while hydroxypropyl methyl cellulose (HPMC E5) had no effect, and confirmed the correctness of this view through photographs and IR spectra. In the investigation of the stability, the results showed that there was no sublimation and migration while the pellets stored at 25°C/60%RH (ambient conditions) and 40°C/75% RH (stress conditions) during a 6-month period. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. High-temperature tribological characteristics of silver and gold coatings on ceramics prepared by ion-beam-assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Erdemir, A.; Erck, R.A.; Fenske, G.R.; Nichols, F.A.

    1992-04-01

    An ion-beam-assisted deposition (IBAD) system was used to deposit silver and gold coatings on polycrystalline {alpha}-alumina (Al{sub 2}O{sub 3}) substrates for tribological studies at temperatures to 400{degrees}C. The wear tests were performed with an oscillating ball-on-flat type of test apparatus as a partial simulation of ring/liner motion and contact geometry in actual engine systems. The test results showed that without a surface coating, both the wear rates and the friction coefficients of Al{sub 2}O{sub 3}/Al{sub 2}O{sub 3} test pairs were quite high, and increased substantially with temperature. In contract, the wear of flats coated with silver and gold was at unmeasurable levels, even after sliding tests of 110,000 passes. The wear of balls (uncoated) sliding against the Ag- and Au-coated flats was reduced by factors of 45 to more than 500 depending on coating type and ambient temperature. The friction coefficients of pairs with an IBAD-Ag or Au coating were in the range of 0.32--0.5.

  9. Drug loaded and ethylcellulose coated mesoporous silica for controlled drug release prepared using a pilot scale fluid bed system.

    Science.gov (United States)

    Hacene, Youcef Chakib; Singh, Abhishek; Van den Mooter, Guy

    2016-06-15

    The goal of this study was to test the feasibility to load non-ordered, non-spherical mesoporous silica with the model drug paracetamol, and subsequently coat the loaded particles using one single pilot scale fluid bed system equipped with a Wurster insert. Mesoporous silica particles (Davisil(®)) with a size ranging from 310 to 500μm and an average pore diameter of 15nm were loaded with paracetamol to 18.8% drug content. Subsequently, loaded cores were coated with ethylcellulose to obtain controlled drug release. Coating processing variables were varied following a full factorial design and their effect on drug release was assessed. Increasing coating solution feed rate and decreasing fluidizing air temperature were found to increase drug release rates. Increasing pore former level and decreasing coating level were found to increase drug release rates. The release medium's osmolality was varied using different sodium chloride concentrations, which was found to affect drug release rates. The results of this study clearly indicate the potential of non-ordered, non-spherical mesoporous silica as a reservoir carrier for the controlled release of drugs. Although non-spherical, we were able to reproducibly coat this carrier using a bottom spray fluid bed system. However, a major hurdle that needs to be tackled is the attrition the material suffers from during fluid bed processing. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Preparation And Characterization Of Organic Coatings Of Variable Thickness On Inert Cores And Their Chemical Reactions With Ozone

    Science.gov (United States)

    Katrib-Kouchnir, Y.; Martin, S. T.; Rudich, Y.; Zhang, H.; Davidovits, P.; Jayne, J. T.; Worsnop, D. R.

    2003-12-01

    Recent studies have emphasized the role of organic atmospheric particles in cloud formation, radiative forcing, and health effects. Quantification of these effects is limited because the compositions, morphologies, and chemical reactivities of organic particles are poorly understood. Laboratory studies are motivated to understand and quantify complex particles and their processes. A critical unknown is the heterogeneous chemistry that depends upon and leads to changes in the morphological and chemical complexity of the particles. Our work is focused on ozone heterogeneous chemistry as a general proxy for understanding the role of layer thickness and diffusivity in chemical transformations of surface and interior layers of complex particles. Our approach for preparing the particles is as follows. Polystyrene latex (PSL) particles are atomized into an aerosol flow. Oleic acid particles are formed by vapor condensation from a separate flow through a heated liquid reservoir. When the flows are mixed, the PSL and oleic acid particles are externally mixed. An oven having a linear hot-to-cold temperature gradient is employed to first evaporate the oleic acid particles in the hot region, which is followed by condensation in the cold region onto the surface of the PSL particles acting as heterogeneous nuclei. Internally mixed particles result. The apparatus capability is the controlled and reproducible generation of particles having 2 to 30 nm surface layers of oleic acid and 100 nm polystyrene latex (PSL) cores. The temperature of the reservoir, the gradient of the furnace, and the adjustable flow are the levers controlling the layer thickness of oleic acid. The particles are characterized in parallel by their electric mobility in a TSI Scanning Mobility Particle Sizer (SMPS) and their aerodynamic diameter in an Aerodyne Aerosol Mass Spectrometer (AMS). Diameter and oleic acid coating mass agree well by the two methods. The particle shape factor is approximately unity

  11. Characterizations of Cuprous Oxide Thin Films Prepared by Sol-Gel Spin Coating Technique with Different Additives for the Photoelectrochemical Solar Cell

    Directory of Open Access Journals (Sweden)

    D. S. C. Halin

    2014-01-01

    Full Text Available Cuprous oxide (Cu2O thin films were deposited onto indium tin oxide (ITO coated glass substrate by sol-gel spin coating technique using different additives, namely, polyethylene glycol and ethylene glycol. It was found that the organic additives added had a significant influence on the formation of Cu2O films and lead to different microstructures and optical properties. The films were characterized by X-ray diffraction (XRD, field emission scanning electron microscopy (FESEM, and ultraviolet-visible spectroscopy (UV-Vis. Based on the FESEM micrographs, the grain size of film prepared using polyethylene glycol additive has smaller grains of about 83 nm with irregular shapes. The highest optical absorbance film was obtained by the addition of polyethylene glycol. The Cu2O thin films were used as a working electrode in the application of photoelectrochemical solar cell (PESC.

  12. The role of surface preparation in corrosion protection of copper with nanometer-thick ALD alumina coatings

    Energy Technology Data Exchange (ETDEWEB)

    Mirhashemihaghighi, Shadi; Światowska, Jolanta [PSL Research University, CNRS – Chimie ParisTech, Institut de Recherche de Chimie Paris (IRCP), 11 rue Pierre et Marie Curie, 75005 Paris (France); Maurice, Vincent, E-mail: vincent.maurice@chimie-paristech.fr [PSL Research University, CNRS – Chimie ParisTech, Institut de Recherche de Chimie Paris (IRCP), 11 rue Pierre et Marie Curie, 75005 Paris (France); Seyeux, Antoine; Klein, Lorena H. [PSL Research University, CNRS – Chimie ParisTech, Institut de Recherche de Chimie Paris (IRCP), 11 rue Pierre et Marie Curie, 75005 Paris (France); Salmi, Emma; Ritala, Mikko [Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki (Finland); Marcus, Philippe [PSL Research University, CNRS – Chimie ParisTech, Institut de Recherche de Chimie Paris (IRCP), 11 rue Pierre et Marie Curie, 75005 Paris (France)

    2016-11-30

    Highlights: • 10–50 nm thick alumina coatings were grown on copper by atomic layer deposition. • Surface smoothening by substrate annealing was studied as pre-deposition treatment. • Corrosion protection is promoted by pre-treatment for 10 nm but not for thicker films. • Local adhesion failure is assigned to the stresses accumulated in the thicker films. • Surface smoothening decreases the interfacial strength bearing the film stresses. - Abstract: Surface smoothening by substrate annealing was studied as a pre-treatment for improving the corrosion protection provided to copper by 10, 20 and 50 nm thick alumina coatings deposited by atomic layer deposition. The interplay between substrate surface state and deposited film thickness for controlling the corrosion protection provided by ultrathin barrier films is demonstrated. Pre-annealing at 750 °C heals out the dispersed surface heterogeneities left by electropolishing and reduces the surface roughness to less than 2 nm independently of the deposited film thickness. For 10 nm coatings, substrate surface smoothening promotes the corrosion resistance. However, for 20 and 50 nm coatings, it is detrimental to the corrosion protection due to local detachment of the deposited films. The weaker adherence of the thicker coatings is assigned to the stresses accumulated in the films with increasing deposited thickness. Healing out the local heterogeneities on the substrate surface diminishes the interfacial strength that is bearing the stresses of the deposited films, thereby increasing adhesion failure for the thicker films. Pitting corrosion occurs at the local sites of adhesion failure. Intergranular corrosion occurs at the initially well coated substrate grain boundaries because of the growth of a more defective and permeable coating at grain boundaries.

  13. Microstructure and Wear Behavior of FeCoCrNiMo0.2 High Entropy Coatings Prepared by Air Plasma Spray and the High Velocity Oxy-Fuel Spray Processes

    Directory of Open Access Journals (Sweden)

    Tianchen Li

    2017-09-01

    Full Text Available In the present research, the spherical FeCoCrNiMo0.2 high entropy alloy (HEA powders with a single FCC solid solution structure were prepared by gas atomization. Subsequently, the FeCoCrNiMo0.2 coatings with a different content of oxide inclusions were prepared by air plasma spraying (APS and high-velocity oxy-fuel spraying (HVOF, respectively. The microstructure, phase composition, mechanical properties, and tribological behaviors of these HEA coatings were investigated. The results showed that both HEA coatings showed a typical lamellar structure with low porosity. Besides the primary FCC phase, a mixture of Fe2O3, Fe3O4, and AB2O4 (A = Fe, Co, Ni, and B = Fe, Cr was identified as the oxide inclusions. The oxide content of the APS coating and HVOF coating was calculated to be 47.0% and 12.7%, respectively. The wear resistance of the APS coating was approximately one order of magnitude higher than that of the HVOF coating. It was mainly attributed to the self-lubricated effect caused by the oxide films. The mass loss of the APS coating was mainly ascribed to the breakaway of the oxide film, while the main wear mechanism of the HVOF coating was the abrasive wear.

  14. Multilayer, degradable coating as a carrier for the sustained release of antibiotics: preparation and antimicrobial efficacy in vitro.

    Science.gov (United States)

    Guillaume, Olivier; Garric, Xavier; Lavigne, Jean-Philippe; Van Den Berghe, Helene; Coudane, Jean

    2012-09-28

    One of the most critical post-surgical complications is mesh-related infection. This paper describes how a commercially available polypropylene (PP) mesh was modified to minimize the risk of post-implantation infection. A dual drug-release coating was created around mesh filaments using an airbrush spray system. This coating was composed of three layers containing ofloxacin and rifampicin dispersed in a degradable polymer reservoir made up of [poly(ε-caprolactone) (PCL) and poly(DL-lactic acid) (PLA)]. Drug release kinetics were managed by varying the structure of the degradable polymer and the multilayer coating. In vitro, this new drug delivery polymer system was seen to be more rapidly invaded by fibroblasts than was the initial PP mesh. Active mesh showed excellent antibacterial properties with regard to microorganism adhesion, biofilm formation and the periprosthetic inhibition of bacterial growth. Sustained release of the two antibiotics from the coated mesh prevented mesh contamination for at least 72 h. This triple-layer coating technology is potentially of great interest for it can be easily extrapolated to other medical devices and drug combinations for the prevention or treatment of other diseases. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. The technology of preparing green coating by conducting micro-arc oxidation on AZ91D magnesium alloy

    Directory of Open Access Journals (Sweden)

    Wang Sheng

    2016-12-01

    Full Text Available Micro-arc oxidation was applied to AZ91D magnesium alloy by taking K2Cr2O7 as the colouring salt in the silicate system. It was shown that the green coating obtained through performing micro-arc oxidation on magnesium alloy consisted of Mg, Mg2SiO4, MgO, and MgCr2O4 based on analysis of X-ray diffraction (XRD, and scanning electron microscopy (SEM. Among which, MgCr2O4 was the colouring salt; there were something in the lamellar, pit, and convex forms found on the surface of the coating. The coating consisted of a porous, and a compact, layer from the outside to the inside. As demonstrated, the colour of the coating depended on the K2Cr2O7 concentration: it became gradually deeper with the addition of K2Cr2O7 and the increasing micro-arc oxidation time. The corrosion resistance and hardness of the green coating were greater than that of the matrix.

