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New Polymers (new + polymer)
Selected AbstractsOne-Pot Preparation of Polymer,Enzyme,Metallic Nanoparticle Composite Films for High-Performance Biosensing of Glucose and GalactoseADVANCED FUNCTIONAL MATERIALS, Issue 11 2009Yingchun Fu Abstract New polymer,enzyme,metallic nanoparticle composite films with a high-load and a high-activity of immobilized enzymes and obvious electrocatalysis/nano-enhancement effects for biosensing of glucose and galactose are designed and prepared by a one-pot chemical pre-synthesis/electropolymerization (CPSE) protocol. Dopamine (DA) as a reductant and a monomer, glucose oxidase (GOx) or galactose oxidase (GaOx) as the enzyme, and HAuCl4 or H2PtCl6 as an oxidant to trigger DA polymerization and the source of metallic nanoparticles, are mixed to yield polymeric bionanocomposites (PBNCs), which are then anchored on the electrode by electropolymerization of the remaining DA monomer. The prepared PBNC material has good biocompatibility, a highly uniform dispersion of the nanoparticles with a narrow size distribution, and high load/activity of the immobilized enzymes, as verified by transmission/scanning electron microscopy and electrochemical quartz crystal microbalance. The thus-prepared enzyme electrodes show a largely improved amperometric biosensing performance, e.g., a very high detection sensitivity (99 or 129,µA cm,2 mM,1 for glucose for Pt PBNCs on bare or platinized Au), a sub-micromolar limit of detection for glucose, and an excellent durability, in comparison with those based on conventional procedures. Also, the PBNC-based enzyme electrodes work well in the second-generation biosensing mode. The proposed one-pot CPSE protocol may be extended to the preparation of many other functionalized PBNCs for wide applications. [source] Reduction of dissolved oxygen in boiler water using new redox polymersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2010Christophe Waterlot Abstract New polymers were used as catalysts for the removal of dissolved oxygen in boiler water. These polymers, based upon hydroquinone-quinone redox system, were prepared by polymerization of methyl 4-(2,5-dimethoxybenzyl)cinnamate and copolymerization of this monomer with 4-(4,-vinylphenethyl)-1,10-phenanthroline. The resulting product was used to synthesize polymers containing transition metal ions. Nuclear magnetic resonance, infrared spectroscopy, and elemental analysis were achieved to characterize monomers and/or electron-transfer polymers. These polymers were used for the removal of oxygen from water. It was shown that the oxygen content was reduced to less than 0.1 mg L,1 in , 70 s. Based on the obtained results, the redox capacity of two polymers were determined. It was established that the poly-4-(2,5-dihydroxybenzyl)cinnamic acid reached a redox capacity of 69.7 mg of O2 per gram of polymer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Polymer chemistry in flow: New polymers, beads, capsules, and fibersJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2006Jeremy L. Steinbacher Abstract The union between polymer science and microfluidics is reviewed. Fluids in microreactors allow the synthesis of a wide range of polymeric materials with unique properties. We begin by discussing the important fluid dynamics that dominate the behavior of fluids on the micrometer scale. We then progress through a comprehensive analysis of the polymeric materials synthesized to date. This highlight concludes with an overview of the methods used to make microreactors. We enthusiastically endorse microreactors as a powerful approach to making materials with controlled properties, although we have tried to provide a critical eye to help the nonexpert enter the field. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6505,6533, 2006 [source] Synthesis and characterization of novel poly(arylenevinylene) derivativeJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2008Song Se-Yong Abstract The new poly(arylenevinylene) derivative composed naphthalene phenylene vinylene backbone was developed. The theoretical calculation showed that the model compound of the obtained polymer was highly distorted between the stryl and naphthalene units as well as between the backbone and fluorene side units. The polymer was synthesized by the palladium catalyzed Suzuki coupling reaction with 2,6-(1,,2,-ethylborate)-1,5-dihexyloxynaphtalene and 1,2-bis(4,-bromophenyl)-1-(9,,9,-dihexyl-3-fluorenyl)ethene. The structure of the polymer was confirmed by 1H NMR, IR, and elemental analysis. The weight,average molecular weight of the polymer is 29,800 with the polydispersity index of 1.87. The new polymer showed good thermal stability with high Tg of 195°C. The bright blue fluorescence (,max = 475 nm) was observed both in solution and film of new polymer with naphthalene phenylene vinylene backbone. Double layer LED devices with the configuration of ITO/PEDOT/polymer/LiF/Ca/Al showed a turn-on voltage at around 4.5 V, the maximum luminance of 150 cd/m2, and the maximum efficiency of 0.1 cd/A. