Ice-Shedding Polymer Coatings with High Hardness but Low Ice Adhesion

Liquid-like Surface Chemistry Meets Structured Textures: A Synergistic Approach to Advanced Repellent Materials

Liquid-repellent surfaces have advanced significantly over two decades. While super-liquid-repellent surfaces with micro/nano-textures dominate the field, liquid-like smooth surfaces (LLSS) grafted with highly flexible molecule chains offer a compelling alternative, enabling near-ideal dynamic droplet repellency with ultralow contact angle hysteresis (CAH). Prior LLSS studies have focused on optimizing molecular structures, grafting densities, and mechanical stability, enabling applications in anti-fouling, liquid harvesting, and drag reduction. However, innovation challenges and performance bottlenecks hinder practical scalability. This review highlights a transformative approach developed in recent years: integrating liquid-like surface chemistry with structured surfaces to overcome existing limitations. We outline the key requirements for achieving liquid-like surfaces, their structure-related features and unique interface properties including low CAH, reduced adhesion, enhanced slippage, and nucleation inhibition. By synergizing liquid-like chemistry and surface textures, we categorize pioneering works into application-driven areas such as microscopic residue suppression, enhanced droplet mobility, optimized membrane separation, sustainable fabrics and condensation heat transfer. This composite strategy not only deepens fundamental understanding of liquid-like wetting mechanisms but also broadens real-world applicability. We conclude with perspectives on future challenges and opportunities, positioning this promising material system as a frontier in functional interfacial materials.

Hygroscopic Polymer Monolayers with Ultralow Ice Adhesion Strength: Investigating Factors Influencing Ice Shedding Performance

Surface-grafted hygroscopic polymer monolayers, lubricated by unfrozen water at subzero temperatures, have previously reduced ice adhesion strength (τ) on glass by up to 4-fold at -20 °C. In this study, we employ a different initiator system for surface-initiated atom transfer radical polymerization, enabling precise control over initiator and polymer grafting densities. Monolayer thickness is tuned via polymerization time and monomer concentration, and a novel method is introduced for its measurement. Systematic variation of coating type, thickness, and grafting density reveals an optimal formulation that lowers τ by 33 ± 4 times at -20 °C, an unprecedented performance for hygroscopic monolayers. These results highlight the strong potential of such coatings for ice shedding and inform the design of self-replenishing ice-shedding surfaces.

Low ice adhesion on soft surfaces: Elasticity or lubrication effects?

HYPOTHESIS

Soft materials are promising candidates for designing passive de-icing systems. It is unclear whether low adhesion on soft surfaces is due to elasticity or lubrication, and how these properties affect the ice detachment mechanism. This study presents a systematic analysis of ice adhesion on soft materials with different lubricant content to better understand the underpinning interaction.

EXPERIMENTS

The wetting and mechanical properties of soft polydimethylsiloxane with different lubricant content were thoroughly characterized by contact angle, AFM indentation, and rheology measurements. The collected information was used to understand the relationship with the ice adhesion results, obtained by using different ice block sizes.

FINDINGS

Three different de-icing mechanisms were identified: (i) single detachment occurs when small ice blocks are considered, and the ice completely detaches in a single event. In the case of larger ice blocks, the reattachment of the ice block is promoted by either: (ii) stick-slip or, (iii) interfacial slippage, depending on the lubricant content. It was confirmed that the ice adhesion strength not only depends on material properties but also on experimental conditions, such as the ice dimensions. Moreover, differently than on hard surfaces, where wetting primarily determines the icephobic performance, also elasticity and lubrication should be considered on soft surfaces.

