Metal-based electrocatalysts with different sizes(single atoms,nanoclusters,and nanoparticles)show different catalytic behaviors for various electrocatalytic reactions.Regulating the coordination environment of active...Metal-based electrocatalysts with different sizes(single atoms,nanoclusters,and nanoparticles)show different catalytic behaviors for various electrocatalytic reactions.Regulating the coordination environment of active sites with precision to rationally design an efficient electrocatalyst is of great significance for boosting electrocatalytic reactions.This review summarizes the recent process of heterogeneous supported single atoms,nanoclusters,and nanoparticles catalysts in electrocatalytic reactions,respectively,and figures out the construct strategies and design concepts based on their strengths and weaknesses.Specifically,four key factors for enhancing electrocatalytic performance,including electronic structure,coordination environment,support property,and interfacial interactions are proposed to provide an overall comprehension to readers in this field.Finally,some insights into the current challenges and future opportunities of the heterogeneous supported electrocatalysts are provided.展开更多
The heterogeneous Fenton reaction can generate highly reactive hydroxyl radicals（·OH）from reactions between recyclable solid catalysts and H2O2 at acidic or even circumneutral pH.Hence,it can effectively oxidiz...The heterogeneous Fenton reaction can generate highly reactive hydroxyl radicals（·OH）from reactions between recyclable solid catalysts and H2O2 at acidic or even circumneutral pH.Hence,it can effectively oxidize refractory organics in water or soils and has become a promising environmentally friendly treatment technology.Due to the complex reaction system,the mechanism behind heterogeneous Fenton reactions remains unresolved but fascinating,and is crucial for understanding Fenton chemistry and the development and application of efficient heterogeneous Fenton technologies.Iron-based materials usually possess high catalytic activity,low cost,negligible toxicity and easy recovery,and are a superior type of heterogeneous Fenton catalysts.Therefore,this article reviews the fundamental but important interfacial mechanisms of heterogeneous Fenton reactions catalyzed by iron-based materials..OH,hydroperoxyl radicals/superoxide anions（HO2./O2^-.）and high-valent iron are the three main types of reactive oxygen species（ROS）,with different oxidation reactivity and selectivity.Based on the mechanisms of ROS generation,the interfacial mechanisms of heterogeneous Fenton systems can be classified as the homogeneous Fenton mechanism induced by surface-leached iron,the heterogeneous catalysis mechanism,and the heterogeneous reaction-induced homogeneous mechanism.Different heterogeneous Fenton systems catalyzed by characteristic iron-based materials are comprehensively reviewed.Finally,related future research directions are also suggested.展开更多
Nature is a huge gallery of art involving nearly perfect structures and properties over the millions of years of development. Many plants and animals show water-repellent properties with fine micro-structures, such as...Nature is a huge gallery of art involving nearly perfect structures and properties over the millions of years of development. Many plants and animals show water-repellent properties with fine micro-structures, such as lotus leaf, water skipper and wings of butterfly. Inspired by these special surfaces, the artificial superhydrophobic surfaces have attracted wide attention in both basic research and industrial applications. The wetting properties of superhydrophobic surfaces in nature are affected by the chemical compositions and the surface topographies. So it is possible to realize the biomimetic superhydrophobic surfaces by tuning their surface roughness and surface free energy correspondingly. This review briefly introduces the physical-chemical basis of superhydrophobic plant surfaces in nature to explain how the superhydrophobicity of plant surfaces can be applied to different biomimetic functional materials with relevance to technological applications. Then, three classical effects of natural surfaces are classified： lotus effect, salvinia effect, and petal effect, and the promising strategies to fabricate biomimetic su- perhydrophobic materials are highlighted. Finally, the prospects and challenges of this area in the future are proposed.展开更多
Anionic surfactant sodium dodecyl benzene sulfonate(SDBS)at varying concentrations was selected to investigate the influence on the wettability of Zhaozhuang Coal by molecular dynamics simulation.Six groups of water/s...Anionic surfactant sodium dodecyl benzene sulfonate(SDBS)at varying concentrations was selected to investigate the influence on the wettability of Zhaozhuang Coal by molecular dynamics simulation.Six groups of water/surfactant/coal systems with different concentrations were constructed.The influence of surfactant with different concentrations on the wettability of coal was concluded by analyzing various properties from the energetic behaviors to the dynamic characteristics.The results show that the interfacial tension decreases sharply and then rises slowly with the increase of SDBS surfactant concentration,obtaining that surfactants can obviously reduce the interfacial tension.The surfactant molecules could be detected at the water/coal interface through analyzing the system’s relative concentration distribution.In addition,the difference in the wettability of surfactants on coal surfaces is caused by the spatial distribution differences of alkyl chains and the benzene ring of the surfactant molecules.And the negative interaction energy between SDBS and the coal surface indicates that adsorption process is spontaneous.Furthermore,it is of great practical significance for improving the dust reduction effect and reducing the disaster of coal dust by exploring the effects of surfactant molecules on the wettability of coal.展开更多
The feasibility of using coral reef sand（CRS） in Portland cement concrete is investigated by testing the mechanical property and microstructure of concrete. The composition, structure and properties of the CRS are a...The feasibility of using coral reef sand（CRS） in Portland cement concrete is investigated by testing the mechanical property and microstructure of concrete. The composition, structure and properties of the CRS are analyzed. Mechanical properties and microstructure of concrete with CRS are studied and compared to concrete with natural river sand. The relationship between the microstructure and performance of CRS concrete is established. The CRS has a porous surface with high water intake capacity, which contributes to the mechanical properties of concrete. The interfacial transition zone between the cement paste and CRS is densified compared to normal concrete with river sand. Hydration products form in the pore space of CRS and interlock with the matrix of cement paste, which increases the strength. The total porosity of concrete prepared with CRS is higher than that with natural sand. The main difference in pore size distribution is the fraction of fine pores in the range of 100 nm.展开更多
