Superhydrophobic surface(SHS) has been well developed, as SHS renders the property of minimizing the water/solid contact interface. Water droplets deposited onto SHS with contact angles exceeding 150°, allow them...Superhydrophobic surface(SHS) has been well developed, as SHS renders the property of minimizing the water/solid contact interface. Water droplets deposited onto SHS with contact angles exceeding 150°, allow them to retain spherical shapes, and the low adhesion of SHS facilitates easy droplet collection when tilting the substrate. These characteristics make SHS suitable for a wide range of applications. One particularly promising application is the fabrication of microsphere and supraparticle materials. SHS offers a distinct advantage as a universal platform capable of providing customized services for a variety of microspheres and supraparticles. In this review, an overview of the strategies for fabricating microspheres and supraparticles with the aid of SHS, including cross-linking process, polymer melting,and droplet template evaporation methods, is first presented. Then, the applications of microspheres and supraparticles formed onto SHS are discussed in detail, for example, fabricating photonic devices with controllable structures and tunable structural colors, acting as catalysts with emerging or synergetic properties, being integrated into the biomedical field to construct the devices with different medicinal purposes, being utilized for inducing protein crystallization and detecting trace amounts of analytes. Finally,the perspective on future developments involved with this research field is given, along with some obstacles and opportunities.展开更多
A silylated melamine sponge(SMS)was prepared by two simple steps,namely,immersion and dehydration of a melamine sponge coated with methyltrichlorosilane.The silylated structure of SMS was characterized by FT-IR(Fourie...A silylated melamine sponge(SMS)was prepared by two simple steps,namely,immersion and dehydration of a melamine sponge coated with methyltrichlorosilane.The silylated structure of SMS was characterized by FT-IR(Fourier-transform infrared)spectroscopy,SEM(Scanning electron microscopy)and in terms of water contact angles.Its oil-water absorption and separation capacities were measured by FT-IR and UV-visible spectrophoto-metry.The experimental results have shown that oligomeric silanol covalently bonds by Si-N onto the surface of melamine sponge skeletons.SMS has shown superhydrophobicity with a water contact angle exceeding 150°±1°,a better separation efficiency with regard to diesel oil(by 99.31%(wt/wt%)in oil-water mixture and even up to 99.99%(wt/wt%)for diesel oil in its saturated aqueous solution.Moreover,SMS inherited the intrinsicflame retardancy of the melamine sponge.In general,SMS has shown superhydrophobicity,high porosity,excellent selectivity,remarkable recyclability,and better absorption capacity for various oils and organic solvents,and a high separation efficiency for oil in saturated aqueous solutions.展开更多
Magnesium(Mg)alloys,the lightest metal construction material used in industry,play a vital role in future development.However,the poor corrosion resistance of Mg alloys in corrosion environments largely limits their p...Magnesium(Mg)alloys,the lightest metal construction material used in industry,play a vital role in future development.However,the poor corrosion resistance of Mg alloys in corrosion environments largely limits their potential wide applications.Therefore,a micro-arc oxidation/graphene oxide/stearic acid(MAO/GO/SA)superhydrophobic composite coating with superior corrosion resistance was fabricated on a Mg alloy AZ91D through micro-arc oxidation(MAO)technology,electrodeposition technique,and self-assembly technology.The composition and microstructure of the coating were characterized by scanning electron microscopy,X-ray diffraction,energy dispersive spectroscopy,and Raman spectroscopy.The effective protection of the MAO/GO/SA composite coating applied to a substrate was evaluated using potentiodynamic polarization,electrochemical impedance spectroscopy tests,and salt spray tests.The results showed that the MAO/GO/SA composite coating with a petal spherical structure had the best superhydrophobicity,and it attained a contact angle of 159.53°±2°.The MAO/GO/SA composite coating exhibited high resistance to corrosion,according to electrochemical and salt spray tests.展开更多
Mg alloys are considered the most promising engineering materials because of their unique properties.However,the uncontrolled corrosion rate of these alloys limits their applications.Therefore,in this study,a micro-ar...Mg alloys are considered the most promising engineering materials because of their unique properties.However,the uncontrolled corrosion rate of these alloys limits their applications.Therefore,in this study,a micro-arc oxidation layer was used as a transition layer to“directly”grow a zinc-based metal-organic framework(MOF)composite coating on the surface of a Mg alloy(AZ91D).Herein,the two zeolitic imidazolate framework(ZIF-8)coatings with different morphologies were separately prepared by homologous metal oxide induction and a one-step in-situ growth method.The superhydrophobic composite coating showed strong hydrophobicity and self-cleaning properties,which could prevent the penetration of water and corrosive ions(Cl^(−))into the surface of AZ91D.Electrochemical tests demonstrated that the super-hydrophobic composite coatings greatly enhanced the corrosion resistance of AZ91D,and the corrosion current density decreased from 10^(−5)to 10^(−9)A/cm^(2).These results indicate that the ZIF-8 coatings are beneficial for improving the hydrophobicity and enhancing the corrosion resistance of Mg alloys.Therefore,MOF composite coatings provide a new strategy that can be used to prepare multifunctional anticorrosion coatings on metal substrates.展开更多
It has been proved that the construction of interconnected armour on superhydrophobic surface could significantly enhance the mechanical robustness.Here,a new kind of armour with frame/protrusion hybrid structure was ...It has been proved that the construction of interconnected armour on superhydrophobic surface could significantly enhance the mechanical robustness.Here,a new kind of armour with frame/protrusion hybrid structure was achieved by nanosecond laser technology.Then,this armoured superhydrophobic surface demonstrated excellent durability,which could withstand linear abrasion(~3 N press)800 cycles,water jet test(1.0 MPa pressure)40 times and 100℃treatment 18 days.Particularly,the armoured superhydrophobic sample shows outstanding anti-icing ability,which can speed up the supercooled water dropping(no adhesion within 2 h),increase the freezing delay time by~3 times and maintain low adhesion force(less than 35 kPa)after 30 icing/de-icing cycles.Further finite element analysis and theoretical modeling proved that the developed frame/protuberance hybrid structure could effectively enhance the durability.The relatively low surface accuracy in this study can significantly reduce processing cost,which provides a bright future for the practical application of armour superhydrophobic materials.展开更多
