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Electrical discharge in liquids is a research field that has great potential in environmental and technological applications. Depending on the experimental conditions (liquid nature, interelectrodes distance, applied voltage, pulse width, etc.), various discharge modes can be obtained. The involved physical processes have relatively fast spatiotemporal dynamics and, therefore, are not well understood. In this study, we report the electrical characterization, coupled with time-resolved light detection (using a photomultiplier, PM, tube), of positive and negative pulsed nanosecond spark discharges in de-ionized water using copper electrodes (distanced by ∼50 μm) in a pin-to-plate configuration. A detailed analysis of the current–voltage waveforms during the pre-breakdown and the breakdown phases is shown, and we found that the pre-breakdown phase depends on the high voltage magnitude only for positive polarity. On the other hand, the PM signals showed dependence on the voltage magnitude and on the pulse width, and various emission phases are observed. These phases can be related to the discharge power and/or to the discharge current. Filtered PM signals at various wavelengths are also acquired, and their temporal dynamics are discussed regarding the discharge conditions. [ABSTRACT FROM AUTHOR]

A one‐step technique for the deposition of superhydrophilic TiO2@carbon nanocomposites is described in this study. The nanocomposites are synthesized by injecting TiO2 nanoparticles suspended in isopropanol into a dielectric barrier discharge operating at atmospheric pressure (AP‐DBD) generated in an N2/N2O gas mixture. The influence of the voltage (3–8 kV) applied to a 2‐kHz‐operated AP‐DBD on the wettability of the as‐deposited TiO2@C nanocomposites is examined. The water contact angle is drastically reduced from 93° for the reference TiO2 powder to <5° for the deposited nanocomposite. This superhydrophilicity is not caused by the increase of the surface roughness determined by atomic force microscopy measurement but rather by the higher density of graphitic compounds at the surface, as confirmed by X‐ray photoelectron spectroscopy measurements. [ABSTRACT FROM AUTHOR]

Studies the limits to ion energy control in high density glow discharges. Details on the experiment; Information on the metastable densities; Conclusions.

Atmospheric pressure Dielectric Barrier Discharge (AP-DBD) was used to deposit homogeneous carbon-TiO2 composites. Non-intrusive Laser Light Scattering was employed to study the transport of the nanoparticles across the plasma. The characteristics of the coating were found to depend on the gas flow and on the spray chamber used for introducing the nanoparticles (cyclonic and Scott spray chambers). According to the SEM images, higher gas flows favor the formation of more homogeneous coatings both in terms of thickness and NPs-aggregates distribution regardless of the spray chamber. The Scott spray chamber was shown to be more efficient for the deposition of uniform coatings even at low gas flows. It also yields the highest Ti concentration that reaches up to 18%. Furthermore, the light scattered by the nanoparticles was shown to be directly related to the coating thickness, hence to the density of nanoparticles in the plasma. [ABSTRACT FROM AUTHOR]