The controllable transfer of droplets on the surface of objects has a wide application prospect in the fields of microfluidic devices,fog collection and so on.The Leidenfrost effect can be utilized to significantly re...The controllable transfer of droplets on the surface of objects has a wide application prospect in the fields of microfluidic devices,fog collection and so on.The Leidenfrost effect can be utilized to significantly reduce motion resistance.However,the use of 3D structures limits the widespread application of self-propulsion based on Leidenfrost droplets in microelectromechanical system.To manipulate Leidenfrost droplets,it is necessary to create 2D or quasi-2D geometries.In this study,femtosecond laser is applied to fabricate a surface with periodic hydrophobicity gradient(SPHG),enabling directional self-propulsion of Leidenfrost droplets.Flow field analysis within the Leidenfrost droplets reveals that the vapor layer between the droplets and the hot surface can be modulated by the SPHG,resulting in directional propulsion of the inner gas.The viscous force between the gas and liquid then drives the droplet to move.展开更多
Reduced graphene oxide(rGO)aerogels are emerging as very attractive scaffolds for high-performance electromagnetic wave absorption materials(EWAMs)due to their intrinsic conductive networks and intricate interior micr...Reduced graphene oxide(rGO)aerogels are emerging as very attractive scaffolds for high-performance electromagnetic wave absorption materials(EWAMs)due to their intrinsic conductive networks and intricate interior microstructure,as well as good compatibility with other electromagnetic(EM)components.Herein,we realized the decoration of rGO aerogel with Mo_(2)C nanoparticles by sequential hydrothermal assembly,freeze-drying,and high-temperature pyrolysis.Results show that Mo_(2)C nanoparticle loading can be easily controlled by the ammonium molybdate to glucose molar ratio.The hydrophobicity and thermal insulation of the rGO aerogel are effectively improved upon the introduction of Mo_(2)C nanoparticles,and more importantly,these nanoparticles regulate the EM properties of the rGO aerogel to a large extent.Although more Mo_(2)C nanoparticles may decrease the overall attenuation ability of the rGO aerogel,they bring much better impedance matching.At a molar ratio of 1:1,a desirable balance between attenuation ability and impedance matching is observed.In this context,the Mo_(2)C/r GO aerogel displays strong reflection loss and broad response bandwidth,even with a small applied thickness(1.7 mm)and low filler loading(9.0wt%).The positive effects of Mo_(2)C nanoparticles on multifunctional properties may render Mo_(2)C/r GO aerogels promising candidates for high-performance EWAMs under harsh conditions.展开更多
Although hydrophilic membranes are desired for reducing resistance to water permeation, hydrophilic surfaces are not used in the water-in-oil(W/O) membrane emulsification process because water spreads on the hydrophil...Although hydrophilic membranes are desired for reducing resistance to water permeation, hydrophilic surfaces are not used in the water-in-oil(W/O) membrane emulsification process because water spreads on the hydrophilic surface without forming droplets. Here, we report that a hydrophilic ceramic membrane can form a hydrophobic interface in diesel at a higher temperature;interestingly, the experiments show that the contact angle increases when the temperature rises. The hydrophilic membrane surface evolves into a hydrophobic interface, particularly near the boiling point of water, resulting in a water contact angle of 147.5° ± 1.2°. This work established a method for preparing W/O monodispersed emulsions by direct emulsification of hydrophilic ceramic membranes at a temperature close to the boiling point of water.Additionally, it made high flux of membrane emulsification of monodispersed W/O emulsions possible,which satisfied the industrial requirements of fluidized catalytic cracking in the petrochemical industry.展开更多
Developing metal-organic framework(MOF)materials with the moisture-resistant feature is highly desirable for CO_(2)capture from highly humid flue gas.In this work,a new core-shell MOF@MOF composite using Mg-MOF-74 wit...Developing metal-organic framework(MOF)materials with the moisture-resistant feature is highly desirable for CO_(2)capture from highly humid flue gas.In this work,a new core-shell MOF@MOF composite using Mg-MOF-74 with high CO_(2)capture capacity as a functional core and hydrophobic zeolitic imidazolate framework-8(ZIF-8)as a protective shell is fabricated by the epitaxial growth method.Experimental results show that the CO_(2)adsorption performance of the core-shell structured Mg-MOF-74@ZIF-8 composites from water-containing flue gas is enhanced along with their improved hydrophobicity.The dynamic breakthrough results show that the Mg-MOF-74@ZIF-8 with three assembled layers(Mg-MOF-74@ZIF-8-3)can capture 3.56 mmol-g^(-1)CO_(2)from wet CO_(2)/N_(2)(VCO_(2):V_(N_(2))=15:85)mixtures,which outperforms Mg-MOF-74(0.37 mmol·g^(-1))and most of the reported physisorbents.展开更多
The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR inv...The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR involves two half-reactions:the CO_(2) reduction half-reaction(CRHR)and the water oxidation half-reaction(WOHR).Generally,both half-reactions can be promoted by adjusting the wettability of catalysts.However,there is a contradiction in wettability requirements for the two half-reactions.Specifically,CRHR prefers a hydrophobic surface that can accumulate more CO_(2) molecules on the active sites,ensuring the appropriate ratio of gas-phase(CO_(2))to liquid-phase(H_(2)O)reactants.Conversely,the WOHR prefers a hydrophilic surface that can promote the departure of the gaseous product(O_(2))from the catalyst surface,preventing isolation between active sites and the reactant(H_(2)O).Here,we successfully reconciled the contradictory wettability requirements for the CRHR and WOHR by creating an alternately hydrophobic catalyst.This was achieved through a selectively hydrophobic modification method and a charge-transfer-control strategy.Consequently,the collaboratively promoted CRHR and WOHR led to a significantly enhanced OPCRR with a solar-to-fuel conversion efficiency of 0.186%.Notably,in ethanol production,the catalyst exhibited a 10.64-fold increase in generation rate(271.44μmol g^(-1)h~(-1))and a 4-fold increase in selectivity(55.77%)compared to the benchmark catalyst.This innovative approach holds great potential for application in universal overall reactions involving gas participation.展开更多
