Preparation And Application Of Nanostructured Conductive Polymers

Because of their good environmental stability, facile synthesis approaches and high conductivity, polypyrrole (PPy) and polyaniline (PANI) have been investigated intensively in the last two decades. Properties of conductive polymers depend on their micro/nanostructures, which can be controlled by synthesis method. Therefore, aimed structures can be prepared by suitable experimental approaches. PANI with different nanostructures, mainly nanowires and nanoparticles, is intensively investigated while PANI nanosheet is scarcely reported. Therefore, developing a facile method to prepare PANI nanosheets by molecular self-assembly is valuable both in theory and in technological applications. As a one-dimension nanomaterial, PPy nanowire not only has the properties of bulk conducting polymers, but also has some particular characters, such as higher conductivity, higher surface area and mechanical strength. With these excellent properties, PPy nanowire has great potential applications in molecule conducting wires, modified electrode used in electrocatalysis. Ascorbic acid is one of the most important compounds that have a beneficial function in health-promoting effects. Conveniently and rapidly determination of ascorbic acid attracts much attention for years. Thus, investigating the electrocatalytic ability of PPy toward ascorbic acid is essential to food quality and health care.A facile method to prepare PANI nanosheets at organic/aqueous interface with template-free method was developed. The formation mechanism was proposed and discussed. The experimental results show that the formation of anilinium cation monolayer at the two-phase interface plays an important role for the formation of polyaniline nanosheets. Decreasing the diffusion amount of aniline and shortening the polymerization induction time are favorable for the exclusive obtain polyaniline nanosheets. The polymerization conditions, such as temperature, the proportion of aniline and oxidation, the acidity of the aqueous solution, the thickness of the paraffin layer and the inorganic acid, have different affects on the morphology of PANI. Application of PPy nanowire modified electrode on electrocatalytic oxidation of ascorbic acid was systemically studied by cyclic voltammetric and amperometric methods. The experiment results show that the modified electrodes have obvious electrocatalytic effect toward ascorbic acid oxidation. The oxidation peak current density has a good linearity with the concentration of ascorbic acid. The determination sensitivity may be significantly affected by the potential scanning rate, temperature, pH of the test solution, PPy film thickness.