Inhomogeneous aggregates

Illustration Short-time behavior in well mixed systems. Consider the initial evolution of the size distribution of an aggregation process for small deviations from monodisperse initial conditions. Assume, as well, that the system is well-mixed so that spatial inhomogeneities may be ignored. Of particular interest is the growth rate of the average cluster size and how the polydispersity scales with the average cluster size. 

Yao H, Isohashi T, Kimura K (2006) Detection of spectral inhomogeneities of mesoscopic thiacyanine J aggregates in solution by the apparent CD spectral measurement. Chem Phys Lett 419 21-27... 

It was Ziman [77] who has noted that there is little hope, at least at present, to develop an experimental technique permitting the direct measurement of these correlation functions. The only exception are the joint densities x / (r> ) information about which could be learned from the diffraction structural factors of inhomogeneous systems. On the other hand, optical spectroscopy allows estimation of concentrations of such aggregate defects in alkali halide crystals as Fn (n = 1,2,3,4) centres, i.e., n nearest anion vacancies trapped n electrons [80]. That is, we can find x mK m = 1 to 4, but at small r only. Along with the difficulties known in interpretating structure factors of binary equilibrium systems (gases or liquids), obvious specific complications arise for a system of recombining particles in condensed media which, in its turn, are characterized by their own structure factors. 

In conclusion, we should mention that in the description of the behavior of distinct alkoxides it appears very difficult to distinguish the influence of each of the two factors — the inhomogeneity of the molecular composition and the presence of oxoderivatives. In certain cases the reversibility of transformations and reproducibility of the properties of the oligomeric forms can be used as criterion (as for Al(OPr )3) indicating the constant chemical composition and the dominance of the first factor. At the same time, an irreversible aggregation/ polymerization can result from the both factors. 

---