Enhanced In-Plane Thermal Conductivity and Mechanical Strength of Flexible Films by Aligning and Interconnecting Si₃N₄ Nanowires

Abstract

As the rapid development of advanced foldable electronic devices, flexible and insulating composite films with ultra-high in-plane thermal conductivity have received increasing attention as thermal management materials. Silicon nitride nanowires (Si 3 N 4 NWs) have been considered as promising fillers for preparing anisotropic thermally conductive composite films due to their extremely high thermal conductivity, low dielectric properties, and excellent mechanical properties. However, an efficient approach to synthesize Si 3 N 4 NWs in a large scale still need to be explored. In this work, large quantities of Si 3 N 4 NWs were successfully prepared using a modified CRN method, presenting the advantages of high aspect ratio, high purity, and easy collection. On the basis, the super-flexible PVA/Si 3 N 4 NWs composite films were further prepared with the assistance of vacuum filtration method. Due to the highly oriented Si 3 N 4 NWs interconnected to form a complete phonon transport network in the horizontal direction, the composite films exhibited a high in-plane thermal conductivity of 15.4 W•m −1 •K −1 . The enhancement effect of Si 3 N 4 NWs on the composite thermal conductivity was further demonstrated by the actual heat transfer process and finite element simulations. More significantly, the Si 3 N 4 NWs enabled the composite film presenting good thermal stability, high electrical insulation, and excellent mechanical strength, which was beneficial for thermal management applications in modern electronic devices.

Enhanced thermal management in electronic devices through control-oriented structures

“…In addition to the orientation methods mentioned earlier, there are several other approaches available to create aligned structures for the development of materials with high thermal conductivity, such as self-assembly, [100][101][102][103] rolling and cutting, [104][105][106] and vacuum ltration. 60,[107][108][109] Thermally conductive functionalized multilayer graphene sheets (fMGs) are effectively aligned using a vacuum ltration method, and subsequently vertically assembled between silicon/silicon surfaces that are in contact with each other (Fig. 19a1).…”

Enhancing the Thermal Conductivity of Epoxy Composites via Constructing Oriented ZnO Nanowire-Decorated Carbon Fibers Networks

“…In the field of heat dispassion, thermal interface materials (TIMs) play an important role, generally used between chips and heat sinks to fill with the microscopic voids and holes, thus reducing the contact thermal resistance, establishing effective pathways for heat transfer, and improving the heat dissipation ability of electronic devices. Therefore, the development of high-performance TIMs is of great scientific significance and commercial value in response to the rapidly growing demand for heat dissipation [4][5][6][7].…”

In situ construction of vertically aligned AlN skeletons for enhancing the thermal conductivity of stearic acid-based phase-change composites

“…and ceramics ( e.g. AlN, 15–18 Al 2 O 3 , 19 Si 3 N 4 , 20,21 BN, 22,23 etc. ) are the most common thermally conductive fillers.…”