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Electro-osmotic flow (EOF) is a phenomenon where fluid motion occurs in porous materials or micro/nano-channels when an external electric field is applied. In the particular example of single-molecule electrophoresis using single nanopores, the role of EOF on the translocation velocity of the analyte molecule through the nanopore is not fully understood. The complexity arises from a combination of effects from hydrodynamics in restricted environments, electrostatics emanating from charge decorations and geometry of the pores. We address this fundamental issue using the Poisson–Nernst–Planck and Navier–Stokes (PNP–NS) equations for cylindrical solid-state nanopores and three representative protein nanopores (α-hemolysin, MspA, and CsgG). We present the velocity profiles inside the nanopores as a function of charge decoration and geometry of the pore and applied electric field. We report several unexpected results: (a) The apparent charges of the protein nanopores are different from their net charge and the surface charge of the whole protein geometry, and the net charge of inner surface is consistent with the apparent charge. (b) The fluid velocity depends non-monotonically on voltage. The three protein nanopores exhibit unique EOF and velocity–voltage relations, which cannot be simply deduced from their net charge. Furthermore, effective point mutations can significantly change both the direction and the magnitude of EOF. The present computational analysis offers an opportunity to further understand the origins of the speed of transport of charged macromolecules in restricted space and to design desirable nanopores for tuning the speed of macromolecules through nanopores. [ABSTRACT FROM AUTHOR]

Polyelectrolytes can electrophoretically be driven through nanopores in order to be detected. The respective translocation events are often very fast and the process needs to be controlled to promote efficient detection. To this end, we attempt to control the translocation dynamics by coating the inner surface of a nanopore. For this, different charge distributions are chosen that result in substantial variations of the pore–polymer interactions. In addition and in view of the existing detection modalities, experimental settings, and nanopore materials, different types of sensors inside the nanopore have been considered to probe the translocation process and its temporal spread. The respective transport of polyelectrolytes through the coated nanopores is modeled through a multi-physics computational scheme that incorporates a mesoscopic/electrokinetic description for the solvent and particle-based scheme for the polymer. This investigation could underline the interplay between sensing modality, nanopore material, and detection accuracy. The electro-osmotic flow and electrophoretic motion in a pore are analyzed together with the polymeric temporal and spatial fluctuations unraveling their correlations and pathways to optimize the translocation speed and dynamics. Accordingly, this work sketches pathways in order to tune the pore–polymer interactions in order to control the translocation dynamics and, in the long run, errors in their measurements. [ABSTRACT FROM AUTHOR]

Modeling the ion concentration profile in nanochannel plays an important role in understanding the electrical double layer and electro-osmotic flow. Due to the non-negligible surface interaction and the effect of discrete solvent molecules, molecular dynamics (MD) simulation is often used as an essential tool to study the behavior of ions under nanoconfinement. Despite the accuracy of MD simulation in modeling nanoconfinement systems, it is computationally expensive. In this work, we propose neural network to predict ion concentration profiles in nanochannels with different configurations, including channel widths, ion molarity, and ion types. By modeling the ion concentration profile as a probability distribution, our neural network can serve as a much faster surrogate model for MD simulation with high accuracy. We further demonstrate the superior prediction accuracy of neural network over XGBoost. Finally, we demonstrated that neural network is flexible in predicting ion concentration profiles with different bin sizes. Overall, our deep learning model is a fast, flexible, and accurate surrogate model to predict ion concentration profiles in nanoconfinement. [ABSTRACT FROM AUTHOR]

AbstractTemperature and voltage are critical operational parameters that significantly influence the efficiency of the electro-osmosis dewatering process. Despite their importance, there is a lack of comprehensive research to evaluate their combined effects on enhancing electro-osmotic dewatering process efficiency. In this study, mutual effects of temperature and voltage on electro-osmotic dewatering of tailings were investigated using numerical simulation. To validate the model, output data were compared with experimental results on thermal electro-osmotic dewatering of red mud. The results indicated that increase in temperature from 25 °C to 35 °C and 25 °C to 45 °C resulted in a 12% and 27% increase in electric current, and 25% and 50% increase in fluid outflow velocity, respectively. Additionally, electric current and fluid outflow velocity increased by about 50% and 100% for all considered temperatures when voltage increased from 10.5 V to 15.75 and 10.5 V to 21 V, respectively. Furthermore, the results proved that increase in temperature was more effective than voltage in enhancing Joule’s heating-induced dewatering. The study also revealed that increase in distance between electrodes by more than 1 m decreases the efficiency of electro-osmotic dewatering. [ABSTRACT FROM AUTHOR]

Nonlinear electrophoresis in complex fluids like nematic liquid crystals provides new pathways toward achieving precisely controlled motion and assembly of microscopic objects. The nematic host introduces a paradigm shift in the mechanism of electrophoretic transport by generating unbalanced electro-osmotic flows around the colloidal particle due to symmetry breaking of the medium caused by the induced topological defects. Rationally designed particles, which induce various types of defects and asymmetries, provide new opportunities in this regard. In this Perspective article, we discuss how the asymmetry in the shape and interfacial properties help in piloting the particles using an AC electric field. Finally, we propose some feasible strategies to achieve navigational control using magnetic and photo-responsive particles, guided by orthogonal electric, magnetic fields, and light, respectively. [ABSTRACT FROM AUTHOR]

Magnetohydrodynamics (MHD) have numerous engineering and biomedical applications such as sensors, MHD pumps, magnetic medications, MRI, cancer therapy, astronomy, cosmology, earthquakes, and cardiovascular devices. In view of these applications and current developments, we investigate the magnetohydrodynamic MHD electro-osmotic flow of Casson nanofluid during peristaltic movement in a non-uniform porous asymmetric channel. The effect of thermal radiation, heat source, and Hall current on the Casson fluid peristaltic pumping in a porous medium is taken into consideration. The effect of chemical reactions is also considered. The mass, momentum, energy, and concentration equations were constructed using the proper transformations and dimensionless variables to make them easier for non-Newtonian fluids. A lubricating strategy is used to make the system less complicated. The Boltzmann distribution of electric potential over an electric double layer is studied using the Debye–Huckel approximation. The temperature and concentration equations are addressed using the homotopy perturbation method (HPM), while the exact solution is determined for the velocity field. The study examines the performance of velocity, pressure rise, temperature, concentration, streamlines, Nusselt, and Sherwood numbers for the involved parameters using graphical illustrations and tables. Asymmetric channels exhibit varying behavior, with velocity declining near the left wall and accelerating towards the right wall while enhancing the Casson fluid parameter. The pumping rate boosts in the retrograde region due to the evolution of the permeability parameter value, while it declines in the augment region. The temperature profile optimizes as the value of the heat source parameter gets higher. The concentration profile significantly falls as the chemical reaction parameter rises. The size of the trapped bolus strengthens with a spike in the parameter for the Casson fluid. [ABSTRACT FROM AUTHOR]

