An anatase TiO.sub.2 coating doped with trace silver and paracetamol components was manufactured via the impregnation method combined with the potentiostatic reduction approach. The surface ...morphologies, microstructures and components were characterized via many surface analytical technologies. In addition, an electrochemical evaluation approach was developed to assess degradation behaviors of the beneficial chemicals in the phosphate buffer solution (PBS). The results demonstrated that the TiO.sub.2 coating was loaded with silver and paracetamol successfully. The Ag-oxy-carbide complex, coming from the reaction of silver ions and with hydroxyl groups in paracetamol, was helpful for the beneficial species sustainedly releasing from the coating during the 18-day immersion and remaining in the coating even after 18-day immersion in the PBS.
Properties of atmospheric black carbon (BC) particles were characterized during a field experiment at a rural background site (Melpitz, Germany) in February 2017. BC absorption at a wavelength of 870 ...nm was measured by a photoacoustic extinctiometer, and BC physical properties (BC mass concentration, core size distribution and coating thickness) were measured by a single-particle soot photometer (SP2). Additionally, a catalytic stripper was used to intermittently remove BC coatings by alternating between ambient and thermo-denuded conditions. From these data the mass absorption cross section of BC (MAC.sub.BC) and its enhancement factor (E.sub.MAC) were inferred for essentially water-free aerosol as present after drying to low relative humidity (RH). Two methods were applied independently to investigate the coating effect on E.sub.MAC : a correlation method (MAC.sub.BC, ambient vs. BC coating thickness) and a denuding method (MAC.sub.BC, ambient vs. MAC.sub.BC, denuded). Observed E.sub.MAC values varied from 1.0 to 1.6 (lower limit from denuding method) or â¼1.2 to 1.9 (higher limit from correlation method), with the mean coating volume fraction ranging from 54 % to 78 % in the dominating mass equivalent BC core diameter range of 200-220 nm. MAC.sub.BC and E.sub.MAC were strongly correlated with coating thickness of BC. By contrast, other potential drivers of E.sub.MAC variability, such as different BC sources (air mass origin and absorption Ãngström exponent), coating composition (ratio of inorganics to organics) and BC core size distribution, had only minor effects. These results for ambient BC measured at Melpitz during winter show that the lensing effect caused by coatings on BC is the main driver of the variations in MAC.sub.BC and E.sub.MAC, while changes in other BC particle properties such as source, BC core size or coating composition play only minor roles at this rural background site with a large fraction of aged particles. Indirect evidence suggests that potential dampening of the lensing effect due to unfavorable morphology was most likely small or even negligible.
In this work, one-dimensional conductive TiO.sub.2 whiskers coated with antimony-doped tin oxide (ATO@TiO.sub.2) were prepared with a method of hydrothermal coprecipitation. Specially, sodium ...hexametaphosphate (SHMP) was used as an interfacial reactor to form sufficient active groups on the surface of TiO.sub.2 whiskers, which not only increased the reaction sites, but also formed the electric double-layer structure to promote the dispersion of TiO.sub.2 whiskers in aqueous solution. Additionally, four kinds of ATO@TiO.sub.2 nanomaterials with different appearances were introduced into waterborne polyurethane (WPU) emulsion to prepare the conductive paint for the surface coating of polyester fabrics. During the process of curing reaction, ATO@TiO.sub.2 whiskers are located in the coating mold to organize a conductive network in the form of a rod-to-rod connection. Compared with particle-type ATO@TiO.sub.2, the percolation threshold was drastically decreased from 45 to 7.5 wt%, meanwhile, this conductive paint shows excellent covering performance and the whiteness is up to 83.
Hollow rod-like Mg(OH).sub.2-xF.sub.x sol was synthesized by a solvothermal method, and then organic-inorganic hybrid Mg(OH).sub.2-xF.sub.x-MTES copolymer sol was obtained by a hydroxyl condensation ...reaction between Mg(OH).sub.2-xF.sub.x and MTES hydrolysate. The copolymer sols were deposited on glass substrates by a dip-coating method. The results showed that the average transmittance of the coating reached 99.13% in the visible wavelength range of 400-800 nm, and the water contact angle of the coating reached 133.3°. After the coatings were irradiated by ultraviolet light for 1200 h, the transmittance and the water contact angle of the coatings were hardly affected, the coatings exhibited excellent hydrophobicity and ultraviolet durability. At the same time, the mechanical properties of the coating are greatly enhanced by the formation of Si-O-Mg bond and the coatings have the advantage of durability in harsh environments.
