Dielectric Relaxation in Some Two-Component Systems

Dielectric relaxation measurements were made on a number of two-component systems involving both associated and nonassociated liquids. A single dispersion was found for a mixture containing two alkyl halides. A mixture containing an alkyl halide and an alcohol showed two dispersion regions, the separate complex plane loci being similar in form to the dispersions found for the separate components. The locus of the dispersion in several alkyl halide-hydrocarbon mixtures was not significantly different from that in the pure halides although small deviations of unknown origin were observed at low frequencies. In the 1-propanol-2-methylpentane mixtures studied, the relative amplitudes of the multiple dispersions, characteristic of the alcohol, were little affected down to a concentration of 33 mole percent 1-propanol but had changed drastically at a concentration of 14 mole percent 1-propanol. The results are discussed in terms of Schallamach's suggestions concerning the molecular nature of these mixtures and the size of the liquid region involved in the dielectric relaxation process.