Synthesis and characterization of cubic periodic mesoporous organosilicas with a high loading of disulfide groups

Abstract

Well ordered cubic periodic mesoporous organosilicas (PMOs) with the SBA-1 motif containing a high loading of disulfide groups have been synthesized by simple co-condensation of bis[3-(triethoxysilyl) propyl]disulfide (BTEPDS) and tetraethoxysilane (TEOS) using the cationic surfactant cetyltriethylammonium bromide (CTEABr) as the template under acidic conditions. The materials thus obtained exhibited ordered and uniform mesopores up to 50 mol% of BTEPDS (based on silica) in the initial mixture. The successful incorporation of disulfide groups into the ordered mesopores was confirmed by ²⁹Si and ¹³C solid-state NMR spectroscopy. These disulfide-functionalized PMO materials showed good adsorption efficiency for Hg²⁺ ions. The successful conversion of the disulfide moiety to sulfonic acid functionality was also demonstrated by a simple post-oxidation method using hydrogen peroxide.