EVALUATING DISPERSION IN GEL PERMEATION CHROMATOGRAPHY - AXIAL DISPERSION OF POLYMER MOLECULES IN PACKED BEDS OF NONPOROUS GLASS BEADS

The causes of zone broadening in GPC columns can be attributed to free-stream dispersion (outside the gel) and broadening due to the permeation process itself. Free-stream dispersion in the absence of permeation was studied utilizing nonporous glass beads and solutes covering a wide range of diffusivity. The major variables examined were flow rate, solute diffusivity, and particle size and size distribution of the packing beads. The experimental data are in good agreement with the theoretical model previously proposed, which incorporates molecular diffusion, eddy diffusion, and velocity-profile effects as the major causes of axial dispersion. Particle segregation effects were shown to be relatively unimportant. © 1969, American Chemical Society. All rights reserved.