摘要:

J. Chem. SOC., Faraday Trans. I, 1984,80, 1645-1650 Mechanistic Study of the Catalytic Hydrogenolysis of Ethane BY SANDOR KRISTYAN Institute of Isotopes of the Hungarian Academy of Sciences, P.O. Box 77, H-1525 Budapest, Hungary AND JANOS SZAMOSI* Department of Chemistry, The University of Texas at Arlington, P.O. Box 19065, Arlington, Texas 76019, U.S.A. Received 17th October, 1983 A mechanistic investigation of the hydrogenolysis of ethane is presented. The chemisorptions of ethane and hydrogen produce a common surface species, adsorbed hydrogen, and the coverages of the two-carbon-atom surface compound and the adsorbed hydrogen are inter- dependent through the partial pressures of ethane and hydrogen. The kinetically slow rupture of the C-C bond takes place in an interaction with a free site, adsorbed hydrogen or molecular hydrogen.Based on a theoretical analysis and previous experimental results, our conclusion is that molecular hydrogen is the most probable agent in the bond splitting. The reaction equation catalyst C2H6 +H, -2CH, illustrates the catalytic hydrogenolysis of ethane to methane over a metal catalyst (Ni, Pd or Co). Experirnent~~-~ have indicated that the reaction rate is a function of the partial pressures of hydrogen and ethane. (It is possible to vary the partial pressures individually by adding an inert gas such as He to the gas mixture.) The rate is proportional to the partial pressure of ethane, up to a limit; beyond that the rate can be enhanced further only by altering the partial pressure of hydrogen.When the dependence of the reaction rate on the partial pressure of hydrogen is investigated, it is found that the rate goes through a maximum: the reaction is very slow if too much or too little hydrogen is present. Even though most experiments have had the same outcome, none of the proposed mechanisms can fully account for the observed phenomena. Sinfelt and Taylor1* assume that the initial chemisorption of ethane gives an adsorbed ethyl radical which is not in equilibrium with ethane gas. The adsorbed C,H,* then undergoes further dehydrogenation to C2HZ, such that an equilibrium is maintained between C,H,* and C,HZ (rn is defined later). The rate is given by r = kpE/(l + bp,), where pE and pH are the partial pressures of ethane and hydrogen, respectively, and b is a positive number arising from the equilibrium constant and rate constants.The function r does not account for the facts that the reaction is slow at low H, pressure and that the rate cannot be enhanced limitlessly by simply increasing the partial pressure of ethane. In Martin’P8 blocked coadsorption mechanism, adsorption of ethane is the rate-determining step. This can be ruled out, since experimental results clearly indicate1* 5 9 that the chemisorption step reaches equilibrium almost instantly. 16451646 CATALYTIC HYDROGENOLYSIS OF ETHANE Most of the assumptions about the reaction mechanism made by Forster and Ottos cannot be disputed; however, it is not necessarily true that C-C bond-splitting occurs via a Langmuir-Hinshelwood mechanism with adsorbed hydrogen.Their proposed rate is inversely proportional to the partial pressure of hydrogen. We have tried to include all possible factors and made our judgement by analysing the obtained rate functions. Both earlier and recent5 experimental results show good agreement with our model. DISCUSSION Hydrogen-deuterium exchange experiments3y have proved that both ethane and hydrogen are adsorbed dissociatively but that the C-C bond is preserved in this step. Furthermore, it is probably a good assumption that only one C atom of the C,HZ surface compound participates in surface bonding.O* lo We must take into account that the hydrocarbon coverage, 8, (of C,H3, and the hydrogen coverage, OH, are interrelated. If the partial pressures of H, and C,H, are varied, the coverages could change dramatically (8, the coverage, is the fraction of all sites occupied by a species). We note that the adsorbed hydrogen comes partially from the chemisorption of ethane, further complicating the mechanism.The proposed mechanism is as follows. The first step is the adsorption of the ethane + hydrogen gaseous mixture. Step I (fast): KE KH C2H6+(7-m)* +C2H;+(6-m)H* H,+2* t 2H* where * indicates surface site and m is the number of hydrogen atoms remaining on the two-carbon-atom surface compound. The two equilibrium constants are given by where 8, and 8, are the coverages of C,Hk and hydrogen, respectively, 8, is the fraction of free sites, and pE and pH are the partial pressures of ethane and hydrogen, respectively. Step I1 (slow): k C,Hk + B + CHG + CHt.The reaction is irreversible; B is either a free site (*), adsorbed hydrogen (H*) or gas-phase molecular hydrogen (H,). The last step is the formation of methane by hydrogenation of the one-carbon-atom surface compounds with adsorbed or molecular hydrogen. Step 111 (fast): CHtS. KRISTYAN AND J. SZAMOSI 1647 Table 1. Comparison between calculated and measured (Ni catalyst, 250 "C) rate values ratelpmol g(catalyst)-' s-l 9.4 4.1 0.30 0.013 3.9 3.48 9.4 1.8 0.13 0.019 2.5 2.83 4.7 3.3 0.32 0.066 2.9 2.45 2.9 4.1 0.28 0.064 2.1 1.79 1.2 1.8 0.34 0.050 1.5 1.18 Assuming that d[O,]/dt = d[O,]/dt = 0, the rate is given by r = k0,B. (3) Since the third step is fast, coverages of the one-carbon surface compounds are negligibly small; the sites are either free or occupied by adsorbed hydrogen or C,Hg : o o + o ~ + e m x 1 .We now introduce the following new variables : Y = KEpE x = (KHPHP G6 = ~ 6 - m G7 = ~ 7 - m . Using eqn (l), (2) and (4) the coverages of interest are: ' 0 = G6/(Y + G6 + G 7 ) Om = Y / ( Y + G6 + G7) O H = G7/(y+ G6 + G7)' Depending on the identity of B, the possible rate equations are as follows: if B = B0; if B = 8, ; r = kyG,/(y+G6+G7)2 Y = kyG7/( y + G, + Gp)2 if B = p H ; r = k y p ~ / ( y + G , + G , ) . RESULTS Analyses of eqn (8)-( 10) show that ifp. is kept constant, r goes through a maximum in all three cases if rn = 0-5; however, if pE changes, the rates given by eqn (8) and (9) do not show the experienced proportionality between the rate and the partial pressure of ethane. At the same time, eqn (10) clearly indicates that the rate grows with pE and that the increase is not limitless.In a recent experiment5 with Ni catalyst at 250 "C the partial pressures of hydrogen and ethane were varied between 0.5 and 10 kPa. The following results were obtained. (i) The rate constant is k z 1.56 pmol g(catalyst)-l kPa-l s-l. (ii) The equilibrium constants are KH = 1.3 x dm3 kPa-'. (iii) The rate is never inversely proportional to the partial pressure of ethane, even if only a dm3 kPa-l and KE = 5.8 xv1 - I n Y w - Y m 00 W CATALYTIC HYDROGENOLYSIS OF ETHANE 0.15 r 40 50 60 30 P H /kPa \ 30 * I v1 - h I U w - cd Y m M W I I I I I J 10 20 30 0 40 50 60 -;i 0 I I - 40 50 60 0 10 20 30 Fig. 1. Simulated reaction rate, r, plotted against partial pressure of hydrogen, p H , with p E , the partial pressure of ethane, kept constant at 10, 20 and 30 kPa.(a) Eqn (8), (b) eqn (9) and (4 eqn (10).S. KRISTYAN AND J. SZAMOSI 1649 2.0 0 ' I I J 0 5 10 15 PElkPa Fig. 2. Simulated reaction rate, r, plotted against partial pressure of ethane, p E , with the partial pressure of hydrogen kept constant at 5 kPa. very small amount of hydrogen is present; i.e. the curves never cross each other. (iv) The maxima in plots of rate against pH occur at higher pH values as the ethane pressure grows. (v) Rate measurements with Pd catalyst at 350 "C exhibit essentially the same feature^,^ although the parameters differ: k = 1.18 pmol g(catalyst)-l kPa-l s-l, KH = 0.74 dm3 kPa-l and K , = 0.73 dm3 kPa-l. The results of other experiment+ 3 9 are consistent with the above findings.Using Simplex curve-fitting Kristyanll has confirmed (iii) and (iv) above. In addition, rn has been determined for both catalysts: it is probably 2 in the case of Ni catalyst and 3 in the case of Pd. We have calculated the three possible rates with the parameters given by (i), (ii) and (v) at different pressures and compared them with experimental data.5 Table 1 shows that eqn (10) correlates very well with the measured values; at the same time the rates obtained from eqn (8) and (9) are always substantially lower than the corresponding experimental results. Comparison between the computed and the measured values in the case of Pd catalyst has also proved that only eqn (10) describes the rate satisfactorily. Our opinion is that in the rate-determining step it is the gas-phase (more exactly non-chemisorbed) hydrogen whose interaction with the two-carbon-atom surface compound brings about the rupture of the C-C bond.Beside the good quantitative correlation between the experimental results and eqn (10) the proposed mechanism is supported by a closely related experiment. Galway's research12 on the hydrogenation of nickel carbide has shown an almost linear dependence of the reaction rate upon the partial pressure of hydrogen, indicating that in a system similar to ours the mechanism is of the Rideal type. Fig. 1 (a) [eqn (S)], (b) [eqn (9)] and ( c ) [eqn (lo)] illustrate the three possibilities. The rate curves have been simulated by using k = 1.6 pmol g(catalyst)-l kPa-l s-l, KH = 1.5 x dm3 kPa-l, i.e.the rounded values of the parameters obtained from the experiments with the Ni catalyst. Thep, varies from 0 to 60 kPa, and each figure has three curves with p , taking the values 10, 20 and 30 kPa. Only fig. 1 ( c ) exhibits the characteristics described under (iii) and (iv) above. Fig. 2 shows the rate dependence on p , , using eqn (10) with a constant hydrogen pressure of 5 kPa. It is clear that the rate increases with p,, up to a limit. dm3 kPa-l and K , = 6 x1650 CATALYTIC HYDROGENOLYSIS OF ETHANE CONCLUSION In this mechanistic study we have focused our attention on the determination of the C-C bond-splitting agent, which is the most crucial problem of the whole mechanism. A comparison between the measured and the calculated rate values and an analysis of the possible rate functions indicate that the kinetically slow rupture of the C-C bond takes place in an interaction with molecular hydrogen. We gratefully acknowledge the support of the R. A. Welch Foundation. J. H. Sinfelt and W. F. Taylor, Trans. Faraday Soc., 1968, 64, 3086. J. H. Sinfelt and W. F. Taylor, J. Catal., 1977, 27, 468. L. Guczi, A. Sarkany and P. Tetenyi, J. Chem. Soc., Faraday Trans. 1, 1974, 70, 1971. L. Guczi, B. S. Gudkov and P. Tetenyi, J. Catal., 1972, 24, 187. A. Sarkany, P. Tetenyi and S. Kristyan, to be published. G. A. Martin, C.R. Acad. Sci., Ser. C, 1977, 284,479. ' G. A. Martin and B. Imelik, Surf. Sci., 1974, 42, 157. G. A. Martin, J. Catal., 1974, 60, 345. H. Forster and H. J. Otto, 2. Phys. Chem., N.F., 1980, 120, 223. 1977). lo J. R. Anderson, Chemisorption and Reaction on Metallic Films (Academic Press, London, New York, l1 S. Kristyan, DSc. (Tech.) Dissertation (Technical University of Budapest, 1982). l2 A. K. Galway, J. Catal., 1962, 1, 227. (PAPER 3/ 1844)