  16. Preparation and properties of thermal insulation coatings with a sodium stearate-modified shell powder as a filler

    Science.gov (United States)

    Tang, Qiang; Zhang, Ya-mei; Zhang, Pei-gen; Shi, Jin-jie; Tian, Wu-bian; Sun, Zheng-ming

    2017-10-01

    Waste shell stacking with odor and toxicity is a serious hazard to our living environment. To make effective use of the natural resources, the shell powder was applied as a filler of outdoor thermal insulation coatings. Sodium stearate (SS) was used to modify the properties of shell powder to reduce its agglomeration and to increase its compatibility with the emulsion. The oil absorption rate and the spectrum reflectance of the shell powder show that the optimized content of SS as a modifier is 1.5wt%. The total spectrum reflectance of the coating made with the shell powder that is modified at this optimum SS content is 9.33% higher than that without any modification. At the optimum SS content of 1.5wt%, the thermal insulation of the coatings is improved by 1.0°C for the cement mortar board and 1.6°C for the steel plate, respectively. The scouring resistance of the coating with the 1.5wt% SS-modified shell powder is three times that of the coating without modification.

  17. Reel-to-reel preparation of ion-beam assisted deposition (IBAD)-MgO based coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Kreiskott, Sascha; Arendt, Paul N; Coulter, J Yates; Dowden, Paul C; Foltyn, Stephen R; Gibbons, Brady J; Matias, Vladimir; Sheehan, Chris J [Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2004-05-01

    We report on our efforts in developing and scaling-up the systems for IBAD-MgO based coated conductor fabrication. The overall fabrication process involves a number of different processes including: electropolishing of the substrates; barrier-layer, seed-layer, and IBAD-MgO deposition by e-beam evaporation; and pulsed laser deposition of buffer and YBCO layers. All processes are realized in reel-to-reel processing systems. Latest results have shown that the IBAD-MgO approach yields coated conductor performance comparable to the best results achieved elsewhere to date.

  18. Preparation and characterization of Bioglass®-based scaffolds reinforced bypoly-vinyl alcohol/microfibrillated cellulose composite coating

    Czech Academy of Sciences Publication Activity Database

    Bertolla, Luca; Dlouhý, Ivo; Boccaccini, A. R.

    2014-01-01

    Roč. 34, č. 14 (2014), s. 3379-3387 ISSN 0955-2219. [Fractography of Advanced Ceramics IV. Smolenice Castle Congres Center, Smolenice SAS, 29.09.13-02.10.13] R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 EU Projects: European Commission(XE) 264526 - GLACERCO Institutional support: RVO:68081723 Keywords : bioceramcs * bioglass (R) scaffolds * porous materials * polymer coating * composite coating Subject RIV: JI - Composite Materials Impact factor: 2.947, year: 2014 http://www.imr.saske.sk/confer/fac2013/publication.htm

  19. Preparation and voltammetric characterization of electrodes coated with Langmuir-Schaefer ultrathin films of Nafion®

    Directory of Open Access Journals (Sweden)

    Bertoncello Paolo

    2003-01-01

    Full Text Available Ultrathin films of Nafion® perfluorinated polymer were deposited on indium-tin oxide electrodes (ITO by using Langmuir-Schaefer (LS technique, after optimization of the subphase composition conditions. Morphological characteristics of these coatings were obtained by Atomic Force Microscopy (AFM. Nafion® LS films showed a good uniformity and complete coverage of the electrode surface, however a different organization degree of the polymer layer was evidenced with respect to thin films deposited by spin-coating. ITO electrodes modified with Nafion® LS coatings preconcentrate by ion-exchange electroactive cations, such as Ru[(NH36]3+, dissolved in diluted solutions. The electroactive species is retained by the Nafion® LS coated ITO also after transfer of the modified electrode into pure supporting electrolyte. This allowed the use of the ruthenium complex as voltammetric probe to test diffusion phenomena within the Nafion® LS films. Apparent diffusion coefficients (Dapp of Ru[(NH36]3+ incorporated in Nafion® LS films were obtained by voltammetric measurements. Dapp values decrease slightly by increasing the amount of ruthenium complex incorporated in the ultrathin film. They are significantly lower than values typical for recasted Nafion® films, in agreement with the highly condensed nature of the Nafion® LS fims.

  20. Thin films of spin-crossover coordination polymers with large thermal hysteresis loops prepared by nanoparticle spin coating.

    Science.gov (United States)

    Tanaka, Daisuke; Aketa, Naoki; Tanaka, Hirofumi; Tamaki, Takashi; Inose, Tomoko; Akai, Tomoki; Toyama, Hirotaka; Sakata, Osami; Tajiri, Hiroo; Ogawa, Takuji

    2014-09-11

    This communication describes the synthesis of spin-crossover nanoparticles, which can disperse in various organic solvents without an excess amount of surfactants. The nanoparticles form homogeneous thin films on substrates by spin coating. The films show abrupt spin transitions with large thermal hysteresis loops.

  1. A rapid approach to prepare poly(2-methyl-2-oxazoline)-based antifouling coating by UV irradiation

    Science.gov (United States)

    Zhu, Haikun; Mumtaz, Fatima; Zhang, Chong; Tan, Lin; Liu, Songtao; Zhang, Yalin; Pan, Chao; Wang, Yanmei

    2017-12-01

    A series of brush copolymers, poly[(2-methyl-2-oxazoline)-random-4-vinylpyridine] (PMOXA-r-4VP), with a variety of compositions was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of the poly(2-methyl-2-oxazoline) methacrylate macromonomer (PMOXA-MA) and 4-vinylpyridine (4VP), and then characterized by 1H NMR spectroscopy and gel permeation chromatography (GPC). The PMOXA-based coatings on the surfaces of glass, silicon, gold and polydimethylsiloxane (PDMS) substrates were then produced by short-time ultraviolet (UV) irradiation of PMOXA-r-4VP. Water contact angel (WCA), ellipsometry, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and ζ-potential techniques were used to characterize the coatings. The results showed that copolymers can be successfully bonded on the surfaces of glass, silicon, gold, and PDMS substrate. Besides, the PMOXA-based coatings displayed a superior resistance to bovine serum albumin, human blood platelets, Human Umbilical Vein Endothelial Cells adsorption and good biocompatibility. Finally, stability test indicated that the stability of coatings can be improved with the content of the 4VP segment. Furthermore, PMOXA-r1/2-4VP immobilized surfaces displayed good antifouling property in long-term applications.

  2. Preparation of an orthodontic bracket coated with an nitrogen-doped TiO(2-x)N(y) thin film and examination of its antimicrobial performance.

    Science.gov (United States)

    Cao, Baocheng; Wang, Yuhua; Li, Na; Liu, Bin; Zhang, Yingjie

    2013-01-01

    A bracket coated with a nitrogen-doped (N-doped) TiO(2-x)N(y) thin film was prepared using the RF magnetron sputtering method. The physicochemical properties of the thin film were measured using X-ray diffraction and energy-dispersive X-ray spectrometry, while the antimicrobial activity of the bracket against common oral pathogenic microbes was assessed on the basis of colony counts. The rate of antimicrobial activity of the bracket coated with nano-TiO(2-x)N(y) thin film against Streptococcus mutans, Lactobacillus acidophilus, Actinomyces viscous, and Candida albicans was 95.19%, 91.00%, 69.44%, and 98.86%, respectively. Scanning electron microscopy showed that fewer microbes adhered to the surface of this newly designed bracket than to the surface of the normal edgewise bracket. The brackets coated with the N-doped TiO(2-x)N(y) thin film showed high antimicrobial and bacterial adhesive properties against normal oral pathogenic bacterial through visible light, which is effective in prevention of enamel demineralization and gingivitis in orthodontic patients.

  3. Preparation and characterization of multi-walled carbon nanotube/hydroxyapatite nanocomposite film dip coated on Ti–6Al–4V by sol–gel method for biomedical applications: An in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Abrishamchian, Alireza [Department of Dental Biomaterials, School of Dentistry/Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Hooshmand, Tabassom, E-mail: hoshmand@sina.tums.ac.ir [Department of Dental Biomaterials, School of Dentistry/Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Mohammadi, Mohammadreza [Department of Materials Science and Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Najafi, Farhood [Department of Resin and Additives, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of)

    2013-05-01

    In the present research, the introduction of multi-walled carbon nanotubes (MWCNTs) into the hydroxyapatite (HA) matrix and dip coating of nanocomposite on titanium alloy (Ti–6Al–4V) plate was conducted in order to improve the performance of the HA-coated implant via the sol–gel method. The structural characterization and electron microscopy results confirmed well crystallized HA–MWCNT coating and homogenous dispersion of carbon nanotubes in the ceramic matrix at temperatures as low as 500 °C. The evaluation of the mechanical properties of HA and HA/MWCNT composite coatings with different weight percentages of MWCNTs showed that the addition of low concentrations of MWCNTs (0.5 and 1 wt.%) had improved effect on the mechanical properties of nanocomposite coatings. Moreover, this in vitro study ascertained the biocompatibility of the prepared sol–gel-derived HA/MWCNT composite coatings. - Highlights: ► Carbon nanotube/hydroxyapatite composite was successfully dip-coated on Ti by sol–gel. ► Well-crystallized HA–MWCNT and homogenous dispersion of nanotubes were obtained. ► Low concentration of CNTs improved the mechanical properties of composite coating. ► Biocompatibility of the prepared sol–gel-derived HA/MWCNT films was ascertained.

  4. Preparation of Nano-TiO₂-Coated SiO₂ Microsphere Composite Material and Evaluation of Its Self-Cleaning Property.

    Science.gov (United States)

    Sun, Sijia; Deng, Tongrong; Ding, Hao; Chen, Ying; Chen, Wanting

    2017-11-03

    In order to improve the dispersion of nano-TiO₂ particles and enhance its self-cleaning properties, including photocatalytic degradation of pollutants and surface hydrophilicity, we prepared nano-TiO₂-coated SiO₂ microsphere composite self-cleaning materials (SiO₂-TiO₂) by co-grinding SiO₂ microspheres and TiO₂ soliquid and calcining the ground product. The structure, morphology, and self-cleaning properties of the SiO₂-TiO₂ were characterized. The characterization results showed that the degradation efficiency of methyl orange by SiO₂-TiO₂ was 97%, which was significantly higher than that obtained by pure nano-TiO₂. The minimum water contact angle of SiO₂-TiO₂ was 8°, indicating strong hydrophilicity and the good self-cleaning effect. The as-prepared SiO₂-TiO₂ was characterized by the nano-TiO₂ particles uniformly coated on the SiO₂ microspheres and distributed in the gap among the microspheres. The nano-TiO₂ particles were in an anatase phase with the particle size of 15-20 nm. The nano-TiO₂ particles were combined with SiO₂ microspheres via the dehydroxylation of hydroxyl groups on their surfaces.

  5. Preparation of Nano-TiO2-Coated SiO2 Microsphere Composite Material and Evaluation of Its Self-Cleaning Property

    Directory of Open Access Journals (Sweden)

    Sijia Sun

    2017-11-01

    Full Text Available In order to improve the dispersion of nano-TiO2 particles and enhance its self-cleaning properties, including photocatalytic degradation of pollutants and surface hydrophilicity, we prepared nano-TiO2-coated SiO2 microsphere composite self-cleaning materials (SiO2–TiO2 by co-grinding SiO2 microspheres and TiO2 soliquid and calcining the ground product. The structure, morphology, and self-cleaning properties of the SiO2–TiO2 were characterized. The characterization results showed that the degradation efficiency of methyl orange by SiO2–TiO2 was 97%, which was significantly higher than that obtained by pure nano-TiO2. The minimum water contact angle of SiO2–TiO2 was 8°, indicating strong hydrophilicity and the good self-cleaning effect. The as-prepared SiO2–TiO2 was characterized by the nano-TiO2 particles uniformly coated on the SiO2 microspheres and distributed in the gap among the microspheres. The nano-TiO2 particles were in an anatase phase with the particle size of 15–20 nm. The nano-TiO2 particles were combined with SiO2 microspheres via the dehydroxylation of hydroxyl groups on their surfaces.

  6. Preparation of Nano-TiO2-Coated SiO2 Microsphere Composite Material and Evaluation of Its Self-Cleaning Property

    Science.gov (United States)

    Sun, Sijia; Deng, Tongrong; Ding, Hao; Chen, Ying; Chen, Wanting

    2017-01-01

    In order to improve the dispersion of nano-TiO2 particles and enhance its self-cleaning properties, including photocatalytic degradation of pollutants and surface hydrophilicity, we prepared nano-TiO2-coated SiO2 microsphere composite self-cleaning materials (SiO2–TiO2) by co-grinding SiO2 microspheres and TiO2 soliquid and calcining the ground product. The structure, morphology, and self-cleaning properties of the SiO2–TiO2 were characterized. The characterization results showed that the degradation efficiency of methyl orange by SiO2–TiO2 was 97%, which was significantly higher than that obtained by pure nano-TiO2. The minimum water contact angle of SiO2–TiO2 was 8°, indicating strong hydrophilicity and the good self-cleaning effect. The as-prepared SiO2–TiO2 was characterized by the nano-TiO2 particles uniformly coated on the SiO2 microspheres and distributed in the gap among the microspheres. The nano-TiO2 particles were in an anatase phase with the particle size of 15–20 nm. The nano-TiO2 particles were combined with SiO2 microspheres via the dehydroxylation of hydroxyl groups on their surfaces. PMID:29099774

  7. PdNi- and Pd-coated electrodes prepared by electrodeposition from ionic liquid for nonenzymatic electrochemical determination of ethanol and glucose in alkaline media.

