Journal Article

FZJ-2019-05142

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Accelerated Local Dynamics in Matrix-Free Polymer Grafted Nanoparticles

Jhalaria, M. ; Buenning, E. ; Huang, Y. ; Tyagi, M. ; Zorn, R.FZJ* ; Zamponi, M.FZJ* ; García-Sakai, V. ; Jestin, J. ; Benicewicz, B. ; Kumar, S. (Corresponding author)

2019
APS College Park, Md.

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Please use a persistent id in citations: http://hdl.handle.net/2128/23166  doi:10.1103/PhysRevLett.123.158003

Abstract: The tracer diffusion coefficient of six different permanent gases in polymer-grafted nanoparticle (GNP) membranes, i.e., neat GNP constructs with no solvent, show a maximum as a function of the grafted chain length at fixed grafting density. This trend is reproduced for two different NP sizes and three different polymer chemistries. We postulate that nonmonotonic changes in local, segmental friction as a function of graft chain length (at fixed grafting density) must underpin these effects, and use quasielastic neutron scattering to probe the self-motions of polymer chains at the relevant segmental scale (i.e., sampling local friction or viscosity). These data, when interpreted with a jump diffusion model, show that, in addition to the speeding-up in local chain dynamics, the elementary distance over which segments hop is strongly dependent on graft chain length. We therefore conclude that transport modifications in these GNP layers, which are underpinned by a structural transition from a concentrated brush to semidilute polymer brush, are a consequence of both spatial and temporal changes, both of which are likely driven by the lower polymer densities of the GNPs relative to the neat polymer

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

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS-FRM-II)
2. Neutronenstreuung (JCNS-1)
3. Neutronenstreuung (ICS-1)

Research Program(s):

1. 6215 - Soft Matter, Health and Life Sciences (POF3-621) (POF3-621)
2. 6G15 - FRM II / MLZ (POF3-6G15) (POF3-6G15)
3. 6G4 - Jülich Centre for Neutron Research (JCNS) (POF3-623) (POF3-623)

Experiment(s):

1. SPHERES: Backscattering spectrometer (NL6S)

Appears in the scientific report 2019

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; 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 ; Web of Science Core Collection

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