Polydimethylsiloxane Brushes Research Articles

Smart anti‐fouling and self‐repairing polymer brushes for efficient oil–water separation

AbstractThe increasing water pollution problem poses a demand for oil–water separation materials, but preparing separation materials with high efficiency and excellent durability remains a great challenge. In this work, we use a diblock polymer brush of polydimethylsiloxane (PDMS) and poly(N,N‐dimethylaminoethyl methacrylate) (PDMAEMA) based on cotton fabric to prepare oil–water separation membranes with high efficiency, good durability, and intelligent self‐repairing properties. Lubricating PDMS brushes reduces the fouling adhesion due to its low surface energy and high flexibility. pH‐responsive PDMAEMA brushes provide good hydrophobicity and an intelligent self‐repairing effect. The prepared Co‐PDMS‐PDMAEMA has high oil flux (>30,000 L m−2 h−1) and high separation efficiency (>99%) even after 10 cycles and its surface character can be recovered under acidic conditions. Overall, the modified cotton fabric made by such a versatile technique is promising in oil–water separation.

Light-induced manipulation of ultra-low surface tension droplets on stable quasi-liquid surfaces

HypothesisPerfluorocarbon is commonly used as a coolant, chemical reaction carrier solvent, medical anti-hypoxic agents and blood substitutes. The realization of non-contact complex manipulation of perfluorocarbon liquids is urgently needed in human life and industrial production. However, most liquid-repellent interfaces are ineffective for the transport of ultra-low surface tension perfluorocarbon liquids, and struggle to maintain good durability due to unstable air or oil cushions in the surface. Therefore, preparing surfaces for stable non-contact complex manipulation of ultra-low surface tension droplets remains a challenge. ExperimentsIn this paper, a novel solution, a photothermal responsive droplet manipulation surface based on polydimethylsiloxane brushes, has been reported. On this surface, droplets with different surface tensions (as low as 10 mN/m) can be efficiently manipulated through induced near-infrared light. Notably, this surface maintains its effectiveness after exposure to extreme anthropogenic conditions. FindingsThe interface effect between perfluorocarbon droplets and polydimethylsiloxane brushes by near-infrared light-induced was investigated in detail. In addition, ultra-low surface tension droplets demonstrate the ability to transport solid particles. The conductive droplets exhibit sophisticated manipulation realizing the controlled switching of smart circuits. This research opens up new possibilities for advancing the capabilities and adaptability of ultralow surface tension droplets in a range of applications.

Robust Transparent Photothermal Omniphobic Coating for Efficient Anti/Deicing and Antifogging.

Icing and fogging on optical material surfaces bring various problems in daily life. Recently, some photothermal coatings have been reported to prevent the condensation or freeze of water droplets by increasing the surface temperature. However, it is a great challenge to apply them in practical conditions due to their opaqueness and poor mechanical wear-resistant property. In this work, we constructed a robust transparent photothermal omniphobic coating with a simple dip-coating technique. In the coating system, photothermal polypyrrole nanoparticles are introduced into inorganic silica networks, and then polydimethylsiloxane (PDMS) brushes were grafted on the inorganic silica layer to endow the surface with omniphobicity and stain resistance. The transparency and photothermal capacity of the coating can be regulated by the deposition times of the coating. In addition, the coating has an excellent anti/deicing property and reduces ice adhesion obviously due to the existence of "liquid-like" PDMS brushes. More importantly, the coating presents outstanding mechanical wear-resistant and self-lubricating properties that can endure several thousand friction cycles without performance loss. The mechanically robust photothermal omniphobic coating gives a feasible approach to anti-icing and antifogging of transparent substrates under sunlight irradiation.

