Ice nucleation and accretion on structural surfaces are sources of major safety and operational concerns in many industries including aviation and renewable energy.Common methods for tackling these are active ones suc...Ice nucleation and accretion on structural surfaces are sources of major safety and operational concerns in many industries including aviation and renewable energy.Common methods for tackling these are active ones such as heating,ultrasound,and chemicals or passive ones such as surface coatings.In this study,we explored the ice adhesion properties of slippery coated substrates by measuring the shear forces required to remove a glaze ice block on the coated substrates.Among the studied nanostructured and nanoscale surfaces[i.e.,a superhydrophobic coating,a fluoropolymer coating,and a polydimethylsiloxane(PDMS)chain coating],the slippery omniphobic covalently attached liquid(SOCAL)surface with its flexible polymer brushes and liquid-like structure significantly reduced the ice adhesion on both glass and silicon surfaces.Further studies of the SOCAL coating on roughened substrates also demonstrated its low ice adhesion.The reduction in ice adhesion is attributed to the flexible nature of the brush-like structures of PDMS chains,allowing ice to detach easily.展开更多
This paper focused on the sessile droplet freezing and ice adhesion on aluminum with different wettability （hydrophilic, com- mon hydrophobic, and superhydrophobic surfaces, coded as HIS, CHS, SHS, respectively） ove...This paper focused on the sessile droplet freezing and ice adhesion on aluminum with different wettability （hydrophilic, com- mon hydrophobic, and superhydrophobic surfaces, coded as HIS, CHS, SHS, respectively） over a surface temperature range of -9℃ to -19℃. It was found that SHS could retard the sessile droplet freezing and lower the ice adhesion probably due to the interfacial air pockets （IAPs） on water/SHS interface. However, as surface temperature decreasing, some IAPs were squeezed out and such freezing retarding and adhesion lowering effect for SHS was reduced greatly. For a surface temperature of-19℃, ice adhesion on SHS was even greater than that on CHS. To discover the reason for the squeezing out of lAPs, forces applied to the suspended water on IAPs were analyzed and it was found that the stability of IAPs was associated with surface mi- cro-structures and surface temperature. These findings might be helpful to designing of SHS with good anti-icing properties.展开更多
Accurate measurement of the interfacial shear strength between ice and solid surface has important reference significance for the design of anti-icing and de-icing functional surfaces.In this paper,a new method is pro...Accurate measurement of the interfacial shear strength between ice and solid surface has important reference significance for the design of anti-icing and de-icing functional surfaces.In this paper,a new method is proposed based on the shear lag model of a single fiber pulled out from matrix,in order to accurately determine the interfacial shear strength(ISS)between ice and metals.The maximum pull-out force at the initiation of interface debonding is well measured in the pull-out test of a metal fiber embedded in an ice matrix.A shear lag model similar to the pull-out test is established and a closed-form relation between the non-uniform interfacial shear stress and the pull-out force is achieved.When the pull-out force reaches its peak value,the ice/metal ISS can be consequently determined as the maximum interfacial shear stress.Such a method takes into account the stress concentration at the interface,which overcomes underestimation of ice/solid ISS based on the apparent strength in previous studies.The achieved ISS is proven to not only have good convergence,but also be independent of the size and embedded depth of metal fibers.Based on the present method,the enhancing effects of freezing temperature and surface roughness on the ice adhesion are further disclosed.The present research provides a simple and reliable approach to accurately calibrate the ice/solid ISS,which should be of important reference significance for the design and assessment of anti-icing functional surfaces.展开更多
