Preparation and Characterization of SiO2-CaCl2 Nanocomposite by the Sol-Gel Method

The SiO2-CaCl2 hybrid porous materials were prepared by the sol-gel method. This process was conducted by the hydrolysis and condensation of Tetraethyl orthosilicate (TEOS) by replacement of ethanol from alcogel and drying at the ambient temperature to obtain xerogel structure. The alcogel samples were synthesized from TEOS, EtOH, H2O, HCl, NH4OH and CaCl2, while the total molar ratio of the compounds was 1: 9: 4: 8 x 10-4, 8 x 10-3, respectively. Xerogel containing 30 wt % of CaCl2 (dry matter) was prepared and characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Furier Transmittance Infra Red spectrum (FT-IR), Energy Dispersive X-ray (EDX) and Thermal Gravimetric Analysis (TGA ) systems. The results obtained from SEM and EDX showed the micrograph of CaCl2 on the silica and chemical elemental analysis, respectively. On the other hand, The TEM micrograph confirmed average particle size of SiO2-CaCl2 about 50 nm and FT-IR spectrum described the functional groups of the nanocomposite. The thermal analysis of SiO2-CaCl2 nanocomposite was performed using TGA system and the results showed that the suitable temperature for initial thermal treatment was about 200°C.