Papers by Keyword: Wettability

Abstract: It is of great interest to be able to remove residues of impregnating material from the resulting article in order to reduce the cost of manufacturing such parts. To this end, a thermodynamic calculation allows you to obtain the necessary conditions for obtaining high-quality products.

Abstract: The common reed, Phragmites australis, is a plant species quite similar to the currently used bio-based aggregates and available on most continents. The purpose of this work is to characterise this common reed and compare its properties to other plants already studied for building use. This study presents the different properties focussing on Phragmites australis chemical composition, hydrophobicity nature and how this character could be explained. To that end, wettability and also water adsorption measurements were carried out on plant flour and aggregates in comparison to miscanthus, wood and hemp shiv properties. Formulations based on reeds of different origins and using different binders (lime and earth) were tested in compression and with thermal conductivity measurements in order to evaluate the behaviour of the reed as a material for building use.

Abstract: Cerium oxide (CeO₂) is one of potential candidates of hydrophobic coatings servicing in harsh environments. In this letter, abraded CeO₂ surface was prepared using sandblasting treatment to investigate the wetting mechanism under the condition of impact abrasive wear. The water contact angle (WCA) of the abraded surface increased from 62.8° to 93.7° after aging in ambient air for about 700 h. The hydrophobic self-optimisation mechanism of the abraded CeO₂ surface is due to the hierarchical structure formed during impact abrasive wear and the surface adsorption of airborne hydrocarbon, resulting the wetting state changed from “Wenzel state” to “Cassie-Baxter State”.

Abstract: Material choices for liquid lead bismuth spallation target are some of austenitic stainless steel, ferrite martensitic steel and cold-worked austenitic stainless steel. In order to ensure materials resistance to irradiation and corrosion as well as compatibility with lead bismuth, it is appropriate to lower the incident proton current density and the process temperature, in which temperature range engineering design can control to work, especially in ADS (Accelerator-Driven nuclear transmutation System) concept. The lower limit temperature is determined from the physical melting temperature and the engineering efficiency of the steam generator involved in process control. The material related issues for liquid lead bismuth are mass loss by impinging secondary flow, wettability at the device interface for ultrasonic waves application, detachable control of the slag in the flowing system, stabilized electrical resistance between the material and the liquid lead bismuth interface. Electromagnetic fluid analyses show how flow rate relates electrical resistivity of flow channel material.

Abstract: MnZn Spinel ferrite with the chemical formula of Mn_xZn_1-xFe₂O4 (x = 0, 0.25, 0.5, 0.75, 1.0) were synthesized by a sol-gel auto-combustion method. Structural and morphological properties of synthesized samples were characterized by X-ray diffraction (XRD) and Field Emission Microscopy (FESEM). XRD patterns revealed characteristic peaks corresponding to spinel Mn-Zn ferrite structures. In addition, the structural analysis demonstrates that the average crystallite size of the synthesized samples varied in the range of 30.0-40.0 nm. The FESEM micrographs reveal agglomerated particles with particles size ranging from 60-80nm. Interfacial tension (IFT) and contact angle measurement for MnZn ferrite nanofluids were performed. The results showed that the use of MnZn ferrite nanofluid significantly decrease the oil-water IFT and contact angle.

Abstract: In this study, organic strip, particle removal efficiency and wettability were investigated at different mixing concentrations of diluted Sulfuric-Peroxide-HF (DSP⁺) solutions with and without the addition of IPA. Organic strip evaluation was carried out with KrF photoresist (PR), and the strip rate was increased rapidly with the increase in H₂SO₄ concentration mixed with DI water (DIW). The effects of H₂O₂ and IPA addition on diluted H₂SO₄ were observed below 30 vol% of H₂SO₄. The thickness of PR was increased with the addition of H₂O₂ to the solutions and the strip rate was increased when IPA was added. Silica particles were used to evaluate particle removal efficiency. The concentration of HF was the predominant factor of increasing PRE, and the addition of H₂SO₄ and H₂O₂ assisted in obtaining high PRE, while IPA addition reduced PRE. Decreasing of contact angle was observed with an increase of IPA addition to DSP⁺ solutions, and improved wettability of DSP⁺ solutions was expected to effectively clean particles in high-aspect-ratio (HAR) contact holes.

Abstract: Water scarcity is growing and in particularly in regions where population is high. It is estimated by world wild life organization that two thirds of human population may face water shortage by 2025. However, the amount of water available on earth covers approximately two thirds of the total surface area, but most of the water is seawater. Seawater cannot be used for any human use due to the high salinity levels. Desalination processes have been implemented on various scales whereby reverse osmosis is the most successful. However, such system is too complex and expensive. An alternative system utilizing humidification-dehumidification process for desalination is proposed in this paper. The process involves the use of a novel hydrophobic membrane allowing the humidification. Two configurations have been tested in a closed loop cycle, namely: static and moving membrane. The results from the experiments have shown that the efficiency of the moving membrane configuration is higher than the static by 46%. And based on 1 Litre brine feed, 50% of the volume has been successfully desalinated.

Abstract: Coloured solders offer wide range of possible application on top of conventional usage related to solder and soldering. Coloured solder can be produced by adding colour pigment into solder formulation to form coloured solder composite. The performance of coloured solder joint typically determined by good solderability, which influenced by wetting properties. The objectives of this paper is to investigate the solderability of coloured lead free solder composite with different formulation type of colour pigment and variation of colour pigment composition. Green and “glow in the dark pigment” with composition of 5% and 10% respectively were added into the lead free solder paste. Each coloured solder paste was stencil printed on the PCB and then reflowed using reflow soldering process. The wettability of the solder composite was measured and observed using Infinite Focus Measurements (IFM). The results demonstrated that coloured lead free solder composite have a good wettability. This finding also indicates that use of green pigment into the solder composite has shown greater wettability as compared to glow in the dark pigment. Higher percentage of added colour pigment of 10% has significantly reduced the wettability of solder composite. Wettability of coloured solder composite with small amount of added pigment is in the acceptable range of contact angle, showing good solderability of joining.

Abstract: The surface wettability of biomaterials influences on osteoblast behavior and bone formation. In this research, the variation of wettability of nacre by heat treatments was examined. Plates of the nacre were fabricated from shells of the Akoya pearl oyster. The specimens were heated at 100, 200, 300, 400, 500, and 600 °C. Characterizations of the specimens during and after heat treatments were carried out using scanning electron microscopy, X-ray diffractometry, and thermogravimetry-differential thermal analysis. The water contact angle (WCA) of the specimen was measured to evaluate wettability. The color of nacre changed from iridescent color to brownish weak-iridescence by the heating at and over 300 °C. The nacre heated at and over 300 °C became brittle because organic substances in nacre, which acts as the glue between the aragonite platelets were evaporated by the heating. The WCA of the specimen was decreased with increasing heating temperature, which should be related to the decrease in the number of organic substances in nacre by the heating.

Abstract: Surface wettability is thought to influence the osteoconductivity of bone-substituting materials; however, the effects of surface wettability on osteoblast behavior are not well understood. In this study, we prepared both an as-polished pure titanium with a water contact angle (WCA) of 57° and heat-treated pure titanium with more hydrophobic surface and WCAs of 68°-98°. The effects of the surface wettability of pure titanium on osteoblast behaviors were evaluated by in vitro assays. Compared with the as-polished titanium, the proliferation rate of osteoblast increased on heat-treated titanium. This suggested that surface wettability affects osteoblast behaviors, meaning osteoconductivity is influenced by surface wettability.