Colloidal gelation induced by ring polymers

Esmaeel Moghimi, Iurii Chubak, Maria Kaliva, Parvin Kiany, Taihyun Chang, Junyoung Ahn, Nikolaos Patelis, Georgios Sakellariou, Sergei A. Egorov, Dimitris Vlassopoulos, Christos N. Likos

Veröffentlichungen: Beitrag in FachzeitschriftArtikelPeer Reviewed

Abstract

We provide unambiguous experimental evidence that ring polymers are stronger depleting agents in colloidal suspensions than their linear counterparts. We use an intermediate volume fraction (φc=0.44) colloidal gel based on the classic poly(methyl methacrylate) (PMMA) hard spheres, in which the polystyrene depletant is either linear or ring of the same molar mass or the same size. We systematically increase the depletant concentration from zero (no attraction) to well above the gelation point and find that in the presence of rings, gels are formed at smaller concentrations and possess a larger storage modulus in comparison to those induced by the linear chains. Consequently, the yield stress is enhanced; however, the yield strain (gel deformability) remains concomitantly unaffected. Our experimental findings are in agreement with theoretical calculations based on effective interaction potentials. Hence, polymer architecture is a powerful entropic tool to tailor the strength of colloidal gels.
OriginalspracheEnglisch
Aufsatznummer013079
Seitenumfang13
FachzeitschriftPhysical Review Research
Jahrgang6
Ausgabenummer1
DOIs
PublikationsstatusVeröffentlicht - Jan. 2024

ÖFOS 2012

  • 103023 Polymerphysik
  • 104017 Physikalische Chemie

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