Heterogeneous solubilization

The above results suggest that in general, the chemical behavior of probe molecules in highly ordered liquid crystalline phases such as this one may be governed by rather complex, heterogeneous solubilization effects. The manifestation of this in individual systems will depend primarily on solubility factors. The behavior of 8 in the smectic phase of CCH-2 is likely to be related to that in CCH-4, but a more exhaustive study of these systems has yet to be carried out. 

A comprehensive model for heterogeneous solubilization was also developed by Naik and Doraiswamy (1997), which accounts for ion exchange in the solid phase, interphase transport of the quat species, and the organic reaction. In this case, ion exchange taking place in the solid phase can be one of the rate controlling steps, since access to the anions in... 

Figure 11. Effect of solid phase mass-transfer limitations in heterogeneous solubilization.

In the analysis of heterogeneous solubilization, the role of the solid-phase reaction in influencing the overall reaction is different from that for the usual gas-solid catalytic reaction. The most important situation is that the film and internal diffusion effects within the solid and at the solid-liquid interface are significant. 

In dealing with SLPTC, two types of mechanisms must be recognized, homogeneous and heterogeneous solubilization. We present the outlines of a reasonably rigorous model for each. 

Figure 19.4 Mechanisms of SLPTC action homogeneous and heterogeneous solubilization...

Reaction model based on heterogeneous solubilization (accounting for reaction within the solid)... 

Figure 16.7 Model schematic for heterogeneous solubilization. (Adapted from Naik, S.D. and Doraiswamy, L.K., AlChE J., 44, 612, 1998.)...

---