One-Step Preparation of a Superhydrophobic Surface by Electric Discharge Machining with a Carbon Fiber Brush Electrode.

Superhydrophobic surfaces are extremely susceptible to damage, which can lead to a sharp decrease in their service life and physical properties. Therefore, developing methods to impart superhydrophobic surfaces with excellent wear resistance is crucial. In this article, a flexible carbon fiber brush was utilized as an electrode to fabricate micro-/nano-structures on a grooved surface via electric discharge machining in one step, resulting in a superhydrophobic coating with excellent wear resistance. Carbon fiber brushes exhibit several notable properties, including excellent flexibility, conductivity, and high temperature resistance. Carbon fiber brushes can adapt to the complex inner walls of grooves. Many nano-structures were fabricated on the grooves via pulse discharge, which resulted in a superhydrophobic surface with excellent wear resistance. The contact angle (CA) and sliding angle of the surface after discharge were 156.3 and 2°, respectively. The processed surface exhibits superior corrosion resistance compared to the stainless-steel substrate. The influence of the micro-groove shapes on wear resistance was tested. The results showed that, after 500 cm of wear, the shallow grooves retained their superhydrophobicity with a CA of 150.1°.

One-Step Preparation of Robust Superhydrophobic Foam for Oil/Water Separation by Pulse Electrodeposition.

Frequent leakage and pollution of oily wastewater seriously affect the world's ecosystem safety and economic development, which prompts us to urgently develop a highly effective, low-cost, wear-resistant, chemically stable, and environmentally friendly new functional material for oil/water separation. In this paper, a robust superhydrophobic material was successfully electrodeposited on the porous copper foam substrates in myristic acid (CH3(CH2)12COOH) and lanthanum chloride (LaCl3·6H2O) electrodeposition solution under a continuous pumping circulation and rotation condition. Moreover, SEM, EDS, XRD, FTIR, and XPS technologies were utilized to characterize the surface morphology and chemical composition information. The superhydrophobic property was evaluated by optical contact angle instrument and high-speed camera. It turned out that the micro/nanostructures were mainly composed of lanthanum myristate, and static CA of superhydrophobic copper foam (SCF) was up to 165.2° with SA ≈ 2°. Besides, the SCF exhibited a better performance with good anticorrosion, excellent chemical stability, and outstanding mechanical stability. Furthermore, the SCF can achieve up to 98.6% oil/water separation efficiency. More importantly, by employing this novel processing method, it can effectively save time and provide a promising potential way to make denser and thicker foams for continuous oil/water separation and may be easily applied to other conductive metal matrix materials.