WorldWideScience

Sample records for prepared nylon-6 solution

  1. Preparation of a novel KCC-1/nylon 6 nanocomposite via electrospinning technique

    Energy Technology Data Exchange (ETDEWEB)

    Aghakhani, Ali [Material and Energy Research Center, Department of Semiconductors (Iran, Islamic Republic of); Kazemi, Ensiyeh; Kazemzad, Mahmood, E-mail: m-kazemzad@merc.ac.ir [Material and Energy Research Center, Department of Energy (Iran, Islamic Republic of)

    2015-10-15

    In this research, a novel nanofibrous composite of KCC-1/nylon 6 was prepared using electrospinning techniques. First, fibrous silica nanospheres (KCC-1) were synthesized via conventional polycondensation method with a new solvent system. The scanning electron microscopy (SEM) images showed a spongy spherical morphology with a uniform distribution of particle sizes and an average diameter of around 305 nm. Synthesized KCC-1 nanospheres are considered as mesoporous materials due to their high BET specific surface area of 576 m{sup 2} g{sup −1} and BJH average pore diameter of 3.28 nm. The KCC-1/nylon 6 composite was fabricated by preparing a dispersion of nanosilica (10–50 % w/w) in a solution of nylon 6 (15 % w/v) in formic acid. Upon applying a high voltage, the nonwoven electrospun KCC-1/nylon 6 composite nanofibers were obtained. The KCC-1 nanospheres were arranged in line along the nylon 6 fibers like rosary beads wrapped in the polymer. Based on the SEM images, we obtained a well-distributed nanocomposite even at higher silica content. The prepared KCC-1/nylon 6 composite showed 29–55 % higher BET specific surface area compared with pure nylon 6 nanofibers which makes it a good candidate to be used as a sorbent material for environmental or drug delivery applications.

  2. Preparation and Characterization of Nylon 6/Silver Nanocomposite Fibers for Permanent Antibacterial Effect

    Directory of Open Access Journals (Sweden)

    Laleh Maleknia

    2015-03-01

    Full Text Available The nylon 6/silver nano composite fibers were prepared for the attainment of permanent antibacterial activity to common synthetic textile. The fibers prepared by melt spinning and nylon 6/ Silver nanocomposite were prepared by a modular twin screw extruder.. The antibacterial activities of nano silver in fibers were calculated by percent reduction of two kinds of bacteria staphylococcus aurous and klebsiela peneumoniae. Scanning electron microscopy (SEM was carried out to observe particle distribution on the nanocomposite fibers. All the nanocomposite fibers were characterized by instron machine.

  3. Blends of zein and nylon-6

    Science.gov (United States)

    Blends of zein and nylon-6(55k)were used to produce solution cast films and electrospun fibers. Zein was blended with nylon-6 in formic acid solution. When the amount of nylon-6 was 8% or less a compatible blend formed. The blend was determined to be compatible based on physical property measurement...

  4. Preparation of Surface Adsorbed and Impregnated Multi-walled Carbon Nanotube/Nylon-6 Nanofiber Composites and Investigation of their Gas Sensing Ability.

    Science.gov (United States)

    Lala, Neeta L; Thavasi, Velmurugan; Ramakrishna, Seeram

    2009-01-01

    We have prepared electrospun Nylon-6 nanofibers via electrospinning, and adsorbed multi-walled carbon nanotubes (MWCNTs) onto the surface of Nylon-6 fibers using Triton(®) X-100 to form a MWCNTs/Nylon-6 nanofiber composite. The dispersed MWCNTs have been found to be stable in hexafluoroisopropanol for several months without precipitation. A MWCNTs/Nylon-6 nanofiber composite based chemical sensor has demonstrated its responsiveness towards a wide range of solvent vapours at room temperature and only mg quantities of MWCNTs were expended. The large surface area and porous nature of the electrospun Nylon-6/MWCNT nanofibers facilitates greater analyte permeability. The experimental analysis has indicated that the dipole moment, functional group and vapour pressure of the analytes determine the magnitude of the responsiveness.

  5. Preparation of Surface Adsorbed and Impregnated Multi-walled Carbon Nanotube/Nylon-6 Nanofiber Composites and Investigation of their Gas Sensing Ability

    Directory of Open Access Journals (Sweden)

    Velmurugan Thavasi

    2009-01-01

    Full Text Available We have prepared electrospun Nylon-6 nanofibers via electrospinning, and adsorbed multi-walled carbon nanotubes (MWCNTs onto the surface of Nylon-6 fibers using Triton® X-100 to form a MWCNTs/Nylon-6 nanofiber composite. The dispersed MWCNTs have been found to be stable in hexafluoroisopropanol for several months without precipitation. A MWCNTs/Nylon-6 nanofiber composite based chemical sensor has demonstrated its responsiveness towards a wide range of solvent vapours at room temperature and only mg quantities of MWCNTs were expended. The large surface area and porous nature of the electrospun Nylon-6/MWCNT nanofibers facilitates greater analyte permeability. The experimental analysis has indicated that the dipole moment, functional group and vapour pressure of the analytes determine the magnitude of the responsiveness.

  6. A Composite of Electrospun Nylon-6 Nanofibers and in-situ Polymerized Polypyrrole as an NH3 Gas Sensor

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results Electrospinning provides a simple and versatile method for preparing nanofibers with different morphology, such as porous fibers and nanotubes. It has been widely used for preparing nanomaterials with unique properties and potential applications in medicine, catalyst, photonics and sensors[1, 2]. In this study, uniform Nylon-6 nanofibers with diameter of ≈300 nm by electrospun from formic acid solution containing 15%wt Nylon-6. Polypyrrole (PPy) was then deposited on the nanofibers by in-situ ...

  7. Electrospun fiber and cast films produced using zein blends with nylon-6

    Science.gov (United States)

    Blends of zein and nylon-6 (55k) were used to produce electrospun fibers and solution cast films. Zein was blended with nylon-6 in formic acid solution. When the amount of nylon-6 was 8% or less a compatible blend formed. The blend was determined to be compatible based on physical property measureme...

  8. Electrospun MgO/Nylon 6 Hybrid Nanofib ers for Protective Clothing

    Institute of Scientific and Technical Information of China (English)

    Nattanmai Raman Dhineshbabu; Gopalu Karunakaran; Rangaraj Suriyaprabha; Palanisamy Manivasakan; Venkatachalam Rajendran

    2014-01-01

    Magnesia (MgO) nanoparticles were produced from magnesite ore (MgCO3) using ball mill. The crystalline size, morphology and specific SSA were characterized by X-ray diffraction analysis, transmission electron microscopy and Brunauer-Emmett-Teller method, respectively. MgO nanoparticle-incorporated nylon 6 solutions were electrospun to produce nanofiber mats. Surface morphology and internal structure of the pre-pared hybrid nanofiber mats were examined by scanning electron microscopy and high-resolution transmission electron microscopy, respectively. The fire retardancy and antibacterial activity (Staphylococcus aureus and Escherichia coli) of coated fabrics made from MgO/nylon 6 hybrid nanofiber are better than those from nylon 6 nanofiber.

  9. Photocatalytic and antibacterial properties of a TiO2/nylon-6 electrospun nanocomposite mat containing silver nanoparticles.

    Science.gov (United States)

    Pant, Hem Raj; Pandeya, Dipendra Raj; Nam, Ki Taek; Baek, Woo-Il; Hong, Seong Tshool; Kim, Hak Yong

    2011-05-15

    Silver-impregnated TiO(2)/nylon-6 nanocomposite mats exhibit excellent characteristics as a filter media with good photocatalytic and antibacterial properties and durability for repeated use. Silver nanoparticles (NPs) were successfully embedded in electrospun TiO(2)/nylon-6 composite nanofibers through the photocatalytic reduction of silver nitrate solution under UV-light irradiation. TiO(2) NPs present in nylon-6 solution were able to cause the formation of a high aspect ratio spider-wave-like structure during electrospinning and facilitated the UV photoreduction of AgNO(3) to Ag. TEM images, UV-visible and XRD spectra confirmed that monodisperse Ag NPs (approximately 4 nm in size) were deposited selectively upon the TiO(2) NPs of the prepared nanocomposite mat. The antibacterial property of a TiO(2)/nylon-6 composite mat loaded with Ag NPs was tested against Escherichia coli, and the photoactive property was tested against methylene blue. All of the results showed that TiO(2)/nylon-6 nanocomposite mats loaded with Ag NPs are more effective than composite mats without Ag NPs. The prepared material has potential as an economically friendly photocatalyst and water filter media because it allows the NPs to be reused.

  10. Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning– electrospraying hybrid process for use in protective applications

    Science.gov (United States)

    ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacter...

  11. Effect of random/aligned nylon-6/MWCNT fibers on dental resin composite reinforcement.

    Science.gov (United States)

    Borges, Alexandre L S; Münchow, Eliseu A; de Oliveira Souza, Ana Carolina; Yoshida, Takamitsu; Vallittu, Pekka K; Bottino, Marco C

    2015-08-01

    The aims of this study were (1) to synthesize and characterize random and aligned nanocomposite fibers of multi-walled carbon nanotubes (MWCNT)/nylon-6 and (2) to determine their reinforcing effects on the flexural strength of a dental resin composite. Nylon-6 was dissolved in hexafluoropropanol (10 wt%), followed by the addition of MWCNT (hereafter referred to as nanotubes) at two distinct concentrations (i.e., 0.5 or 1.5 wt%). Neat nylon-6 fibers (without nanotubes) were also prepared. The solutions were electrospun using parameters under low- (120 rpm) or high-speed (6000 rpm) mandrel rotation to collect random and aligned fibers, respectively. The processed fiber mats were characterized by scanning (SEM) and transmission (TEM) electron microscopies, as well as by uni-axial tensile testing. To determine the reinforcing effects on the flexural strength of a dental resin composite, bar-shaped (20×2×2 mm(3)) resin composite specimens were prepared by first placing one increment of the composite, followed by one strip of the mat, and one last increment of composite. Non-reinforced composite specimens were used as the control. The specimens were then evaluated using flexural strength testing. SEM was done on the fractured surfaces. The data were analyzed using ANOVA and the Tukey׳s test (α=5%). Nanotubes were successfully incorporated into the nylon-6 fibers. Aligned and random fibers were obtained using high- and low-speed electrospinning, respectively, where the former were significantly (presin composite tested was significantly reinforced when combined with nylon-6 fibrous mats composed of aligned fibers (with or without nanotubes) or random fibers incorporated with nanotubes at 0.5 wt%. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. 阴离子原位聚合橡胶改性尼龙6的形态结构%Morphological Structure of Rubber-Modiifed Nylon-6 Prepared by Anionic In-situ Polymerization

    Institute of Scientific and Technical Information of China (English)

    赵洪凯; 王洪里

    2016-01-01

    The rubber modifier was prepared by grafting on hydroxyl-terminated liquid polybutadiene rubber(HTPB) with HDI urea diketone and blocking the isocyanate group with caprolactam,and the liquid rubber-modified nylon-6 resin was prepared by the anionic polymerization. The infrared analysis shows that HDI urea diketone is successfully blocked by caprolactam after grafting on hydroxyl of HTPB,and then,the rubber-modified nylon copolymer is generated by the anionic polymerization. After the impact section analysis,when the rubber content is higher than 15%,the modified nylon resin shows the obvious ductile fracture,the toluene etching after the brittle failure shows that the rubber which does not participate in the polymerization is increased when the content of the rubber activator is increased,which causes that the micro-phase size of the rubber is increased and the uniformity is reduced. At 180℃,the rubber-modified nylon 6 resin generated by the polymerization showsαcrystal form,and the addition of the rubber does not changed the crystal form of the nylon 6; after the resin is molten and subjected to the cold crystallization rapidly, the crystal form of nylon 6 is mainly metastableγcrystal form,and as the rubber content is increased,αcrystal form is obviously enhanced,which shows that the existence of the rubber phase is beneficial to form the stableαcrystal form.%采用HDI脲二酮接枝端羟基聚丁二烯液体橡胶(HTPB),再用己内酰胺封端异氰酸酯基团,制得橡胶改性剂,通过阴离子聚合制得液体橡胶改性尼龙(PA)6树脂。分析表明,HDI脲二酮接枝到HTPB的羟基上后被己内酰胺成功封端,进而阴离子聚合生成橡胶改性PA6共聚物。冲击断面分析,当橡胶质量分数高于15%以后,改性PA6树脂表现出明显的韧性断裂,脆断后甲苯刻蚀表明,随着橡胶活化剂含量增加,未参与聚合橡胶含量增加,导致橡胶微相尺寸变大且均匀性下降。在180℃

  13. Polyurethane Grafted Attapulgite as Novel Fillers for Nylon 6 Nanocomposites

    Institute of Scientific and Technical Information of China (English)

    SHI Jianshe; YANG Xujie; HAN Qiaofeng; WANG Xin; LU Lude

    2011-01-01

    Attapulgite fibers were modified by polyurethane,forming polyurethane grafted attapulgite (AT-PU),which was confirmed by Fourier transform infrared spectroscopy(FTIR),X-ray diffraction (XRD)and X-ray photoelectron spectroscopy(XPS).Nylon 6/AT-PU nanocomposites of different modified attapulgite loadings were prepared by melt blending in a twin screw extruder.Scanning electron microscopy (SEM)observation on the fracture surfaces of the nanocomposites showed not only a uniform dispersion of AT-PU but also a strong interfacial adhesion with the matrix.Differential scanning calorimeter(DSC)and Thermogravimetric analyzer(TGA)were used to illustrate the influence of AT-PU particles on the thermal properties of the nylon 6/AT-PU nanocomposites.The results indicated that the addition of attapulgite probably induced the heterogeneous nucleation and was favorable for the formation of γ-crystalline form,and that the higher thermal stability was obtained for the composites.

  14. MODIFICATION OF NYLON-6 WITH POLYORGANOSILOXANE

    Institute of Scientific and Technical Information of China (English)

    YUAN Qiang; LIU Guomin; LI Guangliang

    1990-01-01

    Nylon-6 has been modified by polyorganosiloxane. It was realized by radical addition of caprolactam to the vinyl group of silicone and anionic polymerization of the monomer in the presence of the silicone macromer. The mechanical properties of the modified plastics are not far from that of the unmodified one whereas its frictional properties are significantly improved.

  15. THE EFFECT OF BLENDING SEQUENCE ON PHASE MORPHOLOGY OF NYLON 6/ABS/SMA BLENDS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The preparation process-dependent phase morphology of blends composed of nylon 6 and acryionitrile-butadienestyrene(ABS)over a composition range of 30-70 wt% using a styrene-maleic anhydride(SMA)copolymer as the compatibilizing agent with a constant content(5phr)was investigated.The results of the scanning electron microscope (SEM)observation revealed that compared with the binary blends of nylon 6 and ABS,the existence of SMA caused a composition shift of phase inversion to a higher weight fraction of nylon 6 when ABS was blended with the preblended nylon 6/SMA blend,while the co-continuous structures could be observed over a considerably narrower composition range when nylon 6 was blended with the pre-blended ABS/SMA blend.An examination through dynamic mechanical analysis (DMA)tests confirmed the results obtained with SEM.It is found that near the phase inversion region a remarkable change in the dynamic storage modulus(G')and the loss tangent(tanδ)appears.Moreover,the influence of blending sequence on the size of dispersed particles has been probed for uncompatibilized and compatibilized blends of nylon 6 and ABS over a wide range of compositions below or beyond the phase inversion points.For the blends of ABS dispersed in a nylon 6 matrix,little discernible effects of blending sequence on particle size could be observed.Furthermore,there exists a significant difference in morphologies of the blends prepared by nylon 6 particles dispersing in a ABS matrix in cases of different blending sequences used.Some possible factors responsible for the above asymmetric behaviors have been proposed.

  16. Atrazine adsorption removal with nylon6/polypyrrole core-shell nanofibers mat: possible mechanism and characteristics

    Science.gov (United States)

    Yang, Bi-Yi; Cao, Yang; Qi, Fei-Fei; Li, Xiao-Qing; Xu, Qian

    2015-05-01

    A functionalized nylon6/polypyrrole core-shell nanofibers mat (PA6/PPy NFM) was prepared via situ polymerization on nylon6 electrospun nanofibers mat (PA6 NFM) template and used as an adsorbent to remove atrazine from aqueous solutions. The core-shell structure of PA6/PPy NFM can be clearly proved under scanning electron microscope (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The effects of initial solution pH and ionic strength, as well as the comparison of the adsorption capacity of functionalized (PA6/PPy NFM) and non-functionalized (PA6 NFM) adsorbent, were examined to reveal the possible adsorption mechanism. The results indicated that π-π interaction and electrostatic interaction should play a key role in the adsorption process. The kinetics and thermodynamics studies also further elucidated the detailed adsorption characteristics of atrazine removal by PA6/PPy NFM. The adsorption of atrazine could be well described by the pseudo-second-order equation. The adsorption equilibrium data was well fitted with the Freundlich isotherm model with a maximum adsorption capacity value of 14.8 mg/g. In addition, the increase of adsorption rate caused by a temperature increase could be felicitously explained by the endothermic reaction. The desorption results showed that the adsorption capacity remained almost unchanged after six adsorption/desorption cycles. These results suggest that PA6/PPy NFM could be employed as an efficient adsorbent for removing atrazine from contaminated water sources.

  17. Preparação de argilas organofílicas e desenvolvimento de nanocompósitos com matrizes poliméricas de polietileno e nylon6. Parte 1: comportamento mecânico Preparation of organophilic clays and development of nanocomposites with polyethylene and nylon6 polymer matrices. Part 1: mechanical properties

    Directory of Open Access Journals (Sweden)

    Edcleide M. Araújo

    2006-03-01

    Full Text Available Argilas bentoníticas provenientes do Município de Boa Vista/PB foram utilizadas para a produção de argilas organofílicas. As argilas organofílicas foram obtidas a partir da síntese com quatro tipos de sais quaternários de amônio: cloreto de alquil dimetil benzil amônio (Dodigen, cloreto de estearil dimetil amônio (Praepagen, cloreto de cetil trimetil amônio (Genamin e brometo de cetil trimetil amônio (Brometo. As argilas tratadas com os sais e a não tratada foram caracterizadas por difração de raios X (DRX e espectroscopia de infravermelho por transformada de Fourier (FTIR. Em seguida, as argilas foram misturadas com matrizes poliméricas do tipo polietileno (PE e nylon6 (PA6 por meio de técnicas convencionais de processamento. As misturas foram caracterizadas por DRX, microscopia eletrônica de varredura (MEV e propriedades mecânicas. Os resultados obtidos por FTIR mostraram a presença dos grupos característicos dos sais na argila e o DRX confirmou a intercalação dos mesmos entre as camadas da argila. As propriedades mecânicas das misturas mostraram um aumento na rigidez em relação aos polímeros puros.Bentonite clays from Boa Vista/PB were used to obtain organophilic clays. Organophilic clays were obtained with four types of quaternary salts of ammonium: asalkyldimethylbenzylammonium chloride (Dodigen, esthearildimethylammonium chloride (Praepagen, cethyltrimethylammonium chloride (Genamin and cethyltrimethylammonium bromide (Bromide. The treated clays with salts and untreated clays were characterized by X-ray diffraction (XRD and Fourier transformed infrared spectroscopy (FTIR. Then, the clays were incorporated into polyethylene (PE and Nylon6 (PA6 polymer matrices using conventional processing techniques. The mixtures were characterized by XRD, scanning electron microscopy (SEM and mechanical properties. The results obtained by FTIR showed the presence of specific groups of the salts in the clay, while their

  18. Electrospun nylon-6 spider-net like nanofiber mat containing TiO(2) nanoparticles: a multifunctional nanocomposite textile material.

    Science.gov (United States)

    Pant, Hem Raj; Bajgai, Madhab Prasad; Nam, Ki Taek; Seo, Yun A; Pandeya, Dipendra Raj; Hong, Seong Tshool; Kim, Hak Yong

    2011-01-15

    In this study, electrospun nylon-6 spider-net like nanofiber mats containing TiO(2) nanoparticles (TiO(2) NPs) were successfully prepared. The nanofiber mats containing TiO(2) NPs were characterized by SEM, FE-SEM, TEM, XRD, TGA and EDX analyses. The results revealed that fibers in two distinct sizes (nano and subnano scale) were obtained with the addition of a small amount of TiO(2) NPs. In low TiO(2) content nanocomposite mats, these nanofiber weaves were found uniformly loaded with TiO(2) NPs on their wall. The presence of a small amount of TiO(2) NPs in nylon-6 solution was found to improve the hydrophilicity (antifouling effect), mechanical strength, antimicrobial and UV protecting ability of electrospun mats. The resultant nylon-6/TiO(2) antimicrobial spider-net like composite mat with antifouling effect may be a potential candidate for future water filter applications, and its improved mechanical strength and UV blocking ability will also make it a potential candidate for protective clothing.

  19. Mechanical and Gas Barrier Properties of Nylon 6/Clay Nanocomposite Blown Films

    Directory of Open Access Journals (Sweden)

    Anongnat Somwangthanaroj

    2012-04-01

    Full Text Available Nylon 6/clay nanocomposite films were prepared by melt mixing nylon 6 with organoclay using a twin screw extruder attached to a blown film die. The type of surfactant used in the pretreatment of organoclay was expected to affect the degree of clay dispersion, which would in turn affect the degree of crystallinity, crystalline phase and bulk properties of the polymer composite. Two different surfactants used to treat the surface of montmorillonite clay were trimethyl tallow quaternary ammonium chloride (M3T, a single-chain surfactant and dimethyl bis (hydrogenated-tallow ammonium chloride (M2(HT2, a double-chain surfactant. The addition of the resulting organoclay into nylon 6 was found to enhance the formation of γ-phase and increase the degree of crystallinity and crystallization temperature of the nylon 6. In fact nanocomposite films containing the single-chain surfactant showed a higher degree of clay dispersion in nylon 6 matrix, up to 148% higher stiffness and up to 100% lower oxygen permeability than those films containing the corresponding double-chain surfactant at the same inorganic loadings investigated. As expected, the nanocomposite films exhibited 58% higher stiffness in the machine direction than the transverse direction.

  20. The influence of ions on water transport in nylon 6 films

    NARCIS (Netherlands)

    Reuvers, N.J.W.; Huinink, H.P.; Fischer, H.R.; Adan, O.C.G.

    2013-01-01

    Nylon 6 films are directly exposed to saline solutions containing mono-valent ions and the water uptake is measured with magnetic resonance imaging (MRI). Both the amount of water uptake and the rate of water uptake are studied. First, the films are exposed to solutions with different concentrations

  1. Nanospider technology for controlling of pseudomonas cichorii and dickeya dadantii by electrospun nanofibers of nylon-6/chitosan blends

    Directory of Open Access Journals (Sweden)

    Abdel-Megeed Ahmed

    2014-01-01

    Full Text Available This is the first report on the use of electrospun nanofibers which could be of considerable interest to the development of new antibacterial compounds against two species of bacteria: Pseudomonas cichorii causing bacterial leaf spot (bacterial midrib rot and Dickeya dadantii (Erwinia chrysanthemi causing bacterial bligh. Electrospun nylon-6/chitosan (nylon-6/Ch nanofibers were obtained using formic acid as a single solvent. Surface modification of electrospun nylon-6/chitosan nanofibers was performed by soaking the mat in an aqueous solution of glycidyltrimethylammonium chloride (GTMAC at room temperature overnight to give nylon-6/N-[(2-hydroxy-3-trimethyl ammoniumpropyl] chitosan chloride (nylon-6/HTCC. The morphological, structural and thermal properties of the nylon-6/chitosan nanofibers were studied by field-emission scanning electron microscopy (FE-SEM, X-ray diffraction (XRD, Fourier transform-infrared (FT-IR spectroscopy, and thermogravimetric analysis (TGA. Biological screening demonstrated that Nylon-6/HTCC mat exhibited high potential antibacterial activity on protein synthesis of bacteria Pseudomonas cichorii and Dickeya dadantii. Bacteria examined using SEM were totally deformed and exhibited symptoms of severe destruction.

  2. Solution preparation

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, M.G.

    1982-01-01

    Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results.

  3. Crystallization and melting behavior of multi-walled carbon nanotube-reinforced nylon-6 composites

    NARCIS (Netherlands)

    Phang, In Yee; Ma, Jianhua; Shen, Lu; Liu, Tianxi; Zhang, Wei-De

    2006-01-01

    The crystallization and melting behavior of neat nylon-6 (PA6) and multi-walled carbon nanotubes (MWNTs)/PA6 composites prepared by simple melt-compounding was comparatively studied. Differential scanning calorimetry (DSC) results show two crystallization exotherms (TCC, 1 and TCC, 2) for PA6/MWNTs

  4. Crystallization and melting behavior of multi-walled carbon nanotube-reinforced nylon-6 composites

    NARCIS (Netherlands)

    Phang, In Yee; Ma, Jianhua; Shen, Lu; Liu, Tianxi; Zhang, Wei-De

    2006-01-01

    The crystallization and melting behavior of neat nylon-6 (PA6) and multi-walled carbon nanotubes (MWNTs)/PA6 composites prepared by simple melt-compounding was comparatively studied. Differential scanning calorimetry (DSC) results show two crystallization exotherms (TCC, 1 and TCC, 2) for PA6/MWNTs

  5. Synergistic effect of nanoclay and EPR-g-MA on the properties of nylon6/EPR blends.

    Science.gov (United States)

    Mallick, Sumana; Das, Tanya; Das, C K; Khatua, B B

    2009-05-01

    The effect of EPR-g-MA, nanoclay and a combination of the two on phase morphology and properties of (70/30 w/w) nylon6/EPR blends prepared by melt processing technique has been studied. We found that the number average domain diameter (D(n)) of the dispersed EPR phase in the blend decreased in presence of EPR-g-MA, and clay. This observation indicated that nanoclay could be used as an effective compatibilizer in nylon6/EPR blend. X-ray diffraction study and TEM analysis of the blend/clay nanocomposites revealed the delaminated clay morphology and preferential location of the exfoliated clay platelets in nylon6 phase. Thus, selective dispersion of the clay platelets with delaminated morphology in the matrix phase acted as the barrier and thereby prevented the coalescence of dispersed EPR domains during melt processing. However, addition of nanoclay in the blend did not improve the impact property of the blend. Interestingly, the impact strength of the nylon6/EPR/EPR-g-MA/clay blend was much higher than the nylon6/EPR/EPR-g-MA and nylon6/EPR/clay blends at certain compositions with comparable D(n) values. This could be explained by assuming the presence of delaminated clay platelets at the interface, which were stiffer than the polymers. Hence, the bending energy of the interfaces was high.

  6. Supersonically blown nylon-6 nanofibers entangled with graphene flakes for water purification

    Science.gov (United States)

    Lee, Jong-Gun; Kim, Do-Yeon; Mali, Mukund G.; Al-Deyab, Salem S.; Swihart, Mark T.; Yoon, Sam S.

    2015-11-01

    Water purification membranes, capable of purifying a few to tens of milliliters of aqueous methylene blue solution in a minute, were produced by supersonically blowing graphene flakes with a nylon-6 polymeric solution. The solution-blown nylon-6 nanofibers became entangled with graphene flakes thereby locking the graphene flakes within the frame of the bendable two-dimensional film structure. This method, which yielded a 5 × 7 cm2-sized membrane in less than 10 seconds, is commercially viable owing to fast fabrication and scalability. We show that our water purification device allows a flow rate range of 0.3-4 L h-1 with a membrane area of just 5 cm2, under a pressure difference of 0.5-3.5 bar. If the membrane were scaled up to 0.5 m2, it could provide 300-4000 L h-1 flow rate, an ample supply for home use.Water purification membranes, capable of purifying a few to tens of milliliters of aqueous methylene blue solution in a minute, were produced by supersonically blowing graphene flakes with a nylon-6 polymeric solution. The solution-blown nylon-6 nanofibers became entangled with graphene flakes thereby locking the graphene flakes within the frame of the bendable two-dimensional film structure. This method, which yielded a 5 × 7 cm2-sized membrane in less than 10 seconds, is commercially viable owing to fast fabrication and scalability. We show that our water purification device allows a flow rate range of 0.3-4 L h-1 with a membrane area of just 5 cm2, under a pressure difference of 0.5-3.5 bar. If the membrane were scaled up to 0.5 m2, it could provide 300-4000 L h-1 flow rate, an ample supply for home use. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06549f

  7. Reinforcement of nylon 6,6/nylon 6,6 grafted nanodiamond composites by in situ reactive extrusion

    Science.gov (United States)

    Choi, Eun-Yeob; Kim, Kiho; Kim, Chang-Keun; Kang, Eunah

    2016-01-01

    Nanodiamond (ND), an emerging new carbon material, was exploited to reinforce nylon 6,6 (PA66) polymer composites. Surface modified nanodiamonds with acyl chloride end groups were employed to chemically graft into PA66, enhancing the interfacial adhesion and thus the mechanical properties. The ND grafted PA66 (PA66-g-ND) reinforced PA66 composite prepared by in situ reactive extrusion exhibited increased tensile strength and modulus. The tensile strength and modulus of PA66/3 wt.% PA66-g-ND composites were enhanced by 11.6 and 20.8%, respectively when compared to those of the bare PA66 matrix. Even the PA66/pristine ND composites exhibited enhanced mechanical properties. The PA66-g-ND and the homogeneously dispersed PA66-g-ND in PA66 matrix were examined using X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy techniques. The mechanical properties and thermal conductivities of the nanodiamond incorporated PA66 composites were also explored. The enhanced mechanical properties and thermal conductivities of the PA66-g-ND/PA66 composites make them potential materials for new applications as functional engineered thermoplastics. PMID:27841314

  8. Reinforcement of nylon 6,6/nylon 6,6 grafted nanodiamond composites by in situ reactive extrusion

    Science.gov (United States)

    Choi, Eun-Yeob; Kim, Kiho; Kim, Chang-Keun; Kang, Eunah

    2016-11-01

    Nanodiamond (ND), an emerging new carbon material, was exploited to reinforce nylon 6,6 (PA66) polymer composites. Surface modified nanodiamonds with acyl chloride end groups were employed to chemically graft into PA66, enhancing the interfacial adhesion and thus the mechanical properties. The ND grafted PA66 (PA66-g-ND) reinforced PA66 composite prepared by in situ reactive extrusion exhibited increased tensile strength and modulus. The tensile strength and modulus of PA66/3 wt.% PA66-g-ND composites were enhanced by 11.6 and 20.8%, respectively when compared to those of the bare PA66 matrix. Even the PA66/pristine ND composites exhibited enhanced mechanical properties. The PA66-g-ND and the homogeneously dispersed PA66-g-ND in PA66 matrix were examined using X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy techniques. The mechanical properties and thermal conductivities of the nanodiamond incorporated PA66 composites were also explored. The enhanced mechanical properties and thermal conductivities of the PA66-g-ND/PA66 composites make them potential materials for new applications as functional engineered thermoplastics.

  9. Moisture dependence of positron annihilation spectra in nylon-6

    Science.gov (United States)

    Singh, J. J.; St. Clair, T. L.; Holt, W. H.; Mock, W., Jr.

    1984-01-01

    Positron annihilation time spectra have been measured in nylon-6 samples as a function of their moisture content. The measured average long life component lifetime values are: 1722 + or - 47 ps (dry), 1676 + or - 40 ps (14.6 percent saturation value), 1719 + or - 26 ps (29.3 percent saturation value), 1720 + or - 35 ps (50 percent of saturation value), 1857 + or - 35 ps (78.1 percent saturation value), and 1936 + or - 57 ps (saturated). It appears that nylon-6 has a special affinity for water at low concentration levels where H2O molecules enter between the (C = O - H-N) chemical bonds between nylon molecular chains. As the water concentration increases beyond a critical level, nylon-6 specimens start trapping H2O molecules in other bond sites or potential wells. The trapped water increases the free volume in the test specimens and reduces Ps atom formation as well as its subsequent decay rate.

  10. Electrospun nylon 6 microfiltration membrane for treatment of brewery wastewater

    Science.gov (United States)

    Islam, Md. Shahidul; Sultana, Sormin; Rahaman, Md. Saifur

    2016-07-01

    Nylon 6 microfiltration membrane, for the treatment of brewery wastewater, was fabricated using an electrospinning technique, followed by hot-pressing. The fabricated membrane was robust and demonstrated highly hydrophilic property (water contact angle 39° at the touching point to the membrane surface and the water droplet was completely immersed into the membrane in 7 seconds), and higher porosity (65%) with pore sizes of 100 to 210 nm. The electrospun nylon 6 membrane showed higher pure water flux (850 LMH) at an applied pressure of 4 psi. The same membrane also demonstrated a 95% rejection rate of suspended solids (SS) in brewery wastewater treatment.

  11. Preparation of Functionalized Core-Shell Structural Polymer with Methacrylic Acid and Modifying Nylon 6%甲基丙烯酸化核壳结构聚合物的制备及对尼龙6的改性

    Institute of Scientific and Technical Information of China (English)

    赵海燕; 李艳敏; 王占京; 张立群; 瞿雄伟

    2011-01-01

    A series of poly(BA/MMA-co-MAA) core/shell polymer(PBMMA) with different crosslinking densities were prepared by seeded emulsion polymerization.Gravimetric analysis was used to measure the conversion of monomer to polymer throughout the reactions and revealed that the polymerizations have proceeded under monomer-starved conditions(the final conversion99.4%).The good agreement shown between experimental and theoretical particle diameters throughout the polymerization for all latexes provided strong evidence that the latex particles are grown without significant secondary nucleation.When using 0.5% crosslinking agent(Allyl methacrylate,ALMA) by mass fraction,the notched Izod impact strength of PA6/PBMMA(100/20) reaches a maximal value.DMA spectra showed that the broaden breadth of the transition zone at low temperature glass transition region and the weaken magnitude of loss peak of nylon 6(Tα) improve the compatibility between nylon 6 matrix and PBMMA particles.The SEM observation verified the results of modifying nylon 6.%采用种子乳液聚合方法制备了一系列交联度不同的核壳结构聚丙烯酸丁酯/甲基丙烯酸甲酯-甲基丙烯酸共聚物Poly(BA/MMA-co-MAA),简称PBMMA,单体总转化率达99.4%,乳胶粒径为302 nm,且理论值与实测值基本一致,说明该体系没有明显的二次成核过程。当交联剂质量分数为0.5%时,尼龙6/PBMMA(100/20)共混物的缺口冲击强度最大。DMA谱图表明,改性体系低温及尼龙6的α玻璃化转变区域变宽及损耗峰幅度减弱,使得尼龙6与PBMMA间有良好的相容性。SEM观察证实了这种改性效果。

  12. Dispersion of nano-silica in monomer casting nylon6 and its effect on the structure and properties of composites

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available To promote dispersion of nano-silica in monomer casting nylon6 (MC nylon6, nano-silica was dispersed in melted caprolactam with the assistance of ultrasound, anionic polymerization was then initiated to form silica/MC nylon6 in-situ nanocomposites. It was found that hydrogen bonds were formed between nano-silica and caprolactam, in the meantime, ultrasound helped to break the nanoparticles aggregations into smaller ones or even mono-dispersing particles. Therefore, the agglomerated nanoparticles were pulled apart and stabilized by caprolactam. Additionally, the rapid anionic polymerization of caprolactam also contributed to the avoidance of re-agglomeration and deposition of nanoparticles during the polymerization process, leading to the uniform distribution of nanoparticles in the polymer matrix. Mechanical tests indicated that the silica/MC nylon6 in-situ nanocomposites prepared according to the above strategy were simultaneously toughened, strengthened and stiffened. Thermogravimetric analysis (TGA results showed that thermal stability of nanocomposites was notably improved compared to neat MC nylon6.

  13. Migration of divalent ions in nylon 6 films

    NARCIS (Netherlands)

    Reuvers, N.J.W.; Huinink, H.P.; Fischer, H.R.; Adan, O.C.G.

    2014-01-01

    The migration of ions through a nylon-6 film is studied by MRI. For this study the paramagnetic ions Mn2+ and Cu2+ are used as they act as a contrast agent and are detectable by MRI. The ingress of water and ions in nylon occurs at different rates. First, water is absorbed in the nylon. Second, the

  14. Migration of divalent ions in nylon 6 films

    NARCIS (Netherlands)

    Reuvers, N.J.W.; Huinink, H.P.; Fischer, H.R.; Adan, O.C.G.

    2014-01-01

    The migration of ions through a nylon-6 film is studied by MRI. For this study the paramagnetic ions Mn2+ and Cu2+ are used as they act as a contrast agent and are detectable by MRI. The ingress of water and ions in nylon occurs at different rates. First, water is absorbed in the nylon. Second, the

  15. Continuous electrospinning of polymer nanofibers of Nylon-6 using an atomic force microscope tip.

    Science.gov (United States)

    Gururajan, Giriprasath; Sullivan, S P; Beebe, T P; Chase, D B; Rabolt, J F

    2011-08-01

    An atomic force microscopy (AFM) probe is successfully utilized as an electrospinning tip for fabricating Nylon-6 nanofibers. The nanometre-size tip enabled controlled deposition of uniform polymeric nanofibers within a 1 cm diameter area. Nylon-6 nanofibers were continuously electrospun at a solution concentration as low as 1 wt% Nylon-6 in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). Wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) results of the AFM electrospun fibers indicated that the nanofibers predominantly display the meta-stable γ crystalline form suggesting rapid crystallization rate during the process. In addition to precise control over fiber deposition and diameter, some of the drawbacks of conventional electrospinning such as large volume of solutions and clogging of needles can be overcome using this AFM based electrospinning technique. Lastly, a comparison of electrospun fibers from syringe-needle based electrospinning and AFM probe-tip based electrospinning indicated significant morphological and microstructural differences in the case of AFM based electrospinning.

  16. Morphology and Mechanical Properties of Nylon 6/PBT Blends Compatibilized with Styrene/Maleic Anhydride Copolymer

    Institute of Scientific and Technical Information of China (English)

    QIN Shu-hao; YU Jie; ZHENG Qiang; HE Min; ZHU Hong

    2007-01-01

    The mechanical properties and dynamic mechanical properties of blends composed of Nylon 6 and poly( butylenes terephthalate) (PBT), with styrene/maleic anhydride(SMA) as compatibilizer, were studied. The observation on the morphologies of the etched surfaces of the cryogenically fractured specimens via scanning electron microscopy(SEM)demonstrated that in the compatibilized Nylon 6/PBT blends, there exists a finer and more uniform dispersion induced by thein-situ interfacial chemical reactions during the preparation than that in the corresponding uncompatibilized blends. On the other hand, the overall mechanical properties of the compatibilized blends could be remarkably improved compared with those of the uncompatibilized ones. Moreover, increasing the amount of the compatibilizer SMA leads to a more efficient dispersion of the PBT phase in Nylon 6/PBT blends. Furthermore, there exists an optimum level of SMA added to achieve the maximum mechanical properties. As far as the mechanism of this reactive compatibilization is concerned, the enhanced interfacial adhesion is necessary to obtain improved dispersion, stable phase morphology, and better mechanical properties.

  17. Tuning the mechanical properties of SWNT/nylon 6,10 composites with flexible spacers at the interface.

    Science.gov (United States)

    Moniruzzaman, Mohammad; Chattopadhyay, Jayanta; Billups, W Edward; Winey, Karen I

    2007-05-01

    We have prepared nylon 6,10 nanocomposites using functionalized single wall carbon nanotubes and our interfacial in situ polycondensation method. The specific functional groups -(CH2)nCOCl [n = 4 and 9] on the sidewalls of SWNT were designed to covalently link nanotubes to the nylon matrix via alkyl segments. The composites with functionalized SWNT show significant improvements in tensile modulus, strength, and toughness relative to nylon and nylon modified with non-functionalized SWNT. The alkyl linkages at the SWNT/nylon 6,10 interface contribute significantly to improving the toughness of the composites.

  18. Investigation on Effect of PVP on Morphological Changes and Crystallization Behavior of Nylon 6 in PVP/Nylon 6 Blends by FTIR Spectroscopy%PVP对Nylon 6形貌及结晶行为影响的研究

    Institute of Scientific and Technical Information of China (English)

    郝超伟; 赵莹; 李万利; 徐怡庄; 王笃金; 徐端夫

    2008-01-01

    采用变温红外光谱、示差扫描量热(DSC)和偏光显微镜(POM)等方法研究了聚乙烯吡咯烷酮(PVP)与尼龙6(nylon 6)分子间的相互作用及其对nylon 6热行为及结晶形貌的影响.DSC结果表明PVP的加入明显影响了nylon 6的熔融和结晶行为:随着PVP含量增加,PVP/nylon 6共混物的结晶温度、熔融温度及结晶度均逐渐降低;POM观察显示:随着PVP含量增多,nylon 6的球晶尺寸变小、球晶逐渐变得不完善.变温红外光谱结果表明,无定形PVP分子的羰基能够与nylon 6分子的N-H基团形成新的氢键,部分破坏了nylon 6分子之间的氢键结构,从而阻碍了nylon 6分子的规整排列,使其结晶度降低并导致nylon6结晶形貌的变化.

  19. Electrospinning and Porosity Measurements of Nylon-6/Poly(ethylene oxide Blended Nonwovens

    Directory of Open Access Journals (Sweden)

    Margaret W. Frey, Ph.D.

    2007-04-01

    Full Text Available A simple method was used to prepare a nonwoven fabric of intimately co-mingled Nylon-6 and Polyethylene oxide (PEO electrospun fibers by spinning fibers onto a rotating collector. Electrospinning parameters for each polymer were independent. Fiber mixture and distribution was uniform throughout the depth of the fabric. Porosity and pore size distribution of the materials were measured before and after a washing treatment. The PEO component was removed during the washing step to create increased pore size in the remaining fabric. This study indicates a simple method to create nanofiber nonwovens of multiple dissimilar polymers and provides a strategy for controlling pore size distribution independently from fiber formation.

  20. Cellulose fiber reinforced nylon 6 or nylon 66 composites

    Science.gov (United States)

    Xu, Xiaolin

    Cellulose fiber was used to reinforce higher melting temperature engineering thermoplastics, such as nylon 6 and nylon 66. The continuous extrusion - direct compression molding processing and extrusion-injection molding were chosen to make cellulose fiber/nylon 6 or 66 composites. Tensile, flexural and Izod impact tests were used to demonstrate the mechanical properties of the composites. The continuous extrusion-compression molding processing can decrease the thermal degradation of cellulose fiber, but fiber doesn't disperse well with this procedure. Injection molding gave samples with better fiber dispersion and less void content, and thus gave better mechanical properties than compression molding. Low temperature compounding was used to extrude cellulose fiber/nylon composites. Plasticizer and a ceramic powder were used to decrease the processing temperature. Low temperature extrusion gave better mechanical properties than high temperature extrusion. The tensile modulus of nylon 6 composite with 30% fiber can reach 5GPa; with a tensile strength of 68MPa; a flexural modulus of 4GPa, and a flexural strength of 100MPa. The tensile modulus of nylon 66 composites with 30% fiber can reach 5GPa; with a flexural modulus of 5GPa; a tensile strength of 70MPa; and a flexural strength of 147MPa. The effect of thermal degradation on fiber properties was estimated. The Halpin-Tsai model and the Cox model were used to estimate the composite modulus. The Kelly-Tyson model was used to estimate the composite strength. The result indicates that the change of fiber properties determines the final properties of composites. Fiber length has a minor affect on both modulus and strength as long as the fiber length is above the critical length.

  1. Low-temperature thermal conductivity of Nylon-6/Cu nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Martelli, V., E-mail: martelliv@fi.infn.i [INFN, Section of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino, Florence (Italy); LENS, University of Florence, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Toccafondi, N. [Department of Chemistry - CSGI, University of Florence, Via Lastruccia 3, 50019 Sesto Fiorentino, Florence (Italy); Ventura, G. [INFN, Section of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino, Florence (Italy); Department of Physics, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino, Florence (Italy)

    2010-10-15

    We have produced a new nanocomposite material made up of a Nylon-6 matrix in which metallic copper nanoparticle (5% in weight) are uniformly dispersed. Here we report about the measurement of the thermal conductivity of such material between 0.1 and 30 K. Thermal conductivity of the nanocomposite does not substantially differ from that of Nylon. Nevertheless data show interesting features, in particular a sharp dip at 1.4 K which can be interpreted as a resonant scattering of phonons by copper nanoparticles.

  2. Synthesis of Ag/CNT hybrid nanoparticles and fabrication of their Nylon-6 polymer nanocomposite fibers for antimicrobial applications

    Science.gov (United States)

    Rangari, Vijaya K.; Mohammad, Ghouse M.; Jeelani, Shaik; Hundley, Angel; Vig, Komal; Ram Singh, Shree; Pillai, Shreekumar

    2010-03-01

    Ag-coated CNTs hybrid nanoparticles (Ag/CNTs) were prepared by ultrasonic irradiation of dimethylformamide (DMF) and silver (I) acetate precursors in the presence of CNTs. The morphology of Ag/CNTs was characterized using x-ray diffraction and transmission electron microscopy (TEM) techniques. The Nylon-6 powder and 1 wt% Ag/CNTs mixture was dispersed uniformly using a noncontact spinning technique. The dried mixture was melted in a single screw extrusion machine and then extruded through an orifice. Extruded filaments were later stretched and stabilized by sequentially passing them through a set of tension adjusters and a secondary heater. The Nylon-6/Ag/CNT hybrid polymer nanocomposite (HPNC) fibers, which were of ~ 80 µm size, were tested for their tensile properties. The failure stress and modulus of the extruded HPNC fibers (doped with 1% Ag/CNTs) was about 72.19 % and 342.62% higher than the neat extruded Nylon-6 fiber, respectively. DSC results indicated an increase in the thermal stability and crystallization for HPNC fibers. The antibacterial activity of the Ag-coated CNTs, commercial Ag, neat Nylon-6 and plain CNTs were evaluated. Ag-coated CNTs at 25 µg demonstrated good antimicrobial activity against four common bacterial pathogens as tested by the Kirby-Bauer assay. The mean diameters of the zones of inhibition were 27.9 ± 6.72 mm, 19.4 ± 3.64 mm, 21.9 ± 4.33 mm, and 24.1 ± 4.14 mm, respectively, for Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Salmonella enterica serovar Typhimurium. By comparison, those obtained using the broad spectrum antibiotic amoxicillin-clavulanic acid were 37.7 ± 2.13 mm, 28.6 ± 4.27 mm, 22.6 ± 1.27 mm, and 27.0 ± 1.41 mm, respectively, for the same strains. The zones of inhibition obtained for Nylon-6 Ag-coated CNT powder at 25 µg were also high, ranging from 15.2 to 25.3 mm in contrast to commercial silver or neat Nylon-6, which did not inhibit the bacterial strains tested. Further, the

  3. Synthesis of Ag/CNT hybrid nanoparticles and fabrication of their Nylon-6 polymer nanocomposite fibers for antimicrobial applications

    Energy Technology Data Exchange (ETDEWEB)

    Rangari, Vijaya K; Mohammad, Ghouse M; Jeelani, Shaik [Materials Science and Engineering, Center for Advanced Materials, Tuskegee University, Tuskegee, AL 36088 (United States); Hundley, Angel; Vig, Komal; Singh, Shree Ram; Pillai, Shreekumar, E-mail: rangariv@tuskegee.edu [Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL 36104 (United States)

    2010-03-05

    Ag-coated CNTs hybrid nanoparticles (Ag/CNTs) were prepared by ultrasonic irradiation of dimethylformamide (DMF) and silver (I) acetate precursors in the presence of CNTs. The morphology of Ag/CNTs was characterized using x-ray diffraction and transmission electron microscopy (TEM) techniques. The Nylon-6 powder and 1 wt% Ag/CNTs mixture was dispersed uniformly using a noncontact spinning technique. The dried mixture was melted in a single screw extrusion machine and then extruded through an orifice. Extruded filaments were later stretched and stabilized by sequentially passing them through a set of tension adjusters and a secondary heater. The Nylon-6/Ag/CNT hybrid polymer nanocomposite (HPNC) fibers, which were of {approx} 80 {mu}m size, were tested for their tensile properties. The failure stress and modulus of the extruded HPNC fibers (doped with 1% Ag/CNTs) was about 72.19 % and 342.62% higher than the neat extruded Nylon-6 fiber, respectively. DSC results indicated an increase in the thermal stability and crystallization for HPNC fibers. The antibacterial activity of the Ag-coated CNTs, commercial Ag, neat Nylon-6 and plain CNTs were evaluated. Ag-coated CNTs at 25 {mu}g demonstrated good antimicrobial activity against four common bacterial pathogens as tested by the Kirby-Bauer assay. The mean diameters of the zones of inhibition were 27.9 {+-} 6.72 mm, 19.4 {+-} 3.64 mm, 21.9 {+-} 4.33 mm, and 24.1 {+-} 4.14 mm, respectively, for Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Salmonella enterica serovar Typhimurium. By comparison, those obtained using the broad spectrum antibiotic amoxicillin-clavulanic acid were 37.7 {+-} 2.13 mm, 28.6 {+-} 4.27 mm, 22.6 {+-} 1.27 mm, and 27.0 {+-} 1.41 mm, respectively, for the same strains. The zones of inhibition obtained for Nylon-6 Ag-coated CNT powder at 25 {mu}g were also high, ranging from 15.2 to 25.3 mm in contrast to commercial silver or neat Nylon-6, which did not inhibit the bacterial

  4. Physicochemical characterization of chitosan/nylon6/polyurethane foam chemically cross-linked ternary blends.

    Science.gov (United States)

    Jayakumar, S; Sudha, P N

    2013-03-15

    Chitosan/nylon6/polyurethane foam (CS/Ny6/PUF) ternary blend was prepared and chemically cross-linked with glutaraldehyde. Structural, thermal and morphological studies were performed for the prepared ternary blends. Characterizations of the ternary blends were investigated by Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM). The FTIR results showed that the strong intermolecular hydrogen bonds took place between CS, Ny6 and PUF. TGA and DSC studies reveal that the thermal stability of the blend is enhanced by glutaraldehyde as crosslinking agent. Results of XRD indicated that the relative crystalline of pure CS film was reduced when the polymeric network was reticulated by glutaraldehyde. Finally, the results of scanning electron microscopy (SEM) indicated that the morphology of the blend is rough and heterogeneous, further it confirms the interaction between the functional groups of the blend components.

  5. Physicochemical characterization of chitosan/nylon6/polyurethane foam chemically cross-linked ternary blends

    Science.gov (United States)

    Jayakumar, S.; Sudha, P. N.

    2013-03-01

    Chitosan/nylon6/polyurethane foam (CS/Ny6/PUF) ternary blend was prepared and chemically cross-linked with glutaraldehyde. Structural, thermal and morphological studies were performed for the prepared ternary blends. Characterizations of the ternary blends were investigated by Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM). The FTIR results showed that the strong intermolecular hydrogen bonds took place between CS, Ny6 and PUF. TGA and DSC studies reveal that the thermal stability of the blend is enhanced by glutaraldehyde as crosslinking agent. Results of XRD indicated that the relative crystalline of pure CS film was reduced when the polymeric network was reticulated by glutaraldehyde. Finally, the results of scanning electron microscopy (SEM) indicated that the morphology of the blend is rough and heterogeneous, further it confirms the interaction between the functional groups of the blend components.

  6. Rheological characterization of nanocomposites Nylon 6/bentonite clay; Caracterizacao reologica de nanocompositos de poliamida 6/argila bentonitica

    Energy Technology Data Exchange (ETDEWEB)

    Silva, T.R.G.; Fernandes, P.C.; Oliveira, S.V., E-mail: taci_gouveia@yahoo.com.b [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Curso de Pos-Graduacao em Ciencia e Engenharia de Materiais; Araujo, E.M.; Melo, T.J.A. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2010-07-01

    Polymer nanocomposites are a class of materials that have been widely used in various applications. Among them, has been emphasizing the preparation of polymer films with barrier properties for applications in polymer membranes. In this work, nanocomposites of nylon 6/bentonite clay were obtained from a Homogenizer, in the ratios of 1, 3 and 5 wt% clay. The Brasgel PA bentonite clay was treated organically with Praepagen HY salt, to make it organophilic. By X-ray diffraction (XRD), it was showed that the efficiency of the incorporation of salt in the clay. The rheological curves showed that for the AST clay the torque did not change when compared with the pure nylon 6, while for the clay ACT, the torque increased gradually with the percentage of clay. (author)

  7. IN SITU COMPATIBILIZATION OF LDPE/NYLON-6 BLEND USING LOW MOLECULAR WEIGHT INTERFACIAL AGENT AS A CHEMICAL COMPATIBILIZER

    Institute of Scientific and Technical Information of China (English)

    LI Pei; ZHANG Ruifeng; Chung Long Choy

    1997-01-01

    In situ compatibilization of low density polyethylene (LDPE) (30%) and nylon-6 (70%) blends through one-step reactive extrusion using t-BuOOH as an initiator and low molecular weight interfacial agents as compatibilizers was studied. The compatibilizer contained a long chain hydrocarbon, double bond and two polar functional groups which was capable of reacting with both LDPE and nylon-6 in the presence of initiator to form a copolymer at the interface of the two polymer phases. The extruded blends exhibited significant enhancement in their compatibility based on morphological, thermal analysis and mechanical studies. The effect of the hydrocarbon chain length and structure of the functional group of the compatibilizer was also examined. It was found that blends prepared by using the compatibilizer containing longer hydrocarbon chain and amide group had better mechanical properties.

  8. NAPHTHALIMIDE BASED DISPERSE DYES FOR NYLON 6 AND POLYESTER (PET) FIBERS: SYNTHESIS AND EVALUATION OF TECHNICAL PROPERTIES IN THE PRESENCE OF UREA

    Institute of Scientific and Technical Information of China (English)

    Javad Mokhtari; Mahdi Nouri; Uranus Goudarzi

    2011-01-01

    Technical properties of two naphthalimide based disperse dyes on nylon 6 and polyester fibers were investigated in the presence of urea.The two naphthalimide based disperse dyes were synthesized.The dyes were purified and then fully characterized using 1H-NMR,FTIR and melting point analysis.Dispersion of the dyes was prepared in water and applied on nylon 6 and PET fibers.The dyes offered good build-up properties on the substrates.In order to increase dye adsorption of the substrates,urea was added into the dyebath.By adding urea,the dye adsorption of polyester was increased significantly,while the increase of that of nylon 6 was not marked.The dyes showed good fastness properties on the substrates.

  9. STUDY ON NYLON 6/SUPERFINE RUBBER PARTICLES COMPOSITES VIA IN SITU POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Ying Li; Jian Yu; Zhao-xia Guo; Jin-liang Qiao

    2003-01-01

    Two highly cross-linked superfine styrene-butadiene rubber particles, one with 1 wt% of carboxyl groups and the other without such groups having particle sizes of 130-150 nm and 80-100 nm respectively, were used to prepare nylon 6/rubber composites via in situ polymerization. It was found that carboxylic styrene-butadiene dispersed uniformly in nylon matrix and there was strong interfacial interaction because of the graft polymer formed by the reaction of nylon with carboxyl group of the rubber, resulting in considerably improved impact strength with almost unchanged tensile strength. However,the addition of styrene-butadiene without carboxyl groups showed intensive agglomeration of the rubber particles and weak interfacial interactions, and the toughness of the materials was improved slightly. The crystallization and rheological behavior of the composites were also discussed.

  10. Drawing Nylon 6,6 Fibers in High Pressure CO2

    Science.gov (United States)

    2005-12-07

    studies have been performed on various fibers using supercritical carbon dioxide treatments. In these studies, Nylon6,6, PBO ( Zylon ) and...Supercritical carbon dioxide, High Performance Fibers , Nylon6,6, PBO ( Zylon ), Polyester Fibers 15. NUMBER OF PAGES...conducted on poly-p-phenylenebenzobisoxazole (PBO) currently manufactured by Toyobo under the commercial name Zylon . These fibers were selected because of

  11. Quantitative water uptake study in thin nylon-6 films with NMR imaging

    NARCIS (Netherlands)

    Reuvers, N.J.W.; Huinink, H.P.; Fischer, H.R.; Adan, O.C.G.

    2012-01-01

    Nylon-6 is widely used as an engineering plastic. Compared to other synthetic polymers, nylon-6 absorps significant amounts of water. Although the typical sorbed amounts and diffusivity of water are well-known, less is known about the relation between the diffusivity and the water content. Attempts

  12. Data on the growth of ZnO nanorods on Nylon 6 and photocatalytic activity

    Directory of Open Access Journals (Sweden)

    S. Ummartyotin

    2016-09-01

    Full Text Available ZnO was successfully synthesized by a conventional synthetic route using zinc nitrate as a source for ZnO formation. X-ray diffraction and thermogravimetric analysis revealed a crystal size of 66 nm of ZnO and a thermal stability of 500 °C. A small amount of ZnO particles was employed as the source for ZnO-rod growth on nylon 6 surfaces. Scanning electron microscope images were taken to evaluate the morphological properties of ZnO, which presented as a hexagonal needle-like shape. Preliminary evaluation of photocatalytic activity was performed through measurement of the degradation of methylene blue solution over 4 h.

  13. Manufacture and characterization of silver and copper nanostructures produced via forcespun Nylon 6 nanofibers

    Science.gov (United States)

    Zhao, Wenqian

    Nylon 6 nanofibers were produced using the ForcespinningRTM method and were deposited with silver or copper thin films using the high vacuum thermal evaporation technique for surface functionalization of nanostructures. The changes in surface composition, morphology and surface energy of native and metallic coated Nylon 6 nanofibers were examined. Their antibacterial properties of native, silver or copper coated Nylon 6 nanofibers were tested. Furthermore, the Nylon 6 nanofibers were used as templates in order to obtain silver or copper nanotubes where the polymer was removed after high temperature calcination. The metallic coated Nylon 6 nanofibers and metallic nanotubes morphology and electrical behavior are characterized using the SEM, STEM, XRD, EDS and electrical measurements.

  14. Development of reaction injection molding nylon 6%反应注射成型尼龙6的研究进展

    Institute of Scientific and Technical Information of China (English)

    邓鑫; 王进; 杨军; 李笃信

    2009-01-01

    This review introduces the characteristics and research development of reaction injection molding nylon 6 (nylon 6-RIM), reinforced reaction injection molding nylon 6 (nylon 6-RRIM), mat-molding reaction injection molding nylon 6 (nylon 6-MMRIM) and nylon 6 block copolymer RIM (NBC-RIM). The application advantages of nylon 6-RIM in various fields are discussed.%介绍了反应注射成型尼龙6(nylon 6-RIM)、增强反应注射成型尼龙6(nylon 6-RRIM)、毡片模塑反应注射成型尼龙6(nylon 6-MMRIM)以及反应注射成型尼龙6嵌段共聚物(NBC-RIM)材料的性能特点以及研究进展.并讨论了nylon 6-RIM材料在各个领域的应用优势和前景.

  15. Non-isothermal crystallization kinetics of reactive microgel/nylon 6 blends☆

    Institute of Scientific and Technical Information of China (English)

    Min He; Siqi Zong; Yahuan Zhou; Huaibing Guo; Qingchun Fan

    2015-01-01

    The non-isothermal crystal ization kinetics of reactive microgel/nylon 6 blends was investigated by differential scanning calorimetry (DSC). The Mo equation was employed to analyze the non-isothermal crystallization data. The crystallization activation energies were also evaluated by the Kissinger method. The results show that the crystallization onset temperature (Tonset) and crystallization peak temperature (Tp) decrease with the increase of the content of reactive microgel, whileΔT (Tonset–Tp), the crystallization half-time (t1/2) and the crystal ization enthalpy (ΔHc) increase. The required cooling rates of blends are higher than that of neat nylon 6 in order to achieve the same relative crystallinity in a unit of time. The crystallization activation energies of the reactive microgel/nylon 6 blends are greater than those of the neat nylon 6. When the content of reactive microgel is 30%, the relative crystallinity (Xt) reaches the maximum.

  16. [Research on structure of MC-nylon 6/aramid composites by spectroanalysis method].

    Science.gov (United States)

    Wang, Can-Yao; Zheng, Yu-Ying

    2008-01-01

    The Kevlar fiber, treated with toluene-2,4-diisocyanate and caprolactam, was used to reinforce MC nylon 6. XPS showed the change in chemical components and spectra after fiber was treated. IR showed that the spectra of Kevlar fiber and MC-nylon 6 were incorporated purely when they were mixed, while the treated Kevlar fiber provided the activation in the ring-opening polymerization of caprolactam, and the amide groups of graft chains could form strong hydrogen bonds with matrix. These graft chains and hydrogen bonds would contribute to improving interfacial bonding between MC-nylon 6 and Kevlar fiber. XRD indicated that the induction of Kevlar fiber had no effect on the cryastalline style of MC-nylon 6 obviously, however, the crystals had better seasonal structure. The crystals of MC-nylon 6/Kevlar fiber composites were more perfect than that of MC-nylon 6/Kevlar untreated fiber composites with the same amount of Kevlar fiber. The increase of Kevlar fiber contributed to forming perfect a spherulite when the mass concentration of Kevlar fiber was less than 2%, however, the more the Kevlar fiber, the less the content of a spherulite when the mass concentration of Kevlar fiber was more than 2%.

  17. Effect of different percent loadings of nanoparticles and food processing conditions on the properties of nylon 6 films

    Science.gov (United States)

    Allafi, Ahmad R.

    Nylon 6 organoclay nanocomposites were prepared by melt processing using a twin screw extruder. Five different films were produced with five different % loadings (0, 2, 4, 6, and 8%). This study had three main objectives. The first was to investigate the effects of loading percentages on the barrier, thermal and mechanical properties of nylon 6 nanocomposite materials. The second was to study the effects of 0, 50 and 80% RH on the oxygen permeation of the nylon 6/nanocomposite films. The third was to investigate the properties of nylon 6 nanocomposite materials exposed to typical food processing conditions. These films were tested for their permeabilities to oxygen (OTR), carbon dioxide (CO2TR), and water vapor (WVTR). Thermal properties testing on the samples included differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Tensile strength at break, tensile modulus at break, and the percent elongation for the five films were examined using an INSTRON tester. Transmission electron microscopy (TEM) was used to investigate the morphology of the five films. Results showed that all gas barriers significantly increased with percent loading but there were no significant differences (P>0.05) between the 6 and 8% for the CO2TR. For the DMA, the storage modulus also significantly increased (P<0.05) with increasing loading except between the 2 and 4% concentrations. For the DSC analyses, enthalpy of fusion decreased slightly from an average of 39 J/g (control) to 32J/g (8% loading). The melt temperature also decreased from 227 to 222°C between those loadings. High pressure processed samples had the highest barrier against oxygen permeation when compared with the retorted and controls. Retorting seemed to reduce the tensile strength slightly; however, no significant changes in modulus and elongation occurred after retorting and HPP. These results showed that increasing percent loadings increased the stiffness of the material at the expense of its

  18. Novel melt-processable nylon-6/inorganic fullerene-like WS{sub 2} nanocomposites for critical applications

    Energy Technology Data Exchange (ETDEWEB)

    Naffakh, Mohammed, E-mail: mnaffakh@ictp.csic.es [Departamento de Fisica e Ingenieria de Polimeros, Instituto de Ciencia y Tecnologia de Polimeros, CSIC, c/Juan de la Cierva, 3, 28006 Madrid (Spain); Marco, Carlos; Gomez, Marian A. [Departamento de Fisica e Ingenieria de Polimeros, Instituto de Ciencia y Tecnologia de Polimeros, CSIC, c/Juan de la Cierva, 3, 28006 Madrid (Spain); Jimenez, Ignacio [Instituto de Ciencia de Materiales de Madrid, CSIC, Campus de Cantoblanco, 28049 Madrid (Spain)

    2011-09-15

    Highlights: {yields} Environmentally-friendly IF-WS{sub 2} is used to produce advanced nylon-6 NCPs. {yields} Novel IF-WS{sub 2} improves the thermal and mechanical performances of nylon-6. {yields} IF-WS{sub 2} is effective in reducing the friction coefficient of nylon-6. {yields} New insights into polymorphic behaviour of nylon-6 in NCPs. - Abstract: Environmentally-friendly inorganic fullerene-like tungsten disulfide nanoparticles (IF-WS{sub 2}) were used to produce new nylon-6 nanocomposites. The addition of IF-WS{sub 2} is an effective way to improve the thermal, mechanical and tribological properties of polymeric materials. In the present work, the nylon-6/IF-WS{sub 2} nanocomposites were processed by advantageously traditional melt processing technique. The IF-WS{sub 2} nanoparticles do not require exfoliation or modification, making it possible to obtain stronger and lighter materials without the complexity and processing cost associated with these treatments. The thermo-oxidative stability of nylon-6/IF-WS{sub 2} nanocomposites was studied using thermogravimetric analysis. The thermal behaviour and crystalline phase transition of nylon-6 were investigated using DSC and time-resolved synchrotron X-ray diffraction in order to obtain a picture describing the physico-chemical transformation of nylon-6 molecules from the non-ordered state to the ordered state. Dynamic mechanical analysis and tribological tests had been carried out to evaluate the effect of IF-WS{sub 2} on the mechanical performance, friction and wear behaviour of nylon-6/IF-WS{sub 2} nanocomposites. The results showed that significant improvement can be achieved in the thermal, mechanical and tribological properties of nylon-6 nanocomposites. In addition, the incorporation of IF-WS{sub 2} nanoparticles has shown to be an effective way to promote the crystallization process of nylon-6, which also influences the crystalline transformation of nylon-6 (i.e. Brill transition) observed during both

  19. EELS Analysis of Nylon 6 Nanofibers Reinforced with Nitroxide-Functionalized Graphene Oxide

    Science.gov (United States)

    Leyva-Porras, César; Ornelas-Gutiérrez, C.; Miki-Yoshida, M.; Avila-Vega, Yazmín I.; Macossay, Javier; Bonilla-Cruz, José

    2014-01-01

    A detailed analysis by transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) of nitroxide-functionalized graphene oxide layers (GOFT) dispersed in Nylon 6 nanofibers is reported herein. The functionalization and exfoliation process of graphite oxide to GOFT was confirmed by TEM using electron diffraction patterns (EDP), wherein 1 to 4 graphene layers of GOFT were observed. The distribution and alignment of GOFT layers within a sample of Nylon 6 nanofiber reveals that GOFT platelets are mainly within the fiber, but some were partially protruding from it. Furthermore, Nylon 6 nanofibers exhibit an average diameter of 225 nm with several microns in length. GOFT platelets embedded into the fiber, the pristine fiber, and amorphous carbon were analyzed by EELS where each spectra [corresponding to the carbon edge (C-K)] exhibited changes in the fine structure, allowing a clear distinction between: i) GOFT single-layers, ii) Nylon-6 nanofibers, and iii) the carbon substrate. EELS analysis is presented here for the first time as a powerful tool to identify functionalized graphene single-layers (< 4 layers of GOFT) into a Nylon 6 nanofiber composite. PMID:24634536

  20. Fabrication and characterization of silver- and copper-coated Nylon 6 forcespun nanofibers by thermal evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Mihut, Dorina M., E-mail: dorinamm@yahoo.com; Lozano, Karen [Department of Mechanical Engineering, The University of Texas Pan American, 1201 W University Drive, Edinburg, Texas 78539 (United States); Foltz, Heinrich [Department of Electrical Engineering, The University of Texas Pan American, 1201 W University Drive, Edinburg, Texas 78539 (United States)

    2014-11-01

    Silver and copper nanoparticles were deposited as thin films onto substrates consisting of Nylon 6 nanofibers manufactured using forcespinning{sup ®} equipment. Different rotational speeds were used to obtain continuous nanofibers of various diameters arranged as nonwoven mats. The Nylon 6 nanofibers were collected as successive layers on frames, and a high-vacuum thermal evaporation method was used to deposit the silver and copper thin films on the nanofibers. The structures were investigated using scanning electron microscopy–scanning transmission electron microscopy, atomic force microscopy, x-ray diffraction, and electrical resistance measurements. The results indicate that evaporated silver and copper nanoparticles were successfully deposited on Nylon 6 nanofibers as thin films that adhered well to the polymer substrate while the native morphology of the nanofibers were preserved, and electrically conductive nanostructures were achieved.

  1. Dielectric loss of N-substituted nylon 6.6 and of polyester 6.6

    NARCIS (Netherlands)

    Bunk, Adriaan J.H.; Regtuit, Hans G.; Berg, van den Johannes W.A.; Gaymans, Reinoud J.; Schuyer, Jan

    1975-01-01

    In this report the results are summarized of measurements concerning the influence of intermolecular hydrogen bridge formation on the mechanisms responsible for the so-called p- and y-relaxations in the dielectric loss spectrum of nylon 6.6’) (see McCrum et al.’, p. 478497). To that end the loss spe

  2. Dielectric loss of N-substituted nylon 6.6 and of polyester 6.6

    NARCIS (Netherlands)

    Bunk, Adriaan J.H.; Regtuit, Hans G.; van den Berg, J.W.A.; Gaymans, R.J.; Schuyer, Jan

    1975-01-01

    In this report the results are summarized of measurements concerning the influence of intermolecular hydrogen bridge formation on the mechanisms responsible for the so-called p- and y-relaxations in the dielectric loss spectrum of nylon 6.6’) (see McCrum et al.’, p. 478497). To that end the loss spe

  3. One-step synthesis of silver nanoparticle-filled Nylon 6 nanofibers and their antibacterial properties

    Science.gov (United States)

    A novel and facile one-step approach to in situ synthesize silver nanoparticle-filled nylon 6 nanofibers by electrospinning is reported. The method does not need post-treatments and can be carried out at ambient conditions without using additional chemicals. It employs the electrospinning solvent as...

  4. Development of rapid continuous dyeing process for heavy-weight nylon 6,6 carpet

    Science.gov (United States)

    An improved continuous dyeing process for coloration of heavy-weight (60-70 oz/yd2), residential nylon 6,6 carpet is reported. By inserting a slot steam applicator after the dye pad and before the box steamer to preheat the carpet to around 180°F (greater than the nylon wet glass transition temperat...

  5. Effect of cellulose fiber reinforcement on the temperature dependent mechanical performance of nylon 6

    Science.gov (United States)

    Mehdi Tajvidi; Mokhtar Feizmand; Robert H. Falk; Colin Felton

    2009-01-01

    In order to quantify the effect of temperature on the mechanical properties of pure nylon 6 and its composite with cellulose fibers (containing 25 wt% cellulose fibers), the materials were sampled and tested at three representative temperatures of 256, 296, and 336 K. Flexural and tensile tests were performed and the reductions in mechanical properties were evaluated....

  6. Tribological Behavior of MC Nylon6 Composites Filled with Glass Fiber and Fly ash

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shihua; CUI Chong; CHEN Guang

    2012-01-01

    To improve tribological property of MC Nylon6,the glass fiber and fly ash reinforced monomer casting nylon composites (GFFAPA) were prepared by anionic polymerization of ε-caprolactam.The friction and wear behaviors of composites under dry condition,water lubrication and oil lubrication were investigated through a ring-black wear tester.Worn surfaces were analyzed using a scanning electron microscope.The experimental results show that the tensile strength and hardness of nylon composites are obviously improved with reinforcement increasing.Compared to MC nylon,the lowest friction coefficient and wear rate of glass fiber reinforced nylon composites (GFPA) with GF30% respectively decrease by 33.1% and 65.3%,of fly ash reinforced nylon composites (FAPA) with FA20% decrease by 5.2% and 68.9% and of GFFAPA composites with GF30% and FA10% decrease by 57.8% and 89.9%.The main wear mechanisms of FAPA composites are adhesive and abrasive wear and of GFPA composites with high proportion are abrasive and fatigue wear.The worn surfaces of GFFAPA composites are much multiplex and the optional distributing glass fiber and fly ash have a synergetic effect on the wear resistance for GFFAPA composites.Compared with dry friction,the friction coefficient and wear rate under oil lubricated conditions decrease sharply while the latter reversely increase under water lubricated conditions.The wear mechanisms under water lubricated condition are principally chemical corrosion wear and abrasive wear and they become boundary friction under oil lubricated condition.

  7. Synthesis and Characterization of Star-Shaped Nylon 6 with Four Arms%四臂星型尼龙6的合成与表征

    Institute of Scientific and Technical Information of China (English)

    付鹏; 井琼琼; 刘民英; 杨韶辉; 王玉东; 赵清香

    2011-01-01

    Four kinds of star-shaped nylon 6 samples with different branched-chain length were prepared by the hydrolytic polymerization of ε-caprolactam using 2,2,6,6-tetra(β-carboxyethyl)cyclohexanone as tetrafunctional reactant.The molecular weight of prepared star-shaped nylon 6 was determined by end group titration, and mechanical properties and rheological behavior were also investigated.Compared with linear chain nylon 6 with similar molecular weight,the tensile and bending strength of star-shaped nylon 6 can be maintained,impact strength retention over 75%,elongation at break decreases by 15% maximally,relative viscosity reduces 25%,melting index increases nearly 4 times,balance torque reduces 75%.The prepared star-shaped nylon 6 presents good flow ability.%以2,2,6,6-四丙酸环己酮为四官能团核心,进行己内酰胺的水解开环聚合,合成了四种不同臂长的四臂星型尼龙6,对产物的分子量进行了测定,并对其力学性能和流变行为进行了研究。结果表明,四臂星型尼龙6的分子量随着四丙酸环己酮含量的提高而降低,与相应分子量的线型尼龙6相比,星型尼龙6的拉伸强度和弯曲强度基本保持,冲击强度保持率在75%以上,断裂伸长率最大降低了15%,相对黏度降低了近25%,熔融指数提高了近4倍,平衡转矩降低了75%,表现出了较好的加工流动性。

  8. Coating individual single-walled carbon nanotubes with nylon 6,10 through emulsion polymerization.

    Science.gov (United States)

    Chen, Wei-Chiang; Wang, Randy K; Ziegler, Kirk J

    2009-08-01

    Solvent microenvironments are formed around individual single-walled carbon nanotubes (SWNTs) by mixing SWNT suspensions with water-immiscible organic solvents. These microenvironments are used to encapsulate the SWNTs with the monomer sebacoyl chloride. Hexamethylene diamine is then injected into the aqueous phase so the formation of nylon 6,10 is restricted to the interface between the microenvironment and water. This emulsion polymerization process results in uniform coatings of nylon 6,10 around individual SWNTs. The nylon-coated SWNTs remain dispersed in the aqueous phase and are highly luminescent at pH values ranging from 3 to 12. This emulsion polymerization method provides a general approach to coat nanotubes with various polymers.

  9. Processing of Micro and Nanofibers of Polypyrrole/Polyethylene Oxide/Nylon-6 by the Technique of Electrospinning

    Directory of Open Access Journals (Sweden)

    Olvera-Gracia Manuel

    2013-10-01

    Full Text Available Micro and nano-fibers from polymers in solution can be easily obtained by using the so called electrospinning technique. The principle of this technique relies on apply- ing a positive voltage to the polymer solution and a negative voltage to a collector. By increasing voltage, the surface tension will be overcome and will eject some kind of fiber deposited on the collector. The continuous fibers production will be formed like a membrane. The fibers provide a large surface area due to their small diameter, therefore, their application is considered of commercial and scientific interest. In this study, fibers from a solution made of nylon-6, polyethylene oxide and polypyrrole were obtained. Chloroform and formic acid were used as solvents for these polymers. The fibers obtained were characterized by scanning electron microscopy, FT-IR spectroscopy, X-ray diffraction and electrical conductivity. These results indicate that the diameters of the composite fibers are on the micro and nanometric range, and the conductivity thereof is that of a semiconductor material.

