Streaming Current and Streaming Potential Induced by Water Flow Through Porous Media
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Lab on a Chip PAPER
View Online / Journal Homepage / Table of Contents for this issue Lab on a Chip Dynamic Article LinksC< Cite this: Lab Chip, 2011, 11, 4006 www.rsc.org/loc PAPER Strong enhancement of streaming current power by application of two phase flow Yanbo Xie,a John D. Sherwood,b Lingling Shui,a Albert van den Berga and Jan C. T. Eijkela Received 17th May 2011, Accepted 30th September 2011 DOI: 10.1039/c1lc20423h We show that the performance of a streaming-potential based microfluidic energy conversion system can be strongly enhanced by the use of two phase flow. Injection of gas bubbles into a liquid-filled channel increases both the maximum output power and the energy conversion efficiency. In single- phase systems the internal conduction current induced by the streaming potential limits the output power, whereas in a two-phase system the bubbles reduce this current and increase the power. In our system the addition of bubbles enhanced the maximum output power of the system by a factor of 74 and the efficiency of the system by a factor of 163 compared with single phase flow. Introduction overlap, and efficiency has reached about 3 to 5% in single nano- channels5 and nanopores6 respectively. Recently, Duffin and Say- Energy has become an important topic in scientific research. In kally7,8 used microjets to enhance the energy conversion efficiency particular, novel environmentally-friendly energy conversion to above 10%. systems are required. The developing ‘‘lab on a chip’’ technology Streaming currents or potentials generated by multiphase flow provides new opportunities to convert fluidic mechanical energy 1 have been studied for geophysical, mineral and petroleum to electrical energy. -
Polyelectrolyte Assisted Charge Titration Spectrometry: Applications to Latex and Oxide Nanoparticles
Polyelectrolyte assisted charge titration spectrometry: applications to latex and oxide nanoparticles F. Mousseau1*, L. Vitorazi1, L. Herrmann1, S. Mornet2 and J.-F. Berret1* 1Matière et Systèmes Complexes, UMR 7057 CNRS Université Denis Diderot Paris-VII, Bâtiment Condorcet, 10 rue Alice Domon et Léonie Duquet, 75205 Paris, France. 2Institut de Chimie de la Matière Condensée de Bordeaux, UPR CNRS 9048, Université Bordeaux 1, 87 Avenue du Docteur A. Schweitzer, Pessac cedex F-33608, France. Abstract: The electrostatic charge density of particles is of paramount importance for the control of the dispersion stability. Conventional methods use potentiometric, conductometric or turbidity titration but require large amount of samples. Here we report a simple and cost-effective method called polyelectrolyte assisted charge titration spectrometry or PACTS. The technique takes advantage of the propensity of oppositely charged polymers and particles to assemble upon mixing, leading to aggregation or phase separation. The mixed dispersions exhibit a maximum in light scattering as a function of the volumetric ratio �, and the peak position �!"# is linked to the particle charge density according to � ~ �!�!"# where �! is the particle diameter. The PACTS is successfully applied to organic latex, aluminum and silicon oxide particles of positive or negative charge using poly(diallyldimethylammonium chloride) and poly(sodium 4-styrenesulfonate). The protocol is also optimized with respect to important parameters such as pH and concentration, and to the polyelectrolyte molecular weight. The advantages of the PACTS technique are that it requires minute amounts of sample and that it is suitable to a broad variety of charged nano-objects. Keywords: charge density – nanoparticles - light scattering – polyelectrolyte complex Corresponding authors: [email protected] [email protected] To appear in Journal of Colloid and Interface Science leading to their condensation and to the formation of the electrical double layer [1]. -
Influence of Polyelectrolyte Multilayer Properties on Bacterial Adhesion
