The gallophosphate molecular sieve cloverite as a host for liquid crystals

Abstract The gallophosphate cloverite has been investigated because of its applicability to act as a host for larger molecules. 4- n -pentyl-4′-cyanobiphenyl (5CB) and 4- n -octyl-4′-cyanobiphenyl (8CB) liquid crystals were used as guest molecules. The results show that the adsorption of liquid crystals from the gas phase proceeds without destruction of the cloverite structure. The typical phase properties of the liquid crystals remain unchanged after adsorption on cloverite: however, they appear with lower intensity in the DSC curve. A new smectic phase seems to be formed inside the cloverite pore system. FTIR measurements show the interaction of 5CB with the Lewis and Bronsted acid sites of cloverite. Desorption of liquid crystals out of the pore system proceeds slowly under liberation of the POH groups of the lattice. In summary, the results show that the gallophosphate cloverite is a suitable host for large molecules.