The traditional single material with two-dimensional （2D） biomimetic moth-eye structures is limited by its narrowband antireflection and single functional capability. To overcome these disadvantages, we exploited we...The traditional single material with two-dimensional （2D） biomimetic moth-eye structures is limited by its narrowband antireflection and single functional capability. To overcome these disadvantages, we exploited wet etching and hydrothermal synthesis coupled with chemical oxidation for fabricating a three- dimensional （3D） biomimetic moth-eye coating with ternary materials （polypyrrole nanoparticles, TiO2 nanorods, and Si micropyramids, i.e., PPy/TiOa/Si-p）. This coating reduced the reflectivity to 〈4% at wavelengths ranging from 200 to 2,300 nm and exhibited remarkable superhydrophilidty with a low water contact angle of 1.8°. Moreover, the composite coating had double p-n heterojunctions, allowing the high-efficiency separation of photogenerated carriers. The photo- current density of PPy/TiO2/Si-p was more than three times higher than that of TiO2/Si-p at a positive potential of 1.5 V. The proposed method provides a means to enhance solar energy conversion.展开更多
The changes of the wettability of the solid surfaces have attracted massive attention due to their important practical implications in numerous fields. As a new subject, the research on the wettability under the diffe...The changes of the wettability of the solid surfaces have attracted massive attention due to their important practical implications in numerous fields. As a new subject, the research on the wettability under the different environments is still in its early stage. So the fundamental research must be performed for the practical applications under different environments. However, it is seldom that the comprehensive wettability of a surface in air, in water and in oil has been reported. In this paper, the authors investigated the wettability of the stainless steel mesh coated with polyurethane in the above three different environments. The surface of the uncoated mesh was found to be hydrophobic in air, but the surface of the coated mesh was superhydrophilic in air. More interestingly, the surfaces of the coated meshes were superoleophilic in water and superhydrophobic in oil. Due to the coated meshes with these wettabilities were fabricated via a facile two-step method, the presented method may be adopted for large-scale industrial production, in various fields, such as icing prevention or the oil-field industry.展开更多
We present a facile one-step method to fabricate superhydrophobic Ag surface by electrodeposition without using any low surface energy reagent. The water contact angle of the prepared surface is 167.1° and the sl...We present a facile one-step method to fabricate superhydrophobic Ag surface by electrodeposition without using any low surface energy reagent. The water contact angle of the prepared surface is 167.1° and the sliding angle is only 0.5° after heat treatment. It is demonstrated by the field emission scanning electron microscopy(FESEM),X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) analyses that the dendrites of rough micro-nanostructure combined with the spontaneously adsorbed hydrocarbon make the surface exhibit superhydrophobicity.However, the superhydrophobic Ag surface becomes superhydrophilic when the surface is irradiated by UV light for several hours. It recovers superhydrophobicity after further heat treatment and can successfully implement the reversible wettability transition between superhydrophobicity and superhydrophilicity for several cycles.展开更多
Spider-capture-silk(SCS)can directionally capture and transport water from humid air relying on the unique geometrical structure.Although there have been adequate reports on the fabrication of artificial SCSs from pet...Spider-capture-silk(SCS)can directionally capture and transport water from humid air relying on the unique geometrical structure.Although there have been adequate reports on the fabrication of artificial SCSs from petroleum-based materials,it remains a big challenge to innovate bio-based SCS mimicking fibers with high-performance fog collection ability and efficiency simultaneously.Herein,we report an eco-friendly and economical fiber system for water collection by coating gelatin on degummed silk.Compared to the previously reported fibers with the best fog collection ability(~13.10μL),Gelatin on silk fiber 10(GSF10)can collect larger water droplet(~16.70μL in 330 s)with~98%less mass.Meanwhile,the water collection efficiency of GSF10 demonstrates~72%and~48%enhancement to the existing best water collection polymer coated SCS fibers and spidroin eMaSp2 coated degummed silk respectively in terms of volume-to-TCL(vapor-liquid-solid three-phase contact line)index.The simultaneous function of superhydro-philicity,surface energy gradient,and~65%water-induced volume swelling of the gelatin knots are the key factors in advancing the water collection performance.Abundant availability of feedstocks and~75%improved space utiliza-tion guarantee the scalability and practical application of such bio-based fiber.展开更多
Inspired by the remarkable surface wetting behavior of natural organisms,artificially designed superwettable systems have attracted significant attention from multidisciplinary scientists over the past two decades.Sta...Inspired by the remarkable surface wetting behavior of natural organisms,artificially designed superwettable systems have attracted significant attention from multidisciplinary scientists over the past two decades.Starch is an eco-friendly,nontoxic,and low-cost natural polymer that serves as an alternative to nonbiodegradable and/or bioincompatible synthetic polymers in these systems.This review explores the unique contributions of starch to superwettable systems from design principles to emerging applications.First,the fundamental theories and design principles underlying starch-involved superwettable systems are introduced.The specific design principles of these systems are comprehensively discussed from the aspects of intrinsic properties(e.g.,hydrophilicity,film-forming properties,adhesiveness,and thermal decomposition),dimensionality(e.g.,colloidal systems,zero-dimensional granules/particles,one-dimensional fibers,two-dimensional films/fibrous membranes/coatings,and three-dimensional fillers/porous materials/food textures),and biotransformation.It also provides an overview of their applications in functio nal biomaterials,oral delivery systems,emulsion polymerizatio n,packaging technology,food taste modulation,and water treatment,with particular emphasis on intelligent systems.Each section summarizes recent advancements,highlighting the chemical and structural features.Finally,the review considers prospects for these superwettable systems,focusing on underutilized starch attributes and technical challenges.展开更多
