System integration journal of biological engineering. We will now discuss two closely related phonemona, electrophoresis and electroosmosis, which are given rise by. Additionally, the phenomena we have uncovered could potentially be harnessed in novel microfluidic applications, whose technological implications range from labonachip devices to personalised medicine. Multiphysics modeling with finite element methods series. A piezoelectric bimorph actuator glued to the chamber allows the release of an aqueous drop on demand in the horizontal channel. The code is used to solve several standard cases of the onedimensional relativistic plasma physics problem, and the results are compared with analytical solutions as well as pic simulations. Despite their apparent simplicity, systems involving one or two electri. Zeta potential is a scientific term for electrokinetic potential in colloidal dispersions. Transient analysis of electroosmotic secondary flow. Nonlinear electrokinetic phenomena mit mathematics. The movement of charged colloidal particles in electric field is termed electrophoresis.
Zeta potential is a very important interfacial electrokinetic property to a huge number of natural phenomena, such as electrode kinetics, electrocatalysis, corrosion, adsorption, crystal growth, colloid stability and flow characteristics of colloidal suspensions and electrolyte solutions through porous media and microchannels. Microfluidics is capable of analyzing small sample volumes 10. This allows us to investigate the limitations of the traditional description of these phenomena, which relies on the meanfield poissonboltzmann theory of the electric double layer and continuum hydrodynamics for the flow fields. This mobilizes charged species, causing ions and water to move toward the electrodes. Effect of the flow state on streaming current kuwano. Us7399398b2 variable potential electrokinetic devices. Sir physical chemistry of surface by arthur adamson in pdf and physical chemistry by stephen bery in pdf please provide. This document connects the nanoobject parameters that most commonly need to be measured with corresponding measurement techniques. The phenomena involved in the limiting region are not yet fully understood. Im putting out there the suggestion to merge the two articles. Electrokinetic phenomena izmir yuksek teknoloji enstitusu. The modelling of networks of long channels that merge at a yjunction incorporates simultaneous algebraic constraints for the long channels 0d as coupled boundary conditions to the 2d yjunction.
View notes linear electrokinetic phenomena notes from chem 1211k at georgia state university. Electrokinetic phenomena of cationized cotton and its dyeability with reactive dyes article pdf available in fibres and textiles in eastern europe 216102. Combining equations 401 and 404, one can derive the. Electrokinetic flows belong to a wider class of phenomena referred to as electrokinetic ek effects, which cover all possible couplings between different types of transport, i. The radial extent of the annular layer is assumed to be small in comparison to the cylinder radius and this, along with the assumption of thin dimensionless debye layers, is used to derive a nonlinear evolution equation for the interfacial dynamics. Classically, the electric force used to drive fluid flow, and particle motion. The influence of charged gel layers on the electrokinetic. Electrokinetic and colloid transport phenomena wiley. Us7399398b2 us10788,629 us78862904a us7399398b2 us 7399398 b2 us7399398 b2 us 7399398b2 us 78862904 a us78862904 a us 78862904a us 7399398 b2 us7399398 b2 us 7399398b2 authority. This chapter explores the multiphysics modeling appropriate for electrokinetic flow in microchannel networks. The electrical double layer and electrokinetic phenomena. In fact, the details of interfacial interactions are usually neglected due to the already considerable computational expense of simulating the. A new, definitive perspective of electrokinetic and colloid transport processes responding to renewed interest in the subject of electrokinetics, electrokinetic and colloid transport phenomena is a timely overview of the latest research and applications in this field for both the beginner and the professional. The solutions obtained are asymptotically correct for the general set of electrohydrodynamic equations.
Kwok and kostiuk derived this concept from surface thermodynamics, and built the prototype to test an idea for a new type of energy conversion device. Ac electrokinetic phenomena use electric fields to generate forces that act on fluids or suspended particles including those made of dielectric or biological material and cause them to move in astonishing ways 1, 2. Applications of electrokinetic phenomena in materials science. This electrokinetic battery doesnt create energy, it just converts it from one form to another.
Electrokinetic phenomena are related to the presence of an electrical double layer edl. Research, development, test and evaluation, defensewide defense advanced research projects agency volume 1 missile defense agency volume 2 office of the secretary of defense volume 3 chemical and biological defense program volume 4 u. Both methods are suited for performing complex, multistep analysis or synthesis 4, 21. Electrokinetic phenomena generally refer to the tangential motion of liquids with respect to charged solid surfaces, and the measurement of these phenomena provide important information on the structure of electrical double layers 29, 30. Electroosmosis and electrophoresis are the electrokinetic phenomena of the first type. The new edition of this classic text offers a comprehensive and accessible introduction to electrochemistry. Electrokinetic effects occur in the presence of an interfacial double layer of charges.
