Membranes nanostructured polymer

Along similar lines, other researchers have been looking into nanocomposite membranes.16 Researchers at the University of Colorado at Boulder have been developing lyotropic liquid crystals (LLCs) to form what they call nanostructured polymer membranes.16 The LLCs can from liquid crystalline phases with regular geometries... 

Along similar lines, other researchers have been looking into nanocomposite membranes. Researchers at the University of Colorado at Boulder have been developing lyotropic liquid crystals (LLCs) to form what they call nanostructured polymer membranes. The LLCs can form liquid crystalline phases with regular geometries which act as conduits for water transport while rejection ions based on size exclusion. In bench-scale tests, nanostructuered polymer membranes exhibited a rejections of 95% and 99.3% of sodium chloride and calcium chloride, respectively. These membranes also exhibited greater resistance to chlorine degradation than... 

Ivanov Y, Marinov I, Gahrovska K, Dimcheva N, Godjevargova T (2010) Amperometric biosensor based on a site-specific immobilizatimi of acetylcholinesterase via affinity bmids on a nanostructured polymer membrane with integrated multiwall carbon nanotubes. J Mol Catal B-Enzym 63(3-4) 141-148. doi 10.1016/j.molcatb.2010.01.005... 

Within the scope of thermoelectric nanostructures, Sima et al. [161] prepared nanorod (fibril) and microtube (tubule) arrays of PbSei. , Tej by potentiostatic electrodeposition from nitric acid solutions of Pb(N03)2, H2Se03, and Te02, using a 30 fim thick polycarbonate track-etch membrane, with pores 100-2,000 nm in diameter, as template (Cu supported). After electrodeposition the polymer membrane was dissolved in CH2CI2. Solid rods were obtained in membranes with small pores, and hollow tubes in those with large pores. The formation of microtubes rather than nanorods in the larger pores was attributed to the higher deposition current. 

Some applications nonrelated to the properties of the nanoporous materials but to their porous structures are their use as filtration membranes, battery separators (hindering the diffusion of ions in the narrow channels), and catalyst supports (due to their high surface area) as well as gas capture and storage or light harvesting [72]. However, the common factor of all of these applications is the requirement of an open nanoporous structure not only inside the sample but also connected to the exterior of the sample. However, the CO2 foaming process from nanostructured polymers still has not allowed obtaining nanoporous samples with all of these features. Pinto et al. [102] proposed that 25/75 PMMA/MAM nanoporous foams present appropriate inner porous structures for these kinds of applications (bicontinuous nanoporous structures with tunable pore size), but further studies are required to connect effectively this inner porous structure with the exterior of the sample. 

Jiang J, Kucemak A. Investigations of fuel cell reactions at the composite microelectrode solid polymer electrolyte interface. I. Hydrogen oxidation at the nanostructured PtNafion membrane interface. J Electroanal Chem 2004 567 123-37. 

Wang, L. S., Chow, P. Y, Phan, T. T., Lim, I. J., Yang, Y. Y. (2006). Fabrication and characterization of nanostructured and thermosensitive polymer membranes for wound healing and cell grafting. Advanced Functional Materials, 16, 1171-1178. 

The mass transport mechaiusm of gases permeating in a nanocomposite is similar to that in a semicrystalline polymer. The nanocomposite is considered to consist of a permeable phase where non-permeable nanoplatelets are dispersed. There are mainly three factors that influence the permeabiUty of nanocomposites the volume fraction of the nanoparticles, their relative orientation to the diffusion direction and their aspect ratio. The gas transport behavior of two different nanoclay-reinforced EVA membranes has been analyzed using oxygen and nitrogen gases and the results were compared with neat EVA. EVA nanostructured polymer blends exhibit excellent barrier properties. 

Gas permeation through a polymer membrane is not only a function of the chemical structure of the polymer chains, but is also determined by a morphology inside the film with typical domain dimensions of several nanometers. Membranes from commercial polyether- -polyamide (PEBA) polymers with varying chemical composition, cast from both n-butanol and cyclohexanol are studied by SAXS, in dry form and water-swollen, and as a function of strain. The nanostructure from soft and hard domains is determined [681. 

M. Bryjak, I. Gancarz, K. Smolinska, Plasma nanostructuring of porous polymer membranes, Aiiv Colloid Interfac, 161 (2010) 2-9. 

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