Book contents
- Frontmatter
- Contents
- Preface
- Nomenclature
- Introduction
- 1 Kinematics, Conservation Equations, and Boundary Conditions for Incompressible Flow
- 2 Unidirectional Flow
- 3 Hydraulic Circuit Analysis
- 4 Passive Scalar Transport: Dispersion, Patterning, and Mixing
- 5 Electrostatics and Electrodynamics
- 6 Electroosmosis
- 7 Potential Fluid Flow
- 8 Stokes Flow
- 9 The Diffuse Structure of the Electrical Double Layer
- 10 Zeta Potential in Microchannels
- 11 Species and Charge Transport
- 12 Microchip Chemical Separations
- 13 Particle Electrophoresis
- 14 DNA Transport and Analysis
- 15 Nanofluidics: Fluid and Current Flow in Molecular-Scale and Thick-EDL Systems
- 16 AC Electrokinetics and the Dynamics of Diffuse Charge
- 17 Particle and Droplet Actuation: Dielectrophoresis, Magnetophoresis, and Digital Microfluidics
- APPENDIX A Units and Fundamental Constants
- APPENDIX B Properties of Electrolyte Solutions
- APPENDIX C Coordinate Systems and Vector Calculus
- APPENDIX D Governing Equation Reference
- APPENDIX E Nondimensionalization and Characteristic Parameters
- APPENDIX F Multipolar Solutions to the Laplace and Stokes Equations
- APPENDIX G Complex Functions
- APPENDIX H Interaction Potentials: Atomistic Modeling of Solvents and Solutes
- Bibliography
- Index
APPENDIX H - Interaction Potentials: Atomistic Modeling of Solvents and Solutes
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- Preface
- Nomenclature
- Introduction
- 1 Kinematics, Conservation Equations, and Boundary Conditions for Incompressible Flow
- 2 Unidirectional Flow
- 3 Hydraulic Circuit Analysis
- 4 Passive Scalar Transport: Dispersion, Patterning, and Mixing
- 5 Electrostatics and Electrodynamics
- 6 Electroosmosis
- 7 Potential Fluid Flow
- 8 Stokes Flow
- 9 The Diffuse Structure of the Electrical Double Layer
- 10 Zeta Potential in Microchannels
- 11 Species and Charge Transport
- 12 Microchip Chemical Separations
- 13 Particle Electrophoresis
- 14 DNA Transport and Analysis
- 15 Nanofluidics: Fluid and Current Flow in Molecular-Scale and Thick-EDL Systems
- 16 AC Electrokinetics and the Dynamics of Diffuse Charge
- 17 Particle and Droplet Actuation: Dielectrophoresis, Magnetophoresis, and Digital Microfluidics
- APPENDIX A Units and Fundamental Constants
- APPENDIX B Properties of Electrolyte Solutions
- APPENDIX C Coordinate Systems and Vector Calculus
- APPENDIX D Governing Equation Reference
- APPENDIX E Nondimensionalization and Characteristic Parameters
- APPENDIX F Multipolar Solutions to the Laplace and Stokes Equations
- APPENDIX G Complex Functions
- APPENDIX H Interaction Potentials: Atomistic Modeling of Solvents and Solutes
- Bibliography
- Index
Summary
Most of this text uses continuum, ideal-solution theory to describe transport in microand nanoscale systems. Molecule-scale interactions, however, require that the interactions of the solvent, dissolved electrolytes, and macromolecules be treated in more detail. The first example of this in the text is the steric modification of the Poisson–Boltzmann description of the EDL presented in Chapter 9. Other examples of this include the intermolecular potentials used in atomistic simulations, excluded-volume modeling for predictions of DNA conformation in nanochannels, and colloidal simulations. This appendix focuses on the general concepts of interaction potentials and distribution functions, with a focus on atomistic modeling. As is often done in the atomistic/molecular dynamics literature, we use the term atom in this appendix in the original sense of an indivisible unit rather than the modern chemical sense of a nucleus surrounded by an electron cloud. Thus the term atom in this appendix refers in general to any entity that we model based on its potential energy – e.g., solvent molecules or dissolved ions or even boundaries.
THERMODYNAMICS OF INTERMOLECULAR POTENTIALS
Atoms that interact rarely are straightforward to model thermodynamically. That these atoms rarely interact is the basic premise of the ideal gas law and the ideal solution approximation. For example, the Boltzmann approximation for ions in an electrolyte consists of treating the ions as if they do not interact with each other, interacting only with a continuum electrical field.
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- Chapter
- Information
- Micro- and Nanoscale Fluid MechanicsTransport in Microfluidic Devices, pp. 475 - 494Publisher: Cambridge University PressPrint publication year: 2010