Organic-Sulfonate Functionalized Graphene as a High Temperature Lubricant for Efficient Antifriction and Antiwear in Water-Based Drilling Fluid

The lubricity of drilling fluid resistant to high-temperature over 200℃ is still one of the technological breakthroughs. In this study, the graphene modified with sodium dodecylbenzene sulfonate (SDBS) was selected as a resistant to high-temperature lubricant. Our results show that the drilling fluids have high stability after aging at 240°C with the assistance of the SDBS/graphene. Excitingly, the tribological performance test results revealed that the SDBS/graphene exert excellent anti-friction and anti-wear properties. Compared with the base slurry, the friction coefficient and wear rate of the SDBS/graphene slurry are reduced by 76% and 59%, respectively. The deposited film composed of graphene, Al2O3, SiO2, Fe2O3, FeSO4 actualized the protection of the sliding contact zone, proving that the sulfonate group on the SDBS/graphene contributed to prompt the deposition of the graphene and bentonite and then enhanced tribological properties of the drilling fluids. Overall, the graphene modified with SDBS is expected to solve the difficulty to form effective deposited film and poor lubricity of the drilling fluid under high-temperature.

Study the Passivation Characteristics of Microwave Annealing Applied to APALD Deposited Al2O3 Thin Film

In this study, a self-developed atmospheric pressure atomic layer deposition (APALD) system is used to deposit Al2O3 passivation film, along with the use of precursor combinations of Al(CH3)3/H2O to improve its passivation characteristics through a short-time microwave post-annealing process. Comparing the unannealed and microwave-annealed samples whose temperature is controlled at 200–500 °C, APALD non-vacuum deposited film can be realized with a higher film deposition rate, which is beneficial for increasing the production throughput while at the same time reducing the operating cost of vacuum equipment at hand. Since the microwave has a greater penetration depth during the process, the resultant thermal energy provided can be spread out evenly to the entire wafer, thereby achieving the effect of rapid annealing. The film thickness is subsequently analyzed by TEM, whereas the chemical composition is verified by EDS and XPS. The negative fixed charge and interface trap density are analyzed by the C-V measurement method. Finally, the three major indicators of τeff, SRV, and IVoc are analyzed by QSSPC to duly verify the excellent passivation performance.

Annealing Effect on the Structure and Optical Properties of CBD-ZnS Thin Films for Windscreen Coating

Zinc sulfide (ZnS) thin films were prepared and synthesized by the chemical bath deposition (CBD) technique on microscopic glass substrates using stoichiometric amounts of the precursor materials (ZnSO4·7H2O, NH4OH, and CS(NH2)2). Structural, morphological, compositional, and optical characterization of the films were studied. The obtained thin films were found to exhibit polycrystalline possessions. The effect of annealing temperature on the crystallographic structure and optical bandgap of ZnS thin films were both examined. The grain size and unit cell volume were both found to be increased. In addition, the strain, dislocation density, and the number of crystallites were found to be decreased with annealing temperature at 300 °C. However, the annealed sample was perceived to have more Zn content than S. The optical characterization reveals that the transmittance was around 76% of the as-deposited thin film and had been decreased to ~50% with the increasing of the annealing temperature. At the same time, the bandgap energy of the as-deposited film was 3.98 eV and was found to be decreased to 3.93 eV after annealing.

Physical Properties of Different Thicknesses ZnO Thin Films Prepared via Sol-gel Spin Coating Technique

This paper presents the investigation of the thickness of the ZnO thin films by varying the number of deposition layers during the spin coating deposition process. ZnO thin films were deposited with a different number of layers (ranging from 1, 3, and 5), and the main purpose of this study is to explore the effect of the thickness on the properties of ZnO thin films. The deposited thin films were characterised using field emission scanning electron microscope, surface profilometer, and X-ray diffraction. From the characterisation results, the morphology of the ZnO thin films changed significantly with the number of layers and their thickness value. As expected, the thickness increased as the number of layers increased. The crystalline quality of the deposited film improved as the thickness increased. A change in crystallographic orientation was also observed in which the thicker, thin films showed crystal growth in the (102) direction, whereas the thinner one was in the (101) direction. A slight increase in crystallite size for dominant orientation also was observed with the increase of film thickness.

