TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The first and second polymers may also comprise functional unit(s). The functional unit is hydrophilic, methanol blocking, dimension stabilizer or flexible units. The hydrophilic units are preferably polyvinylpyrrolidone, poly(n-isopropylacrylamide), poly(2-hydroxy-ethyl methacrylates), copolymers of vinylpyrrolidone-vinylimidazole, copolymers of vinylpyrrolidone-dimethylaminoethyl methacrylate, copolymers of vinylpyrrolidone-styrene, copolymers of vinylpyrrolidone-vinylacetate, copolymers of vinylpyrrolidone-vinylacetate-vinyl alcohol, or copolymers of acrylonitrile-isopropylacrylamide. The methanol blocking units are preferably copolymers of vinylpyrrolidone-vinylacetate, copolymers of vinylpyrrolidone-vinylacetate-vinyl alcohol, polyvinylalcohol, polyvinylacetate, copolymers of vinylacetate-vinylalcohol, copolymers of ethylene-vinylacetate, copolymers of vinylpryridine-vinylacetate, copolymers of vinylpyridine-vinylalcohol, or copolymers of vinylpyridine-vinylacetate-vinylalcohol. The dimension stability unit comprises polymer or copolymer containing hydrophobic unit. The hydrophobic unit comprises polystyrene, polysiloxane, or polyvinylidene fluoride. The flexible unit comprises vinylidene fluoride copolymer. The blend membrane also comprises an interpenetrating network (IPN) polymers, an elastomer polymer, or copolymer. The IPN polymer is ultraviolet (UV) initiated, e-beam initiated, gamma-ray initiated, thermal initiated, or chemical initiated IPN polymers. The UV initiated IPN polymer is polyvinyl cinnamate. The membrane comprises (wt.%) UV initiated IPN polymer (0.5-30), and chemical initiated IPN polymer (0.01-25). The chemical initiated IPN polymer is a sol-gel product of tetramethyl orthosilicate (TMOS), tetraethylorthosilicate (TEOS), or combination of aminopropyl terminated polydimethylsiloxane with TMOS and/or TEOS. The elastomeric polymer is polyacrylonitrile, acrylonitrile copolymers, polyvinylidene fluoride, vinylidene fluoride copolymers, polysiloxanes, siloxane copolymers, or polyphosphazenes. The acidic subunits of the first polymer are sulfonic acid, phosphonic acid, or carboxylic acid groups. The acidic subunits of the first polymer are preferably sulfonated polyetherether ketone, sulfonate polyetherether sulfone, sulfonated polyetherimide or polyethersulfone. The acidic subunits of the first polymer are preferably sulfonated polyetherether ketone with 50-200 % sulfonation. The basic subunits of the second polymer are aromatic amines, aliphatic amines, heterocyclic nitrogen containing groups, heterocyclic oxygen containing groups, or heterocyclic sulfur containing groups. The basic subunits of the second polymer are preferably polybenzimidazole, polyvinylimidazole, copolymer of styrene-4-vinylpyridine, copolymer of acrylonitrile-4-vinylpyridine, copolymer of styrene-4-vinylpyridine-acrylic acid, or preferably polyvinylpyridine. The third polymer comprises hydrophilic unit. The block copolymer is styrene-4-vinylpyridine block copolymer, acrylonitrile-4-vinylpyridine block copolymer, or stryrene-4-vinylpyridine-acrylic acid copolymer. The copolymer containing hydrophilic units comprises block copolymers of vinylpyrrolidone-vinylimidazole with 0-80 wt.% styrene content.