TOTAL CHARACTERIZATION OF THE BCL3-MODIFIED SILICA SURFACE BY MEANS OF QUANTITATIVE SURFACE-ANALYSIS

The reaction of boron trichloride (BCl3) with a well characterized silica surface has been studied using Fourier-transform IR photoacoustic spectroscopy (FTIR-PAS) and quantitative boron and chloride analyses. Isolated and vicinal silanol groups, in addition to surface siloxane bridges, react with BCl3, resulting in the formation of chemisorbed monodentate or didentate surface groups. The parameters influencing the relative occurrence of these surface species have been investigated. A quantitative description of the grafted groups and reacted silanols has been obtained as a function of the pretreatment temperature of the silica, the reaction temperature and the reaction time.