Surface Modification of Expanded Graphite with Copper Nanoparticles by Supercritical Method and its Thermal Properties

IF 3.4 4区工程技术 Q2 CHEMISTRY, MULTIDISCIPLINARY

Korean Journal of Chemical Engineering Pub Date : 2026-07-21 DOI:10.1007/s11814-026-00780-6

Junseo Park, Hyeon Soo Kwon, Oh Ruem Lee, Won Gyu Lee

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Abstract

Copper nanoparticle–expanded graphite (CuNPs/EG) composites were developed to improve through-plane heat transport in graphite-based thermal interface materials (TIMs). Copper nanoparticles (CuNPs) were synthesized by chemical reduction using polyethylene glycol and ascorbic acid to suppress aggregation and oxidation, and were then incorporated into expanded graphite (EG) by a supercritical carbon dioxide (scCO₂)-assisted intercalation process. X-ray diffraction (XRD) confirmed the formation of metallic CuNPs, and dynamic light scattering (DLS) showed a particle size distribution of approximately 150–650 nm with a main peak near 350 nm. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) indicated that ethanol used as a co-solvent produced a more homogeneous distribution of Cu species within the expanded interlayer voids and porous regions of EG than isopropyl alcohol. Cross-sectional SEM/EDS analysis further showed Cu-containing particles distributed inside the composite film. After 14 days of air exposure at 25 °C and 40% relative humidity, only weak oxygen signals were detected from CuNPs embedded within EG, indicating improved oxidation stability. Laser flash analysis showed that the CuNPs/EG composite prepared using ethanol exhibited a through-plane thermal conductivity of 8.402 W/m·K, a 124.5% increase compared with pristine EG, while retaining an in-plane thermal conductivity of 90.854 W/m·K. These results demonstrate that ethanol-assisted scCO₂ intercalation is an effective strategy for developing oxidation-stable CuNPs/EG composites with enhanced through-plane thermal transport.

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纳米铜对膨胀石墨的超临界改性及其热性能研究

为了改善石墨基热界面材料（TIMs）的平面传热性能，研制了铜纳米颗粒-膨胀石墨（CuNPs/EG）复合材料。以聚乙二醇和抗坏血酸为抑制聚集和氧化的原料，通过化学还原法制备了铜纳米粒子（cups），并采用超临界二氧化碳（scCO₂）辅助插层工艺将其掺入膨胀石墨（EG）中。x射线衍射（XRD）和动态光散射（DLS）结果表明，纳米粒子的粒径分布在150 ~ 650 nm之间，主峰位于350 nm附近。扫描电镜（SEM）和x射线能谱分析（EDS）结果表明，乙醇作为助溶剂比异丙醇更能使Cu在EG膨胀的层间空隙和多孔区域内分布均匀。截面SEM/EDS分析进一步表明，复合膜内部分布有含cu颗粒。在25°C和40%相对湿度的空气中暴露14天后，仅从嵌入在EG中的cunp中检测到微弱的氧气信号，表明氧化稳定性得到改善。激光闪蒸分析表明，乙醇制备的CuNPs/EG复合材料的平面导热系数为8.402 W/m·K，比原始EG提高了124.5%，而平面内导热系数为90.854 W/m·K。这些结果表明，乙醇辅助的scCO 2插层是制备氧化稳定的CuNPs/EG复合材料的有效策略。

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来源期刊

Korean Journal of Chemical Engineering 工程技术-工程：化工

CiteScore

4.60

自引率

11.10%

发文量

310

审稿时长

4.7 months

期刊介绍： The Korean Journal of Chemical Engineering provides a global forum for the dissemination of research in chemical engineering. The Journal publishes significant research results obtained in the Asia-Pacific region, and simultaneously introduces recent technical progress made in other areas of the world to this region. Submitted research papers must be of potential industrial significance and specifically concerned with chemical engineering. The editors will give preference to papers having a clearly stated practical scope and applicability in the areas of chemical engineering, and to those where new theoretical concepts are supported by new experimental details. The Journal also regularly publishes featured reviews on emerging and industrially important subjects of chemical engineering as well as selected papers presented at international conferences on the subjects.