Electrochemical control of surface hydrophilicity in azobenzene-functionalized polycarbazole electrochromic thin film

In this study, we report synthesizing and characterizing an azobenzene-functionalized polycarbazole thin film with electrochromic and switchable surface hydrophilicity properties. The electroactive monomer, containing an azobenzene photoswitch and a carbazole moiety, was electropolymerized to form a stable film on a conductive substrate. The resulting polycarbazole-based thin film displayed reversible electrochromic behavior, with a distinct magenta color emerging upon reduction of the azobenzene group, a feature not observed in traditional polycarbazole electrochromic films. In addition to its electrochromic response, the film demonstrated tunable surface hydrophilicity that could be modulated by applying an external potential. This unique dual functionality color change and reversible surface wettability offers significant potential for applications in optoelectronic devices, smart coatings, and surface-modifiable interfaces.