writer：Feng Chen#, Shaoping Lu#, Gengzhi Sun*, Qiang Zhang, Qiang Chen*, et al.
keywords：silk fibrion, double network hydrogels
source：期刊
specific source：JMCB
Issue time：2018年

Regenerated silk fibroin hydrogels (RSF gels) are extensively investigated in the biomedical fields. However, the mechanical properties of RSF hydrogels are often weak or brittle, which greatly limit their applications in high strength demanded fields. Herein, strong and tough RSF-based hydrogels with large extensibility and rapid self-recovery property were developed via double network (DN) concept. RSF/HPAAm DN gels, consisting of physical RSF/SDS gel as the first network and physically cross-linked HPAAm as the second network, are fully physical network structures. At optimal condition, RSF/HPAAm DN gel exhibited integrated high mechanical properties, including high compressive strength (122 MPa), high tensile strength (σf of 1.17 MPa), large extensibility (εf of 19.03 mm/mm), high toughness (W of 11.75 MJ/m3 and T of 1769 J/m2) and rapid self-recovery (61 % toughness recovery after 1 min resting at temperature). Interestingly, owing to contain sodium dodecyl sulfate (SDS) and NaCl, RSF/HPAAm DN gels also displayed ionic conductivity, which could be used as strain sensor, touch screen pen and electronic skin. We believe the design strategy as well as our RSF/HPAAm DN gel will provide a new opinion for achieving high performance RSF-based gels with new functionalities.