Amidated nanodiamonds prepared by mechanochemical technology and their dispersion properties

Abstract

The effect of amide functional groups at the nanodiamond surface is of great significance. Herein, we develop a new facile, inexpensive, and contaminant-free approach to modify nanodiamond surface through the mechanochemical amidation of nanodiamond using ball milling technique in the presence of ammonium chloride (NH4Cl) as amidation reagent to introduce the amide functional groups on the nanodiamond surface. It is observed that the amidated nanodiamonds can uniformly disperse well in an aqueous solution. Moreover, the results indicated that the technique is easy to operate and scale-up for industrial application. Furthermore, the well-dispersed nanodiamond colloids can be used for numerous applications including lubrication, thermal interface materials, and drug delivery system. More interesting, the dried amidated nanodiamond can be re-dispersed back to the colloidal solution of a wide range of solvents including water, dimethylsulfoxide, dimethyl formamide and ethanol, which greatly expands the application and functionality of nanodiamond.