Journal of the Electrochemical Society, Vol.143, No.8, 2591-2596, 1996
Large-Area Electrochromic Coatings - Composites of Polyaniline and Polyacrylate-Silica Hybrid Set Gel Materials
A low-cost technique for fabricating large-area electrochromic coatings is described. Polyaniline was incorporated into polyacrylate-silica hybrid sol-gel networks using suspended particles or solutions. A solution of polyaniline and poly[methyl methacrylate-co-3-(trimethoxysilyl)propyl methacrylate] can be spray- or brush-coated on transparent indium-tin oxide substrates to form robust electrochromic coatings. Silane functional groups on the polyacrylate chain act as coupling and cross-linking agents to improve surface adhesion and mechanical properties of the resulting composite coatings. These coatings showed reversible transparent to green color change when polarized at potentials between -0.4 and +0.4 V vs. Ag/AgCl in a 0.2 M LiClO4/acetonitrile electrolyte solution. The cycle lifetimes of polyaniline films were improved by incorporating the polymer in the polyacrylate-silica matrix. Electrochromic switching was demonstrated for the composite coatings in large-area all-solid-state devices.
Keywords:CONDUCTING POLYMERS;OPTICAL-PROPERTIES;FILMS;POLYPYRROLE;STATE;ELECTROLYTE;STABILITY;OXIDATION;DEVICES;CELL