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Synthesis and characterization of a thiadiazole/benzoimidazole-based copolymer for solar cell applicationsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2010Guan-yu Chen Abstract In this study, we synthesized a new polymer, PCTDBI, containing alternating carbazole and thiadiazole-benzoimidazole (TDBI) units. This polymer (number-average molecular weight = 25,600 g mol,1), which features a planar imidazole structure into the polymeric main chain, possesses reasonably good thermal properties (Tg = 105 °C; Td = 396 °C) and an optical band gap of 1.75 eV that matches the maximum photon flux of sunlight. Electrochemical measurements revealed an appropriate energy band offset between the polymer's lowest unoccupied molecular orbital and that of PCBM, thereby allowing efficient electron transfer between the two species. A solar cell device incorporating PCTDBI and PCBM at a blend ratio of 1:2 (w/w) exhibited a power conversion efficiency of 1.20%; the corresponding device incorporating PCTDBI and PC71BM (1:2, w/w) exhibited a PCE of 1.84%. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 [source] Synthesis and NMR characterization of 6-Phenyl-6-deoxy-2,3-di- O -methylcellulose,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 6 2002Dr Navzer (Nozar) D. Sachinvala Abstract Cellulose (1) was converted for the first time to 6-phenyl-6-deoxy-2,3-di- O -methylcellulose (6) in 33% overall yield. Intermediates in the five-step conversion of 1 to6 were: 6- O -tritylcellulose (2), 6- O -trityl-2,3-di- O -methylcellulose (3), 2,3-di- O -methylcellulose (4); and 6-bromo-6-deoxy-2,3-di- O -methylcellulose (5). Elemental and quantitative carbon-13 analyses were concurrently used to verify and confirm the degrees of substitution in each new polymer. Gel permeation chromotography (GPC) data were generated to monitor the changes in molecular weight (DPw) as the synthesis progressed, and the compound average decrease in cellulose DPw was , 27%. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterize the decomposition of all polymers. The degradation temperatures (,°C) and percent char at 500,°C of cellulose derivatives 2 to 6 were 308.6 and 6.3%, 227.6,°C and 9.7%, 273.9,°C and 30.2%, 200.4,°C and 25.6%, and 207.2,°C and 27.0%, respectively. The glass transition temperature (Tg) of6- O -tritylcellulose by dynamic mechanical analysis (DMA) occurred at 126.7,°C and the modulus (E,, Pa) dropped 8.9 fold in the transition from ,150,°C to,+,180,°C (6.6,×,109 to 7.4,×,108 Pa). Modulus at 20,°C was 3.26,×,109 Pa. Complete proton and carbon-13 chemical shift assignments of the repeating unit of the title polymer were made by a combination of the HMQC and COSY NMR methods. Ultimate non-destructive proof of carbon,carbon bond formation at C6 of the anhydroglucose moiety was established by generating correlations between resonances of CH26 (anhydroglucose) and C1,, H2,, and H6, of the attached aryl ring using the heteronuclear multiple-bond correlation (HMBC) method. In this study, we achieved three major objectives: (a) new methodologies for the chemical modification of cellulose were developed; (b) new cellulose derivatives were designed, prepared and characterized; (c) unequivocal structural proof for carbon,carbon bond formation with cellulose was derived non-destructively by use of one- and two-dimensional NMR methods. Copyright © 2002 John Wiley & Sons, Ltd. [source] Copolymers of Cyclopentadithiophene and Electron-Deficient Aromatic Units Designed for Photovoltaic ApplicationsADVANCED FUNCTIONAL MATERIALS, Issue 20 2009Johan C. Bijleveld Abstract Alternating copolymers based on cyclopentadithiophene (CPDT) and five different electron-deficient aromatic units with reduced optical band gaps are synthesized via Suzuki coupling. All polymers show a significant photovoltaic response when mixed with a fullerene acceptor. The frontier orbital levels of the new polymers are designed to minimize energy losses by increasing the open-circuit voltage with respect to the optical band gap, while maintaining a high coverage of the absorption with the solar spectrum. The best cells are obtained for a copolymer of CPDT and benzooxadiazole (BO) with a band gap of 1.47,eV. This cell gives a short-circuit current of 5.4,mA cm,2, an open-circuit voltage of 0.78,V, and a fill factor of 0.6, resulting in a power conversion efficiency of about 2.5%. [source] Assembling DNA into Advanced Materials: From Nanostructured Films to Biosensing and Delivery Systems,ADVANCED MATERIALS, Issue 21 2007Abstract The past decade has witnessed a rapid expansion in the design and assembly of engineered materials for biological applications. However, such applications place limitations on the molecular building blocks that can be used. Requirements for polymer-based building blocks include biocompatibility, biodegradability, and stimuli-responsive behavior. Many traditional polymers used in materials science are limited in at least one of these areas, so new polymers need to be explored. As