Abstract Graphene oxide (GO) nanosheets were employed as the additive to make composites of erythritol, a promising medium-temperature PCM candidate. GO nanosheets modified with hydroxyl groups were applied to improve the dispersion stability of the composites. A systematic characterization on the latent heat storage performance was performed for both pure and composite erythritol, in order to identify the benefits and challenges of the composites. It was found that the thermal conductivity is increased by nearly twice and the degree of supercooling was lowered from ~64 °C to ~48 °C at the loading of 1.0 wt% GO nanosheets (the maximum loading tested). The addition of GO nanosheets also leads to an increase of the retrievable latent heat during crystallization, from ~187 kJ/kg to ~225 kJ/kg at the same loading, by increasing the crystallinity. However, the introduction of GO nanosheets can also lead to a rise in the dynamic viscosity of erythritol. As a result, the crystallization rate is slowed down and accordingly, the duration of crystallization becomes 62% longer when the loading reaches 1.0 wt%. In addition, favorable dispersion stability of the erythritol composites is observed, and their melting point (~117 °C) remains almost unchanged during 50 melting-crystallization cycles. Functionalized GO nanosheets have been shown to be an efficient additive for improving the performance of erythritol, but a trade-off analysis on the loading would be required to achieve the best overall performance.

中文翻译：

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羟基官能化氧化石墨烯纳米片作为添加剂改善赤藓糖醇潜热储存性能：对益处和挑战的综合评估

摘要 采用氧化石墨烯 (GO) 纳米片作为添加剂制备赤藓糖醇复合材料，赤藓糖醇是一种有前途的中温 PCM 候选材料。应用羟基改性的GO纳米片来提高复合材料的分散稳定性。对纯赤藓糖醇和复合赤藓糖醇的潜热存储性能进行了系统表征，以确定复合材料的优点和挑战。发现在负载 1.0 wt% GO 纳米片（测试的最大负载）时，热导率增加了近两倍，过冷度从~64°C 降低到~48°C。通过增加结晶度，GO纳米片的添加还导致结晶过程中可回收的潜热增加，在相同负载下从~187 kJ/kg增加到~225 kJ/kg。然而，GO纳米片的引入也会导致赤藓糖醇的动态粘度升高。结果，结晶速度减慢，相应地，当负载量达到 1.0 wt% 时，结晶持续时间延长 62%。此外，观察到赤藓糖醇复合材料具有良好的分散稳定性，它们的熔点（~117°C）在 50 次熔融-结晶循环中几乎保持不变。功能化的 GO 纳米片已被证明是提高赤藓糖醇性能的有效添加剂，但需要对负载进行权衡分析才能实现最佳整体性能。当负载量达到 1.0 wt% 时，结晶持续时间延长 62%。此外，观察到赤藓糖醇复合材料具有良好的分散稳定性，它们的熔点（~117°C）在 50 次熔融-结晶循环中几乎保持不变。功能化的 GO 纳米片已被证明是提高赤藓糖醇性能的有效添加剂，但需要对负载进行权衡分析才能实现最佳整体性能。当负载量达到 1.0 wt% 时，结晶持续时间延长 62%。此外，观察到赤藓糖醇复合材料具有良好的分散稳定性，它们的熔点（~117°C）在 50 次熔融-结晶循环中几乎保持不变。功能化的 GO 纳米片已被证明是提高赤藓糖醇性能的有效添加剂，但需要对负载进行权衡分析才能实现最佳整体性能。