ISSN:0300-9599    

DOI:10.1039/F19848001645

出版商:RSC    

年代:1984

数据来源: RSC

摘要:

J . Chem. SOC., Faraday Trans. I , 1984,80, 1651-1655 Kinetics of Reactions Involving Three Organic Substrates in Microheterogeneous Systems BY MICHAEL J. BLANDAMER,* BARBARA CLARK AND JOHN BURGESS Department of Chemistry, The University, Leicester LE 1 7RH AND JOHN W. M. SCOTT Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada Received 25th November, 1983 The rate constants have been obtained for reactions of Crystal Violet, Malachite Green and 2,4-dinitrochlorobenzene with hydroxide ions in two aqueous microemulsions. The rates of reaction are significantly faster than in the corresponding aqueous solutions. For the reaction involving the chlorobenzene, kinetic evidence is reported for a two-state reaction. The catalysis is assigned to interphase effects in the microheterogeneous system.The rates of reactions1 of two low-spin iron(1r) complexes with hydroxide ions in certain aqueous mixtures are significantly faster than in the corresponding aqueous solutions. This acceleration was interpreted in terms of microheterogenity in these aqueous systems combined with catalysed reaction at an interphase. In this paper we report kinetic data for reaction in these same systems between hydroxide ions and Crystal Violet (CV), Malachite Green (MG) and 2,4-dinitrochlorobenzene (DNCB); the kinetics of the aquation reaction for CV and MG in these systems are also commented on, together with qualitative observations on the corresponding reactions with cyanide ions. Again, for reactions involving hydroxide ions, a marked increase in the rate of reaction is observed over that in aqueous solution.The reactions involving CV and MG are first order in organic substrate but the dependence of rate constant on [OH-] is not linear. The dependence of [DNCB] on time is analysed using an equation involving two exponential functions of time. This observation is discussed in terms of the mechanism of reaction. EXPERIMENTAL MATERIALS The kinetics were examined in two aqueous microemulsions prepared as described previously.' Medium A comprised 60 mol % 2-butoxyethanol+20 mol % decane and 20 mol % water. Medium B comprised 40 mol % hexane + 45 rnol % propan-2-01 + 15 mol % water. DNCB, CV and MG were purified as described KINETICS The rates of reaction were measured at 298 K using the method described previously.2 The reactions involving CV and MG were monitored by following the disappearance of reactant at 579 and 625 nm, respectively. The reaction involving DNCB was monitored by following the appearance of the corresponding phenol at A = 358 nm.In these experiments the computer-controlled spectrophotometerl was instructed to collect data at two sets of time 16511652 KINETICS IN MICROHETEROGENEOUS SYSTEMS intervals. The first set comprised data at short time intervals; the second set described longer time intervals. This procedure was necessary in order to delineate two time constants characterising the overall reaction (uide infra). KINETIC ANALYSIS As a preliminary to the presentation of results we consider the kinetics of the following reaction scheme k,*[OH-] k3 X X OH -products.(1) k2 In the limit [OH-] 9 [XI, the product k,*[OH-] can be replaced by a first-order rate constant k,. The algebra is simplified if we set [XI = a, [x - OH] = b and [products] = c. For the experiments reported here, at t = 0, a = a", b" = 0 and co = 0. Hence4 and c/ao = 1 Y 2 - Y 1 -(a)exp(-y,t)-(")exp(-y,t) Y1-YYz (3) where y1 and y, are the two roots of a quadratic equation' in k,, k, and k,. follows first-order kinetics The dependence of c on time is given by In the limit that k, 9 k , (i.e. a consecutive reaction), the dependence of a on time (4) a = ao exp (-k,t). k3 ciao= l-(-)eXP(-klt)- k3 - kl (A) exp(-k3t). ( 5 ) In the limit that k, 9 k, and either k, $= k, or k3 9 k,, the dependences of a and c on time are determined by first-order rate constants.For the case where the appearance of products follows either eqn (3) or (9, the dependence on time conforms to the following general equation : (6) For both cases, the condition is that a,/a, = p2;/p1. However, the meanings attached to these quantities differ. If the quantity c is determined by the absorbance at wavelength il where the extinction coefficient is E , the dependence of absorbance P on time t is given by c/ao = 1 - a, exp ( -p2 t) - a, exp ( -pl t). p = g,-g, exp ( - I 3 2 0 3 3 exp (-A 0. (7) Hence at time t, P is a function of five parameters: g,, g,, g3, p1 and p,. The computer analysis used the Wentworth method5 to calculate' by an iterative method the five unknown parameters starting out with initial estimates (or guesses). It is important to measure P over times where first p1 and then p2 dominate the time dependence of P, otherwise the least-squares analysis5 allows one exponential term to dominate, assigning residual scatter to the other exponential term.In certain cases the dependence of P on time could be fitted by a single-exponential function. These data were analysed in terms of a single first-order rate constant.M. J. BLANDAMER, B. CLARK, J. BURGESS AND J.W.M. SCOTT 1653 1.0 2.0 3 [ NaOH] / 1 0'3 mol dm-3 Fig. 1. First-order rate constant for reaction between Crystal Violet and hydroxide ions in medium B. RESULTS The kinetics of reaction in media A and B are complicated. Furthermore, where the rate of reaction is accelerated over that in more conventional aqueous solutions, the rate of reaction is often extremely fast and can therefore present a number of practical problems.In certain cases it proved impossible to lower [OH-] and thereby slow the rate to within manageable limits. The complexity of the systems (e.g. microheterogenity) was evident because at the other extreme the solutions became opaque at high concentrations of added hydroxide and cyanide. We confine our attention to systems which are clear and transparent, at least in the visible region. At 298 K, in medium B the reaction between CV and hydroxide ions follows first-order kinetics; k = 1.2 x 10-l s-l where [OH-] = 8.99 x lo-* mol dm-3, which corresponds to an effective second-order rate constant of 133.5 dm3 mol-l s-l.The corresponding second-order rate constant in aqueous solution is 2 x 10-l dm3 mol-l s-l. For a simple bimolecular process, the first-order rate constant should be a linear function of [OH-]. This is not the case for the reaction between CV and OH- in medium B (see fig. 1). The shape of the plot points to some degree of saturation in the catalysis. The reaction between CV and cyanide ions in this medium was also very fast; it was impossible to characterise the rate using the available apparatus. The acceleration in rate is comparable to that observed for the reaction with hydroxide. Only a modest change in the spontaneous rate of aquation3 was noted. A similar enhancement of rate was observed for the reaction between OH- and CV in medium A; e.g. k , = 0.74 x 10-1 s-l where [NaOH] = 5 x lop4 mol dm-3.The dependence of k , on [NaOH] is marked. A modest increase in [NaOH] to 5.5 x mol dm-3 produced an increase in k , to 2.5 x 10-1 s-l. Further increase in [NaOH] resulted in a rate of reaction which was too fast for us to measure, i.e. A pattern similar to that described above was observed for the reactions involving MG. In practice the rates of reaction involving OH- and CN- were extremely fast k, > 1.0 s-l.1654 KINETICS IN MICROHETEROGENEOUS SYSTEMS / / i I I / I I I I 0 1 .o 2.0 3.0 [NaOHl mol dm-3 Fig. 2. Dependence of rate parameters [PI(-) and p2(---)] on [OH-] for reaction with 2,4-dinitrochlorobenzene in medium A. and we can only estimate that the second-order rate constant for these reactions in media A and B are > 200 dm3 rnol-l s-l (cf.1.24 x and 5.9 x lo-* dm3 mol-1 s-l for reaction with OH- and CN-). In the experiments described above the kinetics of reaction could be accounted for by a single rate constant. Such was not the case for reaction between OH- and DNCB in medium A when [OH] < 7 x mol dm-3. Under these conditions the data were fitted to eqn (6). With increasing [OH-], both and p2 increase (see fig. 2). However, when [OH-] > 7 x mol dm-3, the kinetics of reaction revert to a simple pseudo- first-order process. The large limits on the second rate parameter in fig. 2 reflect the experimental problems in identifying the two rate parameters in a statistically meaningful fashion. The fact that the data points for p1 and k fall on a continuous curve indicates that the p2 component continues to increase.The kinetic data over the range 3 x < [OH-]/mol dm-3 < 7 x satisfied the criteria set by eqn (3) and (5). Over nine independent measurements, pl/& = 0.24k0.08 and al/a, = 0.23k0.06. Where the data fitted a single first-order rate constant, the calculated second-order rate constant is significantly faster than that for aqueous solution2 (e.g. 1.3 x lov3 dm3 mol-1 s-l at 318 K). However, this calculation can be misleading because the measured first-order rate constant in medium A is not a linear function of [OH-]. Again there is a trend towards saturation with increase in [OH-], as shown in fig. 2. Nevertheless the enhancement in rate of reaction is dramatic if difficult to quantify. DISCUSSION The extent to which the rates of the chemical reaction reported here are enhanced by conducting the reaction in a microemulsion is in itself remarkable. However,M.J. BLANDAMER, B. CLARK, J. BURGESS AND J.W.M. SCOTT 1655 quantitative treatment of microemulsion catalysis is not straightforward. Previously we explained the complicated kinetics of reaction between OH- and an iron(I1) complex in terms of catalysis at an interphase. In these terms, the microheterogeneity of microemulsions is central to their catalytic function. Various aspects of the data reported here support this conclusion. The non-linear dependence of the first-order rate constant on [OH-] for a bimolecular process points to the rate constant being a composite of parameters describing a number of different processes, e.g.competition for sites at a surface where reaction occurs.1 Previouslyf we found that the kinetics of reaction involving an iron complex in certain systems could be described by an equation which contained both zero- and first-order components. These observations pointed directly to a surface-catalysed reaction. For the reactions reported here the evidence is less strong but the combination of acceleration in rate and complexity of the dependence of k on [OH-] points to a similar surface-based reaction. In reviewing the kinetic data it is important to bear in mind how the kinetic parameters are obtained, i.e. the ‘reporter’ of the reaction. Thus for the reactions involving CV and MG, the rate constants were obtained by monitoring the dependence of reactant, a, on time [eqn (2) and (4)].In terms of the reaction scheme given in eqn (I), we can only exclude the conditions required by eqn (2). However, for the reaction between OH- and DNCB the reporter is the product of reaction, Where two kinetic parameters (e.g. PI and PZ) are identified, the data can be understood in terms of either eqn (3) or (5). In both cases the overall rate of reaction is determined by parameters describing the formation and decomposition of an intermediate. In other words, the reaction between DNCB and OH- proceeds via an intermediate. For reaction in aqueous solution the kinetics of reaction can be described by a single rate constant. However, there are good grounds for writing the mechanism of reaction as two stage;6 the first stage involves the formation of the [DNCB - OH]- carbanion where both C1 and OH are bonded to the aromatic ring through the same carbon atom. It is tempting to understand the kinetics of reaction reported here in terms of the production of this intermediate at the interphase. If this assignment is correct, kinetics of reaction in microemulsions may have an important r6le to play in mechanistic studies. The distribution of polar and non-polar reactants, products and intermediates between polar, non-polar and interphase regions could decouple rate parameters in an informative fashion. We thank the S.E.R.C. for a maintenance grant to B.C. ’ M. J. Blandamer, B. Clark, J. Burgess and J. M. W. Scott, J . Chem. SOC., Faraday Trans. I , in press. M. J. Blandamer and D. J. Reid, J. Chem. SOC., Faraday Trans. I , 1975, 71, 2156. K. Hillier, J. M. W. Scott, D. J. Barnes and F. J. P. Steel, Can. J. Chem., 1976, 54, 3312. M. J. Blandamer, E. Ralph, J. M. W. Scott and R. E. Robertson, J . Chem. Soc., Faraday Trans. 1, 1983, 79, 1289. W. E. Wentworth, J. Chem. Educ., 1965, 42, 96. C. A. Bunton and L. Robinson, J . Am. Chem. SOC., 1968,90, 3972. (PAPER 3/2095)

