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1.
Thiophene functionalized polystyrene samples (TFPS) were synthesized by atom transfer radical polymerization (ATRP) of styrene, followed by Suzuki coupling with 3‐thiophene (Th) boronic acid. Conducting graft polymer of TFPS with thiophene was achieved at 1.5 V in tetrabutylammonium tetrafluoroborate/dichloromethane (TBAFB/DM) by electrochemical methods. Spectroelectrochemical analysis of the resulting copolymers [P(TFPS‐co‐Th)] reflected electronic transitions at 449, 721 and 880 nm, revealing π ? π* transition, polaron and bipolaron band formation, respectively. We also successfully established the utilization of dual type complementary colored polymer electrochromic devices using P(TFPS‐co‐Th)/poly(3,4‐ethylenedioxythiophene (PEDOT) in sandwich configuration. The switching ability, stability and optical memory of the electrochromic device were investigated by UV–visible spectrophotometry and cyclic voltammetry. Device switches between brown and blue color with a switching time of 1.3 s were prepared with optical contrast (%ΔT) of 25 %. Copyright © 2005 Society of Chemical Industry  相似文献   

2.
Summary A random copolymer (CP) containing 3-methylthienyl methacrylate (MTM) and p-vinylbenzyloxy poly(ethyleneoxide) (PEO-VB) units was synthesized. Further graft copolymerization of CP with pyrrole (Py) and thiophene (Th) were achieved in H2O - sodium dodecyl sulfate (SDS), H2O - p-toluenesulphonic acid (PTSA) and acetonitrile (AN) - tetrabutylammonium tetrafluoroborate (TBAFB) solvent electrolyte couples via constant potential electrolyses. Characterization was performed by cyclic voltammetry (CV), nuclear magnetic resonance spectroscopy (NMR), and fourier transform infrared spectroscopy (FTIR). The morphologies of the films were examined by scanning electron microscopy (SEM). Conductivities of the samples were measured by using four-probe technique. Moreover, spectroelectrochemical and electrochromic properties of the copolymer obtained from thiophene were investigated by UV-Vis spectrometry and colorimetry.  相似文献   

3.
Polythiophene (PTh) films were prepared by the electrochemical polymerization of thiophene in acetonitrile solution with boron fluoride–ethyl ether (BFEE) as the electrolyte. The electropolymerization processes were investigated by cyclic voltammetry. The onset potential of the electropolymerization decreased dramatically with increasing BFEE proportion in the solution. The free‐standing PTh films obtained were characterized by Founier transform infrared spectroscopy, scanning electron microscopy, and X‐ray photoelectron microscopy. The influence of BFEE on the morphology and conductivity of the PTh films was also examined. The binary solvent solution consisted of acetonitrile (10 vol %) and BFEE (90 vol %), which turned out to be the optimal electrosythesis system, in which a current density of 1 mA/cm2 and a monomer concentration of 50 mM were the optimal conditions for electropolymerization. The PTh film obtained under the optimized conditions had a high tensile strength of 60 MPa and a high conductivity of 153 S/cm. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 940–946, 2003  相似文献   

4.
Yelda Coskun 《Polymer》2004,45(15):4989-4995
Terepthalic acid bis-(2-thiophen-3-yl-ethyl)ester (TATE) was synthesized through the reaction of 2-thiophen-3-yl-ethanol and terepthaloyl chloride. Homopolymer of TATE was synthesized via potentiostatic and potentiodynamic methods by using tetrabutylammonium tetrafluoroborate (TBAFB) as the supporting electrolyte in dichloromethane/borontrifluoride ethylether solvent mixture (DM/BFEE) (8:2, v/v). Copolymerisation of TATE with thiophene was achieved in DM/BFEE solvent mixture (8:2, v/v) by using TBAFB as the supporting electrolyte in the presence of thiophene. The chemical structure of monomer is characterised via NMR and FTIR. Both homopolymer (PTATE) and copolymer P(TATE-co-Th) were characterised by various techniques including cyclic voltammetry, FTIR, scanning electron microscopy and UV-VIS spectroscopy. Conductivities of samples were measured by four probe technique. Optoelectrochemical analysis indicates that the homopolymer and copolymer have an electronic band gap, measured as the onset of the π-to-π* transition, as 2.17 and 2.00 eV, respectively.  相似文献   

