Synthesis of lamellar mesostructures with nonamphiphilic mesogens as templates

Magnesium- and zinc-based lamellar mesostructures were synthesized with nonamphiphilic mesogens as templates. The templates used were disodium chromoglycate (DSCG) and flufenamic acid (FA) which are known to exhibit lyotropic liquid-crystalline phases in aqueous solutions. Evidence for the lamellar structure was obtained from the X-ray diffraction patterns and transmission electron micrographs. The interlayer spacings in the materials prepared with DSCG and FA, 30 and 24 Angstrom, respectively, were large compared to the molecular dimensions of the templates, suggesting the existence of a bilayer arrangement of the templates between the inorganic walls. The presence of intact template molecules within the layers was confirmed by chemical analysis, TGA, IR, and NMR measurements. Interactions between the template molecules and the inorganic layer were evident through the increase in their decomposition temperatures as compared to the pure template and by the slight weakening of the C=O bond as determined by the IR measurements. The synthesis of lamellar mesostructures with nonamphiphilic mesogens broadens the scope of the so-called ''liquid-crystal template mechanism'' in the sense that it is not limited to amphiphilic molecules but applies also to other molecules which can form large molecular assemblies in solutions.