A water-based gel of nano-diamond powders was prepared and was stably dispersed in water. Transmission electron microscope and infrared test were respectively carried out to observe the morphology and the surface groups attached to the powders, and size analysis experiment was performed to research the size distribution of the dispersed diamond particles. Results indicated that Tween-80 molecules, at least partial chemical groups of Tween-80, were successfully adsorbed onto the surfaces of the powders; the poor dispersion of raw diamond powders was greatly improved, the average particle size was reduced to around 18.36 nm and the sizes of most powders ranged from 13.2 nm to 20.9 nm. And no particle aggregation and precipitation was observed even if the gel were heated up to 95 °C and stored for 18 months.
Fig. 1. a. TEM photo of raw powders. b. TEM photo of surface-modified powders.