Meng Xiaohui, Qiao Yan, Do Changwoo, Bras Wim, He Chunyong, Ke Yubin, Russell Thomas P, Qiu Dong
Beijing National Laboratory for Molecular Sciences (BNLMS), Laboratory of Polymer Physics and Chemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Adv Mater. 2022 Feb;34(7):e2108243. doi: 10.1002/adma.202108243. Epub 2022 Jan 2.
The elastic storage and release of mechanical energy has been key to many developments throughout the history of mankind. Resilience, absent hysteresis, has been an elusive goal to achieve, particularly at large deformations. Using a low-crosslink-density polyacrylamide hydrogel at 96% water content having hyperbranched silica nanoparticles (HBSPs) as the major junction points, a hysteresis-free material is realized. The fatigue-free characteristic of these composite hydrogels is evidenced by the invariance of the stress-strain curves at strain ratios of 4, even after 5000 cycles. At a strain ratio of 7, only a 1.3% hysteresis is observed. A markedly increased strain-ratio-at-break of 11.5 is observed. The unique attributes of these resilient hydrogels are manifested in the high-fidelity detection of dynamic deformations under cyclic loading over a broad range of frequencies, difficult to achieve with other materials.
机械能的弹性存储和释放一直是人类历史上许多发展的关键。无滞后的弹性一直是一个难以实现的目标，尤其是在大变形情况下。通过使用一种水含量为96%、以超支化二氧化硅纳米颗粒（HBSPs）作为主要交联点的低交联密度聚丙烯酰胺水凝胶，实现了一种无滞后材料。这些复合水凝胶的无疲劳特性通过在应变比为4时应力-应变曲线不变得到证明，即使在5000次循环后也是如此。在应变比为7时，仅观察到1.3%的滞后。观察到断裂应变比显著增加至11.5。这些弹性水凝胶的独特属性体现在能够在广泛的频率范围内对循环加载下的动态变形进行高保真检测，这是其他材料难以实现的。
