Thermal stability of sulfonated Poly(Ether Ether Ketone) films : on the role of Protodesulfonation

NARCIS (Netherlands)

Koziara, B.T.; Kappert, E.J.; Ogieglo, W.; Nijmeijer, Kitty; Hempenius, M.A.; Benes, N.E.

Thin film and bulk, sulfonated poly(ether ether ketone) (SPEEK) have been subjected to a thermal treatment at 160–250 °C for up to 15 h. Exposing the films to 160 °C already causes partial desulfonation, and heating to temperatures exceeding 200 °C results in increased conjugation in the material,

Poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) membranes

Energy Technology Data Exchange (ETDEWEB)

Hwang, Mi-Lim; Choi, Jisun; Woo, Hyun-Su; Kumar, Vinod; Sohn, Joon-Yong; Shin, Junhwa, E-mail: shinj@kaeri.re.kr

2014-02-15

Highlights: • PEEK-g-PVBSA, a polymer electrolyte membrane was prepared by a radiation grafting technique. • Poly(ether ether ketone) (PEEK), an aromatic hydrocarbon polymer was used as a grafting backbone film. • The water uptake, proton conductivity, and methanol permeability of the membranes were evaluated. • PEEK-g-PVBSA membranes show considerably lower methanol permeability compared to a Nafion membrane. -- Abstract: In this study, an aromatic hydrocarbon based polymer electrolyte membrane, poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) (PEEK-g-PVBSA), has been prepared by the simultaneous irradiation grafting of vinylbenzyl chloride (VBC) monomer onto a PEEK film and subsequent sulfonation. Each chemical conversion was monitored by FT-IR and SEM–EDX instruments. The physicochemical properties including IEC, water uptake, proton conductivity, and methanol permeability of the prepared membranes were also investigated and found that the values of these properties increase with the increase of degree of grafting. It was observed that the IEC values of the prepared PEEK-g-PVBSA membranes with 32%, 58%, and 80% DOG values were 0.50, 1.05, and 1.22 meq/g while the water uptakes were 14%, 20%, and 21%, respectively. The proton conductivities (0.0272–0.0721 S/cm at 70 °C) were found to be somewhat lower than Nafion 212 (0.126 S/cm at 70 °C) at a relative humidity of 90%. However, the prepared membranes showed a considerably lower methanol permeability (0.61–1.92 × 10{sup −7} cm{sup 2}/s) compared to a Nafion 212 membrane (5.37 × 10{sup −7} cm{sup 2}/s)

The Influence of Operation Temperature of the Characteristic of Sulfonated Polyether-Ether Ketone Electrolyte Membrane

International Nuclear Information System (INIS)

Sri Handayani; Eniya Listiani Dewi

2008-01-01

Recently, high temperature Direct Methanol Fuel Cell (DMFC) has been receiving great attention, because provide faster reaction kinetic, the enhance electrode kinetics, reduced size and reduce Pt-based catalyst poisoning by CO. But at high temperature, it will decrease the membrane performance i.e. low proton conductivity affected by humidification and high methanol crossover as happening to Nafion-117 membrane (commercial membrane). To solve this problems, sulfonated polyether-ether ketone and composite (silica additive) as electrolyte membrane at high temperature DMFC was tried to use. In this research, sPEEK with sulfonation degree (SD) 47 % and 68 % and addition silica 3 wt % were used as electrolyte membranes. Proton conductivity and methanol permeability of these membranes were measured at various temperatures (25, 50, 90 and 140 C ). Proton conductivity of membranes were measured by standard bridge impedance spectroscopy (LCR-meter, HIOKI 3522-50) and it was found about 0.01-0.04 S/cm. Methanol permeability of membranes were investigated by diffusion cell and gave the result about 10 - 6 - 10 - 7cm 2 /s. The best sPEEK membrane was sPEEK membrane with SD 68 % and the addition of silica 3 wt%, signed by highest selectivity value (ratio proton conductivity to methanol permeability). Therefore, electrolyte membrane based sulfonated polyether-ether ketone (SD 68 %) with silica could be used at high temperature which give promising as solid electrolyte membrane in application high temperature DMFC. (author)

Surface modification of carbon fibers by a polyether sulfone emulsion sizing for increased interfacial adhesion with polyether sulfone

Science.gov (United States)

Yuan, Haojie; Zhang, Shouchun; Lu, Chunxiang

2014-10-01

Interests on carbon fiber-reinforced thermoplastic composites are growing rapidly, but the challenges with poor interfacial adhesion have slowed their adoption. In this work, a polyether sulfone (PES) emulsion sizing was prepared successfully for increased interfacial adhesion of carbon fiber/PES composites. To obtain a high-quality PES emulsion sizing, the key factor, emulsifier concentration, was studied by dynamic light scattering technique. The results demonstrated that the suitable weight ratio of PES to emulsifier was 8:3, and the resulting PES emulsion sizing had an average particle diameter of 117 nm and Zeta potential of -52.6 mV. After sizing, the surface oxygen-containing functional groups, free energy and wettability of carbon fibers increased significantly, which were advantageous to promote molecular-level contact between carbon fiber and PES. Finally, short beam shear tests were performed to evaluate the interfacial adhesion of carbon fiber/PES composites. The results indicated that PES emulsion sizing played a critical role for the enhanced interfacial adhesion in carbon fiber/PES composites, and a 26% increase of interlaminar shear strength was achieved, because of the improved fiber surface wettability and interfacial compatibility between carbon fiber and PES.

Side-chain sulfonated poly(ether sulfone)s for PEM applications

Energy Technology Data Exchange (ETDEWEB)

Meier-Haack, J.; Butwilowski, W.; Quetschke, A.; Vogel, C. [Leibniz Institute of Polymer Research Dresden, Dresden (Germany)

2010-07-01

Copoly(arylene ether sulfone)s from bis-(4-fluoro phenyl)sulfone (DFDPhS), bis(4-trimethylsiloxy phenyl)sulfone (DHDPhS), and 2,5-diphenylhydroquinone trimethylsilylether (Bis-TMS-DPhHQ) were obtained by nucleophilic displacement polycondensation with high molecular weights (M{sub n} up to 70,000 g/mol; {eta}{sub inh} up to 0.93 dl/g) and narrow molecular weight distributions (2.1 - 2.9). All copolymers showed a single glass-transition temperature (T{sub g}) around 230 C. Upon sulfonation with concentrated sulfuric acid, the T{sub g}s (from samples in the protonated form) were shifted to higher temperatures (+ 35 {+-} 5 C). NMR spectra and the determined ion-exchange capacities (IEC; 1.46 - 2.05 mmol/g), which were close to the theoretical values, indicating that only the pendant phenyl rings of the 2,5- diphenylhydroquinone moieties in the polymer backbone were sulfonated. Membranes prepared from N-methyl- 2-pyrrolidone (NMP) solutions were transparent and soft. The water-uptake at room temperature increased from 30% to 80% with increasing IEC. Samples from random copolymers with an IEC {>=} 1.8 mmol/g were soluble in water at 90 C. While the proton conductivity of the low IEC samples (random copolymer) (1.46 mmol/g) was lower than that of Nafion {sup registered}, the conductivities of the high IEC samples were superior to Nafion {sup registered}. In general membranes from blockcopolymers showed lower water-uptake, higher dimensional stability and higher proton conductivities as compared to samples from random copolymers with similar monomer composition and ion-exchange capacities. (orig.)

Development of Cutaneous Bioadhesive Ureasil-Polyether Hybrid Films

Directory of Open Access Journals (Sweden)

João Augusto Oshiro Junior

2015-01-01

Full Text Available The hydrolysis and condensation reactions involved in synthesis of ureasil-polyether films influence the film formation time and the number of chemical groups able to form hydrogen bonds, responsible for the bioadhesion, with the biological substrate. The objective of this work was to study the influence of the use of an acid catalyst (hydrochloric acid and a basic catalyst (ammonium fluoride in the hydrolysis and condensation reactions on the time formation and bioadhesion of ureasil-polyether films. The toxicity of the films was evaluated. The MTT assay has shown cell viability of human skin keratinocytes higher than 70% of all analyzed materials suggesting low cytotoxicity. The bioadhesion of the films is strongly dependent on the viscosity and hydrophilic/hydrophobic balance of the polyether chains used to synthetize the hybrid molecules. The use of acid catalyst promotes the formation of less viscous films with higher bioadhesion. The hybrids formed by more hydrophilic PEO chains are more bioadherent, since they can interact more efficiently with the water present in the stratum corneum increasing the bioadhesion. Due to their low toxicity and high bioadhesion, the ureasil-PEO films obtained by using HCl as catalyst agent are good candidates for application to the skin as bioadhesive films.

Effect of degree of sulfonation and casting solvent on sulfonated poly(ether ether ketone) membrane for vanadium redox flow battery

Science.gov (United States)

Xi, Jingyu; Li, Zhaohua; Yu, Lihong; Yin, Bibo; Wang, Lei; Liu, Le; Qiu, Xinping; Chen, Liquan

2015-07-01

The properties of sulfonated poly(ether ether ketone) (SPEEK) membranes with various degree of sulfonation (DS) and casting solvent are investigated for vanadium redox flow battery (VRFB). The optimum DS of SPEEK membrane is firstly confirmed by various characterizations such as physicochemical properties, ion selectivity, and VRFB single-cell performance. Subsequently the optimum casting solvent is selected for the optimum DS SPEEK membrane within N,N‧-dimethylformamide (DMF), N,N‧-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), and dimethylsulfoxide (DMSO). The different performance of SPEEK membranes prepared with various casting solvents can be attributed to the different interaction between solvent and -SO3H group of SPEEK. In the VRFB single-cell test, the optimum SPEEK membrane with DS of 67% and casting solvent of DMF (S67-DMF membrane) exhibits higher VRFB efficiencies and better cycle-life performance at 80 mA cm-2. The investigation of various DS and casting solvent will be effective guidance on the selection and modification of SPEEK membrane towards VRFB application.

Dihydrogenimidazole modified silica-sulfonated poly(ether ether ketone) hybrid materials as electrolyte membranes for direct ethanol fuel cells

Energy Technology Data Exchange (ETDEWEB)

Roelofs, Kimball S.; Hirth, Thomas [Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstr. 12, 70569 Stuttgart (Germany); Schiestel, Thomas, E-mail: Thomas.Schiestel@igb.fraunhofer.de [Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstr. 12, 70569 Stuttgart (Germany)

2011-05-25

The present study reports on dihydrogenimidazole modified inorganic-organic mixed matrix membranes for possible application as a proton exchange membrane in direct ethanol fuel cells. The polymeric phase consisted mainly of sulfonated poly(ether ether ketone) (sPEEK) with a sulfonation degree of 55%. The inorganic phase was built up from hydrophilic fumed silica particles interconnected with partially hydrolyzed and condensed tetraethoxysilane with a total inorganic loading of 27.3%. This inorganic phase was further modified with N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole (DHIM), which consists of an hydrolyzable inorganic part and a functional organic group. The influence of the modifier on the mixed matrix system was studied by means of various modifier concentrations in various aqueous-ethanolic systems (water, 2 M and 4 M ethanol). Modifier concentration and ethanol concentration of the ethanol-water mixture exhibited significant but opposite effects on the liquid uptake of the mixed matrix membranes. The proton conductivity as well as the proton diffusion coefficient as a function of modifier content showed a linear decrease. The proton conductivity as a function of temperature showed Arrhenius behavior and the activation energy of the mixed matrix membranes was 43.9 {+-} 2.6 kJ mol{sup -1}. High selectivity of proton diffusion coefficient to ethanol permeability coefficient was obtained with high modifier concentrations. At low modifier concentrations, this selectivity was dominated by ethanol permeation and at high modifier concentrations by proton diffusion. The main electrolyte properties can be optimized by setting the DHIM content in mixed matrix membrane. With this approach, tailor-made membranes can be prepared for possible application in direct ethanol fuel cells.

Dihydrogenimidazole modified silica-sulfonated poly(ether ether ketone) hybrid materials as electrolyte membranes for direct ethanol fuel cells

International Nuclear Information System (INIS)

Roelofs, Kimball S.; Hirth, Thomas; Schiestel, Thomas

2011-01-01

The present study reports on dihydrogenimidazole modified inorganic-organic mixed matrix membranes for possible application as a proton exchange membrane in direct ethanol fuel cells. The polymeric phase consisted mainly of sulfonated poly(ether ether ketone) (sPEEK) with a sulfonation degree of 55%. The inorganic phase was built up from hydrophilic fumed silica particles interconnected with partially hydrolyzed and condensed tetraethoxysilane with a total inorganic loading of 27.3%. This inorganic phase was further modified with N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole (DHIM), which consists of an hydrolyzable inorganic part and a functional organic group. The influence of the modifier on the mixed matrix system was studied by means of various modifier concentrations in various aqueous-ethanolic systems (water, 2 M and 4 M ethanol). Modifier concentration and ethanol concentration of the ethanol-water mixture exhibited significant but opposite effects on the liquid uptake of the mixed matrix membranes. The proton conductivity as well as the proton diffusion coefficient as a function of modifier content showed a linear decrease. The proton conductivity as a function of temperature showed Arrhenius behavior and the activation energy of the mixed matrix membranes was 43.9 ± 2.6 kJ mol -1 . High selectivity of proton diffusion coefficient to ethanol permeability coefficient was obtained with high modifier concentrations. At low modifier concentrations, this selectivity was dominated by ethanol permeation and at high modifier concentrations by proton diffusion. The main electrolyte properties can be optimized by setting the DHIM content in mixed matrix membrane. With this approach, tailor-made membranes can be prepared for possible application in direct ethanol fuel cells.

Proton-conducting membranes based on benzimidazole-containing sulfonated poly(ether ether ketone) compared with their carboxyl acid form

Energy Technology Data Exchange (ETDEWEB)

Li, Hongtao; Wu, Jing; Zhao, Chengji; Zhang, Gang; Zhang, Yang; Shao, Ke; Xu, Dan; Lin, Haidan; Han, Miaomiao; Na, Hui [Alan G MacDiarmid Institute, College of Chemistry, Jilin University, Changchun 130012 (China)

2009-10-15

A series of sulfonated poly(ether ether ketone) containing pendant carboxyl (C-SPEEKs) have been synthesized using a nucleophilic polycondesation reaction. A condensation reaction between 1,2-diaminobenzene and carboxyl resulted in a new series of copolymers containing benzimidazole groups (SPEEK-BIms). The expected structures of the sulfonated copolymers are confirmed by {sup 1}H NMR. The dependence of ion exchange capacity, water uptake, proton conductivity and methanol diffusion coefficient of SPEEK-BIm membranes has been studied and compared with their carboxyl acid form. The results suggest that the introduction of benzimidazole groups may be responsible for many excellent properties of the membranes for fuel cell. It is noticeable that the markedly improved oxidative stability is benefit for the application of membrane. (author)

A novel sulfonated poly(ether ether ketone) and cross-linked membranes for fuel cells

Energy Technology Data Exchange (ETDEWEB)

Li, Hongtao; Zhang, Gang; Wu, Jing; Zhao, Chengji; Zhang, Yang; Shao, Ke; Han, Miaomiao; Lin, Haidan; Zhu, Jing; Na, Hui [Alan G MacDiarmid Institute, College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, Jilin (China)

2010-10-01

A novel poly(ether ether ketone) (PEEK) containing pendant carboxyl groups has been synthesized by a nucleophilic polycondensation reaction. Sulfonated polymers (SPEEKs) with different ion exchange capacity are then obtained by post-sulfonation process. The structures of PEEK and SPEEKs are characterized by both FT-IR and {sup 1}H NMR. The properties of SPEEKs as candidates for proton exchange membranes are studied. The cross-linking reaction is performed at 140 C using poly(vinyl alcohol) (PVA) as the cross-linker. In comparison with the non-cross-linked membranes, some properties of the cross-linked membranes are significantly improved, such as water uptake, methanol resistance, mechanical and oxidative stabilities, while the proton conductivity decreases. The effect of PVA content on proton conductivity, water uptake, swelling ratio, and methanol permeability is also investigated. Among all the membranes, SPEEK-C-8 shows the highest selectivity of 50.5 x 10{sup 4} S s cm{sup -3}, which indicates that it is a suitable candidate for applications in direct methanol fuel cells. (author)

Fluorinated poly(ether sulfone) ionomers with disulfonated naphthyl pendants for proton exchange membrane applications

Science.gov (United States)

Hu, Zhaoxia; Lu, Yao; Zhang, Xulve; Yan, Xiaobo; Li, Na; Chen, Shouwen

2018-06-01

Proton exchange membranes based on fluorinated poly(ether sulfone)s with disulfonated naphthyl pendants (sSPFES) have been successfully prepared by post functionalization through polymeric SNAr reaction. Copolymer structure was confirmed by H-nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy, the physico-chemical properties of the sSPFES membranes were evaluated by thermogravimetric analysis, gel permeation chromatography, electro-chemical impedance spectroscopy, atomic force microscopy, Fenton, water-swelling and fuel cell test. The pendant grafting degree was controlled by varying the feeding amount of the disulfonaphthols, resulting in the ion exchange capacity about 1.28-1.73 mmol/g. The obtained sSPFES membranes were thermal stable, mechanical ductile, and exhibited dimensional change less than 17%, water uptake below 70%, and proton conductivity as high as 0.17-0.28 S/cm at 90°C in water. In a single H2/O2 fuel cell test at 80°C, the sSPFES-B-3.2 membrane (1.61 mmol/g) showed the maximum power output of 593-658 mW/cm2 at 60%-80% relative humidity, indicating their rather promising potential for fuel cell applications.

Electrochemical investigation of sulfonated poly(ether ether ketone)/clay nanocomposite membranes for moderate temperature fuel cell applications

Energy Technology Data Exchange (ETDEWEB)

Hasani-Sadrabadi, Mohammad Mahdi [Polymer Engineering Department, Amirkabir University of Technology, Tehran (Iran); Biomedical Engineering Department, Amirkabir University of Technology, Tehran (Iran); Dashtimoghadam, Erfan; Sarikhani, Kaveh [Polymer Engineering Department, Amirkabir University of Technology, Tehran (Iran); Majedi, Fatemeh S. [Biomedical Engineering Department, Amirkabir University of Technology, Tehran (Iran); Khanbabaei, Ghader [Polymer Science and Technology Division, Research Institute of Petroleum Industry, Tehran (Iran)

2010-05-01

In the present study, polyelectrolyte membranes based on partially sulfonated poly(ether ether ketone) (sPEEK) with various degrees of sulfonation are prepared. The optimum degree of sulfonation is determined according to the transport properties and hydrolytic stability of the membranes. Subsequently, various amounts of the organically modified montmorillonite (MMT) are introduced into the sPEEK matrices via the solution intercalation technique. The proton conductivity and methanol permeability measurements of the fabricated composite membranes reveal a high proton to methanol selectivity, even at elevated temperatures. Membrane based on sPEEK and 1 wt% of MMT, as the optimum nanoclay composition, exhibits a high selectivity and power density at the concentrated methanol feed. Moreover, it is found that the optimum nanocomposite membrane not only provides higher performance compared to the neat sPEEK and Nafion {sup registered} 117 membranes, but also exhibits a high open circuit voltage (OCV) at the elevated methanol concentration. Owing to the high proton conductivity, reduced methanol permeability, high power density, convenient processability and low cost, sPEEK/MMT nanocomposite membranes could be considered as the alternative membranes for moderate temperature direct methanol fuel cell applications. (author)

Friedel-Crafts Crosslinked Highly Sulfonated Polyether Ether Ketone (SPEEK) Membranes for a Vanadium/Air Redox Flow Battery.

Science.gov (United States)

Merle, Géraldine; Ioana, Filipoi Carmen; Demco, Dan Eugen; Saakes, Michel; Hosseiny, Seyed Schwan

2013-12-30

Highly conductive and low vanadium permeable crosslinked sulfonated poly(ether ether ketone) (cSPEEK) membranes were prepared by electrophilic aromatic substitution for a Vanadium/Air Redox Flow Battery (Vanadium/Air-RFB) application. Membranes were synthesized from ethanol solution and crosslinked under different temperatures with 1,4-benzenedimethanol and ZnCl2 via the Friedel-Crafts crosslinking route. The crosslinking mechanism under different temperatures indicated two crosslinking pathways: (a) crosslinking on the sulfonic acid groups; and (b) crosslinking on the backbone. It was observed that membranes crosslinked at a temperature of 150 °C lead to low proton conductive membranes, whereas an increase in crosslinking temperature and time would lead to high proton conductive membranes. High temperature crosslinking also resulted in an increase in anisotropy and water diffusion. Furthermore, the membranes were investigated for a Vanadium/Air Redox Flow Battery application. Membranes crosslinked at 200 °C for 30 min with a molar ratio between 2:1 (mol repeat unit:mol benzenedimethanol) showed a proton conductivity of 27.9 mS/cm and a 100 times lower VO2+ crossover compared to Nafion.

Nanocomposite Based on Functionalized Gold Nanoparticles and Sulfonated Poly(ether ether ketone Membranes: Synthesis and Characterization

Directory of Open Access Journals (Sweden)

Iole Venditti

2017-03-01

Full Text Available Gold nanoparticles, capped by 3-mercapto propane sulfonate (Au-3MPS, were synthesized inside a swollen sulfonated poly(ether ether ketone membrane (sPEEK. The formation of the Au-3MPS nanoparticles in the swollen sPEEK membrane was observed by spectroscopic and microscopic techniques. The nanocomposite containing the gold nanoparticles grown in the sPEEK membrane, showed the plasmon resonance λmax at about 520 nm, which remained stable over a testing period of three months. The size distribution of the nanoparticles was assessed, and the sPEEK membrane roughness, both before and after the synthesis of nanoparticles, was studied by AFM. The XPS measurements confirm Au-3MPS formation in the sPEEK membrane. Moreover, AFM experiments recorded in fluid allowed the production of images of the Au-3MPS@sPEEK composite in water at different pH levels, achieving a better understanding of the membrane behavior in a water environment; the dynamic hydration process of the Au-3MPS@sPEEK membrane was investigated. These preliminary results suggest that the newly developed nanocomposite membranes could be promising materials for fuel cell applications.

Effects of atomic oxygen irradiation on the surface properties of phenolphthalein poly(ether sulfone)

International Nuclear Information System (INIS)

Pei Xianqiang; Li Yan; Wang Qihua; Sun Xiaojun

2009-01-01

To study the effects of low earth orbit environment on the surface properties of polymers, phenolphthalein poly(ether sulfone) (PES-C) blocks were irradiated by atomic oxygen in a ground-based simulation system. The surface properties of the pristine and irradiated blocks were studied by attenuated total-reflection FTIR (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM). It was found that atomic oxygen irradiation induced the destruction of PES-C molecular chains, including the scission and oxidation of PES-C molecular chains, as evidenced by FTIR and XPS results. The scission of PES-C molecular chains decreased the relative concentration of C in the surface, while the oxidation increased the relative concentration of O in the surface. The changes in surface chemical structure and composition also changed the surface morphology of the block, which shifted from smooth structure before irradiation to 'carpet-like' structure after irradiation

Friedel–Crafts Crosslinked Highly Sulfonated Polyether Ether Ketone (SPEEK Membranes for a Vanadium/Air Redox Flow Battery

Directory of Open Access Journals (Sweden)

Géraldine Merle

2013-12-01

Full Text Available Highly conductive and low vanadium permeable crosslinked sulfonated poly(ether ether ketone (cSPEEK membranes were prepared by electrophilic aromatic substitution for a Vanadium/Air Redox Flow Battery (Vanadium/Air-RFB application. Membranes were synthesized from ethanol solution and crosslinked under different temperatures with 1,4-benzenedimethanol and ZnCl2 via the Friedel–Crafts crosslinking route. The crosslinking mechanism under different temperatures indicated two crosslinking pathways: (a crosslinking on the sulfonic acid groups; and (b crosslinking on the backbone. It was observed that membranes crosslinked at a temperature of 150 °C lead to low proton conductive membranes, whereas an increase in crosslinking temperature and time would lead to high proton conductive membranes. High temperature crosslinking also resulted in an increase in anisotropy and water diffusion. Furthermore, the membranes were investigated for a Vanadium/Air Redox Flow Battery application. Membranes crosslinked at 200 °C for 30 min with a molar ratio between 2:1 (mol repeat unit:mol benzenedimethanol showed a proton conductivity of 27.9 mS/cm and a 100 times lower VO2+ crossover compared to Nafion.

Friedel–Crafts Crosslinked Highly Sulfonated Polyether Ether Ketone (SPEEK) Membranes for a Vanadium/Air Redox Flow Battery

Science.gov (United States)

Merle, Géraldine; Ioana, Filipoi Carmen; Demco, Dan Eugen; Saakes, Michel; Hosseiny, Seyed Schwan

2014-01-01

Highly conductive and low vanadium permeable crosslinked sulfonated poly(ether ether ketone) (cSPEEK) membranes were prepared by electrophilic aromatic substitution for a Vanadium/Air Redox Flow Battery (Vanadium/Air-RFB) application. Membranes were synthesized from ethanol solution and crosslinked under different temperatures with 1,4-benzenedimethanol and ZnCl2 via the Friedel–Crafts crosslinking route. The crosslinking mechanism under different temperatures indicated two crosslinking pathways: (a) crosslinking on the sulfonic acid groups; and (b) crosslinking on the backbone. It was observed that membranes crosslinked at a temperature of 150 °C lead to low proton conductive membranes, whereas an increase in crosslinking temperature and time would lead to high proton conductive membranes. High temperature crosslinking also resulted in an increase in anisotropy and water diffusion. Furthermore, the membranes were investigated for a Vanadium/Air Redox Flow Battery application. Membranes crosslinked at 200 °C for 30 min with a molar ratio between 2:1 (mol repeat unit:mol benzenedimethanol) showed a proton conductivity of 27.9 mS/cm and a 100 times lower VO2+ crossover compared to Nafion. PMID:24957118

Sulfonated carbon black-based composite membranes for fuel cell

Indian Academy of Sciences (India)

Composite membranes were then prepared using S–C as fillers and sulfonated poly(ether ether ketone) (SPEEK) as polymer matrix with three different sulfonation degrees (DS = 60, 70 and 82%). Structure and properties of the composite membranes were characterized by FTIR, TGA, scanning electron microscopy, proton ...

Sulfonated Poly(Ether Ether Ketone)/Functionalized Carbon Nanotube Composite Membrane for Vanadium Redox Flow Battery Applications

International Nuclear Information System (INIS)

Jia, Chuankun; Cheng, Yuanhang; Ling, Xiao; Wei, Guanjie; Liu, Jianguo; Yan, Chuanwei

2015-01-01

A novel sulfonated poly(ether ether ketone) (SPEEK) membrane embedded with the short-carboxylic multi-walled carbon nanotube (we name it as SPEEK/SCCT membrane) for vanadium redox flow battery (VRB) has been prepared with low capacity loss, low cost and high energy efficiency. The mechanical strength, vanadium ions permeability and performance of the membrane in the VRB single cell were characterized. Results showed that the SPEEK/SCCT membrane possessed low permeability of vanadium ions, accompanied by higher mechanical strength than the Nafion 212 membrane. The VRB single cell with SPEEK/SCCT membrane showed 7% higher coulombic efficiency (CE), 6% higher energy efficiency (EE) but lower capacity loss in comparison with the one with Nafion 212. The good cell performance, low capacity loss and high vanadium ions barrier properties of the blend membrane is of significant interest for VRB applications

Controlled swollen and drug release from urea-cross-linked polyether/siloxane hybrids

International Nuclear Information System (INIS)

Santilli, Celso V.; Lopes, Leandro; Pulcinelli, Sandra H.; Chiavacci, Leila A.; Oliveira, Anselmo G.

2009-01-01

From a simple synthesis method we produced transparent ureasil cross-linked polyether (poly(ethylene oxide), PEO, or poly (propylene oxide), PPO) networks, whose designed inter cross-linking distance and tunable swell ability was assessed by small angle X-ray scattering on the D11A-SAXS1 beamline of the LNLS, we demonstrated that the controlled drug release from swell able hydrophilic ureasil-PEO materials can be sustained during some days, while from the unswell able ureasil-PPO ones, during some weeks. This outstanding feature conjugated with the bio medically safe formulation of the ureasil cross-linked polyether/siloxane hybrid widen their scope of application to include the domain of soft and implantable drug delivery devices. (author)

High performance anode based on a partially fluorinated sulfonated polyether for direct methanol fuel cells operating at 130 °C

Science.gov (United States)

Mack, Florian; Gogel, Viktor; Jörissen, Ludwig; Kerres, Jochen

2014-06-01

Due to the disadvantages of the Nafion polymer for the application in the direct methanol fuel cell (DMFC) especial at temperatures above 100 °C several polymers of the hydrocarbon type have already been investigated as membranes and ionomers in the DMFC. Among them were nonfluorinated and partially fluorinated arylene main-chain hydrocarbon polymers. In previous work, sulfonated polysulfone (sPSU) has been applied as the proton-conductive binder in the anode of a DMFC, ending up in good and stable performance. In continuation of this work, in the study presented here a polymer was prepared by polycondensation of decafluorobiphenyl and bisphenol AF. The formed polymer was sulfonated after polycondensation by oleum and the obtained partially fluorinated sulfonated polyether (SFS) was used as the binder and proton conductor in a DMFC anode operating at a temperature of 130 °C. The SFS based anode with 5% as ionomer showed comparable performance for the methanol oxidation to Nafion based anodes and significant reduced performance degradation versus Nafion and sPSU based anodes on the Nafion 115 membrane. Membrane electrode assemblies (MEAs) with the SFS based anode showed drastically improved performance compared to MEAs with Nafion based anodes during operation with lower air pressure at the cathode.

Sulfonated Holey Graphene Oxide (SHGO) Filled Sulfonated Poly(ether ether ketone) Membrane: The Role of Holes in the SHGO in Improving Its Performance as Proton Exchange Membrane for Direct Methanol Fuel Cells.

Science.gov (United States)

Jiang, Zhong-Jie; Jiang, Zhongqing; Tian, Xiaoning; Luo, Lijuan; Liu, Meilin

2017-06-14

Sulfonated holey graphene oxides (SHGOs) have been synthesized by the etching of sulfonated graphene oxides with concentrated HNO 3 under the assistance of ultrasonication. These SHGOs could be used as fillers for the sulfonated aromatic poly(ether ether ketone) (SPEEK) membrane. The obtained SHGO-incorporated SPEEK membrane has a uniform and dense structure, exhibiting higher performance as proton exchange membranes (PEMs), for instance, higher proton conductivity, lower activation energy for proton conduction, and comparable methanol permeability, as compared to Nafion 112. The sulfonated graphitic structure of the SHGOs is believed to be one of the crucial factors resulting in the higher performance of the SPEEK/SHGO membrane, since it could increase the local density of the -SO 3 H groups in the membrane and induce a strong interfacial interaction between SHGO and the SPEEK matrix, which improve the proton conductivity and lower the swelling ratio of the membrane, respectively. Additionally, the proton conductivity of the membrane could be further enhanced by the presence of the holes in the graphitic planes of the SHGOs, since it provides an additional channel for transport of the protons. When used, direct methanol fuel cell with the SPEEK/SHGO membrane is found to exhibit much higher performance than that with Nafion 112, suggesting potential use of the SPEEK/SHGO membrane as the PEMs.

A new interpretation of SAXS peaks in sulfonated poly(ether ether ketone) (sPEEK) membranes for fuel cells.

Science.gov (United States)

Mendil-Jakani, H; Zamanillo Lopez, I; Legrand, P M; Mareau, V H; Gonon, L

2014-06-21

The structure of a commercial sulfonated poly(ether ether ketone) (sPEEK) membrane was analyzed by Small-Angle X-Ray Scattering (SAXS) for different water uptakes obtained after immersion in liquid water at various temperatures. For low membrane swelling, the SAXS profile displays only a wide-angle peak in the 0.2-0.3 Å(-1) region. As the membrane swells, two supplementary correlation peaks arise and shift towards small angles, which are the signature of a structural evolution of the membrane, whereas the wide angle peak remains stable. The SAXS spectra of sPEEK membranes can thus display three correlation peaks simultaneously. Therefore we propose a new interpretation of these SAXS spectra which conclude that the two small angle peaks are attributed to the so-called matrix and ionomer peaks and the wide-angle peak is ascribed to the mean separation distance between sulfonic acid groups grafted onto the polymer backbone. This peak attribution implies that the sPEEK nano-phase separation is triggered by an immersion in hot water (ionomer peak apparition). Our new peak attribution was confirmed by studying the impact of temperature, electron density contrast and ionic exchange capacity.

Crosslinked poly(vinyl alcohol)/sulfonated poly(ether ether ketone) blend membranes for fuel cell applications - Surface energy characteristics and proton conductivity

Energy Technology Data Exchange (ETDEWEB)

Kanakasabai, P.; Vijay, P.; Deshpande, Abhijit P.; Varughese, Susy [Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India)

2011-02-01

Ionic polymers, their blends and composites are considered potential candidates for application as electrolytes in fuel cells. While developing new materials for membranes, it is important to understand the interactions of these electrolytic materials with electrodes/catalysts and with reactants/products. Some of these interactions can be understood by estimating the surface energy and wettability of the membrane materials. In this work, polyvinyl alcohol with varying degrees of sulfonation and its blend with sulfonated poly(ether ether ketone) are prepared and studied for their wettability characteristics using goniometry. The surface energy and its components are estimated using different approaches and compared. Properties such as the ion-exchange capacity, the proton conductivity and the water sorption/desorption behaviour are also investigated to understand the relationship with wettability and surface energy and its components. Among the different methods, the van Oss acid-base and the modified Berthelot approaches yield comparable estimates for the total surface energy. (author)

Conductivity and properties of polysiloxane-polyether cluster-LiTFSI networks as hybrid polymer electrolytes

Science.gov (United States)

Boaretto, Nicola; Joost, Christine; Seyfried, Mona; Vezzù, Keti; Di Noto, Vito

2016-09-01

This report describes the synthesis and the properties of a series of polymer electrolytes, composed of a hybrid inorganic-organic matrix doped with LiTFSI. The matrix is based on ring-like oligo-siloxane clusters, bearing pendant, partially cross-linked, polyether chains. The dependency of the thermo-mechanic and of the transport properties on several structural parameters, such as polyether chains' length, cross-linkers' concentration, and salt concentration is studied. Altogether, the materials show good thermo-mechanical and electrochemical stabilities, with conductivities reaching, at best, 8·10-5 S cm-1 at 30 °C. In conclusion, the cell performances of one representative sample are shown. The scope of this report is to analyze the correlations between structure and properties in networked and hybrid polymer electrolytes. This could help the design of optimized polymer electrolytes for application in lithium metal batteries.

Thermal and Dielectric Behavior Studies of Poly(Arylene Ether Sulfones with Sulfonated and Phosphonated Pendants

Directory of Open Access Journals (Sweden)

Shimoga D. Ganesh

2016-01-01

Full Text Available The present paper discusses the aspects of the synthesizing valeric acid based poly(ether sulfones with active carboxylic acid pendants (VALPSU from solution polymerization technique via nucleophilic displacement polycondensation reaction among 4,4′-dichlorodiphenyl sulfone (DCDPS and 4,4′-bis(4-hydroxyphenyl valeric acid (BHPA. The conditions necessary to synthesize and purify the polymer were investigated in some detail. The synthesized poly(ether sulfones comprise sulfone and ether linkages in addition to reactive carboxylic acid functionality; these active carboxylic acid functional groups were exploited to hold the phenyl sulphonic acid and phenyl phosphonic acid pendants. The phenyl sulphonic acid pendants in VALPSU were easily constructed by altering active carboxylic acid moieties by sulfanilic acid using N,N′-dicyclohexylcarbodiimide (DCC mediated mild synthetic route, whereas the latter one was built in two steps. Initially, polyphosphoric acid condensation with VALPSU by 4-bromoaniline and next straightforward palladium catalyzed synthetic route, in both of which acidic pendants are clenched by polymer backbone via amide linkage. Without impairing the primary polymeric backbone modified polymers were prepared by varying the stoichiometric ratios of respective combinations. All the polymers were physicochemically characterized and pressed into tablets; electrical contacts were established to study the dielectric properties. Finally, the influence of the acidic pendants on the dielectric properties was examined.

Highly stable ionic-covalent cross-linked sulfonated poly(ether ether ketone) for direct methanol fuel cells

Science.gov (United States)

Lei, Linfeng; Zhu, Xingye; Xu, Jianfeng; Qian, Huidong; Zou, Zhiqing; Yang, Hui

2017-05-01

A novel ionic cross-linked sulfonated poly(ether ether ketone) containing equal content of sulfonic acid and pendant tertiary amine groups (TA-SPEEK) has been initially synthesized for the application in direct methanol fuel cells (DMFCs). By adjusting the ratio of p-xylene dibromide to tertiary amine groups of TA-SPEEK, a series of ionic-covalent cross-linked membranes (C-SPEEK-x) with tunable degree of cross-linking are prepared. Compared with the pristine membrane, the ionic and ionic-covalent cross-linked proton exchange membranes (PEMs) exhibit reduced methanol permeability and improved mechanical properties, dimensional and oxidative stability. The proton conductivity and methanol selectivity of protonated TA-SPEEK and C-SPEEK-x at 25 °C is up to 0.109 S cm-1 and 3.88 × 105 S s cm-3, respectively, which are higher than that of Nafion 115. The DMFC incorporating C-SPEEK-25 exhibits a maximum power density as high as 35.3 mW cm-2 with 4 M MeOH at 25 °C (31.8 mW cm-2 for Nafion 115). Due to the highly oxidative stability of the membrane, no obvious performance degradation of the DMFC is observed after more than 400 h operation, indicating such cost-effective ionic-covalent cross-linked membranes have substantial potential as alternative PEMs for DMFC applications.

Dielectric Properties of Polyether Sulfone/Bismaleimide Resin Composite Based on Nanolumina Modified by Super-Critical Ethanol

Science.gov (United States)

Chen, Yufei; Li, Zhichao; Teng, Chengjun; Li, Fangliang; Han, Yang

2016-11-01

Nano-alumina was chemically modified with super-critical ethanol enabling a surface active coating. Modified nano-alumina was incorporated in polymer blends based on thermoplastic polyether sulfone and thermosetting bismaleimide resin to produce novel nanocomposites designated as SCE-Al2O3/PES-MBAE. In the SCE-Al2O3/PES-MBAE nano-composites, the matrix was originally formed from 4,4'-diamino diphenyl methane bismaleimide (MBMI) using the diluents of 3,3'-diallyl bisphenol A (BBA) and bisphenol-A diallyl ether (BBE), while polyether sulfone (PES) was used as toughening agent along with super-critically modified nano-alumina (SCE-Al2O3) as filler material. The content of SCE-Al2O3 was varied from 0 wt.% to 6 wt.%. The nano-composites were characterized for their morphological, spectroscopic and dielectric properties. Fourier transform infrared spectroscopy (FT-IR) indicated that ethanol molecules had adhered to the surface of the nano-Al2O3 in super-critical state. A reaction between MBMI and allyl compound occurred and SCE-Al2O3 was doped into the polymer matrix. Volume resistivity of the composite initially increased and then decreased. The modification due to SCE-Al2O3 could overcome the undesirable impact of PES by using a bare minimum level of SCE-Al2O3. The dielectric constant ( ɛ) and dielectric loss (tan δ) as in the case of volume resistivity were initially increased and then decreased with the content of SCE-Al2O3 in the composite. The dielectric constant, dielectric loss and dielectric strength of SCE-Al2O3 (4 wt.%)/PES (5 wt.%)-MBAE nano-composite were 3.53 (100 Hz), 1.52 × 10-3 (100 Hz) and 15.66 kV/mm, respectively, which indicated that the dielectric properties of the composite fulfilled the basic requirements of electrical and insulating material. It was evident from the morphological analysis that the SCE-Al2O3 was evenly dispersed at the nanoscale; for example, the size of SCE-Al2O3 in SCE-Al2O3 (4 wt.%)/PES (5 wt.%)-MBAE measured less than 50 nm.

Morphology Effect on Proton Dynamics in Nafion® 117 and Sulfonated Polyether Ether Ketone

Science.gov (United States)

Leong, Jun Xing; Diño, Wilson Agerico; Ahmad, Azizan; Daud, Wan Ramli Wan; Kasai, Hideaki

2016-09-01

We report results of our experimental and theoretical studies on the dynamics of proton conductivity in Nafion® 117 and self-fabricated sulfonated polyether ether ketone (SPEEK) membranes. Knowing that the presence of water molecules in the diffusion process results in a lower energy barrier, we determined the diffusion barriers and corresponding tunneling probabilities of Nafion® 117 and SPEEK system using a simple theoretical model that excludes the medium (water molecules) in the initial calculations. We then propose an equation that relates the membrane conductivity to the tunneling probability. We recover the effect of the medium by introducing a correction term into the proposed equation, which takes into account the effect of the proton diffusion distance and the hydration level. We have also experimentally verified that the proposed equation correctly explain the difference in conductivity between Nafion® 117 and SPEEK. We found that membranes that are to be operated in low hydration environments (high temperatures) need to be designed with short diffusion distances to enhance and maintain high conductivity.

State of the water in crosslinked sulfonated poly(ether ether ketone). Two-dimensional differential scanning calorimetry correlation mapping

Energy Technology Data Exchange (ETDEWEB)

Al Lafi, Abdul G. [Department of Chemistry, Atomic Energy Commission, Damascus, P.O. Box 6091 (Syrian Arab Republic); Hay, James N., E-mail: cscientific9@aec.org.sy [The School of Metallurgy and Materials, College of Physical Sciences and Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

2015-07-20

Highlights: • 2D-DSC mapping was applied to analyze the heat flow responses of hydrated crosslinked sPEEK. • Two types of loosely bond water were observed. • The first was bond to the sulfonic acid groups and increased with ion exchange capacity. • The second was attributed to the polar groups introduced by ions irradiation and increased with crosslinking degree. • DSC combined with 2D mapping provides a powerful tool for polymer structural determination. - Abstract: This paper reports the first application of two-dimensional differential scanning calorimetry correlation mapping, 2D-DSC-CM to analyze the heat flow responses of sulphonated poly(ether ether ketone), sPEEK, films having different ion exchange capacity and degrees of crosslinks. With the help of high resolution and high sensitivity of 2D-DSC-CM, it was possible to locate two types of loosely bound water within the structure of crosslinked sPEEK. The first was bound to the sulfonic acid groups and dependent on the ion exchange capacity of the sPEEK. The second was bound to other polar groups, either introduced by irradiation with ions and dependent on the crosslinking degree or present in the polymer such as the carbonyl groups or terminal units. The results suggest that the ability of the sulfonic acid groups in the crosslinked sPEEK membranes to adsorb water molecules is increased by crosslinking, probably due to the better close packing efficiency of the crosslinked samples. DSC combined with 2D correlation mapping provides a fast and powerful tool for polymer structural determination.

Quantum dots-hyperbranched polyether hybrid nanospheres towards delivery and real-time detection of nitric oxide

DEFF Research Database (Denmark)

Liu, Shuiping; Gu, Tianxun; Fu, Jiajia

2014-01-01

In this work, novel hybrid nanosphere vehicles were synthesized for nitric oxide (NO) donating and real-time detection. The hybrid nanosphere vehicles consist of cadmium selenide quantum dots (CdSe QDs) as NO fluorescent probes, and the modified hyperbranched polyether (mHP)-based diazeniumdiolates...... as NO donors, respectively. The nanospheres have spherical outline with dimension of ~ 127 nm. The data of systematic characterization demonstrated that the mHP-based hybrid nanosphere vehicles (QDs-mHP-NO) can release and real-time detect NO with the low limit of 25 nM, based on fluorescence quenching...

Influence of Silica/Sulfonated Polyether-Ether Ketone as Polymer Electrolyte Membrane for Hydrogen Fueled Proton Exchange Membrane Fuel Cells

Directory of Open Access Journals (Sweden)

Sri Handayani

2011-12-01

Full Text Available The operation of non-humidified condition of proton exchange membrane fuel cell (PEMFC using composite sPEEK-silica membrane is reported. Sulfonated membrane of PEEK is known as hydrocarbon polyelectrolyte membrane for PEMFC and direct methanol fuel cell (DMFC. The state of the art of fuel cells is based on the perluorosulfonic acid membrane (Nafion. Nafion has been the most used in both PEMFC and DMFC due to good performance although in low humidified condition showed poor current density. Here we reported the effect of silica in hydrocarbon sPEEK membrane that contributes for a better water management system inside the cell, and showed 0.16 W/cm2 of power density which is 78% higher than that of non-silica modified [Keywords: composite membrane, polyether-ether ketone, silica, proton exchange membrane fuel cell].

Fuel cell performance of pendent methylphenyl sulfonated poly(ether ether ketone ketone)s

Science.gov (United States)

Zhang, Hanyu; Stanis, Ronald J.; Song, Yang; Hu, Wei; Cornelius, Chris J.; Shi, Qiang; Liu, Baijun; Guiver, Michael D.

2017-11-01

Meta- and para-linked homopolymers bearing 3-methylphenyl (Me) pendent groups were postsulfonated to create sulfonated poly(ether ether ketone ketone) (SPEEKK) backbone isomers, which are referred to as Me-p-SPEEKK and Me-m-SPEEKK. Their thermal and oxidative stability, mechanical properties, dimensional stability, methanol permeability, and proton conductivity are characterized. Me-p-SPEEKK and Me-m-SPEEKK proton conductivities at 100 °C are 116 and 173 mS cm-1, respectively. Their methanol permeabilities are 3.3-3.9 × 10-7 cm2 s-1, and dimensional swelling at 100 °C is 16.4-17.5%. Me-p-SPEEKK and Me-m-SPEEKK were fabricated into membrane electrode assemblies (MEAs), and electrochemical properties were evaluated within a direct methanol fuel cell (DMFC) and proton-exchange membrane fuel cell (PEMFC). When O2 is used as the oxidant at 80 °C and 100% RH, the maximum power density of Me-m-SPEEKK reaches 657 mW cm-2, which is higher than those of Nafion 115 (552 mW cm-2). DMFC performance is 85 mW cm-2 at 80 °C with 2.0 M methanol using Me-p-SPEEKK due to its low MeOH crossover. In general, these electrochemical results are comparable to Nafion. These ionomer properties, combined with a potentially less expensive and scalable polymer manufacturing process, may broaden their potential for many practical applications.

Effect of cesium salt of tungstophosphoric acid (Cs-TPA) on the properties of sulfonated polyether ether ketone (SPEEK) composite membranes for fuel cell applications

Energy Technology Data Exchange (ETDEWEB)

Dogan, Hacer; Inan, Tuelay Y.; Unveren, Elif [The Scientific and Technological Research Council of Turkey (TUeBiTAK), Marmara Research Center, Chemistry Institute, P.K. 21, 41470 Gebze-Kocaeli (Turkey); Kaya, Metin [DEMIRDOeKUeM A.S. 4 Eyluel Mah, ismet inoenue Cad. No:245 Bozueyuek/Bilecik (Turkey)

2010-08-15

We have prepared composite membranes for fuel cell applications. Cesium salt of tungstophosphoric acid (Cs-TPA) particles was synthesized by aqueous solutions of tungstophosphoric acid and cesium hydroxide and, Cs-TPA particles and sulfonated (polyether ether ketone) (SPEEK) with two sulfonation degrees (DS), 60 and 70%have been used. We examined both the effects of Cs-TPA in SPEEK membranes as functions of sulfonation degrees of SPEEK and the content of Cs-TPA. The performance of the composite membranes was evaluated in terms of water uptake, ion exchange capacity, proton conductivity, chemical stability, hydrolytic stability, thermal stability and methanol permeability. The morphology of the membranes was investigated with SEM micrographs. Increasing sulfonation degree of SPEEK from 60 to 70 caused agglomeration of the Cs-TPA particles. The methanol permeability was reduced to 4.7 x 10{sup -7} cm{sup 2}/s for SPEEK (DS: 60%)/Cs-TPA membrane with 10 wt.% Cs-TPA concentration, and acceptable proton conductivity of 1.3 x 10{sup -1} S/cm was achieved at 80 C under 100% RH. The weight loss at 900 C increased with the addition of inorganic particles, as expected. The hydrolytic stability of the SPEEK/Cs-TPA based composite membranes was improved with the incorporation of the Cs-TPA particles into the matrix. We also noted that SPEEK60/Cs-TPA composite membranes were hydrolytically more stable than SPEEK70/Cs-TPA composite membranes. On the other hand, Methanol, water vapor, and hydrogen permeability values of SPEEK60 composite membranes were found to be lower than that of Nafion {sup registered}. (author)

Silane Cross-Linked Sulfonted Poly(Ether Ketone/Ether Benzimidazoles for Fuel Cell Applications

Directory of Open Access Journals (Sweden)

Zilu Yao

2017-11-01

Full Text Available γ-(2,3-epoxypropoxy propyltrimethoxysilane (KH-560 was incorporated in various proportions into side-chain-type sulfonated poly(ether ketone/ether benzimidazole (SPEKEBI as a crosslinker, to make membranes with high ion exchange capacities and excellent performance for direct methanol fuel cells (DMFCs. Systematical measurements including Fourier transform infrared (FT-IR, scanning electron microscopy-energy-dispersive and X-ray photoelectron spectroscopy (XPS proved the complete disappearance of epoxy groups in KH-560 and the existence of Si in the membranes. The resulting membranes showed increased mechanical strength and thermal stability compared to the unmodified sulfonated poly(ether ketone/ether benzimidazole membrane in appropriate doping amount. Meanwhile, the methanol permeability has decreased, leading to the increase of relative selectivities of SPEKEBI-x-SiO2 membranes. Furthermore, the H2/O2 cell performance of SPEKEBI-2.5-SiO2 membrane showed a much higher peak power density compared with the pure SPEKEBI memrbrane.

Improved antifouling potential of polyether sulfone polymeric membrane containing silver nanoparticles: self-cleaning membranes.

Science.gov (United States)

Rana, Sidra; Nazar, Umair; Ali, Jafar; Ali, Qurat Ul Ain; Ahmad, Nasir M; Sarwar, Fiza; Waseem, Hassan; Jamil, Syed Umair Ullah

2018-06-01

A new strategy to enhance the antifouling potential of polyether sulfone (PES) membrane is presented. Chemically synthesized silver nanoparticles (AgNPs) were used to prepare a mixed-matrix PES membrane by the phase inversion technique. Primarily, AgNPs synthesis was confirmed by surface plasmon resonance at 410-430 nm using UV-Visible spectroscopy. X-ray diffraction analysis revealed that AgNPs were crystalline with a diameter of 21 ± 2 nm. Furthermore, PES membranes were characterized by energy dispersive X-ray spectroscopy to confirm the incorporation of AgNPs in membranes. Hydrophilicity of the membranes was enhanced, whereas roughness, mechanical strength and biofouling were relatively reduced after embedding the AgNPs. Antibacterial potential of AgNPs was evaluated for E. coli in the disc diffusion and colony-forming unit (CFU) count method. All of the membranes were assessed for antifouling activity by filtering a control dilution (10 6  CFU/ml) of E. coli and by counting CFU. Anti-biofouling activity of the membrane was observed with different concentrations of AgNPs. Maximum reduction (66%) was observed in membrane containing 1.5% of AgNPs. The addition of antibiotic ceftriaxone enhanced the antibacterial effect of AgNPs in PES membranes. Our practicable antifouling strategy may be applied to other polymeric membranes which may pave the new way to achieve sustainable and self-cleaning membrane reactors on large scale.

Controlled sulfonation of poly(ether sulfone using phthalic anhydride as catalyst and its membrane performance for fuel cell application

Directory of Open Access Journals (Sweden)

Seikh Jiyaur Rahaman

2016-09-01

Full Text Available Proton exchange membrane (PEM fuel cells are one of the most emerging alternative energy technologies under development. A novel proton exchange membrane sulfonated polyethersulfone (SPES was developed by homogeneous method using phthalic anhydride as catalyst and chlorosulfonic acid as sulfonating agent to control the sulfonation reaction. The method of sulfonation was optimized by varying the reaction time and concentration of the catalyst. The structure of the SPES was studied by 1H-Nuclear Magnetic Resonance, Fourier Transform Infra Red Spectroscopy and X-ray diffraction. The extent of sulfonation was determined by ion exchange capacity studies. The thermal and mechanical stabilities were studied using thermogravimetric analysis (TGA and Dynamic Mechanical Analysis (DMA respectively. DMA results show that the storage modulus increased with increase in degree of sulfonation (DS and water uptake of SPES increased with DS. The proton conductivity of SPES (34% DS measured by impedance spectroscopy was found to be 0.03S/cm at 80%RH and 100°C. Also, current-voltage polarization characteristics of SPES membranes offer a favourable alternative PEM due to the thermal stability and cost effective than perfluorinated ionomers.

Preparation of new proton exchange membranes using sulfonated poly(ether sulfone) modified by octylamine (SPESOS)

International Nuclear Information System (INIS)

Mabrouk, W.; Ogier, L.; Matoussi, F.; Sollogoub, C.; Vidal, S.; Dachraoui, M.; Fauvarque, J.F.

2011-01-01

Highlights: → New, simple and cheap way to synthesize a membrane. → The membranes combine good proton conductivities with good mechanical properties. → The membrane performances in a fuel cell are similar to the Nafion 117. - Abstract: Sulfonated poly(arylene ether sulfone) (SPES) has received considerable attention in membrane preparation for proton exchange membrane fuel cell (PEMFC). But such membranes are brittle and difficult to handle in operation. We investigated new membranes using SPES grafted with various degrees of octylamine. Five new materials made from sulfonated polyethersulfone sulfonamide (SPESOS) were synthetized with different grades of grafting. They were made from SPES, with initially an ionic exchange capacity (IEC) of 2.4 meq g -1 (1.3 H + per monomer unit). Pristine SPES with that IEC is water swelling and becomes soluble at 80 deg. C, its proton conductivity is in the range of 0.1 S cm -1 at room temperature in aqueous H 2 SO 4 1 M, similar to that of Nafion. After grafting with various amounts of octylamine, the material is water insoluble; membranes are less brittle and show sufficient ionic conductivity. Proton transport numbers were measured close to 1.

Optimization of the transport and mechanical properties of polysiloxane/polyether hybrid polymer electrolytes

International Nuclear Information System (INIS)

Boaretto, Nicola; Horn, Theresa; Popall, Michael; Sextl, Gerhard

2017-01-01

In this study, the thermo-mechanical properties of networked, polysiloxane/polyether-based, hybrid polymer electrolytes are optimized with the aim of enabling room-temperature operation in lithium metal-polymer batteries. The structural parameters of the electrolytes (polyether chain length, cross-linking and salt concentration) are varied in order to get the best tradeoff between conductivity and mechanical stability. The optimized material has a conductivity close to 1.5·10 −4 S cm −1 at room temperature and a shear storage modulus of 50 kPa up to 100 °C. The effect of TiO 2 nano-particles is also studied with the results showing an overall ambiguous effect on the materials properties. Finally, one of the materials with the highest conductivity is used as electrolyte in a Li/LiFePO 4 cell. This cell has good rate capability and cyclability due to the high conductivity of the electrolyte. However, the high conductivity is reached at expense of the mechanical stability and the resulting electrolyte proves to be too weak to work as an efficient barrier against lithium dendrite growth.

Improved interfacial adhesion in carbon fiber/polyether sulfone composites through an organic solvent-free polyamic acid sizing

Energy Technology Data Exchange (ETDEWEB)

Yuan, Haojie [National Engineering Laboratory for carbon fiber technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Shouchun, E-mail: zschun@sxicc.ac.cn [National Engineering Laboratory for carbon fiber technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); Lu, Chunxiang, E-mail: chunxl@sxicc.ac.cn [National Engineering Laboratory for carbon fiber technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); He, Shuqing [National Engineering Laboratory for carbon fiber technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); An, Feng [National Engineering Laboratory for carbon fiber technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China)

2013-08-15

An organic solvent-free polyamic acid (PAA) nanoemulsion was obtained by direct ionization of the solid PAA in deionized water, with the average particle size of 261 nm and Zeta potential of −55.1 mV, and used as a carbon fiber sizing to improve the interfacial adhesion between the carbon fiber and polyether sulfone (PES). The surface characteristics of PAA coated carbon fibers were investigated using Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and dynamic contact angle measurement. The results demonstrated that a continuous and uniform PAA sizing layer was formed on the surface of carbon fibers, and the surface energy of carbon fibers increased from 42.91 to 54.55 mN/m after sizing treatment. The single fiber pull-out testing was also performed, which showed the increased interfacial shear strength (IFSS) of carbon fiber/PES composites from 33.6 to 49.7 MPa by 47.9%. The major reasons for the improved interfacial adhesion were the increased van der Waals forces between the PES matrix and sizing layer as well as the chemical bonding between the sizing layer and carbon fiber surface. Furthermore, the PAA sizing also presented a positive effect on the interfacial adhesion of carbon fiber/PES composites under hydrothermal condition.

Anti-fouling behavior of hyperbranched polyglycerol-grafted poly(ether sulfone) hollow fiber membranes for osmotic power generation.

Science.gov (United States)

Li, Xue; Cai, Tao; Chung, Tai-Shung

2014-08-19

To sustain high performance of osmotic power generation by pressure-retarded osmosis (PRO) processes, fouling on PRO membranes must be mitigated. This is especially true for the porous support of PRO membranes because its porous structure is very prone to fouling by feeding river water. For the first time, we have successfully designed antifouling PRO thin-film composite (TFC) membranes by synthesizing a dendritic hydrophilic polymer with well-controlled grafting sites, hyperbranched polyglycerol (HPG), and then grafting it on poly(ether sulfone) (PES) hollow fiber membrane supports. Compared to the pristine PES membranes, polydopamine modified membranes, and conventional poly(ethylene glycol) (PEG)-grafted membranes, the HPG grafted membranes show much superior fouling resistance against bovine serum albumin (BSA) adsorption, E. coli adhesion, and S. aureus attachment. In high-pressure PRO tests, the PES TFC membranes are badly fouled by model protein foulants, causing a water flux decline of 31%. In comparison, the PES TFC membrane grafted by HPG not only has an inherently higher water flux and a higher power density but also exhibits better flux recovery up to 94% after cleaning and hydraulic pressure impulsion. Clearly, by grafting the properly designed dendritic polymers to the membrane support, one may substantially sustain PRO hollow fiber membranes for power generation.

Improved interfacial adhesion in carbon fiber/polyether sulfone composites through an organic solvent-free polyamic acid sizing

International Nuclear Information System (INIS)

Yuan, Haojie; Zhang, Shouchun; Lu, Chunxiang; He, Shuqing; An, Feng

2013-01-01

An organic solvent-free polyamic acid (PAA) nanoemulsion was obtained by direct ionization of the solid PAA in deionized water, with the average particle size of 261 nm and Zeta potential of −55.1 mV, and used as a carbon fiber sizing to improve the interfacial adhesion between the carbon fiber and polyether sulfone (PES). The surface characteristics of PAA coated carbon fibers were investigated using Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and dynamic contact angle measurement. The results demonstrated that a continuous and uniform PAA sizing layer was formed on the surface of carbon fibers, and the surface energy of carbon fibers increased from 42.91 to 54.55 mN/m after sizing treatment. The single fiber pull-out testing was also performed, which showed the increased interfacial shear strength (IFSS) of carbon fiber/PES composites from 33.6 to 49.7 MPa by 47.9%. The major reasons for the improved interfacial adhesion were the increased van der Waals forces between the PES matrix and sizing layer as well as the chemical bonding between the sizing layer and carbon fiber surface. Furthermore, the PAA sizing also presented a positive effect on the interfacial adhesion of carbon fiber/PES composites under hydrothermal condition.

Properties investigation of sulfonated poly(ether ether ketone)/polyacrylonitrile acid-base blend membrane for vanadium redox flow battery application.

Science.gov (United States)

Li, Zhaohua; Dai, Wenjing; Yu, Lihong; Liu, Le; Xi, Jingyu; Qiu, Xinping; Chen, Liquan

2014-11-12

Acid-base blend membrane prepared from sulfonated poly(ether ether ketone) (SPEEK) and polyacrylonitrile (PAN) was detailedly evaluated for vanadium redox flow battery (VRFB) application. SPEEK/PAN blend membrane exhibited dense and homogeneous cross-section morphology as scanning electron microscopy and energy-dispersive X-ray spectroscopy images show. The acid-base interaction of ionic cross-linking and hydrogen bonding between SPEEK and PAN could effectively reduce water uptake, swelling ratio, and vanadium ion permeability, and improve the performance and stability of blend membrane. Because of the good balance of proton conductivity and vanadium ion permeability, blend membrane with 20 wt % PAN (S/PAN-20%) showed higher Coulombic efficiency (96.2% vs 91.1%) and energy efficiency (83.5% vs 78.4%) than Nafion 117 membrane at current density of 80 mA cm(-2) when they were used in VRFB single cell. Besides, S/PAN-20% membrane kept a stable performance during 150 cycles at current density of 80 mA cm(-2) in the cycle life test. Hence the SPEEK/PAN acid-base blend membrane could be used as promising candidate for VRFB application.

Sulfonation degree effect on ion-conducting SPEEK-titanium oxide membranes properties

Energy Technology Data Exchange (ETDEWEB)

Marrero, Jacqueline Costa; Gomes, Ailton de Souza; Dutra Filho, José Carlos, E-mail: jacquecosta@gmail.com [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Instituto de Macromoléculas Professora Eloisa Mano; Hui, Wang Shu [Universidade de São Paulo (USP), São Paulo, SP (Brazil). Departamento de Engenharia Metalúrgica e de Materiais; Oliveira, Vivianna Silva de [Escola Técnica Rezende Rammel (ETRR), Rio de Janeiro, RJ (Brazil)

2017-07-01

Polymeric membranes were developed using a SPEEK (sulfonated poly(ether ether ketone)) polymer matrix, containing titanium oxide (TiO{sub 2}) (incorporated by sol-gel method). SPEEK with different sulfonation degrees (SD): 63% and 50% were used. The influence of sulfonation degree on membrane properties was investigated. The thermal analysis (TGA and DTGA) and X-ray diffraction (XRD) were carried out to characterize the membranes and electrochemical impedance spectroscopy (EIS) was carried out to evaluate the proton conductivity of the membranes. The proton conductivities in water were of 3.25 to 37.08 mS.cm{sup -1}. Experimental data of impedance spectroscopy were analyzed with equivalent circuits using the Zview software, and the results showed that, the best fitted was at 80 °C. (author)

Polymer sulfonation- a versatile route to prepare proton-conducting membrane material for advanced technologies

International Nuclear Information System (INIS)

Zaidi, S.M.J.

2003-01-01

Sulfonation of polymers is a viable method for making proton exchange membranes used in electrochemical devices. Polyether-ether ketone was modified by using concentrated sulfuric acid (97.4%) to produce ion-containing polymers bearing HSO3 groups. The sulfonated polymer was characterized for IEC, HNMR, DSC and water uptake etc. The degree of sulfonation of sulfonated PEEK was found to vary from 40 to 80 mol%. The PEEK became amorphous after sufonation (as evidenced from DSC and WXRD), which enhanced its solubility in organic solvents such as DMF. The glass transition temperature, Tg increased from 151C for pure PEEK to 217C upon sulfonation. The water uptake was also increased with sulfonation level, which provides formation of water-mediated pathways for protons involving SO3H groups. The membranes from these polymers have a high potential for use in electrochemical devices such as polymer fuel cell and electrodialysis. (author)

L-Arginine modified multi-walled carbon nanotube/sulfonated poly(ether ether ketone) nanocomposite films for biomedical applications

Science.gov (United States)

Kaya, Hatice; Bulut, Osman; Kamali, Ali Reza; Ege, Duygu

2018-06-01

Favorable implant-tissue interactions are crucial to achieve successful osseointegration of the implants. Poly(ether ether ketone) (PEEK) is an interesting alternative to titanium in orthopedics because of its low cost, high biocompatibility and comparable mechanical properties with cancellous bone. Despite these advantages; however, the untreated surface of PEEK fails to osseointegrate due to its bioinert and hydrophobic behavior. This paper deals with the surface modification of PEEK with a novel method. For this, PEEK was first treated with concentrated sulfuric acid to prepare sulfonated PEEK (SPEEK) films using a solvent casting method. Then, 1 and 2 wt% multi-walled carbon nanotube was incorporated into SPEEK to form nanocomposite films. The samples were characterized with Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy. After successful preparation of the nanocomposite films, L-arginine was covalently conjugated on the nanocomposite films to further improve their surface properties. Subsequently, the samples were characterized using X-ray Photoemission Spectroscopy (XPS), water contact angle measurements and Atomic Force Microscopy (AFM) and Dynamic Mechanical Thermal Analysis (DMTA). Finally, cell culture studies were carried out by using Alamar Blue assay to evaluate the biocompatibility of the films. The results obtained indicate the successful preparation of L-arginine-conjugated MWCNT/SPEEK nanocomposite films. The modified surface shows potential to improve implants' mechanical and biological performances.

Non-linear Shear and Uniaxial Extensional Rheology of Polyether-Ester-Sulfonate Copolymer Ionomer Melts

DEFF Research Database (Denmark)

Shabbir, Aamir; Huang, Qian; P. Baeza, Guilhem

2017-01-01

We present unique nonlinear shear and extensional rheology data of unentan-gled amorphous polyester ionomers based on polyethers and sulphonated phthalates with sodium/ lithium counterions. Previous linear viscoelastic (LVE) measurements1 showed significant elasticity in these ionomers due...

Polyether ether ketone encased monolith frits made of polyether ether ketone tubing with a 0.25 mm opening resulting in an improved separation performance in liquid chromatography.

Science.gov (United States)

Park, Sin Young; Cheong, Won Jo

2016-05-01

Tiny polyether ether ketone encased monolith frits have been prepared by modified catalytic sulfonation of the inner surface of polyether ether tubing (1.6 mm od, 0.25 mm id) followed by modified formation of organic monolith and cutting of the tubing into slices. The frit was placed below the central hole of the column outlet union and supported by a combination of a silica capillary (0.365 mm od, 0.05 mm id) and a polyether ether ketone sleeve (1.6 mm od, 0.38 mm id) tightened with a nut and a ferrule when the column was packed to prevent sinking of the frit element into the union hole (0.25 mm opening) otherwise. The column packed this way with the frits investigated in this study has shown better separation performance owing to the reduced frit volume in comparison to the column packed with a commercial stainless-steel screen frit. This study establishes the strategy of disposable microcolumns in which cheap disposable frits are used whenever the column is re-packed to yield columns of even better chromatographic performance than the columns with commercial frits. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phase behavior in blends of ethylene oxide-propylene oxide copolymer and poly(ether sulfone) studied by modulated-temperature DSC and NMR relaxometry.

Science.gov (United States)

Van Lokeren, Luk; Gotzen, Nicolaas-Alexander; Pieters, Ronny; Van Assche, Guy; Biesemans, Monique; Willem, Rudolph; Van Mele, Bruno

2009-01-01

The state diagram of a blend consisting of a copolymer containing ethylene oxide and propylene oxide, P(EO-ran-PO), and poly(ether sulfone), PES, is constructed by using modulated-temperature differential scanning calorimetry (MTDSC), T(2) NMR relaxometry, and light scattering. The apparent heat capacity signal in MTDSC is used for the characterization of polymer miscibility and morphology development. T(2) NMR relaxometry is used to detect the onset of phase separation, which is in good agreement with the onset of phase separation in the apparent heat capacity from MTDSC and the cloud-point temperature as determined from light scattering. The coexistence curve can be constructed from T(2) values at various temperatures by using a few blends with well-chosen compositions. These T(2) values also allow the detection of the boundary between the demixing zones with and without interference of partial vitrification and are in good agreement with stepwise quasi-isothermal MTDSC heat capacity measurements. Important interphases are detected in the heterogeneous P(EO-ran-PO)/PES blends.

