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Sorption of Water Vapour on Glass Surface in Vacuum Apparatus

1962; Physical Society of Japan; Volume: 17; Issue: 1 Linguagem: Inglês

10.1143/jpsj.17.218

1347-4073

Yutaka Tuzi,

Chemical and Environmental Engineering Research

The sorption and the desorption of water vapour on borosilicate glass have been studied at temperatures between 3.8° and 46.6°C and at a pressure of 10 -5 Torr using the constant pressure method. A part of the sorption process is diffusion of water molecules into a surface layer of glass which is named “hygroscopic surface layer.” The activation energy of diffusion is 7∼11 Kcal/mole, and the diffusion constant is about 10 -18 cm 2 /sec. The sorption and the desorption on borosilicate glass surface covered with a thin film of diffusion pump oil, Lion A, Octoil, S, Apiezon C or Myvane, have also been investigated. The results are similar to those for clean glass surface.