Reactive and Functional Polymers (v.68, #7)
Editors and Editorial Board (IFC).
Enhanced properties in chemically polymerized poly(terthiophene) using vapour phase techniques by P.M. Bayley; B. Winther-Jensen; D.R. MacFarlane; N.M. Rocher; M. Forsyth (1119-1126).
Poly(terthiophene) is an electronically conducting polymer with potential applications in solar energy devices. In the present study a series of poly(terthiophene) (PTTh) films are chemically polymerized (CP) at various temperatures and compared with a novel method of vapour phase polymerization (VPP). Utilizing the thiophene trimer (terthiophene) as the starting material, polymerization is achieved with Fe(III) tosylate. The films are characterized by their Raman and absorption spectra, in addition to differential scanning calorimetry (DSC), optical microscopy, electrochemical impedance spectroscopy (EIS) and four-point probe surface conductivity measurements. From the spectroscopy studies, increased conjugation length of the polymer chains with decreasing temperature or vapour phase polymerization is evident. More surprisingly, DSC results indicate the order of the polymer chains is dramatically enhanced by vapour phase polymerization and the D.C. conductivity is an order of magnitude higher for VPP compared with traditional CP films. Additionally, the optical micrographs reveal a significantly different morphology than the films cast from solution.
Keywords: Poly(thiophene); Vapour phase polymerization; Raman spectroscopy;
Spacer-modified crosslinked copolymer beads for the solid phase synthesis of an amide by Kazumi Nagata; Tomomi Fukunaga; Shota Kato; Akinori Jyo (1127-1131).
The goal of this research was to synthesize an amide using the reaction of a polymer-supported active ester with a primary amine. A new type of the polymer support for an active ester was prepared from poly(ω-bromobutylstyrene-co-divinylbenzene) beads (1). Bromine atoms in 1 were replaced by mercapto groups upon treatment with thiourea and subsequent alkaline hydrolysis. Following this, N-hydroxymaleimide was reacted with the polymer (3). This reaction introduced N-hydroxysuccinimide moieties into the polymer beads via Michael addition, yielding a resin (4). Resin 4 was reacted with a model carboxylic acid in the presence of a water-soluble esterification reagent (WSC). This yielded resin (5), which contained polymer-bound active ester groups. Reaction of 5 with a primary amine gave the objective amide. Resulting amides had a higher purity than those prepared by solid phase synthesis using the corresponding polymer support, which was derived with poly(chloromethylstyrene-co-divinylbenzene) beads and a traditional liquid phase synthesis. Resin 5, after use in the amide synthesis, was regenerated into the active ester form for the repeated use.
Keywords: Reactive resin; Solid phase synthesis; Active ester; Crosslinked poly(ω-bromobutylstyrene); Amide synthesis;
Poly(p-maleimidostyrene) coated cross-linked polystyrene beads as novel ultrasonic irradiation resistant enzyme immobilization materials−Applications for biosensors and bioreactors by Tokio Hagiwara; Hiroshi Hirata; Shunichi Uchiyama (1132-1136).
Poly(p-maleimidostyrene) (PMS) was coated on cross-linked polystyrene(CLPS) beads. Enzymes (i.e., urease and fumarase) were stably immobilized on the beads via simple immersion into an enzyme solution for 30 min. Characterizations of PMS-coated on CLPS beads and evaluations of the enzymatic activity of bead-immobilized enzymes were conducted with confocal laser microscopy, electrochemical analysis, and spectrophotometry. Immobilized urease and fumarase demonstrated satisfactory enzyme activities. The K m of immobilized urease was estimated using electrochemical measurements and was found to be 2.2 × 10−3 M at 20 °C. PMS coating and immobilized enzymes both did not detach from the CLPS bead surface, even after ultrasonic irradiation. A biosensor using urease-immobilized PMS-coated CLPS beads showed good performance as a urea sensor. Furthermore, fumarase-immobilized PMS-coated beads may be promising materials for bioreactors producing (S)-(−)-malic acid.
