The Research Of Electrochromic Materials Based On Conducting Polymers And Flexible Devices

Electrochromism(EC) can be defined as a reversible and visible change in thetransmittance and/or reflectance of a material by applying different voltages or electriccurrents with the result of electrochemical oxidation or reduction. Electrochromicmaterials have attracted great interests due to their potential use in various applications,such as information display and storage, automotive industry (rear-view mirrors), andsmart windows in green architecture. Recently it is found that electrochromic materialsalso have the ability for modulating of radiation in the near infrared, thermal infraredand microwave regions. In recent years, more and more electrochromic materials thatare capable of modulating radiation in the IR region were reported. Compared to othermateials, conducting polymers have received much attention due to their fine-tunabilityof the band gap, outstanding coloration efficiency, fast switching times, excellentprocessability and low cost.In the paper, carbazoyltriphenylamine (CBZ-TPA), thiophene were studied asinfrared switching electrochromic materials. Two films were obtained byhomopolymerization and copolymerization, including poly-(CBZ-TPA),poly-(CBZ-TPA-thiophene). Moreover, two kinds of flexible electrochromic deviceswere displayed. The specific research work can be divided as follows:1. Electrochromic films based on poly-(CBZ-TPA) were obtained byelectrochemical polymerization method, the electrochromic properties and emissivitywere studied. The results show that different colors of the poly-(CBZ-TPA) film couldbe achieved, which exhibits as camel gray, light gray, army green; the response time ofthe bleached states and the colored state were10s and16s, respectively; the maximumdifference of the UV-vis absorption of the poly-(CBZ-TPA) film is is15.83%between-0.5V and1.6V and the biggest different average emissivity dynamic of thepoly-(CBZ-TPA) film is0.366in the wavelength of8-14μm regions.2. Electrochromic films based on poly-(CBZ-TPA-thiophene) were obtained byelectrochemical polymerization method, the electrochromic properties and emissivitywere studied. The results show that: different colors of the poly-(CBZ-TPA-thiophene) film could be achieved, which exhibits as maize-yellow, milk white, dark green; theresponse time of the bleached states and the colored state were12s and16s,respectively; the maximum difference of the UV-vis absorption of the poly-(CBZ-TPA-thiophene) film is is23.3%between-0.5V and1.4V and the biggest different averageemissivity dynamic of the poly-(CBZ-TPA-thiophene) film is0.411in the wavelengthof8-14μm regions.3. A new electrochromic device was designed, which was assembled by PET-ITO,organic membrane deposited of polyaniline, filter paper adsorbing electrolytes andPET-ITO in sequence.4. Another new electrochromic device was designed, which was assembled by thePET film, organic membrane gold film deposited of polyaniline, filter paper adsorbingelectrolytes, Cu foil and PET film in sequence. The results show that the flexible devicecan achieve a reversible color change.