Durable daytime radiative cooling achieved by super-slippery coatings containing polydimethylsiloxane brushes

Radiative cooling technology is an effective method for mitigating global warming and the urban heat island effect. It achieves cooling through self-radiation and reflection solar energy without consuming energy. However, preparing a long-lasting and durable radiative cooling material remains a challenge. Here, we prepared a super-slippery radiative cooling (SSRC) coating with self-cleaning capability and mechanical stability for future large-scale and long-lasting applications of radiative cooling. The coating containing epoxy, polydimethylsiloxane (PDMS) brushes, and TiO2 exhibit high solar reflectance and infrared emissivity. Especially, the surface microstructures of the coatings enhance the emissivity in the atmospheric window. The high solar reflectivity (90 %) and infrared emissivity (93 %) of the SSRC coatings ensure effective cooling, with coatings on metal surfaces cooling down to an average of 10.4 °C outdoors. For the fruit preservation, the SSRC coating can even extend the shelf life of fruits by up to 10 days. More importantly, due to the low surface energy and high mobility of PDMS brushes, the coating exhibits excellent super-slippery and self-cleaning performances. Water and oil can easily slide on the surface of the SSRC coating. This approach prevents the coverage of contaminants, which is crucial for using radiative cooling coatings outdoors. Furthermore, the SSRC coating exhibits exceptional mechanical stability and can maintain a consistently low coefficient of friction during a 5-hour tribological test. After being impacted with water and sand outdoors for a long time, the coating retains its cooling and self-cleaning properties. Such durable and self-cleaning radiative cooling coating has potential for future applications in thermal management.

Thickness of Nanoscale Poly(Dimethylsiloxane) Layers Determines the Motion of Sliding Water Drops.

Layers of nanometer thick polydimethylsiloxane (PDMS) are applied as hydrophobic coatings because of their environmentally friendly and chemically inert properties. In applications such as heat exchangers or fog harvesting, low water drop friction on surfaces is required. While the onset of motion (static friction) has been studied, the knowledge of dynamic friction needs to be improved. To minimize drop friction, it is essential to understand which processes lead to energy dissipation and cause dynamic friction? Here, the dynamic friction of drops on PDMS brushes of different thicknesses is measured, covering the whole available velocity regime. The brush thickness L turns out to be a predictor for drop friction. 4-5nm thick PDMS brush shows the lowest dynamic friction. A certain minimal thickness is necessary to form homogeneous surfaces and reduce the attractive van der Waals interaction between water and the substrate. The increase in dynamic friction above L = 5nm is also attributed to the increasing viscoelastic dissipation of the capillary ridge formed at the contact line. The height of the ridge is related to the brush thickness. Fluorescence correlation spectroscopy and atomic force measurements support this interpretation. Sum-frequency generation further indicates a maximum order at the PDMS-water interface at intermediate thickness.

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 18.4kPa. 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.

Long-Term Stable Superlubricity Coatings Enabled by the Interaction between the Polydimethylsiloxane Brush and Silicone Oil.

Recently, materials with superlubricity captured widespread attention on account of their great potential in energy savings and environmental protection. However, certain issues still remain to be solved for the traditional materials, such as the dependence on strict conditions and an unstable superlubricity state. Herein, a long-term stable superlubricity coating was prepared using a low-cost and simple method via an epoxy-based coating with polydimethylsiloxane (PDMS) brushes under silicone oil (SO) lubrication conditions. Compared with the pure epoxy resin matrix, the friction coefficient and wear track width of the superlubricity coating with the optimal amount of 6 wt % PDMS are reduced to 0.006 and 50.9 μm (reduced by 10-fold and 5.6-fold decrease, respectively). In addition, the coating can maintain a stable superlubricity state during a 5 h tribological test. The superlubricity of the coating results from the synergistic lubrication effect of the PDMS brush and SO. First, PDMS brushes with high-stretched conformation due to the swelling effect of the SO can significantly reduce friction. Second, a stable oil film is generated between the contact surfaces, which significantly improves the frictional performance. Moreover, the PDMS incorporated into the coating matrix, along with oil-swelling PDMS brushes on the surface, is highly beneficial for enhancing corrosion resistance of the epoxy resin matrix. Such an epoxy-based coating with long-term stable superlubricity is considered as a potential lubricating and protective surface for tribological components for long-term service.

Durable, Ultrathin, and Antifouling Polymer Brush Coating for Efficient Condensation Heat Transfer.

