Impact‐Resistant Hydrogels by Harnessing 2D Hierarchical Structures
Xiangyu Liang, Guangda Chen, Iek Man Lei, Pei Zhang, Zeyu Wang, Xingmei Chen, Mengze Lu, Jiajun Zhang, Zongbao Wang, Taolin Sun, Yang Lan, Ji Liu
Abstract
Abstract With the strengthening capacity through harnessing multi‐length‐scale structural hierarchy, synthetic hydrogels hold tremendous promise as a low‐cost and abundant material for applications demanding unprecedented mechanical robustness. However, integrating high impact resistance and high water content, yet superior softness, in a single hydrogel material still remains a grand challenge. Here, a simple, yet effective, strategy involving bidirectional freeze‐casting and compression‐annealing is reported, leading to a hierarchically structured hydrogel material. Rational engineering of the distinct 2D lamellar structures, well‐defined nanocrystalline domains and robust interfacial interaction among the lamellae, synergistically contributes to a record‐high ballistic energy absorption capability (i.e., 2.1 kJ m −1 ), without sacrificing their high water content (i.e., 85 wt%) and superior softness. Together with its low‐cost and extraordinary energy dissipation capacity, the hydrogel materials present a durable alternative to conventional hydrogel materials for armor‐like protection circumstances.