Langmuir 1996, 12, 5971
Additions and Corrections The Random Contact Equation and Its Implications for (Colloidal) Rods in Packings, Suspensions, and Anisotropic Powders Albert P. Philipse Langmuir 1996, 12, 1127-1133. The quantity 〈c〉 in eq 1 is the ratio of the total number of contacts and particles. This should be clearly distinguished from the quantity 〈γ〉, defined here as the average number of contacts experienced by a certain particle: 〈γ〉 ) 2〈c〉. For rods, terms in the text like “contacts”, “rod contacts”, and “contacts per rod” always denote 〈c〉. For spheres, however, the two quantities are confused. For the random sphere packing in section 2.2, 〈γ〉 ≈ 6 and 〈c〉 ≈ 3. So in the random contact approximation the random sphere packing density is Φ ≈ 0.75 instead of 1.5. The experimental value 〈c〉 ≈ 5.4 for rod packings (section 3) exceeds the value for spheres and does not support the conjecture that 〈c〉 may be an invariant for dense random packings. Note also that 〈γ〉 instead of 〈c〉 is needed to evaluate the attraction energy per rod in section 6. Hence the right-hand side of eqs 19-21 should be multiplied with 2. Further, “ref 29” in Table 1 should read “ref 34 a”, and ref 2 should read as follows: (2) Jackson, G. W.; James, D. F. Can. J. Chem. Eng. 1986, 64, 364. LA960869O
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© 1996 American Chemical Society
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