二氧化硅气凝胶的表面改性及热稳定性的研究

Studies on the Surface Modification and Thermal Stability of Silica Aerogels

采用溶胶-凝胶法在常压下经三甲基氯硅烷改性后成功制备出了疏水性二氧化硅气凝胶,并通过红外光谱(IR)、接触角的测定和差热-热重(DTA-TG)分析方法对二氧化硅气凝胶改性前后的化学成份、疏水性能和热稳定性进行了研究.结果表明,经改性后的样品确实为疏水性二氧化硅气凝胶,热稳定性良好,可承受1 100℃的高温,足以满足航空、航天以及民用工业中对超级隔热保温材料的要求.

Hydrophobic silica aerogels had been prepared successfully under ambient pressure by sol-gel method after being modified by trimethylchlorosilane（TMCS）. The fore-and-aft chemical composites, hydrophobic property and thermal stability of the modified siica areogels had been studied by the IR, DTA-TG spectrogram and the determination of contact angle. The results showed that the modified samples were certainly hydrophobic silica aerogels with higher thermal stability which could support the highest temperature of 1 100 ℃, which will be enough to satisfy the demands to the super heat insulation and heat preservation of materials in the fields of avigation, spaceflight, civilian technology and industry.