In order to improve the corrosion resistance of the Mg alloys, the superhydrophobic coatings on AZ31 Mg alloy wereprepared by a two-step process of micro-arc oxidation treatment and superhydrophobic treatment in stear...In order to improve the corrosion resistance of the Mg alloys, the superhydrophobic coatings on AZ31 Mg alloy wereprepared by a two-step process of micro-arc oxidation treatment and superhydrophobic treatment in stearic acid ethanol solution. Theeffects of voltages, frequencies and treatment time on the contact angle of the superhydrophobic treated sample were investigated.The results showed that with increasing the voltage, frequency and treatment time, all of the contact angles of the superhydrophobictreated sample increased first, and then decreased, reaching the maximum values at 350 V, 1000 Hz and 5 min, respectively. Theoptimal superhydrophobic coating was mainly composed of MgO and Mg2SiO4 phases, with the pore diameter of ～900 nm, thethickness of ～6.86 μm and the contact angle of 156.96°. The corrosion current density of the superhydrophobic AZ31 sampledecreased by three orders of magnitude, and the amount of hydrogen evolution decreased by 94.77% compared with that of the AZ31substrate sample.展开更多
Superhydrophobic coatings with high non-wetting properties are widely applied in anti-icing applications.However,the micro-nanostructures on the surfaces of superhydrophobic coatings are fragile under external forces,...Superhydrophobic coatings with high non-wetting properties are widely applied in anti-icing applications.However,the micro-nanostructures on the surfaces of superhydrophobic coatings are fragile under external forces,resulting in reduced durability.Therefore,mechanical strength and durability play a crucial role in the utilization of superhydrophobic materials.In this study,we employed a two-step spraying method to fabricate superhydrophobic FEVE-based coatings with exceptional mechanical durability,utilizing fluorinated TiO_(2)nanoparticles and fluorinated Al_(2)O_(3)microwhiskers as the fillers.The composite coating exhibited commendable non-wetting properties,displaying a contact angle of 164.84°and a sliding angle of 4.3°.On this basis,the stability of coatings was significantly improved due to the interlocking effect of Al_(2)O_(3)whiskers.After 500 tape peeling cycles,500 sandpaper abrasion tests,and 50 kg falling sand impact tests,the coatings retained superhydrophobicity,exhibiting excellent durability and application capability.Notably,the ice adhesion strength on the coatings was measured at only 65.4 kPa,while the icing delay time reached 271.8 s at-15℃.In addition,throughout 500 freezing/melting cycles,statistical analysis revealed that the superhydrophobic coatings exhibited a freezing initiation temperature as low as-17.25℃.展开更多
Magnesium(Mg)alloys show great potential to be extensively applied in practice owing to their superior properties,while the poor corrosion resistance does undoubtedly restrict their applications.Superhydrophobic coati...Magnesium(Mg)alloys show great potential to be extensively applied in practice owing to their superior properties,while the poor corrosion resistance does undoubtedly restrict their applications.Superhydrophobic coatings with good repellency to corrosive solutions can significantly decrease the interaction between the corrosive species and the substrate,so that they are receiving a lot of attention to improve the corrosion resistance of Mg alloys.Various strategies have been introduced to develop a superhydrophobic coating on Mg alloys,which were reviewed to elucidate the current research status to provide a clue or thinking for beginning researchers.Further,the existing issues of superhydrophobic coating were discussed,especially for their real applications in practice,mainly owing to their poor mechanical stability.Based on the existing issues,the future study was discussed to improve the stability of hierarchical structures and entrapped air pockets,impart the superhydrophobic coating self-healing property to repair the damaged area during service,provide double protection by incorporation of corrosion inhibitors,or even introduce slippery liquid-infused porous surfaces with lubricant layer to provide better corrosion protection for Mg alloys.展开更多
Excellent mechanical properties are the prerequisite for the application of superhydrophobic polymer coatings.However,significantly improving the mechanical properties without affecting other properties such as hydrop...Excellent mechanical properties are the prerequisite for the application of superhydrophobic polymer coatings.However,significantly improving the mechanical properties without affecting other properties such as hydrophobicity is a huge challenge.In this study,a superhydrophobic coating with excellent mechanical properties was prepared by spraying a mixture of polysiloxane resins based on three siloxane monomers,hexadecyltrimethoxysilane(HDTMS) modified nano-SiO_(2)particles(SiO_(2)-HDTMS) and polystyrene-grafted halloysite nanotubes(HNTs-PS).SiO_(2)-HDTMS dispersed homogeneously in polysiloxane coatings and the water contact angle of corresponding coating exceeding 150°,achieving superhydrophobicity.The SiO_(2)-HDTMS/HNTs-PS/polysiloxane composite coatings showed excellent abrasion resistance with the water coating contact angle remaining above 150°after 90 abrasion cycles,indicating that HNTs-PS can significantly improve the mechanical properties of the coating without affecting the hydrophobic properties of the coating.The achieved coating also exhibited excellent antifouling and acid and alkali corrosion resistance.This work provides a convenient and ecologically friendly method to prepare superhydrophobic polysiloxane composite coating with excellent mechanical properties,which is promising in the application of anti-fouling,anti-corrosion,and oil-water separation etc.展开更多
Plastic waste is an underutilized resource that has the potential to be transformed into value-added materials.However,its chemical diversity leads to cost-intensive sorting techniques,limiting recycling and upcycling...Plastic waste is an underutilized resource that has the potential to be transformed into value-added materials.However,its chemical diversity leads to cost-intensive sorting techniques,limiting recycling and upcycling opportunities.Herein,we report an open-loop recycling method to produce graded feedstock from mixed polyolefins waste,which makes up 60%of total plastic waste.The method uses heat flow scanning to quantify the composition of plastic waste and resolves its compatibility through controlled dissolution.The resulting feedstock is then used to synthesize blended pellets,porous sorbents,and superhydrophobic coatings via thermally induced phase separation and spin-casting.The hybrid approach broadens the opportunities for reusing plastic waste,which is a step towards creating a more circular economy and better waste management practices.展开更多
