Effect of particle size on vapour pressure

In this first example, a single-component system consisting of a liquid and a gas phase is considered. If the surface between the two phases is curved, the equilibrium conditions will depart from the situation for a flat surface used in most equilibrium calculations. At equilibrium the chemical potentials in both phases are equal  

Here Vs and V1 are the molar volume of the two phases, but the subscript m is not used for simplicity. The pressure of the two phases is related by the Laplace equation (6.27), which for a spherical liquid droplet surrounded by its own vapour becomes, in differential form, 

If the pressure dependence of the molar volume of the liquid is neglected, integration from a flat interface (r = oo) yields 

A consequence of the decreasing vapour pressure with increasing size of the droplet is that in a distribution of droplets the larger droplets will grow at the expense of the smaller ones a fact that will be discussed more thoroughly below. 

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