The natural hydrophobicity of surfaces can be enhanced if they are microtextured due to air trapped in the structure, which provides the deposited drop with a composite surface made of solid and air on which it is res...The natural hydrophobicity of surfaces can be enhanced if they are microtextured due to air trapped in the structure, which provides the deposited drop with a composite surface made of solid and air on which it is rest. Here, a series of grating microstructure surfaces with different parameters have been designed and fabricated by a novel soft lithography. The water contact angles （WCA） on these rough surfaces are measured through optical contact angle meter. The results indicate that all the WCA on the surfaces with grating microstructures are up to 150~; WCA increases and the hydrophobic performance also enhances with the decrease of the ridge width under the other fixed parameter condition; Experimental data obtained basically consists with the Cassie＇s theoretical prediction. The effects of geometric parameters of the microstructures on wettability of the grating sufaces are investigated.展开更多
Fibers have been of great significance in our daily lives,especially in the industrial production of masks.Research in this area has been focused on developing microfibers with superior functions to enhance the filtra...Fibers have been of great significance in our daily lives,especially in the industrial production of masks.Research in this area has been focused on developing microfibers with superior functions to enhance the filtration performances of the masks.Herein,inspired by the frog’s predation mechanism using its tongues to swiftly grab flying insects,we propose novel porous wettable microfibers from microfluidics to efficiently capture particles in the air for filtration.Upon pre-dispersing LP emulsions into polyurethane(PU),porous microfibers dispersed with oil droplets could be continuously spun from a co-flow microfluidic device based on the quick phase inversion of PU.To design an optimal system with frog-tongue-like interfacial adhesion properties,the wettability performances of the porous microfibers are investigated under full,partial,and no oil coverage conditions.When implemented in a mask,the 3D patterned networks based on the frog-tongue-inspired microfibers have been proven with remarkable particle capture performances while maintaining good air permeability.Based on these features,we believe that frog-tongue-inspired microfibers and their derived masks are of practical significance in multiple applications.展开更多
This study investigated surface roughness,the wettability behavior,and surface energy of Co-based alloy specimens textured using the biomimetic Laser Surface Texturing(LST)method.The surface texture was inspired by th...This study investigated surface roughness,the wettability behavior,and surface energy of Co-based alloy specimens textured using the biomimetic Laser Surface Texturing(LST)method.The surface texture was inspired by the patterns found on marine shells.The impacts of the parameters on wettability,Surface Free Energy(SFE),surface topography,and texture roughness generated by the laser beam tracking a spiral path were investigated.Reducing spiral pitch produces more complicated and chaotic surface patterns.Most surfaces are hydrophobic,and surface roughness and topography influence the Contact Angle(CA).Topography and roughness were affected by frequency and scanning speed;a decrease in scanning speed and frequency generated more chaotic and irregular surface textures.With general factorial analysis and Analysis of Variance(ANOVA),our statistical study reveals that accounting for 88%of the influence,the scanning speed is the primary factor influencing surface roughness.On the other hand,the spiral pitch is essential for defining the struc-tural features of the surface,even if it less influences roughness.The SFE of laser-textured CoCr28Mo alloy specimens was optimizable within the range of 14-32 mN/m.The relevant findings offer valuable insights into optimizing LST for the specific surface properties of the Co-based alloy.展开更多
In Chin.Phys.B 34114704(2025),Eq.(7)and the associated unit notation were incorrect.The correct ones are present here.Since Eq.(7)is an in-built expression in the simulation package,the correction is purely typographi...In Chin.Phys.B 34114704(2025),Eq.(7)and the associated unit notation were incorrect.The correct ones are present here.Since Eq.(7)is an in-built expression in the simulation package,the correction is purely typographical and does not affect the simulation procedure,numerical results,or the conclusions.展开更多
Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,a...Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.展开更多
Unidirectional liquid transport(UDLT)has been widely used in various fields as an important process for transferring both mass and energy.However,UDLT driven by a structural gradient has been witnessed for a long time...Unidirectional liquid transport(UDLT)has been widely used in various fields as an important process for transferring both mass and energy.However,UDLT driven by a structural gradient has been witnessed for a long time only in wettable liquids.For nonwettable liquids,UDLT can hardly proceed merely by a structural gradient.Herein,we propose an asymmetrically concave structured surface(AMC-surface),featuring tip-to-base periodically arranged pyramid-shaped concave structures with a certain degree of overlap,which enables the UDLT of both wettable and nonwettable liquids.For wettable liquids,the capillary force along each corner leads to the UDLT pointing toward the base side of the concave pyramid,while for nonwettable liquids,the UDLT is attributable to the static liquid pressure overwhelming the repulsive Laplace pressure induced by the asymmetric grooves and overlapping part.As a result,both wettable and nonwettable liquids transport spontaneously and unidirectionally on the AMC-surface with no energy input.Moreover,the concave structure endows good mechanical stability and can be easily prepared using a facile nail-punching approach over a large area.We also demonstrated its application in a continuous chemical reaction in a confined area.We envision that the unique UDLT behavior on the as-developed AMC-surface will shed new light on the programmable manipulation of various liquids.展开更多
In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypro...In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypropylene(PO)and oxyethylene(EO),octadecyl-(PO)_(m)-(EO)_(n)-sodium carboxylate(C_(18)PO_(m)EO_(n)C,m=5,10,15,n=5,10,15),were studied.The surface tension and contact angle of C_(18)PO_(m)EO_(n)C solution with different concentrations were measured,and the adhesion tension,PTFE-water interfacial tension,and adhesion work were calculated.It was found that the extended surfactant molecules adsorb on the surface of the solution and the PTFE-liquid interface simultaneously when the concentration is lower than the critical micelle concentration(cmc),and there was a linear relationship between surface tension and adhesion tension.The adsorption amount of C_(18)PO_(m)EO_(n)C at the PTFE-water interface was significantly lower than that on the surface of the solution.As the concentration increases above cmc,semi-micelle aggregates on the surface of PTFE are formed by C_(18)PO_(m)EO_(n)C molecules through hydrophobic interaction,and the hydrophilic group faces the solution to modify the surface of PTFE with high efficiency.展开更多
