Spectroscopic Characterisation of Mesoporous Materials

Commercially available inorganic solids and organically functionalised silicas and silica-polysaccharide composite materials synthesised in the laboratory were characterised by various techniques. These included direct infrared spectroscopic measurements, infrared and UV-visible probing techniques using probe molecules such as water, ammonia, d3-actonitrile, aniline, Reichardt’s dye and iodine and also by the application of the Knoevenagel condensation as a model reaction. As well as the information obtained about the surface activity of the solids, this review of techniques revealed the advantages and limitations of well-known and less frequently used methods. In particular, the use of iodine as a UV-visible probe molecule allowed the observation of differences between materials that are extremely difficult to analyse such as sodium carbonate and sodium acetate. However with current levels of knowledge about the electronic transitions of iodine adsorbed on surfaces, the results are not straight forward to interpret. The silica-polysaccharide composites also showed interesting properties, both in terms of their morphology and their chemistry and merit further study.