In the past few decades,inspired by the superhydrophobic surfaces(SHPS)of animals and plants such as lotus leaves,rose petals,legs of water striders,and wings of butterflies,preparing metal materials with metallic SHP...In the past few decades,inspired by the superhydrophobic surfaces(SHPS)of animals and plants such as lotus leaves,rose petals,legs of water striders,and wings of butterflies,preparing metal materials with metallic SHPS(MSHPS)have attracted great research interest,due to the great prospect in practical applications.To obtain SHPS on conventional metal materials,it is necessary to construct rough surface,followed by modification with low surface energy substances.In this paper,the action mechanism and the current research status of MSHPS were reviewed through the following aspects.Firstly,the model of wetting theory was presented,and then the progress in MSHPS preparation through chemical etching method was discussed.Secondly,the applications of MSHPS in self-cleaning,anti-icing,corrosion resistance,drag reduction,oil-water separation,and other aspects were introduced.Finally,the challenges encountered in the present application of MSHPS were summarized,and the future research interests were discussed.展开更多
Ice and frost buildup continuously pose significant challenges to multiple fields.As a promising de-icing/defrosting alternative,designing photothermal coatings that leverage on the abundant sunlight source on the ear...Ice and frost buildup continuously pose significant challenges to multiple fields.As a promising de-icing/defrosting alternative,designing photothermal coatings that leverage on the abundant sunlight source on the earth to facilitate ice/frost melting has attracted tremendous attention recently.However,previous designs suffered from either localized surface heating owing to the limited thermal conductivity or unsatisfied meltwater removal rate due to strong water/substrate interaction.Herein,we developed a facile approach to fabricate surfaces that combine photothermal,heat-conducting,and superhydrophobic properties into one to achieve efficient de-icing and defrosting.Featuring copper nanowire assemblies,such surfaces were fabricated via the simple template-assisted electrodeposition method,allowing us to tune the nanowire assembly geometry by adjusting the template dimensions and electrodeposition time.The highly ordered copper nanowire assemblies facilitated efficient sunlight absorption and lateral heat spreading,resulting in a fast overall temperature rise to enable the thawing of ice and frost.Further promoted by the excellent water repellency of the surface,the thawed ice and frost could be spontaneously and promptly removed.In this way,the all-in-one design enabled highly enhanced de-icing and defrosting performance compared to other nanostructured surfaces merely with superhydrophobicity,photothermal effect,or the combination of both.In particular,the defrosting efficiency could approach∼100%,which was the highest compared to previous studies.Overall,our approach demonstrates a promising path toward designing highly effective artificial deicing/defrosting surfaces.展开更多
Nowadays, oil contamination has become a major reason for water pollution, and presents a global environmental challenge. Although many efforts have been devoted to the fabrication of oil/water separation materials, t...Nowadays, oil contamination has become a major reason for water pollution, and presents a global environmental challenge. Although many efforts have been devoted to the fabrication of oil/water separation materials, their practical applications are still hindered by their weak durability, poor chemical tolerance,environmental resistance, and potential negative impact on health and the environment. To overcome these drawbacks, this work offers a facile method to fabricate the eco-friendly and durable oil/water separation membrane fabrics by alkaline hydrolysis and silicon polyurethane coating. The X-ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy results demonstrate that silicon polyurethane membrane could be coated onto the surface of hydrolyzed polyester fabric and form a micro-/nano-scaled hierarchical structure. Based on this, the modified fabric could have a stable superhydrophobic property with a water contact angle higher than 150°, even after repeated washing and mechanical abrasion 800 times, as well as chemical corrosion. Moreover, the modified fabrics show excellent oil/water separation efficiency of up to 99% for various types of oil–water mixture. Therefore, this durable, eco-friendly and cost-efficient superhydrophobic fabric has great potential in large-scale oil/water separation.展开更多
Superhydrophobic materials are severely limited in their applications due to their weak mechanical properties and complex preparation process.In this paper,polystyrene/fluorinated silica(PS/SiO_(2))superhydrophobic co...Superhydrophobic materials are severely limited in their applications due to their weak mechanical properties and complex preparation process.In this paper,polystyrene/fluorinated silica(PS/SiO_(2))superhydrophobic composite coatings were prepared on the surface of 304 stainless steel using a simple one-step spraying method.The effects of different PS contents on the wettability as well as the wear properties of the samples were investigated.SiO_(2) was encapsulated in polystyrene to form a structure similar to cement encapsulated stones.With the addition of PS,a mound-like structure was formed on the sample surface,and a more optimized micro–nano structure was obtained when the content of PS was 0.6 g.At this time,the sample exhibited excellent wettability with a contact angle of 157.86°and a sliding angle of 0.84°.In addition,the contact angle of 151.09°was achieved after 180 cm of friction under a 100 g load and the composite coating prepared by this method also has excellent chemical stability,water impact resistance,corrosion resistance,and self-cleaning properties.This opens up new possibilities for the development of simple and robust superhydrophobic materials.展开更多
A longstanding quest in material science has been the development of superhydrophobic coating based on a single material, without the requirement of fluorination or silane treatment. In this work, the micro-arc oxidat...A longstanding quest in material science has been the development of superhydrophobic coating based on a single material, without the requirement of fluorination or silane treatment. In this work, the micro-arc oxidation(MAO) coating as transition layer can effectively enhance the bonding force of the superhydrophobic coating. The semiconductor@metal organic frameworks(MOFs) core-shell structure was synthesized by a simple self-templating method, and obtained ZnO@2-methylimidazole zinc salt(ZIF-8) nanorods array on magnesium(Mg)alloy. ZnO nanorods not only act as the template but also provide Zn^(2+) for ZIF-8. In addition, we proved that the ligand concentration,synthesis time and temperature are the keys to the preparation of ZnO@ZIF-8 nanorods. As we expect, the ZnO@ZIF-8 nanorods array can trap air in the gaps to form an air layer, and the coating exhibits superhydrophobic properties(154.81°). Excitingly, ZnO@ZIF-8 nanorods array shown a superhydrophobic property, without the requirement of fluorination or silane treatment. The results shown that the coating has good chemical stability and self-cleaning performance. Meanwhile, the corrosion resistance has been significantly improved, R_(ct) was increased from 1.044×10^(3) to 1.414×10^(6) Ω/cm^(2) and I_(corr) was reduced from 4.275×10^(-5) to 5.611×10^(-9)A/cm^2. Therefore, the semiconductor@MOFs core-shell structure has broad application prospects in anti-corrosion.展开更多
