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Sample records for pvc matrix membrane

  1. Effect of radiation on properties of ENR/PVC/SiO{sub 2} membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, Nur Farahein Hadina; Abdullah, Ibrahim; Daik, Rusli; Ahmad, Ishak; Jamil, Suzereen; Lazim, Mohammad Azwan Mat; Othaman, Rizafizah [School of Chemical Sciences and Food Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan. Malaysia (Malaysia)

    2015-09-25

    In this study epoxidised natural rubber (ENR)/polyvinyl chloride (PVC) matrix was prepared by melt blending. The matrix was swelled in THF and silica as a filler was introduced to the solution to generate pore formation. The ENR/PVC/10 % SiO{sub 2} membrane was prepared using a casting knife technique. The membrane was irradiated using 2 MeV electron beam accelerator at a dose range of 10-100 kGy. The effect of electron beam irradiation of the membrane was studied by undergo characterization of Scanning electron microscope (SEM) and Fourier transform infra red (FTIR). Morphological studies showed that pores generated in ENR/PVC/10 % SiO{sub 2} membrane increased with the dosage of radiation. While FTIR analysis showed the presence of peak of Si-O-Si asymmetric stretching at 834 cm{sup −1}. There are no significant changes in the functional group before and after radiation.

  2. Cyclic Voltammetry of Biopolymer Heparin at PVC Plasticized Liquid Membrane

    Czech Academy of Sciences Publication Activity Database

    Samec, Zdeněk; Trojánek, Antonín; Langmaier, Jan; Samcová, E.

    2003-01-01

    Roč. 5, - (2003), s. 867-870 ISSN 1388-2481 R&D Projects: GA ČR GA203/04/0424 Institutional research plan: CEZ:AV0Z4040901 Keywords : cyclic voltammetry * PVC plasticized liquit membrane * heparin Subject RIV: CG - Electrochemistry Impact factor: 2.300, year: 2003

  3. Comparative studies of neodymium (III)-selective PVC membrane sensors

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Vinod K., E-mail: vinodfcy@iitr.ernet.in [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667 (India); Goyal, Rajendra N.; Sharma, Ram A. [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667 (India)

    2009-08-04

    Sensors based on two neutral ionophores, N,N'-bis((1H-pyrrol-2-yl)methylene)cyclohexane-1,2-diamine (L{sub 1}) and 3,3'-(cyclohexane-1,2-diylbis(azan-1-yl-1-ylidene) bis(methan-1-yl-1-ylidene)bis(5-hydroxymethyl)pyridine-2-ol) (L{sub 2}) are described for quantification of neodymium (III). Effect of various plasticizers; 2-nitrophenyloctylether (o-NPOE), dibutyl butylphosphonate (DBBP), tri-n-butyl phosphates (TBP), dioctylpthalate (DOP) and chloronapthalen (CN) and anion excluder, sodiumtetraphenylborate (NaTPB) has been studied. The membrane composition of PVC:o-NPOE:ionophore (L{sub 1}):NaTPB (w/w; mg) of 150:300:5:5 exhibited best performance. The sensor with ionophore (L{sub 1}) exhibits significantly enhanced selectivity towards neodymium (III) in the concentration range 5.0 x 10{sup -7} to 1.0 x 10{sup -2} M with a detection limit of 1.0 x 10{sup -7} M and a Nernstian compliance (19.8 {+-} 0.3 mV decade{sup -1} of activity) within pH range 4.0-8.0. The response time of sensor was found as 10 s. The influence of the membrane composition and possible interfering ions has also been investigated on the response properties of the electrode. The fast and stable response, good reproducibility and long-term stability of the sensor are observed. The sensor has been found to work satisfactorily in partially non-aqueous media up to 20% (v/v) content of methanol, ethanol or acetonitrile and could be used for a period of 3 months. The selectivity coefficients determined by using fixed interference method (FIM) indicate high selectivity for neodymium. The proposed electrode shows fairly good discrimination of neodymium (III) from other cations. The application of prepared sensor has been demonstrated in the determination of neodymium (III) in spiked water samples.

  4. Effect of Modified Natural Rubber on PVC-ENR Electrospun Membrane: Thermal and Morphological Studies

    International Nuclear Information System (INIS)

    Mahathir Mohamed; Dahlan Mohd; Ratnam, C.T.; Pairu Ibrahim

    2016-01-01

    Electrospun fibers membrane (EFM) based on modified epoxidized natural rubber (ENR) and polyvinyl chloride (PVC) was successfully prepared by electro spinning technique. Epoxidized natural rubber was firstly prepared in solution by using 5 L flask and exposed to high intensity UV lamp for degradation. The PVC/ ENR mixture solution concentration were about 16 wt% and blended for 5 hours for homogeneity. The PVC/ ENR mixture were electro spun to form fibers membrane. The sample of electro spun fibers membrane were cured by electron beam. The resulting membranes were characterized for thermal and morphological studies. Thermal decomposition behavior of EFM was analyzed by thermogravimetric analysis (TGA). Thermo gram from TGA showed two stages of degradation for all formulation (90:10, 80:20, 70:30 PVC/ ENR) from 240 to 265 degree Celsius and 400 to 410 degree Celsius, respectively. From the DSC thermo gram of PVC/ ENR electro spun fibers showed that the addition of ENR resulted in the shifting of glass transition temperature (Tg) towards lower temperatures. The morphology of electro spun fibers was examined using scanning electron microscopy and it showed a variety of fiber morphologies. (author)

  5. PAN-Immobilized PVC-NPOE Membrane for Environmentally Friendly Sensing of Cd(II Ions

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    Moersilah Moersilah

    2017-04-01

    Full Text Available A simple, cheap and environmentally friendly analytical method of Cd(II in the aqueous system has been developed by immobilization of 1-(2-pyridilazo-2-naphtol (PAN in poly vinyl chloride (PVC matrix and nitrophenyl octyl ether (NPOE as a plasticizer. Upon contact with Cd(II in solution, the color of sensor membrane changes from dark yellow to dark red, which is due to the formation of Cd(II–PAN complex. The best sensing results were obtained at pH 8.0 and λmax 558 nm. The dimension of the proposed sensor membrane was 0.8 cm x 2 cm with a thickness of 0.05 mm, the volume of sample was 2 mL with the Cd(II concentration range of  0 – 1.2 ppm. The limit of detection of the method was found to be 0.432 + 0.104 ppm, which was reversible. The proposed methods have been applied in the determination of Cd(II in water samples after addition of internal standard.

  6. Charge Transfer Resistance and Differential Capacity of the Plasticized PVC Membrane/Water Interface

    Czech Academy of Sciences Publication Activity Database

    Langmaier, Jan; Stejskalová, Květoslava; Samec, Zdeněk

    2002-01-01

    Roč. 521, 1/2 (2002), s. 81-86 ISSN 0022-0728 R&D Projects: GA AV ČR IAA4040902 Institutional research plan: CEZ:AV0Z4040901 Keywords : impedance * PVC plasticized membrane * ion transfer kinetics Subject RIV: CG - Electrochemistry Impact factor: 2.027, year: 2002

  7. Evaluation of the Standard Ion Transfer Potentials for PVC Plasticized Membranes from Voltammetric Measurements

    Czech Academy of Sciences Publication Activity Database

    Langmaier, Jan; Stejskalová, Květoslava; Samec, Zdeněk

    2001-01-01

    Roč. 496, č. 1 (2001), s. 143-147 ISSN 0022-0728. [Symposium in Kyoto. Kyoto, 02.03.2000] R&D Projects: GA AV ČR IAA4040902 Institutional research plan: CEZ:AV0Z4040901 Keywords : ion voltammetry * PVC plasticized membrane * standard ion transfer potential Subject RIV: CG - Electrochemistry Impact factor: 1.960, year: 2001

  8. Functionalization of PVC membrane with ss oligonucleotides for a potentiometric biosensor.

    Science.gov (United States)

    Shishkanova, T V; Volf, R; Krondak, M; Král, V

    2007-05-15

    A novel application of a single stranded (ss) oligonucleotide as an active component of polymeric membrane in an ion-selective electrode (ISE) is described. The original oligonucleotides, oligo(dA)(15), modified by cholesterol, triphenylmethyl and hexadecyl derivatives, were immobilized into poly(vinyl chloride) (PVC) membrane using extraction protocol. In parallel, the adsorption protocol was used to immobilize unmodified oligo(dA)(15) on the PVC membrane based on tridodecylmethyammonium chloride (TDDMA(+)Cl(-)). Immobilization of ss oligonucleotide probe through spacer was more effective for the potentiometric detection of the hybridization between complementary oligonucleotides. It was found that cholesterol-oligo(dA)(15) modified membranes were sensitive toward complementary oligo(dT)(15) in the concentration range 2-80 nM at pH 7. An explanation for the detection mechanism is proposed.

  9. Comparative Study of PVC-Free All-Solid-State, PVC Membrane, and Carbon Paste Ion-Selective Electrodes for the Determination of Dapoxetine Hydrochloride in Pharmaceutical Formulation.

    Science.gov (United States)

    Aziz, Azza; Khamees, Nesrin; Mohamed, Tagreed Abdel-Fattah; Derar, Abeer Rashad

    2016-11-01

    The potentiometric response characteristics and analytical applications of a poly(vinyl chloride) (PVC)-free all-solid-state ion-selective electrode for dapoxetine hydrochloride (DAP) are examined. The Nernstian response of the electrode was evaluated by comparison with PVC-based liquid membrane and carbon paste electrodes. The PVC-free electrode is prepared by direct incorporation of dapoxetine-tetraphenyl borate (DAP-TPB) as a sensing element into a commercial nail varnish containing cellulose acetate propionate. The composite was applied onto a 3 mm diameter graphite disk electrode. The electrode exhibited a Nernstian slope of 56.0 mV/decade in the concentration range of 1 × 10-4 to 1 × 10-2 mol/L with an LOD of 2 × 10-5 mol/L. The electrode is independent of pH in the range of 2 to 6 and showed good selectivity for DAP with respect to a large number of inorganic cations and amino acids. Comparable Nernstian slope, sensitivity, pH range, and selectivity pattern were obtained with a PVC membrane and a carbon paste incorporating DAP-TPB as a sensing element and dioctylphthalate as a solvent mediator. The electrodes were used for the determination of DAP in pure solution and in tablets without extraction with high accuracy and precision (RSD ≤ 2%). The nail varnish solid-state electrode is simple, economical, and rapid when compared with PVC membrane and carbon paste electrodes.

  10. Study of microporous PVA/PVC composite polymer membrane and it application to MnO2 capacitors

    International Nuclear Information System (INIS)

    Yang, C.-C.; Wu, G.M.

    2009-01-01

    A microporous poly(vinyl alcohol)/poly(vinyl chloride) (PVA/PVC) composite polymer membrane was successfully synthesized by a solution casting method and a preferential dissolution method. The characteristic properties of PVA/PVC composite polymer membranes were systematically studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), micro-Raman spectroscopy and AC impedance spectroscopy. The PVA/PVC composite polymer membrane shows excellent thermal property, dimensional stability, and the ionic conductivity; it is due to the addition of secondary PVC polymer fillers. The MnO 2 capacitors with the PVA/PVC composite polymer membrane with 1 M Na 2 SO 4 was assembled and examined. It was found that the MnO 2 capacitor based on a microporous PVA/5 wt.%PVC composite polymer electrolyte membrane exhibited the maximum specific capacitance of 238 F g -1 and the current efficiency of 99% at 25 mV s -1 after 1000 cycle test. The result demonstrates that the novel microporous PVA/PVC composite polymer membrane is a potential candidate for use on the capacitors

  11. PVC membrane based potentiometric sensor for uranyl ion using thenoyl trifluoro acetone as ionophore

    International Nuclear Information System (INIS)

    Nanda, D.; Chouhan, H.P.S.; Maiti, B.

    2004-01-01

    Uranyl ion selective electrode based on thenoyl trifluoro acetone (TTA) incorporated into a polyvinyl chloride (PVC) membrane has been developed where dibutyl phthalate and sodium tetraphenyl borate have been used as plasticizer and anion excluder respectively. The PVC membrane containing the active ionophore, TTA, and the other ingredients has been directly cast a graphite electrode. The electrode shows near Nernstian response to UO 2 2+ in the concentration range of 10 -1 to 10 -6 mol. L -1 an average slope of 30 mV/decade. Alkali and alkaline earth ions do not interfere with the determination of uranyl ion. Interference of transition metal ions and Th (IV) is eliminated using EDTA. (author)

  12. Preparation of anion exchange membrane using polyvinyl chloride (PVC) for alkaline water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Gab-Jin; Bong, Soo-Yeon; Ryu, Cheol-Hwi [Hoseo University, Asan (Korea, Republic of); Lim, Soo-Gon [Energy and Machinery Korea Co., Ltd., Changwon (Korea, Republic of); Choi, Ho-Sang [Kyungil University, Gyeongsan (Korea, Republic of)

    2015-09-15

    An anion exchange membrane was prepared by the chloromethylation and the amination of polyvinyl chloride (PVC), as the base polymer. The membrane properties of the prepared anion exchange membrane, including ionic conductivity, ion exchange capacity, and water content were measured. The ionic conductivity of the prepared anion exchange membrane was in the range of 0.098x10{sup -2} -7.0x10{sup -2}S cm{sup -1}. The ranges of ion exchange capacity and water content were 1.9-3.7meq./g-dry-membrane and 35.1-63.1%, respectively. The chemical stability of the prepared anion exchange membrane was tested by soaking in 30 wt% KOH solution to determine its availability as a separator in the alkaline water electrolysis. The ionic conductivity during the chemical stability test largely did not change.

  13. PVC Membrane Sensors for Potentiometric Determination of Acebutolol

    Directory of Open Access Journals (Sweden)

    Abdulrahman Al-Majed

    2007-12-01

    Full Text Available The construction and general performance characteristics of two novelpotentiometric membrane sensors responsive to the acebutolol are described. Thesensors are based on the use of ion-association complexes of acebutolol (AC withtetraphenylborate(TPB (I and phosphomolybdate(PM (II as exchange sites in a PVCmatrix. The sensors show a fast, stable and near- Nernstian for the mono charge cationof AC over the concentration range 1×10-3 - ~10-6 M at 25 °C over the pH range 2.0 -6.0 with cationic slope of 51.5 ± 0.5 and 53.0 ± 0.5 per concentration decade for AC-Iand AC-II sensors respectively. The lower detection limit is 6×10-6 M and 4×0-6 M withthe response time 20-30 s in the same order of both sensors. Selectivity coefficients ofAC related to a number of interfering cation and some organic compounds wereinvestigated. There are negligible interferences are caused by most of the investigatedspecies. The direct determination of 3 - 370 μg/ml of AC shows an average recovery of 99.4 and 99.5% and a mean relative standard deviation of 1 . 5 % at 100.0 μg/ml forsensor I and II respectively. The results obtained by determination of AC in tablets usingthe proposed sensors which comparable favorably with those obtained by the Britishpharmacopoeia method. In the present investigation the electrodes have been utilized asend point indicator for some precipitation titration reactions.

  14. A novel EIS field effect structures coated with TESUD-PPy-PVC-dibromoaza[7]helicene matrix for potassium ions detection

    Energy Technology Data Exchange (ETDEWEB)

    Tounsi, Moncef, E-mail: tounsi1981@live.fr [Laboratoire des Interfaces et des Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Université de Monastir (Tunisia); Université de Lyon, Institut de Sciences Analytiques (ISA) – UMR 5280, 5 rue de la Doua, 69100 Villeurbanne (France); Ben Braiek, Mourad [Laboratoire de Synthèse Organique Asymétrique et Catalyse Homogène, Faculté des Sciences, Université de Monastir, Avenue de l' environnement, 5019, Monastir (Tunisia); Barhoumi, Houcine [Laboratoire des Interfaces et des Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Université de Monastir (Tunisia); Baraket, Abdoullatif; Lee, Michael; Zine, Nadia [Université de Lyon, Institut de Sciences Analytiques (ISA) – UMR 5280, 5 rue de la Doua, 69100 Villeurbanne (France); Maaref, Abderrazak [Laboratoire des Interfaces et des Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Université de Monastir (Tunisia); Errachid, Abdelhamid, E-mail: abdelhamid.errachid-el-salhi@univ-lyon1.fr [Université de Lyon, Institut de Sciences Analytiques (ISA) – UMR 5280, 5 rue de la Doua, 69100 Villeurbanne (France)

    2016-04-01

    In this work, we describe the development of new Aza[7]helicene-containing PVC-based membranes for the K{sup +} ions quantification. Here, silicon nitride-based structures (Si-p/SiO{sub 2}/Si{sub 3}N{sub 4}) were developed and the surface was activated, functionalized with an aldehyde–silane (11-(Triethoxysilyl)undecanal (TESUD)), functionalized with polypyrrole (PPy), and coated with the polyvinylchloride (PVC)-membrane containing the Aza[7]helicene as ionophore. All stages of functionalization process have been thoroughly studied by contact angle measurements (CAMs) and atomic force microscopy (AFM). The developed ion-selective electrode (ISE) was then applied using electrochemical impedance spectroscopy (EIS) for the detection of potassium ions. A linear range was observed between 1.0 × 10{sup −8} M to 1.0 × 10{sup −3} M and a detection limit of 1.0 × 10{sup −8} M was observed. The EIS results have showed a good sensitivity to potassium ion using this novel technique. The target helicene exhibited good solubility and excellent thermal stability with a high decomposition temperature (Td > 300 °C) and it indicates that helicene may be a promising material as ionophore for ion-selective electrodes (ISEs) elaboration. - Highlights: • Synthesis and characterization of a new derivatives of Aza[7]helicenes • Manufacture of PPy structures on the SiO{sub 2}/Si{sub 3}N{sub 4} surface using the TESUD as cross linking agent. • The PPy fabricated microstructures can be used as support matrix in biosensing. • Impedimetric K{sup +}-ISEs was developed by using dibromoaza[7]helicene as ionophore for K{sup +} ions determination.

  15. Development of pvc membrane based potentiometric pH sensor using amine type neutral carrier

    International Nuclear Information System (INIS)

    Khan, M.F.

    1999-01-01

    The glass membrane-based pH-electrode has proved its utility over decades. However some limitations are associated with these type of sensors. It can not be used for measuring pH of hydrofluoric acid solution and is difficult to miniaturize for biological applications due to its high resistance and fragility. In the present investigation modified PVC-membranes have been cast by incorporating lipophilic salt tetrabutyl ammonium tetraphenylborate and sodium tetraphenylborate along with electro active compound tri-n-octylamine as neutral carrier. The performance comparison of fabricated pH-sensitive membrane electrode has been carried out regarding their Nernstian slope and life time. The performance comparison of the membrane electrodes fabricated from laboratory grade tri-n-octylamine and those prepared from highly purified ionophore was also carried out. The slopes of the modified membrane electrodes based on pure ionophore were 59 mV/decade H/sup +/ ions and commercial ionophore 54 mV/decade H/sup +/ ions. The linear range was from pH 5-11. In the range of pH 6-10 response was excellent. The measurement of selectivity coefficients for the probable, interfering ions (anions and cations) were also carried out. (author)

  16. Improving the Response of Copper(II) Selective PVC Membrane Electrode by Modification of N2S2 Donor Ligand.

    Science.gov (United States)

    Brinić, Slobodan; Buzuk, Marijo; Generalić, Eni; Bralić, Marija

    2010-06-01

    S,S'-bis(2-aminophenyl)ethanebis(thioate), (APhET), is reported as N2S2 ligand which form chelate with copper of high stability as compared to the other metals. Two modification of APhET, simpler 1,2-di-(o-aminophenylthio)ethane (DAPhTE), and the complex one 1,2-di-(o-salicylaldiminophenylthio)ethane (SAPhTE), were examined as the active material for copper(II) ion selective PVC membrane electrodes, and observed results are correlated. The obtained results with DAPhTE based electrodes show that only coordination abilities of ligand are insufficient for preparing the efficient membrane material. On the other hand, the results that are achieved with electrodes based on SAPhTE actuate interaction of ligand with polymer membrane matrix and necessity of ionophore immobilization in membrane. Optimized SAPhTE based membrane electrode has a linear range down to 10-6 mol L-1, with slope of 27.0 mV per decade, very rapid response time (under 5 seconds) and detection limit of 5.1 × 10-7 mol L-1. Such electrode is suitable for determination of copper(II) in analytical measurements by direct potentiometry and in potentiometric titrations, within pH between 2 and 7. The electrode is selective for copper(II) ions over a large number of metal ions, with the exception on Hg2+ ion when is present in concentrations above 2 × 10-5 mol L-1.

  17. Studies of LENRA-Toughened PVC non-woven membranes prepared by electro spinning technique

    International Nuclear Information System (INIS)

    Dahlan Mohd; Mahathir Mohamed; Khirul Hafiz mohd Yusof

    2010-01-01

    Lately research in use of so-called green chemicals draws strong interest from research community due to the climate change issues. Malaysia is in strong position to take this advantage because we are among the world biggest producers of natural rubber and palm oil - the two sources of important green renewable chemical feedstock in the near future. For the last couple of years we have shown how modified natural rubbers especially liquid natural rubber and its derivatives such as liquid epoxidized natural rubber acrylate (LENRA) could be used in various applications via among others sol-gel technique and radiation curing technology. This time around we will show another application on how non-woven membranes made from PVC can be prepared by electro spinning technique using radiation curable LENRA as toughener. The electro spinning technique has great potential in producing nano fiber materials to be used in various applications to ensure sustainable energy and environments for the future. (author)

  18. Potentiometric Determination of Ketotifen Fumarate in Pharmaceutical Preparations and Urine Using Carbon Paste and PVC Membrane Selective Electrodes

    Directory of Open Access Journals (Sweden)

    Eman Y. Z. Frag

    2011-01-01

    Full Text Available This study compares between unmodified carbon paste (CPE; the paste has no ion pair and polyvinyl chloride (PVC membrane selective electrodes that were used in potentiometric determination of ketotifen fumarate (KTF, where sodium tetraphenylborate (NaTPB was used as titrant. The performance characteristics of these sensors were evaluated according to IUPAC recommendations which reveal a fast, stable, and linear response for KTF over the concentration range of 10−7 to 10−2 mol L−1. The electrodes show Nernstian slope value of 52.51±0.20 and 51.51±0.25 mV decade−1 for CPE and PVC membrane electrodes at 30∘C, respectively. The potential is nearly stable over the pH range 3.0–6.0 and 2.0–7.0 for CPE and PVC membrane electrodes, respectively. Selectivity coefficient values towards different inorganic cations, sugars, and amino acids reflect high selectivity of the prepared electrodes. The electrodes responses at different temperatures were also studied, and long operational lifetime of 12 and 5 weeks for CPE and PVC membrane electrodes, respectively, were found. These are used for determination of ketotifen fumarate using potentiometric titration, calibration, and standard addition methods in pure samples, its pharmaceutical preparations (Zaditen tablets, and biological fluid (urine. The direct potentiometric determination of KTF using the proposed sensors gave recoveries % of 98.97±0.53 and 98.62±0.74 with RSD 1.42 and 0.63% for CPE and PVC membrane selective electrodes, respectively. Validation of the method shows suitability of the proposed sensors for use in quality control assessment of KTF. The obtained results were in a good agreement with those obtained using the reported spectrophotometric method.

  19. Potentiometric determination of ketotifen fumarate in pharmaceutical preparations and urine using carbon paste and PVC membrane selective electrodes.

    Science.gov (United States)

    Frag, Eman Y Z; Mohamed, Gehad G; Khalil, Mohamed M; Hwehy, Mohammad M A

    2011-01-01

    This study compares between unmodified carbon paste (CPE; the paste has no ion pair) and polyvinyl chloride (PVC) membrane selective electrodes that were used in potentiometric determination of ketotifen fumarate (KTF), where sodium tetraphenylborate (NaTPB) was used as titrant. The performance characteristics of these sensors were evaluated according to IUPAC recommendations which reveal a fast, stable, and linear response for KTF over the concentration range of 10(-7) to 10(-2) mol L(-1). The electrodes show Nernstian slope value of 52.51 ± 0.20 and 51.51 ± 0.25 mV decade(-1) for CPE and PVC membrane electrodes at 30°C, respectively. The potential is nearly stable over the pH range 3.0-6.0 and 2.0-7.0 for CPE and PVC membrane electrodes, respectively. Selectivity coefficient values towards different inorganic cations, sugars, and amino acids reflect high selectivity of the prepared electrodes. The electrodes responses at different temperatures were also studied, and long operational lifetime of 12 and 5 weeks for CPE and PVC membrane electrodes, respectively, were found. These are used for determination of ketotifen fumarate using potentiometric titration, calibration, and standard addition methods in pure samples, its pharmaceutical preparations (Zaditen tablets), and biological fluid (urine). The direct potentiometric determination of KTF using the proposed sensors gave recoveries % of 98.97 ± 0.53 and 98.62 ± 0.74 with RSD 1.42 and 0.63% for CPE and PVC membrane selective electrodes, respectively. Validation of the method shows suitability of the proposed sensors for use in quality control assessment of KTF. The obtained results were in a good agreement with those obtained using the reported spectrophotometric method.

  20. PVC-membrane potentiometric sensors based on a recently synthesized Schiff base for Fe(III ion

    Directory of Open Access Journals (Sweden)

    S. Yousef Ebrahimipur

    2012-12-01

    Full Text Available A potentiometric iron sensor based on the use 3-(2-diethylamino-ethylimino-1,3-dihydro-indol-2-one (DEDIO as an ionophore in poly(vinyl chloride (PVC matrix, is reported. The plasticized membrane sensor exhibits a Nernstian response for Fe(III ions over a wide concentration range (2.0 × 10-6 - 5.0 × 10-2 M with a super Nernstian slope of 26(plus or minus 1 mV per decade. It has a fast response time of less than 12 s and can be used for ten weeks without any considerable divergences in its potentials the electrode can be used in the pH range 4.5-8.0. The proposed sensor shows fairly good discriminating ability towards Fe(III ion in comparison with a large number of alkali, alkaline earth, transition and heavy metal ions. The sensor was used as indicator electrode in potentiometric titration of Fe(III ions vs. EDTA.DOI: http://dx.doi.org/10.4314/bcse.v26i1.7

  1. Immobilization of tris(2 pyridyl methylamine in a PVC-Membrane Sensor and Characterization of the Membrane Properties

    Directory of Open Access Journals (Sweden)

    Rezayi Majid

    2012-05-01

    Full Text Available Abstract Background Due to the increasing industrial use of titanium compounds, its determination is the subject of considerable efforts. The ionophore or membrane active recognition is the most important component of any polymeric membrane sensor. The sensor’s response depends on the ionophore and bonding between the ionophore and the target ion. Ionophores with molecule-sized dimensions containing cavities or semi-cavities can surround the target ion. The bond between the ionophore and target ion gives different selectivity and sensitivity toward the other ions. Therefore, ionophores with different binding strengths can be used in the sensor. Results In the present work, poly (vinyl chloride (PVC based membrane incorporating tris (2 pyridyl methylamine (tpm as an ionophore has been prepared and explored as a titanium(III selective sensor. Conclusions The strengths of the ion–ionophore (Ti(OH2+-tpm interactions and the role of ionophore on membrane were tested by various techniques such as elemental analysis, UV–vis, Fourier transform infrared (FTIR spectroscopy, scanning electron microscopy (SEM, and powder X-ray diffraction (XRD. All data approved the successful incorporation of organic group via covalent bond.

  2. Immobilization of ionophore and surface characterization studies of the titanium(III) ion in a PVC-membrane sensor.

    Science.gov (United States)

    Rezayi, Majid; Heng, Lee Yook; Kassim, Anuar; Ahmadzadeh, Saeid; Abdollahi, Yadollah; Jahangirian, Hossein

    2012-01-01

    Novel ionophores comprising various hydroxide and amine structures were immobilized onto poly(vinyl chloride) (PVC) matrices, and these were examined to determine Ti(III) selectivity. To predict the selectivity of Ti(III), a PVC membrane was used to investigate the binding of Ti(III) to c-methylcalix[4]resorcinarene (CMCR). The study showed that the chelating ligand, CMCR, was coordinated selectively to Ti(III) at eight coordination sites involving the oxygen atoms at the interface of the membrane/solution. The membrane was prepared, based on CMCR as an ionophore, sodium tetrakis(4-fluorophenyl) borate (NaTFPB) as a lipophilic ionic additive, and dioctylphthalate (DOP) as a plasticizer. The immobilization of the ionophore and surface characterization studies revealed that the performance of CMCR-immobilized PVC was equivalent to that of mobile ionophores in supported liquid membranes (SLMs). The strengths of the ion-ionophore (CMCR-Ti(OH)(OH(2))(5) (2+)) interactions and the role of ionophores on membranes were studied via UV-Vis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and and X-ray diffraction (XRD).

  3. Strontium PVC-membrane sensor based on 2-[(2-mercaptophenylimino)methyl]phenol

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali [Young Researchers Club, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of)], E-mail: haszamani@yahoo.com; Ganjali, Mohammad Reza; Norouzi, Parviz [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Endocrine and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Adib, Mahdi [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of)

    2008-01-10

    The 2-[(2-mercaptophenylimino)methyl]phenol (MPMP) was used as an excellent ionophore in the construction of a Sr{sup 2+} PVC-based membrane sensor. The best performance was obtained with a membrane composition of 30% poly(vinyl chloride), 62% nitrobenzen (NB), 5.5% MPMP and 2.5% sodium tetraphenyl borate (NaTBP). This sensor demonstrates a good selectivity and sensitivity towards the strontium ion for many cations, including alkali, alkaline earth, transition and heavy metal ions. The sensor revealed a great enhancement in selectivity coefficients for strontium ions in comparison with the previously reported strontium sensors. The proposed sensor exhibits a Nernstian behavior (with a slope of 29.6 {+-} 0.3 mV per decade) for the concentration range of (1.0 x 10{sup -6}-1.0 x 10{sup -1} M) with a detection limit of 5.5 x 10{sup -7} M (48.2 ng/mL). It illustrates a relatively fast response time in the whole concentration range (< 10 s) and it can be used for at least 10 weeks in a pH range of 2.8-9.6. The developed sensor was successfully used as an indicator electrode in the Sr(II) titration with EDTA and the Sr{sup 2+} ion recovery from binary mixtures.

  4. Fabrication of a PVC membrane samarium(III) sensor based on N,N Prime ,N Double-Prime -tris(4-pyridyl)trimesic amide as a selectophore

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Naghavi-Reyabbi, Fatemeh [Resident of General Surgery, Endoscopic and Minimaly Invasive Surgery Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of); Faridbod, Farnoush [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Mohammadhosseini, Majid [Department of Chemistry, Faculty of Basic Sciences, Shahrood Branch, Islamic Azad University, Shahrood (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Tadjarodi, Azadeh; Rad, Maryam [Department of Chemistry, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

    2013-03-01

    A new ion-selective electrode for Sm{sup 3+} ion is described based on the incorporation of N,N Prime ,N Double-Prime -tris(4-pyridyl)trimesic amide (TPTA) in a poly(vinylchloride) (PVC) matrix. The membrane sensor comprises nitrobenzene (NB) as a plasticizer, and oleic acid (OA) as an anionic additive. The sensor with the optimized composition shows a Nernstian potential response of 19.8 {+-} 0.5 mV decade{sup -1} over a wide concentration range of 1.0 Multiplication-Sign 10{sup -2} and 1 Multiplication-Sign 10{sup -6} mol L{sup -1}, with a lower detection limit of 4.7 Multiplication-Sign 10{sup -7} mol L{sup -1} and satisfactor applicable pH range of 3.6-9.2. Having a short response time of less than 10 s and a very good selectivity towards the Sm{sup 3+} over a wide variety of interfering cations (e.g. alkali, alkaline earth, transition and heavy metal ions) the sensor seemed to be a promising analytical tool for determination of the Sm{sup 3+}. Hence, it was used as an indicator electrode in the potentiometric titration of samarium ion with EDTA. It was also applied to the direct samarium recovery in binary mixtures. - Highlights: Black-Right-Pointing-Pointer A new Sm{sup 3+}-PVC membrane sensor is introduced for determination of Sm{sup 3+} ions in the solutions. Black-Right-Pointing-Pointer N,N Prime ,N Double-Prime -tris(4-pyridyl)trimesic amide was used as a suitable selectophore for samarium sensor. Black-Right-Pointing-Pointer Detection limit of the sensor is 4.7 Multiplication-Sign 10{sup -7} mol L{sup -1} with a short response time of less than 10 s.

  5. Fabrication of a PVC membrane samarium(III) sensor based on N,N′,N″-tris(4-pyridyl)trimesic amide as a selectophore

    International Nuclear Information System (INIS)

    Zamani, Hassan Ali; Naghavi-Reyabbi, Fatemeh; Faridbod, Farnoush; Mohammadhosseini, Majid; Ganjali, Mohammad Reza; Tadjarodi, Azadeh; Rad, Maryam

    2013-01-01

    A new ion-selective electrode for Sm 3+ ion is described based on the incorporation of N,N′,N″-tris(4-pyridyl)trimesic amide (TPTA) in a poly(vinylchloride) (PVC) matrix. The membrane sensor comprises nitrobenzene (NB) as a plasticizer, and oleic acid (OA) as an anionic additive. The sensor with the optimized composition shows a Nernstian potential response of 19.8 ± 0.5 mV decade −1 over a wide concentration range of 1.0 × 10 −2 and 1 × 10 −6 mol L −1 , with a lower detection limit of 4.7 × 10 −7 mol L −1 and satisfactor applicable pH range of 3.6–9.2. Having a short response time of less than 10 s and a very good selectivity towards the Sm 3+ over a wide variety of interfering cations (e.g. alkali, alkaline earth, transition and heavy metal ions) the sensor seemed to be a promising analytical tool for determination of the Sm 3+ . Hence, it was used as an indicator electrode in the potentiometric titration of samarium ion with EDTA. It was also applied to the direct samarium recovery in binary mixtures. - Highlights: ► A new Sm 3+ -PVC membrane sensor is introduced for determination of Sm 3+ ions in the solutions. ► N,N′,N″-tris(4-pyridyl)trimesic amide was used as a suitable selectophore for samarium sensor. ► Detection limit of the sensor is 4.7 × 10 −7 mol L −1 with a short response time of less than 10 s.

  6. Construction of Tb3+ PVC-MembraneElectrode Based on N,N’-Bis(pyrrolylmethylene-2-aminobenzylamine

    Directory of Open Access Journals (Sweden)

    Hassan Ali Zamani

    2011-01-01

    Full Text Available In this work, we report as new Tb3+-PVC membrane sensor based on N,N’-bis(pyrrolylmethylene- 2-aminobenzylamine (PMA as a suitable ion carrier. Poly vinylchloride (PVC-based membrane composed of PMA with oleic acid (OA as anionic additives and acetophenone (AP as plasticizing solvent mediators. The Tb3+ sensor exhibits a Nernstian slope of 19.7±0.4 mV per decade over the concentration range of 1.0×10-5 to 1.0×10-2 M and a detection limit of 4.6×10-6 M of Tb3+ ions. The potentiometric response of the sensor is independent of the solution pH in the range of 2.9–8.1. It has a very short response time, in the whole concentration range (∼5 s. The recommended sensor revealed comparatively good selectivity with respect to most alkali, alkaline earth, some transition and heavy metal ions. It was successfully employed as an indicator electrode in the potentiometric titration of Tb(III ions with EDTA. The electrode was also employed for the determination of the fluoride ion in two mouth wash preparations and the determination of Tb3+ ions concentration in mixtures of three different ions.

  7. Comparative study of three different kinds of geo membranes (PVC-P, HDPE, EPDM) used in the waterproofing of reservoirs; Estudio comparativo de tres geomembranas de distinta naturaleza (PVC-P, PEAD, EPDM) empleadas en la impermeabilizacion de balsas

    Energy Technology Data Exchange (ETDEWEB)

    Blanco Fernandez, M.; Castillo Rubi, F.; Soriano Carrillo, J.; Noval Arango, A. M.; Touze-Foltz, N.; Pargada Iglesias, L.; Rico Arnaiz, G.; Aguilar gonzalez, E.

    2014-02-01

    This work describes the long-term behaviour of three kinds of geo membranes which are constituted by plasticised poly vinyl chloride (PVC-P), high density polyethylene (HDPE) and terpolymer rubber of ethylene-propylene-dienic monomer (EPDM) used as the waterproofing system of the reservoirs Los Llanos de Mesa, San Isidro and El Golfo, respectively. Characteristics of the three original geo membranes and their behaviour along time are presented. Thicknesses, content and nature of the plasticizers ( in PVC-P), tensile properties dynamic and static puncture, fold ability at low temperature, shore hardness, tear resistance and carbon black ( in HDPE), joint strength (shear and peeling test) and microscopy, both optical and electronic scanning tests were carried out. Results obtained conclude with a long-term durability of geo membranes, independently of their macromolecular nature. These characteristics were determined by advanced analytical techniques in PVC-P samples, such as fourier Transform Infrared Spectroscopy (FTIR), Gas Chromatography (GC) and Mass Spectrometry (MS). Spectrometry (MS). (Author)

  8. Long-Term Performance of the Laguna de Barlovento Reservoir Water-Proofing using a PVC-P Geo membrane

    International Nuclear Information System (INIS)

    Blanco Fernandez, M.; Leiro Lopez, A.; Soriano Carrillo, J.; Crespo Mucientes, M.; Zornberg, J.; Aguilar Gonzalez, E.; Rico Arnaiz, G.; Pargada Iglesias, L.

    2014-01-01

    The Laguna de Barlovento reservoir was one of the most important European hydraulic projects at the time of its construction because of its high capacity and challenging location. At the time, the designers decided to waterproof this reservoirs with a geo membrane of plasticized polyvinyl chloride (PVC-P). This paper documents the initial characteristics of the geo membrane and its performance since its installation until 2010. The material characterization includes a comprehensive testing program, the results of which are presented. They include quantification of the geo membrane thickness, amount and nature of plasticizers, tensile properties, fold ability under low temperatures, dynamic impact resistance, puncture resistance, welding strength (both in the manufacturing facility and in the field), as well as the use of techniques involving optical and scanning electron microscopy. In addition, advanced analytical techniques, such as Fourier Transform Infrared Spectroscopy (FTIR), Gas Chromatography (GC) and Mass spectrometry (MS), were used in order to identify the plasticizers used in the geo membrane formulation. Fold ability tests were found to provide early indication of degradation. Results from reflection optical and electron scanning microscopy showed that, after 19 nineteen years of installation, the geo membrane remains in good conditions, particularly on the non-exposed side. (Author)

  9. Study of PVC membrane grafted by Acrylic Acid, Acrylonitrile and Acrylamide using preirradiation method

    International Nuclear Information System (INIS)

    Kattan, M.; Al-Kasseri, H.

    2015-03-01

    Grafting of acrylic acid, acrylamide and acrylonitrile onto poly vinyl chloride (PVC) films using gamma radiation has been carried out by both type direct and preirradiation methods. The effect of different parameter such as monomer concentration, inhibitor concentration, reaction temperature, reaction time and irradiation dose on the grafting yield were investigated. It was found that the grafting yield depends on these parameters. The grafting yield was strongly monomer dependent and grafting method: the highest was found for AAc by the preirradiation method. The samples were characterized by tensile strength measurement, swilling and ion uptake. The highest increase in swilling was observed on samples grafted with AAc by the preirradiation method.(author)

  10. Construction of Tm{sup 3+}-PVC membrane sensor based on 1-(2-thiazolylazo)-2-naphthol as sensing material

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Quchan Branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Nekoei, Mehdi; Mohammadhosseini, Majid [Department of Chemistry, Faculty of Basic Sciences, Shahrood Branch, Islamic Azad University, Shahrood (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Medical Nanotechnology Research Centre, Tehran University of Medical Sciences, Tehran, P.O. Box, 14155-6451 (Iran, Islamic Republic of)

    2010-04-06

    In this study, a new thulium(III) membrane sensor was constructed. The proposed membrane sensor was fabricated based on a membrane containing 2% sodium tetraphenyl borate (NaTPB) as an anionic additive, 65% benzyl acetate (BA) as solvent mediator, 3% 1-(2-thiazolylazo)-2-naphthol (TN) as ionophore, and 30% poly(vinyl chloride) (PVC). The proposed Tm{sup 3+} electrode exhibits a Nernstian response of 19.5 {+-} 0.2 mV per decade of thulium concentration, and has a lower detection limit of 8.7 x 10{sup -7} mol L{sup -1}. The linear range of the sensors was 1.0 x 10{sup -6} to 1.0 x 10{sup -2} mol L{sup -1}. It works well in the pH range of 3.2-9.5. Moreover, the recommended selective sensor revealed a comparatively satisfactory selectivity regarding most of the alkali, alkaline earth, some transition and heavy metal ions. The membrane sensor was applied to the determination of fluoride ions in mouth wash samples.

  11. Construction of Tm3+-PVC membrane sensor based on 1-(2-thiazolylazo)-2-naphthol as sensing material

    International Nuclear Information System (INIS)

    Zamani, Hassan Ali; Nekoei, Mehdi; Mohammadhosseini, Majid; Ganjali, Mohammad Reza

    2010-01-01

    In this study, a new thulium(III) membrane sensor was constructed. The proposed membrane sensor was fabricated based on a membrane containing 2% sodium tetraphenyl borate (NaTPB) as an anionic additive, 65% benzyl acetate (BA) as solvent mediator, 3% 1-(2-thiazolylazo)-2-naphthol (TN) as ionophore, and 30% poly(vinyl chloride) (PVC). The proposed Tm 3+ electrode exhibits a Nernstian response of 19.5 ± 0.2 mV per decade of thulium concentration, and has a lower detection limit of 8.7 x 10 -7 mol L -1 . The linear range of the sensors was 1.0 x 10 -6 to 1.0 x 10 -2 mol L -1 . It works well in the pH range of 3.2-9.5. Moreover, the recommended selective sensor revealed a comparatively satisfactory selectivity regarding most of the alkali, alkaline earth, some transition and heavy metal ions. The membrane sensor was applied to the determination of fluoride ions in mouth wash samples.

  12. All-Solid-State, PVC Membrane, and Carbon Paste Ion-Selective Electrodes for Determination of Donepezil Hydrochloride in Pharmaceutical Formulation.

    Science.gov (United States)

    Khamees, Nesreen; Mohamed, Tagreed Abdel-Fattah; Derar, Abeer Rashad; Aziz, Azza

    2017-09-01

    All-solid-state, polyvinyl chloride (PVC) membrane, and carbon paste potentiometric ion-selective electrodes (ISEs) were proposed for the determination of donepezil hydrochloride (DON) in the drug substance and a pharmaceutical formulation. The potentiometric response toward DON was based on the existence of donepezil-tetraphenyl borate (DON-TPB) in a PVC membrane or a carbon paste in the presence of dioctylphthalate. In contrast, the solid-state electrode was prepared by direct incorporation of DON-TPB into a commercial nail varnish without external additives. The electrodes exhibited Nernstian slopes of 55.0, 57.0, and 53.0 mV/decade over the concentration ranges of 1 × 10-5 to 1 × 10-3, 1 × 10-4 to 10-2, and 1 × 10-4 to 5 × 10-3 for the solid-state, PVC membrane, and carbon paste electrodes, respectively. The response of the electrodes is independent of pH in the range of 2-≤8. The electrodes showed good selectivity for DON with respect to a number of inorganic cations and amino acids. The electrodes were used for the determination of DON in pure solution and in pharmaceutical tablets with high accuracy (±2%) and precision (RSD ≤2%). The solid-state electrode is simple, economical, and rapid when compared to the PVC membrane and carbon paste electrodes.

  13. Neodymium(III PVC Membrane Electrodchemical Sensor Based on N-benzoylethylidene-2-aminobenzylamine

    Directory of Open Access Journals (Sweden)

    Hassan Ali Zamani

    2012-01-01

    Full Text Available The N-benzoylethylidene-2-aminobenzylamine (BEA was used as a suitable ionophore in construction of neodymium ion selective electrode. The electrode with composition of 30% PVC, 58% solvent mediator (NB, 2% ionophore (BEA and 10% anionic additive (OA shows the best potentiometric response characteristics. The Nd3+ sensor exhibits a Nernstian slope of 21.2 ± 0.2 mV decade-1 over the concentration range of 1.0 × 10-6 to 1.0 × 10-2 mol L-1, and a detection limit of 6.3 × 10-7 mol L-1 of Nd3+ ions. The potentiometric response of the sensor is independent of the solution pH in the range of 2.4–8.5. It has a very short response time, in the whole concentration range (~7 s, and can be used for at least eight weeks. The proposed sensor revealed high selectivity with respect to all common alkali, alkaline earth, transition and heavy metal ions, including members of the lanthanide family other than Nd3+. The Nd3+ sensor was successfully applied as an indicator electrode in the potentiometric titration of Nd3+ ions with EDTA. The electrode was also employed for the determination of the fluoride ion in two mouth wash preparations.

  14. Application of N-Quinoline-2-carboxamido-8-aminoquinoline in Fabrication of a Ho(III-PVC Membrane Sensor

    Directory of Open Access Journals (Sweden)

    Hassan Ali Zamani

    2011-01-01

    Full Text Available The N-quinoline-2-carboxamido-8-aminoquinoline (QCA was used as a suitable ion carrier in the construction of a Ho(III PVC-based membrane sensor. This sensor demonstrated good selectivity and sensitivity towards the holmium ion for a broad variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The proposed electrode exhibits a linear dynamic range between 1.0×10-6 and 1.0×10-2 M, with a near Nernstian slope of 20.4±0.3 mV per decade and a detection limit of 4.2×10-7 M. The best performance was obtained with a membrane composition of 30% poly(vinyl chloride, 56% nitrobenzene, 2% sodium tetraphenyl borate, 10% oleic acid and 2% QCA. The potentiometric response of the constructed electrode is pH independent in the range of 2.4-7.4. The sensor possesses the advantages of short conditioning time, fast response time (∼ 5 s and especially, good selectivity towards transition and heavy metal and some mono, di and trivalent cations. The Ho3+ sensor was successfully applied as an indicator electrode in the potentiometric titration of Ho(III ions with EDTA. The electrode was also used for the determination of Ho3+ ions in mixtures of different ions and the determination of the fluoride ion in mouth wash solutions.

  15. Fabrication of copper-selective PVC membrane electrode based on newly synthesized copper complex of Schiff base as carrier

    Directory of Open Access Journals (Sweden)

    Sulekh Chandra

    2016-09-01

    Full Text Available The newly synthesized copper(II complex of Schiff base p-hydroxyacetophenone semicarbazone was explored as neutral ionophore for the fabrication of poly(vinylchloride (PVC based membrane electrode selective to Cu(II ions. The electrode shows a Nernstian slope of 29.8 ± 0.3 mV/decade with improved linear range of 1.8 × 10−7 to 1.0 × 10−1 M, comparatively lower detection limit 5.7 × 10−8 M between pH range of 2.0–8.0, giving a relatively fast response within 5s and can be used for at least 16 weeks without any divergence in potential. The selectivity coefficient was calculated using the fixed interference method (FIM. The electrode can also be used in partially non-aqueous media having up to 25% (v/v methanol, ethanol or acetone content with no significant change in the value of slope or working concentration range. It was successfully applied for the direct determination of copper content in water and tea samples with satisfactory results. The electrode has been used in the potentiometric titration of Cu2+ with EDTA.

  16. Lanthanum(IlI) PVC membrane electrodes based on 1,3,5-trithiacyclohexane.

    Science.gov (United States)

    Shamsipur, Mojtaba; Yousefi, Mohammad; Hosseini, Morteza; Ganjali, Mohammad Reza

    2002-11-01

    Novel plasticized polymeric membrane (PPME) and membrane-coated graphite (MCGE) electrodes based on 1,3,5-trithiacyclohexane for highly selective determination of La3+ ion have been developed. The electrodes exhibit Nernstian responses over very wide concentration ranges (8.0 x 10(-6)-5.0 x 10(-2) M for PPME and 4.0 x 10(-8)-1.0 x 10(-2) M for MCGE). The limit of detections were 5.0 x 10(-6) and 2.0 x 10(-8) M for PPME and MCGE, respectively. The electrodes possess a fast response time of approximately 10 s and can be used for at least 6 months without observing any deviation. The proposed electrodes revealed excellent selectivities for La3+ over a wide variety of alkali, alkaline earth, transition, and heavy metal ions and could be used in a pH range of 5.0-8.0. The practical utility of the electrodes has been demonstrated by their use as indicator electrodes in the potentiometric titration of La3+ ions with EDTA and in determination of F- in some mouthwash preparations.

  17. A new PVC based membrane sensor of dibenzo-18-crown-6 for strontium

    International Nuclear Information System (INIS)

    Singh, Ashok K.; Bhattacharjee, G.; Baniwal, Seema; Singh, Manendra

    1999-01-01

    Dibenzo-18-crown-6 crown ether is found to exhibit quite promising selectivity for Sr 2+ ions. It can be used to estimate strontium in the range 5.0 x 10 -6 to 1.0 x 10 -1 mol dm -3 (0.28 to 8.76 x 10 -3 mg dm -3 ) with a near-Nernstian slope of 28 mV per decade of concentration. The working pH range of the proposed sensor is 2.0-6.0 with a response time of 25 s. The sensor can be used for more than three months in aqueous as well as in partially non-aqueous media. The practical utility of the membrane sensor has also been observed in solutions contaminated with detergent matter. (author)

  18. Potentiometric determination of moxifloxacin in some pharmaceutical formulation using PVC membrane sensors.

    Science.gov (United States)

    Hefnawy, Mohammed M; Homoda, Atef M; Abounassif, Mohammed A; Alanazi, Amer M; Al-Majed, Abdulrahaman; Mostafa, Gamal A

    2014-01-01

    The construction and electrochemical response characteristics of Poly (vinyl chloride) membrane sensors for moxifloxacin HCl (MOX) are described. The sensing membranes incorporate ion association complexes of moxifloxacin cation and sodium tetraphenyl borate (NaTPB) (sensor 1), phosphomolybdic acid (PMA) (sensor 2) or phosphotungstic acid (PTA) (sensor 3) as electroactive materials. The sensors display a fast, stable and near-Nernstian response over a relative wide moxifloxacin concentration range (1 × 10(-2) - 4.0 × 10(-6), 1 × 10(-2) - 5.0 × 10(-6), 1 × 10(-2) - 5.0 × 10(-6) M), with detection limits of 3 × 10(-6), 4 × 10(-6) and 4.0 × 10(-6) M for sensor 1, 2 and 3, respectively over a pH range of 6.0 - 9.0. The sensors show good discrimination of moxifloxacin from several inorganic and organic compounds. The direct determination of 400 μg/ml of moxifloxacin show an average recovery of 98.5, 99.1 and 98.6% and a mean relative standard deviation of 1.8, 1.6 and 1.8% for sensors 1, 2 and 3 respectively. The proposed sensors have been applied for direct determination of moxifloxacin in some pharmaceutical preparations. The results obtained by determination of moxifloxacin in tablets using the proposed sensors are comparable favorably with those obtained using the US Pharmacopeia method. The sensors have been used as indicator electrodes for potentiometric titration of moxifloxacin.

  19. Europium (III) PVC membrane sensor based on N-pyridine-2-carboxamido-8-aminoquinoline as a sensing material

    International Nuclear Information System (INIS)

    Zamani, Hassan Ali; Kamjoo, Rahman; Mohammadhosseini, Majid; Zaferoni, Mojdeh; Rafati, Zynab; Ganjali, Mohammad Reza; Faridbod, Farnoush; Meghdadi, Soraia

    2012-01-01

    Conductometric study in acetonitrile solution shows the selectivity of PCQ toward europium ion. Therefore, a new europium PVC membrane electrode was prepared based on N-pyridine-2-carboxamido-8-aminoquinoline (PCQ) as an ion carrier. The electrode has a wide concentration range from 1.0 × 10 −2 and 1.0 × 10 −6 mol L −1 , Nernstian slope of 19.8 ± 0.3 mV per decade and a detection limit of 6.4 × 10 −7 mol L −1 . The potentiometric response is pH independent in the range of 2.4–7.4. The proposed sensor has a relatively fast response time less than 10 s and it can be used for at least 2 months without any considerable divergence in its potentials. The proposed electrode revealed good selectivity toward europium ion in comparison with variety of other metal ions. The practical utility of the electrodes has been demonstrated by their use as indicator electrodes in the potentiometric titration of Eu 3+ ions with EDTA and for determination of Eu 3+ ion concentration in mixtures of two and three different ions. - Highlights: ► A new ion carrier is introduced to preparation of a selective sensor for Eu 3+ ions. ► This technique is very simple and it's not necessary to use sophisticated equipment. ► The novelty of this work is the high affinity of the ionophore toward the Eu 3+ ions. ► The sensor is superior to the formerly reported Eu 3+ sensors in terms of selectivity.

  20. Europium (III) PVC membrane sensor based on N-pyridine-2-carboxamido-8-aminoquinoline as a sensing material

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Kamjoo, Rahman [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Mohammadhosseini, Majid [Department of Chemistry, Faculty of Basic Sciences, Shahrood Branch, Islamic Azad University, Shahrood (Iran, Islamic Republic of); Zaferoni, Mojdeh; Rafati, Zynab [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Faridbod, Farnoush [Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Meghdadi, Soraia [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2012-04-01

    Conductometric study in acetonitrile solution shows the selectivity of PCQ toward europium ion. Therefore, a new europium PVC membrane electrode was prepared based on N-pyridine-2-carboxamido-8-aminoquinoline (PCQ) as an ion carrier. The electrode has a wide concentration range from 1.0 Multiplication-Sign 10{sup -2} and 1.0 Multiplication-Sign 10{sup -6} mol L{sup -1}, Nernstian slope of 19.8 {+-} 0.3 mV per decade and a detection limit of 6.4 Multiplication-Sign 10{sup -7} mol L{sup -1}. The potentiometric response is pH independent in the range of 2.4-7.4. The proposed sensor has a relatively fast response time less than 10 s and it can be used for at least 2 months without any considerable divergence in its potentials. The proposed electrode revealed good selectivity toward europium ion in comparison with variety of other metal ions. The practical utility of the electrodes has been demonstrated by their use as indicator electrodes in the potentiometric titration of Eu{sup 3+} ions with EDTA and for determination of Eu{sup 3+} ion concentration in mixtures of two and three different ions. - Highlights: Black-Right-Pointing-Pointer A new ion carrier is introduced to preparation of a selective sensor for Eu{sup 3+} ions. Black-Right-Pointing-Pointer This technique is very simple and it's not necessary to use sophisticated equipment. Black-Right-Pointing-Pointer The novelty of this work is the high affinity of the ionophore toward the Eu{sup 3+} ions. Black-Right-Pointing-Pointer The sensor is superior to the formerly reported Eu{sup 3+} sensors in terms of selectivity.

  1. PVC Based Membrane of Ti(IV Iodovanadate for Pb(II Determination

    Directory of Open Access Journals (Sweden)

    Mu. Naushad

    2008-08-01

    Full Text Available Ti(IV iodovanadate has been synthesized by mixing a mixture of aqueous solutions of 0.1 M sodium vanadate and 0.1 M potassium iodate with 0.1 M solution of Ti(IV chloride at pH 1.0. Distribution coefficients (Kd of various metal ions were determined on the column of Ti(IV iodovanadate which showed the selectivity of Pb(II ions by this cation exchange material. So Ti(IV iodovanadate has been used as an electoactive material for the construction of Pb(II selective electrode. The main purpose of this study is to develop an inexpensive, simple and reliable ion-selective electrode for Pb(II determination. The sensor exhibit Nernstian response for Pb(II ions over a wide concentration range of 1 x 10-7 M to 1 x 10-1 M with a slope of 30±0.4 mV per decade of activity. The electrode is suitable for use in aqueous solution in a pH range of 2-7.2 with a response time of 10 second. The membrane electrode can be used at least for 4 months without any divergence in potential. The selectivity coefficients were determined by the mixed solution method and revealed that the electrode was selective for Pb(II ions in the presence of interfering cations. The sensor could be used as an indicator electrode in the potentiometric titration of Pb(II ions with EDTA. The practical applicability of the proposed sensor has been reported for Pb(II determination in a standard rock sample and water sample. The results are found to be in good agreement with those obtained by using conventional methods.

  2. Selective sensing of mercury(II) using PVC-based membranes incorporating recently synthesized 1,3-alternate thiacalix[4]crown ionophore.

    Science.gov (United States)

    Mahajan, Rakesh Kumar; Kamal, Ajar; Kumar, Naresh; Bhalla, Vandana; Kumar, Manoj

    2013-05-01

    The construction and electrodes characteristics of poly(vinylchloride) (PVC)-based polymeric membrane electrode (PME) and coated graphite electrode (CGE), incorporating 1,3-alternate thiacalix[4]crown as ionophore for estimation of Hg(II) ions, are reported here. The best potential response was observed for PME-1 having membrane composition of: ionophore (6.2 mg), PVC (100.0 mg), 2-nitrophenyl octyl ether (2-NPOE; 200.0 mg), and sodium tetraphenyl borate (NaTPB; 2.0 mg); for CGE-1 with the membrane composition: ionophore (3.5 mg), PVC (40.0 mg), 2-NPOE (80.0 mg), and NaTPB (2.0 mg). The electrodes exhibits Nernstian slope of 29.16 mV/decade with PME-1 and 30.39 mV/decade with CGE-1 for Hg(II) ions over wide concentration range, i.e., 1.0 × 10(-1) to 5.0 × 10(-6) M with PME-1 and 1.0 × 10(-1) to 5.0 × 10(-7) M with CGE-1. Lower detection limits were found to be 9.77 × 10(-6) M for PME-1 and 7.76 × 10(-7) M for CGE-1 with response time varying from 10 to 20 s. Also, these electrodes work within pH range of 2.0-6.0 for PME-1 and 1.5-6.5 for CGE-1. Overall, CGE-1 has been found to be better than PME-1. CGE-1 has been used as indicator electrode for the potentiometric titration of Hg(II) ions with EDTA as well as successfully applied for determination of Hg(II) content in wastewater, insecticide, dental amalgam, and ayurvedic medicines samples with very good performance (0.9974 correlation coefficient in the comparison against volumetric method).

  3. Characterization of membrane association of Rinderpest virus matrix protein

    International Nuclear Information System (INIS)

    Subhashri, R.; Shaila, M.S.

    2007-01-01

    Paramyxovirus matrix protein is believed to play a crucial role in the assembly and maturation of the virus particle by bringing the major viral components together at the budding site in the host cell. The membrane association capability of many enveloped virus matrix proteins has been characterized to be their intrinsic property. In this work, we have characterized the membrane association of Rinderpest virus matrix (M) protein. The M protein of Rinderpest virus when expressed in the absence of other viral proteins is present both in the cytoplasm and plasma membrane. When expressed as GFP fusion protein, the M protein gets localized into plasma membrane protrusions. High salt and alkaline conditions resulted in partial dissociation of M protein from cell membrane. Thus, M protein behaves like an integral membrane protein although its primary structure suggests it to be a peripheral membrane protein

  4. Cation Recognition: Novel Potentiometric PVC-Membrane Sensor based on Meso-octamethylcalix[4]pyrrole for the Determination of Trace Amounts of Titanium (III) Ions

    International Nuclear Information System (INIS)

    Saeid Ahmadzadeh; Anuar Kassim Majid Rezayi

    2011-01-01

    The present work deals with developing a novel high selective membrane electrode based on meso-octamethylcalix[4]pyrrole for accurate determination of trace amount of titanium (III) ions in real sample solutions. The amounts of ionophore (4 mg), PVC (33 mg), dioctyl phthalate (DOP) as plasticizer (62.8 mg) and sodium tetrakis [3,5-bis (trifluoromethyl) phenyl] borate (NaTFPB) as an ionic additive (0.2 mg) were optimized in the preparation of the membrane. The electrode exhibited a linear response with a near Nernstian slope of 29.49±0.16 (mV per decade of activity) over the pH range from 1 to 3 with a satisfactory concentration range of 1.0 x 10 -6 to 1.0 x x10 -2 M. The developed sensor exhibited good reproducibility over a period of about 3 months with a fast response time of 15 seconds. (author)

  5. Flow Injection Potentiometric Determination of Cd2+ Ions Using a Coated Graphite Plasticized PVC-Membrane Electrode Based on 1, 3-Bis(2-cyanobenzene)triazene.

    Science.gov (United States)

    Shamsipur, Mojtaba; Sahari, Shokat; Payehghadr, Mahmood; Alizadeh, Kamal

    2011-09-01

    1, 3-Bis(2-cyanobenzene)triazene, L, was used as a suitable ionophore for the fabrication of a new PVC-based polymeric membrane coated graphite electrode for selective sensing of Cd2+ ion. The electrode exhibited a selective linear Nernstian response to Cd2+ ion at an optimal pH range of 6-9 with a limit of detection of 8.0 × 10-6 M and a fast response time of about 2 s. The electrode was used as a proper detection system in flow-injection potentiometry of cadmium ion and resulted in well defined peaks for cadmium ions with stable baseline, excellent reproducibility and high sampling rates of over 100 injections per hour. It showed good stability, reproducibility and fast response time. The practical utility of the proposed system has also been reported.

  6. Mixed-matrix membrane adsorbers for protein separation

    NARCIS (Netherlands)

    Avramescu, M.E.; Borneman, Z.; Wessling, M.

    2003-01-01

    The separation of two similarly sized proteins, bovine serum albumin (BSA) and bovine hemoglobin (Hb) was carried out using a new type of ion-exchange mixed-matrix adsorber membranes. The adsorber membranes were prepared by incorporation of various types of Lewatit ion-exchange resins into an

  7. A ROIC for Mn(TPP)Cl-DOP-THF-Polyhema PVC membrane modified n-channel Si3N4 ISFET sensitive to histamine.

    Science.gov (United States)

    Samah, N L M A; Lee, Khuan Y; Sulaiman, S A; Jarmin, R

    2017-07-01

    Intolerance of histamine could lead to scombroid poisoning with fatal consequences. Current detection methods for histamine are wet laboratory techniques which employ expensive equipment that depends on skills of seasoned technicians and produces delayed test analysis result. Previous works from our group has established that ISFETs can be adapted for detecting histamine with the use of a novel membrane. However, work to integrate ISFETs with a readout interfacing circuit (ROIC) circuit to display the histamine concentration has not been reported so far. This paper concerns the development of a ROIC specifically to integrate with a Mn(TPP)Cl-DOP-THF-Polyhema PVC membrane modified n-channel Si3N4 ISFET to display the histamine concentration. It embodies the design of constant voltage constant current (CVCC) circuit, amplification circuit and micro-controller based display circuit. A DC millivolt source is used to substitute the membrane modified ISFET as preliminary work. Input is histamine concentration corresponding to the safety level designated by the Food and Drugs Administration (FDA). Results show the CVCC circuit makes the output follows the input and keeps VDS constant. The amplification circuit amplifies the output from the CVCC circuit to the range 2.406-4.888V to integrate with the microcontroller, which is programmed to classify and display the histamine safety level and its corresponding voltage on a LCD panel. The ROIC could be used to produce direct output voltages corresponding to histamine concentrations, for in-situ applications.

  8. Carbon Nano tubes Based Mixed Matrix Membrane for Gas Separation

    International Nuclear Information System (INIS)

    Sanip, S.M.; Ismail, A.F.; Goh, P.S.; Norrdin, M.N.A.; Soga, T.; Tanemura, M.; Yasuhiko, H.

    2011-01-01

    Carbon nano tubes based mixed matrix membrane (MMM) was prepared by the solution casting method in which the functionalized multi walled carbon nano tubes (f-MWNTs) were embedded into the polyimide membrane and the resulting membranes were characterized. The effect of nominal MWNTs content between 0.5 and 1.0 wt % on the gas separation properties were looked into. The morphologies of the MMM also indicated that at 0.7 % loading of f- MWNTs, the structures of the MMM showed uniform finger-like structures which have facilitated the fast gas transport through the polymer matrix. It may also be concluded that addition of open ended and shortened MWNTs to the polymer matrix can improve its permeability by increasing diffusivity through the MWNTs smooth cavity. (author)

  9. Recent advances on mixed matrix membranes for CO2 separation

    Institute of Scientific and Technical Information of China (English)

    Ming Wang; Zhi Wang; Song Zhao; Jixiao Wang; Shichang Wang

    2017-01-01

    Recent advances on mixed matrix membrane for CO2 separation are reviewed in this paper. To improve CO2 separation performance of polymer membranes, mixedmatrixmembranes (MMMs) are developed. The concept of MMM is illustrated distinctly. Suitable polymer and inorganic or organic fillers for MMMs are summarized.Possible interface morphologies between polymer and filler, and the effect of interface morphologies on gas transport properties of MMMs are summarized. The methods to improve compatibility between polymer and filler are introduced. There are eightmethods including silane coupling, Grignard treatment, incorporation of additive,grafting, in situ polymerization, polydopamine coating, particle fusion approach and polymer functionalization. To achieve higher productivity for industrial application,mixed matrix composite membranes are developed. The recent development on hollow fiber and flat mixedmatrix composite membrane is reviewed in detail. Last, the future trend of MMM is forecasted.

  10. Polyether sulfone/hydroxyapatite mixed matrix membranes for protein purification

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Junfen, E-mail: junfensun@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, North People Road 2999, Shanghai 201620 (China); Wu, Lishun [Department of Chemistry and Chemical Engineering, Heze University, Daxue Road 2269, Heze, Shandong Province 274015 (China)

    2014-07-01

    This work proposes a novel approach for protein purification from solution using mixed matrix membranes (MMMs) comprising of hydroxyapatite (HAP) inside polyether sulfone (PES) matrix. The influence of HAP particle loading on membrane morphology is studied. The MMMs are further characterized concerning permeability and adsorption capacity. The MMMs show purification of protein via both diffusion as well as adsorption, and show the potential of using MMMs for improvements in protein purification techniques. The bovine serum albumin (BSA) was used as a model protein. The properties and structures of MMMs prepared by immersion phase separation process were characterized by pure water flux, BSA adsorption and scanning electron microscopy (SEM).

  11. Effect of casting solvents and filler quantity on the preparation and physiochemical properties of PVC-bentonite based composite polymeric membranes

    International Nuclear Information System (INIS)

    Hamid, A.; Mukhtar, A.; Ghauri, M. S.; Ali, A.

    2013-01-01

    Two series of Composite Polymeric Membranes (CPMs) based on Poly (Vinyl Chloride) (PVC) and inorganic filler were prepared by solvent casting method, using Tetrahydrofuran (THF) and a mixture of THF and Dimethylsulfoxide (DMSO). The different percentages (5-35 %) of Bentonite clay (79-89 mesh, ASTM) filler were used. The physicochemical parameters of the CPMs i.e. degree of perpendicular swelling, liquid uptake (water, methanol and ethanol), density, ion adsorption capacity (IAC), porosities, electrical resistivity and conductivities were evaluated. The Type-B CPMs cast with THF and DMSO mixture have greater values of the above parameters except density than the Type-A CPMs cast with THF only. The CPMs having more filler show more liquid uptake. The uptake of Water, ethyl alcohol (EtOH), 5M methanol and methanol (MeOH) in Type-B CPMs was found 8-11, 10.12-12.83, 3.40-10.88 and 11.37-15.25 times more than Type-A CPMs. Proton ion adsorption capacity of Type-B CPMs was calculated 2.83 to 8.4 times more than Type-A CPMs. The porosity range of Type-A CPMs was observed 0.0377 to 0.093, 0.0227 to 0.0909, 0.02 to 0.0408 and 0.0476 to 0.1112; whereas porosity range in Type-B CPMs were noted 0.1955 to 0.4919, 0.1477 to 0.4835, 0.115 to 0.2554 and 0.1177 to 0.4447 in deionized water, EtOH, 5M MeOH and MeOH respectively. The conductivity of Type-B CPMs was 150-333 times greater than Type-A CPMs. These all characteristics were compared with pure Poly (Vinyl Chloride) membrane (prepared and studied by same method) cast with DMSO and without DMSO. (author)

  12. A highly sensitive PVC membrane iodide electrode based on complexes of mercury(II) as neutral carrier.

    Science.gov (United States)

    Chai, Y-Q; Yuan, R; Xu, L; Xu, W-J; Dai, J-Y; Jiang, F

    2004-09-01

    A novel solvent polymeric membrane electrode based on bis(1,3,4-thiadiazole) complexes of Hg(II) is described which has excellent selectivity and sensitivity toward iodide ion. The electrode, containing 1,4-bis(5-methyl-1,3,4-thiadiazole-2-yl-thio)butanemercury(II) [Hg(II)BMTB(NO3)4], has a Nernstian potentiometric response from 2.0 x 10(-8) to 2.0 x 10(-2) mol L(-1) with a detection limit of 8.0 x 10(-9) mol L(-1) and a slope of -59.0+/-0.5 mV/decade in 0.01 mol L(-1) phosphate buffer solution (pH 3.0, 20 degrees C). The selectivity sequence observed is iodide>bromide>thiocyanate>nitrite>nitrate>chloride>perchlorate>acetate>sulfate. The selectivity behavior is discussed in terms of the UV-Vis spectrum, and the process of transfer of iodide across the membrane interface is investigated by use of the AC impedance technique. The electrode was successfully applied to the determination of iodide in Jialing River and Spring in Jinyun Mountains, with satisfactory results.

  13. Hybrid and Mixed Matrix Membranes for Separations from Fermentations

    Directory of Open Access Journals (Sweden)

    Christopher John Davey

    2016-02-01

    Full Text Available Fermentations provide an alternative to fossil fuels for accessing a number of biofuel and chemical products from a variety of renewable and waste substrates. The recovery of these dilute fermentation products from the broth, however, can be incredibly energy intensive as a distillation process is generally involved and creates a barrier to commercialization. Membrane processes can provide a low energy aid/alternative for recovering these dilute fermentation products and reduce production costs. For these types of separations many current polymeric and inorganic membranes suffer from poor selectivity and high cost respectively. This paper reviews work in the production of novel mixed-matrix membranes (MMMs for fermentative separations and those applicable to these separations. These membranes combine a trade-off of low-cost and processability of polymer membranes with the high selectivity of inorganic membranes. Work within the fields of nanofiltration, reverse osmosis and pervaporation has been discussed. The review shows that MMMs are currently providing some of the most high-performing membranes for these separations, with three areas for improvement identified: Further characterization and optimization of inorganic phase(s, Greater understanding of the compatibility between the polymer and inorganic phase(s, Improved methods for homogeneously dispersing the inorganic phase.

  14. Hybrid and Mixed Matrix Membranes for Separations from Fermentations.

    Science.gov (United States)

    Davey, Christopher John; Leak, David; Patterson, Darrell Alec

    2016-02-29

    Fermentations provide an alternative to fossil fuels for accessing a number of biofuel and chemical products from a variety of renewable and waste substrates. The recovery of these dilute fermentation products from the broth, however, can be incredibly energy intensive as a distillation process is generally involved and creates a barrier to commercialization. Membrane processes can provide a low energy aid/alternative for recovering these dilute fermentation products and reduce production costs. For these types of separations many current polymeric and inorganic membranes suffer from poor selectivity and high cost respectively. This paper reviews work in the production of novel mixed-matrix membranes (MMMs) for fermentative separations and those applicable to these separations. These membranes combine a trade-off of low-cost and processability of polymer membranes with the high selectivity of inorganic membranes. Work within the fields of nanofiltration, reverse osmosis and pervaporation has been discussed. The review shows that MMMs are currently providing some of the most high-performing membranes for these separations, with three areas for improvement identified: Further characterization and optimization of inorganic phase(s), Greater understanding of the compatibility between the polymer and inorganic phase(s), Improved methods for homogeneously dispersing the inorganic phase.

  15. Novel PVC-membrane potentiometric sensors based on a recently synthesized sulfur-containing macrocyclic diamide for Cd2+ ion. Application to flow-injection potentiometry.

    Science.gov (United States)

    Shamsipur, Mojtaba; Dezaki, Abbas Shirmardi; Akhond, Morteza; Sharghi, Hashem; Paziraee, Zahra; Alizadeh, Kamal

    2009-12-30

    A new sulfur-containing macrocyclic diamide, 1,15-diaza-3,4,12,13-dibenzo-5,11-dithia-8-oxa-1,15-(2,6-pyrido)cyclooctadecan-2,14-dione, L, was synthesized, characterized and used as an active component for fabrication of PVC-based polymeric membrane (PME), coated graphite (CGE) and coated silver wire electrodes (CWE) for sensing Cd(2+) ion. The electrodes exhibited linear Nernstian responses to Cd(2+) ion in the concentration range of 3.3 x 10(-6) to 3.3 x 10(-1)M (for PME, LOD=1.2 x 10(-6)M), 2.0 x 10(-7) to 3.3 x 10(-1)M (for CWE, LOD=1.3 x 10(-7)M) and 1.6 x 10(-8) to 1.3 x 10(-1)M (for CGE, LOD=1.0 x 10(-8)M). The CGE was used as a proper detection system in flow-injection potentiometry (FIP) with a linear Nernstian range of 3.2 x 10(-8) to 1.4 x 10(-1)M (LOD=1.3 x 10(-8)M). The optimum pH range was 3.5-7.6. The electrodes revealed fairly good discriminating ability towards Cd(2+) in comparison with a large number of alkali, alkaline earth, transition and heavy metal ions. The electrodes found to be chemically inert, showing a fast response time of <5s, and could be used practically over a period of about 2-3 months. The practical utility of the proposed system has also been reported.

  16. Polymeric matrix membrane sensors for stability-indicating potentiometric determination of oxybutynin hydrochloride and flavoxate hydrochloride urogenital system drugs.

    Science.gov (United States)

    Heba, Mohamed; Ramadan, Nesrin; El-Laithy, Moustafa

    2008-01-01

    Four polyvinyl chloride (PVC) matrix membrane electrodes responsive to 2 drugs affecting the urogenital system--oxybutynin hydrochloride (OX) and flavoxate hydrochloride (FX)--were developed, described, and characterized. A precipitation-based technique with tungstophosphate (TP) and ammonium reineckate (R) anions as electroactive materials in a PVC matrix with an OX cation was used for electrode 1 and 2 fabrication, respectively. Electrode 3 and 4 fabrication was based on use of the precipitation technique of FX cation with tetrakis (4-chlorophenyl) borate and R anions as electroactive materials. Fast and stable Nernstian responses in the range 1 x 10(-2)-1 x 10(-6) M for the 2 drugs over the pH range 5-8 revealed the performance characteristics of these electrodes, which were evaluated according to International Union of Pure and Applied Chemistry recommendations. The method was applied to FX and OX in their pharmaceutical formulations and in human plasma samples. The 4 proposed sensors were found to be specific for the drugs in the presence of up to 60% of their degradation products. Validation of the method according to the quality assurance standards showed suitability of the proposed electrodes for use in the quality control assessment of these drugs. The recoveries for determination of the drugs by the 4 proposed selective electrodes were 99.5 +/- 0.5, 100.0 +/- 0.4, 99.9 +/- 0.4, and 100.1 +/- 0.4% for sensors 1-4, respectively. Statistical comparison between the results obtained by this method and the official method of the drugs was done, and no significant difference found.

  17. PVC membrane, coated-wire, and carbon-paste ion-selective electrodes for potentiometric determination of galantamine hydrobromide in physiological fluids.

    Science.gov (United States)

    Abdel-Haleem, Fatehy M; Saad, Mohamed; Barhoum, Ahmed; Bechelany, Mikhael; Rizk, Mahmoud S

    2018-08-01

    We report on highly-sensitive ion-selective electrodes (ISEs) for potentiometric determining of galantamine hydrobromide (GB) in physiological fluids. Galantamine hydrobromide (GB) was selected for this study due to its previous medical importance for treating Alzheimer's disease. Three different types of ISEs were investigated: PVC membrane electrode (PVCE), carbon-paste electrode (CPE), and coated-wire electrode (CWE). In the construction of these electrodes, galantaminium-reineckate (GR) ion-pair was used as a sensing species for GB in solutions. The modified carbon-paste electrode (MCPE) was prepared using graphene oxide (MCPE-GO) and sodium tetrakis (trifluoromethyl) phenyl borate (MCPE-STFPB) as ion-exchanger. The potentiometric modified CPEs (MCPE-GO and MCPE-STFPB) show an improved performance in term of Nernstian slope, selectivity, response time, and response stability compared to the unmodified CPE. The prepared electrodes PVCE, CWE, CPE, MCPE-GO and MCPE-STFPB show Nernstian slopes of 59.9, 59.5, 58.1, 58.3 and 57.0 mV/conc. decade, and detection limits of 5.0 × 10 -6 , 6.3 × 10 -6 , 8.0 × 10 -6 , 6.0 × 10 -6 and 8.0 × 10 -6  mol L -1 , respectively. The prepared ISEs also show high selectivity against cations (i.e. Na + , K + , NH 4 + , Ca 2+ , Al 3+ , Fe 3+ ), amino acids (i.e. glycine, L-alanine alanine), and sugars (i.e. fructose, glucose, maltose, lactose). The prepared ISEs are applicable for determining GB in spiked serums, urines, and pharmaceutical preparations, using a standard addition and a direct potentiometric method. The fast response time (<10 s), long lifetime (1-5 weeks), reversibility and stability of the measured signals facilitate the application of these sensors for routine analysis of the real samples. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Long-Term Performance of the Laguna de Barlovento Reservoir Water-Proofing using a PVC-P Geo membrane; Impermeabilizacion de la balsa de la Laguna de Barlovento con geomembrana de PVC-P: evolucion a lo largo del tiempo

    Energy Technology Data Exchange (ETDEWEB)

    Blanco Fernandez, M.; Leiro Lopez, A.; Soriano Carrillo, J.; Crespo Mucientes, M.; Zornberg, J.; Aguilar Gonzalez, E.; Rico Arnaiz, G.; Pargada Iglesias, L.