    Science.gov (United States)

    Huang, Hsin-Yi; Chen, Po-Yu

    2010-12-15

    Nonenzymatic electrochemical determination of ethanol and glucose was respectively achieved using PdNi- and Pd-coated electrodes prepared by electrodeposition from the novel metal-free ionic liquid (IL); N-butyl-N-methylpyrrolidinium dicyanamide (BMP-DCA). BMP-DCA provided an excellent environment and wide cathodic limit for electrodeposition of metals and alloys because many metal chlorides could dissolve in this IL where the reduction potentials of Pd(II) and Ni(II) indeed overlapped, leading to the convenience of potentiostatic codeposition. In aqueous solutions, the reduction potentials of Pd(II) and Ni(II) are considerably separated. The bimetallic PdNi coatings with atomic ratios of ∼ 80/20 showed the highest current for ethanol oxidation reaction (EOR). Ethanol was detected by either cyclic voltammetry (CV) or hydrodynamic amperometry (HA). Using CV, the dependence of EOR peak current on concentration was linear from 4.92 to 962 μM with a detection limit of 2.26 μM (σ=3), and a linearity was observed from 4.92 to 988 μM using HA (detection limit 0.83 μM (σ=3)). The Pd-coated electrodes prepared by electrodeposition from BMP-DCA showed electrocatalytic activity to glucose oxidation and CV, HA, and square-wave voltammetry (SWV) were employed to determine glucose. SWV showed the best sensitivity and linearity was observed from 2.86 μM to 107 μM, and from 2.99 mM to 10.88 mM with detection limits of 0.78 μM and 25.9 μM (σ=3), respectively. For glucose detection, the interference produced from ascorbic acid, uric acid, and acetaminophen was significantly suppressed, compared with a regular Pt disk electrode. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. [Simple method for the removal of the gelatin coating and the re-covering of histoautoradiographic preparations with an emulsion].

    Science.gov (United States)

    Veroman, S A

    1975-06-01

    This simple method is used for removing emulsion from unsuccessful histoautoradiographic preparations for putting a new layer of emulsion. For this purpose the old emulsion is solved in warm water, the silver residue is removed from the preparation surface with a 10% solution of potassium ferricyanide.

  9. Mechanical properties of titanium-hydroxyapatite (Ti-HA) composite coating on stainless steel prepared by thermal spraying

    Science.gov (United States)

    Rosmamuhamadani, R.; Azhar, N. H.; Talari, M. K.; Yahaya, Sabrina M.; Sulaiman, S.; Ismail, M. I. S.

    2017-09-01

    Addition of hydroxyapatite (HA) can enhance the bioactivity of the common metallic implant due to its similarity with natural bones and teeth. In this investigation, high velocity oxy-fuel (HVOFT) technique was used to deposit titanium-hydroxyapatite (Ti-HA) composite on stainless steel substrate plate with different percentage of HA for biomedical applications. The aim of this research is to investigate the mechanical properties of Ti-HA coating such as hardness, adhesion strength and wear behaviour. The hardness and strength was determined by using SHIMADZU-microhardness Vickers tester and PosiTest AT portable adhesion tester respectively. The wear test was performed by using pin-on-disk equipment and field emission scanning electron microscope (FESEM) used to determine the extent of surface damage. From the results obtained, mechanical properties such as hardness and adhesion strength of titanium (Ti) coating decreased with the increased of HA contents. Meanwhile, the coefficient of friction of Ti-10% HA coating shows the highest value compare to others as three-body abrasion had occurred during the test.

  10. Superhydrophobic SERS Substrates Based on Silver-Coated Reduced Graphene Oxide Gratings Prepared by Two-Beam Laser Interference.

    Science.gov (United States)

    Yan, Zhao-Xu; Zhang, Yong-Lai; Wang, Wei; Fu, Xiu-Yan; Jiang, Hao-Bo; Liu, Yu-Qing; Verma, Prabhat; Kawata, Satoshi; Sun, Hong-Bo

    2015-12-16

    Reported here is the fabrication of reduced graphene oxide (RGO) grating structures by two-beam laser interference (TBLI) for the development of highly efficient SERS substrates via simple physical vapor deposition (PVD) coating of silver. TBLI has been utilized to make hierarchical RGO grating structures with microscale gratings and nanoscale folders through a laser treatment induced ablation and photoreduction process. The hierarchical structures contribute to the formation of plasmonic structures after silver coating, giving rise to the formation of plenty of SERS "hot spots", while the RGO substrate would provide chemical enhancement of Raman signal through interaction with analytes molecules. The significantly increased roughness with respect to the hierarchical structures in combination with the removal of hydrophilic oxygen-containing groups endow the resultant substrates with unique superhydrophobicity, which leads to the enrichment of analytes and further lowers the detection limit. The synergistic effects make the silver coated RGO gratings a highly efficient SERS substrate; in the detection of Rhodamine B, our SERS substrates showed high SERS enhancement and good reproducibility, a detection limit of 10(-10) M has been achieved.

  11. Preparation, characterization, and in vitro and in vivo investigation of chitosan-coated poly (d,l-lactide-co-glycolide) nanoparticles for intestinal delivery of exendin-4

    Science.gov (United States)

    Wang, Mengshu; Zhang, Yong; Feng, Jiao; Gu, Tiejun; Dong, Qingguang; Yang, Xu; Sun, Yanan; Wu, Yongge; Chen, Yan; Kong, Wei

    2013-01-01

    Background Exendin-4 is an incretin mimetic agent approved for type 2 diabetes treatment. However, the required frequent injections restrict its clinical application. Here, the potential use of chitosan-coated poly (d,l-lactide-co-glycolide) (CS-PLGA) nanoparticles was investigated for intestinal delivery of exendin-4. Methods and results Nanoparticles were prepared using a modified water–oil–water (w/o/w) emulsion solvent-evaporation method, followed by coating with chitosan. The physical properties, particle size, and cell toxicity of the nanoparticles were examined. The cellular uptake mechanism and transmembrane permeability were performed in Madin-Darby canine kidney-cell monolayers. Furthermore, in vivo intraduodenal administration of exendin-4-loaded nanoparticles was carried out in rats. The PLGA nanoparticle coating with chitosan led to a significant change in zeta potential, from negative to positive, accompanied by an increase in particle size of ~30 nm. Increases in both the molecular weight and degree of deacetylation of chitosan resulted in an observable increase in zeta potential but no apparent change in the particle size of ~300 nm. Both unmodified PLGA and chitosan-coated nanoparticles showed only slight cytotoxicity. Use of different temperatures and energy depletion suggested that the cellular uptake of both types of nanoparticles was energy-dependent. Further investigation revealed that the uptake of PLGA nanoparticles occurred via caveolin-mediated endocytosis and that of CS-PLGA nanoparticles involved both macropinocytosis and clathrin-mediated endocytosis, as evidenced by using endocytic inhibitors. However, under all conditions, CS-PLGA nanoparticles showed a greater potential to be transported into cells, as shown by flow cytometry and confocal microscopy. Transmembrane permeability analysis showed that unmodified and modified PLGA nanoparticles could improve the transport of exendin-4 by up to 8.9- and 16.5-fold, respectively

  12. A facile method for the preparation of Covalent Triazine Framework coated monoliths as catalyst support - applications in C1 catalysis

    KAUST Repository

    Bavykina, Anastasiya V.

    2017-07-17

    A quasi Chemical Vapour Deposition method for the manufacturing of well-defined Covalent Triazine Framework (CTF) coatings on cordierite monoliths is reported. The resulting supported porous organic polymer is an excellent support for the immobilisation of two different homogeneous catalysts: 1) an IrIIICp*-based catalyst for the hydrogen production from formic acid, and 2) a PtII-based for the direct activation of methane via Periana chemistry. The immobilised catalysts display a much higher activity in comparison with the unsupported CTF operated in slurry because of improved mass transport. Our results demonstrate that CTF based catalysts can be further optimised by engineering at different length-scales.

  13. Electrochemical properties of nano-cobalt powder prepared by chemical reduction with and without cetyltrimethylammonium bromide and carbon-coated at 500 °C for secondary lithium Batteries

    Science.gov (United States)

    Hong, Seong-Hyeon; Jin, Yeong-Mi; Song, Myoung Youp

    2014-07-01

    X-ray diffraction patterns show that Co-based powders prepared by chemical reduction with and without Cetyltrimethylammonium bromide (CTAB, C19H42BrN) and carbon-coated at 500°C are not crystallized and amorphous-like as they are just after the chemical reduction. The Co-based powder prepared by chemical reduction with CTAB has carbon-coated layers with thicknesses of 15-20 nm. Comparing the 20% carbon-added powders, the powder prepared by chemical reduction with CTAB and carbon-coated at 500 °C has a larger first discharge capacity (about 1,230 mAh g-1) than the powder prepared by chemical reduction without CTAB and carbon-coated at 500 °C (about 902 mAh g-1). The reason is believed to be that the carbon layer obstructs the expansion of the Co phase and the formation of the solid electrolyte interface on the surface of the Co. Comparing the powders that are carbon-coated with CTAB added, the 20% carbon-added powder has a larger first discharge capacity (about 1,230 mAh g-1) than the 10% carbon-added powder (about 1,130 mAh g-1).

  14. Superparamagnetic Iron Oxide (Fe3O4 Nanoparticles Coated with PEG/PEI for Biomedical Applications: A Facile and Scalable Preparation Route Based on the Cathodic Electrochemical Deposition Method

    Directory of Open Access Journals (Sweden)

    Isa Karimzadeh

    2017-01-01

    Full Text Available Cathodic electrochemical deposition (CED is introduced as an efficient and effective method for synthesis and surface coating of superparamagnetic iron oxide nanoparticles (SPIONs. In this way, bare Fe3O4 nanoparticles were electrosynthesized through CED method from aqueous solution Fe3+ : Fe2+ chloride (molar ratio of 2 : 1. In the next step, the surface of NPs was coated with polyethyleneimine (PEI and polyethylene glycol (PEG during the CED procedure, and PEG/PEI coated SPIONs were obtained. The prepared NPs were evaluated by powder X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, dynamic light scattering (DLS, vibrating sample magnetometer (VSM, and field-emission scanning electron microscopy (FE-SEM. The pure magnetite phase and nanosize (about 15 nm of the prepared NPs were confirmed by XRD and FE-SEM. The presence of two coats (i.e., PEG and PEI on the surface of electrosynthesized NPs was proved via FTIR results. The percentage of polymer coat (37.5% on the NPs surface was provided by TGA analysis. The high magnetization value, negligible coercivity, and remanence measured by VSM indicate the superparamagnetic nature of both prepared NPs. The obtained results confirmed that the prepared Fe3O4 nanoparticles have suitable physicochemical and magnetic properties for biomedical applications.

