The Stern-Grahame-Devannthan theory of the electrical double layer in aqueous systems is modified to include the so-called discreteness-of-charge effect of Esin and Shilcov and Ershler. This provides an explanation of a n~~m b e r of phenomena which are a t variance nrith the Stern theory. A simple method of incorporating the above effect into the Stern theory is suggested by the work of Grahame and is equivalent in principle to the discrete-ion approximation einployed by the Russian authors. It is shown that the effect can be interpreted in terms of a 'self-atmosphere' potential a t the counterions adsorbed in the Stern layer. This provides a new term in the energy of an adsorbed ion, which is very nearly proportional to the surface density of these ions and which had hitherto been included in the specific adsorptioi~ potential in the Stern adsorption isotherm. This energy is not small and accounts for the conclusion reached by Grahame that the adsorption potential varies strongly with the surface charge. Grahame found that the potential a t the plane separating the compact and diffuse parts of the double layer in the solution phase (i.e. the outer Hellnholtz plane) a t the mercuryaqueous electrolyte interface displays a lnaxi~nuin as the poteiltial across the interface is varied, and this property is reproduced by the theory. The effect of ion size on the adsorption isotherm is also considered.

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In this work we apply the Hayashi-Nishi method for quantitatively analyzing the state of mixing of a secondary component in a polymeric matrix. We (1) evaluate the method using computer-generated morphologies and (2) compare the state of mixing of a core-shell impact modifier in polymers having differing affinity for the impact modifier. In the Hayashi-Nishi method two numbers, related to dispersion and distribution, are required to quantify the state of mixing of a secondary phase in a polymeric matrix. The 5-parameter in the Hayashi-Nishi method is defined asThe Ai's are the areas of each individual secondary phase particle or aggregate and nis the number of such particles in the image. S is related to the size distribution of these aggregate areas and is a measure of dispersion of the secondary phase in that particular image.