Silicone rubber (SIR) shows superior performance when used outdoors, but its surface can be transformed from inherently hydrophobic to hydrophilic by the adsorption of contaminants. Al(OH)(3), Al2O3, quartz powder and...Silicone rubber (SIR) shows superior performance when used outdoors, but its surface can be transformed from inherently hydrophobic to hydrophilic by the adsorption of contaminants. Al(OH)(3), Al2O3, quartz powder and active carbon were selected as authentic contaminants. Hydrophobicity of the surface was determined using contact angle measurement. The results indicate that the adsorbability of the contaminants can strongly affect the hydrophobicity of contaminated SIR surface. The increasing rate of contact angle of specimens contaminated by Al(OH)(3) was much faster than that by Al2O3 and quartz due to the adsorption of migrated low molecular weight (LMW) polydimethylsiloxanes. Specimens contaminated by active carbon could achieve surface hydrophobicity within 15 min because active carbon has high adsorbability. Surfaces of contaminated ultrapure SIR, polytetrafluoroethylene (PTFE) and glass remain hydrophilic because they contain no mobile LMW components. The addition of oligomeric polydimethylsiloxanes has little effect on the hydrophobicity of contaminants covered on SIR surface.展开更多
The aim of this study was to synthesize zinc borate using zinc oxide, reference boric acid, and reference zinc borate (reference ZB) as the seed, and to investigate the effects of modifying agents and reaction param...The aim of this study was to synthesize zinc borate using zinc oxide, reference boric acid, and reference zinc borate (reference ZB) as the seed, and to investigate the effects of modifying agents and reaction parameters on the hydrophobicity and yield, respectively. The reaction parameters include reaction time (1-5 h), reactant ratio (H3BO3/ZnO by mass: 2-5), seed ratio (seed crystal/(H3BO3+ZnO) by mass: 0-2wt%), reaction temperature (50-120~C), cooling temperature (10-80~C), and stirring rate (400-700 r/min); the modifying agents involve propylene glycol (PG, 0-6wt%), kerosene (lwt%-6wt%), and oleic acid (OA, lwt%-6wt%) with solvents (isopropyl alcohol (IPA), ethanol, and methanol). The results of reaction yield obtained from either magnetically or mechanically stirred systems were compared. Zinc borate produced was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and contact angle tests to identify the hydrophobicity. In conclusion, zinc borate is synthesized successfully under the optimized reaction conditions, and the different modifying agents with various solvents affect the hydrophobicity of zinc borate.展开更多
Copper nanoparticle was synthesized in the presence of heptadecafluorononanoic acid by the conventional solution immersion method at room temperature from the copper plate, as a resource material. The bulk etching rat...Copper nanoparticle was synthesized in the presence of heptadecafluorononanoic acid by the conventional solution immersion method at room temperature from the copper plate, as a resource material. The bulk etching rate was calculated by the weight loss method. The pale green colored Cu-HDFN was characterized by Fourier transform infrared spectroscopy, UV-Visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and contact angle measurements and the results are critically analyzed.展开更多
An atmospheric-pressure plasma jet array specially designed for HTV silicone rubber treatment is reported in this paper. Stable plasma containing highly energetic active particles was uniformly generated in the plasma...An atmospheric-pressure plasma jet array specially designed for HTV silicone rubber treatment is reported in this paper. Stable plasma containing highly energetic active particles was uniformly generated in the plasma jet array. The discharge pattern was affected by the applied voltage. The divergence phenomenon was observed at low gas flow rate and abated when the flow rate increased.Temperature of the plasma plume is close to room temperature which makes it feasible for temperature-sensitive material treatment. Hydrophobicity of contaminated HTV silicone rubber was significantly improved after quick exposure of the plasma jet array, and the effective treatment area reached 120 mm?×?50 mm(length?×?width). Reactive particles in the plasma accelerate accumulation of the hydrophobic molecules, namely low molecular weight silicone chains, on the contaminated surface, which result in a hydrophobicity improvement of the HTV silicone rubber.展开更多
In this paper,we presented a novel strategy to employ a plantderived carbohydrate polymer,i.e.,cellulose,to prepare a hydrophobic composite.Cellulose was used as a scaffold,and ethylene-propylene side by side(ES)fiber...In this paper,we presented a novel strategy to employ a plantderived carbohydrate polymer,i.e.,cellulose,to prepare a hydrophobic composite.Cellulose was used as a scaffold,and ethylene-propylene side by side(ES)fiber was thermally melted and then coated on the cellulose surface to achieve hydrophobicity.Experimental results revealed that the thermocoating ES fibers greatly increased the water contact angle of the cellulose scaffold from 25°to 153°while simultaneously enhanced the wet tensile strength of the composite approximately 6.7-fold(drying temperature of 170℃)compared with the pure cellulose paper.In particular,compared with other related research,the prepared cellulose-based composite possessed excellent hydrophobicity and superior mechanical strength,which introduces a new chemical engineering approach to prepare hydrophobic cellulose-based functional materials.展开更多
Although multifunctional aerogels are expected to be used in applications such as portable electronic devices,it is still a great challenge to confer multifunctionality to aerogels while maintaining their inherent mic...Although multifunctional aerogels are expected to be used in applications such as portable electronic devices,it is still a great challenge to confer multifunctionality to aerogels while maintaining their inherent microstructure.Herein,a simple method is proposed to prepare multifunctional NiCo/C aerogels with excellent electromagnetic wave absorption properties,superhydrophobicity,and self-cleaning by water-induced NiCo-MOF self-assembly.Specifically,the impedance matching of the three-dimensional(3D)structure and the interfacial polarization provided by CoNi/C as well as the defect-induced dipole polarization are the primary contributors to the broadband absorption.As a result,the prepared NiCo/C aerogels have a broadband width of 6.22 GHz at 1.9 mm.Due to the presence of hydrophobic functional groups,CoNi/C aerogels improve the stability in humid environments and obtain hydrophobicity with large contact angles>140°.This multifunctional aerogel has promising applications in electromagnetic wave absorption,resistance to water or humid environments.展开更多
