Abstract In this study, stability, density, rheology, and thermal conductivity of the Multi-wall carbon nanotubes (MWCNTs) based PCM nanocomposites were experimentally investigated. The PCM OM08 has been selected for the air-conditioning application with a phase change temperature of 8–10 °C. PCM nanocomposites (without surfactant) in various concentrations namely 0.05, 0.1, 0.3 and 0.5 vol. % were prepared using a typical two-step method and high homogenous stability is achieved using a mechanical mixing technique (ultra-sonication). The density of PCM nanocomposites was measured using two different types of standard volumetric flask approach and the experimental values confirmed good conformity with the Pak and Cho mixing theory. The highest thermal conductivity augmentation of 24.03%and 64.04% were achieved in liquid and solid states, respectively, with 0.5 vol. % of MWCNT. While, the addition of MWCNT resulted in a changeover of Newtonian to Non-Newtonian behaviors at a low shear rate, and the dynamic viscosity enhancement was increased by 130% with 0.5 vol. % of MWCNT. Further, the results were compared with existing correlations and it was found that the experimental values were in line with existing correlations.

中文翻译：

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碳辅助相变纳米复合材料的热传输特性

摘要 本研究对基于多壁碳纳米管 (MWCNT) 的 PCM 纳米复合材料的稳定性、密度、流变学和热导率进行了实验研究。PCM OM08 已被选择用于相变温度为 8–10 °C 的空调应用。不同浓度的 PCM 纳米复合材料（不含表面活性剂），即 0.05、0.1、0.3 和 0.5 体积。% 是使用典型的两步法制备的，并且使用机械混合技术（超声波）实现了高度的均匀稳定性。使用两种不同类型的标准容量瓶方法测量 PCM 纳米复合材料的密度，实验值证实了与 Pak 和 Cho 混合理论的良好一致性。在液态和固态下实现了最高的 24.03% 和 64.04% 的热导率增加，分别为 0.5 vol。MWCNT 的百分比。同时，MWCNT的加入导致在低剪切速率下牛顿行为向非牛顿行为的转变，并且动态粘度增强增加了130％，体积为0.5 vol。MWCNT 的百分比。此外，将结果与现有相关性进行比较，发现实验值与现有相关性一致。