5.
This paper reports polythiophene/cobalt (II,III) oxide (PTh/Co3O4) nanocomposites synthesized via in situ polymerization of thiophene in the presence of Co3O4 at various molar concentrations. Samples were characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), Energy‐dispersive X‐ray (EDX) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and atomic force microscopy (AFM). The alternating current (ac) conductivity of the samples was studied depending on the temperature. XRD analyses indicated that the filling process decreased the π ? π stacking distance of PT chains. The most significant shift was observed in the C‐S band of PTh depending on the filling process. Thermal stability of the PTh increased with increasing concentration of Co3O4. Filling process reduced the surface roughness of PTh. The ac conductivity analyses indicated that charge transport mechanism of the samples was consistent with corraleted barrier hopping (CBH) model. The conductivity of PTh increased about 18 times for maximum filling level depending on temperature and frequency. The thermal stability and controllable ac conductivity properties of PTh/Co3O4 nanocomposites showed that they can be used in the production of micro/nano‐sized electronic circuit elements with lower cost. POLYM. ENG. SCI., 57:1168–1178, 2017. © 2017 Society of Plastics Engineers  相似文献   

6.
A conductive polyaniline (PAn)–polythiophene (PTh)/poly(ethylene terephthalate) (PET) composite fiber was prepared by polymerization of aniline and thiophene in the presence of PET fibers in an organic medium with FeCl3. The effects of polymerization conditions, such as polymerization medium, mol ratios of aniline/thiophene and FeCl3/aniline‐thiophene as well as polymerization temperature and time, were investigated on PAn–PTh content (%) and surface resistivity of the composite. The composite with the lowest surface resistivity (1.30 MΩ/cm2) was obtained by polymerization of aniline and thiophene (1/3 mol ratio) in acetonitrile/chloroform (1/5 volume ratio) at 20°C. The surface resistivity of the PAn–PTh/PET composite containing 4.8% PAn–PTh was increased from 1.9 MΩ/cm2 to 270 MΩ/cm2 at pH 11. The washing durability of the composites was determined with domestic and commercial laundering processes by monitoring the surface resistivity and morphology. The composite was also characterized with FTIR, TGA, elemental analysis, optic microscope and SEM techniques. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41979.  相似文献   

7.
The electropolymerization of thiophene in the presence of 1‐(2‐pyrrolyl)‐2‐(2‐thienyl) ethylene (PTE) was investigated. PTE was synthesized via Wittig reaction and by the addition of catalytic amount of PTE during the electropolymerization of thiophene, the conditions of electropolymerization of thiophene were modified. The cyclic votammograms of polythiophenes (PThs) in different conditions were obtained. The analysis of cyclic votammograms of PThs shows a considerable increase in the electroactivity and redoxability when the electropolymerization of thiophene in the presence of catalytic amount of PTE was performed. The presence of PTE during electropolymerization of thiophene leads to an increase in the rate of polymerization too. The cyclic voltammetry (CV) measurement of electron transfer ferro/ferricyanide redox system on different modified glassy carbon (GC) electrode has shown that the rate of charge transfer for PTh in the presence of PTE increased in comparison to pure PTh. The conductivity of obtained polymers was determined by electrochemical impedance spectroscopy (EIS) technique in 3.5% (w/v) NaCl solutions. The Zview(II) software was applied to the EIS to estimate the parameters of the proposed equivalent circuit, based on a physical model for the electrochemical behavior of coatings on GC. The Rct value obtained for PTh is 7667 Ω cm2. This value decreases in the presence of PTE to 4437 Ω cm2. Thus, the new film has more conductivity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

