Electropolymerization and electrochromism of poly(4,7-dithien-2-yl-2,1,3-benzothiadiazole) and its copolymer with 3-methoxythiophene in ionic liquids

Abstract

This thesis is based on the study of electropolymerization and electrochromism of poly(4,7- dithien-2-yl-2,1,3-benzothiadiazole) (P(DTBT) and its copolymer with 3-methoxythiophene (MOT) in imidazolium ionic liquids (ILs) 1-butyl-3-methylimidazolium tetrafluoroborate (bmimbf4) hydrophilic, 1-butyl-3-methylimidazolium hexafluorophosphate (bmimpf6) and 1- butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (bmimtnf2) hydrophobic ILs. Traditional organic solvents acetonitrile and dichloromethane in the presence of 0.1 M tetrabutylammonium perchlorate (n-Bu4NClO4) as a supportive electrolyte was also used as a medium for comparison. Besides, a more hydrophobic ionic liquid, 1-octyl-3- methylimidazolium bis(trifluoromethylsulfonyl)imide (octmimtnf2) was also used for the electrodeposition of poly(3-methoxythiophene) (PMOT). The techniques employed are cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), uv-visible spectroelectrochemistry and scanning electron microscopy (SEM). 4,7-Dithien-2-yl-2,1,3-benzothiadiazole (DTBT) a type of donor –acceptor monomer and 3- methoxythiophene (MOT) has been electropolymerized using ionic liquids as growth and supportive electrolytes.