SILICA/POROUS HOLLOW FIBER CARBONMOLECULAR SIEVE MEMBRANE FOR HYDROGEN GAS SEPARATION AND PREPARATION METHOD THEREOF

摘要

A siloxane-fluorine contained highly hydrophobic polymer additive for distributing silica on the surface of a silica/porous hollow fiber type carbon molecular sieve membrane for hydrogen gas separation capable of efficiently separating hydrogen gas by improving permeability relative to hydrogen gas in a gas mixture, a method for preparing the additive, a silica/porous hollow fiber type carbon molecular sieve membrane for hydrogen gas separation comprising silica distributed on the surface thereof, and a method for preparing the membrane are provided. A method for preparing a silica/porous hollow fiber type carbon molecular sieve membrane for hydrogen gas separation comprises the steps of: (1) preparing a polymer hollow fiber membrane from a dope solution to which a siloxane-fluorine contained highly hydrophobic polymer additive of a formula 1 is added, wherein part A is a repeating unit formed by urea bonding of MDI and siloxane oligomer, part B is a repeating unit formed by urethane bonding of MDI and fluoroalcohol intermediate, m is 1 to 7, n is 5 to 20, and q is 10 to 35; (2) raising a temperature of the polymer hollow fiber membrane to 400 deg.C at a temperature raising rate of 5 to 10 deg.C/min in an inert atmosphere, and passing the heated polymer hollow fiber membrane through an isothermal process for 10 to 20 minutes; (3) raising a temperature of the polymer hollow fiber membrane to 600 deg.C at a temperature raising rate of 1 to 3 deg.C/min, and passing the heated polymer hollow fiber membrane through an isothermal process for 1 to 2 hours; and (4) lowering a temperature of a polymer hollow fiber membrane stabilized through the isothermal processes to an ordinary temperature at a temperature lowering rate of 1 to 5 deg.C/min to carbonize the polymer hollow fiber membrane.