8.
The synthesis was performed by the electropolymerization of thiophene on a poly(dimethylsiloxane) (PDMS)‐coated platinum electrode at 2.2 V with tetrabutylammoniumtetrafloroborate (TBAFB) as a supporting electrolyte and with acetonitrile as a solvent. The characterization of the PDMS–polythiophene (Pth) composites was carried out with cyclic voltammetry, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis, and conductivity measurements. The observed conductivities of the PDMS composites were 2.2–5.2 S/cm. The conductivity of Pth did not change appreciably with the addition of up to 30% insulating PDMS, but its processability improved. FTIR, SEM, and DSC studies showed the existence of a strong interaction, rather than physical adhesion, between PDMS and Pth. Highly flexible and foldable PDMS–Pth composites were obtained. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2113–2119, 2003  相似文献   

9.
A new copolymer of N‐(4‐(3‐thienyl methylene)‐oxycarbonylphenyl)maleimide (MBThi) with thiophene [P(MBThi‐co‐Th)] was synthesized electrochemically in the presence of tetrabutylammonium tetrafluoroborate as the supporting electrolyte, in acetonitrile/borontrifluoride ethylether solvent mixture (80 : 20, v/v). Spectroelectrochemical analysis of the resulting copolymer reflected electronic transitions at 440, 730, and ~1000 nm, revealing π–π* transition, polaron, and bipolaron band formation, respectively. Switching ability was evaluated by a kinetic study via measuring the transmittance (%T) at the maximum contrast. Dual‐type polymer electrochromic devices (ECDs) based on P(MBThi‐co‐Th) and poly(ethylene dioxythiophene) (PEDOT) were constructed. Spectroelectrochemistry, switching ability, and stability of the devices were investigated by UV–vis spectroscopy and cyclic voltammetry. These devices exhibit low switching voltages (between 0.0 and +2.0 V) and short switching times with reasonable switching stability under atmospheric conditions. © 2006 Wiley Periodicals, Inc. J Appl PolymSci 102: 4500–4505, 2006  相似文献   

10.
We report a new method for the synthesis of polythiophene (PTh)/graphene oxide (GO) nanocomposites by interfacial polymerization. Polymerization occurred at the interface of two immiscible solvents, i.e. n‐hexane containing thiophene and nitromethane containing GO and an initiator. Characterizations were done using Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, and electrochemical and electrical conductivity measurements. Spectroscopic analyses showed successful incorporation of GO in the PTh matrix. Morphological analysis revealed good dispersion of GO sheets in the polymer matrix. The PTh/GO composites showed marked improvements in thermal stability and electrical conductivity (2.7 × 10?4 S cm?1) compared to pure PTh. The composites exhibited excellent electrochemical reversibility compared to pure PTh at a scan rate of 0.1 V s?1. The composites were stable even up to 100 electrochemical cycles, indicating good cycle performance. The specific capacitance of the composites was calculated using cyclic voltammetry and was found to be 99 F g?1. © 2014 Society of Chemical Industry  相似文献   

11.
Graft copolymers of poly(vinyl alcohol) with thiophene side‐groups and pyrrole were synthesized by electrochemical polymerization methods. Poly(vinyl alcohol) with thiophene side‐groups (PVATh) was obtained from the reaction between poly(vinyl alcohol) (PVA) and thiophene‐3‐acetic acid. The syntheses of copolymers of PVATh and pyrrole were achieved electrochemically by using three different supporting electrolytes, p‐toluene sulfonic acid (PTSA), sodium dodecyl sulfate (SDS) and tetrabutylammonium tetrafluoroborate (TBAFB). Characterization of PVATh and graft copolymers was performed by a combination of techniques including cyclic voltammetry, scanning electron microscopy, thermal gravimetry, differential scanning calorimetry, size‐exclusion chromatography, 1H NMR and FT‐IR. The conductivities were measured by the four‐probe technique. Copyright © 2004 Society of Chemical Industry  相似文献   

