Journal Article

FZJ-2015-03381

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Free volume in PEP-silica nanocomposites with varying molecular weight

Ohrt, C. (Corresponding Author) ; Koschine, T. ; Rätzke, K. ; Faupel, F. ; Willner, L.FZJ* ; Schneider, G. J.FZJ*

2014
Elsevier Science Oxford

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Please use a persistent id in citations: doi:10.1016/j.polymer.2013.11.021

Abstract: The influence of confinement in polymer-nanocomposites on free volume and glass transition of the polymer chains was studied. The molecular weight (Mw) of poly(ethylene-alt-propylene) (PEP) was varied from 3k to 200k and so the end-to end distance of the chains at fixed diameter (∼15 nm) and concentration (15%) of the silica nanoparticles increased. Thus the topological confinement increases with increasing Mw. Using hydrophobic PEP and particles functionalized with short organic molecules, we can rule out contributions of permanent adsorption of the chains. DSC showed no change in glass transition temperature. The decrease in the specific heat capacity could be explained by a simple mixing rule. By positron annihilation lifetime spectroscopy, taking properly into account contributions of the silica particles, we rule out an influence of the geometrical confinement on the free volume in the PEP nanocomposites studied here.

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 (München) ; Jülich Centre for Neutron Science JCNS (München) ; JCNS-FRM-II)
2. Neutronenstreuung (Neutronenstreuung ; JCNS-1)

Research Program(s):

1. 54G - JCNS (POF2-54G24) (POF2-54G24)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2015

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Database coverage:
; Current Contents - Physical, Chemical and Earth Sciences ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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