Oil-based drilling fluids possess excellent properties such as shale inhibition, cuttings suspension, and superior lubrication, making them essential in the development of unconventional oil and gas reservoirs.However...Oil-based drilling fluids possess excellent properties such as shale inhibition, cuttings suspension, and superior lubrication, making them essential in the development of unconventional oil and gas reservoirs.However, wellbore instability, caused by the invasion of drilling fluids into shale formations, remains a significant challenge for the safe and efficient extraction of shale oil and gas. This work reports the preparation of mesoporous SiO2nanoparticles with low surface energy, utilized as multifunctional agents to enhance the performance of oil-based drilling fluids aimed at improving wellbore stability. The results indicate that the coating prepared from these nanoparticles exhibit excellent hydrophobicity and antifouling properties, increasing the water contact angle from 32°to 146°and oil contact angle from 24°to134.8°. Additionally, these nanoparticles exhibit exceptional chemical stability and thermal resistance.Incorporating these nanoparticles into oil-based drilling fluids reduced the surface energy of the mud cake from 34.99 to 8.17 m J·m-2and increased the roughness of shale from 0.26 to 2.39 μm. These modifications rendered the mud cake and shale surfaces amphiphobic, effectively mitigating capillary infiltration and delaying the long-term strength degradation of shale in oil-based drilling fluids. After 28days of immersion in oil-based drilling fluid, shale cores treated with MF-SiO2exhibited a 30.5% increase in compressive strength compared to untreated cores. Additionally, these nanoparticles demonstrated the ability to penetrate and seal rock pores, reducing the API filtration volume of the drilling fluid from11.2 to 7.6 m L. This study introduces a novel approach to enhance the development of shale gas and oil resources, offering a promising strategy for wellbore stabilization in oil-based drilling fluid systems.展开更多
CO_(2)reduction reaction(CO_(2)RR)electrolyzers based on gas diffusion electrode(GDE)enable the direct mass transfer of CO_(2)to the catalyst surface for participation in the reaction,thereby establishing an efficient...CO_(2)reduction reaction(CO_(2)RR)electrolyzers based on gas diffusion electrode(GDE)enable the direct mass transfer of CO_(2)to the catalyst surface for participation in the reaction,thereby establishing an efficient three-phase reaction interface that significantly enhances current density.However,current hydrophobic modification methods face difficulties in achieving precise and substantial control over wettability,and the hydrophobic modifiers tend to significantly impair the conductivity of the electrode and ion transport capabilities.This study employs Nafion ionomers to hydrophobically modify the threedimensional catalyst layer,revealing the bifunctionality of Nafion.The fluorinated backbone of Nafion ensures the hydrophobicity of the entire catalyst layer,while its sulfonic acid groups promote ion transport,without significantly affecting the conductivity of the electrode.Furthermore,by employing modifiers with distinct wettability characteristics,a highly efficient and large-scale manipulation of the hydrophilic/hydrophobic properties of the catalyst layer was successfully realized.The electrode,constructed with silver nanopowder as a representative catalyst and modified with the hydrophobic ionomer Nafion,exhibits a substantial enhancement in both catalytic activity and durability.The optimized electrode exhibited exceptional electrocatalytic performance in both flow cell and membrane electrode assembly(MEA)configurations.Notably,in the MEA,the electrode achieved a remarkable CO Faradaic efficiency(FE)of 93.3%at a total current density of 200 mA cm^(-2),while maintaining stable operation for over 62 h.展开更多
The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human comfort.However,the development of smart and dynamic fabrics capable of mana...The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human comfort.However,the development of smart and dynamic fabrics capable of managing personal moisture/thermal comfort in response to changing external environments remains a challenge.Herein,a smart cellulose-based Janus fabric was designed to dynamically manage personal moisture/heat.The cotton fabric was grafted with N-isopropylacrylamide to construct a temperature-stimulated transport channel.Subsequently,hydrophobic ethyl cellulose and hydrophilic cellulose nanofiber were sprayed on the bottom and top sides of the fabric to obtain wettability gradient.The fabric exhibits anti-gravity directional liquid transportation from hydrophobic side to hydrophilic side,and can dynamically and continuously control the transportation time in a wide range of 3–66 s as the temperature increases from 10 to 40℃.This smart fabric can quickly dissipate heat at high temperatures,while at low temperatures,it can slow down the heat dissipation rate and prevent the human from becoming too cold.In addition,the fabric has UV shielding and photodynamic antibacterial properties through depositing graphitic carbon nitride nanosheets on the hydrophilic side.This smart fabric offers an innovative approach to maximizing personal comfort in environments with significant temperature variations.展开更多
Organic ultraviolet(UV)filters play a crucial role in reducing sunburn,photoaging,and the risk of skin cancer induced by UV radiation.However,the challenges posed by photodegradation,potential phototoxicity,and poor d...Organic ultraviolet(UV)filters play a crucial role in reducing sunburn,photoaging,and the risk of skin cancer induced by UV radiation.However,the challenges posed by photodegradation,potential phototoxicity,and poor dispersion characteristics of organic UV filters significantly hinder their practical applications.This study aims to encapsulate avobenzone,a widely used UV filter,in mesoporous silica(MPS)to form AB@MPS particles via an in-situ sol-gel process,and to research their sunscreen performance as stabilizers in Pickering emulsion.The UV absorption capability of AB@MPS particles is stronger than free avobenzone.The in vitro skin penetration study reveals a greatly reduced permeability(73.9%)for avobenzone from AB@MPS compared to its free form.Furthermore,the photostability of AB@MPS particles increases 14.3 times compared to that of free avobenzone.In UV protection tests,the Pickering emulsion’s anti-UVA efficacy is 2.28 times greater than that of 20%PG solution,4.41 times greater than Carbomer hydrogel,and 3.59 times greater than the cream formulation.The SPF value of the Pickering emulsion is 2.41 times greater than the 20%PG solution,2 times greater than the Carbomer hydrogel,and 6.77 times greater than the cream formulation.This study presents a promising strategy for the application of Pickering emulsions in the cosmetic and pharmaceutical sectors,providing a safe and efficient formulation for sunscreens.展开更多
Nanoparticles are increasingly used in chemical enhanced oil recovery(CEOR)due to their ability to improve oil recovery by altering reservoir rock and fluid properties.These nanoparticles,which have unique physical an...Nanoparticles are increasingly used in chemical enhanced oil recovery(CEOR)due to their ability to improve oil recovery by altering reservoir rock and fluid properties.These nanoparticles,which have unique physical and chemical traits,can be synthesized chemically or biologically.Biological synthesis,involving fungi,bacteria,algae,yeast,or plant materials are more stable,efficient,cost-effective,and environmentally friendly.With rising global energy demand and a shift towards greener solutions,the focus has moved from hazardous chemical synthesis to green synthesis for CEOR.Although some research exists on green nanoparticles for oil recovery,a comprehensive review of these studies and the mechanisms(such as wettability alteration,interfacial tension reduction,and stability enhancement)is needed.This paper reviews recent advances in the biosynthesis of nanoparticles and nanocomposites for oil recovery,highlighting successful examples like SiO_(2)/Montmorillonite/Xanthan and Fe3O4/SiO_(2)/Xanthan,which improved recovery by altering wettability,reducing interfacial tension,and enhancing dispersion and thermal stability.The study also notes the preference for plant-based green synthesis over microbial synthesis due to complexity and cost.The findings provide insights into the impact of novel greenly synthesized nanoparticles in CEOR.展开更多
