Effect of ultrasonic treatment on the thermal oxidation of detonation nanodiamonds

Abstract

In the present article, we showed the effect of ultrasonic treatment on the thermal oxidation of detonation nanodiamonds (DNDs) by considering the kinetic aspect of their thermal stability in the air, in the framework of the classical Arrhenius approach. Nanostructures and surface chemistry of the pristine, ultrasonicated, and oxidized DNDs were studied by miscellaneous physical techniques to clarify the origin of the effect. Ultrasonic treating decreases the heterogeneity of aggregated nanoparticles and removes admixtures and non-diamond carbon from the surface interface of nanodiamond grains. After thermal oxidation that followed ultrasonication treatment, the size-reduction of nanodiamond crystals caused the annihilation of nitrogen-vacancy centers and led to photoluminescence quenching. Because the number of surface defects reacting with air oxygen decreases after the ultrasonic treatment, the thermal stability of DND nanopowders towards oxidative treatment shows an increase.

Nanodiamond-Polymer Composites for Decreased Laser Ablation Thresholds

“…The presence of absorption of NDs below the diamond band gap (5.5 eV) can be attributed to local absorption centers such as lattice or surface defects. , In the case of surface-graphitized diamonds, the influence of the graphite surface can also be assumed. Transmission measurements of the composites are challenging (Figure c) as direct determination of contributions of diffuse scattering and optical absorption on the obtained absorption spectra is not possible.…”

Preparation and Characterization of Carbon-Silicon Hybrid Nanostructures

“…5) show that these carbon NPs are semi-amorphous; the thickness of their layer does not exceed 1 nm and, probably, performs an auxiliary function, regulating the size of NPs and preventing their aggregation. A surface interface of this type performs a passivation function, preventing deep amorphization during oxidation of carbon NPs [23], as a result of interaction with the environment during the operation of devices, and plays the role of a spacer between carbon (amorphous) NPs and structured Si NPs, forming the body and structure of nanohybrids. The large curvature of the surface of Si@C hybrids could change the topology of atomic bonds on the surface.…”

Photoluminescent Recognition of Strong Alcoholic Beverages with Carbon Nanoparticles

“…TGA of carbon NPs was carried out in an argon gas flow with a custom TGA instrument . FTIR ATR spectrum was recorded with an IR Prestige-21 spectrometer (Shimadzu) equipped with a MIRacle ATR accessory (PIKE Technologies) with a ZnSe crystal for the sample contact.…”

“…TGA of carbon NPs was carried out in an argon gas flow with a custom TGA instrument. 52 FTIR ATR spectrum was recorded with an IR Prestige-21 spectrometer (Shimadzu) equipped with a MIRacle ATR accessory (PIKE Technologies) with a ZnSe crystal for the sample contact. 1 H NMR spectrum was recorded at 400 MHz on a Varian Mercury 400 spectrometer with tetramethylsilane as an internal standard in DMSO-d 6 .…”