The Role of Substrate on Thermal Evolution of Ag/TiO2 Nanogranular Thin Films

In multicomponent thin films, properties and functionalities related to post-deposition annealing treatments, such as thermal stability, optical absorption and surface morphology are typically rationalized, neglecting the role of the substrate. Here, we show the role of the substrate in determining the temperature dependent behaviour of a paradigmatic two-component nanogranular thin film (Ag/TiO2) deposited by gas phase supersonic cluster beam deposition (SCBD) on silica and sapphire. Up to 600 °C, no TiO2 grain growth nor crystallization is observed, likely inhibited by the Zener pinning pressure exerted by the Ag nanoparticles on the TiO2 grain boundaries. Above 600 °C, grain coalescence, formation of However, the two substrates steer the evolution of the film morphology and optical properties in two different directions. anatase and rutile phases and drastic modification of the optical absorption are observed. On silica, Ag is still present as NPs distributed into the TiO2 matrix, while on sapphire, hundreds of nm wide Ag aggregates appear on the film surface. Moreover, the silica-deposited film shows a broad absorption band in the visible range while the sapphire-deposited film becomes almost transparent for wavelengths above 380 nm. We discuss this result in terms of substrate differences in thermal conductivity, thermal expansion coefficient and Ag diffusivity. The study of the substrate role during annealing is possible since SCBD allows the synthesis of the same film independently of the substrate, and suggests new perspectives on the thermodynamics and physical exchanges between thin films and their substrates during heat treatments.

Enhanced photodetection performance of sputtered cupric oxide thin film through annealing process

This study demonstrates an improvement in the photodetection response of a Cupric Oxide (CuO) thin film through the annealing process. The CuO thin film (400 nm thickness) was deposited on a silicon substrate using DC magnetron sputtering system. Annealing of the as-deposited film was carried out in a muffle furnace at 400 and 500 oC for two hours. X-ray diffraction pattern revealed the formation of a single phase CuO film whose crystallinity improved with increase of the annealing temperature. The field emission scanning electron microscopy indicated a compact and fine granular strcutre of the as-seposited film whereas the segregation and agglomeration of grains was observed after the film’s annealing. The photodetection performance of CuO film with Al contacts was investigated under the exposure of visible light (λ = 460 nm). The current-voltage graphs of as-deposited and annealed films displayed Schottky contact formation between the metal and semiconductor, owing to a lower work function of Al than that of the CuO. The photo-to-dark current ratio of the device was significantly enhanced after the film’s annealing. The increase in photocurrent became more pronounced upon increasing the light intensity from 58.4 to 511 µW/cm2. The maximum current gain and sensitivity values were found to be 66 and 7086.8 % respectively at 10V bias for the film annealed at 500 oC. The rise and fall time of the Al/CuO/Al photodetector was decreased after the film’s annealing.

Effects of the Ethyne Flow Ratio on Structures and Mechanical Properties of Reactive High Power Impulse Magnetron Sputtering Deposited Chromium-Carbon Films

Chromium-carbon films were deposited by utilizing reactive high-power impulse magnetron sputtering with different mixture ratios of ethyne and argon with a constant deposition total pressure while the deposition temperature, pulse frequency, duty cycle and average power of the chromium cathode remain the same. The microstructure and chemical bonding of the obtained films within different composition were compared. The results show that with the increasing ethyne ratio, the carbon content in films increases linearly with two slopes. Moreover, the microstructure of the deposited film changes from a dense glassy structure into a columnar structure, even a clusters structure. The sp2-C bonding in films decreases but the Cr–C bonding increases with decreasing the ethyne ratio. This reveals the main phase of films changes from a hydrogenated amorphous carbon phase into a glassy amorphous chromium carbide phase. Such changes of the microstructure and phase cause a large difference on the film hardness and elasticity.

Surface Stoichiometry and Depth Profile of Tix-CuyNz Thin Films Deposited by Magnetron Sputtering

We report the surface stoichiometry of Tix-CuyNz thin film as a function of film depth. Films are deposited by high power impulse (HiPIMS) and DC magnetron sputtering (DCMS). The composition of Ti, Cu, and N in the deposited film is investigated by X-ray photoelectron spectroscopy (XPS). At a larger depth, the relative composition of Cu and Ti in the film is increased compared to the surface. The amount of adventitious carbon which is present on the film surface strongly decreases with film depth. Deposited films also contain a significant amount of oxygen whose origin is not fully clear. Grazing incidence X-ray diffraction (GIXD) shows a Cu3N phase on the surface, while transmission electron microscopy (TEM) indicates a polycrystalline structure and the presence of a Ti3CuN phase.