Book Reviews

Adsorbent‐adsorbate Interactions and Surface Heterogeneity in Physical Adsorption

“…We note for future reference that if CZ = 0, EQUATION [2][3][4][5][6][7] reduces to Uo = and EQUATION 2-8 reads -roG (2)(3)(4)(5)(6)(7)(8)(9) presented in FIGURE 1. the magnitude of the attractive energy a t the equilibrium distance Y O .…”

“…According to EQUATION F o r j = 3, faJ = 6; for j = 1,4, n, = 8; and for j = 2,5, n, = 12. Substitution of these values in the last of the relations 2-11 leads to W(z) = npro3{Uo(q5/5 -2q9/45) (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) -(Ci/2ro6)($/3 -q5/5 f q9/45)) with q = ro/z. A plot of EQUATION 2-12 is given in FIGURE 3 for the hypothetical case YO = 3.5 A. and C2/Cll = 3 x thus U O = -1.16(C1/ZrOe).…”

“…A final simplification can be effected by neglect of the repulsion potential (setting C4 = 0). EQUATION 2-12 now reduces to (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) W2(z) = -apC1/6z3 a relation first derived by Londonss and discussed frequently in the literature.lg* 3 2 , 3 5 , 99 A plot Wz versus z is shown in FIGURE 2c. Under the assumed conditions, it reproduces the more complex equations quite well in the range z 3 ro .…”

“…in EQUATION One now obtains from Owing to the existence of a second derivative on the right and since ~ ( 7 ) is not evaluated directly, EQUATION 5-37 seems to have little practical value.…”

“…Modifications of the original treatment have been introduced where necessary to exclude physically unacceptable b or e values. Readers who do not wish to wade through all the mathematical details may go directly to EQUATION where Differentiate (5-10) with respect to q, assuming that the differentiation under the integral sign is permissible, (5)(6)(7)(8)(9)(10)(11)(12) J-m It may be readily verified that the function h' = eE-?/(l +et-,)* depends only on the absolute difference I C;q I .…”