The electro‐osmosis approach efficiently facilitates the rapid dewatering of soil with high water content and contributes to reducing contaminant levels within the clay soil. However, the changes of chemical field caused by ion transport in the clay soil during electro‐osmosis process will also influence the clay soil consolidation effect. Existing theories predominantly tend to disregard this crucial physical process and its resultant effects, thereby restraining a comprehensive analysis of electro‐osmosis consolidation (EOC) behavior under intricate chemical conditions. This study introduces a concise model of EOC and ion transport considering chemical osmosis. The model considers the nonlinear variation of clay soil parameters such as compressibility, permeability, and effective diffusion coefficients, along with the interaction between EOC and ion transport. Meanwhile, the correctness of the model is verified from different aspects such as theoretical derivation and model comparison. Based on the proposed model, the impacts of the variation in electrical field intensity and chemical concentration on the coupled behaviors between EOC and ion transport are systematically investigated, with and without incorporating nonlinear consolidation characteristics. The results show that diffusion and electro‐migration exhibit a more pronounced effect on ion transport during EOC. Simultaneously, with the increase of ion concentration in clay soil pore solution, the effects of chemical osmosis become increasingly apparent, thereby enhancing clay soil settlement. [ABSTRACT FROM AUTHOR]

The study of the complex rheological properties of viscoelastic fluids in nanochannels will facilitate the application of nanofluidics in biomedical and other fields. However, the flow of viscoelastic fluids in nanochannels has significant instabilities, and numerical simulation failures are prone to occur at high Weissenberg numbers (Wi). In this study, the simplified Phan-Thien-Tanner viscoelastic fluid model is solved using the log-conformation tensor approach, and the effects of rheological parameters of the viscoelastic fluid, such as the Weissenberg number (Wi), extensibility parameter (ε), and viscosity ratio (β), on the flow characteristics and flow instability within the nanochannel are investigated. The results indicate that the variation of rheological parameters of viscoelastic fluids has a significant effect on the flow state and flow instability of fluids in nanochannels. When the rheological parameters are in a specific range, the flow velocity and outlet current in the nanochannel exhibit relatively regular periodic fluctuations. As the flow transitions from an up-and-down moving single-vortex state to a symmetric double-vortex state, the average velocity of the central axis in the nanochannel is increased by about 15%. Furthermore, when Wi increases from 150 to 400, the length and height of the vortex increase by 50% and 100%, respectively. [ABSTRACT FROM AUTHOR]

The incorporation of induced charge into the serpentine curved micromixers driven by negative pressure (Np) can serve as an efficacious way for improving micromixing quality. To comprehensively investigate the hydraulic characteristics and mixing capacity of this model, an investigation is conducted using finite element method. The results indicate that when |−30| Pa ≤ Np ≤ |−50| Pa, active vortex pairs formed by electroosmosis flow on the conductive plate surface are fully developed, which strengthens the chaotic convection and leads to a uniform mixing. For |−50| Pa < Np ≤ |−200| Pa conditions, the compression of pressure flow causes the separation and degradation of active vortex pairs. However, increasing the electric field intensity around the conductive plate, such as forming a shrinking microchannel, or increasing the induction area of the plate, such as rotating the conductive plate, can make the active vortex play a beneficial role again, as both the Zeta potential and slip velocity on the plate surface are enhanced. For |−200| Pa < Np ≤ |−500| Pa conditions, the pressure flow gradually dominates the mixing process. But the conductive plate with combined optimal parameters can increase the mixing quality to above 0.8 when Np varies in border range. [ABSTRACT FROM AUTHOR]

The study investigates the heat and mass transfer of mixed peristaltic Casson fluid flow through a porous medium in the presence of electroosmosis. It uses the lubrication LWL-LRN analytical technique to transform flow-control equations into ordinary differential equations. The equation is simplified using a numerical solver, bvp4c, in MATLAB software. The study analyses the behaviour of momentum, thermal, solutal, and nanoparticle concentration using parameters such as the magnetic field parameter, porous, electroosmotic, Prandtl, thermal Grashof number, and solutal concentration. Comparing this work with the existing investigation reveals a high level of concordance regarding the impact of thermophoresis and Brownian variables on momentum fields. The study's novelty is the double-diffusive effects of Casson fluid, which provides a more accurate characterisation of its flow behaviour with convective boundary conditions over an inclined surface. Such observations are useful in real-life applications to capture the shear and stress-thinning properties and flow of synovial fluid in joints, as well as to understand blood flow in several physiological conditions. [ABSTRACT FROM AUTHOR]

The multiphase flow of Jeffery fluid under the impact of Magnetohydrodynamic is examined in this analysis. The nanoparticles of Hafnium metal are mixed up in the base fluid along with the impact of the electroosmotic phenomenon having a great significance in the present decade. Two different models, namely particulate and fluid phases, are considered for a convergent geometry with numerous usages in practical life, especially in modern technologies like microfluidic devices, chemical analysis, soil analysis, and other industries. The set of partial differential equations are converted into ordinary differential equations by using the non-dimensional quantities and obtained the exact solution of the resulting boundary value problem. The impact of physical parameters involving in the study is highlighted through graphs. To observe the flow pattern, the streamlines are also constructed. The Hartman number and Jeffrey fluid parameter slow down the velocity of fluid and particle phases. The Helmholtz-Smoluchowski parameter reduces the streamlines while the flow pattern remains unchanged via $ {U_{HS}} $ U HS . Moreover, the results are also compared with the previously published literature and noted excellent agreement with each other. The developed mathematical will be helpful in the diverse geometries used widely in medical and engineering walks to incorporate the fluid in complicated places like species separation, biomedical lab-on-a-chip devices, DNA sequences and stimulated drugs in diverse veins colliers, etc. [ABSTRACT FROM AUTHOR]

The transport process electroosmosis (EO) has been suggested to be used for dewatering damp brick masonry for decades. Still, it is debated whether EO can be obtained in bricks. By use of an advanced EO laboratory cell, this paper reports that an EO flow can be generated in two types of Danish bricks. The electroosmotic permeability coefficient was shown to be dependent on both intrinsic properties of bricks, such as pore size distribution, and extrinsic properties, such as zeta potential. Results showed that the brick with a higher pore volume but with a lower surface charge has a lower EO permeability coefficient. [ABSTRACT FROM AUTHOR]