    2014-02-01

    The Laguna de Barlovento reservoir was one of the most important European hydraulic projects at the time of its construction because of its high capacity and challenging location. At the time, the designers decided to waterproof this reservoirs with a geo membrane of plasticized polyvinyl chloride (PVC-P). This paper documents the initial characteristics of the geo membrane and its performance since its installation until 2010. The material characterization includes a comprehensive testing program, the results of which are presented. They include quantification of the geo membrane thickness, amount and nature of plasticizers, tensile properties, fold ability under low temperatures, dynamic impact resistance, puncture resistance, welding strength (both in the manufacturing facility and in the field), as well as the use of techniques involving optical and scanning electron microscopy. In addition, advanced analytical techniques, such as Fourier Transform Infrared Spectroscopy (FTIR), Gas Chromatography (GC) and Mass spectrometry (MS), were used in order to identify the plasticizers used in the geo membrane formulation. Fold ability tests were found to provide early indication of degradation. Results from reflection optical and electron scanning microscopy showed that, after 19 nineteen years of installation, the geo membrane remains in good conditions, particularly on the non-exposed side. (Author)

  19. SYNTHESIS AND CHARACTERIZATION OF POLYIMIDE-ZEOLITE MIXED MATRIX MEMBRANE

    Directory of Open Access Journals (Sweden)

    Budiyono Budiyono

    2012-02-01

    Full Text Available Biogas has become an attractive alternative energy source due to the limitation of energy from fossil. In this study, a new type of mixed matrix membrane (MMM consisting of polyimide-zeolite was synthesized and characterized for biogas purification. The MMM consists of medium concentration of polymer (20% wt polyimide, 80% N-Methyl-2-pyrrolidone (NMP and 25% zeolite 4A in total solid were prepared by a dry/wet phase inversion technique.  The fabricated MMM was characterized using SEM, DSC, TGA and gas permeation. Post treatment coating procedure was also conducted. The research showed that surface coating by 3% silicone rubber toward MMM PI 20% gave the significant effect to improve membrane selectivity. The ideal selectivity for CO2/CH4 separation increased from 0.99 for before coating to 7.9 after coating for PI-Zeolite MMM, respectively. The results suggest that PI-Zeolite MMM with good post treatment procedure will increase the membrane selectivity and permeability with more saver polymer requirement as well as energy saving due to low energy for mixing.

  20. Membrane and inclusion body targeting of lyssavirus matrix proteins.

    Science.gov (United States)

    Pollin, Reiko; Granzow, Harald; Köllner, Bernd; Conzelmann, Karl-Klaus; Finke, Stefan

    2013-02-01

    Lyssavirus matrix proteins (M) support virus budding and have accessory functions that may contribute to host cell manipulation and adaptation to specific hosts. Here, we show that rabies virus (RABV) and European Bat Lyssavirus Type 1 (EBLV-1) M proteins differ in targeting and accumulation at cellular membranes. In contrast to RABV M, EBLV-1 M expressed from authentic EBLV-1 or chimeric RABV accumulated at the Golgi apparatus. Chimeric M proteins revealed that Golgi association depends on the integrity of the entire EBLV-1 M protein. Since RABV and EBLV-1 M differ in the use of cellular membranes for particle formation, differential membrane targeting and transport of M might determine the site of virus production. Moreover, both RABV and EBLV-1 M were for the first time detected within the nucleus and in Negri body-like inclusions bodies. Whereas nuclear M may imply hitherto unknown functions of lyssavirus M in host cell manipulation, the presence of M in inclusion bodies may correlate with regulatory functions of M in virus RNA synthesis. The data strongly support a model in which targeting of lyssavirus M proteins to distinctintracellular sites is a key determinant of diverse features in lyssavirus replication, host adaptation and pathogenesis. © 2012 Blackwell Publishing Ltd.

  1. Engineering of Mixed Matrix Membranes for Water Treatment, Protective Coating and Gas Separation

    KAUST Repository

    Hammami, Mohamed Amen

    2017-01-01

    Mixed Matrix Membranes (MMMs) have received worldwide attention during the last decades. This is due to the fact that the resulting materials can combine the good processability and low cost of polymer membranes with the diverse functionality, high

  2. Physical–chemical properties, separation performance, and fouling resistance of mixed-matrix ultrafiltration membranes

    KAUST Repository

    Hoek, Eric M.V.; Ghosh, Asim K.; Huang, Xiaofei; Liong, Monty; Zink, Jeffrey I.

    2011-01-01

    Herein we report on the formation and characterization of mixed-matrix ultrafiltration (UF) membranes hand-cast by nonsolvent induced phase inversion. We evaluated nanometer-to-micrometer sized inorganic fillers (silver, copper, silica, zeolite, and silver-zeolite) materials with polysulfone (PSf) as the polymeric dispersing matrix. In general, mixed-matrix membranes were rougher, more hydrophilic, and more mechanically robust. Only sub-micron zeolite-PSf mixed-matrix membranes exhibited simultaneous improvements in water permeability and solute selectivity; all other mixed-matrix membranes were more permeable, but less selective due to defects associated with poor polymer-filler binding. Protein and bacterial fouling resistance of mixed-matrix membranes containing silver, zeolite, and silver-zeolite nanoparticles were compared to a low-fouling, poly(acrylonitrile) (PAN) UF membrane. Zeolite and silver containing membranes exhibited better protein fouling resistance (due to higher hydrophilicity), whereas silver and silver-zeolite based membranes produce better bacterial fouling resistance due to antimicrobial properties. Overall, zeolite-PSf and silver exchanged zeolite-PSf membranes offered the best combination of improved permeability, selectivity, and fouling resistance - superior to the commercial PAN membrane. © 2011 Elsevier B.V.

  3. Physical–chemical properties, separation performance, and fouling resistance of mixed-matrix ultrafiltration membranes

    KAUST Repository

    Hoek, Eric M.V.

    2011-12-01

    Herein we report on the formation and characterization of mixed-matrix ultrafiltration (UF) membranes hand-cast by nonsolvent induced phase inversion. We evaluated nanometer-to-micrometer sized inorganic fillers (silver, copper, silica, zeolite, and silver-zeolite) materials with polysulfone (PSf) as the polymeric dispersing matrix. In general, mixed-matrix membranes were rougher, more hydrophilic, and more mechanically robust. Only sub-micron zeolite-PSf mixed-matrix membranes exhibited simultaneous improvements in water permeability and solute selectivity; all other mixed-matrix membranes were more permeable, but less selective due to defects associated with poor polymer-filler binding. Protein and bacterial fouling resistance of mixed-matrix membranes containing silver, zeolite, and silver-zeolite nanoparticles were compared to a low-fouling, poly(acrylonitrile) (PAN) UF membrane. Zeolite and silver containing membranes exhibited better protein fouling resistance (due to higher hydrophilicity), whereas silver and silver-zeolite based membranes produce better bacterial fouling resistance due to antimicrobial properties. Overall, zeolite-PSf and silver exchanged zeolite-PSf membranes offered the best combination of improved permeability, selectivity, and fouling resistance - superior to the commercial PAN membrane. © 2011 Elsevier B.V.

  4. Integrated Water Gas Shift Membrane Reactors Utilizing Novel, Non Precious Metal Mixed Matrix Membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ferraris, John P. [Univ. of Texas-Dallas, Richardson, TX (United States). Dept. of Chemistry

    2013-09-30

    Nanoparticles of zeolitic imidazolate frameworks and other related hybrid materials were prepared by modifying published synthesis procedures by introducing bases, changing stoichiometric ratios, or adjusting reaction conditions. These materials were stable at temperatures >300 °C and were compatible with the polymer matrices used to prepare mixed- matrix membranes (MMMs). MMMs tested at 300 °C exhibited a >30 fold increase in permeability, compared to those measured at 35 °C, while maintaining H2/CO2 selectivity. Measurements at high pressure (up to 30 atm) and high temperature (up to 300 °C) resulted in an increase in gas flux across the membrane with retention of selectivity. No variations in permeability were observed at high pressures at either 35 or 300 °C. CO2-induced plasticization was not observed for Matrimid®, VTEC, and PBI polymers or their MMMs at 30 atm and 300 °C. Membrane surface modification by cross-linking with ethanol diamine resulted in an increase in H2/CO2 selectivity at 35 °C. Spectrometric analysis showed that the cross-linking was effective to temperatures <150 °C. At higher temperatures, the cross-linked membranes exhibit a H2/CO2 selectivity similar to the uncross-linked polymer. Performance of the polybenzimidazole (PBI) hollow fibers prepared at Santa Fe Science and Technology (SFST, Inc.) showed increased flux and selectivity at 300 °C, which is comparable to a flat PBI membrane. A water-gas shift reactor has been built and currently being optimized for testing under DOE conditions.

  5. Chalk effect on PVC cross-linking under irradiation

    International Nuclear Information System (INIS)

    Chudinova, V.V.; Guzeev, V.V.; Mozzhukhin, V.B.; Pomerantseva, Eh.G.; Nozrina, F.D.; Zhil'tsov, V.V.; Zubov, V.P.

    1994-01-01

    Effect of nonmodified and modified chalk on curing degree of polymer matrix was studied under-irradiation of PVC-compositions. Films of the compositions (100 mass part 7 PVC, 0-100 mas.part of chalk, 2.5 - lead sulfate, 1.5 - lead stearate and 0.3 - glycerin) were irradiated up to absorbed dose 0.1 MGy in an inert medium. Content of gel-fraction after boiling in THF was determined with use of IR spectroscopy. It was established, that intensive dehydrochlorination and polymer curing took place on chalk particle surface. Network fixed strongly chalk particles. However, chalk inhibited processes of dehydrochlorination and PVC curing, increasing amount of noncured PVC in polymer matrix

  6. An investigation on polymeric blend mixed matrix membranes of ...

    African Journals Online (AJOL)

    Polymeric membranes have been vastly used for gas separation purposes however they have an upper-bound trade off problem which is the reason why this research work is focusing on inorganic filler added to polymer blend membranes to enhance the selectivity and permeability of the resulted membranes. Different ...

  7. Membranes having aligned 1-D nanoparticles in a matrix layer for improved fluid separation

    Science.gov (United States)

    Revanur, Ravindra; Lulevich, Valentin; Roh, Il Juhn; Klare, Jennifer E.; Kim, Sangil; Noy, Aleksandr; Bakajin, Olgica

    2015-12-22

    Membranes for fluid separation are disclosed. These membranes have a matrix layer sandwiched between an active layer and a porous support layer. The matrix layer includes 1-D nanoparticles that are vertically aligned in a porous polymer matrix, and which substantially extend through the matrix layer. The active layer provides species-specific transport, while the support layer provides mechanical support. A matrix layer of this type has favorable surface morphology for forming the active layer. Furthermore, the pores that form in the matrix layer tend to be smaller and more evenly distributed as a result of the presence of aligned 1-D nanoparticles. Improved performance of separation membranes of this type is attributed to these effects.

  8. Mixed Matrix Silicone and Fluorosilicone/Zeolite 4A Membranes for Ethanol Dehydration by Pervaporation

    Science.gov (United States)

    The ability of homogeneous and mixed matrix membranes prepared using standard silicone rubber, poly(dimethylsiloxane) (PDMS), and fluorosilicone rubber, poly(trifluoropropylmethylsiloxane) (PTFPMS), to dehydrate ethanol by pervaporation was evaluated. Although PDMS is generally c...

  9. Carbon dioxide selective mixed matrix composite membrane containing ZIF-7 nano-fillers

    KAUST Repository

    Li, Tao; Pan, Yichang; Peinemann, Klaus-Viktor; Lai, Zhiping

    2013-01-01

    Mixed matrix materials made from selective inorganic fillers and polymers are very attractive for the manufacturing of gas separation membranes. But only few of these materials could be manufactured into high-performance asymmetric or composite

  10. FABRICATION AND CHARACTERIZATION OF POLYIMIDE/POLYETHERSULFONE-FUMED SILICA MIXED MATRIX MEMBRANE FOR GAS SEPARATION

    Directory of Open Access Journals (Sweden)

    A. F. Ismail

    2012-01-01

    Full Text Available This study is performed primarily to investigate the feasibility of fumed silica as inorganic material towards gas separation performance of mixed matrix membrane. In this study, polyimide/polyethersulfone (PES-fumed silica mixed matrix membranes were casted using dry/wet technique. The results from the FESEM, DSC and FTIR analysis confirmed that the structure and physical properties of membrane is influenced by inorganic filler. FESEM’s cross-section view indicated good compatibility between polymer and fumed silica for all of range fumed silica used in this study. The gas separation performance of the mixed matrix membranes with fumed silica were relatively higher compared to that of the neat PI/PES membrane. PI/PES-fumed silica 5 wt% yielded significant selectivity enhancement of 7.21 and 40.47 for O2/N2, and CO2/CH4, respectively.

  11. Zinc(II PVC-based membrane sensor based on 5,6-benzo-4,7,13,16,21,24- hexaoxa-1,10-diazabicyclo[8,8,8]hexacos-5-ene

    Directory of Open Access Journals (Sweden)

    Zamani Hassan Ali

    2006-01-01

    Full Text Available The 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacos-5-ene (BHDE was used as an excellent ionophore in construction of a Zn(II PVC-based membrane sensor. The best performance was obtained with a membrane composition of 30% poly(vinyl chloride, 64.5% nitrobenzen (NB, 2.5% BHDE and 3% sodium tetraphenylborate (NaTPB. This sensor shows very good selectivity and sensitivity towards zinc ion over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The sensor revealed a great enhancement in selectivity coefficients for zinc ions, in comparison to the previously reported zinc sensors. The proposed sensor exhibits a Nernstian behavior (with slope of 29.1 ? 0.4 mV per decade over a wide concentration range (1.0 10-6-1.0 10-1 mol L-1 with a detection limit of 6.3 x10-7 mol L-1 (41.2 ng mL-1. It shows relatively fast response time, in the whole concentration range (< 10s, and can be used for at least 10 weeks in a pH range of 2.8-7.3. The proposed sensor was successfully used in direct determination of zinc ions in wastewater of industrial zinc electroplating companies, and also as an indicator electrode in titration with EDTA.

  12. Nanoclay embedded mixed matrix PVDF nanocomposite membrane: Preparation, characterization and biofouling resistance

    Energy Technology Data Exchange (ETDEWEB)

    Rajabi, Hamid [Membrane Research Centre, Department of Chemical Engineering, Razi University, Tagh Bostan, 67149 Kermanshah (Iran, Islamic Republic of); Department of Civil Engineering, Razi University, 67149 Kermanshah (Iran, Islamic Republic of); Ghaemi, Negin, E-mail: negin_ghaemi@kut.ac.ir [Department of Chemical Engineering, Kermanshah University of Technology, 67178 Kermanshah (Iran, Islamic Republic of); Madaeni, Sayed S. [Membrane Research Centre, Department of Chemical Engineering, Razi University, Tagh Bostan, 67149 Kermanshah (Iran, Islamic Republic of); Daraei, Parisa [Department of Chemical Engineering, Kermanshah University of Technology, 67178 Kermanshah (Iran, Islamic Republic of); Khadivi, Mohammad Ali [Friedrich-Alexander University, Erlangen-Nuremberg, Egerland Strasse 3, D-91058 Erlangen (Germany); Falsafi, Monir [Department of Chemistry, Faculty of Science, Razi University, 67149 Kermanshah (Iran, Islamic Republic of)

    2014-09-15

    Highlights: • Nanocomposite membranes were prepared by addition of OMMT to PVDF membrane. • Addition of nanoclay considerably increased the hydrophilicity of PVDF membrane. • Nanocomposite membranes had higher water flux and antifouling properties. • Fouling of membranes blended with nanoclay (<4 wt.%) reduced. - Abstract: In this paper, nanocomposite PVDF/nanoclay membranes were prepared with addition of different concentrations of organically modified montmorillonite (OMMT) into the polymeric casting solution using combination of solution dispersion and phase inversion methods. Membranes were characterized by use of X-ray diffraction (XRD), water contact angle, scanning electron microscopy (SEM) and atomic force microscopy (AFM), and their performances were evaluated in terms of pure water flux and fouling parameters. The surface hydrophilicity of all nanocomposites markedly improved compared to nascent PVDF. In addition, XRD patterns revealed the formation of intercalated layers of mineral clays in PVDF matrix. SEM and AFM images showed that addition of OMMT resulted in nanocomposite membranes with thinner skin layer and higher porosity rather than PVDF membranes. Pure water flux of PVDF/OMMT membranes increased significantly (particularly for fabricated membranes by 4 and 6 wt.% OMMT) compared to that of PVDF membrane. Moreover, nanocomposite membranes showed the elevated antifouling properties, and flux recovery of nascent PVDF membranes increased from 51 to 72% with addition of 2 wt.% OMMT nanoparticles. These nanocomposite membranes also offered a remarkable reusability and durability against biofouling.

  13. Nanoclay embedded mixed matrix PVDF nanocomposite membrane: Preparation, characterization and biofouling resistance

    International Nuclear Information System (INIS)

    Rajabi, Hamid; Ghaemi, Negin; Madaeni, Sayed S.; Daraei, Parisa; Khadivi, Mohammad Ali; Falsafi, Monir

    2014-01-01

    Highlights: • Nanocomposite membranes were prepared by addition of OMMT to PVDF membrane. • Addition of nanoclay considerably increased the hydrophilicity of PVDF membrane. • Nanocomposite membranes had higher water flux and antifouling properties. • Fouling of membranes blended with nanoclay (<4 wt.%) reduced. - Abstract: In this paper, nanocomposite PVDF/nanoclay membranes were prepared with addition of different concentrations of organically modified montmorillonite (OMMT) into the polymeric casting solution using combination of solution dispersion and phase inversion methods. Membranes were characterized by use of X-ray diffraction (XRD), water contact angle, scanning electron microscopy (SEM) and atomic force microscopy (AFM), and their performances were evaluated in terms of pure water flux and fouling parameters. The surface hydrophilicity of all nanocomposites markedly improved compared to nascent PVDF. In addition, XRD patterns revealed the formation of intercalated layers of mineral clays in PVDF matrix. SEM and AFM images showed that addition of OMMT resulted in nanocomposite membranes with thinner skin layer and higher porosity rather than PVDF membranes. Pure water flux of PVDF/OMMT membranes increased significantly (particularly for fabricated membranes by 4 and 6 wt.% OMMT) compared to that of PVDF membrane. Moreover, nanocomposite membranes showed the elevated antifouling properties, and flux recovery of nascent PVDF membranes increased from 51 to 72% with addition of 2 wt.% OMMT nanoparticles. These nanocomposite membranes also offered a remarkable reusability and durability against biofouling

  14. Structure and performance of ZnO/PVC nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Elashmawi, I.S., E-mail: islam_shukri2000@yahoo.co [Spectroscopy department, Physics division, National Research Centre, Dokki (Egypt); Hakeem, N.A. [Spectroscopy department, Physics division, National Research Centre, Dokki (Egypt); Marei, L.K.; Hanna, F.F. [Faculty of Petroleum and Mining Engineering, Suez Canal University, Suez (Egypt)

    2010-10-01

    ZnO/PVC nanocomposites films have been prepared by the solvent casting method and investigated by various techniques. All results show good dispersion of ZnO nanoparticles in the polymeric matrix. XRD revealed that pure PVC films are partially crystalline with hallow peak but ZnO nanoparticles have wurtzite structure and the nanocomposite films were almost the same as those of ZnO with decrease in the degree of crystallization, causing increase in the amorphous region. FT-IR presented the same spectra for nanocomposites in the wavenumber range 700-3100 cm{sup -1}, weak band located at 500-700 cm{sup -1},which can be attributed to stretching of Zn---O bond and an increase of the bending band of O-H at 1631 cm{sup -1} was observed. The surface of the films was analyzed by SEM, which becomes rough with some small aggregates compared with pure PVC with good distribution in the entire surface region with bright spots. TEM revealed a regular crystalline lattice superimposed on an amorphous background due to carbon support and PVC matrix and the structure of these particles is hexagonal. In addition, the nanocomposites films have higher glass transition temperature, specific heat and thermal stability relative to those of pure PVC because of strong interaction among ZnO nanoparticles and PVC.

  15. Preparation of mixed matrix adsorber membranes for protein recovery

    NARCIS (Netherlands)

    Avramescu, M.E.; Girones nogue, Miriam; Borneman, Zandrie; Wessling, Matthias

    2003-01-01

    This paper presents a generic technology allowing the incorporation of functional entities into a porous substrate. Various ion exchange particles were incorporated into an ethylene vinyl alcohol (EVAL) copolymer porous matrix by an immersion phase separation process and a heterogeneous matrix,

  16. Zeolite-imidazolate framework (ZIF-8) membrane synthesis on a mixed-matrix substrate.

    Science.gov (United States)

    Barankova, Eva; Pradeep, Neelakanda; Peinemann, Klaus-Viktor

    2013-10-21

    A thin, dense, compact and hydrogen selective ZIF-8 membrane was synthesized on a polymer/metal oxide mixed-matrix support by a secondary seeding method. The new concept of incorporating ZnO particles into the support and PDMS coating of the ZIF-8 layer is introduced to improve the preparation of ZIF-polymer composite membranes.

  17. A metal ion charged mixed matrix membrane for selective adsorption of hemoglobin

    NARCIS (Netherlands)

    Tetala, K.K.R.; Skrzypek, K.; Levisson, M.; Stamatialis, D.F.

    2013-01-01

    In this work, we developed a mixed matrix membrane by incorporating 20–40 µm size iminodiacetic acid modified immobeads within porous Ethylene vinyl alcohol (EVAL) polymer matrix. The MMM were charged with copper ions for selective adsorption of bovine hemoglobin in presence of bovine serum albumin.

  18. A metal ion charged mixed matrix membrane for selective adsorption of hemoglobin

    NARCIS (Netherlands)

    Tetala, K.K.R.; Skrzypek, Katarzyna; Levisson, M.; Stamatialis, Dimitrios

    2013-01-01

    In this work, we developed a mixed matrix membrane by incorporating 20–40 μm size iminodiacetic acid modified immobeads within porous Ethylene vinyl alcohol (EVAL) polymer matrix. The MMM were charged with copper ions for selective adsorption of bovine hemoglobin in presence of bovine serum albumin.

  19. Downregulation of membrane type-matrix metalloproteinases in the inflamed or injured central nervous system

    DEFF Research Database (Denmark)

    Toft-Hansen, Henrik; Babcock, Alicia A; Millward, Jason M

    2007-01-01

    BACKGROUND: Matrix metalloproteinases (MMPs) are thought to mediate cellular infiltration in central nervous system (CNS) inflammation by cleaving extracellular matrix proteins associated with the blood-brain barrier. The family of MMPs includes 23 proteinases, including six membrane type-MMPs (M...

  20. Highly scalable ZIF-based mixed-matrix hollow fiber membranes for advanced hydrocarbon separations

    KAUST Repository

    Zhang, Chen

    2014-05-29

    ZIF-8/6FDA-DAM, a proven mixed-matrix material that demonstrated remarkably enhanced C3H6/C3H8 selectivity in dense film geometry, was extended to scalable hollow fiber geometry in the current work. We successfully formed dual-layer ZIF-8/6FDA-DAM mixed-matrix hollow fiber membranes with ZIF-8 nanoparticle loading up to 30 wt % using the conventional dry-jet/wet-quench fiber spinning technique. The mixed-matrix hollow fibers showed significantly enhanced C3H6/C3H8 selectivity that was consistent with mixed-matrix dense films. Critical variables controlling successful formation of mixed-matrix hollow fiber membranes with desirable morphology and attractive transport properties were discussed. Furthermore, the effects of coating materials on selectivity recovery of partially defective fibers were investigated. To our best knowledge, this is the first article reporting successful formation of high-loading mixed-matrix hollow fiber membranes with significantly enhanced selectivity for separation of condensable olefin/paraffin mixtures. Therefore, it represents a major step in the research area of advanced mixed-matrix membranes. © 2014 American Institute of Chemical Engineers.

  1. Investigation of Electrochemical and Morphological Properties of Mixed Matrix Polysulfone-Silica Anion Exchange Membrane

    Directory of Open Access Journals (Sweden)

    Khoiruddin

    2016-02-01

    Full Text Available Mixed matrix anion exchange membranes (AEMs were synthesized using dry-wet phase inversion. The casting solutions were prepared by dispersing finely ground anion-exchange resin particles in N,N-dimethylacetamide (DMAc solutions of polysulfone (PSf. Subsequently, nanosilica particles were introduced into the membranes. The results show that evaporation time (tev and solution composition contributed to membrane properties formation. A longer tev produces membranes with reduced void fraction inside the membranes, thus the amount of water adsorbed and membrane conductivity are reduced. Meanwhile, the permselectivity was improved by increasing tev, since a longer tev produces membranes with a narrower channel for ion migration and more effective Donnan exclusion. The incorporation of 0.5 %-wt nanosilica particles into the polymer matrix led to conductivity improvement (from 2.27 to 3.41 mS.cm-1. This may be associated with additional pathway formation by hydroxyl groups on the silica surface that entraps water and assists ion migration. However, at further silica loading (1.0 and 1.5 %-wt, these properties decreased (to 1.9 and 1.4 mS.cm-1 respectively, which attributed to inaccessibility of ion-exchange functional groups due to membrane compactness. It was found from the results that nanosilica contributes to membrane formation (increases casting solution viscosity then reduces void fraction and membrane functional group addition (provides hydroxyl groups.

  2. M(atrix) theory on an orbifold and twisted membrane

    International Nuclear Information System (INIS)

    Kim, N.

    1997-01-01

    M(atrix) theory on an orbifold and classical two-branes therein are studied with particular emphasis on heterotic M(atrix) theory on S 1 / Z 2 relevant to strongly coupled heterotic and dual type IA string theories. By analyzing the orbifold condition on Chan-Paton factors, we show that three choices of gauge group are possible for heterotic M(atrix) theory: SO(2N), SO(2N+1) or USp(2N). By examining the area-preserving diffeomorphism that underlies the M(atrix) theory, we find that each choice of gauge group restricts the possible topologies of two-branes. The result suggests that only the choice of SO(2N) or SO(2N+1) allows open two-branes, and hence, is relevant to heterotic M(atrix) theory. We show that the requirement of both local vacuum energy cancellation and of world-sheet anomaly cancellation of the resulting heterotic string identifies supersymmetric twisted sector spectra with sixteen fundamental representation spinors from each of the two fixed points. Twisted open and closed two-brane configurations are obtained in the large N limit. (orig.)

  3. Mixed Matrix Composite Membranes Containing POSS Molecules for Carbon Dioxide Removal Application

    KAUST Repository

    Rini, Eki Listya

    2011-05-10

    CO2 removal by membrane processes is considerably potential for several applications such as natural gas and synthesis gas purification, enhanced oil recovery application, and carbon dioxide capture in combat against global warming. Dense polymeric membranes are commonly utilized for these type of gas separation applications. Nevertheless, the intrinsic properties of dense polymeric membranes, which commonly characterize by the low gas permeability versus high gas selectivity trade–off or vice versa, is less desirable. In order to meet the increased demand of CO2 removal, a strategy to improve the gas separation performance of a polymeric membrane is investigated in this study. With this regard, mixed matrix membranes in which inorganic non porous fillers are incorporated into a polymeric matrix were prepared to achieve the aforementioned objective. The mixed matrix membranes were prepared from Pebax® block copolymers and PEG POSS® molecules. These hybrid membranes were formed as both dense and multilayer composite membranes. The dense transparent membranes with well–dispersed fillers could be obtained by variation of the solvent mixture. The DSC analyses showed that incorporation of PEG POSS® into Pebax® matrix altered the thermal properties of the matrix. The multilayer composite membranes were then prepared from a PTMSP gutter layer deposited on a PAN porous support and an adjacent hybrid Pebax®/PEG POSS® as the top layer. These hybrid multilayer composite membranes exhibited an enhanced CO2 selectiv4 ity by a factor of two relative to the pure Pebax®. In these hybrid systems, the CO2 separation was presumably enhanced by the high ether oxides content from PEG POSS® that has high affinities for CO2. For particular composition of Pebax® and PEG POSS® concentrations, the PTMSP gutter layer harnessed the CO2 selectivity without losing the CO2 permeation rate. At the same time, these membrane, however, suffered severe adhesion between the gutter layer

  4. A reciclagem de PVC no Brasil Recycling of PVC Brazil

    Directory of Open Access Journals (Sweden)

    Ana Magda Piva

    1999-12-01

    Full Text Available Esta pesquisa discute as possibilidades práticas da reciclagem de PVC. Na reciclagem de polímeros, a do PVC representa uma importante parcela. PVC é um polímero que é usado em uma ampla faixa de produtos: filmes, fios, cabos, em compostos para uma variedade de formas. A reciclagem é uma técnica vantajosa, capaz de reproduzir as propriedades do polímero original, no polímero reciclado e isto em condições razoavelmente econômicas. A tecnologia brasileira, em relação a produtos reciclados, apresenta algumas diferenças da reciclagem tradicional. Métodos alternativos de reciclagens são necessários se os processos não desvalorizam os resultados finais.This research discuss the practical possibilities of recycling PVC. PVC, plays an important part in the recycleability of polymers; PVC is a polymer which is used in a very wide range of products -films, wire, cabes, in compounds for a variety of forms. Recycling is only worthwile, one is able to reproduce the original polymer properties in the polymer being recycled, and this under reasonable economics conditions. The brasilian technology that produces recycled products is a little different from the tradicional recycling. Therefore alternative methods to recycle are needed if recycling is not to devalue the end results.

  5. Rat hair follicle dermal papillae have an extracellular matrix containing basement membrane components

    DEFF Research Database (Denmark)

    Couchman, J R

    1986-01-01

    , to be replaced by synthesis of other components including type I and III collagens. It seems likely therefore that the dermal papilla cells in vivo synthesize a basement membrane type of extracellular matrix, although a contribution from epithelial, and in some cases capillary endothelial, cells cannot be ruled......Dermal papillae are small mesenchymally derived zones at the bases of hair follicles which have an important role in hair morphogenesis in the embryo and control of the hair growth cycle in postnatal mammals. The cells of the papilla are enmeshed in a dense extracellular matrix which undergoes...... extensive changes in concert with the hair cycle. Here it is shown that this matrix in anagen pelage follicles of postnatal rats contains an abundance of basement membrane components rather than dermal components such as interstitial collagens. In particular, type IV collagen, laminin, and basement membrane...

  6. Progress on Incorporating Zeolites in Matrimid®5218 Mixed Matrix Membranes towards Gas Separation

    Directory of Open Access Journals (Sweden)

    Roberto Castro-Muñoz

    2018-06-01

    Full Text Available Membranes, as perm-selective barriers, have been widely applied for gas separation applications. Since some time ago, pure polymers have been used mainly for the preparation of membranes, considering different kinds of polymers for such preparation. At this point, polyimides (e.g., Matrimid®5218 are probably one of the most considered polymers for this purpose. However, the limitation on the performance relationship of polymeric membranes has promoted their enhancement through the incorporation of different inorganic materials (e.g., zeolites into their matrix. Therefore, the aim of this work is to provide an overview about the progress of zeolite embedding in Matrimid®5218, aiming at the preparation of mixed matrix membranes for gas separation. Particular attention is paid to the relevant experimental results and current findings. Finally, we describe the prospects and future trends in the field.

  7. Zeolite-imidazolate framework (ZIF-8) membrane synthesis on a mixed-matrix substrate

    KAUST Repository

    Barankova, Eva; Neelakanda, Pradeep; Peinemann, Klaus-Viktor

    2013-01-01

    A thin, dense, compact and hydrogen selective ZIF-8 membrane was synthesized on a polymer/metal oxide mixed-matrix support by a secondary seeding method. The new concept of incorporating ZnO particles into the support and PDMS coating of the ZIF-8 layer is introduced to improve the preparation of ZIF-polymer composite membranes. © 2013 The Royal Society of Chemistry.

  8. Monitoring of praseodymium(III) ions in aqueous solutions, soil and sediment samples by a PVC membrane sensor based on a furan-triazole derivative

    Energy Technology Data Exchange (ETDEWEB)

    Pourjavid, Mohammad Reza [Islamic Azad University, Tehran (Iran, Islamic Republic of). Dept. of Medicinal Chemistry. Nuclear Science and Technology Research Institute; Rezaee, Mohammad; Hosseini, Majid Haji [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Razavi, Taherehsadat, E-mail: pourjavid@gmail.com [Research Institute of Petroleum Industry, Tehran (Iran, Islamic Republic of). Instrumental Analysis Dept.

    2012-07-01

    A furan-triazole derivative has been explored as an ionophore for preparation of a highly selective Pr(III) membrane sensor. The proposed sensor exhibits a Nernstian response for Pr(III) activity over a wide concentration range with a detection limit of 5.2 x 10{sup -8}M. Its response is independent of pH of the solution in the range 3.0-8.8 and offers the advantages of fast response time. To investigate the analytical applicability of the sensor, it was applied successfully as an indicator electrode in potentiometric titration of Pr(III) solution and also in the direct and indirect determination of trace Pr(III) ions in some samples. (author)

  9. Studies on carboxylated graphene oxide incorporated polyetherimide mixed matrix ultrafiltration membranes

    Energy Technology Data Exchange (ETDEWEB)

    Kaleekkal, Noel Jacob, E-mail: noeljacob89@gmail.com [Membrane Laboratory, Department of Chemical Engineering, ACT, Anna University, Chennai, 600025 (India); Thanigaivelan, A., E-mail: thanichemstar@gmail.com [Membrane Laboratory, Department of Chemical Engineering, ACT, Anna University, Chennai, 600025 (India); Rana, Dipak, E-mail: rana@uottawa.ca [Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur Private, Ottawa, Ontario, K1N 6N5 (Canada); Mohan, D., E-mail: mohantarun@gmail.com [Membrane Laboratory, Department of Chemical Engineering, ACT, Anna University, Chennai, 600025 (India)

    2017-01-15

    In this work the graphene oxide prepared by the modified Hummers’ method was effectively carboxylated. These carboxylated graphene oxide (c-GO) microsheets was characterized by X-ray diffraction analysis, Raman shift, zeta potential, and their morphology was observed using a high resolution scanning/transmission electron microscopy. Polyetherimide mixed matrix membranes (MMMs) were fabricated by the non-solvent induced phase separation technique with varying concentration of this microsheet. The presence of these microsheets on the membrane surface was confirmed by Fourier transform infrared spectroscopy, Raman spectroscopy and could also be confirmed visually by optical images. The membranes were further characterized; they showed a greater water flux, higher porosity, and sufficient thermal stability. Incorporation of these microsheets improved the hydrophilicity of the membrane confirmed by the lower contact angle values, which in turn explained the lower interfacial free energy, the increase in work of adhesion, the higher solid-vapor free energy and the spreading coefficient. Membranes loaded with 0.3 wt% of c-GO showed a flux recovery of 94% and only a small flux decline even after 180 min of filtration of humic acid (HA) solution. The efficiency of these membranes in removal of HA, toxic metal ions was also investigated. The bacterial anti-adhesion property of c-GO in the membranes was also explored using Escherichia coli, as a model bio-foulant. The charge of the microsheets and their unique architecture imparts higher hydrophilicity and greater fouling resistance along with improved permeation flux when incorporated into the polymer matrix. - Highlights: • Novel membranes by incorporating carboxylated GO into polyetherimide matrix. • Modified membranes exhibited greater porosity, flux and high humic acid rejection. • Nanoplatelets improved the flux recovery ratio to >94%. • Liquid phase polymer based retention utilized for toxic heavy metal

  10. PVC-Membrane Potentiometric Electrochemical Sensor Based on 2-(4-Oxopentan-2-ylideneaminoisoindoline-1,3-dione for Selective Determination of Holmium(III

    Directory of Open Access Journals (Sweden)

    Hassan Ali Zamani

    2011-01-01

    Full Text Available 2-(4-Oxopentan-2-ylideneamino isoindoline-1,3-dione (OID was found to be a suitable neutral ionophore in the fabrication of a highly selective Ho3+ membrane sensor. The electrode has a near-Nernstian slope of 19.6±0.5 mV per decade with a wide concentration range between 1.0×10-6 and 1.0×10-2 mol/L in the pH range of 3.5–8.8, having a fast response time (∼5 s and a detection limit of 5.8×10-7 mol/L. This electrode presented very good selectivity and sensitivity towards the Ho3+ ions over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The practical utility of the electrode has been demonstrated by its use as an indicator electrode for the potentiometric titration of a Ho3+ solution with EDTA and for the determination of Ho3+ ions concentration in mixtures of two and three different ions.

  11. Factors affecting alcohol-water pervaporation performance of hydrophobic zeolite-silicone rubber mixed matrix membranes

    Science.gov (United States)

    Mixed matrix membranes (MMMs) consisting of ZSM-5 zeolite particles dispersed in silicone rubber exhibited ethanol-water pervaporation permselectivities up to 5 times that of silicone rubber alone and 3 times higher than simple vapor-liquid equilibrium (VLE). A number of conditi...

  12. Mixed matrix membranes based on polyamide/montmorillonite for pervaporation of methanol-toluene mixture

    Czech Academy of Sciences Publication Activity Database

    Avagimova, N.; Polotskaya, G.; Saprykina, N.; Toikka, A.; Pientka, Zbyněk

    2013-01-01

    Roč. 48, č. 17 (2013), s. 2513-2523 ISSN 0149-6395 R&D Projects: GA ČR GA104/09/1165 Institutional support: RVO:61389013 Keywords : membranes * pervaporation * mixed matrix Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.200, year: 2013

  13. Pore formation mechanism of porous poly(DL-lactic acid) matrix membrane

    Energy Technology Data Exchange (ETDEWEB)

    Phaechamud, Thawatchai, E-mail: tphaechamud011@yahoo.com; Chitrattha, Sasiprapa, E-mail: sasi_toey@hotmail.com

    2016-04-01

    Porous PLA structure has been widely used in cell transplantation, drug carrier and wound dressing. The porous structure can be controlled depending on the choice of the polymer, solvent, nonsolvent and preparation parameters. In this study, the porous PLA matrix membranes were prepared by adding PEG 400 in PLA solution using dichloromethane (DCM) as solvent prior to casting. The influence of other liquids as co-solvent on pore formation and the structural change during membrane formation were evaluated. The co-solvents affected both porous topography and mechanical properties of PLA membrane. The porous matrix were produced when the non-solvent of PLA was used as co-solvent. Cryo-SEM micrographs revealed that PEG 400 still remained in the PLA porous matrix membrane. From the tracking of the structural change during film formation, the PLA–PEG solution changed into porous structure by liquid liquid phase separation and solidification processes, respectively. Thermogravimetric analysis revealed that PLA–PEG in DCM solution exhibited the two-step of weight loss, the first step occurred from DCM evaporation and the second step occurred from the degradation of PLA–PEG matrix. The liquid–liquid phase separation and solidification started when the amount of DCM was higher than PEG 400 for 2.67 folds and DCM amount was equal to that of PEG 400, respectively. These results could clarify the pore formation mechanism of porous PLA membrane and will be useful for the further investigation and application. - Highlights: • Pore formation mechanism of PLA matrix membrane inducing by PEG 400 addition was investigated. • Cryo-scanning electron microscopy revealed the embedded PEG 400 in matrix membrane. • Tracking of structural change during membrane formation with stereomicroscope and thermogravimetric analysis could explain the pore formation mechanism. • Liquid-liquid phase separation of PLA-PEG 400 solution started when the amount of dichloromethane remained 2

  14. Pore formation mechanism of porous poly(DL-lactic acid) matrix membrane

    International Nuclear Information System (INIS)

    Phaechamud, Thawatchai; Chitrattha, Sasiprapa

    2016-01-01

    Porous PLA structure has been widely used in cell transplantation, drug carrier and wound dressing. The porous structure can be controlled depending on the choice of the polymer, solvent, nonsolvent and preparation parameters. In this study, the porous PLA matrix membranes were prepared by adding PEG 400 in PLA solution using dichloromethane (DCM) as solvent prior to casting. The influence of other liquids as co-solvent on pore formation and the structural change during membrane formation were evaluated. The co-solvents affected both porous topography and mechanical properties of PLA membrane. The porous matrix were produced when the non-solvent of PLA was used as co-solvent. Cryo-SEM micrographs revealed that PEG 400 still remained in the PLA porous matrix membrane. From the tracking of the structural change during film formation, the PLA–PEG solution changed into porous structure by liquid liquid phase separation and solidification processes, respectively. Thermogravimetric analysis revealed that PLA–PEG in DCM solution exhibited the two-step of weight loss, the first step occurred from DCM evaporation and the second step occurred from the degradation of PLA–PEG matrix. The liquid–liquid phase separation and solidification started when the amount of DCM was higher than PEG 400 for 2.67 folds and DCM amount was equal to that of PEG 400, respectively. These results could clarify the pore formation mechanism of porous PLA membrane and will be useful for the further investigation and application. - Highlights: • Pore formation mechanism of PLA matrix membrane inducing by PEG 400 addition was investigated. • Cryo-scanning electron microscopy revealed the embedded PEG 400 in matrix membrane. • Tracking of structural change during membrane formation with stereomicroscope and thermogravimetric analysis could explain the pore formation mechanism. • Liquid-liquid phase separation of PLA-PEG 400 solution started when the amount of dichloromethane remained 2

  15. Nano-ZnO embedded mixed matrix polyethersulfone (PES) membrane: Influence of nanofiller shape on characterization and fouling resistance

    International Nuclear Information System (INIS)

    Rajabi, Hamid; Ghaemi, Negin; Madaeni, Sayed S.; Daraei, Parisa; Astinchap, Bandar; Zinadini, Sirus; Razavizadeh, Sayed Hossein

    2015-01-01

    Graphical abstract: - Highlights: • ZnO nanofillers with different shape (nanorod and nanoparticle) were synthesized. • Mixed matrix PES membranes were fabricated by different concentrations of nanofillers. • Embedding nanofillers affected on morphology and hydrophilicity of PES membranes. • Nanorod MM membranes revealed the highest water flux and antifouling characteristic. • ZnO nanorod-embedded membrane showed an acceptable reusability and durability. - Abstract: Two different kinds of nano-ZnO (nanoparticle and nanorod) were synthesized, characterized, and embedded in a PES membrane matrix to investigate the effects of a nanofiller shape on the mixed matrix membrane characteristics and the antifouling capability. The mixed matrix membranes were fabricated by mixing different amounts of nanofillers with dope solution followed by a phase inversion precipitation technique. The effect of the shape of the embedded nanofillers on the morphology and performance of the fabricated membranes was studied in terms of pure water flux, fouling resistance, hydrophilicity, surface, and bulk morphology by means of permeation tests, milk powder solution filtration, water contact angle and porosity measurements, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. Water flux of the mixed matrix membranes significantly improved after the addition of both types of ZnO nanofillers due to a higher hydrophilicity and porosity of the prepared membranes. The water contact angle measurements confirmed the increased hydrophilicity of the modified membranes, particularly in the ZnO nanorod mixed membranes. Fouling resistance of the membranes assessed by powder milk solution filtration revealed that 0.1 wt% ZnO nanorod membrane has the best antifouling property. The prepared mixed matrix membranes embedded with 0.1 wt% of both types of ZnO nanofillers showed a remarkable durability and reusability during the filtration tests; however, the best

  16. Nano-ZnO embedded mixed matrix polyethersulfone (PES) membrane: Influence of nanofiller shape on characterization and fouling resistance

    Energy Technology Data Exchange (ETDEWEB)

    Rajabi, Hamid [Membrane Research Centre, Department of Chemical Engineering, Razi University, Tagh Bostan, 67149 Kermanshah (Iran, Islamic Republic of); Department of Civil Engineering, Razi University, 67149 Kermanshah (Iran, Islamic Republic of); Ghaemi, Negin, E-mail: negin_ghaemi@kut.ac.ir [Department of Chemical Engineering, Kermanshah University of Technology, 67178 Kermanshah (Iran, Islamic Republic of); Madaeni, Sayed S. [Membrane Research Centre, Department of Chemical Engineering, Razi University, Tagh Bostan, 67149 Kermanshah (Iran, Islamic Republic of); Daraei, Parisa [Department of Chemical Engineering, Kermanshah University of Technology, 67178 Kermanshah (Iran, Islamic Republic of); Astinchap, Bandar [Physics Department, Faculty of Science, University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Zinadini, Sirus [Water and Wastewater Research Center (WWRC), Department of Applied Chemistry, Faculty of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Razavizadeh, Sayed Hossein [Department of Chemical Engineering, Kermanshah University of Technology, 67178 Kermanshah (Iran, Islamic Republic of)

    2015-09-15

    Graphical abstract: - Highlights: • ZnO nanofillers with different shape (nanorod and nanoparticle) were synthesized. • Mixed matrix PES membranes were fabricated by different concentrations of nanofillers. • Embedding nanofillers affected on morphology and hydrophilicity of PES membranes. • Nanorod MM membranes revealed the highest water flux and antifouling characteristic. • ZnO nanorod-embedded membrane showed an acceptable reusability and durability. - Abstract: Two different kinds of nano-ZnO (nanoparticle and nanorod) were synthesized, characterized, and embedded in a PES membrane matrix to investigate the effects of a nanofiller shape on the mixed matrix membrane characteristics and the antifouling capability. The mixed matrix membranes were fabricated by mixing different amounts of nanofillers with dope solution followed by a phase inversion precipitation technique. The effect of the shape of the embedded nanofillers on the morphology and performance of the fabricated membranes was studied in terms of pure water flux, fouling resistance, hydrophilicity, surface, and bulk morphology by means of permeation tests, milk powder solution filtration, water contact angle and porosity measurements, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. Water flux of the mixed matrix membranes significantly improved after the addition of both types of ZnO nanofillers due to a higher hydrophilicity and porosity of the prepared membranes. The water contact angle measurements confirmed the increased hydrophilicity of the modified membranes, particularly in the ZnO nanorod mixed membranes. Fouling resistance of the membranes assessed by powder milk solution filtration revealed that 0.1 wt% ZnO nanorod membrane has the best antifouling property. The prepared mixed matrix membranes embedded with 0.1 wt% of both types of ZnO nanofillers showed a remarkable durability and reusability during the filtration tests; however, the best

  17. Preparation of mixed matrix PES-based nanofiltration membrane filled with PANI-co-MWCNT composite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bagheripour, Ehsan; Moghadassi, Abdolreza; Hosseini, Sayed Mohsen [Faculty of Engineering, Arak University, Arak (Iran, Islamic Republic of)

    2016-04-15

    Mixed matrix polyethersulfone/PANI-co-MWCNTs composite nanoparticle nanofiltration membrane was prepared by casting solution technique. Polyvinylpyrrolidone was also used as membrane pore former in membrane fabrication. The effect of polyaniline-co-multi walled carbon nanotubes composite nanoparticle concentration in the casting solution on membrane structure and performance was investigated. Scanning optical microscopy and scanning electron microscopy, FTIR analysis, porosity, mean pore size, contact angle, water content, NaCl/Na2SO4 rejection, water flux, tensile strength measurements and 3D surface image were also carried out in membrane characterization. SOM images showed nanoparticle agglomeration at high additive loading ratio. SEM images showed the membrane sub-layer porosity and thickness were changed by use of nanoparticles in membrane matrix. The membrane water content, porosity and pore size were increased by increase of nanoparticle concentration, except for 1%wt. Use of PANI-co- MWCNT nanoparticles in the membrane matrix caused a decrease of membrane contact angle from 63.43 to 46.76o. Salt rejection and water flux were improved initially by increase of nanoparticle concentration up to 0.1%wt and then decreased by more additive concentration. In addition, the membranes tensile strength was reduced by increase of PANI-co-MWCNTs composite nanoparticle concentration. 3D surface images showed a smoother surface for mixed matrix membrane filled with 0.1wt% PANI-co-MWCNTs. Modified membrane containing 0.1wt% composite nanoparticles showed better performance compared to others.

  18. Preparation of mixed matrix PES-based nanofiltration membrane filled with PANI-co-MWCNT composite nanoparticles

    International Nuclear Information System (INIS)

    Bagheripour, Ehsan; Moghadassi, Abdolreza; Hosseini, Sayed Mohsen

    2016-01-01

    Mixed matrix polyethersulfone/PANI-co-MWCNTs composite nanoparticle nanofiltration membrane was prepared by casting solution technique. Polyvinylpyrrolidone was also used as membrane pore former in membrane fabrication. The effect of polyaniline-co-multi walled carbon nanotubes composite nanoparticle concentration in the casting solution on membrane structure and performance was investigated. Scanning optical microscopy and scanning electron microscopy, FTIR analysis, porosity, mean pore size, contact angle, water content, NaCl/Na2SO4 rejection, water flux, tensile strength measurements and 3D surface image were also carried out in membrane characterization. SOM images showed nanoparticle agglomeration at high additive loading ratio. SEM images showed the membrane sub-layer porosity and thickness were changed by use of nanoparticles in membrane matrix. The membrane water content, porosity and pore size were increased by increase of nanoparticle concentration, except for 1%wt. Use of PANI-co- MWCNT nanoparticles in the membrane matrix caused a decrease of membrane contact angle from 63.43 to 46.76o. Salt rejection and water flux were improved initially by increase of nanoparticle concentration up to 0.1%wt and then decreased by more additive concentration. In addition, the membranes tensile strength was reduced by increase of PANI-co-MWCNTs composite nanoparticle concentration. 3D surface images showed a smoother surface for mixed matrix membrane filled with 0.1wt% PANI-co-MWCNTs. Modified membrane containing 0.1wt% composite nanoparticles showed better performance compared to others.

  19. Mixed matrix membranes prepared from high impact polystyrene with dispersed TiO2 nanoparticles for gas separation

    Directory of Open Access Journals (Sweden)

    P. Safaei

    2016-01-01

    Full Text Available The current study presents synthesis and characterization of high impact polystyrene - TiO2 nanoparticles mixed matrix membranes for separation of carbon dioxide from nitrogen. The solution-casting method was used for preparation of membranes. The nano mixed matrix membranes were characterized using scanning electron microscopy to ensure the suitable dispersion of nano particles in high impact polystyrene matrix. The effect of TiO2 nanoparticles loading on membrane performance was investigated. The separation performance of synthesized membranes was investigated in separation of CO2 from CO2/N2 mixture. Effect of feed pressure and TiO2 content on separation of CO2 was studied. The results revealed that increase of feed pressure decreases flux of gases through the mixed matrix membrane. The results also confirmed that the best separation performance can be obtained at TiO2 nanoparticles loading of 7 wt.%.

  20. Carbon dioxide selective mixed matrix composite membrane containing ZIF-7 nano-fillers

    KAUST Repository

    Li, Tao

    2013-01-01

    Mixed matrix materials made from selective inorganic fillers and polymers are very attractive for the manufacturing of gas separation membranes. But only few of these materials could be manufactured into high-performance asymmetric or composite membranes. We report here the first mixed matrix composite membrane made of commercially available poly (amide-b-ethylene oxide) (Pebax®1657, Arkema) mixed with the nano-sized zeolitic imidazole framework ZIF-7. This hybrid material has been successfully deposited as a thin layer (less than 1μm) on a porous polyacrylonitrile (PAN) support. An intermediate gutter layer of PTMSP was applied to serve as a flat and smooth surface for coating to avoid polymer penetration into the porous support. Key features of this work are the preparation and use of ultra-small ZIF-7 nano-particles (around 30-35nm) and the membrane processability of Pebax®1657. SEM pictures show that excellent adhesion and almost ideal morphology between the two phases has been obtained simply by mixing the as-synthesized ZIF-7 suspension into the Pebax®1657 dope, and no voids or clusters can be observed. The performance of the composite membrane is characterized by single gas permeation measurement of CO2, N2 and CH4. Both, permeability (PCO2 up to 145barrer) and gas selectivity (CO2/N2 up to 97 and CO2/CH4 up to 30) can be increased at low ZIF- loading. The CO2/CH4 selectivity can be further increased to 44 with the filler loading of 34wt%, but the permeability is reduced compared to the pure Pebax®1657 membrane. Polymer chain rigidification at high filler loading is supposed to be a reason for the reduced permeability. The composite membranes prepared in this work show better performance in terms of permeance and selectivity when compared with asymmetric mixed matrix membranes described in the recent literature. Overall, the ZIF 7/Pebax mixed matrix membranes show a high performance for CO2 separation from methane and other gas streams. They are easy to

  1. Ultem®/ZIF-8 mixed matrix hollow fiber membranes for CO2/N2 separations

    KAUST Repository

    Dai, Ying

    2012-05-01

    Organic-inorganic hybrid (mixed matrix) membranes can potentially extend the separation performance of traditional polymeric materials while maintaining processing convenience. Although many dense films studies have been reported, there have been few reported cases of these materials being successfully extended to asymmetric hollow fibers. In this work we report the first successful production of mixed matrix asymmetric hollow fiber membranes containing metal-organic-framework (MOF) ZIF-8 fillers. Specifically, we have incorporated ZIF-8 into a polyetherimide (Ultem ® 1000) matrix and produced dual-layer asymmetric hollow fiber membranes via the dry jet-wet quench method. The outer separating layer of these composite fibers contains 13wt% (17vol%) of ZIF-8 filler. These membranes have been tested over a range of temperatures and pressures for a variety of gas pairs. An increase in separation performance for the CO 2/N 2 gas pairs was observed for both pure gas and mixed gas feeds. © 2012 Elsevier B.V.

  2. Ultem®/ZIF-8 mixed matrix hollow fiber membranes for CO2/N2 separations

    KAUST Repository

    Dai, Ying; Johnson, J.R.; Karvan, Oğuz; Sholl, David S.; Koros, W.J.

    2012-01-01

    Organic-inorganic hybrid (mixed matrix) membranes can potentially extend the separation performance of traditional polymeric materials while maintaining processing convenience. Although many dense films studies have been reported, there have been few reported cases of these materials being successfully extended to asymmetric hollow fibers. In this work we report the first successful production of mixed matrix asymmetric hollow fiber membranes containing metal-organic-framework (MOF) ZIF-8 fillers. Specifically, we have incorporated ZIF-8 into a polyetherimide (Ultem ® 1000) matrix and produced dual-layer asymmetric hollow fiber membranes via the dry jet-wet quench method. The outer separating layer of these composite fibers contains 13wt% (17vol%) of ZIF-8 filler. These membranes have been tested over a range of temperatures and pressures for a variety of gas pairs. An increase in separation performance for the CO 2/N 2 gas pairs was observed for both pure gas and mixed gas feeds. © 2012 Elsevier B.V.

  3. Mixed matrix membranes with fast and selective transport pathways for efficient CO2 separation

    Science.gov (United States)

    Hou, Jinpeng; Li, Xueqin; Guo, Ruili; Zhang, Jianshu; Wang, Zhongming

    2018-03-01

    To improve CO2 separation performance, porous carbon nanosheets (PCNs) were used as a filler into a Pebax MH 1657 (Pebax) matrix, fabricating mixed matrix membranes (MMMs). The PCNs exhibited a preferential horizontal orientation within the Pebax matrix because of the extremely large 2D plane and nanoscale thickness of the matrix. Therefore, the micropores of the PCNs provided fast CO2 transport pathways, which led to increased CO2 permeability. The reduced pore size of the PCNs was a consequence of the overlapping of PCNs and the polymer chains penetrating into the pores of the PCNs. The reduction in the pore size of the PCNs improved the CO2/gas selectivity. As a result, the CO2 permeability and CO2/CH4 selectivity of the Pebax membrane with 10 wt% PCNs-loading (Pebax-PCNs-10) were 520 barrer and 51, respectively, for CO2/CH4 mixed-gas. The CO2 permeability and CO2/N2 selectivity of the Pebax-PCNs-10 membrane were 614 barrer and 61, respectively, for CO2/N2 mixed-gas.

  4. Perlecan and basement membrane-chondroitin sulfate proteoglycan (bamacan) are two basement membrane chondroitin/dermatan sulfate proteoglycans in the Engelbreth-Holm-Swarm tumor matrix

    DEFF Research Database (Denmark)

    Couchman, J R; Kapoor, R; Sthanam, M

    1996-01-01

    heparan sulfate proteoglycan, widespread in many basement membranes and connective tissues. We now identify two distinct proteoglycan species from this tumor source, which are substituted with galactosaminoglycans and which show basement membrane localization by immunohistochemistry. One species......The presence of proteoglycans bearing galactosaminoglycan chains has been reported, but none has been identified previously in the matrix of the Engelbreth-Holm-Swarm tumor, which is a source of several basement membrane components. This tumor matrix contains perlecan, a large, low buoyant density......-CSPG are distinct in core protein structure. Both are, however, basement membrane components, although there are tissue-specific differences in their distribution....

  5. Double layer mixed matrix membrane adsorbers improving capacity and safety hemodialysis

    Science.gov (United States)

    Saiful; Borneman, Z.; Wessling, M.

    2018-05-01

    Double layer mixed matrix membranes adsorbers have been developed for blood toxin removal by embedding activated carbon into cellulose acetate macroporous membranes. The membranes are prepared by phase inversion method via water vapor induced phase separation followed by an immersion precipitation step. Double layer MMM consisting of an active support and a separating layer. The active support layer consists of activated carbon particles embedded in macroporous cellulose acetate; the separating layer consists of particle free cellulose acetate. The double layer membrane possess an open and interconnected macroporous structure with a high loading of activated carbon available for blood toxins removal. The MMM AC has a swelling degree of 6.5 %, porosity of 53 % and clean water flux of 800 Lm-2h-1bar-1. The prepared membranes show a high dynamic Creatinine (Crt) removal during hemodilysis process. The Crt removal by adsorption contributes to amore than 83 % of the total removal. The double layer adsorptive membrane proves hemodialysis membrane can integrated with adsorption, in which blood toxins are removed in one step.

  6. Carbon capture from natural gas using multi-walled CNTs based mixed matrix membranes.

    Science.gov (United States)

    Hussain, Abid; Farrukh, Sarah; Hussain, Arshad; Ayoub, Muhammad

    2017-12-05

    Most of the polymers and their blends, utilized in carbon capture membranes, are costly, but cellulose acetate (CA) being inexpensive is a lucrative choice. In this research, pure and mixed matrix membranes (MMMs) have been fabricated to capture carbon from natural gas. Polyethylene glycol (PEG) has been utilized in the fabrication of membranes to modify the chain flexibility of polymers. Multi-walled carbon nanotubes (MWCNTs) provide mechanical strength, thermal stability, an extra free path for CO 2 molecules and augment CO 2 /CH 4 selectivity. Membranes of pure CA, CA/PEG blend of different PEG concentrations (5%, 10%, 15%) and CA/PEG/MWCNTs blend of 10% PEG with different MWCNTs concentrations (5%, 10%, 15%) were prepared in acetone using solution casting techniques. Fabricated membranes were characterized using SEM, TGA and tensile testing. Permeation results revealed remarkable improvement in CO 2 /CH 4 selectivity. In single gas experiments, CO 2 /CH 4 selectivity is enhanced 8 times for pure membranes containing 10% PEG and 14 times for MMMs containing 10% MWCNTs. In mix gas experiments, the CO 2 /CH 4 selectivity is increased 13 times for 10% PEG and 18 times for MMMs with 10% MWCNTs. Fabricated MMMs have a tensile strength of 13 MPa and are more thermally stable than CA membranes.

  7. CO2 Selective, Zeolitic Imidazolate Framework-7 Based Polymer Composite Mixed-Matrix Membranes

    KAUST Repository

    Chakrabarty, Tina; Neelakanda, Pradeep; Peinemann, Klaus-Viktor

    2018-01-01

    CO2 removal is necessary to mitigate the effects of global warming but it is a challenging process to separate CO2 from natural gas, biogas, and other gas streams. Development of hybrid membranes by use of polymers and metal-organic framework (MOF) particles is a viable option to overcome this challenge. A ZIF-7 nano-filler that was synthesized in our lab was embedded into a designed polymer matrix at various loadings and the performance of the mixed matrix membranes was evaluated in terms of gas permeance and selectivity. Hybrid membranes with various loadings (20, 30 and 40 wt%) were developed and tested at room temperature by a custom made time lag equipment and a jump in selectivity was observed when compared with the pristine polymer. A commercially attractive region for the selectivity CO2 over CH4 was achieved with a selectivity of 39 for 40 wt% particle loading. An increase in selectivity was observed with the increase of ZIF-7 loadings. Best performance was seen at 40% ZIF-7 loaded membrane with an ideal selectivity of 39 for CO2 over CH4. The obtained selectivity was 105% higher for CO2 over CH4 than the selectivity of the pristine polymer with a slight decrease in permeance. Morphological characterization of such developed membranes showed an excellent compatibility between the polymer and particle adhesion.

  8. CO2 Selective, Zeolitic Imidazolate Framework-7 Based Polymer Composite Mixed-Matrix Membranes

    KAUST Repository

    Chakrabarty, Tina

    2018-05-17

    CO2 removal is necessary to mitigate the effects of global warming but it is a challenging process to separate CO2 from natural gas, biogas, and other gas streams. Development of hybrid membranes by use of polymers and metal-organic framework (MOF) particles is a viable option to overcome this challenge. A ZIF-7 nano-filler that was synthesized in our lab was embedded into a designed polymer matrix at various loadings and the performance of the mixed matrix membranes was evaluated in terms of gas permeance and selectivity. Hybrid membranes with various loadings (20, 30 and 40 wt%) were developed and tested at room temperature by a custom made time lag equipment and a jump in selectivity was observed when compared with the pristine polymer. A commercially attractive region for the selectivity CO2 over CH4 was achieved with a selectivity of 39 for 40 wt% particle loading. An increase in selectivity was observed with the increase of ZIF-7 loadings. Best performance was seen at 40% ZIF-7 loaded membrane with an ideal selectivity of 39 for CO2 over CH4. The obtained selectivity was 105% higher for CO2 over CH4 than the selectivity of the pristine polymer with a slight decrease in permeance. Morphological characterization of such developed membranes showed an excellent compatibility between the polymer and particle adhesion.

  9. Prepare and characterization of nanocomposite - mixed matrix membranes based on polycarbonate

    International Nuclear Information System (INIS)

    Paranhos, Caio M.; Pessan, Luiz A.; Gomes, Ana C. de O.

    2009-01-01

    Mixed matrix membranes based on polycarbonate with different content of sepiolite were prepared by casting. The obtained membranes were characterized by wide-angle X-ray diffraction, thermal analysis, optical transparency and permeation to oxygen. The presence of sepiolite leads to the formation of a polymer-clay interface. The presence of the interface causes the increase in O 2 permeation. Increasing content of sepiolite results in aggregates of sepiolite, which forms preferential channels to the O 2 molecules. This fact is directly related to the strong increasing observed in O 2 permeability. (author)

  10. Synthesis and localization of two sulphated glycoproteins associated with basement membranes and the extracellular matrix

    DEFF Research Database (Denmark)

    Hogan, B L; Taylor, A; Kurkinen, M

    1982-01-01

    's membrane by mouse embryo parietal endoderm cells (Hogan, B. L.M., A. Taylor, and A.R. Cooper, 1982, Dev. Biol., 90:210-214). Both the Mr 180,000 and 150,000 sgps are deposited in the detergent-insoluble matrix of cultured cells, but they do not apparently undergo any disulphide-dependent intermolecular...... interactions and are not precursors or products of each other. They contain asparagine-linked oligosaccharides, but these are not the exclusive sites of sulphate labeling. Antiserum raised against the Mr 150,000 sgp C of Reichert's membranes has been used in an immunohistochemical analysis of rat skin...

  11. Interfacial Design of Mixed Matrix Membranes for Improved Gas Separation Performance.

    Science.gov (United States)

    Wang, Zhenggong; Wang, Dong; Zhang, Shenxiang; Hu, Liang; Jin, Jian

    2016-05-01

    High-performance metal-organic framework (MOF)/polyimide (PI) mixed matrix membranes (MMMs) are fabricated by a facile strategy by designing the MOF/PI matrix interface via poly dopamine coating. The overall separation performance of the designed MMMs surpasses the state-of-the-art 2008 Robeson upper bound for the H2 /CH4 and H2 /N2 gas pairs and approaches the 2008 upper bound for the O2 /N2 gas pair. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Web Based ATM PVC Management

    NARCIS (Netherlands)

    van der Waaij, B.D.; Sprenkels, Ron; van Beijnum, Bernhard J.F.; Pras, Aiko

    1998-01-01

    This paper discusses the design of a public domain web based ATM PVC Management tool for the Dutch SURFnet research ATM network. The aim of this tool is to assists in the creation and deletion of PVCs through local and remote ATM network domains. The tool includes security mechanisms to restrict the

  13. Plasma membrane factor XIIIA transglutaminase activity regulates osteoblast matrix secretion and deposition by affecting microtubule dynamics.

    Directory of Open Access Journals (Sweden)

    Hadil F Al-Jallad

    2011-01-01

    Full Text Available Transglutaminase activity, arising potentially from transglutaminase 2 (TG2 and Factor XIIIA (FXIIIA, has been linked to osteoblast differentiation where it is required for type I collagen and fibronectin matrix deposition. In this study we have used an irreversible TG-inhibitor to 'block -and-track' enzyme(s targeted during osteoblast differentiation. We show that the irreversible TG-inhibitor is highly potent in inhibiting osteoblast differentiation and mineralization and reduces secretion of both fibronectin and type I collagen and their release from the cell surface. Tracking of the dansyl probe by Western blotting and immunofluorescence microscopy demonstrated that the inhibitor targets plasma membrane-associated FXIIIA. TG2 appears not to contribute to crosslinking activity on the osteoblast surface. Inhibition of FXIIIA with NC9 resulted in defective secretory vesicle delivery to the plasma membrane which was attributable to a disorganized microtubule network and decreased microtubule association with the plasma membrane. NC9 inhibition of FXIIIA resulted in destabilization of microtubules as assessed by cellular Glu-tubulin levels. Furthermore, NC9 blocked modification of Glu-tubulin into 150 kDa high-molecular weight Glu-tubulin form which was specifically localized to the plasma membrane. FXIIIA enzyme and its crosslinking activity were colocalized with plasma membrane-associated tubulin, and thus, it appears that FXIIIA crosslinking activity is directed towards stabilizing the interaction of microtubules with the plasma membrane. Our work provides the first mechanistic cues as to how transglutaminase activity could affect protein secretion and matrix deposition in osteoblasts and suggests a novel function for plasma membrane FXIIIA in microtubule dynamics.

  14. Proteomics of Fuchs' Endothelial Corneal Dystrophy support that the extracellular matrix of Descemet's membrane is disordered

    DEFF Research Database (Denmark)

    Poulsen, Ebbe Toftgaard; Dyrlund, Thomas F; Runager, Kasper

    2014-01-01

    Fuchs' endothelial corneal dystrophy (FECD) is a major corneal disorder affecting the innermost part of the cornea, leading to visual impairment. As the morphological changes in FECD are mainly observed in the extracellular matrix of the Descemet's membrane/endothelial layer we determined...... that the morphological changes observed in FECD is caused in part by an aberrant assembly of the extracellular matrix within the Descemet's membrane/endothelial layer......., respectively, of which 10 were significantly regulated. The results indicated that the level of type VIII collagen was unaltered even though the protein previously has been implicated in familial early onset forms of the disease. Using the second relative quantitation method iTRAQ we identified 22...

  15. EXPERIMENTAL DESIGN AND RESPONSE SURFACE MODELING OF PI/PES-ZEOLITE 4A MIXED MATRIX MEMBRANE FOR CO2 SEPARATION

    Directory of Open Access Journals (Sweden)

    T. D. KUSWORO

    2015-09-01

    Full Text Available This paper investigates the effect of preparation of polyimide/polyethersulfone (PI/PES blending-zeolite mixed matrix membrane through the manipulation of membrane production variables such as polymer concentration, blending composition and zeolite loading. Combination of central composite design and response surface methodology were applied to determine the main effect and interaction effects of these variables on membrane separation performance. The quadratic models between each response and the independent parameters were developed and the response surface models were tested with analysis of variance (ANOVA. In this study, PI/ (PES–zeolite 4A mixed matrix membranes were casted using dry/wet phase inversion technique. The separation performance of mixed matrix membrane had been tested using pure gases such as CO2 and CH4. The results showed that zeolite loading was the most significant variable that influenced the CO2/CH4 selectivity among three variables and the experimental results were in good agreement with those predicted by the proposed regression models. The gas separation performance of the membrane was relatively higher as compare to polymeric membrane. Therefore, combination of central composite design and response surface methodology can be used to prepare optimal condition for mixed matrix membrane fabrication. The incorporation of 20 wt% zeolite 4A into 25 wt% of PI/PES matrix had resulted in a high separation performance of membrane material.

  16. [Application of the xenogenic acellular dermal matrix membrane application used in the postoperative tissue shortage repair].

    Science.gov (United States)

    Bai, Yanxia; Yan, Liying; Zhang, Shaoqiang; Shao, Yuan; Yao, Xiaobao; Li, Honghui; Zhao, Ruimin; Zhao, Qian; Zhang, Pengfei; Yang, Qi

    2014-09-01

    To observe the short-term and long-term curative effect of the xenogenic acellular dermal matrix membrane (or joint muscle flap transfer) application used in the 82 cases postoperative tissue shortage repair that after the head neck carcinoma resection. To held the 82 cases head neck carcinoma postoperative mucosa shortage repaired after resection by the xenogenic acellular dermal matrix membrane (or joint muscle flap transfer), 65 cases mucosa shortage wound be directly covered by the repair membrane and the other 17 cases mucosa shortage wound be repaired by the tranfered muscle tissue flap with the repair membrane covered; 53 cases underwent additional postoperative radiotherapy between 2-4 weeks and follow-up in 1, 3, 6, 12, 18, 24, 30, 36, 48, 60 months and observed the operation site repair process through the electronic laryngoscope, observed the patients respiration, swallow, phonation function. Seventy-seven cases patients operation incision reached I phase healing standard, another 5 cases patients operation incision reached II phase healing standard because of the wound infection and fully-recovered through the local wound drainage,dressing process. All the patients tracheal cannula,the stomach tube be extubated successfully and without the local cicatricial constriction occurred. Seventy-eight cases follow up period reached 1 year including 53 cases who underwent postoperative radiotherapy, 49 cases follow up period reached 3 years including 32 cases who underwent postoperative radiotherapy, 14 cases follow up period reached 5 years including 12 cases who underwent postoperative radiotherapy. The patients with static local lesions discovered no reaction such as exclusion, allergy. The application of xenogenic acellular dermal matrix membrane (or joint muscle flap transfer used in in the postoperative tissue shortage repair that after the head neck carcinoma resection have several advantage such as comparatively easily implementation, operation safety

  17. PES-Kaolin Mixed Matrix Membranes for Arsenic Removal from Water.

    Science.gov (United States)

    Marino, Tiziana; Russo, Francesca; Rezzouk, Lina; Bouzid, Abderrazak; Figoli, Alberto

    2017-09-30

    The aim of this work was the fabrication and the characterization of mixed matrix membranes (MMMs) for arsenic (As) removal from water. Membrane separation was combined with an adsorption process by incorporating the kaolin (KT2) Algerian natural clay in polymeric membranes. The effects of casting solution composition was explored using different amounts of polyethersufone (PES) as a polymer, polyvinyl-pyrrolidone (PVP K17) and polyethylene glycol (PEG 200) as pore former agents, N -methyl pyrrolidone (NMP) as a solvent, and kaolin. Membranes were prepared by coupling Non-solvent Induced Phase Separation and Vapour Induced Phase Separation (NIPS and VIPS, respectively). The influence of the exposure time to controlled humid air and temperature was also investigated. The MMMs obtained were characterized in terms of morphology, pore size, porosity, thickness, contact angle and pure water permeability. Adsorption membrane-based tests were carried out in order to assess the applicability of the membranes produced for As removal from contaminated water. Among the investigated kaolin concentrations (ranging from 0 wt % to 5 wt %), a content of 1.25 wt % led to the MMM with the most promising performance.

  18. Mixed Matrix Carbon Molecular Sieve and Alumina (CMS-Al2O3) Membranes.

    Science.gov (United States)

    Song, Yingjun; Wang, David K; Birkett, Greg; Martens, Wayde; Duke, Mikel C; Smart, Simon; Diniz da Costa, João C

    2016-07-29

    This work shows mixed matrix inorganic membranes prepared by the vacuum-assisted impregnation method, where phenolic resin precursors filled the pore of α-alumina substrates. Upon carbonisation, the phenolic resin decomposed into several fragments derived from the backbone of the resin matrix. The final stages of decomposition (>650 °C) led to a formation of carbon molecular sieve (CMS) structures, reaching the lowest average pore sizes of ~5 Å at carbonisation temperatures of 700 °C. The combination of vacuum-assisted impregnation and carbonisation led to the formation of mixed matrix of CMS and α-alumina particles (CMS-Al2O3) in a single membrane. These membranes were tested for pervaporative desalination and gave very high water fluxes of up to 25 kg m(-2) h(-1) for seawater (NaCl 3.5 wt%) at 75 °C. Salt rejection was also very high varying between 93-99% depending on temperature and feed salt concentration. Interestingly, the water fluxes remained almost constant and were not affected as feed salt concentration increased from 0.3, 1 and 3.5 wt%.

  19. Effects of ZnO Nanoparticle on the Gas Separation Performance of Polyurethane Mixed Matrix Membrane.

    Science.gov (United States)

    Soltani, Banafsheh; Asghari, Morteza

    2017-08-11

    Polyurethane (PU)-ZnO mixed matrix membranes (MMM) were fabricated and characterized for gas separation. A thermogravimetric analysis (TGA), a scanning electron microscope (SEM) test and an atomic-force microscopy (AFM) revealed that the physical properties and thermal stability of the membranes were improved through filler loading. Hydrogen Bonding Index, obtained from the Fourier transform infrared spectroscopy (FTIR), demonstrate that the degree of phase separation in PU-ZnO 0.5 wt % MMM was more than the neat PU, while in PU-ZnO 1.0 wt % MMM, the phase mixing had increased. Compared to the neat membrane, the CO₂ permeability of the MMMs increased by 31% for PU-ZnO 0.5 wt % MMM and decreased by 34% for 1.0 wt % ZnO MMM. The CO₂/CH₄ and CO₂/N₂ selectivities of PU-ZnO 0.5 wt % were 18.75 and 64.75, respectively.

  20. Balance between Apical Membrane Growth and Luminal Matrix Resistance Determines Epithelial Tubule Shape

    Directory of Open Access Journals (Sweden)

    Bo Dong

    2014-05-01

    Full Text Available The morphological stability of biological tubes is crucial for the efficient circulation of fluids and gases. Failure of this stability causes irregularly shaped tubes found in multiple pathological conditions. Here, we report that Drosophila mutants of the ESCRT III component Shrub/Vps32 exhibit a strikingly elongated sinusoidal tube phenotype. This is caused by excessive apical membrane synthesis accompanied by the ectopic accumulation and overactivation of Crumbs in swollen endosomes. Furthermore, we demonstrate that the apical extracellular matrix (aECM of the tracheal tube is a viscoelastic material coupled with the apical membrane. We present a simple mechanical model in which aECM elasticity, apical membrane growth, and their interaction are three vital parameters determining the stability of biological tubes. Our findings demonstrate a mechanical role for the extracellular matrix and suggest that the interaction of the apical membrane and an elastic aECM determines the final morphology of biological tubes independent of cell shape.

  1. Balance between apical membrane growth and luminal matrix resistance determines epithelial tubule shape.

    Science.gov (United States)

    Dong, Bo; Hannezo, Edouard; Hayashi, Shigeo

    2014-05-22

    The morphological stability of biological tubes is crucial for the efficient circulation of fluids and gases. Failure of this stability causes irregularly shaped tubes found in multiple pathological conditions. Here, we report that Drosophila mutants of the ESCRT III component Shrub/Vps32 exhibit a strikingly elongated sinusoidal tube phenotype. This is caused by excessive apical membrane synthesis accompanied by the ectopic accumulation and overactivation of Crumbs in swollen endosomes. Furthermore, we demonstrate that the apical extracellular matrix (aECM) of the tracheal tube is a viscoelastic material coupled with the apical membrane. We present a simple mechanical model in which aECM elasticity, apical membrane growth, and their interaction are three vital parameters determining the stability of biological tubes. Our findings demonstrate a mechanical role for the extracellular matrix and suggest that the interaction of the apical membrane and an elastic aECM determines the final morphology of biological tubes independent of cell shape. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Novel ZIF-300 Mixed-Matrix Membranes for Efficient CO2 Capture.

    Science.gov (United States)

    Yuan, Jianwei; Zhu, Haipeng; Sun, Jiajia; Mao, Yangyang; Liu, Gongping; Jin, Wanqin

    2017-11-08

    Because of the high separation performance and easy preparation, mixed-matrix membranes (MMMs) consisting of metal-organic frameworks have received much attention. In this article, we report a novel ZIF-300/PEBA MMM consisting of zeolite imidazolate framework (ZIF-300) crystals and polyether block amide (PEBA) matrix. The ZIF-300 crystal size was effectively reduced by optimizing the hydrothermal reaction condition from ∼15 to ∼1 μm. The morphology and physicochemical and sorption properties of the synthesized ZIF-300 crystals and as-prepared ZIF-300/PEBA MMMs were systematically studied. The results showed that ZIF-300 crystals with a size of ∼1 μm maintained excellent preferential CO 2 sorption over N 2 without degradation of the crystal structure in the MMMs. As a result, uniformly incorporated ZIF-300 crystals highly enhanced both the CO 2 permeability and the CO 2 /N 2 selectivity of pure PEBA membrane. The optimized ZIF-300-PEBA MMMs with a ZIF-300 loading of 30 wt % exhibited a high and stable CO 2 permeability of 83 Barrer and CO 2 /N 2 selectivity of 84, which are 59.2% and 53.5% higher than pure PEBA membrane, respectively. The obtained performance surpassed the upper bound of state-of-the-art membranes for CO 2 /N 2 separation. This work demonstrated that the proposed ZIF-300/PEBA MMM could be a potential candidate for an efficient CO 2 capture process.

