Studies On The Synthesis Of Soluble Polyaniline Catalyzed By Horseradish Peroxidase

The thesis consists of three parts as follows: Part I: ReviewIt looks back to the development and the research advancement of enzyme, the versatile applications of polyaniline (PAn), the synthetic methods of PAn. The methods for the synthesis of PAn was summarized and made contrast. It emphasized on the technology of enzyme-catalyzed synthesis of PAn, and HRP, SBP, Laccase were also introduced. As a kind of newly means for the synthesis of polymer, the prospects and the challenge that HRP catalyze to produce PAn faced were also discussed in this part.Part II: Synthesis and characterization of poiyaniline by HRP-catalyzed polymerization of p-phenylenediamineIn this part, the ployaniline (PAn) were obtained by HRP-catalyzed polymerization of p-phenylenediamine in aqueous/1, 4-dioxane solvent. The influence factors, such as polymerization time, the concentration of the organic solvent, were studied, The structure of polymer was characterized by UV-Vis and FT-IR spectroscopies, the molecular weight of PAn was determined by GPC.Part HI: Synthesis and characterization of water-soluble polyaniline by HRPThe part consists of four subsections, and was emphasized on the synthesis of water-soluble polyaniline. The PAn-I was produced by the Schiff base derived from p-aminobenzene sulfonic acid, and p-phenylenediamine was another monomer. The first subsection included the obtaining of blue-black powder PAn-I catalyzed by HRP combined with H2O2 as the oxidant. The second subsection includes the preparation of black copolymer powder PAn-II by HRP as catalyst, H2O2 oxidizing, p-phenylenediamine and acrylic acid were monomers. In the third subsection, glucosamine was employed into polyaniline, which is hydrophilic monomer. With HRP as catalyst and H2O2 as oxidant, the brown powder PAn-III was produced. Theproduct is easy water-soluble rather than other organic solvent compared to PAn-I, PAn-II. In the forth subsection, the synthesized polymers, such as PAn, PAn-I, PAn-II, PAn-III, were made contrast.The characterization of the PAn-I, PAn-II, PAn-III was carried out using UV-Vis and FT-IR spectroscopy, Cyclic voltammetr, and their molecular weights was determined by GPC, the thermal stability was determined by TG/DTA. All of the results confirmed that the electroactive, the thermal stability and easy water-soluble polyaniline (PAn-I, PAn-II, PAn-III) were synthesized by the horseradish peroxidase catalyzed polymerization of p-phenylenediamine and other hydrophilic monomer. Furthermore, PAn-II is better than others in the aspects of electrochemically active and thermal stability. The most important is that the PAn-I, PAn-II, PAn-III expressed high solubility in aqueous solution. PAn-III is the most excellent one, which is very easy water-soluble than other polyaniline and it is not soluble in organic solvent. It should be noted that for polyaniline, being soluble and processable, is sometimes more important than being highly conductive. Part IV: Studies on the kinetics of Horseradish Peroxidase-catalyzed synthesis ofPAn-IIIn this part, we study the kinetics of Horseradish Peroxidase-catalyzed polymerization of p-phenylenediamine and acrylic acid, which was mentioned in chapter3. The influences of pH value as well as the concentration of p-phenylenediamine upon the rate of reaction were studied. The Km (Michaelis-Menten constant), Vm (maximum velocity) were obtained by the curves of kinetics according Michaelis-Menten equation.