Abstract
Sub-micron sized diamond powder was heat-treated in a wet oxidizer or in hydrogen gas. The recovered powder was observed under FTIR to study the radicals adhering to the surface. Also the suspension characteristics of the powder in water were examined in test tubes.
The results were as follows:
-Hydrophilic radicals, such as C=O, C-O-C, OH were detected on the diamond as heated in sulfuric-nitric mixed acid.
-The powder remained in suspension for more than 24 hours in water.
-The hydrophilic radicals were readily converted to C-H when heated in hydrogen.
-There were possibilities for controlling the surface condition of sub-micron diamond by heating in either oxidizer or hydrogen.