Highly ordered silicon nanorod(Si NR) arrays with controllable geometry are fabricated via nanosphere lithography and metal-assisted chemical etching. It is demonstrated that the key to achieving a high-quality meta...Highly ordered silicon nanorod(Si NR) arrays with controllable geometry are fabricated via nanosphere lithography and metal-assisted chemical etching. It is demonstrated that the key to achieving a high-quality metal mask is to construct a non-close-packed template that can be removed with negligible damage to the mask. Hydrophobicity of Si NR arrays of different geometries is also studied. It is shown that the nanorod structures are effectively quasi-hydrophobic with a contact angle as high as 142°, which would be useful in self-cleaning nanorod-based device applications.展开更多
Non-thermal plasmas under atmospheric pressure are of great interest in industrial applications, especially in material surface treatment. In this paper, the treatment of a glass surface for improving hydrophobicity u...Non-thermal plasmas under atmospheric pressure are of great interest in industrial applications, especially in material surface treatment. In this paper, the treatment of a glass surface for improving hydrophobicity using the non-thermal plasma generated by dielectric barrier discharge (DBD) at atmospheric pressure in ambient air is conducted, and the surface properties of the glass before and after the DBD treatment are studied by using contact angle measurement, surface resistance measurement and wet flashover voltage tests. The effects of the applied voltage and time duration of DBD on the surface modification are studied, and the optimal conditions for the treatment are obtained. It is found that a layer of hydrophobic coating is formed on the glass surface after spraying a thin layer of silicone oil and undergoing the DBD treatment, and the improvement of hydrophobicity depends on DBD voltage and treating time. It seems that there exists an optimum treating time for a certain applied voltage of DBD during the surface treatment, The test results of thermal aging and chemical aging show that the hydrophobic layer has quite stable characteristics. The interaction mechanism between the DBD plasma and the glass surface is discussed. It is concluded that CHa and large molecule radicals can react with the radicals in the glass surface to replace OH, and the hydrophobicity of the glass surface is improved accordingly.展开更多
Additive manufacturing(AM)is a free-form technology that shows great potential in the integrated creation of three-dimensional(3D)electronics.However,the fabrication of 3D conformal circuits that fulfill the requireme...Additive manufacturing(AM)is a free-form technology that shows great potential in the integrated creation of three-dimensional(3D)electronics.However,the fabrication of 3D conformal circuits that fulfill the requirements of high service temperature,high conductivity and high resolution remains a challenge.In this paper,a hybrid AM method combining the fused deposition modeling(FDM)and hydrophobic treatment assisted laser activation metallization(LAM)was proposed for manufacturing the polyetheretherketone(PEEK)-based 3D electronics,by which the conformal copper patterns were deposited on the 3D-printed PEEK parts,and the adhesion between them reached the 5B high level.Moreover,the 3D components could support the thermal cycling test from-55℃ to 125℃ for more than 100 cycles.Particularly,the application of a hydrophobic coating on the FDM-printed PEEK before LAM can promote an ideal catalytic selectivity on its surface,not affected by the inevitable printing borders and pores in the FDM-printed parts,then making the resolution of the electroless plated copper lines improved significantly.In consequence,Cu lines with width and spacing of only60μm and 100μm were obtained on both as-printed and after-polished PEEK substrates.Finally,the potential of this technique to fabricate 3D conformal electronics was demonstrated.展开更多
Wellbore instability,especially drilling with water-based drilling fluids(WBDFs)in complex shale for-mations,is a critical challenge for oil and gas development.The purpose of this paper is to study the feasibility of...Wellbore instability,especially drilling with water-based drilling fluids(WBDFs)in complex shale for-mations,is a critical challenge for oil and gas development.The purpose of this paper is to study the feasibility of using hydrophobically modified silica nanoparticle(HMN)to enhance the comprehensive performance of WBDFs in the Xinjiang Oilfield,especially the anti-collapse performance.The effect of HMN on the overall performance of WBDFs in the Xinjiang Oilfield,including inhibition,plugging,lu-bricity,rheology,and filtration loss,was studied with a series of experiments.The mechanism of HMN action was studied by analyzing the changes of shale surface structure and chemical groups,wettability,and capillary force.The experimental results showed that HMN could improve the performance of WBDFs in the Xinjiang Oilfeld to inhibit the hydration swelling and dispersion of shale.The plugging and lubrication performance of the WBDFs in the Xinjiang Oilfield were also enhanced with HMN based on the experimental results.HMN had less impact on the rheological and filtration performance of the WBDFs in the Xinjiang Oilfield.In addition,HMN significantly prevented the decrease of shale strength.The potential mechanism of HMN was as follows.The chemical composition and structure of the shale surface were altered due to the adsorption of HMN driven by electrostatic attraction.Changes of the shale surface resulted in significant wettability transition.The capillary force of the shale was converted from a driving force of water into the interior to a resistance.In summary,hydrophobic nanoparticles presented afavorable application potential for WBDFs.展开更多
