Sol-gel synthesis, characterization and water vapor adsorption properties of 1,1′-(1,6-hexanediyl)-bis(imidazolium)dichloride-silica hybrid material

1,1'-(1,6-hexanediyl)-bis(imidazolium)dichloride-silica hybrid material was prepared in 90 % yield by ammonia catalyzed sol-gel condensation of 1,1'-(1,6-hexanediyl)-bis[3-(3-triethoxysilylpropyl)-imidazolium]dichloride in aqueous ethanol. This novel ionic liquid-silica hybrid material can adsorp 27 % w/w water vapor in 90 min at room temperature and atmospheric pressure. This is a higher water adsorption capacity and rate than commercial desiccant Drierite which showed only 16 % w/w of water vapor adsorption and required 10 h to reach the maximum adsorption under identical conditions. The new adsorbent could be reused for five cycles without any significant loss in activity after regeneration by heating at 110 A degrees C, for 24 h.