Research On The Polymerization And Properties Of Nanostructured Polyaniline

Among the family of conducting polymers, PANI is cheap and abundant, which can be easily polymerized, with high conductivity and a broad prospect for application. In this thesis, three kinds of polyaniline nanostructures have been fabricated by different chemical oxidative. Moreover, polyaniline film doped with chloride ion is easily fabricated on platinum electrode (Polyaniline/Pt) by potentiostatic method. The electrochemical behavior and electro-catalysis activity of Polyaniline/Pt in hydroquinone solution were characterized using cyclic voltammetry. Finally, hydrogen peroxide is used as the oxidant to synthesize the Polyaniline/Carbon Nanotube composite material. The body of the thesis is divided into 3 sections:(1)Using p-toluene sulfonic acid as the dopant and ammonium persulfate as the oxidant, the nanoparticles of polyaniline has been fabricated. The amount of oxidant on the yield and the conductivity of polyaniline is discussed. Experiment results show that when n (Ammoniumpersulfate):n(Aniline)=1, yield is 68%, conductivity is about 1.78 s/cm. Extending the reaction time can improve the yield of polyaniline. The yield is higher when the reaction time is 6 h at room temperature. Meanwhile SEM analysis shows that the microstructure of polyaniline is nanoparticle, particle size is uniform. The diameter of particles is from dozens of nanometer to tens of micrometer. Sheet-like Polyaniline with controllable size has been successfully fabricated by a simple, novel, cost-effective, and environmentally benign strategy. The effect of experimental parameters, such as the kind of dopants and concentration of aniline system, on the morphologies of the Polyaniline micro/nanosheets has been systematically investigated. Experiment results show that the lateral dimensions of sheet-like Polyaniline synthesized using different protonic acids were in the order of HCl media, HClO₄ media, H₂SO₄ media. The monomer concentration has almost no obvious impact on the morphology but has a significant impact on the polymerization rate of the Polyaniline micro/nanosheets. On the other hand, a general and viable oxidative template assembly (OTA) approach for control of 2-D nanoclips in conducting polymers is reported. Its characteristics are as follows: the use of an oxidative template as a"universal method"to synthesize rapidly, in one step, reaction process is simple; a folded twin-tailed model for complex whose lamellar packing orchestrates nanoclip formation.(2) Polyaniline film doped with chloride ion is easily fabricated on platinum electrode (Polyaniline/Pt) by potentiostatic method. The electrochemical behavior and electro-catalysis activity of Polyaniline/Pt in hydroquinone solution were characterized using cyclic voltammetry. The results show that the best electric potential should be between 0.7～0.9V; Several other factors such as concentration of sulfuric acid,hydrochloric acid and scan rate have great effect on PANI film'cyclic voltammetry characters and electro-catalysis activity.(3) Using chemical in-situ polymerization, H₂O₂ as the oxidant, Polyaniline/Carbon Nanotube composite material is prepared. The conductivity and thermal stability of the composite material is discussed. Experimental results show that when m(Polyaniline):m(Carbon Nanotube)=10:1 in composite material, the conductivity is the largest. The thermal stability of Polyaniline/Carbon Nanotube is rather higher than Polyaniline.