Towards a better understanding on the mechanism of mesoporous formation via an assembly of C_n(EO)_m and TMOS

摘要

The present work deals with a systematic study of mesoporous materials synthesis. A series of polyoxyethylene alkyl ether surfactants such as C_(13)(EO)_n (n = 6, 12, 18), C_(16)(EO)_(10), C_(18)(EO)_(10) have been used. It is revealed that the surfactant conformation changed with the heating temperature. Indeed, at higher temperatures, a more extended molecular conformation can be obtained, which leads to materials with larger pore sizes. We have also shown that the interaction between template and silica disturbs the hexagonal array of micelles in solution leading to the formation of DWM-1 or DWM-2 compounds for concentrated micellar solution. We have also correlated the structural characteristics of the recovered mesoporous molecular sieves with the V_H/V_L ratio of the template.