The conversion of urea-containing wastewater into clean hydrogen energy has gained increasing attention.However,challenges remain,particularly with sluggish catalytic kinetics and limited long-term stability of urea o...The conversion of urea-containing wastewater into clean hydrogen energy has gained increasing attention.However,challenges remain,particularly with sluggish catalytic kinetics and limited long-term stability of urea oxidation reaction(UOR).Herein,we report the loosely porous CoOOH nano-architecture(CoOOH LPNAs)with hydrophilic surface and abundant oxygen vacancies(Ov)on carbon fiber paper(CFP)by electrochemical reconstruction of the CoP nanoneedles precursor.The resulting three-dimensional electrode exhibited an impressively low potential of 1.38 V at 1000 mA·cm^(−2) and excellent durability for UOR.Furthermore,when tested in an anion exchange membrane(AEM)electrolyzer,it required only 1.53 V at 1000 mA·cm^(−2) for industrial urea-assisted water splitting and operated stably for 100 h without degrada-tion.Experimental and theoretical investigations revealed that rich oxygen vacancies effectively modulate the electronic structure of the CoOOH while creating unique Co3-triangle sites with Co atoms close together.As a result,the adsorption and desorption processes of reactants and intermediates in UOR could be finely tuned,thereby significantly reducing ther-modynamic barriers.Additionally,the superhydrophilic self-supported nanoarray structure facilitated rapid gas bubble release,improving the overall efficiency of the reaction and preventing potential catalyst detachment caused by bubble accumulation,thereby improving both catalytic activity and stability at high current densities.展开更多
Utilizing superwettability micro/nanostructures to enhance the condensation heat transfer(CHT)performance of engineering materials has attracted great interest due to its values in basic research and technological inn...Utilizing superwettability micro/nanostructures to enhance the condensation heat transfer(CHT)performance of engineering materials has attracted great interest due to its values in basic research and technological innovations.Currently,exploring facile micro/nanofabrication approaches to create high-efficiency CHT surfaces has been one of research hotspots.In this work,we propose and demonstrate a type of new superwettability hybrid surface for high-efficiency CHT,which consists of superhydrophobic nanoneedle arrays and triangularly-patterned superhydrophilic microdots(SMDs).Such hybrid surface can be fabricated by the facile growth of densely-packed ZnO nanoneedles on the Zn-electroplated copper surface followed by fluorosilane modification and mask-assisted photodegradation.Through regulating the diameters and interspaces of SMDs,we obtain the optimized triangularly-patterned hybrid surface,which shows 42.7%higher CHT coefficient than the squarely-patterned hybrid surface and 58.5%higher CHT coefficient than the superhydrophobic surface.The key of such hybrid surface design is to considerably increase CHT coefficient brought about by SMD-triggered drop sweeping at the cost of slightly reducing heat transfer area of superhydrophobic functional zone for drop jumping.Such new strategy helps develop advanced CHT surfaces for high-efficiency electronic cooling and energy utilization.展开更多
Tackling the problem of poor conductivity and catalytic stability of pristine metal-organic frameworks(MOFs) is crucial to improve their oxygen evolution reaction(OER) performance.Herein,we introduce a novel strategy ...Tackling the problem of poor conductivity and catalytic stability of pristine metal-organic frameworks(MOFs) is crucial to improve their oxygen evolution reaction(OER) performance.Herein,we introduce a novel strategy of dysprosium(Dy) doping,using the unique 4f orbitals of this rare earth element to enhance electrocatalytic activity of MOFs.Our method involves constructing Dy-doped Ni-MOF(Dy@Ni-MOF) nanoneedles on carbon cloth via a Dy-induced valence electronic perturbation approach.Experiments and density functional theory(DFT) calculations reveal that Dy doping can effectively modify the electronic structure of the Ni active centers and foster a strong electronic interaction between Ni and Dy.The resulting benefits include a reduced work function and a closer proximity of the d-band center to the Fermi level,which is conducive to improving electrical conductivity and promoting the adsorption of oxygen-containing intermediates.Furthermore,the Dy@Ni-MOF achieves superhydrophilicity,ensuring effective electrolyte contact and thus accelerating reaction kinetics,Ex-situ and in-situ analysis results manifest Dy_(2)O_(3)/NiOOH as the actual active species.Therefore,Dy@Ni-MOF shows impressive OER performance,significantly surpassing Ni-MOF.Besides,the overall water splitting device with Dy@NiMOF as an anode delivers a low cell voltage of 1.51 V at 10 mA cm^(-2) and demonstrates long-term stability for 100 h,positioning it as a promising substitute for precious metal catalysts.展开更多
In the present work,transparent and anti-fogging AlPO_(4)-5 films were prepared on glass substrates using a novel developed process.The process entails a simple in-situ sol–gel followed by vapor phase transport.The i...In the present work,transparent and anti-fogging AlPO_(4)-5 films were prepared on glass substrates using a novel developed process.The process entails a simple in-situ sol–gel followed by vapor phase transport.The in-situ sol–gel process was implemented by coating the precursor sols for the synthesis of AlPO4-5 on the glass substrates successively using the spin-coating method.The films and powders scribed from the films were characterized by X-Ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),scanning electron microscope(SEM),atomic force microscope(AFM),X-ray photoelectron spectroscopy and transmission electron microscope(TEM).The unique films were composed of oblique oriented nanoflake AlPO_(4)-5 crystals with the thickness of about 20 nm.The formation of nano-flake crystals can be ascribed to the high concentration of the precursors,resulting in the formation of a supersaturation system.The obtained films showed high antifogging performance due to the superhydrophilicity with a water contact angle of lower than 1.0°.The silicone oil contact angle was also low about 8.2°.In addition,heteroatom-substituted AlPO_(4)-5 films showing different colors can be obtained easily by simply adding transition metal ions in the phosphate acid solution during the preparation that can extend the application of the method for different coating demand.展开更多