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A Transparent Photo/Electrothermal Composite Coating with Liquid-like Slippery Property for All-Day Anti-/De-Icing

A photo/electrothermal surface can convert sunlight and electricity into heat to solve icing problems. The combination of active photo/electrothermal surfaces with passive slippery surfaces provides a highly efficient strategy for all-day anti/deicing. However, the lack of transparency remains a primary impediment to the widespread application of these anti-icing measures in photovoltaics, windshields, and other fields. Herein, we report a bilayer transparent photo/electrothermal coating with a liquid-like slippery property for all-day anti/deicing. The prepared coating exhibits ultraslippery, low ice adhesion, and enhanced stability properties through covalent grafting of polydimethylsiloxane (PDMS) brushes in a cross-linked skeleton of epoxy. Moreover, the coating demonstrates a visible transmittance of up to 77% and effectively absorbs ultraviolet and near-infrared light due to the addition of ultraviolet and infrared absorbers, resulting in a temperature increase under sun illumination. The bottom indium tin oxide layer is fabricated to provide the composite coating with electrothermal capability, so that it can achieve all-weather deicing. The coupling of photo/electrothermal and slippery properties can promote the rapid removal of grown ice in a short time. The slippery properties and their exceptional durability under mechanical, optical, and thermal conditions render the composite coatings highly promising for engineering applications.

Thermomechanically Resilient Polyionic Elastomers with Enhanced Anti-Icing Performances

Anti-icing gels inhibit ice formation and accretion; however, current iterations face prevalent drawbacks such as poor strength, weak substrate adhesion, and limited anti-icing properties. Herein, we propose a novel approach to address these challenges by developing a thermomechanical robust polyionic elastomer (PIE) with enhanced anti-icing properties. The PIE surface exhibits an icing delay time up to 5400 s and remains frost-free after exposure to -10 °C for 3.5 h, attributed to the inhibitory effect on ice formation by ions from ILs and the polyelectrolyte network. Moreover, the PIE exhibits remarkable anti-icing durability, with ice adhesion strengths below 35 kPa after undergoing 30 icing/deicing cycle tests at -20 °C. Following sandpaper abrasion (300 cycles), scratching, and heat treatment (100 °C, 16 h), the adhesion strength remains ca. 20 kPa, highlighting its resilience under various thermal and mechanical conditions. This exceptional durability is attributed to the low volatility of the IL and the robust ionic interactions within the PIE network. Furthermore, the PIE demonstrates favorable self-healing properties and strong substrate adhesion in both low-temperature and ambient environments, facilitated by the abundance of hydrogen bonds and electrostatic forces within PIE. This work presents an innovative approach to developing high-performance, durable, and robust anti-icing materials with potential implications across various fields.

Icephobic Durability of Molecular Brush-Structured PDMS Soft Coatings

The accumulation of ice can pose numerous inconveniences and potential hazards, profoundly affecting both human productivity and daily life. To combat the challenges posed by icing, extensive research efforts have been dedicated to the development of low-ice adhesion surfaces. In this study, we harness the power of molecular dynamics simulations to delve into the intricate dynamics of polymer chains and their role in determining the modulus of the material. We present a novel strategy to prepare ultralow-modulus poly(dimethylsiloxane) (PDMS) elastomers with a molecular brush configuration as icephobic materials. The process involves grafting monohydride-terminated PDMS (H-PDMS) as side chains onto backbone chain PDMS with pendant vinyl functional groups to yield a molecular brush structure. The segments of this polymer structure effectively restrict interchain entanglement, thereby rendering a lower modulus compared to traditional linear structures at an equivalent cross-linking density. The developed soft coating exhibits a remarkably ultralow ice adhesion strength of 13.1 ± 1.1 kPa. Even after enduring 50 cycles of icing and deicing, the ice adhesion strength of this coating steadfastly stayed below 16 kPa, showing no notable increase. Importantly, the molecular brush coating applied to glass demonstrated an impressive light transmittance of 92.1% within the visible light spectrum, surpassing the transmittance of bare glass, which was measured at 91.3%. This icephobic coating with exceptional light transmittance offers a wide range of applications and holds significant potential as a practical icephobic material.