Ion-exchange composite membranes pore-filled with sulfonated poly(ether ether ketone) and Engelhard titanosilicate-10 for improved performance of vanadium redox flow batteries

Science.gov (United States)

Kim, Jihoon; Lee, Yongkyu; Jeon, Jae-Deok; Kwak, Seung-Yeop

2018-04-01

A series of ion-exchange membranes for vanadium redox flow batteries (VRBs) are prepared by filling the pores of a poly(tetrafluoroethylene) (PTFE) substrate with sulfonated poly(ether ether ketone) (SPEEK) and microporous Engelhard titanosilicate-10 (ETS-10). The effects of ETS-10 incorporation and PTFE reinforcement on membrane properties and VRB single-cell performance are investigated using various characterization tools. The results show that these composite membranes exhibit improved mechanical properties and reduced vanadium-ion permeabilities owing to the interactions between ETS-10 and SPEEK, the suppressed swelling of PTFE, and the unique ETS-10 framework. The composite membrane with 3 wt% ETS-10 (referred to as "SE3/P") exhibits the best membrane properties and highest ion selectivity. The VRB system with the SE3/P membrane exhibits higher cell capacity, higher cell efficiency, and lower capacity decay than that with a Nafion membrane. These results indicate that this composite membrane has potential as an alternative to Nafion in VRB systems.

Ion-Selective Ionic Polymer Metal Composite (IPMC) actuator based on crown ether containing sulfonated Poly(Arylene Ether Ketone)

NARCIS (Netherlands)

Tas, S.; Zoetebier, B.; Sukas, O.S.; Bayraktar, M.; Hempenius, M.; Vancso, G.J.; Nijmeijer, K.

2017-01-01

This study introduces the concept of ion selective actuation in polymer metal composite actuators, employing crown ether bearing aromatic polyether materials. For this purpose, sulfonated poly(arylene ether ketone) (SPAEK) and crown ether containing SPAEK with molar masses suitable for membrane

Poly(oxyethylene) electrolytes based on lithium pentafluorobenzene sulfonate

International Nuclear Information System (INIS)

Paillard, E.; Iojoiu, C.; Alloin, F.; Guindet, J.; Sanchez, J.-Y.

2007-01-01

Lithium pentafluorobenzene sulfonate was synthesized by a protocol whereby pollution by aromatic nucleophilic substitutions on the perfluorinated ring was avoided. Its poly(oxyethylene) complexes, although less conductive than lithium imide complexes, provided cationic transference numbers higher than 0.5. Surprisingly, even at fairly low concentrations, this salt markedly increased the mechanical properties of the polymer electrolyte. This effect was attributed to telechelic interactions of the ion pairs with distinct polyether chains and is in agreement with the high cationic transference numbers

Enhancement of Hybrid SPEEK Based Polymer–Cyclodextrin-Silica Inorganic Membrane for Direct Methanol Fuel Cell Application

Directory of Open Access Journals (Sweden)

Tutuk Djoko Kusworo

2017-06-01

  Keywords: Direct Methanol Fuel Cell, Poly(ether ether ketone, cyclodextrin-silica, sulfonation, ionic conductivity. Article History: Received January 18th 2017; Received in revised form April 21st 2017; Accepted June 22nd 2017; Available online How to Cite This Article: Kusworo, T.D., Hakim, M.F. and Hadiyanto, H. (2017 Enhancement of Hybrid SPEEK Based Polymer–Cyclodextrin-Silica Inorganic Membrane for Direct Methanol Fuel Cell Application. International Journal of Renewable Energy Development, 6(2, 165-170. https://doi.org/10.14710/ijred.6.2.165-170

Multilayered ion-imprinted membranes with high selectivity towards Li+ based on the synergistic effect of 12-crown-4 and polyether sulfone

Science.gov (United States)

Lu, Jian; Qin, Yingying; Zhang, Qi; Wu, Yilin; Cui, Jiuyun; Li, Chunxiang; Wang, Liang; Yan, Yongsheng

2018-01-01

High-selective multilayered Li+-imprinted membranes (Li-IIMs) with enhanced hydrophilicity and stability were developed based on polyether sulfone substrate membranes. The multilayered structure was prepared with polydopamine (pDA) as the interfacial adhesion layer, SiO2 nanoparticles as the hydrophilic layer and Li+-imprinted polymers as the imprinted layer. The selective ;Li+-recognition sites; were formed using 12-crown-4 (12C4) as the adsorbing units. The optimal relative selectivity coefficients (α) of Li+/Na+ and Li+/K+ reached up to 1.85 and 2.07 with the imprinting factor (β) of 2.51, and the high permselectivity factors (γ) of Na+/Li+ (7.39) and K+/Li+ (9.86) were achieved on Li-IIMs. The Langmuir isotherm model and the pseudo-second-order kinetics model best fitted the rebinding data of Li-IIMs, as well as the rebinding capacities reached up to 90.3% of initial binding after 5 cycles of adsorption/desorption and just declined to 88.1% after another 5 cycles a month later. Therefore, the as-prepared Li-IIMs would have potential applications for the separation of lithium ions from salt lake brines.

Synthesis and Process Optimization of Electrospun PEEK-Sulfonated Nanofibers by Response Surface Methodology

Directory of Open Access Journals (Sweden)

Carlo Boaretti

2015-07-01

Full Text Available In this study electrospun nanofibers of partially sulfonated polyether ether ketone have been produced as a preliminary step for a possible development of composite proton exchange membranes for fuel cells. Response surface methodology has been employed for the modelling and optimization of the electrospinning process, using a Box-Behnken design. The investigation, based on a second order polynomial model, has been focused on the analysis of the effect of both process (voltage, tip-to-collector distance, flow rate and material (sulfonation degree variables on the mean fiber diameter. The final model has been verified by a series of statistical tests on the residuals and validated by a comparison procedure of samples at different sulfonation degrees, realized according to optimized conditions, for the production of homogeneous thin nanofibers.

Sulfonated poly(ether ether ketone)/poly(vinyl alcohol) sensitizing system for solution photogeneration of small Ag, Au, and Cu crystallites.

Science.gov (United States)

Korchev, A S; Shulyak, T S; Slaten, B L; Gale, W F; Mills, G

2005-04-28

Illumination of air-free aqueous solutions containing sulfonated poly(ether ether ketone) and poly(vinyl alcohol) with 350 nm light results in benzophenone ketyl radicals of the polyketone. The polymer radicals form with a quantum yield 0.02 and decay with a second-order rate constant 6 orders of magnitude lower than that of typical alpha-hydroxy radicals. Evidence is presented that the polymeric benzophenone ketyl radicals reduce Ag+, Cu2+, and AuCl4- to metal particles of nanometer dimensions. Decreases in the reduction rates with increasing Ag(I), Cu(II), and Au(III) concentrations are explained using a kinetic model in which the metal ions quench the excited state of the polymeric benzophenone groups, which forms the macromolecular radicals. Quenching is fastest for Ag+, whereas Cu2+ and AuCl4- exhibit similar rate constants. Particle formation becomes more complex as the number of equivalents needed to reduce the metal ions increases; the Au(III) system is an extreme case where the radical reactions operate in parallel with secondary light-initiated and thermal reduction channels. For each metal ion, the polymer-initiated photoreactions produce crystallites possessing distinct properties, such as a very strong plasmon in the Ag case or the narrow size distribution exhibited by Au particles.

Preparation of poly(ether ether ketone)-based polymer electrolytes for fuel cell membranes using grafting technique

International Nuclear Information System (INIS)

Hasegawa, Shin; Suzuki, Yasuyuki; Maekawa, Yasunari

2008-01-01

Poly(ether ether ketone) (PEEK)-based polymer electrolyte membranes (PEMs) was successfully prepared by radiation grafting of a styrene monomer into PEEK films and the consequent selective sulfonation of the grafting chains in the film state. Using milder sulfonation, the sulfonation reactions proceeded at the grafted chains in preference to the phenylene rings of PEEK main chains; as a result, the grafted films could successfully transform to a PEM with conductivity of more than 0.1 S/cm. The ion exchange capacity (IEC) and conductivity of the grafted PEEK electrolyte membranes were controlled to the ranges of 1.2-2.9 mmol/g and 0.03-0.18 S/cm by changing the grafting degree. It should be noted that this is the first example of directly transforming super-engineering plastic films into a PEM using radiation grafting

Quantum dots-hyperbranched polyether hybrid nanospheres towards delivery and real-time detection of nitric oxide

Energy Technology Data Exchange (ETDEWEB)

Liu, Shuiping; Gu, Tianxun; Fu, Jiajia [Key Laboratory of Eco-Textiles, Ministry of Education (Jiangnan University), Wuxi 214122 (China); College of Textile and Clothing, Jiangnan University, Wuxi 214122 (China); Li, Xiaoqiang, E-mail: leecaiwei@163.com [Key Laboratory of Eco-Textiles, Ministry of Education (Jiangnan University), Wuxi 214122 (China); College of Textile and Clothing, Jiangnan University, Wuxi 214122 (China); Technical University of Denmark, DTU Food, Søltofts plads, B227, 2800 Kgs. Lyngby (Denmark); Chronakis, Ioannis S. [Technical University of Denmark, DTU Food, Søltofts plads, B227, 2800 Kgs. Lyngby (Denmark); Ge, Mingqiao [Key Laboratory of Eco-Textiles, Ministry of Education (Jiangnan University), Wuxi 214122 (China); College of Textile and Clothing, Jiangnan University, Wuxi 214122 (China)

2014-12-01

In this work, novel hybrid nanosphere vehicles were synthesized for nitric oxide (NO) donating and real-time detection. The hybrid nanosphere vehicles consist of cadmium selenide quantum dots (CdSe QDs) as NO fluorescent probes, and the modified hyperbranched polyether (mHP)-based diazeniumdiolates as NO donors, respectively. The nanospheres have spherical outline with dimension of ∼ 127 nm. The data of systematic characterization demonstrated that the mHP-based hybrid nanosphere vehicles (QDs-mHP-NO) can release and real-time detect NO with the low limit of 25 nM, based on fluorescence quenching mechanism. The low cell-toxicity of QDs-mHP-NO nanospheres was verified by means of MTT assay on L929 cells viability. The QDs-mHP-NO nanospheres provide perspectives for designing a new class of biocompatible NO donating and imaging systems. - Highlights: • QDs-mHP-NO fluorescent probe was prepared. • The QDs-mHP-NO probe is capable of releasing NO. • The QDs-mHP-NO probe can quantitatively detecting the release of NO in real time. • The low cell-toxicity of QDs-mHP-NO nanospheres was verified.

Polymer-inorganic hybrid proton conductive membranes: Effect of the interfacial transfer pathways

International Nuclear Information System (INIS)

Chen, Pingping; Hao, Lie; Wu, Wenjia; Li, Yifan; Wang, Jingtao

2016-01-01

Highlights: • A series of hybrid membranes are prepared using fillers with different structures. • The fillers (0-D, 1-D, and 2-D) are sulfonated to ensure close surface component. • The effect of filler’s structure on microstructure of hydrid membrane is explored. • For single-kind filler series, 2-D filler has the strongest conduction promotion. • The synergy effect of different kinds of fillers is systematacially investigated. - Abstract: For hybrid membrane, the polymer-inorganic interface along filler surface can be facilely created to be distinctive and controllable pathway for mass transfer. Herein, three kinds of fillers are used as inorganic additives including zero-dimensional silica (0-D, SiO_2), one-dimensional halloysite nanotube (1-D, HNT), and two-dimensional graphene oxide (2-D, GO), which are functionalized by sulfonated polymer layer to ensure close surface component. Then the fillers are incorporated into two types of polymer matrixes (phase-separated sulfonated poly(ether ether ketone) and non-phase-separated chitosan) to prepare three series of hybrid membranes with single-kind filler, double-kinds fillers, or triple-kinds fillers, respectively. The microstructures, physicochemical properties, and proton conduction properties (under hydrated and anhydrous conditions) of the membranes are extensively investigated. It is found that (i) for the single-kind filler-filled membranes, 2-D filler has the strongest promotion ability for proton conductivity of membrane due to the constructed wide and long-range pathways for proton transfer; (ii) while for the hybrid membranes with double-kinds fillers, instead of synergistic promotion effect, the fillers cause more tortuous transfer pathways within membranes and then decrease proton conductivity; (iii) the hybrid membranes with triple-kinds fillers exhibit similar behavior but a little higher conductivity than the membranes with double-kinds fillers.

Synthesis,crystal structure and properties of inorganic-organic hybrid polymers based on 8-hydroxylquinoline-5-sulfonic acid

Institute of Scientific and Technical Information of China (English)

无

2009-01-01

Two new inorganic-organic hybrid polymers, Mn(QS)(H2O) (1) and Co(QS)(H2O)2 (2) (H2QS=8-hydroxyl-quinoline-5-sulfonic acid), based on 8-hydroxylquinoline-5-sulfonate ligand, have been synthesized under solvothermal conditions and their structures were solved by single-crystal X-ray diffraction analysis. Compound 1 is a three-dimensional open framework with rutile topology structure, and compound 2 is a three-dimensional supramolecular structure. These compounds were characterized by powder XRD, infrared spectroscopy, thermogravimetric analysis, fluorescence properties and magnetism properties.

Microbial desalination cell with sulfonated sodium poly(ether ether ketone) as cation exchange membranes for enhancing power generation and salt reduction.

Science.gov (United States)

Moruno, Francisco Lopez; Rubio, Juan E; Atanassov, Plamen; Cerrato, José M; Arges, Christopher G; Santoro, Carlo

2018-06-01

Microbial desalination cell (MDC) is a bioelectrochemical system capable of oxidizing organics, generating electricity, while reducing the salinity content of brine streams. As it is designed, anion and cation exchange membranes play an important role on the selective removal of ions from the desalination chamber. In this work, sulfonated sodium (Na + ) poly(ether ether ketone) (SPEEK) cation exchange membranes (CEM) were tested in combination with quaternary ammonium chloride poly(2,6-dimethyl 1,4-phenylene oxide) (QAPPO) anion exchange membrane (AEM). Non-patterned and patterned (varying topographical features) CEMs were investigated and assessed in this work. The results were contrasted against a commercially available CEM. This work used real seawater from the Pacific Ocean in the desalination chamber. The results displayed a high desalination rate and power generation for all the membranes, with a maximum of 78.6±2.0% in salinity reduction and 235±7mWm -2 in power generation for the MDCs with the SPEEK CEM. Desalination rate and power generation achieved are higher with synthesized SPEEK membranes when compared with an available commercial CEM. An optimized combination of these types of membranes substantially improves the performances of MDC, making the system more suitable for real applications. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Stabilized Sulfonated Aromatic Polymers by in situ Solvothermal Cross-Linking

Energy Technology Data Exchange (ETDEWEB)

Di Vona, Maria Luisa, E-mail: divona@uniroma2.it; Sgreccia, Emanuela [Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Rome (Italy); Narducci, Riccardo; Pasquini, Luca [Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Rome (Italy); MAtériaux Divisés, Interfaces, Réactivité, ELectrochimie (MADIREL – UMR 7246), Aix Marseille Université, Marseille (France); Hou, Hongying [Faculty of Material and Engineering, Kunming University of Science and Technology, Kunming (China); Knauth, Philippe [MAtériaux Divisés, Interfaces, Réactivité, ELectrochimie (MADIREL – UMR 7246), Aix Marseille Université, Marseille (France)

2014-10-10

The cross-link reaction via sulfone bridges of sulfonated polyether ether ketone (SPEEK) by thermal treatment at 180°C in presence of dimethylsulfoxide is discussed. The modifications of properties subsequent to the cross-linking are presented. The mechanical strength as well as the hydrolytic stability increased with the thermal treatment time, i.e., with the degree of cross-linking. The proton conductivity was determined as function of temperature, IEC, degree of cross-linking, and hydration number. The memory effect, which is the membrane ability to “remember” the water uptake reached at high temperature also at lower temperature, is exploited in order to achieve high values of conductivity. Membranes swelled at 110°C can reach a conductivity of 0.14 S/cm at 80°C with a hydration number (λ) of 73.

Salinomycin Hydroxamic Acids: Synthesis, Structure, and Biological Activity of Polyether Ionophore Hybrids.

Science.gov (United States)

Borgström, Björn; Huang, Xiaoli; Chygorin, Eduard; Oredsson, Stina; Strand, Daniel

2016-06-09

The polyether ionophore salinomycin has recently gained attention due to its exceptional ability to selectively reduce the proportion of cancer stem cells within a number of cancer cell lines. Efficient single step strategies for the preparation of hydroxamic acid hybrids of this compound varying in N- and O-alkylation are presented. The parent hydroxamic acid, salinomycin-NHOH, forms both inclusion complexes and well-defined electroneutral complexes with potassium and sodium cations via 1,3-coordination by the hydroxamic acid moiety to the metal ion. A crystal structure of an cationic sodium complex with a noncoordinating anion corroborates this finding and, moreover, reveals a novel type of hydrogen bond network that stabilizes the head-to-tail conformation that encapsulates the cation analogously to the native structure. The hydroxamic acid derivatives display down to single digit micromolar activity against cancer cells but unlike salinomycin selective reduction of ALDH(+) cells, a phenotype associated with cancer stem cells was not observed. Mechanistic implications are discussed.

Increasing the proton conductivity of sulfonated polyether ether ketone by incorporating graphene oxide: Morphology effect on proton dynamics

Science.gov (United States)

Leong, Jun Xing; Diño, Wilson Agerico; Ahmad, Azizan; Daud, Wan Ramli Wan; Kasai, Hideaki

2018-03-01

We synthesized graphene oxide-sulfonated polyether ether ketone (GO-SPEEK) composite membrane and compare its proton conductivity with that of Nafion® 117 and SPEEK membranes. From experimental measurements, we found that GO-SPEEK has better proton conductivity (σGO-SPEEK = 3.8 × 10-2 S cm-1) when compared to Nafion® 117 (σNafion = 2.4 × 10-2 S cm-1) and SPEEK (σSPEEK = 2.9 × 10-3 S cm-1). From density functional theory (DFT-) based total energy calculations, we found that GO-SPEEK has the shortest proton diffusion distance among the three membranes, yielding the highest tunneling probability. Hence, GO-SPEEK exhibits the highest conductivity. The short proton diffusion distance in GO-SPEEK, as compared to Nafion® 117 and SPEEK, can be attributed to the presence of oxygenated functional groups of GO in the polymer matrix. This also explains why GO-SPEEK requires the lowest hydration level to reach its maximum conductivity. Moreover, we have successfully shown that the proton conductivity σ is related to the tunneling probability T, i.e., σ = σ‧ exp(-1/T). We conclude that the proton diffusion distance and hydration level are the two most significant factors that determine the membrane’s good conductivity. The distance between ionic sites of the membrane should be small to obtain good conductivity. With this short distance, lower hydration level is required. Thus, a membrane with short separation between the ionic sites can have enhanced conductivity, even at low hydration conditions.

Polyether matrices for lithium generators; Matrices polyethers pour generateurs au lithium

Energy Technology Data Exchange (ETDEWEB)

Alloin, F.; Sanchez, J.Y. [Laboratoire d`Electrochimie et de Physicochimie des Materiaux et des Interfaces, 38 - Saint-Martin-d`Heres (France)

1996-12-31

The use of solvating polymers of polyether type is an interesting solution for the manufacturing of high capacity lithium batteries with lithium metal anodes and which can operate at T > 50 deg. C. These operating conditions are perfectly compatible with electric-powered vehicle and stationary battery applications. In order to improve the ionic conductivity of polymer electrolytes, new aprotic and amorphous polyether lattices have been synthesized having a good conductivity but also good thermal, mechanical and electrochemical stabilities. Two type of 3-D polyether lattices obtained by reticulation of linear pre-polymers have been selected as host polymers: unsaturated poly-condensate and unsaturated co-polyethers. (J.S.) 18 refs.

Polyether matrices for lithium generators; Matrices polyethers pour generateurs au lithium

Energy Technology Data Exchange (ETDEWEB)

Alloin, F; Sanchez, J Y [Laboratoire d` Electrochimie et de Physicochimie des Materiaux et des Interfaces, 38 - Saint-Martin-d` Heres (France)

1997-12-31

The use of solvating polymers of polyether type is an interesting solution for the manufacturing of high capacity lithium batteries with lithium metal anodes and which can operate at T > 50 deg. C. These operating conditions are perfectly compatible with electric-powered vehicle and stationary battery applications. In order to improve the ionic conductivity of polymer electrolytes, new aprotic and amorphous polyether lattices have been synthesized having a good conductivity but also good thermal, mechanical and electrochemical stabilities. Two type of 3-D polyether lattices obtained by reticulation of linear pre-polymers have been selected as host polymers: unsaturated poly-condensate and unsaturated co-polyethers. (J.S.) 18 refs.

The influence of mesoscopic confinement on the dynamics of imidazolium-based room temperature ionic liquids in polyether sulfone membranes

Science.gov (United States)

Thomaz, Joseph E.; Bailey, Heather E.; Fayer, Michael D.

2017-11-01

The structural dynamics of a series of 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (CnmimNTf2, n = 2, 4, 6, 10: ethyl—Emim; butyl—Bmim; hexyl—Hmim; decyl—Dmim) room temperature ionic liquids confined in the pores of polyether sulfone (PES 200) membranes with an average pore size of ˜350 nm and in the bulk liquids were studied. Time correlated single photon counting measurements of the fluorescence of the fluorophore coumarin 153 (C153) were used to observe the time-dependent Stokes shift (solvation dynamics). The solvation dynamics of C153 in the ionic liquids are multiexponential decays. The multiexponential functional form of the decays was confirmed as the slowest decay component of each bulk liquid matches the slowest component of the liquid dynamics measured by optical heterodyne-detected optical Kerr effect (OHD-OKE) experiments, which is single exponential. The fact that the slowest component of the Stokes shift matches the OHD-OKE data in all four liquids identifies this component of the solvation dynamics as arising from the complete structural randomization of the liquids. Although the pores in the PES membranes are large, confinement on the mesoscopic length scale results in substantial slowing of the dynamics, a factor of ˜4, for EmimNTf2, with the effect decreasing as the chain length increases. By DmimNTf2, the dynamics are virtually indistinguishable from those in the bulk liquid. The rotation relaxation of C153 in the four bulk liquids was also measured and showed strong coupling between the C153 probe and its environment.

Anhydrous proton exchange membrane of sulfonated poly(ether ether ketone) enabled by polydopamine-modified silica nanoparticles

International Nuclear Information System (INIS)

Wang, Jingtao; Bai, Huijuan; Zhang, Haoqin; Zhao, Liping; Chen, Huiling; Li, Yifan

2015-01-01

Highlights: • The concept of acid/base pairs was employed to design anhydrous PEMs. • Polydopamine-modified silica particles were uniformly dispersed in SPEEK membrane. • The membranes displayed enhancement in both stability and anhydrous proton conductivity. - Abstract: Novel anhydrous proton exchange membrane is (PEM) facilely prepared by embedding dopamine-modified silica nanoparticles (DSiOis 2 ) into sulfonated poly (ether ether ketone) (SPEEK) polymer matrix. DSiO 2 bearing -NH 2 /-NH- groups are synthesized inspired by the bioadhesion principle, which are uniformly dispersed within SPEEK membrane due to the good interfacial compatibility. The interfacial electrostatic attractions render unique rearrangement of the nanophase-separated structure and the chain packing of the resultant hybrid membranes. As a result, the thermal and mechanical stabilities as well as structural stability of the hybrid membranes are enhanced when compared to SPEEK control membrane. On the other hand, induced by the attractions, acid–base pairs are formed at the SPEEK/DSiOarewere 2 interface, where fast proton transfer via Grotthuss mechanism is expected. These features confer much higher proton conductivities on the DSiO 2 -filled membranes under both hydrated and anhydrous conditions, compared to those of the SPEEK control membrane and SiO 2 -filled membranes. Particularly, the hybrid membrane with 15 wt% DSiO 2 achieve the highest conductivities of 4.52achieveachieved × 10 −3 S cm −1 at 120 °C under anhydrous condition, which is much higher than the SPEEK control membrane and the commercial Nafion membrane (0.1iswas × 10 −3 S cm −1 ). The membrane with 9 wt% DSiO 2 show an open cell potential of 0.98showshowed V and an optimum power density of 111.7 mW cm −2 , indicative of its potential application in fuel cell under anhydrous condition

The enzymology of polyether biosynthesis.

Science.gov (United States)

Liu, Tiangang; Cane, David E; Deng, Zixin

2009-01-01

Polyether ionophore antibiotics are a special class of polyketides widely used in veterinary medicine, and as food additives in animal husbandry. In this article, we review current knowledge about the mechanism of polyether biosynthesis, and the genetic and biochemical strategies used for its study. Several clear differences distinguish it from traditional type I modular polyketide biosynthesis: polyether backbones are assembled by modular polyketide synthases but are modified by two key enzymes, epoxidase and epoxide hydrolase, to generate the product. All double bonds involved in the oxidative cyclization in the polyketide backbone are of E geometry. Chain release in the polyether biosynthetic pathway requires a special type II thioesterase which specifically hydrolyzes the polyether thioester. All these discoveries should be very helpful for a deep understanding of the biosynthetic mechanism of this class of important natural compounds, and for the targeted engineering of polyether derivatives.

A New Microextraction Technique for the Assay of Alkaloids in Chinese Compound Formula-Based Polyether Sulfone Membrane Fiber Decorated by TiO2 Nanoparticles.

Science.gov (United States)

Sun, Xinjie; Wei, Yingqin; Hou, Baojuan; Zhou, Guowei

2017-03-01

A new nanocomposite membrane was used to clean up impurities from complex samples and the obvious synergy was obtained in this paper. The nanocomposite membrane was prepared by dispersing TiO2 nanoparticles in chloroform and filled in the pores and lumen of polyether sulfone membrane fiber. The novel microextraction method showed the ideal selective extraction effect for alkaloids in the formulae composed of Rhizoma coptidis and the excellent clean-up efficiency compared with the single membrane method. The optimum extraction conditions were as follows: chloroform as accepted phase; the number of nanocomposite membrane fiber bars, 7; extraction time, 30 min; pH of the sample solution, 10.55; desorption solvent, methanol. The limit of detection for the described alkaloids was estimated at 0.122 μg mL-1. The recovery of the four alkaloids in complex samples ranged from 93.24% to 97.94% with relative standard deviation of <4.99 (n = 5). The validated method had been successfully applied to study the transfer rate of alkaloids in the producing process of Qihuang capsule and the ideal transfer rate of alkaloids was obtained in this paper. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Biosynthetic machinery of ionophore polyether lasalocid: enzymatic construction of polyether skeleton.

Science.gov (United States)

Minami, Atsushi; Oguri, Hiroki; Watanabe, Kenji; Oikawa, Hideaki

2013-08-01

Diversity of natural polycyclic polyethers originated from very simple yet versatile strategy consisting of epoxidation of linear polyene followed by epoxide opening cascade. To understand two-step enzymatic transformations at molecular basis, a flavin containing monooxygenase (EPX) Lsd18 and an epoxide hydrolase (EH) Lsd19 were selected as model enzymes for extensive investigation on substrate specificity, catalytic mechanism, cofactor requirement and crystal structure. This pioneering study on prototypical lasalocid EPX and EH provides insight into detailed mechanism of ionophore polyether assembly machinery and clarified remaining issues for polyether biosynthesis. Copyright © 2013 Elsevier Ltd. All rights reserved.

Polyether-polyester graft copolymer

Science.gov (United States)

Bell, Vernon L. (Inventor)

1987-01-01

Described is a polyether graft polymer having improved solvent resistance and crystalline thermally reversible crosslinks. The copolymer is prepared by a novel process of anionic copolymerization. These polymers exhibit good solvent resistance and are well suited for aircraft parts. Previous aromatic polyethers, also known as polyphenylene oxides, have certain deficiencies which detract from their usefulness. These commercial polymers are often soluble in common solvents including the halocarbon and aromatic hydrocarbon types of paint thinners and removers. This limitation prevents the use of these polyethers in structural articles requiring frequent painting. In addition, the most popular commercially available polyether is a very high melting plastic. This makes it considerably more difficult to fabricate finished parts from this material. These problems are solved by providing an aromatic polyether graft copolymer with improved solvent resistance and crystalline thermally reversible crosslinks. The graft copolymer is formed by converting the carboxyl groups of a carboxylated polyphenylene oxide polymer to ionic carbonyl groups in a suitable solvent, reacting pivalolactone with the dissolved polymer, and adding acid to the solution to produce the graft copolymer.

Partially Fluorinated Sulfonated Poly(ether amide Fuel Cell Membranes: Influence of Chemical Structure on Membrane Properties

Directory of Open Access Journals (Sweden)

Chulsung Bae

2011-01-01

Full Text Available A series of fluorinated sulfonated poly (ether amides (SPAs were synthesized for proton exchange membrane fuel cell applications. A polycondensation reaction of 4,4’-oxydianiline, 2-sulfoterephthalic acid monosodium salt, and tetrafluorophenylene dicarboxylic acids (terephthalic and isophthalic or fluoroaliphatic dicarboxylic acids produced SPAs with sulfonation degrees of 80–90%. Controlling the feed ratio of the sulfonated and unsulfonated dicarboxylic acid monomers afforded random SPAs with ion exchange capacities between 1.7 and 2.2 meq/g and good solubility in polar aprotic solvents. Their structures were characterized using NMR and FT IR spectroscopies. Tough, flexible, and transparent films were obtained with dimethylsulfoxide using a solution casting method. Most SPA membranes with 90% sulfonation degree showed high proton conductivity (>100 mS/cm at 80 °C and 100% relative humidity. Among them, two outstanding ionomers (ODA-STA-TPA-90 and ODA-STA-IPA-90 showed proton conductivity comparable to that of Nafion 117 between 40 and 80 °C. The influence of chemical structure on the membrane properties was systematically investigated by comparing the fluorinated polymers to their hydrogenated counterparts. The results suggest that the incorporation of fluorinated moieties in the polymer backbone of the membrane reduces water absorption. High molecular weight and the resulting physical entanglement of the polymers chains played a more important role in improving stability in water, however.

Ion-Exchange-Induced Selective Etching for the Synthesis of Amino-Functionalized Hollow Mesoporous Silica for Elevated-High-Temperature Fuel Cells

DEFF Research Database (Denmark)

Zhang, Jin; Liu, Jian; Lu, Shanfu

2017-01-01

is verified through a successful synthesis of hollow mesoporous silica. After infiltration with phosphotungstic acid (PWA), PWA–NH2–HMS nanoparticles are dispersed in the poly(ether sulfone)–polyvinylpyrrolidone (PES–PVP) matrix, forming a hybrid PWA–NH2–HMS/PES–PVP nanocomposite membrane. The resultant...

Luminescent hybrid lanthanide sulfates and lanthanide sulfonate-carboxylates with 1,10-phenanthroline involving in-situ oxidation of 2-mercaptonbenzoic acid

International Nuclear Information System (INIS)

Zhong, Jie-Cen; Wan, Fang; Sun, Yan-Qiong; Chen, Yi-Ping

2015-01-01

A series of lanthanide sulfates and lanthanide sulfonate-carboxylates, [Ln 2 (phen) 2 (SO 4 ) 3 (H 2 O) 2 ] n (I:Ln=Nd(1a), Sm(1b), Eu(1c), phen=1,10-phenanthroline) and [Ln(phen)(2-SBA)(BZA)] n (II: Ln=Sm(2a), Eu(2b), Dy(2c), 2-SBA=2-sulfobenzoate, BZA=benzoate) have been hydrothermally synthesized from lanthanide oxide, 2-mercaptonbenzoic acid with phen as auxiliary ligand and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, TG analyses and luminescence spectroscopy. Interestingly, SO 4 2− anions in I came from the in situ deep oxidation of thiol groups of 2-mercaptonbenzoic acid while 2-sulfobenzoate and benzoate ligands in II from the middle oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. Compounds I are organic–inorganic hybrid lanthanide sulfates, which have rare one-dimensional column-like structures. Complexes II are binuclear lanthanide sulfonate-carboxylates with 2-sulfobenzoate and benzoate as bridges and 1,10-phenanthroline as terminal. Photoluminescence studies reveal that complexes I and II exhibit strong lanthanide characteristic emission bands in the solid state at room temperature. - Graphical abstract: Lanthanide sulfates and lanthanide sulfonate-carboxylates have been hydrothermally synthesized. Interestingly, sulfate anions, 2-sulfobenzoate and benzoate ligands came from the in situ oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. - Highlights: • In situ oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. • The organic–inorganic hybrid lanthanide sulfates with one-dimensional column-like structure. • The dinuclear lanthanide sulfonate-carboxylates. • The emission spectra exhibit the characteristic transition of 5 D 0 → 7 F J (J=0–4) of the Eu(III)

Treatment of two different water resources in desalination and microbial fuel cell processes by poly sulfone/Sulfonated poly ether ether ketone hybrid membrane

International Nuclear Information System (INIS)

Ghasemi, Mostafa; Wan Daud, Wan Ramli; Alam, Javed; Ilbeygi, Hamid; Sedighi, Mehdi; Ismail, Ahmad Fauzi; Yazdi, Mohammad H.; Aljlil, Saad A.

2016-01-01

The PS (Polysulfone)/SPEEK (sulfonated poly ether ether ketone) hybrid membranes were fabricated and modified with low and high DS (degrees of sulfonation) for the desalination of brackish water and proton exchange membrane in microbial fuel cell. The results illustrated that SPEEK has changed the morphology of membranes and increase their hydrophilicity. PS/SPEEK with lower DS (29%) had the rejection percentage of 62% for NaCl and 68% for MgSO_4; while it was 67% and 81% for PS/SPEEK (76%) at 4 bars. Furthermore, the water flux for PS at 10 bar was 12.41 L m"−"2 h"−"1. It was four times higher for PS/SPEEK (29%) which means 49.5 L m"−"2 h"−"1 and 13 times higher for PS/SPEEK (76%) with means 157.76 L m"−"2 h"−"1. However, in MFC (microbial fuel cell), the highest power production was 97.47 mW/m"2 by PS/SPEEK (29%) followed by 41.42 mW/m"2 for PS/SPEEK (76%), and 9.4 mW/m"2 for PS. This revealed that the sulfonation of PEEK (poly ether ether ketone) made it a better additive for PS for desalination, because it created a membrane with higher hydrophilicity, better pore size and better for salt rejection. Although for the separator, the degree of sulfonation was limited; otherwise it made a membrane to transfer some of the unwanted ions. - Highlights: • Fabrication of a composite membrane for desalination and MFC. • PS/SPEEK (76%) had the lowest contact angle (48.8) and highest hydrophilicity than PS and PS/SPEEK (29%). • PS/SPEEK (29%) was the best separator for use in MFC. • PS/SPEEK (76%) had the highest flux (61.3 L m"−"2 h"−"1) for desalination.

40 CFR 721.405 - Polyether acrylate.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyether acrylate. 721.405 Section... § 721.405 Polyether acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polyether acrylate (PMN P-95-666) is subject to...

Nanostructured membranes and electrodes with sulfonic acid functionalized carbon nanotubes

KAUST Repository

Tripathi, Bijay Prakash; Schieda, Mauricio; Shahi, Vinod Kumar; Nunes, Suzana Pereira

2011-01-01

Herein we report the covalent functionalization of multiwall carbon nanotubes by grafting sulfanilic acid and their dispersion into sulfonated poly(ether ether ketone). The nanocomposites were explored as an option for tuning the proton and electron conductivity, swelling, water and alcohol permeability aiming at nanostructured membranes and electrodes for application in alcohol or hydrogen fuel cells and other electrochemical devices. The nanocomposites were extensively characterized, by studying their physicochemical and electrochemical properties. They were processed as self-supporting films with high mechanical stability, proton conductivity of 4.47 × 10 -2 S cm-1 at 30 °C and 16.8 × 10-2 S cm-1 at 80 °C and 100% humidity level, electron conductivity much higher than for the plain polymer. The methanol permeability could be reduced to 1/20, keeping water permeability at reasonable values. The ratio of bound water also increases with increasing content of sulfonated filler, helping in keeping water in the polymer in conditions of low external humidity level. © 2010 Elsevier B.V.

Nanostructured membranes and electrodes with sulfonic acid functionalized carbon nanotubes

KAUST Repository

Tripathi, Bijay Prakash

2011-02-01

Herein we report the covalent functionalization of multiwall carbon nanotubes by grafting sulfanilic acid and their dispersion into sulfonated poly(ether ether ketone). The nanocomposites were explored as an option for tuning the proton and electron conductivity, swelling, water and alcohol permeability aiming at nanostructured membranes and electrodes for application in alcohol or hydrogen fuel cells and other electrochemical devices. The nanocomposites were extensively characterized, by studying their physicochemical and electrochemical properties. They were processed as self-supporting films with high mechanical stability, proton conductivity of 4.47 × 10 -2 S cm-1 at 30 °C and 16.8 × 10-2 S cm-1 at 80 °C and 100% humidity level, electron conductivity much higher than for the plain polymer. The methanol permeability could be reduced to 1/20, keeping water permeability at reasonable values. The ratio of bound water also increases with increasing content of sulfonated filler, helping in keeping water in the polymer in conditions of low external humidity level. © 2010 Elsevier B.V.

High temperature resistant nanofiber by bubbfil-spinning

Directory of Open Access Journals (Sweden)

Li Ya

2015-01-01

Full Text Available Heat-resisting nanofibers have many potential applications in various industries, and the bubbfil spinning is the best candidate for mass-production of such materials. Polyether sulfone/zirconia solution with a bi-solvent system is used in the experiment. Experimental result reveals that polyether sulfone/zirconia nanofibers have higher resistance to high temperature than pure polyether sulfone fibers, and can be used as high-temperature-resistant filtration materials.

Sulfonated macro-RAFT agents for the surfactant-free synthesis of cerium oxide-based hybrid latexes.

Science.gov (United States)

Garnier, Jérôme; Warnant, Jérôme; Lacroix-Desmazes, Patrick; Dufils, Pierre-Emmanuel; Vinas, Jérôme; van Herk, Alex

2013-10-01

Three types of amphiphatic macro-RAFT agents were employed as compatibilizers to promote the polymerization reaction at the surface of nanoceria for the synthesis of CeO2-based hybrid latexes. Macro-RAFT copolymers and terpolymers were first synthesized employing various combinations of butyl acrylate as a hydrophobic monomer and acrylic acid (AA) and/or 2-acrylamido-2-methylpropane sulfonic acid (AMPS) as hydrophilic monomers. After characterizing the adsorption of these macro-RAFT agents at the cerium oxide surface by UV-visible spectrometry, emulsion copolymerization reactions of styrene and methyl acrylate were then carried out in the presence of the surface-modified nanoceria. Dynamic Light Scattering and cryo-Transmission Electron Microscopy were employed to confirm the hybrid structure of the final CeO2/polymer latexes, and proved that the presence of acrylic acid units in amphiphatic macro-RAFT agents enabled an efficient formation of hybrid structures, while the presence of AMPS units, when combined with AA units, resulted in a better distribution of cerium oxide nanoclusters between latex particles. Copyright © 2013 Elsevier Inc. All rights reserved.

Preparation and antibacterial properties of hybrid-zirconia films with silver nanoparticles

International Nuclear Information System (INIS)

Azócar, Ignacio; Vargas, Esteban; Duran, Nicole; Arrieta, Abel; González, Evelyn

2012-01-01

The antimicrobial effect of incorporating silver nanoparticles (AgNps) into zirconia matrix–polyether glycol was studied. AgNps of 4–6 nm in size were synthesized using the inverse micelles method, and different doses of metallic nanoparticles were incorporated into zirconia–polyether glycol mixtures during the ageing procedure. Atomic force microscopy (AFM) of the modified hybrid film showed a homogenous distribution of 20–80 nm diameter AgNps, indicating agglomeration of these structures during film modification; such agglomerations were greater when increasing the dosage of the colloidal system. The AgNps-hybrid films showed higher antimicrobial activity against Gram-positive bacteria than for Gram-negative bacteria. Hybrid films prepared with dioctyl sodium sulfosuccinate (AOT) stabilized AgNps presented enhanced antibacterial activity compared to that obtained through the addition of a high AgNO 3 concentration (0.3 wt%). -- Graphical abstract: Atomic Force Micrographs, top and cross section view, showing silver nanoparticles embedded in a zirconia–polyether glycol hybrid film. Highlights: ► Antibacterial activity of films (zirconia–polyether glycol) modified with silver nanoparticles. ► Biofilm formation is prevented. ► High sensibility against gram positive bacteria.

Preparation and antibacterial properties of hybrid-zirconia films with silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Azocar, Ignacio, E-mail: manuel.azocar@usach.cl [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Vargas, Esteban [Facultad de Ingenieria, Departamento de Metalurgia, Universidad de Santiago de Chile, USACH (Chile); Duran, Nicole [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Arrieta, Abel [Departamento de Biologia, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH (Chile); Gonzalez, Evelyn [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Facultad de Ingenieria, Departamento de Metalurgia, Universidad de Santiago de Chile, USACH (Chile); Departamento de Biologia, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH (Chile); Departamento de Quimica Farmacologica y Toxicologica, Facultad de Ciencias Quimicas, Universidad de Chile, Sergio Livingstone Polhammer 1007, Santiago (Chile); and others

2012-11-15

The antimicrobial effect of incorporating silver nanoparticles (AgNps) into zirconia matrix-polyether glycol was studied. AgNps of 4-6 nm in size were synthesized using the inverse micelles method, and different doses of metallic nanoparticles were incorporated into zirconia-polyether glycol mixtures during the ageing procedure. Atomic force microscopy (AFM) of the modified hybrid film showed a homogenous distribution of 20-80 nm diameter AgNps, indicating agglomeration of these structures during film modification; such agglomerations were greater when increasing the dosage of the colloidal system. The AgNps-hybrid films showed higher antimicrobial activity against Gram-positive bacteria than for Gram-negative bacteria. Hybrid films prepared with dioctyl sodium sulfosuccinate (AOT) stabilized AgNps presented enhanced antibacterial activity compared to that obtained through the addition of a high AgNO{sub 3} concentration (0.3 wt%). -- Graphical abstract: Atomic Force Micrographs, top and cross section view, showing silver nanoparticles embedded in a zirconia-polyether glycol hybrid film. Highlights: Black-Right-Pointing-Pointer Antibacterial activity of films (zirconia-polyether glycol) modified with silver nanoparticles. Black-Right-Pointing-Pointer Biofilm formation is prevented. Black-Right-Pointing-Pointer High sensibility against gram positive bacteria.

Pengerasan Pada Bahan Cetak Elastomer Polyether

OpenAIRE

Azree Zayani M.S.

2011-01-01

Bahan cetak polyether merupakan bahan elastomer yang digunakan di kedokteran gigi. Terdapat empat kelas menurut konsistensi dan viskositas yaitu (1) light body (2)medium atau regular body (3) heavy body: dan (4) Putty. Komposisi bahan cetak polyether terdiri dari pasta base dan pasta katalis. Pasta base mengandung polimer polyether, kolloidal silika sebagai bahan pengisi, dan plastisizer yaitu glikoeter atau phthalate. Pasta katalis mengandung alkil aromatik sulfonat ditambah dengan baha...

Preliminary Study of the Use of Sulphonated Polyether Ether Ketone (SPEEK as Proton Exchange Membrane for Microbial Fuel Cell (MFC

Directory of Open Access Journals (Sweden)

Dani Permana

2018-02-01

Full Text Available Sulfonated polyether ether ketone (SPEEK was utilized as a proton exchange membrane (PEM in Microbial Fuel Cell (MFC. The SPEEK performance in producing electricity had been observed in MFC using wastewater and glucose as substrates. The MFC with catering and tofu wastewater produced maximum power density about 0.31 mW/m2 and 0.03 mW/m2, respectively, lower that of MFC with tapioca average power density of 39.4 W/m2 over 48 h. The power density boosted because of the presence of Saccharomyces cerevisiae as inoculum. The study using of S. cerevisiae and Acetobacter acetii, separately, were also conducted in with glucose as substrate. The MFC produced an average power densities were 7.3 and 6.4 mW/m2 for S. cerevisiae and A. acetii, respectively. The results of this study indicated that SPEEK membrane has the potential usage in MFCs and can substitute the commercial membrane, Nafion. Article History: Received: Juni 14th 2017; Received: Sept 25th 2017; Accepted: December 16th 2017; Available online How to Cite This Article: Putra, H.E., Permana, D and Djaenudin, D. (2018 Preliminary Study of the Use of Sulfonated Polyether Ether Ketone (SPEEK as Proton Exchange Membrane for Microbial Fuel Cell (MFC. International Journal of Renewable Energy Development, 7(1, 7-12. https://doi.org/10.14710/ijred.7.1.7-12

21 CFR 177.2430 - Polyether resins, chlorinated.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyether resins, chlorinated. 177.2430 Section 177... Components of Articles Intended for Repeated Use § 177.2430 Polyether resins, chlorinated. Chlorinated polyether resins may be safely used as articles or components of articles intended for repeated use in...

Electrospray ionization tandem mass spectrometry of ammonium cationized polyethers.

Science.gov (United States)

Nasioudis, Andreas; Heeren, Ron M A; van Doormalen, Irene; de Wijs-Rot, Nicolette; van den Brink, Oscar F

2011-05-01

Quaternary ammonium salts (Quats) and amines are known to facilitate the MS analysis of high molar mass polyethers by forming low charge state adduct ions. The formation, stability, and behavior upon collision-induced dissociation (CID) of adduct ions of polyethers with a variety of Quats and amines were studied by electrospray ionization quadrupole time-of-flight, quadrupole ion trap, and linear ion trap tandem mass spectrometry (MS/MS). The linear ion trap instrument was part of an Orbitrap hybrid mass spectrometer that allowed accurate mass MS/MS measurements. The Quats and amines studied were of different degree of substitution, structure, and size. The stability of the adduct ions was related to the structure of the cation, especially the amine's degree of substitution. CID of singly/doubly charged primary and tertiary ammonium cationized polymers resulted in the neutral loss of the amine followed by fragmentation of the protonated product ions. The latter reveals information about the monomer unit, polymer sequence, and endgroup structure. In addition, the detection of product ions retaining the ammonium ion was observed. The predominant process in the CID of singly charged quaternary ammonium cationized polymers was cation detachment, whereas their doubly charged adduct ions provided the same information as the primary and tertiary ammonium cationized adduct ions. This study shows the potential of specific amines as tools for the structural elucidation of high molar mass polyethers. © American Society for Mass Spectrometry, 2011

[A survey of occupational health among polyether-exposed workers].

Science.gov (United States)

Fu, Xu-ying; Yu, Bin; Zhang, Chun-ping; Zheng, Guan-hua; Bai, Lan; Zhang, Pan-pan

2013-06-01

To investigate the occupational health of the workers simultaneously exposed to acrylonitrile, epoxyethane, epoxypropane, and styrene. A questionnaire survey was conducted in 70 front-line workers simultaneously exposed to acrylonitrile, epoxyethane, epoxypropane, and styrene (exposure group) and 50 managers (control group) in a polyether manufacturer; in addition, air monitoring at workplace and occupational health examination were also performed. The obtained data were analyzed. The female workers in exposure group and the spouses of male workers in exposure group had significantly higher spontaneous abortion rates than their counterparts in control group (P polyether-exposed working years had significantly higher mean levels of DNA damage than the control group (P polyether-exposed working years and those with not less than 20 polyether-exposed working years had significantly higher mean micronucleus rates than the control group (P polyether-exposed working years (P > 0.05); the workers with not less than 5 and less than 20 polyether-exposed working years and workers with not less than 20 polyether-exposed working years had significantly higher mean micronucleus rates than those with less than 5 polyether-exposed working years (P polyether manufacturer.

High-k 3D-barium titanate foam/phenolphthalein poly(ether sulfone)/cyanate ester composites with frequency-stable dielectric properties and extremely low dielectric loss under reduced concentration of ceramics

Science.gov (United States)

Zheng, Longhui; Yuan, Li; Guan, Qingbao; Liang, Guozheng; Gu, Aijuan

2018-01-01

Higher dielectric constant, lower dielectric loss and better frequency stability have been the developing trends for high dielectric constant (high-k) materials. Herein, new composites have been developed through building unique structure by using hyperbranched polysiloxane modified 3D-barium titanate foam (BTF) (BTF@HSi) as the functional fillers and phenolphthalein poly(ether sulfone) (cPES)/cyanate ester (CE) blend as the resin matrix. For BTF@HSi/cPES/CE composite with 34.1 vol% BTF, its dielectric constant at 100 Hz is as high as 162 and dielectric loss is only 0.007; moreover, the dielectric properties of BTF@HSi/cPES/CE composites exhibit excellent frequency stability. To reveal the mechanism behind these attractive performances of BTF@HSi/cPES/CE composites, three kinds of composites (BTF/CE, BTF/cPES/CE, BTF@HSi/CE) were prepared, their structure and integrated performances were intensively investigated and compared with those of BTF@HSi/cPES/CE composites. Results show that the surface modification of BTF is good for preparing composites with improved thermal stability; while introducing flexible cPES to CE is beneficial to fabricate composites with good quality through effectively blocking cracks caused by the stress concentration, and then endowing the composites with good dielectric properties at reduced concentration of ceramics.

Sequential enzymatic epoxidation involved in polyether lasalocid biosynthesis.

Science.gov (United States)

Minami, Atsushi; Shimaya, Mayu; Suzuki, Gaku; Migita, Akira; Shinde, Sandip S; Sato, Kyohei; Watanabe, Kenji; Tamura, Tomohiro; Oguri, Hiroki; Oikawa, Hideaki

2012-05-02

Enantioselective epoxidation followed by regioselective epoxide opening reaction are the key processes in construction of the polyether skeleton. Recent genetic analysis of ionophore polyether biosynthetic gene clusters suggested that flavin-containing monooxygenases (FMOs) could be involved in the oxidation steps. In vivo and in vitro analyses of Lsd18, an FMO involved in the biosynthesis of polyether lasalocid, using simple olefin or truncated diene of a putative substrate as substrate mimics demonstrated that enantioselective epoxidation affords natural type mono- or bis-epoxide in a stepwise manner. These findings allow us to figure out enzymatic polyether construction in lasalocid biosynthesis. © 2012 American Chemical Society

40 CFR 721.3710 - Polyether modified fatty acids (generic).

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyether modified fatty acids... Specific Chemical Substances § 721.3710 Polyether modified fatty acids (generic). (a) Chemical substance... Polyether modified fatty acids (PMN P-99-0435) is subject to reporting under this section for the...

Polyether complexes of groups 13 and 14.

Science.gov (United States)

Swidan, Ala'aeddeen; Macdonald, Charles L B

2016-07-21

Notable aspects of the chemistry of complexes of polyether ligands including crown ethers, cryptands, glycols, glymes, and related polyether ligands with heavier group 13 and 14 elements are reviewed with a focus on results from 2005 to the present. The majority of reported polyether complexes contain lead(ii) and thallium(i) but recent breakthroughs in regard to the preparation of low oxidation state reagents of the lighter congeners have allowed for the generation of complexes containing indium(i), gallium(i), germanium(ii), and even silicon(ii). The important roles of ligand size, donor types, and counter anions in regard to the chemical properties of the polyether complexes is highlighted. A particular focus on the structural aspects of the numerous coordination complexes provides a rationale for some of the spectacular contributions that such compounds have made to Modern Main Group Chemistry.

Extrusion-mixing compared with hand-mixing of polyether impression materials?

Science.gov (United States)

McMahon, Caroline; Kinsella, Daniel; Fleming, Garry J P

2010-12-01

The hypotheses tested were two-fold (a) whether altering the base:catalyst ratio influences working time, elastic recovery and strain in compression properties of a hand-mixed polyether impression material and (b) whether an extrusion-mixed polyether impression material would have a significant advantage over a hand-mixed polyether impression material mixed to the optimum base:catalyst ratio. The polyether was hand-mixed at the optimum (manufacturers recommended) base:catalyst ratios (7:1) and further groups were made by increasing or decreasing the catalyst length by 25%. Additionally specimens were also made from an extrusion-mixed polyether impression material and compared with the optimum hand-mixed base:catalyst ratio. A penetrometer assembly was used to measure the working time (n=5). Five cylindrical specimens for each hand-mixed and extrusion mixed group investigated were employed for elastic recovery and strain in compression testing. Hand-mixing polyether impression materials with 25% more catalyst than that recommended significantly decreased the working time while hand-mixing with 25% less catalyst than that recommended significantly increased the strain in compression. The extrusion-mixed polyether impression material provided similar working time, elastic recovery and strain in compression to the hand-mixed polyether mixed at the optimum base:catalyst ratio.

A rare allergy to a polyether dental impression material.

Science.gov (United States)

Mittermüller, Pauline; Szeimies, Rolf-Markus; Landthaler, Michael; Schmalz, Gottfried

2012-08-01

Polyether impression materials have been used in dentistry for more than 40 years. Allergic reactions to these materials such as reported in the 1970s ceased after replacement of a catalyst. Very recently, however, patients have started to report symptoms that suggest a new allergic reaction from polyether impression materials. Here, we report on the results of allergy testing with polyether impression materials as well as with its components. Eight patients with clinical symptoms of a contact allergy (swelling, redness or blisters) after exposure to a polyether impression material were subjected to patch tests, two of them additionally to a prick test. A further patient with atypical symptoms of an allergy (nausea and vomiting after contact with a polyether impression material in the oral cavity) but with a history of other allergic reaction was also patch tested. The prick tests showed no immediate reactions in the two patients tested. In the patch tests, all eight patients with typical clinical symptoms showed positive reactions to the mixed polyether impression materials, to the base paste or to a base paste component. The patient with the atypical clinical symptoms did not show any positive patch test reactions. Polyether impression materials may evoke type IV allergic reactions. The causative agent was a component of the base paste. In consideration of the widespread use of this impression material (millions of applications per year) and in comparison to the number of adverse reactions from other dental materials, the number of such allergic reactions is very low. In very scarce cases, positive allergic reactions to polyether impression materials are possible.

Structures and properties of naturally occurring polyether antibiotics.

Science.gov (United States)

Rutkowski, Jacek; Brzezinski, Bogumil

2013-01-01

Polyether ionophores represent a large group of natural, biologically active substances produced by Streptomyces spp. They are lipid soluble and able to transport metal cations across cell membranes. Several of polyether ionophores are widely used as growth promoters in veterinary. Polyether antibiotics show a broad spectrum of bioactivity ranging from antibacterial, antifungal, antiparasitic, antiviral, and tumour cell cytotoxicity. Recently, it has been shown that some of these compounds are able to selectively kill cancer stem cells and multidrug-resistant cancer cells. Thus, they are recognized as new potential anticancer drugs. The biological activity of polyether ionophores is strictly connected with their molecular structure; therefore, the purpose of this paper is to present an overview of their formula, molecular structure, and properties.

Polyether ionophores-promising bioactive molecules for cancer therapy.

Science.gov (United States)

Huczyński, Adam

2012-12-01

The natural polyether ionophore antibiotics might be important chemotherapeutic agents for the treatment of cancer. In this article, the pharmacology and anticancer activity of the polyether ionophores undergoing pre-clinical evaluation are reviewed. Most of polyether ionophores have shown potent activity against the proliferation of various cancer cells, including those that display multidrug resistance (MDR) and cancer stem cells (CSC). The mechanism underlying the anticancer activity of ionophore agents can be related to their ability to form complexes with metal cations and transport them across cellular and subcellular membranes. Increasing evidence shows that the anticancer activity of polyether ionophores may be a consequence of the induction of apoptosis leading to apoptotic cell death, arresting cell cycle progression, induction of the cell oxidative stress, loss of mitochondrial membrane potential, reversion of MDR, synergistic anticancer effect with other anticancer drugs, etc. Continued investigation of the mechanisms of action and development of new polyether ionophores and their derivatives may provide more effective therapeutic drugs for cancer treatments. Copyright © 2012 Elsevier Ltd. All rights reserved.

Study of distillation and degradation of perfluoro polyether

International Nuclear Information System (INIS)

Lopergolo, Lilian Cristine

1997-01-01

Perfluoro-polyethers, PFPE, were first synthesised by Sianesi and collaborators giving rise to a new lubricant oils and greases classes with several applications. Perfluoro polyethers have excellent properties, for instance: high chemical stability and thermal stability, high density, high radiation resistance and excellent lubricating properties. FOMBLIN-Y oil is one of the perfluoro polyethers used as a lubricant in vacuum systems applied in the UF 6 enrichment installations. Due to its excellent properties and for its applications in the nuclear field, IPEN-CNEN/S P had the interest to dominate its production technology with the aim to substitute the commercial FOMBLIN-Y oil used in the national consumption. The FOMBLIN-Y oil synthesis method, adopted in IPEN-CNEN/S P, made by the photooxidation of the hexa fluoro propylene. In this work we study the fraction separation of the national available production with restricted an increased molecular weights which was obtained by fraction distillation in a vacuum according to the ASTM D-1160 norm. We also study the catalytic effect of metals on the thermal stability of perfluoro polyethers. The inertness of perfluoro polyethers at temperatures higher than 300 deg C is strongly affected by presence of some metals. Al and Ti alloys cause fluid degradation at 250 deg C. This degradation is very important because it has a yield increase of the perfluoro polyethers production. (author)

Synthesis of novel disulfide and sulfone hybrid scaffolds as potent β-glucuronidase inhibitor.

Science.gov (United States)

Taha, Muhammad; Ismail, Nor Hadiani; Imran, Syahrul; Wadood, Abdul; Rahim, Fazal; Al Muqarrabin, Laode Muhammad Ramadhan; Zaki, Hamizah Mohd; Ahmat, Norizan; Nasir, Abdul; Khan, Fahad

2016-10-01

Novel series of disulfide and sulfone hybrid analogs (1-20) were synthesized and characterized through EI-MS and (1)H NMR and evaluated for β-glucuronidase inhibitory potential. All synthesized analogs except 13 and 15 showed excellent β-glucuronidase inhibitory potential with IC50 value ranging in between 2.20-88.16μM as compared to standard d-saccharic acid 1,4 lactone (48.4±1.25μM). Analogs 19, 16, 4, 1, 17, 6, 10, 3, 18, 2, 11, 14 and 5 showed many fold potent activity against β-glucuronidase inhibitor. Structure activity relationship showed that substitution of electron withdrawing groups at ortho as well as para position on phenyl ring increase potency. Electron withdrawing groups at meta position on phenyl ring showed slightly low potency as compared to ortho and para position. The binding interactions were confirmed through molecular docking studies. Copyright © 2016 Elsevier Inc. All rights reserved.

Preparation of graphite intercalation compounds containing oligo and polyethers

Science.gov (United States)

Zhang, Hanyang; Lerner, Michael M.

2016-02-01

Layered host-polymer nanocomposites comprising polymeric guests between inorganic sheets have been prepared with many inorganic hosts, but there is limited evidence for the incorporation of polymeric guests into graphite. Here we report for the first time the preparation, and structural and compositional characterization of graphite intercalation compounds (GICs) containing polyether bilayers. The new GICs are obtained by either (1) reductive intercalation of graphite with an alkali metal in the presence of an oligo or polyether and an electrocatalyst, or (2) co-intercalate exchange of an amine for an oligo or polyether in a donor-type GIC. Structural characterization of products using powder X-ray diffraction, Raman spectroscopy, and thermal analyses supports the formation of well-ordered, first-stage GICs containing alkali metal cations and oligo or polyether bilayers between reduced graphene sheets.Layered host-polymer nanocomposites comprising polymeric guests between inorganic sheets have been prepared with many inorganic hosts, but there is limited evidence for the incorporation of polymeric guests into graphite. Here we report for the first time the preparation, and structural and compositional characterization of graphite intercalation compounds (GICs) containing polyether bilayers. The new GICs are obtained by either (1) reductive intercalation of graphite with an alkali metal in the presence of an oligo or polyether and an electrocatalyst, or (2) co-intercalate exchange of an amine for an oligo or polyether in a donor-type GIC. Structural characterization of products using powder X-ray diffraction, Raman spectroscopy, and thermal analyses supports the formation of well-ordered, first-stage GICs containing alkali metal cations and oligo or polyether bilayers between reduced graphene sheets. Electronic supplementary information (ESI) available: Domain size, additional Raman spectra info, compositional calculation, and packing fractions. See DOI: 10.1039/c5

Ionic conduction in polyether-based lithium arylfluorosulfonimide ionic melt electrolytes

International Nuclear Information System (INIS)

Herath, Mahesha B.; Creager, Stephen E.; Rajagopal, Rama V.; Geiculescu, Olt E.; DesMarteau, Darryl D.

2009-01-01

We report synthesis, characterization and ion transport in polyether-based ionic melt electrolytes consisting of Li salts of low-basicity anions covalently attached to polyether oligomers. Purity of the materials was investigated by HPLC analysis and electrospray ionization mass spectrometry. The highest ionic conductivity of 7.1 x 10 -6 S/cm at 30 deg. C was obtained for the sample consisting of a lithium salt of an arylfluorosulfonimide anion attached to a polyether oligomer with an ethyleneoxide (EO) to lithium ratio of 12. The conductivity order of various ionic melts having different polyether chain lengths suggests that at higher EO:Li ratios the conductivity of the electrolytes at room temperature is determined in part by the amount of crystallization of the polyether portion of the ionic melt.

Epoxide hydrolase Lsd19 for polyether formation in the biosynthesis of lasalocid A: direct experimental evidence on polyene-polyepoxide hypothesis in polyether biosynthesis.

Science.gov (United States)

Shichijo, Yoshihiro; Migita, Akira; Oguri, Hiroki; Watanabe, Mami; Tokiwano, Tetsuo; Watanabe, Kenji; Oikawa, Hideaki

2008-09-17

Polyether metabolites are an important class of natural products. Although their biosynthesis, especially construction of polyether skeletons, attracted organic chemists for many years, no experimental data on the enzymatic polyether formation has been obtained. In this study, a putative epoxide hydrolase gene lsd19 found on the biosynthetic gene cluster of an ionophore polyether lasalocid was cloned and successfully overexpressed in Escherichia coli. Using the purified Lsd19, a proposed substrate, bisepoxyprelasalocid, and its synthesized analogue were successfully converted into lasalocid A and its derivative via a 6-endo-tet cyclization mode. On the other hand, treatment of the bisepoxide with trichloroacetic acid gave isolasalocid A via a 5-exo-tet cyclization mode. Therefore, the enzymatic conversion observed in this study unambiguously showed that the bisepoxyprelasalocid is an intermediate of the lasalocid biosynthesis and that Lsd19 catalyzes the sequential cyclic ether formations involving an energetically disfavored 6-endo-tet cyclization. This is the first example of the enzymatic epoxide-opening reactions leading to a polyether natural product.

Synthesis and characterization of sulfonated cardo poly(arylene ether sulfone)s for fuel cell proton exchange membrane application

Energy Technology Data Exchange (ETDEWEB)

Islam, M.M.; Jang, H.H.; Lim, Y.D.; Seo, D.W.; Kim, W.G. [Department of Applied Chemistry, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kim, T.H.; Hong, Y.T. [Energy Material Research Center, Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of); Kim, D.M. [Material Engineering and Science, Hongik Univ, Jochiwon-eup, Yeongi-gun, Chungnam (Korea, Republic of)

2012-12-15

Sulfonated cardo poly(arylene ether sulfone)s (SPPA-PES) with various degrees of sulfonation (DS) were prepared by post-sulfonation of synthesized phenolphthalein anilide (PPA; N-phenyl-3,3'-bis(4-hydroxyphenyl)-1-isobenzopyrolidone) poly(arylene ether sulfone)s (PPA-PES) by using concentrated sulfuric acid. PPA-PES copolymers were synthesized by direct polycondensation of PPA with bis-(4-fluorophenyl)-sulfone and 4,4'-sulfonyldiphenol. The DS was varied with different mole ratios of PPA (24, 30, 40, 50 mol.%) in the polymer. The structure of the resulting SPPA-PES copolymers and the different contents of the sulfonated unit were studied by Fourier transform infrared (FT-IR) spectroscopy, {sup 1}H NMR spectroscopy, and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity of SPPA-PES were evaluated according to the increase of DS. The water uptake (WU) of the resulting SPPA-PES membranes was in the range of 20-72%, compared with 28% for Nafion 211 registered. The SPPA-PES membranes showed proton conductivities of 23-82 mS cm{sup -1}, compared with 194 mS cm{sup -1} for Nafion 211 registered, under 100% relative humidity (RH) at 80 C. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Nanostructured Polyelectrolytes Based on SPEEK/TiO2 for Direct Ethanol Fuel Cells (DEFCs)

OpenAIRE

Dutra Filho, José Carlos; Santos, Tamirys Rodrigues dos; Gomes, Aílton de Souza

2014-01-01

Proton-conducting hybrid membranes consisting of poly(ether ether ketone) sulfonated (SPEEK) and titanium oxide (TiO2) were prepared using the sol-gel technique for application in direct ethanol fuel cells. The effect from TiO2 incorporation on membrane properties such as ethanol uptake, pervaporation and proton conductivity was investigated. The uptake and permeated flux decreased with increasing content of TiO2. The ethanol permeability was about one order of magnitude smaller than Nafion® ...

Novel acid-base hybrid membrane based on amine-functionalized reduced graphene oxide and sulfonated polyimide for vanadium redox flow battery

International Nuclear Information System (INIS)

Cao, Li; Sun, Qingqing; Gao, Yahui; Liu, Luntao; Shi, Haifeng

2015-01-01

A series of novel acid-base hybrid membranes (SPI/PEI-rGO) based on sulfonated polyimide (SPI) with polyethyleneimine-functionalized reduced graphene oxide (PEI-rGO) are prepared by a solution-casting method for vanadium redox flow battery (VRB). FT-IR and XPS results prove the successful fabrication of PEI-rGO and SPI/PEI-rGO hybrid membranes, which show a dense and homogeneous structure observed by SEM. The physicochemical properties such as water uptake, swelling ratio, ion exchange capacity, proton conductivity and vanadium ion permeability are well controlled by the incorporated PEI-rGO fillers. The interfacial-formed acid-base pairs between PEI-rGO and SPI matrix effectively reduce the swelling ratio and vanadium ion permeability, increasing the stability performance of the hybrid membranes. SPI/PEI-rGO-2 hybrid membrane exhibits a higher coulombic efficiency (CE, 95%) and energy efficiency (EE, 75.6%) at 40 mA cm −2 , as compared with Nafion 117 membrane (CE, 91% and EE, 66.8%). The self-discharge time of the VRB with SPI/PEI-rGO-2 hybrid membrane (80 h) is longer than that of Nafion 117 membrane (26 h), demonstrating the excellent blocking ability for vanadium ion. After 100 charge-discharge cycles, SPI/PEI-rGO-2 membrane exhibits the good stability under strong oxidizing and acid condition, proving that SPI/PEI-rGO acid-base hybrid membranes could be used as the promising candidates for VRB applications

Handling of Polyvinylsiloxane Versus Polyether for Implant Impressions.

Science.gov (United States)

Farhan, Daniel; Lauer, Wiebke; Heydecke, Guido; Aarabi, Ghazal; Reissmann, Daniel R

2016-01-01

This study compared polyvinylsiloxane with polyether in handling dental impressions. Each participant (N = 39) made four impressions, each a combination of pickup and reseating techniques with polyether or polyvinylsiloxane, of one implant cast representing a specific clinical situation (tooth gaps, limited residual dentition, or edentulous jaw). Handling of impressions was subsequently rated by using a 12-item questionnaire with 100-mm visual analog scales. While mean satisfaction scores were higher for polyvinylsiloxane than for polyether (69.5/63.0, P < .001), differences among subgroups were statistically significant only for pickup technique, limited residual dentition, and edentulous jaw. Implant impressions made with polyvinylsiloxane using a pickup technique seem to be the best option for most clinical situations.

Genetic screening strategy for rapid access to polyether ionophore producers and products in actinomycetes.