In low-temperature environments,the condensation and icing phenomena of water molecules on material sur-faces may adversely affect the functionality and durability of various products,so it is critical to improve the ...In low-temperature environments,the condensation and icing phenomena of water molecules on material sur-faces may adversely affect the functionality and durability of various products,so it is critical to improve the antiicing properties of material surfaces.In this study,the anti-icing mechanism of superhydrophobic coatings was analyzed based on the surface wettability theory,and SiO_(2)/PDMS/EP superhydrophobic coating was fabricated by the spraying method.The surface wettability,surface micro-morphology,and surface chemical composition of the coating was characterized,and the stability of the coating as well as the anti-icing properties were investi-gated.The results show that the SiO_(2)/PDMS/EP superhydrophobic coating sprayed on the Al-based surface has a contact angle of 163.3° and a sliding angle of 4°,and the coating maintains excellent superhydrophobicity at a low temperature of-15°.This coating can significantly delay the freezing time and temperature of droplets on its surface,reduce the shear force and natural deicing time required to remove surface ice,and exhibit excellent anti-icing performance.The excellent anti-icing durability of the coating was demonstrated by the icing-deicing cycle experiment.Subsequently,the anti-frosting performance was further investigated,and the results showed that it effectively slowed down the speed of frost formation.Therefore,the superhydrophobic coating fabricated in this study is suitable for a wide range of working conditions and has potential practicality.It also provides experimental guidance for the application of anti-icing coatings on Al surfaces.展开更多
The vacuum reactive wetting and brazing of Er_(2)Si_(2)O_(7)/MoSi_(2) coatings were investigated using a (CoFeNiCrMn)_(88)Nb_(12) high-entropy alloy (HEA) brazing filler. The microstructural evolution and wettability ...The vacuum reactive wetting and brazing of Er_(2)Si_(2)O_(7)/MoSi_(2) coatings were investigated using a (CoFeNiCrMn)_(88)Nb_(12) high-entropy alloy (HEA) brazing filler. The microstructural evolution and wettability of the HEA filler were analyzed, with particular attention to the surface energy, interfacial stability, and electronic properties of the HEA filler/rare earth silicate coating system, as determined by density functional theory (DFT). As Nb diffused into the interface and the ErNbO_(4) phase formed, the wetting angle gradually decreased to 23.12° The effective wetting and spreading of the HEA brazing filler on the rare earth silicate coating surface are strongly correlated with the formation of the ErNbO_(4) phase at the interface. Furthermore, DFT calculations reveal that the interfacial bonding energy between the BCC' and FCC' phases and the ErNbO_(4) phase, after the wetting reaction, is significantly higher than the bonding energy between the initial filler and Er_(2)Si_(2)O_(7). This finding suggests that the formation of the ErNbO_(4) phase improves the wetting and spreading behavior of the filler.展开更多
Control of the wetting properties of biomimetic functional surfaces is a desired functionality in many applications.In this paper,the photoresist SU-8 was used as fabrication material.A silicon wafer was used as a sub...Control of the wetting properties of biomimetic functional surfaces is a desired functionality in many applications.In this paper,the photoresist SU-8 was used as fabrication material.A silicon wafer was used as a substrate to prepare a biomimetic surface with different surface roughness and micro-pillars arranged in array morphology.The evaporation dynamics and interfacial heat transfer processes of deionised water droplets on the bioinspired microstructure surface were experimentally studied.The study not only proves the feasibility of preparing hydrophilic biomimetic functional surfaces directly through photoresist materials and photolithography technology but also shows that by adjusting the structural parameters and arrangement of the surface micro-pillar structure,the wettability of the biomimetic surface can be significantly linearly regulated,thereby effectively affecting the heat and mass transfer process at the droplet liquid-vapour interface.Analysis of the results shows that by controlling the biomimetic surface microstructure,the wettability can be enhanced by about 22%at most,the uniformity of the temperature distribution at the liquid-vapour interface can be improved by about 34%,and the average evaporation rate can be increased by about 28%.This study aims to provide some guidance for the research on bionic surface design based on photoresist materials.展开更多
Purpose–This study examines the effect of increased surface energy on adhesion strength.Surface modifications were made using chemical coating methods such as primer paint(primer)and cataphoresis(KTL,Kathodische Tauc...Purpose–This study examines the effect of increased surface energy on adhesion strength.Surface modifications were made using chemical coating methods such as primer paint(primer)and cataphoresis(KTL,Kathodische Tauchlackierung).The wetting behaviour of adhesive on these surfaces and the resulting contact angles were analysed to evaluate bonding effectiveness.Design/methodology/approach–Primer paint was applied to glass fibre reinforced plastic(GFRP)materials and cataphoresis coating was applied to steel.Contact angles of the coated surfaces were measured and compared to those of the uncoated(natural)surfaces.Findings–Results showed that applying primer to GFRP and KTL to steel increased their surface energy compared to untreated surfaces.A decrease in contact angle correlated with improved wetting,suggesting enhanced adhesion potential.Originality/value–While the effects of surface coatings on adhesion have been studied,there is limited research specifically on the adhesion-enhancing potential of KTL coatings.Typically used for corrosion resistance,KTL is shown here to also improve adhesion.The novelty lies in experimentally demonstrating KTL’s dual role as both a protective and adhesion-enhancing layer.展开更多
The contact between contaminant and washing solution is a fundamental factor that limits the contaminant removal efficiency of chemical washing.In this study,the magnetization technique was employed to improve the phy...The contact between contaminant and washing solution is a fundamental factor that limits the contaminant removal efficiency of chemical washing.In this study,the magnetization technique was employed to improve the physicochemical properties of ethylene diamine tetraacetic acid(EDTA)solutions for the removal of lead(Pb)and cadmium(Cd)from a contaminated clayey soil.Furthermore,EDTA concentration,magnetization strength,and magnetization time were varied as parameters for enhancing the contact between contaminant and washing solution to improve remediation efficiency.The results showed that after magnetization,the viscosities,surface tensions,and contact angles of EDTA solutions decreased,whereas the electrical conductivity and pH increased.In particular,the viscosities of high-concentration EDTA solutions increased with increasing magnetic field strength and magnetization time.The magnetized EDTA solutions increased the maximum removal rates of Cd and Pb by 64.46% and 35.49%,respectively,compared to the unmagnetized EDTA solutions.The results highlighted the efficient metal removal by magnetized washing solutions due to the better contact between the washing solutions and the contaminants.The magnetic-enhanced soil washing method was proven to be efficient,cost-effective,and easily implementable for enhancing heavy metal removal.This study provides a valuable reference for improving the efficiency of chemical washing for heavy metal-contaminated clayey soils.展开更多
