Structural changes in colloid solutions of nanodiamond

Abstract

Dielectric permittivity, conductivity, density, viscosity and heat capacity measurements of dilute (0.01–0.1%) aqueous colloids of nanodiamond indicate that DND particles substantially affect the properties of water at surprisingly long distances from their surfaces. Luminescent microscopy reveals a uniform lattice-like pattern of DND agglomerates, probably held together by electrostatic interactions mediated by rearranged water molecules, at distances of a few μm. Heating, slow evaporation or dilution of the colloids causes quasi-periodic fluctuations of their electrophysical properties: as the particles coagulate, larger aggregates precipitate in accordance with Stokes law, which reduces the average size of the remaining suspended particles and alters their quasi-lattice arrangements in low-ΔH phase transitions.