ISSN:0300-9599    

DOI:10.1039/F19848001651

出版商:RSC    

年代:1984

数据来源: RSC

摘要:

Reviews of Books Studies in Modern Thermodynamics, Volume 4. Principles Characterizing Physical and Chemical Processes. By J. M. HONIG. (Elsevier, Amsterdam, 1982). Pp. x+441. Price: $1 11.50, Dfl 240. This is an advanced student text based, in part, on a graduate course given by the author at Purdue University. The approach taken is axiomatic and draws extensively on the ideas of Caratheodory. It is heavily mathematical and quite clearly is not intended for the beginning student . Having presented the fundamental material in a concise but readable way, the author moves on to consider the elementary applications of thermodynamics in what can only be called a rambling, disorganized manner. I found the way in which he intermixed material which is always true with that which is true only for ideal systems (gas or mixture) particularly confusing.Thus, for example, the chapter headed ‘Equilibrium in Ideal Systems’ contains the derivation of the phase rule and the phase behaviour of real single-component systems, neither of which is discussed elsewhere in the book. However, far more serious is the way in which the author derives a result for a particular ideal system and uses this later without indicating that the constraint still holds. A student dipping into this book is at risk of picking up and using equations or information without being aware of the restrictions applying to them. The author also seems to have some odd ideas as to what constitutes an ideal gas. He asserts that the heat capacity, C,, for an ideal gas is independent of temperature, but a few pages further along he allows Cp to vary with temperature, having, in the meantime, proved that C, - C, = R.The section on real systems and, in particular, the use of standard states is one of the most opaque I have ever come across. In the preface, the author says that one of the ways that his text differs from conventional treatments of thermodynamics is in his ‘ detailed investigations on the uniqueness of predictions of properties of solutions, in the face of a bewildering array of standard states’. He certainly seems to have done this, but perhaps not quite in the way he intended. I suggest therefore that the reader skips chapters 2 and 3, where all this confusion is to be found, and moves on to the last third of the book, which is much more valuable and well written.The chapters here cover: (4) Properties of Electrolytes; (5) Systems in External Fields- Gravitational Fields, Adsorption, Radiation, Electrical Fields, Superconducting Materials, and (6) Irreversible Thermodynamics. These topics are rarely covered in a textbook of this type and the discussion is at just the right level to provide a knowledgeable introduction to these more specialized parts of the subject. The price can only be considered exorbitant, particularly for a book produced photo- graphically from typescript. G. SAVILLE Received 21st September, 1983 Membrane Mimetic Chemistry. By J. H. FENDLER. (Wiley-Interscience, New York, 1982). Pp. xi + 522. Price E46.75. ‘ Membrane mimetic chemistry’ is a relatively new but rapidly expanding field of science at the interface between chemistry and biology.Prof. Fendler’s pioneering work in the area is well known, so this book is most welcome, providing as it does both an authoritative introduction and survey for those newly entering this fascinating area of research, and a comprehensive review of the relevant literature up to the middle of 198 1. The title is perhaps a little misleading in that most model membrane studies are undertaken with the aim of gaining some insight into the structure and function of more complex natural 16571658 REVIEWS OF BOOKS membranes. Prof. Fendler, on the other hand, has chosen to concentrate on the abilities of so- called ‘membrane mimetic agents ’ [a term used to describe organised molecular assemblies such as micelles, microemulsions, monolayers, bilayers and vesicles as well as host-guest systems (crown ethers, cyclodextrins and related macrocyclic compounds) and polyelectrolytes] to mediate and catalyse chemical reactions.The relationship between some of these systems and biological membranes is somewhat tenuous; since it is their catalytic properties which are under consideration, polyelectrolytes and cyclodextrins for example might be more appropriately termed ‘enzyme mimetic systems’. The book is divided into two parts, the first dealing with the characterisation of membrane mimetic agents and the second with their applications. Part 1 opens with a brief introduction to the structure of biological membranes; this is followed by seven chapters each devoted to one of the membrane mimetic systems.Aqueous micelles, reversed micelles and microemulsions, surfactant monolayers and multilayers, bilayer ‘ black ’ lipid membranes, surfactant vesicles and liposomes, host-guest systems and polyelectrolytes are all described and reviewed in some detail. This section of the book gives a useful introduction to the basic physical chemistry of these systems whilst providing numerous references for readers who wish to extend their background knowledge. Each chapter is followed by an extensive and up-to-date bibliography ; the inclusion of titles in cited references is particularly welcome. Part 1 is concluded by a short and especially helpful chapter in which the properties of the different membrane mimetic agents are summarised and compared.Part 2 deals with the practical application of membrane mimetic agents and comprises chapters entitled ‘Enzymes and Membrane Mimetic Systems’, ‘ Reactivity Control and Synthetic Applications ’, ‘ Data Tabulation for Reactivities in Membrane Mimetic Systems ’, ‘ Solar-energy Conversion in Membrane Mimetic Systems ’ and ‘ Miscellaneous Applications’. The catalytic properties of membrane mimetic agents originate from their abilities to organise, concentrate or separate reactants and to provide favourable microenvironments in which the reactions may take place, e.g. by alteration of local pH, viscosity or dielectric properties. By suitable choice of the catalytic system, selectivity and stereochemistry may also be controlled in some cases. Amongst the subjects discussed are the kinetics and energetics of enzyme-catalysed reactions and their relationship to reactions catalysed by membrane mimetic agents, the alteration of reaction paths and stereochemistry, isotope enrichment and phase-transfer catalysis.Considerable use is made of tables to collect together relevant information: in fact chapter 12 contains no less than 128 pages of tabulated data. Although this should make information retrieval relatively easy, the tables are sometimes difficult to follow because of the large amount of data compressed into a small space. There are also some minor printing errors and a few improbable chemical structures which have escaped the proof-readers, eyes. These small criticisms apart, Prof. Fendler is to be congratulated for his thoroughness in gathering together such a wealth of information in a single volume and for presenting it with such clarity.The book is addressed to a wide readership: ‘synthetic, physical, colloid, polymer and biological chemists as well as physicists, biophysicists and engineers’. Unfortunately its price will put it beyond the reach of most individuals, but Membrane Mimetic Chemistry will certainly take its place among the standard reference works in academic and industrial research libraries and must be regarded as essential reading for those with an active interest in the field. I. G. LYLE Received 15th August, 1983 McGraw-Hill Encyclopedia of Chemistry. Ed. by S. P. PARKER. (McGraw-Hill, New York, The material appearing in this volume has been published previously in the McGraw-Hill Encyclopedia of Science and Technology, 5th edn, 1982.The 790 articles, arranged alphabetically, have been selected by a group of consultants and editorial staff and contributed by nearly 200 authors, both academic and professional scientists (including about half a dozen from the U.K.!). The length of these articles varies from 10 lines to 7 A4 pages, given a total of ca. 1200 pages. The price of iE40.95 represents a cost of 39 p per page, so apart from Faraday Transactions this must be one of the cheapest publications of its day, particularly since it includes 800 1983). Pp. viii + 1195. Price E40.95.REVIEWS OF BOOKS 1659 illustrations, comprising graphs, tables, structural formulae and photographs. The volume has been produced to the very high standard that one normally gets from this publisher, helped by some excellent editorial work.The scope has been restricted to analytical, inorganic, organic and physical chemistry and chemical physics, although there are references to biochemistry and chemical technology in various articles. Thus ‘ Adsorption ’ mentions its use in wine purification, colour removal from sugar, waste water treatment, gas masks and the use of surface-active agents in detergents, lubricants and photography etc. Usually each article cites in the appended bibliography some books for further study. Naturally there is personal bias; indeed, one can sometimes recognise the book from which the material has been reproduced; and in other cases one can criticise the selection; for example, one book on thermodynamics was adversely reviewed by the present reviewer when it was first published.Other books were written some 20 or more years ago, and except for some slight historical interest, do not correctly reflect the present assessment of the topic. Nevertheless, most bibliographies have been well chosen and provide good accounts of theory and experimental techniques of the developments that have taken place in the last few years. Cross-references to related articles are a useful inclusion, but can be a source of irritation in a few instances because they are either repetitive in content or provide a mass of material very remotely related to the original article. The index, comprising 5000 entries, is well constructed; the main title of an article is asterisked to distinguish it from the subtitles in that article.No difficulty was found in locating information in analytical, organic and inorganic chemistry, but in physical chemistry some of the main titles were deceptive. Thus photolysis (p. 768) is solely concerned with silver halides and the Mott-Gurney theory of the photographic process. There are no cross-references; one of the books recommended for further information was published in 1955 and, in a modern context, contains little of relevance to the subject. The term ‘work function’ (related to ionisation energy) is an important quantity in the experimental and theoretical study of the structure of chemisorbed molecules. However, the information provided is that it is synonymous with the Helmholtz free energy and that European schools merely use the term ‘free energy’.Certainly in the U.K. one does not associate the work function with free energy, and furthermore one does distinguish Gibbs and Helmholtz free energies. The preface states that the encyclopedia is ‘an indispensable reference for laymen (as well as students, librarians and professionals) who need basic information in a readily acceptable format’. It seemed that the material under the main title, ‘Gas’ might ascribe to this claim. The ideal gas, empirical equations of states, and