A transparent phase-pure anatase TiO_(2)nanofilm was prepared through magnetron sputtering method,and a subsequent annealing treatment awarded it the superhydrophilic characteristic.To make clear the mechanism of the ...A transparent phase-pure anatase TiO_(2)nanofilm was prepared through magnetron sputtering method,and a subsequent annealing treatment awarded it the superhydrophilic characteristic.To make clear the mechanism of the heat-induced superhydrophilicity,the chemical composition and surface morphology of the film were investigated in detail and compared before and after the annealing treatment mainly by field emission scanning electron microscopy(FESEM),X-ray diffraction method(XRD),Raman spectroscopy,and X-ray photoelectron spectroscope(XPS).The results suggest that the probable mechanism is in accordance with the UV-induced mechanism,where the heat-induced surface oxygen vacancies and hydroxyl radicals play important roles for achieving the superhydrophilicity.展开更多
Amplifying the intrinsic wettability of substrate material by changing the solid/liquid contact area is considered to be the main mechanism for controlling the wettability of rough or structured surfaces.Through theor...Amplifying the intrinsic wettability of substrate material by changing the solid/liquid contact area is considered to be the main mechanism for controlling the wettability of rough or structured surfaces.Through theoretical analysis and experimental exploration,we have found that in addition to this wettability structure amplification effect,the surface structure also simultaneously controls surface wettability by regulating the wetting state via changing the threshold Young angles of the Cassie-Baxter and Wenzel wetting regions.This wetting state regulation effect provides us with an alternative strategy to overcome the inherent limitation in surface chemistry by tailoring surface structure.The wetting state regulation effect created by multi-scale hierarchical structures is quite significant and plays is a crucial role in promoting the superhydrophobicity,superhydrophilicity and the transition between these two extreme wetting properties,as well as stabilizing the Cassie-Baxter superhydrophobic state on the fabricated lotus-like hierarchically structured Cu surface and the natural lotus leaf.展开更多
Superhydrophilic–superhydrophobic patterned surfaces constitute a branch of surface chemistry involving the two extreme states of superhydrophilicity and superhydrophobicity combined on the same surface in precise pa...Superhydrophilic–superhydrophobic patterned surfaces constitute a branch of surface chemistry involving the two extreme states of superhydrophilicity and superhydrophobicity combined on the same surface in precise patterns.Such surfaces have many advantages,including controllable wettability,enrichment ability,accessibility,and the ability to manipulate and pattern water droplets,and they offer new functionalities and possibilities for a wide variety of emerging applications,such as microarrays,biomedical assays,microfluidics,and environmental protection.This review presents the basic theory,simplified fabrication,and emerging applications of superhydrophilic–superhydrophobic patterned surfaces.First,the fundamental theories of wettability that explain the spreading of a droplet on a solid surface are described.Then,the fabrication methods for preparing superhydrophilic–superhydrophobic patterned surfaces are introduced,and the emerging applications of such surfaces that are currently being explored are highlighted.Finally,the remaining challenges of constructing such surfaces and future applications that would benefit from their use are discussed.展开更多
Oil–water mixing has brought many problems to a society, and it is of great significance to develop a simple, convenient, efficient, and durable separation material to solve the problem of oil–water mixing. In this ...Oil–water mixing has brought many problems to a society, and it is of great significance to develop a simple, convenient, efficient, and durable separation material to solve the problem of oil–water mixing. In this paper, modified cottons were successfully prepared using polydopamine as the in situ mineralization site of TiO_(2) nanoparticles combined with synergistic crosslinking with KH550. A large number of hydrophilic groups endowed the cotton with superhydrophilic ability, which greatly shortened its water spreading time. The prepared modified cotton could be successfully separated from oil and water, and still had a separation efficiency of 99.999% after 50 cycles. In addition, after 24 h immersion in 1 M HCl, NaOH, and NaCl solutions and 50 abrasion experiments, the modified cotton showed excellent oil–water separation ability, and the separation efficiency was above 99.990%. Successfully provided a simple preparation method to prepare high-efficiency and clean cottons for oil–water separation.展开更多
Nanocrystalline Cu film with a mirror surface finishing is prepared by the electric brush-plating technique. The as- prepared Cu film exhibits a superhydrophilic behavior with an apparent water contact angle smaller t...Nanocrystalline Cu film with a mirror surface finishing is prepared by the electric brush-plating technique. The as- prepared Cu film exhibits a superhydrophilic behavior with an apparent water contact angle smaller than 10°. A subsequent increase in the water contact angle and a final wetting transition from inherent hydrophilicity with water contact angle smaller than 90° to apparent hydrophobicity with water contact angle larger than 90° are observed when the Cu film is subjected to natural aging. Analysis based on the measurement of hardness with nanoindentation and the theory of the bond-order-length-strength correlation reveals that this wetting variation on the Cu film is attributed to the relaxation of residual stress generated during brush-plating deposition and a surface hydrophobization role associated with the broken bond polarization induced by surface nanostructure.展开更多
