纳米Fe_(2)O_(3)/硬脂酸/十八醇纳米复合相变蓄热材料的性能研究

STUDY ON PROPERTIES OF FERUMOXYTOL/STEARIC ACID/STEARYL ALCOHOL COMPOSITE PHASE CHANGE HEAT STORAGE MATERIAL

针对有机相变材料热导率低的问题,将高热导率的纳米Fe_(2)O_(3)添加到硬脂酸/十八醇二元有机复合蓄热相变材料中,制备纳米复合蓄热相变材料。从分散剂的种类、分散剂与纳米材料的添加量以及超声时间4个方面研究其对纳米复合相变蓄热材料的稳定性及热物性的影响。结果表明,阴离子表面活性剂的分散效果优于阳离子和非离子表面活性剂。复合相变材料中添加质量分数为0.8%,十二烷基苯磺酸钠(SDBS)和质量分数为0.4%Fe_(2)O_(3)的体系,超声时间为80 min时,纳米Fe_(2)O_(3)在相变材料中的分散效果最好。添加纳米Fe_(2)O_(3)后复合蓄热相变材料的相变潜热及相变温度有所下降,热导率提高34.9%。300次热循环复合相变材料的相变温度波动区间不超过0.41℃,相变潜热波动区间不超过4.0%,热稳定性良好。

Composite phase change materials are prepared using ferumoxytol,stearic acid and stearyl alcohol. The composite materials effectively improve the thermal conductivity of organic phase change material. The dispersants,the concentrations of ferumoxytol and dispersants are the key influencing factors,as well as ultrasound dispersing time. The experimental results show that the effect of anionic surfactant on Fe_(2)O_(3) dispersing is better that the effect of cationic surfactant or nonionic surfactant. The dispersing stability of Fe_(2)O_(3) in the composite PCMs reached the best effect when 0.8%,(wt)dispersant SDBS and 0.4%,(wt)Fe_(2)O_(3) are added into phase change material and the ultrasound dispersing time is 80 min. The latent heat of phase change and the phase transition temperature of the composite phase change material decreased a little with the addition of Fe_(2)O_(3). The thermal conductivity of the composite phase change material increased by 34.9%,compared to that of pure phase change material. The phase transition temperature changes no more than 0.41 ℃after 300 times melting/solidifying cycling tests,as well as the phase change latent heat fluctuation range doesn’t exceed 4.0% when Fe_(2)O_(3) is added into phase change material. The thermal stability of the composite phase change material is good.