Utilizing mixed surfactants for simultaneous pore templating and active site formation in metal oxides
Self-assembled nonionic alkyl glycoside surfactants are of interest for creating functional adsorption and catalytic sites at the surface of mesoporous metal oxides, but they typically impart poor long-range order when used as pore templates. Improved order and control over the functional site density may be achieved by mixing them with a cationic surfactant. To confirm this hypothesis, we investigate the lyotropic liquid crystalline (LLC) phase behavior of aqueous solutions of the functional nonionic surfactant n-dodecyl β-D-maltoside (C12G2) and cationic cetyltrimethylammonium bromide (C16TAB). A ternary phase diagram of the C16TAB-C12G2-water system is developed at 50 °C. By replacing the volume of water in the phase diagram with an equivalent volume of silica, ordered mesoporous materials are prepared by nanocasting with variable C12G2/C16TAB ratios. Metal oxide mesophases can almost always be predicted from the ternary phase diagram, except that silica prepared with high C12G2/C16TAB ratios are very weakly ordered, perhaps due to differences in hydrogen bonding or rate of assembly
Link
http://archive.uky.edu/bitstream/10225/1010/Dissertation_of_Mohammed_Rahman.pdf
Link
http://archive.uky.edu/bitstream/10225/1010/Dissertation_of_Mohammed_Rahman.pdf
