Catalase immobilized on siliceous mesocellular foam with controlled window size

Abstract

Siliceous mesocellular foam (MCF) with tunable cell and window size was synthesized by the acid catalyzed sol–gel reaction of tetraethoxysilane in the presence of triblock copolymer Pluronic P123 (EO20PO70EO20) as structure-directing agent. The cell’s size of MCF is increased with the increase of 1,3,5-trimethylbenzene amount, while the window’s size of MCF could be tailored between 4 and 18.2 nm without affecting the cells size by adding of NH4F. The obtained MCF materials were employed as carriers for catalase immobilization. FT-IR spectra and N2 sorption show that the catalase is immobilized into the mesopores of MCF. MCF with window size of 12.9 nm shows high catalase loading and activity, suggesting that matching the window’s size with enzyme molecular diameter is a critical factor in attaining efficient immobilization since smaller window size prevents larger enzyme from entering the pore and larger window size causes the leakage of enzyme. The thermal and storage stabilities of the immobilized catalase were also improved due to the shield of the mesopores of MCF.