Abstract
This work reports the covalent attachment of three different calix[4]arenes (calix[4]arene (C4), p-sulfonatocalix[4]arene (C4S), and p-tert-butyl-calix[4]arene (PC4)) to MCM-41, using a three-step modification process. 3-Chloropropyltrimethoxysilane (ClPTS) was first attached to the mesoporous silica surface and subsequently converted to amides via the reaction with toluene diisocyanate (TDI). Finally, calix[4]arene derivatives attached to the isocyanate ending remained available on toluene di-iso-cyanate. Changes in the surface properties of the mesoporous silica caused by the chemical modification were monitored using the Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA), and elemental analysis. The FTIR spectra and TGA analysis verify that the calix[4]arene derivatives are covalently attached to the mesoporous silica. The preservation of the MCM-41 channel system was checked by the X-ray diffraction and nitrogen adsorption analysis. These materials were then used to evaluate the sorption properties of some organotins compounds (Tributyltin (TBT), Triphenyltin (TPT), and Dibutyltin (DBT)).