机构地区: 广东工业大学轻工化工学院
出 处: 《无机盐工业》 2005年第3期8-10,49,共4页
摘 要: 研究了水热法制备纳米二氧化锆过程中,制备前驱物的投料比n(NH3·H2O)∶n(ZrOCl2·8H2O)、水热反应的温度及保温时间对平均粒径dXRD及结晶率Xc的影响,研究结果表明:随着反应温度提高,晶体生长速率增大,晶化率提高,同时平均晶体粒径增大;水热时间延长,晶化率上升。其动力方程用Avrami动力学方程表示,分别求出在水热温度为 180℃时,动力学方程为ln[-ln(1-Xc) ] =ln1.28+0.578lnt;当水热温度为 240℃时,动力学方程为ln[-ln(1-Xc) ] =ln1.80+0.327lnt;当保温时间≥1h时,方程计算结果与实测数据基本吻合,其相对误差≤2. 6%。 The effects of ratio of the precursor[n(NH_3·H_2O)∶n(ZrOCl_2·8H_2O)],reaction temperature,and heat-keeping time on the average particle size d_(XRD) and crystallinity Xc in the preparation of nanometer zirconium oxide by hydrothermal method are studied.The results of the test show that with the raise of reaction temperature,the growth velocity of crystal will be increase and the crystallinity will be promoted.Meantime,the average crystal size will be larger and the hydrothermal time will be prolonged and the crystallinity will be increased.The kinetic equation can be expressed as Avrami equation.When the hydrothermal temperature is at 180 ℃,the kinetic equation is ln\[-ln(1-Xc)\]=ln1.28+0.578(lnt;)while at 240 ℃,the equation is ln\[-ln(1-Xc)\]=ln1.80+0.327lnt.When the heat-keeping time≤1 h,the calculated value is basically in accordance with the data determined by the test,the relative error is ≤2.6%.
领 域: [化学工程]