Dissolution-aggregation behavior of water-soluble nanographites and their adsorptive characteristics for 2-naphthol in aqueous solutions.

Carbon black was severely oxidized by concentrated nitric acid at 373 K, and the oxidation product was fractionated by ultrafiltration into five groups of a few nanometer-sized water-soluble aromatic compounds, which we called water-soluble nanographites (WSNG1-5). Most WSNGs dissolve in neutral and alkaline 0.1 moldm(-3) NaCl solutions, but precipitate in acidic solutions.