Controlled Synthesis And Properties Of Poly3-thiophene Acetic Acid And Polyaniline Micro/nanostructures

Nano/micrometer-sized conducting polymers have the features of usual conducting polymers and special properties of nanomaterials. Thus, they have various potential applications in catalysis, actuators, optics and microelectronics, etc. In view of the application of these materials, it is important to fabricate nanostructured conducting polymers with controllable morphology and sizes. Electrosysthesis is a convenient and effective route to obtain nanostructured conducting polymers, because this method can easily control the polymerization rate and the yield of polymer by controlling electropolymerization conditions.In this work is to use the dip-coating technique to obtain an ordered template molecules by electrochemical deposition method, various micro/nanostructured materials of widely studied conducting polymers including poly(3-thiophene acetic acid)(PTAA) and polyaniline(PANI)were fabricated.First, water-soluble macromolecules hydroxyethyl cellulose(HEC), chitosan(Cs), and poly(acrylamide)(PAM) are chosen to prepare the template, respectively, through a dip-coating process, where the macromolecules are spread on an indium tin oxide(ITO) glass in a high yield, monolayer and consistent orientation which is used as the working electrode.We fabricated PTAA nanowires in the mixed electrolyte of boron trifluoride diethyletherate and trifluoro-acetic acid by successive electrochemical depositions of thiophene-3-acetic acid(TAA). The mechanism of microstructure formation is the strong hydrogen bonding between template macromolecules and TAA monomers. The morphology of PTAA is variable by controlling the concentration of the template molecule, monomer concentration and electrochemical polymerization time.Second, polyaniline(PANI) microwires are also fabricated by electrochemical depositions use the templates mentioned above through dip-coating process. Additionally,polyacrylic acid molecule is added into electrolyte, it can play both roles of organic acid dopant and template. Regular PANI nanostructures film can be fabricated through electropolymerization of aniline. Such produced nanostructures were uniform in size. This method differs from the templates method as mentioned above and need no power from outside. The formation of the nanostructures are influenced by kinds of the dopant. Themicro/nanostructured PANI films are very stable and show high electrocatalytic reduction toward H2O2, which makes it an ideal substrate for H2O2 detection and offers great promise for biosensing applications.Third, A ternary graphene/Au/PANI nanocomposite(GAP) is designed and fabricated via a facile two-step approach: Au nanoparticles dispersed on graphene sheets are achieved by a hydrothermal method, followed by coating with PANI through an in situ polymerization process. Electrochemical measurements demonstrate that the specific capacitance of the resulting ternary composite is 572 F·g-1 at a current density of 0.1 A·g-1 using a three-electrode system, which is significantly higher than that of pure PANI and the binary graphene-PANI composite. In addition, over 88.54% of the initial capacitance can be retained after repeating tests for 10000 cycles, demonstrating a high cycling stability. The extraordinary electrochemical performance of the ternary GAP nanocomposite is attributed to its welldesigned nanostructure and the synergistic effects among individual components.