| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 700784 | Diamond and Related Materials | 2012 | 4 Pages |
Nanodiamond (ND) particles are usually bound in aggregates that are difficult to separate into a single nanoparticle form, which restrains their applications. Recently, a stable suspension of deaggregated NDs [1] has been prepared using annealed ND samples. We discuss the mechanism of deaggregation of these NDs based on our 1H NMR data. We show that in contrast with the spectra of the initial sample, those of the annealed sample evidence fast proton exchange between the surface carboxyl groups and adsorbed water molecules and the formation of charged ND–COO− ↔ H3O+ structures, which results in repulsion of ND particles and yields a stable aqueous suspension of isolated NDs.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► NMR spectra of annealed and de-aggregated nanodiamond ► Proton exchange between carboxyl groups and water molecules ► Formation of hydroxonium ions and double electric layer around nanoparticles ► De-aggregation of diamond nanoparticles is explained based on NMR data.
