Novel segregated-structure phase change materials composed of paraffin@graphene microencapsules with high latent heat and thermal conductivity
Novel segregated-structure phase change materials composed of paraffin@graphene microencapsules with high latent heat and thermal conductivity
复制标题
高潜热高导热石蜡@石墨烯微胶囊新型偏析结构相变材料
DOI：
10.1007/s10853-017-1693-2
复制
发表时间：
2018-02-01
影响因子：
4.5
通讯作者：
Zhang, Kai
中科院分区：
文献类型：
--
作者：
Yang, Wenbin;Zhang, Li;Zhang, Kai
石蜡由于其线性链和导热系数低的饱和烃，很难有效地传递能量。利用氧化石墨烯（GO）的两亲性，得到paraffin@GO的Pickering乳液，然后通过加入水合肼进行化学还原得到paraffin@graphene微囊化相变材料（MEPCMs）。通过对paraffin@graphene微胶囊进行热压缩，制备了具有分离结构的导热pcm。采用扫描电镜、差示扫描量热法和导热系数测试对mepcm的微观结构和热性能进行表征。同时，研究了石墨烯对相变潜热和相变温度的影响。结果表明，氧化石墨烯在化学还原过程中未与石蜡发生反应，制备的mepcm为规则球状。这些mepcm的石蜡含量达到99%甚至更高。石墨烯作为壳材料，在不影响相变温度的情况下，使石蜡相变潜热由227.6 J/g提高到232.4 J/g。热压成型使石墨烯壳形成具有更多热通道的分离结构，进一步提高导热性。具有高潜热和高导热性能的分离结构相变材料可应用于储能领域。
Paraffin, due to its linear chain and saturated hydrocarbons with low thermal conductivity, is difficult to transfer energy effectively. Using amphiphilicity of graphene oxide (GO), Pickering emulsion of paraffin@GO was obtained and then paraffin@graphene microencapsulated phase change materials (MEPCMs) were achieved by chemical reduction through adding hydrazine hydrate. Thermally conductive PCMs with segregated structure were constructed by hot compression of paraffin@graphene microencapsules. Scanning electronic microscopy, differential scanning calorimetry and thermal conductivity test were used to characterize microstructure and thermal properties of MEPCMs. Meanwhile, the effect of graphene on the phase change latent heat and phase transition temperature was investigated. Results indicated that GO did not react with paraffin during the process of chemical reduction and the obtained MEPCMs were regular spheres. These MEPCMs had paraffin content of 99% or even more. Graphene working as shell materials increased the phase change latent heat of paraffin from 227.6 to 232.4 J/g, without affecting the phase transition temperature. The hot-compress molding makes graphene shell form segregated structure with more thermal pathways, further enhancing thermal conductivity. The segregated-structure PCMs with high latent heat and thermal conductivity can be applied in energy storage field.