  10. Morfologia de nanocompósitos de polietileno e poliamida-6 contendo argila nacional Morphology study of polyethylene and nylon 6 nanocomposites containing national clay

    Directory of Open Access Journals (Sweden)

    Renata Barbosa

    2006-01-01

    Full Text Available Nanocompósitos de polietileno de alta densidade e poliamida-6 com argila bentonita nacional foram preparados por meio do processo de intercalação por fusão. Para a modificação da argila foram utilizados tipos diferentes de sais quaternários de amônio visando sintetizar as argilas organofílicas. As argilas não modificada e modificada com os sais foram incorporadas nas matrizes poliméricas, sendo que foram utilizados procedimentos diferentes para a modificação das argilas: para os nanocompósitos de polietileno, a argila foi preparada com quatro sais quaternários de amônio e para os nanocompósitos de poliamida-6 foi utilizado um único tipo de sal quaternário de amônio, variando-se seus teores para a organofilização da argila. O objetivo desse trabalho foi obter nanocompósitos de polietileno e poliamida-6 e caracterizá-los por microscopia eletrônica de transmissão (MET e por difração de raios X (DRX. Os resultados indicaram que os sistemas polietileno/argila organofílica apresentaram estruturas de nanocompósitos intercalados e/ou parcialmente esfoliados. Já os sistemas poliamida-6/argila organofílica apresentaram uma morfologia esfoliada com uma predominância de partículas de argilas dispersas na matriz.High density polyethylene and nylon 6 nanocomposites with national bentonite clay were prepared with the melt intercalation technique. Different quaternary ammonium salts were used to obtain the organoclays. The unmodified and modified clays with the salts were incorporated in the polymer matrices and different procedures were used for the modification of clays: for the polyethylene nanocomposites, the clay was prepared with four quaternary ammonium salts and for the nylon 6 nanocomposites only one type of quaternary ammonium salt was used, which had its contents varied in the organophilization of the clay. The objective of this work was to obtain polyethylene and nylon 6 nanocomposites. They were characterized by

  11. Ab initio calculation of the crystalline structure and IR spectrum of polymers: nylon 6 polymorphs.

    Science.gov (United States)

    Quarti, Claudio; Milani, Alberto; Civalleri, Bartolomeo; Orlando, Roberto; Castiglioni, Chiara

    2012-07-19

    State-of-the-art computational methods in solid-state chemistry were applied to predict the structural and spectroscopic properties of the α and γ crystalline polymorphs of nylon 6. Density functional theory calculations augmented with an empirical dispersion correction (DFT-D) were used for the optimization of the two different crystal structures and of the isolated chains, characterized by a different regular conformation and described as one-dimensional infinite chains. The structural parameters of both crystalline polymorphs were correctly predicted, and new insight into the interplay of conformational effects, hydrogen bonding, and van der Waals interactions in affecting the properties of the crystal structures of polyamides was obtained. The calculated infrared spectra were compared to experimental data; based on computed vibrational eigenvectors, assignment of the infrared absorptions of the two nylon 6 polymorphs was carried out and critically analyzed in light of previous investigations. On the basis of a comparison of the computed and experimental IR spectra, a set of marker bands was identified and proposed as a tool for detecting and quantifying the presence of a given polymorph in a real sample: several marker bands employed in the past were confirmed, whereas some of the previous assignments are criticized. In addition, some new marker bands are proposed. The results obtained demonstrate that accurate computational techniques are now affordable for polymers characterization, opening the way to several applications of ab initio modeling to the study of many families of polymeric materials.

  12. Eco-Friendly Disperse Dyeing and Functional Finishing of Nylon 6 Using Supercritical Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Tarek Abou Elmaaty

    2015-08-01

    Full Text Available In this work, a supercritical carbon dioxide assembly was successfully constructed for dyeing Nylon6 fabric. Primary experiments were carried out to confirm the possibility of bringing the dyeing up to factory scale. A series of disperse azo dyes with potential antibacterial activity were applied to dye the fabric under our study in supercritical carbon dioxide (scCO2. The factors affecting the dyeing conditions (i.e., dye concentration, time, temperature and pressure and functional properties were discussed and compared with those in aqueous dyeing. The comparison revealed that elimination of auxiliary chemicals such as salt, carrier or dispersing agent has no diverse effect on dyeing. The color strength of the dyed fabric evaluated by using K/S measurements increased by increasing dye concentration from 2% to 6% owf. (on weight of fabric. The nylon6 fabrics dyed in supercritical carbon dioxide have good fastness properties, and especially light fastness compared with conventional exhaustion dyeing. Antibacterial activity of the dyed samples under supercritical conditions was evaluated and the results showed excellent antibacterial efficiency.

  13. A Combined System for Biological Removal of Nitrogen and Carbon from Nylon-6 Production Wastewater

    Institute of Scientific and Technical Information of China (English)

    LIU Fang; LIU Guo-hua; TIAN Qing; ZHANG Man; CHEN Ji-hua

    2007-01-01

    A combined system consisting of hydrolysisacidification, denitrification and nitrification reactors wasused to remove carbon and nitrogen from the nylon - 6production wastewater, which was characterized by goodbiodegradability and high nitrogen concentration. Theinfluences of Chemical Oxygen Demand(COD) in theinfluent, recirculation ratio, Hydraulic Residence Time(HRT) and Dissolved Oxygen(DO) concentration on thesystem performances were investigated. From results itcould be seen that good performances have been achievedduring the overall experiments periods, and COD, TotalNitrogen(TN), NH+-N and Suspended Solids(SS) in theeffluent were 53, 16, 2 and 24 mg·L-1, respectively,which has satisfied the first standard of wastewaterdischarge established by Environmental Protection Agency(EPA) of China. Furthermore, results showed thatoperation factors, viz. COD in the influent, recirculationratio, HRT and DO concentration, all had importantinfluences on the system performances.

  14. Analysis of migrants from nylon 6 packaging films into boiling water.

    Science.gov (United States)

    Barkby, C T; Lawson, G

    1993-01-01

    Ultra-violet spectrophotometry (UV), high performance liquid chromatography (HPLC) and liquid chromatography coupled to mass spectroscopy (LC-MS) were used to identify and quantify oligomers extracted with boiling water from two different nylon 6 films used in boil-in-bag food packaging. The results indicated the loss of up to 1.5% of the original nylon film weight, into the boiling water, as caprolactam and cyclic oligomers up to the nonamer. Extraction time, thickness and type of film used, were found to be parameters which affected the levels of these migrants. These results will be relevant to situations in which food is cooked in the water used to heat the pouch contents.

  15. Facile Solventless Synthesis of a Nylon-6,6/Silver Nanoparticles Composite and Its XPS Study

    Directory of Open Access Journals (Sweden)

    Raúl A. Morales-Luckie

    2013-01-01

    Full Text Available Silver nanoparticles were synthesized and supported on thin nylon membranes by means of a simple method of impregnation and chemical reduction of Ag ions at ambient conditions. Particles of less than 10 nm were obtained using this methodology, in which the nylon fibers behave as constrained nanoreactors. Pores on nylon fibres along with oxygen and nitrogen from amide moieties in nylon provide effective sites for in situ reduction of silver ions and for the formation and stabilization of Ag nanoparticles. Transmission electron microscopy (TEM analysis showed that silver nanoparticles are well dispersed throughout the nylon fibers. Furthermore, an interaction between nitrogen of amides moieties of nylon-6,6 and silver nanoparticles has been found by X-ray photoelectron spectroscopy (XPS.

  16. Fiber Reinforcement in Injection Molded Nylon 6/6 Spur Gears

    Science.gov (United States)

    Senthilvelan, S.; Gnanamoorthy, R.

    2006-07-01

    Injection molded polymer composite gears are being used in many power and or motion transmission applications. In order to widen the utilization of reinforced polymers for precision motion transmission and noise less applications, the accuracy of molded gears should be increased. Since the injection molded gear accuracy is significantly influenced by the material shrinkage behaviour, there is a need to understand the influence of fiber orientation and gate location on part shrinkage behaviour and hence the gear accuracy. Unreinforced and 20% short glass fiber reinforced Nylon 6/6 spur gears were injection molded in the laboratory and computer aided simulations of gear manufacturing was also carried out. Results of the mold flow simulation of gear manufacturing were correlated with the actual fiber orientation and measured major geometrical parameters of the molded gears. Actual orientation of the fibers near the tooth profile, weld line region and injection points of molded gears were observed using optical microscope and correlated with predicted fiber orientation.

  17. Chemical engineering of the single-walled carbon nanotube-nylon 6 interface.

    Science.gov (United States)

    Gao, Junbo; Zhao, Bin; Itkis, Mikhail E; Bekyarova, Elena; Hu, Hui; Kranak, Verina; Yu, Aiping; Haddon, Robert C

    2006-06-14

    We report an approach to the chemical engineering of the single-walled carbon nanotube (SWNT)-polymer interfacial interaction in a nylon 6 graft copolymer composite which is based on the degree of SWNT functionality. Continuous fibers are drawn from composites fabricated from the in situ polymerization of caprolactam with SWNTs possessing a range of carboxylic acid (SWNT-COOH) and amide (SWNT-CONH(2)) functionalities. Mechanical performance evaluation of the composite fibers shows that a high concentration of the carboxylic acid functional groups leads to a stronger SWNT-nylon interfacial interaction, as reflected in greater values of the Young's modulus and mechanical strength. Replacement of the COOH group by CONH(2) in the SWNT starting material changes the grafting polymerization chemistry, thereby leading to the covalent attachment of longer graft copolymer chains to the SWNTs, and alters the composite morphology while increasing the composite flexibility and toughness.

  18. Novel melt-processable nylon-6/inorganic fullerene-like WS{sub 2} nanocomposites: Complex isothermal crystallization kinetics and melting behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Naffakh, Mohammed, E-mail: mnaffakh@ictp.csic.es [Departamento de Fisica e Ingenieria de Polimeros, Instituto de Ciencia y Tecnologia de Polimeros, CSIC, c/Juan de la Cierva, 3, 28006 Madrid (Spain); Marco, Carlos; Gomez, Marian A. [Departamento de Fisica e Ingenieria de Polimeros, Instituto de Ciencia y Tecnologia de Polimeros, CSIC, c/Juan de la Cierva, 3, 28006 Madrid (Spain); Jimenez, Ignacio [Instituto de Ciencia de Materiales de Madrid, CSIC, Campus de Cantoblanco, 28049 Madrid (Spain)

    2011-07-15

    Highlights: {yields} Environmentally friendly IF-WS{sub 2} is used to produce advanced nylon-6 NCPs. {yields} Melt-processable nylon-6 NCPs are obtained without using modifiers or surfactants. {yields} Novel IF-WS{sub 2} remarkably influences the nucleation and growth processes of nylon-6. {yields} High nucleating efficiency of IF-WS{sub 2} is observed for high-temperature {alpha}'-phase. {yields} New insights into crystallization and melting behaviour of nylon-6 in NCPs. - Abstract: Environmentally friendly inorganic fullerene-like tungsten disulfide nanoparticles (IF-WS{sub 2}) were used to produce new nylon-6 nanocomposites. In the nucleation-controlled regime, the crystallization rates for the nanocomposites are significantly faster than that for the neat nylon-6 as confirmed by DSC and X-ray diffraction techniques using synchrotron radiation. This fact was related to the high nucleation efficiency of IF-WS{sub 2} nanoparticles on the {alpha}'-form crystals of nylon-6. Other parameters such as the Avrami exponent, the equilibrium melting temperature, long period and the fold surface free energy of nylon-6 chains in the nanocomposites were obtained from the calorimetric data in order to determine the effect of the nanoparticles on them. The addition of IF-WS{sub 2} remarkably influences the energetics and kinetics of nucleation and growth of nylon-6 with a decrease in the fold surface free energy of 36-51%.

  19. The Cyclohexanol Cycle and Synthesis of Nylon 6,6: Green Chemistry in the Undergraduate Organic Laboratory

    Science.gov (United States)

    Dintzner, Matthew R.; Kinzie, Charles R.; Pulkrabek, Kimberly; Arena, Anthony F.

    2012-01-01

    A one-term synthesis project that incorporates many of the principles of green chemistry is presented for the undergraduate organic laboratory. In this multistep scheme of reactions, students react, recycle, and ultimately convert cyclohexanol to nylon 6,6. The individual reactions in the project employ environmentally friendly methodologies, and…

  20. The Cyclohexanol Cycle and Synthesis of Nylon 6,6: Green Chemistry in the Undergraduate Organic Laboratory

    Science.gov (United States)

    Dintzner, Matthew R.; Kinzie, Charles R.; Pulkrabek, Kimberly; Arena, Anthony F.

    2012-01-01

    A one-term synthesis project that incorporates many of the principles of green chemistry is presented for the undergraduate organic laboratory. In this multistep scheme of reactions, students react, recycle, and ultimately convert cyclohexanol to nylon 6,6. The individual reactions in the project employ environmentally friendly methodologies, and…

  1. Low temperature platinum atomic layer deposition on nylon-6 for highly conductive and catalytic fiber mats

    Energy Technology Data Exchange (ETDEWEB)

    Mundy, J. Zachary; Shafiefarhood, Arya; Li, Fanxing; Khan, Saad A.; Parsons, Gregory N., E-mail: gnp@ncsu.edu [Department of Chemical and Biomolecular Engineering, North Carolina State University, Engineering Building I, 911 Partners Way, Raleigh, North Carolina 27695-7905 (United States)

    2016-01-15

    Low temperature platinum atomic layer deposition (Pt-ALD) via (methylcyclopentadienyl)trimethyl platinum and ozone (O{sub 3}) is used to produce highly conductive nonwoven nylon-6 (polyamide-6, PA-6) fiber mats, having effective conductivities as high as ∼5500–6000 S/cm with only a 6% fractional increase in mass. The authors show that an alumina ALD nucleation layer deposited at high temperature is required to promote Pt film nucleation and growth on the polymeric substrate. Fractional mass gain scales linearly with Pt-ALD cycle number while effective conductivity exhibits a nonlinear trend with cycle number, corresponding to film coalescence. Field-emission scanning electron microscopy reveals island growth mode of the Pt film at low cycle number with a coalesced film observed after 200 cycles. The metallic coating also exhibits exceptional resistance to mechanical flexing, maintaining up to 93% of unstressed conductivity after bending around cylinders with radii as small as 0.3 cm. Catalytic activity of the as-deposited Pt film is demonstrated via carbon monoxide oxidation to carbon dioxide. This novel low temperature processing allows for the inclusion of highly conductive catalytic material on a number of temperature-sensitive substrates with minimal mass gain for use in such areas as smart textiles and flexible electronics.

  2. Highly conductive and flexible nylon-6 nonwoven fiber mats formed using tungsten atomic layer deposition.

    Science.gov (United States)

    Kalanyan, Berç; Oldham, Christopher J; Sweet, William J; Parsons, Gregory N

    2013-06-12

    Low-temperature vapor-phase tungsten atomic layer deposition (ALD) using WF6 and dilute silane (SiH4, 2% in Ar) can yield highly conductive coatings on nylon-6 microfiber mats, producing flexible and supple nonwovens with conductivity of ∼1000 S/cm. We find that an alumina nucleation layer, reactant exposure, and deposition temperature all influence the rate of W mass uptake on 3D fibers, and film growth rate is calibrated using high surface area anodic aluminum oxide. Transmission electron microscopy (TEM) reveals highly conformal tungsten coatings on nylon fibers with complex "winged" cross-section. Using reactant gas "hold" sequences during the ALD process, we conclude that reactant species can transport readily to reactive sites throughout the fiber mat, consistent with conformal uniform coverage observed by TEM. The conductivity of 1000 S/cm for the W-coated nylon is much larger than found in other conductive nonwovens. We also find that the nylon mats maintain 90% of their conductivity after being flexed around cylinders with radii as small as 0.3 cm. Metal ALD coatings on nonwovens make possible the solvent-free functionalization of textiles for electronic applications.

  3. STUDY ON THE MECHANISM OF NYLON 6,6 DISSOLVING PROCESS USING CaCl2/MeOH AS THE SOLVENT

    Institute of Scientific and Technical Information of China (English)

    SUN Benhui

    1994-01-01

    A discussion of the mechanism of nylon 6,6 dissolving process using CaCl2/MeOH as the solvent is presented. The calcium chloride forms a complex compound with nylon6,6 by breaking the hydrogen bonds. The melting point of the CaCl2-nylon 6,6 complex was found to be reduced by 91K relative to the pure nylon 6,6 polymer. The role of methanol is somewhat similar to a catalyst. The results demonstrate that the complexation of a Lewis acid (CaCl2) and a Lewis base (nylon 6, 6) can be used to probe intermolecular interactions such as hydrogen bonding in polymers, to modify the polymer properties and mediate its solubility and processing.

  4. High-level conversion of L-lysine into 5-aminovalerate that can be used for nylon 6,5 synthesis.

    Science.gov (United States)

    Park, Si Jae; Oh, Young Hoon; Noh, Won; Kim, Hye Young; Shin, Jae Ho; Lee, Eun Gyo; Lee, Seungwoon; David, Yokimiko; Baylon, Mary Grace; Song, Bong Keun; Jegal, Jonggeon; Lee, Sang Yup; Lee, Seung Hwan

    2014-10-01

    L-Lysine is a potential feedstock for the production of bio-based precursors for engineering plastics. In this study, we developed a microbial process for high-level conversion of L-lysine into 5-aminovalerate (5AVA) that can be used as a monomer in nylon 6,5 synthesis. Recombinant Escherichia coli WL3110 strain expressing Pseudomonas putida delta-aminovaleramidase (DavA) and lysine 2-monooxygenase (DavB) was grown to high density in fed-batch culture and used as a whole cell catalyst. High-density E. coli WL3110 expressing DavAB, grown to an optical density at 600 nm (OD600 ) of 30, yielded 36.51 g/L 5AVA from 60 g/L L-lysine in 24 h. Doubling the cell density of E. coli WL3110 improved the conversion yield to 47.96 g/L 5AVA from 60 g/L of L-lysine in 24 h. 5AVA production was further improved by doubling the L-lysine concentration from 60 to 120 g/L. The highest 5AVA titer (90.59 g/L; molar yield 0.942) was obtained from 120 g/L L-lysine by E. coli WL3110 cells grown to OD600 of 60. Finally, nylon 6,5 was synthesized by bulk polymerization of ϵ-caprolactam and δ-valerolactam prepared from microbially synthesized 5AVA. The hybrid system demonstrated here has promising possibilities for application in the development of industrial bio-nylon production processes.

  5. Near-infrared (NIR) monitoring of Nylon 6 during quenching studied by projection two-dimensional (2D) correlation spectroscopy

    Science.gov (United States)

    Shinzawa, Hideyuki; Mizukado, Junji

    2016-11-01

    Evolutionary change in supermolecular structure of Nylon 6 during its melt-quenched process was studied by Near-infrared (NIR) spectroscopy. Time-resolved NIR spectra was measured by taking the advantage of high-speed NIR monitoring based on an acousto-optic tunable filter (AOTF). Fine spectral features associated with the variation of crystalline and amorphous structure occurring in relatively short time scale were readily captured. For example, synchronous and asynchronous 2D correlation spectra reveal the initial decrease in the contribution of the NIR band at 1485 nm due to the amorphous structure, predominantly existing in the melt Nylon 6. This is then followed by the emerging contribution of the band intensity at 1535 nm associated with the crystalline structure. Consequently, the results clearly demonstrate a definite advantage of the high-speed NIR monitoring for analyzing fleeting phenomena.

  6. Utilization of Magnesium Hydroxide Produced by Magnesia Hydration as Fire Retardant for Nylon 6-6,6

    Directory of Open Access Journals (Sweden)

    Rocha Sônia D.F.

    2001-01-01

    Full Text Available The present work investigates the use of magnesium hydroxide, produced by magnesia hydration, as a fire retardant in polymers. The hydration was carried out in an autoclave, at temperature of 130°C for 1 hour, and the product was further submitted to cominution in a jet mill. The solids were characterized with regard to their chemical composition, particle size distribution, surface area and morphology. The performance evaluation of the hydroxide as a flame retardant for a copolymer of nylon 6-6,6 was carried out according to the UL94 specifications for vertical burning tests. V-0 flammability rating at 1.6 mm (60% magnesium hydroxide-filled nylon composite and at 3.2 mm (40% magnesium hydroxide filled nylon composite were achieved. Mechanical properties were maintained at the desired values. These results indicate that the hydroxide obtained from magnesia hydration can be successfully employed as a fire retardant for nylon 6-6,6.

  7. EFFECTS OF INTERPARTICLE DISTANCE,TEMPERATURE AND INTERFACIAL ADHESION ON BRITTLE-DUCTILE TRANSITION FOR NYLON 6/ABS BLENDS

    Institute of Scientific and Technical Information of China (English)

    Shu-hao Qin; Jie Yu; Min He; Wei Yan

    2009-01-01

    The toughness of blends composed of nylon 6 and acrylonitrile-butadiene-styrene(ABS)compatibilized by using styrene-maleic anhydride(SMA)as a compatibilizer was measured over a wide temperature region.Results reveal that the combining effects of particle size and volume fraction of ABS on the toughness of nylon 6/ABS/SMA blends can be described through plotting brittle-ductile transition of the impact strength versus the interparticle distance(ID)on the assumption that ABS domains relieve the triaxial tension via internal cavitation or interfacial debonding.Moreover,the effect of interfacial adhesion on fracture behavior of nylon 6/ABS/SMA blends strongly depends upon the testing temperature.The difference of relation amomg temperature,fracture behavior and interfacial adhesion can be understood in terms of the deformation mechanisms,i.e.in the case of poor interfacial adhesion,the toughness lies on whether debonding existing at the interface relieves triaxial tension or not.It is believed that for good interfacial adhesion,internal cavitation followed by matrix shear yielding is a predominant factor for toughening.Furthermore,the fracture surface of these blends was probed to elucidate how interfacial adhesion affected the impact strength of the blends.

  8. A comprehensive study of woven carbon fiber-reinforced nylon 6 composites

    Science.gov (United States)

    Pillay, Selvum

    Liquid molding of thermoset composites has become very popular in all industry sectors, including aerospace, automotive, mass transit, and sporting goods, but the cost of materials and processing has limited the use to high-end applications. Thermoplastic composites are relatively cheap; however, the use has been limited to components with short fiber reinforcing. The high melt viscosity and short processing window precludes their use in the liquid molding of large structures and applications with continuous fiber reinforcement. The current research addresses the processing parameters, methodology, and limitations of vacuum assisted resin transfer molding (VARTM) of carbon fabric-reinforced, thermoplastic polyamide 6 (PA6). The material used is casting grade PA6. The process developed for using VARTM to produce carbon fabric-reinforced PA6 composites is explained in detail. The effects of infusion temperature and flow distance on the fiber weight fraction and crystallinity of the PA6 resin are presented. The degree of conversion from monomer to polymer was determined. Microscopic studies to show the wet-out of the fibers at the filament level are also presented. Tensile, flexural, short beam shear strength (SBSS), and low-velocity impact test results are presented and compared to a equivalent thermoset matrix composite. The rubber toughened epoxy system (SC-15) was chosen for the comparative study because the system has been especially developed to overcome the brittle nature of epoxy composites. The environmental effects of moisture and ultraviolet (UV) radiation on the carbon/nylon 6 composite were investigated. The samples were immersed in boiling water for 100 hr, and mechanical tests were conducted. Results showed that moisture causes plasticization of the matrix and attacks the fiber matrix interface. This leads to deterioration of the mechanical properties. The samples were also exposed to UV for up to 600 hr, and post exposure tests were conducted. The

  9. Recent Advances in Nylon 6/Polypropylene Blends%尼龙6/聚丙烯共混体系研究进展

    Institute of Scientific and Technical Information of China (English)

    刘长生

    2001-01-01

    制备性能优良的尼龙6/聚丙烯(PA6/PP)共混物,需要解决的关键问题是PP在PA6树脂中的分散及界面相容性。近年来,PA6/PP相容性研究主要是引入第三组分作共混物的增容剂。综述了PA6/PP共混物的最新研究及发展趋势。%The latest studies on modifications of nylon 6 by blending with polypropylene were reviewed.The chemical reaction between compatibilizer and nylon 6 during blending and effect of compatibilizers on structure and properties of nylon 6/polypropylene blends were systematically discussed.The further studies on modification of nylon 6 by blending with polypropylene were also proposed.

  10. Electron-Beam Irradiation Effect on Thermal and Mechanical Properties of Nylon-6 Nanocomposite Fibers Infused with Diamond and Diamond Coated Carbon Nanotubes

    Science.gov (United States)

    Imam, Muhammad A.; Jeelani, Shaik; Rangari, Vijaya K.; Gome, Michelle G.; Moura, Esperidiana. A. B.

    2016-02-01

    Nylon-6 is an engineering plastic with excellent properties and processability, which are essential in several industrial applications. The addition of filler such as diamond (DN) and diamond coated carbon nanotubes (CNTs) to form molded composites may increase the range of Nylon-6 applications due to the resulting increase in strength. The effects of electron-beam irradiation on these thermoplastic nanocomposites are either increase in the cross-linking or causes chain scission. In this study, DN-coated CNTs were synthesized using the sonochemical technique in the presence of cationic surfactant cetyltrimethyl ammonium bromide (CTAB). The DN-coated CNTs nanoparticles and diamond nanoparticles were then introduced into Nylon-6 polymer through a melt extrusion process to form nanocomposite fibers. They were further tested for their mechanical (Tensile) and thermal properties (thermogravimetric analysis (TGA), differential scanning calorimetry (DSC)). These composites were further exposed to the electron-beam (160kGy, 132kGy and 99kGy) irradiation using a 1.5MeV electron-beam accelerator, at room temperature, in the presence of air and tested for their thermal and mechanical properties. The best ultimate tensile strength was found to be 690MPa and 864MPa irradiated at 132 for DN/CNTs/Nylon-6 and Diamond/Nylon-6 nanocomposite fiber as compared to 346MPa and 321MPa for DN/CNTs/Nylon-6 and Diamond/Nylon-6 nanocomposite fiber without irradiation. The neat Nylon-6 tensile strength was 240MPa. These results are consistent with the activation energy calculated from TGA graphs. DSC analysis result shows that the slight increase in glass transition temperature (Tg) and decrease in melting temperature (Tm) which was expected from high electron-beam radiation dose.

  11. Expression, purification and immobilization of the intracellular invertase INVA, from Zymomonas mobilis on crystalline cellulose and Nylon-6.

    Science.gov (United States)

    de Los Angeles Calixto-Romo, María; Santiago-Hernández, José Alejandro; Vallejo-Becerra, Vanessa; Amaya-Delgado, Lorena; del Carmen Montes-Horcasitas, María; Hidalgo-Lara, María Eugenia

    2008-11-01

    This paper presents two immobilization methods for the intracellular invertase (INVA), from Zymomonas mobilis. In the first method, a chimeric protein containing the invertase INVA, fused through its C-terminus to CBDCex from Cellulomonas fimi was expressed in Escherichia coli strain BL21 (DE3). INVA was purified and immobilized on crystalline cellulose (Avicel) by means of affinity, in a single step. No changes were detected in optimal pH and temperature when INVA-CBD was immobilized on Avicel, where values of 5.5 and 30 degrees C, respectively, were registered. The kinetic parameters of the INVA-CBD fusion protein were determined in both its free form and when immobilized on Avicel. Km and Vmax were affected with immobilization, since both showed an increase of up to threefold. Additionally, we found that subsequent to immobilization, the INVA-CBD fusion protein was 39% more susceptible to substrate inhibition than INVA-CBD in its free form. The second method of immobilization was achieved by the expression of a 6xHis-tagged invertase purified on Ni-NTA resin, which was then immobilized on Nylon-6 by covalent binding. An optimal pH of 5.5 and a temperature of 30 degrees C were maintained, subsequent to immobilization on Nylon-6 as well as with immobilization on crystalline cellulose. The kinetic parameters relating to Vmax increased up to 5.7-fold, following immobilization, whereas Km increased up to 1.7-fold. The two methods were compared showing that when invertase was immobilized on Nylon-6, its activity was 1.9 times that when immobilized on cellulose for substrate concentrations ranging from 30 to 390 mM of sucrose.

  12. cis,cis-Muconic acid: separation and catalysis to bio-adipic acid for nylon-6,6 polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Vardon, Derek R.; Rorrer, Nicholas A.; Salvachúa, Davinia; Settle, Amy E.; Johnson, Christopher W.; Menart, Martin J.; Cleveland, Nicholas S.; Ciesielski, Peter N.; Steirer, K. Xerxes; Dorgan, John R.; Beckham, Gregg T.

    2016-01-01

    cis,cis-Muconic acid is a polyunsaturated dicarboxylic acid that can be produced renewably via the biological conversion of sugars and lignin-derived aromatic compounds. Subsequently, muconic acid can be catalytically converted to adipic acid -- the most commercially significant dicarboxylic acid manufactured from petroleum. Nylon-6,6 is the major industrial application for adipic acid, consuming 85% of market demand; however, high purity adipic acid (99.8%) is required for polymer synthesis. As such, process technologies are needed to effectively separate and catalytically transform biologically derived muconic acid to adipic acid in high purity over stable catalytic materials. To that end, this study: (1) demonstrates bioreactor production of muconate at 34.5 g L-1 in an engineered strain of Pseudomonas putida KT2440, (2) examines the staged recovery of muconic acid from culture media, (3) screens platinum group metals (e.g., Pd, Pt, Rh, Ru) for activity and leaching stability on activated carbon (AC) and silica supports, (4) evaluates the time-on-stream performance of Rh/AC in a trickle bed reactor, and (5) demonstrates the polymerization of bio-adipic acid to nylon-6,6. Separation experiments confirmed AC effectively removed broth color compounds, but subsequent pH/temperature shift crystallization resulted in significant levels of Na, P, K, S and N in the crystallized product. Ethanol dissolution of muconic acid precipitated bulk salts, achieving a purity of 99.8%. Batch catalysis screening reactions determined that Rh and Pd were both highly active compared to Pt and Ru, but Pd leached significantly (1-9%) from both AC and silica supports. Testing of Rh/AC in a continuous trickle bed reactor for 100 h confirmed stable performance after 24 h, although organic adsorption resulted in reduced steady-state activity. Lastly, polymerization of bio-adipic acid with hexamethyldiamine produced nylon-6,6 with comparable properties to its petrochemical counterpart

  13. 超支化聚合物对尼龙6结晶及力学性能的影响%The Effect of Hyperbranched Polymers on the Crystalline and Mechanical Properties of Nylon 6

    Institute of Scientific and Technical Information of China (English)

    张雄; 占珊; 韩克清; 余木火

    2008-01-01

    超支化聚合物(HBP)作为共混组分加入到尼龙6(Nylon 6)基体中,有望在改善其熔体加工性能的同时提高产品性能.采用DSC、X-ray、力学测试等手段研究了不同质量分数的HBP对Nylon 6结晶性能、力学性能等的影响.结果表明:HBP的加入使得Nylon 6的结晶度有一定程度的提高,Nylon 6的晶型发生变化,γ-晶型弱化,由α-晶型占据主导地位,而且HBP在Nylon 6基体中能够均匀分散,同时提高了Nylon 6的力学性能.

  14. Nylon 6-rubber blends: 9. Crack initiation and propagation under impact conditions

    NARCIS (Netherlands)

    Dijkstra, K.; Gaymans, R.J.

    1993-01-01

    Notched specimens, composed of layers of pure nylon and layers of nylon-EPR blend, were prepared. The specimens were fractured in an Izod impact test and were also fractured in tension, with the draw speed set to give a strain rate comparable to that of the Izod impact test. The data show that at th

  15. Influence of 1D and 2D Carbon Fillers and Their Functionalisation on Crystallisation and Thermomechanical Properties of Injection Moulded Nylon 6,6 Nanocomposites

    Directory of Open Access Journals (Sweden)

    Fabiola Navarro-Pardo

    2014-01-01

    Full Text Available Carbon nanotubes (CNTs and graphene were used as reinforcing fillers in nylon 6,6 in order to obtain nanocomposites by using an injection moulding process. The two differently structured nanofillers were used in their pristine or reduced form, after oxidation treatment and after amino functionalisation. Three low nanofiller contents were employed. Crystallisation behaviour and perfection of nylon 6,6 crystals were determined by differential scanning calorimetry and wide angle X-ray diffraction, respectively. Crystallinity was slightly enhanced in most samples as the content of the nanofillers was increased. The dimensionality of the materials was found to provide different interfaces and therefore different features in the nylon 6,6 crystal growth resulting in improved crystal perfection. Dynamical, mechanical analysis showed the maximum increases provided by the two nanostructures correspond to the addition of 0.1 wt.% amino functionalised CNTs, enhancing in 30% the storage modulus and the incorporation of 0.5 wt.% of graphene oxide caused an increase of 44% in this property. The latter also provided better thermal stability when compared to pure nylon 6,6 under inert conditions. The superior properties of graphene nanocomposites were attributed to the larger surface area of the two-dimensional graphene compared to the one-dimensional CNTs.

  16. Development and validation of a nylon6 nanofibers mat-based SPE coupled with HPLC method for the determination of docetaxel in rabbit plasma and its application to the relative bioavailability study.

    Science.gov (United States)

    Xu, Qian; Zhang, Niping; Yin, Xueyan; Wang, Min; Shen, Yanyan; Xu, Shi; Zhang, Ling; Gu, Zhongze

    2010-09-15

    A simple and sensitive HPLC method was established and validated for the determination of docetaxel (DTX) in rabbit plasma. Biosamples were spiked with paclitaxel (PCX) as an internal standard (I.S.) and pre-treated by solid-phase extraction (SPE). The SPE procedure followed a simple protein digestion was based on nylon6 electrospun nanofibers mats as sorbents. Under optimized conditions, target analytes in 500 microL of plasma sample can be completely extracted by only 2.5mg nylon6 nanofibers mat and eluted by 100 microL solvent. The HPLC separation was obtained on C18 column and UV detector was used to quantify the target analytes. The extraction recovery was more than 85%; the standard curve was linear over the validated concentrations range of 10-5000 ng/mL and the limit of detection was 2 ng/mL. The inter-day coefficient of variation (CV%) of the calibration standards was below 5.0% and the mean accuracy was in the range of 92.8-113.4%. Moreover, analysing quality control plasma samples in 3 days, the results showed that the method was precise and accurate, for the intra- and inter-day CV% within 10% and the accuracy from 96.0% to 114.0%. The developed and validated method was successfully applied to relative bioavailability study for the preclinical evaluation of a new injectable DTX-sulfobutyl ether beta-cyclodextrin (DTX-SBE-beta-CD) inclusion complex freeze-dried powder (test preparation), compared with the reference preparation (DTX injection, Taxotere) in healthy rabbits. On the basis of the mean AUC(0-t) and AUC(0-infinity), the relative bioavailability of the test preparation was found to be 113.1%.

  17. Design of a "green" one-step catalytic production of epsilon-caprolactam (precursor of nylon-6).

    Science.gov (United States)

    Thomas, John Meurig; Raja, Robert

    2005-09-27

    The ever-increasing industrial demand for nylon-6 (polycaprolactam) necessitates the development of environmentally benign methods of producing its precursor, epsilon-caprolactam, from cyclohexanone. It is currently manufactured in two popular double-step processes, each of which uses highly aggressive reagents, and each generates substantial quantities of largely unwanted ammonium sulfate as by-product. Here we describe a viable laboratory-scale, single-step, solvent-free process of producing epsilon-caprolactam using a family of designed bifunctional, heterogeneous, nanoporous catalysts containing isolated acidic and redox sites, which smoothly convert cyclohexanone to epsilon-caprolactam with selectivities in the range 65-78% in air and ammonia at 80 degrees C. The catalysts are microporous (pore diameter 7.3 A) aluminophosphates in which small fractions of the Al(III)O4(5-) and P(V)O4(3-) tetrahedra constituting the 4-connected open framework are replaced by Co(III)PO4(5-) and Si(IV)O4(4-) tetrahedra, which become the loci of the redox and acidic centers, respectively. The catalysts may be further optimized, and already may be so designed as to generate selectivities of approximately 80% for the intermediate oxime, formed from NH2OH, which is produced in situ within the pore system. The advantages of such designed heterogeneous catalysts, and their application to a range of other chemical conversions, are also adumbrated.

  18. Effects of Surface Treatments on Nylon 6,6 via Non-thermal Atmospheric Plasma for Thermoplastic Adhesives

    Science.gov (United States)

    Wu, Chi-Chin; Bujanda, Andres; Demaree, John; Robinette, Jason; Weerasooriya, Amanda; Flanagan, David; ARL Plasma Group, CCEP, WMRD Team

    2015-03-01

    This work aims to modify the properties of Nylon 6,6 surfaces for attaining improved interfacial adhesion to thermoplastic composites utilizing atmospheric non-thermal plasma treatments followed by silane treatments using 3-aminopropyltriethoxysilane (APS) in some cases. An L-shaped dielectric barrier discharge configuration was employed to expose nylon substrates to oxygen-containing gas plasmas such as He/O2 and He/H2O, respectively, at room temperature. The chemically-modified surface of the substrate after plasma exposure was immediately examined by static water contact angle wettability measurements and X-ray photoelectron spectroscopy. It was found that the surface hydrophilicity was substantially enhanced and the amount of surface oxygen was significantly increased after a three-minute plasma exposure due to the increased surface energy and additional O-H bonds. The enhancements on interfacial adhesion were evaluated with lap shear tests using three types of adhesives: EPON 825/D230, EPON 825/D2000 and sikaflex252, respectively. The results of tensile tests on the adhesive joints showed an almost ~ 300% increase in interfacial adhesive strength for EPON 825/D230 bonds after plasma treatments. Finite element modeling of adhesive joints for bond strength is underway to compare with experimental results and study the quantitative relations between the mechanical properties within the bond and at interfaces.

  19. EFFECT OF THE COMPOSITION OF m-CRESOL/H2O SOLVENT ON HYDRODYNAMIC PROPERTIES OF NYLON 6

    Institute of Scientific and Technical Information of China (English)

    Musa Kaleem Baloch; Mohsan Nawaz

    2006-01-01

    The intrinsic viscosity [ η], Huggins constant (KH), [ η]0, α3 and flow activation energy values of nylon 6 have been measured in water/m-cresol (0/100-20/80) systems at different temperatures (20-60℃). It has been found that the intrinsic viscosity, [η]0 and α3 increase with the increase in water contents in m-cresol up to 15% and then decrease. They increase with the increase in temperature irrespective of solvent composition. It has been noted that the percent increase of α3 is the highest at 60℃ and the lowest at 20℃ for a particular solvent system. The intrinsic viscosity data obey Arrhenius equation over the considered conditions. The activation energy and the KH values decrease very sharply with the addition of water,giving a minimum value at 15% of water and then increase slowly. The variation of all the parameters has been explained in terms of variation in thermodynamic quality of solvent with the addition of water to m-cresol and change in temperature,resulting in the change of conformational and orientational properties of polymer molecules. This change of solvent quality also results in variation of selective sorption of solvent over the polymer, such as hydrogen bonding, etc.

  20. Preparation and Preservation of Hypoxia UW Solution

    Institute of Scientific and Technical Information of China (English)

    WAN Chidang; WANG Chunyou; LIU Tan; CHENG Rui; YANG Zhiyong

    2007-01-01

    In order to explore the method to prepare hypoxia UW solution and the stability and preservation of hypoxia UW solution, UW solution was purged by argon or air for 15 min or 60 at a flow rate of 0.8 or 2 L/min, and the oxygen partial pressure of UW solution was detected. The hy-poxia UW solution was exposed to the air or sealed up to preserve by using different methods, and the changes of oxygen partial pressure was tested. The results showed that oxygen partial pressure of 50 mL UW solution, purged by argon for 15 min at a flow rate of 2 L/min, was declined from 242±6 mmHg to 83±10 mmHg. After exposure to the air, oxygen partial pressure of hypoxia UW solution was gradually increased to 160±7 mmHg at 48 h. After sealed up by the centrifuge tube and plastic bad filled with argon, oxygen partial pressure of hypoxia UW solution was stable, about 88±13 mmHg at 72 h. It was concluded that oxygen of UW solution could be purged by argon efficiently. Sealed up by the centrifuge tube and plastic bag filled with argon, oxygen partial pressure of UW so- lution could be stabilized.

  1. 二元乙丙橡胶的环氧官能化及其增韧尼龙6的研究%TOUGHENING OF NYLON-6 WITH EPOXY-FUNCTIONALIZED ETHYLENE PROPYLENE RUBBER

    Institute of Scientific and Technical Information of China (English)

    孙树林; 徐新宇; 杨海东; 张会轩

    2005-01-01

    在双螺杆挤出机中制备了环氧官能化的二元乙丙橡胶(gEPR),采用红外光谱工作曲线法测量了EPR的接枝率.将环氧官能化的EPR与尼龙6(Nylon-6)熔融共混,并对共混体系的相形态、断裂形貌、增韧机理、力学性能进行了研究.结果表明,gEPR的环氧官能团与Nylon-6的端羧基和(或)端氨基发生了化学反应生成Nylon-6-co-EPR共聚物,该共聚物作为界面改性剂降低了Nylon-6与EPR之间的界面张力,使EPR在Nylon-6基体中均匀、稳定地分散,而且随着EPR接枝率的增加,EPR的粒径尺寸逐渐减小.断面形貌观察发现,与Nylon-6/EPR体系相比,Nyon-6/gEPR共混体系呈现明显的韧性断裂特征.通过对Nylon-6/gEPR共混体系缺口冲击形变区的研究得出EPR增韧Nylon-6的机理是橡胶粒子的空洞化和塑料基体的剪切屈服.力学性能测试表明gEPR的引入显著提高了Nylon-6的缺口冲击强度.

  2. Design of a “green” one-step catalytic production of ε-caprolactam (precursor of nylon-6)

    Science.gov (United States)

    Thomas, John Meurig; Raja, Robert

    2005-01-01

    The ever-increasing industrial demand for nylon-6 (polycaprolactam) necessitates the development of environmentally benign methods of producing its precursor, ε-caprolactam, from cyclohexanone. It is currently manufactured in two popular double-step processes, each of which uses highly aggressive reagents, and each generates substantial quantities of largely unwanted ammonium sulfate as by-product. Here we describe a viable laboratory-scale, single-step, solvent-free process of producing ε-caprolactam using a family of designed bifunctional, heterogeneous, nanoporous catalysts containing isolated acidic and redox sites, which smoothly convert cyclohexanone to ε-caprolactam with selectivities in the range 65–78% in air and ammonia at 80°C. The catalysts are microporous (pore diameter 7.3 Å) aluminophosphates in which small fractions of the \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{Al}}^{{\\mathrm{III}}}{\\mathrm{O}}_{4}^{5-}\\end{equation*}\\end{document} and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{P}}^{{\\mathrm{V}}}{\\mathrm{O}}_{4}^{3-}\\end{equation*}\\end{document} tetrahedra constituting the 4-connected open framework are replaced by \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{Co}}^{{\\mathrm{III}}}{\\mathrm{PO}}_{4}^{5-}\\end{equation*}\\end{document} and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage

  3. Solution blowing of soy protein fibers.

    Science.gov (United States)

    Sinha-Ray, S; Zhang, Y; Yarin, A L; Davis, S C; Pourdeyhimi, B

    2011-06-13

    Solution blowing of soy protein (sp)/polymer blends was used to form monolithic nanofibers. The monolithic fibers were blown from blends of soy protein and nylon-6 in formic acid. The sp/nylon-6 ratio achieved in dry monolithic nanofibers formed using solution blowing of the blend was equal to 40/60. In addition, solution blowing of core-shell nanofibers was realized with soy protein being in the core and the supporting polymer in the shell. The shells were formed from nylon-6. The sp/nylon-6 ratio achieved in dry core-shell fibers was 32/68. The nanofibers developed in the present work contain significant amounts of soy protein and hold great potential in various applications of nonwovens.

  4. HA/nylon 6,6 porous scaffolds fabricated by salt-leaching/solvent casting technique: effect of nano-sized filler content on scaffold properties

    Directory of Open Access Journals (Sweden)

    Mehrabanian M

    2011-08-01

    Full Text Available Mehran Mehrabanian1, Mojtaba Nasr-Esfahani21Member of Young Researchers Club, Najafabad Branch, Islamic Azad University, Isfahan, Iran; 2Department of Materials Science and Engineering, Najafabad Branch, Islamic Azad University, Isfahan, IranAbstract: Nanohydroxyapatite (n-HA/nylon 6,6 composite scaffolds were produced by means of the salt-leaching/solvent casting technique. NaCl with a distinct range size was used with the aim of optimizing the pore network. Composite powders with different n-HA contents (40%, 60% for scaffold fabrication were synthesized and tested. The composite scaffolds thus obtained were characterized for their microstructure, mechanical stability and strength, and bioactivity. The microstructure of the composite scaffolds possessed a well-developed interconnected porosity with approximate optimal pore size ranging from 200 to 500 µm, ideal for bone regeneration and vascularization. The mechanical properties of the composite scaffolds were evaluated by compressive strength and modulus tests, and the results confirmed their similarity to cortical bone. To characterize bioactivity, the composite scaffolds were immersed in simulated body fluid for different lengths of time and results monitored by scanning electron microscopy and energy dispersive X-ray microanalysis to determine formation of an apatite layer on the scaffold surface.Keywords: scaffold, nanohydroxyapatite, nylon 6,6, salt-leaching/solvent casting, bioactivity

  5. 锦纶6拉伸变形丝退绕性能的改善%Improvement of Unwinding Performance of Nylon 6 Draw Textured Yam

    Institute of Scientific and Technical Information of China (English)

    高原; 黎明

    2011-01-01

    The conventional nylon 6 draw textured yam(DTY) is mainly used in strap weaving industry. The knot and broken ends are increased during the unwinding process of nylon 6 DTY. With the improvement of processing parameters and machine parts, the optimum conditions such as super-feeding 3.0 %, angle of crossing 22°, package hardness 68 HS are selected for conventional 78 dtex/24 f DTY. The result showes that no broken filament, no hard twist and no spider-web filament are found during the texturizing,and unwinding rate is 1 800 m/min.%为解决锦纶6拉伸变形丝(DTY)在退绕过程中易出现打结、断头的问题,从锦纶6 DTY的加工工艺、设备部件等方面入手,确定了加工常规78dtex/24 f DTY时,在保证无毛丝、紧捻、网丝、弹性均匀的前提下,设定超喂率为3.0%,交叉角为22°,卷装硬度达到68 HS时,退绕速度可大幅提高,达到1800m/min.

  6. Preparation and evaluation of veterinary 20% injectable solution of tylosin

    OpenAIRE

    2010-01-01

    A veterinary injectable aqueous solution of the antibiotic tylosin at a concentration of 20% was prepared under aseptic conditions in dark glass bottles each containing 100 ml. The preparation was intended for animal use only. It contained 200 g tylosin tartrate, 500 ml propylene glycol, benzyl alcohol 40 ml as a preservative and water for injection up to 1000 ml. The preparation was clear yellow viscous aqueous solution free from undesired particles. The preparation complied with the require...

  7. Perfect Solutions for Wearing Preparation in India

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Presentation of KARL MAYER's reorganised warp preparation business unit during a series of symposia held in India on the 19, 21 and 23 January. KARL MAYER's Warp Preparation Section continues to focus on providing an excellent customer service, and has recently been reorganised to make it even more efficient.

  8. Perfect Solutions for Weaving Preparation in india

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Presentation of KARL MAYER’s reorganised warp preparation business unit during a series of symposia held in India on the 19,21 and 23 January. KARL MAYER’s Warp Preparation Section continues to focus on providing an excellent customer service,and has recently been reorganised to make it even more efficient.Its operations were presented during the

  9. Preparation and evaluation of veterinary 20% injectable solution of tylosin

    Directory of Open Access Journals (Sweden)

    Fouad K. Mohammad

    2010-02-01

    Full Text Available A veterinary injectable aqueous solution of the antibiotic tylosin at a concentration of 20% was prepared under aseptic conditions in dark glass bottles each containing 100 ml. The preparation was intended for animal use only. It contained 200 g tylosin tartrate, 500 ml propylene glycol, benzyl alcohol 40 ml as a preservative and water for injection up to 1000 ml. The preparation was clear yellow viscous aqueous solution free from undesired particles. The preparation complied with the requirements for injectable solutions. It was active in vitro against E. coli (JM83. The preparation of 20% tylosin solution was safe under field conditions in treating sheep and cattle suffering from pneumonia at the dose rate of 1 ml/20 kg body weight, intramuscularly/ day for 3 successive days. In conclusion, we presented the know-how of a veterinary formulation of injectable solution of 20% tylosin for clinical use in ruminants. [Vet. World 2010; 3(1.000: 5-7

  10. Influence of specific intermolecular interactions on the thermal and dielectric properties of bulk polymers: atomistic molecular dynamics simulations of Nylon 6.

    Science.gov (United States)

    Lukasheva, N V; Tolmachev, D A; Nazarychev, V M; Kenny, J M; Lyulin, S V

    2017-01-04

    Specific intermolecular interactions, in particular H-bonding, have a strong influence on the structural, thermal and relaxation characteristics of polymers. We report here the results of molecular dynamics simulations of Nylon 6 which provides an excellent example for the investigation of such an influence. To demonstrate the effect of proper accounting for H-bonding on bulk polymer properties, the AMBER99sb force field is used with two different parametrization approaches leading to two different sets of partial atomic charges. The simulations allowed the study of the thermal and dielectric properties in a wide range of temperatures and cooling rates. The feasibility of the use of the three methods for the estimation of the glass transition temperature not only from the temperature dependence of structural characteristics such as density, but also by using the electrostatic energy and dielectric constant is demonstrated. The values of glass transition temperatures obtained at different cooling rates are practically the same for the three methods. By proper accounting for partial charges in the simulations, a reasonable agreement between the results of our simulations and experimental data for the density, thermal expansion coefficient, static dielectric constant and activation energy of γ and β relaxations is obtained demonstrating the validity of the modeling approach reported.

  11. HA/nylon 6,6 porous scaffolds fabricated by salt-leaching/solvent casting technique: effect of nano-sized filler content on scaffold properties.

    Science.gov (United States)

    Mehrabanian, Mehran; Nasr-Esfahani, Mojtaba

    2011-01-01

    Nanohydroxyapatite (n-HA)/nylon 6,6 composite scaffolds were produced by means of the salt-leaching/solvent casting technique. NaCl with a distinct range size was used with the aim of optimizing the pore network. Composite powders with different n-HA contents (40%, 60%) for scaffold fabrication were synthesized and tested. The composite scaffolds thus obtained were characterized for their microstructure, mechanical stability and strength, and bioactivity. The microstructure of the composite scaffolds possessed a well-developed interconnected porosity with approximate optimal pore size ranging from 200 to 500 μm, ideal for bone regeneration and vascularization. The mechanical properties of the composite scaffolds were evaluated by compressive strength and modulus tests, and the results confirmed their similarity to cortical bone. To characterize bioactivity, the composite scaffolds were immersed in simulated body fluid for different lengths of time and results monitored by scanning electron microscopy and energy dispersive X-ray microanalysis to determine formation of an apatite layer on the scaffold surface.

  12. Development of an online preparation system for multitracer solutions

    Energy Technology Data Exchange (ETDEWEB)

    Kasamatsu, Yoshitaka [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)], E-mail: kasamatsu.yoshitaka@jaea.go.jp; Yatsukawa, Makoto; Sato, Wataru; Ninomiya, Kazuhiko; Ohki, Toshihiro; Takahashi, Naruto [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Yokoyama, Akihiko [Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa 920-1192 (Japan); Kikunaga, Hidetoshi [Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa 920-1192 (Japan); RIKEN, Wako, Saitama 351-0198 (Japan); Kinoshita, Norikazu [Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa 920-1192 (Japan); Shibata, Sadao [Nuclear Safety Technology Center, Rokkasho, Aomori 039-3212 (Japan); Shinohara, Atsushi [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2008-03-15

    We have developed a new target-irradiation system for the online preparation of multitracer solutions, where the nuclear-reaction products recoiling out of the target are directly implanted in a solvent as a liquid catcher. A rapid online transportation of the solution has enabled highly efficient recovery of the multitracer solutions having even short-lived radioactive isotopes without any chemical treatments. It has been suggested that the collection efficiency depends on the chemical properties of the recoil elements.

  13. Propriedades Mecânicas de Blendas de Nylon-6/Acrilonitrila-EPDM-Estireno (AES Compatibilizadas com Copolímero Acrílico Reativo (MMA-MA

    Directory of Open Access Journals (Sweden)

    Bassani Adriane

    2002-01-01

    Full Text Available Foram estudadas blendas de nylon-6 com copolímero de acrilonitrila/EPDM/estireno (AES utilizando, como agentes compatibilizantes, uma série de copolímeros reativos de metacrilato de metila-anidrido maleico (MMA-MA. As unidades anidrido maleico (MA, destes copolímeros, podem reagir com os grupos finais de cadeia do nylon-6. Como verificado através de reometria de torque, os copolímeros MMA-MA podem gerar copolímeros in situ na interface das blendas durante o processamento. O principal enfoque deste trabalho foi estudar os efeitos da funcionalidade e concentração dos grupos anidrido maleico do compatibilizante sobre as propriedades mecânicas das blendas. Os resultados mostraram que a incorporação dos copolímeros MMA-MA melhorou significativamente a resistência ao impacto sob entalhe das blendas nylon-6/AES. As blendas contendo copolímero MMA-MA com 1,3% em peso de MA podem ser classificadas como supertenazes e mantêm sua tenacidade em temperaturas abaixo de zero.

  14. A novel cellulose hydrogel prepared from its ionic liquid solution

    Institute of Scientific and Technical Information of China (English)

    LI Lu; LIN ZhangBi; YANG Xiao; WAN ZhenZhen; CUI ShuXun

    2009-01-01

    A novel cellulose hydrogel is prepared by regenerating cellulose from its ionic liquid solution. The transparency cellulose hydrogel presents a good chemical stability and an acceptable mechanical property. This non-toxic cellulose hydrogel should be biocompatibie and may be useful in the future as a biomaterial.

  15. Preparation and Properties of the Modified Nylon 6 Fibers%改性尼龙6纤维的制备与性能研究

    Institute of Scientific and Technical Information of China (English)

    廖和兴; 蔡芳昌; 刘志伟; 邓志; 胡萍; 叶正涛

    2011-01-01

    采用MAH-g-PE与增塑剂邻苯二甲酸二辛酯(DOP)对尼龙6进行改性制得了改性尼龙6纤维(MPA),研究了MAH-g-PE和DOP用量对MPA流变性能、热性能、热延伸及比强力性能的影响.结果表明:MPA样品流动性随着DOP含量的增加而增强,说明增塑剂对于尼龙6的增塑效果比较明显.DSC分析表明,MAH-g-PE的加入使得尼龙6熔融吸热峰峰值(T)下降,结晶度(W)增加;随MAH-g-PE含量的增加,MPA样品中原先对应于尼龙6的α晶型部分的转变为γ晶型.在最佳延伸温度120℃、DOP含量5 wt%时,MPA延伸纤维样品的比强力值达到最大.

  16. Metal Nanoparticles Preparation In Supercritical Carbon Dioxide Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Harry W. Rollins

    2004-04-01

    The novel optical, electronic, and/or magnetic properties of metal and semiconductor nanoparticles have resulted in extensive research on new methods for their preparation. An ideal preparation method would allow the particle size, size distribution, crystallinity, and particle shape to be easily controlled, and would be applicable to a wide variety of material systems. Numerous preparation methods have been reported, each with its inherent advantages and disadvantages; however, an ideal method has yet to emerge. The most widely applied methods for nanoparticle preparation include the sonochemical reduction of organometallic reagents,(1&2) the solvothermal method of Alivisatos,(3) reactions in microemulsions,(4-6) the polyol method (reduction by alcohols),(7-9) and the use of polymer and solgel materials as hosts.(10-13) In addition to these methods, there are a variety of methods that take advantage of the unique properties of a supercritical fluid.(14&15) Through simple variations of temperature and pressure, the properties of a supercritical fluid can be continuously tuned from gas-like to liquid-like without undergoing a phase change. Nanoparticle preparation methods that utilize supercritical fluids are briefly reviewed below using the following categories: Rapid Expansion of Supercritical Solutions (RESS), Reactive Supercritical Fluid Processing, and Supercritical Fluid Microemulsions. Because of its easily accessible critical temperature and pressure and environmentally benign nature, carbon dioxide is the most widely used supercritical solvent. Supercritical CO2 is unfortunately a poor solvent for many polar or ionic species, which has impeded its use in the preparation of metal and semiconductor nanoparticles. We have developed a reactive supercritical fluid processing method using supercritical carbon dioxide for the preparation of metal and metal sulfide particles and used it to prepare narrowly distributed nanoparticles of silver (Ag) and silver sulfide

  17. Exploring challenges and solutions in the preparation of surgical patients

    DEFF Research Database (Denmark)

    Møller, Thea Palsgaard; Münter, Kristine Husum; Østergaard, Doris;

    2015-01-01

    guidelines and to identify challenges and solutions for correct preparation through interactive table simulation-based workshops involving the various professions and specialties. METHODS: Firstly, specific tasks in the hospital guidelines were monitored for all surgical procedures during one week. Secondly...... management system tasks, 26% of anaesthesia record tasks, 24% of medication tasks, 14% of blood test tasks and 12% of patient record tasks. In two workshops held for each of four specialties, a total of 21 participants mapped the preoperative patient journey with related responsibilities, tasks and written...... documentation. Furthermore, challenges and suggestions for solutions were identified. CONCLUSIONS: Completion of mandatory tasks for surgical patient preparation was poor. Workshops with table simulations actively involved the stakeholders from various professions and specialties in describing the patient...

  18. Stability of urea in solution and pharmaceutical preparations.

    Science.gov (United States)

    Panyachariwat, Nattakan; Steckel, Hartwig

    2014-01-01

    The stability of urea in solution and pharmaceutical preparations was analyzed as a function of temperature (25°-60°C), pH (3.11-9.67), and initial urea concentration (2.5%-20%). This study was undertaken to (i) obtain more extensive, quantitative information relative to the degradation of urea in both aqueous and non-aqueous solutions and in pharmaceutical preparations, and (ii) test the effects of initial urea concentration, pH, buffer, and temperature values on urea degradation. The stability analysis shows that urea is more stable at the pH range of 4-8 and the stability of urea decreases by increase in temperature for all pH values. Within the experimental range of temperature and initial urea concentration values, the lowest urea degradation was found with lactate buffer pH 6.0. The urea decomposition rate in solution and pharmaceutical preparations shows the dependence of the initial urea concentrations. At higher initial urea concentrations, the rate of degradation is a decreasing function with time. This suggests that the reverse reaction is a factor in the degradation of concentrated urea solution. For non-aqueous solvents, isopropanol showed the best effort in retarding the decomposition of urea. Since the losses in urea is directly influenced by its stability at a given temperature and pH, the stability analysis of urea by the proposed model can be used to prevent the loss and optimize the operating condition for urea-containing pharmaceutical preparations.

  19. Exploring challenges and solutions in the preparation of surgical patients

    DEFF Research Database (Denmark)

    Møller, Thea Palsgaard; Münter, Kristine Husum; Østergaard, Doris;

    2015-01-01

    INTRODUCTION: Handover of surgical patients from ward to operating room is a sensible point for information and communication failures. Guidelines were developed for preparation of surgical patients. Our aim was to explore if patients are sufficiently prepared for surgery according to local......, workshops including table simulations involving the various professions and specialties were held. RESULTS: In total, 314 surgical procedures were performed of which 196 were eligible for analysis. Emergency procedures showed the poorest results with non-completed tasks comprising 58% of electronic patient...... documentation. Furthermore, challenges and suggestions for solutions were identified. CONCLUSIONS: Completion of mandatory tasks for surgical patient preparation was poor. Workshops with table simulations actively involved the stakeholders from various professions and specialties in describing the patient...

  20. PREPARATION OF MULTIFUNCTIONAL ORGANOLITHIUM INITIATOR IN CYCLOHEXANE SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    Ming Yao; Hai-yan Zhang; Xing-ying Zhang; Shu-he Zhao

    2011-01-01

    Multifunctional organolithium initiator was prepared in cyclohexane solvent. The process started with adding the cyclohexane solution of butadiene to naphthalene-lithium in batches to produce butadiene oligomer dilithium with 4-8 butadiene repeating units. In the first feeding, the maximum loading of cyclohexane and the minimum concentration of butadiene cyclohexane solution must be controlled under Vcyclohexane ≤ 1.33 VTHnF and p ≥ 40.6cN. Then, SnC14 was added and eventually the multifunctional organolithium initiator containing Sn atom was synthesized through coupling reaction.Experiment results showed that adding the cyclohexane solution in batches was effective in overcoming some difficulties,such as insolubility of naphthalene-lithium in cyclohexane, low efficiency of naphthalene-lithium in initiating butadiene. In practice, benzene can be replaced by cyclohexane completely, which can not only reduce environmental pollution from benzene, but also overcome the difficulty of solvent recovery caused by similar boiling point between benzene and cyclohexane. Prepared with multifunctional organolithium containing Sn atom as initiator, the star-shaped solution polymerized styrene-butadiene rubber (star S-SBR) with better vulcanization performances, lower rolling resistance and higher wet-skid resistance was obtained.

  1. Analysis of fluoride concentration in solutions prepared at dispensing pharmacies

    Directory of Open Access Journals (Sweden)

    Eduardo Pizzatto

    2011-07-01

    Full Text Available Introduction: Fluoride plays an important role in oral health promotion and is considered important in dental caries prevention both in children and adults. Fluoride is widely used at high-risk conditions of caries, when the use of fluoride-containing mouthwashes is recommended, considering that fluoride itself reduces the risk of dental caries. Objective: To evaluate the fluoride concentration in solutions prepared at different dispensing pharmacies in the city of Curitiba – PR, Brazil. Material and methods: The analysis of fluoride concentration was preformed through Ion Chromatography method (DIONEX. Results: The results obtained through this analysis showed that all solutions presented fluoride concentration above that required in the dentist’s prescription, varying between 5.48% and 24.02% more fluoride, at absolute concentration. Conclusion: This finding highlights the increasing risk of fluoride acute intoxication in cases of accidental ingestion of the solution.

  2. Preparation of patients submitted to thyroidectomy with oral glucose solutions.

    Science.gov (United States)

    Libiszewski, Michał; Drozda, Rafał; Smigielski, Janusz; Kuzdak, Krzysztof; Kołomecki, Krzysztof

    2012-05-01

    The AIM OF THE STUDY was to determine postoperative insulin-resistance in patients subject to total thyroidectomy, the prevalence of subjective feelings of hunger immediately before surgery, and the incidence of nausea/vomiting after surgery in patients prepared for elective operations by means of oral glucose solutions. The study group comprised 115 patients, including 71 patients prepared for surgery by means of oral glucose solutions (12.5% glucose) administered 12 and 3 hours before the procedure, at a dose of 800 and 400 ml. The control group comprised 44 patients prepared for surgery by means of the traditional manner- the last meal was served before 2pm the day before the surgical procedure, while fluids before 10pm. Considering both groups, we evaluated glucose and insulin levels three times, as well as determined the insulin-resistance ratio (HOMA-IR) 24 before, and 12 hours and 7 days after surgery. The incidence of nausea and vomiting after surgery, and the subjective feeling of hunger before surgery were also evaluated. Statistically significant differences considering insulin level and HOMA-IR values were observed during the II and III measurements. The glucose and insulin values, and the HOMA-IR insulin-resistance ratio, showed no statistically significant differences during measurement I. No statistically significant glucose level differences were observed during measurements II and III. A significantly greater subjective feeling of hunger before surgery and nausea/vomiting afterwards were observed in the control group. The preparation of patients with oral glucose solutions decreases the incidence of postoperative (thyroidectomy) insulin-resistance, and occurrence of nausea/vomiting during the postoperative period.

  3. Simulation and Control of Nylon-6 Continuous Polymerization Process%尼龙6连续聚合过程的流程模拟与调控

    Institute of Scientific and Technical Information of China (English)

    赵玲; 邢玉林; 秦春曦; 奚桢浩

    2014-01-01

    基于流程模拟软件Aspen Polymer Plus建立了己内酰胺水解聚合生产尼龙6的两段式工艺过程模型,利用该模型对某厂2万吨/年两段式生产工艺进行模拟,各聚合阶段内己内酰胺、环状二聚体含量、聚合物分子量,以及各聚合阶段温度分布和两聚合塔塔顶出水量等结果均与工业值吻合良好,模型可靠。在此基础上,进一步模拟考察了聚合反应过程中进料水含量、分子量调节剂含量、各聚合阶段温度和各聚合塔压力等因素对己内酰胺转化率、环状二聚体生成以及聚合产品分子量的影响,并进行了参数灵敏性分析。结果表明:较低的进料水含量、降低反应温度和前聚塔压力及提高后聚塔的真空度均有利于降低聚合产品中环状二聚体的含量;两个聚合塔下半段的温度变化对环状二聚体产生有显著影响,提高后聚塔真空度可显著提高聚合物分子量。以尼龙6连续聚合过程的环状二聚体含量调控为目标,在优化的操作条件下,尼龙6聚合物中环状二聚体的含量可降低约16%。%Abstrct:A model of two-steps Nylon-6 polymerization process was set up by Aspen Polymer Plus. As the simulational results fit all of the industrial operational data of 20 kt/a manufacture process well, including the composition of caprolactam and cyclic dimer, polymer molecular weight, temperature distribution, and the water yield from the top of two VK tubes, which indicated that the model was reliable. A sensitivity was analyzed by the model to evaluate the adjust ability of operational parameters, including the water and acetic acid contents in feed, temperature distribution and pressure of each VK tube in polymerization process. The results showed that low water content in feed, low reaction temperature, low pressure of the first tube and high vacuum of the secend tube contributed to less cyclic dimer fraction in polymer product. The

  4. An ignored variable: solution preparation temperature in protein crystallization.

    Science.gov (United States)

    Chen, Rui-Qing; Lu, Qin-Qin; Cheng, Qing-Di; Ao, Liang-Bo; Zhang, Chen-Yan; Hou, Hai; Liu, Yong-Ming; Li, Da-Wei; Yin, Da-Chuan

    2015-01-19

    Protein crystallization is affected by many parameters, among which certain parameters have not been well controlled. The temperature at which the protein and precipitant solutions are mixed (i.e., the ambient temperature during mixing) is such a parameter that is typically not well controlled and is often ignored. In this paper, we show that this temperature can influence protein crystallization. The experimental results showed that both higher and lower mixing temperatures can enhance the success of crystallization, which follows a parabolic curve with an increasing ambient temperature. This work illustrates that the crystallization solution preparation temperature is also an important parameter for protein crystallization. Uncontrolled or poorly controlled room temperature may yield poor reproducibility in protein crystallization.

  5. Perovskite/polymer solar cells prepared using solution process

    Science.gov (United States)

    Rosa, E. S.; Shobih; Nursam, N. M.; Saputri, D. G.

    2016-11-01

    We report a simple solution-based process to fabricate a perovskite/polymer tandem solar cell using inorganic CH3NH3PM3 as an absorber and organic PCBM (6,6 phenyl C61- butyric acid methyl ester) as an electron transport layer. The absorber solution was prepared by mixing the CH3NH3I (methyl ammonium iodide) with PbI2 (lead iodide) in DMF (N,N- dimethyl formamide) solvent. The absorber and electron transport layer were deposited by spin coating method. The electrical characteristics generated from the cell under 50 mW/cm2 at 25 °C comprised of an open circuit voltage of 0.31 V, a short circuit current density of 2.53 mA/cm2, and a power conversion efficiency of 0.42%.

  6. Titania preparation from soda roasted slag using sulfuric acid solution

    Directory of Open Access Journals (Sweden)

    El-Sayed A. Manaa

    2016-11-01

    Full Text Available This work deals with treatment of the sodium titanate cake results from roasted titania slag using 60% sulfuric acid solution. The working sample produced by roasting titania slag with NaCO3 at 850 °C. After roasting V and Cr species as impurities in the roasted sample are converted to water soluble species as NaVO3 and Na2CrO4 before acid treatment however, the insoluble sodium titanate products (NaFeTiO4, Na8Ti5O14, Na6Ti2O7 and Na2TiO4 are then subjected to H2SO4 acid dissolution. The produced sulfate solution is subjected to hydrolysis step in presence of oxalic acid as a reducing agent. The hydrolyzed precipitate after filtration and washing with H2SO4 solution and warm water is dried at 100 °C and calcinated at 850 °C to prepare high pure TiO2 (99.8% besides removing ferrous sulfate (FeSO4 as a byproduct from the sulfate solution.

  7. Preparation and characterisation of tamarind 4-hydroxybenzoic acid ...

    African Journals Online (AJOL)

    The effect of experimental parameters, such as pH, treatment time, temperature, adsorbent dose, initial metal .... solution (self-made) was a 1 000 mg/kg solution of metal ions ...... 'organic–inorganic' hybrid cation-exchanger: Nylon-6, 6, Zr (IV).

  8. Preparation of polystyrene–clay nanocomposite by solution intercalation technique

    Indian Academy of Sciences (India)

    P K Paul; S A Hussain; D Bhattacharjee; M Pal

    2013-06-01

    Polymer–clay nanocomposites of commercial polystyrene (PS) and clay laponite were prepared via solution intercalation technique. Laponite was modified suitably with the well known cationic surfactant cetyltrimethyl ammonium bromide by ion-exchange reaction to render laponite miscible with hydrophobic PS. X-ray diffraction analysis in combination with scanning electron microscopy gives an idea of structural and morphological information of PS–laponite nanocomposite for different varying organo-laponite contents. Intercalation of PS chain occurs into the interlayer spacings of laponite for low organo-laponite concentration in the PS–O-laponite mixture. However, aggregation and agglomeration occur at higher clay concentration. The molecular bond vibrational profile of laponite as well as PS–laponite nanocomposite have been explored by Fourier transform infrared spectroscopy. Thermogravimetric analysis along with differential scanning calorimetry results reveal the enhancement of both thermal stability and glass transition temperature of PS due to the incorporation of clay platelets.

  9. Effect of Nb on barium titanate prepared from citrate solutions

    Directory of Open Access Journals (Sweden)

    Stojanović Biljana D.

    2002-01-01

    Full Text Available The influence of the addition of dopants on the microstructure development and electrical properties of BaTiO3 doped with 0.2, 0.4, 0.6, 0.8 mol% of Nb and 0.01 mol% of Mn based compounds was studied. Doped barium titanate was prepared using the polymeric precursor method from citrate solutions. The powders calcined at 700°C for 4 hours were analysed by infrared (IR spectroscopy to verify the presence of carbonates, and by X-ray diffraction (XRD for phase formation. The phase composition, microstructure and dielectric properties show a strong dependence on the amount of added niobium.

  10. Characterization of PAN/ATO nanocomposites prepared by solution blending

    Indian Academy of Sciences (India)

    Wei Pan; Hantao Zou

    2008-10-01

    Conducting nanocomposites of polyacrylonitrile (PAN) and antimony-doped tin oxide (ATO) were prepared by solution blending. Electrical properties of the nanocomposites were characterized by means of electrical conductivity measurements and the phase structures were investigated via scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analyses (TGA) and dynamical mechanical analysis (DMA). This study unveiled a remarkable, interpenetrating network of chainlike nano-ATO within the PAN matrix, consistent with the existence of connected conducting paths at content as low as 4 wt% of the nano-ATO. The storage modulus of the nanocomposites increased with increasing content of ATO, due to formation of immobilized layer between polymer and filler. The interactions between ATO and PAN molecules resulted in high tan for the PAN/ATO nanocomposites. Thermal stability of the nanocomposites was found remarkably enhanced by the incorporation of nano-ATO.

  11. Effective shelf-life of prepared sodium hypochlorite solution.

    Science.gov (United States)

    Johnson, B R; Remeikis, N A

    1993-01-01

    Although the tissue solvent and bactericidal properties of sodium hypochlorite are well known, the effective shelf-life of prepared sodium hypochlorite solutions is not known. The stability of sodium hypochlorite is adversely affected by exposure to high temperature, light, air, and the presence of organic and inorganic contaminants. The purpose of this study was to investigate the variables of storage conditions and time on the tissue-dissolving capacity of three different concentrations of sodium hypochlorite. Fresh frozen human umbilical cord was used as the tissue sample for this experiment. Tissue samples were dissolved at time intervals ranging from 1 day to 10 wk in 5.25%, 2.62%, and 1.0% solutions of sodium hypochlorite. The tissue-dissolving ability of 5.25% sodium hypochlorite remains stable for at least 10 wk. The tissue-dissolving ability of 2.62% and 1.0% sodium hypochlorite remains relatively stable for 1 wk after mixing, then exhibits a significant decrease in tissue-dissolving ability at 2 wk and beyond.

  12. Lyophilization monophase solution technique for preparation of amorphous flutamide dispersions.

    Science.gov (United States)

    Elgindy, Nazik; Elkhodairy, Kadria; Molokhia, Abdallah; Elzoghby, Ahmed

    2011-07-01

    Flutamide (FLT) is a poorly soluble anticancer drug. Therefore, lyophilized dispersions (LDs) of FLT with polyvinylpyrrolidone (PVP) K30, polyethylene glycol (PEG) 6000, and pluronic F127 were prepared via lyophilization monophase solution technique with the aim of increasing its dissolution rate. FLT showed an A(L)-type phase solubility diagrams with PVP and PEG, whereas A(N)-type diagram was obtained with pluronic. The amount of residual tertiary butyl alcohol, determined by gas chromatography, was 0.015-0.021% w/w. Differential scanning calorimetry and X-ray diffractometry revealed that FLT-polymer 1:1 LDs were partially amorphous, whereas the 1:3 and 1:5 LDs were completely amorphous. After 6 months storage, polymers under study inhibited FLT recrystallization maintaining its amorphous form. The particle size of FLT-polymer LDs was between 0.81 and 2.13 μm, with a high surface area (268.43-510.82 m²/g) and porosity (354.01-676.23 e⁻³ mL/g). Also, the poor flow properties of FLT could be improved but to a limited extent. FLT dissolution was significantly enhanced with the fastest dissolution that was achieved using pluronic. After 30 min, about 66.52%, 78.23%, and 81.64% of FLT was dissolved from 1:5 FLT-PVP, PEG, and pluronic LDs, respectively, compared with only 13.45% of FLT. These data suggest that these polymers might be useful adjuncts in preparation and stabilization of amorphous immediate-release FLT LDs.

  13. Preparation and characterization of barium titanate stannate solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Horchidan, Nadejda, E-mail: NHorchidan@stoner.phys.uaic.ro [Department of Physics, ' Al. I. Cuza' University, Bv. Carol 11, Iasi 700506 (Romania); Ianculescu, Adelina C. [Department of Oxide Materials Science and Engineering, Polytechnics University, 1-7 Gh. Polizu, P.O. Box 12-134, 011061 Bucharest (Romania); Curecheriu, Lavinia P.; Tudorache, Florin [Department of Physics, ' Al. I. Cuza' University, Bv. Carol 11, Iasi 700506 (Romania); Musteata, Valentina [Institute of Macromolecular Chemistry ' Petru Poni' , Aleea Grigore Ghica Voda 41A, 700487 Iasi (Romania); Stoleriu, Stefania [Department of Oxide Materials Science and Engineering, Polytechnics University, 1-7 Gh. Polizu, P.O. Box 12-134, 011061 Bucharest (Romania); Dragan, Nicolae; Crisan, Dorel [Institute of Physical Chemistry ' Ilie Murgulescu' , Lab. of Oxide Materials Science, 202 Splaiul Independentei, 060021 Bucharest (Romania); Tascu, Sorin; Mitoseriu, Liliana [Department of Physics, ' Al. I. Cuza' University, Bv. Carol 11, Iasi 700506 (Romania)

    2011-04-07

    Research highlights: > BaSnxTi1-xO3 (x = 0; 0.05; 0.1; 0.15; 0.2) ceramics were prepared by solid state reaction and sintered at 13000C for 4h. > The phase purity, structural parameters and microstructural characteristics were investigated. > The dielectric properties were studied as function of temperature and frequency and empirical parameters {eta} and {delta} were calcutate. > The non-linear dielectric properties (tunability) of the samples were studied at room temperature. > By increasing the Sn addition, the {epsilon}(E) dependence tends to reduce its hysteresis behaviour. - Abstract: BaSn{sub x}Ti{sub 1-x}O{sub 3} (x = 0; 0.05; 0.1; 0.15; 0.2) solid solutions were prepared via conventional solid state reaction and sintered at 1300 {sup o}C for 4 h, resulting in dense single phase ceramics with homogeneous microstructures. Tetragonal symmetry for x {<=} 0.1, cubic for x = 0.2 and a superposition of tetragonal and cubic for x = 0.15 compositions were found by X-ray diffraction analysis. The temperature and frequency dependence of the complex dielectric constant and dc tunability were determined. A transformation from normal ferroelectric to relaxor with diffuse phase transition was observed with increasing the Sn concentration. All the investigated compositions show a relative tunability between 0.55 (for x = 0.2) and 0.74 (for x = 0.1), at a field amplitude of E = 20 kV/cm.

  14. Preparation of nanoparticles of Magnolia bark extract by rapid expansion from supercritical solution into aqueous solutions.

    Science.gov (United States)

    He, Shuai; Zhou, Benjie; Zhang, Shouyao; Lei, Zhengjie; Zhang, Zhongyi

    2011-01-01

    A rapid expansion from supercritical solution into aqueous solution (RESSAS) technology was presented for the micronization of Chinese medicinal material. Magnolia bark extract (MBE) obtained by supercritical carbon dioxide (scCO₂) extraction technology was chosen as the experimental material. RESSAS process produced 303.0 nm nanoparticles (size distribution, 243.6-320.5 nm), which was significantly smaller than the 55.3 µm particles (size distribution, 8.3-102.4 µm) prepared by conventional mechanical milling. The effect of process parameters, including extraction temperature (30 °C, 40 °C, 50 °C), extraction pressure (200, 250, 300 bar) and nozzle size (50, 100, 200 µm), on the size distribution of nanoparticles was investigated. The characteristics of nanoparticles and materials were also studied by scanning electron microscopy (SEM) and laser light scattering (LLS). This study demonstrates that RESSAS is applicable for preparing nanoparticles of MBE at low operating temperature; the process is simple without any residual solvent.

