Research On The Preparation And Properties Of Electrochromic Materials Based On Phenanthrene-9,10-quinone

Owing to the unique properties, conducting polymers have aroused great interest of researchers. These materials are used in many fields, such as electrochromic devices, sensors, solar cells, light emitting diodes and so on. Some conducting polymers can display reversible optical change in absorption under different applied potentials, and these polymers are good candidates of electrochromic materials. The organic conjugated polymers are significant in the electrochromism field, because they have good stability, easy processing and fast switching speeds. What’s more, the structure of organic conjugated materials can be easily modified, so the bandgap can be controlled.In our studies, six different novel organic conjugated polymers were synthesized by electrochemical method. And the corresponding monomers were all obtained via Still coupling reaction. 9,10-Phenanthrenequinone was used as one of the principal raw materials of all monomers due to the fact that it has big conjugated system and the two carbonyl groups in it’s molecule provide good opportunity to the structural modification. All the obtained polymers possess multicolored electrochromism, so they play important roles on electrochromic materials. Among the obtained polymers, poly(10,13-bis(2,3-dihydrothieno [3,4-b][1,4]dioxin-5-yl)dibenzo[a,c]phenazine) and poly(10,13- bis(4-ethylthiophen-2-yl) dibenzo[a,c]phenazine) revealed obvious behaviors of donor-acceptor type polymers.The characterization of the obtained electrochromic materials were performed in detail. Cyclic voltammogram, UV–vis spectroscopy were used to reveal the electrochemical and optical properties of the obtained polymer films. The surface morphologies of them were investigated by scanning electron microscopy(SEM). All the obtained electrochromic materials exhibited satisfactory performance. In addition, dual type electrochromic devices were constructed using the obtained electrochromic polymers as the anode material and the film poly(3,4-ethylenedioxy thiophene) as the cathode material. The spectroelectrochemical properties, switching response, open circuit memory and stability of the electrochromic devices were all studied carefully. The results indicate that the extensive applications of all the obtained electrochromic materials can be easily achieved.