▎ 摘　　要

NOVELTY - The preparation of quaternary ammonium salt-polyvinyl alcohol-nanocrystalline cellulose-oxidized graphene composite film involves mixing nanocrystalline cellulose and graphene oxide aqueous dispersion, stirring, adjusting the concentration of nanocrystalline cellulose/graphene oxide composite liquid, and ultrasonically dispersing to obtain nanocrystalline cellulose/graphene oxide composite dispersion, dissolving polyvinyl alcohol in deionized water to obtain uniform polyvinyl alcohol aqueous solution, adding composite dispersion, stirring, defoaming, and pouring into a glass mold. USE - Preparation method of quaternary ammonium salt-polyvinyl alcohol-nanocrystalline cellulose-oxidized graphene composite film (claimed). ADVANTAGE - The method enables preparation of quaternary ammonium salt-polyvinyl alcohol-nanocrystalline cellulose-oxidized graphene composite film with excellent water resistance, mechanical property, and thermal stability. DETAILED DESCRIPTION - The preparation method of quaternary ammonium salt-polyvinyl alcohol-nanocrystalline cellulose-oxidized graphene composite film involves (1) mixing nanocrystalline cellulose and graphene oxide aqueous dispersion according to mass ratio of 1:2, stirring at room temperature for 10 minutes, adjusting the concentration of nanocrystalline cellulose/graphene oxide composite liquid to 0.005 g/ml using deionized water, and ultrasonically dispersing in an ultrasonic cleaning machine with 100 W for 30 minutes to obtain nanocrystalline cellulose/graphene oxide composite dispersion, (2) dissolving 2 g polyvinyl alcohol in 25 ml deionized water at 90 degrees C to obtain uniform polyvinyl alcohol aqueous solution, adding the nanocrystalline cellulose/graphene oxide composite dispersion obtained in the step (1) to the polyvinyl alcohol aqueous solution, controlling the content of nanocrystalline cellulose/oxidized graphene composite nanoparticles to 3 %mass of polyvinyl alcohol, and stirring at 50-60 degrees C for 20 minutes to obtain polyvinyl alcohol/nanocrystalline cellulose/oxidized graphene composite solution, defoaming the polyvinyl alcohol/nanocrystalline cellulose/oxidized graphene composite solution, pouring into a glass mold, leaving still at room temperature for 12-24 hours, and drying at 40 degrees C for 3-5 hours to obtain polyvinyl alcohol/nanocrystalline cellulose/oxidized graphene composite film, (3) adding a certain amount of quaternary ammonium salt monomer, crosslinking agent, and initiator, dissolving in a mixed solution of ethanol/water, and ultrasonically dispersing for 20 minutes to obtain quaternary ammonium salt composite solution, and (4) immersing the polyvinyl alcohol/nanocrystalline cellulose/oxidized graphene composite film in quaternary ammonium salt composite solution for 1-7 hours, exposing the composite film under UV lamp for 2 minutes, and repeatedly washing with ethanol and water.