Liquid crystal template, LCT

Zeolitic structures with pore sizes of 2000 to 10000 pm are known as mesoporous solids, and can be formed by a method known as liquid crystal templating (LCT). The combination of a suitable cationic surfactant together with silicate anions form arrays of rod-like surfactant micelles (Figure 3.7) surrounded by a polymeric siliceous framework. On calcination the mesoporous structure is formed. 

Figure 11.12 shows the proposed scheme for the stractural evolution during the synthesis, based in a liquid-crystal templating (LCT) mechanism. Initially, the aqueous acid solution is solubihzed in the cyhndrical reverse micelles forming the reverse hexagonal phase. Nonhydrolyzed TEOS molecules and PDMS chains are mutually soluble and therefore constitute the hydrophobic continuous medium. The hydrolysis is probably driven by interfacial diffusion of the water towards the... 

Assembly of dissolved inorganic species around surfactant arrays via liquid crystal templating (LCT) mechanisms... 

Figure 9.18 Formation of ordered mesoporous MCM-41 silica (liquid crystal templating mechanism (LCT) according to Beck et al. (137). The pathway 1 is liquid crystal-initiated and the pathway 2 is silicate-initiated. (Adapted and reproduced with permission from J. S. Beck et al. J. Am. Chem. Soc. 1992,114,10834. Cop5rright 1992 American Chemical Society.)...

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