Transport of energy

We can relate the heat of transport and energy of transport by using the relation... 

Finally, in classical nucleation theory there are additional terms in the equation for v, notably a second exponential term for the activation energy of transporting a molecule across the phase boundary. It is the inverse dependence of AG on AT2 that is the most strongly varying quantity and determines the nucleation rate, however, so in the interests of simplicity we ignore the other terms (for now). 

InEq. (21)AE is the activation energy of transport process, calculated by Eq. (22) ... 

U activation energy of transport process R universal gas constant T temperature T glass transition temperature... 

Qa and Xv.p are the heat of adsorption and the latent heat of vaporization, and and E,i are the activation energies of transport at the first layer and at the second and above layers. E,i is determined from temperature dependency of liquid viscosity of adsorbate and Em is considered to be proportional to as discussed in 4.3.3. Further, this model was extended to the ease of heterogeneous surface, where energy distribution function is involved. Comparison of the model and the data on vycor glass is shown in Fig. 4.7. 

Solvent Type. Nearly every macrocycle-mediated membrane system devised to date involves the solvation of macrocycles in an organic solvent. Because transport of any substance requires that it pass through this organic solvent, transport rates and selectivities depend heavily upon the properties of this solvent. In an earlier review (27) we divided the free energy of transport, AGt, into four components in a thermodynamic cycle as follows ... 

Activation energies of transport in organic polymers, including molecularly doped ones below Tg (assuming the process is simply thermally activated), are typically 0.2-0.7eV, and decrease with increasing electric field. At T>Tg the activation energies are typically smaller than below Tg. This behaviour is similar in detail to that already reported for glassy selenium [31]. 

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