Rare Earth Metal Oxides Research Articles

Production of individual rare earth metal oxides from luminophore wastes

Production of individual rare earth metal oxides from luminophore wastes

Augmented gravimetric and volumetric capacitive performance of rare earth metal oxide (Eu2O3) incorporated polypyrrole for supercapacitor applications

We report a facile in situ synthesis approach to incorporate rare earth metal oxide (Eu2O3) into the polypyrrole matrix and evaluate its electrochemical performance as supercapacitor electrode material. Polypyrrole, having good conductivity, higher chemical and thermal stability proves to be a very interesting electrode material. Eu2O3 further augments the capacitance of the material owing to its variable oxidation states. Also, owed to the higher stability, it provides additional support to the polymer backbone imparting extra thermal and cyclic stability to the hybrid composite so formed. The PPy/Eu2O3-32 composite exhibits a volumetric capacitance of 535Fcm−3 at the current density of 1Ag−1. This material also exhibits an improved energy density of 13.5WhL−1 and a maximum power density of 4597.25WL−1. Further, a good rate capability (18% loss of specific capacitance from 1 to 10Ag−1) and high coulombic efficiency (99.8% at 10Ag−1) proves integration of Eu2O3 with PPy to be an effective way to eliminate the drawbacks of PPy in pristine form.

Enhancing the Photovoltaic Performance of Dye-Sensitized Solar Cells with Rare-Earth Metal Oxide Nanoparticles

Dye-sensitized solar cells consist of a photoanode of a mesoporous film of titania sensitized with dye sandwiched with a counter electrode, which is usually a platinum-coated transparent conducting oxide, and a redox couple injected between the photoanode and counter electrode. Doping titania with rare-earth metals has been an interesting approach to improve the conversion efficiency of dye sensitized solar cells. Rare-earth metals have been doped into titania paste to show an improvement in the photovoltaic performance of dye-sensitized solar cells, however, most of the reported cells are not efficient enough to conclude whether the enhancement is due to doping or it is because of the cell quality. We incorporated nanoparticles (<100 nm) of oxides of rare-earth metal (neodymium and erbium) in titania paste and built dye-sensitized solar cells using amphiphilic C101 dye and nitrile based iodide/triiodide redox couple, Z960 electrolyte. The doping level for optimized cells was 2.0 % for neodymium oxide and 1.0 % for erbium oxide. Our cells exhibit efficiencies more than 10 % and the best erbium oxide doped cell displayed an efficiency above 11 %. We measured the photocurrent, impedance, IPCE, dye loading, and film conductivity to investigate the enhancement of the photovoltaic performace by rare-earth metal oxides. Electrochemical impedance spectroscopy (EIS) measurements showed that doping with rare-earth metals decreased the total impedance of the cell and IPCE measurements revealed enhanced photon absorption by the dye in rare-earth metal doped cells. In the same fashion, the rare-earth metal -doped anodes showed larger dye loading compared to undoped anodes, which was maximum for 1.0 % doping of erbium oxide and 2.0 % doping of neodymium oxide. Rare earth metal oxides not only enhance dye adsorption but also facilitate electron tranport through the mesoporous layer, thereby increasing the collection efficiency of the photoexcited electrons.

Recovery of rare earth metals as critical raw materials from phosphorus slag of long-term storage

The present research is directed towards processing of slag originating during the yellow phosphorus production. The slag was investigated using physical and chemical treatment methods. The following group of rare earth elements were identified in phosphorus slag such as: Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Ho, Tm, Yb, Lu. Thermodynamic calculation for reactions probability of phosphorous slag components with nitric acid was made. Nitric-acid leaching of slag generated during phosphorus production was investigated for extraction of rare earth metals (REMs). Silicon containing cake obtained after leaching was suitable for precipitated silicon dioxide production. Behaviour of associated components such as calcium, aluminium and iron was studied during the leaching process. The following optimum parameters were selected for leaching studies: nitric acid concentration was 7.5mol/dm3; solid-to-liquid ratio was 1:2.6–3; temperature was 50–80°С; process duration was 1h; pulp stirring rate was 500rpm and the recovery of rare-earth metals, calcium, aluminum and iron into the solution were seen to be 85%, 98%, 80.7%, and 11.8%, respectively. Cake produced as a result of leaching contained ∼80–85% of amorphous SiO2. The solution obtained after phosphorus slag leaching was processed through solvent extraction methods to concentrate and separate it from basic macroimpurities. After precipitation of REMs oxalates from strip liquor and calcination of the precipitate a concentrate was obtained, which contained ∼17% of ∑REMs oxides.

