Nanocrystals Forming Mesoscopic Structures Marie-Paule Pileni

It is to a discovery in 1924 on the Island of Mull in western. Scotland that we owe the name of this particular aluminosilicate mineral. One learns th...
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Cryst. Growth Des. 2006, 6, 1553-1554

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Book ReViews Mullite. Hartmut Schneider and Sridhar Komarneni, Editors. Wiley, New York. 2006. ISBN: 3-527-30974-8. List Price $220.

It is to a discovery in 1924 on the Island of Mull in western Scotland that we owe the name of this particular aluminosilicate mineral. One learns this along with many other engaging historical facts about this unique ceramic in the general introduction to Mullite. From there, the book expounds upon the geological, chemical, and engineering aspects of mullite, as well as its myriad technological applications. This book provides a treatment as comprehensive as one would expect from a 476-page tome on one single, albeit exceptional, material. The scope spans the chemistry and structure to physical properties of mullite; phase stability to synthesis and processing; and applications in coatings, fibers, and composites. The techniques and methods that have been employed over the years to examine mullite are by no means mundane. Chapter 1 on crystal chemistry includes transition metal-containing analogues as well as gels and glasses. The evidence to prove composition and structure is provided by X-ray diffraction, transmission electron microscopy (TEM), pair distribution function (PDF) analysis, and 29Si and 27Al MAS NMR. Chapter 2 also contains copious NMR data (including 11B) as well as electron paramagnetic resonance, IR, Raman, and Mossbauer spectroscopy. All of these techniques are employed to characterize mullite, as well as physical properties such as hardness, heat capacity, stress, wetting behavior, among others. Chapter 3 on phase equilibria and stability inserts optical microscopy and scanning electron microscopy (SEM) features. Mullite synthesis and processing are covered in depth in Chapter 4, which divides the various procedures into solid-state (including solution-solgel and spray pyrolysis), liquid or hydrothermal processes, and vapor phase approaches. The schematics provided are quite clear and descriptive. Processing includes sintering characteristics and properties related to mechanical, thermal, electrical, optical, and corrosion behavior. As engineering materials their refractory behavior is discussed, and as structural materials, their properties for electronic packaging, optics, tribology, filters, and catalyst supports applications are covered. At this point, the chapters on applications commence. Chapter 5 on coatings provides details on several techniques that have been exploited to deposit protective mullite coatings, including chemical and physical vapor deposition, plasma and flame spraying, aqueous slurry deposition, and self-oxidation by oxygen implantation of metal alloys. Of these, it is stated that chemical vapor deposition (CVD) and plasma/flame-spraying methods show the most promise. Growth kinetics, microstructure (SEM and TEM), phase transformations, and behavior under oxidative, corrosive, and thermal stress are all addressed. In Chapter 6, both mullite whiskers and continuous mullite fibers are described. Synthesis aspects cover whiskers from melts and gas-transport reactions, and fibers from sol-gels and melts. Finally, mullite matrix composites are covered in Chapter 7. This includes fabrication, mechanical, and thermal properties of whisker-reinforced, continuous fiber-reinforced, platelet/ particle-reinforced, and metal-reinforced (especially aluminum and molybdenum) versions. Nuts & Bolts. While edited by Profs. H. Schneider and S. Komarneni, many sections of the book are written by them as well. There are also numerous guest authors and coauthors,

presumably experts in their fields, who contribute various sections. The first chapter, on crystal chemistry, is by far the longest at 140 pages. The book is definitely balanced however. Taken together, the next two chapters covering thermodynamic properties are 109 pages. Chapter 4 on synthesis and processing is also significant at 102 pages. The final three chapters discuss various applications separately, but in sum they span 116 pages. The production quality is overall quite good. The figures are crisp and numerous; one can truly appreciate, for example, the differences in the wide variety of crystal structures possible from the projections provided in Chapter 1. The table of contents is so detailed that it can almost be used as an index on its own. One is sure to find a single particular topic of interest upon a quick glance if necessary. It is perhaps a bit difficult to navigate the numbering system employed; a more visual indenting system may have made this easier. The editors mention that this edition is meant to update one from 1994. This is accomplished in a dedicated fashion, with many new references up to and including 2005 provided, often discussed in depth. The complete reference citations including titles of the articles are especially helpful. It is hard to imagine that anything about mullite might have been inadvertently omitted. This will serve as an excellent and essential handbook to those new to the field as well as to established researchers and skilled practitioners. K. A. Carrado Argonne National Laboratory CG068003W 10.1021/cg068003w

Frontiers in Crystal Engineering. Edward R. T. Tiekink and Jagadese J. Vittal, Editors. John Wiley & Sons, Chichester, England. 2006. ISBN 0-470-02258-2. U.S. $195.00.

