Synthesis and pore size control of porous materials through self-assembly of silica-surfactant

Abstract

Porous silica molecular sieves have been prepared by the hydrolysis of tetraethylorthosilicate (TEOS) in the presence of low-cost, nontoxic, and biodegradable polyethylene oxide (PEO) and polypropylene oxide (PPO) surfactants, which act as the structure-directing templating agents. This nonionic, surfactant-neutral, inorganic precursor templating pathway to porous nanostructures uses hydrogen bonding interactions between the hydrophilic surfaces of flexible rod- or worm-like micelles and Si(OC2H5)4-x(OH)x hydrolysis products to assemble an inorganic oxide framework. High order chanel structures with uniform diameter ranging from 2 7.5 nm have been obtained by varying the size and structure of the surfactant molecules.The synthesis of silica-surfactant porous nanostructures has been studied under various acidic conditions.