On the phenomenological theory of diffusion

✍ Scribed by H.M.J. Boots; J.M. Deutch

• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 551 KB
• Volume: 94
• Category: Article
• ISSN: 0378-4371
• DOI: 10.1016/0378-4371(78)90130-9

✦ Synopsis

A phenomenological theory of diffusion is given along the lines of the treatment of De Groot and Mazurl). Simple relations between the diffusion matrices of the various kinds of composition variables are established. In linear approximation all kinds of composition variables obey Fick's second law. The special role of the mean volume velocity is discussed and attention is given to Onsager coefficients and mobilities (friction coefficients).

* Sometimes one uses volume fractions according to eq. ( 2.3) with M~ some characteristic volume per mole of component L In that case the analysis in sections 2 and 3 applies.

From eq. (B.I) we see that v ° = v a if p" is constant. On the other hand v a = 0 for constant pa (see section 5) so that v ° has to vanish as well.