  15. Solution-blown nanofiber mats from fish sarcoplasmic protein

    DEFF Research Database (Denmark)

    Sett, S.; Boutrup Stephansen, Karen; Yarin, A.L.

    2016-01-01

    that the production rate of solution-blowing was increased 30-fold in relation to electrospinning. Overall, this study reveals FSP as an interesting biopolymeric alternative to synthetic polymers, and the introduction of FSP to nylon 6 provides a composite with controlled properties....

  16. Effects of cardioplegia induced by a Young's solution (YNG solution) on the blood-perfused canine papillary muscle preparation.

    Science.gov (United States)

    Satoh, H; Ohkubo, K; Suzuki, K; Katano, Y; Otorii, T; Kawada, T; Yoshida, S; Imai, S

    1984-03-01

    Experiments were carried out in the blood-perfused canine papillary muscle preparation to evaluate the protective effect of a cardioplegic solution, Young's solution (YNG solution), on the myocardial function. Both in spontaneously contracting preparations and in electrically paced (2 Hz) preparations, the time to the cardiac arrest and the time to the maximum blood flow were found to be significantly shorter when the cardiac arrest was induced with cardioplegic solutions than when it was induced with the cold modified Krebs-Ringer's solution (cold cardioplegia). The maximum blood flow of the paced preparation tended to be greater with cardioplegic solutions. The time to resumption of regular contractions was significantly shorter with YNG solution as compared with cold cardioplegia. The developed tension and the blood flow at the time of resumption of the regular contractions tended to approach the control value more quickly with YNG solution, as compared with other cardioplegic solutions and cold cardioplegia. It is concluded that YNG solution represents an optimal cardioplegic solution.

  17. Preparing for Remarriage: Anticipating the Issues, Seeking Solutions.

    Science.gov (United States)

    Ganong, Lawrence H.; Coleman, Marilyn

    1989-01-01

    Examined the ways remarried adults with children prepared for remarriage. Asked 100 men and 105 women about their methods of preparing, pre-remarriage concerns, and issues discussed prior to marriage. Primary way subjects prepared for remarriage was by cohabitation. Living together appeared to be more effective for men than for women. (Author/NB)

  18. Preparing for Remarriage: Anticipating the Issues, Seeking Solutions.

    Science.gov (United States)

    Ganong, Lawrence H.; Coleman, Marilyn

    1989-01-01

    Examined the ways remarried adults with children prepared for remarriage. Asked 100 men and 105 women about their methods of preparing, pre-remarriage concerns, and issues discussed prior to marriage. Primary way subjects prepared for remarriage was by cohabitation. Living together appeared to be more effective for men than for women. (Author/NB)

  19. Mask process matching using a model based data preparation solution

    Science.gov (United States)

    Dillon, Brian; Saib, Mohamed; Figueiro, Thiago; Petroni, Paolo; Progler, Chris; Schiavone, Patrick

    2015-10-01

    Process matching is the ability to precisely reproduce the signature of a given fabrication process while using a different one. A process signature is typically described as systematic CD variation driven by feature geometry as a function of feature size, local density or distance to neighboring structures. The interest of performing process matching is usually to address differences in the mask fabrication process without altering the signature of the mask, which is already validated by OPC models and already used in production. The need for such process matching typically arises from the expansion of the production capacity within the same or different mask fabrication facilities, from the introduction of new, perhaps more advanced, equipment to deliver same process of record masks and/or from the re-alignment of processes which have altered over time. For state-of-the-art logic and memory mask processes, such matching requirements can be well below 2nm and are expected to reduce below 1nm in near future. In this paper, a data preparation solution for process matching is presented and discussed. Instead of adapting the physical process itself, a calibrated model is used to modify the data to be exposed by the source process in order to induce the results to match the one obtained while running the target process. This strategy consists in using the differences among measurements from the source and target processes, in the calibration of a single differential model. In this approach, no information other than the metrology results is required from either process. Experimental results were obtained by matching two different processes at Photronics. The standard deviation between both processes was of 2.4nm. After applying the process matching technique, the average absolute difference between the processes was reduced to 1.0nm with a standard deviation of 1.3nm. The methods used to achieve the result will be described along with implementation considerations, to

  20. Depolymerization of Nylon 6 in Mixtures of the Ionic Liquid and Water%离子液体与水的混合体系中尼龙6的解聚反应

    Institute of Scientific and Technical Information of China (English)

    阮如意; 陈晋阳; 徐天娇

    2012-01-01

    Depolymerization of nylon6 to ε-caprolactam was carried out in the ionic liquids and water binary mixtures from 150 to 230 ℃.The products of depolymerization were analyzed by means of infrared spectroscopy,differential scanning calorimeter,liquid chromategraphy-mass spectrometry and high performance liquid chromatography.Response surface methodology(RSM),based on three-variable-three-level Box-Behnken design(BBD),was used to determine the effects of the main parameters on nylon 6 depolymerization.A express of Y(%)=43.76+6.69A+6.06B+3.60C+3.15AB+3.48AC-17.06A2-16.56B2-14.18C2 was established to determine the yield of caprolactam at different reaction temperature(A),the ILs' molar ratio(B),and reaction time(C).The optimal conditions for depolymerization was as follows: reaction temperature of 175 ℃,the molar ratio of IL 14.2%,and reaction time of 7.3 h.Under the condition,the yield of ε-caprolactam is 44.4% and the degradation rate of nylon 6 is 88.4%.%在150℃~230℃条件下,以氯化1-丁基-3-甲基咪唑离子液体与水组成的二元混合体系为介质进行尼龙6的解聚研究。固相残余物利用红外光谱和差示扫描量热仪进行分析。液相产物通过液相色谱-质谱联用仪和液相色谱进行定性与定量分析。建立了反应温度(A)、混合体系中离子液体的物质的量分数(B)以及反应时间(C)与ε-己内酰胺回收率(Y)之间的数学模型:Y(%)=43.76+6.69A+6.06B+3.60C+3.15AB+3.48AC-17.06A2-16.56B2-14.18C2,并利用响应曲面法(RSM)确定了解聚的优化工艺条件,即反应温度175℃、离子液体的物质的量分数14.2%及反应时间7.3h,此时ε-己内酰胺的回收率为44.4%、尼龙6的降解率为88.4%。

  1. Morphology, thermal and mechanical properties of PVC/MMT nanocomposites prepared by solution blending and solution blending + melt compounding

    DEFF Research Database (Denmark)

    Madaleno, Liliana Andreia Oliveira; Schjødt-Thomsen, Jan; Pinto, José Cruz

    2010-01-01

    and solution blending + melt compounding The effects on morphology, thermal and mechanical properties of the PVC/MMT nanocomposites were studied by varying the amount of Na-MMT and OMMT in both methods SEM and XRD analysis revealed that possible intercalated and exfoliated structures were obtained in all...... of the PVC/MMT nanocomposites Thermogravimetric analysis revealed that PVC/Na-MMT nanocomposites have better thermal stability than PVC/OMMT nanocomposites and PVC. In general, PVC/MMT nanocomposites prepared by solution blending + melt compounding revealed improved thermal properties compared to PVC....../MMT nanocomposites prepared by solution blending Vicar tests revealed a significant decrease in Vicar softening temperature of PVC/MMT nanocomposites prepared by solution blending + melt compounding compared to unfilled PVC The mechanical properties of the PVC/MMT nanocomposites were, in general, greatly improved...

  2. Synergistic flame retardant effects of composites containing organic montmorillonite, Nylon 6 and 2-cyclic pentaerythritoloctahydrogen tetraphosphate-4,6-benzene sulfonic acid sodium ammion-triazine%新型单组份磷-氮膨胀型阻燃剂/OMMT对尼龙6热稳定性能的影响及其协同阻燃效果

    Institute of Scientific and Technical Information of China (English)

    王超; 李迎春; 胡国胜; 曹东豪

    2015-01-01

    A novel P-N containing intumescent flame retardant, 2-cyclic pentaerythritoloctahydrogen tetraphosphate-4,6-benzene sulfonic acid sodium ammion-triazine ( CTOB) was synthesized and used as an additive in intumescent flame retardant composites containing organic montmorillonite (OMMT) and Nylon 6. The thermal stability and flammability properties of Nylon 6, CTOB, OMMT and their composites were investigated by TGA, limiting oxygen index ( LOI) and cone calorimeter tests. Synergistic effects between CTOB and OMMT in the Nylon 6/CTOB/OMM composite were observed. A combination of CTOB and OMMT improved the thermal stability and the flammability properties of Nylon 6 and increased the LOI value to 28. 0%. The average and peak heat release rates of the ternary composite were reduced by about 65. 7 and 49. 3%, respectively, compared with those of Nylon 6. The residue generated after the cone calorimeter tests upon combustion of the ternary composite was a compact and dense char as revealed by SEM, which is critically important for an excellent flame retardant.%合成出新型单组份磷-氮膨胀型阻燃剂2-环季戊四醇磷酸酯-4,6-对氨基苯磺酸钠均三嗪(CTOB),通过FT-IR,1H NMR和31 P NMR对其结构进行表征。以CTOB与有机蒙脱土( OMMT)为原料,制备出阻燃型CTOB/ OMMT/ Nylon 6复合材料。热重分析表明:CTOB和OMMT的加入能有效提高尼龙6的热稳定性能和成炭性能,通过极限氧指数( LOI)、锥形量热、垂直燃烧实验(UL-94)和TGA对CTOB/ OMMT/ Nylon 6复合材料的阻燃性能进行研究。结果表明,CTOB和 OMMT在尼龙6中表现出良好的协同阻燃效果,CTOB/OMMT/ Nylon 6的氧指数可达28.0%,垂直燃烧性能达到UL-94 V-0级,阻燃后的尼龙6其PHRR 和 THR分别下降了65.7%和49.3%。 CTOB/ OMMT/ Nylon 6燃烧后,表面可生成致密性良好的膨胀炭层,膨胀炭层的形成是有效提高Nylon 6阻燃性能的关键因素。

  3. Preparation of zein fibers using solution blow spinning method

    Science.gov (United States)

    Zein fibers were successfully fabricated via solution blow spinning (SBS) using acetic acid as solvent. Surface tension, viscosity and modulus of zein solutions were respectively determined by force tensiometer and rheometer. Increases of these properties were observed with an increase of concentrat...

  4. Preparation and Evaluation of Veterinary 0.1% Injectable Solution of Atropine Sulphate

    Directory of Open Access Journals (Sweden)

    F K Mohammad

    2012-06-01

    Full Text Available This study introduces the know-how of preparing a multiple injection form atropine sulphate solution. An injectable aqueous solution of atropine sulphate at a concentration of 0.1%. was prepared under aseptic conditions in dark glass bottles each containing 50 ml. The preparation was intended for animal use only. It contained 1g atropine sulphate, 9 g sodium chloride as a normal saline, benzyl alcohol 15 ml as a preservative and water for injection up to 1000 ml. The pH of the solution was adjusted to 4.2 (range 3.0-6.5. The preparation of 0.1% atropine sulphate solution was clear colorless solution free from undesired particles. It complied with the requirements for injectable solutions. Further, the preparation was safe when used under laboratory conditions in chicks, rats and donkeys. It was also effective in preventing dichlorvos (an organophosphate insecticide-induced poisoning in chicks in a manner comparable to a commercial preparation of 0.1% atropine sulphate. In conclusion, the know-how of a preparation of 0.1% atropine sulphate solution is presented for veterinary use. [Vet. World 2012; 5(3.000: 145-149

  5. Preparing Culturally Diverse Special Education Faculty: Challenges and Solutions

    Science.gov (United States)

    Peterson, Patricia; Showalter, Stephen

    2010-01-01

    This paper describes why more bilingual culturally responsive special education faculty are needed to meet the needs of the increasing number of culturally and linguistically diverse students with disabilities in the United States. In addition, the paper presents the successes and challenges in the journey to prepare university faculty leaders in…

  6. Preparation of fluorescent polyaniline nanoparticles in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Kleber G. B. [Universidade Federal de Pernambuco, Departamento de Engenharia Mecanica (Brazil); Melo, Etelino F. de [Universidade Federal de Pernambuco, Departamento de Quimica Fundamental (Brazil); Andrade, Cesar A. S. [Universidade Federal de Pernambuco, Departamento de Bioquimica (Brazil); Melo, Celso P. de, E-mail: celso@df.ufpe.br [Universidade Federal de Pernambuco, Departamento de Fisica (Brazil)

    2013-01-15

    We report the synthesis of stable polyaniline nanoparticles (PANI{sub N}Ps) based on the chemical oxidative polymerization of aniline in aqueous solutions of surfactants. Surfactants of three different types-cationic (dodecyltrimethylammonium bromide-DTAB), anionic (sodium dodecyl sulfate-SDS), and non-ionic (Triton X-405-TX-405)-were used. The resulting PANI{sub N}Ps{sub s}urfactant samples were characterized through UV-Vis, fluorescence and Fourier transform infrared spectroscopies, and scanning electronic microscopy (SEM). We have verified that the color of the PANI{sub N}Ps{sub s}urfactant dispersions is affected by a change in the pH of the solution. The PANI-NPs{sub s}urfactant colloidal suspensions in aqueous solution present a surprising high fluorescence quantum yield value (ranging from 1.9 Multiplication-Sign 10{sup -3} to 6.9 Multiplication-Sign 10{sup -3}) that can be controlled as a function of the pH, a fact that we associate to the corresponding protonation degree of the PANI polymeric chains. We suggest that these fluorescent nanocomposites can find important technological applications in different areas such as organic light emitting devices, biosensors, and pigments for coatings.

  7. Epidural top-up solutions for emergency caesarean section: a comparison of preparation times.

    Science.gov (United States)

    Lucas, D N; Borra, P J; Yentis, S M

    2000-04-01

    We compared the preparation times of three solutions commonly used for epidural top-up for emergency Caesarean section. Twenty-two anaesthetists were asked to prepare fresh solutions in random order as quickly as possible: 0.5% bupivacaine 20 ml (B); 2% lidocaine 20 ml with 1:200,000 epinephrine (LE); and 0.5% bupivacaine 10 ml and 2% lidocaine 10 ml with 1:200,000 epinephrine and 8.4% sodium bicarbonate 2 ml (BLEB). Preparation times for B were approximately half of those for LE, which in turn were approximately half of those for BLEB (P = 0.0001). If local anaesthetic solutions with additives such as epinephrine or bicarbonate are prepared just before emergency Caesarean section, any possible reduction in onset time that they might afford may be offset by the additional preparation time required.

  8. Correlation between wetting, adhesion and adsorption in the polymer-aqueous solutions of ternary surfactant mixtures-air systems

    Science.gov (United States)

    Szymczyk, Katarzyna; Zdziennicka, Anna; Krawczyk, Joanna; Jańczuk, Bronisław

    2014-01-01

    The correlation between the wettability of polymers and adsorption of ternary mixtures including CTAB, TX-100 and TX-114 at the polymer-aqueous solution interface as well as the adhesion of aqueous solution of these mixtures to apolar polytetrafluoroethylene (PTFE), monopolar polymethyl methacrylate (PMMA) and nylon 6 was considered on the basis of the contact angle measurements and the literature data of the solutions surface tension. From these considerations it appeared that the efficiency and effectiveness of the adsorption at the PTFE-water interface are comparable to those at the water-air one, but for the PMMA-water and nylon 6-water interfaces they are lower than those for the water-air one for a given series of solutions. The efficiency and effectiveness are reflected in the composition of the mixed monolayer at the polymer-solution interface which even for the PTFE-solution interface is somewhat different from the water-air interface. The properties of the mixed monolayer at these interfaces influence the critical surface tension of polymer wetting which for PTFE is somewhat higher but for PMMA and nylon 6 considerably lower than their surface tension. From these considerations it also appeared that the work of adhesion of aqueous solutions of ternary mixtures of surfactants to the PTFE surface does not depend on the composition and concentration of solution contrary to PMMA and nylon 6. The adhesion work of these solutions to the PMMA and nylon 6 surface can be determined on the basis of van Oss et al. and Neumann et al. equations.

  9. Preparation of Zeolite A from alkali solutions containing potassium

    Energy Technology Data Exchange (ETDEWEB)

    Goryachev, A.A.; Kuks, V.F.

    1983-03-20

    The most inexpensive general-purpose zeolite is Zeolite A. It is widely used as an adsorbent for drying hydrocarbon gases, for separation of normal paraffins, and recently as a component of synthetic detergents. The goal of this work was to study the effect of potassium, in crystallizing mixtures analogous to those used in industry, on the production of powdered Zeolite A and Zeolite A without binder on the basis of kaolin. It has been found that Zeolite A may be obtained upon crystallization of aluminosilica gel on the basis of aluminate and silicate solutions with a relative potassium content in the mixture to be crystallized that is not more than 0.8-0.14 mole fraction of the sum of the cations. In the case of crystallization of Zeolite A without binder on the basis of product, the amount of potassium should not be more than 5 rel. %. This is explained by the difference in the crystallization mechanism and the properties of the aluminate solutions containing potassium and silicon.

  10. Advanced titania buffer layer architectures prepared by chemical solution deposition

    Science.gov (United States)

    Kunert, J.; Bäcker, M.; Brunkahl, O.; Wesolowski, D.; Edney, C.; Clem, P.; Thomas, N.; Liersch, A.

    2011-08-01

    Chemical solution deposition (CSD) was used to grow high-quality (100) oriented films of SrTiO3 (STO) on CSD CaTiO3 (CTO), Ba0.1Ca0.9TiO3 (BCT) and STO seed and template layers. These template films bridge the lattice misfit between STO and the nickel-tungsten (NiW) substrate, assisting in dense growth of textured STO. Additional niobium (Nb) doping of the STO buffer layer reduces oxygen diffusion which is necessary to avoid undesired oxidation of the NiW. The investigated templates offer suitable alternatives to established standard buffer systems like La2Zr2O7 (LZO) and CeO2 for coated conductors.

  11. Structure of a passivated Ge surface prepared from aqueous solution.

    Energy Technology Data Exchange (ETDEWEB)

    Lyman, P. F.; Sakata, O.; Marasco, D, L.; Lee, T.-L.; Breneman, K. D.; Keane, D. T.; Bedzyk, M. J.; Materials Science Division; Northwestern Univ.; Univ. of Wisconsin at Milwaukee

    2000-08-10

    The structure of a passivating sulfide layer on Ge(001) was studied using X-ray standing waves and X-ray fluorescence. The sulfide layer was formed by reacting clean Ge substrates in (NH{sub 4}){sub 2}S solutions of various concentrations at 80{sup o}C. For each treatment, a sulfide layer containing approximately two to three monolayers (ML) of S was formed on the surface, and an ordered structure was found at the interface that contained approximately 0.4 ML of S. Our results suggest the rapid formation of a glassy GeS{sub x} layer containing 1.5-2.5 ML S residing atop a partially ordered interfacial layer of bridge-bonded S. The passivating reaction appears to be self-limited to 2-3 ML at this reaction temperature.

  12. Preparation of 3-D porous fibroin scaffolds by freeze drying with treatment of methanol solutions

    Institute of Scientific and Technical Information of China (English)

    ZHAN JingLin; SUN XiaoDan; CUI FuZhai; KONG XiangDong

    2007-01-01

    In this study,silk scaffolds with appropriate porous structures were prepared by adjusting solution concentrations and providing treatment with methanol solutions in the way of freeze drying. The effects of the preparation conditions on the microstructures and properties of the scaffolds were discussed. Fibroin solutions with different concentrations of 4,6,8,10 wt% were used respectively to prepare the scaffolds. The effects of the addition of 20 vol% methanol before or after freeze drying to the 4 wt% fibroin solution were investigated. As demonstrated by Scanning Electron Microscope (SEM),the fibroin scaffolds prepared without methanol had porous microstructures composed of thin sheets,and the sizes of the pores decreased with the increase of the fibroin solution concentrations,while the scaffolds prepared in the presence of methanol showed porous microstructures formed by fine-particle aggregates. The porosities and mechanical properties of the prepared fibroin scaffolds under different conditions were tested. The crystalline structures and conformations of the fibroin scaffolds were detected by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD).

  13. Morphology control of brushite prepared by aqueous solution synthesis

    Directory of Open Access Journals (Sweden)

    T. Toshima

    2014-03-01

    Full Text Available Dicalcium phosphate dihydrate (DCPD, CaHPO4·2H2O, also known as brushite, is one of the important bioceramics due to not only diseases factors such as kidney stone and plaque formation but also purpose as fluoride insolubilization material. It is used medicinally to supply calcium, and is of interest for its unique properties in biological and pathological mineralization. It is important to control the crystal morphology of brushite since its chemical reactivity depends strongly on its surface properties; thus, its morphology is a key issue for its applications as a functional material or precursor for other bioceramics. Here, we report the effects of the initial pH and the Ca and phosphate ion concentrations on the morphology of DCPD particles during aqueous solution synthesis. Crystal morphologies were analyzed by scanning electron microscopy and X-ray diffraction. The morphology phase diagram of DCPD crystallization revealed that increasing the initial pH and/or ion concentration transformed DCPD morphology from petal-like into plate-like structures.

  14. GAMSOR: Gamma Source Preparation and DIF3D Flux Solution

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M. A. [TerraPower, Bellevue, WA (United States); Lee, C. H. [TerraPower, Bellevue, WA (United States); Hill, R. N. [TerraPower, Bellevue, WA (United States)

    2017-06-28

    Nuclear reactors that rely upon the fission reaction have two modes of thermal energy deposition in the reactor system: neutron absorption and gamma absorption. The gamma rays are typically generated by neutron capture reactions or during the fission process which means the primary driver of energy production is of course the neutron interaction. In conventional reactor physics methods, the gamma heating component is ignored such that the gamma absorption is forced to occur at the gamma emission site. For experimental reactor systems like EBR-II and FFTF, the placement of structural pins and assemblies internal to the core leads to problems with power heating predictions because there is no fission power source internal to the assembly to dictate a spatial distribution of the power. As part of the EBR-II support work in the 1980s, the GAMSOR code was developed to assist analysts in calculating the gamma heating. The GAMSOR code is a modified version of DIF3D and actually functions within a sequence of DIF3D calculations. The gamma flux in a conventional fission reactor system does not perturb the neutron flux and thus the gamma flux calculation can be cast as a fixed source problem given a solution to the steady state neutron flux equation. This leads to a sequence of DIF3D calculations, called the GAMSOR sequence, which involves solving the neutron flux, then the gamma flux, and then combining the results to do a summary edit. In this manuscript, we go over the GAMSOR code and detail how it is put together and functions. We also discuss how to setup the GAMSOR sequence and input for each DIF3D calculation in the GAMSOR sequence.

  15. GAMSOR: Gamma Source Preparation and DIF3D Flux Solution

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M. A. [Argonne National Lab. (ANL), Argonne, IL (United States); Lee, C. H. [Argonne National Lab. (ANL), Argonne, IL (United States); Hill, R. N. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-12-15

    Nuclear reactors that rely upon the fission reaction have two modes of thermal energy deposition in the reactor system: neutron absorption and gamma absorption. The gamma rays are typically generated by neutron absorption reactions or during the fission process which means the primary driver of energy production is of course the neutron interaction. In conventional reactor physics methods, the gamma heating component is ignored such that the gamma absorption is forced to occur at the gamma emission site. For experimental reactor systems like EBR-II and FFTF, the placement of structural pins and assemblies internal to the core leads to problems with power heating predictions because there is no fission power source internal to the assembly to dictate a spatial distribution of the power. As part of the EBR-II support work in the 1980s, the GAMSOR code was developed to assist analysts in calculating the gamma heating. The GAMSOR code is a modified version of DIF3D and actually functions within a sequence of DIF3D calculations. The gamma flux in a conventional fission reactor system does not perturb the neutron flux and thus the gamma flux calculation can be cast as a fixed source problem given a solution to the steady state neutron flux equation. This leads to a sequence of DIF3D calculations, called the GAMSOR sequence, which involves solving the neutron flux, then the gamma flux, then combining the results to do a summary edit. In this manuscript, we go over the GAMSOR code and detail how it is put together and functions. We also discuss how to setup the GAMSOR sequence and input for each DIF3D calculation in the GAMSOR sequence. With the GAMSOR capability, users can take any valid steady state DIF3D calculation and compute the power distribution due to neutron and gamma heating. The MC2-3 code is the preferable companion code to use for generating neutron and gamma cross section data, but the GAMSOR code can accept cross section data from other sources. To further

  16. Preparation of CdTe nanocrystal-polymer composite microspheres in aqueous solution by dispersing method

    Institute of Scientific and Technical Information of China (English)

    LI Minjie; WANG Chunlei; HAN Kun; YANG Bai

    2005-01-01

    Highly fluorescent CdTe nanocrystals were synthesized in aqueous solution, and then processible CdTe nanocrystal-polymer composites were fabricated by coating the aqueous nanocrystals with copolymers of styrene and octadecyl-p-vinyl-benzyldimethylammonium chloride (SOV- DAC) directly. A dichloromethane solution of CdTe nano- crystal-polymer composites was dispersed in the aqueous solution of poly (vinyl alcohol) (PVA) generating highly fluorescent microspheres. Experimental parameters such as the concentration of nanocrystal-polymer composites, the concentration of PVA, and stirring speed which had important effect on the preparation of the microspheres were investigated in detail with fluorescent microscope characterization.

  17. Preparation of Ultrafine Cobalt Powder by Chemical Reduction in Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Nanocrystalline cobalt powders have been prepared from aqueous solution by reducing their corresponding metal salts under suitable conditions. The experimental conditions have been studied in detail. X-ray powder diffraction patterns show that the cobalt powder is hexagonal crystallite. The average particle size of the ultrafine cobalt powder is 55 nm.

  18. Preparation and utilization of wheat straw anionic sorbent for the removal of nitrate from aqueous solution.

    Science.gov (United States)

    Wang, Yu; Gao, Bao-yu; Yue, Wen-wen; Yue, Qin-yan

    2007-01-01

    In order to reduce the impact of eutrophication caused by agricultural residues (i.e., excess nitrate) in aqueous solution, economic and effective anionic sorbents are required. In this article, we prepared anionic sorbent using wheat straw. Its structural characteristics and adsorption properties for nitrate removal from aqueous solution were investigated. The results indicate that the yield of the prepared anionic sorbent, the total exchange capacity, and the maximum adsorption capacity were 350%, 2.57 mEq/g, and 2.08 mmol/g, respectively. The Freundlich isotherm mode is more suitable than the Langmuir mode and the adsorption process accords with the first order reaction kinetic rate equation. When multiple anions (SO4(2-), H2PO4(-), NO3(-), and NO2(-)) were present, the isotherm mode of prepared anionic sorbent for nitrate was consistent with Freundlich mode; however, the capacity of nitrate adsorption was reduced by 50%. In alkaline solutions, about 90% of adsorbed nitrate ions could be desorbed from prepared anionic sorbent. The results of this study confirmed that the wheat straw anionic sorbent can be used as an excellent nitrate sorbent that removes nitrate from aqueous solutions.

  19. Epitaxial ternary nitride thin films prepared by a chemical solution method

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Hongmei [Los Alamos National Laboratory; Feldmann, David M [Los Alamos National Laboratory; Wang, Haiyan [TEXAS A& M; Bi, Zhenxing [TEXAS A& M

    2008-01-01

    It is indispensable to use thin films for many technological applications. This is the first report of epitaxial growth of ternary nitride AMN2 films. Epitaxial tetragonal SrTiN2 films have been successfully prepared by a chemical solution approach, polymer-assisted deposition. The structural, electrical, and optical properties of the films are also investigated.

  20. 改性马来酸酐橡胶接枝物增韧尼龙6的制备及表征%Preparation and characterization of modified maleic anhydride graft rubber toughened nylon 6

    Institute of Scientific and Technical Information of China (English)

    顾晓华; 张希伟; 曾鹏; 宋雪; 程伟东

    2015-01-01

    为了促进橡胶接枝物与尼龙6(PA6)的相容性并提高增韧效果,利用马来酸酐和对苯二胺合成了一种含酰胺键的二元羧酸,命名为对苯马来二酰胺二酸(改性马来酸酐,MDMA),并将MDMA接枝到三元乙丙橡胶(EPDM)上,制备出不同接枝率的改性马来酸酐橡胶接枝物(EPDM-g-MDMA),以EPDM-g-MDMA与PA6质量比为30∶70,通过共混挤出制备了含不同接枝率接枝物的EPDM-g-MDMA/PA6共混物.通过核磁共振和红外光谱对MDMA进行了测试,表明成功合成了所需要的二元羧酸.对共混物进行了相容性测试、DSC、熔融指数(MI)、SEM、拉伸和冲击力学性能测试.结果表明:随着接枝率的增大,共混物的熔融峰温度略有降低,其熔体黏度不断增大,橡胶接枝物在PA6基体中有良好的分散性,使EPDM-g-MDMA/PA6共混物的冲击强度提高了5.5倍,说明EPDM-g-MDMA对PA6的增韧效果较为明显.

  1. Preparation of stable aqueous solution of keratins, and physiochemical and biodegradational properties of films.

    Science.gov (United States)

    Yamauchi, K; Yamauchi, A; Kusunoki, T; Kohda, A; Konishi, Y

    1996-08-01

    A stable aqueous solution of reduced keratins was prepared by extracting the proteins from wool (Corriedale) with a mixture of urea, mercaptanol, surfactant, and water at 40-60 degrees C. Sodium dodecyl sulfate was especially effective as a surfactant, not only in promoting extraction but also in stabilizing the aqueous protein solution. The proteins had the following constants: MW, 52,000-69,000 daltons; cysteine content, 8-9 mol%; pl about 6.7. A clear film was readily prepared from a keratin solution containing glycerol. The film was insoluble in water and organic solvents including dimethyl sulfoxide. The keratin film was permeable to glucose, urea, and sodium chloride. The keratin film was degraded in vitro (by trypsin) and in vivo (by subcutaneous embedding in mice).

  2. Copper zinc tin sulfide layers prepared from solution processable metal dithiocarbamate precursors

    Energy Technology Data Exchange (ETDEWEB)

    Edler, Michael [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 9, 8010 Graz (Austria); Christian Doppler Laboratory for Nanocomposite Solar Cells, Graz University of Technology and NanoTecCenter Weiz, Forschungsgesellschaft mbH (Austria); Rath, Thomas, E-mail: thomas.rath@tugraz.at [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 9, 8010 Graz (Austria); Christian Doppler Laboratory for Nanocomposite Solar Cells, Graz University of Technology and NanoTecCenter Weiz, Forschungsgesellschaft mbH (Austria); Schenk, Alexander [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 9, 8010 Graz (Austria); Fischereder, Achim [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 9, 8010 Graz (Austria); Christian Doppler Laboratory for Nanocomposite Solar Cells, Graz University of Technology and NanoTecCenter Weiz, Forschungsgesellschaft mbH (Austria); Haas, Wernfried [Christian Doppler Laboratory for Nanocomposite Solar Cells, Graz University of Technology and NanoTecCenter Weiz, Forschungsgesellschaft mbH (Austria); Institute for Electron Microscopy and Fine Structure Research, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Edler, Matthias [Chair of Chemistry of Polymeric Materials, University of Leoben, Otto Gloeckel-Strasse 2, 8700 Leoben (Austria); Chernev, Boril [Institute for Electron Microscopy and Fine Structure Research, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Kunert, Birgit [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz (Austria); Hofer, Ferdinand [Institute for Electron Microscopy and Fine Structure Research, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); and others

    2012-10-15

    In this contribution we present a solution based route toward copper zinc tin sulfide - CZTS - layers using metal dithiocarbamate precursors. We focus on the synthesis of the precursor materials as well as on the fabrication of thin CZTS layers at low temperatures of 350 Degree-Sign C and their characterization. Powder X-ray diffraction measurements show that a precursor solution containing an excess of the zinc precursor, compared to the Cu and Sn precursors, has to be used to obtain CZTS films without secondary phases. Thus, the prepared films are Zn-rich, which is beneficial for solar cell applications. Raman as well as X-ray photoelectron spectroscopy studies confirm the formation of CTZS. No clear evidence for free ZnS has been found. Electron microscopy shows agglomerates of 10 nm-sized crystallites forming spherical particles with a diameter between 50 nm and 400 nm. The prepared films possess high optical absorption (>1.10{sup 4} cm{sup -1}) and an optical band gap of approximately 1.6 eV. Highlights: Black-Right-Pointing-Pointer CZTS layers are prepared from metal dithiocarbamate precursor solu-tions. Black-Right-Pointing-Pointer No additional sulfur sources or capping agents are necessary. Black-Right-Pointing-Pointer Prepared CZTS layers are zinc rich. Black-Right-Pointing-Pointer CZTS layers show a high absorption coefficient and a band gap of 1.6 eV.

  3. Low temperature preparation of nanocrystalline solid solution of strontium barium niobate by chemical process

    Indian Academy of Sciences (India)

    Asit B Panda; Amita Pathak; Panchanan Pramanik

    2002-11-01

    SrBa1–Nb2O6 (with = 0.4, 0.5 and 0.6) powders have been prepared by thermolysis of aqueous precursor solutions consisting of triethanolamine (TEA), niobium tartarate and, EDTA complexes of strontium and barium ions. Complete evaporation of the precursor solution by heating at ∼ 200°C, yields in a fluffy, mesoporous carbon rich precursor material, which on calcination at 750°C/2 h has resulted in the pure SBN powders. The crystallite and average particle sizes are found to be around 15 nm and 20 nm, respectively.

  4. Aqueous Solution Preparation of Ruthenium Nanoparticles Using Ammonium Formate as the Reducing Agent

    Institute of Scientific and Technical Information of China (English)

    LIU Shaohong; CHEN Jialin; GUAN Weiming; BI Jun; CHEN Nanguang; CHEN Dengquan; LIU Manmen; SUN Xudong

    2012-01-01

    Ruthenium,one of the platinum group metals,has drawn much attention due to its catalytic behavior,hardness,electrical conductivity and density.Ruthenium particles are usually prepared on a small scale by the polyol process,however,the size of the obtained ruthenium nanoparticles is most below 10 nm.In this work,ruthenium particles about 200 nm in diameter were obtained in aqueous solution by using ammonium formate as the reducing agent.Tohave a better control of particle's size and shape,the effects of PVP,mixing mode,reaction temperature,solution pH and calcination temperature were investigated.

  5. Characterization of Laboratory Prepared Concrete Pastes Exposed to High Alkaline and High Sodium Salt Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-06-30

    The objective of this study was to identify potential chemical degradation mechanisms for the Saltstone Disposal Unit (SDU) concretes, which over the performance life of the structures may be exposed to highly alkaline sodium salt solutions containing sulfate, hydroxide, and other potentially corrosive chemicals in salt solution and saltstone flush water, drain water, leachate and / or pore solution. The samples analyzed in this study were cement pastes prepared in the SIMCO Technologies, Inc. concrete laboratory. They were based on the paste fractions of the concretes used to construct the Saltstone Disposal Units (SDUs). SDU 1 and 4 concrete pastes were represented by the PV1 test specimens. The paste in the SDU 2, 3, 5, and 6 concrete was represented by the PV2 test specimens. SIMCO Technologies, Inc. selected the chemicals and proportions in the aggressive solutions to approximate proportions in the saltstone pore solution [2, 3, 5, and 6]. These test specimens were cured for 56 days in curing chamber before being immersed in aggressive solutions. After exposure, the samples were frozen to prevent additional chemical transport and reaction. Selected archived (retrieved from the freezer) samples were sent to the Savannah River National Laboratory (SRNL) for additional characterization using x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray (EDX) spectroscopy. Characterization results are summarized in this report. In addition, a correlation between the oxide composition of the pastes and their chemical durability in the alkaline salt solutions is provided.

  6. Characteristics of zinc oxide nanorod array/titanium oxide film heterojunction prepared by aqueous solution deposition

    Science.gov (United States)

    Lee, Ming-Kwei; Hong, Min-Hsuan; Li, Bo-Wei

    2016-07-01

    The characteristics of a ZnO nanorod array/TiO2 film heterojunction were investigated. A TiO2 film was prepared on glass by aqueous solution deposition with precursors of ammonium hexafluorotitanate and boric acid at 40 °C. Then, a ZnO seed layer was prepared on a TiO2 film/glass substrate by RF sputtering. A vertically oriented ZnO nanorod array was grown on a ZnO seed layer/TiO2 film/glass substrate by aqueous solution deposition with precursors of zinc nitrate and hexamethylenetetramine (HMT) at 70 °C. After thermal annealing in N2O ambient at 300 °C, this heterojunction used as an oxygen gas sensor shows much better rise time, decay time, and on/off current ratio than as-grown and annealed ZnO nanorods.

  7. Preparation and Characterization of Organic-Inorganic Hybrid Hydrogel Electrolyte Using Alkaline Solution

    Directory of Open Access Journals (Sweden)

    Masanobu Chiku

    2011-09-01

    Full Text Available Organic-inorganic hybrid hydrogel electrolytes were prepared by mixing hydrotalcite, cross-linked potassium poly(acrylate and 6 M KOH solution. The organic-inorganic hybrid hydrogel electrolytes had high ionic conductivity (0.456–0.540 S cm−1 at 30 °C. Moreover, the mechanical strength of the hydrogel electrolytes was high enough to form a 2–3 mm thick freestanding membrane because of the reinforcement with hydrotalcite.

  8. Gravimetric preparation and characterization of primary reference solutions of molybdenum and rhodium.

    Science.gov (United States)

    Kaltenbach, Angela; Noordmann, Janine; Görlitz, Volker; Pape, Carola; Richter, Silke; Kipphardt, Heinrich; Kopp, Gernot; Jährling, Reinhard; Rienitz, Olaf; Güttler, Bernd

    2015-04-01

    Gravimetrically prepared mono-elemental reference solutions having a well-known mass fraction of approximately 1 g/kg (or a mass concentration of 1 g/L) define the very basis of virtually all measurements in inorganic analysis. Serving as the starting materials of all standard/calibration solutions, they link virtually all measurements of inorganic analytes (regardless of the method applied) to the purity of the solid materials (high-purity metals or salts) they were prepared from. In case these solid materials are characterized comprehensively with respect to their purity, this link also establishes direct metrological traceability to The International System of Units (SI). This, in turn, ensures the comparability of all results on the highest level achievable. Several national metrology institutes (NMIs) and designated institutes (DIs) have been working for nearly two decades in close cooperation with commercial producers on making an increasing number of traceable reference solutions available. Besides the comprehensive characterization of the solid starting materials, dissolving them both loss-free and completely under strict gravimetric control is a challenging problem in the case of several elements like molybdenum and rhodium. Within the framework of the European Metrology Research Programme (EMRP), in the Joint Research Project (JRP) called SIB09 Primary standards for challenging elements, reference solutions of molybdenum and rhodium were prepared directly from the respective metals with a relative expanded uncertainty associated with the mass fraction of U rel(w) < 0.05 %. To achieve this, a microwave-assisted digestion procedure for Rh and a hotplate digestion procedure for Mo were developed along with highly accurate and precise inductively coupled plasma optical emission spectrometry (ICP OES) and multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) methods required to assist with the preparation and as dissemination tools.

  9. Preparation of Laminin-apatite-polymer Composites Using Metastable Calcium Phosphate Solutions

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A synthetic polymer with a laminin-apatite composite layer on its surface would be useful as a percutaneous device. The preparation of such a composite was attempted in the present study using poly ( ethylene terephthalate ) (PET) and polyethylene ( PE ) as the synthetic polymer. PET and PE plates and those pretreated with an oxygen plasma were alternately dipped in calcium and phosphate ion solutions, and then immersed in a metastable ealcium phosphate solution supplemented with laminin ( LCP solution ). The PET and PE plates pretreated with an oxygen plasma formed a uniform and continuous layer of a laminin- apatite composite on their surfaces. In contrast, the PET and PE plates that had not been pretreated with an oxygen plasma did not form a continuous layer of a laminin-apatite composite on their surfaces. The hydrophilic functional groups on the PET and PE surfaces introduced by the plasma treatment were responsible for the successful laminin-apatite composite coating.

  10. Factors influencing HPAM solution viscosity prepared by produced water using orthogonal method

    Institute of Scientific and Technical Information of China (English)

    康万利; 王志伟; 周阳; 孟令伟; 刘述忍; 白宝君

    2008-01-01

    The effect of temperature and metal ion components on the viscosity of HPAM solution was studied by means of orthogonal method.Five factors and 4 levels were considered for the orthogonal design.The five factors included temperature,contents of Na+,Mg2+,Ca2+ and S2-,and the four levels mainly considered the level of produced water components in main oilfields in China.The experiment results show that temperature is the most important factor to control HPAM solution viscosity prepared by produced water.The effect of ions was in order of Na+>S2->Mg2+>Ca2+.The mechanism of each factor influencing viscosity was also discussed.Based on the actual condition of Nanyang oilfield,the desulfurization was used to improve the solution viscosity,and satisfactory result was obtained.

  11. Media-fill simulation tests in manual and robotic aseptic preparation of injection solutions in syringes.

    Science.gov (United States)

    Krämer, Irene; Federici, Matteo; Kaiser, Vanessa; Thiesen, Judith

    2016-04-01

    The purpose of this study was to evaluate the contamination rate of media-fill products either prepared automated with a robotic system (APOTECAchemo™) or prepared manually at cytotoxic workbenches in the same cleanroom environment and by experienced operators. Media fills were completed by microbiological environmental control in the critical zones and used to validate the cleaning and disinfection procedures of the robotic system. The aseptic preparation of patient individual ready-to-use injection solutions was simulated by using double concentrated tryptic soy broth as growth medium, water for injection and plastic syringes as primary packaging materials. Media fills were either prepared automated (500 units) in the robot or manually (500 units) in cytotoxic workbenches in the same cleanroom over a period of 18 working days. The test solutions were incubated at room temperature (22℃) over 4 weeks. Products were visually inspected for turbidity after a 2-week and 4-week period. Following incubation, growth promotion tests were performed with Staphylococcus epidermidis. During the media-fill procedures, passive air monitoring was performed with settle plates and surface monitoring with contact plates on predefined locations as well as fingerprints. The plates got incubated for 5-7 days at room temperature, followed by 2-3 days at 30-35℃ and the colony forming units (cfu) counted after both periods. The robot was cleaned and disinfected according to the established standard operating procedure on two working days prior to the media-fill session, while on six other working days only six critical components were sanitized at the end of the media-fill sessions. Every day UV irradiation was operated for 4 h after finishing work. None of the 1000 media-fill products prepared in the two different settings showed turbidity after the incubation period thereby indicating no contamination with microorganisms. All products remained uniform, clear, and light

  12. Preparation of Superhydrophobic ZnO Films on Zinc Substrate by Chemical Solution Method

    Institute of Scientific and Technical Information of China (English)

    XU Wen-guo; LI Ji-hong; LU Shi-xiang; DUAN Ya-qiong; MA Cheng-xiang; SHI Xiao-feng; CHEN Yi-ling; YANG Yan-bo

    2012-01-01

    Superhydrophobic surface was prepared on the zinc substrate by chemical solution method via immersing clean pure zinc substrate into a water solution of zinc nitrate hexahydrate[Zn(NO3)2.6H2O] and hexamethylenetetraamine(C6H12N4) at 95℃ in water bath for 1.5 h,then modified with 18 alkanethiol.The best resulting surface shows superhydrophobic properties with a water contact angle of about 158° and a low water roll-off angle of around 3°.The prepared samples were characterize.d by powder X-ray diffraction(XRD),X-ray photoelectron spectroscopy (XPS),energy-dispersive X-ray spectroscopy(EDX),transmission electron microscopy(TEM),and scanning electron microscopy(SEM).SEM images of the films show that the resulting surface exhibits flower-shaped micro- and nano-structure.The surfaces of the prepared films were composed of ZnO nanorods which were wurtzite structure.The special flower-like micro- and nano-structure along with the low surface energy leads to the surface superhydrophobicity.

  13. Anisotropic surface hole-transport property of triphenylamine-derivative single crystal prepared by solution method

    Science.gov (United States)

    Umeda, Minoru; Katagiri, Mitsuhiko; Shironita, Sayoko; Nagayama, Norio

    2016-12-01

    This paper reports the anisotropic hole transport at the triphenylamine-derivative single crystal surface prepared by a solution method. Triphenylamine derivatives are commonly used in a hole-transport material for organic photoconductors of laser-beam printers, in which the materials are used as an amorphous form. For developing organic photovoltaics using the photoconductor's technology, preparation of a single crystal seems to be a specific way by realizing the high mobility of an organic semiconductor. In this study, a single crystal of 4-(2,2-diphenylethenyl)-N,N-bis(4-methylphenyl)-benzenamine (TPA) was prepared and its anisotropic hole-transport property measured. First, the hole-transport property of the TPA was investigated based on its chemical structure and electrochemical redox characteristics. Next, a large-scale single crystal formation at a high rate was developed by employing a solution method based on its solubility and supersolubility curves. The grown TPA was found to be a single crystal based on the polarization micrograph observation and crystallographic analysis. For the TPA single crystal, an anisotropic surface conduction was found, which was well explained by its molecular stack structure. The measured current in the long-axis direction is one order of magnitude greater than that of amorphous TPA.

  14. Studies on adsorption of mercury from aqueous solution on activated carbons prepared from walnut shell.

    Science.gov (United States)

    Zabihi, M; Haghighi Asl, A; Ahmadpour, A

    2010-02-15

    The adsorption ability of a powdered activated carbons (PAC) derived from walnut shell was investigated in an attempt to produce more economic and effective sorbents for the control of Hg(II) ion from industrial liquid streams. Carbonaceous sorbents derived from local walnut shell, were prepared by chemical activation methods using ZnCl(2) as activating reagents. Adsorption of Hg(II) from aqueous solutions was carried out under different experimental conditions by varying treatment time, metal ion concentration, pH and solution temperature. It was shown that Hg(II) uptake decreases with increasing pH of the solution. The proper choice of preparation conditions were resulted in microporous activated carbons with different BET surface areas of 780 (Carbon A, 1:0.5 ZnCl(2)) and 803 (Carbon B, 1:1 ZnCl(2))m(2)/g BET surface area. The monolayer adsorption capacity of these particular adsorbents were obtained as 151.5 and 100.9 mg/g for carbons A and B, respectively. It was determined that Hg(II) adsorption follows both Langmuir and Freundlich isotherms as well as pseudo-second-order kinetics.

  15. Preparation and characterization of regenerated fiber from the aqueous solution of Bombyx mori cocoon silk fibroin

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Zhenghua [Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan); Department of Application Engineering, ZheJiang Vocational College of Economic and Trade, HangZhou, ZheJiang 310018 (China); Imada, Takuzo [Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan); Asakura, Tetsuo, E-mail: asakura@cc.tuat.ac.jp [Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan)

    2009-10-15

    The regenerated silk fibers with high strength and high biodegradability were prepared from the aqueous solution of Bombyx mori silk fibroin from cocoons with wet spinning method. Although the tensile strength of the regenerated silk fibroin fiber, 210 MPa is still half of the strength of native silk fiber, the diameter of the fiber is about 100 {mu}m which is suitable for monofilament of suture together with high biodegradability. The high concentration (30%, w/v) of the aqueous solution of the silk fibroin which corresponds to the high concentration in the middle silkgland of silkworm was obtained. This was performed by adjusting the pH of the aqueous solution to 10.4 which corresponds to pK{sub a} value of the OH group of Tyr residues in the silk fibroin. The mixed solvent, methanol/acetic acid (7:3 in volume ratio) was used as coagulant solvent for preparing the regenerated fiber. The structural change of silk fibroin fiber by stretching was monitored with both {sup 13}C solid state NMR and X-ray diffraction methods, indicating that the high strength of the fiber is related with the long-range orientation of the silk fibroin chain with {beta}-sheet structure.

  16. Synthesis and characterization of quaternized bacterial cellulose prepared in homogeneous aqueous solution.

    Science.gov (United States)

    Zhang, Hairong; Guo, Haijun; Wang, Bo; Shi, Silan; Xiong, Lian; Chen, Xinde

    2016-01-20

    In this work, bacterial cellulose (BC) was activated by ethylenediamine (EDA) and then dissolved in lithium chloride/N,N-dimethylacetamide (LiCl/DMAc) aqueous solutions. The resulting transparent solution was cast on a glass plate to prepare regenerated BC. Then cationic BC was prepared homogeneously by the reaction between regenerated BC and 3-chloro-2-hydroxypropyl-trimethyl ammonium chloride (CHPTAC) in a NaOH/urea aqueous solution. Structure and properties of the BC and its products were characterized by different techniques such as X-ray diffraction (XRD), Fourier transform spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA). The results showed that there was no significant difference between the structures of BC, activated BC and regenerated BC. The effects of different temperature and molar ratio of CHPTAC to anhydroglucose unit (AGU) on the degree of substitution (DS) value were examined. The DS values of cationic BC ranged between 0.21 and 0.51.

  17. Red-emitting alkaline-earth rare-earth pentaoxometallates powders prepared by metal carboxylates solution

    Indian Academy of Sciences (India)

    Kyu-Seog Hwang; Sung-Dae Kim; Seung Hwangbo; Jin-Tae Kim

    2013-06-01

    Moisture-insensitive metal carboxylates that are mostly liquids at room temperature have been first applied to the preparation of strontium europium aluminate (Sr2EuAlO5) powders for red-emitting phosphor under near ultraviolet radiation. Strontium naphthenate, aluminium-2-ethylhexanoate and europium-2-ethylhexanoate were dissolved with toluene to prepare starting solution. Precursor pyrolyzed at 500 °C for 240 min was finally annealed at 900–1200 °C for 240 min in Ar. X-ray diffraction analysis, field emission–scanning electron microscope and fluorescent spectrophotometer were used to evaluate structural and optical properties. For the 1000 °C-annealed powders with regular shape and narrow size distribution confirmed by FE–SEM observation, strong red emission at 615nm under the excitation of 395nm maximum was reached, then the higher annealed samples at above 1100 °C gave the lower emission intensities.

  18. PREPARATION OF POLY(METHYL METHACRYLATE)/LAYERED DOUBLE HYDROXIDES NANOCOMPOSITES via in situ SOLUTION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An exfoliated layered double hydroxides/poly(methyl methacrylate) (LDHs/PMMA) nanocomposite was prepared by in situ solution polymerization of methyl methacrylate (MMA) in the presence of 4-vinylbenzenesulfonate intercalated LDHs(MgAl-VBS LDHs). MgAl-VBS LDHs was prepared by the ion exchange method, and the structure and composition of the MgAl-VBS LDHs were determined by X-ray diffraction (XRD), infrared spectroscopy and elemental analysis. XRD and transmission electron microscopy (TEM) were employed to examine the structure of LDHs/PMMA nanocomposite. It was indicated that the LDHs layers were well exfoliated and dispersed in the PMMA matrix. The grafting of PMMA onto LDHs was confirmed by the extraction result and the weight fraction of grafted PMMA increased as the weight fraction of LDHs in the nanocomposites increased.

  19. Effect of Soft-annealing on the Properties of CIGSe Thin Films Prepared from Solution Precursors

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Shijoon; Park, Misun; Kim, Daehwan; Kang, Jinkyu [Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of)

    2013-05-15

    Solution-based deposition of CuIn{sub x}Ga{sub 1-x}Se{sub 2} (CIGSe) thin films is well known non-vacuum process for the fabrication of CIGSe solar cells. However, due to the usage of organic chemicals in the preparation of CIG precursor solutions, the crystallization of the polycrystalline CIGSe and the performance of CIGSe thin film solar cells were significantly affected by the carbon residues from the organic chemicals. In this work, we have tried to eliminate the carbon residues in the CIG precursor thin films efficiently by using soft-annealing process. By adjusting soft-annealing temperature, it is possible to control the amount of carbon residues in CIG precursor thin films. The reduction of the carbon residues in CIG precursors by high temperature soft-annealing improves the grain size and morphology of polycrystalline CIGSe thin films, which are also closely related with the electrical properties of CIGSe thin film solar cells.

  20. Preparation, Characterization and Catalytic Performance of Nanometer Ceria-Zirconia Solid Solution

    Institute of Scientific and Technical Information of China (English)

    Hu Yucai; Wang Yinghui; Pan Junyan

    2004-01-01

    Ce0.6Zr0.4O2 solid solution was prepared by co-precipitation technique using hydrazine hydrate as precipitator.Various physico-chemical techniques such as XRD, FT-Raman, SEM, TEM, etc.were used to characterize the resultant powder.Meanwhile, its catalytic activity was evaluated in the synthesis of n-butyl acetate by the reaction of acetic acid and n-butyl alcohol.The results show that ceria-zirconia solid solution forms single cubic structure and its particle diameter is less than 100 nm.As a sort of solid acid, it possesses high catalytic activity and can be easily separated from reaction liquid.After it is used for ten times, its activity basically kees unchanging.

  1. SANS studies of solutions and molecular composites prepared from cellulose tricarbanilate

    CERN Document Server

    Alava, C; Cameron, J D; Cowie, J M G; Vaqueiro, P; Möller, A; Triolo, A

    2002-01-01

    We report on SANS measurements carried out on the instrument SANS1 (V4) at the BENSC facility on solutions and composites of cellulose tricarbanilate (CTC). This cellulose derivative exhibits lyotropic behaviour in methylacrylate (MA). The SANS data indicate that in the isotropic liquid state (up to 25% wt CTC in MA) the CTC chains behave like rods of mass per unit length (M/L). In the liquid crystalline (LC) phase (at and above 35% wt CTC in MA), the Q dependence varies from Q sup - sup 1 to Q sup - sup 4 , probably as a result of self-assembling of the CTC chains. The general aim of our work is to prepare molecular composites, i.e. miscible blends of rigid-rod and flexible-coil polymers, from CTC solutions in polymerizable media. To establish the degree of homogeneity of the composites, we performed SANS measurements on UV-cured CTC/MA solutions. Here, we compare the SANS data of CTC/monomer solutions with those of the corresponding composites. (orig.)

  2. SANS studies of solutions and molecular composites prepared from cellulose tricarbanilate

    Energy Technology Data Exchange (ETDEWEB)

    Alava, C.; Arrighi, V.; Cameron, J.D.; Cowie, J.M.G.; Vaqueiro, P. [Department of Chemistry, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Moeller, A.; Triolo, A. [Hahn-Meitner-Institut-BENSC, Glienicker Strasse 100, 14109 Berlin (Germany)

    2002-07-01

    We report on SANS measurements carried out on the instrument SANS1 (V4) at the BENSC facility on solutions and composites of cellulose tricarbanilate (CTC). This cellulose derivative exhibits lyotropic behaviour in methylacrylate (MA). The SANS data indicate that in the isotropic liquid state (up to 25% wt CTC in MA) the CTC chains behave like rods of mass per unit length (M/L). In the liquid crystalline (LC) phase (at and above 35% wt CTC in MA), the Q dependence varies from Q{sup -1} to Q{sup -4}, probably as a result of self-assembling of the CTC chains. The general aim of our work is to prepare molecular composites, i.e. miscible blends of rigid-rod and flexible-coil polymers, from CTC solutions in polymerizable media. To establish the degree of homogeneity of the composites, we performed SANS measurements on UV-cured CTC/MA solutions. Here, we compare the SANS data of CTC/monomer solutions with those of the corresponding composites. (orig.)

  3. Preparation of chitosan films using different neutralizing solutions to improve endothelial cell compatibility.

    Science.gov (United States)

    He, Qing; Ao, Qiang; Gong, Yandao; Zhang, Xiufang

    2011-12-01

    The development of chitosan-based constructs for application in large-size defects or highly vascularized tissues is still a challenging issue. The poor endothelial cell compatibility of chitosan hinders the colonization of vascular endothelial cells in the chitosan-based constructs, and retards the establishment of a functional microvascular network following implantation. The aim of the present study is to prepare chitosan films with different neutralization methods to improve their endothelial cell compatibility. Chitosan salt films were neutralized with either sodium hydroxide (NaOH) aqueous solution, NaOH ethanol solution, or ethanol solution without NaOH. The physicochemical properties and endothelial cell compatibility of the chitosan films were investigated. Results indicated that neutralization with different solutions affected the surface chemistry, swelling ratio, crystalline conformation, nanotopography, and mechanical properties of the chitosan films. The NaOH ethanol solution-neutralized chitosan film (Chi-NaOH/EtOH film) displayed a nanofiber-dominant surface, while the NaOH aqueous solution-neutralized film (Chi-NaOH/H(2)O film) and the ethanol solution-neutralized film (Chi-EtOH film) displayed nanoparticle-dominant surfaces. Moreover, the Chi-NaOH/EtOH films exhibited a higher stiffness as compared to the Chi-NaOH/H(2)O and Chi-EtOH films. Endothelial cell compatibility of the chitosan films was evaluated with a human microvascular endothelial cell line, HMEC-1. Compared with the Chi-NaOH/H(2)O and Chi-EtOH films, HMECs cultured on the Chi-NaOH/EtOH films fully spread and exhibited significantly higher levels of adhesion and proliferation, with retention of the endothelial phenotype and function. Our findings suggest that the surface nanotopography and mechanical properties contribute to determining the endothelial cell compatibility of chitosan films. The nature of the neutralizing solutions can affect the physicochemical properties and

  4. Preparation of conductive PDDA/(PEDOT:PSS) multilayer thin film: influence of polyelectrolyte solution composition.

    Science.gov (United States)

    Jurin, F E; Buron, C C; Martin, N; Filiâtre, C

    2014-10-01

    Self-assembled multilayer films made of PEDOT:PSS poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) and PDDA poly(diallyldimethylammonium chloride) were prepared using layer-by-layer method. In order to modify the growth regime of the multilayer, to fabricate an electrical conductive film and to control its thickness, the effects of pH, type of electrolyte, ionic strength and polyelectrolyte concentration were investigated. Optical reflectometry measurements show that the pH of the solutions has no effect on the film growth while the adsorbed amount increases more rapidly when BaCl2 is used instead of NaCl as electrolyte. An increase in the ionic strength (with NaCl) induces a change in the growth regime from a linear to an exponential one at low polyelectrolyte concentration. As UV-vis measurements indicate, no decomplexation of PEDOT was recorded after film preparation. With polyelectrolyte concentration below 1 g L(-1), no conductive films were obtained even if 50 bilayers were deposited. A conductive film was prepared with a polyelectrolyte concentration of 1 g L(-1) and the measured conductivity was 0.3 S m(-1). A slight increase in conductivity was recorded when BaCl2 was used probably due to a modification of the film structure. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Experimental improvements in sample preparation for the track registration technique from dry and solution media

    Energy Technology Data Exchange (ETDEWEB)

    Suarez-Navarro, M.J. [Universidad Politecnica de Madrid (UPM), E.T.S.I de Caminos, Canales y Puertos, Profesor Aranguren s/n, 28040 Madrid (Spain)]. E-mail: he04@caminos.upm.es; Pujol, Ll. [Centro de Estudios y Experimentacion de Obras Publicas (CEDEX), Alfonso XII, 3, 28014 Madrid (Spain); Gonzalez-Gonzalez, J.A. [Universidad Politecnica de Madrid (UPM), E.T.S.I de Caminos, Canales y Puertos, Profesor Aranguren s/n, 28040 Madrid (Spain)

    2006-04-15

    This paper describes the sample preparation studies carried out to determine gross alpha activities in waste materials by means of alpha-particle track counting using CR-39 detector. Sample preparation for the track registration technique using evaporation or electroplating methods (also known as conventional 'dry methods') has a number of drawbacks. The distribution of tracks in different areas of the detector surface is non-uniform, so accurate quantitative determinations depend on tedious and time-consuming counting of tracks under an optical microscope. In this paper, we propose the use of tensioactives in sample preparation to achieve uniform track distribution over the entire detector surface, which enables track density to be evaluated by scanning a small representative area. Under our counting conditions, uniform distribution was achieved with 0.2 ml of Teg from a planchetted source. Furthermore, track registration techniques using solution media (also known as the 'wet methods') and conventional 'dry methods' were analysed and compared with the proposed method. The reproducibility of the procedure described in the study was tested by analysing gross alpha activity in two low-level nuclear waste samples at two different laboratories.

  6. 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.

  7. Preparation of Macroporous Epitaxial Quartz Films on Silicon by Chemical Solution Deposition.

    Science.gov (United States)

    Carretero-Genevrier, Adrián; Gich, Martí

    2015-12-21

    This work describes the detailed protocol for preparing piezoelectric macroporous epitaxial quartz films on silicon(100) substrates. This is a three-step process based on the preparation of a sol in a one-pot synthesis which is followed by the deposition of a gel film on Si(100) substrates by evaporation induced self-assembly using the dip-coating technique and ends with a thermal treatment of the material to induce the gel crystallization and the growth of the quartz film. The formation of a silica gel is based on the reaction of a tetraethyl orthosilicate and water, catalyzed by HCl, in ethanol. However, the solution contains two additional components that are essential for preparing mesoporous epitaxial quartz films from these silica gels dip-coated on Si. Alkaline earth ions, like Sr(2+) act as glass melting agents that facilitate the crystallization of silica and in combination with cetyl trimethylammonium bromide (CTAB) amphiphilic template form a phase separation responsible of the macroporosity of the films. The good matching between the quartz and silicon cell parameters is also essential in the stabilization of quartz over other SiO2 polymorphs and is at the origin of the epitaxial growth.

  8. Preparation of porous carbon sphere from waste sugar solution for electric double-layer capacitor

    Science.gov (United States)

    Hao, Zhi-Qiang; Cao, Jing-Pei; Wu, Yan; Zhao, Xiao-Yan; Zhuang, Qi-Qi; Wang, Xing-Yong; Wei, Xian-Yong

    2017-09-01

    Waste sugar solution (WSS), which contains abundant 2-keto-L-gulonic acid, is harmful to the environment if discharged directly. For value-added utilization of the waste resource, a novel process is developed for preparation of porous carbon spheres by hydrothermal carbonization (HTC) of WSS followed by KOH activation. Additionally, the possible preparation mechanism of carbon spheres is proposed. The effects of hydrothermal and activation parameters on the properties of the carbon sphere are also investigated. The carbon sphere is applied to electric double-layer capacitor and its electrochemical performance is studied. These results show that the carbon sphere obtained by HTC at 180 °C for 12 h with the WSS/deionized water volume ratio of 2/3 possess the highest specific capacitance under identical activation conditions. The specific capacitance of the carbon spheres can reach 296.1 F g-1 at a current density of 40 mA g-1. Besides, excellent cycle life and good capacitance retention (89.6%) are observed at 1.5 A g-1 after 5000 cycles. This study not only provides a facile and potential method for the WSS treatment, but also achieves the high value-added recycling of WSS for the preparation of porous carbon spheres with superior electrochemical properties.

  9. Comparison of physicomechanical properties of films prepared from organic solutions and aqueous dispersion of Eudragit RL

    Directory of Open Access Journals (Sweden)

    H Afrasiabi Garekani

    2011-05-01

    Full Text Available Background and the purpose of the study: Mechanical properties of films prepared from aqueous dispersion and organic solutions of Eudragit RL were assessed and the effects of plasticizer type, concentration and curing were examined. Methods: Films were prepared from aqueous dispersion and solutions of Eudragit RL (isopropyl alcohol-water 9:1 containing 0, 10 or 20% (based on polymer weight of PEG 400 or Triethyl Citrate (TEC as plasticizer using casting method. Samples of films were stored in oven at 60ºC for 24 hrs (Cured. The stress-strain curve was obtained for each film using material testing machine and tensile strength, elastic modulus, %elongation and work of failure were calculated. Results and major conclusion: The films with no plasticizer showed different mechanical properties depending on the vehicle used. Addition of 10% or 20% of plasticizer decreased the tensile strength and elastic modulus and increased %elongation and work of failure for all films. The effect of PEG400 on mechanical properties of Eudragit RL films was more pronounced. The differences in mechanical properties of the films due to vehicle decreased by addition of plasticizer and increase in its concentration. Curing process weakened the mechanical properties of the films with no plasticizer and for films with 10% plasticizer no considerable difference in mechanical properties was observed before and after curing. For those with 20% plasticizer only films prepared from aqueous dispersion showed remarkable difference in mechanical properties before and after curing. Results of this study suggest that the mechanical properties of the Eudragit RL films were affected by the vehicle, type of plasticizer and its concentration in the coating liquid.

  10. Chitosan-based hydrogel for dye removal from aqueous solutions: Optimization of the preparation procedure

    Science.gov (United States)

    Gioiella, Lucia; Altobelli, Rosaria; de Luna, Martina Salzano; Filippone, Giovanni

    2016-05-01

    The efficacy of chitosan-based hydrogels in the removal of dyes from aqueous solutions has been investigated as a function of different parameters. Hydrogels were obtained by gelation of chitosan with a non-toxic gelling agent based on an aqueous basic solution. The preparation procedure has been optimized in terms of chitosan concentration in the starting solution, gelling agent concentration and chitosan-to-gelling agent ratio. The goal is to properly select the material- and process-related parameters in order to optimize the performances of the chitosan-based dye adsorbent. First, the influence of such factors on the gelling process has been studied from a kinetic point of view. Then, the effects on the adsorption capacity and kinetics of the chitosan hydrogels obtained in different conditions have been investigated. A common food dye (Indigo Carmine) has been used for this purpose. Noticeably, although the disk-shaped hydrogels are in the bulk form, their adsorption capacity is comparable to that reported in the literature for films and beads. In addition, the bulk samples can be easily separated from the liquid phase after the adsorption process, which is highly attractive from a practical point of view. Compression tests reveal that the samples do not breakup even after relatively large compressive strains. The obtained results suggest that the fine tuning of the process parameters allows the production of mechanical resistant and highly adsorbing chitosan-based hydrogels.

  11. A modified coaxial electrospinning for preparing fibers from a high concentration polymer solution

    Directory of Open Access Journals (Sweden)

    2011-08-01

    Full Text Available A new process technology modified from conventional coaxial electrospinning process has been developed to prepare polymer fibers from a high concentration solution. This process involves a pure solvent concentrically surrounding polymer fluid in the spinneret. The concentric spinneret was constructed simply by inserting a metal needle through a high elastic silica gel tube. Two syringe pumps were used to drive the core polymer solution and the sheath solvent. Using polyvinylpyrrolidone (PVP as the polymer model, which normally has an electrospinnable concentration of 10% w/v in ethanol, it was possible to electrospin 35% w/v of PVP in the same solvent, when pure N, N-dimethylacetamide (DMAc was used as sheath fluid. The resultant fibers have a smooth surface morphology and good structural uniformity. The diameter of the fibers was 2.0±0.25 µm when the DMAc-to-polymer-solution flow rate ratio was set as 0.1. The process technology reported here opens a new window to tune the polymer fibers obtained by the electrospinning, and is useful for improving productivity of the electrospinning process.

  12. Preparation of Dis-Azo Dyes Derived from p-Aminophenol and Their Fastness Properties for Synthetic Polymer-Fibres

    Science.gov (United States)

    Otutu, J. O.; Okoro, D.; Ossai, E. K.

    The preparation and properties of a series of dis-azo dyes derived from p-aminophenol is described. The influence on colour, dyeing fastness properties of the dyes on synthetic polymer-fibres is reported. Most of the dyes synthesized afford better light fastness and better wet (wash, perspiration) fastness on PET than on nylon 6 fabric. The structure of each compound was confirmed by using infrared, UV-VIS and elemental analysis.

  13. Continuous absorption of CO2 in packed column using MDEA solution for biomethane preparation

    Science.gov (United States)

    Mindaryani, A.; Budhijanto, W.; Ningrum, S. S.

    2016-11-01

    Nowadays, the energy consumption in Indonesia is increasing. Raising of energy consumption force Indonesia to find other energy resources. Biogas is one of the renewable energy, which was developed in anticipation to the fossil energy reduction. Reducing the content of impurities in biogas may reduce the corrosion impact and increase the combustion efficiency. The biomethane can be utilised as fuel for generator in small and medium scale industries (IKM). Continuous CO2 absorption in packed column using MDEA solution as absorbent is studied for biomethane preparation. CO2 absorption experiments was performed continuously in the packed absorption column with a diameter of 6 cm and 75 cm length. Gas is sparged from the bottom of the column while the liquid is pumped through the top of the column. The concentration of CO2 at exit gas is analysed by GC and recorded as a function of time. The flowrate of the inlet gas was varied at 1 LPM; 1.5 LPM; and 1.8 LPM. Variation of MDEA solution concentration used was 20% and 35.31%. Mathematical model for unsteady state CO2 absorption in packed column was developed. The reaction rate constant (k) and mass transfer coefficient KGa were determined by fitting the outlet CO2 concentration data as a function of time to the model solution with smallest Sum of Square of Errors (SSE). The experimental data shows that absorption of 1 LPM gas flow rate with 0,15 LPM MDEA solution flow rate may reduce 40 % CO2 to be 17 % CO2 in outlet gas. The steady state process reaches at 10 minutes. Increasing gas flow rates shows the higher overall mass transfer coefficient. The reaction rate constant is not affected by gas flow rate variation.

  14. [Nasal submicron emulsion of Scutellariae Radix extract preparation technology research based on phase transfer of solute technology].

    Science.gov (United States)

    Shi, Ya-jun; Shi, Jun-hui; Chen, Shi-bin; Yang, Ming

    2015-07-01

    Based on the demand of nasal drug delivery high drug loadings, using the unique phase transfer of solute, integrating the phospholipid complex preparation and submicron emulsion molding process of Scutellariae Radix extract, the study obtained the preparation of the high drug loadings submicron emulsion of Scutellariae Radix extract. In the study of drug solution dispersion method, the uniformity of drug dispersed as the evaluation index, the traditional mixing method, grinding, homogenate and solute phase transfer technology were investigated, and the solute phase transfer technology was adopted in the last. With the adoption of new technology, the drug loading capacity reached 1.33% (phospholipid complex was 4%). The drug loading capacity was improved significantly. The transfer of solute method and timing were studied as follows,join the oil phase when the volume of phospholipid complex anhydrous ethanol solution remaining 30%, the solute phase transfer was completed with the continued recycling of anhydrous ethanol. After drug dissolved away to oil phase, the preparation technology of colostrum was determined with the evaluation index of emulsion droplet form. The particle size of submicron emulsion, PDI and stability parameters were used as evaluation index, orthogonal methodology were adopted to optimize the submicron emulsion ingredient and main influential factors of high pressure homogenization technology. The optimized preparation technology of Scutellariae Radix extract nasal submicron emulsion is practical and stable.

  15. Preparation of {0 1 0}-faceted anatase TiO2 nanocuboids from peroxotitanium complex solution

    Science.gov (United States)

    Miao, Yigao; Gao, Jiacheng

    2012-12-01

    {0 1 0}-faceted anatase TiO2 nanocuboids have been fabricated by hydrothermal route using peroxotitanium complex solution as precursor. The effects of reaction time, the amount of urea and temperature on the formation of {0 1 0}-faceted anatase TiO2 were characterized by XRD, FESEM and TEM. The growth mechanism of nanocuboids was proposed that the nanocuboids were formed by the transition from H2Ti2O5·H2O phase to anatase TiO2 in the basic condition. The photocatalytic performance of the prepared samples was tested in the degradation of Rhodamine B and the anatase nanocuboids exhibited enhanced photocatalytic activity compared with the standard P25 powders.

  16. MWCNTs/Cellulose Hydrogels Prepared from NaOH/Urea Aqueous Solution with Improved Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Yingpu Zhang

    2015-01-01

    Full Text Available Novel high strength composite hydrogels were designed and synthesized by introducing multiwalled carbon nanotubes (MWCNTs into cellulose/NaOH/urea aqueous solution and then cross-linked by epichlorohydrin. MWCNTs were used to modify the matrix of cellulose. The structure and morphology of the hydrogels were characterized by Fourier transform infrared (FT-IR spectroscopy, high resolution transmission electron microscopy (HR-TEM, and scanning electron microscopy (SEM. The results from swelling testing revealed that the equilibrium swelling ratio of hydrogels decreased with the increment of MWCNTs content. Thermogravimetric analysis (TGA and dynamic mechanical analysis (DMA results demonstrated that the introduction of MWCNT into cellulose hydrogel networks remarkably improved both thermal and mechanical properties of the composite hydrogels. The preparation of MWCNTs modifiedcellulose-based composites with improved mechanical properties was the first important step towards the development of advanced functional materials.

  17. High quality thin films of thermoelectric misfit cobalt oxides prepared by a chemical solution method

    Science.gov (United States)

    Rivas-Murias, Beatriz; Manuel Vila-Fungueiriño, José; Rivadulla, Francisco

    2015-01-01

    Misfit cobaltates ([Bi/Ba/Sr/Ca/CoO]nRS[CoO2]q) constitute the most promising family of thermoelectric oxides for high temperature energy harvesting. However, their complex structure and chemical composition makes extremely challenging their deposition by high-vacuum physical techniques. Therefore, many of them have not been prepared as thin films until now. Here we report the synthesis of high-quality epitaxial thin films of the most representative members of this family of compounds by a water-based chemical solution deposition method. The films show an exceptional crystalline quality, with an electrical conductivity and thermopower comparable to single crystals. These properties are linked to the epitaxial matching of the rock-salt layers of the structure to the substrate, producing clean interfaces free of amorphous phases. This is an important step forward for the integration of these materials with complementary n-type thermoelectric oxides in multilayer nanostructures. PMID:26153533

  18. High quality thin films of thermoelectric misfit cobalt oxides prepared by a chemical solution method.

    Science.gov (United States)

    Rivas-Murias, Beatriz; Manuel Vila-Fungueiriño, José; Rivadulla, Francisco

    2015-07-08

    Misfit cobaltates ([Bi/Ba/Sr/Ca/CoO]n(RS)[CoO2]q) constitute the most promising family of thermoelectric oxides for high temperature energy harvesting. However, their complex structure and chemical composition makes extremely challenging their deposition by high-vacuum physical techniques. Therefore, many of them have not been prepared as thin films until now. Here we report the synthesis of high-quality epitaxial thin films of the most representative members of this family of compounds by a water-based chemical solution deposition method. The films show an exceptional crystalline quality, with an electrical conductivity and thermopower comparable to single crystals. These properties are linked to the epitaxial matching of the rock-salt layers of the structure to the substrate, producing clean interfaces free of amorphous phases. This is an important step forward for the integration of these materials with complementary n-type thermoelectric oxides in multilayer nanostructures.

  19. The first preparative solution phase synthesis of melanotan II

    Directory of Open Access Journals (Sweden)

    2008-10-01

    Full Text Available Melanotan II is a synthetic cyclic heptapeptide used to prevent a sunlight-induced skin cancer by stimulating the skin tanning process. In this paper we report the first solution phase synthesis of the title compound. The hexapeptide sequence has been assembled by [(2+2+1+1] scheme. After removing the orthogonal protection, a carbodiimide mediated lactamization, involving the ε-amino group of lysine and γ-carboxy group of aspartic acid, led to a cyclic intermediate. Appending N-acetylnorleucine concluded the assembly of melanotan II molecule. Protection of the lateral groups in arginine and tryptophan was omitted for atom and step economy reasons. The total synthesis of melanotan II was accomplished in 12 steps with 2.6% overall yield, affording >90% pure peptide without using preparative chromatography.

  20. Clozapine-carboxylic acid plasticized co-amorphous dispersions: Preparation, characterization and solution stability evaluation

    Directory of Open Access Journals (Sweden)

    Ali Ahmed Mahmoud Abdelhaleem

    2015-06-01

    Full Text Available This study addressed the possibility of forming of co-amorphous systems between clozapine (CZ and various carboxylic acid plasticizers (CAPs. The aim was to improve the solubility and oral bioavailability of clozapine. Co-amorphous dispersions were prepared using modified solvent evaporation methodology at drug/plasticizer stoichiometric ratios of 1:1, 1:1.5 and 1:2. Solid state characterization was performed using differential scanning calorimetry, X-ray diffraction and infra red spectroscopy. Highly soluble homogeneous co-amorphous dispersions were formed between clozapine and CAPs via hydrogen bonding. The co-amorphous dispersions formed with tartaric acid (1:2 showed the highest dissolution percentage (> 95 % in 20 minutes compared to pure crystalline CZ (56 %. Highly stable solutions were obtained from co-amorphous CZ-citric and CZ-tartaric acid at 1:1.5 molar ratio. The prepared dispersions suggest the possibility of peroral or sublingual administration of highly soluble clozapine at a reduced dose with the great chance to bypass the first pass metabolism.

