| The increasingly stringent environmental regulations worldwide demand the use of efficient methods for air purification. This work is a contribution toward developing efficient adsorbents for volatile organic compounds (VOCs). Three different varieties of ordered mesoporous silicas were evaluated: an ordered MCM-41 mesoporous silica prepared in the presence of a surfactant, a MCM-41 whose pores have been expanded by a post-synthesis hydrothermal treatment in the presence of an organic expander (referred to as MCM-EC), and a pore-expanded hybrid mesoporous silica produced by the selective extraction of its pore expander agent (denominated MCM-EE). With the intention to analyze their performance as adsorbents, the heat of adsorption (-DeltaHa) and adsorption capacity (q) were determined experimentally for five typical VOCs: dichloromethane, chloroform, benzene, toluene and cyclohexane. (Abstract shortened by UMI.)... |