Artificial nacre-like papers based on noncovalent functionalized boron nitride nanosheets with excellent mechanical and thermally conductive properties

Abstract

Inspired by the nano/microscale hierarchical structure and the precise inorganic/organic interface of natural nacre, we fabricated artificial nacre-like papers based on noncovalent functionalized boron nitride nanosheets (NF-BNNSs) and poly(vinyl alcohol) (PVA) via a vacuum-assisted self-assembly technique. The artificial nacre-like papers exhibit excellent tensile strength (125.2 MPa), on a par with that of the natural nacre, and moreover display a 30% higher toughness (2.37 MJ m⁻³) than that of the natural nacre. These excellent mechanical properties result from an ordered ‘brick-and-mortar’ arrangement of NF-BNNSs and PVA, in which the long-chain PVA molecules act as the bridge to link NF-BNNSs via hydrogen bonds. The resulting papers also render high thermal conductivity (6.9 W m⁻¹ K⁻¹), and reveal their superiority as flexible substrates to support light-emitting-diode chips. The combined mechanical and thermal properties make the materials highly desirable as flexible substrates for next-generation commercial portable electronics.