Composite materials based on nanoporous SiO2 matrices and squarylium dye

Abstract Sol–gel SiO 2 matrices with different contents of HF acid were synthesized. The matrices were annealed at 600 °C and impregnated with squarylium dye SqD1 in methylmethacrylate (MMA) solvent. Xerogel nanoporous structure of SiO 2 matrices was found to contain 5–12 nm and 60–600 nm pores. The size of large pores increases with the concentration of HF acid. For the synthesis of SiO 2 matrices the ratio n(HF/TEOS) = 0.25–0.38 is the most optimal. At other HF concentrations the formed matrices are prone to cracking at drying, annealing and impregnation with the dye solution in MMA. The location of the maxima of the absorption and luminescence bands of SqD1 dye in the composite SiO 2 :SqD1:ММА is found to be influenced by the surface state of SiO 2 xerogel depending on the concentration of HF acid at the synthesis of the matrices.