Gelatin-assisted templating route to synthesize sponge-like mesoporous silica with bimodal porosity and lysozyme adsorption behavior

Sponge-like mesoporous silica (SMS) was prepared using a gelatin-assisted templating route with dodecyl amine (DDA) as the main template. The synthesized SMS showed a bimodal pore size distribution, with mesopores of 3.2 nm and texture pores of 50-80 nm. We found that gelatin (GE) had a pronounced effect on the morphology and porosity of the synthesized silica, which was then extensively investigated by electron microscopy. When the mass ratio of GE to DDA, M-GE/M-DDA, was increased from 0.05 to 0.6, the morphology evolved from a sponge-like sphere to a hollow sphere, and finally to a popcorn-like hollow sphere. It was also found that the porosity could be modulated by changing the GE concentration. Due to its unique bimodal porosity, the synthesized SMS demonstrated a higher adsorption capacity and faster lysozyme adsorption rate, making SMS potentially applicable in the immobilization of enzymes with high capacity and bio-activity. (C) 2011 Elsevier Inc. All rights reserved.