溶剂热合成SDBS修饰氢氧化镁的热分解动力学研究  

Study on Synthesis and Thermal Decomposition Kinetics of Mg(OH)_2 Modified with SDBS by Solvent-Thermal Method

作　　者：司伟[1] 丁超[2] 于景媛[3] 

机构地区：[1]大连交通大学料科学与工程学院辽宁省无机超细粉体制备及应用重点实验室,大连116028 [2]大连市环境监测中心,大连116023 [3]辽宁工业大学材料科学与工程学院,锦州121001

出　　处：《人工晶体学报》2013年第11期2384-2389,共6页Journal of Synthetic Crystals

基　　金：国家自然科学基金(51308086);国家863计划资助项目(2011AA060102);辽宁省教育厅资助项目(L2012161)

摘　　要：以MgCl2·6H2O、NH3-H2O原料，分别使用液相沉淀法合成氢氧化镁粉体及以乙醇／水为溶剂，使用溶剂热法合成十二烷基苯磺酸钠（SDBS）修饰的氢氧化镁粉体，利用不同升温速率的热重及差热分析研究两种方法制备氢氧化镁的热分解动力学。研究表明，两种氢氧化镁在560～700K均有一个明显的吸热峰，利用Doyle．Ozawa法和Kissinger法分别计算了两种氢氧化镁的表观活化能，用Kissinger法确定反应级数和频率因子，并给出了氢氧化镁热分解的动力学方程。使用液相沉淀法合成的氢氧化镁的平均表观活化能为157．18kJ·mol-1，而溶剂热合成SDBS修饰氢氧化镁的平均表观活化能高达175．66kJ·mol-1。The magnesium hydroxide and Mg （OH）2 modified with SDBS （sodium dodecyl benzene sulfonate） powder was synthesized using MgC12 ·6H2O and NH3 · H2O as raw materials by liquid-phase precipitation and solvent-thermal method, respectively. The thermal decomposition kinetics of two kinds of Mg（OH） 2 were investigated using TG-DTA at different heating rates in argon gas. The results showed that all these two kinds of Mg（OH）2 have one obvious endothermic peak at 560-700 K. The apparent activation energy of two kinds of Mg（OH）2 were calculated using the Doyle-Ozawa and Kissinger methods, and the coefficients of reaction order, frequency factor and kinetic equations were also determined. The average apparent activation energy for the Mg（OH） 2 modified with SDBS was calculated to be 175.66 kJ· mol- 1 by solvent-thermal method higher than that in Mg（OH）2 by liquid-phase precipitation （157.18 kJ · mol-l）.

关 键 词：溶剂热法 氢氧化镁 热分解动力学 结晶性能 

分 类 号：O643.1[理学—物理化学]