title: Sustainable self-healing at ultra-low temperatures in structural composites incorporating hollow vessels and heating elements.
abstract: Self-healing composites are able to restore their properties automatically. Impressive healing efficiencies can be achieved when conditions are favourable. On the other hand, healing might not be possible under adverse circumstances such as very low ambient temperature. Here, we report a structural composite able to maintain its temperature to provide a sustainable self-healing capability-similar to that in the natural world where some animals keep a constant body temperature to allow enzymes to stay active. The composite embeds three-dimensional hollow vessels with the purpose of delivering and releasing healing agents, and a porous conductive element to provide heat internally to defrost and promote healing reactions. A healing efficiency over 100% at around -60°C was obtained. The effects of the sheets on the interlaminar and tensile properties have been investigated experimentally. The proposed technique can be implemented in a majority of extrinsic self-healing composites to enable automatic recovery at ultra-low temperatures.
authors.affiliation: Department of Mechanical Engineering, School of Engineering , University of Birmingham , Edgbaston, Birmingham , UK.
authors.forename: Yongjing
authors.identifier: 0000-0002-9640-0871
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Mechanical Engineering, School of Engineering , University of Birmingham , Edgbaston, Birmingham , UK.
authors.forename: Duc Truong
authors.initials: DT
authors.lastname: Pham
authors.affiliation: Center for Composite Materials and Structures , Harbin Institute of Technology , Science Park, Harbin , People's Republic of China.
authors.forename: Zhichun
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Applied Science Faculty , Delft University of Technology , Delft , The Netherlands.
authors.forename: Jinjun
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Mechanical Engineering, School of Engineering , University of Birmingham , Edgbaston, Birmingham , UK.
authors.forename: Chunqian
authors.initials: C
authors.lastname: Ji
authors.affiliation: Department of Aerospace Science and Mechanics , Harbin Institute of Technology , Science Park, Harbin , People's Republic of China.
authors.forename: Yanju
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Center for Composite Materials and Structures , Harbin Institute of Technology , Science Park, Harbin , People's Republic of China.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Leng
keywords: carbon nanotubes; delamination; fibre-reinforced composites; self-healing; self-repair; smart materials