Polymers Receiving Special Interest

The perfluorinated polymers ate materials of special interest due to their exceptionally good chemical and thermal stabdity compared to other polymers. The challenge has however for many years been to prepare these materials with suitable gas separation properties. They used to be either very crystalline or too porous, hence selectivities were low. They may however be prepared as high flux— low selectivity membranes, which is acceptable for certain applications. Materials prepared from tetrafluoroethylene (TEE) 

FIGURE 4.9 Example of structure of a cardopolymer based on pol3nnude. 

Kharitonov et al. [59] have shown that direct fluorination of the polyimide Matrimid is possible, hence the resulting membrane should have a nice potential for use in harsh environment. Perfluorinated materials were also studied by Hagg [60] for chlorine gas purification, and were shown to be exceptionally stable in these harsh environments. The selectivity was however too low. In a later publication on chlorine purification [31] it was suggested to use perfluorinated monomers as surface-modifying compounds for pore tailoring of glass membranes for chlorine gas separation. 

FIGURE 4.10 Relationship between mixed gas n-butane permeability and n-butane/methane selectivity for a series of glassy poly acetylenes and rubbery PDMS. Feed pressure 10 bar permeate pressure 1 bar temperature 25°C. (From Pinnau I., He Z., Morisato A., J. Membr. Sci., 241, 363, 2004. With permission.) 

The biomimetic membranes represent a special group of carrier membranes. They are artificial membranes based on biomembrane mimicking, i.e., imitation of the essential features bio membranes use for separation. Nitrocellulose filters impregnated with fatty acids, their esters, and other lipid-like substances may be used— in other words, an imitation of many nonspecific barrier properties of biomembranes. The transport of gas through these membranes will essentially be according to facilitated transport (see Section 4.2). Biomimetic membranes for CO2 capture will transport the gas as HCO3. Development of these materials may be expected for selected applications. 

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Mechanical characterization under static loading of polymer-based nanocomposites has been widely studied in order to evaluate the influence of nanofiller content, dispersion, geometry, orientation, interfadal adhesion quality, and others on their mechanical performance. Layered silicates and CNTs are the most studied reinforcing agents in polymers due to their large aspect ratio and mechanical properties, but in the past decade particulate nanofillers such as sUica or functionalized graphene (FG) have received special interest. 

Royce W. Murray is Kenan Professor of Chemistry at the University of North Carolina at Chapel Hill. He received his B.S. from Birmingham Southern College in 1957 and his Ph.D. from Northwestern University in 1960. His research areas are analytical chemistry and materials science with specialized interests in electrochemical techniques and reactions, chemically derivatized surfaces in electrochemistry and analytical chemistry, electrocatalysis, polymer films and membranes, solid state electrochemistry and transport phenomena, and molecular electronics. He is a member of the National Academy of Sciences. 

Of special interest is a new type reaction discovered with N20 direct oxidation of alkenes to carbonyl compounds, called carboxidation. Beside various individual alkenes, carboxidation can be applied effectively to unsaturated polymers, opening up a way for the preparation of new materials. Reactions of this type should receive special attention from the catalytic community, since currently they are conducted in a thermally. This oxidation area is waiting for the beneficial arrival of catalysis to provide better control of the activity and selectivity. 

Gabriel Rokicki is a chemistry professor at the Faculty of Chemistry, Warsaw University of Technology, Poland, where he received all his academic education (MSc in 1971, PhD in 1989, and tenure professor in 2002). His current scientific activities include synthesis, stmcture, and properties of polymer materials, such as aliphatic polycarbonates, polyurethanes, epoxy resins, and biodegradable polymers. He has devoted a special interest to the use of functional polymers in obtaining specialty ceramic materials as well as to polymer recycling. Earlier major interests included the utilization of carbon dioxide and cyclic carbonates in the synthesis of condensation polymers. Another topic of interest was polymeric ion-sensors based on modified calixarenes. He is the author and coauthor of 160 scientific papers and holds more than 50 patents in the above-mentioned areas. At the Faculty of Chemistry of Warsaw University of Technology, he conducts lectures on polymer chemistry and technology. 

Polymer colloids have received an increasing interest in various applications and also biomedical areas in which they are mainly used as solid-phase supports of biomolecules. This is due to the versatility of the many heterophase elaboration processes (emulsion, dispersion, precipitation, physical processes) for making well-defined microspheres of appropriate particle sizes and surface reactive groups. In this direction, special attention has been dedicated to the preparation of smart colloids. The principal interest carried to colloidal particles based on alkyl(metha)acrylamide derivative is mainly related to their thermally sensitive colloidal properties. 

Incoronata Tritto studied stereospecific olefin polymerization in the group of Prof. Adolfo Zambelli at the Institute for Macromolecular Chemistry of the CNR and received her degree in polymer science at the Specialization School Giulio Natta at Politecnico di Milan (Italy) in 1981. In 1982, she joined as permanent researcher the Institute for Macromolecular Chemistry of the CNR In 1988, she spent 1 year in the group of Prof. Robert H. Grubbs at Caltech (USA), where she studied the relationship between metathesis and addition olefin polymerization. She is currently a senior research chemist at ISMAC-CNR. Her research interests focus on (1) synthesis and microstmctural characterization of stereospecific olefin and cyclic olefin homo- and copolymers by transition metal catalysts (2) activation and deactivation reactions ofthe homogeneous catalytic systems by in situ multinuclearNMR analysis and (3) synthesis of block copolymers and nanostructured hybrid polymers, in situ polymerization on clay and carbon nanotubes. 

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