Eggplant-derived porous carbon encapsulating polyethylene glycol as phase change materials
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摘要: 以茄子為原材料,通過水熱處理–后續熱解法及直接熱解法分別制備出兩種不同的茄子衍生多孔碳材料(HBPC和BPC)。以茄子衍生多孔碳材料為載體,采用真空浸漬法負載相變芯材聚乙二醇(PEG2000),制備出聚乙二醇/茄子衍生多孔碳材料復合相變材料。通過掃描電鏡、拉曼光譜、壓汞法、傅里葉變換紅外光譜分析、X射線衍射儀、熱重分析儀和差示掃描量熱儀對其進行結構表征及性能測試。結果表明,通過直接熱解法制得的茄子衍生多孔碳材料為載體的聚乙二醇/茄子衍生多孔碳材料復合相變材料具有更好的相變儲熱效果,負載聚乙二醇的質量分數高達90.60%,熔融潛熱為133.98 J·g?1,達到了較好的定形相變效果及良好的循環穩定性。Abstract: Energy as a symbol of human civilization has a profound impact on human life. Fossil fuels, including coal, oil, and natural gas are still the most demanded and consumed energy sources in the world due to the worldwide economic expansion and population explosion. Thermal energy storage can not only alleviate the mismatch between energy supply and demand, but also improve the reliability of energy systems and the efficiency of thermal energy utilization. The thermal energy storage methods mainly include sensible heat storage and latent heat storage. Compared with sensible heat storage, latent heat storage has a much higher energy storage density. At present, phase change materials (PCMs) are widely used in solar heating systems, energy-saving buildings, air conditioning systems, and other fields. However, the practical application of PCMs has been limited by several persistent problems in various fields, such as the unstable shape of molten state, low thermal conductivity, and weak interface bonding of supporting materials. Therefore, to effectively solve the leakage problem and increase the thermal conductivity of composite PCMs, we seek porous materials with a high thermal conductivity as supports. In recent years, carbon-based materials derived from biomass have attracted extensive attention due to their excellent properties such as large specific surface area and adjustable porous structure. In this study, an eggplant-derived porous carbon material (HBPC) was prepared by hydrothermal synthesis, and another porous carbon material (biomass-derived porous carbon, BPC) was prepared by direct pyrolysis of eggplant. After that, PEG/HBPC and PEG/BPC composite PCMs were prepared by a vacuum-impregnated method using HBPC and BPC as supporting materials and polyethylene glycol (PEG2000) as PCMs. Their structure and performance were characterized by SEM, Raman spectroscopy, Mercury intrusion method, Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric (TG) analysis, and differential scanning calorimetry (DSC). The results show that PEG/BPC PCMs composite obtained by direct pyrolysis have a better energy storage effect, the mass fraction of PEG load is up to 90.60%, and the latent heat of melting is 133.98 J·g?1. At the same time, PEG/BPC composite is proved to be a shape-stable PCM with long-term stability.
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表 1 聚乙二醇、聚乙二醇/水熱處理的生物多孔碳和聚乙二醇/生物多孔碳復合相變材料的熱性能
Table 1. Thermal properties of PEG, PEG/HBPC, and PEG/BPC composite phase change materials
相變材料 負載量(質量分數)/% TM/℃ HM/(J·g?1) TS/℃ HS/(J·g?1) 聚乙二醇 100 55.87 164.92 17.65 149.34 PEG/HBPC 84.60 54.71 121.73 22.76 114.00 PEG/BPC 90.60 57.90 133.98 26.32 128.32 www.77susu.com -
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