  15. Deuterium permeation properties of Er{sub 2}O{sub 3}/Cr{sub 2}O{sub 3} composite coating prepared by MOCVD on 316L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yunyi, E-mail: wuyunyi@grinm.com [Department of Energy Materials and Technology, General Research Institute for Nonferrous Metals, Beijing (China); Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong (China); Wang, Shumao; Li, Shuai; He, Di; Liu, Xiaopeng; Jiang, Lijun [Department of Energy Materials and Technology, General Research Institute for Nonferrous Metals, Beijing (China); Huang, Haitao [Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong (China)

    2016-12-15

    Highlights: • Grain sizes of the coatings enlarged with increasing thickness of Cr{sub 2}O{sub 3} layer. • Er{sub 2}O{sub 3}/Cr{sub 2}O{sub 3} (80 nm) composite coating showed the maximum reduction in deuterium permeability. • The Er{sub 2}O{sub 3}/Cr{sub 2}O{sub 3} (80 nm) composite coating showed larger adhesion force value 9.2 N than the Er{sub 2}O{sub 3} coating. • Impurity layer formed at the interface of the Er{sub 2}O{sub 3} coating due to element diffusion. - Abstract: In this work, an Er{sub 2}O{sub 3}/Cr{sub 2}O{sub 3} composite coatings on 316L stainless steel were prepared by metalorganic chemical vapor deposition (MOCVD). Effect of Cr{sub 2}O{sub 3} layer on the microstructure, mechanical properties and deuterium permeation properties of Er{sub 2}O{sub 3} coating was investigated. It was found grain sizes of the coatings enlarged with increasing the thickness of Cr{sub 2}O{sub 3} layer. The Er{sub 2}O{sub 3}/Cr{sub 2}O{sub 3} (80 nm) composite coating showed larger adhesion force value 9.2 N than the Er{sub 2}O{sub 3} coating. The Cr{sub 2}O{sub 3} layer adding could significantly enhance the deuterium permeation inhibition property of the coatings. The single-layer Er{sub 2}O{sub 3} coating exhibited the minimum reduction in deuterium permeability, and the permeation reduction factor (PRF) values were in the range of 95–146 at 823–973 K. The maximum reduction in deuterium permeability was obtained from the Er{sub 2}O{sub 3}/Cr{sub 2}O{sub 3} (80 nm) composite coating, and the PRF values were in the range of 463–206 at 823–973 K. With further increasing thickness of the Cr{sub 2}O{sub 3} layer to 120 nm, the hydrogen permeation inhibition performance of the composite coating lower instead. Furthermore, apparent delamination of coating was illustrated on the single-layer Er{sub 2}O{sub 3} coating after the permeation measurement, and this might be the main reason for the transformation to diffusion limiting process.

  16. Preparation and evaluation of enteric-coated delayed-release pellets of duloxetine hydrochloride using a fluidized bed coater.

    Science.gov (United States)

    Kim, Yong-Il; Pradhan, Roshan; Paudel, Bijay K; Choi, Ju Yeon; Im, Ho Taek; Kim, Jong Oh

    2015-12-01

    In this study, the enteric-coated delayed-release pellets of duloxetine hydrochloride (DLX) were formulated using a fluidized bed coater. Three separate layers, the drug layer, the barrier layer, and the enteric layer, were coated onto inert core pellets. Among the three formulations (F1-F3), the dissolution profiles of formulation F2 were most similar to those of the marketed product, with similarity and difference factors of 83.99 and 3.77, respectively. In addition, pharmacokinetic parameters of AUC, C(max), T(max), t(1/2), K(el), and MRT of DLX for the developed formulation (F2) did not differ significantly from those for the marketed product in beagle dogs, suggesting that they were bioequivalent. Our results demonstrated that the in vitro dissolution data resembled the in vivo performance of the drug. Therefore, this study has a positive scope for further scale up and development of the formulation for achievement of the generic product.

  17. Preparation of graphene-coated solid-phase microextraction fiber and its application on organochlorine pesticides determination.

    Science.gov (United States)

    Ke, Yuanyuan; Zhu, Fang; Zeng, Feng; Luan, Tiangang; Su, Chengyong; Ouyang, Gangfeng

    2013-07-26

    The coating material determines the sensitivity and selectivity of solid-phase microextraction (SPME). Graphene is predicted to have remarkable properties, such as high thermal conductivity, superior mechanical properties, excellent electronic transport properties and good extraction ability. In this work we immobilized the graphene onto a stainless steel wire to obtain a novel SPME coating based on sol-gel technique. The new fiber possessed a homogeneous, porous surface and showed excellent thermal and solvent stability. Under the optimized conditions, its extraction efficiencies for seven organochlorine pesticides (OCPs) were higher than those of two commercial fibers (PDMS, 85μm; PDMS/DVB, 65μm). Using the self-made sol-gel-graphene SPME fiber, the limits of detections for seven OCPs were found to be ranged from 0.19ngL(-1) (o,p-DDT) to 18.3ngL(-1) (heptachlor). The repeatabilities for each single fiber were evaluated and the relative standard deviations (RSDs) ranged from 4.7% to 10.6%. The reproducibilities of fiber-to-fiber were 2.3-13.6%. The developed method was successfully applied to the determination of OCPs in rainwater. Hexachlorobenzene (62.7ng/L), trans-chlordance (79.6ng/L) and p,p-DDT (9.30ng/L) were detected. The relative recoveries ranged from 77.7% to 120%. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Preparation and characterization of metal-organic framework MIL-101(Cr)-coated solid-phase microextraction fiber.

    Science.gov (United States)

    Xie, Lijun; Liu, Shuqin; Han, Zhubing; Jiang, Ruifen; Liu, Hong; Zhu, Fang; Zeng, Feng; Su, Chengyong; Ouyang, Gangfeng

    2015-01-01

    Metal-organic frameworks (MOFs) have received great attention as novel sorbents due to their fascinating structures and intriguing potential applications in various fields. In this work, a MIL-101(Cr)-coated solid-phase microextraction (SPME) fiber was fabricated by a simple direct coating method and applied to the determination of volatile compounds (BTEX, benzene, toluene, ethylbenzene, m-xylene and o-xylene) and semi-volatile compounds (PAHs, polycyclic aromatic hydrocarbons) from water samples. The extraction and desorption conditions of headspace SPME (HS-SPME) were optimized. Under the optimized conditions, the established methods exhibited excellent extraction performance. Good precision (river water by coupling with gas chromatography-mass spectrometry (GC-MS). The analytes at low concentrations (1.7 and 10 ng L(-1)) were detected, and the recoveries obtained with the spiked river water samples were in the range of 80.0-113% and 84.8-106% for BTEX and PAHs, respectively, which demonstrated the applicability of the self-made fiber. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Preparation and Characterization of Inulin Coated Gold Nanoparticles for Selective Delivery of Doxorubicin to Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Mariano Licciardi

    2016-01-01

    Full Text Available A novel folate-targeted gold-based nanosystem for achieving selectivity towards folate receptor (FR positive cells is proposed, by virtue of the fact that the FR is a molecularly targeted entity overexpressed in a wide spectrum of solid tumors. A new inulin-folate derivative (INU-FA has been synthesized to act as coating agent for 40 nm gold nanoparticles. The obtained polymer-coated gold nanoparticles (Au@INU-FA were characterized in terms of hydrodynamic radius, shape, zeta potential, and aqueous stability and were loaded with doxorubicin (Au@INU-FA/Doxo. Its release capability was tested in different release media. The selectivity of Au@INU-FA/Doxo system towards FRs-positive cancer cells was proved by the differences in the quantitative uptake using human breast cancer MCF7 as FR-positive cells and 16HBE epithelial as noncancer cell line. Furthermore, the folate-mediated uptake mechanism was studied by FRs-blocking experiments. On the whole Au@INU-FA/Doxo was able to be preferentially internalized into MCF7 cells proving a folate-mediated endocytosis mechanism which allowed a higher and selective cytotoxic effect towards cancer cells. The cytotoxicity profile was evaluated on both cancer and noncancer cell lines, displaying that folate-mediated targeting implied advantageous therapeutic effects, such as amplified drug uptake and increased anticancer activity towards MCF7 cancer cells.

  20. Structural and Magnetic Properties of Nanopowders and Coatings of Carbon-Doped Zinc Oxide Prepared by Pulsed Electron Beam Evaporation

    Directory of Open Access Journals (Sweden)

    V. G. Il’ves

    2017-01-01

    Full Text Available With the help of electron beam evaporation of mechanical mixtures of nonmagnetic micron powders ZnO and carbon in vacuum with the subsequent annealing of evaporation products in air at the temperature of 773 K, single-phase crystal nanopowders ZnO-C were produced with the hexagonal wurtzite structure and low content of the carbon dopant not exceeding 0.25 wt%. It was established that doping ZnO with carbon stimulates primary growth of nanoparticles along the direction 0001 in the coatings. Nanocrystal growth in coatings occurs in the same way as crystal growth in thin films, with growth anisotropy in the c-axis direction in wurtzite ZnO. Element mapping has confirmed homogeneous distribution of carbon in ZnO lattice. Ferromagnetism of single-phase crystal nanopowders ZnO-C with the hexagonal wurtzite structure and low content of the carbon dopant not exceeding 0.25 wt% was produced at room temperature. Ferromagnetic response of the doped NP ZnO-C has exceeded the ferromagnetic response of pure NP ZnO 5 times. The anhysteretic form of magnetization curves NP ZnO-C indicates aspiration of samples to superparamagnetism manifestation.

  1. A controlled wet-spinning and dip-coating process for preparation of high-permeable TiO2 hollow fiber membranes.

    Science.gov (United States)

    Zhang, Qi; Wang, Hua; Fan, Xinfei; Chen, Shuo; Yu, Hongtao; Quan, Xie

    2016-01-01

    In order to improve the permeate flux of photocatalytic membranes, we present an approach for coupling TiO2 with ceramic hollow fiber membranes. The ceramic hollow fiber membranes with high permeate flux were fabricated by a controlled wet-spinning process using polyethersulfone (PESf) and ceramic powder as precursors and 1-methyl-2-pyrrolidinone as solvent, and the subsequent TiO2 coating was performed by a dip-coating process using tetra-n-butyl titanate as precursor. It has been found that the PESf/ceramic powder ratio could influence the structure of the membranes. Here the as-prepared TiO2 hollow fiber membranes had a pure water flux of 4,450 L/(m(2)·h). The performance of the TiO2 hollow fiber membrane was evaluated using humic acid (HA) as a test substance. The results demonstrated that this membrane exhibited a higher permeate flux under UV irradiation than in the dark and the HA removal efficiency was enhanced. The approach described here provides an operable route to the development of high-permeable photocatalytic membranes for water treatment.

  2. Preparation of ciprofloxacin-coated zinc oxide nanoparticles and their antibacterial effects against clinical isolates of Staphylococcus aureus and Escherichia coli

    DEFF Research Database (Denmark)

    Seif, Sepideh; Kazempour, Zarah Bahri; Pourmand, Mohammad Reza

    2011-01-01

    that the carbonyl group in ciprofloxacin is actively involved in forming chemical - rather than physical - bonds with zinc oxide nanoparticles. Also the antibacterial activity of free zinc oxide nanoparticles and ciprofloxacin-coated zinc oxide nanoparticles have been evaluated against different clinical isolates......In the present research study, ciprofloxacincoated zinc oxide nanoparticles were prepared using a precipitation method. The nature of interactions between zinc oxide nanoparticles and ciprofloxacin (CAS 85721-33-1) was studied by Fourier transform infrared spectroscopy. The results show...... of Staphylococcus aureus and Escherichia coli. The free zinc oxide nanoparticles did not show potent antibacterial activity against all test strains. In contrast, only the low concentrations of ciprofloxacincoated zinc oxide nanoparticles (equivalent to the sub-minimum inhibitory concentrations of pure...

  3. Effect of different sound atmospheres on SnO2:Sb thin films prepared by dip coating technique

    Science.gov (United States)

    Kocyigit, Adem; Ozturk, Erhan; Ejderha, Kadir; Turgut, Guven

    2017-11-01

    Different sound atmosphere effects were investigated on SnO2:Sb thin films, which were deposited with dip coating technique. Two sound atmospheres were used in this study; one of them was nay sound atmosphere for soft sound, another was metallic sound for hard sound. X-ray diffraction (XRD) graphs have indicated that the films have different orientations and structural parameters in quiet room, metallic and soft sound atmospheres. It could be seen from UV-Vis spectrometer measurements that films have different band gaps and optical transmittances with changing sound atmospheres. Scanning electron microscope (SEM) and AFM images of the films have been pointed out that surfaces of films have been affected with changing sound atmospheres. The electrical measurements have shown that films have different I-V plots and different sheet resistances with changing sound atmospheres. These sound effects may be used to manage atoms in nano dimensions.

  4. Improving the direct electron transfer in monolithic bioelectrodes prepared by immobilization of FDH enzyme on carbon-coated anodic aluminum oxide films

    Science.gov (United States)

    Castro-Muñiz, Alberto; Hoshikawa, Yasuto; Komiyama, Hiroshi; Nakayama, Wataru; Itoh, Tetsuji; Kyotani, Takashi

    2016-02-01

    The present work reports the preparation of binderless carbon-coated porous films and the study of their performance as monolithic bioanodes. The films were prepared by coating anodic aluminum oxide (AAO) films with a thin layer of nitrogen-doped carbon by chemical vapor deposition. The films have cylindrical straight pores with controllable diameter and length. These monolithic films were used directly as bioelectrodes by loading the films with D-fructose dehydrogenase (FDH), an oxidoreductase enzyme that catalyzes the oxidation of D-fructose to 5-keto-D-fructose. The immobilization of the enzymes was carried out by physical adsorption in liquid phase and with an electrostatic attraction method. The latter method takes advantage of the fact that FDH is negatively charged during the catalytic oxidation of fructose. Thus the immobilization was performed under the application of a positive voltage to the CAAO film in a FDH-fructose solution in McIlvaine buffer (pH 5) at 25 ºC. As a result, the FDH modified electrodes with the latter method show much better electrochemical response than that with the conventional physical adsorption method. Due to the singular porous structure of the monolithic films, which consists of an array of straight and parallel nanochannels, it is possible to rule out the effect of the diffusion of the D-fructose into the pores. Thus the improvement in the performance upon using the electrostatic attraction method can be ascribed not only to a higher uptake, but also to a more appropriate molecule orientation of the enzyme units on the surface of the electrodes.

