Effect of SDBS on interfacial electron transfer at the liquid/liquid interface by thin layer method

The effect of an adsorbed anionic surfactant sodium dodecyl benzene sulfonate （SDBS） on electron transfer （ET） reaction between ferricyanide aqueous solution and decamethylferrocene （DMFc） located on the adjacent organic phase was investigated for the first time by thin layer method. The adsorption of SDBS at the interface resulted in a decay in the cathodic plateau current of bimolecular reaction with increasing concentrations of SDBS in aqueous phase. However, the rate constant of electron transfer （ket） increased monotonically as the SDBS concentrations increased from 0 to 200 p, moFL. The experimental results showed that SDBS formed patches on the interface and influenced the structure of electrical double layer. 2009 Xiao Quan Lu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Voltammetric Studies on Heteropoly Phosphotungstovanadate Anions Across the Liquid/Liquid Interface

Electrochemical transfer behavior of V ⅤW 11 -V Ⅴ 3W 9 heteropoly anions on the water/nitrobenzene interface was investigated by means of cyclic voltammetry. The effect of the solution acidity on the transfer behavior and the stable pH range for the heteropoly anions were studied. The stability of mixed tungstovanadate decreases with increasing the number of vanadium atoms. The main transfer species within the potential window have the negative charges of 4 and the transfer process is diffusion controlled. The apparent transfer potential Δ w o Ψ 0 and the free energy Δ G 0 w→o tr for the heteropoly anions can be obtained from the experimental data. For the different anions, the Δ w o Ψ 1/2 pH relationship can be expressed as: Δ w o Ψ 1/2 =constant-53pH.

Investigation of the oxidation of hydroquinone at the liquid/liquid interface

The oxidation of hydroquinone(QH_2) was investigated for the first time at liquid/liquid(L/L) interface by scanning electrochemical microscopy(SECM).In this study,electron transfer(ET) from QH_2 in aqueous to ferrocene(Fc) in nitrobenzene (NB) was probed.The apparent heterogeneous rate constants for ET reactions were obtained by fitting the experimental approach curves to the theoretical values.The results showed that the rate constants for oxidation reaction of QH_2 were sensitive to the changes of the dri...

Kinetic comparison between ferric ion and decamethyferrocene at the liquid/liquid interface as studied by scanning electrochemical microscopy

Comparison in electron transfer(ET) processes from decamethyferrocene(DMFe) in nitrobenzene(NB) to ferric ion in aqueous phase was investigated for the first time by the scanning electrochemical microscopy(SECM).As compared with the system of Fe(CN)_6^(3-)-DMFe,the ET rate obtained from Fe^(3+)-DMFe was lower in spite of larger driving force,which may arise from the effect of reorganization energy.Otherwise,the effect of common ion on rate constants was also probed and results suggested additional complexit...

Investigation of the Lipophilicity of 2-Benzoylpyridine-Thiosemicarbazone Based on the Ion Transfer across the Liquid/Liquid Interface

The ion transfer reaction of 2-benzoylpyridine-thiosemicarbazone (HL), which has antimicrobial and antifungal properties and anticancer activity, has been studied to determine its lipophilicity by cyclic voltammetry at the water/1,2-dichloroethane (1,2-DCE) interface. The physicochemical parameters such as standard partition coefficient (lgPI)andthestandardGibbsenergyoftransfer("G0tr,,wI "o)oftheprotonatedformoftheligandwere measured asa function of pH in aqueous phase. The protonated form of the ligand exhibited reversible or quasi-reversible voltammograms at the1,2-DCEintherangeofpH1-5.Theprotonationconstantsoftheligand,pKa1andpKa2,weredeterminedspectrophotometrically and were found to be 12.14 and 3.24, respectively. The standard Gibbs energy of transfer ("G0tr,,wN" o) and the partition coefficient of neutral species (lgPN) were also determined by the shake-flask method. The standard Gibbs energy of transfer of this compound across the water/1,2-DCE interface was evaluated as the quantitative measure of its lipophilicity. The difference between lgPI and lgPN was related to the degree of charge delocalization and was used to evaluate qualitatively the lipophilicity of the ligand.