Heat exchangers are made of metals because of their high heat conductivity and mechanical stability. Metal surfaces are inherently hydrophilic, leading to inefficient filmwise condensation. It is still a challenge to coat these metal surfaces with a durable, robust, and thin hydrophobic layer, which is required for efficient dropwise condensation. Here, we report the nonstructured and ultrathin (∼6 nm) polydimethylsiloxane (PDMS) brushes on copper that sustain high-performing dropwise condensation in high supersaturation. Due to the flexible hydrophobic siloxane polymer chains, the coating has low resistance to drop sliding and excellent chemical stability. The PDMS brushes can sustain dropwise condensation for up to ∼8 h during exposure to 111 °C saturated steam flowing at 3 m·s-1, with a 5-7 times higher heat transfer coefficient compared to filmwise condensation. The surface is self-cleaning and can reduce the level of bacterial attachment by 99%. This low-cost, facile, fluorine-free, and scalable method is suitable for a great variety of heat transfer applications.

A robust dynamic dewetting coating with omniphobicity, wear resistance, and scratch repairability

Dynamic dewetting coatings (DDCs) with robust structure and omniphobicity are difficult to prepare, and problems such as fragility, easy failure, and short service life hinder their practical applications. Herein, a DDC with omniphobicity, wear resistance, and scratch repairability was prepared by introducing polydimethylsiloxane (PDMS) brushes and polytetrafluorowax (PFW) into the cross-linking network of epoxy. The PDMS brushes are introduced to the cross-linking network by the grafted reaction with polyamidoamine containing 128 NH2 end groups, and then the solidification of the NH2 groups and the epoxy groups. As a result, the prepared coating exhibited excellent omniphobicity to various liquids with different surface energies and viscosities such as water, hexadecane, and sunflower seed oil. Particularly, the contact angle of ethanol (10 μL) on the coating was 13.5 ± 1.0°, and its sliding angle was as low as 6.4 ± 0.7°. Relying on the effect of “liquid lubricant” PDMS brushes and “solid lubricant” PFW, the DDC exhibited excellent tribological properties with friction-reducing and wear resistance. Moreover, the PFW in the coating could experience a solid-to-liquid transition at a specific temperature and flow to the damaged region for repairing effect. Scratches made with a friction tribometer, a knife, or sandpaper on the DDC can be easily repaired by heating, and the repaired coating still had outstanding omniphobicity. Long-term dynamic dewetting stability, excellent stability, and scratch repairability enable the practical application of the prepared DDCs.

Molecularly Capped Omniphobic Polydimethylsiloxane Brushes with Ultra-Fast Contact Line Dynamics.

Droplet friction is common and significant in any field where liquids interact with solid surfaces. This study explores the molecular capping of surface-tethered, liquid-like polydimethylsiloxane (PDMS) brushes and its substantial effect on droplet friction and liquid repellency. By exchanging polymer chain terminal silanol groups for methyls using a single-step vapor phase reaction, the contact line relaxation time is decreased by three orders of magnitude-from seconds to milliseconds. This leads to a substantial reduction in the static and kinetic friction of both high- and low-surface tension fluids. Vertical droplet oscillatory imaging confirms the ultra-fast contact line dynamics of capped PDMS brushes, which is corroborated by live contact angle monitoring during fluid flow. This study proposes that truly omniphobic surfaces should not only have very small contact angle hysteresis, but their contact line relaxation time should be significantly shorter than the timescale of their useful application, i.e., a Deborah number less than unity. Capped PDMS brushes that meet these criteria demonstrate complete suppression of the coffee ring effect, excellent anti-fouling behavior, directional droplet transport, increased water harvesting performance, and transparency retention following the evaporation of non-Newtonian fluids.

Enhanced condensation heat transfer by water/ethanol binary liquids on polydimethylsiloxane brushes

AbstractEnhancing heat transfer efficiency by liquid condensation plays a critical role in recovering and utilizing low‐grade heat. However, overall heat transfer efficiency is commonly limited by the inefficient vapor–liquid phase transition flux and enthalpy during liquid condensation. Here, we report that by introducing small amount of water into the phase‐change process of ethanol on a liquid‐like polydimethylsiloxane (PDMS) brush surface, the heat transfer coefficient is significantly enhanced, in particular, by more than one order of magnitude compared to the pure ethanol condensation. Such enhanced thermal performance is primarily due to the elaborate balance between promoting condensation, that is, nucleation and growth, and increasing latent heat by regulating components of water and ethanol, as well as the rapid droplet removal by condensing on the PDMS brushes. Note that the more stabilized dropwise condensation of the binary liquids, retained by accelerating the droplet coalescence velocity, beyond filmwise condensation ensures its significant effectivity under high heat flux.