  1. Adsorption of Pb(2+) from aqueous solution using spinel ferrite prepared from steel pickling sludge.

    Science.gov (United States)

    Fang, Binbin; Yan, Yubo; Yang, Yang; Wang, Fenglian; Chu, Zhen; Sun, Xiuyun; Li, Jiansheng; Wang, Lianjun

    2016-01-01

    In this paper, spinel ferrite with high crystallinity and high saturation magnetization was successfully prepared from steel pickling sludge by adding iron source and precipitator in the hydrothermal condition. The obtained spinel ferrite was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM), and Zeta potential methods and investigated as an adsorbent for removal of Pb(2+) from aqueous solution. Batch experiments were performed by varying the pH values, contact time, temperature and initial metal concentration. The result of pH impact showed that the adsorption of Pb(2+) was a pH dependent process, and the pH 5.8 ± 0.2 was found to be the optimum condition. The achieved experimental data were analyzed with various kinetic and isotherm models. The kinetic studies revealed that Pb(2+) adsorption onto spinel ferrite followed a pseudo-second order model, and the Langmuir isotherm model provided the perfect fit to the equilibrium experimental data. At different temperatures, the maximum Pb(2+) adsorption capacities calculated from the Langmuir equation were in the range of 126.5-175.4 mg/g, which can be in competition with other adsorbents. The thermodynamic results showed that the spinel ferrite could spontaneously and endothermically adsorb Pb(2+) from aqueous solution. The regeneration studies showed that spinel ferrite could be used five times (removal efficiency (%) >90%) by desorption with HNO3 reagent.

  2. Standard Methods of Analysis of Sulfochromate Etch Solution Used in Surface Preparation of Aluminum

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2012-01-01

    1.1 These methods offer a means for controlling the effectiveness of the etchant which is normally used for preparing the surface of aluminum alloys for subsequent adhesive bonding. As the etchant reacts with the aluminum, hexavalent chromium is converted to trivalent chromium; a measure of the two and the difference can be used to determine the amount of dichromate used. 1.2 The sulfochromate solution can be replenished by restoring the sodium dichromate and the sulfuric acid to the original formulation levels. The lower limit of usefulness will vary depending upon solution storage, adhesives used, critical nature of bond capability, variety of metals processed, etc. and should be determined. Replenishment will be limited to the number of times the chemical ingredients can be restored and maintained to the required levels and should be determined by the user. Sludge collecting in the bottom of a tank should be minimized by periodic removal of sludge. For some applications, the hexavalent chromium should not ...

  3. Preparation and Characterization of Biochars from Eichornia crassipes for Cadmium Removal in Aqueous Solutions.

    Directory of Open Access Journals (Sweden)

    Feng Li

    Full Text Available The study investigated the preparation and characterization of biochars from water hyacinth at 300°C to 700°C for cadmium (Cd removal from aqueous solutions. The adsorption process was dominated by oxygen-containing functional groups with irregular surfaces via esterification reactions. Furthermore, the mineral components in the biochars also contributed to Cd absorption through precipitation. Parameters such as the effects of solution pH, contact time, and initial concentration were studied. The optimum pH value was observed at 5.0, in which nearly 90% of Cd was removed. The maximum Cd adsorption capacities based on the Langmuir isotherm were calculated at 49.837, 36.899, and 25.826 mg g(-1. The adsorption processes of the biochars followed the pseudo-second-order kinetics, with the equilibrium achieved around 5 h. The biochar from E. crassipes is a promising adsorbent for the treatment of wastewater, which can in turn convert one environmental problem to a new cleaning Technology.

  4. Ce1-xLaxOy solid solution prepared from mixed rare earth chloride for soot oxidation

    Institute of Scientific and Technical Information of China (English)

    韩雪; 王亚飞; 郝红蕊; 郭荣贵; 胡运生; 蒋文全

    2016-01-01

    Ce1–xLaxOy solid solution was simply prepared using mixed rare earth chloride (RECl3·xH2O, RE=Ce, La>99%, containing unseparated Ce and La from rare earth metallurgical industry) as precursor by ultrasonic-assisted co-precipitation method with differ-ent ultrasonic frequencies (CLf,f=200, 400, 600, 800, 1000 Hz). A compared Ce1–xLaxOy solid solution (CL*) was also prepared by the same mothod with 10% less precipitant. X-ray diffraction results confirmed the formation of Ce1–xLaxOy solid solution, and the crystal structures of these catalysts were not very sensitive to ultrasonic frequency and precipitant amount. However, both of the fac-tors had obvious effect on morphology and surface area of CL, and precipitant amount seem to play a more crucial role than ultra-sonic frequency for Ce1–xLaxOy solid solution preparation. When soot and catalyst were tight contacted, the peak temperature (Tpeak) of soot oxidation and oxygen reducing temperature for CLf catalysts decreased linearly with increasing surface area. Under loose contact condition, theTpeak had obvious negative correlation with H2 consumption. It was inferred that good reducibility of the Ce1–xLaxOy solid solution favored the soot oxidation reaction. The Ce1–xLaxOy solid solution prepared from unseparated rare earth chloride showed a good soot oxidaiton activity. Controlling the preparation conditions to prepare a CL catalyst would high surface area will enhance its reducibility and activity.

  5. Formation of a 25 mol% Fe2O3-Al2O3 solid solution prepared by ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Mørup, Steen; Linderoth, Søren

    1996-01-01

    The phase transformation process of a 25 mol% Fe2O3-Al2O3 powder mixture during high-energy ball milling has been studied by x-ray diffraction and Mossbauer spectroscopy. A metastable solid solution of 25 mol % Fe2O3 in Al2O3 with corundum structure has successfully been prepared after a milling...... time of 122 h. This demonstrates that the high-energy ball milling technique is able to prepare metastable solid solutions with an extended range of compositions in ceramic/ceramic systems with a positive hear of mixing....

  6. Preparation of Al(OH)3 by ion membrane electrolysis and precipitation of sodium aluminate solution with seeds

    Institute of Scientific and Technical Information of China (English)

    LI Yuan-gao; CHEN Qi-yuan; WANG Song-sen; YIN Zhou-lan; ZHANG Ping-min

    2008-01-01

    The preparation of Al(OH)3 by the ion exchange membrane electrolysis followed by the precipitation of sodium aluminate solution with seeds was made. During the process of ion membrane electrolysis, the sodium aluminate solution is rapidly acidified and the caustic ratio (aK) is decreased due to oxygen evolution in the anodic region. And the causticity of solution is increased due to hydrogen evolution in the cathode region, producing the high concentration of caustic soda solution. Regulating the acidity of the anodic solution by controlling the electric quantity in the electrolysis and subsequent decomposing the solution, Al(OH)3 could yield with very large rate and high efficiency. The experiments also indicate that the quality of aluminum hydroxide product is greatly affected by the impurity silicon.

  7. Adsorption of cadmium from aqueous solutions on sulfurized activated carbon prepared from nut shells.

    Science.gov (United States)

    Fouladi Tajar, Amir; Kaghazchi, Tahereh; Soleimani, Mansooreh

    2009-06-15

    Low-cost activated carbon, derived from nut shells, and its modified sample have been used as replacements for the current expensive methods of removing cadmium from aqueous solutions and waste waters. Adsorption of cadmium onto four kinds of activated carbons has been studied; prepared activated carbon (PAC), commercial activated carbon (CAC), and the sulfurized ones (SPAC & SCAC). The activated carbon has been derived, characterized, treated with sulfur and then utilized for the removal of Cd(2+). Sulfurizing agent (SO(2) gas) was successfully used in adsorbents' modification process at the ambient temperature. Samples were then characterized and tested as adsorbents of cadmium. Effect of some parameters such as contact time, initial concentration and pH were examined. With increasing pH, the adsorption of cadmium ions was increased and maximum removal, 92.4% for SPAC, was observed in pH>8.0 (C(0)=100mg/L). The H-type adsorption isotherms, obtained for the adsorbents, indicated a favorable process. Adsorption data on both prepared and commercial activated carbon, before and after sulfurization, followed both the Frendlich and Langmuir models. They were better fitted by Frendlich isotherm as compared to Langmuir. The maximum adsorption capacities were 90.09, 104.17, 126.58 and 142.86 mg/g for CAC, PAC, SCAC and SPAC, respectively. Accordingly, surface modification of activated carbons using SO(2) greatly enhanced cadmium removal. The reversibility of the process has been studied in a qualitative manner and it shows that the spent SPAC can be effectively regenerated for further use easily.

  8. Preparation of optimized uranium and thorium bearing brabantite or monazite/brabantite solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Terra, O.; Dacheux, N.; Clavier, N. [Univ Paris 11, IPNO, Grp Radiochim, F-91406 Orsay, (France); Terra, O.; Audubert, F. [CEA Cadarache, DEN/DEC, F-13108 St Paul Les Durance, (France); Dacheux, N.; Clavier, N.; Podor, R. [ICMS UMR 5257, CNRS/CEA/UM2/ENSCM, F-30207 Bagnols Sur Ceze, (France); Podor, R. [Univ Nancy 1, LCSM, F-54506 Vandoeuvre Les Nancy, (France)

    2008-07-01

    The simultaneous incorporation of thorium and uranium(IV) in the rare-earth ortho-phosphates from a mixture of powdered AnO{sub 2}, (NH{sub 4})(H{sub 2}PO{sub 4}), and Ca(HPO{sub 4}).2H{sub 2}O was successfully performed, leading to the formation of single-phase Th-brabantite (Ca{sub 0.5}Th{sub 0.5}PO{sub 4}), U-brabantite (Ca{sub 0.5}U{sub 0.5}PO{sub 4}), and (Th,U)-brabantites (Ca{sub 0.5}Th{sub 0.5-y}U{sub y}PO{sub 4}). The repetition of several cycles composed of a grinding step (30 Hz, 15 min) and of a heat treatment (T=1200 degrees C, 10 h, Ar atmosphere) allowed preparation of single-phase and homogeneous compounds. The complete characterization of the samples by the means of X-Ray powder diffraction, electron probe micro-analyses, and {mu}-Raman spectrometry did not reveal either the presence of minor phases or the partial oxidation of uranium(IV) into uranyl. This study also evidenced the formation of a complete Ca{sub 0.5}Th{sub 0.5-y}U{sub y}PO{sub 4} solid solution with the associated linear decrease of a, b, and c unit cell parameters and beta increase versus the uranium mole loading. Even if the samples were found to be single phase, the significant improvement of the cation distribution in the materials was reached by the mean of the repetition of grinding/heating cycles. The same solid-state process was applied with success to the preparation of homogeneous and single-phase (Th,U)-monazite/brabantite solid solutions with general formula Ln{sub 1-2x}Ca{sub x}Th{sub x-y}U{sub y}PO{sub 4} (with 0.1 {<=} x {<=} 0.4 and y=x/5). (authors)

  9. ROTOR AND SCREW TECHNOLOGICAL SYSTEMS FOR PREPARATION OF SOLUTIONS AND CONCRETE

    Directory of Open Access Journals (Sweden)

    Belokur K. A.

    2016-04-01

    Full Text Available We have provided technical solutions to improve performance of technological systems for the preparation of solutions and concrete based on the use of screw rotors in the form of drums with helix lines formed on the perimeter as interconnect lines of his spiral surfaces. We discuss the six varieties of devices and installations for mixing, including concrete mixers, reels which are of a complicated geometric body formed by helical surfaces with variable or constant pitch and which creates screw lines in the places of their connection. In the form of screw drums, they may be conical, concave, convex, cylindrical. The experimental test was conducted on the concrete mixer drums, which are arranged one in the other. The implementation of the mixer in the form of coaxially edited two barrels provides not only a reduction in size in length, but a significant reduction in energy consumption due to the use of heat, released during the activation process of inert heating of the concrete mix as when re-mixing and concrete mix when mixing it with water and transportation. The drums of such systems is made of flat elements with the formation of the helical lines discretely spaced around the perimeter of different pitch and with different numbers directed towards each other helical surfaces. In the process of transporting the components of concrete in the internal screw drum there is active mixture of sand, gravel and cement. Thus, there is not only the destruction of lumpy, sticky components of the raw materials, but also active uniform distribution of particles of cement, sand and gravel into a homogenous mass. The implementation of the proposed technology and equipment ensures not only reduction of the dimensions of the mixer length, but also improving the quality of finished products, as well as potential cement savings of 3-5%

  10. Preparation of xerogel SiO2 from roasted iron sand under various acidic solution

    Science.gov (United States)

    Ramelan, A. H.; Wahyuningsih, S.; Ismoyo, Y. A.; Pranata, H. P.; Munawaroh, H.

    2016-11-01

    Xerogel SiO2 had been prepared from roasted iron sand through variation of Na2CO3 addition and sol-gel process under various acidic solution. Roasting treatment was carried out on the compositional variation of iron sand:Na2CO3 = 1:2; 1:1 and 2:1 at 1100 °C. While the sol-gel process was conducted at room temperature and neutralized using HCl 0.1 M and 6 M. The color characteristics of roasted iron sand shown light brown, dark brown and dark gray of the compositional variation of iron sand:Na2CO3 = 1:2; 1:1 and 2:1, respectively. In addition, the levels of thoughness increased by increasing the ratio of sand in the composition of the mixture. The best composition of roasted treatment was at a variety of iron sand:Na2SiO3 = 1:2 with 57.72% had been dissolved in hot water. The addition of Na2CO3 will influence the Na2SiO3 formation, because of the increase of Na2CO3 capable produced the iron sand decomposition product. Na2SiO3 gel had been produced after it was neutralized with certain amount of HCl solution. The neutralization was more effective if using high concentration of HCl because of the formation of gel SiO2 will be easier occurred. The results of SiO2 had been identified by the FTIR spectra, which an absorption spectra of Si-O-Si asymmetric stretching at 1098.51 cm-1, symmetric stretching of Si-O-Si at 804.35 cm-1 and the bending O-Si-O at 469.69 cm'1. The result of SiO2 content by XRF analysis is about 85.15%.

  11. Blenda de náilon-6,6/quitosana como adsorvente de corantes ácidos para reutilização das soluções de corantes tratadas em tingimentos de poliamida Nylon 6.6/chitosan blend as adsorbent of acid dyes for the reuse of treated wastewater in polyamide dyeing

    Directory of Open Access Journals (Sweden)

    Ivonete O. Barcellos

    2008-09-01

    Full Text Available A água é usada na indústria têxtil como veículo para os produtos químicos em geral e corantes utilizados no processo de tingimento e beneficiamento de fibras. Neste trabalho estudou-se a reutilização de rejeitos líquidos de tingimentos de tecidos de náilon 6,6 (PA 66, tratados pelo processo de adsorção, com uma blenda de PA 6,6/quitosana (80/20, na forma de flocos. Para a produção de rejeitos líquidos, realizaram-se tingimentos de tecidos de PA 66 com os corantes ácidos Yellow Erionyl RXL, Red Erionyl A-3B e Navy Blue Erionyl R. A eficiência da remoção da cor variou entre 97-98%, com exceção dos rejeitos dos tingimentos com o corante Yellow Erionyl RXL, onde se atingiu apenas eficiências de 65 e 72% para os rejeitos com e sem auxiliares têxteis, respectivamente. A reutilização dos rejeitos tratados estudou-se em tingimentos de tecidos de malha de poliamida 6,6 com os mesmos corantes. Os valores de ΔE (diferença de cor referente a tingimento padrão com água destilada de tingimentos em cores claras e médias, variaram de 0,24 a 1,05 (para os rejeitos de monocromia e 0,71 a 1,07 (para os rejeitos de tricromia, e são compatíveis com os padrões industriais (ΔE Water is used in the textile industry, mainly, as vehicle for chemicals and dyes used in the dyeing and finishing processes of textile fibers. In this work we studied the reuse of wastewater generated in the dyeing of nylon 6.6 (PA6.6 fabrics and treated by adsorption process with nylon 6.6/chitosan (80/20 blend flakes was studied. To produce the wastewater PA 6.6 fabrics were dyed with the acid dyes Yellow Erionyl RXL, Red Erionyl A-3B and Navy Blue Erionyl R. The efficiency in color removal of the adsorption process varied between 97-98%, with exception of the effluents from Yellow Erionyl RXL dyeing, where only efficiencies of 65% (wastewater with auxiliaries and 72% (without auxiliaries were obtained. The reuse of the treated wastewater was studied in dyeing

  12. Preparation of SrZrO3 Thermal Barrier Coating by Solution Precursor Plasma Spray

    Science.gov (United States)

    Li, Xinhui; Ma, Wen; Wen, Jing; Bai, Yu; Sun, Li; Chen, Baodong; Dong, Hongying; Shuang, Yingchai

    2017-02-01

    The solution precursor plasma spray (SPPS) process is capable of depositing highly durable thermal barrier coatings (TBCs). In this study, an aqueous chemical precursor feedstock was injected into the plasma jet to deposit SrZrO3 thermal barrier coating on metal substrate. Taguchi design of experiments was employed to optimize the SPPS process. The thermal characteristics and phase evolution of the SrZrO3 precursor, as well as the influence of various spray parameters on the coating deposition rate, microhardness, microstructure, and phase stability, were investigated. The experimental results showed that, at given spray distance, feedstock flow rate, and atomization pressure, the optimized spray parameters were arc current of 600 A, argon flow rate of 40 L/min, and hydrogen flow rate of 10 L/min. The SrZrO3 coating prepared using the optimized spray parameters had single-pass thickness of 6.0 μm, porosity of 18%, and microhardness of 6.8 ± 0.1 GPa. Phase stability studies indicated that the as-sprayed SrZrO3 coating had good phase stability in the temperature range from room temperature to 1400 °C, gradually exhibiting a phase transition from t'-ZrO2 to m-ZrO2 in the SrZrO3 coating at 1450 °C with increasing time, while the SrZrO3 phase did not change.

  13. Preparation, Structural and Dielectric Properties of Solution Grown Polyvinyl Alcohol(PVA) Film

    Science.gov (United States)

    Nangia, Rakhi; Shukla, Neeraj K.; Sharma, Ambika

    2017-08-01

    Flexible dielectrics with high permittivity have been investigated extensively due to their applications in electronic industry. In this work, structural and electrical characteristics of polymer based film have been analysed. Poly vinyl alcohol (PVA) film was prepared by solution casting method. X-ray diffraction (XRD) characterization technique is used to investigate the structural properties. The semi-crystalline nature has been determined by the analysis of the obtained XRD pattern. Electrical properties of the synthesized film have been analysed from the C-V and I-V curves obtained at various frequencies and temperatures. Low conductivity values confirm the insulating behaviour of the film. However, it is found that conductivity increases with temperature. Also, the dielectric permittivity is found to be higher at lower frequencies and higher temperatures, that proves PVA to be an excellent dielectric material which can be used in interface electronics. Dielectric behaviour of the film has been explained based on dipole orientations to slow and fast varying electric field. However further engineering can be done to modulate the structural, electrical properties of the film.

  14. PHASE STRUCTURE AND COMPATIBILITY OF LADDERLIKE POLYPHENYLSILSESQUIOXANE (PPSQ)/POLYCARBONATE (PC) BLENDS PREPARED BY SOLUTION CASTING

    Institute of Scientific and Technical Information of China (English)

    Gui-zhi Li; Liang-he Shi

    1999-01-01

    Blends of PC and PPSQ (A) with high Mw and good ladderlike regularity or PPSQ(B) with low Mw and more defective Si-atoms in its structure have been prepared by solution casting. The dispersed spheres (PPSQ(A)-rich) are unevenly dispersed in the continuous PC-rich phase and there is no phase-inversion as PPSQ(A) content increases when the percentage of PPSQ(A) is not more than70%. PPSQ(B)-rich spheres are evenly dispersed in the continuous phase (PC-rich) and phaseinversion occurs when PPSQ(B) percentage is up to 70%. Tg of PPSQ(A)/PC or PPSQ(B)/PC at some compositions are lower than that of pure PC due to the enlarged free-volume of PC-rich phase because some spheres of rigid PPSQ chains are included in the PC-rich phase. PC and PPSQ(A) or PPSQ(B)are partially compatible. The compatibility of PC and PPSQ(B) is better than that of PC and PPSQ(A)with high Mw and good ladderlike regularity. Heat history has some influence on the TgS and compatibility of PPSQ(A)/PC and PPSQ(B)/PC blends.

  15. LiFePO4 doped with magnesium prepared by hydrothermal reaction in glucose solution

    Institute of Scientific and Technical Information of China (English)

    Xiu Qin Ou; Guang Chuan Liang; Jin Sheng Liang; Sheng Zhao Xu; Xia Zhao

    2008-01-01

    Lithium iron phosphate (LiFePO4) doped with magnesium was hydrothermally synthesized from commercial LiOH, FeSO4, H3PO4 and MgSO4 with glucose as carbon precursor in aqueous solution. The samples were characterized by X-ray powder diffraction, scanning electron microscopy and constant charge-discharge cycling. The results show that the synthesized powders have been in situ coated with carbon precursor produced from caramel reaction of glucose. At ambient temperature (28±2℃, the electrochemical performances of LiFePO4 prepared exhibit the high discharge capacity of 135 mAh g(-1) at 5C and good capacity retention of 98% over 90 cycles. The excellent electrochemical performances should be correlated with the intimate contact between carbon and LiFePO4 primary and secondary particles, resulting from the in situ formation of carbon precursor/carbon, leading to the increase in conductivity of LiFePO4.

  16. Ciprofloxacin adsorption from aqueous solution onto chemically prepared carbon from date palm leaflets.

    Science.gov (United States)

    El-Shafey, El-Said Ibrahim; Al-Lawati, Haider; Al-Sumri, Asmaa Soliman

    2012-01-01

    A chemically prepared carbon was synthesized from date palm leaflets via sulphuric acid carbonization at 160 degrees C. Adsorption of ciprofloxacin (CIP) from aqueous solution was investigated in terms of time, pH, concentration, temperature and adsorbent status (wet and dry). The equilibrium time was found to be 48 hr. The adsorption rate was enhanced by raising the temperature for both adsorbents, with adsorption data fitting a pseudo second-order model well. The activation energy, Ea, was found to be 17 kJ/mol, indicating a diffusion-controlled, physical adsorption process. The maximum adsorption was found at initial pH 6. The wet adsorbent showed faster removal with higher uptake than the dry adsorbent, with increased performance as temperature increased (25-45 degrees C). The equilibrium data were found to fit the Langmuir model better than the Freundlich model. The thermodynamic parameters showed that the adsorption process is spontaneous and endothermic. The adsorption mechanism is mainly related to cation exchange and hydrogen bonding.

  17. Optimization of the design and preparation of nanoscale phospholipid bilayers for its application to solution NMR.

    Science.gov (United States)

    Puthenveetil, Robbins; Vinogradova, Olga

    2013-07-01

    Despite arduous efforts and recent technological developments structural investigation of integral membrane proteins remains a challenge. The primary deterrents include difficulties with their expression, low inherent solubility, and problems associated with existing membrane mimicking systems. A relatively new class of membrane mimetics, nanodiscs, is emerging as a promising alternative. Although nanodiscs have been proven successful for several biophysical applications, they yet remain to become the system of preferred choice for structure determination. We have hereby made nanodiscs more suitable for solution NMR applications by reducing the diameter of the self-assembly complex to its potential limit. We achieved a noticeable improvement in the quality of NMR spectra obtained for the transmembrane and cytoplasmic domains of integrin αIIb incorporated into these smaller discs rendering them susceptible for a thorough structural investigation. In addition, we also present an on-column method for a rapid, efficient, single-step preparation of protein incorporated nanodiscs at high concentrations. These discs have been fully characterized by transmission electron microscopy, dynamic light scattering, and differential scanning calorimetry.

  18. A new method for preparation of magnetite from iron oxyhydroxide or iron oxide and ferrous salt in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Kahani, S.A. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan 87317-51167 (Iran, Islamic Republic of)], E-mail: Kahani@kashanu.ac.ir; Jafari, M. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan 87317-51167 (Iran, Islamic Republic of)

    2009-07-15

    In this study, a new method is proposed for the preparation of Fe{sub 3}O{sub 4} from iron oxyhydroxides (goethite, akaganeite, lepidocrocite, feroxyhyte and ferrihydrite) or iron oxide (hematite) and ferrous salt in aqueous solution. The product is magnetite with various particle sizes. Products are characterized by X-ray powder diffraction, IR spectra and vibrating sample magnetometery.

  19. Preparation1 and utilization of wheat straw anionic sorbent for the removal of nitrate from aqueous solution

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to reduce the impact of eutrophication caused by agricultural residues (i.e. excess nitrate) in aqueous solution, economic and effective anionic sorbents are required. In this article, we prepared anionic sorbent using wheat straw. Its structural characteristics and adsorption properties for nitrate removal from aqueous solution were investigated. The results indicate that the yield of the prepared anionic sorbent, the total exchange capacity, and the maximum adsorption capacity were 350%, 2.57 mEq/g, and 2.08 mmol/g, respectively. The Freundlich isotherm mode is more suitable than the Langmuir mode and the adsorption process accords with the first order reaction kinetic rate equation. When multiple anions (SO42-, H2PO4-, NO3-, and NO2-) were present, the isotherm mode of prepared anionic sorbent for nitrate was consistent with Freundlich mode; however, the capacity of nitrate adsorption was reduced by 50%. In alkaline solutions, about 90% of adsorbed nitrate ions could be desorbed from prepared anionic sorbent. The results of this study confirmed that the wheat straw anionic sorbent can be used as an excellent nitrate sorbent that removes nitrate from aqueous solutions.

  20. Procedure for obtaining an extract rich in triterpenic acids from solutions from the process of preparation of table olives

    OpenAIRE

    2008-01-01

    [EN] Procedure for obtaining an extract having a high proportion of triterpenic acids, preferably of oleanolic and maslinic acids, from the solutions obtained in the process of preparation of table olives. Furthermore the invention refers to the extract obtained through said procedure and to application thereof in the food, cosmetic or pharmaceutical industries.

  1. Strain effects in Nb3Al multifilamentary conductors prepared by phase transformation from bcc supersaturated-solid solution

    NARCIS (Netherlands)

    Takeuchi, T.; Iijima, Y.; Inoue, K.; Wada, H.; Haken, ten B.; Kate, ten H.H.J.; Fukuda, K.; Iwaki, G.; Sakai, S.; Moriai, H.

    1997-01-01

    Strain effects on critical current densities have been examined for conductors containing nearly stoichiometric Nb3Al filaments with fine grains. The Nb3Al phase in these multifilamentary conductors are prepared by phase transformation from supersaturated Nb(Al) bcc solid solution and show high-fiel

  2. Effects of Temperature and Method of Solution Preparation on the Performance of a Typical Red Mud Flocculent

    Science.gov (United States)

    Ferland, Pierre; Malito, John T.; Phillips, Everett C.

    Alcan International Ltd. in collaboration with Ondeo Nalco Company have carried out a fundamental study on the dissolution and performance of a 100% anionic polymer. The effects of method of preparation, solvent composition, temperature and exposure time on flocculent activity under conditions relevant to both atmospheric and pressure decantation were investigated. Flocculent activity was determined using static and dynamic settling tests, and the results were correlated with the reduced specific viscosity (RSV). For any given method of preparation of the flocculent solutions (makeup/dilution) the RSV tended to decrease with increasing solution ionic strength, independent of ionic speciation. While a significant loss in flocculent activity occurred with long exposure of the solution to high temperature, only a minor loss occurred in the short time required to flocculate and settle the mud in a decanter operating at 150 °C. Recent results in an actual plant pressure decanter appear to validate this conclusion.

  3. Preparation and Characterization of Micronized Artemisinin via a Rapid Expansion of Supercritical Solutions (RESS Method

    Directory of Open Access Journals (Sweden)

    Xiaonan Zhang

    2012-04-01

    Full Text Available The particle sizes of pharmaceutical substances are important for their bioavailability. Bioavailability can be improved by reducing the particle size of the drug. In this study, artemisinin was micronized by the rapid expansion of supercritical solutions (RESS. The particle size of the unprocessed white needle-like artemisinin particles was 30 to 1200 µm. The optimum micronization conditions are determined as follows: extraction temperature of 62 °C, extraction pressure of 25 MPa, precipitation temperature 45 °C and nozzle diameter of 1000 μm. Under the optimum conditions, micronized artemisinin with a (mean particle size MPS of 550 nm is obtained. By analysis of variance (ANOVA, extraction temperature and pressure have significant effects on the MPS of the micronized artemisinin. The particle size of micronized artemisinin decreased with increasing extraction temperature and pressure. Moreover, the SEM, LC-MS, FTIR, DSC and XRD allowed the comparison between the crystalline initial state and the micronization particles obtained after the RESS process. The results showed that RESS process has not induced degradation of artemisinin and that processed artemisinin particles have lower crystallinity and melting point. The bulk density of artemisinin was determined before and after RESS process and the obtained results showed that it passes from an initial density of 0.554 to 0.128 g·cm−3 after the processing. The decrease in bulk density of the micronized powder can increase the liquidity of drug particles when they are applied for medicinal preparations. These results suggest micronized powder of artemisinin can be of great potential in drug delivery systems.

  4. Flammability and Mechanical Property of Nylon6 Composite Containing Dihydrogen Phosphate Anion-intercalated Layered Double Hydroxides%插层改性水滑石对尼龙6阻燃及力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    刘喜山; 谷晓昱; 侯慧娟; 董明哲; 江玉; 张胜

    2013-01-01

    The non-halogen flame retarded PA6 composite containing Mg-Al-CO2-3 layered double hydroxides ( CO3-LDHs) and Mg-Al- H2PO4- layered double hydroxides ( H2PO4-LDHs) which was modified by an anion exchange method were prepared. X-ray diffraction ( XRD) and Fourier transform infrared spectroscopy ( FTIR) were used to characterize the structures of CO3-LDHs and H2PO4-LDHs. The XRD and FTIR results showed that the CO3 was successfully replaced by H2PO4 . Static mechanics test and Limiting oxygen index (LOI) and thermal gravimetric (TG) were used to characterize the mechanical property, flammability and thermal behavior of PA6 composite. It was found that the obtained composite displayed not only significant improvement in thermal stability, but also enhancement in flammability. The fire performance and tensile strength of PA6 containing H2PO4-LDHs were superior to that of PA6 containing CO3-LDHs with the same loading. The mechanism had been proposed;the lamellar structure of LDH to protect the PA6 chains;the release of the constituent water in LDH to dilute the flammable gases and decrease the temperature;the replaced H2PO4 into LDHs molecules could promote the char formation during burning process.%以尼龙6(PA6)为基体,分别用镁铝-碳酸根水滑石(CO3-LDHs)和磷酸二氢根插层改性后的镁铝水滑石(H2PO4-LDHs)作为阻燃剂,制备了PA6/CO3-LDHs和PA6/ H2PO4-LDHs无卤阻燃复合材料.通过红外光谱(FTIR)、X射线衍射(XRD)对CO3-LDHs及H2PO4--LDHs进行了结构表征,结果表明:H2PO4-成功插层进入到层间取代了CO32-.通过静态力学测试、极限氧指数(LOI)和垂直燃烧等级(UL-94)的测试,研究了水滑石对材料力学性能以及阻燃性能的影响.结果表明:H2PO4-LDHs更有利于加强PA6阻燃性能和热稳定性,并能在一定程度上提高材料的力学性能.提出了LDH的存在对PA6复合材料燃烧过程的影响机理:水滑石的层状结构能够保护分子链;层间水和结构水的释

  5. Application of High-Flow Nylon 6 on Glass Fiber Reinforced Nylon 66 System%高流动性PA6在GF增强PA66体系中的应用

    Institute of Scientific and Technical Information of China (English)

    黄自华; 杨克俭; 胡天辉; 王文志; 姜其斌

    2014-01-01

    Taking nylon (PA) 66 and high-flow PA6 as martix resin,PA66/high-flow PA6/glass fiber (GF) composites were prepared by melt blending (the mass fraction of GF in the composite is 40%),and effects of the high-flow PA6 content on the crystallization and melting behaviours,heat deformation temperature (HDT),melt flow rate (MFR),surface performances and mechanical properties of the composites were studied. The results show that when the mass ratio of high-flow PA6 and PA66≤1/4, the crys-tallization and melting behaviours of the composites are similar with PA66,and HDT decreases slightly with the increase of the high-flow PA6 content. MFR increases obviously with the increase of the high-flow PA6 content. When the mass ratio of high-flow PA6 and PA66 is 1/4,the problem of floating fiber on the composite part surface is solved,and comparing with the condition of unadding high-flow PA6,the tensile and flexural strength of the composite have no change basically,but the Charpy and Cantilever notched impact strength increase by 17.6%and 16.4%respectively,MFR is 18.3 g/10 min and increases by 100%, which indicate that the composite at this high-flow PA6 content has best comprehensive properties.%以尼龙(PA)66和高流动性PA6为基体树脂,采用熔融共混方法制备了PA66/高流动性PA6/GF复合材料,考察了高流动性PA6用量对复合材料的结晶熔融行为、热变形温度(HDT)、熔体流动速率(MFR)、表面性能和力学性能的影响。结果表明,在GF质量分数为40%的情况下,当高流动性PA6用量不高于基体树脂总质量的20%时,复合材料表现出PA66的结晶熔融行为特征,HDT随高流动性PA6用量的增加略有下降;随高流动性PA6用量增加,复合材料的MFR显著提升;当高流动性PA6用量达到基体树脂总质量的20%时,复合材料制品表面浮纤问题得到解决,此时复合材料的拉伸和弯曲强度与未加高流动性PA6时相当,简支梁和悬臂梁缺口

  6. Preparation of Ultrafine Fe-Pt Alloy and Au Nanoparticle Colloids by KrF Excimer Laser Solution Photolysis.

    Science.gov (United States)

    Watanabe, Masato; Takamura, Hitoshi; Sugai, Hiroshi

    2009-03-10

    We prepared ultrafine Fe-Pt alloy nanoparticle colloids by UV laser solution photolysis (KrF excimer laser of 248 nm wavelength) using precursors of methanol solutions into which iron and platinum complexes were dissolved together with PVP dispersant to prevent aggregations. From TEM observations, the Fe-Pt nanoparticles were found to be composed of disordered FCC A1 phase with average diameters of 0.5-3 nm regardless of the preparation conditions. Higher iron compositions of nanoparticles require irradiations of higher laser pulse energies typically more than 350 mJ, which is considered to be due to the difficulty in dissociation of Fe(III) acetylacetonate compared with Pt(II) acetylacetonate. Au colloid preparation by the same method was also attempted, resulting in Au nanoparticle colloids with over 10 times larger diameters than the Fe-Pt nanoparticles and UV-visible absorption peaks around 530 nm that originate from the surface plasmon resonance. Differences between the Fe-Pt and Au nanoparticles prepared by the KrF excimer laser solution photolysis are also discussed.

  7. Preparation of Ultrafine Fe–Pt Alloy and Au Nanoparticle Colloids by KrF Excimer Laser Solution Photolysis

    Directory of Open Access Journals (Sweden)

    Sugai Hiroshi

    2009-01-01

    Full Text Available Abstract We prepared ultrafine Fe–Pt alloy nanoparticle colloids by UV laser solution photolysis (KrF excimer laser of 248 nm wavelength using precursors of methanol solutions into which iron and platinum complexes were dissolved together with PVP dispersant to prevent aggregations. From TEM observations, the Fe–Pt nanoparticles were found to be composed of disordered FCC A1 phase with average diameters of 0.5–3 nm regardless of the preparation conditions. Higher iron compositions of nanoparticles require irradiations of higher laser pulse energies typically more than 350 mJ, which is considered to be due to the difficulty in dissociation of Fe(III acetylacetonate compared with Pt(II acetylacetonate. Au colloid preparation by the same method was also attempted, resulting in Au nanoparticle colloids with over 10 times larger diameters than the Fe–Pt nanoparticles and UV–visible absorption peaks around 530 nm that originate from the surface plasmon resonance. Differences between the Fe–Pt and Au nanoparticles prepared by the KrF excimer laser solution photolysis are also discussed.

  8. Method of solution preparation of polyolefin class polymers for electrospinning processing included

    Science.gov (United States)

    Rabolt, John F. (Inventor); Lee, Keun-Hyung (Inventor); Givens, Steven R. (Inventor)

    2011-01-01

    A process to make a polyolefin fiber which has the following steps: mixing at least one polyolefin into a solution at room temperature or a slightly elevated temperature to form a polymer solution and electrospinning at room temperature said polymer solution to form a fiber.

  9. Preparation and Characterization of CeO2-ZrO2 Solid Solution Ultrafine Particles Using Reversed Microemulsion

    Institute of Scientific and Technical Information of China (English)

    An Yuan; Li Li; Wang Jun; Shen Meiqing

    2005-01-01

    Ce0.6Zr0.4O2 solid solution ultrafine particle was prepared in the cyclohexane/water/OP-10/n-hexanol reversed microemulsion. The quasi-ternary phase diagram investigations showed that the system has narrow W/O type microemulison region, so it is the proper system to prepare Ce0.6Zr0.4O2 solid solution ultrafine particle. Some physical-chemical techniques such as TG/DTA, XRD, BET, and HRTEM are used to characterize the resultant powders. The results show that the fluorite cubic Ce0.6Zr0.4O2 solid solution is obtained at 400 ℃. The surface area is (146.7 m2·g-1), which is higher than the surface area for sol-gel prepared sample (59.5 m2·g-1). HRTEM images indicated that the Ce0.6Zr0.4O2 solid solution ultrafine particle is well-crystallized, narrow size distribution, less agglomeration, within mean size of 5~7 nm.

  10. 玻璃纤维增强尼龙复合材料新型增韧剂研究%Study on Novel Toughening Agent for Glass Fiber Reinforced Nylon 6

    Institute of Scientific and Technical Information of China (English)

    周旭初; 汤鑫焱; 宋克东; 胡天辉; 王文志; 黄自华

    2014-01-01

    Using maleic anhydride (MAH) grafted trans-1,4-polyisoprene (TPI-g-MAH),MAH grafted ethylene-octene copolymer(POE-g-MAH),MAH grafted ethylene-propylene-diene block copolymer (EPDM-g-MAH) and MAH grafted styrene-ethylene-butylene-styrence block copolymer (SEBS-g-MAH) as toughening agent,glass fiber (GF) with mass fraction of 15%as enhancer,a series of toughened GF reinforced nylon(PA)6 composites were prepared by twin screw extruder. The effects of the toughening agents on the mechanical properties and melt flow rate (MFR) of the toughened composites were investigated. The results show that as the content of the toughening agents increases,the tensile strength,flexural strength as well as MFR decrease but the notched impact strength increases significantly,the toughening effect of EPDM-g-MAH is the best,the effects of TPI-g-MAH and POE-g-MAH follow,and the SEBS-g-MAH is the worst of all. When the mass fraction of toughening agent is 10%,the notched impact strength of TPI-g-MAH toughened composite is the same with that of EPDM-g-MAH toughened composite,meanwhile, comparing with other toughening agent,TPI-g-MAH can minimize the decrease degrees of the tensile strength,flexural strength and MFR of the toughened composite. In summary,TPI-g-MAH has obvious toughening effect on the GF reinforced PA6 composite and gets little impact on strength and MFR,it is a new and efficient toughening agent for the GF reinforced PA6 composite.%以马来酸酐接枝反式-1,4-聚异戊二烯(TPI-g-MAH),马来酸酐接枝乙烯–辛烯共聚物(POE-g-MAH)、马来酸酐接枝三元乙丙橡胶(EPDM-g-MAH)和马来酸酐接枝氢化苯乙烯–丁二烯–苯乙烯共聚物(SEBS-g-MAH)为增韧剂,以质量分数为15%的玻璃纤维(GF)为增强剂,通过双螺杆挤出机制备了一系列增韧型GF增强尼龙(PA)6复合材料,研究了增韧剂种类及含量对复合材料力学性能和熔体流动速率(MFR)的影响。结果表明,随着增韧剂含量的增加,

  11. Preparation and Characterization of Coating Solution Based on Waterborne Polyurethane Dispersion containing Fluorine for Primer on Electro Galvanized Steel Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Chung Keun; Lim, Sung Hyung [Buhmwoo Institute of Technology Research, Hwaseong (Korea, Republic of)

    2015-10-15

    The purpose of this research was to synthesize fluorine modified waterborne polyurethane dispersion (F-WPU) by soap-free (internal emulsifier) emulsion polymerization techniques, to prepare coating solution based on fluorine modified waterborne polyurethane dispersion (F-WPU) and to compare the chemical and thermo-mechanical properties on the electrogalvanized steel sheet. Environmentally friendly F-WPU was prepared with a fluorinated polyol containing 60 wt% of fluorine. There are various ways of combining a wide variety of fluorinated polyols and diisocyanate to exhibit novel properties of waterborne polyurethane dispersion. Components of coating solution were largely divided into 4 kinds i.e., F-WPU, acrylic emulsion, silane coupling agent, and colloidal silicate. F-WPU coating solution on the electro-galvanized steel sheet showed excellent properties of corrosion resistance, alkali resistance and heat resistance, as compared to other coating solutions using a general waterborne resin. The F-WPU coating solution's reliable effects are possibly due to the fluorine atoms incorporated even in a small amount of F-WPU.

  12. 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.

  13. CTEPP STANDARD OPERATING PROCEDURE FOR PREPARATION OF SURROGATE RECOVERY STANDARD AND INTERNAL STANDARD SOLUTIONS FOR POLAR TARGET ANALYTES (SOP-5.26)

    Science.gov (United States)

    This SOP describes the method used for preparing surrogate recovery standard and internal standard solutions for the analysis of polar target analytes. It also describes the method for preparing calibration standard solutions for polar analytes used for gas chromatography/mass sp...

  14. Characterization and Electrochemical Properties of LiMn2O4 Thin Films Prepared by Solution Deposition

    Institute of Scientific and Technical Information of China (English)

    WU Xianming; HE Zeqiang; XU Mingfei; LI Xinhai; XIAO Zhuobing

    2006-01-01

    LiMn2O4 thin films were prepared by solution deposition using lithium acetate and manganese acetate as raw materials. The phase constitution and surface morphology were observed by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the thin films were studied by cyclic voltammetry, charge-discharge experiments and impedance spectroscopy in 1 mol·L-1 LiPF6/EC-DMC solution using lithium metal as both the counter and reference electrodes. The films prepared by this method are of spinel phase. The lattice parameter increases with the annealing temperature and annealing time. The film annealed at 750 ℃ for 30 minutes has the highest capacity of 34.5 μAh·cm-2·μm-1, and its capacity loss per cycle is 0.05% after being cycled 100 times.

  15. Can mothers safely prepare labon-gur salt-sugar solution after demonstration in a diarrhoeal hospital?

    DEFF Research Database (Denmark)

    Islam, M A; Kofoed, Poul-Erik; Begum, S

    1992-01-01

    Home-based salt-sugar solution (SSS) prepared with labon (locally produced sea salt) and gur (unrefined brown sugar) has been recommended as a cheap, locally available and a simple tool to prevent and treat diarrhoeal dehydration. Preparation of labon-gur SSS is demonstrated to the patients...... and the attendants at ICDDR, Bangladesh. To evaluate performances, 150 mothers were asked to measure labon and gur by finger pinch and first method and 100 mothers measured half a seer of water to prepare labon-gur SSS, shortly after the demonstration sessions. 4.0% of the samples exceeded the upper safety limit...... this knowledge. Our study suggests that demonstration of home-based SSS in a diarrhoeal hospital may positively affect health education and that health personnel should actively participate in increasing health awareness....

  16. Preparation and Photocatalytic Properties of Ti1-xZrxO2 Solid Solution

    Institute of Scientific and Technical Information of China (English)

    GAO,Bi-Fen; MA,Ying; CAO,Ya-An; GU,Zhan-Jun; ZHANG,Guang-Jin; YAO,Jian-Nian

    2007-01-01

    A series of Ti1-xZrxO2 materials were synthesized through a multistep sol-gel process.The structural characteristics were investigated using X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS)and Raman measurements.The experimental results showed that a solid solution could be obtained at low Zr/(Ti+Zr)molar ratios(x≤0.319).Raman measurements exhibited that the presence of zirconium in the solid solutions greatly retarded the amoorphous-anatase and anatase-rutile transitions.The diffuse reflectance UV-Vis spectra revealed that the bandgap of the solid solution was enlarged gradually with the increment of incorporated zirconium content.The Til-xZrxO2solid solutions exhibited higher photocatalytic activity than pure TiO2 for the degradation of 4-chlorophenol aqueous solution.

  17. Simulation of nylon 6 polymerization in tubular reactors with recycle

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, S.K.; Kunzru, D.; Kumar, A.; Agarwal, K.K.

    1983-05-01

    In the hydrolytic polymerization of epsilon-caprolactam, the ring opening of the monomer is much slower than the polyaddition reaction. Hence, the mixing of aminocaproic acid to the feed results in a faster conversion of the monomer. Industrially, this fact is exploited by using a recycle stream. An isothermal plug flow reactor (PFR) with a recycle is simulated in this study, using two techniques: the method of successive substitutions and Wegstein's method. It is found that, under certain operating conditions, the use of a recycle stream gives higher monomer conversions and lower cyclic dimer concentrations than either a PFR or a homogeneous continuous flow stirred tank reactor (HCSTR), with the degree of polymerization almost the same as that obtained in an HCSTR, and thus offers a considerable advantage. However, when a recycle reactor is coupled with a subsequent flashing operation and a finishing reactor, these advantages are considerably reduced.

  18. Application of Intrared Absorbers to Nylon 6,6

    Science.gov (United States)

    1974-07-01

    The dyeing procedures, Appendix III, all utilized 40:1 liquor -cloth ratios at boiling temperatures. The in- frared absorbers were applied at 0.2...s were adjusted by acetic acid or ammonia . - -■■-■ ■ - - - — ...—n . <<af-’"’"" >-T—■"— »inmmn Table I Reflectance of Cyasorb IR 99 Absorbers...a formulation of dyes that approach the ideal camouflage curve is to search for acid dyes with strong infrared absorption bands. The spectra of

  19. Green Production Technology of the Monomer of Nylon-6: Caprolactam

    Directory of Open Access Journals (Sweden)

    Baoning Zong

    2017-06-01

    Full Text Available After two decades’ endeavor, the Research Institute of Petroleum Processing (RIPP has successfully developed a green caprolactam (CPL production technology. This technology is based on the integration of titanium silicate (TS-1 zeolite with the slurry-bed reactor for the ammoximation of cyclohexanone, the integration of silicalite-1 zeolite with the moving-bed reactor for the gas-phase rearrangement of cyclohexanone oxime, and the integration of an amorphous nickel (Ni catalyst with the magnetically stabilized bed reactor for the purification of caprolactam. The world’s first industrial plant based on this green CPL production technology has been built and possesses a capacity of 200 kt·a−1. Compared with existing technologies, the plant investment is pronouncedly reduced, and the nitrogen (N atom utilization is drastically improved. The waste emission is reduced significantly; for example, no ammonium sulfate byproduct is produced. As a result, the price difference between CPL and benzene drops. In 2015, the capacity of the green CPL production technology reached 3 × 106 t·a−1, making China the world’s largest CPL producer, with a global market share exceeding 50%.

  20. Preparation and Characterization of Palmitoyl Grafted Cellulose Nano Absorbent for the Efficient Adsorption of Pyrene from Aqueous Solution.

    Science.gov (United States)

    Jadhav, Arvind H; Mai, Xuan Thang; Appiah-Ntiamoah, Richard; Lee, Hanyeong; Momade, Francis W Y; Seo, Jeong Gil; Kim, Hern

    2015-10-01

    Palmitoyl grafted modified cellulose were prepared by simple chemical grafting method and applied as nano adsorbent for removal of pyrene from aqueous solution. The chemical properties and morphology of prepared nano-adsorbent were characterized by FT-IR, XRD, SEM, EDX, TGA, and contact angle. Results showed that palmitoyl successfully grafted on the surface of cellulose and possess effective organic functional groups for the adsorption of pyrene from aqueous solution. The adsorption performance of modified cellulose was significantly improved toward pyrene in aqueous solution. It is worthy to note that 0.25 g of palmitoyl grafted cellulose (PMC) removed 92% pyrene compared to unmodified cellulose which adsorbed 36% pyrene from 1.65 ppm aqueous solution of pyrene in very short contact time at room temperature. Results showed that, presence of various organic functional groups from palmitoyl chains grafted on cellulose backbone affected to pyrene removal. After completion of adsorption phenomenon nano-adsorbent can be removed by simply filtration process and reused several times. The adsorption capacity was studied under different experimental conditions and their effects on adsorption such as temperature, pH, and contact time were also studied. The kinetics and isotherms of material were also determined.

  1. Effective removal of tetracycline from aqueous solution using activated carbon prepared from tomato (Lycopersicon esculentum Mill.) industrial processing waste.

    Science.gov (United States)

    Sayğılı, Hasan; Güzel, Fuat

    2016-09-01

    Activated carbon (TAC) prepared under optimized conditions with ZnCl2 activation from a new precursor; tomato industrial processing waste (TW), was applied as an adsorbent to remove tetracycline (TC) from aqueous solution. The factors (TAC dosage, initial TC concentration, contact time, ionic strength and solution temperature) affecting the adsorption process were examined at natural pH (5.7) of TAC-TC system in aqueous solution. Kinetic data was found to be best complied by the pseudo-second order model. The isotherm analysis indicated that the equilibrium data could be represented by the Langmuir model. The maximum adsorption capacity was identified as 500.0mgg(-1) at 308K.

  2. Comparative study of the various methods of preparation of silicate solution and its effect on the geopolymerization reaction

    Science.gov (United States)

    Essaidi, N.; Laou, L.; Yotte, S.; Ulmet, L.; Rossignol, S.

    This paper is based on the characterization of synthesized geopolymer binders based on either powder or solution silicate, and the amount of water contained in synthesized binders is determined to evaluate their possibility to coat a brick. The structural evolution of the formed geopolymers was investigated using FTIR spectroscopy. The mechanical properties were evaluated using compression tests. The structural evolution ensured that the solutions prepared from silicate powder or liquid had different degrees of polymerization, which modified the polycondensation reaction of the mixture. Nevertheless, the use of aluminosilicate solutions based on powder or liquid display similar behavior in a polycondensation reaction. The obtained materials show good mechanical properties, and it is possible to deposit this binder on the brick depending on the water content.

  3. [Preparation and immunological evaluation of oral solution of egg yolk-derived hepatitis B virus-specific transfer factor].

    Science.gov (United States)

    Xu, Yanping; Zhang, Qing; Zhan, Xuejun; Xie, Daze; Dai, Ge; Yang, Hui

    2013-12-01

    To prepare the oral solution of egg yolk hepatitis B virus (HBV)-specific transfer factor (EYHBV-TF) and evaluate its immunological activity as an immune regulator against hepatitis B. From hens immunized with the Hepatitis B vaccine the egg yolk was isolated to extract the specific transfer factor EYHBV-TF, and its physicochemical properties were examined. Leukocyte adhesion inhibition test (LAI) was performed to detect the immunogenic activity of EYHBV-TF. The solution of EYHBV-TF was then administered orally in normal mice, and the specific cellular immune activity induced was assayed with delayed type skin hypersensitivity test (DTH), with the non-specific immune activity assessed with immune organ index. The immune responses induced by oral EYHBV-STF solution were compared with those by EYHBV-STF injection and by different dosages (injection and oral) of porcine spleen HBV-specific transfer factor (PSHBV-STF), porcine spleen nonspecific transfer factor, and egg yolk extracts from non-immunized hens. The prepared EYHBV-STF oral solution, which met the standards for biological products, could inhibit leukocyte adhesion in vitro and significantly enhance mouse foot pad swelling, demonstrating its capability of transferring antigen-specific delayed type hypersensitivity reactions to naive recipient. EYHBV-STF oral solution also significantly improved the immune organ index in mice (P<0 01) with similar effects to those caused by EYHBV-STF injections and by PSHBV-STF injection and oral solution. Orally administered EYHBV-STF and EYHBV-STF injection both possess hepatitis B antigen-specific cellular immune activity and can significantly enhance specific cellular immune responses.

  4. Surelease or organic solution of ethylcellulose in preparation of sustained release theophylline micromatrices or matrices using spray drying technique.

    Science.gov (United States)

    Afrasiabi Garekani, Hadi; Sedighi, Samira; Sadeghi, Fatemeh

    2015-03-01

    This study evaluated ethylcellulose (EC) in two forms in preparation of sustained release theophylline microparticles using spray drying. Spray dried (SD) samples at different drug:polymer ratios were prepared using Surelease (SDaq) or organic solutions of ethylcellulose (SDor). Properties of particles (yield, particle morphology, size distribution and release profiles) were examined. Differential scanning calorimetry (DSC) and infrared spectroscopy (IR) studies were performed to track polymorphic changes and/or drug polymer interactions. SD samples were compressed and crushing strengths and release profiles were determined. The yields were in the range of 55-70%. The SD samples were nearly spherical with numerous fine particles attached to their surfaces. The SDor samples showed the smallest particle size. No polymorphism or drug-polymer interaction was observed. Uncompressed SDaq samples showed inadequate sustained release of drug compared to SDor samples. Surelease content did not affect drug release from SDaq samples. Tablets prepared from SDaq were softer and showed some plasticity, while those prepared from SDor exhibited higher crushing strengths. Tablets prepared from SDaq showed sustained release properties while the release of drug from compressed SDor samples were too slow. Overall Surelease was unable to sustain release of theophylline from SDaq microparticles, however, in compacted form showed more appropriate drug release than compacted SDor.

  5. APPLICATION OF NYLON6 CHIPS PRODUCED ON 15 kt/a DOMESTIC VK TUBE TO HIGH-SPEED SPINNING%15 kt/a国产锦纶6连续聚合装置切片高速纺丝工艺探讨

    Institute of Scientific and Technical Information of China (English)

    廖扬; 张学平; 徐姝

    2001-01-01

    介绍了国产15 kt/a聚合装置生产的YH500C锦纶6有光切片在高速纺装置上的 生产情况 ,调整纺丝温度,控制侧吹风温度20℃,速度0.4~0.5 m/s,RH为65%~75%,上油率为 0.5%~0.8%,调整冷却集束点位置,选择合理的聚氨酯摩擦盘和热箱温度,则可生产出 质量稳定的155 dtex/48 f锦纶有光DTY产品。%The production situation of YH500C bright chips produced o n 15 kt/a domestic VK tube applied to high -speed spinning was introduced. The produced chips had consistent quality and a bsolutely suited to high-speed spinning when the process parameters, such as sp inning temperature, spinpack filter medium, collection position and hot box temp erature etc., were well controlled. The consistent-quality 155 dtex/48 f bright nylon6 DTY can be obtained if the fore and after spinning process was optimized as followed: cross air blow temperature 20℃, air speed 0.4~0.5 m/s, RH 6 5%~75%, oil pick-up 0.5%~0.7% and rational choice of polyurethane friction di sc and hot box temperature.

  6. Preparation and characterization of chitosan-clay nanocomposites for the removal of Cu(II) from aqueous solution.

    Science.gov (United States)

    Azzam, Eid M S; Eshaq, Gh; Rabie, A M; Bakr, A A; Abd-Elaal, Ali A; El Metwally, A E; Tawfik, Salah M

    2016-08-01

    In the present study, chitosan assembled on gold and silver nanoparticles were prepared and characterized by UV-vis, TEM, EDX and DLS techniques. The nanocomposites chitosan (Ch)/clay, chitosan (Ch)/AgNPs/clay and chitosan (Ch)/AuNPs/clay were prepared by solution mixing method and characterized by FTIR, XRD, and SEM techniques. The adsorption of copper(II) ions onto the prepared hybrid composites from an aqueous solution using batch adsorption was examined. The results showed that benefiting from the surface property of clay, the abundant amino and hydroxyl functional groups of chitosan, the adsorbent provides adequate and versatile adsorption for the Cu(II) ions under investigation. The batch adsorption experiments showed that the adsorption of the Cu(II) is considerably dependent on pH of milieu, the amount of adsorbent, and contact time. Batch adsorption studies revealed that the adsorption capacity of Cu(II) increased with increase in initial concentration and contact time with optimum pH in the range around neutral. The maximum uptake of Cu(II) ions by (Ch)/AgNPs/clay composite was found to be 181.5mg/g. The adsorption efficiency of Cu(II) ions by prepared (Ch)/AgNPs/clay and (Ch)/AuNPs/clay is bigger than that the individual chitosan (Ch)/clay composite which clarifies the role of metal nanoparticles in enhancement the adsorption characters. The study suggests that the (Ch)/AgNPs/clay hybrid composite is a promising nano-adsorbent for the removal of Cu(II) ions from aqueous solution.

  7. Electrophoretic painting on AZ31 Mg alloy pretreated in cerium conversion coating solutions prepared in ethanol-water mixtures

    Science.gov (United States)

    Van Phuong, Nguyen; Fazal, Basit Raza; Moon, Sungmo

    2017-01-01

    Electrophoretic painting (E-paint) was prepared on AZ31 Mg alloy samples pretreated in cerium conversion coating (CeCC) solutions with various ratios of ethanol and water mixture and its characteristics, adhesion and corrosion resistance were investigated. It was found that CeCC formed on AZ31 Mg alloy in a CeCC solution without ethanol was partly cracked structure and mainly consisted of Mg(OH)2/MgO, which exhibited weak adhesion with E-painting layer after water immersion test, and low corrosion resistance, as indicated by rapid formation of blisters and paint delamination during salt spray test. The addition of ethanol promoted the growth of a fine nano-crystalline CeO2 layer over the entire substrate surface. The E-paint on AZ31 pretreated in the CeCC solutions with addition of ethanol showed also improved corrosion resistance, as represented by the delayed time for paint delamination and blister formation. The E-paint layers on the CeCC layers formed in solutions containing 50-80 vol% ethanol showed stronger adhesion and better corrosion resistance than those formed on the samples treated in a non-ethanol containing CeCC solution.

  8. Preparation and adsorption properties of nano magnetite chitosan films for heavy metal ions from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Lasheen, M.R., E-mail: ragaei24@link.net [Water Pollution Research Department, Environmental Research Division, National Research Centre, 33-El Buhoth St., Dokki, Cairo, 12311 (Egypt); El-Sherif, Iman Y., E-mail: iman57us@yahoo.com [Water Pollution Research Department, Environmental Research Division, National Research Centre, 33-El Buhoth St., Dokki, Cairo, 12311 (Egypt); Tawfik, Magda E., E-mail: magdaemileta@yahoo.com [Polymers and Pigments Department, National Research Centre, 33-El Buhoth St., Dokki, Cairo, 12311 (Egypt); El-Wakeel, S.T., E-mail: shaimaa_tw@yahoo.com [Water Pollution Research Department, Environmental Research Division, National Research Centre, 33-El Buhoth St., Dokki, Cairo, 12311 (Egypt); El-Shahat, M.F., E-mail: elshahatmf@hotmail.com [Faculty of Science, Ain Shams University, Khalifa El-Maamon St., Abbasiya Sq., 11566, Cairo (Egypt)

    2016-08-15

    Highlights: • Nano magnetite–chitosan films were prepared by casting method. • The efficiency of the prepared films for removing heavy metals was investigated. • The adsorption mechanism was studied using different isotherm and kinetic models. • Films reuse and metals recovery were studied. - Abstract: Nano magnetite chitosan (NMag–CS) film was prepared and characterized with different analytical methods. X-ray diffraction (XRD) patterns confirmed the formation of a pure magnetite structure and NMag–CS nanocomposite. TEM image of the film, revealed the uniform dispersion of magnetite nanoparticles inside chitosan matrix. The adsorption properties of the prepared film for copper, lead, cadmium, chromium and nickel metal ions were evaluated. Different factors affecting the uptake behavior by the composite films such as time, initial pH and film dose were investigated. The adsorption equilibrium attained using 2 g/L of the film after 120 min of reaction. The equilibrium data were analyzed using Langmuir and Freundlich models. The adsorption kinetics followed the mechanism of the pseudo-second-order equation for all metals. The metals regenerated from films with an efficiency greater than 95% using 0.1 M ethylene diamine tetra acetic acid (EDTA) and films were successfully reused for adsorption.

  9. Liquid crystalline solutions of cellulose in phosphoric acid for preparing cellulose yarns

    NARCIS (Netherlands)

    Boerstoel, H.

    2006-01-01

    The presen thesis describes a new process for manufacturing high tenacity and high modulus cellulose yarns. A new direct solvent for cellulose has been discovered, leading to liquid crystalline solutions. This new solvent, superphosphoric acid, rapidly dissolves cellulose. These liquid crystalline s

  10. Stoichiometry-controlled high-performance LiCoO 2 electrode materials prepared by a spray solution technique

    Science.gov (United States)

    Konstantinov, K.; Wang, G. X.; Yao, J.; Liu, H. K.; Dou, S. X.

    LiCoO 2 cathode materials have been prepared by a spray-drying technique. The stoichiometry of the materials, their morphology, and the phase composition and electrochemical performance have been studied. The effects of thermal annealing and decomposition processes on the structure are discussed in detail. The changes of Li content in materials were monitored by ICP spectrometry. It was established that the decomposition of the acetates at around 450 °C is a slurry-making process that compacts the powder. It was found that well lithiated samples with good life cycle and high capacity can be prepared using acetate precursors and a spray solution technique. The morphology, grain size and texturing can be controlled by the sintering time and temperature in combination with intermediate grinding.

  11. PREPARATION AND CORROSION RESISTANCE OF NiP/TiO2 COMPOSITE FILM ON CARBON STEEL IN SULFURIC ACID SOLUTION

    Institute of Scientific and Technical Information of China (English)

    L.Z. Song; S.Z. Song; J. Zhao

    2006-01-01

    A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion behavior of the NiP/TiO2 composite film was investigated by polarization resistance measurement, anode polarization, ESEM (environmental scanning electron microscopy)and EIS (electrochemical impedance spectroscopy) measurements. Results showed that the NiP/TiO2 composite film has a good corrosion resistance in 0.5mol/L H2SO4 solution. The element valence of the composite film was characterized by XPS (X-ray photoelectron spectroscopy) spectrum, and an anticorrosion mechanism of the composite film was discussed.

  12. PREPARATION OF Co50Ni50 ULTRAFINES BY CO-REDUCTION OF SOLUTION IN PRESENCE OF POLYMER

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The reduction reaction of aqueous Co2+ -hydrazine, which cannot be conducted under the common condition, is carried out by using both of low-temperature heating and stirring. Metallic ultrafines are prepared by this method. In the presence of polyvinyl alcohol (PVA), it is absorbed on the surface of particles of the product and forms a structure of complex particle, which is favorable to the stability of the powder size distribution. Co50Ni50 magnetic alloy ultrafines with fcc-cubic system can also be prepared from Co2+ -Ni2 +hybrid solution by the same method in the presence of PVA. The effect of PVA amount on the particle size and the stability of Co50Ni50 alloy ultrafines are emphatically discussed.

  13. Impact of heating rate and solvent on Ni-based catalysts prepared by solution combustion method for syngas methanation

    Directory of Open Access Journals (Sweden)

    Zeng Yan

    2014-12-01

    Full Text Available Ni-Al2O3 catalysts prepared by solution combustion method for syngas methanation were enhanced by employing various heating rate and different solvent. The catalytic properties were tested in syngas methanation. The result indicates that both of heating rate and solvent remarkably affect Ni particle size, which is a key factor to the catalytic activity of Ni-Al2O3 catalysts for syngas methanation. Moreover, the relationship between Ni particle size and the production rate of methane per unit mass was correlated. The optimal Ni-Al2O3 catalyst prepared in ethanol at 2°C/min, achieves a maximum production rate of methane at the mean size of 20.8 nm.

  14. Stability of Melphalan in 0.9% Sodium Chloride Solutions Prepared in Polyvinyl Chloride Bags for Intravenous Injection.

    Science.gov (United States)

    Desmaris, Romain-Pacôme; Mercier, Lionel; Paci, Angelo

    2015-09-01

    Melphalan is an alkylating agent frequently used in an intravenous formulation to treat hematologic malignancies and solid tumors in both adults and children. According to the manufacturer, melphalan is stable in sterile 0.9% sodium chloride for 90 min at room temperature (RT). Several authors have studied the stability of different concentrations of melphalan; however, most were not adapted to the current manufacturing process applied in pharmaceutical centralized units. This study was conducted to determine the stability of melphalan in 0.9% sodium chloride solutions at concentrations used for intravenous injection in practice. Melphalan is commonly prepared in diluted solutions ranging from 2 to 4 mg/ml for the treatment of adult patients and at lower concentrations (down to 0.5 mg/ml) for pediatric use. Accordingly, these were the three concentrations chosen for this study. Melphalan concentrations were measured with high-performance thin-layer chromatography (HPTLC). At RT, admixtures prepared at 4 mg/ml were stable for up to 8 h without protection from light; however, at lower concentrations, such as 0.5 and 2 mg/ml, stability did not exceed 2 h. When refrigerated, melphalan was stable for 24 h at 2 mg/ml; however, at 0.5 and 4 mg/ml, the drug was not stable. Melphalan solutions present with limited stability at 0.5, 2, and 4 mg/ml and are not adapted for delayed administration in pharmaceutical centralized units. However, at 4 mg/ml and at RT, a stability of 8 h is very interesting in practice and allows sufficient time for preparation, pharmaceutical control, transport, and administration.

  15. Photoactive composite films prepared from mixtures of polystyrene microgel dispersions and poly(3-hexylthiophene) solutions.

    Science.gov (United States)

    Chen, Mu; Cui, Zhengxing; Edmondson, Steve; Hodson, Nigel; Zhou, Mi; Yan, Junfeng; O'Brien, Paul; Saunders, Brian R

    2015-11-14

    Whilst polystyrene microgels belong to the oldest family of microgel particles, their behaviours when deposited onto substrates or prepared as composites have received little attention. Because polystyrene microgels are solvent-swellable, and inherently colloidally stable, they are well suited to form composites with conjugated polymers. Here, we investigate the morphology and light absorption properties of spin coated composite films prepared from mixed dispersions of polystyrene microgels and poly(3-hexylthiophene) (P3HT) for the first time. We compare the morphologies of the composite films to spin coated microgel films. The films were studied using optical microscopy, SEM, AFM, wide-angle X-ray diffraction and UV-visible spectroscopy. The films contained flattened microgel particles with an aspect ratio of ∼10. Microgel islands containing hexagonally close packed particles were evident for both the pure microgel and microgel/P3HT composite films. The latter were electrically conducting. The composite film morphology was dependent on the microgel and P3HT concentration used for film preparation and a morphology phase diagram was constructed. The P3HT phase acted as an electrically conducting cement and increased the robustness of the films to solvent washing. The composite films were photoactive due to the P3HT component. The absorbance for the films was tuneable and increased linearly with both microgel and P3HT concentration. The results of the study should apply to other organic swellable microgel/conjugated polymer combinations and may lead to new colloidal composites for future optoelectronic applications.

  16. Preparation and Characterization of Activated Carbon from Coconut Shell – Doped Tio2 in Water Solution

    Directory of Open Access Journals (Sweden)

    Maulidiyah

    2015-12-01

    Full Text Available The objective of the study was to prepare the activated carbon material doped TiO2-P25 (P25in order to determine the interaction occured in the water medium. The method was to prepare the activated carbon from coconut shell which had been cleaned, pyrolyzed, sievedthen followed by physical activation using a thermal process. Preparation of P25 was to form structures of anatase crystals in the furnace at temperature of 500°C for 3 hours. Both materials were mixed using distilled water until sol-gel was formed. Results of characterization using SEM showed that there is interaction between the activated carbon and P25inserted in the pores of the carbon, while SEM-EDX showed the composition of carbon, titanium and oxide are 46.9%; 27.5% and 25.6%, respectively. Data from XRD showed the formation of peaks from P25 anatase crystals and the carbon. It was supported by data of Flourier Transform Infra Red (FTIR which showed the bonds of –OH; C-H; C=C; COand the O-Ti-O.

  17. Interstitial positions of tin ions in alpha-(FerichSn)(2)O-3 solid solutions prepared by mechanical alloying

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lin, Rong; Nielsen, Kurt

    1997-01-01

    The microstructure of samples of 91, 85, and 71 mol % alpha-Fe-2-O-3-SnO2. prepared by mechanical alloying, has been studied by x-ray diffraction with Rietveld structure refinements, On the basis of the structure refinements to the whole x-ray diffraction patterns for the four as-milled samples......, it is found that tin ions do not substitute iron ions in the solid solution, although this model is generally assumed in the literature. The Sn4+ ions occupy the empty octahedral holes in the lattice of the alpha-Fe2O3 phase....

  18. Adsorption of Reactive Blue 171 from Aqueous Solution using Low Cost Activated Carbon Prepared from Agricultural Solid Waste: Albizia amara

    Directory of Open Access Journals (Sweden)

    K. Anitha

    2015-07-01

    Full Text Available The adsorption of Reactive Blue 171 (Reactive Dye from aqueous solution using activated carbon prepared from Albizia amara pod shell waste as an adsorbent have been carried out. The experimental adsorption data fitted reasonably well to Langmuir and Freundlich adsorption isotherms. Kinetic parameters as a function of Initial dye concentration have been calculated and the kinetic data were substituted in Pseudo First Order, Elovich and Pseudo Second order equations. A probable explanation is offered to account for the results of kinetic study. The thermodynamic parameter enthalpy change (∆H suggests the exothermic nature of absorption of Reactive Blue 171 onto activated Albizia amara pod shell waste carbon.

  19. Advances in preparation of modified activated carbon and its applications in the removal of chromium (VI) from aqueous solutions

    Science.gov (United States)

    Deng, Z. L.; Liang, M. N.; Li, H. H.; Zhu, Z. J.

    2016-08-01

    The wastewater in which Cr(VI) is not fully treated has drawn environment researchers’ attention increasingly, due to its environmental pollution and harms to human health. Thus a high efficiency of modified activated carbon (MAC) to remove Cr(VI) has become one of the hot topics among environmental material research. This paper introduces the modification methods from the physical structure features and chemical properties of the activated carbon (AC) surface. At the same time, it briefly analyses the chemical characteristics of Cr(VI) in aqueous solutions, and on the basis of the aforementioned introduces the modification methods of the surface chemical characteristics of AC, such as: oxidation modification, reduction modification, loaded metal modification, and microwave modification. Combining studies on removing Cr(VI) from aqueous solutions by MAC in recent years, this paper anticipates the new trends of preparing MAC and the points in absorption research, offering some suggestions for future studies.

  20. Influence of Monomer Concentration on the Morphologies and Electrochemical Properties of PEDOT, PANI, and PPy Prepared from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Shalini Kulandaivalu

    2016-01-01

    Full Text Available Poly(3,4-ethylenedioxyhiophene (PEDOT, polyaniline (PANI, and polypyrrole (PPy were prepared on indium tin oxide (ITO substrate via potentiostatic from aqueous solutions containing monomer and lithium perchlorate. The concentration of monomers was varied between 1 and 10 mM. The effects of monomer concentration on the polymers formation were investigated and compared by using Fourier transform infrared spectroscopy (FTIR, Raman spectroscopy, scanning electron microscopy (SEM, cyclic voltammetry (CV, and electrochemical impedance spectroscopy (EIS measurements. FTIR and Raman spectra showed no changes in the peaks upon the increment of the concentration. Based on the SEM images, the increment in monomer concentration gives significant effect on morphologies and eventually affects the electrochemical properties. PEDOT electrodeposited from 10 mM solution showed excellent electrochemical properties with the highest specific capacitance value of 12.8 mF/cm2.

  1. The antioxidant properties of oligo sodium alginates prepared by radiation-induced degradation in aqueous and hydrogen peroxide solutions

    Science.gov (United States)

    Şen, Murat; Atik, Hanife

    2012-07-01

    In this study, the radiation-induced degradation of sodium alginates (NaAlg), having different guluronic acids (G) and mannuronic acid (M) ratios, (G/M), in aqueous and hydrogen peroxide solutions were investigated first; after that, the antioxidative properties of the oligo sodium alginates prepared were identified. Radiation degradation yield values, G(S), were determined for each irradiation condition and compared with those of the dry-state-irradiated NaAlg. The results showed that the oligo sodium alginates with M from 1000 to 3750 Da could be easily prepared by γ-irradiation of NaAlg solution in the presence of small amount of hydrogen peroxide at low doses (below 5.0 kGy) and by controlling the G/M. The antioxidant properties of the fractions with various molecular weight and G/M were evaluated by determining the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl free radical (DPPHrad ), and 50% inhibition concentrations of LF120 NaAlg, which was irradiated in aqueous solution and H2O2 solution at a dose of 2.5 kGy and having number average molecular weights of 10.2 and 3.75 kDa were found to be 10.0 and 2.5 mg/ml, respectively. The results demonstrated that its molecular weight was an important factor in controlling the antioxidant properties of NaAlg, and due to the sharp decrease in molecular weight in the case of aqueous media irradiation the effect of G/M of initial polymer became unimportant whereas the dry-state-irradiated NaAlgs behaved conversely.

  2. Preparation of Highly Pure Vanadyl Sulfate from Sulfate Solutions Containing Impurities of Iron and Aluminum by Solvent Extraction Using EHEHPA

    Directory of Open Access Journals (Sweden)

    Dan Li

    2017-03-01

    Full Text Available The preparation of highly pure vanadyl sulfate from sulfate solutions containing impurities of iron and aluminumwas investigated by solvent extraction with 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (EHEHPA and tri-n-butyl phosphate (TBP as the phase modifier. The extraction and stripping conditions of vanadium (IV and its separation from iron and aluminum were optimized. Under the optimal extraction conditions, the extraction of vanadium (IV and iron were 68% and 53%, respectively, while only 2% aluminum was extracted in a single contact, suggesting good separation of vanadium (IV from aluminum. Sulfuric acid solution was used for the stripping. Nearly 100% vanadium (IV and 95% aluminum were stripped, while only 10% iron was stripped under the optimal stripping conditions in a single contact, suggesting good separation of vanadium (IV from iron. After five stages of extraction and stripping, highly pure vanadyl sulfate containing 76.5 g/L V (IV with the impurities of 12 mg/L Fe and 10 mg/L Al was obtained, which is suitable for the electrolyte of a vanadium redox flow battery. Organic solution was well regenerated after stripping by oxalic acid solution to remove the remaining iron. The mechanism of vanadium (IV extraction using EHEHPA was also discussed based on the Fourier transform infrared spectroscopy (FT-IR analysis.

  3. Preparation of Conductive Coating Solutions by Blending Waterborne Acrylic Polyurethane Dispersion with Carbon Nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Woo Young; Yun, Dong Gu; Song, Ki Chang [Konyang University, Nonsan (Korea, Republic of)

    2013-02-15

    Waterborne polyurethane dispersion (WPUD) was synthesized from polycarbonate diol (PCD), isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as starting materials. Then, waterborne acrylic polyurethane dispersion (AUD) was synthesized by reacting the WPUD with an acrylate monomer, methyl methacrylate (MMA). Subsequently, the AUD was mixed with multi-walled carbon nanotube (MWCNT) to yield a conductive coating solution, and the mixture was coated on the polycarbonate substrate. With increasing the amount of MMA in the AUD, the pencil hardness, abrasion resistance and chemical resistance of the coating films were improved, but the electrical conductivity of the coating films was decreased. On the other hand, the pencil hardness, abrasion resistance and chemical resistance of coating films were decreased, but the electrical conductivity was enhanced with increasing the amount of MWCNT in the conductive coating solutions.

  4. The study of the antimicrobial activity of colloidal solutions of silver nanoparticles prepared using food stabilizers.

    Science.gov (United States)

    Balandin, G V; Suvorov, O A; Shaburova, L N; Podkopaev, D O; Frolova, Yu V; Ermolaeva, G A

    2015-06-01

    The bactericidal effect of colloidal solutions of silver nanoparticles based on food stabilizers, gum arabic and chitosan, against bacterial cultures of microorganisms in food production is described. The antibacterial activity of nanotechnology products containing different amounts of stabilizing additives when applied to solid pH-neutral substrates is studied. For its evaluation a method making it possible to take into account the capability of nanoparticles to diffuse in solid media was applied. Minimal inhibitory concentrations of nanoparticles used against Erwinia herbicola, Pseudomonas fluorescens, Bacillus subtilis, Sarcina flava were found. A suggestion was made concerning the influence of the spatial structure of bacteria on the antibacterial activity of colloidal solutions of silver nanoparticles. The data concerning the antibacterial activity and minimal inhibiting concentrations of nanoparticles may be used for development of products suppressing activity of microorganisms hazardous for food production.

  5. Usefulness of Activated Carbon Prepared from Industrial Wastes in the Removal of Nickel from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    R. Rajalakshmi

    2009-01-01

    Full Text Available Elimination of heavy metals like nickel from waste water is an important subject in view of public health. In the present study, an attempt has been made to study the applicability of industrial by-products as potential metal adsorbents to remove nickel from aqueous solutions and polluted water. A direct proportionality between the percentage of Ni(II removal and adsorbent dosage was noted. Maximum removal ⁄ recovery of nickel was achieved at pH range of 10-12 for all adsorbents. An optimum temperature of 40 °C for efficient removal of Ni(II was observed. The effect of nickel adsorption was affected by salinity. The adsorption isotherm data confirmed to Freundlich and Langmuir isotherms. Conformation of data to the Lagergren᾽s rate equation indicated first order kinetics. The suitability of the industrial by-products in the successful removal of nickel from aqueous solution is quite obvious from the study.