Magnesium(Mg)is a vital engineering material owing to its light weight and excellent mechanical properties.However,poor corrosion resistance limits its widely applications as well as its economic value.Hence,surface m...Magnesium(Mg)is a vital engineering material owing to its light weight and excellent mechanical properties.However,poor corrosion resistance limits its widely applications as well as its economic value.Hence,surface modification is essential for Mg and its alloys.Among the various coatings,superhydrophobic coating,which is inspired by nature,has received increasing attentions in the past decade.With a water contact angle larger than 150°,superhydrophobic coating can provide sufficient protection for Mg-based substrates.The model of superhydrophobic states and the protection mechanism of superhydrophobic coating are discussed in this review.Especially,the methods for fabricating superhydrophobic coatings on Mg alloys are reviewed.Meanwhile,some functional superhydrophobic coatings on Mg alloys are summarized.Finally,the challenges and future directions are proposed.We hope that this paper will provide a serviceable review for future research on superhydrophobic coatings on Mg alloys.展开更多
In this paper,the superhydrophobic poly(vinylidene fuoride)/fuorinated ethylene propylene/SiO_(2)/CNTs-EDTA(PFSCEDTA)composite coating was successfully fabricated and applied for anti-scaling performance.The depositio...In this paper,the superhydrophobic poly(vinylidene fuoride)/fuorinated ethylene propylene/SiO_(2)/CNTs-EDTA(PFSCEDTA)composite coating was successfully fabricated and applied for anti-scaling performance.The deposition of CaCO_(3) on the surface of the superhydrophobic PFSC-EDTA composite coating reached 0.0444 mg/cm^(2) for 192-h immersion into the supersaturated CaCO_(3) solution,which was only 11.4%that of the superhydrophobic PFSC composite coating.At the interface between the CaCO_(3) solution and the PFSC-EDTA coating,the Ca^(2+)could be frstly chelated by EDTA that was beneft for improving the anti-scaling performance of the superhydrophobic PFSC-EDTA composite coating.In another hand,the addition of EDTA to the CNTs played an important role in fabricating the SiO_(2)-centric and CNTs-EDTA-surrounded multilevel micro-nanostructure in the superhydrophobic PFSC-EDTA composite coating,in favor of maintaining the air flm under the water and the stability of the superhydrophobic surface.The research supplies a new way of improving antiscaling performance of superhydrophobic coating by incorporating the organic chelating agent at the interface and changing the traditional way of scale prevention.展开更多
Superhydrophobic coating has been widely studied for its great applicational potential, such as for corrosion protection of magnesium alloys while it has been restrained by expensive materials, sophisticated preparati...Superhydrophobic coating has been widely studied for its great applicational potential, such as for corrosion protection of magnesium alloys while it has been restrained by expensive materials, sophisticated preparation process and infirm rough structures. In this study, the electrochemical method was adopted by using a two-electrode system for rapid hydrophobic modification to obtain superhydrophobic kaolin.By mixing the modified superhydrophobic kaolin with commercial epoxy resin and polydimethylsiloxane glue, a paint can be formed and easily used on various substrates for preparation of superhydrophobic coating via spraying method. The influence factors on wettability of the modified kaolin and the mixing ratio of each component of the coating were explored. Also, the wettability, durability and anticorrosion of the prepared coating were evaluated comprehensively. The coating was able to maintain superhydrophobic after immersed in HCl solution at pH 1, the NaOH solution at pH 14, and 3.5 wt.% NaCl solution for 16, 21, 30 days, respectively. In addition, the coating exhibited 4A grade adhesion, high hydrophobicity after abraded for 200 cycles on a 600-mesh sandpaper with 100 g weight, and 99.86% anticorrosion efficiency after soaked in 3.5 wt.% NaCl solution for 20 days, demonstrating a good robustness and anti-corrosion property. Furthermore, the coating showed good transparency, flexibility and was easy to make in a large scale by the spraying method, which is of great significance to promote the practical application of superhydrophobic coatings and the anticorrosion Mg alloys.展开更多
In recent years, superhydrophobic media has attracted tremendous attention due to its industrial applicability value, especially in anti-corrosion performance. The superhydrophobic coating, which has a robust and wate...In recent years, superhydrophobic media has attracted tremendous attention due to its industrial applicability value, especially in anti-corrosion performance. The superhydrophobic coating, which has a robust and water-repellent capacity, can catch the air to form several “airbags” on the substrate’s surface, isolating the corrosion media. Various superhydrophobic coating preparation technologies have been suggested, but each has its own set of flaws. On the other hand, electrodeposition, as a relatively mature industrial processing application, offers distinct advantages. However, until now, there have been few reviews on the electrodeposition preparation of anticorrosive superhydrophobic coatings. Therefore, the author has described several fabrication techniques based on superhydrophobic coatings in this review, including the advantages and disadvantages. Superhydrophobic coatings conventional concepts and wettability, as well as the model wetting concepts, have been reviewed. The coating processing status and the corrosion-resistant potential through the electrodeposition of metal and comparable composite are detailly encapsulated. Furthermore, electrodeposition parameters, including current density, crystal modifiers, and a deposition time of the coating morphology, are reported, following the ultrasonic-assisted, jet, pulse, and magnetic field-induced electrodeposition, respectively, as the recently developed technologies for preparing a coating. Finally, technology limitation is shown as well as the obstacles and prospects, and the improvement of the superhydrophobic coating’s durability as a prospects research focus has been recommended.展开更多
