Poly(N-isopropylacrylamide) microgel swelling behavior and suspension structure studied with small-angle neutron scattering.
Phys Rev E
; 108(5-1): 054604, 2023 Nov.
Article
in En
| MEDLINE
| ID: mdl-38115405
ABSTRACT
Microgels are of high interest for applications and as model systems due to their volume response to external stimuli. We use small-angle neutron scattering to measure the form and structure factors of poly(N-isopropylacrylamide) microgels in dilute and concentrated suspensions and find that microgels keep a constant size up to a concentration, above which they deswell. This happens before random-close packing. We emphasize suspension polydispersity must be considered to obtain accurate form and structure factors. Our results are compatible with microgel deswelling triggered by the osmotic pressure set by counterions associated to charged groups in the microgel periphery, which sharply increases when the counterion clouds surrounding the microgels percolate throughout the suspension volume.
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Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Phys Rev E
/
Phys. rev., E (Online)
/
Physical review. E (Online)
Year:
2023
Document type:
Article
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