▎ 摘　　要

NOVELTY - Composite of graphene and Congo red comprises two soluble phases, where the mass ratio of graphene to Congo red is 5:1-10. USE - The composite of graphene and Congo red is useful for industrial and commercial applications. ADVANTAGE - The maximum solubility of the composite in water is 7.5 mg/ml and it can stably exist for more than 3 months. The solubility of the composite in solution of N, N-dimethyl formamide is 2 mg/ml and it can stably exist for 2-3 weeks. The composite supplies ideal graphene material for practical application. DETAILED DESCRIPTION - Composite of graphene and Congo red of Formula (I) comprises two soluble phases, where the mass ratio of graphene to Congo red is 5:1-10. An INDEPENDENT CLAIM is a preparation method for composite of graphene and Congo red with two soluble phases comprising: (a) preparing graphene: mixing water solution of graphene oxide having a concentration of 0.5 mg/ml, hydrazine hydrate solution having a mass fraction of 50% and ammonia water solution having a mass fraction of 25% in a reactor; mass ratio of graphene oxide, hydrazine to ammonia is 10: 7-35: 35-175; stirring and reacting them for 0.5-1 hour in oil bath of 80-110 degrees C; obtaining solution of graphene; and (b) preparing composite of graphene and Congo red: adding Congo red in the solution of graphene obtained in step (a) according to mass ratio of graphene to Congo red of 5:1-10; stirring and reacting them for 10-48 hours in oil bath of 30-60 degrees C; cooling them to 20-25 degrees C; filtering them by using nylon film of 0.22 micron; washing them twice with water until the filtrate is colorless; then obtaining composite of graphene and Congo red with two soluble phases.