Biocompatible nacre-like boron nitride/biopolymer nanocomposites for thermal management

Thermally conductive materials (TCMs), especially electrically insulating polymer nanocomposites, have attracted considerable attention for thermal management applications, driven by the increasing heat generation in advanced processors and integrated circuits. While conventional polymer nanocomposites offer excellent thermal conductivity and mechanical performance, their dependence on non-biodegradable plastics or resins poses significant environmental concerns. In contrast, chitosan and gelatin are biodegradable, cost-effective and represent promising sustainable alternatives. In this study, thermally conductive nanocomposite films were fabricated by vacuum-assisted filtration (VAF) of functionalized boron nitride nanosheets (FBN) combined with gelatin or chitosan. The strong interaction between the amino groups on the boron nitride surface and the biopolymer chains facilitated the formation of a robust network, resulting in outstanding thermal conductivity. Notably, the composite film containing 30 wt% FBN with chitosan exhibited an impressive in-plane thermal conductivity (κ) of 52.52 W·m⁻¹ ·K⁻¹ . Additionally, the self-assembled nacre-like structure enables the nanocomposite films to achieve an impressive tensile strength of 129.3 ± 0.4 MPa. Importantly, in vitro cell viability assays showed over 80 % cell survival, confirming the excellent biocompatibility of these films. The newly developed nanocomposite films demonstrate non-cytotoxicity, biocompatibility and outstanding thermal conductivity, positioning them as a promising nanocomposite heat sink for future green and sustainable thermal management applications.