Smart heat management flexible cellulose films with enhanced thermal conductivity via assembling graphene and boron nitride nanosheets

Smart materials with high thermal conductivity are expected to have greatly application potential in thermal management for future electronic equipment. However, actual applications often require multifunctional properties of materials, such as high thermal conductivity (TC), good mechanical properties, and suitable electrical insulation performance. It is still a challenge to obtain such polymer composites with good comprehensive properties. Herein, the rational assembly of two-dimensional (2D) nanofillers of boron nitride nanosheets (BNNS) and graphene nanosheets (GNs) in nanofibrillated cellulose matrix is reported. The film shows 53.76 W m⁻¹ K⁻¹ of TC and 87.88 MPa of tensile strength. Meanwhile, the flexible film has the ability of response deformation by sensing the environmental temperature, which is promising for soft materials with excellent heat dissipation.