Membrane design for pervaporation or vapor permeation separation using a filling-type membrane concept

A new membrane design concept is proposed. Using the filling-type membrane, the membrane solubility and the suppressing effect of swelling can be controlled independently. The filling-type membrane is composed of two materials: the porous substrate and the filling polymer which fills the pores of the substrate. The filling polymer exhibits permselectivity due to the solubility difference, and the porous substrate matrix suppresses the swelling of the filling polymer due to its mechanical strength. When membrane solubility, the suppression effect of membrane swelling, and solvent diffusivity in the membrane can be qualitatively predicted by model simulation, the filling-type membrane concept and the prediction method enable us to choose a suitable membrane material for a separation mixture. Pervaporation and vapor permeation flux through the membrane can be estimated by the calculated solubility, diffusivity, and suppression effect without any adjustable parameters. The calculated fluxes roughly agreed with experimental fluxes in a wide range between 0.002 and 48 kg/m(2) h, although a filling-grafted polymer was treated as a pure polymer. Effects of substrate strength and operating temperature were examined by the model.