Oriented Three-Dimensional Skeletons Assembled by Si3N4 Nanowires/AlN Particles as Fillers for Improving Thermal Conductivity of Epoxy Composites

Abstract

With the miniaturization of current electronic products, ceramic/polymer composites with excellent thermal conductivity have become of increasing interest. Traditionally, higher filler fractions are required to obtain a high thermal conductivity, but this leads to a decrease in the mechanical properties of the composites and increases the cost. In this study, silicon nitride nanowires (Si3N4NWs) with high aspect ratios were successfully prepared by a modified carbothermal reduction method, which was further combined with AlN particles to prepare the epoxy-based composites. The results showed that the Si3N4NWs were beneficial for constructing a continuous thermal conductive pathway as a connecting bridge. On this basis, an aligned three-dimensional skeleton was constructed by the ice template method, which further favored improving the thermal conductivity of the composites. When the mass fraction of Si3N4NWs added was 1.5 wt% and the mass fraction of AlN was 65 wt%, the composites prepared by ice templates reached a thermal conductivity of 1.64 W·m−1·K−1, which was ~ 720% of the thermal conductivity of the pure EP (0.2 W·m−1·K−1). The enhancement effect of Si3N4NWs and directional filler skeletons on the composite thermal conductivity were further demonstrated through the actual heat transfer process and finite element simulations. Furthermore, the thermal stability and mechanical properties of the composites were also improved by the introduction of Si3N4NWs, suggesting that prepared composites exhibit broad prospects in the field of thermal management.

Enhanced thermal management in electronic devices through control-oriented structures

“…Crystallization-induced orientation is an ingenious method for achieving material alignment. During the crystallization process of water or other liquid materials, 35,38,91–93 thermal conductive fillers are squeezed out towards the grain boundaries, resulting in the natural orientation behavior of the fillers. Directional crystallization naturally induces the orientation of thermal conductive fillers.…”

Unraveling the Impact of Boron Nitride and Silicon Nitride Nanoparticles on Thermoplastic Polyurethane Fibers and Mats for Advanced Heat Management

“…Boron nitride (BN) and silicon nitride (SiN) nanoparticles, possessing high thermal conductivity and mechanical strength, are widely utilized for manufacturing thermally conductive yet electrically insulating composites. − According to the literature, BN exhibits a thermal conductivity of up to 200 W m –1 K –1 , generally higher than SiN (up to 180 W m –1 K –1 ), and has garnered greater attention for enhancing the thermal conductivity of polymer composites. ,, However, there remains a gap in research regarding comparative studies on the role of BN and SiN in the thermal performance of polymer composites. Besides, SiN nanoparticles are commercially accessible in smaller sizes <50 nm in comparison to BN nanoparticles (approximately 150 nm) and, more importantly, with lower prices, highlighting the need for further exploration into the potential of SiN nanoparticles as a competitive alternative.…”