Polydimethylsiloxane brushes and the search for extraterrestrial life

The low temperature and high pressure tribological properties of polydimethylsiloxane brushes with ice are explored to demonstrate their feasibility as an exterior coating for an off-world cryobot. Successful deposition of the brushes on silicon and glass was confirmed with a contact angle hysteresis < 2° and a surface roughness below 1 nm. The friction factor of the brushes roughly doubled when the temperature was lowered from +20 °C to −20 °C, but it decreased by 55% when the normal force was increased from 0.5 N to 16 N. When sheared, adhered ice slid on the brushes at a shear stress around 21 kPa, and this did not increase with an additional normal pressure of up to 98 kPa. A glass rod coated with the brushes served as a cryobot surrogate and was frozen within cores of −10 °C ice 1–3 cm high. Weight attached to the rod enabled it to cleanly slide completely through the ice cores at the ambient −10 °C, i.e. without melting the ice. Together, these results indicate that polydimethylsiloxane brushes may be a feasible exterior coating for an off-world cryobot that would enable it to slide through the frozen surface of potentially life-harboring bodies such as Europa or Enceladus, avoiding the need to melt the entire cryobot’s exterior.

A mechanically robust slippery coating for anti-corrosion, Photothermal deicing, and anti-sticking applications

The preparation of slippery coatings suitable for various environments with good mechanical strength and stability is challenging. Here, we used polydimethylsiloxane (PDMS), epoxy resin (EP), and polydopamine/reduced graphene oxide (PDA/rGO) to prepare mechanically robust slippery coatings with stable water-repellency. Monoglycidyl ether-terminated polydimethylsiloxane and diglycidyl ether-terminated polydimethylsiloxane were covalently grafted into the EP crosslinked skeleton and enriched on the coating surface to form a dense PDMS brushes layer. Since PDMS brushes with high fluidity and low surface energy were firmly grafted onto the EP network, the prepared coating exhibited a sliding angle to water droplets as low as 4° and showed very low sliding angles for different aqueous liquids. The addition of PDA/rGO enhanced the strength of the crosslinked EP network, providing more grafting sites for the PDMS brushes, and effectively reducing phase separation. The wear resistance and corrosion resistance of the coating were also dramatically improved, and the average friction coefficient was only 0.044 during a 5-h tribological test. Furthermore, the slippery coating displayed outstanding photothermal deicing and anti-sticking performances. With its multifunctionality and scalability, the EP/PDMS/rGO coating is promising for practical applications in the field of hydrophobic materials.

Crosslinking inert liquidlike polydimethylsiloxane brushes using bis-diazirine chemical insertion for enhanced mechanical durability

Inert polymer brushes offer excellent omniphobic and antifouling properties but enhancing their durability remains a challenge, since their chemical inertness also means they lack the functionality necessary for traditional crosslinking reactions. We report the crosslinking of nanoscale polydimethylsiloxane (PDMS) brushes on surfaces through a chemically non-destructive C–H insertion. bis-Diazirine crosslinkers are employed to covalently link methyl groups (i.e., insertion into Si–C–H bonds) along neighboring PDMS chains upon thermal activation. The successful crosslinking of PDMS brushes is evidenced directly by X-ray photoelectron spectroscopy analysis and indirectly through mechanical durability characterization using Martindale abrasion. The apparent contact angles and low contact angle hysteresis of crosslinked PDMS brushes are well-maintained post abrasion, indicating enhanced mechanical durability as compared to uncrosslinked brushes. The longevity of the liquidlike character of crosslinked PDMS brushes is also improved following mechanical wear, with a shear ice adhesion strength half that of uncrosslinked brush surfaces. The crosslinked surfaces are also resistant to acid corrosion, heating, sonication, and tape peeling, indicating that the physicochemical stability of PDMS brushes is not degraded upon crosslinking. Finally, crosslinked brushes are additionally deposited on polycarbonate substrates, and the optical transparency, enhanced durability, and droplet shedding capability of the coated substrates are demonstrated. Overall, this study provides a new pathway for the design of durable inert nanoscale coatings that maintain their attractive surface properties after mechanical wear.