  6. Preparation of nanosized barium zirconate powder by precipitation in aqueous solution

    OpenAIRE

    Boschini, Frédéric; Guillaume, Bernard; Rulmont, André; Cloots, Rudi

    2004-01-01

    Several ways were explored to synthesize barium zirconate by soft chemistry methods in aqueous solution. In the first method the synthesis of barium zirconate was initiated by urea decomposition, through an homogeneous precipitation of barium and zirconium salts followed by a "low temperature" thermal treatment. The kinetic of the reaction and the optimum urea/cation ratio have been determined by means of X-ray diffraction and Inductive Coupled Plasma analyses. It has been demonstrated that a...

  7. Hexavalent chromium removal from aqueous solutions by a novel powder prepared from Colocasia esculenta leaves.

    Science.gov (United States)

    Nakkeeran, E; Saranya, N; Giri Nandagopal, M S; Santhiagu, A; Selvaraju, N

    2016-08-01

    In this study, batch removal of hexavalent chromium from aqueous solutions by powdered Colocasia esculenta leaves was investigated. Batch experiments were conducted to study the effects of adsorption of Cr(VI) at different pH values, initial concentrations, agitation speeds, temperatures, and contact times. The biosorbent was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectrometer analysis. The biosorptive capacity of the adsorbent was dependent on the pH of the chromium solution in which maximum removal was observed at pH 2. The adsorption equilibrium data were evaluated for various adsorption isotherm models, kinetic models, and thermodynamics. The equilibrium data fitted well with Freundlich and Halsey models. The adsorption capacity calculated was 47.62 mg/g at pH 2. The adsorption kinetic data were best described by pseudo-second-order kinetic model. Thus, Colocasia esculenta leaves can be considered as one of the efficient and cheap biosorbents for hexavalent chromium removal from aqueous solutions.

  8. CTEPP STANDARD OPERATING PROCEDURE FOR PREPARATION OF SURROGATE RECOVERY STANDARD AND INTERNAL STANDARD SOLUTIONS FOR NEUTRAL TARGET ANALYTES (SOP-5.25)

    Science.gov (United States)

    This standard operating procedure describes the method used for preparing internal standard, surrogate recovery standard and calibration standard solutions for neutral analytes used for gas chromatography/mass spectrometry analysis.

  9. How preparation and modification parameters affect PB-PEO polymersome properties in aqueous solution

    DEFF Research Database (Denmark)

    Habel, Joachim Erich Otto; Ogbonna, Anayo; Larsen, Nanna

    2016-01-01

    faster to structures extrusion, which was more pronounced at 5 mg mL−1, compared to 10, 20, and 25 mg mL−1. Our results indicate that the bilayer of SE-prepared polymersomes has a lower apparent fluidity. We also investigated the role of n-octyl-β-d-glucopyranoside (OG......), a detergent typically used for reconstitution of membrane proteins into lipid bilayers. Specifically, we compared dialysis and biobeads for OG removal to investigate the influence of these methods on bilayer conformation and polymer rearrangement following detergent removal. There was no significant...

  10. Preparation of molecularly imprinted polymer nanoparticles for selective removal of fluoroquinolone antibiotics in aqueous solution.

    Science.gov (United States)

    Tan, Feng; Sun, Daming; Gao, Jinsuo; Zhao, Qian; Wang, Xiaochun; Teng, Fei; Quan, Xie; Chen, Jingwen

    2013-01-15

    In this study, novel molecularly imprinted polymer nanoparticles (nanoMCN@MIPs) were prepared by covalent grafting of ofloxacin-imprinted polymer onto the surface of mesoporous carbon nanoparticles (MCNs). SEM analyses indicated that the prepared nanoMCN@MIPs were almost uniform, and their geometrical mean diameter was about 230 nm. The sorption behaviors of the nanoMCN@MIPs including sorption kinetics and isotherms, effect of pH, ionic strength, and cross-reactivity were investigated in detail. The adsorption capacity of the nanoparticles for ofloxacin was 40.98 mg/g, with a selectivity factor of 2.6 compared to the nonimprinted polymer nanoparticles (nanoMCN@NIPs). The feasibility of removing fluoroquinolone antibiotics (FQs) from environmental waters with the nanoMCN@MIPs was demonstrated using sea water spiked with six typical FQs (ofloxacin, gatifloxacin, balofloxcacin, enrofloxacin, norfloxacin and sarafloxacin). The nanoMCN@MIPs could be reused at least five times with removal efficiency more than 90% except for norfloxacin. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Fe-doped epitaxial YBCO films prepared by chemical solution deposition

    Institute of Scientific and Technical Information of China (English)

    Hong Zhang; Yong Zhao; Wentao Wang; Min Pan; Ming Lei

    2014-01-01

    YBa2Cu3O7-d (YBCO)-coated conductors have wide-ranging potential in large-scale applications such as superconducting maglev trains and superconducting elec-tric cables, but low current carrying capability restrains the practical application of YBCO-coated conductors at high temperatures and high magnetic fields. It is crucial to develop YBCO-coated conductors with high critical cur-rent density. In this paper, epitaxial, dense, smooth, and crack-free Fe-doped YBCO films were prepared on a LaAlO3 single crystal substrate via a fluorine-free polymer-assisted metal organic deposition method. The effects of the dilute Fe doping on microstructure and superconduc-ting character of YBCO films were investigated. The crit-ical temperature for superconducting of the Fe-doped YBCO films decreases slightly. However, the in-field critical current density of YBCO films improves with dilute Fe doping of amounts less than x=0.005, compared to the pure YBCO film. Therefore, the current carrying capability of YBCO film can improve by doping with appropriate amounts of Fe. This means that dilute Fe doping in YBCO films may be a feasible way to prepare high-performance coated conductors.

  12. Activated carbon prepared from coffee pulp: potential adsorbent of organic contaminants in aqueous solution.

    Science.gov (United States)

    Gonçalves, Maraisa; Guerreiro, Mário César; Ramos, Paulize Honorato; de Oliveira, Luiz Carlos Alves; Sapag, Karim

    2013-01-01

    The processing of coffee beans generates large amounts of solid and liquid residues. The solid residues (pulp, husk and parchment) represent a serious environmental problem and do not have an adequate disposal mechanism. In this work, activated carbons (ACs) for adsorption of organic compounds were prepared from coffee pulp by controlled temperature at different pulp/Na2HPO4 ratios (4:1, 2:1, 5:4 and 1:1). The N2 adsorption/desorption isotherms showed ACs with high quantities of mesopores and micropores and specific surface areas of 140, 150, 450 and 440 m(2)g(-1) for AC 4:1, AC 2:1, AC 5:4 and AC 1:1, respectively. The prepared material AC 5:4 showed a higher removal capacity of the organic contaminants methylene blue (MB), direct red (DR) and phenol than did a Merck AC. The maximum capacities for this AC are approximately 150, 120 and 120 mg g(-1) for MB, DR and phenol, respectively. Thus, a good adsorbent was obtained from coffee pulp, an abundant Brazilian residue.

  13. Preparation of activated carbons from Iris tectorum employing ferric nitrate as dopant for removal of tetracycline from aqueous solutions.

    Science.gov (United States)

    Li, Gang; Zhang, Dongsheng; Wang, Man; Huang, Ji; Huang, Lihui

    2013-12-01

    Ferric nitrate was employed to modify activated carbon prepared from Iris tectorum during H₃PO₄ activation and ability of prepared activated carbon for removal of tetracycline (TC) was investigated. The properties of the activated carbon samples with or without ferric nitrate, ITAC-Fe and ITAC, were measured by scanning electron microscopy (SEM), N₂ adsorption/desorption isotherms, Fourier transform infrared spectroscopy (FTIR) and Boehm's titration. The results showed that mixing with iron increased the BET surface area, total pore volume and the adsorption capacity as compared to the original carbon. FTIR and Boehm's titration suggested that ITAC-Fe was characteristic of more acidic functional groups than ITAC. Adsorption of TC on both samples exhibited a strong pH-dependent behavior and adsorption capacity reduced rapidly with the increasing solution pH. The adsorption kinetics agreed well with the pseudo-second-order model and the adsorption isotherms data were well described by Langmuir model with the maximum adsorption capacity of 625.022 mg/g for ITAC and 769.231 mg/g for ITAC-Fe. The present work suggested that ITAC-Fe could be used to remove tetracycline effectively from aqueous solutions.

  14. Biosorption Studies for the Removal of Malachite Green from its Aqueous Solution by Activated Carbon Prepared from Cassava Peel

    Directory of Open Access Journals (Sweden)

    C. Parvathi

    2011-01-01

    Full Text Available The association of dyes with health related problems is not a new phenomenon. The effectiveness of carbon adsorption for dye removal from textile effluent has made it an ideal alternative to other expensive treatment methods. The preparation of activated carbon from agricultural waste could increase economic return and reduce pollution. Cassava peel has been used as a raw material to produce activated carbon. The study investigates the removal of malachite green dye from its aqueous solution. The effects of condition such as adsorbent dosage, initial dye concentration, pH and contact time were studied. The adsorption capacity was demonstrated as a function of time for malachite green from aqueous solution by the prepared activated carbon. The results showed that as the amount of the adsorbent was increased, the percentage of dye removal increased accordingly. Higher adsorption percentages were observed at lower concentrations of malachite green dye. Silver nitrate treated cassava peel showed a better performance compared to Sulphuric acid treated and raw carbons, thus making it an interesting option for dye removal textile effluent.

  15. Preparation of Li4Ti5O12 electrode thin films by a mist CVD process with aqueous precursor solution

    Directory of Open Access Journals (Sweden)

    Kiyoharu Tadanaga

    2015-03-01

    Full Text Available Spinel Li4Ti5O12 thin films were prepared by a mist CVD process, using an aqueous solution of lithium nitrate and a water-soluble titanium lactate complex as the source of Li and Ti, respectively. In this process, mist particles ultrasonically atomized from a source aqueous solution were transferred by nitrogen gas to a heating substrate to prepare thin films. Scanning electron microscopy observation showed that thin films obtained by this process were dense and smooth, and thin films with a thickness of about 500 nm were obtained. In the X-ray diffraction analysis, formation of Li4Ti5O12 spinel phase was confirmed in the obtained thin film sintered at 700 °C for 4 h. The cell with the thin films as an electrode exhibited a capacity of about 110 mAh g−1, and the cell showed good cycling performance during 10 cycles.

  16. Apparatus for preparing a solution of a hyperpolarized noble gas for NMR and MRI analysis

    Science.gov (United States)

    Pines, Alexander; Budinger, Thomas; Navon, Gil; Song, Yi-Qiao; Appelt, Stephan; Bifone, Angelo; Taylor, Rebecca; Goodson, Boyd; Seydoux, Roberto; Room, Toomas; Pietrass, Tanja

    2008-06-10

    The present invention relates generally to nuclear magnetic resonance (NMR) techniques for both spectroscopy and imaging. More particularly, the present invention relates to methods in which hyperpolarized noble gases (e.g., Xe and He) are used to enhance and improve NMR and MRI. Additionally, the hyperpolarized gas solutions of the invention are useful both in vitro and in vivo to study the dynamics or structure of a system. When used with biological systems, either in vivo or in vitro, it is within the scope of the invention to target the hyperpolarized gas and deliver it to specific regions within the system.

  17. Gold nanoparticles prepared by laser ablation in aqueous biocompatible solutions: assessment of safety and biological identity for nanomedicine applications

    Directory of Open Access Journals (Sweden)

    Correard F

    2014-11-01

    Full Text Available Florian Correard,1,2 Ksenia Maximova,3 Marie-Anne Estève,1,2 Claude Villard,1 Myriam Roy,4 Ahmed Al-Kattan,3 Marc Sentis,3 Marc Gingras,4 Andrei V Kabashin,3 Diane Braguer1,2 1Aix Marseille Université, INSERM, CR02 UMR_S911, Marseille, France; 2APHM, Hôpital Timone, Marseille, France; 3Aix Marseille Université, CNRS, LP3 UMR 7341, Marseille, France; 4Aix Marseille Université, CNRS, CINAM, UMR 7325 Marseille, France Abstract: Due to excellent biocompatibility, chemical stability, and promising optical properties, gold nanoparticles (Au-NPs are the focus of research and applications in nanomedicine. Au-NPs prepared by laser ablation in aqueous biocompatible solutions present an essentially novel object that is unique in avoiding any residual toxic contaminant. This paper is conceived as the next step in development of laser-ablated Au-NPs for future in vivo applications. The aim of the study was to assess the safety, uptake, and biological behavior of laser-synthesized Au-NPs prepared in water or polymer solutions in human cell lines. Our results showed that laser ablation allows the obtaining of stable and monodisperse Au-NPs in water, polyethylene glycol, and dextran solutions. The three types of Au-NPs were internalized in human cell lines, as shown by transmission electron microscopy. Biocompatibility and safety of Au-NPs were demonstrated by analyzing cell survival and cell morphology. Furthermore, incubation of the three Au-NPs in serum-containing culture medium modified their physicochemical characteristics, such as the size and the charge. The composition of the protein corona adsorbed on Au-NPs was investigated by mass spectrometry. Regarding composition of complement C3 proteins and apolipoproteins, Au-NPs prepared in dextran solution appeared as a promising drug carrier. Altogether, our results revealed the safety of laser-ablated Au-NPs in human cell lines and support their use for theranostic applications. Keywords: protein

  18. Stability-indicating HPLC method for the determination of the stability of oxytocin parenteral solutions prepared in polyolefin bags.

    Science.gov (United States)

    Kaushal, G; Sayre, B E; Prettyman, T

    2012-02-01

    Oxytocin is very commonly used in clinical settings and is a nonapeptide hormone that stimulates the contraction of uterine smooth muscles. In this study the stability of extemporaneously compounded oxytocin solutions was investigated in polyolefin bags. The sterile preparations of oxytocin were compounded to the strength of 0.02 U/mL in accordance with United States Pharmacopeia (USP) standards. In order to carry out the stability testing of these parenteral products, the solutions were stored under three different temperature conditions of -20°C (frozen), 2-6°C (refrigerated), and 22-25°C (room temperature). Three solutions from each temperature were withdrawn and were assessed for stability on days 0, 7, 15, 21, and 30 as per the USP guidelines. The assay of oxytocin was examined by an HPLC method at each time point. No precipitation, cloudiness or color change was observed during this study at all temperatures. The assay content by HPLC revealed that oxytocin retains greater than at least 90% of the initial concentrations for 21 days. There was no significant change in pH and absorbance values for 21 days under all the conditions of storage. Oxytocin parenteral solutions in the final concentration of 0.02 U/mL and diluted in normal saline are stable for at least 30 days under frozen and refrigerated conditions for 30 days. At the room temperature, the oxytocin solutions were stable for at least 21 days. The stability analysis results show that the shelf-life of 21 days observed in this study was far better than their recommended expiration dates.

  19. Chemical and structural evaluation of activated carbon prepared from jute sticks for Brilliant Green dye removal from aqueous solution.

    Science.gov (United States)

    Asadullah, Mohammad; Asaduzzaman, Mohammad; Kabir, Mohammad Shajahan; Mostofa, Mohammad Golam; Miyazawa, Tomohisa

    2010-02-15

    Activated carbons have been prepared from jute sticks by chemical activation using ZnCl(2) and physical activation using steam for the removal of Brilliant Green dye from aqueous solution. The activated carbons and charcoal prepared from jute sticks were characterized by evaluating the surface chemistry, structural features and surface morphology. The maximum BET surface area was obtained to be 2304 m(2)/g for chemical activated carbon (ACC) while it is 730 and 80 m(2)/g for steam activated carbon (ACS) and charcoal, respectively. The FT-IR spectra exhibited that the pyrolysis and steam activation of jute sticks resulted in the release of aliphatic and O-containing functional groups by thermal effect. However, the release of functional groups is the effect of chemical reaction in the ZnCl(2) activation process. A honeycomb-type carbon structure in ACC was formed as observed on SEM images. Although charcoal and ACC were prepared at 500 degrees C the ACC exhibited much lower Raman sensitivity due to the formation of condensed aromatic ring systems. Due to high surface area and high porous structure with abundance of functional groups, the ACC adsorbed dye molecules with much higher efficiency than those of ACS and charcoal.

  20. Significant improvement in photoluminescence of ZnSe(S) alloyed quantum dots prepared in high pH solution.

    Science.gov (United States)

    Zan, Feng; Ren, Jicun

    2010-01-01

    In this paper, we described a simple approach for aqueous synthesis of highly luminescent ZnSe(S) alloyed quantum dots (QDs) in the presence of 3-mercaptopropionic acid as stabilizers using zinc chloride and NaHSe as precursors. The synthesis conditions were systematically investigated. We observed that the pH value of the Zn precursor solution had significant influence on the optical properties and the structure of the as-prepared ZnSe(S) QDs. The optimal pH value and molar ratio of Zn(2+) to HSe(-) were 12.0 and 25 : 1 respectively. Under the optimal conditions, we prepared highly photoluminescent ZnSe(S) QDs at up to 31% quantum yield (compared with Rhodamine 6G). The characterization of HRTEM and XRD showed that the ZnSe(S) QDs had good monodispersity and nice crystal structure. The fluorescence life time spectra demonstrated that ZnSe(S) QDs had a long lifetime in contrast to fluorescent dyes. Compared with the currently used organometallic approach, our method was 'green', the reaction condition was mild and the as-prepared ZnSe(S) QDs were water-soluble. More importantly, our method was low cost, and was very suitable for large-scale synthesis of highly luminescent ZnSe(S) QDs for the future applications. Copyright © 2009 John Wiley & Sons, Ltd.

  1. Preparation of SmBiO3 buffer layer on YSZ substrate by an improved chemical solution deposition route

    Science.gov (United States)

    Zhu, Xiaolei; Pu, Minghua; Zhao, Yong

    2016-12-01

    A quick route for chemical solution deposition (CSD) has been developed to prepare SmBiO3 (SBO) layers on yttria stabilized zirconia (YSZ) substrates rapidly by using of solid state decomposition (SSD) technique. The proper conditions for volatilization of lactic acid, which as solvent in precursor coated layer, and SBO growth are 115°C for 30 min and 794°C for 60 min in flowing Ar gas. The coated layers are amorphous structure of mixture oxides and quasi-crystal structure of SBO before and after growth, respectively. The total time by this quick CSD route for organic solvent volatilization, salts decomposed and layer growth is not up to 2 h, which are much less than that needed for traditional CSD of over 10 h. SBO layer is directly epitaxial growth on YSZ substrate without any lattice rotation. SBO layer prepared by this quick route as well as that by traditional route are suitable for the growth of YBCO. The superconducting transition temperature and critical current density of the coated YBCO layer on SBO/YSZ obtained by this quick route are up to 90 K and 1.66 MA/cm2. These results may be the usable reference for continuous preparation of SBO buffer layer on IBAD-YSZ/Ni-based alloy tapes.

  2. Effect of plasticizer on surface of free films prepared from aqueous solutions of salts of cationic polymers with different plasticizers

    Science.gov (United States)

    Bajdik, János; Fehér, Máté; Pintye-Hódi, Klára

    2007-06-01

    Acquisition of a more detailed understanding of all technological processes is currently a relevant tendency in pharmaceutical technology and hence in industry. A knowledge of film formation from dispersion of polymers is very important during the coating of solid dosage forms. This process and the structure of the film can be influenced by different additives. In the present study, taste-masking films were prepared from aqueous citric acid solutions of a cationic polymer (Eudragit ® E PO) with various hydrophilic plasticizers (glycerol, propylene glycol and different poly(ethylene glycols)). The mechanical properties, film thickness, wetting properties and surface free energy of the free films were studied. The aim was to evaluate the properties of surface of free films to predict the arrangement of macromolecules in films formed from aqueous solutions of salts of cationic polymers. A high molecular weight of the plasticizer decreased the work of deformation. The surface free energy and the polarity were highest for the film without plasticizer; the hydrophilic additives decreased these parameters. The direction of the change in polarity (a hydrophilic component caused a decrease in the polarity) was unexpected. It can be explained by the change in orientation of the macromolecules, a hydrophobic surface being formed. Examination of the mechanical properties and film thickness can furnish additional results towards a knowledge of film formation by this not frequently applied type of polymer from aqueous solution.

  3. Preparation and characterization of irradiated carboxymethyl sago starch-acid hydrogel and its application as metal scavenger in aqueous solution.

    Science.gov (United States)

    Basri, Sri Norleha; Zainuddin, Norhazlin; Hashim, Kamaruddin; Yusof, Nor Azah

    2016-03-15

    Carboxymethyl sago starch-acid hydrogel was prepared via irradiation technique to remove divalent metal ions (Pb, Cu and Cd) from their aqueous solution. The hydrogel was characterized by using Fourier Transform Infrared (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The removal of these metal ions was analyzed by using inductively coupled plasma-optic emission spectra (ICP-OES) to study the amount of metal uptake by the hydrogel. Parameters of study include effect of pH, amount of sample, contact time, initial concentration of metal solution and reaction temperature. FTIR spectroscopy shows the CMSS hydrogel absorption peaks at 1741cm(-1), 1605cm(-1) and 1430cm(-1) which indicates the substitution of carboxymethyl group of modified sago starch. The degradation temperature of CMSS hydrogel is higher compared to CMSS due to the crosslinking by electron beam radiation and formed a porous hydrogel. From the data obtained, about 93.5%, 88.4% and 85.5% of Pb, Cu and Cd ions has been respectively removed from their solution under optimum condition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. NANO-STRUCTURED SILVER COATING ON COPPER PREPARED IN AN ETHANOL-BASED SOLUTION

    Institute of Scientific and Technical Information of China (English)

    Zheliang Wei; Dian Tang; Thomas O'Keefe

    2005-01-01

    Recently, silver as an electrochemical deposit on copper substrate has been attracting much attention in the microelectronics field. To deposit nano-scale silver particles on copper, immersion plating using cyanide-based baths is commonly used. In this study, non-toxic ethanol was used as the plating solution. Sputtered copper samples were terized by a field emission scanning electron microscope (FE-SEM), an energy dispersive X-ray spectroscope (EDS),and an atomic force microscope (AFM). It was found that the deposited particles are metallic silver. After 3 s immersion,fine particles whose diameters were around 6 nm had covered about 40% of the surface of the copper substrate. After10 s immersion, the copper surface was completely covered by silver particles, the diameters of which have increased to about 10-15 nm. After the whole surface was covered, a dense and smooth silver coating was obtained.

  5. Biomimetic fat cell (BFC) preparation and for lindane removal from aqueous solution.

    Science.gov (United States)

    Liyan, Song; Youcai, Zhao; Guojian, Wang; Bing, Li; Dongjie, Niu; Xiaoli, Chai

    2007-07-19

    Fat tissue of organism can accumulate hydrophobic chemicals efficiently and the accumulation level has a positive correlation with fat quantity. In this work, based on this characteristic, an innovative agent, that is, biomimetic fat cell (BFC) has been synthesized with interfacial polymerization. BFC has a hydrophobic nucleolus-triolein and hydrophilic membrane-polyamide, through which water, carrying hydrophobic organic contaminants (HOCs), can pass. This process is followed by the accumulation of HOCs. BFC has 97.39% lindane removal ability. This is close to 98.12% lindane removal by powder active carbon (PAC) in aqueous solution and 7 mg/L initial concentration of lindane. BFC can be regenerated easily by organic solvent dialysis in comparison with high temperature or pressure used for PAC regeneration. Lindane removal by BFC may occur through two mechanisms: bioaccumulation by BFC nucleolus-triolein; and adsorption by BFC membrane. Bioaccumulation is the prevailing mechanism.

  6. Effects of outside air temperature on the preparation of antineoplastic drug solutions in biological safety cabinets.

    Science.gov (United States)

    Umemura, Masayuki; Itoh, Akio; Ando, Yuichi; Yamada, Kiyofumi; Wakiya, Yoshifumi; Nabeshima, Toshitaka

    2015-08-01

    In Japan, biological safety cabinets are commonly used by medical staff to prepare antineoplastic agents. At the Division of Chemotherapy for Outpatients, Nagoya University Hospital, a class II B2 biological safety cabinet is used. The temperature inside this biological safety cabinet decreases in winter. In this study, we investigated the effect of low outside air temperature on the biological safety cabinet temperature, time required to admix antineoplastic agents, and accuracy of epirubicin weight measurement. Studies were conducted from 1 January to 31 March 2008 (winter). The outside air temperature near the biological safety cabinet intake nozzle was compared with the biological safety cabinet temperature. The correlation between the outside air temperature and the biological safety cabinet temperature, time for cyclophosphamide and gemcitabine solubilization, and accuracy of epirubicin weight measurement were investigated at low and high biological safety cabinet temperatures. The biological safety cabinet temperature correlated with the outside air temperature of 5-20℃ (p antineoplastic agents. We suggest that a decrease in biological safety cabinet temperature may increase the time required to admix antineoplastic agents, thereby increasing the time for which outpatients must wait for chemotherapy. © The Author(s) 2014.

  7. Optimization of charge carrier transport balance for performance improvement of PDPP3T-based polymer solar cells prepared using a hot solution.

    Science.gov (United States)

    Wang, Jian; Zhang, Fujun; Zhang, Miao; Wang, Wenbin; An, Qiaoshi; Li, Lingliang; Sun, Qianqian; Tang, Weihua; Zhang, Jian

    2015-04-21

    Polymer solar cells (PSCs), with poly(diketopyrrolopyrrole-terthiophene) (PDPP3T):[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the active layers, were fabricated using solutions of different temperatures. The best power conversion efficiency (PCE) of the PSCs prepared using a hot solution was about 6.22%, which is better than 5.54% for PSCs prepared using cool (room temperature) solutions and 5.85% for PSCs prepared using cool solutions with a 1,8-diiodooctane (DIO) solvent additive. The underlying reasons for the improved PCE of the PSCs prepared using a hot solution could be attributed to the more dispersive donor and acceptor distribution in the active layer, resulting in a better bi-continuous interpenetrating network for exciton dissociation and charge carrier transport. An enhanced and more balanced charge carrier transport in the active layer is obtained for the PSCs prepared using a hot solution, which can be determined from the J-V curves of the related hole-only and electron-only devices.

  8. Magnetocaloric effect in Ni-Zn ferrite nanoparticles prepared by using solution combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K. D.; Kambale, R. C.; Hur, N. [Inha University, Incheon (Korea, Republic of)

    2014-12-15

    Ni{sub x}Zn{sub 1-x}Fe{sub 2}O{sub 4} (x = 0.2 and 0.3) ferrite nanoparticles with sizes ranging from 65 to 70 nm were synthesized employing the solution combustion route. The magnetocaloric behavior was investigated within the 50 K ≤ T ≤ 400 K range of temperatures (T). The entropy change (ΔS) and the adiabatic temperature change (ΔT) were derived from magnetization (M) and specific heat (C{sub P} ) measurements. Both compositions exhibited broad peaks for the isothermal entropy change. The magnetic field (H)-dependent ΔT was analyzed within the mean-field approximation scheme, and the observed magnetocaloric properties of the nanoparticle samples were compared with those of a bulk sample. Our study suggests that the magnetocaloric properties of magnetic oxides strongly depend on the particle size; thus, particle size should be considered as a key tuning parameter in the optimization of magnetic refrigeration.

  9. PREPARATION OF POROUS NANOCOMPOSITE SCAFFOLDS WITH HONEYCOMB MONOLITH STRUCTURE BY ONE PHASE SOLUTION FREEZE DRYING METHOD

    Institute of Scientific and Technical Information of China (English)

    Yang Xu; Duo Zhang; Zong-liang Wang; Zhan-tuan Gao; Pei-biao Zhang; Xue-si Chen

    2011-01-01

    Biodegradable porous nanocomposite scaffolds of poly(lactide-co-glycolide) (PLGA) and L-lactic acid (LAc) oligomer surface-grafted hydroxyapatite nanoparticles (op-HA) with a honeycomb monolith structure were fabricated with the single-phase solution freeze-drying method. The effects of different freezing temperatures on the properties of the scaffolds, such as microstructures, compressive strength, cell penetration and cell proliferation were studied. The highly porous and well interconnected scaffolds with a tunable pore structure were obtained. The effect of different freezing temperature (4℃, -20℃, -80℃ and -196℃) was investigated in relation to the scaffold morphology, the porosity varied from 91.2% to 83.0% and the average pore diameter varied from (167.2 ± 62.6) pm to (11.9 ± 4.2) μm while the σ10 increased significantly. The cell proliferation were decreased and associated with the above-mentioned properties. Uniform distribution of op-HA particles and homogeneous roughness of pore wall surfaces were found in the 4℃ frozen scaffold. The 4℃ frozen scaffold exhibited better cell penetration and increased cell proliferation because of its larger pore size, higher porosity and interconnection. The microstmctures described here provide a new approach for the design and fabrication of op-HA/PLGA based scaffold materials with potentially broad applicability for replacement of bone defects.

  10. (001) Oriented piezoelectric films prepared by chemical solution deposition on Ni foils

    Energy Technology Data Exchange (ETDEWEB)

    Yeo, Hong Goo, E-mail: hxy162@psu.edu; Trolier-McKinstry, Susan [Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2014-07-07

    Flexible metal foil substrates are useful in some microelectromechanical systems applications including wearable piezoelectric sensors or energy harvesters based on Pb(Zr,Ti)O₃ (PZT) thin films. Full utilization of the potential of piezoelectrics on metal foils requires control of the film crystallographic texture. In this study, (001) oriented PZT thin films were grown by chemical solution deposition (CSD) on Ni foil and Si substrates. Ni foils were passivated using HfO₂ grown by atomic layer deposition in order to suppress substrate oxidation during subsequent thermal treatment. To obtain the desired orientation of PZT film, strongly (100) oriented LaNiO₃ films were integrated by CSD on the HfO₂ coated substrates. A high level of (001) LaNiO₃ and PZT film orientation were confirmed by X-ray diffraction patterns. Before poling, the low field dielectric permittivity and loss tangents of (001) oriented PZT films on Ni are near 780 and 0.04 at 1 kHz; the permittivity drops significantly on poling due to in-plane to out-of-plane domain switching. (001) oriented PZT film on Ni displayed a well-saturated hysteresis loop with a large remanent polarization ~36 μC/cm², while (100) oriented PZT on Si showed slanted P-E hysteresis loops with much lower remanent polarizations. The |e{sub 31,f}| piezoelectric coefficient was around 10.6 C/m² for hot-poled (001) oriented PZT film on Ni.

  11. SOLUTIONING

    Directory of Open Access Journals (Sweden)

    Maria de Hoyos Guajardo, Ph.D. Candidate, M.Sc., B.Eng.

    2004-11-01

    Full Text Available The theory that is presented below aims to conceptualise how a group of undergraduate students tackle non-routine mathematical problems during a problem-solving course. The aim of the course is to allow students to experience mathematics as a creative process and to reflect on their own experience. During the course, students are required to produce a written ‘rubric’ of their work, i.e., to document their thoughts as they occur as well as their emotionsduring the process. These ‘rubrics’ were used as the main source of data.Students’ problem-solving processes can be explained as a three-stage process that has been called ‘solutioning’. This process is presented in the six sections below. The first three refer to a common area of concern that can be called‘generating knowledge’. In this way, generating knowledge also includes issues related to ‘key ideas’ and ‘gaining understanding’. The third and the fourth sections refer to ‘generating’ and ‘validating a solution’, respectively. Finally, once solutions are generated and validated, students usually try to improve them further before presenting them as final results. Thus, the last section deals with‘improving a solution’. Although not all students go through all of the stages, it may be said that ‘solutioning’ considers students’ main concerns as they tackle non-routine mathematical problems.

  12. Particle size analysis of prepared solutions and fingerprint deposits of high explosive materials

    Energy Technology Data Exchange (ETDEWEB)

    Carmack, W.J.; Hembree, P.B.

    1998-03-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) managed and operated by Lockheed Martin Idaho Technologies Company (LMITCO) was tasked via the Federal Aviation Administration (FAA) and US Department of Energy (DOE) to conduct various studies involving the detection and measurement of explosive materials and their associated residues. This report details the results of an investigation to determine the particle size characteristics of the explosive materials used in the design, development, and testing of trace explosives detection systems. These materials, in the form of water suspensions of plastic explosives, are used to provide a quantitative means of monitoring the performance characteristics of the detection systems. The purpose of this investigation is to provide data that allows a comparison between the particles deposited using the suspension standards and the particles deposited from fingerprints. This information may support the development of quality control aids, measurement methods, or performance criteria specifications for the use of trace explosives detection systems. For this report, particle size analyses were completed on explosives standard suspensions/solutions for composition C-4, Semtex-H, and Detasheet and fingerprints for C-4, Detasheet, and pentolite. Because of the difficulty in collecting microscopic images of the particles in the suspensions from test protocol surfaces, this paper discusses the characteristics of the particles as they are found on metal, glass, and paper. The results of the particle characterization analyses indicate that the water suspensions contain particulate composed of binder materials and dissolved portions of the explosive compounds. Upon drying of the water suspensions, significant particle nucleation and growth is observed. The nucleated particulate is comparable to the particulate deposited by fingerprints.

  13. Electrical conduction of polyimide films prepared from polyamic acid (PAA and pre-imidized polyimide (PI solution

    Directory of Open Access Journals (Sweden)

    2007-07-01

    Full Text Available Electrical conduction characteristics in two different polyimide films prepared by the imidization of polyamic acid (PAA and pre-imidized polyimide (PI solution were investigated. It is found that the current density of the polyimide film from PAA was higher than that of the polyimide film from PI at the same electric field, even though the conduction mechanism in both polyimide films follows the ionic hopping model. The hopping distance was calculated to be 2.8 nm for PAA type and 3.2 nm for PI type polyimide film. It is also found that the decay rate of the residual electrostatic charges on the polyimide films becomes faster in the PAA type than in the PI type polyimide film.

  14. Preparation of polyacrylnitrile (PAN)/ Manganese oxide based activated carbon nanofibers (ACNFs) for adsorption of Cadmium (II) from aqueous solution

    Science.gov (United States)

    Abdullah, N.; Yusof, N.; Jaafar, J.; Ismail, AF; Che Othman, F. E.; Hasbullah, H.; Salleh, W. N. W.; Misdan, N.

    2016-06-01

    In this work, activated carbon nanofibers (ACNFs) from precursor polyacrylnitrile (PAN) and manganese oxide (MnO2) were prepared via electrospinning process. The electrospun PAN/MnO2-based ACNFs were characterised in term of its morphological structure and specific surface area using SEM and BET analysis respectively. The comparative adsorption study of cadmium (II) ions from aqueous solution between the neat ACNFs, composite ACNFs and commercial granular activated carbon was also conducted. SEM analysis illustrated that composite ACNFs have more compact fibers with presence of MnO2 beads with smaller fiber diameter of 437.2 nm as compared to the neat ACNFs which is 575.5 nm. BET analysis elucidated specific surface area of ACNFs/MnO2 to be 67 m2/g. Under adsorption study, it was found out that Cd (II) removal by ACNFs/MnO2 was the highest (97%) followed by neat ACNFs (96%) and GAC (74%).

  15. Adsorption studies of the removal of anions from aqueous solutions onto an adsorbent prepared from wheat straw

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Modified wheat straw (MWS) was prepared by the grafting of epichlorohydrin,triethylamine and ethylenediamine onto WS.The characteristics of MWS and its adsorption capacity for NO-3,PO34and Cr2O72were investigated.The results indicate that amine groups with positive charge have been introduced into the structure of MWS,and significantly increased its anion adsorption property.The functions of MWS dosage,the solution pH,the contact time and temperature have significant influence on the adsorption process,and the adsorption is well fitted with the Langmuir equation and pseudo second-order model.The maximum adsorption capacity of MWS for NO-3,PO34(P) and Cr2O27(Cr) is 53.5,62.4 and 386.2 mg g-1,respectively.

  16. Preparation of carbon microspheres decorated with silver nanoparticles and their ability to remove dyes from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qingchun [Department of Chemistry, Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092 (China); Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433 (China); Wu, Qingsheng, E-mail: qswu@tongji.edu.cn [Department of Chemistry, Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092 (China); Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433 (China)

    2015-02-11

    Highlights: • Carbon microspheres decorated with silver nanoparticles (AgNP-CMSs) were prepared. • AgNP-CMSs show not only rapid and high adsorption capacity to methylene blue (MB) in water, but also excellent reusability. • It exhibits photocatalytic activity to Rhodamine B as well as MB under visible light. • The adsorption is from the ionic interactions but not the π–π conjugations. • The origin of photocatalysis is a surface plasmon resonance effect of AgNP on CMSs. - Abstract: Solid, but not hollow or porous, carbon microspheres decorated with silver nanoparticles (AgNP-CMSs) were prepared from silver nitrate and CMSs by a redox reaction at room temperature. The CMSs and AgNP-CMSs were characterized using X-ray diffraction, scanning electron microscopy, field emission scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and UV–vis spectrophotometry. Though with non-high specific surface area, the AgNP-CMSs exhibited a high adsorption capacity toward methylene blue (MB) in an aqueous solution. The AgNP-CMSs were able to remove all the MB from a solution of 30 mg/L MB in water within 1 min when the adsorbent concentration was 0.12 g/L. The AgNP-CMSs also exhibited good adsorption and photocatalytic activity in the decomposition of aqueous Rhodamine B as well as MB under visible light. FTIR was used to examine the interaction between AgNP-CMSs and MB, and the spectrum and more extra experiments suggest ionic interactions between cationic dyes and the negatively charged groups can be formed but not the presence of abundant π–π conjugations between dye molecules and the aromatic rings. The origin of the photocatalytic activity of AgNP-CMSs was attributed to a surface plasmon resonance (SPR) effect of the silver nanoparticles on the CMSs.

  17. Structural and magnetic properties of cobalt-doped iron oxide nanoparticles prepared by solution combustion method for biomedical applications.

    Science.gov (United States)

    Venkatesan, Kaliyamoorthy; Rajan Babu, Dhanakotti; Kavya Bai, Mane Prabhu; Supriya, Ravi; Vidya, Radhakrishnan; Madeswaran, Saminathan; Anandan, Pandurangan; Arivanandhan, Mukannan; Hayakawa, Yasuhiro

    2015-01-01

    Cobalt-doped iron oxide nanoparticles were prepared by solution combustion technique. The structural and magnetic properties of the prepared samples were also investigated. The average crystallite size of cobalt ferrite (CoFe2O4) magnetic nanoparticle was calculated using Scherrer equation, and it was found to be 16±5 nm. The particle size was measured by transmission electron microscope. This value was found to match with the crystallite size calculated by Scherrer equation corresponding to the prominent intensity peak (311) of X-ray diffraction. The high-resolution transmission electron microscope image shows clear lattice fringes and high crystallinity of cobalt ferrite magnetic nanoparticles. The synthesized magnetic nanoparticles exhibited the saturation magnetization value of 47 emu/g and coercivity of 947 Oe. The anti-microbial activity of cobalt ferrite nanoparticles showed better results as an anti-bacterial agent. The affinity constant was determined for the nanoparticles, and the cytotoxicity studies were conducted for the cobalt ferrite nanoparticles at different concentrations and the results are discussed.

  18. Polyethylene Glycol Electrolyte Lavage Solution versus Colonic Hydrotherapy for Bowel Preparation before Colonoscopy: A Single Center, Randomized, and Controlled Study

    Directory of Open Access Journals (Sweden)

    Yan Cao

    2014-01-01

    Full Text Available This single center, randomized, and controlled study aimed to compare the effectiveness and safety of polyethylene glycol electrolyte lavage (PEG-EL solution and colonic hydrotherapy (CHT for bowel preparation before colonoscopy. A total of 196 eligible outpatients scheduled for diagnostic colonoscopy were randomly assigned to the PEG-EL (n=102 or CHT (n=94 groups. Primary outcome measures included colonic cleanliness and adverse effects. Secondary outcome measures were patient satisfaction and preference, colonoscopic findings, ileocecal arrival rate, examiner satisfaction, and cecal intubation time. The results show that PEG-EL group was associated with significantly better colonic cleanliness than CHT group, fewer adverse effects, and increased examiner satisfaction. However, the CHT group had higher patient satisfaction and higher diverticulosis detection rates. Moreover, the results showed the same ileocecal arrival rate and patient preference between the two groups (P>0.05. These findings indicate that PEG-EL is the preferred option in patients who followed the preparation instructions completely.

  19. Structural and magnetic properties of cobalt-doped iron oxide nanoparticles prepared by solution combustion method for biomedical applications

    Science.gov (United States)

    Venkatesan, Kaliyamoorthy; Rajan Babu, Dhanakotti; Kavya Bai, Mane Prabhu; Supriya, Ravi; Vidya, Radhakrishnan; Madeswaran, Saminathan; Anandan, Pandurangan; Arivanandhan, Mukannan; Hayakawa, Yasuhiro

    2015-01-01

    Cobalt-doped iron oxide nanoparticles were prepared by solution combustion technique. The structural and magnetic properties of the prepared samples were also investigated. The average crystallite size of cobalt ferrite (CoFe2O4) magnetic nanoparticle was calculated using Scherrer equation, and it was found to be 16±5 nm. The particle size was measured by transmission electron microscope. This value was found to match with the crystallite size calculated by Scherrer equation corresponding to the prominent intensity peak (311) of X-ray diffraction. The high-resolution transmission electron microscope image shows clear lattice fringes and high crystallinity of cobalt ferrite magnetic nanoparticles. The synthesized magnetic nanoparticles exhibited the saturation magnetization value of 47 emu/g and coercivity of 947 Oe. The anti-microbial activity of cobalt ferrite nanoparticles showed better results as an anti-bacterial agent. The affinity constant was determined for the nanoparticles, and the cytotoxicity studies were conducted for the cobalt ferrite nanoparticles at different concentrations and the results are discussed. PMID:26491320

  20. Preparation of Different Silane-modified Silicalite-1 Membranes and Their Pervaporation Properties for Aqueous Ethanol Solution

    Institute of Scientific and Technical Information of China (English)

    LIU Na; MA Ying; MA Yalu

    2016-01-01

    A multi-layer mesoporous silicalite-1 membrane supported on commercially available porous alumina tubes was prepared by firstly dip-coating the tubes in silica colloid sol and then using a hydrothermal synthetic process. The mesoporous silicalite-1 membrane was further modified by grafting organosilane compounds with various alkyl chains length (CnH2n+1(CH3)2SiCl;n = 1, 3, 8, 12 and 18). These hydrophobic silicalite-1 membranes containing silane coupling agents effectively removed ethanol from 3 wt.%, 5 wt.% and 10 wt.% aqueous ethanol solutions by pervaporation over a temperature range of 303-323 K. The separation factor (α) of ethanol decreased as the ethanol content in the feed solu-tion increased from 3% to 10% whereas the permeation flux (J) basically remained constant. Ethanol separation factors (α) of 7.90-22.24 with total fluxes (J) of 0.76-2.89 kg/(m2·h) were obtained by pervaporation at 303-323 K for ethanol feed composition of 3%-10%.

  1. Surface and Texture Properties of Tb-Doped Ceria-Zirconia Solid Solution Prepared by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The three-way catalysts (TWCs) promoters Ce0.6Zr0.4-xTbxO2-y were prepared by sol-gel method. BET surface areas analysis indicated that an increase of the dopant Tb content from x=0.05 to x=0.15 favors an increase of surface area from 66.8 to 80.4 m2·g-1 compared with the undoped sample Ce0.60Zr0.40O2 65.1 m2·g-1 after calcination at 650 ℃. Transmission electron microscopy (TEM) observation indicated that the doped samples have a higher thermal stability. The XRD and Raman spectra confirmed that the Ce0.6Zr0.4-xTbxO2-y cubic solid solution is formed. XPS analysis revealed that Ce and Tb mainly existed in the form of Ce4+ and Tb3+, and Zr existed in the form of Zr4+ on the surface of the samples. The doped samples were homogenous in composition;the introduction of Tb into the CeO2-ZrO2 promoters resulted in the formation of a solid solution, and the concentration of surface lattice oxygen was increased.

  2. Preparation of carbon microspheres decorated with silver nanoparticles and their ability to remove dyes from aqueous solution.

    Science.gov (United States)

    Chen, Qingchun; Wu, Qingsheng

    2015-01-01

    Solid, but not hollow or porous, carbon microspheres decorated with silver nanoparticles (AgNP-CMSs) were prepared from silver nitrate and CMSs by a redox reaction at room temperature. The CMSs and AgNP-CMSs were characterized using X-ray diffraction, scanning electron microscopy, field emission scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and UV-vis spectrophotometry. Though with non-high specific surface area, the AgNP-CMSs exhibited a high adsorption capacity toward methylene blue (MB) in an aqueous solution. The AgNP-CMSs were able to remove all the MB from a solution of 30 mg/L MB in water within 1 min when the adsorbent concentration was 0.12 g/L. The AgNP-CMSs also exhibited good adsorption and photocatalytic activity in the decomposition of aqueous Rhodamine B as well as MB under visible light. FTIR was used to examine the interaction between AgNP-CMSs and MB, and the spectrum and more extra experiments suggest ionic interactions between cationic dyes and the negatively charged groups can be formed but not the presence of abundant π-π conjugations between dye molecules and the aromatic rings. The origin of the photocatalytic activity of AgNP-CMSs was attributed to a surface plasmon resonance (SPR) effect of the silver nanoparticles on the CMSs.

  3. Improvement of the preparation of sintered pellets of thorium phosphate-diphosphate and associated solid solutions from crystallized precursors

    Energy Technology Data Exchange (ETDEWEB)

    Clavier, N. [Groupe de Radiochimie, Institut de Physique Nucleaire, Bat. 100, Universite Paris-Sud-11, 91406 Orsay (France); Dacheux, N. [Groupe de Radiochimie, Institut de Physique Nucleaire, Bat. 100, Universite Paris-Sud-11, 91406 Orsay (France)]. E-mail: dacheux@ipno.in2p3.fr; Wallez, G. [Laboratoire de Cristallochimie du Solide, 4 place Jussieu, Universite Pierre et Marie Curie, 75252 Paris (France); Quarton, M. [Laboratoire de Cristallochimie du Solide, 4 place Jussieu, Universite Pierre et Marie Curie, 75252 Paris (France)

    2006-06-30

    Several compositions of thorium-uranium (IV) phosphate-hydrogenphosphate hydrate (U {sub x/2}Th{sub 2-x/2}(PO{sub 4}){sub 2}(HPO{sub 4}) . H{sub 2}O, TUPHPH) were prepared starting from actinides chloride solutions and concentrated phosphoric acid. The experimental synthesis parameters were optimized in order to get the quantitative precipitation of the cations and a good crystallization state. The extensive characterization of the solids demonstrated the existence of a complete solid solution between Th and U end-members and evidenced the good homogeneity of the powders. Their behaviors during heating treatment were then checked and confirm the formation of anhydrous thorium-uranium (IV) phosphate-hydrogenphosphate (TUPHP) and {alpha}-U {sub x}Th{sub 4-x}(PO{sub 4}){sub 4}(P{sub 2}O{sub 7}) ({alpha}-TUPD) acting as intermediates. Finally, the low-temperature crystallized precursors were used in original sintering processes in order to improve the efficiency of the former cold-pressing sintering procedure.

  4. Preparation of graphene oxide/chitosan/FeOOH nanocomposite for the removal of Pb(II) from aqueous solution.

    Science.gov (United States)

    Sheshmani, Shabnam; Akhundi Nematzadeh, Mehrnaz; Shokrollahzadeh, Soheila; Ashori, Alireza

    2015-09-01

    In the present study, a graphene oxide/chitosan/FeOOH (GO/Ch/FeOOH) nanostructured composite was prepared and used as an adsorbent for the removal of Pb(II) ions from aqueous solution. The nanocomposite was characterized by FT-IR, XRD, and SEM techniques. Several important parameters influencing the adsorption of Pb(II) ions such as pH (3-7), temperature (25-80 °C), shaking speed (150-800 rpm), contact time (10-70 min), and sorbent mass (10-100 mg) were studied. The results showed that, benefiting from the surface property of graphene oxide, the abundant amino and hydroxyl functional groups of chitosan, the adsorbent provides adequate and versatile adsorption for the Pb(II) ions under investigation. The batch adsorption experiments showed that the adsorption of the Pb(II) is considerably dependent on pH of milieu, amount of adsorbent, and contact time. The Freundlich and Langmuir adsorption models were used for the mathematical description of adsorption equilibrium and isotherm constants. Both models were applicable for the description of Pb(II) adsorption isotherm in the concentration range studied. However, Langmuir model showed higher correlation coefficient (R(2)) than Freundlich model. The study suggests that the GO/Ch/FeOOH is a promising nano adsorbent for the removal of Pb(II) ions from aqueous solution.

  5. Adsorption of U(VI) ions from aqueous solutions by activated carbon prepared from Antep pistachio (Pistacia vera L.) shells

    Energy Technology Data Exchange (ETDEWEB)

    Donat, Ramazan [Pamukkale Univ., Denizli (Turkey). Dept. of Chemistry; Erden, Kadriye Esen [Pamukkale Univ., Kinikli-Denizli (Turkey). Denizli Vocational School of Technical Sciences

    2017-08-01

    Antep pistachio (Pistacia vera L.) shells an abundant and low cost natural resource in Turkey was used to prepare activated carbon by physiochemical activation and carbon dioxide (CO{sub 2}) atmosphere as the activating agents at 700 C for 2 h. The adsorption equilibrium of U(VI) from aqueous solutions on such carbon has been studied using a batch system. The parameters that affect the U(VI) adsorption, such as particle size of adsorbent, contact time, of pH of the solution, and temperature, have been investigated and conditions have also been optimized. The equilibrium data for U(VI) ions' adsorption onto activated carbon well fitted to the Langmuir equation, with a maximum monolayer adsorption capacity of 8.68 mg/g, The Freundlich and Dubinin-Radushkevich (D-R) isotherms have been applied and the data correlated well with Freundlich model and that the adsorption is physical in nature (E{sub a}=15.46 kJ/mol). Thermodynamic parameters [ΔH{sub s}=11.33 kJ/mol, ΔS=0.084 kJ/molK, ΔG (293.15 K)=-13.29 kJ/mol] showed the endothermic heat of adsorption and the feasibility of the process.

  6. Microwave assisted preparation of magnesium phosphate cement (MPC) for orthopedic applications: A novel solution to the exothermicity problem

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Huan, E-mail: Huan.Zhou@rockets.utoledo.edu [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH 43606 (United States); Agarwal, Anand K.; Goel, Vijay K. [Department of Bioengineering, The University of Toledo, Toledo, OH 43606 (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH 43606 (United States); Division of Dentistry, The University of Toledo, Toledo, OH 43606 (United States)

    2013-10-15

    There are two interesting features of this paper. First, we report herein a novel microwave assisted technique to prepare phosphate based orthopedic cements, which do not generate any exothermicity during setting. The exothermic reactions during the setting of phosphate cements can cause tissue damage during the administration of injectable compositions and hence a solution to the problem is sought via microwave processing. This solution through microwave exposure is based on a phenomenon that microwave irradiation can remove all water molecules from the alkaline earth phosphate cement paste to temporarily stop the setting reaction while preserving the active precursor phase in the formulation. The setting reaction can be initiated a second time by adding aqueous medium, but without any exothermicity. Second, a special emphasis is placed on using this technique to synthesize magnesium phosphate cements for orthopedic applications with their enhanced mechanical properties and possible uses as drug and protein delivery vehicles. The as-synthesized cements were evaluated for the occurrences of exothermic reactions, setting times, presence of Mg-phosphate phases, compressive strength levels, microstructural features before and after soaking in (simulated body fluid) SBF, and in vitro cytocompatibility responses. The major results show that exposure to microwaves solves the exothermicity problem, while simultaneously improving the mechanical performance of hardened cements and reducing the setting times. As expected, the cements are also found to be cytocompatible. Finally, it is observed that this process can be applied to calcium phosphate cements system (CPCs) as well. Based on the results, this microwave exposure provides a novel technique for the processing of injectable phosphate bone cement compositions. - Highlights: • A microwave assisted system for bone cement manufacturing • A solution to exothermicity problem of acid–base reaction based bone cement

  7. Effect of Preparation Method on Surface Area and Crystalline Form of CeO2-ZrO2 Solid Solution

    Institute of Scientific and Technical Information of China (English)

    王晓红; 郭耘; 卢冠忠; 郭杨龙; 王筠松; 张志刚; 刘晓晖

    2004-01-01

    The CeO2-ZrO2 solid solutions were prepared by a reverse microemulsion method. The effect of preparation parameters on the surface area and crystalline form of the solid solutions were studied by the BET surface area and XRD analysis. The studies indicate that the separation of the microemulsion phase during the preparation procedure can decrease the specific surface area of sample, adding hydrogen peroxide in the matrix solution can increase the specific surface area and stability of sample. The surface area of sample calcined at 550 ℃ for 5 h is 149 m2·g-1, and that calcined at 900 ℃ for 6 h is 88 m2·g-1.The sample with tetragonal symmetry Ce0.5Zr0.5O2 phase has a higher stability.

  8. Preparation of Pseudo-boehmite and γ-Al2O3 Support by Neutralization of NaAlO2 Solution with CO2

    Institute of Scientific and Technical Information of China (English)

    Yang Qinghe; Liu Bin; Li Dadong; Shi Yahua; Nie Hong; Kang Xiaohong

    2003-01-01

    Pseudo-boehmite (PB) and γ-Al2O3 support are prepared by neutralization ofNaAlO2 solution with CO2(mixed gases) on bench scale. PB, typically loosely packed, fibrous particle/aggregate, is obtained by adjustingconcentration and flow rate of CO2 and concentration of NaAlO2 solution at a pH level lower than that commonlyassumed during neutralization. After calcination at different temperatures, γ-Al2O3 supports with different pore vol-ume and different pore size are prepared at different conditions.

  9. Utilization of waste phosphogypsum to prepare hydroxyapatite nanoparticles and its application towards removal of fluoride from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Deyi, E-mail: xixizhang@lut.cn [College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050 (China); State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730050 (China); Luo, Heming; Zheng, Liwen; Wang, Kunjie; Li, Hongxia; Wang, Yi; Feng, Huixia [College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050 (China)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer A novel approach on recycle of waste phosphogypsum was exploited. Black-Right-Pointing-Pointer Phosphogypsum was utilized to prepare hydroxyapatite nanoparticles with high purity. Black-Right-Pointing-Pointer nHAp derived from PG exhibits excellent adsoprtion capacity for fluoride. Black-Right-Pointing-Pointer Fluoride adsorbs onto nHAp mainly by electrostatic interaction and hydrogen bond. - Abstract: In the present study, waste phosphogypsum (PG) was utilized firstly to prepare hydroxyapatite nanoparticles (nHAp) via microwave irradiation technology. The nHAp derived from PG exhibited a hexagonal structure with the particle size about 20 nm Multiplication-Sign 60 nm and high purity. Meanwhile, the adsorption behaviour of fluoride onto the nHAp derived from PG was investigated to evaluate the potential application of this material for the treatment of the wastewater polluted with fluoride. The results indicate that the nHAp derived from PG can be used as an efficient adsorbent for the removal of fluoride from aqueous solution. The maximum adsorption capacities calculated from Langmuir-Freundlich model were 19.742, 26.108, 36.914 and 40.818 mg F{sup -}/g nHAp for 298, 308, 318 and 328 K, respectively. The pseudo-second order kinetic model was found to provide the best correlation of the used experimental data compared to the pseudo-first order and the adsorption isotherm could be well defined by Langmuir-Freundlich equation. The adsorption mechanism investigation shows that electrostatic interaction and hydrogen bond are the main driving force for fluoride uptake onto nHAp derived from waste PG.

  10. Microwave assisted preparation of magnesium phosphate cement (MPC) for orthopedic applications: a novel solution to the exothermicity problem.

    Science.gov (United States)

    Zhou, Huan; Agarwal, Anand K; Goel, Vijay K; Bhaduri, Sarit B

    2013-10-01

    There are two interesting features of this paper. First, we report herein a novel microwave assisted technique to prepare phosphate based orthopedic cements, which do not generate any exothermicity during setting. The exothermic reactions during the setting of phosphate cements can cause tissue damage during the administration of injectable compositions and hence a solution to the problem is sought via microwave processing. This solution through microwave exposure is based on a phenomenon that microwave irradiation can remove all water molecules from the alkaline earth phosphate cement paste to temporarily stop the setting reaction while preserving the active precursor phase in the formulation. The setting reaction can be initiated a second time by adding aqueous medium, but without any exothermicity. Second, a special emphasis is placed on using this technique to synthesize magnesium phosphate cements for orthopedic applications with their enhanced mechanical properties and possible uses as drug and protein delivery vehicles. The as-synthesized cements were evaluated for the occurrences of exothermic reactions, setting times, presence of Mg-phosphate phases, compressive strength levels, microstructural features before and after soaking in (simulated body fluid) SBF, and in vitro cytocompatibility responses. The major results show that exposure to microwaves solves the exothermicity problem, while simultaneously improving the mechanical performance of hardened cements and reducing the setting times. As expected, the cements are also found to be cytocompatible. Finally, it is observed that this process can be applied to calcium phosphate cements system (CPCs) as well. Based on the results, this microwave exposure provides a novel technique for the processing of injectable phosphate bone cement compositions.

  11. Preparation and Characterization of Nanoscale Zero-Valent Iron-Loaded Porous Sepiolite for Decolorizing Methylene Blue in Aqueous Solutions

    Science.gov (United States)

    Wang, Qingmiao; Ren, Gaofeng; Jia, Feifei; Song, Shaoxian

    2017-02-01

    The preparation and characterization of nanoscale zero-valent iron-loaded porous sepiolite, as well as its application in the decolorization of methylene blue in aqueous solution, have been studied in this work through the measurements of field emission scanning electron microscope with energy dispersive spectrometry, x-ray photoelectron spectrometry, Fourier transform infrared spectroscopy and specific surface area. The results showed that nanoscale zero-valent iron particles were successfully loaded on the surface and interior pores of sepiolite through physical adsorption. It was revealed that the decoloration capacity of methylene blue on nanoscale zero-valent iron-loaded porous sepiolite in water was comparable to that of nanoscale zero-valent iron, and nine times higher than that of natural sepiolite. This indicates that porous sepiolite was a good supporter for the loading of nanoscale zero-valent iron and nanoscale zero-valent iron-loaded sepiolite was a good decolorant because of its high decoloration efficiency and easy separation.

  12. A Low Cost and Facile Preparation of Hydrophobic Silica Films and Powders by a Solution-based Process

    Institute of Scientific and Technical Information of China (English)

    TIAN Tian; Tao Haizheng; XIAO Jing; XU Xinyi; An Jiming

    2015-01-01

    Super-hydrophobic surfaces with water contact angle (WCA) higher than 150° generated a lot of interests both in academic and in industry because of their self-cleaning functionality. Emphasis was given to the effect of pH value on the hydrophobic behavior of the obtainedfi lms or powders. Atfi rst, SiO2sols were prepared by diluted ammonia. We found that following the increase of pH value of sol from 8 to 9, WCAs of the obtainedfi lms increased from 121.8° to 131.8°. Following the continued increase of the pH value of sol, precipitates began to appear and smoothfi lm could not be obtained. The WCAs of the obtained powders could reach 121.7°, and through modifying by TMCS could further increase to as high as 165° and the water sliding angle (WSA) was 2°. The results of SEM indicate that the hydrophobic properties of the powders without modifying by TMCS should be originated from the formation of nano/micron binary structure,i e, a micron-scale diameter and a nano-scale surface roughness. In this work we provide a better solution to fabricate super-hydrophobic silica coating surface with a simple method at low cost.

  13. Preparation of a Modified Nanoalumina Sorbent for the Removal of Alizarin Yellow R and Methylene Blue Dyes from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Wasan T. Al-Rubayee

    2016-01-01

    Full Text Available A modified form of γ-alumina nanoparticles prepared by immobilization of 2,4-dinitrophenyl hydrazine on γ-alumina nanoparticles coated with sodium dodecyl sulfate (DNPH-γ-alumina for the removal of the anionic dye (Alizarin yellow R and cationic dye (Methylene blue from aqueous solutions has been investigated. The FTIR, SEM, TEM, XRD, BET, and BJH analysis techniques indicate that the modification reaction has occurred. Batch adsorption study revealed that 0.05 g amount of the modified adsorbent was capable of removing 95.6% and 65.6% of Alizarin yellow (AY and Methylene blue (MB dyes, respectively, in 60 min. The experimental equilibrium data showed that Langmuir isotherm applies well for describing the adsorption behavior, and the maximum adsorption capacity was found to be 47.8 mg/g and 32.8 mg/g for AY and MB on DNPH-γ-alumina, respectively. Kinetic studies showed best applicability of the second-order kinetic model. The DNPH-γ-alumina adsorbent proved capability, effectiveness, and selectivity for the removal of Alizarin yellow R dye. Therefore, it is possible to increase the efficiency of an adsorbent for the removal of pollutants by applying a modification to the surface of the adsorbent, and DNPH as a modifier proved efficient for the removal of a wider range of pollutants including metal ions and dye compounds.

  14. Preparation and evaluation adsorption capacity of cellulose xanthate of sugarcane bagasse for removal heavy metal ion from aqueous solutions

    Science.gov (United States)

    Iryani, D. A.; Risthy, N. M.; Resagian, D. A.; Yuwono, S. D.; Hasanudin, U.

    2017-05-01

    The discharge of heavy metals from industrial effluents into aquatic system in surrounding area of Lampung bay become a serious problem today. The data shows that the concentrations of heavy metals in this area are above allowable limits for the discharge of toxic heavy metals in the aquatic systems. The most common of heavy metal pollutant is divalent metal ions. Cellulose xanthate is one of the selective adsorbent to solve this problem, since xanthate contains two negative sulfur atoms that is capable to catch divalent metal ions. Preparation of cellulose xanthate was conducted by reacting carbon disulfide (CS2) and cellulose from sugarcane bagasse. The morphological characteristics of cellulose xanthate were visualized via Scanning Electron Microscope (SEM) and the presence of sulfur groups on sugarcane bagasse xanthate were identified by FTIR spectroscopic study. The degree of substitution (DS), degree of polymerization (DP), and adsorption capacities of cellulose xanthate for Cu2+ and Pb2+ metal were studied. The results of study reveals that the maximum adsorption capacities of Cu2+ and Pb2+ metal on cellulose xanthate are 54.226 mg Cu2+/g, and 51.776 mg Pb2+/g, respectively. This study reveals that cellulose xanthate could be a solution to reduce environmental pollution caused by industrial wastewater.

  15. Hysteretic Behavior upon Light Soaking in Perovskite Solar Cells Prepared via Modified Vapor-Assisted Solution Process.

    Science.gov (United States)

    Liu, Chong; Fan, Jiandong; Zhang, Xing; Shen, Yanjiao; Yang, Lin; Mai, Yaohua

    2015-05-06

    Recently, the organic-inorganic hybrid perovskite solar cells exhibit rapidly rising efficiencies, while anomalous hysteresis in perovskite solar cells remains unsolvable. Herein, a high-quality perovskite thin film is prepared by a modified vapor-assisted solution process, which is a simple but well-controllable method proven to be capable of producing a thin film with full surface coverage and grain size up to micrometers. The as-fabricated perovskite solar cell has efficiency as high as 10.2%. The hysteresis effects of both planar and mesoscopic TiO2-based perovskite solar cells have been comprehensively studied upon illumination. The results demonstrate that mesoporous-based perovskite cells combined with remarkable grain size are subject to alleviating the hysteresis effects in comparison to the planar cells. Likewise, mesoscopic TiO2-based perovskite cells perform independently of illumination and bias conditions prior to the measurements, whereas the planar cells display a reversible behavior of illumination and applied bias-dependent I-V curves. The present study would refer strip road for the stability study of the perovskite solar cells.

  16. Enhanced in vivo absorption of CB-1 antagonist in rats via solid solutions prepared by hot-melt extrusion.

    Science.gov (United States)

    Ranzani, L S; Font, J; Galimany, F; Santanach, A; Gomez-Gomar, A M; Casadevall, G; Gryczke, A

    2011-06-01

    The aim of the present work was to investigate in vitro dissolution properties of three binary solid solutions prepared by a hot-melt extrusion (HME) process with vinyl pirrolidone--vinyl acetate copolymer (Kollidon VA 64), ethyl acrylate, methyl methacrylate polymer (Eudragit E) polyetilenglicol 8000 (PEG 8000) with a cannabinoid type 1 (CB-1) antagonist. Hansen solubility parameters were calculated from the chemical structures of the drug and the individual polymers in order to predict miscibility. Solid state characterizations of drug substance, physical blends and HME formulations were performed with differential scanning calorimetry. The dissolution testing conducted under sink conditions revealed that the dissolution rate of HME formulations improved around 1.8-fold vs drug substance. Supersaturation dissolution study demonstrated that HME formulations composed by Eudragit E and Kollidon VA64 increased drug solubility between 30- and 35-fold, respectively comparing to the drug substance. Physical and chemical stability of formulations were studied at 40°C/75%HR with open dish during 15 days. The formulation composed by the drug and Eudragit E at 10:90 was evaluated for in vivo drug absorption in male Wistar-Hannover rats and it was found to increase CB-1 absorption threefold greater than pure drug oral suspension.

  17. Preparation of novel magnetic chitosan nanoparticle and its application for removal of humic acid from aqueous solution

    Science.gov (United States)

    Dong, Changlong; Chen, Wei; Liu, Cheng

    2014-02-01

    A novel magnetic chitosan nanoparticle (MCNP) with a BET surface area of 108.32 m2/g was prepared using a time and energy saving method at mild condition. MCNP exhibits an excellent ability to adsorb humic acid (HA) from aqueous solution in a wide range of initial HA concentration. The rate of HA adsorption is rapid with more than 50% of HA can be adsorbed in initial 10 min, and the equilibrium state can be reached in 60 min. The adsorption kinetics data fits well to the pseudo-second-order model, and the adsorption process is transport-limited at low initial HA concentration and attachment-limited at high initial HA concentration. The Langmuir isotherm model fits the equilibrium data better than the Freundlich isotherm model, indicating that the adsorption of HA onto MCNP is a monolayer adsorption. Based on the Langmuir isotherm model, the maximum adsorption capacity of HA is 32.6 mg/g at 25 °C. Thermodynamic parameters presents that the adsorption of HA onto MCNP is spontaneous and endothermic in nature. The mechanism for the adsorption of HA onto MCNP involves electrostatic interaction and hydrogen bonding. Regeneration studies indicate that MCNP can be recyclable for a long term. All the experimental results suggest that MCNP is a promising adsorbent for treating water that is contaminated with humic acid.

  18. Preparation of novel magnetic chitosan nanoparticle and its application for removal of humic acid from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Changlong, E-mail: jutimake@126.com [College of Environment, Hohai University, Nanjing 210098 (China); Chen, Wei; Liu, Cheng [Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098 (China); College of Environment, Hohai University, Nanjing 210098 (China)

    2014-02-15

    A novel magnetic chitosan nanoparticle (MCNP) with a BET surface area of 108.32 m{sup 2}/g was prepared using a time and energy saving method at mild condition. MCNP exhibits an excellent ability to adsorb humic acid (HA) from aqueous solution in a wide range of initial HA concentration. The rate of HA adsorption is rapid with more than 50% of HA can be adsorbed in initial 10 min, and the equilibrium state can be reached in 60 min. The adsorption kinetics data fits well to the pseudo-second-order model, and the adsorption process is transport-limited at low initial HA concentration and attachment-limited at high initial HA concentration. The Langmuir isotherm model fits the equilibrium data better than the Freundlich isotherm model, indicating that the adsorption of HA onto MCNP is a monolayer adsorption. Based on the Langmuir isotherm model, the maximum adsorption capacity of HA is 32.6 mg/g at 25 °C. Thermodynamic parameters presents that the adsorption of HA onto MCNP is spontaneous and endothermic in nature. The mechanism for the adsorption of HA onto MCNP involves electrostatic interaction and hydrogen bonding. Regeneration studies indicate that MCNP can be recyclable for a long term. All the experimental results suggest that MCNP is a promising adsorbent for treating water that is contaminated with humic acid.

  19. Preparation and tribological properties of inclusion complex of β-cyclodextrin/dialkyl pentasulfide as additive in PEG-600 aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Jiju; Xu, Xuefeng, E-mail: xuxuefeng@zjut.edu.cn; Li, Gan; Peng, Wei

    2014-01-15

    The inclusion complex of β-cyclodextrin (β-CD) and dialkyl pentasulfide (DPS), in which DPS was incorporated into β-CD cavities, was prepared by a co-precipitation method. The tribological properties of the complex used as lubricant additive in PEG 600 aqueous solution were investigated by a four-ball tester. The complex exhibited better tribological properties than β-CD under different loads, and also showed better anti-friction performance than DPS in the latter half of the test duration. The tribological action mechanism of the complex on a steel surface was studied according to the X-ray photoelectron spectroscopy (XPS) analyses. The β-CD molecules of the complexes were decomposed into various molecular fragments and the DPS molecules were released under the friction condition. It revealed that thiolate and ferrous sulfide (FeS) films formed by DPS played a major role, and iron alkoxide and carbon deposition films formed by the friction fragments of β-CD mainly exhibited anti-friction property on FeS-to-FeS interface. The interactions among different films led to the formation of a mixed boundary lubrication film.

  20. Preparation and Utilization of Kapok Hull Carbon for the Removal of Rhodamine-B from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    P. S. Syed Shabudeen

    2006-01-01

    Full Text Available A carbonaceous sorbent prepared from the indegeneous agricultural waste (which is facing solid waste disposal problem Kapok Hull, by acid treatment was tested for its efficiency in removing basic dyes. Batch kinetic and isotherm experiments were conducted to determine the sorption and desorption of the Rhodamine-B from aqueous solution with activated carbon. The factors affecting the rate processes involved in the removal of dye for initial dye concentration, agitation time, and carbon dose and particle size have been studied at ambient temperature. The adsorption process followed first order rate kinetics. The first-order rate equation by Lagergren was tested on the kinetic data, and isotherm data was analyzed for possible agreement with the Langmuir and Freundlich adsorption isotherm equations. The intraparticle diffusion rate equation from which adsorption rate constants, diffusion rate constants and diffusion coefficients were determined. Intraparticle diffusion was found to be the rate-limiting step. The structural and morphological of activated carbon were characterized by XRD and SEM studies respectively.

  1. Activated biochar derived from cactus fibres--preparation, characterization and application on Cu(II) removal from aqueous solutions.

    Science.gov (United States)

    Hadjittofi, Loukia; Prodromou, Melpomeni; Pashalidis, Ioannis

    2014-05-01

    The adsorption efficiency of activated biochar prepared from cactus fibres regarding the removal of Cu(II) from aqueous solutions has been investigated as a function of various physicochemical parameters (e.g. pH, initial metal concentration, ionic strength, temperature and contact time). Activation of the biochar took place using nitric acid oxidation and characterisation was performed by SEM analysis, FTIR spectroscopy, N2 adsorption and acid-base titrations. The results show that laminar structures constitute the material and carboxylic moieties are the predominant binding sites. The experimental data were analyzed by the Langmuir, Freundlich and Dubinin-Radushkevich adsorption models and the monolayer adsorption capacity was found to be 3.5 mol kg(-1). The effect of ionic strength and temperature on the adsorption efficiency indicates that at low pH outer-sphere and at near neutral pH inner-sphere complexes are the predominant surface species and the kinetic data obtained were fitted very well by the Lagergren rate expression.

  2. Compositionally and structurally modified SrTiO{sub 3} thin films prepared by chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Spitzner, Dirk; Gutmann, Emanuel; Reibold, Marianne; Meyer, Dirk C. [Institut fuer Strukturphysik, Technische Universitaet Dresden (Germany); Mahltig, Boris [GMBU e.V., Arbeitsgruppe Funktionelle Schichten, Dresden (Germany)

    2009-07-01

    For electronic and architectural design of functional electroceramic devices, materials with a perovskite-type of structure play a major role. For high-k dielectric, sensing and thermal switching applications the introduction of Barium into SrTiO{sub 3}(STO) allows tuning the electrical properties by tuning the paraelectric-to-ferroelectric transition temperature. For thin film preparation a classic sol-gel route was modified by refluxing as well as solvothermal treatment of the as-synthesized sols. For treated sols the decomposition, phase evolution and transition behaviour differed and from X-ray diffraction (XRD) we observed a supression of foreign phases and a higher degree of compositional homogeneity. In this context also the homologous series of perovskite-related Ruddlesden-Popper (RP) phases promise an engineering of electrical properties by selecting a specific member. Exemplarily we realised the chemical solution deposition of epitaxial thin films of SrO(SrTiO{sub 3}){sub n} RP phases (n=1,2,3) on STO substrates. Structural characteristics of the films were analysed by means of XRD and HRTEM. An application as buffer layers exhibiting tuneable dielectric properties is conceivable.

  3. Utilization of waste phosphogypsum to prepare hydroxyapatite nanoparticles and its application towards removal of fluoride from aqueous solution.

    Science.gov (United States)

    Zhang, Deyi; Luo, Heming; Zheng, Liwen; Wang, Kunjie; Li, Hongxia; Wang, Yi; Feng, Huixia

    2012-11-30

    In the present study, waste phosphogypsum (PG) was utilized firstly to prepare hydroxyapatite nanoparticles (nHAp) via microwave irradiation technology. The nHAp derived from PG exhibited a hexagonal structure with the particle size about 20 nm × 60 nm and high purity. Meanwhile, the adsorption behaviour of fluoride onto the nHAp derived from PG was investigated to evaluate the potential application of this material for the treatment of the wastewater polluted with fluoride. The results indicate that the nHAp derived from PG can be used as an efficient adsorbent for the removal of fluoride from aqueous solution. The maximum adsorption capacities calculated from Langmuir-Freundlich model were 19.742, 26.108, 36.914 and 40.818 mg F(-)/g nHAp for 298, 308, 318 and 328 K, respectively. The pseudo-second order kinetic model was found to provide the best correlation of the used experimental data compared to the pseudo-first order and the adsorption isotherm could be well defined by Langmuir-Freundlich equation. The adsorption mechanism investigation shows that electrostatic interaction and hydrogen bond are the main driving force for fluoride uptake onto nHAp derived from waste PG.

  4. Preparation and Characterization of Self-Reinforced Antibacterial and Oil-Resistant Paper Using a NaOH/Urea/ZnO Solution: e0140603

    National Research Council Canada - National Science Library

    Li Jiao; Jinxia Ma; Hongqi Dai

    2015-01-01

      This paper describes self-reinforced antibacterial and oil-resistant properties that were successfully prepared by surface selective dissolution of filter paper in a NaOH/Urea/ZnO (weight ratio of 8:12:0.25) aqueous solution...

  5. Preparation and Characterization of Self-Reinforced Antibacterial and Oil-Resistant Paper Using a NaOH/Urea/ZnO Solution

    National Research Council Canada - National Science Library

    Jiao, Li; Ma, Jinxia; Dai, Hongqi

    2015-01-01

    This paper describes self-reinforced antibacterial and oil-resistant properties that were successfully prepared by surface selective dissolution of filter paper in a NaOH/Urea/ZnO (weight ratio of 8:12:0.25) aqueous solution...

  6. Stability of ampicillin, piperacillin, cefotaxime, netilmicin and amikacin in an L-amino acid solution prepared for total parenteral nutrition of newborn infants

    DEFF Research Database (Denmark)

    Goldstein, K; Colding, H; Andersen, G E

    1988-01-01

    The stability of ampicillin, piperacillin and cefotaxime, alone or in combination with either netilmicin or amikacin, was tested by microbiological methods at 29 degrees C (ampicillin, also at 22 degrees C) in an L-amino acid solution specially prepared for newborn infants. In the case of ampicil...

  7. Preparation of benzyl-[alpha]-D[sub 1]-alcohol by the reduction of benzaldehyde with Raney alloys in an alkaline deuterium oxide solution

    Energy Technology Data Exchange (ETDEWEB)

    Tsukinoki, Takehito; Mataka, Shuntaro; Tashiro, Masashi (Kyushu Univ. (Japan). Inst. of Advanced Material Study); Ishimoto, Keiko (Kyushu Univ. (Japan). Graduate School of Engineering Sciences); Tsuzuki, Hirohisa (Kyushu Univ., Fukuoka (Japan). Center of Advanced Instrumental Analysis)

    1993-10-01

    Benzyl-[alpha]-d[sub 1]-alcohol was prepared in high isotopic purity by the reduction of benzaldehyde with Raney Cu-Al alloy in 10% Na[sub 2]CO[sub 3]-D[sub 2]O solution using ultrasonic irradiation. (Author).

