Selective removal of nitrate by using a novel macroporous acrylic anion exchange resin

An anion exchange resin NDP-5 has been prepared successfully and applied on the selective removal of nitrate from SO₄^2-/ NO₃^- binary co-existence system.The composition and morphology of NDP-5 were confirmed by FT-IR and SEM.The NDP-5 resin exhibits the completely different behavior on the adsorption capacity,adsorption kinetic and the effect of the completing anion in the absence or presence of sulfate,compared to D213.And,the resultants of kinetic are well fitted by the pseudo-first-order and pseudo-second-order models.These results are very important to develop novel resins with great features.     

Carbohydrate particles as protein carriers and scaffolds: physico-chemical characterization and collagen stability

We report a simple and effective supercritical fluid route to uniformly load ultrafine metal nanoparticles on the hydrophobic surfaces of graphene sheets. In the presence of supercritical carbon dioxide, PtRu alloy nanoparticles are decorated evenly on functionalized graphene sheets (FGSs) upon the reduction of organic platinum (II) and ruthenium (III) precursors, and its application as an electrocatalyst for methanol oxidation is studied. Transmission electron microscopy observation shows that highly dispersed PtRu metallic nanoparticles with an average size of about 3.11?nm are uniformly and densely distributed on the hydrophobic surface of FGSs. X-ray diffraction patterns demonstrate that the particles had a face-centered cubic crystal structure, and X-ray photoelectron spectroscopy analysis indicates the existence of zero-valence metals. Compared with the widely used Vulcan XC-72 carbon black, the PtRu/FGS composites exhibit superior catalytic activity and stability for methanol oxidation. The huge surface area of graphene and uniform distribution of nanosized metal particles are two critical factors for the significantly enhanced electrocatalytic efficiency. The findings suggest that the supercritical fluid method is highly efficient in preparing graphene-supported metallic catalysts, and FGSs serve as a favorable electrocatalytic carrier for direct methanol fuel cells.     

Imaging of the interstitial iron concentration in crystalline silicon by measuring the dissociation rate of iron–boron pairs

We present a dynamic approach for measuring the interstitial iron concentration in boron‐doped crystalline silicon using photoluminescence (PL) imaging. This camera‐based technique utilizes the characteristic dependence of the dissociation rate of iron–boron pairs on the interstitial iron concentration. We determine the dissociation rate by measuring the time‐dependent PL signal after complete association of iron–boron pairs in the sample. Since we are only interested in the time dependence of the PL signal, we are able to generate images of the interstitial iron concentration in absolute units without any calibration and without knowing the recombination properties of the interstitial iron or iron–boron pairs. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Laccase Production by the Aquatic Ascomycete Phoma sp. UHH 5-1-03 and the White Rot Basidiomycete Pleurotus ostreatus DSM 1833 During Submerged Cultivation on Banana Peels and Enzyme Applicability for the Removal of Endocrine-Disrupting Chemicals

This work aimed to study the production of laccase from Pleurotus ostreatus DSM 1833 and Phoma sp. UHH 5-1-03 using banana peels as alternative carbon source, the subsequent partial purification and characterization of the enzyme, as well the applicability to degrade endocrine disruptors. The laccase stability with pH and temperature, the optimum pH, the K _m and V _max parameters, and the molar mass were determined. Tests were conducted for assessing the ability of degradation of the endocrine disruptors t-nonylphenol, bisphenol A, and 17??-ethinylestradiol. Laccase production of 752 and 1,117?U?L^?1 was obtained for Phoma sp. and P. ostreatus, respectively. Phoma sp. laccase showed higher stability with temperature and pH. The laccase from both species showed higher affinity by syringaldazine. The culture broth with banana peels induced the production of two isoforms of P. ostreatus (58.7 and 21?kDa) and one of Phoma sp. laccase (72?kDa). In the first day of incubation, the concentrations of bisphenol A and 17??-ethinylestradiol were reduced to values close to zero and after 3?days the concentration of t-nonylphenol was reduced in 90% by the P. ostreatus laccase, but there was no reduction in its concentration by the Phoma sp. laccase.     

Impact of crystallinity of poly(lactide) on helium and oxygen barrier properties

The helium and oxygen gas barrier properties of poly(lactide) were investigated as a function of stereochemistry and crystallinity degree. Poly(l-lactide) and poly(d,l-lactide) films were obtained by extrusion and thermally cold crystallized in either α′- or α-crystalline form with increasing crystallinity degree. Annealing of the films at low temperatures yielded to α′-crystals as well as the creation of a rigid amorphous fraction in the amorphous phase. Unexpectedly, the quantity of the rigid amorphous fraction was highest in poly(l-lactide) crystallized under α′-form. Unexpectedly, the gas permeability increased with increasing quantity of α′-crystals in poly(l-lactide) and remained constant with increasing quantity of α′-crystals in poly(d,l-lactide). A gain in gas barrier properties was obtained upon crystallization at higher temperatures yielding α-crystals. The analysis of the oxygen transport parameters, in particular the diffusion and the solubility coefficient showed that the diffusion was accelerated upon crystallization, while the solubility coefficient decreased in an expected manner which led to conclude that it remained constant in the amorphous phase. The acceleration of the diffusion seems to be correlated to the occurrence of the rigid amorphous fraction, which holds larger free volume. To conclude, for optimization of poly(lactide) gas barrier properties by focussing on the decrease of the diffusion coefficient it can be suggested to work with poly(d,l-lactide) and to aim a crystallization in α-form avoiding the formation of a rigid amorphous fraction.