Alcothermal synthesis of large pore, high quality MCM-48 silica

摘要

A two-step method to synthesize high-quality MCM-48 with tunable pore size is presented. CTAB is used as a template and various alcohols are used as solvents in the second synthesis step. The samples were studied by means of XRD, SEM, and nitrogen sorption. This new synthesis method allows expanding the pore size from 2.0 nm to 2.5 nm by using ethanol as a solvent during the second synthesis step. The pore size enlargement is accompanied by an improvement of the pore size uniformity and the degree of order of the secondary MCM-48 material. The mechanism by which the pore size expansion occurs is explained in terms of the interactions between the solvent and the hydrophobic core and hydrophilic shell of the micelles formed by the template molecules.