Preparation, Characterization of Styrene-Functional Hyperbranched Viologen, and Its Application in Optical Writing and Electrical Erasing Device.

Styrene-functional hyperbranched viologen (SHBV2+) was successfully synthesized and characterized in detail by FTIR,1H NMR, and XPS spectra, respectively. Subsequently, it was cured by visible light to obtain cross-linked hyperbranched viologen film. It is noteworthy that cross-linked SHBV2+film possessed better photochromic and electrochromic performances. After UV illumination for 60 s, the cross-linked SHBV2+film can swiftly change its color from pale yellow to deep bluish violet, whereas the absorbance of SHBV2+film at 610 nm did not change significantly and was still retained about 0.423 after 20 coloring/bleaching cycles. The single-type SHBV2+EC device can undergo reversible color change in response to the alternate external voltages of −2.0 V and 2.0 V, respectively, while the changes in optical transmission and charge density of EC device at 550 nm did not deteriorate significantly and still remained about 48.2% and 13.85 mC·cm−2after 10 coloring/bleaching cycles. Furthermore, single-type SHBV2+PEC device possessed better optical writing and electrical erasing performances. After 10 repeated writing/erasing cycles, the contrast did not decrease significantly and still remained about 48.0%, while the electrical erasing time did not deteriorate significantly and remained about 22.0 s. This device can realize rapid storage, modulation, and erasing of optical information. [ABSTRACT FROM PUBLISHER]