Forward osmosis membrane for seawater desalination and method for preparing the same

摘要

A forward osmosis membrane for seawater desalination and a method for preparing the same. The forward osmosis membrane has a composite membrane structure including a nonwoven fabric layer, a hydrophilic polymer layer, and a polyamide layer. The hydrophilic polymer layer formed on the nonwoven fabric layer facilitates an inflow of water from the feed water to the draw solution to enhance flux and realize high water permeability in the direction of osmosis. The polyamide layer not only secures contamination resistance and chemical resistance but also minimizes the back diffusion of salts of the draw solution in the direction of reverse osmosis. Hence, the forward osmosis membrane of the present invention is greatly useful for desalination of high-concentration seawater.

主权项

1. A forward osmosis membrane for seawater desalination in a forward osmosis mode, said forward osmosis membrane having a composite membrane structure of sequentially laminated layers comprising:
a hydrophilic polymer layer having finger-like pores; and a polyamide layer; wherein the forward osmosis membrane satisfies both (i) a back diffusion of salts from a draw solution not more than 0.375 (μS/cm)/min·cm2 and (ii) a flux of 3 to 30 GFD as measured using a feed water and a 2M NaCl draw solution in the forward osmosis mode; wherein the hydrophilic polymer layer contains 10 to 25 wt % content of a hydrophilic polymer including any one selected from the group consisting of hydrophilic polyacrylonitrile, polyacrylonitrile-vinylacetate copolymer (P-CO-PAN), and polyacrylonitrile-acrylic ester copolymer (CO-PAN); or the hydrophilic polymer containing 0.1 to 10 wt % of a sulfonated polysulfone-based polymer represented by formula 1 in combination with a polysulfone-based polymer;wherein A is any one functional group selected from:B is any one functional group selected from: m/(n+m) is 0.2 to 0.7; and x is 50 to 2,300.