Large-Area, Lightweight and Thick Biomimetic Composites with Superior Material Properties via Fast, Economic, and Green Pathways

TLDR

Nacre’s mechanically superior structure has been replicated in laboratory models, yet mainstream application remains hindered by time‑consuming, energy‑intensive deposition processes. This work introduces a simple, rapid technique to produce large‑area, lightweight, thick nacre‑mimetic films and laminates with superior material properties. The method employs nanoclay sheets coated with soft polymer as hard/soft building blocks that self‑assemble into aligned films via paper‑making, doctor‑blading, or painting, and is environmentally friendly, energy‑efficient, and scalable through continuous roll‑to‑roll processing. The films achieve a tensile modulus of 45 GPa and strength of 250 MPa—partly surpassing natural nacre—while offering excellent gas barrier, optical translucency, and fire‑resistance, suggesting applicability to lightweight sustainable construction and energy‑efficient transportation.

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.