462949 Multi-Scale Modeling of Periodic Mesoporous Silica Materials: Exploring the Role of Silica Oligomers
Our simulations show that the silica oligomers play an important role during the MCM-41 synthesis. A substantial degree of condensation is required to promote the formation of hexagonal array. Those multiply charged silica oligomers are able to bridge adjacent micelles, thus allowing them to overcome their mutual repulsion and form aggregates. They also induce a phase separation that contains a dilute solution and a silica/surfactant-rich mesophase, which leads to MCM-41 formation at a very low surfactant content. In addition, the system with a larger surfactant content shows that liquid crystal templating mechanism is not viable for MCM-41 synthesis. The hexagonal phase found in pure surfactant solution may collapse while the silica monomers are added, and it forms again after a higher degree of condensation of silica is reached. This study provides new insight into the formation mechanism of PMS materials, enabling tailored design of nanoporous materials using computational models.
 Beck, J. S., Vartuli, J. C., Roth, W. J., Leonowicz, M. E., Kresge, C. T., Schmitt, K. D., Chu, C. T. W., Olson, D. H., Sheppard, E. W., McCullen, S. B., Higgins, J. B., and Schlenker, J. L., J. Am. Chem. Soc. 1992, 114, 10834.
 Pérez-Sánchez, G., Chien, S.-C., Gomes, J. R. B., Cordeiro, M. N. D. S., Auerbach, S.M., Monson, P.A., and Jorge, M., Chem. Mater. 2016, 28, 2715.
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