METHOD OF PREPARING COMPOSITE MEMBRANE MODULE
A method of preparing a composite membrane module includes preparing a single membrane module to which a hollow fiber support layer is potted; and forming an active layer on a surface of the hollow fiber support layer through interfacial polymerization by bringing a surface of the hollow fiber support layer into contact with a first solution comprising an amine and a second solution comprising an acyl halide (in that order). The method can form an active layer having a uniform thickness and good processability. A composite hollow fiber membrane module prepared by the method exhibits a good salt rejection rate.
1 . A method of preparing a composite membrane module, comprising:
preparing a single membrane module comprising a hollow fiber support layer potted in the single membrane module; and
forming an active layer on a surface of the hollow fiber support layer through interfacial polymerization by bringing the surface of the hollow fiber support layer into contact with a first solution comprising an amine and then bringing the surface of the hollow fiber support layer into contact with a second solution comprising an acyl halide.
2 . The method according to claim 1 , wherein the single membrane module comprises:
a plurality of hollow fiber support layers, each of the plurality of hollow fiber support layers being potted at two ends thereof; and
a housing accommodating the plurality of hollow fiber support layers therein.
3 . The method according to claim 1 , wherein the hollow fiber support layer is prepared by:
forming hollow fibers by spinning a polymer solution comprising a polysulfone resin, an organic solvent, and a pore agent;
forming external pores in the hollow fibers by exposing the hollow fibers to air;
forming internal pores in the hollow fibers by dipping the hollow fibers having the external pores into a non-solvent; and
coagulating the hollow fibers.
4 . The method according to claim 3 , wherein the polysulfone resin comprises polysulfone, polyether sulfone, or a mixture thereof.
5 . The method according to claim 3 , wherein the organic solvent comprises N,N-dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethylacetamide, or a mixture thereof.
6 . The method according to claim 3 , wherein the pore agent comprises 2-ethoxyethanol, propionic acid, acetic acid, t-amyl alcohol, 2-methoxyethanol, methanol, ethanol, butanol, isopropyl alcohol, polyethylene glycol, silica, polyvinylpyrrolidone or a mixture thereof.
7 . The method according to claim 3 , wherein the non-solvent comprises water, methanol, ethanol, isopropanol, or a mixture thereof.
8 . The method according to claim 1 , wherein the hollow fiber support layer has an inner diameter of about 0.1 mm to about 3.0 mm, and a thickness of about 10 μm to about 500 μm.
9 . The method according to claim 1 , wherein the hollow fiber support layer is a porous ultrafiltration membrane having a pore size of about 10 nm to about 100 μm.
10 . The method according to claim 1 , wherein the active layer has a pore size of about 0.001 μm to about 0.0001 μm.
11 . The method according to claim 1 , wherein the first solution comprises a polyamine and water, and the polyamine is present in the first solution in an amount of about 0.1 wt % to about 15 wt %, based on 100 wt % of the first solution.
12 . The method according to claim 11 , wherein the polyamine comprises phenylenediamine, cyclohexanediamine, piperazine, or a mixture thereof.
13 . The method according to claim 1 , wherein the second solution comprises a polyfunctional acyl halide and an organic solvent, and the polyfunctional acyl halide is present in the second solution in an amount of about 0.01 wt % to about 5 wt %, based on 100 wt % of the second solution.
14 . The method according to claim 13 , wherein the polyfunctional acyl halide comprises trimesoyl chloride, isophthaloyl chloride, terephthaloyl chloride, 1,3,5-cyclohexane tricarbonyl chloride, 1,2,3,4-cyclohexane tetracarbonyl chloride, 1,3,5-benzenetricarbonyl trichloride or a mixture thereof.
15 . The method according to claim 1 , wherein the composite membrane module is a pressurizing module.
16 . A composite membrane module prepared according to the method of claim 1 , and having a salt rejection rate of about 90% to about 99%.