[Objective] This study aims to investigate the physical properties of electroosmotic flow in protein nanopores using numerical simulations, particularly under varying electric field strengths and solution salt concentrations. This research is remarkable because electroosmosis is an efficient and controllable method for liquid transport, which is widely utilized in microfluidics, biomedical detection, chemical analysis, soil remediation, and water treatment, especially in high-throughput gene sequencing. By systematically examining the physical properties of nanoconfined electroosmotic flow, these applications can be optimized to enhance their performance and efficiency. However, owing to the challenges associated with nanoscale research, it is extremely difficult to directly measure the properties of electroosmotic flow in experiments. Therefore, employing theoretical and numerical simulation methods has emerged as an effective approach to address this issue. This study aims to gain a deeper understanding of the dynamic characteristics of electroosmotic flow in protein nanopores through numerical simulations, offering theoretical support and technical guidance for molecular separation and biomedical detection. [Methods] This study employed a coupled model of the Poisson-Nernst-Planck and Navier-Stokes equations to numerically simulate the electroosmotic flow in protein nanopores using the finite element method. This research focused on charged protein nanopores, considering the effects of varying electric field strengths and solution salt concentrations. The model was established by coupling the Poisson-Nernst-Planck and Navier-Stokes equations to obtain a mathematical representation of the nanopore system. The proposed model includes charged nanopores, electrolyte solutions containing free ions and water molecules, and external electric fields applied to both sides of the nanopore. [Results] The distribution of electroosmotic velocity and electric field strength within protein nanopores is highly uneven and substantially influenced by external potential and solution salt concentration. The specific findings are as follows: 1) Electroosmotic flow velocity distribution: in environments with high salt concentrations, the electroosmotic flow velocity considerably increases, particularly in the central region of the nanopores. The velocity profile of the electroosmotic flow along the z-axis exhibits nonlinear characteristics, with the velocity varying from the center to both ends of the nanopore. 2) Electric field intensity distribution: The electric field intensity is highest in the central region of the nanopore and shows notable nonuniformity in the surrounding areas. The electric field strength gradient greatly influences the distribution of electroosmotic flow velocity, with an increase in electric field strength leading to a substantial increase in the electroosmotic flow velocity in the central nanopore. 3) Salt concentration effect: As the salt concentration in the solution increases, the electroosmotic flow rate rises remarkably, and the velocity curve becomes steeper, particularly in the central nanopores, indicating that the electroosmotic flow rate is directly related to the ionic strength of the solution, with high salt concentrations promoting the passage of more ions through the nanopores under the influence of an electric field and enhancing electroosmotic flow. These findings deepen our understanding of the dynamics of electroosmotic flow at the nanoscale and provide a theoretical foundation for optimizing the performance of nanopore-based sensing and separation devices. [Conclusions] This study systematically investigated the electroosmotic characteristics of protein nanopores under varying potentials and salt concentrations using numerical simulations. Results indicate that the nonuniformity of electroosmotic flow velocity and electric field distribution is a key factor in determining electroosmotic flow characteristics. The electric field strength and solution salt concentration considerably affect the electroosmotic flow rate, with high salt concentration and electric field strength leading to a substantial increase in the flow rate within nanopores. By precisely controlling the electric field strength and distribution, the behavior of the electroosmotic flow can be effectively manipulated, which is crucial for optimizing the performance of nanopores in molecular separation and biomedical detection. These research findings offer deeper insights into the electrical properties within nanopores and underscore their potential applications in molecular separation and biomedical detection. In summary, this study offers theoretical support and methodological guidance for optimizing nanopore-based technologies, demonstrating notable application value. Future research can further explore the relationship between the structural characteristics and electroosmotic behavior of different protein nanopores, expanding their applications across various fields. [ABSTRACT FROM AUTHOR]

The primary aim of this study was to examine the peristaltic flow of an unsteady non-Newtonian TiO2 nanofluid through a uniformly symmetric channel under the influence of electro-osmosis. The fluid behavior was modeled by the Sutterby model. Furthermore, the flow took place through a porous medium, following a modified form of Darcy's law. Additionally, the impacts of Dufour and Soret effects, chemical reaction, activation energy, viscous dissipation, heat generation, and thermal radiation were considered. A wave transformation was used to simplify the governing equations describing the velocity, temperature, and nanoparticle concentration. These simplified equations were then solved analytically using the homotopy perturbation method. Additionally, set figures were employed to illustrate and discuss the impact of the physical parameters involved in the problem on the obtained solutions. It is found that the presence of a modified Darcy's medium in the Navier–Stokes equation results in a porous term that is dependent on the index of the Sutterby model. Furthermore, it is found that as the thermophoresis parameter increases, the nanoparticles are more concentrated, and their flow from the hot region to the cold region is more effective. Additionally, it is observed that in the presence of thermal radiation, the activation energy and the Brownian motion parameter have similar effects on the concentration profile. [ABSTRACT FROM AUTHOR]

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There are several applications for electro-osmotic MHD flow of hybrid Ferrofluid in the present era, notably in the biochemical as drug delivery systems, microfluidic devices, biomedical diagnostics, microscale systems and medical industries. The electro-osmotic MHD flow of a hybrid Ferrofluid containing Cobalt Ferrite, magnetite nanoparticles via a vertically inclined microchannel is investigated in this study. In furthermore, the perpendicular magnetic field is considered. Investigations are also carried into the effects of mass and heat transfer in this moving fluid. Partial differential equations provide as a representation for the aforementioned physical phenomenon, using suitable dimensionless nondimensional variables. Also, the classical system is fractionalized using the generalized Fourier and Fick's law. Generalizations are made based on the account of the Caputo derivative. The solution for the velocity, concentration, and temperature outlines is developed by using the Fourier and Laplace techniques. Moreover, the parametric impact of many physical factors as the Brinkman parameter, the temperature, velocity, concentration and stress parameters (Schmidt, Grashof, and Prandtl numbers). Graphs and discussions of concentration distributions is also discussed. The Sherwood number, rate of heat transmission, and skin friction are calculated and summarized. Since the fractional models are more accurate, they also provide a broader variety of possible solutions. Considering the relevant data, these solutions could be the best. Additionally, the heat transfer rate is higher as compare to nanofluid and regular fluid. The Hybrid Ferrofluid having capability to control velocity boundary layer rapidly as compare to nanofluid and regular fluid. [ABSTRACT FROM AUTHOR]

In view of the application plights of electroosmosis, a cyclic and progressive electroosmosis method (CPE) was proposed and verified using laboratory experiments. The electrifying mode and number of electrodes for CPE were evaluated by analysing the water discharge, current, shear strength, and water content of the soil after treatment. The results show that CPE can concentrate the water distributed in large areas to the predetermined electrode and improve the drainage efficiency of solely this electroosmosis method. After treatment, the shear strength and water content of the soil were significantly improved by CPE. Reducing the cyclic electrifying time and decreasing the number of electrodes appropriately was helpful in reducing the cracks and maintaining the drainage channels. [ABSTRACT FROM AUTHOR]

This paper explores the combined influence of an axial electric field and a perpendicular magnetic field imposed on rotating micro-parallel plates immersed in an electrolyte solution. A specialized computer program was developed to solve the velocity as well as the EDL potential fields using the finite difference method, employing the Debye-Hückel (DH) approximation to linearization the EDL potential. The study examines the influence of various non-dimensional parameters, including rotational speed (ω), Hartmann number (Ha), Debye-Hückel parameter (κ), and the non-dimensional parameter ' S', on axial, and transverse velocities, wall shear stress, and net flow rate. Results demonstrate that, both velocity components decrease with increased rotational speed and Hartmann number, while the net flow rate increases with the Debye-Hückel parameter for both rotating and non-rotating systems. The impact of these parameters on shear stress was also analyzed. Analysis of Ekmann spirals in the velocity plane revealed closed spirals at a higher rotational speed and open spirals at lower speeds, with spiral size reducing as rotational speed increases. [ABSTRACT FROM AUTHOR]

Immunoassays based on reactions between target pathogen (antigen; Ag) and antibody (Ab) are frequently used for Ag detection. An external magnetic field was used to immobilize magnetic microbeads-tagged-antibodies (mMB-Ab) on the surface of a microchannel in the capture zone. The mMB-Ab was subsequently used for Ag detection. The objective of this numerical study, with experimental validation, is to assess the surface reaction between mMB-Ab and Ag in the presence of electro-osmotic flow (EOF). First, immobilization of mMB-Ab complex in the wall of the capture zone was achieved. Subsequently, the Ag was transported by EOF toward the capture zone to bind with the immobilized mMB-Ab. Lastly, mMB-Ab:Ag complex was formed and immobilized in the capture zone. A finite volume solver was used to implement the above steps. The surface reaction between the mMB-Ab and Ag was investigated in the presence of electric fields (E): 150 V/cm–450 V/cm and Ag concentrations: 0.001 M–1000 M. The depletion of mMB-Ab increases with time as the E decreases. Furthermore, as the concentration of Ag decreases, the depletion of mMB-Ab increases with time. These results quantify the detection of Ag using the EOF device; thus, signifying its potential for rapid throughput screening of Ag. This platform technology can lead to the development of portable devices for the detection of target cells, pathogens, and biomolecules for testing water systems, biological fluids, and biochemicals. [ABSTRACT FROM AUTHOR]