In this paper, the superhydrophobic polyurethane sponge(SS-PU) was facilely fabricated by etching with Jones reagent to bind the nanoparticles of Ni-Co double layered oxides(LDOs) on the surface, and following modific...In this paper, the superhydrophobic polyurethane sponge(SS-PU) was facilely fabricated by etching with Jones reagent to bind the nanoparticles of Ni-Co double layered oxides(LDOs) on the surface, and following modification with n-dodecyl mercaptan(DDT). This method provides a new strategy to fabricate superhydrophobic PU sponge with a water contact angle of 157° for absorbing oil with low cost and in large scale. It exhibits the strong absorption capacity and highly selective characteristic for various kinds of oils which can be recycled by simple squeezing. Besides, the as-prepared sponge can deal with the floating and underwater oils, indicating its application value in handling oil spills and domestic oily wastewater. The good self-cleaning ability shows the potential to clear the pollutants due to the ultralow adhesion to water. Especially, the most important point is that the superhydrophobic sponge can continuously and effectively separate the oil/water mixture against the condition of turbulent disturbance by using our designed device system, which exhibit its good superhydrophobicity, strong stability.Furthermore, the SS-PU still maintained stable absorption performance after 150 cycle tests without losing capacity obviously, showing excellent durability in long-term operation and significant potential as an efficient absorbent in large-scale dispose of oily water.展开更多
Bionic superhydrophobic coating has extremely broad application prospects and practical value. It is based on two important conditions, one is the construction of micro–nano structure, the other is the material with ...Bionic superhydrophobic coating has extremely broad application prospects and practical value. It is based on two important conditions, one is the construction of micro–nano structure, the other is the material with low surface energy. How to stabilize the micro–nano structure has become the focus of researches. In this work, a layer of Zn film is deposited on the stainless steel mesh with sturdy micron structure by RF magnetron sputtering. The solid micron structure of the stainless steel mesh itself, combined with the method of thermal oxidation, the surface of the stainless steel mesh is thus formed into a nanorod like ZnO nano structure, and then modified with perfluorodecyltriethoxysilane (PFDS) for low surface energy. The maximum contact angle of the superhydrophobic sample is 154.8°, and the minimum sliding angle is 2°, and it also has excellent corrosion resistance, thermal stability, self-cleaning, anti-aging and anti-icing properties, which provides a design idea for the preparation of superhydrophobic coatings.展开更多
A novel combined method for the formation of composite coatings on the Mg-Mn-Ce alloy is developed.Ceramic like matrix was formed on the Mg alloy surface by the plasma electrolytic oxidation.Then the samples were subs...A novel combined method for the formation of composite coatings on the Mg-Mn-Ce alloy is developed.Ceramic like matrix was formed on the Mg alloy surface by the plasma electrolytic oxidation.Then the samples were subsequently processed by dip-coating in an alcohol suspension of superdispersed polytetrafluoroethylene and spraying with the tetrafluoroethylene telomers solution.SEM,OSP,and SPM was used to study structure of formed surfaces.It was established by measurements of CA and CAH,as well as surface free energy calculations that formed coatings demonstrate superhydrophobic properties due to the presence of an irregular hierarchical surface structure and low surface free energy of fluoropolymers.The coating preserves its hydrophobic properties after exposure to high and low temperatures,for a long time as well as being in corrosive environments.EDS and XRD data analysis confirmed the presence of organofluorine compounds in the composite layers,including in the form of crystalline polytetrafluoroethylene.Using potentiodynamic polarization test and EIS,it was found that the resulting coatings significantly increase the corrosion resistance of Mg material.These data are also confirmed by salt spray tests for 40 days.Incorporation of fluoropolymers additionally decrease coatings coefficient of friction.展开更多
Learning hydrophobic phenomena from nature is always a promising approach to design the superhydrophobic surface.Purple orchid leaf which processes superhydrophobicity is an ideal plant model,and through mimicking its...Learning hydrophobic phenomena from nature is always a promising approach to design the superhydrophobic surface.Purple orchid leaf which processes superhydrophobicity is an ideal plant model,and through mimicking its structure,the surface with excellent hydrophobicity is able to be obtained.However,the unclear of the diversity in wettability during the different vegetation stages and the absence of its relation to the surface morphology limits the further enhancement of the inspired structure.Here,we analyze the wettability difference as the leaf grows from tender to mature and then to senescent.Combining with the variation of surface morphology and chemical composition,the well-developed micro-scale basic unit bumps with dense nano-scale waxy layer on the surface are proven to be responsible for the best hydrophobicity of the mature leaf.The presence of the undeveloped or damaged micro-nano hierarchical structure reduces the formation of air pockets at the interface,leading to the decrease of the wettability for leaves at other stages.Moreover,by fabricating artificial leaves,the nano-waxy layer is proved to be more effective than that of the micro-bumps on the surface wettability.The results of study are of a great significance for guiding the design and fabrication of plant-inspired bionic superhydrophobic surface.展开更多
In atmospheric conditions, CuⅠis easily oxidized to CuⅡdue to the coexistence of moisture and oxygen.The poor oxidation inhibition of CuⅠrestricts the practical application of CuⅠ-containing materials.Herein we in...In atmospheric conditions, CuⅠis easily oxidized to CuⅡdue to the coexistence of moisture and oxygen.The poor oxidation inhibition of CuⅠrestricts the practical application of CuⅠ-containing materials.Herein we introduce an approach to construct a superhydrophobic microenvironment in CuⅠfunctionalized metal–organic frameworks by coordinatedly grafting organic amine compounds onto open metal sites(OMSs), which can hinder the accessibility of moisture to pores thereby enhancing the stability of CuⅠ. As a proof of concept, MIL-101(Cr) with abundant OMSs and octadecylamine(OA)with long hydrophobic alkyl groups are used as carrier and surface coating. As superhydrophobic porous materials, the resultant CuⅠM-OA exhibits improved CuⅠstability in addition to retaining high crystallinity and intact porosity while almost all CuⅠis oxidized in hydrophilic CuⅠM upon exposure in a humid atmosphere for 30 h. CuⅠM-OA owns excellent adsorption desulfurization performance(ADS) with regard to thiophene, benzothiophene, and 4,6-dimethyl dibenzothiophene. Even from hydrated fuel, the adsorption performance of CuⅠM-OA maintains well while the adsorption capacity of CuⅠM decreases to 7% after4 cycles. The remarkable moisture resistance, CuⅠstability, and high porosity make the current adsorbent CuⅠM-OA highly promising for the practical ADS process.展开更多
Superhydrophobic(SH)coatings are intended to resist a surface from corrosion and thereby increases the product life duration.It is also a promising solution to save cleaning costs and time by providing self-clea...Superhydrophobic(SH)coatings are intended to resist a surface from corrosion and thereby increases the product life duration.It is also a promising solution to save cleaning costs and time by providing self-clean nature to the surface.This review article provides the most recent updates in designing SH surfaces and their characterizations adopted both in experimental and computational techniques.To gain a comprehensive perspective,the SH surfaces present in nature those are inspiring human beings to mimic such surfaces are introduced at the beginning of this article.Subsequently,different fabrication techniques undertaken recently to design artificial SH surfaces are briefly discussed.Recent progress in computations employed in the development of SH surfaces is then discussed.Next,the limitations in SH surfaces are addressed.Finally,perceptiveness of different strategies and their limitations are presented in the concluding remarks and outlook.Overall,this mini review article brings together and highlights the significant advancements in fabrication of superhydrophobic surfaces which may surely help the early-stage researchers/scientists to plan their work accordingly.展开更多
