Electrochemical Synthesis and Applications of Copolymer Consisting of Aniline and Its Derivatives

• Main Authors: Yi-Hsin Chen, 陳逸信
• Other Authors: Ten-Chin Wen
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/sf7et4

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 90 === Aniline copolymer using electrochemical synthesis is studied in this dissertation. Emphasis is different according to different copolymer with unlike comonoer. The copolymer consisting of aniline and 5-aminoisoquinoline is emphasis upon the copolymerization process, properties of the resulting polymer and the application for modified electrode. The copolymer consisting of aniline and diphenylamine is emphasis upon the spectral characteristics in different pH conditions. Recent developments in the field of conducting polymer have led to a variety of materials with great potentials for applications. Among these polymers, polyaniline (PANI) is one of the most interesting materials. In order to obtain improved properties for PANI for wider applications, several approaches like copolymerization of aniline and its derivatives are also been emphasized. Keeping this view, the objective of this dissertation puts emphasis on the electrochemical characteristics and properties of conducting copolymer based on aniline with 5-aminoisoquinoline and diphenylamine, separatively. 5-aminoisoquinoline (AIQ), a bifunctional monomer, having an aniline type –NH2 group and a –C=N-C group in quinoline ring, was specifically electropolymerized utilizing the –NH2 groups to leave the –C=N-C groups in the ring intact in the resulted polymer. Electrochemical characteristics for the polymerization of mixture of aniline (ANI) and AIQ was investigated via cyclic voltammetry. Individual electrochemical homopolymerization studies for ANI and AIQ were also performed to deduce the changes in the electrochemical characteristics during polymerization with ANI and AIQ together. X-ray photoelectron spectroscopy (XPS) was employed to find the elemental composition and proportion of reduced units in the copolymer. The presence of –C=N-C groups in the copolymer is evident from XPS and insitu spectra electrochemical results. Double potential chronocoulometry was used to obtain the diffusion characteristics of the copolymer film modified electrode. Oxidation of hydroquinone was performed on the copolymer film modified electrode. We could find that though the electroactivity of copolymer film is less active than one of PANI, the copolymer film still shows diffusion characteristics which make the electron transfer reaction possible on copolymer modified electrode. Diphenylamine (DPA), was used to tune the pKa of the films of PANI in pH sensing. The films of PANI, poly(diphenylamine) (PDPA) and the copolymer of ANI and DPA were coated on ITO coated glass plate and kept at different pH conditions to observe the changes in UV-Visible spectral characteristics. These films behave differently towards pH variations because of their different structure. The spectral characteristics of copolymer were similar to ones of PDPA. Upon increasing the pH from 2.15 to 3.40, UV-Visible spectrum of copolymer shows the distinct changes in peak positions and absorbance. As a result, we could understand that the sensing range of copolymer is under the more acid medium and different form PANI.