Nonionic triblock copolymer synthesis of SBA-15 above the isoelectric point of silica (pH = 2–5)

Under new mild conditions, above the isoelectric point of silica (pH = 2–5), SBA-15 mesoporous silica with ordered hexagonal pores were prepared by pre-hydrolyzing of tetraethyl orthosilicate in the presence of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) as a template. Small angle X-ray scattering (SAXS), nitrogen adsorption and desorption experiments, and transmission electron micrograph (TEM) measurements showed well-ordered hexagonal array structure, though there are some changes in wall thickness and density with the increase of pH value from 2 to 5.