Patent ID: 8163189

Claim:
A method for producing a nanoporous substrate comprising the steps of: (a) forming a film comprising an amphipathic block copolymer on a substrate, wherein the amphipathic block copolymer is represented by chemical formula 1: wherein A represents a hydrophilic polymer chain, B represents a halogen atom, R 1 represents a hydrogen atom or an alkyl group, “a” represents an integer from 5 to 500, I represents an integer from 4 to 30 and C represents a liquid crystalline mesogen chain; (b) immersing the substrate with the film comprising the amphipathic block copolymer thereon into a solution containing an aqueous etchant for the substrate, wherein the film contains hydrophilic cylinders aligned perpendicularly to the surface of the film, the hydrophilic cylinders have a diameter from 3 to 40 nm and are arranged with less than 60 nm periodicity and wherein the surface of the substrate corresponding to the hydrophilic cylinders is treated with the etchant; and (c) removing the film from the substrate.