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Chemical Processes where Size and Shape are Important

  • R. B. Barlow

Abstract

It has long been known that molecules may become concentrated, i.e. adsorbed, at the surfaces of some solids. This is of practical value, for instance, when charcoal is used to remove traces of coloured impurities from solutions or to adsorb vapours in domestic cooker-hoods and in gas masks. It might be expected that the amount adsorbed for a given weight of adsorbing material would depend on the partial pressure or concentration of the adsorbed species and on its nature, thus:
$$x = K{P^n}$$
where x is the amount adsorbed for unit mass of adsorbent, P is the partial pressure of the adsorbed material (or concentration if it is in solution) and K and n are constants. This expression, known as the Freundlich adsorption isotherm, was originally arrived at empirically and has been found to fit many experimental results. It can be written:
$$\log x = \log K + n\log P$$
so the graph of log x against log P should be a straight line with a slope of n and an intercept of −logK/n when log x = 0. There should be no upper limit to the amount which can be adsorbed and as the partial pressure is increased it should eventually reach the saturated vapour pressure and condensation will occur.

Keywords

Langmuir Isotherm Partial Agonist Receptor Occupancy Quantitative Aspect Affinity Constant 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    I. Langmuir, Journal American Chem. Soc. (1916), no$138, p. 2221; ibid. (1918), no. 40, p. 1361.CrossRefGoogle Scholar
  2. 2.
    A. V. Hill, Biochem. Journal (1913), no. 7, p. 471; Biochem. Journal (1921), no. 15, p. 577Google Scholar
  3. W. E. L. Brown and A. V. Hill, Proc. Roy. Soc. B. (1923), no. 94, p. 297.CrossRefGoogle Scholar
  4. 3.
    G. Scatchard, Ann. NY Acad. Sci. (1949), no. 51, p. 660.CrossRefGoogle Scholar
  5. 4.
    I. M. Klotz, J. M. Urquhart and W. W. Weber, Arch. Biochem. (1950), no. 26, p. 427.Google Scholar
  6. 5.
    E. De Robertis, G. S. Lunt and J. L. La Torre, Mol. Pharmacol. (1971), no. I, p. 97.Google Scholar
  7. 6.
    H. Lineweaver and D. Burk, Journal American Chem. Soc. (1934), no. 56, p. 658.CrossRefGoogle Scholar
  8. K. B. Augustinsson, Acta Physiol. Scand. (1948), no. 15, suppl., no. 52, p. 100.Google Scholar
  9. 8.
    B. H. J. Hofstee, Science (1952), no. 116, p. 329.CrossRefGoogle Scholar
  10. 9.
    A. J. Clark, `General Pharmacology’, Handbuch der Experimentellen Pharmakologie, IV ( Springer, Berlin, 1937 ), p. 64.Google Scholar
  11. 10.
    E. J. Ariens and J. M. van Rossum, Arch. int. Pharmacodyn. (1957), no. 110, p. 275.Google Scholar
  12. 11.
    R. P. Stephenson, British Journal Pharmacol. (1956), no. 11, p. 379.Google Scholar
  13. 12.
    J. H. Gaddum, Journal Physiol. (1937), no. 89, p. 7 P.Google Scholar
  14. 13.
    H. O. Schild, British Journal Pharmacol. (1947), no. 2, p. 189; ibid. (1949), no. 4, p. 277.Google Scholar
  15. 14.
    O. Arunlakshana and H. O. Schild, British Journal Pharmacol. (1959), no. 14, p. 48.Google Scholar
  16. 15.
    M. Nickerson, Nature (1956), no. 178, p. 697.CrossRefGoogle Scholar
  17. 16.
    J. H. Gaddum, Trans. Faraday Soc. (1943), no. 39, p. 323; Pharmacol. Review (1957), no. 9, p. 211.Google Scholar
  18. 17.
    R. F. Furchgott, in Advances in Drug Research 3, N. J. Harper and A. B. Simmonds (eds.) ( Academic Press, London, 1966 ), p. 21.Google Scholar
  19. 18.
    R. B. Parker and D. R. Waud, Journal Pharmacol. (1971), no. 177, p. 1.Google Scholar
  20. 19.
    W. D. M. Paton, Proc. Roy. Soc. B. (1961), no. 154, p. 21.CrossRefGoogle Scholar
  21. 20.
    F. Roberts and R. P. Stephenson, British Journal Pharmacol. (1976), no. 58, p. 57.Google Scholar
  22. 21.
    B. Katz and S. Thesleff, Journal Physiol. (1957), no. 138, p. 63.Google Scholar
  23. 22.
    L. G. Magazanik and F. Vyskocil, in Drug Receptors, H. P. Rang (ed.) ( Macmillan, London, 1973 ), p. 105.Google Scholar
  24. 23.
    H. P. Rang and J. M. Ritter, Mol. Pharmacol. (1969), no. 5, p. 394; ibid. (1970), no. 6, pp. 357, 383; H. P. Rang, British Journal Pharmacol. (1973), no. 48, p. 475.Google Scholar
  25. 24.
    A. Takeuchi and N. Takeuchi, Journal Physiol. (1969), no. 205, p. 377.Google Scholar
  26. 25.
    D. Colquhoun, in Drug Receptors, H. P. Rang (ed.) ( Macmillan, London, 1973 ), p. 149.Google Scholar
  27. 26.
    E. C. Hulme, N. J. M. Birdsall, A. S. V. Burgen and P. Mehta, Mol. Pharmacol. (1978), no. 14, p. 737.Google Scholar
  28. 27.
    N. J. M. Birdsall, A. S. V. Burgen and E. C. Hulme, Mol. Pharmacol. (1978), no. 14, p. 723.Google Scholar
  29. 28.
    J. Monod, J. Wyman and J-P. Changeux, Journal Mol. Biol. (1965), no. 12, p. 88.CrossRefGoogle Scholar
  30. 29.
    L. Pauling, The Nature of the Chemical Bond (Cornell University Press, Ithaca, New York, 1939); ibid., 3rd edn (1960).Google Scholar
  31. 30.
    A. Albert, Selective Toxicity,1st edn (Methuen, London, 1951), Table 1, p. 26; ibid., 5th edn (1973), p. 222.Google Scholar
  32. 31.
    F. Franks, Chemistry and Industry (1968), p. 560Google Scholar
  33. M. J. Tait and F. Franks, Nature (1971), no. 230, p. 91CrossRefGoogle Scholar
  34. C. J. Tanford, The Hydrophobic Effect ( Wiley, New York, 1973 )Google Scholar
  35. A. Suggett, in Biological Activity and Chemical Structure, J. A. Keverling-Buisman (ed.) ( Elsevier, Amsterdam, 1977 ), p. 95.Google Scholar

Copyright information

© R.B. Barlow 1980

Authors and Affiliations

  • R. B. Barlow
    • 1
  1. 1.University of BristolUK

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