Fluorescent silica hybrid materials containing benzimidazole dyes obtained by sol-gel method and high pressure processing

▶ Sol-gel technique was used to obtain silica based hybrid materials containing benzimidazole dyes. ▶ The sol-gel catalysts, HF and NaF, produce xerogels with different optical and textural characteristics. ▶ High pressure technique (6.0 GPa) was used to produce fluorescent and transparent silica compacts with the dyes entrapped in closed pores, maintaining their optical properties. ▶ The excited state intramolecular proton transfer (ESIPT) mechanism of benzimidazole dyes was studied by steady-state fluorescence spectroscopy for the monoliths, powders, and compacts.