超细颗粒膜包覆技术及装置研究——流化床喷雾热解法和流化床化学气相沉积法

【作者】 黄敏；

【导师】 刘宏英；

【作者基本信息】 南京理工大学 ， 材料学， 2004， 硕士

【摘要】 对超细颗粒进行膜包覆处理可显著增强其应用功效。为了实现切实可行的有效包覆过程，在国家自然科学基金和江苏省自然科学基金的资助下研究了超细颗粒膜包覆技术及相应装置。其一，提出以喷雾热解法和流化床喷雾干燥法相结合，研制出一种新的颗粒包膜技术——流化床喷雾热解法。自行研制了一套由提升管反应器、气固分离器和颗粒循环控制系统组成的循环流化床装置，其中，反应器配有喷雾及加热系统。以硝酸铁乙醇溶液和SiO₂颗粒为例进行了包覆试验。利用扫描电镜和X射线能谱仪等表征手段考察了包覆结果。在此基础上提出了实验改进方案。其二，对一种已有的、具有工业化前景的颗粒包膜技术——流化床化学气相沉积法进行了改进研究。采用传统流化床为反应器，配备了气态前驱体供应系统和尾气吸收系统。利用Ti（OC₄H₉）₄水解反应在SiO₂颗粒表面形成较均一、完整的钛化合物薄膜，同时初步研究了部分工艺参数的对产物性质的影响。更多还原

【Abstract】 As a part of the project supported by Chinese National Nature Science Fund and Jiangsu Provincial Nature Science Fund, investigations emphasizing on efficient particle coating technique were carried out to improve the application of ultrafine particles.Originated from spray pyrolysis and fluidization spray drying, fluidization spray pyrolysis was presented for coating thin film onto ultrafine particles. The self-made laboratory device was a circulating fluidized bed, consisting of reactor, gas-solid separator and control system of particle circulation. Experiments of particle coating were performed using ferric nitrate dissolved ethanol as coating layer precursor and SiO2 particles as kernel. Revised conception was discussed based on the analysis of coating result.Another particle coating method studied was fluidization chemical vapor deposition. The self-made laboratory coater was composed of chemical vapor precursor supply system, reactor (traditional fluidized bed) and effluent gas handling system. Titanium compound was deposited onto the SiO2 particles by the hydrolysis of Ti(OC4H9)4 in this device. The effects of partial chemical vapor deposition parameters on the coating result were discussed.更多还原