Fluorescence-Tuned Silicone Elastomers for Multicolored Ultraviolet Light-Emitting Diodes: Realizing the Processability of Polyhedral Oligomeric Silsesquioxane-Based Hybrid Porous Polymers

Processability has always been a challenge for most insoluble porous materials. Herein, we report a facile approach to realize their processability by physically blending them into a thiol-containing polysiloxane matrix (PMMS) followed by an efficient thiol-ene cross-linking reaction, resulting in novel silicone elastomers. The applied porous materials are polyhedral oligomeric silsesquioxane-based hybrid porous polymers (HPPs), which were prepared by the Heck reactions of octavinylsilsesquioxane with 4,4'-dibrombiphenyl and/or 1,3,6,8-tetrabromopyrene. They exhibit tunable fluorescence with a continuous color change from blue to red by altering the molar ratio of biphenyl and pyrene units. This remarkable fluorescence modulation endows the elastomers incorporated with HPP materials similar multicolor emissions from blue to red depending on the added HPP. It was observed that HPP materials were well dispersed in the polymeric matrix when the amount of HPPs was below 20 mg per gram of PMMS. Furthermore, multicolored ultraviolet light-emitting diodes (UV-LEDs) based on these silicone elastomers were constructed by an in situ cross-linking method; the devices show a color-transformable property by controlling the light switches. These results reveal that blending insoluble porous materials with a polymer matrix is an effective strategy to realize their processability and results in novel functional composites. This simple strategy could be certainly expanded to other insoluble porous materials.