Morphology controlling of micrometer-sized mesoporous silica spheres assisted by polymers of polyethylene glycol and methyl cellulose

Based on the PEG (polyethylene glycol)'s function of bridging flocculation and the MC (methyl cellulose)'s function of formation of liquid crystal in aqueous solution, the morphology of micrometer-sized mesoporous silica spheres with good dispersivity were synthesized by adding the mixture of PEG and MC into the aqueous solution containing F127 and TEOS. It was found that only when PEG was added, the micrometer sized spheres could be synthesized, the spheres possess meso-pores from 2.5 nm to 3.0 nm, and the specific surface area was from 744 m(2)/g to 861 m(2)/g by changing the amount of PEG, but the dispersibility of microspheres needs to be improved. Only when MC was added, the dispersibility of resultant spheres was good, but the out surface of spheres was not smooth. Then, when suitable amount of PEG and MC were simultaneously added, the spheres with good dispersibility and smooth out surface were obtained. (c) 2008 Elsevier Inc. All rights reserved.