Facile Strategy for Constructing Highly Thermally Conductive Epoxy Composites Based on a Salt Template-Assisted 3D Carbonization Nanohybrid Network

The construction of an interconnected nanofiller network is critical for the preparation of highly effective thermal management composites, though it remains a challenge to eliminate the anisotropic thermal conductivity of the nanofiller-induced defective interfacial heat-flow efficiency. In this work, a facile and novel approach is proposed to optimize phonon transport by building a salt template-assisted three-dimensional (3D) carbonization nanohybrid network in an epoxy system. The advantage of the salt template relied on green and scalable merits to construct a 3D nanofiller network and supporting abundant holes for the introduction of a polymer matrix after washing. Meanwhile, the contained carbonization materials contributed to reducing the interfacial phonon scattering issues of the filler/filler and filler/polymer for an efficient heat-flow pathway. As a result of this effect, the prepared epoxy nano-composites presented a high thermal conductivity of 4.27 W/m K, resulting in a 1841% increase compared to the thermal conductivity of the pure epoxy resin. In addition, the epoxy composites exhibited good mechanical properties and thermal conductive performance during heating and cooling. Therefore, this study may provide new insights into the design and preparation of thermal management polymers to meet the applicational requirements of electronics.

Multifunctional Thermal Management Materials with Excellent Heat Dissipation and Generation Capability for Future Electronics

Thermal management materials (TMMs) used in electronic devices are crucial for future electronics and technologies such as flexible electronics and artificial intelligence (AI) technologies. As future electronics will work in a more complicated circumstance, the overheating and overcooling problems can exist in the same electronics while the common TMMs cannot meet the demand of thermal management for future electronics. In this work, nacre-mimetic graphene-based films with super flexibility and durability (in over 10,000 tensile cycles), excellent capability to dissipate excess heat (20.84 W/(m·K) at only 16-22 μm thickness), and outstanding heating performance to generate urgent heat for electronics under extremely cold conditions are fabricated by a facile solution casting method, and the fabricated composites are proved to be superior multifunctional TMMs for the thermal management in electronic chips. In addition, the application of the paper-like films with high in-plane thermal conductivity to a flexible heat spreader and film heater is demonstrated by simulation using a finite volume method, which shows the high importance of the in-plane thermal conductivity in thermal management of electronics.

Scalable Approach to Construct Self-Assembled Graphene-Based Films with An Ordered Structure for Thermal Management

Large-area bulk oxidized cellulose nanocrystal (OCNC)/graphene nanocomposites with highly oriented structures were produced through a straightforward, cost-effective large-scale evaporation-induced self-assembly process followed by thermal curing. Well-aligned nano-sized graphene layers were evident and separated by the OCNC planar layers, which facilitate highly interconnected and continuous thermal transport parallel to the alignment. Hence, the laminated graphene-based nanocomposites possess an excellent in-plane thermal conductivity of 25.66 W/m K and a thermal conductivity enhancement (η) of 7235% with only a 4.1 vol % graphene loading. This value is the highest recorded among all laminated composite films with <70 wt % filler content reported to date. Using this design strategy, other large-area aligned composites with other functional nanomaterials, already in large-scale production, can be made for use in a wide range of applications.