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Starlike dendrimers in solutions: Structural properties and internal dynamics.
- Source :
-
Journal of Chemical Physics . 11/28/2006, Vol. 125 Issue 20, p204908. 11p. 2 Diagrams, 1 Chart, 6 Graphs. - Publication Year :
- 2006
-
Abstract
- We measured the shape and the internal dynamics of starlike dendrimers under good solvent conditions with small-angle neutron scattering and neutron spin-echo (NSE) spectroscopy, respectively. Architectural parameters such as the spacer length and generation were varied in a systematic manner. Structural changes occurring in the dendrimers as a function of these parameters are discussed, i.e., in terms of the fractal dimension and deviations of the radius of gyration from the Gaussian value. A first cumulant evaluation of the NSE spectra for each scattering vector q separately yields the length scale dependent relaxation rates. We observe a local minimum in the normalized relaxation rates Ω(q)/q3 on length scales corresponding to the overall dendrimer dimension. The dynamics is discussed within a Rouse-Zimm approach generalized to the case of starlike dendrimers of arbitrary geometry. The model allows an identification of the modes contributing to the relaxation of the dendrimer in the q and time range of the NSE experiment. The local minimum is due to collective breathing motions of (parts of) the dendrons relative to each other. Shape fluctuations are not observed. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00219606
- Volume :
- 125
- Issue :
- 20
- Database :
- Academic Search Index
- Journal :
- Journal of Chemical Physics
- Publication Type :
- Academic Journal
- Accession number :
- 23356626
- Full Text :
- https://doi.org/10.1063/1.2364895