▎ 摘　　要

NOVELTY - Polymer solution comprises polyaryl ether sulfone block polymer (I), good solvent, poor solvent and additive. USE - Polymer solution used for preparing nanofiltration membrane in water treatment (all claimed), and also in high-temperature separation, desalination, solvent separation, and material separation. ADVANTAGE - The polyarylethersulfone block polymer has good solubility, thermal stability, mechanical property and chemical stability, and utilizes self-assembly technology of the block polymer, so that to prepare the high-performance ordered pore nanofiltration membrane has pore diameter of 1-20 nm. The preparation method is simple, and suitable for industrial production. DETAILED DESCRIPTION - Polymer solution comprises polyaryl ether sulfone block polymer of formula (I), good solvent, poor solvent and additive. m, n1 and n2=integers;m=20-100;n1=greater than or equal to1;n2=greater than or equal to1;ratio of m/(n1+n2) =0.5-5;a, b, and c=0-4;R1, R2 and R3=1-4C alkyl, 2-4C alkenyl and 2-4C alkynyl; and A and B=H, 1-5C linear alkyl and 3-5C branched alkyl. The polyaryl ether sulfone block polymer has a number average molecular weight of 10,000-50,000. INDEPENDENT CLAIMS are included for following: (1) A nanofiltration membrane comprises a support, and a polymer layer has polyarylethersulfone block polymer (I), preferably the pore size of the nanofiltration membrane is 1-20 nm, preferably 1-10 nm. (2) A method of preparing nanofiltration membranes, which involves coating the polymer solution on a support, followed by a heat treatment. (3) An application of the polyarylethersulfone block polymer (I) in preparation of a nanofiltration membrane.