Restricted diffusion of highly dense starburst-dendritic poly(amido amine) in porous glasses

The dependence of hindered diffusion on the size ratio lambda sub(H), the ratio of the hydrodynamic radius of the macromolecule to pore radius, was studied for dendritic poly(amido amines) and linear polystyrenes in porous glasses. At low lambda sub(H), when hydrodynamic interactions dominate the diffusion, the dendritic polymers diffuse more slowly than do the linear polymers. The diffusion results for the dendritic polymer are in quantitative agreement with a hydrodynamic theory for a hard sphere in a cylindrical pore. The diffusion results for the linear flexible polymer chains are in qualitative agreement with a hydrodynamic theory for a random coil macromolecule in a cylindrical pore.