Bi2Se3 nanosheets: Advanced nanofillers for reinforcing and flame retarding polyethylene nanocomposites

Bi2Se3 nanosheets with few layers have been successfully synthesized by a practical and mass-producible wet chemical method in this work. as-prepared nanosheets showed excellent compatibility with polyethylene (PE), which was attributed to the polyvinylpyrrolidone (PVP) encapsulated structure, generated during preparation process. The “interface”, composed by PVP and PE molecular chains, enhanced the surface interaction between Bi2Se3 nanosheets and PE matrix, and thus improved the mechanical properties. Yield modulus of PE increased remarkably even at low loadings of nanofillers. The thermal stability and flame retardancy of PE host were significantly enhanced, including at least 60 °C increase in Ti, 37.6% and 20% decrease in pHRR and THR respectively. Meanwhile, the release of smoke and CO for PE/Bi2Se3 nanocomposites was suppressed during combustion. These phenomena mainly caused by the barrier effect of Bi2Se3. Thus, Bi2Se3 nanosheets could be potentially used to prepare functional polymers for certain applications.