Keywords: Poly(maleimidostyrene); Maleimide; Polystyrene beads; Enzyme immobilization material; Biosensor; Bioreactor;
Synthesis and photophysical behaviors of a blue fluorescent copolymer as chemosensor for protons and Ni2+ ion in aqueous solution by Baoyan Wang; Yulin Hu; Zhixing Su (1137-1143).
An acrylic monomer bearing couamrin moiety, 7-hydroxy-4-methyl-8-(4′-acryloylpiperazin-1′-yl) methylcoumarin (Ac-HMPC) was synthesized from 7-hydroxy-4-methyl-8-(4′-piperazin-1′-yl)methyl coumarin (HMPC) and acryloyl chloride (Ac) in the presence of triethylamine in dry dichloromethane (CH2Cl2) under 0 °C. The synthesized Ac-HMPC was identified by FTIR, MS and 1H NMR spectra, respectively. Then it was copolymerized with acrylamide (AM) using AIBN as initiator in THF under 70 °C. The main photophysical properties of the fluorescent copolymer (poly(Ac-HMPC-co-AM)) were determined viewing its sensor for protons and metal cations. The fluorescent polymer displayed “on–off” switching in its fluorescence intensity over a wide pH scale. In addition, it was found the fluorescence enhancement of poly(Ac-HMPC-co-AM) in the presence of Ni2+ ion. The results suggest that copolymer may offer potential as a reusable polymer for sensor protons and Ni2+ ion in aqueous solution.
Keywords: Coumarin; Blue fluorescent polymer; Photoinduced electron transfer; pH sensor; Metal cations;
Luminescent nanocomposites containing CdS nanoparticles dispersed into vinyl alcohol based polymers by Andrea Pucci; Massimiliano Boccia; Fernando Galembeck; Carlos Alberto de Paula Leite; Nicola Tirelli; Giacomo Ruggeri (1144-1151).
Size-controlled cadmium sulphide nanoparticles (CdS) stabilized by mercaptoethanol layers were prepared in solution and successively dispersed into different poly(vinyl alcohol)-based polymer matrices. The absorption and the emission features of the CdS nanocomposites were found to differ from those of colloidals dispersions and to be mainly affected by the particle (loose) aggregation in phase-separated, particle-rich regions of the materials. It was also found that the optical behaviour of the nanocomposites can be modulated through uniaxial orientation, which is presumed to partially destroy the aggregations.
Keywords: Cadmium sulphide nanoparticles; Polymer nanocomposites; Luminescence; (nano-)dispersion; Optical responsiveness;
Electrochemical impedance study of iron electrodes covered by polypyrrole films electrosynthesized in the presence of AOT by I.L. Lehr; S.B. Saidman (1152-1158).
The electrosynthesis of polypyrrole (PPy) onto iron electrodes in the presence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) solutions is characterized by the formation of a gelatinous material in parallel to the growth of the polymer. The electrochemical behaviour of this system under different experimental conditions was investigated using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. The study was focused in understanding the effects of various parameters, such as nature of the electrolyte and film thickness, on the dissolution process of iron. The response at low frequencies is related with the activity of the substrate. It was found that the electrode impedance for thick films is governed by diffusion of iron ions across the polymer and gel-like layers. Mass transfer contribution is prominent at the early stages of corrosion in chloride solution.
Keywords: Iron; AOT; Electrodeposited polypyrrole; Electrochemical impedance spectroscopy;
Immobilization of Cyphos IL-101 in biopolymer capsules for the synthesis of Pd sorbents by Thierry Vincent; Aurely Parodi; Eric Guibal (1159-1169).
