Ultrafiltration Membranes with Structure‐Optimized Graphene‐Oxide Coatings for Antifouling Oil/Water Separation

Fouling of ultrafiltration (UF) membranes in oil/water separation is a long‐standing issue and a major economic barrier to their use in a broad range of applications. Currently reported membranes typically show severe fouling, resulting from the strong oil adhesion on the membrane surface and/or oil penetration inside the membranes. This greatly degrades their performance and shortens service lifetime. Here, the use of graphene oxide (GO) as a novel coating material for the fabrication of fully recoverable, UF membranes with desired hierarchical surface roughness is accomplished by a facile vacuum filtration method for antifouling oil/water separation. The combination of ultrathin, “water‐locking” GO coatings with the optimized hierarchical surface roughness, provided by the inherent roughness of the porous supports and the corrugation of the GO coatings, minimizes underwater oil adhesion on the membrane surface. Cyclic membrane performance evaluation tests revealed approximately 100% membrane recovery by facile surface water flushing, establishing their excellent easy‐to‐recover capability. The novel GO functional coatings with optimized hierarchical structures may have broad applications in oil‐polluted environments.     

Earthworm‐Inspired Rough Polymer Coatings with Self‐Replenishing Lubrication for Adaptive Friction‐Reduction and Antifouling Surfaces

Earthworms are able to pass through sticky soil without inducing stains through a self‐forming thick lubricating layer on their rough skins. To mimic this earthworm‐like lubricating capability, an attempt to create a textured structure on the surface of liquid‐releasable polymer coatings by a “breath figure” process is described herein. The resulting coatings exhibit fast and site‐specific release behavior under external triggers such as solid‐based friction. The released oil is then stabilized by the surface texture to form thick lubricating layers, reducing friction and enhancing wear resistance. Moreover, the coatings also exhibit excellent antifouling property in a sticky soil environment. Because the lubricating layer can be regenerated after consumption, the potential of this self‐replenished lubricating mechanism in preparing friction‐reduction, antiwear, and antifouling coatings used in solid‐based environments is therefore envisioned.     

Soft PVD Coatings — a new coating family for high performance cutting tools

The joint effort of a cutting tool manufacturer and a coating specialist led to the development of a soft solid lubricant based cutting tool coating (Patents pending!). It is applied by an advanced sputtering technique as a very thin uniform coating with a good adherence to the tools. It has a low coefficient of friction and a low affinity to alloy materials like aluminum, titanium and precious metals. These factors and others allow the machining at high spindle speed and feed rates with an excellent workpiece surface finish. Values can be maintained which are far superior to even those permitted for cemented carbide tools. In some cases, productivity and tool life can be increased by a factor of up to 20.     

Facile Fabrication of Eco‐Friendly Durable Superhydrophobic Material from Eggshell with Oil/Water Separation Property

Most superhydrophobic surfaces are fragile and even lose their functions under harsh conditions especially in outdoor applications. In this study, we have demonstrated a facile strategy for fabricating eco‐friendly and mechanical durable superhydrophobic material from eggshell. The as‐prepared superhydrophobic materials possess not only excellent self‐cleaning property and under oil superhydrophobicity, but also high‐efficient oil/water separation capability. More importantly, the obtained materials show outstanding and mechanical durable water repellency, which can maintain superhydrophobicity after 360 cm abrasion length of sandpaper. In addition, the materials also show durable superhydrophobic toward strong acidic/alkali solutions, UV irradiation, and water droplet impact, which demonstrates the outstanding chemical and environmental stability. This facile fabrication of the mechanical durable superhydrophobic materials and the utilization of daily garbage will provide the new ideas for engineering materials and accelerate the real application of the super‐repellent materials.

     

Self‐Defensive Coating for Antibiotics Degradation—Atmospheric Pressure Chemical Vapor Deposition of Functional and Conformal Coatings for the Immobilization of Enzymes

Conformal epoxy‐rich coatings are synthesized by plasma initiated chain‐growth polymerization of glycidyl methacrylate via a newly developed Plasma initiated chemical vapor deposition method at atmospheric pressure to provide a functional platform for the immobilization of enzymes degrading antibiotics (laccase and β‐lactamase). In addition to enhance the enzymes activity duration and intensity, surface immobilization is also leading to enzyme structure rigidification, allowing them to endure mechanical stresses generated by a laminar water flow of 30 km h⁻¹, and this with no reduction of their enzymatic activity. Self‐defensive surface properties against microorganism's adhesion, preventing the enzyme alteration and improving the degradation performances, are obtained via surface saturation with Tween 20. The developed method is scaled up to high specific surface high‐density polyethy­lene biochips commonly used in water treatment, and shows self‐defensive abilities and particularly long lasting efficient degradation properties.