Unique rheological behavior of detonation nanodiamond hydrosols: The nature of sol-gel transition

Abstract The paper describes the data on unusual rheological properties of detonation nanodiamonds (DND) hydrosols and presents the fractal model explaining such behavior. The hydrosols of DND with particles size of 4–5 nm and concentration range of 1.1–7.3 wt% with negative (ζ   0) electrokinetic potentials have been studied by rotational viscometry, small-angle X-ray scattering, nuclear magnetic resonance and Cryo Electron Tomography. Remarkable hysteresis of viscosity and thixotropic effect demonstrate the sol-gel transition at very low concentrations of the DND: 4–5 wt% for ζ > 0 and 5–6 wt% for ζ