The structure investigations of polysaccharide-polyimine encapsuled siliceous materials

Forming a polymer layer on the surface of siliceous supports for chromatography is one of the methods for protecting the silica skeleton from dissolution in alkaline mobile phases as well as eliminating the negative influence of silanol groups on separated molecules. Polysaccharide-polyimine copolymers can play the role of the surface layer, especially in siliceous materials for high performance affinity chromatography. The porous structure of materials with surface polymer layer is different from that for initial material which supports the layer. The paper deals with the applicability of: mercury porosimetry, size exclusion chromatography (SEC), thermogravimetry (TG), small angle Xray scattering (SAXS), for the structure characterization of the system consisting of siliceous support with dextran-polyimine layer. The results obtained show that despite of the presence of a rigid siliceous core supporting the polymer layer, the structure of such sorbents should be examined by the methods preferred for the investigation of soft polymers, e.g. SEC, TG, SAXS.