包覆SiO2的硬脂酸相变储能材料的低热固相化学合成及其热性能

采用低热固相化学反应法,一步制备了表面包覆SiO2的硬脂酸相变储能纳米粒子.由红外光谱、X射线衍射和差示扫描量热法对表面包覆SiO2的硬脂酸纳米粒子进行了表征.利用动态光散射激光力度仪测定了材料的粒径分布,同时对材料表面包覆前后的接触角进行了测定.结果表明:硬脂酸纳米粒子表面成功包覆了SiO2层.包覆的硬脂酸纳米粒子为球状,粒径大约为110 nm.包覆的硬脂酸纳米粒子相转变温度为61.4℃,相变过程中的焓值为153.1 J/g,具有良好的蓄热能力,可用于太阳能利用等方面的储能蓄热.

PREPARATION AND THERMAL PROPERTIES OF SiO2 COATED STEARIC ACID PHASE CHANGE MATERIALS BY LOW-TEMPERATURE ONE-STEP SOLID-STATE CHEMICAL REACTION

The synthesis of SiO2 coated stearic acid (SA) nanoparticles via one-step, low heating temperature solid-state chemical reaction is reported. Analytical results of infrared spectroscopy and X-ray diffraction indicate that the SA was coated with a layer of SiO2. The morphology revealed by scanning electron microscopy suggests that the samples were comprised of sphere-like nanoparticles with an average diameter of about 110 nm. The particle size distribution of the samples and the contact angles were determined by dynamic light scattering and a contact angle system. The as-prepared samples were studied with differential scanning calorimetry.The phase transformation temperatures is 61.4 ℃and the fusion enthalpy is 153.1J/g. The results show that the samples possess reasonable thermal properties as phase change materials for latent heat storage.