Abstract: A method of forming a nanoporous membrane includes preparing a solution of a gemini Imidazolium Lyotropic Liquid Crystal (LLC) monomer, a polar low-volatility organic solvent, and a radical photo-initiator in a volatile organic solvent; solvent-casting the solution onto a porous material, evaporating the volatile organic solvent; heating such that the gemini imidazolium monomer forms a Q-phase material and photopolymerizing the imidazolium monomer by exposing the radical photo-initiator to UV light; and exchanging the polar low-volatility organic solvent. Also disclosed is a membrane composed of polymerized gemini imidazolium LLC monomers, and a thin-film composite membrane having the Q-phase material supported on a porous supporting membrane.

Abstract: The invention provides composite nanofiltration membranes with a lyotropic liquid crystal (LLC) polymer composition embedded in or forming a layer on a porous support. The LLC membranes are prepared from LLC monomers which form a bicontinuous cubic (QI) phase. The arrangement, size, and chemical properties of the pores can be tailored on the molecular level. The composite membranes of the invention are useful for separation processes involving aqueous and nonaqueous solutions as well as gases. Methods for making and using the composite nanofiltration membranes of the invention are also provided.