The properties of 3 nm-sized detonation diamond from the point of view of colloid science

Abstract

The colloidal properties of the hydrosol of a detonation nanodiamond have been considered and discussed. The 3nm-sized positively charged colloidal species produced by the NanoCarbon Research Institute, Japan, undergo a further aggregation on the dilution. They exhibit the emission at 625 nm with the excitation maximum at 491 nm, adsorb anionic dyes, and readily coagulate at the adding of electrolytes. The coagulation occurs in line with the Schulze–Hardy rule, the coagulation strength of the anions follows the Hofmeister series, whereas the abnormally high influence of the most hydrophilic anion, HO−, allows revealing the acidic character of the positive surface charge. The hypothesis of the so-called periodic colloidal structures has been put forward in order to explain the dependence of the particle size on the concentration of the hydrosol and the high viscosity of the initial 5.0 wt./vol. % detonation nanodiamond colloid.