Natural and synthetic high polymers

BOOK R E V I E W S considerable and t h a t the theories placing emphasis on one selected parameter over another as controlling the course of catalytic reactions have a limited value. However, the present book will stimulate the reader to realize the need for theories having a predictive value no m a t t e r how simple their models may be as compared with the actual systems involved in experimental work. For this reason, this book is recommended not only to those who would like to promote their I knowledge in the field of interactions at interfaces, but also to researchers in other fields who would like to add the intellectual and experimental challenge of basic studies in catalysis to their research repertoire. KAMIL KI~IER

Center for Surface and Coatings Research Lehigh University Bethlehem, Pennsylvania 18015 Theory o f V i s c o e l a s t i c i t y - - A n I n t r o d u c t i o n . By R. iV[. CHRISTENSEN. Academic Press, New York, 1971. 239 pp. $13.50. This book presents an integrated and mathematically sophisticated development of the continuum theory of viscoelasticity with emphasis on the linear theory. While the book contains nothing really new, it does have considerable merit in that it brings together, in a consistent manner, work that has been presented in many diverse sources. The major topics considered in the chapters dealing with the linear theory are: Viscoelastic stress strain constitutive relations; Formulation procedures and solution techniques for isothermal boundary value problems; Thermoviscoelasticity; Wave propagation; and a brief treatment of such general topics as variational and minimum theorems. In addition to the linear theory, one chapter (25 pages) is devoted to an introductory study of a nonlinear theory. Another chapter (29 pages) is concerned with the determination of mechanical properties via relaxation and creep; steady state harmonic oscillation; and wave propagation procedures. Temperature effects and nonlinear mechanical Properties are also discussed briefly. While the book is well written and does attain the goal of presenting a consistent and well integrated theoretical presentation, it cannot be considered as introductory material except for those well versed in tensor mathematics. The author states that this book should be supplemented by a book on the linear theory of elasticity which employs Cartesian tensor notation. We feel t h a t most such introductory texts would not introduce the

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reader to all of the mathematics needed to appreciate Dr. Christensen's book. MARVIN Ctt/kRLES AND GARY POEHLF,IN

Department of Chemical Engineering Lehigh University Bethlehem, Pennsylvania 18015 Mass Transfer in H e t e r o g e n e o u s Catalysis. B y C~)~RLF~S N. SATTERFIELD. ~ . I. T. Press, Cambridge, Mass. 1969. 267 pp. $14.25. This book is essentially an updated version of an earlier one, The Role of Diffusion in Catalysis by Professors Satterfield and Sherwood. The principal emphasis is on the effects of the interactions of intraparticle mass and heat transfer on the effectiveness of porous catalysts, and some attention is also paid to extraparticle effects. Most of the first chapter is devoted to methods of treating diffusion of gases in porous catalysts. Molecular diffusion in gases and liquids is discussed briefly. Models for porous structures are then considered in the context of predicting or correlating diffusive fluxes. 1%ecent developments are reviewed critically, and a reasonable summary of available experimental data is included. The second chapter deals with mass and heat transfer between bulk fluid and the particle fluid interface as encountered in fixed bed, fluid bed, trickle bed, and slurry reactors. The third and fourth chapters treat the theory of simultaneous diffusion and reaction in porous catalysts. 1V[ethods of determining the effectivenss factor are given in some detail. Isothermal and nonisothermal cases are considered for irreversible reactions with simple kinetics, as are isothermal reactions with complex kinetics. The theoretical developments are well illustrated by results from the recent literature. The final chapter briefly dis cusses catalyst poisoning and the effects of diffusion on selectivity and catalyst regeneration. The book is a valuable source of information on transport effects in fluid-solid catalytic reactions. The material is clearly presented with sufficient theory and supporting experimental data from the recent literature to be genuinely useful. GORDON R. YOUNGQUIST