In recent years, researches published on hydrophobic materials increase rapidly, wherein the method for changing hydrophobicity by modifying a micro-array structure on the surface of the material also has been propose...In recent years, researches published on hydrophobic materials increase rapidly, wherein the method for changing hydrophobicity by modifying a micro-array structure on the surface of the material also has been proposed. Of course, if it is possible for us to quantitatively analyse and evaluate hydrophobicity of different structures of one certain material at first, this task will greatly optimize the design of actual structures. In this work, we used the algorithm for Laminar Two-Phase Flow, Horizontal-set method integrated in COMSOL to build two single-pore simulation structures in different shapes and simulated the behaviour of the liquid transition from Cassie-state to Wenzel-state during the impregnation process. After that, the intrinsic contact angle of Structure T (a porous structure with a T-shaped sectional profile) was obtained under a certain pressure which maintained liquids in Cassie-state. Meanwhile, two equilibrium states of the liquid-air interface as well as two different patterns of the equilibrium state disrupting were found in Structure R (a porous structure with a Chamfered T-shaped sectional profile). Simulation results show that the modelling method can be applied for simulating the hydrophobicity of different porous structures and optimizing the procedures for the design of the micro-array efficiently.展开更多
Alumina(Al_(2)O_(3))is widely used in the chemical industry as the catalyst and support due to its high specific surface area,abundant pore size distribution and chemical stability.However,the occurrence of hydration ...Alumina(Al_(2)O_(3))is widely used in the chemical industry as the catalyst and support due to its high specific surface area,abundant pore size distribution and chemical stability.However,the occurrence of hydration in water environment,result in outstanding decrease in specific surface area and collapse of pore structure.In this work,dodecyl phosphoric acid(PA)is used to modify the surface of Al_(2)O_(3)to obtain a series of hydrophobic material(Al_(2)O_(3)-PA).Based on XPS and NMR analysis,PA is chemically bonded on Al_(2)O_(3)to form PAOAAl bond.Furthermore,BET and WCA results display that Al_(2)O_(3)-1PA exhibits excellent the hydrophobicity and hydrothermal stability while maintains the pore structure.Take it as the substrate to support the Pd nanoparticles,the as-prepared Pd/Al_(2)O_(3)-PA shows the superior catalytic performance in the hydrogenation of phenol and anthraquinone relative to Pd/Al_(2)O_(3),indicating the accessibility of Pd sites after PA modification.Especially,the significantly enhanced stability is also obtained in four cycles for aqueous phenol hydrogenation.This can be ascribed that the PA modification inhibits the aggregation of Pd nanoparticles and the products adhesion in the reaction process.The extension of PA coatings to monolithic catalysts could expand their current capabilities in industrial applications and warrants ongoing investigation.展开更多
The hydrophobicity of polluted silicone rubber was improved rapidly under plasma jet treatment.It is an important phenomenon of the interaction between the plasma jet and the porous surface,and shows a wide applicatio...The hydrophobicity of polluted silicone rubber was improved rapidly under plasma jet treatment.It is an important phenomenon of the interaction between the plasma jet and the porous surface,and shows a wide application prospect in the power system.In this process,the spatial characteristics and dose of plasma jet are very important.Therefore,the variation of hydrophobicity of polluted silicone rubber under plasma jet treatment was studied,and the spatial characteristics and dose of plasma jet on polluted silicone rubber were also investigated in the work.The results show that the surface property(hydrophilic or hydrophobic)depended on the dose of plasma applied to the surface.The effective treated area was a circle,and the contact angles changed along the radial direction of the circle.This was attributable to the diffusion of plasma bullets on the surface and the distribution of plasma species.The plasma dose could be characterized by the energy density of the plasma applied on the surface.With the increase of plasma dose,the surface contact angles first increased rapidly and then decreased gradually.展开更多
Novel plastics that are biodegradable, environmentally benign, and made from renewable natural resources are currently being researched as alternatives to traditional petroleum-based plastics. One such plastic, thermo...Novel plastics that are biodegradable, environmentally benign, and made from renewable natural resources are currently being researched as alternatives to traditional petroleum-based plastics. One such plastic, thermoplastic starch (TPS) is produced from starch processed at high temperatures in the presence of plasticizers, such as water and glycerol. However, because of its hydrophilic nature, TPS exhibits poor mechanical properties when exposed to environmental conditions, such as rain or humidity. The overall objective of this research work was to produce a thermoplastic starch based material with low water absorption that may be used to replace petroleum-based plastics. With a recent emergence of “green” polyethylene (GPE), sourced from renewable feedstock, it has become possible to develop novel biodegradable polymers for various applications. In this work, GPE was melt blended with starch in three different ways;reactive extrusion of GPE and starch facilitated by maleic anhydride (MAH) and dicumyl peroxide (DCP), melt blending of GPE and starch by extrusion, and melt blending of maleated polyethylene and starch by extrusion. Comprehensive testing and analysis has shown that all methods reduced water absorption significantly with some variations across the board.展开更多
基金supported by the Beijing Municipal Natural Science Foundation(JQ20015)National Key Research and Development Program of China(No.2022YFB4601300)+3 种基金the National Science Fund for Distinguished Young Scholars(No.52325505)the National Natural Science Foundation of China(NSFC)(No.52075041)the Joint Funds of the National Natural Science Foundation of China(Grant No.U2037205)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No2021WNLOKF016)。
文摘The controllable transfer of droplets on the surface of objects has a wide application prospect in the fields of microfluidic devices,fog collection and so on.The Leidenfrost effect can be utilized to significantly reduce motion resistance.However,the use of 3D structures limits the widespread application of self-propulsion based on Leidenfrost droplets in microelectromechanical system.To manipulate Leidenfrost droplets,it is necessary to create 2D or quasi-2D geometries.In this study,femtosecond laser is applied to fabricate a surface with periodic hydrophobicity gradient(SPHG),enabling directional self-propulsion of Leidenfrost droplets.Flow field analysis within the Leidenfrost droplets reveals that the vapor layer between the droplets and the hot surface can be modulated by the SPHG,resulting in directional propulsion of the inner gas.The viscous force between the gas and liquid then drives the droplet to move.