Developing cost-effective and facile methods to synthesize efficient and stable electrocatalysts for large-scale water splitting is highly desirable but remains a significant challenge.In this study,a facile ambient t...Developing cost-effective and facile methods to synthesize efficient and stable electrocatalysts for large-scale water splitting is highly desirable but remains a significant challenge.In this study,a facile ambient temperature synthesis of hierarchical nickel-iron(oxy)hydroxides nanosheets on iron foam(FF-FN)with both superhydrophilicity and superaerophobicity is reported.Specifically,the as-fabricated FF-FN electrode demonstrates extraordinary oxygen evolution reaction(OER)activity with an ultralow overpotential of 195 mV at 10 mA cm^(-2)and a small Tafel slope of 34 mV dec^(-1)in alkaline media.Further theoretical investigation indicates that the involved lattice oxygen in nickel-iron-based-oxyhydroxide during electrochemical self-reconstruction can significantly reduce the OER reaction overpotential via the dominated lattice oxygen mechanism.The rechargeable Zn-air battery assembled by directly using the as-prepared FF-FN as cathode displays remarkable cycling performance.It is believed that this work affords an economical approach to steer commercial Fe foam into robust electrocatalysts for sustainable energy conversion and storage systems.展开更多
Fog harvesting has been considered as a promising method for solving water crisis in underdeveloped regions.To mimic and optimize the alleged natural fog harvesting ability of the stenocara beetle,hybrid superhydropho...Fog harvesting has been considered as a promising method for solving water crisis in underdeveloped regions.To mimic and optimize the alleged natural fog harvesting ability of the stenocara beetle,hybrid superhydrophobic(hydrophobic,superhydrophilic)/hydrophilic patterns are processed on stainless steel via picosecond laser direct writing.Basically,after laser processing,the surfaces of stainless steel change from hydrophilic to superhydrophilic.Then,after chemical and heat treatment,the superhydrophilic surfaces become superhydrophobic with ultra-low adhesion,and superhydrophobic(hydrophobic)with ultra-high adhesion,respectively.This work systematically examines the fog harvesting ability of picosecond laser treated surfaces(LTS),pristine surfaces(PS),laser and chemical treated surfaces(LCTS),laser and heat-treated surfaces(LHTS).Compared with the PS,the as-prepared surfaces enhanced the fog harvesting efficiency by 50%.This work provides a fast and simple method to fog collectors,which offer a great opportunity to develop water harvesters for real world applications.展开更多
Highly hydrophilic materials enable rapid water delivery and salt redissolution in solar-driven seawater desalination. However, the lack of independent floatability inhibits heat localization at the air/water interfac...Highly hydrophilic materials enable rapid water delivery and salt redissolution in solar-driven seawater desalination. However, the lack of independent floatability inhibits heat localization at the air/water interface. In nature, seaweeds with internal gas microvesicles can float near the sea surface to ensure photosynthesis. Here, we have developed a seaweed-inspired, independently floatable, but superhydrophilic (SIFS) solar evaporator. It needs no extra floatation support and can simultaneously achieve continuous water pumping and heat concentration. The evaporator resists salt accumulation, oil pollution, microbial corrosion, and protein adsorption. Densely packed hollow glass microbeads promote intrinsic floatability and heat insulation. Superhydrophilic zwitterionic sulfobetaine hydrogel provides a continuous water supply, redissolves the deposited salt, and endows the SIFS evaporator with excellent anti-fouling properties. With its unprecedented anti-contamination ability, this SIFS evaporator is expected to open a new avenue for designing floatable superhydrophilic materials and solving real-world issues of solar steam generation in complex environmental conditions.展开更多
Membrane filtration is one of the effective approaches to harvest microalgae for industrial biofuel production.However,during the filtration process,microalgae cells and extracellular organic matter(EOM)will deposit o...Membrane filtration is one of the effective approaches to harvest microalgae for industrial biofuel production.However,during the filtration process,microalgae cells and extracellular organic matter(EOM)will deposit on the membrane surface leading to reversible membrane fouling that can be removed by physical methods.When hydrophobic EOM is adsorbed on the membrane surface or inside pores,it will build up a gel layer,causing irreversible membrane fouling.Irreversible fouling can only be removed using chemical methods that will decrease membrane lifespan and increase operational costs.Here,we introduce a versatile superhydrophilic membrane with photo-Fenton self-cleaning property,which can prevent the reversible fouling and remove the irreversible fouling.Tannic acid(TA)and 3-aminopropyltriethoxysilane(APTES)were co-deposited on the polyvinylidene fluoride(PVDF)membrane via Schiff base and Michael addition reactions,andβ-FeOOH nanorods were inlaid on the membrane surface by in situ mineralization.The water contact angle of the modified membrane is reduced from 120°to 0°Under 60 min visible light,the hydroxyl radical(·OH)generated by the photo-Fenton reaction degraded the irreversible fouling that blocked membrane pores.The irreversible fouling rates of modified membrane was reduced from 39.57%to 3.26%,compared with the original membrane.Microalgae harvesting results illustrated that the membrane has a high flux recovery rate(FRR)of 98.2%,showed excellent passive antifouling and active antifouling performance.We believe this work will spark a novel platform for optimizing energy-efficient microalgae harvesting separation membrane modules.In addition,this method of anti-fouling filtration for microorganisms can be extended to the industrial production of various bioenergy sources and will have very promising practical applications.展开更多
基金This work was supported by the National Natural Science Foundation of China （Nos. 21401079, 21501069, and 21671081）, Fundamental Research Funds for the Central Universities （No. JUSRP51626B）, and Natural Science Foundation of Jiangsu Province （Nos. BK20140158 and BK20161128）.
