Hydroxylation and self-assembly of colloidal hydrogenated nanodiamonds by aqueous oxygen radicals from atmospheric pressure plasma jet

Abstract

Colloidal nanodiamonds are hydroxylated by action of plasma-supplied O atoms and undergo self-assembly to chains.

Hydrogen plasma treated nanodiamonds lead to an overproduction of hydroxyl radicals and solvated electrons in solution under ionizing radiation

“…Nevertheless, the very broad band with a strong contribution at 1090 cm -1 can be interpreted as the C-O-C stretching mode. This band is more intense than on spectrum of freshly prepared and dried H-ND (not shown), as already reported by Jirasek et al [29]. This partial reoxidation of the H-ND, already observed in XPS analysis, may be assigned to their dispersion in water as suspensions were characterized several days after preparation, when irradiations were performed.…”

Size Effects on Surface Chemistry and Raman Spectra of Sub-5 nm Oxidized High-Pressure High-Temperature and Detonation Nanodiamonds

“…showing individual DND particle deposition on a substrate after simple dropcasting 49 or ultrasonic bath-assisted seeding 24,41,42,51 which confirms that individual NDs can exist in the colloidal solution and/or the weakly bound aggregates can indeed be broken up by an external force.…”

Using hydrogen isotope incorporation as a tool to unravel the surfaces of hydrogen-treated nanodiamonds

“…These positive Zeta potentials are in line with reported studies dealing with hydrogen-treated DND whatever the hydrogenation method (annealing 13 or plasma 11 ). Its origin is still under debate, according to spectroscopic investigations, it may imply the interactions with surrounding water molecules 14,15,24 .…”

“…According to the literature, this surface treatment also confers: 1) a stability in aqueous solutions with a positive Zeta potential 11 which permits, via an electrostatic grafting, to use DND as a vector of biologics such as small interfering RNA 12 or as seeds for diamond growth by chemical vapor deposition 13 ; 2) modifications in the structure of water molecules surrounding hydrogen-treated DND compared to other surface chemistries according to spectroscopic investigations 14,15 ; 3) a radiosensitisation behavior reported in vitro for radioresistant cancer cells 16 and an overproduction of hydroxyl radicals in water under X-ray irradiation 17 ; 4) the grafting of biomolecules through diverse functionalization strategies 9,18,19 ; 5) specific fluorescence properties 20 . Until now, two different approaches were developed to hydrogenate DND: one involving a hydrogen microwave plasma 9,21 , the other, a thermal annealing under hydrogen [22][23][24] .…”