The natural balance in the Earth's atmosphere is significantly influenced by the human emission of the combustion products, mainly carbon dioxide. Therefore, strong efforts are directed in the direction of the reduction of that emission. The solution might be searched in the direction of the construction of the membrane that would be highly transparent to the carbon dioxide, but not transparent to the other gases commonly present in the waste gases (oxygen, nitrogen, hydrogen, methane). One of the feasible designs for this purpose is dense, non-porous membranes, with zeolite particles dispersed in the polymer matrix. Zeolite particles should increase the solubility of the carbon dioxide, and thus enhance its permeability. In this paper, the possibility of application of polyether-b-amide (with 60% of PEG) as a polymer matrix was tested. For the inorganic component, four different zeolite types with three different pore geometries were tested. The influence of the additive which was added in order to provide good contact between the highly polar and charged zeolite inorganic particle, and hydrophobic polymer chains was also tested.
Izvod Cilj ovog rada je bio karakterizacija glatkih pletenina u pogledu sposobnosti upravljanja vlagom (propuštanja vodene pare i znoja) uzimajući u obzir faktore na mikroskopskom (vlakna), mezoskopskom (pređa) i makroskopskom (pletenina) nivou. U tu svrhu su, polazeći od pređa izrađenih od prirodnih i regenerisanih celuloznih vlakana, u kontrolisanim uslovima proizvedene glatke DL pletenine koje su podvrgnute ispitivanju propustljivosti vodene pare i tečnosti. Dobijeni rezultati ukazali su na kompleksan uticaj hijerarhijske strukture tekstilnog materijala na njegovu sposobnost upravljanja tečnostima. Pokazalo se da pored distribucije pora u pleteninama, koja je u okviru eksperimentalnog materijala bila uslovljena deformacionim svojstvima vlakana i primenjenim tehnikama predenja, propustljivost vodene pare može biti modifikovana geometrijom površine pređe, dok morfologija vlakana može da modifikuje propustljivost tečnosti.
In this study, electrospinning combined with sol-gel technique is applied in order to produce magnetic nickel ferrite (Ni-ferrite) nanofibers. The prepared Ni-ferrite gel was mixed with poly(vinylpyrrolidone) (PVP) solution which was used as a spinning aid to enable spinnability of the mixture. Structural and morphological characteristics of the as-spun ferrite gel/PVP composite web structure and calcinated Ni-ferrite nanofibers were analyzed using scanning electron microscopy (SEM). Phase composition analysis was carried out by Fourier-transform infrared (FT-IR) spectroscopy, X-Ray diffraction analysis (XRD) and 57Fe Mössbauer spectroscopy (MS). The obtained results suggest that the pure nanocrystalline NiFe2O4 dense mat to the almost coral-like structure of fibers with diameters ranging from hundreds of nanometers to few micrometers was obtained. The results of MS analysis revealed the existence of a crystallite size distribution within the material as well as the existence of a superparamagnetic fraction with very small crystallite sizes (<13nm). Magnetic behavior of the obtained material at elevated temperatures was also scrutinized using thermomagnetic measurements (TM) up to 800 °C.
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