文摘The traditional single material with two-dimensional （2D） biomimetic moth-eye structures is limited by its narrowband antireflection and single functional capability. To overcome these disadvantages, we exploited wet etching and hydrothermal synthesis coupled with chemical oxidation for fabricating a three- dimensional （3D） biomimetic moth-eye coating with ternary materials （polypyrrole nanoparticles, TiO2 nanorods, and Si micropyramids, i.e., PPy/TiOa/Si-p）. This coating reduced the reflectivity to 〈4% at wavelengths ranging from 200 to 2,300 nm and exhibited remarkable superhydrophilidty with a low water contact angle of 1.8°. Moreover, the composite coating had double p-n heterojunctions, allowing the high-efficiency separation of photogenerated carriers. The photo- current density of PPy/TiO2/Si-p was more than three times higher than that of TiO2/Si-p at a positive potential of 1.5 V. The proposed method provides a means to enhance solar energy conversion.
基金supported by the National Natural Science Foundation of China(Grant Nos.51475353,51375361&51475352)the Tribology Science Fund of the State Key Laboratory of Tribology(Grant No.SKLTKF14A02)+1 种基金the Natural Science Basic Research Program of Shaanxi Province(Grant No.2016JM5004)the Key Laboratory of the Shaanxi Provincial Department of Education(Grant No.16JS057)
文摘The changes of the wettability of the solid surfaces have attracted massive attention due to their important practical implications in numerous fields. As a new subject, the research on the wettability under the different environments is still in its early stage. So the fundamental research must be performed for the practical applications under different environments. However, it is seldom that the comprehensive wettability of a surface in air, in water and in oil has been reported. In this paper, the authors investigated the wettability of the stainless steel mesh coated with polyurethane in the above three different environments. The surface of the uncoated mesh was found to be hydrophobic in air, but the surface of the coated mesh was superhydrophilic in air. More interestingly, the surfaces of the coated meshes were superoleophilic in water and superhydrophobic in oil. Due to the coated meshes with these wettabilities were fabricated via a facile two-step method, the presented method may be adopted for large-scale industrial production, in various fields, such as icing prevention or the oil-field industry.
基金supported by the National Natural Science Foundation of China(51263018)the International S&T Cooperation Program of China(2012DFA51200)
文摘We present a facile one-step method to fabricate superhydrophobic Ag surface by electrodeposition without using any low surface energy reagent. The water contact angle of the prepared surface is 167.1° and the sliding angle is only 0.5° after heat treatment. It is demonstrated by the field emission scanning electron microscopy(FESEM),X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) analyses that the dendrites of rough micro-nanostructure combined with the spontaneously adsorbed hydrocarbon make the surface exhibit superhydrophobicity.However, the superhydrophobic Ag surface becomes superhydrophilic when the surface is irradiated by UV light for several hours. It recovers superhydrophobicity after further heat treatment and can successfully implement the reversible wettability transition between superhydrophobicity and superhydrophilicity for several cycles.
基金The National Natural Science Foundation of China(Nos.52073186,52073241)State Key Laboratory of Polymer Materials Engineering(sklpme2021-3-01)+2 种基金Funding of Engineering Characteristic Team,Sichuan University(2020SCUNG122)Hong Kong General Research Fund(15201719)the Guangdong Basic and Applied Basic Research Foundation,Shenzhen Joint Fund,Youth Fund Project 2019(2019A1515111207).
文摘Spider-capture-silk(SCS)can directionally capture and transport water from humid air relying on the unique geometrical structure.Although there have been adequate reports on the fabrication of artificial SCSs from petroleum-based materials,it remains a big challenge to innovate bio-based SCS mimicking fibers with high-performance fog collection ability and efficiency simultaneously.Herein,we report an eco-friendly and economical fiber system for water collection by coating gelatin on degummed silk.Compared to the previously reported fibers with the best fog collection ability(~13.10μL),Gelatin on silk fiber 10(GSF10)can collect larger water droplet(~16.70μL in 330 s)with~98%less mass.Meanwhile,the water collection efficiency of GSF10 demonstrates~72%and~48%enhancement to the existing best water collection polymer coated SCS fibers and spidroin eMaSp2 coated degummed silk respectively in terms of volume-to-TCL(vapor-liquid-solid three-phase contact line)index.The simultaneous function of superhydro-philicity,surface energy gradient,and~65%water-induced volume swelling of the gelatin knots are the key factors in advancing the water collection performance.Abundant availability of feedstocks and~75%improved space utiliza-tion guarantee the scalability and practical application of such bio-based fiber.
基金financially supported by the National Key Research and Development Program of China(2023YFD1600600 and 2021YFD1600105-03)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZB20240665)+1 种基金the Special Funding for Postdoctoral Research Projects in Zhejiang(ZJ2024044)the China Postdoctoral Science Foundation(2024M762848)。
文摘Inspired by the remarkable surface wetting behavior of natural organisms,artificially designed superwettable systems have attracted significant attention from multidisciplinary scientists over the past two decades.Starch is an eco-friendly,nontoxic,and low-cost natural polymer that serves as an alternative to nonbiodegradable and/or bioincompatible synthetic polymers in these systems.This review explores the unique contributions of starch to superwettable systems from design principles to emerging applications.First,the fundamental theories and design principles underlying starch-involved superwettable systems are introduced.The specific design principles of these systems are comprehensively discussed from the aspects of intrinsic properties(e.g.,hydrophilicity,film-forming properties,adhesiveness,and thermal decomposition),dimensionality(e.g.,colloidal systems,zero-dimensional granules/particles,one-dimensional fibers,two-dimensional films/fibrous membranes/coatings,and three-dimensional fillers/porous materials/food textures),and biotransformation.It also provides an overview of their applications in functio nal biomaterials,oral delivery systems,emulsion polymerizatio n,packaging technology,food taste modulation,and water treatment,with particular emphasis on intelligent systems.Each section summarizes recent advancements,highlighting the chemical and structural features.Finally,the review considers prospects for these superwettable systems,focusing on underutilized starch attributes and technical challenges.
