Synthesis Of Conducting Polymers Poly-2 - Aminopyridine And Nature

1. Synthesis of Poly-2-aminopyridine and Its PropertiesPoly-2-aminopyridine was synthesized using potential cycling in the solution of 0.43 mol dm-3 2-arninopyridine and 0.01 mol dm-3 NaOH. There are three pairs of redox peaks on the cyclic voltammogram of poly-2-aminopyridine in the solution of 1.0 mol dm-3 ZnCl2 (pH 4.99). The experiments of rotating ring-disk electrode(RRDE) indicate that an intermediate is generated in the initiation of polymerization. The IR spectra indicate that poly-2-aminopyridine had head-to-tail structure. According to the results of atom force microscope, the average particle size of poly-2-aminopyridine is about 893 nm, and the average distant between particles is about 255 nm. The behavior of the discharge of the battery which consists the cathode material of poly-2-aminopyridine, the anode of zinc and the electrolytic solution of 2.5 mol dm-3 ZnCl2 and 3.0 mol dm-3 NH4Cl (pH 5.5) is very similar to that of the battery of Li-SOCl2. The discharge curve is very level in the middle region.Poly-2-aminopyridine is synthesized using cyclic voltammetry between 0 V and 1.10 V (vs. SCE). The electrolytic solution consisted of 0.8 mol dm-3 2-aminopyridine, 0.1 mol dm-3 NaOH and 0.01 mol dm-3 sodium benzosulfonate. Sodium benzosulfonate can thicken poly-2-aminopyridine film, but not change its main structure. The charge transfer characteristic of poly-2-aminopyridine in 1.0 mmol.dm-3 CuCl2 solution (pH 3) are influenced by increasing scan rate. The SEM image of poly-2-aminopyridine was also given.2. Electrocatalysis of Uric Acid with Poly-2-aminopyridine-modifiedElectrodeIn the paper electrochemical catalysis of poly-2-aminopyridine to uric acid was introduced. The sensibility of determining uric acid can be controlled by changing the potential of poly-2-aminopyrdline electrode or pH of solution. Poly-2-aminopyridine electrode is more stable than polyaniline-uricase electrode, because the latter is affected by uricase activity. The activation energy (Ea) was 23.0 kJ mol-1. Determining the concentration of uric acid, poly-2-aminopyridine electrode is not influenced by L-ascorbic acid at 0.2 V (vs. SCE).3. Improving in Performance of the Large-scale Zinc-polyanilineSecondary BatteryA large-scale rechargeable battery of Zn/ZnCl2.NH4Cl/polyaniline/carbon is described, in which polyaniline cathode has an apparent area of 60 cm-2 and a thickness of 1.5 cm. The electrolyte consists of 2.5 mol dm-3 ZnCl2, and 3.0 mol dm-3 NH4Cl and 1.0% triton X-100. The experiment result shows that triton X-100 can effectively inhibit zinc dendrite growth when its concentration was over 1.0%. Energy density of polyaniline is 63 Ah kg-1 when the battery is charged and discharged at constant current 1.7 mA cm-2. The energy density of polyaniline in the above solution of pH 4.90 is slightly higher than that of pH 4.40. This is caused by the buffer capacity of the solution. The higher pH value can effectively inhibit the corrosion of the zinc electrode.4. Electrochemical Copolymerization of Aniline and o-ChloroanilineThe electrochemical Copolymerization of aniline and o-chloroaniline in 2mol/L HC1 has been carried out using the potential sweep method. The deposition of copolymeric film was evident from the observed changes in growth rate redox potentials and transport mechanisms of deposited films in contrast to PANI and POCA. FTIR spectra were used to determine the possible structure for copolymer and homopolymers, respectively. The results of SEM and solubility experiment show that the copolymer is not a mixture of homopolymers. The electrochemical properties of copolymer are mainly attributed to polyaniline, but the copolymer has better electrochemical reversibility and solubility in common organic solvents than those of polyaniline.