Science.gov (United States)

Wang, Hao; Liu, Ning; Xi, Lijun; Rong, Xiaoying; Ruan, Jisheng; Huang, Ying

2011-05-01

Polyether ionophores are a unique class of polyketides with broad-spectrum activity and outstanding potency for the control of drug-resistant bacteria and parasites, and they are produced exclusively by actinomycetes. A special epoxidase gene encoding a critical tailoring enzyme involved in the biosynthesis of these compounds has been found in all five of the complete gene clusters of polyether ionophores published so far. To detect potential producer strains of these antibiotics, a pair of degenerate primers was designed according to the conserved regions of the five known polyether epoxidases. A total of 44 putative polyether epoxidase gene-positive strains were obtained by the PCR-based screening of 1,068 actinomycetes isolated from eight different habitats and 236 reference strains encompassing eight major families of Actinomycetales. The isolates spanned a wide taxonomic diversity based on 16S rRNA gene analysis, and actinomycetes isolated from acidic soils seemed to be a promising source of polyether ionophores. Four genera were detected to contain putative polyether epoxidases, including Micromonospora, which has not previously been reported to produce polyether ionophores. The designed primers also detected putative epoxidase genes from diverse known producer strains that produce polyether ionophores unrelated to the five published gene clusters. Moreover, phylogenetic and chemical analyses showed a strong correlation between the sequence of polyether epoxidases and the structure of encoded polyethers. Thirteen positive isolates were proven to be polyether ionophore producers as expected, and two new analogues were found. These results demonstrate the feasibility of using this epoxidase gene screening strategy to aid the rapid identification of known products and the discovery of unknown polyethers in actinomycetes.

Synthesis and properties of sulfonated poly(phenylene sulfone)s without ether linkage by Diels–Alder reaction for PEMFC application

International Nuclear Information System (INIS)

Lim, Youngdon; Lee, Hyunchul; Lee, Soonho; Jang, Hohyoun; Hossain, Md. Awlad; Cho, Younggil; Kim, Taeho; Hong, Youngtaik; Kim, Whangi

2014-01-01

A new sulfonated poly(phenylene sulfone) polymer (SPPS) was synthesized by Diels-Alder polymerization from 1,4-bis(2,4,5-triphenylcyclopentadienone)benzene (BTPCPB) and 4,4′-diethynylphenylsulfone, and followed by sulfonation reaction with chlorosulfuric acid. A series of sulfonated poly(phenylene sulfone)s (SPPS) with different degrees of sulfonation was prepared in a controllable manner with chlorosulfuric acid. These polymers showed good solubility in aprotic polar solvents, dimethyl acetamide (DMAC) and dimethyl sulfoxide (DMSO). Three different polymer membranes were studied by 1 H NMR spectroscopy, and thermogravimetric analysis (TGA). The ion exchange capacity (IEC) and proton conductivity of SPPS were evaluated according to the degrees of sulfonation. The water uptake (WU) of the synthesized SPPS membranes ranged from 38%∼75%, compared with 32% for Nafion 211 ® at 80 °C. The SPPS membranes exhibited proton conductivities (at 80 °C under 90% RH) of 110.2 mS/cm compared with 102.7 mS/cm for Nafion 211 ® . Power density was performed by single cell and showed similar to Nafion value

Separation of alkali metals by extraction chromatography using polyethers

International Nuclear Information System (INIS)

Smulek, W.; Lada, W.

1977-01-01

Separation of alkali metals by means of acyclic polyether 1,13 bis(8-chinolinyl)1, 4, 7, 10, 13 pentaoxatridecane (CPOD) and cyclic polyether dibenzo-18-crown-6 (DBC) using extraction chromatography is described. Solutions of NaSCN were used as eluting agents. The separation ability of the polyether columns strongly depends on pH and temperature. The following radioisotopes were used in the experiments: Na-22, K-42, Rb-86 and Cs-137. The radionuclide purity of the tracers was examined by γ-ray spectrometry using a Ge(Li) detector and a multichannel γ-ray spectrometer. (T.I.)

Luminescent hybrid lanthanide sulfates and lanthanide sulfonate-carboxylates with 1,10-phenanthroline involving in-situ oxidation of 2-mercaptonbenzoic acid

Science.gov (United States)

Zhong, Jie-Cen; Wan, Fang; Sun, Yan-Qiong; Chen, Yi-Ping

2015-01-01

A series of lanthanide sulfates and lanthanide sulfonate-carboxylates, [Ln2(phen)2(SO4)3(H2O)2]n (I:Ln=Nd(1a), Sm(1b), Eu(1c), phen=1,10-phenanthroline) and [Ln(phen)(2-SBA)(BZA)]n (II: Ln=Sm(2a), Eu(2b), Dy(2c), 2-SBA=2-sulfobenzoate, BZA=benzoate) have been hydrothermally synthesized from lanthanide oxide, 2-mercaptonbenzoic acid with phen as auxiliary ligand and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, TG analyses and luminescence spectroscopy. Interestingly, SO4 2 - anions in I came from the in situ deep oxidation of thiol groups of 2-mercaptonbenzoic acid while 2-sulfobenzoate and benzoate ligands in II from the middle oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. Compounds I are organic-inorganic hybrid lanthanide sulfates, which have rare one-dimensional column-like structures. Complexes II are binuclear lanthanide sulfonate-carboxylates with 2-sulfobenzoate and benzoate as bridges and 1,10-phenanthroline as terminal. Photoluminescence studies reveal that complexes I and II exhibit strong lanthanide characteristic emission bands in the solid state at room temperature.

Magnetic solid-phase extraction based on carbon nanotubes for the determination of polyether antibiotic and s-triazine drug residues in animal food with LC-MS/MS.

Science.gov (United States)

Liu, Xiaoxing; Xie, Shuyu; Ni, Tengteng; Chen, Dongmei; Wang, Xu; Pan, Yuanhu; Wang, Yulian; Huang, Lingli; Cheng, Guyue; Qu, Wei; Liu, Zhenli; Tao, Yanfei; Yuan, Zonghui

2017-06-01

Carbon nanotubes-magnetic nanoparticles, comprising ferroferric oxide nanoparticles and carbon nanotubes, were prepared through a simple one-step synthesis method and subsequently applied to magnetic solid-phase extraction for the determination of polyether antibiotic and s-triazine drug residues in animal food coupled with liquid chromatography with tandem mass spectrometry. The nanocomposites were characterized by transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometry. The components within the nanocomposites endowed the material with high extraction performance and manipulative convenience. Compared with carbon nanotubes, the as-prepared carbon nanotubes-magnetic nanoparticles showed better extraction and separation efficiencies for polyether antibiotics and s-triazine drugs thanks to the contribution of the iron-containing magnetic nanoparticles. Various experimental parameters affecting the extraction efficiency had been investigated in detail. Under the optimal conditions, the good linearity ranging from 1 to 200 μg/kg for diclazuril, toltrazuril, toltrazuril sulfone, lasalocid, monensin, salinomycin, narasin, nanchangmycin, and maduramicin, low limits of detection ranging from 1 to 5 μg/kg, and satisfactory spiked recoveries (77.1-91.2%, with the inter relative standard deviation values from 4.0 to 12.2%) were shown. It was confirmed that this novel method was an efficient pretreatment and enrichment procedure and could be successfully applied for extraction and determination of polyether and s-triazine drug residues in complex matrices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Novel proton exchange membranes based on structure-optimized poly(ether ether ketone ketone)s and nanocrystalline cellulose

Science.gov (United States)

Ni, Chuangjiang; Wei, Yingcong; Zhao, Qi; Liu, Baijun; Sun, Zhaoyan; Gu, Yan; Zhang, Mingyao; Hu, Wei

2018-03-01

Two sulfonated fluorenyl-containing poly(ether ether ketone ketone)s (SFPEEKKs) were synthesized as the matrix of composite proton exchange membranes by directly sulfonating copolymer precursors comprising non-sulfonatable fluorinated segments and sulfonatable fluorenyl-containing segments. Surface-modified nanocrystalline cellulose (NCC) was produced as the "performance-enhancing" filler by treating the microcrystalline cellulose with acid. Two families of SFPEEKK/NCC nanocomposite membranes with various NCC contents were prepared via a solution-casting procedure. Results revealed that the insertion of NCC at a suitable ratio could greatly enhance the proton conductivity of the pristine membranes. For example, the proton conductivity of SFPEEKK-60/NCC-4 (SFPEEKK with 60% fluorenyl segments in the repeating unit, and inserted with 4% NCC) composite membrane was as high as 0.245 S cm-1 at 90 °C, which was 61.2% higher than that of the corresponding pure SFPEEKK-60 membrane. This effect could be attributed to the formation of hydrogen bond networks and proton conduction paths through the interaction between -SO3H/-OH groups on the surface of NCC particles and -SO3H groups on the SFPEEKK backbones. Furthermore, the chemically modified NCC filler and the optimized chemical structure of the SFPEEKK matrix also provided good dimensional stability and mechanical properties of the obtained nanocomposites. In conclusion, these novel nanocomposites can be promising proton exchange membranes for fuel cells at moderate temperatures.

Comparison of Properties among Dendritic and Hyperbranched Poly(ether ether ketones and Linear Poly(ether ketones

Directory of Open Access Journals (Sweden)

Atsushi Morikawa

2016-02-01

Full Text Available Poly(ether ether ketone dendrimers and hyperbranched polymers were prepared from 3,5-dimethoxy-4′-(4-fluorobenzoyldiphenyl ether and 3,5-dihydroxy-4′-(4-fluorobenzoyldiphenyl ether through aromatic nucleophilic substitution reactions. 1-(tert-Butyldimethylsiloxy-3,5-bis(4-fluorobenzoylbenzene was polycondensed with bisphenols, followed by cleavage of the protective group to form linear poly(ether ketones having the same hydroxyl groups in the side chains as the chain ends of the dendrimer and hyperbranched polymers. Their properties, such as solubilities, reduced viscosities, and thermal properties, were compared with one another. Similar comparisons were also carried out among the corresponding methoxy group polymers, and the size of the molecules was shown to affect the properties.

Reactive phase inversion for manufacture of asymmetric poly (ether imide sulfone) membranes

KAUST Repository

Jalal, Taghreed; Charry Prada, Iran David; Tayouo Djinsu, Russell; Giannelis, Emmanuel P.; Nunes, Suzana Pereira

2014-01-01

Poly (ether imide sulfone) membranes were manufactured by combining phase inversion and functionalization reaction between epoxy groups and amine modified polyether oligomers (Jeffamine) or TiO2 nanoparticles. Polysilsesquioxanes containing epoxy functionalities were in-situ grown in the casting solution and made available for further reaction with amines in the coagulation/annealing baths. The membranes were characterized by field emission scanning electron microscopy, porosimetry and water flux measurements. Water permeances up to 1500 l m-2 h-1 bar-1 were obtained with sharp pore size distribution and a pore diameter peak at 66 nm, confirmed by porosimetry, which allowed 99.2% rejection of γ-globulin. Water flux recovery of 77.5% was achieved after filtration with proteins. The membranes were stable in 50:50 dimethylformamide/water, 50:50 N-methyl pyrrolidone/water and 100% tetrahydrofuran. The possibility of using similar concept for homogeneous and stable attachment of nanoparticles on the membrane surface was demonstrated.

Reactive phase inversion for manufacture of asymmetric poly (ether imide sulfone) membranes

KAUST Repository

Jalal, Taghreed

2014-12-01

Poly (ether imide sulfone) membranes were manufactured by combining phase inversion and functionalization reaction between epoxy groups and amine modified polyether oligomers (Jeffamine) or TiO2 nanoparticles. Polysilsesquioxanes containing epoxy functionalities were in-situ grown in the casting solution and made available for further reaction with amines in the coagulation/annealing baths. The membranes were characterized by field emission scanning electron microscopy, porosimetry and water flux measurements. Water permeances up to 1500 l m-2 h-1 bar-1 were obtained with sharp pore size distribution and a pore diameter peak at 66 nm, confirmed by porosimetry, which allowed 99.2% rejection of γ-globulin. Water flux recovery of 77.5% was achieved after filtration with proteins. The membranes were stable in 50:50 dimethylformamide/water, 50:50 N-methyl pyrrolidone/water and 100% tetrahydrofuran. The possibility of using similar concept for homogeneous and stable attachment of nanoparticles on the membrane surface was demonstrated.

The effect of polyether functional polydimethylsiloxane on surface and thermal properties of waterborne polyurethane

Science.gov (United States)

Zheng, Guikai; Lu, Ming; Rui, Xiaoping

2017-03-01

Waterborne polyurethanes (WPU) modified with polyether functional polydimethylsiloxane (PDMS) were synthesized by pre-polymerization method using isophorone diisocyanate (IPDI) and 1,4-butanediol (BDO) as hard segments and polybutylene adipate glycol (PBA) and polyether functional PDMS as soft segments. The effect of polyether functional PDMS on phase separation, thermal properties, surface properties including surface composition, morphology and wettability were investigated by FTIR, contact angle measurements, ARXPS, SEM-EDS, AFM, TG and DSC. The results showed that the compatibility between urethane hard segment and PDMS modified with polyether was good, and there was no distinct phase separation in both bulk and surface of WPU films. The degradation temperature and low temperature flexibility increased with increasing amounts of polyether functional PDMS. The enrichment of polyether functional PDMS with low surface energy on the surface imparted excellent hydrophobicity to WPU films.

Genetic Screening Strategy for Rapid Access to Polyether Ionophore Producers and Products in Actinomycetes ▿ †

Science.gov (United States)

Wang, Hao; Liu, Ning; Xi, Lijun; Rong, Xiaoying; Ruan, Jisheng; Huang, Ying

2011-01-01

Polyether ionophores are a unique class of polyketides with broad-spectrum activity and outstanding potency for the control of drug-resistant bacteria and parasites, and they are produced exclusively by actinomycetes. A special epoxidase gene encoding a critical tailoring enzyme involved in the biosynthesis of these compounds has been found in all five of the complete gene clusters of polyether ionophores published so far. To detect potential producer strains of these antibiotics, a pair of degenerate primers was designed according to the conserved regions of the five known polyether epoxidases. A total of 44 putative polyether epoxidase gene-positive strains were obtained by the PCR-based screening of 1,068 actinomycetes isolated from eight different habitats and 236 reference strains encompassing eight major families of Actinomycetales. The isolates spanned a wide taxonomic diversity based on 16S rRNA gene analysis, and actinomycetes isolated from acidic soils seemed to be a promising source of polyether ionophores. Four genera were detected to contain putative polyether epoxidases, including Micromonospora, which has not previously been reported to produce polyether ionophores. The designed primers also detected putative epoxidase genes from diverse known producer strains that produce polyether ionophores unrelated to the five published gene clusters. Moreover, phylogenetic and chemical analyses showed a strong correlation between the sequence of polyether epoxidases and the structure of encoded polyethers. Thirteen positive isolates were proven to be polyether ionophore producers as expected, and two new analogues were found. These results demonstrate the feasibility of using this epoxidase gene screening strategy to aid the rapid identification of known products and the discovery of unknown polyethers in actinomycetes. PMID:21421776

Development of solid electrolytes for water electrolysis at intermediate temperatures. Task 3 report; Annual report

Energy Technology Data Exchange (ETDEWEB)

Linkous, C.A.; Anderson, R.; Kopitzke, R.W.

1995-12-01

This project is an attempt to synthesize and fabricate proton exchange membranes for hydrogen production via water electrolysis that can take advantage of the better kinetic and thermodynamic conditions that exist at higher temperatures. Current PEM technology is limited to the 125--150 C range. Based on previous work evaluating thermohydrolytic stability, some 5 families of polymers were chosen as viable candidates: polyether ketones, polyether sulfones, fluorinated polyimides, polybenzimidazoles, and polyphenyl quinoxalines. Several of these have been converted into ionomers via sulfonation and fashioned into membranes for evaluation. In particular, the sulfonated polyetheretherketone, or SPEEK, was tested for water uptake, thermo-conductimetric analysis, and performance as the solid electrolyte material in an electrolysis cell. Results comparable to commercial perfluorocarbon sulfonates were obtained.

Synthesis of Marine Polycyclic Polyethers via Endo-Selective Epoxide-Opening Cascades

Directory of Open Access Journals (Sweden)

Timothy F. Jamison

2010-03-01

Full Text Available The proposed biosynthetic pathways to ladder polyethers of polyketide origin and oxasqualenoids of terpenoid origin share a dramatic epoxide-opening cascade as a key step. Polycyclic structures generated in these biosynthetic pathways display biological effects ranging from potentially therapeutic properties to extreme lethality. Much of the structural complexity of ladder polyether and oxasqualenoid natural products can be traced to these hypothesized cascades. In this review we summarize how such epoxide-opening cascade reactions have been used in the synthesis of ladder polyethers and oxasqualenoid natural products.

A durable alternative for proton-exchange membranes: sulfonated poly(benzoxazole thioether sulfone)s

Energy Technology Data Exchange (ETDEWEB)

Zhao, Dan [Center for Innovative Fuel Cell and Battery Technologies, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); Lab of PEMFC Key Materials and Technologies, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Liaoning, Dalian 116023 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Li, Jinhuan [Center for Innovative Fuel Cell and Battery Technologies, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Song, Min-Kyu; Liu, Meilin [Center for Innovative Fuel Cell and Battery Technologies, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); Yi, Baolian; Zhang, Huamin [Lab of PEMFC Key Materials and Technologies, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Liaoning, Dalian 116023 (China)

2011-03-18

To develop a durable proton-exchange membrane (PEM) for fuel-cell applications, a series of sulfonated poly(benzoxazole thioether sulfone)s (SPTESBOs) are designed and synthesized, with anticipated good dimensional stability (via acid-base cross linking), improved oxidative stability against free radicals (via incorporation of thioether groups), and enhanced inherent stability (via elimination of unstable end groups) of the backbone. The structures and the degree of sulfonation of the copolymers are characterized using Fourier-transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy ({sup 1}H NMR and {sup 19}F NMR). The electrochemical stabilities of the monomers are examined using cyclic voltammetry in a typical three-electrode cell configuration. The physicochemical properties of the membranes vital to fuel-cell performance are also carefully evaluated under conditions relevant to fuel-cell operation, including chemical and thermal stability, proton conductivity, solubility in different solvents, water uptake, and swelling ratio. The new membranes exhibit low dimensional change at 25 C to 90 C and excellent thermal stability up to 250 C. Upon elimination of unstable end groups, the co-polymers display enhanced chemical resistance and oxidative stability in Fenton's test. Further, the SPTESBO-HFB-60 (HFB-60=hexafluorobenzene, 60 mol% sulfone) membrane displays comparable fuel-cell performance to that of an NRE 212 membrane at 80 C under fully humidified condition, suggesting that the new membranes have the potential to be more durable but less expensive for fuel-cell applications. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Synthesis and properties of amphiphilic hyperbranched polyethers as pigment dispersant

Science.gov (United States)

Xu, Q.; Zhou, Y. J.; Long, S. J.; Liu, Y. G.; Li, J. H.

2018-01-01

Hyperbranched polymers possess prominent properties such as low viscosity, good solubility, high rheological property, environmental non-toxic, and so on, which have potential applications in coatings. In this study, the amphiphilic hyperbranched polyethers (AHPs) consisting of hydrophobic hyperbranched polyethers core and hydrophilic poly (ethylene glycol) arms with different degree of branching (DB) under various reaction temperatures was prepared by the cation ring-opening polymerization. Their structures were characterized by IR, 13CNMR and GPC. Their dispersion properties for pigment particles were investigated. The AHP47 with 0.47 DB was found to have good dispersion properties for Yellow HGR. This work would provide experimental data and theoretical foundation for the application of hyperbranched polyethers in environmental protection coating.

18F fluorination using macrocyclic polyethers

International Nuclear Information System (INIS)

Klatte, B.; Knoechel, A.

The aim of this work is the nucleophilic substitution labelling with 18 F with high selectivity and yield for a short reaction time. Labelling with little or no carrier presumes that 18 F is obtained in anhydrons form. Starting with the production via the nuclear reaction 20 Ne(d,α) 18 F, the 18 F formed is to be continuously converted into an alkali polyether complex whose purpose is to increase the reactivity of the fluoride (compared to the non-complexed anion form), so that nucleophilic substitution reactions can be carried out faster and more carefully. A report is given on the working program and on first results to optimize the carrier-poor synthesis with polyethers as synthesis agent. (RB) [de

Improvement of the fracture toughness matrix cured by electron beam radiation, by incorporation of thermoplastic

International Nuclear Information System (INIS)

Chauray, E.

2003-07-01

The aim of the present study is to improve the fracture toughness of a vinyl-ester matrix cured by electron beam radiation, by incorporation of a thermoplastic polymer. The ultimate plan is to improve the fracture toughness of the composite material made of this reinforced matrix and carbon fibres. The first step deals with the study of an epoxy matrix reinforced by a polyether-sulfone. This well-known material, as it is used in industrial formulation, allowed us to characterize all the parameters needed to obtain a good reinforcement as for instance the morphology, and also to compare two kinds of processes: thermal and electron beam curing. In fact, we are really interested in increasing fracture toughness of a vinyl-ester matrix that is not miscible with polyether-sulfone. So a copolymer which has a similar structure as polyether-sulfone is synthesized in order to obtain a miscible blend. The corresponding material has good fracture toughness, with an increase of 80 % for 15 % addition of thermoplastic. (author)

Design and synthesis of chalcone-based macrocyclic polyethers

Directory of Open Access Journals (Sweden)

Subrata Jana

2015-12-01

Full Text Available A series of chalcone-based macrocyclic ethers have been synthesized. These macrocyclic ethers contain polyether as well as extended conjugation to the benzene ring to function as fluorescent sensor for cations. The modeling studies show that the chalcone part of the receptors remains partially out of plane from the polyether part and the keto moiety of the receptors always directed outwardly in the receptor itself. This may be changed during the recognition of metal ions. The tendency of the fluorophore, to be out of plane, increases with increasing the ring size.

The effect of polyether on the separation of pentlandite and serpentine

Directory of Open Access Journals (Sweden)

Xiaowen Zhou

2015-10-01

Full Text Available The effect of polyether on the separation of pentlandite from serpentine has been studied. In addition to flotation and sedimentation tests, electrophoresis and adsorption tests have been conducted. The flotation and sedimentation results show that serpentine impairs flotation performance of pentlandite, by adhering to the pentlandite particles. Addition of the polyether could promote the dispersion of the mixed sample of pentlandite and serpentine in alkaline conditions and significantly reduce adverse effects of serpentine on the pentlandite flotation. The electrophoresis and adsorption tests show that polyether can selectively adsorb onto pentlandite surface through hydrophobic reaction and remove serpentine slime particles from pentlandite surfaces by steric hindrance effect.

Biodegradation of polyether algal toxins–Isolation of potential marine bacteria

Science.gov (United States)

SHETTY, KATEEL G.; HUNTZICKER, JACQUELINE V.; REIN, KATHLEEN S.; JAYACHANDRAN, KRISH

2012-01-01

Marine algal toxins such as brevetoxins, okadaic acid, yessotoxin, and ciguatoxin are polyether compounds. The fate of polyether toxins in the aqueous phase, particularly bacterial biotransformation of the toxins, is poorly understood. An inexpensive and easily available polyether structural analog salinomycin was used for enrichment and isolation of potential polyether toxin degrading aquatic marine bacteria from Florida bay area, and from red tide endemic sites in the South Florida Gulf coast. Bacterial growth on salinomycin was observed in most of the enrichment cultures from both regions with colony forming units ranging from 0 to 6 × 107 per mL. The salinomycin biodegradation efficiency of bacterial isolates determined using LC-MS ranged from 22% to 94%. Selected bacterial isolates were grown in media with brevetoxin as the sole carbon source to screen for brevetoxin biodegradation capability using ELISA. Out of the two efficient salinomycin biodegrading isolates MB-2 and MB-4, maximum brevetoxin biodegradation efficiency of 45% was observed with MB-4, while MB-2 was unable to biodegrade brevetoxin. Based on 16S rRNA sequence similarity MB-4 was found have a match with Chromohalobacter sp. PMID:20954040

Biodegradation of polyether algal toxins--isolation of potential marine bacteria.

Science.gov (United States)

Shetty, Kateel G; Huntzicker, Jacqueline V; Rein, Kathleen S; Jayachandran, Krish

2010-12-01

Marine algal toxins such as brevetoxins, okadaic acid, yessotoxin, and ciguatoxin are polyether compounds. The fate of polyether toxins in the aqueous phase, particularly bacterial biotransformation of the toxins, is poorly understood. An inexpensive and easily available polyether structural analog salinomycin was used for enrichment and isolation of potential polyether toxin degrading aquatic marine bacteria from Florida bay area, and from red tide endemic sites in the South Florida Gulf coast. Bacterial growth on salinomycin was observed in most of the enrichment cultures from both regions with colony forming units ranging from 0 to 6×10(7) per mL. The salinomycin biodegradation efficiency of bacterial isolates determined using LC-MS ranged from 22% to 94%. Selected bacterial isolates were grown in media with brevetoxin as the sole carbon source to screen for brevetoxin biodegradation capability using ELISA. Out of the two efficient salinomycin biodegrading isolates MB-2 and MB-4, maximum brevetoxin biodegradation efficiency of 45% was observed with MB-4, while MB-2 was unable to biodegrade brevetoxin. Based on 16S rRNA sequence similarity MB-4 was found have a match with Chromohalobacter sp.

40 CFR Table 4 to Subpart Ppp of... - Known Organic HAP From Polyether Polyol Products

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Known Organic HAP From Polyether Polyol... CATEGORIES National Emission Standards for Hazardous Air Pollutant Emissions for Polyether Polyols Production Pt. 63, Subpt. PPP, Table 4 Table 4 to Subpart PPP of Part 63—Known Organic HAP From Polyether Polyol...

Mechanical properties and chemical stability of pivalolactone-based poly(ether ester)s

NARCIS (Netherlands)

Tijsma, E.J.; Tijsma, E.J.; van der Does, L.; Bantjes, A.; Bantjes, A.; Vulic, I.

1994-01-01

The processing, mechanical and chemical properties of poly(ether ester)s, prepared from pivalolactone (PVL), 1,4-butanediol (4G) and dimethyl terephthalate (DMT), were studied. The poly(ether ester)s could easily be processed by injection moulding, owing to their favourable rheological and thermal

Separation of alkali and alkaline earth metals by polyethers using extraction chromatography

International Nuclear Information System (INIS)

Smulek, W.; Lada, W.A.

1979-01-01

The separation of alkali and alkaline earth metals by means of an acyclic polyether, 1,13-bis(8-chinolinyl)-1, 4, 7, 10, 13-pentaoxatridecane (CPOD), and cyclic polyethers, benzo-15-crown-5 (BC), dibenzo-18-crown-6 (DBC) and dicyclohexyl-18-crown-6 (DCHC), using extraction chromatography has been studied. The alkali metals can be effectively separated using SCN - as the accompanying ion. For alkaline earth metals, the best results were obtained with ClO 4 - ions. Different elution sequences for these groups were observed using chloroform and/meen=/ sitylene as diluents for the polyethers. (author)

Synthesis and properties of novel sulfonated poly(arylene ether sulfone) ionomers for vanadium redox flow battery

Energy Technology Data Exchange (ETDEWEB)

Chen, Dongyang; Wang, Shuanjin; Xiao, Min; Meng, Yuezhong [The Key Laboratory of Low-carbon Chemistry and Energy Conservation of Guangdong Province, Institute of Optoelectronic and Functional Composite Materials, Sun Yat-Sen University, Guangzhou 510275 (China)

2010-12-15

Novel sulfonated poly(arylene ether sulfone)s with electron-withdrawing sulfone groups in each repeat unit were synthesized via step polymerization followed by post-sulfonation using chlorosulfonic acid. The sulfonation degree can be readily controlled by adjusting the feed ratio of the repeat unit of polymers to chlorosulfonic acid. The synthesized polymers are soluble in common aprotic solvents such as dimethyl sulfoxide, N,N'-dimethylacetamide and dimethylformamide, and can be cast into transparent membranes from their solutions. The ion exchange capacity, water uptake, swelling ratio, sulfonation degree, mechanical property, oxidative property, thermal property and proton conductivity were investigated in detail using different methodologies. As an objective to apply these polymers as separators for vanadium redox flow battery, the VO{sup 2+} permeability and cell performance for the single cell were examined and assessed. (author)

Synthesis and properties of novel sulfonated poly(arylene ether sulfone) ionomers for vanadium redox flow battery

Energy Technology Data Exchange (ETDEWEB)

Chen Dongyang [Key Laboratory of Low-carbon Chemistry and Energy Conservation of Guangdong Province, Institute of Optoelectronic and Functional Composite Materials, Sun Yat-Sen University, Guangzhou 510275 (China); Wang Shuanjin, E-mail: wangshj@mail.sysu.edu.c [Key Laboratory of Low-carbon Chemistry and Energy Conservation of Guangdong Province, Institute of Optoelectronic and Functional Composite Materials, Sun Yat-Sen University, Guangzhou 510275 (China); Xiao Min [Key Laboratory of Low-carbon Chemistry and Energy Conservation of Guangdong Province, Institute of Optoelectronic and Functional Composite Materials, Sun Yat-Sen University, Guangzhou 510275 (China); Meng Yuezhong, E-mail: mengyzh@mail.sysu.edu.c [Key Laboratory of Low-carbon Chemistry and Energy Conservation of Guangdong Province, Institute of Optoelectronic and Functional Composite Materials, Sun Yat-Sen University, Guangzhou 510275 (China)

2010-12-15

Novel sulfonated poly(arylene ether sulfone)s with electron-withdrawing sulfone groups in each repeat unit were synthesized via step polymerization followed by post-sulfonation using chlorosulfonic acid. The sulfonation degree can be readily controlled by adjusting the feed ratio of the repeat unit of polymers to chlorosulfonic acid. The synthesized polymers are soluble in common aprotic solvents such as dimethyl sulfoxide, N,N'-dimethylacetamide and dimethylformamide, and can be cast into transparent membranes from their solutions. The ion exchange capacity, water uptake, swelling ratio, sulfonation degree, mechanical property, oxidative property, thermal property and proton conductivity were investigated in detail using different methodologies. As an objective to apply these polymers as separators for vanadium redox flow battery, the VO{sup 2+} permeability and cell performance for the single cell were examined and assessed.

Preparation, characterization and evaluation of proton-conducting hybrid membranes based on sulfonated hydrogenated styrene-butadiene and polysiloxanes for fuel cell applications

Energy Technology Data Exchange (ETDEWEB)

Monroy-Barreto, M.; Aguilar, J.C.; Rodriguez de San Miguel, E.; de Gyves, J. [Departamento de Quimica Analitica, Facultad de Quimica, UNAM, Ciudad Universitaria, 04360 Mexico, D.F. (Mexico); Acosta, J.L.; del Rio, C.; Ojeda, M.C. [Instituto de Ciencia y Tecnologia de Polimeros (CSIC), c/Juan de la Cierva 3, 28006 Madrid (Spain); Munoz, M. [Departament de Quimica Analitica, Facultat de Ciencies, U.A.B., Bellaterra 08193 Barcelona (Spain)

2010-12-15

This paper describes the preparation of proton-conducting hybrid membranes (HMs) obtained by a solvent casting procedure using a solution containing sulfonated hydrogenated styrene-butadiene (HSBS-S) and an inorganic-organic mixture (polysiloxanes) previously prepared by a sol-gel route. HSBS-S copolymers with different sulfonation degrees were obtained and characterized by means of elemental analysis (EA), chemical titration and electrochemical impedance spectroscopy (EIS). HSBS-S with the best properties in terms of proton conductivity and solubility for the casting procedure was selected to prepare the HMs. The solvent casting procedure permitted the two phases to be homogeneously distributed while maintaining a relatively high proton conductivity in the membrane. HMs with different blend ratios were characterized using structural (Fourier transform infrared-attenuated total reflectance (FTIR-ATR), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC)), electrical (EIS), physicochemical (water uptake, ion-exchange capacity) and thermal (TGA-MS) methods. Finally, the optimized HSBS-S membrane and HMs were tested in hydrogen single fuel cells to obtain the polarization and power curves at different cell temperatures and gas pressures. Results indicate that HMs show a considerable improvement in performance compared to the optimized HSBS-S membrane denoting the benefit of incorporating the inorganic-organic network in the hydrogenated styrene-butadiene matrix. A Nafion membrane was used as reference material throughout this work. (author)

In Situ Preparation of Polyether Amine Functionalized MWCNT Nanofiller as Reinforcing Agents

Directory of Open Access Journals (Sweden)

Ayber Yıldrım

2014-01-01

Full Text Available In situ preparation of polyether amine functionalized cross-linked multiwalled carbon nanotube (MWCNT nanofillers may improve the thermal and mechanical properties of the composites in which they are used as reinforcing agents. The reduction and functionalization of MWCNT using ethylenediamine in the presence of polyether amine produced stitched MWCNT's due to the presence of two amine (–NH2 functionalities on both sides of the polymer. Polyether amine was chosen to polymerize the carboxylated MWCNT due to its potential to form bonds with the amino groups and carboxyl groups of MWCNT which produces a resin used as polymeric matrix for nanocomposite materials. The attachment of the polyether amine (Jeffamine groups was verified by TGA, FT-IR, XRD, SEM, and Raman spectroscopy. The temperature at which the curing enthalpy is maximum, observed by DSC, was shifted to higher values by adding functionalized MWCNT. SEM images show the polymer formation between MWCNT sheets.

Extreme ultraviolet (EUV) degradation of poly(olefin sulfone)s: Towards applications as EUV photoresists

International Nuclear Information System (INIS)

Lawrie, Kirsten; Blakey, Idriss; Blinco, James; Gronheid, Roel; Jack, Kevin; Pollentier, Ivan; Leeson, Michael J.; Younkin, Todd R.; Whittaker, Andrew K.

2011-01-01

Poly(olefin sulfone)s, formed by the reaction of sulfur dioxide (SO 2 ) and an olefin, are known to be highly susceptible to degradation by radiation and thus have been identified as candidate materials for chain scission-based extreme ultraviolet lithography (EUVL) resist materials. In order to investigate this further, the synthesis and characterisation of two poly(olefin sulfone)s namely poly(1-pentene sulfone) (PPS) and poly(2-methyl-1-pentene sulfone) (PMPS), was achieved and the two materials were evaluated for possible chain scission EUVL resist applications. It was found that both materials possess high sensitivities to EUV photons; however; the rates of outgassing were extremely high. The only observed degradation products were found to be SO 2 and the respective olefin suggesting that depolymerisation takes place under irradiation in a vacuum environment. In addition to depolymerisation, a concurrent conversion of SO 2 moieties to a sulfide phase was observed using XPS.

Nanostructured Polyelectrolytes Based on SPEEK/TiO2 for Direct Ethanol Fuel Cells (DEFCs

Directory of Open Access Journals (Sweden)

José Carlos Dutra Filho

2014-01-01

Full Text Available Proton-conducting hybrid membranes consisting of poly(ether ether ketone sulfonated (SPEEK and titanium oxide (TiO2 were prepared using the sol-gel technique for application in direct ethanol fuel cells. The effect from TiO2 incorporation on membrane properties such as ethanol uptake, pervaporation and proton conductivity was investigated. The uptake and permeated flux decreased with increasing content of TiO2. The ethanol permeability was about one order of magnitude smaller than Nafion® 117. FTIR spectra indicated that PEEK was sulfonated and the second degradation temperature of SPEEK58 samples confirmed the titanium oxide incorporation. The proton conductivity in ethanol solution was of the order of 10-3 S cm-1 when 4 or 8 wt% TiO2 were added, and generally increased with addition of TiO2.

Sulfonation of PEEK-WC polymer via chloro-sulfonic acid for potential PEM fuel cell applications

Energy Technology Data Exchange (ETDEWEB)

Iulianelli, A.; Clarizia, G.; Gugliuzza, A.; Ebrasu, D.; Basile, A. [Institute on Membrane Technology, ITM-CNR, c/o University of Calabria, Via P. Bucci, Cubo 17/C, 87030 Rende (CS) (Italy); Bevilacqua, A. [Research Centre Italsistemi S.r.l., Via Avogadro, 88900 Crotone (KR) (Italy); Trotta, F. [Department of Organic Chemistry, University of Torino, C.So M. D' Azeglio 48, 10125 Torino (TO) (Italy)

2010-11-15

The preparation and characterization of thin dense sulfonated poly-ether-ether-ketone with cardo group (PEEK-WC) membranes for proton exchange membrane fuel cell (PEMFC) applications are described. The sulfonation of PEEK-WC polymer was realized via chloro-sulfonic acid and different kinds of membrane samples were prepared with a sulfonation degree ranging from 67 to 99%. The degree of sulfonation, homogeneity and thickness significantly affect both the membrane transport properties and the electrochemical performances. The dense character of the membranes was confirmed by SEM analysis. Proton conductivity measurements were carried out in a temperature range from 30 to 80 C and at 100% of relative humidity, reaching 5.40 x 10{sup -3} S/cm{sup -1} as best value at 80 C and with a sulfonation degree (DS) of 99%. At the same conditions, a water uptake of 17% was achieved. DSC and TGA characterizations were used in order to determine the thermal stability of the membranes, confirming a T{sub g} ranging between 206 and 216 C depending on the DS, whereas FT-IR yielded indication about intermolecular interactions and water uptake at various sulfonation degrees. (author)

Propagation/depropagation equilibrium and structural factors in the radiation degradation of poly(olefin sulfone)s

International Nuclear Information System (INIS)

Bowmer, T.N.; O'Donnell, J.H.

1981-01-01

The principal volatile products observed after γ irradiation of nine different poly(olefin sulfone)s in the solid state were the two comonomers, i.e., the respective olefin and sulfur dioxide. An exponential increase in yield, G (volatile products), with increasing irradiation temperature, T/sub irr/, was observed for each copolymer through the ceiling temperature, T/sub c/, for the corresponding propagation/depropagation equilibrium. Thus the G value increased by ca. 3 orders of magnitude from T/sub irr/ = 0.7 T/sub c/ to T/sub irr/ = 1.3 T/sub c/ for all of the poly(olefin sulfone)s. Depropagation sensitivity was considered to be best measured by G(SO 2 ) since radiation induced, cationic homopolymerization of the product olefin occurred to a variable extent. Five of the poly(olefin sulfone)s had similar rates of depropagation at their respective T/sub c's/ but the polysulfones of 1-hexene, cyclohexene and 2-butene showed anomalously high depropagation rates. This may be related to greater steric hinderance to segmental chain mobility in the polysulfones of the 1,2 disubstituted olefins. Poly(1-hexene sulfone) appears to be anomalous, as in other respects

Enhancement of the anticoccidial activity of polyether antibiotics in chickens by tiamulin.

Science.gov (United States)

Meingassner, J G; Schmook, F P; Czok, R; Mieth, H

1979-03-01

The anticoccidial activities of monensin and lasalocid have been studied separately and in combination with tiamulin, a new pleuromutilin derivative. Combinations of constant tiamulin concentration (.0125%) in drinking water with various levels of polyether anticoccidials (6.3 to 125 ppm) in feed and conversely of constant levels of anticoccidials with various concentrations of tiamulin were used. The prophylactic efficacy of these combined treatments in battery raised broiler chickens infected with Eimeria tenella was evaluated. Assessment of the parameters mortality, weight gain, dropping scores, lesion scores, and oocyst output showed that simultaneous application of tiamulin significantly improved the anticoccidial activity of the polyethers. As tiamulin alone is without anticoccidial activity, this phenomenon was considered to result from an interaction between tiamulin and the polyethers leading to a slower metabolic degradation of the latter. Thus tissue levels adequate for maximum anticoccidial activity would be attained with lower polyether dose levels. Experiments using isolated perfused rat liver showed that elimination of monensin was reduced by 60% in the presence of tiamulin.

Systematic Experimental and Computational Investigation of Ion Transport in Novel Polyether Electrolytes

Science.gov (United States)

Pesko, Danielle; Webb, Michael; Jung, Yukyung; Zheng, Qi; Miller, Thomas, III; Coates, Geoffrey; Balsara, Nitash

Polyethers, such as poly(ethylene oxide) (PEO), are considered to be the most promising polymer electrolyte materials due to their high ionic conductivity and electrochemical stability, both essential for battery applications. To gain a fundamental understanding of the transport properties of polyether systems, we design a systematic set of linear PEO-like polymers to explore the effect of adding carbon spacers to the backbone of the chain. Ac impedance spectroscopy is employed to measure the ionic conductivity of polyether/lithium salt electrolytes; the results elucidate tradeoffs between lowering the glass transition temperature and diluting the polar groups on the polymer chain. Molecular-level insight is provided by molecular dynamics simulations of the polyether electrolytes. We define the useful and intuitive metric of ``connectivity'', a parameter calculated from simulations which describes the physical arrangements of solvation sites in a polymer melt. Direct comparison of experiment and theory allows us to determine the relationship between connectivity and conductivity. The comparison provides insight regarding the factors that control conductivity, and highlights considerations that must be taken when designing new ion-conducting polymers.

Epoxide hydrolase-lasalocid a structure provides mechanistic insight into polyether natural product biosynthesis.

Science.gov (United States)

Wong, Fong T; Hotta, Kinya; Chen, Xi; Fang, Minyi; Watanabe, Kenji; Kim, Chu-Young

2015-01-14

Biosynthesis of some polyether natural products involves a kinetically disfavored epoxide-opening cyclic ether formation, a reaction termed anti-Baldwin cyclization. One such example is the biosynthesis of lasalocid A, an ionophore antibiotic polyether. During lasalocid A biosynthesis, an epoxide hydrolase, Lsd19, converts the bisepoxy polyketide intermediate into the tetrahydrofuranyl-tetrahydropyran product. We report the crystal structure of Lsd19 in complex with lasalocid A. The structure unambiguously shows that the C-terminal domain of Lsd19 catalyzes the intriguing anti-Baldwin cyclization. We propose a general mechanism for epoxide selection by ionophore polyether epoxide hydrolases.

Analytical methodology for sulfonated lignins

NARCIS (Netherlands)

Brudin, S.; Schoenmakers, P.

2010-01-01

There is a significant need to characterize and classify lignins and sulfonated lignins. Lignins have so far received a good deal of attention, whereas this is not true for sulfonated lignins. There is a clear demand for a better understanding of sulfonated lignins on a chemical as well as physical

Polymerization of polyethers initiated by irradiation with high power pulsed electron beams

International Nuclear Information System (INIS)

Gerber, V.D.; Tolkachev, V.S.; Chmukh, V.N.

1982-01-01

Air oxygen effect on thin-layer polymerization of polyethers, initiated by irradiation with powerful pulse electron beams is studied using the method of IR-spectrophotometry. The analysis of experimental data has shown that in polyether surface layer polymerization is suppressed by oxygen, concentration of which in the layer remains stable at the expense of diffusion from air during two consequent irradiation pulses

Poly-ethers from Winogradskyella poriferorum: Antifouling potential, time-course study of production and natural abundance

KAUST Repository

Dash, Swagatika

2011-08-01

A sponge-associated bacterium, Winogradskyella poriferorum strain UST030701-295T was cultured up to 100l for extraction of antifouling bioactive compounds. Five poly-ethers were isolated and partially characterized based on nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS); two of them showed inhibitory effects on biofilm formation of marine bacteria and larval settlement of macro-foulers but did not produce any adverse effects on the phenotypes of zebra fish embryos at a concentration of 5μgml -1. The effect of culture duration on the production of the poly-ethers and the bioactivity of the relevant extracts was monitored over a period of 12days. The total crude poly-ether production increased from day 2 to day 5 and the highest bioactivity was observed on day 3. The poly-ethers were found to be localized in the cellular fraction of the extracts, implying their natural occurrence. The potent bioactivity of these poly-ethers together with their high natural abundance in bacteria makes them promising candidates as ingredients in antifouling applications. © 2011 Elsevier Ltd.

Nanoscale Organic−Inorganic Hybrid Lubricants

KAUST Repository

Kim, Daniel; Archer, Lynden A.

2011-01-01

Silica (SiO2) nanoparticles densely grafted with amphiphilic organic chains are used to create a family of organic-inorganic hybrid lubricants. Short sulfonate-functionalized alkylaryl chains covalently tethered to the particles form a dense corona

Enhanced Proton Conductivity of Sulfonated Hybrid Poly(arylene ether ketone) Membranes by Incorporating an Amino-Sulfo Bifunctionalized Metal-Organic Framework for Direct Methanol Fuel Cells.

Science.gov (United States)

Ru, Chunyu; Li, Zhenhua; Zhao, Chengji; Duan, Yuting; Zhuang, Zhuang; Bu, Fanzhe; Na, Hui

2018-03-07

Novel side-chain-type sulfonated poly(arylene ether ketone) (SNF-PAEK) containing naphthalene and fluorine moieties on the main chain was prepared in this work, and a new amino-sulfo-bifunctionalized metal-organic framework (MNS, short for MIL-101-NH 2 -SO 3 H) was synthesized via a hydrothermal technology and postmodification. Then, MNS was incorporated into a SNF-PAEK matrix as an inorganic nanofiller to prepare a series of organic-inorganic hybrid membranes (MNS@SNF-PAEK-XX). The mechanical property, methanol resistance, electrochemistry, and other properties of MNS@SNF-PAEK-XX hybrid membranes were characterized in detail. We found that the mechanical strength and methanol resistances of these hybrid membranes were improved by the formation of an ionic cross-linking structure between -NH 2 of MNS and -SO 3 H on the side chain of SNF-PAEK. Particularly, the proton conductivity of these hybrid membranes increased obviously after the addition of MNS. MNS@SNF-PAEK-3% exhibited the proton conductivity of 0.192 S·cm -1 , which was much higher than those of the pristine membrane (0.145 S·cm -1 ) and recast Nafion (0.134 S·cm -1 ) at 80 °C. This result indicated that bifunctionalized MNS rearranged the microstructure of hybrid membranes, which could accelerate the transfer of protons. The hybrid membrane (MNS@SNF-PAEK-3%) showed a better direct methanol fuel cell performance with a higher peak power density of 125.7 mW/cm 2 at 80 °C and a higher open-circuit voltage (0.839 V) than the pristine membrane.

Study of distillation and degradation of perfluoro polyether; Estudo da destilacao e degradacao do perfluoropolieter

Energy Technology Data Exchange (ETDEWEB)

Lopergolo, Lilian Cristine

1997-07-01

Perfluoro-polyethers, PFPE, were first synthesised by Sianesi and collaborators giving rise to a new lubricant oils and greases classes with several applications. Perfluoro polyethers have excellent properties, for instance: high chemical stability and thermal stability, high density, high radiation resistance and excellent lubricating properties. FOMBLIN-Y oil is one of the perfluoro polyethers used as a lubricant in vacuum systems applied in the UF{sub 6} enrichment installations. Due to its excellent properties and for its applications in the nuclear field, IPEN-CNEN/S P had the interest to dominate its production technology with the aim to substitute the commercial FOMBLIN-Y oil used in the national consumption. The FOMBLIN-Y oil synthesis method, adopted in IPEN-CNEN/S P, made by the photooxidation of the hexa fluoro propylene. In this work we study the fraction separation of the national available production with restricted an increased molecular weights which was obtained by fraction distillation in a vacuum according to the ASTM D-1160 norm. We also study the catalytic effect of metals on the thermal stability of perfluoro polyethers. The inertness of perfluoro polyethers at temperatures higher than 300 deg C is strongly affected by presence of some metals. Al and Ti alloys cause fluid degradation at 250 deg C. This degradation is very important because it has a yield increase of the perfluoro polyethers production. (author)

Safety Assessment of Polyether Lanolins as Used in Cosmetics.

Science.gov (United States)

Becker, Lillian C; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan; Heldreth, Bart

The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) assessed the safety of 39 polyether lanolin ingredients as used in cosmetics. These ingredients function mostly as hair conditioning agents, skin conditioning agent-emollients, and surfactant-emulsifying agents. The Panel reviewed available animal and clinical data, from previous CIR safety assessments of related ingredients and components. The similar structure, properties, functions, and uses of these ingredients enabled grouping them and using the available toxicological data to assess the safety of the entire group. The Panel concluded that these polyether lanolin ingredients are safe in the practices of use and concentration as given in this safety assessment.

Polyether ionophores: broad-spectrum and promising biologically active molecules for the control of drug-resistant bacteria and parasites.

Science.gov (United States)

Kevin Ii, Dion A; Meujo, Damaris Af; Hamann, Mark T

2009-02-01

As multidrug-resistant (MDR) pathogens continue to emerge, there is a substantial amount of pressure to identify new drug candidates. Carboxyl polyethers, also referred to as polyether antibiotics, are a unique class of compounds with outstanding potency against a variety of critical infectious disease targets including protozoa, bacteria and viruses. The characteristics of these molecules that are of key interest are their selectivity and high potency against several MDR etiological agents. Although many studies have been published about carboxyl polyether antibiotics, there are no recent reviews of this class of drugs. The purpose of this review is to provide the reader with an overview of the spectrum of activity of polyether antibiotics, their mechanism of action, toxicity and potential as drug candidates to combat drug-resistant infectious diseases. Polyether ionophores show a high degree of promise for the potential control of drug-resistant bacterial and parasitic infections. Despite the long history of use of this class of drugs, very limited medicinal chemistry and drug optimization studies have been reported, thus leaving the door open to these opportunities in the future. Scifinder and PubMed were the main search engines used to locate articles relevant to the topic presented in the present review. Keywords used in our search were specific names of each of the 88 compounds presented in the review as well as more general terms such as polyethers, ionophores, carboxylic polyethers and polyether antibiotics.

Partially fluorinated aarylene polyethers and their ternary blends with PBI and H3PO4

DEFF Research Database (Denmark)

Li, Qingfeng; Jensen, Jens Oluf; Pan, Chao

2008-01-01

Ternary blend membranes based on sulphonated partially fluorinated arylene polyether, polybenzimidazole (PBI) and phosphoric acid were prepared and characterised as electrolyte for high temperature proton exchange membrane fuel cells. Partially fluorinated arylene polyether was first prepared from...

Photodegradation of poly(ether sulphone). Part 2

DEFF Research Database (Denmark)

Norrman, K.; Krebs, Frederik C

2004-01-01

The photodegradation of poly(ether sulphone) (PES) was investigated systematically by time-of-flight SIMS (ToF-SIMS) and x-ray photoelectron spectroscopy (XPS). The effect of varying the irradiation dose, wavelength and the atmosphere was studied along with mechanistic photooxidation studies using...

Temporal polyethism and worker specialization in the wasp, Vespula germanica.

Science.gov (United States)

Hurd, Christine R; Jeanne, Robert L; Nordheim, Erik V

2007-01-01

Temporal polyethism is a common mechanism of worker specialization observed in social insect species with large colony sizes, Vespula wasp colonies consist of thousands of monomorphic workers, yet studies based on small cohorts of workers report that temporal polyethism is either weak or completely absent in different Vespula species. Concerned that the small sample size of these studies precluded detection of temporal polyethism, several hundred, known-age Vespula germanica (F.) (Hymenoptera: Vespidae) workers were studied. High variability was found in the sequence and diversity of tasks workers perform, suggesting that V. germanica colonies exhibit weak temporal polyethism. The most common order in which tasks were taken up was 1) nest work, 2) pulp foraging, 3) carbohydrate foraging, and 4) protein foraging. However, only 61% of the wasps performed more than two of the tasks during their lives. Thorax size had a significant negative effect on the age at first foraging, but the magnitude of the effect was small. The daily ratio of task generalists to specialists was relatively constant despite the high turnover of workers, growth of the colony, and the colony's transition from rearing worker larvae to rearing reproductives. Over the course of their lives, 43% of the workers averaged more than one kind of task performed per day. Life history traits are identified that may explain why vespines with large colonies use a generalist strategy of labor division rather than the specialist strategy observed in honey bees (Apis mellifera) and large colonies of wasps (Polybia occidentalis).

Sulfonation of vulcanized ethylene-propylene-diene terpolymer membranes

International Nuclear Information System (INIS)

Barroso-Bujans, F.; Verdejo, R.; Lozano, A.; Fierro, J.L.G.; Lopez-Manchado, M.A.

2008-01-01

In the present work, sulfonation of previously vulcanized ethylene propylene diene terpolymer (EPDM) membranes was developed in a swelling solvent with acetyl sulfate. This procedure avoids the need to pre-dissolve the raw polymer. The reaction conditions were optimized in terms of solvent type, reaction time, acetyl sulfate concentration and film thickness to obtain the maximum degree of sulfonation of the polymer. The sulfonation procedure presented in this study yields a degree of sulfonation comparable to the chlorosulfonic acid procedure. Sulfonic acid groups were detected by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, and quantified by titrations. Proton conductivity and water uptake were measured by means of impedance spectroscopy and swelling measurements, respectively, and were correlated with the degree of sulfonation. Tensile strength and Young's modulus of sulfonated EPDM increased with the degree of sulfonation, while elongation at break remained constant. Thermal stability of the sulfonated EPDM was studied by simultaneous thermogravimetry-mass spectroscopy

Study of cross-linking reactions induced by gamma rays in hybrid membranes of Bisphenol-A-Polysulfone and precipitated silica

International Nuclear Information System (INIS)

Furtado Filho, Acacio Antonio M.; Gomes, Ailton de S.; Lopes, Lea; Benzi, Marcia R.

2011-01-01

In this work the bisphenol-A-polysulfone (PSF) was sulfonated using trimethyl silyl chlorosulfonate [(CH 3 ) 3 SiSO 3 Cl] as a mild sulfonating agent in a homogeneous solution of dichloroethane. The sulfonation reaction was confirmed by acid-base titration and FTIR-spectroscopy analysis. The hybrid membranes were obtained by casting the sulfonated bisphenol-A-polysulfone (SPSF) and precipitated silica Tixosil R 333 solutions in N-N-dimethylacetamide. Cross-linking in the hybrid membranes was obtained by irradiation, with doses ranging from 5 to 30 kGy using gamma ray from a 60 Co source. The water uptake and the swelling of the membranes were estimated by measuring the change in weight between dry and wet conditions. The conductivity of the membranes in acid form was measured with the ac impedance technique using a PGSTAT30 frequency response analyzer. The hybrid cross-linked membranes have conductivity close to 10-1 S.cm -1 at 100% RH and 80 deg C. Electrochemical performances, thermo-mechanical stability and low cost make this cross-linked SPSF hybrid membrane an attractive material for fuel cells using a proton exchange membrane. (author)

Glycerol etherification with TBA: high yield to poly-ethers using a membrane assisted batch reactor.

Science.gov (United States)

Cannilla, Catia; Bonura, Giuseppe; Frusteri, Leone; Frusteri, Francesco

2014-05-20

In this work, a novel approach to obtain high yield to poly-tert-butylglycerolethers by glycerol etherification reaction with tert-butyl alcohol (TBA) is proposed. The limit of this reaction is the production of poly-ethers, which inhibits the formation of poly-ethers potentially usable in the blend with conventional diesel for transportation. The results herein reported demonstrate that the use of a water permselective membrane offers the possibility to shift the equilibrium toward the formation of poly-ethers since the water formed during reaction is continuously and selectively removed from the reaction medium by the recirculation of the gas phase. Using a proper catalyst and optimizing the reaction conditions, in a single experiment, a total glycerol conversion can be reached with a yield to poly-ethers close to 70%, which represents data never before reached using TBA as reactant. The approach here proposed could open up new opportunities for all catalytic reactions affected by water formation.

Ultraviolet-induced surface grafting of octafluoropentyl methacrylate on polyether ether ketone for inducing antibiofilm properties.

Science.gov (United States)

Amdjadi, Parisa; Nojehdehian, Hanieh; Najafi, Farhood; Ghasemi, Amir; Seifi, Massoud; Dashtimoghadam, Erfan; Fahimipour, Farahnaz; Tayebi, Lobat

2017-07-01

Since octafluoropentyl methacrylate is an antifouling polymer, surface modification of polyether ether ketone with octafluoropentyl methacrylate is a practical approach to obtaining anti-biofilm biocompatible devices. In the current study, the surface treatment of polyether ether ketone by the use of ultraviolet irradiation, so as to graft (octafluoropentyl methacrylate) polymer chains, was initially implemented and then investigated. The Fourier-transform infrared and nuclear magnetic resonance spectra corroborated the appearance of new signals associated with the fluoroacrylate group. Thermogravimetric curves indicated enhanced asymmetry in the polymer structure due to the introduction of the said new groups. Measuring the peak area in differential scanning calorimetry experiments also showed additional bond formation. Static water contact angle measurements indicated a change in wettability to the more hydrophobic surface. The polyether ether ketone-octafluoropentyl methacrylate surface greatly reduced the protein adsorption. This efficient method can modulate and tune the surface properties of polyether ether ketone according to specific applications.

Epoxide-Opening Cascades in the Synthesis of Polycyclic Polyether Natural Products

Science.gov (United States)

2009-01-01

The group of polycyclic polyether natural products is of special interest due to the fascinating structure and biological effects displayed by its members. The latter includes potentially therapeutic antibiotic, antifungal, and anticancer properties, as well as extreme lethality. The polycyclic structural features of this family can, in some cases, be traced to their biosynthetic origin, but in others that are less well understood, only to proposed biosynthetic pathways that feature dramatic, yet speculative, epoxide–opening cascades. In this review we summarize how such epoxide–opening cascade reactions have been used in the synthesis of polycyclic polyethers and related natural products. PMID:19572302

Radiation effect of polyether-urethane under action of different ionizing radiation

International Nuclear Information System (INIS)

Huang Wei; Chen Xiaojun; Gao Xiaoling; Xu Yunshu; Fu Yibei

2006-01-01

The research concerns in the radiation effect of γ-ray and electron beam on polyether-urethane. The thermal property and radical intensity were determined by differential thermal gravimetric analysis and electron spin resonance. The composition and content of gas products from samples irradiated by different ionizing radiation were analyzed by gas chromatography. The action mechanism of these two radiation resources of γ-ray and electron beam are same, but the means of energy deposit is different. It results in the differences of radical intensity and the thermal property of polyether-urethane as well as its gas products from the radiation decomposition. (authors)

Polyether ether ketone film. Polyether ether ketone film

Energy Technology Data Exchange (ETDEWEB)

Suzuki, S. (Sumitomo Chemical Co. Ltd., Tokyo (Japan))

1990-07-05

The characteristics and the film making process of polyether ether ketone (PEEK) resin, and the characteristics and the applications of PEEK film, are described. PEEK is aromatic polyketone with super thermal resistance. Though it is a crystalline polymer of which the crystallinity is controlled to 48% in a highest degree, it has also amorphous property, thus it shows unique property. The characteristics of PEEK resin are found in thermal resistance, incombusti-bility, transparency, chemical resistance, light resistance and radiation resistance. As for the film making process, casting method by T-die is generally adopted. The general properties of PEEK film are excellent in high thermal resistance, good electrical properties, chemical resistance, hydrolysis resistance, radiation resistance and imcombusti-bility. In the application of PEEK film, new development is expected in following fields; a high performance composite, flexible print substrate with high thermal resistance, insulating tape with thermal resistance, and a general film in the nuclear energy industry. 5 figs., 5 tabs.

Sulfonated 1,3-bis(4-pyridylpropane

Directory of Open Access Journals (Sweden)

Ore Kuyinu

2011-06-01

Full Text Available In the title compound, 4-[3-(3-sulfonatopyridin-1-ium-4-ylpropyl]pyridin-1-ium-3-sulfonate, C13H14N2O6S2, the molecule is zwitterionic, with the sulfonic acid proton transfered to the basic pyridine N atom. Also, the structure adopts a butterfly-like conformation with the sulfonate groups on opposite sides of the `wings'. The dihedral angle between the two pyridinium rings is 83.56 (7°, and this results in the molecule having a chiral conformation and packing. There is strong intermolecular hydrogen bonding between the pyridinium H and sulfonate O atoms of adjoining molecules. In addition, there are weaker intermolecular C—H...O interactions.

Parasite infection accelerates age polyethism in young honey bees

DEFF Research Database (Denmark)

Lecocq, Antoine; Jensen, Annette Bruun; Kryger, Per

2016-01-01

micro-colonies of honey bees and video analyses to track the effects of N. ceranae infection and exposure on a range of individual and social behaviours in young adult bees. We provide detailed data showing that N. ceranae infection significantly accelerated the age polyethism of young bees, causing......Honey bees (Apis mellifera) are important pollinators and their health is threatened worldwide by persistent exposure to a wide range of factors including pesticides, poor nutrition, and pathogens. Nosema ceranae is a ubiquitous microsporidian associated with high colony mortality. We used lab...... manipulation to increase colony infection. However, reduction in queen contacts could help bees limit the spread of infection. Such accelerated age polyethism may provide a form of behavioural immunity, particularly if it is elicited by a wide variety of pathogens....

Lithium-conducting ionic melt electrolytes from polyether-functionalized fluorosulfonimide anions

International Nuclear Information System (INIS)

Hallac, B.B.; Geiculescu, O.E.; Rajagopal, R.V.; Creager, S.E.; DesMarteau, D.D.

2008-01-01

Solvent-free lithium-conducting ionic melt (IM) electrolytes were synthesized and characterized with respect to chemical structure, purity, and ion transport properties. The melts consist of lithium (perfluorovinylether)sulfonimide salts attached covalently to a lithium-solvating polyether chain. Ionic conductivities are relatively high which is a consequence of the favorable combination of the low lattice energy of the lithium fluorosulfonimide salt (low basicity of the fluorosulfonimide anion), the relatively low viscosity of the polyether matrix, and the relatively high salt content of the melts. Galvanostatic dc polarization experiments, using cells with non-blocking Li electrodes, indicate that salt concentration polarization does not occur in these electrolytes as dc current is passed through them

Antimalarial effects of vinyl sulfone cysteine proteinase inhibitors.

OpenAIRE

Rosenthal, P J; Olson, J E; Lee, G K; Palmer, J T; Klaus, J L; Rasnick, D

1996-01-01

We evaluated the antimalarial effects of vinyl sulfone cysteine proteinase inhibitors. A number of vinyl sulfones strongly inhibited falcipain, a Plasmodium falciparum cysteine proteinase that is a critical hemoglobinase. In studies of cultured parasites, nanomolar concentrations of three vinyl sulfones inhibited parasite hemoglobin degradation, metabolic activity, and development. The antimalarial effects correlated with the inhibition of falcipain. Our results suggest that vinyl sulfones or...

PEMFC performance of MEAS based on Nafion{sup R} and sPSEBS hybrid membranes

Energy Technology Data Exchange (ETDEWEB)

Fernandez-Carretero, F.J.; Compan, V. [Univ, Politecnica de Valencia, Valencia (Spain). Dept. Termodinamica Aplicada; Suarez, K.; Solorza, O. [Inst. Politecnico Nacional, Centro de Investigacion y de Estudios Avanzados, Mexico City (Mexico). Dept. de Quimica; Riande, E. [Inst. de Ciencia y Tecnologia de Polimeros, Madrid (Spain)

2010-07-15

Important scientific, technical and economic problems must be solved before widespread commercialization of polymer electrolyte membrane fuel cells (PEMFC). The main issues facing the development of commercial low temperature fuel cells are the synthesis of efficient solid electrolytes separating the anode from the cathode as well as the development of cheaper catalysts for fuel oxidation. This study involved the preparation of hybrid membranes based on Nafion 117 and sulfonated Calprene H6120 containing partially sulfonated inorganic fillers such as silica, SBA-15 and sepiolite. The feasibility of using the membranes as polyelectrolytes for low temperature fuel cells was then evaluated. The water uptake of Nafion hybrid membranes is 1/3 to 1/4 of that in composite membranes based on sulfonated Calprene H6120. The proton conductivity of Nafion 117 hybrid membranes-electrode assemblies is nearly 1/5 of the pristine Nafion membrane assembly. Sulfonated Calprene H6120 hybrid membranes typically have better proton conductivity than the Nafion 117 composites. The performance of fuel cells containing different MEAs was examined by measuring their polarization curves in different operating conditions. The kinetic parameters governing the voltage dependence on current density were also estimated. It was concluded that the superior performance of the fuel cells with MEAs of NAF-SEP, sPSEBS-SIL and sPSEBS-SBA is not due to the membranes themselves, but to the kinetic processes that occur at the electrodes, which in this study were less efficient for fuel cells with the Nafion MEA. 34 refs., 3 tabs., 9 figs.

Ionizable polyethers as specific metal ion carriers in liquid-liquid extraction and liquid membrane separations

International Nuclear Information System (INIS)

Walkowiak, W.; Charewicz, W.A.; Bartsch, R.A.; Ndip, G.M.

1988-01-01

Consideration is given to results of investigations into competitive extraction and penetration through a liquid membrane of alkali and alkaline earth cations from aqueous solutions by a series of lipophilic and ionizable acyclic polyethers of various molecular structure. It is shown that specificity and selectiviy of cation carriers in liquid-liquid extraction and liquid membrane separation depend on molecular structure of acyclic polyethers

New bromotriterpene polyethers from the Indian alga Chondria armata

Digital Repository Service at National Institute of Oceanography (India)

Ciavatta, M.L.; Wahidullah, S.; DeSouza, L.; Scognamiglio, G.; Cimino, G.

Six new bromotriterpene polyethers, armatol A-F (1-6), with a rearranged carbon skeleton, were isolated from the Indian Ocean red alga Chondria armata. The structures were characterized by spectroscopic techniques, in particular 1D- and 2D-NMR...

Blood Compatibility of Sulfonated Cladophora Nanocellulose Beads

Directory of Open Access Journals (Sweden)

Igor Rocha

2018-03-01

Full Text Available Sulfonated cellulose beads were prepared by oxidation of Cladophora nanocellulose to 2,3-dialdehyde cellulose followed by sulfonation using bisulfite. The physicochemical properties of the sulfonated beads, i.e., high surface area, high degree of oxidation, spherical shape, and the possibility of tailoring the porosity, make them interesting candidates for the development of immunosorbent platforms, including their application in extracorporeal blood treatments. A desired property for materials used in such applications is blood compatibility; therefore in the present work, we investigate the hemocompatibility of the sulfonated cellulose beads using an in vitro whole blood model. Complement system activation (C3a and sC5b-9 levels, coagulation activation (thrombin-antithrombin (TAT levels and hemolysis were evaluated after whole blood contact with the sulfonated beads and the results were compared with the values obtained with the unmodified Cladophora nanocellulose. Results showed that neither of the cellulosic materials presented hemolytic activity. A marked decrease in TAT levels was observed after blood contact with the sulfonated beads, compared with Cladophora nanocellulose. However, the chemical modification did not promote an improvement in Cladophora nanocellulose hemocompatibility in terms of complement system activation. Even though the sulfonated beads presented a significant reduction in pro-coagulant activity compared with the unmodified material, further modification strategies need to be investigated to control the complement activation by the cellulosic materials.

Blood Compatibility of Sulfonated Cladophora Nanocellulose Beads.

Science.gov (United States)

Rocha, Igor; Lindh, Jonas; Hong, Jaan; Strømme, Maria; Mihranyan, Albert; Ferraz, Natalia

2018-03-07

Sulfonated cellulose beads were prepared by oxidation of Cladophora nanocellulose to 2,3-dialdehyde cellulose followed by sulfonation using bisulfite. The physicochemical properties of the sulfonated beads, i.e., high surface area, high degree of oxidation, spherical shape, and the possibility of tailoring the porosity, make them interesting candidates for the development of immunosorbent platforms, including their application in extracorporeal blood treatments. A desired property for materials used in such applications is blood compatibility; therefore in the present work, we investigate the hemocompatibility of the sulfonated cellulose beads using an in vitro whole blood model. Complement system activation (C3a and sC5b-9 levels), coagulation activation (thrombin-antithrombin (TAT) levels) and hemolysis were evaluated after whole blood contact with the sulfonated beads and the results were compared with the values obtained with the unmodified Cladophora nanocellulose. Results showed that neither of the cellulosic materials presented hemolytic activity. A marked decrease in TAT levels was observed after blood contact with the sulfonated beads, compared with Cladophora nanocellulose. However, the chemical modification did not promote an improvement in Cladophora nanocellulose hemocompatibility in terms of complement system activation. Even though the sulfonated beads presented a significant reduction in pro-coagulant activity compared with the unmodified material, further modification strategies need to be investigated to control the complement activation by the cellulosic materials.

