Scale-Matched Nanoscale Confinement Governs Chain Cooperativity and Fatigue Resistance in Soft Hydrogels.

Chen, Yumeng; Huo, Huanxin; Yang, Hongxing; Li, Hongshan; Gao, Yihong; Duan, Xin; Du, Guanben; Yang, Long · Nano Lett · 2026

basic_science · Level V

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Abstract

Despite the presence of abundant reversible interactions in single-network hydrogels, they still frequently fail under cyclic loading. This limitation originates from the mismatch between the nanoscale anchoring distance d and the polymer correlation length ξ. As d/ξ approaches unity, nanoscale anchors cooperatively recruit previously dormant chains, suppress mesoscale heterogeneity, and enable reversible hydrogen bonding and π-π interactions to mediate efficient cyclic load transfer. Hydrogels tuned to this length-scale-matched regime exhibit an adhesion strength of 30 kPa, a fracture strain of 5000%, and an ultrahigh toughness of 5775 kJ m<sup>-3</sup>, while maintaining low hysteresis and excellent fatigue stability. These results demonstrate the existence of a measurable and transferable nanoscale control parameter for designing fatigue-resistant soft networks.