首页|Interplay between Microscopic Structures and Macroscopic Viscoelastic Properties of Polyampholyte Gels

Interplay between Microscopic Structures and Macroscopic Viscoelastic Properties of Polyampholyte Gels

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Polyampholyte gels,which have hierarchical structures,exhibit excellent self-healing properties and have great promise for biomateri-als and bioengineering.We investigated the relationship between microscopic structures and macroscopic viscoelastic properties of polyam-pholyte gels and found three factors influencing their viscoelastic properties,including the chemical crosslinking bonds,topological entangle-ments controlled by monomer concentration,and the ionic bonds.Ionic strength plays a major role on the strength of ionic bonds.A crossover point of elastic modulus and loss modulus was observed in the dynamic frequency sweeps at low monomer concentration or low chemical crosslinking density for gels with intermediate strength of ionic bonds.The solid-liquid transition signaled by the crossover point is a typical fea-ture of dynamic associated gels,representing the dynamical association-dissociation of the ionic bonds and full relaxation of the topological en-tanglements in the gel network.While the crossover point disappears when the ionic bonds are too weak or too strong to form"permanent"bonds.Consistently,in the non-linear yielding measurement,gels with intermediate strength of the ionic bonds are ductile and yield at very large shear strain due to the self-healing properties and the dynamic association-dissociation of the ionic bonds.But the self-healing properties disap-pear when the ionic bond strength is too weak or too strong.Our work reveals the mechanism of how the dynamic association-dissociation of ionic bonds influences both the linear and non-linear viscoelastic properties of the polyampholyte gels.

Polyampholyte gelIonic bondTopological entanglementSelf-healingHierarchical structure

You-Cai Xue、Yi-Ming Yang、Di Jia

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Beijing National Laboratory for Molecular Sciences,Laboratory of Polymer Physics and Chemistry,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China

University of Chinese Academy of Sciences,Beijing 100049,China

National Natural Science Foundation of ChinaNational Key R&D Program of ChinaNational Key R&D Program of ChinaInternational Partnership Program of the Chinese Academy of Sciences

222731142023YFE01245002023YFC2411203027GJHZ2022061FN

2024

高分子科学(英文版)
中国化学会 中国科学院化学研究所

高分子科学(英文版)

CSTPCD
影响因子:0.721
ISSN:0256-7679
年,卷(期):2024.42(9)