Preparation Of Polyaniline Derivants Nano-Composites And Study On Their Properties

Conducting polymers have been studied extensively because of their potential applications in sensors, electrochromic devices, and electrochemical supercapacitors as well as active electrode materials. Polyaniline and its derivatives have been considered as promising materials in various applications due to their versatile properties, for example, good environmental stability, ease of processability, high conductivity, swift change in color with applied potential and a simple, and reversible acid/base doping/dedoping properties. Nanomaterials are now one of the hot points in chemistry field in recently years. With the widen and deepen of the research, the scientists are re-examing the traditional polymers with the hope to find novel properties and functions.In recent years, there has been increased interest in nanostructures of the conducting polymers, such as nanospheres, nanotubes, nanowires, and nanoparticles, mainly because they will have the advantages of both low-dimensional system and organic conductors. In addition, the multifunctionalized PANI nanostructures have also been synthesized by blending with inorganic electrical, optical, and magnetic nanoparticles to form composite nanostructures. In this paper, novel nanostructures of polyaniline were synthesized via self-assembly method. At the same, our research expanded to the nanocomposite of polyaniline and nanoparticles or carbon nanotubes with unique electric activities. Nanorods of DBSA-PANI were synthesized through an interfacial polymerization method. Controllable diameters of DBSA-PANI nanorods from 40 nm to 1μm could be obtained by tuning the molar ratio of aniline to APS. It was also found that the morphology, size of the nanostructures also depended on the concentration of DBSA aqueous solution as well as the reaction temperature. Lower concentration of DBSA and lower temperature will be helpful to the formation of rod-like nanostructures with a relative small diameter. UV-Vis and FTIR measurements confirmed that the main chain structure of these PANI products were identical to the emeraldine salt form of PANI. And a possible mechanism of the formation of the rod-like DBSA-PANI was proposed. In summary, DBSA-PANI nanorod materials could be synthesized well by a controllable interfacial polymerization with the proper conditions.A novel and simple method was used to prepare well-dispersed Fe3O4-poly (aniline-co-o- anthranilic acid) nanoparticles. The structure and morphology of the composite was characterized by FTIR, XRD and TEM, which indicated that the Fe3O4-poly (aniline-co- o-anthranilic acid) nanoparticles were about 20 nm and well-dispersed. Furthermore, it was proved that the obtained composite possesses the superparamagnetic behavior and excellent thermal stability.We have described the synthesis of POT/c-MWNT composites with improved electrical conductivity. The electrical conductivities at room temperature of 10 wt.% c-MWNTs containing POT/c-MWNTcomposite are about 20 times higher than that of POT without c-MWNTs. The morphology of POT/MWNT composites contains both the thinner fibrous phase and the larger block phase. It is presumed that c-MWNTs were used as a core in the formation of tubular shells of the fibrous POT/c-MWNT composites. FT-IR, XRD, UV–vis spectra are used to characterize the structure of POT/c-MWNT composites.The electrochemical properties of polyaniline and synthesized polyamide were investigated and discussed. In summary, from the analysis of the experimental data obtained from CV, EIS and theoretical calculations, conclusions could be drawn as following: (i) the appearance of three pairs of redox peaks in CV measurement of polyamide indicate a relatively more complicated redox process compared with conventional polyaniline. Moreover, through electrochemical calculation and analysis, an electric charge-transfer controlled process during redox of polyamide film on the surface of glassy-carbon electrode can be confirmed. (ii) Impedance spectra of synthesized polyamide and conventional polyaniline depict typical model of polymer film-coated metals in the asymmetric metal/film/electrolyte configuration. The difference in diameters of the semi-circle impedance arc indicates that polyamide film exhibits higher electronic conductivity and lower resistance than those of the conventional polyaniline. (iii) Through analysis of theoretical calculations, influences of molecular structures on the impedance of the polymers were discussed including system energy, skeleton conjugation and the Fermi energy of the bipolaron model. All the theoretical analysis further provides convincing evidences to the impedance results.