In the present review,the formation of superhydrophobic(SHP)structures on the surface of Mg alloys was investigated.Different methods including hydrothermal technique,chemical and electrochemical deposition,conversion...In the present review,the formation of superhydrophobic(SHP)structures on the surface of Mg alloys was investigated.Different methods including hydrothermal technique,chemical and electrochemical deposition,conversion and polymer coating,and etching routes were discussed.The superhydrophobicity could form on the surface of Mg alloys by the application of different chemical,electrochemical,and physical methods followed by the immersion of these alloys in the solution containing modifying agents including fatty acids or long-chain molecules.The formed morphology,composition,and contact angle were reported and the effect of synthesis route on these characteristics was reviewed.展开更多
It is well known that surface roughness has a very important effect on superhydrophobicity.The Wenzel and Cassie-Baxtermodels,which correspond to the homogeneous and heterogeneous wetting respectively,are currently pr...It is well known that surface roughness has a very important effect on superhydrophobicity.The Wenzel and Cassie-Baxtermodels,which correspond to the homogeneous and heterogeneous wetting respectively,are currently primary instructions fordesigning superhydrophobic surfaces.However,the particular drop shape that a drop exhibits might depend on how it is formed.A water drop can occupy multiple equilibrium states,which relate to different local minimal energy.In some cases,both equilibriumstates can even co-exist on a same substrate.Thus the apparent contact angles may vary and have different values.Wediscuss how the Wenzel and Cassie-Baxter equations determine the homogeneous and heterogeneous wetting theoretically.Contact angle analysis on hierarchical surface structure and contact angle hysteresis has been put specific attention.In particular,we study the energy barrier of transition from Cassie-Baxter state to Wenzel state,based on existing achievement by previousresearchers,to determine the possibility of the transition and how it can be interpreted.It has been demonstrated that surfaceroughness and geometry will influence the energy required for a drop to get into equilibrium,no matter it is homogeneous orheterogeneous wetting.展开更多
A one-step electrodeposition method was used to construct a superhydrophobic coating on the surface of magnesium alloy.Using magne-sium nitrate and ethanol solution of stearic acid as electrolyte,four groups of electr...A one-step electrodeposition method was used to construct a superhydrophobic coating on the surface of magnesium alloy.Using magne-sium nitrate and ethanol solution of stearic acid as electrolyte,four groups of electrolytes with different ratios of stearic acid and magnesium nitrate were designed to explore the influence of electrolyte to the process.The contact angles of the four coating samples were 136.4±5.8°,152.7±2.8°,156.2±4.9°and 155.1±4.4°The addition of magnesium nitrate in the solution increased the hydrogen evolution reaction in the electrodeposition process,which was not conducive to electrodeposition process.During the deposition process,the sample prepared in a molar ratio of stearic acid to magnesium nitrate of 10:1 had the best corrosion resistance,and its corrosion circuit density was 3.74×10^(−8)A/cm^(2),far lower than the corrosion current density of the magnesium alloy substrate.展开更多
Although superhydrophobic materials have attracted much research interest in anti-icing,some controversy still exists.In this research,we report a cost-effective method used to verify the contribution of area fraction...Although superhydrophobic materials have attracted much research interest in anti-icing,some controversy still exists.In this research,we report a cost-effective method used to verify the contribution of area fraction to ice adhesion strength.We tried to partially-embed siliea nanopnarticles into microscale fabrics of a commercial polyamide mesh.Then,the area fraction could be determined by altering the mesh size.Generally,the ice adhesion strength decreases as the area fraction decreases.An ice adhesion strength of~1.9 kPa and a delayed freezing time of~1048 s can be obtained.We attribute the low ice adhesion strength to the combination of superhydro-phobicity and stress concentration.The superhydrophobicity prohibits the water from penetrating into the voids of the meshes,and the small actual contact area leads to stress concentration which promotes interfacial crack propagation.Moreover,our superhydrophobic mesh simultaneously exhibis a micro-nano hierarchical structure and a partally-cmbedded structure.Therefore,the as-prepared superhydrophobic mesh retained the ieephobicity after 20 icingldeicing cycles,and maintained its superhydrophobicity even afier 60 sandpaper-abrasion cycles and a 220"C thermal treatment.展开更多
基金the financial support from Shenzhen Science and Technology Program (JCYJ20210324142210027, X.D.)the National Natural Science Foundation of China (52103136, 22275028, U22A20153, 22102017, 22302033, and 52106194)+5 种基金the Sichuan Outstanding Young Scholars Foundation (2021JDJQ0013)Natural Science Foundation of Sichuan Province (2022NSFSC1271)Sichuan Science and Technology Program (2023JDRC0082)“Oncology Medical Engineering Innovation Foundation” project of University of Electronic Science and Technology of China and Sichuan Cancer Hospital (ZYGX2021YGCX009)“Medical and Industrial Cross Foundation” of University of Electronic Science and Technology of China and Sichuan Provincial People’s Hospital (ZYGX2021YGLH207)Shandong Key R&D grant (2022CXGC010509)。
文摘Superhydrophobic surface(SHS) has been well developed, as SHS renders the property of minimizing the water/solid contact interface. Water droplets deposited onto SHS with contact angles exceeding 150°, allow them to retain spherical shapes, and the low adhesion of SHS facilitates easy droplet collection when tilting the substrate. These characteristics make SHS suitable for a wide range of applications. One particularly promising application is the fabrication of microsphere and supraparticle materials. SHS offers a distinct advantage as a universal platform capable of providing customized services for a variety of microspheres and supraparticles. In this review, an overview of the strategies for fabricating microspheres and supraparticles with the aid of SHS, including cross-linking process, polymer melting,and droplet template evaporation methods, is first presented. Then, the applications of microspheres and supraparticles formed onto SHS are discussed in detail, for example, fabricating photonic devices with controllable structures and tunable structural colors, acting as catalysts with emerging or synergetic properties, being integrated into the biomedical field to construct the devices with different medicinal purposes, being utilized for inducing protein crystallization and detecting trace amounts of analytes. Finally,the perspective on future developments involved with this research field is given, along with some obstacles and opportunities.