  5. Preparation of a small intestinal submucosa modified polypropylene hybrid mesh via a mussel-inspired polydopamine coating for pelvic reconstruction.

    Science.gov (United States)

    Ge, Liangpeng; Liu, Lubin; Wei, Haoche; Du, Lei; Chen, Shixuan; Huang, Yong; Huang, Renshu

    2016-04-01

    Pelvic organ prolapse (POP) is a serious health issue that affects many adult women. Surgical treatments for POP patients comprise a common strategy in which scaffold materials are used to reconstruct the prolapsed pelvic. However, the existing materials for pelvic reconstruction cannot meet clinical requirements in terms of biocompatibility, mechanics and immunological rejection. To address these concerns, polypropylene (PP) mesh was selected because of its strong mechanical properties. Small intestinal submucosa (SIS) was used to modify the PP mesh via a mussel-inspired polydopamine coating to enhance its biocompatibility. The scanning electron microscopy (SEM) and atomic force microscopy (AFM) results demonstrated that SIS was successfully conjugated on the surface of the PP mesh. Moreover, the cytotoxicity results indicated that the PP mesh and SIS-modified PP mesh were safe to use. Furthermore, in vivo tests demonstrated that the fibroplasia around the implanted site in the SIS-modified PP mesh group was significantly less than the fibroplasia around the PP mesh group. In addition, the immunohistochemistry staining results indicated that the expression of pro-inflammatory macrophages (M1) was substantially lower and that the expression of pro-healing macrophages (M2) was higher in the SIS-modified PP mesh group. Furthermore, ELISA detection indicated that the expression of IL-1β and IL-6 in the SIS-modified PP mesh group was reduced compared with the PP mesh group. These findings suggest that a SIS-modified polypropylene hybrid mesh via a mussel-inspired polydopamine coating is a promising approach in pelvic reconstruction. © The Author(s) 2016.

  6. Preparation of Mn-Containing Mixed-Oxide Thin Films by a Dip-Coating Method Using Metal Naphthenates

    National Research Council Canada - National Science Library

    KANEKO, Shoji; SUGIYAMA, Susumu; MAZUKA, Naoto; MURAKAMI, Kenji; YAMADA, Tamotsu

    1994-01-01

    ...) The as-prepared thin film almost completely crystallized to form a complex spinel phase, a solid solution of MnCo2O4 and NiMn2O4, by further heat treatment at temperatures above 700°C for 1h. (4...

  7. Preparation and characterization of aluminum oxide nanoparticles by laser ablation in liquid as passivating and anti-reflection coating for silicon photodiodes

    Science.gov (United States)

    Ismail, Raid A.; Zaidan, Shihab A.; Kadhim, Rafal M.

    2017-10-01

    In this study, we have prepared aluminum oxide (Al2O3 nanoparticles) NPs with size ranging from 50 to 90 nm by laser ablation of aluminum target in ethanol. The effect of laser fluence on the structural, morphological and optical properties of Al2O3 was demonstrated and discussed. X-ray diffraction XRD results confirm that the synthesized Al2O3 NPs are crystalline in nature. The sample prepared at 3.5 J/cm2/pulse exhibits single phase of γ-Al2O3, while the XRD patterns of the nanoparticles synthesized at 5.3 and 7.5 J/cm2/pulse show the co-existence of the α-Al2O3 and γ-Al2O3 phases. Nanostructured Al2O3 films have been used as anti-reflecting coating and surface passivation layer to improve the photoresponse characteristics of silicon photodiode. The experimental data showed that the optical energy gap decreases from 5.3 to 5 eV as the laser fluence increases from 3.5 to 7.3 J/cm2. The lowest optical reflectivity was found for silicon photodiode deposited with a single layer of Al2O3 prepared at 3.5 J/cm2/pulse. The effect of laser fluence on the refractive index and extinction coefficient of the nanostructured Al2O3 film was studied. The photosensitivity of the silicon photodiode increased from 0.4 to 1.4 AW-1 at 800 nm after depositing Al2O3 prepared at 3.5 J/cm2/pulse, followed by rapid thermal annealing at 400 °C for 60 s.

  8. Molecularly imprinted polymer coated solid-phase microextraction fiber prepared by surface reversible addition-fragmentation chain transfer polymerization for monitoring of Sudan dyes in chilli tomato sauce and chilli pepper samples.

    Science.gov (United States)

    Hu, Xiaogang; Fan, Yanan; Zhang, Yi; Dai, Guimei; Cai, Quanling; Cao, Yujuan; Guo, Changjuan

    2012-06-20

    Surface reversible addition-fragmentation chain transfer (RAFT) polymerization method was firstly applied to the preparation of molecularly imprinted polymer (MIP) coated silicon solid-phase microextraction (SPME) fibers. With Sudan I as template, an ultra-thin MIP coating with about 0.55-μm thickness was obtained with homogeneous structure and controlled composition, due to the controllable radical growing and chain propagation in surface RAFT polymerization. The MIP-coated fibers were found with enhanced selectivity coefficients (3.0-6.5) to Sudan I-IV dyes in contrast with those reported in our previous work. Furthermore, the ultra-thin thickness of MIP coating was helpful to the effective elution of template and fast adsorption/desorption kinetics, so only about 18 min was needed for MIP-coated SPME operation. The detection limits of 21-55 ng L(-1) were achieved for four Sudan dyes, when MIP-coated SPME was coupled with liquid chromatography (LC) and mass spectrometry (MS) detection. The MIP-coated SPME-LC-MS/MS method was tested for the monitoring of ultra trace Sudan dyes in spiked chilli tomato sauce and chilli pepper samples, and high enrichment effect, remarkable matrix peaks-removing capability, and consequent high sensitivities were achieved to four Sudan dyes. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Investigating the Inter-Tube Conduction Mechanism in Polycarbonate Nanocomposites Prepared with Conductive Polymer-Coated Carbon Nanotubes

    KAUST Repository

    Ventura, Isaac Aguilar

    2015-12-16

    A well-known strategy to improve the electrical conductivity of polymers is to dope them with high-aspect-ratio and conductive nanoparticles such as carbon nanotubes (CNTs). However, these nanocomposites also exhibit undesirable properties such as damage-sensitive and history-dependent conductivity because their macroscopic electrical conductivity is largely determined by the tunneling effect at the tube/tube interface. To reduce these issues, new nanocomposites have been developed with CNTs that have been coated with a conductive layer of poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT/PSS). It has been posited that the insulating region between the CNTs is replaced by a conductive polymer bridge; this has not been proven up to now. We propose here to investigate in-depth how the macroscopic conductivity of these materials is changing when (1) varying the frequency of the electrical loading (impedance spectroscopy), (2) varying the mechanical hydrostatic pressure, and (3) varying the voltage of the electrical loading. The response is systematically compared to the one of conventional carbon nanotube/polycarbonate (CNT/PC) nanocomposites so we can clarify how efficiently the tunneling effect is suppressed from these composites. The objective is to elucidate further the mechanism for conduction in such material formulations.

  10. Preparation and evaluation of APTES-PEG coated iron oxide nanoparticles conjugated to rhenium-188 labeled rituximab.

    Science.gov (United States)

    Azadbakht, Bakhtiar; Afarideh, Hossein; Ghannadi-Maragheh, Mohammad; Bahrami-Samani, Ali; Asgari, Mehdi

    2017-05-01

    Radioimmuno-conjugated (Rhenium-188 labeled Rituximab), 3-aminopropyltriethoxysilane (APTES)-polyethylene glycol (PEG) coated iron oxide nanoparticles were synthesized and then characterized. Therapeutic effect and targeting efficacy of complex were evaluated in CD20 express B cell lines and tumor bearing Balb/c mice respectively. To reach these purposes, superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized using coprecipitation method and then their surface was treated with APTES for increasing retention time of SPIONs in blood circulation and amine group creation. In the next step, N-hydroxysuccinimide (NHS) ester of polyethylene glycol maleimide (NHS-PEG-Mal) was conjugated to the APTES-treated SPIONs. After radiolabeling of Rituximab antibody with Rhenium-188 (T1/2=16.9h) using synthesized N2S4 chelator, it was attached to the APTES-PEG-MAL-SPIONs surface through thiol-maleimide coupling reaction. In vitro evaluation of the (188)ReN2S4-Rituximab-SPION-complex thus obtained revealed that at 24 and 48h post-treatment effective cancer cell killing had been achieved. Bio-distribution study in tumor bearing mice showed capability of this complex for targeted cancer therapy. Active and passive tumor targeting strategies were applied through incorporated anti-CD20 (Rituximab) antibody and also enhanced permeability and retention (EPR) effect of solid tumors for nanoparticles respectively. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Prepare dispersed CIS nano-scale particles and spray coating CIS absorber layers using nano-scale precursors

    Science.gov (United States)

    Liou, Jian-Chiun; Diao, Chien-Chen; Lin, Jing-Jenn; Chen, Yen-Lin; Yang, Cheng-Fu

    2014-01-01

    In this study, the Mo-electrode thin films were deposited by a two-stepped process, and the high-purity copper indium selenide-based powder (CuInSe2, CIS) was fabricated by hydrothermal process by Nanowin Technology Co. Ltd. From the X-ray pattern of the CIS precursor, the mainly crystalline phase was CIS, and the almost undetectable CuSe phase was observed. Because the CIS powder was aggregated into micro-scale particles and the average particle sizes were approximately 3 to 8 μm, the CIS power was ground into nano-scale particles, then the 6 wt.% CIS particles were dispersed into isopropyl alcohol to get the solution for spray coating method. Then, 0.1 ml CIS solution was sprayed on the 20 mm × 10 mm Mo/glass substrates, and the heat treatment for the nano-scale CIS solution under various parameters was carried out in a selenization furnace. The annealing temperature was set at 550°C, and the annealing time was changed from 5 to 30 min, without extra Se content was added in the furnace. The influences of annealing time on the densification, crystallization, resistivity ( ρ), hall mobility ( μ), and carrier concentration of the CIS absorber layers were well investigated in this study.

  12. Removal of fluoride from drinking water using aluminum hydroxide coated activated carbon prepared from bark of Morinda tinctoria

    Science.gov (United States)

    Amalraj, Augustine; Pius, Anitha

    2017-10-01

    The aim of this study is to design and develop a novel cost effective method for fluoride removal, applicable to rural areas of developing countries. Adsorption is widely considered as one of the appropriate technologies for water defluoridation. This study investigates the feasibility of using low-cost biomass based activated carbon from the bark of Morinda tinctoria coated with aluminum hydroxide (AHAC) for water defluoridation, at neutral pH range. Characterization of AHAC was done through IR, SEM with EDAX studies before and after fluoride treatment. The fluoride adsorption capacity of AHAC as a function of contact time, pH and initial fluoride concentration was investigated. The role of co-existing interfering ions also was studied. The isotherm and kinetic models were used to understand the nature of the fluoride adsorption onto AHAC. Freundlich isotherm and intra-particle diffusion were the best-fitting models for the adsorption of fluoride on AHAC. Fluoride adsorption kinetics well fitted with pseudo-second order model. The results showed excellent fluoride adsorption capacity was found to be 26.03 mg g-1 at neutral pH.

