Chemical Properties of Diamond

An unterminated diamond surface has a propensity to form π bonds between adjacent carbon atoms.  Once formed, it is energetically difficult to break these bonds. When the diamond surface is reconstructed with these π bonds, other prospective chemical bonds (almost always of lower energy than the π bonds on the diamond surface) cannot chemically bond to its surface.  For decades, miners have exploited diamond’s low surface energy by washing diamond containing gravel over a grease table.  Most materials are readily wet by the water and flow over the table, but diamond’s hydrophobicity results in it sticking to the grease at the bottom of the table.

The high atomic density and low surface energy of diamond results in a surface that is biologically inert.  For this reason, diamond has excited much interest as a material for biomedical applications.  Orlando Auciello and Steven Prawer have been particularly interested in cybernetic implants in the eye, where even small amounts of scar tissue or tissue irritation would cause immense problems.