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Block copolymer micelles formed by diblock and triblock copolymers of styrene and methacrylic acid were characterized in solution in a mixed solvent with 80 vol % of dioxane and 20 vol % of water. Methods of static light scattering, quasielastic light scattering, differential refractometry, viscometry, sedimentation velocity, and densitometry were used. No unattached unimer molecules were observed. Three independent methods were employed for obtaining micellar weights. They agreed well with each other. No anomalous behavior was observed by any method. The micellar solutions were shown to contain almost exclusively single micelles; only a few samples (those producing the largest micelles) contained micellar clusters. The micelles behaved hydrodynamically and thermodynamically as impermeable spheres. The structure of the micellar shell was characterized in some detail. Relations between the aggregation number and the hydrodynamic radius of the micelles on the one hand and the sizes of the styrene and methacrylic acid blocks on the other were presented as scaling type phenomenological equations.Physicochemical properties of self-assembling molecules are of ever increasing experimental and theoretical interest. This is not only due to the intriguing phenomenon of selfassembling but also due to important applications of such materials in coatings, adhesives, thin films, microfabrication of electronic devices, pharmaceutical and photographic technologies, oil recovery, etc. Among the most important self-assembling systems are polymeric micelles.

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Excess volumes were calculated from measured densities of binary mixtures of five linear alkanols (methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol) with five n-alkyl acetates (methyl, ethyl, propyl, butyl, and pentyl acetates) and with two ketones (acetone and 2-butanone) at 20 °C. The whole composition range was studied for all thirty-five binary systems. For a given alcohol, the ∆V/φ1ϑ2 value decreases with increasing size of the carbonyl compound. For a given carbonyl compound, it increases with the length of the alkanol. Systems with methyl acetate as one component have relatively large ∆V/φ1ϑ2 values, while systems with methanol display different compositional dependency in respect to systems with other alcohols.

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