Recently, deep eutectic solvents (DES) have received great attention in assisting water flooding and surfactant flooding to improve oil recovery because they can reduce the interfacial tension (IFT) between oil and wa...Recently, deep eutectic solvents (DES) have received great attention in assisting water flooding and surfactant flooding to improve oil recovery because they can reduce the interfacial tension (IFT) between oil and water, inhibit surfactant adsorption, and change the wettability of rock. However, the effects of DES on the wettability of rock surface have not been thoroughly investigated in the reported studies. In this study, the effects of various DES samples on the wettability of sandstone samples are investigated using the Amott wettability measurement method. Three DES samples and several DES solutions and DES-surfactant solutions are firstly synthesized. Then, the wettability of the sandstone samples is measured using pure saline water, DES solutions, and DES-surfactant solutions, respectively. The effects of the DES samples on the wettability of the sandstone samples are investigated by comparing the measured wettability parameters, including oil displacement ratio (I_(o)), water displacement ratio (I_(w)), and wettability index (I_(A)). The Berea rock sample used in this study is weakly hydrophilic with I_(o), I_(w), and I_(A) of 0.318, 0.032, and 0.286, respectively. Being processed by the prepared DES samples, the wettability of the Berea sandstone samples is altered to hydrophilic (0.7 > I_(A) > 0.3) by increasing I_(w) but lowering Io. Similarly, DES-surfactant solutions can also modify the wettability of the Berea sandstone samples from weakly hydrophilic to hydrophilic. However, some DES-surfactant solutions can not only increase I_(w) but also increase I_(o), suggesting that the lipophilicity of those sandstone samples will be improved by the DES-surfactant solutions. In addition, micromodel flooding tests confirm the promising performance of a DES-surfactant solution in improving oil recovery and altering wettability. Moreover, the possible mechanisms of DES and DES-surfactant solutions in altering the wettability of the Berea sandstone samples are proposed. DES samples may improve the hydrophilicity by forming hydrogen bonds between rock surface and water molecules. For DES-surfactant solutions, surfactant micelles can capture oil molecules to improve the lipophilicity of those sandstone samples.展开更多
Accurately characterizing the wettability of solid surfaces is essential for various applications.Numerous factors,such as operating conditions and the features of the sample surface,affect wettability.In subsurface a...Accurately characterizing the wettability of solid surfaces is essential for various applications.Numerous factors,such as operating conditions and the features of the sample surface,affect wettability.In subsurface applications,precise wettability characterization of rock/fluid systems is particularly important because it determines fluid distribution and multiphase flow within porous media.Despite operating under similar conditions,significant variations are observed in the reported wettability of specific rock/fluid systems.Factors contributing to these inconsistencies include surface roughness and surface cleavage,which are often overlooked in contact angle measurements.Therefore,this study examines the impact of surface roughness and cleavage planes on freshly cleaved surfaces in comparison to surfaces exposed to the atmosphere.Pure calcite and clean quartz surfaces were selected in this study.For the surface cleavage effect,both macro and micro contact angles have been utilized,coupled with advanced image analysis to visualize the wettability changes as a function of scale.Furthermore,Fourier Transform Infrared(FTIR)spectroscopy is utilized to determine surface functional groups responsible for wettability variation due to atmospheric contaminants.Findings suggest that freshly cleaved surfaces exhibit greater hydrophilicity than their exposed counterparts,underscoring the necessity for caution when dealing with calcite and quartz due to the pivotal role of exposure time in determining wettability.Surface roughness measurements have been conducted to examine the impact of exposure time on surface topography and the results confirm that the change in surface roughness was negligible.The findings from this study enhance comprehension of the mechanisms at thenano-to milli-metre scale responsible for wettability variations.Also,a scientific understanding of the mechanisms responsible for wetting characteristics is established,which can be beneficial in addressing the discrepancies in the observed wetting behaviour.展开更多
Smart windows(SWs)garner significant potential in green buildings owing to their capability of on-demand tuning the solar gains.Apart from solar regulation,people always desire a type of slippery SW which can repel th...Smart windows(SWs)garner significant potential in green buildings owing to their capability of on-demand tuning the solar gains.Apart from solar regulation,people always desire a type of slippery SW which can repel the surface hydrous contaminants for anti-fouling application.Unfortunately,the up-to-date slippery SWs that respond to electrical/thermal stimuli have drawbacks of inferior durability and high energy-consumption,which greatly constrain their practical usability.This article presents our current work on an ultra-robust and energy-efficient near-infrared-responsive smart window(NIR-SW)which can regulate the optical transmittance and droplet’s adhesion in synergy.Significantly,laser-printing strategy enables us to seed the shape-memory photothermal microwalls on a transparent substrate,which can promote daylighting while maintaining privacy by near-infrared(NIR)switching between being transparent and opaque.As a light manipulator,it turns transparent with NIR-activated erect microwalls like an open louver;however,it turns opaque with the pressure-fixed bent microwalls akin to a closed louver.Simultaneously,the droplets can easily slip on the surface of erect microwalls similar to a classical lotus effect;by contrast,the droplets will tightly pin on the surface of bent microwalls analogous to the prevalent rose effect.Owing to shape-memory effect,this optical/wettability regulation is thus reversible and reconfigurable in response to the alternate NIR/pressure trigger.Moreover,NIR-SW unfolds a superior longevity despite suffering from the raindrop’s impacting more than 10000 cycles.Remarkably,such a new-type SW is competent for thermal management,anti-icing system,peep-proof screen,and programmable optics.This work renders impetus for the researchers striving for self-cleaning intelligent windows,energy-efficient greenhouse,and so forth.展开更多
基金the National Natural Science Foundation of China (No. 51065009)the Science Fund Project of Jiangxi Provincial Department of Education (No. GJJ11095)
文摘The natural hydrophobicity of surfaces can be enhanced if they are microtextured due to air trapped in the structure, which provides the deposited drop with a composite surface made of solid and air on which it is rest. Here, a series of grating microstructure surfaces with different parameters have been designed and fabricated by a novel soft lithography. The water contact angles （WCA） on these rough surfaces are measured through optical contact angle meter. The results indicate that all the WCA on the surfaces with grating microstructures are up to 150~; WCA increases and the hydrophobic performance also enhances with the decrease of the ridge width under the other fixed parameter condition; Experimental data obtained basically consists with the Cassie＇s theoretical prediction. The effects of geometric parameters of the microstructures on wettability of the grating sufaces are investigated.
