Adsorption states energy dependence

A similar interpretation holds for the preexponential factor of the rate constants for the dissociative adsorption, desorption, reaction between the adspecies and their migration. The CM is distinguished by the fact that the preexponential factor is dependent on the properties of the starting reagents only and is independent of the transition state whereas the rate constant depends on the activation barrier height, which is governed by the transition state energy. 

Polymer melt adsorption may be quantified in terms of the lifetime of chain adsorption. Melt adsorption can be regarded as non-existent if each adsorbed chain only spends a duration on a surface that is significantly shorter than its disentanglement relaxation time Td. Sufficient interfacial stress can lower the energy barrier for desorption and shorten the residence time of adsorbed chains on a surface. The chain adsorption state is critically dependent on the surface energy. At present, little is quantitatively known about how the critical interfacial stress for polymer melt desorption varies with the surface energy. 

As mentioned above, the adsorption kinetics for a kinetic-controlled mechanism is given by the balance of surfactant adsorption and desorption fluxes to and from the interface and for the Langmuir kinetics this balance has the form of Eq. (4.15). The rate constants kad and kdes are functions of the activation energies adsorption and desorption and can be specified on the basis of the molecular kinetic [9, 120] or transition state theory [121]. Eq. (4.15) was applied to adsorption kinetics data of surfactants at the water/air interface by many authors, for example in [24, 39, 83, 97, 122, 123, 124, 125, 126, 127]. In these works, it was shown that the values of kad and kdes are not constant hut depend on the surfactant bulk, the degree of adsorption layer saturation, or its lifetime. To obtain better correspondence with the experimental data, some authors had assumed that the adsorption and desorption activation energies depend on the degree of adsorption layer saturation. These rather complicated kinetic equation are more or less empirical, although they transforms into a valid adsorption isotherm at equilibrium... 

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