空调用纳米有机复合相变蓄冷材料分散稳定性

纳米材料在有机相变蓄能材料中的分散稳定性对其整体性能的保持具有决定性作用.本文将具有高导热性的纳米材料(MWNTs、Al₂O₃、Fe₂O₃)添加到热导率较低的空调用有机相变材料(质量比为73.7:26.3的辛酸/肉豆蔻醇)中,制备了纳米复合蓄冷材料;利用测量热导率的高低来间接反映分散稳定性的好坏,研究了分散剂种类、分散剂浓度和超声分散时间对纳米复合有机相变材料分散稳定性的影响.实验证明:分散剂十二烷基苯磺酸钠(SDBS)对纳米复合材料的分散稳定效果最好;当添加的分散剂SDBS与不同纳米材料MWNTs、Al₂O₃和Fe₂O₃质量比分别为2:1、3:1和3:1时,所对应的分散稳定性能最好;超声分散时间为90min时纳米复合材料的分散稳定性能最优.为获得性能良好、稳定的纳米有机复合材料提供了新的评价方法和指导.

Dispersion stability of nano-organic composite phase change materials for cool storage in air-conditioning

The dispersion stability of nanomaterials plays a decisive role on retaining the good performance of nano-organic composite phase change materials (PCMs),when nanomaterials are used as heat transfer enhancement additive of PCMs. To prepare nano-organic composite PCMs for air-conditioning cool storage,nanomaterials with high thermal conductivity,including MWNTs,Al₂O₃ and Fe₂O₃,were respectively added into the organic composite PCMs of caprylic acid/myristyl alcohol (with a mass ratio of 73.7 to 26.3),developed previously in our study. The dispersing stability of nano-organic composite PCMs was analyzed indirectly by measuring their thermal conductivity coefficients. The kinds and concentrations of nano-material and dispersant are key influencing factors,as well as ultrasound dispersing time. The experimental results showed that the SDBS had the best dispersing effect on the composite PCMs,and the dispersing stability of the composite PCMs reached optimum,when the ultrasound dispersing time was 90 min,and mass ratios between the dispersant SDBS and MWNTs,Al₂O₃,Fe₂O₃ were 2:1,3:1,3:1,respectively. The new evaluation method and guide to obtain the nano-organic composite PCMs with good and stable performance were proposed in this paper.