Preparation, characterization and applications of electroactive polymers in electrochromism and sensors

A series of novel monomers was synthesized. Some of them contain perylene-3, 4, 9, 10-tetracarboxylic diimide or naphthalene-1, 4, 5, 8-tetracarboxylic diimide units and diphenylamine endgroups. Some of them are metal complexes that contain diphenylamine endgroups. All monomers can be electropolymerized easily at the surface of electrodes. The polymer films were characterized by cyclic voltammetry, spectroelectrochemistry and Electrochemical Quartz crystal microbalance (EQCM). By modification of perylene rings and diphenylamine endgroups, the monomers have better Solubilities in common organic solvents. More interestingly, binding four chlorines to perylene rings decreases the reduction potentials and makes polymer films extremely stable in reduction states. By using a series of electroactive polymer films that contain tetrachloroperylene-3, 4, 9, 10-tetracarboxylic diimide units as electrochromic materials, some electrochromic windows with excellent stability, high transmittance ratio and fast response time were developed.; In developing electrochromic devices, obtaining stable and electroactive counter electrode's materials is also very important. A new electroactive polymer film, polyallylammonium ferrocyanide film, was developed. This electroactive polymer film is very stable and transparent in both the reduced state and the oxidized state, so it was used as the counter-electrode material for the electrochromic windows developed here. The electroactivity of polyallylammonium ferrocyanide films was found to depend on the amount of trace water in them. This property of polyallylammonium ferrocyanide film led to the development of two electrochemical methods to determine trace water in organic solvents. One method is to determine trace water in organic solvents according to charge consumed during the oxidation of polyallylammonium ferrocyanide film and the other is to determine trace water according to conductivity of polyallylammonium ferrocyanide/ferricyanide film deposited on electrodes in a sandwich configuration. Trace water in four halogenated solvents has been determined with the measurement of charge consumed. The procedure is simple and the detection limit is low. For the measurement of conductivity, It was found that with a low concentration of water there is a linear relationship between the conductivity of the film on electrodes in a sandwich configuration and the percentage of water in 1,2-dichloroethane.