Operando Decoding Ion‐Conductive Switch in Stimuli‐Responsive Hydrogel by Nanodiamond‐Based Quantum Sensing

Autor: Ruqiang Dou, Zan Li, Guoli Zhu, Chao Lin, Frank X. Liu, Biao Wang
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Advanced Science, Vol 11, Iss 43, Pp n/a-n/a (2024)
Druh dokumentu: article
ISSN: 2198-3844
20240694
DOI: 10.1002/advs.202406944
Popis: Abstract Thermal‐responsive hydrogels are developed as ion‐conductive switchs for energy storage devices, however, the molecule mechanism of switch on/off remains unclear. Here, poly(N‐isopropylacrylamide‐co‐acrylamide) hydrogel is synthesized as a model material and nanodiamond (ND) based quantum sensing for phase change study is developed. First, micro‐scale phase separation with cross‐linked mesh structure after sol‐gel transition is visualized in situ and water molecules are trapped by polymer chains and on a chemically “frozen” state. Then, the nano‐scale inhomogeneous distributions of viscosity, thermal conductivity and ionic mobility in hydrogel at high temperature are observed by measuring the rotation, translation and zero‐field splitting of NDs. Besides, the ionic mobility of hydrogel is found to be dependent not only on temperature but also on polymer concentration. These observations suggested that the physical “wall” induced by inhomogeneous phase separation at microscopic scale blocked the ion conduction pathways, providing a potential intrinsic explanation for ion migration shut‐down of ionic hydrogels at high temperature.
Databáze: Directory of Open Access Journals
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