基金supported by the Applied Basic Research Program of Yunnan Province(202101BE070001-032)Yunnan Major Scientific and Technological Projects(No.202202AG050001).
文摘The conversion of urea-containing wastewater into clean hydrogen energy has gained increasing attention.However,challenges remain,particularly with sluggish catalytic kinetics and limited long-term stability of urea oxidation reaction(UOR).Herein,we report the loosely porous CoOOH nano-architecture(CoOOH LPNAs)with hydrophilic surface and abundant oxygen vacancies(Ov)on carbon fiber paper(CFP)by electrochemical reconstruction of the CoP nanoneedles precursor.The resulting three-dimensional electrode exhibited an impressively low potential of 1.38 V at 1000 mA·cm^(−2) and excellent durability for UOR.Furthermore,when tested in an anion exchange membrane(AEM)electrolyzer,it required only 1.53 V at 1000 mA·cm^(−2) for industrial urea-assisted water splitting and operated stably for 100 h without degrada-tion.Experimental and theoretical investigations revealed that rich oxygen vacancies effectively modulate the electronic structure of the CoOOH while creating unique Co3-triangle sites with Co atoms close together.As a result,the adsorption and desorption processes of reactants and intermediates in UOR could be finely tuned,thereby significantly reducing ther-modynamic barriers.Additionally,the superhydrophilic self-supported nanoarray structure facilitated rapid gas bubble release,improving the overall efficiency of the reaction and preventing potential catalyst detachment caused by bubble accumulation,thereby improving both catalytic activity and stability at high current densities.
基金supported by National Natural Science Foundation of China(No.21573276)Natural Science Foundation of Jiangsu Province(No.BK20170007)Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB846).
文摘Utilizing superwettability micro/nanostructures to enhance the condensation heat transfer(CHT)performance of engineering materials has attracted great interest due to its values in basic research and technological innovations.Currently,exploring facile micro/nanofabrication approaches to create high-efficiency CHT surfaces has been one of research hotspots.In this work,we propose and demonstrate a type of new superwettability hybrid surface for high-efficiency CHT,which consists of superhydrophobic nanoneedle arrays and triangularly-patterned superhydrophilic microdots(SMDs).Such hybrid surface can be fabricated by the facile growth of densely-packed ZnO nanoneedles on the Zn-electroplated copper surface followed by fluorosilane modification and mask-assisted photodegradation.Through regulating the diameters and interspaces of SMDs,we obtain the optimized triangularly-patterned hybrid surface,which shows 42.7%higher CHT coefficient than the squarely-patterned hybrid surface and 58.5%higher CHT coefficient than the superhydrophobic surface.The key of such hybrid surface design is to considerably increase CHT coefficient brought about by SMD-triggered drop sweeping at the cost of slightly reducing heat transfer area of superhydrophobic functional zone for drop jumping.Such new strategy helps develop advanced CHT surfaces for high-efficiency electronic cooling and energy utilization.
基金supported by the National Natural Science Foundation of China(52363028,21965005)the Natural Science Foundation of Guangxi Province(2021GXNSFAA076001)the Guangxi Technology Base and Talent Subject(GUIKE AD18126001,GUIKE AD20297039)。
文摘Tackling the problem of poor conductivity and catalytic stability of pristine metal-organic frameworks(MOFs) is crucial to improve their oxygen evolution reaction(OER) performance.Herein,we introduce a novel strategy of dysprosium(Dy) doping,using the unique 4f orbitals of this rare earth element to enhance electrocatalytic activity of MOFs.Our method involves constructing Dy-doped Ni-MOF(Dy@Ni-MOF) nanoneedles on carbon cloth via a Dy-induced valence electronic perturbation approach.Experiments and density functional theory(DFT) calculations reveal that Dy doping can effectively modify the electronic structure of the Ni active centers and foster a strong electronic interaction between Ni and Dy.The resulting benefits include a reduced work function and a closer proximity of the d-band center to the Fermi level,which is conducive to improving electrical conductivity and promoting the adsorption of oxygen-containing intermediates.Furthermore,the Dy@Ni-MOF achieves superhydrophilicity,ensuring effective electrolyte contact and thus accelerating reaction kinetics,Ex-situ and in-situ analysis results manifest Dy_(2)O_(3)/NiOOH as the actual active species.Therefore,Dy@Ni-MOF shows impressive OER performance,significantly surpassing Ni-MOF.Besides,the overall water splitting device with Dy@NiMOF as an anode delivers a low cell voltage of 1.51 V at 10 mA cm^(-2) and demonstrates long-term stability for 100 h,positioning it as a promising substitute for precious metal catalysts.
基金financial support from the Key University Science Research Project of Jiangsu Province(16KJA430007)Opening Topic of Key Laboratory of Attapulgite Resources Utilization in Jiangsu Province(HPK201804)Opening Topic of National Local Joint Engineering Research Center for Deep Utilization of Mineral and Salt Resources(SF201804)。
文摘In the present work,transparent and anti-fogging AlPO_(4)-5 films were prepared on glass substrates using a novel developed process.The process entails a simple in-situ sol–gel followed by vapor phase transport.The in-situ sol–gel process was implemented by coating the precursor sols for the synthesis of AlPO4-5 on the glass substrates successively using the spin-coating method.The films and powders scribed from the films were characterized by X-Ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),scanning electron microscope(SEM),atomic force microscope(AFM),X-ray photoelectron spectroscopy and transmission electron microscope(TEM).The unique films were composed of oblique oriented nanoflake AlPO_(4)-5 crystals with the thickness of about 20 nm.The formation of nano-flake crystals can be ascribed to the high concentration of the precursors,resulting in the formation of a supersaturation system.The obtained films showed high antifogging performance due to the superhydrophilicity with a water contact angle of lower than 1.0°.The silicone oil contact angle was also low about 8.2°.In addition,heteroatom-substituted AlPO_(4)-5 films showing different colors can be obtained easily by simply adding transition metal ions in the phosphate acid solution during the preparation that can extend the application of the method for different coating demand.