基金supported by the China Postdoctoral Science Foundation(No.2021MD703944)the Fund of Science and Technology on Near-Surface Detection Laboratory(No.6142414211808)+1 种基金the Director Fund of State Key Laboratory of Pulsed Power Laser Technology(No.SKL2021ZR06)the National Natural Science Foundation of China(No.21776053)。
文摘Reduced graphene oxide(rGO)aerogels are emerging as very attractive scaffolds for high-performance electromagnetic wave absorption materials(EWAMs)due to their intrinsic conductive networks and intricate interior microstructure,as well as good compatibility with other electromagnetic(EM)components.Herein,we realized the decoration of rGO aerogel with Mo_(2)C nanoparticles by sequential hydrothermal assembly,freeze-drying,and high-temperature pyrolysis.Results show that Mo_(2)C nanoparticle loading can be easily controlled by the ammonium molybdate to glucose molar ratio.The hydrophobicity and thermal insulation of the rGO aerogel are effectively improved upon the introduction of Mo_(2)C nanoparticles,and more importantly,these nanoparticles regulate the EM properties of the rGO aerogel to a large extent.Although more Mo_(2)C nanoparticles may decrease the overall attenuation ability of the rGO aerogel,they bring much better impedance matching.At a molar ratio of 1:1,a desirable balance between attenuation ability and impedance matching is observed.In this context,the Mo_(2)C/r GO aerogel displays strong reflection loss and broad response bandwidth,even with a small applied thickness(1.7 mm)and low filler loading(9.0wt%).The positive effects of Mo_(2)C nanoparticles on multifunctional properties may render Mo_(2)C/r GO aerogels promising candidates for high-performance EWAMs under harsh conditions.
基金the support from the National Key Research and Development Program of China (2021YFB3801303)the National Natural Science Foundation of China (21838005, 21921006)the Key Scientific Research and Development Projects of Jiangsu Province (BE201800901)。
文摘Although hydrophilic membranes are desired for reducing resistance to water permeation, hydrophilic surfaces are not used in the water-in-oil(W/O) membrane emulsification process because water spreads on the hydrophilic surface without forming droplets. Here, we report that a hydrophilic ceramic membrane can form a hydrophobic interface in diesel at a higher temperature;interestingly, the experiments show that the contact angle increases when the temperature rises. The hydrophilic membrane surface evolves into a hydrophobic interface, particularly near the boiling point of water, resulting in a water contact angle of 147.5° ± 1.2°. This work established a method for preparing W/O monodispersed emulsions by direct emulsification of hydrophilic ceramic membranes at a temperature close to the boiling point of water.Additionally, it made high flux of membrane emulsification of monodispersed W/O emulsions possible,which satisfied the industrial requirements of fluidized catalytic cracking in the petrochemical industry.
基金supported by the National Natural Science Foundation of China(51772329,51972340,and 51825201)。
文摘Developing metal-organic framework(MOF)materials with the moisture-resistant feature is highly desirable for CO_(2)capture from highly humid flue gas.In this work,a new core-shell MOF@MOF composite using Mg-MOF-74 with high CO_(2)capture capacity as a functional core and hydrophobic zeolitic imidazolate framework-8(ZIF-8)as a protective shell is fabricated by the epitaxial growth method.Experimental results show that the CO_(2)adsorption performance of the core-shell structured Mg-MOF-74@ZIF-8 composites from water-containing flue gas is enhanced along with their improved hydrophobicity.The dynamic breakthrough results show that the Mg-MOF-74@ZIF-8 with three assembled layers(Mg-MOF-74@ZIF-8-3)can capture 3.56 mmol-g^(-1)CO_(2)from wet CO_(2)/N_(2)(VCO_(2):V_(N_(2))=15:85)mixtures,which outperforms Mg-MOF-74(0.37 mmol·g^(-1))and most of the reported physisorbents.
