Assembly of Mesoporous Molecular Sieves Containing Wormhole Motifs by a Nonionic Surfactant Pathway: Control of Pore Size by Synthesis Temperature

Abstract

Nonionic polyethylene oxide surfactants are versatile structure-directing agents for the assembly of mesoporous molecular sieves, but their greatest benefit may lie in their ability to control the pore size of the mesostructure by the assembly temperature (see dependence of pore diameter R on temperature shown on the right). For mesostructured silicas with wormhole motifs, the average pore diameter can be altered by as much as 2.4 nm by varying the assembly temperature over a relatively narrow range below the cloud point temperature of the surfactant.