基于聚多巴胺包覆的光热相变纳胶囊的制备及性能

以正十八烷（n-OD）为芯材，二氧化硅（SiO2）和聚多巴胺（PDA）为复合壁材，采用界面水解缩合法成功制备光热相变微胶囊n-OD@SiO2/PDA。采用FESEM、FETEM、FTIR、DSC、TG、UV-Vis-NIR和模拟光源等对所制备微胶囊的表面形貌、化学结构、热性能、光吸收性能和光热转换性能进行了分析和表征。在探究了不同芯材与硅源（正硅酸四乙酯）质量比对相变微胶囊储热性能影响的基础上，确定了以m(n-OD):m(TEOS)为2:1制备光热相变微胶囊。实验结果表明，所制备的光热相变微胶囊具有规整的表面形貌和明显的核壳结构，具有良好的耐热性能，复合壁材可以有效保护芯材。与相变微胶囊n-OD@SiO2相比，光热相变微胶囊仍具备良好的储热性能，其熔融热焓值为151.2 J/g，展现出较好的光热转换性能，其光热转换与存储效率为91.8%。

Preparation and properties of PDA-coated photo-thermal phase change microcapsules

Photothermal phase change microcapsules (n-OD@SiO2/PDA) were successfully prepared using n-octadecane (n-OD) as core material, silica (SiO2) and polydopamine (PDA) as composite wall materials. FESEM, FETEM, FTIR, DSC, TG, UV-Vis-NIR and simulated light source were used to characterize the surface morphology, chemical structure, thermal properties, optical absorption and photothermal properties of the microcapsules. The effect of different mass ratios of core material to silicon source (tetraethyl orthosilicate, TEOS) on the thermal storage performance of phase change microcapsules was investigated. The optimal mass ratio of n-OD to TEOS was 2:1. The results showed that the prepared photo thermal phase change microcapsules had regular surface morphology and obvious core-shell structure with good heat resistance, and the composite wall material could effectively protect the core material. Compared with the phase change microcapsules n-OD@SiO2, n-OD@SiO2/PDA had good heat storage performance with a melting enthalpy of 151.2 J/g, and exhibited excellent photothermal conversion performance with 91.8% of solar thermal conversion and storage efficiency.