Silicon carbide(SiC) has been widely concerned for its excellent overall mechanical and physical properties, such as low density, good thermal-shock behavior, high temperature oxidation resistance, and radiation resis...Silicon carbide(SiC) has been widely concerned for its excellent overall mechanical and physical properties, such as low density, good thermal-shock behavior, high temperature oxidation resistance, and radiation resistance; as a result, the SiC-based materials have been or are being widely used in most advanced fields involving aerospace, aviation, military, and nuclear power. Joining of SiC-based materials(monolithic SiC and SiCf/SiC composites) can resolve the problems on poor processing performance and difficulty of fabrication of large-sized and complex-shaped components to a certain extent, which are originated from their high inherent brittleness and low impact toughness.Starting from the introduction to SiC-based materials, joining of ceramics, and joint strength characterization, the joining of SiC-based materials is reviewed by classifying the as-received interlayer materials, involving no interlayer, metallic, glass-ceramic, and organic interlayers. In particular, joining processes(involving joining techniques and parameter conditions), joint strength,interfacial microstructures, and/or reaction products are highlighted for understanding interfacial behavior and for supporting development of application-oriented joining techniques.展开更多
Crystalline Fe/MnO@C core–shell nanocapsules inlaid in porous amorphous carbon matrix(FMCA)was synthesized successfully with a novel confinement strategy.The heterogeneous Fe/MnO nanocrystals are with approximate sin...Crystalline Fe/MnO@C core–shell nanocapsules inlaid in porous amorphous carbon matrix(FMCA)was synthesized successfully with a novel confinement strategy.The heterogeneous Fe/MnO nanocrystals are with approximate single-domain size which gives rise to natural resonance in 2–18 GHz.The addition of MnO2 confines degree of graphitization catalyzed by iron and contributes to the formation of amorphous carbon.The heterogeneous materials composed of crystalline–amorphous structures disperse evenly and its density is significantly reduced on account of porous properties.Meanwhile,adjustable dielectric loss is achieved by interrupting Fe core aggregation and stacking graphene conductive network.The dielectric loss synergistically with magnetic loss endows the FMCA enhanced absorption.The optimal reflection loss(RL)is up to−45 dB,and the effective bandwidth(RL<−10 dB)is 5.0 GHz with 2.0 mm thickness.The proposed confinement strategy not only lays the foundation for designing high-performance microwave absorber,but also offers a general duty synthesis method for heterogeneous crystalline–amorphous composites with tunable composition in other fields.展开更多
Lithium(Li)metal is considered as one of the most promising anode materials for next-generation high-energy-density storage systems.However,the practical application of Li metal anode is hindered by interfacial instab...Lithium(Li)metal is considered as one of the most promising anode materials for next-generation high-energy-density storage systems.However,the practical application of Li metal anode is hindered by interfacial instability and air instability due to the highly reactivity of Li metal.Unstable interface in Li metal batteries(LMBs)directly dictates Li dendrite growth,“dead Li”and low Coulombic efficiency,resulting in inferior electrochemical performance of LMBs and even safety issues.In addition,its sensitivity to ambient air leads to the severe corrosion of Li metal anode,high requirements of production and storage,and increased manufacturing cost.Plenty of efforts in recent years have overcome many bottlenecks in these fields and hastened the practical applications of high-energy-density LMBs.In this review,we focus on emerging methods of these two aspects to fulfill a stable and low cost electrode.In this perspective,design artificial solid electrolyte interphase(SEI)layers,construct three-dimensional conductive current collectors,optimize electrolytes,employ solid-state electrolytes,and modify separators are summarized to be propitious to ameliorate interfacial stability.Meanwhile,ex situ/in situ formed protective layers are highlighted in favor of heightening air stability.Finally,several possible directions for the future research on advanced Li metal anode are addressed.展开更多
Rapid development of energy,electrical and electronic technologies has put forward higher requirements for the thermal conductivities of polymers and their composites.However,the thermal conductivity coefficient(λ)va...Rapid development of energy,electrical and electronic technologies has put forward higher requirements for the thermal conductivities of polymers and their composites.However,the thermal conductivity coefficient(λ)values of prepared thermally conductive polymer composites are still difficult to achieve expectations,which has become the bottleneck in the fields of thermally conductive polymer composites.Aimed at that,based on the accumulation of the previous research works by related researchers and our research group,this paper proposes three possible directions for breaking through the bottlenecks:(1)preparing and synthesizing intrinsically thermally conductive polymers,(2)reducing the interfacial thermal resistance in thermally conductive polymer composites,and(3)establishing suitable thermal conduction models and studying inner thermal conduction mechanism to guide experimental optimization.Also,the future development trends of the three above-mentioned directions are foreseen,hoping to provide certain basis and guidance for the preparation,researches and development of thermally conductive polymers and their composites.展开更多
Lithium metal is considered the ideal anode material for Li-ion-based batteries because it exhibits the highest specific capacity and lowest redox potential for this type of cells. However, growth of Li dendrites, uns...Lithium metal is considered the ideal anode material for Li-ion-based batteries because it exhibits the highest specific capacity and lowest redox potential for this type of cells. However, growth of Li dendrites, unstable solid electrolyte interphases, low Coulombic efficiencies, and safety hazards have significantly hindered the practical application of metallic Li anodes. Herein, we propose a three-dimensional （3D） carbon nanotube sponge （CNTS） as a Li deposition host. The high specific surface area of the CNTS enables homogenous charge distribution for Li nucleation and minimizes the effective current density to overcome dendrite growth. An additional conformal A1203 layer on the CNTS coated by atomic layer deposition （ALD） robustly protects the Li metal electrode/electrolyte interface due to the good chemical stability and high mechanical strength of the layer. The Li@ALD-CNTS electrode exhibits stable voltage profiles with a small overpotential ranging from 16 to 30 mV over 100 h of cycling at 1.0 mA·cm^-2. Moreover, the electrodes display a dendrite-free morphology after cycling and a Coulombic efficiency of 92.4% over 80 cycles at 1.0 mA·cm^-2 in an organic carbonate electrolyte, thus demonstrating electrochemical stability superior to that of planar current collectors. Our results provide an important strategy for the rational design of current collectors to obtain stable Li metal anodes.展开更多