The formation of superhydrophobic coatings using low-toxicity corrosion inhibitors is a promising method for corrosion protection of metals and alloys. In this study, the effects of surface roughness and the of the ad...The formation of superhydrophobic coatings using low-toxicity corrosion inhibitors is a promising method for corrosion protection of metals and alloys. In this study, the effects of surface roughness and the of the adsorbed substance structure on wettability and corrosion resistance of commercially pure magnesium were investigated. Surface roughness was created by three different methods: paper grinding,etching in nitric acid solution and laser treatment. Oleic, stearic and octadecylphosphonic acids were investigated as potential surface modifiers for the formation of corrosion resistant superhydrophobic coatings. It has been shown that the protective and hydrophobic properties of acid films on magnesium, as well as their stability, are determined by both the initial surface morphology and the nature of the inhibitors.Experimentally, the laser treatment was found to be preferable to mechanical and chemical surface preparation and the best hydrophobic agent among the studied acids is phosphonic acid. The most stable films with excellent superhydrophobic and protective properties in atmospheres of high humidity and salt spray clamber are formed in a solution of 0.001 M octadecylphosphonic acid on the surface of magnesium with high roughness. In addition, the effect of vinyltrimethoxysilane on the protective and hydrophobic properties of stearic acid and octadecylphosphonic acid films was investigated. The results of direct corrosion tests and wetting contact angle degradation kinetics studies showed that the protective and hydrophobic properties of stearic acid can be enhanced by its layer-by-layer adsorption with silane.They practically reach the parameters of octadecylphosphonic acid.展开更多
The coating-modified magnesium(Mg)alloys exhibit controllable corrosion resistance,but the insufficient antibacterial performance limits their clinical applications as degradable implants.Superhydrophobic coatings sho...The coating-modified magnesium(Mg)alloys exhibit controllable corrosion resistance,but the insufficient antibacterial performance limits their clinical applications as degradable implants.Superhydrophobic coatings show excellent performance in terms of both corrosion resistance and inhibition of bacterial adhesion and growth.In this work,a hydroxyapatite(HA)/palmitic acid(PA)superhydrophobic composite coating was fabricated on the Mg alloy by the hydrothermal technique and immersion treatment.The HA/PA composite coating showed superhydrophobicity with a contact angle of 153°and a sliding angle of 2°.The coated Mg alloy exhibited excellent corrosion resistance in the simulated body fluid,with high polarization resistance(77.10 kΩ·cm^(2))and low corrosion current density((0.491±0.015)μA·cm^(-2)).Meanwhile,the antibacterial efficiency of the composite coating was over 98% against E.coli and S.aureus in different periods.The results indicate that the construction of such superhydrophobic composite coating(HA/PA)on the Mg alloy can greatly improve the corrosion resistance of Mg alloy implants within the human body and avoid bacterial infection during the initial stages of implantation.展开更多
Superhydrophobic coatings with high flexibility and mechanical durability can well address many practical application problems.To this end,we proposed and fabricated a kind of bio-based superhydrophobic(multi-walled c...Superhydrophobic coatings with high flexibility and mechanical durability can well address many practical application problems.To this end,we proposed and fabricated a kind of bio-based superhydrophobic(multi-walled carbon nanotubes)CNT@PU(polyurethane)coatings.It was demonstrated that the CNT@PU coatings with 64%soft segment content possessed the preferable bonding strength(5B)with metal substrates.The multi-walled carbon nanotubes,as additive materials,were used to construct the microscopic structures of the coating surfaces,which made polyurethane surface superhydrophobic(water contact angle being 156.9°,and water sliding angle being 4.3°).Furthermore,the high bonding strength between CNT and coating matrix led to robust mechanical durability of supertiydrophobic CNT@PU coatings,and the coatings remained superhydrophobicity after 10 cycles of abrasion under 100 g load pressure.Also,the superhydrophobic coatings could well resist 5 cycles of tape-peeling action,and presented outstanding flexibility.The supernydrophobic CNT@PU coatings with high flexibility and mechanical durability could be applied to various substrates suggesting their big potential in future real-world application.展开更多
Durable electromagnetic interference(EMI)shielding is highly desired,as electromagnetic pollution is a great concern for electronics’stable performance and human health.Although a superhydrophobic surface can extend ...Durable electromagnetic interference(EMI)shielding is highly desired,as electromagnetic pollution is a great concern for electronics’stable performance and human health.Although a superhydrophobic surface can extend the service lifespan of EMI shielding materials,degradation of its protection capability and insufficient self-healing are troublesome issues due to unavoidable physical/chemical damages under long-term application conditions.Here,we report,for the first time,an instantaneously self-healing approach via microwave heating to achieve durable shielding performance.First,a hydrophobic 1H,1H,2H,2H-perfluorooctyltriethoxysilane(POTS)layer was coated on a polypyrrole(PPy)-modified fabric(PPy@POTS),enabling protection against the invasion of water,salt solution,and corrosive acidic and basic solutions.Moreover,after being damaged,the POTS layer can,for the first time,be instantaneously self-healed via microwave heating for a very short time,i.e.,4 s,benefiting from the intense thermal energy generated by PPy under electromagnetic wave radiation.This self-healing ability is also repeatable even after intentionally severe plasma etching,which highlights the great potential to achieve robust and durable EMI shielding applications.Significantly,this approach can be extended to other EMI shielding materials where heat is a triggering stimulus for healing thin protection layers.We envision that this work could provide insights into fabricating EMI shielding materials with durable performance for portable and wearable devices,as well as for human health care.展开更多
