WO₃-Based Slippery Liquid-Infused Porous Surfaces with Long-Term Stability

Abstract

Slippery liquid-infused porous surfaces (SLIPS) inspired by Nepenthes pitcher plants exhibit excellent hydrophobicity, antifouling and anti-icing properties, and long-term durability under pressure and temperature. SLIPS have potential applications including in biomedical devices, self-cleaning structures, and water-resistant coatings. A big challenge posed by SLIPS is the durability of the lubricant in the porous layer. Herein, uniform tungsten oxide nanofiber networks were synthesized on the surface of stainless steel through a simple one-step hydrothermal method. WO3 nanofiber networks on stainless steels were chemically modified, filled with a lubricant, and prepared as SLIPS with excellent liquid repellency and good anti-biofouling properties. The relationship of the nanostructures and the slippery properties of the obtained WO3-based SLIPS have been investigated in detail in this work. The liquid retention and long-term stability of the SLIPS were characterized using high shear force and water flow impact. We found that the long-term durability of the SLIPS is strongly related to the diameters and the Brunauer–Emmett–Teller surface areas of the WO3 nanostructures. The durability of the SLIPS is better when the diameter of the WO3 nanostructures is smaller. The WO3-based SLIPS prepared in this work exhibit outstanding slippery property, anti-biofouling, and long-term stability under extreme conditions such as high shear rate and water washing and thus may have potential application for surface modification of medical devices in the future.

Enhanced condensation heat transfer using porous silica inverse opal coatings on copper tubes

“…We attribute the improvements in heat transfer rate in SLIPS to smaller departure radius and higher departure frequency of falling droplets when compared to DWC. The solid–liquid composite material design in SLIPS improved droplet mobility (≈ 1–2° contact angle hysteresis) by providing an atomically smooth and chemically homogeneous liquid–liquid interface 65 , 66 . We validated our measurements by comparing the heat transfer coefficient for FWC on a smooth oxygen plasma treated copper tube with the classical Nusselt model (Supporting Material Section S5 , Fig.…”

Design of Lubricant-Infused Surfaces Based on Mussel-Inspired Nanosilica Coatings: Solving Adhesion by Pre-Adhesion

“…The SLIPS samples (1 cm × 1 cm) were stuck at the center of a spin coater and spun at a spin rate of 1000–8000 rpm for 5 min. The weight loss percentage, water contact angle, and sliding angle (SA) were calculated after each shear test …”

“…The weight loss percentage, water contact angle, and sliding angle (SA) were calculated after each shear test. 37 2.4. Anti-Adhesion of SLIPSs.…”

Material Strategies for Ice Accretion Prevention and Easy Removal

“…To avoid the drain of lubricating liquid, the weak van der Waals forces between lubricant molecules and solid surface was replaced by relatively strong interaction, such as π-electron, π-OH, and electrostatic interaction and covalent bonding. , PDMS chains were usually used to prepare slippery surfaces because of its low-cost and hypotoxicity. The PDMS molecules acting as side chains were grafted to main chains and aggregated to form the cores of PDMS chains micelles; then, they were assembled on the coating surface to present excellent slipping and deicing characteristic. − Recently, our group also designed a kind of organic–inorganic hybrid SLIPS coating that was capable of enduring not only organic solvent washing but also ten thousands of mechanical friction by importing inorganic interlayer. , To solve the fragility of polymeric porous substrate, many hard metal alloy, ,, aluminum oxide, , inorganic minerals particles, etc. , were used as porous substrate to build robust SLIPS. Because of the abundant low surface energy lubricants in the extreme hardness substrates, these SLIPS materials were able to keep relatively low ice adhesion after repetitive icing–deicing cycles, as well as endure mechanical wear even under harsh sandpaper friction.…”

“…138−140 Recently, our group also designed a kind of organic−inorganic hybrid SLIPS coating that was capable of enduring not only organic solvent washing but also ten thousands of mechanical friction by importing inorganic interlayer. 141,142 To solve the fragility of polymeric porous substrate, many hard metal alloy, 124,143,144 aluminum oxide, 145,146 inorganic minerals particles, etc. 147,148 were used as porous substrate to build robust SLIPS.…”