Polyacrylate-fluorosilicone block copolymers, namely, polyacrylate-b-polydimethylsiloxane and polyacrylate-bpolymethyltrifluoropropylsiloxane were synthesized for fabricating icephobic coatings. The surface morphology...Polyacrylate-fluorosilicone block copolymers, namely, polyacrylate-b-polydimethylsiloxane and polyacrylate-bpolymethyltrifluoropropylsiloxane were synthesized for fabricating icephobic coatings. The surface morphology and chemical composition of the block copolymers were characterized by atomic force microscopy and X-ray photoelectron spectroscopy, suggesting that the fluorosilicone blocks aggregated on the top of the copolymer surfaces. Results of water contact angles and ice shear strength demonstrated a certain amount adding of methacryloisobutyl polyhedral oligomeric silsesquioxane could lead to the decrease of contact angle hysteresis and increase of surface roughness, consequently resulting in significant reduction of the ice adhesion strength. Therefore, the block copolymers with the combined advantages of silicone and fluoropolymers could be potentially applied as icephobic coatings.展开更多
This paper introduces an effective anti-icing strategy that uses passive anti-icing property and active de-icing functions concurrently.These dual capabilities can alleviate the icing problem more effectively than eit...This paper introduces an effective anti-icing strategy that uses passive anti-icing property and active de-icing functions concurrently.These dual capabilities can alleviate the icing problem more effectively than either a passive or active function alone.The developed material is a slippery liquid-repellent elastic conductor(SLEC);it is an organogel that is composed of multi-walled carbon nanotubes,oil,and polydimethylsiloxane.The SLEC maintains passive water-droplet sliding ability even on wet surfaces that frequently occur in cold conditions(e.g.,during condensation and defrosting),suppresses ice nucleation,and shows ice adhesion strength as low as^20 kPa.The SLEC releases heat when it is subject to electrical or photonic stimulation,and can therefore it can prevent ice formation and melt ice that has already formed on a surface.This material has sustainable liquid repellence by syneresis and replenishment;this ability ensures long-lasting anti-icing property,and results in exceptional durability.This durability is stable against mechanical damage.The superior dual anti-icing capabilities together with the sustainable and stable liquid repellence should generate synergistic effects,and yield a powerful anti-icing tool that can broaden the range of icing applications.展开更多
Ice accumulation is a safety and operational threat in power lines,wind turbines,and transportations.Surfaces having both passive anti-icing and active deicing functionalities are very rare.Here,we report a self-clean...Ice accumulation is a safety and operational threat in power lines,wind turbines,and transportations.Surfaces having both passive anti-icing and active deicing functionalities are very rare.Here,we report a self-cleaning slippery photothermal trap,which is icephobic passively and deice the surfaces actively by converting sun light to heat at the ice-substrate interface.The photothermal trap consists of three layers:a candle soot layer act as solar radiation absorber,a magnetic iron oxide Fe_(3)O_(4) nanoparticles layer act as heat spreader for lateral dispersal of sun light,and Room Temperature Vulcanized(RTV)insulation to reduce the transverse heat loss.Upon illumination under microsolar 300,the temperature of the surface increased by 40℃ within 200 s.The heat confinement at the magnetic Fe_(3)O_(4) na-noparticles layer leads to rapid increase of the surface temperature,ice start to melt and silicone lubricant facilitates the ice removal.The slippery photothermal trap removed the frozen droplet(10 fiL)within 40 s upon the illumination of sun light and the frozen droplet was completely converted into water after 7 min illumination of solar light at-20℃.The developed slippery photothermal trap also melted the fully frost covered layer within 100 s at-20℃ under sunlamp.The average defrosted length(25 mm)was also observed by irradiation of laser light for 45 s.The self-cleaning slippery photothermal coating showed outstanding deicing performance at subzero temperature for long term due to the infusion of silicone oil into the nanostructures and same chemical composition with binder.展开更多
