Electrochemical polymerization of aniline on Au(111) and Au(100) in camphor-sulfonic acid and tartaric acid

• Main Authors: Ya-ling Chuang, 莊雅玲
• Other Authors: Shueh-lin Yau
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/50695091619108506870

碩士 === 國立中央大學 === 化學研究所 === 99 === In situ scanning tunneling microscopy (STM) and cyclic voltammetry (CV) have been used to explore the adsorption and electropolymerization of aniline on ordered Au(111) and Au(100) electrodes in 0.1 M organic acid of D-(+)- or L-(-)-camphor-sulphonic acid or D-(-)- and L-(+)-tartaric acid (TA). Molecular resolution STM imaging revealed aniline molecules were arranged differently in D-(+)- and L-(-)-camphor-sulphonic acid. The coverages and structures of aniline and coadsorbed anions could vary with the potential of gold electrodes. D-(+)- and L-(-)-camphor-sulphonic acid were able to induce 3-D helical molecular conformations of polyaniline at E > 0.95 V. On the other hand, different structures were obtained on Au(111) and Au(100) surfaces in electrolyte solutions containing aniline and D-(+)- or L-(-)-tartaric acid. Electropolymerization aniline also produced polyaniline wires with helix-like shape, which could be induced by the coadsorbed D-(-)- and L-(+)-tartaric acids. Interestingly, aniline molecules were organized differently on Au(100) electrode in D-(-)- and L-(+)-tartaric acids. Polyaniline grew linearly along the √10 direction in D-(-)- tartaric acid, followed by re-configuration into helix-like shape as oxidation of aniline continued. My studies show that chiral dopants of organic acids for polyaniline could induce specific conformational on Au(111) and Au(100) electrode surfaces. STM imaging has unveiled helical-shaped polyaniline chain in the presence of D- and L-organic acid, which could yield some fundamental insights into its potential applications in fabrication of chemical and biological sensors, chiral catalysis, pharmaceutics, and enantioselective separation.