基金supported by the National Key Research and Development Program of China(2020YFA0908200)the National Natural Science Foundation of China(T2225003,52073060 and 61927805)+1 种基金Guangdong Basic and Applied Basic Research Foundation(2021B1515120054)Shenzhen Science and Technology Program(JCYj20210324133214038).
文摘Fibers have been of great significance in our daily lives,especially in the industrial production of masks.Research in this area has been focused on developing microfibers with superior functions to enhance the filtration performances of the masks.Herein,inspired by the frog’s predation mechanism using its tongues to swiftly grab flying insects,we propose novel porous wettable microfibers from microfluidics to efficiently capture particles in the air for filtration.Upon pre-dispersing LP emulsions into polyurethane(PU),porous microfibers dispersed with oil droplets could be continuously spun from a co-flow microfluidic device based on the quick phase inversion of PU.To design an optimal system with frog-tongue-like interfacial adhesion properties,the wettability performances of the porous microfibers are investigated under full,partial,and no oil coverage conditions.When implemented in a mask,the 3D patterned networks based on the frog-tongue-inspired microfibers have been proven with remarkable particle capture performances while maintaining good air permeability.Based on these features,we believe that frog-tongue-inspired microfibers and their derived masks are of practical significance in multiple applications.
基金the Scientific and Technological Research Council of Türkiye(TÜBiTAK).
文摘This study investigated surface roughness,the wettability behavior,and surface energy of Co-based alloy specimens textured using the biomimetic Laser Surface Texturing(LST)method.The surface texture was inspired by the patterns found on marine shells.The impacts of the parameters on wettability,Surface Free Energy(SFE),surface topography,and texture roughness generated by the laser beam tracking a spiral path were investigated.Reducing spiral pitch produces more complicated and chaotic surface patterns.Most surfaces are hydrophobic,and surface roughness and topography influence the Contact Angle(CA).Topography and roughness were affected by frequency and scanning speed;a decrease in scanning speed and frequency generated more chaotic and irregular surface textures.With general factorial analysis and Analysis of Variance(ANOVA),our statistical study reveals that accounting for 88%of the influence,the scanning speed is the primary factor influencing surface roughness.On the other hand,the spiral pitch is essential for defining the struc-tural features of the surface,even if it less influences roughness.The SFE of laser-textured CoCr28Mo alloy specimens was optimizable within the range of 14-32 mN/m.The relevant findings offer valuable insights into optimizing LST for the specific surface properties of the Co-based alloy.
文摘In Chin.Phys.B 34114704(2025),Eq.(7)and the associated unit notation were incorrect.The correct ones are present here.Since Eq.(7)is an in-built expression in the simulation package,the correction is purely typographical and does not affect the simulation procedure,numerical results,or the conclusions.
基金supported by the National Natural Science Foundation of China (No. 52374292)China Baowu Low Carbon Metallurgy Innovation Foundation, China (No. BWLCF202309)the Natural Science Foundation of Changsha City, China (No. KQ2208271)。
文摘Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.
基金financially supported by the National Science Fund for Distinguished Young Scholars(22125201)and the National Natural ScienceFoundation of China(22105013,21872002).
文摘Unidirectional liquid transport(UDLT)has been widely used in various fields as an important process for transferring both mass and energy.However,UDLT driven by a structural gradient has been witnessed for a long time only in wettable liquids.For nonwettable liquids,UDLT can hardly proceed merely by a structural gradient.Herein,we propose an asymmetrically concave structured surface(AMC-surface),featuring tip-to-base periodically arranged pyramid-shaped concave structures with a certain degree of overlap,which enables the UDLT of both wettable and nonwettable liquids.For wettable liquids,the capillary force along each corner leads to the UDLT pointing toward the base side of the concave pyramid,while for nonwettable liquids,the UDLT is attributable to the static liquid pressure overwhelming the repulsive Laplace pressure induced by the asymmetric grooves and overlapping part.As a result,both wettable and nonwettable liquids transport spontaneously and unidirectionally on the AMC-surface with no energy input.Moreover,the concave structure endows good mechanical stability and can be easily prepared using a facile nail-punching approach over a large area.We also demonstrated its application in a continuous chemical reaction in a confined area.We envision that the unique UDLT behavior on the as-developed AMC-surface will shed new light on the programmable manipulation of various liquids.
文摘In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypropylene(PO)and oxyethylene(EO),octadecyl-(PO)_(m)-(EO)_(n)-sodium carboxylate(C_(18)PO_(m)EO_(n)C,m=5,10,15,n=5,10,15),were studied.The surface tension and contact angle of C_(18)PO_(m)EO_(n)C solution with different concentrations were measured,and the adhesion tension,PTFE-water interfacial tension,and adhesion work were calculated.It was found that the extended surfactant molecules adsorb on the surface of the solution and the PTFE-liquid interface simultaneously when the concentration is lower than the critical micelle concentration(cmc),and there was a linear relationship between surface tension and adhesion tension.The adsorption amount of C_(18)PO_(m)EO_(n)C at the PTFE-water interface was significantly lower than that on the surface of the solution.As the concentration increases above cmc,semi-micelle aggregates on the surface of PTFE are formed by C_(18)PO_(m)EO_(n)C molecules through hydrophobic interaction,and the hydrophilic group faces the solution to modify the surface of PTFE with high efficiency.
基金support from the National Natural:Science Foundation of China(NO.52174014)the National Natural Science Foundation Basic Science Center(NO.52288101).