Pdf molecular views of electrokinetic phenomena researchgate. Microfluidics holds great promise to revolutionize various areas of biological engineering, such as single cell analysis, environmental monitoring, regenerative medicine, and pointofcare diagnostics. The history of electrokinetic phenomena request pdf. Electrokinetic phenomena have proved to be useful nonequilibrium phenomena as compared. The effects of the charged gel layer on the electrokinetic phenomena are investigated. In addition, there are analogous phenomena for freely suspended charged colloidal particles, such as electrophoresis and sedimentation potential see sections 3. Pdf the molecular nature of electrokinetic phenomena is examined using. This document will be a useful tool for nanotechnology interested parties to rapidly identify relevant information for measuring nanoobjects. Study of quorum sensing and quorum quenching phenomenas in wastewater treatment using. Wellknown phenomena of this kind are electrophoresis, electro. Electrokinetic phenomena synonyms, electrokinetic phenomena pronunciation, electrokinetic phenomena translation, english dictionary definition of electrokinetic phenomena. Measurement and interpretation of electrokinetic phenomena. Some drawbacks of digital microfluidics in its current state are presented by fair in 4, such as the need to use conductive liquids. This textbook offers an introduction to multiple, interdependent transport phenomena as they occur in various fields of physics and technology like transport of momentum, heat, and matter.
Also the segmented flow technique has been developed. Manual of symbols and terminology for physicochemical uantities and units, appendix ii. Fluid physics around conductive deformable flaps within an. Many studies have been conducted to improve the electrokinetic removal ef. Electrokinetic mixing in microfluidic systems, microfluids. Twophase flow in microchannels with surface modifications. Us6719535b2 variable potential electrokinetic device. Dynamics and stability of an annular electrolyte film. About zeta potential libzeta zeta library zeta for windows zeta command line zeta for dos history file formats license gnu gpl authors homepage feedback about zeta potential electrokinetic phenomena. The behaviour of the ek coefficient in unsaturated conditions is a debated question which is the topic of numerous studies.
Bazant departments of chemical engineering and mathematics, massachusetts institute of technology, cambridge, ma 029 usa abstract this chapter provides an introduction to a certain class of. Stagnation point concept is used to explain the behavior of the flap at different situations. Electrokinetic effects counter ions charged colloid electrophoresis adsorbed ions movement due to electrophoresis electro osmosis of counter ions surfaces i. The merger of microfluidics and advanced biosensor technologies. Derksena adepartment of chemical and materials engineering, university of alberta, edmonton, alberta, canada bdepartment of mechanical engineering, lassonde school of engineering, york university, toronto, canada abstract collisions of charged droplets in the shear.
The venerable theory of electrokinetic phenomena rests on the hypothesis of a dil. Electrokinetic phenomena an overview sciencedirect topics. Electrokinetic phenomena in a suspension of liquid drops are different from those of rigid particles. It is increasingly realized that an effective system. An electrokinetic lb based model for ion transport and macromolecular electrophoresis. The region containing the double layered is sheared at some distance from the solid surface creating a thin film associated with the solid. Electrokinetic phenomena have proved to be useful non equilibrium phenomena as. Parks 3 has compiled the pristine pzc of metal oxides and. We will consider them separately deriving the equations and eventually merge them. Studying shear and discharge rate of proteins in microfluidic junctions, under electrokinetic effects babak kamali doust azad department of mechanical engineering, iran university of science and technology, iran email. This electrokinetic phenomenon is a favorable tool to induce flows in microstructures without applying a pressure gradient or the usage of micromechanical parts.
As the vortices grow in size they merge and the wavelength is. Us6719535b2 us10066,528 us6652802a us6719535b2 us 6719535 b2 us6719535 b2 us 6719535b2 us 6652802 a us6652802 a us 6652802a us 6719535 b2 us6719535 b2 us 6719535b2 authority us u. Electrokinetic phenomena result from the differential movement of two phases where the interface is an electrical double layer. Interfacial electrokinetic transport phenomena and their. Simulations of charged droplet collisions in shear. Electrokinetic phenomena are observed on the interface of two interacting phases, such as a solid, which is in contact with a liquid. Ac electrokinetic phenomena generated by microelectrode. Therefore, determintion of the pzc is an important element of the characterization of commercial adsorbents. The electrokinetic phenomena were characterized by microparticle image. Electrokinetic phenomena in pencil leadbased microfluidics mdpi. Phenomena that arise include conduction, potential. Pdf electrokinetic phenomena of cationized cotton and its. Therefore, electrokineticbased microfluidic systems can serve as a viable tool in creating a labonachip loc or micrototal analysis system. Optimization of an electrokinetic mixer for microfluidic.
