Lamellar aluminophosphate phase

Mesostructured aluminophosphate / surfactant composite materials were prepared from aqueous and alcoholic systems. Syntheses in ethanol or methanol, respectively, lead to mixtures of two nanostructured phases. One of these consists of hexagonally arranged rod-like assemblies of the surfactant molecules with the head groups located in the centres, encapsulating the inorganic aluminophosphate the other is lamellar. The syntheses were monitored by in-situ temperature- and time-resolved small angle X-ray scattering (SAXS). 

Figure 2. Powder XRD diagrams of mesostructured aluminophosphate / surfactant composite materials prepared in ethanol at various temperatures (a) 60°C, (b) 40°C, (c) 25°C, (d) 10°C. A hexagonal phase is indexed "4" corresponds to a phase with presumably lamellar structure.

In conclusion, the synthesis of mesostructured aluminophosphate / surfactant materials in alcoholic systems yields a mixture of an inverse hexagonal and a lamellar phase, the latter of which is more stable, as its formation is relatively favoured by higher temperatures and/or longer reaction times. The synthesis is highly cooperative the surfactant / alcohol systems without the inorganic species do not show any lyotropic behaviour. 

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