  3. Functionalized carbon nanotubes mixed matrix membranes of polymers of intrinsic microporosity for gas separation.

    Science.gov (United States)

    Khan, Muntazim Munir; Filiz, Volkan; Bengtson, Gisela; Shishatskiy, Sergey; Rahman, Mushfequr; Abetz, Volker

    2012-09-06

    The present work reports on the gas transport behavior of mixed matrix membranes (MMM) which were prepared from multi-walled carbon nanotubes (MWCNTs) and dispersed within polymers of intrinsic microporosity (PIM-1) matrix. The MWCNTs were chemically functionalized with poly(ethylene glycol) (PEG) for a better dispersion in the polymer matrix. MMM-incorporating functionalized MWCNTs (f-MWCNTs) were fabricated by dip-coating method using microporous polyacrylonitrile membrane as a support and were characterized for gas separation performance. Gas permeation measurements show that MMM incorporated with pristine or functionalized MWCNTs exhibited improved gas separation performance compared to pure PIM-1. The f-MWCNTs MMM show better performance in terms of permeance and selectivity in comparison to pristine MWCNTs. The gas permeances of the derived MMM are increased to approximately 50% without sacrificing the selectivity at 2 wt.% of f-MWCNTs' loading. The PEG groups on the MWCNTs have strong interaction with CO2 which increases the solubility of polar gas and limit the solubility of nonpolar gas, which is advantageous for CO2/N2 selectivity. The addition of f-MWCNTs inside the polymer matrix also improved the long-term gas transport stability of MMM in comparison with PIM-1. The high permeance, selectivity, and long term stability of the fabricated MMM suggest that the reported approach can be utilized in practical gas separation technology.

  4. CO2/CH4 Separation by a Mixed Matrix Membrane of Polymethylpentyne/MIL-53 Particles

    Directory of Open Access Journals (Sweden)

    Reza Abedini

    2014-10-01

    Full Text Available The effect of Materials Institute Lavoisier-53 (MIL-53 particles on gas transport properties of polymethylpentyne (PMP was investigated. MIL-53 was added to the polymer matrix with different loadings of 10, 20 and 30 wt%. The properties of MIL-53 and prepared membranes were analyzed through FTIR, SEM and TGA methods. The adsorption of CO2 and CH4 was conducted and analyzed accurately through Langmuir equation to investigate the gas transport properties of membranes. The results from TGA showed that degradation temperature (Td increases significantly with increasing MIL-53 loading. SEM images demonstrated that MIL-53 particles dispersed well in polymer matrix with no considerable agglomeration and no non-selective void formation at polymer/filler interface. In addition, CO2 and CH4 permeability measurement along with calculation of CO2/CH4 selectivity were performed. The results showed that the permeability of gases (especially for CO2 increased significantly by increasing the MIL-53 loading. Additionally, CO2/CH4 selectivity showed an increasing trend with increasing the MIL-53 weight percent. Unlike CH4, the CO2 solubility coefficient increased with increasing the MIL-53 loading because of high free volume of membrane and selective adsorption of CO2 with MIL-53. Despite CO2 solubility enhancement its diffusivity coefficient remained more or less unchanged. The enhancement in CH4 permeability has been mainly attributed to its slight incremental diffusivity due to the membrane's increasingly higher free volume. Finally, a comparison between membranes performance and CO2/CH4 Robeson upper bound showed that, the performance of membranes improved due to the presence of MIL-53 which was very close to the Robeson bound.

  5. Calculating the permeability coefficients of mixed matrix membranes of polydimethylsiloxane and silicalite crystals to various ethanol-water solutions using molecular simulations.

    Science.gov (United States)

    The permeability coefficients of mixed matrix membranes of polydimethylsiloxane (PDMS) and silicalite crystal are taken as the sum of the permeability coefficients of membrane components each weighted by their associated mass fraction. The permeability coefficient of a membrane c...

  6. Electrospinning of PVC with natural rubber

    Science.gov (United States)

    Othman, Muhammad Hariz; Mohamed, Mahathir; Abdullah, Ibrahim

    2013-11-01

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber's mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

  7. Electrospinning of PVC with natural rubber

    International Nuclear Information System (INIS)

    Othman, Muhammad Hariz; Abdullah, Ibrahim; Mohamed, Mahathir

    2013-01-01

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber

  8. Electrospinning of PVC with natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Muhammad Hariz; Abdullah, Ibrahim [Department of Chemistry, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Mohamed, Mahathir [Radiation Processing Technology Division (BTS), Malaysian Nuclear Agency, Bangi, 43000, Kajang (Malaysia)

    2013-11-27

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

  9. Chalk effect on PVC cross-linking under irradiation; Vliyanie mela na sshivanie PVKh pri obluchenii

    Energy Technology Data Exchange (ETDEWEB)

    Chudinova, V V; Guzeev, V V; Mozzhukhin, V B; Pomerantseva, Eh G; Nozrina, F D; Zhil` tsov, V V; Zubov, V P

    1994-12-31

    Effect of nonmodified and modified chalk on curing degree of polymer matrix was studied under-irradiation of PVC-compositions. Films of the compositions (100 mass part 7 PVC, 0-100 mas.part of chalk, 2.5 - lead sulfate, 1.5 - lead stearate and 0.3 - glycerin) were irradiated up to absorbed dose 0.1 MGy in an inert medium. Content of gel-fraction after boiling in THF was determined with use of IR spectroscopy. It was established, that intensive dehydrochlorination and polymer curing took place on chalk particle surface. Network fixed strongly chalk particles. However, chalk inhibited processes of dehydrochlorination and PVC curing, increasing amount of noncured PVC in polymer matrix.

  10. RETGEM with polyvinylchloride (PVC) electrodes

    CERN Document Server

    Razin, V I; Reshetin, A I; Filippov, S N

    2009-01-01

    This paper presents a new design of the RETGEM (Resistive Electrode Thick GEM) based on electrodes made of a polyvinylchloride material (PVC). Our device can operate with gains of 10E5 as a conventional TGEM at low counting rates and as RPC in the case of high counting rates without of the transit to the violent sparks. The distinct feature of present RETGEM is the absent of the metal coating and lithographic technology for manufacturing of the protective dielectric rms. The electrodes from PVC permit to do the holes by a simple drilling machine. Detectors on a RETGEM basis could be useful in many fields of an application requiring a more cheap manufacturing and safe operation, for example, in a large neutrino experiments, in TPC, RICH systems.

  11. HIV-1 matrix dependent membrane targeting is regulated by Gag mRNA trafficking.

    Directory of Open Access Journals (Sweden)

    Jing Jin

    Full Text Available Retroviral Gag polyproteins are necessary and sufficient for virus budding. Productive HIV-1 Gag assembly takes place at the plasma membrane. However, little is known about the mechanisms by which thousands of Gag molecules are targeted to the plasma membrane. Using a bimolecular fluorescence complementation (BiFC assay, we recently reported that the cellular sites and efficiency of HIV-1 Gag assembly depend on the precise pathway of Gag mRNA export from the nucleus, known to be mediated by Rev. Here we describe an assembly deficiency in human cells for HIV Gag whose expression depends on hepatitis B virus (HBV post-transcriptional regulatory element (PRE mediated-mRNA nuclear export. PRE-dependent HIV Gag expressed well in human cells, but assembled with slower kinetics, accumulated intracellularly, and failed to associate with a lipid raft compartment where the wild-type Rev-dependent HIV-1 Gag efficiently assembles. Surprisingly, assembly and budding of PRE-dependent HIV Gag in human cells could be rescued in trans by co-expression of Rev-dependent Gag that provides correct membrane targeting signals, or in cis by replacing HIV matrix (MA with other membrane targeting domains. Taken together, our results demonstrate deficient membrane targeting of PRE-dependent HIV-1 Gag and suggest that HIV MA function is regulated by the trafficking pathway of the encoding mRNA.

  12. Crystal structure of an orthomyxovirus matrix protein reveals mechanisms for self-polymerization and membrane association.

    Science.gov (United States)

    Zhang, Wenting; Zheng, Wenjie; Toh, Yukimatsu; Betancourt-Solis, Miguel A; Tu, Jiagang; Fan, Yanlin; Vakharia, Vikram N; Liu, Jun; McNew, James A; Jin, Meilin; Tao, Yizhi J

    2017-08-08

    Many enveloped viruses encode a matrix protein. In the influenza A virus, the matrix protein M1 polymerizes into a rigid protein layer underneath the viral envelope to help enforce the shape and structural integrity of intact viruses. The influenza virus M1 is also known to mediate virus budding as well as the nuclear export of the viral nucleocapsids and their subsequent packaging into nascent viral particles. Despite extensive studies on the influenza A virus M1 (FLUA-M1), only crystal structures of its N-terminal domain are available. Here we report the crystal structure of the full-length M1 from another orthomyxovirus that infects fish, the infectious salmon anemia virus (ISAV). The structure of ISAV-M1 assumes the shape of an elbow, with its N domain closely resembling that of the FLUA-M1. The C domain, which is connected to the N domain through a flexible linker, is made of four α-helices packed as a tight bundle. In the crystal, ISAV-M1 monomers form infinite 2D arrays with a network of interactions involving both the N and C domains. Results from liposome flotation assays indicated that ISAV-M1 binds membrane via electrostatic interactions that are primarily mediated by a positively charged surface loop from the N domain. Cryoelectron tomography reconstruction of intact ISA virions identified a matrix protein layer adjacent to the inner leaflet of the viral membrane. The physical dimensions of the virion-associated matrix layer are consistent with the 2D ISAV-M1 crystal lattice, suggesting that the crystal lattice is a valid model for studying M1-M1, M1-membrane, and M1-RNP interactions in the virion.

  13. Preparation and characterization of polysulfone/zeolite mixed matrix membranes for removal of low-concentration ammonia from aquaculture wastewater.

    Science.gov (United States)

    Moradihamedani, Pourya; Abdullah, Abdul Halim

    2018-01-01

    Removal of low-concentration ammonia (1-10 ppm) from aquaculture wastewater was investigated via polysulfone (PSf)/zeolite mixed matrix membrane. PSf/zeolite mixed matrix membranes with different weight ratios (90/10, 80/20, 70/30 and 60/40 wt.%) were prepared and characterized. Results indicate that PSf/zeolite (80/20) was the most efficient membrane for removal of low-concentration ammonia. The ammonia elimination by PSf/zeolite (80/20) from aqueous solution for 10, 7, 5, 3 and 1 ppm of ammonia was 100%, 99%, 98.8%, 96% and 95% respectively. The recorded results revealed that pure water flux declined in higher loading of zeolite in the membrane matrix due to surface pore blockage caused by zeolite particles. On the other hand, ammonia elimination from water was decreased in higher contents of zeolite because of formation of cavities and macrovoids in the membrane substructure.

  14. Adsorptive removal of phenolic compounds using cellulose acetate phthalate–alumina nanoparticle mixed matrix membrane

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Raka; De, Sirshendu, E-mail: sde@che.iitkgp.ernet.in

    2014-01-30

    Highlights: • Composite membrane of cellulose–acetate–phthalate and alumina nanoparticle is cast. • Surface charge of the membrane changes with nanoparticle concentration and pH. • Separation of phenolic compounds occurs due to adsorption. • The removal efficiency is maximum for 20% nanoparticle with 91% removal of catechol. • Transmembrane pressure drop has negligible effect on solute separation. -- Abstract: Mixed matrix membranes (MMMs) were prepared using alumina nanoparticles and cellulose acetate phthalate (CAP) by varying concentration of nanoparticles in the range of 10 to 25 wt%. The membranes were characterized by scanning electron micrograph, porosity, permeability, molecular weight cut off, contact angle, surface zeta potential, mechanical strength. Addition of nanoparticles increased the porosity, permeability of the membrane up to 20 wt% of alumina. pH at point of zero charge of the membrane was 5.4. Zeta potential of the membrane became more negative up to 20 wt% of nanoparticles. Adsorption of phenolic derivatives, catechol, paranitrophenol, phenol, orthochloro phenol, metanitrophenol, by MMMs were investigated. Variation of rejection and permeate flux profiles were studied for different solutes as a function of various operating conditions, namely, solution pH, solute concentration in feed and transmembrane pressure drop. Difference in rejection of phenolic derivatives is consequence of interplay of surface charge and adsorption by alumina. Adsorption isotherm was fitted for different solutes and effects of pH were investigated. Catechol showed the maximum rejection 91% at solution pH 9. Addition of electrolyte reduced the rejection of solutes. Transmembrane pressure drop has insignificant effects on solute rejection. Competitive adsorption reduced the rejection of individual solute.

  15. Membrane-type matrix metalloproteases as diverse effectors of cancer progression.

    Science.gov (United States)

    Turunen, S Pauliina; Tatti-Bugaeva, Olga; Lehti, Kaisa

    2017-11-01

    Membrane-type matrix metalloproteases (MT-MMP) are pivotal regulators of cell invasion, growth and survival. Tethered to the cell membranes by a transmembrane domain or GPI-anchor, the six MT-MMPs can exert these functions via cell surface-associated extracellular matrix degradation or proteolytic protein processing, including shedding or release of signaling receptors, adhesion molecules, growth factors and other pericellular proteins. By interactions with signaling scaffold or cytoskeleton, the C-terminal cytoplasmic tail of the transmembrane MT-MMPs further extends their functionality to signaling or structural relay. MT-MMPs are differentially expressed in cancer. The most extensively studied MMP14/MT1-MMP is induced in various cancers along malignant transformation via pathways activated by mutations in tumor suppressors or proto-oncogenes and changes in tumor microenvironment including cellular heterogeneity, extracellular matrix composition, tissue oxygenation, and inflammation. Classically such induction involves transcriptional programs related to epithelial-to-mesenchymal transition. Besides inhibition by endogenous tissue inhibitors, MT-MMP activities are spatially and timely regulated at multiple levels by microtubular vesicular trafficking, dimerization/oligomerization, other interactions and localization in the actin-based invadosomes, in both tumor and the stroma. The functions of MT-MMPs are multifaceted within reciprocal cellular responses in the evolving tumor microenvironment, which poses the importance of these proteases beyond the central function as matrix scissors, and necessitates us to rethink MT-MMPs as dynamic signaling proteases of cancer. This article is part of a Special Issue entitled: Matrix Metalloproteinases edited by Rafael Fridman. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. [Evaluation of the Peusner's coefficients matrix for polymeric membrane and ternary non-electrolyte solutions].

    Science.gov (United States)

    Jasik-Slęzak, Jolanta; Slęzak-Prochazka, Izabella; Slęzak, Andrzej

    2014-01-01

    A system of network forms of Kedem-Katchalsky (K-K) equations for ternary non-electrolyte solutions is made of eight matrix equations containing Peusner's coefficients R(ij), L(ij), H(ij), W(ij), K(ij), N(ij), S(ij) or P(ij) (i, j ∈ {1, 2, 3}). The equations are the result of symmetric or hybrid transformation of the classic form of K-K equations by the use of methods of Peusner's network thermodynamics (PNT). Calculating concentration dependences of the determinant of Peusner's coefficients matrixes R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) and P(ij) (i, j ∈ {1, 2, 3}). The material used in the experiment was a hemodialysis Nephrophan membrane with specified transport properties (L(p), σ, Ω) in aqueous glucose and ethanol solution. The method involved equations for determinants of the matrixes coefficients R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) or P(ij) (i, j ∈ {1, 2, 3}). The objective of calculations were dependences of determinants of Peusner's coeffcients matrixes R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) or P(ij) (i, j ∈ {1, 2, 3}) within the conditions of solution homogeneity upon an average concentration of one component of solution in the membrane (C1) with a determined value of the second component (C2). The method of calculating the determinants of Peusner's coeffcients matrixes R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) or P(ij) (i, j ∈ {1, 2, 3}) is a new tool that may be applicable in studies on membrane transport. Calculations showed that the coefficients are sensitive to concentration and composition of solutions separated by a polymeric membrane.

  17. Fabrication of Functionalized MOFs Incorporated Mixed Matrix Hollow Fiber Membrane for Gas Separation

    Directory of Open Access Journals (Sweden)

    Haitao Zhu

    2017-01-01

    Full Text Available The metal-organic framework (MOFs of MIL-53 was functionalized by aminosilane grafting and then incorporated into Ultem®1000 polymer matrix to fabricate mixed matrix hollow fiber membrane (MMHFM with high separation performance. SEM, XRD, and TGA were performed to characterize the functionalized MIL-53 and prepared MMHFM. The filler particles were embedded in membrane successfully and dispersed well in the polymer matrix. The incorporation of MOFs endowed MMHFM better thermal stability. Moreover, effects of solvent ratio in spinning dope, spinning condition, and testing temperature on gas separation performance of MMHFM were investigated. By optimizing dope composition, air gap distance, and bore fluid composition, MMHFM containing functionalized MIL-53 achieved excellent gas permeance and CO2/N2 selectivity. The CO2 permeance increased from 12.2 GPU for pure Ultem HFM to 30.9 GPU and the ideal CO2/N2 selectivity was enhanced from 25.4 to 34.7 simultaneously. Additionally, gas permeance increased but the selectivity decreased with the temperature increase, which followed the solution-diffusion based transport mechanism.

  18. Gas transport in metal organic framework–polyetherimide mixed matrix membranes: The role of the polyetherimide backbone structure

    NARCIS (Netherlands)

    Hegde, Maruti; Shahid, S.; Norder, Ben; Dingemans, Theo J.; Nijmeijer, Dorothea C.

    2015-01-01

    We report on how the morphology of the polymer matrix, i.e. amorphous vs. semi-crystalline, affects the gas transport properties in a series of mixed matrix membranes (MMMs) using Cu3(BTC)2 as the metal organic framework (MOF) filler. The aim of our work is to demonstrate how incorporation of

  19. Gas transport in metal organic framework-polyetherimide mixed matrix membranes: The role of the polyetherimide backbone structure

    NARCIS (Netherlands)

    Hegde, Maruti; Shahid, Salman; Norder, Ben; Dingemans, T.J.; Nijmeijer, Kitty

    2015-01-01

    We report on how the morphology of the polymer matrix, i.e. amorphous vs. semi-crystalline, affects the gas transport properties in a series of mixed matrix membranes (MMMs) using Cu3(BTC)2 as the metal organic framework (MOF) filler. The aim of our work is to demonstrate how incorporation of

  20. Annexin A2 Mediates the Localization of Measles Virus Matrix Protein at the Plasma Membrane.

    Science.gov (United States)

    Koga, Ritsuko; Kubota, Marie; Hashiguchi, Takao; Yanagi, Yusuke; Ohno, Shinji

    2018-02-28

    Annexins are a family of structurally related proteins that bind negatively charged membrane phospholipids in a Ca 2+ -dependent manner. Annexin A2 (AnxA2), a member of the family, has been implicated in a variety of cellular functions including the organization of membrane domains, vesicular trafficking and cell-cell adhesion. AnxA2 generally forms the heterotetrameric complex with a small Ca 2+ -binding protein S100A10. Measles virus (MV), a member of the family Paramyxoviridae , is an enveloped virus with a nonsegmented negative strand RNA genome. Knockdown of AnxA2 greatly reduced MV growth in cells, without affecting its entry and viral RNA production. In MV-infected, AnxA2-knockdown cells, the expression level of the matrix (M) protein, but not other viral proteins, was reduced compared with that in control cells, and the distribution of the M protein at the plasma membrane was decreased. The M protein lines the inner surface of the envelope and plays an important role in virus assembly by connecting the nucleocapsid to the envelope proteins. The M protein bound to AnxA2 independently of AnxA2's phosphorylation or its association with S100A10, and was co-localized with AnxA2 within cells. Truncation of the N-terminal 10 amino acid residues, but not the N-terminal 5 residues, compromised the ability of the M protein to interact with AnxA2 and localize at the plasma membrane. These results indicate that AnxA2 mediates the localization of the MV M protein at the plasma membrane by interacting with its N-terminal region (especially residues at positions 6-10), thereby aiding in MV assembly. IMPORTANCE Measles virus (MV) is an important human pathogen, still claiming ∼ 100,000 lives per year despite the presence of effective vaccines, and causes occasional outbreaks even in developed countries. Replication of viruses largely relies on the functions of host cells. Our study revealed that the reduction of the host protein annexin A2 compromises the replication of

  1. Preparation of Ethylene Vinyl Acetate/Zeolite 4A Mixed Matrix Membrane for CO2/N2 Separation

    Directory of Open Access Journals (Sweden)

    Iman Khalilinejad

    2016-07-01

    Full Text Available A great contribution in research activities on carbon dioxide (CO2 separation, as the most important challenge in greenhouse gases control, has been made to develop new polymeric membranes. In this case, mixed matrix membranes (MMMs, comprised of rigid particles dispersed in a continuous polymeric matrix, was proposed as an effective method to improve the separation properties of polymeric membranes. In this research, ethylene vinyl acetate (EVA copolymer and zeolite 4A powders were applied to prepare MMMs using solution casting/solvent evaporation method and CO2/N2 separation performance of the membranes was examined under different feed pressures (3-8 bar and operating temperatures (25-50°C. Morphological and structural characterizations of the membranes were evaluated using scanning electron microscopy (SEM, Fourier transform infrared (FTIR spectroscopy, differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, density and solvent-induced swelling measurements. The gas permeability measurements through the constant-volume method showed the permeability of two gases increased in the presence of zeolite 4A nanoparticles in the polymer matrix. Calculation of diffusivity coefficients of gases revealed that improvement in the diffusivity of all gases into membrane matrix was the main reason for permeability enhancement. In addition, the increase in the CO2/N2 ideal selectivity with the presence of zeolite 4A nanoparticles in the polymer matrix was attributed to the increment in CO2/N2 diffusion selectivity. Under optimum condition, with the addition of 10 wt% zeolite 4A nanoparticles into the membrane matrix, the CO2 permeability increased from 20.81 to 35.24 Barrer and its related selectivity increased 20% compared to that of neat EVA membrane. Furthermore, the membrane performances increased upon feed pressure rise, while the selectivity decreased with the increase in temperature.

  2. Effect of Extracellular Matrix Membrane on Bone Formation in a Rabbit Tibial Defect Model

    Directory of Open Access Journals (Sweden)

    Jin Wook Hwang

    2016-01-01

    Full Text Available Absorbable extracellular matrix (ECM membrane has recently been used as a barrier membrane (BM in guided tissue regeneration (GTR and guided bone regeneration (GBR. Absorbable BMs are mostly based on collagen, which is more biocompatible than synthetic materials. However, implanted absorbable BMs can be rapidly degraded by enzymes in vivo. In a previous study, to delay degradation time, collagen fibers were treated with cross-linking agents. These compounds prevented the enzymatic degradation of BMs. However, cross-linked BMs can exhibit delayed tissue integration. In addition, the remaining cross-linker could induce inflammation. Here, we attempted to overcome these problems using a natural ECM membrane. The membrane consisted of freshly harvested porcine pericardium that was stripped from cells and immunoreagents by a cleaning process. Acellular porcine pericardium (APP showed a bilayer structure with a smooth upper surface and a significantly coarser bottom layer. APP is an ECM with a thin layer (0.18–0.35 mm but with excellent mechanical properties. Tensile strength of APP was 14.15±2.24 MPa. In in vivo experiments, APP was transplanted into rabbit tibia. The biocompatible material was retained for up to 3 months without the need for cross-linking. Therefore, we conclude that APP could support osteogenesis as a BM for up to 3 months.

  3. Copolyimide mixed matrix membranes with oriented microporous titanosilicate JDF-L1sheet particles

    OpenAIRE

    Galve, Alejandro; Vispe, Eugenio; Téllez, Carlos; Coronas, Joaquín

    2011-01-01

    JDF-L1 is a microporous titanosilicate exhibiting a layer structure with pore size of about 3 Å. It is consequently an attractive material to separate H2-containing mixtures. This is the reason why JDF-L1, after disaggregation by means of hexadecyltrimethylammonium surfactant, has been combined with a carboxyl group containing copolyimide (6FDA-4MPD/6FDA-DABA 4:1) to produce mixed matrix membranes, which were applied to the separation of H2/CH4 and O2/N2 mixtures. Additionally, due to the she...

  4. Membrane association and localization dynamics of the Ebola virus matrix protein VP40.

    Science.gov (United States)

    Gc, Jeevan B; Gerstman, Bernard S; Chapagain, Prem P

    2017-10-01

    The Ebola virus matrix protein VP40 is a major structural protein that provides the scaffolding for new Ebola virus particles. For this, VP40 is first trafficked to the lower leaflet of the plasma membrane (PM) in its dimeric form. Once associated with the PM, the VP40 dimers undergo structural rearrangements and oligomerize into hexamers and filaments that make up the virus matrix. Therefore, association of the VP40 dimers and their stabilization at the PM is a crucial step in the Ebola life-cycle. To understand the molecular details of the VP40 dimer-PM interactions, we investigated the dimer association with the inner leaflet of the PM using detailed all-atom molecular dynamics (MD) simulations. The formation of the dimer-PM complex is facilitated by the interactions of the VP40 lysine residues and the anionic lipids POPS, POPI, and PIP 2 in the PM. In contrast, the dimer fails to associate with a membrane without POPS, POPI, or PIP 2 lipids. We explored the mechanisms of the association and identified important residues and lipids involved in localization and stabilization of VP40 dimers at the PM. MD simulations elucidate the role of a C-terminal α-helix alignment parallel to the lipid bilayer surface as well as the creation of membrane defects that allow partial insertion of the hydrophobic residue V276 into the membrane to further stabilize the VP40 dimer-PM complex. Understanding the mechanisms of the VP40 dimer-PM association that facilitate oligomerization can be important for potentially targeting the VP40 for small molecules that can interfere with the virus life-cycle. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Phosphatidylserine Lateral Organization Influences the Interaction of Influenza Virus Matrix Protein 1 with Lipid Membranes.

    Science.gov (United States)

    Bobone, Sara; Hilsch, Malte; Storm, Julian; Dunsing, Valentin; Herrmann, Andreas; Chiantia, Salvatore

    2017-06-15

    Influenza A virus matrix protein 1 (M1) is an essential component involved in the structural stability of the virus and in the budding of new virions from infected cells. A deeper understanding of the molecular basis of virion formation and the budding process is required in order to devise new therapeutic approaches. We performed a detailed investigation of the interaction between M1 and phosphatidylserine (PS) (i.e., its main binding target at the plasma membrane [PM]), as well as the distribution of PS itself, both in model membranes and in living cells. To this end, we used a combination of techniques, including Förster resonance energy transfer (FRET), confocal microscopy imaging, raster image correlation spectroscopy, and number and brightness (N&B) analysis. Our results show that PS can cluster in segregated regions in the plane of the lipid bilayer, both in model bilayers constituted of PS and phosphatidylcholine and in living cells. The viral protein M1 interacts specifically with PS-enriched domains, and such interaction in turn affects its oligomerization process. Furthermore, M1 can stabilize PS domains, as observed in model membranes. For living cells, the presence of PS clusters is suggested by N&B experiments monitoring the clustering of the PS sensor lactadherin. Also, colocalization between M1 and a fluorescent PS probe suggest that, in infected cells, the matrix protein can specifically bind to the regions of PM in which PS is clustered. Taken together, our observations provide novel evidence regarding the role of PS-rich domains in tuning M1-lipid and M1-M1 interactions at the PM of infected cells. IMPORTANCE Influenza virus particles assemble at the plasma membranes (PM) of infected cells. This process is orchestrated by the matrix protein M1, which interacts with membrane lipids while binding to the other proteins and genetic material of the virus. Despite its importance, the initial step in virus assembly (i.e., M1-lipid interaction) is still

  6. Engineering of Mixed Matrix Membranes for Water Treatment, Protective Coating and Gas Separation

    KAUST Repository

    Hammami, Mohamed Amen

    2017-11-01

    Mixed Matrix Membranes (MMMs) have received worldwide attention during the last decades. This is due to the fact that the resulting materials can combine the good processability and low cost of polymer membranes with the diverse functionality, high performance and thermal properties of the fillers. This work explores the fabrication and application of MMMs. We focused on the design and fabrication of nanofillers to impart target functionality to the membrane for water treatment, protective coating and gas separation. This thesis is divided into three sections according to the application including: I- Water Treatment: This part is divided into three chapters, two related to the membrane distillation (MD) and one related to the oil spill. Three different nanofillers have been used: Periodic mesoporous organosilica (PMO), graphene and carbon nanotube (CNT). Those nanofillers were homogeneously incorporated into polyetherimide (PEI) electrospun nanofiber membranes. The doped nanoparticle not only improved the mechanical properties and thermal stability of the pristine fiber but also enhanced the MD and oil spill performance due to the functionality of those nanofillers. II- Protective coating: This part includes two chapters describing the design and the fabrication of a smart antibacterial and anti-corrosion coating. In the first project, we fabricated colloidal lysozyme-templated gold nanoclusters gating antimicrobial-loaded silica nanoparticles (MSN-AuNCs@lys) as nano-fillers in poly(ethylene oxide)/poly(butylene terephthalate) polymer matrix. MSN-AuNCs@lys dispersed homogeneously within the polymer matrix with zero NPs leaching. The system was coated on a common radiographic dental imaging device that is prone to oral bacteria contamination. This coating can successfully sense and inhibit bacterial contamination via a controlled release mechanism that is only triggered by bacteria. In the second project, the coaxial electrospinning approach has been applied to

  7. Radiation crosslinking of PVC with polyfunctional monomers

    International Nuclear Information System (INIS)

    Dobo, J.; Takacs, E.; Csato, P.

    1984-01-01

    The radiation crosslinking of PVC in the presence of ethylene glycol dimethacrylate (EGDM) and of trimethylol propane trimethacrylate (TMPTM) was investigated. The effect of PVC powders of different types on the polymerization rate of these monomers was studied by a Calvet-type microcalorimeter. In the milled PVC sheets containing 50 part EGDM a high concentration of trapped free radicals was found by ESR after 16 months storage. (author)

  8. THE EFFECT OF TYPE ZEOLITE ON THE GAS TRANSPORT PROPERTIES OF POLYIMIDE-BASED MIXED MATRIX MEMBRANES

    Directory of Open Access Journals (Sweden)

    Tutuk Djoko Kusworo

    2012-01-01

    Full Text Available The permeation rates of O2, N2, CO2 and CH4 has been studied for polyimide-polyethersulfone (PI/PES blends-zeolite mixed matrix membranes synthesized in our laboratory. The study investigated the effect of zeolite loading and different zeolite type on the gas separation performance of these mixed matrix membranes. Frequency shifts and absorption intensity changes in the FTIR spectra of the PI/PES blends as compared with those of the pure polymers indicate that there is a mixing of polymer blends at the molecular level. Differential scanning calorimetry measurements of pure and PI/PES blends membranes have showed one unique glass transition temperature that supports the miscible character of the PI/PES mixture. The PI/PES-zeolite 4A mixed matrix membrane with 25 wt % zeolite loading produced the highest O2/N2 and CO2/CH4 selectivity of around 7.45 and 46.05, respectively.

  9. PVC pipes in gas distribution: still going strong!

    NARCIS (Netherlands)

    Hermkens, Rene; Wolters, Mannes; Weller, Jeroen; Visser, Roy; Davidovski, Z.; Belloir, P.; Fumire, J.

    2008-01-01

    In the Netherlands (impact-modified) PVC is the preferred material for low-pressure (30 and 100 mbar) gas distribution systems. More than 50% of the total length (about 122,000 km) of this system is rigid PVC or impact-modified PVC. The installation of rigid PVC (uPVC) pipelines started about 50

  10. DIDS prevents ischemic membrane degradation in cultured hippocampal neurons by inhibiting matrix metalloproteinase release.

    Directory of Open Access Journals (Sweden)

    Matthew E Pamenter

    Full Text Available During stroke, cells in the infarct core exhibit rapid failure of their permeability barriers, which releases ions and inflammatory molecules that are deleterious to nearby tissue (the penumbra. Plasma membrane degradation is key to penumbral spread and is mediated by matrix metalloproteinases (MMPs, which are released via vesicular exocytosis into the extracellular fluid in response to stress. DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid preserves membrane integrity in neurons challenged with an in vitro ischemic penumbral mimic (ischemic solution: IS and we asked whether this action was mediated via inhibition of MMP activity. In cultured murine hippocampal neurons challenged with IS, intracellular proMMP-2 and -9 expression increased 4-10 fold and extracellular latent and active MMP isoform expression increased 2-22 fold. MMP-mediated extracellular gelatinolytic activity increased ∼20-50 fold, causing detachment of 32.1±4.5% of cells from the matrix and extensive plasma membrane degradation (>60% of cells took up vital dyes and >60% of plasma membranes were fragmented or blebbed. DIDS abolished cellular detachment and membrane degradation in neurons and the pathology-induced extracellular expression of latent and active MMPs. DIDS similarly inhibited extracellular MMP expression and cellular detachment induced by the pro-apoptotic agent staurosporine or the general proteinase agonist 4-aminophenylmercuric acetate (APMA. Conversely, DIDS-treatment did not impair stress-induced intracellular proMMP production, nor the intracellular cleavage of proMMP-2 to the active form, suggesting DIDS interferes with the vesicular extrusion of MMPs rather than directly inhibiting proteinase expression or activation. In support of this hypothesis, an antagonist of the V-type vesicular ATPase also inhibited extracellular MMP expression to a similar degree as DIDS. In addition, in a proteinase-independent model of vesicular exocytosis, DIDS

  11. Sulfur removal from fuel using zeolites/polyimide mixed matrix membrane adsorbents

    International Nuclear Information System (INIS)

    Lin, Ligang; Wang, Andong; Dong, Meimei; Zhang, Yuzhong; He, Benqiao; Li, Hong

    2012-01-01

    Graphical abstract: Membrane adsorption process is proposed for sulfur removal. Three-dimensional network structure is key to fulfill adsorption function of MMMs, which adsorption/desorption behavior is markedly related with binding force with sulfur molecules. Highlights: ► Membrane adsorption process is proposed for sulfur removal. ► Three-dimensional network structure of MMMs is key to fulfill adsorption function. ► Adsorption/desorption behavior is markedly related with binding force. - Abstract: A novel membrane adsorption process was proposed for the sulfur removal from fuels. The mixed matrix membranes (MMMs) adsorbents composed of polyimide (PI) and various Y zeolites were prepared. By the detailed characterization of FT-IR, morphology, thermal and mechanical properties of MMMs adsorbents, combining the adsorption and desorption behavior research, the process–structure–function relationship was discussed. Field-emission scanning electron microscope (FESEM) images show that the functional particles are incorporated into the three-dimensional network structure. MMMs adsorbents with 40% of zeolites content possess better physical properties, which was confirmed by mechanical strength and thermo stability analysis. Influence factors including post-treatment, content of incorporated zeolites, adsorption time, temperature, initial sulfur concentration as well as sulfur species on the adsorption performance of MMMs adsorbents have been evaluated. At 4 wt.% zeolites content, adsorption capacity for NaY/PI, AgY/PI and CeY/PI MMMs adsorbents come to 2.0, 7.5 and 7.9 mg S/g, respectively. And the regeneration results suggest that the corresponding spent membranes can recover about 98%, 90% and 70% of the desulfurization capacity, respectively. The distinct adsorption and desorption behavior of MMMs adsorbents with various functional zeolites was markedly related with their various binding force and binding mode with sulfur compounds.

  12. Development and characterization of polyethersulfone/TiO2 mixed matrix membranes for CO2/CH4 separation

    Science.gov (United States)

    Galaleldin, S.; Mannan, H. A.; Mukhtar, H.

    2017-12-01

    In this study, mixed matrix membranes comprised of polyethersulfone as the bulk polymer phase and titanium dioxide (TiO2) nanoparticles as the inorganic discontinuous phase were prepared for CO2/CH4 separation. Membranes were synthesized at filler loading of 0, 5, 10 and 15 wt % via dry phase inversion method. Morphology, chemical bonding and thermal characteristics of membranes were scrutinized utilizing different techniques, namely: Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform InfraRed (FTIR) spectra and Thermogravimetric analysis (TGA) respectively. Membranes gas separation performance was evaluated for CO2 and CH4 gases at 4 bar feed pressure. The highest separation performance was achieved by mixed matrix membrane (MMM) at 5 % loading of TiO2.

  13. Effect of oil extracted from coffee grounds in the radiolytic stabilization of PVC

    International Nuclear Information System (INIS)

    Lima, Thaysa Araujo de; Aquino, Katia Aparecida da Silva; Araujo, Elmo S.

    2013-01-01

    Commercial Poly(vinyl chloride) (PVC) containing oil extracted from coffee grounds (OCG) at concentrations of 0.50; 1.00 and 1.50 wt% were investigated. The samples were irradiated with gamma radiation ( 60 Co) at room temperature and air atmosphere. The viscosity-average molar mass (M v ) was measured for PVC systems without and with oil. Decreases in molar mass observed when the systems were gamma irradiated reflect the random scission effects that take place in the main chain. Degradation index (DI) value was also obtained by viscosity analysis. DI results showed that the addition of OCG at 0.5 wt% into PVC matrix irradiated at dose of 25 kGy decreased the number of main chain scissions and was calculated a protection index of 67% in PVC matrix. Results about the free radical scavenger action of the OCG were obtained by use of 2,2-diphenyl-1-(2,4,6-trinitrophenyl)-hydrazyl radical (DPPH) and are discussed in this study. Decrease of 7% of Young's modulus value and a decrease of 31.5% on the elongation at break value were recorded for PVC films exposed to gamma irradiation. However, no significant changes were recorded in mechanical properties of PVC with OCG. (author)

  14. Effect of oil extracted from coffee grounds in the radiolytic stabilization of PVC

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Thaysa Araujo de; Aquino, Katia Aparecida da Silva; Araujo, Elmo S., E-mail: aquino@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2013-07-01

    Commercial Poly(vinyl chloride) (PVC) containing oil extracted from coffee grounds (OCG) at concentrations of 0.50; 1.00 and 1.50 wt% were investigated. The samples were irradiated with gamma radiation ({sup 60}Co) at room temperature and air atmosphere. The viscosity-average molar mass (M{sub v}) was measured for PVC systems without and with oil. Decreases in molar mass observed when the systems were gamma irradiated reflect the random scission effects that take place in the main chain. Degradation index (DI) value was also obtained by viscosity analysis. DI results showed that the addition of OCG at 0.5 wt% into PVC matrix irradiated at dose of 25 kGy decreased the number of main chain scissions and was calculated a protection index of 67% in PVC matrix. Results about the free radical scavenger action of the OCG were obtained by use of 2,2-diphenyl-1-(2,4,6-trinitrophenyl)-hydrazyl radical (DPPH) and are discussed in this study. Decrease of 7% of Young's modulus value and a decrease of 31.5% on the elongation at break value were recorded for PVC films exposed to gamma irradiation. However, no significant changes were recorded in mechanical properties of PVC with OCG. (author)

  15. Mixed-matrix membranes containing an azine-linked covalent organic framework: Influence of the polymeric matrix on post-combustion CO 2 -capture

    NARCIS (Netherlands)

    Shan, Meixia; Seoane de la Cuesta, Beatriz; Andres-Garcia, Eduardo; Kapteijn, Freek; Gascon, Jorge

    2018-01-01

    The use of an azine-linked covalent organic framework (ACOF-1) as filler in mixed-matrix membranes (MMMs) has been studied for the separation of CO2 from N2. To better understand the mechanisms that govern separation in complex composites, MMMs were prepared with different loadings of ACOF-1 and

  16. Migration of additives from poly(vinyl chloride) (PVC) tubes into aqueous media

    DEFF Research Database (Denmark)

    Wang, Qian; Storm, Birgit Kjærside

    2005-01-01

    The stability and migration product of medical PVC tubes plasticized with polyadipates were investigated by ageing in phosphate buffer at pH 1.679 and water at different temperatures. Changes in the PVC tubes were studied by wtaer absorption, weight loss, Fourier infrared spectroscopy (FTIR.......5% and only a small amount of adipic acid migrated when a tube was aged at 37 C in water and phosphate buffer (pH 1.679), and at 70 C in water after 56 days. However, when aged at 70 and 110 C, gradual deactivation of heat stabilizer after 21 days of ageing in buffer solution and separation of plasticizer...... from PVC matrix occurred. When the tube was aged at 110 C, significant degradation of both polyadipates and PVC were observed. Adipic acid and 1,4-butanediol monomers and oligomers of polyadipate were the major migration products from polyadipates in the water ageing solution, while only a relatively...

  17. Dimerization Efficiency of Canine Distemper Virus Matrix Protein Regulates Membrane-Budding Activity.

    Science.gov (United States)

    Bringolf, Fanny; Herren, Michael; Wyss, Marianne; Vidondo, Beatriz; Langedijk, Johannes P; Zurbriggen, Andreas; Plattet, Philippe

    2017-08-15

    Paramyxoviruses rely on the matrix (M) protein to orchestrate viral assembly and budding at the plasma membrane. Although the mechanistic details remain largely unknown, structural data suggested that M dimers and/or higher-order oligomers may facilitate membrane budding. To gain functional insights, we employed a structure-guided mutagenesis approach to investigate the role of canine distemper virus (CDV) M protein self-assembly in membrane-budding activity. Three six-alanine-block (6A-block) mutants with mutations located at strategic oligomeric positions were initially designed. While the first one includes residues potentially residing at the protomer-protomer interface, the other two display amino acids located within two distal surface-exposed α-helices proposed to be involved in dimer-dimer contacts. We further focused on the core of the dimeric interface by mutating asparagine 138 (N138) to several nonconservative amino acids. Cellular localization combined with dimerization and coimmunopurification assays, performed under various denaturing conditions, revealed that all 6A-block mutants were impaired in self-assembly and cell periphery accumulation. These phenotypes correlated with deficiencies in relocating CDV nucleocapsid proteins to the cell periphery and in virus-like particle (VLP) production. Conversely, all M-N138 mutants remained capable of self-assembly, though to various extents, which correlated with proper accumulation and redistribution of nucleocapsid proteins at the plasma membrane. However, membrane deformation and VLP assays indicated that the M-N138 variants exhibiting the most reduced dimerization propensity were also defective in triggering membrane remodeling and budding, despite proper plasma membrane accumulation. Overall, our data provide mechanistic evidence that the efficiency of CDV M dimerization/oligomerization governs both cell periphery localization and membrane-budding activity. IMPORTANCE Despite the availability of

  18. Metal-organic frameworks in mixed-matrix membranes for gas separation.

    Science.gov (United States)

    Tanh Jeazet, Harold B; Staudt, Claudia; Janiak, Christoph

    2012-12-14

    Mixed-matrix membranes (MMMs) with metal-organic frameworks (MOFs) as additives (fillers) exhibit enhanced gas permeabilities and possibly also selectivities when compared to the pure polymer. Polyimides (Matrimid®) and polysulfones are popular polymer matrices for MOF fillers. Presently investigated MOFs for MMMs include [Cu(SiF(6))(4,4'-BIPY)(2)], [Cu(3)(BTC)(2)(H(2)O)(3)] (HKUST-1, Cu-BTC), [Cu(BDC)(DMF)], [Zn(4)O(BDC)(3)] (MOF-5), [Zn(2-methylimidazolate)(2)] (ZIF-8), [Zn(purinate)(2)] (ZIF-20), [Zn(2-carboxyaldehyde imidazolate)(2)] (ZIF-90), Mn(HCOO)(2), [Al(BDC)(μ-OH)] (MIL-53(Al)), [Al(NH(2)-BDC)(μ-OH)] (NH(2)-MIL-53(Al)) and [Cr(3)O(BDC)(3)(F,OH)(H(2)O)(2)] (MIL-101) (4,4'-BIPY = 4,4'-bipyridine, BTC = benzene-1,3,5-tricarboxylate, BDC = benzene-1,4-dicarboxylate, terephthalate). MOF particle adhesion to polyimide and polysulfone organic polymers does not represent a problem. MOF-polymer MMMs are investigated for the permeability of the single gases H(2), N(2), O(2), CH(4), CO(2) and of the gas mixtures O(2)/N(2), H(2)/CH(4), CO(2)/CH(4), H(2)/CO(2), CH(4)/N(2) and CO(2)/N(2) (preferentially permeating gas named first). Permeability increases can be traced to the MOF porosity. Since the porosity of MOFs can be tuned very precisely, which is not possible with polymeric material, MMMs offer the opportunity of significantly increasing the selectivity compared to the pure polymeric matrix. Additionally in most of the cases the permeability is increased for MMM membranes compared to the pure polymer. Addition of MOFs to polymers in MMMs easily yields performances similar to the best polymer membranes and gives higher selectivities than those reported to date for any pure MOF membrane for the same gas separation. MOF-polymer MMMs allow for easier synthesis and handability compared to pure MOF membranes.

  19. Mixed Matrix Membranes of Boron Icosahedron and Polymers of Intrinsic Microporosity (PIM-1) for Gas Separation.

    Science.gov (United States)

    Khan, Muntazim Munir; Shishatskiy, Sergey; Filiz, Volkan

    2018-01-02

    This work reports on the preparation and gas transport performance of mixed matrix membranes (MMMs) based on the polymer of intrinsic microporosity (PIM-1) and potassium dodecahydrododecaborate (K₂B 12 H 12 ) as inorganic particles (IPs). The effect of IP loading on the gas separation performance of these MMMs was investigated by varying the IP content (2.5, 5, 10 and 20 wt %) in a PIM-1 polymer matrix. The derived MMMs were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), single gas permeation tests and sorption measurement. The PIM1/K₂B 12 H 12 MMMs show good dispersion of the IPs (from 2.5 to 10 wt %) in the polymer matrix. The gas permeability of PIM1/K₂B 12 H 12 MMMs increases as the loading of IPs increases (up to 10 wt %) without sacrificing permselectivity. The sorption isotherm in PIM-1 and PIM1/K₂B 12 H 12 MMMs demonstrate typical dual-mode sorption behaviors for the gases CO₂ and CH₄.

  20. Amodiaquine polymeric membrane electrode.

    Science.gov (United States)

    Malongo, T Kimbeni; Blankert, B; Kambu, O; Amighi, K; Nsangu, J; Kauffmann, J-M

    2006-04-11

    The construction and electrochemical response characteristics of two types of poly(vinyl chloride) (PVC) membrane sensors for the determination of amodiaquine hydrochloride (ADQ.2HCl) are described. The sensing membrane comprised an ion-pair formed between the cationic drug and sodium tetraphenyl borate (NaTPB) or potassium tetrakis(4-chlorophenyl) borate (KTCPB) in a plasticized PVC matrix. Eight PVC membrane ion-selective electrodes were fabricated and studied. Several plasticizers were studied namely, dioctyl phthalate (DOP), 2-nitrophenyl octyl ether (NPOE), dioctyl phenylphosphonate (DOPP) and bis(2-ethylhexyl)adipate (EHA). The sensors display a fast, stable and near-Nernstian response over a relative wide ADQ concentration range (3.2 x 10(-6) to 2.0 x 10(-2) M), with slopes comprised between 28.5 and 31.4 mV dec(-1) in a pH range comprised between pH 3.7 and 5.5. The assay of amodiaquine hydrochloride in pharmaceutical dosage forms using one of the proposed sensors gave average recoveries of 104.3 and 99.9 with R.S.D. of 0.3 and 0.6% for tablets (Malaritab) and a reconstituted powder containing ADQ.2HCl, respectively. The sensor was also used for dissolution profile studies of two drug formulations. The sensor proved to have a good selectivity for ADQ.2HCl over some inorganic and organic compounds, however, berberine chloride interfered significantly. The results were validated by comparison with a spectrophotometric assay according to the USP pharmacopoeia.

  1. Characterization and fuel cell performance analysis of polyvinylalcohol-mordenite mixed-matrix membranes for direct methanol fuel cell use

    Energy Technology Data Exchange (ETDEWEB)

    Uctug, Fehmi Goerkem, E-mail: gorkem.uctug@bahcesehir.edu.t [University of Manchester, School of Chemical Engineering and Analytical Science, M60 1QD (United Kingdom); Holmes, Stuart M. [University of Manchester, School of Chemical Engineering and Analytical Science, M60 1QD (United Kingdom)

    2011-10-01

    Highlights: > We investigated the availability of PVA-mordenite membranes for DMFC use. > We measured the methanol permeability of PVA-mordenite membranes via pervaporation. > We did the fuel cell testing of these membranes, which had not been done before. > We showed that PVA-mordenite membranes have poorer DMFC performance than Nafion. > Membrane performance can be improved by increasing the proton conductivity of PVA. - Abstract: Polyvinylalcohol-mordenite (PVA-MOR) mixed matrix membranes were synthesized for direct methanol fuel cell (DMFC) use. For the structural and the morphological characterization, Scanning Electron Microscopy and Thermal Gravimetric Analysis methods were used. Zeolite distribution within the polymer matrix was found to be homogeneous. An impedance spectroscope was used to measure the proton conductivity. In order to obtain information about methanol permeation characteristics, swelling tests and a series of pervaporation experiments were carried out. 60-40 wt% PVA-MOR membranes were found to give the optimum transport properties. Proton conductivity of these membranes was found to be slightly lower than that of Nafion117{sup TM} whereas their methanol permeability was at least two orders of magnitude lower than Nafion117{sup TM}. DMFC performance of the PVA-MOR membranes was also measured. The inferior DMFC performance of PVA-MOR membranes was linked to drying in the fuel cell medium and the consequent proton conductivity loss. Their performance was improved by adding a dilute solution of sulfuric acid into the feed methanol solution. Future studies on the improvement of the proton conductivity of PVA-MOR membranes, especially via sulfonation of the polymer matrix, can overcome the low-performance problem associated with insufficient proton conductivity.

  2. Characterization and fuel cell performance analysis of polyvinylalcohol-mordenite mixed-matrix membranes for direct methanol fuel cell use

    International Nuclear Information System (INIS)

    Uctug, Fehmi Goerkem; Holmes, Stuart M.

    2011-01-01

    Highlights: → We investigated the availability of PVA-mordenite membranes for DMFC use. → We measured the methanol permeability of PVA-mordenite membranes via pervaporation. → We did the fuel cell testing of these membranes, which had not been done before. → We showed that PVA-mordenite membranes have poorer DMFC performance than Nafion. → Membrane performance can be improved by increasing the proton conductivity of PVA. - Abstract: Polyvinylalcohol-mordenite (PVA-MOR) mixed matrix membranes were synthesized for direct methanol fuel cell (DMFC) use. For the structural and the morphological characterization, Scanning Electron Microscopy and Thermal Gravimetric Analysis methods were used. Zeolite distribution within the polymer matrix was found to be homogeneous. An impedance spectroscope was used to measure the proton conductivity. In order to obtain information about methanol permeation characteristics, swelling tests and a series of pervaporation experiments were carried out. 60-40 wt% PVA-MOR membranes were found to give the optimum transport properties. Proton conductivity of these membranes was found to be slightly lower than that of Nafion117 TM whereas their methanol permeability was at least two orders of magnitude lower than Nafion117 TM . DMFC performance of the PVA-MOR membranes was also measured. The inferior DMFC performance of PVA-MOR membranes was linked to drying in the fuel cell medium and the consequent proton conductivity loss. Their performance was improved by adding a dilute solution of sulfuric acid into the feed methanol solution. Future studies on the improvement of the proton conductivity of PVA-MOR membranes, especially via sulfonation of the polymer matrix, can overcome the low-performance problem associated with insufficient proton conductivity.

  3. Studies on heat shrinkage PVC tubes

    International Nuclear Information System (INIS)

    Pyun, Hyung Chick; Kim, Ki Yup; Nho, Young Chang

    1991-01-01

    Radiation crosslinking of PVC was investigated for the purpose of obtaining a suitable formulation for heat shrinkable tube. PVC was not only compounded with various crosslinking agents and plasticizers to evaluate their effects on the radiation sensitivity, heat shrinkable property and other mechanical properties, but also mixed with NBR, crosslinking agents and plasticizers to obtain efficient crosslinking yield and suitable mechanical properties for heat shrinkable tube. Gel yield of PVC increased with increasing unsaturation levels per molecular weight of crosslinking agents. Among crosslinking agents tested, TMPTMA with three unsaturated groups showed highest gel yield, while PVC containing NBR was more sensitive to crosslinking than PVC itself regardless the types of crosslinking agents and plasticizers. Tensile strength was increased with increasing radiation dose and gel percent, but elongation decreased. It was found that gel percent was increased with increasing radiation dose, heat transformation was decreased with increasing gel percent. When NBR was mixed with PVC, the radiation dosage required for enhancing yield of gel percent and heat transformation were found to be much smaller comparing with the case containing no NBR. Therefore, the addition of NBR to PVC was very effective to increase heat-resisting property of PVC. Heat shrinkage was not much varied with radiation dose, the types of crosslinking agents and plasticizers, but it was increased remarkably with decreasing stretching temperature and increasing annealing temperature. (Author)

  4. Australia slaps duties on PVC imports

    International Nuclear Information System (INIS)

    Young, I.

    1992-01-01

    The Australian Anti-Dumping Authority (ADA0) has imposed dumping duties on imports of polyvinyl chloride (PVC) resin from seven countries and on certain expanded polystyrene (EPS) beads from Korea and Singapore. The decisions come at the end of two separate investigations begun earlier this year. In its first finding, the ADA concluded that there has been dumping of PVC resin from Canada, China, France, Japan, Norway, Saudi Arabia, and Thailand, which has caused and threatens to cause material injury to the domestic PVC industry. An eighth country, Romania, was found not to have been exporting PVC to Australia. The case is the second of its kind in Australia focusing on PVC. In December 1991 the ADA found in favor of local producer sin a dumping complaint against Argentina, Brazil, Hungary, Israel, Korea, Mexico, Poland, Singapore, Taiwan, and the US

  5. Study on the Fouling Behavior of Polyethylene and Silica Nanoparticles Mixed Matrix Membranes in Filtration of Humic Acid Solution

    Directory of Open Access Journals (Sweden)

    Ali Akbari

    2016-09-01

    Full Text Available Because most contaminants in water create strong interactions with hydrophobic surfaces, there are usually problems such as flux decline and pore blocking in polyethylene (PE membranes due to irreversible adsorption of foulants on their intrinsic hydrophobic surface. Therefore, in this work, attempts were made to improve the properties of PE membranes in terms of water flux and membrane fouling resistance by dispersion of silica nanoparticles (NPs. First, NPs were synthesized by sol-gel method at two concentrations of ammonia (0.5 and 1 mol/L. The synthesized NPs with smaller size were used to fabricate the mixed matrix PE membranes containing 0, 0.5, 1 and 2 wt% NPs. FE-SEM and EDX analyses were employed to evaluate the morphology and structure of the fabricated membranes and confirmed the presence of NPs in the membranes matrix. The results of pure water flux test revealed that the membrane containing 1 wt% NPs displayed the maximum flux of 30 L/m2.h. Furthermore, the performance and fouling behaviors of membranes during filtration of humic acid solution, one of the most important contaminants of water resources, were studied using a classical fouling model. Fouling mechanism analysis showed that for neat and NPs-embedded membranes containing 0.5 and 2 wt% NPs, the best fit of the data was obtained by cake layer formation as well as the intermediate blocking mechanisms. However, the best fit of the experimental data of NPs-embedded membrane containing 1 wt% occurred with only cake layer formation mechanism. The investigation on membrane fouling resistance showed that 1 wt% NPs-embedded membrane displayed 58% maximum flux recovery and 52% reversibility to total fouling ratio, respectively.

  6. Effects of silica composition on gas permeability of ENR/PVC ...

    African Journals Online (AJOL)

    At higher SiO2 loadings, the mechanical strength of the membrane decreased due to the agglomeration of SiO2 particles. Gas permeation test was done on ENR/PVC/SiO2 membranes using NO2 gas and CO2 gas. The permeability of both gasses increased with the amount of SiO2 added to the membrane, which attributed ...

  7. Localized ridge defect augmentation using human pericardium membrane and demineralized bone matrix.

    Science.gov (United States)

    Vidyadharan, Arun Kumar; Ravindran, Anjana

    2014-01-01

    Patient wanted to restore her lost teeth with implants in the lower left first molar and second premolar region. Cone beam computerized tomography (CBCT) revealed inadequate bone width and height around future implant sites. The extraction socket of second premolar area revealed inadequate socket healing with sparse bone fill after 4 months of extraction. To evaluate the clinical feasibility of using a collagen physical resorbable barrier made of human pericardium (HP) to augment localized alveolar ridge defects for the subsequent placement of dental implants. Ridge augmentation was done in the compromised area using Puros® demineralized bone matrix (DBM) Putty with chips and an HP allograft membrane. Horizontal (width) and vertical hard tissue measurements with CBCT were recorded on the day of ridge augmentation surgery, 4 month and 7 months follow-up. Intra oral periapical taken 1 year after implant installation showed minimal crestal bone loss. Bone volume achieved through guided bone regeneration was a gain of 4.8 mm horizontally (width) and 6.8 mm vertically in the deficient ridge within a period of 7 months following the procedure. The results suggested that HP Allograft membrane may be a suitable component for augmentation of localized alveolar ridge defects in conjunction with DBM with bone chips.

  8. Computational Screening of MOF-Based Mixed Matrix Membranes for CO2/N2 Separations

    Directory of Open Access Journals (Sweden)

    Zeynep Sumer

    2016-01-01

    Full Text Available Atomically detailed simulations were used to examine CO2/N2 separation potential of metal organic framework- (MOF- based mixed matrix membranes (MMMs in this study. Gas permeability and selectivity of 700 new MMMs composed of 70 different MOFs and 10 different polymers were calculated for CO2/N2 separation. This is the largest number of MOF-based MMMs for which computational screening is done to date. Selecting the appropriate MOFs as filler particles in polymers resulted in MMMs that have higher CO2/N2 selectivities and higher CO2 permeabilities compared to pure polymer membranes. We showed that, for polymers that have low CO2 permeabilities but high CO2 selectivities, the identity of the MOF used as filler is not important. All MOFs enhanced the CO2 permeabilities of this type of polymers without changing their selectivities. Several MOF-based MMMs were identified to exceed the upper bound established for polymers. The methods we introduced in this study will create many opportunities to select the MOF/polymer combinations with useful properties for CO2 separation applications.

  9. Mixed Matrix Membranes for O2/N2 Separation: The Influence of Temperature

    Directory of Open Access Journals (Sweden)

    Ana Fernández-Barquín

    2016-05-01

    Full Text Available In this work, mixed matrix membranes (MMMs composed of small-pore zeolites with various topologies (CHA (Si/Al = 5, LTA (Si/Al = 1 and 5, and Rho (Si/Al = 5 as dispersed phase, and the hugely permeable poly(1-trimethylsilyl-1-propyne (PTMSP as continuous phase, have been synthesized via solution casting, in order to obtain membranes that could be attractive for oxygen-enriched air production. The O2/N2 gas separation performance of the MMMs has been analyzed in terms of permeability, diffusivity, and solubility in the temperature range of 298–333 K. The higher the temperature of the oxygen-enriched stream, the lower the energy required for the combustion process. The effect of temperature on the gas permeability, diffusivity, and solubility of these MMMs is described in terms of the Arrhenius and Van’t Hoff relationships with acceptable accuracy. Moreover, the O2/N2 permselectivity of the MMMs increases with temperature, the O2/N2 selectivities being considerably higher than those of the pure PTMSP. In consequence, most of the MMMs prepared in this work exceeded the Robeson’s upper bound for the O2/N2 gas pair in the temperature range under study, with not much decrease in the O2 permeabilities, reaching O2/N2 selectivities of up to 8.43 and O2 permeabilities up to 4,800 Barrer at 333 K.

  10. Modeling the Effects of Interfacial Characteristics on Gas Permeation Behavior of Nanotube-Mixed Matrix Membranes.

    Science.gov (United States)

    Chehrazi, Ehsan; Sharif, Alireza; Omidkhah, Mohammadreza; Karimi, Mohammad

    2017-10-25

    Theoretical approaches that accurately predict the gas permeation behavior of nanotube-containing mixed matrix membranes (nanotube-MMMs) are scarce. This is mainly due to ignoring the effects of nanotube/matrix interfacial characteristics in the existing theories. In this paper, based on the analogy of thermal conduction in polymer composites containing nanotubes, we develop a model to describe gas permeation through nanotube-MMMs. Two new parameters, "interfacial thickness" (a int ) and "interfacial permeation resistance" (R int ), are introduced to account for the role of nanotube/matrix interfacial interactions in the proposed model. The obtained values of a int , independent of the nature of the permeate gas, increased by increasing both the nanotubes aspect ratio and polymer-nanotube interfacial strength. An excellent correlation between the values of a int and polymer-nanotube interaction parameters, χ, helped to accurately reproduce the existing experimental data from the literature without the need to resort to any adjustable parameter. The data includes 10 sets of CO 2 /CH 4 permeation, 12 sets of CO 2 /N 2 permeation, 3 sets of CO 2 /O 2 permeation, and 2 sets of CO 2 /H 2 permeation through different nanotube-MMMs. Moreover, the average absolute relative errors between the experimental data and the predicted values of the proposed model are very small (less than 5%) in comparison with those of the existing models in the literature. To the best of our knowledge, this is the first study where such a systematic comparison between model predictions and such extensive experimental data is presented. Finally, the new way of assessing gas permeation data presented in the current work would be a simple alternative to complex approaches that are usually utilized to estimate interfacial thickness in polymer composites.

  11. A reciclagem de PVC no Brasil

    OpenAIRE

    Piva,Ana Magda; Bahiense Neto,Miguel; Wiebeck,Hélio

    1999-01-01

    Esta pesquisa discute as possibilidades práticas da reciclagem de PVC. Na reciclagem de polímeros, a do PVC representa uma importante parcela. PVC é um polímero que é usado em uma ampla faixa de produtos: filmes, fios, cabos, em compostos para uma variedade de formas. A reciclagem é uma técnica vantajosa, capaz de reproduzir as propriedades do polímero original, no polímero reciclado e isto em condições razoavelmente econômicas. A tecnologia brasileira, em relação a produtos reciclados, apres...

  12. Fabrication of high flux and antifouling mixed matrix fumarate-alumoxane/PAN membranes via electrospinning for application in membrane bioreactors

    Science.gov (United States)

    Moradi, Golshan; Zinadini, Sirus; Rajabi, Laleh; Dadari, Soheil

    2018-01-01

    The nanofibrous Polyacrylonitrile (PAN) membranes embedded with fumarate-alumoxane (Fum-A) nanoparticles were prepared via electrospinning technique as high flux and antifouling membranes for membrane bioreactor (MBR) applications. The effect of Fum-A nanoparticles on membrane morphology, surface hydrophilicity, pure water flux, effluent turbidity and the antifouling property was investigated. Fum-A is a carboxylate-alumoxane nanoparticle covered by extra hydroxyl and carboxylate groups on its surface. By embedding Fum-A nanoparticles into the spinning solution, the surface hydrophilicity and pure water flux of the resulted membranes were improved. The smooth surface of fibers at the low amount of nanoparticles and the agglomeration of nanoparticles at their high concentration were shown in SEM images of the membranes surface. The energy dispersive spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) analysis of the prepared Fum-A/PAN membrane confirmed the presence of carboxylate and hydroxyl functional groups of Fum-A nanoparticles on the surface of the Fum-A nanoparticles containing membrane. The results obtained from the filtration of activated sludge suspension revealed that by addition of a low amount of Fum-A nanoparticles, the irreversible fouling was significantly decreased due to the higher hydrophilicity. The Fum-A/PAN membranes showed superior permeate flux and antifouling properties compared to bare electrospun PAN membrane. Finally, 2 wt.% Fum-A/PAN membrane exhibited the highest FRR of 96% and the lowest irreversible fouling of 4% with excellent durability of antifouling property during twenty repeated activated sludge filtrations.

  13. Revealing Transient Concentration of CO2 in a Mixed Matrix Membrane by IR Microimaging and Molecular Modeling

    KAUST Repository

    Hwang, Seungtaik

    2018-02-21

    Through IR microimaging the spatially and temporally resolved development of the CO2 concentration in a ZIF-8@6FDA-DAM mixed matrix membrane was visualized during transient adsorption. By recording the evolution of the CO2 concentration, it is observed that the CO2 molecules propagate from the ZIF-8 filler, which acts as a transport

  14. Revealing Transient Concentration of CO2 in a Mixed Matrix Membrane by IR Microimaging and Molecular Modeling

    KAUST Repository

    Hwang, Seungtaik; Semino, Rocio; Seoane, Beatriz; Zahan, Marufa; Chmelik, Christian; Valiullin, Rustem; Bertmer, Marko; Haase, Jü rgen; Kapteijn, Freek; Gascon, Jorge; Maurin, Guillaume; Kä rger, Jö rg

    2018-01-01

    Through IR microimaging the spatially and temporally resolved development of the CO2 concentration in a ZIF-8@6FDA-DAM mixed matrix membrane was visualized during transient adsorption. By recording the evolution of the CO2 concentration, it is observed that the CO2 molecules propagate from the ZIF-8 filler, which acts as a transport

  15. The central role of vascular extracellular matrix and basement membrane remodeling in metabolic syndrome and type 2 diabetes: the matrix preloaded

    Directory of Open Access Journals (Sweden)

    Tyagi Suresh C

    2005-06-01

    Full Text Available Abstract The vascular endothelial basement membrane and extra cellular matrix is a compilation of different macromolecules organized by physical entanglements, opposing ionic charges, chemical covalent bonding, and cross-linking into a biomechanically active polymer. These matrices provide a gel-like form and scaffolding structure with regional tensile strength provided by collagens, elasticity by elastins, adhesiveness by structural glycoproteins, compressibility by proteoglycans – hyaluronans, and communicability by a family of integrins, which exchanges information between cells and between cells and the extracellular matrix of vascular tissues. Each component of the extracellular matrix and specifically the capillary basement membrane possesses unique structural properties and interactions with one another, which determine the separate and combined roles in the multiple diabetic complications or diabetic opathies. Metabolic syndrome, prediabetes, type 2 diabetes mellitus, and their parallel companion (atheroscleropathy are associated with multiple metabolic toxicities and chronic injurious stimuli. The adaptable quality of a matrix or form genetically preloaded with the necessary information to communicate and respond to an ever-changing environment, which supports the interstitium, capillary and arterial vessel wall is individually examined.

  16. Age-related collagen turnover of the interstitial matrix and basement membrane: Implications of age- and sex-dependent remodeling of the extracellular matrix

    DEFF Research Database (Denmark)

    Kehlet, Stephanie N.; Willumsen, Nicholas; Armbrecht, Gabriele

    2018-01-01

    The extracellular matrix (ECM) plays a vital role in maintaining normal tissue function. Collagens are major components of the ECM and there is a tight equilibrium between degradation and formation of these proteins ensuring tissue health and homeostasis. As a consequence of tissue turnover, small...... collagen fragments are released into the circulation, which act as important biomarkers in the study of certain tissue-related remodeling factors in health and disease. The aim of this study was to establish an age-related collagen turnover profile of the main collagens of the interstitial matrix (type I...... an increased turnover. In summary, collagen turnover is affected by age and sex with the interstitial matrix and the basement membrane being differently regulated. The observed changes needs to be accounted for when measuring ECM related biomarkers in clinical studies....

  17. MOF-mixed matrix membranes : precise dispersion of MOF particles with better compatibility via a particle fusion approach for enhanced gas separation properties

    NARCIS (Netherlands)

    Shahid, Salman; Nijmeijer, Kitty; Nehache, Sabrina; Vankelecom, Ivo; Deratani, Andre; Quemener, Damien

    2015-01-01

    Mixed matrix membranes (MMMs) incorporating conventional fillers frequently suffer from insufficient adhesion between the polymer matrix and the fillers. This often results in the formation of non-selective voids at the filler/polymer interface, which decreases the performance of the membrane. A

  18. MOF-mixed matrix membranes: Precise dispersion of MOF particles with better compatibility via a particle fusion approach for enhanced gas separation properties

    NARCIS (Netherlands)

    Shahid, S.; Nijmeijer, Dorothea C.; Nehache, Sabrina; Vankelecom, Ivo; Deratani, Andre; Quemener, Damien

    2015-01-01

    Mixed matrix membranes (MMMs) incorporating conventional fillers frequently suffer from insufficient adhesion between the polymer matrix and the fillers. This often results in the formation of non-selective voids at the filler/polymer interface, which decreases the performance of the membrane. A

  19. Mixed-linker zeolitic imidazolate framework mixed-matrix membranes for aggressive CO2 separation from natural gas

    KAUST Repository

    Thompson, Joshua A.

    2014-07-01

    Zeolitic imidazolate framework (ZIF) materials are a promising subclass of metal-organic frameworks (MOF) for gas separations. However, due to the deleterious effects of gate-opening phenomena associated with organic linker rotation near the limiting pore apertures of ZIFs, there have been few demonstrations of improved gas separation properties over pure polymer membranes when utilizing ZIF materials in composite membranes for CO2-based gas separations. Here, we report a study of composite ZIF/polymer membranes, containing mixed-linker ZIF materials with ZIF-8 crystal topologies but composed of different organic linker compositions. Characterization of the mixed-linker ZIFs shows that the mixed linker approach offers control over the porosity and pore size distribution of the materials, as determined from nitrogen physisorption and Horváth-Kawazoe analysis. Single gas permeation measurements on mixed-matrix membranes reveal that inclusion of mixed-linker ZIFs yields membranes with better ideal CO2/CH4 selectivity than membranes containing ZIF-8. This improvement is shown to likely occur from enhancement in the diffusion selectivity of the membranes associated with controlling the pore size distribution of the ZIF filler. Mixed-gas permeation experiments show that membranes with mixed-linker ZIFs display an effective plasticization resistance that is not typical of the pure polymeric matrix. Overall, we demonstrate that mixed-linker ZIFs can improve the gas separation properties in composite membranes and may be applicable to aggressive CO2 concentrations in natural gas feeds. © 2013 Elsevier Inc. All rights reserved.

  20. Discoloration of plasticized PVC upon irradiation

    International Nuclear Information System (INIS)

    Kojima, Keiichi; Ueno, Keiji; Kumafuji, Hisao.

    1981-01-01

    The effects of the factors on the discoloration of PVC cross-linked by electron irradiation, such as irradiation dose, the polymerization degree of PVC resin, plasticizers and stabilizers, were studied. The composition of the plasticized PVC used for the experiment was 100 PHR of PVC, 50 PHR of plasticizer, 5 PHR of stabilizer and 5 PHR of cross-linking agent (TMPMA). Three samples with the different degree of polymerization of the PVC resin were used, namely 750, 1050 and 2600. As the plasticizers, phthalic acid esters (DBP, DOP, DIDP), trimellitic acid esters (TOTM, n-TOTM), fatty acid esters (DOS, DOZ), polyester and epoxy group plasticizers were used. The irradiation dose for the test was 3, 6 and 12 Mrad. The experimental results are summarized as follows. As the electron irradiation dose was higher, the resultant discoloration was more remarkable, and the optimum irradiation dose was below 6 Mrad. The degree of polymerization of the PVC resin did not affect the irradiation discoloration. However it was noticed that the cross-linking efficiency was better as the degree of polymerization was higher. The cross-linking efficiency was better as the content of plasticizer was more. The fatty acid esters and epoxy groups showed less discoloration and better cross-linking efficiency. Tin and barium-zinc stabilizers were good. (Kako, I.)

  1. Identification of membrane-type 1 matrix metalloproteinase tyrosine phosphorylation in association with neuroblastoma progression

    International Nuclear Information System (INIS)

    Nyalendo, Carine; Sartelet, Hervé; Barrette, Stéphane; Ohta, Shigeru; Gingras, Denis; Béliveau, Richard

    2009-01-01

    Neuroblastoma is a pediatric tumor of neural crest cells that is clinically characterized by its variable evolution, from spontaneous regression to malignancy. Despite many advances in neuroblastoma research, 60% of neuroblastoma, which are essentially metastatic cases, are associated with poor clinical outcome due to the lack of effectiveness of current therapeutic strategies. Membrane-type 1 matrix metalloproteinase (MT1-MMP, MMP-14), an enzyme involved in several steps in tumor progression, has previously been shown to be associated with poor clinical outcome for neuroblastoma. Based on our recent demonstration that MT1-MMP phosphorylation is involved in the growth of fibrosarcoma tumors, we examined the potential role of phosphorylated MT1-MMP in neuroblastoma progression. Tyrosine phosphorylated MT1-MMP was immunostained on tissue microarray samples from 55 patients with neuroblastoma detected by mass screening (known to be predominantly associated with favourable outcome), and from 234 patients with standard diagnosed neuroblastoma. In addition, the effects of a non phosphorylable version of MT1-MMP on neuroblastoma cell migration and proliferation were investigated within three-dimensional collagen matrices. Although there is no correlation between the extent of tyrosine phosphorylation of MT1-MMP (pMT1-MMP) and MYCN amplification or clinical stage, we observed greater phosphorylation of pMT1-MMP in standard neuroblastoma, while it is less evident in neuroblastoma from mass screening samples (P = 0.0006) or in neuroblastoma samples from patients younger than one year (P = 0.0002). In vitro experiments showed that overexpression of a non-phosphorylable version of MT1-MMP reduced MT1-MMP-mediated neuroblastoma cell migration and proliferation within a three-dimensional type I collagen matrix, suggesting a role for the phosphorylated enzyme in the invasive properties of neuroblastoma cells. Overall, these results suggest that tyrosine phosphorylated MT1-MMP

  2. Mixed-Matrix Membranes containing an Azine-Linked Covalent Organic Framework: Influence of the polymeric matrix on Post-Combustion CO 2 -capture

    KAUST Repository

    Shan, Meixia

    2017-12-07

    The use of an azine-linked covalent organic framework (ACOF-1) as filler in mixed-matrix membranes (MMMs) has been studied for the separation of CO2 from N2. To better understand the mechanisms that govern separation in complex composites, MMMs were prepared with different loadings of ACOF-1 and three different polymers as continuous phase: low flux-mid selectivity Matrimid®, mid flux-high selectivity Polyactive™ and high flux-low selectivity 6FDA:DAM. The homogeneous distribution of ACOF-1 together with the good adhesion between the ACOF-1 particles and the polymer matrices were confirmed by scanning electron microscopy. In mixed-gas CO2/N2 separation a clear influence of the polymer used was observed on the performance of the composite membranes. While for Matrimid® and 6FDA:DAM an overall enhancement of the polymer\\'s separation properties could be achieved, in case of Polyactive™ penetration of the more flexible polymer into the COF porosity resulted in a decreased membrane permeability. The best improvement was obtained for Matrimid®-based MMMs, for which a selectivity increase from 29 to 35, together with an enhancement in permeability from 9.5 to 17.7 Barrer for 16wt% COF loading, was observed. Our results demonstrate that the combination of the filler-polymeric matrix pair chosen is crucial. For a given filler the polymer performance improvement strongly depends on the polymeric matrix selected, where a good match between the discontinuous and continuous phase, both in the terms of compatibility and gas separation properties, is necessary to optimize membrane performance.

  3. [Morphology of basement membrane and associated matrix proteins in normal and pathological tissues].

    Science.gov (United States)

    Nerlich, A

    1995-01-01

    Basement membranes (BM) are specialized structures of the extracellular matrix. Their composition is of particular importance for the maintenance of normal morphological and functional properties of a multitude of organs and tissue systems and it is thus required for regular homeostasis of body function. Generally, they possess three main functions, i.e. participation in the maintenance of tissue structure, control of fluid and substrate exchange, and regulation of cell growth and differentiation. BMs are made up by various components which are in part specifically localized within the BM zone, or which represent ubiquitous matrix constituents with specific quantitative and/or qualitative differences in their localization. On the basis of a thorough immunohistochemical analysis of normal and diseased tissues, we provide here a concept of "functional morphology/pathomorphology" of the different BM components analyzed: 1.) The ubiquitous BM-constituent collagen IV primarily stabilizes the BM-zone and thus represents the "backbone" of the BM providing mechanical strength. Its loss leads to cystic tissue transformation as it is evidenced from the analysis of polycystic nephropathies. Thus, in other cystic tissue transformations a similar formal pathogenesis may be present. 2.) The specific localization of collagen VII as the main structural component of anchoring fibrils underlines the mechanical anchoring function of this collagenous protein. Defects in this protein lead to hereditary epidermolysis. The rapid re-occurrence of epidermal collagen VII during normal human wound healing indicates a quick reconstitution of the mechanical tensile strength of healing wounds. 3.) The BM-specific heparan sulfate proteoglycan (HSPG, Perlecan) with its highly negative anionic charge can be assumed to exert filter control. This assumption is corroborated by the localizatory findings of a preferential deposition of HSPG in endothelial and particularly in glomerular BM. Similarly

  4. Modified ZIF-8 mixed matrix membrane for CO2/CH4 separation

    Science.gov (United States)

    Nordin, Nik Abdul Hadi Md; Ismail, Ahmad Fauzi; Misdan, Nurasyikin; Nazri, Noor Aina Mohd

    2017-10-01

    Tunability of metal-organic frameworks (MOFs) properties enables them to be tailored for specific applications. In this study, zeolitic imidazole framework 8 (ZIF-8), sub-class of MOF, underwent pre-synthesis and post-synthesis modifications. The pre-synthesis modification using GO (ZIF-8/GO) shows slight decrease in textural properties, while the post-synthesis modification using amine solution (ZIF-8/NH2) resulted in superior BET surface area and pore volume. Mixed matrix membranes (MMMs) derived from polysulfone (PSf) and the modified ZIF-8s were then prepared via dry/wet phase inversion. The polymer chain flexibility of the resulted MMMs shows rigidification, where ZIF-8/NH2 as filler resulting higher rigidification compared to ZIF-8/GO. The MMMs were further subjected to pure CO2 and CH4 gas permeation experiments. The PSf/ZIF-8/NH2 shows superior CO2/CH4 selectivity (88% increased) while sacrificing CO2 permeance due to combination of severe polymer chain rigidification and the presence of CO2-philic group, amine. Whereas, the PSf/ZIF-8/GO possess 64% increase in CO2 permeance without notable changes in CO2/CH4 selectivity.