12.
A bifunctional polytetrahydrofuran (PTHF) macromonomer was synthesized by termination of the living polymerization of tetrahydrofuran (THF) initiated by triflic anhydride and the subsequent termination by sodium methacrylate. The PTHF macromonomer thus prepared was polymerized and copolymerized with methyl methacrylate (MMA) by free‐radical polymerization to yield a network and a segmented network of PTHF, both being homogeneous, respectively. These PTHF and PTHF–PMMA gels were used for swelling experiments in chloroform and chloroform vapor. Drying processes were monitored after removing the gels from the solvent and solvent vapor. Photon transmission from PTHF and PTHF–PMMA gels was monitored during swelling and drying processes using a UV‐visible (UVV) spectrophotometer. Transmitted light intensities, Itr, from these gels increased when they were immersed in chloroform and/or subjected to its vapor. The increase in Itr was attributed to the homogeneous lattice structure of PTHF and PTHF–PMMA gels which appeared during swelling. The increase in Itr was modeled using the Li–Tanaka equation from which time constants, τ1, and cooperative diffusion coefficients, DC, were determined. A decrease in Itr after removing choloform and/or its vapor from the cell was observed and attributed to the decrease in homogeneity of lattice structures during drying of the corresponding gels. Time constants, τ2, for the drying processes were also determined. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 632–640, 2003  相似文献   

13.
The performance of pyrrole and thiophene polymer electrodes in lithium cells has been examined in the lithium perchlorate–propylene carbonate electrolyte by cyclic voltammetry. Polypyrrole films were synthesized in 'wet' and 'dry' conditions; pyrrole and thiophene copolymers were prepared at different potentials and bilayers were prepared by sequential deposition of polythiophene (PTh) and polypyrrole (PPy) films. The polymers were cycled between 2.0V and 4.0V in the lithium cells. The effects of disconnecting the electrodes from the cell on the behaviour of the polymers regarding doping and coulombic efficiency were also studied. The cycling performance of the 'wet' PPy is better than 'dry' PPy, bilayer PTh/PPy and copolymers. No mixed behaviour was observed for a bilayer where the inner layer was polythiophene and the outer layer was polypyrrol with a thickness PPy/Pth ratio equal to ten. The copolymer prepared at 3.9V vs Li/Li+ showed the higher energy capacity in Whkg–1 calculated from the anodic charge.  相似文献   

14.
A new and promising method for the diversification of microbial polyesters based on chemical modifications is introduced. Poly(3‐hydroxy alkanoate)‐g‐(poly(tetrahydrofuran)‐b‐poly(methyl methacrylate)) (PHA‐g‐(PTHF‐b‐PMMA)) multigraft copolymers were synthesized by the combination of cationic and free radical polymerization. PHA‐g‐PTHF graft copolymer was obtained by the cationic polymerization of THF initiated by the carbonium cations generated from the chlorinated PHAs, poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV), and poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBHx) in the presence of AgSbF6. Therefore, PHA‐g‐PTHF graft copolymers with hydroxyl ends were produced. In the presence of Ce+4 salt, these hydroxyl ends of the graft copolymer can initiate the redox polymerization of MMA to obtain PHA‐g‐(PTHF‐b‐PMMA) multigraft copolymer. Polymers obtained were purified by fractional precipitation. In this manner, their γ‐values (volume ratio of nonsolvent to the solvent) were also determined. Their molecular weights were determined by GPC technique. The structures were elucidated using 1H‐NMR and FTIR spectroscopy. Thermal analyses of the products were carried out using differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

