Reverse osmosis membrane including ultra-hydrophilic passivation layer and method of manufacturing the same
A reverse osmosis separation membrane includes a porous support, a separation active layer formed on the supporting layer, and a ultra hydrophilic layer formed on the separation active layer. The ultra-hydrophilic layer includes a complex metal oxide including at least one metal element selected from the group consisting of Ti(IV), Zr(IV), Sn(IV) and Al(III), and Si, and an organic compound containing a hydrophilic group making a physical or chemical bond with Ti(IV), Zr(IV), Sn(IV) or Al(III) among the complex metal oxide. A method of manufacturing the reverse osmosis separation membrane also is provided. A reverse osmosis membrane including a single coating layer and having an improved durability, chlorine-resistance and antifouling properties may be provided.
1. A reverse osmosis separation membrane, comprising a porous support, a separation active layer formed on the supporting layer, and a ultra hydrophilic layer formed on the separation active layer,
the ultra-hydrophilic layer comprising a complex metal oxide including at least one metal element selected from the group consisting of Ti(IV), Zr(IV), Sn(IV) and Al (III), and Si; and an organic compound containing a hydrophilic group making a physical or chemical bond with Ti(IV), Zr(IV), Sn(IV) or Al(III) among the complex metal oxide.
2. The reverse osmosis separation membrane of claim 1 , wherein the complex metal oxide has a meso-porous structure.
3. The reverse osmosis separation membrane of claim 1 , wherein the complex metal oxide has a hollow tube type meso-porous structure.
4. The reverse osmosis separation membrane of claim 3 , wherein the hollow tube type meso-porous structure includes an organic compound containing a hydrophilic group through a physical or chemical bond.
5. The reverse osmosis separation membrane of claim 1 , wherein the ultra-hydrophilic layer includes a compound having a structure represented by following Chemical Formula 6.
in Chemical Formula 6.
M represents Ti(IV), Zr(IV), Sn(IV) or Al(III),
R 6 represents hydrogen, a C 1-20 alkyl group, C n H 2n —OH, or C n H 2n —CHCH 2 O (in which, n represents an integer of 1 to 20), and
R 7 represents a functional group originated from an organic compound containing the hydrophilic group.
6. The reverse osmosis separation membrane of claim 1 , wherein the hydrophilic group of the organic compound containing the hydrophilic compound is at least one selected from the group consisting of a sulfonate salt, sulfuric acid, a carboxylate salt, carboxylic acid, a phosphate salt, phosphoric acid and a hydroxyl group (OH).
7. The reverse osmosis separation membrane of claim 1 , wherein the organic compound containing the hydrophilic group includes at least one functional group selected from the group consisting of a hydroxyl group (OH), an amine group and a phosphate, the functional group possibly making a physical or chemical bond with Ti(IV), Zr(IV), Sn(IV) or Al(III) among the complex metal oxide.
8. The reverse osmosis separation membrane of claim 1 , wherein the organic compound containing the hydrophilic group is a chelating agent possibly making a coordination bond with Ti(IV), Zr(IV), Sn(IV) or Al(III) among the complex metal oxide.