Nanoparticles have already gained attentions for their countless potential applications in enhanced oil recovery.Nano-sized particles would help to recover trapped oil by several mechanisms including interfacial tensi...Nanoparticles have already gained attentions for their countless potential applications in enhanced oil recovery.Nano-sized particles would help to recover trapped oil by several mechanisms including interfacial tension reduction, impulsive emulsion formation and wettability alteration of porous media. The presence of dispersed nanoparticles in injected fluids would enhance the recovery process through their movement towards oil–water interface. This would cause the interfacial tension to be reduced. In this research, the effects of different types of nanoparticles and different nanoparticle concentrations on EOR processes were investigated. Different flooding experiments were investigated to reveal enhancing oil recovery mechanisms. The results showed that nanoparticles have the ability to reduce the IFT as well as contact angle, making the solid surface to more water wet. As nanoparticle concentration increases more trapped oil was produced mainly due to wettability alteration to water wet and IFT reduction. However, pore blockage was also observed due to adsorption of nanoparticles, a phenomenon which caused the injection pressure to increase. Nonetheless, such higher injection pressure could displace some trapped oil in the small pore channels out of the model. The investigated results gave a clear indication that the EOR potential of nanoparticle fluid is significant.展开更多
To reduce friction drag with bionic method in a more feasible way, the surface microstructure of fish scales was analyzed attempting to reveal the biologic features responding to skin friction drag reduction. Then com...To reduce friction drag with bionic method in a more feasible way, the surface microstructure of fish scales was analyzed attempting to reveal the biologic features responding to skin friction drag reduction. Then comparable bionic surface mimicking fish scales was fabricated through coating technology for drag reduction. The paint mixture was coated on a substrate through a self-developed spray-painting apparatus. The bionic surface with micron-scale caves formed spontaneously due to the interra- cial convection and deformation driven by interfacial tension gradient in the presence of solvent evaporation. Comparative experiments between bionic surface and smooth surface were performed in a water tunnel to evaluate the effect of bionic surface on drag reduction, and visible drag reduction efficiency was obtained. Numerical simulation results show that gas phase de- velops in solid-liquid interface of bionic surface with the effect of surface topography and partially replaces the solid-liquid shear force with gas-liquid shear force, hence reducing the skin friction drag effectively. Therefore, with remarkable drag re- duction performance and simple fabrication technology, the proposed drag reduction technique shows the promise for practical applications.展开更多
Chemical enhanced oil recovery(EOR)and particularly surfactant injection has recently received a great deal of attention.The suggested recovery mechanisms after injecting surfactants include wettability alteration and...Chemical enhanced oil recovery(EOR)and particularly surfactant injection has recently received a great deal of attention.The suggested recovery mechanisms after injecting surfactants include wettability alteration and IFT reduction.If a surfactant is properly selected according to the environmental variables-such as pressure,temperature,salinity,it can lead to more efficient enhanced recovery from an oil reservoir.On the other hand,poor selection of the surfactant can result in a low recovery and can even become detrimental to the reservoir due to undesirable wettability alteration and possible rock dissolution resulting in a chemical reaction with displacing fluid and blockage of the pore space.Also,choosing the wrong surfactant without considering the rock mineralogy may result in high adsorption on the pore surface of the rock and unnecessary waste of resources.It is also worthy to note that surfactants are some of the most expensive chemicals used during EOR.Extensive literature review suggests that anionic surfactant are the preferred surfactant category for EOR especially when it comes to sandstone reservoirs.Occasionally,in specific situations a better performance have been reported after injecting cationic,non-ionic or mixtures of both surfactants,particularly when dealing with carbonate reservoirs.This paper presents in detail a review of the most commonly applied surfactants in EOR studies and the optimum application criteria for of each type.To the best of the authors'knowledge,such detailed and comprehensive review is not available in the literature,presently.展开更多
Molybdenum disulfide (MoS2) has been recognized as one of the most promising candidates to replace precious Pt for hydrogen evolution reaction (HER) catalysis, due to the natural abundance, low cost, tunable electroni...Molybdenum disulfide (MoS2) has been recognized as one of the most promising candidates to replace precious Pt for hydrogen evolution reaction (HER) catalysis, due to the natural abundance, low cost, tunable electronic properties, and excellent chemical stability. Although notable processes have been achieved in the past decades, their performance is still far less than that of Pt. Searching effective strategies to boosting their HER performance is still the primary goal. In this review, the recent process of the electronic regulation of MoS2 for HER is summarized, including band structure engineering, electronic state modulation, orbital orientation regulation, interface engineering. Last, the key challenges and opportunities in the development of MoS2-based materials for electrochemical HER are also discussed.展开更多
Safe,inexpensive aqueous zinc-ion batteries(AZIBs)are regarded as promising energy storage devices.However,they still face issues,including dissolution and collapse of the cathode as well as H_(2)evolution and the gro...Safe,inexpensive aqueous zinc-ion batteries(AZIBs)are regarded as promising energy storage devices.However,they still face issues,including dissolution and collapse of the cathode as well as H_(2)evolution and the growth of Zn dendrites on the Zn anode.Herein,we simultaneously regulate the cations and anions in the electrolyte for high-capacity,high-stability aqueous zinc–vanadium(Zn–V)batteries based on a bimetallic cation-doped Na_(0.33)K_(0.1)V_(2)O_(5)·nH_(2)O cathode.We demonstrate that Na^(+) cations suppress cathode dissolution and restrain Zn dendrite growth on the anode via an electrostatic shield effect.We also illustrate that ClO_(4)^(-) anions participate in energy storage at the cathode and are reduced to Cl^(-),generating a protective layer on the Zn anode surface and providing a stable interface to decrease Zn dendrites and H_(2)evolution during long-term cycling.When Na^(+) and ClO_(4)^(-) are introduced into an aqueous ZnSO_(4) electrolyte,a Zn/Zn symmetric cell shows durable and reversible Zn stripping/plating for 1500 h at a current density of 1 mA cm^(-2) and with an area capacity of 1 mAh cm^(-2).Zn/Na_(0.33)K_(0.1)V_(2)O_(5)·nH_(2)O full batteries exhibit a high capacity of 600 mAh g^(-1)at 0.1 A g^(-1) and long-term cycling performance for 5000 cycles,with a capacity of 200 mAh g^(-1) at 20 Ag^(-1).展开更多