Pumping fluid is one of the crucial parts of any microfluidic system. Using electric and magnetic fields as a substitute for moving parts can have many advantages. In this study hydrodynamic and heat transfer characteristics of electroosmotic flow under influence of lateral electric and transverse magnetic field, are studied numerically. Results indicate that the dimensionless parameters such as Hartmann number, intensity of the lateral electric field, pressure gradient parameter and aspect ratio have an important role in controlling flow. It can be implied that the enhancement of pressure gradient leads to the decrease of critical Hartmann number, and this dependency can be reduced from 44% to 7% for S = 0:5 to S = 50 in two pressure gradients of = 1 and = 20. In addition, the reduction of aspect ratio of microchannel section leads to the increment of critical Hartmann number in a specified lateral electric field. At the end, thermal analysis is being done by consideration of the effects of magnetic and electric fields on the Nusselt number. [ABSTRACT FROM AUTHOR]

The present study investigates electro-osmotically modulated peristaltic transport of third-grade fluid through a microtube taking into consideration the intricate coupling of zeta potential and hydrodynamic slippage. The analytical results encompass the mathematical expressions for dimensionless electrical potential distribution as well as series solutions for stream function and axial pressure gradient up to first order utilizing the perturbation technique for small Deborah number coupled with the Cauchy product for infinite series. Critical values and ranges of wavelength have been obtained where the axial pressure gradient vanishes. Moreover, pivotal values and ranges of wavelength have also been noted for the invariance of pressure gradient with respect to Deborah number as well as Debye-Hückel parameter. Trapping phenomenon has also been investigated by contours of streamlines wherein the zones of recirculation or trapped boluses are formed predominantly near the microtube walls. Additionally, the relative enhancement in hydrodynamic slippage amplifies the trapped bolus size, whereas a diminishing behavior on bolus size is observed by the electro-osmotic parameter. [ABSTRACT FROM AUTHOR]

[Display omitted] • Trace additive effectively extends the cycle life of ZIBs. • The adsorbed NTA molecules reduce the de-solvation energy barrier. • NTA molecules provide a buffer layer to retard dendrite growth. Aqueous Zn-ion batteries (AZIBs) have attracted widespread attention due to their intrinsic safety, cost-effectiveness. However, active H 2 O in the solvated ions [Zn(H 2 O) 6 ]2+ continuously migrate to the Zn surface to trigger hydrogen evolution reaction (HER) and accelerate Zn corrosion. Herein, Zn dendrites and the related by-products have been successfully inhibited by using trace amounts of Nitrilotriacetic acid (NTA). Theoretical research indicates that two carboxyl groups of NTA molecule strongly anchored on the Zn surface and exposed another carboxyl group outside. Due to the violent interaction of carboxyl groups of NTA with H 2 O, the de-solvation energy barrier of solvated Zn2+ ([Zn(H 2 O) 6 ]2+) on the Zn surface was obviously decreased, inhibit the active water splitting. Meanwhile, the preferential adsorption of NTA on the Zn surface increases the thickness of electric double layer EDL and provides a buffer layer to hinder the dendrite growth. Using 0.04 M NTA as additives in 2.0 M ZnSO 4 electrolyte, the cycling lifespan of both Zn||Zn symmetric and Zn||MnO 2 full cells is markedly prolonged. This study provides certain perspectives for trace amounts of electrolyte additives to satisfy the demand of long-cycle life AZIBs. [ABSTRACT FROM AUTHOR]

Existing solutions for electro‐osmotic consolidation assume a linear voltage distribution, which is inconsistent with the experimental findings. The present study introduces a novel two‐dimensional electro‐osmotic consolidation model for unsaturated soils, which considers the influence of non‐linear voltage distribution. The closed‐form solution is derived by employing the eigenfunction expansion method and the Laplace transform technique. The accuracy of the analytical solutions is validated through the implementation of finite element simulations. The findings from the parametric studies indicate that the excess pore water pressure (EPWP) observed in electro‐osmotic consolidation is influenced by the distribution of voltage. The dissipation rate of EPWP is observed to be higher when subjected to non‐linear voltage conditions compared to linear voltage conditions. Moreover, the impact of non‐linear voltage distribution becomes more pronounced in unsaturated soil characterised by higher electro‐osmosis conductivity and a lower ratio of kx/ky. In contrast, the excess pore air pressure (EPAP) remains unaffected by the voltage distribution. [ABSTRACT FROM AUTHOR]

The classical Helmholtz–Smoluchowski (HS) model of electroosmosis holds for homogeneously charged interfaces in contact with a fluid layer bearing an equal and opposite net charge. However, inhomogeneities in the surface charge and topography are inevitable, either as practical materials and fabrication artefacts, or at times as deliberately introduced modulations for flow control. In an effort to arrive at an analytically tractable theoretical framework for addressing the underlying electro-mechanical coupling, here, we generalize the traditional HS theory to an extent where both the surface charge and topographies may bear arbitrary and independent periodic forms. Using a spectral-asymptotic approach, we further arrive at closed-form expressions for describing the resulting electroosmotic pumping for topographic features with small characteristic amplitude to pattern period ratio, as relevant for most practical scenarios. We subsequently execute full-scale numerical simulations without any restrictions on the surface charge and topography variations to assess the efficacy of the theoretical framework. The corresponding test beds include distinctive signature patterns – for example, a square-wave surface charge distribution on trapezoidal pit topographies. Our results reveal that the charge–topography interplay induces an anisotropic flow drift, deviating from the classical HS paradigm. This, in turn, provides new quantitative insights into highly selective electroosmotic flow control via judicious design of the charge and topographical patterns, resulting in controllable accentuation, attenuation, nullification, deflection and even complete reversal of the flow. Our analysis further establishes a provision of estimating the zeta potentials of naturally 'contaminated' surfaces, as well as explaining the electrophoresis of large inhomogeneous particles; a paradigm that remained to be explored thus far. [ABSTRACT FROM AUTHOR]

Peristalsis of non-Newtonian nanofluid via a non-uniform conduit has several applications in physiology and industry. This study proposes a mathematical model as well as exploration of the impacts of entropy generation for peristalsis of magneto nanofluid with temperature-dependent thermal conductivity via an expanding asymmetric channel. Buongiorno's model for study of nanofluid flow has been adopted. Rheological aspects are accounted using the Carreau–Yasuda model due to its experimentally validated significance. Impacts of applied electric and magnetic fields have been taken into account. Thermophoresis, ohmic heating, viscous heating and Brownian motion effects are incorporated in the model. Numerical method is used via NDSolve in Mathematica after implementing the lubrication approach and Debye–Huckel linearization. The effects of embedded parameters on the flow, heat transfer, entropy generation and Bejan number are studied using graphical depictions. Outcomes indicate that a rise in electroosmotic parameter enhances heat transfer rate, whereas it reduces entropy generation and mass transfer rate at the boundary. Therefore, this study can provide basics to study nanofluidic systems which has applications in drug delivery. Increasing trends for temperature, heat transfer rate and entropy generation, while declining trends in the concentration of the particles are noted for higher joule heating. [ABSTRACT FROM AUTHOR]