It is probably no coincidence that the advent of popular interest in crystal engineering can be traced back just over a decade to when CCD-equipped diffractometers suddenly emerged as standard instrumentation for small-molecule single-crystal studies. Advances in personal computing power and crystallographic software for routine structure solution, exploration, and illustration have also played a critical role in the development of the field. Crystal structure analysis has become accessible to the nonspecialist, and as a consequence, crystal engineering is growing from strength to strength with a wide variety of distinct themes being represented. There is now enough information in the recent literature to fill many volumes on crystal engineering, and a boldly worded title such as “Frontiers in Crystal Engineering” is a tall order to fulfill in a book consisting of only 320 pages. In this regard, the editors have acquitted themselves extremely well. They have assembled an eclectic collection of 12 chapters by some of the most recognized personalities in the field. In the foreword, Gautam Desiraju states that this book “...is likely to be useful to both entrants to the field as well as to established practitioners, and demonstrates the variety of approaches that are being used to tackle the many difficult problems associated with complexity, design and functionality of crystalline molecular solids.” I am inclined to agree with this statement. While the book may not (and indeed, cannot) be comprehensive, it offers a tantalizing

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smattering of some of the most important current themes of crystal engineering in a highly digestible format. Every serious laboratory engaged in crystal engineering studies should have access to a copy. Leonard J. Barbour Department of Chemistry UniVersity of Stellenbosch South Africa CG068004O 10.1021/cg068004o

Nanocrystals

Forming Mesoscopic Structures. Marie-Paule Pileni, Editor. Wiley, New York. 2006. ISBN 3-527-31170-X. U.S. $175.00.

When I got the book entitled “Nanocrystals Forming Mesoscopic Structures” edited by Marie-Paule Pileni for a short book review, I was looking for an introduction in which the motivation to edit this book is described. I was surprised that an introductory chapter is completely missing and that the interested reader only finds some information on the backside cover of the book. This very short paragraph can only introduce quite a bit in the important field of the self-assembling of nanostructures. To get an overview on this important research field, I would have preferred an introductory chapter in which the state-of-the-art knowledge on nanoparticles, their properties, and their applications is given as well as a justification of the next step, i.e., the self-organization of nanoparticles to form mesoscopic structures. The book consists of 13 chapters. Most of the chapters end with a conclusion, which summarizes shortly the key information. In Chapter 1, it is explained which intramolecular forces have to be considered for self-organization. This chapter is well-written, and it is demonstrated at selected examples that both a narrow size distribution of nanoparticles and a substrate/particle interaction influence long-range selfassembling. Chapters 2 and 3 deal with magnetic nanocrystals. Although both chapters nicely introduce the synthesis and importance of magnetic nanoparticles and their self-assemblies, I am a bit surprised that superparamagnetism and its size dependence is hardly discussed. More information on superparamagnetism can be found in Chapter 10. Furthermore, I would have expected some comments on naturally selfassembled magnetic nanoparticles, e.g., in magnetotactic bacteria. Despite this shortcoming, the experienced reader gets in these three chapters a good introduction in the importance of self-assembled magnetic nanostructures. Chapters 4 and 5 are devoted to the fabrication of nanoparticles and their threedimensional self-assembling in solid matrices. Just for technical considerations, e.g., in the case of optical devices, nanoparticles need self-organization without agglomeration. In both chapters, the challenges but also the perspectives are well-described at selected examples and the reader gets a good starting point for this fascinating field. Chapter 6 gives some insights into structured polymers on the micro- and submicroscale. In my

opinion, this chapter is not directly related to the title of the book, but it describes how even in microscale polymeric structures nanoscale effects have to be expected. Further ideas on this aspect are given in Chapters 11 and 12. I personally very much liked reading Chapter 7 in which an introduction in mineral liquid crystals is given. The authors explain well the basic principles and give a very short introduction in investigation techniques. At the example of V2O5, they explain the influence of a magnetic field on alignment. I like in this chapter that it is shown that the field of mineral liquid crystals has a lot to do with self-assembling of nanostructures although at the first glance it might appear to be a bit old-fashioned. In the short Chapter 8, the authors give an introduction in collective properties of self-organized silver nanoparticles. The key information is that there are coupled plasmon modes due to induced dipole-dipole interactions. Personally, I think that this chapter is rather an extended full paper than a book chapter; furthermore, the quality of the STM pictures in Figure 8.16 is not really convincing. Maybe the pictures were taken from a Master’s thesis as the x- and y-axes are labeled in French. The same picture can then be found in Chapter 9, Figure 9.6, now with English labeling of the x- and y-axes. Here, it is also demonstrated that silver nanoparticles show collective plasmon modes. Although the application of the STM tip in scanning tunneling luminescence is demonstrated, I would have expected higher quality STM pictures or at least a good explanation of why the picture quality is below the usual standard. In Chapter 11, Janos Fendler gives a very short introduction in selfassembled monolayers and how to build up nanoparticle layers with polyelectrolytes. With gold nanoparticles but also with single-stranded DNA, such thin films are pretty interesting for surface plasmon sepectroscopy. Nanolithography with colloids gives access to nanostructured surfaces with defined roughness and periodicity as described in Chapter 12. This chapter gives a nice introduction in patterning by self-assembly without neglecting limitations, such as the still limited periodicity over a large area. Much more effort will be necessary in this field to compete with electron lithography. At first glance, the last chapter of this book seems to be out of place, as shrinkage cracks are discussed on both a macroscopic and a microscopic scale. However, it is demonstrated that with nanoparticles applied to surfaces such shrinking has to be expected and that for practical considerations such shrinking can be disadvantageous. As a conclusion, I personally think that this book is interesting for experienced readers who have a good background of nanotechnology. The different chapters give an introduction in selfassembly so that the experienced reader has a good starting point. However, a later second edition should be strongly improved and also introduce basic principles of nanotechnology. Frank Endres Clausthal-Zellerfeld CG0680069 10.1021/cg0680069