Characterization
The obtained dried powders were characterized using Differential Scanning Calorimetry (DSC) in a DSC 500 calorimeter from Waters using a constant heating rate of 2 °C/min from room temperature to 1000 °C; X-Ray Diffraction (XRD) patterns were obtained on a GBC-Difftech MMA model, with a Cu Ka irradiation at l= 1.54 Å; SEM micrographs were obtained using the secondary electrons detector in an Scanning Electron Microscope (SEM) Phillips XL-30. Transmission Electron Microscopy (TEM) analysis was performed on a JEOL JEM-1230 at an accelerating voltage of 100 kV. The infrared (IR) spectra were recorded in a FT-IR spectrometer Nicolet system model Avatar using the diffuse reflectance (DR) mode.
DSC and XRD analysis were performed using the asprepared powders after drying under atmospheric conditions. Samples for SEM observation were prepared by dispersing the powders in ethanol and immersing them in an ultrasonic bath for 5 min, few drops of the resulting suspension were placed onto a SEM specimen mount, dried in air and gold coated. Samples for TEM analysis were prepared by dispersing the powders in ethanol and immersing them in an ultrasonic bath for 5 min, few drops of the resulting suspension were placed onto a Formvar coated copper grid. Infrared (IR) absorption spectra were taken by the KBr method, for which 0.05 g of powder sample were mixed with 0.3 g of KBr.