Effective inorganic hybrid adsorbents of water vapor by the sol-gel method

The SiO2/CaCl2 hybrid porous materials were obtained by the two-step hydrolysis and condensation of tetraethoxysilane with (a) replacement of ethanol from alcogel by supercritical CO2 to obtain aerogel morphology and (b) drying alcogel at ambient to obtain xerogel structures. Aerogels and xerogels containing similar to 17 and 30 similar to wt % of CaCl2 (dry matter) were prepared and investigated for adsorptivity of water vapor to obtain sorption capacities in excess of 1 kg of water/kg of adsorbate. The adsorbates obtained can be dried and reused. No notable loss in adsorption capacity was observed during 50 cycles.