SYNTHESIS AND CHARACTERIZATION OF LIQUID-CRYSTAL TYPE STATIONARY PHASES ON A SILICA HYDRIDE SURFACE

Two liquid crystal materials, 4-methoxyphenyl-4-allyloxybenzoate and c holesteryl-10-undecenoate, containing terminal olefin groups are bonde d to a silica hydride surface via a metal complex catalyzed hydrosilat ion reaction. Bonding is confirmed by DRIFT, carbon-13 CP-MAS NMR and DSC. The effects of different catalysts, reaction temperature, catalys t to olefin ratio, and reaction time were studied to maximize the surf ace coverage. Chromatographic studies indicate that these bonded mater ials behave similarly to liquid crystal phases prepared by organosilan ization. The hydrosilation method offers the possibility of bonding a wider variety of liquid crystal moieties in order to utilize the uniqu e separation properties of these materials.