Synthesis of fluorine-contained hyperbranched polysiloxane with blue photoluminescence and research on its fluorescence properties

In order to obtain a new type of aggregation-induced emission (AIE) polymer without traditional chromophore groups and large π-electron conjugates, the fluorine-containing hyperbranched polysiloxane (F-HBPSi) were prepared. The 3,3,3-trifluoropropyl trimethoxysilane and excess neopentyl glycol (NPG) were used as raw materials, and the F-HBPSi with a large number of F–C bonds and hydroxyl groups was successfully synthesized by one-step polycondensation reaction. The fluorescence properties of the F-HBPSi were also studied. Excitingly, the prepared F-HBPSi is able to emit bright blue photoluminescence and exhibit significant ultraviolet absorption when illuminated by an ultraviolet lamp at 365 nm wavelength. It can also be observed that the excitation and emission intensity of the F-HBPSi gradually increased with the increase of their molecular weight, and decreased with the increase of temperature. These indicating that the fluorescence properties of F-HBPSi was related to molecular weight and the temperature. The results also showed that both F–C bonds and hydroxyl groups are important in the formation of blue-emitting species. This work therefore opens up new avenues for designing new luminescent materials.