Adsorption of aniline onto hexagonal mesoporous silicate monoliths (HOM-2)

Hexagonally highly ordered monolithic mesoporous silica and aluminosilicate composites (HOM-2 and Al/HOM-2, respectively) were used as adsorbents for removal of aniline in aqueous solution. These HOM-adsorbents were fabricated by using a simple, reproducible and direct synthesis strategy in which instantly preformed liquid crystalline phase of Brij 56 (C₁₆EO₁₀) surfactant was used as templates. Extensive characterisation studies showed that Al/HOM-2 composites revealed higher surface area, smaller pore sizes and thicker pore wall than those of unloaded-HOM-2 monoliths, indicating that Al might be impregnated into the inner pores and the wall frameworks of HOM-2 silica monoliths. The adsorption experiments of aniline were investigated by using batch techniques. The results obtained showed that the aniline molecule strongly adsorbed onto the aluminosilicate mesostructures. In addition, the HOM-adsorbent exhibited high efficiency for aniline removal after several uses without loss of structural ordering, permitting the reusability for further selective separation of organic molecules from water.