Interfacial interactions involving Van der Waals force, hydrophobic attractive force and hydration exclusive force were investigated in this paper. The interfacial interactive free energy of a series of interfaces occ...Interfacial interactions involving Van der Waals force, hydrophobic attractive force and hydration exclusive force were investigated in this paper. The interfacial interactive free energy of a series of interfaces occurring between minerals, water, collectors and bubble was calculated. The results show that a Van der Waals attractive force and a hydrophobic attractive force exist between each mineral and water interface. The hydrophobic attractive force between molybdenite and water is markedly weaker than the hydrophobic attractive force between gangue and water. The hydrophobic attractive force between collector molecules and water is the main driving force that causes the collectors to become dispersed in the pulp. The strong hydrophobic attractive force between molybdenite and the bubble interface is the basic reason for the natural floatability of molybdenite. The Van der Waals force between molybdenite and the collectors is attractive in water solution, but it is not the cause of the main force between them. The main force that results in the collection effect is a hydrophobic attractive force caused by the Lewis acid-base interaction at the molybdenite surface. A floatation experiment shows that the adsorption intensity of the collector on the molybdenite surface is not the crucial factor for molybdenite floatation. Rather, the dispersing capability of the collector in the water phase and its selectivity for the various minerals in the floatation system are more important.展开更多
Developing electromagnetic(EM) wave absorbing materials with low reflection coefficient and optimal operating frequency band is urgently needed on account of the increasingly serious EM pollution. However, the applica...Developing electromagnetic(EM) wave absorbing materials with low reflection coefficient and optimal operating frequency band is urgently needed on account of the increasingly serious EM pollution. However, the applications of common EM absorbing materials are encumbered by poor high-temperature stability, poor oxidation resistance, narrow absorption bandwidth or high density. Herein, the strong EM absorption capability and wide efficient absorption bandwidth of high entropy ceramics are reported for the first time, which are designed by a combination of the novel high entropy(HE) rare earth silicide carbides/rare earth oxides(RE3 Si2 C2/RE2 O3). Three HE powders, i.e., HERSC-1(HE(Tm0.2 Y0.2 Dy0.2 Gd0.2 Tb0.2)3 Si2 C2),HERSC-2 HE(Tm0.2 Y0.2 Dy0.2 Gd0.2 Tb0.2)3 Si2 C2/HE(Tm0.2 Y0.2 Dy0.2 Gd0.2 Tb0.2)2 O3) and HERSC-3(HE(Tm0.2 Y0.2 Dy0.2 Gd0.2 Tb0.2)3 Si2 C2/HE(Tm0.2 Y0.2 Dy0.2 Gd0.2 Tb0.2)2 O3), are synthesized. Although HERSC-1 exhibits a limited absorption effect(the minimum reflection loss(RLmin) is-11.6 d B at 3.4 mm) and a relatively narrow effective absorption bandwidth(EAB) of 1.7 GHz, the optimal absorption RLminvalue and EAB of HERSC-2 and HERSC-3 are-40.7 d B(at 2.9 mm), 3.4 GHz and-50.9 d B(at 2.0 mm), 4.5 GHz,respectively, demonstrating strong microwave absorption capability and wide absorption bandwidth.Considering the better stability, low density and strong EM absorption effect, HE ceramics are promising as a new type of EM absorbing materials.展开更多
Nickel-based single-crystal superalloys are the key materials for the manufacturing and development of advanced aeroengines. Rhenium is a crucial alloying element in the advanced nickel-based single-crystal superalloy...Nickel-based single-crystal superalloys are the key materials for the manufacturing and development of advanced aeroengines. Rhenium is a crucial alloying element in the advanced nickel-based single-crystal superalloys for its special strengthening effects. The addition of Re could effectively enhance the creep properties of the single-crystal superalloys; thus, the content of Re is considered as one of the characteristics in different-generation single-crystal superalloys. Owing to the fundamental importance of rhenium to nickel-based single-crystal superalloys, much progress has been made on understanding of the effect of rhenium in the single-crystal superalloys. While the effect of Re doping on the nickelbased superalloys is well documented, the origins of the socalled rhenium effect are still under debate. In this paper,the effect of Re doping on the single-crystal superalloys and progress in understanding the rhenium effect are reviewed. The characteristics of the d-states occupancy in the electronic structure of Re make it the slowest diffusion elements in the single-crystal superalloys, which is undoubtedly responsible for the rhenium effect, while the postulates of Re cluster and the enrichment of Re at the c/c0 interface are still under debate, and the synergistic action of Re with other alloying elements should be further studied.Additionally, the interaction of Re with interfacial dislocations seems to be a promising explanation for the rhenium effect. Finally, the addition of Ru could help suppress topologically close-packed（TCP） phase formation and strengthen the Re doping single-crystal superalloys.Understanding the mechanism of rhenium effect will be beneficial for the effective utilization of Re and the design of low-cost single-crystal superalloys.展开更多
In this article, a new type of Cu-Ti3SiC2 composite powder prepared using the electroless plating technique was introduced. The initial Ti3SiC2 particles are 11 μm in diameter on an average. The Cu plating was carrie...In this article, a new type of Cu-Ti3SiC2 composite powder prepared using the electroless plating technique was introduced. The initial Ti3SiC2 particles are 11 μm in diameter on an average. The Cu plating was carried out at middle temperature （62-65℃） with the application of ultrasonic agitation. The copper deposition rate was determined by measuring the weight gain of the powder after plating. It has been found that the pretreatment of Ti3SiC2 powder is very important to obtain copper nanoparticles on the surface of Ti3SiC2 The optimum procedure before plating aimed to add activated sites and the adjustment of the traditional composition of the electroless copper plating bath could decelerate the copper deposition rate to 0.8 gm/h. X-ray diffraction （XRD） indicates that the chemical composition of the plating layer is copper. SEM images show that the surface of the Ti3SiC2 particles is successfully coated with continuous copper layer. The wetting property between the copper matrix and Ti3SiC2 can be improved so as to increase the interfacial strength.展开更多
The influences of an anionic-nonionic composite surfactant and petroleum sulfonate, used in surfactant-polymer flooding in Shengli Gudong oilfield, East China, on the interfacial properties of Gudong crude model oil a...The influences of an anionic-nonionic composite surfactant and petroleum sulfonate, used in surfactant-polymer flooding in Shengli Gudong oilfield, East China, on the interfacial properties of Gudong crude model oil and synthetic formation water was studied by measuring interfacial tension, interfacial viscoelasticity and Zeta potential. The in？ uence of the surfactants on the stability of Gudong water-in-oil （W/O） and oil-in-water （O/W） emulsions was evaluated by separating water from the W/O emulsion and residual oil in the aqueous phase of the O/W emulsion respectively. The results showed that the two kinds of surfactants, namely anionic-nonionic composite surfactant and petroleum sulfonate, are both able to decrease the interfacial tension between the oil phase and the aqueous phase and increase the surface potential of the oil droplets dispersed in the O/W emulsion, which can enhance the stability of the W/O and O/W crude oil emulsions. Compared with petroleum sulfonate, the anionic-nonionic composite surfactant is more interfacially active and able to enhance the strength of the interfacial film between oil and water, hence enhance the stability of the W/O and O/W emulsions more effectively.展开更多
基金the National Key R&D Program of China(No.2018YFA0702003)the National Natural Science Foundation of China(Nos.21890383 and 21871159)+1 种基金the science and Technology Key Project of Guangdong Province of China(No.2020B010188002)the China Postdoctoral Science Foundation(Nos.2021M691757,2021M690086,and 2021TQ0170).
