Well-ordered spherical mesoporous materials CMI-1 synthesized via an assembly of decaoxyethylene cetyl ether and TMOS

Well-ordered spherical CMI-1 mesoporous materials with a hexagonal arrangement of channels, analogous to MCM-41, have been directly synthesized by variation of the weight percentage of decaoxyethylene cetyl ether [C-16(EO)(10)] in aqueous solution. XRD, TEM, SEM, and nitrogen adsorption-desorption results led us to propose two different synthesis pathways for surfactant concentrations higher and lower than 30 wt %, respectively. For samples obtained with an elevated surfactant concentration (> 30 wt %), in addition to the possible perturbation induced by methanol released in low amount during the hydrolysis of TMOS, other factors such as the interactions of the silica source with hydrophilic chain heads of surfactant molecules should also disturb the preformed hexagonal micelle array, and disordered wormhole mesostructured materials (DWM), analogous to MSU, are obtained. For the synthesis with a C-16(EO)(10) concentration less than 30 wt %, a cooperative mechanism, which involves the polymerization of silica source and the interface interactions between the hydroxyl groups of silica source produced from the hydrolysis of TMOS and hydrophilic chain heads of surfactant molecules which are present in the single rod micelle form, has been evidenced, leading to well-ordered CMI-1 materials with hexagonal arrangement of their channels.