▎ 摘　　要

NOVELTY - Double cross-linked graphene oxide composite film comprises graphene oxide nanosheets, polyvinylamine interposed between graphene oxide layers, and inorganic cross-linking agent silicon oxide which is generated by induced bionic mineralization. The polyvinylamine is inserted between the graphene oxide layers as macromolecular crosslinking agent to obtain polyvinylamine crosslinked graphene oxide composite film. The quality of the polyvinylamine and the graphene oxide is 0.07:1. The bionic mineralization is performed in the restricted space of the stack of graphene oxide nanosheets to generate nanoparticles to obtain double cross-linked graphene oxide composite film. USE - Double cross-linked graphene oxide composite film. ADVANTAGE - The double cross-linked graphene oxide composite film has strong controllability, simple preparation process, high permeation flux, selectivity for water molecules, and good operating stability at high temperature. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing double cross-linked graphene oxide composite film, which involves: (A) dissolving certain amount of polyvinylamine in pure water and sonicating for 30 minutes to obtain dispersion of polyvinylamine; (B) dissolving graphene oxide in the above-mentioned polyvinylamine dispersion to obtain mixed solution A, mass ratio of polyvinylamine and graphene oxide is 0.07:1, stirring mixed solution A at room temperature for 0.5 hours and then sonicating for 15 minutes at 0.5 megapascal pressure, filtering mixed solution A after ultrasonic stirring to hydrophilic polytetrafluoroethylene membrane with pore size of 0.22 micrometer, and then placing in 90 degrees C oven for cross-linking for 4 hours to obtain polyvinylamine cross-linked graphene oxide composite film; (C) immersing polyvinylamine crosslinked graphene oxide composite film obtained in aqueous solution for 2 hours, then immersing in sodium silicate solution for mineralization, concentration of the sodium silicate solution is 10-30mmol/L, pH value is 5-10, soaking time is 0.25-3 hours, then taking out membrane, rinsing with deionized water; and (D) drying at room temperature to obtain final product.