Ice adhesion to materials is a significant concern in many fields. Hydrophobic surface has been used for anti-icing in fields of aircraft or transmission line, which prove to be efficacious and economical. However, su...Ice adhesion to materials is a significant concern in many fields. Hydrophobic surface has been used for anti-icing in fields of aircraft or transmission line, which prove to be efficacious and economical. However, such technique is seldom employed for road deicing, because of the texture and service environment of pavement. Instead, deicers such as rock salt are frequently used, which leads to serious corrosion problem of roads and bridges. In this paper, a number of studies that characterize mechanism of ice adhesion to common substrates, specifically to pavement, are reviewed. The most important researches undertaken on ice adhesion strength affecting factors are presented. An overview of studies carried out to find hydrophobie surface for asphalt and cement concrete pavement antiicing are presented. It was verified that the hydrophobicity had high correlation with icephobicity, and nano-engineered asphalt and cement concrete pavement surface exhibited favorable hydrophobicity, and also had good performance on weakening pavement-ice bonding. However, most ice-repelling pavements obtain hydrophobic surface via low surface energy coating, which could not exist on pavement for a long time under wheel abrasion. And the nano/micro structures on hydrophobic surfaces are also vulnerable and consumable. Thus, the long-term effect of hydrophobic surface still need to be improved, and durability of the hydrophobic surface should be the research and development priorities of ice-repelling pavement.展开更多
The effects of modifiers on the anti-wetting and anti-icing property of the prepared rough aluminum surface were investigated.The rough aluminum substrates were obtained through electrochemical oxidization with 15 wt%...The effects of modifiers on the anti-wetting and anti-icing property of the prepared rough aluminum surface were investigated.The rough aluminum substrates were obtained through electrochemical oxidization with 15 wt% sulfuric acid solution as the electrolyte at the constant current of 4 mA for 3 h.And then they were modified with octadecanoic acid (C18),polyethylene (PE),polystyrene (PS),polyethylene glycol (PEG) and hexamethylenetetramine (HMTA),respectively,whose surface free energies were 27.6,31.0,33.0,61.6 and 70.0 mN/m,respectively.The contact angles (CA) were 154.6°,128.4°,127.6°,5.0° and 0.0°,respectively,and the ice adhesion pressures were 15.9,36.3,55.9,155.3 and 216.1 kPa,respectively.The ice adhesion strengths decrease along with the increasing anti-wetting property of aluminum surfaces and the decreasing of the surface energy of modifiers.These provide some new insights when designing the aluminum surface with anti-icing properties in some special applications.展开更多
基金supported by the Engineering and Physical Sciences Research Council(EPSRC)of the U.K.(Grant No.EP/P018998/1)the Acoustofluidics Special Interest Group of the UK Fluids Network(Grant No.EP/N032861/1)the EPSRC Centre for Doctoral Training in Renewable Energy Northeast Universities(ReNU)(Grant No.EP/S023836/1).
文摘Ice nucleation and accretion on structural surfaces are sources of major safety and operational concerns in many industries including aviation and renewable energy.Common methods for tackling these are active ones such as heating,ultrasound,and chemicals or passive ones such as surface coatings.In this study,we explored the ice adhesion properties of slippery coated substrates by measuring the shear forces required to remove a glaze ice block on the coated substrates.Among the studied nanostructured and nanoscale surfaces[i.e.,a superhydrophobic coating,a fluoropolymer coating,and a polydimethylsiloxane(PDMS)chain coating],the slippery omniphobic covalently attached liquid(SOCAL)surface with its flexible polymer brushes and liquid-like structure significantly reduced the ice adhesion on both glass and silicon surfaces.Further studies of the SOCAL coating on roughened substrates also demonstrated its low ice adhesion.The reduction in ice adhesion is attributed to the flexible nature of the brush-like structures of PDMS chains,allowing ice to detach easily.
基金supported by the National Natural Science Foundation of China(Grant Nos.21203089 and 51263018)International Science and Technology Cooperation Program of China(Grant No.2012DFA51200)+1 种基金Science and Technology Project of Jiangxi Province(Grant No.20123BDH80015)the Open Fund of Jiangsu Key Laboratory for Biomass-based Energy and Enzyme Technology(Grant No.JSBEET1224)
文摘This paper focused on the sessile droplet freezing and ice adhesion on aluminum with different wettability （hydrophilic, com- mon hydrophobic, and superhydrophobic surfaces, coded as HIS, CHS, SHS, respectively） over a surface temperature range of -9℃ to -19℃. It was found that SHS could retard the sessile droplet freezing and lower the ice adhesion probably due to the interfacial air pockets （IAPs） on water/SHS interface. However, as surface temperature decreasing, some IAPs were squeezed out and such freezing retarding and adhesion lowering effect for SHS was reduced greatly. For a surface temperature of-19℃, ice adhesion on SHS was even greater than that on CHS. To discover the reason for the squeezing out of lAPs, forces applied to the suspended water on IAPs were analyzed and it was found that the stability of IAPs was associated with surface mi- cro-structures and surface temperature. These findings might be helpful to designing of SHS with good anti-icing properties.
