Inorganic nanostructures from lyotropic liquid crystal phases

Abstract

Lyotropic liquid crystalline phases are exploited as templates for the synthesis of inorganic nanostructures. In this approach the aggregates of non-ionic amphiphiles in water function as confining media, i.e. the polymerisation of a water-soluble precursor takes place in their aqueous domains. This approach to nanostructure design has considerable advantages over previous routes towards mesoporous ceramic oxides. (i) The nanostructure of the solid can be predicted a priori, (ii) this approach allows the use of non-ionic surfactants as templates and (iii) the progress of the formation can be monitored by various analytical techniques. The approach is tolerant to the introduction of metals into the silica framework, as is demonstrated using aluminium silicate as a representative example. The synthesis and a new way of monitoring the temporal evolution of the inorganic nanostructure using deuterium NMR spectroscopy are described. The results show that the lyotropic liquid crystal phase acts as a template. Further, a novel approach to studying sorption properties allows a comparison with other meso- and microporous materials.