Abstract:

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 E_a 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 E_a 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.

Key words: Kaolinite/dimethyl sulphoxide, Interative procedure, Malek method, Multiple rates-isotemperature method, Thermokinetics