BOOH R€V#Wf
Introduction t o Powder Surface Area S. Lowell. John Wiley 8 Sons, New Ywk. NY. 1979. vii 199 pp. Figs. and tables. 15.6 x 23.5 cm. $17.95. Lowell states in the preface that his baok "is intended as an introductionto some of the elementary t h e w and experimental methods used to study the surface area and porosity of solid surfaces" and that "it may be found useful by those with linle or nohaining in solid surfaces who have the need to learn quickly the rudiments of surface area and pore size measurements." This is an accurate assessment of the book's contents and probable
+
,,en
The determination of powder surface area is not a vigorous field of research. 01 the 133 literature references in the book's bibliography, only 14 bear publication dates from the last decade. The theory of Brunauw, Emmett. and Teller (BET Uecfy)was developed over 40 years ago and still SeNeS as the theoretical basis for most surface area measurements. Nevertheless, the practical aspects of surface area measurements are of importance to people in industries concerned with finely divided materials and the book could be of considerable assistance to them. Except for his frequent use of dangling phrases, lhe auihor writes clearly and direclly. There is a refreshina economv to his stvle. Once he moves oromotlv on . ~- a mint is made. ~~~. to then&. in onb 189 pages 01t& &'is h e to discuss a relatively large number of topics. Some, like the HarkinsJura methods for surface area measurement. are treated lightly. Others, the BET method for example, are d i 5 cussed in great detail. In addition to topics which the title would lead one to exoect. ttm book contains brief discuss~ons01 peripheral suojects suchas the measbrement of powder dens~tyand the contact angle for mercdry on a smooth bed of powder
-
~
~
~
Like many first editions, the book contains emns of printing and of fact. Fwtunately, most will not ueate serious problems for the reader. Examples of printing errors are the following. Eouation 15.331 is mislabeled 15.231. Eouatio'ns 18.7j ana j8 7al should inio~vein (pip,) rather than (In P)IPo. In F~gure8-1, the fmai state should consist 01 1 g solad immersed in a moles liquid instead of Ig soiid immersed in a moles vapor. The sign usage in this figure is unconventional. The explanation on page 41 of the factor is in1.09 in the equation A = 1.09 correct and should be ignwed. Emmett and Brunauer offered this relationshio in 1937 as a means of estlmat ng lhe crosssectionalarea A of an adsorbate molecule from the lhquld molar volume Vand Avogadro's number N It is based on the assumptions that lhe adswbate molecules are spheres, that they have a hexagonal ClosPpacked arrangement in the liquid state, and that their structure on the solid surface is the same as in a layer of liquid adsorbate. The author anemots to exolain the 1.09 lacta wnth a sectional hew of a'close-packed hexagonal arrangemenr of spheres (Fig. 7-11 and !he clam that the length of a row of four touching spheres is 1.09 times the width of four rows. (The text says three rows.) The ratio of length to width for any sectional segment containing as man rows as there are spheres inarowis2nl[&n-I)+2],wherenisthe number of spheres in a row. For nvaluesof 3 and 4. the corresoondina ratios are 1.098 and 1 112 As n approaches mfmty. the ratlo approaches 1 155 Obvno~sly,F~gure7-1 cannot serve as the bas6 for an explanatron of the factor 1.09. In hexagonal close packing, the distance between the centers of two adjacent spheres in a row is the diameter D. The distance between the lines of centers in two adjacent rows in the same layer is & ~ / 2 . The distance between planes of centers in two adjacent Hence, in a cube of edge layers is
-
GD.
V'I3 filled with Nspheres of diameter D i n a hexagonal close acked arrangement, there will be V/~/&$D layers, each containing (V'13/D) X (V'13/~.5&D) = 2 v ~ ' ~ / & D ~ spheres (edge corrections ignored). The
Slightly less than half of the book is devoted to experimental procedures and instrumentation. Since much of the information provided here is not readily available in the literature, its collection and publication in one place is a valuable contribution. E. W. Anacker
f&n@m State University Bozeman. m 5 9 7 1 7
Megawatt Infrared Laser Chemistry Ernest Gfunwald, David F. Dever, and Philip M. Keehn, John Wiley 8 Sons, inc. NY. 1978. xii 107 pp. Figs. and tables. 23.5 X 16 cm. $15.00.
+
The authors intended to prepare a volume that would serve .as a greetingta new workers in the field and as a primer to acquaint chemists in general with salient features of the phenomenon." They have, in my opinion, succeeded. The reader should be aware, however, that the authors have a "chemistry" point of view, and the book treats only one part of the broad, interdisciplinary topic of the interaction of infrared laser radiation with polyatomic molecules. The book is already more than two years old. However, the authors' wise decision to emohasize exoerimental observations aver ephemeral theoretical explanations has re(Continued on page A346J
"..
Reviewed in this Issue Reviewer
S. Lowell, Introduction to Powder Surface Area E Grunwald, DavidF. never, and Philip M. Keehn, Magawatl Infrared Laser
E. W. Anacker John L. Lyman
Chemistry New Volumes in Continuing Series
A345 A345 A346
Volume 58
Number 11
November 1981
A345