Liquid-like layer coated intraocular lens for posterior capsular opacification prevention

While intraocular lens (IOL) implantation is the only effective treatment for vision restoration in cataract patients, it is always suffering from the related complications after surgery. A leading post-implantation complication, posterior capsule opacification (PCO), is induced by the adhesion and proliferation of residual lens epithelial cells (LECs) on the IOL surface and posterior capsule. In recent years, various surface modified IOLs have been developed to reduce the incidence of PCO, however, these IOLs are rarely resistant to biofouling while maintaining close contact with the posterior capsule. This study reports a complex surface-functionalized hydrophobic acrylic IOL, namely (NT+LLL)-IOL, which can effectively prevent intraocular inflammation and the development of PCO. The surface of the hydrophobic IOL was functionalized with nanotopography and covalently conjugated with “liquid-like” polydimethylsiloxane brush. The (NT+LLL)-IOL was capable of inhibiting intraocular inflammatory responses triggered by bioadhesion and preventing residual LECs migration-induced PCO. Furthermore, the (NT+LLL)-IOL possessed advantages of optical transparency, excellent biocompatibility, and mechanical robustness despite the liquid-like layer coating. After in vivo implantation for 60 days, the (NT+LLL)-IOL could maintain optical properties by inhibiting intraocular inflammation, fibrous LEC proliferation, and further PCO occurrence, in contrast to the pristine IOLs which were prone to induce PCO after implantation. This technology provides a promising opportunity to develop an implantable IOL with reduced risks of post-operative complications and thus greatly beneficial for cataract patients.

WO3-based slippery coatings with long-term stability for efficient fog harvesting

Inspired by Nepenthes pitcher plants, slippery liquid-infused porous surfaces (SLIPSs) have attracted wide attention and exhibited remarkable liquid repellency, droplet motion control and antifouling properties. However, lubricant-impregnated surfaces have poor durability, leading to loss of control of the movements of droplets during applications. Herein, WO3-based slippery coatings with high stability were prepared by the spray method and photocatalytic reaction. Notably, on the basis of the hierarchical structures, the strong intermolecular forces between the polydimethylsiloxane brush and silicone oil led to the formation of a stable lubricant layer on the WO3-based slippery coating, which can suppress lubricant loss during water collection. After a series of stability tests, such as high-speed centrifugation, long-term storage, acidic solution and multiple heating/cooling cycles, the biomimetic slippery surface still displays excellent surface-slippery stability. Furthermore, the slippery surface exhibits superior water mist capture, water droplet expansion and harvested water removal abilities, leading to good water collection performance. The silicone oil content in the collected water was 28 mg/L, demonstrating that the loss of oil was lower during the water collection process. Even under harsh environments, including multiple heating/cooling cycles, long-term storage and high shear force, lubricant-impregnated coatings can also maintain good water collection efficiency. Therefore, these slippery coatings are promising for widespread application.

Liquid-like polymer-based self-cleaning coating for effective prevention of liquid foods contaminations

Liquid food containers commonly suffer from inevitable contamination and even biofilm formation due to the adhesion of food residuals or saliva, which requires detergents to clean. Although previously reported superhydrophobic and omniphobic coatings can resist the adhesion of liquids, the requirements of specific nanostructures or infused lubricants limit their applications in food containers. Here, by grafting smooth glass containers with “liquid like” polydimethylsiloxane brushes, we developed a unique approach for preparing a slippery coating that could exhibit highly robust repellency to various liquid foods. The coating was highly transparent and did not induce a significant alteration of the smooth surface. The “liquid like” coating could effectively prevent the adhesion of various liquid foods and inhibit the formation of bacterial biofilms, without the use of detergents for cleaning. Moreover, this coating could resist mechanical damage from friction, and displayed high biocompatibility with biological cells. The slipperiness, smoothness, robustness and biocompatibility of the “liquid like” coating was highly beneficial to practical applications as self-cleaning glass container, which has been challenging to achieve by conventional superhydrophobic or omniphobic coatings. Our study introduced a versatile strategy to functionalize biocompatible surfaces for food containers which reduced the contamination of residues and the use of detergents, and may be beneficial to human and environmental health.

