Jung, Haejong Yu, Seunggun Bae, Nam-Seok Cho, Suk Man Kim, Richard Hahnkee Cho, Sung Hwan Hwang, Ihn Jeong, Beomjin Ryu, Ji Su Hwang, Junyeon Hong, Soon Man Koo, Chong Min Park, Cheolmin 2024-01-20T06:33:11Z 2024-01-20T06:33:11Z 2021-09-04 2015-07-22 1944-8244 https://pubs.kist.re.kr/handle/201004/125222 Design of materials to be heat-conductive in a preferred direction is a crucial issue for efficient heat dissipation in systems using stacked devices. Here, we demonstrate a facile route to fabricate polymer composites with directional thermal conduction. Our method is based on control of the orientation of fillers with anisotropic heat conduction. Melt-compression of solution-cast poly(vinylidene fluoride) (PVDF) and graphene nanoflake (GNF) films in an L-shape kinked tube yielded a lightweight polymer composite with the surface normal of GNF preferentially aligned perpendicular to the melt-flow direction, giving rise to a directional thermal conductivity of approximately 10 W/mK at 25 vol % with an anisotropic thermal conduction ratio greater than six. The high directional thermal conduction was attributed to the two-dimensional planar shape of GNFs readily adaptable to the molten polymer flow, compared with highly entangled carbon nanotubes and three-dimensional graphite fillers. Furthermore, our composite with its density of approximately 1.5 g/cm(3) was mechanically stable, and its thermal performance was successfully preserved above 100 degrees C even after multiple heating and cooling cycles. The results indicate that the methodology using an L-shape kinked tube is a new way to achieve polymer composites with highly anisotropic thermal conduction. English American Chemical Society BORON-NITRIDE PLATELETS INTERFACE MATERIALS GRAPHITE NANOPLATELET HEAT DISSIPATION NANOCOMPOSITES ALIGNMENT BEHAVIOR FILMS ELECTRONICS MANAGEMENT High Through-Plane Thermal Conduction of Graphene Nanoflake Filled Polymer Composites Melt-Processed in an L-Shape Kinked Tube Article 10.1021/acsami.5b02681 1 ACS Applied Materials & Interfaces, v.7, no.28, pp.15256 - 15262 ACS Applied Materials & Interfaces 7 28 15256 15262 scie scopus 000358558300018 2-s2.0-84937686900 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Science & Technology - Other Topics Materials Science Article BORON-NITRIDE PLATELETS INTERFACE MATERIALS GRAPHITE NANOPLATELET HEAT DISSIPATION NANOCOMPOSITES ALIGNMENT BEHAVIOR FILMS ELECTRONICS MANAGEMENT thermal conductivity graphene nanoflake L-shape kinked tube orientation polymer composite poly(vinylidene fluoride)