Abstract:The methods of chemical-mechanical treatments (CMT) were utilized for surface modification of nanodiamond in aqueous medium, and a considerably stable suspension system was thus obtained. The size of all the particles in the provided system was less than 100nm with a narrow distribution and excellent stability, and no obvious change of particle crystal structure after the treatments was observed. The mechanism of the treatments was also discussed. The results show that, because of mechanical treatment effect, addition of ionic surfactants and inorganic regulators, the /ζ/-potential of nanodiamond shifts upwards during the treatments, and the composition of surface functional groups changes. Carboxyl and hydroxyl groups are intensified after the surface modification, which may contribute to the improvement of dispersion and stability. Meanwhile, the addition of non-ionic polymer can also benefit the suspension stability.

Key words: nanodiamond； surface modification； aqueous medium； CMT