  5. CO2–CH4 permeation in high zeolite 4A loading mixed matrix membranes

    KAUST Repository

    Adams, Ryan T.

    2011-02-01

    Mixed matrix membranes (MMMs) with low particle loadings have been shown to improve the properties of pure polymers for many gas separations. Comparatively few reports have been made for high particle loading (≥50vol.%) MMMs. In this work, CO2-CH4 feeds were used to study the potential of 50vol.% zeolite 4A-poly(vinyl acetate) (PVAc) MMMs for natural gas separations. A low CO2 partial pressure mixed feed probed MMM performance below the plasticization pressure of PVAc and a high CO2 partial pressure mixed feed probed MMM performance at industrially relevant conditions above the plasticization pressure.Under both mixed feed conditions at 35°C, substantial improvements in overall separation performance were observed. At low CO2 partial pressures, CO2 permeability roughly doubled with a nearly 50% increase in selectivity versus pure PVAc under the same conditions. For the high CO2 partial pressure feed, CO2 permeability remained effectively unchanged with a 63% increase in selectivity versus pure PVAc. Surprisingly, the performance of these PVAc based MMMs approached the properties of current " upper bound" polymers. Overall, this work shows that significantly improved performance MMMs can be made with traditional techniques from a low cost, low performance polymer without costly adhesion promoters. © 2010.

  6. CO2–CH4 permeation in high zeolite 4A loading mixed matrix membranes

    KAUST Repository

    Adams, Ryan T.; Lee, Jong Suk; Bae, Tae-Hyun; Ward, Jason K.; Johnson, J.R.; Jones, Christopher W.; Nair, Sankar; Koros, William J.

    2011-01-01

    Mixed matrix membranes (MMMs) with low particle loadings have been shown to improve the properties of pure polymers for many gas separations. Comparatively few reports have been made for high particle loading (≥50vol.%) MMMs. In this work, CO2-CH4 feeds were used to study the potential of 50vol.% zeolite 4A-poly(vinyl acetate) (PVAc) MMMs for natural gas separations. A low CO2 partial pressure mixed feed probed MMM performance below the plasticization pressure of PVAc and a high CO2 partial pressure mixed feed probed MMM performance at industrially relevant conditions above the plasticization pressure.Under both mixed feed conditions at 35°C, substantial improvements in overall separation performance were observed. At low CO2 partial pressures, CO2 permeability roughly doubled with a nearly 50% increase in selectivity versus pure PVAc under the same conditions. For the high CO2 partial pressure feed, CO2 permeability remained effectively unchanged with a 63% increase in selectivity versus pure PVAc. Surprisingly, the performance of these PVAc based MMMs approached the properties of current " upper bound" polymers. Overall, this work shows that significantly improved performance MMMs can be made with traditional techniques from a low cost, low performance polymer without costly adhesion promoters. © 2010.

  7. Enhanced aging properties of HKUST-1 in hydrophobic mixed-matrix membranes for ammonia adsorption.

    Science.gov (United States)

    DeCoste, Jared B; Denny, Michael S; Peterson, Gregory W; Mahle, John J; Cohen, Seth M

    2016-04-21

    Metal-organic frameworks (MOFs) in their free powder form have exhibited superior capacities for many gases when compared to other materials, due to their tailorable functionality and high surface areas. Specifically, the MOF HKUST-1 binds small Lewis bases, such as ammonia, with its coordinatively unsaturated copper sites. We describe here the use of HKUST-1 in mixed-matrix membranes (MMMs) prepared from polyvinylidene difluoride (PVDF) for the removal of ammonia gas. These MMMs exhibit ammonia capacities similar to their hypothetical capacities based on the weight percent of HKUST-1 in each MMM. HKUST-1 in its powder form is unstable toward humid conditions; however, upon exposure to humid environments for prolonged periods of time, the HKUST-1 MMMs exhibit outstanding structural stability, and maintain their ammonia capacity. Overall, this study has achieved all of the critical and combined elements for real-world applications of MOFs: high MOF loadings, fully accessible MOF surfaces, enhanced MOF stabilization, recyclability, mechanical stability, and processability. This study is a critical step in advancing MOFs to a stable, usable, and enabling technology.

  8. Socket Preservation with d-PTFE Membrane: Histologic Analysis of the Newly Formed Matrix at Membrane Removal.

    Science.gov (United States)

    Laurito, Domenico; Cugnetto, Riccardo; Lollobrigida, Marco; Guerra, Fabrizio; Vestri, Annarita; Gianno, Francesca; Bosco, Sandro; Lamazza, Luca; De Biase, Alberto

    This study aimed to evaluate the efficacy of an exposed high-density polytetrafluoroethylene (d-PTFE) membrane in preventing epithelial migration in postextraction sockets. For this purpose, a histologic description of the newly formed soft tissue underlying the membrane is presented. The periodontal status of the adjacent teeth was also evaluated to assess the gingival response. Ten premolar extraction sockets were treated. After tooth extraction, the sockets were filled with nanocrystalline hydroxyapatite and covered with d-PTFE membranes. Subperiosteal pockets were created to ensure the stability of the membranes. Membranes were left intentionally exposed and were atraumatically removed after 28 days. At that time, a bioptic specimen of the newly formed soft tissue under the membranes was taken. All the histologic samples showed a dense connective tissue without epithelial cells and no signs of foreign body reaction. No significant variation of the periodontal indices was observed on the teeth adjacent to the extraction sites. The study results indicate that exposed d-PTFE membranes can prevent epithelial migration in healing sockets without consequences on the periodontal health.

  9. High performance ZIF-8/6FDA-DAM mixed matrix membrane for propylene/propane separations

    KAUST Repository

    Zhang, Chen

    2012-02-01

    We report significantly enhanced propylene/propane (C 3H 6/C 3H 8) selectivity in mixed matrix membranes fabricated using 6FDA-DAM polyimide and a zeolitic imidazolate framework (ZIF-8). Equilibrium isotherms and sorption kinetics of C 3H 6 and C 3H 8 at 35°C were studied on a 200nm commercially available ZIF-8 sample produced by BASF. Mixed matrix dense films were formed with 6FDA-DAM and 200nm BASF ZIF-8 particles. SEM imaging showed generally good adhesion between the ZIF-8 and 6FDA-DAM without the need for surface-treating ZIF-8. Pure gas permeation showed significantly enhanced mixed matrix ZIF-8/6FDA-DAM membrane C 3H 6/C 3H 8 separation performance over the pure 6FDA-DAM membrane performance. A C 3H 6 permeability of 56.2Barrer and C 3H 6/C 3H 8 ideal selectivity of 31.0 was found in ZIF-8/6FDA-DAM mixed matrix membrane with 48.0wt% ZIF-8 loading, which are 258% and 150% higher than the pure 6FDA-DAM membrane, respectively for permeability and selectivity. Permeation properties of C 3H 6 and C 3H 8 in ZIF-8 were back-calculated by the Maxwell model for composite permeability using pure gas permeation data, leading to a C 3H 6 permeability of 277Barrer and C 3H 6/C 3H 8 selectivity of 122. Mixed gas permeation also verified that selectivity enhancements were achievable in mixed gas environment by ZIF-8. © 2011 Elsevier B.V.

  10. High performance ZIF-8/6FDA-DAM mixed matrix membrane for propylene/propane separations

    KAUST Repository

    Zhang, Chen; Dai, Ying; Johnson, Justin R.; Karvan, Oguz; Koros, William J.

    2012-01-01

    We report significantly enhanced propylene/propane (C 3H 6/C 3H 8) selectivity in mixed matrix membranes fabricated using 6FDA-DAM polyimide and a zeolitic imidazolate framework (ZIF-8). Equilibrium isotherms and sorption kinetics of C 3H 6 and C 3H 8 at 35°C were studied on a 200nm commercially available ZIF-8 sample produced by BASF. Mixed matrix dense films were formed with 6FDA-DAM and 200nm BASF ZIF-8 particles. SEM imaging showed generally good adhesion between the ZIF-8 and 6FDA-DAM without the need for surface-treating ZIF-8. Pure gas permeation showed significantly enhanced mixed matrix ZIF-8/6FDA-DAM membrane C 3H 6/C 3H 8 separation performance over the pure 6FDA-DAM membrane performance. A C 3H 6 permeability of 56.2Barrer and C 3H 6/C 3H 8 ideal selectivity of 31.0 was found in ZIF-8/6FDA-DAM mixed matrix membrane with 48.0wt% ZIF-8 loading, which are 258% and 150% higher than the pure 6FDA-DAM membrane, respectively for permeability and selectivity. Permeation properties of C 3H 6 and C 3H 8 in ZIF-8 were back-calculated by the Maxwell model for composite permeability using pure gas permeation data, leading to a C 3H 6 permeability of 277Barrer and C 3H 6/C 3H 8 selectivity of 122. Mixed gas permeation also verified that selectivity enhancements were achievable in mixed gas environment by ZIF-8. © 2011 Elsevier B.V.

  11. Preparation and properties of hybrid direct methanol fuel cell membranes by embedding organophosphorylated titania submicrospheres into a chitosan polymer matrix

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hong [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072 (China); Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072 (China); Hou, Weiqiang; Wang, Jingtao; Xiao, Lulu; Jiang, Zhongyi [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072 (China)

    2010-07-01

    Organophosphorylated titania submicrospheres (OPTi) are prepared and incorporated into a chitosan (CS) matrix to fabricate hybrid membranes with enhanced methanol resistance and proton conductivity for application in direct methanol fuel cells (DMFC). The pristine monodispersed titania submicrospheres (TiO{sub 2}) of controllable particle size are synthesized through a modified sol-gel method and then phosphorylated by amino trimethylene phosphonic acid (ATMP) via chemical adsorption, which is confirmed by XPS, FTIR and TGA. The morphology and thermal property of the hybrid membranes are explored by SEM and TGA. The ionic cross-linking between the -PO{sub 3}H{sub 2} groups on OPTi and the -NH{sub 2} groups on CS lead to better compatibility between the inorganic fillers and the polymer matrix, as well as a decreased fractional free volume (FFV), which is verified by positron annihilation lifetime spectroscopy (PALS). The effects of particle size and content on the methanol permeability, proton conductivity, swelling and FFV of the membranes are investigated. Compared to pure CS membrane, the hybrid membranes exhibit an increased proton conductivity to an acceptable level of 0.01 S cm{sup -1} for DMFC application and a reduced methanol permeability of 5 x 10{sup -7} cm{sup 2} s{sup -1} at a 2 M methanol feed. (author)

  12. Preparation and properties of hybrid direct methanol fuel cell membranes by embedding organophosphorylated titania submicrospheres into a chitosan polymer matrix

    Science.gov (United States)

    Wu, Hong; Hou, Weiqiang; Wang, Jingtao; Xiao, Lulu; Jiang, Zhongyi

    Organophosphorylated titania submicrospheres (OPTi) are prepared and incorporated into a chitosan (CS) matrix to fabricate hybrid membranes with enhanced methanol resistance and proton conductivity for application in direct methanol fuel cells (DMFC). The pristine monodispersed titania submicrospheres (TiO 2) of controllable particle size are synthesized through a modified sol-gel method and then phosphorylated by amino trimethylene phosphonic acid (ATMP) via chemical adsorption, which is confirmed by XPS, FTIR and TGA. The morphology and thermal property of the hybrid membranes are explored by SEM and TGA. The ionic cross-linking between the -PO 3H 2 groups on OPTi and the -NH 2 groups on CS lead to better compatibility between the inorganic fillers and the polymer matrix, as well as a decreased fractional free volume (FFV), which is verified by positron annihilation lifetime spectroscopy (PALS). The effects of particle size and content on the methanol permeability, proton conductivity, swelling and FFV of the membranes are investigated. Compared to pure CS membrane, the hybrid membranes exhibit an increased proton conductivity to an acceptable level of 0.01 S cm -1 for DMFC application and a reduced methanol permeability of 5 × 10 -7 cm 2 s -1 at a 2 M methanol feed.

  13. Membrane-type-3 matrix metalloproteinase (MT3-MMP functions as a matrix composition-dependent effector of melanoma cell invasion.

    Directory of Open Access Journals (Sweden)

    Olga Tatti

    Full Text Available In primary human melanoma, the membrane-type matrix metalloproteinase, MT3-MMP, is overexpressed in the most aggressive nodular-type tumors. Unlike MT1-MMP and MT2-MMP, which promote cell invasion through basement membranes and collagen type I-rich tissues, the function of MT3-MMP in tumor progression remains unclear. Here, we demonstrate that MT3-MMP inhibits MT1-MMP-driven melanoma cell invasion in three-dimensional collagen, while yielding an altered, yet MT1-MMP-dependent, form of expansive growth behavior that phenocopies the formation of nodular cell colonies. In melanoma cell lines originating from advanced primary or metastatic lesions, endogenous MT3-MMP expression was associated with limited collagen-invasive potential. In the cell lines with highest MT3-MMP expression relative to MT1-MMP, collagen-invasive activity was increased following stable MT3-MMP gene silencing. Consistently, MT3-MMP overexpression in cells derived from less advanced superficially spreading melanoma lesions, or in the MT3-MMP knockdown cells, reduced MT1-MMP-dependent collagen invasion. Rather than altering MT1-MMP transcription, MT3-MMP interacted with MT1-MMP in membrane complexes and reduced its cell surface expression. By contrast, as a potent fibrinolytic enzyme, MT3-MMP induced efficient invasion of the cells in fibrin, a provisional matrix component frequently found at tumor-host tissue interfaces and perivascular spaces of melanoma. Since MT3-MMP was significantly upregulated in biopsies of human melanoma metastases, these results identify MT3-MMP as a matrix-dependent modifier of the invasive tumor cell functions during melanoma progression.

  14. Membrane culture and reduced oxygen tension enhances cartilage matrix formation from equine cord blood mesenchymal stromal cells in vitro.

    Science.gov (United States)

    Co, C; Vickaryous, M K; Koch, T G

    2014-03-01

    Ongoing research is aimed at increasing cartilage tissue yield and quality from multipotent mesenchymal stromal cells (MSC) for the purpose of treating cartilage damage in horses. Low oxygen culture has been shown to enhance chondrogenesis, and novel membrane culture has been proposed to increase tissue yield and homogeneity. The objective of this study was to evaluate and compare the effect of reduced oxygen and membrane culture during in vitro chondrogenesis of equine cord blood (CB) MSC. CB-MSC (n = 5 foals) were expanded at 21% oxygen prior to 3-week differentiation in membrane or pellet culture at 5% and 21% oxygen. Assessment included histological examination (H&E, toluidine Blue, immunohistochemistry (IHC) for collagen type I and II), protein quantification by hydroxyproline assay and dimethylmethylene assay, and mRNA analysis for collagen IA1, collagen IIA1, collagen XA1, HIF1α and Sox9. Among treatment groups, 5% membrane culture produced neocartilage most closely resembling hyaline cartilage. Membrane culture resulted in increased wet mass, homogenous matrix morphology and an increase in total collagen content, while 5% oxygen culture resulted in higher GAG and type II collagen content. No significant differences were observed for mRNA analysis. Membrane culture at 5% oxygen produces a comparatively larger amount of higher quality neocartilage. Matrix homogeneity is attributed to a uniform diffusion gradient and reduced surface tension. Membrane culture holds promise for scale-up for therapeutic purposes, for cellular preconditioning prior to cytotherapeutic applications, and for modeling system for gas-dependent chondrogenic differentiation studies. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  15. Downregulation of membrane type-matrix metalloproteinases in the inflamed or injured central nervous system

    Directory of Open Access Journals (Sweden)

    Millward Jason M

    2007-09-01

    Full Text Available Abstract Background Matrix metalloproteinases (MMPs are thought to mediate cellular infiltration in central nervous system (CNS inflammation by cleaving extracellular matrix proteins associated with the blood-brain barrier. The family of MMPs includes 23 proteinases, including six membrane type-MMPs (MT-MMPs. Leukocyte infiltration is an integral part of the pathogenesis of autoimmune inflammation in the CNS, as occurs in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE, as well as in the response to brain trauma and injury. We have previously shown that gene expression of the majority of MMPs was upregulated in the spinal cord of SJL mice with severe EAE induced by adoptive transfer of myelin basic protein-reactive T cells, whereas four of the six MT-MMPs (MMP-15, 16, 17 and 24 were downregulated. The two remaining MT-MMPs (MMP-14 and 25 were upregulated in whole tissue. Methods We used in vivo models of CNS inflammation and injury to study expression of MT-MMP and cytokine mRNA by real-time RT-PCR. Expression was also assessed in microglia sorted from CNS by flow cytometry, and in primary microglia cultures following treatment with IFNγ. Results We now confirm the expression pattern of MT-MMPs in the B6 mouse, independent of effects of adjuvant. We further show expression of all the MT-MMPs, except MMP-24, in microglia. Microglia isolated from mice with severe EAE showed statistically significant downregulation of MMP-15, 17 and 25 and lack of increase in levels of other MT-MMPs. Downregulation of MT-MMPs was also apparent following CNS injury. The pattern of regulation of MT-MMPs in neuroinflammation showed no association with expression of the proinflammatory cytokines TNFα, IL-1β, or IFNγ. Conclusion CNS inflammation and injury leads to downregulation in expression of the majority of MT-MMPs. Microglia in EAE showed a general downregulation of MT-MMPs, and our findings suggest that MT-MMP levels may

  16. Fabrication Parameters of Asymmetric Mixed Matrix Matrimid-MIL-53/PMHS Membrane for CO2/CH4 Separation

    Directory of Open Access Journals (Sweden)

    Fatereh Dorosti

    2017-03-01

    Full Text Available Asymmetrically mixed matrix Matrimid-MIL-53 membranes with silicone cover layer were fabricated. For better understanding of membrane fabrication process, three main parameters of fabrication, Matrimid concentration, silicone concentration and weight percentage of metal organic framework (MIL-53 particles, were optimized by an experimental design method. Cross-section SEM images were used to study the membrane structure and polymer-particles interface. Moreover, thermal resistance of the membranes and the existence of various bonds in them were investigated by FTIR and TGA analyses. The results showed that membranes had porous structure with finger-like morphology. At low and moderate percentages of particles, there were no non-selective voids observed at polymer-particles interface. The thermal resistance of membranes increased with the increase of MIL-53 weight percentage and the destruction temperature of polymer increased from 410°C to 450°C. The permeability tests results showed that the Matrimid (20% wt-MIL-53(15% wt/PMHS (10%wt membrane exhibited the highest level of CO2/CH4 selectivity (23.6. However, in the membrane with 30 wt% particles loading, selectivity decreased due to particles agglomeration and void formation. The experimental design results showed that the concentration of silicone in covering solution had significant effect. CO2 and CH4 permeability decreased and ideal selectivity of CO2/CH4 increased with silicone concentration enhancement. Although the Matrimid concentration had a little effect on CO2/CH4 ideal selectivity, its enhancement increased the selectivity of the gases. The optimization results showed the membrane with 17.8% of Matrimd polymer, 13.2% of silicone polymer and 15.5 wt% of MIL-53 particle displayed the highest selectivity and CO2 permeability.

  17. Matrix metalloproteinase 2 and membrane type 1 matrix metalloproteinase co-regulate axonal outgrowth of mouse retinal ganglion cells

    DEFF Research Database (Denmark)

    Gaublomme, Djoere; Buyens, Tom; De Groef, Lies

    2014-01-01

    regenerative therapies, an improved understanding of axonal outgrowth and the various molecules influencing it, is highly needed. Matrix metalloproteinases (MMPs) constitute a family of zinc-dependent proteases that were sporadically reported to influence axon outgrowth. Using an ex vivo retinal explant model......, but not MMP-9, are involved in this process. Furthermore, administration of a novel antibody to MT1-MMP that selectively blocks pro-MMP-2 activation revealed a functional co-involvement of these proteinases in determining RGC axon outgrowth. Subsequent immunostainings showed expression of both MMP-2 and MT1...... nervous system is lacking in adult mammals, thereby impeding recovery from injury to the nervous system. Matrix metalloproteinases (MMPs) constitute a family of zinc-dependent proteases that were sporadically reported to influence axon outgrowth. Inhibition of specific MMPs reduced neurite outgrowth from...

  18. Polymer-metal organic frameworks (MOFs) mixed matrix membranes for gas separation applications

    NARCIS (Netherlands)

    Shahid, S.

    2015-01-01

    The performance of polymeric membranes is often limited by a trade-off between membrane permeability and selectivity, the so-called Robeson upper bound. Additionally, in high pressure CO2 capture applications, excessive swelling of the polymer membrane often leads to plasticization resulting in

  19. The influence of soil and landfill leachate microorganisms in the degradation of PVC/PCL films cast from DMF

    Directory of Open Access Journals (Sweden)

    Adriana de Campos

    2012-01-01

    Full Text Available While the use of plastics continues to increase in our daily lives in a growing range products, these materials are very persistent in the environment. The blending of aliphatic polyesters with other thermoplastic polymers is a profitable way of producing materials with changed physical properties and biodegradability, which can facilitate microbial adhesion to the polymer matrix and help to reduce (post-consumer degradation time of these materials in landfills. This study was an investigation of the biodegradation of films of blends of poly(vinyl chloride (PVC and poly(ε-caprolactone (PCL by soil microorganisms and leachate, by means of respirometry, infrared absorption spectroscopy (FTIR, differential calorimetry scanning (DSC, scanning electron microscopy (SEM, contact angle and weight loss. The results showed that in the soil, the films suffered oxidative biodegradation. The PCL promoted degradation of the PVC in the film of PVC/PCL and the PVC inhibited the rapid degradation of the PCL.

  20. Regulation of Membrane-Type 4 Matrix Metalloproteinase by SLUG Contributes to Hypoxia-Mediated Metastasis

    Directory of Open Access Journals (Sweden)

    Chi-Hung Huang

    2009-12-01

    Full Text Available The hypoxic tumor environment has been shown to be critical to cancer metastasis through the promotion of angiogenesis, induction of epithelial-mesenchymal transition (EMT, and acquisition of invasive potential. However, the impact of hypoxia on the expression profile of the proteolytic enzymes involved in invasiveness is relatively unknown. Membrane-type 4 matrix metalloproteinase (MT4-MMP is a glycosyl-phosphatidyl inositol-anchored protease that has been shown to be overexpressed in human cancers. However, detailed mechanisms regarding the regulation and function of MT4-MMP expression in tumor cells remain unknown. Here, we demonstrate that hypoxia or overexpression of hypoxia-inducible factor-1α (HIF-1α induced MT4-MMP expression in human cancer cells. Activation of SLUG, a transcriptional factor regulating the EMT process of human cancers, by HIF-1α was critical for the induction of MT4-MMP under hypoxia. SLUG regulated the transcription of MT4-MMP through direct binding to the E-box located in its proximal promoter. Short-interference RNA-mediated knockdown of MT4-MMP attenuated in vitro invasiveness and in vivo pulmonary colonization of tumor cells without affecting cell migratory ability. MT4-MMP promoted invasiveness and pulmonary colonization through modulation of the expression profile of MMPs and angiogenic factors. Finally, coexpression of HIF-1α and MT4-MMP in human head and neck cancer was predictive of a worse clinical outcome. These findings establish a novel signaling pathway for hypoxia-mediated metastasis and elucidate the underlying regulatory mechanism and functional significance of MT4-MMP in cancer metastasis.

  1. Origins and Evolution of Inorganic-Based and MOF-Based Mixed-Matrix Membranes for Gas Separations

    Directory of Open Access Journals (Sweden)

    Edson V. Perez

    2016-09-01

    Full Text Available Gas separation for industrial, energy, and environmental applications requires low energy consumption and small footprint technology to minimize operating and capital costs for the processing of large volumes of gases. Among the separation methods currently being used, like distillation, amine scrubbing, and pressure and temperature swing adsorption, membrane-based gas separation has the potential to meet these demands. The key component, the membrane, must then be engineered to allow for high gas flux, high selectivity, and chemical and mechanical stability at the operating conditions of feed composition, pressure, and temperature. Among the new type of membranes studied that show promising results are the inorganic-based and the metal-organic framework-based mixed-matrix membranes (MOF-MMMs. A MOF is a unique material that offers the possibility of tuning the porosity of a membrane by introducing diffusional channels and forming a compatible interface with the polymer. This review details the origins of these membranes and their evolution since the first inorganic/polymer and MOF/polymer MMMs were reported in the open literature. The most significant advancements made in terms of materials, properties, and testing conditions are described in a chronological fashion.

  2. The major basement membrane components localize to the chondrocyte pericellular matrix--a cartilage basement membrane equivalent?

    DEFF Research Database (Denmark)

    Kvist, Alexander J.; Nyström, Alexander; Hultenby, Kjell

    2007-01-01

    In this study, we demonstrate that articular cartilage chondrocytes are surrounded by the defining basement membrane proteins laminin, collagen type IV, nidogen and perlecan, and suggest that these form the functional equivalent of a basement membrane. We found by real-time PCR that mouse...... chondrocytes express these four cardinal components of basement membranes and demonstrated by immunohistochemistry that the proteins are present in bovine and mouse cartilage tissues and are deposited in a thin pericellular structure. Immunoelectron microscopy confirmed high laminin concentration...... becomes less distinct, especially in areas of obvious mechanical attrition. Interestingly, individual laminin subunits were located in different zones of the cartilage, with laminin alpha1 showing preferential localization around a select population of superficial layer chondrocytes. We propose...

  3. Separation of carbon dioxide from flue gas by mixed matrix membranes using dual phase microporous polymeric constituents.

    Science.gov (United States)

    Sekizkardes, Ali K; Kusuma, Victor A; Dahe, Ganpat; Roth, Elliot A; Hill, Lawrence J; Marti, Anne; Macala, Megan; Venna, Surendar R; Hopkinson, David

    2016-09-27

    This study presents the fabrication of a new mixed matrix membrane using two microporous polymers: a polymer of intrinsic microporosity PIM-1 and a benzimidazole linked polymer, BILP-101, and their CO 2 separation properties from post-combustion flue gas. 17, 30 and 40 wt% loadings of BILP-101 into PIM-1 were tested, resulting in mechanically stable films showing very good interfacial interaction due to the inherent H-bonding capability of the constituent materials. Gas transport studies showed that BILP-101/PIM-1 membranes exhibit high CO 2 permeability (7200 Barrer) and selectivity over N 2 (15). The selected hybrid membrane was further tested for CO 2 separation using actual flue gas from a coal-fired power plant.

  4. Towards Acid-Tolerated Ethanol Dehydration: Chitosan-Based Mixed Matrix Membranes Containing Cyano-Bridged Coordination Polymer Nanoparticles.

    Science.gov (United States)

    Wu, C-W; Kang, Chao-Hsiang; Lin, Yi-Feng; Tung, Kuo-Lun; Deng, Yu-Heng; Ahamad, Tansir; Alshehri, Saad M; Suzuki, Norihiro; Yamauchi, Yusuke

    2016-04-01

    Prussian blue (PB) nanoparticles, one of many cyano-bridged coordination polymers, are successfully incorporated into chitosan (CS) polymer to prepare PB/CS mixed matrix membranes (MMMs). The PB nanoparticles are uniformly distributed in the MMMs without the collapse of the original PB structure. As-prepared PB/CS MMMs are used for ethanol dehydration at 25 °C in the pervaporation process. The effect of loading PB in CS matrix on pervaporation performance is carefully investigated. The PB/CS membrane with 30 wt% PB loading shows the best performance with a permeate flux of 614 g. m-2 . h-1 and a separation factor of 1472. The pervaporation using our PB/CS membranes exhibits outstanding performance in comparison with the previously reported CS-based membranes and MMMs. Furthermore, the addition of PB allows PB/CS MMMs to be tolerant of acidic environment. The present work demonstrates good pervaporation performance of PB/CS MMMs for the separation of an ethanol/water (90:10 in wt%) solution. Our new system provides an opportunity for dehydration of bioethanol in the future.

  5. Enhanced selectivity in mixed matrix membranes for CO2 capture through efficient dispersion of amine-functionalized MOF nanoparticles

    Science.gov (United States)

    Ghalei, Behnam; Sakurai, Kento; Kinoshita, Yosuke; Wakimoto, Kazuki; Isfahani, Ali Pournaghshband; Song, Qilei; Doitomi, Kazuki; Furukawa, Shuhei; Hirao, Hajime; Kusuda, Hiromu; Kitagawa, Susumu; Sivaniah, Easan

    2017-07-01

    Mixed matrix membranes (MMMs) for gas separation applications have enhanced selectivity when compared with the pure polymer matrix, but are commonly reported with low intrinsic permeability, which has major cost implications for implementation of membrane technologies in large-scale carbon capture projects. High-permeability polymers rarely generate sufficient selectivity for energy-efficient CO2 capture. Here we report substantial selectivity enhancements within high-permeability polymers as a result of the efficient dispersion of amine-functionalized, nanosized metal-organic framework (MOF) additives. The enhancement effects under optimal mixing conditions occur with minimal loss in overall permeability. Nanosizing of the MOF enhances its dispersion within the polymer matrix to minimize non-selective microvoid formation around the particles. Amination of such MOFs increases their interaction with thepolymer matrix, resulting in a measured rigidification and enhanced selectivity of the overall composite. The optimal MOF MMM performance was verified in three different polymer systems, and also over pressure and temperature ranges suitable for carbon capture.

  6. Surface-modified anodic aluminum oxide membrane with hydroxyethyl celluloses as a matrix for bilirubin removal.

    Science.gov (United States)

    Xue, Maoqiang; Ling, Yisheng; Wu, Guisen; Liu, Xin; Ge, Dongtao; Shi, Wei

    2013-01-01

    Microporous anodic aluminum oxide (AAO) membranes were modified by 3-glycidoxypropyltrimethoxysilane to produce terminal epoxy groups. These were used to covalently link hydroxyethyl celluloses (HEC) to amplify reactive groups of AAO membrane. The hydroxyl groups of HEC-AAO composite membrane were further modified with 1,4-butanediol diglycidyl ether to link arginine as an affinity ligand. The contents of HEC and arginine of arginine-immobilized HEC-AAO membrane were 52.1 and 19.7mg/g membrane, respectively. As biomedical adsorbents, the arginine-immobilized HEC-AAO membranes were tested for bilirubin removal. The non-specific bilirubin adsorption on the unmodified HEC-AAO composite membranes was 0.8mg/g membrane. Higher bilirubin adsorption values, up to 52.6mg/g membrane, were obtained with the arginine-immobilized HEC-AAO membranes. Elution of bilirubin showed desorption ratio was up to 85% using 0.3M NaSCN solution as the desorption agent. Comparisons equilibrium and dynamic capacities showed that dynamic capacities were lower than the equilibrium capacities. In addition, the adsorption mechanism of bilirubin and the effects of temperature, initial concentration of bilirubin, albumin concentration and ionic strength on adsorption were also investigated. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Age-related collagen turnover of the interstitial matrix and basement membrane: Implications of age- and sex-dependent remodeling of the extracellular matrix.

    Science.gov (United States)

    Kehlet, Stephanie N; Willumsen, Nicholas; Armbrecht, Gabriele; Dietzel, Roswitha; Brix, Susanne; Henriksen, Kim; Karsdal, Morten A

    2018-01-01

    The extracellular matrix (ECM) plays a vital role in maintaining normal tissue function. Collagens are major components of the ECM and there is a tight equilibrium between degradation and formation of these proteins ensuring tissue health and homeostasis. As a consequence of tissue turnover, small collagen fragments are released into the circulation, which act as important biomarkers in the study of certain tissue-related remodeling factors in health and disease. The aim of this study was to establish an age-related collagen turnover profile of the main collagens of the interstitial matrix (type I and III collagen) and basement membrane (type IV collagen) in healthy men and women. By using well-characterized competitive ELISA-assays, we assessed specific fragments of degraded (C1M, C3M, C4M) and formed (PINP, Pro-C3, P4NP7S) type I, III and IV collagen in serum from 617 healthy men and women ranging in ages from 22 to 86. Subjects were divided into 5-year age groups according to their sex and age. Groups were compared using Kruskal-Wallis adjusted for Dunn's multiple comparisons test and Mann-Whitney t-test. Age-specific changes in collagen turnover was most profound for type I collagen. PINP levels decreased in men with advancing age, whereas in women, the level decreased in early adulthood followed by an increase around the age of menopause (age 40-60). Sex-specific changes in type I, III and IV collagen turnover was present at the age around menopause (age 40-60) with women having an increased turnover. In summary, collagen turnover is affected by age and sex with the interstitial matrix and the basement membrane being differently regulated. The observed changes needs to be accounted for when measuring ECM related biomarkers in clinical studies.

  8. Permeability and Selectivity of PPO/Graphene Composites as Mixed Matrix Membranes for CO2 Capture and Gas Separation

    Directory of Open Access Journals (Sweden)

    Riccardo Rea

    2018-01-01

    Full Text Available We fabricated novel composite (mixed matrix membranes based on a permeable glassy polymer, Poly(2,6-dimethyl-1,4-phenylene oxide (PPO, and variable loadings of few-layer graphene, to test their potential in gas separation and CO2 capture applications. The permeability, selectivity and diffusivity of different gases as a function of graphene loading, from 0.3 to 15 wt %, was measured at 35 and 65 °C. Samples with small loadings of graphene show a higher permeability and He/CO2 selectivity than pure PPO, due to a favorable effect of the nanofillers on the polymer morphology. Higher amounts of graphene lower the permeability of the polymer, due to the prevailing effect of increased tortuosity of the gas molecules in the membrane. Graphene also allows dramatically reducing the increase of permeability with temperature, acting as a “stabilizer” for the polymer matrix. Such effect reduces the temperature-induced loss of size-selectivity for He/N2 and CO2/N2, and enhances the temperature-induced increase of selectivity for He/CO2. The study confirms that, as observed in the case of other graphene-based mixed matrix glassy membranes, the optimal concentration of graphene in the polymer is below 1 wt %. Below such threshold, the morphology of the nanoscopic filler added in solution affects positively the glassy chains packing, enhancing permeability and selectivity, and improving the selectivity of the membrane at increasing temperatures. These results suggest that small additions of graphene to polymers can enhance their permselectivity and stabilize their properties.

  9. Substrate Effect on Carbon/Ceramic Mixed Matrix Membrane Prepared by a Vacuum-Assisted Method for Desalination

    Directory of Open Access Journals (Sweden)

    Yingjun Song

    2018-05-01

    Full Text Available This work investigates the effect of various membrane substrates and coating conditions on the formation of carbon/ceramic mixed matrix membranes for desalination application. The substrates were impregnated with phenolic resin via a vacuum-assisted method followed by carbonization under an inert gas. Substrates with pore sizes of 100 nm required a single impregnation step only, where short vacuum times (<120 s resulted in low quality membranes with defects. For vacuum times of ≥120 s, high quality membranes with homogeneous impregnation were prepared leading to high salt rejection (>90% and high water fluxes (up to 25 L m−2 h−1. The increase in water flux as a function of the vacuum time confirms the vacuum etching effect resulting from the vacuum-assisted method. Substrates with pore sizes of 140 nm required two impregnation steps. These pores were too large for the ceramic inter-particle space to be filled with phenolic resin via a single step. In the second impregnation step, increasing the concentration of the phenolic resin resulted in membranes with lower water fluxes. These results indicate that thicker films were formed by increasing the phenolic resin concentration. In the case of substrates with pores of 600 nm, these pores were too large and inter-particle space filling with phenolic resin was not attained.

  10. Electron beam crosslinked PVC : structure property relationships

    International Nuclear Information System (INIS)

    Gupta, Neeraj K.; Sabharwal, Sunil

    2001-01-01

    PVC is used extensively for its insulating properties for the manufacture of wires and cables and for other applications. Its gradual degradation, oxidation and even dehydro chlorination restricts use for long lasting period in installations such as high temperature zones, underground cables, communication systems, electro-nuclear facilities, etc. The technological properties and performance characteristics of PVC based insulation can be improved via crosslinking by high-energy electrons. PVC is however a polymer, which on irradiation predominantly undergoes degradation. To avoid degradation, it needs to be compounded with sensitizing agents or multifunctional monomers so that crosslinking is the predominant reaction. Radiation cross linkable formulations are complex mixtures of resin and various additives incorporated for achieving desired technological and performance characteristics, ease of processing and improving quality. The proper choice of additives and sensitizing agents enable low dose requirements for efficient crosslinking and improvements in various technological properties. The purposes of this work was to investigate the effect of using a binary sensitizer blend of a trifunctional monomer and a rubber in PVC, and develop suitable electron beam cross linkable formulations for wire insulation. This paper presents some aspects of the investigations and development of insulation demonstrated at industrial scale

  11. PVC posting bags for glove boxes

    International Nuclear Information System (INIS)

    1976-12-01

    This specification covers the materials, measurements and manufacture of unpigmented PVC posting bags for use on glove boxes, together with methods of testing the materials. These bags are used in the handling of radioactive and toxic materials of a hazardous nature and therefore must be of the highest standard of mechanical strength, leak tightness and general finish. (author)

  12. Estimation of life of PVC cables

    International Nuclear Information System (INIS)

    Bora, J.S.; Babar, A.K.

    1989-01-01

    Life-spans at various extrapolated temperatures corresponding to early, mid and late-stage failures of PVC are quite consistent and is about 32 years at 30degC. For every 10degC rise in ambient temperature life becomes less than half. (author). 2 tabs

  13. Polarizing PVC — A Discrepant Event

    Science.gov (United States)

    Headly, David; Karabatek, Mohamed

    2016-01-01

    Each year when teaching polarization phenomena and the Triboelectric Series in a unit on electrostatics, I would balance some rods (2-3 ft in length) made from wood, aluminum, PVC, and Plexiglas on an inverted watch glass and demonstrate to the class how a party balloon rubbed with fake rabbit fur (charging the balloon negative) would always attract the uncharged rods, causing them to rotate towards the balloon (see Fig. 1). The fact that a charged object always attracts a neutral object due to the induced dipole in the latter is a great way to test if something is in fact charged. Surprisingly, the PVC pipe would usually, but not always, repel the charged balloon and rotate away! Repulsion means that neither of the objects are electrically neutral. In a separate test, after rubbing together a Plexiglas rod with a polyethylene grocery bag (making the rod positively charged and the bag negatively charged), the PVC usually attracts the rod. With the help of a student as part of his senior project, I finally decided to investigate further the source of the negative charge that exists on PVC. Specifically, is it nothing more than static charge that builds up on the pipe from unavoidable contact with its surroundings, or is it somehow intrinsic to the manufacturing process?

  14. Properties of lightweight aggregate concrete prepared with PVC granules derived from scraped PVC pipes.

    Science.gov (United States)

    Kou, S C; Lee, G; Poon, C S; Lai, W L

    2009-02-01

    This paper aims to investigate the fresh and hardened properties of lightweight aggregate concretes that are prepared with the use of recycled plastic waste sourced from scraped PVC pipes to replace river sand as fine aggregates. A number of laboratory prepared concrete mixes were tested, in which river sand was partially replaced by PVC plastic waste granules in percentages of 0%, 5%, 15%, 30% and 45% by volume. Two major findings are identified. The positive side shows that the concrete prepared with a partial replacement by PVC was lighter (lower density), was more ductile (greater Poisson's ratios and reduced modulus of elasticity), and had lower drying shrinkage and higher resistance to chloride ion penetration. The negative side reveals that the workability, compressive strength and tensile splitting strength of the concretes were reduced. The results gathered would form a part of useful information for recycling PVC plastic waste in lightweight concrete mixes.

  15. Application of 1-ethyl-3-(2,5-dihydro-4-(3,5-dimethyl-1H-pyrazol-4-yl) -5-oxo-1H-pyrazol-3-yl)thiourea as sensing material for construction of Tm3+-PVC membrane sensor

    International Nuclear Information System (INIS)

    Zamani, Hassan Ali; Feizyzadeh, Babak; Faridbod, Farnoush; Ganjali, Mohammad Reza

    2011-01-01

    A thulium(III) membrane sensor was made using 2% sodium tetraphenyl borate (NaTPB), 65% dibutylphthalate (DBP), 30% poly(vinyl chloride) (PVC) and 3% 1-ethyl-3-(2,5-dihydro-4-(3,5-dimethyl-1H-pyrazol-4-yl) -5-oxo-1H-pyrazol-3-yl)thiourea (ET) as an ionophore. Conductometric study shows selectivity of the Et toward Tm 3+ ions. Nernstian response of 19.6 ± 0.4 mV per decade of thulium concentration was observed, and the electrode worked well in concentration range of 1.0 x 10 -6 to 1.0 x 10 -2 mol L -1 with a lower detection limit (LDL) of 7.2 x 10 -7 mol L -1 , in a pH range of 4.3-10.4. The selectivity of the sensor over alkaline, alkaline earth, transition and heavy metal ions was also found to be in a satisfactory range. To check the analytical applicability of the proposed Tm 3+ sensor, it was successfully used as an indicator electrode in analysis of thulium in certified reference materials. - Research highlights: → This work reports development of polymeric membrane sensor for Tm3+ determination in certified reference materials. → The novelty of this work is based on the high affinity of the ionophore toward the Tm3+ ions which causes the high selectivity of the sensor. → The newly developed sensor is superior to the formerly reported Tm3+ sensors in terms of selectivity and detection limit.

  16. Application of 1-ethyl-3-(2,5-dihydro-4-(3,5-dimethyl-1H-pyrazol-4-yl) -5-oxo-1H-pyrazol-3-yl)thiourea as sensing material for construction of Tm{sup 3+}-PVC membrane sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Feizyzadeh, Babak [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Faridbod, Farnoush; Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of)

    2011-10-10

    A thulium(III) membrane sensor was made using 2% sodium tetraphenyl borate (NaTPB), 65% dibutylphthalate (DBP), 30% poly(vinyl chloride) (PVC) and 3% 1-ethyl-3-(2,5-dihydro-4-(3,5-dimethyl-1H-pyrazol-4-yl) -5-oxo-1H-pyrazol-3-yl)thiourea (ET) as an ionophore. Conductometric study shows selectivity of the Et toward Tm{sup 3+} ions. Nernstian response of 19.6 {+-} 0.4 mV per decade of thulium concentration was observed, and the electrode worked well in concentration range of 1.0 x 10{sup -6} to 1.0 x 10{sup -2} mol L{sup -1} with a lower detection limit (LDL) of 7.2 x 10{sup -7} mol L{sup -1}, in a pH range of 4.3-10.4. The selectivity of the sensor over alkaline, alkaline earth, transition and heavy metal ions was also found to be in a satisfactory range. To check the analytical applicability of the proposed Tm{sup 3+} sensor, it was successfully used as an indicator electrode in analysis of thulium in certified reference materials. - Research highlights: {yields} This work reports development of polymeric membrane sensor for Tm3+ determination in certified reference materials. {yields} The novelty of this work is based on the high affinity of the ionophore toward the Tm3+ ions which causes the high selectivity of the sensor. {yields} The newly developed sensor is superior to the formerly reported Tm3+ sensors in terms of selectivity and detection limit.

  17. Metal Organic Framework Crystals in Mixed-Matrix Membranes: Impact of the Filler Morphology on the Gas Separation Performance.

    Science.gov (United States)

    Sabetghadam, Anahid; Seoane, Beatriz; Keskin, Damla; Duim, Nicole; Rodenas, Tania; Shahid, Salman; Sorribas, Sara; Le Guillouzer, Clément; Clet, Guillaume; Tellez, Carlos; Daturi, Marco; Coronas, Joaquin; Kapteijn, Freek; Gascon, Jorge

    2016-05-10

    Mixed-matrix membranes (MMMs) comprising NH 2 -MIL-53(Al) and Matrimid ® or 6FDA-DAM have been investigated. The MOF loading has been varied between 5 and 20 wt%, while NH 2 -MIL-53(Al) with three different morphologies: nanoparticles, nanorods and microneedles have been dispersed in Matrimid ® . The synthesized membranes have been tested in the separation of CO 2 from CH 4 in an equimolar mixture. At 3 bar and 298 K for 8 wt% MOF loading, incorporation of NH 2 -MIL-53(Al) nanoparticles leads to the largest improvement compared to nanorods and microneedles. The incorporation of the best performing filler, i.e. NH 2 -MIL-53(Al) nanoparticles, to the highly permeable 6FDA-DAM has a larger effect, and the CO 2 permeability increased up to 85 % with slightly lower selectivities for 20 wt% MOF loading. Specifically, these membranes have a permeability of 660 Barrer with CO 2 /CH 4 separation factor of 28, leading to a performance very close to the Robeson limit of 2008. Furthermore, a new non-destructive technique based on Raman spectroscopy mapping is introduced to assess the homogeneity of the filler dispersion in the polymer matrix. The MOF contribution can be calculated by modelling the spectra. The determined homogeneity of the MOF filler distribution in the polymer is confirmed by FIB-SEM analysis.

  18. STRUCTURAL CHARACTERIZATION AND GAS PERMEATION PROPERTIES OF POLYETHERIMIDE (PEI/ZEOLITIC IMIDAZOLATE (ZIF-11 MIXED MATRIX MEMBRANES

    Directory of Open Access Journals (Sweden)

    Mehtap Şafak Boroğlu

    2016-06-01

    Full Text Available In this study, the preparation of polyetherimide (PEI-Ultem1000/ZIF-11 mixed matrix membranes was studied in various ZIF-11 nanoparticles loadings (0, 10, 15, 20, and 30 wt.%. The newly synthesized ZIF-11 nanoparticles with an average particle size of ~280 nm were integrated in PEI membranes as novel mixed matrix membranes (MMMs. The effect of ZIF-11 loading was scrutinised for H2, CO2, and CH4 gas separation performance at 35 °C and 4 bar. The incorporation of ZIF-11 nanoparticles improved the gas permeation properties of the MMMs with an increase in ZIF-11 loading. As the ZIF-11 loading increased up to 20 wt.%, the permeability of H2 and CO2 increased to four times higher than that of the pure polymer. Moderate increase of CH4 permeability was also recorded. At higher loadings above 20 wt.%, the permeability decreased for all gases and the CO2/CH4, and H2/CH4 selectivities increased consistent with the ZIF-11 loading.

  19. Effect of polymer type on characterization and filtration performances of multi-walled carbon nanotubes (MWCNT)-COOH-based polymeric mixed matrix membranes.

    Science.gov (United States)

    Sengur-Tasdemir, Reyhan; Mokkapati, Venkata R S S; Koseoglu-Imer, Derya Y; Koyuncu, Ismail

    2018-05-01

    Multi-walled carbon nanotubes (MWCNTs) can be used for the fabrication of mixed matrix polymeric membranes that can enhance filtration perfomances of the membranes by modifying membrane surface properties. In this study, detailed characterization and filtration performances of MWCNTs functionalized with COOH group, blended into polymeric flat-sheet membranes were investigated using different polymer types. Morphological characterization was carried out using atomic force microscopy, scanning electron microscopy and contact angle measurements. For filtration performance tests, protein, dextran, E. coli suspension, Xanthan Gum and real activated sludge solutions were used. Experimental data and analyses revealed that Polyethersulfone (PES) + MWCNT-COOH mixed matrix membranes have superior performance abilities compared to other tested membranes.

  20. HYDROPHOBIC ZEOLITE-SILICONE RUBBER MIXED MATRIX MEMBRANES FOR ETHANOL-WATER SEPARATION: EFFECT OF ZEOLITE AND SILICONE COMPONENT SELECTION ON PERVAPORATION PERFORMANCE

    Science.gov (United States)

    High-silica ZSM 5 zeolites were incorporated into poly(dimethyl siloxane) (PDMS) polymers to form mixed matrix membranes for ethanol removal from water via pervaporation. Membrane formulation and preparation parameters were varied to determine the effect on pervaporation perform...

  1. Integrating seawater desalination and wastewater reclamation forward osmosis process using thin-film composite mixed matrix membrane with functionalized carbon nanotube blended polyethersulfone support layer.

    Science.gov (United States)

    Choi, Hyeon-Gyu; Son, Moon; Choi, Heechul

    2017-10-01

    Thin-film composite mixed matrix membrane (TFC MMM) with functionalized carbon nanotube (fCNT) blended in polyethersulfone (PES) support layer was synthesized via interfacial polymerization and phase inversion. This membrane was firstly tested in lab-scale integrating seawater desalination and wastewater reclamation forward osmosis (FO) process. Water flux of TFC MMM was increased by 72% compared to that of TFC membrane due to enhanced hydrophilicity. Although TFC MMM showed lower water flux than TFC commercial membrane, enhanced reverse salt flux selectivity (RSFS) of TFC MMM was observed compared to TFC membrane (15% higher) and TFC commercial membrane (4% higher), representing membrane permselectivity. Under effluent organic matter (EfOM) fouling test, 16% less normalized flux decline of TFC MMM was observed compared to TFC membrane. There was 8% less decline of TFC MMM compared to TFC commercial membrane due to fCNT effect on repulsive foulant-membrane interaction enhancement, caused by negatively charged membrane surface. After 10 min physical cleaning, TFC MMM displayed higher recovered normalized flux than TFC membrane (6%) and TFC commercial membrane (4%); this was also supported by visualized characterization of fouling layer. This study presents application of TFC MMM to integrated seawater desalination and wastewater reclamation FO process for the first time. It can be concluded that EfOM fouling of TFC MMM was suppressed due to repulsive foulant-membrane interaction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Protein translocation channel of mitochondrial inner membrane and matrix-exposed import motor communicate via two-domain coupling protein.

    Science.gov (United States)

    Banerjee, Rupa; Gladkova, Christina; Mapa, Koyeli; Witte, Gregor; Mokranjac, Dejana

    2015-12-29

    The majority of mitochondrial proteins are targeted to mitochondria by N-terminal presequences and use the TIM23 complex for their translocation across the mitochondrial inner membrane. During import, translocation through the channel in the inner membrane is coupled to the ATP-dependent action of an Hsp70-based import motor at the matrix face. How these two processes are coordinated remained unclear. We show here that the two domain structure of Tim44 plays a central role in this process. The N-terminal domain of Tim44 interacts with the components of the import motor, whereas its C-terminal domain interacts with the translocation channel and is in contact with translocating proteins. Our data suggest that the translocation channel and the import motor of the TIM23 complex communicate through rearrangements of the two domains of Tim44 that are stimulated by translocating proteins.

  3. Viability of chondrocytes seeded onto a collagen I/III membrane for matrix-induced autologous chondrocyte implantation.

    Science.gov (United States)

    Hindle, Paul; Hall, Andrew C; Biant, Leela C

    2014-11-01

    Cell viability is crucial for effective cell-based cartilage repair. The aim of this study was to determine the effect of handling the membrane during matrix-induced autologous chondrocyte implantation surgery on the viability of implanted chondrocytes. Images were acquired under five conditions: (i) Pre-operative; (ii) Handled during surgery; (iii) Cut edge; (iv) Thumb pressure applied; (v) Heavily grasped with forceps. Live and dead cell stains were used. Images were obtained for cell counting and morphology. Mean cell density was 6.60 × 10(5) cells/cm(2) (5.74-7.11 × 10(5) ) in specimens that did not have significant trauma decreasing significantly in specimens that had been grasped with forceps (p < 0.001) or cut (p = 0.004). Cell viability on delivery grade membrane was 75.1%(72.4-77.8%). This dropped to 67.4%(64.1-69.7%) after handling (p = 0.002), 56.3%(51.5-61.6%) after being thumbed (p < 0.001) and 28.8%(24.7-31.2%) after crushing with forceps (p < 0.001). When cut with scissors there was a band of cell death approximately 275 µm in width where cell viability decreased to 13.7%(10.2-18.2%, p < 0.001). Higher magnification revealed cells without the typical rounded appearance of chondrocytes. We found that confocal laser-scanning microscope (CLSM) can be used to quantify and image the fine morphology of cells on a matrix-induced autologous chondrocyte implantation (MACI) membrane. Careful handling of the membrane is essential to minimise chondrocyte death during surgery. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  4. Thermo-mechanical properties of mixed-matrix membranes encompassing zeolitic imidazolate framework-90 and polyvinylidine difluoride: ZIF-90/PVDF nanocomposites

    Science.gov (United States)

    Flyagina, Irina S.; Mahdi, E. M.; Titov, Kirill; Tan, Jin-Chong

    2017-08-01

    Mixed-matrix membranes are contemporary nanocomposite materials with many potential applications, from liquid and gas separations to chemical sensors and biomedicine. We report fabrication of a metal-organic framework (MOF)-based nanocomposite, combining polyvinylidene difluoride (PVDF) polymer as the matrix and ZIF-90 nanocrystals of up to 30 wt. % filler content. The focus is to establish the processing—microstructure—mechanical property relationships. We reveal the importance for quantifying salient effects of the filler contents: (i) tensile strength degrades beyond 10 wt. % and (ii) mechanical toughness declines due to membrane embrittlement. These are vital mechanical aspects but widely overlooked in the emergent field of MOF membranes and composites.

  5. Graphene immobilized enzyme/polyethersulfone mixed matrix membrane: Enhanced antibacterial, permeable and mechanical properties

    International Nuclear Information System (INIS)

    Duan, Linlin; Wang, Yuanming; Zhang, Yatao; Liu, Jindun

    2015-01-01

    Graphical abstract: - Highlights: • Lysozyme was immobilized on the surface of graphene oxide (GO) and reduced GO (RGO). • The novel hybrid membranes based on lysozyme and graphene were fabricated firstly. • These membranes showed good antibacterial and mechanical performance. - Abstract: Enzyme immobilization has been developed to address lots of issues of free enzyme, such as instability, low activity and difficult to retain. In this study, graphene was used as an ideal carrier for lysozyme immobilization, including graphene oxide (GO) immobilized lysozyme (GO-Ly) and chemically reduced graphene oxide (CRGO) immobilized lysozyme (CRGO-Ly). Herein, lysozyme as a bio-antibacterial agent has excellent antibacterial performance and the products of its catalysis are safety and nontoxic. Then the immobilized lysozyme materials were blended into polyethersulfone (PES) casting solution to prepare PES ultrafiltration membrane via phase inversion method. GO and CRGO were characterized by Fourier transform infrared spectroscopy (FTIR), Ultraviolet–visible spectrum (UV), X-ray diffraction (XRD), and transmission electron microscopy (TEM) and the immobilized lysozyme composites were observed by fluorescent microscopy. The results revealed that GO and CRGO were successfully synthesized and lysozyme was immobilized on their surfaces. The morphology, hydrophilicity, mechanical properties, separation properties and antibacterial activity of the hybrid membranes were characterized in detail. The hydrophilicity, water flux and mechanical strength of the hybrid membranes were significantly enhanced after adding the immobilized lysozyme. In the antibacterial experiment, the hybrid membranes exhibited an effective antibacterial performance against Escherichia coli (E. coli).

  6. Evaluation of dosimetric characteristics of graphene oxide/PVC nanocomposite for gamma radiation applications

    Energy Technology Data Exchange (ETDEWEB)

    Feizi, Shahzad; Malekie, Shahryar; Ziaie, Farhood [Nuclear Science and Technology Research Institute (NSTRI), Karaj (Iran, Islamic Republic of). Radiation Application Research School; Rahighi, Reza; Tayyebi, Ahmad [Univ. of Technology, Tehran (Iran, Islamic Republic of). Dept. of Physics

    2017-04-01

    Graphene oxide-polyvinyl chloride composite was prepared using tetrahydrofuran solvent-assisted dispersion of characterized nano flakes of graphene oxide in polymer matrix. Electrical percolation threshold of GO/PVC nanocomposite was determined via a finite element simulation method with a 2D model and compared with experimental results. A conductive cell with two silver coated walls was designed and fabricated for exploring dosimetric properties of the composite. Some characteristics of the new nanocomposite such as linearity of dose response, repeatability, sensitivity and angular dependence are investigated. According to 2D proposed method, obtained data associated to electrical conductivity of the GO/polymer composite for PVC matrix plotted in different GO weight percentages and had good compatibility (validity) with experimental data. The dose response is linear in the 17-51 mGy dose range and it can be introduced for gamma radiation dosimetry in diagnostic activities.

  7. Radiation effect on PVC/ENR blends

    International Nuclear Information System (INIS)

    Chantara Thevy Ratnam; Khairul Zaman Mohd Dahlan

    1997-01-01

    The effect of irradiation on the physical properties of Polyvinyl Chloride / Epoxidised Natural Rubber Blends (PVC/ENR blends) were investigated. The enhancement in tensile strength, elongation at break, hardness and aging properties of the blends have confirmed the positive effect of irradiation on the blends. It is evident from gel fraction and infra red spectroscopic studies that the blends of PVC and ENR cross-linked upon irradiation. The results also revealed that at any blend composition, the enhancement in properties depend on irradiation dose which controls the degree of radiation induced cross-linking. In an attempt to maximize the constructive effect of irradiation, the influence of various additives such as stabilizers, radiation sensitizers, fillers and processing aids on the blend properties were studied. The changes in blend properties upon irradiation with the presents of above additives were also presented in this paper

  8. The viability of PVC/Al blister reuse and PVC property studies after ionizing radiation processing

    International Nuclear Information System (INIS)

    Castro, Alex Terela Pinheiro de

    2008-01-01

    The objective of this research was to separate, by means of a process of dissolution, the PVC and the aluminum that compose blister packs, generally used for pharmaceutical pills. We also studied the effect of the ionizing radiation on the PVC, and, finally, the mechanical recycling of the separated PVC, by a process of extrusion. The material we used in this work is the surplus of the pharmaceutical industry, i.e., packs with defects or burrs. We ground the material to facilitate the handling and the homogenization of the system. After that, we chose two bases for the dissolution of the aluminum: the sodium hydroxide and the potassium hydroxide. We used a system with two concentrations (1 and 2M) for each base, and for every solution we had also an agitated and a non-agitated process. From this method resulted eight experiments. After the dissolution, the samples of the material were submitted to ionizing radiation with doses of 50, 100, 150 and 200 kGy in the Dynamitron II electron accelerator of the CTR-IPEN/CNEN-SP. In the following, these samples were submitted to traction resistance tests to analyze which modifications the irradiation caused. The last step of the research was the recycling of the PVC separated from the Aluminum. We made the recycling in industrial equipment, a PVC tube extruder. The material was combined with lubricants, heat stabilizers and pigment in an intensive mixer and processed into the form of rigid PVC electrical conduits. After the eight experiments, the system with potassium hydroxide base, concentration of 2M and agitation presented the best relation between time of dissolution and characteristics of the resulting material, without degradation of the PVC. In the irradiated samples, the color of the material changed as well as its extension that was as larger as the dose of irradiation they received, indicating the dissociation of the PVC molecules. The extrusion of the PVC was successfully realized: about 200 kg (440 pounds) of

  9. On the direct synthesis of Cu(BDC) MOF nanosheets and their performance in mixed matrix membranes

    Energy Technology Data Exchange (ETDEWEB)

    Shete, Meera; Kumar, Prashant; Bachman, Jonathan E.; Ma, Xiaoli; Smith, Zachary P.; Xu, Wenqian; Mkhoyan, K. Andre; Long, Jeffrey R.; Tsapatsis, Michael

    2018-03-01

    High aspect-ratio nanosheets of metal-organic frameworks (MOFs) hold promise for use as selective flakes in gas separation membranes. However, simple and scalable methods for the synthesis of MOF nanosheets have thus far remained elusive. Here, we describe the direct synthesis of Cu(BDC) (BDC2-= 1,4-benzenedicarboxylate) nanosheets with an average lateral size of 2.5 mu m and a thickness of 25 nm from a well-mixed solution. Characterization of the nanosheets by powder and thin film X-ray diffraction, electron microscopy, and electron diffraction reveals pronounced structural disorder that may affect their pore structure. Incorporation of the Cu (BDC) nanosheets into a Matrimid polymer matrix results in mixed matrix membranes (MMMs) that exhibit a 70% increase in the CO2/CH4 selectivity compared with that of Matrimid. Analysis of new and previously reported permeation data for Cu(BDC) MMMs using a mathematical model for selective flake composites indicates that further performance improvements could be achieved with the selection of different polymers for use in the continuous phase.

  10. Crosslinkable mixed matrix membranes with surface modified molecular sieves for natural gas purification: II. Performance characterization under contaminated feed conditions

    KAUST Repository

    Ward, Jason K.

    2011-07-01

    Mixed matrix membranes (MMMs) composed of the crosslinkable polyimide PDMC and surface modified (SM) SSZ-13 have recently been shown to enhance carbon dioxide permeability and carbon dioxide/methane selectivity versus neat PDMC films by as much as 47% and 13%, respectively (Part I). The previous film characterization, however, was performed using ideal, clean mixed gas feeds. In this paper, PDMC/SSZ-13 MMMs are further characterized using more realistic mixed gases containing low concentrations (500 or 1000. ppm) of toluene as a model contaminant. Mixed matrix membranes are shown to outperform pure PDMC films in the presence of toluene with 43% greater carbon dioxide permeability and 12% greater carbon dioxide/selectivity at 35 °C and 700 psia feed pressure. These results suggest that MMMs-in addition to exhibiting enhanced transport properties-may mitigate performance degradation due to antiplasticization effects. Moreover, the analyses presented here show that the reduction in separation performance by trace contaminant-accelerated physical aging can be suppressed greatly with MMMs. © 2011 Elsevier B.V.

  11. A membrane-bound matrix-metalloproteinase from Nicotiana tabacum cv. BY-2 is induced by bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Wahner Verena

    2009-06-01

    Full Text Available Abstract Background Plant matrix metalloproteinases (MMP are conserved proteolytic enzymes found in a wide range of monocotyledonous and dicotyledonous plant species. Acting on the plant extracellular matrix, they play crucial roles in many aspects of plant physiology including growth, development and the response to stresses such as pathogen attack. Results We have identified the first tobacco MMP, designated NtMMP1, and have isolated the corresponding cDNA sequence from the tobacco suspension cell line BY-2. The overall domain structure of NtMMP1 is similar to known MMP sequences, although certain features suggest it may be constitutively active rather than dependent on proteolytic processing. The protein appears to be expressed in two forms with different molecular masses, both of which are enzymatically active as determined by casein zymography. Exchanging the catalytic domain of NtMMP1 with green fluorescent protein (GFP facilitated subcellular localization by confocal laser scanning microscopy, showing the protein is normally inserted into the plasma membrane. The NtMMP1 gene is expressed constitutively at a low level but can be induced by exposure to bacterial pathogens. Conclusion Our biochemical analysis of NtMMP1 together with bioinformatic data on the primary sequence indicate that NtMMP1 is a constitutively-active protease. Given its induction in response to bacterial pathogens and its localization in the plasma membrane, we propose a role in pathogen defense at the cell periphery.

  12. Growth and morphogenesis of embryonic mouse organs on non-coated and extracellular matrix-coated Biopore membrane

    Science.gov (United States)

    Hardman, P.; Klement, B. J.; Spooner, B. S.

    1993-01-01

    Embryonic mouse salivary glands, pancreata, and kidneys were isolated from embryos of appropriate gestational age by microdissection, and were cultured on Biopore membrane either non-coated or coated with type I collagen or Matrigel. As expected, use of Biopore membrane allowed high quality photomicroscopy of the living organs. In all organs extensive mesenchymal spreading was observed in the presence of type I collagen or Matrigel. However, differences were noted in the effects of extracellular matrix (ECM) coatings on epithelial growth and morphogenesis: salivary glands were minimally affected, pancreas morphogenesis was adversely affected, and kidney growth and branching apparently was enhanced. It is suggested that these differences in behaviour reflect differences in the strength of interactions between the mesenchymal cells and their surrounding endogenous matrix, compared to the exogenous ECM macromolecules. This method will be useful for culture of these and other embryonic organs. In particular, culture of kidney rudiments on ECM-coated Biopore offers a great improvement over previously used methods which do not allow morphogenesis to be followed in vitro.

  13. Mixed matrix membranes for process intensification in electrodialysis of amino acids

    NARCIS (Netherlands)

    Kattan Readi, O.M.; Rolevink, Hendrikus H.M.; Nijmeijer, Dorothea C.

    2014-01-01

    BACKGROUND Amino acids are valuable intermediates in the biobased economy for the production of chemicals. Electro-membrane processes combined with enzymatic modification have been investigated as an alternative technology for the fractionation of a mixture of amino acids with almost identical

  14. New low-flux mixed matrix membranes that offer superior removal of protein-bound toxins from human plasma

    Science.gov (United States)

    Pavlenko, Denys; van Geffen, Esmée; van Steenbergen, Mies J.; Glorieux, Griet; Vanholder, Raymond; Gerritsen, Karin G. F.; Stamatialis, Dimitrios

    2016-10-01

    Hemodialysis is a widely available and well-established treatment for patients with End Stage Renal Disease (ESRD). However, although life-sustaining, patient mortality rates are very high. Several recent studies corroborated the link between dialysis patients’ outcomes and elevated levels of protein-bound uremic toxins (PBUT) that are poorly removed by conventional hemodialysis. Therefore, new treatments are needed to improve their removal. Recently, our group showed that the combination of dialysis and adsorption on one membrane, the mixed matrix membrane (MMM), can effectively remove those toxins from human plasma. However, these first MMMs were rather large in diameter and their mass transport characteristics needed improvement before application in the clinical setting. Therefore, in this study we developed a new generation of MMMs that have a smaller diameter and optimized characteristics offering superior ability in removing the PBUT indoxyl sulfate (IS) and p-cresyl sulfate (pCS) in comparison to first generation MMMs (30 and 125% respectively), as well as, a commercial dialysis membrane (more than 100% better removal).

  15. Characterizing fluorescent dissolved organic matter in a membrane bioreactor via excitation-emission matrix combined with parallel factor analysis.

    Science.gov (United States)

    Maqbool, Tahir; Quang, Viet Ly; Cho, Jinwoo; Hur, Jin

    2016-06-01

    In this study, we successfully tracked the dynamic changes in different constitutes of bound extracellular polymeric substances (bEPS), soluble microbial products (SMP), and permeate during the operation of bench scale membrane bioreactors (MBRs) via fluorescence excitation-emission matrix (EEM) combined with parallel factor analysis (PARAFAC). Three fluorescent groups were identified, including two protein-like (tryptophan-like C1 and tyrosine-like C2) and one microbial humic-like components (C3). In bEPS, protein-like components were consistently more dominant than C3 during the MBR operation, while their relative abundance in SMP depended on aeration intensities. C1 of bEPS exhibited a linear correlation (R(2)=0.738; pbEPS amounts in sludge, and C2 was closely related to the stability of sludge. The protein-like components were more greatly responsible for membrane fouling. Our study suggests that EEM-PARAFAC can be a promising monitoring tool to provide further insight into process evaluation and membrane fouling during MBR operation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Desenvolvimento de PVC reforçado com fibras de vidro longas para fabricação de produtos moldados Long glass fiber reinforcement of PVC molding compounds

    Directory of Open Access Journals (Sweden)

    Leandro H. Grizzo

    2011-01-01

    Full Text Available Neste trabalho foi desenvolvido um método para reforçar PVC rígido com fibras de vidro longas através da incorporação pelo processo de recobrimento da fibra contínua com um composto de PVC plastificado. Posteriormente o filamento foi picotado para a formação de grânulos, com fibras de vidro já incorporadas, que foram misturados mecanicamente ao PVC rígido granulado para alimentação direta por moldagem. A moldagem por injeção direta foi realizada com sucesso não sendo necessário a compostagem prévia, o que foi considerado conveniente, pois reduziu as etapas de processamento da resina de PVC e que proporcionou, possivelmente, redução de custos, redução da degradação do comprimento médio das fibras de vidro e diminuição da possibilidade de degradação da resina de PVC. O reforçamento do PVC rígido com 20% em massa de fibras de vidro longas de comprimento inicial entre 13 e 14 mm resultou em adequadas propriedades mecânicas, bem superiores ao PVC rígido não reforçado. Os módulos (tração e flexão e a resistência ao impacto Charpy praticamente dobraram, mesmo com os compósitos apresentando grande quantidade de plastificante em sua formulação, que possibilita ao PVC ser utilizado em outras aplicações não antes possíveis como em peças técnicas de engenharia.In this paper, a method to reinforce rigid PVC with long glass fibers (LGF was developed through the incorporation of continuous glass fibers, as rovings, with plasticized vinyl matrix prepared by the wire coating technique. The plasticized vinyl rovings were pelletized. The pellets (13-14 mm were then blended to a granulated rigid PVC formulation and directly injection molded as testing specimens. The direct injection molding, eliminating the preliminary melt-compounding process, was achieved successfully, which was considered convenient because it reduced the number of processing steps, which allowed cutting expenses, reduced the deterioration of the

  17. Messenger RNA for membrane-type 2 matrix metalloproteinase, MT2-MMP, is expressed in human placenta of first trimester.

    Science.gov (United States)

    Bjørn, S F; Hastrup, N; Larsen, J F; Lund, L R; Pyke, C

    2000-01-01

    An intimately regulated cell surface activation of matrix metalloproteinases (MMPs) is believed to be of critical importance for the control of trophoblast invasion. A histological investigation of the expression and localization of three different MMPs, the membrane-type matrix metalloproteinases 1 and 2 (MT1-MMP, MT2-MMP) and matrix metalloproteinase 2 (MMP-2/gelatinase A) was performed by in situ hybridization on consecutive sections from human placentae of first trimester pregnancies. Cytokeratin immunostaining identified trophoblast cells. Both normal and tubal implantation sites were studied. We observed a high degree of coexpression of MT2-MMP, MT1-MMP and MMP-2 mRNAs in single extravillous cytotrophoblasts that had invaded the endometrium and tubal wall. Furthermore, mRNAs for all three genes were also seen in cytotrophoblasts of cell islands. In contrast to this coexpression pattern, MT2-MMP expression was absent from cell columns and decidual cells, in which signals for MT1-MMP and MMP-2 mRNAs were seen. The present data on the cellular expression of MT2-MMP mRNA in placenta extend our knowledge of the proteolytic events that take place during early pregnancy. The data suggest that MT2-MMP, capable of activating MMP-2 in vitro, is involved in the invasion of extravillous cytotrophoblast, possibly related to the physiological activation of MMP-2. Copyright 2000 Harcourt Publishers Ltd.

  18. Mitochondrial matrix delivery using MITO-Porter, a liposome-based carrier that specifies fusion with mitochondrial membranes

    International Nuclear Information System (INIS)

    Yasuzaki, Yukari; Yamada, Yuma; Harashima, Hideyoshi

    2010-01-01

    Mitochondria are the principal producers of energy in cells of higher organisms. It was recently reported that mutations and defects in mitochondrial DNA (mtDNA) are associated with various mitochondrial diseases including a variety of neurodegenerative and neuromuscular diseases. Therefore, an effective mitochondrial gene therapy and diagnosis would be expected to have great medical benefits. To achieve this, therapeutic agents need to be delivered into the innermost mitochondrial space (mitochondrial matrix), which contains the mtDNA pool. We previously reported on the development of MITO-Porter, a liposome-based carrier that introduces macromolecular cargos into mitochondria via membrane fusion. In this study, we provide a demonstration of mitochondrial matrix delivery and the visualization of mitochondrial genes (mtDNA) in living cells using the MITO-Porter. We first prepared MITO-Porter containing encapsulated propidium iodide (PI), a fluorescent dye used to stain nucleic acids to detect mtDNA. We then confirmed the emission of red-fluorescence from PI by conjugation with mtDNA, when the carriers were incubated in the presence of isolated rat liver mitochondria. Finally, intracellular observation by confocal laser scanning microscopy clearly verified that the MITO-Porter delivered PI to the mitochondrial matrix.

  19. Gas transport properties of novel mixed matrix membranes made of titanate nanotubes and PBI or PPO

    Czech Academy of Sciences Publication Activity Database

    Giel, Verena; Galajdová, Barbora; Popelková, Daniela; Kredatusová, Jana; Trchová, Miroslava; Pavlova, Ewa; Beneš, Hynek; Válek, R.; Peter, Jakub

    2015-01-01

    Roč. 56, č. 12 (2015), s. 3285-3293 ISSN 1944-3994. [International Conference on Membrane and Electromembrane Processes - MELPRO 2014. Prague, 18.05.2014-21.05.2014] R&D Projects: GA ČR(CZ) GPP106/12/P643 Institutional support: RVO:61389013 Keywords : polybenzimidazole * poly(phenylene oxide) * titanate nanotubes Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.272, year: 2015

  20. Application of time-of-flight mass spectrometry with laser-based photoionization methods for analytical pyrolysis of PVC

    Energy Technology Data Exchange (ETDEWEB)

    Streibel, T.; Muehlberger, F. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany); Adam, T.; Zimmermann, R. [Augsburg Univ. (Germany); Cao, L. [National Center for Iron and Steel, Beijing, BJ (China)

    2004-09-15

    Chlorinated benzenes and phenols generated from PVC pyrolysis are known to be precursors of PCDD/F formation. Therefore, selective and sensitive monitoring of these substances during PVC pyrolysis processes on an on-line, real-time basis could be very useful for the understanding of PCDD/F formation pathways. In this study, we investigated the pyrolysis gas from PVC samples derived from steel recycling by means of simultaneous single photon ionization/resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (SPI/REMPI-TOFMS). The application of these soft photo-ionization techniques in mass spectrometry enables a fast and comprehensive analysis of this complex matrix without generating fragment ions, which would interfere with molecule ions making interpretation of the obtained mass spectra very difficult.

  1. LIM kinase1 modulates function of membrane type matrix metalloproteinase 1: implication in invasion of prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Chakrabarti Ratna

    2011-01-01

    Full Text Available Abstract Background LIM kinase 1 (LIMK1 is an actin and microtubule cytoskeleton modulatory protein that is overexpressed in a number of cancerous tissues and cells and also promotes invasion and metastasis of prostate and breast cancer cells. Membrane type matrix metalloproteinase 1 (MT1-MMP is a critical modulator of extracellular matrix (ECM turnover through pericellular proteolysis and thus plays crucial roles in neoplastic cell invasion and metastasis. MT1-MMP and its substrates pro-MMP-2 and pro-MMP-9 are often overexpressed in a variety of cancers including prostate cancer and the expression levels correlate with the grade of malignancy in prostate cancer cells. The purpose of this study is to determine any functional relation between LIMK1 and MT1-MMP and its implication in cell invasion. Results Our results showed that treatment with the hydroxamate inhibitor of MT1-MMP, MMP-2 and MMP-9 ilomastat inhibited LIMK1-induced invasion of benign prostate epithelial cells. Over expression of LIMK1 resulted in increased collagenolytic activity of MMP-2, and secretion of pro-MMP2 and pro-MMP-9. Cells over expressing LIMK1 also exhibited increased expression of MT1-MMP, transcriptional activation and its localization to the plasma membrane. LIMK1 physically associates with MT1-MMP and is colocalized with it to the Golgi vesicles. We also noted increased expression of both MT1-MMP and LIMK1 in prostate tumor tissues. Conclusion Our results provide new information on regulation of MT1-MMP function by LIMK1 and showed for the first time, involvement of MMPs in LIMK1 induced cell invasion.

  2. Evaluation of retail fresh meat packagings covered with stretch films of plasticized PVC and non-PVC alternatives

    DEFF Research Database (Denmark)

    Petersen, Jens Højslev; Togeskov, P.; Hallas, J.

    2004-01-01

    The characteristics and performance of several non-PVC stretch films were compared to those of plasticized PVC. Initially the main polymer components Of the film were identified by infrared spectrometry and differential scanning calorimetry. The differences between films in mechanical properties......, such as puncture resistance and tensile strength, varied about a factor of two, while the differences in elongation at break were considerably higher. Plasticized PVC showed properties somewhere in the middle. The water vapour transmission was highest for PVC, while its permeability to oxygen was the lowest...

  3. The Force Exerted by the Membrane Potential During Protein Import into the Mitochondrial Matrix

    Science.gov (United States)

    Shariff, Karim; Ghosal, Sandip; Matouschek, Andreas

    2002-01-01

    The electrostatic force exerted on a targeting sequence by the electrical potential across the inner mitochondrial membrane is calculated and found to vary from 1.4 pN to 2.2 pN (per unit elementary charge) as the radius of the inner membrane pore (assumed aqueous) is varied from 12 to 6.5 Angstroms, its measured range. Since the pore is not very much wider than the distance between water molecules, the full shielding effect of water may not be present; the extreme case of a nonaqueous pore gives a force of 3.1 pN per unit charge, which represents an upper limit. When applied to mitochondrial import experiments on the protein harness, these results imply that a force of 11 plus or minus 4 pN is sufficient to catalyze the unfolding of harness during import. Comparison of these results with unfolding forces measured using atomic force microscopy suggests that the two are not inconsistent.

