Guo, ChengchenLi, ChunmeiVu, HiepHanna, PhilipLechtig, AronQiu, YiminMu, XuanLing, ShengjieNazarian, AraLin, SamuelKaplan, David2022-08-262020-01Guo, Chengchen, Chunmei Li, Hiep Vu, Philip Hanna, Aron Lechtig, Yimin Qiu, Xuan Mu, Shengjie Ling, Ara Nazarian, Samuel Lin, and David Kaplan. "Thermoplastic Moulding of Regenerated Silk." Nature Materials 19, no. 1 (2020): 102-108.1476-1122https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37373064Early insights into the unique structure and properties of native silk suggested that β-sheet nanocrystallites in silk would degrade prior to melting when subjected to thermal processing. Since then, canonical approaches for fabricating silk-based materials typically involve solution-derived processing methods, which have inherent limitations with respect to silk protein solubility, stability in solution, and time and cost efficiency. Here we report a thermal processing method for the direct solid-state molding of regenerated silk into bulk ‘parts’ or devices with tunable mechanical properties. At elevated temperature and pressure, regenerated amorphous silk nanomaterials with ultralow β-sheet content undergo thermal fusion via molecular rearrangement and self-assembly assisted by bound water to form a robust bulk material that retains biocompatibility, degradability and machinability. This transformative technique reverses presumptions about the limitations of direct thermal processing of silk into a wide range of new material formats and composite materials with tailored properties and functionalities.en-USJournal Article2022-08-2610.26434/chemrxiv.8343848.v1