Microwave-assisted purification of detonation nanodiamond

• Published in: Diamond and related materials Vol. 48; pp. 37 - 46
• Main Authors: Mitev, Dimitar P., Townsend, Ashley T., Paull, Brett, Nesterenko, Pavel N.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-09-2014; Elsevier
• Subjects: Complexing reagents; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Detonation nanodiamond; Discharges for spectral sources (including inductively coupled plasmas); Electric discharges; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Liquid-phase purification; Materials science; Methods of nanofabrication; Microwave; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Solid surfaces and solid-solid interfaces; Specific materials; Surface properties; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Microwave; Surface properties; Complexing reagents; Detonation nanodiamond; Liquid-phase purification; Purification; Synthetic diamond; Soot; Polycrystalline diamond; Particle size distribution; Inductively coupled plasma; Adsorption; Detonations; Residual impurity; Impurity states; Nanostructured materials; Depth profiles; Nanomaterial synthesis; Concentration distribution
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2014.06.007

In the present work microwave-assisted purification approaches for detonation nanodiamond (DND) are considered, and the resultant impurity content of purified DND revealed by direct ICP-MS and elemental analysis. A significant reduction in noncarbon contaminants as compared with detonation soot was achieved with resulting purity of 99.95%. Surface characterisation including scanning electronic microscopy, low temperature adsorption of nitrogen, acid–base potentiometric titration, zeta potential measurements and particle size distribution of the DND in suspensions revealed distinctive surface properties for each purified DND sample. Results highlight the suitability of the microwave purification approach using acid reagents, allowing nanodiamonds with different and reproducible surface properties to be produced or modified. Contamination effects from laboratory glassware used to store samples were carefully considered. Refined DND with impurity levels over two orders of magnitude lower than commercially available samples was prepared. The profile and concentration levels of residual impurities in purified samples of nanodiamond are discussed with identification of possible reasons for contamination.
•New purification scheme of detonation nanodiamonds is proposed.•Purification degree of 99.95% is achieved for detonation nanodiamonds.•Laboratory glassware is identified as a source of substantial contamination of nanodiamonds.