文摘Metal-based electrocatalysts with different sizes(single atoms,nanoclusters,and nanoparticles)show different catalytic behaviors for various electrocatalytic reactions.Regulating the coordination environment of active sites with precision to rationally design an efficient electrocatalyst is of great significance for boosting electrocatalytic reactions.This review summarizes the recent process of heterogeneous supported single atoms,nanoclusters,and nanoparticles catalysts in electrocatalytic reactions,respectively,and figures out the construct strategies and design concepts based on their strengths and weaknesses.Specifically,four key factors for enhancing electrocatalytic performance,including electronic structure,coordination environment,support property,and interfacial interactions are proposed to provide an overall comprehension to readers in this field.Finally,some insights into the current challenges and future opportunities of the heterogeneous supported electrocatalysts are provided.
基金supported by the National Natural Science Foundation of China (Nos. 21107125, 21577160, 51221892, 51290282 and 41201498)
文摘The heterogeneous Fenton reaction can generate highly reactive hydroxyl radicals（·OH）from reactions between recyclable solid catalysts and H2O2 at acidic or even circumneutral pH.Hence,it can effectively oxidize refractory organics in water or soils and has become a promising environmentally friendly treatment technology.Due to the complex reaction system,the mechanism behind heterogeneous Fenton reactions remains unresolved but fascinating,and is crucial for understanding Fenton chemistry and the development and application of efficient heterogeneous Fenton technologies.Iron-based materials usually possess high catalytic activity,low cost,negligible toxicity and easy recovery,and are a superior type of heterogeneous Fenton catalysts.Therefore,this article reviews the fundamental but important interfacial mechanisms of heterogeneous Fenton reactions catalyzed by iron-based materials..OH,hydroperoxyl radicals/superoxide anions（HO2./O2^-.）and high-valent iron are the three main types of reactive oxygen species（ROS）,with different oxidation reactivity and selectivity.Based on the mechanisms of ROS generation,the interfacial mechanisms of heterogeneous Fenton systems can be classified as the homogeneous Fenton mechanism induced by surface-leached iron,the heterogeneous catalysis mechanism,and the heterogeneous reaction-induced homogeneous mechanism.Different heterogeneous Fenton systems catalyzed by characteristic iron-based materials are comprehensively reviewed.Finally,related future research directions are also suggested.
基金Acknowledgments This work is supported by the National Nature Science Foundation of China （Nos. 31070155 and 11172301）, the ＂Western Light Talent Culture＂ Project, the Distinguished Young Scientists Project of Hubei Province （2012FFA002）, the Co-joint project of Chinese Academy of Sciences and the ＂Top Hundred Talents＂ Program of Chinese Academy of Sciences.
文摘Nature is a huge gallery of art involving nearly perfect structures and properties over the millions of years of development. Many plants and animals show water-repellent properties with fine micro-structures, such as lotus leaf, water skipper and wings of butterfly. Inspired by these special surfaces, the artificial superhydrophobic surfaces have attracted wide attention in both basic research and industrial applications. The wetting properties of superhydrophobic surfaces in nature are affected by the chemical compositions and the surface topographies. So it is possible to realize the biomimetic superhydrophobic surfaces by tuning their surface roughness and surface free energy correspondingly. This review briefly introduces the physical-chemical basis of superhydrophobic plant surfaces in nature to explain how the superhydrophobicity of plant surfaces can be applied to different biomimetic functional materials with relevance to technological applications. Then, three classical effects of natural surfaces are classified： lotus effect, salvinia effect, and petal effect, and the promising strategies to fabricate biomimetic su- perhydrophobic materials are highlighted. Finally, the prospects and challenges of this area in the future are proposed.
基金financially supported by the State Key Research Development Program of China(No.2016YFC0600708)the Fundamental Research Funds for the Central Universities of China(No.2011QZ02)the Yue Qi Distinguished Scholar Project,China University of Mining&Technology,Beijing
文摘Anionic surfactant sodium dodecyl benzene sulfonate(SDBS)at varying concentrations was selected to investigate the influence on the wettability of Zhaozhuang Coal by molecular dynamics simulation.Six groups of water/surfactant/coal systems with different concentrations were constructed.The influence of surfactant with different concentrations on the wettability of coal was concluded by analyzing various properties from the energetic behaviors to the dynamic characteristics.The results show that the interfacial tension decreases sharply and then rises slowly with the increase of SDBS surfactant concentration,obtaining that surfactants can obviously reduce the interfacial tension.The surfactant molecules could be detected at the water/coal interface through analyzing the system’s relative concentration distribution.In addition,the difference in the wettability of surfactants on coal surfaces is caused by the spatial distribution differences of alkyl chains and the benzene ring of the surfactant molecules.And the negative interaction energy between SDBS and the coal surface indicates that adsorption process is spontaneous.Furthermore,it is of great practical significance for improving the dust reduction effect and reducing the disaster of coal dust by exploring the effects of surfactant molecules on the wettability of coal.
基金Funded by the Fundamental Research Funds for the Central Universities(WUT:142201001)
文摘The feasibility of using coral reef sand（CRS） in Portland cement concrete is investigated by testing the mechanical property and microstructure of concrete. The composition, structure and properties of the CRS are analyzed. Mechanical properties and microstructure of concrete with CRS are studied and compared to concrete with natural river sand. The relationship between the microstructure and performance of CRS concrete is established. The CRS has a porous surface with high water intake capacity, which contributes to the mechanical properties of concrete. The interfacial transition zone between the cement paste and CRS is densified compared to normal concrete with river sand. Hydration products form in the pore space of CRS and interlock with the matrix of cement paste, which increases the strength. The total porosity of concrete prepared with CRS is higher than that with natural sand. The main difference in pore size distribution is the fraction of fine pores in the range of 100 nm.
