▎ 摘　　要

NOVELTY - A sodium alginate-zwitterionic modified graphene oxide mixed composite membrane comprises support layer, and separate layer comprising sodium alginate-zwitterionic modified graphene oxide mixed film. The mass ratio of zwitterionic modified graphene oxide and sodium alginate is 1.25-7.5%. The thickness of separate layer is 230 nm. The support layer comprises polyacrylonitrile ultrafiltration film with molecular weight cutoff 100000. USE - Sodium alginate-zwitterionic modified graphene oxide mixed composite membrane used for separating alcohol/water (claimed). ADVANTAGE - The product has high permeation flux reaching to 722-2140 g/m2h, and separation factor reaching to 851-1370. The method is simple, and has easy to obtain raw materials and mild condition. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of sodium alginate-zwitterionic modified graphene oxide mixed composite membrane comprising: (A) preparing graphite oxide thorough Hummer method, adding deionized water, and ultrasonically processing for 2-3 hours to obtain 0.25-0.45 mg/L graphene oxide dispersion liquid; (B) adding deionized water and N,N-dimethylformamide at volume ratio of 1:1-3:2-4 into container to obtain mixed solution, ultrasonically treating for 30 minutes, putting into oil bath at 50-80 degrees C, adding zwitterionic monomer, stirring under nitrogen for 20-60 minutes at speed of 500 revolutions/minute (rpm), adding 1-2 mg/ml ammonium persulfate aqueous solution under nitrogen, oil bath reacting at 50-80 degrees C for 30-45 hours, cooling, centrifuging, washing with water and alcohol, and drying to obtain zwitterionic modified graphene oxide; (C) washing polyacrylonitrile ultrafiltration membrane with deionized water, drying by airing at room temperature, and fixing on piece with adhesive tape to obtain material A; and (D) taking zwitterionic modified graphene oxide, adding deionized water to prepare dispersion, ultrasonically treating for 1-2 hours, adding 1-3 wt.% sodium alginate, stirring under room temperature for 4 hours at speed of 500 rpm, standing for 0.5-1 hour, defoaming to obtain sodium alginate-zwitterionic modified graphene oxide film casting liquid, rotary coating into material A, drying at room temperature for 24 hours, immersing into 0.2-1.0 mol/L calcium chloride solution for 5-12 minutes, washing with deionized water for 3 times, and drying by airing at room temperature. The mass ratio of zwitterionic monomer and ammonium persulfate aqueous solution is 1:15-40. The mass ratio of zwitterionic monomer at graphene oxide dispersion liquid is 20-50:1. The mass ratio of zwitterionic modified graphene oxide and sodium alginate is 1.25-7.5.