The aim of this study is to explore the heterogeneous ice nucleation behavior based on controllable micro-cubic array structure surfaces from the statistic perspective.To this end,we firstly constructed a group of mic...The aim of this study is to explore the heterogeneous ice nucleation behavior based on controllable micro-cubic array structure surfaces from the statistic perspective.To this end,we firstly constructed a group of micro-cubic array structures on silicon substrates by a selective plasma etching technique.After grafting low-free-energy substance,the as-constructed micro-cubic array structure surfaces exhibited higher non-wettability with the water contact angle being up to 150°.On this basis,500 cycles of freezing and melting processes were accurately recorded to analyze the instantaneous ice nucleation behavior according to the statistical results of freezing temperature.As a consequence,the statistical freezing temperature of the sample with micro-spacing distance of 40μm is as low as−17.13°C.This microstructure configuration(conforming to Cassie-Baxter wetting regime)not only could entrap more air pockets,but also achieved lower solid-liquid contact area,resulting in lower ice nucleation rate(~2–3 orders of magnitude less than that on the flat substrate).Furthermore,the gradually increasing micro-spacing distance to 60μm would induce the transition from CassieBaxter to Wenzel wetting state,leading to higher freezing probability and ice nucleation rate.The complete understanding on microstructure configuration improving the ice nucleation will lay the foundation stone for the microstructure design of ice-repellent materials.展开更多
As a ubiquitous natural phenomenon,ice/frost formation on solid surfaces have adverse effects on many commercial and residential activities.Icephobic surfaces feature low ice adhesion strengths(<100 kPa)can passive...As a ubiquitous natural phenomenon,ice/frost formation on solid surfaces have adverse effects on many commercial and residential activities.Icephobic surfaces feature low ice adhesion strengths(<100 kPa)can passively retard ice formation and ease ice removal.Superhydrophobic surfaces and liquid-lubricating surfaces are two prevailing categories of icephobic surfaces.However,their long-term stability is relatively poor,and the ice adhesion strengths are not low enough for passive removal of small ice crystals(e.g.,frosts)from the surfaces.Herein,we combine the superhydrophobic and liquid-like properties in one surface to obtain durable icephobic surfaces with extremely low ice adhesion strengths(about 0.035 kPa).Ices and frosts can be removed from the surface under the action of gravity or gas purge.These surfaces are prepared based on surface nanoconical structure and covalently-grafted liquid-like perfluorinated polyether(PFPE)coating,which show synergy effects on suppressing icing and frosting by promoting expulsion of subcooled condensate droplets from the nanotexture and decreasing ice adhesion strengths.The icephobic surfaces show significantly better durability compared to lubricant-impregnated textured surfaces.Our results provide a new avenue to design passive anti-icing/anti-frosting surfaces for a wide range of applications where surfaces are exposed to humid and low-temperature environments.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51273146 and 51103061)Natural Science Foundation of Tianjin,China(No.14ZCZDGX00008)
文摘Polyacrylate-fluorosilicone block copolymers, namely, polyacrylate-b-polydimethylsiloxane and polyacrylate-bpolymethyltrifluoropropylsiloxane were synthesized for fabricating icephobic coatings. The surface morphology and chemical composition of the block copolymers were characterized by atomic force microscopy and X-ray photoelectron spectroscopy, suggesting that the fluorosilicone blocks aggregated on the top of the copolymer surfaces. Results of water contact angles and ice shear strength demonstrated a certain amount adding of methacryloisobutyl polyhedral oligomeric silsesquioxane could lead to the decrease of contact angle hysteresis and increase of surface roughness, consequently resulting in significant reduction of the ice adhesion strength. Therefore, the block copolymers with the combined advantages of silicone and fluoropolymers could be potentially applied as icephobic coatings.
文摘This paper introduces an effective anti-icing strategy that uses passive anti-icing property and active de-icing functions concurrently.These dual capabilities can alleviate the icing problem more effectively than either a passive or active function alone.The developed material is a slippery liquid-repellent elastic conductor(SLEC);it is an organogel that is composed of multi-walled carbon nanotubes,oil,and polydimethylsiloxane.The SLEC maintains passive water-droplet sliding ability even on wet surfaces that frequently occur in cold conditions(e.g.,during condensation and defrosting),suppresses ice nucleation,and shows ice adhesion strength as low as^20 kPa.The SLEC releases heat when it is subject to electrical or photonic stimulation,and can therefore it can prevent ice formation and melt ice that has already formed on a surface.This material has sustainable liquid repellence by syneresis and replenishment;this ability ensures long-lasting anti-icing property,and results in exceptional durability.This durability is stable against mechanical damage.The superior dual anti-icing capabilities together with the sustainable and stable liquid repellence should generate synergistic effects,and yield a powerful anti-icing tool that can broaden the range of icing applications.
基金The authors would like to gratefully acknowledge the National Natural Science Foundation of China(NSFC)for Award No.21878267 for supporting this research.
