High yield of graphene by dispersant-free liquid exfoliation of mechanochemically delaminated graphite

A tremendous work is being done to apply graphene to create novel advanced nanomaterials. The minimized number of few-layer graphene, the absence of different dispersants in the films produced from dispersions of graphene, the concentration of these dispersions are often a key to realizing the goal of achieving high functional performance. Here we show an efficient preparation of graphene by ultrasound disintegration in an organic solvent of the nanostructured graphite obtained by solvent-free mechanochemical delamination in the absence of chemically active compounds. The predominant part of single-sheet graphene nanoparticles in the obtained dispersions is experimentally confirmed. The proposed approach essentially improves the known liquid exfoliation method based on ultrasound disintegration of the bulk graphite, because the proposed preliminary mechanochemical treatment of the initial bulk graphite could provide more than 75 % yield of the single-sheet graphene nanoparticles in the dispersant-free high concentration dispersions (in different organic solvents, including ethanol).