文摘Oil-based drilling fluids possess excellent properties such as shale inhibition, cuttings suspension, and superior lubrication, making them essential in the development of unconventional oil and gas reservoirs.However, wellbore instability, caused by the invasion of drilling fluids into shale formations, remains a significant challenge for the safe and efficient extraction of shale oil and gas. This work reports the preparation of mesoporous SiO2nanoparticles with low surface energy, utilized as multifunctional agents to enhance the performance of oil-based drilling fluids aimed at improving wellbore stability. The results indicate that the coating prepared from these nanoparticles exhibit excellent hydrophobicity and antifouling properties, increasing the water contact angle from 32°to 146°and oil contact angle from 24°to134.8°. Additionally, these nanoparticles exhibit exceptional chemical stability and thermal resistance.Incorporating these nanoparticles into oil-based drilling fluids reduced the surface energy of the mud cake from 34.99 to 8.17 m J·m-2and increased the roughness of shale from 0.26 to 2.39 μm. These modifications rendered the mud cake and shale surfaces amphiphobic, effectively mitigating capillary infiltration and delaying the long-term strength degradation of shale in oil-based drilling fluids. After 28days of immersion in oil-based drilling fluid, shale cores treated with MF-SiO2exhibited a 30.5% increase in compressive strength compared to untreated cores. Additionally, these nanoparticles demonstrated the ability to penetrate and seal rock pores, reducing the API filtration volume of the drilling fluid from11.2 to 7.6 m L. This study introduces a novel approach to enhance the development of shale gas and oil resources, offering a promising strategy for wellbore stabilization in oil-based drilling fluid systems.
基金National Key R&D Program of China(2023YFA1507902,2021YFA1500804)the National Natural Science Foundation of China(22121004,22038009,22250008)+2 种基金the Haihe Laboratory of Sustainable Chemical Transformations(CYZC202107)the Program of Introducing Talents of Discipline to Universities,China(No.BP0618007)the Xplorer Prize,China,for their financial support。
文摘CO_(2)reduction reaction(CO_(2)RR)electrolyzers based on gas diffusion electrode(GDE)enable the direct mass transfer of CO_(2)to the catalyst surface for participation in the reaction,thereby establishing an efficient three-phase reaction interface that significantly enhances current density.However,current hydrophobic modification methods face difficulties in achieving precise and substantial control over wettability,and the hydrophobic modifiers tend to significantly impair the conductivity of the electrode and ion transport capabilities.This study employs Nafion ionomers to hydrophobically modify the threedimensional catalyst layer,revealing the bifunctionality of Nafion.The fluorinated backbone of Nafion ensures the hydrophobicity of the entire catalyst layer,while its sulfonic acid groups promote ion transport,without significantly affecting the conductivity of the electrode.Furthermore,by employing modifiers with distinct wettability characteristics,a highly efficient and large-scale manipulation of the hydrophilic/hydrophobic properties of the catalyst layer was successfully realized.The electrode,constructed with silver nanopowder as a representative catalyst and modified with the hydrophobic ionomer Nafion,exhibits a substantial enhancement in both catalytic activity and durability.The optimized electrode exhibited exceptional electrocatalytic performance in both flow cell and membrane electrode assembly(MEA)configurations.Notably,in the MEA,the electrode achieved a remarkable CO Faradaic efficiency(FE)of 93.3%at a total current density of 200 mA cm^(-2),while maintaining stable operation for over 62 h.
基金support of this work by National Key Research and Development Program of China(2019YFC19059003)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(23KJB430024)+1 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent(2023ZB680)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)are gratefully acknowledged.
文摘The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human comfort.However,the development of smart and dynamic fabrics capable of managing personal moisture/thermal comfort in response to changing external environments remains a challenge.Herein,a smart cellulose-based Janus fabric was designed to dynamically manage personal moisture/heat.The cotton fabric was grafted with N-isopropylacrylamide to construct a temperature-stimulated transport channel.Subsequently,hydrophobic ethyl cellulose and hydrophilic cellulose nanofiber were sprayed on the bottom and top sides of the fabric to obtain wettability gradient.The fabric exhibits anti-gravity directional liquid transportation from hydrophobic side to hydrophilic side,and can dynamically and continuously control the transportation time in a wide range of 3–66 s as the temperature increases from 10 to 40℃.This smart fabric can quickly dissipate heat at high temperatures,while at low temperatures,it can slow down the heat dissipation rate and prevent the human from becoming too cold.In addition,the fabric has UV shielding and photodynamic antibacterial properties through depositing graphitic carbon nitride nanosheets on the hydrophilic side.This smart fabric offers an innovative approach to maximizing personal comfort in environments with significant temperature variations.
文摘Organic ultraviolet(UV)filters play a crucial role in reducing sunburn,photoaging,and the risk of skin cancer induced by UV radiation.However,the challenges posed by photodegradation,potential phototoxicity,and poor dispersion characteristics of organic UV filters significantly hinder their practical applications.This study aims to encapsulate avobenzone,a widely used UV filter,in mesoporous silica(MPS)to form AB@MPS particles via an in-situ sol-gel process,and to research their sunscreen performance as stabilizers in Pickering emulsion.The UV absorption capability of AB@MPS particles is stronger than free avobenzone.The in vitro skin penetration study reveals a greatly reduced permeability(73.9%)for avobenzone from AB@MPS compared to its free form.Furthermore,the photostability of AB@MPS particles increases 14.3 times compared to that of free avobenzone.In UV protection tests,the Pickering emulsion’s anti-UVA efficacy is 2.28 times greater than that of 20%PG solution,4.41 times greater than Carbomer hydrogel,and 3.59 times greater than the cream formulation.The SPF value of the Pickering emulsion is 2.41 times greater than the 20%PG solution,2 times greater than the Carbomer hydrogel,and 6.77 times greater than the cream formulation.This study presents a promising strategy for the application of Pickering emulsions in the cosmetic and pharmaceutical sectors,providing a safe and efficient formulation for sunscreens.
基金funded by the Partnership for Skill in Applied Science,Engineering,and Technology(PASET)under the Regional Scholarship Innovation Fund(RSIF).
文摘Nanoparticles are increasingly used in chemical enhanced oil recovery(CEOR)due to their ability to improve oil recovery by altering reservoir rock and fluid properties.These nanoparticles,which have unique physical and chemical traits,can be synthesized chemically or biologically.Biological synthesis,involving fungi,bacteria,algae,yeast,or plant materials are more stable,efficient,cost-effective,and environmentally friendly.With rising global energy demand and a shift towards greener solutions,the focus has moved from hazardous chemical synthesis to green synthesis for CEOR.Although some research exists on green nanoparticles for oil recovery,a comprehensive review of these studies and the mechanisms(such as wettability alteration,interfacial tension reduction,and stability enhancement)is needed.This paper reviews recent advances in the biosynthesis of nanoparticles and nanocomposites for oil recovery,highlighting successful examples like SiO_(2)/Montmorillonite/Xanthan and Fe3O4/SiO_(2)/Xanthan,which improved recovery by altering wettability,reducing interfacial tension,and enhancing dispersion and thermal stability.The study also notes the preference for plant-based green synthesis over microbial synthesis due to complexity and cost.The findings provide insights into the impact of novel greenly synthesized nanoparticles in CEOR.