Smart Cellulose‑Based Janus Fabrics with Switchable Liquid Transportation for Personal Moisture and Thermal Management

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.

Molecular simulation study of the microstructures and properties of pyridinium ionic liquid[HPy][BF_(4)]mixed with acetonitrile

The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.

Interfacial friction induced capillary flow within nanofiber-supported ionic liquid droplets

As global economic growth increases,the demand for energy sources boosts.While fossil fuels have traditionally satisfied this demand,their environmental influence and limited reserves require alternatives.Fossil fuel combustion contributes substantially to greenhouse gas emissions,with a pressing need to halve these emissions by 2030 and target net-zero by 2050.Renewable energy sources,contributing currently to 29%of global electricity,are viewed as promising substitutes.With wind energy's potential,Zheng's team developed a novel method to harness even low wind speeds using well-aligned nanofibers and an innovative“drop wind generator”.This system,combining moisture-saturated ionic liquid 3-Methyl-1-octylimidazolium chloride with specific nanofiber arrays,exploits wind-inducedflows for energy conversion.This study highlights the vast untapped potential of low-speed wind as a sustainable energy source potentially for electronics.

Evolution of bonding interface in solid-liquid cast-rolling bonding of Cu/Al clad strip

Cu/Al clad strips are prepared using solid?liquid cast-rolling bonding(SLCRB)technique with a d160mm×150mm twin-roll experimental caster.The extent of interfacial reactions,composition of the reaction products,and their micro-morphology evolution in the SLCRB process are investigated with scanning electron microscope(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD).In the casting pool,initial aluminized coating is first generated on the copper strip surface,with the diffusion layer mainly consisting ofα(Al)+CuAl2and growing at high temperatures,with the maximum thickness of10μm.After sequent rolling below the kiss point,the diffusion layer is broken by severe elongation,which leads to an additional crack bond process with a fresh interface of virgin base metal.The average thickness is reduced from10to5μm.The reaction products,CuAl2,CuAl,and Cu9Al4,are dispersed along the rolling direction.Peeling and bending test results indicate that the fracture occurs in the aluminum substrate,and the morphology is a dimple pattern.No crack or separation is found at the bonding interface after90°-180°bending.The presented method provides an economical way to fabricate Cu/Al clad strip directly.

Insight into the behavior at the hygroscopicity and interface of the hydrophobic imidazolium-based ionic liquids

How to completely remove the water from ionic liquids(ILs)is difficult for researchers because of the hygroscopicity of ILs.In order to study the hygroscopicity of ILs,two kinds of ILs,1-Butyl-3-methylimidazolium hexafluorophosphate([Bmim][PF6])and 1-Butyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)([Bmim][NTf_(2)])were investigated by molecular dynamics simulations.Although[Bmim][PF6]and[Bmim][NTf_(2)]are hydrophobic,both of the ILs could absorb water molecules from the vapor.In this work,the process of absorbing water from the vapor phase was studied,and the water molecules could disperse into the IL.Aggregation was observed with increasing the water concentration.Although the absorbed water increases obviously,the amount of free water and small cluster in the ILs does not change significantly and always stays at a certain level.The amount of free water and small cluster in[Bmim][PF6]is more than that in[Bmim][NTf_(2)],which is consistent with their hydrophobicity.In addition,the liquid-vacuum and liquid–liquid interfaces of the ILs were simulated and analyzed in detail.The number density distribution and angle distribution indicated that[Bmim]+cations arrangement regularly at the IL-vacuum interface.The butyl chain point to the vacuum,while the imidazlium ring is close to the IL phase region and perpendicular to the interface.While at the IL-water interface,the cations and anions are disordered.

