Bibliography

ABSTRACT

This paper reports the results obtained by studying the transport properties of novel highly stable activated composite membranes (ACM) containing di-2-ethylhexyl phosphoric acid as a carrier. ACM samples containing different amount of DEHPA have been prepared by varying the DEHPA concentration in the casting solution. The selectivity of Ho and Pr transport through ACMs has been shown to depend on pH of the feed solution and DEHPA concentration in the membrane. ACM samples with a relatively low carrier content exhibit a higher selectivity for Ho, while an increase of DEHPA concentration in ACM results in the reversal of membrane selectivities. The transport properties of ACM do not change within a week of continuous operation.     

Click‐ligation of coumarin to polyether polyols for polyurethane foams

A simple strategy for the synthesis and functionalization of polyurethanes is described. Anionic ring‐opening polymerization was combined with ‘click’ chemistry to synthesize polyols with fluorescent properties. This route allows the incorporation of a wide range of functionalities in the polyols with an easy, clean and highly selective process compatible with several types of functional groups. The proposed strategy opens the way to the production, in a cost‐effective way, of ‘smart’ polyurethanes with non‐conventional properties like fire retardancy, antimite properties, antibacterial properties, etc. Alkynyl groups were introduced into the polyol chains by the controlled addition of glycidyl propargyl ether as co‐monomer during a conventional anionic ring‐opening copolymerization with propylene oxide. Subsequently 4‐azidomethyl‐7‐methoxycoumarin molecules were introduced onto the alkynyl‐polyether polyols by copper‐catalysed cycloaddition reactions to produce end‐functionalized polyols. The chemical structure of the novel polyols was characterized using infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography with triple detection and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectroscopy. These characterization techniques confirmed the presence of a considerable amount of functional groups in the structure of the polyols. Finally, various fluorescent rigid foams, based on the functionalized polyols, were synthesized. Copyright © 2012 Society of Chemical Industry     

Grafting of titanium dioxide microspheres with a temperature‐responsive polymer via surface‐initiated atom transfer radical polymerization without the use of silane coupling agents

Titania microspheres with narrow size distribution and diameters of about 1 µm were prepared and subsequently functionalized using surface‐initiated atom transfer radical polymerization (ATRP) of N‐isopropylacrylamide. The ATRP initiator was immobilized on the particle surface via acylation of surface hydroxyl groups with α‐bromoisobutyryl bromide. Subsequently, an established ATRP reaction system was used for the preparation of titania surface‐grafted poly(N‐isopropylacrylamide) (PNiPAAm). Characterization was performed with electron microscopies, X‐ray diffraction, infrared spectroscopy and dynamic light scattering. It was found that the particle size in aqueous dispersions changed reversibly with temperature as expected for a shell of PNiPAAm, a polymer with a lower critical solution temperature at 32 °C. This confirmed the successful preparation of functional, stimuli‐responsive TiO₂ microparticles via a straightforward controlled surface‐initiated polymerization method.     

Production of Polyunsaturated Fatty Acids by Mortierella alpina Using Submerse and Solid State Fermentation

A new isolate of Mortierella alpina, > 98 % identical with M. alpina ATCC 16266, was cultivated in a defined glucose‐based medium with three organic nitrogen sources (glycine, urea and Na‐L‐glutamate) at three different concentrations in shaking flasks at 20 °C. The results were compared to the cultivation in complex medium with yeast extract as nitrogen source. In the defined media, high yields of polyunsaturated fatty acids (PUFAs) and arachidonic acid (ARA), respectively, were obtained with Na‐L‐glutamate. However, the absolute highest yields of PUFA and ARA were measured with the yeast extract medium. An optimized yeast extract complex medium was used for a submerse bioreactor cultivation in a 45‐L scale. Furthermore, M. alpina was cultivated in a solid state fermenter, using an oat bran water mixture as substrate.     

Potential and Limitations of Natural Chabazite for Selective Catalytic Reduction of NOx with NH3

The potential of the natural chabazite for the selective catalytic reduction (SCR) of NOx with NH₃ is evaluated in the present work. Activity tests were performed under technically relevant reaction and temperature conditions for the fresh and hydrothermally aged catalysts. The natural chabazite before and after alkaline removal as well as after iron and copper addition were compared. The structural as well as surface and bulk properties were elucidated by a variety of complementary characterization techniques, i.e. XRD, XPS, EPR, BET, NH₃‐TPD, ex situ and in situ XAS. The results indicate that an important facet for using the natural chabazite for the standard and fast SCR reactions is the removal of alkaline metals, which at the same time also leads to a partial change of the structure and the size of the iron‐containing particles. The performance and especially the hydrothermal stability can be further improved by copper addition.     

Application of adaptive neuro-fuzzy interference system on biosorption of malachite green using fir (Abies nordmanniana) cones biomass

Removal of malachite green (MG) onto fir (Abies nordmanniana) cones biomass (FCB) as a lingo-cellulosic-based structure material was investigated in the present study. Characterization of FCB was performed using Fourier transform infra red and scanning electron microscobe analyses. Several parameters (biomass dose and particle size, dye concentration, temperature, and pH) were investigated to determine optimal working conditions. Subsequently, FCB yelded a q_e of 2.2?mg/g for 50?g/L FCB, in an MG solution of 110?mg/L, pH 3.3, at a temperature of 21?°C, on a 0.2-0.4?mm fraction powder after 146?h of contact. Adaptive neuro-fuzzy interference system modeling was applied to experimental data and results showed that predicted model fitted experimental data with R² = 0.994. In a nutshell, it can be concluded that FCB shows good potential for treating MG contaminated waters.     

Decolorization of textile dyes by Bjerkandera sp. BOL 13 using waste biomass as carbon source

BACKGROUND: Phanerochaete chrysosporium, Trametes versicolor and Bjerkandera sp BOL13 were compared for decolorization of azo dyes supplied individually or as a mixture. The dye decolorization was also evaluated during continuous treatment under non‐sterile conditions using a lignocellulosic growth substrate. RESULTS: Bjerkandera sp BOL13 showed the highest dye decolorization potential. This fungus was also found to support high decolorization of Remazol Red RR at an initial pH of 4‐6 and when using straw as co‐substrate. The fungus was evaluated for Remazol Red RR decolorization in a continuously fed packed‐bed bioreactor operated under non‐sterile conditions with 3 days of hydraulic retention time. When glucose was supplied as growth‐substrate, decolorization efficiencies of 65‐90% were maintained for 12 days in a bioreactor packed with wooden material. The decolorization efficiency was lower when glucose was not fed to the fungus or when a plastic material was used as packing. Higher manganese peroxidase and laccase activities were also recorded when the wood packing was used. Contamination caused a drop in decolorization efficiency after 17‐19 days operation. CONCLUSIONS: The potential of Bjerkandera sp BOL13 for decolorization of azo dyes under non‐sterile conditions using lignocellulosic growth substrates was demonstrated. Research is needed to reduce contamination under non‐sterile conditions. © 2012 Society of Chemical Industry