F.J. Wang

Green Approach to the Fabrication of Superhydrophobic Mesh Surface for Oil/Water Separation

We report a simple and environment friendly method to fabricate superhydrophobic metallic mesh surfaces for oil/water separation. The obtained mesh surface exhibits superhydrophobicity and superoleophilicity after it was dried in an oven at 200u2009°C for 10 min. A rough silver layer is formed on the mesh surface after immersion, and the spontaneous adsorption of airborne carbon contaminants on the silver surface lower the surface free energy of the mesh. No low-surface-energy reagents and/or volatile organic solvents are used. In addition, we demonstrate that by using the mesh box, oils can be separated and collected from the surface of water repeatedly, and that high separation efficiencies of larger than 92u2009% are retained for various oils. Moreover, the superhydrophobic mesh also possesses excellent corrosion resistance and thermal stability. Hence, these superhydrophobic meshes might be good candidates for the practical separation of oil from the surface of water.

Reversible wettability between superhydrophobicity and superhydrophilicity of Ag surface

We present a facile one-step method to fabricate superhydrophobic Ag surface by electrodeposition without using any low surface energy reagent. The water contact angle of the prepared surface is 167.1° and the sliding angle is only 0.5° after heat treatment. It is demonstrated by the field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses that the dendrites of rough micro-nanostructure combined with the spontaneously adsorbed hydrocarbon make the surface exhibit superhydrophobicity. However, the superhydrophobic Ag surface becomes superhydrophilic when the surface is irradiated by UV light for several hours. It recovers superhydrophobicity after further heat treatment and can successfully implement the reversible wettability transition between superhydrophobicity and superhydrophilicity for several cycles.摘要本文采用简单的电沉积法制备出无需低表面能试剂修饰的超疏水银表面. 镀银表面经过热处理后与水滴的接触角达到167.1°而滚动角仅为0.5°. 通过FESEM, XRD以及XPS分析表明, 制备的微米/纳米级粗糙结构的银表面吸附了空气中的碳氢化合物导致表面具有超疏水性. 当用紫外光照射表面几个小时后, 表面会从超疏水性转变为超亲水性. 然而, 热处理后表面又恢复超疏水性能. 重复紫外光照射和热处理过程, 镀银表面可以实现超疏水和超亲水之间的多次转换.

Retraction Note to: Wear Mechanism for In Situ TiC Particle Reinforced AZ91 Magnesium Matrix Composites

TiC reinforced AZ91 magnesium matrix composites have been fabricated by a melt in situ reaction spray deposition. The microstructures of spray-deposited alloys were studied by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The dry sliding wear behavior of the alloys was investigated by using a pin-on-disc machine under five loads, namely 10, 20, 30, 40, and 50 N. The composites had much better wear-resistance than the matrix alloy. The wear behavior of the composites was dependent on the TiC content in the microstructure and the applied load. The improvement in the wear resistance of the composites became more prominent at larger normal load. At a lower load (10 N), with increasing TiC content, the wear rate of the composite was decreased, and the dominant wear mechanism was an oxidative mechanism. At a higher loads (50 N), a spray-deposited AZ91/TiC composites exhibited superior wear resistance to the AZ91 magnesium alloy, and the dominant wear mechanism was delamination.