▎ 摘　　要

NOVELTY - Preparing layer-by-layer covalent cross-linked graphene oxide film comprises (i) using alkali to activate the polyacrylonitrile film to generate surface active group, taking polyacrylonitrile film as supporting layer and immersing in symmetrical diamine substance solution and graphene oxide dispersion liquid orderly; (ii) taking the symmetrical diamine substance as crosslinking agent and bonding one side of the symmetrical diamine substance molecule with polyacrylonitrile film and other side with the graphene oxide to form a first layer of graphene oxide film; and (iii) repeatedly immersing in the symmetrical diamine substance solution and graphene oxide dispersion liquid to realize symmetrical diamine substance as crosslinking agent and bonding two sides of symmetric diamine molecule respectively bonded with graphene oxide to form a layer-by-layer covalently cross-linked graphene oxide film. The alkali is the 1-2 mol/liter aqueous solution of sodium hydroxide or potassium hydroxide. USE - The layer-by-layer covalent cross-linked graphene oxide film is useful in treating water. ADVANTAGE - The method: prepares layer-by-layer covalent cross-linked graphene oxide film with good stability and strong mechanical properties and better pollutant retention effects. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for layer-by-layer covalent cross-linked graphene oxide film, prepared as mentioned above.