硅酸钠前体衍生SiO_(2)壳包覆高封装率相变胶囊的制备及性能

Preparation and properties of high encapsulation rate phase change capsules with silica shell derived from sodium silicate precursor

基于相变材料的热能储存技术是提升能源利用率、降低热能消耗、推动碳达峰碳中和目标实现的重要途径。以硅酸钠为二氧化硅壳前驱体,工业相变蜡材料为芯材,制备了一种高封装率相变胶囊。通过红外光谱(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)、差示量热(DSC)、热重(TG)等手段对相变胶囊的化学结构、微观形貌、相变性能以及热稳定性进行表征和测试。结果表明:制备了SiO_(2)壳包覆相变胶囊,当芯壳质量比为12∶1时,封装率高达81.5%,融化焓值和结晶焓值分别达138.0J/g和137.6J/g。而且相变胶囊具有良好的防泄漏性能和热稳定性。另外,热循环测试表明,即使经过200次循环,相变胶囊仍然表现出优异的循环稳定性。提出的相变胶囊制备技术具有成本低、封装率高和操作简便等优势,实际应用前景良好。

Thermal energy storage technology based on phase change materials is an essential way to enhance energy efficiency,reduce thermal energy consumption,and achieve the goal of carbon peak and carbon neutrality.A high encapsulation rate phase change capsule was prepared using sodium silicate as the silica shell precursor and industrial phase change wax as the core material.The chemical structure,microscopic morphology,phase change properties and thermal stability of the phase change capsules were characterized and tested by FT-IR,XRD,SEM,DSC,TG and other means.The results showed that the silica-encapsulated phase change capsules were successfully prepared.Moreover,the encapsulation rate was as high as 81.5%,and the enthalpy of melting and crystallization reached 138.0J/g and 137.6J/g,respectively,when the core-to-shell mass ratio was 12∶1.In addition,the phase change capsules exhibited good leak-proof performance and thermal stability.Furthermore,the thermal cycling test revealed that the phase change capsules still exhibited excellent cycle stability even after 200 cycles.The preparation technology of phase change capsules had the advantages of low cost,high encapsulation rate and easy operation,and also had good prospects for practical applications.