Influence of structural factors on the adsorption of gases by charcoal.

Note: Author’s signature redacted from title page.The protection of wet and dry S.B.T. charcoals towards phosgene has been shown to improve at reduced temperatures. The nature of adsorption of nitrogen, butane and water on a series of charcoals of varying degrees of activation has been studied by determinations of adsorption isotherms and surface areas. Calculations of charcoal pore radius, pore volume and surface wetted by adsorbed water have been made. The extent of surface and the configuration of the capillaries have been found to be the principal criteria in determining the adsorptive capacity of a charcoal. A steric factor, dependent upon the dimensions of these capillaries, is postulated as limiting the accessibility of large molecules to the pores. A theory of water adsorption is proposed which suggests that about sixty percent of the charcoal surface is contained in pores of less than twelve Angstrom units in radius and is inaccessible to water molecules