Barragán V M, Ruiz-Bauzá C, Imaña J L
Dpto. Física Aplicada I, Facultad de Física, Universidad Complutense de Madrid, 28040 Madrid, Spain.
J Colloid Interface Sci. 2006 Feb 15;294(2):473-81. doi: 10.1016/j.jcis.2005.07.034. Epub 2005 Aug 15.
Streaming potential measurements across charged membranes separating two equal solutions have been carried out. Two cation-exchange membranes with different cross-linked and swelling properties (Ionics and Nafion membranes) and methanol-water electrolyte solutions of KCl have been used in the experiments. The obtained results show that the streaming potential is higher for the Ionics membrane and that the values depend on the methanol content of the solutions. A different behavior is found in the dependence of the streaming potential on the methanol percentage for each membrane. The study of the relaxation times in the decay of electrokinetic steady states of streaming potential has been carried out from the time dependence of the streaming potential when the pressure difference through the membrane is suppressed. The results show the existence of two different parts or partial relaxations, mechanical and electric. A different behavior of the mechanical relaxation time with the methanol percentage has been found for the two membranes, but any significant difference between their electric relaxation times. These differences have been explained in terms of the different degree of swelling of the membranes used.
已经对跨越分隔两种等渗溶液的带电膜进行了流动电势测量。实验中使用了两种具有不同交联和溶胀特性的阳离子交换膜（Ionics膜和Nafion膜）以及KCl的甲醇 - 水电解质溶液。所得结果表明，Ionics膜的流动电势更高，且该值取决于溶液中的甲醇含量。对于每种膜，流动电势对甲醇百分比的依赖性表现出不同的行为。当通过膜的压力差被抑制时，根据流动电势的时间依赖性，对流动电势电动稳态衰减中的弛豫时间进行了研究。结果表明存在两种不同的部分或部分弛豫，即机械弛豫和电弛豫。对于两种膜，发现机械弛豫时间随甲醇百分比有不同的行为，但它们的电弛豫时间之间没有任何显著差异。这些差异已根据所用膜的不同溶胀程度进行了解释。