Design and experimental studies of self-healable anti-corrosion coating: Passivation of metal surfaces by silicone oil impregnated porous oxides

Oil-impregnation into a hydrophobized porous surface structure effectively enhances corrosion resistance of metallic materials. In this study, an anti-corrosive silicone oil-impregnated porous oxide layer without hydrophobic coating (i.e., low surface energy materials) was created on metal surfaces. Various surface porous oxide layers were fabricated using magnesium alloy, stainless steel, aluminum alloy, and copper. Their corrosion resistances were compared after silicone oil-impregnation. The impregnation of silicone oil into a hydrophilic porous oxide layer followed by heat treatment lead to the formation of a polydimethylsiloxane (PDMS) brush on oxide surfaces, which enhanced the affinity with the impregnated oil and repellency to water. The silicone oil-impregnated porous oxide surfaces with PDMS brushes showed a high repellency to water, indicating inhibition of a direct contact with corrosive aqueous liquids. Hence, the corrosion resistances of the surface-treated magnesium alloy, stainless steel, aluminum alloy, and copper were significantly enhanced. In the presence of local damages, the silicone oil naturally permeated into the damaged region and the PDMS brush, which was formed by a simple heat treatment, showed the capability to repair anti-corrosion. It is believed that the results of this fundamental and practical study will provide a new approach for anti-corrosive surface finishing for metals.

Fabrication of Robust and Transparent Slippery Coating with Hot Water Repellency, Antifouling Property, and Corrosion Resistance.

Water-repellent coatings with low sliding angles for aqueous liquids are of great significance for practical applications. However, these coatings are susceptible to various types of damage during service and lose their effect. Herein, a robust and transparent slippery coating with extremely low water sliding angle was fabricated by covalently grafting polydimethylsiloxane (PDMS) brushes in a cross-linked skeleton of epoxy resin. Polyamidoamine G5.0 with 128 NH2 end groups was used as curing agent to induce the high cross-linking of the coating and the abundant PDMS brushes being grafted into it. Because of low surface energy and high mobility of PDMS brushes, the obtained coating exhibited a slippery performance for aqueous liquids (10 μL) with a sliding angle lower than 3° and a sliding speed as high as 1.16 mm/s. Even a 10 μL water droplet with temperature of 80 °C can slide off the coating at a low sliding angle (<5°). The strong intermolecular interactions of epoxy cross-linked skeleton endowed the coating with excellent physical and chemical stability. The sliding angle of the coating had no obvious change after heating at 120 °C for 100 h and placing outdoors for 7 months. The slippery performance was not affected by thumb press, knife scratching, high-speed friction, and water of different pH values. Furthermore, because of the excellent stability, antifouling performance, and corrosion resistance, the slippery coating can be applied to a variety of substrates, which makes the robust slippery coating have real potential for practical applications.

Superhydrophobic photothermal icephobic surfaces based on candle soot

Ice accumulation causes various problems in our daily life for human society. The daunting challenges in ice prevention and removal call for novel efficient antiicing strategies. Recently, photothermal materials have gained attention for creating icephobic surfaces owing to their merits of energy conservation and environmental friendliness. However, it is always challenging to get an ideal photothermal material which is cheap, easily fabricating, and highly photothermally efficient. Here, we demonstrate a low-cost, high-efficiency superhydrophobic photothermal surface, uniquely based on inexpensive commonly seen candle soot. It consists of three components: candle soot, silica shell, and polydimethylsiloxane (PDMS) brushes. The candle soot provides hierarchical nano/microstructures and photothermal ability, the silica shell strengthens the hierarchical candle soot, and the grafted low-surface-energy PDMS brushes endow the surface with superhydrophobicity. Upon illumination under 1 sun, the surface temperature can increase by 53 °C, so that no ice can form at an environmental temperature as low as -50 °C and it can also rapidly melt the accumulated frost and ice in 300 s. The superhydrophobicity enables the melted water to slide away immediately, leaving a clean and dry surface. The surface can also self-clean, which further enhances its effectiveness by removing dust and other contaminants which absorb and scatter sunlight. In addition, after oxygen plasma treatment, the surface can restore superhydrophobicity with sunlight illumination. The presented icephobic surface shows great potential and broad impacts owing to its inexpensive component materials, simplicity, ecofriendliness, and high energy efficiency.