15.
Two novel π‐conjugated monomers, 6‐(4‐octyloxyphenyl)‐4,8‐bis(thiophene‐2‐yl)‐3H‐[d] imidazole[1,2,5] benzothiadiazole (M3) and 4‐(4‐octyloxyphenyl)‐2,6‐bis(thiophene‐2‐yl)‐3H‐[d] imidazole‐acenaphtho[1,2‐b]quinoxaline (M4), were synthesized. The monomer M4 contains a thiophene electron‐donating unit and electron withdrawing unit in which quinoxaline and benzimidazole integrated in one benzene ring. Electrochemical polymerization of the monomers was carried out in acetonitrile/dichloromethane solvent mixture containing tetra‐n‐butylammonium hexafluorophosphate and electrochromic properties of polymers (P3 and P4) are described in this article. Furthermore, the effects of structural difference on electrochemical redox behavior and spectroelectrochemical properties of the two resulting polymers were examined. The results showed that an anodic wave at +0.48 V versus Ag wire pseudo‐reference electrode corresponding to the monomer M4 oxidation was observed, while one anodic wave at +0.70 V was observed in oxidation of M3 as it contains stronger electron withdrawing thiadiazole structure. The UV‐vis‐Near‐infrared (Near‐infrared spectroscopy) (NIR) spectra analysis revealed that the two polymers have one absorbance band centered at 603 nm. The band gaps, defined as the onset of the absorption band at 603 nm of these polymers, were determined as 1.60 eV for P3 and as 1.55 eV for P4. The electrochromic results showed that P3 revealed about 20% optical contrast at 980 nm and the P4 has 30% optical contrast at 806 nm with low response time (1 s for each polymer). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40861.  相似文献   

16.
A new strategy for graft copolymerization of thiophene onto a polystyrene (PSt) backbone by a multi‐step process is suggested and the effects of an organoclay on the final properties of the graft copolymer sample are described. For this purpose, first poly(styrene‐co‐4‐chloromethyl styrene) [P(St‐co‐CMSt)] was synthesized via nitroxide‐mediated polymerization. Afterwards, the chlorine groups of P(St‐co‐CMSt) were converted to thiophene groups using the Kumada cross‐coupling reaction and thiophene‐functionalized PSt multicenter macromonomer (ThPStM) was synthesized. The graft copolymerization of thiophene monomers onto PSt was initiated by oxidized thiophene groups in the PSt chains after addition of ferric chloride (FeCl3), an oxidative catalyst for polythiophene synthesis, and FeCl3‐doped polythiophene was chemically grafted onto PSt chains via oxidation polymerization. The graft copolymer obtained was characterized by 1H NMR and Fourier transform infrared spectroscopy, and its electroactivity behavior was verified under cyclic voltammetric conditions. Finally, PSt‐g‐PTh/montmorillonite nanocomposite was prepared by a solution intercalation method. The level of dispersion of organoclay and the microstructure of the resulting nanocomposite were probed by means of XRD and transmission electron microscopy. It was found that the addition of only a small amount of organoclay (5 wt%) was enough to improve the thermal stabilities of the nanocomposite.© 2013 Society of Chemical Industry  相似文献   

17.
Electrochemical copolymerizations of 2,3‐di(2‐thienyl)quinoxaline (M1), 6‐methyl‐2,3‐di(2‐thienyl)quinoxaline (M2), and 2,3‐di(2‐thienyl)quinoxaline‐6‐yl)(phenyl)methanone (M3) with 3,4‐ethylenedioxy thiophene (EDOT) were carried out in CH3CN/TBABF4 (0.1M) solvent‐electrolyte couple via potentiodynamic electrolysis. The obtained copolymers were characterized by cyclic voltammetry (CV), Fourier transform‐infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetry analyses (TGA). The conductivity measurements of copolymers and PEDOT were performed by the four‐probe technique. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

