Solid-state NMR studies of the organic template in mesostructured aluminophosphates

Solid-state NMR has been used to monitor the conformation and mobility of the organic surfactant occluded in aluminophosphate-based mesocomposites with hexagonal (Hex) and lamellar (L) structures. At ambient temperature hexagonal aluminophosphates (AlPO's) show predominant disordered gauche conformation of the aliphatic chains. On the other hand, in the mesolamellar L1 and L3 the surfactant is in the ordered all-trans conformation, while in L2 it is in the gauche conformation despite the well-defined mesolamellar structure. The temperature of the all-trans⇔gauche transition increases in the series: Hex-1, Hex-2<L2