Chemistry of macromolecular architectures is one of the fastest growing branches of polymer chemistry. The present review is described about macromolecular architectures for separation membranes relating their structure and permselectivity, and is focused on dendrimers for separation membrane. The separation membranes using dendrimers contain synthesis and characterization of polydendrons or dendronized polymers and gas permselectivity of their membranes, and preparation and permselective behavior of polymer membranes crosslinked by dendrimers or hyperbranched polymers, and of dendrimers-attached composite polymer membranes.

View full abstract

Studies on diffusion and permeation of smart membranes such as syndiotactic polystyrene (sPS) α form and mesophase were carried out. The presence of regularly arranged channel like and capillary type molecular cavity with a diameter of approximately 4 Å was confirmed in crystalline unit of PMP and sPS a form, respectively, by the examination of diffusion and permeation of 8 gases with different molecular sizes. Next, preparation of another smart membrane was carried out for an establishment of high performance separation membrane. The smart membrane contains subnano scaled molecular cavity which is constructed by polymer architecture, which is similar to the structure of small molecules separated and is aligned regularly in crystalline polymers. First the δ form complex of sPS is obtained from a solution containing good solvent, and then good solvent as guest molecule was extracted stepwisely from the δ form complex using first extraction solvent of acetone and second extraction solvent of methanol. We could prepare molecular cavities with different sizes and shapes. Sorption of small molecules into the molecular cavity demonstrated preferential sorption in a manner of Langmuir type depending on the size and shape of both small molecules and molecular cavities.

View full abstract