基金National Nature Science Foundation of China(50705094)
文摘A transparent phase-pure anatase TiO_(2)nanofilm was prepared through magnetron sputtering method,and a subsequent annealing treatment awarded it the superhydrophilic characteristic.To make clear the mechanism of the heat-induced superhydrophilicity,the chemical composition and surface morphology of the film were investigated in detail and compared before and after the annealing treatment mainly by field emission scanning electron microscopy(FESEM),X-ray diffraction method(XRD),Raman spectroscopy,and X-ray photoelectron spectroscope(XPS).The results suggest that the probable mechanism is in accordance with the UV-induced mechanism,where the heat-induced surface oxygen vacancies and hydroxyl radicals play important roles for achieving the superhydrophilicity.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52105303 and 52025053)Natural Science Foundation of Jilin Province(No.20220101209JC)Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003).
文摘Amplifying the intrinsic wettability of substrate material by changing the solid/liquid contact area is considered to be the main mechanism for controlling the wettability of rough or structured surfaces.Through theoretical analysis and experimental exploration,we have found that in addition to this wettability structure amplification effect,the surface structure also simultaneously controls surface wettability by regulating the wetting state via changing the threshold Young angles of the Cassie-Baxter and Wenzel wetting regions.This wetting state regulation effect provides us with an alternative strategy to overcome the inherent limitation in surface chemistry by tailoring surface structure.The wetting state regulation effect created by multi-scale hierarchical structures is quite significant and plays is a crucial role in promoting the superhydrophobicity,superhydrophilicity and the transition between these two extreme wetting properties,as well as stabilizing the Cassie-Baxter superhydrophobic state on the fabricated lotus-like hierarchically structured Cu surface and the natural lotus leaf.
基金This work was supported by the Independent Innovation Fund of Tianjin University(Grant No.2022XJS-0003)the National Key Research and Development Program of China(Grant No.2019YFA0905804).
文摘Superhydrophilic–superhydrophobic patterned surfaces constitute a branch of surface chemistry involving the two extreme states of superhydrophilicity and superhydrophobicity combined on the same surface in precise patterns.Such surfaces have many advantages,including controllable wettability,enrichment ability,accessibility,and the ability to manipulate and pattern water droplets,and they offer new functionalities and possibilities for a wide variety of emerging applications,such as microarrays,biomedical assays,microfluidics,and environmental protection.This review presents the basic theory,simplified fabrication,and emerging applications of superhydrophilic–superhydrophobic patterned surfaces.First,the fundamental theories of wettability that explain the spreading of a droplet on a solid surface are described.Then,the fabrication methods for preparing superhydrophilic–superhydrophobic patterned surfaces are introduced,and the emerging applications of such surfaces that are currently being explored are highlighted.Finally,the remaining challenges of constructing such surfaces and future applications that would benefit from their use are discussed.
基金supported by the National Natural Science Foundation of China(no.51735013).
文摘Oil–water mixing has brought many problems to a society, and it is of great significance to develop a simple, convenient, efficient, and durable separation material to solve the problem of oil–water mixing. In this paper, modified cottons were successfully prepared using polydopamine as the in situ mineralization site of TiO_(2) nanoparticles combined with synergistic crosslinking with KH550. A large number of hydrophilic groups endowed the cotton with superhydrophilic ability, which greatly shortened its water spreading time. The prepared modified cotton could be successfully separated from oil and water, and still had a separation efficiency of 99.999% after 50 cycles. In addition, after 24 h immersion in 1 M HCl, NaOH, and NaCl solutions and 50 abrasion experiments, the modified cotton showed excellent oil–water separation ability, and the separation efficiency was above 99.990%. Successfully provided a simple preparation method to prepare high-efficiency and clean cottons for oil–water separation.
基金Project supported by the National Natural Science Foundations of China(Grant No.51371089)the Foundation of National Key Basic Research and Development Program of China(Grant No.2010CB 631001)
文摘Nanocrystalline Cu film with a mirror surface finishing is prepared by the electric brush-plating technique. The as- prepared Cu film exhibits a superhydrophilic behavior with an apparent water contact angle smaller than 10°. A subsequent increase in the water contact angle and a final wetting transition from inherent hydrophilicity with water contact angle smaller than 90° to apparent hydrophobicity with water contact angle larger than 90° are observed when the Cu film is subjected to natural aging. Analysis based on the measurement of hardness with nanoindentation and the theory of the bond-order-length-strength correlation reveals that this wetting variation on the Cu film is attributed to the relaxation of residual stress generated during brush-plating deposition and a surface hydrophobization role associated with the broken bond polarization induced by surface nanostructure.
基金sponsored by the Guangdong-Hong Kong-Macao Joint Laboratory(grant no.2019B121205001)Macao Science and Technology Development Fund(FDCT)for funding(project no.0098/2020/A2)+2 种基金the support of the National Natural Science Foundation of China(Grant No.52104309)Natural Science Foundation of Hubei Province(2021CFB011)“Macao Young Scholars Program,”China(AM2020004).
