Although graphene-related nanocomposites have great potential for dissipating excess heat to ensure that electronic devices have high efficiencies and long service lives, their practical applications are restricted by the ultra-low through-plane thermal conductivity of these composites, which is due to interfacial thermal resistance between the graphene layers. Herein, exfoliated graphene (E-G)-boron nitride nanotube (E-G–BNNT) hierarchical structures are developed via the in situ growth of BNNTs on E-G. The BNNTs play an essential role in the construction of vertically aligned “bridges” for connecting E-G nanosheets during the hot-pressing process, while covalent C–N bonding at the E-G and BNNT interface creates a heat transfer pathway between graphene layers to reduce interfacial thermal resistance. The resultant E-G–BNNT composite has an architecture that is close to an ideal thermal conductive filler, and it is highly efficient at improving the through-plane thermal conductivity of PDVF-based nanocomposites, reaching 3.12 W m⁻¹ K⁻¹ at a loading of 15 wt%. Non-equilibrium molecular dynamics (NEMD) simulations further show that the development of covalent C–N bonding between E-G and BNNTs can effectively boost the interfacial thermal conductivity. Such excellent heat conduction performance allows the nanocomposite to show great potential for thermal management.

It remains a challenge to develop highly polymer-based nanocomposite thermal interface materials, which can effectively remove heat developed during the miniaturization of electronic instruments. It has been reported that a large number of graphene-based nanocomposites exhibit excellent performance. However, it is still an issue to construct thermal conductive pathways by orientation arrangements with a low filler volume fraction. Herein, a high-thermal conductivity filler of magnetic carbon nanotube-grafted graphene polyhedra (Co@Co₃O₄-G) was exploited via the annealing of metal–organic frameworks (ZIF-67). Co@Co₃O₄-G can improve the thermal conductivity of nanocomposites obviously by forming oriented pathways for phonon transport in an external magnetic field. Therefore, the resulting nanocomposite displayed a high thermal conductivity of 2.11 W m⁻¹ K⁻¹ for only 8.7 vol%, which is 10 times higher than that of the pure epoxy resin. Core-shell magnetic cobalt oxide (Co@Co₃O₄) was encapsulated in situ in the nanoarchitecture to avoid falling off. Moreover, the equilibrium molecular dynamics (EMD) simulation verifies that Co@Co₃O₄-G had high thermal conductivity to effectively improve the heat dissipation of nanocomposites. This strategy provides an approach for developing high-performance thermal management materials and opens up the possibility for the pioneering applications of encapsulated magnetic-oriented thermal conductive fillers.

PI-based graphene heat conductive composite with low interfacial thermal resistance was prepared via in situ polymerization involving modified graphene. Thermal conductivity of an integrated composite with multi-aspect covalent bonding was enhanced.

The high-performance electronic equipment appearing in the information age puts forward more comprehensive requirements for polymer-based composites with high heat dissipation capability, good mechanical properties, and substantial fire safety performance. However, the low interfacial interaction caused by the phase structural difference between the fillers greatly reduced the improvement of performance of the composites. It is feasible to overcome this issue by forming chemical interaction to regulate the interface structure. Herein, an anisotropic oriented composite is obtained by layer-by-layer self-assembly stacking of one-dimensional aramid nanofibers (ANFs) and ionic liquid (IL) functionalized two-dimensional boron nitride nanosheets (BNNSs). Considering the influence of the interface structure on the performance, the IL containing imidazolium ring and hexadecyl selected by density functional theory (DFT) form effective interface interactions with BNNSs. Owing to the establishment of multiple non-covalent bonding (cation–π, and CH–π) interactions, the composite exhibits not only high thermal conductivity (15.2 W m⁻¹ K⁻¹) and tensile strength (63.2 MPa) but also has excellent flame-retardant properties (limited oxygen index ≈ 45). Such an outstanding performance results in effectively cool light-emitting diode modules and desktop computers, outperforming a commercial thermal gasket. Significantly, molecular dynamics (MD) and DFT simulations further elucidate the role of IL in promoting heat transfer and the thermal conductivity mechanism between BNNS interfaces, respectively. This study offers a feasible strategy for constructing an interfacial structure by screening the modifier molecular configuration to perfect the excellent versatility of thermal management composites.