In this study,micro/nanostructures are fabricated on the surface of 3Cr13 stainless steel via laser etching,and a superhydrophobic coating with silver nanoparticles(AgNPs)is prepared by utilizing the reduction–adsorp...In this study,micro/nanostructures are fabricated on the surface of 3Cr13 stainless steel via laser etching,and a superhydrophobic coating with silver nanoparticles(AgNPs)is prepared by utilizing the reduction–adsorption properties of polydopamine(PDA).We investigate the effect of soaking time from the“one-step method”on the reduction of nano-Ag,surface wettability,and antibacterial properties.Scanning electron microscopy is performed to analyze the distribution of nano-Ag on the surface,whereas X-ray energy dispersive spectroscopy and X-ray photoelectron spectroscopy are used to analyze the crystal structures and chemical compositions of different surfaces.Samples deposited with PDA on their surface are soaked in a 1H,1H,2H,2H-perfluorodecyltriethoxysilane water–alcohol solution containing AgNO3 for 3 h.Subsequently,a“one-step method”is used to prepare low-adhesion superhydrophobic surfaces containing AgNPs.As immersion progresses,more AgNPs are deposited onto the surface.Compared with the polished surface,the samples prepared via the“one-step method”show significant antibacterial properties against both gram-negative Escherichia coli and gram-positive Staphylococcus aureus.The antibacterial properties of the surface improve as immersion progresses.展开更多
Biomimetic superhydrophobic(SH)coatings have emerged as a promising alternative to traditional room temperature vulcanizing(RTV)silicone rubber coatings for improving the flashover strength of insulators.However,organ...Biomimetic superhydrophobic(SH)coatings have emerged as a promising alternative to traditional room temperature vulcanizing(RTV)silicone rubber coatings for improving the flashover strength of insulators.However,organic contamination occurs in outdoor applications and thus a superamphiphobic(SAP)surface is more desirable but not yet reported for improving flashover performance.Herein,we developed a novel anti-flashover technique by fabricating robust SAP coating with unique gradient and micro-nanoscale hierarchical architecture.The SAP coating was fabricated by sequentially spray-depositing a resin-based primer and a silica-based topcoat on substrates(i.e.,glass slides and insulators).The primer not only functions as an adhesive offering strong adhesion to the substrate but also offers a micromastoid-like structure facilitating the subsequent formation of hierarchical micro-nanostructure.The appropriate spraying pressure leads to a diffusion of the fluorocarbon-modified silica nanoparticles into the primer to form a unique gradient structure,by analogy to inserting bullets into a wood.These features render the SAP coating excellent robustness with strong abrasive resistance,excellent ultraviolet(UV)resistance,and excellent chemical and thermal stability.Pollution flashover property of the SAP coating was explored and compared with that of SH and RTV specimens,from which a novel organic-contamination model to evaluate the flashover performance was proposed.The coated SAP glass insulator demonstrated 42.9%pollution flashover voltage improvement than RTV-coated insulator.These stated unique features reveal the convincing potential of the present SAP coatings to be applied for not only outdoor transmission line insulators for antiflashover but also other fields for self-cleaning,anti-fouling,and anti-icing.展开更多
A micro-arc oxidation（MAO）/zinc stearate（ZnSA） composite coating was fabricated via MAO processing and subsequent sealing with electrodeposition of a superhydrophobic ZnSA. The surface morphologies,chemical compos...A micro-arc oxidation（MAO）/zinc stearate（ZnSA） composite coating was fabricated via MAO processing and subsequent sealing with electrodeposition of a superhydrophobic ZnSA. The surface morphologies,chemical composition and corrosion resistance of the coatings were investigated using field-emission scanning electron microscopy, Fourier transform infrared, X-ray diffraction and electrochemical and hydrogen evolution measurements. Results indicated that the MAO coating was efficiently sealed by the following superhydrophobic ZnSA coating. The MAO/ZnSA composite coating significantly enhanced the corrosion resistance of Mg alloy Mg-4 Li-1 Ca due to its superhydrophobic function. Additionally, corrosion mechanism was suggested and discussed for the composite coating.展开更多
A low-cost method was used to fabricate superhydrophobic coatings on a macroscopic model ship and the drag-reducing effect was investigated at both low and high speed. Hierarchical structures of the superhydrophobic c...A low-cost method was used to fabricate superhydrophobic coatings on a macroscopic model ship and the drag-reducing effect was investigated at both low and high speed. Hierarchical structures of the superhydrophobic copper coatings were characterized by means of scanning electron microscopy（SEM） and X-ray diffraction（XRD）. Drag coefficient tests on surfaces with different wettability（superhydrophilic, hydrophilic, hydrophobic and superhy- drophobic surfaces） showed that the as-prepared superhydrophobic surface exhibited a high remarkable drag reduction of 81% at a low speed of 1 mm/s. In the drag-reducing tests with model ship, the superhydrophobic coatings also exhibited around 16% drag reduction at a velocity of 0.3 m/s.展开更多
基金Project(51101085)supported by the National Natural Science Foundation of ChinaProject(2016BAB206109)supported by the Natural Science Foundation of Jiangxi Province,China+6 种基金Project(BK20151291)supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(BRA2015377)supported by the 333 Project of Jiangsu Province,ChinaProject(20151BBG70039)supported by the Science and Technology Support Plan of Jiangxi Province,ChinaProject(GJJ150721)supported by the Science and Technology Project of Jiangxi Province Education Department,ChinaProject(HAG201601)supported by the Foundation of Huaian Science and Technology,ChinaProject(HAC2015026)supported by the Huaian International Cooperation Program,ChinaProject(jr1416)supported by the Foundation of Jiangsu Provincial Key Laboratory for Interventional Medical Devices,China
文摘In order to improve the corrosion resistance of the Mg alloys, the superhydrophobic coatings on AZ31 Mg alloy wereprepared by a two-step process of micro-arc oxidation treatment and superhydrophobic treatment in stearic acid ethanol solution. Theeffects of voltages, frequencies and treatment time on the contact angle of the superhydrophobic treated sample were investigated.The results showed that with increasing the voltage, frequency and treatment time, all of the contact angles of the superhydrophobictreated sample increased first, and then decreased, reaching the maximum values at 350 V, 1000 Hz and 5 min, respectively. Theoptimal superhydrophobic coating was mainly composed of MgO and Mg2SiO4 phases, with the pore diameter of ～900 nm, thethickness of ～6.86 μm and the contact angle of 156.96°. The corrosion current density of the superhydrophobic AZ31 sampledecreased by three orders of magnitude, and the amount of hydrogen evolution decreased by 94.77% compared with that of the AZ31substrate sample.
