Streaming current

Abstract: PREFACE COPYRIGHT ACKNOWLEDGMENTS CHAPTER 1 MATHEMATICAL PRELIMINARIES 11 Units 12 Physical Constants and Conversion Factors 13 Frequently used Functions 14 Vector Operations 15 Tensor Operations 16 Vector and Tensor Integral Theorems 17 References CHAPTER 2 COLLOIDAL SYSTEMS 21 The Colloidal State 22 Colloidal Phenomena 23 Stabilization of Colloids 24 Preparation of Colloidal Systems 25 Purification of Sols 26 A Historical Summary 27 Electrokinetic Phenomena in Modern Colloid Science 28 Nomenclature 29 References CHAPTER 3 ELECTROSTATICS 31 Basic Electrostatics in Free Space 32 Summary of Electrostatic Equations in Free Space 33 Electrostatic Classification of Materials 34 Basic Electrostatics in Dielectrics 35 Boundary Conditions for Electrostatic Equations 36 Maxwell Stress for a Linear Dielectric 37 Maxwell's Equations of Electromagnetism 38 Nomenclature 39 References CHAPTER 4 APPLICATION OF ELECTROSTATICS 41 Two-Dimensional Dielectric Slab in an External Electric Field 42 A Dielectric Sphere in an External Electric Field 43 A Conducting Sphere in an External Electric Field 44 Charged Disc and Two Parallel Discs in a Dielectric Medium 45 Point Charges in a Dielectric Medium 46 Nomenclature 47 Problems 48 References CHAPTER 5 ELECTRIC DOUBLE LAYER 51 Electric Double Layers at Charged Interfaces 52 Potential for Planar Electric Double Layer 53 Potential for Curved Electric Double Layer 54 Electrostatic Interaction between Two Planar Surfaces 55 Electrostatic Potential Energy 56 Electrostatic Interactions between Curved Geometries 561 The Derjaguin Approximation 57 Models of Surface Potentials 58 Zeta Potential 59 Summary of Gouy-Chapman Model 510 Nomenclature 511 Problems 512 References CHAPTER 6 FUNDAMENTAL TRANSPORT EQUATIONS 61 Single-Component System 62 Multicomponent Systems 63 Hydrodynamics of Colloidal Systems 64 Summary of Governing Equations 65 Nomenclature 66 Problems 67 References CHAPTER 7 ELECTROKINETIC PHENOMENA 71 Electroosmosis 72 Streaming Potential 73 Electrophoresis 74 Sedimentation Potential 75 Non-Equilibrium Processes and Onsager Relationships 76 Nomenclature 77 References CHAPTER 8 FLOW IN MICROCHANNELS 81 Liquid Flow in Channels 82 Electroosmotic Flow in a Slit Charged Microchannel 83 Electroosmotic Flow in a Closed Slit Microchannel 84 Effectiveness of Electroosmotic Flow 85 Electric Current in Electroosmotic Flow in Slit Channels 86 Streaming Potential in Slit Channels 87 Electroviscous Flow in Slit Microchannels 88 Electroosmotic flow in a Circular Charged Capillary 89 High Surface Potential 810 Surface Conductance 811 Solute Dispersion in Microchannels 812 Nomenclature 813 Problems 814 References CHAPTER 9 ELECTROPHORESIS 91 Introduction 92 Electrophoresis of a Single Charged Sphere 93 Improved Solutions: Arbitrary Debye Length 94 Electrophoretic Mobility in Concentrated Suspensions 95 Circular Cylinders Normal to the Electric Field 96 Nomenclature 97 Problems 98 References CHAPTER 10 SEDIMENTATION POTENTIAL 101 Sedimentation of Uncharged Spherical Particles 102 Concept of Sedimentation Potential and Velocity 103 Dilute Suspensions: Ohshima's Model 104 Sedimentation Potential of Concentrated Suspensions 105 Nomenclature 106 Problems 107 References CHAPTER 11 LONDON-VAN DERWAALS FORCES ANDTHE DLVOTHEORY 111 Dispersion Forces Between Bodies in Vacuum 112 Hamaker's Approach 113 Effects of Intervening Medium 114 DLVO Theory of Colloidal Interactions 115 Schulze-Hardy Rule 116 Verification of the DLVO Theory 117 Limitations of DLVO Theory 118 Nomenclature 119 Problems 1110 References CHAPTER 12 COAGULATION OF PARTICLES 121 Introduction 122 Dynamics of Coagulation 123 Brownian Motion 124 Collision Frequency 125 Brownian Coagulation 126 Coagulation due to Shear 127 Nomenclature 128 Problems 129 References CHAPTER 13 DEPOSITION OF COLLOIDAL PARTICLES 131 Introduction 132 Classical Deposition Mechanisms 133 Eulerian Approach 134 Lagrangian Approach 135 Deposition Efficiency and Sherwood Number 136 Experimental Verifications 137 Application of Deposition Theory 138 Summary of Dimensionless Groups 139 Nomenclature 1310 Problems 1311 References CHAPTER 14 NUMERICAL SIMULATION OF ELECTROKINETIC PHENOMENA 141 Tools and Methods for Computer Based Simulations 142 Numerical Solution of the Poisson-Boltzmann Equation 26 Validation of Numerical Results 143 Flow of Electrolyte in a Charged Cylindrical Capillary in a Capillary Microchannel 144 Analysis of Electrophoretic Mobility 145 Concluding Remarks 146 Nomenclature 147 Problems 148 References CHAPTER 15 ELECTROKINETIC APPLICATIONS 151 Introduction 152 Electrokinetic Salt Rejection in Porous Media and Membranes 153 Electroosmotic Control of HazardousWastes 154 Iontophoretic Delivery of Drugs 155 Flotation of Oil Droplets and Fine Particles 156 Rheology of Colloidal Suspensions 157 Bitumen Extraction From Oil Sands 158 Microfluidic and Nanofluidic Applications 159 Nomenclature 1510 References INDEX

Abstract: The performance (i.e., water flux and solute rejection) of a thin-film composite aromatic polyamide nanofiltration membrane and its relation to membrane surface charge (electrokinetic) characteristics were investigated. Membrane performance and streaming potential measurements were carried out as a function of pH for several solution chemistries, including an indifferent electrolyte, humic acid, and anionic and cationic surfactants. Performance results for the membrane were interpreted by relating the water flux and salt/ion rejection to the membrane charge characteristics. In the case of the indifferent electrolyte (NaCl), water flux and salt passage were maximal at the membrane pore isoelectric point (pH 5) primarily due to decreased electrostatic repulsion and increased pore volume (size) in the cross-linked polymer network. Ion rejection is directly related to the membrane pore charge and is attributed to co-ion electrostatic repulsion (exclusion). At low pH, negative rejection of protons was observed...

Abstract: The buildup of the first layers of a polystyrenesulfonate (PSS)/polyallylamine (PAH) multilayer is studied in situ by means of streaming potential measurements (SPM) and by scanning angle reflectom...