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Phase Separation Behavior in Tough and Self-Healing Polyampholyte Hydrogels
Title: | Phase Separation Behavior in Tough and Self-Healing Polyampholyte Hydrogels |
Authors: | Cui, Kunpeng Browse this author | Ye, Ya Nan Browse this author | Sun, Tao Lin Browse this author | Yu, Chengtao Browse this author | Li, Xueyu Browse this author | Kurokawa, Takayuki Browse this author | Gong, Jian Ping Browse this author →KAKEN DB |
Issue Date: | 14-Jul-2020 |
Publisher: | American Chemical Society(ACS) |
Journal Title: | Macromolecules |
Volume: | 53 |
Issue: | 13 |
Start Page: | 5116 |
End Page: | 5126 |
Publisher DOI: | 10.1021/acs.macromol.0c00577 |
Abstract: | Polyampholyte hydrogels (PA gels) are drawing great attention for their excellent mechanical properties including self-healing, high toughness, and fatigue resistance. These mechanical performances are found to be attributed to the hierarchical structure of the PA gels, consisting of reversible ionic bonds at the 1 nm scale, permanent polymer network at the 10 nm scale, and icontinuous phase network at the 100 nm scale. In this work, we systematically studied the phase network formation of these gels aiming to answer the following three questions: (1) how the phase separation occurs? (2) what determines the phase structure? and (3) is this structure in thermodynamic equilibrium or not? Our results show that the phase separation occurs during dialysis of counterions from the gels and it is driven by the Coulombic and hydrophobic interactions. The phase size d0 and the number of aggregated chains in a unit cell of the phase structure n scale with the molecular weight of the partial chain between permanent effective cross-linking Meff as d0 ∼ Meff and n ∼ Meff 2, respectively. A chemical cross-linker and topological entanglement suppress phase separation, while hydrophobic interaction favors phase separation. An intrinsic correlation between the polymer density difference (Δρ) between two phases and d0 is observed (Δρ ∼ d02) as a result of the competition between the driving force to induce phase separation and the resistance to suppress the phase separation. The phase-separated structure is metastable, which is locally trapped by strong intermolecular interactions. |
Rights: | This document is the Accepted Manuscript version of a Published Work that appeared in final form in Macromolecules, copyright ©2020 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.macromol.0c00577. |
Type: | article (author version) |
URI: | http://hdl.handle.net/2115/82220 |
Appears in Collections: | 生命科学院・先端生命科学研究院 (Graduate School of Life Science / Faculty of Advanced Life Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 龔 剣萍 (Gong Jian Ping)
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