  13. Photoelectrolytic hydrogen production using Bi{sub 2}MNbO{sub 7} (M = Al, Ga) semiconductor film electrodes prepared by dip-coating

    Energy Technology Data Exchange (ETDEWEB)

    Rosas-Barrera, K.L. [Grupo de Investigaciones en Minerales, Biohidrometalurgia y Ambiente - GIMBA, Universidad Industrial de Santander - UIS, Sede Guatiguara, Km. 2 via El Refugio, C.P. 681011, Piedecusta, Santander (Colombia); Pedraza-Avella, J.A. [Centro de Investigaciones en Catalisis - CICAT, Universidad Industrial de Santander - UIS, Sede Guatiguara, Km. 2 via El Refugio, C.P. 681011, Piedecuesta, Santander (Colombia); Ballen-Gaitan, B.P.; Cortes-Pena, J.; Pedraza-Rosas, J.E. [Grupo de Investigaciones en Minerales, Biohidrometalurgia y Ambiente - GIMBA, Universidad Industrial de Santander - UIS, Sede Guatiguara, Km. 2 via El Refugio, C.P. 681011, Piedecusta (Santander) (Colombia); Laverde-Catano, D.A., E-mail: dlaverde@uis.edu.co [Grupo de Investigaciones en Minerales, Biohidrometalurgia y Ambiente - GIMBA, Universidad Industrial de Santander - UIS, Sede Guatiguara, Km. 2 via El Refugio, C.P. 681011, Piedecusta, Santander (Colombia)

    2011-10-25

    The performance of Bi{sub 2}MNbO{sub 7} (M = Al, Ga) films on AISI/SAE 304 stainless steel was evaluated in the photoelectrochemical hydrogen production as a function of the annealing temperature of the films (400, 500 and 600 deg. C) and the composition of the electrolyte solution (containing KOH, KCN and KCl). The films were prepared by sol-gel dip-coating on AISI/SAE 304 stainless steel followed by a thermal annealing. The photoelectrochemical evaluation (UV-Vis, 2.5 V) was carried out in a conventional two-compartment electrochemical cell by using the prepared films as photoanode and a silver plate as cathode. During the process, circulating current was recorded and hydrogen production and cyanide degradation were measured. In both cases, it was found that the higher activity was obtained with the films annealed at 500 deg. C and using an electrolyte solution 0.3 M of KOH and 120 ppm of CN{sup -}. Further works on the subject should involve a cathode evaluation to avoid the electrode polarization in presence of KCl and an experimental design to optimize the evaluated variables.

  14. The impact of selected preparations of trace elements - magnesium, potassium, calcium, and zinc on the release of diclofenac sodium from enteric coated tablets and from sustained release capsules.

    Science.gov (United States)

    Biernat, Paweł; Musiał, Witold; Gosławska, Dorota; Pluta, Janusz

    2014-01-01

    In an aging society, many patients require long-term treatment. This fact is associated clearly with the simultaneous occurrence of lifestyle diseases such as hypertension, diabetes, and even osteoarthritis. Concomitant medications, which are a common practice, pose a major threat of an interaction between these drugs. Very popular now "fast way of life" that makes people have less and less time to prepare well-balanced meals of high nutritional value. The result of this lifestyle is an increased need for supplementation preparations necessary vitamins and minerals. Given the wide availability of dietary supplements (shops, kiosks, petrol stations) raises the question about the possibility of an interaction between the uncontrolled intake of dietary supplements and medications received in the most common diseases of civilization. The aim of this study was to investigate the effect of the most important minerals (magnesium, potassium, calcium, zinc) contained in the popular nutritional supplements, the release also often used as an anti-pain, anti-inflammatory, diclofenac sodium from the different formulations. Among the many as sodium diclofenac selected two most common: film-coated tablets and sustained release capsules. The study showed a significant effect of minerals on the release of diclofenac sodium and differences that impact, depending on the test form of the drug.

  15. Preparation and Evaluation of Diclofenac Sodium Tablet Coated with Polyelectrolyte Multilayer Film Using Hypromellose Acetate Succinate and Polymethacrylates for pH-Dependent, Modified Release Drug Delivery.

    Science.gov (United States)

    Jeganathan, Balamurugan; Prakya, Vijayalakshmi; Deshmukh, Abhijit

    2016-06-01

    Polyelectrolyte multilayer (PEM) film formed due to the electrostatic interaction between oppositely charged polyelectrolytes is of considerable interest because of their potential applications as both drug carriers and surface-modifying agents. In this study, in vitro studies were carried out on polyelectrolyte complexes formulated with Eudragit E (EE) and hypromellose acetate succinate (HPMCAS). The complexes of EE and HPMCAS were formulated by non-stoichiometric method. The prepared IPCs were investigated using Fourier transform infrared spectroscopy. Diclofenac sodium (DS) tablets were prepared and were coated with polymer solution of HPMCAS and EE to achieve pH-dependent and sustained-release tablets. Tablets were evaluated for their physical characteristics and in vitro drug release. The results of pharmacokinetic studies in rabbits showed that the selected formulation (F6) exhibited a delayed peak plasma concentration and marked sustained-release effect of drug in the in vivo drug release in comparison with marketed tablet. The suitable combination of PEM film based on EE and HPMCAS demonstrated potential candidate for targeted release of DS in the lower part of the gastrointestinal (GI) tract.

  16. Glucose-coated superparamagnetic iron oxide nanoparticles prepared by metal vapour synthesis are electively internalized in a pancreatic adenocarcinoma cell line expressing GLUT1 transporter.

    Science.gov (United States)

    Barbaro, Daniele; Di Bari, Lorenzo; Gandin, Valentina; Evangelisti, Claudio; Vitulli, Giovanni; Schiavi, Eleonora; Marzano, Cristina; Ferretti, Anna M; Salvadori, Piero

    2015-01-01

    Iron oxide nanoparticles (IONP) can have a variety of biomedical applications due to their visualization properties through Magnetic Resonance Imaging (MRI) and heating with radio frequency or alternating magnetic fields. In the oncological field, coating IONP with organic compounds to provide specific features and to achieve the ability of binding specific molecular targets appears to be very promising. To take advantage of the high avidity of tumor cells for glucose, we report the development of very small glucose-coated IONP (glc-IONP) by employing an innovative technique, Metal Vapor Synthesis (MVS). Moreover, we tested the internalization of our gl-IONP on a tumor line, BxPC3, over-expressing GLUT 1 transporter. Both glc-IONP and polyvinylpyrrolidone-IONP (PVP-IONP), as control, were prepared with MVS and were tested on BxPC3 at various concentrations. To evaluate the role of GLUT-1 transporter, we also investigated the effect of adding a polyclonal anti-GLUT1 antibody. After proper treatment, the iron value was assessed by atomic absorption spectrometer, reported in mcg/L and expressed in mg of protein. Our IONP prepared with MVS were very small and homogeneously distributed in a narrow range (1.75-3.75 nm) with an average size of 2.7 nm and were super-paramagnetic. Glc-IONP were internalized by BxPC3 cells in a larger amount than PVP-IONP. After 6h of treatment with 50 mcg/mL of IONPs, the content of Fe was 1.5 times higher in glc-IONP-treated cells compared with PVP-IONP-treated cells. After 1h pre-treatment with anti-GLUT1, a reduction of 41% cellular accumulation of glc-IONP was observed. Conversely, the uptake of PVP-IONPs was reduced only by 14% with antibody pretreatment. In conclusion, MVS allowed us to prepare small, homogeneous, super-paramagnetic glc-IONP, which are electively internalized by a tumor line over-expressing GLUT1. Our glc-IONP appear to have many requisites for in vivo use.

  17. Glucose-coated superparamagnetic iron oxide nanoparticles prepared by metal vapour synthesis are electively internalized in a pancreatic adenocarcinoma cell line expressing GLUT1 transporter.

    Directory of Open Access Journals (Sweden)

    Daniele Barbaro

    Full Text Available Iron oxide nanoparticles (IONP can have a variety of biomedical applications due to their visualization properties through Magnetic Resonance Imaging (MRI and heating with radio frequency or alternating magnetic fields. In the oncological field, coating IONP with organic compounds to provide specific features and to achieve the ability of binding specific molecular targets appears to be very promising. To take advantage of the high avidity of tumor cells for glucose, we report the development of very small glucose-coated IONP (glc-IONP by employing an innovative technique, Metal Vapor Synthesis (MVS. Moreover, we tested the internalization of our gl-IONP on a tumor line, BxPC3, over-expressing GLUT 1 transporter. Both glc-IONP and polyvinylpyrrolidone-IONP (PVP-IONP, as control, were prepared with MVS and were tested on BxPC3 at various concentrations. To evaluate the role of GLUT-1 transporter, we also investigated the effect of adding a polyclonal anti-GLUT1 antibody. After proper treatment, the iron value was assessed by atomic absorption spectrometer, reported in mcg/L and expressed in mg of protein. Our IONP prepared with MVS were very small and homogeneously distributed in a narrow range (1.75-3.75 nm with an average size of 2.7 nm and were super-paramagnetic. Glc-IONP were internalized by BxPC3 cells in a larger amount than PVP-IONP. After 6h of treatment with 50 mcg/mL of IONPs, the content of Fe was 1.5 times higher in glc-IONP-treated cells compared with PVP-IONP-treated cells. After 1h pre-treatment with anti-GLUT1, a reduction of 41% cellular accumulation of glc-IONP was observed. Conversely, the uptake of PVP-IONPs was reduced only by 14% with antibody pretreatment. In conclusion, MVS allowed us to prepare small, homogeneous, super-paramagnetic glc-IONP, which are electively internalized by a tumor line over-expressing GLUT1. Our glc-IONP appear to have many requisites for in vivo use.

  18. Preparation of nickel oxide thin films at different annealing temperature by sol-gel spin coating method

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah, M. A. R., E-mail: ameerridhwan89@gmail.com; Mamat, M. H., E-mail: hafiz-030@yahoo.com; Ismail, A. S., E-mail: kyrin-samaxi@yahoo.com [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Malek, M. F., E-mail: firz-solarzelle@yahoo.com [NANO-SciTech Centre (NST), Institute of Science (IOS), Universiti Teknologi MARA - UiTM, 40450 Shah Alam, Selangor (Malaysia); Alrokayan, Salman A. H., E-mail: dr.salman@alrokayan.com; Khan, Haseeb A., E-mail: khan-haseeb@yahoo.com [Chair of Targeting and Treatment of Cancer Using Nanoparticles, Deanship of Scientific Research, King Saud University (KSU), Riyadh 11451 (Saudi Arabia); Rusop, M., E-mail: rusop@salam.uitm.my [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); NANO-SciTech Centre (NST), Institute of Science (IOS), Universiti Teknologi MARA - UiTM, 40450 Shah Alam, Selangor (Malaysia)

    2016-07-06

    Preparation of NiO thin films at different annealing temperature by sol-gel method was conducted to synthesize the quality of the surface thin films. The effects of annealing temperature on the surface topology were systematically investigated. Our studies confirmed that the surface roughness of the thin films was increased whenever annealing temperature was increase. NiO thin films morphology structure analysis was confirmed by field emission scanning electron microscope. Surface roughness of the thin films was investigated by atomic force microscopy.

  19. Potentiometric Flow Injection Analysis of Bromhexine Hydrochloride and its Pharmaceutical Preparation Using Conventional and Coated Wire Ion-Selective Electrodes

    OpenAIRE

    Nour T. Abdel-Ghani; Issa, Yousry M.; Ahmed, Howayda M.

    2006-01-01

    Bromhexine hydrochloride ion-selective electrodes (conventional type) based on bromhexinium tetraphenyl borate (I) and bromhexinium-phosphotungstate (II) were prepared. The electrodes exhibited mean slopes of calibration graphs of 59.4 mV and 59.8 mV per decade of bromhexine concentration at 25°C for electrode (I) and (II), respectively. Both electrodes could be used within the concentration range 3.16x10-5-1.00x10-2 M bromhexine within the pH range 2.0-4.5. The standard electrodes potentials...

  20. Preparation and microwave absorbing property of Ni–Zn ferrite-coated hollow glass microspheres with polythiophene

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lindong; Chen, Xingliang; Qi, Shuhua, E-mail: qishuhuanwpu@163.com

    2016-11-01

    The composite of hollow glass microspheres (HMG) coated by Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} particles was fabricated via sol–gel method, and then the ternary composite (HMG/Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4}/PT) was synthesized by in situ polymerization. The electrical property, magnetic performance and reflection loss of the composites were measured, and the results suggest that the conductivity and the saturation magnetization (Ms) of HMG/Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4}/PT reach 6.87×10{sup −5} S/cm and 11.627 emu/g, respectively. The ternary composite has good microwave absorbing properties (R{sub min}=−13.79 dB at 10.51 GHz) and the bandwidth less than −10 dB can reach 2.6 GHz (from 9.4 to 12.0 GHz) in X band (8.2–12.4 GHz). The morphology and chemical structure of the samples were measured through scanning electron microscopy (SEM), X-Ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). This paper also analyzes the relationship between the reflection loss of the absorber and its thickness. - Highlights: • This manuscript synthesized HMG/Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4}/PT composites. • The surface morphology, electrical property, magnetic performance and reflection loss of the composites were measured. • This paper also analyzed the relationship between the reflection loss of the absorber and its thickness.

  1. Ethylene glycol assisted preparation of Ti(4+)-modified polydopamine coated magnetic particles with rough surface for capture of phosphorylated proteins.