Cyphos® IL 101, a tetraalkyl-phosphonium chloride salt, (ionic liquid, IL) was immobilized in capsules prepared by ionotropic gelation in calcium chloride solutions. These resins were tested for Pd recovery from HCl solutions. The sorption performance is slightly controlled by the concentration of HCl, in the range 0–2 M, with maximum sorption capacities close to 130–145 mg Pd g−1 resin (i.e. 1.2–1.4 mmol Pd g−1 resin or 0.96–1.07 mmol Pd mmol−1 Cyphos IL-101). Palladium, essentially present in the form PdCl 4 2 - is probably bound to the resin through anion exchange with protonated phosphonium groups (ion pair formation). Decreasing the amount of IL immobilized in the resin improves the rational use of the IL (higher molar ratio Pd/IL). The presence of other anions, for example nitrate, or other chloro-metal complexes, ZnCl 4 2 - decreases Pd binding, while other metals that do not form anionic complexes under the selected experimental conditions (for example Cu or Ni) do not interfere with Pd uptake. The pseudo-second-order rate equation was successfully used to model the kinetic profiles. Kinetics are mainly controlled by intraparticle diffusion resistance (low effect of agitation speed on the kinetic profiles). Crank’s equation was used to model intraparticle diffusion, giving intraparticle diffusivities close to 0.7–1.5 × 10−12 m2 min−1 for dry material and up to 5 × 10−12 m2 min−1 for wet resin. Drying the resin has a significant impact on mass transfer: uptake kinetics are improved by using raw resins. Desorption of the metal loaded resins can be performed using thiourea (in 0.1 M HCl solution) or HNO3 (5 M). The recycling and re-use of the resin was successfully demonstrated over three cycles; at the third desorption step a partial degradation of the resin was observed.
Keywords: Cyphos® IL 101; Palladium; Alginate; Gelatin; Sorption; Diffusion; Ion exchange; Desorption;
Effect of functionalized montmorillonite addition on the thermal properties and ionic conductivity of PVDF–PEG polymer electrolyte by Yun-Pu Wang; Xiang-Hu Gao; Rong-Min Wang; Han-Gong Liu; Chao Yang; Yu-Bing Xiong (1170-1177).
Composite microporous polymer electrolyte membranes comprising poly(vinylidene fluoride), PVDF, poly(ethylene glycol), PEG, and 1-ethyl-3-methylimidazolium tetrafluoroborate functionalized montmorillonite (EMIm-MMT) were prepared by a phase inversion method. The EMIm-MMT was subjected to FTIR, WXRD, TGA and element analysis in order to better understand the intercalation of imidazolium cations in sodium montmorillonite (Na-MMT) through exchange with intermellar sodium ions and improved thermal stability compared to organic-montmorillonite (O-MMT). The studies of porosity, weight uptake, and ionic conductivity of composite microporous membrane were performed as a function of EMIm-MMT content. The addition of EMIm-MMT can greatly enhance the thermal stability of the polymer electrolyte membrane. The maximum conductivity at 25 °C was found to be 7.77 mS cm−1 for PVDF–PEG/6wt% EMIm-MMT.
Keywords: Montmorillonite; Polymer electrolyte; Thermal stability; PVDF; PEG;
Reactive polyelectrolyte multilayers onto silica particles by Frank Simon; Ecaterina Stela Dragan; Florin Bucatariu (1178-1184).
The two polyelectrolytes poly(vinylformamide-co-vinylamine) [P(VFA-co-VAm)] and poly(acrylic acid) (PAA) have been alternately adsorbed from aqueous solution onto silica particles with sizes in the range 15–40 μm, and a mean pore radius of 60 Å. The growth of the alternately adsorbed P(VFA-co-VAm)/PAA film has been evidenced by the zeta-potential-pH profiles as a function of the last layer adsorbed. After the multilayer formation, when P(VFA-co-VAm) was the last layer adsorbed, the hybrid materials were annealed at 120 °C to stabilize the polymer layers by a heat-induced reaction forming amide groups. IR spectra of the hybrid material, before and after thermal treatment, showed the amide linkages formation. The cross-linked hybrid materials were subsequently functionalized with S-benzyl-l-cysteine. X-ray photoelectron spectroscopy (XPS) was employed to obtain information about the amount of the amino acid S-benzyl-l-cysteine which was grafted on the free amino groups on the hybrid particle surfaces.
Keywords: Silica; Adsorption; S-benzyl-l-cysteine; Electrokinetic measurements; X-ray photoelectron spectroscopy;