基金funded by Qingyang Science and Technology Support Project(KT2019-03)。
文摘A silylated melamine sponge(SMS)was prepared by two simple steps,namely,immersion and dehydration of a melamine sponge coated with methyltrichlorosilane.The silylated structure of SMS was characterized by FT-IR(Fourier-transform infrared)spectroscopy,SEM(Scanning electron microscopy)and in terms of water contact angles.Its oil-water absorption and separation capacities were measured by FT-IR and UV-visible spectrophoto-metry.The experimental results have shown that oligomeric silanol covalently bonds by Si-N onto the surface of melamine sponge skeletons.SMS has shown superhydrophobicity with a water contact angle exceeding 150°±1°,a better separation efficiency with regard to diesel oil(by 99.31%(wt/wt%)in oil-water mixture and even up to 99.99%(wt/wt%)for diesel oil in its saturated aqueous solution.Moreover,SMS inherited the intrinsicflame retardancy of the melamine sponge.In general,SMS has shown superhydrophobicity,high porosity,excellent selectivity,remarkable recyclability,and better absorption capacity for various oils and organic solvents,and a high separation efficiency for oil in saturated aqueous solutions.
基金financially supported by the Guangxi Natural Science Foundation,China(No.2020GXNSFAA 159011)the National Natural Science Foundation of China(No.51664011).
文摘Magnesium(Mg)alloys,the lightest metal construction material used in industry,play a vital role in future development.However,the poor corrosion resistance of Mg alloys in corrosion environments largely limits their potential wide applications.Therefore,a micro-arc oxidation/graphene oxide/stearic acid(MAO/GO/SA)superhydrophobic composite coating with superior corrosion resistance was fabricated on a Mg alloy AZ91D through micro-arc oxidation(MAO)technology,electrodeposition technique,and self-assembly technology.The composition and microstructure of the coating were characterized by scanning electron microscopy,X-ray diffraction,energy dispersive spectroscopy,and Raman spectroscopy.The effective protection of the MAO/GO/SA composite coating applied to a substrate was evaluated using potentiodynamic polarization,electrochemical impedance spectroscopy tests,and salt spray tests.The results showed that the MAO/GO/SA composite coating with a petal spherical structure had the best superhydrophobicity,and it attained a contact angle of 159.53°±2°.The MAO/GO/SA composite coating exhibited high resistance to corrosion,according to electrochemical and salt spray tests.
基金supported by Guangxi Natural Science Foundation of China(No.2020GXNSFAA159011)National Natural Science Foundation of China(No.51664011)Guangxi Key Laboratory Foundation of China(No.EMFM20211120).
文摘Mg alloys are considered the most promising engineering materials because of their unique properties.However,the uncontrolled corrosion rate of these alloys limits their applications.Therefore,in this study,a micro-arc oxidation layer was used as a transition layer to“directly”grow a zinc-based metal-organic framework(MOF)composite coating on the surface of a Mg alloy(AZ91D).Herein,the two zeolitic imidazolate framework(ZIF-8)coatings with different morphologies were separately prepared by homologous metal oxide induction and a one-step in-situ growth method.The superhydrophobic composite coating showed strong hydrophobicity and self-cleaning properties,which could prevent the penetration of water and corrosive ions(Cl^(−))into the surface of AZ91D.Electrochemical tests demonstrated that the super-hydrophobic composite coatings greatly enhanced the corrosion resistance of AZ91D,and the corrosion current density decreased from 10^(−5)to 10^(−9)A/cm^(2).These results indicate that the ZIF-8 coatings are beneficial for improving the hydrophobicity and enhancing the corrosion resistance of Mg alloys.Therefore,MOF composite coatings provide a new strategy that can be used to prepare multifunctional anticorrosion coatings on metal substrates.
基金supported by Beijing Nature Science Foundation(3232054)National Nature Science Foundation of China(51977079)+4 种基金Key Laboratory of Icing and Anti/De-icing of CARDC(Grant No.IADL 20210401)the Central Guidance on Local Science and Technology Development Fund of Hebei Province(226Z1204G)the Top Young Innovative Talents of Colleges and Universities of Higher Learning Institutions of Hebei(BJ2021095)Youth Elite Scientists Sponsorship Program by Chinese Society for Electrical Engineering(CSEE-YESS-2017002)the Fundamental Research Funds for the Central Universities(2020MS115).
