Nucleation from supersaturated water vapour on immiscible liquid substrates: Effect of the macroscopic geometry of the three-phase system on the critical supersaturation and the line tension

Abstract

Nucleation from supersaturated water vapour on different liquid substrates ( n-hexadecane, decalin, 2-bromotoluene and tetrachloroethylene) has been studied experimentally by the reverse Wilson chamber method in order to obtain the dependence of the critical supersaturation on the macroscopic geometry of the three-phase system. The experimental results are interpreted on the basis of the classical theory of heterogeneous nucleation as well as in the framework of the theory of barrierless heterogeneous nucleation. The discrepancy between the measured critical supersaturations and those predicted by the classical theory is explained by the effect of a negative line tension of the three-phase contact line. The influence of the macroscopic geometry on the line tension has been investigated.