Effects of poly-ether B on proteome and phosphoproteome expression in biofouling Balanus amphitrite cyprids

KAUST Repository

Dash, Swagatika

2012-04-01

Biofouling is ubiquitous in marine environments, and the barnacle Balanus amphitrite is one of the most recalcitrant and aggressive biofoulers in tropical waters. Several natural antifoulants that were claimed to be non-toxic have been isolated in recent years, although the mechanism by which they inhibit fouling is yet to be investigated. Poly-ether B has shown promise in the non-toxic inhibition of larval barnacle attachment. Hence, in this study, multiplex two-dimensional electrophoresis (2-DE) was applied in conjunction with mass spectrometry to investigate the effects of poly-ether B on barnacle larvae at the molecular level. The cyprid proteome response to poly-ether B treatment was analyzed at the total proteome and phosphoproteome levels, with 65 protein and 19 phosphoprotein spots found to be up- or down-regulated. The proteins were found to be related to energy-metabolism, oxidative stress, and molecular chaperones, thus indicating that poly-ether B may interfere with the redox-regulatory mechanisms governing the settlement of barnacle larvae. The results of this study demonstrate the usefulness of the proteomic technique in revealing the working mechanisms of antifouling compounds. © 2012 Copyright Taylor and Francis Group, LLC.

A study of the effect of polystyrene sulfonation on the performance of terephthaloyl chloride-dihydroxydiphenyl sulfone copolymer/polystyrene system

Science.gov (United States)

Kahraman, R.; Kahn, K. A.; Ali, S. A.; Hamid, S. H.; Sahin, A. Z.

1998-12-01

Thermal, morphological, and mechanical properties of composites of a liquid crystalline copolymer (LCP) poly(terephthaloyl chloride)-co-(p,p’-dihydroxydiphenyl sulfone) with polystyrene (PS) and sulfonated polystyrene (SPS) are presented and discussed. Sulfonation of polystyrene was expected to improve the interfacial adhesion by introducing hydrogen bonding in the LCP/PS system. The degree of sulfonation was 11 %. The incompatibility (lack of proper interfacial adhesion) of the LCP/PS system resulted in sharp decrease in the composite tensile strength with LCP addition. The performance of the system did not change when processed at a higher temperature (270 °C instead of 225 °C). While a composite plate of 25% LCP/PS could not be fabricated, it was possible for LCP/SPS (processed at 215 °C), indicating some improvement in interfacial bonding by sulfonation. Sulfonation of PS resulted in fracture with some degree of plastic deformation for pure SPS matrix and also the LCP/SPS system with the lowest LCP content (1 wt%), whereas plastic deformation was not observed for PS used as received. The strength of the LCP/SPS system also decreased with increase in LCP content, indicating that 11% sulfonation is not sufficient to introduce significant compatibility, but it was not as dramatic as that for LCP/PS. The performance of the LCP/SPS system was not affected significantly by heat treatment at the process temperature.

Sulfonated polyphenyl ether by electropolymerization

International Nuclear Information System (INIS)

Hou Hongying; Vacandio, Florence; Di Vona, Maria Luisa; Knauth, Philippe

2012-01-01

Highlights: ► Sulfonated polyphenyl ether was for the first time electropolymerized. ► This technique allows the economical preparation of ionomeric membranes for electrochemical energy technologies. ► The mechanism of electropolymerization was discussed in detail. - Abstract: Electropolymerization of sulfonated phenol was for the first time achieved and studied by cyclic voltammetry (CV) and chronoamperometry on stainless steel substrates. The obtained sulfonated polyphenyl ether was characterized in terms of impedance spectroscopy, nuclear magnetic resonance (NMR), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and Fourier-Transform Infrared (FTIR) spectroscopy. Dense films of micrometer thickness can be obtained; the proton conductivity is about 3 mS/cm at room temperature.

Enzymatic catalysis of anti-Baldwin ring closure in polyether biosynthesis.

Science.gov (United States)

Hotta, Kinya; Chen, Xi; Paton, Robert S; Minami, Atsushi; Li, Hao; Swaminathan, Kunchithapadam; Mathews, Irimpan I; Watanabe, Kenji; Oikawa, Hideaki; Houk, Kendall N; Kim, Chu-Young

2012-03-04

Polycyclic polyether natural products have fascinated chemists and biologists alike owing to their useful biological activity, highly complex structure and intriguing biosynthetic mechanisms. Following the original proposal for the polyepoxide origin of lasalocid and isolasalocid and the experimental determination of the origins of the oxygen and carbon atoms of both lasalocid and monensin, a unified stereochemical model for the biosynthesis of polyether ionophore antibiotics was proposed. The model was based on a cascade of nucleophilic ring closures of postulated polyepoxide substrates generated by stereospecific oxidation of all-trans polyene polyketide intermediates. Shortly thereafter, a related model was proposed for the biogenesis of marine ladder toxins, involving a series of nominally disfavoured anti-Baldwin, endo-tet epoxide-ring-opening reactions. Recently, we identified Lsd19 from the Streptomyces lasaliensis gene cluster as the epoxide hydrolase responsible for the epoxide-opening cyclization of bisepoxyprelasalocid A to form lasalocid A. Here we report the X-ray crystal structure of Lsd19 in complex with its substrate and product analogue to provide the first atomic structure-to our knowledge-of a natural enzyme capable of catalysing the disfavoured epoxide-opening cyclic ether formation. On the basis of our structural and computational studies, we propose a general mechanism for the enzymatic catalysis of polyether natural product biosynthesis. © 2012 Macmillan Publishers Limited. All rights reserved

Properties of polypyrrole doped with alkylbenzene sulfonates

DEFF Research Database (Denmark)

Bay, Lasse; Skaarup, Steen; West, Keld

2001-01-01

-standing 10 mu m thick film is prepared electrochemically at a constant current from an aqueous solution of pyrrole and sodium alkylbenzene sulfonate. The mechanical properties of the film (tensile strength and Young's modulus) and the reversible linear elongation between the oxidised and reduced states...... are measured. Alkylbenzene sulfonates with alkyl chain lengths between 1 and 22 carbon atoms are used as dopant anion. The films made with the different anions have highly different properties and are here compared to outline the influence of the size of the anion. A maximum in linear elongation is found for p......-(n-octyl)benzene sulfonate and in conductivity for p-(n-butyl)benzene sulfonate....

Alkyl Substitution Effect on Oxidation Stability of Sulfone-Based Electrolytes

Energy Technology Data Exchange (ETDEWEB)

Su, Chi-Cheung [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; He, Meinan [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Redfern, Paul [Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Curtiss, Larry A. [Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Liao, Chen [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Zhang, Lu [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Burrell, Anthony K. [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Zhang, Zhengcheng [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA

2016-02-16

Organic sulfone compounds have been widely used as high-voltage electrolytes for lithium-ion batteries for decades. However, owing to the complexity of the synthesis of new sulfones, only a few commercially available sulfones have been studied. In this paper, we report the synthesis of new sulfone compounds with various substituent groups and the impact of the substituent group on the oxidation stability of sulfones. Electrochemical floating tests using a 5 V LiNi0.5Mn1.5O4 spinel cathode and density functional theory calculations showed that the cyclopentyl-substituted sulfone McPS suffered from oxidation instability, starting from 4.9 V versus Li+/Li, as observed by the large leakage currents. On the other hand, the isopropyl-substituted sulfone MiPS and tetramethylene substituted sulfone TMS showed much improved oxidation stability under identical testing conditions. The substitution structure of the sulfone plays a significant role in the determination of its oxidative stability and should first be considered for the development of new sulfone-based electrolytes for high-voltage, high-energy lithium-ion batteries.

Composite Membranes Based on Polyether Sulfone

Directory of Open Access Journals (Sweden)

A. Soroush

2010-12-01

Full Text Available The role of polymeric additives such as PVP and PEG is studied with respect to the morphology of PES porous layer as a sublayer of nanofiltration composite membranes based on PES/PA. Results show that by phase inversionprocess of quaternary systems comprised of four components of polymer/solvent/non-solvent/additive and the diffusion of intertwined polymers some changes occur in membrane morphology with changes in their concentration. With addition of PVP, tear-like pores, finger-like and channel-like morphology change to enlarged channel cavities and by adding more PVP, membrane morphology changes further and spongy regions are extended in the membrane. Presence of PEG in casting solution delayed the precipitation time. By adding PEG, the solution viscosity is increased which is followed by decreases in diffusion rates of solvent/non-solvent in coagulation bath.Therefore, membrane morphology shifts to small pores and spongier region. Another effect of increased PEG content would be deformed PA layer formation in PES sublayer which affects membrane performance. However, PVP as an additive does not change membrane salt rejection very much while it leads to higher fluxes. A membrane with 2.5 percent PVP would perform by 40 percent flux increases, while a membrane with 5% PVP shows flux reductions even below the initial value. Contrary to PVP, the PEG content of 20 percent leads to 4 folds flux increases and in a membrane with 50 percent PEG, there is a flux increase by 7 folds and drop in salt rejection occurs by 50 percent and 70 percent, respectively.

Poly(ether ester amide)s for tissue engineering

NARCIS (Netherlands)

Deschamps, A.A.; van Apeldoorn, Aart A.; de Bruijn, Joost Dick; Grijpma, Dirk W.; Feijen, Jan

2003-01-01

Poly(ether ester amide) (PEEA) copolymers based on poly(ethylene glycol) (PEG), 1,4-butanediol and dimethyl-7,12-diaza-6,13-dione-1,18-octadecanedioate were evaluated as scaffold materials for tissue engineering. A PEEA copolymer based on PEG with a molecular weight of 300 g/mol and 25 wt% of soft

Chemodiversity of Ladder-Frame Prymnesin Polyethers in Prymnesium parvum

DEFF Research Database (Denmark)

Rasmussen, Silas Anselm; Meier, Sebastian; Andersen, Nikolaj Gedsted

2016-01-01

Blooms of the microalga Prymnesium parvum cause devastating fish kills worldwide, which are suspected to be caused by the supersized ladder-frame polyether toxins prymnesin-1 and -2. These toxins have, however, only been detected from P. parvum in rare cases since they were originally described two...

Thermodynamic parameters for polyether adducts with neutral molecules

International Nuclear Information System (INIS)

Spencer, J.N.; Zafar, A.I.; Ganunis, T.F.

1992-01-01

Using calorimetry, thermodynamic parameters for the interaction of neutral molecules with polyether adducts are determined. When compared to its analogous acyclic ether, no macrocyclic effect is observed for 12-crown-4. The ether's collective oxygen atoms' action determines interaction with acetonitrile and malononitrile, with dimethyltin dichloride having a specific oxygen-binding site. 14 refs., 1 tab

Wettability changes in polyether impression materials subjected to immersion disinfection.

Science.gov (United States)

Shetty, Shweta; Kamat, Giridhar; Shetty, Rajesh

2013-07-01

Disinfection of impression materials prevents cross-contamination; however, the disinfectants may alter the wettability property. The purpose of this investigation was to evaluate the wettability changes of polyether impression material after immersing in four different chemical disinfectant solutions for a period of 10 min and 30 min, respectively. A total of 45 samples of polyether dental impression material (Impregum soft, 3MESPE, St. Paul, MN, USA) were randomly divided into nine groups with five specimens each. Each specimen was disc shaped, flat of 32 mm diameter and 3 mm thickness. The samples were immersed in four disinfectant solutions: 2% Glutaraldehyde, 5% sodium hypochlorite, 0.05% iodophor, and 5.25% phenol for 10 min and 30 min, respectively. The control was without disinfection. Wettability of the samples was assessed by measuring the contact angle by using the Telescopic Goniometer. Data were subjected to analysis of variance (Fisher's test) and Tukey's post hoc test for multiple comparisons at 5% level of significance. The contact angle of 20.21° ± 0.22° were recorded in the control samples. After 10 min, the samples that were immersed in 5% sodium hypochlorite and 5.25% phenol showed significant statistical increase in the contact angle as compared to the control (P polyether material. Within the limitations of the study, 2% glutaraldehyde proved safe for 10 min of immersion disinfection while 0.05% iodophor holds promise as an effective disinfectant without affecting the wettability of the material.

A NOVEL RHODAMINE-BASED FLUORESCENCE CHEMOSENSOR CONTAINING POLYETHER FOR MERCURY (II IONS IN AQUEOUS SOLUTION

Directory of Open Access Journals (Sweden)

Wenqi Du

Full Text Available A novel rhodamine-based Hg2+ chemosensor P2 containing polyether was readily synthesized and investigated, which displayed high selectivity and sensitivity for Hg2+. Because of good water-solubility of polyther, the rhodamine-based chemosensor containing polyether can be used in aqueous solution. The sensor responded rapidly to Hg2+ in pure water solutions with a 1:1 stoichiometry. Meanwhile, it indicated excellent adaptability and also the responsiveness.

Treating shale oil to obtain sulfonates

Energy Technology Data Exchange (ETDEWEB)

Schaeffer, H

1921-01-21

The process shows as its principal characteristics: (1) treating the oil with chlorsulfonic acid at a temperature of about 100/sup 0/C; (2) the transformation of the sulfonic acid obtained into salts; (3) as new industrial products, the sulfonates obtained and their industrial application as disinfectants for hides and wood.

Absorption infrared spectra of interaction products of cyclic polyethers 18-crown-6 and dibenzo-18-crown-6 with uranyl dinitrate hexahydrate

International Nuclear Information System (INIS)

Chumaevskij, N.A.; Belomestnykh, V.I.; Razgonyaeva, G.A.; Shabel'nik, K.S.; Afanas'eva, E.E.

1988-01-01

Using the method of IR spectroscopy it is established that during interaction of uranyl nitrate hexahydrate (UNH) with crown-ethers under investigation macrocycles adhere to UO 2 2+ via hydrogen bonds between water molecules and oxygen of polyethers. Interaction of UNH with the above-mentioned crowns leads to conformational rearrangement of cycles of polyethers and improvement of their symmetry, reflecting in noticeable simplification of IR spectra of interaction products as compared to spectra of initial cyclic polyethers

A Comparative Evaluation of the Linear Dimensional Accuracy of Four Impression Techniques using Polyether Impression Material

OpenAIRE

Manoj, Smita Sara; Cherian, K. P.; Chitre, Vidya; Aras, Meena

2013-01-01

There is much discussion in the dental literature regarding the superiority of one impression technique over the other using addition silicone impression material. However, there is inadequate information available on the accuracy of different impression techniques using polyether. The purpose of this study was to assess the linear dimensional accuracy of four impression techniques using polyether on a laboratory model that simulates clinical practice. The impression material used was Impregu...

Hybrid ion-exchange membranes for fuel cells and separation processes

Energy Technology Data Exchange (ETDEWEB)

Fernandez-Carretero, F.J.; Compan, V. [Departamento de Termodinamica Aplicada, ETSII, Universidad Politecnica de Valencia, 46020 Valencia (Spain); Riande, E. [Instituto de Ciencia y Tecnologia de Polimeros (CSIC), 28006 Madrid (Spain)

2007-11-08

This work reports the preparation and characterization of hybrid membranes cast from dispersions of inorganic fillers in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene solutions. Silica gel, SBA-15 and sepiolite, all of them functionalized with phenylsulfonic acid groups, were used as fillers. For comparative purposes, the performance of composite membranes cast from dispersions of functionalized inorganic fillers in Nafion {sup registered} solutions was investigated. Inspection of the texture of the membranes by using SEM techniques shows that the fillers are better dispersed in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene than in Nafion {sup registered}. The value of the water uptake for the membranes prepared from the former polyelectrolyte is in most cases at least three times that measured for hybrid Nafion {sup registered} membranes. The conductivity of the membranes was measured at 80 C by impedance spectroscopy obtaining values of 3.44, 6.90 and 3.54 S m{sup -1} for the hybrid membranes based on the triblock copolymer containing functionalized silica gel, SBA-15 and sepiolite fillers, respectively. These results compare very favourably with those obtained at 80 C for Nafion {sup registered} hybrid membranes containing silica gel, SBA-15 and sepiolite, all of them fuctionalized with phenylsulfonic acid groups, whose conductivities are, 2.84, 6.75 and 3.31 S m{sup -1}, respectively. Resistance measurements carried out under controlled humidity conditions show that the conductivity of sulfonated triblock copolymer membranes containing functionalized SBA-15 filler undergoes a rather sharp increase when they are conditioned under an atmosphere of 75%, or larger, relative humidity. (author)

Extraction of Mo, W and Tc with polyurethane foam and with cyclic polyether from SCN-/HC1 medium

International Nuclear Information System (INIS)

Caletka, R.; Hausbeck, R.; Krivan, V.

1986-01-01

The extraction of molybdenum, tungsten and technetium by polyether-based polyurethane foam and by a cyclic polyether from aqueous thiocyanate solutions is described. The influence of the reductants stannous chloride and ascorbic acid has also been studied. The possibilites of the polyurethane foam for preconcentration and determination of molybdenum are discussed. (author)

Controlled release of non-steroidal antiinflammatory and anticancer drugs from hybrid materials

International Nuclear Information System (INIS)

Caravieri, Beatriz Bernardes; Molina, Eduardo Ferreira

2016-01-01

Full text: Chronic inflammation is a well known risk factor for the development of human cancer, and at least one third of all human cancers have been associated with inflammation. This can lead to cellular proliferation, a process which per se increases the risk of abnormal cell formation and ultimately the development of cancer. For treating clinical conditions such as inflammation and cancer, the most common methods (e.g., oral administration, injection) can cause unwanted side effects due to drug delivery to non-target sites and the introduction of high doses of the drug to reach the desired location. An alternative to these problems is the preparation of materials that can release drugs with different activities. Thinking about it, the aim of this study was to use a class of hybrid materials based on siloxane-polyether known as ureasil for controlled release of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (IBU) and naproxen (NAP), and anticancer, such as 5-fluorouracil (5- FU). These drugs have been incorporated in the matrix in different proportions and thereafter, were characterized by different techniques such as XRD, FTIR, DSC and SAXS. In addition, it has been evaluated the release kinetics of these species with different chemical structures. The results have shown that the drug molecules were homogeneously distributed in the xerogel hybrids, which contributed to the drug’s release profile fine-tuning. The chemical environment of the polyether chains was amended by incorporating the drugs. The analysis from XRD, FTIR, SAXS and DSC confirm the good solubility of the substances within hybrid matrix. This hybrid material based on polymers and inorganic compounds may have potential applications in human health. (author)

Controlled release of non-steroidal antiinflammatory and anticancer drugs from hybrid materials

Energy Technology Data Exchange (ETDEWEB)

Caravieri, Beatriz Bernardes; Molina, Eduardo Ferreira, E-mail: bia_ms_@hotmail.com [Universidade de Franca, SP (Brazil)

2016-07-01

Full text: Chronic inflammation is a well known risk factor for the development of human cancer, and at least one third of all human cancers have been associated with inflammation. This can lead to cellular proliferation, a process which per se increases the risk of abnormal cell formation and ultimately the development of cancer. For treating clinical conditions such as inflammation and cancer, the most common methods (e.g., oral administration, injection) can cause unwanted side effects due to drug delivery to non-target sites and the introduction of high doses of the drug to reach the desired location. An alternative to these problems is the preparation of materials that can release drugs with different activities. Thinking about it, the aim of this study was to use a class of hybrid materials based on siloxane-polyether known as ureasil for controlled release of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (IBU) and naproxen (NAP), and anticancer, such as 5-fluorouracil (5- FU). These drugs have been incorporated in the matrix in different proportions and thereafter, were characterized by different techniques such as XRD, FTIR, DSC and SAXS. In addition, it has been evaluated the release kinetics of these species with different chemical structures. The results have shown that the drug molecules were homogeneously distributed in the xerogel hybrids, which contributed to the drug’s release profile fine-tuning. The chemical environment of the polyether chains was amended by incorporating the drugs. The analysis from XRD, FTIR, SAXS and DSC confirm the good solubility of the substances within hybrid matrix. This hybrid material based on polymers and inorganic compounds may have potential applications in human health. (author)

Sulindac Sulfide, but Not Sulindac Sulfone, Inhibits Colorectal Cancer Growth

Directory of Open Access Journals (Sweden)

Christopher S. Williams

1999-06-01

Full Text Available Sulindac sulfide, a metabolite of the nonsteroidal antiinflammatory drug (NSAID sulindac sulfoxide, is effective at reducing tumor burden in both familial adenomatous polyposis patients and in animals with colorectal cancer. Another sulindac sulfoxide metabolite, sulindac sulfone, has been reported to have antitumor properties without inhibiting cyclooxygenase activity. Here we report the effect of sulindac sulfone treatment on the growth of colorectal carcinoma cells. We observed that sulindac sulfide or sulfone treatment of HCA-7 cells led to inhibition of prostaglandin E2 production. Both sulindac sulfide and sulfone inhibited HCA-7 and HCT-116 cell growth in vitro. Sulindac sulfone had no effect on the growth of either HCA-7 or HCT-116 xenografts, whereas the sulfide derivative inhibited HCA-7 growth in vivo. Both sulindac sulfide and sulfone inhibited colon carcinoma cell growth and prostaglandin production in vitro, but sulindac sulfone had no effect on the growth of colon cancer cell xenografts in nude mice.

Properties, degradation and high temperature fuel cell test of different types of PBI and PBI blend membranes

DEFF Research Database (Denmark)

Li, Qingfeng; Rudbeck, Hans Christian; Chromik, Andreas

2010-01-01

Polybenzimidazoles (PBIs) with synthetically modified structures and their blends with a partially fluorinated sulfonated aromatic polyether have been prepared and characterized for high temperature proton exchange membrane fuel cells. Significant improvement in the polymer chemical stability...

Bisphenol A sulfonation is impaired in metabolic and liver disease

International Nuclear Information System (INIS)

Yalcin, Emine B.; Kulkarni, Supriya R.; Slitt, Angela L.; King, Roberta

2016-01-01

Background: Bisphenol A (BPA) is a widely used industrial chemical and suspected endocrine disruptor to which humans are ubiquitously exposed. The liver metabolizes and facilitates BPA excretion through glucuronidation and sulfonation. The sulfotransferase enzymes contributing to BPA sulfonation (detected in human and rodents) is poorly understood. Objectives: To determine the impact of metabolic and liver disease on BPA sulfonation in human and mouse livers. Methods: The capacity for BPA sulfonation was determined in human liver samples that were categorized into different stages of metabolic and liver disease (including obesity, diabetes, steatosis, and cirrhosis) and in livers from ob/ob mice. Results: In human liver tissues, BPA sulfonation was substantially lower in livers from subjects with steatosis (23%), diabetes cirrhosis (16%), and cirrhosis (18%), relative to healthy individuals with non-fatty livers (100%). In livers of obese mice (ob/ob), BPA sulfonation was lower (23%) than in livers from lean wild-type controls (100%). In addition to BPA sulfonation activity, Sult1a1 protein expression decreased by 97% in obese mouse livers. Conclusion: Taken together these findings establish a profoundly reduced capacity of BPA elimination via sulfonation in obese or diabetic individuals and in those with fatty or cirrhotic livers versus individuals with healthy livers. - Highlights: • Present study demonstrates that hepatic SULT 1A1/1A3 are primarily sulfonate BPA in mouse and human. • Hepatic BPA sulfonation is profoundly reduced steatosis, diabetes and cirrhosis. • With BPA-S detectable in urine under low or common exposures, these findings are novel and important.

Bisphenol A sulfonation is impaired in metabolic and liver disease

Energy Technology Data Exchange (ETDEWEB)

Yalcin, Emine B.; Kulkarni, Supriya R.; Slitt, Angela L., E-mail: angela_slitt@uri.edu; King, Roberta, E-mail: rking@uri.edu

2016-02-01

Background: Bisphenol A (BPA) is a widely used industrial chemical and suspected endocrine disruptor to which humans are ubiquitously exposed. The liver metabolizes and facilitates BPA excretion through glucuronidation and sulfonation. The sulfotransferase enzymes contributing to BPA sulfonation (detected in human and rodents) is poorly understood. Objectives: To determine the impact of metabolic and liver disease on BPA sulfonation in human and mouse livers. Methods: The capacity for BPA sulfonation was determined in human liver samples that were categorized into different stages of metabolic and liver disease (including obesity, diabetes, steatosis, and cirrhosis) and in livers from ob/ob mice. Results: In human liver tissues, BPA sulfonation was substantially lower in livers from subjects with steatosis (23%), diabetes cirrhosis (16%), and cirrhosis (18%), relative to healthy individuals with non-fatty livers (100%). In livers of obese mice (ob/ob), BPA sulfonation was lower (23%) than in livers from lean wild-type controls (100%). In addition to BPA sulfonation activity, Sult1a1 protein expression decreased by 97% in obese mouse livers. Conclusion: Taken together these findings establish a profoundly reduced capacity of BPA elimination via sulfonation in obese or diabetic individuals and in those with fatty or cirrhotic livers versus individuals with healthy livers. - Highlights: • Present study demonstrates that hepatic SULT 1A1/1A3 are primarily sulfonate BPA in mouse and human. • Hepatic BPA sulfonation is profoundly reduced steatosis, diabetes and cirrhosis. • With BPA-S detectable in urine under low or common exposures, these findings are novel and important.

Synthesis in pilot plant scale and physical properties of sulfonated polystyrene

Directory of Open Access Journals (Sweden)

Martins Cristiane R.

2003-01-01

Full Text Available The homogenous sulfonation of polystyrene was developed in a pilot plant scale producing polymers with different sulfonation degrees (18 to 22 mole % of sulfonated styrene units. The reaction yield depends chiefly on the concentration ratio of acetyl sulfate and polystyrene. The morphological and thermal properties of the sulfonated polystyrene obtained by homogeneous sulfonation were studied by means of scanning electron microscopy, differential scanning calorimetry and thermogravimetry. The glass transition temperature of sulfonated polystyrene increases in relation to pure polystyrene and DCp was evaluated in order to confirm the strong interactions among the ~SO3H groups.

Parasite infection accelerates age polyethism in young honey bees

Science.gov (United States)

Lecocq, Antoine; Jensen, Annette Bruun; Kryger, Per; Nieh, James C.

2016-01-01

Honey bees (Apis mellifera) are important pollinators and their health is threatened worldwide by persistent exposure to a wide range of factors including pesticides, poor nutrition, and pathogens. Nosema ceranae is a ubiquitous microsporidian associated with high colony mortality. We used lab micro-colonies of honey bees and video analyses to track the effects of N. ceranae infection and exposure on a range of individual and social behaviours in young adult bees. We provide detailed data showing that N. ceranae infection significantly accelerated the age polyethism of young bees, causing them to exhibit behaviours typical of older bees. Bees with high N. ceranae spore counts had significantly increased walking rates and decreased attraction to queen mandibular pheromone. Infected bees also exhibited higher rates of trophallaxis (food exchange), potentially reflecting parasite manipulation to increase colony infection. However, reduction in queen contacts could help bees limit the spread of infection. Such accelerated age polyethism may provide a form of behavioural immunity, particularly if it is elicited by a wide variety of pathogens. PMID:26912310

Parasite infection accelerates age polyethism in young honey bees.

Science.gov (United States)

Lecocq, Antoine; Jensen, Annette Bruun; Kryger, Per; Nieh, James C

2016-02-25

Honey bees (Apis mellifera) are important pollinators and their health is threatened worldwide by persistent exposure to a wide range of factors including pesticides, poor nutrition, and pathogens. Nosema ceranae is a ubiquitous microsporidian associated with high colony mortality. We used lab micro-colonies of honey bees and video analyses to track the effects of N. ceranae infection and exposure on a range of individual and social behaviours in young adult bees. We provide detailed data showing that N. ceranae infection significantly accelerated the age polyethism of young bees, causing them to exhibit behaviours typical of older bees. Bees with high N. ceranae spore counts had significantly increased walking rates and decreased attraction to queen mandibular pheromone. Infected bees also exhibited higher rates of trophallaxis (food exchange), potentially reflecting parasite manipulation to increase colony infection. However, reduction in queen contacts could help bees limit the spread of infection. Such accelerated age polyethism may provide a form of behavioural immunity, particularly if it is elicited by a wide variety of pathogens.

Competitive solvent extraction of alkaline-earth cations into chloroform by lipophilic acyclic polyether dicarboxylic acids

International Nuclear Information System (INIS)

Kang, S.I.; Czech, A.; Czech, B.P.; Stewart, L.E.; Bartsch, R.A.

1985-01-01

Competitive solvent extraction of alkaline-earth cations from aqueous solutions into chloroform by a series of lipophilic acyclic polyether dicarboxylic acids is reported. The influence of polyether chain length and of terminal carboxylic acid group variation upon extraction selectivity and efficiency is assessed. In the competitive extraction of concentrated magnesium, calcium, strontium and barium chloride solutions, one complexing agent exhibits pronounced selectivity for barium with Ba 2+ /S 2+ = 50, Ba 2+ /Ca 2+ = 250, and no detectable Mg 2+ extraction. 20 references, 3 figures, 1 table

Study on the radiation degradation of polyether-polyurethane induced by electron beam

International Nuclear Information System (INIS)

Huang Wei; Xiong Jie; Chen Xiaojun; Gao Xiaoling; Xu Yunshu; Fu Yibei

2007-01-01

Polyether-urethane samples were irradiated at the dose range from 10 to 2000 kGy by 2 MeV electron beams. Volatile species from the polymer degradation were analyzed quantitatively and qualitatively with GC/MS. Thermal properties and micro-phase separation of the samples were examined by TG and the morphology was studied by TEM and SEM. The results show that the irradiated polyether-polyurethane evolves CO 2 , H 2 , CH 4 and C 2 H 6 , etc. The thermal stabilities between the hard and soft segments in the irradiated samples are different. At high doses, the phase separation in the sample is predominant and the hard segment of sample is more stable. The dose rate affects the soft segment of the irradiated sample much more. (author)

21 CFR 173.395 - Trifluoromethane sulfonic acid.

Science.gov (United States)

2010-04-01

...) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Specific Usage Additives § 173.395 Trifluoromethane sulfonic acid. Trifluoromethane sulfonic acid... acid) may safely be used in the production of cocoa butter substitute from palm oil (1-palmitoyl-2...

Tunable, antibacterial activity of silicone polyether surfactants.

Science.gov (United States)

Khan, Madiha F; Zepeda-Velazquez, Laura; Brook, Michael A

2015-08-01

Silicone surfactants are used in a variety of applications, however, limited data is available on the relationship between surfactant structure and biological activity. A series of seven nonionic, silicone polyether surfactants with known structures was tested for in vitro antibacterial activity against Escherichia coli BL21. The compounds varied in their hydrophobic head, comprised of branched silicone structures with 3-10 siloxane linkages and, in two cases, phenyl substitution, and hydrophilic tail of 8-44 poly(ethylene glycol) units. The surfactants were tested at three concentrations: below, at, and above their Critical Micelle Concentrations (CMC) against 5 concentrations of E. coli BL21 in a three-step assay comprised of a 14-24h turbidometric screen, a live-dead stain and viable colony counts. The bacterial concentration had little effect on antibacterial activity. For most of the surfactants, antibacterial activity was higher at concentrations above the CMC. Surfactants with smaller silicone head groups had as much as 4 times the bioactivity of surfactants with larger groups, with the smallest hydrophobe exhibiting potency equivalent to sodium dodecyl sulfate (SDS). Smaller PEG chains were similarly associated with higher potency. These data link lower micelle stability and enhanced permeability of smaller silicone head groups to antibacterial activity. The results demonstrate that simple manipulation of nonionic silicone polyether structure leads to significant changes in antibacterial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

Great isotope effects in compounding of sodium isotopes by macrocyclic polyether

International Nuclear Information System (INIS)

Knoechel, A.; Wilken, R.D.

1978-01-01

Isotope effects appear in the compounding of the two sodium isotopes 24 Na + and 22 Na + with macrocyclic polyethers, whose value was determined for the 13 best known polyethers. A radiometric process was used for determining the different half life periods of the nuclides used. To separate the compound and non-compound types, these were distributed between water and chloroform. The isotope ratio in the chloroform phase was compared with the output isotope ratio and the separation facfor determined from this. When using crown ethers, there was enrichment of 24 Na + by a significant amount (large crown ether) up to 3.1 +- 0.4% for 18 crown 6. The remarkably high results can be correlated by Biegeleisen's theory with other chemical conditions. There is a report on the first results of transferring these conditions to the H + /T + system. (orig.) [de

Unloaded polyether type polyurethane foams as solid extractants for trace elements

International Nuclear Information System (INIS)

Palagyi, S.; Braun, T.

1992-01-01

Polyether type polyurethane foams (PU) are regular stacks of solid quasi-spherical membranes produced by the reaction of polyisocyanates with polyols of polyether nature in the presence of a catalyst and a blowing agent. Contrary to conventional membrane separations, where a solid membrane is merely a differentially separating agent, or a transport medium, PU foams, apart from separation and preconcentration, also retain, i.e., sorb the species on, or in the membranes. Therefore, PU foam membranes can be considered to act as true sorbents. The membrane properties of PU foam sorbents offer unique advantages over conventional bulk type granular sorbents in rapid, versatile and effective separations and preconcentrations of different compounds from fluid samples. Unloaded PU foam sorbents have received considerable attention in the separation of different trace inorganic species. (author) 74 refs.; 1 fig.; 1 tab

Genetic Screening Strategy for Rapid Access to Polyether Ionophore Producers and Products in Actinomycetes ▿ †

OpenAIRE

Wang, Hao; Liu, Ning; Xi, Lijun; Rong, Xiaoying; Ruan, Jisheng; Huang, Ying

2011-01-01

Polyether ionophores are a unique class of polyketides with broad-spectrum activity and outstanding potency for the control of drug-resistant bacteria and parasites, and they are produced exclusively by actinomycetes. A special epoxidase gene encoding a critical tailoring enzyme involved in the biosynthesis of these compounds has been found in all five of the complete gene clusters of polyether ionophores published so far. To detect potential producer strains of these antibiotics, a pair of d...

Influence of disinfection with peracetic acid and hypochlorite in dimensional alterations of casts obtained from addition silicone and polyether impressions.

Science.gov (United States)

Queiroz, Daher Antonio; Peçanha, Marcelo Massaroni; Neves, Ana Christina Claro; Frizzera, Fausto; Tonetto, Mateus Rodrigues; Silva-Concílio, Laís Regiane

2013-11-01

Dental impressions disinfection is important to reduce the risk of cross contamination but this process may produce dimensional distortions. Peracetic acid is a disinfectant agent with several favorable characteristics yet underutilized in Dentistry. The aim of this paper is to compare the dimensional stability of casts obtained from addition silicone and polyether impressions that were immersed for 10 minutes in a solution of 0.2% peracetic acid or 1% sodium hypochlorite. Sixty samples in type IV gypsum were produced after a master cast that simulated a full crown preparation of a maxillary premolar. Samples were divided in 6 groups (n = 10) according to the impression material and disinfection agent: Group AC--addition silicone control (without disinfectant); Group APA--addition silicone + 0.2% peracetic acid; Group AH--addition silicone + 1% sodium hypochlorite; Group PC--polyether control (without disinfectant); Group PPA--polyether + 0.2% peracetic acid; Group PH--polyether + 1% sodium hypochlorite. Cast height, base and top diameter were measured and a mean value was obtained for each sample and group all data was statistically analyzed (ANOVA, p polyether impressions regardless of the disinfectant materials. It can be concluded that disinfection with the proposed agents did not produce significant alterations of the impressions and the peracetic acid could be considered a reliable material to disinfect dental molds.

Multiblock copolymers with highly sulfonated blocks containing di- and tetrasulfonated arylene sulfone segments for proton exchange membrane fuel cell applications

Energy Technology Data Exchange (ETDEWEB)

Takamuku, Shogo; Jannasch, Patric [Polymer and Materials Chemistry, Department of Chemistry, Lund University (Sweden)

2012-01-15

Multiblock copoly(arylene ether sulfone)s with different block lengths and ionic contents are tailored for durable and proton-conducting electrolyte membranes. Two series of fully aromatic copolymers are prepared by coupling reactions between non-sulfonated hydrophobic precursor blocks and highly sulfonated hydrophilic precursor blocks containing either fully disulfonated diarylsulfone or fully tetrasulfonated tetraaryldisulfone segments. The sulfonic acid groups are exclusively introduced in ortho positions to the sulfone bridges to impede desulfonation reactions and give the blocks ion exchange capacities (IECs) of 4.1 and 4.6 meq. g{sup -1}, respectively. Solvent cast block copolymer membranes show well-connected hydrophilic nanophase domains for proton transport and high decomposition temperatures above 310 C under air. Despite higher IEC values, membranes containing tetrasulfonated tetraaryldisulfone segments display a markedly lower water uptake than the corresponding ones with disulfonated diarylsulfone segments when immersed in water at 100 C, presumably because of the much higher chain stiffness and glass transition temperature of the former segments. The former membranes have proton conductivities in level of a perfluorosulfonic acid membrane (NRE212) under fully humidified conditions. A membrane with an IEC of 1.83 meq. g{sup -1} reaches above 6 mS cm{sup -1} under 30% relative humidity at 80 C, to be compared with 10 mS cm{sup -1} for NRE212 under the same conditions. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Biofilm behavior on sulfonated poly(ether-ether-ketone) (sPEEK)

Energy Technology Data Exchange (ETDEWEB)

Montero, Juan F.D. [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-900 (Brazil); Tajiri, Henrique A.; Barra, Guilherme M.O.; Fredel, Márcio C. [Department of Mechanical Engineering (EMC), Federal University of Santa Catarina (UFSC), Florianópolis, SC 88040-900 (Brazil); Benfatti, Cesar A.M.; Magini, Ricardo S. [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-900 (Brazil); Pimenta, Andréa L. [Integrated Laboratories Technologies (InteLAB), Dept. Chemical Engineering (EQA), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-970 (Brazil); Department of Biologie, Université de Cergy Pontoise, 2, Av. Adolphe Chauvin, 95302 Cergy Pontoise (France); Souza, Júlio C.M., E-mail: julio.c.m.souza@ufsc.br [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-900 (Brazil); Center for Microelectromechanical Systems (CMEMS), Dept. Mechanical Engineering (DEM), Campus Azurém, 4800-058 Guimarães (Portugal)

2017-01-01

Poly(ether-ether-ketone) (PEEK) has also shown to be very attractive for incorporating therapeutic compounds thanks to a sulfonation process which modifies the material structure resulting in a sulfonated-PEEK (sPEEK). Concerning biomedical applications, the objective of this work was to evaluate the influence of different sulfonation degree of sPEEK on the biofilm growth. PEEK samples were functionalized by using sulphuric acid (98%) and then dissolved into dimethyl-sulfoxide. A dip coating technique was used to synthesize sPEEK thin films. The sulfonation degree of the materials was analyzed by FT-IR, H NMR, TG and IEC. The surfaces were characterized by scanning electron microscopy, profilometry and contact angle analyses. Subsequently, the biofilm formation on sulfonated-PEEK based on Streptococcus mutans and Enterococcus faecalis was measured by spectrophotometry, colony forming units (CFU mL{sup −1}) and SEM. Results obtained from thermal and chemical analyses showed an intensification in sulfonation degree for sPEEK at 2 and 2.5 h. The E. faecalis or S. mutans biofilm growth revealed statistically significant differences (p < 0.05) between 2 and 3 h sulfonation groups. A significant decrease (p < 0.05) in CFU mL{sup −1} was recorded for S. mutans or E. faecalis biofilm grown on 2.5 or 3 h sPEEK. Regarding the thermal-chemical and microbiologic analyses, the sulfonation degree of sPEEK ranging from 2 up to 3 h was successful capable to decrease the biofilm growth. That revealed an alternative strategy to embed anti-biofilm and therapeutic compounds into PEEK avoiding infections in biomedical applications. - Highlights: • PEEK can be dissolved to incorporate therapeutic compounds. • High sulfonation degree on sPEEK affected the biofilm growth. • The sulfonation degree must be controlled to maintain the properties of sPEEK.

Biofilm behavior on sulfonated poly(ether-ether-ketone) (sPEEK)

International Nuclear Information System (INIS)

Montero, Juan F.D.; Tajiri, Henrique A.; Barra, Guilherme M.O.; Fredel, Márcio C.; Benfatti, Cesar A.M.; Magini, Ricardo S.; Pimenta, Andréa L.; Souza, Júlio C.M.

2017-01-01

Poly(ether-ether-ketone) (PEEK) has also shown to be very attractive for incorporating therapeutic compounds thanks to a sulfonation process which modifies the material structure resulting in a sulfonated-PEEK (sPEEK). Concerning biomedical applications, the objective of this work was to evaluate the influence of different sulfonation degree of sPEEK on the biofilm growth. PEEK samples were functionalized by using sulphuric acid (98%) and then dissolved into dimethyl-sulfoxide. A dip coating technique was used to synthesize sPEEK thin films. The sulfonation degree of the materials was analyzed by FT-IR, H NMR, TG and IEC. The surfaces were characterized by scanning electron microscopy, profilometry and contact angle analyses. Subsequently, the biofilm formation on sulfonated-PEEK based on Streptococcus mutans and Enterococcus faecalis was measured by spectrophotometry, colony forming units (CFU mL −1 ) and SEM. Results obtained from thermal and chemical analyses showed an intensification in sulfonation degree for sPEEK at 2 and 2.5 h. The E. faecalis or S. mutans biofilm growth revealed statistically significant differences (p < 0.05) between 2 and 3 h sulfonation groups. A significant decrease (p < 0.05) in CFU mL −1 was recorded for S. mutans or E. faecalis biofilm grown on 2.5 or 3 h sPEEK. Regarding the thermal-chemical and microbiologic analyses, the sulfonation degree of sPEEK ranging from 2 up to 3 h was successful capable to decrease the biofilm growth. That revealed an alternative strategy to embed anti-biofilm and therapeutic compounds into PEEK avoiding infections in biomedical applications. - Highlights: • PEEK can be dissolved to incorporate therapeutic compounds. • High sulfonation degree on sPEEK affected the biofilm growth. • The sulfonation degree must be controlled to maintain the properties of sPEEK.

Fully Aromatic Block Copolymers for Fuel Cell Membranes with Densely Sulfonated Nanophase Domains

DEFF Research Database (Denmark)

Takamuku, Shogo; Jannasch, Patrick; Lund, Peter Brilner

Two multiblock copoly(arylene ether sulfone)s with similar block lengths and ion exchange capacities (IECs) were prepared by a coupling reaction between a non-sulfonated precursor block and a highly sulfonated precursor block containing either fully disulfonated diarylsulfone or fully...... tetrasulfonated tetraaryldisulfone segments. The latter two precursor blocks were sulfonated via lithiation-sulfination reactions whereby the sulfonic acid groups were exclu- sively placed in ortho positions to the many sulfone bridges, giving these locks IECs of 4.1 and 4.6 meqg1, respectively. Copolymer...

Effect of mixing techniques on bacterial attachment and disinfection time of polyether impression material.

Science.gov (United States)

Guler, Umut; Budak, Yasemin; Ruh, Emrah; Ocal, Yesim; Canay, Senay; Akyon, Yakut

2013-09-01

The aim of this study was 2-fold. The first aim was to evaluate the effects of mixing technique (hand-mixing or auto-mixing) on bacterial attachment to polyether impression materials. The second aim was to determine whether bacterial attachment to these materials was affected by length of exposure to disinfection solutions. Polyether impression material samples (n = 144) were prepared by hand-mixing or auto-mixing. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were used in testing. After incubation, the bacterial colonies were counted and then disinfectant solution was applied. The effect of disinfection solution was evaluated just after the polymerization of impression material and 30 min after polymerization. Differences in adherence of bacteria to the samples prepared by hand-mixing and to those prepared by auto-mixing were assessed by Kruskal-Wallis and Mann-Whitney U-tests. For evaluating the efficiency of the disinfectant, Kruskal-Wallis multiple comparisons test was used. E. coli counts were higher in hand-mixed materials (P 2.394). The methods used for mixing polyether impression material did not affect bacterial attachment to impression surfaces. In contrast, the disinfection procedure greatly affects decontamination of the impression surface.

Enhanced antifouling and antibacterial properties of poly (ether sulfone) membrane modified through blending with sulfonated poly (aryl ether sulfone) and copper nanoparticles

Science.gov (United States)

Zhang, Jingjing; Xu, Ya'nan; Chen, Shouwen; Li, Jiansheng; Han, Weiqing; Sun, Xiuyun; Wu, Dihua; Hu, Zhaoxia; Wang, Lianjun

2018-03-01

A series of novel blend ultrafiltration (UF) membranes have been successfully prepared from commercial poly (ether sulfone), lab-synthesized sulfonated poly (aryl ether sulfone) (SPAES, 1 wt%) and copper nanoparticles (0 ∼ 0.4 wt%) via immersion precipitation phase conversion. The micro-structure and separation performance of the membranes were characterized by field emission scanning electron microscopy (SEM) and cross-flow filtration experiments, respectively. Sodium alginate, bovine serum albumin and humic acid were chosen as model organic foulants to investigate the antifouling properties, while E. coil was used to evaluate the antibacterial property of the fabricated membranes. By the incorporation with SPAES and copper nanoparticles, the hydrophilicity, antifouling and antibacterial properties of the modified UF membranes have been profoundly improved. At a copper nanoparticles content of 0.4 wt%, the PES/SPAES/nCu(0.4) membrane exhibited a high pure water flux of 193.0 kg/m2 h, reaching the smallest contact angle of 52°, highest flux recovery ratio of 79% and largest antibacterial rate of 78.9%. Furthermore, the stability of copper nanoparticles inside the membrane matrix was also considerably enhanced, the copper nanoparticles were less than 0.08 mg/L in the effluent during the whole operation.

A thin film degradation study of a fluorinated polyether liquid lubricant using an HPLC method

Science.gov (United States)

Morales, W.

1986-01-01

A High Pressure Liquid Chromatography (HPLC) separation method was developed to study and analyze a fluorinated polyether fluid which is promising liquid lubricant for future applications. This HPLC separation method was used in a preliminary study investigating the catalytic effect of various metal, metal alloy, and ceramic engineering materials on the degradation of this fluid in a dry air atmosphere at 345 C. Using a 440 C stainless steel as a reference catalytic material it was found that a titanium alloy and a chromium plated material degraded the fluorinated polyether fluid substantially more than the reference material.

Synthesis and Characterization of Sulfonated Graphene Oxide Reinforced Sulfonated Poly (Ether Ether Ketone (SPEEK Composites for Proton Exchange Membrane Materials

Directory of Open Access Journals (Sweden)

Ning Cao

2018-03-01

Full Text Available As a clean energy utilization device, full cell is gaining more and more attention. Proton exchange membrane (PEM is a key component of the full cell. The commercial-sulfonated, tetrafluoroethylene-based fluoropolymer-copolymer (Nafion membrane exhibits excellent proton conductivity under a fully humidified environment. However, it also has some disadvantages in practice, such as high fuel permeability, a complex synthesis process, and high cost. To overcome these disadvantages, a low-cost and novel membrane was developed. The sulfonated poly (ether ether ketone (SPEEK was selected as the base material of the proton exchange membrane. Sulfonated graphene (SG was cross-linked with SPEEK through the elimination reaction of hydrogen bonds. It was found that the sulfonic acid groups and hydrophilic oxygen groups increased obviously in the resultant membrane. Compared with the pure SPEEK membrane, the SG-reinforced membrane exhibited better proton conductivity and methanol permeability prevention. The results indicate that the SG/SPEEK could be applied as a new proton exchange membrane in fuel cells.

Langmuir and Langmuir-Blodgett films of multifunctional, amphiphilic polyethers with cholesterol moieties.

Science.gov (United States)

Reuter, Sascha; Hofmann, Anna M; Busse, Karsten; Frey, Holger; Kressler, Jörg

2011-03-01

Langmuir films of multifunctional, hydrophilic polyethers containing a hydrophobic cholesterol group (Ch) were studied by surface pressure-mean molecular area (π-mmA) measurements and Brewster angle microscopy (BAM). The polyethers were either homopolymers or diblock copolymers of linear poly(glycerol) (lPG), linear poly(glyceryl glycidyl ether) (lPGG), linear poly(ethylene glycol) (lPEG), or hyperbranched poly(glycerol) (hbPG). Surface pressure measurements revealed that the homopolymers lPG and hbPG did not stay at the water surface after spreading and solvent evaporation, in contrast to lPEG. Because of the incorporation of the Ch group in the polymer structure, stable Langmuir films were formed by Ch-lPG(n), Ch-lPGG(n), and Ch-hbPG(n). The Ch-hbPG(n), Ch-lPEG(n), Ch-lPEG(n)-b-lPG(m), Ch-lPEG(n)-b-lPGG(m), and Ch-lPEG(n)-b-hbPG(m) systems showed an extended plateau region assigned to a phase transition involving the Ch groups. Typical hierarchically ordered morphologies of the LB films on hydrophilic substrates were observed for all Ch-initiated polymers. All LB films showed that Ch of the Ch-initiated homopolymers is able to crystallize. This strong tendency of self-aggregation then triggers further dewetting effects of the respective polyether entities. Fingerlike morphologies are observed for Ch-lPEG(69), since the lPEG(69) entity is able to undergo crystallization after transfer onto the silicon substrate.

Modified polyether-sulfone membrane: a mini review.

Science.gov (United States)

Alenazi, Noof A; Hussein, Mahmoud A; Alamry, Khalid A; Asiri, Abdullah M

2017-01-01

Polyethersulfone has been widely used as a promising material in medical applications and waste-treatment membranes since it provides excellent mechanical and thermal properties. Hydrophobicity of polyethersulfone is considered one main disadvantage of using this material because hydrophobic surface causes biofouling effects to the membrane which is always thought to be a serious limitation to the use of polyethersulfone in membrane technology. Chemical modification to the material is a promising solution to this problem. More specifically surface modification is an excellent technique to introduce hydrophilic properties and functional groups to the polyethersulfone membrane surface. This review covers chemical modifications of the polyethersulfone and covers different methods used to enhance the hydrophilicity of polyethersulfone membrane. In particular, the addition of amino functional groups to polyethersulfone is used as a fundamental method either to introduce hydrophilic properties or introduce nanomaterials to the surface of polyethersulfone membrane. This work reviews also previous research reports explored the use of amino functionalized polyethersulfone with different nanomaterials to induce biological activity and reduce fouling effects of the fabricated membrane.

Isotopic shifts in chemical exchange systems. 1. Large isotope effects in the complexation of Na+ isotopes by macrocyclic polyethers

International Nuclear Information System (INIS)

Knoechel, A.; Wilken, R.D.

1981-01-01

The complexation of 24 Na + and 22 Na + by 18 of the most widely used macrocyclic polyethers (crown ethers and monocyclic and bicyclic aminopolyethers) has been investigated in view of possible equilibrium isotope shifts. Solvated salts and polyether complexes were distributed differently into two phases and isotope ratios determined in both phases. Chloroform/water systems were shown to be particularly suitable to the investigations allowing favorable distribution for Na + and 13 of the 18 polyethers employed. With crown ethers 24 Na + enrichment varied from nonsignficant values (for large crown ethers) up to 3.1 +- 0.4% (18-crown-6). In the case of bicyclic aminopolyethers, ligands with cages of optimum size to accommodate Na + showed 24 Na + enrichment between O (nonsignificant) (2.2/sub B/2./sub B/) and 5.2 +- 1.8% (2.2.1). In contrast, for 2.2.2. and its derivatives, being too large for Na + , 22 Na + enrichment varying from O (nonsignificant) (2.2.2.p) up to 5.4 +- 0.5% (2.2.2.) has been observed. These values are remarkably high. They are explained by different bonding in solvate structure and polyether complex by using the theoretical approach of Bigeleisen

Radiation-chemical synthesis of polypropylene fabrics with sulfonic acid functional groups

Energy Technology Data Exchange (ETDEWEB)

Cho, Hyun Kug; Park, Jung Soo; Han, Do Hung, E-mail: dhhan@yumail.ac.kr; Bondar, Iuliia, E-mail: juliavad@yahoo.co

2011-04-01

A sorption-active material carrying sulfonic acid groups was synthesized by the radiation-induced graft polymerization of styrene monomer onto the surface of non-woven polypropylene fabric, followed by sulfonation of the grafted polystyrene chains. The effect of the main experimental parameters (absorbed dose, monomer concentration, reaction time) on the styrene degree of grafting was investigated. The sulfonation process with 5% chlorosulfonic acid at room temperature was investigated in detail and the optimal sulfonation conditions for the samples with a medium degree of grafting (70-140%) were determined. Densities of 3.5-5 meq/g were obtained by applying those sorption-active PP fabrics with a sulfonic acid group.

Toltrazuril sulfone sodium salt: synthesis, analytical detection, and pharmacokinetics in the horse.

Science.gov (United States)

Dirikolu, L; Karpiesiuk, W; Lehner, A F; Tobin, T

2012-06-01

Toltrazuril sulfone (ponazuril) is a triazine-based antiprotozoal agent with clinical application in the treatment of equine protozoal myeloencephalomyelitis (EPM). In this study, we synthesized and determined the bioavailability of a sodium salt formulation of toltrazuril sulfone that can be used for the treatment and prophylaxis of EPM in horses. Toltrazuril sulfone sodium salt was rapidly absorbed, with a mean peak plasma concentration of 2400 ± 169 (SEM) ng/mL occurring at 8 h after oral-mucosal dosing and was about 56% bioavailable compared with the i.v. administration of toltrazuril sulfone in dimethylsulfoxide (DMSO). The relative bioavailability of toltrazuril sulfone suspended in water compared with toltrazuril sulfone sodium salt was 46%, indicating approximately 54% less oral bioavailability of this compound suspended in water. In this study, we also investigated whether this salt formulation of toltrazuril sulfone can be used as a feed additive formulation without significant reduction in oral bioavailability. Our results indicated that toltrazuril sulfone sodium salt is relatively well absorbed when administered with feed with a mean oral bioavailability of 52%. Based on these data, repeated oral administration of toltrazuril sulfone sodium salt with or without feed will yield effective plasma and cerebrospinal fluid (CSF) concentrations of toltrazuril sulfone for the treatment and prophylaxis of EPM and other protozoal diseases of horses and other species. As such, toltrazuril sulfone sodium salt has the potential to be used as feed additive formulations for both the treatment and prophylaxis of EPM and various other apicomplexan diseases. © 2011 Blackwell Publishing Ltd.

Preparation and study of novel poly(sulfone-ester-amide)s

Energy Technology Data Exchange (ETDEWEB)

Bruma, M. [Institute of Macromolecular Chemistry, Isai (Romania)], Mercer, F. [Raychem Corporation, Menlo Park, CA (United States); Gronewald, S. [Southwest Texas State Univ., San Marcos, TX (United States)] [and others

1995-12-31

A series of novel poly(ester-amide)s containing sulfone groups in the main chain have been prepared and compared with related polymers which do not have sulfone bridges. Incorporation of sulfone moieties into the polymer backbone improved the solubility of these polymers without significant loss of their high thermal stability, and provided a large {open_quotes}window{close_quotes} between T{sub g} and decomposition temperature. Solutions of poly(sulfone-ester-amide)s in NMP have been cast into flexible films, having low dielectric constant. The synthesis and characterization of these new polymers will be presented.

Pseudomacrocyclic effect in extraction processes of metal salts by polyethers from nitric acid solutions

International Nuclear Information System (INIS)

Yakshin, V.V.; Vilkova, O.M.; Kotlyar, S.A.; Kamalov, G.L.

1997-01-01

Comparison of macrocyclic (ME) and pseudmacrocyclic effects (PME), originating by conduct of the metal salt extraction processes (Cs, Sr, In, Zr, Cd, etc) from nitric acid solutions through linear and cyclic polyethers, containing 5 or 6 atoms of ether oxygen and having close molecular masses (290-360), is carried out. It is shown that ordinary ethers practically do not extract the studied metals from nitric acid solutions. By transfer from linear polyethers to their macrocyclic analogs the ME impact is expressed clearly enough: the separation coefficient value grows by tens and hundred times. At the some time the PME role in the extraction processes of metal nitrates through crown-ethers with alkyl and groups is expressed less clearly

Tailoring the toughness and CTE of high temperature bisphenol E cyanate ester (BECy resin

Directory of Open Access Journals (Sweden)

M. Thunga

2014-05-01

Full Text Available The objective of the present work is to enhancing the toughness and minimizing the CTE of a special class of bisphenol E cyanate ester (BECy resin by blending it with a thermoplastic toughening agent. Poly(ether sulfone was chosen as a high temperature resistant thermoplastic resin to enhance the thermo-mechanical properties of BECy. The influence of poly(ether sulfone/BECy blend composition on the morphology and phase behavior was studied using scanning electron microscopy and dynamic mechanical analysis. The mechanical properties of the blends were evaluated by flexural tests, which demonstrated significant enhancement in the material’s toughness with an increase in PES concentration from 0 to 15 wt%. The coefficient of thermal expansion of pure BECy was reduced from 61 to 48 ppm/°C in the blends with PES, emphasizing the multi-functional benefits of PES as a toughening agent in BECy.

Poly(ether amide) segmented block copolymers with adipicacid based tetra amide segments

NARCIS (Netherlands)

Biemond, G.J.E.; Feijen, Jan; Gaymans, R.J.

2007-01-01

Poly(tetramethylene oxide)-based poly(ether ester amide)s with monodisperse tetraamide segments were synthesized. The tetraamide segment was based on adipic acid, terephthalic acid, and hexamethylenediamine. The synthesis method of the copolymers and the influence of the tetraamide concentration,

The Continuing Saga of the Marine Polyether Biotoxins

Science.gov (United States)

Nicolaou, K. C.; Frederick, Michael O.; Aversa, Robert J.

2009-01-01

Lead-in Brevetoxin B emerged from the sea and into the laboratories of Nakanishi and Clardy who, in 1981, reported its magnificent and unprecedented structure. With its ladder-like fused polyether molecular architecture, potent toxicity, and fascinating voltage-sensitive sodium channel-based mechanism of action, it immediately captured the imagination of chemists around the world. Their synthetic escapades resulted in numerous new synthetic methods and strategies for the construction of cyclic ethers, and culminated in several impressive total syntheses of this imposing molecule and some of its equally challenging siblings that followed. Indeed, many more brevetoxin-type marine polyethers have been reported since 1981 with maitotoxin being not only the most complex and most toxic of the class, but also the largest non-polymeric natural product known to date. In this article, we begin with a brief history of these biotoxins and the phenomena that led to their isolation and highlight their biological properties and mechanism of action. We then review the chemical synthesis endeavors so far published in this long running saga, placing particular emphasis on the new synthetic methods and technologies discovered, developed and applied to their total syntheses over the last few decades. Finally, we conclude with a discussion of the, as yet unfinished, story of maitotoxin, and project into the future of this fascinating area of research. PMID:18763702

Proton exchange membranes from sulfonated polyetheretherketone and sulfonated polyethersulfone-cardo blends: Conductivity, water sorption and permeation properties

International Nuclear Information System (INIS)

Li, Yongli; Nguyen, Quang Trong; Schaetzel, Pierre; Lixon-Buquet, Camille; Colasse, Laurent; Ratieuville, Vincent

2013-01-01

Five blend membranes were prepared by solvent evaporation from solutions of the synthesized sulfonated polyetheretherketone (SPEEK) and sulfonated polyethersulfone-cardo (SPESc). Their ion exchange capacity and degree of sulfonation determined by acid–base titration and by thermogravimetric analysis were consistent. The blends glass transition behavior obtained by differential scanning calorimetry suggests that the two sulfonated polymers are compatible in the whole composition range. The values of the activation energy for proton transport determined by conductivity measurements on the SPEEK-based blend membranes were in the range of 13–34 kJ mol −1 , which suggest a mixed transport mechanism that involves both proton jumps on ionic sites and water of hydration and diffusion of proton–water complex in hydrophilic domains. The water vapor sorption in the membranes exhibits sigmoid-shape isotherms which were well fitted by the “new dual mode sorption” model, and the fitted parameters values were successfully used to model the change in the water permeation flux with the upstream water activity using the first Fick's diffusion equation. The fast increase in the permeation flux beyond a critical value of activity (0.5) was owing to the exponential concentration-dependent diffusion coefficient. These modelings allowed us to show a strong increase in the limit diffusion coefficient of water and a decrease in the water-diffusion plasticization coefficient with the SPEEK content in the polymer blends

Study of cross-linking reactions induced by gamma rays in hybrid membranes of Bisphenol-A-Polysulfone and precipitated silica; Estudo da formacao de ligacoes cruzadas por irradiacao gama em membranas hibridas de Polissulfona Bisfenol-A e silica precipitada

Energy Technology Data Exchange (ETDEWEB)

Furtado Filho, Acacio Antonio M., E-mail: facacio@ctex.eb.br [Laboratorio de Quimica Militar, CTEx, Rio de Janeiro, RJ (Brazil); Gomes, Ailton de S.; Lopes, Lea; Benzi, Marcia R. [Instituto de Macromoleculas Professora Eloisa Mano, UFRJ, Rio de Janeiro, RJ (Brazil)

2011-07-01

In this work the bisphenol-A-polysulfone (PSF) was sulfonated using trimethyl silyl chlorosulfonate [(CH{sub 3}){sub 3}SiSO{sub 3}Cl] as a mild sulfonating agent in a homogeneous solution of dichloroethane. The sulfonation reaction was confirmed by acid-base titration and FTIR-spectroscopy analysis. The hybrid membranes were obtained by casting the sulfonated bisphenol-A-polysulfone (SPSF) and precipitated silica Tixosil{sup R} 333 solutions in N-N-dimethylacetamide. Cross-linking in the hybrid membranes was obtained by irradiation, with doses ranging from 5 to 30 kGy using gamma ray from a {sup 60}Co source. The water uptake and the swelling of the membranes were estimated by measuring the change in weight between dry and wet conditions. The conductivity of the membranes in acid form was measured with the ac impedance technique using a PGSTAT30 frequency response analyzer. The hybrid cross-linked membranes have conductivity close to 10-1 S.cm{sup -1} at 100% RH and 80 deg C. Electrochemical performances, thermo-mechanical stability and low cost make this cross-linked SPSF hybrid membrane an attractive material for fuel cells using a proton exchange membrane. (author)

Toward High-Performance Lithium-Sulfur Batteries: Upcycling of LDPE Plastic into Sulfonated Carbon Scaffold via Microwave-Promoted Sulfonation.

Science.gov (United States)

Kim, Patrick J; Fontecha, Harif D; Kim, Kyungho; Pol, Vilas G

2018-05-02

Lithium-sulfur batteries were intensively explored during the last few decades as next-generation batteries owing to their high energy density (2600 Wh kg -1 ) and effective cost benefit. However, systemic challenges, mainly associated with polysulfide shuttling effect and low Coulombic efficiency, plague the practical utilization of sulfur cathode electrodes in the battery market. To address the aforementioned issues, many approaches have been investigated by tailoring the surface characteristics and porosities of carbon scaffold. In this study, we first present an effective strategy of preparing porous sulfonated carbon (PSC) from low-density polyethylene (LDPE) plastic via microwave-promoted sulfonation. Microwave process not only boosts the sulfonation reaction of LDPE but also induces huge amounts of pores within the sulfonated LDPE plastic. When a PSC layer was utilized as an interlayer in lithium-sulfur batteries, the sulfur cathode delivered an improved capacity of 776 mAh g -1 at 0.5C and an excellent cycle retention of 79% over 200 cycles. These are mainly attributed to two materialistic benefits of PSC: (a) porous structure with high surface area and (b) negatively charged conductive scaffold. These two characteristics not only facilitate the improved electrochemical kinetics but also effectively block the diffusion of polysulfides via Coulomb interaction.

Direct catalytic olefination of alcohols with sulfones.

Science.gov (United States)

Srimani, Dipankar; Leitus, Gregory; Ben-David, Yehoshoa; Milstein, David

2014-10-06

The synthesis of terminal, as well as internal, olefins was achieved by the one-step olefination of alcohols with sulfones catalyzed by a ruthenium pincer complex. Furthermore, performing the reaction with dimethyl sulfone under mild hydrogen pressure provides a direct route for the replacement of alcohol hydroxy groups by methyl groups in one step. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene polymer, chloro-sulfonated. 177.2210... as Components of Articles Intended for Repeated Use § 177.2210 Ethylene polymer, chloro-sulfonated. Ethylene polymer, chlorosulfonated as identified in this section may be safely used as an article or...

Anaerobic degradation of linear alkylbenzene sulfonate

DEFF Research Database (Denmark)

Mogensen, Anders Skibsted; Haagensen, Frank; Ahring, Birgitte Kiær

2003-01-01

Linear alkylbenzene sulfonate (LAS) found in wastewater is removed in the wastewater treatment facilities by sorption and aerobic biodegradation. The anaerobic digestion of sewage sludge has not been shown to contribute to the removal. The concentration of LAS based on dry matter typically...... increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C...

SEPARATION OF OCTYLPHENOL POLYETHER ALCOHOLS SURFACTANTS BY CAPILLARY COLUMN SFC AND HPLC

Science.gov (United States)

Separation of nonionic octylphenol polyether alcohols (OPA) by supercritical fluid chromatography (SFC) and HPLC is described. Using a density programming and a 50-μm i.d. capillary column, a total of 18 group oligomers was separated. The effects of the operating parameters, such...

The Setting Time of Polyether Impression Materials after Contact with Conventional and Experimental Gingival Margin Displacement Agents.

