Dendrimer Internal Segment Density Distribution SDD

The polydispersity can be fit by two limiting cases namely, as a population of perfect spheres with a range of diameters or as a single randomly oriented 

Therefore, within the PAMAM family, the shapes of dendrimers span the range from stars to spheres. Small G3 dendrimers have a diffuse, open structure while large G10 dendrimers are spheres with a uniform interior, sharp outside transition, and low polydispersity. 

Dendrimer synthesis involves a repetitive building of generations through alternating chemistry steps which approximately double the mass and surface functionality with every generation as discussed earlier [1-4, 18], Random (statistical) hyperbranched polymer synthesis involves the self-condensation of multifunctional monomers, usually in a one-pot single series of covalent formation events [31], Random hyperbranched polymers and dendrimers of comparable molecular mass have the same number of branch points and terminal units, and any application requiring only these two characteristics could be satisfied by either architectural type. Since dendrimer synthesis requires many defined synthetic and process purification steps while hyperbranched synthesis may involve a one-pot synthetic step with no purification, the dendrimers will necessarily be a much more expensive material to produce. 

The results are summarized in Table 11.2. A low generation dendrimer has the shape of a dense star with an interior having a more uniform density than a low generation dendrigraft. As the generation number increases, the shape becomes 

Terminal units Small Linear chains Small 

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