纳米蒙脱土/混盐复合相变储能材料结构及性能研究  

Structure and Properties of Nano-montmorillonite/Mixed Salt Composites for Heat Storage

作　　者：高安旗 李玲[1] 董颖慧[1] 

机构地区：[1]暨南大学理工学院,广州510632

出　　处：《材料导报》2015年第8期52-56,共5页Materials Reports

基　　金：科技广东省公关项目(3241003);科技横向项目(40107032)

摘　　要：以三水乙酸钠-尿素共熔物、纳米蒙脱土为原料,采用熔融插层法制备低温水合盐复合相变储能材料,用XRD、SEM、FTIR和DSC测试了材料结构、结晶机理、成核性、过冷度、热性能及稳定性。研究结果表明,三水乙酸钠-尿素复合盐使纳米蒙脱土片层呈剥离形态,其片层相互搭建构成腔体包容复合盐;纳米蒙脱土作为成核剂使复合盐结晶温度提高18℃,晶粒尺寸减小;当纳米蒙脱土质量分数为33.3%时,所制备材料的过冷度比未加纳米蒙脱土时降低19℃,相变温度为32℃,熔融焓为132.0kJ/kg,纳米蒙脱土降低了复合盐的过冷度,避免了相变分层,赋予了复合盐成型性。Nanocomposite phase change materials （PCM） at low temperature were prepared from sodium ace- tate trihydrate （SAT）, urea and nano-montmorillonite （nano-MMT） by melt intercalation in a mixer. X-ray diffrac- tion （XRD）, scanning electron microscope （SEM）, Fourier transform infrared spectrometer （FTIR） and differential scanning calorimetry （DSC） were employed to study the composite constructure, crystal principle, nucleation mecha- nism, degree of undercooling, thermal property and stability of the mixed systems. The result indicated that nano- MMT formed exfoliated lamellas which could connect to each other in order to cover PCNL Nano-MMT, acting as an effective nucleating agent, increased the crystallization temperature by 18 ℃ and decreased the crystallite dimension. The novel composite material with 33. 3 wt% nano-MMT kept excellent thermal energy storage performances as the latent was 132 kJ/kg and the melting point was 32 ℃. The composites; degree of undercooling reduced by 19 ℃ compared to PCM without nano-MMT. The exfoliated nano-MMT lamellars could reduce degree of undercooling, avoide phase separation and keep the composites shaped.

关 键 词：纳米蒙脱土 三水乙酸钠/尿素复合盐 熔融插层法 相变储能材料 

分 类 号：TK02[动力工程及工程热物理]