Passivating buried interface with multifunctional novel ionic liquid containing simultaneously fluorinated anion and cation yielding stable perovskite solar cells over 23% efficiency

Interfacial defects and energy barrier would result in serious interfacial non-radiative recombination losses.In addition,the quality of perovskite films is highly dependent on deposition substrates.Consequently,there is an urgent desire to develop multifunctional interface modulators to manage the interface between electron transport layer and perovskite layer.Here,we report a multifunctional buried interface modulation strategy that 4-fluoro-phenylammonium tetrafluoroborate (FBABF_(4)) consisting of simultaneously fluorinated anion and cation is inserted between SnO_(2)layer and perovskite layer.It is uncovered by time-of-flight secondary ion mass spectroscopy that the anion and cation in modifier are mainly located at this interface,which is put down to coordination bond of the fluorine atom on BF_(4)^(-) with SnO_(2),and the hydrogen bond of the fluorine atom on FBA^(+) with formamidinium.This suggests that simultaneous fluorination of anion and cation in the ionic liquid molecule is of crucial importance to ameliorate interfacial contact through chemical linker.The interface modification approach enables the realization of interfacial defect passivation,interfacial energy band alignment modulation,and perovskite crystallization manipulation,which are translated into enhanced efficiency and stability as well as significantly suppressed hysteresis.The multiple functions of FBABF_(4) endow the modified solar cells excellent photovoltaic performance with an efficiency exceeding 23%along with appealing long-term stability.This work highlights the critical role of fluorination strategy in engineering multifunctional organic salt modulators for improving interfacial contact.

Probing non-polarizable liquid/liquid interfaces using scanning ion conductance microscopy

The study of microscopic structure of a liquid/liquid interface is of fundamental importance due to its close relation to the thermodynamics and kinetics of interfacial charge transfer reactions.In this article,the microscopic structure of a non-polarizable water/nitrobenzene(W/NB)interface was evaluated by scanning ion conductance microscope(SICM).Using SICM with a nanometer-sized quartz pipette filled with an electrolyte solution as the probe,the thickness of this type of W/NB interface could be measured at sub-nanometer scale,based on the continuous change of ionic current from one phase to another one.The effects for thicknesses of the non-polarizable W/NB interfaces with different electrolyte concentrations,the Galvani potentials at the interface and the applied potentials on the probe were measured and systematically analyzed.Both experimental setups,that is an organic phase up and an aqueous down,and a reverse version,were employed to acquire the approach curves.These data were compared with those of an ideal polarizable interface under the similar experimental conditions,and several characteristics of non-polarizable interfaces were found.The thickness of a non-polarizable interface increases with the decrease of electrolyte concentration and the increase of applied potential,which is similar to the situation of a polarizable liquid/liquid interface.We also find that the Galvani potential across a non-polarizable interface can also influence the interfacial thickness,this phenomenon is difficult to observe when using polarizable interface.Most importantly,by the comparison of two kinds of liquid/liquid interfaces,we experimentally proved that much more excess ions are gathered in the space charge layer of non-polarizable interfaces than in that of polarizable interfaces.These results are consistent with the predictions of molecular dynamic simulations and X-ray reflectivity measurements.

An interface-reconstruction effect for rechargeable aluminum battery in ionic liquid electrolyte to enhance cycling performances

Aluminum(Al) metal has been regarded as a promising anode for rechargeable batteries because of its natural abundance and high theoretical specific capacity. However, rechargeable aluminum batteries(RABs) using A1 metal as anode display poor cycling performances owing to interface problems between anode and electrolyte. The solid-electrolyte interphase(SEI) layer on the anode has been confirmed to be essential for improving cycling performances of rechargeable batteries. Therefore, we immerse the Al metal in ionic liquid electrolyte for some time before it is used as anode to remove the passive film and expose fresh Al to the electrolyte. Then the reactions of exposed Al, acid, oxygen and water in electrolyte are occurred to form an SEI layer in the cycle. Al/electrolyte/V_2 O_5 full batteries with the thin, uniform and stable SEI layer on Al metal anode perform high discharge capacity and coulombic efficiency(CE). This work illustrates that an SEI layer is formed on Al metal anode in the cycle using a simple and effective pretreatment process and results in superior cycling performances for RABs.