  4. Cell Adhesion to Plasma-Coated PVC

    Directory of Open Access Journals (Sweden)

    Elidiane C. Rangel

    2014-01-01

    Full Text Available To produce environments suitable for cell culture, thin polymer films were deposited onto commercial PVC plates from radiofrequency acetylene-argon plasmas. The proportion of argon in the plasmas, PAr, was varied from 5.3 to 65.8%. The adhesion and growth of Vero cells on the coated surfaces were examined for different incubation times. Cytotoxicity tests were performed using spectroscopic methods. Carbon, O, and N were detected in all the samples using XPS. Roughness remained almost unchanged in the samples prepared with 5.3 and 28.9% but tended to increase for the films deposited with PAr between 28.9 and 55.3%. Surface free energy increased with increasing PAr, except for the sample prepared at 28.9% of Ar, which presented the least reactive surface. Cells proliferated on all the samples, including the bare PVC. Independently of the deposition condition there was no evidence of cytotoxicity, indicating the viability of such coatings for designing biocompatible devices.

  5. PET and PVC Separation with Hyperspectral Imagery

    Science.gov (United States)

    Moroni, Monica; Mei, Alessandro; Leonardi, Alessandra; Lupo, Emanuela; La Marca, Floriana

    2015-01-01

    Traditional plants for plastic separation in homogeneous products employ material physical properties (for instance density). Due to the small intervals of variability of different polymer properties, the output quality may not be adequate. Sensing technologies based on hyperspectral imaging have been introduced in order to classify materials and to increase the quality of recycled products, which have to comply with specific standards determined by industrial applications. This paper presents the results of the characterization of two different plastic polymers—polyethylene terephthalate (PET) and polyvinyl chloride (PVC)—in different phases of their life cycle (primary raw materials, urban and urban-assimilated waste and secondary raw materials) to show the contribution of hyperspectral sensors in the field of material recycling. This is accomplished via near-infrared (900–1700 nm) reflectance spectra extracted from hyperspectral images acquired with a two-linear-spectrometer apparatus. Results have shown that a rapid and reliable identification of PET and PVC can be achieved by using a simple two near-infrared wavelength operator coupled to an analysis of reflectance spectra. This resulted in 100% classification accuracy. A sensor based on this identification method appears suitable and inexpensive to build and provides the necessary speed and performance required by the recycling industry. PMID:25609050

  6. PET and PVC separation with hyperspectral imagery.

    Science.gov (United States)

    Moroni, Monica; Mei, Alessandro; Leonardi, Alessandra; Lupo, Emanuela; Marca, Floriana La

    2015-01-20

    Traditional plants for plastic separation in homogeneous products employ material physical properties (for instance density). Due to the small intervals of variability of different polymer properties, the output quality may not be adequate. Sensing technologies based on hyperspectral imaging have been introduced in order to classify materials and to increase the quality of recycled products, which have to comply with specific standards determined by industrial applications. This paper presents the results of the characterization of two different plastic polymers--polyethylene terephthalate (PET) and polyvinyl chloride (PVC)--in different phases of their life cycle (primary raw materials, urban and urban-assimilated waste and secondary raw materials) to show the contribution of hyperspectral sensors in the field of material recycling. This is accomplished via near-infrared (900-1700 nm) reflectance spectra extracted from hyperspectral images acquired with a two-linear-spectrometer apparatus. Results have shown that a rapid and reliable identification of PET and PVC can be achieved by using a simple two near-infrared wavelength operator coupled to an analysis of reflectance spectra. This resulted in 100% classification accuracy. A sensor based on this identification method appears suitable and inexpensive to build and provides the necessary speed and performance required by the recycling industry.

  7. The dimer interface of the membrane type 1 matrix metalloproteinase hemopexin domain: crystal structure and biological functions.

    Science.gov (United States)

    Tochowicz, Anna; Goettig, Peter; Evans, Richard; Visse, Robert; Shitomi, Yasuyuki; Palmisano, Ralf; Ito, Noriko; Richter, Klaus; Maskos, Klaus; Franke, Daniel; Svergun, Dmitri; Nagase, Hideaki; Bode, Wolfram; Itoh, Yoshifumi

    2011-03-04

    Homodimerization is an essential step for membrane type 1 matrix metalloproteinase (MT1-MMP) to activate proMMP-2 and to degrade collagen on the cell surface. To uncover the molecular basis of the hemopexin (Hpx) domain-driven dimerization of MT1-MMP, a crystal structure of the Hpx domain was solved at 1.7 Å resolution. Two interactions were identified as potential biological dimer interfaces in the crystal structure, and mutagenesis studies revealed that the biological dimer possesses a symmetrical interaction where blades II and III of molecule A interact with blades III and II of molecule B. The mutations of amino acids involved in the interaction weakened the dimer interaction of Hpx domains in solution, and incorporation of these mutations into the full-length enzyme significantly inhibited dimer-dependent functions on the cell surface, including proMMP-2 activation, collagen degradation, and invasion into the three-dimensional collagen matrix, whereas dimer-independent functions, including gelatin film degradation and two-dimensional cell migration, were not affected. These results shed light on the structural basis of MT1-MMP dimerization that is crucial to promote cellular invasion.

  8. Construction and characterization of human oral mucosa equivalent using hyper-dry amniotic membrane as a matrix.

    Science.gov (United States)

    Qi, Fangfang; Yoshida, Toshiko; Koike, Takeshi; Aizawa, Hitoshi; Shimane, Tetsu; Li, Yinghui; Yamada, Shinichi; Okabe, Motonori; Nikaido, Toshio; Kurita, Hiroshi

    2016-05-01

    Human amniotic membrane(HAM) as a graft material has been used in various fields. Hyper-dry amniotic membrane (HD-AM) is a novel dried amniotic membrane that is easy to handle and can be preserved at room temperature without time limitation. The purpose of this study was to investigate the useful properties of HD-AM in reconstruction of the oral mucosa. Human oral keratinocytes were isolated and seeded on HD-AM in serum-free culture system. Oral mucosa equivalent (OME) was developed and transplanted onto full-thickness wound on athymic mice. The wound healing was analyzed and the OME both before and after transplantation was analyzed with hematoxylin-eosin staining and immunohistochemical staining for Cytokines 10 (CK10), Cytokines 16 (CK16), and Ivolucrin (IVL). Oral keratinocytes spread and proliferated well on HD-AM. Two weeks after air-lifting, OME had formed with good differentiation and morphology. We confirmed immunohistochemically that the expression of CK10 was positive in all suprabasal layers, as was CK16 in the upper layers, while IVL was present in all cell layers. Three weeks after transplantation to athymic mice, the newly generated tissue had survived well with the smallest contraction. The epithelial cells of newly generated tissue expressed CK10 throughout in all suprabasal layers, IVL was mainly in the granular layer, and CK16 positive cells were observed in all spinous layer and granular layer but were not expressed in the mouse skin, all of which were similar to native gingival mucosa. The OME with HD-AM as a matrix revealed a good morphology and stable wound healing. This study demonstrates that HD-AM is a useful and feasible biomaterial for oral mucosa reconstruction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Comparative Study of MIL-96(Al) as Continuous Metal-Organic Frameworks Layer and Mixed-Matrix Membrane.

    Science.gov (United States)

    Knebel, Alexander; Friebe, Sebastian; Bigall, Nadja Carola; Benzaqui, Marvin; Serre, Christian; Caro, Jürgen

    2016-03-23

    MIL-96(Al) layers were prepared as supported metal-organic frameworks membrane via reactive seeding using the α-alumina support as the Al source for the formation of the MIL-96(Al) seeds. Depending on the solvent mixture employed during seed formation, two different crystal morphologies, with different orientation of the transport-active channels, have been formed. This crystal orientation and habit is predefined by the seed crystals and is kept in the subsequent growth of the seeds to continuous layers. In the gas separation of an equimolar H2/CO2 mixture, the hydrogen permeability of the two supported MIL-96(Al) layers was found to be highly dependent on the crystal morphology and the accompanied channel orientation in the layer. In addition to the neat supported MIL-96(Al) membrane layers, mixed-matrix membranes (MMMs, 10 wt % filler loading) as a composite of MIL-96(Al) particles as filler in a continuous Matrimid polymer phase have been prepared. Five particle sizes of MIL-96(Al) between 3.2 μm and 55 nm were synthesized. In the preparation of the MIL-96(Al)/Matrimid MMM (10 wt % filler loading), the following preparation problems have been identified: The bigger micrometer-sized MIL-96(Al) crystals show a trend toward sedimentation during casting of the MMM, whereas for nanoparticles aggregation and recrystallization to micrometer-sized MIL-96(Al) crystals has been observed. Because of these preparation problems for MMM, the neat supported MIL-96(Al) layers show a relatively high H2/CO2 selectivity (≈9) and a hydrogen permeance approximately 2 magnitudes higher than that of the best MMM.

  10. PVC-membrane potentiometric sensors based on a recently ...

    African Journals Online (AJOL)

    It has a fast response time of <12 s and can be used for ten weeks without any considerable divergences in its potentials .the electrode can be used in the pH range 4.5-8.0. The proposed sensor shows fairly good discriminating ability towards Fe(III) ion in comparison with a large number of alkali, alkaline earth, transition ...

  11. Radiation cross-linked PVC and its applications

    International Nuclear Information System (INIS)

    Lan Junming; Chen Ruyan; Jia Chaoxing; Li Min; Li Chengxin

    1990-04-01

    The radiation cross-linking technique is adopted for improving the polyvinyl chloride (PVC) heat-resistance and reducing its thermocontractibility. For examining its properties a small insulation sheath made from modified PVC material has been tested at 260 0 5 seconds. The results obtained were satisfactory

  12. Strawberries packaged with Polyvinyl Chloride (PVC film/ Morangos embalados com filme de Ppolicloreto de Vinila (PVC

    Directory of Open Access Journals (Sweden)

    Sergio Ruffo Roberto

    2006-06-01

    Full Text Available Strawberries cv. Dover with approximately 75% of their surface with red color was packaged in disposable polyethylene terephthalate (PET container and sealed with PVC film of 15mm thick. Strawberries without film serves as control. The fruits were stored at 12°C for ten days and there were determined during storage time the titratable acidity, solid soluble and vitamin C contents, color, respiration rate, texture and weight loss. After 6 days the strawberries packaged without film had decayed while the fruits packaged with PVC film were in conditions of consumption and commercialization. After 10 days all fruits were inappropriate to consumption. Packages with PVC film extended the shelf life of strawberries preserving the color characteristic of the product and vitamin C content, reducing the respiration rate and weight loss, characterizing this packaging as being adequate to this kind of product.Foram utilizados morangos cv. Dover com aproximadamente 75% de sua superfície com coloração vermelha e embalados em potes de polietileno tereftalato (PET. No tratamento CONTROLE os morangos foram acondicionados sem filme e no tratamento FILME, as embalagens foram seladas com filme de PVC de 15mm de espessura. As frutas foram armazenadas a 12°C por dez dias e foram determinadas ao longo do tempo acidez titulável, sólidos solúveis, vitamina C, cor, taxa de respiração, textura e perda de massa. Após 6 dias de armazenagem os morangos CONTROLE estavam impróprios para consumo pois apresentavam deterioração visível por bolores enquanto que os embalados com PVC estavam em condições de consumo e comercialização. Após 10 dias todos os morangos estavam impróprios para consumo. A embalagem utilizando filme de PVC aumentou a vida de prateleira de morangos em relação aos sem embalagem pois preservou melhor a coloração característica do produto e teor de vitamina C e reduziu as taxas de respiração e de perda de massa, caracterizando a

  13. Degradation studies on plasticized PVC films submited to gamma radiation

    Directory of Open Access Journals (Sweden)

    Vinhas Glória Maria

    2003-01-01

    Full Text Available Poly (vinyl chloride, PVC, is a rigid polymer and for several of its applications must be compounded with plasticizing agents. The plasticizers minimize the dipolar interactions, which exist between the polymer's chains, promoting their mobility. In this work we studied the properties of PVC/plasticizer systems submitted to different doses of gamma radiation. We have used four commercial plasticizers amongt them di(2-ethylhexyl phthalate, DEHP, which is present in a great number of commercial applications. The PVC/plasticizer systems have been studied as films made by the solvent evaporation technique. Irradiated and non-irradiated films have been characterized by viscosimetric analysis, mechanical essays and infrared spectroscopy. The results have shown that the rigid, non plasticized, PVC film presented the greatest degradation index, while among the plasticized films the one which presented the larger degradation index due to chain scission was the DEHP plasticized PVC.

  14. Degradation studies on plasticised PVC films submitted to gamma radiation

    International Nuclear Information System (INIS)

    Vinhas, Gloria Maria; Souto-Maior, Rosa Maria; Lapa, Camila Maria; Almeida, Yeda Medeiros Bastos de

    2003-01-01

    Poly (vinyl chloride), PVC, is a rigid polymer and for several of its applications must be compounded with plasticizing agents. The plasticizers minimize the dipolar interactions, which exist between the polymer's chains, promoting their mobility. In this work we studied the properties of PVC/plasticizer systems submitted to different doses of gamma radiation. We have used four commercial plasticizers among them di(2-ethylhexyl) phthalate, DEHP, which is present in a great number of commercial applications. The PVC/plasticizer systems have been studied as films made by the solvent evaporation technique. Irradiated and non-irradiated films have been characterized by viscosimetric analysis, mechanical essays and infrared spectroscopy. The results have shown that the rigid, non plasticized, PVC film presented the greatest degradation index, while among the plasticised films the one which presented the larger degradation index due to chain scission was the DEHP plasticised PVC. (author)

  15. Study of the relationship between mononuclear inflammatory infiltrate and Ki-67 and basement membrane and extracellular matrix protein expression in radicular cysts.

    Science.gov (United States)

    Mourão, R V C; Júnior, E C Pinheiro; Barros Silva, P G; Turatti, E; Mota, M R L; Alves, A P N N

    2016-05-01

    To evaluate the relationship between mononuclear inflammatory infiltrate and the expression of a proliferative immunomarker (Ki-67) as well as to evaluate basement membrane and extracellular matrix proteins (laminin and collagen type IV) in radicular cysts and dentigerous cysts (DC). Immunohistochemical analyses were performed in heavily inflamed radicular cysts (HIRC), slightly inflamed radicular cysts (SIRC) and DC (n = 20) using Ki-67 (Dako(®) , 1 : 50), anticollagen type IV (DBS(®) , 1 : 40) and antilaminin (DBS(®) , 1 : 20). The data were analysed using anova/Tukey's test (Ki-67) and Kruskal-Wallis/Dunn's test (collagen type IV and laminin) (P collagen type IV in the basement membrane of the SIRC group was significantly more continuous (P = 0.0475) than in the HIRC group. DC had significantly less collagen type IV in extracellular matrix immunoexpression than HIRC and SIRC (P = 0.0246). Laminin was absent in the basement membrane in the SIRC and DC groups, and the extracellular matrix of the HIRC was weak and punctate. The presence of inflammatory factors in the radicular cyst wall modified the expression of proliferation factors in the epithelial lining and the expression of collagen type IV and laminin in the basement membrane, but did not modify extracellular matrix behaviour in radicular cysts. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  16. Thermo-mechanical properties of mixed-matrix membranes encompassing zeolitic imidazolate framework-90 and polyvinylidine difluoride: ZIF-90/PVDF nanocomposites

    Directory of Open Access Journals (Sweden)

    Irina S. Flyagina

    2017-08-01

    Full Text Available Mixed-matrix membranes are contemporary nanocomposite materials with many potential applications, from liquid and gas separations to chemical sensors and biomedicine. We report fabrication of a metal-organic framework (MOF-based nanocomposite, combining polyvinylidene difluoride (PVDF polymer as the matrix and ZIF-90 nanocrystals of up to 30 wt. % filler content. The focus is to establish the processing—microstructure—mechanical property relationships. We reveal the importance for quantifying salient effects of the filler contents: (i tensile strength degrades beyond 10 wt. % and (ii mechanical toughness declines due to membrane embrittlement. These are vital mechanical aspects but widely overlooked in the emergent field of MOF membranes and composites.

  17. Expression of matrix metalloproteinase genes during basement membrane degradation in the metamorphosis of Bombyx mori.

    Science.gov (United States)

    Kawasaki, Hideki; Manickam, Asaithambi; Shahin, Rima; Ote, Manabu; Iwanaga, Masashi

    2018-01-05

    The present study was conducted to clarify the involvement of the basement membrane (BM) in insect metamorphosis through analysis of the expression profile of two types of metalloproteinase (MMP and ADAMTS) genes in several organs, their ecdysone involvement, and the histological change of BM. BM was observed around wing sac and in the wing cavity and around fat bodies at the W0 stage but disappeared after the W3 stage, and wing discs evaginated and fat body cells scattered after the W3 stage. The disappearance of the BM of midgut and silk glands was not observed after the W3 stage, but degenerated epithelium cells in the midgut and shrunken cells in the silk gland were observed after the W3 stage. BmMMP1 showed a peak at P0 in the wing discs, fat bodies, midgut, and silk gland. BmMMP2 showed a broad peak around pupation in the wing discs, fat bodies, midgut, and silk gland. BmADAMTS-1 showed enhanced expression at W2 in the wing discs, fat bodies, midgut, and hemocyte, while BmADAMTS-L showed enhanced expression at W3 in the fat bodies, midgut, silk gland, and hemocyte. After pupation, they showed a different expression in different organs. All of four genes were induced by 20-hydroxyecdysone in wing discs in vitro. The present results suggested the involvement of MMPs and ADAMTS in the BM digestion and the morphogenesis of organs during Bombyx metamorphosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Oil palm empty fruit bunch (OPEFB) fiber reinforced PVC/ENR blend-electron beam irradiation

    International Nuclear Information System (INIS)

    Ratnam, Chantara Thevy; Raju, Gunasunderi; Wan Md Zin Wan Yunus

    2007-01-01

    The effect of irradiation on the tensile properties of oil palm empty fruit bunch (OPEFB) fiber reinforced poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends were studied. The composites were prepared by mixing the fiber and the PVC/ENR blend using HAAKE Rheomixer at 150 deg. C. The composites were then irradiated by using a 3.0 MeV electron beam machine at doses ranging from 0 to 100 kGy in air and room temperature. The tensile strength, Young's modulus, elongation at break and gel fraction of the composites were measured. Comparative studies were also made by using poly(methyl acrylate) grafted OPEFB fiber in the similar blend system. An increase in tensile strength, Young's modulus and gel fraction, with a concurrent reduction in the elongation at break (Eb) of the PVC/ENR/OPEFB composites were observed upon electron beam irradiation. Studies revealed that grafting of the OPEFB fiber with methyl acrylate did not cause appreciable effect to the tensile properties and gel fraction of the composites upon irradiation. The morphology of fractured surfaces of the composites, examined by a scanning electron microscope showed an improvement in the adhesion between the fiber and the matrix was achieved upon grafting of the fiber with methyl acrylate

  19. Karakteristik sifat mekanik, ketahanan api dan pembakaran, dan morfologi nanokomposit campuran PVC dan LDPE

    Directory of Open Access Journals (Sweden)

    Arum Yuniari

    2014-06-01

    Full Text Available The purpose of the study was to determine the effect of addition of low density polyethylene (LDPE and flame retardant on mechanical properties, resistant to fire and burning and morphology from the mixture of polyvinyl chloride (PVC, LDPE, flame retardant, and nanoprecipitated calcium carbonate (NPCC as filler. The materials were mixed in laboplastomill at 215 ºC, torque speed 50 rpm, for 10 minutes. Nanocomposite was prepared by PVC/LDPE variations of 100/15; 100/20; 100/25; and 100/30 phr and flame retardant variations of 30 and 35 phr. The results showed that the hihger of LDPE in nanocomposite increased the hardness and impact resistance, however, it decreased the tensile strength, elongation at break, and density. Addition of flame retardant to the nanocomposites showed good resistance to fire and burning, and optimum mechanical properties were found in using of 35 phr flame retardant.The morphology of the nanocomposite, were observed by Scanning Electron Microscope (SEM confirmed that homogeneous mixture of LDPE dispersed in the PVC matrix.

  20. Mechanical, Spectroscopic and Micro-structural Characterization of Banana Particulate Reinforced PVC Composite as Piping Material

    Directory of Open Access Journals (Sweden)

    B. Dan-asabe

    2016-06-01

    Full Text Available A banana particulate reinforced polyvinyl chloride (PVC composite was developed with considerabley low cost materials having an overall light-weight and good mechanical properties for potential application as piping material. The specimen composite material was produced with the banana (stem particulate as reinforcement using compression molding. Results showed that density and elastic Modulus of the composite decreases and increases respectively with increasing weight fraction of the particulate reinforcement. The tensile strength increased to a maximum of 42 MPa and then decreased steadily. The composition with optimum mechanical property (42 MPa was determined at 8, 62 and 30 % formulation of banana stem particulates (reinforcement, PVC (matrix and Kankara clay (filler respectively with corresponding percentage water absorption of 0.79 %, Young’s Modulus of 1.3 GPa, flexural strength of 92 MPa and density of 1.24 g/cm3. Fourier Transform Infrared (FTIR analysis of the constituents showed identical bands within the range 4000–1000 cm-1 with renown research work. Scanning Electron Microscopy (SEM result showed fairly uniform distribution of constituents’ phases. X-Ray Fluorescence (XRF confirms the X-ray diffraction (XRD result of the presence of minerals of kaolinite, quartz, rutile and illite in the kaolin clay. Comparison with conventional piping materials showed the composite offered a price savings per meter length of 84 % and 25 % when compared with carbon steel and PVC material.

  1. A Mixed Matrix Membrane of Poly (4-methyl-1-pentyne Filled with MIL 53 Particles and Its Application in Carbon Dioxide and Nitrogen Separation

    Directory of Open Access Journals (Sweden)

    Reza Abedini

    2016-05-01

    Full Text Available The performance of poly (4-metyl-1-pentyne as mixed matrix membrane (MMM mixed with MIL 53 particles was studied to separate mixtures of carbon dioxide and nitrogen. MIL 53 particles was added to the polymer matrix with 10, 20 and 30 weight percentages. The adsorption of CO2 and N2 gases by MIL 53 was evaluated and the adsorption data was analyzed by Langmuir equation. Structure and thermal/mechanical properties of prepared membranes were characterized by means of FTIR, SEM, TGA and elongation test. Moreover, the gas permeation properties of membranes were studied by measuring the permeation of pure CO2 and N2. Furthermore, for accurate understanding of the gas permeation properties of the membranes, diffusion and solution coefficient of gases in neat membrane and MMMs were calculated using modified time-lag method. The results from TGA analysis showed that the degradation temperature of MMMs was enhanced and increased to 348ºC for membrane containing 30 wt% of MIL 53. The SEM images also illustrated a relatively uniform dispersion of particles with proper polymer/filler interfaces in the polymer matrix. The gas permeation results revealed that the permeability of both gases (especially CO2 increased with increasing MIL 53 loading, in which the permeability of CO2 increased from 98.74 Barrer in neat membrane to 217.65 Barrer in MMM containing 30 wt% filler. Moreover, calculation of CO2/N2 selectivity depicted that the selectivity enhanced from 16.66 to 22.70. Finally, the performance of MMMs was compared with Robeson’s upper bound in CO2/N2 separation and results showed that the MMM having 30 wt% of MIL 53 took over the Robeson bound.

  2. Matrigel Basement Membrane Matrix influences expression of microRNAs in cancer cell lines

    International Nuclear Information System (INIS)

    Price, Karina J.; Tsykin, Anna; Giles, Keith M.; Sladic, Rosemary T.; Epis, Michael R.; Ganss, Ruth; Goodall, Gregory J.; Leedman, Peter J.

    2012-01-01

    Highlights: ► Matrigel alters cancer cell line miRNA expression relative to culture on plastic. ► Many identified Matrigel-regulated miRNAs are implicated in cancer. ► miR-1290, -210, -32 and -29b represent a Matrigel-induced miRNA signature. ► miR-32 down-regulates Integrin alpha 5 (ITGA5) mRNA. -- Abstract: Matrigel is a medium rich in extracellular matrix (ECM) components used for three-dimensional cell culture and is known to alter cellular phenotypes and gene expression. microRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression and have roles in cancer. While miRNA profiles of numerous cell lines cultured on plastic have been reported, the influence of Matrigel-based culture on cancer cell miRNA expression is largely unknown. This study investigated the influence of Matrigel on the expression of miRNAs that might facilitate ECM-associated cancer cell growth. We performed miRNA profiling by microarray using two colon cancer cell lines (SW480 and SW620), identifying significant differential expression of miRNAs between cells cultured in Matrigel and on plastic. Many of these miRNAs have previously been implicated in cancer-related processes. A common Matrigel-induced miRNA signature comprised of up-regulated miR-1290 and miR-210 and down-regulated miR-29b and miR-32 was identified using RT-qPCR across five epithelial cancer cell lines (SW480, SW620, HT-29, A549 and MDA-MB-231). Experimental modulation of these miRNAs altered expression of their known target mRNAs involved in cell adhesion, proliferation and invasion, in colon cancer cell lines. Furthermore, ITGA5 was identified as a novel putative target of miR-32 that may facilitate cancer cell interactions with the ECM. We propose that culture of cancer cell lines in Matrigel more accurately recapitulates miRNA expression and function in cancer than culture on plastic and thus is a valuable approach to the in vitro study of miRNAs.

  3. Higher Dialysate Matrix Metalloproteinase-2 Levels Are Associated with Peritoneal Membrane Dysfunction

    Science.gov (United States)

    Cho, Yeoungjee; Johnson, David W.; Vesey, David A.; Hawley, Carmel M.; Pascoe, Elaine M.; Clarke, Margaret; Topley, Nicholas

    2016-01-01

    ♦ Background: Peritoneal dialysis (PD) patients develop progressive and cumulative peritoneal injury with longer time spent on PD. The present study aimed to a) describe the trend of peritoneal injury biomarkers, matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1), in incident PD patients, b) to explore the capacity of dialysate MMP-2 to predict peritoneal solute transport rate (PSTR) and peritonitis, and c) to evaluate the influence of neutral pH, low glucose degradation product (GDP) PD solution on these outcomes. ♦ Methods: The study included 178 participants from the balANZ trial who had at least 1 stored dialysate sample. Changes in PSTR and peritonitis were primary outcome measures, and the utility of MMP-2 in predicting these outcomes was analyzed using multilevel linear regression and multilevel Poisson regression, respectively. ♦ Results: Significant linear increases in dialysate MMP-2 and TIMP-1 concentrations were observed (p < 0.001), but neither was affected by the type of PD solutions received (MMP-2: p = 0.07; TIMP-1: p = 0.63). An increase in PSTR from baseline was associated with higher levels of MMP-2 (p = 0.02), and the use of standard solutions over longer PD duration (p = 0.001). The risk of peritonitis was independently predicted by higher dialysate MMP-2 levels (incidence rate ratio [IRR] per ng/mL 1.01, 95% confidence interval [CI] 1.005 – 1.02, p = 0.002) and use of standard solutions (Biocompatible solution: IRR 0.45, 95% CI 0.24 – 0.85, p = 0.01). ♦ Conclusion: Dialysate MMP-2 and TIMP-1 concentrations increased with longer PD duration. Higher MMP-2 levels were associated with faster PSTR and future peritonitis risk. Administration of biocompatible solutions exerted no significant effect on dialysate levels of MMP-2 or TIMP-1, but did counteract the increase in PSTR and the risk of peritonitis associated with the use of standard PD solutions. This is the first longitudinal study to examine

  4. Reconstructing the microstructure of polyimide-silicalite mixed-matrix membranes and their particle connectivity using FIB-SEM tomography.

    Science.gov (United States)

    Diblíková, P; Veselý, M; Sysel, P; Čapek, P

    2018-03-01

    Properties of a composite material made of a continuous matrix and particles often depend on microscopic details, such as contacts between particles. Focusing on processing raw focused-ion beam scanning electron microscope (FIB-SEM) tomography data, we reconstructed three mixed-matrix membrane samples made of 6FDA-ODA polyimide and silicalite-1 particles. In the first step of image processing, backscattered electron (BSE) and secondary electron (SE) signals were mixed in a ratio that was expected to obtain a segmented 3D image with a realistic volume fraction of silicalite-1. Second, after spatial alignment of the stacked FIB-SEM data, the 3D image was smoothed using adaptive median and anisotropic nonlinear diffusion filters. Third, the image was segmented using the power watershed method coupled with a seeding algorithm based on geodesic reconstruction from the markers. If the resulting volume fraction did not match the target value quantified by chemical analysis of the sample, the BSE and SE signals were mixed in another ratio and the procedure was repeated until the target volume fraction was achieved. Otherwise, the segmented 3D image (replica) was accepted and its microstructure was thoroughly characterized with special attention paid to connectivity of the silicalite phase. In terms of the phase connectivity, Monte Carlo simulations based on the pure-phase permeability values enabled us to calculate the effective permeability tensor, the main diagonal elements of which were compared with the experimental permeability. In line with the hypothesis proposed in our recent paper (Čapek, P. et al. (2014) Comput. Mater. Sci. 89, 142-156), the results confirmed that the existence of particle clusters was a key microstructural feature determining effective permeability. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  5. Mixed-Matrix Membranes for CO2 and H2 Gas Separations Using Metal-Organic Framework and Mesoporus Hybrid Silicas

    International Nuclear Information System (INIS)

    Musselman, Inga; Balkus, Kenneth Jr.; Ferraris, John

    2009-01-01

    In this work, we have investigated the separation performance of polymer-based mixed-matrix membranes containing metal-organic frameworks and mesoporous hybrid silicas. The MOF/Matrimid(reg s ign) and MOP-18/Matrimid(reg s ign) membranes exhibited improved dispersion and mechanical strength that allowed high additive loadings with reduced aggregation, as is the case of the 80 wt% MOP-18/Matrimid(reg s ign) and the 80% (w/w) Cu-MOF/Matrimid(reg s ign) membranes. Membranes with up to 60% (w/w) ZIF-8 content exhibited similar mechanical strength and improved dispersion. The H 2 /CO 2 separation properties of MOF/Matrimid(reg s ign) mixed-matrix membranes was improved by either keeping the selectivity constant and increasing the permeability (MOF-5, Cu-MOF) or by improving both selectivity and permeability (ZIF-8). In the case of MOF-5/Matrimid(reg s ign) mixed-matrix membranes, the H 2 /CO 2 selectivity was kept at 2.6 and the H 2 permeability increased from 24.4 to 53.8 Barrers. For the Cu-MOF/Matrimid(reg s ign) mixed-matrix membranes, the H 2 /CO 2 selectivity was kept at 2.05 and the H 2 permeability increased from 17.1 to 158 Barrers. These two materials introduced porosity and uniform paths that enhanced the gas transport in the membranes. When ZIF-8/Matrimid(reg s ign) mixed-matrix membranes were studied, the H 2 /CO 2 selectivity increased from 2.9 to 4.4 and the permeability of H 2 increased from 26.5 to 35.8 Barrers. The increased H 2 /CO 2 selectivity in ZIF-8/Matrimid(reg s ign) membranes was explained by the sieving effect introduced by the ZIF-8 crystals (pore window 0.34 nm) that restricted the transport of molecules larger than H 2 . Materials with microporous and/or mesoporous cavities like carbon aerogel composites with zeolite A and zeolite Y, and membranes containing mesoporous ZSM-5 showed sieving effects for small molecules (e.g. H 2 and CO 2 ), however, the membranes were most selective for CO 2 due to the strong interaction of the zeolites with

  6. Membrane Type-1 Matrix Metalloproteinase Expression in Acute Myeloid Leukemia and Its Upregulation by Tumor Necrosis Factor-α

    Directory of Open Access Journals (Sweden)

    Anna Janowska-Wieczorek

    2012-07-01

    Full Text Available Membrane type-1 matrix metalloproteinase (MT1-MMP has been implicated in tumor invasion, as well as trafficking of normal hematopoietic cells, and acts as a physiologic activator of proMMP-2. In this study we examined MT1-MMP expression in primary acute myeloid leukemia (AML cells. Because tumor necrosis factor (TNF-α is known to be elevated in AML, we also investigated the effect of TNF-α on MT1-MMP expression. We found (i MT1-MMP mRNA expression in 41 out of 43 primary AML samples tested; (ii activation of proMMP-2 in co-cultures of AML cells with normal bone marrow stromal cells; and (iii inhibition of proMMP-2 activation and trans-Matrigel migration of AML cells by gene silencing using MT1-MMP siRNA. Moreover, recombinant human TNF-α upregulated MT1-MMP expression in AML cells resulting in enhanced proMMP-2 activation and trans-Matrigel migration. Thus, AML cells express MT1-MMP and TNF-α enhances it leading to increased MMP-2 activation and most likely contributing to the invasive phenotype. We suggest that MT1-MMP, together with TNF-α, should be investigated as potential therapeutic targets in AML.

  7. Stepwise observation and quantification and mixed matrix membrane separation of CO2 within a hydroxy-decorated porous host.

    Science.gov (United States)

    Morris, Christopher G; Jacques, Nicholas M; Godfrey, Harry G W; Mitra, Tamoghna; Fritsch, Detlev; Lu, Zhenzhong; Murray, Claire A; Potter, Jonathan; Cobb, Tom M; Yuan, Fajin; Tang, Chiu C; Yang, Sihai; Schröder, Martin

    2017-04-01

    The identification of preferred binding domains within a host structure provides important insights into the function of materials. State-of-the-art reports mostly focus on crystallographic studies of empty and single component guest-loaded host structures to determine the location of guests. However, measurements of material properties ( e.g. , adsorption and breakthrough of substrates) are usually performed for a wide range of pressure (guest coverage) and/or using multi-component gas mixtures. Here we report the development of a multifunctional gas dosing system for use in X-ray powder diffraction studies on Beamline I11 at Diamond Light Source. This facility is fully automated and enables in situ crystallographic studies of host structures under (i) unlimited target gas loadings and (ii) loading of multi-component gas mixtures. A proof-of-concept study was conducted on a hydroxyl-decorated porous material MFM-300(V III ) under (i) five different CO 2 pressures covering the isotherm range and (ii) the loading of equimolar mixtures of CO 2 /N 2 . The study has successfully captured the structural dynamics underpinning CO 2 uptake as a function of surface coverage. Moreover, MFM-300(V III ) was incorporated in a mixed matrix membrane (MMM) with PIM-1 in order to evaluate the CO 2 /N 2 separation potential of this material. Gas permeation measurements on the MMM show a great improvement over the bare PIM-1 polymer for CO 2 /N 2 separation based on the ideal selectivity.

  8. Membrane Type-1 Matrix Metalloproteinase Expression in Acute Myeloid Leukemia and Its Upregulation by Tumor Necrosis Factor-α

    International Nuclear Information System (INIS)

    Marquez-Curtis, Leah A.; Shirvaikar, Neeta; Turner, A. Robert; Mirza, Imran; Surmawala, Amir; Larratt, Loree M.; Janowska-Wieczorek, Anna

    2012-01-01

    Membrane type-1 matrix metalloproteinase (MT1-MMP) has been implicated in tumor invasion, as well as trafficking of normal hematopoietic cells, and acts as a physiologic activator of proMMP-2. In this study we examined MT1-MMP expression in primary acute myeloid leukemia (AML) cells. Because tumor necrosis factor (TNF)-α is known to be elevated in AML, we also investigated the effect of TNF-α on MT1-MMP expression. We found (i) MT1-MMP mRNA expression in 41 out of 43 primary AML samples tested; (ii) activation of proMMP-2 in co-cultures of AML cells with normal bone marrow stromal cells; and (iii) inhibition of proMMP-2 activation and trans-Matrigel migration of AML cells by gene silencing using MT1-MMP siRNA. Moreover, recombinant human TNF-α upregulated MT1-MMP expression in AML cells resulting in enhanced proMMP-2 activation and trans-Matrigel migration. Thus, AML cells express MT1-MMP and TNF-α enhances it leading to increased MMP-2 activation and most likely contributing to the invasive phenotype. We suggest that MT1-MMP, together with TNF-α, should be investigated as potential therapeutic targets in AML

  9. Prion Fragment Peptides Are Digested with Membrane Type Matrix Metalloproteinases and Acquire Enzyme Resistance through Cu2+-Binding

    Directory of Open Access Journals (Sweden)

    Aya Kojima

    2014-05-01

    Full Text Available Prions are the cause of neurodegenerative disease in humans and other mammals. The structural conversion of the prion protein (PrP from a normal cellular protein (PrPC to a protease-resistant isoform (PrPSc is thought to relate to Cu2+ binding to histidine residues. In this study, we focused on the membrane-type matrix metalloproteinases (MT-MMPs such as MT1-MMP and MT3-MMP, which are expressed in the brain as PrPC-degrading proteases. We synthesized 21 prion fragment peptides. Each purified peptide was individually incubated with recombinant MT1-MMP or MT3-MMP in the presence or absence of Cu2+ and the cleavage sites determined by LC-ESI-MS analysis. Recombinant MMP-7 and human serum (HS were also tested as control. hPrP61-90, from the octapeptide-repeat region, was cleaved by HS but not by the MMPs tested here. On the other hand, hPrP92-168 from the central region was cleaved by MT1-MMP and MT3-MMP at various sites. These cleavages were inhibited by treatment with Cu2+. The C-terminal peptides had higher resistance than the central region. The data obtained from this study suggest that MT-MMPs expressed in the brain might possess PrPC-degrading activity.

  10. Crosslinkable mixed matrix membranes with surface modified molecular sieves for natural gas purification: I. Preparation and experimental results

    KAUST Repository

    Ward, Jason K.

    2011-07-01

    Dense film mixed matrix membranes (MMMs) comprised of SSZ-13 dispersed in a crosslinkable polyimide (PDMC) were fabricated and evaluated for carbon dioxide/methane separations. MMMs containing 25% (w/w) as-received (AR) SSZ-13 exhibited a carbon dioxide permeability of 153 Barrers with a carbon dioxide/methane ideal selectivity of 34.7 at 65. psia and 35 °C. This represents a permeability enhancement of 129% and a decline in selectivity of 4.7% over neat PDMC (PCO2=66.9 Barrers, αCO2/CH4=36.4). A sieve surface modification procedure was developed with the aim of improving SSZ-13/PDMC MMM transport properties. MMMs containing 25% (w/w) surface modified (SM) SSZ-13 exhibited a carbon dioxide permeability of 148 Barrers and carbon dioxide/methane selectivity of 38.9 at 65. psia and 35 °C, representing enhancements in both permeability and selectivity of 121% and 6.9%, respectively. Mixed gas permeation analyses of MMMs containing SM-SSZ-13 using a 10% carbon dioxide/90% methane mixture shows that permeability and selectivity enhancements of 47% and 13%, respectively, over neat PDMC are possible at 700. psia and 35 °C. © 2011 Elsevier B.V.

  11. Membrane Type-1 Matrix Metalloproteinase Expression in Acute Myeloid Leukemia and Its Upregulation by Tumor Necrosis Factor-α

    Energy Technology Data Exchange (ETDEWEB)

    Marquez-Curtis, Leah A.; Shirvaikar, Neeta [Canadian Blood Services R& D, Edmonton, Alberta T6G 2R8 (Canada); Turner, A. Robert [Departments of Medicine and Oncology, University of Alberta, Edmonton, Alberta T6G 2G3 (Canada); Mirza, Imran [Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta T6G 2B7 (Canada); Surmawala, Amir; Larratt, Loree M. [Departments of Medicine and Oncology, University of Alberta, Edmonton, Alberta T6G 2G3 (Canada); Janowska-Wieczorek, Anna, E-mail: anna.janowska@blood.ca [Canadian Blood Services R& D, Edmonton, Alberta T6G 2R8 (Canada); Departments of Medicine and Oncology, University of Alberta, Edmonton, Alberta T6G 2G3 (Canada)

    2012-07-25

    Membrane type-1 matrix metalloproteinase (MT1-MMP) has been implicated in tumor invasion, as well as trafficking of normal hematopoietic cells, and acts as a physiologic activator of proMMP-2. In this study we examined MT1-MMP expression in primary acute myeloid leukemia (AML) cells. Because tumor necrosis factor (TNF)-α is known to be elevated in AML, we also investigated the effect of TNF-α on MT1-MMP expression. We found (i) MT1-MMP mRNA expression in 41 out of 43 primary AML samples tested; (ii) activation of proMMP-2 in co-cultures of AML cells with normal bone marrow stromal cells; and (iii) inhibition of proMMP-2 activation and trans-Matrigel migration of AML cells by gene silencing using MT1-MMP siRNA. Moreover, recombinant human TNF-α upregulated MT1-MMP expression in AML cells resulting in enhanced proMMP-2 activation and trans-Matrigel migration. Thus, AML cells express MT1-MMP and TNF-α enhances it leading to increased MMP-2 activation and most likely contributing to the invasive phenotype. We suggest that MT1-MMP, together with TNF-α, should be investigated as potential therapeutic targets in AML.

  12. Studies of PVC/ENR blends: blend compositions

    International Nuclear Information System (INIS)

    Chantara Thevy Ratnam; Khairul Zaman Mohd Dahlan; Nasir, M.; Baharin, A.

    2002-01-01

    Blends of poly(vinyl chloride/epoxidized natural rubber (PVC/ENR) were prepared by using Bra bender Plasticorder at compositions ranging from 0-100% PVC. They were blended at 150 degree C mixing temperature, 50 rpm rotor speed and 10 minutes mixing time. The blends were characterized for tensile strength , elongation at break, glass transition temperatures and Fourier transform infra red spectroscopy (FTIR). Results revealed that as the PVC content increases the blend behaviour changes from elastomeric to glassy. However the blends found to be compatible at all compositions. (Author)

  13. Phthalate Migration Study from PVC Grafted by Gamma Radiation

    International Nuclear Information System (INIS)

    Manzoli, J.E.; Duarte, C.; Somesari, E.; Silveira, C.; Paes, H.A.; Manzoli, J.E.; Araujo, F.D.C.; Panzarini, L.C.G.A.

    2009-01-01

    PVC is a useful polymer used for many applications, as packaging of food, blood and in contact with body fluids. The most widely-used plasticizer, to make it flexible, is the phthalate DEHP, and its toxicity is a problem. A special radiation grafting of PVC allows an important reduction of thrombogenic properties, and it could cause changes in the DEHP migration too. In this work it is presented the methodology using gas chromatography and numerical simulation for the measurement of DEHP migration from PVC grafted with monomer DMAEMA. The grafting could be an interesting way to reduce DEHP migration

  14. Preparation and characterization of PVC /ENR/CNTs Nano composites

    International Nuclear Information System (INIS)

    Ratnam, C.T.; Nur Azrini Ramlee; Keong, C.C.

    2011-01-01

    Poly (vinyl chloride), PVC/ epoxidized natural rubber blend, ENR/ carbon nano tubes, CNTs were prepared by using melt and solution blending methods. Addition of 2 phr of CNTs found to cause a drop in the tensile strength, Ts of the 50/ 50 PVC/ ENR blend. The nano composites prepared by the melt blending method exhibited higher values of Ts compared to the nano composites prepared by solution blending. Melt blending found to be an efficient method to prepare PVC/ ENR/ CNTs nano composites. (author)

  15. Crystallographic characterization of the radixin FERM domain bound to the cytoplasmic tail of membrane-type 1 matrix metalloproteinase (MT1-MMP)

    International Nuclear Information System (INIS)

    Terawaki, Shin-ichi; Kitano, Ken; Aoyama, Miki; Hakoshima, Toshio

    2008-01-01

    The radixin FERM domain was shown to bind the MT1-MMP cytoplasmic peptide and crystals of the complex were obtained. ERM proteins play a role in the cross-linking found between plasma membranes and actin filaments. The N-terminal FERM domains of ERM proteins are responsible for membrane association through direct interaction with the cytoplasmic tails of integral membrane proteins. During cell migration and movement, membrane-type 1 matrix metalloproteinase (MT1-MMP) on plasma membranes sheds adhesion molecule CD44 in addition to degrading the extracellular matrix. Here, the interaction between the radixin FERM domain and the MT1-MMP cytoplasmic tail is reported and preliminary crystallographic characterization of crystals of the radixin FERM domain bound to the cytoplasmic tail of MT1-MMP is presented. The crystals belong to space group P6 1 22, with unit-cell parameters a = b = 122.7, c = 128.3 Å, and contain one complex in the crystallographic asymmetric unit. The diffraction data were collected to a resolution of 2.4 Å

  16. Study on Preparation and Properties of PVC Film Modified by Rare Earth

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The transparent PVC films were prepared by tape casting. In the process of preparation, rare earth nitrate, as a kind of modifier, was added to the solution of PVC and THF. These PVC films were tested after being crosslinked by ultraviolet light. It is found that the mechanical and physical properties of all the PVC films modified by rare earth nitrate are greatly enhanced.

  17. A Comparison on Gas Separation between PES(polyethersulfone)/MMT (Na-montmorillonite) and PES/TiO2 Mixed Matrix Membranes

    Czech Academy of Sciences Publication Activity Database

    Liang, Ch.-Y.; Uchytil, Petr; Petričkovič, Roman; Lai, Y.-Ch.; Friess, K.; Šípek, M.; Reddy, M.M.; Suen, S.-Y.

    2012-01-01

    Roč. 92, MAY 18 (2012), s. 57-63 ISSN 1383-5866 R&D Projects: GA ČR GCP106/10/J038 Grant - others:NSCT(TW) NSC:99-2911-I-005-002; NSCT(TW) NSC:99-2923-E-005-001-MY2 Institutional research plan: CEZ:AV0Z40720504 Keywords : mixed matrix membrane * polyethersulfone membrane * sodium montmorillonite Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.894, year: 2012

  18. Prepare and characterization of nanocomposite - mixed matrix membranes based on polycarbonate; Preparo e caracterizacao de membranas polimericas de matriz mista nanocomposito baseadas em policarbonato

    Energy Technology Data Exchange (ETDEWEB)

    Paranhos, Caio M; Pessan, Luiz A., E-mail: caiomp.dema@gmail.co [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais. Lab. de Permeacao e Sorcao; Gomes, Ana C. de O. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas

    2009-07-01

    Mixed matrix membranes based on polycarbonate with different content of sepiolite were prepared by casting. The obtained membranes were characterized by wide-angle X-ray diffraction, thermal analysis, optical transparency and permeation to oxygen. The presence of sepiolite leads to the formation of a polymer-clay interface. The presence of the interface causes the increase in O{sub 2} permeation. Increasing content of sepiolite results in aggregates of sepiolite, which forms preferential channels to the O{sub 2} molecules. This fact is directly related to the strong increasing observed in O{sub 2} permeability. (author)

  19. Economic sensitivity of DAW incineration to PVC content

    International Nuclear Information System (INIS)

    Rossmassler, R.L.

    1986-01-01

    Economic analyses of the volume reduction of low level radwaste, including the incinerator of Dry Active Waste (DAW), spent resins and filter sludges, are performed using the microcomputer code VOLREDUCER. Based on BWR and PWR data taken from previous EPRI work, the sensitivity of incinerator economics to polyvinyl chloride (PVC) content in DAW is examined. An annual cost penalty associated with the presence of PVC in the waste is formulated, and the sensitivity of this penalty to a variety of parameters is determined. The alternative of sorting out PVC from the rest of the waste is compared to incineration with regard to this annual cost penalty. These penalties may range as high as $100,000 annually depending on the waste characteristics and percent of PVC

  20. CONTECH(R) A-2000 polyvinyl chloride (PVC) plastic pipe.

    Science.gov (United States)

    2015-03-01

    Determine the effectiveness and long-term durability of the Contech A-2000 PVC pipe : in an irrigation application. This type of pipe may prove to be a viable alternative to : reinforced concrete pipe (RCP).

  1. High Doses Gamma Radiolysis of PVC: Mechanisms of Degradation

    International Nuclear Information System (INIS)

    Colombani, J.

    2006-01-01

    PVC radiolysis leads to the formation of various degradation products: radicals, gas, oxidized products or polyenes. In order to predict the formation of the degradation products with regard to irradiation and ageing parameters, it is important to improve the understanding of the radiolysis mechanisms of PVC. Thus, we used several analytical techniques (Electron Spin Resonance, Fourier Transform Infrared spectroscopy, Nuclear Magnetic Resonance, Size Exclusion Chromatography) to get information on PVC samples irradiated at high doses (up to 4MGy) under different conditions. Gamma irradiation induces the formation of various radicals into PVC. Older studies were generally focused on the effect of low dose and/or low temperature irradiations on PVC. We present here ESR signals of PVC irradiated at high doses and at room temperature. We show that peroxyl radicals are producted by radiolysis under aerobe conditions and that polyenyl radicals are formed under anaerobe conditions. PVC radiolysis induces gas production and especially hydrogen chloride. Production of hydrogen chloride is well known until 1 MGy. We have studied by FTIR, the evolution of the quantity of HCl produced until 4 MGy. We show that higher irradiation dose leads to the lower radiolytic yield of HCl (G(HCl)). Moreover, G(HCl) obtained in aerobe conditions is about fourfold as great as G(HCl) observed in anaerobe radiolysis. Propagation and termination reactions induce degradation products: polyene sequences and crosslinking reactions are observed under anaerobe conditions; oxidized products with addition of chain scissions are formed under aerobe conditions. Although the literature about PVC radiolysis is rich, the main reacting pathways are not well established. Moreover the high doses studies are almost non-existent. We show by FTIR that aerobe radiolysis induces formation of ketons and acids. NMR experiments confirme these results but also focuse on small acids formed (with 2, 3 or 4 carbons). The

  2. Radiation crosslinking of highly plasticized PVC

    Science.gov (United States)

    Mendizabal, E.; Cruz, L.; Jasso, C. F.; Burillo, G.; Dakin, V. I.

    1996-02-01

    To improve the physical properties of highly plasticized PVC, the polymer was crosslinked by gamma irradiation using a dose rate of 91 kGy/h. The effect of plasticizer type was studied by using three different plasticizers, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB), di(2-ethyl hexyl) phthalate (DOP), and di(2-ethylhexyl terephthalate) (DOTP), and varying irradiation doses. Gel content was determined by soxhlet extraction, tensile measurements were made on a universal testing machine and the mechano-dynamic measurements were made in a dynamic rheometer. It was found that a considerable bonding of plasticizer molecules to macromolelcules takes place along with crosslinking, so that the use of the solvent extraction method for measuring the degree of crosslinking can give erroneous information. Radiation-chemical crosslinking yield ( Gc) and molecular weight of interjunctions chains ( Mc), were calculated for different systems studied. Addition of ethylene glycol dimethacrylate (EGDM) as a crosslinking coagent and dioctyl tin oxide (DOTO) as a stabilizer was also studied. Plasticizers extraction resistance was increased by irradiation treatment.

  3. Radiation crosslinking of highly plasticized PVC

    International Nuclear Information System (INIS)

    Mendizabal, E.; Cruz, L.; Jasso, C.F.; Burillo, G.; Dakin, V.I.

    1996-01-01

    To improve the physical properties of highly plasticized PVC, the polymer was crosslinked by gamma irradiation using a dose rate of 91 kGy/h. The effect of plasticizer type was studied by using three different plasticizers, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB), di(2-ethyl hexyl) phthalate (DOP), and di(2-ethylhexyl terephthalate) (DOTP), and varying irradiation doses. Gel content was determined by soxhlet extraction, tensile measurements were made on a universal testing machine and the mechano-dynamic measurements were made in a dynamic rheometer. It was found that a considerable bonding of plasticizer molecules to macromolecules takes place along with crosslinking, so that the use of the solvent extraction method for measuring the degree of crosslinking can give erroneous information. Radiation-chemical crosslinking yield (G c ) and molecular weight of interjunctions chains (M c ), were calculated for different systems studied. Addition of ethylene glycol dimethyacrylate (EGDM) as a crosslinking coagent and dioctyl tin oxide (DOTO) as a stabilizer was also studied. Plasticizers extraction resistance was increased by irradiation treatment. (author)

  4. PET and PVC Separation with Hyperspectral Imagery

    Directory of Open Access Journals (Sweden)

    Monica Moroni

    2015-01-01

    Full Text Available Traditional plants for plastic separation in homogeneous products employ material physical properties (for instance density. Due to the small intervals of variability of different polymer properties, the output quality may not be adequate. Sensing technologies based on hyperspectral imaging have been introduced in order to classify materials and to increase the quality of recycled products, which have to comply with specific standards determined by industrial applications. This paper presents the results of the characterization of two different plastic polymers—polyethylene terephthalate (PET and polyvinyl chloride (PVC—in different phases of their life cycle (primary raw materials, urban and urban-assimilated waste and secondary raw materials to show the contribution of hyperspectral sensors in the field of material recycling. This is accomplished via near-infrared (900–1700 nm reflectance spectra extracted from hyperspectral images acquired with a two-linear-spectrometer apparatus. Results have shown that a rapid and reliable identification of PET and PVC can be achieved by using a simple two near-infrared wavelength operator coupled to an analysis of reflectance spectra. This resulted in 100% classification accuracy. A sensor based on this identification method appears suitable and inexpensive to build and provides the necessary speed and performance required by the recycling industry.

  5. In vivo imaging of membrane type-1 matrix metalloproteinase with a novel activatable near-infrared fluorescence probe.

    Science.gov (United States)

    Shimizu, Yoichi; Temma, Takashi; Hara, Isao; Makino, Akira; Kondo, Naoya; Ozeki, Ei-Ichi; Ono, Masahiro; Saji, Hideo

    2014-08-01

    Membrane type-1 matrix metalloproteinase (MT1-MMP) is a protease activating MMP-2 that mediates cleavage of extracellular matrix components and plays pivotal roles in tumor migration, invasion and metastasis. Because in vivo noninvasive imaging of MT1-MMP would be useful for tumor diagnosis, we developed a novel near-infrared (NIR) fluorescence probe that can be activated following interaction with MT1-MMP in vivo. MT1-hIC7L is an activatable fluorescence probe comprised of anti-MT1-MMP monoclonal antibodies conjugated to self-assembling polymer micelles that encapsulate NIR dyes (IC7-1, λem : 858 nm) at concentrations sufficient to cause fluorescence self-quenching. In aqueous buffer, MT1-hIC7L fluorescence was suppressed to background levels and increased approximately 35.5-fold in the presence of detergent. Cellular uptake experiments revealed that in MT1-MMP positive C6 glioma cells, MT1-hIC7L showed significantly higher fluorescence that increased with time as compared to hIC7L, a negative control probe lacking the anti-MT1-MMP monoclonal antibody. In MT1-MMP negative MCF-7 breast adenocarcinoma cells, both MT1-hIC7L and hIC7L showed no obvious fluorescence. In addition, the fluorescence intensity of C6 cells treated with MT1-hIC7L was suppressed by pre-treatment with an MT1-MMP endocytosis inhibitor (P imaging using probes intravenously administered to tumor-bearing mice showed that MT1-hIC7L specifically visualized C6 tumors (tumor-to-background ratios: 3.8 ± 0.3 [MT1-hIC7L] vs 3.1 ± 0.2 [hIC7L] 48 h after administration, P fluorescence in MCF-7 tumors. Together, these results show that MT1-hIC7L would be a potential activatable NIR probe for specifically detecting MT1-MMP-expressing tumors. © 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.

  6. Hoechst and Wacker plan joint venture in PVC

    International Nuclear Information System (INIS)

    Young, I.

    1992-01-01

    Restructuring of Europe's petrochemical industry has taken a further step with the announcement that Hoechst (Frankfurt) and Wacker Chemie (Munich) are planning a joint venture in polyvinyl chloride (PVC). The venture would include production, R ampersand D, sales and marketing, plus both companies' PVC recycling activities. However, their vinyl chloride monomer (VCM) plants, and Hoechst's Kalle PVC film business, have been left out. Erich Schnitzler, head of Hoechst's PVC business unit, does not anticipate problems with the European Community's competition directorate. We are both among the middle-sized European PVC producers, and together we would have a 9%-10% market share. Our joint venture would not limit competition. Both partners are hoping for approval from Brussels in first-quarter 1993. Hoechst has 255,000 m.t./year of PVC capacity at Gendorfand Knapsack, while Wacker has 365,000 m.t./year at Burghausen and Cologne. All the units, except Wacker's Cologne plant, are back integrated to VCM. The joint venture would buy VCM from the two parent companies and on the merchant market

  7. Study on physical and electrostatic interactions of counterions in poly(perfluorosulfonic) acid matrix: Characterization of diffusion properties of membrane using radiotracers

    International Nuclear Information System (INIS)

    Suresh, G.; Sodaye, Suparna; Scindia, Y.M.; Pandey, A.K.; Goswami, A.

    2007-01-01

    The self-diffusion coefficients of water and ions were used to study the physical (tortuosity) and electrostatic interactions of counterions in poly(perfluorosulfonic) acid membrane (Nafion-117) matrix. The self-diffusion coefficients of water (D H 2 O m ) were measured in the water swollen Nafion-117 membrane with Zn 2+ , Ca 2+ , Sr 2+ , and Fe 2+ counterions by analyzing the experimental exchange rates between tritium tagged water (HTO) in membrane and equilibrating water. In order to study the effects of equilibrating solution, the HTO-desorption rate profiles between the membrane samples in H + or Cs + forms and equilibrating solution containing CsCl or HCl (0.25mol/L) were measured. It was observed that the HTO-exchange rate profile was slower in case of membrane sample in Cs + -from equilibrated with salt/acid solution than that equilibrated with deionized water in same ionic form. However, HTO-exchange rate profile did not alter in case of H + -form of membrane on equilibration with salt or acid solution. The variation of lnD H 2 O m with polymer volume function V p /(1-V p ), where V p is polymer volume fraction, indicated that: (i) D H 2 O m in the membrane with multivalent counterions was lower than that reported for membrane with monovalent counterions at same V p , and (ii) the linear trends observed in variation of lnD H 2 O m with V p /(1-V p ) for multivalent and monovalent counterions were significantly different. The values of D H 2 O m in membrane normalized with D H 2 O m at V p =0 were taken as an estimate of the tortuosity factor for self-diffusion of ions in the membrane matrix. The self-diffusion coefficients of ions reported in the literature along with tortuosity factor obtained from D H 2 O m in the corresponding ionic forms of the membrane were analyzed to obtain the charge (Z i ) independent electrostatic interaction parameter g(φ) of monovalent and divalent ions in the membrane. This analysis indicated that g(φ) also vary

  8. Regulation of Membrane-Type 4 Matrix Metalloproteinase by SLUG Contributes to Hypoxia-Mediated Metastasis12

    Science.gov (United States)

    Huang, Chi-Hung; Yang, Wen-Hao; Chang, Shyue-Yih; Tai, Shyh-Kuan; Tzeng, Cheng-Hwei; Kao, Jung-Yie; Wu, Kou-Juey; Yang, Muh-Hwa

    2009-01-01

    The hypoxic tumor environment has been shown to be critical to cancer metastasis through the promotion of angiogenesis, induction of epithelial-mesenchymal transition (EMT), and acquisition of invasive potential. However, the impact of hypoxia on the expression profile of the proteolytic enzymes involved in invasiveness is relatively unknown. Membrane-type 4 matrix metalloproteinase (MT4-MMP) is a glycosyl-phosphatidyl inositol-anchored protease that has been shown to be overexpressed in human cancers. However, detailed mechanisms regarding the regulation and function of MT4-MMP expression in tumor cells remain unknown. Here, we demonstrate that hypoxia or overexpression of hypoxia-inducible factor-1α (HIF-1α) induced MT4-MMP expression in human cancer cells. Activation of SLUG, a transcriptional factor regulating the EMT process of human cancers, by HIF-1α was critical for the induction of MT4-MMP under hypoxia. SLUG regulated the transcription of MT4-MMP through direct binding to the E-box located in its proximal promoter. Short-interference RNA-mediated knockdown of MT4-MMP attenuated in vitro invasiveness and in vivo pulmonary colonization of tumor cells without affecting cell migratory ability. MT4-MMP promoted invasiveness and pulmonary colonization through modulation of the expression profile of MMPs and angiogenic factors. Finally, coexpression of HIF-1α and MT4-MMP in human head and neck cancer was predictive of a worse clinical outcome. These findings establish a novel signaling pathway for hypoxia-mediated metastasis and elucidate the underlying regulatory mechanism and functional significance of MT4-MMP in cancer metastasis. PMID:20019845

  9. Optimization of polymeric triiodide membrane electrode based on clozapine-triiodide ion-pair using experimental design.

    Science.gov (United States)

    Farhadi, Khalil; Bahram, Morteza; Shokatynia, Donya; Salehiyan, Floria

    2008-07-15

    Central composite design (CCD) and response surface methodology (RSM) were developed as experimental strategies for modeling and optimization of the influence of some variables on the performance of a new PVC membrane triiodide ion-selective electrode. This triiodide sensor is based on triiodide-clozapine ion-pair complexation. PVC, plasticizers, ion-pair amounts and pH were investigated as four variables to build a model to achieve the best Nernstian slope (59.9 mV) as response. The electrode is prepared by incorporating the ion-exchanger in PVC matrix plasticized with 2-nitrophenyl octal ether, which is directly coated on the surface of a graphite electrode. The influence of foreign ions on the electrode performance was also investigated. The optimized membranes demonstrate Nernstian response for triiodide ions over a wide linear range from 5.0 x 10(-6) to 1.0 x 10(-2)mol L(-1) with a limit of detection 2.0 x 10(-6) mol L(-1) at 25 degrees C. The electrodes could be used over a wide pH range 4-8, and have the advantages of easy to prepare, good selectivity and fast response time, long lifetime (over 3 months) and small interferences from hydrogen ion. The proposed electrode was successfully used as indicator electrode in potentiometric titration of triiodide ions and ascorbic acid.

  10. Mesoporous Silica Gel–Based Mixed Matrix Membranes for Improving Mass Transfer in Forward Osmosis: Effect of Pore Size of Filler

    Science.gov (United States)

    Lee, Jian-Yuan; Wang, Yining; Tang, Chuyang Y.; Huo, Fengwei

    2015-01-01

    The efficiency of forward osmosis (FO) process is generally limited by the internal concentration polarization (ICP) of solutes inside its porous substrate. In this study, mesoporous silica gel (SG) with nominal pore size ranging from 4–30 nm was used as fillers to prepare SG-based mixed matrix substrates. The resulting mixed matrix membranes had significantly reduced structural parameter and enhanced membrane water permeability as a result of the improved surface porosity of the substrates. An optimal filler pore size of ~9 nm was observed. This is in direct contrast to the case of thin film nanocomposite membranes, where microporous nanoparticle fillers are loaded to the membrane rejection layer and are designed in such a way that these fillers are able to retain solutes while allowing water to permeate through them. In the current study, the mesoporous fillers are designed as channels to both water and solute molecules. FO performance was enhanced at increasing filler pore size up to 9 nm due to the lower hydraulic resistance of the fillers. Nevertheless, further increasing filler pore size to 30 nm was accompanied with reduced FO efficiency, which can be attributed to the intrusion of polymer dope into the filler pores. PMID:26592565

  11. Mesoporous Silica Gel-Based Mixed Matrix Membranes for Improving Mass Transfer in Forward Osmosis: Effect of Pore Size of Filler.

    Science.gov (United States)

    Lee, Jian-Yuan; Wang, Yining; Tang, Chuyang Y; Huo, Fengwei

    2015-11-23

    The efficiency of forward osmosis (FO) process is generally limited by the internal concentration polarization (ICP) of solutes inside its porous substrate. In this study, mesoporous silica gel (SG) with nominal pore size ranging from 4-30 nm was used as fillers to prepare SG-based mixed matrix substrates. The resulting mixed matrix membranes had significantly reduced structural parameter and enhanced membrane water permeability as a result of the improved surface porosity of the substrates. An optimal filler pore size of ~9 nm was observed. This is in direct contrast to the case of thin film nanocomposite membranes, where microporous nanoparticle fillers are loaded to the membrane rejection layer and are designed in such a way that these fillers are able to retain solutes while allowing water to permeate through them. In the current study, the mesoporous fillers are designed as channels to both water and solute molecules. FO performance was enhanced at increasing filler pore size up to 9 nm due to the lower hydraulic resistance of the fillers. Nevertheless, further increasing filler pore size to 30 nm was accompanied with reduced FO efficiency, which can be attributed to the intrusion of polymer dope into the filler pores.

  12. Antibacterial performance of ZnO-based fillers with mesoscale structured morphology in model medical PVC composites

    Energy Technology Data Exchange (ETDEWEB)

    Machovsky, Michal; Kuritka, Ivo, E-mail: ivo@kuritka.net; Bazant, Pavel; Vesela, Daniela; Saha, Petr

    2014-08-01

    Three different ZnO-based antibacterial fillers having different morphologies in microscale region were prepared by the use of the microwave assisted synthesis protocol created in our laboratory with additional annealing in one case. Further, PVC composites containing 0.5–5 wt.% of ZnO based antibacterial fillers were prepared by melt mixing and characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). Mechanical testing showed no adverse effect on the working of polymer composites due to either of the fillers used or the applied processing conditions in comparison with the neat medical grade PVC. The surface antibacterial activity of the compounded PVC composites was assessed against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P according to ISO 22196: 2007 (E). All materials at almost all filler loading levels were efficient against both species of bacteria. The material with the most expanding morphology assuring the largest contact between filler and matrix achieved an excellent level of more than 99.9999% reduction of viable cells of E. coli in comparison to untreated PVC and performed very well against S. aureus, too. A correlation between the morphology and efficacy of the filler was observed and, as a result, a general rule was formulated which links the proneness of the microparticles to perform well against bacteria to their shape and morphology. - Highlights: • ZnO-based nanostructured microparticles were prepared by microwave synthesis. • Prepared ZnO imparts excellent antibacterial activity to PVC composites. • The microparticulate character of filler makes it processable as common powders. • The inevitable disadvantages of nanoparticles are circumvented. • General rule of proneness of microparticles for antibacterial composites.

  13. Antibacterial performance of ZnO-based fillers with mesoscale structured morphology in model medical PVC composites

    International Nuclear Information System (INIS)

    Machovsky, Michal; Kuritka, Ivo; Bazant, Pavel; Vesela, Daniela; Saha, Petr

    2014-01-01

    Three different ZnO-based antibacterial fillers having different morphologies in microscale region were prepared by the use of the microwave assisted synthesis protocol created in our laboratory with additional annealing in one case. Further, PVC composites containing 0.5–5 wt.% of ZnO based antibacterial fillers were prepared by melt mixing and characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). Mechanical testing showed no adverse effect on the working of polymer composites due to either of the fillers used or the applied processing conditions in comparison with the neat medical grade PVC. The surface antibacterial activity of the compounded PVC composites was assessed against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P according to ISO 22196: 2007 (E). All materials at almost all filler loading levels were efficient against both species of bacteria. The material with the most expanding morphology assuring the largest contact between filler and matrix achieved an excellent level of more than 99.9999% reduction of viable cells of E. coli in comparison to untreated PVC and performed very well against S. aureus, too. A correlation between the morphology and efficacy of the filler was observed and, as a result, a general rule was formulated which links the proneness of the microparticles to perform well against bacteria to their shape and morphology. - Highlights: • ZnO-based nanostructured microparticles were prepared by microwave synthesis. • Prepared ZnO imparts excellent antibacterial activity to PVC composites. • The microparticulate character of filler makes it processable as common powders. • The inevitable disadvantages of nanoparticles are circumvented. • General rule of proneness of microparticles for antibacterial composites

  14. Mixed-Matrix Membranes containing an Azine-Linked Covalent Organic Framework: Influence of the polymeric matrix on Post-Combustion CO 2 -capture

    KAUST Repository

    Shan, Meixia; Seoane, Beatriz; Andres-Garcia, Eduardo; Kapteijn, Freek; Gascon, Jorge

    2017-01-01

    with the good adhesion between the ACOF-1 particles and the polymer matrices were confirmed by scanning electron microscopy. In mixed-gas CO2/N2 separation a clear influence of the polymer used was observed on the performance of the composite membranes. While

  15. The viability of PVC/Al blister reuse and PVC property studies after ionizing radiation processing; Viabilizacao do reaproveitamento dos 'blister' de PVC/Al e estudos das propriedades do PVC apos processamento por radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Alex Terela Pinheiro de

    2008-07-01

    The objective of this research was to separate, by means of a process of dissolution, the PVC and the aluminum that compose blister packs, generally used for pharmaceutical pills. We also studied the effect of the ionizing radiation on the PVC, and, finally, the mechanical recycling of the separated PVC, by a process of extrusion. The material we used in this work is the surplus of the pharmaceutical industry, i.e., packs with defects or burrs. We ground the material to facilitate the handling and the homogenization of the system. After that, we chose two bases for the dissolution of the aluminum: the sodium hydroxide and the potassium hydroxide. We used a system with two concentrations (1 and 2M) for each base, and for every solution we had also an agitated and a non-agitated process. From this method resulted eight experiments. After the dissolution, the samples of the material were submitted to ionizing radiation with doses of 50, 100, 150 and 200 kGy in the Dynamitron II electron accelerator of the CTR-IPEN/CNEN-SP. In the following, these samples were submitted to traction resistance tests to analyze which modifications the irradiation caused. The last step of the research was the recycling of the PVC separated from the Aluminum. We made the recycling in industrial equipment, a PVC tube extruder. The material was combined with lubricants, heat stabilizers and pigment in an intensive mixer and processed into the form of rigid PVC electrical conduits. After the eight experiments, the system with potassium hydroxide base, concentration of 2M and agitation presented the best relation between time of dissolution and characteristics of the resulting material, without degradation of the PVC. In the irradiated samples, the color of the material changed as well as its extension that was as larger as the dose of irradiation they received, indicating the dissociation of the PVC molecules. The extrusion of the PVC was successfully realized: about 200 kg (440 pounds) of

  16. Imaging with radiolabelled anti-membrane type 1 matrix metalloproteinase (MT1-MMP) antibody: potentials for characterizing atherosclerotic plaques

    Energy Technology Data Exchange (ETDEWEB)

    Kuge, Yuji [Kyoto University, Department of Patho-functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Hokkaido University, Department of Tracer Kinetics and Bioanalysis, Graduate School of Medicine, Sapporo (Japan); Hokkaido University, Central Institute of Isotope Science, Sapporo (Japan); Takai, Nozomi; Ogawa, Yuki; Temma, Takashi; Nishigori, Kantaro; Ishino, Seigo; Kamihashi, Junko; Saji, Hideo [Kyoto University, Department of Patho-functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Zhao, Yan [Hokkaido University, Department of Tracer Kinetics and Bioanalysis, Graduate School of Medicine, Sapporo (Japan); Kiyono, Yasushi [Kyoto University, Department of Patho-functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); University of Fukui, Biomedical Imaging Research Center, Fukui (Japan); Shiomi, Masashi [Kobe University Graduate School of Medicine, Institute for Experimental Animals, Kobe (Japan)

    2010-11-15

    Membrane type 1 matrix metalloproteinase (MT1-MMP) activates pro-MMP-2 and pro-MMP-13 to their active forms and plays important roles in the destabilization of atherosclerotic plaques. This study sought to determine the usefulness of {sup 99m}Tc-labelled monoclonal antibody (mAb), recognizing MT1-MMP, for imaging atherosclerosis in a rabbit model (WHHLMI rabbits). Anti-MT1-MMP monoclonal IgG{sub 3} and negative control IgG{sub 3} were radiolabelled with {sup 99m}Tc after derivatization with 6-hydrazinonicotinic acid (HYNIC) to yield {sup 99m}Tc-MT1-MMP mAb and {sup 99m}Tc-IgG{sub 3}, respectively. WHHLMI and control rabbits were injected with these radio-probes. The aorta was removed and radioactivity was measured at 24 h after the injection. Autoradiography and histological studies were performed. {sup 99m}Tc-MT1-MMP mAb accumulation in WHHLMI rabbit aortas was 5.4-fold higher than that of control rabbits. Regional {sup 99m}Tc-MT1-MMP mAb accumulation was positively correlated with MT1-MMP expression (r = 0.59, p < 0.0001), while {sup 99m}Tc-IgG{sub 3} accumulation was independent of MT1-MMP expression (r = 0.03, p = NS). The highest {sup 99m}Tc-MT1-MMP mAb accumulation was found in atheromatous lesions (4.8 {+-} 1.9, %ID x BW/mm{sup 2} x 10{sup 2}), followed in decreasing order by fibroatheromatous (1.8 {+-} 1.3), collagen-rich (1.6 {+-} 1.0) and neointimal lesions (1.5 {+-} 1.5). In contrast, {sup 99m}Tc-IgG{sub 3} accumulation was almost independent of the histological grade of lesions. Higher {sup 99m}Tc-MT1-MMP mAb accumulation in grade IV atheroma was shown in comparison with neointimal lesions or other more stable lesions. Nuclear imaging with {sup 99m}Tc-MT1-MMP mAb, in combination with CT and MRI, could provide new diagnostic imaging capabilities for detecting vulnerable plaques, although further investigations to improve target to blood ratios are strongly required. (orig.)

  17. Radioimmunodetection of membrane type-1 matrix metalloproteinase relevant to tumor malignancy with a pre-targeting method

    International Nuclear Information System (INIS)

    Sano, Kohei; Temma, Takashi; Kuge, Yuji; Kudo, Takashi; Kamihashi, Junko; Saji, Hideo; Zhao, Songji

    2010-01-01

    Since membrane type-1 matrix metalloproteinase (MT1-MMP) is exclusively expressed in tumors and is closely associated with metastasis and invasion, MT1-MMP is a potential target of radiotracers for the evaluation of tumor malignancy. In this study, we planned to visualize MT1-MMP in vivo by a two-step pre-targeting strategy using a streptavidin (SAv)-biotin system combined with anti-MT1-MMP monoclonal immunoglobulin (IgG) (anti-MT1-MMP monoclonal antibody (mAb)). Streptavidinylated anti-MT1-MMP mAb was synthesized by reacting biotinylated anti-MT1-MMP mAb with SAv. In the pre-targeting study, FM3A mouse breast carcinoma-implanted mice were injected with anti-MT1-MMP mAb-SAv, followed 72 h later with radioiodinated biotin, (3-[ 123/125 I]iodobenzoyl)norbiotinamide( 123/125 I-IBB). Biodistribution and imaging (single photon emission computed tomography (SPECT)/CT) data were collected at several time points in the 24 h period following introduction of the tracer. The comparison groups were injected with 125 I-IBB alone or with 125 I-IBB pre-targeted with negative control IgG-SAv. In the pre-targeting study for MT1-MMP, within 1 h of tracer injection, rapid tumor uptake and abrupt clearance from the blood of radioactivity (2.22, 0.87% injected dose/g at 1 h) were observed. The tumor to blood (T/B) radioactivity ratios were significantly higher than those from mice dosed with the pre-targeting negative control (p 125 I-IBB alone did not accumulate in tumors. SPECT/CT image analysis of FM3A bearing mice showed high-contrast tumor images after 3 h with minimal blood-pool activity. The present study that uses a pre-targeting method showed high T/B radioactivity ratios and clear tumor images of MT1-MMP. This imaging method may be useful for the clinical diagnosis of malignant tumors. (author)

  18. Imaging with radiolabelled anti-membrane type 1 matrix metalloproteinase (MT1-MMP) antibody: potentials for characterizing atherosclerotic plaques

    International Nuclear Information System (INIS)

    Kuge, Yuji; Takai, Nozomi; Ogawa, Yuki; Temma, Takashi; Nishigori, Kantaro; Ishino, Seigo; Kamihashi, Junko; Saji, Hideo; Zhao, Yan; Kiyono, Yasushi; Shiomi, Masashi

    2010-01-01

    Membrane type 1 matrix metalloproteinase (MT1-MMP) activates pro-MMP-2 and pro-MMP-13 to their active forms and plays important roles in the destabilization of atherosclerotic plaques. This study sought to determine the usefulness of 99m Tc-labelled monoclonal antibody (mAb), recognizing MT1-MMP, for imaging atherosclerosis in a rabbit model (WHHLMI rabbits). Anti-MT1-MMP monoclonal IgG 3 and negative control IgG 3 were radiolabelled with 99m Tc after derivatization with 6-hydrazinonicotinic acid (HYNIC) to yield 99m Tc-MT1-MMP mAb and 99m Tc-IgG 3 , respectively. WHHLMI and control rabbits were injected with these radio-probes. The aorta was removed and radioactivity was measured at 24 h after the injection. Autoradiography and histological studies were performed. 99m Tc-MT1-MMP mAb accumulation in WHHLMI rabbit aortas was 5.4-fold higher than that of control rabbits. Regional 99m Tc-MT1-MMP mAb accumulation was positively correlated with MT1-MMP expression (r = 0.59, p 99m Tc-IgG 3 accumulation was independent of MT1-MMP expression (r = 0.03, p = NS). The highest 99m Tc-MT1-MMP mAb accumulation was found in atheromatous lesions (4.8 ± 1.9, %ID x BW/mm 2 x 10 2 ), followed in decreasing order by fibroatheromatous (1.8 ± 1.3), collagen-rich (1.6 ± 1.0) and neointimal lesions (1.5 ± 1.5). In contrast, 99m Tc-IgG 3 accumulation was almost independent of the histological grade of lesions. Higher 99m Tc-MT1-MMP mAb accumulation in grade IV atheroma was shown in comparison with neointimal lesions or other more stable lesions. Nuclear imaging with 99m Tc-MT1-MMP mAb, in combination with CT and MRI, could provide new diagnostic imaging capabilities for detecting vulnerable plaques, although further investigations to improve target to blood ratios are strongly required. (orig.)

