Electrochemically Obtained Insulating and Conducting Polymers and Composites of Acrylonitrile

Electrochemically obtained polyacrylonitrile and a commercial polyacrylonitrile were heat treated to improve their conductivities. The parameters chosen for heat treatment conditions were the temperature, treatment medium (vacuum or air) and, doping agent. The conductivity of all heat treated polymers was measured. The characterization of the heat treated polymers was made by IR analysis. The composite films of polyacrylonitrile with polypyyrole and polythiophene were electrochemically prepared at different compositions. The change in the conductivity of composites was analyzed as a function of the percent composition of the insulating component. IR, DSC, TGA and SEM analyses were used to characterize the polymer composites

A CONDUCTING COMPOSITE OF POLYPYRROLE .1. SYNTHESIS AND CHARACTERIZATION

A conducting composite of polypyrrole was prepared via electrochemical methods. A polyamide was used as the insulating matrix polymer. The characterization of the composite was done by FT-IR, SEM, TGA, DSC and pyrolysis studies. Conductivity and solubility studies together with spectroscopic methods reveal that H bonding exists between the two polymers and a possible grafting to a certain extent

Immobilization of cholesterol oxidase in a conducting copolymer of thiophene-3-yl acetic acid cholesteryl ester with pyrrole

Cholesterol oxidase has been immobilized in conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester with pyrrole (CM/PPy) and polypyrrole (PPy) via electropolymerization. p-Toluene sulphonic acid was used as the supporting electrolyte. Kinetic parameters (V-max and K-m) and operational stability of enzyme electrodes were investigated. Surface morphology of the films was examined by scanning electron microscope

Highly conjugated visible and near-infrared light photoinitiating systems for radical and cationic polymerizations

In this communication, we report highly conjugated thiophenes having [1,2,5]-thiadiazolo and [1,2,5]-selenadiazolo [3,4-f]-benzo [1,2,3] triazole in conjunction with diphenyliodonium hexafluorophosphate salt(DPI) as new visible and near-infrared light (NIR) photoinitiator systems for free radical (FRP) and cationicpolymerizations (CP). The postulated mechanism is based on the electron transfer reactions between the excitedconjugated molecule and DPI ions. The radicals and Bronsted acid formed this way initiate FRP and CP ofappropriate monomers such as methylacrylate (MA), methyl methacrylate (MMA), triethylene glycol dimethacrylate(TEGDMA) and cyclohexene oxide (CHO), isobutyl vinylether (IBVE) respectively. The possibility of insitu hybrid polymerization is also demonstrated using bifunctional monomer glycidyl methacrylate (GMA)

Altering Electronic and Optical Properties of Novel Benzothiadiazole Comprising Homopolymers via π Bridges

Four novel benzo[c][1,2,5]thiadiazole comprising monomers namely 5-fluoro-6-((2-octyldodecyl)oxy)-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole (TBTT), 5-fluoro-4,7-bis(4-hexylthiophen-2-yl)-6-((2-octyldodecyl)oxy)benzo[c][1,2,5]thiadiazole (HTBTHT),5-fluoro-4,7-di(furan-2-yl)-6-((2-octyldodecyl)oxy)benzo- [c][1,2,5]thiadiazole (FBTF), and 5-fluoro-6-((2-octyldodecyl)oxy)-4,7-bis(thieno[3,2-b]thiophen-2-yl)benzo[c][1,2,5]thiadiazole (TTBTTT) were designed, and synthesized successfully via Stille polycondensationreaction. The structural characterizations of the monomers were performed by 1H and 13C NMR spectroscopy and HighResolution Mass Spectroscopy (HRMS). The monomers were then electropolymerized in a three electrode cell system via cyclicvoltammetry. The electrochemical, and spectroelectrochemical characterization of the polymers were reported in detail. Besides,theoretical calculations were performed to elucidate observed experimental properties. According to the cyclic voltammogram of thepolymers, HOMO and LUMO energy levels were calculated as −5.68 eV/−3.91 eV, −5.71 eV/−3.72 eV, −5.61 eV/−4.04 eV, and−5.51 eV/−3.71 eV and the electronic band gaps were 1.77 eV, 1.99 eV, 1.57 eV, and 1.80 eV for PTBTT, PHTBTHT, PFBTF, andPTTBTTT, respectively

