Three characteristic drop size scales [46]

A drop is an object of an intermediate size: from molecular associates to macrodrops of a new phase. The physical basis for changing concepts, in fact, is absent. The nature of the intermolecular potential acting in the system of molecular associates implies the absence of saturation and, as a consequence, the absence of a limit for the degree of association [40]. When describing the equilibrium drop there is no Laplace equation, which greatly simplifies mathematical analysis. Let us consider the behaviour of the surface tension on the

drop size σ(R). Three characteristic sizes can be distinguished which correspond to: 1) the value of the radius Rb, the greater of which the surface tension values are close to the volume value, with small curvatures of the surface of large drops; 2) the value of the radius Rt above which the thermodynamic description of the surface tension of the drop is justified, when both the discrete nature of the matter and the contributions of spontaneous fluctuations can be neglected; and 3) the critical value R0 of the beginning of the formation of the phase associated with the appearance of the surface tension of the dense phase.