高岭土/二甲亚砜插层复合物脱嵌反应热动力学

采用TG和XRD研究了高岭土/二甲亚砜插层复合物的脱嵌反应过程, 提出了一种新的动力学计算方法. 首先用迭代的等转化率法求得反应的活化能Ea, 然后用Malek法拟合得到最可能的机理函数G(α)和f(α), 最后用多升温速率-等温法求得了指前因子A. 研究结果表明, 高岭土/二甲亚砜的插层物脱嵌反应的活化能Ea=86.65 kJ/mol, 指前因子A位于1.6050×108~3.6151×108 s-1之间. 其反应机理为n级的化学反应, 机理函数是G(α)=1-(1-α)1-n]/(1-n), f(α)=(1-α)n. n值和升温速率有一定的关系, 当升温速率较大(30 ℃/min)或较小(5 ℃/min)时, n=1.5, 当升温速率为7~25 ℃/min时, n=1.6.

Thermokinetics Study on the Deintercalation Reaction of Intercalating Composite Kaolinite/Dimethyl Sulphoxide

The de-intercalation processes occurring in the solid state Kaolinite/Dimethyl sulphoxide were stu-died by using TG and XRD techniques, and a new method of how to calculate the kinetic triplet was proposed on the thermokinetics study: Firstly, the activation energy Ea is calculated by interative procedure; secondly, the optimized methanism and the corresponding function G(α), f(α) is derived from the regression of Malek method; lastly, the pre-exponential factor A is estimated by multiple rates-isotemperature method. The apparent activation energy Ea of the decomposition of Kaolinite/Dimethyl sulphoxide is about 86.65 kJ/mol, and the pre-exponential factor A is 1.6050×108—3.6151×108 s-1, the optimized methanism is nth-order chemical reaction, the corresponding functions are G(α)=1-(1-α)1-n]/(1-n) and f(α)=(1-α)n. But the value of n has a relationship with the heating rate to a certain extent: when heating rate is rather quick(30 ℃/min)or rather slow(5 ℃/min), n is equal to 1.5, but when heating rate is between 7 and 25 ℃/min, n is equal to 1.6.