Dendrimers: Difference between revisions
Jump to navigation
Jump to search
Carl McBride (talk | contribs) |
Carl McBride (talk | contribs) |
||
| Line 4: | Line 4: | ||
==Density profile== | ==Density profile== | ||
====Dense shell model==== | ====Dense shell model==== | ||
<ref>[http://dx.doi.org/10.1051/jphyslet:01983004409035100 P. G. de Gennes and H. Hervet "Statistics of «starburst» polymers", Journal de Physique Lettres '''44''' pp. 351-360 (1983)]</ref> | de Gennes and Hervet <ref>[http://dx.doi.org/10.1051/jphyslet:01983004409035100 P. G. de Gennes and H. Hervet "Statistics of «starburst» polymers", Journal de Physique Lettres '''44''' pp. 351-360 (1983)]</ref> 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 | ||
:<math>G_{\mathrm{max}} \approx 2.88 (\ln P + 1.5) </math> | |||
====Dense core model==== | ====Dense core model==== | ||
Most studies support the dense core model of Lescanec and Muthukumar<ref>[http://dx.doi.org/10.1021/ma00210a026 Robert L. Lescanec and M. Muthukumar "Configurational characteristics and scaling behavior of starburst molecules: a computational study", Macromolecules '''23''' pp. 2280-2288 (1990)]</ref> | Most studies support the dense core model of Lescanec and Muthukumar<ref>[http://dx.doi.org/10.1021/ma00210a026 Robert L. Lescanec and M. Muthukumar "Configurational characteristics and scaling behavior of starburst molecules: a computational study", Macromolecules '''23''' pp. 2280-2288 (1990)]</ref> | ||
Revision as of 17:08, 14 November 2013
Dendrimers. Dendrimers can be characterised by three parameters: functionality (), spacer length () and number of generations (). The number of monomers () in a dendrimer is given by
- Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle N=1+fP{\frac {(f-1)^{G+1}-1}{f-2}}}
Density profile
Dense shell model
de Gennes and Hervet [1] 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
- Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle G_{\mathrm {max} }\approx 2.88(\ln P+1.5)}
Dense core model
Most studies support the dense core model of Lescanec and Muthukumar[2] [3] despite early uptake of the dense shell model.
Radius of gyration
It has been suggested that the radius of gyration () scales as [4]
- Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle R_{G}\propto N^{1/3}}
where is the number of monomers.
Ideal dendrimer
For an ideal dendrimer, consisting of non-interacting monomers, is given by [5]
- Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle R_{G\mathrm {ideal} }\propto {\sqrt {PG}}}
Specific dendrimers
- Carbosilane
- PAMAM (also known as STARBURST®)
- PBzE poly(benzyl ether)
- PPI (polypropylenimine)
- Tecto dendrimers
See also
- Star polymers (Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle G=0} )
References
- ↑ P. G. de Gennes and H. Hervet "Statistics of «starburst» polymers", Journal de Physique Lettres 44 pp. 351-360 (1983)
- ↑ Robert L. Lescanec and M. Muthukumar "Configurational characteristics and scaling behavior of starburst molecules: a computational study", Macromolecules 23 pp. 2280-2288 (1990)
- ↑ David Boris and Michael Rubinstein "A Self-Consistent Mean Field Model of a Starburst Dendrimer: Dense Core vs Dense Shell", Macromolecules 29 pp. 7251-7260 (1996)
- ↑ Michael Murat and Gary S. Grest "Molecular Dynamics Study of Dendrimer Molecules in Solvents of Varying Quality", Macromolecules 29 pp.1278–1285 (1996)
- ↑ Wilfried Carl "A Monte Carlo study of model dendrimers", Journal of the Chemical Society, Faraday Transactions 92 pp. 4151-4154 (1996)
- Related reading
- Matthias Ballauff and Christos N. Likos "Dendrimers in Solution: Insight from Theory and Simulation", Angewandte Chemie International Edition 43 pp. 2998-3020 (2004)
- M. R. Wilson, J. M. Ilnytskyi, L. M. Stimson and Z. E. Hughes "Computer simulations of liquid crystal polymers and dendrimers" in Computer Simulations of liquid crystals and polymers, eds. Pasini P., Zannoni C. and Zŭmer S., Kluwer pp. 57-78 (2004) (preprint)
- Mark R. Wilson, Lorna M. Stimson and Jaroslav M. Ilnytskyi "The influence of lateral and terminal substitution on the structure of a liquid crystal dendrimer in nematic solution: A computer simulation study", Liquid Crystals 33 pp. 1167 - 1175 (2006)
- Juan J. Freire "Realistic numerical simulations of dendrimer molecules", Soft Matter 4 pp. 2139-2143 (2008)
- Gustavo Del Río Echenique, Ricardo Rodríguez Schmidt, Juan J. Freire, José G. Hernández Cifre and José García de la Torre "A Multiscale Scheme for the Simulation of Conformational and Solution Properties of Different Dendrimer Molecules", Journal of the American Chemical Society (JACS) 131 pp. 8548-8556 (2009)
- J. M. Ilnytskyi, J. S. Lintuvuori, M. R. Wilson "Simulation of bulk phases formed by polyphilic liquid crystal dendrimers", Condensed Matter Physics 13 pp. 33001:1-16 (2010)