基金supported by the National Key R&D Program of China(2022YFB3403304)the National Natural Science Foundation of China(NSFC,Grant No.52275420,U23A20632)the Natural Science Foundation of Hunan Province[Grant No.2022JJ30136].
文摘In low-temperature environments,the condensation and icing phenomena of water molecules on material sur-faces may adversely affect the functionality and durability of various products,so it is critical to improve the antiicing properties of material surfaces.In this study,the anti-icing mechanism of superhydrophobic coatings was analyzed based on the surface wettability theory,and SiO_(2)/PDMS/EP superhydrophobic coating was fabricated by the spraying method.The surface wettability,surface micro-morphology,and surface chemical composition of the coating was characterized,and the stability of the coating as well as the anti-icing properties were investi-gated.The results show that the SiO_(2)/PDMS/EP superhydrophobic coating sprayed on the Al-based surface has a contact angle of 163.3° and a sliding angle of 4°,and the coating maintains excellent superhydrophobicity at a low temperature of-15°.This coating can significantly delay the freezing time and temperature of droplets on its surface,reduce the shear force and natural deicing time required to remove surface ice,and exhibit excellent anti-icing performance.The excellent anti-icing durability of the coating was demonstrated by the icing-deicing cycle experiment.Subsequently,the anti-frosting performance was further investigated,and the results showed that it effectively slowed down the speed of frost formation.Therefore,the superhydrophobic coating fabricated in this study is suitable for a wide range of working conditions and has potential practicality.It also provides experimental guidance for the application of anti-icing coatings on Al surfaces.
基金support from the National Natural Science Foundation of China(No.52374402)the National Key Research and Development Program(No.2022YFB3402200)+2 种基金the National Science and Technology Major Project(No.J2022-VII-0003-0045)the Project of Key areas of innovation team in Shaanxi Province(No.2024RS-CXTD-20)the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX2024055).
文摘The vacuum reactive wetting and brazing of Er_(2)Si_(2)O_(7)/MoSi_(2) coatings were investigated using a (CoFeNiCrMn)_(88)Nb_(12) high-entropy alloy (HEA) brazing filler. The microstructural evolution and wettability of the HEA filler were analyzed, with particular attention to the surface energy, interfacial stability, and electronic properties of the HEA filler/rare earth silicate coating system, as determined by density functional theory (DFT). As Nb diffused into the interface and the ErNbO_(4) phase formed, the wetting angle gradually decreased to 23.12° The effective wetting and spreading of the HEA brazing filler on the rare earth silicate coating surface are strongly correlated with the formation of the ErNbO_(4) phase at the interface. Furthermore, DFT calculations reveal that the interfacial bonding energy between the BCC' and FCC' phases and the ErNbO_(4) phase, after the wetting reaction, is significantly higher than the bonding energy between the initial filler and Er_(2)Si_(2)O_(7). This finding suggests that the formation of the ErNbO_(4) phase improves the wetting and spreading behavior of the filler.
基金supported by H2020-MSCA-RISE-778104–ThermaSMART,Royal Society(IEC\NSFC\211210)doctoral degree scholarship of China Scholarship Council(CSC).
文摘Control of the wetting properties of biomimetic functional surfaces is a desired functionality in many applications.In this paper,the photoresist SU-8 was used as fabrication material.A silicon wafer was used as a substrate to prepare a biomimetic surface with different surface roughness and micro-pillars arranged in array morphology.The evaporation dynamics and interfacial heat transfer processes of deionised water droplets on the bioinspired microstructure surface were experimentally studied.The study not only proves the feasibility of preparing hydrophilic biomimetic functional surfaces directly through photoresist materials and photolithography technology but also shows that by adjusting the structural parameters and arrangement of the surface micro-pillar structure,the wettability of the biomimetic surface can be significantly linearly regulated,thereby effectively affecting the heat and mass transfer process at the droplet liquid-vapour interface.Analysis of the results shows that by controlling the biomimetic surface microstructure,the wettability can be enhanced by about 22%at most,the uniformity of the temperature distribution at the liquid-vapour interface can be improved by about 34%,and the average evaporation rate can be increased by about 28%.This study aims to provide some guidance for the research on bionic surface design based on photoresist materials.
基金supported by the Sakarya University of Applied Sciences-Scientific Research Projects Coordination in the scope of master’s thesis Project under project number 285–2025.
文摘Purpose–This study examines the effect of increased surface energy on adhesion strength.Surface modifications were made using chemical coating methods such as primer paint(primer)and cataphoresis(KTL,Kathodische Tauchlackierung).The wetting behaviour of adhesive on these surfaces and the resulting contact angles were analysed to evaluate bonding effectiveness.Design/methodology/approach–Primer paint was applied to glass fibre reinforced plastic(GFRP)materials and cataphoresis coating was applied to steel.Contact angles of the coated surfaces were measured and compared to those of the uncoated(natural)surfaces.Findings–Results showed that applying primer to GFRP and KTL to steel increased their surface energy compared to untreated surfaces.A decrease in contact angle correlated with improved wetting,suggesting enhanced adhesion potential.Originality/value–While the effects of surface coatings on adhesion have been studied,there is limited research specifically on the adhesion-enhancing potential of KTL coatings.Typically used for corrosion resistance,KTL is shown here to also improve adhesion.The novelty lies in experimentally demonstrating KTL’s dual role as both a protective and adhesion-enhancing layer.
