▎ 摘　　要

NOVELTY - Preparation of graphene oxide involves adding oxidized graphene, alkaline substances and acid or sodium chloroacetate under ultrasonic action, mixing the graphene oxide dispersion to distilled water, dispersing, obtaining graphene oxide dispersion, adding graphene oxide dispersion to the basic substance, mixing hexahydrated gadolinium chloride or hexahydrated gadolinium nitrate, adding aqueous solution of salt of gadolinium oxide, adding aqueous solution of diethylene triamine pentaacetic acid, obtaining mixed solution, dialyzing obtained mixed solution. USE - Preparation of graphene oxide (claimed). ADVANTAGE - The graphene oxide is efficiently prepared with excellent dispersion stability, and high longitudinal relaxation rate. DETAILED DESCRIPTION - Preparation of graphene oxide involves adding 1-3 parts mass oxidized graphene, 50-120 parts mass alkaline substances and 50-100 parts mass acid or sodium chloroacetate under ultrasonic action, mixing the graphene oxide dispersion to distilled water, dispersing for 1-2 hours, obtaining graphene oxide dispersion with concentration of 0.5-2.5 mg?mL-1, adding graphene oxide dispersion to the basic substance, adding chloroacetic acid or sodium chloroacetate at 30-40 degrees C under ultrasonic dispersion for 1-4 hours, obtaining carboxylated graphene oxide dispersion, centrifuging carboxylated graphene oxide dispersion, performing washing treatment, then adjusting the pH value to 5-6.5, carboxylating, obtaining pure graphene oxide dispersion, freeze-drying, obtaining carboxylated graphene oxide, adding 100-150 parts mass carboxylated graphene oxide, 1-30 parts mass hexahydrated gadolinium chloride or hexahydrated gadolinium nitrate, and 10-300 parts mass 5% aqueous solution of diethylene triamine pentaacetic acid, dispersing carboxylated graphene oxide in distilled water, obtaining carboxyl graphene oxide dispersion with concentration of 0.2-3.5 mg?mL-1, mixing hexahydrated gadolinium chloride or hexahydrated gadolinium nitrate, dubbing gadolinium concentration of aqueous solution of salt to 0.5-10 mg?mL-1.second, adding aqueous solution of salt of gadolinium oxide to obtained carboxylated graphene dispersion at 25-50 degrees C, stirring the reaction for 7-12 hours, adding aqueous solution of diethylene triamine pentaacetic acid with concentration of 5 %mass, mixing, obtaining mixed solution, dialyzing obtained mixed solution.