  8. Preparation and characterization of trihydroxamic acid functionalized carbon materials for the removal of Cu(II) ions from aqueous solution

    Science.gov (United States)

    Godino-Salido, M. Luz; Santiago-Medina, Antonio; López-Garzón, Rafael; Gutiérrez-Valero, María D.; Arranz-Mascarós, Paloma; López de la Torre, M. Dolores; Domingo-García, María; López-Garzón, F. Javier

    2016-11-01

    The main objective of this study is to prepare and characterize two functionalizated carbon materials with enhanced adsorptive properties for Cu(II). Thus, two novel hybrid materials have been prepared by a non-covalent functionalization method based on the adsorption of a pyrimidine-desferrioxamine-B conjugate compound (H4L) on two activated carbons, ACs (labelled Merck and F). The adsorption of H4L on the ACs is pH-dependent and highly irreversible. This is due to strong π-π interactions between the arene centers of the ACs and the pyrimidine moiety of H4L. The textural characterization of the AC/H4L hybrids shows large decreases of their surface areas. Thus the values of Merck and F are 1031 and 1426 m2/g respectively, while these of Merck/H4L and F/H4L hybrids are 200 and 322 m2/g. An important decrease in the micropore volumes is also found, due to the blockage of narrow porosity produced by the adsorption of H4L molecules. The ACs/H4L hybrids show larger adsorption capacities for Cu(II) (0.105(4) and 0.13(2) mmol/g, at pH 2.0, and 0.20(3) and 0.242(9) mmol/g, at pH 5.5, for Merck/H4L and F/H4L, respectively) than those of the ACs (0.024(6) and 0.096(9) mmol/g, at pH 2.0, and 0.10(2) and 0.177(8) mmol/g, at pH 5.5, for Merck and F respectively), which is explained on the basis of the complexing ability of the trihydroxamic acid functions. The desorption of Cu(II) from the ACs/H4L/Cu(II) materials in acid solution allows the regeneration of most active sites (78.5% in the case of Merck/H4L/Cu(II) and 83.0% in the case of F/H4L/Cu(II)).

  9. Preparation and characterization of trihydroxamic acid functionalized carbon materials for the removal of Cu(II) ions from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Godino-Salido, M. Luz, E-mail: mlgodino@ujaen.es [Departamento de Química Inorgánica y Orgánica, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén (Spain); Santiago-Medina, Antonio; López-Garzón, Rafael; Gutiérrez-Valero, María D.; Arranz-Mascarós, Paloma; López de la Torre, M. Dolores [Departamento de Química Inorgánica y Orgánica, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén (Spain); Domingo-García, María; López-Garzón, F. Javier [Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071, Granada (Spain)

    2016-11-30

    Highlights: • Hybrid materials made by irreversible adsorption of a deferoxamine derivative on ACs. • The surface trihydroxamate groups are the active functions of the hybrid materials. • Great adsorption capacity for Cu(II) of novel trihydroxamic acid functionalized ACs. • Desorption of Cu(II) from the loaded hybrid materials regenerates the parent hybrids. - Abstract: The main objective of this study is to prepare and characterize two functionalizated carbon materials with enhanced adsorptive properties for Cu(II). Thus, two novel hybrid materials have been prepared by a non-covalent functionalization method based on the adsorption of a pyrimidine-desferrioxamine-B conjugate compound (H{sub 4}L) on two activated carbons, ACs (labelled Merck and F). The adsorption of H{sub 4}L on the ACs is pH-dependent and highly irreversible. This is due to strong π-π interactions between the arene centers of the ACs and the pyrimidine moiety of H{sub 4}L. The textural characterization of the AC/H{sub 4}L hybrids shows large decreases of their surface areas. Thus the values of Merck and F are 1031 and 1426 m{sup 2}/g respectively, while these of Merck/H{sub 4}L and F/H{sub 4}L hybrids are 200 and 322 m{sup 2}/g. An important decrease in the micropore volumes is also found, due to the blockage of narrow porosity produced by the adsorption of H{sub 4}L molecules. The ACs/H{sub 4}L hybrids show larger adsorption capacities for Cu(II) (0.105(4) and 0.13(2) mmol/g, at pH 2.0, and 0.20(3) and 0.242(9) mmol/g, at pH 5.5, for Merck/H{sub 4}L and F/H{sub 4}L, respectively) than those of the ACs (0.024(6) and 0.096(9) mmol/g, at pH 2.0, and 0.10(2) and 0.177(8) mmol/g, at pH 5.5, for Merck and F respectively), which is explained on the basis of the complexing ability of the trihydroxamic acid functions. The desorption of Cu(II) from the ACs/H{sub 4}L/Cu(II) materials in acid solution allows the regeneration of most active sites (78.5% in the case of Merck/H{sub 4}L/Cu(II) and 83

  10. Facile Preparation of Highly Conductive Metal Oxides by Self-Combustion for Solution-Processed Thermoelectric Generators.

    Science.gov (United States)

    Kang, Young Hun; Jang, Kwang-Suk; Lee, Changjin; Cho, Song Yun

    2016-03-01

    Highly conductive indium zinc oxide (IZO) thin films were successfully fabricated via a self-combustion reaction for application in solution-processed thermoelectric devices. Self-combustion efficiently facilitates the conversion of soluble precursors into metal oxides by lowering the required annealing temperature of oxide films, which leads to considerable enhancement of the electrical conductivity of IZO thin films. Such enhanced electrical conductivity induced by exothermic heat from a combustion reaction consequently yields high performance IZO thermoelectric films. In addition, the effect of the composition ratio of In to Zn precursors on the electrical and thermoelectric properties of the IZO thin films was investigated. IZO thin films with a composition ratio of In:Zn = 6:2 at the low annealing temperature of 350 °C showed an enhanced electrical conductivity, Seebeck coefficient, and power factor of 327 S cm(-1), 50.6 μV K(-1), and 83.8 μW m(-1) K(-2), respectively. Moreover, the IZO thin film prepared at an even lower temperature of 300 °C retained a large power factor of 78.7 μW m(-1) K(-2) with an electrical conductivity of 168 S cm(-1). Using the combustive IZO precursor, a thermoelectric generator consisting of 15 legs was fabricated by a printing process. The thermoelectric array generated a thermoelectric voltage of 4.95 mV at a low temperature difference (5 °C). We suggest that the highly conductive IZO thin films by self-combustion may be utilized for fabricating n-type flexible printed thermoelectric devices.

  11. Preparation and characterization of novel P(HEA/IA) hydrogels for Cd{sup 2+} ion removal from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Antić, Katarina M.; Babić, Marija M.; Vuković, Jovana J. Jovašević [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade (Serbia); Vasiljević-Radović, Dana G. [Institute for Chemistry, Technology and Metallurgy, University of Belgrade, Njegoseva 12, Belgrade (Serbia); Onjia, Antonije E. [Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, Belgrade (Serbia); Filipović, Jovanka M. [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade (Serbia); Tomić, Simonida Lj., E-mail: simonida@tmf.bg.ac.rs [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade (Serbia)

    2015-05-30

    Highlights: • Hydrogels based on 2-hydroxyethyl acrylate and itaconic acid (P(HEA/IA)) were synthesized. • Cd{sup 2+} ion removal was investigated. • The surface and cross-section of hydrogels were observed by SEM and AFM. • The adsorption kinetics and isotherms of cadmium ions on the hydrogel were studied. • Approximately 95% of the adsorbed cadmium could be recovered by 0.1 M HNO{sub 3} treatment. - Abstract: Series of novel hydrogels based on 2-hydroxyethyl acrylate (HEA) and itaconic acid (IA), P(HEA/IA) copolymers, were prepared by free radical cross-linking copolymerization and investigated as potential adsorbents for Cd{sup 2+} removal from aqueous solution. The hydrogels before and after Cd{sup 2+} adsorption were characterized using FTIR, DSC, SEM/EDX, AFM and DMA analysis. The swelling results showed that these hydrogels are pH and temperature sensitive. In order to evaluate adsorption behavior of samples various factors affecting the Cd{sup 2+} uptake behavior, such as: contact time, temperature, pH, ionic strength, adsorbent weight, competitive ions and initial concentration of the metal ions were investigated. Five adsorption isotherms and two kinetic models were studied. The adsorption behavior can be very well described by the pseudo-second order kinetic model and Langmuir isotherm. Multicomponent adsorption studies revealed that adsorption of cadmium depends on the type of metal ions present in the system. Desorption studies showed that hydrogel can be reused three times with only 15% loss of adsorption capacity. All results indicate that the sample with the highest IA content is the most promising adsorbent for Cd{sup 2+} removal.

  12. H2 Production Under Visible Light Irradiation from Aqueous Methanol Solution on CaTiO3:Cu Prepared by Spray Pyrolysis

    Science.gov (United States)

    Lim, Sung Nam; Song, Shin Ae; Jeong, Yong-Cheol; Kang, Hyun Woo; Park, Seung Bin; Kim, Ki Young

    2017-10-01

    Perovskite-type photocatalysts of CaCu x Ti1- x O3 (0 ≤ x ≤ 0.02) powder were prepared by spray pyrolysis of aqueous solution or aqueous solution with polymeric additive. The effects of the amount of copper ions doped in the photocatalyst and the precursor type on the photocatalytic activity under visible-light irradiation were investigated. The crystal structure, oxidation state, and light adsorption properties of the prepared photocatalysts were analyzed using x-ray diffraction, x-ray photoelectron spectroscopy, and diffuse reflectance spectroscopy, respectively. The doping of copper ions in CaTiO3 allowed visible-light absorption owing to a narrowing of the band gap energy of the host material through the formation of a new donor level for copper ions. Among the doped samples prepared from the aqueous precursor, CaTiO3 doped with 1 mol.% copper ions had the highest hydrogen evolution rate (140.7 μmol g-1 h-1). Notably, the hydrogen evolution rate of the photocatalyst doped with 1 mol.% copper ions prepared from the aqueous precursor with polymeric additive (295.0 μmol g-1 h-1) was two times greater than that prepared from the aqueous precursor, due to the morphology effect.

  13. Novel polyamide-based nanofibers prepared by electrospinning technique for headspace solid-phase microextraction of phenol and chlorophenols from environmental samples.

    Science.gov (United States)

    Bagheri, Habib; Aghakhani, Ali; Baghernejad, Masoud; Akbarinejad, Alireza

    2012-02-24

    A novel solid phase microextraction (SPME) fiber was fabricated by electrospinning method in which a polymeric solution was converted to nanofibers using high voltages. A thin stainless steel wire was coated by the network of polymeric nanofibers. The polymeric nanofiber coating on the wire was mechanically stable due to the fine and continuous nanofibers formation around the wire with a three dimensional structure. Polyamide (nylon 6), due to its suitable characteristics was used to prepare the unbreakable SPME nanofiber. The scanning electron microscopy (SEM) images of this new coating showed a diameter range of 100-200 nm for polyamide nanofibers with a homogeneous and porous surface structure. The extraction efficiency of new coating was investigated for headspace solid-phase microextraction (HS-SPME) of some environmentally important chlorophenols from aqueous samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Effect of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength and polyamide amount were investigated and optimized. In order to improve the chromatographic behavior of phenolic compounds, all the analytes were derivatized prior to the extraction process using basic acetic anhydride. The detection limits of the method under optimized conditions were in the range of 2-10 ng L(-1). The relative standard deviations (RSD) (n=3) at the concentration level of 1.7-6.7 ng mL(-1) were obtained between 1 and 7.4%. The calibration curves of chlorophenols showed linearity in the range of 27-1330 ng L(-1) for phenol and monochlorophenols and 7-1000 ng L(-1) for dichloro and trichlorophenols. Also, the proposed method was successfully applied to the extraction of phenol and chlorophenols from real water samples and relative recoveries were between 84 and 98% for all the selected analytes except for 2,4,6 tricholophenol which was between 72 and 74%. Copyright © 2011

  14. Novel polyamide-based nanofibers prepared by electrospinning technique for headspace solid-phase microextraction of phenol and chlorophenols from environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, Habib, E-mail: bagheri@sharif.edu [Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of); Aghakhani, Ali; Baghernejad, Masoud; Akbarinejad, Alireza [Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of)

    2012-02-24

    A novel solid phase microextraction (SPME) fiber was fabricated by electrospinning method in which a polymeric solution was converted to nanofibers using high voltages. A thin stainless steel wire was coated by the network of polymeric nanofibers. The polymeric nanofiber coating on the wire was mechanically stable due to the fine and continuous nanofibers formation around the wire with a three dimensional structure. Polyamide (nylon 6), due to its suitable characteristics was used to prepare the unbreakable SPME nanofiber. The scanning electron microscopy (SEM) images of this new coating showed a diameter range of 100-200 nm for polyamide nanofibers with a homogeneous and porous surface structure. The extraction efficiency of new coating was investigated for headspace solid-phase microextraction (HS-SPME) of some environmentally important chlorophenols from aqueous samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Effect of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength and polyamide amount were investigated and optimized. In order to improve the chromatographic behavior of phenolic compounds, all the analytes were derivatized prior to the extraction process using basic acetic anhydride. The detection limits of the method under optimized conditions were in the range of 2-10 ng L{sup -1}. The relative standard deviations (RSD) (n = 3) at the concentration level of 1.7-6.7 ng mL{sup -1} were obtained between 1 and 7.4%. The calibration curves of chlorophenols showed linearity in the range of 27-1330 ng L{sup -1} for phenol and monochlorophenols and 7-1000 ng L{sup -1} for dichloro and trichlorophenols. Also, the proposed method was successfully applied to the extraction of phenol and chlorophenols from real water samples and relative recoveries were between 84 and 98% for all the selected analytes except for 2,4,6 tricholophenol which was between 72 and 74%.

  15. Chelating fibers prepared with a wet spinning technique using a mixture of a viscose solution and a polymer ligand for the separation of metal ions in an aqueous solution.

    Science.gov (United States)

    Kagaya, Shigehiro; Miyazaki, Hiroyuki; Inoue, Yoshinori; Kato, Toshifumi; Yanai, Hideyuki; Kamichatani, Waka; Kajiwara, Takehiro; Saito, Mitsuru; Tohda, Koji

    2012-02-15

    Chelating fibers containing polymer ligands such as carboxymethylated polyallylamine, carboxymethylated polyethyleneimine, and a copolymer of diallylamine hydrochloride/maleic acid were prepared with a wet spinning technique using mixtures of a viscose solution and the polymer ligands. The chelating fibers obtained effectively adsorbed various metal ions, including Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), Ti(IV), and Zn(II). The metal ions adsorbed could be readily desorbed using 0.1 or 0.5 mol L(-1) HNO(3). The chelating fiber containing carboxymethylated polyallylamine was available for the separation of some metal ions in synthetic wastewater containing a large amount of Na(2)SO(4). The wet spinning technique using a solution containing a base polymer and a polymer ligand was quite simple and effective and would be applicable for preparing various chelating fibers.

  16. YBa{sub 2}Cu{sub 3}O{sub 7-x} thin films prepared by chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Apetrii, Claudia

    2009-11-25

    The discovery of superconductivity in ceramic materials by Bednorz and Mueller in early 1987, immediately followed by Wu et al., who showed that YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) becomes superconducting (92 K) well above the boiling point of nitrogen (77 K) created a great excitement in superconductivity research. Potential applications of high T{sub c}-superconductors require large critical currents and high-applied magnetic fields. Effective ways to increase the critical current density at high magnetic fields in YBCO are the introduction of nanoparticles and chemical substitution of yttrium by other rare earth elements. Since low costs and environmental compatibility are essential conditions for the preparation of long length YBCO films, the cost effective chemical solution deposition (CSD) procedure was selected, given that no vacuum technology is required. To reveal the flexibility and the good optimization possibilities of the CSD approach two main processes were chosen for comparison: a fluorine-free method, namely the polymer-metal precursor technique, and a fluorine-based method, the metalorganic deposition (MOD) using the trifluoroacetates (TFA) technique. Sharp transition temperature widths {delta}T{sub c} of 1.1 K for the polymer metal method, 0.8 K for TFA method and critical current densities J{sub c} of {approx}3.5 MA/cm{sup 2} shows that high quality YBCO thin films can be produced using both techniques. Especially interesting is the magnetic field dependence of the critical current density J{sub c}(B) of the Y(Dy)BCO (80 %) films showing that for the lower magnetic fields the critical current density J{sub c}(B) is higher for a standard YBCO film, but at fields higher than 4.5 T the critical current density J{sub c}(B) of Y(Dy)BCO is larger than that for the YBCO. Above 8 T, J{sub c}(B) of the Y(Dy)BCO film is more than one order of magnitude higher than in pure YBCO film. (orig.)

  17. Adsorption-desorption characteristics of phenol and reactive dyes from aqueous solution on mesoporous activated carbon prepared from waste tires.

    Science.gov (United States)

    Tanthapanichakoon, W; Ariyadejwanich, P; Japthong, P; Nakagawa, K; Mukai, S R; Tamon, H

    2005-04-01

    Liquid-phase adsorption-desorption characteristics and ethanol regeneration efficiency of an activated carbon prepared from waste tires and a commercial activated carbon were investigated. Water vapor adsorption experiments reveal that both activated carbons showed hydrophobic surface characteristics. Adsorption experiments reveal that the prepared activated carbon possessed comparable phenol adsorption capacity as the commercial one but clearly larger adsorption capacity of two reactive dyes, Black 5 and Red 31. It was ascertained that the prepared activated carbon exhibited less irreversible adsorption of phenol and the two dyes than its commercial counterpart. Moreover, ethanol regeneration efficiency of the prepared AC saturated with either dye was higher than that of the commercial AC. Because of its superior liquid-phase adsorption-desorption characteristics as well as higher ethanol regeneration efficiency, the prepared activated carbon is more suitable for wastewater treatment, especially for adsorbing similarly bulky adsorbates.

  18. Assessment of preparation methods for organic phosphorus analysis in phosphorus-polluted Fe/Al-rich Haihe river sediments using solution 31P-NMR.

    Directory of Open Access Journals (Sweden)

    Wenqiang Zhang

    Full Text Available Fe/Al-rich river sediments that were highly polluted with phosphorus (P were used in tests to determine the optimum preparation techniques for measuring organic P (Po using solution (31P nuclear magnetic resonance spectroscopy ((31P-NMR. The optimum pre-treatment, extraction time, sediment to solution ratio and sodium hydroxide-ethylenediaminetetraacetic acid (NaOH-EDTA extractant solution composition were determined. The total P and Po recovery rates were higher from freeze- and air-dried samples than from fresh samples. An extraction time of 16 h was adequate for extracting Po, and a shorter or longer extraction time led to lower recoveries of total P and Po, or led to the degradation of Po. An ideal P recovery rate and good-quality NMR spectra were obtained at a sediment:solution ratio of 1:10, showing that this ratio is ideal for extracting Po. An extractant solution of 0.25 M NaOH and 50 mM EDTA was found to be more appropriate than either NaOH on its own, or a more concentrated NaOH-EDTA mixture for (31P-NMR analysis, as this combination minimized interference from paramagnetic ions and was appropriate for the detected range of Po concentrations. The most appropriate preparation method for Po analysis, therefore, was to extract the freeze-dried and ground sediment sample with a 0.25 M NaOH and 50 mM EDTA solution at a sediment:solution ratio of 1:10, for 16 h, by shaking. As lyophilization of the NaOH-EDTA extracts proved to be an optimal pre-concentration method for Po analysis in the river sediment, the extract was lyophilized as soon as possible, and analyzed by (31P-NMR.

  19. Buffer-free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions: from protein buffer capacity prediction to bioprocess applications.

    Science.gov (United States)

    Bahrenburg, Sven; Karow, Anne R; Garidel, Patrick

    2015-04-01

    Protein therapeutics, including monoclonal antibodies (mAbs), have significant buffering capacity, particularly at concentrations>50 mg/mL. This report addresses pH-related issues critical to adoption of self-buffered monoclonal antibody formulations. We evaluated solution conditions with protein concentrations ranging from 50 to 250 mg/mL. Samples were both buffer-free and conventionally buffered with citrate. Samples were non-isotonic or adjusted for isotonicity with NaCl or trehalose. Studies included accelerated temperature stability tests, shaking stability studies, and pH changes in infusion media as protein concentrate is added. We present averaged buffering slopes of capacity that can be applied to any mAb and present a general method for calculating buffering capacity of buffer-free, highly concentrated antibody liquid formulations. In temperature stability tests, neither buffer-free nor conventionally buffered solution conditions showed significant pH changes. Conventionally buffered solutions showed significantly higher opalescence than buffer-free ones. In general, buffer-free solution conditions showed less aggregation than conventionally buffered solutions. Shaking stability tests showed no differences between buffer-free and conventionally buffered solutions. "In-use" preparation experiments showed that pH in infusion bag medium can rapidly approximate that of self-buffered protein concentrate as concentrate is added. In summary, the buffer capacity of proteins can be predicted and buffer-free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. High-throughput analysis for preparation, processing and analysis of TiO{sub 2} coatings on steel by chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Cuadrado Gil, Marcos, E-mail: Marcos.cuadradogil@ugent.be [SCRIPTS - Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 (S3) (Belgium); Van Driessche, Isabel, E-mail: Isabel.VanDriessche@ugent.be [SCRIPTS - Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 (S3) (Belgium); Van Gils, Sake, E-mail: Sake.Vangils@arcelormittal.com [OCAS - ArcelorMittal Gent R and D Centre, Pres. J.F. Kennedylaan 3, Zelzate B-9060 (Belgium); Lommens, Petra, E-mail: Petra.Lommens@ugent.be [SCRIPTS - Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 (S3) (Belgium); Castelein, Pieter, E-mail: Pieter.Castelein@flamac.be [Flamac - A Division of SIM, Technologiepark 903, Zwijnaarde 9052 (Belgium); De Buysser, Klaartje, E-mail: Klaartje.DeBuysser@ugent.be [SCRIPTS - Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 (S3) (Belgium)

    2012-11-05

    Highlights: Black-Right-Pointing-Pointer High-throughput preparation of TiO{sub 2} aqueous precursors. Black-Right-Pointing-Pointer Analysis of stability and surface tension. Black-Right-Pointing-Pointer Deposition of TiO{sub 2} coatings. - Abstract: A high-throughput preparation, processing and analysis of titania coatings prepared by chemical solution deposition from water-based precursors at low temperature ( Almost-Equal-To 250 Degree-Sign C) on two different types of steel substrates (Aluzinc Registered-Sign and bright annealed) is presented. The use of the high-throughput equipment allows fast preparation of multiple samples saving time, energy and material; and helps to test the scalability of the process. The process itself includes the use of IR curing for aqueous ceramic precursors and possibilities of using UV irradiation before the final sintering step. The IR curing method permits a much faster curing step compared to normal high temperature treatments in traditional convection devices (i.e., tube furnaces). The formulations, also prepared by high-throughput equipment, are found to be stable in the operational pH range of the substrates (6.5-8.5). Titanium alkoxides itself lack stability in pure water-based environments, but the presence of the different organic complexing agents prevents it from hydrolysis and precipitation reactions. The wetting interaction between the substrates and the various formulations is studied by the determination of the surface free energy of the substrates and the polar and dispersive components of the surface tension of the solutions. The mild temperature program used for preparation of the coatings however does not lead to the formation of pure crystalline material, necessary for the desired photocatalytic and super-hydrophilic behavior of these coatings. Nevertheless, some activity can be reported for these amorphous coatings by monitoring the discoloration of methylene blue in water under UV irradiation.

  1. Effect of starting solution acidity on the characteristics of CoFe2O4 powders prepared by solution combustion synthesis

    Science.gov (United States)

    Pourgolmohammad, B.; Masoudpanah, S. M.; Aboutalebi, M. R.

    2017-02-01

    Cobalt ferrite (CoFe2O4) nanoparticles were synthesized at the different pH values of starting solution, adjusted by NH4OH, using solution combustion method. Theoretical calculations and Fourier transform infrared spectroscopy analysis were carried out for determination and controlling the chelated species in solution. The phase evolution, surface area, morphology and magnetic properties of the combusted CoFe2O4 powders have been investigated by thermal analysis, X-ray diffractometry, electron microscopy, adsorption-desorption and vibrating sample magnetometer. The combustion rate mainly depends on pH which affects the phase and crystallite size. Furthermore, the specific surface area of the porous CoFe2O4 powders decreases from 66.25 to 27.09 m2/g by the increase of pH from 2 to 10. The combusted CoFe2O4 powders exhibit ferromagnetic properties which the highest saturation magnetization of 63.7 emu/g was achieved at pH of 2. Furthermore, the coercivity increases from 1112 to 1225 Oe by the increase of pH due to the decreasing of crystallite size.

  2. Protoplasts Surviving Freezing to −196 C and Osmotic Dehydration in 5 Molar Salt Solutions Prepared from the Bark of Winter Black Locust Trees 1

    Science.gov (United States)

    Siminovitch, David

    1979-01-01

    Free protoplasts were prepared from the living bark tissue of the trunk of summer and winter black locust trees by enzymic digestion of thin slices of the tissue for 3 hours in a medium containing 2% Onozuka cellulase, 2% Rhozyme pectinase, and 2% Driselase in mannitol solutions using 0.4 molar mannitol for summer tissue and 1.0 molar mannitol for winter tissues. Cleaned suspensions of protoplasts and also thin slices of tissue with cells intact were frozen to temperatures of −10 C, −20 C, −30 C, −40 C and liquid nitrogen in sucrose and balanced salt solutions. Similar suspensions of protoplasts were also subjected to strong osmotic dehydration (plasmorrhysis) in a series of balanced salt solutions of increasing molarity. Tests for survival showed that protoplasts retain the same properties of either extreme susceptibility or extreme resistance to injury by freezing or osmotic dehydration as the cells from which they are prepared. Winter protoplasts showed capability for tolerating freezing to −196 C and plasmorrhysis in 5 molar salt solutions. These results indicate that protoplasts are a valid and useful system for investigating the properties of the protoplasm and surface membranes associated with the seasonal development of extreme hardiness in the cells of woody plants. Images PMID:16660800

  3. Preparation and application of cross-linked core-shell PBA/PS and PBA/PMMA nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Zeng Zhong; Yu Jian; Guo Zhaoxia; Li Ying

    2006-01-01

    This paper reports the preparation of crosslinked core-shell poly(butyl acrylate )/polystyrene (PBA/PS)and poly(butyl acrylate)/poly(methyl methacrylate) (PBA/PMMA) nanoparticles via seeded emulsion polymerization and their application in nylon-based composites.A highly cross-linked structure was formed in both the cores and the shells by using a cross-linking agent,which could prevent the migration of hydrophobic PS shells tO the inside of particles.There were covalent bonds on the interfaces between the cores and the shells of both particles.The average particle sizes were 40-50 nm,and the size distributions were narrow.The kinetics of polymerization was investigated.Well-defined core-shell structure and narrow particle size distribution could be achieved under starved conditions of monomer feeding.Furthermore,PBA/PMMA particles were used to fill nylon 6,good dispersion was obtained because of the strong interfacial interaction between the nanoparticles and the nylon 6 matrix and the good deformation ability of nanoparticles,and the toughness and rigidity of the composites were improved evidently.

  4. Characterization of nanostructured alpha-Fe2O3-SnO2 solid solutions prepared by high energy ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lin, R.; Mørup, Steen

    1998-01-01

    Solid solutions of SnO2 in alpha-Fe2O3 with SnO2 contents up to 20+-4 mol% have been prepared by mechanical alloying of alpha-Fe2O3 and SnO2 powder blends. X-ray diffraction and Mossbauer spectroscopy investigations show that the mechanical milling results in alloying on an atomic scale...... and that true solid solution formation occurs. We suggest that the high defect concentration and the chemical enthalpy of Fe3+ -O2- -Sn4+ interfaces between nanostructured alpha-Fe2O3 and SnO2 regions may serve as a driving force for the formation of a solid solution in the immiscible ceramic system....

  5. Characterization of nanostructured alpha-Fe2O3-SnO2 solid solutions prepared by high energy ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lin, R.; Mørup, Steen

    1998-01-01

    Solid solutions of SnO2 in alpha-Fe2O3 with SnO2 contents up to 20+-4 mol% have been prepared by mechanical alloying of alpha-Fe2O3 and SnO2 powder blends. X-ray diffraction and Mossbauer spectroscopy investigations show that the mechanical milling results in alloying on an atomic scale...... and that true solid solution formation occurs. We suggest that the high defect concentration and the chemical enthalpy of Fe3+ -O2- -Sn4+ interfaces between nanostructured alpha-Fe2O3 and SnO2 regions may serve as a driving force for the formation of a solid solution in the immiscible ceramic system....

  6. A Randomized Prospective Study of Bowel Preparation for Colonoscopy with Low-Dose Sodium Phosphate Tablets versus Polyethylene Glycol Electrolyte Solution

    Directory of Open Access Journals (Sweden)

    Erina Kumagai

    2014-01-01

    Full Text Available Optimal bowel preparation is essential for the safety and outcome of colonoscopy. A solution containing polyethylene glycol (PEG is often used as a bowel cleansing agent, but some patients are intolerant of PEG, and this may lead to discontinuation of colonoscopy. Sodium phosphates (NaP tablets are designed to improve patient acceptance and compliance. The objective of this study was to compare bowel preparation efficiency and patient acceptance of a 30 NaP tablet preparation (L-NaP and a 2 L PEG preparation. Patients were randomized into either the L-NaP or PEG group. The primary endpoint was the efficiency of colon cleansing as assessed by a validated four-point scale according to the Aronchick scale by endoscopists and was verified by blinded investigators. The secondary endpoints were patients’ tolerability and acceptance. Colon-cleansing efficiency was not significantly different between the two preparations. However, patients’ overall judgment was significantly in favor of L-NaP, reflecting better acceptance of L-NaP than PEG. Additionally, more patients favored L-NaP over PEG in a hypothetical future occasion requiring colonoscopy.

  7. Stable dispersion of graphene solution prepared by hydrothermai reduction%高压釜热还原制备稳定分散的石墨烯溶液

    Institute of Scientific and Technical Information of China (English)

    冉启燕; 张海燕; 陈易明; 叶剑; 李春辉

    2012-01-01

    A improved Hummers method was employed to prepare graphite oxide using natural flake graphite as raw materials. The graphene oxide solution was prepared by ultrasonic dispersion, and the pH value of solution was changed through adding different volume fraction of hydrazine hydrate. After hydrothermal reduction in au- toclave, stable dispersion graphene solutions were obtained. The as prepared samples were characterized by X- ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, atomic force microscope, zeta potential and optical microscope. The influence of temperature and pH value of the sta- bility of graphene solutions was investigated.%以天然鳞片石墨为原料,用改进的Hummers法制备氧化石墨。超声分散制备氧化石墨烯溶液,通过加入不同量的水合肼调节溶液的pH值,再通过水热法热还原,制备了在水中稳定分散的石墨烯溶液。利用扫描电子显微镜(SEM)、高分辨透射电镜(HR-TEM)、拉曼光谱(Raman)、原子力显微镜(AFM)、X射线衍射分析(XRD)、zeta电位及光学显微镜对制备的样品进行了表征,研究了不同温度、pH值对石墨烯溶液稳定性的影响。

  8. Method for the preparation of cellulose acetate flat sheet composite membranes for forward osmosis—Desalination using MgSO4 draw solution

    KAUST Repository

    Sairam, M.

    2011-06-01

    A lab scale method for the preparation of defect free flat sheet composite membranes for forward osmosis (FO) has been developed. Membranes containing a thin layer of cellulose acetate (CA) cast on a nylon fabric of 50μm thick were prepared by phase inversion in water. Cellulose acetate (CA) membranes with an overall thickness of 70-80μm have been prepared with lactic acid, maleic acid and zinc chloride as pore forming agents, at different annealing temperatures, for forward osmosis. These membranes have been tested in the desalination of saline feeds (35g·L-1 of NaCl) using magnesium sulphate solution (150g·L-1) as the draw solution. The water flux, and rejection of NaCl, were compared with those of commercially available membranes tested under the same FO conditions. The commercially available FO membrane from Hydration Technologies Inc, OR (M1) has a permeability of 0.13L·h-1·m-2·bar-1 with a NaCl rejection of 97% when tested with 150g·L-1 of MgSO4 in the draw solution. Another commercially available membrane for FO from Hydration Technologies Inc, OR, M2 has a water permeability of 0.014L·h-1·m-2·bar-1 with NaCl rejection of 100%. The flux and rejection of the CA membranes prepared in this work are found to be dependent on the nature of the pore forming agent, and annealing temperature. Impregnation of an inorganic filler, sodium montmorrillonite in CA membranes and coating of CA membranes with hydrophilic PVA did not enhance the flux of base CA membranes. Cellulose acetate membranes cast from dope solutions containing acetone/isopropanol and lactic acid, maleic acid and zinc chloride as pore forming agents have water permeabilities of 0.13, 0.09 and 0.68L·h-1·m-2·bar-1 respectively, with NaCl rejections of 97.7, 99.3 and 88% when annealed at 50°C. CA membranes prepared with zinc chloride as a pore forming agent have good permeability of 0.27L·h-1·m-2·bar-1 with a NaCl rejection of 95% when annealed at 70°C. © 2011.

  9. Reclamation of zinc-contaminated soil using a dissolved organic carbon solution prepared using liquid fertilizer from food-waste composting.

    Science.gov (United States)

    Chiang, Po-Neng; Tong, Ou-Yang; Chiou, Chyow-San; Lin, Yu-An; Wang, Ming-Kuang; Liu, Cheng-Chung

    2016-01-15

    A liquid fertilizer obtained through food-waste composting can be used for the preparation of a dissolved organic carbon (DOC) solution. In this study, we used the DOC solutions for the remediation of a Zn-contaminated soil (with Zn concentrations up to 992 and 757 mg kg(-1) in topsoil and subsoil, respectively). We then determined the factors that affect Zn removal, such as pH, initial concentration of DOC solution, and washing frequency. Measurements using a Fourier Transform infrared spectrometer (FT-IR) revealed that carboxyl and amide were the major functional groups in the DOC solution obtained from the liquid fertilizer. Two soil washes using 1,500 mg L(-1) DOC solution with a of pH 2.0 at 25°C removed about 43% and 21% of the initial Zn from the topsoil and subsoil, respectively. Following this treatment, the pH of the soil declined from 5.4 to 4.1; organic matter content slightly increased from 6.2 to 6.5%; available ammonium (NH4(+)-N) content increased to 2.4 times the original level; and in the topsoil, the available phosphorus content and the exchangeable potassium content increased by 1.65 and 2.53 times their initial levels, respectively.

  10. Iron-based adsorbent prepared from Litchi peel biomass via pyrolysis process for the removal of pharmaceutical pollutant from synthetic aqueous solution.

    Science.gov (United States)

    Foletto, Vitória Segabinazzi; Ferreira, Ananda Bulegon; da Cruz Severo, Eric; Collazzo, Gabriela Carvalho; Foletto, Edson Luiz; Dotto, Guilherme Luiz

    2017-03-10

    A porous iron-based adsorbent obtained from litchi peel via pyrolysis process was prepared in this work, in order to evaluate its adsorptive potential for the removal of a pharmaceutical dye (amaranth) from aqueous solution. The material was characterized by X-ray diffraction, nitrogen adsorption-desorption isotherms, and scanning electron microscopy. Several isotherm and kinetic models were tested aiming to represent the amaranth dye adsorption. The prepared sample presented magnetic property, and a mesoporous texture constituted of graphite and three iron-based phases. The adsorption kinetics of amaranth on the adsorbent followed the pseudo-second-order model, whereas the equilibrium data were in good agreement with the BET isotherm, being represented by a sigmoid-shaped adsorption isotherm. The maximum adsorption capacity for the amaranth dye was found to be 44.87 mg g(-1), demonstrating that the material prepared in this work showed to be a promising adsorbent for the removal of amaranth from aqueous solution.

  11. Nitrate conversion and supercritical fluid extraction of UO{sub 2}-CeO{sub 2} solid solution prepared by an electrolytic reduction-coprecipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, L.Y. [Tsinghua Univ., Beijing (China). Inst. of Nuclear and New Energy Technology; China Institute of Atomic Energy, Beijing (China); Duan, W.H.; Wen, M.F.; Xu, J.M.; Zhu, Y.J. [Tsinghua Univ., Beijing (China). Inst. of Nuclear and New Energy Technology

    2014-04-01

    A low-waste technology for the reprocessing of spent nuclear fuel (SNF) has been developed recently, which involves the conversion of actinide and lanthanide oxides with liquid N{sub 2}O{sub 4} into their nitrates followed by supercritical fluid extraction of the nitrates. The possibility of the reprocessing of SNF from high-temperature gas-cooled reactors (HTGRs) with nitrate conversion and supercritical fluid extraction is a current area of research in China. Here, a UO{sub 2}-CeO{sub 2} solid solution was prepared as a surrogate for a UO{sub 2}-PuO{sub 2} solid solution, and the recovery of U and Ce from the UO{sub 2}-CeO{sub 2} solid solution with liquid N{sub 2}O{sub 4} and supercritical CO{sub 2} containing tri-n-butyl phosphate (TBP) was investigated. The UO{sub 2}-CeO{sub 2} solid solution prepared by electrolytic reduction-coprecipitation method had square plate microstructures. The solid solution after heat treatment was completely converted into nitrates with liquid N{sub 2}O{sub 4}. The XRD pattern of the nitrates was similar to that of UO{sub 2}(NO{sub 3}){sub 2} . 3H{sub 2}O. After 120 min of online extraction at 25 MPa and 50 , 99.98% of the U and 98.74% of the Ce were recovered from the nitrates with supercritical CO{sub 2} containing TBP. The results suggest a promising potential technology for the reprocessing of SNF from HTGRs. (orig.)

  12. Preparation and solution behavior of a thermoresponsive diblock copolymer of poly(ethyl glycidyl ether) and poly(ethylene oxide).

    Science.gov (United States)

    Ogura, Michihiro; Tokuda, Hiroyuki; Imabayashi, Shin-ichiro; Watanabe, Masayoshi

    2007-08-28

    A thermoresponsive diblock copolymer, poly(ethyl glycidyl ether)-block-poly(ethylene oxide) (PEGE-b-PEO), is synthesized by successive anionic ring-opening polymerization of ethyl glycidyl ether and ethylene oxide using 2-phenoxyethanol as a starting material, and its solution behavior is elucidated in water. In a dilute 1 wt % solution, the temperature-dependent alteration in the polymer hydrodynamic radius (RH) is measured in the temperature range between 5 and 45 degrees C by pulse-gradient spin-echo NMR and dynamic light scattering. The RH value increased with temperature in two steps, where the first step at 15 degrees C corresponds to the core-shell micelle formation and the second step at 40 degrees C corresponds to the aggregation of the core-shell micelles. The formation of the core-shell micelles is supported by the solubilization of a dye (1,6-diphenyl-1,3,5-hexatriene) in the hydrophobic core, which is recognized for a copolymer solution in the temperature range between 20 and 40 degrees C. In this temperature range, the core-shell micelles and the unimers coexist and the fraction of the former gradually increases with increasing temperature, suggesting equilibrium between the micelles and the unimers. In the concentrated regime (40 wt % solution), the solution forms a gel and the small-angle X-ray scattering measurements reveal the successive formation of hexagonal and lamellar liquid crystal phases with increasing temperature.

  13. Physical chemical and citotoxic evaluation of highly diluted solutions of Euphorbia tirucalli L. prepared through the fifty milesimal homeopathic method

    Directory of Open Access Journals (Sweden)

    Carlos Renato Zacharias

    2010-07-01

    Full Text Available Background: although Hahnemann described the fifty-milesimal (LM method in the 6th edition of the Organon of the Medical Art, very little research has been carried out on the physical chemical properties of these homeopathic preparations. Furthermore, there is still no evidence allowing for the correlation between the alleged physical chemical properties and the biological effects of high dilutions. Aims: to evaluate physical chemical characteristics of LM preparations including electrical conductivity, pH and refraction index, and their effect on biological experimental models. Materials and methods: preparations tested for physical chemical analysis were dilutions 1 lm to 10 lm of Euphorbia tirucalli L. prepared from the latex and the juice of the plant. To rule the seasonal characteristics of this plant, 2 different populations were used, one collected in June 2007 and the other in May 2008. Furthermore, the cytotoxic effect of Euphorbia tirucalli 5 lm was tested on human breast cancer cells (MCF7 through MTT assay. Some differences among the two collections were observed. However, any clear correlation could be observed between physical chemical properties and biological activity.

  14. Insight into selective removal of copper from high-concentration nickel solutions with XPS and DFT: New technique to prepare 5N-nickel with chelating resin.

    Science.gov (United States)

    Tao, Xuewen; Liu, Fuqiang; Bai, Zhiping; Wei, Dongyang; Zhang, Xiaopeng; Wang, Junfei; Gao, Jie; Sun, Xiaowen; Li, Baohua; Li, Chenghui; Li, Aimin

    2016-10-01

    An efficient and profitable separation process was proposed to prepare 5N (the purity of the metal solution reaches 99.999%) high-purity nickel from 3N nickel-solutions using Purolite S984. The adsorption performance of this superior resin, especially its selectivity for metal ions, was explored quantitatively. The maximum adsorption capacity for copper was 2.286mmol/g calculated by the Langmuir model, which was twice as large as that for nickel. In the binary systems, the adsorption capacity for nickel was decreased by 45%, indicating direct competition for the active sites. The infinite separation factor for copper versus nickel exceeded 300, revealing the feasibility of preparing 5N-level high-purity nickel solutions, which was further verified using the 800BV (bed volume) effluent in the column dynamic process. According to the cost-benefit analysis, purification contributed to a profit of approximately 60,000USD per cycle, and the investment return period was less than 1/3years. Density functional theory analysis confirmed that four nitrogen atoms would be involved in the coordination complex and thus a structure involving two five-membered rings could be achieved. The X-ray photoelectron spectra confirmed the involvement of nitrogen atoms, implying a coordination ratio of approximately 1:1.

  15. Preparation of Cu-Al layered double hydroxide intercalated with ethylenediaminetetraacetate by coprecipitation and its uptake of rare earth ions from aqueous solution

    Science.gov (United States)

    Kameda, Tomohito; Hoshi, Kazuaki; Yoshioka, Toshiaki

    2013-03-01

    A Cu-Al layered double hydroxide intercalated with ethylenediaminetetraacetate (edta•Cu-Al LDH) was prepared by the dropwise addition of a Cu-Al nitrate solution to an edta solution at constant pH values of 8.0, 9.0, and 10.0. The edta•Cu-Al LDH had Hedta3- in the interlayer. Furthermore, the preparation at pH 8.0 resulted in the intercalation of Cu(edta)2-. The edta•Cu-Al LDH was found to take up rare earth ions from aqueous solution. The uptake of Sc3+ and Y3+ by edta•Cu-Al LDH was attributed to both the chelating functions of the edta ion in the interlayer and the chemical properties of Cu-Al LDH itself. The uptake of La3+ by edta•Cu-Al LDH was primarily caused by the chelating function of edta ions in the interlayer. The edta ions in the edta•Cu-Al LDH interlayer formed chelate complexes in the order Sc3+ > Y3+ > La3+ due to their relative stabilities, Sc(edta)- > Y(edta)- > La(edta)-. Thus, edta ions retain their chelating function even when intercalated in a Cu-Al LDH interlayer.

  16. PREPARATION OF NANOMETER TiO2 ORGANIC SOLUTION-EFFECT OF ORGANIC SILOXANE ON SOL PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Bi-yao Wu; Dao-hong Zhang

    2004-01-01

    A homogeneous longtime stabilized transparent nanometer TiO2 organic solution was obtained by means of the simultaneous hydrolysis and co-polycodensation of tetrabutyltitanate (TBT) and methacryloxypropyltrimethoxysilane (MAPTMS) by the sol-gel process. The particle size of nanometer titanium dioxide was controlled by use of bifunctional silanes, such as diphenyldimethoxysilane (DPDMS), diphenyldiethoxysilane (DPDES) and dimethyldiethoxysilane (DMDES). The effect of TiO2 content in the solution on the refractive index of system was discussed in detail. The result shows that the refractive index of solution increases linearly with TiO2 content. The refractive index of the three hybrid nanorneter materials attained 1.6053, 1.5846 and 1.5346, respectively. The size of nanometer particles was characterized by TEM and the particle diameter thus obtained is in the range of 20-90 nm. FT-IR spectra of the materials show that the TiO-Si bond is formed.

  17. Preparation of grain size controlled boron-doped diamond thin films and their applications in selective detection of glucose in basic solutions

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Boron-doped diamond (BDD) thin films with different crystal grain sizes were prepared by controlling the reacting gas pressure using hot filament chemical vapor deposition (HFCVD).The morphologies and structures of the prepared diamond thin films were characterized by scanning electron microscopy (SEM) and Raman spectroscopy.The electrochemical responses of K4Fe(CN)6 on different BDD electrodes were investigated.The results suggested that electron transfer was faster at the boron-doped nanocrystalline diamond (BDND) thin film electrodes in comparison with that at other BDD thin film electrodes.The prepared BDD thin film electrodes without any modification were used to directly detect glucose in the basic solution.The results showed that the as-prepared BDD thin film electrodes exhibited good selectivity for detecting glucose in the presence of ascorbic acid (AA) and uric acid (UA).The higher sensitivity was observed on the BDND thin film grown on the boron-doped microcrystalline diamond (BDMD) thin film surface,and the linear response range,sensitivity and the low detection limit were 0.25–10 mM,189.1 μA mmol-1 cm-2 and 25 μM (S/N=3) for glucose in the presence of AA and UA,respectively.

  18. 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 coa

  19. Synthesis and photoluminescence properties of CaSixOy:Tb3+ phosphors prepared using solution-combustion method

    CSIR Research Space (South Africa)

    Dejene, FB

    2011-07-01

    Full Text Available Effect of Tb3+ ion concentrations on the structural and persistence luminescence properties of CaSixOy:Tb3+ crystals were evaluated using powders grown by the solution combustion technique. The XRD study indicates the change of phase from CaSiO3...

  20. Pre-Service Chemistry Teachers' Competencies in the Laboratory: A Cross-Grade Study in Solution Preparation

    Science.gov (United States)

    Karatas, F. O.

    2016-01-01

    One of the prerequisites for chemistry teacher candidates is to demonstrate certain laboratory skills. This article aims to determine and discuss the competencies of pre-service chemistry teachers in a chemistry laboratory context working with solution chemistry content. The participants in this study consisted of a group of pre-service chemistry…

  1. [In vitro study of the flow duration of antibiotics solutions prepared in elastomeric infusion devices: effect of cold storage for 3 to 7days].

    Science.gov (United States)

    Grangeon-Chapon, C; Robein-Dobremez, M-J; Pin, I; Trouiller, P; Allenet, B; Foroni, L

    2015-09-01

    Within the cystic fibrosis patients' home care, EMERAA network ("Together against Cystic fibrosis in Rhone-Alpes and Auvergne") organizes parenteral antibiotics cures at home prepared in elastomeric infusion devices by hospital pharmacies. However, patients and nurses found that the durations of infusion with these devices were often longer than the nominal duration of infusion indicated by their manufacturer. This study aimed to identify the potential different causes in relation to these discordances. Three hundred and ninety devices of two different manufacturers are tested in different experimental conditions: three antibiotics each at two different doses, duration of cold storage (three days or seven days) or immediate tests without cold storage, preparation and storage of the solution in the device (protocol Device) or transfer in the device just before measurement (protocol Pocket). All tests highlighted a longer flow duration for devices prepared according to the protocol Device versus the protocol Pocket (P=0.004). Flow duration is increased in the case of high doses of antibiotics with high viscosity such as piperacilline/tazobactam. The results of this in vitro study showed the impact of: (1) the time between the filling of the device and the flow of the solution; (2) cold storage of elastomeric infusion devices; (3) concentration of antibiotics and therefore the viscosity of the solution to infuse. It is therefore essential that health care teams are aware of factors, which may lead to longer infusion durations with these infusion devices. When the additional time for infusion remain acceptable, it should be necessary to inform the patient and to relativize these lengthening compared to many benefits that these devices provide for home care. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  2. Bowel Preparation for Colonoscopy with Sodium Phosphate Solution versus Polyethylene Glycol-Based Lavage: A Multicenter Trial

    Directory of Open Access Journals (Sweden)

    S. Schanz

    2008-01-01

    Full Text Available Background: Adequate bowel preparation is essential for accurate colonoscopy. Both oral sodium phosphate (NaP and polyethylene glycol-based lavage (PEG-ELS are used predominantly as bowel cleansing modalities. NaP has gained popularity due to low drinking volume and lower costs. The purpose of this randomized multicenter observer blinded study was to compare three groups of cleansing (NaP, NaP + sennosides, PEG-ELS + sennosides in reference to tolerability, acceptance, and cleanliness. Patient and Methods: 355 outpatients between 18 and 75 years were randomized into three groups (A, B, C receiving NaP = A, NaP, and sennosides = B or PEG-ELS and sennosides = C. Gastroenterologists performing colonoscopies were blinded to the type of preparation. All patients documented tolerance and adverse events. Vital signs, premedication, completeness, discomfort, and complications were recorded. A quality score (0–4 of cleanliness was generated. Results: The three groups were similar with regard to age, sex, BMI, indication for colonoscopy, and comorbidity. Drinking volumes (L (A = 4.33 + 1.2, B = 4.56 + 1.18, C = 4.93 + 1.71 were in favor of NaP (P = .005. Discomfort from ingested fluid was recorded in A = 39.8% (versus C: P = .015, B = 46.6% (versus C: P = .147, and C = 54.6%. Differences in tolerability and acceptance between the three groups were statistically not significant. No differences in adverse events and the cleanliness effects occurred in the three groups (P = .113. The cleanliness quality scores 0–2 were calculated in A: 77.7%, B: 86.7%, and C: 85.2%. Conclusions: These data fail to demonstrate significant differences in tolerability, acceptance, and preparation quality between the three types of bowel preparation for colonoscopy. Cleansing with NaP was not superior to PEG-ELS.

  3. Adsorption of heavy metal ion from aqueous solution by nickel oxide nano catalyst prepared by different methods

    Directory of Open Access Journals (Sweden)

    Amira M. Mahmoud

    2015-03-01

    Full Text Available Environmental pollution by heavy metal is arising as the most endangering tasks to both water sources and atmosphere quality today. The treatment of heavy metals is of special concern due to their recalcitrance and persistence in the environment. To limit the spread of the heavy metals within water sources, nickel oxide nanoparticles adsorbents were synthesized and characterized with the aim of removal of one of the aggressive heavy elements, namely; lead ions. Nano nickel oxide adsorbents were prepared using NaOH and oxalic acid dissolved in ethanol as precursors. The results indicated that adsorption capacity of Pb(II ion by NiO-org catalyst is favored than that prepared using NaOH as a precipitant. Nickel oxide nanoparticles prepared by the two methods were characterized structurally and chemically through XRD, DTA, TGA, BET and FT-IR. Affinity and efficiency sorption parameters of the solid nano NiO particles, such as; contact time, initial concentration of lead ions and the dosage of NiO nano catalyst and competitive adsorption behaviors were studied. The results showed that the first-order reaction law fit the reduction of lead ion, also showed good linear relationship with a correlation coefficient (R2 larger than 0.9.

  4. Recent Trends in Preparation of Poly(lactide-co-glycolide Nanoparticles by Mixing Polymeric Organic Solution with Antisolvent

    Directory of Open Access Journals (Sweden)

    Edel Sah

    2015-01-01

    Full Text Available In recent years, there have been a plethora of nanoengineering approaches for the development of poly(lactide-co-glycolide (PLGA nanoparticulate carrier systems. However, overlooking the multifaceted issues in the preparation and characterization of PLGA-based nanoparticles, many reports have been focused on their in vivo behaviors. It is imperative to fully assess technological aspects of a nanoencapsulation method of choice and to carefully evaluate the nanoparticle quality. The selection of a nanoencapsulation technique should consider drug property, nanoparticle quality, scale-up feasibility, manufacturing costs, personnel safety, environmental impact, waste disposal, and the like. Made in this review are the fundamentals of classical emulsion-templated nanoencapsulation methods used to prepare PLGA nanoparticles. More specifically, this review provides insight into emulsion solvent evaporation/extraction, salting-out, nanoprecipitation, membrane emulsification, microfluidic technology, and flow focusing. Innovative nanoencapsulation techniques are being developed to address many challenges existing in the production of PLGA-based nanoparticles. In addition, there are various out-of-the-box approaches for the development of novel PLGA hybrid systems that could deliver multiple drugs. Latest trends in these areas are also dealt with in this review. Relevant information might be helpful to those who prepare and develop PLGA-based nanoparticles that meet their specific demands.

  5. Preparation of a new sorbent with hydrated lime and blast furnace slag for phosphorus removal from aqueous solution.

    Science.gov (United States)

    Gong, Guozhuo; Ye, Shufeng; Tian, Yajun; Wang, Qi; Ni, Jiandi; Chen, Yunfa

    2009-07-30

    The removal of dissolvable inorganic phosphate (H(2)PO(4)(-)) by sorbents prepared from hydrated lime (HL) and blast furnace slag (BFS) was fundamentally studied by an orthogonal experiment design. Based on statistic analysis, it is revealed that the weight ratio of BFS/HL is the most significant variable, and an optimized preparation condition is figured out. With the increase of HL content, the adsorption capacity increases, suggesting that the HL plays the important role in the removal process in the gross. However, in the lower HL content, it is interesting that the adsorption capacity of as-prepared sorbents exceed the sum of the capacities of the same ratio of BFS and HL. The further analysis indicate the excess capacities linearly depend on the specific surface area of sorbents, suggesting that the removal of H(2)PO(4)(-) is closely related with the microstructure of sorbents in the lower HL content, according to the characterization with SEM, XRD and pore analysis. Additionally, an adsorption model and kinetic are discussed in this paper.

  6. Preparation and Characterization of Self-Reinforced Antibacterial and Oil-Resistant Paper Using a NaOH/Urea/ZnO Solution

    OpenAIRE

    Li Jiao; Jinxia Ma; Hongqi Dai,

    2015-01-01

    This paper describes self-reinforced antibacterial and oil-resistant properties that were successfully prepared by surface selective dissolution of filter paper in a NaOH/Urea/ZnO (weight ratio of 8:12:0.25) aqueous solution. The effect of the processing time on the mechanical properties of this paper was evaluated at -12°C. The paper morphologies were characterized using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray pho...

  7. Advancing Climate Change Education and Youth Empowerment: Preparing Our Communities with the Skills, Knowledge, and Passion to Push for and Develop Innovative Solutions

    Science.gov (United States)

    Niepold, F., III; Johnston, E.; Rooney-varga, J. N.; Qusba, L.; Staveloz, W.; Poppleton, K.; Cloyd, E. T.; Kretser, J.; Bozuwa, J.; Edkins, M. T.

    2016-12-01

    Today's youth are the first generation to come of age amid rapid climate change, and they have the most at stake in how society responds to it. Climate change will bring economic and environmental challenges as well as opportunities, and citizens who understand the issues at stake will be better prepared to respond. Climate education is a necessary foundation for them to understand and help tackle the complex issue of climate change. Many will become leaders with the skills, knowledge, and passion to push for and develop innovative solutions. As such, this topic requires interdisciplinary and transdisciplinary approaches from a professionally diverse group of experts to effectively build the solid foundation for a low carbon and sustainable economy. Educators from all disciplines need to be enlisted to contribute their talents in building students knowledge and skills to limit human-induced climate change while being prepared for the projected impacts that will continue, and it will accelerate significantly if global emissions of heat-trapping gases continue to increase. This presentation will discuss the new youth and educator engagement partnerships that developed to achieve ways of addressing the problems and opportunities resulting from climate change. We will describe how the partnerships are helping lift up and raise the profile of effective programs that enable transdisciplinary solutions to societal issues. The #Youth4Climate and #Teach4Climate social media campaigns were organized by a flotilla of federal and non-federal partners to inspire young people around the world to take actions on climate change and inspire teachers to prepare students to be part of the solutions to climate change. The largest one, the #Youth4Climate campaign for COP21 youth engagement had over 33 million impressions and opened a discussion for all to join with youth for climate actions at COP21. Each of these three social media campaigns had a simple ask, give young people a voice

  8. Utilization of various agricultural wastes for activated carbon preparation and application for the removal of dyes and metal ions from aqueous solutions.

    Science.gov (United States)

    Kadirvelu, K; Kavipriya, M; Karthika, C; Radhika, M; Vennilamani, N; Pattabhi, S

    2003-03-01

    Activated carbons were prepared from the agricultural solid wastes, silk cotton hull, coconut tree sawdust, sago waste, maize cob and banana pith and used to eliminate heavy metals and dyes from aqueous solution. Adsorption of all dyes and metal ions required a very short time and gave quantitative removal. Experimental results show all carbons were effective for the removal of pollutants from water. Since all agricultural solid wastes used in this investigation are freely, abundantly and locally available, the resulting carbons are expected to be economically viable for wastewater treatment.

  9. Porous hydrogel of wool keratin prepared by a novel method: an extraction with guanidine/2-mercaptoethanol solution followed by a dialysis.

    Science.gov (United States)

    Ozaki, Yuki; Takagi, Yusuke; Mori, Hideki; Hara, Masayuki

    2014-09-01

    In this study, we show a novel simple method to prepare a sponge-like porous keratin hydrogel through the extraction of wool keratin in a solution containing guanidine hydrochloride and 2-mercaptoethanol followed by dialysis for both aggregation of keratin and recrosslink. The gel had a highly porous structure and a fast-swelling property in rehydration after freeze-drying. It had also high mechanical strength both in the tensile test and the measurement of dynamic viscoelasticity. Three types of animal cells, PC12 cells, HOS cells and murine embryonic fibroblasts, well attached and grew on the surface of the porous hydrogel.

  10. Carbons prepared from Spartina alterniflora and its anaerobically digested residue by H3PO4 activation: characterization and adsorption of cadmium from aqueous solutions.

    Science.gov (United States)

    Wang, Zhengfang; Nie, Er; Li, Jihua; Zhao, Yongjun; Luo, Xingzhang; Zheng, Zheng

    2011-04-15

    Two series of activated carbons were prepared from Spartina alterniflora and from its anaerobically digested residue by H(3)PO(4) activation at various process conditions, and used as adsorbents for the removal of cadmium (II) in aqueous solutions. The surface areas and pore volumes of carbons were derived from adsorption isotherms (N(2) at 77K). The surface chemistry of carbons was investigated by infrared spectroscopy. Comparison study indicated that physicochemical properties of the activated carbons were strongly dependent not only on activation conditions but also on biopolymer contents of precursors. Several isotherm models were investigated and the adsorption isotherm data were best represented by the Langmuir isotherm model, with a maximum monolayer adsorption capacity of 47.85 mg/g at 25 °C. The results showed that the activated carbon produced from S. alterniflora could be employed as a promising adsorbent for removing cadmium (II) from aqueous solutions.

  11. DNA Modified with Metal Nanoparticles: Preparation and Characterization of Ordered Metal-DNA Nanostructures in a Solution and on a Substrate

    Directory of Open Access Journals (Sweden)

    Nina Kasyanenko

    2016-01-01

    Full Text Available DNA interaction with silver and aluminum nanoparticles in a solution has been investigated with the AFM, SEM, dynamic light scattering, viscometry, and spectral methods. The comparison of DNA interaction with nanoparticles synthesized by the reduction of Ag+ ions and with nanoparticles obtained by the electric discharge plasma method was done. DNA metallization in a solution and on n-silicon surface with metal nanoparticles or by the reduction of silver ions after their binding to DNA was executed and studied. It was shown that DNA strands with regular location of silver or aluminum nanoparticles can be prepared. The conditions for the formation of silver nanoparticles and silver nanoclusters on DNA were analyzed.

  12. Preparation of conversion coating on Ti-6Al-4V alloy in mixed solution of phytic acid and ammonium fluoride through chemical modification

    Science.gov (United States)

    Li, Lanlan; He, Jian; Yang, Xu

    2016-05-01

    Conversion coatings on Ti-6Al-4V alloy was prepared through chemical modification in phytic acid and ammonium fluoride mixed solution. The influences of pH, time and the composition of solution on the microstructure of alloy surface were investigated. Scanning electron microscopy was used to observe the microstructure. The chemical composition of alloy surface before and after modification was investigated by energy dispersive X-ray spectroscopy. The results indicated that a conversion coating could be formed on the Ti-6Al-4V alloy in a mixed solution of phytic acid and ammonium fluoride, the growth and microstructure of the conversion coatings were critically dependent on the pH, time and concentration of phytic acid and ammonium fluoride. In 100 mg/ml phytic acid containing 125 mg/ml ammonium fluoride solution with a pH of 6, a compact conversion coating with the thickness of about 4.7 μm formed after 30 min immersion on Ti-6Al-4V alloy surface. The preliminary evaluation of bioactivity of conversion coating was performed by in vitro cell experiments. The results showed that this chemical modification method is a promising surface modification technique for Ti-6Al-4V alloy inplants.

  13. High Critical Current Density of YBa2Cu3O7-x Superconducting Films Prepared through a DUV-assisted Solution Deposition Process.

    Science.gov (United States)

    Chen, Yuanqing; Bian, Weibai; Huang, Wenhuan; Tang, Xinni; Zhao, Gaoyang; Li, Lingwei; Li, Na; Huo, Wen; Jia, Jiqiang; You, Caiyin

    2016-12-01

    Although the solution deposition of YBa2Cu3O7-x (YBCO) superconducting films is cost effective and capable of large-scale production, further improvements in their superconductivity are necessary. In this study, a deep UV (DUV) irradiation technique combined with a low-fluorine solution process was developed to prepare YBCO films. An acrylic acidic group as the chelating agent was used in the precursor solution. The acrylic acidic group was highly sensitive to DUV light at 254 nm and significantly absorbed UV light. The coated gel films exposed to DUV light decomposed at 150 °C and copper aggregation was prevented. The UV irradiation promoted the removal of the carbon residue and other by-products in the films, increased the density and enhanced the crystallinity and superconductivity of the YBCO films. Using a solution with F/Ba = 2, YBCO films with thicknesses of 260 nm and enhanced critical current densities of nearly 8 MA/cm(2) were produced on the LaAlO3 (LAO) substrates.

  14. High Critical Current Density of YBa2Cu3O7‑x Superconducting Films Prepared through a DUV-assisted Solution Deposition Process

    Science.gov (United States)

    Chen, Yuanqing; Bian, Weibai; Huang, Wenhuan; Tang, Xinni; Zhao, Gaoyang; Li, Lingwei; Li, Na; Huo, Wen; Jia, Jiqiang; You, Caiyin

    2016-12-01

    Although the solution deposition of YBa2Cu3O7‑x (YBCO) superconducting films is cost effective and capable of large-scale production, further improvements in their superconductivity are necessary. In this study, a deep UV (DUV) irradiation technique combined with a low-fluorine solution process was developed to prepare YBCO films. An acrylic acidic group as the chelating agent was used in the precursor solution. The acrylic acidic group was highly sensitive to DUV light at 254 nm and significantly absorbed UV light. The coated gel films exposed to DUV light decomposed at 150 °C and copper aggregation was prevented. The UV irradiation promoted the removal of the carbon residue and other by-products in the films, increased the density and enhanced the crystallinity and superconductivity of the YBCO films. Using a solution with F/Ba = 2, YBCO films with thicknesses of 260 nm and enhanced critical current densities of nearly 8 MA/cm2 were produced on the LaAlO3 (LAO) substrates.

  15. Preparation and characterization of multi-walled carbon nanotubes/chitosan nanocomposite and its application for the removal of heavy metals from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Salam, Mohamed Abdel, E-mail: masalam16@hotmail.com [Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80200, Jeddah 21589 (Saudi Arabia); Makki, Mohamad S.I.; Abdelaal, Magdy Y.A. [Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80200, Jeddah 21589 (Saudi Arabia)

    2011-02-03

    Research highlights: > Nanocomposite made of multi-walled carbon nanotubes and chitosan was prepared and characterized. > The characterization confirmed the homogenous and well distribution of the MWCNTs within the chitosan matrix. > MWCNTs/chitosan nanocomposite was used for the removal of copper, zinc, cadmium and nickel ions from aqueous solution. > The results showed that nanocomposite could remove successfully most of the metal ions from solution with high efficiency. - Abstract: Multi-walled carbon nanotubes (MWCNTs) were modified with chitosan, and a homogenous nanocomposite was obtained. The morphological properties of the MWCNTs/chitosan nanocomposite were studied with scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA). The morphological results indicate the successful modification and the formation of MWCNTs/chitosan nanocomposites. The MWCNTs/chitosan nanocomposite was packed inside a glass column and used for the removal of copper, zinc, cadmium, and nickel ions from aqueous solution. The MWCNTs/chitosan nanocomposite showed a great efficiency for the removal of the target metal ions from the aqueous solution. The results suggested that this novel MWCNTs/chitosan nanocomposite could be used for different environmental applications.

  16. Coatable Li4 SnS4 Solid Electrolytes Prepared from Aqueous Solutions for All-Solid-State Lithium-Ion Batteries.

    Science.gov (United States)

    Choi, Young Eun; Park, Kern Ho; Kim, Dong Hyeon; Oh, Dae Yang; Kwak, Hi Ram; Lee, Young-Gi; Jung, Yoon Seok

    2017-06-22

    Bulk-type all-solid-state lithium-ion batteries (ASLBs) for large-scale energy-storage applications have emerged as a promising alternative to conventional lithium-ion batteries (LIBs) owing to their superior safety. However, the electrochemical performance of bulk-type ASLBs is critically limited by the low ionic conductivity of solid electrolytes (SEs) and poor ionic contact between the active materials and SEs. Herein, highly conductive (0.14 mS cm(-1) ) and dry-air-stable SEs (Li4 SnS4 ) are reported, which are prepared using a scalable aqueous-solution process. An active material (LiCoO2 ) coated by solidified Li4 SnS4 from aqueous solutions results in a significant improvement in the electrochemical performance of ASLBs. Side-effects of the exposure of LiCoO2 to aqueous solutions are minimized by using predissolved Li4 SnS4 solution. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Preparation of Al-doped ZnO films by aqueous solution process using a continuous circulation reactor

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Masao; Fukui, Hiroshi; Hirato, Tetsuji [Graduate School of Energy, Kyoto University, Yoshida-hommachi, Sakyo-ku, Kyoto 606-8501 (Japan)

    2012-05-15

    The fabrication of Al-doped ZnO films by an aqueous solution process using a continuous circulation reactor was studied. By heating ZnO-saturated ammonia solutions containing 2-10 mM Al(NO{sub 3}){sub 3} with pH 10.7 at 90 C under ambient pressure, polycrystalline ZnO films with Al content of 1-2 at.% were deposited. The carrier concentration of ZnO films increased with increasing Al content, indicating that Al was successfully incorporated into the ZnO crystals. The Al-doped ZnO films had carrier concentrations of 10{sup 19}-10{sup 20} cm{sup -3} and mobilities of 0.7-7 cm{sup 2}/V/s after annealing at 300 C in air. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Preparation and characterization of ammonium-functionalized silica nanoparticle as a new adsorbent to remove methyl orange from aqueous solution

    Science.gov (United States)

    Liu, Jinshui; Ma, Shi; Zang, Lingjie

    2013-01-01

    Quaternary ammonium polyethylenimine (PEI) was successfully modified to silica nanoparticle (QPEI/SiO2) as a new adsorbent to remove methyl orange from aqueous solution. The isotherm and kinetics of dye adsorption were studied, which showed that Langmuir isotherm fit the experimental results well. The maximum adsorption capacity of QPEI/SiO2 for methyl orange is 105.4 mg/g. The equilibrium time for methyl orange adsorption onto QPEI/SiO2 was as short as 10 min, indicating that the adsorbent has a strong affinity for methyl orange. The adsorption capacities of the methyl orange are slightly influenced by the pH in the range of 3.2-9.6. The QPEI/SiO2 adsorbent can be used in the wide pH range, which is different from other adsorbent. This may attribute to the quaternary ammonium carrying positive charges in acidic and basic solution.

  19. Adsorption Studies of Coconut Shell Carbons Prepared by KOH Activation for Removal of Lead(II From Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Chengwen Song

    2013-12-01

    Full Text Available Removal of Pb2+ from aqueous solutions using coconut shell carbons produced by KOH activation is performed in this paper. Morphology and pore structure characteristic of coconut shell carbons are analyzed by SEM and nitrogen adsorption techniques. Effects of adsorbent concentration, agitation time and initial ion concentration on the adsorption behavior are investigated, and adsorption isotherm and kinetics on coconut shell carbons are also studied. The results show that high weight ratio of KOH/sample is favorable to produce rich porous structure. The resultant coconut shell carbons with a high specific surface area of 1135 m2/g is obtained and demonstrates good adsorption potential on removal of Pb2+ from aqueous solutions. Adsorption data fit well with Freundlich and Halsey isotherms. The kinetic studies indicate that adsorption behavior can be described by pseudo-second-order kinetic model, which also follows external diffusion and intra-particle diffusion in the adsorption process.

  20. Preparation of ZnO Nanoparticles and Photocatalytic H2 Production Activity from Different Sacrificial Reagent Solutions

    Institute of Scientific and Technical Information of China (English)

    Tian-you Peng; Hong-jin Lv; Peng Zeng; Xiao-hu Zhang

    2011-01-01

    ZnO nanoparticles were synthesized via a direct precipitation method followed by a heterogeneous azeotropic distillation and calcination processes,and then characterized by X-ray power diffraction,scanning electron microscopy,transmission electron microscopy,and nitrogen adsorption-desorption measurement.The effects of Pt-loading amount,calcination temperature,and sacrificial reagents on the photocatalytic H2 evolution efficiency from the present ZnO suspension were investigated.The experimental results indicate that ZnO nanoparticles calcined at 400 ℃ exhibit the best photoactivity for the H2 production in comparison with the samples calcined at 300 and 500 ℃,and the photocatalytic H2 production efficiency from a methanol solution is much higher than that from a triethanolamine solution.It can be ascribed to the oxidization of methanol also contributes to the H2 production during the photochemical reaction process.Moreover,the photocatalytic mechanism for the H2 production from the present ZnO suspension system containing methanol solution is also discussed in detail.

  1. Study on Preparation and Characterization of Silver Nanoparticle Colloid Solution%纳米银的制备与表征

    Institute of Scientific and Technical Information of China (English)

    马守栋; 李明春; 叶勇; 曹恩惠; 赵丽艳

    2011-01-01

    目的 制备粒径小、性质稳定、抗菌活性强的纳米银.方法 化学合成法制备纳米银,以超滤法将反应体系中的杂质除去得高纯度的纳米银.以紫外分光光度计、透射电子显微镜、激光纳米粒度测定仪对其进行理化表征.结果 制备出的纳米银平均粒径为18.29nm,分布窄;表面带负电荷,平均表面Zeta电位为-36.5 mV;性质稳定,抗菌活性强.结论 实验结果表明,本方法可以制备出优良的纳米银.%OBJECTIVE To prepare silver nanoparticles with small particle diameter, good stability and high antimicrobial activity. METHODS The silver nanoparticles were prepared by chemical synthesis using silver nitrate,maltose and ammonia water as the reactants. The main physical properties of silver nanoparticles were characterized by UV spectrophotometer, transmission electron microscope and laser nanoparticle detecter. The bacteriostasis activity was determined by tube dilution method,using silver sulphadia-zine as the positive control. RESULTS The mean diameter of the silver nanoparticles was 18. 29 nm,and the Zeta potential was -36. 5 mV. The silver nanoparticles were steady and had higher bacteriostatic activity than silver sulphadiazine. CONCLUSION Hie chemical synthesis method can be used to prepare desired silver nanoparticles.

  2. Safety and efficacy of aspartame-based liquid versus sucrose-based liquids used for dilution in oral sodium phosphate solutions for colonoscopy preparations.

    Science.gov (United States)

    Chamberlain, Sherman M; Balart, J Carter; Sideridis, Kostas; Salek, Jefrey; Sridhar, Subbaramiah; Thompson, William O

    2007-11-01

    The aim of this study was to investigate whether an oral sodium phosphate solution (OSPS) mixed with aspartame-based clear liquids as the diluent would yield improved colon cleansing results compared to an OSPS mixed with sucrose-based liquids as the diluent. Fifty-one patients undergoing colonoscopy were prospectively randomized into two groups to receive different OSPS colonoscopy preparations, with sucrose-based or aspartame-based liquids used as diluents. The primary end point was the quality of the colonoscopy preparation and secondary end points were serum electrolytes before and after preparations. No significant difference in colonoscopy preparation quality was seen between the two OSPS diluent groups (Mantel-Haenzel chi (2) = 0.795, P = 0.484). There were no significant differences in mean electrolyte shifts of sodium, potassium, blood urea nitrogen (BUN), creatinine (Cr), or BUN/Cr ratios between the two groups. There was a statistically significant increase in serum phosphorous in the aspartame-based group compared to the sucrose-based diluent group (P = 0.021). In conclusion, there was no clinically detectable difference in colonoscopy preparation quality between the two OSPS diluent groups. This study suggests that passive fluid transport by aquaporins may well be the major mediator of fluid shifts in the study subjects. This result suggests the potential importance of aquaporins and minimizes the importance of sodium glucose cotransporter SGLT1 in fluid and electrolyte transport in the human gastrointestinal tract. Aspartame or its constituent amino acids may enhance phosphate absorption across the human small intestine.

  3. Studies on the Preparation of Opuntia dillenii Haw.Polysaccharides Oral Solution%仙人掌多糖口服液的研制

    Institute of Scientific and Technical Information of China (English)

    赵龙岩; 杨小舟; 程杰; 袁清霞; 曾富华

    2011-01-01

    To prepare the ODPs oral solution and to provide a reference for the industrialization of ODPs.The key components and the preparation process of the ODPs oral solution were determined by orthogonal test.The strong light,high temperature and Rogers nonisothermal accelerative test were employed to study the stability of the ODPs oral solution.The optimal sterilization conditions using a microwave were 700 W(power),9 min(time);the optimal prescription was 10 g·L-1 of ODPs,0.64 g·L-1 of the stevioside,0.025 6 g·L-1 of the mixed parabens.the main indexes meet the statutory quality standards of the oral solution.The illumination did not affect the quality of ODPs oral solution.The expiry of the ODPs oral solution tested by Rogers method was 4.5 h,so it should be stored under a low temperature condition.%以ODPs为原料,采用正交试验确定口服液中关键成分的配比及制备工艺条件,并采用强光照射、高温、Rogers加温加速试验对口服液的稳定性进行研究.得出ODPs口服液的最佳灭菌条件为灭菌功率700W、灭菌时间9min;最佳处方(以1L口服液计)为ODPs 10g,甜菊糖0.64g,尼泊金混合酯0.025 6g,各项主要质量指标符合口服液制剂法定质量标准.ODPs口服液对光照不敏感,无需避光保存;高温试验、Rogers法测得ODPs口服液的t0.9为5.4h,说明在高温条件下,其稳定性较差,应低温储存.

  4. Preparation of CuAlO2 Thin Films by Sol-Gel Method Using Nitrate Solution Dip-Coating

    Directory of Open Access Journals (Sweden)

    Ehara Takashi

    2016-01-01

    Full Text Available CuAlO2 thin films are prepared by sol-gel dip-coating followed by annealing in nitrogen atmosphere using copper nitrate and aluminum nitrate as metal source materials. X-ray diffraction (XRD patterns show (003, (006 and (009 oriented peaks of CuAlO2 at annealing temperature of 800 – 1000°C. This result indicates that the CuAlO2 films prepared in the present work are c-axis oriented. XRD peak intensity increase with annealing temperature and becomes maximum at 850°C. The CuAlO2 XRD peak decreased at annealing temperature of 900°C with appearance of a peak of CuO, and then increased again with annealing temperature until 1000 °C. The films have bandgap of 3.4 eV at annealing temperature of 850°C in which the transparency becomes the highest. At the annealing temperature of 850°C, scanning electron microscope (SEM observation reveals that the films are consist of amorphous fraction and microcrystalline CuAlO2 fraction.