corresponding states were described but the laws of Avogadro, Boyle and Dalton were not mentioned; these appeared separately under the main titles. However, the article dealing with the theoretical aspects of the subject may be expected to present difficulties since it involved statistical mechanics and therefore partition functions.A search for an explanation of these two quantities was unsuccessful; a few lines about the general nature of the first and no definition of the second were the only outcome. Similarly, the term ‘laser’ is a reasonably familiar one to the average layman; despite an excellent article on laser photochemistry and spectroscopy, the meaning of the acronym and the basis of production of a laser beam could not be found. All the above criticisms are minor; nevertheless, the omission of an article on SI units was unexpected. Although these have now been almost universally adopted, a title Conversion of Units would have been welcomed, particularly since some books recommended in the bibliographies were of a vintage nature employing the older units.A table of conversions (particularly of electromagnetic units) would have been an asset. Encyclopedic volumes devoted to organic and inorganic chemistry can usually be found on the library shelves of university departments; this may militate against the purchase of the present volume, but from the viewpoint of a physical chemist, it would be a very valuable addition. The scope is extremely wide, and sophisticated theoretical concepts are presented with clarity and depth. Articles on chemical dynamics, spectroscopy and structure, molecular-orbital and valence-bond theory, crystal-field theory, nuclear chemistry (including fission and fusion) and X-ray crystallography, to mention only a few articles, are of outstanding merit.After purchase of this volume, the librarian should ensure that it occupies a central position in the library stacks to counteract the physical effort of removing it; it weighs 3 kg! F. C. TOMPKINS Received 26th September, 19831660 REVIEWS OF BOOKS Molten Salt Technology. Ed. by D. G. LOVERING. (Plenum Press, New York, 1982). Pp. xv + 533. Price E50. The editor of this volume is to be congratulated for bringing together such a wide and relevant range of reviews of the technologies based on molten salts. The book, which will probably be used as a reference work rather than a textbook, consists of fifteen chapters including an introduction by the editor and chapters on aluminium extraction, the alkali metals, other elements, two-phase partitioning, the treatment of metals, ionic carbides, fluxes, glasses, corrosion, batteries, fuel cells, industrial organic and fuel chemistry, thermal-energy storage and nuclear- and solar-energy production. The chapters on batteries by Cairns and fuel cells by Selman and Marianowski are particularly authoritative while the most fascinating, in the reviewer’s opinion, is that by Hatt on organic and fuel chemistry, which highlights what are perhaps, at first sight, unusual applications of high-temperature liquids. The chapter by Marcus on thermal-energy storage is a typically thorough account. Some topics such as glasses and fluxes are not usually included under the molten salts umbrella, but their inclusion here is valuable none the less.Some of the other chapters are the expected ones on such subjects as aluminium extraction and the alkali metals and these are open to criticism in detail. For example, although one can admire the authority of some of the authors vis-u-vis the technology, their presentation of the fundamentals leaves something to be desired. Also references to some early seminal reviews on corrosion in molten salts are omitted. Nevertheless, the book will make a welcome addition to the shelves of those interested in these fascinating high-temperature liquids. D. INMAN Received 28th September, 1983 Progress in Solid State Chemistry, Volume 13. Ed. by G. M. ROSENBLATT and W. C. WORRELL. This volume contains six review articles by eminent scientists and the high standard of content and presentation that has become characteristic of the series is maintained.Three contributions are of approximately the same length (ca. 30-40 pages); by Riekel (Kinetic studies of chemical reactions : inferences from structural and related observations on intercalation compounds), Schmalzried (Ag2S: the physical chemistry of an inorganic material) and Roth (Thermal stability of long-range order in oxides). Those by Ponte Gonqalves (Spectroscopic investigations of intermolecular interactions in organic molecular crystals), Oates and Flanagan (The solubility of hydrogen in transition metals and their alloys) and Winograd (Characterization of solids and surfaces using ion beams and mass spectrometry) extend to ca. 80 pages and are real tours de force in their respective areas.Ponte Goncalves’ article discusses spectroscopic evidence for the nature of intermolecular interactions in organic molecular crystals. The information is drawn from infrared absorption, Raman scattering, inelzstic neutron scattering, n.m.r., nuclear quadrupole resonance, electron paramagnetic resonance, u.v.-visible absorption, fluorescence and phosphorescence. The extent of agreement between theoretical formulations and experimental measurements is shown to be improving. Riekel’s article concentrates on the use of kinetic neutron powder diffractometry to yield experimental data on intercalation reactions and compares the results with those of X-ray diffraction and high-resolution transmission electron microscopy (HRTEM) on similar systems.Particular attention is given to the intercalation of the layered chalcogenide, 2H-TaS2, upon addition of molecules such as ND,, C,D,N and D20. The various intermediate-stage products are identified and characterised. The extreme utility and versatility of neutron diffraction in solid-state studies is well brought out in this impressive article. Schmalzried’s contribution discusses almost completely the entire physical chemistry, viz. structure, thermodynamics, electrochemistry, defect structure, phase transitions and reactivity, of one material, Ag,S, which ‘in 1933 threw doubts on the validity of Faraday’s law’ and (Pergamon Press, Oxford, 1982). Pp. v+386. Price $1 12.REVIEWS OF BOOKS 1661 subsequently gave rise to solid-state electrochemistry through Carl Wagner’s contributions.(See volumes 6 and 7.) The present article is compulsory reading for anyone interested in solid-state science. Roth’s article attempts to answer fundamental but rather specialized questions in the field of non-stoichiometric oxides. At the conclusion of the article there are as many unanswered questions as there were at the start, but the treatment of the relationship between thermal annealing and the long-range order of ‘block’ and ‘infinitely adaptive’ structures is interesting reading for the specialist. Oates and Flanagan’s contribution is important in view of recent interest in hydride systems from the point of view of energy storage and superconductivity. The thermodynamic treatment here is very rigorous and this may deter the generalist from reading further than the first few Winograd’s article is arguably the most readable in the present volume and should be of general interest even to the chemistry or physics graduate student, who should be able to identify with most of the concepts introduced.The analogy between an ion striking a crystalline surface and a snooker player’s ball striking the initially perfect triangular array of 15 red spheres is strikingly pictorial and typifies the tone of the entire article. The scientific treatment is nevertheless extremely rigorous and the clarity of presentation unquestioned. The volume reproduces authors’ typescripts in their original forms but this does not distract the reader from enjoying the wealth of information available in its 386 pages.It should be essential reading for those of higher than graduate status with any interest in solid-state chemistry. It will probably not find its way into personal collections but deserves to be in every scientific library. J. 0. WILLIAMS pages- Received 7th September, 1983 Flash Photolysis and Pulse Radiolysis. By R. V. BENSASSEN, E. J. LAND and T. G. TRUSCOTT. (Pergamon Press, Oxford, 1983). Pp. 236. Price E9.95, $19.95. Few would argue that the development of the techniques of flash photolysis and pulse radiolysis for the monitoring of concentrations of transient species and the kinetics of their decay caused a major advance in the understanding of the excited-state chemistry of molecules in a variety of environments. The application of these techniques to biological systems has also improved the understanding of several phenomena in which molecular excited states play a role in biology and medicine. The authors of this volume are all pioneers of the use of these techniques in such systems and the book thus has an authoritative air.There is an introductory chapter describing the techniques and some basic photochemistry. The second chapter is concerned with tetrapyrrolic pigments and touches upon such diverse biological phenomena as photosynthesis, haem biosynthesis, bile pigments and bilirubin isomerization phototherapy, haemoglobin and myoglobin and respiration. A full description of polyene chromophores is given in chapter 3, along with discussion of, for example, the role of carotenoids in biological systems and preliminary discussion of vision.This is amplified in a later complete chapter on vision, as is the discussion on photosynthesis, to which a complete chapter is also devoted. There are further chapters on proteins and components, nucleic acids, and components, electron transport chain components and, finally, an interesting discussion on drugs, such as radiosensitizers, photosensitizers, including psoralens, and phenothiazines. A comprehensive bibliography is provided. Many of the studies described here are results of nanosecond and microsecond experiments, although there are some references to faster picosecond phenomena where relevant. A criticism of the book would be that by concentrating attention upon techniques for measuring fast transient phenomena at the expense of steady-state experiments the authors may have produced a somewhat unbalanced volume.However, it certainly contains much of interest to those involved in effects of radiation, both ionizing and u.v.