title: Multiscale deformations lead to high toughness and circularly polarized emission in helical nacre-like fibres.
abstract: Nacre-like composites have been investigated typically in the form of coatings or free-standing sheets. They demonstrated remarkable mechanical properties and are used as ultrastrong materials but macroscale fibres with nacre-like organization can improve mechanical properties even further. The fiber form or nacre can, simplify manufacturing and offer new functional properties unknown yet for other forms of biomimetic materials. Here we demonstrate that nacre-like fibres can be produced by shear-induced self-assembly of nanoplatelets. The synergy between two structural motifs--nanoscale brick-and-mortar stacking of platelets and microscale twisting of the fibres--gives rise to high stretchability (>400%) and gravimetric toughness (640 J g(-1)). These unique mechanical properties originate from the multiscale deformation regime involving solid-state self-organization processes that lead to efficient energy dissipation. Incorporating luminescent CdTe nanowires into these fibres imparts the new property of mechanically tunable circularly polarized luminescence. The nacre-like fibres open a novel technological space for optomechanics of biomimetic composites, while their continuous spinning methodology makes scalable production realistic.
authors.affiliation: Key Laboratory of Micro-systems and Micro-structures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136, USA.
authors.forename: Wenchun
authors.initials: W
authors.lastname: Feng
authors.affiliation: Key Laboratory of Micro-systems and Micro-structures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Huangxi
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Micro-systems and Micro-structures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Zhenlong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136, USA.
authors.forename: Heather A
authors.initials: HA
authors.lastname: Calcaterra
authors.affiliation: Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136, USA.
authors.forename: Bongjun
authors.initials: B
authors.lastname: Yeom
authors.affiliation: Key Laboratory of Micro-systems and Micro-structures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Ping An
authors.initials: PA
authors.lastname: Hu
authors.affiliation: Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136, USA.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Kotov