  19. Improved permeation performance and fouling-resistance of Poly(vinyl chloride/Polycarbonate blend membrane with added Pluronic F127

    Directory of Open Access Journals (Sweden)

    Supateekan Pacharasakoolchai

    2014-04-01

    Full Text Available The aim of this work was to prepare and characterize poly(vinyl chloride (PVC/polycarbonate (PC blend membranes for use in ultrafiltration. Pluronic F127 was used as an additive to modify the membrane surface of the PVC/PC blended membranes. The PVC/PC blend membrane was first prepared using the phase inversion method from a casting solution of PVC with small amount of PC in N-methylpyrrolidone (NMP and water as the non-solvent. The morphologies structure and properties, such as tensile strength, water flux, and bovine serum albumin (BSA rejection of the blend membrane were studied. Increased amounts of PC resulted in an increase in the water flux and ability to reject protein. A concentration of 0.75 wt% PC provided the best improvement in tensile strength of blend membrane. Addition of different amounts of pluronic F127 to the casting solution of PVC/PC with a PC concentration of 0.75 wt% resulted in a decrease in the water contact angle that demonstrated the improvement of hydrophilicity of blend membrane. Scanning electron microscopy photographs showed that the modified PVC/PC membranes had a bigger pore volume in the porous sub-layer compared to the PVC/PC control membrane. The PVC/PC membrane with added Pluronic F127 exhibited a much higher flux and rejection of BSA in a protein filtration experiment than the PVC/PC membrane. An increase in flux recovery ratio of PVC/PC/pluronic 127 blend membrane indicated that the modified membranes could reduce membrane fouling useful for ultrafiltration.

  20. Processing of nanocomposites EVA/PVC/MMT in twin-screw extruder; Processamento de nanocompositos EVA/PVC/MMT em extrusora dupla rosca

    Energy Technology Data Exchange (ETDEWEB)

    Gehlen, A.; Barbutti Filho, W.R.; Francisquetti, E.L.; Andrade, M.Z.; Zattera, A.J., E-mail: ajzatter@ucs.b [Universidade de Caxias do Sul (UCS), RS (Brazil). Lab. de Polimeros

    2010-07-01

    Polymeric nanocomposites have some superior properties when compared to conventional polymer composites and is one of the most promising fields in the nanotechnology research. In a EVA (ethylene vinyl acetate) /PVC (poly vinyl chloride) matrix was incorporated different types of montmorillonite clays (an inorganic (Na{sup +}) and two organic modified (15A and 30B nanoclays). The mixtures were processed in a co-rotating twin-screw extruder at processing speeds of 200 and 400 rpm. Thermogravimetric analysis (TGA) shown that the inorganic and organic modified clays promoted a shift to higher temperatures in the degradation temperature., X-ray diffraction (XRD) and transmission electronic microscopy (TEM) shows a possible intercalation with the 15A clay, exfoliation with the 30B clay and formation of clusters in the Na{sup +} clay. For all clays studied, the increase in shear rate does not promote significant changes. (author)

  1. Effect of radiation on Poly Vinyl chloride (PVC)

    International Nuclear Information System (INIS)

    Massaud, F.; Haraga, S.; Benfaid, N.; Benayad, S.; Kabar, Y.; Elmesmary, Y; Elwerfeli, M.; Omran, Sh.

    1993-01-01

    Radiation crosslinking of polymeric materials is of increasing commercial importance because of the improved thermal, electrical and mechanical properties. Poly Vinylchloride (PVC) is one of the most important polymers. Many attempts were made to study the primary reactions induced by the direct effect of radiation on PVC. In this study, powder PVC was irradiated with different doses at ambient temperature. Formation of free radicals was investigated by electron spin resonance (ESR) method and molecular weight was determined by viscosity measurements. It has been observed that hydrogen chloride was evolved because of noticeable change in color. One type of radical, Poly enyl structure was trapped at room temperature. The non-symmetric singlet structure of the ESR spectra is due to the presence of oxygen. The radical concentration increased with increase of dose. The molecular weight of irradiated PVC was found to be inversely proportional to the increase of radiation dose, which is believed to be due to the occurrence of degradation. It can be concluded that gamma radiation will be the best method for crosslinking of PVC if multi-functional groups or monomers are present. (author)

  2. Recycling of PVC Waste via Environmental Friendly Vapor Treatment

    Science.gov (United States)

    Cui, Xin; Jin, Fangming; Zhang, Guangyi; Duan, Xiaokun

    2010-11-01

    This paper focused on the dechlorination of polyvinyl chloride (PVC), a plastic which is widely used in the human life and thereby is leading to serious "white pollution", via vapor treatment process to recycle PVC wastes. In the process, HCl emitted was captured into water solution to avoid hazardous gas pollution and corruption, and remaining polymers free of chlorine could be thermally degraded for further energy recovery. Optimal conditions for the dechlorination of PVC using vapor treatment was investigated, and economic feasibility of this method was also analyzed based on the experimental data. The results showed that the efficiency of dechlorination increased as the temperature increased from 200° C to 250° C, and the rate of dechlorination up to 100% was obtained at the temperature near 250° C. Meanwhile, about 12% of total organic carbon was detected in water solution, which indicated that PVC was slightly degraded in this process. The main products in solution were identified to be acetone, benzene and toluene. In addition, the effects of alkali catalysis on dechlorination were also studied in this paper, and it showed that alkali could not improve the efficiency of the dechlorination of PVC.

  3. Matrimid®/polysulfone blend mixed matrix membranes containing ZIF-8 nanoparticles for high pressure stability in natural gas separation

    NARCIS (Netherlands)

    Shahid, S.; Nijmeijer, K.

    2017-01-01

    Plasticization is of important concern in high pressure natural gas separation. Majority of the pure polymers and MOF-MMM systems suffer from plasticization at low pressures. Combination of polymer blending and MMM approach could lead to plasticization resistant membranes with improved membrane

  4. Evidence for the existence of multiple heparan sulfate proteoglycans in the human glomerular basement membrane and mesangial matrix

    NARCIS (Netherlands)

    Groffen, Alexander J A; Hop, Frank W H; Tryggvason, Karl; Dijkman, Henri; Assmann, Karel J M; Veerkamp, Jacques H.; Monnens, Leo A H; Van Den Heuvel, Lambert P W J

    1997-01-01

    Heparan sulfate proteoglycans (HSPGs) are essential components of the glomerular basement membrane (GBM) carrying a strong anionic charge. A well- characterized extracellular HSPG is perlecan, ubiquitously expressed in basement membranes. A cDNA construct encoding domains I and II of human perlecan

  5. Matrimid-JUC-62 and Matrimid-PCN-250 mixed matrix membranes displaying light-responsive gas separation and beneficial ageing characteristics for CO2/N2 separation.

    Science.gov (United States)

    Prasetya, Nicholaus; Teck, Anastasia A; Ladewig, Bradley P

    2018-02-13

    The performance of two generation-3 light-responsive metal-organic framework (MOF), namely JUC-62 and PCN-250, was investigated in a mixed matrix membrane (MMM) form. Both of them were incorporated inside the matrimid as the polymer matrix. Using our custom-designed membrane testing cell, it was observed that the MMMs showed up to 9% difference in CO 2 permeability between its pristine and UV-irradiated condition. This shows that the light-responsive ability of the light-responsive MOFs could still be maintained. Thus, this finding is applicable in designing a smart material. Apart from that, the MMMs also has the potential to be applied for post-combustion carbon capture. At loadings up to 15 wt%, both CO 2 permeability and CO 2 /N 2 ideal selectivity could be significantly improved and surpassed the value exhibited by most of the MOF-matrimid MMM. Lastly the long term performance of the MMM was also evaluated and it was observed that both MMM could maintain their performance up to 1 month with only a slight decrease in CO 2 permeability observed for 10 wt% PCN-250-matrimid. This study then opens up the possibility to fabricate a novel anti-aging multifunctional membrane material that is applicable as a smart material and also in post combustion carbon capture applications.

  6. Mixed-matrix membranes with enhanced antifouling activity: probing the surface-tailoring potential of Tiron and chromotropic acid for nano-TiO2

    Science.gov (United States)

    Pal, Avishek; Dey, T. K.; Debnath, A. K.; Bhushan, Bharat; Sahu, A. K.; Bindal, R. C.; Kar, Soumitra

    2017-09-01

    Mixed-matrix membranes (MMMs) were developed by impregnating organofunctionalized nanoadditives within fouling-susceptible polysulfone matrix following the non-solvent induced phase separation (NIPS) method. The facile functionalization of nanoparticles of anatase TiO2 (nano-TiO2) by using two different organoligands, viz. Tiron and chromotropic acid, was carried out to obtain organofunctionalized nanoadditives, FT-nano-TiO2 and FC-nano-TiO2, respectively. The structural features of nanoadditives were evaluated by X-ray diffraction, X-ray photoelectron spectroscopy, Raman and Fourier transform infrared spectroscopy, which established that Tiron leads to the blending of chelating and bridging bidentate geometries for FT-nano-TiO2, whereas chromotropic acid produces bridging bidentate as well as monodentate geometries for FC-nano-TiO2. The surface chemistry of the studied membranes, polysulfone (Psf): FT-nano-TiO2 UF and Psf: FC-nano-TiO2 UF, was profoundly influenced by the benign distributions of the nanoadditives enriched with distinctly charged sites (-SO3 -H+ ), as evidenced by superior morphology, improved topography, enhanced surface hydrophilicity and altered electrokinetic features. The membranes exhibited enhanced solvent throughputs, viz. 3500-4000 and 3400-4300 LMD at 1 bar of transmembrane pressure, without significant compromise in their rejection attributes. The flux recovery ratios and fouling resistive behaviours of MMMs towards bovine serum albumin indicated that the nanoadditives could impart stable and appreciable antifouling activity, potentially aiding in a sustainable ultrafiltration performance.

  7. Proteolytic processing of lysyl oxidase-like-2 in the extracellular matrix is required for crosslinking of basement membrane collagen IV.

    Science.gov (United States)

    López-Jiménez, Alberto J; Basak, Trayambak; Vanacore, Roberto M

    2017-10-13

    Lysyl oxidase-like-2 (LOXL2) is an enzyme secreted into the extracellular matrix that crosslinks collagens by mediating oxidative deamination of lysine residues. Our previous work demonstrated that this enzyme crosslinks the 7S domain, a structural domain that stabilizes collagen IV scaffolds in the basement membrane. Despite its relevant role in extracellular matrix biosynthesis, little is known about the structural requirements of LOXL2 that enable collagen IV crosslinking. In this study, we demonstrate that LOXL2 is processed extracellularly by serine proteases, generating a 65-kDa form lacking the first two scavenger receptor cysteine-rich domains. Site-specific mutagenesis to prevent proteolytic processing generated a full-length enzyme that is active in vitro toward a soluble substrate, but fails to crosslink insoluble collagen IV within the extracellular matrix. In contrast, the processed form of LOXL2 binds to collagen IV and crosslinks the 7S domain. Together, our data demonstrate that proteolytic processing is an important event that allows LOXL2-mediated crosslinking of basement membrane collagen IV. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. PVC makers study expansions to meet demand growth

    International Nuclear Information System (INIS)

    Hunter, D.; Coeyman, M.

    1993-01-01

    As prospects for the polyvinyl chloride (PVC) industry continue to improve, the next batch of capacity increases is being studied. Vista Chemical (Houston) sees an opportunity to achieve what company president James R. Ball calls the lowest-cost capacity addition in the market, by debottlenecking its PVC plants at Aberdeen, MS and Oklahoma City. That would increase capacity 40%, adding 300 million lbs/year to Vista's 830 million lbs/year. US demand for PVC grew 12.5% through the first 10 months of 1992, to 7.3 billion lbs, according to the latest figures available from the Society of the Plastics Industry. Alan Bailey, Oxy-Chem's executive v.p./polymers and plastics, predicts a good demand year in 1993 - better even than 1992, driven by an upward trend in housing starts and a recovering economy

  9. Improvement of PVC floor tiles by gamma radiation

    International Nuclear Information System (INIS)

    Plessis, T.A. du; Badenhorst, F.

    1988-01-01

    Gamma radiation presents a unique method of transforming highly plasticized PVC floor tiles, manufactured at high speed through injection moulding, into a high quality floor covering at a cost at least 30% less than similarly rated rubber tiles. A specially formulated PVC compound was developed in collaboration with a leading manufacturer of floor tiles. These tiles are gamma crosslinked in its shipping cartons to form a dimensionally stable product which is highly fire resistant and inert to most chemicals and solvents. These crosslinked tiles are more flexible than the highly filled conventional PVC floor tiles, scratch resistant and have a longer lifespan and increased colour fastness. These tiles are also less expensive to install than conventional rubber tiles. (author)

  10. PVC removal from mixed plastics by triboelectrostatic separation

    International Nuclear Information System (INIS)

    Park, Chul-Hyun; Jeon, Ho-Seok; Park, Jai-Koo

    2007-01-01

    Ever increasing oil price and the constant growth in generation of waste plastics stimulate a research on material separation for recycling of waste plastics. At present, most waste plastics cause serious environmental problems due to the disposal by reclamation and incineration. Particularly, polyvinyl chloride (PVC) materials among waste plastics generates hazardous HCl gas, dioxins containing Cl, and so on, which lead to air pollution and shorten the life of incinerator, and it makes difficultly recycling of other plastics. Therefore, we designed a bench scale triboelectrostatic separator for PVC removal from mixed plastics (polyvinyl chloride/polyethylene terephthalate), and then carried out material separation tests. In triboelectrostatic separation, PVC and PET particles are charged negatively and positively, respectively, due to the difference of the work function of plastics in tribo charger of the fluidized-bed, and are separated by means of splitter through an opposite electric field. In this study, the charge efficiency of PVC and PET was strongly dependent on the tribo charger material (polypropylene), relative humidity (below 30%), air velocity (over 10 m/s), and mixture ratio (PET:PVC = 1:1). At the optimum conditions (electrode potential of 20 kV and splitter position of -2 cm), PVC rejection and PET recovery in PET products were 99.60 and 98.10%, respectively, and the reproducibility of optimal test was very good (±1%). In addition, as a change of splitter position, we developed the technique to recover high purity PET (over 99.99%) although PET recovery decreases by degrees

  11. Evaluating adhesion reduction efficacy of type I/III collagen membrane and collagen-GAG resorbable matrix in primary flexor tendon repair in a chicken model.

    Science.gov (United States)

    Turner, John B; Corazzini, Rubina L; Butler, Timothy J; Garlick, David S; Rinker, Brian D

    2015-09-01

    Reduction of peritendinous adhesions after injury and repair has been the subject of extensive prior investigation. The application of a circumferential barrier at the repair site may limit the quantity of peritendinous adhesions while preserving the tendon's innate ability to heal. The authors compare the effectiveness of a type I/III collagen membrane and a collagen-glycosaminoglycan (GAG) resorbable matrix in reducing tendon adhesions in an experimental chicken model of a "zone II" tendon laceration and repair. In Leghorn chickens, flexor tendons were sharply divided using a scalpel and underwent repair in a standard fashion (54 total repairs). The sites were treated with a type I/III collagen membrane, collagen-GAG resorbable matrix, or saline in a randomized fashion. After 3 weeks, qualitative and semiquantitative histological analysis was performed to evaluate the "extent of peritendinous adhesions" and "nature of tendon healing." The data was evaluated with chi-square analysis and unpaired Student's t test. For both collagen materials, there was a statistically significant improvement in the degree of both extent of peritendinous adhesions and nature of tendon healing relative to the control group. There was no significant difference seen between the two materials. There was one tendon rupture observed in each treatment group. Surgical handling characteristics were subjectively favored for type I/III collagen membrane over the collagen-GAG resorbable matrix. The ideal method of reducing clinically significant tendon adhesions after injury remains elusive. Both materials in this study demonstrate promise in reducing tendon adhesions after flexor tendon repair without impeding tendon healing in this model.

  12. Amino-Functionalized ZIF-7 Nanocrystals: Improved Intrinsic Separation Ability and Interfacial Compatibility in Mixed-Matrix Membranes for CO2 /CH4 Separation.

    Science.gov (United States)

    Xiang, Long; Sheng, Luqian; Wang, Chongqing; Zhang, Lixiong; Pan, Yichang; Li, Yanshuo

    2017-08-01

    Highly permeable and selective, as well as plasticization-resistant membranes are desired as promising alternatives for cost- and energy-effective CO 2 separation. Here, robust mixed-matrix membranes based on an amino-functionalized zeolitic imidazolate framework ZIF-7 (ZIF-7-NH 2 ) and crosslinked poly(ethylene oxide) rubbery polymer are successfully fabricated with filler loadings up to 36 wt%. The ZIF-7-NH 2 materials synthesized from in situ substitution of 2-aminobenzimidazole into the ZIF-7 structure exhibit enlarged aperture size compared with monoligand ZIF-7. The intrinsic separation ability for CO 2 /CH 4 on ZIF-7-NH 2 is remarkably enhanced as a result of improved CO 2 uptake capacity and diffusion selectivity. The incorporation of ZIF-7-NH 2 fillers simultaneously makes the neat polymer more permeable and more selective, surpassing the state-of-the-art 2008 Robeson upper bound. The chelating effect between metal (zinc) nodes of fillers and ester groups of a polymer provides good bonding, enhancing the mechanical strength and plasticization resistance of the neat polymer membrane. The developed novel ZIF-7 structure with amino-function and the resulting nanocomposite membranes are very attractive for applications like natural-gas sweetening or biogas purification. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Treatment of PVC using an alternative low energy ion bombardment procedure

    Science.gov (United States)

    Rangel, Elidiane C.; dos Santos, Nazir M.; Bortoleto, José Roberto R.; Durrant, Steven F.; Schreiner, Wido H.; Honda, Roberto Y.; Rangel, Rita de Cássia C.; Cruz, Nilson C.

    2011-12-01

    increased after the treatment but such modifications were not stable after aging: the contact angle increased for all the samples, modifying the initially hydrophilic surface into a highly hydrophobic one. Consistently, the surface composition also changed after aging: there was carbon enrichment due to further losses of oxygen and chlorine. Another relevant factor for the elevation of θ was the change in morphology induced by the treatment. At greater powers, the uniform matrix of the PVC was transformed into a columnar structure containing randomly distributed sharp pillars. Interpretation of such results is proposed in terms of the total energy deposited in the solid by ionic collisions.

  14. Treatment of PVC using an alternative low energy ion bombardment procedure

    International Nuclear Information System (INIS)

    Rangel, Elidiane C.; Santos, Nazir M. dos; Bortoleto, José Roberto R.; Durrant, Steven F.; Schreiner, Wido H.; Honda, Roberto Y.; Cássia C Rangel, Rita de; Cruz, Nilson C.

    2011-01-01

    increased after the treatment but such modifications were not stable after aging: the contact angle increased for all the samples, modifying the initially hydrophilic surface into a highly hydrophobic one. Consistently, the surface composition also changed after aging: there was carbon enrichment due to further losses of oxygen and chlorine. Another relevant factor for the elevation of θ was the change in morphology induced by the treatment. At greater powers, the uniform matrix of the PVC was transformed into a columnar structure containing randomly distributed sharp pillars. Interpretation of such results is proposed in terms of the total energy deposited in the solid by ionic collisions.

  15. Estudo do uso de plastificantes de fontes renovável em composições de PVC Study of the use of plasticizer from renewable sources in PVC compositions

    Directory of Open Access Journals (Sweden)

    Emerson Madaleno

    2009-01-01

    compositions of flexible PVC - based on two vegetable plasticizers from renewable sources (modified vegetable oil - OVM and epoxidized modified vegetable oil - OVME, in addition to two conventional petrochemical plasticizers, called di(2-ethylhexyl phthalate-(DEHP and di(2-ethylhexyl adipate-(DEHA. No significant differences were observed in the mechanical behavior of the compositions evaluated. The plasticizers affected the hardness and chemical resistance to n-heptane for the compositions. The epoxi group and the high molar mass from vegetable plasticizers showed better compatibility with the PVC resin. The analyses by SEM showed a probable exudation of OVM from the PVC matrix.

  16. Correlation of Gas Permeability in a Metal-Organic Framework MIL-101(Cr)-Polysulfone Mixed-Matrix Membrane with Free Volume Measurements by Positron Annihilation Lifetime Spectroscopy (PALS).

    Science.gov (United States)

    Jeazet, Harold B Tanh; Koschine, Tönjes; Staudt, Claudia; Raetzke, Klaus; Janiak, Christoph

    2013-10-25

    Hydrothermally stable particles of the metal-organic framework MIL-101(Cr) were incorporated into a polysulfone (PSF) matrix to produce mixed-matrix or composite membranes with excellent dispersion of MIL-101 particles and good adhesion within the polymer matrix. Pure gas (O2, N2, CO2 and CH4) permeation tests showed a significant increase of gas permeabilities of the mixed-matrix membranes without any loss in selectivity. Positron annihilation lifetime spectroscopy (PALS) indicated that the increased gas permeability is due to the free volume in the PSF polymer and the added large free volume inside the MIL-101 particles. The trend of the gas transport properties of the composite membranes could be reproduced by a Maxwell model.

  17. Correlation of Gas Permeability in a Metal-Organic Framework MIL-101(Cr)–Polysulfone Mixed-Matrix Membrane with Free Volume Measurements by Positron Annihilation Lifetime Spectroscopy (PALS)

    Science.gov (United States)

    Jeazet, Harold B. Tanh; Koschine, Tönjes; Staudt, Claudia; Raetzke, Klaus; Janiak, Christoph

    2013-01-01

    Hydrothermally stable particles of the metal-organic framework MIL-101(Cr) were incorporated into a polysulfone (PSF) matrix to produce mixed-matrix or composite membranes with excellent dispersion of MIL-101 particles and good adhesion within the polymer matrix. Pure gas (O2, N2, CO2 and CH4) permeation tests showed a significant increase of gas permeabilities of the mixed-matrix membranes without any loss in selectivity. Positron annihilation lifetime spectroscopy (PALS) indicated that the increased gas permeability is due to the free volume in the PSF polymer and the added large free volume inside the MIL-101 particles. The trend of the gas transport properties of the composite membranes could be reproduced by a Maxwell model. PMID:24957061

  18. Properties of Commercial PVC Films with Respect to Electron Dosimetry

    DEFF Research Database (Denmark)

    Miller, Arne; Liqing, Xie

    The properties of three commercially available polyvinyl chloride (PVC) film supplies and one made without additives were tested with respect to their application as routine dose monitors at electron accelerators. Dose fractionation was found to increase the response and the post-irradiation heat...

  19. Chilled water optimization at Beek INEOS PVC Plant : ammonia cycle

    NARCIS (Netherlands)

    Karami Alaghinloo, B.

    2012-01-01

    In BEEK INEOS PVC plant, polymerization takes place in a suspension process in twenty reactors in five lines. As the reaction is exothermic, a 17MW chilled water unit (CWU) removing heat from reactors which are producing different grades in batch processes. The objective of the project was to

  20. Residual lifetime assessment of uPVC gas pipes

    NARCIS (Netherlands)

    Visser, H.A.

    2010-01-01

    The Dutch gas distribution network consists of about 20% (22,500 km) of unplasticised poly(vinyl chloride) (uPVC) pipes, most of which have been installed from the mid-sixties up to the mid-seventies of the previous century and have been in service ever since. In the next decade the specified

  1. Mixed-matrix membranes with enhanced antifouling activity: probing the surface-tailoring potential of Tiron and chromotropic acid for nano-TiO2.

    Science.gov (United States)

    Pal, Avishek; Dey, T K; Debnath, A K; Bhushan, Bharat; Sahu, A K; Bindal, R C; Kar, Soumitra

    2017-09-01

    Mixed-matrix membranes (MMMs) were developed by impregnating organofunctionalized nanoadditives within fouling-susceptible polysulfone matrix following the non-solvent induced phase separation (NIPS) method. The facile functionalization of nanoparticles of anatase TiO 2 (nano-TiO 2 ) by using two different organoligands, viz . Tiron and chromotropic acid, was carried out to obtain organofunctionalized nanoadditives, F T -nano-TiO 2 and F C -nano-TiO 2 , respectively. The structural features of nanoadditives were evaluated by X-ray diffraction, X-ray photoelectron spectroscopy, Raman and Fourier transform infrared spectroscopy, which established that Tiron leads to the blending of chelating and bridging bidentate geometries for F T -nano-TiO 2 , whereas chromotropic acid produces bridging bidentate as well as monodentate geometries for F C -nano-TiO 2 . The surface chemistry of the studied membranes, polysulfone (Psf): F T -nano-TiO 2 UF and Psf: F C -nano-TiO 2 UF, was profoundly influenced by the benign distributions of the nanoadditives enriched with distinctly charged sites ([Formula: see text]), as evidenced by superior morphology, improved topography, enhanced surface hydrophilicity and altered electrokinetic features. The membranes exhibited enhanced solvent throughputs, viz . 3500-4000 and 3400-4300 LMD at 1 bar of transmembrane pressure, without significant compromise in their rejection attributes. The flux recovery ratios and fouling resistive behaviours of MMMs towards bovine serum albumin indicated that the nanoadditives could impart stable and appreciable antifouling activity, potentially aiding in a sustainable ultrafiltration performance.

  2. Three-Dimensional Graphene Matrix-Supported and Thylakoid Membrane-Based High-Performance Bioelectrochemical Solar Cell

    DEFF Research Database (Denmark)

    Pankratova, Galina; Pankratov, Dmitrii; Di Bari, Chiara

    2018-01-01

    A combination of thylakoid membranes (TMs) as photobiocatalysts with high-surface-area electroactive materials could hold great potential for sustainable “green” solar energy conversion. We have studied the orientated immobilization of TMs on high-surface-area graphene electrodes, which were...

  3. Molecular aspects of the interaction between MasonPfizer monkey virus matrix protein and artificial phospholipid membrane

    Czech Academy of Sciences Publication Activity Database

    Junková, P.; Prchal, J.; Spiwok, V.; Pleskot, Roman; Kadlec, J.; Krásný, Libor; Hynek, R.; Hrabal, R.; Ruml, T.

    2016-01-01

    Roč. 84, č. 11 (2016), s. 1717-1727 ISSN 0887-3585 Institutional support: RVO:61389030 ; RVO:61388971 Keywords : d-type retrovirus * force-field * nucleotide-sequence * myristate exposure * plasma-membrane * rhesus monkey Subject RIV: EB - Genetics ; Molecular Biology; EE - Microbiology, Virology (MBU-M) Impact factor: 2.289, year: 2016

  4. Molecular aspects of the interaction between Mason-Pfizer monkey virus matrix protein and artificial phospholipid membrane

    Czech Academy of Sciences Publication Activity Database

    Junková, P.; Prchal, J.; Spiwok, V.; Pleskot, Roman; Kadlec, Jan; Krásný, L.; Hynek, R.; Hrabal, R.; Ruml, T.

    2016-01-01

    Roč. 84, č. 11 (2016), s. 1717-1727 ISSN 0887-3585 Institutional support: RVO:61388963 Keywords : covalent labelling * mass spectrometry * multiscale molecular dynamics * protein-membrane interaction * phosphatidylinositol-(4,5)-bisphosphate * liposomes Subject RIV: CE - Biochemistry Impact factor: 2.289, year: 2016

  5. Membrane electrodes for the determination of pyridostigmine bromide.

    Science.gov (United States)

    El-Kosasy, Amira M; Salem, Maissa Y; El-Bardicy, Mohamed G; Abd El-Rahman, Mohamed K

    2009-01-01

    Two pyridostigmine bromide (PB) selective electrodes were investigated with 2-nitrophenyl octyl ether as a plasticizer in a polymeric matrix of carboxylated polyvinyl chloride (PVC-COOH), based on the interaction between the drug solution and the dissociated COOH groups in the PVC-COOH. One of the sensors was fabricated by using PVC-COOH only as anionic site without incorporation of an ionophore (sensor 1). The second sensor was constructed by using 2-hydroxy propyl beta-cyclodextrin as an ionophore (sensor 2). Linear responses of PB within a concentration range of 10(-3)-10(-2) and 10(-5)-10(-2) M, with slopes of 51.9 +/- 0.31 and 56.7 +/- 0.40 mV/decade over pH range of 5-10 were obtained using sensors 2 and 1, respectively. The proposed method displayed useful analytical characteristics for determination of PB in tablets with average recoveries of 100.22 +/- 0.62, and 100.15 +/- 0.72, and in plasma with average recoveries of 99.14 +/- 1.19 and 99.79 +/- 0.72, for sensors 2 and 1, respectively. The utility of 2-hydroxy propyl beta-cyclodextrin as an ionophore has a significant influence on increasing both membrane sensitivity and selectivity of sensor 2 in comparison with sensor 1. The methods were also used to determine the intact drug in the presence of its degradate, and thus could be used as stability-indicating methods. The results obtained by the proposed procedures were statistically analyzed and compared with those obtained by the U.S. Pharmacopeia method. No significant difference for either accuracy or precision was observed.

  6. Processing of nanocomposites EVA/PVC/MMT in twin-screw extruder

    International Nuclear Information System (INIS)

    Gehlen, A.; Barbutti Filho, W.R.; Francisquetti, E.L.; Andrade, M.Z.; Zattera, A.J.

    2010-01-01

    Polymeric nanocomposites have some superior properties when compared to conventional polymer composites and is one of the most promising fields in the nanotechnology research. In a EVA (ethylene vinyl acetate) /PVC (poly vinyl chloride) matrix was incorporated different types of montmorillonite clays (an inorganic (Na + ) and two organic modified (15A and 30B nanoclays). The mixtures were processed in a co-rotating twin-screw extruder at processing speeds of 200 and 400 rpm. Thermogravimetric analysis (TGA) shown that the inorganic and organic modified clays promoted a shift to higher temperatures in the degradation temperature., X-ray diffraction (XRD) and transmission electronic microscopy (TEM) shows a possible intercalation with the 15A clay, exfoliation with the 30B clay and formation of clusters in the Na + clay. For all clays studied, the increase in shear rate does not promote significant changes. (author)

  7. Self-Plasticization of PVC via click reaction of a monooctyl phthalate derivative

    Directory of Open Access Journals (Sweden)

    Jia Puyou

    2017-09-01

    Full Text Available Modified PVC (M-PVC material with suppressed migration and low glass transition temperature was prepared via click reaction of a monooctyl phthalate derivative. Chemical structure and composition of M-PVC were characterized by FT-IR, 1H NMR and element analysis. Thermal stability, glass transition temperature and migration stability of M-PVC were studied with TGA, DSC and migration tests, respectively. The study showed that M-PVC exhibited poor thermal stability, and low glass transition temperature of 66.0°C. No migration was found in distilled water, 10% (v/v ethanol, 30% (w/vacetic acid and petroleum ether. The PVC material is expected to preparing PVC products in the areas with high migration resistance requirement.

  8. Selective flotation of PVC using gelatin and lignin alkali.

    Science.gov (United States)

    Yenial, Unzile; Kangal, Olgaç; Güney, Ali

    2013-06-01

    Recycling has become one of the most important issues as a result of increasing waste mass in present day. This is especially important for polymer wastes as they are hard to degenerate in nature. Today, most of the practical methods used for the recycling of waste mass, such as hand sorting, gravity separation, etc., cannot be performed successfully owing to close densities of polymers. Froth flotation can be used successfully and economically for this purpose. The main objective of this study was to investigate the effect of plasticizer reagents and the success of froth flotation at plastic recycling. In this study, lignin alkali and gelatin were used as plasticizer reagents. The effect of these reagents was searched with the parameters of pH, concentration, conditioning and flotation time. In the case of post-consumed polyethylene terephthalate and polyvinyl chloride (PVC), 98.9% purity of PVC was obtained at optimum conditions.

  9. Experimental Investigations on Combustion Behaviors of Live PVC Cables

    Science.gov (United States)

    Wang, Liufang; Zhang, Jiaqing; Zhang, Bosi; Liu, Min; Fan, Minghao; Li, Qiang

    2018-03-01

    This paper investigated the combustion behaviors of live PVC cables with overload currents experimentally. The smoke coefficient of released smoke and the released gas concentration were examined. The results indicate that the combustion of live PVC cables can be divided into four stages, i.e., core exposed with a little smoke, obvious flame, maximum smoke and smoke depress. For most cases, using blue laser is better than using rad laser, since the extinction coefficient of the rad laser was larger than that of the blue laser. The response time of the detection of the released typical gases due to cable pyrolysis decreased and the peak values of the typical gases increased with the overload currents. In addition, the time to reach the peak value of gas concentration also decreased with the overload currents.

  10. Study on the interactions PVC/plasticizers by NMR

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Maria I.B.; Monteiro, Elisabeth E.C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas; Harris, Robin [Durham Univ. (United Kingdom). Dept. of Chemistry

    1992-12-31

    The nature of the interactions between PVC and plasticizers as di-butyl phthalate and di-2-ethyl-hexyl phthalate can be investigated using proton/carbon-13 NMR techniques. The measurements of T{sub 1} for protons and carbon-13 and T{sub 1} P for protons can provide a good source of information about the complex behaviour for those two systems which were investigated. (author) 14 refs., 5 figs., 1 tab.

  11. Tetracaine – selective electrodes with polymer membranes and their application in pharmaceutical formulation control

    Directory of Open Access Journals (Sweden)

    Ahmed Khudhair Hassan

    2017-02-01

    Full Text Available The construction and electrochemical response characteristics of poly(vinyl chloride (PVC membrane electrodes for tetracaine hydrochloride (TCH are described. The sensing membranes incorporating ion-association complexes of tetracaine cation with phosphotungstic acid (PTA or phosphomolybdic acid (PMA or Sodium tetraphenyl borate (NaTPB as electroactive materials and di-n-butyl phthalate (DBPH or tri-n-butyl phosphate (TBP as a plasticizer in PVC matrixes were evaluated. The results obtained show the electrodes based on PTA or PMA as electroactive compounds and DBPH as plasticizer with a fast, stable and near-Nernstian response over a wide concentration range (1 × 10−5–5 × 10−2 M, with cationic slopes of 55.02 and 52.05 mV decade−1 over a pH range of (2.5–6.5. The electrodes show good discrimination of tetracaine from several inorganic cations and sugars. The electrodes were successfully applied for the determination of tetracaine in pharmaceutical formulations.

  12. Strength analysis of welded corners of PVC window profiles

    Science.gov (United States)

    Postawa, P.; Stachowiak, T.; Gnatowski, A.

    2017-08-01

    The article presents the results of researches which main purpose was to define the influence of welding parameters on strength of welded corners of PVC window profile. PVC profiles of a branded name GENEO® produced by Rehau Company were used for this research. The profiles were made by using a co-extrusion method. The surface of the profile was made of PVC mixture with no additives. Its main task was to get a smooth surface resistant to a smudge. The use of an unfilled polyester provides an aesthetic look and improves the resistance of extrudate to water getting into inner layers. The profile's inner layers have been filled up with glass fibre in order to improve its stiffness and mechanical properties. Window frames with cut corners used for this research, were produced on technological line of EUROCOLOR Company based in Pyskowice (Poland). The main goal of this analysis was to evaluate the influence of the main welding parameter (temperature upsetting) on hardness of welds we received in whole process. A universal testing machine was used for the research.

  13. Effective enhancement of gas separation performance in mixed matrix membranes using core/shell structured multi-walled carbon nanotube/graphene oxide nanoribbons

    Science.gov (United States)

    Xue, Qingzhong; Pan, Xinglong; Li, Xiaofang; Zhang, Jianqiang; Guo, Qikai

    2017-02-01

    Novel core/shell structured multi-walled carbon nanotube/graphene oxide nanoribbons (MWCNT@GONRs) nanohybrids were successfully prepared using a modified chemical longitudinal unzipping method. Subsequently, the MWCNT@GONRs nanohybrids were used as fillers to enhance the gas separation performance of polyimide based mixed matrix membranes (MMMs). It is found that MMMs concurrently exhibited higher gas selectivity and higher gas permeability compared to pristine polyimide. The high gas selectivity could be attributed to the GONRs shell, which provided a selective barrier and large gas adsorbed area, while the high gas permeability resulted from the hollow structured MWCNTs core with smooth internal surface, which acted as a rapid transport channel. MWCNT@GONRs could be promising candidates to improve gas separation performance of MMMs due to the unique microstructures, ease of synthesis and low filling loading.

  14. Overexpression of membrane sialic acid-specific sialidase Neu3 inhibits matrix metalloproteinase-9 expression in vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Moon, Sung-Kwon; Cho, Seung-Hak; Kim, Kyung-Woon; Jeon, Jae Heung; Ko, Jeong-Heon; Kim, Bo Yeon; Kim, Cheorl-Ho

    2007-01-01

    The ganglioside-specific sialidase Neu3 has been suggested to participate in cell growth, migration, and differentiation. Recent reports suggest that sialidase may be involved in intimal thickening, an early stage in the development of atherosclerosis. However, the role of the Neu3 gene in vascular smooth muscle cells (VSMC) responses has not yet been elucidated. To determine whether a Neu3 is able to modulate VSMC growth, the effect of overexpression of the Neu3 gene on cell proliferation was examined. However, the results show that the overexpression of this gene has no effect on DNA synthesis and ERK phosphorylation in cultured VSMC in the presence of TNF-α. Because atherogenic effects need not be limited to proliferation, we decided to examine whether Neu3 exerted inhibitory effects on matrix metalloproteinase-9 (MMP-9) activity in TNF-α-induced VSMC. The expression of the Neu3 gene led to the inhibition of TNF-α-induced matrix metalloproteinase-9 (MMP-9) expression in VSMC as determined by zymography and immunoblot. Furthermore, Neu3 gene expression strongly decreased MMP-9 promoter activity in response to TNF-α. This inhibition was characterized by the down-regulation of MMP-9, which was transcriptionally regulated at NF-κB and activation protein-1 (AP-1) sites in the MMP-9 promoter. These findings suggest that the Neu3 gene represents a physiological modulator of VSMC responses that may contribute to plaque instability in atherosclerosis

  15. Revisiting the Aluminum Trimesate-based MOF (MIL-96): from Structure Determination to the Processing of Mixed Matrix Membranes for CO2 Capture.

    KAUST Repository

    Benzaqui, Marvin; S. Pillai, Renjith; Sabetghadam, Anahid; Benoit, Virginie; Normand, Pé rine; Marrot, Jerome; Menguy, Nicolas; Montero, David; Shepard, William; Tissot, Antoine; Martineau-Corcos, Charlotte; Sicard, Clé mence; Mihaylov, Mihail; Carn, Florent; Beurroeis, Isabelle; Llewellyn, Philip L.; De Weireld, Guy; Hadjiivanov, Konstantin; Gascon, Jorge; Kapteijn, Freek; Maurin, Guillaume; Steunou, Nathalie; Serre, Christian

    2017-01-01

    A microporous Al trimesate-based metal-organic framework (MOF), denoted MIL-96-(Al), was selected as a porous hybrid filler for the processing of mixed matrix membranes (MMMs) for CO2/N-2 postcombustion separation. First, the structural model of MIL-96-(Al) initially reported was revisited using a combination of synchrotron-based single-crystal X-ray diffraction, solid-state nuclear magnetic resonance spectroscopy, and density functional theory (DFT) calculations. In a second step, pure MIL-96-(Al) crystals differing by their size and aspect ratio, including anisotropic hexagonal platelets and nanoparticles of about 70 nm in diameter, were prepared. Then, a combination of in situ IR spectroscopy, single-gas, and CO2/N-2 coadsorption experiments, calorimetry, and molecular simulations revealed that MIL-96-(Al) nanoparticles show a relatively high CO2 affinity over N-2 owing to strong interactions between CO2 molecules and several adsorption sites such as Al3+ Lewis centers, coordinated water, and hydroxyl groups. Finally, the high compatibility between MIL-96-(Al) nanoparticles and the 6FDA-DAM polymer allowed the processing of homogeneous and defect-free MMMs with a high MOF loading (up to 25 wt %) that outperform pure polymer membranes for CO2/N-2 separation.

  16. The role of tetragonal-metal-organic framework-5 loadings with extra ZnO molecule on the gas separation performance of mixed matrix membrane

    International Nuclear Information System (INIS)

    Arjmandi, Mehrzad; Pakizeh, Majid; Pirouzram, Omid

    2015-01-01

    The effect of more ZnO molecule in tetragonal structure of MOF-5 than cubic structure on the gas permeation properties of T-MOF-5/polyetherimide mixed matrix membranes was investigated. T-MOF-5 was first successfully synthesized and carefully characterized by XRD, FTIR, SEM and N 2 adsorption technique at 77 K. Novel T-MOF-5/PEI MMMs were prepared using solution casting method and characterized by FTIR and SEM. The SEM pictures of the MMMs showed that T-MOF-5 nanocrystals changed the morphology of PEI and exhibited acceptable contacts between the filler particles and the polymer chains. Gas permeation properties of these membranes with different T-MOF-5 contents were studied for pure H 2 , CO 2 , CH 4 and N 2 gases. Permeation measurement showed that the all gases' permeability, diffusivity and solubility were increased with T-MOF-5 loading. H 2 permeability and the ideal selectivity of H 2 /CO 2 and H 2 /CH 4 in MMM with 25 wt% loading of T-MOF-5 nanocrystals were increased. This behavior was attributed to more ZnO molecule in T-MOF-5 structure. The experimental gas permeations through T-MOF-5/PEI nanocomposite with different filler loadings were fitted on Higuchi model. Good agreement between the experimental data and the predicted gas permeability was obtained

  17. The role of tetragonal-metal-organic framework-5 loadings with extra ZnO molecule on the gas separation performance of mixed matrix membrane

    Energy Technology Data Exchange (ETDEWEB)

    Arjmandi, Mehrzad; Pakizeh, Majid [Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Pirouzram, Omid [Kurdistan University, Kurdistan (Iran, Islamic Republic of)

    2015-06-15

    The effect of more ZnO molecule in tetragonal structure of MOF-5 than cubic structure on the gas permeation properties of T-MOF-5/polyetherimide mixed matrix membranes was investigated. T-MOF-5 was first successfully synthesized and carefully characterized by XRD, FTIR, SEM and N{sub 2} adsorption technique at 77 K. Novel T-MOF-5/PEI MMMs were prepared using solution casting method and characterized by FTIR and SEM. The SEM pictures of the MMMs showed that T-MOF-5 nanocrystals changed the morphology of PEI and exhibited acceptable contacts between the filler particles and the polymer chains. Gas permeation properties of these membranes with different T-MOF-5 contents were studied for pure H{sub 2}, CO{sub 2}, CH{sub 4} and N{sub 2} gases. Permeation measurement showed that the all gases' permeability, diffusivity and solubility were increased with T-MOF-5 loading. H{sub 2} permeability and the ideal selectivity of H{sub 2}/CO{sub 2} and H{sub 2}/CH{sub 4} in MMM with 25 wt% loading of T-MOF-5 nanocrystals were increased. This behavior was attributed to more ZnO molecule in T-MOF-5 structure. The experimental gas permeations through T-MOF-5/PEI nanocomposite with different filler loadings were fitted on Higuchi model. Good agreement between the experimental data and the predicted gas permeability was obtained.

  18. Progesterone receptor membrane component 1 as the mediator of the inhibitory effect of progestins on cytokine-induced matrix metalloproteinase 9 activity in vitro.

    Science.gov (United States)

    Allen, Terrence K; Feng, Liping; Grotegut, Chad A; Murtha, Amy P

    2014-02-01

    Progesterone (P4) and the progestin, 17α-hydroxyprogesterone caproate, are clinically used to prevent preterm births (PTBs); however, their mechanism of action remains unclear. Cytokine-induced matrix metalloproteinase 9 (MMP-9) activity plays a key role in preterm premature rupture of the membranes and PTB. We demonstrated that the primary chorion cells and the HTR8/SVneo cells (cytotrophoblast cell line) do not express the classical progesterone receptor (PGR) but instead a novel progesterone receptor, progesterone receptor membrane component 1 (PGRMC1), whose role remains unclear. Using HTR8/SVneo cells in culture, we further demonstrated that 6 hours pretreatment with medroxyprogesterone acetate (MPA) and dexamethasone (Dex) but not P4 or 17α-hydroxyprogesterone hexanoate significantly attenuated tumor necrosis factor α-induced MMP-9 activity after a 24-hour incubation period. The inhibitory effect of MPA, but not Dex, was attenuated when PGRMC1 expression was successfully reduced by PGRMC1 small interfering RNA. Our findings highlight a possible novel role of PGRMC1 in mediating the effects of MPA and in modulating cytokine-induced MMP-9 activity in cytotrophoblast cells in vitro.

  19. Extracellular Matrix (ECM) Multilayer Membrane as a Sustained Releasing Growth Factor Delivery System for rhTGF-β3 in Articular Cartilage Repair

    Science.gov (United States)

    Park, Sang-Hyug; Kim, Moon Suk; Kim, Young Jick; Choi, Byung Hyune; Lee, Chun Tek; Park, So Ra; Min, Byoung-Hyun

    2016-01-01

    Recombinant human transforming growth factor beta-3 (rhTGF-β3) is a key regulator of chondrogenesis in stem cells and cartilage formation. We have developed a novel drug delivery system that continuously releases rhTGF-β3 using a multilayered extracellular matrix (ECM) membrane. We hypothesize that the sustained release of rhTGF-β3 could activate stem cells and result in enhanced repair of cartilage defects. The properties and efficacy of the ECM multilayer-based delivery system (EMLDS) are investigated using rhTGF-β3 as a candidate drug. The bioactivity of the released rhTGF-ß3 was evaluated through chondrogenic differentiation of mesenchymal stem cells (MSCs) using western blot and circular dichroism (CD) analyses in vitro. The cartilage reparability was evaluated through implanting EMLDS with endogenous and exogenous MSC in both in vivo and ex vivo models, respectively. In the results, the sustained release of rhTGF-ß3 was clearly observed over a prolonged period of time in vitro and the released rhTGF-β3 maintained its structural stability and biological activity. Successful cartilage repair was also demonstrated when rabbit MSCs were treated with rhTGF-β3-loaded EMLDS ((+) rhTGF-β3 EMLDS) in an in vivo model and when rabbit chondrocytes and MSCs were treated in ex vivo models. Therefore, the multilayer ECM membrane could be a useful drug delivery system for cartilage repair. PMID:27258120

  20. Extracellular Matrix (ECM Multilayer Membrane as a Sustained Releasing Growth Factor Delivery System for rhTGF-β3 in Articular Cartilage Repair.

    Directory of Open Access Journals (Sweden)

    Soon Sim Yang

    Full Text Available Recombinant human transforming growth factor beta-3 (rhTGF-β3 is a key regulator of chondrogenesis in stem cells and cartilage formation. We have developed a novel drug delivery system that continuously releases rhTGF-β3 using a multilayered extracellular matrix (ECM membrane. We hypothesize that the sustained release of rhTGF-β3 could activate stem cells and result in enhanced repair of cartilage defects. The properties and efficacy of the ECM multilayer-based delivery system (EMLDS are investigated using rhTGF-β3 as a candidate drug. The bioactivity of the released rhTGF-ß3 was evaluated through chondrogenic differentiation of mesenchymal stem cells (MSCs using western blot and circular dichroism (CD analyses in vitro. The cartilage reparability was evaluated through implanting EMLDS with endogenous and exogenous MSC in both in vivo and ex vivo models, respectively. In the results, the sustained release of rhTGF-ß3 was clearly observed over a prolonged period of time in vitro and the released rhTGF-β3 maintained its structural stability and biological activity. Successful cartilage repair was also demonstrated when rabbit MSCs were treated with rhTGF-β3-loaded EMLDS ((+ rhTGF-β3 EMLDS in an in vivo model and when rabbit chondrocytes and MSCs were treated in ex vivo models. Therefore, the multilayer ECM membrane could be a useful drug delivery system for cartilage repair.

  1. Revisiting the Aluminum Trimesate-based MOF (MIL-96): from Structure Determination to the Processing of Mixed Matrix Membranes for CO2 Capture.

    KAUST Repository

    Benzaqui, Marvin

    2017-11-08

    A microporous Al trimesate-based metal-organic framework (MOF), denoted MIL-96-(Al), was selected as a porous hybrid filler for the processing of mixed matrix membranes (MMMs) for CO2/N-2 postcombustion separation. First, the structural model of MIL-96-(Al) initially reported was revisited using a combination of synchrotron-based single-crystal X-ray diffraction, solid-state nuclear magnetic resonance spectroscopy, and density functional theory (DFT) calculations. In a second step, pure MIL-96-(Al) crystals differing by their size and aspect ratio, including anisotropic hexagonal platelets and nanoparticles of about 70 nm in diameter, were prepared. Then, a combination of in situ IR spectroscopy, single-gas, and CO2/N-2 coadsorption experiments, calorimetry, and molecular simulations revealed that MIL-96-(Al) nanoparticles show a relatively high CO2 affinity over N-2 owing to strong interactions between CO2 molecules and several adsorption sites such as Al3+ Lewis centers, coordinated water, and hydroxyl groups. Finally, the high compatibility between MIL-96-(Al) nanoparticles and the 6FDA-DAM polymer allowed the processing of homogeneous and defect-free MMMs with a high MOF loading (up to 25 wt %) that outperform pure polymer membranes for CO2/N-2 separation.

  2. Gas transport behavior of mixed-matrix membranes composed of silica nanoparticles in a polymer of intrinsic microporosity (PIM-1)

    KAUST Repository

    Ahn, Juhyeon; Chung, Wookjin; Pinnau, Ingo; Song, Jingshe; Du, Naiying; Robertson, Gilles P.; Guiver, Michael D.

    2010-01-01

    Recently, high-free volume, glassy ladder-type polymers, referred to as polymers of intrinsic microporosity (PIM), have been developed and their reported gas transport performance exceeded the Robeson upper bound trade-off for O2/N2 and CO2/CH4. The present work reports the gas transport behavior of PIM-1/silica nanocomposite membranes. The changes in free volume, as well as the presence and volume of the void cavities, were investigated by analyzing the density, thermal stability, and nano-structural morphology. The enhancement in gas permeability (e.g., He, H2, O2, N2, and CO2) with increasing filler content shows that the trend is related to the true silica volume and void volume fraction. Crown Copyright © 2009.

  3. Developmental expression of membrane type 4-matrix metalloproteinase (Mt4-mmp/Mmp17) in the mouse embryo

    Science.gov (United States)

    Clemente, Cristina; Montalvo, María Gregoria; Seiki, Motoharu; Arroyo, Alicia G.

    2017-01-01

    Matrix metalloproteinases (MMPs) constitute a large group of endoproteases that play important functions during embryonic development, tumor metastasis and angiogenesis by degrading components of the extracellular matrix. Within this family, we focused our study on Mt4-mmp (also called Mmp17) that belongs to a distinct subset that is anchored to the cell surface via a glycosylphosphatidylinositol (GPI) moiety and with the catalytic site exposed to the extracellular space. Information about its function and substrates is very limited to date, and little has been reported on its role in the developing embryo. Here, we report a detailed expression analysis of Mt4-mmp during mouse embryonic development by using a LacZ reporter transgenic mouse line. We showed that Mt4-mmp is detected from early stages of development to postnatal stages following a dynamic and restricted pattern of expression. Mt4-mmp was first detected at E8.5 limited to the intersomitic vascularization, the endocardial endothelium and the dorsal aorta. Mt4-mmpLacZ/+ cells were also observed in the neural crest cells, somites, floor plate and notochord at early stages. From E10.5, expression localized in the limb buds and persists during limb development. A strong expression in the brain begins at E12.5 and continues to postnatal stages. Specifically, staining was observed in the olfactory bulb, cerebral cortex, hippocampus, striatum, septum, dorsal thalamus and the spinal cord. In addition, LacZ-positive cells were also detected during eye development, initially at the hyaloid artery and later on located in the lens and the neural retina. Mt4-mmp expression was confirmed by quantitative RT-PCR and western blot analysis in some embryonic tissues. Our data point to distinct functions for this metalloproteinase during embryonic development, particularly during brain formation, angiogenesis and limb development. PMID:28926609

  4. Reduced adhesion of Staphylococcus aureus to ZnO/PVC nanocomposites

    Directory of Open Access Journals (Sweden)

    Geilich BM

    2013-03-01

    Full Text Available Benjamin M Geilich,1 Thomas J Webster21Program in Bioengineering, 2Department of Chemical Engineering, College of Engineering, Northeastern University, Boston, MA, USAAbstract: In hospitals and clinics worldwide, medical device surfaces have become a rapidly growing source of nosocomial infections. In particular, patients requiring mechanical ventilation (and, thus, intubation with an endotracheal tube for extended lengths of time are faced with a high probability of contracting ventilator-associated pneumonia. Once inserted into the body, the endotracheal tube provides a surface to which bacteria can adhere and form a biofilm (a robust, sticky matrix that provides protection against the host immune system and antibiotic treatment. Adding to the severity of this problem is the spread of bacterial genetic tolerance to antibiotics, in part demonstrated by the recent and significant increase in the prevalence of methicillin-resistant Staphylococcus aureus. To combat these trends, different techniques in biomaterial design must be explored. Recent research has shown that nanomaterials (materials with at least one dimension less than 100 nm may have the potential to prevent or disrupt bacterial processes that lead to infections. In this study, polyvinyl chloride (PVC taken from a conventional endotracheal tube was embedded with varying concentrations of zinc oxide (ZnO nanoparticles. S. aureus biofilms were then grown on these nanocomposite surfaces during a 24-hour culture. Following this, biofilms were removed from the surfaces and the number of colony forming units present was assessed. Bacterial proliferation on the samples embedded with the highest concentration of ZnO nanoparticles was 87% less when compared to the control, indicating that this technique is effective at reducing biofilm formation on PVC surfaces without the use of antibiotics.Keywords: nanomaterials, endotracheal tube, biofilm, zinc oxide, nanoparticles, Staphylococcus aureus

  5. Model-based performance and energy analyses of reverse osmosis to reuse wastewater in a PVC production site.

    Science.gov (United States)

    Hu, Kang; Fiedler, Thorsten; Blanco, Laura; Geissen, Sven-Uwe; Zander, Simon; Prieto, David; Blanco, Angeles; Negro, Carlos; Swinnen, Nathalie

    2017-11-10

    A pilot-scale reverse osmosis (RO) followed behind a membrane bioreactor (MBR) was developed for the desalination to reuse wastewater in a PVC production site. The solution-diffusion-film model (SDFM) based on the solution-diffusion model (SDM) and the film theory was proposed to describe rejections of electrolyte mixtures in the MBR effluent which consists of dominant ions (Na + and Cl - ) and several trace ions (Ca 2+ , Mg 2+ , K + and SO 4 2- ). The universal global optimisation method was used to estimate the ion permeability coefficients (B) and mass transfer coefficients (K) in SDFM. Then, the membrane performance was evaluated based on the estimated parameters which demonstrated that the theoretical simulations were in line with the experimental results for the dominant ions. Moreover, an energy analysis model with the consideration of limitation imposed by the thermodynamic restriction was proposed to analyse the specific energy consumption of the pilot-scale RO system in various scenarios.

  6. Studies in cross-linking PVC footwear soling compounds using gamma-irradiation

    International Nuclear Information System (INIS)

    Bloom, L.I.

    1983-01-01

    Irradiation cross-linking of polymeric materials has been known for some time, but it is only in recent years that it has been put to commercial advantage. Well known uses are the modification of PVC for higher temperature applications. Fundamental studies were carried out on amongst other materials, plasticised PVC compounds for use in cable applications. The results of this work, encouraged the author to investigate cross-linkable PVC in areas such as footwear soling

  7. Sonochemical synthesis of cooper II sulfide nanoparticles and their use as radiolytic stabilizer in polyvinyl chloride matrix

    International Nuclear Information System (INIS)

    Freitas, Danubia Maria da Silva; Lima, Thaysa Araujo de; Aquino, Katia Aparecida da Silva; Araujo, Elmo S.

    2013-01-01

    Cooper (II) sulfide (CuS) was synthesized by sonochemical method. CuS crystals with hexagonal structure exhibit irregular aggregates of particles with an average size in the range of 250-900 nm. Commercial Polyvinyl chloride (PVC) containing CuS nanoparticles (PVC/CuS) at concentrations of 0.10; 0.30; 0.50 and 0.70 wt% were investigated. The samples were irradiated with gamma radiation ( 60 Co) at room temperature and air atmosphere. The viscosity-average molar mass (M v ) was measured for PVC systems without nanoparticles and with nanoparticles. Decrease in viscosity molar mass was observed when the systems were gamma irradiated reflect the random scission effects that take place in the main chain. Degradation index (DI) value was also obtained by viscosity analysis. DI results showed that the addition of CuS nanoparticles at 0.5 wt% into PVC matrix decreased the number of main chain scissions at dose of 25 kGy and was calculated a protection of 84% in PVC matrix. CuS nanoparticles act as free radical scavenger into gamma-irradiated PVC systems. The interactions between CuS and PVC favor action of nanoparticles as a good plasticizer in the PVC molecule. (author)

  8. Quality control in the recycling stream of PVC from window frames by hyperspectral imaging

    Science.gov (United States)

    Luciani, Valentina; Serranti, Silvia; Bonifazi, Giuseppe; Di Maio, Francesco; Rem, Peter

    2013-05-01

    Polyvinyl chloride (PVC) is one of the most commonly used thermoplastic materials in respect to the worldwide polymer consumption. PVC is mainly used in the building and construction sector, products such as pipes, window frames, cable insulation, floors, coverings, roofing sheets, etc. are realised utilising this material. In recent years, the problem of PVC waste disposal gained increasing importance in the public discussion. The quantity of used PVC items entering the waste stream is gradually increased as progressively greater numbers of PVC products approach to the end of their useful economic lives. The quality of the recycled PVC depends on the characteristics of the recycling process and the quality of the input waste. Not all PVC-containing waste streams have the same economic value. A transparent relation between value and composition is required to decide if the recycling process is cost effective for a particular waste stream. An objective and reliable quality control technique is needed in the recycling industry for the monitoring of both recycled flow streams and final products in the plant. In this work hyperspectral imaging technique in the near infrared (NIR) range (1000-1700 nm) was applied to identify unwanted plastic contaminants and rubber present in PVC coming from windows frame waste in order to assess a quality control procedure during its recycling process. Results showed as PVC, PE and rubber can be identified adopting the NIR-HSI approach.

  9. Deterioration of plasticized PVC components in Apollo spacesuits

    DEFF Research Database (Denmark)

    Shashoua, Yvonne; Schnell, Ulrich; Young, Lisa

    2002-01-01

    Spacesuits from the Apollo era are unique in their history, materials and construction. This project involved the first detailed examination of the condition of the spacesuits since their acquisition by the National Air and Space Museum in the 1970s. Plasticized polyvinyl chloride (PVC) tubing...... in the Life Support System, used to transport air and water to the astronaut, and in the Liquid Cooling Garment, used to cool the wearer of the spacesuit, exhibited high levels of deterioration. Tubing was unacceptably discoloured, tacky to the touch and surfaces were obscured by crystals. Visual examination...

  10. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jurgen

    2013-10-31

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  11. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jü rgen; Khashab, Niveen M.; Zaher, Amir

    2013-01-01

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  12. Analysis of Adipate Ester Contents in PVC Plastics

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2006-01-01

    Plasticizers are needed in flexible PVC (PolyVinylChloride) products. There is serious concern that commonly used phthalate esters may harm life reproduction systems. To avoid the problems, instead adipate di-esters (AEs) of C8 to C10 alcohols are used as higher prized alternatives; e.g. di-2......-ethylhexyl adipate or DEHA [103-23-1], also known as Adimoll® or di-octyl adipate, DOA, see Fig. 1. A widely used plasticizer in food (cling) films is DEHA, often in combination with polymers, epoxidized soya-bean oil, etcetera. DEHA also occurs in children toys. We have previously shown that the presence...... of phthalate esters in PVC can be rapidly analyzed by Fourier transform (FT-) Raman spectroscopy excited with a 1064 nm laser. Here in this project we report a similar study. The aim was to find out whether FT-Raman spectroscopy can be used to determine the presence of adipate esters (AEs) as plasticizers...

  13. Penelitian penggunaan minarex sebagai plasticizer untuk pembuatan kompon slang PVC

    Directory of Open Access Journals (Sweden)

    Niken Karsiati

    1995-12-01

    Full Text Available The objective of the research is to find out the maximum quantity of Minarex as plasticizer which can be added in making compound PVC hose which fulfills the requirements of JIS K. 6771-77 “Flexible Vinyl Tube. Materials used are PVC resin added by additives, i.e DOP, BaCdZn, Stearic Acid, dyes and Minarex as DOP substitution. They all must be mixed and feed to two roll mill homogenizing. Temperature of operational is within 50-800C, roll speed is approximately 10 and 8,6 rpm. Then the compound is moulded into slab form using hydraulic press machine at 1700C, pressure 150 kg/cm2for 10 minutes. The slab is tested its physical properties including tensile strength, elongation at break, tensile strength after accelerated aging, and also observed organoleptically. Based on the research, compound with Minarex substitution 10 parts still conform to JIS K. 6771-77 and the appearance is good.

  14. Development of a continuous flow model system for studies of biofilm formation on polymers and its application on PVC-C and PVC-P

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Albrechtsen, Hans-Jørgen

    could be harvested from three different combinations of flow velocity and residence time. Biofilm formation was followed by ATP analysis on test material (chlorinated polyvinylchloride, PVC-C), negative control (stainless steel) and positive control (plasticized polyvinylchloride, PVC-P) incubated......-C, while most of the very deviating values for PVC-P were between 2-13,000 pg ATP/cm2. During 43 weeks of operation of the continuous flow model systems the biofilm formation increased on all three materials, with biofilm formation on PVC-C at the same level as on the negative steel control (values of 75...... system. In this study, a continuous flow model system was developed, for investigating biofilm formation on polymers, simulating conditions in the distribution system. Commercially available pipes were used for exchangeable test pieces, which allowed for testing over prolonged time periods. Test pieces...

  15. Fittings of unplasticized polyvinyl chloride (PVC-U), chlorinated polyvinyl chloride (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Dimensions of sockets - Metric series

    CERN Document Server

    International Organization for Standardization. Geneva

    1985-01-01

    Fittings of unplasticized polyvinyl chloride (PVC-U), chlorinated polyvinyl chloride (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Dimensions of sockets - Metric series

  16. Plastics piping systems for industrial applications – Acrylonitrile-butadiene-styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) – Specifications for components and the system – Metric series

    CERN Document Server

    Deutsches Institut für Normung. Berlin

    2003-01-01

    Plastics piping systems for industrial applications – Acrylonitrile-butadiene-styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) – Specifications for components and the system – Metric series

  17. Plastics piping systems for industrial applications : acrylonitrile-butadiene- styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) : specifications for components and the system : metric series

    CERN Document Server

    International Organization for Standardization. Geneva

    2003-01-01

    Plastics piping systems for industrial applications : acrylonitrile-butadiene- styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) : specifications for components and the system : metric series

  18. Development and Characterization of Defect-Free Matrimid® Mixed-Matrix Membranes Containing Activated Carbon Particles for Gas Separation

    Directory of Open Access Journals (Sweden)

    Fynn Weigelt

    2018-01-01

    Full Text Available In this work, mixed-matrix membranes (MMMs for gas separation in the form of thick films were prepared via the combination of the polymer Matrimid® 5218 and activated carbons (AC. The AC particles had a mean particle size of 1.5 μm and a mean pore diameter of 1.9 nm. The films were prepared by slow solvent evaporation from casting solutions in chloroform, which had a varying polymer–AC ratio. It was possible to produce stable films with up to a content of 50 vol % of AC. Thorough characterization experiments were accomplished via differential scanning calorimetry and thermogravimetric analysis, while the morphology of the MMMs was also investigated via scanning electron microscopy. The gas transport properties were revealed by employing time-lag measurements for different pure gases as well as sorption balance experiments for the filler particles. It was found that defect free Matrimid® MMMs with AC were prepared and the increase of the filler content led to a higher effective permeability for different gases. The single gas selectivity αij of different gas pairs maintained stable values with the increase of AC content, regardless of the steep increase in the effective permeability of the pure gases. Estimation of the solubilities and the diffusivities of the Matrimid®, AC, and MMMs allowed for the explanation of the increasing permeabilities of the MMMs, with the increase of AC content by modelling.

  19. Membrane-Type 1 Matrix Metal loproteinase Is Regulated by Sp1 through the Differential Activation of AKT, JNK, and ERK Pathways in Human Prostate Tumor Cells

    Directory of Open Access Journals (Sweden)

    Isis C. Sroka

    2007-05-01

    Full Text Available We and other investigators have previously shown that membrane-type 1 matrix metalloproteinase (MT1-MMP is overexpressed in invasive prostate cancer cells. However, the mechanism for this expression is not known. Here, we show that MT1-MMP is minimally expressed in nonmalignant primary prostate cells, moderately expressed in DU-145 cells, and highly expressed in invasive PC-3 and PC-3N cells. Using human MT1-MMP promoter reporter plasmids and mobility shift assays, we show that Spi regulates MT1-MMP expression in DU-145, PC-3, and PC-3N cells and in PC3-N cells using chromatin immunoprecipitation analysis and silencing RNA. Investigation of signaling pathway showed that DU-145 cells express constitutively phosphorylated extracellular stress-regulated kinase (ERK, whereas PC-3 and PC-3N cells express constitutively phosphorylated AKT/PKB and c-Jun NH2 terminal kinase (JNK. We show that MT1-MMP and Spi levels are decreased in PC-3 and PC-3N cells when phosphatidylinositol-3 kinase and JNK are inhibited, and that MT1-MMP levels are decreased in DU-145 cells when MEK is inhibited. Transient transfection of PC-3 and PC-3N cells with a dominant-negative JNK or p85, and of DU-145 cells with a dominant negative ERK, reduces MT1-MMP promoter activity. These results indicate differential signaling control of Spi-mediated transcriptional regulation of MT1-MMP in prostate cancer cell lines.

  20. PVC Based Selective Sensors for Ni2+ Ions Using Carboxylated and Methylated Porphine

    Directory of Open Access Journals (Sweden)

    J. M. Bhatnagar

    2003-09-01

    Full Text Available Poly vinylchloride (PVC based membranes of 4,4',4'',4'''-21H,23H-porphine–5,10,15,20 –tetrayl tetrakis (benzoic acid (TBAP and 2,3,7,8,12,13,17,18-octamethyl - 21H, 23H-porphine (OMP were prepared using dibutyl phthalate (DBP, dioctylphthalate (DOP, dibutyl(butylphosphonate (DBBP and 1-chloronaphthalene (CN as plastcizing solvent mediators and sodium tetraphenylborate (NaTPB as an anion excluder for Ni2+ selective sensors. TBAP based membrane exhibits linearity over a wide concentration range 2.0x10-6–1.0x10-1M (0.12 – 5.8x103ppm with a slope of 29.6 mV/decade of activity while OMP based membrane showed linear potential response in the concentration range 1.0x10-5 –1.0x 10-1M (0.60 – 5.8x103ppm with a Nernstian slope of 29.0 mV/decade of activity. The electrode assembly works between pH 2.0 – 7.0, exhibits a fast response time of 10-15s and performed satisfactorily over a period of six months with good reproducibility. Excellent selectivity of the order of 10-3 over a number of cations and quantitative determination of Ni2+ in effluents discharged from electroplating industry demonstrates the utility of the proposed sensor. The electrode assembly was also used as an indicator electrode in the potentiometric titration of Ni2+ with EDTA.

  1. The development of PVC-laminated steel sheet by an electron beam curing method

    International Nuclear Information System (INIS)

    Masuhara, Ken-ichi; Koshiishi, Kenji; Tomosue, Takao; Mori, Koji; Honma, Nobuyuki

    1988-01-01

    Polyvinyl chloride (PVC) film-laminated steel sheets are used for household electric appliances and building materials. Those are produced usually by pressing a PVC film onto a steel sheet imediately after a themosetting adhesive has been applied to the sheet and curing. However, a major problem of this method is that the appearance of the PVC films such as gloss and embossment changes during pressing due to the heat that is required for causing bonding, therefore, the development of an adhesive which can be cured at lower temperature is necessary. Nisshin Steel Co., Ltd. has developed PVC film-laminated steel sheets for which electron beam (EB) curable adhesives are used to overcome this problem. The advantage of these adhesives is that they can be quickly cured at room temperature. The production procedure of PVC-laminated steel sheets by EB curing is outlined. But this method has encountered two problems: poor adhesion between substrates and adhesive due to the residual stress, and the deterioration of the PVC films due to EB irradiation. EB curable adhesives are mainly composed of acrylic ester oligomers and monomers, and thier adhesion was improved by organic pretreatment. On the other hand, EB-proof PVC films were developed. The general properties of PVC-laminated steel sheets produced by EB curing are reported. (K.I.)

  2. The Paradigms They Are a-Changin': past, present and future of PVC bacteria research.

    Science.gov (United States)

    Rivas-Marín, Elena; Devos, Damien P

    2018-06-01

    These are exciting times for PVC researchers! The PVC superphylum is composed of the bacterial phyla Planctomycetes, Verrucomicrobia, Chlamydiae (those three founders giving it its name), Lentisphaerae and Kirimatiellaeota as well as some uncultured candidate phyla, such as the Candidatus Omnitrophica (previously known as OP3). Despite early debates, most of the disagreements that surround this group of bacteria have been recently resolved. In this article, we review the history of the study of PVC bacteria, with a particular focus on the misinterpretations that emerged early in the field and their resolution. We begin with a historical perspective that describes the relevant facts of PVC research from the early times when they were not yet termed PVC. Those were controversial times and we refer to them as the "discovery age" of the field. We continue by describing new discoveries due to novel techniques and data that combined with the reinterpretations of old ones have contributed to solve most of the discordances and we refer to these times as the "illumination age" of PVC research. We follow by arguing that we are just entering the "golden age" of PVC research and that the future of this growing community is looking bright. We finish by suggesting a few of the directions that PVC researches might take in the future.

  3. Tumor cell invasion of collagen matrices requires coordinate lipid agonist-induced G-protein and membrane-type matrix metalloproteinase-1-dependent signaling

    Directory of Open Access Journals (Sweden)

    Anthis Nicholas J

    2006-12-01

    Full Text Available Abstract Background Lysophosphatidic acid (LPA and sphingosine 1-phosphate (S1P are bioactive lipid signaling molecules implicated in tumor dissemination. Membrane-type matrix metalloproteinase 1 (MT1-MMP is a membrane-tethered collagenase thought to be involved in tumor invasion via extracellular matrix degradation. In this study, we investigated the molecular requirements for LPA- and S1P-regulated tumor cell migration in two dimensions (2D and invasion of three-dimensional (3D collagen matrices and, in particular, evaluated the role of MT1-MMP in this process. Results LPA stimulated while S1P inhibited migration of most tumor lines in Boyden chamber assays. Conversely, HT1080 fibrosarcoma cells migrated in response to both lipids. HT1080 cells also markedly invaded 3D collagen matrices (~700 μm over 48 hours in response to either lipid. siRNA targeting of LPA1 and Rac1, or S1P1, Rac1, and Cdc42 specifically inhibited LPA- or S1P-induced HT1080 invasion, respectively. Analysis of LPA-induced HT1080 motility on 2D substrates vs. 3D matrices revealed that synthetic MMP inhibitors markedly reduced the distance (~125 μm vs. ~45 μm and velocity of invasion (~0.09 μm/min vs. ~0.03 μm/min only when cells navigated 3D matrices signifying a role for MMPs exclusively in invasion. Additionally, tissue inhibitors of metalloproteinases (TIMPs-2, -3, and -4, but not TIMP-1, blocked lipid agonist-induced invasion indicating a role for membrane-type (MT-MMPs. Furthermore, MT1-MMP expression in several tumor lines directly correlated with LPA-induced invasion. HEK293s, which neither express MT1-MMP nor invade in the presence of LPA, were transfected with MT1-MMP cDNA, and subsequently invaded in response to LPA. When HT1080 cells were seeded on top of or within collagen matrices, siRNA targeting of MT1-MMP, but not other MMPs, inhibited lipid agonist-induced invasion establishing a requisite role for MT1-MMP in this process. Conclusion LPA is a

  4. An Enhanced Soft Vibrotactile Actuator Based on ePVC Gel with Silicon Dioxide Nanoparticles.

    Science.gov (United States)

    Park, Won-Hyeong; Shin, Eun-Jae; Yun, Sungryul; Kim, Sang-Youn

    2018-01-01

    In this paper, we propose a soft vibrotactile actuator made by mixing silicon dioxide nanoparticles and plasticized PVC gel. The effect of the silicon dioxide nanoparticles in the plasticized PVC gel for the haptic performance is investigated in terms of electric, dielectric, and mechanical properties. Furthermore, eight soft vibrotactile actuators are prepared as a function of the content. Experiments are conducted to examine the haptic performance of the prepared eight soft vibrotactile actuators and to find the best weight ratio of the plasticized PVC gel to the nanoparticles. The experiments should show that the plasticized PVC gel with silicon dioxide nanoparticles improves the haptic performance of the plasticized PVC gel-based vibrotactile actuator, and the proposed vibrotactile actuator can create a variety of haptic sensations in a wide frequency range.

  5. Estudo de propriedades de PVC modificado com grupos alquila e benzila Study of the properties of PVC modified through substitution by alkyl and benzyl groups

    Directory of Open Access Journals (Sweden)

    G. M Vinhas

    2005-07-01

    Full Text Available O poli(cloreto de vinila (PVC é o segundo termoplástico mais consumido em todo o mundo, sendo considerado o mais versátil dentre os plásticos. A grande versatilidade do PVC deve-se a suas propriedades e também a sua adequação aos mais variados processos de transformação. Uma vez que a resina de PVC é atóxica e inerte, a escolha de aditivos com essas mesmas características, permite a fabricação de filmes para embalagens de alimentos e produtos médico-hospitalares. Entretanto, suas propriedades podem se alterar quando submetido a qualquer processo de esterilização, especialmente por radiação gama. Neste trabalho foi realizado um estudo sobre a flexibilidade e estabilidade frente à radiação gama do PVC modificado quimicamente. O PVC foi modificado pela substituição de átomos de cloro por grupos alquila e benzila através de reações com reagentes de Grignard. Amostras de PVC modificado foram caracterizadas por espectroscopia de ressonância magnética nuclear de hidrogênio (RMN ¹H, espectroscopia na região do infravermelho com transformada de Fourier e calorimetria diferencial exploratória. A degradação do PVC modificado, quando submetido à radiação gama, foi avaliada por seus parâmetros viscosimétricos. De uma forma geral, o PVC modificado apresentou maior estabilidade à radiação gama que o original. O polímero modificado por substituição do cloro por grupo que contém um anel aromático foi o que apresentou maior estabilidade, quando submetido à dose de esterilização de 25 kGy. O PVC modificado apresentou temperaturas de transição vítrea ligeiramente mais baixas que o PVC original, indicando uma tendência ao aumento de flexibilidade pela presença de grupos alquila e benzila na cadeia do polímero.Poly(vinyl chloride (PVC ranks second among the most consumed thermoplastics in the world, and is considered the most versatile plastic. This versatility arises from its properties and suitability to a

  6. Polymer membrane electrodes for sensitive potentiometric determination of beta-blockers.

    Science.gov (United States)

    Wassil, Anwar A; Farag, Abd El-Ftaah Bastawy; Moukdad, Fatma A

    2007-01-01

    The construction of PVC matrix-type beta-blockers (sotalol, carvedilol, and betaxolol) ion selective electrodes and their use for direct potentiometry of their respective species are described. The proposed sensors are based on the complex ion associates of beta-blockers with tungstophosphate (TP) and Ammonium Reineckate (Rein) ionophoris in poly vinyl chloride membrane (PVC) with Dioctylphthalate (DOP) plasticizer. The four electrodes (Beta-TP), (Sota-TP), (Carve-TP), and (Cave-Rein) show stable potential response with near Nernstian slope of 50.8, 33.7, 32.35, and 33 mv per decade, range of concentration 10-2-10-7 M beta-blockers. Selectivity coefficients data obtained for 11 different organic and inorganic ions are presented. The electrodes have fast response time (30 and 40 s) and were used over wide range of pH 4.5-8.5. Validation of the method according to the quality assurance standers shows suitability of proposed sensors for use in the quality control assessment of these drugs. The results obtained for the determination of beta-blockers with the proposed electrodes show average recoveries of 100.78% and a mean standard deviation of +/-1.2. The nominal are obtained. The data agree well with those obtained by standard methods.

  7. A Solid Binding Matrix/Mimic Receptor-Based Sensor System for Trace Level Determination of Iron Using Potential Measurements

    Directory of Open Access Journals (Sweden)

    Ayman H. Kamel

    2011-01-01

    Full Text Available Iron(II-(1,10-phenanthroline complex imprinted membrane was prepared by ionic imprinting technology. In the first step, Fe(II established a coordination linkage with 1,10-phenanthroline and functional monomer 2-vinylpyridine (2-VP. Next, the complex was copolymerized with ethylene glycol dimethacrylate (EGDMA as a crosslinker in the presence of benzoyl peroxide (BPO as an initiator. Potentiometric chemical sensors were designed by dispersing the iron(II-imprinted polymer particles in 2-nitrophenyloctyl ether (o-NPOE plasticizer and then embedded in poly vinyl chloride (PVC matrix. The sensors showed a Nernstian response for [Fe(phen3]2+ with limit of detection 3.15 ng mL−1 and a Nernstian slope of 35.7 mV per decade.

  8. Migration of plasticisers from PVC and other polymers

    DEFF Research Database (Denmark)

    Lundsgaard, Rasmus

    ). In this work it is shown how diffusion coefficients can be obtained by regression of experimental migration data plotted as the square root of time. This was done from plasticiser migration data of GRINDSTEDr SOFT-N-SAFE, GRINDSTEDr ACETEM 95 CO (Acetem) and Epoxidised Soybean Oil (ESBO) migrating from......The main purpose of this thesis is to investigate, from a modeling point of view, the migration of GRINDSTEDr SOFT-N-SAFE (SNS) and other plasticisers from polyvinyl chloride (PVC) and polyolefin food package materials and into foodstuff (specifically the four food simulants set by EU legislation...... coefficients at 20◦C, except at higher temperatures. Using the finite element mesh method in Matlab and COMSOL environments the migration was modeled with a diffusion coefficient able to change with local plasticiser concentration. Three different models for this plasticiser concentration dependence...

