The constitution of reversed micelles of C6F13COOH (perfluoroheptanoic acid, PFHA) in a chlorofluorocarbon medium (1,1,2-trichlorotrifluoroethane, TCFE) was characterized by a number of techniques, including IR, NMR, and UV-vis and fluorescence probes. Dimensions of these reversed micelles were determined by quasielastic light scattering. With increasing concentration of surfactant in TCFE, the estimated diameter of the water pool in the reversed micelles increased, the estimated aggregation number of the reversed micelles increased, and the estimated wt% water increased. These estimates were consistent with the results of the probe studies and Karl Fischer titrations. Adsorption of fluoroacids from this solvent onto alumina showed cooperative interactions between head groups.