界面電氣の硏究(第7報) : 振動法による流動電位の測定(1)

Abstract

When fluid is forced by pressure through a diaphragm or capillary an electromotive force, so-called "streaming potential", is generated. Up to the present, constant pressure has been used and the streaming potential has been measured by electrostatic method. But we used periodically changing pressure, e.g. simple harmonic motion of moving coil, and succeeded in measuring the potential as an alternating voltage. Applying this method, we first measured the streaming potential of various salt solutions (KCl, KI, K4Fe (CN)6, etc.) at various concentrations (from 10-2 to 10-7 norm.). From the change of the potential generated by various salt solutions of different concentration at constant amplitude of vibration, it was proved that the more dilute the solution was the larger the potential was. The potential-concentration curve gave a considerable parallelism with the results measured by the ordinary electrostatic method after Lacks and Biczyk. We measured secondly the change of electromotive force with the amplitude of vibration at 10-2, 10-3, 10-6 norm. K4Fe (CN)6 aq. solution and 10-5 norm. KC1 10% alcoholic aq. solution respectively, and compared them with Ettisch and Zwanzig's results. Contrary to their results, we got a linear relation between them in both cases. This means that the electrokinetic potential is independent of the pressure. We are carrying on more detailed experiments and theoretical treatise. They shall be reported in next report.