从柠檬酸前驱体合成超细氧化铝及莫来石粉末

Ultrafine Alumina and Mullite Powders Synthesized from Citrate Polimeric Precursor

以硝酸铝作为铝源、硅溶胶作为硅源、柠檬酸作为稳定剂,通过简单的溶胶-凝胶过程合成超细氧化铝及莫来石粉末。通过X-射线衍射分析(XRD),扫描电子显微镜(SEM)和红外(IR)光谱以最终产物进行分析与表征。XRD结果显示铝凝胶粉经1200℃煅烧2h后样品由α-Al_2O_3晶相的氧化铝构成,而铝硅凝胶粉经1200℃煅烧2 h后样品由斜方结构的莫来石构成。SEM图像显示所得样品为无规则形态,高温煅烧引起粉末的团聚。

Ultrafine alumina and mullite powders have been synthesized by a simple sol-gel process using aluminium nitrate as the aluminum source,silicon sol as the silicon source and citrate as the stabilizing agent. X-ray diffraction（XRD）,scanning electron microscopy（SEM） and infrared spectroscopy（IR） were used to characterize the heat-treated final powders.XRD results show that the alumina sample sintered at 1 200℃for 2 h consists ofα-Al_2O_3 phase and the mullite sample sintered at 1 200℃for 2 h is mainly composed of orthorhombic mullite phase.SEM results display that the obtained powders are irregular.The aggregation of the powders is caused by the high temperature.