Synthesis and characterization of electrochromic polyurea containing oligoanilines and silicon groups

Electrochromic materials have attracted much attention due to their potential in intelligent applications. We report here the preparation of a crosslinked electrochromic polyurea containing oligoanilines and silicon groups (PUOSi), which shows good thermostability and interesting spectral properties. The crosslinked network structure (c-PUOSi) could be accomplished easily by virtue of hydrolysis reaction. The reversible electrochemical activity and improved electrochromic behavior have been disclosed through multiple electrochemical techniques coupled with UV-Vis spectroscopy. The stability of c-PUOSi film in the electrochemical switching measurements has been effectively enhanced through the crosslinking reaction of triethoxysilane end groups, whilst the resulting densified electroactive film shows low response speed during the electrochemical process. Our demonstrated system presents a deep understanding of structure-function relationship, which is a vital implication for the fabrication and application of the electrochromic devices.