J. Phys. II France
Volume 4, Numéro 9, September 1994
Page(s) 1469 - 1475
DOI: 10.1051/jp2:1994212
J. Phys. II France 4 (1994) 1469-1475

Associating behaviour of pure polar liquids: dielectric properties of lauric acid

E.R. Mognaschi and L.M. Laboranti

Dipartimento di Fisica "A. Volta" dell'Università, Pavia, Italy

(Received 15 April 1994, accepted 14 June 1994)

In this paper measurements of the static dielectric permittivity of lauric acid at different temperatures from about 10 K above the MP to 352 K are reported. These data, together with the dependence of the refractive index and density on temperature, are used in order to investigate the associative behaviour of lauric acid. The Kirkwood correlation factor calculated both with the classical Kirkwood-Fr $\ddot{\rm o}$hlich equation and with that corrected for eflipsoidal shaped molecules are reported and discussed. Both correlation factors obtained indicate the existence of a prevailing antiparallel order of dipole moments. The static permittivity and the correlation factors increase with increasing temperature and this suggests that the number of apolar dimers decreases on going from low to high temperature.

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