Dynamic light scattering dendrimers

Schematic representations, like those shown in the Scheme 1, are very useful to indicate the chemical composition of the various species and to discuss the interaction between the various building blocks. Furthermore, as one can understand from the representations shown in Figures 9 and 10, the species with high nuclearity exhibit a ttu-ee-dimensional branching structure of the type of those shown by otherwise completely different dendrimers based on organic components. Therefore, endo- and exo-receptor properties can be expected, which are currently under investigation. Furthermore, aggregation of decanuclear complexes has also been demonstrated by dynamic light-scattering and conductivity experiments. Systematic studies on aggregation properties have, however, not been performed yet.

The development of amphiphilic and aggregation behaviour as a fiinction of dendrimer generation of PS-t/enstudied with several diflferent techniques the amphiphilic character at a toluene-water interface was investigated with conductivity measurements, and at a water-air interface with monolayer experiments. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to examine the aggregates formed by the different generations in aqueous solutions, while the critical association concentrations were determined with the pyrene-probe luminescence technique. 

Static and dynamic light scattering studies by Milhem have shown that G4 PAMAM dendrimers do not exhibit intermolecular aggregation in aqueous solution at concentrations up to 7%w/w at pH 10.5, or even when fully unionized at pH 14. 

Table 10.1 Summary of G1-G13 triazine (bold) and PAMAM dendrimers. Ends refers to the number of surface groups, MW is the molecular weight in Daltons, (ixEM and (iors refer to the diameter in nanometers measured by transmission electron microscopy (TEM) and dynamic light scattering (DLS), respectively.

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