-visible, upon biological systems, and will be most useful as a supplement to other material rather than standing on its own. The1662 REVIEWS OF BOOKS book is moderately priced and has been produced attractively. It will surely find a market amongst those of diverse backgrounds who have an interest in excited states in biological systems. D. PHILLIPS Received 17th August, 1983 Advances in Chemistry Series, No. 1%. Catalytic Aspects of Metal Phosphine Complexes. Ed. by E. C. ALYEA and D. W. MEEK. (American Chemical Society, Washington D.C., 1983).Pp. x+421. Price $67. This book comprises 24 articles of equal length, drawn from the lectures given at a symposium in June 1980. It covers some of the areas occupying the attention of those interested in metal-phosphine complexes at that time. However, the title is a little misleading because over half of the articles have but a fleeting relationship (if any) to catalysis. Very few metals make an appearance to any major degree. In the chapters which do deal with catalysis, the main concentration is on complexes of rhodium, followed by palladium. Other articles which present new (or not so new) results and discussion of the chemistry and spectroscopic properties of metal-phosphine complexes also concentrate on these or the other members of the platinum- group metals.A high proportion of the discussion makes use of n.m.r. (especially 31P) and the results of crystal-structure determinations. The style adopted in the reports is very variable. Contents range from reviews of a limited field to highly specific papers on a singular topic (complete with Experimental section). The latter are of a form more appropriate to a primary journal. All the articles carry abstracts, which is just as well since many of the titles are far more general than what follows. As far as possible, papers on related topics have been grouped together. Four chapters (chapter number in parentheses) are specifically devoted to aspects of n.m.r. : (1) discussion of lJ(Pt-P) coupling constants and their correlations with bond lengths and with other coupling constants, (2) the value of the multinuclear approach in exploring the chemistry of Pt-Sn systems, (3) the use of 31P n.m.r.in studying reaction processes of rhodium hydroformylation catalysts and (24) comparison of slP spectra of solids and solutions for some diphosphine ligands and their rhodium complexes. The trend towards modifying phosphine ligands and exploring the complexes they form is well represented. The types covered include : (9) tricyclohexylphosphine, ( 6 ) biphosphines which give complexes containing large chelate rings, (1 6) phosphines with long alkyl chains and (1 8) chelating iminophosphines. Chapter (19), on the synthesis of polyphosphines, includes examples with asymmetric centres, with additional groups which are potentially donors and with P-H bonds.The articles directly concerned with catalysis mostly concentrate on particular systems and discuss possible mechanisms. The topics include : (4) catalytic decarbonylation of aldehydes using cationic Rh catalysts, (1 2) a review of the addition of vinylic groups to olefinic compounds with triarylphosphine complexes of palladium(r1) acetate, (1 5) rapid hydrogenation of olefins with a tritertiaryphosphine rhodium(1) chloride complex activated by ethylaluminium com- pounds and (17) a variety of oxidation reactions catalysed by rhodium and rhenium carbonyls. Four papers are devoted to asymmetric synthesis. One (21) assesses cationic rhodium complexes of four different chiral bidentate phosphines as catalysts for hydrogenation of N-acylaminoacrylic acids and it is followed (22) by a critical discussion of enamide hydrogenation with rhodium complexes of chelating phosphines.Hydrocarboxylation of olefins using palla- dium phosphine catalysts is assessed (23), as is a set of chiral biphosphines on rhodium for asymmetric hydrogenation and hydroformylation (20). There is an interesting presentation (8) on the oxidative addition of water to platinum(o) and rhodium(1) complexes, and the catalytic role of the products in the hydration of nitriles, activated olefins and in H/D exchange reactions. Two chapters describe the chemistry of dimeric (1 3) platinum(1) and (1 4) palladium(1) complexes of bis(dipheny1phosphino)methane ; another ( I 1) describes oxidative addition ofREVIEWS OF BOOKS 1663 acylchlorides to rhodium(1) and iridium@) systems, isomerisation of secondary alkyl groups on iridium centres and the formation of monomeric hydride, hydroxide and methoxide complexes of platinum.There is a rather specific paper (7) on a dimeric hydride complex of rhodium, which is rationalised as a RhI-Rh’I’ mixed-valence compound. The first transition series is represented by some iron examples in a description of the formation, structure and chemistry of some clusters with diphenylphosphido-bridges (1 0), although the main emphasis is on ruthenium. Cobalt has a place to itself ( 5 ) in a report on cobaloxime complexes with phosphine ligands; there are nine correlative plots (some of which resemble the sky at night) but they have nothing to do with catalysis.Such compilations from conferences are apt to be patchy in quality and interest, and I foresee few of these articles becoming standard references for long. The two years which have passed between submission and publication diminish the value of t h s book as an up-to-date source of information. The libraries of institutions active in the fields of homogeneous catalysis and the platinum group metals will probably want to purchase it, but I doubt whether many individuals will think it worth its price. P. L. GOGCIN Received 19th September, 1983 Polymers: Properties and Applications, Volume 6. Polymer Melt Rheology and Flow Birefringence. By H. JANESCHITZ-KRIEGL. (Springer-Verlag, Berlin, 1983). Pp. xv + 524. Price DM98, $39.20. This book is a most welcome addition to the polymer literature.All too many recent polymer texts have been little more than reworked versions of earlier texts: this one is most certainly not. While some parts of the book will be familiar to those acquainted with Janeschitz-Kriegl’s own significant original contributions to the polymer literature, only at one point (in section 2 of chapter 4) is there any obvious similarity between the author’s original paper and the book. The rest of the material in the book is quite new. The book comprises four chapters and three substantial appendices. Chapter 1 is introductory in nature. In section 1, the reader is presented with a brief but clear account of the fundamen- tals of the theory and practice of rheometry, i.e. of the measurement of such rheological properties as shear and extensional viscosities and moduli.In section 2, Janeschtz-Kriegl gives an admirably clear account of the measurement of birefringence, i.e. of the measurement of optical anisotropy which is characterised by a difference An in refractive index. The reason for measuring An is that use of a so-called ‘stress-optical la*’ enables the associated difference As in stress to be calculated. Indeed, for As < ca. los N m-2, the ‘stress-optical law’ is approximately linear for most polymers: An = CAs, where C is the ‘stress-optical coefficient’. Thus optical methods can be used to determine otherwise inaccessible mechanical properties. ’ Chapter 2, which comprises about a third of the book, is an up-to-date account of rheological constitutive equations based on quasi-molecular (or kinetic-theory type) models.The chapter amply demonstrates the author’s command of the subject and would repay serious study by any specialist in the subject. Chapter 3 is in many ways a continuation of chapter 2. In it, some of the ideas presented in the earlier chapter are followed up to the extent that predictions can be made about, for example, the variation of shear viscosity with shear rate. Chapter 4 comprises discussions of two industrial applications of the rheometry/birefrin- gence ideas developed earlier in the book. In section 1, the topic is molecular orientation, which is of importance in fibre spinning and film blowing. In section 2, Janeschitz-Kriegl discusses birefringence in injection moulding. Incidentally, this section contains one of the few misprints in the book that might confuse the reader: equation (4.2.12) on page 438 should read: l/r// = @+ 1.The three appendices cover linear viscoelasticity theory, the time-temperature superposition principle and the measurement of birefringence. All three are concisely but clearly presented. This book should be on the shelves of all polymer rheologists. It is well written throughout : the occasional lapses in style (which of course arise because the author’s native language is not English) never lead to ambiguity or misunderstanding. Although the book is produced by1664 REVIEWS OF BOOKS photographic reproduction of the original typescript, this has been done sufficiently well not to be irritating. S. M. RICHARDSON Received 22nd August, 1983 The Foundations of Chemical Kinetics.By S. W. BENSON. (Krieger, Malabar, Florida, 1982). Pp. xvii + 723. Price $39.50. This volume is a ‘corrected and updated’ edition of the original first published in 1960. Large sections, such as those on heterogeneous reactions and reactions in solution, appear to be completely unchanged, and for other sections the corrections are few and updating is negligble. What minor changes there are are themselves sometimes sources of new error and often have been incorporated in the text rather clumsily. Such changes have done little to enhance the original. The only substantial and worthwhile addition is the expansion of the tables of thermodynamic properites in the Appendices. There are also some welcome additions to the Problems.When this book was published in 1960 I admired it greatly for its detail, breadth and the original insights which the author brought to many aspects of the subject, often reflecting his own notable contributions. Not all were as enthusiastic (see Trans. Faraduy Soc., 1962,58, 1272) but generally it was well received. What is its present status? Since 1960 the field of chemical kinetics has changed not only in detail but also in emphasis. In gas-phase kinetics interest now centres on elementary processes studied often at the quantum level and even the handling of phenomenological systems, so strongly emphasized in this book, has been transformed by the proliferation and power of modern computers. Consequently, the book no longer reflects current preoccupations in kinetics and a number of sections have dated badly, particularly those on experimental techniques. On the other hand there is also much of it that remains as relevant now as it was in 1960 and, on balance, enough to justify the reissue of this volume, but only just.The book was never particularly suitable as an undergraduate text but there are still parts of it that make rewarding reading for the serious student of chemical kinetics, and research workers would wish to find it on their library shelves, if not their own. At the price it is still worthy of purchase by libraries which do not have a copy of the earlier edition. D. L. BAULCH Received 23rd August, 1983 Iron Porphyrins, Parts 1 and 2. Ed. by A. B. P. LEVER and H. B. GRAY.(Addison-Wesley, Bioinorganic chemistry is the study of metal ions and complexes in living systems and it is a rapidly expanding subject. It involves a wide variety of disciplines, but redox chemistry occupies the central role and provides the essential framework of the subject. To this end, it is encouraging to note that this series has as its main theme: ‘What can we learn about the geometric structure, the electronic structure and the mechanism of biological redox centres through the study and use of modern physical techniques?’ The study of iron porphyrins in artificial and natural environments offers some hope towards answering this important question. The first two parts are devoted to understanding the electronic and geometric structures of iron porphyrins.These are important compounds in living systems and they provide a great opportunity to apply theoretical and instrumental expertise to unravelling their complex structure and functions. Part 1 begins with theoretical aspects of iron porphyrins and considers the application of m.0. theory to hemes and related materials. The importance of ligand effects, spin states and stereochemical effects in the chemistry of hemes is discussed. The absorption spectra of hemeproteins in single crystals are described in detail whilst the n.m.r. of iron porphyrins is given adequate coverage. London, 1983). Pp. xiv+286 and xiv+254. Price E29.20 and E28.45.REVIEWS OF BOOKS 1665 Part 2 is concerned with e.p.r. and resonance Raman spectroscopy of metalloporphyrins and hemeproteins.These chapters are authoritative and detailed and they encompass an enormous amount of background material. The final chapter presents an excellent account of the electrochemistry of iron porphyrins in non-aqueous solution. Without doubt, this is the highlight of the series so far. Successive volumes are planned, but already the tone has been set and later articles will have to live up to the high standards portrayed here. The books are well presented and not too long. A wealth of reference material can be found between the covers of each part and the organisation has been sufficiently good to make it easy to locate. The books are really aimed at the specialist, but serious students of bioinorganic chemistry should find them highly valuable in learning the subject.My only criticism concerns the wholly inadequate index. A. HARRIMAN Received 3 1st August, 1983 Basic Physical Chemistry. By W. J. MOORE. (Prentice-Hall International, London, 1983). Pp. xx+711. Price E10.95. Gilbert Castellan’s textbook on physical chemistry opens with a Foreword to the Student which begins, ‘On most campuses the course in physical chemistry has a reputation for difficulty.’ There follow words of advice which seem to me to be sound and practical. For example, he advocates the use of paper and pencil in the study of physical chemistry and he does not once refer to ‘Study Skills’. I have drawn the attention of my colleagues to this Foreword and we commend it to students. We have not done a properly controlled experiment so I cannot judge the extent to which the advice is heeded.However, I can state with absolute certainty that we do not have one hundred per cent success. A significant number of students remain non-ideal; they do not address themselves to the study of physical chemistry with all the enthusiasm that we would wish. Thus, like some alchemist, I approach every new textbook with the hope that it will be the Philosopher’s Stone which will transmute dullards and good-for-nothings into scholars. Lest this approach seem too despairing, or even cynical, I hasten to add that I do have at least two other major concerns when inspecting new texts. First, I hope for enlightenment, ‘Of course! That’s the way it must be. I’ve never really understood that before. ’ Secondly, I hope for fresh insight, ‘That’s interesting! I’ve never really thought about it in that way before.’ Thus it is that there is no shortage of opportunities for writers of textbooks to please me. Despite all the hullaballoo about new blood there are almost no truly young people teachmg physical chemistry in British universities, so it is safe to assume that we are all familiar with Walter Moore’s earlier book, Physical Chemistry. That ran to five editions, and a strong case can be made for conferring upon it the status of a classic. We therefore take particular interest in a new book, Basic Physical Chemistry, from the same pen. From the outlook implicit in my opening paragraph the Preface is encouraging : ‘According to my experience, students follow thermodynamics more easily if they understand what is happening at the molecular level.’ Hope springs eternal and we press on. True enough the first five chapters are about molecules, at least they are after dimensions and definitions have been disposed of, and to be fair I think these could be usefully read by anyone studying physical chemistry. Then comes the thermodynamics, starting with The Concept of Work (!). And we find Reversible Processes and State Functions and Thermochemistry and Entropy and Heat Engines and Interpretation of the Gibbs Function and so on. This is all very well, but will a significant number of students follow it more easily because they’ve read five chapters on molecules? According to my experience, they will not. Feeling slightly disappointed I turn to compare this book with the fifth edition of Physical Chemistry.Now I discover what it might have been useful to know at the beginning: this is virtually a sixth edition. I have been rather slow on the uptake for I had a suspicion that a lot of those diagrams looked familiar. Detailed comparison confirms the diagnosis. There is some reordering and regrouping of material, some things are omitted, some topics treated more briefly and superficially, and there is a small amount of new material. The greatest novelty lies in the problems at the end of each chapter, for very many of these are different and I welcome1666 REVIEWS OF BOOKS them unreservedly for they will provide fresh inspiration and material for tutorial and examination questions. So I am, frankly, disappointed.I hoped for something new and did not find it. It seems to me that if you liked ‘Moore’ you will like this: if you did not, you will not. That is really all there is to say except for one last thought. I wonder why Professor Moore did it? He has a great knowledge and love of physical chemistry and he could rest upon his laurels of a highly successful text. So why didn’t he cut loose and be bold? Why did he not attempt a non-standard work like, for example, ‘The Structure of Physical Chemistry’? It would have done nothing for the non-ideal students, who would have reacted like football hooligans faced with Jane Austen, but it might have done something for the good students. And it would have cheered me. N. M. ATHERTON Received 6th October, 1983 Atomistics of Fracture.Ed. by R. M. LATANISION and J. R. PICKENS (Plenum Press, New York, 1983). Pp. xv+ 1074. Price $1 15. This massive volume of over 1000 pages records the proceedings of a conference held in May 1981, in the beautiful surroundings of Calcatoggio, Corsica. It was attended by 64 delegates from 13 nations. The purpose of the conference is very well summarised on the dust cover and refers to the fact that although a large amount of information is available on the materials and mechanics of fracture on a macroscopic scale comparatively little is known of the atomistics of fracture. Even less is known about the atomic-scale processes involved in environmentally induced fracture or embrittlement. ‘It seems clear that future research will have to be based on a fuller appreciation of the chemistry and physics of the pertinent surface processes in addition to the more traditional studies of mechanical and metallurgical factors.Such an effort will depend upon the cooperation of scientists from an unusually broad range of scientific disciplines. ’ ‘The present volume is a pioneering work that gathers together the knowledge and expertise of scientists in materials science, mechanics, physical chemistry, surface chemistry, surface phys- ics and mathematical modelling on the subject of the atomistics of fracture. The contributors, leading international researchers, offer a state-of-the-art treatment of this subject, unique in its wide-ranging approach. Specific topic areas explored include the fracture of materials, surface reactivity and bonding, interfaces, solution chemistry, new concepts in atomistics of fracture, hydrogen embrittlement, intergranular embrittlement, liquid-metal embrittlement and stress- corrosion cracking.’ How far do these proceedings fulfil the ambitious aims of the conference organisers? The planning is very professional. There are three very readable and informative introductory papers. These are followed by a sequence of tutorial lectures (700 pp.) and a series of business-like workshop sessions (300 pp). The volume includes a list of participants, a group photograph and a very useful subject index. There is little doubt that the main papers are authoritative and up-to-date and occasionally quite exciting. Some are rather specialised but show a measure of consideration for those conference delegates belonging to other disciplines.Others resemble lectures presented to a conference of specialists in their own fields. The solid-state physicists, for example, even disagree amongst themselves (clusters versus surface density functions ; covalent bondings versus dipole bonding). On the whole the chemists do rather better both in coverage and in presentation. I am particularly impressed by G. M. Whiteside’s contribution on fracture and coordination chemistry and entertained by J. 0. M. Bockris’s rather sharp comment that if ‘we had to compute the rate-determining step without the aid of experiment we should be no better off than the physicists!’. There is also a most informative paper by B. E. Conway on the solid4ectrolyte interface and a workman-like analysis by M.Pourbaix of corrosion growth in a crack, especially in the presence of chlorine ions. On the whole, metals which are resistant to corrosion are often the ones most fracture-sensitive to the same environment. Apart from the value of the papers themselves the overall assessment turns on the extent to which, as a result of the conference, we now have a better understanding of fracture in atomistic terms. There are many difficulties and gaps. For example N. H. Macmillan’s masterly reviewREVIEWS OF BOOKS 1667 of the ideal strength of solids concludes with the remark that his treatment assumes homogeneous deformation and is therefore not directly applicable to the situation at the tip of a crack. Similarly, from a brilliant self-critical paper by G.J. Diens and A. Paskin on the computer modelling of cracks in terms of interatomic forces it would appear that their results, although tantalisingly promising, contain some problematic features. Even if these uncertainties were lacking their most detailed model is for a Lennard-Jones interatomic potential, so that in effect they are studying a material resembling solid argon. Again in the discussion of hydrogen embrittlement, which covers a major part of the deliberations, it seems that there are at least five different mechanisms: and it is not clear if they are mutually exclusive or if there are synergistic interactions between one mechanism and another. There are also some omissions. In particular I missed an authoritative paper (such as might once have been given by Conyers Herring) on fundamental concepts of surface energy particularly in relation to solids: this theme is hinted at in various papers but never exposed and discussed.And for fracture people who work on polymers or ceramics it would have been a kindness to have made the title more explicit: ‘Atomistics of Fracture of Metals’. In h s final summary Prof. A. S . Argon shows a global appreciation of the problems of fracture, although there is a curious lack of impact of the conference itself on his overall presentation. Perhaps this reflects the rather intangible nature of many of the contributions. Of one he writes that it gives a rich picture and useful information but falls short of providing definitive understanding. This is probably the clearest impression of the conference as a whole.The gap between atomistic models and the real world of fracture has not yet been bridged, and one of the most valuable aspects of the conference proceedings is the extent to which it outlines the nature of the challenges involved. As such the volume is a valuable