polymers Article Influence of Polyelectrolyte Multilayer Properties on Bacterial Adhesion Capacity Davor Kovaˇcevi´c 1, Rok Pratnekar 2, Karmen GodiˇcTorkar 2, Jasmina Salopek 1, Goran Draži´c 3,4,5, Anže Abram 3,4,5 and Klemen Bohinc 2,* 1 Department of Chemistry, Faculty of Science, University of Zagreb, Zagreb 10000, Croatia; [email protected] (D.K.); [email protected] (J.S.) 2 Faculty of Health Sciences, Ljubljana 1000, Slovenia; [email protected] (R.P.); [email protected] (K.G.T.) 3 Jožef Stefan Institute, Ljubljana 1000, Slovenia; [email protected] (G.D.); [email protected] (A.A.) 4 National Institute of Chemistry, Ljubljana 1000, Slovenia 5 Jožef Stefan International Postgraduate School, Ljubljana 1000, Slovenia * Correspondence: [email protected]; Tel.: +386-1300-1170 Academic Editor: Christine Wandrey Received: 16 August 2016; Accepted: 14 September 2016; Published: 26 September 2016 Abstract: Bacterial adhesion can be controlled by different material surface properties, such as surface charge, on which we concentrate in our study. We use a silica surface on which poly(allylamine hydrochloride)/sodium poly(4-styrenesulfonate) (PAH/PSS) polyelectrolyte multilayers were formed. The corresponding surface roughness and hydrophobicity were determined by atomic force microscopy and tensiometry. The surface charge was examined by the zeta potential measurements of silica particles covered with polyelectrolyte multilayers, whereby ionic strength and polyelectrolyte concentrations significantly influenced the build-up process. For adhesion experiments, we used the bacterium Pseudomonas aeruginosa. The extent of adhered bacteria on the surface was determined by scanning electron microscopy. The results showed that the extent of adhered bacteria mostly depends on the type of terminating polyelectrolyte layer, since relatively low differences in surface roughness and hydrophobicity were obtained. -
Surface Polarization Effects in Confined Polyelectrolyte Solutions
Surface polarization effects in confined polyelectrolyte solutions Debarshee Bagchia , Trung Dac Nguyenb , and Monica Olvera de la Cruza,b,c,1 aDepartment of Materials Science and Engineering, Northwestern University, Evanston, IL 60208; bDepartment of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208; and cDepartment of Physics and Astronomy, Northwestern University, Evanston, IL 60208 Contributed by Monica Olvera de la Cruz, June 24, 2020 (sent for review April 21, 2020; reviewed by Rene Messina and Jian Qin) Understanding nanoscale interactions at the interface between ary conditions (18, 19). However, for many biological settings two media with different dielectric constants is crucial for con- as well as in supercapacitor applications, molecular electrolytes trolling many environmental and biological processes, and for confined by dielectric materials, such as graphene, are of interest. improving the efficiency of energy storage devices. In this Recent studies on dielectric confinement of polyelectrolyte by a contributed paper, we show that polarization effects due to spherical cavity showed that dielectric mismatch leads to unex- such dielectric mismatch remarkably influence the double-layer pected symmetry-breaking conformations, as the surface charge structure of a polyelectrolyte solution confined between two density increases (20). The focus of the present study is the col- charged surfaces. Surprisingly, the electrostatic potential across lective effects of spatial confinement by two parallel surfaces -
Electrokinetic Soil Processing in Waste Remediation and Treatment: Synthesis of Available Data
TRANSPORTATION RESEARCH RECORD 1312 153 Electrokinetic Soil Processing in Waste Remediation and Treatment: Synthesis of Available Data YALCIN B. AcAR AND JIHAD HAMED Electrokinetic soil processing is an innovative in situ technique cantly affect the flow, the flow efficiency, and the extent of to remove contaminants from soils and groundwater. The process ion migration and removal in electrokinetic soil processing. is an alternative to conventional processes, with significant eco nomic and technical advantages. This paper provides a compre hensive review of the literature on electrokinetic soil processing. ELECTROKINETIC PHENOMENA IN SOILS The fundamentals of electrokinetic phenomena in soils and their potential use in waste management are presented. A synthesis of Coupling between electrical, chemical, and hydraulic gra available data on the technique is presented. Engineering impli dients is responsible for different types of electrokinetic phe cations regarding the current-voltage regime, duration energy nomena in soils. These phenomena include electroosmosis, requirements, and soil contaminant characteristics are provided. This review indicates that the process can be used efficiently to electrophoresis, streaming potential, and sedimentation po remove ions from saturated soil deposits. tential, as shown in Figure 1. Electroosmosis and electropho resis are the movement of water and particles, respectively, caused by application of a small direct current. Streaming The need to remove contaminants from soil and groundwater, potential and sedimentation potential are the generation of a the high cost of current remediation techniques ($50 to $1,500 current by the movement of water under hydraulic potential per cubic yard of soil), and limited resources lead to an ev and movement of particles under gravitational forces, re erlasting strife to find new, innovative, and cost-effective in spectively. -
