Preparation of 3,3,3-trifluoropropyl functionalized hydrophobic mesoporous silica and its outstanding adsorption properties for dibutyl phthalate

Abstract

In this study, 3,3,3-trifluoropropyltrimethoxysilane was first used as a modification agent to synthesize a highly hydrophobic mesoporous silica, TFP-MCM-41, using a refluxing method. The adsorption properties of TFP-MCM-41 for dibutyl phthalate (DBP) were studied by comparing its properties with that of the n-propyl-functionalized form of MCM-41, P-MCM-41, which contains three C-H bonds at the end of the organic chain instead of C-F bonds as in 3,3,3-trifluoropropyltrimethoxysilane, and unmodified MCM-41. TFP-MCM-41 showed much stronger hydrophobicity, higher adsorption affinity and better selectivity for adsorption of DBP than either P-MCM-41 or MCM-41. TFP-MCM-41 could preferentially uptake DBP from an aqueous solution containing a trace of DBP and large amounts of phenol. The excellent adsorption affinity and selectivity for DBP displayed by TFP-MCM-41 were ascribed to the hydrophobic and hydrogen bond interactions between the 3,3,3-trifluoropropyl groups and DBP molecules.