Bioinspired Fatty Acid Amide‐Based Slippery Oleogels for Shear‐Stable Lubrication

Abstract

Liquid‐repellent technology is an efficient means of energy‐saving and biofouling avoidance. However, liquid‐repellent surfaces suffer from inefficient lubricant retention under shear flow and fouling problem in marine environment. Here, the authors demonstrate a fatty acid amide (FAA)‐based oleogel for stable and sustainable lubrication in marine environment. The lubrication management of marine creatures is emulated in synthetic oleogels by incorporating solid (FAA) and liquid lubricants into the molecular meshes of polymeric networks, with the nature‐derived solid lubricant providing multifunctional synergistic effects with liquid oil molecules for slippery property and remarkable anti‐biofouling. The lubricant‐confining gel achieves shear‐stable lubricity with efficient oil management. The oleogel provides continued lubrication without biofouling for approximately 4 months in marine field tests. The gel design provides a new paradigm for sustainable and shear‐stable lubrication in marine environment.

Bifunctional Amphiphilic Nanospikes with Antifogging and Antibiofouling Properties

“…For example, the bacterial coverage area on the 5 wt % OA-PEG surface was 87.2% lower than that on the 1 wt % OA-PEG surface (Figure c). The pronounced antibiofouling effect of the amphiphilic OA-PEG copolymer can be attributed to the integration of the “fouling-resistant” activity of hydrophilic PEGDMA with the “fouling-release” and “interaction-weakening” properties of slippery hydrophobic OA. ,,, Hydrophilic PEGDMA segments of the OA-PEG copolymer fundamentally prevent the bacterial attachment by forming a hydration layer. The slippery lubricating OA segments of OA-PEG copolymer promote the easy release of weakly adhered bacteria.…”

“…OA is a biologically derived antifouling material that is commonly found in organisms such as grasses, algae, and animals. , Because of its biocompatibility, OA is also widely used as a medical agent. In addition, it is the most widely used lubricating agent for increasing lubricity and reducing adhesion in industrial applications. − Thus, OA can produce slippery surfaces to which foulants either cannot firmly adhere or from which they can be readily released . However, similar to PEG, OA does not possess bactericidal properties.…”

“…Previous studies on antibiofouling materials indicate that the use of a single strategy is insufficient for the development of efficient and nontoxic anti-biofilm materials with advanced performance . Thus, the rational integration of inherent “fouling-resistant” hydrophilic PEG, “fouling-releasing” lubricating OA, and “bactericidal” nanostructures has the potential to address the limitations associated with known antibiofouling materials by combining the unique advantages of each approach. ,, Furthermore, such a hybrid strategy has the potential to endow antibiofouling materials with additional antifogging functionality. However, studies on such hybrid approaches are still nascent and these methods require further investigation.…”

“…24−26 Thus, OA can produce slippery surfaces to which foulants either cannot firmly adhere or from which they can be readily released. 27 However, similar to PEG, OA does not possess bactericidal properties. Surfaces with nanopillar arrays have emerged as nontoxic biofilm-resistant materials.…”

Sustainable Drag Reduction of Fatty Acid Amide‐Based Oleogel Surface Under High‐Speed Shear Flows

“…It is replenished when the network experiences external stimuli, such as shear force. [18] The irregular deposition of erucamide with flakier surface structures leads to a formation of nanoscale surface roughness with the aid of hydrophobic carbon chains, which always face outward the coated surface. [19][20][21] The surface roughness exhibits slippery features under the action of external shear forces.…”