Processes that depend critically on these phenomena in. Experimental set up for measuring electrokinetic properties. Electrokinetic phenomena provide many popular nonmechanical techniques in micro. Following that, electrokinetic phenomena with a detailed description of the electrokinetic theory and its role in. They assumed for this, that the bubbles decrease much less the water flow streaming current than they. The novelty is examined by combining several preconcentration techniques with a gel. Typical in situ electrokinetic separation system the principle of electrokinetic remediation relies upon application of a lowintensity direct current through the soil between ceramic electrodes that are divided into a cathode array and an anode array. The phenomena appear when an external force produce a tangential motion of fluid, liquid electrolytes, with respect to an adjacent charged surface. Ppt electrokinetic phenomena powerpoint presentation free. It is a very important interfacial property for a large number of natural phenomena, for example electrode kinetics, electrocatalysis, corrosion, adsorption and colloidal. These effects govern the translocation process, and thus have consequences for better control of single molecule sensing.
Numerical investigation of the effect of twodimensional. Chapter 3 the electrical double layer and electrokinetic phenomena author links open overlay panel d. A new document is already prepared and has been distributed to the members of the working party. The electrokinetic phenomena were characterized by micro particle image. The utilization of electrokinetic phenomena to improve mixing in microflows is described by several authors and, in principle, two different approaches are identified in literature. Electrokinetic phenomena for an enhanced understanding of ongoing atomic force microscopy afm measurements, i have been working on the numerical modeling of the afm tip 5nm interacting with a flat substrate immersed in an ionic solution.
Amplified electrokinetic response concentration polarization near. Despite the fact that intensive efforts have been devoted into the field in the past decades, microfluidics has not yet been adopted widely. Lecture linear electrokinetic phenomena notes by mit student and mzb 1 linear electrokinetic resonse of a nanochannel 0 3 we start with the system in equilibrium q 0 i 0. Generally, electrokinetic phenomena electrically driven liquid. Journal of colloid and interface science 309 2007 194224 1. Electrokinetic phenomena ess5855 lecture fall 2010 introduction the word electrokinetic implies the combined effects of electrical and motion specifically, our interest centers on those phenomena in which a relative motion exists between two parts of the electrical double layer this may arise from the migration of a. An electrokinetic lb based model for ion transport and. Efficient electrokinetic phenomena provided by the 3d electrodes, including. Pdf measurement and interpretation of electrokinetic phenomena. Electrokinetic phenomena definition of electrokinetic.
These phenomena are found in a number of combined processes in the fields of chemical, food, biomedical, and environmental sciences. Drop on demand in a microfluidic chip institute of physics. The phdependent surface charging and points of zero. The term heterogeneous here means a fluid containing particles. Investigating the transient phenomena of electroosmotic. A coupling strategy for nonlocal and local di usion models. Therefore, electrokineticbased microfluidic systems can serve as a viable tool in creating a labonachip loc. Welcome to the web page of the international symposium on electrokinetic phenomena. The discovery of electrokinetic phenomena by reuss in 1808 and further investigations that gave rise to the concept of the electrical double layer have played an important role in the understanding of colloidal stability. The electrophoretic velocities of gelatin, eggalbumin, and gliadincovered quartz particles in various alcoholwater solutions are, within the limits employed in usual experimental procedures, proportional to the field strength. It assumes a background in chemical thermodynamics and kinetics at the level of a standard undergraduate physical chemistry course, and it is intended for use as a text for a first course in electrochemistry or as a selfstudy book for chemists and scientists in related fields.