Organic bulk heterojunction solar cells based on benzodithiophene and benzothiadiazole containing conjugated polymers

Organic photovoltaics (OPVs) or so-called organic solar cells particularly hold promise for manufacturing solar energy due to their advantages in low cost and production processes. In order to understand and improve the performance of OPVs, intense efforts have been dedicated around the world [1]. In particular, conjugated polymers are attractive for OPVs due to the π-conjugated systems in the polymer backbone which generates and transport the charge carriers [2]. Therefore, the design and synthesis of novel conjugated organic polymers play important role to obtain higher photovoltaic properties and improve the power conversion efficiencies (PCEs) of the OPVs. For this purpose, benzodithiophene and benzothiadiazole containing monomers were independently synthesized, then polymerized via Stille cross-coupling reaction to obtain P1 and P2 polymers. Oxidation and reduction behavior of the polymers were studied by cyclic voltammetry. Measurements indicated that the highest occupied molecular orbital (HOMO) levels were -5.25 eV for P1 and -5.38 eV for P2. The optical band gaps of P1 and P2 were calculated via UV-VIS-NIR spectroscopy as 1.54 eV and 1.64 eV, respectively. Bulk heterojunction solar cells were constructed with these polymers as the donor moieties together with PC71BM as the acceptor in the active layer. The current/voltage measurements showed that the highest PCEs of these photovoltaic devices were recorded as 2.52% for P1: PC71BM (1:4, w/w) in 2% DIO and 1.67% for P2: PC71BM (1:3, w/w) in 3% DIO solution

Benzodithiophene and selenophene bearing polymer for inverted organic solar cell applications

Inverted organic solar cells have advantages over conventional organic solar cells. Most important advantage is the improved stability of inverted solar cells. In this study, benzodithiophene, quinoxaline and selenophene bearing conjugated polymer was used as donor material in inverted solar cell applications. Device performances were investigated with the device configuration of ITO/ ZnO/ polymer:PC71BM/ MoO3/ Ag. In order to improve device performance, polymer PCBM ratio, active layer thickness, annealing time and temperature optimizations were carried out. Active layer morphologies were investigated by TEM and AFM analyses. Best performance device showed power conversion efficiency of 2.57 % with VOC of 0.67 V, JSC of 7.68 mAcm-2 and FF of 50 %

Synthesis of selenophene substituted benzodithiophene and fluorinated benzothiadiazole based conjugated polymers for organic solar cell applications

© 2021A series of alternating conjugated copolymers which contain selenophene modified benzodithiophene and fluorine bearing benzothiadiazole have been synthesized via Stille polycondensation reaction to investigate the effect of the number of fluorine atoms substituted to the benzothiadiazole. Three different polymers, PBDTSe-BT, PBDTSe-FBT and PBDTSe-FFBT, were reported and their electrochemical, spectroelectrochemical, and photovoltaic behaviors were examined. Density functional theory calculations were performed on model tetramer structures to shed light on how substituting the fluorine atom to the acceptor building block affects the structural, electronic and optical properties of the polymers. The results of computational studies were compared with experimental studies. The structure adjustment accomplished by fluorine substitution on the benzothiadiazole moiety reveals an influence on the electronic structure of polymers with a more negative HOMO energy level. A high VOC for the resulting photovoltaic device was examined for PBDTSe-FFBT. Difluorinated polymer PBDTSe-FFBT:PC71BM organic solar cell exhibited the highest photovoltaic performance of 2.63% with JSC of 7.24 mA cm-2, VOC of 0.72 V and FF of 50.6%. PBDTSe-BT:PC71BM revealed the best PCE as 2.39%, and the device reached the highest efficiency up to 1.68% for PBDTSe-FBT:PC71BM