we outline here, DNA is one such polymer that shows promise in developing the next generation of ,smart' materials for biomedical and diagnostic applications. [source] Hyperbranched cyclic and multicyclic polymers by "a2+b4" polycondensationsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2009Hans R. Kricheldorf Abstract At first, theoretical aspects of "a2+b4" polycondensations (meaning polycondensations of difunctional and tetrafunctional monomers) are discussed and compared with what is known about "a2+b3" polycondensations. The following review of experimental results is subdivided into three sections. First, syntheses of hyperbranched polyethers and polyesters by polycondensations based on equimolar feed ratios will be reported. Second, kinetically controlled (i.e., irreversible) syntheses of multicyclic polymers using equifunctional feed ratios (i.e., a2/b4 ratios of 2:1) will be described. In the third section, syntheses of multicyclic polymers via thermodynamically controlled (reversible) "a2+b4" polycondensations will be discussed. Characteristic for these polycondensations are again equifunctional feed ratios and metal alkoxides as "a2" or "b4" monomers, which catalyze rapid equilibration reactions. Finally, potential applications of the new polymers will shortly be mentioned. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1971,1987, 2009 [source] Catalytic reactions of oxetanes with protonic reagents and aprotic reagents leading to novel polymersJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2007Hiroto Kudo Abstract This paper reports new addition reactions of oxetanes with certain protonic reagents such as carboxylic acid, phenol, and thiol, and with certain aprotic reagents such as acyl chloride, thioester, phosphonyl dichloride, silyl chloride, and chloroformate using quaternary onium salts as catalysts. The kinetic study of the addition reactions of oxetanes was also investigated. These new addition reactions were applicable to the synthesis of new polymers. These polyaddition systems could also construct both polymer main chains and reactive side chains. The alternating copolymerization of oxetanes with carboxylic anhydride was performed. Furthermore, it was found that anionic ring-opening polymerization of oxetanes containing hydroxy groups proceeded to afford the hyperbranched polymer (HBP) with an oxetanyl group and many hydroxy groups at the ends of the polymer chains. Alkali developable photofunctional HBPs were synthesized by the polyaddition of bis(oxetane)s or tris(oxetane)s, and their patterning properties were examined, too. The photo-induced cationic polymerization of the polymers with pendant oxetanyl groups and the thermal curing reactions of polyfunctional oxetanes (oxetane resins) were also examined to give the crosslinking materials quantitatively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 709,726, 2007 [source] Dual Tuning of Emission Color and Electron Injection Properties Through in-situ Chemical Reaction in a Conjugated Polymer Containing 9,10-PhenanthrenequinoneMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 23 2009Zhiming Wang Abstract Three new polymers were obtained through an in situ chemical reaction of the matrix conjugated polymer (PPQF) with ortho- amine compounds. By controlling the conjugation degree of diamine compounds, the emission of PPQF was tuned from weak blue to bright blue, green, and orange for PFBQ, PFBP and PFNP, respectively. The photoluminescence efficiencies were also improved in the same tendency, and the LUMO levels were gradually decreased from ,2.76 and ,3.12 to ,3.40,eV, which was beneficial for electron injection and transport in electronic devices. Thus, a dual tuning for the emission color and electron injection properties were realized through an in situ chemical reaction, which is a novel strategy to design and construct new valuable polymers from one reactive matrix polymer. [source] Trends in industrial polymer researchMACROMOLECULAR SYMPOSIA, Issue 1 2003Volker Warzelhan Abstract In the past decades a shift in paradigm took place in industrial polymer research for structural materials. Only a few new polymers based on new monomeric building blocks were developed. The main focus is now on tailoring improved "old polymers" with well-defined structure and properties based on a set of low cost "old" monomers using controlled polymerization mechanisms. [source] Spectroelectrochemical study of N -ethyl-carbazole in the presence of acrylamidePOLYMER INTERNATIONAL, Issue 3 2001Ö Yavuz Abstract Polymerization of N -ethylcarbazole (NECz) in the presence of acrylamide (AAm) has been investigated by in situ and ex situ UV,visible spectrophotometric measurements to obtain information about the reaction pathway, because NECz gives soluble oligomeric species allowing such measurements. A tentative mechanism is proposed in the light of these results. The redox properties of the new polymers have been studied for possible sensor application. © 2001 Society of Chemical Industry [source] | ||||||||||||||||||||||