基金financial support from the National Natural Science Foundation of China(No.52075246,U2341264)Natural Science Foundation of Jiangsu Province(No.BK20211568)+4 种基金International Cooperation Project of Jiangsu Province(No.BZ2023045)National Science and Technology Major Project of China(No.J2019-III-0010-0054)Fundamental Research Funds for the Central Universities(No.NE2022005)Liaoning Provincial Key Laboratory of Aircraft Ice Protection(No.XFX20220301)Basic Research Project of Suzhou(No.SJC2022032)。
文摘Superhydrophobic coatings with high non-wetting properties are widely applied in anti-icing applications.However,the micro-nanostructures on the surfaces of superhydrophobic coatings are fragile under external forces,resulting in reduced durability.Therefore,mechanical strength and durability play a crucial role in the utilization of superhydrophobic materials.In this study,we employed a two-step spraying method to fabricate superhydrophobic FEVE-based coatings with exceptional mechanical durability,utilizing fluorinated TiO_(2)nanoparticles and fluorinated Al_(2)O_(3)microwhiskers as the fillers.The composite coating exhibited commendable non-wetting properties,displaying a contact angle of 164.84°and a sliding angle of 4.3°.On this basis,the stability of coatings was significantly improved due to the interlocking effect of Al_(2)O_(3)whiskers.After 500 tape peeling cycles,500 sandpaper abrasion tests,and 50 kg falling sand impact tests,the coatings retained superhydrophobicity,exhibiting excellent durability and application capability.Notably,the ice adhesion strength on the coatings was measured at only 65.4 kPa,while the icing delay time reached 271.8 s at-15℃.In addition,throughout 500 freezing/melting cycles,statistical analysis revealed that the superhydrophobic coatings exhibited a freezing initiation temperature as low as-17.25℃.
基金financially supported by the National Natural Science Foundation of China(Nos.51971040,51701029,51531002)the National Key Research and Development Program of China(No.2016YFB0301100)。
文摘Magnesium(Mg)alloys show great potential to be extensively applied in practice owing to their superior properties,while the poor corrosion resistance does undoubtedly restrict their applications.Superhydrophobic coatings with good repellency to corrosive solutions can significantly decrease the interaction between the corrosive species and the substrate,so that they are receiving a lot of attention to improve the corrosion resistance of Mg alloys.Various strategies have been introduced to develop a superhydrophobic coating on Mg alloys,which were reviewed to elucidate the current research status to provide a clue or thinking for beginning researchers.Further,the existing issues of superhydrophobic coating were discussed,especially for their real applications in practice,mainly owing to their poor mechanical stability.Based on the existing issues,the future study was discussed to improve the stability of hierarchical structures and entrapped air pockets,impart the superhydrophobic coating self-healing property to repair the damaged area during service,provide double protection by incorporation of corrosion inhibitors,or even introduce slippery liquid-infused porous surfaces with lubricant layer to provide better corrosion protection for Mg alloys.
基金supported by the National Natural Science Foundation of China(21878092,21838003,91834301 and 51621002)the Shanghai Scientific and Technological Innovation Project(19JC1410400)+2 种基金Program of Shanghai Academic Research Leader(19XD1401400)the Innovation Program of Shanghai Municipal Education Commissionthe Fundamental Research Funds for the Central Universities(222201718002)。
文摘Excellent mechanical properties are the prerequisite for the application of superhydrophobic polymer coatings.However,significantly improving the mechanical properties without affecting other properties such as hydrophobicity is a huge challenge.In this study,a superhydrophobic coating with excellent mechanical properties was prepared by spraying a mixture of polysiloxane resins based on three siloxane monomers,hexadecyltrimethoxysilane(HDTMS) modified nano-SiO_(2)particles(SiO_(2)-HDTMS) and polystyrene-grafted halloysite nanotubes(HNTs-PS).SiO_(2)-HDTMS dispersed homogeneously in polysiloxane coatings and the water contact angle of corresponding coating exceeding 150°,achieving superhydrophobicity.The SiO_(2)-HDTMS/HNTs-PS/polysiloxane composite coatings showed excellent abrasion resistance with the water coating contact angle remaining above 150°after 90 abrasion cycles,indicating that HNTs-PS can significantly improve the mechanical properties of the coating without affecting the hydrophobic properties of the coating.The achieved coating also exhibited excellent antifouling and acid and alkali corrosion resistance.This work provides a convenient and ecologically friendly method to prepare superhydrophobic polysiloxane composite coating with excellent mechanical properties,which is promising in the application of anti-fouling,anti-corrosion,and oil-water separation etc.
