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Simion D.,INCDTP Division Leather and Footwear Research Institute | Niculescu O.,INCDTP Division Leather and Footwear Research Institute | Gaidau C.,INCDTP Division Leather and Footwear Research Institute | Simion M.,INCD ECOIND | And 2 more authors.
Leather and Footwear Journal | Year: 2011

he influence of surfactants upon the wettability of some hydrophobic microporous membranes of polysulphone was studied by determining the contact angle and the ultrafiltration rates. The water-membrane contact angle increases with roughness and changes in presence of the surfactant in aqueous solution to an extent which depends on its nature and concentration. The variations of contact angle of surfactant in aqueous solution are in good agreement with the variation of the rate of ultrafiltration solutions through membranes and with the adsorption of surfactants on polysulphone surface. The method of measuring the contact angle is simple and rapid; it may be employed in characterization of polysulphone membrane, hydrophobicity in spite of the scattering of values obtained of microporous surfaces. Source


Simion D.,INCDTP Division Leather and Footwear Research Institute | Popescu G.,Research Center for Macromolecular Materials and Membranes | Gaidau C.,INCDTP Division Leather and Footwear Research Institute | Koleva M.,University of Chemical Technology and Metallurgy of Sofia | Albu B.-G.,Research Center for Macromolecular Materials and Membranes
Proceedings of the 4th International Conference on Advanced Materials and Systems, ICAMS 2012 | Year: 2012

Specific separation at molecular level implies the development of new materials and nanostructures. The paper deals with the preparation of new materials and nanostructures for nanotechnology application. Three directions are studied namely, preparation of complexant nanoparticles by grafting of carriers onto the surface of nanoparticles, micellar enhanced ultrafiltration and obtaining of ceramic nanostructures. Membrane technology is a relatively new separation process, which fulfils these criteria. It can be applied in process integrated systems and in this way waste problems are drastically reduced while valuable products are recovered. A specific separation process at molecular levels implies the development of new materials and nanostructure correlated with the physical and chemical properties of the compounds that must be removed or separated. The research directions studied in the paper showed that modifications at the level of nanostructures leads to new materials that can be applied in technologies related to separation using ultrafiltration (UF) or micellar-enhanced ultrafiltration (MEUF) of: orange III, methyl red, fenoftalein, phenol, Cu2+. In the literature this process is known as nanotechnology. In conclusion we can point out that the new materials described in the paper have specific properties for separation at molecular level with great impact in the development of the nanotechnology. Source


Simion D.,INCDTP Division Leather and Footwear Research Institute | Popescu G.,Research Center for Macromolecular Materials and Membranes | Maruta C.,Research Center for Macromolecular Materials and Membranes | Gaidau C.,INCDTP Division Leather and Footwear Research Institute | Ozgunay H.,Ege University
Proceedings of the 4th International Conference on Advanced Materials and Systems, ICAMS 2012 | Year: 2012

The separation of uranyl ions from dilute solutions can be realized by a facilitated transport using a carrier, dissolved in an membrane. This process was realized by emulsion liquid membranes technique and is a solution to a problem of environmental pollution. By this method, aqueous solutions containing uranyl ions in the range 2-10 mg/L were extracted and concentration reduced to under 0,4 mg/L, so that these solutions can be delivered to surface waters. The inverted emulsions used in extractions were obtained by stirring equal volumes of organic phase and aqueous stripping solution containing NaHCO3 and Span 80. Liquid membranes containing mobile complexing agents have been widely studied in the form of inverted emulsions known as emulsion liquid membranes (ELM). The present work is original because presents the possibility of using ELM method to separate the uranyl ions UO22+ from dilute solutions and waste waters. By dispersing the inverted emulsion Water/Oil in the phase source, a liquid membrane is realized between the two phases, source and receiving solution. In conclusion it was demonstrated the possibility of applying the ELM technique using ammonium quaternary salts as carrier to remove the uranyl ions from waste waters with high extractions yields (85-90%). Source


Georgescu M.,Research Center for Macromolecular Materials and Membranes | Radu M.,Research Center for Macromolecular Materials and Membranes | Albu B.,Research Center for Macromolecular Materials and Membranes | Pasare L.,Research Center for Macromolecular Materials and Membranes | And 2 more authors.
Proceedings of the 3rd International Conference on Advanced Materials and Systems, ICAMS 2010 | Year: 2010

This paper is focused on line of domains diversification of proton exchange membranes, by the synthesis of three new materials: poly(monobrom-2.6- dimethyil-1.4-phenyleoxid)-PPOBr, sulfonating polyetherethereketone (SPEEK) and sulfonating polysulfone (PSS). The structures and characteristics of polymers confer membranary materials special properties imposed for electromembranary applications: lower electrical resistance, high counter-ions permeability, high permselectivity, high mechanical resistance, dimensional stability, chemical stability in the whole range of pH, high thermal stability. The membranes obtained from PPOBr, SPEEK and PSS were characterized by specific methods, to give evidence of their performances, comparatively with commercial membranes (Nafion - cationic, and ExcellionTM - anionic), which are very expensive. Source


Rata D.,Research Center for Macromolecular Materials and Membranes | Pasare L.V.,Research Center for Macromolecular Materials and Membranes | Albu B.G.,Research Center for Macromolecular Materials and Membranes | Radu M.,Research Center for Macromolecular Materials and Membranes
Materiale Plastice | Year: 2010

This paper presents the preparation by phase inversion of polysulfone and cellulose acetate ultrafiltration membranes (UF1-UF36)with various amounts of PEG additives (1000, 2000, 4000 Da), designed for the whey protein separation. To establish optimal operating conditions for membrane separation and the membrane with the best characteristics for the ultrafiltration of whey, we determined the now vanation of the two types of whey (pH-6.21, pH=4.35) with different parameters: whey temperature, operating pressure, protein retention and clogging phenomenon. All the results indicated that at the same protein separation efficiency (MWCO), the polysulfone membranes present higher flows than cellulose acetate membranes and their use in the acid whey ultrafiltration process lead to a whey protein concentrate with a protein content about 5 times higher than the initial whey content (6.4 kg/m3). The best protein retention 98.73% was obtained for UF18 membrane (20% PS, 2 % PEG 4000), with optimal flow rate (23.9-10-6 m2/m2s) for acid whey, operating at 50°C and 106Pa. Source

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