Boiling of superheated liquids near the spinodal: I General theory

Boiling of extremely superheated liquids will be discussed as critical phen omenon. A consistent description including the kinetics of the phase transi tion can be deduced from a variational principle. In contrast to classical nucleation theory, the spatial extension of critical nuclei increases with increasing superheating, but the energy needed to form a vapour nucleus dec reases and vanishes at the spinodal. The boiling process exhibits an equiva lence to a phase transition of second order and the appearing critical indi ces obey the corresponding scaling laws.