Water-treatment separation membrane comprising ionic exchangeable polymer layer and method for forming same
The present invention relates to a water treatment membrane including a support; and a polymer layer including a copolymer containing a hydrophobic repeating unit and a hydrophilic repeating unit including an ion exchange functional group on the support, wherein the polymer layer has ion exchange capacity (IEC) of 0.02 meq/g to 2.4 meq/g, and to a water treatment module, which have excellent salt rejection and permeate flow properties.
1. A water treatment membrane comprising:
a support; and
a polymer layer on the support, the polymer layer including a copolymer containing a hydrophobic repeating unit and a hydrophilic repeating unit including an ion exchange functional group,
wherein:
the polymer layer has ion exchange capacity (IEC) of 0.02 meq/g to 2.4 meq/g;
the hydrophilic repeating unit has the following Chemical Formula 3:
wherein:
G in each repeating unit is a functional group selected from the group consisting of:
R 5 has an ion exchange functional group that is —SO 3 M, —CO 3 M or —PO 3 M where M is H, Na or K; and
the hydrophobic repeating unit has the following Chemical Formula 4:
wherein:
H in each repeating unit is a functional group selected from the group consisting of:
and
* in Chemical Formula 3 and 4 is a site at which repeating units are connected and no separate atoms or molecules are present at the site.
2. The water treatment membrane of claim 1 , wherein a molar ratio of the hydrophilic repeating unit and the hydrophobic repeating unit is 1:9 to 1:1.
3. The water treatment membrane of claim 1 , wherein the copolymer has a weight average molecular weight of 30,000 to 1,000,000.
4. The water treatment membrane of claim 1 , wherein the polymer layer has a thickness of 0.1 μm to 200 μm.
5. The water treatment membrane of claim 1 , which has initial salt rejection of 97% or greater, and initial permeate flow of 38 to 48 gallon/ft 2 ·day when a sodium chloride (NaCl) solution having a concentration of 32,000 ppm passes therethrough under a pressure of 800 psi.
6. The water treatment membrane of claim 1 comprising one or more active layers on the polymer layer.
7. The water treatment membrane of claim 1 , which is a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane or a reverse osmosis membrane.
8. A water treatment module comprising the water treatment membrane of claim 1 .
9. A method for manufacturing a water treatment membrane comprising:
coating a support using a solution including a copolymer containing a hydrophobic repeating unit and a hydrophilic repeating unit including an ion exchange functional group, and a solvent; and
carrying out phase transition by immersing the coated support in a non-solvent,
wherein:
the copolymer is a copolymer containing a hydrophobic repeating unit and a hydrophilic repeating unit including an ion exchange functional group,
wherein:
G is any one or more functional groups selected from the group consisting of the following functional groups:
R 5 has an ion exchange functional group that is —SO 3 M, —CO 3 M or —PO 3 M where M is H, Na or K; and
the hydrophobic repeating unit has the following Chemical Formula 4:
wherein:
H is any one or more functional groups selected from the group consisting of the following functional groups:
and
* in Chemical Formula 3 and 4 is a site at which repeating units are connected and no separate atoms or molecules are present at the site.
10. The method for manufacturing a water treatment membrane of claim 9 , wherein the non-solvent is selected from the group consisting of distilled water that is distilled once, distilled water that is distilled three times, alcohols, and a mixture thereof.
11. The water treatment membrane of claim 1 , wherein:
the hydrophilic repeating unit is:
and
the hydrophobic repeating unit is:
12. The method for manufacturing a water treatment membrane of claim 9 , wherein:
the hydrophilic repeating unit is:
and
the hydrophobic repeating unit is: