title: Large-area, lightweight and thick biomimetic composites with superior material properties via fast, economic, and green pathways.
abstract: Although remarkable success has been achieved to mimic the mechanically excellent structure of nacre in laboratory-scale models, it remains difficult to foresee mainstream applications due to time-consuming sequential depositions or energy-intensive processes. Here, we introduce a surprisingly simple and rapid methodology for large-area, lightweight, and thick nacre-mimetic films and laminates with superior material properties. Nanoclay sheets with soft polymer coatings are used as ideal building blocks with intrinsic hard/soft character. They are forced to rapidly self-assemble into aligned nacre-mimetic films via paper-making, doctor-blading or simple painting, giving rise to strong and thick films with tensile modulus of 45 GPa and strength of 250 MPa, that is, partly exceeding nacre. The concepts are environmentally friendly, energy-efficient, and economic and are ready for scale-up via continuous roll-to-roll processes. Excellent gas barrier properties, optical translucency, and extraordinary shape-persistent fire-resistance are demonstrated. We foresee advanced large-scale biomimetic materials, relevant for lightweight sustainable construction and energy-efficient transportation.
authors.affiliation: Molecular Materials, Department of Applied Physics, Helsinki University of Technology/Aalto University, FIN-00076 Finland. Andreas.Walther@hut.fi
authors.forename: Andreas
authors.initials: A
authors.lastname: Walther
authors.forename: Ingela
authors.initials: I
authors.lastname: Bjurhager
authors.forename: Jani-Markus
authors.initials: JM
authors.lastname: Malho
authors.forename: Jaakko
authors.initials: J
authors.lastname: Pere
authors.forename: Janne
authors.initials: J
authors.lastname: Ruokolainen
authors.forename: Lars A
authors.initials: LA
authors.lastname: Berglund
authors.forename: Olli
authors.initials: O
authors.lastname: Ikkala
mesh_terms: D003247:Conservation of Natural Resources; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D018716:Molecular Mimicry; D053761:Nanocomposites / Q000191:economics