Science.gov (United States)

Nowakowska, Danuta; Raszewski, Zbigniew; Ziętek, Marek; Saczko, Jolanta; Kulbacka, Julita; Więckiewicz, Włodzimierz

2018-02-01

The compatibility of chemical gingival margin displacement agents with polyether impression materials has not been determined. The aim of this study was to evaluate the setting time of polyether impression elastomers after contact with conventional and experimental gingival displacement agents. The study compared the setting time of two polyether impression materials: medium body (Impregum Penta Soft) and light body (Impregum Garant L DuoSoft) after contact with 10 gingival displacement agents, including 5 conventional astringents (10%, 20%, and 25% aluminum chloride, 25% aluminum sulfate, and 15.5% ferric sulfate) and 5 experimental adrenergics (0.1% and 0.01% HCl-epinephrine, 0.05% HCl-tetrahydrozoline, 0.05% HCl-oxymetazoline, and 10% HCl-phenylephrine). As many as 120 specimens (60 light body and 60 medium body) were mixed with 20 μl of each of 10 gingival displacement agents, and the time to achieve maximum viscosity was measured with a viscometer. The setting times of these specimens were compared with the control group of 12 specimens, which were polymerized without contact with the displacement agents. The experiments were performed in two environments: 23°C and 37°C (± 0.1°C). Individual and average polymerization time compatibility indices (PTCI) were calculated. Data were analyzed by 2-way ANOVA (α = 0.05). The evaluated chemical displacement agents from both groups changed the setting time of light- and medium-body PE. The negative individual PTCI values achieved astringent (20% aluminum chloride) with two PE in both temperature environments. The average PTCI values of the experimental displacement agents at laboratory and intraoral temperatures were significantly higher than the conventional agents. The present findings suggest that experimental retraction agents can be recommended clinically as gingival margin displacement agents with minimal effects on the setting time of medium- and light-body polyether impression materials; however, direct

Polyimide-polyether mixed conductors as switchable materials for electrochromic devices

Energy Technology Data Exchange (ETDEWEB)

Michot, C; Baril, D; Armand, M [Laboratoire d` Ionique et d` Electrochimie du Solide, ENSEEG, Institut National Polytechnique de Grenoble, Saint-Martin d` Heres (France)

1995-12-01

A new family of redox-active polymers have been obtained by polycondensation of {alpha},{omega}-diamino oligopolyethers with various aromatic tetracarboxylic acid anhydrides. The polyether blocks retain the usual cation co-ordination ability leading to solid-state ionic conduction while the relatively large electron affinity of the bis-imide moieties formed in the block polymers allows the reversible formation of stable radical anions ({sup -} and {sup 2-}) in the range 2-2.6 V vs. Li. Either slow-scan or microelectrode voltammetry indicate that the totality of the redox centres in such materials are readily accessible for all polyether spacer lengths tested (6-22 ether fragments), suggesting both a fast electron-exchange mechanism between anion radicals and a tendency for self assembly (stacking) of the planar aromatic groups. When increasing the number of atoms in the aromatic ring, the peak separation became smaller (benzene>naphthalene>perylene), resulting ultimately in simultaneous 2-electrons injection. These materials, due to the high coloration efficiency of the reduced state and their ready processability in thin films are excellent candidate for the realisation of laminated solid-state electrochromic devices

Thermal stability and electrical conductivity in polyethers-molybdenum disulfide nanocomposites

International Nuclear Information System (INIS)

Mirabal, N.; Aguirre, P.; Santa Ana, M.A.; Benavente, E.; Gonzalez, Guillermo

2003-01-01

The intercalation of poly(ethylene oxide) (PEO), into molybdenum disulfide, like that of other electron pair donors, leads to mixed ionic-electronic conductors. At room temperature, intercalates show electrical and lithium-ion conductivities better than MoS 2 and bulk PEO composites, respectively. However, these products are known to be sensitive to temperature; indeed, in the range 80-100 deg. C an irreversible decrease of the electrical conductivity is observed. In order to investigate these features, the thermal behavior of a series of polyethers of different molecular weights (poly(ethylene glycol) (Mw 3400) and PEO with Mw in the range 10 4 -4x10 6 , pure and intercalated in MoS 2 , (Li x (MoS 2 )(polyether) y with x∼0.1 and y=1.1-1.5), was comparatively analyzed. Furthermore, the effect of thermal treatment of the sample on the electrical conductivity was studied for one of the intercalated products. Results indicate that irreversible changes, detected by both loss of weight and a significant conductivity lowering, are occurring in the range from about 100 deg. C to a temperature near to the decomposition point of the organic phase at about 350 deg. C

Improvement of the ionic conductivity for amorphous polyether electrolytes using supercritical CO2 treatment technology

International Nuclear Information System (INIS)

Kwak, Gun-Ho; Tominaga, Yoichi; Asai, Shigeo; Sumita, Masao

2003-01-01

The influence of the supercritical carbon dioxide (scCO 2 ) on ionic conductivity for polyether electrolytes based on oligo(oxyethylene glycol) methacrylate with lithium triflate, LiCF 3 SO 3 , has been investigated. In particular, the present research is a first attempt to improve an ion transport behavior of the polyether electrolytes using scCO 2 treatment technique. Consequently, the ionic conductivity of scCO 2 treated samples at room temperature was more than ten times elevated by the scCO 2 treatment under the condition of 10 MPa and 40 deg. C. From the Raman spectroscopy, decrease of aggregate ions and increase of free ions for the scCO 2 treated samples have been observed

Study of domain structure in segmented polyether polyurethaneureas by PAT

International Nuclear Information System (INIS)

Yin Chuanyuan; Xu Weizheng; Gu Qingchao

1990-01-01

The domain structure of segmented polyether polyurethaneureas is investigated by means of positron annihilation technique, small angle X-ray scattering and differential scanning calorimetry. The experimental results show that the decrease of domain volume and free volume results from the increase of hard segment contents, and that the increase of domain volume and free volume results from the increase of molecular weight of soft segments

High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation

DEFF Research Database (Denmark)

Dimzon, Ian Ken; Trier, Xenia; Frömel, Tobias

2016-01-01

High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid o......-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health. Graphical Abstract ᅟ....

Thermochemical stability of Soviet macroporous sulfonated cation-exchangers

Energy Technology Data Exchange (ETDEWEB)

Rukhlyada, N.N.; Plotnikova, V.P.; Roginskaya, B.S.; Znamenskii, Yu.P.; Zavodovskaya, A.S.; Dobrova, E.I.

1988-10-20

The purpose of this work was to study the influence of macroporosity on the thermochemical stability of sulfonated cation-exchangers. The investigations were carried out on commercial macroporous sulfonated cation-exchangers based on styrene-divinylbenzene copolymers. Study of the thermochemical stability of macroporous sulfonated cation-exchangers in dilute hydrogen peroxide solutions showed that the type of macroporosity has virtually no influence on their stability. The determining factor in thermal stability of macroporous cation-exchangers, as of the gel type, is the degree of cross-linking of the polymer matrix. The capacity loss of macroporous cation-exchangers during oxidative thermolysis is caused by destruction of the macromolecular skeleton and elution of fragments of polar chains containing sulfo groups into the solution.

A low perfusion rate microreactor for the continous monitoring of enzyme characteristics: applications for glucose oxidase.

NARCIS (Netherlands)

Posthuma-Trumpie, G.A.; Venema, K.; Berkel, van W.J.H.; Korf, J.

2007-01-01

This report describes a versatile and robust microreactor for bioactive proteins physically immobilized on a polyether sulfone filter. The potential of the reactor is illustrated with glucose oxidase immobilized on a filter with a cut-off value of 30 kDa. A flow-injection system was used to deliver

A low perfusion rate microreactor for continuous monitoring of enzyme characteristics : application to glucose oxidase

NARCIS (Netherlands)

Posthuma-Trumpie, G. A.; Venema, K.; van Berkel, W. J. H.; Korf, J.

This report describes a versatile and robust microreactor for bioactive proteins physically immobilized on a polyether sulfone filter. The potential of the reactor is illustrated with glucose oxidase immobilized on a filter with a cut-off value of 30 kDa. A flow-injection system was used to deliver

Highly selective Ba2+ separations with acyclic, lipophilic di-[N-(X)sulfonyl carbamoyl] polyethers.

Science.gov (United States)

Elshani, Sadik; Chun, Sangki; Amiri-Eliasi, Bijan; Bartsch, Richard A

2005-01-14

New lipophilic acyclic polyethers with two N-(X)sulfonyl carbamoyl groups of "tunable" acidity exhibit remarkable selectivity for Ba2+ over other alkaline earth metal ions in competitive solvent extraction and transport across polymer inclusion membranes.

Hydroxyl-substituted ladder polyethers via selective tandem epoxidation/cyclization sequence.

Science.gov (United States)

Czabaniuk, Lara C; Jamison, Timothy F

2015-02-20

A new and highly selective method for the synthesis of hydroxyl-substituted tetrahydropyrans is described. This method utilizes titanium(IV) isopropoxide and diethyl tartrate to perform a diastereoselective epoxidation followed by in situ epoxide activation and highly selective endo-cyclization to form the desired tetrahydropyran ring. The HIJ ring fragment of the marine ladder polyether yessotoxin was synthesized using this two-stage tactic that proceeds with high efficiency and excellent regioselectivity.

Polymer-filler interactions in polyether based thermoplastic polyureathane/silica nanocomposites

OpenAIRE

Heinz, Özge; Heinz, Ozge

2013-01-01

Thermoplastic polyurethaneureas (TPU) are a unique class of materials that are used in a broad range of applications due to their tailorable chemistry and morphology that allow engineering materials with targeted properties. The central theme of this dissertation is to develop an understanding on polymer-filler interfacial interactions and related reinforcing mechanism of silica nanoparticles in polyether based TPU/silica nanocomposites. Prior to our investigation on nanocomposite materials, ...

Radiation-induced crosslinking of poly(styrene–butadiene–styrene) block copolymers and their sulfonation

Energy Technology Data Exchange (ETDEWEB)

Lee, Sun-Young [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of); Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Song, Ju-Myung; Sohn, Joon-Yong [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of); Shul, Yong-Gun [Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Shin, Junhwa, E-mail: shinj@kaeri.re.kr [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of)

2013-12-01

Highlights: • The c-SBS films were prepared using a gamma ray or electron beam. • The crosslinking degree of the c-SBS films were increased with the irradiation dose. • The prepared c-SBS films were sulfonated with various concentration of CSA. • The sulfonation of the c-SBS film is largely dependent on the concentration of CSA. • The sulfonation process is progressed from the surface to the inner part of c-SBS film. -- Abstract: Several crosslinked poly(styrene–butadiene–styrene) (c-SBS) block copolymer films were prepared using a gamma ray or electron beam with various irradiation doses and the prepared c-SBS film was then subjected to sulfonation using a chlorosulfonic acid (CSA) solution to introduce a sulfonic acid group. To estimate the degree of crosslinking, the gel fractions and FT-IR spectra of the c-SBS films were used and the results indicate that the degree of crosslinking is increased with an increase in the radiation dose. The surface morphology and mechanical property of the c-SBS films were observed using SEM and UTM instruments, respectively. The sulfonated c-SBS films were investigated by measuring the ion exchange capacity (IEC) and by observing the cross-sectional distribution patterns of sulfonic acid group using an SEM-EDX instrument. The IEC and SEM-EDX studies indicate that the sulfonated c-SBS membranes can be successfully prepared through the radiation crosslinking of the SBS film and the subsequent sulfonation with a diluted CSA solution.

UV-Surface Treatment of Fungal Resistant Polyether Polyurethane Film-Induced Growth of Entomopathogenic Fungi.

Science.gov (United States)

Lando, Gabriela Albara; Marconatto, Letícia; Kessler, Felipe; Lopes, William; Schrank, Augusto; Vainstein, Marilene Henning; Weibel, Daniel Eduardo

2017-07-18

Synthetic polymers are the cause of some major environmental impacts due to their low degradation rates. Polyurethanes (PU) are widely used synthetic polymers, and their growing use in industry has produced an increase in plastic waste. A commercial polyether-based thermoplastic PU with hydrolytic stability and fungus resistance was only attacked by an entomopathogenic fungus, Metarhiziumanisopliae , when the films were pre-treated with Ultraviolet (UV) irradiation in the presence of reactive atmospheres. Water contact angle, Fourier transform infrared spectroscopy in attenuated total reflection mode (FTIR-ATR), scanning electron microscopy (SEM), and profilometer measurements were mainly used for analysis. Permanent hydrophilic PU films were produced by the UV-assisted treatments. Pristine polyether PU films incubated for 10, 30, and 60 days did not show any indication of fungal growth. On the contrary, when using oxygen in the UV pre-treatment a layer of fungi spores covered the sample, indicating a great adherence of the microorganisms to the polymer. However, if acrylic acid vapors were used during the UV pre-treatment, a visible attack by the entomopathogenic fungi was observed. SEM and FTIR-ATR data showed clear evidence of fungal development: growth and ramifications of hyphae on the polymer surface with the increase in UV pre-treatment time and fungus incubation time. The results indicated that the simple UV surface activation process has proven to be a promising alternative for polyether PU waste management.

UV-Surface Treatment of Fungal Resistant Polyether Polyurethane Film-Induced Growth of Entomopathogenic Fungi

Directory of Open Access Journals (Sweden)

Gabriela Albara Lando

2017-07-01

Full Text Available Synthetic polymers are the cause of some major environmental impacts due to their low degradation rates. Polyurethanes (PU are widely used synthetic polymers, and their growing use in industry has produced an increase in plastic waste. A commercial polyether-based thermoplastic PU with hydrolytic stability and fungus resistance was only attacked by an entomopathogenic fungus, Metarhiziumanisopliae, when the films were pre-treated with Ultraviolet (UV irradiation in the presence of reactive atmospheres. Water contact angle, Fourier transform infrared spectroscopy in attenuated total reflection mode (FTIR-ATR, scanning electron microscopy (SEM, and profilometer measurements were mainly used for analysis. Permanent hydrophilic PU films were produced by the UV-assisted treatments. Pristine polyether PU films incubated for 10, 30, and 60 days did not show any indication of fungal growth. On the contrary, when using oxygen in the UV pre-treatment a layer of fungi spores covered the sample, indicating a great adherence of the microorganisms to the polymer. However, if acrylic acid vapors were used during the UV pre-treatment, a visible attack by the entomopathogenic fungi was observed. SEM and FTIR-ATR data showed clear evidence of fungal development: growth and ramifications of hyphae on the polymer surface with the increase in UV pre-treatment time and fungus incubation time. The results indicated that the simple UV surface activation process has proven to be a promising alternative for polyether PU waste management.

Organic-inorganic hybrid polymer electrolytes based on polyether diamine, alkoxysilane, and trichlorotriazine: Synthesis, characterization, and electrochemical applications

Science.gov (United States)

Saikia, Diganta; Wu, Cheng-Gang; Fang, Jason; Tsai, Li-Duan; Kao, Hsien-Ming

2014-12-01

A new type of highly conductive organic-inorganic hybrid polymer electrolytes has been synthesized by the reaction of poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether), 2,4,6-trichloro-1,3,5-triazine and alkoxysilane precursor 3-(glycidyloxypropyl)trimethoxysilane, followed by doping of LiClO4. The 13C and 29Si solid-sate NMR results confirm the successful synthesis of the organic-inorganic hybrid structure. The solid hybrid electrolyte thus obtained exhibits a maximum ionic conductivity of 1.6 × 10-4 S cm-1 at 30 °C, which is the highest among the organic-inorganic hybrid electrolytes. The hybrid electrolytes are electrochemically stable up to 4.2 V. The prototype electrochromic device with such a solid hybrid electrolyte demonstrates a good coloration efficiency value of 183 cm2 C-1 with a cycle life over 200 cycles. For the lithium-ion battery test, the salt free solid hybrid membrane is swelled with a LiPF6-containing electrolyte solution to reach an acceptable ionic conductivity value of 6.5 × 10-3 S cm-1 at 30 °C. The battery cell carries an initial discharge capacity of 100 mAh g-1 at 0.2C-rate and a coulombic efficiency of about 95% up to 30 cycles without the sign of cell failure. The present organic-inorganic hybrid electrolytes hold promise for applications in electrochromic devices and lithium ion batteries.

Oil recovery with vinyl sulfonic acid-acrylamide copolymers

Energy Technology Data Exchange (ETDEWEB)

Norton, C.J.; Falk, D.O.

1973-12-18

An aqueous polymer flood containing sulfomethylated alkali metal vinyl sulfonate-acrylamide copolymers was proposed for use in secondary or tertiary enhanced oil recovery. The sulfonate groups on the copolymers sustain the viscosity of the flood in the presence of brine and lime. Injection of the copolymer solution into a waterflooded Berea core, produced 30.5 percent of the residual oil. It is preferred that the copolymers are partially hydrolyzed.

The importance of orientation in proton transport of a polymer film based on an oriented self-organized columnar liquid-crystalline polyether

Energy Technology Data Exchange (ETDEWEB)

Tylkowski, Bartosz; Castelao, Nuria [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain); Giamberini, Marta, E-mail: marta.giamberini@urv.net [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain); Garcia-Valls, Ricard [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain); Reina, Jose Antonio [Departament de Quimica Analitica i Quimica Organica, Universitat Rovira i Virgili, Carrer Marcel.li Domingo s/n, E-43007, Tarragona (Spain); Gumi, Tania [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain)

2012-02-01

We prepared membranes based on a liquid-crystalline side-chain polyether obtained by chemical modification of commercial poly(epichlorohydrin) (PECH) with dendrons. This polymer exhibited a columnar structure, which could form an ion channel in the inner part. The columns were successfully oriented by taking advantage of surface interactions between the polymer and hydrophilic substrates, as confirmed by X-ray diffraction analysis (XRD), environmental scanning electron microscopy (ESEM) and optical microscopy between crossed polars (POM). Column orientation was found to be crucial for effective transport: the oriented membranes exhibited proton transport comparable to that of Nafion Registered-Sign N117 and no water uptake. An increase in sodium ion concentration in the feed phase suggested a proton/cation antiport. On the contrary, no proton transport was detected on unoriented membranes based on the same liquid-crystalline side-chain polyether or on unmodified PECH. - Highlights: Black-Right-Pointing-Pointer We prepared oriented membranes based on a liquid crystalline columnar polyether. Black-Right-Pointing-Pointer In this structure, the inner polyether chain could work as an ion channel. Black-Right-Pointing-Pointer We obtained membranes by casting a chloroform solution in the presence of water. Black-Right-Pointing-Pointer Membranes showed good proton permeability due to the presence of oriented channels.

The importance of orientation in proton transport of a polymer film based on an oriented self-organized columnar liquid-crystalline polyether

International Nuclear Information System (INIS)

Tylkowski, Bartosz; Castelao, Nuria; Giamberini, Marta; Garcia-Valls, Ricard; Reina, José Antonio; Gumí, Tània

2012-01-01

We prepared membranes based on a liquid-crystalline side-chain polyether obtained by chemical modification of commercial poly(epichlorohydrin) (PECH) with dendrons. This polymer exhibited a columnar structure, which could form an ion channel in the inner part. The columns were successfully oriented by taking advantage of surface interactions between the polymer and hydrophilic substrates, as confirmed by X-ray diffraction analysis (XRD), environmental scanning electron microscopy (ESEM) and optical microscopy between crossed polars (POM). Column orientation was found to be crucial for effective transport: the oriented membranes exhibited proton transport comparable to that of Nafion® N117 and no water uptake. An increase in sodium ion concentration in the feed phase suggested a proton/cation antiport. On the contrary, no proton transport was detected on unoriented membranes based on the same liquid-crystalline side-chain polyether or on unmodified PECH. - Highlights: ► We prepared oriented membranes based on a liquid crystalline columnar polyether. ► In this structure, the inner polyether chain could work as an ion channel. ► We obtained membranes by casting a chloroform solution in the presence of water. ► Membranes showed good proton permeability due to the presence of oriented channels.

Electrochemical detection of dopamine using water-soluble sulfonated graphene

International Nuclear Information System (INIS)

Li, Su-Juan; He, Jun-Zhi; Zhang, Meng-Jie; Zhang, Rong-Xia; Lv, Xia-Lei; Li, Shao-Hua; Pang, Huan

2013-01-01

Graphical abstract: DPV responses of dopamine (DA) at sulfonated graphene based glassy carbon electrode in the presence of ascorbic acid (AA) and uric acid (UA). The separation of the oxidation peak potentials for AA-DA, DA-UA and UA-AA was about 227 mV, 125 mV and 352 mV, which allowed selectively determining DA. -- Abstract: In the present study, a biosensor was prepared using the water-soluble sulfonated graphene with the aim of achieving the selective and sensitive determination of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA). The aromatic π–π stacking and electrostatic attraction between positively charged DA and negatively charged sulfonated graphene can accelerate the electron transfer whereas weakening AA and UA oxidation on the sulfonated graphene-modified electrode. Fourier transform infrared spectra (FTIR), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to characterize the successful synthesis of sulfonated graphene sheets. Differential pulse voltammetry was used for electrochemical detection, the separation of the oxidation peak potentials for AA-DA, DA-UA and UA-AA was about 227 mV, 125 mV and 352 mV, which allowed selectively determining DA. A broad linear range, low detection limit, along with good ability to suppress the background current from large excess ascorbic acid (AA) and uric acid (UA) were obtained. The as-prepared sulfonated graphene sheets exhibited superior performance over conventional negatively charged Nafion films, such as flexible film thickness, unique nanostructure, excellent anti-interference ability, high sensitivity and selectivity. The proposed method was used to detect DA in real hydrochloride injection sample, human urine and serum samples with satisfactory recovery results

Hexaaquamagnesium(II bis(d-camphor-10-sulfonate

Directory of Open Access Journals (Sweden)

Dejan Jeremić

2008-07-01

Full Text Available The structure of the title complex, [Mg(H2O6](C10H15O4S2, consists of regular octahedral [Mg(H2O6]2+ cations and d-camphor-10-sulfonate anions. A three-dimensional supramolecular architecture is formed via hydrogen-bond interactions [O—H...O = 2.723 (2–2.833 (2 Å] to give alternating layers of [Mg(H2O6]2+ cations and d-camphor-10-sulfonate anions. The title compound is isomorphous with the zinc, copper, cadmium and nickel analogues.

Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

NARCIS (Netherlands)

Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

2001-01-01

Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing

Ultrasonic irradiation to modify the functionalized bionanocomposite in sulfonated polybenzimidazole membrane for fuel cells applications and antibacterial activity.

Science.gov (United States)

Esmaeilzade, Banafshe; Esmaielzadeh, Sheida; Ahmadizadegan, Hashem

2018-04-01

In this article the new proton exchange membranes were prepared from sulfonated polybenzimidazole (s-PBI) and various amounts of sulfonated titania/cellulose nanohybrids (titania/cellulose-SO 3 H) via ultrasonic waves. The ultrasonic irradiation effectively changes the rheology and the glass transition temperature and the crystallinity of the composite polymer. Ultrasonic irradiation has a very strong mixing and dispersion effect, much stronger than conventional stirring, which can improve the dispersion of titania/cellulose-SO 3 H nanoparticles in the polymer matrix. The strong -SO 3 H/-SO 3 H interaction between s-PBI chains and titania/cellulose-SO 3 H hybrids leads to ionic cross-linking in the membrane structure, which increases both the thermal stability and methanol resistance of the membranes. After acid doping with phosphoric acid, s-PBI/titania/cellulose-SO 3 H nanocomposite membranes exhibit depressions on methanol permeability and enhancements on proton conductivity comparing to the pristine s-PBI membrane. The chemical structure of the functionlized titania was characterized with FTIR, and energy-dispersive X-ray. Imidazole and sulfonated groups on the surface of modified nanoparticles forming linkages with s-PBI chains, improved the compatibility between s-PBI and nanoparticles, and enhanced the mechanical strength of the prepared nanocomposite membranes. From SEM and TEM analysis could explain the homogeneous dispersion of titania/cellulose-SO 3 H in nanocomposite membranes. Moreover, the membranes exhibited excellent antibacterial activities against S. aureus and E. coli. A. Copyright © 2017 Elsevier B.V. All rights reserved.

Complexation of triptycene-derived macrotricyclic polyether with paraquat derivatives, diquat, and a 2,7-diazapyrenium salt: guest-induced conformational changes of the host.

Science.gov (United States)

Han, Ying; Cao, Jing; Li, Peng-Fei; Zong, Qian-Shou; Zhao, Jian-Min; Guo, Jia-Bin; Xiang, Jun-Feng; Chen, Chuan-Feng

2013-04-05

Complexation between a triptycene-derived macrotricyclic polyether containing two dibenzo-[30]-crown-10 cavities and different functionalized paraquat derivatives, diquat, and a 2,7-diazapyrenium salt in both solution and solid state was investigated in detail. It was found that depending on the guests with different terminal functional groups and structures, the macrotricyclic polyether could form 1:1 or 1:2 complexes with the guests in different complexation modes in solution and also in the solid state. Especially, the conformation of the macrotricyclic polyether was efficiently adjusted by the encapsulated guests, which was to some extent similar to substrate-induced fit of enzymes. Moreover, the binding and releasing of the guests in the complexes could be controlled by potassium ions.

Direct Olefination of Alcohols with Sulfones by Using Heterogeneous Platinum Catalysts.

Science.gov (United States)

Siddiki, S M A Hakim; Touchy, Abeda Sultana; Kon, Kenichi; Shimizu, Ken-Ichi

2016-04-18

Carbon-supported Pt nanoparticles (Pt/C) were found to be effective heterogeneous catalysts for the direct Julia olefination of alcohols in the presence of sulfones and KOtBu under oxidant-free conditions. Primary alcohols, including aryl, aliphatic, allyl, and heterocyclic alcohols, underwent olefination with dimethyl sulfone and aryl alkyl sulfones to give terminal and internal olefins, respectively. Secondary alcohols underwent methylenation with dimethyl sulfone. Under 2.5 bar H2, the same reaction system was effective for the transformation of alcohol OH groups to alkyl groups. Structural and mechanistic studies of the terminal olefination system suggested that Pt(0) sites on the Pt metal particles are responsible for the rate-limiting dehydrogenation of alcohols and that KOtBu may deprotonate the sulfone reagent. The Pt/C catalyst was reusable after the olefination, and this method showed a higher turnover number (TON) and a wider substrate scope than previously reported methods, which demonstrates the high catalytic efficiency of the present method. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Poly-ethers from Winogradskyella poriferorum: Antifouling potential, time-course study of production and natural abundance

KAUST Repository

Dash, Swagatika; Nogata, Yasuyuki; Zhou, Xiaojian; Zhang, Yifan; Xü , Ying; Guo, Xian Rong; Zhang, Xixiang; Qian, Peiyuan

2011-01-01

A sponge-associated bacterium, Winogradskyella poriferorum strain UST030701-295T was cultured up to 100l for extraction of antifouling bioactive compounds. Five poly-ethers were isolated and partially characterized based on nuclear magnetic

Physical ageing and molecular mobilities of sulfonated polysulfone for proton exchange membranes

Energy Technology Data Exchange (ETDEWEB)

Lixon Buquet, C. [LECAP EA 4528, Institute for Materials Research FED 4114, Universite de Rouen, Avenue de l' Universite BP 12, 76801 Saint Etienne du Rouvray (France); PBS Department, UMR 6270 CNRS, MPBM, FR 3038, Universite de Rouen, Boulevard Maurice de Broglie, 76821 Mont Saint Aignan Cedex (France); Hamonic, F.; Saiter, A. [LECAP EA 4528, Institute for Materials Research FED 4114, Universite de Rouen, Avenue de l' Universite BP 12, 76801 Saint Etienne du Rouvray (France); Dargent, E., E-mail: eric.dargent@univ-rouen.fr [LECAP EA 4528, Institute for Materials Research FED 4114, Universite de Rouen, Avenue de l' Universite BP 12, 76801 Saint Etienne du Rouvray (France); Langevin, D.; Nguyen, Q.T. [PBS Department, UMR 6270 CNRS, MPBM, FR 3038, Universite de Rouen, Boulevard Maurice de Broglie, 76821 Mont Saint Aignan Cedex (France)

2010-09-20

The thermal behaviour, the physical ageing and the amorphous phase dynamics of polysulfone (PSU) and sulfonated polysulfone (SPSU) are characterized by thermogravimetric analysis and temperature modulated differential scanning calorimetry. The sulfonic group introduction (the sulfonation degree is 70%) in the polymer implies a drastic decrease of the thermal decomposition temperature (220 and 517 {sup o}C for SPSU and PSU respectively) and a modification of calorimetric parameters (for SPSU, the heat capacity in the glassy state is lower and the glass transition temperature T{sub g} is higher than for PSU). In terms of molecular dynamics, the amorphous phase heterogeneities are greater and the cooperative rearranging region size at the glass transition temperature is smaller for SPSU than for PSU. Moreover, after a physical ageing process, the enthalpy recovery kinetic has slowed down by sulfonation. These results can be explained from the existence of sulfonic domains confining the amorphous phase domains.

Nitric Acid Dehydration Using Perfluoro Carboxylate and Mixed Sulfonate/Carboxylate Membranes

Energy Technology Data Exchange (ETDEWEB)

Ames, Richard L. [Colorado School of Mines, Golden, CO (United States)

2004-09-01

Perfluoro ionomer membranes are tetrafluoro ethylene-based materials with microheterogeneous structures consisting of a hydrophobic polymer backbone and a hydrophilic side-chain cluster region. Due to the ionomer cluster morphology, these films exhibit unique transport properties. Recent investigations with perfluoro sulfonate and perfluoro sulfonate/carboxylate composite polymers have demonstrated their value in the dehydration of nitric acid and they show potential as an alternative to conventional, energy intensive unit operations in the concentration of acid feeds. As a result, investigations were conducted to determine the feasibility of using pure perfluoro carboxylate and mixed perfluoro sulfonate/carboxylate films for the dehydration of nitric acid because of the speculation of improved water selectivity of the carboxylate pendant chain. During the first phase of these investigations the effort was focused on generating a thin, solution cast perfluoro carboxylate ionomer film, to evaluate the general, chemical and physical characteristics of the polymer, and to assess the material's aqueous transport performance (flux and nitrate separation efficiencies) in pervaporation and high-pressure environments. Results demonstrated that generating robust solution-cast films was difficult yet a number of membranes survived high trans-membrane pressures up to 700 psig. General characterization of the solution cast product showed reduced ion exchange capacities when compared with thicker, ''as received'' perfluoro carboxylate and similar sulfonate films. Small angle x-ray scattering analysis results suggested that the solution cast carboxylate films contained a small fraction of sulfonate terminated side-chains. Aqueous transport experimentation showed that permeate fluxes for both pure water and nitric acid were approximately two orders of magnitude smaller for the carboxylate solution cast membranes when compared to their sulfonate

Graft-crosslinked copolymers based on poly(arylene ether ketone)-gc-sulfonated poly(arylene ether sulfone) for PEMFC applications.

Science.gov (United States)

Zhang, Xuan; Hu, Zhaoxia; Luo, Linqiang; Chen, Shanshan; Liu, Jianmei; Chen, Shouwen; Wang, Lianjun

2011-07-15

Novel poly(arylene ether ketone) polymers with fluorophenyl pendants and phenoxide-terminated wholly sulfonated poly(arylene ether sulfone) oligomers are prepared via Ni(0)-catalyzed and nucleophilic polymerization, respectively, and subsequently used as starting materials to obtain graft-crosslinked membranes as polymer electrolyte membranes. The phenoxide-terminated sulfonated moieties are introduced as hydrophilic parts as well as crosslinking units. The chemical structure and morphology of the obtained membranes are confirmed by (1) H NMR and tapping-mode AFM. The properties required for fuel cell applications, including water uptake and dimensional change, as well as proton conductivity, are investigated. AFM results show a clear nanoscale phase-separation microstructure of the obtained membranes. The membranes show good dimensional stability and reasonably high proton conductivities under 30-90% relative humidity. The anisotropic proton conductivity ratios (σ(formula see text) ) of the membranes in water are in the range 0.65-0.92, and increase with an increase in hydrophilic block length. The results indicate that the graft-crosslinked membranes are promising candidates for applications as polymer electrolyte membranes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

Science.gov (United States)

Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

1992-01-01

Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

XPS investigations on the UV-laser ablation mechanism of poly(ether imide)

Energy Technology Data Exchange (ETDEWEB)

Wambach, J; Kunz, T; Schnyder, B; Koetz, R; Wokaun, A [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

UV-Laser ablated samples of poly(ether imide) [Kapton{sup TM}] were studied with small-spot XPS. Applying fluences above the threshold level (0.167 J/cm{sup 2}) resulted in the expected behaviour of a decline of both nitrogen and oxygen. Below the threshold level a hint for an altered ablation mechanism was found. (author) 1 fig., 5 refs.

On solvent extraction of metals by macrocyclic polyethers

International Nuclear Information System (INIS)

Ionov, V.P.

1984-01-01

The Ksub(γ) parameter characterizing effective ion charges in ionic associates of metal salts is suggested; these charges parallel with other factors determine the metals extraction by macrocyclic polyethers (crown-ethers). The dependence of metal extraction constant on the Ksub(γ) parameter is discussed. It is shown that the less effective cation charge of alkali metal ionic associates, the more probable its entering the crown-ether cavity. The synergetic crown-ethers extraction is bound as well with Ksub(γ) of metal salts. The differences in the cation extraction constants having the same ionic radius are explained with account of different values of Ksub(γ) parameters of these salts

Poly (ether ether ketone) derivatives: Synthetic route and characterization of nitrated and sulfonated polymers

International Nuclear Information System (INIS)

Conceicao, T.F.; Bertolino, J.R.; Barra, G.M.O.; Pires, A.T.N.

2009-01-01

Nitrated and sulfonated poly (ether ether ketone) [SNPEEK] samples were prepared through sulfonation of nitrated PEEK (NPEEK) at different temperatures resulting in polymers with distinct sulfonation degrees (SD). The sulfonation occurred preferentially in the hydroquinone segment even after 81% of this moiety had been nitrated. Sulfonation in the benzophenone moiety was achieved only in 16% of this segment at the reaction temperature of 80 deg. C. The substitution degree was obtained through the TG curves, and values were in agreement with 1 H NMR data when SD is much higher as ND (nitration degree). The highest SD obtained was 72%. Membranes of the sulfonated and nitrated PEEK (SNPEEK) were prepared by casting and showed good ductility depending on the substitution degree, with proton conductivity in the order of 10 -2 S cm -1 , an important characteristic in some applications, such as in fuel cells

Poly (ether ether ketone) derivatives: Synthetic route and characterization of nitrated and sulfonated polymers

Energy Technology Data Exchange (ETDEWEB)

Conceicao, T.F.; Bertolino, J.R. [Grupo de Estudo em Materiais Polimericos-Departamento de Quimica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil); Barra, G.M.O. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil); Pires, A.T.N. [Grupo de Estudo em Materiais Polimericos-Departamento de Quimica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil)], E-mail: alfredotiburcio@pq.cnpq.br

2009-03-01

Nitrated and sulfonated poly (ether ether ketone) [SNPEEK] samples were prepared through sulfonation of nitrated PEEK (NPEEK) at different temperatures resulting in polymers with distinct sulfonation degrees (SD). The sulfonation occurred preferentially in the hydroquinone segment even after 81% of this moiety had been nitrated. Sulfonation in the benzophenone moiety was achieved only in 16% of this segment at the reaction temperature of 80 deg. C. The substitution degree was obtained through the TG curves, and values were in agreement with {sup 1}H NMR data when SD is much higher as ND (nitration degree). The highest SD obtained was 72%. Membranes of the sulfonated and nitrated PEEK (SNPEEK) were prepared by casting and showed good ductility depending on the substitution degree, with proton conductivity in the order of 10{sup -2} S cm{sup -1}, an important characteristic in some applications, such as in fuel cells.

Uptake and utilization of sulfonic acids in the cyanobacterial strains Anabaena variabilis and Plectonema 73110

International Nuclear Information System (INIS)

Biedlingmaier, S.; Schmidt, A.

1987-01-01

Growth of several cyanobacteria was examined on ethane sulfonate and taurine as only sulfur source. Comparing two strains with differential utilization of sulfonic acids (Anabaena variabilis and Synechococcus 6301) demonstrated that actual growth was coupled to the presence of an active sulfonate transport system due to species specific properties and nutritional conditions. Sulfonate uptake in Anabaena variabilis was characterized by a pH optimum of 6.5, a structural specificity for sulfonates, missing Na + dependence, and phosphate stimulation. Radiolabeled ethane sulfonate and taurine was metabolized to products of normal sulfur metabolism. Also considerable amounts of 35 S-labeled volatiles (mercaptanes and sulfide) could be detected, suggesting a degradation mechanism via reduction to mercaptanes and cleavage of the C-S bond. (orig.)

Andrographolide sulfonate ameliorates experimental colitis in mice by inhibiting Th1/Th17 response.

Science.gov (United States)

Liu, Wen; Guo, Wenjie; Guo, Lele; Gu, Yanhong; Cai, Peifen; Xie, Ning; Yang, Xiaoling; Shu, Yongqian; Wu, Xuefeng; Sun, Yang; Xu, Qiang

2014-06-01

Inflammatory bowel disease (IBD) is a chronic, relapsing and remitting condition of inflammation involves overproduction of pro-inflammatory cytokines and excessive functions of inflammatory cells. However, current treatments for IBD may have potential adverse effects including steroid dependence, infections and lymphoma. Therefore new therapies for the treatment of IBD are desperately needed. In the present study, we aimed to examine the effect of andrographolide sulfonate, a water-soluble form of andrographolide (trade name: Xi-Yan-Ping Injection), on murine experimental colitis induced by 2, 4, 6-trinitrobenzene sulfonic acid (TNBS). Andrographolide sulfonate was administrated through intraperitoneal injection to mice with TNBS-induced colitis. TNBS-induced body weight loss, myeloperoxidase activity, shortening of the colon and colonic inflammation were significantly ameliorated by andrographolide sulfonate. Both the mRNA and protein levels of pro-inflammatory cytokines were reduced by andrographolide sulfonate administration. Moreover, andrographolide sulfonate markedly suppressed the activation of p38 mitogen-activated protein kinase as well as p65 subunit of nuclear factor-κB (NF-κB). Furthermore, CD4(+) T cell infiltration as well as the differentiation of Th1 (CD4(+)IFN-γ(+)) and Th17 (CD4(+)IL17A(+)) subset were inhibited by andrographolide sulfonate. In summary, these results suggest that andrographolide sulfonate ameliorated TNBS-induced colitis in mice through inhibiting Th1/Th17 response. Our study shows that water-soluble andrographolide sulfonate may represent a new therapeutic approach for treating gastrointestinal inflammatory disorders. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of poly-ether B on proteome and phosphoproteome expression in biofouling Balanus amphitrite cyprids

KAUST Repository

Dash, Swagatika; Chandramouli, Kondethimmanahalli; Zhang, Yu; Qian, Pei Yuan

2012-01-01

in recent years, although the mechanism by which they inhibit fouling is yet to be investigated. Poly-ether B has shown promise in the non-toxic inhibition of larval barnacle attachment. Hence, in this study, multiplex two-dimensional electrophoresis (2-DE

Sulfonated chitosan and dopamine based coatings for metallic implants in contact with blood.

Science.gov (United States)

Campelo, Clayton S; Chevallier, Pascale; Vaz, Juliana M; Vieira, Rodrigo S; Mantovani, Diego

2017-03-01

Thrombosis and calcification constitute the main clinical problems when blood-interacting devices are implanted in the body. Coatings with thin polymer layers represent an acknowledged strategy to modulate interactions between the material surface and the blood environment. To ensure the implant success, at short-term the coating should limit platelets adhesion and delay the clot formation, and at long-term it should delay the calcification process. Sulfonated chitosan, if compared to native chitosan, shows the unique ability to reduce proteins adsorption, decrease thrombogenic properties and limit calcification. In this work, stainless steel surfaces, commonly used for cardiovascular applications, were coated with sulfonated chitosan, by using dopamine and PEG as anchors, and the effect of these grafted surfaces on platelet adhesion, clot formation as well as on calcification were investigated. Surface characterization techniques evidenced that the coating formation was successful, and the sulfonated chitosan grafted sample exhibited a higher roughness and hydrophilicity, if compared to native chitosan one. Moreover, sulfonated surface limited platelet activation and the process of clot formation, thus confirming its high biological performances in blood. Calcium deposits were also lower on the sulfonated chitosan sample compared to the chitosan one, thus showing that calcification was minimal in presence of sulfonate groups. In conclusion, this sulfonated-modified surface has potential to be as blood-interacting material. Copyright © 2016. Published by Elsevier B.V.

Comparative study to evaluate the accuracy of polyether occlusal bite registration material and occlusal registration wax as a guide for occlusal reduction during tooth preparation

Directory of Open Access Journals (Sweden)

Niranjan Joshi

2013-01-01

Objective: The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. Materials and Methods: For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. Results: The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. Conclusion: The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.

Isopropyl Myristate-Modified Polyether-Urethane Coatings as Protective Barriers for Implantable Medical Devices

Science.gov (United States)

Roohpour, Nima; Wasikiewicz, Jaroslaw M.; Moshaverinia, Alireza; Paul, Deepen; Rehman, Ihtesham U.; Vadgama, Pankaj

2009-01-01

Polyurethane films have potential applications in medicine, especially for packaging implantable medical devices. Although polyether-urethanes have superior mechanical properties and are biocompatible, achieving water resistance is still a challenge. Polyether based polyurethanes with two different molecular weights (PTMO1000, PTMO2000) were prepared from 4,4’-diphenylmethane diisocyanate and poly(tetra-methylene oxide). Polymer films were introduced using different concentrations (0.5-10 wt %) of isopropyl myristate lipid (IPM) as a non-toxic modifying agent. The physical and mechanical properties of these polymers were characterised using physical and spectroscopy techniques (FTIR, Raman, DSC, DMA, tensile testing). Water contact angle and water uptake of the membranes as a function of IPM concentration was also determined accordingly. The FTIR and Raman data indicate that IPM is dispersed in polyurethane at ≤ 2wt% and thermal analysis confirmed this miscibility to be dependent on soft segment length. Modified polymers showed increased tensile strength and failure strain as well as reduced water uptake by up to 24% at 1-2 wt% IPM.

Isopropyl Myristate-Modified Polyether-Urethane Coatings as Protective Barriers for Implantable Medical Devices

Directory of Open Access Journals (Sweden)

Pankaj Vadgama

2009-06-01

Full Text Available Polyurethane films have potential applications in medicine, especially for packaging implantable medical devices. Although polyether-urethanes have superior mechanical properties and are biocompatible, achieving water resistance is still a challenge. Polyether based polyurethanes with two different molecular weights (PTMO1000, PTMO2000 were prepared from 4,4’-diphenylmethane diisocyanate and poly(tetra-methylene oxide. Polymer films were introduced using different concentrations (0.5-10 wt % of isopropyl myristate lipid (IPM as a non-toxic modifying agent. The physical and mechanical properties of these polymers were characterised using physical and spectroscopy techniques (FTIR, Raman, DSC, DMA, tensile testing. Water contact angle and water uptake of the membranes as a function of IPM concentration was also determined accordingly. The FTIR and Raman data indicate that IPM is dispersed in polyurethane at ≤ 2wt% and thermal analysis confirmed this miscibility to be dependent on soft segment length. Modified polymers showed increased tensile strength and failure strain as well as reduced water uptake by up to 24% at 1-2 wt% IPM.

Decoupling ion conductivity and fluid permeation through optimizing hydrophilic channel morphology

Energy Technology Data Exchange (ETDEWEB)

Chu, Peter Po-Jen, E-mail: pjchu@cc.ncu.edu.tw; Fang, Yu-Shin; Tseng, Yu-Chen [Department of Chemistry, National Central University, No. 300, Jhongda Rd., Jhongli City, Taoyuan County 32001, Taiwan (R.O.C.) (China)

2016-05-18

Approaches to improve membrane ion conductivity usually leads to higher degree of swelling, more serious fuel cross-over and often sacrificed membrane mechanical strength. Preserving all three main membrane properties is a tough challenge in searching high ion conducting fuel cell membrane. The long standing dilemma is resolved by decoupling ion conduction and fluid permeation property by creating optimized channel morphology using external electric field poling. Success of this approach is demonstrated in the proton conducting membrane composed of poly(ether sulfones) (PES) and sulfonated poly(ether ether ketone) (sPEEK, degree of sulfonation=50%) composites prepared under electric field poling condition. The external field enhanced the aromatic chain ordering from both sPEEK and PES and improved the miscibility. This induced interaction is conducive to the formation of more densely packed amorphous domains that eventually leads to preferentially ordered hydrophilic proton conducting channels having a average dimension (3 nm) smaller than that in generic sPEEK or Nafion. The narrower but more ordered channel displayed much lower methanol permeability (3.17×10{sup −7} cm{sup 2}/s), and lower swelling ratio (31.20%), while the conductivity (~10{sup −1} S/cm) is higher than that of Nafion, or sPEEK at higher (64%) degree of sulfonation. The composite is chemically stable and highly durable with improved membrane mechanical strength. Nearly 50% increase of DMFC power output is observed using this membrane, and the best power density is recorded at 155 mA/cm{sup 2} (80 °C, 1M Methanol).

SEC-MALDI-TOF mass spectral characterization of a hyperbranched polyether prepared via melt transetherification

NARCIS (Netherlands)

Jayakannan, M.; Dongen, van J.L.J.; Behera, G.Ch.; Ramakrishnan, S.

2002-01-01

An AB2 monomer, 1-(2-hydroxyethoxy)-3,5-bis-(methoxymethyl)-2,4,6-trimethylbenzene, was synthesized from mesitol and melt-polycondensed in the presence of an acid catalyst via a transetherification process at 145-150 °C to yield a soluble, moderately high molecular weight hyperbranched polyether.

Precursor Ion Scan Mode-Based Strategy for Fast Screening of Polyether Ionophores by Copper-Induced Gas-Phase Radical Fragmentation Reactions.

Science.gov (United States)

Crevelin, Eduardo J; Possato, Bruna; Lopes, João L C; Lopes, Norberto P; Crotti, Antônio E M

2017-04-04

The potential of copper(II) to induce gas-phase fragmentation reactions in macrotetrolides, a class of polyether ionophores produced by Streptomyces species, was investigated by accurate-mass electrospray tandem mass spectrometry (ESI-MS/MS). Copper(II)/copper(I) transition directly induced production of diagnostic acylium ions with m/z 199, 185, 181, and 167 from α-cleavages of [macrotetrolides + Cu] 2+ . A UPLC-ESI-MS/MS methodology based on the precursor ion scan of these acylium ions was developed and successfully used to identify isodinactin (1), trinactin (2), and tetranactin (3) in a crude extract of Streptomyces sp. AMC 23 in the precursor ion scan mode. In addition, copper(II) was also used to induce radical fragmentation reactions in the carboxylic acid polyether ionophore nigericin. The resulting product ions with m/z 755 and 585 helped to identify nigericin in a crude extract of Streptomyces sp. Eucal-26 by means of precursor ion scan experiments, demonstrating that copper-induced fragmentation reactions can potentially identify different classes of polyether ionophores rapidly and selectively.

Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite

Directory of Open Access Journals (Sweden)

Das G

2015-08-01

Full Text Available Gautam Das, Hyon Hee Yoon Department of Chemical and Biological Engineering, Gachon University, Seongnam, Gyeonggi-do, South Korea Abstract: An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 µA·cm-2·mM-1. The biosensor achieved a broad linear range of detection (0.12–12.3 mM with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection. Keywords: electrochemical deposition, sulfonated graphene oxide, urease

Cd(II and Pb(II complexes of the polyether ionophorous antibiotic salinomycin

Directory of Open Access Journals (Sweden)

Tanabe Makoto

2011-09-01

Full Text Available Abstract Background The natural polyether ionophorous antibiotics are used for the treatment of coccidiosis in poultry and ruminants. They are effective agents against infections caused by Gram-positive microorganisms. On the other hand, it was found that some of these compounds selectively bind lead(II ions in in vivo experiments, despite so far no Pb(II-containing compounds of defined composition have been isolated and characterized. To assess the potential of polyether ionophores as possible antidotes in the agriculture, a detailed study on their in vitro complexation with toxic metal ions is required. In the present paper we report for the first time the preparation and the structure elucidation of salinomycin complexes with ions of cadmium(II and lead(II. Results New metal(II complexes of the polyether ionophorous antibiotic salinomycin with Cd(II and Pb(II ions were prepared and structurally characterized by IR, FAB-MS and NMR techniques. The spectroscopic information and elemental analysis data reveal that sodium salinomycin (SalNa undergoes a reaction with heavy metal(II ions to form [Cd(Sal2(H2O2] (1 and [Pb(Sal(NO3] (2, respectively. Abstraction of sodium ions from the cavity of the antibiotic is occurring during the complexation reaction. Salinomycin coordinates with cadmium(II ions as a bidentate monoanionic ligand through the deprotonated carboxylic moiety and one of the hydroxyl groups to yield 1. Two salinomycin anions occupy the equatorial plane of the Cd(II center, while two water molecules take the axial positions of the inner coordination sphere of the metal(II cation. Complex 2 consists of monoanionic salinomycin acting in polydentate coordination mode in a molar ratio of 1: 1 to the metal ion with one nitrate ion for charge compensation. Conclusion The formation of the salinomycin heavy metal(II complexes indicates a possible antidote activity of the ligand in case of chronic/acute intoxications likely to occur in the stock

Cd(II) and Pb(II) complexes of the polyether ionophorous antibiotic salinomycin

Science.gov (United States)

2011-01-01

Background The natural polyether ionophorous antibiotics are used for the treatment of coccidiosis in poultry and ruminants. They are effective agents against infections caused by Gram-positive microorganisms. On the other hand, it was found that some of these compounds selectively bind lead(II) ions in in vivo experiments, despite so far no Pb(II)-containing compounds of defined composition have been isolated and characterized. To assess the potential of polyether ionophores as possible antidotes in the agriculture, a detailed study on their in vitro complexation with toxic metal ions is required. In the present paper we report for the first time the preparation and the structure elucidation of salinomycin complexes with ions of cadmium(II) and lead(II). Results New metal(II) complexes of the polyether ionophorous antibiotic salinomycin with Cd(II) and Pb(II) ions were prepared and structurally characterized by IR, FAB-MS and NMR techniques. The spectroscopic information and elemental analysis data reveal that sodium salinomycin (SalNa) undergoes a reaction with heavy metal(II) ions to form [Cd(Sal)2(H2O)2] (1) and [Pb(Sal)(NO3)] (2), respectively. Abstraction of sodium ions from the cavity of the antibiotic is occurring during the complexation reaction. Salinomycin coordinates with cadmium(II) ions as a bidentate monoanionic ligand through the deprotonated carboxylic moiety and one of the hydroxyl groups to yield 1. Two salinomycin anions occupy the equatorial plane of the Cd(II) center, while two water molecules take the axial positions of the inner coordination sphere of the metal(II) cation. Complex 2 consists of monoanionic salinomycin acting in polydentate coordination mode in a molar ratio of 1: 1 to the metal ion with one nitrate ion for charge compensation. Conclusion The formation of the salinomycin heavy metal(II) complexes indicates a possible antidote activity of the ligand in case of chronic/acute intoxications likely to occur in the stock farming

On the Importance of Purification of Sodium Polystyrene Sulfonate

OpenAIRE

Sen, Akhil K.; Roy, Sandip; Juvekar, Vinay A.

2012-01-01

Ion exchange is commonly employed for purification of sodium polystyrene sulfonate (NaPSS), a molecule widely used as a model polyelectrolyte. However, the present work demonstrates that the ion exchange process itself may introduce some extraneous species into NaPSS samples by two possible mechanisms: (i) chemical transformation of polystyrene sulfonic acid (HPSS), a relatively unstable intermediate formed during ion exchange and (ii) release of small amount of “condensed” acid from cationic...

Synthesis and properties of a novel sulfonated poly(arylene ether ketone sulfone) membrane with a high β-value for direct methanol fuel cell applications

International Nuclear Information System (INIS)

Xu, Jingmei; Ma, Li; Han, Hailan; Ni, Hongzhe; Wang, Zhe; Zhang, Huixuan

2014-01-01

Highlights: • Introduction of carboxyl groups into copolymers resulted in extensive hydrogen bond. • The C-SPAEKS membranes had obviously hydrophilic/hydrophobic phase separation. • The membranes showed low methanol permeability and high β values. • The membranes exhibited good thermal property and desirable mechanical performance. - Abstract: Sulfonated poly(arylene ether ketone sulfone) membranes containing carboxylic acid groups (C-SPAEKS) with different degrees of sulfonation were synthesized by the nucleophilic aromatic substitution reactions of 4-carboxylphenyl hydroquinone (4C-PH), bisphenol A, 3,3′-disulfonated 4,4′-dichlorodiphenyl sulfone, and 4,4′-difluorobenzophenone. The Fourier transform infrared and 1 H NMR analyses of C-SPAEKS revealed the presence of carboxylic acid groups in the C-SPAEKS membranes. The membranes exhibited a low swelling degree and methanol crossover level. The effects of different degrees of sulfonation on the water uptake, proton conductivity, and methanol permeability coefficient of the membranes were studied. The maximum proton conductivity of C-SPAEKS-80 membrane at room temperature was 0.069 S cm −1 , which was higher than that of Nafion ® 117 membrane. The methanol permeability coefficient of C-SPAEKS-80 membrane was 9.15 × 10 −7 cm 2 s −1 at 20 °C, much lower than that of Nafion 117 membrane (22.9 × 10 −7 cm 2 s −1 ). Furthermore, the carboxyl group-containing membranes exhibited a high β-value, further confirming that this series of membranes possess excellent comprehensive performance and can be applied in direct methanol fuel cells

Sulfonation and characterization of styrene-indene copolymers for the development of proton conducting polymer membranes

Directory of Open Access Journals (Sweden)

Cristiane M. Becker

2012-01-01

Full Text Available The aim of this work is to obtain polymer precursors based on styrene copolymers with distinct degrees of sulfonation, as an alternative material for fuel cell membranes. Acetyl sulfate was used to carry out the sulfonation and the performance of the polyelectrolyte was evaluated based on the content of acid polar groups incorporated into the macromolecular chain. Polymeric films were produced by blending the sulfonated styrene-indene copolymer with poly(vinylidene fluoride. The degree of sulfonation of the polymer was strongly affected by the sulfonation reaction parameters, with a direct impact on the ionic exchange capacity and the ionic conductivity of the sulfonated polymers and the membranes obtained from them. The films produced with the blends showed more suitable mechanical properties, although the conductivity of the membranes was still lower than that of commercially available membranes used in fuel cells.

Monensin, a polyether ionophore antibiotic, overcomes TRAIL resistance in glioma cells via endoplasmic reticulum stress, DR5 upregulation and c-FLIP downregulation.

Science.gov (United States)

Yoon, Mi Jin; Kang, You Jung; Kim, In Young; Kim, Eun Hee; Lee, Ju Ahn; Lim, Jun Hee; Kwon, Taeg Kyu; Choi, Kyeong Sook

2013-08-01

Tumor necrosis factor-related apoptosis-induced ligand (TRAIL) is preferentially cytotoxic to cancer cells over normal cells. However, many cancer cells, including malignant glioma cells, tend to be resistant to TRAIL. Monensin (a polyether ionophore antibiotic that is widely used in veterinary medicine) and salinomycin (a compound that is structurally related to monensin and shows cancer stem cell-inhibiting activity) are currently recognized as anticancer drug candidates. In this study, we show that monensin effectively sensitizes various glioma cells, but not normal astrocytes, to TRAIL-mediated apoptosis; this occurs at least partly via monensin-induced endoplasmic reticulum (ER) stress, CHOP-mediated DR5 upregulation and proteasome-mediated downregulation of c-FLIP. Interestingly, other polyether antibiotics, such as salinomycin, nigericin, narasin and lasalocid A, also stimulated TRAIL-mediated apoptosis in glioma cells via ER stress, CHOP-mediated DR5 upregulation and c-FLIP downregulation. Taken together, these results suggest that combined treatment of glioma cells with TRAIL and polyether ionophore antibiotics may offer an effective therapeutic strategy.

Inhibition of the anaerobic digestion process by linear alkylbenzene sulfonates

DEFF Research Database (Denmark)

Gavala, Hariklia N.; Ahring, Birgitte Kiær

2002-01-01

Linear Alkylbenzene Sulfonates (LAS) are the most widely used synthetic anionic surfactants. They are anthropogenic, toxic compounds and are found in the primary sludge generated in municipal wastewater treatment plants. Primary sludge is usually stabilized anaerobically and therefore it is impor......Linear Alkylbenzene Sulfonates (LAS) are the most widely used synthetic anionic surfactants. They are anthropogenic, toxic compounds and are found in the primary sludge generated in municipal wastewater treatment plants. Primary sludge is usually stabilized anaerobically and therefore...... it is important to investigate the effect of these xenobiotic compounds on an anaerobic environment. The inhibitory effect of Linear Alkylbenzene Sulfonates (LAS) on the acetogenic and methanogenic step of the anaerobic digestion process was studied. LAS inhibit both acetogenesis from propionate...

Copolymers of fluorinated polydienes and sulfonated polystyrene

Science.gov (United States)

Mays, Jimmy W [Knoxville, TN; Gido, Samuel P [Hadley, MA; Huang, Tianzi [Knoxville, TN; Hong, Kunlun [Knoxville, TN

2009-11-17

Copolymers of fluorinated polydienes and sulfonated polystyrene and their use in fuel cell membranes, batteries, breathable chemical-biological protective materials, and templates for sol-gel polymerization.

40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

Science.gov (United States)

2010-07-01

... solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment... POINT SOURCE CATEGORY SO3 Solvent and Vacuum Sulfonation Subcategory § 417.110 Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. The provisions of this subpart are...

Nanoscale Organic−Inorganic Hybrid Lubricants

KAUST Repository

Kim, Daniel

2011-03-15

Silica (SiO2) nanoparticles densely grafted with amphiphilic organic chains are used to create a family of organic-inorganic hybrid lubricants. Short sulfonate-functionalized alkylaryl chains covalently tethered to the particles form a dense corona brush that stabilizes them against aggregation. When these hybrid particles are dispersed in poly-α-olefin (PAO) oligomers, they form homogeneous nanocomposite fluids at both low and high particle loadings. By varying the volume fraction of the SiO2 nanostructures in the PAO nanocomposites, we show that exceptionally stable hybrid lubricants can be created and that their mechanical properties can be tuned to span the spectrum from simple liquids to complex gels. We further show that these hybrid lubricants simultaneously exhibit lower interfacial friction coefficients, enhanced wear and mechanical properties, and superior thermal stability in comparison with either PAO or its nanocomposites created at low nanoparticle loadings. Profilometry and energy dispersive X-ray spectroscopic analysis of the wear track show that the enhanced wear characteristics in PAO-SiO2 composite lubricants originate from two sources: localization of the SiO2 particles into the wear track and extension of the elastohydrodynamic lubrication regime to Sommerfeld numbers more than an order of magnitude larger than for PAO. © 2011 American Chemical Society.

Design, synthesis, and characterization of lightly sulfonated multigraft acrylate-based copolymer superelastomers

Energy Technology Data Exchange (ETDEWEB)

Misichronis, Konstantinos [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division; Wang, Weiyu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS); Cheng, Shiwang [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division; Wang, Yangyang [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS); Shrestha, Umesh [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry; Dadmun, Mark D. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division; Mays, Jimmy W. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division; Saito, Tomonori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division

2018-01-29

Multigraft copolymer superelastomers consisting of a poly(n-butyl acrylate) backbone and polystyrene side chains were synthesized and the viscoelastic properties of the non-sulfonated and sulfonated final materials were investigated using extensional rheology (SER3). The non-linear viscoelastic experiments revealed significantly increased true stresses (up to 10 times higher) after sulfonating only 2–3% of the copolymer while the materials maintained high elongation (<700%). The linear viscoelastic experiments showed that the storage and loss modulus are increased by sulfonation and that the copolymers can be readily tuned and further improved by increasing the number of branching points and the molecular weight of the backbone. Here, in this way, we show that by tuning not only the molecular characteristics of the multigraft copolymers but also their architecture and chemical interaction, we can acquire thermoplastic superelastomer materials with desired viscoelastic properties.

Sulfonated polyimides containing triphenylphosphine oxide for proton exchange membranes

Energy Technology Data Exchange (ETDEWEB)

Mandal, Arun Kumar; Bera, Debaditya; Banerjee, Susanta, E-mail: susanta@matsc.iitkgp.ernet.in

2016-09-15

A series of sulfonated co-polyimides (co-SPI) were prepared by one pot polycondensation reaction of a combination of diamines namely; 4,4′-diaminostilbene-2,2′-disulfonic acid (DSDSA) and prepared non-sulfonated diamine (DATPPO) containing triphenylphosphine oxide with 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA). All these soluble co-SPI gave flexible membranes with high thermal stability and showed good mechanical property. Transmission electron microscopy (TEM) analysis revealed the microphase separated morphology with well-dispersed hydrophilic (cluster size in the range of 5–55 nm) domains. The co-SPI membranes showed high oxidative and hydrolytic stability with higher proton conductivity. All these co-SPI membranes exhibited low water uptake and swelling ratio. The co-SPI membrane TPPO-60 (60% degree of sulfonation) with IEC{sub W} = 1.84 mequiv g{sup −1} showed high proton conductivity (99 mS cm{sup −1} at 80 °C and 107 mS cm{sup −1} at 90 °C) in water with high oxidative (20 h) and hydrolytic stability (only 5% degradation in 24 h). - Highlights: • Triphenylphosphine oxide containing sulfonated polyimides (SPIs) was synthesized. • The SPIs showed good oxidative and hydrolytic stability and high proton conductivity. • TEM analysis revealed well separated morphology of the SPIs.

Tissue engineering of bovine articular cartilage within porous poly(ether ester) copolymer scaffolds with different structures

NARCIS (Netherlands)

Mahmood, Tahir A.; Shastri, V. Prasad; van Blitterswijk, Clemens; Langer, Robert; Riesle, J.U.

2005-01-01

The potential of porous poly(ether ester) scaffolds made from poly(ethylene glycol) terephthalate: poly(butylene terephthalate) (PEGT:PBT) block copolymers produced by various methods to enable cartilaginous tissue formation in vitro was studied. Scaffolds were fabricated by two different processes:

Ultra-deep desulfurization via reactive adsorption on peroxophosphomolybdate/agarose hybrids.

Science.gov (United States)

Xu, Jian; Li, Huacheng; Wang, Shengtian; Luo, Fang; Liu, Yunyu; Wang, Xiaohong; Jiang, Zijiang

2014-09-01

A catalyst system composed of peroxophosphomolybdates as catalytic center and agarose as matrix material had been designed. The [C16H33N(CH3)3]3[PO4{MoO(O2)2}4]/agarose (C16PMo(O2)2/agarose) hybrid was found to be active for oxidation desulfurization (ODS) of dibenzothiophene (DBT) or real fuel into corresponding sulfone by H2O2 as an oxidant, while the sulfur content could be reduced to 5ppm. The higher activity comes from its components including [PO4{MoO(O2)2}4] catalytic sites, the hydrophobic quaternary ammonium cation affinity to low polarity substrates, and agarose matrix affinity to H2O2 and sulfone. During the oxidative reaction, the mass transfer resistance between H2O2 and organic sulfurs could be decreased and the reaction rate could increase by the assistance of agarose and hydrophobic tails of [C16H33N(CH3)3]3[PO4{MoO(O2)2}4]. Meanwhile, the oxidative products could be adsorbed by agarose matrix to give clean fuel avoiding the post-treatment. In addition, the hybrid was easily regenerated to be reused. Copyright © 2014 Elsevier Ltd. All rights reserved.

Characterization of a poly(ether urethane)-based controlled release membrane system for delivery of ketoprofen

International Nuclear Information System (INIS)

Macocinschi, Doina; Filip, Daniela; Vlad, Stelian; Oprea, Ana Maria; Gafitanu, Carmen Anatolia

2012-01-01

Highlights: ► Ketoprofen incorporation in poly(ether urethane) microporous membrane. ► Moisture sorption properties of as-cast membrane. ► Drug release mechanisms in function of pH and composition of membranes. - Abstract: A poly(ether urethane) based on polytetrahydrofuran containing hydroxypropyl cellulose for biomedical applications was tested for its biocompatibility. Ketoprofen was incorporated (3% and 6%) in the polyurethane matrix as an anti-inflammatory drug. Kinetic and drug release mechanisms were studied. The pore size and pore size distribution of the polyurethane membranes were investigated by scanning electron microscopy. Surface tension characteristics as well as moisture sorption properties such as diffusion coefficients and equilibrium moisture contents of the membrane material were studied. It was found that kinetics and release mechanisms are in function of medium pH, composition of polymer–drug system, pore morphology and pore size distribution. Prolonged nature of release of ketoprofen is assured by low amount of drug in polyurethane membrane and physiological pH.

Mechanism and Stereochemistry of Polyketide Chain Elongation and Methyl Group Epimerization in Polyether Biosynthesis.

Science.gov (United States)

Xie, Xinqiang; Garg, Ashish; Khosla, Chaitan; Cane, David E

2017-03-01

The polyketide synthases responsible for the biosynthesis of the polyether antibiotics nanchangmycin (1) and salinomycin (4) harbor a number of redox-inactive ketoreductase (KR 0 ) domains that are implicated in the generation of C2-epimerized (2S)-2-methyl-3-ketoacyl-ACP intermediates. Evidence that the natural substrate for the polyether KR 0 domains is, as predicted, a (2R)-2-methyl-3-ketoacyl-ACP intermediate, came from a newly developed coupled ketosynthase (KS)-ketoreductase (KR) assay that established that the decarboxylative condensation of methylmalonyl-CoA with S-propionyl-N-acetylcysteamine catalyzed by the Nan[KS1][AT1] didomain from module 1 of the nanchangmycin synthase generates exclusively the corresponding (2R)-2-methyl-3-ketopentanoyl-ACP (7a) product. In tandem equilibrium isotope exchange experiments, incubation of [2- 2 H]-(2R,3S)-2-methyl-3-hydroxypentanoyl-ACP (6a) with redox-active, epimerase-inactive EryKR6 from module 6 of the 6-deoxyerythronolide B synthase and catalytic quantities of NADP + in the presence of redox-inactive, recombinant NanKR1 0 or NanKR5 0 , from modules 1 and 5 of the nanchangmycin synthase, or recombinant SalKR7 0 from module 7 of the salinomycin synthase, resulted in first-order, time-dependent washout of deuterium from 6a. Control experiments confirmed that this washout was due to KR 0 -catalyzed isotope exchange of the reversibly generated, transiently formed oxidation product [2- 2 H]-(2R)-2-methyl-3-ketopentanoyl-ACP (7a), consistent with the proposed epimerase activity of each of the KR 0 domains. Although they belong to the superfamily of short chain dehydrogenase-reductases, the epimerase-active KR 0 domains from polyether synthases lack one or both residues of the conserved Tyr-Ser dyad that has previously been implicated in KR-catalyzed epimerizations.

Salinomycin and Other Polyether Ionophores Are a New Class of Antiscarring Agent*

Science.gov (United States)

Woeller, Collynn F.; O'Loughlin, Charles W.; Roztocil, Elisa; Feldon, Steven E.; Phipps, Richard P.

2015-01-01

Although scarring is a component of wound healing, excessive scar formation is a debilitating condition that results in pain, loss of tissue function, and even death. Many tissues, including the lungs, heart, skin, and eyes, can develop excessive scar tissue as a result of tissue injury, chronic inflammation, or autoimmune disease. Unfortunately, there are few, if any, effective treatments to prevent excess scarring, and new treatment strategies are needed. Using HEK293FT cells stably transfected with a TGFβ-dependent luciferase reporter, we performed a small molecule screen to identify novel compounds with antiscarring activity. We discovered that the polyether ionophore salinomycin potently inhibited the formation of scar-forming myofibroblasts. Salinomycin (250 nm) blocked TGFβ-dependent expression of the cardinal myofibroblast products α smooth muscle actin, calponin, and collagen in primary human fibroblasts without causing cell death. Salinomycin blocked phosphorylation and activation of TAK1 and p38, two proteins fundamentally involved in signaling myofibroblast and scar formation. Expression of constitutively active mitogen activated kinase kinase 6, which activates p38 MAPK, attenuated the ability of salinomycin to block myofibroblast formation, demonstrating that salinomycin targets the p38 kinase pathway to disrupt TGFβ signaling. These data identify salinomycin and other polyether ionophores as novel potential antiscarring therapeutics. PMID:25538236

Complexes of macrocyclic dibenzo-18-crown-6 polyether with nitrates of some rare earths

International Nuclear Information System (INIS)

Gren', A.I.; Zakhariya, N.F.; Vityuk, N.V.; Kalishevich, V.S.

1984-01-01

The purpose of the investigation is to obtain and study the structure of complexes of macrocyclic polyether dibenzo-18-crown-6(D-18-C-6) with REE nitrates (Ln, Pr, Nd, Er). Synthesis has been realized by mixing the solutions 2 mol Ln(NO 3 ) 3 and 2 mmol D-18-C-6 into 30-50 ml acetonitrile and boiling during 40-60 minutes. Study on the prepared compounds by means of UV- and IR-spectroscopy proved formation of D-18-C-6 complexes with lanthanide nitrates-Ln(NO 3 ) 3 D-18-C-6. Based on studying IR-spectra a conclusion is made on deformation of D-18-C-6 structure under complexing. Distortion of the ring structure of macrocyclic polyether manifests itself in increase of CH 2 -O-CH 2 bond lengths with simultaneous reduction of four other types of bonds C 6 H 5 -O-CH 2 . Synthesized complexes are stated to have different solubility in acetonitrile which increases in the La 3 ) 3 xD-18-C-6 is noted

Two-step sulfonation process for the conversion of polymer fibers to carbon fibers

Science.gov (United States)

Barton, Bryan E.; Patton, Jasson T.; Hukkanen, Eric J.; Bernius, Mark T.