基金financially supported by the National Natural Science Foundation of China(22378204,22008121,51790492)the National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(T2125004)+1 种基金the Funding of NJUST(No.TSXK2022D002)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_0454)。
文摘The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR involves two half-reactions:the CO_(2) reduction half-reaction(CRHR)and the water oxidation half-reaction(WOHR).Generally,both half-reactions can be promoted by adjusting the wettability of catalysts.However,there is a contradiction in wettability requirements for the two half-reactions.Specifically,CRHR prefers a hydrophobic surface that can accumulate more CO_(2) molecules on the active sites,ensuring the appropriate ratio of gas-phase(CO_(2))to liquid-phase(H_(2)O)reactants.Conversely,the WOHR prefers a hydrophilic surface that can promote the departure of the gaseous product(O_(2))from the catalyst surface,preventing isolation between active sites and the reactant(H_(2)O).Here,we successfully reconciled the contradictory wettability requirements for the CRHR and WOHR by creating an alternately hydrophobic catalyst.This was achieved through a selectively hydrophobic modification method and a charge-transfer-control strategy.Consequently,the collaboratively promoted CRHR and WOHR led to a significantly enhanced OPCRR with a solar-to-fuel conversion efficiency of 0.186%.Notably,in ethanol production,the catalyst exhibited a 10.64-fold increase in generation rate(271.44μmol g^(-1)h~(-1))and a 4-fold increase in selectivity(55.77%)compared to the benchmark catalyst.This innovative approach holds great potential for application in universal overall reactions involving gas participation.
文摘Silicone rubber (SIR) shows superior performance when used outdoors, but its surface can be transformed from inherently hydrophobic to hydrophilic by the adsorption of contaminants. Al(OH)(3), Al2O3, quartz powder and active carbon were selected as authentic contaminants. Hydrophobicity of the surface was determined using contact angle measurement. The results indicate that the adsorbability of the contaminants can strongly affect the hydrophobicity of contaminated SIR surface. The increasing rate of contact angle of specimens contaminated by Al(OH)(3) was much faster than that by Al2O3 and quartz due to the adsorption of migrated low molecular weight (LMW) polydimethylsiloxanes. Specimens contaminated by active carbon could achieve surface hydrophobicity within 15 min because active carbon has high adsorbability. Surfaces of contaminated ultrapure SIR, polytetrafluoroethylene (PTFE) and glass remain hydrophilic because they contain no mobile LMW components. The addition of oligomeric polydimethylsiloxanes has little effect on the hydrophobicity of contaminants covered on SIR surface.
文摘The aim of this study was to synthesize zinc borate using zinc oxide, reference boric acid, and reference zinc borate (reference ZB) as the seed, and to investigate the effects of modifying agents and reaction parameters on the hydrophobicity and yield, respectively. The reaction parameters include reaction time (1-5 h), reactant ratio (H3BO3/ZnO by mass: 2-5), seed ratio (seed crystal/(H3BO3+ZnO) by mass: 0-2wt%), reaction temperature (50-120~C), cooling temperature (10-80~C), and stirring rate (400-700 r/min); the modifying agents involve propylene glycol (PG, 0-6wt%), kerosene (lwt%-6wt%), and oleic acid (OA, lwt%-6wt%) with solvents (isopropyl alcohol (IPA), ethanol, and methanol). The results of reaction yield obtained from either magnetically or mechanically stirred systems were compared. Zinc borate produced was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and contact angle tests to identify the hydrophobicity. In conclusion, zinc borate is synthesized successfully under the optimized reaction conditions, and the different modifying agents with various solvents affect the hydrophobicity of zinc borate.
文摘Copper nanoparticle was synthesized in the presence of heptadecafluorononanoic acid by the conventional solution immersion method at room temperature from the copper plate, as a resource material. The bulk etching rate was calculated by the weight loss method. The pale green colored Cu-HDFN was characterized by Fourier transform infrared spectroscopy, UV-Visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and contact angle measurements and the results are critically analyzed.
基金supported in part by National Natural Science Foundation of China (Grant No. 51677105)Key project of Shenzhen Technology Innovation Plan (JSGG20170412151407005)
文摘An atmospheric-pressure plasma jet array specially designed for HTV silicone rubber treatment is reported in this paper. Stable plasma containing highly energetic active particles was uniformly generated in the plasma jet array. The discharge pattern was affected by the applied voltage. The divergence phenomenon was observed at low gas flow rate and abated when the flow rate increased.Temperature of the plasma plume is close to room temperature which makes it feasible for temperature-sensitive material treatment. Hydrophobicity of contaminated HTV silicone rubber was significantly improved after quick exposure of the plasma jet array, and the effective treatment area reached 120 mm?×?50 mm(length?×?width). Reactive particles in the plasma accelerate accumulation of the hydrophobic molecules, namely low molecular weight silicone chains, on the contaminated surface, which result in a hydrophobicity improvement of the HTV silicone rubber.
基金supported by Natural Science Foundation of China(No.31770624 and No.21978029)National Key R&D Program of China(No.2018YFD0400703)+2 种基金Natural Science Foundation of Liaoning(No.20170540069)the Program for Liaoning Excellent Talents in University(LR2016058)Liaoning Million Talents Program(201945).
文摘In this paper,we presented a novel strategy to employ a plantderived carbohydrate polymer,i.e.,cellulose,to prepare a hydrophobic composite.Cellulose was used as a scaffold,and ethylene-propylene side by side(ES)fiber was thermally melted and then coated on the cellulose surface to achieve hydrophobicity.Experimental results revealed that the thermocoating ES fibers greatly increased the water contact angle of the cellulose scaffold from 25°to 153°while simultaneously enhanced the wet tensile strength of the composite approximately 6.7-fold(drying temperature of 170℃)compared with the pure cellulose paper.In particular,compared with other related research,the prepared cellulose-based composite possessed excellent hydrophobicity and superior mechanical strength,which introduces a new chemical engineering approach to prepare hydrophobic cellulose-based functional materials.
