Graphene/water-soluble polymer composite material and preparation method thereof

The invention discloses a graphene/water-soluble polymer composite material and a preparation method thereof. The composite material comprises graphene accounting for 20-90wt% of the total mass of thecomposite material; a modifier accounting for 0.4-70wt% of the total mass of the composite material; and the rest part of the composite material being a water-soluble polymer. The modifier contains an aromatic ring conjugated structure and coats the surface of graphene. The preparation method comprises the following steps: dissolving a modifier containing an aromatic ring conjugated structure anda hydrophilic group in deionized water, adding graphene, and mixing to obtain a surface-modified graphene aqueous dispersion; and mixing the dispersion with an aqueous solution of a water-soluble polymer to obtain a membrane liquid, coating the membrane liquid, and crosslinking to obtain the self-supporting graphene/water-soluble polymer composite membrane material. The modifier is mixed with graphene, the dispersion perf