2017-11-14

Disclosed herein are processes for preparing carbon fibers, comprising: sulfonating a polymer fiber with a sulfonating agent that is fuming sulfuric acid, sulfuric acid, chlorosulfonic acid, or a combination thereof; treating the sulfonated polymer with a heated solvent, wherein the temperature of the heated solvent is at least 95.degree. C.; and carbonizing the resulting product by heating it to a temperature of 501-3000.degree. C. Carbon fibers prepared according to these methods are also disclosed herein.

Lithiated and sulphonated poly(ether ether ketone) solid state electrolyte films for supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Chiu, K.-F.; Su, S.-H., E-mail: minimono42@gmail.com

2013-10-01

Poly(ether ether ketone) (PEEK) films have been synthesised and used as solid-state electrolytes for supercapacitors. In order to increase their ion conductivity, the PEEK films were sulphonated by sulphuric acid, and various amounts of LiClO{sub 4} were added. The solid-state electrolyte films were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The ionic conductivities of the electrolyte films were analysed by performing electrochemical impedance spectroscopy. The obtained electrolyte films can be sandwiched or directly coated on activated carbon electrodes to form solid-state supercapacitors. The electrochemical characteristics of these supercapacitors were investigated by performing cyclic voltammetry and charge–discharge tests. Under an optimal content of LiClO{sub 4}, the supercapacitor can provide a capacitance as high as 190 F/g. After 1000 cycles, the supercapacitors show almost no capacitance fading, indicating high stability of the solid-state electrolyte films. - Highlights: • Poly(ether ether ketone) (PEEK) films have been used as solid-state electrolytes. • LiClO4 addition can efficiently improve the ionic conductivity. • Supercapacitors using PEEK electrolyte films deliver high capacitance.

Lithiated and sulphonated poly(ether ether ketone) solid state electrolyte films for supercapacitors

International Nuclear Information System (INIS)

Chiu, K.-F.; Su, S.-H.

2013-01-01

Poly(ether ether ketone) (PEEK) films have been synthesised and used as solid-state electrolytes for supercapacitors. In order to increase their ion conductivity, the PEEK films were sulphonated by sulphuric acid, and various amounts of LiClO 4 were added. The solid-state electrolyte films were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The ionic conductivities of the electrolyte films were analysed by performing electrochemical impedance spectroscopy. The obtained electrolyte films can be sandwiched or directly coated on activated carbon electrodes to form solid-state supercapacitors. The electrochemical characteristics of these supercapacitors were investigated by performing cyclic voltammetry and charge–discharge tests. Under an optimal content of LiClO 4 , the supercapacitor can provide a capacitance as high as 190 F/g. After 1000 cycles, the supercapacitors show almost no capacitance fading, indicating high stability of the solid-state electrolyte films. - Highlights: • Poly(ether ether ketone) (PEEK) films have been used as solid-state electrolytes. • LiClO4 addition can efficiently improve the ionic conductivity. • Supercapacitors using PEEK electrolyte films deliver high capacitance

Amphiphilic poly(ether ester amide) multiblock copolymers as biodegradable matrices for the controlled release of proteins

NARCIS (Netherlands)

Bezemer, J.M.; Oude Weme, P.; Grijpma, Dirk W.; Dijkstra, Pieter J.; van Blitterswijk, Clemens; Feijen, Jan

2000-01-01

Amphiphilic poly(ether ester amide) (PEEA) multiblock copolymers were synthesized by polycondensation in the melt from hydrophilic poly(ethylene glycol) (PEG), 1,4-dihydroxybutane and short bisester-bisamide blocks. These amide blocks were prepared by reaction of 1,4-diaminobutane with dimethyl

Biofilm formed from organic-inorganic hybrid tri-ureasil PPO for transdermal drug delivery system

Energy Technology Data Exchange (ETDEWEB)

Molina, Eduardo F.; Jesus, Natana Aparecida; Oliveira, Pollyana Francielli; Furtado, Ricardo A.; Tavares, Denise Crispim, E-mail: eduardo.molina@unifran.edu.br [Universidade de Franca (UNIFRAN), SP (Brazil)

2016-07-01

Full text: In this work we evaluated the viability of the tri-ureasil PPO hybrid as biofilm forming for release of active substances such as lignans. The samples were characterized by X-ray diffraction (XRD) and infrared (FTIR). The swelling degree and the influence of the catalyst on time of formation of a hybrid biofilm were evaluated. The cytotoxicity of the materials were evaluated using the XTT colorimetric assay where GM07492A strain was treated with different concentrations of the hybrid. The time of film formation depends on the quantity of the catalyst used in the synthesis. By varying the catalyst quantity during the synthesis, a good flexible film can be obtained, which is easy to be coated on the skin surface and in situ formed a very thin and comfortable film with an aesthetical appearance. Moreover, the hybrid films were colorless and transparent. The toxicity/viability of all samples has also been studied using normal human cells for future applications. The hybrid matrices did not significantly reduce cell viability, demonstrating that siloxane-polyether materials were biocompatible. All the materials presenting a amorphous structure (XRD) and the characteristic bands of vibrations (FTIR) of the polymer chain do not change after incorporation of lignans. (author)

Biofilm formed from organic-inorganic hybrid tri-ureasil PPO for transdermal drug delivery system

International Nuclear Information System (INIS)

Molina, Eduardo F.; Jesus, Natana Aparecida; Oliveira, Pollyana Francielli; Furtado, Ricardo A.; Tavares, Denise Crispim

2016-01-01

Full text: In this work we evaluated the viability of the tri-ureasil PPO hybrid as biofilm forming for release of active substances such as lignans. The samples were characterized by X-ray diffraction (XRD) and infrared (FTIR). The swelling degree and the influence of the catalyst on time of formation of a hybrid biofilm were evaluated. The cytotoxicity of the materials were evaluated using the XTT colorimetric assay where GM07492A strain was treated with different concentrations of the hybrid. The time of film formation depends on the quantity of the catalyst used in the synthesis. By varying the catalyst quantity during the synthesis, a good flexible film can be obtained, which is easy to be coated on the skin surface and in situ formed a very thin and comfortable film with an aesthetical appearance. Moreover, the hybrid films were colorless and transparent. The toxicity/viability of all samples has also been studied using normal human cells for future applications. The hybrid matrices did not significantly reduce cell viability, demonstrating that siloxane-polyether materials were biocompatible. All the materials presenting a amorphous structure (XRD) and the characteristic bands of vibrations (FTIR) of the polymer chain do not change after incorporation of lignans. (author)

Potential contact and intraocular lenses based on hydrophilic/hydrophobic sulfonated syndiotactic polystyrene membranes

Directory of Open Access Journals (Sweden)

Simona Zuppolini

2017-10-01

Full Text Available Crystalline films of syndiotactic polystyrene (s-PS, a commercially available thermoplastic polymer, having a highly hydrophilic amorphous phase, were achieved by using a mild solid-state sulfonation procedure. Despite the used mild process conditions, an easy and uniform sulfonation of the phenyl rings of the amorphous phase is obtained. The crystallinity of the polymer was not affect by the sulfonation degree (S, at least at S less than 20%, and the obtained polymer films show the nanoporous crystalline form of s-PS. As widely reported in literature, the nanoporous nature of the polymer crystalline phase gives to these materials the ability to absorb and release organic molecules of appropriate size and polarity. This property, coupled to transparency, makes these materials potentially useful intraocular lens (IOLs and contact lens applications. Sulfonation procedure and sulfonated film samples characterization by using wide-angle X-ray diffraction (WAXD, Fourier-transform infrared (FTIR and ultraviolet-visible (UV-vis spectroscopy techniques and water sorption tests were reported. Furthermore, the biocompatibility study demonstrated no cytotoxicity and appropriate cell interaction properties for the specific applications.

Novel amide polar-embedded reversed-phase column for the fast liquid chromatography-tandem mass spectrometry method to determine polyether ionophores in environmental waters.

Science.gov (United States)

Herrero, P; Borrull, F; Pocurull, E; Marcé, R M

2012-11-09

A fast chromatographic method has been developed that takes less than 5 min per run to determine five polyether ionophores with a novel amide polar-embedded reversed-phase column coupled to a triple quadrupole mass spectrometer. A comparison between Oasis HLB and Oasis MAX sorbents for the solid-phase extraction was done. Oasis HLB sorbent gave recoveries close to 90% and the repeatability (%RSD, 25-100 ng/L, n=3) of the method was less than 7% for all compounds in all matrices. The presence of polyether ionophores in environmental waters such as river water and sewage was investigated. Monensin and narasin were frequently determined in influent and effluent sewage at concentrations from 10 ng/L to 47 ng/L in influents and from 6 ng/L to 34 ng/L in effluents. In river waters, polyether ionophores were not detected in any sample. Copyright © 2012 Elsevier B.V. All rights reserved.

Novel high-performance nanocomposite proton exchange membranes based on poly (ether sulfone)

Energy Technology Data Exchange (ETDEWEB)

Hasani-Sadrabadi, Mohammad Mahdi [Polymer Engineering Department, Amirkabir University of Technology, Tehran (Iran); Biomedical Engineering Department, Amirkabir University of Technology, Tehran (Iran); Dashtimoghadam, Erfan; Ghaffarian, Seyed Reza [Polymer Engineering Department, Amirkabir University of Technology, Tehran (Iran); Hasani Sadrabadi, Mohammad Hossein [Faculty of Social and Economics Science, Alzahra University, Tehran (Iran); Heidari, Mahdi [Graduate School of Management and Economics, Sharif University of Technology, Tehran (Iran); Moaddel, Homayoun [Department of Materials Science and Engineering, University of California, Los Angeles, CA (United States)

2010-01-15

In the present research, proton exchange membranes based on partially sulfonated poly (ether sulfone) (S-PES) with various degrees of sulfonation were synthesized. It was found that the increasing of sulfonation degree up to 40% results in the enhancement of water uptake, ion exchange capacity and proton conductivity properties of the prepared membranes to 28.1%, 1.59 meq g{sup -1}, and 0.145 S cm{sup -1}, respectively. Afterwards, nanocomposite membranes based on S-PES (at the predetermined optimum sulfonation degree) containing various loading weights of organically treated montmorillonite (OMMT) were prepared via the solution intercalation technique. X-ray diffraction patterns revealed the exfoliated structure of OMMT in the macromolecular matrices. The S-PES nanocomposite membrane with 3.0 wt% of OMMT content showed the maximum selectivity parameter of about 520,000 S s cm{sup -3} which is related to the high conductivity of 0.051 S cm{sup -1} and low methanol permeability of 9.8 x 10{sup -8} cm{sup 2} s{sup -1}. Furthermore, single cell DMFC fuel cell performance test with 4 molar methanol concentration showed a high power density (131 mW cm{sup -2}) of the nanocomposite membrane at the optimum composition (40% of sulfonation and 3.0 wt% of OMMT loading) compared to the Nafion {sup registered} 117 membrane (114 mW cm{sup -2}). Manufactured nanocomposite membranes thanks to their high selectivity, ease of preparation and low cost could be suggested as the ideal candidate for the direct methanol fuel cell applications. (author)

Particle size effects of sulfonated graphene supported Pt nanoparticles on ethanol electrooxidation

International Nuclear Information System (INIS)

Sun, Chia-Liang; Tang, Jui-Shiang; Brazeau, Nicolas; Wu, Jhing-Jhou; Ntais, Spyridon; Yin, Chung-Wei; Chou, Hung-Lung; Baranova, Elena A.

2015-01-01

Highlights: • Pt colloidal nanoparticles with five mean diameters are synthesized. • Size-selected Pt nanoparticles are loaded on sulfonated graphene (sG). • Sulfonic acid functional groups atop graphene donate charge to Pt. • Pt-sG catalysts are used for ethanol oxidation reaction (EOR). • Pt-sG(2.5 nm) has the highest peak current density in EOR. - Abstract: Fuel cells are promising alternative in automobile and stationary power generation. Direct ethanol fuel cells (DEFCs) offer significant advantages due to the non-toxicity and renewability of ethanol as well as its high power density. Development of the efficient catalysts for ethanol oxidation reaction (EOR) has attracted great attention and represents one of the major challenges in electrocatalysis. Graphene, one-atom thick nanocarbon materials, has attracted much attention recently in a variety of applications. The sulfonation of graphene is able to make it hydrophilic, which enhances its dispersibility in aqueous solvents. Furthermore, sulfonation increases the adsorption and uniform distribution of the Pt nanoparticles, which increases both the electrocatalytic activity and the durability. In this study, theoretical calculations demonstrated that the sulfonate functional group can donate charge to Pt, enhanced the adsorption energy of Pt, and then reduce the adsorption energy of CO on Pt. Then experimentally five kinds of Pt/sulfonated-graphene (Pt/sG) catalysts were synthesized via the control of pH values during the preparation of five-selected colloidal nanoparticles. Among all catalysts, Pt-sG(2.5 nm) has the highest peak current density in EOR

18-Crown-6-polyether complexing with iodine

International Nuclear Information System (INIS)

Borovikov, Yu.Ya.

1988-01-01

Using the methods of dielectrometry, conductometry, calorimetry, UV, NMR and IR spectroscopy, 18-Crown-6-polyether complexing with iodine in chlorobenzene, benzotrifluoride, 1,2 dichloroethane is investigated. At the first stage external complexes (1) of the composition 1:1 (dipole momentum μ=7 D) is formed, which gradually regroups into internal complex (2) of the compositon 4:1. The time of 1 transition into 2 is inversely proportional to dielectric permeability of the medium. Enthalpy of 1 formation is close to 8.3 kcal/mol, which is 2,5 times higher than in cyclohexane solutions. Complex 1 is molecular, 2 is salt-like. Formation enthalpy of complex 2 of the components is not high, in dichlaroethane it is centrally symmetric and nonpolar, in chlorobenzene and benzotrifluoride-highly polar. In solid phase complex of the composition 1:2 is formed

18-Crown-6-polyether complexing with iodine

Energy Technology Data Exchange (ETDEWEB)

Borovikov, Yu Ya [AN Ukrainskoj SSR, Kiev (Ukrainian SSR). Inst. Organicheskoj Khimii

1988-01-01

Using the methods of dielectrometry, conductometry, calorimetry, UV, NMR and IR spectroscopy, 18-Crown-6-polyether complexing with iodine in chlorobenzene, benzotrifluoride, 1,2 dichloroethane is investigated. At the first stage external complexes (1) of the composition 1:1 (dipole momentum {mu}=7 D) is formed, which gradually regroups into internal complex (2) of the compositon 4:1. The time of 1 transition into 2 is inversely proportional to dielectric permeability of the medium. Enthalpy of 1 formation is close to 8.3 kcal/mol, which is 2,5 times higher than in cyclohexane solutions. Complex 1 is molecular, 2 is salt-like. Formation enthalpy of complex 2 of the components is not high, in dichlaroethane it is centrally symmetric and nonpolar, in chlorobenzene and benzotrifluoride-highly polar. In solid phase complex of the composition 1:2 is formed.

Comparative study to evaluate the accuracy of polyether occlusal bite registration material and occlusal registration wax as a guide for occlusal reduction during tooth preparation.

Science.gov (United States)

Joshi, Niranjan; Shetty, Sridhar N; Prasad, Krishna D

2013-01-01

The use of different materials and techniques has been studied to decide the safest quantum of reduction of the occlusal surfaces. However, these methods provide limited information as to the actual amount of reduction with limitations in accuracy, accessibility and complexity. The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.

40 CFR 721.2565 - Alkylated sulfonated diphenyl oxide, alkali and amine salts.

Science.gov (United States)

2010-07-01

..., alkali and amine salts. 721.2565 Section 721.2565 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.2565 Alkylated sulfonated diphenyl oxide, alkali and... substances identified as alkylated sulfonated diphenyl oxide, alkali salt (PMN P-93-352) and alkylated...

Derivatives of phenyl tribromomethyl sulfone as novel compounds with potential pesticidal activity

Directory of Open Access Journals (Sweden)

Krzysztof M. Borys

2012-02-01

Full Text Available A halogenmethylsulfonyl moiety is incorporated in numerous active herbicides and fungicides. The synthesis of tribromomethyl phenyl sulfone derivatives as novel potential pesticides is reported. The title sulfone was obtained by following three different synthetic routes, starting from 4-chlorothiophenol or 4-halogenphenyl methyl sulfone. Products of its subsequent nitration were subjected to the SNAr reactions with ammonia, amines, hydrazines and phenolates to give 2-nitroaniline, 2-nitrophenylhydrazine and diphenyl ether derivatives. Reduction of the nitro group of 4-tribromomethylsulfonyl-2-nitroaniline yielded the corresponding o-phenylenediamine substrate for preparation of structurally varied benzimidazoles.

Hydrogen storage by functionalised Poly(ether ether ketone)

Energy Technology Data Exchange (ETDEWEB)

Pedicini, R.; Giacoppo, G.; Carbone, A.; Passalacqua, E. [CNR-ITAE, Messina (Italy). Inst. for Advanced Energy Technologies

2010-07-01

In this work a functionalised polymer was studied as potential material for hydrogen storage in solid state. A Poly(ether ether ketone) (PEEK) matrix was modified by a manganese oxide in situ formation. Here we report the functionalisation process and the preliminary results on hydrogen storage capability of the synthesised polymer. The polymer was characterized by Scanning Electron Microscopy, X-ray diffraction, Transmission Electron Microscopy and Gravimetric Hydrogen Adsorption measurements. In the functionalised PEEK, morphological changes occur as a function of oxide precursor concentration and reaction time. Promising results by gravimetric measurements were obtained with a hydrogen sorption of 0.24%wt/wt at 50 C and 60 bar, moreover, reversibility hydrogen adsorption and desorption in a wide range of both temperature and pressure was confirmed. (orig.)

Hydrophilicity improvement of polyethersulfone membranes by grafting methacrylic acid with γ-ray irradiation

International Nuclear Information System (INIS)

Li Jing; Hou Zhengchi; Xie Leidong; Zhang Fengying; Deng Bo

2005-01-01

Grafting methyacrylic acid onto poly(ether sulfone) membranes was realized by means of simultaneous irradiation in liquids. The modified membranes with different grafting ratios were obtained by changing the concentration of methyacrylic acid. It was shown that the grafting ratio increased lineally as the monomer concentration was less than 10% and hydrophilicity of the membranes was improved with increasing grafting ratios. (authors)

Derivatization of enolic OH of piroxicam: a comparative study on esters and sulfonates

Energy Technology Data Exchange (ETDEWEB)

Jayaselli, J.; Cheemala, J. Manila Sagar; Geetha Rani, D.P.; Pal, Sarbani [MNR Post Graduate College, Kukatpally, Hyderabad (India). Dept. of Chemistry]. E-mail: sarbani277@yahoo.com

2008-07-01

A number of ester and sulfonate derivatives of piroxicam were prepared via acylation/sulfonation of the enolic OH of piroxicam. All the compounds were evaluated for their chemical stability and cyclooxygenase inhibiting properties. Data suggested that esters could be useful for the development of potential prodrugs. The sulfonate derivatives prepared for the first time were found to be stable. One of them showed a moderately selective COX-2 inhibition over COX-1 and would have lower gastrointestinal side effects than piroxicam due to the masked enolic OH group. A plausible mechanism for the acylation/sulfonation process has been proposed that involves participation of the pyridine moiety of piroxicam. Molecular structure of one of the ester was established for the first time by the crystal structure analysis from X-ray powder data. (author)

Derivatization of enolic OH of piroxicam: a comparative study on esters and sulfonates

International Nuclear Information System (INIS)

Jayaselli, J.; Cheemala, J. Manila Sagar; Geetha Rani, D.P.; Pal, Sarbani

2008-01-01

A number of ester and sulfonate derivatives of piroxicam were prepared via acylation/sulfonation of the enolic OH of piroxicam. All the compounds were evaluated for their chemical stability and cyclooxygenase inhibiting properties. Data suggested that esters could be useful for the development of potential prodrugs. The sulfonate derivatives prepared for the first time were found to be stable. One of them showed a moderately selective COX-2 inhibition over COX-1 and would have lower gastrointestinal side effects than piroxicam due to the masked enolic OH group. A plausible mechanism for the acylation/sulfonation process has been proposed that involves participation of the pyridine moiety of piroxicam. Molecular structure of one of the ester was established for the first time by the crystal structure analysis from X-ray powder data. (author)

Partially fluorinated arylene polyethers and their ternary blend membranes with PBI and H3PO4

DEFF Research Database (Denmark)

Kerres, J.; Schonberger, F.; Chromik, A

2008-01-01

A partially fluorinated polyether ionomer from polycondensation of decafluorobiphenyl with 2,2-bis(4-hydroxyphenyl)-hexafluoropropane, followed by sulphonation with H2SO4 (60% SO3), has been prepared and optimised in terms of molecular weight and sulphonation degree. The partially fluorinated ion...

Enchansing the Ionic Purity of Hydrophilic Channels by Blending Fully Sulfonated Graft Copolymers with PVDF Homopolymer

DEFF Research Database (Denmark)

Nielsen, Mads Møller; Ching-Ching Yang, Ami; Jankova Atanasova, Katja

2013-01-01

The influence of tuning the ionic content of membranes by blending, as opposed to varying the degree of sulfonation, is evaluated. Membranes of fully sulfonated poly(vinylidene fluoride-co-chlorotrifluoroethylene)-g-poly(styrene sulfonic acid) blended with PVDF were prepared and investigated...

Comparison of Linear and Hyperbranched Polyether Lipids for Liposome Shielding by 18F-Radiolabeling and Positron Emission Tomography.

Science.gov (United States)

Wagener, Karolin; Worm, Matthias; Pektor, Stefanie; Schinnerer, Meike; Thiermann, Raphael; Miederer, Matthias; Frey, Holger; Rösch, Frank

2018-04-27

Multifunctional and highly biocompatible polyether structures play a key role in shielding liposomes from degradation in the bloodstream, providing also multiple functional groups for further attachment of targeting moieties. In this work hyperbranched polyglycerol ( hbPG) bearing lipids with long alkyl chain anchor are evaluated with respect to steric stabilization of liposomes. The branched polyether lipids possess a hydrophobic bis(hexadecyl)glycerol membrane anchor for the liposomal membrane. hbPG was chosen as a multifunctional alternative to PEG, enabling the eventual linkage of multiple targeting vectors. Different hbPG lipids ( M n = 2900 and 5200 g mol -1 ) were examined. A linear bis(hexadecyl)glycerol-PEG lipid ( M n = 3000 g mol -1 ) was investigated as well, comparing hbPG and PEG with respect to shielding properties. Radiolabeling of the polymers was carried out using 1-azido-2-(2-(2-[ 18 F]fluoroethoxy)ethoxy)ethane ([ 18 F]F-TEG-N) 3 via copper-catalyzed alkyne-azide cycloaddition with excellent radiochemical yields exceeding 95%. Liposomes were prepared by the thin-film hydration method followed by repeated extrusion. Use of a custom automatic extrusion device gave access to reproducible sizes of the liposomes (hydrodynamic radius of 60-94 nm). The in vivo fate of the bis(hexadecyl)glycerol polyethers and their corresponding assembled liposome structures were evaluated via noninvasive small animal positron emission tomography (PET) imaging and biodistribution studies (1 h after injection and 4 h after injection) in mice. Whereas the main uptake of the nonliposomal polyether lipids was observed in the kidneys and in the bladder after 1 h due to rapid renal clearance, in contrast, the corresponding liposomes showed uptake in the blood pool as well as in organs with good blood supply, that is, heart and lung over the whole observation period of 4 h. The in vivo behavior of all three liposomal formulations was comparable, albeit with remarkable

Carbon dioxide sensing with sulfonated polyaniline

NARCIS (Netherlands)

Doan, D.C.T.; Ramaneti, R.; Baggerman, J.; Bent, van der J.; Marcelis, A.T.M.; Tong, H.D.; Rijn, van C.J.M.

2012-01-01

The use of polyaniline and especially sulfonated polyaniline (SPAN) is explored for sensing carbon dioxide (CO2) at room temperature. Frequency-dependent AC measurements were carried out to detect changes in impedance of the polymer, drop casted on interdigitated electrodes, when exposed to CO2 gas.

Controlled synthesis of multi-arm star polyether-polycarbonate polyols based on propylene oxide and CO2.

Science.gov (United States)

Hilf, Jeannette; Schulze, Patricia; Seiwert, Jan; Frey, Holger

2014-01-01

Multi-arm star copolymers based on a hyperbranched poly(propylene oxide) polyether-polyol (hbPPO) as a core and poly(propylene carbonate) (PPC) arms are synthesized in two steps from propylene oxide (PO), a small amount of glycidol and CO2 . The PPC arms are prepared via carbon dioxide (CO2 )/PO copolymerization, using hbPPO as a multifunctional macroinitiator and the (R,R)-(salcy)CoOBzF5 catalyst. Star copolymers with 14 and 28 PPC arms, respectively, and controlled molecular weights in the range of 2700-8800 g mol(-1) are prepared (Mw /Mn = 1.23-1.61). Thermal analysis reveals lowered glass transition temperatures in the range of -8 to 10 °C for the PPC star polymers compared with linear PPC, which is due to the influence of the flexible polyether core. Successful conversion of the terminal hydroxyl groups with phenylisocyanate demonstrates the potential of the polycarbonate polyols for polyurethane synthesis. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid polyether cleavage via extracellular one-electron oxidation by a brown-rot basidiomycete

OpenAIRE

Kerem, Zohar; Bao, Wuli; Hammel, Kenneth E.

1998-01-01

Fungi that cause brown rot of wood are essential biomass recyclers and also the principal agents of decay in wooden structures, but the extracellular mechanisms by which they degrade lignocellulose remain unknown. To test the hypothesis that brown-rot fungi use extracellular free radical oxidants as biodegradative tools, Gloeophyllum trabeum was examined for its ability to depolymerize an environmentally recalcitrant polyether, poly(ethylene oxide) (PEO), that cannot penetrate cell membranes....

Degradation and contamination of perfluorinated sulfonic acid membrane due to swelling-dehydration cycles

DEFF Research Database (Denmark)

Andersen, Shuang Ma; Morgen, Per; Skou, Eivind Morten

Formation of sulfonic anhydride S-O-S (from the condensation of sulfonic acids) was known one of the important degradation mechanisms [i] for Nafion membrane under hydrothermal aging condition, which is especially critical for hydrogen fuel cells. Similar mechanism would also have be desirable...... to the membrane degradation in direct methanol fuel cells (DMFCs), where liquid water has direct contact with the electrolyte. An ex-situ experiment was established with swelling-dehydration cycles on the membrane. However, formation of sulfonic anhydride was not detected during the entire treatment; instead...

Study on epoxy resin modified by polyether ionic liquid

Science.gov (United States)

Jin, X. C.; Guo, L. Y.; Deng, L. L.; Wu, H.

2017-06-01

Chloride 1-carboxyl polyether-3-methyl imidazole ionic liquid (PIIL) was synthesized. Then blended with epoxy resin(EP) to prepare the composite materials of PIIL/EP, which cured with aniline curing agent. The structure and curing performance of PIIL/EP were determined by FT-IR and DSC. The effects of the content of PIIL on strength of EP were studied. The results show that the PIIL was the target product. The strength was improved significantly with increase of the PIIL content. The obvious rubber elasticity of PIIL/EP after cured was showed when the content of PIIL accounts for 40% and the impact strength was up to 15.95kJ/m2.

Accelerated simulations of aromatic polymers: application to polyether ether ketone (PEEK)

Science.gov (United States)

Broadbent, Richard J.; Spencer, James S.; Mostofi, Arash A.; Sutton, Adrian P.

2014-10-01

For aromatic polymers, the out-of-plane oscillations of aromatic groups limit the maximum accessible time step in a molecular dynamics simulation. We present a systematic approach to removing such high-frequency oscillations from planar groups along aromatic polymer backbones, while preserving the dynamical properties of the system. We consider, as an example, the industrially important polymer, polyether ether ketone (PEEK), and show that this coarse graining technique maintains excellent agreement with the fully flexible all-atom and all-atom rigid bond models whilst allowing the time step to increase fivefold to 5 fs.

Salinomycin and other polyether ionophores are a new class of antiscarring agent.

Science.gov (United States)

Woeller, Collynn F; O'Loughlin, Charles W; Roztocil, Elisa; Feldon, Steven E; Phipps, Richard P

2015-02-06

Although scarring is a component of wound healing, excessive scar formation is a debilitating condition that results in pain, loss of tissue function, and even death. Many tissues, including the lungs, heart, skin, and eyes, can develop excessive scar tissue as a result of tissue injury, chronic inflammation, or autoimmune disease. Unfortunately, there are few, if any, effective treatments to prevent excess scarring, and new treatment strategies are needed. Using HEK293FT cells stably transfected with a TGFβ-dependent luciferase reporter, we performed a small molecule screen to identify novel compounds with antiscarring activity. We discovered that the polyether ionophore salinomycin potently inhibited the formation of scar-forming myofibroblasts. Salinomycin (250 nm) blocked TGFβ-dependent expression of the cardinal myofibroblast products α smooth muscle actin, calponin, and collagen in primary human fibroblasts without causing cell death. Salinomycin blocked phosphorylation and activation of TAK1 and p38, two proteins fundamentally involved in signaling myofibroblast and scar formation. Expression of constitutively active mitogen activated kinase kinase 6, which activates p38 MAPK, attenuated the ability of salinomycin to block myofibroblast formation, demonstrating that salinomycin targets the p38 kinase pathway to disrupt TGFβ signaling. These data identify salinomycin and other polyether ionophores as novel potential antiscarring therapeutics. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Andrographolide sulfonate improves Alzheimer-associated phenotypes and mitochondrial dysfunction in APP/PS1 transgenic mice.

Science.gov (United States)

Geng, Ji; Liu, Wen; Xiong, Yuyun; Ding, Hongqun; Jiang, Chunhong; Yang, Xiaoling; Li, Xiang; Elgehama, Ahmed; Sun, Yang; Xu, Qiang; Guo, Wenjie; Gao, Jing

2018-01-01

Alzheimer's disease is a neurodegenerative disorder with Amyloid-β plaques onset, synaptic damage, and cognitive decline. Aβ deposits cause pathological events including oxidative stress, mitochondrial dysfunction, and neuron death. In this study, APPswe/PSENΔ9 double transgenic mice model was used to imitate Alzheimer's disease and the effect and possible mechanism of Andrographolide sulfonate were examined. Andrographolide sulfonate was given to the mice for 7 months before the onset of Aβ plaque. Spatial memory test showed that Andrographolide sulfonate treatment prevented cognitive decline. Aβ deposits were not affected while hippocampus and synapse damage was significantly alleviated. Mechanism studies showed that oxidative stress and mitochondrial swelling was reduced after Andrographolide sulfonate administration. These findings suggest that Andrographolide sulfonate, which has been applied in clinical medicine, might be a promising therapeutic agent for AD therapy via mitochondria protection. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Immobilization of Mo(IV) complex in hybrid matrix obtained via sol-gel technique

Energy Technology Data Exchange (ETDEWEB)

Marques, C.; Sousa, A.M.; Freire, C.; Neves, I.C.; Fonseca, A.M.; Silva, C.J.R

2003-10-06

A molybdenum(IV) complex, trans-bis-[1,2-bis(diphenylphosphino)ethane]-fluoro-(diazopropano) -molybdenum tetraphenylborate, [MoF(DIAZO)(dppe){sub 2}][BPh{sub 4}], was prepared and immobilized in a hybrid matrix synthesized by the sol-gel process. The host matrix, designated as U(500), is an organic-inorganic network material, classed as ureasil, that combines a reticulated siliceous backbone linked by short polyether-based segments. Urea bridges make the link between these two components, and the polymerization of silicate substituted terminal groups generates the inorganic network. The free Mo(IV) complex and all new materials were characterized by spectroscopic techniques (FT-IR and UV-Vis) and thermal analysis (DSC). The ionic conductivity of the resulting material was also studied. The results indicate that immobilized Mo(IV) complex has kept its solid-state structure, although there is evidence of inter-molecular interactions between the Mo(IV) complex and some groups/atoms of the hybrid host matrix.

Molecular dynamics simulations to calculate glass transition temperature and elastic constants of novel polyethers.

Science.gov (United States)

Sarangapani, Radhakrishnan; Reddy, Sreekantha T; Sikder, Arun K

2015-04-01

Molecular dynamics simulations studies are carried out on hydroxyl terminated polyethers that are useful in energetic polymeric binder applications. Energetic polymers derived from oxetanes with heterocyclic side chains with different energetic substituents are designed and simulated under the ensembles of constant particle number, pressure, temperature (NPT) and constant particle number, volume, temperature (NVT). Specific volume of different amorphous polymeric models is predicted using NPT-MD simulations as a function of temperature. Plots of specific volume versus temperature exhibited a characteristic change in slope when amorphous systems change from glassy to rubbery state. Several material properties such as Young's, shear, and bulk modulus, Poisson's ratio, etc. are predicted from equilibrated structures and established the structure-property relations among designed polymers. Energetic performance parameters of these polymers are calculated and results reveal that the performance of the designed polymers is comparable to the benchmark energetic polymers like polyNIMMO, polyAMMO and polyBAMO. Overall, it is worthy remark that this molecular simulations study on novel energetic polyethers provides a good guidance on mastering the design principles and allows us to design novel polymers of tailored properties. Copyright © 2015 Elsevier Inc. All rights reserved.

Polyether precursors of molecular recognition systems based on the 9,10-anthraquinone moiety

Science.gov (United States)

Wcisło, Anna; Cirocka, Anna; Zarzeczańska, Dorota; Niedziałkowski, Paweł; Nakonieczna, Sandra; Ossowski, Tadeusz

2015-02-01

A series of novel polyether derivatives of 9,10-anthraquinone (AQ) was synthesized and characterized by means of UV-Vis spectroscopy, acid-base titration and complexometric titration. The results were compared with 1-NEt2AQ and 1-NHEtAQ - model compounds of alkylaminoanthraquinones. Acetonitrile and methanol were used as solvents for determination of spectroscopic and acid-base properties. Complexometric titrations were carried out exclusively in acetonitrile. Spectral characteristic of these compounds strongly depends on pH. Addition of acid causes the decrease of absorption intensity and in some cases also a shift of the visible range band. The weakest base is the compound (2), and the strongest - compound (1), both in methanol and acetonitrile solution. The introduction of an additional substituent in the position 8 of the anthraquinone compound increases its basicity. The presence of metal ions causes changes in intensity of absorption (decrease for compounds (2) and (3) and increase with bathochromic shift for (1) and (4)). For the determination of the coordination properties aluminum (III) ions were chosen. The highest complex stability constant with Al (III) ions is observed for compound (1), and the weakest for compound (3). The elongation of the polyether chain decreases the stability of the complex formed.

Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

Science.gov (United States)

Cooper, George W.; Thiemens, Mark H.; Jackson, Teresa L.; Chang, Sherwood

1997-01-01

Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

Formation of core (polystyrene)-shell (polybenzimidazole) nanoparticles using sulfonated polystyrene as template.

Science.gov (United States)

Hazarika, Mousumi; Arunbabu, Dhamodaran; Jana, Tushar

2010-11-15

We report formation of core (polystyrene)-shell (polybenzimidazole) nanoparticles from a new blend system consisting of an amorphous polymer polybenzimidazole (PBI) and an ionomer sodium salt of sulfonated polystyrene (SPS-Na). The ionomer used for the blending is spherical in shape with sulfonate groups on the surface of the particles. An in depth investigation of the blends at various sulfonation degrees and compositions using Fourier transform infrared (FT-IR) spectroscopy provides direct evidence of specific hydrogen bonding interactions between the N-H groups of PBI and the sulfonate groups of SPS-Na. The disruption of PBI chains self association owing to the interaction between the functional groups of these polymer pairs is the driving force for the blending. Thermodynamical studies carried out by using differential scanning calorimeter (DSC) establish partially miscible phase separated blending of these polymers in a wider composition range. The two distinguishable glass transition temperatures (T(g)) which are different from the neat components and unaltered with the blends composition attribute that the domain size of heterogeneity (d(d)) of the blends is >20 nm since one of the blend component (SPS-Na particle) diameter is ∼70 nm. The diminish of PBI chains self association upon blending with SPS-Na particles and the presence of invariant T(g)'s of the blends suggest the wrapping of PBI chains over the SPS-Na spherical particle surface and hence resulting a core-shell morphology. Transmission electron microscopy (TEM) study provides direct evidence of core-shell nanoparticle formation; where core is the polystyrene and shell is the PBI. The sulfonation degree affects the blends phase separations. The higher degree of sulfonation favors the disruption of PBI self association and thus forms partially miscible two phases blends with core-shell morphology. Copyright © 2010 Elsevier Inc. All rights reserved.

Martinomycin, a new polyether antibiotic produced by Streptomyces salvialis. I. Taxonomy, fermentation and biological activity.

Science.gov (United States)

Bernan, V S; Montenegro, D A; Goodman, J J; Alluri, M R; Carter, G T; Abbanat, D R; Pearce, C J; Maiese, W M; Greenstein, M

1994-12-01

Actinomycete culture LL-D37187 has been found to produce the new polyether antibiotic martinomycin. Taxonomic studies, including morphological, physiological, and cell wall chemistry analyses, revealed that culture LL-D37187 is a novel streptomycete species, and the proposed name is Streptomyces salvialis. Martinomycin exhibits activity against the Southern Army Worm (Spodoptera eridania) and Gram-positive bacteria.

A polyether glycol derived from cashew nutshell as a kinetic inhibitor for methane hydrate formation

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Jorge Cesar; Esteves, Pierre M., E-mail: pesteves@iq.ufrj.br [Instituto de Quimica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Teixeira, Adriana [Centro de Pesquisa e Desenvolvimento Leopoldo Americo Miguez de Mello, PETROBRAS, Rio de Janeiro, RJ (Brazil)

2012-07-01

The polyether glycol derived from cashew nutshell liquid inhibited the formation of methane hydrate. The polymer proved to be more efficient than the polyvinyl pyrrolidone-poly(N-vinyl) caprolactam (PVP-PVCap) co-polymer under tested conditions (CH{sub 4}, 1470 psi and 4 degree C), being the latter one of the best commercially available hydrate inhibitors. (author)

Characterization of ureasil-polyethylene oxide/chitosan hybrid materials

Energy Technology Data Exchange (ETDEWEB)

Paredes Zaldivar, M.; Pulcinelli, S.H.; Peniche Covas, C.; Santilli, C.V. [Universidad de la Habana, Havana (Cuba); Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Instituto de Quimica

2016-07-01

Full text: Siloxane-polyether hybrids are an interesting and versatile family of multifunctional organic-inorganic hybrid materials, also named ureasils. Ureasils have been the object of intensive studies in the last years due to their versatility and wide range of applications. Polyethylene oxide (PEO) and chitosan are biocompatible and low toxicity polymers that were used as organic phase while the inorganic phase was siloxane. Therefore, the aim of this work was the characterization of these hybrids that were prepared by the sol–gel route. Hydrochloric and acetic acids were used as catalysts. Due to the insolubility of chitosan in ethanol and organic solvents, water was used in the hydrolysis solution as the main component or alone. The obtained materials were transparent, rubbery, flexible and water-insoluble. They were characterized by different physicochemical techniques such as FTIR (Fourier Transform Infrared Spectroscopy), DSC (Differential Scanning Calorimetry), TG (Thermogravimetric Analysis), XRD (X-Ray Diffraction), SAXS (Small Angle X-ray Scattering) and NMR (Nuclear Magnetic Resonance Spectroscopy). Results showed that chitosan addition did not provoke appreciable changes in the thermal properties but modifies the polycondensation degree and the nanoscopic structure of the materials. Significant changes were not found neither by the hydrolysis solution nor by the type of acid, except in the thermal stability. It depended on the type of acid catalyst, being higher in hybrids prepared with HCl. We can conclude that these materials can be synthesized just with water as the hydrolysis solution and that any of the two acids can be used as catalyst without significantly affect its final properties. (author)

Colonic necrosis due to calcium polystyrene sulfonate (Kalimate not suspended in sorbitol

Directory of Open Access Journals (Sweden)

María Dolores Castillo-Cejas

2013-04-01

Full Text Available Cation-exchange resins are used in the management of hyperkalemia, particularly in patients with end-stage renal disease. These resins were associated with gastrointestinal tract lesions, especially sodium polystyrene sulfonate (Kayexalate mixed with sorbitol. We present a case of colonic necrosis after the administration of calcium polystyrene sulfonate (Kalimate not suspended in sorbitol.

Sulfonation of cPTFE Film grafted Styrene for Proton Exchange Membrane Fuel Cell

Directory of Open Access Journals (Sweden)

Yohan Yohan

2010-10-01

Full Text Available Sulfonation of γ-ray iradiated and styrene-grafted crosslinked polytetrafluoroethylene film (cPTFE-g-S film have been done. The aim of the research is to make hydropyl membrane as proton exchange membrane fuel cell. Sulfonation was prepared with chlorosulfonic acid in chloroethane under various conditions. The impact of the percent of grafting, the concentration of chlorosulfonic acid, the reaction time,and the reaction temperature on the properties of sulfonated film is examinated. The results show that sulfonation of surface-grafted films is incomplete at room  temperature. The increasing of concentration of chlorosulfonic acid and reaction temperature accelerates the reaction but they also add favor side reactions. These will lead to decreasing of the ion-exchange capacity, water uptake, and proton conductivity but increasing the resistance to oxidation in a perhidrol solution. The cPTFE-g-SS membrane which is resulted has stability in a H2O2 30% solution for 20 hours.

Ionomers based on multisulfonated perylene dianhydride: Synthesis and properties of water resistant sulfonated polyimides

Energy Technology Data Exchange (ETDEWEB)

Zhang, Feng; Li, Nanwen [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Suobo; Li, Shenghai [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China)

2010-04-15

A novel locally and densely sulfonated dianhydride with four sulfonic acid groups, 1,6,7,12-tetra[4-(sulfonic acid)phenoxy]perylene-3,4,9,10-tetracarboxylic dianhydride (SPTDA), was successfully synthesized by direct sulfonation of the parent dianhydride, 1,6,7,12-tetraphenoxyperylene-3,4,9,10-tetracarboxylic dianhydride (PTDA). Sulfonated copolyimides were prepared from SPTDA, nonsulfonated dianhydride 4,4'-binaphthyl-1,1',8,8'-tetracarboxylic dianydride, 4,4'-diaminodiphenyl ether (a) or dodecane-1,12-diamine (b). The synthesized copolymers, with the -SO{sub 3}H group on the polymer side chain, possess high molecular weights and high viscosities, and they form tough, flexible membranes. The copolymer membrane with an ion exchange capacity of 2.69 mequiv. g{sup -1} had a proton conductivity of 0.126 S cm{sup -1} at 20 C and 0.292 S cm{sup -1} at 100 C; the latter is much higher than that of Nafion {sup registered} 117 under the same conditions. The mechanical properties of the copolymer membranes were almost unchanged after accelerated water stability testing at 140 C for 100 h; this indicates excellent hydrolytic stability of the synthesized copolyimides. (author)

Aryl sulfonate based anticancer alkylating agents.

Science.gov (United States)

Sheikh, Hamdullah Khadim; Arshad, Tanzila; Kanwal, Ghazala

2018-05-01

This research work revolves around synthesis of antineoplastic alkylating sulfonate esters with dual alkylating sites for crosslinking of the DNA strands. These molecules were evaluated as potential antineoplastic cross linking alkylating agents by reaction with the nucleoside of Guanine DNA nucleobase at both ends of the synthesized molecule. Synthesis of the alkylating molecules and the crosslinking with the guanosine nucleoside was monitored by MALDITOF mass spectroscopy. The synthesized molecule's crosslinking or adduct forming rate with the nucleoside was compared with that of 1,4 butane disulfonate (busulfan), in form of time taken for the appearance of [M+H] + . It was found that aryl sulfonate leaving group was causing higher rate of nucleophilic attack by the Lewis basic site of the nucleobase. Furthermore, the rate was also found to be a function of electron withdrawing or donating nature of the substituent on the aryl ring. Compound with strong electron withdrawing substituent on the para position of the ring reacted fastest. Hence, new alkylating agents were synthesized with optimized or desired reactivity.

Evaluation of sulfonated carbon as catalyst in reactive distillation

International Nuclear Information System (INIS)

Orjuela, Alvaro; Civetta, Nicolas; Rivera, Jairo; Boyaca, Alejandro; Diaz, Jesus

2004-01-01

A packed bed using sulfonated coal catalytic pellets was prepared using a Colombian anthracitic coal. Such pellets were introduced in a semi batch distillation column to which acetic acid and ethanol were fed in order to determine experimentally the feasibility of obtaining ethyl acetate by reactive distillation operation. The carbonaceous catalytic packing was characterized by total exchange capacity, potentiometric titration and BET area. Experimental tests were carried out using three acid/alcohol ratios. Results of such process are shown by reaction conversion and concentration in distillate and bottom products. The sulfonated coal showed catalytic activity in this esterification reaction, with conversions between 29-45%

Composite plasma polymerized sulfonated polystyrene membrane for PEMFC

Energy Technology Data Exchange (ETDEWEB)

Nath, Bhabesh Kumar; Khan, Aziz; Chutia, Joyanti, E-mail: jchutiaiasst@gmail.com

2015-10-15

Highlights: • Methyl methane sulfonate (MMS) is used as the sulfonating agent. • The proton conductivity of the membrane is found to be 0.141 S cm{sup −1}. • Power density of fuel cell with styrene/MMS membrane is 0.5 W cm{sup −2}. • The membrane exhibits thermal stability up to 140 °C. - Abstract: This work presents the introduction of an organic compound methyl methane sulfonate (MMS) for the first time in fabrication of polystyrene based proton exchange membrane (PEM) by plasma polymerization process. The membrane is fabricated by co-polymerizing styrene and MMS in capacitively coupled continuous RF plasma. The chemical composition of the plasma polymerized polymer membrane is investigated using Fourier Transform Infrared Spectroscopy which reveals the formation of composite structure of styrene and MMS. The surface morphology studied using AFM and SEM depicts the effect of higher partial pressure of MMS on surface topography of the membrane. The proton transport property of the membrane studied using electrochemical impedance spectroscopy shows the achievement of maximum proton conductivity of 0.141 S cm{sup −1} which is comparable to Nafion 117 membrane. Fuel cell performance test of the synthesized membrane shows a maximum power density of 500 mW cm{sup −2} and current density of 0.62 A cm{sup −2} at 0.6 V.

Modeling Replenishment of Ultrathin Liquid Perfluoro polyether Z Films on Solid Surfaces Using Monte Carlo Simulation

International Nuclear Information System (INIS)

Mayeed, M.S.; Kato, T.

2014-01-01

Applying the reptation algorithm to a simplified perfluoro polyether Z off-lattice polymer model an NVT Monte Carlo simulation has been performed. Bulk condition has been simulated first to compare the average radius of gyration with the bulk experimental results. Then the model is tested for its ability to describe dynamics. After this, it is applied to observe the replenishment of nano scale ultrathin liquid films on solid flat carbon surfaces. The replenishment rate for trenches of different widths (8, 12, and 16 nms for several molecular weights) between two films of perfluoro polyether Z from the Monte Carlo simulation is compared to that obtained solving the diffusion equation using the experimental diffusion coefficients of Ma et al. (1999), with room condition in both cases. Replenishment per Monte Carlo cycle seems to be a constant multiple of replenishment per second at least up to 2 nm replenished film thickness of the trenches over the carbon surface. Considerable good agreement has been achieved here between the experimental results and the dynamics of molecules using reptation moves in the ultrathin liquid films on solid surfaces.

Physico-chemistry characterization of sulfonated polyacrylamide polymers for use in polymer flooding

Energy Technology Data Exchange (ETDEWEB)

Rashidi, Masoud

2010-07-01

Hydrolyzed polyacrylamide polymer (HPAM) as a feasible and effective viscosifier has been fully studied and used for polymer flooding processes in several oil field, e.g. Daqing oil field. It has been shown that Hydrolyzed polyacrylamide polymers (HPAM) may be a good choice for high temperature condition with no oxygen and no divalent ions presence. At high temperature and high salinity conditions, polymer may precipitates and loss their viscosyfing properties. Also adsorption and retention of polymer in porous medium may change rheological properties of polymers. Thus, the viscosyfing property of polymers is influenced by several important parameters, e.g. salinity, hardness, temperature, adsorption, retention, polymer structure, and etc. By replacing some of carboxylate group of HPAM with another monomer, e.g. sodium salt of acrylic acid and 2-acrylamido-2-methylpropane sulfonic acid (AMPS), effect of high salinity/hardness and temperature seems to be reduced specially for the samples with higher percentage of AMPS co-monomer. The ultimate aim of this work is to develop an understanding of the sulfonated polyacrylamide copolymers with a range of different sulfonation and molecular weight at high salinity and high temperature conditions. Most of the work in this thesis deals with viscosity and adsorption/retention measurements of the sulfonated copolymers and HPAM. The factors which may affect the viscosity of the polymers and have been identified in this work as most likely influencing also adsorption and retention of the polymers are shear rate, polymer concentration, sulfonation degree, molecular weight, NaCl concentration, divalent ion concentration, and temperature. (Author)

Ion-conductive properties of polyether-based composite electrolytes filled with mesoporous silica, alumina and titania

International Nuclear Information System (INIS)

Tominaga, Yoichi; Endo, Masanori

2013-01-01

Composite polymer electrolytes were prepared consisting of amorphous polyether, Li salt and mesoporous inorganic filler, and we investigated their ion-conductive properties. We synthesized three types of filler, mesoporous silica, alumina and titania (MP-Si, Al, Ti), and characterized their structural and physicochemical properties using SEM, TEM, SAXS and BET surface area measurements. From these measurements, we confirmed that MP fillers have well-defined arrays of mesoporous and hexagonal structures. Dependence on the MP filler content of the glass transition temperature (T g ) revealed that the addition of filler to original polyether-salt electrolyte causes T g decrease, to due to the dissociation of aggregated ions such as triples or crystalline complex domains. The MP-Ti composites had the greatest ionic conductivity (1.4 × 10 −5 S/cm, 7.5 wt% at 30 °C) of all samples, and the values were more than double that of the original. The addition of MP-Ti also increased the lithium transference number, because the electrolyte/filler interface provided active sites that increase mobile Li ions and conducting paths so as to enhance the mobility

Nature of strontium extraction by synergistic mixtures of chlorinated cobalt dicarbollide and polyethers

International Nuclear Information System (INIS)

Smirnov, I.V.; Stoyanov, E.S.; Vorob'eva, T.P.

2003-01-01

Extraction of strontium by synergistic mixtures of chlorinated cobalt dicarbollide (DCC) with different polyethers was studied. In the acidic media the distribution coefficients (D(Sr)) decreases in the order 15-crown-5 > PEG-400 > 18-crown-6 and does not correspond to the row of constants stability of the strontium complexes with these polyethers. When passing to the salt media (Li and Na nitrates) the row of D(Sr) is changed: PEG-400 > 18 crown 6 > 15 crown 5. IR-spectroscopy study has shown that in synergistic mixtures the proton forms [H 5O2 + .PEG], [H 5O2 + .(15-crown-5)2] and [H 3 O + .(18 crown 6)] cations, which are exchange on Sr 2+ resulting to formation [Sr 2+ .PEG], [Sr 2+ .(15-crown-5)2] and [Sr 2+ .(18-crown-6)(H 2 O)n] cations correspondingly. The PEG-400 is the best among polyethylene glycols, since its all six COC groups and two even more active OH groups complete the first co-ordination sphere of Sr 2+ . Extremely low extractability of Sr 2+ from acidic media in the presence of 18-crown-6 as compared with 15-crown-5 is mainly caused by the high stability of the [H 3 O + .(18-crown-6)] cation that is responsible for less extractable hydrated Sr complex formation. (author)

Studies toward brevisulcenal F via convergent strategies for marine ladder polyether synthesis.

Science.gov (United States)

Katcher, Matthew; Jamison, Timothy F

2018-03-15

Shortly after the initial isolation of marine ladder polyether natural products, biomimetic epoxide-opening cascade reactions were proposed as an efficient strategy for the synthesis of these compounds. However, difficulties in assembling the cascade precursors have limited the realization of these cascades. In this report, we describe strategies that provide convergent access to cascade precursors via regioselective allylation and efficient fragment coupling. We then investigate epoxide-opening cascades promoted by strong bases for the formation of fused tetrahydropyrans. These strategies are evaluated in the context of the synthesis of rings CDEFG of brevisulcenal F.

iNOS Activity Modulates Inflammation, Angiogenesis, and Tissue Fibrosis in Polyether-Polyurethane Synthetic Implants.

Science.gov (United States)

Cassini-Vieira, Puebla; Araújo, Fernanda Assis; da Costa Dias, Filipi Leles; Russo, Remo Castro; Andrade, Silvia Passos; Teixeira, Mauro Martins; Barcelos, Luciola Silva

2015-01-01

There is considerable interest in implantation techniques and scaffolds for tissue engineering and, for safety and biocompatibility reasons, inflammation, angiogenesis, and fibrosis need to be determined. The contribution of inducible nitric oxide synthase (iNOS) in the regulation of the foreign body reaction induced by subcutaneous implantation of a synthetic matrix was never investigated. Here, we examined the role of iNOS in angiogenesis, inflammation, and collagen deposition induced by polyether-polyurethane synthetic implants, using mice with targeted disruption of the iNOS gene (iNOS(-/-)) and wild-type (WT) mice. The hemoglobin content and number of vessels were decreased in the implants of iNOS(-/-) mice compared to WT mice 14 days after implantation. VEGF levels were also reduced in the implants of iNOS(-/-) mice. In contrast, the iNOS(-/-) implants exhibited an increased neutrophil and macrophage infiltration. However, no alterations were observed in levels of CXCL1 and CCL2, chemokines related to neutrophil and macrophage migration, respectively. Furthermore, the implants of iNOS(-/-) mice showed boosted collagen deposition. These data suggest that iNOS activity controls inflammation, angiogenesis, and fibrogenesis in polyether-polyurethane synthetic implants and that lack of iNOS expression increases foreign body reaction to implants in mice.

iNOS Activity Modulates Inflammation, Angiogenesis, and Tissue Fibrosis in Polyether-Polyurethane Synthetic Implants

Science.gov (United States)

Cassini-Vieira, Puebla; Araújo, Fernanda Assis; da Costa Dias, Filipi Leles; Russo, Remo Castro; Andrade, Silvia Passos; Teixeira, Mauro Martins; Barcelos, Luciola Silva

2015-01-01

There is considerable interest in implantation techniques and scaffolds for tissue engineering and, for safety and biocompatibility reasons, inflammation, angiogenesis, and fibrosis need to be determined. The contribution of inducible nitric oxide synthase (iNOS) in the regulation of the foreign body reaction induced by subcutaneous implantation of a synthetic matrix was never investigated. Here, we examined the role of iNOS in angiogenesis, inflammation, and collagen deposition induced by polyether-polyurethane synthetic implants, using mice with targeted disruption of the iNOS gene (iNOS−/−) and wild-type (WT) mice. The hemoglobin content and number of vessels were decreased in the implants of iNOS−/− mice compared to WT mice 14 days after implantation. VEGF levels were also reduced in the implants of iNOS−/− mice. In contrast, the iNOS−/− implants exhibited an increased neutrophil and macrophage infiltration. However, no alterations were observed in levels of CXCL1 and CCL2, chemokines related to neutrophil and macrophage migration, respectively. Furthermore, the implants of iNOS−/− mice showed boosted collagen deposition. These data suggest that iNOS activity controls inflammation, angiogenesis, and fibrogenesis in polyether-polyurethane synthetic implants and that lack of iNOS expression increases foreign body reaction to implants in mice. PMID:26106257

Assessment of Physical Stability and Antioxidant Activity of Polysiloxane Polyalkyl Polyether Copolymer-Based Creams

Directory of Open Access Journals (Sweden)

Atif Ali

2013-01-01

Full Text Available The purpose of the present work was to investigate the changes on physical stability (color, creaming, liquefaction, pH, conductivity, centrifugation, viscosity and rheological parameters by non-ionic surfactant polysiloxane polyalkyl polyether copolymer based creams following inclusion of plant extract containing phenolic compounds. The antioxidant activity of the plant extract alone and after addition in the cream was assessed using the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH assay. Physical stability was assessed by submitting the creams to storage at 8°C, 25°C, 40°C, and at 40°C with 70% RH (relative humidity for a period of two months. Physical characteristics of polysiloxane polyalkyl polyether copolymer based creams, that is, color, creaming, liquefaction, centrifugation and pH were noted at various intervals for 2 months. The viscosities and rheological behavior of creams were determined using a rotational rheometer. Data were analyzed by using Brookfield Software Rheocalc version (2.6 with IPC Paste and Power Law (PL math models. Cream with plant extract showed pseudo plastic behaviour with decreasing on viscosity. The Acacia nilotica (AN extract alone and the cream containing this extract showed great antioxidant and free radical scavenging activities. Power Law and IPC analysis were found to fit all the rheograms.

Preparation and Characterization of Sulfonated Poly (ether ether ...

African Journals Online (AJOL)

NJD

2007-08-10

Aug 10, 2007 ... Preparation and Characterization of Sulfonated Poly (ether ... Currently perfluori- ... with phosphoric acid solution according to the method described earlier.11,12 ... where A is the membrane area available for diffusion; CA is.

Perfluorooctane sulfonate (PFOS) depletion in beef cattle

Science.gov (United States)

Perfluorooctane sulfonate (PFOS) is an industrial chemical that is used as a surfactant in several manufactured consumer products but is also a breakdown product from other chemical surfactants. As a result of its extensive use, PFOS is ubiquitous in the environment and is often detected in biosoli...

Room temperature synthesis of biodiesel using sulfonated ...

Science.gov (United States)

Sulfonation of graphitic carbon nitride (g-CN) affords a polar and strongly acidic catalyst, Sg-CN, which displays unprecedented reactivity and selectivity in biodiesel synthesis and esterification reactions at room temperature. Prepared for submission to Royal Society of Chemistry (RSC) journal, Green Chemistry as a communication.

A Comparative Evaluation of the Linear Dimensional Accuracy of Four Impression Techniques using Polyether Impression Material.

Science.gov (United States)

Manoj, Smita Sara; Cherian, K P; Chitre, Vidya; Aras, Meena

2013-12-01

There is much discussion in the dental literature regarding the superiority of one impression technique over the other using addition silicone impression material. However, there is inadequate information available on the accuracy of different impression techniques using polyether. The purpose of this study was to assess the linear dimensional accuracy of four impression techniques using polyether on a laboratory model that simulates clinical practice. The impression material used was Impregum Soft™, 3 M ESPE and the four impression techniques used were (1) Monophase impression technique using medium body impression material. (2) One step double mix impression technique using heavy body and light body impression materials simultaneously. (3) Two step double mix impression technique using a cellophane spacer (heavy body material used as a preliminary impression to create a wash space with a cellophane spacer, followed by the use of light body material). (4) Matrix impression using a matrix of polyether occlusal registration material. The matrix is loaded with heavy body material followed by a pick-up impression in medium body material. For each technique, thirty impressions were made of a stainless steel master model that contained three complete crown abutment preparations, which were used as the positive control. Accuracy was assessed by measuring eight dimensions (mesiodistal, faciolingual and inter-abutment) on stone dies poured from impressions of the master model. A two-tailed t test was carried out to test the significance in difference of the distances between the master model and the stone models. One way analysis of variance (ANOVA) was used for multiple group comparison followed by the Bonferroni's test for pair wise comparison. The accuracy was tested at α = 0.05. In general, polyether impression material produced stone dies that were smaller except for the dies produced from the one step double mix impression technique. The ANOVA revealed a highly

Ionomeric membranes based on partially sulfonated poly(styrene) : synthesis, proton conduction and methanol permeation

NARCIS (Netherlands)

Picchioni, F.; Tricoli, V.; Carretta, N.

2000-01-01

Homogeneuosly sulfonated poly(styrene) (SPS) was prepared with various concentration of sulfonic acid groups in the base polymer. Membranes cast from these materials were investigated in relation to proton conductivity and methanol permeability in the temperature range from 20°C to 60°C. It was

Ionomeric membranes based on partially sulfonated poly(styrene): synthesis, proton conduction and methanol permeation

NARCIS (Netherlands)

Carretta, N.; Tricoli, V.; Picchioni, F.

2000-01-01

Homogeneuosly sulfonated poly(styrene) (SPS) was prepared with various concentration of sulfonic acid groups in the base polymer. Membranes cast from these materials were investigated in relation to proton conductivity and methanol permeability in the temperature range from 20°C to 60°C. It was

Tetraoxane-pyrimidine nitrile hybrids as dual stage antimalarials.

Science.gov (United States)

Oliveira, Rudi; Guedes, Rita C; Meireles, Patrícia; Albuquerque, Inês S; Gonçalves, Lídia M; Pires, Elisabete; Bronze, Maria Rosário; Gut, Jiri; Rosenthal, Philip J; Prudêncio, Miguel; Moreira, Rui; O'Neill, Paul M; Lopes, Francisca

2014-06-12

The use of artemisinin or other endoperoxides in combination with other drugs is a strategy to prevent development of resistant strains of Plasmodium parasites. Our previous work demonstrated that hybrid compounds, comprising endoperoxides and vinyl sulfones, were capable of high activity profiles comparable to artemisinin and chloroquine while acting through two distinct mechanisms of action: oxidative stress and falcipain inhibition. In this study, we adapted this approach to a novel class of falcipain inhibitors: peptidomimetic pyrimidine nitriles. Pyrimidine tetraoxane hybrids displayed potent nanomolar activity against three strains of Plasmodium falciparum and falcipain-2, combined with low cytotoxicity. In vivo, a decrease in parasitemia and an increase in survival of mice infected with Plasmodium berghei was observed when compared to control. All tested compounds combined good blood stage activity with significant effects on liver stage parasitemia, a most welcome feature for any new class of antimalarial drug.

Novel Organic-Inorganic Hybrid Electrolyte to Enable LiFePO4 Quasi-Solid-State Li-Ion Batteries Performed Highly around Room Temperature.

Science.gov (United States)

Tan, Rui; Gao, Rongtan; Zhao, Yan; Zhang, Mingjian; Xu, Junyi; Yang, Jinlong; Pan, Feng

2016-11-16

A novel type of organic-inorganic hybrid polymer electrolytes with high electrochemical performances around room temperature is formed by hybrid of nanofillers, Y-type oligomer, polyoxyethylene and Li-salt (PBA-Li), of which the T g and T m are significantly lowered by blended heterogeneous polyethers and embedded nanofillers with benefit of the dipole modification to achieve the high Li-ion migration due to more free-volume space. The quasi-solid-state Li-ion batteries based on the LiFePO 4 /15PBA-Li/Li-metal cells present remarkable reversible capacities (133 and 165 mAh g -1 @0.2 C at 30 and 45 °C, respectively), good rate ability and stable cycle performance (141.9 mAh g -1 @0.2 C at 30 °C after 150 cycles).

Perfluoroalkyl sulfonates cause alkyl chain length-dependent hepatic steatosis and hypolipidemia mainly by impairing lipoprotein production in APOE*3-leiden CETP mice

NARCIS (Netherlands)

Bijland, S.; Rensen, P.C.N.; Pieterman, E.J.; Maas, A.C.E.; Hoorn, J.W. van der; Erk, M.J. van; Havekes, L.M.; Dijk, K.W. van; Chang, S.C.; Ehresman, D.J.; Butenhoff, J.L.; Princen, H.M.G.

2011-01-01

Perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) are stable perfluoroalkyl sulfonate (PFAS) surfactants, and PFHxS and PFOS are frequently detected in human biomonitoring studies. Some epidemiological studies have shown modest positive

Electrically conductive poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate)/polyacrylonitrile fabrics for humidity sensors

International Nuclear Information System (INIS)

Panapoy, Manop; Singsang, Witawat; Ksapabutr, Bussarin

2010-01-01

Humidity sensors based on poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT-PSS)/polyacrylonitrile (PAN) nanofiber fabric were fabricated by a dip coating of nonwoven PAN nanofiber mat, which was prepared via an electrospinning method, in PEDOT-PSS solution. The influence of PAN solution concentration on their responsiveness to humidity on dynamic testing was monitored as the device was exposed to humidity. With the relative humidity (RH) changing from 0 to 100%, a resistance device response over 110% was achieved, and the curve of the resistance response with RH is of high linearity at the humidity working range of 0-100% RH. The high device reproducibility was demonstrated by carrying out vapor adsorption-desorption dynamic cycles, and the response and recovery times were determined to be of the order of 2-46 and 7-34 s, respectively. These hybrid polymer sensors can be used as disposable handheld instruments due to low cost and light weight.

Stability complexes of lanthanide ions with some macrocyclic polyethers

International Nuclear Information System (INIS)

Poluehktov, N.S.; Malinka, E.V.; Meshkova, S.B.; Bel'tyukova, S.V.; Danilkovich, M.M.

1984-01-01

Stability of lanthanide complexes with macrocyclic polyethers has been studied versus the number of f-electrons, spin- and orbital angular momenta of the Lu 3+ ion ground states. The following compounds were used as macrocyclic complexones: 12-crown-4 (12C4), tert-bulylbenzo-15-crown-5(BB15C5), 18-crown-6 (18C6), ditert-butylbenzo-18-crown-6(DBB18C6), dibenzo-30-crown-10 (DB30C10), cryptand [2, 2, 1] (Cr[2, 2, 1]). It is shoWn that the stability constants of the studied lanthanide complexes can be described rather satisfactorily by an expression suggested earlier that relates their values with the number of 4f-electrons and the S and L quantum numbers of the ground states of the lantharide ions

Organic-inorganic hybrid polyionic liquid based polyoxometalate as nano porous material for selective oxidation of sulfides

Science.gov (United States)

Rafiee, Ezzat; Shahebrahimi, Shabnam

2017-07-01

Organic-inorganic hybrid nano porous materials based on poly(ionic liquid)-polyoxometalate (PIL-POM) were reported. These hybrid materials were synthesized by the reaction of 4-vinyl pyridine with 1,3-propanesultone, followed by the polymerization and also sulfonate-functionalized cross-linked poly(4-vinylpyridine) and combining these polymers with H5PMo10V2O40 (PMo10V2). Activity of prepared PIL-PMo10V2 hybrids were investigated as catalysts for oxidation of sulfides with H2O2 as oxidant. For understanding catalytic activities of the PIL-PMo10V2 hybrids in oxidation of sulfides, effect of catalyst composition, substrate, and reaction conditions were studied. The results show that the PIL-PMo10V2 hybrids are active as selective heterogeneous catalysts for oxidation of sulfides and can be recovered and reused. The catalyst was characterized by FT-IR, TGA-DSC, XRD, SEM/EDX, BET, CV and zeta potential measurement. Also, average molecular weight of prepared catalysts were measured.

Destruction of gel sulfonated cation-exchangers of the KU-2 type under the influence of hydrogen peroxide

Energy Technology Data Exchange (ETDEWEB)

Roginskaya, B.S.; Zavadovskaya, A.S.; Znamenskii, Yu.P.; Paskhina, N.A.; Dobrova, E.I.

1988-10-20

The purpose of this work was to study the mechanism of interaction of Soviet sulfonated cation-exchangers of the KU-2 type with hydrogen peroxide. It is shown that under the influence of hydrogen peroxide sulfonated cation-exchangers begin, after a certain induction period, to lose capacity and to release destruction products into water; the length of the induction period increases with the degree of cross-linking. In a given time of contact between the resin and the solution the degree of destruction falls with increase of cross-linking. The principal product of destruction of sulfonated cation-exchangers is an aromatic sulfonic acid containing oxidized groups in the side chains.

Evaluation of the Efficacy of Different Mixing Techniques and Disinfection on Microbial Colonization of Polyether Impression Materials: A Comparative Study.

