Spinelli Giovanni, Guarini Rosella, Guadagno Liberata, Naddeo Carlo, Vertuccio Luigi, Romano Vittorio
Faculty of Transport Sciences and Technologies, University of Study "Giustino Fortunato", Via Raffaele Delcogliano 12, 82100 Benevento, Italy.
Open Laboratory on Experimental Micro and Nano Mechanics, Institute of Mechanics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Block 4, 1113 Sofia, Bulgaria.
Polymers (Basel). 2025 May 3;17(9):1248. doi: 10.3390/polym17091248.
Understanding and optimizing thermal conductivity in epoxy-based composites is crucial for efficient thermal management applications. This study investigates the anisotropic thermal conductivity of a tetra-functional epoxy resin filled with low concentrations (0.25-2.00 wt%) of carbonaceous nanofillers: 1D multiwall carbon nanotubes (MWCNTs) and 2D exfoliated graphite (EG) nanoparticles. Experimental measurements conducted using the Transient Plane Source (TPS) method reveal distinct behaviors depending on the nanofiller's geometry. Epoxy formulations incorporating MWCNTs exhibit a ~60% increase in in-plane thermal conductivity (λ) compared to the unfilled resin, with negligible changes in the through-plane direction (λ). Conversely, EG nanoparticles enhance thermal conductivity in both directions, with a preference for the in-plane direction, achieving a ~250% increase at 2 wt%. In light of this, graphene-based fillers establish a predominant thermal transport direction in the resulting nanocomposites due to their layered structure, whereas MWCNTs create unidirectional thermal pathways. The TPS results were complemented by multiphysics simulations in COMSOL and theoretical studies based on the theory of thermal circuits to explain the observed phenomena and justify the experimental findings. This integrated approach, combining experiments, theoretical analyses, and simulations, demonstrates the potential for tailoring the thermal properties of epoxy nanocomposites. These insights provide a foundation for developing advanced materials optimized for efficient thermal management in high-performance systems.
了解并优化环氧基复合材料的热导率对于高效热管理应用至关重要。本研究调查了填充低浓度（0.25 - 2.00 wt%）碳质纳米填料的四官能环氧树脂的各向异性热导率，这些填料包括一维多壁碳纳米管（MWCNT）和二维片状石墨（EG）纳米颗粒。使用瞬态平面热源（TPS）方法进行的实验测量揭示了取决于纳米填料几何形状的不同行为。与未填充的树脂相比，掺入MWCNT的环氧配方在面内热导率（λ）方面提高了约60%，而在厚度方向（λ）上变化可忽略不计。相反，EG纳米颗粒在两个方向上均提高了热导率，且更倾向于面内方向，在2 wt%时实现了约250%的增长。鉴于此，基于石墨烯的填料由于其层状结构在所得纳米复合材料中建立了主要的热传输方向，而MWCNT则形成了单向热通路。TPS结果通过COMSOL中的多物理场模拟以及基于热电路理论的理论研究得到补充，以解释观察到的现象并验证实验结果。这种结合实验、理论分析和模拟的综合方法展示了定制环氧纳米复合材料热性能的潜力。这些见解为开发针对高性能系统中高效热管理进行优化的先进材料奠定了基础。