Electrokinetic phenomena ekp can be loosely defined as all those. In practice, they are often the only source of infor. Electrokinetic devices generally require no external mechanical moving parts and can be made portable by replacing the power supply by small battery. A few years later, the present authors pointed out that the underlying physical mechanism of an electric. Therefore, electrokinetic based microfluidic systems can serve as a viable tool in creating a labonachip loc or micrototal analysis system. Electrokinetic phenomena couple electrical flow and hydraulic flow revil et al. The elkin is a forum for the discussion of new advances in theoretical and applied electrokinetics. Research, development, test, and evaluation, defensewide. Electrokinetic transport in liquid foams sciencedirect. Linear electrokinetic phenomena notes vi electrokinetics. Electrokinetics lecture 30 linear electrokinetic phenomena mit student 1 linear electrokinetic. Overview of contents general notions of electrokinetics elementary theories discussion of individual phenomena. The resulting potential is called the electrokinetic or the streaming potential.
Within a single channel, ac electrokinetics can accomplish many essential onchip operations such as active micromixing. Electrokinetic phenomena article about electrokinetic. They are manifestations of the electrical properties of interfaces under steadystate and isothermal conditions. The applications of electrokinetics in the development of microfluidic devices have been widely attractive in the past decade. In the colloidal chemistry literature, it is usually denoted using the greek letter zeta. Electrokinetic phenomena are observed on the interface of two interacting phases, such as a solid, which is in. Electrokinetic phenomena scale favorably with miniaturiza tion and. We give a general, physical description of inducedcharge electroosmosis iceo, the nonlinear electrokinetic slip at a polarizable surface, in the context of some new techniques for microfluidic pumping and mixing. An essential requirement for the observation of electrokinetic phenomena is the formation of an electrochemical double layer at the interface. In typical simulations, interfaces merge and threads break when their size falls below the resolution of the simulation or a. When a fluid flows through a porous medium, charges in the electric double layer are transported, resulting in a streaming current.
Electrokinetic potential an overview sciencedirect topics. Other readers will always be interested in your opinion of the books youve read. In other words, in a saturated porous medium, an electrical potential difference appears when you flow an aqueous fluid through the rock. Electrokinetic phenomena are the movements of fluids and particles driven by. Electrophoresis is the most suitable electrokinetic method to study particulate solids.
It is shown that the code is able to accurately and efficiently recover kinetic phenomena with high degree of fidelity. The movement of drops in electric fields plays a role in processes as diverse as storm cloud formation, inkjet printing and labonachip manipulations. Nonlinear electrokinetic phenomena are electrically driven fluid flows or particle motions, which depend nonlinearly on the applied voltage. Nov 16, 2016 electrokinetic potential is a potential difference at the boundary between the compact layer and the diffuse layer near a solidliquid interface where liquid velocity is zero. The theory of electrokinetic phenomena was developed in close relation with the theories of edl and electrostatic surface forces 1, 345. The approach formulates the coupling as a control problem where the states are the solutions of the nonlocal and local equations, the objective is to minimize their mismatch on the overlap of the non.
These resualts may be considered as a generalization of the smoluchowski equation. A large number of simulations were conducted for singledrop, dropinterface, and dropdrop systems, encompassing a wide range of physical, material, and electrical parameters. Two di erent phenomena contribute to the transport ux of species in a solvent. Electrokinetic phenomena also o er other unique advantages for \labonachip systems, such as low.
Moyer prom the department of botany, university of minnesota, minneapolis received for publication, november 22, 1939 the protein composing the stabilizing film on the fat droplets. Particles can be solid, liquid or gas bubbles with sizes on the scale of a micrometer or nanometer. The inducedcharge electrokinetic motion of a conductive deformable flap which is installed on the walls of a microchannel is numerically studied in this article. The conference is held biannual inside and outside europe. Electrokineticphenomena frank simon leibnizinstitut fur.
Any improvement of the effectiveness of the ed process based on a reduction of the. Practical rules are recommended for performing electrokinetic. Electrokinetic phenomena are a family of several different effects that occur in heterogeneous fluids, or in porous bodies filled with fluid, or in a fast flow over a flat surface. Development of a model for electrokinetic study 266 enhanced by fe 0 wall, for that he has taken model setup as with perspex glass cylindrical cells consisting of three compartments. The term is also used more specifically to refer to inducedcharge electroosmotic flow, driven by an electric field acting on diffuse charge induced near a polarizable surface. Electrokinetic phenomena are a family of effects in which a liquid moves tangentially to a charged surface. The molecular nature of electrokinetic phenomena is examined using molecular dynamics simulations. Various labonchip concepts rely on electrokinetic phenomena to realize unit operations, such as liquid pumping 17, 18, analyzing of ions 19, or the manipulation of particles or cells 20, 21.
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