Eyring’s rate theory

Based on the Nernst-Planck flux equation and Eyring s rate theory, a simple theoretical model was evolved for the description of the transport of ions through thick carrier membranes5 (see also Ref. 15). The primary... 

Laidler, K.J. and Tweedale, A. (1971) Current status of Eyring s rate theory. Adv. Chem. Phys., 21, 113. 

The model of Cao et al. [26] is based on Eyring s rate theory, and has then been formulated [27] in such a way that one obtains a group contribution viscosity model for mixtures based on the UNIFAC prediction method for activity coefficients. Their expression for the dynamic viscosity of a pure liquid is ... 

As shown earlier, for the viscosity of two-component systems there are two ways to derive the viscosity equation. One approach is to use Eq. (30), directly correlating the viscosity to the free volume of the dispersed phase on the basis of Eyring s rate theory Another approach is to use Eq. (48), assuming that the viscosity is proportional to the -n power of the free volume on the basis of Einstein s equation,... 

The viscosity equation derived from Eyring s rate theory 3.1.2.1.1. Theta condition... 

On the basis of Eyring s rate theory, an expression similar to Zurkov s equation can be derived as... 

According to Blake Haynes (1969), wetting is a stress modified molecular rate process described by Eyring s classical theory. They assume a displacement of molecules within the three-phase zone. Activation energies for viscous flows play a determining role in the theories... 

The adhesion theories of rubber friction fall into two main groups - molecular and macroscopic. The molecular theories are associated with the names of Schallamach , Bartenev >, and Rieger, and have much in common. The basic idea is that bonds are formed at the interface, strained and then broken, and one form or another of Eyring s rate-process theory is applied. In effect one finds that the theories end with two main factors multiplied together. 

Figure 4.9 illustrates the sequential process of nucle-ation, which shows AG(N) against N. AG (A ) corresponds to critical nano-nucleation. In the nucleation theory, the so-called net flow of nucleation (j) plays an important role in the nucleation process as illustrated in Figure 4.9 (also see Section 4.4). As the zero-th approximation, critical nano-nucleation should become the main controlling process with an activation barrier in nucleation following Eyring s kinetic theory of absolute reaction rate (theory of absolute reaction rate) [30]. Hence,y can be given by... 

Glasstone, S., K.J. Leidler and H. Eyring, 1941, The Theory of Rate Processes (McGraw-Hill, New York). 

Glasstone, S. Laidler, K.J. Eyring, H. The Theory of Rate Processes McGraw-Hill New York, 1948 pp 472-3. 

Several attempts to relate the rate for bond scission (kc) with the molecular stress ( jr) have been reported over the years, most of them could be formally traced back to de Boer s model of a stressed bond [92] and Eyring s formulation of the transition state theory [94]. Yew and Davidson [99], in their shearing experiment with DNA, considered the hydrodynamic drag contribution to the tensile force exerted on the bond when the reactant molecule enters the activated state. If this force is exerted along the reaction coordinate over a distance 81, the activation energy for bond dissociation would be reduced by the amount ... 

Various statistical treatments of reaction kinetics provide a physical picture for the underlying molecular basis for Arrhenius temperature dependence. One of the most common approaches is Eyring transition state theory, which postulates a thermal equilibrium between reactants and the transition state. Applying statistical mechanical methods to this equilibrium and to the inherent rate of activated molecules transiting the barrier leads to the Eyring equation (Eq. 10.3), where k is the Boltzmann constant, h is the Planck s constant, and AG is the relative free energy of the transition state [note Eq. (10.3) ignores a transmission factor, which is normally 1, in the preexponential term]. 

The transition state theory provides a useful framework for correlating kinetic data and for codifying useful generalizations about the dynamic behavior of chemical systems. This theory is also known as the activated complex theory, the theory of absolute reaction rates, and Eyring s theory. This section introduces chemical engineers to the terminology, the basic aspects, and the limitations of the theory. 

Glasstone, S., Laidler, K. J., and Eyring, H. (1941), Theory of Rate Processes, McGraw Hill, New York. Langevin, M. P. (1905), J. Chim. Phys. 5, 245. English translation in McDaniel, E. W. (1964), Collision Phenomena in Ionized Gases, app. 1, Wiley, New York. 

Although the formulation of such a theory has never been achieved, Eyring s absolute reaction rate model [123] has several features in common with such theory. 

According to Eyring s reaction-rate theory,90 the elementary bimolecular chemical reaction between reactant species A and B proceeds through a transition-state... 

The Marcus classical free energy of activation is AG , the adiabatic preexponential factor A may be taken from Eyring s Transition State Theory as (kg T /h), and Kel is a dimensionless transmission coefficient (0 < k l < 1) which includes the entire efiFect of electronic interactions between the donor and acceptor, and which becomes crucial at long range. With Kel set to unity the rate expression has only nuclear factors and in particular the inner sphere and outer sphere reorganization energies mentioned in the introduction are dominant parameters controlling AG and hence the rate. It is assumed here that the rate constant may be taken as a unimolecular rate constant, and if needed the associated bimolecular rate constant may be constructed by incorporation of diffusional processes as ... 

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