Novel facile self-assembly approach to construct graphene oxide-decorated phase-change microcapsules with enhanced photo-to-thermal conversion performance
Novel facile self-assembly approach to construct graphene oxide-decorated phase-change microcapsules with enhanced photo-to-thermal conversion performance
复制标题
DOI：
10.1039/c8ta00215k
复制
发表时间：
2018-03
影响因子：
--
通讯作者：
Kunjie Yuan;Jian Liu;X. Fang;Zhengguo Zhang
中科院分区：
文献类型：
--
作者：
Kunjie Yuan;Jian Liu;X. Fang;Zhengguo Zhang
本研究制备了石蜡@混合纤维素自组装微胶囊和氧化石墨烯（GO）改性微胶囊。采用偏光显微镜、扫描电镜、红外光谱、X射线衍射和拉曼光谱对复合材料的微观结构和形貌进行了表征。结果表明，石蜡@乙基纤维素（EC）/甲基纤维素（MC）/GO复合材料由具有核@壳结构的球形颗粒组成，这表明核之间不存在化学反应（即，石蜡）和壳（即，EC/MC/GO）材料。熔化温度（即，49.7°C）和潜热（即，152.2J g-1）的石蜡@EC/MC/GO复合材料的热稳定性。DSC测试结果表明，石蜡在复合材料中的包封率可达85.4%。石蜡@EC/MC/GO复合材料在经历100次融冻循环后仍具有良好的相变性能，SEM观察表明该复合材料无渗漏。此外，将微胶囊分散到基础流体中（即，水）以形成稳定的悬浮液，其在30至80 °C的温度范围内显示出增强的光热转换性能。与石蜡@ EC/MC基相变浆料相比，石蜡@EC/MC/GO基相变浆料在较宽的温度范围内的效率保持在80%。石蜡@EC/MC/GO复合材料具有较高的储热容量、良好的热可靠性和增强的光热性能，在实际应用中具有良好的作为太阳能储热材料的潜力。
In this study, self-assembled and graphene oxide (GO) modified microcapsules of paraffin@mixed cellulose were prepared. The microstructure and morphology of the as-prepared phase-change composites were characterized by a polarizing microscope, SEM, FT-IR, XRD, and Raman spectrum. The results indicated that the paraffin@ethylcellulose (EC)/methylcellulose (MC)/GO composite consists of spherical particles that have core@shell structure, which indicates the absence of chemical reactions between the core (i.e., paraffin) and shell (i.e., EC/MC/GO) materials. The melting temperature (i.e., 49.7 °C) and latent heat (i.e., 152.2 J g−1) of the paraffin@EC/MC/GO composite were determined through DSC. The encapsulation rate of paraffin in the composite can be as high as 85.4% based on the results of the DSC measurement. The as-prepared paraffin@EC/MC/GO composites had no leakage, which was observed by SEM, and possess perfect phase-change capability after experiencing 100 melting–freezing cycles. Furthermore, the microencapsulation was dispersed into the base fluid (i.e., water) to form a stable suspension, which shows enhanced photo-thermal conversion performance with temperature range from 30 to 80 °C. The efficiency of paraffin@EC/MC/GO-based phase-change slurry is maintained at 80% in a wide temperature range compared with that of paraffin@EC/MC-based phase-change slurry. The paraffin@EC/MC/GO composite with high thermal storage capacity, good thermal reliability and enhanced photothermal performance exhibits a good potential for using as a solar thermal storage material in practical applications.