Semester II, 2015-16 Department of Physics, IIT Kanpur PHY103A: Lecture # 5 Anand Kumar
Semester II, 2017-18 Department of Physics, IIT Kanpur PHY103A: Lecture # 8 (Text Book: Intro to Electrodynamics by Griffiths, 3rd Ed.) Anand Kumar Jha 19-Jan-2018 Summary of Lecture # 7: • Electrostatic Boundary Conditions E E = Electric Field: = above below E − E = 00 above− below � 0 above − below Electric Potential: V V = 0 above − below • Basic Properties of Conductors (1) The electric field = 0 inside a conductor, always. = 0 = = 0 (2) The charge density inside a conductor. This is because . (3) Any net charge resides on the surface. Why? To minimize the energy. 0 ⋅ (4) A conductor is an equipotential. (5) is perpendicular to the surface, just outside the conductor. 2 Summary of Lecture # 7: Prob. 2.36 (Griffiths, 3rd Ed. ): - Surface charge ? = = − 2 - Surface charge ? 4 + - Surface charge ? = − 2 4 1 2 - ( ) ? = 4 out 2 1 0 � - ( ) ? = 4 out 2 10 �+ - ( ) ? =4 out out 2 � - Force on ? 0 40 - Force on ? 0 3 Summary of Lecture # 7: Prob. 2.36 (Griffiths, 3rd Ed. ): - Surface charge ? = Same ª = − 2 Same - Surface charge ? 4 ª + - Surface charge ? = − 2 Changes � 4 1 2 = - ( ) ? 4 Same ª out 2 1 0 � = 4 - ( ) ? Same ª out 2 � 10 + Changes � - ( ) ? =4 out out 2 - Force on ? 0 0 � 4 Same ª Bring in a third - Force on ? 0 Same ª charge 4 Surface Charge and the Force on a Conductor: What is the electrostatic force on the patch? Force per unit area on the patch is: = (? ) = other = + , above other patch above = + 2 other 0 � = + , below other patch below 1 = = + 2 2 other − � other above below 0 But, inside a metal, = , so = 0 below = = + = 2 2 other � above other � � 5 0 0 0 Surface Charge and the Force on a Conductor: What is the electrostatic force on the patch? Force per unit area on the patch is: = (? ) = other = = 2 other � above � Force per unit0 area on the patch is: 0 = = 2 2 other � Force per unit area is pressure.0 So, the electrostatic pressure is: = = 2 2 20 2 6 0 Capacitor: Two conductors with charge and . -
Ion Current Rectification in Extra-Long Nanofunnels
applied sciences Article Ion Current Rectification in Extra-Long Nanofunnels Diego Repetto, Elena Angeli * , Denise Pezzuoli, Patrizia Guida, Giuseppe Firpo and Luca Repetto Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genoa, Italy; [email protected] (D.R.); [email protected] (D.P.); [email protected] (P.G.); giuseppe.fi[email protected] (G.F.); [email protected] (L.R.) * Correspondence: [email protected] Received: 29 April 2020; Accepted: 25 May 2020; Published: 28 May 2020 Abstract: Nanofluidic systems offer new functionalities for the development of high sensitivity biosensors, but many of the interesting electrokinetic phenomena taking place inside or in the proximity of nanostructures are still not fully characterized. Here, to better understand the accumulation phenomena observed in fluidic systems with asymmetric nanostructures, we study the distribution of the ion concentration inside a long (more than 90 µm) micrometric funnel terminating with a nanochannel. We show numerical simulations, based on the finite element method, and analyze how the ion distribution changes depending on the average concentration of the working solutions. We also report on the effect of surface charge on the ion distribution inside a long funnel and analyze how the phenomena of ion current rectification depend on the applied voltage and on the working solution concentration. Our results can be used in the design and implementation of high-performance concentrators, which, if combined with high sensitivity detectors, could drive the development of a new class of miniaturized biosensors characterized by an improved sensitivity. Keywords: nanofunnel; FEM simulation; ionic current rectification; micro-nano structure interface 1. -
Beryllium Desorption from Minerals and Organic Ligands Over Time
