Self-assembly of layered functionalized hybrid materials. A good opportunity for extractive chemistry

This paper is devoted to layered hybrid organic-inorganic materials obtained by self-assembly of organosilica precursors during the hydrolytic sol–gel process. The self-assembly is induced by lipophilic van der Waals interactions between alkylene chains. The introduction of functional groups such as –SS– gives rise to –SH or –SO3H functionalized materials after chemical modifications. This methodology has been extended to the formation of lamellar hybrid materials containing amino groups thanks to CO2 as bridging groups as well as the formation of lamellar hybrid materials containing carboxylic groups. In this last case, the material was elaborated thanks to in situ hydrogen bond formation between carboxylic acid groups. An easy preparation of bis-zwitterionic lamellar material from only 3-aminopropyltriethoxysilane, succinic anhydride, and ethylene diamine will be also presented. All these functional materials exhibit a very high chelating capability towards transition metal and lanthanide ions and can be used for environmental remediation.