However, these phenomena are now also observed and verified by UV,FTIR,WAXD, and DSC studies for this PMMA/(DMF/CuCl 2♲H 2O) system. The refractive index difference between PMMA and DMF 0.0608 at 589 nm (sodium. The complex formation in the salt added film and the polymer crystallosolvate and adduct phenomena in the polyamides/acidic solvent system have been previously reported in the literature. Can anybody help me in finding the dn/dc value of PMMA standard in DMF. Crystallinity increases as the metal salt content increases in the complex membrane. From the morphology and crystallinity, we find that the improvement of oxygen permeability for the modified PMMA membrane is due to the swelling effect and complex formation of the PMMA/DMF/metal salt. For example, the oxygen permeability and O 2/N 2 separation factor of the complex membrane are 10.8 and 7.3 barrer, respectively. Gas permeabilities of PMMA membrane are significantly improved. The effect of membrane casting conditions on gas permeability, morphology, and crystallinity of the complex membranes as well as the existence and amount of PMMA/(DMF/metal salt) complex formation and the crystallosolvate and adduct phenomena of the casting solution were investigated. This study attempts to utilize complex formation and nonvolatile-solvent swelling effects to prepare (PMMA/CH 2Cl 2)/(DMF/CuCl 2♲H 2O) complex membranes for oxygen enrichment from air and to improve the extremely low gas permeabilities of poly(methyl methacrylate) (PMMA) membranes.
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