Dielectric approach to polystyrene microcapsule analysis and the application to the capsule permeability to potassium chloride

A method of numerical analysis is proposed to determine the phase parameters from dielectric observations of polystyrene microcapsules by using the conductivity at intermediate frequencies between two dielectric relaxations observed. The method was more feasible for the analysis of the microcapsule observations than the method by which the calculation is performed by use of the permittivity at lower frequencies. The method was applied to the dielectric observations of the KCl-loaded microcapsules to obtain the permittivity and the conductivity of the capsule interior, the thickness of the capsule wall, the volume fraction of the suspended capsules and the conductivity of the surrounding aqueous phase. The conductivity of capsule interior was found to be unchanged with time for as long as 3 months. From the results it is concluded that the microcapsules are impermeable to KCl.     

Letter to the Editor

Abstract

Dear Sir

With respect to the article “Collection and Analysis of Rainwater etc.” (Slanina et al., vol. 7, pp. 161-176), my remarks on this article (vol. 9, pp. 221-223) and the answer of Mr. Slanina (vol. 9, pp. 223-225), I should like to make my final remarks as follows.