De-icing performance evolution with increasing hydrophobicity by regulating surface topography

It is of great significance to grasp the role of surface topography in de-icing, which however remains unclear yet. Herein, four textured surfaces are developed by regulating surface topography while keeping surface chemistry and material constituents same. Specifically, nano-textures are maintained and micro-textures are gradually enlarged. The resultant ice adhesion strength is proportional to a topography parameter, i.e. areal fraction of the micro-textures, owing to the localized bonding strengthening, which is verified by ice detachment simulation using finite element method. Moreover, the decisive topography parameter is demonstrated to be determined by the interfacial strength distribution between ice and test surface. Such parameters vary from paper to paper due to different interfacial strength distributions corresponding to respective situations. Furthermore, since hydrophobic and de-icing performance may rely on different topography parameters, there is no certain relationship between hydrophobicity and de-icing.

A simple fabrication of liquid-like polydimethylsiloxane coating for resisting ice adhesion

The rapid realization of efficient anti-icing coatings on diverse substrates is of vital value for practical applications. However, current approaches for rapid preparations of anti-icing coatings are still deficient regarding their surface universality and accessibility. Here, we report a simple processing approach to rapidly form icephobic liquid-like polydimethylsiloxane (PDMS) brushes on various substrates, including metals, ceramics, glass, and plastics. A poly(dimethylsiloxane), trimethoxysilane is applied as a reactant under the catalysis of a minimal amount of acid formed by hydrolysis of dichlorodimethylsilane. With such an advantage, this approach is approved to be applicable of coating metal surfaces with less corrosion. The distinctive flexibility of the PDMS chains provides a liquid-like property to the coating showing low contact angle hysteresis and ice adhesion strength. Notably, the ice adhesion strength remains similar across a wide temperature window, from -70 to -10 °C, with a value of 18.4 kPa. The PDMS brushes demonstrate perfect capability for resisting acid and alkali corrosions, ultra-violet degradation, and even tens of icing/deicing cycles. Moreover, the liquid-like coating can also form at supercooling conditions, such as -20 °C, and shows an outstanding anti-icing/deicing performance, which meets the in situ coating reformation requirement under extreme conditions when it is damaged. This instantly forming anti-icing material will benefit from resisting instantaneous ice accretion on surfaces under extremely cold conditions.

Inorganic-Organic Silica/PDMS Nanocomposite Antiadhesive Coating with Ultrahigh Hardness and Thermal Stability

Antiadhesive surfaces have been gaining continuous attention, because of the scientific and industrial significance. Slippery surfaces and antismudge coatings with antiadhesive behavior have been readily designed and prepared. However, improving robustness of the surfaces, especially the simultaneous demonstration of features of high hardness, excellent adhesion to different substrates, and high thermal stability, is constantly challenging. Herein, we present a silica/polydimethylsiloxane (PDMS) nanocomposite coating (SPNC), wherein silica acts as a consecutive phase and nanophased PDMS is covalently embedded. The nanoconfined PDMS phase exhibits enhanced thermal stability and endows SPNC with slippery behavior; meanwhile, enrichment of PDMS on the surface renders a gradient composition of the coating. Accordingly, the inorganic-organic SPNC simultaneously displays a high nanoindentation hardness of 3.07 GPa and a pencil hardness over 9H, outstanding thermal stability of the slippery performance up to 400 °C, and excellent adhesion strength to different substrates. Additionally, SPNC exhibits high optical transparency, flexibility, resistance to bacterial clone, and chemical corrosion. With the scalable fabrication process, it can be envisioned that the antiadhesive coating with unprecedented comprehensive merits in this work has significant potentials for large-area applications, especially under severe service environments.

Self-healable and transparent PDMS-g-poly(fluorinated acrylate) coating with ultra-low ice adhesion strength for anti-icing applications

The high ice adhesion strength (τ) and low adhesion of lubricant-free slippery polymers have restricted their applications. We synthesized polysiloxane-g-fluorinated acrylate polymer with a branched structure, anchored groups and dynamic cross-linked network, features imparting increased chain segment slipperiness and self-healability. The coating showed a low τ (6 kPa), strong adhesion and prolonged life.

