MEASUREMENT, ANALYSIS, AND UTILITY OF EXCESS MOLAR - (PARTIAL-DERIVATIVEV/PARTIAL-DERIVATIVEP)S

The aim of this article is to demonstrate the importance of the quantity -(partial derivative V/partial derivative p)s, by identifying the place that it occupies in the hierarchy of thermodynamic properties of liquid mixtures and by exploring its significance. After a brief survey of experimental techniques, emphasis is placed upon a procedure for examining its composition dependence for (amphiphile + water) mixtures. Detailed analyses of the excess molar quantity [- (partial derivative V/partial derivative p)s]E and of other related properties of [amphiphile + water] systems have been performed by means of a segmented composition curve-fitting procedure. These reveal that even relatively small amphiphiles tend to adopt patterns of molecular aggregation that mimic those of their detergent homologues.