Effective Approach to Render Stable Dynamic Omniphobicity and Icephobicity to Ultrasmooth Metal Surfaces

Abstract

Surface modifications for easy removal of liquids and solids from various metal surfaces are much less established than for silicon (Si) or glass substrates. Trimethylsiloxy-terminated polymethylhydrosiloxane (PMHS) is very promising because it can be directly immobilized covalently to a wide variety of metal surfaces by simply heating neat PMHS liquid, resulting in a film showing excellent dynamic omniphobicity. However, such PMHS films are easily degraded by hydrolytic attack in an aqueous environment. In this study, we have successfully improved the hydrolytic stability of the PMHS-covered ultrasmooth metal (Ti, Al, Cr, Ni, and Cu) surfaces by end-capping of the residual Si–H groups of the PMHS films with vinyl-terminated organosilanes, for example, trimethylvinylsilane (TMVS), through a platinum-catalyzed hydrosilylation reaction. The resulting TMVS-capped PMHS film surfaces showed significantly greater stability even after submersion in water for 6 days, with their excellent dynamic dewetting behavior toward water, toluene, n-hexadecane, and ethanol changing little. In addition, they also showed reasonable anti-icing (icephobic) properties with low ice-adhesion strength of less than 50 kPa even after 20 cycles of testing at −15 °C.

Recent Progress in Research on “Liquid-Like” Surfaces Showing Low Contact Angle Hysteresis and Excellent Liquid Sliding Behavior

“…Polymer brushes/thin films prepared by polydimethylsiloxane (PDMS) and its analogues have recently attracted much attention for their "liquid-like" surface properties [24][25][26]30,32,33,[45][46][47][48][49][50][51][52][53][54][55][56][57]. Since PDMS has an extremely low glass transition temperature (Tg: −127 °C) [58], the mobility of the polymer chains is considered to be very high even at room temperature.…”

“…Unfortunately, the resulting surfaces in water were reported to be unstable because of both hydrolysis of metal (M)-O-Si bonds and the residual Si-H groups of the PMHS films, leading to a decrease in dynamic water wettability. Very recently, Nakamura et al [57] have successfully improved the hydrolytic stability of the PMHS-covered metal surfaces by end-capping of the residual Si-H groups of the PMHS films with trimethylvinylsilane based on a Pt-catalyzed hydrosilylation reaction. The resulting sample surfaces showed not only dynamic omniphobicity but also reasonable ice-phobic properties.…”

Innovative Acrylic Resin-Hydrogel Double-Layer Coating: Achieving Dual-Anchoring, Enhanced Adhesion, and Superior Anti-Biofouling Properties for Marine Applications

“…While this method has shown promise, its applicability is limited to substrates with active hydroxyl groups on their surfaces, such as glass and ceramics [26,27]. For materials commonly used in ships, such as aluminum and steel, surface plasma treatment is required to impart anchoring activities [28,29], which is costly and not feasible for industrial applications. Moreover, the soft nature of hydrogel materials renders them susceptible to damage in the unpredictable ocean environment, exposing substrates to corrosion [9,12].…”

Design and preparation of durable anti‐icing polysilazane coatings with abrasion and UV resistance

“…Such materials must possess a hard surface to withstand abrasion, a hydrophobic structure both on the surface and inside the material structure, and also good resistance to UV aging. To date, an ideal method is the chemical reaction of the soft hydrophobic segments and rigid components 15–19 . Some rigid components such as chemical groups with large steric hindrance or short muti‐functional group segments are designed into the molecular network to improve the abrasion‐resistance property.…”

“…To date, an ideal method is the chemical reaction of the soft hydrophobic segments and rigid components. [15][16][17][18][19] Some rigid components such as chemical groups with large steric hindrance or short muti-functional group segments are designed into the molecular network to improve the abrasion-resistance property. For example, Zhou et al 15 adopted the five-membered ring structure of polynorbornene as the rigid backbone and fluorinated side chains to provide hydrophobicity.…”