Microstructure and Solid/Liquid Interface Evolutions of Directionally Solidified Fe-Al-Ta Eutectic Alloy

A modified Bridgman directional solidification technique was used to prepare Fe-Al-Ta eutectic in situ composites at different growth rates ranging from 6 to 80 μm/s. The directionally solidified FeAl-Ta eutectic composites are composed of two phases: Fe（Al,Ta） matrix phase, and Fe2 Ta（Al） Laves phase. Solidification microstructure is affected by solidification rate. Microstructure of the Fe-Al-Ta eutectic alloy grown at 6.0 μm/s is broken-lamellar eutectic. Eutectic colonies are formed with the increase of the solidification rate. Microstructures are mainly composed of the lamellar or fibrous eutectic at the center of the colony and coarse lamellar eutectic zone at the boundary. Meanwhile, the inter-lamellar spacing（or the inter-rod spacing） is decreased. The spacing adjustments are also observed in Fe-Al-Ta eutectic alloy. The solid/liquid interface evolves from planar interface to shallow cellular interface, then to deep cellular, and finally to shallow cellular planar with the increase of the solidification rate.

An APXPS endstation for gas–solid and liquid–solid interface studies at SSRF

In the past few decades, various surface analysis techniques find wide applications in studies of interfacial phenomena ranging from fundamental surface science,catalysis, environmental science and energy materials.With the help of bright synchrotron sources, many of these techniques have been further advanced into novel in-situ/operando tools at synchrotron user facilities, providing molecular level understanding of chemical/electrochemical processes in-situ at gas–solid and liquid–solid interfaces.Designing a proper endstation for a dedicated beamline is one of the challenges in utilizing these techniques efficiently for a variety of user's requests. Many factors,including pressure differential, geometry and energy of the photon source, sample and analyzer, need to be optimized for the system of interest. In this paper, we discuss the design and performance of a new endstation at beamline02 B at the Shanghai Synchrotron Radiation Facility for ambient pressure X-ray photoelectron spectroscopy studies.This system, equipped with the newly developed hightransmission HiPP-3 analyzer, is demonstrated to be capable of efficiently collecting photoelectrons up to 1500 eV from ultrahigh vacuum to ambient pressure of 20 mbar.The spectromicroscopy mode of HiPP-3 analyzer also enables detection of photoelectron spatial distribution with resolution of 2.8 ± 0.3 lm in one dimension. In addition,the designing strategies of systems that allow investigations in phenomena at gas–solid interface and liquid–solid interface will be highlighted through our discussion.

Measurement of Liquid Concentration Fields Near Interface with Cocurrent Gas-Liquid Flow Absorption Using Holographic Interferometry

Real-time laser holographic interferometry was applied to measure liquid concentrations of CO2 in the vicinity of gas-liquid free interface under the conditions of cocurrent gas-liquid flow for absorption of CO2 by ethanol. The influences of the Reynolds number on the measurable interface concentration and on the film thickness were discussed. The results show that CO2 concentration decreases exponentially along the mass transfer direction,and the concentration gradient increases as Reynolds number of either liquid or gas increases. CO2 concentrations fluctuate slightly along the direction of flow; on the whole, there is an increase in CO2 concentration. The investigation also demonstrated that film thickness decreases with the increase of Reynolds number of either of the two phases. Sherwood number representing the mass transfer coefficient was finally correlated as a function of the hydrodynamic parameters and the physical properties.