Department of Chemical Engineering Clarkson College of Technology Potsdam, New Yorlc 13676 N a t u r a l and S y n t h e t i c H i g h Polymers. Edited by P. DIEHL, ]~. FLUCK, =~NDi%. KOSFELD, in series NMR Basic P r i n c i p l e s and Progress, Vol. 4, Springer-Verlag, Berlin, 1970. 309 pp., 202 figs. This monograph provides condensed versions of the principal papers given at the 7th Colloquium on Nuclear Magnetic Resonance SpectrosJournal

of Colloidand InterfaceScience,Vol. 38, No. 3, March 1972

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BOOK REVIEWS

copy, which was held in order to honor the 100th anniverary of the Technical University of the Rhineland and Westphalia, Aachen, April 13-17, 1970. The stated purpose of the book is to present review and research articles by NMR specialists which will include both introductory matters and recent developments. This is a formidable task, for, as pointed out by F. A. Bovey, more than 600 significant references in the field have appeared since its birth about a decade ago. There are 17 articles in all, by many of the leading experts in the NMI~ spectroscopy of polymers; a wide range of experimentM and theoretical topics is, indeed, covered. Current developments in the use of high-resolution NMR (especially at 220 MHz) to elucidate the configuration of vinyl polymers are critically discussed. Highresolution spectroscopy is also related to problems in eopolymers: penultimate effects, sequence distributions, statistics, and information theory, etc. A smaller but important group of papers is concerned with the study of relaxation phenomena in natural polymers such as cellulose and proteins, as well as synthetic vinyl polymers ; topics include the theory of line broadening, the rotating-frame technique, as well as specific applications. Finally, two papers review studies in other areas of spectroscopy (infrared and electron spin resonance), and one, dielectric relaxation. As with most collections, the articles vary widely in style and emphasis. However, the articles are cross-referenced when appropriate, and relatively few errors in translation or typography are evident. The book is well produced, with many excellent figures and tables, and with a bibliography of about 400 references up to early 1970. Articles are in English or German. Certainly, the book will help fill a lamentable gap in the literature of an important subiect which has been treated in only a few monographs, and barely mentioned in most texts. Although the average newcomer to the field will also need a less specialized introduction, chemists interested in NMR per se or in problems of configuration and relaxation in polymers will find the collection to be quite valuable, as will teachers and students in advanced courses.

The authors have attempted to provide a definitive work on the dynamics and transfer processes associated with aerosol particles. In much of the material they have achieved this goal, for they have done a masterful job of organizing the large and heterogeneous body of aerosol literature by stressing the fundamental physics. The emphasis throughout is on the theoretical aspects of aerosol physics, although adequate reference is made to supporting experimental work. In the introduction, the field of study is well defined as dealing with gaseous suspensions of particles with small particle Reynolds numbers, the particles having a surface to volume ratio greater than 1000 cm-1. This rather broad definition includes within its scope high particle concentration systems, smokes, mists, and dilute clouds, as well as familiar household aerosols. Chapter 2, which deals with the molecular and statistical mechanical view of aerocolloidal systems, treats the development of the Boltzmann equation in considerable depth. Indeed the rigor is greater than required for the later applications to free molecule processes. Some fundamental hydrodynamics is discussed in Chapter 3. The classical Stokes and Oseen solutions for flow around a sphere are presented, and several problems related to the motion of spheres are examined. Among the later problems are the hindered settling of spheres (due to wall effects), motion in an electrical field, slip flow and accelerated motion of particles. Particle dePosition or capture due to hydrodynamic effects is discussed, and information on the collection efficiency for spheres and cylinders is presented. The chapter closes with a section on the deposition of particles in electrical fields. The fundamentals of heat and mass transfer to single particles by continuum theory is only covered lightly. Except for the analysis of the convective diffusion problem for small Pdclet number by Acrivos and Taylor, the authors largely ignore the rather large amount of work on unsteady state diffusion and convective diffusion done in the past decade. In this chapter and in later discussions of aerosol particle growth, much emphasis is placed on the simple quasi-steady state approximation. In this respect, the book adds only a little JOHN A. MANSON to the earlier monograph of Euchs. Department of Chemistry and To the specialist grounded in continuum Materials Research Center theory, Chapter 5 should be informative, for it Lehigh University provides much information about the limitations Bethlehem, Pa. of continuum theory as applied to aerosols. The authors review the theory of transfer processes to International Reviews in Aerosol Physics single particles in the free molecule and transition a n d C h e m i s t r y . Vol. 1. by G. M. HIDY AND regions where the Knudsen number is not suffiJ. R. BROCK, Pergamon, Elmsford, N. Y., 1971. ciently small to apply continuum theory. The next chapter, a short one, deals with the approximaxv + 379 pp. $27.00. Journal of Colloid and Interface Science, Vol. 38, No. 3, March 1972