Dendritic state

Within the context of comparing these three covalent synthesis strategies (i.e. (A), (B) and (C)) we wish to introduce the reader to strategy (C) and the new structural class that constitutes the dendritic state . 

The quest for nanostructures and devices based on the biomimetic premise of architectural and functional precision is intense and remains an ultimate challenge. One must ask - what new options or unique properties does the dendritic state offer to meet the needs of nanoscale science and technology The rest of this chapter will attempt to overview key features of the dendritic state that address these and other issues. 

Parallel studies on PAMAM dendrimers, the Frechet type polyether den-drons, and other dendrimer families have generated an extensive list of unique properties driven by the dendritic state/ Figure 1.18 compares several significant physical property differences between the linear and dendritic topologies related to conformations, crystallinity, solubilities, intrinsic viscosities, entanglement, diffusion/mobility and electronic conductivity. 

Unique features offered by the dendritic state , that have no equivalency in the linear topologies, are found almost exclusively in the dendron/dendrimer subset or to a slightly lesser degree in the dendrigrafts. They include ... 

In summary, the ability to synthesize mathematically predicted megamer structures based on structure controlled dendrimer modules allows new synthesis options that are not presently available with traditional polymer science. In fact, the demonstrated structure control that is possible with the dendritic state raises two important questions ... 

It is hoped the following chapters will inspire and provide some answers to these important questions, as well as further define the role of the dendritic state in the quest for higher, structure controlled, molecular complexity. 

Lee, S. C. 2000. Dendrimers in nanobiological devices, in Tomalia, D. and Frechet, J. M. J. (eds). Dendritic Polymers-A New Macromolecular Architecture Based on the Dendritic State, John Wiley Sons, in press. 

Frechet, J. M. Tomalia, D. A. (2001) Introduction to the dendritic state, in Frechet, J. M. Tomalia, D. A. (Eds.) Dendrimers and other dendritic polymers, Chichester John Wiley and Sons. 

Figure 30.2 Molecular weight dependence of intrinsic viscosity [/ ] for polymers with (a) linear, (b) hyperbranched, (c) dendrimer, and (d) dendrigraft architectures. Source Reproduced with permission from Tomalia DA, Frechet JMJ. Introduction to the dendritic state. In Tomalia DA, Frdchet JMJ, editors. Dendrimers and Other Dendritic Polymers. West Sussex Wiley 2001. p 3 [14]. Copyright 2001 John Wiley and Sons.

Tomalia DA, Frechet JMJ. Introduction to the dendritic state. In Tomalia DA, Frechet JMJ, editors. Dendrimers and Other Dendritic Polymers. West Sussex Wiley 2001. p 3. 

---