Publication
Title
Special data handling techniques for Fourier-transform infrared photoacoustic spectra : estimation and characterization of the N contents on ammoniated trichlorosilylated silica-gel, using partial least-squares regression and curve fitting on the Si-H stretching vibration
Author
Abstract
The reaction of silica gel with trichlorosilane (HSiCl3) and subsequently with gaseous NH3, resulting in a surface covered with =Si-O-Si(H)(NH2), and NH4Cl species, has been studied. The Si-H stretching vibration (2270 cm-1) of the trichlorosilylated silica perturbs, upon ammonia adsorption, into three overlapping bands. It is shown that partial least-squares regression (PLSR) is able to predict the concentration of the different surface species, using the Si-H stretching vibration region as the only spectral dataset. It is noticeable that this vibration has a constant intensity, since the Si-H species are generated during the trichlorosilylation step, and not during the ammoniation. The mechanisms, causing this perturbation are investigated in more detail, using curve fitting and Si-29 cross-polarisation magic-angle-spinning (CP MAS) NMR. The occurrence of an ammoniated secondary species [(=Si-O),-Si(H)(NH2)] on the silica surface is proposed and its infrared (IR) absorbing frequency is determined. An introduction to PLS for the spectroscopist is included.
Language
English
Source (journal)
Journal of the Chemical Society: Faraday transactions: physical chemistry and chemical physics / Chemical Society [Londen] - London
Publication
London : 1993
ISSN
0956-5000
Volume/pages
89:1(1993), p. 63-68
ISI
A1993KH27700011
Full text (Publisher's DOI)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 03.01.2013
Last edited 10.06.2017
To cite this reference