Solubilization of oil in silicate-surfactant mesostructures

The solubilization of n-hexane and toluene by silicate-surfactant hexagonal mesophases has been studied by time-resolved in situ synchrotron small-angle X-ray scattering. It is suggested that the extent of solubilization is mainly governed by the oil solubility in the continuous phase. The availability of the oil will largely influence the phase behavior and the long-range order of the silicatropic mesophase. While the addition of n-hexane to the synthesis results in a loss of order, a substantial amount of toluene can be solubilized without affecting the long-range order. Many of the observed effects can be rationalized based on time-dependent changes in the properties of the system due to silicate hydrolysis and condensation reactions, in addition to the water solubility of the solubilizate. The results are compared with those obtained for corresponding systems in the absence of silica.