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With the development of miniaturized and highly integrated of microelectronic products, it has become particularly important to fabricate a thermally conductive, electrically insulating and environment-friendly composite as a thermal interface material (TIM) for heat dissipation. Here, we designed the structure of a multilayer thermally conductive hybrid film based on nanofibrillated cellulose and fillers (graphene and boron nitride) using the vacuum-assisted layer-by-layer (VA-LBL) self-assembly technique. Fully unifying the advantages of the thermally conductive three-layer electrically insulating film and an antistatic film, the ordered five-layer thermally conductive film (7.04 W m−1 K−1 with 8 wt% fillers) exhibits a comprehensive performance with electrically insulating and antistatic properties, which simultaneously has an excellent tensile strength (172 MPa). Therefore, it could be applied as a TIM for various thermal management applications with diverse requirements in a safe and environmentally friendly manner.

It is urgent to manufacture a polymer composite that has high thermal conductivity and mechanical properties simultaneously to meet the heat dissipation requirement of electronic devices. In this paper, we report a bridge effect of Silicon Carbide whiskers (SiCw) on the enhancement of thermal conductivity (TC) in polyamide-6/graphene (PG) composites. The composite was made by melting, stirring through an Internal mixer. Experimental results show that the TC of the PG composites increases with additional introduction of SiCw, particularly in the through-plane direction. For example, based on the PG-2 sample (2 wt% graphene in polyamide-6 (PA) matrix), the thermal conductivity enhancement (TCE) of PASC-24 (similar to 2 wt% graphene and 43.2 wt% SiCw in the PA matrix) in the through-plane direction is 199%, while in contrast, the TCE in the in-plane direction is just 5.4%. Meanwhile, the mechanical properties of the composites are synchronously enhanced, indicating that it is a convenient method and can be widely applied in various thermal interface materials (TIMs) and thermal management systems.

The miniaturization, integration, and lightweight of modern electronics have posed serious challenges to the development of high-performance and multifunctional thermal management materials. Here, we reported SiO2-coated nanofibrillated cellulose (NFC)/boron nitride nanosheets (BNNS) hybrid films with excellent thermal conductivity (TC) and hydrophobicity. These films were easily constructed via vacuum-assisted filtration and subsequent hydrophobic coating. The hybrid films exhibit a well-defined aligned structure with in-plane oriented BNNS. This finding was proven via wide-angle and small-angle X-ray scattering techniques, allowing for a high TC of up to 10.88 W m−1 K−1 at a low BNNS content of 7 wt%. Moreover, the hydrophobic hybrid films achieve high tensile strength (166.47 MPa) and electrical insulating property (volume resistivity = 1.2 × 1012 Ω cm). Inspired by the lotus effect, the water contact angle of such hydrophobic hybrid films reaches 143°, showing great potential in real applications for preventing the adverse effects of water and moisture.