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  • Focus Review
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A benchmark for gel structures: bond percolation enables the fabrication of extremely homogeneous gels

Abstract

Gels are soft-elastic materials consisting of a three-dimensional crosslinked polymer network and liquid filling the space between this network. Numerous gels with unique physical properties have been synthesized and are widely used in our daily lives. However, all of these gels contain a substantial level of structural defects, as detected by scattering measurements. Despite the tremendous efforts made in recent decades to remove imperfections from gels, discernible signs of spatial defects have been persistently observed in gels. Researchers believe that gels are inherently heterogeneous. In this focus review, I briefly introduce a recent finding from our research group’s efforts to fabricate polymer gels free of spatial heterogeneities. The commonly observed scattering profiles for the spatial defects disappeared in the homogeneous gels. The newly observed scattering profiles are a benchmark for gel structures.

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Acknowledgements

The author would like to express his gratitude to all his colleagues for their valuable contributions to this focus review. The author is deeply indebted to Prof. Mitsuhiro Shibayama (Comprehensive Research Organization for Science and Society) and Prof. Takamasa Sakai (University of Tokyo) for their continuous encouragement and constructive discussions. This research was supported by JSPS KAKENHI grants JP17K14536 and JP19K15628, Eno Scientific Foundation, the University of Tokyo Gap Fund Program, and the Japan Science and Technology Agency (JST) to T.S. (CREST Grant JPMJCR1992).

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Li, X. A benchmark for gel structures: bond percolation enables the fabrication of extremely homogeneous gels. Polym J 53, 765–777 (2021). https://doi.org/10.1038/s41428-021-00479-x

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