9. The reverse osmosis separation membrane of claim 1 , wherein the organic compound containing the hydrophilic group is at least one selected from the group consisting of disodium 1,2-dihydroxybenzene-3,5-disulfonate, sodium 1,2-dihydroxy-3-sulfonate, sodium 1,2-dihydroxy-4-sulfonate, sodium 1,2-dihydroxy-5-sulfonate, disodium 1,2-dihydroxy-4-chlorobenzene-3,5-disulfonate, disodium 1,2-dihydroxy-6-chlorobenzene-3,5-disulfonate, 1,2-dihydroxybenzene-3.5-disulfonic acid, 1,2-dihydroxy-3-sulfonic acid. 1,2-dihydroxy-4-sulfonic acid, 1,2-dihydroxy-5-sulfonic acid, 1,2-dihydroxy-4-chlorobenzene-3,5-disulfonic acid, 1,2-dihydroxy-6-chlorobenzene-3,5-disulfonic acid, disodium 1,2-dihydroxybenzene-3,5-dicarboxylate, sodium 1,2-dihydroxy-3-carboxylate, sodium 1,2-dihydroxy-4-carboxylate, sodium 1,2-dihydroxy-5-carboxylate, disodium 1,2-dihydroxy-4-chlorobenzene-3,5-dicarboxylate, disodium 1,2-dihydroxy-6-chlorobenzene-3,5-dicarboxylate, 1,2-dihydroxybenzene-3,5-dicarboxylic acid, 1,2-dihydroxy-3-carboxylic acid, 1,2-dihydroxy-4-carboxylic acid, 1,2-dihydroxy-5-carboxylic acid, 1.2-dihydroxy-4-chlorobenzene-3,5-dicarboxylic acid, 1.2-dihydroxy-6-chlorobenzene-3,5-dicarboxylic acid, disodium 1,2-dihydroxybenzene-3,5-diphosphate, sodium 1,2-dihydroxy-3-phosphate, sodium 1,2-dihydroxy-4-phosphate, sodium 1,2-dihydroxy-5-phosphate, disodium 1,2-dihydroxy-4-chlorobenzene-3,5-diphosphate, disodium 1,2-dihydroxy-6-chlorobenzene-3,5-diphosphate, 1,2-dihydroxybenzene-3,5-diphosphoric acid, 1,2-dihydroxybenzene-3-phosphoric acid, 1,2-dihydroxybenzene-4-phosphoric acid, 1,2-dihydroxybenzene-5-phosphoric acid, 1,2-dihydroxy-4-chlorobenzene-3,5-diphosphoric acid, 1,2-dihydroxy-6-chlorobenzene-3,5-diphosphoric acid, dihexadecyl phosphate, monododecyl phosphate, and nafion (tetrafluoroethylene-perfluoro-3,6-dioxa-4-methyl-7-octenesulfonic acid copolymer).
10. The reverse osmosis separation membrane of claim 2 , wherein the complex metal oxide having the meso-porous structure is prepared by a polymerization reaction of a precursor including at least one element selected from the group consisting of Si, Ti(IV), Zr(IV), Sn(IV) and Al(III) in the presence of a solvent and a surfactant.
11. The reverse osmosis separation membrane of claim 10 , wherein the solvent is at least one selected from the group consisting of ethanol, water, isopropyl alcohol, methanol and ethyl acetate.
12. The reverse osmosis separation membrane of claim 10 , wherein the surfactant is a nonionic surfactant represented by following Chemical Formula 3 or an ionic surfactant represented by following Chemical Formula 4,
EO X PO Y EO X [Chemical Formula 3]
in Chemical Formula 3, x=5-40%, y=90-20%, 2x+y=100%, EO represents ethylene oxide, and PO represents propylene oxide,
(C n H 2n+1 )(CH 3 ) 3 NX 1 [Chemical Formula 4]
in Chemical Formula 4, n=12 to 18, and X 1 =Cl or Br.
13. The reverse osmosis separation membrane of claim 1 , wherein the ultra-hydrophilic layer further comprises a silane coupling agent.
14. The reverse osmosis separation membrane of claim 1 , wherein the ultra-hydrophilic layer further comprises a multi-functional organic material represented by following Chemical Formula 5,
R 3 (EO) k R 4 [Chemical Formula 5]
in Chemical Formula 5, EO represents ethylene oxide, k represents an integer of 3 to 400, R 3 is selected from the group consisting of OH, (meth)acrylate having C 1 to C 15 , di(meth)acrylate having C 1 to C 15 , tri(meth)acrylate having C 1 to C 15 , and vinyl having C 1 to C 15 , and R 4 is selected from the group consisting of hydrogen, (meth)acrylate having C 1 to C 3 , and vinyl having C 1 to C 3 .