Synthesis and characterization of sol–gel mesoporous organosilicas functionalized with amine groups

Abstract

In this work we report on the synthesis of porous amine functionalized organosilica materials prepared by co-condensation of tetraethyl orthosilicate (TEOS) and bis-[3-(trimethoxyosilyl)propyl] amine (BTPA). The gels were prepared through a one-step sol–gel process catalyzed by the NH groups of BTPA. A block copolymer poly(ethylene glycol)–block-poly(propylene glycol)–block-poly(ethylene glycol) (P123) was employed as a porogen using the surfactant template method. The resultant materials have been characterized by nitrogen gas sorption, powder X-ray diffraction, FT-IR, SEM, 29Si MAS NMR, 13C CP MAS NMR and TG/DTA analysis. In order to examine the potential of these materials as adsorbents for heavy metals, Hg(II) adsorption experiments were also performed. The hybrids showed mesoporous disordered structure as evidenced by N2 adsorption–desorption isotherms and XRD patterns. Adsorption of Hg(II) ions from aqueous solutions showed high capacities suggesting that these materials could be used as adsorbents for Hg(II) ions in acid solutions.