141 research outputs found
Special Issue on Superhydrophobic coatings for corrosion and tribology
No full textSuperhydrophobicity, showing strong water-repellency, has been widely investigated for many applications, especially in the fields of corrosion protection and antifouling. Water tends to roll off from superhydrophobic surfaces like natural lotus leaves. When a corrosive aqueous solution comes into contact with such a surface, a stable air cushion is formed on the interface between liquid and solid which minimizes the contact area. As a result, the charge transfer of the corrosive reaction is dramatically restrained, resulting in a positively shifted corrosion potential and low corrosion rate. Additionally, the superhydrophobic surface effectively isolates microorganisms from adhering on the surface and thus prevents microbiologically influenced corrosion caused by their metabolites. Thus, the superhydrophobic coatings have potential applications in corrosion protection of marine equipment, medical devices, mechanical components, etc.However, the lack of mechanical strength and heat resistance prevents the use of these coatings in harsh environments. It is well established that micro-nano hierarchical structures and low surface energy are the two fundamental factors crucial to developing superhydrophobic surfaces, and the superhydrophobicity of these surfaces would be diminished if they were destroyed by abrasion or overheating. The superhydrophobic coatings using wear-resistant inorganic materials are therefore highly sought after. Ceramics are of particular interest due to their high mechanical strength, heat and corrosion resistance. Such superhydrophobic coatings have recently been successfully fabricated using a variety of ceramics and different approaches, and have shown improved wear and tribocorrosion resistance properties.This special issue is making the best effort to reflect the recent developments in the fabrication of superhydrophobic coatings and their robustness against corrosion and wear resistance. We hope it will stimulate the future research and application
One-step electrodeposition of a self-cleaning and corrosion resistant Ni/WS2 superhydrophobic surface
No full textSuperhydrophobic surfaces have been intensively investigated for applications requiring self-cleaning and corrosion resistance. The techniques used to fabricate such a coating tend to be costly, time and energy consuming; further surface modification steps are often needed. In this study, a superhydrophobic composite electrodeposit based on tungsten disulphide nanoparticles dispersed in nickel on a mild steel substrate was successfully developed. At room temperature, the deposit showed a water contact angle of 158.3 deg and a sliding angle of 7.7 deg. The effects of operational parameters on surface morphology and superhydrophobicity are discussed. Compared to the substrate, the robust surface of the as-prepared coatings exhibited good self-cleaning and corrosion resistance, providing potential for industrial applications
Robust Ni/WC superhydrophobic surfaces by electrodeposition
No full textSuperhydrophobic, water repellent surfaces have attracted much attention but poor surface mechanical properties have limited their wider practical application. Robust surfaces based on nickel-tungsten carbide composite coatings have been electrodeposited. The surfaces showed superhydrophobicity after being modified by stearic acid. The maximum contact angle of water was 164.3 degrees with a sliding angle close to zero degree. By controlling deposition conditions, versatile coatings have been produced and the effects of morphology on wettability are discussed. Coating texture has been analyzed by X-ray diffraction. The surfaces showed excellent abrasion resistance and water-repellence
Electroplating of non-fluorinated superhydrophobic Ni/WC/WS<sub>2</sub> composite coatings with high abrasive resistance
No full textWeak hierarchical rough structures on superhydrophobic surfaces hinder their practical industrial applications. This paper reports a strategy to fabricate robust nickel-based superhydrophobic coatings via the codeposition of nanosized WS2 and WC particles. The Ni/WC/WS2 composite coatings were synthesized on mild steel substrates by one-pot electroplating followed by the adsorption of stearic acid self-assembled monolayers to modify the surface wetting. The particle concentration in the bath was investigated and the maximum water contact angle of approx. 170° was achieved by optimizing the particle contained. Hardened by WC and lubricated by WS2 inclusions the superhydrophobic coatings showed remarkable abrasive resistance with a bearing capacity ≥10,000 mm abrasion length. The coatings also showed aerophilic behavior and good environmental stability over >6 months
Tragverhalten von randfernen Kopfbolzenverankerungen bei Betonbruch
No full textSIGLEAvailable from TIB Hannover: RO 5280(1994,1) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
Clinical study on combined acupuncture and speech rehabilitation in treating postapoplectic aphasia
No full textSuperhydrophobic Coatings for Corrosion and Tribology
No full textSuperhydrophobic surfaces, with a water contact angle >150°, have attracted both academic and industrial interest due to their wide range of applications, such as water proofing, anti-fogging, antifouling, anti-icing, fluidic drag reduction and anti-corrosion. Currently the majority of superhydrophobic coatings are created using organic chemicals with low surface energy. However, the lack of mechanical strength and heat resistance prevents the use of these coatings in harsh environments. Quality superhydrophobic coatings developed using inorganic materials are therefore highly sought after. Ceramics are of particular interest due to their high mechanical strength, heat and corrosion resistance. Such superhydrophobic coatings have recently been successfully fabricated using a variety of ceramics and different approaches, and have shown the improved wear and tribocorrosion resistance properties. This Special Issue focuses on the recent developments in the fabrication of superhydrophobic coatings and their robustness against corrosion and wear resistance, but the original work on other properties of superhydrophobic coatings are also welcome. In particular, the topics of interest include, but are not limited to: Robust superhydrophobic coatings; Coatings with super-wettability in multifunctional applications; Wetting effects on corrosion and tribology; Hierarchical Coating for wetting and modelling
H<inf>∞</inf> filtering for a class of singular stochastic time-delay systems
No full textThe Development of Color Quantitative System of Farm Product Based on the Chromaticity Theory
No full textDesign and realization of fluxgate sensor signal processing unit
No full textThis paper firstly discusses the magnetic fluxgate sensor's principle of work, then conducts an in - depth analysis to the magnetic fluxgate sensor output signal from the aspect of its mathematical model, the paper proposes the second harmonic detecting method. In this way, the paper gives the implementation plan for the fluxgate magnetometer, and complete signal detection and processing circuit design of the closed - loop fluxgate sensor. The circuit modulates the fluxgate signal into direct voltage signals of a characterization of magnetic field size by resonance, second harmonic amplification, band - pass filtering and phase - check spread of second order Butterworth low - pass filter. To improve the dynamic performance of a magnetic field measurement and temperature stability, closed - loop circuit uses digital PID control method
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