Permeabilities through the gelatin membrane were measured with three electrolytes, KSCN, KCl, and K
2SO
4, and the effect of gelatin content was studied. The permeability coefficient in the membrane, P
*, decreases along the sigmoid curve with increasing gelatin content. The rate constant of permeation at the interface, k, remains constant even when gelatin content varies. The values of k in the case of KSCN, KCl, and K
2SO
4 were individually 0.89, 0.80, and 0.57×10
-3, respectively. With increasing gelatin content of the membrane, the corresponding membrane thickness, L
*(=P
*/k), decreases, expressing the resistance at the interface to diffusion. L
* of three electrolytes are on the identical curve. The parameters of interaction between gelatin and electrolytes were calculated from the apparent membrane constant, f
*, with reference to that of KCl. In the low content of gelatin, there are no differences in the affinity between three electrolytes and gelatin, but differences appear with increasing gelatin content. The affinity of KSCN becomes greater and that of K
2SO
4. less than that of KCl. The relation between the porosity and tortuosity of the membrane was also calculated.
抄録全体を表示