Copolymerization and homopolymerization of 7-methacryloyloxy coumarin (MAOC) and its copolymers with benzyl methacrylate (BMA), methyl methacrylate (MMA), ethyl methacrylate (EMA), and isobuthyl methacrylate (IBMA) were performed by the free radical polymerization method (FRP) at low conversions (<15%). The resulting polymers were characterized by FTIR, 1H NMR, GPC, DSC, and TGA. The monomer reactivity ratios of MAOC and BMA were computed using Kelen-Tüdös (K-T) and Fineman-Ross (F-R) methods and were found to be r1=0.45, r2=1.29; r1=0.46; r2=1.33, respectively (r1 is monomer reactivity ratio of MAOC). Blends of poly(MAOC) and poly(BMA) obtained via FRP method were prepared by casting films from dichloromethane solution and were characterized by DTA and TGA techniques. Dielectric measurements for MAOC homopolymer and its copolymers with EMA, MMA, and IBMA were carried out by means of an impedance analyzer as a function of temperature and frequence. Dielectric properties of polymer samples prepared in a plate form were measured at room temperature over the frequency range 0.1 kHz–2 MHz and given as compared with each other.
Electropolymerization of carbazole (Cz) by cyclic voltammetry (CV) onto carbon fiber microelectrodes (CFME) (diameter ~7 µm) in dichloromethane (CH 2 Cl 2 ) solution of 0.1 mol·dm -3 tetraethyl ammonium perchlorate (TEAP) results in the formation of polycarbazole (PCz) thin film coatings. CV results showed that these PCz thin films have reversible redox behavior in monomer-free electrolyte solution. The resulting thin polymer films were characterized using Fourier transform infrared attenuated total reflectance spectroscopy (FTIR-ATR) and atomic force microscopy (AFM). Results performed at optimum experimental conditions indicate that electrodes show a reversible and stable behavior over sixty eight days of testing for dopamine in 100 µmol·dm -3 buffer solution. A detection limit for PCz thin films as low as 0.1 µM (3S/N) was obtained for the polycarbazole (PCz) thin films formed using CV. Hence, this novel sensor can be considered as promising sensor for dopamine detection.
A series polymers of the poly(4-{[bis(2-hydroxyethyl)amino]methyl}-2-oxo-2H-chromen-7-yl-2-methylpropanoate), P(CIMMAOC)-DEA, were synthesized by modification of poly(4-(chloromethyl)-2-oxo-2H-chromen-7-yl-2-ethylpropanoate), P(CIM-MAOC), with diethanolamine (DEA). All polymers were structurally characterized by FTIR, 1 H NMR, UV-vis, and Fluorescence spectra. The electronic features of the polymer, such as lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energies and electrostatic potential (ESP), and the vibrational frequencies were computed by the Becke3-Lee-Yang-Parr (B3LYP) functional using 3-21G* basis set. Dielectric measurements for P(CIMMAOC) and P(CIMMAOC)-DEA were performed by means of an impedance analyzer as a function of frequency and temperature. It was found that the dielectric constant values decreased in the applied frequency range. The values of dielectric constant increased with a rise in concentrations of DEA in polymer for all temperatures. Dielectric constants of P(CIMMAOC) and P(CIMMAOC)-DEA (60%) were calculated as 3.93 and 12.29 at 1 kHz, respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.