Journal Article

FZJ-2016-06902

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Nanoscale Motion of Soft Nanoparticles in Unentangled and Entangled Polymer Matrices

Lungova, M. ; Krutyeva, M.FZJ* ; Pyckhout-Hintzen, W.FZJ* ; Wischnewski, A.FZJ* ; Monkenbusch, M. (Corresponding author)FZJ* ; Allgaier, J.FZJ* ; Ohl, M.FZJ* ; Sharp, M. ; Richter, D.FZJ*

2016
APS College Park, Md.

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Please use a persistent id in citations: http://hdl.handle.net/2128/13062  doi:10.1103/PhysRevLett.117.147803

Abstract: We have studied the motion of polyhedral oligomeric silsesquioxane (POSS) nanoparticles modified with poly(ethylene glycol) (PEG) arms immersed in PEG matrices of different molecular weight. Employing neutron spin echo spectroscopy in combination with pulsed field gradient (PFG) NMR we found the following. (i) For entangled matrices the center of mass mean square displacement (MSD) of the PEG-POSS particles is subdiffusive following a t0.56 power law. (ii) The diffusion coefficient as well as the crossover to Fickian diffusion is independent of the matrix molecular weight and takes place as soon as the center of mass has moved a distance corresponding to the particle radius—this holds also for unentangled hosts. (iii) For the entangled matrices Rubinstein’s scaling theory is validated; however, the numbers indicate that beyond Rouse friction the entanglement constraints appear to strongly increase the effective friction even on the nanoparticle length scale imposing a caveat on the interpretation of microrheological experiments. (iv) The oligomer decorated PEG-POSS particles exhibit the dynamics of a Gaussian star with an internal viscosity that rises with an increase of the host molecular weight.

Keyword(s): Polymers, Soft Nano Particles and Proteins (1st) ; Soft Condensed Matter (2nd) ; Chemistry (2nd)

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS (München) ; Jülich Centre for Neutron Science JCNS (München) ; JCNS-FRM-II)
2. Neutronenstreuung (Neutronenstreuung ; JCNS-1)
3. Neutronenstreuung (ICS-1)
4. Streumethoden (JCNS-2)
5. Streumethoden (PGI-4)
6. JCNS-SNS (JCNS-SNS)

Research Program(s):

1. 524 - Controlling Collective States (POF3-524) (POF3-524)
2. 6212 - Quantum Condensed Matter: Magnetism, Superconductivity (POF3-621) (POF3-621)
3. 6215 - Soft Matter, Health and Life Sciences (POF3-621) (POF3-621)
4. 6G15 - FRM II / MLZ (POF3-6G15) (POF3-6G15)
5. 6G4 - Jülich Centre for Neutron Research (JCNS) (POF3-623) (POF3-623)

Experiment(s):

1. KWS-1: Small angle scattering diffractometer (NL3b)

Appears in the scientific report 2016

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Database coverage:
; ; ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF >= 5 ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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