【摘要】 利用硅藻土比表面积大、孔洞多因而吸附性好的特点,吸附正十八烷,制备出形态稳定、高相变焓的硅藻土/正十八烷复合相变材料。利用扫描电镜(SEM)观察其表面形貌,采用红外光谱法(FTIR)分析材料的微观结构,用热重分析仪(TG)及受热形态变化对其热稳定性进行了表征,用示差扫描量热法(DSC)对其相变温度及相变焓进行了测定。结果表明:制得的复合相变材料的分解温度在240℃以上,当正十八烷的吸附量不超过40%时,在高于相变温度时未泄漏,相变温度在26~31℃之间,并且具有很高的相变焓(131.6~163.3J/g),是一类形态稳定、相变焓高、热性能良好、应用前景广泛的节能环保材料。更多还原

【Abstract】 Diatomite has some advantageous properties such as large specific surface,porous structure and therefore high adsorption capacity.The phase-change materials with stable form and high phase-transition enthalpy were prepared.Scanning electron microscopy(SEM)was used to observe the surface morphology of the materials.The microstructure was analyzed by fourier transform infrared spectroscopy(FTIR).Thermogravimetry(TG)and differential scanning calorimetry(DSC)were used to determine the thermal stability,phase-change temperature and phase-transition enthalpy.Phase-change materials with stable form and high decomposition temperatures above 240℃could be obtained.If the adsorbed quantity of n-octadecane is less than 40%,the phase-change materials do not show any leakage at temperatures above the phase-change temperature.The phase-change temperatures of the composite phase-change materials lie in the range of 26-31 ℃ and the phase-transition enthalpy is at a high level(131.6-163.3J/g).With their form stability,high phase transition enthalpy and excellent thermal behavior these phasechange composite materials exhibit high potential for the application as energy saving materials.更多还原