基金NPRP grant number NPRP12S-0325-190443 from the Qatar National Research Fund (a member of the Qatar Foundation)
文摘Plastic waste is an underutilized resource that has the potential to be transformed into value-added materials.However,its chemical diversity leads to cost-intensive sorting techniques,limiting recycling and upcycling opportunities.Herein,we report an open-loop recycling method to produce graded feedstock from mixed polyolefins waste,which makes up 60%of total plastic waste.The method uses heat flow scanning to quantify the composition of plastic waste and resolves its compatibility through controlled dissolution.The resulting feedstock is then used to synthesize blended pellets,porous sorbents,and superhydrophobic coatings via thermally induced phase separation and spin-casting.The hybrid approach broadens the opportunities for reusing plastic waste,which is a step towards creating a more circular economy and better waste management practices.
基金financially supported by the China Postdoctoral Science Foundation(2019M662830)the National Natural Science Foundation of China(31771044)+2 种基金the National Key Research and Development Program of China(2016YFC1100604)Shanghai Committee of Science and Technology,China(184107606000)International Partnership Program of Chinese Academy of Sciences(GJHZ1850)。
文摘Magnesium(Mg)is a vital engineering material owing to its light weight and excellent mechanical properties.However,poor corrosion resistance limits its widely applications as well as its economic value.Hence,surface modification is essential for Mg and its alloys.Among the various coatings,superhydrophobic coating,which is inspired by nature,has received increasing attentions in the past decade.With a water contact angle larger than 150°,superhydrophobic coating can provide sufficient protection for Mg-based substrates.The model of superhydrophobic states and the protection mechanism of superhydrophobic coating are discussed in this review.Especially,the methods for fabricating superhydrophobic coatings on Mg alloys are reviewed.Meanwhile,some functional superhydrophobic coatings on Mg alloys are summarized.Finally,the challenges and future directions are proposed.We hope that this paper will provide a serviceable review for future research on superhydrophobic coatings on Mg alloys.
基金The research was fnancially supported by the National Science Foundation for Distinguished Young Scholars of China(Grant No.51925403)the Major Research Plan of National Natural Science Foundation of China(Grant No.91934302)the National Science Foundation of China(21676052,21606042).
文摘In this paper,the superhydrophobic poly(vinylidene fuoride)/fuorinated ethylene propylene/SiO_(2)/CNTs-EDTA(PFSCEDTA)composite coating was successfully fabricated and applied for anti-scaling performance.The deposition of CaCO_(3) on the surface of the superhydrophobic PFSC-EDTA composite coating reached 0.0444 mg/cm^(2) for 192-h immersion into the supersaturated CaCO_(3) solution,which was only 11.4%that of the superhydrophobic PFSC composite coating.At the interface between the CaCO_(3) solution and the PFSC-EDTA coating,the Ca^(2+)could be frstly chelated by EDTA that was beneft for improving the anti-scaling performance of the superhydrophobic PFSC-EDTA composite coating.In another hand,the addition of EDTA to the CNTs played an important role in fabricating the SiO_(2)-centric and CNTs-EDTA-surrounded multilevel micro-nanostructure in the superhydrophobic PFSC-EDTA composite coating,in favor of maintaining the air flm under the water and the stability of the superhydrophobic surface.The research supplies a new way of improving antiscaling performance of superhydrophobic coating by incorporating the organic chelating agent at the interface and changing the traditional way of scale prevention.
基金the financial support of the National Natural Science Foundation of China (Grant No. 21978182)。
文摘Superhydrophobic coating has been widely studied for its great applicational potential, such as for corrosion protection of magnesium alloys while it has been restrained by expensive materials, sophisticated preparation process and infirm rough structures. In this study, the electrochemical method was adopted by using a two-electrode system for rapid hydrophobic modification to obtain superhydrophobic kaolin.By mixing the modified superhydrophobic kaolin with commercial epoxy resin and polydimethylsiloxane glue, a paint can be formed and easily used on various substrates for preparation of superhydrophobic coating via spraying method. The influence factors on wettability of the modified kaolin and the mixing ratio of each component of the coating were explored. Also, the wettability, durability and anticorrosion of the prepared coating were evaluated comprehensively. The coating was able to maintain superhydrophobic after immersed in HCl solution at pH 1, the NaOH solution at pH 14, and 3.5 wt.% NaCl solution for 16, 21, 30 days, respectively. In addition, the coating exhibited 4A grade adhesion, high hydrophobicity after abraded for 200 cycles on a 600-mesh sandpaper with 100 g weight, and 99.86% anticorrosion efficiency after soaked in 3.5 wt.% NaCl solution for 20 days, demonstrating a good robustness and anti-corrosion property. Furthermore, the coating showed good transparency, flexibility and was easy to make in a large scale by the spraying method, which is of great significance to promote the practical application of superhydrophobic coatings and the anticorrosion Mg alloys.
文摘In recent years, superhydrophobic media has attracted tremendous attention due to its industrial applicability value, especially in anti-corrosion performance. The superhydrophobic coating, which has a robust and water-repellent capacity, can catch the air to form several “airbags” on the substrate’s surface, isolating the corrosion media. Various superhydrophobic coating preparation technologies have been suggested, but each has its own set of flaws. On the other hand, electrodeposition, as a relatively mature industrial processing application, offers distinct advantages. However, until now, there have been few reviews on the electrodeposition preparation of anticorrosive superhydrophobic coatings. Therefore, the author has described several fabrication techniques based on superhydrophobic coatings in this review, including the advantages and disadvantages. Superhydrophobic coatings conventional concepts and wettability, as well as the model wetting concepts, have been reviewed. The coating processing status and the corrosion-resistant potential through the electrodeposition of metal and comparable composite are detailly encapsulated. Furthermore, electrodeposition parameters, including current density, crystal modifiers, and a deposition time of the coating morphology, are reported, following the ultrasonic-assisted, jet, pulse, and magnetic field-induced electrodeposition, respectively, as the recently developed technologies for preparing a coating. Finally, technology limitation is shown as well as the obstacles and prospects, and the improvement of the superhydrophobic coating’s durability as a prospects research focus has been recommended.
