Electropolymerization And Electrochromic Properties Of Conducting Polymers

Electrochromism refers to a phenomenon that a material changes colors when the material takes place reversible redox reaction induced by applied voltage. People are paying more attention on electrochromic materials because of their wide application prospects on display devices, smart windows, glarefree mirror, military camouflage et al. Although conducting polymers are new members of electrochromic materials, they'll be the concentration of the study in electrochromism on account of their rapid response times, abundant color changes, easy processing, facile molecular design, low costs and so on.In this article, conducting polymers (PANI, PEDOT) were chosen as electrochromic materials; in order to improve the electrochromic properties and optical contrast ratios(?T%), the research work below were undergoing through electrochemical means: 1. Conducting PANI membranes with excellent electrochromic performances were electrochemically polymerized through potentialstatic method, by optimizing the polymerization conditions and test conditions. The results show that, under the optimal polymerization conditions and test conditions, the obtained PANI membranes could change colors from yellow to green and blue, the responsing time was about 2.8s, and the optical contrast ratio between yellow and blue was 35%; afterwards, in order to improve the saturation degree of the color, acid blue BGA was added into the electrolyte, and the results showed the same as we anticipated.2. Conducting PEDOT with better electrochromic performances was obtained under the electrochemical method by means of potentiostatics, by optimizing the polymerization conditions. The results show that, the PEDOT membranes prepared could change colors between light blue and dark blue, the response time was upto about 5s, the optical contrast ratio 42%; besides, its ?T% still remained to be 40% after 250 cycles under the square wave potential of -0.8V/0.6V, which indicated a long life time. In order to associate with the practical application, the area of the membrane was enlarged to 10cm×10cm, which kept obvious color changes, indicating that the membrane has a certain actual application value.3. At last, we prepared PANI and PEDOT nanowires by altering the polymerization conditions, so as to improve the response times. Detailed results wait for further study.