Influence of the alcoholic solvent and gelation temperature on the structural and water vapor adsorption properties of silica adsorbents synthesized by sol-gel method without catalyst

Silica adsorbents with controlled porosity were produced by sol-gel technique without using catalyst. Mesoporosity and water vapor adsorption properties were evaluated for the synthesized silica materials. This study was supported by several characterizations, including FTIR, SEM and Nitrogen sorption. It has been shown that the mesoporous structure and the water adsorption performance of the silica are entirely dependent of the solvent type used and gelation temperature. The present study shows that for the adsorption parameters used in this work, the control of the sol-gel parameters can give rise to silica adsorbents with greater adsorption capacity than the commonly used commercial silica. The highest adsorption capacities were measured for silica structures synthesized with tert-butanol and gelled at 90 degrees C, which absorbs up to 65% more than its mass due to both high mesopore volume and big pore size. The silica materials were synthesized in this work by a simple sol-gel synthesis, which represents an important advantage in terms of safety and environmental sustainability, besides reinforcing the simplicity and novelty of the processing route employed herein to obtain silica adsorbents with a controlled porous structure.