基金funded by the Ministry of Science and Higher Education of the Russian Federation (122011300078-1)。
文摘The formation of superhydrophobic coatings using low-toxicity corrosion inhibitors is a promising method for corrosion protection of metals and alloys. In this study, the effects of surface roughness and the of the adsorbed substance structure on wettability and corrosion resistance of commercially pure magnesium were investigated. Surface roughness was created by three different methods: paper grinding,etching in nitric acid solution and laser treatment. Oleic, stearic and octadecylphosphonic acids were investigated as potential surface modifiers for the formation of corrosion resistant superhydrophobic coatings. It has been shown that the protective and hydrophobic properties of acid films on magnesium, as well as their stability, are determined by both the initial surface morphology and the nature of the inhibitors.Experimentally, the laser treatment was found to be preferable to mechanical and chemical surface preparation and the best hydrophobic agent among the studied acids is phosphonic acid. The most stable films with excellent superhydrophobic and protective properties in atmospheres of high humidity and salt spray clamber are formed in a solution of 0.001 M octadecylphosphonic acid on the surface of magnesium with high roughness. In addition, the effect of vinyltrimethoxysilane on the protective and hydrophobic properties of stearic acid and octadecylphosphonic acid films was investigated. The results of direct corrosion tests and wetting contact angle degradation kinetics studies showed that the protective and hydrophobic properties of stearic acid can be enhanced by its layer-by-layer adsorption with silane.They practically reach the parameters of octadecylphosphonic acid.
基金the National Natural Science Foundation of China(Grant Nos.52271246 and 82272533)the Shanghai Sailing Program(Grant No.21YF1458200)for providing financial support.
文摘The coating-modified magnesium(Mg)alloys exhibit controllable corrosion resistance,but the insufficient antibacterial performance limits their clinical applications as degradable implants.Superhydrophobic coatings show excellent performance in terms of both corrosion resistance and inhibition of bacterial adhesion and growth.In this work,a hydroxyapatite(HA)/palmitic acid(PA)superhydrophobic composite coating was fabricated on the Mg alloy by the hydrothermal technique and immersion treatment.The HA/PA composite coating showed superhydrophobicity with a contact angle of 153°and a sliding angle of 2°.The coated Mg alloy exhibited excellent corrosion resistance in the simulated body fluid,with high polarization resistance(77.10 kΩ·cm^(2))and low corrosion current density((0.491±0.015)μA·cm^(-2)).Meanwhile,the antibacterial efficiency of the composite coating was over 98% against E.coli and S.aureus in different periods.The results indicate that the construction of such superhydrophobic composite coating(HA/PA)on the Mg alloy can greatly improve the corrosion resistance of Mg alloy implants within the human body and avoid bacterial infection during the initial stages of implantation.
基金supported by thc National Natural Science Foundation of China(Nos.52075246,51671105,51705244,and U1937206)the Natural Science Foundlation of Jiangsu Province(No.BK20170790)+2 种基金the Project Funded by China Postdoc-toral Science Foundation(No.2019M661826)Opcn Fund of Key Laboratory of lcing and Anti/Deicing(No.IADL20190202)the Projcct Funded by the Priority Academic Program Development of Jiangsu Highcr Education Institutions,and the NUAA Innovation Program for Graduate Education(No.kfjj20190617).
文摘Superhydrophobic coatings with high flexibility and mechanical durability can well address many practical application problems.To this end,we proposed and fabricated a kind of bio-based superhydrophobic(multi-walled carbon nanotubes)CNT@PU(polyurethane)coatings.It was demonstrated that the CNT@PU coatings with 64%soft segment content possessed the preferable bonding strength(5B)with metal substrates.The multi-walled carbon nanotubes,as additive materials,were used to construct the microscopic structures of the coating surfaces,which made polyurethane surface superhydrophobic(water contact angle being 156.9°,and water sliding angle being 4.3°).Furthermore,the high bonding strength between CNT and coating matrix led to robust mechanical durability of supertiydrophobic CNT@PU coatings,and the coatings remained superhydrophobicity after 10 cycles of abrasion under 100 g load pressure.Also,the superhydrophobic coatings could well resist 5 cycles of tape-peeling action,and presented outstanding flexibility.The supernydrophobic CNT@PU coatings with high flexibility and mechanical durability could be applied to various substrates suggesting their big potential in future real-world application.
基金L.Z.and C.L.contributed equally to this work.This work was supported by the Natural Science Foundation of China(No.51903001)Anhui Province International Science and Technology Cooperation Program(No.1804b06020360)+2 种基金Anhui Province International Cooperation Research Center of Textile Structure Composites(No.2021ACTC07)Research Funds of Anhui Polytechnic University(No.Xjky2020041)S.C.T.acknowledges the financial support from MOE AcRF2(R-284-000-217-112).
