▎ 摘　　要

NOVELTY - Method for preparing thermally-expandable graphene material, involves (i) adding 50-90 pts. wt. graphite, 10-50 pts. wt. sodium nitrate and 10-50 pts. wt. potassium permanganate to reaction vessel, dripping 1-5 pts. wt. concentrated sulfuric acid, maintaining temperature of mixture to be less than 50 degrees C by continuous stirring in ice water bath, dripping 10-50 pts. wt. deionized water during stirring, reacting for 3 hours until solution in reaction vessel changes from black green to bright yellow, washing, filtering, and vacuum-drying to obtain graphene precursor, and (ii) introducing flowing argon gas to high-temperature tubular furnace, increasing temperature to 800-1500 degrees C, adding graphene precursor to crucible, pushing to middle of tubular furnace with iron wire, heating, rapidly expanding graphene precursor to generate thermally-expandable graphene, which does not expand after 30 seconds, pulling thermally-expandable graphene material from crucible to nozzle and collecting. USE - The method is useful for preparing thermally-expandable graphene material which is used in cement (all claimed). ADVANTAGE - The graphene material has unique physical and chemical properties, improves the strength and performance of cement-based materials and reduce the heat of hydration. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the use of the thermally-expandable graphene material in cement.