基金the financial support from the National Natural Science Foundation of China(Nos.42471155,U2004181,and 41371092)partially supported by the Natural Science Foundation of Heilongjiang Province,China(No.LH2024D025)+2 种基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,China(No.SKLFSE201917)the Key Scientific and Technological Project of Henan Province,China(No.192102310503)the National Key Scientific and Technological Project of Henan Province Office of Education,China(No.14B170007)。
文摘The contact between contaminant and washing solution is a fundamental factor that limits the contaminant removal efficiency of chemical washing.In this study,the magnetization technique was employed to improve the physicochemical properties of ethylene diamine tetraacetic acid(EDTA)solutions for the removal of lead(Pb)and cadmium(Cd)from a contaminated clayey soil.Furthermore,EDTA concentration,magnetization strength,and magnetization time were varied as parameters for enhancing the contact between contaminant and washing solution to improve remediation efficiency.The results showed that after magnetization,the viscosities,surface tensions,and contact angles of EDTA solutions decreased,whereas the electrical conductivity and pH increased.In particular,the viscosities of high-concentration EDTA solutions increased with increasing magnetic field strength and magnetization time.The magnetized EDTA solutions increased the maximum removal rates of Cd and Pb by 64.46% and 35.49%,respectively,compared to the unmagnetized EDTA solutions.The results highlighted the efficient metal removal by magnetized washing solutions due to the better contact between the washing solutions and the contaminants.The magnetic-enhanced soil washing method was proven to be efficient,cost-effective,and easily implementable for enhancing heavy metal removal.This study provides a valuable reference for improving the efficiency of chemical washing for heavy metal-contaminated clayey soils.
基金supported by the Scientific Research and Technology Development Projects of PetroChina(2023ZZ22-02)the Local Efficient Reform and Development Funds for Personnel Training Projectsthe China Scholarship Council(CSC)via a Ph.D.Scholarship(No.202008510128).
文摘Recently, deep eutectic solvents (DES) have received great attention in assisting water flooding and surfactant flooding to improve oil recovery because they can reduce the interfacial tension (IFT) between oil and water, inhibit surfactant adsorption, and change the wettability of rock. However, the effects of DES on the wettability of rock surface have not been thoroughly investigated in the reported studies. In this study, the effects of various DES samples on the wettability of sandstone samples are investigated using the Amott wettability measurement method. Three DES samples and several DES solutions and DES-surfactant solutions are firstly synthesized. Then, the wettability of the sandstone samples is measured using pure saline water, DES solutions, and DES-surfactant solutions, respectively. The effects of the DES samples on the wettability of the sandstone samples are investigated by comparing the measured wettability parameters, including oil displacement ratio (I_(o)), water displacement ratio (I_(w)), and wettability index (I_(A)). The Berea rock sample used in this study is weakly hydrophilic with I_(o), I_(w), and I_(A) of 0.318, 0.032, and 0.286, respectively. Being processed by the prepared DES samples, the wettability of the Berea sandstone samples is altered to hydrophilic (0.7 > I_(A) > 0.3) by increasing I_(w) but lowering Io. Similarly, DES-surfactant solutions can also modify the wettability of the Berea sandstone samples from weakly hydrophilic to hydrophilic. However, some DES-surfactant solutions can not only increase I_(w) but also increase I_(o), suggesting that the lipophilicity of those sandstone samples will be improved by the DES-surfactant solutions. In addition, micromodel flooding tests confirm the promising performance of a DES-surfactant solution in improving oil recovery and altering wettability. Moreover, the possible mechanisms of DES and DES-surfactant solutions in altering the wettability of the Berea sandstone samples are proposed. DES samples may improve the hydrophilicity by forming hydrogen bonds between rock surface and water molecules. For DES-surfactant solutions, surfactant micelles can capture oil molecules to improve the lipophilicity of those sandstone samples.
文摘Accurately characterizing the wettability of solid surfaces is essential for various applications.Numerous factors,such as operating conditions and the features of the sample surface,affect wettability.In subsurface applications,precise wettability characterization of rock/fluid systems is particularly important because it determines fluid distribution and multiphase flow within porous media.Despite operating under similar conditions,significant variations are observed in the reported wettability of specific rock/fluid systems.Factors contributing to these inconsistencies include surface roughness and surface cleavage,which are often overlooked in contact angle measurements.Therefore,this study examines the impact of surface roughness and cleavage planes on freshly cleaved surfaces in comparison to surfaces exposed to the atmosphere.Pure calcite and clean quartz surfaces were selected in this study.For the surface cleavage effect,both macro and micro contact angles have been utilized,coupled with advanced image analysis to visualize the wettability changes as a function of scale.Furthermore,Fourier Transform Infrared(FTIR)spectroscopy is utilized to determine surface functional groups responsible for wettability variation due to atmospheric contaminants.Findings suggest that freshly cleaved surfaces exhibit greater hydrophilicity than their exposed counterparts,underscoring the necessity for caution when dealing with calcite and quartz due to the pivotal role of exposure time in determining wettability.Surface roughness measurements have been conducted to examine the impact of exposure time on surface topography and the results confirm that the change in surface roughness was negligible.The findings from this study enhance comprehension of the mechanisms at thenano-to milli-metre scale responsible for wettability variations.Also,a scientific understanding of the mechanisms responsible for wetting characteristics is established,which can be beneficial in addressing the discrepancies in the observed wetting behaviour.
基金supported by the National Natural Science Foundation of China(No.52005475,62305321)the Natural Science Foundation of Anhui Province(No.JZ2024AKZR0561,2308085QE167)Opening Project of the Key Laboratory of Bionic Engineering(Ministry of Education),Jilin University(K202204).
文摘Smart windows(SWs)garner significant potential in green buildings owing to their capability of on-demand tuning the solar gains.Apart from solar regulation,people always desire a type of slippery SW which can repel the surface hydrous contaminants for anti-fouling application.Unfortunately,the up-to-date slippery SWs that respond to electrical/thermal stimuli have drawbacks of inferior durability and high energy-consumption,which greatly constrain their practical usability.This article presents our current work on an ultra-robust and energy-efficient near-infrared-responsive smart window(NIR-SW)which can regulate the optical transmittance and droplet’s adhesion in synergy.Significantly,laser-printing strategy enables us to seed the shape-memory photothermal microwalls on a transparent substrate,which can promote daylighting while maintaining privacy by near-infrared(NIR)switching between being transparent and opaque.As a light manipulator,it turns transparent with NIR-activated erect microwalls like an open louver;however,it turns opaque with the pressure-fixed bent microwalls akin to a closed louver.Simultaneously,the droplets can easily slip on the surface of erect microwalls similar to a classical lotus effect;by contrast,the droplets will tightly pin on the surface of bent microwalls analogous to the prevalent rose effect.Owing to shape-memory effect,this optical/wettability regulation is thus reversible and reconfigurable in response to the alternate NIR/pressure trigger.Moreover,NIR-SW unfolds a superior longevity despite suffering from the raindrop’s impacting more than 10000 cycles.Remarkably,such a new-type SW is competent for thermal management,anti-icing system,peep-proof screen,and programmable optics.This work renders impetus for the researchers striving for self-cleaning intelligent windows,energy-efficient greenhouse,and so forth.
