Collect. Czech. Chem. Commun. 1985, 50, 1349-1358

Condensation of supersaturated vapours. Homogeneous nucleation of naphthalene and phthalic anhydride

Jiří Smolík and Jaroslav Vítovec

Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, 165 02 Prague 6-Suchdol


The critical supersaturation required for the homogeneous nucleation of naphthalene and phthalic anhydride from their vapours has been measured using upward thermal diffusion cloud chamber. The results obtained are compared with the predictions of the classical theory of homogeneous nucleation (Volmer-Becker-Doring-Zeldovich) and the corresponding states correlation of homogeneous nucleation. The classical theory is found to be in excellent agreement with the experimental results on naphthalene but overpredicts the critical supersaturation of phthalic anhydride vapours by about 30%. In order to fit the experiment and theory, the new values of surface tension of phthalic anhydride were recalculated from the theory. Critical supersaturation of naphthalene plotted versus temperature reveals the same regular departure from single fluid behaviour as found for alkylbenzenes. The experimental results on phthalic anhydride were found to be in very good agreement with the corresponding states correlation.