Thin-layer chromatography in the investigation of polystyrene macromolecule interaction with nanoporous silica

The behavior of polystyrene macromolecules in nanopores of silica (silica gel, silochrome, MPS porous glass) is studied by a method of thin-layer chromatography. Tetrahydrofuran (THF) and a mixture of benzene with cyclohexane are used as solvents in this work. The relative coefficient of retardation (capacity coefficient) k' and the distribution coefficient of polystyrene macromolecules between two phases K (p) are calculated from R (f) values. THF elution is characterized by a negative adsorption of polystyrenes because of preferential adsorption of solvent molecules and different availability of sorbent pore volume for macromolecular coils of polystyrenes. The calculated values R (f) > 1, k' < 0, and K (p) < 1 reflect the mode of negative sieve chromatography and formation of monolayer of THF molecules adsorbed on the sorbent surface. The ratios between the retardation parameters in thin-layer and column chromatography are considered. The influence of the sorbent pore sizes and polystyrene molecular weights on the parameters of thin-layer chromatography is discussed.