Colloid and Polymer Science

, Volume 269, Issue 5, pp 483–489 | Cite as

Surface characterization and heats of adsorption of chromatographic alumina gel

  • M. Afzal
  • M. Khan
  • H. Ahmad
Original Contributions


The porous nature of chromatographic alumina gel has been investigated by adsorption/condensation processes and electron microscopy. Having 63% porosity, the gel is very porous. Total pore volume as determined by the fluid-displacement method is 0.497 cm3 g−1. Its specific surface area, as determined by water vapor adsorption, is 225 m2 g−1. Micropore volume, as determined by utilizing Gurwitsch's rule, turns out to be 0.262 cm3 g−1. The greater portion of the surface area and pore volume occurs in small and transitional pores, with average pore radii (hydraulic) less than 2.1 nm.

Organic vapors, such as methyl ethyl ketone, acetone, methyl acetate, and methyl alcohol, were adsorbed on the gel between 0 and 36°C under vacuum, and the data were recorded on a Cahn-1000 electrobalance device. Isosteric heats of adsorption were calculated by applying the Clausius Clapeyron equation to the adsorption isosters at different surface coverages. Two types of adsorption processes, one with low activation energy and other with high activation energy can be distinguished. The increase in values ofq st indicates that increasing temperature changes physical adsorption into chemisorption.

Key words

Surface characterization heats of adsorption alumina gel surface studies adsorption thermodynamics 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Afzal M, Muzzaffar K (1987) J Chem Soc Pak 9(3)Google Scholar
  2. 2.
    Afzal M, (1971) Kolloid-Z u z Polymere 248:1026Google Scholar
  3. 3.
    Afzal M, Jaffer M, Yasmin S (1977) Colloid Polym Sci 255:252Google Scholar
  4. 4.
    Afzal M, Jaffer, Ahmed J, Parveen N (1978) Colloid Polym Sci 256:356Google Scholar
  5. 5.
    Afzal M, Ahmed J (1975) Colloid Polym Sci 253:635Google Scholar
  6. 6.
    Afzal M, Singer N (1972) Pak J Sci Ind Res 15(3):137Google Scholar
  7. 7.
    Afzal M, Ahmed J, Saleem M (1984) J Chem Soc Pak 6(4):245Google Scholar
  8. 8.
    Afzal M, Ahmed J, Butt PK (1985) Pak J Sci Ind Res 28(3):163Google Scholar
  9. 9.
    Afzal M, Butt PK, Ahmed N (1973) Pak J Sci Ind Res 25(4):171Google Scholar
  10. 10.
    Afzal M, Khan M (1986) J Chem Soc Pak 8(4):469Google Scholar
  11. 11.
    Kiselev AV (1945) USP Khim 14:367Google Scholar
  12. 12.
    Shull CG (1948) J Amer Chem Soc 70:1405Google Scholar
  13. 13.
    Mikhail RSH et al (1979) J Colloid Interface Sci 70(3)Google Scholar
  14. 14.
    Spencer DHT (1967) Porous carbon solids, p 87Google Scholar
  15. 15.
    Brunauer S, Mikhail RSH, Boder EE (1967) J Colloid Interface Sci 24:451Google Scholar
  16. 16.
    Young DM, Crowell AD (1962) Physical adsorption of gases. Butterworth, London, p 198Google Scholar
  17. 17.
    Brennan D et al (1963) Nature 199:1152Google Scholar
  18. 18.
    Pierce C, Nelson SR (1950) J Phys Chem 54:795Google Scholar
  19. 19.
    Harry P et al (1986) J Chem Phys 84(11):6507Google Scholar
  20. 20.
    Beebe RA et al (1953) J Amer Chem Soc 75:657Google Scholar
  21. 21.
    John Moor et al (1953) J Amer Chem Soc 75:657Google Scholar
  22. 22.
    Barrier RM (1937) Proc Roy Soc (London) 161A:476Google Scholar
  23. 23.
    Pierce C et al (1951) J Amer Chem Soc 73:4551Google Scholar

Copyright information

© Steinkopff-Verlag 1991

Authors and Affiliations

  • M. Afzal
    • 1
  • M. Khan
    • 1
  • H. Ahmad
    • 1
  1. 1.Department of ChemistryQuaid-Azam UniversityIslamabadPakistan

Personalised recommendations