Liquid-crystal templating mechanism

Kresge C T, Leonowicz M E, Roth W J, Vartuli J C and Beck J S 1992 Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism Nature 359 710-12... 

Kokufuta, E Jinbo, E, A Hydrogel Capable of Facilitating Polymer Diffusion through the Gel Porosity and Its Application in Enzyme Immobilization, Macromolecules 25, 3549, 1992. Kresge, CT Leonowicz, ME Roth, WJ Vartuli, JC Beck, JS, Ordered Mesoporous Molecular Sieves Synthesized by a Liquid-Crystal Template Mechanism, Nature 359, 710, 1992. 

Fig. 77. Schematic drawing of the liquid-crystal templating mechanism. Hexagonal arrays of cylindrical micelles form (possibly mediated by the presence of silicate ions), with the polar groups of the surfactants (light grey) to the outside. Silicate species (dark grey) then occupy the spaces between the cylinders. The final calcination step burns off the original organic material, leaving hollow cylinders of inorganic material [473]...

Figure 3.4 Formation of mesoporous materials by structure-directing agents (a) true liquid-crystal template mechanism, (b) cooperative liquid-crystal template mechanism.

Kresge, C. T., Leonowicz, M. E., Roth, W. J., Vartuli, J. C. and Beck, J. S. Ordered mesoporous molecular-sieves synthesized hy a liquid-crystal template mechanism, Nature, 1992, 359, 710-712. 

Different mechanisms for the interactions between the silicate precursors and the organic template as well as the liquid crystal templating mechanisms have been discussed (Ying, Mehnert, and Wong, 1999 Tanev and Pinnavaia,... 

It was considered by the Mobil scientists that the mesoporous structure was formed as a result of a liquid crystal templating mechanism (see Figure 12.5) since the... 

Figure 12.5. Schematic representation of the formation of MCM-41 by die liquid crystal templating mechanism first proposed by Kresge er al. (1992). (a) Hexagonal array of cylindrical micelles (b) the same, with silicate species between the cylinders and (c) hollow cylinders of MCM-41 after thermal elimination of organic material. 

Figure 17 Formation of 2D-hexagonal mesoporous mixed metal oxides by liquid crystal templating mechanism [134,135]...

Figure 9. Schematic representation of formation of MCM-41 by a liquid crystal templating mechanism (1) liquid crystal phase initiated and (2) silicate anion initiated.

C.T. Kresge, M.E. Leonowicz, W.J. Roth, J.C. Vartuli, and J.S. Beck, Ordered Mesoporous Molecular Sieves Synthesized by a Liquid-crystal Template Mechanism. Nature (London),... 

The generalized liquid-crystal-template mechanism focuses on the interaction between surfactant molecules and inorganic species. Surfactant molecules assemble with inorganic species to form the liquid-crystal-like mesophase. The three main interactions between surfactant and inorganic species are (i) electrostatic interaction (the charge-density match plays the key role), (2) hydrogen bond, in particularly for those neutral templates, and (iii) covalent bond. 

Fig. 5. Schematic representation of the liquid crystal templating mechanism of the ordered mesoporous materials - original with added modifications...

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