基金supported by the National Natural Science Foundation of China (No. 51572112)the National Key R&D Program of China (No. 2017YFB0310400)+3 种基金the 333 Talents Project (No. BRA2017387)Six Talent Peaks Project (No. TD-XCL-004)Innovation/Entrepreneurship Program ([2015]26)Qing Lan Project ([2016]15) of Jiangsu Province
文摘Silicon carbide(SiC) has been widely concerned for its excellent overall mechanical and physical properties, such as low density, good thermal-shock behavior, high temperature oxidation resistance, and radiation resistance; as a result, the SiC-based materials have been or are being widely used in most advanced fields involving aerospace, aviation, military, and nuclear power. Joining of SiC-based materials(monolithic SiC and SiCf/SiC composites) can resolve the problems on poor processing performance and difficulty of fabrication of large-sized and complex-shaped components to a certain extent, which are originated from their high inherent brittleness and low impact toughness.Starting from the introduction to SiC-based materials, joining of ceramics, and joint strength characterization, the joining of SiC-based materials is reviewed by classifying the as-received interlayer materials, involving no interlayer, metallic, glass-ceramic, and organic interlayers. In particular, joining processes(involving joining techniques and parameter conditions), joint strength,interfacial microstructures, and/or reaction products are highlighted for understanding interfacial behavior and for supporting development of application-oriented joining techniques.
基金Supported by Program for the National Natural Science Foundation of China (Nos. 51577021 and U1704253)the Fundamental Research Funds for the Central Universities (DUT17GF107)
文摘Crystalline Fe/MnO@C core–shell nanocapsules inlaid in porous amorphous carbon matrix(FMCA)was synthesized successfully with a novel confinement strategy.The heterogeneous Fe/MnO nanocrystals are with approximate single-domain size which gives rise to natural resonance in 2–18 GHz.The addition of MnO2 confines degree of graphitization catalyzed by iron and contributes to the formation of amorphous carbon.The heterogeneous materials composed of crystalline–amorphous structures disperse evenly and its density is significantly reduced on account of porous properties.Meanwhile,adjustable dielectric loss is achieved by interrupting Fe core aggregation and stacking graphene conductive network.The dielectric loss synergistically with magnetic loss endows the FMCA enhanced absorption.The optimal reflection loss(RL)is up to−45 dB,and the effective bandwidth(RL<−10 dB)is 5.0 GHz with 2.0 mm thickness.The proposed confinement strategy not only lays the foundation for designing high-performance microwave absorber,but also offers a general duty synthesis method for heterogeneous crystalline–amorphous composites with tunable composition in other fields.
基金National Natural Science Foundation of China(51772272)Natural Science Funds for Distinguished Young Scholar of Zhejiang Province(LR20E020001)+2 种基金China Postdoctoral Science Foundation(2020M671785 and 2020T130597)Natural Science Foundation of Zhejiang Province(LY18E020009,LY21E020005,and 2020C01130)the Foundation of State Key Laboratory of Coal Conversion(J20-21-909).
文摘Lithium(Li)metal is considered as one of the most promising anode materials for next-generation high-energy-density storage systems.However,the practical application of Li metal anode is hindered by interfacial instability and air instability due to the highly reactivity of Li metal.Unstable interface in Li metal batteries(LMBs)directly dictates Li dendrite growth,“dead Li”and low Coulombic efficiency,resulting in inferior electrochemical performance of LMBs and even safety issues.In addition,its sensitivity to ambient air leads to the severe corrosion of Li metal anode,high requirements of production and storage,and increased manufacturing cost.Plenty of efforts in recent years have overcome many bottlenecks in these fields and hastened the practical applications of high-energy-density LMBs.In this review,we focus on emerging methods of these two aspects to fulfill a stable and low cost electrode.In this perspective,design artificial solid electrolyte interphase(SEI)layers,construct three-dimensional conductive current collectors,optimize electrolytes,employ solid-state electrolytes,and modify separators are summarized to be propitious to ameliorate interfacial stability.Meanwhile,ex situ/in situ formed protective layers are highlighted in favor of heightening air stability.Finally,several possible directions for the future research on advanced Li metal anode are addressed.
基金National Natural Science Foundation of China(51773169 and 51973173)Guangdong Basic and Applied Basic Research Foundation(2019B1515120093)+2 种基金Technological Base Scientific Research ProjectsNatural Science Basic Research Plan for Distinguished Young Scholars in Shaanxi Province(2019JC-11)Polymer Electromagnetic Functional Materials Innovation Team of Shaanxi Sanqin Scholars.
文摘Rapid development of energy,electrical and electronic technologies has put forward higher requirements for the thermal conductivities of polymers and their composites.However,the thermal conductivity coefficient(λ)values of prepared thermally conductive polymer composites are still difficult to achieve expectations,which has become the bottleneck in the fields of thermally conductive polymer composites.Aimed at that,based on the accumulation of the previous research works by related researchers and our research group,this paper proposes three possible directions for breaking through the bottlenecks:(1)preparing and synthesizing intrinsically thermally conductive polymers,(2)reducing the interfacial thermal resistance in thermally conductive polymer composites,and(3)establishing suitable thermal conduction models and studying inner thermal conduction mechanism to guide experimental optimization.Also,the future development trends of the three above-mentioned directions are foreseen,hoping to provide certain basis and guidance for the preparation,researches and development of thermally conductive polymers and their composites.
文摘Lithium metal is considered the ideal anode material for Li-ion-based batteries because it exhibits the highest specific capacity and lowest redox potential for this type of cells. However, growth of Li dendrites, unstable solid electrolyte interphases, low Coulombic efficiencies, and safety hazards have significantly hindered the practical application of metallic Li anodes. Herein, we propose a three-dimensional （3D） carbon nanotube sponge （CNTS） as a Li deposition host. The high specific surface area of the CNTS enables homogenous charge distribution for Li nucleation and minimizes the effective current density to overcome dendrite growth. An additional conformal A1203 layer on the CNTS coated by atomic layer deposition （ALD） robustly protects the Li metal electrode/electrolyte interface due to the good chemical stability and high mechanical strength of the layer. The Li@ALD-CNTS electrode exhibits stable voltage profiles with a small overpotential ranging from 16 to 30 mV over 100 h of cycling at 1.0 mA·cm^-2. Moreover, the electrodes display a dendrite-free morphology after cycling and a Coulombic efficiency of 92.4% over 80 cycles at 1.0 mA·cm^-2 in an organic carbonate electrolyte, thus demonstrating electrochemical stability superior to that of planar current collectors. Our results provide an important strategy for the rational design of current collectors to obtain stable Li metal anodes.