  9. Print Quality of Ink Jet Printed PVC Foils

    Directory of Open Access Journals (Sweden)

    Nemanja Kašiković

    2015-09-01

    Full Text Available Digital printing technique is used for a wide variety of substrates, one of which are PVC foils. Samples used in this research were printed by digital ink jet printing technique using Mimaki JV22 printing machine and J-Eco Subly Nano inks. As printing substrates, two different types of materials were used (ORACAL 640 - Print Vinyl and LG Hausys LP2712. A test card consisting of fields of CMYK colours was created and printed, varying the number of ink layers applied. Samples were exposed to light after the printing process. Spectrophotometric measurements were conducted before and after the light treatment. Based on spectrophotometricaly obtained data, colour differences ΔE2000 were calculated. Results showed that increasing number of layers, as well as the right choice of substrates, can improve the behaviour of printed product during exploitation.

  10. Model decontamination of PVC flooring specimens by wet method

    International Nuclear Information System (INIS)

    Severa, J.; Knajfl, J.; Bar, J.

    1981-01-01

    PVC flooring samples of 29 mm in diameter were used in experiments. The samples were degreased. Tested were the dependence of the degree of contamination on the duration of contact with the contaminant and the efficacy of decontamination by wiping with tampons and immersing in solutions. A mixture of fission products of 80 kBq/ml in specific activity was used for contamination. Higher decontamination efficacy was achieved by immersing the samples in decontamination solutions. Water was found to be the least efficacious medium; a high degree was only attained in the case when decontamination was effected within 1 minute after contamination. The highest decontamination values were achieved using solutions containing a chelating agent and a surfactant. The most efficacious solutions contained 0.5% of citric acid and 0.5% of detergents which are very potent at a concentration as low as 2 g/l. (J.P.)

  11. Matrix metalloproteinase-2 and its correlation with basal membrane components laminin-5 and collagen type IV in paediatric burn patients measured with Surface Plasmon Resonance Imaging (SPRI) biosensors.

    Science.gov (United States)

    Weremijewicz, Artur; Matuszczak, Ewa; Sankiewicz, Anna; Tylicka, Marzena; Komarowska, Marta; Tokarzewicz, Anna; Debek, Wojciech; Gorodkiewicz, Ewa; Hermanowicz, Adam

    2018-01-30

    The purpose of this study was the determination of matrix metalloproteinase-2 and its correlation with basal membrane components laminin-5 and collagen type IV in the blood plasma of burn patients measured with Surface Plasmon Resonance Imaging (SPRI) biosensors. 31 children scalded by hot water who were managed at the Department of Paediatric Surgery between 2014-2015, after primarily presenting with burns in 4-20% TBSA were included into the study (age 9 months up to 14 years, mean age 2,5+1 years). There were 10 girls and 21 boys. Venous blood samples were drawn 2-6h, and 12-16h after the thermal injury, and on the subsequent days 3, 5 and 7. The matrix metalloproteinase-2, collagen type IV and laminin-5 concentrations were assessed using Surface Plasmon Resonance Imaging by the investigators blinded to the other data. The MMP-2, laminin-5 and collagen type IV concentrations in the blood plasma of patients with burns, were highest 12-16h after thermal injury, the difference was statistically significant. The MMP-2, laminin-5 and collagen type IV concentrations measured 3 days, 5 days and 7 days after the thermal injury, slowly decreased over time, and on the 7th day reached the normal range, when compared with the concentration measured in controls. Current work is the first follow-up study regarding MMP-2 in burns. MMP-2, laminin-5 and collagen type IV levels were elevated early after burn injury in the plasma of studied patients, and were highest 12-16h after the injury. MMP-2, laminin-5 and collagen type IV levels were not proportional to the severity of the burn. We believe in the possibility that the gradual decrease of MMP-2, collagen type IV and laminin-5 concentrations could be connected with the process of healing, but to prove it, more investigation is needed in this area. The SPR imaging biosensor is a good diagnostic tool for determination of MMP-2, laminin-5 and collagen type IV in blood plasma of patients with burns. Copyright © 2017 Elsevier Ltd

  12. Reduction of facial wrinkles by hydrolyzed water-soluble egg membrane associated with reduction of free radical stress and support of matrix production by dermal fibroblasts

    Directory of Open Access Journals (Sweden)

    Jensen GS

    2016-10-01

    Full Text Available Gitte S Jensen,1 Bijal Shah,2 Robert Holtz,3 Ashok Patel,4 Donald C Lo2 1NIS Labs, Klamath Falls, OR, 2Department of Neurobiology, Center for Drug Discovery, Duke University Medical Center, Durham, NC, 3BioInnovation Laboratories, Inc., Lakewood, CO, 4Centre Manufacturing LLC, Eden Prairie, MN, USA Objective: The aim of this study was to evaluate the effects of water-soluble egg membrane (WSEM on wrinkle reduction in a clinical pilot study and to elucidate specific mechanisms of action using primary human immune and dermal cell-based bioassays.Methods: To evaluate the effects of topical application of WSEM (8% on human skin, an open-label 8-week study was performed involving 20 healthy females between the age of 45 years and 65 years. High-resolution photography and digital analysis were used to evaluate the wrinkle depth in the facial skin areas beside the eye (crow’s feet. WSEM was tested for total antioxidant capacity and effects on the formation of reactive oxygen species by human polymorphonuclear cells. Human keratinocytes (HaCaT cells were used for quantitative polymerase chain reaction analysis of the antioxidant response element genes Nqo1, Gclm, Gclc, and Hmox1. Evaluation of effects on human primary dermal fibroblasts in vitro included cellular viability and production of the matrix components collagen and elastin.Results: Topical use of a WSEM-containing facial cream for 8 weeks resulted in a significant reduction of wrinkle depth (P<0.05. WSEM contained antioxidants and reduced the formation of reactive oxygen species by inflammatory cells in vitro. Despite lack of a quantifiable effect on Nrf2, WSEM induced the gene expression of downstream Nqo1, Gclm, Gclc, and Hmox1 in human keratinocytes. Human dermal fibroblasts treated with WSEM produced more collagen and elastin than untreated cells or cells treated with dbcAMP control. The increase in collagen production was statistically significant (P<0.05.Conclusion: The topical use

  13. Poliomyelitis in MuLV-infected ICR-SCID mice after injection of basement membrane matrix contaminated with lactate dehydrogenase-elevating virus.

    Science.gov (United States)

    Carlson Scholz, Jodi A; Garg, Rohit; Compton, Susan R; Allore, Heather G; Zeiss, Caroline J; Uchio, Edward M

    2011-10-01

    The arterivirus lactate dehydrogenase-elevating virus (LDV) causes life-long viremia in mice. Although LDV infection generally does not cause disease, infected mice that are homozygous for the Fv1(n) allele are prone to develop poliomyelitis when immunosuppressed, a condition known as age-dependent poliomyelitis. The development of age-dependent poliomyelitis requires coinfection with endogenous murine leukemia virus. Even though LDV is a common contaminant of transplantable tumors, clinical signs of poliomyelitis after inadvertent exposure to LDV have not been described in recent literature. In addition, LDV-induced poliomyelitis has not been reported in SCID or ICR mice. Here we describe the occurrence of poliomyelitis in ICR-SCID mice resulting from injection of LDV-contaminated basement membrane matrix. After exposure to LDV, a subset of mice presented with clinical signs including paresis, which was associated with atrophy of the hindlimb musculature, and tachypnea; in addition, some mice died suddenly with or without premonitory signs. Mice presenting within the first 6 mo after infection had regions of spongiosis, neuronal necrosis and astrocytosis of the ventral spinal cord, and less commonly, brainstem. Axonal degeneration of ventral roots prevailed in more chronically infected mice. LDV was identified by RT-PCR in 12 of 15 mice with typical neuropathology; positive antiLDV immunolabeling was identified in all PCR-positive animals (n = 7) tested. Three of 8 mice with neuropathology but no clinical signs were LDV negative by RT-PCR. RT-PCR yielded murine leukemia virus in spinal cords of all mice tested, regardless of clinical presentation or neuropathology.

  14. Retroviral gene transfer of an antisense construct against membrane type 1 matrix metalloproteinase reduces the invasiveness of rheumatoid arthritis synovial fibroblasts.

    Science.gov (United States)

    Rutkauskaite, Edita; Volkmer, Dagmar; Shigeyama, Yukio; Schedel, Jörg; Pap, Geza; Müller-Ladner, Ulf; Meinecke, Ingmar; Alexander, Dorothea; Gay, Renate E; Drynda, Susanne; Neumann, Wolfram; Michel, Beat A; Aicher, Wilhelm K; Gay, Steffen; Pap, Thomas

    2005-07-01

    Membrane type 1 matrix metalloproteinase (MT1-MMP) is expressed prominently in rheumatoid arthritis synovial fibroblasts (RASFs), but the specific contribution of MT1-MMP to fibroblast-mediated destruction of articular cartilage is incompletely understood. This study used gene transfer of an antisense expression construct to assess the effects of MT1-MMP inhibition on the invasiveness of RASFs. Retroviral gene transfer of a pLXIN vector-based antisense RNA expression construct (MT1-MMPalphaS) to MT1-MMP was used to stably transduce RASFs. Levels of MT1-MMP RNA and protein were determined by quantitative polymerase chain reaction, Western blotting, and immunocytochemistry in MT1-MMPalphaS-transduced RASFs as well as in control cells, with monitoring for 60 days. The effects of MT1-MMPalphaS on the invasiveness of RASFs were analyzed in the SCID mouse co-implantation model of RA. MT1-MMPalphaS-transduced RASFs produced high levels of antisense RNA that exceeded endogenous levels of MT1-MMP messenger RNA by 15-fold and resulted in a down-regulation of MT1-MMP at the protein level. Inhibition of MT1-MMP production was maintained for 60 days and significantly reduced the invasiveness of RASFs in the SCID mouse model. Whereas prominent invasion into cartilage by non-transduced and mock-transduced RASFs was observed (mean invasion scores 3.0 and 3.1, respectively), MT1-MMPalphaS-transduced cells showed only moderate invasiveness (mean invasion score 1.8; P < 0.05). The data demonstrate that an antisense RNA expression construct against MT1-MMP can be generated and expressed in RASFs for at least 60 days. Inhibition of MT1-MMP significantly reduces the cartilage degradation by RASFs.

  15. Membrane Type 1–Matrix Metalloproteinase/Akt Signaling Axis Modulates TNF-α-Induced Procoagulant Activity and Apoptosis in Endothelial Cells

    Science.gov (United States)

    Ohkawara, Hiroshi; Ishibashi, Toshiyuki; Sugimoto, Koichi; Ikeda, Kazuhiko; Ogawa, Kazuei; Takeishi, Yasuchika

    2014-01-01

    Membrane type 1–matrix metalloproteinase (MT1-MMP) functions as a signaling molecule in addition to a proteolytic enzyme. Our hypothesis was that MT1-MMP cooperates with protein kinase B (Akt) in tumor necrosis factor (TNF)-α-induced signaling pathways of vascular responses, including tissue factor (TF) procoagulant activity and endothelial apoptosis, in cultured human aortic endothelial cells (ECs). TNF-α (10 ng/mL) induced a decrease in Akt phosphorylation within 60 minutes in ECs. A chemical inhibitor of MMP, TIMP-2 and selective small interfering RNA (siRNA)-mediated suppression of MT1-MMP reversed TNF-α-triggered transient decrease of Akt phosphorylation within 60 minutes, suggesting that MT1-MMP may be a key regulator of Akt phosphorylation in TNF-α-stimulated ECs. In the downstream events, TNF-α increased TF antigen and activity, and suppressed the expression of thrombomodulin (TM) antigen. Inhibition of Akt markedly enhanced TNF-α-induced expression of TF antigen and activity, and further reduced the expression of TM antigen. Silencing of MT1-MMP by siRNA also reversed the changed expression of TF and TM induced by TNF-α. Moreover, TNF-α induced apoptosis of ECs through Akt- and forkhead box protein O1 (FoxO1)-dependent signaling pathway and nuclear factor-kB (NF-kB) activation. Knockdown of MT1-MMP by siRNA reversed apoptosis of ECs by inhibiting TNF-α-induced Akt-dependent regulation of FoxO1 in TNF-α-stimulated ECs. Immunoprecipitation demonstrated that TNF-α induced the changes in the associations between the cytoplasmic fraction of MT1-MMP and Akt in ECs. In conclusion, we show new evidence that MT1-MMP/Akt signaling axis is a key modifier for TNF-α-induced signaling pathways for modulation of procoagulant activity and apoptosis of ECs. PMID:25162582

  16. Conversion of Stationary to Invasive Tumor Initiating Cells (TICs): Role of Hypoxia in Membrane Type 1-Matrix Metalloproteinase (MT1-MMP) Trafficking

    Science.gov (United States)

    Li, Jian; Zucker, Stanley; Pulkoski-Gross, Ashleigh; Kuscu, Cem; Karaayvaz, Mihriban; Ju, Jingfang; Yao, Herui; Song, Erwei; Cao, Jian

    2012-01-01

    Emerging evidence has implicated the role of tumor initiating cells (TICs) in the process of cancer metastasis. The mechanism underlying the conversion of TICs from stationary to invasive remains to be characterized. In this report, we employed less invasive breast cancer TICs, SK-3rd, that displays CD44high/CD24low with high mammosphere-forming and tumorigenic capacities, to investigate the mechanism by which stationary TICs are converted to invasive TICs. Invasive ability of SK-3rd TICs was markedly enhanced when the cells were cultured under hypoxic conditions. Given the role of membrane type 1-matrix metalloproteinase (MT1-MMP) in cancer invasion/metastasis, we explored a possible involvement of MT1-MMP in hypoxia-induced TIC invasion. Silencing of MT1-MMP by a shRNA approach resulted in diminution of hypoxia-induced cell invasion in vitro and metastasis in vivo. Under hypoxic conditions, MT1-MMP redistributed from cytoplasmic storage pools to the cell surface of TICs, which coincides with the increased cell invasion. In addition, CD44, a cancer stem-like cell marker, inversely correlated with increased cell surface MT1-MMP. Interestingly, cell surface MT1-MMP gradually disappeared when the hypoxia-treated cells were switched to normoxia, suggesting the plasticity of TICs in response to oxygen content. Furthermore, we dissected the pathways leading to upregulated MT1-MMP in cytoplasmic storage pools under normoxic conditions, by demonstrating a cascade involving Twist1-miR10b-HoxD10 leading to enhanced MT1-MMP expression in SK-3rd TICs. These observations suggest that MT1-MMP is a key molecule capable of executing conversion of stationary TICs to invasive TICs under hypoxic conditions and thereby controlling metastasis. PMID:22679501

  17. Membrane type 1-matrix metalloproteinase/Akt signaling axis modulates TNF-α-induced procoagulant activity and apoptosis in endothelial cells.

    Directory of Open Access Journals (Sweden)

    Hiroshi Ohkawara

    Full Text Available Membrane type 1-matrix metalloproteinase (MT1-MMP functions as a signaling molecule in addition to a proteolytic enzyme. Our hypothesis was that MT1-MMP cooperates with protein kinase B (Akt in tumor necrosis factor (TNF-α-induced signaling pathways of vascular responses, including tissue factor (TF procoagulant activity and endothelial apoptosis, in cultured human aortic endothelial cells (ECs. TNF-α (10 ng/mL induced a decrease in Akt phosphorylation within 60 minutes in ECs. A chemical inhibitor of MMP, TIMP-2 and selective small interfering RNA (siRNA-mediated suppression of MT1-MMP reversed TNF-α-triggered transient decrease of Akt phosphorylation within 60 minutes, suggesting that MT1-MMP may be a key regulator of Akt phosphorylation in TNF-α-stimulated ECs. In the downstream events, TNF-α increased TF antigen and activity, and suppressed the expression of thrombomodulin (TM antigen. Inhibition of Akt markedly enhanced TNF-α-induced expression of TF antigen and activity, and further reduced the expression of TM antigen. Silencing of MT1-MMP by siRNA also reversed the changed expression of TF and TM induced by TNF-α. Moreover, TNF-α induced apoptosis of ECs through Akt- and forkhead box protein O1 (FoxO1-dependent signaling pathway and nuclear factor-kB (NF-kB activation. Knockdown of MT1-MMP by siRNA reversed apoptosis of ECs by inhibiting TNF-α-induced Akt-dependent regulation of FoxO1 in TNF-α-stimulated ECs. Immunoprecipitation demonstrated that TNF-α induced the changes in the associations between the cytoplasmic fraction of MT1-MMP and Akt in ECs. In conclusion, we show new evidence that MT1-MMP/Akt signaling axis is a key modifier for TNF-α-induced signaling pathways for modulation of procoagulant activity and apoptosis of ECs.

  18. Protein valves prepared by click reaction grafting of poly(N-isopropylacrylamide) to electrospun poly(vinyl chloride) fibrous membranes

    Science.gov (United States)

    Guo, Jian-Wei; Lin, Zhen-Yu; Chang, Chi-Jung; Lu, Chien-Hsing; Chen, Jem-Kun

    2018-05-01

    In this study, poly(vinyl chloride) (PVC) was electrospun into fibrous membranes and then reacted with NaN3 to generate azido-terminated PVC fibrous membranes. A propargyl-terminated poly(N-isopropylacrylamide) (PNIPAAm) was also synthesized and then grafted, through click reactions, onto the azido-terminated PVC fiber surface. Protrusion-, scale-, and joint-like structures of the PNIPAAm grafts on the PVC fibers were formed upon increasing the molecular weight of the PNIPAAm grafts. The PNIPAAm-grafted PVC fibrous mats exhibited completely wetted surfaces at 25 °C because of their high roughness. The static water contact angle of the PNIPAAm-grafted PVC fibrous mats reached 140° when the temperature was increased to 45 °C. This thermoresponsive behavior was significantly greater than that of the PNIPAAm grafted on a flat surface. Temperature-responsive membranes were constructed having a pore size of 1.38 μm and applied as protein valves to block and release an antibody (fluorescein-conjugated AffiniPure goat anti-rabbit IgG). At 25 °C, the collection efficiency remained at 94% for antibody concentrations up to 60 ng/L. As the temperature increased to 45 °C, the collection efficiency decreased abruptly, to 4%, when the antibody concentration was greater than 20 ng/L. Accordingly, this system of PNIPAAm-grafted PVC fibers functioned as a protein valve allowing the capture and concentration of proteins.

  19. Preparation of modified clay with benzethonium or cetylpyridinium chloride and evaluation of their interactions with PVC

    International Nuclear Information System (INIS)

    Resende, Daniel K.; Dornelas, Camila B.; Moreira, Leonardo A.; Gomes, Ailton S.; Tavares, Maria I.B.; Cabral, Lucio M.; Simeoni, Luiz A.

    2009-01-01

    The objective of this work was the preparation of modified clays with benzethonium or cetylpyridinium to obtain organophilic silicates with good stability and evaluate the possible use of them for the preparation of nanocomposites of poly(vinyl chloride) (PVC). The reactions of modification of clays and the PVC were prepared by solution intercalation. The new clays were evaluated by X-ray diffraction (XRD) and Low field nuclear magnetic resonance (NMR). The reactions of clays with PVC were assessed by Low-field NMR, through the determination of proton spin lattice relaxation time. The stability of new organophilic clays and their reactions with PVC were evaluated by thermogravimetric analysis (TGA). High stability was observed for organophilic clays prepared. The degradation of PVC materials obtained with the organophilic clay began at temperatures above 200 deg C. If it is considered that the temperatures normally used in the processing of PVC are between 140 deg C to 180 deg C, the observed results may indicate the possibility of the use of clays for preparation of nanomaterials with PVC. (author)

  20. PVC mixtures’ mechanical properties with the addition of modified calcite as filler

    Directory of Open Access Journals (Sweden)

    Vučinić Dušica R.

    2012-01-01

    Full Text Available In this study mechanical properties of PVC mixtures (PVC, stabilizer, lubricant, filler such as tensile strength, tensile elongation, breaking strength, and breaking elongation were investigated. Unmodified calcite, as well as calcite modified by stearic acid, were used as fillers in wet and dry processes. The PVC mixtures containing the calcite modified by wet procedure have better mechanical properties compared to those with the calcite modified by the dry process. Tensile and breaking strength of the PVC mixture containing the calcite modified with 1.5% stearic acid using wet process, are higher for 2.8% and 5.2%, respectively, compared to the PVC mixture containing the calcite modified with the same amount of acid used in the dry process. The tensile strength difference between the mixtures increases with the increase of the concentration of used stearic acid up to 3%. The strength of PVC mixture with the calcite modified by wet process is 3.1% higher compared to the mixture containing calcite modified by dry process. The results showed that the bonding strength between calcite and the adsorbed organic component affected tensile strength, tensile elongation and breaking strength of the PVC mixtures. The best filler was obtained by wet modification using 1.5% stearic acid solution that provided the formation of a stearate monolayer chemisorbed on calcite. The PVC mixtures containing the calcite modified by wet process using 1.5% stearic acid solution exhibited the best mechanical properties. This calcite was completely hydrophobic with dominant chemically adsorbed surfactant, which means that stearate chemisorbed on calcite provided stronger interaction in the calcite-stearic acid-PVC system.

  1. A.C. impedance, XRD, DSC, SEM and charge/discharge studies on Al2O3, TiO2, SiO2 dispersoid LiPF6/PVC/PVdF-co-HFP composite polymer electrolytes by phase inversion

    Science.gov (United States)

    Vickraman, P.; Gopukumar, S.

    2017-07-01

    The PVC/PVdF-co-HFP composite polymer electrolyte membranes (CPEMs) by varying blend ratios 1:1, 1:2, and 2:1 with fixed content of Al2O3, TiO2 and SiO2 having soaked in 0.5 M LiPF6 in EC/DEC (1:1) v/v) have been prepared by phase inversion. CPEMs of higher ionic conductivity (not dependent on electrolyte uptake as observed in our study) ASA4 (3.61×10-4 Scm-1), TSA3 (1.53×10-4 Scm-1), and SSA3 (4.81×10-4 Scm-1) have been only chosen for XRD, DSC, SEM and electrochemical studies. In XRD, crystalline peaks (phases) of PVdF have been noted with/without change in intensity as well as FWHM which correspond to type of filler interaction with host matrix. In DSC, it is observed that shifts in baseline, melting endotherms, and area under the endotherms indicating the thermal hist ory of PVC (Tg = 82 ° C) and melting of VdF crystallites varied with nature of the filler dispersoid. In SEM, the coagulated fibrils of the polymer coiled with the sponge like structure has been mapped. The charge/discharge studies are carried out on these CPEMs at C/10 rate in the voltage range 2.8 V - 4.2 V, and it is noted that the TSA3 showed better cycling performance with good capacity retention i.e., 50 cycles with 66% capacity retention than ASA4 of 28 cycles with 65% and SSA3 of 5 cycles with 56%. In the present study Coulombic efficiency is concerned only for first cycle and it is noted that the TSA3 showed 71% than 66% and 62% respectively for SSA3 and ASA4.

  2. Dose Rate Effect on Grafting by Gamma Radiation of DMAEMA onto Flexible PVC

    International Nuclear Information System (INIS)

    Panzarini, L.C.G.A.; Araujo, F.D.C.; Martinello, V.C.; Somesari, E.; Manzoli, J.E.; Silveira, C.; Paes, H.A.; Moura, E.

    2009-01-01

    Intravenous tubing, blood bags and catheters stays in contact with blood and body fluids. They are normally made by flexible PVC. The contact of PVC with this fluid is not possible for long periods and there is the necessity of addition of non-thrombogenic substances into blood. This work shows the radiation grafting process to produce copolymer PVC-g-DMAEMA, a new material that allows a future grafting of Heparin on it, and will have the perspective of avoiding undesirable substances additions to blood or body fluid contact. In this preliminary work, only radiation dose rate effect on grafting was studied

  3. Penelitian pengaruh asam sulfat terhadap sifat fisika kekerasan atasan sepatu kerja PVC

    Directory of Open Access Journals (Sweden)

    Kusumo Retno Winahyu

    1996-12-01

    Full Text Available The Research of hardness aspect of PVC boot upper treated by sulfuric acid to detect influence of sulfuric acid to hardness upper on PVC boot upper. The method of the research has been done by immersing samples in sulfuric acid solution 30 % (v/v for 24 hours. After immersing samples examined connected with hardness physical property. The result of the research shown that hardness physical property become decreasing until 16,08 % has error standard 5,48. It is still agree with SNI 12 – 1848-1990. Sepatu bot dari PVC.

  4. Sonochemical synthesis of stibnite nanoparticles and their use as radiolytic stabilizer in polynomial chloride matrix

    International Nuclear Information System (INIS)

    Albuquerque, Marilia Cordeiro C. de; Lima, Thaysa Araujo de; Aquino, Katia Aparecida da Silva; Araujo, Elmo S.

    2011-01-01

    Stibnite (Sb 2 S 3 ) was synthesized by sonochemical method. Amorphous powder of Sb 2 S 3 was obtained and exhibit nanospheres structure with an average size in the range of 300-500 nm. Commercial Polyvinyl Chloride (PVC) containing Sb 2 S 3 nanoparticles (PVC/Sb) at concentrations of 0.10; 0.30 and 0.50 wt% were investigated. The samples were irradiated with gamma radiation ( 60 Co) at room temperature and air atmosphere. The viscosity-average molar mass (M v ) was measured for PVC systems without nanoparticles and with nanoparticles. Decreases in molar mass observed when the systems were gamma irradiated reflect the random scission effects that take place in the main chain. Degradation index (DI) value was also obtained by viscosity analysis. DI results showed that the addition of Sb 2 S 3 nanoparticles at 0.3 wt% into PVC matrix irradiated at dose of 25 kGy decreased the number of main chain scissions and was calculated a protection index of 66,5% in PVC matrix. Results about the free radical scavenger action of the Sb 2 S 3 were obtained by use of 2,2-diphenyl-1-(2,4,6-trinitrophenyl)-hydrazyl radical (DPPH) and are discussed in this study. Changes in the infrared spectra of PVC systems indicated that polymer molecules interact with Sb 2 S 3 nanoparticles. (author)

  5. Evaluation of the influence of water and oil derivatives absorption on PVC pipes

    International Nuclear Information System (INIS)

    Carpio, D.C.F. del; D'Almeida, J.R.M.

    2010-01-01

    PVC is the only polymer of large consume that is not totally obtained from petroleum, since it contains 57% of chlorine. As chlorine containing materials are resistant to bacteria rich environments, such as buried pipes, PVC is being used for fluid transportation, principally water, but it can also be considered as an alternative material for the transportation of other fluids. This work analyzes the aging behavior of PVC exposed to water, ethanol and diesel oil, using TGA, DSC, FT-IR and DR-X techniques. The results showed that the chemical structure of PVC is not affected by exposure to water and ethanol. For these fluids a dipolar interaction could be occurring, increasing at the beginning of the absorption process, the polymer thermal stability. The diesel oil caused plasticization, with reduction of the Tg since the beginning of the aging process. (author)

  6. Photostabilizing Efficiency of PVC in the Presence of Schiff Bases as Photostabilizers

    Directory of Open Access Journals (Sweden)

    Emad Yousif

    2015-11-01

    Full Text Available The photostabilization of polyvinyl chloride (PVC films by Schiff bases was investigated. Polyvinyl chloride films containing 0.5 wt % Schiff bases were produced using the same casting method as that used for additive-free PVC films from tetrahydrofuran (THF solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also monitored using THF as a solvent. The quantum yield of chain scission (Φcs for the studied complexes in PVC was estimated to range between 4.72 and 8.99 × 10−8. According to the experimental results, several mechanisms were suggested, depending on the structure of the additive. Ultra violet (UV absorption, peroxide decomposition and radical scavenging were suggested as the photostabilizing mechanisms.

  7. Investigation of Ice-PVC separation under Flexural Loading using FEM Analysis

    Directory of Open Access Journals (Sweden)

    H Xue

    2016-08-01

    Full Text Available This paper presents the FEM technique applied in the study of ice separation over a polyvinyl chloride (PVC surface. A two layer model of ice and PVC is analysed theoretically using Euler-Bernoulli beam theory and the rule of mixtures. The physical samples are prepared by freezing ice over the PVC surfaces. The samples are tested experimentally in a four-point loading setup. The experimental results contain strain data gathered through a data acquisition system using the LabView software. The data is collected at the rate of 1 kHz per load step. A model is also coded in MATLAB® and simulated using the finite element method (FEM in ANSYS® Multiphysics. The FEM model of the ice and PVC sample is built using solid elements. The mesh is tested for sensitively. A good agreement is found between the theoretical, experimental and numerical simulation results.

  8. D-FNN Based Modeling and BP Neural Network Decoupling Control of PVC Stripping Process

    Directory of Open Access Journals (Sweden)

    Shu-zhi Gao

    2014-01-01

    Full Text Available PVC stripping process is a kind of complicated industrial process with characteristics of highly nonlinear and time varying. Aiming at the problem of establishing the accurate mathematics model due to the multivariable coupling and big time delay, the dynamic fuzzy neural network (D-FNN is adopted to establish the PVC stripping process model based on the actual process operation datum. Then, the PVC stripping process is decoupled by the distributed neural network decoupling module to obtain two single-input-single-output (SISO subsystems (slurry flow to top tower temperature and steam flow to bottom tower temperature. Finally, the PID controller based on BP neural networks is used to control the decoupled PVC stripper system. Simulation results show the effectiveness of the proposed integrated intelligent control method.

  9. Analysis of Phthalate Ester Content in PVC Plastics by means of FT-Raman Spectroscopy

    DEFF Research Database (Denmark)

    Nørbygaard, Thomas; Berg, Rolf W.

    2004-01-01

    Polyvinyl chloride, PVC or [CH2-CHCl]n , is a common polymer used extensively for a wide range of industrial and household products. To achieve the proper material characteristics (e.g. softness, ductility), plasticizers such as phthalates are usually added to the otherwise hard and brittle PVC......, medical devices and toys may harm the e.g. reproductive organs of exposed infants. PVC is readily distinguished from other common polymers (e.g. polyethylene, polypropylene, polystyrene) by the use of Raman spectroscopy. By far the most commonly used phthalate plasticizer in PVC is di(2-ethylhexyl......-phenyl group, and as the relative intensities of the six bands vary only slightly from one phthalate ester to the next one we have obtained an identifiable, characteristic fingerprint of the phthalate ester group as a whole. By use of the set of six bands, which are common to all the measured Raman spectra, we...

  10. ELECTROCHEMICAL OXIDATION OF ETHANOL USING Ni-Co-PVC COMPOSITE ELECTRODE

    Directory of Open Access Journals (Sweden)

    Riyanto Riyanto

    2011-07-01

    Full Text Available The morphological characteristics and electrochemical behavior of nickel metal foil (Ni, nickel-polyvinyl chloride (Ni-PVC and nickel-cobalt-polyvinyl chloride (Ni-Co-PVC electrodes in alkaline solution has been investigated. The morphological characteristics of the electrode surface were studied using SEM and EDS, while the electrochemical behavior of the electrodes was studied using cyclic voltammetry (CV. It was found that composite electrodes (Ni-PVC and Ni-Co-PVC have a porous, irregular and rough surface. In situ studies using electrochemical technique using those three electrodes exhibited electrochemical activity for redox system, as well as selectivity in the electrooxidation of ethanol to acetic acid. The studies also found that an electrokinetics and electrocatalytic activity behaviors of the electrodes prepared were Ni metal foil

  11. Development of a passive sampler based on a polymer inclusion membrane for total ammonia monitoring in freshwaters.

    Science.gov (United States)

    Almeida, M Inês G S; Silva, Adélia M L; Coleman, Rhys A; Pettigrove, Vincent J; Cattrall, Robert W; Kolev, Spas D

    2016-05-01

    A passive sampler for determining the time-weighted average total ammonia (i.e. molecular ammonia and the ammonium cation) concentration (C TWA) in freshwaters, which incorporated a polymer inclusion membrane (PIM) as a semi-permeable barrier separating the aqueous source solution from the receiving solution (i.e. 0.8 mol L(-1) HCl), was developed for the first time. The PIM was composed of dinonylnaphthalene sulfonic acid (DNNS) as a carrier, poly (vinyl chloride) (PVC) as a base polymer and 1-tetradecanol as a modifier. Its optimal composition was found to be 35 wt% commercial DNNS, 55 wt% PVC and 10 wt% 1-tetradecanol. The effect of environmental variables such as the water matrix, pH and temperature were also studied using synthetic freshwaters. The passive sampler was calibrated under laboratory conditions using synthetic freshwaters and exhibited a linear response within the concentration range 0.59-2.8 mg L(-1) NH4(+) (0.46-2.1 mg N L(-1)) at 20 °C. The performance of the sampler was further investigated under field conditions over 7 days. A strong correlation between spot sampling and passive sampling was achieved, thus providing a proof-of-concept for the passive sampler for reliably measuring the C(TWA) of total ammonia in freshwaters, which can be used as an indicator in tracking sources of faecal contamination in stormwater drains.

  12. Bedside identification of patients at risk for PVC-induced cardiomyopathy: Is ECG useful?

    Science.gov (United States)

    Garster, Noelle C; Henrikson, Charles A

    2017-07-01

    Premature ventricular complexes (PVCs) are an underrecognized cause of cardiomyopathy. Standard 12-lead electrocardiogram (ECG) has potential to direct attention toward at-risk patients. We performed a single-center, retrospective chart review of 1,240 patients who completed ECG and Holter monitoring at Oregon Health and Science University Hospital between January 1, 2011 and December 31, 2013 to investigate the relationship of PVC frequency on ECG with burden on Holter. Primary outcome measures included PVC quantity on ECG, mean PVC quantity on Holter, and percentage of total beats on Holter recorded as PVCs. High PVC burden was defined as ≥10% of total beats. Weighted mean percentages of total beats on Holter monitor recorded as PVCs were calculated for 0, 1, 2, and ≥3 PVCs on ECG and found to be 1.4% (n = 1,128), 3.5% (n = 32), 4.3% (n = 25), and 16.6% (n = 55), respectively, which represent statistically significant differences (P ECG for ≥10% PVC Holter burden was 58%. Negative predictive value for 0 PVCs on ECG was 98%. The sensitivity and specificity of ECG to identify high PVC burden on Holter was 72% and 93.6%, respectively, when utilizing a positive ECG result as one PVC or more, and 44% and 98.9%, respectively, with ≥3 PVCs on ECG. The positive likelihood ratio corresponding to ≥3 PVCs on ECG was 40. These findings demonstrate that the number of PVCs on ECG can be utilized for quick bedside estimation of high PVC burden. © 2017 Wiley Periodicals, Inc.

  13. AN INVESTIGATION OF THE IMPACT OF IMPURITIES ON THE MECHANICAL PROPERTIES OF RECYCLED PVC EXTRUSION PIPES

    OpenAIRE

    Adamu Alhaji Umar; Raji Olalere Fatai

    2007-01-01

    This work studied the effect of using recycled scraps in the production of rigid PVC extrusion pipe. Different formulations with varied percentages of scraps were extruded and various tests carried out on the sample specimen to determine their corresponding mechanical properties. It was finally discovered that among the two sources of scraps, the in-house scraps contained less impurities and blending about 10% of it with virgin PVC material in the production gave improved mechanical propertie...

  14. Thermal and catalytic decomposition behavior of PVC mixed plastic waste with petroleum residue

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Mohammad Farhat; Siddiqui, Mohammad Nahid [Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2005-08-15

    The pyrolysis and hydropyrolysis of PVC mixed plastic waste alone and with petroleum residue was carried out at 150 and 350{sup o}C under N{sub 2} gas and at 430{sup o}C under 6.5MPa H{sub 2} gas pressure. The behavior of plastic waste during thermal and catalytic decomposition has also been studied in single- and two-stage reaction processes. In the individual pyrolysis process, both the petroleum residue and polystyrene (PS) undergo more than 90% conversion to liquid and gaseous products, whereas low-density polyethylene (LDPE) and high-density polyethylene (HDPE) yielded lower conversions products, and polypropylene (PP) and polyvinyl chloride (PVC) afforded somewhere a moderate to high conversion products. In a single-stage pyrolysis reaction, PVC was processed with petroleum residue at 150 and 430{sup o}C, under N{sub 2} gas for 1h at each temperature in a glass reactor. The model PVC and waste PVC showed slight variations in the products distribution obtained from the glass reactor. In two-stage process, model PVC, vacuum gas oil (VGO) and a number of different catalysts were used in a stainless steel autoclave micro tubular reactor at 350{sup o}C under the stream of N{sub 2} gas for 1h and at 430{sup o}C under 950psi (6.5MPa) H{sub 2} pressure for the duration of 2h. Significantly, different products distributions were obtained. Among the catalysts used, fluid catalytic cracking (FCC) and hydrocracking catalysts (HC-1) were most effective in producing liquid fuel (hexane soluble) materials. The study shows that the catalytic coprocessing of PVC with VGO is a feasible process by which PVC and VGO materials can be converted into transportation fuels.

  15. Reduction of hexavalent chromium collected on PVC filters.

    Science.gov (United States)

    Shin, Y C; Paik, N W

    2000-01-01

    Chromium exists at various valences, including elemental, trivalent, and hexavalent chromium, and undergoes reduction-oxidation reactions in the environment. Since hexavalent chromium is known as a human carcinogen, it is most important to evaluate the oxidation-reduction characteristics of the hexavalent chromium species. Although hexavalent chromium can be reduced to trivalent state, the detailed information on this in workplace environments is limited. The purpose of this study was to investigate hexavalent chromium reduction in time in various conditions. A pilot chrome plating operation was prepared and operated in a laboratory for this study. There was evidence that the hexavalent chromium was reduced by time after mist generation. The percentage ratio (with 95% confidence intervals in parentheses) of hexavalent chromium to total chromium was almost 100% (99.1 approximately 102.3) immediately after mist generation, and was reduced to 87.4% (84.8 approximately 89.9) at 1 hour and 81.0% (78.3 approximately 83.5) at 2 hours, respectively. Another test indicated that hexavalent chromium collected on PVC filters was also reduced by time after sampling. Hexavalent chromium was reduced to 90.8% (88.2 approximately 93.3) at 2 hours after sampling. It also was found that hexavalent chromium was reduced during storage in air. It is recommended that air samples of hexavalent chromium be protected against reduction during storage.

  16. Efficiency analysis and assessment of interlocking PVC sheet piling walls

    International Nuclear Information System (INIS)

    Emam, A.A.

    2005-01-01

    The use of PVC sheet piling in marine environments offers a number of unique advantages that include weight saving, corrosion resistance and environmentally safe material. In this study, one of the widely used classical methods as well as a finite element analysis are used to analyze such sheet piling walls. The analysis focuses on the effect of some important parameters on the wall global behavior, bending moments, stresses and deflections. The parameters include wall cross-section, wall height, embedment depth, number and spacing of anchor rods, and type of soil and loading conditions. Furthermore, the effect of the shape of the wall cross-section and the location of the interlocking joints has been studied by using plane frame and arch-like models. Results indicate that the finite element modeling is an effective tool for numerical approximation of soil-structure interaction problems. The required theoretical embedment depth is nearly 30 % of the clear wall height. Also, the modulus of subgrade reaction has a minor effect on both cantilever wall and one anchor sheet-pile wall. Finally, lateral (horizontal) action shows that deep sections tend to behave like an arch under radial loading which might increase normal stresses at some critical sections

  17. Study on the effect of stabilizers on discoloring of PVC by irradiation

    International Nuclear Information System (INIS)

    Peng Chaorong; Wang Jingxia; Chen Zhuping; Liu Siyang

    2009-01-01

    Composites of polyvinyl chloride (PVC) filled with stabilizers was irradiated by 60 Co γ-ray. The effect of different stabilizers on the radiation-induced discoloring of PVC was investigated and the structures of irradiated PVC were characterized by ultraviolet spectrum (UV) and Fourrier transfer infrared spectrum (FT-IR). It shows that the stabilizers including calcium stearate/zinc stearate, epoxidised oil, phosphite and photostabilizer can improve the property of resistance to radiation-induced discoloring of PVC, and phosphite can improve the property of resistance to radiation-induced oxidation of PVC. Among the stabilizers, formulations with calcium stearate/zinc stearate show high transparency and excellent property of resistance to radiation at same absorbed dose. Change rate of yellow index of formulation (calcium stearate: zinc stearate=2:1) has been determined to be 8.3% at the absorbed dose of 30 kGy. It has been found that the structures of PVC with numbers of conjugated double bond or α, β-unsaturated ketone are formed after irradiation by γ-rays. (authors)

  18. Optimization of the thickness of a conducting polymer, polyaniline, deposited on the surface of poly(vinyl chloride) membranes: a new way to improve their potentiometric response.

    Science.gov (United States)

    Shishkanova, T V; Matejka, P; Král, V; Sedenková, I; Trchová, M; Stejskal, J

    2008-08-29

    Repeated depositions of polyaniline (PANI) have been used to control the thickness of the polymeric film deposited on poly(vinyl chloride) (PVC) membrane surface. The oxidation of aniline was carried out in a dispersion mode, i.e. in the presence of poly(N-vinylpyrrolidone) (PVP). Two kinds of PVC were used for this purpose: a non-plasticized PVC for the study of PANI deposition and PVC, plasticized with nitrophenyl octyl ether (NPOE), as a prototype of a liquid membrane electrode. The results of UV-visible and FTIR spectroscopies and electron microscopy showed that (1) the film thickness increased by about equal increments of approximately 40 nm after each polymerization, and (2) the interface with PVC was constituted by PANI film and adhering PANI-PVP colloidal particles. The various thicknesses of the deposited PANI films affected the potentiometric response of the NPOE/PVC membrane with and without an anion-exchanger. The potentiometric anionic response was observed with a minimal thickness of PANI film on the blank NPOE/PVC membrane. Sensitivity of the PANI film to pH occurred only with a blank NPOE/PVC membrane coated with a thick polymeric film, while it was strongly suppressed by the presence of a lipophilic anion-exchanger, tridodecylmethylammonium chloride (TDDMACl), in the membrane, regardless of the thickness of the polymer film. The thickness of the PANI film did not affect the anionic selectivity pattern of TDDMACl-based membranes to any great extent, but its presence improved and stabilized their potentiometric characteristics (sensitivity, linear-response range).

  19. Metamaterial membranes

    International Nuclear Information System (INIS)

    Restrepo-Flórez, Juan Manuel; Maldovan, Martin

    2017-01-01

    We introduce a new class of metamaterial device to achieve separation of compounds by using coordinate transformations and metamaterial theory. By rationally designing the spatial anisotropy for mass diffusion, we simultaneously concentrate different compounds in different spatial locations, leading to separation of mixtures across a metamaterial membrane. The separation of mixtures into their constituent compounds is critically important in biophysics, biomedical, and chemical applications. We present a practical case where a mixture of oxygen and nitrogen diffusing through a polymeric planar matrix is separated. This work opens doors to new paradigms in membrane separations via coordinate transformations and metamaterials by introducing novel properties and unconventional mass diffusion phenomena. (paper)

  20. Performance of different hollow fiber membranes for seawater desalination using membrane distillation

    KAUST Repository

    Francis, Lijo; Ghaffour, NorEddine; Alsaadi, Ahmad Salem; Amy, Gary L.

    2014-01-01

    Membrane distillation requires a highly porous hydrophobic membrane with low surface energy. In this paper, we compare the direct contact membrane distillation (DCMD) performances of four different types of in-house fabricated hollow fiber membranes and two different commercially available hollow fiber membranes. Hollow fiber membranes are fabricated using wet-jet phase inversion technique and the polymeric matrices used for the fabrication are polyvinylidine fluoride (PVDF) and polyvinyl chloride (PVC). Commercial hollow fiber membrane materials are made of polytetrafluoroethylene (PTFE) and polypropylene (PP). PVDF hollow fibers showed a superior performance among all the hollow fibers tested in the DCMD process and gave a water vapor flux of 31 kg m-2h-1 at a feed and coolant inlet temperatures of 80 and 20°C, respectively. Under the same conditions, the water vapor flux observed for PP, PTFE, and PVC hollow fiber membranes are 13, 11, and 6 kg m-2h-1, respectively, with 99.99% salt rejection observed for all membranes used.

  1. Performance of different hollow fiber membranes for seawater desalination using membrane distillation

    KAUST Repository

    Francis, Lijo

    2014-08-11

    Membrane distillation requires a highly porous hydrophobic membrane with low surface energy. In this paper, we compare the direct contact membrane distillation (DCMD) performances of four different types of in-house fabricated hollow fiber membranes and two different commercially available hollow fiber membranes. Hollow fiber membranes are fabricated using wet-jet phase inversion technique and the polymeric matrices used for the fabrication are polyvinylidine fluoride (PVDF) and polyvinyl chloride (PVC). Commercial hollow fiber membrane materials are made of polytetrafluoroethylene (PTFE) and polypropylene (PP). PVDF hollow fibers showed a superior performance among all the hollow fibers tested in the DCMD process and gave a water vapor flux of 31 kg m-2h-1 at a feed and coolant inlet temperatures of 80 and 20°C, respectively. Under the same conditions, the water vapor flux observed for PP, PTFE, and PVC hollow fiber membranes are 13, 11, and 6 kg m-2h-1, respectively, with 99.99% salt rejection observed for all membranes used.

  2. Estado de mistura e dispersão da fase borrachosa em blendas PVC/NBR Phase separation and rubber phase dispersion in PVC/NBR blends

    Directory of Open Access Journals (Sweden)

    Fábio R. Passador

    2006-01-01

    Full Text Available Termoplásticos modificados com elastômeros têm despertado grande interesse de pesquisadores e de indústrias devido à atraente relação custo/benefício e a possibilidade de aumento significativo da tenacidade sob impacto de polímeros frágeis com a incorporação de uma fase borrachosa dispersa. Este artigo mostra a relação entre o estado de mistura e a dispersão da fase borrachosa em blendas de poli (cloreto de vinila (PVC com borracha nitrílica (NBR. O estado de mistura de blendas poliméricas é um fator muito importante a ser considerado no desenvolvimento destes tipos de materiais, uma vez que determina o nível de mistura molecular das blendas. A característica estrutural do PVC é responsável pela morfologia das blendas PVC/NBR, sendo que há uma otimização de propriedades mecânicas quando as partículas de borracha formam a morfologia "pseudo-network", ou seja, quando as partículas de borracha estão randomicamente dispersas entre as partículas primárias do PVC.Thermoplastics modified with elastomers have attracted great interest of researchers and industries due to the low cost/benefit relationship and the possibility of significant increase in the toughness of brittle polymers through the incorporation of a dispersed rubber phase. This article shows the relationship between the interaction between phases and rubber phase dispersion in poly (vinyl chloride/nitrile rubber blends. The interaction between components in polymer blends is an important factor to be considered in the development of this kind of materials because it determines the level of the mixture at the molecular level. The particulate nature of PVC and the degree of nitrile groups in the NBR are responsible to the PVC/NBR blends morphologies leading to an optimization of the mechanical properties when the rubber particles form a pseudo-network morphology with the rubber particles randomly dispersed in between the PVC primary particles.

  3. Influence of iron substitution by selected rare-earth ions on the properties of NiZn ferrite fillers and PVC magneto-polymer composites

    Science.gov (United States)

    Ušák, Elemír; Ušáková, Mariana; Dosoudil, Rastislav; Šoka, Martin; Dobročka, Edmund

    2018-04-01

    Nickel-zinc ferrites are very important soft magnetic materials from the point of view of diverse technical applications (such as, e.g., various electronic devices and components) for their high magnetic permeability and permittivity, low core loss, high resistivity, high Curie temperature as well as mechanical strength and chemical stability. Due to their good absorbing properties, they can be used as microwave absorbing and shielding materials with the aim of decreasing the environmental pollution caused by non-ionizing microwave radiation. The ferrite material incorporated into the polymer matrix creates qualitatively new magneto-polymer composite material taking benefits from both components. The properties typical for polymers (elasticity, mouldability, etc.) are combined with good high-frequency magnetic parameters, thus allowing to utilize these materials, e.g., in high-frequency applications where especially flexibility of composite materials plays a key role. Small amounts of selected rare-earth (RE) ions, in particular Y3+, La3+, Eu3+ and Gd3+ have been embedded into the nickel-zinc ferrite that has been used as the magnetic filler in magnetic polymer composites with polyvinylchloride (PVC) acting as the polymeric matrix. The effect of various types of rare-earth ions on the structural as well as quasi-static and dynamic (electro)magnetic properties of the ferrite fillers as well as ferrite/PVC composites, in particular the frequency dispersion of the complex permeability, has been studied.

  4. Adenoviral vectors expressing fusogenic membrane glycoproteins activated via matrix metalloproteinase cleavable linkers have significant antitumor potential in the gene therapy of gliomas.

    Science.gov (United States)

    Allen, Cory; McDonald, Cari; Giannini, Caterina; Peng, Kah Whye; Rosales, Gabriela; Russell, Stephen J; Galanis, Evanthia

    2004-11-01

    Fusogenic membrane glycoproteins (FMG) such as the gibbon ape leukemia virus envelope (GALV) glycoprotein are potent therapeutic transgenes with potential utility in the gene therapy of gliomas. Transfection of glioma cell lines with FMG expression constructs results in fusion with massive syncytia formation followed by cytotoxic cell death. Nevertheless, ubiquitous expression of the GALV receptor, Pit-1, makes targeting desirable in order to increase the specificity of the observed cytopathic effect. Here we report on use of matrix metalloproteinase (MMP)-cleavable linkers to target the cytotoxicity of FMG-expressing adenoviral vectors against gliomas. Replication-defective adenoviruses (Ad) were constructed expressing the hyperfusogenic version of the GALV glycoprotein linked to a blocking ligand (C-terminal extracellular domain of CD40 ligand) through either an MMP-cleavable linker (AdM40) or a non-cleavable linker (AdN40). Both viruses also co-expressed the green fluorescent protein (GFP) via an internal ribosomal entry site. The glioma cell lines U87, U118, and U251 characterized by zymography and MMP-2 activity assay as high, medium and low MMP expressors, respectively, the MMP-poor cell lines TE671 and normal human astrocytes were infected with AdM40 and AdN40 at different multiplicities of infection (MOIs) from 1-30. Fusion was quantitated by counting both number and size of syncytia. Infection of these cell lines with AdN40 did not result in fusion or cytotoxic cell death, despite the presence of infection, as demonstrated by GFP positivity, therefore indicating that the displayed CD40 ligand blocked GALV-induced fusion. Fusion was restored after infection of glioma cells with AdM40 at an MOI as low as 1 to an extent dependent on MMP expression and coxsackie adenovirus receptor (CAR) expression in the specific cell line. Western immunoblotting demonstrated the presence of the cleaved CD40 ligand in the supernatant of fused glioma cells. Use of the MMP

  5. Near infrared reflectance spectroscopy for the fast identification of PVC-based films.

    Science.gov (United States)

    Laasonen, M; Rantanen, J; Harmia-Pulkkinen, T; Michiels, E; Hiltunen, R; Räsänen, M; Vuorela, H

    2001-07-01

    Near infrared (NIR) reflectance spectroscopy was used to develop a non-destructive and rapid qualitative method for the analysis of plastic films used by the pharmaceutical industry for blistering. Three types of films were investigated: 250 microm PVC [poly(vinyl chloride)] films, 250 microm PVC films coated with 40 g m(-2) of PVDC [poly(vinylidene dichloride)] and 250 microm PVC films coated with 5 g m(-2) of TE (Thermoelast) and 90 g m(-2) of PVDC. Three analyses were carried out using different pre-treatment options and a PLS (partial least squares) algorithm. Each analysis was aimed at identifying one type of film and rejecting all types of false sample (different thickness, colour or layer). True and false samples from four plastics manufacturers were included in the calibration sets in order to obtain robust methods that were suitable regardless of the supplier. Specificity was demonstrated by testing validation sets against the methods. The tests showed 0% of type I (false negative identification) and 1% of type II errors (false positive identification) for the PVC method, 13 and 3%, respectively, for the PVC-PVDC method and no error for the PVC-TE-PVDC method. Type II errors, mostly due to the slight sensitivity of the methods to film thickness, are easily corrected by simple thickness measurements. This study demonstrates that NIR spectroscopy is an excellent tool for the identification of PVC-based films. The three methods can be used by the pharmaceutical industry or plastics manufacturers for the quality control of films used in blister packaging.

  6. The role of chlorine and additives of PVC-plastic in combustion

    International Nuclear Information System (INIS)

    Mattila, H.

    1991-01-01

    The PVC differs from other common plastics due to the chlorine content. As the PVC is combusted, the chlorine is released mainly as hydrogen chloride. The content of chlorinated hydrocarbons is small, but these can also contain polychlorinated dibenzofuranes and dibenzodioxines, which are extremely poisonous. The aim of this study was to find out, what is the portion of PVC combustion in total emission of chlorinated hydrocarbons. Additionally, the amounts chlorine coming into combustion process with ordinary fuels have been estimated, and they are compared with the amounts of PVC. The chloride content of municipal wastes vary in between 0.4-0.9 %. The portion of plastics is about 30 % of the total, and the rest being from paper, food , wood and garden wastes an textiles. Both organic and inorganic chlorine form gaseous hydrogen chlorid in combustion processes. HCl can then react with oxygen and produce caseous chlorine. This can react with unreacted carbon of the smoke and produce different kinds of chlorinated hydrocarbons. The portion of PVC of the chlorine going into combustion in Finland has been estimated to be about 1-2 %. Combustion tests were made using coal and bark and plastic waste as additional fuel. It was noticed that addition of plastic decreased the amount of polyaromatic hydrocarbons in the smoke. Chlorinated dioxins and furans occurred a little less in the gases of combustion of plastic mixtures not containing PVC than in reference tests, but they increased when PVC containing plastic mixture was combusted, but more chlorinated dioxins and furans were absorbed into fly ash, so the emissions remained almost the same

  7. Preparation and characterization of a sulindac sensor based on PVC/TOA-SUL membrane.

    Science.gov (United States)

    Lenik, Joanna

    2014-04-01

    A potentiometric sulindac sensitive sensor based on tetraoctylammonium (Z)-5-fluoro-2-methyl-1-[[p-(methylsulfinyl)phenyl]methylene]-1H-indene-3-acetate (TOA-SUL) was described. The electrode responded with sensitivity of 57.5±1.6mV decade(-1) over the linear range 5×10(-5)-1×10(-2)mol L(-1) at pH6.0-9.0. It had the limit of detection 1.4×10(-5)mol L(-1), a fast response time of 13s and showed clear discrimination of sulindac ions from several inorganic and organic compounds and also amino acids. This electrode did not contain any inner solutions, so it was easy and comfortable to use. The proposed sensor was used to determine sulindac in clear solution and in urine sample solution. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Change Spectroscopic, thermal and mechanical studies of PU/PVC blends

    Energy Technology Data Exchange (ETDEWEB)

    Hezma, A.M. [Spectroscopy Department, Physics Division, National Research Center, Giza (Egypt); Elashmawi, I.S. [Spectroscopy Department, Physics Division, National Research Center, Giza (Egypt); Physic Department, Faculty of Science, Taibah University, Al-Ula (Saudi Arabia); Rajeh, A., E-mail: a.rajeh88@yahoo.com [Physic Department, Faculty of Science, Amran University, Sa' dah (Yemen); Physics Department, Faculty of science, Mansoura University, Mansoura (Egypt); Kamal, Mustafa [Physics Department, Faculty of science, Mansoura University, Mansoura (Egypt)

    2016-08-15

    Blends of polyurethane (PU) and polyvinyl chloride (PVC) with different concentrations were prepared by casting method. The effects of PU on PVC blends was examined by Fourier transform-infrared (FTIR), Ultra-violet visible studies (UV/VIS.), X-ray diffraction (XRD), Thermogravimetric (TGA), Differential scanning calorimetry (DSC), and mechanical properties (stress–strain curve). The interaction between PU and PVC was examined by FT-IR through the absorbance of the N–H groups and was correlated to mechanical/thermal properties. Ultra-violet visible said that optical energy gap decrease with increasing concentration of PU. Differential scanning calorimetry results was observed a single glass transition temperature (T{sub g}) for blends this confirming existence miscibility within the blends. The causes for best thermal stability of some blends may be described by measurements of interactions between C=O groups of PU and the α-hydrogen of PVC or a dipole–dipole –C=O..Cl–C– interactions. Significant alterations in FTIR, X-ray and DSC examination shows an interactions between blends had good miscibility. X-ray shows some alterations in the intensity with additional PU. PU change the mechanical behavior of PVC through of the blends. When polyurethane content increase causes polyvinyl chloride tensile strength decreases and elongation at break increase.

  9. Electrochemical Behaviour of Ni and Ni-PVC Electrodes for the Electroxidation of Ethanol

    International Nuclear Information System (INIS)

    Mohd Syafiq Hamdan; Norazzizi Nordin; Siti Fathrita Mohd Amir; Riyanto; Mohamed Rozali Othman

    2011-01-01

    In this study, two nickel based electrodes were prepared; nickel foil and nickel-polyvinylchloride (Ni-PVC), in order to study their electrochemical behavior using cyclic voltammetry, CV and chronocoulometry, CC. Ni electrode was prepared from Ni metal foil while Ni-PVC electrode was prepared by mixing a weighed portion of Ni powder and PVC in THF solvent, swirled until the suspension was homogeneous and drying the suspension in an oven at 50 degree Celsius for 3 h. The dry sample was then placed in a 1 cm diameter stainless steel mould and pressed at 10 ton/ cm 2 . From CV data, Ni-PVC electrode showed a better electrochemical behavior compared to Ni metal foil electrode. The use of Ni-PVC electrode at higher concentration of supporting electrolyte (1.0 M KOH) was better than at lower concentration of the same supporting electrolyte in electroxidation of ethanol. In addition to acetic acid, the oxidation of ethanol also produced ethyl acetate and acetaldehyde. (author)

  10. Preparation of Non-Woven Fiber Mats by Mixture of PVC and Epoxidized Natural Rubber

    International Nuclear Information System (INIS)

    Muhammad Hariz Othman; Mahathir Mohamed; Dahlan Mohd

    2014-01-01

    Eletrospun non-woven fibre mats prepared from ENR modified PVC were successfully fabricated at ambient temperature by electro spinning method. Liquid epoxidized natural rubber (LENR) was used because it is easier to handle compared to dried ENR. PVC was mixed with LENR based on 3 different ratios (9:1, 8:2 and 7:3). The effect of ENR on electrospinnibality of PVC was investigated.The morphologies and thermal properties of the electro span fibre mats were characterized and assessed using scanning calorimetry (DSC). The polymer solution concentration 16 aut % formed a diameter of the fibres were mainly affected by the addition of natural rubber and weight ratio of the solution. The diameter of the fibres also decreased with increasing amount of LENR in the solution. Thermal degradation involved two-step degradation with the first degradation representing the dehydro chlorination of PVC to form polyene and followed by the decomposition of LENR and the polyene.Addition of LENR into the sample caused the T g of electro spun fibre mats of PVC/LENR to shift toward lower temperature. (author)

  11. The structure of myristoylated Mason-Pfizer monkey virus matrix protein and the role of phosphatidylinositol-(4,5)-bisphosphate in its membrane binding.

    Science.gov (United States)

    Prchal, Jan; Srb, Pavel; Hunter, Eric; Ruml, Tomáš; Hrabal, Richard

    2012-10-26

    We determined the solution structure of myristoylated Mason-Pfizer monkey virus matrix protein by NMR spectroscopy. The myristoyl group is buried inside the protein and causes a slight reorientation of the helices. This reorientation leads to the creation of a binding site for phosphatidylinositols. The interaction between the matrix protein and phosphatidylinositols carrying C(8) fatty acid chains was monitored by observation of concentration-dependent chemical shift changes of the affected amino acid residues, a saturation transfer difference experiment and changes in (31)P chemical shifts. No differences in the binding mode or affinity were observed with differently phosphorylated phosphatidylinositols. The structure of the matrix protein-phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P(2)] complex was then calculated with HADDOCK software based on the intermolecular nuclear Overhauser enhancement contacts between the ligand and the matrix protein obtained from a (13)C-filtered/(13)C-edited nuclear Overhauser enhancement spectroscopy experiment. PI(4,5)P(2) binding was not strong enough for triggering of the myristoyl-switch. The structural changes of the myristoylated matrix protein were also found to result in a drop in the oligomerization capacity of the protein. Copyright © 2012. Published by Elsevier Ltd.

  12. Improving the Healthiness of Sustainable Construction: Example of Polyvinyl Chloride (PVC

    Directory of Open Access Journals (Sweden)

    Emina Kristina Petrović

    2018-02-01

    Full Text Available With the increasing emphasis on sustainable construction, it has become important to better understand the impacts of common materials. This is especially paramount with the introduction of the United Nations (UN Sustainable Development Goals (SDGs which call for more comprehensive evaluations, adding many aspects of social consideration to the issues of environmental sustainability, including human health. Polyvinyl chloride (PVC/vinyl can be seen as a material with potential for significant adverse effects on a multiplicity of levels, and the construction industry is its single most significant consumer. This article presents a transdisciplinary review of adverse health impacts associated with PVC showing a number of issues: some that could be eliminated through design, but also some which appear inherent to the material itself and therefore unavoidable. The totality of issues revealed in relation to PVC presents a compelling case for a call for complete elimination of use of this material in sustainable construction.

  13. COMPORTAMIENTO DE UN CEMENTO ASFÁLTICO MODIFICADO CON UN DESECHO DE PVC

    Directory of Open Access Journals (Sweden)

    Fredy Alberto Reyes Lizcano

    2013-06-01

    Full Text Available Las propiedades físicas y reológicas a altas temperaturas de servicio de un cemento asfáltico (CA modificado con un desecho de policloruro de vinilo (PVC fueron evaluadas y son presentadas en el artículo. Adicionalmente se presenta la influencia del tiempo de mezcla del CA con el PVC y el envejecimiento a corto plazo. Un incremento notable en la rigidez y la resistencia a fluir se reporta cuando se adiciona el desecho de PVC a un CA 80-100. De la misma forma, se reporta un incremento en la temperatura máxima de operación en servicio del ligante modificado.

  14. Model fire tests on polyphosphazene rubber and polyvinyl chloride (PVC)/nitrile rubber foams

    Science.gov (United States)

    Widenor, W. M.

    1978-01-01

    A video tape record of model room fire tests was shown, comparing polyphosphazene (P-N) rubber and polyvinyl chloride (PVC)/nitrile rubber closed-cell foams as interior finish thermal insulation under conditions directly translatable to an actual fire situation. Flashover did not occur with the P-N foam and only moderate amounts of low density smoke were formed, whereas with the PVC/nitrile foam, flashover occurred quickly and large volumes of high density smoke were emitted. The P-N foam was produced in a pilot plant under carefully controlled conditions. The PVC/nitrile foam was a commercial product. A major phase of the overall program involved fire tests on P-N open-cell foam cushioning.

  15. Physicomechanical properties of PVC radiation-modified by tridecaethyleneglycol methacrylic ester

    International Nuclear Information System (INIS)

    Lomonosova, N.V.

    1988-01-01

    A study was made on physicomechanical properties of radiation-modified system on the basis of PVC and TGM-13 oligomer (dimethacrylic ester of tridecaethyleneglycol, 43.2%). Main physical properties of the composition (maximal stresses, softening point, double refraction value, activation energy, temperature positions of the first and the second maximums on isometric heating diagram) were used to determine its isotropic and oriented states, depending on absorbed radiation dose (0-128 kGy). It is shown that radiation PVC modification by TGM-13 oligomer results in formation of linked 'soft' plastic. In terms of strength it is on a par with isotropic linear PVC, but compare favourably with it with respect to t ρ and ε

  16. Degradation behavior of PVC film in aqueous solution at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Shun-Myung; Kim, Jong-Hwa; Lee, Soo [Changwon National University, Changwon(Korea)

    2001-02-28

    The heat treatment of PVC film containing PVC 65%, DOP (Dioctyl Phthalate) 32% as plasticizer, Ca-Zn stearates and surface agent was performed under several conditions to study the dehydrochlorination of PVC and char production. In the case of H{sub 2}SO{sub 4}, the dehydrochlorination was ca.100% at 250 deg.C for 3h. The char involving the smaller pores was produced with hydrothermal treatment. The pore size became small with increasing the treatment time and temperature. In the case of treatment with Ca(OH){sub 2}, the sizes of pores produced in char were about sever {approx}10 {mu}m at 225 deg.C for 12h. In the case of H{sub 2}SO{sub 4}, the size of pores were about 1 {mu}m in 5M H{sub 2}SO{sub 4} for 12h. (author). 6 refs., 3 tabs., 11 figs.

  17. Effects of low dose gamma irradiation on PVC blood bags containing anticoagulant CPDA solution

    International Nuclear Information System (INIS)

    Mitra, D.; Varshney, Lalit; Arjun, Chanda

    2006-01-01

    PVC blood bags were exposed to 20Gy and 60Gy low gamma radiation dose to investigate possibility of change in leaching behavior of the plasticizer into CPDA solution and the blood. Reversed phase HPLC was used for the investigations on anti coagulant solution CPDA(citrate, phosphate, dextrose and adenine) contained in PVC bag before and after gamma irradiation. The studies were repeated using methanol as an extractant instead of CPDA solution, considering higher extractability of plasticizer by blood. Irradiation of PVC bags by gamma radiation for a dose up to 60Gy does not lead to change in leaching behavior of the plasticizer in CPDA solution and methanol indicating similar expected behavior in blood. (author)

  18. Structural, optical and thermal characterization of PVC/SnO2 nanocomposites

    Science.gov (United States)

    Taha, T. A.; Ismail, Z.; Elhawary, M. M.

    2018-04-01

    The structural, optical, and thermal properties of PVC/SnO2 nanocomposites were investigated. XRD patterns were used to explore the structures of these prepared samples. Optical UV-Vis measurements were analyzed to calculate the spectroscopic optical constants of the prepared PVC/SnO2 nanocomposites. Both direct and indirect optical band gaps decreased with increasing SnO2 content. The refractive index, high frequency dielectric constant, plasma frequency, and optical conductivity values increased with SnO2. The single oscillator energy increased from 5.64 to 10.97 eV and the dispersion energy increased from 6.35 to 19.80 eV with the addition of SnO2. The other optical parameters such as optical moments, single oscillator strength, volume energy loss, and surface energy loss were calculated for different SnO2 concentrations. Raman spectra of the PVC/SnO2 nanocomposite films revealed the characteristic vibrational modes of PVC and surface phonon modes of SnO2. The thermal stability of PVC/SnO2 nanocomposite films was studied using DTA and thermogravimetric analysis. The glass transition ( T g) values abruptly changed from 46 °C for PVC to an average value of 59 °C for the polymer films doped with 2.0, 4.0, and 6.0 wt% SnO2. The weight loss decreased as the SnO2 concentration increased in the temperature range of 350-500 °C, corresponding to enhanced thermal stability.

  19. Estudo do comportamento de compostos de PVC com adição de amido Study of the behavior of PVC compounds with added starch

    Directory of Open Access Journals (Sweden)

    Lisandra Abatti

    2011-01-01

    Full Text Available Este trabalho apresenta o estudo do comportamento de compostos de PVC com adição de amido para aplicação especialmente na indústria calçadista. As propriedades mecânicas dos compostos nas proporções de 5, 7,5 e 10% foram estudadas através de ensaios de tração. Também foram verificados os índices de fluidez, alterações de propriedades quando submetidos ao envelhecimento artificial em estufa e natural ao expor às intempéries e enterrar no solo. A viabilidade da aplicação na indústria calçadista foi feita por injeção em gáspeas e tiras de sandálias, com testes de resistência, flexão e testes de campo. Os resultados demonstraram que o acréscimo de amido ao PVC provoca perda nas propriedades mecânicas, justificado pela baixa resistência mecânica do amido em relação ao PVC. Após envelhecimento em estufa o processo de retrogradação do amido deixa os compostos mais rígidos e com menor fluidez. Quando expostos às intempéries e ao solo, o PVC pode ser degradado com perda de HCl, o que leva à acidificação do solo. Nas aplicações em calçados e sandálias a resistência mecânica não atende aos requisitos do mercado. Apesar do baixo custo, o fraco comportamento mecânico dificulta sua viabilização para substituição em escala.This paper deals with the behavior of PVC compounds with addition of starch for applications, especially in the footwear industry. The mechanical properties of the compounds in the proportions of 5, 7.5 and 10% were studied using tensile tests. Also investigated were the flow rates, in addition to changes in properties when the material was subjected to artificial aging in an oven and exposed to natural weather and buried in the soil. The feasibility of application in the industry was evaluated with tests of endurance, strength and field tests in injection uppers and straps of sandals. The results showed that the addition of starch to PVC causes loss of mechanical properties, owing to

  20. Producción y modelamiento de gliceril-ésteres como plastificantes para PVC / Production et modelisation de glycerol-esters comme plastifiants pour le PVC

    OpenAIRE

    Suárez Palacios, Oscar Yesid

    2011-01-01

    El aumento en la producción mundial de glicerina, debido al crecimiento en el uso de biodiesel, y la tendencia a reemplazar los plastificantes derivados del anhídrido ftálico en la industria del PVC, por la toxicidad de dichas sustancias, motivaron la investigación de la plastificación del PVC con gliceril-ésteres derivados de ácidos carboxílicos de cadena corta (C3 - C8) y aromáticos. En este estudio se aplicó una metodología de diseño de producto para abordar la solución a las problemáticas...

  1. Effects of 60 MeV C5+ ion irradiation on PmT-PVC and p-TSA doped PoT-PVC blends

    International Nuclear Information System (INIS)

    Lakshmi, G.B.V.S.; Siddiqui, Azher M.; Ali, Vazid; Kulriya, Pawan K.; Zulfequar, M.

    2008-01-01

    Poly(m-toluidine) (PmT) and Poly(o-toluidine) (PoT) have been synthesized from derivatives of aniline (m-toluidine), (o-toluidine) monomers by chemical oxidative polymerization method. After polymerization, PoT powder was doped with p-toluene sulphonic acid (p-TSA) and the polymer powders were blended with poly vinyl chloride (PVC) to achieve PmT and p-TSA doped PoT dispersed films. XRD, FTIR and UV-visible studies were carried out to get their structural changes and optical information. These blends were irradiated by 60 MeV C 5+ ions with different fluences. Post Irradiation XRD, FTIR and UV-visible spectroscopy were also performed on all films. On p-TSA doped PoT-PVC blends dc-conductivity measurements are also carried out before and after irradiation. The results show structural modifications which lead to changes in optical and electrical properties

  2. Effect of PVC on ionic conductivity, crystallographic structural, morphological and thermal characterizations in PMMA-PVC blend-based polymer electrolytes

    International Nuclear Information System (INIS)

    Ramesh, S.; Liew, Chiam-Wen; Morris, Ezra; Durairaj, R.

    2010-01-01

    In this paper, temperature dependence of ionic conductivity, crystallographic structural, morphological and thermal characteristics of polymer blends of PMMA and PVC with lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) as a dopant salt are investigated. The study on the temperature dependence of ionic conductivity shows that these polymer blends exhibit Arrhenius behavior. The highest ionic conductivity was achieved when 70 wt% of PMMA was blended with 30 wt% of PVC. X-ray diffraction (XRD) and scanning electron microscopy (SEM) reveal the amorphous nature and surface morphology of polymer electrolytes, respectively. In DSC analysis it was found that the glass transition temperature (T g ) and melting temperature (T m ) decreased, whereas the decomposition temperature (T d ) increased. In contrast, the shift towards higher decomposition temperature and decrease in weight loss of polymer electrolytes, in TGA studies, indicates that the thermal stability of polymer electrolytes improved.

  3. Effect of PVC on ionic conductivity, crystallographic structural, morphological and thermal characterizations in PMMA-PVC blend-based polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh, S., E-mail: rameshtsubra@gmail.com [Centre for Ionics University Malaya, Department of Physics, Faculty of Science, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Liew, Chiam-Wen; Morris, Ezra; Durairaj, R. [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Setapak, 53300 Kuala Lumpur (Malaysia)

    2010-11-20

    In this paper, temperature dependence of ionic conductivity, crystallographic structural, morphological and thermal characteristics of polymer blends of PMMA and PVC with lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) as a dopant salt are investigated. The study on the temperature dependence of ionic conductivity shows that these polymer blends exhibit Arrhenius behavior. The highest ionic conductivity was achieved when 70 wt% of PMMA was blended with 30 wt% of PVC. X-ray diffraction (XRD) and scanning electron microscopy (SEM) reveal the amorphous nature and surface morphology of polymer electrolytes, respectively. In DSC analysis it was found that the glass transition temperature (T{sub g}) and melting temperature (T{sub m}) decreased, whereas the decomposition temperature (T{sub d}) increased. In contrast, the shift towards higher decomposition temperature and decrease in weight loss of polymer electrolytes, in TGA studies, indicates that the thermal stability of polymer electrolytes improved.

  4. Dosimetry of the JS-6500 industrial irradiator for the irradiation of the PVC graduated flasks; Dosimetria del irradiador industrial JS-6500 para la irradiacion de probetas de PVC

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda F, A.; Carrasco A, H.; Martinez P, M.E. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The dosimetry of the JS-6500 AECL irradiator was realized, outside of the industrial transportation rails to know the dose distribution, as well as its dose speed. This one with the intention of exposing to gamma radiation; plastified PVC graduated flasks and evaluating their interweavement or degradation or both. This study of dosimetry was carried out by means of a theoretical and experimental evaluation in air atmosphere. The results allow to know the irradiation conditions of the PVC graduated flasks as well as those results prove that has not a significant difference among the obtained result as theoretical as experimentally due to that the obtained result in the theoretical evaluation is 2.62 KGy/h and the result for the case of the experimental evaluation is 2.74 KGy/h. (Author)

  5. Electron beam processing of PVC insulating material in presence of additives

    International Nuclear Information System (INIS)

    Sharma, V.K.; Bhattacharyya, P.K.

    1994-01-01

    Using electron beam radiation flexible PVC (polyvinyl chloride) was cross linked in the dose range up to 15 Mrad. The effect of sensitizers and other additives on the cross linking and other physical properties like tensile strength have been investigated. It has been found that tri functional sensitizer like TMPTM (tri methyl propane tri methacrylate) is better sensitizer for PVC. In presence of TMPTM the physical properties related to crosslinking are found to be better than some of the other sensitizers used. The results are discussed. (author). 2 refs., 2 figs

  6. MECHANICAL, ELECTRICAL, AND THERMAL PROPERTIES OF MALEIC ANHYDRIDE MODIFIED RICE HUSK FILLED PVC COMPOSITES

    OpenAIRE

    Navin Chand; Bhajan Das Jhod

    2008-01-01

    Unmodified and modified rice husk powder filled PVC composites were prepared having different amounts of rice husk powder. Mechanical, thermal, and electrical properties of these composites were determined. The tensile strength of rice husk powder PVC composites having 0, 10, 20, 30, and 40 weight percent of rice husk powder was found to be 33.9, 19.4, 18.1, 14.6, and 9.5 MPa, respectively. Adding of maleic anhydride- modified rice husk powder improved the tensile strength of rice husk powder...

  7. Excellent impact performance of PVC pipeline materials in gas distribution networks after many years of service (CD-rom)

    NARCIS (Netherlands)

    Visser, Roy; Hermkens, R.M.J.; Wolters, Mannes; Weller, J.; Warnet, Laurent; Beckervordersandforth, C.; Verberg, G.H.B.; Kramer, M.

    2008-01-01

    It has been about fifty years ago since the first unplasticized poly(vinyl chloride) (uPVC) pipes were installed for use in gas distribution purposes. Currently, about 22,500 km of uPVC is still in use in the Dutch gas distribution network. The pipes were originally designed for a lifetime of 50

  8. Thermal stability of formulations of PVC irradiated with {gamma} of {sup 60}; Estabilidad termica de formulaciones de PVC irradiadas con {gamma} de {sup 60} Co

    Energy Technology Data Exchange (ETDEWEB)

    Martinez P, M.E.; Carrasco A, H. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: memp@nuclear.inin.mx; Castaneda F, A.; Benavides C, R.; Garcia R, S.P. [CIQA, 25100 Saltillo, Coahuila (Mexico)

    2004-07-01

    The industry of cables and wires frequently use cable isolations with base of formulations of PVC, in those that stabilizer has usually been used with the help of heavy metals, as the lead, which is toxic. To solve the problem, from the 2002 one has come studying in combined form in the National Institute of Nuclear Research ININ and the Center of Investigation in Applied Chemistry CIQA, the modifications induced by the radiation in formulations with the help of vinyl poly chloride PVC. In these formulations, prepared with cross linking agent, plastifying industrial grade, stuff and non toxic stabilizers of calcium estearate and zinc industrial grade, it is sought to replace the stabilizer of Pb. For this were irradiated it test tubes of PVC with gamma radiation of cobalt 60 to three different dose in atmospheres of air and argon. Later it was determined their thermal stability at different times of heating and it was measured the Young modulus by means of thermo mechanical analysis. Those results obtained together with other techniques of characterization suggest that the irradiated proposed formulation can substitute the one stabilized with lead. (Author)

  9. Observation of Fermi Arc Surface States Induced by Organic Memristive/Memcapacitive Devices with a Double-Helical Polarized Single-Wall Nanotube Membrane for Direct Chelating with Matrix Matelloproteinase-2

    Directory of Open Access Journals (Sweden)

    E. T. CHEN

    2017-07-01

    Full Text Available Matrix Matelloproteinase-2 (MMP-2 plays a key role in many diseases. A new type of dual-functioning device was developed for fast, direct ultrasensitive detection of MMP-2. We report a memristive/memcapacitive device with vertex double-helical polarized biomimetic protein nanotubules forming double membranes with potential gradient mimicking mitochondria’s inner double membrane has developed. We also report Fermi arcs with nodes on the surface of the nanostructured membrane was observed at the first time by using a 3D real-time - energy-current dynamic mapping method based on data obtained from the Cyclic Voltammetry (CV method. The memristive/memcapacitive device comprises a cross- linked organic polymer having single-wall cross-bar polarized nanotube self-assembling membrane (SAM on a gold chip, under an applied potential, a pair of vertex double- helical circular current flow induced the Fermi arcs states occurrence and these Fermi arcs promoted a direct chelating with zinc ions of the MMP-2 to become possible without any antibody, tracer, or reagent used at room temperature was accomplished. We observed the pair of Dirac Cones became alignment and strengthened with each other in the presence of MMP-2 compared without MMP-2. The MMP-2 can be detected with ag/mL level sensitivity and the value of Detection of Limits (DOL reached orders of magnitude lower than published reports with simplified procedures by a Chronoamperometry (CA method and a Double Step Chronopotentiometry (DSCPO method using NIST SRM 965A standard human serum, respectively. The results show a feasible application for developing the commercial fast and real-time MMP monitoring devices for various diseases.

