Synthesis And Characterization Of Polyaniline And Its Derivative Micro/Nano Structures

In this paper, micro/nanostructures of Polyaniline and its derivative(Poly(p-phenylenediamine)) were synthesized and systematically investigated. B-type molybdopolyanions containing tervalent metal ion(Co)(abbreviation: Co-Mo) were used as a new oxidant to synthesize Polyaniline with various morphologies. Possible formation mechanisms as well as structure characterization were described in detail. The effects of L-Lysine on the morphology of Poly(p-phenylenediamine) were also disscued. All results and conclusions obtained are listed below.(1)Polyaniline micro/nanospheres with uniform particle size and Polyaniline microflakes can be easily synthesized with Co-Mo as a new oxidant. The concentration of monomer and oxidant, the reaction temperature and the acidity of the solution all had influence on the morphology of Polyaniline. When the concentration of aniline monomer and oxidant were 0.1M and 0.04 M respectively, uniform Polyaniilne micro/nanospheres with diameters of about 170-280 nm were obtained. The micro/nanospheres will fused together when the monomer concentration was decreased to 0.01 M or increased to 0.02 M, along with the increasing of oxidant concentration(40m M) or reaction temperation(60℃). The morphology control of Polyaniilne can be achieved by adding trace additives. XRD results indicate that the product was amorphous. FTIR, UV-vis, EA, XRD and NMR results indicate that Co-Mo had successfully doped into Polyaniline. The fluorescence analytical results indicate that the acidity of the solution had an effect on Polyaniline’s fluorescent property, the maximum fluorescence emission was blueshifted from 428 nm to 402 nm with the p H value of the solution increased from 1.3 to 5.7.High acid environment could benefit for the formation of Polyaniline microflakes, and the possible formation mechanism was also derived with the aid of test means(FTIR, SEM, EDS, UV-vis etc.). It was found that aniline salts and Co-Mo could form into flake shape complex and served as template for the growth of Polyaniline, the final size of Polyanline microflake were 8-10μm on each side and 400 nm in thickness. XRD results indicate that the Polyaniline microflakes were amorphous.(2) Poly(p-phenylenediamine) sub-microrods with rectangular cross section, which doped by L-lys were successfully prepared. The concentration of monomer and L-lys, the reaction temperature and the acidity of the solution all had influence on the morphology of Pp PD. When the concentration of L-lys, p PD and APS were 0.05M(p H=8.3), Pp PD sub-microrods with rectangular cross section were obtained. The length of the sub-microrods can be reached to at least 10μm, while the side of the cross section varies from 300 to 400 nm. The thermal analysis shows that Pp PD doped with L-lys has better thermal stability. The fluorescence analytical results indicate that the acidity of the envorement has an effect on Pp PD’s fluorescence behavior. XRD results indicate that the product was amorphous. The analysis of the adsorptive ability of lead ions on Pp PD has been investigated by a series of experiments. The results suggest that Pp PD doped with L-lys has better adsorptivity and adsorption capacity. When the dosage of Pp PD(doped with L-lys) polymer is 50 mg, and the Pb2+ concentration is 600mg/L(20m L), the adsorption capacity and adsorptivity of Pb2+ ions can reach to 87% and 219mg/g respectively, while the adsorption capacity and adsorptivity was 66% and 157mg/g respectively for Pp PD prepared by conventional method.