文摘Nanoparticles have already gained attentions for their countless potential applications in enhanced oil recovery.Nano-sized particles would help to recover trapped oil by several mechanisms including interfacial tension reduction, impulsive emulsion formation and wettability alteration of porous media. The presence of dispersed nanoparticles in injected fluids would enhance the recovery process through their movement towards oil–water interface. This would cause the interfacial tension to be reduced. In this research, the effects of different types of nanoparticles and different nanoparticle concentrations on EOR processes were investigated. Different flooding experiments were investigated to reveal enhancing oil recovery mechanisms. The results showed that nanoparticles have the ability to reduce the IFT as well as contact angle, making the solid surface to more water wet. As nanoparticle concentration increases more trapped oil was produced mainly due to wettability alteration to water wet and IFT reduction. However, pore blockage was also observed due to adsorption of nanoparticles, a phenomenon which caused the injection pressure to increase. Nonetheless, such higher injection pressure could displace some trapped oil in the small pore channels out of the model. The investigated results gave a clear indication that the EOR potential of nanoparticle fluid is significant.
基金The National Natural Science Foundation of China
文摘To reduce friction drag with bionic method in a more feasible way, the surface microstructure of fish scales was analyzed attempting to reveal the biologic features responding to skin friction drag reduction. Then comparable bionic surface mimicking fish scales was fabricated through coating technology for drag reduction. The paint mixture was coated on a substrate through a self-developed spray-painting apparatus. The bionic surface with micron-scale caves formed spontaneously due to the interra- cial convection and deformation driven by interfacial tension gradient in the presence of solvent evaporation. Comparative experiments between bionic surface and smooth surface were performed in a water tunnel to evaluate the effect of bionic surface on drag reduction, and visible drag reduction efficiency was obtained. Numerical simulation results show that gas phase de- velops in solid-liquid interface of bionic surface with the effect of surface topography and partially replaces the solid-liquid shear force with gas-liquid shear force, hence reducing the skin friction drag effectively. Therefore, with remarkable drag re- duction performance and simple fabrication technology, the proposed drag reduction technique shows the promise for practical applications.
文摘Chemical enhanced oil recovery(EOR)and particularly surfactant injection has recently received a great deal of attention.The suggested recovery mechanisms after injecting surfactants include wettability alteration and IFT reduction.If a surfactant is properly selected according to the environmental variables-such as pressure,temperature,salinity,it can lead to more efficient enhanced recovery from an oil reservoir.On the other hand,poor selection of the surfactant can result in a low recovery and can even become detrimental to the reservoir due to undesirable wettability alteration and possible rock dissolution resulting in a chemical reaction with displacing fluid and blockage of the pore space.Also,choosing the wrong surfactant without considering the rock mineralogy may result in high adsorption on the pore surface of the rock and unnecessary waste of resources.It is also worthy to note that surfactants are some of the most expensive chemicals used during EOR.Extensive literature review suggests that anionic surfactant are the preferred surfactant category for EOR especially when it comes to sandstone reservoirs.Occasionally,in specific situations a better performance have been reported after injecting cationic,non-ionic or mixtures of both surfactants,particularly when dealing with carbonate reservoirs.This paper presents in detail a review of the most commonly applied surfactants in EOR studies and the optimum application criteria for of each type.To the best of the authors'knowledge,such detailed and comprehensive review is not available in the literature,presently.
基金the financial supports of the National Natural Science Foundation of China(Nos.21771169,51801075,and 11722543)the National Key Research and Development Program of China(No.2017YFA0206703)+1 种基金Anhui Provincial Natural Science Foundation(No.BJ2060190077)Re-cruitment Program of Global Expert,and the Fundamental Research Funds for the Central Universities(Nos.WK2060190074,WK2060190081,and WK2310000066).
文摘Molybdenum disulfide (MoS2) has been recognized as one of the most promising candidates to replace precious Pt for hydrogen evolution reaction (HER) catalysis, due to the natural abundance, low cost, tunable electronic properties, and excellent chemical stability. Although notable processes have been achieved in the past decades, their performance is still far less than that of Pt. Searching effective strategies to boosting their HER performance is still the primary goal. In this review, the recent process of the electronic regulation of MoS2 for HER is summarized, including band structure engineering, electronic state modulation, orbital orientation regulation, interface engineering. Last, the key challenges and opportunities in the development of MoS2-based materials for electrochemical HER are also discussed.
基金supported by the National Natural Science Foundation of China(Grant no.52072411,51932011)Natural Science Foundation of Hunan Province(Grant no.2021JJ20060,2018RS3019,and 2019JJ30033)+1 种基金the Science and Technology Innovation Program of Hunan Province(Grant no.2021RC3001)the Fundamental Research Funds for the Central Universities of Central South University(2021zzts0089).
文摘Safe,inexpensive aqueous zinc-ion batteries(AZIBs)are regarded as promising energy storage devices.However,they still face issues,including dissolution and collapse of the cathode as well as H_(2)evolution and the growth of Zn dendrites on the Zn anode.Herein,we simultaneously regulate the cations and anions in the electrolyte for high-capacity,high-stability aqueous zinc–vanadium(Zn–V)batteries based on a bimetallic cation-doped Na_(0.33)K_(0.1)V_(2)O_(5)·nH_(2)O cathode.We demonstrate that Na^(+) cations suppress cathode dissolution and restrain Zn dendrite growth on the anode via an electrostatic shield effect.We also illustrate that ClO_(4)^(-) anions participate in energy storage at the cathode and are reduced to Cl^(-),generating a protective layer on the Zn anode surface and providing a stable interface to decrease Zn dendrites and H_(2)evolution during long-term cycling.When Na^(+) and ClO_(4)^(-) are introduced into an aqueous ZnSO_(4) electrolyte,a Zn/Zn symmetric cell shows durable and reversible Zn stripping/plating for 1500 h at a current density of 1 mA cm^(-2) and with an area capacity of 1 mAh cm^(-2).Zn/Na_(0.33)K_(0.1)V_(2)O_(5)·nH_(2)O full batteries exhibit a high capacity of 600 mAh g^(-1)at 0.1 A g^(-1) and long-term cycling performance for 5000 cycles,with a capacity of 200 mAh g^(-1) at 20 Ag^(-1).