Understanding fundamentals of electrochemical reactions with tender X-rays:A new lab-based operando X-ray photoelectron spectroscopy method for probing liquid/solid and gas/solid interfaces across a variety of electrochemical systems

Electrocatalysis is key to improving energy efficiency,reducing carbon emissions,and providing a sustainable way of meeting global energy needs.Therefore,elucidating electrochemical reaction mechanisms at the electrolyte/electrode interfaces is essential for developing advanced renewable energy technologies.However,the direct probing of real-time interfacial changes,i.e.,the surface intermediates,chemical environment,and electronic structure,under operating conditions is challenging and necessitates the use of in situ methods.Herein,we present a new lab-based instrument commissioned to perform in situ chemical analysis at liquid/solid interfaces using ambient pressure X-ray photoelectron spectroscopy(APXPS).This setup takes advantage of a chromium source of tender X-rays and is designed to study liquid/solid interfaces by the“dip and pull”method.Each of the main components was carefully described,and the results of performance tests are presented.Using a three-electrode setup,the system can probe the intermediate species and potential shifts across the liquid electrolyte/solid electrode interface.In addition,we demonstrate how this system allows the study of interfacial changes at gas/solid interfaces using a case study:a sodium–oxygen model battery.However,the use of APXPS in electrochemical studies is still in the early stages,so we summarize the current challenges and some developmental frontiers.Despite the challenges,we expect that joint efforts to improve instruments and the electrochemical setup will enable us to obtain a better understanding of the composition–reactivity relationship at electrochemical interfaces under realistic reaction conditions.

Treatment of discontinuous interface in liquid-solid forming with extended finite element method

Extended finite element method(XFEM) is proposed to simulate the discontinuous interface in the liquid-solid forming process.The discontinuous interface is an important phenomenon happening in the liquid-solid forming processes and it is difficult to be simulated accurately with conventional finite element method(CFEM) because it involves solid phase and liquid phase simultaneously.XFEM is becoming more and more popular with the need of solving the discontinuous problem happening in engineering field.The implementation method of XFEM is proposed on Abaqus code by using UEL(user element) with the flowchart.The key is to modify the element stiffness in the proposed method by using UEL on the platform of Abaqus code.In contrast to XFEM used in the simulation of solidification,the geometrical and physical properties of elements were modified at the same time in our method that is beneficial to getting smooth interface transition and precise analysis results.The analysis is simplified significantly with XFEM.

Orientation and Structure of Ionic Liquid Cation at Air/[bmim][BF4] Aqueous Solution Interface

The watermiscible room temperature ionic liquid 1butyl3methylimidazolium tetrafluorob orate （[bmim] [BF4]） is a model system for studying the interactions between ionic liquid and water molecules. In this work the orientational structure of the low concentrated aqueous solution of [bmim] [BF4] at the air/liquid interface was investigated by sum frequency gener ation vibrational spectroscopy. It has been found that at very low concentrations, the butyl chain exhibited a significant gauche defect, indicating a disordered conformation; and the cation ring oriented with a fairly small tilting angle at the surface. When the concentration increased, the cation ring tended to lie flat at the surface, and the gauche defects of the butyl chain decreased due to the intermolecular chainchain interactions and the consequent more ordered interfacial molecular arrangement. Additionally, the antisymmetric stretching mode in the PPP and SPS spectra exhibited a peak shift, showing that there exists more than one kind of orientation or chemical environment for the butyl CH3 group. These results may shed new light on understanding the surface behavior of watermiscible ionic liquids as well as the imidazolium based surfactants.

Mathematical Modelling of Particle Movement Ahead of the Solid-liquid Interface in Continuous Casting

Whether the particle will be trapped by the solid-liquid interface or not is dependent on its moving behavior ahead of the interface, so a mathematical model has been developed to investigate the movement of the particle ahead of the solid-liquid interface. Based on the theory for the boundary layer, the fluid velocity field near the solid-liquid interface was obtained, and the trajectories of particles were calculated by the equations of motion for particles. In this model, the drag force, the added mass force, the buoyance force, the gravitational force, the Saffman force and the Basset history force are considered. The results show that the behavior of the particle ahead of the solid-liquid interface is affected by the physical property of the particle and fluid flow. And in the continuous casting process, if it moves in the stream directed upward or downward near vertical solid-liquid interface or in the horizontal flow under the solid-liquid interface, the particle with the diameter from 5 um to 60um can reach the solid-liquid interface. But if it moves in horizontal flow above the solid-liquid interface, only the particle with the diameter from 5 um to 10 um can reach the solid-liquid interface.