基金financially supported by the National Natural Science Foundation of China (No.51407134, No.52002196)Natural Science Foundation of Shandong Province (No.ZR2019YQ24, No.ZR2020QF084)+2 种基金Taishan Scholars and Young Experts Program of Shandong Province (No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution (Research and Innovation Team of Structural-Functional Polymer Composites)Special Financial of Shandong Province (Structural Design of Highefficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Talent Teams (No. 37000022P990304116449))
文摘Although multifunctional aerogels are expected to be used in applications such as portable electronic devices,it is still a great challenge to confer multifunctionality to aerogels while maintaining their inherent microstructure.Herein,a simple method is proposed to prepare multifunctional NiCo/C aerogels with excellent electromagnetic wave absorption properties,superhydrophobicity,and self-cleaning by water-induced NiCo-MOF self-assembly.Specifically,the impedance matching of the three-dimensional(3D)structure and the interfacial polarization provided by CoNi/C as well as the defect-induced dipole polarization are the primary contributors to the broadband absorption.As a result,the prepared NiCo/C aerogels have a broadband width of 6.22 GHz at 1.9 mm.Due to the presence of hydrophobic functional groups,CoNi/C aerogels improve the stability in humid environments and obtain hydrophobicity with large contact angles>140°.This multifunctional aerogel has promising applications in electromagnetic wave absorption,resistance to water or humid environments.
基金Project supported by the National Natural Science Foundation of China(Grant No.51272246)the Scientific and Technological Research Foundation of Anhui Province,China(Grant No.12010202035)
文摘Highly ordered silicon nanorod(Si NR) arrays with controllable geometry are fabricated via nanosphere lithography and metal-assisted chemical etching. It is demonstrated that the key to achieving a high-quality metal mask is to construct a non-close-packed template that can be removed with negligible damage to the mask. Hydrophobicity of Si NR arrays of different geometries is also studied. It is shown that the nanorod structures are effectively quasi-hydrophobic with a contact angle as high as 142°, which would be useful in self-cleaning nanorod-based device applications.
文摘Non-thermal plasmas under atmospheric pressure are of great interest in industrial applications, especially in material surface treatment. In this paper, the treatment of a glass surface for improving hydrophobicity using the non-thermal plasma generated by dielectric barrier discharge (DBD) at atmospheric pressure in ambient air is conducted, and the surface properties of the glass before and after the DBD treatment are studied by using contact angle measurement, surface resistance measurement and wet flashover voltage tests. The effects of the applied voltage and time duration of DBD on the surface modification are studied, and the optimal conditions for the treatment are obtained. It is found that a layer of hydrophobic coating is formed on the glass surface after spraying a thin layer of silicone oil and undergoing the DBD treatment, and the improvement of hydrophobicity depends on DBD voltage and treating time. It seems that there exists an optimum treating time for a certain applied voltage of DBD during the surface treatment, The test results of thermal aging and chemical aging show that the hydrophobic layer has quite stable characteristics. The interaction mechanism between the DBD plasma and the glass surface is discussed. It is concluded that CHa and large molecule radicals can react with the radicals in the glass surface to replace OH, and the hydrophobicity of the glass surface is improved accordingly.
基金supported by the National Natural Science Foundation of China(Grant No.51901082)the National Postdoctoral Program for Innovative Talents(BX20200137)the National Defense Basic Scientific Research Program of China(JCKY2018110C060)。
文摘Additive manufacturing(AM)is a free-form technology that shows great potential in the integrated creation of three-dimensional(3D)electronics.However,the fabrication of 3D conformal circuits that fulfill the requirements of high service temperature,high conductivity and high resolution remains a challenge.In this paper,a hybrid AM method combining the fused deposition modeling(FDM)and hydrophobic treatment assisted laser activation metallization(LAM)was proposed for manufacturing the polyetheretherketone(PEEK)-based 3D electronics,by which the conformal copper patterns were deposited on the 3D-printed PEEK parts,and the adhesion between them reached the 5B high level.Moreover,the 3D components could support the thermal cycling test from-55℃ to 125℃ for more than 100 cycles.Particularly,the application of a hydrophobic coating on the FDM-printed PEEK before LAM can promote an ideal catalytic selectivity on its surface,not affected by the inevitable printing borders and pores in the FDM-printed parts,then making the resolution of the electroless plated copper lines improved significantly.In consequence,Cu lines with width and spacing of only60μm and 100μm were obtained on both as-printed and after-polished PEEK substrates.Finally,the potential of this technique to fabricate 3D conformal electronics was demonstrated.
基金the National Natural Science Foundation of China(51904329,52174014)the Major Scientific and Technological Projects of CNPC(ZD 2019-183-005)Key R&D Program of Shandong Province(No.2020ZLYS07).