基金Projects 50574107 supported by the National Natural Science Foundation of China 2002 by the Teaching and Research Award Program for OutstandingYoung Teachers in Higher Education Institutions of Ministry of Education of China
文摘Interfacial interactions involving Van der Waals force, hydrophobic attractive force and hydration exclusive force were investigated in this paper. The interfacial interactive free energy of a series of interfaces occurring between minerals, water, collectors and bubble was calculated. The results show that a Van der Waals attractive force and a hydrophobic attractive force exist between each mineral and water interface. The hydrophobic attractive force between molybdenite and water is markedly weaker than the hydrophobic attractive force between gangue and water. The hydrophobic attractive force between collector molecules and water is the main driving force that causes the collectors to become dispersed in the pulp. The strong hydrophobic attractive force between molybdenite and the bubble interface is the basic reason for the natural floatability of molybdenite. The Van der Waals force between molybdenite and the collectors is attractive in water solution, but it is not the cause of the main force between them. The main force that results in the collection effect is a hydrophobic attractive force caused by the Lewis acid-base interaction at the molybdenite surface. A floatation experiment shows that the adsorption intensity of the collector on the molybdenite surface is not the crucial factor for molybdenite floatation. Rather, the dispersing capability of the collector in the water phase and its selectivity for the various minerals in the floatation system are more important.
基金financially supported by the National Natural Science Foundation of China(Nos.51672064 and 51972089)。
文摘Developing electromagnetic(EM) wave absorbing materials with low reflection coefficient and optimal operating frequency band is urgently needed on account of the increasingly serious EM pollution. However, the applications of common EM absorbing materials are encumbered by poor high-temperature stability, poor oxidation resistance, narrow absorption bandwidth or high density. Herein, the strong EM absorption capability and wide efficient absorption bandwidth of high entropy ceramics are reported for the first time, which are designed by a combination of the novel high entropy(HE) rare earth silicide carbides/rare earth oxides(RE3 Si2 C2/RE2 O3). Three HE powders, i.e., HERSC-1(HE(Tm0.2 Y0.2 Dy0.2 Gd0.2 Tb0.2)3 Si2 C2),HERSC-2 HE(Tm0.2 Y0.2 Dy0.2 Gd0.2 Tb0.2)3 Si2 C2/HE(Tm0.2 Y0.2 Dy0.2 Gd0.2 Tb0.2)2 O3) and HERSC-3(HE(Tm0.2 Y0.2 Dy0.2 Gd0.2 Tb0.2)3 Si2 C2/HE(Tm0.2 Y0.2 Dy0.2 Gd0.2 Tb0.2)2 O3), are synthesized. Although HERSC-1 exhibits a limited absorption effect(the minimum reflection loss(RLmin) is-11.6 d B at 3.4 mm) and a relatively narrow effective absorption bandwidth(EAB) of 1.7 GHz, the optimal absorption RLminvalue and EAB of HERSC-2 and HERSC-3 are-40.7 d B(at 2.9 mm), 3.4 GHz and-50.9 d B(at 2.0 mm), 4.5 GHz,respectively, demonstrating strong microwave absorption capability and wide absorption bandwidth.Considering the better stability, low density and strong EM absorption effect, HE ceramics are promising as a new type of EM absorbing materials.
基金financially supported by the National Basic Research Program of China(No.2009CB623701)the National Natural Science Foundation of China(Nos.11374174,50971075 and 51390471)
文摘Nickel-based single-crystal superalloys are the key materials for the manufacturing and development of advanced aeroengines. Rhenium is a crucial alloying element in the advanced nickel-based single-crystal superalloys for its special strengthening effects. The addition of Re could effectively enhance the creep properties of the single-crystal superalloys; thus, the content of Re is considered as one of the characteristics in different-generation single-crystal superalloys. Owing to the fundamental importance of rhenium to nickel-based single-crystal superalloys, much progress has been made on understanding of the effect of rhenium in the single-crystal superalloys. While the effect of Re doping on the nickelbased superalloys is well documented, the origins of the socalled rhenium effect are still under debate. In this paper,the effect of Re doping on the single-crystal superalloys and progress in understanding the rhenium effect are reviewed. The characteristics of the d-states occupancy in the electronic structure of Re make it the slowest diffusion elements in the single-crystal superalloys, which is undoubtedly responsible for the rhenium effect, while the postulates of Re cluster and the enrichment of Re at the c/c0 interface are still under debate, and the synergistic action of Re with other alloying elements should be further studied.Additionally, the interaction of Re with interfacial dislocations seems to be a promising explanation for the rhenium effect. Finally, the addition of Ru could help suppress topologically close-packed（TCP） phase formation and strengthen the Re doping single-crystal superalloys.Understanding the mechanism of rhenium effect will be beneficial for the effective utilization of Re and the design of low-cost single-crystal superalloys.
文摘In this article, a new type of Cu-Ti3SiC2 composite powder prepared using the electroless plating technique was introduced. The initial Ti3SiC2 particles are 11 μm in diameter on an average. The Cu plating was carried out at middle temperature （62-65℃） with the application of ultrasonic agitation. The copper deposition rate was determined by measuring the weight gain of the powder after plating. It has been found that the pretreatment of Ti3SiC2 powder is very important to obtain copper nanoparticles on the surface of Ti3SiC2 The optimum procedure before plating aimed to add activated sites and the adjustment of the traditional composition of the electroless copper plating bath could decelerate the copper deposition rate to 0.8 gm/h. X-ray diffraction （XRD） indicates that the chemical composition of the plating layer is copper. SEM images show that the surface of the Ti3SiC2 particles is successfully coated with continuous copper layer. The wetting property between the copper matrix and Ti3SiC2 can be improved so as to increase the interfacial strength.
基金supported by the National Key Scientific and Technological Projects (2008ZX05011)
文摘The influences of an anionic-nonionic composite surfactant and petroleum sulfonate, used in surfactant-polymer flooding in Shengli Gudong oilfield, East China, on the interfacial properties of Gudong crude model oil and synthetic formation water was studied by measuring interfacial tension, interfacial viscoelasticity and Zeta potential. The in？ uence of the surfactants on the stability of Gudong water-in-oil （W/O） and oil-in-water （O/W） emulsions was evaluated by separating water from the W/O emulsion and residual oil in the aqueous phase of the O/W emulsion respectively. The results showed that the two kinds of surfactants, namely anionic-nonionic composite surfactant and petroleum sulfonate, are both able to decrease the interfacial tension between the oil phase and the aqueous phase and increase the surface potential of the oil droplets dispersed in the O/W emulsion, which can enhance the stability of the W/O and O/W crude oil emulsions. Compared with petroleum sulfonate, the anionic-nonionic composite surfactant is more interfacially active and able to enhance the strength of the interfacial film between oil and water, hence enhance the stability of the W/O and O/W emulsions more effectively.
