(82d) Atomistic Molecular Dynamics Simulation of the Self-Assembly of (S)-(1-Tetradecylcarbamoyl-2-phyenylethyl)-Dimethylethylammonium Bromide Surfactants

A three-dimensional hexagonal mesoporous silica, IBN-9, with a tri-continuous pore structure has recently been synthesized¹. Predicted mathematically, this tri-continuous mesostructure is the first one to be observed in real materials. The synthesis of IBN-9 involved the co-assembly of tetraethoxysilane and a specifically designed novel cationic surfactant, (S)-(1-tetradecylcarbamoyl-2-phyenylethyl)-dimethylethylammonium bromide (2), in aqueous solution. To better understand the mechanism of the early stage of this synthesis, we employ atomistic molecular dynamics to simulate the self-assembly of (2) surfactants in aqueous medium. The influence of the surfactant head group size on the mesostructures is studied by comparing (2) with hexadecyltrimethylammonium bromide (CTAB).

1. Han, Y. et. al. A Tri-continuous mesoporous material with a silica pore wall following a hexagonal minimal surface. Nature Chemistry, 1, 123-127 (2009)