Diffusion and partitioning of macromolecules within finely porous glass

Measurements of diffusion and partitioning of nearly monodisperse polystyrene, having molecular weights of from 600 to 670,000, in chloro-form and dichloroethane and of two proteins in aqueous solution were made with leached borosilicate glass cubes having a narrow pore size distribution and pore radi of from 2.5 to 47.6 nm. With increasing ratio of molecular to pore size, the partition coefficient for all solutes decreased; the ratio of effective to bulk diffusivity decreased for the proteins but remained constant for polystyrene. This suggests that polystyrene behaved like a free-draining macromolecule under the conditions of this study.