Bio-Based Waterborne Polyurethane Coatings with High Transparency, Antismudge and Anticorrosive Properties

Green and environment-friendly preparation are of the utmost relevance to the development of transparent antismudge coatings. To prepare a waterborne polyurethane (WPU) coating with antismudge property, it is challenging to balance the stability of dispersion and the antismudge property of coating. Herein, we prepare a transparent bio-based WPU coating grafted with a minor proportion of poly(dimethylsiloxane) (WPU-g-PDMS) using renewable castor oil, monocarbinol-terminated PDMS, hexamethylene diisocyanate trimer, and 2,2-bis(hydroxymethyl)propionic acid as raw materials. Effects of the dosage of monocarbinol-terminated PDMS, the curing temperature, and the curing time on the antismudge performance were studied. Results showed that rigorous stirring (3000 rpm) is necessary to obtain a stable WPU-g-PDMS dispersion with a storage time longer than 6 months. A high curing temperature (>160 °C) and a period of curing time (>1 h) are indispensable to obtain the excellent antismudge property because they would facilitate the grafted low-surface-tension PDMS chains to migrate from the interior to the coating surface. The facts that simulated contaminated liquids such as water, HCl solution, NaOH solution, artificial blood, and tissue fluid could slide off easily and cleanly, and marker ink lined on the coating surface could shrink, indicated that the WPU-g-PDMS coating has good antismudge properties, which could be self-compensated shortly after deterioration. Due to the high cross-linking degree caused by multifunctional polyol and isocyanate, the WPU-g-PDMS coating has high hardness and good anticorrosive performance. The antismudge functionalization and waterborne technology of bio-based polyurethane coatings proposed in this work could be a promising contribution to the green and sustainable development of functional coatings. This kind of WPU-g-PDMS coating is expected to protect and decorate electronic screens, vehicles, and buildings, especially endoscopes.

Omniphobic liquid-like surfaces

Liquid-repellent surfaces, especially smooth solid surfaces with covalently grafted flexible polymer brushes or alkyl monolayers, are the focus of an expanding research area. Surface-tethered flexible species are highly mobile at room temperature, giving solid surfaces a unique liquid-like quality and unprecedented dynamical repellency towards various liquids regardless of their surface tension. Omniphobic liquid-like surfaces (LLSs) are a promising alternative to air-mediated superhydrophobic or superoleophobic surfaces and lubricant-mediated slippery surfaces, avoiding fabrication complexity and air/lubricant loss issues. More importantly, the liquid-like molecular layer controls many important interface properties, such as slip, friction and adhesion, which may enable novel functions and applications that are inaccessible with conventional solid coatings. In this Review, we introduce LLSs and their inherent dynamic omniphobic mechanisms. Particular emphasis is given to the fundamental principles of surface design and the consequences of the liquid-like nature for task-specific applications. We also provide an overview of the key challenges and opportunities for omniphobic LLSs.

Effect of Doping SiO2 Nanoparticles and Phenylmethyl Silicone Oil on the Large-Scale Deicing Property of PDMS Coatings

Recently, low interfacial toughness (LIT) materials have been developed to solve large-scale deicing problems. According to the theory of interfacial fracture, ice detachment is dominated by strength-controlled or toughness-controlled regimes, which are characterized by adhesive strength or constant shear force. Here, a new strategy is introduced to regulate the interfacial toughness of poly(dimethylsiloxane) (PDMS) coatings using silicon dioxide nanoparticles (SiO₂ NPs) and phenylmethyl silicone oil (PMSO). By systematically adjusting the doping proportion of SiO₂ NPs and PMSO, it is found that a lower interfacial toughness can be achieved with a lower constant shear force. The synergistic effect of the two dopants on the adhesive strength and interfacial toughness is analyzed. Meanwhile, finite element method (FEM) analysis of ice detachment is conducted to show the cracking process intuitively and explicate the mechanism of lowering the interfacial toughness of PDMS by doping SiO₂ NPs and PMSO. It can be concluded that the cohesive zone material (CZM) model is effective for simulating the deicing process of PDMS coatings and provides a comprehensive understanding of the modulation of interfacial toughness.

