Dispersion behavior and the influences of ball milling technique on functionalization of detonated nano-diamonds

Abstract

Possessing unique characteristics such as super hardness, excellent chemical stability, thermal conductivity and biocompatibility, nanodiamonds are promising materials. High surface energy and the presence of impurities on the surface of detonated nano-diamonds (DNDs) cause agglomeration and poor dispersion in different solvents preventing its commercial exploitation. Functionalization of DNDs is an important technique for making DNDs suitable for commercial applications. Normally, the functionalization of DNDs with triethylene-tetra-amine (TETA) and acids is time consuming. In this work, ball milling has been performed with different milling media (NH4HCO3, NaCl and sucrose) and investigate the effect of different milling media on DNDs de-aggregation followed by its dispersion behavior in different solvents (ethanol, water and dimethyl sulphoxide (DMSO)). Furthermore, aminated DNDs (A-DNDs)/epoxy composites have been fabricated which perform outstandingly in mechanical behavior owing to the better dispersion of milling media assisted A-DNDs in epoxy. Our results indicate that NaCl grains as milling media is better than sucrose, which results in an improved mechanical response of resultant composites on account of its better dispersion and de-aggregation of A-DNDs in epoxy. Therefore, ball milling being fast and controllable technique assists in de-aggregation of A-DNDs in the presence of milling media.