Photoacoustic infrared spectroscopic studies of silica gels with organically functionalized surface

The article shows the application of photoacoustic Fourier transform infrared spectroscopy as a tool for identification of signal characteristics of organic ligands immobilized at the silica gel. Each of the compounds studied had an alkyl chain. Therefore, the differences could be observed on the basis of the position (wavenumbers) and appearance of bands typical of the carbon-hydrogen stretching vibrations. However, an important observation was that depending on the organic unit at the silica surface, it was possible to easily distinguish between signals specific to the ligand. The only exception was the system with functional groups whose signals coincided with the bands typical of inorganic silica.