Surface Wettability Control of Polyimides Containing Perfluoroalkyl Group by Photo-irradiation

The novel polyimides containing perfluoroalkyl group on their side chain were synthesized using the novel diamine monomers containing perfluoroalkyl group. The films of obtained polyimides on glass substrates were prepared and the surface wettability of these films were measured before and after UV (ultraviolet) light irradiation (254 nm). The water contact angles of these polyimide films were changed from about 113° to 56° by UV light irradiation. The novel polyimides containing both perfluoroalkyl group and spiropyran group was synthesized by introducing spiropyran group by Mitsunobu reaction with base polyimide containing phenolic OH group. The surface wettability of the polyimide film containing the spiropyran group changes from about 114° to about 104° by irradiation of UV light (365 nm), and reversibly changes from about 104° to about 114° by irradiation of Vis (visible) light.