Non-Equilibrium Surface Thermodynamics

The equilibrium of the surface, the state without any transport processes, is characterised in the framework of irreversible thermodynamics by the complete absence of fluxes and forces acting at the interface 

Restricted to Defay et al. ( 1977 ) Gibbs surface law for a non-equilibrium state is developed by the basic entropy equation for non-equilibrium processes 

The last term is characteristic of the thermodynamics of irreversible processes. Its magnitude becomes positive if the system s processes are irreversible. Typical irreversible processes are the adsorption or desorption of surfactants at liquid interfaces. The derivative of the second term of Eq. (2C.2), as local entropy production is 

In systems, like adsorption layers, in thermal and mechanical equilibrium the global entropy production is 

A represents the affinity of adsorption of component y from the phase a to the surface, Ap is the affinity of chemical reactions p, 4 are the coordinates of adsorption and reaction, respectively. The significance of other terms was mention above. 

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