Reverse osmosis membranes for brackish water desalination

摘要

PROBLEM TO BE SOLVED: To provide a reverse osmosis membrane that exhibits excellent desalination performance and permeability required in brine desalination while using a material having chemical resistance (alkali resistance and chlorine resistance).SOLUTION: The reverse osmosis membrane for desalinating brine includes a sulfonated polyarylene ether sulfone polymer that contains components represented by formula [I]. In a proton nuclear magnetic resonance spectrum obtained by measuring water molecules in the membrane using the reverse osmosis membrane in a water-containing state, a relationship between a chemical shift A (ppm) of a spectrum peak top derived from bound water, and a chemical shift B (ppm) of a spectrum peak top derived from bulk water satisfies B-0.42≤AB-0.36. In the formula, X is H or monovalent cationic species, and n is an integer of 10 to 50.