在超声波的促进作用下,以正硅酸乙酯为溶胶前驱体、硬脂酸为相变组分,经溶胶一凝胶过程制备了硬脂酸/SiO2复合定形相变储能材料。为了研究硬脂酸/SiO2复合定形相变储能材料的制备工艺,考察了不同超声功率对材料制备过程中加强两相传质作用的辅助效果的影响以及不同种类催化剂对材料制备过程中溶胶一凝胶过程的影响,最后确定出具有良好定形效果下材料的最大硬脂酸质量分数为60%。超声辅助酸碱复合催化法制备硬脂酸/SiO2材料具有无需添加助溶剂和表面活性剂、凝胶速度快、方法简便的优点。对硬脂酸/SiO2复合定形相变储能材料进行了FTIR结构表征和DSC、TG热性能及热稳定性测试,产品的相变焓值达91.46J/g,在低于175℃具有良好的热稳定性。
Stearic acid/SiO2 form-stable phase change material (PCM) was synthesized by sol - gel process under ultrasound assisted. Stearic acid acted as latent heat storage material, tetraethyl orthosilicate (TEOS) acted as silica precursor. In order to research the preparation process of the form-stable PCM, the sol- gel processes assisted by different ultrasound power and different kinds of catalyst were analyzed. At last, the maximum stearic acid loading mass fraction of hybrid PCMs with good form- stable character was found to be 60~. The formation process of stearic acid/SiO2 PCM has many advantages such as the whole process without any solvent or surfactant, fast gel formation and convenient preparation. The structure and thermal performance of stearic acid/SiO2 form-stable PCM were analyzed by FTIR, DSC and TG. The results show that the latent heat of stearic acid/SiO2 form-stable PCM is 91.46 J/g, and this material has a good thermal stability below 175℃.