Adsorption and Electrical Properties of Nanodiamond Powders in the Presence of Water Vapor

摘要

The adsorption of water vapor on nanodiamond (ND) powders of detonation synthesis with various chemical states of the particle surface is investigated. The specific surface, porosity, and isotherms of water-vapor adsorption by ND powders are determined. It is shown that ND surface chlorination leads to a decrease of concentration of the primary adsorption centers determining the amount of water adsorbed. The data on the influence of the water vapor relative pressure on electrical conductivity G and dielectric permeability of the powders before and after chemical modification of ND are obtained. The interconnection between the amount of adsorbed water and ND electrical parameters is considered within percolation theory. It is shown that water-vapor adsorption leads to a giant increase in the dielectric permeability value and significant rise of conductivity near percolation threshold.