二氧化硅壁材包裹棕榈酸相变微胶囊的制备及性能研究

Preparation and properties of silica encased palmitic acid phase change microcapsules

以棕榈酸(PA)为芯材、九水合硅酸钠为硅源,在芯壁材质量比为1∶1、反应温度为70℃条件下,采用溶胶-凝胶法成功制备PA@SiO_(2)相变微胶囊。通过FT-IR、XRD、DSC及SEM等表征手段对相变微胶囊的组成、结构和相变性能进行分析。结果表明,芯材PA与壁材SiO_(2)之间仅仅只是物理结合,并未发生化学反应产生新的物质。制得的PA@SiO_(2)相变微胶囊具有典型的“核-壳”结构,球形粒子分散性良好,粒径较均匀;相变储热性能优异,包裹率可达87.5%。

PA@SiO_(2)phase change microcapsules are successfully prepared through the sol-gel method, with palmitic acid(PA) as core material, and sodium metasilicate nonahydrate as the silicon source when the mass ratio of core-shell material is 1∶1,and the reaction temperature is 70℃.The composition, structure, and thermal properties of the microcapsules are analyzed by means of Fourier transformation infrared spectroscope(FT-IR),X-ray diffractometer(XRD),differential scanning calorimeter(DSC),and scanning electron microscope(SEM).The results show that PA combines with SiO_(2)physically, without any chemical reaction happened and no new substances produced.The prepared PA@SiO_(2)phase change microcapsules have typical “core-shell” structure, in which spherical particles disperses well and have uniform particle size.It is found that PA@SiO_(2)phase change microcapsules have excellent performance of phase change heat storage, and the encapsulation rate is up to 87.5%.