In a particular temperature range, 1, 2-benzo-6-diethylamino-fluorane microcapsules (fluorane microcapsules) exhibit a good color-changing function. For the coating on wood surfaces, embedding ...fluorane microcapsules, good weather resistance, light retention, color retention, impact resistance, and wear resistance are essential. However, the effect of fluorane microcapsule content on its properties has not been verified. Therefore, in this paper, the orthogonal test is designed with the fluorane microcapsule content, drying temperature, and drying time as test factors to identify the most influential factors. Then, by embedding microcapsules into the waterborne coating on wood substrates, the performance of the waterborne topcoat was investigated. The results show that the color of the waterborne topcoat with fluorane microcapsules on a basswood (Tilia europaea) surface can change between yellow and colorless when the temperature rises and falls, achieving reversible thermochromism. The activation temperature was 32 °C, and the range of discoloration temperature was 30-32 °C. The topcoat with a 15% fluorane microcapsule content had the best comprehensive performance. The color difference was 71.9 at 32 °C, the gloss was 3.9% at 60°, the adhesion grade was 0, the hardness was 2H, the impact resistance was 10 kg·cm, the elongation at the break was 15.56%, and liquid resistance was outstanding. After aging tests, the color difference of the topcoat with 15% fluorane microcapsules was more obvious. The damaged area of the topcoat with the addition of 15% fluorane microcapsules was smaller, indicating it had a better aging resistance. The experimental results lay the foundation for the preparation of intelligence-indicating and decorative waterborne coating.
Surface modification is widely adopted as a viable solution for surface damage under sliding or impacting conditions. Various coatings can be manufactured using different techniques and it has been ...applied on various substrates in previous studies which results in different characteristics. This review presents the anti-wear techniques with a focus on the most recent coatings of superior properties. Hard protective coatings may consist of various compositions; however, based on the hardness and the resistance to wear, some of the frequently used elements are Titanium (Ti), Nickel (Ni), carbides, Zirconium (Zr), Boron (B) and the Diamond Like Carbon (DLC). The deposition methods such as Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD) as well as the cutting-edge coating hybrid-deposition methods such as Pulsed DC Magnetron Sputtering (PDCMS), High Power impulse (HiPIMS) and Arc Ion Plating (AIP) are reviewed and the resulted significant differences in the coating properties are discussed. In this review, listing the most important findings from previous studies in a table for each group of coatings make it easy to compare between various techniques and coatings. Some of the listed factors affecting the coating properties, such as the substrate, and others affecting the coefficient of friction, such as the counter body, were not been sufficiently highlighted before despite their importance in analyzing the tribological behavior for the coatings investigated. Although the focus was on the most recent studies, a wide range of studies was covered in order to accumulate and integrate the knowledge toward a complete analysis and discussion. Coating hardness is essential for better wear resistance; however, coating bonding, thickness and roughness may be equally important. Various techniques are used to improve the bonding. For some coatings, the Coefficient of Friction (CoF) increases with increasing the wear resistance where the counter body plays a major role. For most of the deposition techniques, the controlling parameters are the cleaning treatment, arc current, pressure, time, and gas supply. It was found that diamond-like carbon coatings are among the hardest coatings and the Plasma-Assisted Chemical Vapor Deposition (PACVD) is frequently reported as one of the most promising deposition techniques. Many coatings including the diamond-like carbon coating were not been investigated for their erosion wear resistance by solid particles despite the importance of such investigations for many applications.
•Coatings based on Titanium, Nickel, carbides, Zirconium, Boron and the Diamond Like Carbon are discussed and compared.•Coating properties according to deposition technique such as CVD, PVD, and Pulsed DC Magnetron Sputtering are discussed.•Coatings properties, testing conditions, deposition techniques and other parameters are listed in comparative tables.•Coating hardness is important but coating-substrate adhesion controlled by deposition techniques may be more significant.•Plasma-Assisted Chemical Vapor Deposition is frequently reported as one of the most promising deposition techniques. There is a limited number, and sometimes a lack, of solid particles erosion studies for the recently developed coatings.
This edition includes sixteen publications covering various applications in the field of ceramic coatings. This Issue features ceramic coatings developed through plasma spraying, magnetron ...sputtering, and plasma-electrolytic oxidation. It is appropriate for graduate students, scientists, and engineers interested in corrosion and wear-resistant high-temperature coatings for industrial applications.