基金supported by the National Natural Science Foundation of China(Grant Nos.12032004,12272043,12293000,and 12293002)。
文摘Accurate measurement of the interfacial shear strength between ice and solid surface has important reference significance for the design of anti-icing and de-icing functional surfaces.In this paper,a new method is proposed based on the shear lag model of a single fiber pulled out from matrix,in order to accurately determine the interfacial shear strength(ISS)between ice and metals.The maximum pull-out force at the initiation of interface debonding is well measured in the pull-out test of a metal fiber embedded in an ice matrix.A shear lag model similar to the pull-out test is established and a closed-form relation between the non-uniform interfacial shear stress and the pull-out force is achieved.When the pull-out force reaches its peak value,the ice/metal ISS can be consequently determined as the maximum interfacial shear stress.Such a method takes into account the stress concentration at the interface,which overcomes underestimation of ice/solid ISS based on the apparent strength in previous studies.The achieved ISS is proven to not only have good convergence,but also be independent of the size and embedded depth of metal fibers.Based on the present method,the enhancing effects of freezing temperature and surface roughness on the ice adhesion are further disclosed.The present research provides a simple and reliable approach to accurately calibrate the ice/solid ISS,which should be of important reference significance for the design and assessment of anti-icing functional surfaces.
基金the financial support from the Special Fund for Basic Scientific Research of Central Colleges, Changan University (310831151080, 310831153409, 310831153315 and 310831151085)Natural Science Basic Research Plan in Shaanxi Province of China (2017JQ2025)+1 种基金Xi'an Science and Technology Planning Project (2017137SF/WM031)Transportation Construction & Technology Project of Shanxi Department of Transportation (No. 16-2-12)
文摘Ice adhesion to materials is a significant concern in many fields. Hydrophobic surface has been used for anti-icing in fields of aircraft or transmission line, which prove to be efficacious and economical. However, such technique is seldom employed for road deicing, because of the texture and service environment of pavement. Instead, deicers such as rock salt are frequently used, which leads to serious corrosion problem of roads and bridges. In this paper, a number of studies that characterize mechanism of ice adhesion to common substrates, specifically to pavement, are reviewed. The most important researches undertaken on ice adhesion strength affecting factors are presented. An overview of studies carried out to find hydrophobie surface for asphalt and cement concrete pavement antiicing are presented. It was verified that the hydrophobicity had high correlation with icephobicity, and nano-engineered asphalt and cement concrete pavement surface exhibited favorable hydrophobicity, and also had good performance on weakening pavement-ice bonding. However, most ice-repelling pavements obtain hydrophobic surface via low surface energy coating, which could not exist on pavement for a long time under wheel abrasion. And the nano/micro structures on hydrophobic surfaces are also vulnerable and consumable. Thus, the long-term effect of hydrophobic surface still need to be improved, and durability of the hydrophobic surface should be the research and development priorities of ice-repelling pavement.
基金Funded by National Natural Science Foundation of China(No.51801058)the Special Program for Guiding Local Science and Technology Development by the Central Government of Hubei Province(No.2019ZYYD006)Hubei Provincial Natural Science Foundation of China(No.2018CFB759)。
文摘The effects of modifiers on the anti-wetting and anti-icing property of the prepared rough aluminum surface were investigated.The rough aluminum substrates were obtained through electrochemical oxidization with 15 wt% sulfuric acid solution as the electrolyte at the constant current of 4 mA for 3 h.And then they were modified with octadecanoic acid (C18),polyethylene (PE),polystyrene (PS),polyethylene glycol (PEG) and hexamethylenetetramine (HMTA),respectively,whose surface free energies were 27.6,31.0,33.0,61.6 and 70.0 mN/m,respectively.The contact angles (CA) were 154.6°,128.4°,127.6°,5.0° and 0.0°,respectively,and the ice adhesion pressures were 15.9,36.3,55.9,155.3 and 216.1 kPa,respectively.The ice adhesion strengths decrease along with the increasing anti-wetting property of aluminum surfaces and the decreasing of the surface energy of modifiers.These provide some new insights when designing the aluminum surface with anti-icing properties in some special applications.
基金support of the NANO2021 Project Dual-Functional Anti-Gas Hydrate Surfaces (DAndra,302348)the FRIPRO Project towards the Design of Super-Low Ice Adhesion Surfaces (SLICE,250990)the Norwegian Micro-and Nano-Fabrication Facility,Nor Fab (295864)。
