Synthesis And Electrochemical Properties Of Organic Electrochromic Materials Containing Thiophenes

As a kind of novel intelligent materials, electrochromic materials have drawn lots of attentions. Among them, conducting polymers are considered as research topic by many scientific researchers. Polythiophene and its derivatives have a good application prospect in organic and polymeric optoelectronic devices, because of its high conductivity, strong stability, and tunable band-gap. In this article, we synthesized a variety of monomers via coupling reaction and electrochemical polymerization, and studied the photoelectric properties.Six novel monomers(ETPC, MTPC, TPC and PTQ, PBTQ, PETQ) were successfully synthesized via coupling reaction, and two new copolymers(P(CBP-co-CPDT), P(TTPA-co-BT)) were successfully achieved by electrochemical oxidation. Characterizations of all polymers were performed by cyclic voltammetry(CV), Fourier transform infrared spectroscopy(FT-IR), UV-vis-NIR spectroscopy and scanning electron microscopy(SEM). The experimental results showed that they could realize the tunableness of the band gap. And it was interesting to find that slight structural difference of the polymers could result in the variation of the optical and electronic properties. All polymers had good stability, satisfactory coloration efficiency, fast response time, high optical contrast. Polymers, which contained 3,4-ethylenedioxythiophene(EDOT) or 3-methoxythiophene, had more obvious electrochromic properties.For further research of electrochromic devices conducting thiophene units in the application of organic optoelectronic devices, this paper constructed two electrochromic devices, P(CBP-co-CPDT)/PEDOT and P(TTPA-co-BT)/PEDOT. The PEDOT was cathodic materials, two other copolymer were the anodic material. Electrochromic devices(ECDs) had good photoelectrical properties, and this showed that they had the well commercial application prospect.