Water-treatment separating membrane of high flux having good chlorine resistance
A water-treatment separating membrane includes a polyamide active layer formed on a porous support. When the polyamide active layer is dyed using a 5% aqueous solution of Rhodamine B, at least a curve pattern formed by connecting two or more arcs is formed in at least a partial area of the polyamide active layer.
1. A water-treatment separating membrane comprising:
a polyamide active layer formed on a porous support;
wherein the polyamide active layer is formed by dropping droplets of an organic solution including an acyl halide compound on an aqueous amine solution layer and includes a center portion in which a degree of an interfacial polymerization of the organic solution is high and a critical area in which the degree of the interfacial polymerization of the organic solution is low,
wherein the volume of the organic solution per droplet is from 0.001 ml to 5 ml,
wherein at least a curve pattern formed by connecting two or more arcs is formed in at least a partial area of the polyamide active layer, and the curve pattern can be made visible when the polyamide active layer is dyed using a 5% aqueous solution of Rhodamine B,
wherein at least one of the two or more arcs is a portion of a closed circular curve,
wherein a major diameter of the closed circular curve is from 5 mm to 100 mm, and
wherein an arithmetic mean roughness (Ra) of a surface of the polyamide active layer is from 60 nm to 100 nm.
2. The water-treatment separating membrane of claim 1 , wherein the curve pattern has a form obtained by connecting both end points of each arc with respective curve portions of other arcs.
3. The water-treatment separating membrane of claim 1 , wherein the curve pattern has a form obtained by arranging the two or more arcs in a row, and connecting end points of the arcs to connect adjacent arcs.
4. The water-treatment separating membrane of claim 2 , wherein the two or more arcs are arranged convexly in the same direction.
5. The water-treatment separating membrane of claim 3 , wherein the curve patterns are repeatedly formed in a direction perpendicular with respect to an arranging direction of the two or more arcs.
6. The water-treatment separating membrane of claim 1 , wherein the closed circular curve is provided in plural and arranged irregularly or regularly.
7. The water-treatment separating membrane of claim 1 , wherein a distance between centers of the circular closed curves is from 1 mm to 50 mm.
8. The water-treatment separating membrane of claim 1 , wherein a thickness of the curve pattern is from 4% to 25% of a major diameter of the circular closed curve.
9. The water-treatment separating membrane of claim 1 , wherein the curve pattern is formed in a critical area in which a degree of polyamide polymerization is low.
10. A water-treatment module comprising at least one water-treatment separating membrane of claim 1 .
11. A water-treatment apparatus comprising at least one water-treatment module of claim 10 .
12. The water-treatment separating membrane of claim 3 , wherein the two or more arcs are arranged convexly in the same direction.