文摘It has been proved that the construction of interconnected armour on superhydrophobic surface could significantly enhance the mechanical robustness.Here,a new kind of armour with frame/protrusion hybrid structure was achieved by nanosecond laser technology.Then,this armoured superhydrophobic surface demonstrated excellent durability,which could withstand linear abrasion(~3 N press)800 cycles,water jet test(1.0 MPa pressure)40 times and 100℃treatment 18 days.Particularly,the armoured superhydrophobic sample shows outstanding anti-icing ability,which can speed up the supercooled water dropping(no adhesion within 2 h),increase the freezing delay time by~3 times and maintain low adhesion force(less than 35 kPa)after 30 icing/de-icing cycles.Further finite element analysis and theoretical modeling proved that the developed frame/protuberance hybrid structure could effectively enhance the durability.The relatively low surface accuracy in this study can significantly reduce processing cost,which provides a bright future for the practical application of armour superhydrophobic materials.
基金the financial support of Shanghai Pujiang Program(22PJD001)the Scientific Research Project from Science and Technology Commission of Shanghai Municipality(19DZ1204903)the Fundamental Research Funds for the Central Universities(2232021G-11)。
文摘In the past few decades,inspired by the superhydrophobic surfaces(SHPS)of animals and plants such as lotus leaves,rose petals,legs of water striders,and wings of butterflies,preparing metal materials with metallic SHPS(MSHPS)have attracted great research interest,due to the great prospect in practical applications.To obtain SHPS on conventional metal materials,it is necessary to construct rough surface,followed by modification with low surface energy substances.In this paper,the action mechanism and the current research status of MSHPS were reviewed through the following aspects.Firstly,the model of wetting theory was presented,and then the progress in MSHPS preparation through chemical etching method was discussed.Secondly,the applications of MSHPS in self-cleaning,anti-icing,corrosion resistance,drag reduction,oil-water separation,and other aspects were introduced.Finally,the challenges encountered in the present application of MSHPS were summarized,and the future research interests were discussed.
基金financial support from the National Natural Science Foundation of China (51836002 and 52006025)Fundamental Research Funds for the Central Universities (DUT22LAB601 and DUT22LAB610)
文摘Ice and frost buildup continuously pose significant challenges to multiple fields.As a promising de-icing/defrosting alternative,designing photothermal coatings that leverage on the abundant sunlight source on the earth to facilitate ice/frost melting has attracted tremendous attention recently.However,previous designs suffered from either localized surface heating owing to the limited thermal conductivity or unsatisfied meltwater removal rate due to strong water/substrate interaction.Herein,we developed a facile approach to fabricate surfaces that combine photothermal,heat-conducting,and superhydrophobic properties into one to achieve efficient de-icing and defrosting.Featuring copper nanowire assemblies,such surfaces were fabricated via the simple template-assisted electrodeposition method,allowing us to tune the nanowire assembly geometry by adjusting the template dimensions and electrodeposition time.The highly ordered copper nanowire assemblies facilitated efficient sunlight absorption and lateral heat spreading,resulting in a fast overall temperature rise to enable the thawing of ice and frost.Further promoted by the excellent water repellency of the surface,the thawed ice and frost could be spontaneously and promptly removed.In this way,the all-in-one design enabled highly enhanced de-icing and defrosting performance compared to other nanostructured surfaces merely with superhydrophobicity,photothermal effect,or the combination of both.In particular,the defrosting efficiency could approach∼100%,which was the highest compared to previous studies.Overall,our approach demonstrates a promising path toward designing highly effective artificial deicing/defrosting surfaces.
基金the financial support provided by the National Natural Science Foundation of China (21808044)。
文摘Nowadays, oil contamination has become a major reason for water pollution, and presents a global environmental challenge. Although many efforts have been devoted to the fabrication of oil/water separation materials, their practical applications are still hindered by their weak durability, poor chemical tolerance,environmental resistance, and potential negative impact on health and the environment. To overcome these drawbacks, this work offers a facile method to fabricate the eco-friendly and durable oil/water separation membrane fabrics by alkaline hydrolysis and silicon polyurethane coating. The X-ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy results demonstrate that silicon polyurethane membrane could be coated onto the surface of hydrolyzed polyester fabric and form a micro-/nano-scaled hierarchical structure. Based on this, the modified fabric could have a stable superhydrophobic property with a water contact angle higher than 150°, even after repeated washing and mechanical abrasion 800 times, as well as chemical corrosion. Moreover, the modified fabrics show excellent oil/water separation efficiency of up to 99% for various types of oil–water mixture. Therefore, this durable, eco-friendly and cost-efficient superhydrophobic fabric has great potential in large-scale oil/water separation.
基金This study was supported by the National Natural Science Foundation of China(Grant Number 52172090 and 52071159).
文摘Superhydrophobic materials are severely limited in their applications due to their weak mechanical properties and complex preparation process.In this paper,polystyrene/fluorinated silica(PS/SiO_(2))superhydrophobic composite coatings were prepared on the surface of 304 stainless steel using a simple one-step spraying method.The effects of different PS contents on the wettability as well as the wear properties of the samples were investigated.SiO_(2) was encapsulated in polystyrene to form a structure similar to cement encapsulated stones.With the addition of PS,a mound-like structure was formed on the sample surface,and a more optimized micro–nano structure was obtained when the content of PS was 0.6 g.At this time,the sample exhibited excellent wettability with a contact angle of 157.86°and a sliding angle of 0.84°.In addition,the contact angle of 151.09°was achieved after 180 cm of friction under a 100 g load and the composite coating prepared by this method also has excellent chemical stability,water impact resistance,corrosion resistance,and self-cleaning properties.This opens up new possibilities for the development of simple and robust superhydrophobic materials.
