644 Pages 100 B/W Illustrations
    by CRC Press

    A proper understanding of diffusion and mass transfer theory is critical for obtaining correct solutions to many transport problems. Diffusion and Mass Transfer presents a comprehensive summary of the theoretical aspects of diffusion and mass transfer and applies that theory to obtain detailed solutions for a large number of important problems. Particular attention is paid to various aspects of polymer behavior, including polymer diffusion, sorption in polymers, and volumetric behavior of polymer–solvent systems.

    The book first covers the five elements necessary to formulate and solve mass transfer problems, that is, conservation laws and field equations, boundary conditions, constitutive equations, parameters in constitutive equations, and mathematical methods that can be used to solve the partial differential equations commonly encountered in mass transfer problems. Jump balances, Green’s function solution methods, and the free-volume theory for the prediction of self-diffusion coefficients for polymer–solvent systems are among the topics covered. The authors then use those elements to analyze a wide variety of mass transfer problems, including bubble dissolution, polymer sorption and desorption, dispersion, impurity migration in plastic containers, and utilization of polymers in drug delivery. The text offers detailed solutions, along with some theoretical aspects, for numerous processes including viscoelastic diffusion, moving boundary problems, diffusion and reaction, membrane transport, wave behavior, sedimentation, drying of polymer films, and chromatography.

    Presenting diffusion and mass transfer from both engineering and fundamental science perspectives, this book can be used as a text for a graduate-level course as well as a reference text for research in diffusion and mass transfer. The book includes mass transfer effects in polymers, which are very important in many industrial processes. The attention given to the proper setup of numerous problems along with the explanations and use of mathematical solution methods will help readers in properly analyzing mass transfer problems.

    Introduction
    Generalized Transport Phenomena Approach to Problem Analysis
    General Content

    Conservation Laws and Field Equations
    Concentrations, Velocities, and Fluxes
    Thermodynamics of Purely Viscous Fluid Mixtures
    Conservation of Mass for a One-Component System
    Conservation of Mass for a Mixture
    Modification of Field Equations for Mass Transfer
    Conservation of Linear Momentum for One-Component Systems
    Conservation of Linear Momentum for a Mixture
    Conservation of Moment of Momentum for One-Component Systems
    Conservation of Moment of Momentum for a Mixture
    Strategies for the Solution of Mass Transfer Problems

    Boundary Conditions
    Definitions
    Jump Balances for Mass Conservation
    Jump Balances for Linear Momentum Conservation
    Postulated Boundary Conditions at Phase Interfaces
    Boundary Conditions in the Absence of Mass Transfer
    Utilization of Jump Balances
    Additional Comments on Boundary Conditions
    Boundary Conditions and Uniqueness of Solutions

    Constitutive Equations
    Constitutive Principles
    First-Order Theory for Binary Systems
    Combined Field and Constitutive Equations for First-Order Binary Theory
    First-Order Theory for Ternary Systems
    Special Second-Order Theory for Binary Systems
    Viscoelastic Effects in Flow and Diffusion
    Validity of Constitutive Equations

    Parameters in Constitutive Equations
    General Approach in Parameter Determination
    Diffusion in Polymer–Solvent Mixtures
    Diffusion in Infinitely Dilute Polymer Solutions
    Diffusion in Dilute Polymer Solutions
    Diffusion in Concentrated Polymer Solutions – Free-Volume Theory for Self-Diffusion
    Diffusion in Concentrated Polymer Solutions – Mutual Diffusion Process
    Diffusion in Crosslinked Polymers
    Additional Properties of Diffusion Coefficients

    Special Behaviors of Polymer–Penetrant Systems
    Volumetric Behavior of Polymer–Penetrant Systems
    Sorption Behavior of Polymer–Penetrant Systems
    Antiplasticization
    Nonequilibrium at Polymer–Penetrant Interfaces

    Mathematical Apparatus
    Basic Definitions
    Classification of Second-Order Partial Differential Equations
    Specification of Boundary Conditions
    Sturm–Liouville Theory
    Series and Integral Representations of Functions
    Solution Methods for Partial Differential Equations
    Separation of Variables Method
    Separation of Variables Solutions
    Integral Transforms
    Similarity Transformations
    Green’s Functions for Ordinary Differential Equations
    Green’s Functions for Elliptic Equations
    Green’s Functions for Parabolic Equations
    Perturbation Solutions
    Weighted Residual Method

    Solution Strategy for Mass Transfer Problems
    Proposed Solution Methods
    Induced Convection

    Solutions of a General Set of Mass Transfer Problems
    Mixing of Two Ideal Gases
    Steady Evaporation of a Liquid in a Tube
    Unsteady-State Evaporation
    Analysis of Free Diffusion Experiments
    Dissolution of a Rubbery Polymer
    Bubble Growth from Zero Initial Size
    Stability Behavior and Negative Concentrations in Ternary Systems
    Analysis of Impurity Migration in Plastic Containers
    Efficiency of Green’s Function Solution Method
    Mass Transfer in Tube Flow
    Time-Dependent Interfacial Resistance
    Laminar Liquid Jet Diffusion Analysis
    Analysis of the Diaphragm Cell
    Dissolved Organic Carbon Removal from Marine Aquariums
    Unsteady Diffusion in a Block Copolymer
    Drying of Solvent-Coated Polymer Films
    Flow and Diffusion Past a Flat Plate with Solid Dissolution
    Gas Absorption in Vertical Laminar Liquid Jet
    Utilization of Polymers in Drug Delivery
    Gas Absorption and Diffusion into a Falling Liquid Film