A theoretical analysis of a multi-phase fluid problem is presented in this paper. Electro-osmotic flow with heat transfer in a divergent channel is modeled. Jeffrey fluid is taken as the base liquid, which suspends with the spherical gold particles. Electromagnetohydrodynamic (EHD) of a two-phase fluid through a porous medium is influenced by thermal radiation. Cumbersome mathematical manipulations leads to yield an exact solution for the set of strenuous differential equations. A comprehensive parametric study validates the accuracy and formidability of this intuitive analysis, by confirming the corresponding boundary conditions. The investigation articulately describes that the momentum of two-phase flow is supported by the Jeffrey fluid parameter. Additional golden particles increase the velocity of the base liquid. However, more thermal energy has contributed to the variation of the Brinkman number B R M . Finally, thermal energy expunges from the diverse channel due to Jeffrey's fluid parameter. [ABSTRACT FROM AUTHOR]

To improve the defects of low electroosmosis efficiency in the later stage and high energy consumption of conventional vacuum preloading combined with electroosmosis, the vacuum preloading-stepped electroosmosis method (VP-SEO) with prefabricated horizontal drain (PHD) was proposed for dredged sludge in this paper. In the test, waste concrete fine aggregate was used as the horizontal drainage cushion to alleviate the clogging of the PHD. The results showed that compared to vacuum preloading combined with electroosmosis (VP-EO), more drainage channels throughout the soil were produced after VP-SEO treatment, and VP-SEO could maintain a higher drainage efficiency in the later stage of treatment with improved final drainage and consolidation. The sludge treated by VP-SEO showed a significant increase in vane shear strength and a reduction in water content. Furthermore, the water loss and shrinkage of the soil surface after VP-SEO treatment were more uniform than that of VP-EO treatment, and the electroosmotic energy consumption and anode erosion were also lower. This study provides an effective improvement scheme for solidifying sludge with a high water content by conventional vacuum preloading combined with electroosmosis method. • The effectiveness and advantages of VP-HSEOA for sludge are explored by the model tests. • The sludge treated by VP-HSEOA can form a large number of drainage channels throughout the soil. • After VP-HSEOA treatment, water loss and shrinkage of the surface soil are more uniform. • VP-HSEOA has the advantages of deep reinforcement, low energy consumption, and less anode corrosion. [ABSTRACT FROM AUTHOR]

In dry-stack tailing ponds with high fine-grained content, a high long-term saturation line can lead to dam failure. Electroosmotic consolidation is an effective method for reducing dam saturation lines. However, traditional electrodes have low corrosion resistance and poor contact, which limits the development of electroosmotic drainage technology for tailings. In this study, an electroosmotic drainage device, an electrokinetic geosynthetic (EKG) electrode, was designed. The influence law of the electrode material, potential gradient, and number of electrodes on the water drainage, current, and resistance was analyzed. The results show that the EKG electrode has excellent corrosion resistance, with its weight loss after electroosmosis, water drainage, and equivalent allowable current being 1.67%, 122%, and ∼2.3 times that of a copper electrode, respectively. Furthermore, it was found that the optimal potential gradient was 1.2 V/cm, and the water drainage cannot be improved by an exceedingly high potential gradient. The current pathway in the test box was in parallel, and the water drainage increased to 410% and the contact resistance decreased by 83% when the number of electrodes was four. These results and novel methodology provide new ideas for EKG electrode design and represent an effective method for saturation line control in gold tailing ponds. • Study is beneficial for the application of EKG electrodes in tailings electroosmosis. • This study designed a new corrosion-resistant electrodynamic geosynthetic electrode. • An electroosmotic test device that can automatically collect data was created. • The performance of the EKG electrodes was compared with that of copper electrodes. • The variation of electroosmotic effect at different number of electrodes was studied. [ABSTRACT FROM AUTHOR]

Soil electrical conductivity has been extensively investigated in the fields of precision agriculture, geophysical mapping, and soil property mapping. However, the understanding of soil electro-osmotic conductivity is currently limited. Comprehensive insight into soil electro-osmotic conductivity is crucial for an accurately designing the electro-osmosis technique, which is widely accepted as a highly promising method for disposing soft soils with high water content. To fill this knowledge gap, a series of laboratory experiments was conducted using Hangzhou sludge. Four factors, including electrode material, potential gradient, soil water content, and pore water salinity, were investigated in terms of their influence on electrical conductivity of the electro-osmotically treated soil. Results show that during the electro-osmosis process, the soil electro-osmotic conductivity initially slightly increases and then decreases. The impact of electrode materials on soil electro-osmotic conductivity was minimal, whereas a high potential gradient was observed to generate low soil electro-osmotic conductivity. Furthermore, this conductivity was found to be linearly correlated with real-time water content. The slope of the correlation was also significantly influenced by the initial water content of the soil. Under different levels of pore water salinity, the soil electro-osmotic conductivity first increases to a peak and then decreases to a residual value. The soil electro-osmotic conductivity are observed to have a linear relationship with pore water salinity. These implications are closely linked to the soil conduction mechanism. Based on the foregoing findings, limiting the calculations to the pore water-induced conduction during the main stages of the electro-osmosis process is recommended. Furthermore, linear predictive relationships between soil electro-osmotic conductivity and the corresponding level of soil water content as well as between the soil electro-osmotic conductivity and the pore water salinity should be used in simplified calculation of the electro-osmosis process. The parameters involved in these relationships can be accurately determined through laboratory experiments. [ABSTRACT FROM AUTHOR]

For a long time, skim latex has been regarded as waste from the latex centrifugation process. To recover the rubber, skim latex is coagulated using strong acid due to the high presence of non-rubbers, resulting in products of low quality and unpleasant odour. Additionally, the acid discharged into effluent ponds causes malodour and adversely affects the health of nearby residents. Considering this, a novel method employing a membrane filtration system was utilised, successfully recovering and concentrating skim latex while removing water-soluble non-rubbers. The resulting latex concentrate was then compared to raw skim latex in terms of latex, colloidal, and film properties. Latex properties, namely total solids content (TSC), dry rubber content (DRC), alkalinity, nitrogen content, and gel content were determined. For the colloidal properties, particle size and distribution, zeta potential, and rheological properties (flow and viscoelastic behaviours), were characterised. The film properties assessed included the swelling index, appearance, and tensile properties. Significant improvements in latex properties after concentrating were observed, with both TSC and DRC increasing to 42% and 36%, respectively, while alkalinity, nitrogen, and gel contents decreased to 0.61%, 2.23%, and 54%, respectively. Particle size distribution in raw skim latex (RSL) exhibited a tri-modal distribution, but after membrane filtration, concentrated skim latex (CSL) showed a bi-modal distribution with particle sizes ranging from 0.03 to 0.3 µm and 0.3 to 5 µm and average sizes of 0.07 and 1 µm, respectively. Changes were also noted in zeta potential and rheological behaviour after membrane filtration. The isoelectric point of zeta potential shifted to a higher pH, from 4.2 for RSL to 4.9 for CSL, and the absolute zeta potential values decreased with increasing pH values. CSL also demonstrated a different flow behaviour, fitting well to the Herschel-Bulkley model, unlike RSL, which conformed to the Bingham model. Membrane concentration resulted in significant increases in CSL yield stress, consistency index, and shear thinning behaviour, leading to higher moduli values and indicating increased interaction between CSL particles. Conversely, CSL films prepared via casting swelled more in toluene, approximately two times more than RSL films. Nevertheless, RSL films were more opaque and only became transparent after leaching, indicating high non-rubber contents. Regarding tensile properties, both unleached and leached CSL films exhibited a similar tensile versus elongation profile, with ultimate tensile strength and elongation at break values ranging between 1.4 and 1.6 MPa and 650 and 700%, respectively. [ABSTRACT FROM AUTHOR]

