Open AccessUltra strong pyroprotein fibres with long-range ordering
Author(s) -
Se Youn Cho,
Young Soo Yun,
Dawon Jang,
Jun Woo Jeon,
Byung Hoon Kim,
Sungho Lee,
HyoungJoon Jin
Publication year - 2017
Publication title -
nature communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.559
H-Index - 365
ISSN - 2041-1723
DOI - 10.1038/s41467-017-00132-3
Subject(s) - materials science , silk , elongation , composite material , modulus , amorphous solid , carbon fibers , hexagonal crystal system , electrical resistivity and conductivity , ultimate tensile strength , crystallography , composite number , chemistry , electrical engineering , engineering
Silks are protein-based natural structured materials with an unusual combination of high strength and elongation. Their unique microstructural features composed of hard β-sheet crystals aligned within a soft amorphous region lead to the robust properties of silks. Herein we report a large enhancement in the intrinsic properties of silk through the transformation of the basic building blocks into a poly-hexagonal carbon structure by a simple heat treatment with axial stretching. The carbon clusters originating from the β-sheet retain the preferred orientation along the fibre axis, resulting in a long-range-ordered graphitic structure by increasing heat-treatment temperatures and leading improvements in mechanical properties with a maximum strength and modulus up to ∼2.6 and ∼470 GPa, respectively, almost four and thirty times surpassing those of raw silk. Moreover, the formation of sp 2 carbon configurations induce a significant change in the electrical properties (e.g. an electrical conductivity up to 4.37 × 10 3 S cm −1 ).