Patent ID: 8785111

Claim:
A method for the preparation of a nanoporous material of a polymer matrix which has a porosity of 0.1-90%(v/v) and an initial water absorption (%(w/w)) obtained after steps (a) and (b), but before irradiation in step (c), such that the ratio between said initial water absorption (%(w/w)) and said porosity (%(v/v)) is at the most 0.05, said matrix at least in part being rendered more hydrophilic so that said part of said polymer matrix has a final water absorption (%(w/w)) after step (c) such that the ratio between said final water absorption (%(w/w)) and said porosity (%(v/v)) is at least 0.05, the method comprising the steps of: (a) preparing a precursor material comprising at least one polymeric component and having a first phase or micro phase and a second phase or micro-phase, wherein at least one polymeric component is a block-copolymer; (b) removal of at least a part of the first phase or micro-phase of the precursor material prepared in step (a) effected by means of chemical etching, photo-chemical etching, cleaving, extraction, or evaporation, or is combination of these, so as to leave behind a nanoporous material of the polymer matrix, wherein the pores of said nanoporous material have an average diameter in the range of 1.0-100 nm, and wherein the periodicity of the pores is in the range of 1.0-100 nm; (c) irradiating at least a part of said nanoporous material through a mask with light of a wave length of in the range of 300-400 nm in the presence of oxygen and/or ozone, wherein the mask provides a micrometer-scale pattern of hydrophilic surface sections in the matrix of the hydrophobic material.