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Synthesis of lamellar aluminophosphates via the supramolecular templating mechanism

1997; Elsevier BV; Linguagem: Inglês

10.1016/s0167-2991(97)80536-8

2542-6613

Abdelhamid Sayari,

Advanced NMR Techniques and Applications

The liquid-crystal templating approach for the synthesis of mesostructured materials was extended to aluminophosphates. Long chain primary and tertiary amines were used as templetes. The molar gel composition was varied in a systematic manner over a wide range. Samples were thoroughly characterized using XRD, TEM, TGA, and 31 P, 27 Al, 15 N and 13 C solid state NMR. Several lamellar phases with d 001 distances in the 2 to 4 nm range were obtained. However, no three dimensional structures were detected. The gel composition was found to have a strong effect on the connectivity of aluminum and phosphorus in the final “crystalline” phase, as well as on their d 001 distances. TEM showed that some samplex exhibit extended areas with unique structural features. They consisted of coaxial cylinders of alternating inorganic aluminophosphate material and organic surfactant bilayers, all wrapped around a central rodlike micelle. Such coaxial cylinders had an overall diameter of ca. 150 nm. They were aggregated into a hexagonal-like structure.