中文摘要：

以石蜡为相变芯材,以正硅酸乙酯为硅源,在酸性条件下通过溶胶-凝胶法制备出石蜡/二氧化硅复合相变材料.应用傅里叶红外光谱、X射线衍射、扫描电镜、差示扫描量热法、热重法等手段对所制备复合相变材料的形貌、成分、热性能等进行了表征.实验结果表明,所制备的石蜡/二氧化硅复合相变材料的形貌是直径约为2μm的核/壳结构微球.当核/壳质量比为2∶1时,石蜡包覆率为66.3%,熔点为54.2℃,熔化焓为133.8 J·g-1,凝固点为49.5℃,凝固焓为127.5 J·g-1.与传统的有机高分子壳层材料相比,无机二氧化硅壳层材料具有更好的热导率,提升了复合相变材料的导热性能,且其不易燃烧,无腐蚀性,更加安全环保,有效拓展了相变材料在建筑保温和智能保温纺织物等领域的实际应用.

英文摘要：

Paraffin / Si O2 composite phase change materials based on a paraffin core and a silica shell were prepared using TEOS as a silica source through a sol- gel method under acidic condition. Fourier transformation infrared spectroscopy,X-ray diffraction,scanning electron microscopy,differential scanning calorimetry and thermogravimetry were employed to investigate the morphology,chemical structure,crystalloid phase,phase change properties and thermal stability of the composite materials. The results show that the paraffin / Si O2 materials have core / shell morphology with a diameter of about 2 μm. When the core / shell mass ratio reaches 2 ∶ 1,the encapsulated ratio of paraffin is 66. 3%,the melting point of the composites is 54. 2 ℃ with a latent heat of 133. 8 J·g- 1,and the solidifying temperature is 49. 5 ℃ with a latent heat of 127. 5 J·g- 1. In comparison to traditional composite phase change materials with a polymeric shell,the thermal conductivity of the paraffin / Si O2 materials increases due to the extra silica shell. This advantage expands applications in building materials and textile fabrics.