文摘Developing cost-effective and facile methods to synthesize efficient and stable electrocatalysts for large-scale water splitting is highly desirable but remains a significant challenge.In this study,a facile ambient temperature synthesis of hierarchical nickel-iron(oxy)hydroxides nanosheets on iron foam(FF-FN)with both superhydrophilicity and superaerophobicity is reported.Specifically,the as-fabricated FF-FN electrode demonstrates extraordinary oxygen evolution reaction(OER)activity with an ultralow overpotential of 195 mV at 10 mA cm^(-2)and a small Tafel slope of 34 mV dec^(-1)in alkaline media.Further theoretical investigation indicates that the involved lattice oxygen in nickel-iron-based-oxyhydroxide during electrochemical self-reconstruction can significantly reduce the OER reaction overpotential via the dominated lattice oxygen mechanism.The rechargeable Zn-air battery assembled by directly using the as-prepared FF-FN as cathode displays remarkable cycling performance.It is believed that this work affords an economical approach to steer commercial Fe foam into robust electrocatalysts for sustainable energy conversion and storage systems.
基金Project(52075302)supported by the National Natural Science Foundation of ChinaProject(ZR2021QE247)supported by the Shandong Provincial Natural Science Foundation,China+2 种基金Projects(ZR2018ZB0521,ZR2018ZA0401)supported by the Major Basic Research of Shandong Provincial Natural Science Foundation,ChinaProject(Kfkt2020-09)supported by the Open Research Fund of State Key Laboratory of High Performance Complex Manufacturing,Central South University,ChinaProject(52075302)supported by the Key Laboratory of High-efficiency and Clean Mechanical Manufacture(Shandong University),Ministry of Education,China。
文摘Fog harvesting has been considered as a promising method for solving water crisis in underdeveloped regions.To mimic and optimize the alleged natural fog harvesting ability of the stenocara beetle,hybrid superhydrophobic(hydrophobic,superhydrophilic)/hydrophilic patterns are processed on stainless steel via picosecond laser direct writing.Basically,after laser processing,the surfaces of stainless steel change from hydrophilic to superhydrophilic.Then,after chemical and heat treatment,the superhydrophilic surfaces become superhydrophobic with ultra-low adhesion,and superhydrophobic(hydrophobic)with ultra-high adhesion,respectively.This work systematically examines the fog harvesting ability of picosecond laser treated surfaces(LTS),pristine surfaces(PS),laser and chemical treated surfaces(LCTS),laser and heat-treated surfaces(LHTS).Compared with the PS,the as-prepared surfaces enhanced the fog harvesting efficiency by 50%.This work provides a fast and simple method to fog collectors,which offer a great opportunity to develop water harvesters for real world applications.
基金supported by the National Natural Science Foundation of China(21621004,21961132005,22078238,21908160,and 21805204)the Tianjin Natural Science Foundation(19JCQNJC05100 and 20JCQNJC00170)+1 种基金Young Elite Scientists Sponsorship Program by Tianjin(TJSQNTJ-2018-17)the China Postdoctoral Science Foundation(2019M651041).
文摘Highly hydrophilic materials enable rapid water delivery and salt redissolution in solar-driven seawater desalination. However, the lack of independent floatability inhibits heat localization at the air/water interface. In nature, seaweeds with internal gas microvesicles can float near the sea surface to ensure photosynthesis. Here, we have developed a seaweed-inspired, independently floatable, but superhydrophilic (SIFS) solar evaporator. It needs no extra floatation support and can simultaneously achieve continuous water pumping and heat concentration. The evaporator resists salt accumulation, oil pollution, microbial corrosion, and protein adsorption. Densely packed hollow glass microbeads promote intrinsic floatability and heat insulation. Superhydrophilic zwitterionic sulfobetaine hydrogel provides a continuous water supply, redissolves the deposited salt, and endows the SIFS evaporator with excellent anti-fouling properties. With its unprecedented anti-contamination ability, this SIFS evaporator is expected to open a new avenue for designing floatable superhydrophilic materials and solving real-world issues of solar steam generation in complex environmental conditions.
基金supported by the Fujian Provincial Science and Technology Cooperation Project(No.20210002)National Natural Science Foundation of China(No.31870994).
文摘Membrane filtration is one of the effective approaches to harvest microalgae for industrial biofuel production.However,during the filtration process,microalgae cells and extracellular organic matter(EOM)will deposit on the membrane surface leading to reversible membrane fouling that can be removed by physical methods.When hydrophobic EOM is adsorbed on the membrane surface or inside pores,it will build up a gel layer,causing irreversible membrane fouling.Irreversible fouling can only be removed using chemical methods that will decrease membrane lifespan and increase operational costs.Here,we introduce a versatile superhydrophilic membrane with photo-Fenton self-cleaning property,which can prevent the reversible fouling and remove the irreversible fouling.Tannic acid(TA)and 3-aminopropyltriethoxysilane(APTES)were co-deposited on the polyvinylidene fluoride(PVDF)membrane via Schiff base and Michael addition reactions,andβ-FeOOH nanorods were inlaid on the membrane surface by in situ mineralization.The water contact angle of the modified membrane is reduced from 120°to 0°Under 60 min visible light,the hydroxyl radical(·OH)generated by the photo-Fenton reaction degraded the irreversible fouling that blocked membrane pores.The irreversible fouling rates of modified membrane was reduced from 39.57%to 3.26%,compared with the original membrane.Microalgae harvesting results illustrated that the membrane has a high flux recovery rate(FRR)of 98.2%,showed excellent passive antifouling and active antifouling performance.We believe this work will spark a novel platform for optimizing energy-efficient microalgae harvesting separation membrane modules.In addition,this method of anti-fouling filtration for microorganisms can be extended to the industrial production of various bioenergy sources and will have very promising practical applications.
