Graphene-decorated silica stabilized stearic acid as a thermal energy storage material
Graphene-decorated silica stabilized stearic acid as a thermal energy storage material
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石墨烯修饰二氧化硅稳定硬脂酸作为热能储存材料
DOI：
10.1039/c7ra05204a
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发表时间：
2017-01-01
期刊：
影响因子：
3.9
通讯作者：
Chen, Jian
中科院分区：
文献类型：
--
作者：
Li, Chuanchang;Xie, Baoshan;Chen, Jian
以石墨烯修饰二氧化硅(SG)和硬脂酸(SA)为原料，采用真空浸渍法制备了新型储能材料。通过对不同石墨烯含量的二氧化硅进行表面修饰，制备了3种SG(SG(1)、SG(5)和SG(10))，并用其稳定SA制备了SA/SG(1)、SA/SG(5)和SA/SG(10)复合材料。研究了SA/SG复合材料的结构和储能性能。值得注意的是，随着石墨烯含量的不同，SA/SG复合材料的储能行为发生了很大的变化，在DSC曲线上出现了多个吸热峰或放热峰，而纯SA只有一个吸热峰或放热峰。SA/SG(1)和SA/SG(5)中的SA比SA/SG(10)中的SA具有更高的结晶度(F-c，84.44%和84.39%)和更大的单位质量有效储能(E-ef，相当于150 J g(-1))。这些储能行为和性能与SG的孔结构有关。用热重分析仪(TGA)对SA/SG复合材料的热稳定性进行了分析，结果表明SA/SG复合材料具有良好的热稳定性。石墨烯的加入有利于提高SA/SG复合材料的导热系数，SA/SG(1)、SA/SG(5)和SA/SG(10)的导热系数分别达到0.90Wm(-1)K-1、1.05Wm(-1)K-1和1.12Wm(-1)K-1，分别比纯SA高出246%、304%和331%。由于SA/SG(5)同时具有较高的E-ef和导热系数，因此在热能存储方面具有潜在的应用前景，特别是在热梯度方面。
Novel thermal energy storage materials were synthesized from graphene-decorated silica (SG) and stearic acid (SA) by vacuum impregnation method. Three kinds of SG (SG(1), SG(5), and SG(10)) were prepared by decorating silica with different contents of graphene and were then used to stabilize SA to prepare SA/SG(1), SA/SG(5), and SA/SG(10) composites. The structures and thermal energy storage performances of the SA/SG composites were investigated. It is of interest that the thermal energy storage behaviors of the SA/SG composites were dramatically changed with different contents of graphene, presenting more than one endothermal or exothermal peak in the differential scanning calorimetry (DSC) curves while pure SA had only one. The SA in SA/SG(1) and SA/SG(5) showed higher crystallinity (F-c, 84.44% and 84.39%) and greater effective energy storage per unit mass (E-ef, similar to 150 J g(-1)) than that of SA in SA/SG(10). These thermal energy storage behaviors and properties were revealed to be related to the pore structures of the SG. The thermal stability of the SA/SG composites was analyzed by a thermogravimetric analyzer (TGA), and the SA/SG composites have good thermal stability. Addition of graphene was beneficial to the enhancement in thermal conductivity of the SA/SG composite, which could reach 0.90 W m(-1) K-1, 1.05 W m(-1) K-1, and 1.12 W m(-1) K-1 for SA/SG(1), SA/SG(5), and SA/SG(10), respectively; and were 246%, 304%, and 331% higher than pure SA, respectively. SA/SG(5) has potential for application in thermal energy storage, especially in thermal gradients due to it having both high E-ef and thermal conductivity.