Adsorption of Water Vapour on Solid Surfaces

Abstract

IN their recent communication¹, Dr. F. P. Bowden and Mr. W. R. Throssell reported conclusive quantitative evidence against the view at one time widely held that metal surfaces invariably adsorb water vapour strongly from air at high relative humidities. In my work of some years ago on the gravimetric determination of thin oxide films, more especially those formed at room temperatures, no attempt to determine adsorption per se was made; nevertheless, the general results led strongly to the view (for which confirmation was forthcoming in contemporary literature²) that adsorption of water vapour is negligible provided that both the metal surface and the atmosphere are free from contamination. Iron was found to be particularly susceptible to the presence of disperse solid particles (for example, traces of ammonium sulphate³), while nickel provided an extreme case of susceptibility to gaseous pollution (for example, traces of sulphur dioxide⁴).