Preparation Of Conducting Pani And Study On Their Nanostructures

Conducting polyaniline(PANI) films have been prepared by chemical oxidation and electrochemical polymerization methods. The influences of the proton acids types, thermal treatment temperature, and metallic ions on the morphology and conductivity of PANI were studied. X-ray diffraction (XRD) and Atomic force microscopy are used to analyze the microstructure characteristics of PANI, such as crystalline fraction and crystal size. Ultraviolet-visible (UV-Vis) transmission and reflection measurements are performed to investigate the optical absorption properties. Combining with the microstructure characterization and the optical absorption analysis, the relations of conductivity and the microstructure are discussed in detail. The main results are described as follows:The effects of proton acids types and thermal treatment temperature are studied on the microstructure and conductivity of PANI. The conductivity value of PANI-H2SO4 is maximal because of the large size contra-anion of proton acid, which making molecule chain stretching and being in favor of electric charge transmit. The crystal size can increase by increasing thermal treatment temperature properly.The effects of metallic ions on the structures and conductivity of PANI films are discussed. It has been shown that increasing of iron ion concentration is beneficial to not only enhancing structure order degree and conductivity but also increasing crystal size.The ordered films are obtained by adjusting polymerization potential and aniline concentration in electrochemical process. The analysis of optical absorption indicates that the proton acid doping can be restrained due to the high potential. In addition, the change of aniline concentration under the same condition of polymerization potential plays an important role in the microscopy of PANI films.