High-temperature Chemical And Microstructural Transformations Of An Organic-inorganic Nanohybrid Captopril Intercalated Mg-al Layered Double Hydroxide

摘要

The thermal evolution of a crystalline organic-inorganic nanohybrid captopril intercalated Mg-Al layered double hydroxide (LDH) [Mg_(0.68)Al_(0.32)(OH)_2] (C_9H_(13)NO_3S)_(0.130)(CO_3)_(0.030)·0.53H_2O obtained by coprecipitation method is studied based upon in situ high-temperature X-ray diffraction, in situ infrared and thermogravimetric analysis coupled with mass spectroscopy analysis. The results reveal that a metastable quasi-interstratified layered nanohybrid involving carbonate-LDH and reoriented less ordered captopril-LDH was firstly observed as captopril-LDH heat-treated between 140 and 230 C. The major decomposition/combustion of interlayer organics occur between 270 and 550 C. A schematic model on chemical and microstructural evolution of this particular drug-inorganic nanohybrid upon heating in air atmosphere is proposed.