文摘Durable electromagnetic interference(EMI)shielding is highly desired,as electromagnetic pollution is a great concern for electronics’stable performance and human health.Although a superhydrophobic surface can extend the service lifespan of EMI shielding materials,degradation of its protection capability and insufficient self-healing are troublesome issues due to unavoidable physical/chemical damages under long-term application conditions.Here,we report,for the first time,an instantaneously self-healing approach via microwave heating to achieve durable shielding performance.First,a hydrophobic 1H,1H,2H,2H-perfluorooctyltriethoxysilane(POTS)layer was coated on a polypyrrole(PPy)-modified fabric(PPy@POTS),enabling protection against the invasion of water,salt solution,and corrosive acidic and basic solutions.Moreover,after being damaged,the POTS layer can,for the first time,be instantaneously self-healed via microwave heating for a very short time,i.e.,4 s,benefiting from the intense thermal energy generated by PPy under electromagnetic wave radiation.This self-healing ability is also repeatable even after intentionally severe plasma etching,which highlights the great potential to achieve robust and durable EMI shielding applications.Significantly,this approach can be extended to other EMI shielding materials where heat is a triggering stimulus for healing thin protection layers.We envision that this work could provide insights into fabricating EMI shielding materials with durable performance for portable and wearable devices,as well as for human health care.
基金the National Natural Science Foundation of China(52175207)the National Science and Technology Fund Project of China(2020-JCJQ-JJ-378).
文摘In this study,micro/nanostructures are fabricated on the surface of 3Cr13 stainless steel via laser etching,and a superhydrophobic coating with silver nanoparticles(AgNPs)is prepared by utilizing the reduction–adsorption properties of polydopamine(PDA).We investigate the effect of soaking time from the“one-step method”on the reduction of nano-Ag,surface wettability,and antibacterial properties.Scanning electron microscopy is performed to analyze the distribution of nano-Ag on the surface,whereas X-ray energy dispersive spectroscopy and X-ray photoelectron spectroscopy are used to analyze the crystal structures and chemical compositions of different surfaces.Samples deposited with PDA on their surface are soaked in a 1H,1H,2H,2H-perfluorodecyltriethoxysilane water–alcohol solution containing AgNO3 for 3 h.Subsequently,a“one-step method”is used to prepare low-adhesion superhydrophobic surfaces containing AgNPs.As immersion progresses,more AgNPs are deposited onto the surface.Compared with the polished surface,the samples prepared via the“one-step method”show significant antibacterial properties against both gram-negative Escherichia coli and gram-positive Staphylococcus aureus.The antibacterial properties of the surface improve as immersion progresses.
基金the project“Synthesis and Application of Superhydrophobic Self-cleaning Materials for Electric Engineering”(No.6111901321)Overseas Expertise Introduction Project(111 project)for Discipline Innovation of China(No.B18038)the State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)Open Foundation(No.SYSJJ2021-02).
文摘Biomimetic superhydrophobic(SH)coatings have emerged as a promising alternative to traditional room temperature vulcanizing(RTV)silicone rubber coatings for improving the flashover strength of insulators.However,organic contamination occurs in outdoor applications and thus a superamphiphobic(SAP)surface is more desirable but not yet reported for improving flashover performance.Herein,we developed a novel anti-flashover technique by fabricating robust SAP coating with unique gradient and micro-nanoscale hierarchical architecture.The SAP coating was fabricated by sequentially spray-depositing a resin-based primer and a silica-based topcoat on substrates(i.e.,glass slides and insulators).The primer not only functions as an adhesive offering strong adhesion to the substrate but also offers a micromastoid-like structure facilitating the subsequent formation of hierarchical micro-nanostructure.The appropriate spraying pressure leads to a diffusion of the fluorocarbon-modified silica nanoparticles into the primer to form a unique gradient structure,by analogy to inserting bullets into a wood.These features render the SAP coating excellent robustness with strong abrasive resistance,excellent ultraviolet(UV)resistance,and excellent chemical and thermal stability.Pollution flashover property of the SAP coating was explored and compared with that of SH and RTV specimens,from which a novel organic-contamination model to evaluate the flashover performance was proposed.The coated SAP glass insulator demonstrated 42.9%pollution flashover voltage improvement than RTV-coated insulator.These stated unique features reveal the convincing potential of the present SAP coatings to be applied for not only outdoor transmission line insulators for antiflashover but also other fields for self-cleaning,anti-fouling,and anti-icing.
基金supported by the National Natural Science Foundation of China (No. 51571134)the Scientific Research Foundation of Shandong University of Science and Technology (SDUST) for Recruited Talents (No. 2013RCJJ006)SDUST Research Fund (No. 2014TDJH104)
文摘A micro-arc oxidation（MAO）/zinc stearate（ZnSA） composite coating was fabricated via MAO processing and subsequent sealing with electrodeposition of a superhydrophobic ZnSA. The surface morphologies,chemical composition and corrosion resistance of the coatings were investigated using field-emission scanning electron microscopy, Fourier transform infrared, X-ray diffraction and electrochemical and hydrogen evolution measurements. Results indicated that the MAO coating was efficiently sealed by the following superhydrophobic ZnSA coating. The MAO/ZnSA composite coating significantly enhanced the corrosion resistance of Mg alloy Mg-4 Li-1 Ca due to its superhydrophobic function. Additionally, corrosion mechanism was suggested and discussed for the composite coating.
文摘A low-cost method was used to fabricate superhydrophobic coatings on a macroscopic model ship and the drag-reducing effect was investigated at both low and high speed. Hierarchical structures of the superhydrophobic copper coatings were characterized by means of scanning electron microscopy（SEM） and X-ray diffraction（XRD）. Drag coefficient tests on surfaces with different wettability（superhydrophilic, hydrophilic, hydrophobic and superhy- drophobic surfaces） showed that the as-prepared superhydrophobic surface exhibited a high remarkable drag reduction of 81% at a low speed of 1 mm/s. In the drag-reducing tests with model ship, the superhydrophobic coatings also exhibited around 16% drag reduction at a velocity of 0.3 m/s.
