Structured Fluids: Polymers, Colloids, Surfactants , Thomas A. Witten (with Philip A. Pincus )Oxford U. Press, New York, 2004. $74.50 (216 pp.). ISBN 0-19-852688-1
The study of soft condensed matter or complex fluids is only beginning to be an accepted sub-branch of condensed matter physics. The physics departments of some major academic institutions still do not cover it, perhaps in part because of a lack of suitable textbooks. Structured Fluids: Polymers, Colloids, Surfactants by Thomas Witten, one of the preeminent theorists in the field, represents an important and valuable contribution that should help fill the gap.
Soft condensed matter physics is the physics of materials around us, materials that we can touch, see, and feel. The study of the field should reflect this definition, and teaching it should include both intuitive and physical explanations for the materials and their properties. Yet such a task is very difficult because it requires profound knowledge about the subject. In this respect, Witten’s book excels. The author explains topics elegantly and in detail and provides a unique depth of understanding and intuition about physics. The book is full of delightful “Wittencisms”—explanations that provide tremendous insight while teaching readers how to make a valid order-of-magnitude estimate. For example, the author offers a thorough explanation of why all simple fluids have roughly the same viscosity, and he shows how to estimate the value of their viscosity from basic, physical arguments.
Soft condensed matter physics is a very broad field, and Witten does not pretend to cover all aspects of it. Instead, he focuses on topics mentioned in the title: polymers, colloids, and surfactants. He covers the subjects well and provides an excellent overview of each. Of course, the individual topics are covered more completely by other textbooks, such as Statistical Thermodynamics of Surfaces, Interfaces, and Membranes (Addison-Wesley, 1994) by Samuel Safran, which covers surfactants, and Polymer Physics (Oxford U. Press, 2003) by Michael Rubinstein and Ralph Colby.
Some topics are conspicuously missing from Witten’s book, among them foams and emulsions. Liquid crystals are discussed only briefly, in the chapter on colloids, as representing anisotropic particles. But in no way do such omissions detract from what is covered overall. For readers seeking broader coverage but at a less mathematical level, Richard Jones’s Soft Condensed Matter (Oxford U. Press, 2002) is available, which I also reviewed for the June 2003 issue of Physics Today, (page 63). Although Witten’s text lacks the depth and rigor of Paul Chaikin and Tom Lubensky’s classic Principles of Condensed Matter Physics (Cambridge U. Press, 1995), it straddles all those mentioned and provides a wonderful combination of insight and breadth of coverage.
Structured Fluids is clearly written by a theorist; nevertheless, many experimental techniques are discussed, albeit briefly. The author provides a detailed discussion of scattering, although it is in the chapter on polymers rather than the one on experimental methods. Also, for completeness, Witten includes in chapter 2 a brief introduction to statistical physics. Although that introduction will never replace a full course on the topic, it does offer enough background to make the book a self-contained textbook.
Structured Fluids is well constructed and a pleasure to read. Its text covers about two-thirds of each page, with space alongside reserved for figures and notes. Several of the chapters have lengthy appendixes in which the author discusses certain topics in more depth. Witten provides one such appendix on colloid aggregation, an area in which he has made many important contributions.
At the advanced undergraduate or beginning graduate level, Witten’s book will make an excellent textbook for a physics course on condensed matter, soft condensed matter, or complex fluids. It contains many exercises, embedded directly in the text, that are particularly apt for a course on soft condensed matter physics. They emphasize intuition and order-of-magnitude estimates over rigor and precise numerical calculations—exactly the sort of philosophy that is essential in order to appreciate modern soft condensed matter physics. Moreover, the problems sometimes entail numerical simulation and even some simple but illuminating experiments. Such features are exactly what a textbook on soft condensed matter physics should have.
I suspect Structured Fluids will be widely used and will be a must for any student of soft condensed matter physics. Even practicing condensed matter physicists will gain a great deal of insight from it, and I predict it will become a fixture on many book-shelves. It certainly is one on mine.
