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The production of nanoparticles (Np) is an important sector in current technological development. Processes such as high‐energy grinding are among the most promising because of their high efficiency and low energy cost. In this sense, the filling ratio of vial (FRV) is one of the most interesting and poorly studied process variables that can optimize the production of Np on a large scale. In the present work, dry ZnO Np are produced, with different FRV values (40%, 38%, 23%, and 10%), as well as wet samples. The results show that the variation of the FRV allows to generate an energetic increase of the grinding, modifying the morphology, the particle size, and the surface area of the ZnO powders, without generating structural or chemical changes. The X‐ray diffraction (XRD) results show the presence of the zincite phase (hexagonal) with a variation in crystallinity depending on the FRV, which is due to the deformation of the Np during the process. The XPS results showed a slight chemical shift (variation in binding energy) as a function of grinding because of the activation shown by deformation. UV–VIS analyses showed a marked increase in the magnitude of absorbed intensity for all analyzed samples compared with the commercial powder. These results confirm that FRV is a sensitive parameter in the process of obtaining ZnO Np by the planetary mill technique, which allows efficient control of its characteristics for a given application. [ABSTRACT FROM AUTHOR]

A study of VN/TiN multilayers grown by direct current magnetron sputtering is presented. The systems are produced by maintaining a constant thickness of 500 nm and using three, four, or five bilayers. The coatings are initially characterized using X‐ray diffraction. We observe the formation of TiN and VN phases and obtain values of the texture and stress developed during their growth. The chemical composition of the coatings is analyzed using X‐ray photoelectron spectroscopy. A morphological analysis is carried out using atomic force microscopy, with a roughness of 1.57 nm obtained. The coefficient of friction is determined using the ball‐on‐disc method and is ~0.45 for all samples. It is found that the wear rate is improved with decreasing bilayers as a consequence of the higher interfacial density (number of interfaces per total thickness). Finally, the wear mechanisms are identified as abrasive and adhesive. [ABSTRACT FROM AUTHOR]

The pulsed laser is highly used in optics and material sciences, where the high energy of the laser pulse produces an ablation effect that is applied to the obtention of nanoparticles by impacting a target material. We present a complete methodology that includes the preparation of a CdSe target and the synthesis of CdM (M = Se, O) micro and nanoparticles in water by pulsed laser ablation from the previously prepared CdSe target. The laser energy lets to control the properties of particles; we obtain four CdM micro and nanoparticles samples with four different laser energies, that is, 10.25, 20.72, 30.38, and 39.72 mJ. The best result was achieved with 30.38 mJ; at this energy, we obtain nanoparticles with Z‐average size below 100 nm, confirmed by analysis of dynamic light scattering (DLS). In the scanning electron microscopy (SEM) images of the particles obtained at 30.38 mJ, we observed polydispersity in the sample, in addition to irregularly shaped nanoparticles and particle agglomerations. The analysis of the characterization by UV–Vis, energy dispersive spectroscopy (EDS), and X‐ray photoelectron spectroscopy (XPS) suggests the presence of micro and nanoparticles of CdSe and CdO in the sample. [ABSTRACT FROM AUTHOR]

Currently, studies about the CO2 gas injection improve the production efficiency of crude oil. The surface interaction between CO2 and thin films is a large area of research in the scientific community. In this work, we are showing that The TiZrN (coating) + Si (substrate) system immersed on environments of fully CO2 can interact to below 400°C temperature, because the TiZrN (coating) + Si (substrate) system is broken to temperatures above of the 400°C. The Ti2p, Zr3d, N1s, O1s, and C1s narrow spectra are shown, which illustrate the evolution of TiZrN to TiNx, TiOx, and TiONx compounds and afterwards to TiO2 and ZrO2 phases. TiNx, TiOx, and TiONx compounds are responsible for the increase of the micro‐hardness (measured through Vickers Hardness Testing) of the system (TiZrN [coating] + Si [substrate]) due to that are found at 400°C thermal treatment. Topographical images obtained by atomic force microscopy showed an increase of the surface roughness due to the thermal treatment. Scanning electron microscopy demonstrated that sample submit to 600°C temperature suffered fracture with small indentations. [ABSTRACT FROM AUTHOR]