Biodegradable Interpolyelectrolyte Complexes Based on Methoxy Poly(ethylene glycol)-b-poly(alpha,L-glutamic acid) and Chitosan

We synthesized methoxy poly(ethylene glycol)-b-poly(alpha,L-glutamic acid) (mPEGGA) diblock copolymer by ring-opening polymerization of N-carboxy anhydride of gamma-benzyl-L-glutamate (NCA) using amino-terminated methoxy polyethylene glycol (mPEG) as macroinitiator. Polyelectrolyte complexation between mPEGGA as neutral-block-polyanion and chitosan (CS) as polycation has been scrutinized in aqueous solution as well as in the solid state.

Facile preparation of water-soluble fluorescent silver nanoclusters using a polyelectrolyte template

We report a new approach for the synthesis of fluorescent and water-soluble Ag nanoclusters, using the common polyelectrolyte poly(methacrylic acid) as the template.

Properties of poly(sodium 4-styrenesulfonate)-ionic liquid composite film and its application in the determination of trace metals combined with bismuth film electrode

A new kind of bismuth film modified electrode to sensitively detect trace metal ions based on incorporating highly conductive ionic liquids 1-butyl-3-methyl-imidazolium hexafluorophosphate (BMIMPF6) in solid matrices at glassy carbon (GC) was investigated. Poly(sodium 4-styrenesulfonate) (PSS), silica, and Nafion were selected as the solid matrices. The electrochemical properties of the mixed films modified GC were evaluated. The electron transfer rate of Fe(CN)(6)(4-)/Fe(CN)(6)(3-) can be effectively improved at the PSS-BMIMPF6 modified GC.

Thermoplastic Elastomers Based on Compatibilized Poly(butylene terephthalate) Blends: Effect of Functional Groups and Dynamic Curing

Two sets of graft copolymers were prepared by grafting glycidyl methacrylate (GMA) or ally] (3-isocyanate-4-tolyl) carbamate (TAI) onto ethylene/propylene/diene terpolymer (EPDM) in an internal mixer. These graft copolymers were used as the compatibilizer to prepare the thermoplastic elastomers (TPEs) containing 50 wt%, of poly(butylene terephthalate), PBT, 30 wt% of compatibilizer, and 20 wt% of nitrile-butadiene rubber, NBR. The indirect, two-step mixer process was chosen for dynamic curing.

An effective method for enhancing metal-ions' selectivity of ionic liquid-based extraction system: Adding water-soluble complexing agent

Selective extraction-separation of yttrium(Ill) from heavy lanthanides into 1-octyl-3-methylimidazolium hexafluorophosphate ([C(8)mim][PF6]) containing Cyanex 923 was achieved by adding a water-soluble complexing agent (EDTA) to aqueous phase. The simple and environmentally benign complexing method was proved to be an effective strategy for enhancing the selectivity of [C(n)mim] [PF6]/[Tf2N]-based extraction system without increasing the loss of [C(n)mim](+). (c) 2007 Elsevier B.V. All rights reserved.

Synthesis and properties of sulfonated poly[bis(benzimidazobenzisoquinolinones)] as hydrolytically and thermooxidatively stable proton conducting ionomers

Novel sulfonated poly [bis(benzimidazobenzisoquinolinones)] as hydrolytically and thermooxidatively stable electrolyte for high -temperature fuel cell applications are reported. A series of sulfonated polymers (SPBIBI-x, x refers to molar percentage of sulfonated dianhydride monomer) were synthesized from 6,6'-disulfonic-4,4'-binaphthyl-1,1',8,8'-tetracarboxylic dianhydride (SBTDA), 4,4-binaphthyl-1,1,8,8-tetracarboxylic dianhydride (BTDA), and 3,3'-diaminobenzidine. The chemical structures of those polymers as well as model compounds synthesized from SBTDA and o-phenylenediamine were confirmed by nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR).

Synthesis of sulfonated poly(arylene-co-naphthalimide)s as novel polymers for proton exchange membranes

A series of novel sulfonated poly(arylene-co-binaphthalimide)s (SPPIs) were successfully synthesized via Ni(0) catalytic coupling of sodium 3-(2,5-dichlorobenzoyl)benzenesulfonate and bis(chloronaphthalimide)s. Bis(chloronaphthalimide)s were conveniently prepared from 5-chloro-1,8-naphthalic anhydride and various diamines. Tough and transparent SPPI membranes were prepared and the electrolyte properties of the copolymers were intensively investigated as were the effects of different diamine structures on the copolymer characterisitics. The copolymer membrane Ia-80, with an ion exchange capacity (IEC) of 2.50 meq g(-1), displayed a higher proton conductivity, i.e. 0.135 S cm(-1) at 20 degrees C, as compared to Nafion 117 (0.09 S cm(-1), 20 degrees C).

Synthesis of isomeric bis(amine anhydride)s for novel poly(amine imide)s by Pd-catalyzed amination of 4-chlorophthalic anhydride

Two novel bis(amine anhydride) monomers, N,N'-bis(3,4-dicarboxyphenyl)-1,4-phenylenediamine dianhydride I and N,/N'-bis(3,4-dicarboxyphenyl)-1,3-phenylenediamine dianhydride 11, were prepared via palladium-catalyzed amination reaction of 4-chloro-N-methylphthaliniide with 1,4-phenylenediamine or 1,3-phenylenediamine, followed by alkaline hydrolysis of the intermediate bis(amine imide)s and subsequent dehydration of the resulting tetraacids. A series of new poly(amine imide)s were prepared from the synthesized dianhydride monomers with various diamines in NMP via conventional two-step method.

