This title appears in the Scientific Report :
2011
Please use the identifier:
http://dx.doi.org/10.1039/C0SM00671H in citations.
Please use the identifier: http://hdl.handle.net/2128/7258 in citations.
pH Responsiveness of Polyelectrolyte Dendrimers: A Dynamical Perspective
pH Responsiveness of Polyelectrolyte Dendrimers: A Dynamical Perspective
A combined quasi-elastic neutron scattering (QENS) and high-resolution solution NMR spectroscopy study was conducted to investigate the internal dynamics of aqueous (D2O) G5 PAMAM dendrimer solutions as a function of molecular protonation at room temperature. Localized motion of the dendrimer segmen...
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Personal Name(s): | Li, X. |
---|---|
Zamponi, M. / Hong, K. / Porcar, L. / Shew, C.-Y. / Jenkins, T. / Liu, E. / Smith, G.S. / Herwig, K.W. / Liu, Y. / Chen, W.-R. | |
Contributing Institute: |
JCNS; JCNS Neutronenstreuung; ICS-1 Streumethoden; PGI-4 |
Published in: | Soft matter, 7 (2011) S. 618 - 622 |
Imprint: |
Cambridge
Royal Society of Chemistry (RSC)
2011
|
Physical Description: |
618 - 622 |
DOI: |
10.1039/C0SM00671H |
Document Type: |
Journal Article |
Research Program: |
Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) BioSoft: Makromolekulare Systeme und biologische Informationsverarbeitung |
Series Title: |
Soft Matter
7 |
Subject (ZB): | |
Link: |
Get full text Published under German "Allianz" Licensing conditions on 2010-11-23. Available in OpenAccess from 2011-11-23 |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/7258 in citations.
A combined quasi-elastic neutron scattering (QENS) and high-resolution solution NMR spectroscopy study was conducted to investigate the internal dynamics of aqueous (D2O) G5 PAMAM dendrimer solutions as a function of molecular protonation at room temperature. Localized motion of the dendrimer segments was clearly exhibited in the QENS data analysis while the global, center-of-mass translational diffusion was measured by NMR. Our results unambiguously demonstrate an increased rapidity in local scale (similar to 3 angstrom) motion upon increasing the molecular protonation. This is contrary to an intuitive picture that increased charge stiffens the dendrimer segments thereby inhibiting local motion. These charge-induced changes may be a result of interactions with the surrounding counterions and water molecules as the segments explore additional intra-dendrimer volume made available by slight electrostatic swelling and redistribution of mass in the dendrimer interior. This observation is relevant to development of a microscopic picture of dendrimer-based packages as guest-molecule delivery vehicles because reorganization of the confining dendrimer segments must be a precursor to guest-molecule release. |