Enhancing mixing efficiency in microscale processes for sensitive biomedical, pharmaceutical, and chemical applications is crucial, particularly when operating under low-velocity constraints. This study presents a comprehensive investigation into the impact of various factors on microfluidic mixing within a circular mixing chamber micromixer, utilizing electroosmotic principles. The governing equations are solved numerically using the finite element technique-based solver. This research examines the effects of microchamber diameter (D), inlet velocity (uo), alternating current (AC) voltage amplitude (ϕo), and AC frequency (f) on fluid mixing dynamics. Several key findings are noted from this study. The reduction of the circular microchamber diameter decreases the linear distance between cross-reciprocally placed microelectrodes, resulting in increased electroosmosis force and mixing efficiency. The voltage amplitude within the specified range shows increased mixing efficiency when fluid species are combined at appropriate velocity and AC frequency. The highest mixing efficiency of 98.84% is achieved with the following parameters: flow velocity (uo) of 150 μm/s, AC frequency of 4 Hz, voltage amplitude of 500 mV, and microchamber diameter of 20 μm. At a frequency of 12 Hz and voltage amplitude of 500 mV, the mixing efficiency exceeds 94.66% across a wide range of input velocities (100–200 μm/s), enabling versatile control in microfluidic devices. The nonlinear interaction between electroosmotic flow and microchamber geometry significantly contributes to this enhanced mixing efficiency. These results demonstrate the potential for optimizing microfluidic mixing processes through careful parameter tuning, particularly in applications requiring high efficiency at low flow rates. Thus, this study provides valuable insights for designing more effective microfluidic systems in various scientific and industrial fields. [ABSTRACT FROM AUTHOR]

This study investigates the physical characteristics of a two‐dimensional Jeffery fluid by incorporating the electroosmosis effect and employing slip boundary conditions along wavy walls. The equations that drive the flow analysis have been converted into nondimensional form and solved by assuming a high wavelength and a low Reynolds number approximation. The outputs for hemodynamic velocity, stress on the walls, and temperature for the flow are obtained exactly. Graphic representations of the effects of relevant physical parameters on the computational results are discussed in detail. Additionally, it is found that the viscous dissipation effects are the primary cause of heat production, rather than molecular conduction. [ABSTRACT FROM AUTHOR]

Electrokinetic remediation (EKR) has shown great potential for the remediation of in situ contaminated soils. For heavy metal-contaminated soft clay with high moisture content and low permeability, an electrokinetic remediation method with electrolytes placed above the ground surface is used to avoid issues such as electrolyte leakage and secondary contamination that may arise from directly injecting electrolytes into the soil. In this context, using this novel experimental device, a set of citric acid (CA)-enhanced EKR tests were conducted to investigate the optimal design parameters for Cu- and Zn-contaminated soft clay. The average removal rates of heavy metals Cu and Zn in these tests were in the range of 27.9–85.5% and 63.9–83.5%, respectively. The results indicate that the Zn removal was efficient. This was determined by the migration intensity of the electro-osmotic flow, particularly the volume reduction of the anolyte. The main factors affecting the Cu removal efficiency in sequence were the effective electric potential of the contaminated soft clay and the electrolyte concentration. Designing experimental parameters based on these parameters will help remove Cu and Zn. Moreover, the shear strength of the contaminated soil was improved; however, the degree of improvement was limited. Low-concentration CA can effectively control the contact resistance between the anode and soil, the contact resistance between the cathode and soil, and the soil resistance by increasing the amount of electrolyte and the contact area between the electrolyte and soil. [ABSTRACT FROM AUTHOR]

The effect of electrokinetic sodium silicate injection into sand formation containing fine grains was studied in this research. A soil was grouted by Na-silicate in a 160 mm length electrokinetic cell with a 1 V/cm potential gradient for 1 week. Silicate solutions of 5% and 10% concentrations were injected through the reservoir next to the anode electrode, while 10% phosphoric acid or 30 mg/l bicarbonate solutions were used in the cathode chamber. When comparing the results, it was evident that the electrokinetic (EK) process without additives does not significantly enhance soil strength, except in the vicinity of the cathode electrode. Specifically, the most notable increase in strength was observed in the section proximal to the cathode, which demonstrated approximately 3.1 times higher strength than the control sample (i.e., without EK application). The obtained results indicate that injecting 5% and 10% Na-silicate solutions significantly increase the strength of soil all over the sample. Significant improvement in soil strength was observed when Na-Si was injected with bicarbonate as a catholyte during the EK process. Strength at the anode increased by 82% and 107% at 5% and 10% Na-Si concentrations, respectively. Resistance in the middle of the cell samples remained consistent for both concentrations. Immediate application of bicarbonate catholyte and silicate injection notably enhanced soil strength, while efficiency decreased when Na-Si was injected with phosphoric acid catholyte, especially near the cathode. Higher silicate concentrations resulted in reduced penetration length in both acid and bicarbonate catholytes. It can also be concluded that adding silicate to the anode chamber meaningfully reduces the electro-osmotic flow after 2 or 3 days. [ABSTRACT FROM AUTHOR]

Insulator-based electrokinetically driven microfluidic devices stimulated with direct current (DC) voltages are an attractive solution for particle separation, concentration, or isolation. However, to design successful particle manipulation protocols, it is mandatory to know the mobilities of electroosmosis, and linear and nonlinear electrophoresis of the microchannel/liquid/particle system. Several techniques exist to characterize the mobilities of electroosmosis and linear electrophoresis. However, only one method to characterize the mobility of nonlinear electrophoresis has been thoroughly assessed, which generally requires DC voltages larger than 1000 V and measuring particle velocity in a straight microchannel. Under such conditions, Joule heating, electrolysis, and the DC power source cost become a concern. Also, measuring particle velocity at high voltages is noisy, limiting characterization quality. Here we present a protocol—tested on 2 μm polystyrene particles—for characterizing the mobility of nonlinear electrophoresis of the liquid/particle system using a DC voltage of only 30 V and visual inspection of particle dynamics in a microchannel featuring insulating obstacles. Multiphysics numerical modelling was used to guide microchannel design and to correlate particle location during an experiment with electric field intensity. The method was validated against the conventional characterization protocol, exhibiting excellent agreement while significantly reducing measurement noise and experimental complexity. [ABSTRACT FROM AUTHOR]

Electrokinetic convection-enhanced delivery (ECED) utilizes an external electric field to drive the delivery of molecules and bioactive substances to local regions of the brain through electroosmosis and electrophoresis, without the need for an applied pressure. We characterize the implementation of ECED to direct a neutrally charged fluorophore (3 kDa) from a doped biocompatible acrylic acid/acrylamide hydrogel placed on the cortical surface. We compare fluorophore infusion profiles using ECED (time = 30 min, current = 50 µA) and diffusion-only control trials, for ex vivo (N = 18) and in vivo (N = 12) experiments. The linear intensity profile of infusion to the brain is significantly higher in ECED compared to control trials, both for in vivo and ex vivo. The linear distance of infusion, area of infusion, and the displacement of peak fluorescence intensity along the direction of infusion in ECED trials compared to control trials are significantly larger for in vivo trials, but not for ex vivo trials. These results demonstrate the effectiveness of ECED to direct a solute from a surface hydrogel towards inside the brain parenchyma based predominantly on the electroosmotic vector. Electrokinetic Convection-Enhanced delivery was implemented to direct macro-molecule infusion into the brain from a hydrogel reservoir through electroosmosis, in ex vivo and in vivo rat brain models. [ABSTRACT FROM AUTHOR]

