Dendrimers

From SklogWiki
Jump to navigation Jump to search
A single dendrimer molecule (G4 PAMAM, solvent not shown)

Dendrimers (from the aincient greek δένδρον, meaning tree [1]). Dendrimers can be characterised by three parameters: functionality (), spacer length () and number of generations (). The number of monomers () in a dendrimer is given by

Density profile[edit]

Dense shell model[edit]

de Gennes and Hervet [2] calculated that for self-avoiding dendrimers in a good solvent, the density profile increases from a minimum at the centre of the dendrimer to a maximum at its outer surface, i.e. a dense outer shell with a hollow centre. Note this leads to a limit of

However, recent work by Zook and Pickett [3] has shown that the de Gennes and Hervet model was flawed.

Dense core model[edit]

Most studies support the dense core model of Lescanec and Muthukumar[4] despite early uptake of the dense shell model. Boris and Rubinstein pointed out that the structure of the dendrimer is a result of the competition between the entropy and excluded volume [5], neither of which terms favouring a hollow centre.

Radius of gyration[edit]

It has been suggested that the radius of gyration () scales as [6]

where is the number of monomers. This implies a compact structure.

Ideal dendrimer[edit]

For an ideal dendrimer, consisting of non-interacting monomers, is given by [7]


Chen-Cui scaling law[edit]

The Chen-Cui scaling law is given by [8]:


where is the Flory exponent.

Specific dendrimers[edit]

See also[edit]

References[edit]

Related reading