Journal Article

FZJ-2020-00692

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Contrast variation SANS measurement of shell monomer density profiles of smart core–shell microgels

Cors, M. ; Wiehemeier, L. ; Wrede, O. ; Feoktystov, A.FZJ* ; Cousin, F. ; Hellweg, T. (Corresponding author) ; Oberdisse, J. (Corresponding author)

2020
Royal Soc. of Chemistry London

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Please use a persistent id in citations: http://hdl.handle.net/2128/24427  doi:10.1039/C9SM02036E

Abstract: The radial density profile of deuterated poly(N,n-propyl acrylamide) shell monomers within core–shell microgels has been studied by small-angle neutron scattering in order to shed light on the origin of their linear thermally-induced swelling. The poly(N-isopropyl methacrylamide) core monomers have been contrast-matched by the H2O/D2O solvent mixture, and the intensity thus provides a direct measurement of the spatial distribution of the shell monomers. Straightforward modelling shows that their structure does not correspond to the expected picture of a well-defined external shell. A multi-shell model solved by a reverse Monte Carlo approach is then applied to extract the monomer density as a function of temperature and of the core crosslinking. It is found that most shell monomers fill the core at high temperatures approaching synthesis conditions of collapsed particles, forming only a dilute corona. As the core monomers tend to swell at lower temperatures, a skeleton of insoluble shell monomers hinders swelling, inducing the progressive linear thermoresponse.

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

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS-FRM-II)
2. Streumethoden (JCNS-2)
3. Heinz Maier-Leibnitz Zentrum (MLZ)

Research Program(s):

1. 6G4 - Jülich Centre for Neutron Research (JCNS) (POF3-623) (POF3-623)
2. 6G15 - FRM II / MLZ (POF3-6G15) (POF3-6G15)

Experiment(s):

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

Appears in the scientific report 2020

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Database coverage:
; ; Allianz-Lizenz / DFG ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; IF < 5 ; JCR ; National-Konsortium ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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