    Science.gov (United States)

    Ma, Xiangdong; Ding, Chun; Yao, Xin; Jia, Li

    2016-07-27

    The reversible protein phosphorylation is very important in regulating almost all aspects of cell life, while the enrichment of phosphorylated proteins still remains a technical challenge. In this work, polydopamine (PDA) modified magnetic particles with rough surface (rPDA@Fe3O4) were synthesized by introduction of ethylene glycol in aqueous solution. The PDA coating possessing a wealth of catechol hydroxyl groups could serve as an active medium to immobilize titanium ions through the metal-catechol chelation, which makes the fabrication of titanium ions modified rPDA@Fe3O4 particles (Ti(4+)-rPDA@Fe3O4) simple and very convenient. The spherical Ti(4+)-rPDA@Fe3O4 particles have a surface area of 37.7 m(2) g(-1) and superparamagnetism with a saturation magnetization value of 38.4 emu g(-1). The amount of Ti element in the particle was measured to be 3.93%. And the particles demonstrated good water dispersibility. The particles were used as adsorbents for capture of phosphorylated proteins and they demonstrated affinity and specificity for phosphorylated proteins due to the specific binding sites (Ti(4+)). Factors affecting the adsorption of phosphorylated proteins on Ti(4+)-rPDA@Fe3O4 particles were investigated. The adsorption capacity of Ti(4+)-rPDA@Fe3O4 particles for κ-casein was 1105.6 mg g(-1). Furthermore, the particles were successfully applied to isolate phosphorylated proteins in milk samples, which demonstrated that Ti(4+)-rPDA@Fe3O4 particles had potential application in selective separation of phosphorylated proteins. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Synthesis Mechanism of Low-Voltage Praseodymium Oxide Doped Zinc Oxide Varistor Ceramics Prepared Through Modified Citrate Gel Coating

    Directory of Open Access Journals (Sweden)

    Wan Rafizah Wan Abdullah

    2012-04-01

    Full Text Available High demands on low-voltage electronics have increased the need for zinc oxide (ZnO varistors with fast response, highly non-linear current-voltage characteristics and energy absorption capabilities at low breakdown voltage. However, trade-off between breakdown voltage and grain size poses a critical bottle-neck in the production of low-voltage varistors. The present study highlights the synthesis mechanism for obtaining praseodymium oxide (Pr6O11 based ZnO varistor ceramics having breakdown voltages of 2.8 to 13.3 V/mm through employment of direct modified citrate gel coating technique. Precursor powder and its ceramics were examined by means of TG/DTG, FTIR, XRD and FESEM analyses. The electrical properties as a function of Pr6O11 addition were analyzed on the basis of I-V characteristic measurement. The breakdown voltage could be adjusted from 0.01 to 0.06 V per grain boundary by controlling the amount of Pr6O11 from 0.2 to 0.8 mol%, without alteration of the grain size. The non-linearity coefficient, α, varied from 3.0 to 3.5 and the barrier height ranged from 0.56 to 0.64 eV. Breakdown voltage and α lowering with increasing Pr6O11 content were associated to reduction in the barrier height caused by variation in O vacancies at grain boundary.

  3. Poly(glycidyl methacrylate) nanoparticle-coated capillary with oriented antibody immobilization for immunoaffinity in-tube solid phase microextraction: Preparation and characterization.

    Science.gov (United States)

    Ying, Ling-Ling; Ma, Yuan-Chun; Xu, Bei; Wang, Xian-Hua; Dong, Lin-Yi; Wang, Dong-Mei; Liu, Kun; Xu, Liang

    2017-08-04

    A combination between modification with nanoparticles (NP) and oriented antibody immobilization (OAI) on the inner face of capillary was for the first time developed for immunoaffinity in-tube solid-phase microextraction (SPME) to promise high antigen extraction capacity. β2-microglobin (β2MG) and cystatin C (Cys-C) were selected as model antigens. Poly(glycidyl methacrylate) (PGMA) NPs were chemically immobilized onto the capillary by a ring-opening reaction. Antibodies for β2MG and Cys-C were immobilized on the NPs through OAI. Scanning electron micrograph of the OAI capillary clearly showed that the PGMA NPs were coated onto the inner surface of capillary in a dense monolayer. In addition, random antibody immobilized (RAI) capillaries and OAI capillaries without NP were also prepared as controls. The extraction capacities of OAI capillaries were 2.02 and 2.18mgm(-1) for β2MG and Cys-C, and were about 5 and 6 times as many as RAI capillaries and OAI capillaries without NP, respectively. The resultant capillaries were used as in-tube SPME materials to enrich β2MG and Cys-C for particle-enhanced turbidimetric immunoassay. When using 1.0mgL(-1) standard solutions, the recoveries of OAI capillaries, RAI capillaries and OAI capillaries without NP were 103.6% and 96.8%, 48.5% and 31.5%, and 24.2% and 25.7% for β2MG and Cys-C, respectively. Furthermore, the method quantitation limit by OAI capillaries was 5 and 10 times lower than that by RAI capillaries and OAI capillaries without NP, respectively. This result indicated that the NP-coated capillaries with OAI are more suitable for using as immunoaffinity in-tube SPME materials than that with RAI. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Structure and characterization of Sn, Al co-doped zinc oxide thin films prepared by sol–gel dip-coating process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min-I [Institute of Materials Science and Engineering, National Central University, Taiwan (China); Laboratoire de Nanotechnologie et d' Instrumentation Optique, Institut Charles Delaunay, CNRS - UMR STMR 6279, Université de Technologie de Troyes (France); Huang, Mao-Chia [Institute of Materials Science and Engineering, National Central University, Taiwan (China); Legrand, David [Institute of Materials Science and Engineering, National Central University, Taiwan (China); Laboratoire de Nanotechnologie et d' Instrumentation Optique, Institut Charles Delaunay, CNRS - UMR STMR 6279, Université de Technologie de Troyes (France); Lerondel, Gilles [Laboratoire de Nanotechnologie et d' Instrumentation Optique, Institut Charles Delaunay, CNRS - UMR STMR 6279, Université de Technologie de Troyes (France); Lin, Jing-Chie, E-mail: jclin4046@gmail.com [Institute of Materials Science and Engineering, National Central University, Taiwan (China)

    2014-11-03

    Transparent conductive zinc oxide co-doped with tin and aluminum (TAZO) thin films were prepared via sol–gel dip-coating process. Non-toxic ethanol was used in this study instead of 2-methoxyethanol used in conventional work. Dip-coating was repeated several times to obtain relatively thick films consisting of six layers. The films were then annealed at 500 °C for 1 h in air or in vacuum and not subsequently as employed in other studies. The X-ray diffraction patterns indicated that all the samples revealed a single phase of hexagonal ZnO polycrystalline structure with a main peak of (002). The optical band gap and resistivity of the TAZO films were in the ranges of 3.28 to 3.32 eV and 0.52 to 575.25 Ω cm, respectively. The 1.0 at.% Sn, 1.0 at.% Al co-doped ZnO thin film annealed in vacuum was found to have a better photoelectrochemical performance with photocurrent density of about 0.28 mA/cm{sup 2} at a bias of 0.5 V vs. SCE under a 300 W Xe lamp illumination with the intensity of 100 mW/cm{sup 2}. Compared to the same dopant concentration but annealed in air (∼ 0.05 mA/cm{sup 2} bias 0.5 V vs. SCE), the photocurrent density of the film annealed in vacuum was 5 times higher than the film annealed in air. Through electrochemical measurements, we found that the dopant concentration of Sn plays an important role in TAZO that affected photocurrent density, stability of water splitting and anti-corrosion. - Highlights: • Al, Sn co-doped ZnO (TAZO) films was synthesized by sol–gel process. • The parameters of TAZO films were dopant concentration and annealed ambient. • The photoelectrochemical characteristics of TAZO films were investigated.

  5. Coated electroactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Amine, Khalil; Abouimrane, Ali

    2016-08-30

    A process includes suspending an electroactive material in a solvent, suspending or dissolving a carbon precursor in the solvent; and depositing the carbon precursor on the electroactive material to form a carbon-coated electroactive material. Compositions include a graphene-coated electroactive material prepared from a solution phase mixture or suspension of an electroactive material and graphene, graphene oxide, or a mixture thereof.

  6. Palladium-zinc catalysts on mesoporous titania prepared by colloid synthesis. II. Synthesis and characterization of PdZn/TiO2 coating on inner surface of fused silica capillary

    Science.gov (United States)

    Okhlopkova, Lyudmila B.; Kerzhentsev, Michail A.; Tuzikov, Fedor V.; Larichev, Yurii V.; Ismagilov, Zinfer R.

    2012-09-01

    Nanoparticle-doped mesoporous titania coating was synthesized by incorporation of PdZn nanoparticles into TiO2 sol followed by dip coating of the sol on inner surface of fused silica capillary. Monodispersed PdZn bimetallic colloidal particles with average particle diameters of approximately 2 nm have been prepared by an ethylene glycol reduction of ZnCl2 and Pd(CH3COO)2 in the presence of polyvinylpyrrolidone. The textural properties, surface structure, chemical composition, and morphology of the samples were investigated by means of N2 sorption measurements, TEM, and X-ray diffraction. PdZn/TiO2 coating has been further analyzed by quantitative analysis of the SAXS data in combination with the density contrast method, providing direct structural-dispersion information about the active component and support. Calcination conditions suitable for surfactant removal have been optimized to obtain PdZn/TiO2 coatings with required metal particle size and composition. The high dispersion and chemical composition of the nanoparticles embedded in mesoporous titania coating have been retained with no modification after thermal treatment in vacuum at 300 °C. Results suggest how porous structure of the PdZn coating may be fine-tuned to improve the accessibility of the pores to reactants. The control of the pore size in the range of 4.9-6.8 nm of the mesoporous titania was achieved by adding co-surfactants, such as n-butanol.

  7. Preparation and application of crosslinked poly(sodium acrylate)--coated magnetite nanoparticles as corrosion inhibitors for carbon steel alloy.

    Science.gov (United States)

    Atta, Ayman M; El-Mahdy, Gamal A; Al-Lohedan, Hamad A; El-Saeed, Ashraf M

    2015-01-14

    This work presents a new method to prepare poly(sodium acrylate) magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA) as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate) as shell. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM) was used to examine the morphology of the modified poly(sodium acrylate) magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance.

  8. Preparation and Application of Crosslinked Poly(sodium acrylate-Coated Magnetite Nanoparticles as Corrosion Inhibitors for Carbon Steel Alloy

    Directory of Open Access Journals (Sweden)

    Ayman M. Atta

    2015-01-01

    Full Text Available This work presents a new method to prepare poly(sodium acrylate magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate as shell. Fourier transform infrared spectroscopy (FTIR was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM was used to examine the morphology of the modified poly(sodium acrylate magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS. Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance.

  9. SaOS-2 cell response to macro-porous boron-incorporated TiO{sub 2} coating prepared by micro-arc oxidation on titanium

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Qianli [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Elkhooly, Tarek A. [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Department of Ceramics, Inorganic Chemical Industries Division, National Research Centre, Dokki, 12622 Cairo (Egypt); Liu, Xujie [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Zhang, Ranran; Yang, Xing; Shen, Zhijian [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Feng, Qingling, E-mail: biomater@mail.tsinghua.edu.cn [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory of Advanced Materials of Ministry of Education of China, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2016-10-01

    The aims of the present study were to develop boron-incorporated TiO{sub 2} coating (B-TiO{sub 2} coating) through micro-arc oxidation (MAO) and subsequently evaluate the effect of boron incorporation on the in vitro biological performance of the coatings. The physicochemical properties of B-TiO{sub 2} coating and its response to osteoblast like cells (SaOS-2) were investigated compared to the control group without boron (TiO{sub 2} coating). The morphological and X-ray diffraction results showed that both coatings exhibited similar surface topography and phase composition, respectively. However, the incorporation of B led to an enhancement in the surface hydrophilicity of B-TiO{sub 2} coating. The spreading of SaOS-2 cells on B-TiO{sub 2} coating was faster than that on TiO{sub 2} coating. The proliferation rate of SaOS-2 cells cultured on B-TiO{sub 2} decreased after 5 days of culture compared to that on TiO{sub 2} coating. SaOS-2 cells cultured on B-TiO{sub 2} coating exhibited an enhanced alkaline phosphatase (ALP) activity, Collagen I synthesis and in vitro mineralization compared to those on TiO{sub 2} coating. The present findings suggest that B-TiO{sub 2} coating is a promising candidate surface for orthopedic implants. - Highlights: • SaOS-2 cell response to pure TiO{sub 2} and B-TiO{sub 2} coatings was investigated. • Initial cell spreading on B-TiO{sub 2} coating was accelerated compared to that on TiO{sub 2} coating. • Cell proliferation on B-TiO{sub 2} coating was inhibited compared to that on TiO{sub 2} coating. • Cell differentiation on B-TiO{sub 2} coating was enhanced compared to that on TiO{sub 2} coating.