Sulfonated poly(arylene-co-imide)s as water stable proton exchange membrane materials for fuel cells

A novel sulfonated poly(arylene-co-imide)s were synthesized by Ni(0) catalytic copolymerization of sodium 3-(2,5-dichlorobenzoyl)benzenesulfonate and naphthalimide dichloride monomer. The synthesized copolymers with the - SO3H group on the side-chain of polymers possessed high molecular weights revealed by their high viscosity and the formation of tough and flexible membranes. Because of the introduction of electron donating phenoxy groups into naphthalimide moieties, the hydrolysis of the imide rings was depressed. The resulting copolymers exhibited excellent water stability. The copolymer membranes display no apparently change in appearance, flexibility, and toughness after a soaking treatment in pressurized water at 140 degrees C for 250 h.

Crystallization behavior of a thermoplastic polyimide derived from 3,3 ',4,4 '-oxydiphthalic dianhydride and 4,4 '-oxydianiline

Nonisothermal and isothermal crystallization kinetics of an aromatic thermoplastic polyimide derived from 3,3',4,4'-oxydiphthalic dianhydride and 4,4'-oxydianiline have been investigated by means of differential scanning calorimetry (DSC) and wide-angle X-ray diffraction. The results for nonisothermal crystallization study showed that a weak melting peak appeared during the first heating process, whereas no crystallization peak appeared in the DSC curve during the subsequent cooling process. On the other hand, the study for the isothermal crystallization in the temperature range of 260-330 degrees C showed that a new exothermic peak appeared at lower temperature for the samples crystallized for 100 min at 300 degrees C.

Microchip Micellar Electrokinetic Chromatography Based on One Functionalized Ionic Liquid and Its Excellent Performance on Proteins Separation

Herein, one water-soluble functionalized ionic liquid (IL), 1-butyl-3-methylimidazolium dodecanesulfonate (BAS), was designed, investigated and successfully applied to microchip micellar electrokinetic chromatography (MEKC) construction. It possessed the properties of both IL and surfactant. A fairly stable pH value similar to 7.4, which was fit to pH values of general biological buffers, was nicely placed at the optimum concentration of 20 mM BAS solution. While applying BAS solution as running buffer in poly(dimethylsiloxane) (PDMS) microfluidic systems, significantly enhanced electroosmotic flow (8-fold) and resolutions between analytes were obtained than that using other supporting electrolytes or surfactants.

Sensitive, Label-Free Protein Assay Using 1-ethyl-3-methylimidazolium Tetrafluoroborate Supported Microchip Electrophoresis with Laser-Induced Fluorescence Detection

Based on the dimer-monomer equilibrium movement of the fluorescent dye Pyronin Y (PY), a rapid, simple, highly sensitive, label-free method for protein detection was developed by microchip electrophoresis with LIF detection. PY formed a nonfluorescent dimer induced by the premicellar aggregation of an anionic surfactant, SDS, however, the fluorescence intensity of the system increased dramatically when proteins such as BSA, bovine hemoglobin, cytochrome c, and trypsin were added to the solution due to the transition of dimer to fluorescent monomer. Furthermore, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF(4)) instead of PBS was applied as running buffers in microchip electrophoresis.

Synthesis, characterization, and electroluminescence of PPV copolymers containing electron and hole-transporting units

Three series of poly(phenylene vinylene) (PPV) derivatives containing hole-transporting triphenylamine derivatives [N-(4-octoxylphenyl)diphenylamine, N,N'-di(4-octyloxylphenyl)-N,N'-diphenyl-1,4-phenylenediamine, and N,N'-di(4-octoxylphenyl)-N,N'-diphenylbenzidine] (donor) and electron-transporting oxadiazole unit (2,5-diphenyl-1,3,4-oxadiazole) (acceptor) in the main chain were synthesized by improved Wittig copolymerization. The resulting donor-acceptor (D-A) polymers are readily soluble in common organic solvents, such as chloroform, dichloroethane, THF, and toluene.

Near-infrared polymer light-emitting diodes based on infrared dye doped poly(N-vinylcarbazole) film

Infrared light-emitting diodes possess potential applications in optical communication and safety detection. in this paper, we fabricated near-infrared light-emitting diodes possess potential applications in optical communication and safety detection. in this paper, we fabricated near-infrared polymer light-emitting diode employing a commercial near-infrared (NIR) organic dye as an emissive dopant dispersed within poly(N-vinylcarbazole) (PVK) by spin-casting method. The used device structure was indium tin oxide/3,4-polyethylene-dioxythiophene-polystyrene sulfonate/PVK: NIR dye/Al.

Synthesis and characterization of novel biodegradable poly(carbonate ester)s with photolabile protecting groups

Novel biodegradable poly(carbonate ester)s with photolabile protecting groups were synthesized by ring-opening copolymerization Of L-lactide (LA) with 5-methyl-5-(2-nitro-benzoxycarbonyl)-1,3-dioxan-2-one (MNC) with diethyl zinc (Et2Zn) as catalyst. The poly(L-lactide-co-5-methyl-5-carboxyl-1,3-dioxan-2-one) (P(LA-co-MCC)) was obtained by UV irradiation Of poly(L-lactide acid-co-5-methyl-5-(2-nitro-benzoxycarbonyl)-1,3-dioxan-2-one) (P(LA-co-MNC)) to remove the protective 2-nitrobenzyl group.