表面活性剂协同超声分散制备还原氧化石墨烯＠月桂酸Ｇ棕榈酸复合相变材料及其表征

相变储能材料因能有效地解决能量供求中时间和空间不匹配的矛盾而备受关注。本实验首先采用熔融共混法制得月桂酸(LA)-棕榈酸(PA)低共熔混合物后,将其与还原氧化石墨烯(RGO)混合,通过超声分散制得还原氧化石墨烯@月桂酸-棕榈酸(RGO@LA-PA)复合相变材料。FT-IR、Raman、SEM、DSC和形貌稳定性的分析结果表明,RGO与LA-PA是以物理方式结合,所添加的RGO能对材料形成均匀包覆,仅1%(质量分数)的RGO就能使其导热系数提升20%为0.426 W·m-1·K-1,相变潜热为159.9 J·g-1,起始分解温度提高2 ℃；经100次热循环后,其相变潜热仅下降2%,说明RGO包覆相变材料后提高了其导热性能,改善了其渗漏现象,同时该复合相变材料还具有良好的热稳定性。

Preparation and Characterization of Reduced Graphene Oxide@LA-PA Composite Phase Change Material Prepared by Surfactant and Ultrasonic Dispersion

Phase change material for energy conversion can effectively solve the problem of mismatch between time and space in energy supply and demand, which is a matter of great concern. Firstly, lauric acid-palmitic acid (LA-PA) eutectic mixture was prepared by melt blending method. And then, reduced graphene oxide @lauric acid-palmitic acid (RGO@LA-PA) composite phase change material was prepared by ultrasonic dispersion method. The structure and thermal performance of prepared RGO@LA-PA composite phase change material were characterized by FT-IR, Raman, SEM, DSC, thermal cycling test and morphology stability test. The results showed that the RGO and LA-PA eutectic mixture were combined in a physical way. The thermal conductivity and latent heats of RGO@LA-PA composite phase change material were improved 20% to 0.426 W·m-1·K-1 and 159.9 J·g-1 by adding 1wt% RGO, respectively. In thermal cycling test, the latent heats of RGO@LA-PA reduced 2% after 100 times thermal cycle, which indicated that the RGO could improve the thermal conductivity of the phase change material and eliminate the leakage phenomenon and the RGO@LA-PA had a good thermal reliability.