Thermo-responsive Fluorinated Organogels Showing Anti-fouling and Long-Lasting/Repeatable Icephobic Properties

Accumulations of ice on modern infrastructures often cause severe consequences. As such, there is significant interest in developing functional coatings/surfaces that can prevent this. One such approach has been demonstrated with slippery liquid-infused porous surfaces (SLIPS) and organogels where the ice adhesion strength is reduced to the critical point (less than 10 kPa) where it can be removed by natural forces such as gravity, wind, vibrations, and so forth. However, both designs are limited by lubricant depletion. If lubricant release and reabsorption (syneresis) of organogels can be arbitrarily controlled by the surrounding temperature, the loss due to unfavorable evaporation and drainage of infused lubricants can be minimized and its durability can be extended. This study demonstrates the tunable thermo-responsive syneresis of transparent fluorinated organogels (F-ORGs) prepared from a commercial silicone elastomer and a lubricant mixture of fluorinated silicone oil and either poly(dimethylsiloxane) or poly(methylphenylsiloxane). By carefully tuning the ratio of the two lubricants in the mixture, the corresponding F-ORGs demonstrated arbitrarily tunable critical syneresis temperatures from -15 to 40 °C, below which the lubricant is released on the surface and above which the lubricant is re-absorbed. The resulting surfaces showed not only exceptionally long-lasting/repeatable low ice adhesion strengths (≤10 kPa over 50 icing/de-icing cycles) but also significant improvements in their repellency toward a variety of organic liquids. Compared to non-fluorinated organogels, F-ORGs could offer improved protection against outdoor pollutants to further enhance their practicality.

Synthesis of Trivinylisooctyl POSS and Its Application in UV-Curing of Polyurethane Acrylate Coatings

To improve the overall performance of polyurethane acrylic (PUAs) coatings applied to an iron or wood substrate, a modifier, trivinylisooctyl polyhedral oligomeric silsesquioxane (TVi7iso–POSS), was successfully synthesized by a polycondensation reaction in the presence of an organotin catalyst. TVi7iso–POSS is a POSS derivative possessing three olefin and seven isooctyl bonds; its molecular structure was confirmed by FT-IR, 1H-NMR, and mass spectrometry. The synthesized TVi7iso–POSS was then used as a modifier with butyl methacrylate (BMA), dodecafluoroheptyl methacrylate (DFMA), difunctional PUA (PUA–2), and photo-initiator 1173 to produce a novel polyurethane coating (PFMPUAs) via UV-curing. The performance of the obtained PFMPUAs coating was analyzed via X-ray photoelectron spectrometry, SEM, atomic force microscopy, TGA, and differential scanning calorimetry. The newly synthesized modifier, TVi7iso–POSS, enhanced the thermal stability, hardness, flexibility, impact resistance, and adhesion of the PUAs coating and maintained its good light transmittance. Moreover, the PFMPUAs coating exhibited better overall performance compared to the previously studied PUAs coating when the addition of TVi7iso–POSS and DFMA was 15 wt.% of PUA–2. Therefore, the PFMPUAs coating has potential applications in the field of environmentally friendly coatings.

Effect of Polydimethylsiloxane Oil Lubrication on the Friction of Cross-Country UHMWPE Ski Bases on Snow

Silicone oils are known for their excellent lubricating properties, low toxicity and are ice-, snow-, and hydrophobic. With the upcoming ban on fluorine-containing glide products imposed by the International Ski Federation (FIS), novel glide enhancers for skis are desperately needed. Here, the effect of four silicone oil viscosities (10, 20, 50, and 100 cSt) have been evaluated at three temperatures and snow conditions ranging from −10 °C dry snow to +5 °C wet snow. In dry snow conditions, the shear forces introduced by the silicone oil film increased friction significantly compared to a ski without any treatment. On wet snow, the increased hydrophobicity from the silicone oils reduced the friction by 10%. While commercial glide wax outperformed the silicone oils, this study reports the silicone oils do have desirable friction reducing properties for wet conditions.