基金financially supported by Guangxi Natural Science Foundation of China (No.2020GXNSFAA159011)National Natural Science Foundation of China (No.51664011)。
文摘A longstanding quest in material science has been the development of superhydrophobic coating based on a single material, without the requirement of fluorination or silane treatment. In this work, the micro-arc oxidation(MAO) coating as transition layer can effectively enhance the bonding force of the superhydrophobic coating. The semiconductor@metal organic frameworks(MOFs) core-shell structure was synthesized by a simple self-templating method, and obtained ZnO@2-methylimidazole zinc salt(ZIF-8) nanorods array on magnesium(Mg)alloy. ZnO nanorods not only act as the template but also provide Zn^(2+) for ZIF-8. In addition, we proved that the ligand concentration,synthesis time and temperature are the keys to the preparation of ZnO@ZIF-8 nanorods. As we expect, the ZnO@ZIF-8 nanorods array can trap air in the gaps to form an air layer, and the coating exhibits superhydrophobic properties(154.81°). Excitingly, ZnO@ZIF-8 nanorods array shown a superhydrophobic property, without the requirement of fluorination or silane treatment. The results shown that the coating has good chemical stability and self-cleaning performance. Meanwhile, the corrosion resistance has been significantly improved, R_(ct) was increased from 1.044×10^(3) to 1.414×10^(6) Ω/cm^(2) and I_(corr) was reduced from 4.275×10^(-5) to 5.611×10^(-9)A/cm^2. Therefore, the semiconductor@MOFs core-shell structure has broad application prospects in anti-corrosion.
基金the financial support from National Key Research & Development Program of China (2017B0602702)。
文摘In this paper, the superhydrophobic polyurethane sponge(SS-PU) was facilely fabricated by etching with Jones reagent to bind the nanoparticles of Ni-Co double layered oxides(LDOs) on the surface, and following modification with n-dodecyl mercaptan(DDT). This method provides a new strategy to fabricate superhydrophobic PU sponge with a water contact angle of 157° for absorbing oil with low cost and in large scale. It exhibits the strong absorption capacity and highly selective characteristic for various kinds of oils which can be recycled by simple squeezing. Besides, the as-prepared sponge can deal with the floating and underwater oils, indicating its application value in handling oil spills and domestic oily wastewater. The good self-cleaning ability shows the potential to clear the pollutants due to the ultralow adhesion to water. Especially, the most important point is that the superhydrophobic sponge can continuously and effectively separate the oil/water mixture against the condition of turbulent disturbance by using our designed device system, which exhibit its good superhydrophobicity, strong stability.Furthermore, the SS-PU still maintained stable absorption performance after 150 cycle tests without losing capacity obviously, showing excellent durability in long-term operation and significant potential as an efficient absorbent in large-scale dispose of oily water.
基金supported by the National Natural Science Foundation of China(Grant Number 52172090 and 52071159).
文摘Bionic superhydrophobic coating has extremely broad application prospects and practical value. It is based on two important conditions, one is the construction of micro–nano structure, the other is the material with low surface energy. How to stabilize the micro–nano structure has become the focus of researches. In this work, a layer of Zn film is deposited on the stainless steel mesh with sturdy micron structure by RF magnetron sputtering. The solid micron structure of the stainless steel mesh itself, combined with the method of thermal oxidation, the surface of the stainless steel mesh is thus formed into a nanorod like ZnO nano structure, and then modified with perfluorodecyltriethoxysilane (PFDS) for low surface energy. The maximum contact angle of the superhydrophobic sample is 154.8°, and the minimum sliding angle is 2°, and it also has excellent corrosion resistance, thermal stability, self-cleaning, anti-aging and anti-icing properties, which provides a design idea for the preparation of superhydrophobic coatings.
基金The study was supported by the Russian Science Foundation grant no.22-73-10149,https://rscf.ru/project/22-73-10149/.
文摘A novel combined method for the formation of composite coatings on the Mg-Mn-Ce alloy is developed.Ceramic like matrix was formed on the Mg alloy surface by the plasma electrolytic oxidation.Then the samples were subsequently processed by dip-coating in an alcohol suspension of superdispersed polytetrafluoroethylene and spraying with the tetrafluoroethylene telomers solution.SEM,OSP,and SPM was used to study structure of formed surfaces.It was established by measurements of CA and CAH,as well as surface free energy calculations that formed coatings demonstrate superhydrophobic properties due to the presence of an irregular hierarchical surface structure and low surface free energy of fluoropolymers.The coating preserves its hydrophobic properties after exposure to high and low temperatures,for a long time as well as being in corrosive environments.EDS and XRD data analysis confirmed the presence of organofluorine compounds in the composite layers,including in the form of crystalline polytetrafluoroethylene.Using potentiodynamic polarization test and EIS,it was found that the resulting coatings significantly increase the corrosion resistance of Mg material.These data are also confirmed by salt spray tests for 40 days.Incorporation of fluoropolymers additionally decrease coatings coefficient of friction.
基金This work was financially supported by the National Key R&D Program of China(Grant No.2020YFB1711300)the National Natural Science Foundation of China(Grant No.52275425)the Natural Science Foundation of Guangdong Province for Distinguished Young Scholars(Grant No.2021B1515020087).
文摘Learning hydrophobic phenomena from nature is always a promising approach to design the superhydrophobic surface.Purple orchid leaf which processes superhydrophobicity is an ideal plant model,and through mimicking its structure,the surface with excellent hydrophobicity is able to be obtained.However,the unclear of the diversity in wettability during the different vegetation stages and the absence of its relation to the surface morphology limits the further enhancement of the inspired structure.Here,we analyze the wettability difference as the leaf grows from tender to mature and then to senescent.Combining with the variation of surface morphology and chemical composition,the well-developed micro-scale basic unit bumps with dense nano-scale waxy layer on the surface are proven to be responsible for the best hydrophobicity of the mature leaf.The presence of the undeveloped or damaged micro-nano hierarchical structure reduces the formation of air pockets at the interface,leading to the decrease of the wettability for leaves at other stages.Moreover,by fabricating artificial leaves,the nano-waxy layer is proved to be more effective than that of the micro-bumps on the surface wettability.The results of study are of a great significance for guiding the design and fabrication of plant-inspired bionic superhydrophobic surface.