Chemical Geology 439 (2016) 52–58 Contents lists available at ScienceDirect Chemical Geology journal homepage: www.elsevier.com/locate/chemgeo Beryllium desorption from minerals and organic ligands over time Vanessa Boschi ⁎,JaneK.Willenbring Department of Earth and Environmental Science, University of Pennsylvania, 251 Hayden Hall, 240 South 33rd Street, Philadelphia, PA 19104, USA article info abstract Article history: Beryllium isotopes sorbed to sediments have provided useful tools in the field of geochronology and geomor- Received 13 April 2016 phology over the last few decades. The use of beryllium isotopes relies on the premise that beryllium sorbed to Received in revised form 3 June 2016 sediments is unaltered over large timescales. Changes in the environmental chemistry, either in-situ or en Accepted 10 June 2016 route from soil to fluvial system, to the ocean, can cause beryllium desorption and may preclude some beryllium Available online 11 June 2016 isotopic applications. Keywords: Four mechanisms were tested to determine the relative desorption potential of beryllium including a reduction Beryllium in pH, an increase in ionic strength (NaCl) and complexation by soluble organic (malonic acid) and inorganic spe- Desorption cies (NaF). To assess the relative effect of each mechanism on beryllium desorption from both organic and min- Minerals eral fractions, we prepared separate solutions of beryllium bound to minerals and organic compounds and Organic ligands measured beryllium concentrations in solution before and after each chemical perturbation. We conclude a re- Inner and outer sphere complexation duction in pH resulted in the greatest amount of desorption among the four treatments, removing 97% and 75% of sorbed beryllium from illite and montmorillonite, respectively, and none from the organic ligands tested. -
6.007 Lecture 5: Electrostatics (Gauss's Law and Boundary
Electrostatics (Free Space With Charges & Conductors) Reading - Shen and Kong – Ch. 9 Outline Maxwell’s Equations (In Free Space) Gauss’ Law & Faraday’s Law Applications of Gauss’ Law Electrostatic Boundary Conditions Electrostatic Energy Storage 1 Maxwell’s Equations (in Free Space with Electric Charges present) DIFFERENTIAL FORM INTEGRAL FORM E-Gauss: Faraday: H-Gauss: Ampere: Static arise when , and Maxwell’s Equations split into decoupled electrostatic and magnetostatic eqns. Electro-quasistatic and magneto-quasitatic systems arise when one (but not both) time derivative becomes important. Note that the Differential and Integral forms of Maxwell’s Equations are related through ’ ’ Stoke s Theorem and2 Gauss Theorem Charges and Currents Charge conservation and KCL for ideal nodes There can be a nonzero charge density in the absence of a current density . There can be a nonzero current density in the absence of a charge density . 3 Gauss’ Law Flux of through closed surface S = net charge inside V 4 Point Charge Example Apply Gauss’ Law in integral form making use of symmetry to find • Assume that the image charge is uniformly distributed at . Why is this important ? • Symmetry 5 Gauss’ Law Tells Us … … the electric charge can reside only on the surface of the conductor. [If charge was present inside a conductor, we can draw a Gaussian surface around that charge and the electric field in vicinity of that charge would be non-zero ! A non-zero field implies current flow through the conductor, which will transport the charge to the surface.] … there is no charge at all on the inner surface of a hollow conductor. -
Streaming Potential Analysis
ABSTRACT WANG, YUN. Colloidal Behavior of Polyampholytes. (Under the direction of Dr. M. A. Hubbe). Polyampholytes are polymers that have both positively and negatively charged groups in the same chain. In recent years polyampholytes have started to be used in papermaking applications, as well as in sludge treatment processes. Benefits, in the case of papermaking, have included increased dry-strength and faster removal of water. But the molecular mechanisms by which such benefits are achieved have not been fully understood. This thesis project focused on effects related to polyampholyte charge density. A series of polyampholytes with a fixed charge ratio but different charge density was used for the experiments. Analysis methods included pH titrations, streaming current titrations, and adsorption isotherms. From pH titrations the charge density of cationic and anionic groups under different pH were calculated. From