文摘Ice accumulation is a safety and operational threat in power lines,wind turbines,and transportations.Surfaces having both passive anti-icing and active deicing functionalities are very rare.Here,we report a self-cleaning slippery photothermal trap,which is icephobic passively and deice the surfaces actively by converting sun light to heat at the ice-substrate interface.The photothermal trap consists of three layers:a candle soot layer act as solar radiation absorber,a magnetic iron oxide Fe_(3)O_(4) nanoparticles layer act as heat spreader for lateral dispersal of sun light,and Room Temperature Vulcanized(RTV)insulation to reduce the transverse heat loss.Upon illumination under microsolar 300,the temperature of the surface increased by 40℃ within 200 s.The heat confinement at the magnetic Fe_(3)O_(4) na-noparticles layer leads to rapid increase of the surface temperature,ice start to melt and silicone lubricant facilitates the ice removal.The slippery photothermal trap removed the frozen droplet(10 fiL)within 40 s upon the illumination of sun light and the frozen droplet was completely converted into water after 7 min illumination of solar light at-20℃.The developed slippery photothermal trap also melted the fully frost covered layer within 100 s at-20℃ under sunlamp.The average defrosted length(25 mm)was also observed by irradiation of laser light for 45 s.The self-cleaning slippery photothermal coating showed outstanding deicing performance at subzero temperature for long term due to the infusion of silicone oil into the nanostructures and same chemical composition with binder.
基金This work was supported by the National Natural Science Foundation of China(No.51671105,51705244)Natural Science Foundation of Jiangsu Province(No.BK20170790)+2 种基金the Project Funded by China Postdoctoral Science Foundation(No.2019M661826)Fund of State Key Laboratory of Aerodynamics(SKLA2019020401)Open Fund of Key Laboratory of Icing and Anti/De-icing(No.IADL20190202).
文摘The aim of this study is to explore the heterogeneous ice nucleation behavior based on controllable micro-cubic array structure surfaces from the statistic perspective.To this end,we firstly constructed a group of micro-cubic array structures on silicon substrates by a selective plasma etching technique.After grafting low-free-energy substance,the as-constructed micro-cubic array structure surfaces exhibited higher non-wettability with the water contact angle being up to 150°.On this basis,500 cycles of freezing and melting processes were accurately recorded to analyze the instantaneous ice nucleation behavior according to the statistical results of freezing temperature.As a consequence,the statistical freezing temperature of the sample with micro-spacing distance of 40μm is as low as−17.13°C.This microstructure configuration(conforming to Cassie-Baxter wetting regime)not only could entrap more air pockets,but also achieved lower solid-liquid contact area,resulting in lower ice nucleation rate(~2–3 orders of magnitude less than that on the flat substrate).Furthermore,the gradually increasing micro-spacing distance to 60μm would induce the transition from CassieBaxter to Wenzel wetting state,leading to higher freezing probability and ice nucleation rate.The complete understanding on microstructure configuration improving the ice nucleation will lay the foundation stone for the microstructure design of ice-repellent materials.
基金We acknowledge the financial support from National Natural Science Foundation of China(Nos.22072185,12072381,21872176,and 21805315)Pearl River Talents Program(No.2017GC010671),Natural Science Foundation of Guangdong Province(No.2019A1515012030)Science and Technology Innovation Project of Guangzhou(No.202102020263).
文摘As a ubiquitous natural phenomenon,ice/frost formation on solid surfaces have adverse effects on many commercial and residential activities.Icephobic surfaces feature low ice adhesion strengths(<100 kPa)can passively retard ice formation and ease ice removal.Superhydrophobic surfaces and liquid-lubricating surfaces are two prevailing categories of icephobic surfaces.However,their long-term stability is relatively poor,and the ice adhesion strengths are not low enough for passive removal of small ice crystals(e.g.,frosts)from the surfaces.Herein,we combine the superhydrophobic and liquid-like properties in one surface to obtain durable icephobic surfaces with extremely low ice adhesion strengths(about 0.035 kPa).Ices and frosts can be removed from the surface under the action of gravity or gas purge.These surfaces are prepared based on surface nanoconical structure and covalently-grafted liquid-like perfluorinated polyether(PFPE)coating,which show synergy effects on suppressing icing and frosting by promoting expulsion of subcooled condensate droplets from the nanotexture and decreasing ice adhesion strengths.The icephobic surfaces show significantly better durability compared to lubricant-impregnated textured surfaces.Our results provide a new avenue to design passive anti-icing/anti-frosting surfaces for a wide range of applications where surfaces are exposed to humid and low-temperature environments.
