Expanding the Non-Yielding Region of Tough and Strong Hydrogels

在过去的一年里，我们结合小角X射线散射（SAXS）和力学方法来研究坚韧且不屈服的水凝胶的结构变化。通过小角X射线散射，我们得到了50纳米尺度下的网络形变。我们发现，凝胶的纳米级变形是仿射的宏观变形块体凝胶。通过力学化学方法证实了形变过程中不发生断链，并进行了循环加载，考察了形变过程中能量的消耗情况。此外，我们检查了超连通性对网络变形的作用。我们目前的研究结果表明，超连通性和两个网络之间的应力转移的相互作用是重要的非仿射变形。

In the past year, we combined the small-angle X-ray scattering (SAXS) and the mechanical method to study the structure change of the tough and non-yielding hydrogels. Through SAXS, we obtained the network deformation in the scale of 50 nanometers. We found that the nanoscale deformaiton of gel is affine to the macroscopic deformation of bulk gel. Through mechanical chemistry method, we confirmed that the chain scission does not occur during deformation.We performed cyclic loading to check how energy dissipates during deformation. In addition, we checked the role of hyperconnectivity on the network deformation. Our current results suggest that the interplay between hyperconnectivity and stress transfer between two networks is important to the nonaffine deformation.