compendium, full of unsolved problems, a source of first-rate information and a stimulus for those working in the field of metallic fracture. What one misses, of course, in spite of the printed discussions, is the general atmosphere and the personal interactions that must have developed between those who were fortunate enough to attend the conference. D. TABOR Received 22nd September, 1983 Proceedings of the Fifth Tihany Conference on Radiation Chemistry. Ed.by J. DoB~, P. HEDING and R. SCHILLER. (AkadCmiai Kihdo, Budapest, 1983). Pp. xix+ 1142. Price $75. The book, which is in two volumes, presents in photo-ready form the opening address and the 145 papers and discussion which formed the substance of the Fifth Tihany Conference on Radiation Chemistry, which was held in September 1982 at Siofok on Lake Balaton. The preceedings of all the conferences in this series, the first of which was held at Tihany in 1962, have been published in book form and consequently provide a record of the changes in radiation chemistry over this period. Although the proceedings are entirely in English, the meetings have proved to be truly international, with participants drawn from many countries, but as would be expected for a conference which is based in Hungary there have always been substantial contingents from Eastern Europe and the Soviet Union, and this is reflected in the character of the conferences and the published volumes.Contemporary radiation chemistry embraces not only the elucidation of the detailed chemical processes which follow the absorption of ionizing radiation by chemical systems, but has increasingly become a tool for studying chemistry involving reactive species, a great variety of which may be generated in highly specific and controlled ways by the use of radiation. The technique of pulse radiolysis, which is routinely used with nanosecond time resolution, has played a very important role in these developments. For example, in aqueous solution one can readily generate and study the redox and acid-base properties of a wide range of organic radicals formed by reaction of the primary radiolytic species with suitable solutes.Equally, in organic solvents one can study the chemistry of radical anions, radical cations and excited states. In addition, radiation chemists have always shown keen interest in the elucidation of the chemical basis of the processes by which radiation damages living systems and are increasingly investigating the redox processes which occur in normal tissues. There is also considerable interest in the application of radiation for industrial and technological purposes.1668 REVIEWS OF BOOKS This wide range of interests is reflected in the papers presented at the conference. The two volumes are divided into five parts: General Problems (22 papers), Aqueous and Inorganic (31 papers), Organic Materials (36 papers), Polymers (40 papers) and Biological Problems (1 6 papers).Although the wide range of topics covered demonstrates the vitality of the subject, it clearly presented a problem to the conference organisers and editors to subdivide the papers into suitable groupings. Unfortunately the classifications chosen have led to an excessive diversity of topics within each section and have failed to impart an overall sense of coherence to the subject. The 22 papers under the heading General Problems might, more appropriately, have been classified as miscellaneous since they embrace a wide range of topics, including the early physico-chemical stage following the absorption of radiation, theoretical and experimental studies of the absorption spectrum and physical properties of solvated electrons, miscellaneous radiation-chemical studies, contributions on general kinetics and physical chemistry and on muonium and positronium chemistry.The sections on Aqueous and Inorganic Systems and Organic Materials amply exemplify the range of interests embraced by radiation chemists. The very substantial number of papers dealing with Polymers indicates the continuing and increasing interest in this subject, which is thought to have potential for industrial and technological application to the synthesis of polymers and graft polymers and the modification of polymers by irradiation to give physical properties which make them suitable for specific applications, such as insulating materials for use at high temperatures and heat-shrinkable polythene. A number of papers deal with the interesting possibilities of using radiation to produce intimate composites of plastics and traditional materials, e.g.wood or wood fibres. Perhaps the section which least reflects the intensity of current interest is that dealing with Biological Problems. Somewhat surprisingly no paper was presented pertaining to the sensitization of hypoxic cells to radiation or the related problem of the protection of organisms from radiation. Equally, there was only one paper on the use of radiation-chemical methods to study biochemical electron-transport processes, although a second paper on a related topic was assigned to the Aqueous and Inorganic Systems section.Generally, the photo-ready production resulted in a very acceptable product, and the fact that publication was achieved within a year of the conference is highly commendable and fully justifies the use of this method. In spite of the wide range of nationalities of the contributors and the fact that the native language of the editors is not English, the papers are generally well written and remarkably free of errors. At $75.00 this is undoubtedly a more expensive means of publishing papers than through the standard scientific journals, but notwithstanding this I feel this publication is good value for money and, although it is unlikely to be bought by many individuals, it should appear on the shelves of well-appointed libraries.G. A. SALMON Received 3rd January, 1984 Crystals: Growth, Properties and Applications, Volume 9. Modern Theory of Crystals. Ed. by A. A. CI-ERNOV and H. MULLER-KRUMBHAAR. (Springer-Verlag, Berlin, 1983). Pp. 146. Price DM 88, $38. This volume presents a very interesting collection of reviews covering some of the most fundamental problems which form the foundation of any real understanding of crystal growth. The first two of the five chapters are broadly concerned with melting and solidification but in very different ways. A. Bonissent writes on the ‘Structure of the Solid/Liquid Interface’ and is thus concerned, ultimately, with conventional crystal growth from the melt. Specifically, however, the chapter is concerned with looking at different ways of modelling the interface itself, in equilibrium and not during growth, to try to establish the nature of the interface; is it sharp or diffuse, how does one understand poor wetting in some systems, can one calculate interfacial free energies? In the second chapter, ‘Melting and Solidification of Epitaxial Structures and Intergrowth Compounds’, P.Bak looks at the problem of understanding the melting transition itself, but on ‘simple’ model systems rather than conventional bulk material. Thus two- dimensional model systems such as weakly adsorbed adsorption monolayers (both commen-REVIEWS OF BOOKS 1669 surate and incommensurate with the substrate) are investigated, along with surface reconstruction transitions of the top layer(s) of some metal surfaces. Some three-dimensional systems are also considered, although these are quasi-two-dimensional (graphite intercalation compounds) or quasi-one-dimensional (mercury chain compounds).A unifying theme of these two chapters is that they are concerned with disordering of a phase in contact with an ordered solid phase. W. Haubenreisser and H. Pfeiffer, writing on the ‘Microscopic Theory of the Growth of Two-component Crystals ’ address the problem of modelling the kinetic process of crystal growth itself, but necessarily using a much cruder model of the solid/liquid interface, namely a lattice model. Despite the obvious physical inadequacies of such a model, it remains the most powerful approach to the kinetic theory of solidification available, and the authors investigate its application to binary crystal growth using a number of different statistical approximations.By contrast to the microscopic approach used in the first three chapters, V. V. Voronkov writes on the ‘Statistics of Surfaces, Steps and Two-dimensional Nuclei : A Macroscopic Approach’. Here no use is made of the idea of growth units (atoms) being transferred from the liquid to the solid phase. Instead, the growth processes on singular and vicinal surfaces are described in terms of step motion tangential to the surface, while the properties of these different surfaces themselves are expressed through their interfacial free energies. Finally, J. P. van der Eerden presents an article on ‘Surface and Volume Diffusion Controlling Step Movement ’, which contains both microscopic and macroscopic features.Thus it is primarily concerned with the transport of growth units to the interface, but t h s is deemed to occur across some boundary layer, and the local structure of steps (kinks) is not taken into account explicitly. However, the way in which surface diffusion is interrelated to step interactions is discussed. In summary, the collecting together of these contrasting views of some of the underlying physical problems of understanding crystal growth is very worthwhile, and it will be interesting to see how the theme is developed in a second volume which is apparently planned by the editors. D. P. WOODRUFF Received 4th November, 1983 Gas Transport in Porous Media: The Dusty-gas Model. By E. A. MASON and A. P. MALINAUSKAS. (Elsevier, Amsterdam, 1983). Pp.viii+ 194. Price Dfl 125, $53.25. The transport of material through porous media is a process of considerable engineering importance in fields as diverse as membrane separation technology and heterogeneous catalysis. However, there remains a disparity between the understanding of the fundamentals of the transport process and the routine application of these fundamentals to engineering problems. This book sets out to bridge this gap by bringing to the attention of chemical engineers a simple, unifying model which allows a wide variety of transport processes to be treated in a consistent manner. The dusty-gas model, in which the particles of the porous medium are treated as one large and massive component of a gas mixture, has a long history which is briefly reviewed in the text.However, for the simple reason that the development of the theory for the model has been published in the scientific, rather than the engineering, literature the model and its results have been largely overlooked by engineers. The attempt to extend the appeal of the dusty-gas model to engineers is broadly successful, although an engineer will not find within this volume detailed correlations for effective diffusion coefficients in porous media. Instead, the authors have concentrated upon the development of the proper equations of transport for the process so that the further work of developing appropriate correlations should have a secure foundation. The book is divided into three main sections: theory, experiment and applications.The dusty-gas model and its accompanying theory are developed in two stages, first by way of elementary arguments, which illustrate the essential features of the transport mechanisms in porous media, and secondly by means of a