streaming current tests the net apparent charge density under different pH was calculated. And from adsorption tests it was found that the highest adsorbed amounts were achieved in certain cases corresponding to the highest content of ionic groups on the polyampholytes. Adsorption depended strongly on pH. Substantial differences were observed when comparing results obtained with polyampholyte samples versus ordinary polyelectrolyte samples with same charge density of cationic or anionic groups. Colloidal Behavior of Polyampholytes by YUN WANG A thesis submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirements for the Degree of Master of Science PULP AND PAPER SCIENCE Raleigh 2006 APPROVED BY: ________________________ _________________________ _________________________ Chair of Advisory Committee BIOGRAPHY The author was born on November 10, 1981 in Changzhou, Jiangsu province, People’s Republic of China. -
On the Effect of Hydrodynamic Slip on the Polarization of a Nonconducting Spherical Particle in an Alternating Electric Field
Mechanical Engineering Faculty Publications Mechanical Engineering 2010 On the Effect of Hydrodynamic Slip on the Polarization of a Nonconducting Spherical Particle in an Alternating Electric Field Hui Zhao University of Nevada, Las Vegas, [email protected] Follow this and additional works at: https://digitalscholarship.unlv.edu/me_fac_articles Part of the Electrical and Computer Engineering Commons, Mechanical Engineering Commons, and the Nanoscience and Nanotechnology Commons Repository Citation Zhao, H. (2010). On the Effect of Hydrodynamic Slip on the Polarization of a Nonconducting Spherical Particle in an Alternating Electric Field. Physics of Fluids, 22(7), 1-15. https://digitalscholarship.unlv.edu/me_fac_articles/557 This Article is protected by copyright and/or related rights. It has been brought to you by Digital Scholarship@UNLV with permission from the rights-holder(s). You are free to use this Article in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This Article has been accepted for inclusion in Mechanical Engineering Faculty Publications by an authorized administrator of Digital Scholarship@UNLV. For more information, please contact [email protected]. On the effect of hydrodynamic slip on the polarization of a nonconducting spherical particle in an alternating electric field Hui Zhao Citation: Phys. Fluids 22, 072004 (2010); doi: 10.1063/1.3464159 View online: http://dx.doi.org/10.1063/1.3464159 View Table of Contents: http://pof.aip.org/resource/1/PHFLE6/v22/i7 Published by the AIP Publishing LLC. -
Analysis of Streaming Potential Flow and Electroviscous Effect in a Shear
www.nature.com/scientificreports OPEN Analysis of streaming potential fow and electroviscous efect in a shear‑driven charged slit microchannel Adham Riad, Behnam Khorshidi & Mohtada Sadrzadeh* Investigating the fow behavior in microfuidic systems has become of interest due to the need for precise control of the mass and momentum transport in microfuidic devices. In multilayered‑fows, precise control of the fow behavior requires a more thorough understanding as it depends on multiple parameters. The following paper proposes a microfuidic system consisting of an aqueous solution between a moving plate and a stationary wall, where the moving plate mimics a charged oil–water interface. Analytical expressions are derived by solving the nonlinear Poisson–Boltzmann equation along with the simplifed Navier–Stokes equation to describe the electrokinetic efects on the shear‑ driven fow of the aqueous electrolyte solution. The Debye–Huckel approximation is not employed in the derivation extending its compatibility to high interfacial zeta potential. Additionally, a numerical model is developed to predict the streaming potential fow created due to the shear‑driven motion of the charged upper wall along with its associated electric double layer efect. The model utilizes the extended Nernst–Planck equations instead of the linearized Poisson–Boltzmann equation to accurately predict the axial variation in ion concentration along the microchannel. Results show that the interfacial zeta potential of the moving interface greatly impacts the velocity profle of the fow and can reverse its overall direction. The numerical results are validated by the analytical expressions, where both models predicted that fow could reverse its overall direction when the interfacial zeta potential of the oil–water is above a certain threshold value.