The Surface Properties of Nanodiamonds As Examined by Gas Chromatography

Two samples of detonation nanodiamond (ND) were studied using gas chromatography. Sample ND-Cr was treated by boiling sulfochromic acid with liquid-phase acid purification. Sample ND-Oz was treated with gaseous ozone. The retention times determined for nine substances of different nature at various temperatures were used to calculate the specific retention volumes and the thermodynamic parameters of adsorption of test compounds on ND-Oz and ND-Cr. The adsorption heats of tested n-hydrocarbons on nanodiamond powders, especially on ND-Oz, are close to those on graphitized carbon black (GTB). For benzene and polar compounds, the specific interaction terms in the total energy of adsorption were determined. These terms are higher for ND-Oz than for ND-Cr; i.e., sample ND-Oz contains more reactive functional groups.