基金supported by the National Science Fund for Distinguished Young Scholars (22125804)the National Natural Science Foundation of China (22008112, 22078155, and 21878149)+1 种基金the China Postdoctoral Science Foundation (2019M661813)the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘In atmospheric conditions, CuⅠis easily oxidized to CuⅡdue to the coexistence of moisture and oxygen.The poor oxidation inhibition of CuⅠrestricts the practical application of CuⅠ-containing materials.Herein we introduce an approach to construct a superhydrophobic microenvironment in CuⅠfunctionalized metal–organic frameworks by coordinatedly grafting organic amine compounds onto open metal sites(OMSs), which can hinder the accessibility of moisture to pores thereby enhancing the stability of CuⅠ. As a proof of concept, MIL-101(Cr) with abundant OMSs and octadecylamine(OA)with long hydrophobic alkyl groups are used as carrier and surface coating. As superhydrophobic porous materials, the resultant CuⅠM-OA exhibits improved CuⅠstability in addition to retaining high crystallinity and intact porosity while almost all CuⅠis oxidized in hydrophilic CuⅠM upon exposure in a humid atmosphere for 30 h. CuⅠM-OA owns excellent adsorption desulfurization performance(ADS) with regard to thiophene, benzothiophene, and 4,6-dimethyl dibenzothiophene. Even from hydrated fuel, the adsorption performance of CuⅠM-OA maintains well while the adsorption capacity of CuⅠM decreases to 7% after4 cycles. The remarkable moisture resistance, CuⅠstability, and high porosity make the current adsorbent CuⅠM-OA highly promising for the practical ADS process.
文摘Superhydrophobic(SH)coatings are intended to resist a surface from corrosion and thereby increases the product life duration.It is also a promising solution to save cleaning costs and time by providing self-clean nature to the surface.This review article provides the most recent updates in designing SH surfaces and their characterizations adopted both in experimental and computational techniques.To gain a comprehensive perspective,the SH surfaces present in nature those are inspiring human beings to mimic such surfaces are introduced at the beginning of this article.Subsequently,different fabrication techniques undertaken recently to design artificial SH surfaces are briefly discussed.Recent progress in computations employed in the development of SH surfaces is then discussed.Next,the limitations in SH surfaces are addressed.Finally,perceptiveness of different strategies and their limitations are presented in the concluding remarks and outlook.Overall,this mini review article brings together and highlights the significant advancements in fabrication of superhydrophobic surfaces which may surely help the early-stage researchers/scientists to plan their work accordingly.
文摘In the present review,the formation of superhydrophobic(SHP)structures on the surface of Mg alloys was investigated.Different methods including hydrothermal technique,chemical and electrochemical deposition,conversion and polymer coating,and etching routes were discussed.The superhydrophobicity could form on the surface of Mg alloys by the application of different chemical,electrochemical,and physical methods followed by the immersion of these alloys in the solution containing modifying agents including fatty acids or long-chain molecules.The formed morphology,composition,and contact angle were reported and the effect of synthesis route on these characteristics was reviewed.
文摘It is well known that surface roughness has a very important effect on superhydrophobicity.The Wenzel and Cassie-Baxtermodels,which correspond to the homogeneous and heterogeneous wetting respectively,are currently primary instructions fordesigning superhydrophobic surfaces.However,the particular drop shape that a drop exhibits might depend on how it is formed.A water drop can occupy multiple equilibrium states,which relate to different local minimal energy.In some cases,both equilibriumstates can even co-exist on a same substrate.Thus the apparent contact angles may vary and have different values.Wediscuss how the Wenzel and Cassie-Baxter equations determine the homogeneous and heterogeneous wetting theoretically.Contact angle analysis on hierarchical surface structure and contact angle hysteresis has been put specific attention.In particular,we study the energy barrier of transition from Cassie-Baxter state to Wenzel state,based on existing achievement by previousresearchers,to determine the possibility of the transition and how it can be interpreted.It has been demonstrated that surfaceroughness and geometry will influence the energy required for a drop to get into equilibrium,no matter it is homogeneous orheterogeneous wetting.
基金The authors are very grateful for the support from the National Key Research and Development Program of China(No.2016YFB0301102)the Fundamental Research Funds for the Central Universities(No.2018CDGFCL0005)the Postgraduate Education Fund of Chongqing University(No.201704020).
文摘A one-step electrodeposition method was used to construct a superhydrophobic coating on the surface of magnesium alloy.Using magne-sium nitrate and ethanol solution of stearic acid as electrolyte,four groups of electrolytes with different ratios of stearic acid and magnesium nitrate were designed to explore the influence of electrolyte to the process.The contact angles of the four coating samples were 136.4±5.8°,152.7±2.8°,156.2±4.9°and 155.1±4.4°The addition of magnesium nitrate in the solution increased the hydrogen evolution reaction in the electrodeposition process,which was not conducive to electrodeposition process.During the deposition process,the sample prepared in a molar ratio of stearic acid to magnesium nitrate of 10:1 had the best corrosion resistance,and its corrosion circuit density was 3.74×10^(−8)A/cm^(2),far lower than the corrosion current density of the magnesium alloy substrate.
基金supported by National Nature Science Foundation of China(51977079,51607067)Youth Elite Scientists Sponsorship Program by Chinese Society for Electrical Engineering(CSEE-YESS-2017002)the Fundamental Research Funds for the Central Universities(2020MS115,2017MS149).
文摘Although superhydrophobic materials have attracted much research interest in anti-icing,some controversy still exists.In this research,we report a cost-effective method used to verify the contribution of area fraction to ice adhesion strength.We tried to partially-embed siliea nanopnarticles into microscale fabrics of a commercial polyamide mesh.Then,the area fraction could be determined by altering the mesh size.Generally,the ice adhesion strength decreases as the area fraction decreases.An ice adhesion strength of~1.9 kPa and a delayed freezing time of~1048 s can be obtained.We attribute the low ice adhesion strength to the combination of superhydro-phobicity and stress concentration.The superhydrophobicity prohibits the water from penetrating into the voids of the meshes,and the small actual contact area leads to stress concentration which promotes interfacial crack propagation.Moreover,our superhydrophobic mesh simultaneously exhibis a micro-nano hierarchical structure and a partally-cmbedded structure.Therefore,the as-prepared superhydrophobic mesh retained the ieephobicity after 20 icingldeicing cycles,and maintained its superhydrophobicity even afier 60 sandpaper-abrasion cycles and a 220"C thermal treatment.
