Consequences of Tacticity on the Growth and Permeability of Hyperthin Polyelectrolyte Multilayers

A series of polyanions and polycations have been synthesized from atactic, syndiotactic, and isotactic forms of poly­(methyl methacrylate) and used to construct polyelectrolyte multilayers (PEMs). Polymer tacticity has been found to have a large influence on film growth but only a slight effect on H2/N2 permeation selectivities and no significant influence on CO2/N2 permeation selectivities. The permeances of H2, CO2, and N2 across those PEMs exhibiting the highest H2/N2 selectivities were found to vary by as much as factors of 3, 6, and 5, respectively, depending on the tacticities employed. A simple model that accounts for the strong dependency of film growth on tacticity is presented.