%0 Journal Article
%T Contrast variation SANS measurement of shell monomer density profiles of smart core-shell microgels
%+ Universität Bielefeld = Bielefeld University
%+ Laboratoire Charles Coulomb (L2C)
%+ Forschungszentrum Jülich GmbH | Centre de recherche de Jülich | Jülich Research Centre (FZJ)
%+ Laboratoire Léon Brillouin (LLB - UMR 12)
%A Cors, Marian
%A Wiehemeier, Lars
%A Wrede, Oliver
%A Feoktystov, Artem
%A Cousin, Fabrice
%A Hellweg, Thomas
%A Oberdisse, Julian
%< avec comité de lecture
%Z L2C:20-035
%@ 1744-683X
%J Soft Matter
%I Royal Society of Chemistry
%V 16
%N 7
%P 1922-1930
%8 2020
%D 2020
%R 10.1039/c9sm02036e
%M 31995091
%Z Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
%Z Chemical Sciences/PolymersJournal articles
%X 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, 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.
%G English
%2 https://hal.science/hal-02566985/document
%2 https://hal.science/hal-02566985/file/Cors_SoftMatter_HAL_Jan2020.pdf
%L hal-02566985
%U https://hal.science/hal-02566985
%~ CEA
%~ CNRS
%~ L2C
%~ DSV
%~ IRAMIS-LLB
%~ CEA-UPSAY
%~ UNIV-PARIS-SACLAY
%~ MIPS
%~ UNIV-MONTPELLIER
%~ CEA-DRF
%~ TEST-HALCNRS
%~ UNIVERSITE-PARIS-SACLAY
%~ GS-ENGINEERING
%~ IRAMIS
%~ GS-CHIMIE
%~ GS-PHYSIQUE
%~ GS-LIFE-SCIENCES-HEALTH
%~ UM-2015-2021