  5. Microstructural features of the La{sub 1−x}Ca{sub x}FeO{sub 3−δ} solid solutions prepared via Pechini route

    Energy Technology Data Exchange (ETDEWEB)

    Gerasimov, E.Yu., E-mail: gerasimov@catalysis.ru [Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Pr. Acad. Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090 (Russian Federation); Isupova, L.A. [Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Pr. Acad. Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Tsybulya, S.V. [Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Pr. Acad. Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090 (Russian Federation)

    2015-10-15

    Highlights: • La{sub 1−x}Ca{sub x}FeO {sub (3−δ)} (0 ≤ x ≤ 0.7) perovskite were prepared by Pechini method. • Planar defects in direction (1 0 1) were observed in the perovskite surface. • α-Fe{sub 2}O{sub 3} particles (1–10 nm) on the surface of perovskite were revealed. • Amount of α-Fe{sub 2}O{sub 3} particles on the perovskite surface grew with rising x values. - Abstract: Solid solutions with La{sub 1−x}Ca{sub x}FeO{sub 3−δ} (0 ≤ x ≤ 0.7) perovskite-like structure prepared via Pechini route have been investigated by using high resolution transmission electron microscopy and X-ray diffraction. Extended planar defects lying in (1 0 1) crystallographic planes and α-Fe{sub 2}O{sub 3} nanoparticles on the surface of perovskite microcrystals are characteristic of the samples under investigation. It was found that testing of the samples in catalytic deep CH{sub 4} oxidation process results in partial destruction of solid solutions with formation of planar defects in the bulk and α-Fe{sub 2}O{sub 3} particles on the surface.

  6. Aqueous Chemical Solution Deposition of Novel, Thick and Dense Lattice-Matched Single Buffer Layers Suitable for YBCO Coated Conductors: Preparation and Characterization

    Directory of Open Access Journals (Sweden)

    Isabel van Driessche

    2012-09-01

    Full Text Available In this work we present the preparation and characterization of cerium doped lanthanum zirconate (LCZO films and non-stoichiometric lanthanum zirconate (LZO buffer layers on metallic Ni-5% W substrates using chemical solution deposition (CSD, starting from aqueous precursor solutions. La2Zr2O7 films doped with varying percentages of Ce at constant La concentration (La0.5CexZr1−xOy were prepared as well as non-stoichiometric La0.5+xZr0.5−xOy buffer layers with different percentages of La and Zr ratios. The variation in the composition of these thin films enables the creation of novel buffer layers with tailored lattice parameters. This leads to different lattice mismatches with the YBa2Cu3O7−x (YBCO superconducting layer on top and with the buffer layers or substrate underneath. This possibility of minimized lattice mismatch should allow the use of one single buffer layer instead of the current complicated buffer architectures such as Ni-(5% W/LZO/LZO/CeO2. Here, single, crack-free LCZO and non-stoichiometric LZO layers with thicknesses of up to 140 nm could be obtained in one single CSD step. The crystallinity and microstructure of these layers were studied by XRD, and SEM and the effective buffer layer action was studied using XPS depth profiling.

  7. Dynamic Solution Injection: a new method for preparing pptv–ppbv standard atmospheres of volatile organic compounds

    Directory of Open Access Journals (Sweden)

    L. Abrell

    2010-11-01

    Full Text Available Proton Transfer Reaction-Mass Spectrometry (PTR-MS and thermal desorption Gas Chromatography-Mass Spectrometry (GC-MS allow for absolute quantification of a wide range of atmospheric volatile organic compounds (VOCs with concentrations in the ppbv to pptv range. Although often neglected, routine calibration is necessary for accurate quantification of VOCs by PTR-MS and GC-MS. Several gas calibration methods currently exist, including compressed gas cylinders, permeation tubes, diffusion tubes, and liquid injection. While each method has its advantages and limitations, no single technique has emerged that is capable of dynamically generating known concentrations of complex mixtures of VOCs over a large concentration range (ppbv to pptv and is technically simple, field portable, and affordable. We present the development of a new VOC calibration technique based on liquid injection with these features termed Dynamic Solution Injection (DSI. This method consists of injecting VOCs (0.1–0.5 mM dissolved in cyclohexane (PTR-MS or methanol (GC-MS into a 1.0 slpm flow of purified dilution gas in an unheated 25 ml glass vial. Upon changes in the injection flow rate (0.5–4.0 μl min−1, new VOC concentrations are reached within seconds to minutes, depending on the compound, with a liquid injection flow rate accuracy and precision of better than 7% and 4% respectively. We demonstrate the utility of the DSI technique by calibrating a PTR-MS to seven different cyclohexane solutions containing a total of 34 different biogenic compounds including volatile isoprenoids, oxygenated VOCs, fatty acid oxidation products, aromatics, and dimethyl sulfide. We conclude that because of its small size, low cost, and simplicity, the Dynamic Solution Injection method will be of great use to both laboratory and field VOC studies.

  8. ENTIRELY AQUEOUS SOLUTION-GEL ROUTE FOR THE PREPARATION OF ZIRCONIUM CARBIDE, HAFNIUM CARBIDE AND THEIR TERNARY CARBIDE POWDERS

    Directory of Open Access Journals (Sweden)

    Zhang Changrui

    2016-07-01

    Full Text Available An entirely aqueous solution-gel route has been developed for the synthesis of zirconium carbide, hafnium carbide and their ternary carbide powders. Zirconium oxychloride (ZrOCl₂.8H₂O, malic acid (MA and ethylene glycol (EG were dissolved in water to form the aqueous zirconium carbide precursor. Afterwards, this aqueous precursor was gelled and transformed into zirconium carbide at a relatively low temperature (1200 °C for achieving an intimate mixing of the intermediate products. Hafnium and the ternary carbide powders were also synthesized via the same aqueous route. All the zirconium, hafnium and ternary carbide powders exhibited a particle size of ∼100 nm.

  9. Effect of preparation and test variables on the dissolution kinetics in saline solutions of rapidly solidified and standard magnesium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, D.S. [School of Materials, Univ. of Sheffield (United Kingdom); Edyvean, R.G.J. [School of Materials, Univ. of Sheffield (United Kingdom); Jones, H. [School of Materials, Univ. of Sheffield (United Kingdom); Sellars, C.M. [School of Materials, Univ. of Sheffield (United Kingdom)

    1992-12-31

    Renewed interest in the factors that determine the corrosion characteristics of magnesium alloys has been stimulated of late by the opportunity to provide high strength, corrosion resistant magnesium alloys as ultralight castings and wrought products for automobile and aerospace applications. The present contribution forms part of continuing work at Sheffield to develop improved magnesium alloys by rapid solidification routes. It was motivated by the need to assess the usefulness of dissolution rate, measured during short-term immersion in 3% NaCl solution of rapidly solidified samples, such as splats or ribbons, as a screening parameter to select alloys for full evaluation in scale-up quantities. (orig.)

  10. Reclamation of zinc-contaminated soil using a dissolved organic carbon solution prepared using liquid fertilizer from food-waste composting

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Po-Neng [Experimental Forest, National Taiwan University, Chushan, Nantou County, 55750, Taiwan (China); Tong, Ou-Yang [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Chiou, Chyow-San; Lin, Yu-An [Department of Environmental Engineering, National Ilan University, Ilan 26047, Taiwan (China); Wang, Ming-Kuang [Department of Animal Science, National Ilan University, Ilan 26047, Taiwan (China); Liu, Cheng-Chung, E-mail: ccliu@niu.edu.tw [Department of Agricultural Chemistry, National Taiwan University, Taipei 10617, Taiwan (China)

    2016-01-15

    Highlights: • Nitrogen, phosphorus, and potassium contents in soil are substantially increased after the DOC washing. • The removal of Zn is dominated by proton replacement at pH 2.0, rather than by complexation with DOC. • The removal of Zn is dominated by DOC complexation between pH 3.0 and pH 5.0. - Abstract: A liquid fertilizer obtained through food-waste composting can be used for the preparation of a dissolved organic carbon (DOC) solution. In this study, we used the DOC solutions for the remediation of a Zn-contaminated soil (with Zn concentrations up to 992 and 757 mg kg{sup −1} in topsoil and subsoil, respectively). We then determined the factors that affect Zn removal, such as pH, initial concentration of DOC solution, and washing frequency. Measurements using a Fourier Transform infrared spectrometer (FT-IR) revealed that carboxyl and amide were the major functional groups in the DOC solution obtained from the liquid fertilizer. Two soil washes using 1,500 mg L{sup −1} DOC solution with a of pH 2.0 at 25 °C removed about 43% and 21% of the initial Zn from the topsoil and subsoil, respectively. Following this treatment, the pH of the soil declined from 5.4 to 4.1; organic matter content slightly increased from 6.2 to 6.5%; available ammonium (NH{sub 4}{sup +}-N) content increased to 2.4 times the original level; and in the topsoil, the available phosphorus content and the exchangeable potassium content increased by 1.65 and 2.53 times their initial levels, respectively.

  11. High performance GdBa{sub 2}Cu{sub 3}O{sub 7-z} film preparation by non-fluorine chemical solution deposition approach

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.T.; Pu, M.H.; Wang, W.W. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhang, H. [Department of Physics, Peking University, Beijing 100871 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)] [Superconductivity Research Group, School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia); Zhao, Y., E-mail: yzhao@swjtu.edu.cn [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)] [Superconductivity Research Group, School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia)

    2011-11-15

    Biaxially textured GdBa{sub 2}Cu{sub 3}O{sub 7}-z films with Tc above 93 K have been prepared on (0 0 l) by non-fluorine CSD approach. Nanoparticles with homogeneous distribution are introduced into the GdBCO films as effective pinning centers. A high Jc (77 K, 0 T) of 2.28 MA/cm{sup 2} with slow decreasing Jc-B behavior is observed in the films. Biaxially textured GdBa{sub 2}Cu{sub 3}O{sub 7-z} (GdBCO) films with T{sub c} above 93 K have been prepared on (0 0 l) LaAlO{sub 3} substrate by self-developed non-fluorine polymer-assisted chemical solution deposition (PA-CSD) approach. The GdBCO films show smooth and crack-free morphology. Many nanoscale particles with homogeneous distribution are observed in the GdBCO films, which have not been observed yet in the YBa{sub 2}Cu{sub 3}O{sub 7-z} (YBCO) films prepared by the same processing technique. Besides a high J{sub c} (77 K, 0 T) of 2.28 MA/cm{sup 2}, the optimized GdBCO films show a better J{sub c}-B behavior and an improved high-field J{sub c}, compared to the YBCO films.

  12. Preparation and characterization of zirconia-loaded lignocellulosic butanol residue as a biosorbent for phosphate removal from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Zong, Enmin [Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000 (China); Liu, Xiaohuan, E-mail: liuxiaohuancaf@163.com [School of Engineering, National Engineering and Technology Research Center of Wood-Based Resources Comprehensive Utilization, and Key Laboratory of Wood Science and Technology of Zhejiang Province, Zhejiang Agriculture and Forestry University, Hangzhou, Lin’an 311300 (China); Jiang, Jinhua [Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000 (China); Fu, Shenyuan [School of Engineering, National Engineering and Technology Research Center of Wood-Based Resources Comprehensive Utilization, and Key Laboratory of Wood Science and Technology of Zhejiang Province, Zhejiang Agriculture and Forestry University, Hangzhou, Lin’an 311300 (China); Chu, Fuxiang [Institute of Chemical Industry of Forestry Products, CAF, Nanjing 210037 (China)

    2016-11-30

    Highlights: • LBR-Zr was evaluated as a novel biosorbent for phosphate removal. • Effects of process factors on phosphate adsorption were studied in detail. • LBR-Zr showed markedly enhanced phosphate adsorption compared to LBR. • The underlying mechanism for phosphate adsorption of LBR-Zr was fully investigated. - Abstract: Zirconium(IV) loaded lignocellulosic butanol residue (LBR-Zr) used for the adsorption of phosphate (P) ions from aqueous solution was synthesized and evaluated. The adsorption isotherms were fitted well with the Freundlich and Temkin modes. Thermodynamic analyses indicated that phosphate adsorption on the LBR-Zr increased with increasing temperature from 298 to 338 K. The kinetic datas were described better by the pseudo-second-order adsorption kinetic rate model. Increasing pH suppressed phosphate adsorption. Coexisting anions study exhibited that the incorporation of CO{sub 3}{sup 2−} anion had the largest influence on the phosphate adsorption capacity. The mechanism of adsorption process on LBR-Zr was analyzed by FTIR (Fourier transform infrared spectroscopy), scanning electron microscope (SEM) with an EDX (energy dispersive X-ray) and X-ray photoelectron spectroscopy (XPS) technologies, respectively. The above results confirmed that surface hydroxyl groups on biosorbent LBR-Zr were replaced by phosphate. The LBR-Zr with good specific affinity towards phosphate was a promising biosorbent for phosphate removal from aqueous solution. The research would be beneficial for developing a promising, eco-friendly phosphate biosorbent from plentiful lignocellulosic butanol residue.

  13. Inverted organic solar cells with ZnO nanowalls prepared using wet chemical etching in a KOH solution.

    Science.gov (United States)

    Shin, Kyung-Sik; Park, Hye-Jeong; Kumar, Brijesh; Kim, Kwon-Ho; Kim, Sang-Hyeob; Kim, Sang-Woo

    2012-02-01

    We report on the photovoltaic (PV) performances of inverted organic solar cells (IOSCs) that were fabricated from PCBM:P3HT polymer with a ZnO thin film and ZnO nanowalls as electron transport and hole block layers. ZnO thin film on ITO/glass substrate was deposited using a simply aqueous solution route. ZnO nanowall structures were obtained via wet chemical etching of ZnO thin films in a KOH solution. The power conversion efficiency (PCE) of the IOSC with ZnO nanowalls was significantly improved by 44% from 1.254% to 1.811% compared to that of the IOSC with ZnO thin film. The short circuit current in IOSCs fabricated with the ZnO nanowalls was increased mainly due to the increase in the charge transport interface area, as a result of enhancement in the PCE. This work suggests a method for fabricating efficient PV devices with a larger charge transport area for future prospects.

  14. Electrically conductive nanostructured silver doped zinc oxide (Ag:ZnO) prepared by solution-immersion technique

    Science.gov (United States)

    Afaah, A. N.; Asib, N. A. M.; Aadila, A.; Mohamed, R.; Rusop, M.; Khusaimi, Z.

    2016-07-01

    p-type ZnO films have been fabricated on ZnO-seeded glass substrate, using AgNO3 as a source of silver dopant by facile solution-immersion. Cleaned glass substrate were seeded with ZnO by mist-atomisation, and next the seeded substrates were immersed in Ag:ZnO solution. The effects of Ag doping concentration on the Ag-doped ZnO have been investigated. The substrates were immersed in different concentrations of Ag dopant with variation of 0, 1, 3, 5 and 7 at. %. The surface morphology of the films was characterized by field emission scanning electron microscope (FESEM). In order to investigate the electrical properties, the films were characterized by Current-Voltage (I-V) measurement. FESEM micrographs showed uniform distribution of nanostructured ZnO and Ag:ZnO. Besides, the electrical properties of Ag-doped ZnO were also dependent on the doping concentration. The I-V measurement result indicated the electrical properties of 1 at. % Ag:ZnO thin film owned highest electrical conductivity.

  15. Supercapacitor performances of activated carbon fiber webs prepared by electrospinning of PMDA-ODA poly(amic acid) solutions

    Energy Technology Data Exchange (ETDEWEB)

    Chan Kim; Lee, Wan Jin; Yang, Kep Seung [Chonnam National Univ., Gwangju (Korea). Faculty of Applied Chemical Engineering; Choi, Yeong Og [Korea Inst. of Industrial Technology, ChonAn (Korea). Technical Textile Research Team

    2004-11-30

    The poly(amic acid) (PAA) solution was successfully electrospun at voltages between 13 and 15 kV, forming yellow webs of fibers with diameters of 2-3 {mu}m. The PAA web was then imidized with yield of about 81%. The imidized webs were carbonized in the temperature range from 700 to 1000 {sup o}C under a nitrogen atmosphere with yields greater than or equal to 53%. The flexible carbonized fiber web with the amorphous structure and the relatively high electrical conductivity of 2.5 S/cm at 1000 {sup o}C appears to be a good candidate material for the electrode of electrical double layer capacitors (EDLCs). The carbonized webs were activated under steam in the temperature range of 650-850 {sup o}C resulting surface specific surface area of 940-2100 m{sup 2}/g. The activated carbonized webs were tested electrochemically for the performances as electrodes of EDLC in 30 wt.% KOH aqueous solution. The specific capacitance was 175 F/g even at a high current density of 1000 mA/g. (Author)

  16. Nitrilotriacetic acid functionalized Adansonia digitata biosorbent: Preparation, characterization and sorption of Pb (II and Cu (II pollutants from aqueous solution

    Directory of Open Access Journals (Sweden)

    Adewale Adewuyi

    2016-11-01

    Full Text Available Nitrilotriacetic acid functionalized Adansonia digitata (NFAD biosorbent has been synthesized using a simple and novel method. NFAD was characterized by X-ray Diffraction analysis technique (XRD, Scanning Electron Microscopy (SEM, Brunauer-Emmett-Teller (BET surface area analyzer, Fourier Transform Infrared spectrometer (FTIR, particle size dispersion, zeta potential, elemental analysis (CHNS/O analyzer, thermogravimetric analysis (TGA, differential thermal analysis (DTA, derivative thermogravimetric analysis (DTG and energy dispersive spectroscopy (EDS. The ability of NFAD as biosorbent was evaluated for the removal of Pb (II and Cu (II ions from aqueous solutions. The particle distribution of NFAD was found to be monomodal while SEM revealed the surface to be heterogeneous. The adsorption capacity of NFAD toward Pb (II ions was 54.417 mg/g while that of Cu (II ions was found to be 9.349 mg/g. The adsorption of these metals was found to be monolayer, second-order-kinetic, and controlled by both intra-particle diffusion and liquid film diffusion. The results of this study were compared better than some reported biosorbents in the literature. The current study has revealed NFAD to be an effective biosorbent for the removal of Pb (II and Cu (II from aqueous solution.

  17. Nitrilotriacetic acid functionalized Adansonia digitata biosorbent: Preparation, characterization and sorption of Pb (II) and Cu (II) pollutants from aqueous solution.

    Science.gov (United States)

    Adewuyi, Adewale; Pereira, Fabiano Vargas

    2016-11-01

    Nitrilotriacetic acid functionalized Adansonia digitata (NFAD) biosorbent has been synthesized using a simple and novel method. NFAD was characterized by X-ray Diffraction analysis technique (XRD), Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier Transform Infrared spectrometer (FTIR), particle size dispersion, zeta potential, elemental analysis (CHNS/O analyzer), thermogravimetric analysis (TGA), differential thermal analysis (DTA), derivative thermogravimetric analysis (DTG) and energy dispersive spectroscopy (EDS). The ability of NFAD as biosorbent was evaluated for the removal of Pb (II) and Cu (II) ions from aqueous solutions. The particle distribution of NFAD was found to be monomodal while SEM revealed the surface to be heterogeneous. The adsorption capacity of NFAD toward Pb (II) ions was 54.417 mg/g while that of Cu (II) ions was found to be 9.349 mg/g. The adsorption of these metals was found to be monolayer, second-order-kinetic, and controlled by both intra-particle diffusion and liquid film diffusion. The results of this study were compared better than some reported biosorbents in the literature. The current study has revealed NFAD to be an effective biosorbent for the removal of Pb (II) and Cu (II) from aqueous solution.

  18. Preparation, characterization and mechanical properties of microarc oxidation coating formed on titanium in Al(OH)3 colloidal solution

    Science.gov (United States)

    Li, Y.; Yao, B.; Long, B. Y.; Tian, H. W.; Wang, B.

    2012-04-01

    A ceramic coating with thickness of 20-70 μm was grown on titanium plate in Al(OH)3 colloidal solution by microarc oxidation (MAO) in constant current mode. It is found that the as-grown coating consists of rutile TiO2 phase together with a thin layer of Ai2TiO5 phase near the surface of the coating. After removing the Ai2TiO5 layer by polishing, a single phase of rutile TiO2 coating is achieved, which is different from results reported previously, where the coating is usually composed of two phases of rutile and anatase TiO2. It is suggested that the formation of the coating with single phase of rutile TiO2 is related to the existence of Al(OH)3 in the solution. The growth rate of the coating increases with increasing current density in the range of 17-23 A/dm2, but it increases little in the range of 23-30 A/dm2. The rutile TiO2 coating looks compactness and solidity in the coating grown in the density range of 17-23 A/dm2 but looseness and insubstantiality in the range of 23-30 A/dm2. The hardness and elastic modulus of the rutile TiO2 decreases with the density increasing. The mechanism of formation of the coating is discussed in the present work.

  19. Preparation and characterization of zirconia-loaded lignocellulosic butanol residue as a biosorbent for phosphate removal from aqueous solution

    Science.gov (United States)

    Zong, Enmin; Liu, Xiaohuan; Jiang, Jinhua; Fu, Shenyuan; Chu, Fuxiang

    2016-11-01

    Zirconium(IV) loaded lignocellulosic butanol residue (LBR-Zr) used for the adsorption of phosphate (P) ions from aqueous solution was synthesized and evaluated. The adsorption isotherms were fitted well with the Freundlich and Temkin modes. Thermodynamic analyses indicated that phosphate adsorption on the LBR-Zr increased with increasing temperature from 298 to 338 K. The kinetic datas were described better by the pseudo-second-order adsorption kinetic rate model. Increasing pH suppressed phosphate adsorption. Coexisting anions study exhibited that the incorporation of CO32- anion had the largest influence on the phosphate adsorption capacity. The mechanism of adsorption process on LBR-Zr was analyzed by FTIR (Fourier transform infrared spectroscopy), scanning electron microscope (SEM) with an EDX (energy dispersive X-ray) and X-ray photoelectron spectroscopy (XPS) technologies, respectively. The above results confirmed that surface hydroxyl groups on biosorbent LBR-Zr were replaced by phosphate. The LBR-Zr with good specific affinity towards phosphate was a promising biosorbent for phosphate removal from aqueous solution. The research would be beneficial for developing a promising, eco-friendly phosphate biosorbent from plentiful lignocellulosic butanol residue.

  20. Preparation and application of amino functionalized mesoporous nanofiber membrane via electrospinning for adsorption of Cr3+ from aqueous solution

    Institute of Scientific and Technical Information of China (English)

    Ahmed A.Taha; Junlian Qiao; Fengting Li; Bingru Zhang

    2012-01-01

    Novel amino (-NH2) functionalized mesoporous polyvinyl pyrrolidone (PVP)/SiO2 composite nanofiber membranes were fabricated by a one-step electrospinning method using poly (vinyl alcohol) and tetraethyl orthosilicate (TEOS) mixed with cationic surfactant,cetyltrimethyl ammonium bromide (CTAB) as the structure directing agent.Ureidopropyltriethoxysilane was used for functionalization of the internal pore surfaces.The membranes were characterized by scanning electron microscopy (SEM),high-resolution transmission electron microscopy (HRTEM) images,X-ray diffraction (XRD),Fourier-transform infrared spectroscopy (FT-IR),element analyzer and N2 adsorption-desorption isotherms.The nanofiber diameters,average pore diameters and surface areas were 100-700 nm,2.86 nm and 873.62 m2/g,respectively.These mesoporous membranes functionalized with -NH2 groups exhibited very high adsorptions properties based on the adsorption of Cr3+ from an aqueous solution.Equilibrium adsorption was achieved after approximately 20 min and more than 97% of chromium ions in the solution were removed.The membrane could be regenerated through acidification.

  1. Porous hydrogel of wool keratin prepared by a novel method: An extraction with guanidine/2-mercaptoethanol solution followed by a dialysis

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, Yuki; Takagi, Yusuke; Mori, Hideki; Hara, Masayuki, E-mail: hara@b.s.osakafu-u.ac.jp

    2014-09-01

    In this study, we show a novel simple method to prepare a sponge-like porous keratin hydrogel through the extraction of wool keratin in a solution containing guanidine hydrochloride and 2-mercaptoethanol followed by dialysis for both aggregation of keratin and recrosslink. The gel had a highly porous structure and a fast-swelling property in rehydration after freeze-drying. It had also high mechanical strength both in the tensile test and the measurement of dynamic viscoelasticity. Three types of animal cells, PC12 cells, HOS cells and murine embryonic fibroblasts, well attached and grew on the surface of the porous hydrogel. - Graphical abstract: We show a novel simple method to prepare a sponge-like porous keratin hydrogel (A, B) through the extraction of wool keratin in a solution containing guanidine hydrochloride and 2-mercaptoethanol followed by dialysis for both aggregation of keratin and recrosslink. The gel had a highly porous structure (B) and a fast-swelling property in rehydration after freeze-drying. It had also high mechanical strength both in the tensile test (C) and the measurement of dynamic viscoelasticity (D). Three types of animal cells, PC12 cells (E), HOS cells (F) and murine embryonic fibroblasts (MEFs) (G), well attached and grew on the surface of the porous hydrogel. - Highlights: • We prepared a sponge-like porous keratin hydrogel by a novel method. • We used guanidine with 2-mercaptoethanol to extract keratin from wool fiber. • Extracted keratin was recrosslinked to form a porous keratin hydrogel in dialysis. • The keratin hydrogel had a high mechanical strength. • Three types of cells attached on the keratin hydrogel proliferated well.

  2. Use of alkali metal salts to prepare high purity single-walled carbon nanotube solutions and thin films

    Science.gov (United States)

    Ashour, Rakan F.

    Single-walled carbon nanotubes (SWCNTs) display interesting electronic and optical properties desired for many advanced thin film applications, such as transparent conductive electrodes or thin-film transistors. Large-scale production of SWCNTs generally results in polydispersed mixtures of nanotube structures. Since SWCNT electronic character (conducting or semiconducting nature) depends on the nanotube structure, application performance is being held back by this inability to discretely control SWCNT synthesis. Although a number of post-production techniques are able to separate SWCNTs based on electronic character, diameter, or chirality, most still suffer from the disadvantage of high costs of materials, equipment, or labor intensity to be relevant for large-scale production. On the other hand, chromatographic separation has emerged as a method that is compatible with large scale separation of metallic and semiconducting SWCNTs. In this work, SWCNTs, in an aqueous surfactant suspension of sodium dodecyl sulfate (SDS), are separated by their electronic character using a gel chromatography process. Metallic SWCNTs (m-SWCNTs) are collected as initial fractions since they show minimum interaction with the gel medium, whereas, semiconducting SWCNTs (sc- SWCNTs) remain adsorbed to the gel. The process of sc-SWCNT retention in the gel is found to be driven by the packing density of SDS around the SWCNTs. Through a series of separation experiments, it is shown that sc-SWCNTs can be eluted from the gel simply by disturbing the configuration of the SDS/SWCNT micellar structure. This is achieved by either introducing a solution containing a co-surfactant, such as sodium cholate (SC), or solutions of alkali metal ionic salts. Analysis of SWCNT suspensions by optical absorption provides insights into the effect of changing the metal ion (M+ = Li+, Na+, and K+) in the eluting solution. Salts with smaller metal ions (e.g. Li+) require higher concentrations to achieve

  3. Preparation of a porous clay heterostructure and study of its adsorption capacity of phenol and chlorinated phenols from aqueous solutions.

    Science.gov (United States)

    Arellano-Cárdenas, Sofía; Gallardo-Velázquez, Tzayhrí; Osorio-Revilla, Guillermo; López-Cortez, Ma del Socorro

    2008-01-01

    A porous clay heterostructure (PCH) from a Mexican clay was prepared and characterized, and its aqueous phenol and dichlorophenols (DCPs) adsorption capacities were studied using a batch equilibrium technique. The PCH displayed a surface area of 305.5 m2/g, 37.2 A average porous diameter, and a basal space of 23.2 A. The adsorption capacity shown by the PCH for both phenol and DCPs from water (14.5 mg/g for phenol; 48.7 mg/g for 3,4-DCP; and 45.5 mg/g for 2,5-DCP) suggests that the PCH has both hydrophobic and hydrophilic characteristics, as a result of the presence of silanol and siloxane groups formed during the pillaring and calcination of the PCH. The values of maximal adsorption capacity for dichlorophenols were higher than those reported for aluminum pillared clays and some inorgano-organo clays and comparable with some ionic exchange resins.

  4. Dynamic Solution Injection: a new method for preparing pptv-ppbv standard atmospheres of volatile organic compounds

    Directory of Open Access Journals (Sweden)

    K. J. Jardine

    2010-07-01

    Full Text Available Proton Transfer Reaction-Mass Spectrometry (PTR-MS and thermal desorption Gas Chromatography-Mass Spectrometry (GC-MS allow for absolute quantification of a wide range of atmospheric volatile organic compounds (VOCs with concentrations in the ppbv to pptv range. Although often neglected, routine calibration is necessary for accurate quantification of VOCs by PTR-MS and GC-MS. Several gas calibration methods currently exist, including compressed gas cylinders, permeation tubes, diffusion tubes, and liquid injection. While each method has its advantages and limitations, no single technique has emerged that is capable of dynamically generating accurate concentrations of complex mixtures of VOCs over a large concentration range (ppbv to pptv, is technically simple and field portable, and affordable. We present the development of a new VOC calibration technique based on liquid injection with these features termed Dynamic Solution Injection (DSI. This method consists of injecting VOCs (0.1–0.5 mM dissolved in cyclohexane (PTR-MS or methanol (GC-MS into a 1.0 slpm flow of purified dilution gas in an unheated 25 mL glass vial. Upon changes in the injection flow rate (0.5–4.0 μL min−1, new VOC concentrations are reached within seconds to minutes, depending on the compound, with a liquid injection flow rate accuracy and precision of better than 7% and 4%, respectively. We demonstrate the utility of the DSI technique by calibrating a PTR-MS to seven different cyclohexane solutions containing a total of 34 different biogenic compounds including volatile isoprenoids, oxygenated VOCs, fatty acid oxidation products, aromatics, and dimethyl sulfide. In order to validate the new DSI method, a GC-MS and PTR-MS calibration intercomparison with VOC standards generated by dynamic dilution of NIST traceable permeation tubes (α-pinene, acetone, and ethanol and a compressed gas cylinder (acetaldehyde was made. The results revealed that while

  5. Preparation and characterization of porous granular ceramic containing dispersed aluminum and iron oxides as adsorbents for fluoride removal from aqueous solution.

    Science.gov (United States)

    Chen, Nan; Zhang, Zhenya; Feng, Chuanping; Zhu, Dirui; Yang, Yingnan; Sugiura, Norio

    2011-02-15

    Porous granular ceramic adsorbents containing dispersed aluminum and iron oxides were synthesized by impregnating with salt solutions followed by precipitation at 600°C. In the present work detailed studies were carried out to investigate the effect of contact time, adsorbent dose, initial solution pH and co-existing anions. Characterization studies on the adsorbent by SEM, XRD, EDS, and BET analysis were carried out to clarify the adsorption mechanism. The adsorbents were sphere in shape, 2-3mm in particle size, highly porous and showed specific surface area of 50.69 sq m/g. The fluoride adsorption capacity of prepared adsorbent was 1.79 mg/g, and the maximum fluoride removal was obtained at pH 6. Both the Langmuir and Freundlich isotherm models were found to represent the measured adsorption data well. The experimental data were well explained with pseudo-second-order kinetic model. Results from this study demonstrated potential utility of Al/Fe dispersed in porous granular ceramics that could be developed into a viable technology for fluoride removal from aqueous solution. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Efficacy and local tolerability of povidone iodine and octenidine hydrochloride solution for the antiseptic preparation of the orificium urethrae.

    Science.gov (United States)

    Rudolph, P; Fritze, F; Reimer, K; Klebingat, K J; Kramer, A

    1999-01-01

    In a randomized clinical study, 61 hospitalized men were examined to test the local tolerability and antimicrobial efficacy of antiseptic treatment of the genitals with povidone iodine versus octenidine hydrochloride solution. Antibacterial efficacy was established by comparing the total aerobic bacterial colony count from standardized swabs from the orificium urethrae externum before, immediately after, and 30 and 60 min after antisepsis. Tolerability was assessed by dermatoscopy, applying a scale to rate the criteria of reddening, erosions and microbleeding. pH-value was taken and the nitracin yellow test carried out at several intervals. Patients assessed sensations (itching, burning, warmth, cold tension) in visual analogue scales. The test for equivalence in efficacy of both antiseptic agents produced no significant result (P = 0.3). The sum score of tolerability produced a better result for povidone iodine. In addition, the drop in the pH value after observed antisepsis with povidone iodine provides an additional protective mechanism against bacterial colonization.

  7. Synthesis of SnO2 nanorods from aqueous solution: The effect of preparation conditions on the formed patterns

    Institute of Scientific and Technical Information of China (English)

    Xin Wen Huang; Zong Jian Liu; Yi Fan Zheng; Qiu Lin Nie

    2010-01-01

    SnO2 nanorods were deposited on the Si substrates in an aqueous solution containing both SnCl4 and CO(NH2)2. It is found that different self-assembled patterns of SnO2 nanorods can be obtained by changing the deposition conditions such as the molar ratio of CO(NH2)2 to SnCl4 and the pretreatment of the substrate. Scattered SnO2 nanorods, for example, can be changed into flower-like patterns when the molar ratio of CO(NH2)2 to SnCl4 is raised, and well-aligned nanorod arrays can be formed when the pretreatment of the snbstrate is changed. In addition, some interesting patterns, e.g. Tree-like patterns, can also be observed.

  8. The Effect of Toluene Solution on the Hydrogen Absorption of the Mg-Ti Alloy Prepared by Synthetic Alloying

    Directory of Open Access Journals (Sweden)

    H. Suwarno

    2009-07-01

    Full Text Available The synthesis and characterization of the Mg–Ti alloy have been carried out through a mechanical alloying technique under toluene solution. The Mg and Ti powders are milled for 10, 20, and 30 h in a high energy ball mill. The milled alloys are then hydrided at a temperature of 300 oC in order to investigate the possibility used for hydrogen storage materials. The refinement analyses of the x-ray diffraction patterns show that mechanical alloying of the Mg–Ti powders under toluene solution results in the formation of the TiH2 and Mg2Ti phases. Quantitative analyses indicate that the mass fractions of the TiH2 and Mg2Ti phases are 62.90 % and 30.60 %, while the value for Mg and Ti amount to 2.6 wt% and 1.25 wt%. On hydriding at a temperature of 300 oC, the milled powders are transformed into Mg2TiH4, TiH2 and γ-MgH2 phases with the mass fractions of 25.48 wt%, 64.0 wt%, and 10.52 wt%, respectively. Microstructure analyses show that before milling the shape of particle is mostly a ball shape, after 30 h of milling the shape of particles changes into polygonal shape, and upon hydriding the shape of particles changes from a polygonal shape into an irregular one. The final composition of the specimen after hydriding exhibits that Mg-Ti alloy can be promoted as a hydrogen storage material.

  9. Immobilization of 5-aminopyridine-2-tetrazole on cross-linked polystyrene for the preparation of a new adsorbent to remove heavy metal ions from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Chen, Youning; Wang, Chaozhan; Wei, Yinmao, E-mail: ymwei@nwu.edu.cn

    2014-07-15

    Highlights: • Novel chelating resin was prepared using pyridine-2-tetrazole as ligand. • The resin has quite high adsorption capacity for Cu(II), Pb(II) and Hg(II). • The resin shows the different selectivity from the common used IDA resin. • The preparation procedure is a two-step reaction and is easy to carry out. - Abstract: Novel 5-aminopyridine-2-tetrazole-functionalized polystyrene resin (APTZ-PS) was prepared by anchoring 5-aminopyridine-2-carbonitrile onto chloromethylated polystyrene beads (CMPS) and subsequently using the cyano-tetrazole conversion reaction. The APTZ-PS resin was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and specific surface area and pore size analyses. The adsorption experiments of the prepared resin for heavy metal ions were conducted by batch methods. The effects of the experimental conditions, such as pH, contact time and initial metal ion concentration on the adsorption properties of Cu(II), Pb(II) and Hg(II) were investigated. The results showed that the resin possessed perfect adsorption capacities for Cu(II), Pb(II) and Hg(II), and the selectivity was different from the commonly used iminodiacetic acid-chelating resin. The sorption kinetics of the three metal ions followed the pseudo-second-order equation. The adsorption isotherms for Cu(II) and Pb(II) could be better fitted by the Langmuir model than the Freundlich model, whereas the Freundlich model was the best for the Hg(II) ion. Even after five consecutive adsorption–desorption cycles, no obvious change in the adsorption capacity of the resin was found, which implied that the APTZ-PS resin was suitable for the efficient removal of heavy metal ions from aqueous solution.

  10. Preparation of alumina supported on carbon nano tubes and its application in fluoride adsorption from an aqueous solution

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel material, alumina supported on carbon nanotubes (Al2O3/CNT), was prepared from carbon nanotubes and Al(NO3)3. X-ray diffraction (XRD) spectra demonstrate that alumina is amorphous, and scanning electron microscope (SEM) images show that CNT and alumina are homogeneously mixed. Furthermore, the fluoride adsorption behavior on the surface of Ai2O3/CNT has been investigated and compared with other adsorbents. The results indicate that Al2O3/CNT has a high adsorption capacity, with a saturation adsorption capacity of 39.4 mg/g. It is also found that the adsorption capacity of AI2O3/CNT is 3.0-4.5 times that of γ-Al2O3 while almost equal to that of IRA-410polymeric resin at 25 ℃. The adsorption isotherms of fluoride on Al2O3/CNT fit the Freundlich equation well, and optimal pH ranging from 5.0 to 9.0.``

  11. Adsorption of Heavy Metals by Graphene Oxide/Cellulose Hydrogel Prepared from NaOH/Urea Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Xiong Chen

    2016-07-01

    Full Text Available By taking advantage of cellulose, graphene oxide (GO, and the process for crosslinking using epichlorohydrin (ECH, we propose a simple and novel method to prepare GO/cellulose hydrogel with good potential to adsorb metal ions. GO nanosheets containing carboxyl and hydroxyl groups were introduced into the surface of the cellulose hydrogel with retention of the gel structure and its nanoporous property. Due to the introduction of GO, the GO/cellulose composite hydrogels exhibited good compressive strength. Adsorption capacity of Cu2+ significantly increases with an increase in the GO/cellulose ratio and GO/cellulose hydrogel showed high adsorption rates. The calculated adsorption capacities at equilibrium ( q e cal for GO/cellulose hydrogel (GO:cellulose = 20:100 in weight was up to 94.34 mg·g−1, which was much higher than that of the pristine cellulose hydrogels. Furthermore, GO/cellulose hydrogel exhibited high efficient regeneration and metal ion recovery, and high adsorption capacity for Zn2+, Fe3+, and Pb2+.

  12. Removal of malachite green from aqueous solution by activated carbon prepared from the epicarp of Ricinus communis by adsorption.

    Science.gov (United States)

    Santhi, T; Manonmani, S; Smitha, T

    2010-07-15

    The use of low-cost, locally available, highly efficient and eco-friendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. This study investigates the potential use of activated carbon prepared from the epicarp of Ricinus communis for the removal of malachite green (MG) dye from simulated wastewater. The effects of different system variables, adsorbent dosage, initial dye concentration, pH and contact time were investigated and optimal experimental conditions were ascertained. The results showed that as the amount of the adsorbent increased, the percentage of dye removal increased accordingly. Optimum pH value for dye adsorption was 7.0. Maximum dye was sequestered within 50 min of the start of every experiment. The adsorption of malachite green followed the pseudo-second-order rate equation and fits the Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Tempkin equations well. The maximum removal of MG was obtained at pH 7 as 99.04% for adsorbent dose of 1 g 50 mL(-1) and 25 mg L(-1) initial dye concentration at room temperature. Activated carbon developed from R. communis can be an attractive option for dye removal from diluted industrial effluents since test reaction made on simulated dyeing wastewater showed better removal percentage of MG. 2010 Elsevier B.V. All rights reserved.

  13. Optical properties of TiO{sub 2} thin films prepared by chemical spray pyrolysis from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ayouchi, R.; Casteleiro, C.; Schwarz, R. [Departamento de Fisica, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Barrado, J.R.; Martin, F. [Laboratorio de Materiales y Superficie (Unidad Asociada al CSIC), Departamento de Fisica Aplicada I e Departamento de Ingenieria Quimica, Universidad de Malaga, 29071 Malaga (Spain)

    2010-04-15

    Titanium dioxide (TiO{sub 2}) is known to have three different kinds of polymorphous crystalline forms: rutile, anatase, and brookite. The rutile phase is always formed at higher temperatures, while the anatase phase is formed at lower temperatures and transformed into rutile phase above 800 C. Various deposition techniques have been developed for depositing TiO{sub 2} thin films, including evaporation, sputtering, chemical vapour deposition and thermal oxidation of titanium. Among them, the Chemical Spray Pyrolysis (CSP) technique has many advantages, such as good conformal coverage, the possibility of epitaxial growth and the application to large area deposition. Also, this method is low cost and it is easy to control the deposition growth parameters. In the present work, TiO{sub 2} thin films have been deposited on p-Si(001) and fused silica substrates by Chemical Spray Pyrolysis (CSP) method from aqueous solution containing titanium (IV) isopropoxide (Ti[OCH(CH{sub 3}){sub 2}]{sub 4}). As-deposited thin films show anatase polycrystalline structure, and rutile phase formed for films annealed at 750 C. SEM images have confirmed a smooth and crack-free surface with low surface roughness. X-ray photoelectron spectroscopy (XPS) combined with 4 keV Ar{sup +} depth profiling has shown that crystallized films correspond to TiO{sub 2}. Residual carbon coming from the organic precursor solution is only detected at the surface of the film. Thin films deposited on fused silica were highly transparent (more than 85%), with an indirect optical band gap of 3,43 and 3,33 eV for as-deposited and annealed films, respectively, and refractive indexes in the range between 2.01-2.29. Spectroscopic Ellipsometry (SE) also has been used to extract optical parameters. SE data fitted to triple-layer physical model revealed the same tendency to increase refractive index in annealed films. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Antitubercular activity of ZnO nanoparticles prepared by solution combustion synthesis using lemon juice as bio-fuel.

    Science.gov (United States)

    Gopala Krishna, Prashanth; Paduvarahalli Ananthaswamy, Prashanth; Trivedi, Priyanka; Chaturvedi, Vinita; Bhangi Mutta, Nagabhushana; Sannaiah, Ananda; Erra, Amani; Yadavalli, Tejabhiram

    2017-06-01

    In this study, we report the synthesis, structural and morphological characteristics of zinc oxide (ZnO) nanoparticles using solution combustion synthesis method where lemon juice was used as the fuel. In vitro anti-tubercular activity of the synthesized ZnO nanoparticles and their biocompatibility studies, both in vitro and in vivo were carried out. The synthesized nanoparticles showed inhibition of Mycobacterium tuberculosis H37Ra strain at concentrations as low as 12.5μg/mL. In vitro cytotoxicity study performed with normal mammalian cells (L929, 3T3-L1) showed that ZnO nanoparticles are non-toxic with a Selectivity Index (SI) >10. Cytotoxicity performed on two human cancer cell lines DU-145 and Calu-6 indicated the anti-cancer activity of ZnO nanoparticles at varied concentrations. Results of blood hemolysis indicated the biocompatibility of ZnO nanoparticles. Furthermore, in vivo toxicity studies of ZnO nanoparticles conducted on Swiss albino mice (for 14days as per the OECD 423 guidelines) showed no evident toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Adsorption of Pb(II) and Cd(II) from aqueous solutions using titanate nanotubes prepared via hydrothermal method.

    Science.gov (United States)

    Xiong, Lin; Chen, Cheng; Chen, Qing; Ni, Jinren

    2011-05-30

    Titanate nanotubes (TNs) with specific surface areas of 272.31 m(2)g(-1) and pore volumes of 1.264 cm(3)g(-1) were synthesized by alkaline hydrothermal method. The TNs were investigated as adsorbents for the removal of Pb(II) and Cd(II) from aqueous solutions. The FT-IR analysis indicated that Pb(II) and Cd(II) adsorption were mainly ascribed to the hydroxyl groups in the TNs. Batch experiments were conducted by varying contact time, pH and adsorbent dosage. It was shown that the initial uptake of each metal ion was very fast in the first 5 min, and adsorption equilibrium was reached after 180 min. The adsorption of Pb(II) and Cd(II) were found to be maximum at pH in the range of 5.0-6.0. The adsorption kinetics of both metal ions followed the pseudo-second-order model. Equilibrium data were best fitted with the Langmuir isotherm model, and the maximum adsorption capacities of Pb(II) and Cd(II) were determined to be 520.83 and 238.61 mg g(-1), respectively. Moreover, more than 80% of Pb(II) and 85% of Cd(II) adsorbed onto TNs can be desorbed with 0.1M HCl after 3h. Thus, TNs were considered to be effective and promising materials for the removal of both Pb(II) and Cd(II) from wastewater.

  16. Hydrolysis preparation of the compact TiO2 layer using metastable TiCl4 isopropanol/water solution for inorganic-organic hybrid heterojunction perovskite solar cells

    Science.gov (United States)

    Xiaoyan, Dai; Chengwu, Shi; Yanru, Zhang; Ni, Wu

    2015-07-01

    A hydrolysis process was applied to prepare the compact TiO2 layer using the fresh metastable TiCl4 isopropanol/water solution as the precursor solution for the preparation of the inorganic-organic hybrid heterojunction perovskite solar cells. The optimal compact TiO2 layer prepared from the aqueous solution of 2 mol/L TiCl4 diluted in isopropanol at 1 : 3 by volume as precursor solution was uniform and with a film thickness of 126 nm. The corresponding perovskite solar cell gave a photovoltaic conversion efficiency of 10.61%. Project supported by the National Natural Science Foundation of China (Nos. 51472071, 51272061, 51072043), and the National Basic Research Program of China (No. 2011CBA00700).

  17. Removal of malachite green from aqueous solution by activated carbon prepared from the Annona squmosa seed by adsorption

    Directory of Open Access Journals (Sweden)

    T. Santhi

    2010-12-01

    Full Text Available The use of low -cost, locally available, highly efficient and eco-friendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. This study investigates the potential use of activated carbon prepared from the Annona squmosa seed for the removal of malachite green (MG dye from simulated wastewater. The effects of different system variables, adsorbent dosage, initial dye concentration, pH and contact time were investigated and optimal experimental conditions were ascertained. The results showed that as the amount of the adsorbent is increased, the percentage of dye removal increase accordingly. Optimum pH value for dye adsorption was 7.0. Maximum dye was sequestered within 50 min from the start of every experiment. The adsorption of malachite green followed the pseudo-second –order rate equation and fits the Langmuir, Freundlich, Dubinin-Radushekevich (D-R and Tempkin equations well. The maximum removal of MG was obtained at pH 7 as 86.11% for adsorbent dose of 0.2 g/ 50 mL and 25 mg L -1 initial dye concentration at room temperature. Furthermore, adsorption kinetics of MG was studied and the rate of adsorption was found to conform to pseudo-second –order kinetics with a good correlation (R2 > 0.99 with intraparticle diffusion as one of the rate determining steps. Activated carbon developed from the Annona squmosa seed can be an attractive option for dye removal from diluted industrial effluents since test reaction made on simulated dyeing wastewater showed better removal percentage of MG.

  18. REMOVAL OF METHYLENE BLUE FROM AQUEOUS SOLUTION BY ACTIVATED CARBON PREPARED FROM THE PEEL OF CUCUMIS SATIVA FRUIT BY ADSORPTION

    Directory of Open Access Journals (Sweden)

    Manonmani Subbian

    2010-02-01

    Full Text Available The use of low-cost, locally available, highly efficient, and eco-friendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. This study investigates the potential use of activated carbon prepared from the peel of Cucumis sativa fruit for the removal of methylene blue (MB dye from simulated wastewater. The effects of different system variables, adsorbent dosage, initial dye concentration, pH, and contact time were investigated, and optimal experimental conditions were ascertained. The results showed that as the amount of the adsorbent increased, the percentage of dye removal increased accordingly. The optimum pH for dye adsorption was 6.0. Maximum dye was sequestered within 50 min of the start of each experiment. The adsorption of methylene blue followed the pseudo-second-order rate equation and fit the Langmuir, Freundlich, Dubinin-Radushekevich (D-R, and Tempkin equations well. Maximum removal of MB was obtained at pH 6 as 99.79% for adsorbent doses of 0.6 g/ 50 mL and 25 mg/L initial dye concentrations at room temperature. The maximum adsorption capacity obtained from the Langmuir equation was 46.73 mg g-1. The rate of adsorption was found to conform to pseudo-second-order kinetics with a good correlation (R2 > 0.9677 with intraparticle diffusion as one of the rate-determining steps. Activated carbon developed from the peel of Cucumis sativa fruit can be an attractive option for dye removal from wastewater.

  19. Preparation of a surface-grafted imprinted ceramic membrane for selective separation of molybdate anion from water solutions.

    Science.gov (United States)

    Zeng, Jianxian; Dong, Zhihui; Zhang, Zhe; Liu, Yuan

    2017-07-05

    A surface-grafted imprinted ceramic membrane (IIP-PVI/CM) for recognizing molybdate (Mo(VI)) anion was prepared by surface-initiated graft-polymerization. Firstly, raw alumina ceramic membrane (CM) was deposited with SiO2 active layer by situ hydrolysis deposition method. Subsequently, γ-methacryloxy propyl trimethoxyl silane (MPS) was used as a coupling agent to introduce double bonds onto the SiO2 layer (MPS-CM). Then, 1-vinylimidazole (VI) was employed as a functional monomer to graft-polymerization onto the MPS-CM (PVI-CM). During the graft-polymerization, the influence factors of grafting degree of PVI were investigated in detail. Under optimum conditions (monomer concentration 20wt%, temperature 70°C, initiator amount 1.1wt% and reaction time 8h), the grafting degree of 20.39g/100g was obtained. Further, Mo(VI) anion was used as a template to imprint in the PVI-CM by employing 1,6-dibromohexane as a cross-linking agent, and then Mo(VI) was removed, obtaining the IIP-PVI/CM with many imprinted cavities for Mo(VI). Thereafter, static adsorption and dynamic separation properties of IIP-PVI/CM for Mo(VI) were studied. Results indicate that IIP-PVI/CM shows a specific selectivity for Mo(VI) with the adsorption capacity of 0.69mmol/100g, and the selectivity coefficient of IIP-PVI/CM is 7.48 for molybdate to tungstate anions. During the dynamic separation, IIP-PVI/CM has also good selectivity for separation of Mo(VI) and W(VI) anions. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Preparation, Thermodynamic and Electrochemical Properties of Vanadium Solution%钒电解液的绿色制备及其热力学分析

    Institute of Scientific and Technical Information of China (English)

    吴雄伟; 彭穗; 冯必钧; 山村朝雄; 矢野贵; 佐藤伊佐務; 刘素琴; 黄可龙

    2011-01-01

    以分析纯V2O5为原料,利用双氧水还原的方法制备钒电解液,并对五氧化二钒的溶解机理进行了研究.通过UV-Vis光谱分析和ICP,对钒电解液在电解过程中钒离子的价态变化和浓度变化进行表征.通过计算,得到了钒电解液制备的反应焓变和吉布斯自由能变化,结果表明:生成硫酸氧钒的反应为放热反应,并且该反应促进了五价钒离子的溶解.将所制备的电解液组装成动态电池,在电流密度为2.4 mA/cm2时,电池的电流效率、电压效率、能量效率分别为93.6%、98.1%和91.9%,充放电结果表明:所制备的电解液具有很好的活性,可以应用于钒电池.%The vanadium solution was prepared by the mixture of hydrogen peroxide and vanadium pentoxide in sulphuric acid solution.The solubility mechanism of vanadium pentoxide was investigated.The valence and concentration change of vanadium solution were characterized by UV-Vis and ICP measurement in the following electrolysis procedure.ΔH and ΔG of the reaction were calculated.The results showed that the reaction was exothermic.The electrochemical activity was characterized by the charging and discharging experiment.And the results showed that the high current efficiency, voltage efficiency and energy efficiency of 93.6%, 98.1% and 91.9%were obtained at the current density of 2.4 mA/cm2, respectively.This indicated that the prepared vanadium solution was suitable for vanadium redox-flow battery.

  1. Preparing undergraduates for the future of scientific collaboration: Benefits, challenges and technological solutions in Distributed REU Sites

    Science.gov (United States)

    Hubenthal, M.; Anagnos, T.

    2012-12-01

    exposes all interns to a larger spectrum of research topics and approaches within a field than would be available within a single research site. Evaluations also reveal that fostering social and academic interactions among interns working on generally unrelated projects at separate locations is challenging and requires a consistent, focused effort by the program. In part this is because creating a cohort experience in this situation requires a layer of interaction beyond the networks naturally establish by the interns when co-located. A critical first step is to establish a social presence among the group. This occurs through early face-to-face meetings and then is carried forward as interns transition to virtual interactions. These virtual interactions occur through a variety of technological solutions. Both commercially and freely available technologies such as blogging software, Facebook, an online course management system, virtual worlds, and a variety of online conferencing applications are used to connect the students both synchronously and asynchronously. We have documented the strengths and weaknesses of these individual solutions and show how combinations, combined with programmatic interventions, can offer a suite of functionality necessary to facilitate both social and academic interactions and influence career paths.

  2. Preparation of novel polysulfone capsules containing zirconium phosphate and their properties for Pb{sup 2+} removal from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Ma Xiaojie [College of Chemistry and Chemical Engineering, State Key Laboratory of Applied Organic Chemistry, College of Resources and Environment, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000 (China); Li Yanfeng, E-mail: liyf@lzu.edu.cn [College of Chemistry and Chemical Engineering, State Key Laboratory of Applied Organic Chemistry, College of Resources and Environment, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000 (China); Li Xiaoli; Yang Liuqing [College of Chemistry and Chemical Engineering, State Key Laboratory of Applied Organic Chemistry, College of Resources and Environment, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000 (China); Wang Xueyan [Yantai Professional School of Automobile Engineering, Yantai 265500 (China)

    2011-04-15

    Zirconium phosphate (ZrP) was immobilized by microencapsulation process of polysulfone (PSF) to form the polysulfone capsules containing ZrP (PSF-ZrP capsules) successfully by using phase inversion precipitation technique, and the PSF-ZrP was employed as capsules adsorbents to remove Pb{sup 2+} presented in aqueous solution. The result shows that an encapsulation capacity of 50% (mass ratio, PSF: ZrP = 1:1) should be the optimal proportion of ZrP encapsulated with PSF. The characterization of the macroscopical and microcosmic physical properties of the resulting PSF-ZrP capsules was carried out by the DTA-TG, XRD, BET and SEM. Meanwhile, the adsorption properties of the PSF-ZrP capsules for Pb{sup 2+} were investigated by batch methods. It was found that the adsorption of the PSF-ZrP capsules for Pb{sup 2+} would be pH dependent due to the ion-exchange mechanism, and the uptake of Pb{sup 2+} was slightly influenced with the concentration of coexisting cations (Na{sup +}, K{sup +}) in a low range. Furthermore, the calculated thermodynamics parameters exhibit that the nature of the adsorption process is spontaneous and exothermic. After six times of adsorption-regeneration cycles, no significant loss of adsorption capacity was observed, indicating the good stability of the PSF-ZrP capsules. Consequently, the PSF-ZrP capsules in this work can provide a potential application for treatment process of Pb{sup 2+}-containing wastewater.

  3. Preparation and characterization of TiO{sub 2}/HZSM-11 zeolite for photodegradation of dichlorvos in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Silvina; Marchena, Candelaria Leal [Grupo Zeolitas, CITeQ (Centro de Investigación y Tecnología Química), Facultad Córdoba, Universidad Tecnológica Nacional, Maestro López esq. Cruz Roja Argentina, Córdoba (Argentina); Pizzio, Luis, E-mail: lrpizzio@quimica.unlp.edu.ar [Centro de Investigación y Desarrollo en Ciencias Aplicadas “Dr. J. J. Ronco” (CINDECA), Departamento de Química, Facultad de Ciencias Exactas, UNLP-CCT La Plata, 47 No. 257, 1900 La Plata, Buenos Aires (Argentina); Pierella, Liliana, E-mail: lpierella@scdt.frc.utn.edu.ar [Grupo Zeolitas, CITeQ (Centro de Investigación y Tecnología Química), Facultad Córdoba, Universidad Tecnológica Nacional, Maestro López esq. Cruz Roja Argentina, Córdoba (Argentina)

    2013-08-15

    Highlights: • TiO{sub 2}/HZMS-11(30%) sample degraded efficiently aqueous solutions of dichlorvos. • TiO{sub 2}/HZSM-11 samples did not show evidence of rutile phase. •HZMS-11 (support) is not active by itself in the degradation of dichlorvos. • The catalyst can be reused without activity loss during at least four cycles. -- Abstract: The TiO{sub 2}/HZSM-11 materials were synthesized using titanium isopropoxide as a TiO{sub 2} precursor and HZSM-11 a medium pore size zeolite with high thermal and chemical resistance as support. The amount of titanium isopropoxide was varied in order to obtain TiO{sub 2} concentrations of 3, 10, 20, 30 and 50 wt% in the final material. They were characterized by a series of complementary techniques: X-ray diffraction (XRD), ultraviolet–visible diffuse reflectance spectroscopy (DRS), transmittance Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The surface area of the TiO{sub 2}/HZSM-11 samples decreased with the increment of TiO{sub 2} loading. As result of the increment of the calcination temperature from 450 to 800 °C an increase in the size of the anatase crystals was observed. However, the X-ray diffraction patterns of the solids only presented the characteristic peaks of the anatase phase. The catalytic activity of the materials in the photodegradation of Dichlorvos (DDVP) depended on the TiO{sub 2} amount the thermal treatment temperature. The sample containing 30% TiO{sub 2} calcined at 450 °C showed the best catalytic performance and it can be reused without noticeable activity loss during at least four cycles. The catalytic performance was similar to that of the P25 Degussa used as a reference but its separation, recovery and reuse was easier.

  4. Preparation of functionalized graphene oxide and its application as a nanoadsorbent for Hg(2+) removal from aqueous solution.

    Science.gov (United States)

    Aghdam, Khaledeh; Panahi, Homayon Ahmad; Alaei, Ebrahim; Hasani, Amir Hesam; Moniri, Elham

    2016-04-01

    A poly(allyl acetoacetate)-grafted graphene oxide (GO-GAA) was successfully synthesized using Hummer's method by divinyl sulfone modification and allyl acetoacetate polymerizaton. This novel functionalized graphene oxide was characterized thoroughly by FTIR, XRD, FE-SEM, TEM, and TG-DT analyses. GO-GAA was then employed as an adsorbent for Hg(2+) removal from aqueous solutions. It exhibited higher adsorption capacity with regard to the pristine graphene oxide because of its effective functionalities, especially the dicarbonyl groups which are significant chelating agents. The effects of pH, temperature, and contact time on Hg(2+) adsorption were also investigated. The optimum Hg(2+) adsorption was obtained at pH 4 and T = 20-30 °C. The adsorption isotherm and kinetics were found to follow the Langmuir and pseudo-second-order models, respectively, with a correlation coefficient of 0.99 for both. The calculated maximum adsorption capacity of the adsorbent was 282.7 mg Hg(2+) per unit mass of GO-GAA, which is much more than 56 mg/g of that obtained for GO. The results showed that adsorption reaches up to 95 % of its maximum in less than 2 min. The synthesized GO-GAA as a novel and efficient adsorbent has been regenerated by HNO3 and reused. It retained its performance for Hg(2+) removal for several times and a less than 5 % decrease in removal efficiency was observed after four cycles of adsorption-desorption.

  5. Structural and magnetic properties of manganese zinc ferrite nanoparticles prepared by solution combustion method using mixture of fuels

    Energy Technology Data Exchange (ETDEWEB)

    Angadi, V. Jagadeesha; Rudraswamy, B. [Department of Physics, Bangalore University, Bangalore 560056 (India); Sadhana, K. [Department of Physics, University College of Science, Osmania University, Saifabad, Hyderabad 500004 (India); Praveena, K., E-mail: praveenaou@gmail.com [School of Physics, Eternal University, Baru Sahib 173101, Himachal Pradesh (India)

    2016-07-01

    The structural analysis and magnetic investigation Mn{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} with stoichiometry (x=0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) were synthesized by solution combustion method using mixture of fuel this is first of its kind. As synthesized Mn–Zn nanoferrites were characterized by X-ray Diffractometer (XRD), Transmission electron microscopy (TEM) at room temperature. The magnetic domain relaxation was investigated by inductance spectroscopy (IS) and the observed magnetic domain relaxation frequency (f{sub r}) was increased with the increase in grain size. The Room temperature magnetic properties were studied using vibrating sample magnetometer (VSM). It was observed that the real and imaginary part of permeability (μ′ and μ″), saturation magnetization (M{sub s}), remanance magnetization (M{sub r}) and magneton number (M{sub r}/M{sub s}) were decreases gradually with increasing Zn{sup 2+} concentration. The decrease in the saturation magnetization may be explained as, the Zn{sup 2+} concentration increases the relative number of ferric ions on the A sites diminishes and this reduces the A–B interaction. Hence synthesized materials are good for high frequency applications. - Highlights: • Mixture of fuels used for synthesis. • Preferred existence of Fe{sup 3+} oxidation states. • Reduction in magnetic interaction between Fe ions due to Zn{sup 2+} dilutions. • These materials are useful for high frequency applications.

  6. Physical and electrochemical characterization of CdS hollow microspheres prepared by a novel template free solution phase method

    Energy Technology Data Exchange (ETDEWEB)

    Rengaraj, S., E-mail: rengaraj.selvaraj@uef.f [University of Eastern Finland, Laboratory of Applied Environmental Chemistry (LAEC), Patteristonkatu 1, FI-50100 Mikkeli (Finland); Ferancova, A. [University of Eastern Finland, Laboratory of Applied Environmental Chemistry (LAEC), Patteristonkatu 1, FI-50100 Mikkeli (Finland); Institute of Analytical Chemistry, Slovak University of Technology in Bratislava, 81237 Bratislava (Slovakia); Jee, S.H. [Department of Chemical Engineering, Kwangwoon University, Wolgye, Nowon, Seoul 139-701 (Korea, Republic of); Venkataraj, S. [Crystal Growth Centre, Anna University, Chennai 600025 (India); Kim, Y. [Department of Chemical Engineering, Kwangwoon University, Wolgye, Nowon, Seoul 139-701 (Korea, Republic of); Labuda, J. [Institute of Analytical Chemistry, Slovak University of Technology in Bratislava, 81237 Bratislava (Slovakia); Sillanpaeae, M. [University of Eastern Finland, Laboratory of Applied Environmental Chemistry (LAEC), Patteristonkatu 1, FI-50100 Mikkeli (Finland); LUT Faculty of Technology, Lappeenranta University of Technology, Patteristonkatu 1, FI-50100 Mikkeli (Finland)

    2010-12-15

    Novel CdS hollow microspheres have been successfully synthesized via a facile template-free solution-phase reaction from cadmium nitrate and thioacetamide precursors. The morphology of CdS hollow microspheres depends strongly on the ratio between the precursors, cadmium nitrate to thioacetamide ratio. The physical properties of the hollow microspheres have systematically been studied by different characterization methods. The stoichiometry of the hollow microspheres studied by the energy dispersive X-ray diffraction spectroscopy confirmed that the synthesized CdS hollow microspheres are nearly stoichiometric bulk like CdS. The morphology of the hollow microspheres studied by high resolution scanning electron microscopy and transmission electron microscopy observations showed that the CdS hollow microspheres of the size of 2.5 {mu}m have hollow structure and are constructed by several nanoparticles of the size between 30 and 40 nm. The UV-visible diffuse reflectance spectroscopy studies showed that the band gap of the CdS hollow microspheres increased while increasing the cadmium nitrate to thioacetamide ratio. Further electrochemical characterization of CdS hollow microspheres was performed with glassy carbon electrode (GCE) after its chemical modification by CdS dispersed in dimethylformamide. The electrochemical studies showed that with decreasing the band gap energy the electron transfer resistance of CdS/GCE was also found decreased. Moreover, electrochemical impedance spectroscopic measurements showed enhanced DNA adsorption onto CdS/GCE in comparison to GCE. These experiments demonstrate that the CdS hollow microspheres act as an efficient electrode modifier that effectively decreased the charge transfer resistance and capacitance of the modified sensors, which can be used for electroanalytical purposes.

  7. Preparation and evaluation of aminopropyl-functionalized manganese-loaded SBA-15 for copper removal from aqueous solution.

    Science.gov (United States)

    Lei, Di; Zheng, Qianwen; Wang, Yili; Wang, Hongjie

    2015-02-01

    A novel material, aminopropyl-functionalized manganese-loaded SBA-15 (NH2-Mn-SBA-15), was synthesized by bonding 3-aminopropyl trimethoxysilane (APTMS) onto manganese-loaded SBA-15 (Mn-SBA-15) and used as a Cu2+ adsorbent in aqueous solution. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction spectra (XRD), N2 adsorption/desorption isotherms, high resolution field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the NH2-Mn-SBA-15. The ordered mesoporous structure of SBA-15 was remained after modification. The manganese oxides were mainly loaded on the internal surface of the pore channels while the aminopropyl groups were mainly anchored on the external surface of SBA-15. The adsorption of Cu2+ on NH2-Mn-SBA-15 was fitted well by the Langmuir equation and the maximum adsorption capacity of NH2-Mn-SBA-15 for Cu2+ was over two times higher than that of Mn-SBA-15 under the same conditions. The Elovich equation gave a good fit for the adsorption process of Cu2+ by NH2-Mn-SBA-15 and Mn-SBA-15. Both the loaded manganese oxides and the anchored aminopropyl groups were found to contribute to the uptake of Cu2+. The NH2-Mn-SBA-15 showed high selectivity for copper ions. Consecutive adsorption-desorption experiments showed that the NH2-Mn-SBA-15 could be regenerated by acid treatment without altering its properties.

  8. Effect of (Fe, Co) co-doping on the structural, electrical and magnetic properties of ZnO nanocrystals prepared by solution combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Ram, Mast, E-mail: mastram1999@yahoo.com; Negi, N.S.

    2016-01-15

    The structural, electrical and magnetic properties of Zn{sub 1−x}Co{sub 0.05}Fe{sub x}O (where, x=0, 1, 2, 3 and 5 mol%) nanoparticles prepared by solution combustion method are reported. The X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive analysis of X-rays (EDX) have been used for structural and compositional analysis. The X-ray diffraction pattern showed the existence of hexagonal wurtzite structure of parent ZnO with co-doping. The microstructural studies reveal the dense nanostructured morphology of these samples. The DC electrical conductivity measurements have been carried out in the temperature range of 300–450 K. The DC electrical conductivity decreases with the increasing Fe concentration. The magnetic studies reveal room temperature ferromagnetisation in doped ZnO nanoparticles. The magnetic properties of ZnO nanoparticles improve with increasing Fe dopant concentration.

  9. Ni-loaded nanocrystalline ceria-zirconia solid solutions prepared via modified Pechini route as stable to coking catalysts of CH4 dry reforming

    Directory of Open Access Journals (Sweden)

    Sadykov Vladislav A.

    2016-01-01

    Full Text Available Mixed nanocrystalline Ce-Zr-O oxides (Ce/Zr = 1 or 7/3 were prepared by modified Pechini route using ethylene glycol solutions of metal salts. Detailed characterization of their real structure and surface properties by X-ray diffraction on synchrotron radiation with the full-profile Rietveld analysis, high resolution electron microscopy with elemental analysis, Raman spectroscopy, UV-Vis and X-ray photoelectron spectroscopy revealed a high homogeneity of cations distribution in nanodomains resulting in stabilization of disordered cubic phase. This provides a high dispersion of NiO loaded on these mixed oxides by wet impregnation, a high reactivity and mobility of oxygen in these catalysts and strong interaction of Ni with support in the reduced state. This helps to achieve a high activity and coking stability of developed catalysts in CH4 dry reforming in feeds with CH4 concentration up to 15% and CH4/CO2 ratio =1.

  10. Properties of nano-structured Ni/YSZ anodes fabricated from plasma sprayable NiO/YSZ powder prepared by single step solution combustion method

    Science.gov (United States)

    Prakash, B. Shri; Balaji, N.; Kumar, S. Senthil; Aruna, S. T.

    2016-12-01

    NiO/YSZ anode coatings are fabricated by atmospheric plasma spraying at different plasma powers from plasma grade NiO/YSZ powders that are prepared in a single step by solution combustion method. The process adopted is devoid of multi-steps that are generally involved in conventional spray drying or fusing and crushing methods. Density of the coating increased and porosity decreased with increase in the plasma power of deposition. An ideal nano-structured Ni/YSZ anode encompassing nano YSZ particles, nano Ni particles and nano pores is achieved on reducing the coating deposited at lower plasma powers. The coating exhibit porosities in the range of 27%, sufficient for anode functional layers. Electronic conductivity of the coatings is in the range of 600 S/cm at 800 °C.

  11. Preparation of a disulfide-linked precipitative soluble support for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3´-(2-chlorophenylphosphate building blocks

    Directory of Open Access Journals (Sweden)

    Amit M. Jabgunde

    2015-09-01

    Full Text Available The preparation of a disulfide-tethered precipitative soluble support and its use for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3´-(2-chlorophenylphosphate building blocks is described. To obtain the building blocks, N-acyl protected 2´-deoxy-5´-O-(4,4´-dimethoxytritylribonucleosides were phosphorylated with bis(benzotriazol-1-yl 2-chlorophenyl phosphate. The “outdated” phosphotriester strategy, based on coupling of PV building blocks in conjunction with quantitative precipitation of the oligodeoxyribonucleotide with MeOH is applied. Subsequent release of the resulting phosphate and base-protected oligodeoxyribonucleotide trimer 3’-pTpdCBzpdGibu-5’ as its 3’-(2-chlorophenyl phosphate was achieved by reductive cleavage of the disulfide bond.

  12. Preparation of a disulfide-linked precipitative soluble support for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3´-(2-chlorophenylphosphate) building blocks

    Science.gov (United States)

    Molina, Alejandro Gimenez; Virta, Pasi; Lönnberg, Harri

    2015-01-01

    Summary The preparation of a disulfide-tethered precipitative soluble support and its use for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3´-(2-chlorophenylphosphate) building blocks is described. To obtain the building blocks, N-acyl protected 2´-deoxy-5´-O-(4,4´-dimethoxytrityl)ribonucleosides were phosphorylated with bis(benzotriazol-1-yl) 2-chlorophenyl phosphate. The “outdated” phosphotriester strategy, based on coupling of PV building blocks in conjunction with quantitative precipitation of the oligodeoxyribonucleotide with MeOH is applied. Subsequent release of the resulting phosphate and base-protected oligodeoxyribonucleotide trimer 3’-pTpdCBzpdGibu-5’ as its 3’-(2-chlorophenyl phosphate) was achieved by reductive cleavage of the disulfide bond. PMID:26664575

  13. Preparation of acetylated waxy, normal, and high-amylose maize starches with intermediate degrees of substitution in aqueous solution and their properties.

    Science.gov (United States)

    Luo, Zhi-Gang; Shi, Yong-Cheng

    2012-09-19

    Acetylated waxy, normal, and high-amylose maize starches with intermediate degrees of substitution (DS) were prepared in aqueous solution with 20% (w/w) sodium hydroxide as a catalyst. The level of DS was in the order high-amylose maize starch > waxy maize starch > normal maize starch. Settling volume indicated that during the early reaction, normal maize starch swelled to a lesser extent compared with waxy and high-amylose maize starches. The settling volume of all three starches increased initially but decreased after long reaction time. Aggregation of granules was observed as DS increased. The A-type X-ray diffraction pattern of acetylated normal and waxy maize starches weakened as DS increased, whereas the diffraction peaks disappeared in acetylated high-amylose starch when DS was 0.95. Low DS promoted the swelling of the starches in water, but at high DS, the starches became more hydrophobic and the peak viscosity of acetylated starches decreased.

  14. Preparation of hydrophilic poly(lactic acid) tissue engineering scaffold via (PLA)-(PLA-b-PEG)-(PEG) solution casting and thermal-induced surface structural transformation.

    Science.gov (United States)

    Zhu, Xiaomin; Zhong, Tian; Huang, Ran; Wan, Ajun

    2015-01-01

    Porous poly(lactic acid) (PLA) tissue engineering scaffolds with a hydrophilic surface assembled by polyethylene glycol aggregations were prepared by the solvent casting/particulate leaching method from (PLA)-(PLA-b-PEG)-(PEG) blend solution, where the PLA-b-PEG block polymer serves as an amphiphilic glue between two phases. A thermal recrystallization process was inserted before leaching to induce a phase separation, which subsequently squeezes out PEG to form a hydrophilic shell. Characterizations of XRD and DSC indicated the composition and mixing states of materials. The water contact angle test qualitatively presented the excellent hydrophilicity compared to the pure PLA or PLA-PEG simple blend scaffold. The scanning electron microscope results confirmed the formation of porous structure of [Formula: see text] pore size, with an observable phase separation on the surface. The scaffold was degraded in PBS at [Formula: see text], and the degradation exhibits a three-stage behavior, which evidenced the amphiphilically glued phase separations.

  15. Preparation of cross-linked magnetic chitosan-phenylthiourea resin for adsorption of Hg(II), Cd(II) and Zn(II) ions from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Monier, M., E-mail: monierchem@yahoo.com [Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt); Abdel-Latif, D.A. [Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer Chitosan was chemically modified through the reaction with phenylisothiocyanate. Black-Right-Pointing-Pointer The modified chitosan-phenylthiourea cross-linked with formaldehyde in presence of magnetite to produce modified magnetic resin. Black-Right-Pointing-Pointer The resulted resin characterized by various instrumental methods. Black-Right-Pointing-Pointer The resin was applied to remove Hg{sup 2+}, Cd{sup 2+} and Zn{sup 2+} from aqueous solutions. - Abstract: In this study, cross-linked magnetic chitosan-phenylthiourea (CSTU) resin were prepared and characterized by means of FTIR, {sup 1}H NMR, SEM high-angle X-ray diffraction (XRD), magnetic properties and thermogravimetric analysis (TGA). The prepared resin were used to investigate the adsorption properties of Hg(II), Cd(II) and Zn(II) metal ions in an aqueous solution. The extent of adsorption was investigated as a function of pH and the metal ion removal reached maximum at pH 5.0. Also, the kinetic and thermodynamic parameters of the adsorption process were estimated. These data indicated that the adsorption process is exothermic and followed the pseudo-second-order kinetics. Equilibrium studies showed that the data of Hg(II), Cd(II) and Zn(II) adsorption followed the Langmuir model. The maximum adsorption capacities for Hg(II), Cd(II) and Zn(II) were estimated to be 135 {+-} 3, 120 {+-} 1 and 52 {+-} 1 mg/g, which demonstrated the high adsorption efficiency of CSTU toward the studied metal ions.

  16. CdS/CdSe-sensitized solar cell based on Al-doped ZnO nanoparticles prepared by the decomposition of zinc acetate solid solution

    Science.gov (United States)

    Deng, Jianping; Wang, Minqiang; Ye, Wei; Fang, Junfei; Zhang, Pengchao; Yang, Yongping; Yang, Zhi

    2017-01-01

    In the study, Al-doped ZnO nanoparticles (Al-ZnO NPs) were prepared by the decomposition of zinc acetate solid solution. The X-ray diffraction results showed that Al3+ was successfully doped without the formation of Al and Al2O3 impurity phases. The less Al-doping did not change the hexagonal wurtzite crystal structure of ZnO. The ratio of Al to Al + Zn (9.05%) measured by the energy dispersive X-ray also confirmed the formation of Al-ZnO. The Al-ZnO NPs were used as the photoanode material to prepare CdS/CdSe-sensitized solar cell. Compared with the cell based on commercial ZnO NPs (C-ZnO), the short-circuit current density and the fill factor of the cell were increased from 5.8 mA/cm2 and 34.1% (C-ZnO) to 7.78 mA/cm2 and 48.7% (Al-ZnO), respectively. The cell efficiency was increased from 1.01% (C-ZnO) to (1.9%) (Al-ZnO) and the increase percentage reached 88.1%. The results of electrochemical impedance spectroscopy and open-circuit voltage-decay suggested the lower carrier transport resistance and the longer electron lifetime of Al-ZnO-based cell.

  17. Preparation of cross-linked magnetic chitosan-phenylthiourea resin for adsorption of Hg(II), Cd(II) and Zn(II) ions from aqueous solutions.

    Science.gov (United States)

    Monier, M; Abdel-Latif, D A

    2012-03-30

    In this study, cross-linked magnetic chitosan-phenylthiourea (CSTU) resin were prepared and characterized by means of FTIR, (1)H NMR, SEM high-angle X-ray diffraction (XRD), magnetic properties and thermogravimetric analysis (TGA). The prepared resin were used to investigate the adsorption properties of Hg(II), Cd(II) and Zn(II) metal ions in an aqueous solution. The extent of adsorption was investigated as a function of pH and the metal ion removal reached maximum at pH 5.0. Also, the kinetic and thermodynamic parameters of the adsorption process were estimated. These data indicated that the adsorption process is exothermic and followed the pseudo-second-order kinetics. Equilibrium studies showed that the data of Hg(II), Cd(II) and Zn(II) adsorption followed the Langmuir model. The maximum adsorption capacities for Hg(II), Cd(II) and Zn(II) were estimated to be 135 ± 3, 120 ± 1 and 52 ± 1 mg/g, which demonstrated the high adsorption efficiency of CSTU toward the studied metal ions.