  10. Methods and means for coating paper by film coating

    NARCIS (Netherlands)

    van der Maarel, Marc; Ter Veer, Arend Berend Cornelis; Vrieling-Smit, Annet; Delnoye, Pierre

    2015-01-01

    This invention relates to the field of paper coating, more in particular to means and methods for providing paper with at least one layer of pigment using film coating to obtain a well printable surface. Provided is a method for preparing coated paper comprising the steps of: a) providing a

  11. Modification of Ti6Al4V implant surfaces by biocompatible TiO2/PCL hybrid layers prepared via sol-gel dip coating: Structural characterization, mechanical and corrosion behavior.

    Science.gov (United States)

    Catauro, Michelina; Bollino, Flavia; Giovanardi, Roberto; Veronesi, Paolo

    2017-05-01

    Surface modification of metallic implants is a promising strategy to improve tissue tolerance, osseointegration and corrosion resistance of them. In the present work, bioactive and biocompatible organic-inorganic hybrid coatings were prepared using a sol-gel dip coating route. They consist of an inorganic TiO 2 matrix in which different percentages of poly(ε-caprolactone) (PCL), a biodegradable and biocompatible polymer, were incorporated. The coatings were used to modify the surface of Ti6Al4V substrates in order to improve their wear and corrosion resistance. The chemical structure of the coatings was analyzed by attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy. Coating microstructure, mechanical properties and ability to inhibit the corrosion of the substrates were evaluated as a function of the PCL amount. Scanning electron microscopy (SEM) showed that the polymer allows to obtain crack-free coatings, but when high percentages were added uncoated areas appear. Nano-indentation tests revealed that, as expected, surface hardness and elastic modulus decrease as the percentage of polymeric matrix increases, but scratch testing demonstrated that the coatings are effective in preventing scratching of the underlying metallic substrate, at least for PCL contents up to 20wt%. The electrochemical tests (polarization curves acquired in order to evaluate the corrosion resistance) allowed to asses that the coatings have a significant effect in term of corrosion potential (E corr ) but they do not significantly affect the passivation process that titanium undergoes in contact with the test solution used (modified Dulbecco's phosphate-buffered saline or DPBS). Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Preparation of silane-functionalized silica films via two-step dip coating sol–gel and evaluation of their superhydrophobic properties

    Energy Technology Data Exchange (ETDEWEB)

    Ramezani, Maedeh, E-mail: m.ramezani@merc.ac.ir [Division of Nanotechnology and Advanced Materials, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of); Vaezi, Mohammad Reza [Division of Nanotechnology and Advanced Materials, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of); Kazemzadeh, Asghar [Division of Semiconductors, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of)

    2014-10-30

    Highlights: • Superhydrophobic silica film was prepared by sol–gel process. • The surfaces exhibited superhydrophobicity with water contact angle greater than 150°. • AFM images showed the roughness increases with increasing the percentage of silylation agent. • Before and after modification, the particle size of silica was lower than 50 nm. - Graphical abstract: Schematic illustration of the surface modification of the silica nanoparticle by iso-OTMS on the glass substrate. - Abstract: In this paper, we study the two-step dip coating via a sol–gel process to prepare superhydrophobic silica films on the glass substrate. The water repellency of the silica films was controlled by surface silylation method using isooctyltrimethoxysilane (iso-OTMS) as a surface modifying agent. Silica alcosol was synthesized by keeping the molar ratio of ethyltriethoxysilane (ETES) precursor, ethanol (EtOH) solvent, water (H{sub 2}O) was kept constant at 1:36:6.6 respectively, with 6 M NH{sub 4}OH throughout the experiment and the percentages of hydrophobic agent in hexane bath was varied from 0 to 15 vol.%. The static water contact angle values of the silica films increased from 108° to 160° with an increase in the vol.% of iso-OTMS. At 15 vol%. of iso-OTMS, the silica film shows static water contact angle as high as 160°. The superhydrophobic silica films are thermally stable up to 440 °C and above this temperature, the silica films lose superhydrophobicity. By controlling the primer particle size of SiO{sub 2} about 26 nm, leading to decrease the final size of silica nanoparticles after modification of nanoparticles by isooctyltrimethoxysilane about 42 nm. The films are transparent and have uniform size on the surface. The silica films have been characterized by atomic force microscopy (AFM), fourier transform infrared spectroscopy (FT-IR), transparency, contact angle measurement (CA), Zeta-potential, Thermal stability by TG–DTA analysis.

  13. Correlation between microstructure and optical properties of nano-crystalline TiO{sub 2} thin films prepared by sol-gel dip coating

    Energy Technology Data Exchange (ETDEWEB)

    Mechiakh, R., E-mail: raouf_mechiakh@yahoo.fr [Departement de Medecine, Faculte de Medecine, Universite Hadj Lakhdar, Batna (Algeria); Laboratoire de Photovoltaique de Semi-conducteurs et de Nanostructures, Centre de Recherche des Sciences et Technologies de l' Energie, BP.95, Hammam-Lif 2050 (Tunisia); Laboratoire de Ceramiques, Universite Mentouri Constantine (Algeria); Sedrine, N. Ben; Chtourou, R. [Laboratoire de Photovoltaique de Semi-conducteurs et de Nanostructures, Centre de Recherche des Sciences et Technologies de l' Energie, BP.95, Hammam-Lif 2050 (Tunisia); Bensaha, R. [Laboratoire de Ceramiques, Universite Mentouri Constantine (Algeria)

    2010-11-15

    Titanium dioxide thin films have been prepared from tetrabutyl-orthotitanate solution and methanol as a solvent by sol-gel dip coating technique. TiO{sub 2} thin films prepared using a sol-gel process have been analyzed for different annealing temperatures. Structural properties in terms of crystal structure were investigated by Raman spectroscopy. The surface morphology and composition of the films were investigated by atomic force microscopy (AFM). The optical transmittance and reflectance spectra of TiO{sub 2} thin films deposited on silicon substrate were also determined. Spectroscopic ellipsometry study was used to determine the annealing temperature effect on the optical properties and the optical gap of the TiO{sub 2} thin films. The results show that the TiO{sub 2} thin films crystallize in anatase phase between 400 and 800 deg. C, and into the anatase-rutile phase at 1000 deg. C, and further into the rutile phase at 1200 deg. C. We have found that the films consist of titanium dioxide nano-crystals. The AFM surface morphology results indicate that the particle size increases from 5 to 41 nm by increasing the annealing temperature. The TiO{sub 2} thin films have high transparency in the visible range. For annealing temperatures between 1000 and 1400 deg. C, the transmittance of the films was reduced significantly in the wavelength range of 300-800 nm due to the change of crystallite phase and composition in the films. We have demonstrated as well the decrease of the optical band gap with the increase of the annealing temperature.

  14. Preparation and characterization of chitosan-Polyethylene glycol-polyvinylpyrrolidone-coated superparamagnetic iron oxide nanoparticles as carrier system: Drug loading and in vitro drug release study.

    Science.gov (United States)

    Prabha, G; Raj, V

    2016-05-01

    In the present research work, the anticancer drug "curcumin" is loaded with Chitosan (CS)-polyethylene glycol (PEG)-polyvinylpyrrolidone (PVP) (CS-PEG-PVP) polymer nanocomposites coated with superparamagnetic iron oxide (Fe3 O4 ) nanoparticles. The system can be used for targeted and controlled drug delivery of anticancer drugs with reduced side effects and greater efficiency. The prepared nanoparticles were characterized by Fourier transmission infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Curcumin drug-loaded Fe3 O4 -CS, Fe3 O4 -CS- PEG and Fe3 O4 -CS-PEG-PVP nanoparticles exhibited the mean particle size in the range of 183 - 390 nm with a zeta potential value of 26 mV-41 mV as measured using Malvern Zetasizer. The encapsulation efficiency, loading capacity and in-vitro drug release behaviour of curcumin drug-loaded Fe3 O4 -CS, Fe3 O4 -CS-PEG, and Fe3 O4 -CS-PEG-PVP nanoparticles were studied using UV spectrophotometer. Besides, the cytotoxicity of the prepared nanoparticles using MTT assay was also studied. The curcumin drug release was examined at different pH medium (4.5 and 7.4) and temperature (37°C and 45°C), and it was proved that the drug release depends upon the pH medium and temperature in addition to the nature of matrix. © 2016 Wiley Periodicals, Inc.

  15. Effect of Illumination on the Photovoltaic Parameters of Al/p-Si Diode with an Organic Interlayer Prepared by Spin Coating Method

    Directory of Open Access Journals (Sweden)

    Arife GENCER IMER

    2016-12-01

    Full Text Available In this study, the photovoltaic device application of bromothymol blue (BTB as an organic interlayer has been reported. After Al back contact fabrication on the surface of the chemically cleaned substrate by thermal evaporation method, the organic interlayer has been grown on p-Si substrate via spin coating technique. Al top contacts have been formed on this organic thin film to finalize the device constructions. The different illumination intensities were exposed to the prepared sample for the enhancement in the photovoltaic properties of device. The fundamental photovoltaic parameters such as open circuit voltage (Voc, short circuit current (Isc and output power (P were determined for the device under different illuminations. The photocurrent and the photo voltage have been increased with the increasing in illumination intensity. The dependence of the capacitance on the voltage at high and low frequency has been also reported for the studied device. Consequently, it has been confirmed that the illumination intensity has an important influence on the photovoltaic parameters of the device.

  16. Preparation of polydopamine-coated graphene oxide/Fe3O4 imprinted nanoparticles for selective removal of fluoroquinolone antibiotics in water.

    Science.gov (United States)

    Tan, Feng; Liu, Min; Ren, Suyu

    2017-07-18

    Antibiotics in water have recently caused increasing concerns for public health and ecological environments. In this work, we demonstrated polydopamine-coated graphene oxide/Fe3O4 (PDA@GO/Fe3O4) imprinted nanoparticles coupled with magnetic separation for fast and selective removal of fluoroquinolone antibiotics in water. The nanoparticles were prepared by the self-polymerization of dopamine using sarafloxacin as a template. The imprinted PDA film of 10~20 nm uniformly covered the surface of GO/Fe3O4 providing selective binding sites. The nanoparticles showed rapid binding and a large capacity (70.9 mg/g). The adsorption data fitted well the Langmuir and pseudo-second order kinetic equations. The nanoparticles could be easily separated by a magnet following the adsorption and then regenerated by simple washing for repetitive adsorptions. The nanoparticles were successfully used for the removal of fluoroquinolone antibiotics in seawater, with removal efficiencies of more than 95%. The proposed strategy has potentials for efficient removal of antibiotics in environmental water.

  17. Preparation of silane-functionalized silica films via two-step dip coating sol-gel and evaluation of their superhydrophobic properties

    Science.gov (United States)

    Ramezani, Maedeh; Vaezi, Mohammad Reza; Kazemzadeh, Asghar

    2014-10-01

    In this paper, we study the two-step dip coating via a sol-gel process to prepare superhydrophobic silica films on the glass substrate. The water repellency of the silica films was controlled by surface silylation method using isooctyltrimethoxysilane (iso-OTMS) as a surface modifying agent. Silica alcosol was synthesized by keeping the molar ratio of ethyltriethoxysilane (ETES) precursor, ethanol (EtOH) solvent, water (H2O) was kept constant at 1:36:6.6 respectively, with 6 M NH4OH throughout the experiment and the percentages of hydrophobic agent in hexane bath was varied from 0 to 15 vol.%. The static water contact angle values of the silica films increased from 108° to 160° with an increase in the vol.% of iso-OTMS. At 15 vol%. of iso-OTMS, the silica film shows static water contact angle as high as 160°. The superhydrophobic silica films are thermally stable up to 440 °C and above this temperature, the silica films lose superhydrophobicity. By controlling the primer particle size of SiO2 about 26 nm, leading to decrease the final size of silica nanoparticles after modification of nanoparticles by isooctyltrimethoxysilane about 42 nm. The films are transparent and have uniform size on the surface. The silica films have been characterized by atomic force microscopy (AFM), fourier transform infrared spectroscopy (FT-IR), transparency, contact angle measurement (CA), Zeta-potential, Thermal stability by TG-DTA analysis.

  18. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, T.

    1997-02-18

    Zinc phosphate conversion co