Science.gov (United States)

Singla, Youginder; Pachar, Renu B; Poriya, Sangeeta; Mishra, Aalok; Sharma, Rajni; Garg, Anshu

2018-03-01

This study aims to determine the role of mixing techniques of polyether impression materials and efficacy of disinfection on microbial colonization of these impression materials. Polyether impression material was mixed using two methods: First by hand mixing (group I) and second using an automixer (group II) with a total of 100 samples. Four microbial strains were studied, which included Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. After incubation, the bacterial colonies were counted, and then, disinfectant solution was applied. The effect of disinfection solution was evaluated for each specimen. The surface of polyether impression materials mixed with an automixer has less number of voids and overall a smoother surface as compared with the hand-mixed ones. On comparing the disinfection procedures, i.e., specimens without any disinfection and specimens after disinfection, statistically highly significant difference was seen between all the groups. We can conclude that impression mixing procedures are important in determining the surface characteristics of the impression and ultimately the colonization of bacteria and also determine the importance of disinfection on microbial colonization. This study emphasises the deleterious role of nosocomial infections and specific measures that should be taken regarding the prevention of such diseases. Dental impressions are proved to be a source of such infections and may lead to transmission of such diseases. Thus, proper measures should be taken right from the first step of impression taking to minimizing and preventing such kind of contaminations in clinical practice.

Hyperbranched polyether hybrid nanospheres with CdSe quantum dots incorporated for selective detection of nitric oxide

DEFF Research Database (Denmark)

Liu, Shuiping; Jin, Lanming; Chronakis, Ioannis S.

2014-01-01

In this work, hybrid nanosphere vehicles consisting of cadmium selenide quantum dots (CdSe QDs) were synthesized for nitric oxide (NO) donating and real-time detecting. The nanospheres with QDs being encapsulation have spherical outline with dimension of ~127 nm. The fluorescence properties...

The Impact of Polyether Chain Length on the Iron Clearing Efficiency and Physiochemical Properties of Desferrithiocin Analogues

Science.gov (United States)

Bergeron, Raymond J.; Bharti, Neelam; Wiegand, Jan; McManis, James S.; Singh, Shailendra; Abboud, Khalil A.

2010-01-01

(S)-2-(2,4-Dihydroxyphenyl)-4,5-dihydro-4-methyl-4-thiazolecarboxylic acid (2) was abandoned in clinical trials as an iron chelator for the treatment of iron overload disease because of its nephrotoxicity. However, subsequent investigations revealed that replacing the 4′-(HO) of 2 with a 3,6,9-trioxadecyloxy group, ligand 4, increased iron clearing efficiency (ICEa) and ameliorated the renal toxicity of 2. This compelled a closer look at additional polyether analogues, the subject of this work. The 3,6,9,12-tetraoxatridecyloxy analogue of 4, chelator 5, an oil, had twice the ICE in rodents of 4, although its ICE in primates was reduced relative to 4. The corresponding 3,6-dioxaheptyloxy analogue of 2, 6 (a crystalline solid), had high ICEs in both the rodent and primate models. It significantly decorporated hepatic, renal, and cardiac iron, with no obvious histopathologies. These findings suggest that polyether chain length has a profound effect on ICE, tissue iron decorporation, and ligand physiochemical properties. PMID:20232803

The role of lignin sulfonate in flotation of bastnasite from barite

International Nuclear Information System (INIS)

Gerdel, M.A.; Smith, R.W.

1988-01-01

In carboxylate collector flotation of bastnasite from other semisoluble salt type minerals such as barite various modifiers must be added in order to achieve selective flotation. One such modifier is a lignin sulfonate. It may function in part by acting as a sequestrant for metal ions present, preventing autoactivation in the system by metal ions derived from the minerals themselves. It also functions as a depressant for barite than for bastnasite. The authors suggest that the strong depressing action on barite is related to a good fit of the sulfonate into the barite structure

Sulfonated PEEK and fluorinated polymer based blends for fuel cell applications: Investigation of the effect of type and molecular weight of the fluorinated polymers on the membrane's properties

Energy Technology Data Exchange (ETDEWEB)

Inan, Tuelay Y.; Dogan, Hacer; Unveren, Elif E. [The Scientific and Technological Research Council of Turkey (TUBITAK), Marmara Research Center, Chemistry Institute, 41470 Gebze, Kocaeli (Turkey); Eker, Ersoy [Tuerk Demirdoekuem Fabrikalari A.S., 11300 Bozueyuek, Bilecik (Turkey)

2010-11-15

This work clearly demonstrates the effect of the type and molecular weight of the fluorinated polymer of SPEEK/Fluorinated polymer blends for low temperature (<80 C) Fuel Cell Applications. Comparisons with trademarks (e.g., Nafion {sup registered}) suggests that the membranes we have prepared in this study have good compatibility in all application respects. Membranes were prepared by solution casting method from four different fluorinated polymers; poly (vinylidene fluoride) with three different molecular weights (PVDF, M{sub w}: 180.000, M{sub w}: 275.000, M{sub w}: 530.000); Poli(vinylidene fluoride-co-Hexafluoro propylen) (PVDF-HFP M{sub n}:130.000) and sulfonated poly(ether ether ketone) (SPEEK) with sulfonation degree (SD) of 70. The sulfonation degree (SD) of SPEEK was determined by FTIR, {sup 1}H NMR and ion exchange capacity (IEC) measurements. Thermo-oxidative stability and proton conductivity of the membranes were determined by using thermal gravimetric analysis (TGA) and BT-512 BekkTech membrane test systems, respectively. Chemical degradation of SPEEK membranes was investigated via Fenton test. The morphology of the membranes were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Water uptake and proton conductivity values decreased with the addition of fluorinated polymers (PVDF, PVDF-HFP) as expected, but proton conductivity values were still comparable to that of Nafion 117 {sup registered} membrane. Addition of fluorinated polymers improved chemical degradation of the blend membranes in all ratios while addition of PVDF-HFP to the SPEEK70 caused phase separations in all ratios. Methanol permeability value of SPEEK70/PVDF(M{sub w} = 275.000) blend membrane (3.13E-07 (cm{sup 2}/s)) was much lower than Nafion 117 {sup registered} (1.21E-06 (cm{sup 2}/s)). PVDF addition to the SPEEK polymers caused increase in elongation of the membranes. Increase in the molecular weight of the PVDF did not show any effect on

Preparation of a Sulfonated Carbonaceous Material from Lignosulfonate and Its Usefulness as an Esterification Catalyst

Directory of Open Access Journals (Sweden)

Duckhee Lee

2013-07-01

Full Text Available Sulfonated carbonaceous material useful as a solid acid catalyst was prepared from lignosulfonate, a waste of the paper-making industry sulfite pulping process, and characterized by 13C-NMR, FT-IR, TGA, SEM and elemental analysis, etc. The sulfonic acid group density and total density of all acid groups in the sulfonated carbonaceous material was determined by titration to be 1.24 mmol/g and 5.90 mmol/g, respectively. Its catalytic activity in the esterification of cyclohexanecarboxylic acid with anhydrous ethanol was shown to be comparable to that of the ionic exchange resin Amberlyst-15, when they were used in the same amount. In the meantime, the sulfonic acid group was found to be leached out by 26%–29% after it was exposed to hot water (95 °C for 5 h. The catalytic usefulness of the prepared carbonaceous material was investigated by performing esterifications.

THE USE OF CHLOROSULFONIC ACID ON SULFONATION OF cPTFE FILM GRAFTED STYRENE FOR PROTON EXCHANGE MEMBRANE

Directory of Open Access Journals (Sweden)

Yohan Yohan

2010-06-01

Full Text Available Sulfonation of g-ray iradiated and styrene-grafted crosslinked polytetrafluoro ethylene film (cPTFE-g-S film have been done. The aim of the research was to make hydrophyl membrane as proton exchange membrane fuel cell. Sulfonation was prepared by using chlorosulfonic acid in chloroethane under various conditions. The impact of the percentage of grafting, the concentration of chlorosulfonic acid, the reaction time,and the reaction temperature on the properties of sulfonated film were examined. The results show that sulfonation of surface-grafted films was incomplete at room temperature. Increasing concentration of chlorosulfonic acid and reaction temperature accelerate the reaction but they also favor side reactions. These lead to the decrease of the ion-exchange capacity, water uptake, and proton conductivity but the increase of the resistance to oxidation in a perhydrol solution. The resulted cPTFE-g-SS membraneis stabile in a H2O2 30% solution for 20 h.   Keywords: Chorosulfonic acid, sulfonation, PTFE film, proton excange membrane.

Biocompatible magnetic and molecular dual-targeting polyelectrolyte hybrid hollow microspheres for controlled drug release.

Science.gov (United States)

Du, Pengcheng; Zeng, Jin; Mu, Bin; Liu, Peng

2013-05-06

Well-defined biocompatible magnetic and molecular dual-targeting polyelectrolyte hybrid hollow microspheres have been accomplished via the layer-by-layer (LbL) self-assembly technique. The hybrid shell was fabricated by the electrostatic interaction between the polyelectrolyte cation, chitosan (CS), and the hybrid anion, citrate modified ferroferric oxide nanoparticles (Fe3O4-CA), onto the uniform polystyrene sulfonate microsphere templates. Then the magnetic hybrid core/shell composite particles were modified with a linear, functional poly(ethylene glycol) (PEG) monoterminated with a biotargeting molecule (folic acid (FA)). Afterward the dual targeting hybrid hollow microspheres were obtained after etching the templates by dialysis. The dual targeting hybrid hollow microspheres exhibit exciting pH response and stability in high salt-concentration media. Their pH-dependent controlled release of the drug molecule (anticancer drug, doxorubicin (DOX)) was also investigated in different human body fluids. As expected, the cell viability of the HepG2 cells which decreased more rapidly was treated by the FA modified hybrid hollow microspheres rather than the unmodified one in the in vitro study. The dual-targeting hybrid hollow microspheres demonstrate selective killing of the tumor cells. The precise magnetic and molecular targeting properties and pH-dependent controlled release offers promise for cancer treatment.

Electronic Conductivity of Polypyrrole−Dodecyl Benzene Sulfonate Complexes

DEFF Research Database (Denmark)

West, Keld; Bay, Lasse; Nielsen, Martin Meedom

2004-01-01

The electronic conductivity of the electroactive polymer polypyrrole-dodecyl benzene sulfonate (PPy-DBS) has been characterized as function of the redox level. The polymer was synthesized with different isomers of the dopant anions: the common mixed DBS tenside and three well-defined synthetic...

Organic monolith frits encased in polyether ether ketone tubing with improved durability for liquid chromatography.

Science.gov (United States)

Park, Sin Young; Cheong, Won Jo

2015-09-01

This study introduces a preparation method for polymer-encased monolith frits with improved durability for liquid chromatography columns. The inner surface of the polyether ether ketone tubing is pretreated with sulfuric acid in the presence of catalysts (vanadium oxide and sodium sulfate). The tubing was rinsed with water and acetone, flushed with nitrogen, and treated with glycidyl methacrylate. After washing, the monolith reaction mixture composed of lauryl methacrylate, ethylene glycol dimethacrylate, initiator, and porogenic solvent was filled in the tubing and subjected to in situ polymerization. The tubing was cut into thin slices and used as frits for microcolumns. To check their durability, the frit slices were placed in a vial and a heavy impact was applied on the vial by a vortex mixer for various periods. The frits made in the presence of catalysts were found to be more durable than those made without catalysts. Furthermore, when the monolith-incorporated tubing was used as a chromatography column, the column prepared in the presence of catalysts resulted in a better separation efficiency. The separation performance of the columns installed with the polyether ether ketone encased monolith frits was comparable to that of the columns installed with the commercial stainless-steel screen frits. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Undoped poly (phenyl sulfone) for radiation detection

International Nuclear Information System (INIS)

Nakamura, Hidehito; Shirakawa, Yoshiyuki; Sato, Nobuhiro; Kitamura, Hisashi; Takahashi, Sentaro

2015-01-01

Undoped aromatic ring polymers are potential scintillation materials. Here, we characterise poly (phenyl sulfone) (PPSU) for radiation detection. The amber-coloured transparent resin emits bluish-white fluorescence with 390-nm maximum. It has an excitation maximum of 340 nm, and has a density of 1.29 g/cm 3 . The effective refractive index based on its emission spectrum is 1.75. The light yield is almost equal to that of poly (ethylene terephthalate), which is a transparent resin. These results demonstrate that PPSU can be used as a component substrate in polymer blends for altering optical characteristics. - Highlights: • Poly (phenyl sulfone) (PPSU) has suitable characteristics as a scintillation material. • PPSU is an amber-coloured transparent resin that emits bluish white fluorescence with 390-nm maximum. • The 1.75 effective refractive index over the emission spectrum is relatively high. • The light yield is 0.95 times that of poly (ethylene terephthalate), which is a transparent resin. • PPSU can potentially alter optical characteristics in polymer blends

Partial sulfonation of PVdF-co-HFP: A preliminary study and characterization for application in direct methanol fuel cell

International Nuclear Information System (INIS)

Das, Suparna; Kumar, Piyush; Dutta, Kingshuk; Kundu, Patit Paban

2014-01-01

Highlights: • Synthesis of sulfonated PVdF-co-HFP by reacting with chlorosulfonic acid. • Maximum degree of sulfonation and best properties were obtained for 7 h reaction. • A maximum water uptake value of 20% was obtained. • A maximum IEC value of 0.42 meq g −1 was obtained. • A methanol permeability of 2.44 × 10 −7 cm 2 s −1 was obtained. - Abstract: Sulfonation of PVdF-co-HFP was conducted by treating the copolymer with chlorosulfonic acid. The efficiency of this sulfonated copolymer towards application as a polymer electrolyte membrane in direct methanol fuel cell (DMFC) was evaluated. For this purpose, we determined the thermal stability, water uptake, ion exchange capacity (IEC), methanol crossover, and proton conductivity of the prepared membranes as functions of duration and degree of sulfonation. The characteristic aromatic peaks obtained in the FT-IR spectra confirmed the successful sulfonation of PVdF-co-HFP. The effect of sulfonation on the semi-crystalline nature of pure PVdF-co-HFP was determined from XRD analysis. Water uptake results indicated that a sulfonation time of 7 h produced maximum water uptake value of about 20%, with a corresponding IEC and proton conductivity values of about 0.42 meq g −1 and 0.00375 S cm −1 respectively. The maximum current density was recorded to be 30 mA cm −2 at 0.2 V potential

IR Laser Ablative Degradation of Poly(phenylene ether sulfone): Deposition of Films Containing Sulfone, Sulfoxide and Sulfide Groups

Czech Academy of Sciences Publication Activity Database

Blazevska-Gilev, J.; Bastl, Zdeněk; Šubrt, Jan; Stopka, Pavel; Pola, Josef

2009-01-01

Roč. 94, č. 2 (2009), s. 196-200 ISSN 0141-3910 R&D Projects: GA AV ČR IAA400720619 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40400503; CEZ:AV0Z40320502 Keywords : laser ablation * laser-induced degradation * poly(1,4-phenylene ether-sulfone) Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 2.154, year: 2009

Dielectric relaxations and conduction mechanisms in polyether-clay composite polymer electrolytes under high carbon dioxide pressure.

Science.gov (United States)

Kitajima, Shunsuke; Bertasi, Federico; Vezzù, Keti; Negro, Enrico; Tominaga, Yoichi; Di Noto, Vito

2013-10-21

The composite material P(EO/EM)-Sa consisting of synthetic saponite (Sa) dispersed in poly[ethylene oxide-co-2-(2-methoxyethoxy)ethyl glycidyl ether] (P(EO/EM)) is studied by "in situ" measurements using broadband electrical spectroscopy (BES) under pressurized CO2 to characterize the dynamic behavior of conductivity and the dielectric relaxations of the ion host polymer matrix. It is revealed that there are three dielectric relaxation processes associated with: (I) the dipolar motions in the short oxyethylene side chains of P(EO/EM) (β); and (II) the segmental motion of the main chains comprising the polyether components (αfast, αslow). αslow is attributed to the slow α-relaxation of P(EO/EM) macromolecules, which is hindered by the strong coordination interactions with the ions. Two conduction processes are observed, σDC and σID, which are attributed, respectively, to the bulk conductivity and the interdomain conductivity. The temperature dependence of conductivity and relaxation processes reveals that αfast and αslow are strongly correlated with σDC and σID. The "in situ" BES measurements under pressurized CO2 indicate a fast decrease in σDC at the initial CO2 treatment time resulting from the decrease in the concentration of polyether-M(n+) complexes, which is driven by the CO2 permeation. The relaxation frequency (fR) of αslow at the initial CO2 treatment time increases and shows a steep rise with time with the same behavior of the αfast mode. It is demonstrated that the interactions between polyether chains of P(EO/EM) and cations in the polymer electrolyte layers embedded in Sa are probably weakened by the low permittivity of CO2 (ε = 1.08). Thus, the formation of ion pairs in the polymer electrolyte domains of P(EO/EM)-Sa occurs, with a corresponding reduction in the concentration of ion carriers.

Andrographolide sulfonate ameliorates lipopolysaccharide-induced acute lung injury in mice by down-regulating MAPK and NF-κB pathways.

Science.gov (United States)

Peng, Shuang; Hang, Nan; Liu, Wen; Guo, Wenjie; Jiang, Chunhong; Yang, Xiaoling; Xu, Qiang; Sun, Yang

2016-05-01

Acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) is a severe, life-threatening medical condition characterized by widespread inflammation in the lungs, and is a significant source of morbidity and mortality in the patient population. New therapies for the treatment of ALI are desperately needed. In the present study, we examined the effect of andrographolide sulfonate, a water-soluble form of andrographolide (trade name: Xi-Yan-Ping Injection), on lipopolysaccharide (LPS)-induced ALI and inflammation. Andrographolide sulfonate was administered by intraperitoneal injection to mice with LPS-induced ALI. LPS-induced airway inflammatory cell recruitment and lung histological alterations were significantly ameliorated by andrographolide sulfonate. Protein levels of pro-inflammatory cytokines in bronchoalveolar lavage fluid (BALF) and serum were reduced by andrographolide sulfonate administration. mRNA levels of pro-inflammatory cytokines in lung tissue were also suppressed. Moreover, andrographolide sulfonate markedly suppressed the activation of mitogen-activated protein kinase (MAPK) as well as p65 subunit of nuclear factor-κB (NF-κB). In summary, these results suggest that andrographolide sulfonate ameliorated LPS-induced ALI in mice by inhibiting NF-κB and MAPK-mediated inflammatory responses. Our study shows that water-soluble andrographolide sulfonate may represent a new therapeutic approach for treating inflammatory lung disorders.

Andrographolide sulfonate ameliorates lipopolysaccharide-induced acute lung injury in mice by down-regulating MAPK and NF-κB pathways

Directory of Open Access Journals (Sweden)

Shuang Peng

2016-05-01

Full Text Available Acute lung injury (ALI or acute respiratory distress syndrome (ARDS is a severe, life-threatening medical condition characterized by widespread inflammation in the lungs, and is a significant source of morbidity and mortality in the patient population. New therapies for the treatment of ALI are desperately needed. In the present study, we examined the effect of andrographolide sulfonate, a water-soluble form of andrographolide (trade name: Xi-Yan-Ping Injection, on lipopolysaccharide (LPS-induced ALI and inflammation. Andrographolide sulfonate was administered by intraperitoneal injection to mice with LPS-induced ALI. LPS-induced airway inflammatory cell recruitment and lung histological alterations were significantly ameliorated by andrographolide sulfonate. Protein levels of pro-inflammatory cytokines in bronchoalveolar lavage fluid (BALF and serum were reduced by andrographolide sulfonate administration. mRNA levels of pro-inflammatory cytokines in lung tissue were also suppressed. Moreover, andrographolide sulfonate markedly suppressed the activation of mitogen-activated protein kinase (MAPK as well as p65 subunit of nuclear factor-κB (NF-κB. In summary, these results suggest that andrographolide sulfonate ameliorated LPS-induced ALI in mice by inhibiting NF-κB and MAPK-mediated inflammatory responses. Our study shows that water-soluble andrographolide sulfonate may represent a new therapeutic approach for treating inflammatory lung disorders.

Study on the radiation effect of polyether-urethane in the γ radiation field

International Nuclear Information System (INIS)

Huang, W.; Xu, Y.S.; Chen, X.J.; Gao, X.L.; Tang, Y.M.; Wang, H.Y.

2005-01-01

Polyether-urethane (ETPU) is made up of hard and soft sections. The hard section which is mainly in crystalline state is carbamate, and soft section which is in amorphous state is polyether. Reference reports in detail the degradation of polyurethane deduced by thermal oxidation. The result shows that the thermal degradation begins with the caramate group. The polyalcohol is the weak point of polyurethane degradation in the presence of oxygen. Similarly, the anti-radiation of carbamate (hard section) is superior to that of polyether (soft section) In our former work, we have discussed the degradation of ETPU foam deduced by electron beam. And we have studied the composition and yields of gas products from the radiation degradation, and the changes of the thermal property, micro-phase separation and the microscopic form of irradiated samples. In this article, the radiation effect of γ-ray on polyether-urethane foam was studied. The gas products from irradiated samples were analyzed quantitatively and qualitatively by gas chromatography. Compared with the standard gas, the gas products are H 2 , CO 2 , CH 4 , C 2 H 6 and so on. Among these gases, the gas yield of CO 2 is the most, that of H 2 is less, and those of CH 4 and C 2 H 6 are the least. The yields of different sorts of gases increase with the dose raising. Furthermore, the radiation degradation of the sample is the most serious in the oxygen atmosphere, less in air, and the least in vacuum. ESR of ETPU sample irradiated by γ ray in vacuum is shown in figurel, which is determined at the room temperature, and ESR of polyester-urethane (ESPU) irradiated by UV light is shown in figure 2. It can be seen from these two figures that the spectral shape is different. The radical peak in the sample irradiated by UV light is symmetrical, which indicates that there is only one sort of radical; but that is not the truth to the sample irradiated by gamma ray for its asymmetrical radical peak. According to the results of

Partial molar volumes of organic solutes in water. XXVII. Two aliphatic polyethers (triglyme, tetraglyme) at temperatures T = 298–573 K and pressures up to 30 MPa

International Nuclear Information System (INIS)

Cibulka, Ivan

2016-01-01

Highlights: • Standard molar volumes of two linear aliphatic polyethers in water are presented. • Data were obtained in the range T from (298 to 573) K and p up to 30 MPa. • Data combined with those obtained previously are analyzed and compared with standard molar volumes of cyclic ethers. - Abstract: Densities of dilute aqueous solutions of two linear aliphatic polyethers: 2,5,8,11-tetraoxadodecane (triethylene glycol dimethyl ether, triglyme) and 2,5,8,11,14-pentaoxapentadecane (tetraethylene glycol dimethyl ether, tetraglyme), measured in the temperature range from (298 to 573) K and at pressures up to 30 MPa using an automated flow vibrating-tube densimeter are reported. Standard molar volumes were evaluated from the measured data. The present values complement previous measurements performed for the title polyethers at atmospheric pressure in the temperature range from (278 to 343) K and extend the knowledge to temperature and pressure ranges in which the data on standard molar volumes for lower members of the homologous series (monoglyme, diglyme) are already available.

An investigation of proton conductivity of binary matrices sulfonated ...

Indian Academy of Sciences (India)

to their potential applications in proton exchange membrane fuel cells (PEMFCs) ... is highly sulfonated and has high water uptake property.11,12 The proton conductivity ... SPSU membranes have lower gas permeability and liquid. (water and ...

Improving the Conductivity of Sulfonated Polyimides as Proton Exchange Membranes by Doping of a Protic Ionic Liquid

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Bor-Kuan Chen

2014-10-01

Full Text Available Proton exchange membranes (PEMs are a key component of a proton exchange membrane fuel cell. Sulfonated polyimides (SPIs were doped by protic ionic liquid (PIL to prepare composite PEMs with substantially improved conductivity. SPIs were synthesized from diamine, 2,2-bis[4-(4-amino-phenoxyphenyl]propane (BAPP, sulfonated diamine, 4,4'-diamino diphenyl ether-2,2'-disulfonic acid (ODADS and aromatic anhydride. BAPP improved the mechanical and thermal properties of SPIs, while ODADS enhanced conductivity. A PIL, 1-vinylimidazolium trifluoromethane-sulfonate ([VIm][OTf], was utilized. [VIm][OTf] offered better conductivity, which can be attributed to its vinyl chemical structure attached to an imidazolium ring that contributed to ionomer-PIL interactions. We prepared sulfonated polyimide/ionic liquid (SPI/IL composite PEMs using 50 wt% [VIm][OTf] with a conductivity of 7.17 mS/cm at 100 °C, and in an anhydrous condition, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride (DSDA was used in the synthesis of SPIs, leading to several hundred-times improvement in conductivity compared to pristine SPIs.

Effect of sodium aromatic sulfonate group in anionic polymer dispersant on the viscosity of coal-water mixtures

Energy Technology Data Exchange (ETDEWEB)

Toshio Kakui; Hidehiro Kamiya [Lion Corporation, Tokyo (Japan). Chemicals Research Laboratories, Chemicals Division

2004-06-01

This paper focused on the effect of sodium aromatic sulfonate in anionic polymer dispersants on the viscosity of coal-water mixtures (CWMs) with a Tatung coal powder. To determine the optimum molecular structure of a polymer dispersant for the minimum viscosity of a CWM, various anionic co-polymers with different hydrophilic and hydrophobic groups or different molecular weights were prepared, using various types of monomers. Anionic co-polymers with sodium aromatic sulfonate, such as sodium styrene-sulfonate and sodium naphthalene-sulfonate, reduced the viscosity of dense CWMs. In particular, a co-polymer of sodium styrene-sulfonate and sodium acrylate with a molar ratio of 70:30 and a molecular weight of {approximately} 10 000 gave the minimum viscosity of a 70 wt % CWM. To obtain a low viscosity for a CWM, a large electrostatic repulsive force with an absolute value of the zeta potential of the coal particles of {gt} 70 mV and {gt} 6.5 mg/g of adsorbed polymer on the coal surface were needed. The mixture of sodium polystyrene-sulfonate and sodium polyacrylate with a weight ratio of 50:50 also gave a low viscosity of 70 wt % CWM. On the basis of the results, the adsorption behavior of polymer dispersants on the coal surface is examined by measuring the wettability of coal powder pellets. 27 refs., 8 figs., 3 tabs.

Radiation degradation of polyether-polyurethane induced by E-beams

International Nuclear Information System (INIS)

Huang Wei; Xu Yunshu; Chen Xiaojun; Gao Xiaoling; Xiong Jie; Fu Yibei

2006-01-01

Polyether-urethane samples were irradiated at the dose range from 10kGy to 2000 kGy by 2 MeV electron beams. Volatile species from the polymer degradation were analyzed quantitatively and qualitatively with GC/MS. Thermal properties and micro-phase separation of the samples were examined by TG and the morphology was studied by TEM and SEM. The irradiated polyether-polyurethane evolves mainly CO 2 along with H 2 , CH 4 and C 2 H 6 etc. The quantity of CO 2 increased with the dose during irradiations of up to 1500 kGy. And the H 2 yield had a trend of increase, while the CH 4 yield rose to a maximum before it decreased to a stable level. Because the soft and hard segments on ETPU chains are thermally compatible, phase separation takes place in its inner part. DTG analysis of the irradiated samples showed that the samples went to phase separations at a thermal decomposition peak of 325-335 degree C, which stands for the phase separation of the hard segment, and at 470-485 degree C for the soft segment. The lower temperature peak was stronger than the high temperature peak, and this indicated different thermal stabilities of the soft and hard segments. TEM images of the samples indicated that excellent compatibility of the hard and soft segments in pristine and the samples irradiated to low doses. It could be clearly seen from the TEM images that there were two phases in the sample irradiated to over 800 kGy. The electrons broke the hydrogen bond of >NH and >C=O on the hard segment and -O- on the soft part. Due to the disappearance of hydrogen bond, compatibility degree of the soft and hard segments reduced, phase range of the soft segment increased, hence the obvious phase separation. SEM images of the irradiated samples illustrated that spherical pores of polyurethane collapsed to form cracks at low doses, and they were damaged seriously at high doses. SEM images of the samples irradiated under constant stress indicated that elasticity of the sample was seriously

Synthesis and characterization of sulfonated polyesters derived from glycerol; Sintese e caracterizacao de poliesteres sulfonados obtidos a partir do glicerol

Energy Technology Data Exchange (ETDEWEB)

Fiuza, R.A.; Jose, N.M.; Boaventura, J.S. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Fiuza, R.P. [Universidade Federal da Bahia (EP/UFBA), Salvador, BA (Brazil). Escola Politecnica. Curso de Mestrado em Engenharia Quimica

2010-07-01

In this work were synthesized polyesters from glycerol and acid sulfonated phthalic previously. The materials were characterized by DSC, TGA, FTIR, SEM, XRD and XRF. The results showed effective sulfonation of phthalic acid. The presence of sulfonic groups promoted strong changes in the crystallinity of the new material makes the lens. The polyesters made from phthalic acid sulfonated combine characteristics such as heat resistance and groups that drivers potentiate the electrolyte for application in fuel cells proton exchange membrane and also for gas separation. (author)

Sulfonic-based precursors (SAPs for silica mesostructures: Advances in synthesis and applications

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Sadegh Rostamnia*

2016-01-01

Full Text Available Sulfonic acid-based precursors (SAP play an important role in tailoring mesoporous silica’s and convert them to a solid acid catalyst with a Bronsted-type nature. These kinds of solid acids contribute to sustainable and green chemistry by their heterogeneous, recyclable, and high efficiency features. Therefore, knowing the properties and reactivity of SAPs can guide us to manufacture a sulfonated mesostructures compatible with reaction type and conditions. In the present review, some of the important SAPs, their reactivity and mechanism of functionalization are discussed.

Synthesis and ATRP of novel fluorinated aromatic monomer with pendant sulfonate group

DEFF Research Database (Denmark)

Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

2013-01-01

Novel, fluorinated monomer with pendant sulfonate group was synthesized utilizing a two-step derivatization of 2,3,4,5,6-pentafluorostyrene (FS). The first step was a nucleophilic substitution of the fluorine atom in para position by hydroxyl group followed by sulfopropylation. The monomer...... was polymerized under aqueous ATRP conditions to yield phenyl-fluorinated aromatic homopolymer bearing pendant sulfonates on each repeating unit. Furthermore, this polymer was used as macroinitiator for the ATRP of poly(ethylene glycol) methacrylate. The polymers were characterized by 1H NMR, SEC and FTIR...

The host cell sulfonation pathway contributes to retroviral infection at a step coincident with provirus establishment.

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James W Bruce

2008-11-01

Full Text Available The early steps of retrovirus replication leading up to provirus establishment are highly dependent on cellular processes and represent a time when the virus is particularly vulnerable to antivirals and host defense mechanisms. However, the roles played by cellular factors are only partially understood. To identify cellular processes that participate in these critical steps, we employed a high volume screening of insertionally mutagenized somatic cells using a murine leukemia virus (MLV vector. This approach identified a role for 3'-phosphoadenosine 5'-phosphosulfate synthase 1 (PAPSS1, one of two enzymes that synthesize PAPS, the high energy sulfate donor used in all sulfonation reactions catalyzed by cellular sulfotransferases. The role of the cellular sulfonation pathway was confirmed using chemical inhibitors of PAPS synthases and cellular sulfotransferases. The requirement for sulfonation was mapped to a stage during or shortly after MLV provirus establishment and influenced subsequent gene expression from the viral long terminal repeat (LTR promoter. Infection of cells by an HIV vector was also shown to be highly dependent on the cellular sulfonation pathway. These studies have uncovered a heretofore unknown regulatory step of retroviral replication, have defined a new biological function for sulfonation in nuclear gene expression, and provide a potentially valuable new target for HIV/AIDS therapy.

Bis-sulfonic Acid Ionic Liquids for the Conversion of Fructose to 5-Hydroxymethyl-2-furfural

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Sangho Koo

2012-10-01

Full Text Available Homogenous bis-sulfonic acid ionic liquids (1 mol equiv. in DMSO (10 mol equiv. at 100 °C efficiently mediated the conversion of D-fructose into 5-hydroxymethyl-2-furfural in 75% isolated yield, which was roughly a 10% increment compared to the case of the mono-sulfonic acid ionic liquids.

Crosslinked wholly aromatic polyether membranes based on quinoline derivatives and their application in high temperature polymer electrolyte membrane fuel cells

Science.gov (United States)

Kallitsis, K. J.; Nannou, R.; Andreopoulou, A. K.; Daletou, M. K.; Papaioannou, D.; Neophytides, S. G.; Kallitsis, J. K.

2018-03-01

An AB type difunctional quinoline based monomer bearing a pentafluorophenyl unit combined with a phenol functionality is being synthesized and homopolymerized to create linear aromatic polyethers as polymer electrolytes for HT-PEM FCs applications. Several conditions are tested for the optimized synthesis of the monomer and homopolymer. Additionally, covalent crosslinking through aromatic polyether bond formation enables the creation of wholly aromatic crosslinked polymeric electrolyte membranes. More specifically, the perfluorophenyl units are crosslinked with other hydroxyl end functionalized moieties, providing membranes with enhanced chemical and mechanical properties that are moreover easily doped with phosphoric acid even at ambient temperatures. All membranes are evaluated for their structural and thermal characteristics and their doping ability with phosphoric acid. Selected crosslinked membranes are further tested in terms of their single cell performance at the temperature range 160 °C-200 °C showing promising performance and high conductivity values even up to 0.2 S cm-1 in some cases.

Synthesis and properties of sulfonated copoly(phthalazinone ether imides) as electrolyte membranes in fuel cells

Energy Technology Data Exchange (ETDEWEB)

Pan Haiyan [Department of Polymer Science and Materials, Dalian University of Technology, Dalian 116012 (China); Institute of Functional Polymers, School of Materials Science and Engineering, Tongji University, Shanghai 200092 (China); Zhu Xiuling, E-mail: zhuxl@dlut.edu.c [Department of Polymer Science and Materials, Dalian University of Technology, Dalian 116012 (China); Jian Xigao [Department of Polymer Science and Materials, Dalian University of Technology, Dalian 116012 (China)

2010-01-01

A new series of six-member sulfonated copolyimides (SPIs) were prepared by one-step solution copolycondensation from 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA), 1,2-dihydro-2-(4-amino-2-sulfophenyl)-4- [4-(4-amino-2-sulfonphenoxy)-phenyl] (2H)phthalazin-1-one (S-DHPZDA), 4,4'-bis(4-aminophenoxy) biphenyl (BAPB) and 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-(aminophenoxyl)phenyl)] (2H)phthalazin-1-one (DHPZDA). The sulfonation degree (DS) of the SPIs was controlled by the mol ratio of the sulfonated diamine and non-sulfonated diamine. The obtained SPI membranes had excellent thermal stability, high mechanical property and proton conductivity as well as low methanol permeability. The tensile strength of the SPI membranes was ranging from 54.7 to 98.1 MPa, which was much higher than that of Nafion. The SPI membranes exhibited high proton conductivity (sigma) and low methanol permeability ranged from 10{sup -3} to 10{sup -2} S/cm and 10{sup -8} to 10{sup -7} cm{sup 2}/s depending on the DS of the polymers, respectively.

Salinomycin, A Polyether Ionophoric Antibiotic, Inhibits Adipogenesis

Science.gov (United States)

Szkudlarek-Mikho, Maria; Saunders, Rudel A.; Yap, Sook Fan; Ngeow, Yun Fong; Chin, Khew-Voon

2012-01-01

The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor γ. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy. PMID:23123626

Toxicokinetics of perfluorooctane sulfonate in rainbow trout (Oncorhynchus mykiss)

Science.gov (United States)

Rainbow trout (Oncorhynchus mykiss) confined to respirometer-metabolism chambers were dosed with perfluorooctane sulfonate (PFOS) by intra-arterial injection and sampled to obtain concentration time-course data for plasma, and either urine or expired water. The data were then an...

Cloning and Characterization of the Polyether Salinomycin Biosynthesis Gene Cluster of Streptomyces albus XM211

Science.gov (United States)

Jiang, Chunyan; Wang, Hougen; Kang, Qianjin; Liu, Jing

2012-01-01

Salinomycin is widely used in animal husbandry as a food additive due to its antibacterial and anticoccidial activities. However, its biosynthesis had only been studied by feeding experiments with isotope-labeled precursors. A strategy with degenerate primers based on the polyether-specific epoxidase sequences was successfully developed to clone the salinomycin gene cluster. Using this strategy, a putative epoxidase gene, slnC, was cloned from the salinomycin producer Streptomyces albus XM211. The targeted replacement of slnC and subsequent trans-complementation proved its involvement in salinomycin biosynthesis. A 127-kb DNA region containing slnC was sequenced, including genes for polyketide assembly and release, oxidative cyclization, modification, export, and regulation. In order to gain insight into the salinomycin biosynthesis mechanism, 13 gene replacements and deletions were conducted. Including slnC, 7 genes were identified as essential for salinomycin biosynthesis and putatively responsible for polyketide chain release, oxidative cyclization, modification, and regulation. Moreover, 6 genes were found to be relevant to salinomycin biosynthesis and possibly involved in precursor supply, removal of aberrant extender units, and regulation. Sequence analysis and a series of gene replacements suggest a proposed pathway for the biosynthesis of salinomycin. The information presented here expands the understanding of polyether biosynthesis mechanisms and paves the way for targeted engineering of salinomycin activity and productivity. PMID:22156425

Polyether ether ketone implants achieve increased bone fusion when coated with nano-sized hydroxyapatite

DEFF Research Database (Denmark)

Johansson, Pär; Jimbo, Ryo; Naito, Yoshihito

2016-01-01

Polyether ether ketone (PEEK) possesses excellent mechanical properties similar to those of human bone and is considered the best alternative material other than titanium for orthopedic spine and trauma implants. However, the deficient osteogenic properties and the bioinertness of PEEK limit its...... fields of application. The aim of this study was to limit these drawbacks by coating the surface of PEEK with nano-scaled hydroxyapatite (HA) minerals. In the study, the biological response to PEEK, with and without HA coating, was investigated. Twenty-four screw-like and apically perforated implants...

Evaluation of the efficiency of silicone polyether additives as foam inhibitor in crude oil

International Nuclear Information System (INIS)

Fraga, Assis K.; Santos, Raquel F.; Mansur, Claudia R.E.

2011-01-01

This work evaluates the chemical and physico-chemical properties of commercial anti-foam products based on silicone polyethers along with their efficiency in inhibiting foaming. The commercial surfactants were characterized by nuclear magnetic resonance (NMR) spectroscopy, size exclusion chromatography (SEC), determination of solubility in different solvents and measurement of the surface and interfacial tensions. A method to test the formation of foam in oil was used to mimic the operating conditions in gas-oil separators. The results show that the most polar additive was the most efficient in breaking up the foam. (author)

The radiation chemistry of aqueous solutions of sodium 9,10-anthraquinone-2-sulfonate

International Nuclear Information System (INIS)

Burchill, C.E.; Smith, D.M.; Charlton, J.L.

1976-01-01

The 60 Co γ-radiolysis of aqueous solutions of sodium 9,10-anthraquinone-2-sulfonate has been studied in acidic, unbuffered, and alkaline conditions and with addition of N 2 O and 2-propanol. Mechanisms are proposed to account for the yields of H 2 O 2 and hydroxylated anthraquinone sulfonates. In neutral solution, in the absence of O 2 , the OH and e - adducts undergo preferential cross termination. Reduction of the OH adduct leads to dehydration and regeneration of the quinone. (author)

Preparation and Properties of Polymer/Vermiculite Hybrid Superabsorbent Reinforced by Fiber for Enhanced Oil Recovery

Directory of Open Access Journals (Sweden)

Fayang Jin

2014-01-01

Full Text Available A series of polymer/clay hybrid superabsorbent composites (SACFs comprising acrylamide, acrylic acid, sodium 2-acrylamido-tetradecyl sulfonate, fiber, and vermiculite by in situ intercalation and exfoliated method was successfully synthesized. The structure of SACFs was characterized by IR, SXRD, and SEM measurements. Much notable absorbency for SACF-2 was observed compared to that for SACF-1 in the absence of hydrophobic group in the high cationic solution due to the alkyl carbon chain and sulfonic acid group of hydrophobic moistures protecting the cations from attacking the carboxylate groups. What is more, high temperature fiber which acts as bridge connection for the polymeric network structure enhanced both toughness and strength for SACF-4 in the harsh conditions. At the total dissolved substance of 212000 mg/L for Tarim Basin injected water and the temperature of 120°C, desired absorbency as well as water retaining property for SACF-4 was observed during the long period of thermal ageing. Core flooding experiments demonstrated that SACFs could migrate as amoeba in the porous medium and accumulated in the narrow channel to adjust injection profile, promoting the subsequent water diverting into the unswept zones. Finally, characteristic parameters for SACFs calculated from flooding experiment further confirmed these polymer/clay hybrid composites reinforced by fiber would have robust application in the mature oilfield for profile control.

A Cell-Based Screen Reveals that the Albendazole Metabolite, Albendazole Sulfone, Targets Wolbachia

Science.gov (United States)

Bray, Walter M.; White, Pamela M.; Ruybal, Jordan; Lokey, R. Scott; Debec, Alain; Sullivan, William

2012-01-01

Wolbachia endosymbionts carried by filarial nematodes give rise to the neglected diseases African river blindness and lymphatic filariasis afflicting millions worldwide. Here we identify new Wolbachia-disrupting compounds by conducting high-throughput cell-based chemical screens using a Wolbachia-infected, fluorescently labeled Drosophila cell line. This screen yielded several Wolbachia-disrupting compounds including three that resembled Albendazole, a widely used anthelmintic drug that targets nematode microtubules. Follow-up studies demonstrate that a common Albendazole metabolite, Albendazole sulfone, reduces intracellular Wolbachia titer both in Drosophila melanogaster and Brugia malayi, the nematode responsible for lymphatic filariasis. Significantly, Albendazole sulfone does not disrupt Drosophila microtubule organization, suggesting that this compound reduces titer through direct targeting of Wolbachia. Accordingly, both DNA staining and FtsZ immunofluorescence demonstrates that Albendazole sulfone treatment induces Wolbachia elongation, a phenotype indicative of binary fission defects. This suggests that the efficacy of Albendazole in treating filarial nematode-based diseases is attributable to dual targeting of nematode microtubules and their Wolbachia endosymbionts. PMID:23028321

Sulfonated copolyimide membranes derived from a novel diamine monomer with pendant benzimidazole groups for fuel cells

DEFF Research Database (Denmark)

Li, Wei; Guo, Xiaoxia; Aili, David

2015-01-01

. A series of sulfonated copolyimides (SPI) are prepared via random copolymerizatio of 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) with a new diamine monomer with pendant benzimidazole groups, 2,2'-bis(4-(1H-benzo[d]imidazol-2-yl)phenoxy)benzidine (BIPOB), and a sulfonated diamine monomer 4,4'-bis...

Study of radiation grafted and sulfonated poly(tetrafluoroethylene-co-hexafluoropropylene), FEP, membranes

International Nuclear Information System (INIS)

Mohamed Mahmoud Nasef; Hamdani Saidi; Hussin Mohd Nor

1999-01-01

Radiation grafted and sulfonated FEP membranes were prepared by radiation-induced grafting of styrene onto poly(tetrafluoroethylene-co-hexafluoropropylene) films at room temperature and subsequently sulfonated. The membrane composition was controlled via variation of the grafting conditions such as type of diluent, irradiation dose, dose rate and monomer concentration. The membrane properties such as water uptake, ion exchange capacity and ionic conductivity were found to be strongly dependent upon the degree of grafting. The membranes were shown to have a good combination of physico-chemical properties, which made them promising for development of low cost proton exchange membranes

Semi-fluorinated sulfonated polyimide membranes with enhanced proton selectivity and stability for vanadium redox flow batteries

International Nuclear Information System (INIS)

Li, Jinchao; Liu, Suqin; He, Zhen; Zhou, Zhi

2016-01-01

A series of semi-fluorinated sulfonated polyimides (6F-SPIs) are designed and synthesized via a one-step high-temperature polycondensation reaction. The sulfonation degrees of 6F-SPIs are controlled through changing the ratio of sulfonated diamine to non-sulfonated diamine in the casting solution. The physico-chemical properties and single cell performance of 6F-SPI membranes are thoroughly evaluated and compared to a non-fluorinated SPI membrane (6H-SPI-50) and a Nafion 115 membrane. The results show that the designed 6F-SPI membrane with a 50% sulfonation degree (6F-SPI-50) possesses the highest proton selectivity (1.613 × 10 5 S min cm −3 ) among all tested membranes. Besides, the 6F-SPI-50 membrane exhibits a promising performance for vanadium redox flow batteries (VRFBs), showing higher coulombic efficiencies (96.90–99.20%) and energy efficiencies (88.25–64.80%) than the Nafion 115 membrane (with coulombic efficiencies of 90.60–96.70% and energy efficiencies of 81.04–60.10%) at the current densities ranging from 20 to 100 mA cm −2 . Moreover, the 6F-SPI-50 membrane shows excellent chemical stability in the VRFB system. This work paves the way for the development of a new class of 6F-SPI membranes for the VRFB application.

In vivo and in vitro degradation of poly(ether ester) block copolymers based on poly(ethylene glycol) and poly(butylene terephthalate

NARCIS (Netherlands)

Deschamps, A.A.; van Apeldoorn, Aart A.; Hayen, H.; de Bruijn, Joost Dick; Karst, U.; Grijpma, Dirk W.; Feijen, Jan

2004-01-01

Two in vivo degradation studies were performed on segmented poly(ether ester)s based on polyethylene glycol (PEG) and poly(butylene terephthalate) (PBT) (PEOT/PBT). In a first series of experiments, the in vivo degradation of melt-pressed discs of different copolymer compositions were followed up

Sulfonated macro-RAFT agents for the surfactant-free synthesis of cerium oxide-based hybrid latexes

NARCIS (Netherlands)

Garnier, J.; Warnant, J.; Lacroix-Desmazes, P.; Dufils, P.E.; Vinas, J.; Herk, van A.M.

2013-01-01

Three types of amphiphatic macro-RAFT agents were employed as compatibilizers to promote the polymerization reaction at the surface of nanoceria for the synthesis of CeO2-based hybrid latexes. Macro-RAFT copolymers and terpolymers were first synthesized employing various combinations of butyl

Tribological reactions of perfluoroalkyl polyether oils with stainless steel under ultrahigh vacuum conditions at room temperature

Science.gov (United States)

Mori, Shigeyuki; Morales, Wilfredo

1989-01-01

The reaction between three types of commercial perfluoroalkyl polyether (PFPE) oils and stainless steel 440C was investigated experimentally during sliding under ultrahigh vacuum conditions at room temperature. It is found that the tribological reaction of PFPE is mainly affected by the activity of the mechanically formed fresh surfaces of metals rather than the heat generated at the sliding contacts. The fluorides formed on the wear track act as a boundary layer, reducing the friction coefficient.

Investigation of sulfonated polysulfone membranes as electrolyte in a passive-mode direct methanol fuel cell mini-stack

Energy Technology Data Exchange (ETDEWEB)

Lufrano, F.; Baglio, V.; Staiti, P.; Stassi, A.; Arico, A.S.; Antonucci, V. [CNR - ITAE, Istituto di Tecnologie Avanzate per l' Energia ' ' Nicola Giordano' ' , Via Salita S. Lucia sopra Contesse n. 5 - 98126 S. Lucia - Messina (Italy)

2010-12-01

This paper reports on the development of polymer electrolyte membranes (PEMs) based on sulfonated polysulfone for application in a DMFC mini-stack operating at room temperature in passive mode. The sulfonated polysulfone (SPSf) with two degrees of sulfonation (57 and 66%) was synthesized by a well-known sulfonation process. SPSf membranes with different thicknesses were prepared and investigated. These membranes were characterized in terms of methanol/water uptake, proton conductivity, and fuel cell performance in a DMFC single cell and mini-stack operating at room temperature. The study addressed (a) control of the synthesis of sulfonated polysulfone, (b) optimization of the assembling procedure, (c) a short lifetime investigation and (d) a comparison of DMFC performance in active-mode operation vs. passive-mode operation. The best passive DMFC performance was 220 mW (average cell power density of about 19 mW cm{sup -2}), obtained with a thin SPSf membrane (70 {mu}m) at room temperature, whereas the performance of the same membrane-based DMFC in active mode was 38 mW cm{sup -2}. The conductivity of this membrane, SPSf (IEC = 1.34 mequiv. g{sup -1}) was 2.8 x 10{sup -2} S cm{sup -1}. A preliminary short-term test (200 min) showed good stability during chrono-amperometry measurements. (author)

An electrochemical study in aqueous solutions on the binding of dopamine to a sulfonated cyclodextrin host

International Nuclear Information System (INIS)

Hendy, Gillian M.; Breslin, Carmel B.

2012-01-01

Highlights: ► DA and Sβ-CD form an Inclusion complex. ► Electrochemical techniques demonstrated this inclusion complex. ► The association constant, K, was computed as 331.3. ► 1:1 stoichiometry for the inclusion complex was deduced from a Job's plot analysis. ► NMR studies confirmed the structural information on the inclusion complex. - Abstract: Clear evidence for the formation of a weak inclusion complex between dopamine (DA) and a sulfonated β-CD host in aqueous solution was obtained using a combination of electrochemical approaches. Using cyclic voltammetry, a distinct increase in the oxidation potential of DA and a reduction in the peak oxidation current were observed on adding an excess concentration of the sulfonated β-CD to the electrolyte solution. Equally, a clear increase in the half-wave oxidation potential of DA was observed in the presence of the sulfonated β-CD using rotating disc voltammetry. The association constant, K, was computed as 331.3 ± 5.8, indicating the formation of a weak inclusion complex, while a 1:1 stoichiometry for the inclusion complex was deduced from a Job's plot analysis. The rate constant for the oxidation of DA was found to decrease on formation of the inclusion complex. This was attributed to higher reorganization energy for the oxidation of the included DA. These changes in the electrochemistry of DA were not observed when an excess of the smaller sulfonated α-CD was added to the electrolyte, indicating that these variations are not connected with simple electrostatic interactions between the protonated DA and the anionic sulfonated groups. It is proposed that the aromatic ring of the DA molecule includes within the cyclodextrin cavity, while the protonated amine group remains outside the cavity, bound electrostatically with the anionic sulfonated groups.

Craniofacial reconstruction using patient-specific implants polyether ether ketone with computer-assisted planning.

Science.gov (United States)

Manrique, Oscar J; Lalezarzadeh, Frank; Dayan, Erez; Shin, Joseph; Buchbinder, Daniel; Smith, Mark

2015-05-01

Reconstruction of bony craniofacial defects requires precise understanding of the anatomic relationships. The ideal reconstructive technique should be fast as well as economical, with minimal donor-site morbidity, and provide a lasting and aesthetically pleasing result. There are some circumstances in which a patient's own tissue is not sufficient to reconstruct defects. The development of sophisticated software has facilitated the manufacturing of patient-specific implants (PSIs). The aim of this study was to analyze the utility of polyether ether ketone (PEEK) PSIs for craniofacial reconstruction. We performed a retrospective chart review from July 2009 to July 2013 in patients who underwent craniofacial reconstruction using PEEK-PSIs using a virtual process based on computer-aided design and computer-aided manufacturing. A total of 6 patients were identified. The mean age was 46 years (16-68 y). Operative indications included cancer (n = 4), congenital deformities (n = 1), and infection (n = 1). The mean surgical time was 3.7 hours and the mean hospital stay was 1.5 days. The mean surface area of the defect was 93.4 ± 43.26 cm(2), the mean implant cost was $8493 ± $837.95, and the mean time required to manufacture the implants was 2 weeks. No major or minor complications were seen during the 4-year follow-up. We found PEEK implants to be useful in the reconstruction of complex calvarial defects, demonstrating a low complication rate, good outcomes, and high patient satisfaction in this small series of patients. Polyether ether ketone implants show promising potential and warrant further study to better establish the role of this technology in cranial reconstruction.

Sulfonated phenolic material and its use in post primary oil recovery

Energy Technology Data Exchange (ETDEWEB)

Pardue, J. E.; Stapp, P. R.

1984-09-04

Sulfonated phenolic compounds as well as sulfomethylated phenolic compounds, surfactant systems containing such compound and the use of such surfactant systems in post primary oil recovery are disclosed.

Poly (ether imide sulfone) membranes from solutions in ionic liquids

KAUST Repository

Kim, Dooli; Nunes, Suzana Pereira

2017-01-01

A membrane manufacture method based on non-volatile solvents and a high performance polymer, poly (ether imide sulfone) (EXTEM™), is proposed, as greener alternative to currently industrial process. We dissolved EXTEM™ in pure ionic liquids: 1-ethyl

A facile and mild synthesis of trisubstituted allylic sulfones from Morita-Baylis-Hillman carbonates.

Science.gov (United States)

Jiang, Lin; Li, Yong-Gen; Zhou, Jiang-Feng; Chuan, Yong-Ming; Li, Hong-Li; Yuan, Ming-Long

2015-05-07

An efficient and catalyst-free synthesis of trisubstituted allylic sulfones through an allylic sulfonylation reaction of Morita-Baylis-Hillman (MBH) carbonates with sodium sulfinates has been developed. Under the optimized reaction conditions, a series of trisubstituted allylic sulfones were rapidly prepared in good to excellent yields (71%-99%) with good to high selectivity (Z/E from 79:21 to >99:1). Compared with known synthetic methods, the current protocol features mild reaction temperature, high efficiency and easily available reagents.

Synthesis and properties of hexafluoroisopropylidene-containing sulfonated poly(arylene thioether phosphine oxide)s for proton exchange membranes

Energy Technology Data Exchange (ETDEWEB)

Gui, Longyong; Zhang, Chunjie; Kang, Sen; Tan, Ning; Xiao, Guyu; Yan, Deyue [College of Chemistry and Chemical Engineering, The State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

2010-03-15

A series of novel sulfonated poly(arylene thioether phosphine oxide)s with hexafluoroisopropylidene moieties (sPTPOF) were prepared by polycondensation of sulfonated bis(4-fluorophenyl)phenyl phosphine oxide and bis(4-fluorophenyl)phenyl phosphine oxide with 4,4'-(hexafluoroisopropylidene) diphenthiol. The incorporation of hexafluoroisopropylidene moieties to the resulting polymers is effective to increase the hydrophobicity of non-sulfonated segments and to decrease the swelling while maintaining high proton conductivity. For instance, sPTPOF-100 showed a proton conductivity of 0.090 S/cm as well as a swelling of 5.3% at 80 C. In addition, the sPTPOF polymers exhibited excellent thermal properties and oxidative stability. AFM phase images illustrated that the sPTPOF membranes show a special nanophase-separated morphology, namely, the connectivity of ionic channels increased obviously but their width only slightly increased with increasing sulfonation degree. This special microstructure is favorable for promoting proton transport and restraining the swelling. The sPTPOF polymers are a promising material for proton exchange membranes. (author)

Implant Failure After Motec Wrist Joint Prosthesis Due to Failure of Ball and Socket-Type Articulation-Two Patients With Adverse Reaction to Metal Debris and Polyether Ether Ketone.

Science.gov (United States)

Karjalainen, Teemu; Pamilo, Konsta; Reito, Aleksi

2018-04-21

We describe 2 cases of articulation-related failures resulting in revision surgery after a Motec total wrist arthroplasty: one with an adverse reaction to metal debris and the other with an adverse reaction to polyether ether ketone. In the first patient, blood cobalt and chrome levels were elevated and magnetic resonance imaging showed clear signs of a pseudotumor. The other patient had an extensive release of polyether ether ketone particles into the surrounding synovia due to adverse wear conditions in the cup, leading to the formation of a fluid-filled cyst sac with a black lining and diffuse lymphocyte-dominated inflammation in the synovia. We recommend regular follow-up including x-rays, monitoring of cobalt and chrome ion levels, and a low threshold for cross-sectional imaging in patients who have undergone total wrist arthroplasty with a Motec joint prosthesis. Wear-related problems can also develop in implants in which polyether ether ketone is the bulk material. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Hybrid Nano composite Membranes for PEMFC Applications

International Nuclear Information System (INIS)

Niepceron, F.

2008-03-01

This work aims at validating a new concept of hybrid materials for the realization of proton exchange membranes, an essential constituent of PEM fuel cells. The originality of this nano-composite hybrid concept corresponds to a separation of the membrane's properties. We investigated the preparation of composite materials based on an inert, relatively low cost, polymer matrix (PVDF-HFP) providing the mechanical stability embedding inorganic fillers providing the necessary properties o f proton-conduction and water retention. The first step of this work consisted in the modification of fumed silica to obtain a proton-conducting filler. An ionic exchange capacity (CEI) equal to 3 meq/g was obtained by the original grafting of sodium poly(styrene-sulfonate) chains from the surface of particles. Nano-composite hybrid membranes PVDF-HFP/functionalized silica were accomplished by a film casting process. The coupling of the morphological and physicochemical analyses validated the percolation of the inorganic phase for 30 wt.% of particles. Beyond 40 % of loading, measured protonic conductivity is higher than the reference membrane Nafion 112. Finally, these membranes presented high performances, above 0.8 W/cm 2 , in single-cell fuel cell tests. A compromise is necessary according to the rate of loading between performances in fuel cell and mechanical properties of the membrane. 50 % appeared as best choice with, until 90 C, a remarkable thermal stability of the performances. (author)

Colorful Polyelectrolytes: An Atom Transfer Radical Polymerization Route to Fluorescent Polystyrene Sulfonate.

Science.gov (United States)

Huberty, Wayne; Tong, Xiaowei; Balamurugan, Sreelatha; Deville, Kyle; Russo, Paul S; Zhang, Donghui

2016-03-01

A labeled green fluorescent polystyrene sulfonate (LNaPSS) has been synthesized using atom transfer radical polymerization of a styrene sulfonate monomer with a fluorescent co-monomer, fluorescein thiocyanate-vinyl aniline. As a result this 100 % sulfonated polymer contains no hydrophobic patches along the chain backbone besides the fluorescent marker itself. The concentration of the fluorescent monomer was kept low to maintain the characteristic properties of the anionic polyelectrolyte, LNaPSS. ATRP conditions facilitated the production of polymers spanning a range of molecular weights from 35,000 to 175,000 in gram-scale batches with polydispersity indices of 1.01-1.24. Molecular weight increased with the monomer to initiator ratio. Gel permeation chromatography results show a unimodal distribution, and the polymer structure was also confirmed by (1)H NMR and FT-IR spectroscopy. Fluorescence spectroscopy confirmed covalent bonding of fluorescein isothiocyanate to the polymer, indicating that the polymer is suitable as a probe in fluorescence microscopy. To demonstrate this ability, the polymer was used to locate structural features in salt crystals formed during drying, as in the evaporation of sea mist. A second application to probe diffusion studies is also demonstrated.

Ion-Exchange-Induced Selective Etching for the Synthesis of Amino-Functionalized Hollow Mesoporous Silica for Elevated-High-Temperature Fuel Cells.

Science.gov (United States)

Zhang, Jin; Liu, Jian; Lu, Shanfu; Zhu, Haijin; Aili, David; De Marco, Roland; Xiang, Yan; Forsyth, Maria; Li, Qingfeng; Jiang, San Ping

2017-09-20

As differentiated from conventional synthetic processes, amino-functionalized hollow mesoporous silica (NH 2 -HMS) has been synthesized using a new and facile strategy of ion-exchange-induced selective etching of amino-functionalized mesoporous silica (NH 2 -meso-silica) by an alkaline solution. Nuclear magnetic resonance (NMR) spectroscopy and in situ time-resolved small-angle X-ray scattering (SAXS) reveal that ion-exchange-induced selective etching arises from the gradient distribution of OH - in the NH 2 -meso-silica nanospheres. Moreover, the ion-exchange-induced selective etching mechanism is verified through a successful synthesis of hollow mesoporous silica. After infiltration with phosphotungstic acid (PWA), PWA-NH 2 -HMS nanoparticles are dispersed in the poly(ether sulfone)-polyvinylpyrrolidone (PES-PVP) matrix, forming a hybrid PWA-NH 2 -HMS/PES-PVP nanocomposite membrane. The resultant nanocomposite membrane with an optimum loading of 10 wt % of PWA-NH 2 -HMS showed an enhanced proton conductivity of 0.175 S cm -1 and peak power density of 420 mW cm -2 at 180 °C under anhydrous conditions. Excellent durability of the hybrid composite membrane fuel cell has been demonstrated at 200 °C. The results of this study demonstrated the potential of the facile synthetic strategy in the fabrication of NH 2 -HMS with controlled mesoporous structure for application in nanocomposite membranes as a technology platform for elevated-temperature proton exchange membrane fuel cells.

Fe{sub 2}O{sub 3}-Poly-pyrrole hybrid nano-composite materials for super-capacitors

Energy Technology Data Exchange (ETDEWEB)

Mallouki, M.; Tran-Van, F.; Sarrazin, C.; Chevrot, C. [Cergy-Pontoise Univ., Lab. de Physicochimie des Polymeres et des Interfaces (LPPI), EA 2528 95 (France); Fauvarque, J.F. [CNAM, Lab. d' Electrochimie Industrielle, 75 - Paris (France); Simon, P. [Universite Paul Sabatier, CIRIMAT-LCMIE, UMR 5085, 31 - Toulouse (France); De, A. [Saha Institute of Nuclear Physics, Calcutta (India)

2004-07-01

Fe{sub 2}O{sub 3}-Poly-pyrrole hybrid nano-composite materials chemically synthesized from colloid particles of iron oxide in aqueous solution have been processed to realize electrode materials for super-capacitor applications. The performances have been evaluated by cyclic voltammetry and galvano-static techniques in a three-electrode cell. The capacitance of Fe{sub 2}O{sub 3}-PPy hybrid nano-composite doped with para-toluene-sulfonate reaches 47 mAh/g in PC/NEt{sub 4}BF{sub 4} with a good stability during cycling (loss of 3% after 1000 cycles). Transmission Electronic Microscopy indicates a porous nano-structure with spherical particles in a range of 400-500 nm which ensures a good accessibility of the electrolyte in the bulk of the electro-active hybrid material. Preliminary studies with room temperature ionic liquid show promising results since the specific capacitance reaches 427 F/g in 1- ethyl-3-methyl-imidazolium bis((tri-fluoro-methyl)sulfonyl)amide (EMITFSI). (authors)

Stabilized sulfonated aromatic polymers by in situ solvothermal cross-linking

Directory of Open Access Journals (Sweden)

Maria Luisa eDi Vona

2014-10-01

Full Text Available The cross-link reaction via sulfone bridges of sulfonated polyetheretherketone (SPEEK by thermal treatment at 180 °C in presence of dimethylsulfoxide (DMSO is discussed. The modifications of properties subsequent to the cross-linking are presented. The mechanical strength as well as the hydrolytic stability increased with the thermal treatment time, i.e., with the degree of cross-linking. The proton conductivity was determined as function of temperature, IEC, degree of cross-linking and hydration number. The memory effect, which is the membrane ability to remember the water uptake reached at high temperature also at lower temperature, is exploited in order to achieve high values of conductivity. Membranes swelled at 110 °C can reach a conductivity of 0.14 S/cm at 80°C with a hydration number ( of 73.

Radiation graft post-polymerization of sodium styrene sulfonate onto polyethylene

International Nuclear Information System (INIS)

Kitaeva, N.K.; Duflot, V.R.; Ilicheva, N.S.

2013-01-01

Post-irradiation grafting of sodium styrene sulfonate (SSS) in the presence of acrylic acid (AA) has been investigated on polyethylene (PE) pre-exposed to gamma radiation at room temperature in the air. Special attention was paid to the effect of low molecular weight salt additives on the kinetics of graft copolymerization of SSS and AA. The presence of SSS links in the grafted PE copolymers was detected by the methods of UV and FTIR spectroscopy. Based on the FTIR spectroscopy and element analysis data, a mechanism was proposed for graft copolymerization of SSS and AA onto PE. The mechanical properties of the graft copolymers were studied. It was established that PE copolymers grafted with sulfonic acid and carboxyl groups have higher strength characteristics (16.3 MPa) compared to the samples containing only carboxyl groups (11 MPa). (author)

Quinolinium 8-hydroxy-7-iodoquinoline-5-sulfonate 0.8-hydrate

Directory of Open Access Journals (Sweden)

Graham Smith

2012-12-01

Full Text Available In the crystal structure of the title hydrated quinolinium salt of ferron (8-hydroxy-7-iodoquinoline-5-sulfonic acid, C9H7N+·C9H5INO4S−·0.8H2O, the quinolinium cation is fully disordered over two sites (occupancy factors fixed at 0.63 and 0.37 lying essentially within a common plane and with the ferron anions forming π–π-associated stacks down the b axis [minimum ring centroid separation = 3.462 (6 Å]. The cations and anions are linked into chains extending along c through hydroxy O—H...O and quinolinium N—H...O hydrogen bonds to sulfonate O-atom acceptors which are also involved in water O—H...O hydrogen-bonding interactions along b, giving a two-dimensional network.

Salinomycin, a polyether ionophoric antibiotic, inhibits adipogenesis

International Nuclear Information System (INIS)

Szkudlarek-Mikho, Maria; Saunders, Rudel A.; Yap, Sook Fan; Ngeow, Yun Fong; Chin, Khew-Voon

2012-01-01

Highlights: ► Salinomycin inhibits preadipocyte differentiation into adipocytes. ► Salinomycin inhibits transcriptional regulation of adipogenesis. ► Pharmacological effects of salinomycin suggest toxicity in cancer therapy. -- Abstract: The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor γ. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy.

Cell Adhesion and Proliferation on Sulfonated and Non-Modified Chitosan Films.

Science.gov (United States)

Martínez-Campos, Enrique; Civantos, Ana; Redondo, Juan Alfonso; Guzmán, Rodrigo; Pérez-Perrino, Mónica; Gallardo, Alberto; Ramos, Viviana; Aranaz, Inmaculada

2017-05-01

Three types of chitosan-based films have been prepared and evaluated: a non-modified chitosan film bearing cationizable aliphatic amines and two films made of N-sulfopropyl chitosan derivatives bearing both aliphatic amines and negative sulfonate groups at different ratios. Cell adhesion and proliferation on chitosan films of C2C12 pre-myoblastic cells and B16 cells as tumoral model have been tested. A differential cell behavior has been observed on chitosan films due to their different surface modification. B16 cells have shown lower vinculin expression when cultured on sulfonated chitosan films. This study shows how the interaction among cells and material surface can be modulated by physicochemical characteristics of the biomaterial surface, altering tumoral cell adhesion and proliferation processes.

Oxidation reaction of polyether-based material and its suppression in lithium rechargeable battery using 4 V class cathode, LiNi1/3Mn1/3Co1/3O2.

Science.gov (United States)

Kobayashi, Takeshi; Kobayashi, Yo; Tabuchi, Masato; Shono, Kumi; Ohno, Yasutaka; Mita, Yuichi; Miyashiro, Hajime

2013-12-11

The all solid-state lithium battery with polyether-based solid polymer electrolyte (SPE) is regarded as one of next-generation lithium batteries, and has potential for sufficient safety because of the flammable-electrolyte-free system. It has been believed that polyether-based SPE is oxidized at the polymer/electrode interface with 4 V class cathodes. Therefore, it has been used for electric devices such as organic transistor, and lithium battery under 3 V. We estimated decomposition reaction of polyether used as SPE of all solid-state lithium battery. We first identified the decomposed parts of polyether-based SPE and the conservation of most main chain framework, considering the results of SPE analysis after long cycle operations. The oxidation reaction was found to occur slightly at the ether bond in the main chain with the branched side chain. Moreover, we resolved the issue by introducing a self-sacrificing buffer layer at the interface. The introduction of sodium carboxymethyl cellulose (CMC) to the 4 V class cathode surface led to the suppression of SPE decomposition at the interface as a result of the preformation of a buffer layer from CMC, which was confirmed by the irreversible exothermic reaction during the first charge, using electrochemical calorimetry. The attained 1500 cycle operation is 1 order of magnitude longer than those of previously reported polymer systems, and compatible with those of reported commercial liquid systems. The above results indicate to proceed to an intensive research toward the realization of 4 V class "safe" lithium polymer batteries without flammable liquid electrolyte.