  18. Kinetics and thermodynamics of adsorption of ionizable aromatic compounds from aqueous solutions by as-prepared and oxidized multiwalled carbon nanotubes.

    Science.gov (United States)

    Sheng, G D; Shao, D D; Ren, X M; Wang, X Q; Li, J X; Chen, Y X; Wang, X K

    2010-06-15

    The adsorption of 1-naphthylamine, 1-naphthol and phenol on as-prepared and oxidized multiwalled carbon nanotubes (MWCNTs) has been investigated. The results illustrated that both as-prepared and oxidized MWCNTs showed high adsorption capacity for the three ionizable aromatic compounds (IACs) studied. Oxidation of MWCNTs increased the surface area and the pore volume, and introduced oxygen-containing functional groups to the surfaces of MWCNTs, which depressed the adsorption of IACs on MWCNTs. Both Langmuir and Freundlich models described the adsorption isotherms very well and the adsorption thermodynamic parameters (DeltaG degrees, DeltaH degrees and DeltaS degrees) were measured. The adsorption for 1-naphthylamine, 1-naphthol and phenol is general spontaneous and thermodynamically favorable. The adsorption of phenol is an exothermic process, whereas the adsorption of 1-naphthylamine and 1-naphthol is an endothermic process. Results of this work are of great significance for the environmental application of MWCNTs for the removal of IACs from large volume of aqueous solutions.

  19. Structure and magnetic/electrochemical properties of Cu-doped BiFeO3 nanoparticles prepared by a simple solution method

    Science.gov (United States)

    Khajonrit, Jessada; Phumying, Santi; Maensiri, Santi

    2016-06-01

    BiFe1- x Cu x O3 (x = 0, 0.05, 0.1, 0.2, and 0.3) nanoparticles were prepared by a simple solution method. The prepared nanoparticles were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) method analysis using the Barret-Joyner-Halenda (BJH) model, and X-ray absorption spectroscopy (XAS). Magnetization properties were obtained using a vibrating sample magnetometer (VSM) at room temperature. Magnetization was clearly enhanced by increasing Cu content and decreasing particle size. Zero-field-cooled (ZFC) and field-cooled (FC) temperature-dependent magnetization measurements showed that blocking temperature increased with increasing Cu content. Electrochemical properties were investigated by cyclic voltammetry (CV) and the galvanostatic charge-discharge (GCD) method. The performance of the fabricated supercapacitor was improved for the BiFe0.95Cu0.05O3 electrode. The highest specific capacitance was 568.13 F g-1 at 1 A g-1 and the capacity retention was 77.13% after 500 cycles.

  20. Preparation and characterization activated carbon from rice husk and oil palm empty fruit bunches for removal of Zn2+ in aqueous solution

    Science.gov (United States)

    Ismail, Nur Enzati Afwana; Taha, Mohd F.; Ramli, Anita

    2016-11-01

    The ability of activated carbon prepared from rice husk (RH), oil palm empty fruit bunches (EFB) and mixture (Mix) activated carbon in adsorption of Zinc (Zn2+) from aqueous solution was investigated. The Mix activated carbon has prepared from mixture of RH and EFB activated carbon with weight ratio (1:1) The RH and EFB activated carbon were produced by using sodium hydroxide (NaOH) as a dehydrating agent in chemical activation process.EFB activated carbon showed excellent efficiency in removing Zn2+ with their percentage removal up to 100% even at low adsorbent dosage. The study also showed that the adsorption of Zn2+ by EFB, RH and Mix activated carbon is dependent on the adsorbent dosage and initial metal concentration. The adsorption isotherms of the Zn2+ of EFB, RH and Mix activated carbon were determined and compared with Langmuir and Freundlich models. It was showed that Langmuir model was more favorable for RH and Mix activated carbon with correlation coefficient (R2) value is 0.9958 and 0.9847. In contrast, EFB activated carbon was more favorable to the Freundlich and Langmuir model with correlation coefficient (R2) are 0.9967 and 0.9967

  1. Nanostructured p-type CZTS thin films prepared by a facile solution process for 3D p-n junction solar cells.

    Science.gov (United States)

    Park, Si-Nae; Sung, Shi-Joon; Sim, Jun-Hyoung; Yang, Kee-Jeong; Hwang, Dae-Kue; Kim, JunHo; Kim, Gee Yeong; Jo, William; Kim, Dae-Hwan; Kang, Jin-Kyu

    2015-07-07

    Nanoporous p-type semiconductor thin films prepared by a simple solution-based process with appropriate thermal treatment and three-dimensional (3D) p-n junction solar cells fabricated by depositing n-type semiconductor layers onto the nanoporous p-type thin films show considerable photovoltaic performance compared with conventional thin film p-n junction solar cells. Spin-coated p-type Cu2ZnSnS4 (CZTS) thin films prepared using metal chlorides and thiourea show unique nanoporous thin film morphology, which is composed of a cluster of CZTS nanograins of 50-500 nm, and the obvious 3D p-n junction structure is fabricated by the deposition of n-type CdS on the nanoporous CZTS thin films by chemical bath deposition. The photovoltaic properties of 3D p-n junction CZTS solar cells are predominantly affected by the scale of CZTS nanograins, which is easily controlled by the sulfurization temperature of CZTS precursor films. The scale of CZTS nanograins determines the minority carrier transportation within the 3D p-n junction between CZTS and CdS, which are closely related with the photocurrent of series resistance of 3D p-n junction solar cells. 3D p-n junction CZTS solar cells with nanograins below 100 nm show power conversion efficiency of 5.02%, which is comparable with conventional CZTS thin film solar cells.

  2. Electrolytic preparation of iron from aqueous solution using solar energy%利用太阳能在水溶液中电解制铁

    Institute of Scientific and Technical Information of China (English)

    董洪波; 侯明山; 刘超; 刘润藻; 李士琦

    2012-01-01

    以太阳能电池板光伏转换所得电能为电源,采用正交试验对电解氯化亚铁溶液制取纯铁的工艺进行优化,得到最佳电解参数为:FeCl2·4H2O375g/L,pH=2.0,电流密度3 A/dm2,温度50℃.在最佳工艺下,电流效率和电沉积速率分别达到88.9%和0.45 g/h,所得铁表面光滑,呈银白色金属光泽.利用太阳能电解制铁对以后的清洁能源制铁具有一定的借鉴作用.%With the electric energy obtained by photovoltaic technology using solar-cell panels as the power supply, the process parameters for preparation of pure iron from aqueous ferrous chloride solution by electrolysis were optimized by orthogonal test as follows: FeCl2-4H2O 375 g/L, pH 2.0, current density 3 A/dm2, and temperature 50 °C. Under the optimal parameters, the current efficiency and deposition rate are up to 88.95% and 0.45 g/L respectively and the surface of the obtained iron is smooth with silvery white color and metallic luster. The electrolytic preparation of iron using solar energy gives reference to the future preparation of iron with clean energy.

  3. Green preparation of a novel red mud@carbon composite and its application for adsorption of 2,4-dichlorophenoxyacetic acid from aqueous solution.

    Science.gov (United States)

    Kazak, Omer; Eker, Yasin Ramazan; Akin, Ilker; Bingol, Haluk; Tor, Ali

    2017-08-19

    This study reports the eco-friendly preparation of a novel composite material consisting of red mud and carbon spheres, denoted as red mud@C composite, and its application for the removal of 2,4-dichlorophenoxyacetic acid herbicide (2,4-D) from aqueous solution. The preparation route has a green approach because it follows the low-energy consuming one-step hydrothermal process by using starch as a renewable carbon precursor and red mud as a waste from aluminum production industry. Characterization of the red mud@C composite was performed by FT-IR, TGA, SEM, TEM, BET, XRD, and Raman microscopy analyses. The batch adsorption studies revealed that the red mud@C composite has higher 2,4-D adsorption efficiency than those of the red mud and the naked carbon spheres. The maximum removal at initial pH of 3.0 is explained by considering the pKa of 2,4-D and pH of point of zero charge (pHpzc) of the composite material. The adsorption equilibrium time was 60 min, which followed the pseudo-second-order kinetic model together with intra-particle diffusion model. The isotherm analysis indicated that Freundlich isotherm model better represented the adsorption data, with isotherm parameters of k [15.849 (mg/g) (mg/L)(-1/n) ] and n (2.985). The prepared composite is reusable at least 5 cycles of adsorption-desorption with no significant decrease in the adsorption capacity.

  4. Preparation of Cu-loaded SrTiO{sub 3} nanoparticles and their photocatalytic activity for hydrogen evolution from methanol aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Bui, Duc-Nguyen [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Mu, Jin, E-mail: mujin@sit.edu.cn [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); Wang, Lei [School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Kang, Shi-Zhao; Li, Xiangqing [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China)

    2013-06-01

    Cu-loaded SrTiO{sub 3} nanoparticles (Cu–SrTiO{sub 3}) were prepared using a simple in situ photo-deposition method and their photocatalytic activity for hydrogen evolution from methanol aqueous solution was evaluated. The results characterized with XRD, TEM, XPS and EDX indicated that the as-synthesized sample was composed of metallic Cu and cubic SrTiO{sub 3}, and the metallic Cu was homogeneously loaded on the surface of SrTiO{sub 3} nanoparticles. Under UV light irradiation, Cu–SrTiO{sub 3} displayed much higher photocatalytic activity for hydrogen evolution and excellent stability in comparison with pure SrTiO{sub 3} nanoparticles. The results further confirmed that the efficient separation of photogenerated electron/hole pairs was critical for the enhanced photocatalytic activity of Cu–SrTiO{sub 3}. Moreover, the rate of hydrogen evolution of 0.5 wt.% Cu–SrTiO{sub 3} is comparable with that of 0.5 wt.% Pt–SrTiO{sub 3} photocatalyst under optimum conditions, implying that the metallic Cu is an efficient alternative to Pt as a co-catalyst on SrTiO{sub 3}. The high photocatalytic activity, low cost and chemical stability mean that the Cu-loaded SrTiO{sub 3} is a potential catalyst for the photocatalytic hydrogen evolution from methanol aqueous solution.

  5. Preparation, physicochemical analysis and molecular modeling investigation of 2,2‧-Bipyridine: β-Cyclodextrin inclusion complex in solution and solid state

    Science.gov (United States)

    Periasamy, R.; Kothainayaki, S.; Sivakumar, K.

    2015-11-01

    Supramolecular interaction between 2,2‧-Bipyridine (BPY) and β-Cyclodextrin (β-CD) has been investigated in solution and solid state. Non-covalent interaction between BPY and β-CD was studied in solution using absorption and fluorescence spectroscopy. Inclusion complex of BPY and β-CD was prepared in solid state by co-precipitation method and it was characterized using Fourier Transform Infra-red spectroscopy (FT-IR), Thermal analysis, Scanning Electron Microscopy (SEM), Powder X-ray diffractometry (XRD) and Atomic Force Microscopy (AFM). Binding constant values and 1:1 stoichiometry of the inclusion complex were calculated using Benesi-Hildebrand plots at 303 K. Using continuous variation method the 1:1 stoichiometry has been confirmed for BPY: β-CD complex. Thermodynamic parameter, ΔG of inclusion complex formation was determined and the negative value indicated that the inclusion process was an exergonic and spontaneous process. The most probable model of BPY: β-CD inclusion complex suggested by molecular docking studies was in good agreement with the results obtained by experimental methods.

  6. Characterization and Photocatalytic Activity ofMixed Nanocrystalline TiO2 Powders Prepared by Xerogel-Hydrothermal Method in Different Acid Solutions

    Institute of Scientific and Technical Information of China (English)

    刘翠萍; 于涛; 谭欣

    2016-01-01

    TiO2 nanoparticles(NPs)were prepared via the hydrothermal route of TiO2 xerogel in nitric acid, hy-drochloric acid and acetic acid. The physico-chemical properties of the powders were characterized by X-ray dif-fraction(XRD)and N2 adsorption desorption techniques. The effects of the different acids on the structure(crystal phase)and texture(primary particle size and porosity)of the TiO2 powders were explored. Results indicated that acetic acid facilitated the formation and stability of pure anatase phase. On the other hand, nitric acid and hydro-chloric acid led to the transformation from anatase to rutile. The catalyst synthesized via the hydrothermal route of TiO2 xerogel in the low concentration hydrochloric acid solution(Ti-HCl-0.15)had the highest photocatalytic activ-ity than the catalysts obtained in the other two acid solutions. The effects of the different acids were discussed in terms of acid strength, chelating effect and the thermal stability of the adsorbed acidic anions.

  7. Preparation and characterization of novel nano-mineral for the removal of several heavy metals from aqueous solution: Batch and continuous systems

    Directory of Open Access Journals (Sweden)

    Kumars Seifpanahi Shabani

    2017-05-01

    Full Text Available Results of studies of the sorption activity of diatomite nanoparticles, diatomite–perlite composite nanoparticles and perlite nanoparticles that was provided from internal resource at Iran, with respect to Fe(II, Cu(II, Mn(II and Cr(III ions are presented. Thus, diatomite nanoparticles, diatomite–perlite composite nanoparticles and perlite nanoparticles were modified and prepared via particle size decreasing and characterized by XRD, XRF, BET, SEM, TEM and FT-IR. In the batch system the influence of pH, adsorbent dosage, temperature and ions initial concentration was investigated. The results of isotherm and kinetics studies show that the Langmuir isotherm and pseudo-second order kinetic showed better correlation with the experimental data. Calculations of thermodynamic parameters show the negative ΔG° values or spontaneous reaction, the enthalpy (ΔH° change shows the endothermic process and values of ΔS° indicate low randomness at the solid/solution interface during the uptake of ions. Finally, three adsorbents were packed inside a glass column as a continuous system and the breakthrough curves were obtained. All results show that the ion affinity to adsorption onto adsorbents is as follows: Cu(II > Fe(II > Mn(II > Cr(III. So, these abundant, locally available cheap minerals showed a greater efficiency for the removal of metal ions from the aqueous solution, also can be utilized for other water pollutants.

  8. Preparation of chitosan/poly(acrylic acid) magnetic composite microspheres and applications in the removal of copper(II) ions from aqueous solutions.

    Science.gov (United States)

    Yan, Han; Yang, Lingyun; Yang, Zhen; Yang, Hu; Li, Aimin; Cheng, Rongshi

    2012-08-30

    In this current work, the magnetic composite microspheres (MCM), consisting of Fe(3)O(4) nanoparticles and poly(acrylic acid) (PAA) blended chitosan (CS), were prepared successfully by a simple method, co-precipitation of the compounds in alkaline solution. SEM, FTIR and TG techniques have been applied to investigate the structures of the MCM materials. The vibrating-sample magnetometer (VSM) measurement illustrated a paramagnetic property as well as a fast magnetic response, which indicated the significant separability of the MCM in the aqueous suspensions. Then, the MCM materials were employed as absorbents for removal of copper(II) (Cu(II)) ions from aqueous solutions. The fundamental adsorption behaviors of MCM were studied also. Experimental results revealed that the CS/PAA-MCM had greater adsorption capacity than CS-MCM, and PAA played an important role for the adsorption of Cu(II) ions. Moreover, the adsorption isotherms were all well described by the Langmuir model, while the adsorption kinetics followed the pseudo-second order equation. Furthermore, the adsorbent could be easily regenerated at lower pH and reused almost without any loss of adsorption capacity. On the contrary, the Cu(II) ions loaded CS-MCM and CS/PAA-MCM were stable enough at pH higher than 4.0, and both exhibited efficient phosphate removal with maximal uptakes around 63.0 and 108.0 mg Pg(-1), respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Preparation, characterization and application of alkaline leached CuNiZn ternary coatings for long-term electrolysis in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Solmaz, Ramazan [Bingoel University, Science and Letters Faculty, Chemistry Department, 12000 Bingoel (Turkey); Doener, Ali; Kardas, Guelfeza [Cukurova University, Science and Letters Faculty, Chemistry Department, 01330 Balcali Adana (Turkey)

    2010-10-15

    The NiCuZn ternary coating was electrochemically deposited on a copper electrode. Then, it was etched in a concentrated alkaline solution (30% NaOH) to produce a porous and electrocatalytic surface suitable for use in the hydrogen evolution reaction (HER). The surface composition of coating before and after alkaline leaching was determined by energy dispersive X-ray (EDX) analysis. The surface morphologies were investigated by scanning electron microscopy (SEM). The long-term stability of electrode prepared for alkaline water electrolysis was investigated in 1 M KOH solution with the help of cathodic current-potential curves and electrochemical impedance spectroscopy (EIS) techniques. It was found that, the NiCuZn coating has a compact and porous structure with good physical stability. Alkaline leaching process further improved the activity of NiCuZn coating in comparison with binary NiCu deposit for the HER. The long-term operation at -100 mA cm{sup -2} showed good electrochemical stability over 120 h. (author)

  10. Preparation of titanate nanoflower for sorption of {sup 75}Se(IV) radioisotope from aqueous solution. Equilibrium, kinetic and thermodynamic studies

    Energy Technology Data Exchange (ETDEWEB)

    Abd El-Kader Sharaf El-Deen, Sahar El-Sayed; Allan, Karam Fatwhi; Holeil, Mohamed [Atomic Energy Authority, Inshas (Egypt). Dept. of Nuclear Chemistry; Abd El-Kader Sharaf El-Deen, Gehan El-Sayed [Atomic Energy Authority, Inshas (Egypt). Dept. of Radioactive Waste Treatment

    2015-07-01

    In this study, the adsorptive removal of selenium (IV) from aqueous solution by titanate nanoflower (TNF) was prepared via alkaline hydrothermal method. The morphology and crystal phase of the TNF were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscope (EDX), selected area electron diffraction (SAED), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR) and specific surface area. This study was conducted to determine the influence of various operating parameters such as pH, adsorbate weight, initial anion concentration, contact time and solution temperature on the adsorptive removal of selenium (IV). Equilibrium adsorption data were analyzed using Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherm models. The results demonstrated that the adsorption was well described by the Langmuir adsorption isotherm with the maximum adsorption capacity up to 46.52 mg/g at pH 3.5. The adsorption of Se(IV) anions onto the surface of TNF may proceed through outer sphere electrostatic interactions and/or inner-sphere complexation interaction. The kinetic data indicated that the adsorption fit well with the pseudo-second-order kinetic model. The thermodynamic parameters implied that the adsorption process was spontaneous and endothermic in nature.

  11. Facile preparation of magnetic separable powdered-activated-carbon/Ni adsorbent and its application in removal of perfluorooctane sulfonate (PFOS) from aqueous solution.

    Science.gov (United States)

    Liang, Xuanqi; Gondal, Mohammed A; Chang, Xiaofeng; Yamani, Zain H; Li, Nianwu; Lu, Hongling; Ji, Guangbin

    2011-01-01

    The main aim of this study was to synthesize magnetic separable Nickel/powdered activated carbon (Ni/PAC) and its application as an adsorbent for removal of PFOS from aqueous solution. In this work, the synthesized adsorbent using simple method was characterized by using X-ray diffractionometer (XRD), surface area and pore size analyzer, vibrating sample magnetometer (VSM), and high resolution transmission electron microscope (HRTEM). The surface area, pore volume and pore size of synthesized PAC was 1521.8 m(2)g(-1), 0.96 cm(3)g(-1), 2.54 nm, respectively. Different kinetic models: the pseudo-first-order model, the pseudo-second-order model, and three adsorption isotherms--Langmuir, Freundlich and Temkin--were applied to study the sorption kinetics and isothermal behavior of PFOS onto the surface of an as-prepared adsorbent. The rate constant using the pseudo-second-order model for removal of 150 ppm PFOS was estimated as 8.82×10(-5) and 1.64×10(-4) for PAC and 40% Ni/PAC, respectively. Our results demonstrated that the composite adsorbents exhibited a clear magnetic hysteretic behavior, indicating the potential practical application in magnetic separation of adsorbents from aqueous solution phase as well.

  12. Investigation of Nano Particles Efficiency Prepared from Cedar Fly Ash (Zizyphus Spinachristi for Lead (Pb+2 Removal from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Laleh Divband

    2012-04-01

    Full Text Available Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background and Objectives: Existence of Heavy metals in water resources is one of the most important environmental problems in many countries. These metals have dangerous effects on human health. The purpose of this study is  to investigate and compare lead removal by nanometer and millimeter absorbents of Zizyphus Spinachristi fly ash.Materials and Methods: This study was non-continuous experiment which was implemented under laboratory conditions with and by changing effective factors such as pH (3, 4, 5, 6, 7, 8, contact time (5, 10, 15, 30, 45, 60, 90, 120 minutes and adsorbent concentration (1, 2, 5, 10, 20 and 50 mg/ L. The data was fitted based on four models including Ho et al, Lagergern, Lungmuir and Freundlich which the first two models used for absorption kinetic and the latter two considered as absorption isotherm.Results: The Result of this study showed that as the pH increases from 3 to 5 adsorption efficiency increased as well. Furthermore, when pH was over 5, the metal ions settled down. With increasing contact time, adsorption efficiency increased as well. With increasing the amount of nanometer as an adsorbent, removal efficiency increased and then decreased. Also the adsorption process followed precisely Ho et al kinetic and Langmuir isotherm, for both absorbents. Conclusion: Based on the obtained results, specific area of the nano particles was more than millimeter particles (29.56 m2/g & 17.80 m2/g, therefore adsorption capacity of nano absorbent was four times more than adsorption capacity of millimeter (19.93 mg/g & 17.80 mgr/g. Furthermore, the findings concluded high capability of nano particles towards Sorption of lead ions (Pb from aqueous solutions. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso

  13. Electrochemical preparation of NiAl intermetallic compound from solid oxides in molten CaCl{sub 2} and its corrosion behaviors in NaCl aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Yin Huayi; Yu Tang; Tang Diyong; Ruan Xuefeng; Zhu Hua [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Wang Dihua, E-mail: wangdh@whu.edu.cn [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Stoichiometric NiAl powder was prepared by one-step electrolysis of solid NiO-NiAl{sub 2}O{sub 4} in molten CaCl{sub 2}. Black-Right-Pointing-Pointer The energy consumption was as low as 6.1 kWh (kg-NiAl){sup -1}. Black-Right-Pointing-Pointer Uniform distribution and co-reduction of Ni and Al oxide played key role for Al retaining. Black-Right-Pointing-Pointer Electrolytic NiAl powder was made into dense NiAl rod by spark plasma sintering (SPS). Black-Right-Pointing-Pointer Obtained NiAl rod was self-passivated in NaCl solution and show very high corrosion resistance. - Abstract: Nickel aluminide powders were prepared by direct electrochemical reduction of solid mixture of NiO-NiAl{sub 2}O{sub 4} (Ni:Al = 1:1 in mol) precursor in molten CaCl{sub 2} at 850 Degree-Sign C. The reduction process of the solid oxide cathode was investigated by analyzing the intermediate products using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It reveals that nickel is preferentially reduced and it benefits to prevent aluminum leaving from the cathode. The products obtained at the constant cell voltage electrolysis of 3.0 V for more than 4 h were stoichiometric NiAl. The energy consumption could be as low as 6.1 kWh (kg-NiAl){sup -1} based on the applied cell voltage and the consumed electrolysis charge. Furthermore, the NiAl powders were made into a dense rod by spark plasma sintering (SPS) technique. The corrosion behaviors of the NiAl rod in 0.5 mol L{sup -1} NaCl aqueous solution at room temperature were investigated by polarization curve and ac impedance measurements. It was found that the NiAl rod had satisfactory anti-corrosion ability in the solution.

  14. 钒电解液的制备及其电化学和热力学分析%Preparation,Thermodynamic and Electrochemical Properties of Vanadium Solution

    Institute of Scientific and Technical Information of China (English)

    吴雄伟; 李厦; 黄可龙; 丁正平; 姜志成; 刘素琴; 李晓刚

    2011-01-01

    The vanadium solution was prepared by heating the mixture of vanadium trioxide and vanadium pentoxide in sulfuric acid solution,which utilized the autocatalytic effect of vanadium with mixed valence,to intensify the dissolving of the mixture of vanadium trioxide and vanadium pentoxide.The formations of vanadium ions were theoretically determined.Moreover,negative ΔrGm and ΔrHm of the reactions were calculated by thermomechanical analysis.The reactions was proved to be a spontaneous process(ΔrGm0).The results were confirmed by the UV-Vis analysis for the formation of ions.Its electrochemical performance was characterized by cyclic voltammetry and charge-discharge.The results showed that the prepared vanadium solution had an excellent electrochemical behavior,which indicated that the method was suitable for the industrial application.Our work may serve as the theoretical basis for industrial production of the electrolyte of vanadium redox-flow batteries.%以冶金级V2O3和V2O5为原料,采用混合加热和自催化强化溶解相结合的方法制备钒电解液.通过热力学分析,从理论上计算并确定了V2O5和V2O3溶解过程中在硫酸溶液中的离子存在形式,从而计算了钒电解液VOSO4过程的吉布斯自由能变化?rGm,以及相应的反应生成焓?rHm.结果表明:反应为放热反应,且为自发过程(?rGm〈0).同时通过UV-Vis光谱对所制备的电解液存在形式进行表征,证实了理论分析的正确性;使用循环伏安和充放电对其电化学性能予以分析,所得钒电解液具有很好的电化学性能.

  15. Chemical preparation of crystalline, nonmolecular solids, including solution-liquid-solid (SLS) growth of semiconductor fibers and varied routes to nanocrystalline molybdenum disilicide

    Science.gov (United States)

    Trentler, Timothy John

    New methods for the preparation of crystalline, nonmolecular solids under milder conditions and/or with control of crystallite size or morphology were developed in two separate projects. In one project, polycrystalline 13-15 semiconductor fibers (dimensions 10-100 nm x 50-1000 nm) were grown by solution-based chemical methods. Crystal precursor species of the general formula (Rsb{x}InEHsb{x}rbracksb{n}, where E is a pnictide and R is an alkyl group, were prepared by the phosphinolysis or arsinolysis of alkylindanes in aromatic solvents. Thermal decomposition of these precursors in solution, which was catalyzed by various protic reagents (MeOH, PhSH, Etsb2NH, or PhCOsb2H), resulted in crystalline InE when In metal was present in the form of submicron droplets dispersed in the solvent. Crystallization was determined to occur (at the lowest temperatures reported for 13-15 semiconductors, liquid-solid (SLS) mechanism reminiscent of vapor-liquid-solid (VLS) growth of single-crystal whiskers. Some analogous reactions were investigated in which t-Busb3Ga was mixed with the alkylindane in order to prepare ternary alloys (Insb{x}Gasb{1-x}As). Product crystallinity and composition was dependent on, though not exclusively determined by, the indane/gallane ratio. Crystals with composition within the miscibility gap for this alloy system were grown. The focus of the other project was the preparation of nanocrystalline (crystallite dimensions NaK alloy in an ultrasonically agitated hydrocarbon solvent followed by thermal processing (900sp°C) under vacuum to eliminate byproduct salts. MoSisb2 crystallites averaging 20-50 nm were obtained. Solvent degradation during this process resulted in the incorporation of substantial carbonaceous impurity (believed to be SiC) in these products. To eliminate the carbon, similar solventless reductions (without ultrasound) were conducted in molten magnesium, but average particle sizes have not been refined into the nanometer regime (currently

  16. Synthesis, sintering and dissolution of thorium and uranium (IV) mixed oxide solid solutions: influence of the method of precursor preparation; Synthese, frittage et caracterisation de solutions solides d'oxydes mixtes de thorium et d'uranium (IV): influence de la methode de preparation du precurseur

    Energy Technology Data Exchange (ETDEWEB)

    Hingant, N

    2008-12-15

    Mixed actinide dioxides are currently considered as potential fuels for the third and fourth generations of nuclear reactors. In this context, thorium-uranium (IV) dioxide solid solutions were studied as model compounds to underline the influence of the method of preparation on their physico-chemical properties. Two methods of synthesis, both based on the initial precipitation of oxalate precursors have been developed. The first consisted in the direct precipitation ('open' system) while the second involved hydrothermal conditions ('closed' system). The second method led to a significant improvement in the crystallization of the samples especially in the field of the increase of the grain size. In these conditions, the formation of a complete solid solution Th{sub 1-x}U{sub x}(C{sub 2}O{sub 4}){sub 2}.2H{sub 2}O was prepared between both end-members. Its crystal structure was also resolved. Whatever the initial method considered, these compounds led to the final dioxides after heating above 400 C. The various steps associated to this transformation, involving the dehydration of precursors then the decomposition of oxalate groups have been clarified. Moreover, the use of wet chemistry methods allowed to reduce the sintering temperature of the final thorium-uranium (IV) dioxide solid solutions. Whatever the method of preparation considered, dense samples (95% to 97% of the calculated value) were obtained after only 3 hours of heating at 1500 C. Additionally, the use of hydrothermal conditions significantly increased the grain size, leading to the reduction of the occurrence of the grain boundaries and of the global residual porosity. The significant improvement in the homogeneity of cations distribution in the samples was also highlighted. Finally, the chemical durability of thorium-uranium (IV) dioxide solid solutions was evaluated through the development of leaching tests in nitric acid. The optimized homogeneity especially in terms of the

  17. 长牡蛎肉小肽营养液的研制%The Preparation of Small Peptides Nutrient Solution by Enzymatic Method from Ostrea Gigas Thunberg Meat

    Institute of Scientific and Technical Information of China (English)

    方富永; 芦志刚; 苗艳丽; 胡世伟; 黄勇; 宋文东

    2012-01-01

    To study the technological conditions of small peptides nutrient solution preparation from Ostrea gigas Thunberg meat, first .Taking the hydrolyzing degree as the target to determine the optimum conditions of Ostrea gigas Thunberg meat hydrolyzed respectively by neutral protease, papain and bromelain. Based on orthogonal test, the best technological conditions hydrolyzed respectively by single protease were confirmed; and then three enzymes composite enzyme hydrolysis tests were proceeded.on the basis of hydrolyzing degree,the perfect match and the best technological conditions of enzyme hydrolysis were confirmed. On these grounds, the enzyme hydrolysate of Ostrea gigas Thunberg meat was prepared. Finally, small peptides nutrient solution was made from the enzyme hydrolysate under the condition of optimum formula confirmed by the orthogonal test.the composite hydrolyzing degree of Ostrea gigas Thunberg meat hydrolyzed by three protease can reach 52.97% under the optimum technological conditions, The peak value of relative molecular mass of these small peptide varied from 300 to 1 000 determined by polyacrylamide gradient gel vertical flatbed electrophoresis. The content of 17 free amino acids was 500.16 mg/100 mL. The optimum formula of small peptides nutrient solution.: hydrolysate (mL) : sucrose (g) :citric acid (g):sodium chloride (g)in proper sequence were as follow 100∶10∶ 0.2∶0.2. The total amount of free amino acids ≥5 000 mg/L. The nutritious liquid with eutrophy and simple preparation technology can be be applied to the high-priced exploitation of Ostrea gigas Thunberg meat.%研究长牡蛎肉小肽营养液制备的工艺条件.先以水解度为指标,确定长牡蛎肉中性蛋白酶、木瓜蛋白酶、菠萝蛋白酶单酶的最适水解条件,通过正交试验确定各单酶水解的最佳工艺条件;然后以此为基础进行三酶复合试验,根据水解度确定最佳工艺条件,制备长牡蛎肉水解液;最后以该水解液

  18. Nanocrystalline Fe{sub 1-x}Co{sub x}Sn{sub 2} solid solutions prepared by reduction of salts in tetraethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Nwokeke, Uche G. [Laboratorio de Quimica Inorganica, Universidad de Cordoba, Edificio C3, Campus de Rabanales, 14071 Cordoba (Spain); Chadwick, Alan V. [Functional Materials Group, School of Physical Sciences, University of Kent, Canterbury, Kent CT2 7NH (United Kingdom); Alcantara, Ricardo [Laboratorio de Quimica Inorganica, Universidad de Cordoba, Edificio C3, Campus de Rabanales, 14071 Cordoba (Spain); Alfredsson, Maria [Functional Materials Group, School of Physical Sciences, University of Kent, Canterbury, Kent CT2 7NH (United Kingdom); Tirado, Jose L., E-mail: iq1ticoj@uco.es [Laboratorio de Quimica Inorganica, Universidad de Cordoba, Edificio C3, Campus de Rabanales, 14071 Cordoba (Spain)

    2011-02-10

    Research highlights: > New nanoparticulate materials in the ternary system Fe{sub 1-x}Co{sub x}Sn{sub 2} are reported. > The electrochemical behaviour of the intermediate nano-Fe{sub 1-x}Co{sub x}Sn{sub 2} compositions is better than the corresponding micro-CoSn{sub 2} and FeSn{sub 2}. > The samples that contain iron form Li{sub x}Sn phases during the discharge of the cell and exhibit capacities over 500 mAh g{sup -1} during the first 30 cycles. > The partial replacement of cobalt by iron could moderate the potential cost and toxicity of the materials in Li-ion batteries. - Abstract: In an effort to improve the electrochemical performance of tin intermetallic phases as electrode active material for lithium-ion batteries, Fe{sub 1-x}Co{sub x}Sn{sub 2} solid solutions with x = 0.0, 0.25, 0.3, 0.5, 0.6 and 0.8 were prepared by chemical reduction in tetraethylene glycol. Precise control of the synthesis conditions allowed single-phase nanocrystalline materials to be prepared, with particle diameters of about 20 nm and cubic, nanorods, and U-shaped morphologies. The substitution of iron by cobalt induced a contraction of the unit cell volume. The hyperfine parameters of the {sup 57}Fe Moessbauer spectra were sensitive to the Co/Fe substitution and revealed a superparamagnetic behaviour. In lithium cells nanocrystalline Fe{sub 1-x}Co{sub x}Sn{sub 2} active materials delivered reversible capacities above 500 mAh g{sup -1} that depended on the composition and cycling conditions. The intermediate compositions exhibit better electrochemical performance than the end compositions CoSn{sub 2} and FeSn{sub 2}.

  19. Adsorption of Reactive Red 2 from aqueous solutions using Fe{sub 3}O{sub 4} nanoparticles prepared by co-precipitation in a rotating packed bed

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chia-Chang, E-mail: higee@mail.cgu.edu.tw [Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan, Taiwan, ROC (China); Lin, Yu-Shung [Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan, Taiwan, ROC (China); Ho, Jui-Min [Graduate Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan, Taiwan, ROC (China)

    2016-05-05

    A rotating packed bed (RPB) that was operated at a rotating speed of 1800 rpm with liquid flow rates of 0.5 L/min was used to prepare Fe{sub 3}O{sub 4} nanoparticles (RPB-Fe{sub 3}O{sub 4}). The RPB-Fe{sub 3}O{sub 4} had a smaller average size and a narrower size distribution than the Fe{sub 3}O{sub 4} that was obtained from Aldrich, and so had a greater capacity to adsorb RR2. The effects of pH, Fe{sub 3}O{sub 4} dosage, initial RR2 concentration, and temperature on the adsorption of RR2 were examined experimentally using RPB-Fe{sub 3}O{sub 4}. A thermodynamic study revealed that the adsorption process was spontaneous and exothermic. The adsorption behavior was more consistent with the Langmuir model than with the Freundlich model, and the maximum adsorption capacity was 97.8 mg/g. At pH 3, 25 °C, an Fe{sub 3}O{sub 4} dosage of 0.30 g/L, and an initial RR2 concentration of 10 mg/L, RPB-Fe{sub 3}O{sub 4} effectively adsorbed RR2 with a removal efficiency of approximately 95% in 10 min. These promising results clearly reveal the potential of RPB-Fe{sub 3}O{sub 4} for use in the effective removal of dyes from aqueous solutions. - Highlights: • A novel magnetic adsorbent (Fe{sub 3}O{sub 4} nanoparticles) was prepared in RPB. • 95% removal of RR2 was achieved in 10 min using Fe{sub 3}O{sub 4} nanoparticles. • This investigation provides a novel treatment of dye-contaminated wastewater.

  20. Effect of fuels on conductivity, dielectric and humidity sensing properties of ZrO2 nanocrystals prepared by low temperature solution combustion method

    Directory of Open Access Journals (Sweden)

    H.C. Madhusudhana

    2016-09-01

    Full Text Available ZrO2 nanopowders were synthesized by low temperature solution combustion method using two different fuels namely glycine and oxalyldihydrazide (ODH. The phase confirmation was done by powder X-ray diffraction (PXRD and Raman spectral analysis. Use of glycine resulted in ZrO2 with mixture of tetragonal and monoclinic phase with average crystallite size of ∼30 nm. However, ODH as fuel aids in the formation of ZrO2 with mixture of tetragonal and cubic phase with average crystallite size ∼20 nm. Further, in present work we present novel way to tune conductivity property of the nano ZrO2. We show that merely changing the fuel from glycine to ODH, we obtain better DC conductivity and dielectric constant. On the other hand use of glycine leads to the formation of ZrO2 with better AC conductivity and humidity sensing behavior. The dielectric constants calculated for samples prepared with glycine and ODH were found to be 45 and 26 respectively at 10 MHz. The AC and DC conductivity values of the samples prepared with glycine was found to be 9.5 × 10−4 S cm−1, 1.1 × 10−3 S cm−1 and that of ODH was 7.6 × 10−4 S cm−1, 3.6 × 10−3 S cm−1 respectively.

  1. [Preparation of a levodopa/carbidopa solution in ascorbic acid (citridopa) and chromatographic and electrochemical assessment of its stability over 24 hours].

    Science.gov (United States)

    López Lozano, J J; Moreno Cano, R

    1995-04-01

    Levodopa/inhibitor improves motor function in parkinsonian patients. In its usual tablet form, however, its efficacy is reduced after several years, partially due to absorption deficiencies and changes in plasma kinetics; thus, other therapeutic strategies to provide a stable, easy to prepare formula are being sought. One such approach could be to dissolve L-dopa/carbidopa in ascorbic acid. This report describes the preparation method and demonstrates the stability of the sample using High pressure liquid cromatography (HPLC) with electrochemical detection. Regardless of the number of tablets the patient takes, the concentration of L-dopa/carbidopa/ascorbic acid remains constant (1/0.25/2 mg/ml). Thus, a patient taking 5 tablets of Sinemet Plus a day, would pulverize them in a glass, ceramic or marble mortar and add them to a measuring cup containing a 1 gram tablet of vitamin C (Redoxon) dissolved in 500 cc of cold water. This would be shaken or stirred until the Sinemet powder had dissolved. A few particles remaining in suspension after this process would be of no concern. The liquid would be stored in the refrigerator in an opaque or aluminum foil-covered glass bottle or, if possible, in several small dose-size vials. Using a measuring cup, a test tube and a syringe, the correct volume can be drawn out of the bottle and shaken well before drinking. The solution would be taken at regular intervals throughout the day (which vary from one patient to another) to maintain stable plasma L-dopa levels.

  2. CdSiO{sub 3}:Eu{sup 3+} red nanophosphors prepared by low temperature solution combustion technique, its structural and luminescent properties

    Energy Technology Data Exchange (ETDEWEB)

    Nagabhushana, H., E-mail: bhushanvlc@gmail.com [Prof. C.N.R. Rao Centre for Advanced Materials Research, Tumkur University, Tumkur 572 103 (India); Sunitha, D.V. [Prof. C.N.R. Rao Centre for Advanced Materials Research, Tumkur University, Tumkur 572 103 (India); Sharma, S.C. [Chattisgarh Swami Vivekananda Technical University, Bhilai, CG 493441 (India); Prashantha, S.C., E-mail: scphysics@gmail.com [Research Center, Department of Science, East West Institute of Technology, Bangalore 560 091 (India); Nagabhushana, B.M. [Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054 (India); Chakradhar, R.P.S. [CSIR-National Aerospace Laboratories, Bangalore 560017 (India)

    2014-12-15

    Highlights: • CdSiO{sub 3}:Eu{sup 3+} phosphors were prepared by low temperature solution combustion technique for the first time. • XRD, SEM and FTIR techniques were used to characterize the phosphor. • Highest PL emission was recorded at 4 mol% of Eu{sup 3+} doped CdSiO{sub 3}. • Prepared phosphor can be effectively used for making the white LEDs. • The color purity has been verified by using the CIE diagram. - Abstract: CdSiO{sub 3}:Eu{sup 3+} (0.5–5 mol%) nanophosphors were synthesized using oxalyl di-hydrazide fuel by solution combustion technique for the first time{sub .} The structural, thermo and photoluminescent properties were studied. The average particle size was estimated from transmission electron microscopy (TEM) studies and found to be in the range 20–30 nm. The values were in good agreement with Scherer’s method and Williamson–Hall plots. Scanning electron microscope (SEM) showed highly porous, fluffy and many agglomerated particles. Photoluminescence (PL) CdSiO{sub 3}:Eu{sup 3+} (0.5–5 mol%) shows emission peaks at 577, 596, 612, 659 and 706 nm which were assigned to {sup 5}D{sub 0} → {sup 7}F{sub j} (j = 0, 1, 2, 3, 4) transition respectively. It was observed that PL intensity increases up to the concentration 4 mol% Eu{sup 3+}. Thermoluminescence (TL) studies were carried out on CdSiO{sub 3}:Eu{sup 3+} (1–5 mol%) nanophosphor by exposing to γ-rays (1–6 kGy) and UV (5–25 min) respectively. The TL intensity was found to be highest in 1 mol% Eu{sup 3+} concentration. Further, effect of different gamma (1–6 kGy) and UV (5–25 min) exposure was studied on CdSiO{sub 3}:Eu{sup 3+} nanophosphor. Simple well resolved glow peak at ∼178 °C was recorded for both the exposures. The TL intensity at 178 °C increase linearly with increase in the γ-dose. However, in UV exposed samples the TL glow peak intensity increase up to 10 min and thereafter the peak intensity decreases with further increase in exposure time. The effect

  3. Colorimetric Determination of the Iron(III)-Thiocyanate Reaction Equilibrium Constant with Calibration and Equilibrium Solutions Prepared in a Cuvette by Sequential Additions of One Reagent to the Other

    Science.gov (United States)

    Nyasulu, Frazier; Barlag, Rebecca

    2011-01-01

    The well-known colorimetric determination of the equilibrium constant of the iron(III-thiocyanate complex is simplified by preparing solutions in a cuvette. For the calibration plot, 0.10 mL increments of 0.00100 M KSCN are added to 4.00 mL of 0.200 M Fe(NO[subscript 3])[subscript 3], and for the equilibrium solutions, 0.50 mL increments of…

  4. Preparation of a diphosphine with persistent phosphinyl radical character in solution: characterization, reactivity with O2, S8, Se, Te, and P4, and electronic structure calculations.

    Science.gov (United States)

    Giffin, Nick A; Hendsbee, Arthur D; Roemmele, Tracey L; Lumsden, Michael D; Pye, Cory C; Masuda, Jason D

    2012-11-01

    A new, easily synthesized diphosphine based on a heterocyclic 1,3,2-diazaphospholidine framework has been prepared. Due to the large, sterically encumbering Dipp groups (Dipp = 2,6-diisopropylphenyl) on the heterocyclic ring, the diphosphine undergoes homolytic cleavage of the P-P bond in solution to form two phosphinyl radicals. The diphosphine has been reacted with O(2), S(8), Se, Te, and P(4), giving products that involve insertion of elements between the P-P bond to yield the related phosphinic acid anhydride, sulfide/disulfide, selenide, telluride, and a butterfly-type perphospha-bicyclobutadiene structure with a trans,trans-geometry. All molecules have been characterized by multinuclear NMR spectroscopy, elemental analysis, and single-crystal X-ray crystallography. Variable-temperature EPR spectroscopy was utilized to study the nature of the phosphinyl radical in solution. Electronic structure calculations were performed on a number of systems from the parent diphosphine [H(2)P](2) to amino-substituted [(H(2)N)(2)P](2) and cyclic amino-substituted [(H(2)C)(2)(NH)(2)P](2); then, bulky substituents (Ph or Dipp) were attached to the cyclic amino systems. Calculations on the isolated diphosphine at the B3LYP/6-31+G* level show that the homolytic cleavage of the P-P bond to form two phosphinyl radicals is favored over the diphosphine by ~11 kJ/mol. Furthermore, there is a significant amount of relaxation energy stored in the ligands (52.3 kJ/mol), providing a major driving force behind the homolytic cleavage of the central P-P bond.

  5. Kinetics and Thermodynamics of Cd(II Ions Sorption on Mixed Sorbents Prepared from Olive Stone and Date Pit from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    N. Babakhouya

    2010-01-01

    Full Text Available Problem statement: The aim of this study is to remove Cd(II ions from aqueous solutions by adsorption. Mixed sorbent prepared from olive stone and date pit, an agricultural solid by-product was used as adsorbent. Approach: The adsorption experiments of Cd(II onto the mixture of olive stone and date pit were conducted at different parameters such as, percent of olive stone and date pit in the mixture, temperature, initial solution pH and initial Cd(II concentration. Adsorption isotherms were obtained at different percent of olive stone and date pit in the mixture. Results: This adsorption data was fitted with the Langmuir. Kinetic studies revealed that the initial uptake was rapid and equilibrium was established in 20 min for all the studied metals and that the data followed the pseudo-second order reaction. The thermodynamic of Cadmium sorption on the mixed sorbent follows the Langmuir model and the sorption capacity for cadmium increases when we add a small amount of olive stone at date pits (90% of date pits in mixture and 10% of olive stone and a small amount of date pits at olive stone (90% of olive stone and 10% of date pits in mixture. In addition, the thermodynamic parameters, standard free energy (ÄG°, standard enthalpy (ÄH° and standard entropy (ÄS° of the adsorption process were calculated. The sorption of Cd(II onto the mixture of olive stones and dates pit is spontaneous and presents an endothermic nature. The characteristics of the mixture were determined by the analysis of infra red spectral analysis. Conclusion: The results show that the mixture sorbent from olive stone and date pit is an alternative low-cost adsorbent for removing Cd(II.

  6. A low cost preparation of VO{sub 2} thin films with improved thermochromic properties from a solution-based process

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lili [Key Laboratory of Renewable Energy and Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Miao, Lei, E-mail: miaolei@ms.giec.ac.cn [Key Laboratory of Renewable Energy and Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); Tanemura, Sakae, E-mail: fwhy7074@mb.infoweb.ne.jp [Key Laboratory of Renewable Energy and Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); Powder Technology PJ Lab., Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Japan Fine Ceramic Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587 (Japan); Zhou, Jianhua; Chen, Lihua; Xiao, Xiudi; Xu, Gang [Key Laboratory of Renewable Energy and Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2013-09-30

    This paper describes a solution-based route to synthesize vanadium dioxide (VO{sub 2}) thermochromic thin films on glass substrate by spin-coating technology followed by nitrogen-annealing with vanadium pentoxide (V{sub 2}O{sub 5}) and oxalic acid (H{sub 2}C{sub 2}O{sub 4}) as source material, which is fairly economical and practical. Surface morphologies indicate that the films obtained by this method are homogeneous and particulate, irregular prisms emerge as the annealing temperatures increase. X-ray diffractions show that films annealed at relatively low temperature are pure monoclinic phase with a preferred orientation of (011). NaV{sub 4}O{sub 7} and NaV{sub 6}O{sub 15} form along with raising the heating temperatures. VO{sub 2} films obtained exhibit excellent visible transparency and switching property at near-infrared wavelengths across the metal–semiconductor transition. Transmittance change at λ = 2000 nm of VO{sub 2} thin film annealed at 450 °C attains as high as 41.5% and its solar modulation efficiency reaches up to 8.8%. The W-doped VO{sub 2} film at a doping level of 1 at.% exhibits a thermochromic switch at 37 °C with a narrow hysteresis, which will greatly favor the practical application of VO{sub 2}-based smart windows. - Highlights: ► Vanadium dioxide thermochromic film was prepared via a solution-based deposition. ► Tungsten doping reduced the phase transition temperature to 37 °C. ► Tungsten doping narrowed the transmittance hysteresis loop. ► Our results will propel the application to vanadium dioxide-based smart windows.

  7. Photodegradation of indigo carmine and methylene blue dyes in aqueous solution by SiC-TiO{sub 2} catalysts prepared by sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Solis, Christian [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi Av. Manuel Nava 6, San Luis Potosi, S.L.P. 78290 (Mexico); Juarez-Ramirez, Isaias, E-mail: isajua13@yahoo.com [Departamento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Moctezuma, Edgar [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi Av. Manuel Nava 6, San Luis Potosi, S.L.P. 78290 (Mexico); Torres-Martinez, Leticia M. [Departamento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico)

    2012-05-30

    Highlights: Black-Right-Pointing-Pointer Photodegradation of organic dyes is possible using sol-gel SiC-TiO{sub 2} catalysts. Black-Right-Pointing-Pointer SiC-TiO{sub 2} makes a synergy effect that enhances its catalytic activity. Black-Right-Pointing-Pointer Sol-gel allows good dispersion and attachment of TiO{sub 2} particles on SiC surface. Black-Right-Pointing-Pointer SiC-TiO{sub 2} exhibits better activity than TiO{sub 2} (P25) on organic dyes degradation. Black-Right-Pointing-Pointer SiC-TiO{sub 2} catalysts are settled down and easily separated after photocatalysis. - Abstract: Indigo carmine and methylene blue dyes in aqueous solution were photodegraded using SiC-TiO{sub 2} catalysts prepared by sol-gel method. After thermal treatment at 450 Degree-Sign C, SiC-TiO{sub 2} catalysts prepared in this work showed the presence of SiC and TiO{sub 2} anatase phase. Those compounds showed specific surface area values around 22-25 m{sup 2} g{sup -1}, and energy band gap values close to 3.05 eV. In comparison with TiO{sub 2} (P25), SiC-TiO{sub 2} catalysts showed the highest activity for indigo carmine and methylene blue degradation, but this activity cannot be attributed to the properties above mentioned. Therefore, photocatalytic performance is due to the synergy effect between SiC and TiO{sub 2} particles caused by the sol-gel method used to prepare the SiC-TiO{sub 2} catalysts. TiO{sub 2} nanoparticles are well dispersed onto SiC surface allowing the transfer of electronic charges between SiC and TiO{sub 2} semiconductors, which avoid the fast recombination of the electron-hole pair during the photocatalytic process.

  8. Preparation of low cost activated carbon from Myrtus communis and pomegranate and their efficient application for removal of Congo red from aqueous solution.

    Science.gov (United States)

    Ghaedi, Mehrorang; Tavallali, Hossein; Sharifi, Mahdi; Kokhdan, Syamak Nasiri; Asghari, Alireza

    2012-02-01

    In this research, the potential applicability of activated carbon prepared from Myrtus communis (AC-MC) and pomegranate (AC-PG) as useful adsorbents for the removal of Congo red (CR) from aqueous solutions in batch method was investigated. The effects of pH, contact time, agitation time and amount of adsorbents on removal percentage of Congo red on both adsorbents were examined. Increase in pH up to 6 for AC-MC and pH 7 for AC-PG increase the adsorption percentage (capacity) and reach equilibrium within 30 min of contact time. Fitting the experimental data to conventional isotherm models like Freundlich, Langmuir, Tempkin and Dubinin-Radushkevich show that the experimental data fitted very well to the Freundlich isotherm for AC-MC and Langmuir isotherm for AC-PG. Fitting the experimental data to different kinetic models such as pseudo first-order, pseudo second-order, Elovich and intraparticle diffusion mechanism showed the applicability of a pseudo second-order with involvement of intraparticle diffusion model for interpretation of experimental data for both adsorbents. The adsorption capacity of AC-PG and AC-MC for the removal of CR was found to be 19.231 and 10 mg g(-1). These results clearly indicate the efficiency of adsorbents as a low cost adsorbent for treatment of wastewater containing CR.

  9. Preparation of low cost activated carbon from Myrtus communis and pomegranate and their efficient application for removal of Congo red from aqueous solution

    Science.gov (United States)

    Ghaedi, Mehrorang; Tavallali, Hossein; Sharifi, Mahdi; Kokhdan, Syamak Nasiri; Asghari, Alireza

    2012-02-01

    In this research, the potential applicability of activated carbon prepared from Myrtus communis (AC-MC) and pomegranate (AC-PG) as useful adsorbents for the removal of Congo red (CR) from aqueous solutions in batch method was investigated. The effects of pH, contact time, agitation time and amount of adsorbents on removal percentage of Congo red on both adsorbents were examined. Increase in pH up to 6 for AC-MC and pH 7 for AC-PG increase the adsorption percentage (capacity) and reach equilibrium within 30 min of contact time. Fitting the experimental data to conventional isotherm models like Freundlich, Langmuir, Tempkin and Dubinin-Radushkevich show that the experimental data fitted very well to the Freundlich isotherm for AC-MC and Langmuir isotherm for AC-PG. Fitting the experimental data to different kinetic models such as pseudo first-order, pseudo second-order, Elovich and intraparticle diffusion mechanism showed the applicability of a pseudo second-order with involvement of intraparticle diffusion model for interpretation of experimental data for both adsorbents. The adsorption capacity of AC-PG and AC-MC for the removal of CR was found to be 19.231 and 10 mg g -1. These results clearly indicate the efficiency of adsorbents as a low cost adsorbent for treatment of wastewater containing CR.

  10. Preparation of glass carbon electrode modified with nanocrystalline nickel-decorated carbon nanotubes and electrocatalytic oxidation of methanol in alkaline solution

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Nanocrystalline nickel with an average diameter of about 16 nm and a face-centered cubic (fcc)structure was uniformly attached to the surface of carbon nanotubes (CNT) by wet chemistry.The sample was characterized by X-ray powder diffraction and transmission electron microscopy (TEM).A glass carbon electrode modified with nickel-modified multi-wall carbon nanotubes (MWCNTs-Ni/GCE) was prepared.The electrochemical behavior of the MWCNTs-Ni/GCE and the electrocatalytic oxidation of methanol at the MWCNTsNi/GCE were investigated by cyclic voltammetry in 1.0 mol/L NaOH solution.The cyclic voltammograms showed that the electron transfer between β-Ni(OH)2 and β-NiOOH is mainly a diffusion-controlled quasireversible process,and that the electrode has high catalytic activity for the electrooxidation of methanol in alkaline medium,revealing its potential application in alkaline rechargeable batteries and fuel cells.

  11. Preparation and Characterization of Self-Reinforced Antibacterial and Oil-Resistant Paper Using a NaOH/Urea/ZnO Solution.

    Science.gov (United States)

    Jiao, Li; Ma, Jinxia; Dai, Hongqi

    2015-01-01

    This paper describes self-reinforced antibacterial and oil-resistant properties that were successfully prepared by surface selective dissolution of filter paper in a NaOH/Urea/ZnO (weight ratio of 8:12:0.25) aqueous solution. The effect of the processing time on the mechanical properties of this paper was evaluated at -12°C. The paper morphologies were characterized using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The oil-resistance and antibacterial properties of the produced paper were also investigated. Excellent mechanical properties were observed for an optimized handling time. The tensile and burst strengths of the modified paper were in excess of 100% of the original. Meanwhile, the treated paper was completely oil-resistant within 24 h and demonstrated good antibacterial properties when exposed to Staphylococcus aureus. The traces of residual zinc oxide were found to be safe for food.

  12. Preparation, characterization and adsorption properties of chitosan modified magnetic graphitized multi-walled carbon nanotubes for highly effective removal of a carcinogenic dye from aqueous solution

    Science.gov (United States)

    Zhu, HuaYue; Fu, YongQian; Jiang, Ru; Yao, Jun; Liu, Li; Chen, YanWen; Xiao, Ling; Zeng, GuangMing

    2013-11-01

    Novel chitosan-modified magnetic graphitized multi-walled carbon nanotubes (CS-m-GMCNTs) were synthesized via a suspension cross-linking method. Composition, morphology and magnetic properties of as-prepared CS-m-GMCNTs were characterized by XRD, SEM-EDS, BET and VSM. The large saturation magnetization (12.27 emu g-1) allows fast separation of CS-m-GMCNTs from treated aqueous solution. The adsorption of congo red (CR) on CS-m-GMCNTs was strongly dependent on pH, temperature of the aqueous phase and adsorbent dosage. Up to 100 and 94.58% color removal could be achieved in 100 min contact time with 10 and 50 mg L-1 of initial concentrations, respectively. The adsorption capacity of CR onto CS-m-GMCNTs could reach 262.9 mg g-1. The pseudo-second-order kinetic model with high correlation coefficients (R2 > 0.999) was suitable to describe the process of CR adsorption onto CS-m-GMCNTs. The Langmuir model fitted the adsorption isotherm data better than the Freundlich model. Values of thermodynamic parameters (ΔG°, ΔH° and ΔS°) indicated that the adsorption process was strongly dependent on temperature of the aqueous phase, and spontaneous and endothermic process in nature. Therefore, CS-m-GMCNTs adsorbent displays main advantages of excellent dispersion, convenience separation and high adsorption capacity, which implies their potential application in the environmental cleanup.

  13. Pyrolysis preparation of WO3 thin films using ammonium metatungstate DMF/water solution for efficient compact layers in planar perovskite solar cells

    Science.gov (United States)

    Jincheng, Zhang; Chengwu, Shi; Junjun, Chen; Chao, Ying; Ni, Wu; Mao, Wang

    2016-03-01

    The tungsten trioxide (WO3) thin films were firstly prepared by spin-coating-pyrolysis methods using the ammonium metatungstate ((NH4)6H2W12O40) DMF/water solution, and successfully applied as the efficient compact layers for the planar perovskite solar cells. The influence of the WO3 film thickness and the rinsing treatment of CH3NH3PbI3 thin film with isopropanol on the photovoltaic performance of the corresponding perovskite solar cells was systematically investigated. The results revealed that the perovskite solar cell with a 62 nm thick WO3 compact layer achieved a photoelectric conversion efficiency of 5.72%, with a short circuit photocurrent density of 17.39 mA/cm2, an open circuit voltage of 0.58 V and a fill factor of 0.57. The photoelectric conversion efficiency was improved from 5.72% to 7.04% by the isopropanol rinsing treatment. Project supported by the National Natural Science Foundation of China (Nos. 51472071, 512720616, 51072043), and the National Basic Research Program of China (No. 2011CBA00700).

  14. 磷酸铝铬耐磨材料的制备与研究%The Preparation and Research of Wearable Material with Chrome Aluminum Phosphate Solution

    Institute of Scientific and Technical Information of China (English)

    王珏; 刘洪成; 张晓臣

    2015-01-01

    针对煤粉、热力管道高温气体冲蚀及爆管问题,以氧化铝、氧化锆、二氧化硅和磷酸铝铬溶液为主要原料,制备了一种磷酸铝铬耐磨材料,测试其剪切性能、磨耗量并观察其微观形貌。结果表明:磷酸盐基耐磨材料的室温剪切强度为3.65MPa,磨耗量为0.30g/cm2。%A kind of wearable material was prepared using aluminum oxide, zirconium dioxide, silicon dioxide and chrome aluminum phosphate solution as the main raw material for the high temperature gas erosion and burst problem on the pipeline of pulverized coal and heat power. Then we tested its shearing strength, abrasion loss and observed the microstructure. The results showed that its shear strength at room temperature was 3.65MPa, the abrasion loss was 0.30g/cm2.

  15. 氧化镁铵盐法制备高纯过氧化镁%Preparation of High Purity Magnesium Peroxide by Magnesia and Ammonium Salt Solutions

    Institute of Scientific and Technical Information of China (English)

    朱海丽; 吴小王

    2011-01-01

    在氯化铵溶液体系中,以氧化镁,过氧化氢为原料,制备高纯过氧化镁。研究表明采用氧化镁活性大于100,氯化铵/氧化镁不小于10%,过氧化氢:氧化镁不小于4∶1,反应温度大于40℃情况下,反应时间不小于30 min,可制备出纯度大于90%的过氧化镁。%In ammonium chloride solution,magnesium oxide and hydrogen peroxide as raw material,high purity magnesium peroxide was prepared.The results showed that using magnesium oxide activity was greater than 100,ammonium chloride and magnesium oxide was not less than 10%,hydrogen peroxide to magnesium oxide was not less than 4:1,the reaction temperature was higher than 40 ℃,and the reaction time was not less than 30 min,with magnesium peroxide purity above 90%.

  16. Preparation, characterization and thermal behavior of K{sub 2}U{sub 4}O{sub 13}-Rb{sub 2}U{sub 4}O{sub 13} solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Kanrar, Buddhadev; Dhara, Sangita; Misra, Nand Lal [Bhabha Atomic Research Centre, Mumbai (India). Fuel Chemistry Div.

    2016-07-01

    The preparation and characterization of (K{sub 1-x}Rb{sub x}){sub 2}U{sub 4}O{sub 13} solid solutions has been studied for the x values in the range of 0 - 1. The solid solutions were prepared by heating K{sub 2}U{sub 4}O{sub 13} and Rb{sub 2}U{sub 4}O{sub 13} in required stoichiometry at about 600-700 C for about 50 h in air atmosphere. The XRD patterns of the products suggest formation of the solid solutions in full composition range of Rb{sub 2}U{sub 4}O{sub 13} and K{sub 2}U{sub 4}O{sub 13}. The cell volume of the crystal unit cell of solid solutions changes linearly with Rb atom % in (Rb + K) present in the solid solutions and follows Vegard's law. The solid solutions when heated in Ar/He atmospheres at 900 C produce corresponding low valent uranate solid solutions (K{sub 1-x}Rb{sub x}){sub 2}U{sub 4}O{sub 12} or their mixtures.

  17. On the Interaction between Co- and Mo-complexes in impregnation solutions used for the preparation of Al2O3-supported HDS catalysts: a combined Raman/UV-Vis-NIR spectroscopy study

    NARCIS (Netherlands)

    Bergwerff, J.A.; Visser, T.; Weckhuysen, B.M.

    2008-01-01

    Research has been carried out on the formation of cobalt (Co) and molybdenum (Mo) complexes in CoMo-solutions, which are used for the preparation of Al2O3-supported hydrodesulphurization (HDS) catalysts. Aim of this study was to obtain more insight into possible Co–Mo interactions and their implicat

  18. Nylon 6,6 Nonwoven Fabric Separates Oil Contaminates from Oil-in-Water Emulsions.

    Directory of Open Access Journals (Sweden)

    Ryan A Ortega

    Full Text Available Industrial oil spills into aquatic environments can have catastrophic environmental effects. First responders to oil spills along the coast of the Gulf of Mexico in the southern United States have used spunbond nylon fabric bags and fences to separate spilled oil and oil waste from contaminated water. Low area mass density spunbond nylon is capable of sorbing more than 16 times its mass in low viscosity crude oil and more than 26 times its mass in higher viscosity gear lube oil. Nylon bags separated more than 95% of gear lube oil contaminate from a 4.5% oil-in-water emulsion. Field testing of spunbond nylon fences by oil spill first responders has demonstrated the ability of this material to contain the oily contaminate while allowing water to flow through. We hypothesize that the effectiveness of nylon as an oil filter is due to the fact that it is both more oleophilic and more hydrophilic than other commonly used oil separation materials. The nylon traps oil droplets within the fabric or on the surface, while water droplets are free to flow through the fabric to the water on the opposite side of the fabric.

  19. Nylon 6,6 Nonwoven Fabric Separates Oil Contaminates from Oil-in-Water Emulsions

    Science.gov (United States)

    Carter, Erin S.; Ortega, Albert E.

    2016-01-01

    Industrial oil spills into aquatic environments can have catastrophic environmental effects. First responders to oil spills along the coast of the Gulf of Mexico in the southern United States have used spunbond nylon fabric bags and fences to separate spilled oil and oil waste from contaminated water. Low area mass density spunbond nylon is capable of sorbing more than 16 times its mass in low viscosity crude oil and more than 26 times its mass in higher viscosity gear lube oil. Nylon bags separated more than 95% of gear lube oil contaminate from a 4.5% oil-in-water emulsion. Field testing of spunbond nylon fences by oil spill first responders has demonstrated the ability of this material to contain the oily contaminate while allowing water to flow through. We hypothesize that the effectiveness of nylon as an oil filter is due to the fact that it is both more oleophilic and more hydrophilic than other commonly used oil separation materials. The nylon traps oil droplets within the fabric or on the surface, while water droplets are free to flow through the fabric to the water on the opposite side of the fabric. PMID:27411088

  20. A meta-analysis of randomized controlled trials of low-volume polyethylene glycol plus ascorbic acid versus standard-volume polyethylene glycol solution as bowel preparations for colonoscopy.

    Directory of Open Access Journals (Sweden)

    Qingsong Xie

    Full Text Available BACKGROUND: Standard-volume polyethylene glycol (PEG gut lavage solutions are safe and effective, but they require the consumption of large volumes of fluid. A new lower-volume solution of PEG plus ascorbic acid has been used recently as a preparation for colonoscopy. AIM: A meta-analysis was performed to compare the performance of low-volume PEG plus ascorbic acid with standard-volume PEG as bowel preparation for colonoscopy. STUDY: Electronic and manual searches were performed to identify randomized controlled trials (RCTs that compared the performance of low-volume PEG plus ascorbic acid with standard-volume PEG as bowel preparation for colonoscopy. After a methodological quality assessment and data extraction, the pooled estimates of bowel preparation efficacy during bowel cleansing, compliance with preparation, willingness to repeat the same preparation, and the side effects were calculated. We calculated pooled estimates of odds ratios (OR by fixed- and/or random-effects models. We also assessed heterogeneity among studies and the publication bias. RESULTS: Eleven RCTs were identified for analysis. The pooled OR for preparation efficacy during bowel cleansing and for compliance with preparation for low-volume PEG plus ascorbic acid were 1.08 (95% CI = 0.98-1.28, P = 0.34 and 2.23 (95% CI = 1.67-2.98, P<0.00001, respectively, compared with those for standard-volume PEG. The side effects of vomiting and nausea for low-volume PEG plus ascorbic acid were reduced relative to standard-volume PEG. There was no significant publication bias, according to a funnel plot. CONCLUSIONS: Low-volume PEG plus ascorbic acid gut lavage achieved non-inferior efficacy for bowel cleansing, is more acceptable to patients, and has fewer side effects than standard-volume PEG as a bowel preparation method for colonoscopy.

  1. Cellulose aerogels prepared from cellulose/AmimCl solutions%以纤维素/AmimCl溶液制备纤维素气凝胶

    Institute of Scientific and Technical Information of China (English)

    吕玉霞; 李小艳; 米勤勇; 王德修; 余坚; 张军

    2011-01-01

    利用离子液体AmimC1溶解结合超临界CO2干燥的方法制备了纤维素气凝胶材料.研究了不同初始浓度的纤维素溶液及其在不同凝固浴中制备的纤维素凝胶的流变行为,进一步考察了纤维素溶液浓度和凝固浴种类对纤维素气凝胶材料结构的影响.结果表明,随着初始纤维素溶液浓度的增大,气凝胶的孔结构逐渐致密,比表面积随之减小;凝固浴的组成对纤维素气凝胶的结构也有较大影响.采用适当的制备条件,可以制备出高比表面积的纤维素气凝胶材料.对纤维素气凝胶的热性能进行了表征,结果表明所得到的气凝胶材料具有较好的热稳定性和较高的炭残余含量.%Cellulose aerogel materials were prepared by combining dissolving cellulose in an ionic liquid, 1-allyl-3-methylimidazolium chloride (AmimCl), and drying in supercritical CO2. The rheological properties of the cellulose solutions of different concentrations and their gels regenerated in different coagulation baths were studied. The porous structure and morphology of cellulose aerogels were found to be affected by cellulose concentration and nature of the coagulation bath. With increasing initial cellulose concentration, the porous structure of cellulose aerogels became more dense and uniform, leading to the gradual decrease of the specific surface area. Further, it was also observed that, both viscosity and the polarity of coagulation bath affected the structure of cellulose aerogels. High specific surface area cellulose aerogel materials could be prepared by controlling the experimental conditions. The obtained cellulose aerogels had relatively high char yield at elevated temperature, which makes them potential precursors for fabrication of novel mesoporous carbon materials.

  2. The loading effect of silver nanoparticles prepared by impregnation and solution plasma methods on the photocatalysis of Ga{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Muneaki, E-mail: yamamoto.muneaki@f.mbox.nagoya-u.ac.jp [Department of Materials, Physics and Energy Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Yoshida, Tomoko, E-mail: tyoshida@nucl.nagoya-u.ac.jp [EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Yamamoto, Naoto [Department of Materials, Physics and Energy Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Nomoto, Toyokazu [Aichi Synchrotron Radiation Center, 250-3, Minamiyamaguchi-cho, Seto 489-0965 (Japan); Yagi, Shinya [EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2015-09-15

    Ag loaded Ga{sub 2}O{sub 3} (Ag/Ga{sub 2}O{sub 3}) photocatalysts for the reduction of CO{sub 2} with water have been prepared by impregnation (IMP) and two types of solution plasma methods (SPM1 and SPM2). Using X-ray absorption near edge structure (XANES) and Fourier transform infrared (FT-IR) spectroscopies, we have investigated the local electronic structures of Ag/Ga{sub 2}O{sub 3} photocatalysts as well as the adsorption behaviors of CO{sub 2} during the reaction. Both Ag L{sub 3}-edge and O K-edge XANES analyses reveal the Ag–Ga{sub 2}O{sub 3} interaction, i.e., the charge-transfer from O atoms to Ag atoms, by demonstrating the decrease in the unoccupied Ag 4d-state density and increase in the unoccupied O 2p-state density. The strength of the interaction depends on the preparation method, and increases in the order of Ag/Ga{sub 2}O{sub 3} (SPM2), Ag/Ga{sub 2}O{sub 3} (SPM1) and Ag/Ga{sub 2}O{sub 3} (IMP). In addition, FT-IR measurements have disclosed that Ag/Ga{sub 2}O{sub 3} (IMP) obtains a larger amount of strongly basic sites as a result of the strongest interaction between Ag and Ga{sub 2}O{sub 3}. Although the amount of the adsorbed CO{sub 2} is different in each Ag/Ga{sub 2}O{sub 3} sample, in the following formation process of bidentate formate species, no remarkable difference is detected among all samples. The bidentate formate species are likely to interact with H{sub 2}O molecules to produce CO under photoirradiation, and this process would be affected by the strength of the Ag–Ga{sub 2}O{sub 3} interaction, because this reaction hardly proceeds over Ag/Ga{sub 2}O{sub 3} (SPM2) having the weakest Ag–Ga{sub 2}O{sub 3} interaction.

  3. 水杨酸氯霉素醇溶液的质量控制%Quality control of preparation of salicylic acid and chloramphenicol alcoholic solution

    Institute of Scientific and Technical Information of China (English)

    赵子瑞; 张迅; 张佳莉; 董敏; 李云兰

    2013-01-01

    目的 建立水杨酸氯霉素醇溶液的质量控制方法.方法 采用酸碱滴定法测定水杨酸的含量,化学法鉴别其中的水杨酸和氯霉素,装量差异应符合涂剂项下有关的各项规定.结果 3批样品化学鉴别均呈阳性反应,阴性对照不干扰测定.水杨酸含量测定线性范围为80.0~402.5 mg,回归方程为=15.0803x+1.2704,r=0.9996,平均回收率为99.6%,RSD为0.4%(n=6).结论 本法简便灵敏,重复性好,专属性强,能有效控制水杨酸氯霉素醇溶液的质量.%Objective To establish a methodology for quality control of preparation of salicylic acid and chloramphenicol alcoholic solution. Methods The acid-base titration was employed to determine the content of salicylic acid, and miscellaneous chemical methods were applied to identify salicylic acid and chloramphenicol. The difference in volume conformed to relevant regulations. Results The three batches of samples tested positively without interference on the negative control. Determination of salicylic acid yielded a linear range of 80~402.5 mg, the regression e-quation of y=15.0803χ+1.2704 (r=0.9996), with the average recovery of 99.6% and RSD of 0.4% (n=6). Conclusion Owing to high sensitivity repeatability and specificity, the aforementioned methodology may effectively secure the quality of salicylic acid and chloramphenicol alcoholic solution.

  4. Enhancement of photoinduced electrical properties of Al-doped ZnO/BiFeO3 layered thin films prepared by chemical solution deposition

    Science.gov (United States)

    Katayama, Takeshi; Sakamoto, Wataru; Yuitoo, Isamu; Takeuchi, Teruaki; Hayashi, Koichiro; Yogo, Toshinobu

    2015-10-01

    Polycrystalline BiFeO3 and Al-doped ZnO/BiFeO3 bilayered thin films were prepared on Pt/TiOx/SiO2/Si substrates by chemical solution deposition. Their photoinduced electrical properties under blue light irradiation were characterized. The rapid on/off response of the photocurrent to light in unpoled BiFeO3 (BFO) and Al-doped ZnO/BiFeO3 (AZO/BFO) thin films was demonstrated. The AZO/BFO layered film exhibited an approximately triple-digit larger photocurrent in comparison with a BFO single-layer film. This is attributable to the photoexcited carrier generation effect at the interface between AZO (n-type) and BFO (p-type) films. Furthermore, in the AZO/BFO layered structure, the direction of the internal bias electric field caused by the space charge distribution in the unpoled BFO film is the same as that of the built-in electric field by forming a p-n junction of AZO and BFO layers. Photovoltaic properties were also improved by fabricating such a layered film. On the other hand, when the placement of BFO to AZO was reversed, the photoelectric current decreased to approximately one-tenth of that of the BFO single-layer film. In the BFO/AZO film, the internal electric field at the p-n junction between BFO and AZO is considered to have an orientation opposite to the self-bias field formed in the BFO film.

  5. N-doped P25 TiO2-amorphous Al2O3 composites: one-step solution combustion preparation and enhanced visible-light photocatalytic activity.

    Science.gov (United States)

    Li, Fa-tang; Zhao, Ye; Hao, Ying-juan; Wang, Xiao-jing; Liu, Rui-hong; Zhao, Di-shun; Chen, Dai-mei

    2012-11-15

    Nitrogen-doped Degussa P25 TiO2-amorphous Al2O3 composites were prepared via facile solution combustion. The composites were characterised using X-ray diffraction, high-resolution transmission microscopy, scanning electron microscopy, nitrogen adsorption-desorption measurements, X-ray photoelectron spectroscopy, UV-vis light-diffusion reflectance spectrometry (DRS), zeta-potential measurements, and photoluminescence spectroscopy. The DRS results showed that TiO2 and amorphous Al2O3 exhibited absorption in the UV region. However, the Al2O3/TiO2 composite exhibited visible-light absorption, which was attributed to N-doping during high-temperature combustion and to alterations in the electronic structure of Ti species induced by the addition of Al. The optimal molar ratio of TiO2 to Al2O3 was 1.5:1, and this composite exhibited a large specific surface area of 152 m2/g, surface positive charges, and enhanced photocatalytic activity. These characteristics enhanced the degradation rate of anionic methylene orange, which was 43.6 times greater than that of pure P25 TiO2. The high visible-light photocatalytic activity was attributed to synthetic effects between amorphous Al2O3 and TiO2, low recombination efficiency of photo-excited electrons and holes, N-doping, and a large specific surface area. Experiments that involved radical scavengers indicated that OH and O2- were the main reactive species. A potential photocatalytic mechanism was also proposed.

  6. Properties of Ba(Mg1/3Ta2/3)O3 thin films prepared by metalorganic solution deposition technique for microwave applications

    Science.gov (United States)

    Joshi, P. C.; Desu, S. B.

    1998-08-01

    We report on the properties of Ba(Mg1/3Ta2/3)O3 thin films prepared by the metalorganic solution deposition technique. Bulk Ba(Mg1/3Ta2/3)O3 ceramics have shown excellent dielectric properties at microwave frequencies; however, the high sintering temperature of bulk material is the major obstacle in their use as dielectric resonators to miniaturize microwave circuits. It was possible to obtain an ordered-perovskite phase of 0.3-μm-thick Ba(Mg1/3Ta2/3)O3 films with trigonal symmetry at an annealing temperature of 700 °C, which is much lower than the bulk sintering temperatures. The electrical measurements were conducted on Pt/Ba(Mg1/3Ta2/3)O3/Pt capacitors. The typical measured small signal dielectric constant and dissipation factor at 100 kHz were 22.2 and 0.009, respectively. The dielectric constant of thin films was comparable to the typical values (ɛr˜23.5-25) reported for bulk ceramics. The temperature coefficient of capacitance was -145 ppm/°C in the measured temperature range of 25-125 °C. The leakage current density was lower than 10-7 A/cm2 at an applied electric field of 0.5 MV/cm. The high dielectric constant, which is comparable to bulk, low dielectric loss, and good temperature and bias stability suggest the suitability of Ba(Mg1/3Ta2/3)O3 thin films for microwave communications and integrated capacitor applications.

  7. Preparation of α-calcium sulfate hemihydrat