GAS-SEPARATION COMPOSITE MEMBRANE AND METHOD FOR MANUFACTURE THEREOF Russian patent published in 2003 - IPC

FIELD: gas separation methods. SUBSTANCE: invention relates to technology of manufacturing gas-separation composite membranes for use in gas separation and gas concentration processes in chemical, petrochemical, and medical industries. Membrane consists of hydrophobic porous flexible substrate made in the form of ultra- or microfiltration fluorocarbon membrane and gas-separation diffusion layer joined with the substrate in the molding step. Substrate is characterized by pore size Dn, which can be found from relationship: Dn = (0.05-0.9)Dm wherein Dm is size of micelles in working solution of block copolymer. Diffusion layer comprises, more particularly, trimethylphenyl-polysiloxane or dimethyldiphenylpolysiloxane/diphenyl-polysilsesquioxane block copolymers including structure-1 and -2 blocks. Manufacture of membrane: working solution in the form of micellar system is prepared by spontaneous dispersing of above-named block copolymers involving simultaneous mixing of block copolymer with solvent and non-solvent at weight ratio (2.0-8.0): (5.0-40.0):(30.0-90.0), respectively. Alternatively, block copolymer is mixed with freon-11 (fluorotrichloromethane) at weight ratio 1:(9-45) to form working solution, which is molded using dry technique into gas-selective layer on above-indicated hydrophobic porous flexible substrate. EFFECT: enhanced gas-selective properties, increased strength and operation reliability without loss in productivity. 5 cl, 1 dwg, 3 tbl, 16 ex