月桂酸/硬脂酸/纳米复合相变材料制备及性能研究

PREPARATION AND PROPERTIES OF LAURIC ACID/STEARIC ACID/NANOCOMPOSITE PHASE CHANGE MATERIALS

取月桂酸(LA)和硬脂酸(SA)作为相变材料(PCM),绘制LA/SA的二元平衡相图。研究发现,当LA与SA质量比为7∶3时,复合PCM达到最低共熔温度31.2℃,适用于建筑围护结构。并将纳米氧化铜(nano-CuO)、纳米二氧化硅(nano-SiO_(2))作为导热增强材料加入到复合PCM中,通过实验对比不同分散剂种类、不同纳米颗粒与分散剂比例、不同纳米颗粒浓度对实验材料稳定性和均匀性的影响,并基于傅里叶变换红外光谱(FT-IR)、差示扫描热量(DSC)测试、导热系数测试以及吸放热过程分析对其热物性进行表征和研究。实验结果表明:0.2%nano-CuO/PCM具有较好的稳定性,熔化潜热和凝固潜热相较于复合PCM分别降低了5.91%、5.44%;导热系数提高了30.0%。

In this paper,lauric acid(LA)and stearic acid(SA)were selected as phase change materials(PCMs),and the binary equilibrium phase diagram of LA/SA was drawn.It is found that when the ratio of LA/SA is 7∶3,the composite PCM reaches the lowest eutectic temperature of 31.2℃,which is suitable for building envelope.Nano-copper oxide(nano-CuO)and nano-silicon dioxide(nano-SiO_(2))were added into the composite PCM as thermal conductivity enhancing materials.The effects of different dispersants,different proportions of nanoparticles and dispersants,and different concentrations of nanoparticles on the stability and uniformity of experimental materials were compared.Based on Fourier transform infrared spectroscopy test(FT-IR),differential scanning calorimetry(DSC),thermal conductivity measurement,and thermal absorption and release process analysis,the thermal properties were characterized and studied.The experimental results show that 0.2%nano-CuO/PCM has good stability,and the latent heat of melting and solidification decreases by 5.91%and 5.44%,respectively,and the thermal conductivity increases by 30.0%compares with that of composite PCM.