Silicon‐on‐insulator (SOI) based photonic sensors, particularly those utilizing Photonic Integrated Circuit (PIC) technology, have emerged as promising candidates for miniaturized bioanalytical devices. These sensors offer real‐time responses, occupy minimal space, possess high sensitivity, and facilitate label‐free detection. However, like many biosensors, they face challenges when detecting analytes at exceedingly low concentrations due to limitations in mass transport. An intriguing method to enhance mass transfer in microfluidic biosensors is AC electrokinetics. Proof‐of‐concept experiments have demonstrated significant enhancements in limit of detection (LOD) and response times. AC electrokinetics, compatible with silicon photonic sensors, offers techniques such as electroosmosis, electrothermal effects, and dielectrophoresis to modify fluid flow and manipulate particle trajections. This article delves into various approaches for integrating AC electrokinetics into silicon photonic biosensors, shedding light on both its advantages and limitations. [ABSTRACT FROM AUTHOR]

• Electroosmosis in a poultice of kaolinite mixed with tap water has a higher EO flow rate than the poultice with calcium carbonate. • By increasing the concentration of calcium carbonate in the poultice of kaolinite, the EO flow rate decreases. • The EO flow stops when the calcium carbonate concentration increases to 80 % and 20 % of kaolinite in the poultice mixture. • The increase in ionic strength has a negative effect on EO flow. Electrokinetic treatment of masonry for desalination or electroosmotic dewatering depends on a poultice, in which the electrodes are placed, which fulfills several purposes. Poultice composed of kaolinite and CaCO 3 have been shown to have good workability and high pH buffering capacity. In this work, the electroosmotic (EO) permeability is studied in different kaolinite - CaCO 3 mixtures. In addition, the effect on EO of using NaCl as a mixing solution is investigated. A special cell is used to test the EO in the specimens. A phenomenological approach, based on the potential gradient and the flux of solution, was used to calculate the EO flow rate and EO permeability coefficient. Results showed that by increasing the concentration of CaCO 3 in the poultice mixture, the EO flow rate decreased and the poultice with 80 % CaCO 3 and more did not have any EO flow. Furthermore, the ionic strength in the mixing solution decreases the EO flow rate. [ABSTRACT FROM AUTHOR]

Electronic paper displays rely on electrokinetic effects in nonpolar solvents to drive the displacement of colloidal particles within a fluidic cell. While Electrophoresis (EP) is a well-established and frequently employed phenomenon, electro-osmosis (EO), which drives fluid flow along charged solid surfaces, has not been studied as extensively. We hypothesize that by exploiting the interplay between these effects, an enhanced particle transport can be achieved. In this study, we experimentally investigate the combined effects of EP and EO for colloidal particles in non-polar solvents, driven by an electric field. We use astigmatism micro-particle tracking velocimetry (A- μ PTV) to measure the motion of charged particles within model fluidic cells. Using a simple approach that relies on basic fluid flow properties we extract the contributions due to EP and EO, finding that EO contributes significantly to particle transport. The validity of our approach is confirmed by measurements on particles with different magnitudes of charge, and by comparison to numerical simulations. We find that EO flows can play a dominant role in the transport of particles in electrokinetic display devices. This can be exploited to speed up particle transport, potentially yielding displays with significantly faster switching times. Interplay of electrokinetic effects : Driven by the applied electric field, both electro-osmosis (EO, top left), which drives a flow along the surfaces of the fluidic cell, and electrophoresis (EP, top right), which drives a migration of particles relative to the background liquid, occur in our system. A typical example of the resultant particle velocity field (bottom) illustrates the important role of EO on particle transport in the fluidic cell. • Studied electrokinetics of particles in nonpolar solvent using astigmatism micro-PTV. • Both electrophoresis (EP) and electro-osmosis (EO) play important roles. • Combination of EO and EP could be exploited in faster switching e-paper displays. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the electro-osmotic flow (EOF) and mass transfer of a Newtonian fluid propelled by a pressure gradient and alternating current (AC) electric field in a parallel microchannel with sinusoidal roughness and modulated charged surfaces. The two-wall roughness is described by in-phase or out-of-phase sine functions with a small amplitude δ. By employing the method of perturbation expansion, the semi-analytical solutions of the Poisson–Boltzmann (P–B) equation based on the Debye–Hückel approximation and the modified Navier–Stokes (N–S) equation are obtained. The numerical solution of the concentration equation is obtained by the finite difference method. The effects of sinusoidal roughness, modulated charged surface, and the AC electric field on the potential field, velocity field, and concentration field are discussed. Under the influence of the modulated charged surface and sinusoidal roughness, vortices are generated. The velocity oscillates due to the effect of the AC electric field. The results indicate that solute diffusion becomes enhanced when the oscillation Reynolds number is below a specific critical value, and it slows down when the oscillation Reynolds number exceeds this critical value. [ABSTRACT FROM AUTHOR]

This study investigates the electro-osmotic flow of a biological fluid (blood with varying cholesterol levels) in annular flow to simulate a first approximation to arterial occlusion. The fluid´s rheology is characterized by amulti-modal convectedMaxwell model equation. The charge density follows the Boltzmann distribution, governing the electrical field. Mathematically, this scenario can be modeled by the Poisson–Boltzmann partial differential equation. Assuming a small zeta potential (less than 25mV) using the Debye–Huckel approximation and considering a pulsatile electrical field, analytical solutions are derived using the Fourier transform formalism. These solutions, expressed in terms of the modified Bessel function, provide transfer functions for axial velocity and volumetric flow as functions of material parameters represented by characteristic dimensionless numbers. This study further analyzes thermal, electric, inertial, viscoelastic, and various interactions within the plasma, hematocrit, hematocrit–cholesterol, and cholesterol–cholesterol as well as weight concentration through numerical simulations. Finally, the flow and rheology predictions are validated using experimental data on human blood with varying cholesterol levels. The obtained transfer functions reveal that the electric–thermal–viscoelastic effects and the multiple geometric relationships contribute to the dynamic response of the interactions between the input electrical field and output volumetric flow and shear stress functions, leading to and evolution of resonance curves. It is noteworthy that electro-osmotic flow in blood with pathologies associated with low and high cholesterol has been scarcely reported in the literature on rheology. Thus, this work represents a significant contribution to the field. [ABSTRACT FROM AUTHOR]

Concentration-polarization electroosmosis (CPEO) refers to steady-state electroosmotic flows around charged dielectric micro-particles induced by low-frequency AC electric fields. Recently, these flows were shown to cause repulsion of colloidal particles from the wall of a microfluidic channel when an electric field is applied along the length of the channel. In this work, we exploit this mechanism to demonstrate fractionation of micron-sized polystyrene particles and bacteria in a flow-focusing device. The results are in agreement with predictions of the CPEO theory. The ease of implementation of CPEO-based fractionation in microfluidics makes it an ideal candidate for combining with current techniques commonly used to generate particle lift, such as inertial or viscoelastic focusing, requiring no extra fabrication steps other than inserting two electrodes. [ABSTRACT FROM AUTHOR]

