Synthesis and characterization of two novel mesolamellar aluminophosphates

Two new mesolamellar aluminophosphates, designated L1 and L2, have been synthesized by supramolecular templating from aqueous solutions containing a cationic surfactant and tetraalkylammonium hydroxide. The structure, morphology, and properties of the products have been examined by XRD, SEM, solid-state NMR, thermogravimetry and FTIR and optimal synthesis conditions have been established. Although the compositions of the starting mixtures for the synthesis of L1 and L2 are similar, the structures of the two materials are different. In L2 phosphorus is coordinated to four AlO₄ tetrahedra; this is the most significant difference between the two products, responsible for the higher thermal stability of L2. The synthesis of L2 requires higher temperatures than that of L1.