18.
In this study, we report the effect of the DMPA/PTHF molar ratio on dispersion properties of the MDI‐based hydrophilic polyurethane dispersions. In addition, the effect of the DMPA/PTHF molar ratio on the crystallinity and thermal properties of the polyurethane films prepared from dispersions are also discussed. The variation in stability was studied using a particle size analyzer. DSC and XRD analyses were used to study variations in crystallinity of films with the change of DMPA/PTHF molar ratio. FT‐IR spectra were used to monitor the formation of hydrogen bonds through urethane linkages to produce hard‐segment crystalline areas. The zeta potential increased with the increase of DMPA/PTHF molar ratio (hard‐segment content), while particle size of polyurethane particles decreased. Hence, the stability of dispersions was increased with DMPA/PTHF molar ratio due to the increase of hydrophilicity in polymer chain. Crystallinity of the films was increased with DMPA/PTHF molar ratio due to the increase of interchain interactions through Coulombic interactions and hydrogen bonding. Consequently, crystalline melting temperature was increased with the increase of DMPA/PTHF molar ratio. However, molten films formed crystalline soft segments instead of crystalline hard segments during slow cooling. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44475.  相似文献   

19.
A polymer derived from poly-9-bis[4-(thiophen-3,4-yloxy)biphenyl)]-9H-carbazole containing a carbazole and thiophene group, abbreviated as B2, was synthesized via the oxidation method by using FeCl3 as an oxidant. Additionally, the electrochemical polymer of B2 was synthesized and coated onto an ITO–glass surface via electrochemical oxidative polymerization. The electrochemical synthesis of the polymer was performed in 0.05 M AN/LiClO4 solvent/electrolyte solution containing 0.1 M concentration of B2 between +0.3 and +1.4 V potentials. The compounds were characterized by FT-IR, NMR, and elemental analysis techniques. The spectroelectrochemical and electrochromic properties of this polymer were also investigated in 0.05 M AN/LiClO4 solvent/electrolyte solution for 200 s and at a constant potential of +1.4 V. Switching ability of this polymer was measured as the percent transmittance (?T%) at its changing point of maximum contrast. Additionally, the scan rate study was performed at different scan rates: 400, 300, 200, 100, 50, 20 mV/s. According to the electrochromic measurements, the synthesized polymer had a light blue color when it was oxidized, and when it was reduced, it had a transparent color. As a result, the synthesized polymer P(B2) can be used to produce new polymeric electrochromic devices, and it can be considered a good candidate for applications of electrochromic devices (ECDs) because of its short response time of 3.5 s.  相似文献   

20.
Modified palygorskite‐polythiophene (MPA‐PTh) composites were prepared by chemical oxidative polymerization of palygorskite (PA) nucleartor with thiophene (Th) after the surface modification with γ‐(2,3‐epoxypropoxy) propytrimethoxysilane (KH‐560). The MPA‐PTh composites were doped in iodine vapor to create the porous palygorskite‐polythiophene (PMPA‐PTh) conductive composites. Fourier transform infrared spectra (FTIR), X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms using the Brunauer–Emmett–Teller method (BET) and electrochemical impedance spectrum (EIS) techniques were applied to characterize the modified PA and the prepared composites. According to FTIR and XPS, the KH‐560 was bound to the PA surface and the iodine ion (I3? and I5?) entered the PTh molecular chains. XRD, SEM, TEM, BET, and EIS analysis confirmed that the doping of iodine not only transform the core–shell MPA‐PTh into the PMPA‐PTh but also improve the electrical conductivity of composites. The PMPA‐PTh composites were fabricated that yield a volume resistivity of ~2.44 × 102 Ω cm and a internal resistances of ~100 Ω, and their BET surface area, BJH (Barrett–Joiner–Halenda) average pore size and BJH cumulative pore volume were improved in comparison with those of the MPA‐PTh composites. SEM images showed that the PMPA‐PTh composites could form consecutive space network and the PMPA‐PTh composites acrylic coating films had advisable conductivity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

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