Experimental determination of the surface energy of critical nuclei duringthe nucleation of supersaturated vapor

Theoretical substantiation of the empirical method for determining the surf ace (or excess) energy of critical nuclei was performed within the framewor k of thermodynamic approach. Characteristics of critical nuclei were determ ined based on the studies of the nucleation of supersaturated vapors of gly cerol in the vicinity of its melting point and the critical temperature of carrier gas. The effect of the specific features of physicochemical paramet ers of the studied substance and carrier gas on the parameters of critical nuclei was revealed. Experimental values of the surface energy of critical nuclei were compared with those calculated by the droplet model. The necess ity for the allowance for the temperature dependence of the surface energy of critical nuclei was demonstrated. It was noted that the largest deviatio n from the predictions of droplet model arises at small (about 10) numbers of molecules in a critical nucleus; as the size of a nucleus increases, the surface energy, in the limiting ease, tends to physically correct value.