文摘Wellbore instability,especially drilling with water-based drilling fluids(WBDFs)in complex shale for-mations,is a critical challenge for oil and gas development.The purpose of this paper is to study the feasibility of using hydrophobically modified silica nanoparticle(HMN)to enhance the comprehensive performance of WBDFs in the Xinjiang Oilfield,especially the anti-collapse performance.The effect of HMN on the overall performance of WBDFs in the Xinjiang Oilfield,including inhibition,plugging,lu-bricity,rheology,and filtration loss,was studied with a series of experiments.The mechanism of HMN action was studied by analyzing the changes of shale surface structure and chemical groups,wettability,and capillary force.The experimental results showed that HMN could improve the performance of WBDFs in the Xinjiang Oilfeld to inhibit the hydration swelling and dispersion of shale.The plugging and lubrication performance of the WBDFs in the Xinjiang Oilfield were also enhanced with HMN based on the experimental results.HMN had less impact on the rheological and filtration performance of the WBDFs in the Xinjiang Oilfield.In addition,HMN significantly prevented the decrease of shale strength.The potential mechanism of HMN was as follows.The chemical composition and structure of the shale surface were altered due to the adsorption of HMN driven by electrostatic attraction.Changes of the shale surface resulted in significant wettability transition.The capillary force of the shale was converted from a driving force of water into the interior to a resistance.In summary,hydrophobic nanoparticles presented afavorable application potential for WBDFs.
文摘In recent years, researches published on hydrophobic materials increase rapidly, wherein the method for changing hydrophobicity by modifying a micro-array structure on the surface of the material also has been proposed. Of course, if it is possible for us to quantitatively analyse and evaluate hydrophobicity of different structures of one certain material at first, this task will greatly optimize the design of actual structures. In this work, we used the algorithm for Laminar Two-Phase Flow, Horizontal-set method integrated in COMSOL to build two single-pore simulation structures in different shapes and simulated the behaviour of the liquid transition from Cassie-state to Wenzel-state during the impregnation process. After that, the intrinsic contact angle of Structure T (a porous structure with a T-shaped sectional profile) was obtained under a certain pressure which maintained liquids in Cassie-state. Meanwhile, two equilibrium states of the liquid-air interface as well as two different patterns of the equilibrium state disrupting were found in Structure R (a porous structure with a Chamfered T-shaped sectional profile). Simulation results show that the modelling method can be applied for simulating the hydrophobicity of different porous structures and optimizing the procedures for the design of the micro-array efficiently.
基金supported by National Key Research&Development Program of China(2021YFB3801600)Fundamental Research Funds for the Central University(buctrc201921,JD2223,12060093063)Innovative Achievement Commercialization Service-Platform of Industrial Catalysis(2019-00900-2-1).
文摘Alumina(Al_(2)O_(3))is widely used in the chemical industry as the catalyst and support due to its high specific surface area,abundant pore size distribution and chemical stability.However,the occurrence of hydration in water environment,result in outstanding decrease in specific surface area and collapse of pore structure.In this work,dodecyl phosphoric acid(PA)is used to modify the surface of Al_(2)O_(3)to obtain a series of hydrophobic material(Al_(2)O_(3)-PA).Based on XPS and NMR analysis,PA is chemically bonded on Al_(2)O_(3)to form PAOAAl bond.Furthermore,BET and WCA results display that Al_(2)O_(3)-1PA exhibits excellent the hydrophobicity and hydrothermal stability while maintains the pore structure.Take it as the substrate to support the Pd nanoparticles,the as-prepared Pd/Al_(2)O_(3)-PA shows the superior catalytic performance in the hydrogenation of phenol and anthraquinone relative to Pd/Al_(2)O_(3),indicating the accessibility of Pd sites after PA modification.Especially,the significantly enhanced stability is also obtained in four cycles for aqueous phenol hydrogenation.This can be ascribed that the PA modification inhibits the aggregation of Pd nanoparticles and the products adhesion in the reaction process.The extension of PA coatings to monolithic catalysts could expand their current capabilities in industrial applications and warrants ongoing investigation.
基金supported by the Intergovernmental International Cooperation in Science and Technology Innovation Program(No.2019YFE0115600)National Natural Science Foundation of China(No.52177152)Science,Technology and Innovation Commission of Shenzhen Municipality(No.JCYJ20180508152057527)。
文摘The hydrophobicity of polluted silicone rubber was improved rapidly under plasma jet treatment.It is an important phenomenon of the interaction between the plasma jet and the porous surface,and shows a wide application prospect in the power system.In this process,the spatial characteristics and dose of plasma jet are very important.Therefore,the variation of hydrophobicity of polluted silicone rubber under plasma jet treatment was studied,and the spatial characteristics and dose of plasma jet on polluted silicone rubber were also investigated in the work.The results show that the surface property(hydrophilic or hydrophobic)depended on the dose of plasma applied to the surface.The effective treated area was a circle,and the contact angles changed along the radial direction of the circle.This was attributable to the diffusion of plasma bullets on the surface and the distribution of plasma species.The plasma dose could be characterized by the energy density of the plasma applied on the surface.With the increase of plasma dose,the surface contact angles first increased rapidly and then decreased gradually.
文摘Novel plastics that are biodegradable, environmentally benign, and made from renewable natural resources are currently being researched as alternatives to traditional petroleum-based plastics. One such plastic, thermoplastic starch (TPS) is produced from starch processed at high temperatures in the presence of plasticizers, such as water and glycerol. However, because of its hydrophilic nature, TPS exhibits poor mechanical properties when exposed to environmental conditions, such as rain or humidity. The overall objective of this research work was to produce a thermoplastic starch based material with low water absorption that may be used to replace petroleum-based plastics. With a recent emergence of “green” polyethylene (GPE), sourced from renewable feedstock, it has become possible to develop novel biodegradable polymers for various applications. In this work, GPE was melt blended with starch in three different ways;reactive extrusion of GPE and starch facilitated by maleic anhydride (MAH) and dicumyl peroxide (DCP), melt blending of GPE and starch by extrusion, and melt blending of maleated polyethylene and starch by extrusion. Comprehensive testing and analysis has shown that all methods reduced water absorption significantly with some variations across the board.