Nucleophilic tetrafluoroethylation of carbonyl compounds with fluorinated sulfones

Czech Academy of Sciences Publication Activity Database

Václavík, Jiří; Chernykh, Yana; Jurásek, Bronislav; Beier, Petr

2015-01-01

Roč. 169, Jan (2015), s. 24-31 ISSN 0022-1139 R&D Projects: GA ČR GAP207/11/0421 Grant - others:GA MŠk(CZ) ED3.2.00/08.0144; GA MŠk(CZ) LM2010005 Institutional support: RVO:61388963 Keywords : fluorine * tetrafluoroethylation * sulfones * nucleophilic addition * carbonyl compounds Subject RIV: CC - Organic Chemistry Impact factor: 2.213, year: 2015

Ciguatoxins: Cyclic Polyether Modulators of Voltage-gated Iion Channel Function

Science.gov (United States)

Nicholson, Graham M.; Lewis, Richard J.

2006-01-01

Ciguatoxins are cyclic polyether toxins, derived from marine dinoflagellates, which are responsible for the symptoms of ciguatera poisoning. Ingestion of tropical and subtropical fin fish contaminated by ciguatoxins results in an illness characterised by neurological, cardiovascular and gastrointestinal disorders. The pharmacology of ciguatoxins is characterised by their ability to cause persistent activation of voltage-gated sodium channels, to increase neuronal excitability and neurotransmitter release, to impair synaptic vesicle recycling, and to cause cell swelling. It is these effects, in combination with an action to block voltage-gated potassium channels at high doses, which are believed to underlie the complex of symptoms associated with ciguatera. This review examines the sources, structures and pharmacology of ciguatoxins. In particular, attention is placed on their cellular modes of actions to modulate voltage-gated ion channels and other Na+-dependent mechanisms in numerous cell types and to current approaches for detection and treatment of ciguatera.

A Facile and Mild Synthesis of Trisubstituted Allylic Sulfones from Morita-Baylis-Hillman Carbonates

Directory of Open Access Journals (Sweden)

Lin Jiang

2015-05-01

Full Text Available An efficient and catalyst-free synthesis of trisubstituted allylic sulfones through an allylic sulfonylation reaction of Morita-Baylis-Hillman (MBH carbonates with sodium sulfinates has been developed. Under the optimized reaction conditions, a series of trisubstituted allylic sulfones were rapidly prepared in good to excellent yields (71%–99% with good to high selectivity (Z/E from 79:21 to >99:1. Compared with known synthetic methods, the current protocol features mild reaction temperature, high efficiency and easily available reagents.

Production of 5-hydroxymethylfurfural from starch-rich food waste catalyzed by sulfonated biochar.

Science.gov (United States)

Cao, Leichang; Yu, Iris K M; Chen, Season S; Tsang, Daniel C W; Wang, Lei; Xiong, Xinni; Zhang, Shicheng; Ok, Yong Sik; Kwon, Eilhann E; Song, Hocheol; Poon, Chi Sun

2018-03-01

Sulfonated biochar derived from forestry wood waste was employed for the catalytic conversion of starch-rich food waste (e.g., bread) into 5-hydroxymethylfurfural (HMF). Chemical and physical properties of catalyst were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area, and elemental analysis. The conversion of HMF was investigated via controlling the reaction parameters such as catalyst loading, temperature, and reaction time. Under the optimum reaction conditions the HMF yield of 30.4 Cmol% (i.e., 22 wt% of bread waste) was achieved in the mixture of dimethylsulfoxide (DMSO)/deionized-water (DIW) at 180 °C in 20 min. The effectiveness of sulfonated biochar catalyst was positively correlated to the density of strong/weak Brønsted acidity (SO 3 H, COOH, and OH groups) and inversely correlated to humins content on the surface. With regeneration process, sulfonated biochar catalyst displayed excellent recyclability for comparable HMF yield from bread waste over five cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.

THE SULFONATION STUDY OF REACTION MECHANISM ON PAPAVERINE ALKALOID BY GC-MS AND FT-IR

Directory of Open Access Journals (Sweden)

I Made Sudarma

2010-06-01

Full Text Available The aim of this research was to prove theoretical mechanism reaction on the sulfonation of papaverine alkaloid and the result could be used as a reference on the transformation of these alkaloid to the other derivatives. Theoriticaly sulfonation of papaverine (1 by HO-SO2Cl could produced papaverine sulfonyl chloride (1a. The formation of this product was analyzed by analytical thin layer chromatography GC-MS, and FT-IR. These analysis showed the formation of product (1a more favorable than the other. Tlc showed product (1a less polar than papaverine, and supported by GC-MS and infrared which showed molecular ion at m/z 412 due to the presence of -SO2Cl and vibration at 1153,4 dan 1265,2 Cm-1 due to absorption of sulfonyl group.   Keywords: reaction mechanism, sulfonation, papaverine alkaloid.

Evaluation of Sulfonate-Based Collectors with Different Hydrophobic Tails for Flotation of Fluorite

Directory of Open Access Journals (Sweden)

Renji Zheng

2018-02-01

Full Text Available This investigation aims to demonstrate the effects of hydrophobic tails on the affinity and relevant flotation response of sulfonate-based collectors for fluorite. For this purpose, a series of alkyl sulfonates with different hydrophobic tails, namely sodium decanesulfonate (C10, sodium dodecylsulfate (C12, sodium hexadecanesulfonate (C16, and sodium dodecylbenzenesulfonate (C12B were applied. The flotation tests showed that C12 and C12B had a better collecting performance than C10 and C16 at pH < 10, and the flotation recovery of fluorite was higher when adopting C12B as a collector compared with C12 with a strong base. The adsorption behaviors of collectors on the fluorite surface were studied through zeta potential, Fourier transform infrared (FTIR, and X-ray photoelectron spectroscopy (XPS analyses. It was found that the affinity of alkyl sulfonates for fluorite was enhanced with the increase of the alkyl chain length from C10 to C16. The existence of phenyl in the hydrophobic tail of sulfonates could improve its activity for fluorite by reducing its surface tension. The abnormal phenomenon C16 with a high affinity for fluorite had a low collecting performance for fluorite mainly due to its overlong alkyl chain, resulting in low solubility in pulp, which restrained its interaction with fluorite. We concluded that C12B was the most applicable collector for fluorite among these reagents due to its high activity, high solubility, and low cost, which was further substantiated by calculating their molecular frontier orbital energy.

NMR study of heteroligand lanthanide complexes. Structure and stoichiometry of chelates of cerium subgroup with 18-member polyethers

International Nuclear Information System (INIS)

Bajbalov, S.P.; Kriger, Yu.G.

1993-01-01

Different ligand complexes of lanthanides were studied by the method of 1 H NMR, the results being presented. The literature data on the study of complexes of the class in solution were generalized. Detection of lanthanide-induced splitting of group CH 2 diastereotopic proton signals of macrocyclic polyethers in the complexes is enough to identify kinetically stable complexes, having inclusive type structure. 16 refs., 2 figs., 2 tabs

Spectroscopic investigation of sulfonate phthalocyanine to probe enzyme reactions for heavy metals detection

Energy Technology Data Exchange (ETDEWEB)

Chaure, Shweta; Paul, Deepen; Vadagma, Pankaj [School of Engineering and Material Science, Queen Mary, University of London, London E1 4NS (United Kingdom); Ray, Asim K., E-mail: a.k.ray@qmul.ac.uk [School of Engineering and Material Science, Queen Mary, University of London, London E1 4NS (United Kingdom)

2010-01-15

Optical absorption and Raman spectra of the sulfonated copper phthalocyanine (CuTsPc) layer were exploited for detection of cadmium (Cd) contaminants in water. Acetylcholine esterase was immobilized by freely suspending them in calcium alginate microbeads and this gel was then spincoated on the drop cast sulfonated copper phthalocyanine film on a glass substrate to form a bilayer. The inhibition of catalytic reaction between acetylcholine chloride and enzyme due to Cd contaminants was monitored by recording changes in spectra of drop cast CuTsPc as an indicator. The detection limit of cadmium content in water was found to be 1 ppm.

Spectroscopic investigation of sulfonate phthalocyanine to probe enzyme reactions for heavy metals detection

International Nuclear Information System (INIS)

Chaure, Shweta; Paul, Deepen; Vadagma, Pankaj; Ray, Asim K.

2010-01-01

Optical absorption and Raman spectra of the sulfonated copper phthalocyanine (CuTsPc) layer were exploited for detection of cadmium (Cd) contaminants in water. Acetylcholine esterase was immobilized by freely suspending them in calcium alginate microbeads and this gel was then spincoated on the drop cast sulfonated copper phthalocyanine film on a glass substrate to form a bilayer. The inhibition of catalytic reaction between acetylcholine chloride and enzyme due to Cd contaminants was monitored by recording changes in spectra of drop cast CuTsPc as an indicator. The detection limit of cadmium content in water was found to be 1 ppm.

A facile synthesis of a novel optoelectric material: a nanocomposite of SWCNT/ZnO nanostructures embedded in sulfonated polyaniline

Directory of Open Access Journals (Sweden)

Rajesh K. Agrawalla

2014-07-01

Full Text Available Functionalized single-walled carbon nanotubes (f-SWCNTs hybridized with freshly prepared zinc oxide (ZnO nanocrystals have been found to be good luminescent material with tuned emission properties. A three-phase nanocomposite of sulfonated polyaniline embedded with such SWCNT/ZnO nanostructures has been prepared by a simple solution mixing chemical process and characterized by using high-resolution transmission electron microscopy, X-ray diffractometry, Raman spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The study of UV-visible absorption and photoluminescence spectroscopies reveal that the ternary polymer nanocomposite is a luminescent material with enhanced emission intensity. Also an increase in DC conductivity indicates that the nanocomposite is also a good conductive material, satisfying Mott’s variable range hopping model for a two-dimensional conduction. Such a three-phase nanocomposite may find extensive application in dye-sensitized solar cells, sensors, and supercapacitors.

ANALYSIS OF SULFONATES IN AQUEOUS SAMPLES BY ION-PAIR LC/ESI-MS/MS WITH IN-SOURCE CID FOR ADDUCT PEAK ELIMINATION

Energy Technology Data Exchange (ETDEWEB)

OUYANG,S.; VAIRAVAMURTHY,M.A.

1999-06-13

Determination of low-molecular-weight organic sulfonates (e.g. taurine and cysteic acid) in aqueous solutions is important in many applications of biological, environmental and pharmaceutical sciences. These compounds are difficult to be determined by commonly used reversed-phase liquid chromatographic separation combined with UV-Visible detection because of their high solubility and the lack chromophoric moieties. Here the authors report a method combining ion-pair liquid chromatography and electrospray ionization tandem mass spectrometry (IPLC/ESI-MS/MS)for determining sulfonates. The ability of low-molecular-weight sulfonates to form ion-pairs with quaternary ammonium cations in aqueous solutions allowed LC separation with a C{sub 18} column. Detection of the sulfonates was accomplished with ESI-MS that lends a universal mode of mass detection for polar, water soluble compounds. An in-source collision induced dissociation (CID) was applied to eliminate the adduct peaks in mass spectra. Characteristic marker ions showed in the second stage mass spectra lent a method for identifying sulfonates.

Effects of gamma radiation from 60Co on dilute aqueous solutions of Linear Alkyl Sulfonate Surfactants and other organic pollutants

International Nuclear Information System (INIS)

Rohrer, D.M.

1975-01-01

This study is the result of research findings and operational experiences gained by the author in over four years of work associated with the use of 60 Co for the treatment of waste-water. The effects of 60 Co are discussed with regard to radiochemical destruction of specific organic pollutant species. The study deals specifically with the effects of gamma radiation from a 30,000 Ci 60 Co source upon aqueous solutions of Linear Alkyl Sulfonate Surfactants. The new Linear Alkyl Sulfonate (LAS) Surfactants, the major surfactant produced in the United States of America since June 1965, was developed to replace the old Alkyl Benzene Sulfonate (ABS) Surfactants. The reason for the removal of Alkyl Benzene Sulfonate Surfactants was their extreme environmental stability and the associated appearance of foam in waste-water treatment plants and receiving streams. Although the Linear Alkyl Sulfonate Surfactants are considered 'bio-degradable', the time required for 'bio-degradation' is impractical within the present environmental guidelines. This led to research into alternate techniques of treatment for the destruction of Linear Alkyl Sulfonate Surfactants. Consideration is also given to similar effects of gamma radiation upon pesticides and to the practical aspects of the use of gamma radiation for the treatment of waste-water. Included are discussions of the general experimental procedures used, the sources and their calibration, and sampling techniques to ensure the accuracy of the data. (author)

A research on polyether glycol replaced APCP rocket propellant

Science.gov (United States)

Lou, Tianyou; Bao, Chun Jia; Wang, Yiyang

2017-08-01

Ammonium perchlorate composite propellant (APCP) is a modern solid rocket propellant used in rocket vehicles. It differs from many traditional solid rocket propellants by the nature of how it is processed. APCP is cast into shape, as opposed to powder pressing it with black powder. This provides manufacturing regularity and repeatability, which are necessary requirements for use in the aerospace industry. For traditional APCP, ingredients normally used are ammonium peroxide, aluminum, Hydroxyl-terminated polybutadiene(HTPB), curing agency and other additives, the greatest disadvantage is that the fuel is too expensive. According to the price we collected in our country, a single kilogram of this fuel will cost 200 Yuan, which is about 35 dollars, for a fan who may use tons of the fuel in a single year, it definitely is a great deal of money. For this reason, we invented a new kind of APCP fuel. Changing adhesive agency from cross-linked htpb to cross linked polyether glycol gives a similar specific thrust, density and mechanical property while costs a lower price.

Ciguatoxins: Cyclic Polyether Modulators of Voltage-gated Iion Channel Function

Directory of Open Access Journals (Sweden)

Richard J. Lewis

2006-04-01

Full Text Available Ciguatoxins are cyclic polyether toxins, derived from marine dinoflagellates, which are responsible for the symptoms of ciguatera poisoning. Ingestion of tropical and subtropical fin fish contaminated by ciguatoxins results in an illness characterised by neurological, cardiovascular and gastrointestinal disorders. The pharmacology of ciguatoxins is characterised by their ability to cause persistent activation of voltage-gated sodium channels, to increase neuronal excitability and neurotransmitter release, to impair synaptic vesicle recycling, and to cause cell swelling. It is these effects, in combination with an action to block voltage-gated potassium channels at high doses, which are believed to underlie the complex of symptoms associated with ciguatera. This review examines the sources, structures and pharmacology of ciguatoxins. In particular, attention is placed on their cellular modes of actions to modulate voltage-gated ion channels and other Na+-dependent mechanisms in numerous cell types and to current approaches for detection and treatment of ciguatera.

Uranium complexes with macrosyclic polyethers. Synthesis and structural chemical analysis

International Nuclear Information System (INIS)

Elbasyouny, A.

1983-01-01

This dissertation reports about studies on the chemical coordination behaviour of uranium of oxidation stages IV and VI with regard to twelve different macrocyclic ligands. For the preparation of the complexes, for every system a different method has been developed. The elementary analysis of the various complexes including the uranium had been done by X-ray fluorescence analysis, and the structural characterization proceeded via vibrational, uv-vis and emission spectroscopy as well as 1 H-NMR and 13 C-spin-lattice relaxation time studies. Conformational analysis of the polyethers used allowed the structural changes in the complexes to be observed. The structural analysis of the hydrous uranium VI crown ether complexes yielded information of characteristic features of these types of complexes. The first coordination sphere of the uranyl ion with covalently bonded anion remains unchanged. As to the water content, there is a certain range. Depending upon the solvent used, the complexes have two or four H 2 O molecules per formula unit. (orig./EF) [de

Synthesis of sulfonated porous carbon nanospheres solid acid by a facile chemical activation route

Energy Technology Data Exchange (ETDEWEB)

Chang, Binbin, E-mail: changbinbin806@163.com; Guo, Yanzhen; Yin, Hang; Zhang, Shouren; Yang, Baocheng, E-mail: baochengyang@yahoo.com

2015-01-15

Generally, porous carbon nanospheres materials are usually prepared via a template method, which is a multi-steps and high-cost strategy. Here, we reported a porous carbon nanosphere solid acid with high surface area and superior porosity, as well as uniform nanospheical morphology, which prepared by a facile chemical activation with ZnCl{sub 2} using resorcinol-formaldehyde (RF) resins spheres as precursor. The activation of RF resins spheres by ZnCl{sub 2} at 400 °C brought high surface area and large volume, and simultaneously retained numerous oxygen-containing and hydrogen-containing groups due to the relatively low processing temperature. The presence of these functional groups is favorable for the modification of –SO{sub 3}H groups by a followed sulfonation treating with sulphuric acid and organic sulfonic acid. The results of N{sub 2} adsorption–desorption and electron microscopy clearly showed the preservation of porous structure and nanospherical morphology. Infrared spectra certified the variation of surface functional groups after activation and the successful modification of –SO{sub 3}H groups after sulfonation. The acidities of catalysts were estimated by an indirect titration method and the modified amount of –SO{sub 3}H groups were examined by energy dispersive spectra. The results suggested sulfonated porous carbon nanospheres catalysts possessed high acidities and –SO{sub 3}H densities, which endowed their significantly catalytic activities for biodiesel production. Furthermore, their excellent stability and recycling property were also demonstrated by five consecutive cycles. - Graphical abstract: Sulfonated porous carbon nanospheres with high surface area and superior catalytic performance were prepared by a facile chemical activation route. - Highlights: • Porous carbon spheres solid acid prepared by a facile chemical activation. • It owns high surface area, superior porosity and uniform spherical morphology. • It possesses

Study of Microhardness and Electrical Properties of Proton Irradiated Polyether sulfone

International Nuclear Information System (INIS)

Quresh, A.

2006-01-01

Polyethersulfone (PES) films were irradiated with 3 MeV proton beams in the fluence range 10 1 3-10 1 5 ions/cm 2 . The irradiated samples were characterized by a Vickers' microhardness tester at a load of 100-1000 mN, and electrical properties in the frequency range 100 Hz to 1MHz by an LCR meter. It is observed that microhardness increases as fluence increases up to the fluence of 10 1 4 ions/cm 2 and decreases on further increase of the fluence. This may be attributed to the fact that a cross linking phenomenon dominates up to the fluence of 10 1 4 ions/cm 2 . There is an exponential increase in conductivity and the effect of irradiation is significant at higher fluences. The dielectric constant/loss was found to change significantly due to irradiation. It has been found that dielectric response in both pristine and irradiated samples obey universal law is given by ε α f n -1.These results were corroborated with structural changes observed in FTIR spectra of pristine and irradiated samples

Copper(I)-catalyzed olefination of N-sulfonylhydrazones with sulfones.

Science.gov (United States)

Xu, Shuai; Gao, Yunpeng; Chen, Ri; Wang, Kang; Zhang, Yan; Wang, Jianbo

2016-03-25

The Cu(I)-catalyzed olefination of N-sulfonylhydrazones with sulfones via metal carbene intermediates is reported. This reaction uses readily available starting materials and is operationally simple, thus representing a practical method for the construction of carbon-carbon double bonds. Mechanistically, Cu(I) carbene formation and subsequent carbene migratory insertion are proposed as the key steps.

Multi-block sulfonated poly(phenylene) copolymer proton exchange membranes

Science.gov (United States)

Fujimoto, Cy H [Albuquerque, NM; Hibbs, Michael [Albuquerque, NM; Ambrosini, Andrea [Albuquerque, NM

2012-02-07

Improved multi-block sulfonated poly(phenylene) copolymer compositions, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cells, in electrode casting solutions and electrodes. The multi-block architecture has defined, controllable hydrophobic and hydrophilic segments. These improved membranes have better ion transport (proton conductivity) and water swelling properties.

Colitis induced by sodium polystyrene sulfonate in sorbitol: A report of six cases.

Science.gov (United States)

Jacob, Sheba S K; Parameswaran, Ashok; Parameswaran, Sarojini Ashok; Dhus, Ubal

2016-03-01

Drug-related injury has been noted in virtually all organ systems, and recognition of the patterns of injury associated with medication enables modification of treatment and reduces the morbidity associated with the side effects of drugs. With the large number of new drugs being developed, documentation of the morphology of the changes seen as an adverse effect becomes important to characterize the pattern of injury. The pathologist is often the first to identify these abnormalities and correlate them with a particular drug. Kayexalate or sodium polystyrene sulfonate (SPS), a linear polymer derived from polystyrene containing sulfonic acid and sulfonate functional groups is used to treat hyperkalemia. It is usually administered with an osmotic laxative sorbitol orally or as retention enema. This combination has been implicated in causing damage to different parts of the gastrointestinal (GI) tract especially the colon and causes an established pattern of injury, recognizable by the presence of characteristic crystals, is presented to create a greater awareness of the Kayexalate colitis. This entity should be included in the differential diagnosis of lower GI mucosal injury in a setting of uremia and hyperkalemia.

Membranes for hydrogen and fuel cell technology; Membranas para celula combustivel e separacao de hidrogenio

Energy Technology Data Exchange (ETDEWEB)

Nunes, Suzana Pereira [GKSS-Forschungszentrum, Geesthacht (Germany)]. E-mail: nunes@gkss.de

2005-07-01

Membranes for fuel cell were prepared using as polymer matrix sulfonated polyether ketones. New sulfonated copolymers (poly oxazoles, poly imides and poly ketones) were synthesized. Nano composites using zirconium oxide and phosphates, as well as modified silicates were obtained aiming the application on direct methanol fuel cell (DMFC). The performances of membranes containing fillers with different aspects (spherical, layers, tubular, networks) and surface modification (hydroxy, imidazole, acid oligomers) were compared. The effect of surface modification was much more pronounced than that of the aspect. A good balance of proton conductivity and methanol permeability was obtained with silicates modified with imidazole groups. Good performance in DMFC were obtained with membranes containing zirconium phosphate. Acid oligomers also led to particularly high conductivity values above 100 deg C. Polyimide membranes with H{sub 2}/CH{sub 4} larger than 100 were obtained. (author )

Structure and properties of compositions based on petroleum sulfonic acids

Energy Technology Data Exchange (ETDEWEB)

Tutorskii, I.A.; Sultanova, A.S.; Belkina, E.V.; Fomin, A.G. [Lomonosov Academy of Fine Chemical Technology, Moscow (Russian Federation)

1995-03-01

Colloidal characteristics of compositions based on petroleum sulfonic acids were studied. Neutralized heavy oil residue exhibits surface-active properties and contains an ultradisperse filler. Analysis of the compositions by size-exclusion-chromatography shows deep structural changes in the heavy acid residue upon neutralization with calcium carbonate.

Validation of a liquid chromatography-electrospray ionization tandem mass spectrometric method to determine six polyether ionophores in raw, UHT, pasteurized and powdered milk.

Science.gov (United States)

Pereira, Mararlene Ulberg; Spisso, Bernardete Ferraz; Jacob, Silvana do Couto; Monteiro, Mychelle Alves; Ferreira, Rosana Gomes; Carlos, Betânia de Souza; da Nóbrega, Armi Wanderley

2016-04-01

This study aimed to validate a method developed for the determination of six antibiotics from the polyether ionophore class (lasalocid, maduramicin, monensin, narasin, salinomycin and semduramicin) at residue levels in raw, UHT, pasteurized and powdered milk using QuEChERS extraction and high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The validation was conducted under an in-house laboratory protocol that is primarily based on 2002/657/EC Decision, but takes in account the variability of matrix sources. Overall recoveries between 93% and 113% with relative standard deviations up to 16% were obtained under intermediate precision conditions. CCα calculated values did not exceed 20% the Maximum Residue Limit for monensin and 25% the Maximum Levels for all other substances. The method showed to be simple, fast and suitable for verifying the compliance of raw and processed milk samples regarding the limits recommended by Codex Alimentarius and those adopted in European Community for polyether ionophores. Copyright © 2015 Elsevier Ltd. All rights reserved.

Study on properties of cation-exchange membranes containing sulfonate groups

International Nuclear Information System (INIS)

Zu Jianhua; Wu Minghong; Qiu Shilong; Yao Side; Ye Yin

2004-01-01

Strong acid cation-exchange membranes were obtained by irradiation grafting of acrylic acid (AA) and sodium styrene sulfonate (SSS) onto high-density polyethylene (HDPE). Thermal and chemical stability of the cation-exchange membranes was investigated. The effectiveness of sulfonate-containing films was conformed in inducing high resistance to oxidative degradation. Thermal stability of the grafted HDPE was weaker than HDPE as detected by TGA analyzing technique. Char residue by TGA of the grafted HDPE is greater than that of HDPE. It shows that the branch chains including -SO 3 Na and -COOH was grafted onto the backbone of HDPE, and thus give a catalytic impetus to the charing. Crystallinity of the grafted membranes decreased with increasing grafting yield of the membrane samples. It is supposed that the decreased crystallinity is due to collective effects of the inherent crystallinity dilution by the amorphous grafted chains and disruption of spherulitic crystallites of the HDPE component

Mortar modified with sulfonated polystyrene produced from waste plastic cups

Directory of Open Access Journals (Sweden)

L. A. C. MOTTA

Full Text Available Abstract In this work, we studied the addition of sulfonated polystyrene produced from waste plastic cups as an admixture for mortars. Mortars were analyzed with polystyrene content of 0.0; 0.2; 0.6; 1.0 and 1.4% in relation to the cement mass. The influence of polystyrene on the mortars' properties was evaluated by the consistency index, water retention, water absorption, porosity, elasticity modulus, compressive strength, flexural strength, bond tensile strength and microscopy. The increase in the sulfonated polystyrene content decreased the elasticity modulus of the mortar and, despite higher porosity, there was a reduction of water absorption by capillarity. In relation to mortar without admixture, the modified mortar showed an increase in water retention and consistency index, and a large increase in flexural strength and bond tensile strength. The significant increase of bond tensile strength (214% with admixture 1% highlights the potential of the produced material as an adhesive mortar.

Salinomycin, a polyether ionophoric antibiotic, inhibits adipogenesis

Energy Technology Data Exchange (ETDEWEB)

Szkudlarek-Mikho, Maria; Saunders, Rudel A. [Department of Medicine, Biochemistry and Cancer Biology, Center for Diabetes and Endocrine Research, College of Medicine, University of Toledo, Toledo, OH 43614 (United States); Yap, Sook Fan [Faculty of Medicine and Health Sciences, Department of Pre-Clinical Sciences, University of Tunku Abdul Rahman (Malaysia); Ngeow, Yun Fong [Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603 (Malaysia); Chin, Khew-Voon, E-mail: khew-voon.chin@utoledo.edu [Department of Medicine, Biochemistry and Cancer Biology, Center for Diabetes and Endocrine Research, College of Medicine, University of Toledo, Toledo, OH 43614 (United States)

2012-11-30

Highlights: Black-Right-Pointing-Pointer Salinomycin inhibits preadipocyte differentiation into adipocytes. Black-Right-Pointing-Pointer Salinomycin inhibits transcriptional regulation of adipogenesis. Black-Right-Pointing-Pointer Pharmacological effects of salinomycin suggest toxicity in cancer therapy. -- Abstract: The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor {gamma}. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy.

In vitro hemocompatibility of sulfonated polypropylene non-woven fabric prepared via a facile γ-ray pre-irradiation grafting method

Energy Technology Data Exchange (ETDEWEB)

Li, Rong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Wu, Guozhong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031 (China); Ye, Yin, E-mail: yeyin@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

2015-11-30

Graphical abstract: - Highlights: • Sulfonated PP{sub NWF} was successfully fabricated via γ-ray pre-irradiation-induced graft polymerization of SSS method with the aid of AAm. • Compared with the pristine PP{sub NWF}, the sulfonated PP{sub NWF} material presented outstanding hydrophilicity. • The sulfonated PP{sub NWF} exhibited good hemocompatibility. - Abstract: Sulfonated polypropylene non-woven fabric (PP{sub NWF}) was successfully prepared via γ-ray pre-irradiation-induced graft polymerization of sodium styrenesulfonate (SSS) and acrylamide (AAm). The effect of pre-irradiation dose, reaction temperature, reaction time and concentration of binary monomer on the degree of grafting (DG) was studied. The chemical structure of the original and modified PP{sub NWF} materials were investigated by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) to confirm the successful introduction of sulfonated (−SO{sub 3}{sup −}) group. The wettability was examined via measurement of de-ionized water adsorption percentage, which demonstrated that the hydrophilicity of PP{sub NWF} was greatly enhanced after graft modification. A little amount of bovine serum albumin (BSA) adsorption and nearly no platelet adhesion on the surface of modified PP{sub NWF} and low hemolytic ratio of the modified PP{sub NWF} revealed that the sulfonated PP{sub NWF} exhibited good hemocompatibility. Besides, blood clotting time measurement indicated that the anticoagulant property of PP{sub NWF} was effectively enhanced via SSS modification. Consequently, the hydrophilicity, in vitro hemocompatibility and anticoagulant effect of PP{sub NWF} were significantly improved by γ-ray pre-irradiation-induced graft polymerization of SSS.

Clinical characteristics of an allergic reaction to a polyether dental impression material.

Science.gov (United States)

Rafael, Caroline Freitas; Liebermann, Anja

2017-04-01

Allergic and hypersensitivity reactions to dental impression materials may occur throughout dental treatment, with diverse manifestations from slight redness to severe pain and a burning mouth with total stomatitis. Patients are often unaware of these allergic reactions, which makes early identification of the cause almost impossible. In addition, symptoms usually begin after 24 hours and mostly in patients with a preexisting history of allergic responses. This report describes a patient with a suspected allergic reaction to a polyether dental impression material during prosthetic rehabilitation associated with a mandibular telescopic denture. Although instances of such occurrence are rare, clinicians need to be aware of these symptoms and select materials carefully for patients with a history of allergy. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Estimated pKa values for the environmentally relevant C1 through C8 perfluorinated sulfonic acid isomers.

Science.gov (United States)

Rayne, Sierra; Forest, Kaya

2016-10-14

In order to estimate isomer-specific acidity constants (pKa) for the perfluorinated sulfonic acid (PFSA) environmental contaminants, the parameterization method 6 (PM6) pKa prediction method was extensively validated against a wide range of carbon oxyacids and related sulfonic/sulfinic acids. Excellent pKa prediction performance was observed for the carbon oxyacids using the PM6 method, but this approach was found to have a severe positive bias for sulfonic/sulfinic acids. To overcome this obstacle, a correlation was developed between non-adjusted PM6 pKa values and the corresponding experimentally obtained/estimated acidity constants for a range of representative alkyl, aryl and halogen-substituted sulfonic acids. Application of this correction to the PM6 values allows for extension of this computational method to a new acid functional group. When used to estimate isomer-specific pKa values for the C1 through C8 PFSAs, the modified PM6 approach suggests an adjusted pKa range from -5.3 to -9.0, indicating that all members of this class of well-known environmental contaminants will be effectively completely dissociated in aquatic systems.

The influence of chain rigidity and the degree of sulfonation on the morphology of block copolymers as nano reactor

Science.gov (United States)

Hong, K.; Zhang, X.

2005-03-01

Polyelectrolyte block copolymer was used to form an ordered domain of ionic block as a ``nanoreactor'' due to its ability to bind oppositely charged metal ion, Zn^2+, Fe^2+ etc. The purpose of our research is to investigate the controllability of the size and morphology of domains (inorganic nano particles) by changing backbone stiffness, the charge density and the volume fraction of ionic block. Poly(styrene sulfonate) (PSS), which backbone is flexible, and poly(cyclohexadiene sulfonate) (PCHDS), which backbone is ``semiflexible'', were used as ionic blocks. We synthesized PtBS-PSS and PS-PCHDS with various degree of sulfonation and the volume fraction. Zinc oxide (ZnO) nano particles successfully formed in the ionic domain of microphase separated block copolymers. We used SANS to characterize the morphology of block copolymers and TEM for block copolymer containing ZnO nano particles. Our experimental results show that the chemistry of ``sulfonation'' of block copolymers can be successfully used to synthesize nano composite materials.

Epoxy-crosslinked sulfonated poly (phenylene) copolymer proton exchange membranes

Science.gov (United States)

Hibbs, Michael; Fujimoto, Cy H.; Norman, Kirsten; Hickner, Michael A.

2010-10-19

An epoxy-crosslinked sulfonated poly(phenylene) copolymer composition used as proton exchange membranes, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cell, in electrode casting solutions and electrodes, and in sulfur dioxide electrolyzers. These improved membranes are tougher, have higher temperature capability, and lower SO.sub.2 crossover rates.

Analysis of electron-irradiated poly-ether ether ketone by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Oyabu, Matashige; Kobayashi, Yoshinori; Seguchi, Tadao; Sasuga, Tsuneo; Kudoh, Hisaaki.

1995-01-01

Organic polymers used in atomic power plants or space are damaged by ionizing irradiation. Radicals produced by irradiation cause oxidation, chain scission and crosslinking, all of which lead to degradation of the material. In this paper, the surface of electron-irradiated poly-ether ether ketone (PEEK) was studied by X-ray photoelectron spectroscopy (XPS). The irradiation in air was found to oxidize the PEEK surface producing carboxyl groups, the content of which dependant on the dose. Carboxyl groups were not produced in helium gas. Quantitative spectral analysis indicated that the aromatic structure might be decomposed. Some comparison was made between the semicrystalline and amorphous samples. The oxygen content resulting from irradiation, of semicrystalline PEEK increased more than that of amorphous PEEK. (author)

Major sulfonate transporter Soa1 in Saccharomyces cerevisiae and considerable substrate diversity in its fungal family

DEFF Research Database (Denmark)

Holt, Sylvester; Kankipati, Harish; De Graeve, Stijn

2017-01-01

Sulfate is a well-established sulfur source for fungi; however, in soils sulfonates and sulfate esters, especially choline sulfate, are often much more prominent. Here we show that Saccharomyces cerevisiae YIL166C(SOA1) encodes an inorganic sulfur (sulfate, sulfite and thiosulfate) transporter...... that also catalyses sulfonate and choline sulfate uptake. Phylogenetic analysis of fungal SOA1 orthologues and expression of 20 members in the sul1 Delta sul2 Delta soa1 Delta strain, which is deficient in inorganic and organic sulfur compound uptake, reveals that these transporters have diverse substrate...... preferences for sulfur compounds. We further show that SOA2, a S. cerevisiae SOA1 paralogue found in S. uvarum, S. eubayanus and S. arboricola is likely to be an evolutionary remnant of the uncharacterized open reading frames YOL163W and YOL162W. Our work highlights the importance of sulfonates and choline...

Synthesis of fully and partially sulfonated polyanilines derived from ortanilic acid: An electrochemical and electromicrogravimetric study

International Nuclear Information System (INIS)

Cano Marquez, Abraham Guadalupe; Torres Rodriguez, Luz Maria; Montes Rojas, Antonio

2007-01-01

The electrochemical polymerization of 2-aminobenzene sulfonic acid, also called ortanilic acid (o-ASA), on a gold electrode precoated with polyaniline (PANI), has been carried out. We proved that the electropolymerization of o-ASA is enhanced on PANI electrodes, resulting in thicker films obtained in aqueous media at room temperature. The electrosynthesized film (P(o-ASA)) was characterized by cyclic voltammetry, FTIR and nuclear magnetic resonance. The compensation of P(o-ASA) charge was evaluated using electrochemical quartz crystal microbalance combined with cyclic voltammetry, which showed that the electroneutralization process mainly involves cations. Additionally, copolymers of aniline and o-ASA were electrosynthesized, using a metallic electrode modified with PANI also as a working electrode. The degree of sulfanation of copolymers has been modulated with the proportions of monomers in the electrosynthesis solution. The studies reveal a more important participation of cations in fully sulfonated polyaniline than in partially sulfonated polyaniline

Extended x-ray absorption fine structure: Studies of zinc-neutralized sulfonated polystyrene ionomers

International Nuclear Information System (INIS)

Ding, Y.S.; Yarusso, D.J.; Pan, H.K.D.; Cooper, S.L.

1984-01-01

Extended x-ray absorption fine structure (EXAFS) measurements were performed on a series of zinc-neutralized sulfonated polystyrene ionomers and the local structure around the zinc atom was determined. An interference effect in the EXAFS signal between sulfur and oxygen atoms was found to be significant in these materials. A model for the local structure in the zinc-neutralized sulfonated polystyrene ionomers is proposed which suggests a highly ordered tetrahedral coordination of oxygen around the zinc atoms at a distance of 1.97 +- 0.02 A. In addition there are four sulfur atoms and four oxygen atoms at a distance of 3.15 +- 0.05 A. No zinc-zinc coordination within 5 A was detected in this study

Novel non-covalent sulfonated multiwalled carbon nanotube from p-toluenesulfonic acid/glucose doped polypyrrole for electrochemical capacitors

Energy Technology Data Exchange (ETDEWEB)

Fu, Q.B.; Gao, B.; Hao, L.; Lu, X.J.; Yang, S.D.; Zhang, X.G. [Nanjing Univ. of Aeronautics and Astronautics (China). College of Material Science and Engineering

2010-07-01

Polypyrrole (PPy) is considered as one of the most promising electrode materials for electrochemical capacitors due to its environmental stability and fast doping and dedoping capacity. Carbon nanotube (CNT) and PPy hybrids can work synergistically to achieve the advantages of an electric double layer capacitor and faradaic pseudocapacitor. Sulfonation can be used to increase the dispersion of CNTs. In this study, multiwalled CNTs (MWCNTs) were modified with a high -SOH{sub 3}H loading carbonaceous material. Pyrolle monomers were absorbed on the surface of the MWCNT-SO{sub 3}H composite through strong electron and hydrogen bonding interactions between the -SO{sub 3}H group and the amino group of pyrrole. The pyrrole was then in-situ polymerized on the surface of the MWCNTs with the addition of an initiator. The study showed that the specific capacitance loss of the MWCNTs-SO{sub 3}H/PPy was only 3 per cent after 1000 cycles. Results of the study suggested that the composite is a promising electrode material for electrochemical capacitors. 2 refs., 2 figs.

Moving beyond mass-based parameters for conductivity analysis of sulfonated polymers

Energy Technology Data Exchange (ETDEWEB)

Kim, Yu Seung [Los Alamos National Laboratory; Pivovar, Bryan [NREL

2009-01-01

Proton conductivity of polymer electrolytes is critical for fuel cells and has therefore been studied in significant detail. The conductivity of sulfonated polymers has been linked to material characteristics in order to elucidate trends. Mass based measurements based on water uptake and ion exchange capacity are two of the most common material characteristics used to make comparisons between polymer electrolytes, but have significant limitations when correlated to proton conductivity. These limitations arise in part because different polymers can have significantly different densities and conduction happens over length scales more appropriately represented by volume measurements rather than mass. Herein, we establish and review volume related parameters that can be used to compare proton conductivity of different polymer electrolytes. Morphological effects on proton conductivity are also considered. Finally, the impact of these phenomena on designing next generation sulfonated polymers for polymer electrolyte membrane fuel cells is discussed.

Polyaniline nanotubes and their dendrites doped with different naphthalene sulfonic acids

International Nuclear Information System (INIS)

Zhang Zhiming; Wei Zhixiang; Zhang Lijuan; Wan Meixiang

2005-01-01

Polyaniline (PANI) nanotubes (130-250 nm in average diameter) doped with α-naphthalene sulfonic acid (α-NSA), β-naphthalene sulfonic acid (β-NSA) and 1,5-naphthalene disulfonic acid were synthesized via a self-assembly process. It was found that the formation yield, morphology (hollow or solid), size, crystalline and electrical properties of the nanostructures are affected by the position and number of -SO 3 H groups attached to the naphthalene ring of NSA as well as the synthesis conditions. Moreover, these nanotubes aggregate to form a dendritic morphology when the polymerization is performed at a static state. The micelles composed of dopant or dopant/anilinium cations might act in a template-like fashion in forming self-assembled PANI nanotubes, which was further confirmed by X-ray diffraction measurements, while the aggregated morphology of the nanotubes might result from polymer chain interactions including π-π interactions, hydrogen and ionic bonds

Dismantlable Thermosetting Adhesives Composed of a Cross-Linkable Poly(olefin sulfone) with a Photobase Generator.

Science.gov (United States)

Sasaki, Takeo; Hashimoto, Shouta; Nogami, Nana; Sugiyama, Yuichi; Mori, Madoka; Naka, Yumiko; Le, Khoa V

2016-03-02

A novel photodetachable adhesive was prepared using a photodepolymerizable cross-linked poly(olefin sulfone). A mixture of a cross-linkable poly(olefin sulfone), a cross-linking reagent, and a photobase generator functioned as a thermosetting adhesive and exhibited high adhesive strength on quartz plates comparable to that obtained for commercially available epoxy adhesives. The cured resin was stable in the absence of UV light irradiation but completely lost its adhesive strength upon exposure of glued quartz plates to UV light in conjunction with heating to 100 °C.

Development and characterization of acid-doped polybenzimidazole/sulfonated polysulfone blend polymer electrolytes for fuel cells

DEFF Research Database (Denmark)

Hasiotis, C.; Li, Qingfeng; Deimede, V.

2001-01-01

Polymeric membranes from blends of sulfonated polysulfones (SPSF) and polybenzimidazole (PBI) doped with phosphoric acid were developed as potential high-temperature polymer electrolytes for fuel cells and other electrochemical applications. The water uptake and acid doping of these polymeric...... membranes were investigated. Ionic conductivity of the membranes was measured in relation to temperature, acid doping level, sulfonation degree of SPSF, relative humidity, and blend composition. The conductivity of SPSF was of the order of 10/sup -3/ S cm/sup -1/. In the case of blends of PBI and SPSF...

Fast atom bombardment mass spectrometry of condensed tannin sulfonate derivatives

Science.gov (United States)

J.J. Karchesy; L.Y. Foo; Richard W. Hemingway; E. Barofsky; D.F. Barofsky

1989-01-01

Condensed tannin sulfonate derivatives were studied by fast atom bombardment mass spectrometry (FAB-MS) to assess the feasibility of using this technique for determining molecular weight and structural information about these compounds. Both positive- and negative-ion spectra provided useful data with regard to molecular weight, cation species present, and presence of...

Chondrogenesis on sulfonate-coated hydrogels is regulated by their mechanical properties.

Science.gov (United States)

Kwon, Hyuck Joon; Yasuda, Kazunori

2013-01-01

Many studies have demonstrated that sulfur-containing acidic groups induce chondrogenesis in vitro and in vivo. Recently, it is increasingly clear that mechanical properties of cell substrates largely influence cell differentiation. Thus, the present study investigated how mechanical properties of sulfonate-coated hydrogels influences chondrogenesis of mesenchymal stem cells (MSCs). Sulfonate-coated polyacrylamide gels (S-PAAm gels) which have the elastic modulus, E, of about 1, 15 and 150 kPa, were used in this study. MSCs cultured on the high stiffness S-PAAm gels (E=∼150 kPa) spread out with strong expression of stress fibers, while MSCs cultured on the low stiffness S-PAAm gels (E=∼1 kPa) had round shapes with less stress fibers but more cortical actins. Importantly, even in the absence of differentiation supplements, the lower stiffness S-PAAm gels led to the higher mRNA levels of chondrogenic markers such as Col2a1, Agc and Sox9 and the lower mRNA levels of an undifferentiation marker Sca1, indicating that the mechanical properties of S-PAAm gels strongly influence chondrogenesis. Blebbistatin which blocks myosin II-mediated mechanical sensing suppressed chondrogenesis induced by the low stiffness S-PAAm gels. The present study demonstrates that the soft S-PAAm gels effectively drive MSC chondrogenesis even in the absence of soluble differentiation factors and thus suggests that sulfonate-containing hydrogels with low stiffness could be a powerful tool for cartilage regeneration. Copyright © 2012 Elsevier Ltd. All rights reserved.

Study of water role during the complexing of uranyl aquanitrate compounds with cyclic polyethers

International Nuclear Information System (INIS)

Belomestnykh, V.I.; Sveshnikova, L.B.; Shabel'nik, K.S.

1990-01-01

By the method of vibrational spectroscopy and thermogravimetry the determining role of water molecules during complexing of uranyl aquonitrate compounds with macrocyclic polyethers is confirmed. It is ascertained that in the synthesized complexes of the composition UO 2 (NO 3 ) 2 (H 2 O) 2 ·mH 2 O·nL (m=0,1,2; L-18-crown-6, 15-crown-5, dibenzo-18-crown-6; n=1,2) molecules of macrocyclic ligand are joined at the expense of strong hydrogen bonds with participation of protons of crystallographically nonequivalent water molecules. In the compounds hydrogen bonds of water-water and water-nitrato group type are also realized. Energies of the above-mentioned bonds are calculated

Proton-transfer compounds of 8-hydroxy-7-iodoquinoline-5-sulfonic acid (ferron) with 4-chloroaniline and 4-bromoaniline.

Science.gov (United States)

Smith, Graham; Wermuth, Urs D; Healy, Peter C

2007-07-01

The crystal structures of the proton-transfer compounds of ferron (8-hydroxy-7-iodoquinoline-5-sulfonic acid) with 4-chloroaniline and 4-bromoaniline, namely 4-chloroanilinium 8-hydroxy-7-iodoquinoline-5-sulfonate monohydrate, C(6)H(7)ClN(+) x C(9)H(5)INO(4)S(-) x H(2)O, and 4-bromoanilinium 8-hydroxy-7-iodoquinoline-5-sulfonate monohydrate, C(6)H(7)BrN(+) x C(9)H(5)INO(4)S(-) x H(2)O, have been determined. The compounds are isomorphous and comprise sheets of hydrogen-bonded cations, anions and water molecules which are extended into a three-dimensional framework structure through centrosymmetric R(2)(2)(10) O-H...N hydrogen-bonded ferron dimer interactions.

Improving the Efficacy of Conventional Therapy by Adding Andrographolide Sulfonate in the Treatment of Severe Hand, Foot, and Mouth Disease: A Randomized Controlled Trial

Directory of Open Access Journals (Sweden)

Xiuhui Li

2013-01-01

Full Text Available Background. Herb-derived compound andrographolide sulfonate (called Xiyanping injection recommended control measure for severe hand, foot, and mouth disease (HFMD by the Ministry of Health (China during the 2010 epidemic. However, there is a lack of good quality evidence directly comparing the efficacy of Andrographolide Sulfonate combination therapy with conventional therapy. Methods. 230 patients were randomly assigned to 7–10 days of Andrographolide Sulfonate 5–10 mg/Kg/day and conventional therapy, or conventional therapy alone. Results. The major complications occurred less often after Andrographolide Sulfonate (2.6% versus 12.1%; risk difference [RD], 0.94; 95% CI, 0.28–1.61; P=0.006. Median fever clearance times were 96 hours (CI, 80 to 126 for conventional therapy recipients and 48 hours (CI, 36 to 54 for Andrographolide Sulfonate combination-treated patients (χ2=16.57, P<0.001. The two groups did not differ in terms of HFMD-cause mortality (P=1.00 and duration of hospitalization (P=0.70. There was one death in conventional therapy group. No important adverse event was found in Andrographolide Sulfonate combination therapy group. Conclusions. The addition of Andrographolide Sulfonate to conventional therapy reduced the occurrence of major complications, fever clearance time, and the healing time of typical skin or oral mucosa lesions in children with severe HFMD.

Quantitative proteomic studies in resistance mechanisms of Eimeria tenella against polyether ionophores.

Science.gov (United States)

Thabet, Ahmed; Honscha, Walther; Daugschies, Arwid; Bangoura, Berit

2017-05-01

Polyether ionophores are widely used to treat and control coccidiosis in chickens. Widespread use of anticoccidials resulted in worldwide resistance. Mechanisms of resistance development and expansion are complex and poorly understood. Relative proteomic quantification using LC-MS/MS was used to compare sensitive reference strains (Ref-1, Ref-2) with putatively resistant and moderately sensitive field strains (FS-R, FS-mS) of Eimeria tenella after isotopic labelling with tandem mass tags (TMT). Ninety-seven proteins were identified, and 25 of them were regulated. Actin was significantly upregulated in resistant strains in comparison with their sensitive counterparts. On the other hand, microneme protein (MIC4) was downregulated in resistant strains. Optimization of labelling E. tenella sporozoites by TMT might identify further proteins that play a role in the obvious complex mechanism leading to resistance against Monensin.

Cationic Copolymerization of 3,3-Bis(hydroxymethyl)oxetane and Glycidol: Biocompatible Hyperbranched Polyether Polyols with High Content of Primary Hydroxyl Groups.

Science.gov (United States)

Christ, Eva-Maria; Hobernik, Dominika; Bros, Matthias; Wagner, Manfred; Frey, Holger

2015-10-12

The cationic ring-opening copolymerization of 3,3-bis(hydroxymethyl)oxetane (BHMO) with glycidol using different comonomer ratios (BHMO content from 25 to 90%) and BF3OEt2 as an initiator has been studied. Apparent molecular weights of the resulting hyperbranched polyether copolymers ranged from 1400 to 3300 g mol(-1) (PDI: 1.21-1.48; method: SEC, linear PEG standards). Incorporation of both comonomers is evidenced by MALDI-TOF mass spectroscopy. All hyperbranched polyether polyols with high content of primary hydroxyl groups portray good solubility in water, which correlates with an increasing content of glycerol units. Detailed NMR characterization was employed to elucidate the copolymer microstructures. Kinetic studies via FTIR demonstrated a weak gradient-type character of the copolymers. MTT assays of the copolymers (up to 100 μg mL(-1)) on HEK and fibroblast cell lines (3T3, L929, WEHI) as well as viability tests on the fibroblast cells were carried out to assess the biocompatibility of the materials, confirming excellent biocompatibility. Transfection efficiency characterization by flow cytometry and confocal laser microscopy demonstrated cellular uptake of the copolymers. Antiadhesive properties of the materials on surfaces were assessed by adhesion assays with fibroblast cells.

Local deformation behavior of surface porous polyether-ether-ketone.

Science.gov (United States)

Evans, Nathan T; Torstrick, F Brennan; Safranski, David L; Guldberg, Robert E; Gall, Ken

2017-01-01

Surface porous polyether-ether-ketone has the ability to maintain the tensile monotonic and cyclic strength necessary for many load bearing orthopedic applications while providing a surface that facilitates bone ingrowth; however, the relevant deformation behavior of the pore architecture in response to various loading conditions is not yet fully characterized or understood. The focus of this study was to examine the compressive and wear behavior of the surface porous architecture using micro Computed Tomography (micro CT). Pore architectures of various depths (~0.5-2.5mm) and pore sizes (212-508µm) were manufactured using a melt extrusion and porogen leaching process. Compression testing revealed that the pore architecture deforms in the typical three staged linear elastic, plastic, and densification stages characteristic of porous materials. The experimental moduli and yield strengths decreased as the porosity increased but there was no difference in properties between pore sizes. The porous architecture maintained a high degree of porosity available for bone-ingrowth at all strains. Surface porous samples showed no increase in wear rate compared to injection molded samples, with slight pore densification accompanying wear. Copyright © 2016 Elsevier Ltd. All rights reserved.

Proton Conductivity of Nafion/Ex-Situ Sulfonic Acid-Modified Stöber Silica Nanocomposite Membranes As a Function of Temperature, Silica Particles Size and Surface Modification

Science.gov (United States)

Muriithi, Beatrice; Loy, Douglas A.

2016-01-01

The introduction of sulfonic acid modified silica in Nafion nanocomposite membranes is a good method of improving the Nafion performance at high temperature and low relative humidity. Sulfonic acid-modified silica is bifunctional, with silica phase expected to offer an improvement in membranes hydration while sulfonic groups enhance proton conductivity. However, as discussed in this paper, this may not always be the case. Proton conductivity enhancement of Nafion nanocomposite membranes is very dependent on silica particle size, sometimes depending on experimental conditions, and by surface modification. In this study, Sulfonated Preconcentrated Nafion Stober Silica composites (SPNSS) were prepared by modification of Stober silica particles with mercaptopropyltriethoxysilane, dispersing the particles into a preconcentrated solution of Nafion, then casting the membranes. The mercapto groups were oxidized to sulfonic acids by heating the membranes in 10 wt % hydrogen peroxide for 1 h. At 80 °C and 100% relative humidity, a 20%–30% enhancement of proton conductivity was only observed when sulfonic acid modified particle less than 50 nm in diameter were used. At 120 °C, and 100% humidity, proton conductivity increased by 22%–42% with sulfonated particles with small particles showing the greatest enhancement. At 120 °C and 50% humidity, the sulfonated particles are less efficient at keeping the membranes hydrated, and the composites underperform Nafion and silica-Nafion nanocomposite membranes. PMID:26828525

Fate of linear alkylbenzene sulfonate (LAS) in activated sludge plants

NARCIS (Netherlands)

Temmink, B.G.; Klapwijk, A.

2004-01-01

Monitoring data were collected in a pilot-scale municipal activated sludge plant to assess the fate of the C12-homologue of linear alkyl benzene sulfonate (LAS-C12). The pilot-plant was operated at influent LAS-C12 concentrations between 2 and 12 mg/l and at sludge retention times of 10 and 27

Reaction kinetics of free fatty acids esterification in palm fatty acid distillate using coconut shell biochar sulfonated catalyst

Science.gov (United States)

Hidayat, Arif; Rochmadi, Wijaya, Karna; Budiman, Arief

2015-12-01

Recently, a new strategy of preparing novel carbon-based solid acids has been developed. In this research, the esterification reactions of Palm Fatty Acid Distillate (PFAD) with methanol, using coconut shell biochar sulfonated catalyst from biomass wastes as catalyst, were studied. In this study, the coconut shell biochar sulfonated catalysts were synthesized by sulfonating the coconut shell biochar using concentrated H2SO4. The kinetics of free fatty acid (FFA) esterification in PFAD using a coconut shell biochar sulfonated catalyst was also studied. The effects of the mass ratio of catalyst to oil (1-10%), the molar ratio of methanol to oil (6:1-12:1), and the reaction temperature (40-60°C) were studied for the conversion of PFAD to optimize the reaction conditions. The results showed that the optimal conditions were an methanol to PFAD molar ratio of 12:1, the amount of catalyst of 10%w, and reaction temperature of 60°C. The proposed kinetic model shows a reversible second order reaction and represents all the experimental data satisfactorily, providing deeper insight into the kinetics of the reaction.

Radiation curable coatings containing hydroxy functional polyethers and polyesters of monoethylenic acids or hydroxy esters thereof

International Nuclear Information System (INIS)

Kaufman, M.L.

1978-01-01

Relatively water insoluble hydroxy functional monoethylenic polyethers or polyesters of monoethylenic carboxylic acids or hydroxy alkyl esters thereof are formed by adducting the monoethylenic acid or its hydroxy ester with an anhydride selected from monoepoxides, lactones, or mixtures thereof in the presence of a Lewis acid catalyst, such as BF 3 etherate, at a temperature below that at which the unsaturation is consumed, typically about 30 to 70 0 C. These adducts are of low volatility and of low toxicity and can be radiation cured in admixture with polyacrylates to form coatings having improved resistance to elevated temperature exposure

Design and synthesis of polycyclic sulfones via Diels-Alder reaction and ring-rearrangement metathesis as key steps.

Science.gov (United States)

Kotha, Sambasivarao; Gunta, Rama

2015-01-01

Here, we describe a new and simple synthetic strategy to various polycyclic sulfones via Diels-Alder reaction and ring-rearrangement metathesis (RRM) as the key steps. This approach delivers tri- and tetracyclic sulfones with six (n = 1), seven (n = 2) or eight-membered (n = 3) fused-ring systems containing trans-ring junctions unlike the conventional all cis-ring junctions generally obtained during the RRM sequence. Interestingly the starting materials used are simple and commercially available.

Probing the Conformational Landscape of Polyether Building Blocks in Supersonic Jets

Science.gov (United States)

Bocklitz, Sebastian; Hewett, Daniel M.; Zwier, Timothy S.; Suhm, Martin A.

2016-06-01

Polyethylene oxides (Polyethylene glycoles) and their phenoxy-capped analogs represent a prominent class of important polymers that are highly used as precursor molecules in supramolecular reactions. After a detailed study on the simplest representative (1,2-dimethoxyethane) [1], we present results on oligoethylene oxides with increasing chain lengths obtained by spontaneous Raman scattering in a supersonic jet. Through variation of stagnation pressure, carrier gas, nozzle distance and temperature we gain information on the conformational landscape as well as the mutual interconversion of low energy conformers. The obtained results are compared to state-of-the-art quantum chemical calculations. Additionally, we present UV as well as IR-UV and UV-UV double resonance studies on 1-methoxy-2-phenoxyethane in a supersonic jet. These complementary techniques allow for conformationally selective electronic and vibrational spectra in a closely related conformational landscape. [1] S. Bocklitz, M. A. Suhm, Constraining the Conformational Landscape of a Polyether Building Block by Raman Jet Spectroscopy, Z. Phys. Chem. 2015, 229, 1625-1648.

Low-temperature direct heterogeneous bonding of polyether ether ketone and platinum.

Science.gov (United States)

Fu, Weixin; Shigetou, Akitsu; Shoji, Shuichi; Mizuno, Jun

2017-10-01

Direct heterogeneous bonding between polyether ether ketone (PEEK) and Pt was realized at the temperatures lower than 150°C. In order to create sufficient bondability to diverse materials, the surface was modified by vacuum ultraviolet (VUV) irradiation, which formed hydrate bridges. For comparison, direct bonding between surfaces atomically cleaned via Ar fast atom bombardment (FAB) was conducted in a vacuum. The VUV irradiation was found to be effective for creating an ultrathin hydrate bridge layer from the residual water molecules in the chamber. Tight bonds were formed through dehydration of the hydrate bridges by heating at 150°C, which also contributed to enhancing interdiffusion across the interface. The VUV-modified surfaces showed bondability as good as that of the FAB-treated surfaces, and the VUV-modified samples had shear strengths at the same level as those of FAB-treated surfaces. This technology will be of practical use in the packaging of lightweight, flexible biomedical devices. Copyright © 2017 Elsevier B.V. All rights reserved.

Patterning of electrically conductive poly(aniline-co-aniline sulfonic acid) and its application in the immobilization of cytochrome c

International Nuclear Information System (INIS)

Oh, Se Young; Oh, Il Soo; Choi, Jeong-Woo

2004-01-01

We have synthesized poly(aniline-co-aniline sulfonic acid) and then investigated the feasibility of application as a specific and electrically conductive binding template for biomolecules. Poly(aniline-co-aniline sulfonic acid)s were prepared by oxidation polymerization of aniline and aniline sulfonic acid under various ratios. A fine pattern of the conducting copolyaniline was obtained by using a deep UV lithographic technique. Cytochrome c was immobilized onto the photochemically patterned conducting copolyaniline with a self-assembly method. Physical and electrochemical properties of the self-assembled cytochrome c monolayer were studied from atomic force microscopy and cyclic voltammetry. The self-assembled cytochrome c monolayer immobilized onto the copolyaniline with a high electrical conductivity showed a high electrochemical activity

Membranes of polyindene sulfonated and PVA for use as polymer electrolyte; Membranas mistas de poli(indeno) sulfonado e PVA para uso como eletrolito polimerico

Energy Technology Data Exchange (ETDEWEB)

Loser, N.; Silva, B.B.R. da; Brum, F.J.B.; Forte, M.M.C. [Universidade Federal do Rio Grande do Sul - Escola de Engenharia, Porto Alegre, RS (Brazil)

2010-07-01

This study is focused on developing polymer poly electrolytes for fuel cell PEM and aims to evaluate the efficiency of sulfonated polyindene as A polymer electrolyte in blends with poly (vinyl alcohol) (PVA). For this, polyindene synthesized in the lab was functionalized with sulfonic groups (-SO{sub 3}H), using as sulfonation agent acetyl sulfate in 1,2-dichloroethane. The membranes of sulfonated polyindene (SPInd) and PVA were prepared in aqueous medium, using glutaraldehyde as a PVA cross linker. The membranes SPInd/PVA were evaluated on the content of sulfonic groups, ion exchange capacity (IEC), degree of swelling in water and thermal stability (TGA). Electrochemical impedance analysis was used for ionic conductivity evaluation and DMA for the mechanical strength of the membranes. Preliminary results show that the membranes showed ion exchange capacity about 3.2 m equiv/g and degree of swelling in water of 550%. (author)

Sulfonated poly(tetramethydiphenyl ether ether ketone) membranes for vanadium redox flow battery application

Energy Technology Data Exchange (ETDEWEB)

Mai, Zhensheng; Bi, Cheng; Dai, Hua [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100039 (China); Zhang, Huamin; Li, Xianfeng [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China)

2011-01-01

Sulfonated poly(tetramethydiphenyl ether ether ketone) (SPEEK) with various degree of sulfonation is prepared and first used as ion exchange membrane for vanadium redox flow battery (VRB) application. The vanadium ion permeability of SPEEK40 membrane is one order of magnitude lower than that of Nafion 115 membrane. The low cost SPEEK membranes exhibit a better performance than Nafion at the same operating condition. VRB single cells with SPEEK membranes show very high energy efficiency (>84%), comparable to that of the Nafion, but at much higher columbic efficiency (>97%). In the self-discharge test, the duration of the cell with the SPEEK membrane is two times longer than that with Nafion 115. The membrane keeps a stable performance after 80-cycles charge-discharge test. (author)

Animated sulfonated or sulformethylated lignins as cement fluid loss control additives

Energy Technology Data Exchange (ETDEWEB)

Schilling, P.

1991-05-07

This patent describes a method of cementing a zone in a well penetrating a subterranean formation comprising injecting down the well and positioning in the zone to be cemented a hydraulic aqueous cement slurry composition. It comprises: a hydraulic cement, and the following expressed as parts by weight per 100 parts of the hydraulic cement, water from about 25 to 105 parts, and a fluid loss control additive comprising from about 0.5 to 2.5 parts of a compound selected from the group consisting of a sulfonated lignin and a sulfomethylated lignin, wherein the lignin has been aminated by reacting it with between about 2-5 moles of a polyamine and 2-5 moles of an aldehyde per 1,000g of the lignin, and 0.1 to 1.5 parts of a compound selected from the group consisting of sodium carbonate, sodium metasilicate, sodium phosphate, sodium sulfite and sodium naphthalene sulfonate and a combination thereof.

Quantitative structure–reactivity study on sulfonation of amines, alcohols and phenols

Directory of Open Access Journals (Sweden)

Abolghasem Beheshti

2017-05-01

Full Text Available Quantitative structure–reactivity relationship (QSRR can be considered as a variant of quantitative structure property relationship (QSPR studies, where the chemical reactivity of reactants in a specified chemical reaction is related to chemical structure. As follows, the sulfonation reaction yield of 24 amines, alcohols and phenols with sulfonyl chloride was studied by QSRR. Quantum chemical calculations (b3lyp/6-31+g (d were carried out to obtain the optimized geometry. The suitable set of molecular descriptors was calculated to represent the molecular structures of compounds, such as constitutional, topological, geometrical, electrostatic and quantum-chemical descriptors. The genetic algorithm (GA was applied to select the variables that resulted in the best-fitted models. After the variable selection, multiple linear regression (MLR was utilized to construct linear QSRR models. The maximum relative error in prediction (5.26 showed that the predictive ability of the model was satisfactory and it can be used for designing similar reactants with efficient sulfonation reaction.

Deciphering the Role of Sulfonated Unit in Heparin-Mimicking Polymer to Promote Neural Differentiation of Embryonic Stem Cells.

Science.gov (United States)

Lei, Jiehua; Yuan, Yuqi; Lyu, Zhonglin; Wang, Mengmeng; Liu, Qi; Wang, Hongwei; Yuan, Lin; Chen, Hong

2017-08-30

Glycosaminoglycans (GAGs), especially heparin and heparan sulfate (HS), hold great potential for inducing the neural differentiation of embryonic stem cells (ESCs) and have brought new hope for the treatment of neurological diseases. However, the disadvantages of natural heparin/HS, such as difficulty in isolating them with a sufficient amount, highly heterogeneous structure, and the risk of immune responses, have limited their further therapeutic applications. Thus, there is a great demand for stable, controllable, and well-defined synthetic alternatives of heparin/HS with more effective biological functions. In this study, based upon a previously proposed unit-recombination strategy, several heparin-mimicking polymers were synthesized by integrating glucosamine-like 2-methacrylamido glucopyranose monomers (MAG) with three sulfonated units in different structural forms, and their effects on cell proliferation, the pluripotency, and the differentiation of ESCs were carefully studied. The results showed that all the copolymers had good cytocompatibility and displayed much better bioactivity in promoting the neural differentiation of ESCs as compared to natural heparin; copolymers with different sulfonated units exhibited different levels of promoting ability; among them, copolymer with 3-sulfopropyl acrylate (SPA) as a sulfonated unit was the most potent in promoting the neural differentiation of ESCs; the promoting effect is dependent on the molecular weight and concentration of P(MAG-co-SPA), with the highest levels occurring at the intermediate molecular weight and concentration. These results clearly demonstrated that the sulfonated unit in the copolymers played an important role in determining the promoting effect on ESCs' neural differentiation; SPA was identified as the most potent sulfonated unit for copolymer with the strongest promoting ability. The possible reason for sulfonated unit structure as a vital factor influencing the ability of the copolymers

SORPTION OF Ga (III ON FLEXIBLE OPEN CELL POLYURETHANE FOAM OF POLYETHER TYPE IMPREGNATED WITH TRI-N-BUTHYL PHOSPATE

Directory of Open Access Journals (Sweden)

Lavinia Tofan

2007-06-01

Full Text Available The obtained results concerning the Ga (III ion retention on flexible open cell polyurethane foam of polyether type pretreated with tri-n-butyl phosphate are presented. The influence of solution acidity, phases contact time, Ga (III concentration and solution temperature have been investigated. The parameters of Ga (III batch sorption have been optimized. On the basis of Langmuir isotherms, the sorption constants and the thermodynamic parameters, ∆G, ∆Η and ∆S have been calculated.

Quinolinium 8-hy-droxy-7-iodo-quinoline-5-sulfonate 0.8-hydrate.

Science.gov (United States)

Smith, Graham

2012-12-01

In the crystal structure of the title hydrated quinolinium salt of ferron (8-hy-droxy-7-iodo-quinoline-5-sulfonic acid), C9H7N(+)·C9H5INO4S(-)·0.8H2O, the quinolinium cation is fully disordered over two sites (occupancy factors fixed at 0.63 and 0.37) lying essentially within a common plane and with the ferron anions forming π-π-associated stacks down the b axis [minimum ring centroid separation = 3.462 (6) Å]. The cations and anions are linked into chains extending along c through hy-droxy O-H⋯O and quinolinium N-H⋯O hydrogen bonds to sulfonate O-atom acceptors which are also involved in water O-H⋯O hydrogen-bonding inter-actions along b, giving a two-dimensional network.

Sulfonated hydrocarbon graft architectures for cation exchange membranes

DEFF Research Database (Denmark)

Nielsen, Mads Møller; Jankova Atanasova, Katja; Hvilsted, Søren

2013-01-01

A synthetic strategy to hydrocarbon graft architectures prepared from a commercial polysulfone and aimed as ion exchange membrane material is proposed. Polystyrene is grafted from a polysulfone macroinitiator by atom transfer radical polymerization, and subsequently sulfonated with acetyl sulfate...... to various degrees. Series of grafting densities and graft lengths are prepared, and membranes are solvent cast from DMSO. The membrane properties in aqueous environments are evaluated from their water swelling behavior, and their thermal properties and stability are investigated by thermogravimetric...