    Perturbation Solutions of Mass Transfer Moving Boundary Problems
    Dissolution of a Plane Surface of a Pure Gas Phase
    Bubble Dissolution
    Singular Perturbations in Moving Boundary Problems
    Dropping Mercury Electrode
    Sorption in Thin Films
    Numerical Analysis of Mass Transfer Moving Boundary Problems

    Diffusion and Reaction
    Design of a Tubular Polymerization Reactor
    Transport Effects in Low-Pressure CVD Reactors
    Solution of Reaction Problems with First-Order Reactions
    Plug Flow Reactors with Variable Mass Density
    Bubble Dissolution and Chemical Reaction
    Danckwerts Boundary Conditions for Chemical Reactors

    Transport in Nonporous Membranes
    Assumptions Used in the Theory for Membrane Transport
    Steady Mass Transport in Binary Membranes
    Steady Mass Transport in Ternary Membranes
    Unsteady Mass Transport in Binary Membranes
    Phase Inversion Process for Forming Asymmetric Membranes
    Pressure Effects in Membranes

    Analysis of Sorption and Desorption
    Derivation of a Short-Time Solution Form for Sorption in Thin Films
    Sorption to a Film from a Pure Fluid of Finite Volume
    A General Analysis of Sorption in Thin Films
    Analysis of Step-Change Sorption Experiments
    Integral Sorption in Glassy Polymers
    Integral Sorption in Rubbery Polymers
    Oscillatory Diffusion and Diffusion Waves

    Dispersion and Chromatography
    Formulation of Taylor Dispersion Problem
    Dispersion in Laminar Tube Flow for Low Peclet Numbers
    Dispersion in Laminar Tube Flow for Long Times
    Dispersion in Laminar Tube Flow for Short Times
    Analysis of an Inverse Gas Chromatography Experiment

    Effects of Pressure Gradients on Diffusion: Wave Behavior and Sedimentation
    Wave Propagation in Binary Fluid Mixtures
    Hyperbolic Waves
    Dispersive Waves
    Time Effects for Parabolic and Hyperbolic Equations
    Sedimentation Equilibrium

    Viscoelastic Diffusion
    Experimental Results for Sorption Experiments
    Viscoelastic Effects in Step-Change Sorption Experiments
    Slow Bubble Dissolution in a Viscoelastic Fluid

    Transport with Moving Reference Frames
    Relationships Between Fixed and Moving Reference Frames
    Field Equations in Moving Reference Frames
    Steady Diffusion in an Ultracentrifuge
    Material Time Derivative Operators
    Frame Indifference of Material Time Derivatives
    Frame Indifference of Velocity Gradient Tensor
    Rheological Implications

    Appendix: Vector and Tensor Notation
    General Notation Conventions
    Vectors
    Tensors
    Results for Curvilinear Coordinates
    Material and Spatial Representations
    Reynolds’ Transport Theorem

    Biography

    James S. Vrentas received his B.S. degree in chemical engineering from the University of Illinois and his M.Ch.E. and Ph.D. degrees in chemical engineering from the University of Delaware. As the Dow Professor of Chemical Engineering at the Pennsylvania State University, he teaches and conducts research in the fundamental aspects of diffusion and fluid mechanics. He is the recipient of two national AIChE awards, the William H. Walker Award for Excellence in Contributions to the Chemical Engineering Literature and the Charles M. A. Stine Award for Materials Engineering and Science. At Penn State, he has received the College of Engineering’s Premier Research Award and several teaching awards.

    Christine M. Vrentas received her B.S. degree in chemical engineering from the Illinois Institute of Technology and her M.S. and Ph.D. degrees in chemical engineering from Northwestern University where she studied the dynamic and transient properties of polymer solutions. She has served as an instructor at the Pennsylvania State University and is currently an adjunct professor in the chemical engineering department working in the areas of diffusion and fluid mechanics. As a public school volunteer and supporter of science education, she helped coach State College Area Middle and High School Science Olympiad teams to national gold medals and served as a regional and state event supervisor at Science Olympiad competitions.

    "Finally a text which integrates in an easily understandable and logical fashion the coupled nature of the equations of change with respect to multicomponent mass transfer and its constitutive equations."
    —William H. Velander, University of Nebraska, Lincoln

    "The book begins with a description of conservation laws, boundary conditions and constitutive equations…presents a mathematical treatment not covered in other similar books. This is a modern approach to transport phenomena. The unique feature of the book is the treatment of several topics, such as sorption, chromatography, and viscoelastic diffusion."
    —Darsh T. Wasan, Dimitri Gidaspow, Illinois Institute of Technology