  10. Influence of Filler Pore Structure and Polymer on the Performance of MOF-Based Mixed-Matrix Membranes for CO2 Capture

    KAUST Repository

    Sabetghadam, Anahid

    2018-03-24

    To gain insight into the influence of metal-organic framework (MOF) fillers and polymers on membrane performance, eight different composites were studied by combining four MOFs and two polymers. MOF materials (NH-MIL-53(Al), MIL-69(Al), MIL-96(Al) and ZIF-94) with various chemical functionalities, topologies, and dimensionalities of porosity were employed as fillers, and two typical polymers with different permeability-selectivity properties (6FDA-DAM and Pebax) were selected as matrices. The best-performing MOF-polymer composites were prepared by loading 25wt% of MIL-96(Al) as filler, which improved the permeability and selectivity of 6FDA-DAM to 32 and 10%, while for Pebax they were enhanced to 25 and 18%, respectively. The observed differences in membrane performance in the separation of CO from N are explained on the basis of gas solubility, diffusivity properties, and compatibility between the filler and polymer phases.

  11. Influence of Filler Pore Structure and Polymer on the Performance of MOF-Based Mixed-Matrix Membranes for CO2 Capture

    KAUST Repository

    Sabetghadam, Anahid; Liu, Xinlei; Benzaqui, Marvin; Gkaniatsou, Effrosyni; Orsi, Angelica; Lozinska, Magdalena M.; Sicard, Clemence; Johnson, Timothy; Steunou, Nathalie; Wright, Paul A.; Serre, Christian; Gascon, Jorge; Kapteijn, Freek

    2018-01-01

    To gain insight into the influence of metal-organic framework (MOF) fillers and polymers on membrane performance, eight different composites were studied by combining four MOFs and two polymers. MOF materials (NH-MIL-53(Al), MIL-69(Al), MIL-96(Al) and ZIF-94) with various chemical functionalities, topologies, and dimensionalities of porosity were employed as fillers, and two typical polymers with different permeability-selectivity properties (6FDA-DAM and Pebax) were selected as matrices. The best-performing MOF-polymer composites were prepared by loading 25wt% of MIL-96(Al) as filler, which improved the permeability and selectivity of 6FDA-DAM to 32 and 10%, while for Pebax they were enhanced to 25 and 18%, respectively. The observed differences in membrane performance in the separation of CO from N are explained on the basis of gas solubility, diffusivity properties, and compatibility between the filler and polymer phases.

  12. Novel modified poly vinyl chloride blend membranes for removal of heavy metals from mixed ion feed sample

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, Vignesh; Jyothi, M.S. [Centre for Nano and Material Sciences, Jain University, Jain Global Campus, Kanakapura Ramanagaram, Bangalore, 562112 (India); Balakrishna, R. Geetha, E-mail: br.geetha@jainuniversity.ac.in [Centre for Nano and Material Sciences, Jain University, Jain Global Campus, Kanakapura Ramanagaram, Bangalore, 562112 (India); Padaki, Mahesh, E-mail: sp.mahesh@jainuniversity.ac.in [Centre for Nano and Material Sciences, Jain University, Jain Global Campus, Kanakapura Ramanagaram, Bangalore, 562112 (India); National University of Science and Technology “MISIS”, Moscow, 119049 (Russian Federation); Deon, Sebastien [Institut UTINAM, UMR CNRS 6213, Université de Bourgogne-Franche-Comté,16 route de Gray, Besançon Cedex 25030 (France)

    2017-06-05

    Highlights: • Work reports the novel modification of poly vinyl chloride (PVC) using newly developed method. • Blend membranes were prepared using modified PVC and polysulfone in different compositions. • The prepared blend membranes were used for separation of different heavy metal ions. • The blend membranes showed improved rejection of heavy metal ions in comparison to Commercial NF 270 membrane. - Abstract: Herein, an attempt has been made to prepare a novel membrane with good efficiency for removal of heavy metal ions namely lead (Pb), cadmium (Cd) and chromium (Cr). 4-amino benzoic acid (ABA) was covalently grafted onto the poly vinyl chloride (PVC) backbone by C−N bond to enhance the hydrophilicity. {sup 1}H NMR and ATR-IR spectroscopy analysis confirmed the chemical modification of PVC. Further the modified polymer was blended in different compositions with polysulfone (PSf) for optimization. Morphological changes that occurred in blend membranes, due to the incorporation of modified PVC was studied by AFM and SEM techniques. The effect on hydrophilicity and performance of blends owing to incorporation of modified PVC was evaluated by water uptake, contact angle and flux studies. The density of functional groups in blends was analyzed by its ion-exchange capacity. Batch wise filtration of metal ions was carried out and the effect of pressure, feed pH and interference of ions was thoroughly investigated. Essentially, 100% rejection was obtained for all the metal ions in acidic pH with a productivity of 2.56 l/m{sup 2} h. The results were correlated with the results of commercially available NF 270 membrane under the same operating conditions.

  13. Novel modified poly vinyl chloride blend membranes for removal of heavy metals from mixed ion feed sample

    International Nuclear Information System (INIS)

    Nayak, Vignesh; Jyothi, M.S.; Balakrishna, R. Geetha; Padaki, Mahesh; Deon, Sebastien

    2017-01-01

    Highlights: • Work reports the novel modification of poly vinyl chloride (PVC) using newly developed method. • Blend membranes were prepared using modified PVC and polysulfone in different compositions. • The prepared blend membranes were used for separation of different heavy metal ions. • The blend membranes showed improved rejection of heavy metal ions in comparison to Commercial NF 270 membrane. - Abstract: Herein, an attempt has been made to prepare a novel membrane with good efficiency for removal of heavy metal ions namely lead (Pb), cadmium (Cd) and chromium (Cr). 4-amino benzoic acid (ABA) was covalently grafted onto the poly vinyl chloride (PVC) backbone by C−N bond to enhance the hydrophilicity. 1 H NMR and ATR-IR spectroscopy analysis confirmed the chemical modification of PVC. Further the modified polymer was blended in different compositions with polysulfone (PSf) for optimization. Morphological changes that occurred in blend membranes, due to the incorporation of modified PVC was studied by AFM and SEM techniques. The effect on hydrophilicity and performance of blends owing to incorporation of modified PVC was evaluated by water uptake, contact angle and flux studies. The density of functional groups in blends was analyzed by its ion-exchange capacity. Batch wise filtration of metal ions was carried out and the effect of pressure, feed pH and interference of ions was thoroughly investigated. Essentially, 100% rejection was obtained for all the metal ions in acidic pH with a productivity of 2.56 l/m 2 h. The results were correlated with the results of commercially available NF 270 membrane under the same operating conditions.

  14. Tratamento químico superficial e metalização de ABS, PVC e blendas de PVC/ABS

    Directory of Open Access Journals (Sweden)

    Ana Paula Kurek

    2015-04-01

    Full Text Available Visando à substituição do ABS em peças cromadas, amostras de PVC e blendas de PVC/ABS, na razão mássica de 20/80, 40/60 e 60/40, foram submetidas ao pré-tratamento em solução sulfocrômica sob diferentes condições de concentração, tempo e temperatura e sendo em seguida cromadas. As modificações na superfície das peças após o condicionamento foram analisadas por microscopia eletrônica de varredura, microscopia de força atômica e rugosidade. A qualidade da deposição metálica foi avaliada por inspeção visual e teste de adesão. Os resultados mostraram que, aumentando a concentração de PVC nas peças necessitou-se de condições operacionais mais agressivas, tais como maiores temperaturas de banho, tempo de imersão e concentração de solução sulfocrômica para que ocorresse a adesão da camada metálica. De todas as condições testadas com a solução condicionante sulfocrômica no tratamento das peças de PVC e blendas PVC/ABS de 20/80 e 40/60, a concentração de 350 g/L de ácido crômico e 400 g/L de ácido sulfúrico, temperatura de 70°C e tempo de imersão de 15 minutos, ocasionou deposição do metal em toda a superfície das peças, as quais foram aprovadas nos testes de adesão e corrosão.

  15. Properties of commercial PVC-films with respect to electron dosimetry

    International Nuclear Information System (INIS)

    Miller, A.; Liqing, X.

    1985-05-01

    The properties of three commercially available polyvinyl chloride (PVC) film supplies and one made without additives were tested with respects to their application as routine dose monitors at electron accelerators. Dose fractionation was found to increase the response and the post-irradiation heat treatment was very critical for some of the films. (author)

  16. Migration from PVC cling films compared with their field of application

    DEFF Research Database (Denmark)

    Petersen, Jens Højslev; Lillemark, L.; Lund, L.

    1997-01-01

    Samples of PVC cling films were taken at importers, wholesalers and retail shops, and their overall migration to the alternative food simulant iso-octane was measured, after establishment of a correlation between overall migration to olive oil at 40 degrees C in 10 days and to iso-octane in 2 h...

  17. Investigation of PVC physical ageing in field test specimens using ultrasonic and dielectric measurements

    NARCIS (Netherlands)

    Demcenko, A.; Ravanan, M.; Visser, Roy; Loendersloot, Richard; Akkerman, Remko

    2013-01-01

    Physical ageing in PVC is studied using two techniques: a) non-linear ultrasonic measurements based on the non-collinear wave interaction theory and b) dielectric measurements. The ultrasonic measurement results are compared with dielectric measurement results. The comparison shows that the used

  18. Photoetching of Immobilized TiO2-ENR50-PVC Composite for Improved Photocatalytic Activity

    Directory of Open Access Journals (Sweden)

    M. A. Nawi

    2012-01-01

    Full Text Available Commercially acquired TiO2 photocatalyst (99% anatase powder was mixed with epoxidized natural rubber-50 (ENR50/polyvinyl chloride (PVC blend by ultrasonication and immobilized onto glass plates as TiO2-ENR50-PVC composite via a dip-coating method. Photoetching of the immobilized TiO2-ENR50-PVC composite was investigated under the irradiation of a 45 W compact fluorescent lamp and characterized by chemical oxygen demand (COD analysis, scanning electron microscopy-energy dispersive X-ray (SEM-EDX spectrometry, thermogravimetry analysis (TGA, and fourier transform infrared (FTIR spectroscopy. The BET surface area of the photoetched TiO2 composite was observed to be larger than the original TiO2 powder due to the systematic removal of ENR50 while PVC was retained within the composite. It also exhibited better photocatalytic efficiency than the TiO2 powder in a slurry mode and was highly reproducible and reusable. More than 98% of MB removal was consistently achieved for 10 repeated runs of the photo-etched photocatalyst system. About 93% of the 20 mg L−1 MB was mineralized over a period of 480 min. The presence of SO42−, NO3−, and Cl− anions was detected in the mineralized solution where the solution pH was reduced from 7 to 4.

  19. CORRELATION OF THE GLASS TRANSITION TEMPERATURE OF PLASTICIZED PVC USING A LATTICE FLUID MODEL

    Science.gov (United States)

    A model has been developed to describe the composition dependence of the glass transition temperature (Tg) of polyvinyl chloride (PVC) + plasticizer mixtures. The model is based on Sanchez-Lacombe equation of state and the Gibbs-Di Marzio criterion, which states that th...

  20. Enhanced Design of a Soft Thin-Film Vibrotactile Actuator Based on PVC Gel

    Directory of Open Access Journals (Sweden)

    Won-Hyeong Park

    2017-09-01

    Full Text Available We fabricated a soft thin-film vibrotactile actuator, which can be easily inserted into wearable devices, based on an electroactive PVC gel. One of the most important factors in fabricating a soft and thin vibrotactile actuator is to create vibrational force strong enough to stimulate human skin in a wide frequency range. To achieve this, we investigate the working principle of the PVC gel and suggest a new structure in which most of electric energy contributes to the deformation of the PVC gel. Due to this structure, the vibrational amplitude of the proposed PVC gel actuator could considerably increase (0.816 g (g = 9.8 m/s2 at resonant frequency. The vibrotactile amplitude is proportional to the amount of input voltage. It increased from 0.05 g up to 0.416 g with increasing applied voltages from 200 V to 1 kV at 1 Hz. The experimental results show that the proposed actuator can create a variety of haptic sensations.

  1. Synthesis of AzPhchitosan-bifenthrin-PVC to protect cables against termites.

    Science.gov (United States)

    Zhang, Lingkun; Cai, Weiwei; Chen, Wu-Ya; Zhang, Li; Hu, Kaikai; Guan, Yan-Qing

    2016-03-30

    The destruction of PVC cables by termites is a continuing and long-standing problem, which can lead to power leakage and power cut. Given the environmental demerits of insecticide overuse, alternative methods of addressing this problem are a highly desirable goal. In this study, we used photo-immobilization to develop a chitosan carrier system to help bifenthrin immobilize on the surface of the PVC substrate. The immobilization was analyzed using nuclear magnetic resonance (NMR), UV absorption, reverse-phase high-performance liquid chromatography (RP-HPLC), Raman absorption spectroscopy, and thermal gravimetric analysis (TGA). The surface structure and biological activity of the embedded and immobilized bifenthrin were examined using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photon-electron spectroscopy (XPS). Its efficacy was assessed in pest experiments. The results indicate a successful embedding and immobilization of bifenthrin. Furthermore, the chemical bonding network between AzPhchitosan, bifenthrin, and PVC is stable, guaranteeing no environmental release of bifenthrin, and also providing more efficacious protection against termites. The evidence suggests that this photo-immobilization of bifenthrin-embedded chitosan on the surface of PVC substrates is a novel and environmentally friendly technique for termite control. This paper also reports a modification of chitosan with respect to its novel application in environmental protection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Construction and demolition waste as a source of PVC for recycling.

    Science.gov (United States)

    Prestes, Sabrina Moretto Darbello; Mancini, Sandro Donnini; Rodolfo, Antonio; Keiroglo, Raquel Carramillo

    2012-02-01

    Construction and demolition waste can contain considerable amounts of polyvinyl chloride (PVC). This paper describes a study of the recycling of PVC pipes collected from such waste materials. In a sorting facility for the specific disposal of construction and demolition waste, PVC was found to represent one-third of the plastics separated by workers. Pipes were sorted carefully to preclude any possible contamination by poly(ethylene terephthalate) (PET) found in the waste. The material was ground into two distinct particle sizes (final mesh of 12.7 and 8 mm), washed, dried and recycled. The average formulation of the pipes was determined based on ash content tests and used in the fabrication of a similar compound made mainly of virgin PVC. Samples of recycled pipes and of compound based on virgin material were subjected to tensile and impact tests and provided very similar results. These results are a good indication of the application potential of the recycled material and of the fact that longer grinding to obtain finer particles is not necessarily beneficial.

  3. Monitoring a PVC batch process with multivariate statistical process control charts

    NARCIS (Netherlands)

    Tates, A. A.; Louwerse, D. J.; Smilde, A. K.; Koot, G. L. M.; Berndt, H.

    1999-01-01

    Multivariate statistical process control charts (MSPC charts) are developed for the industrial batch production process of poly(vinyl chloride) (PVC). With these MSPC charts different types of abnormal batch behavior were detected on-line. With batch contribution plots, the probable causes of these

  4. Effect of complexing salt on conductivity of PVC/PEO polymer blend ...

    Indian Academy of Sciences (India)

    Administrator

    composite polymer, a blend-based polymer electrolyte, composed of two conductive ... LiClO4 electrolytes with various methacrylic and acrylic polymers used as additives .... Z real vs Z imaginary plot for PVC : PEO : LiBF4 at room temperature.

  5. Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method

    International Nuclear Information System (INIS)

    Burat, Firat; Gueney, Ali; Olgac Kangal, M.

    2009-01-01

    More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35 g/cm 3 and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

  6. Experimental and numerical analysis of water hammer in a large-scale PVC pipeline apparatus

    NARCIS (Netherlands)

    Bergant, A.; Hou, Q.; Keramat, A.; Tijsseling, A.S.; Gajic, A.; Benisek, M.; Nedeljkovic, M.

    2011-01-01

    This paper investigates the effects of the pipe-wall viscoelasticity on water-hammer pressures. A large-scale pipeline apparatus made of polyvinyl chloride (PVC) at Deltares, Delft, The Netherlands, has been used to carry out waterhammer experiments. Tests have been conducted in a

  7. PVC gel soft actuator-based wearable assist wear for hip joint support during walking

    Science.gov (United States)

    Li, Yi; Hashimoto, Minoru

    2017-12-01

    Plasticized polyvinyl chloride (PVC) gel and mesh electrode-based soft actuators have considerable potential to provide new types of artificial muscle, exhibiting similar responsiveness to biological muscle in air, >10% deformation, >90 kPa output stress, variable stiffness, long cycle life (>5 million cycles), and low power consumption. We have designed and fabricated a prototype of walking assist wear using the PVC gel actuator in previous study. The system has several advantages compared with traditional motor-based exoskeletons, including lower weight and power consumption, and no requirement for rigid external structures that constrain the wearer’s joints. In this study, we designed and established a control and power system to making the whole system portable and wearable outdoors. And we designed two control strategies based on the characteristics of the assist wear and the biological kinematics. In a preliminary experimental evaluation, a hemiparetic stroke patient performed a 10 m to-and-fro straight line walking task with and without assist wear on the affected side. We found that the assist wear enabled natural movement, increasing step length and decreasing muscular activity during straight line walking. We demonstrated that the assistance effect could be adjusted by controlling the on-off time of the PVC gel soft actuators. The results show the effectiveness of the proposed system and suggest the feasibility of PVC gel soft actuators for developing practical soft wearable assistive devices, informing the development of future wearable robots and the other soft actuator technologies for human movement assistance and rehabilitation.

  8. Stabilizing effect of epoxidized sunflower oil as a secondary stabilizer for Ca/Hg stabilized PVC

    Directory of Open Access Journals (Sweden)

    2008-01-01

    Full Text Available Unsaturated triglyceride oil sunflower was epoxidized and characterized by chemical and spectroscopic methods. Epoxidized sunflower oil (ESO was used as an organic thermal co-stabilizer for rigid poly(vinyl chloride (PVC in the presence of tricalcium dicitrate (Ca3(C6H5O72 and mercury (II acetate (Hg(CH3COO2. The thermo-oxidative degradation of PVC was studied in the presence of these ternary stabilizer systems at 170, 180, 190 and 200°C in N2 atmosphere. The effects of metal carboxylate combination Ca/Hg in the absence and in the presence of epoxidized sunflower oil on static heat treatment of PVC have been studied. The formation of polyene sequences was investigated by UV-visible and FT-IR spectroscopy and by comparing viscosity data obtained in the presence and in the absence of the additives. It was found that the additives retard the rate of degradation and reduce the extent of polymer chain scission associated with the thermal degradation of poly(vinyl chloride. Synergistic effects were found when stabilizer was blended in 50:50 weight ratios with either. It was found that ESO exerted a stabilizing effect on the degradation of PVC. The activation energy for degraded PVC in absence of stabilizers was 38.6 kJ•mol–1 and in the presence of Ca/Hg and Ca/Hg/ESO were 53.3 and 64.7 kJ•mol–1 respectively. In order of compare the efficiency of the epoxidized sunflower oil with these metal soap stabilizers, thermal stabilities were evaluated on the basis of evolved hydrogen chloride determined by conductometry technique and degree of discoloration are discussed.

  9. Platelet storage in Fresenius/NPBI polyolefin and BTHC-PVC bags: a direct comparison.

    Science.gov (United States)

    Hornsey, V S; McColl, K; Drummond, O; Macgregor, I R; Prowse, C V

    2008-08-01

    New platelet storage systems, such as changes in the plastic of the storage bags, require validation. In this study, pooled buffy coat platelets stored in Fresenius/NPBI polyolefin bags were compared with those stored in Fresenius/NPBI butyryl-trihexyl citrate (BTHC) plasticized polyvinyl chloride (PVC). The CompoSelect thrombocyte polishing filter system (1000 mL polyolefin bag) and the CompoStop F730 system (1300 mL BTHC-PVC bag) were used to prepare paired, plasma-suspended, buffy coat platelet concentrates. Samples were taken up to day 7 for in vitro analysis. In a separate experiment, 12 units were prepared using the CompoStop F730 system and samples taken after leucofiltration for FXIIa assay. By day 7, platelet concentrates stored in BTHC-PVC demonstrated significantly higher pH levels (7.32 +/- 0.05 vs. 7.26 +/- 0.05) and a greater degree of cell lysis as shown by increased lactate dehydrogenase levels (497 +/- 107 vs. 392 +/- 81 U L(-1)). The supernatants contained higher concentrations of soluble P-selectin and the chemokine 'regulated on activation, normal T-cell expressed and presumably secreted', which are released from the alpha-granules during activation. The ATP concentrations were significantly lower in BTHC-PVC. Platelet counts, mean platelet volume and hypotonic shock response were similar for both bags. FXIIa antigen concentrations were 0.6 +/- 0.2 ng mL(-1) indicating that activation of the contact factor pathway had not occurred. Although the CompoStop F730 leucoreduction filter did not activate the contact system, platelets stored in 100% plasma in BTHC-PVC bags demonstrated different in vitro characteristics from those stored in polyolefin. Further work is required to demonstrate whether these differences will affect in vivo recovery and survival.

  10. Influence of Filler Pore Structure and Polymer on the Performance of MOF-based Mixed Matrix Membranes for CO2 Capture.

    Science.gov (United States)

    Sabetghadam, Anahid; Liu, Xinlei; Benzaqui, Marvin; Gkaniatsou, Effrosyni; Orsi, Angelica; Lozinska, Magdalena M; Sicard, Clemence; Johnson, Timothy; Steunou, Nathalie; Wright, Paul A; Serre, Christian; Gascon, Jorge; Kapteijn, Freek

    2018-03-24

    In order to gain insight into the influence of metal-organic framework (MOF) filler and polymer on membrane performance, eight different composites are studied by combining four MOFs and two polymers. MOF materials (NH2-MIL-53(Al), MIL-69(Al), MIL-96(Al) and ZIF-94) with various chemical functionalities, topologies, and dimensionalities of porosity were employed as fillers, while two typical polymers with different permeability-selectivity properties (6FDA-DAM and Pebax) were deliberately selected as matrices. The best performing MOF-polymer composites were prepared by loading 25 wt.% of MIL-96(Al) as filler which improved the permeability and selectivity of 6FDA-DAM up to 32% and 10%, while for Pebax this enhancement was 25% and 18%, respectively. The observed differences in membrane performance in the separation of CO2 from N2 are explained on the basis of gas solubility, diffusivity properties and compatibility between the filler and polymer phases. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Helicobacter pylori-elicited induction in gastric mucosal matrix metalloproteinase-9 (MMP-9) release involves ERK-dependent cPLA2 activation and its recruitment to the membrane-localized Rac1/p38 complex.

    Science.gov (United States)

    Slomiany, B L; Slomiany, A

    2016-06-01

    Matrix metalloproteinases (MMPs) are a family of endopeptidases implicated in a wide rage of degenerative and inflammatory diseases, including Helicobacter pylori-associated gastritis, and gastric and duodenal ulcer. As gastric mucosal inflammatory responses to H. pylori are characterized by the rise in MMP-9 production, as well as the induction in mitogen-activated protein kinase (MAPK) and Rac1 activation, we investigated the role of Rac1/MAPK in the processes associated with the release of MMP-9. We show that H. pylori LPS-elicited induction in gastric mucosal MMP-9 release is associated with MAPK, ERK and p38 activation, and occurs with the involvement of Rac1 and cytosolic phospholipase A2 (cPLA2). Further, we demonstrate that the LPS-induced MMP-9 release requires ERK-mediated phosphorylation of cPLA2 on Ser(505) that is essential for its membrane localization with Rac1, and that this process necessitates p38 participation. Moreover, we reveal that the activation and membrane translocation of p38 to the Rac1-GTP complex plays a pivotal role in cPLA2-dependent enhancement in MMP-9 release. Hence, our findings provide a strong evidence for the role of ERK/cPLA2 and Rac1/p38/cPLA2 cascade in H. pylori LPS-induced up-regulation in gastric mucosal MMP-9 release.

  12. The 1st EMBO workshop on PVC bacteria-Planctomycetes-Verrucomicrobia-Chlamydiae superphylum: exceptions to the bacterial definition?

    Science.gov (United States)

    Devos, Damien P; Jogler, Christian; Fuerst, John A

    2013-10-01

    The PVC superphylum is a phylogenetically supported collection of various related bacterial phyla that comprise unusual characteristics and traits. The 'PVC' abbreviation derives from Planctomycetes, Verrucomicrobia and Chlamydiae as members of this superphylum, while additional bacterial phyla are related. There has recently been increasing and exciting interest in the cell biology, physiology and ecology of members of this superphylum, including evolutionary implications of the complex cell organization of some species. It is timely that international researchers in the PVC superphylum field met to discuss these developments. The first meeting entirely dedicated to those bacteria, the EMBO workshop "PVC superphylum: Exceptions to the bacterial definition" was held at the Heidelberg University to catalyze the formation of a vital scientific community supporting PVC-bacterial research. More than 45 investigators from more than 20 countries (PIs, senior scientists and students) attended the meeting and produced a great starting point for future collaborative research. This Special Issue will focus on the EMBO-PVC meeting. This Perspective briefly summarizes the history of PVC-research, focusing on the key findings and provides a brief summary of the meeting with a focus on the major questions that arose during discussion and that might influence the research in the years to come.

  13. Effect of extensional cyclic strain on the mechanical and physico-mechanical properties of PVC-NBR/graphite composites

    Directory of Open Access Journals (Sweden)

    2008-12-01

    Full Text Available The variation of electrical resistivity as will as the mechanical properties of PVC (polyvinylchloride-NBR (acrylonitrile butadiene rubber based conductive composites filled with different concentrations of graphite were studied. These samples were studied as function of the constant deformation fatigue test. When the specimen was subjected to a large number of rapidly repeating strain cycles, and different strain amplitudes, the conductivity, σ(T, shows an initial rapid fall followed by dynamic equilibrium. Increasing the number of cycles and strain amplitudes, the conductivity remains almost constant over the temperature range 30–140°C. The equilibrium state between destruction and reconstruction of graphite particles has been detected for all strains of certain values of strain cycles (1000, 2000, 3000, and 4000 cycles for 30% strain amplitude. A preliminary study was done to optimize the possibility to use Conductive Polymer Composites (CPC as a strain sensor and to evaluate its performance by an intrinsic physico-mechanical modification measurement. The electromechanical characterization was performed to demonstrate the adaptability and the correct functioning of the sensor as a strain gauge on the fabric. The coefficient of strain sensitivity (K was measured for 50 phr graphite/PVCNBR vulcanized at 3000 number of strain cycles and 30% strain amplitude. There was a broad maximum of K, with a peak value of 82, which was much higher, compared to conventional wire resistors. A slight hysteresis was observed at unloading due to plasticity of the matrix. A good correlation exists between mechanical and electrical response to the strain sensitivity. Mechanical reinforcement was in accordance with the Quemada equation [1] and Guth model [2] attested to good particle-matrix adhesion. It was found that the viscous component of deformation gradually disappeared and the hardening occurred with increasing strain cycles. The modulus, fracture

  14. Preparation of robust braid-reinforced poly(vinyl chloride) ultrafiltration hollow fiber membrane with antifouling surface and application to filtration of activated sludge solution.

    Science.gov (United States)

    Zhou, Zhuang; Rajabzadeh, Saeid; Fang, Lifeng; Miyoshi, Taro; Kakihana, Yuriko; Matsuyama, Hideto

    2017-08-01

    Braid-reinforced hollow fiber membranes with high mechanical properties and considerable antifouling surface were prepared by blending poly(vinyl chloride) (PVC) with poly(vinyl chloride-co-poly(ethylene glycol) methyl ether methacrylate) (poly(VC-co-PEGMA)) copolymer via non-solvent induced phase separation (NIPS). The tensile strength of the braid-reinforced PVC hollow fiber membranes were significantly larger than those of previously reported various types of PVC hollow fiber membranes. The high interfacial bonding strength indicated the good compatibility between the coating materials and the surface of polyethylene terephthalate (PET)-braid. Owing to the surface segregation phenomena, the membrane surface PEGMA coverage increased upon increasing the poly(VC-co-PEGMA)/PVC blending ratio, resulting in higher hydrophilicities and bovine serum albumin (BSA) repulsion. To compare the fouling properties, membranes with similar PWPs were prepared by adjusting the dope solution composition to eliminate the effect of hydrodynamic conditions on the membrane fouling performance. The blend membranes surface exhibited considerable fouling resistance to the molecular adsorption from both BSA solution and activated sludge solution. In both cases, the flux recovered to almost 80% of the initial flux using only water backflush. Considering their great mechanical properties and antifouling resistance to activated sludge solution, these novel membranes show good potential for application in wastewater treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Study on the gamma radiolysis of poly (vinyl chloride). Application to the study on degradation by irradiation and leaching of industrial PVC

    International Nuclear Information System (INIS)

    Colombani, J.

    2006-01-01

    The works presented in this memory enter in the context of the management of plastic nuclear waste. This study was carried out on pure PVC and industrial PVC (formulated polymer). The radiolysis at high doses (up to 4 MGy) of pure PVC in anaerobic condition involves the formation of polyenyl radicals, polyenic sequences, hydrogen chloride and reactions of crosslinking. In aerobic condition, the radiolysis at high doses of pure PVC generates the formation of peroxyl radicals, hydrogen chloride, acid water, carboxylic acids, saturated or conjugated ketones and phenomena of scission. The production of HCl generated by irradiation of industrial PVC was carried out up to 40 MGy. The HCl formed by radiolysis is completely trapped by the calcic loads contained in industrial PVC and by the water produced by these reactions of trapping. A qualitative study on the formation of the products of radiolysis highlighted that the mechanisms of radiolysis of industrial PVC are different from those of pure PVC. This difference is due to the presence of additives belonging to the formulation of industrial PVC. The irradiation of plasticizers such as phthalic esters could induce the formation of radicals being able to react, by reaction of grafting, with the macro-radicals of PVC or with the polyenic sequences formed by radiolysis of PVC macromolecules. The results of leaching experiments tend to confirm this type of mechanism. (author)

  16. Sonochemical synthesis of stibnite nanoparticles and their use as radiolytic stabilizer in polynomial chloride matrix

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Marilia Cordeiro C. de; Lima, Thaysa Araujo de; Aquino, Katia Aparecida da Silva; Araujo, Elmo S., E-mail: aquino@ufpe.b [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2011-07-01

    Stibnite (Sb{sub 2}S{sub 3}) was synthesized by sonochemical method. Amorphous powder of Sb{sub 2}S{sub 3} was obtained and exhibit nanospheres structure with an average size in the range of 300-500 nm. Commercial Polyvinyl Chloride (PVC) containing Sb{sub 2}S{sub 3} nanoparticles (PVC/Sb) at concentrations of 0.10; 0.30 and 0.50 wt% were investigated. The samples were irradiated with gamma radiation ({sup 60}Co) at room temperature and air atmosphere. The viscosity-average molar mass (M{sub v}) was measured for PVC systems without nanoparticles and with nanoparticles. Decreases in molar mass observed when the systems were gamma irradiated reflect the random scission effects that take place in the main chain. Degradation index (DI) value was also obtained by viscosity analysis. DI results showed that the addition of Sb{sub 2}S{sub 3} nanoparticles at 0.3 wt% into PVC matrix irradiated at dose of 25 kGy decreased the number of main chain scissions and was calculated a protection index of 66,5% in PVC matrix. Results about the free radical scavenger action of the Sb{sub 2}S{sub 3} were obtained by use of 2,2-diphenyl-1-(2,4,6-trinitrophenyl)-hydrazyl radical (DPPH) and are discussed in this study. Changes in the infrared spectra of PVC systems indicated that polymer molecules interact with Sb{sub 2}S{sub 3} nanoparticles. (author)

  17. Production of PVC/Abs/Nbr blend and the study of its physical and mechanical properties, thermal behaviour and its morphology

    International Nuclear Information System (INIS)

    Mehrabzadeh, M.; Honarkar, H.

    2001-01-01

    In this research a product of triplet blend of polyvinyl chloride, acrylonitrile-butadiene-styrene, acrylonitrile butadiene rubber (PVC/Abs/Nbr) is obtained. The physical, mechanical and thermal behaviour as well as morphology of the blend were studied. Results show that optimum properties in ratio PVC/Abs: 60/40 is obtained. For substituting the Nbr by a portion of Dop to modify the migration to surface, a triplet blend of PVC/Abs/Nbr was made. Experiments with constant amount of Nbr and variable Dop and vice versa were carried out. For preparation of triplet blend from PVC/Abs, a ratio of 60/40 was used. The best results were obtained for a blend with Nbr (10%) and PVC powder, 20% Nbr and PVC granules containing 34% Dop and the thermo formability of PVC/Abs/Nbr blend was examined as well

  18. Miniaturized membrane sensors for potentiometric determination of metoprolol tartrate and hydrochlorothiazide.

    Science.gov (United States)

    Ramadan, Nesrin K; Mohamed, Heba M; Mostafa, Azza A

    2012-06-01

    Four microsized graphite and platinum wire poly(vinyl chloride) matrix membrane electrodes responsive to some drugs affecting cardiovascular system, Metoprolol tartrate (MT) and Hydrochlorothiazide (HZ) were developed, described and characterized. These sensors were constructed by using (2-Hydroxypropyl)-β-cyclodextrin (2HP β-CD) as an ionophore which has a significant influence on increasing both membrane sensitivity and selectivity. The four sensors were fabricated in a polymeric matrix of carboxylated polyvinyl chloride (PVC-COOH) and dioctylphthalate (DOP) as a plasticizer, based on the interaction between the drugs and the dissociated COOH groups in the PVC-COOH. Fast and stable Nernstian responses of 1.0 × 10-6-1.0 × 10-2 M for MT (sensors 1 and 2) and of 1.0 × 10-7-1.0 × 10-3 M for HZ (sensors 3 and 4) over pH range 3.0-9.0 and 3.0-7.0 for the MT and HZ sensors respectively were obtained. Nernstian slopes of 56.2, 54.6, 19.0 and 20.8 mV/decade for electrodes 1-4 respectively were observed. The proposed method displayed useful analytical characteristics for the determination of MT and HZ in their pure powder forms with average recoveries of 99.11 ± 0.357, 99.21 ± 0.389, 100.08 ± 0.459 and 100.28 ± 0.438% for sensors 1-4 respectively. The lower limit of detection (LOD) were 5.5 × 10-6, 4.5 × 10-6, 4.8 × 10-8 and 5.0 × 10-8 M for sensors 1-4 respectively indicated high sensitivity. The four sensors displayed a good stability over a period of 6 weeks. The selectivity coefficients of the developed sensors indicated excellent selectivity. Results obtained by the four electrodes revealed the performance characteristics of these electrodes which evaluated according to IUPAC recommendations. The method was successively applied for the determination of MT and HZ in presence of each other, in presence of Salamide (SA), the main degradation product of HZ, in their pharmaceutical formulations and in human plasma samples. Statistical comparison between the

  19. Evaluation of the influence of water and oil derivatives absorption on PVC pipes; Avaliacao da influencia da absorcao de agua e de derivados de petroleo em tubulacoes de PVC

    Energy Technology Data Exchange (ETDEWEB)

    Carpio, D.C.F. del; D' Almeida, J.R.M., E-mail: dalmeida@puc-rio.b [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    PVC is the only polymer of large consume that is not totally obtained from petroleum, since it contains 57% of chlorine. As chlorine containing materials are resistant to bacteria rich environments, such as buried pipes, PVC is being used for fluid transportation, principally water, but it can also be considered as an alternative material for the transportation of other fluids. This work analyzes the aging behavior of PVC exposed to water, ethanol and diesel oil, using TGA, DSC, FT-IR and DR-X techniques. The results showed that the chemical structure of PVC is not affected by exposure to water and ethanol. For these fluids a dipolar interaction could be occurring, increasing at the beginning of the absorption process, the polymer thermal stability. The diesel oil caused plasticization, with reduction of the Tg since the beginning of the aging process. (author)

  20. Degradação biológica do PVC em aterro sanitário e avaliação microbiológica Biological degradation of PVC in landfill and microbiological evaluation

    Directory of Open Access Journals (Sweden)

    Ana M. C. Grisa

    2011-01-01

    Full Text Available O poli(cloreto de vinila (PVC é um dos polímeros utilizado no campo das embalagens e no setor calçadista, e, em função da sua aplicação diversificada, apresenta elevados percentuais em aterros domésticos e industriais. É um polímero amorfo podendo apresentar diferentes teores de plastificante e outros aditivos responsáveis pela sua estabilização, os quais podem influenciar no tempo de vida útil e nas propriedades do produto final. Este trabalho apresenta o estudo da degradação química e biológica de filmes de poli(cloreto de vinila flexível (PVC-f, no aterro sanitário São Giácomo, na cidade de Caxias do Sul/RS, antes e após 330 dias de disposição. As amostras de PVC-f antes e após a disposição no aterro sanitário foram avaliadas por análise térmica (TGA, estrutural (FT-IR e morfológica (MEV e MO. Observou-se que as amostras de PVC-f dispostas no aterro sanitário (PVC-fa, apresentam um único evento de perda de massa, em relação ao PVC-f não degradado ou virgem (PVC-fv, além de um maior % de perda de massa e de mudanças estruturais. Nas amostras de PVC-fa foram observadas modificações morfológicas importantes para descrever os fenômenos de degradação como erosão da superfície, bioerosão, que propiciaram a ação das leveduras, bactérias e fungos presentes no meio no polímero aterrado.The poly (vinyl chloride (PVC is one of the polymers used in the field of packing materials and footwear sector, and due its diversified applications, it has presented in a high percentage of domestic and industrial landfills It is an amorphous polymer and may present different levels of plasticizer and other additives responsible for its stabilization, which can influence the lifetime and the properties of the final product. This work presents the study of the chemical and biological degradation of poly (vinyl chloride flexible (PVC-f films, at São Giácomo landfill, in Caxias do Sul city after 330 days of

  1. Matrix theory

    CERN Document Server

    Franklin, Joel N

    2003-01-01

    Mathematically rigorous introduction covers vector and matrix norms, the condition-number of a matrix, positive and irreducible matrices, much more. Only elementary algebra and calculus required. Includes problem-solving exercises. 1968 edition.

  2. Validated RP-HPLC/DAD Method for the Quantification of Insect Repellent Ethyl 2-Aminobenzoate in Membrane-Moderated Matrix Type Monolithic Polymeric Device.

    Science.gov (United States)

    Islam, Johirul; Zaman, Kamaruz; Chakrabarti, Srijita; Sharma Bora, Nilutpal; Mandal, Santa; Pratim Pathak, Manash; Srinivas Raju, Pakalapati; Chattopadhyay, Pronobesh

    2017-07-01

    A simple, accurate and sensitive reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been developed for the estimation of ethyl 2-aminobenzoate (EAB) in a matrix type monolithic polymeric device and validated as per the International Conference on Harmonization guidelines. The analysis was performed isocratically on a ZORBAX Eclipse plus C18 analytical column (250 × 4.4 mm, 5 μm) and a diode array detector (DAD) using acetonitrile and water (75:25 v/v) as the mobile phase by keeping the flow-rate constant at 1.0 mL/min. Determination of EAB was not interfered in the presence of excipients. Inter- and intra-day relative standard deviations were not higher than 2%. Mean recovery was between 98.7 and 101.3%. Calibration curve was linear in the concentration range of 0.5-10 µg/mL. Limits of detection and quantification were 0.19 and 0.60 µg/mL, respectively. Thus, the present report put forward a novel method for the estimation of EAB, an emerging insect repellent, by using RP-HPLC technique. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Composite phase change materials prepared by encapsuling paraffin in PVC macrocapsules

    International Nuclear Information System (INIS)

    Chen, Yingbo; Zhang, Shifeng; Zhang, Qi; Chen, Yusheng; Zhang, Yufeng

    2014-01-01

    Highlights: • PVC macrocapsules coated with SiO 2 were synthesized. • Paraffin was encapsuled in the capsules. • The composite PCM has high heat capacity. • The composite PCM has no surpercooling. - Abstract: A novel phase change material capsules with SiO 2 in their surface was prepared by absorbing paraffin into PVC hollow capsules and by the polycondensation reaction of TEOS in different conditions. X-ray photoelectron spectroscopy (XPS) analysis and scanning electronic microscope (SEM) were used to determine chemical composition and microstructure of the composite capsules, respectively. Enthalpy capacity and thermal stability of the composite capsules are systematically characterized by using differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA) and thermocycling tests. The composite has high heat capacity with good stability and absence of supercooling phenomena

  4. Analysis of Polyadipate Ester Content in PVC Plastics by Means of FT-Raman Spectroscopy

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2006-01-01

    Plasticizers are needed in flexible PVC (PolyVinylChloride) products. There is serious concern that commonly used phthalate esters may harm life reproduction systems. To avoid the problems, instead adipate di-esters (AEs) of C8 to C10 alcohols are used as higher prized alternatives; e.g. di-2......-ethylhexyl adipate or DEHA [103-23-1], also known as Adimoll or di-octyl adipate, DOA. A widely used plasticizer in food (cling) films is DEHA, often in combination with polymers, epoxidized soya-bean oil, etcetera. DEHA also occurs in children toys. We have previously shown that the presence of phthalate...... esters in PVC can be rapidly analyzed by Fourier transform (FT-) Raman spectroscopy excited with a 1064 nm laser. Here in this project we report a similar study. The aim was to find out whether FT-Raman spectroscopy can be used to determine the presence of adipate esters (AEs) as plasticizers...

  5. Utilization of Agrowaste Polymers in PVC/NBR Alloys: Tensile, Thermal, and Morphological Properties

    Directory of Open Access Journals (Sweden)

    Ahmad Mousa

    2012-01-01

    Full Text Available Poly(vinyl chloride/nitrile butadiene rubber (PVC/NBR alloys were melt-mixed using a Brabender Plasticorder at 180∘C and 50 rpm rotor speed. Alloys obtained by melt mixing from PVC and NBR were formulated with wood-flour- (WF- based olive residue, a natural byproduct from olive oil extraction industry. WF was progressively increased from 0 to 30 phr. The effects of WF loadings on the tensile properties of the fabricated samples were inspected. The torque rheometry, which is an indirect indication of the melt strength, is reported. The pattern of water uptake for the composites was checked as a function WF loading. The fracture mode and the quality of bonding of the alloy with and without filler are studied using electron scanning microscope (SEM.

  6. A PVC/polypyrrole sensor designed for beef taste detection using electrochemical methods and sensory evaluation.

    Science.gov (United States)

    Zhu, Lingtao; Wang, Xiaodan; Han, Yunxiu; Cai, Yingming; Jin, Jiahui; Wang, Hongmei; Xu, Liping; Wu, Ruijia

    2018-03-01

    An electrochemical sensor for detection of beef taste was designed in this study. This sensor was based on the structure of polyvinyl chloride/polypyrrole (PVC/PPy), which was polymerized onto the surface of a platinum (Pt) electrode to form a Pt-PPy-PVC film. Detecting by electrochemical methods, the sensor was well characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The sensor was applied to detect 10 rib-eye beef samples and the accuracy of the new sensor was validated by sensory evaluation and ion sensor detection. Several cluster analysis methods were used in the study to distinguish the beef samples. According to the obtained results, the designed sensor showed a high degree of association of electrochemical detection and sensory evaluation, which proved a fast and precise sensor for beef taste detection. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Mechanical properties of oil palm empty fruit bunch (OPEFB) fiber reinforced PVC/ENR blend

    International Nuclear Information System (INIS)

    Gunasunderi Raju Nor Azowa Ibrahim; Mohammad Zaki Abd Rahman; Wan Md Zin Wan Yunus; Chantara Thevy Ratnam

    2004-01-01

    The effect of OPEFB fiber on the mechanical properties of the 50/50 PVC/ENR was investigated over a range of fiber loadings (0 to 30%). The OPEFB fiber reinforced PVC/ENR blend was prepared by using Haake Rheomixer at 150 degree C mixing temperature, 20 minutes total mixing time and 50 rpm rotor speed. The changes in tensile strength (Ts), Young's modulus, elongation break (Eb), flexural modulus, hardness and impact strength with the OPEFB fiber loadings were investigated. The results revealed that the flexural modulus, Young's modulus and hardness increased with the fiber loading. However, the impact strength, Ts and Eb found to decrease with the increase in fiber loading. (Author)

  8. Dosimetry of the JS-6500 industrial irradiator for the irradiation of the PVC graduated flasks

    International Nuclear Information System (INIS)

    Castaneda F, A.; Carrasco A, H.; Martinez P, M.E.

    2002-01-01

    The dosimetry of the JS-6500 AECL irradiator was realized, outside of the industrial transportation rails to know the dose distribution, as well as its dose speed. This one with the intention of exposing to gamma radiation; plastified PVC graduated flasks and evaluating their interweavement or degradation or both. This study of dosimetry was carried out by means of a theoretical and experimental evaluation in air atmosphere. The results allow to know the irradiation conditions of the PVC graduated flasks as well as those results prove that has not a significant difference among the obtained result as theoretical as experimentally due to that the obtained result in the theoretical evaluation is 2.62 KGy/h and the result for the case of the experimental evaluation is 2.74 KGy/h. (Author)

  9. SYNTHESIS OF ACETIC ACID FROM ETHANOL BY ELECTROOXIDATION TECHNIQUE USING Ni-Cu-PVC ELECTRODE

    Directory of Open Access Journals (Sweden)

    Riyanto Riyanto

    2017-11-01

    Full Text Available A usage of Ni-Cu-PVC electrode for the oxidation of ethanol by electrochemical technique will be reported in this paper. In this work, the effect of electrodes on the yields of acetic acid was determined. Electrode used was made of the mixtures of Ni powder, Cu powder and of polyvinyl chloride (PVC with various percentages. Electrooxidation of 0.20 M ethanol in 0.16 M KOH  (24 mL were carried out using chrono coulometry (CC at a potential of 1050 mV for 6 hours with continious stirring. Electrooxdation result obtained was analyzed using High Performance Liquid Chromatography (HPLC. The test result shows that the composition of  Ni:Cu:PVC  at 75:20:5 have higher efficiency in the electrooxidation of ethanol to acetic acid.

  10. Preparation of Drug-loaded Chitosan Microspheres and Its Application in Paper-based PVC Wallpaper

    Science.gov (United States)

    Lin, Hui; Chen, Lihui; Yan, Guiyang; Chen, Feng; Huang, Liulian

    2018-03-01

    By screening through test, it was found that the drug-loaded chitosan microspheres with the average particle size of 615 nm may be prepared with NaF as the mold-proof drug, chitosan as the drug carrier and sodium tripolyphosphate as the cross-linking agent; and they can improve the aspergillus niger-proof effect if loaded onto the base paper surface of the paper-based PVC wallpaper. The results show that NaF and chitosan have mold-proof synergistic effects; the mold-proof effect of the wallpaper may be improved by increasing the dose of chitosan; when the mass ratio of NaF, sodium tripolyphosphate and chitosan was 2:7:28, the paper-based PVC wallpaper with good mold-proof property can be prepared.

  11. Effect analysis of material properties of picosecond laser ablation for ABS/PVC

    Science.gov (United States)

    Tsai, Y. H.; Ho, C. Y.; Chiou, Y. J.

    2017-06-01

    This paper analytically investigates the picosecond laser ablation of ABS/PVC. Laser-pulsed ablation is a wellestablished tool for polymer. However the ablation mechanism of laser processing for polymer has not been thoroughly understood yet. This study utilized a thermal transport model to analyze the relationship between the ablation rate and laser fluences. This model considered the energy balance at the decomposition interface and Arrhenius law as the ablation mechanisms. The calculated variation of the ablation rate with the logarithm of the laser fluence agrees with the measured data. It is also validated in this work that the variation of the ablation rate with the logarithm of the laser fluence obeys Beer's law for low laser fluences. The effects of material properties and processing parameters on the ablation depth per pulse are also discussed for picosecond laser processing of ABS/PVC.

  12. Synthesis and characterization of Zn-doped MgAl-layered double hydroxide nanoparticles as PVC heat stabilizer

    International Nuclear Information System (INIS)

    Wang, Gongling; Yang, Mei; Li, Zhiwen; Lin, Kaifeng; Jin, Quan; Xing, Chaojian; Hu, Zhudong; Wang, Dan

    2013-01-01

    Zn-doped MgAl-layered double hydroxides (LDHs) with M 2+ /M 3+ = 2 and different molar ratios of Mg/Zn have been synthesized by modified homogeneous co-precipitation method and characterized by powder X-ray diffraction, Transmission electron microscopy, Fourier transform infrared spectrum and thermogravimetry, and differential thermal analysis techniques. The thermal stabilizing effects of different LDHs on PVC were studied by Congo red test and thermal aging test. All of the nanoparticles show plate-like morphology and the average diameter of particles is around 90 nm. Results show that the introduction of Zn increased the average bond length and area of the layers of LDHs, therefore enhanced the adsorption ability on HCl gas which was generated during degradation of PVC to improve the thermal stability of PVC. LDHs with molar ratio of Mg/Zn = 1.0 shows the best thermal stabilizing effect on PVC

  13. Synthesis and characterization of Zn-doped MgAl-layered double hydroxide nanoparticles as PVC heat stabilizer

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gongling; Yang, Mei [Chinese Academy of Sciences, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering (China); Li, Zhiwen; Lin, Kaifeng [Harbin Institute of Technology, Academy of Fundamental Interdisciplinary Sciences (China); Jin, Quan; Xing, Chaojian; Hu, Zhudong [Chinese Academy of Sciences, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering (China); Wang, Dan, E-mail: danwang@mail.ipe.ac.cn [Harbin Institute of Technology, Academy of Fundamental Interdisciplinary Sciences (China)

    2013-09-15

    Zn-doped MgAl-layered double hydroxides (LDHs) with M{sup 2+}/M{sup 3+} = 2 and different molar ratios of Mg/Zn have been synthesized by modified homogeneous co-precipitation method and characterized by powder X-ray diffraction, Transmission electron microscopy, Fourier transform infrared spectrum and thermogravimetry, and differential thermal analysis techniques. The thermal stabilizing effects of different LDHs on PVC were studied by Congo red test and thermal aging test. All of the nanoparticles show plate-like morphology and the average diameter of particles is around 90 nm. Results show that the introduction of Zn increased the average bond length and area of the layers of LDHs, therefore enhanced the adsorption ability on HCl gas which was generated during degradation of PVC to improve the thermal stability of PVC. LDHs with molar ratio of Mg/Zn = 1.0 shows the best thermal stabilizing effect on PVC.

  14. Production of pre-basic potato seed by polyvinyl chloride PVC: articulate gutters hydroponic system

    Directory of Open Access Journals (Sweden)

    Jonny Everson Scherwinski-Pereira

    2009-10-01

    Full Text Available The development of more efficient and productive systems for pre-basic seed potato production would improve the quality of the propagative material used by the potato growers, directly affecting the crop yields. A two-year experiment was carried out to evaluate the potato pre-basic seed production by two types of hydroponic systems (fibrocement tiles and articulated PVC gutters, two cultivars (`Baronesa` and `Eliza` and two types of propagative material (plants coming from in vitro culture and minitubers. The PVC gutters system was highly efficient. When using minitubers, this system reached multiplication rates up to 74 tubers per plant. Minitubers were more productive than in vitro plants, independent of cultivar and hydroponic system utilized.Um experimento realizado por dois anos consecutivos avaliou a produção de sementes pré-básicas de batata por meio de sistemas de cultivo hidropônico. O trabalho testou a combinação de dois sistemas de cultivo (telha de fibrocimento e calhas de PVC articuladas, duas cultivares (Baronesa e Eliza e dois tipos de material propagativo (plântulas oriundas do cultivo in vitro e minitubérculos. O sistema de calhas de PVC foi altamente eficiente. Quando foi utilizado minitubérculos, este sistema alcançou taxas de multiplicação de até 74 tubérculos por planta. De modo geral, o uso de minitubérculos como material propagativo apresentou os melhores resultados de produtividade quando comparada ao material in vitro, independentemente da cultivar e sistemas hidropônicos utilizados.

  15. Mechanical behavior of styrene grafted PVC films by electron beam irradiation

    International Nuclear Information System (INIS)

    Cardoso, Jessica R.; Moura, Eduardo; Somessari, Elisabeth S.R.; Silveira, Carlos G.; Paes, Helio A.; Souza, Carlos A.; Manzoli, Jose E.; Geraldo, Aurea B.C.

    2011-01-01

    The polyvinyl chloride (PVC) is a technological and low cost polymer, however it presents high sensitivity to high energy irradiation because of the weakness of carbon-chloride bond face to carbon-carbon and carbon-hydrogen bonds. Grafting is a type of co-polymerization process that can allow it an increase of mechanical characteristics. The aim of this work is to evaluate the mechanical properties of styrene grafted PVC by electron beam irradiation using mutual and pre-irradiation methods to verify the mechanical resistance changes of obtained product whether grafting process is applied from non-irradiated or from pre-irradiated substrates. The irradiation procedures were performed in atmosphere air or inert atmosphere and the irradiation conditions comprised doses from 10 kGy to 100 kGy and dose rates of 2.2 kGy/s and 22.4 kGy/s. The styrene grafted samples were analyzed by gravimetry to determinate the grafting yield; the final values have been averaged from a series of three measurements. The Mid-A TR-FTIR was the spectrophotometer technique used for qualitative/semi-quantitative analysis of grafted samples. The Young's module and tensile strength of pre-irradiated and grafted PVC samples at both methods were measured at a Lloyd LXR tensile tester at a cross-head speed of 10.00 mm/min. We observed the decrease of Young's module and tensile strength with the increase of absorbed dose at pre-irradiated PVC samples. These mechanical parameters results are discussed. (author)

  16. Application of electrostatic separation to the recycling of plastic wastes: separation of PVC, PET, and ABS.

    Science.gov (United States)

    Park, Chul-Hyun; Jeon, Ho-Seok; Yu, Hyo-Shin; Han, Oh-Hyung; Park, Jai-Koo

    2008-01-01

    Plastics are widely used in everyday life as a useful material, and thus their consumption is growing at a rate of about 5% per year in Korea. However, the constant generation of plastic wastes and their disposal generates environmental problems along with economic loss. In particular, mixed waste plastics are difficult to recycle because of their inferior characteristics. A laboratory-scale triboelectrostatic separator unit has been designed and assembled for this study. On the basis of the control of electrostatic charge, the separation of three kinds of mixed plastics, polyvinyl chloride (PVC), poly(ethylene terephthalate) (PET), and acrylonitrile-butadiene-styrene (ABS), in a range of similar gravities has been performed through a two-stage separation process. Polypropylene (PP) and high-impact polystyrene (HIPS) were found to be the most effective materials for a tribo-charger in the separation of PVC, PET, and ABS. The charge-to-mass ratio (nC/g) of plastics increased with increasing air velocity in the tribo charger. In the first stage, using the PP cyclone charger, the separation efficiency of particles considerably depended on the air velocity (10 m/s), the relative humidity ( 20 kV), and the splitter position (+2 cm from the center) in the triboelelctrostatic separator unit. At this time, a PVC grade of 99.40% and a recovery of 98.10% have successfully been achieved. In the second stage, using the HIPS cyclone charger, a PET grade of 97.80% and a recovery of 95.12% could be obtained under conditions of 10 m/s, over 25 kV, a central splitter position, and less than 40% relative humidity. In order to obtain 99.9% PVC grade and 99.3% PET grade, their recoveries should be sacrificed by 20.9% and 27%, respectively, with moving the splitter from the center to a (+)6 cm position.

  17. THE STUDY OF TECHNOLOGICAL PROPERTIES OF PLASTISOLS BASED EMULSION PVC FILLED WITH CHALK GIDROFOBIZIROVANNYM

    Directory of Open Access Journals (Sweden)

    V. A. Sedykh

    2014-01-01

    Full Text Available Baby toys are made using the centrifugal molding plastisol based emulsion of polyvinyl chloride plasticized with dioctylphthalate. To reduce cost and decrease biotelemetry the dioctylphthalate on the surface of the product domestic toys than toys produced in China, there was a necessity of introduction of the filler is chalk from different manufacturers. By using a Brookfield vis-cometer PV-D was studied rheology of filled hydrophobized chalk PVC plastisols in storage conditions for up to 72 hours at temperatures of 14-20°C. It was found that the flow plastisols consistent with pseudo-plastic fluids. Given the flow rates of emulsion PVC plastisols filled to 35 % of the mass. hydrophobized chalk. The influence of the content of the plasticizer dioctylphthalate in a narrow interval (37,0 - 41,4 % of the mass. on the viscosity of polymer pastes and the kinetics of its changes during storage. Revealed a linear dependence of the viscosity of the filled hydrophobized chalk plastisols on the speed of rotation of the spindle of the viscometer and during storage. Given the rate of expansion changes the viscosity of the plastisols of the speed of rotation of the spindle of the viscometer, the rate of change in viscosity and calculation of the initial viscosity. Determined the stability of the dispersion hydrophobized chalk in a colloidal solution of PVC in dioctylphthalate during storage. We determined the variation of the content of chalk (ash with top and bottom layers plastisols height 8 cm after 24 hours storage. It is proved that the temperature of the preparation and storage of polymer pastes were determining factors in the regulation of such technological properties of PVC plastisols in the presence hydrophobized chalkas viscosity, stability of the dispersion of chalk and, consequently, the efficiency of distribution plastisols in the form of a centrifugal molding.

  18. Possibility of the use of PVC plastics as a ray dosemeter

    International Nuclear Information System (INIS)

    Amri Ayat; Sutrisno Puspodikoro.

    1978-01-01

    The use of plastics as a radiation dosemeter for measurement of γ-rays is very attractive to be studied. In the work presented here commercial PVC film with the trade-mark ''Takiron'' is used for Co-60 radiation dosimetry. According to the experiments the useful dose range extends over 0.15-1.2 Mrads. Fading of the coloration with time after radiation exposure can be stabilised by heat treatment (60 deg C for 30 minutes). (author)

  19. Mechanical behavior of styrene grafted PVC films by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Jessica R.; Moura, Eduardo; Somessari, Elisabeth S.R.; Silveira, Carlos G.; Paes, Helio A.; Souza, Carlos A.; Manzoli, Jose E.; Geraldo, Aurea B.C., E-mail: ageraldo@ipen.br, E-mail: jmanzoli@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The polyvinyl chloride (PVC) is a technological and low cost polymer, however it presents high sensitivity to high energy irradiation because of the weakness of carbon-chloride bond face to carbon-carbon and carbon-hydrogen bonds. Grafting is a type of co-polymerization process that can allow it an increase of mechanical characteristics. The aim of this work is to evaluate the mechanical properties of styrene grafted PVC by electron beam irradiation using mutual and pre-irradiation methods to verify the mechanical resistance changes of obtained product whether grafting process is applied from non-irradiated or from pre-irradiated substrates. The irradiation procedures were performed in atmosphere air or inert atmosphere and the irradiation conditions comprised doses from 10 kGy to 100 kGy and dose rates of 2.2 kGy/s and 22.4 kGy/s. The styrene grafted samples were analyzed by gravimetry to determinate the grafting yield; the final values have been averaged from a series of three measurements. The Mid-A TR-FTIR was the spectrophotometer technique used for qualitative/semi-quantitative analysis of grafted samples. The Young's module and tensile strength of pre-irradiated and grafted PVC samples at both methods were measured at a Lloyd LXR tensile tester at a cross-head speed of 10.00 mm/min. We observed the decrease of Young's module and tensile strength with the increase of absorbed dose at pre-irradiated PVC samples. These mechanical parameters results are discussed. (author)

  20. Matrix String Theory

    CERN Document Server

    Dijkgraaf, R; Verlinde, Herman L

    1997-01-01

    Via compactification on a circle, the matrix model of M-theory proposed by Banks et al suggests a concrete identification between the large N limit of two-dimensional N=8 supersymmetric Yang-Mills theory and type IIA string theory. In this paper we collect evidence that supports this identification. We explicitly identify the perturbative string states and their interactions, and describe the appearance of D-particle and D-membrane states.

  1. The pvc operon regulates the expression of the Pseudomonas aeruginosa fimbrial chaperone/usher pathway (cup genes.

    Directory of Open Access Journals (Sweden)

    Uzma Qaisar

    Full Text Available The Pseudomonas aeruginosa fimbrial structures encoded by the cup gene clusters (cupB and cupC contribute to its attachment to abiotic surfaces and biofilm formation. The P. aeruginosa pvcABCD gene cluster encodes enzymes that synthesize a novel isonitrile functionalized cumarin, paerucumarin. Paerucumarin has already been characterized chemically, but this is the first report elucidating its role in bacterial biology. We examined the relationship between the pvc operon and the cup gene clusters in the P. aeruginosa strain MPAO1. Mutations within the pvc genes compromised biofilm development and significantly reduced the expression of cupB1-6 and cupC1-3, as well as different genes of the cupB/cupC two-component regulatory systems, roc1/roc2. Adjacent to pvc is the transcriptional regulator ptxR. A ptxR mutation in MPAO1 significantly reduced the expression of the pvc genes, the cupB/cupC genes, and the roc1/roc2 genes. Overexpression of the intact chromosomally-encoded pvc operon by a ptxR plasmid significantly enhanced cupB2, cupC2, rocS1, and rocS2 expression and biofilm development. Exogenously added paerucumarin significantly increased the expression of cupB2, cupC2, rocS1 and rocS2 in the pvcA mutant. Our results suggest that pvc influences P. aeruginosa biofilm development through the cup gene clusters in a pathway that involves paerucumarin, PtxR, and different cup regulators.

  2. Practical problems in radiation sterilization of medical devices made from plasticized PVC

    International Nuclear Information System (INIS)

    Beenen, J.H.

    1990-01-01

    The following three methods for sterilizing medical devices made from plasticised PVC are used in the Netherlands. 1. sterilization by steam, steam-air or superheated water. 2. sterilization by electron beam or gamma irradiation. 3. ethylene oxide sterilization. IV-bags, blood bags and other bag types for similar applications made from plasticized PVC are mostly sterilized by steam-air or super heated water, especially when filled or partly filled containers are considered. More complicated products or products with components that cannot resist steam sterilization of 121 0 C are sterilized by ethylene oxide or irradiation. These last two methods also are favoured for sterilizing empty bags where sticking of the surfaces at the sterilization temperature creates a serious handicap. Moreover, steam sterilization may cause a permanent opacity of some plastics. However, we have to add that due to developments in formulations steam sterilization of empty bags is going to be of an increasing importance. proven carcinogenity of the gas ethylene oxide, difficult deaeration and retention of the gas in plasticized PVC has increased the demand for better radiation resistant plastics as an alternative for steam sterilization. (author)

  3. PVC flooring is related to human uptake of phthalates in infants.

    Science.gov (United States)

    Carlstedt, F; Jönsson, B A G; Bornehag, C-G

    2013-02-01

    Polyvinyl chloride (PVC) flooring material contains phthalates, and it has been shown that such materials are important sources for phthalates in indoor dust. Phthalates are suspected endocrine-disrupting chemicals (EDCs). Consecutive infants between 2 and 6 months old and their mothers were invited. A questionnaire about indoor environmental factors and family lifestyle was used. Urinary metabolites of the phthalates diethyl phthalate (DEP), dibutyl phthalate (DBP), butylbenzyl phthalate (BBzP), and dietylhexyl phthalate (DEHP) were measured in the urine of the children. Of 209 invited children, 110 (52%) participated. Urine samples were obtained from 83 of these. Urine levels of the BBzP metabolite monobenzyl phthalate (MBzP) was significantly higher in infants with PVC flooring in their bedrooms (P flooring material may increase the human uptake of phthalates in infants. Urinary levels of phthalate metabolites during early life are associated with the use of PVC flooring in the bedroom, body area, and the use of infant formula. This study shows that the uptake of phthalates is not only related to oral uptake from, for example, food but also to environmental factors such as building materials. This new information should be considered when designing indoor environment, especially for children. © 2012 John Wiley & Sons A/S.

  4. Thermal stability of formulations of PVC irradiated with γ of 60

    International Nuclear Information System (INIS)

    Martinez P, M.E.; Carrasco A, H.; Castaneda F, A.; Benavides C, R.; Garcia R, S.P.

    2004-01-01

    The industry of cables and wires frequently use cable isolations with base of formulations of PVC, in those that stabilizer has usually been used with the help of heavy metals, as the lead, which is toxic. To solve the problem, from the 2002 one has come studying in combined form in the National Institute of Nuclear Research ININ and the Center of Investigation in Applied Chemistry CIQA, the modifications induced by the radiation in formulations with the help of vinyl poly chloride PVC. In these formulations, prepared with cross linking agent, plastifying industrial grade, stuff and non toxic stabilizers of calcium estearate and zinc industrial grade, it is sought to replace the stabilizer of Pb. For this were irradiated it test tubes of PVC with gamma radiation of cobalt 60 to three different dose in atmospheres of air and argon. Later it was determined their thermal stability at different times of heating and it was measured the Young modulus by means of thermo mechanical analysis. Those results obtained together with other techniques of characterization suggest that the irradiated proposed formulation can substitute the one stabilized with lead. (Author)

  5. Spectroscopic analysis of PMMA/PVC blends containing CoCl2

    Directory of Open Access Journals (Sweden)

    N.S. Alghunaim

    2015-01-01

    Full Text Available Composites of polymethyl methacrylate (PMMA and polyvinyl chloride (PVC polymer blend containing different concentrations (⩽10 wt. of cobalt chloride (CoCl2 were prepared by casting techniques. The changes of the structural, spectroscopic, optical and thermal parameters of the samples are studied using different tools. FT-IR spectroscopy confirmed the complexation between the blends and Co+2-ions. The decrease or increase of IR band intensity with some shifts of other bands suggests an interaction and compatibility between PMMA/PVC blends with CoCl2 take place. The Ultra violet and visible (UV/Vis spectra indicated that the presence of band gap energy depends on increasing of CoCl2 contents. The absorption intensity of the samples doped with CoCl2 becomes faint lower than the pure blend. The values of energy gap for direct and indirect transition decreases with the increase of CoCl2 due to the presence of charge transfer between PMMA/PVC and CoCl2. The thermogravimetric analysis (TGA curves for all the samples have the same behavior and more steps of decomposition were observed. The reduction of mass loss for samples containing CoCl2 compared to the pure blend was observed and it was attributed to crosslink formation between the blend and CoCl2.

  6. Flame treatment for the selective wetting and separation of PVC and PET.

    Science.gov (United States)

    Pascoe, R D; O'Connell, B

    2003-01-01

    Flame treatment has been used for many years to modify the surface of plastics to allow coatings to be added. The effect of the treatment is to produce hydrophilic species on the surface of the plastic making it water-wettable. The production of hydrophilic plastic surfaces is also required in the selective separation of plastics by froth flotation. For the process to be selective one plastic must be rendered hydrophilic while another remains hydrophobic. In this study the potential for separation of PVC and PET has been investigated. Flame treatment was shown to be very effective in producing a hydrophilic surface on both plastics, although the process was not selective under the conditions investigated. Raising the temperature of the plastics above their softening point produced a hydrophobic recovery. As the softening point of PVC was significantly lower than for PET it was possible to produce a significant difference in hydrophobicity, as judged using contact angle measurement. When immersed in water the contact angle of the PVC was found to be strongly dependent on the pH. Good separation efficiency of the two plastics was achieved by froth flotation from pH 4 to 9. One particular advantage of the technique is that no chemical reagents may be required in the flotation stage. The practicalities of designing a flake treatment system however have to be addressed before considering it to be a viable industrial process.

  7. Thermogravimetric-Mass Spectrometric Study of the Pyrolysis Behavior of PVC

    Institute of Scientific and Technical Information of China (English)

    SUN Qing-lei; SHI Xin-gang; LIN Yun-liang; ZHU He; WANG Xiao; CHENG Chuan-ge; LIU Jian-hua

    2007-01-01

    The pyrolysis characteristics of PVC were systematically investigated using a Netzschne TG thermo-balance coupled to a quadrupole mass spectrometer. The pyrolysis conditions were 0.1 MPa of Ar, a heating rate of 10 ℃/min and a final temperature of 1000 ℃. Both the thermogravimetric properties and the simultaneous evolution of gaseous products during pyrolysis were studied. The TG/DTG results showed that as the pyrolysis temperature increases the weight loss and weight loss rate of PVC increases. Near 412 ℃ the weight loss rate attained its peak value. At higher temperatures the rate of loss gradually decreases. The gases evolved during thermogravimetric analysis were analyzed by a mass spectrometer, monitoring the relative intensity of HCl, C6H6, light hydrocarbon and chlorine-containing gases. The evolution curves showed that HCl, C6H6, light hydrocarbon and chlorine-containing gases all peak at about 416 ℃. This is consistent with the fact that the weight loss curves also peak at about 412 ℃. The extensive HCl evolution is consistent with the high chlorine content of PVC. The formation of these gases can be explained by considering these reactions: dehydrochlorination, intramolecular cyclization and the addition of HCl to unsaturated hydrocarbons.

  8. Flame treatment for the selective wetting and separation of PVC and PET

    International Nuclear Information System (INIS)

    Pascoe, R.D.; O'Connell, B.

    2003-01-01

    Flame treatment has been used for many years to modify the surface of plastics to allow coatings to be added. The effect of the treatment is to produce hydrophilic species on the surface of the plastic making it water-wettable. The production of hydrophilic plastic surfaces is also required in the selective separation of plastics by froth flotation. For the process to be selective one plastic must be rendered hydrophilic while another remains hydrophobic. In this study the potential for separation of PVC and PET has been investigated. Flame treatment was shown to be very effective in producing a hydrophilic surface on both plastics, although the process was not selective under the conditions investigated. Raising the temperature of the plastics above their softening point produced a hydrophobic recovery. As the softening point of PVC was significantly lower than for PET it was possible to produce a significant difference in hydrophobicity, as judged using contact angle measurement. When immersed in water the contact angle of the PVC was found to be strongly dependent on the pH. Good separation efficiency of the two plastics was achieved by froth flotation from pH 4 to 9. One particular advantage of the technique is that no chemical reagents may be required in the flotation stage. The practicalities of designing a flake treatment system however have to be addressed before considering it to be a viable industrial process

  9. Poly(vinyl chloride) membrane alkali metal ion-selective electrodes based on crystalline synthetic zeolite of the Faujasite type

    International Nuclear Information System (INIS)

    Aghai, H.; Giahi, M.; Arvand Barmehi, M.

    2002-01-01

    Potentiometric electrodes based on the incorporation of zeolite particle in to poly (vinyl chloride) (pvc) membranes are described. The electrodes characteristics are evaluated regarding the response towards alkali ions. Pvc membranes plasticised with dibutyl phthalate and without lipophilic additives (co-exchanger) were used throughout this study. The electrode exhibits a Nernst ion response over the alkali metal cations concentration a range of 1.0x10 - 4 - 1.0 x 10 1 M with a slop of 57.0 ± 0.9 mV per decade of concentration a working ph range (3.0- 9.0) and a fast response time (≤15 c). The selective coefficients for cesium ion as test species with respect to alkaline earth, ammonium and some heavy metal ions were determined. Zeolite-PVC electrodes were applied to the determination of ionic surfactant

  10. Electroless plating of PVC plastic through new surface modification method applying a semi-IPN hydrogel film

    International Nuclear Information System (INIS)

    Wang, Ming-Qiu; Yan, Jun; Du, Shi-Guo; Li, Hong-Guang

    2013-01-01

    A novel palladium-free surface activation process for electroless nickel plating was developed. This method applied a semi-Interpenetrating Polymer Network (semi-IPN) hydrogel film to modify the poly(vinyl chloride) (PVC) surface by chemical bonds. The activation process involved the formation of semi-IPN hydrogel film on the PVC surface and the immobilization of catalyst for electroless plating linking to the pretreated substrate via N-Ni chemical bond. The hydrogel layer was used as the chemisorption sites for nickel ions, and the catalyst could initiate the subsequent electroless nickel plating onto the PVC surface. Finally, a Ni–P layer was deposited on the nickel-activated PVC substrate by electroless plating technique. The composition and morphology of nickel-plated PVC foils were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results of SEM and XRD show that a compact and continuous Ni–P layer with amorphous nickel phase is formed on the PVC surface. EDS shows that the content of the nickel and the phosphorus in the deposits is 89.4 wt.% and 10.6 wt.%, respectively.

  11. Electroless plating of PVC plastic through new surface modification method applying a semi-IPN hydrogel film

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ming-Qiu, E-mail: mqwang1514@163.com; Yan, Jun; Du, Shi-Guo; Li, Hong-Guang

    2013-07-15

    A novel palladium-free surface activation process for electroless nickel plating was developed. This method applied a semi-Interpenetrating Polymer Network (semi-IPN) hydrogel film to modify the poly(vinyl chloride) (PVC) surface by chemical bonds. The activation process involved the formation of semi-IPN hydrogel film on the PVC surface and the immobilization of catalyst for electroless plating linking to the pretreated substrate via N-Ni chemical bond. The hydrogel layer was used as the chemisorption sites for nickel ions, and the catalyst could initiate the subsequent electroless nickel plating onto the PVC surface. Finally, a Ni–P layer was deposited on the nickel-activated PVC substrate by electroless plating technique. The composition and morphology of nickel-plated PVC foils were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results of SEM and XRD show that a compact and continuous Ni–P layer with amorphous nickel phase is formed on the PVC surface. EDS shows that the content of the nickel and the phosphorus in the deposits is 89.4 wt.% and 10.6 wt.%, respectively.

  12. Electroless plating of PVC plastic through new surface modification method applying a semi-IPN hydrogel film

    Science.gov (United States)

    Wang, Ming-Qiu; Yan, Jun; Du, Shi-Guo; Li, Hong-Guang

    2013-07-01

    A novel palladium-free surface activation process for electroless nickel plating was developed. This method applied a semi-Interpenetrating Polymer Network (semi-IPN) hydrogel film to modify the poly(vinyl chloride) (PVC) surface by chemical bonds. The activation process involved the formation of semi-IPN hydrogel film on the PVC surface and the immobilization of catalyst for electroless plating linking to the pretreated substrate via Nsbnd Ni chemical bond. The hydrogel layer was used as the chemisorption sites for nickel ions, and the catalyst could initiate the subsequent electroless nickel plating onto the PVC surface. Finally, a Ni-P layer was deposited on the nickel-activated PVC substrate by electroless plating technique. The composition and morphology of nickel-plated PVC foils were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results of SEM and XRD show that a compact and continuous Ni-P layer with amorphous nickel phase is formed on the PVC surface. EDS shows that the content of the nickel and the phosphorus in the deposits is 89.4 wt.% and 10.6 wt.%, respectively.

  13. Affinity of hemoglobin for the cytoplasmic fragment of human erythrocyte membrane band 3. Equilibrium measurements at physiological pH using matrix-bound proteins: the effects of ionic strength, deoxygenation and of 2,3-diphosphoglycerate.

    Science.gov (United States)

    Chétrite, G; Cassoly, R

    1985-10-05

    The cytoplasmic fragment of band 3 protein isolated from the human erythrocyte membrane was linked to a CNBr-activated Sepharose matrix in an attempt to measure, in batch experiments, its equilibrium binding constant with oxy- and deoxyhemoglobin at physiological pH and ionic strength values and in the presence or the absence of 2,3-diphosphoglycerate. All the experiments were done at pH 7.2, and equilibrium constants were computed on the basis of one hemoglobin tetramer bound per monomer of fragment. In 10 mM-phosphate buffer, a dissociation constant KD = 2 X 10(-4)M was measured for oxyhemoglobin and was shown to increase to 8 X 10(-4)M in the presence of 50 mM-NaCl. Association could not be demonstrated at higher salt concentrations. Diphosphoglycerate-stripped deoxyhemoglobin was shown to associate more strongly with the cytoplasmic fragment of band 3. In 10 mM-bis-Tris (pH 7.2) and in the presence of 120 mM-NaCl, a dissociation constant KD = 4 X 10(-4)M was measured. Upon addition of increasing amounts of 2,3-diphosphoglycerate, the complex formed between deoxyhemoglobin and the cytoplasmic fragment o