Pore-expanded mesoporous silica nanoparticles with alkanes/ethanol as pore expanding agent

Pore-expanded mesoporous silica nanoparticles (MSNs) were synthesized using alkanes/ethanol as pore expanding agents. It is found that decane was the most efficient expanding agent to enlarge the pore size of MSNs with the well-ordered mesostructure. In the synthetic method, ethanol was an indispensable co-solvent for mixing oil expanders with aqueous solution to expand the size of cetyltrimethylammonium bromide (CTAB) micelles. The concentration of ammonia solution (NH4OH) can be used to control the particle size, pore size, and pore structure of the MSNs. With optimized amount of ethanol and concentration of NH4OH, a series of pore-expanded MSNs with tunable pore size and well-ordered mesostructure could be synthesized. The well-suspended particle size of the MSNs could be controlled between 50 and 100 nm. These MSNs were used to immobilize lysozyme up to 420 mg g(-1) silica to demonstrate the potential in intra-pore confinement of enzyme. (C) 2012 Elsevier Inc. All rights reserved.