Ice‐Shedding Endurance Enhancement of Lubricated Polyurethane NP‐GLIDE Coating Through Dual Cross‐Linking with Covalent and Hydrogen Bonds

Abstract

An NP‐GLIDE coating, featuring a liquid‐like polymer brush layer on its surface and nanopools of a grafted liquid ingredient for dewetting enablement within its matrix, is normally covalently cross‐linked (CX). This paper introduces a dually cross‐linked (DX) NP‐GLIDE coating, employing urethane bonds and H─bonds for crosslinking. Both the DX and CX coatings, utilizing poly(dimethyl siloxane) (PDMS) as the dewetting enabler, exhibit low ice adhesion strengths (τ). Post‐lubrication with silicone oil (SO), ice is readily shed under gravity from the coatings. The DX coating maintains low τ over numerous icing/de‐icing cycles, outlasting the CX coating. This durability is likely due to the lubricant‐loss‐responsive nature of the DX matrix. The matrix increases its H─bond cross‐links responding to lubricant loss and the cross‐linking density increase triggers additional lubricant release into the PDMS brush layer. This cyclic process persists over time. Under optimal conditions after 31 icing/de‐icing cycles, the lubricated DX coating demonstrates an impressively low τ of 1.8 ± 0.5 kPa. In contrast, the lubricated CX counterpart has a τ of 32 ± 11 kPa, while plain glass records a τ of 325 ± 14 kPa. This study underscores the significant potential of dual cross‐linking for enhancing ice‐shedding endurance of coatings.

Icephobic Durability of Molecular Brush-Structured PDMS Soft Coatings

“…23−26 cyclic deicing, these lubricants are susceptible to depletion, leading to their diminished efficacy. Zheng et al 27 have developed a lubricating coating with a dually cross-linked (DX) network system that combines covalent cross-linking and hydrogen bonding. By leveraging the responsive relationship between lubricating fluid and dynamic hydrogen bonds, the durability of the lubricating coating is enhanced.…”

“…By infusing lubricating liquid into the micro–nanostructures, this surface can achieve ultralow ice adhesion strength because of the high mobility of the lubricant. − However, in the process of cyclic deicing, these lubricants are susceptible to depletion, leading to their diminished efficacy. Zheng et al have developed a lubricating coating with a dually cross-linked (DX) network system that combines covalent cross-linking and hydrogen bonding. By leveraging the responsive relationship between lubricating fluid and dynamic hydrogen bonds, the durability of the lubricating coating is enhanced.…”

Synthesis of Mixed Ladder-Like Polysilsesquioxanes by Copolymerization of 2-(3,4-Epoxycyclohexyl)ethyltrimethoxysilane and Dodecyltrimethoxysilane

“…ELASQ’s application scope can be significantly expanded through functionalization. By reacting ELASQ with a limited amount of low-surface-tension perfluorinated liquid polyether (PFPE) or poly­(dimethylsiloxane) (PDMS) bearing a terminal carboxyl group, a mixture of ELASQ and a graft ( g ) copolymer ELASQ- g -PFPE or ELASQ- g -PDMS is obtained. , Casting this mixture with a cationic ring-opening initiator results in a film featuring a liquid-like PFPE or PDMS brush on its surface , and PFPE or PDMS nanopools in its matrix. − The surface brush reduces the system’s free energy, while the nanopools form due to PFPE’s or PDMS’s incompatibility with the ELASQ matrix. Photolysis of such a thin film yields an NP-GLIDE coating, − which facilitates the effortless sliding (no problem to glide) off of most daily liquids at low substrate tilt angles.…”

“…By reacting ELASQ with a limited amount of low-surface-tension perfluorinated liquid polyether (PFPE) or poly­(dimethylsiloxane) (PDMS) bearing a terminal carboxyl group, a mixture of ELASQ and a graft ( g ) copolymer ELASQ- g -PFPE or ELASQ- g -PDMS is obtained. , Casting this mixture with a cationic ring-opening initiator results in a film featuring a liquid-like PFPE or PDMS brush on its surface , and PFPE or PDMS nanopools in its matrix. − The surface brush reduces the system’s free energy, while the nanopools form due to PFPE’s or PDMS’s incompatibility with the ELASQ matrix. Photolysis of such a thin film yields an NP-GLIDE coating, − which facilitates the effortless sliding (no problem to glide) off of most daily liquids at low substrate tilt angles. The high wear resistance, bendability, and antismudge properties of ELASQ-based NP-GLIDE coatings make them ideal for use as the encapsulation layer of foldable smartphones. ,, Additionally, they exhibit significant potential as ice-shedding coatings, reducing ice adhesion strength by up to 10,000 times compared to glass, with ice falling off automatically due to weight. ,− …”

“…Photolysis of such a thin film yields an NP-GLIDE coating, − which facilitates the effortless sliding (no problem to glide) off of most daily liquids at low substrate tilt angles. The high wear resistance, bendability, and antismudge properties of ELASQ-based NP-GLIDE coatings make them ideal for use as the encapsulation layer of foldable smartphones. ,, Additionally, they exhibit significant potential as ice-shedding coatings, reducing ice adhesion strength by up to 10,000 times compared to glass, with ice falling off automatically due to weight. ,− …”