The present numerical investigation uncovers the flow, heat, and mass transfer of ethylene glycol-based nanofluid (BN-EG) led by the combined impacts of peristaltic pumping and electroosmosis. The thermal conductivity of carrier liquid is deemed to change with temperature. Further, the features of electric field, Ohmic heating, radiative heat flux, mixed convection, and magnetic field are taken. Mathematical modeling is conducted under the assumption of lubrication theory. The nonlinear-coupled equations are addressed numerically by implementing Shooting method. The effective results of all physical constraints linked with the flow model are vigilantly studied and highlighted through various curves. The observations obtained from current analysis reveal that temperature augments with higher electroosmotic parameter. However, the Joule heating parameter increases the rate of heat transmission, while a lower rate of heat transfer is perceived for the radiation parameter. An increment in Helmholtz–Smoluchowski velocity increases the velocity profile. Pressure gradient rises in a forward way when electrical field favors peristaltic flow. Concentration of nanomaterial considerably declines when concentration Grashoff number is assigned higher values. [ABSTRACT FROM AUTHOR]

This paper thoroughly examines the complex dynamics of non-Newtonian electro-osmotic flow (EOF) across micro-parallel plates, which is crucial for the advancement of micro-fluidic technology. Our research focuses on investigating the effects of Joule heating and exothermic reactions on flow characteristics and temperature distributions in these systems. The Debye-Hückel approximation and a Nahme-type law are employed to, respectively, model the Poisson-Boltzmann body force and temperature-dependent fluid viscosity. Efficient and robust computational algorithms based on the finite difference methods (FDM) are implemented to obtain the numerical solutions. The solutions are qualitatively discussed, highlighting the sensitivity to variations in various embedded flow parameters. The results of our study demonstrate that the combination of Joule heating and exothermic reactions significantly influences the electro-osmotic flow (EOF), resulting in major variations in fluid velocity and temperature distributions. [ABSTRACT FROM AUTHOR]

Many physiological ducts, like sperm vessels, intestines, common bile ducts, ducts of salivary glands, and ducts in the repertory system, are common ducts in which transport occurs due to the propagation of complex waves on the boundary. Electroosmotic flow phenomena are significant in membrane separation processes, protein and peptide delivery, iontophoresis in drug delivery through physiological ducts, and a lot of application in plant physiology regarding pressure control in xylem and phloem vessels. The aim of this theoretical study is to analyze the thermal characteristics of physiological fluid characterized by the Carreau-Yasuda model in a complex wavy channel. The two agents of flow, i.e., the propagation of complex waves on the walls of the channel and the electric field in the axial direction, are considered. Different zeta potentials at both walls of the asymmetric channel are employed. Basic conservation laws, along with the Poisson-Boltzmann equation, are utilized to model the problem in the Cartesian coordinate system. Theoretical and biological assumptions like greater wavelength, lubrication transport, and Debye-Hückel linearization transform the governing equations of PDE into a coupled system of ODE. The shooting method is used, which is Solve, a built-in function in the computational software Mathematica to compute the stream function, temperature profile, concentration profile, and various flow and heat transfer characteristics. The impact of various penetrating parameters is described through plots. The magnitude of the velocity profile is increased near the center of geometry by increasing the electroosmotic parameter in the lower half of the regime. Then the Sherwood number and the Bejan number show enhanced behavior by increasing the electroosmotic parameter. The current analysis predicts dynamic applications in thermodynamical systems, cooling systems, biochemistry, and drug delivery systems. [ABSTRACT FROM AUTHOR]

This paper investigates the behavior of magnetohydrodynamic (MHD) peristaltic flow with electroosmosis. The Jeffrey fluid in microchannel under the influence of homogeneous-heterogeneous chemical reaction has been taken. The heat absorption and nonlinear radiation are also scrutinized here. This study contributes to the fundamental understanding of complex fluid dynamics in microscale systems and offer valuable insights for designing and optimizing microfluidic devices. In the framework of mathematical simulation, the relevant dimensional nonlinear equations are reduced into dimensionless equations by using linear transformations. Thus Debye-Hückel linearization has been employed. The streamline approach with mathematical modelling has been performed within the limits of δ≪1 and Re→0. The appropriate equations for temperature and concentration with boundary conditions are solved by using perturbation approach whereas, the exact solution is found for velocity equation. A graphical depiction of crucial physical characteristics on velocity, temperature, concentration and streamlines are reported in the last section. It is observed that the velocity distribution decreases for the higher value of M (0.5≤M≤2) however, it increases for the escalating values of Uhs (−0.5≤Uhs≤1.5). When Rn(0.1≤Rn≤0.6) gets stronger then temperature profile decreases. It is noticed that the concentration profile decays owing to enhancement in Sc(−0.5≤Sc≤1.5). As the M (0.5≤M≤2) increases, the size of trapped bolus decreases. Escalating values of temperature ratio parameterθw(1.0≤θw≤1.6)enhances the Nusselt number. The novelty of this study lies in the comprehensive analysis of multiple complex phenomena in a single framework. The interplay between MHD electroosmotic flow, homogeneous heterogeneous chemical reactions, peristalsis, nonlinear thermal radiation, heat absorption and no-slip condition has not been explored in previous research.

Proton exchange membrane (PEM) electrolysis is widely considered an integral part of the energy transition. Thinner membranes can reduce Ohmic losses and increase efficiency. However, hydrogen crossover limits the use of thinner membranes. For the first time, this review provides a comprehensive overview of both model and experimental works on hydrogen crossover and crossover mitigation. By combining the experimental data and state-of-the-art models, we discuss the recent progress in understanding crossover mechanisms. The dominant mechanism for hydrogen crossover is the diffusion driven by both the high hydrogen partial pressures at the cathode and supersaturation in the catalyst layer due to transport limitations. The reviewed models successfully reproduce the experimental data obtained by different groups. A variety of strategies for including recombination catalysts in the cell are currently investigated in academic and corporate research. Some of these show promising results with potential for near-term industrial application. • H 2 crossover conventionally limits the use of thin membranes in PEM electrolysis. • Supersaturation and electroosmotic water drag can significantly affect gas crossover. • Mechanistic crossover models describe various experimental results accurately. • Recombination catalysts mitigate safety issues associated with H 2 crossover. • Multiple approaches for including recombination catalysts in MEAs are promising. [ABSTRACT FROM AUTHOR]

We study the Cauchy problem of the new model of the three dimensional inertial nematic electrolyte, which models the N-species charged particles diffuse and advect in the nematic liquid crystalline matrix. This new model was proposed by [Calderer MC, Golovaty D, Lavrentovich O, et al. Modeling of nematic electrolytes and nonlinear electroosmosis. SIAM J Appl Math. 2016;76:2260–2285. doi: 10.1137/16M1056225]. The inertial effect is such that the system involves a hyperbolic feature. We first derive the local existence in large initial data when the flow is isotropy, i.e. $ \lambda =1 $ λ = 1. For the anisotropy case ( $ \lambda \gt 0 $ λ > 0 , $ \lambda \neq ~1 $ λ ≠ 1), we obtain small data local solutions. Then, by seeking some further dissipative mechanisms from the elliptic structures, the local solution can be extended globally near the constant states with electro-neutrality condition. [ABSTRACT FROM AUTHOR]