full kinetic-theory description. The physical insight given by the elementary approach is of considerable assistance to the understanding of the more involved material. In particular, the utility of the dusty-gas model in separating the formulation1670 REVIEWS OF BOOKS of the transport equations from the structure of the porous medium is shown very clearly. In the experimental section a considerable body of experimental evidence is adduced to support the applicability of the dusty-gas model. The experimental results generally refer to situations which are rather more simple than those encountered in engineering practice.However, the illustration of the way in which the proper transport equations can be employed to isolate the parameters characteristic of the medium which occur within them is important as a guide to more general applications. Furthermore, the remarkable success of the dusty-gas model for these simple cases inspires confidence in its application to more complicated situations. In the final section the dusty-gas model is applied to four diverse problems: slip and creep in rarefied gases, the radiometer effect, aerosol motion and membrane transport for solutions. These represent but a small selection of situations in which the model may be employed and, with the guidance of this excellent book, the number of engineering problems tackled from this viewpoint should increase rapidly.W. A. WAKEHAM Received 29th November, 1983 Calculations in Advanced Physical Chemistry. By P. J. F. GRIFFITHS and J. D. R. THOMAS. The fact that this is a third edition demonstrates the usefulness of the volume to students and teachers of physical chemistry over a number of generations since its first appearance in 1962. It should perhaps be remarked that ‘advanced’ in this context is meant to indicate post A level. Most of the questions are taken from first-degree examinations but the authors have confined their sources neither to B.Sc. chemistry courses nor to universities only in the United Kingdom. The subjects included cover the main areas of physical chemistry from thermodynamics to radiochemistry, with a fairly heavy weighting towards solutions (particularly electrical properties) and thermodynamics (which in this edition includes statistical thermodynamics). The authors are to be commended for including a short section on the statistical treatment of experimental data.Generally the questions and answers are not comprehensible without reference to the text books in the field, and occasionally it is necessary to understand the limitations to the level of background information expected in the student in order to follow the solution given. The book could be a very useful aid to students studying, and to teachers running, courses in physical chemistry, if the relationship to the course in question is made clear and the relevant questions pinpointed.It is also a book which could be available in departmental libraries for background reading, and student ‘ self-help ’ in problem solving. That the problem-solving exercise may itself stimulate further dips into the text books or questions to the teacher is a beneficial result to be encouraged. J. S. HIGGINS (Edward Arnold, London, 3rd edn, 1983). Pp. viii + 303. Price lf8.95. Received 22nd November, 1983 Adsorption from Solution at the Solid/Liquid Interface. G. D. PARFITT and C. H. ROCHESTER. Adsorption at the interface between solids and solutions has long been a favourite study for colloid chemists. Many hundreds of research papers testify to the importance of its practical applications, which are far too numerous to list but are at least as diverse as paints and lubricants, detergents and ion exchangers, flotation of minerals and flocculation of effluents, to mention a few.Consequently, this well balanced front-line monograph will have wide appeal. I enjoyed reading the book. It is pleasant to handle, well set out and mentally stimulating. The contributors have distilled years of experience into mature and free-ranging essays, a format which provides a refreshing change from contorted journal papers, dreary ‘ recent advances’ reviews or collections of conference papers masquerading as monographs. Who says that scientists cannot write? All these articles are very clearly written and several (Academic Press, London, 1983). Pp. xi +412. lf49.50, $79.50.REVIEWS OF BOOKS 1671 can boast quite splendid command of English.Lyklema’s chapter on the Adsorption of Small Ions, in particular, is a superb piece of terse, Churchillian prose, as well as being a masterpiece of exposition of a difficult topic. It could well be recommended as a model for students of colloid science or electrochemistry. Parallel compliments apply to the physical chemistry in the articles. Despite skipping mathematical derivations, it is no walk-over to read from cover to cover; for the 400 pages are packed with concentrated colloid science, theory and experiment in balanced collaboration. One is impressed both by the range of factual information and by the quality of the critical thought that has gone into these articles. Criticism is levelled equally fairly at inadequate experiments, naive interpretations and over-simplified theoretical excursions.More than once we are reminded that one successful spree of curve-fitting is not necessarily proof of the validity of the model assumed! (One recalls, as a simple example, the much misused Langmuir isotherm which often fits data-roughly, anyway-but is rarely, if ever, a realistic theoretical model for adsorption from solutions. Similarly, some optimists need reminding that ‘ specific surface area’-that sacred cow of classical surface chemists-has no precise meaning for the majority of adsorbents, because many are microporous or heterogeneous (e.g. charcoal) or penetrable (as are fibres and plastics). More subtle are questions concerning the reality or otherwise of specific adsorption of ions.After perusing this book, an overall impression of the state of research in this field looks broadly as follows. On the one hand there are those purists who aim to test fundamental models. They are obliged to search for quasi-ideal systems such as benzene + toluene + graphitized carbons. They are then faced with analytical problems and ‘composite isotherms ’, while, even here, the surface thermodynamics is formidable, as Dr Lane’s article shows. On the other hand, the majority of adsorption systems are nowadays recognized to incur a variety of complications, which divorce them from fundamental theory. The problem here is to sort out the priorities in the hope of arriving at some plausible, perhaps semi-quantitative, overall interpretation.In this group, the expected complications may well include several of the following: surface heterogeneity; porosity ; lateral interactions; polymer effects ; peculiar interactions of polar, non-polar and, especially, hydrophobic moieties of molecules ; ionic size and hydration effects; micellization in solution or at the interface (maybe both); ‘ specific adsorption ’ or chemisorption; or just frank metathetical surface reactions (which can mimic adsorption if reversibility is not properly tested). The present monograph shows how progress is being made through improved experimental measurements (including sophisticated in situ spectroscopic techniques and microcalorimetry) in conjunction with successive theoretical approximations. The book would provide the best possible starting point for the next generation of research on adsorption from solution, and it would be foolish to start without first studying it deeply.Considering the staggering cost nowadays of mounting a single top-rank research project, ca. E50 is not really expensive for a valid ‘embarkation ticket’ for a worthwhile expedition. Similarly, it could soon save its cost in many industrial research laboratories, where adsorption is pertinent, by dispelling ignorance. Chemistry department libraries should scrape the barrel for it. There is a rather brief Subject index but no Author index. Received 5th January, 1984 J. A. KITCHENER Polymer Science and Technology, Volume 20. Polymer Alloys 111, Blends, Blocks, Grafts and Interpenetrating Networks. By D. KLEMPNER and K. C. FRISCH. (Plenum Press, New York, 1983). Pp ix+302. Price $45. This book presents the proceedings of the Symposium on Polymer Alloys, sponsored by the American Chemical Society’s Division of Organic Coatings and Plastics Chemistry, held at the 182nd meeting of the American Chemical Society in New York, in August 1981. There are 18 papers covering such topics as the mechanical properties, processing, rheology and analysis of polymer blends. The first paper concerns model composites prepared from emulsion polymers. There then follow four papers from the group at Donetsk, U.S.S.R. onI672 REVIEWS OF BOOKS the correlations between processing conditions, morphology and mechanical properties of high-impact polystyrenes. The next two papers address the characterisation of blends, one describing a fractionation method for the separation of polymers in the blend and the other the use of Fourier-transform infrared spectroscopy in crystalline/compatible blends. A set of three papers then describe aspects of the rheology and compounding of blends. After a paper on wood-polymer composites there then follows a review of morphology in interpenetrating networks, a description of some RIM systems from interpenetrating networks and a discussion of morphology in some segmented polyurethanes. The last three papers are arguably not on the subject of the book at all, being concerned with alternating and random copolymers and the modification of cotton. As with most books which present the proceedings of meetings, it contains a range of quality of papers: good, bad and indifferent. Although the papers are grouped mostly in one subject area such a book can rarely have a coherent theme, and each paper must stand or fall on its own merit. This particular book is better than most of its kind in that some of the papers are quite useful summaries or reviews of various areas of work. These could be of use to anyone for whom that area was one of peripheral interest or was new to that person. It should be said that papers in such books are not usually of as high a quality as those found in the better journals. Refereeing is often non-existent and editors sometimes have little choice but to take what contributors give them. Nor do they serve the purpose of a well produced book with a well ordered structure, or of those journals or books which present collections of comprehensive reviews. One has to doubt their cost-effectiveness as a means of transferring information. One wonders if they would exist at all if it were not for the desire of the publishers to produce more books and the need of the authors to increase their list of publications. If the proceedings of conferences were not published, any paper or review with individual worth would have no difficulty in finding a home elsewhere. This particular book is well produced and contains a collection of references at the end of each chapter and an index. It will be worth buying for libraries in centres where there are active groups in the area of polymer blends, but I doubt whether many people will wish to buy a copy of their own. D. J. WALSH Received 29th November, 1983

ISSN:0300-9599    

DOI:10.1039/F19848001657

出版商:RSC    

年代:1984

数据来源: RSC