RESUMO
Copolymer E(17)B(12) (E denotes OCH(2)CH(2), B denotes OCH(2)CH(C(2)H(5)), and the subscripts denote number-average chain lengths) was prepared by sequential oxyanionic polymerization and characterized by GPC (for distribution width) and NMR spectroscopy (for absolute composition and chain length). Dynamic and static light scattering and rheometry were used to characterize micelles in dilute solution and demonstrate the formation of compact micelles at low temperatures and of elongated micelles at higher temperatures, the latter being accompanied by turbidity of the solution. Rheological methods applied across a range of concentrations and temperatures served to demonstrate the formation of worm-like micelles. Gels based on entangled worm-like micelles (some of them turbid) and on packed compact micelles were identified and their properties were explored.
RESUMO
Novel types of microporous material are required for chemoselective adsorptions, separations and heterogeneous catalysis. This concept article describes recent research directed towards the synthesis of polymeric materials that possess microporosity that is intrinsic to their molecular structures. These polymers (PIMs) can exhibit analogous behaviour to that of conventional microporous materials, but, in addition, may be processed into convenient forms for use as membranes. The excellent performance of these membranes for gas separation and pervaporation illustrates the unique character of PIMs and suggests immediate technological applications.
RESUMO
Microporous materials can be derived directly from soluble polymers whose randomly contorted shapes prevent an efficient packing of the macromolecules in the solid state.
RESUMO
Network polymers exhibiting large surfaces areas (900-1000 m2g-1) are prepared by the highly efficient dibenzodioxane forming reaction between meso-tetrakis(pentafluorophenyl)porphyrin and a rigid bis(catechol) monomer.
