Note de laboratoire. Quelques remarques sur les mesures de viscosité

Ultrafilter Membranes and Ultrafiltration.

“…The opposite extreme in explaining semipermeability was reached by the capillary attraction theory (45a, 272, 284), which represents the solvent as strongly adsorbed in the pore and transmitted by surface mobility of the adsorbed molecules; and by the theory of partial solubility (179a), which represents the solvent as dissolving into the membrane on one side and out on the other. These theories would, however, predict specific effects dependent on the nature of solute and solvent, whereas the experiments of Duclaux and Errera in 1924 (82,83) demonstrated the sieve-like behavior of membranes in the flow of various liquids through them, and the work of Collander in 1926 (75) showed that the rate of impeded diffusion of crystalloidal molecules through membranes depended principally on the molecular volume and not on the nature of the diffusing solute. On the whole, there is adequate support for the viewpoint that the fundamental mechanism in ultrafiltration is sieving, modified by adsorption, blocking, and other effects arising from the very large ratio of pore length to pore width and of pore surface to cross-section area in all ultrafilters.…”