Transport in polymer/gel-modified micropores

The ability of a membrane to separate molecules can be improved by introducing a polymer network in its pores. In this work two different polymer composite membranes were used: (1) membranes with polymer adsorbed to the pore walls and (2) membranes with crosslinked polymer gel synthesized in the pores. Polymer layers formed from adsorption only partially fill the pores, while the crosslinked gel network completely fills the pores.;The absorbed polymer layers consisted of either a diblock copolymer or a homopolymer containing n-butyl methacrylate. The apparent thickness of the polymer was determined by measuring the reduction in solute and solvent transport compared to bare pores. Pressure driven flows of pure solvent gave one such apparent layer thickness, L;The polyacrylamide gel composite membranes that were used for this work had varying polymer volume fraction (;Current theoretical models for uniform networks underpredict the experimental results for the transport coefficients. Some of this discrepancy can be accounted for by chemical crosslinks and the resulting concentration heterogeneities in the gel.