A comparative study of the functionalization of mesoporous silica MCM-41 by deposition of 3-aminopropyltrimethoxysilane from toluene and from the vapor phase

The postsynthetic functionalization of mesoporous silica MCM-41 by vapor phase deposition of 3-aminopropyltrimethoxysilane is investigated as an alternative to the common practice of depositing from toluene. Particular emphasis is given to the possibility of eliminating the influence of trace water upon deposition from the vapor phase. The comparative study of samples prepared by different deposition methods requires identical degrees of functionalization. To obtain reliable information on the amount of surface-grafted aminopropyl groups, we have developed an analysis procedure based on the fluorogenic amine-derivatization reaction of fluorescamine.