Multi-amine-functionalized cubic Fdm mesoporous silica by an anionic surfactant templating route

Abstract

Ordered multi-amine functionalized mesoporous silica with a 3D cubic Fdm mesostructure was synthesized with anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as a template, and [3-(2-aminoethyl)-aminopropyl]trimethoxysilane (DAPS) or 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane (TAPS) as co-structure directing agents (CSDAs). To our knowledge, this is the first time the use of DAPS and TAPS as CSDAs in an anionic surfactant templated system have been reported. Using DAPS and TAPS as the CSDA favors the formation of a 3D cubic mesocaged solid with Fdm symmetry, while with 3-aminopropyltriethoxysilane (APS) as the CSDA, only the p6mm mesoporous phase was formed. The geometrical change of the CSDA resulted in a change of the surfactant packing parameter, leading to the change of the silica mesophase from 2D-hexagonal p6mm to 3D cubic Fdm symmetry. After extraction of the templates, multi-amine-functionalized cubic Fdm mesoporous silicas were obtained. The multi-amine functionlized mesoporous silicas exhibit excellent properties in adsorption and removal of heavy metal ions in solution as well as the support of noble metal nanoparticles.