Preparation And Properties Of Conjugated Polymer Electrochromic Materials Based On 3,4-ethylenedioxythiophene

With the rapid development of recent information electronic equipment,human's requirement for multicolor display is getting higher.As an energy-efficient material,electrochromic(EC)materials exhibit different colors under different voltages,which can satisfy people's growing demands for material life.Early studies of EC materials mainly focused on inorganic EC materials because of their low-cost and stability.With the development of science and technology,more and more organic EC materials for multicolor display come out,among which conjugated polymers have become one of the hot pots in recent years.Poly-3,4-ethylenedioxythiophene(PEDOT)is an excellent EC material which has high electrical conductivity(600 S/cm),greater stability and higher visible light transmittance.In this paper,based on 3,4-ethylenedioxythiophene(EDOT),we conducted homopolymerization and prepared two kinds of PEDOT nanowire films.These two kinds of films had some differences in structure and electrochromic properties.In order to further expand EDOT in the field of electrochromism,we coploymerized EDOT and pyrrole-3-carboxylic acid(P3C)at different molar ratios and we got four novel electrochromic films with excellent properties.In the first part of this dissertation,PEDOT-CV and PEDOT-CP nanowire films were electrochemically polymerized by cyclic voltammetry and potentiostatic method and they showed differences in electrochromic performance.Thebleaching time of PEDOT-CV was 0.47 s at 632 nm and the coloring time was 1.23 s.The bleaching time of PEDOT-CP at 633.5 nm was 0.51 s and the coloring time was 0.66 s.In the second part of this dissertation,P3 C and EDOT were electrochemically copolymerized at different molar ratios and we obtained four copolymer films: P(EDOT:P3C)-1,P(EDOT:P3C)-3,P(EDOT:P3C)-5 and P(EDOT:P3C)-10 which were capable of exhibiting abundant color changes.The optical contrast of P(EDOT:P3C)-1 was 40% at 1100 nm and its switching time was 1.33 s at 500 nm;the switching time of P(EDOT:P3C)-3 was only 0.54 s at 523 nm and it's 1.22 s for P(EDOT:P3C)-5 at 561 nm.The electrochromic device assembled by P(EDOT:P3C)-1 displayed different colors at different voltages,which indicated that the polymer had actual potential for application.In the third part of this dissertation,a new multicolor copolymer EC material P(EDOT:P3C)-1-Ti contained with polyoxotitanate cluster group was prepared.Atomic force microscopy photographs showed that the material had good facial uniformity and no apparent phase separation.The spectral electrochemical tests showed that the contrast ratio of P(EDOT:P3C)-1-Ti was 18.4% at 525 nm and 12.7%at 1100 nm.The corresponding switching time were 0.95 s and 3.81 s.In addition,it also had the ability of catalyzing and oxiding water,which had potential application in electrochemical field.