In-Situ Integration of Waste Coconut Shell Derived Activated Carbon/Polypyrrole/Rare Earth Metal Oxide (Eu2O3): A Novel Step Towards Ultrahigh Volumetric Capacitance

A facile approach to synthesize a hybrid polymeric composite with ultra-high volumetric capacitance by incorporating waste coconut shell derived activated carbon (AC) and rare-earth metal oxide (Eu2O3) into the polypyrrole (PPY) matrix has been reported in this work. The composite is synthesized via in situ oxidative polymerization. The PPY/AC/Eu2O3 composite stores energy both Faradaically and electrostatically. Further, the electrochemical performance gets augmented with the incorporation of rare earth metal oxide Eu2O3 owing to the availability of multiple valence states and development of stronger interaction with PPY which a good electron donor in turn leading to easy protonation of PPY. The as-prepared composites exhibit a highest gravimetric capacitance 670Fg−1 and an outstanding volumetric capacitance 1090Fcm−3 at the current density of 1Ag−1. Also, the composite with the maximum volumetric capacitance exhibits a high-power density of 4108WL−1 with the maximum energy density of 37.85Wh L−1 at the current density of 1Ag−1.

Facile fabrication of graphene-based aerogel with rare earth metal oxide for water purification

We report a one-step facile fabrication of macroscopic multifunctional graphene-based aerogel with three-dimensional interconnected networks under the synergistic effects of the reduction of graphene oxide sheets by L-ascorbic acid and in situ simultaneous deposition of nanoparticles on graphene sheets. The functional components, Nd2O3 nanoparticles, can be easily incorporated with graphene sheets to assemble bulk macroscopic graphene materials under mild conditions. The reduced graphene oxide/neodymium oxide (rGO/Nd2O3) aerogel showed remarkable adsorption capacity towards different types of dyes, especially for anionic dyes, with the adsorption capacity for indigo disulphonate (ID) being more than 220mgg−1 within one hour while the adsorption capacity at equilibrium is as high as 397mgg−1. The method proposed is proven to be universal to induce macroscopic assembly of reduced graphene sheets with rare earth metal oxides and thus facilitates to accessing various graphene-based multifunctional nanocomposites in the form of macroscopic aerogels.

Self-Propagating High-Temperature Synthesis of Chromium Substituted Lanthanide – Barium – Copper Oxides, LnBa2Cu3-xCrxO7-y (Ln = Y; La; Nd; Sm and Yb)

&lt;p&gt;A series of MBa&lt;sub&gt;2&lt;/sub&gt;Cu&lt;sub&gt;3-x&lt;/sub&gt;CrxO&lt;sub&gt;7-y&lt;/sub&gt; (M = Y; La; Nd; Sm and Yb; &lt;em&gt;x &lt;/em&gt;= 0, 0.05, 0.15, 0.25) materials were synthesized in air by self-propagating high-temperature synthesis (SHS) involving reaction of stoichiometric mixtures of rare-earth metal (III) oxide, barium peroxide, copper metal, chromium (III) oxide and sodium perchlorate. All the SHS processes were followed by sintering in oxygen at 950 °C for 2h. The products were characterized by SEM, X-ray powder diffraction, UV, superconductive transition temperatures (T&lt;sub&gt;c&lt;/sub&gt;) and magnetic susceptibility (χ) measurements. X-ray diffraction data showed that single phase orthorhombic (or tetragonal for M = Nd) materials were produced. All series of materials showed a systematic increase in lattice parameters and unit cell volume with chromium content (M = Y: &lt;em&gt;x &lt;/em&gt;= 0, &lt;em&gt;V &lt;/em&gt;= 174.25 Å3; &lt;em&gt;x &lt;/em&gt;= 0.25, &lt;em&gt;V &lt;/em&gt;= 175.10 Å3). Thermal stability of all the SHS prepared materials increased with &lt;em&gt;x&lt;/em&gt;. Oxygen content of all the samples increased with &lt;em&gt;x&lt;/em&gt;, but did not exceed 7.0. Superconductivity transition temperature decreased with chromium substitution in all systems (98-77 K). Magnetic susceptibility decreased with chromium substitution.&lt;/p&gt;

Bifunctional Strategy Coupling Y2O3-Catalyzed Alkanal Decomposition with Methanol-to-Olefins Catalysis for Enhanced Lifetime

Bifunctional strategies exploiting the selective and catalytic decomposition of formaldehyde by Y2O3 improve the lifetime of CHA zeotypes and zeolites for methanol-to-olefins catalysis 4-fold, as quantified by total turnovers, without disrupting the inherently high selectivity to light olefins. The improvement in catalyst lifetime increases with increasing proximity between H+ sites of the zeotype/zeolite and the surface of the rare earth metal oxide. This proximity effect demonstrates crucial transport of formaldehyde between and within zeotypic/zeolitic domains on catalyst lifetime. These results provide mechanistic insights revealing formaldehyde as an accelerant for the initiation and termination of chain carriers and exemplify a strategy for designing improved methanol-to-olefins catalysts by optimizing (bi)functionality and reaction-transport dynamical phenomena.

Multifunctional application of cytosine for the synthesis of hybrid homogenized nano-sized rare earth oxide (Re2O3) and rare earth oxycarbonate (Re2O2CO3) (Re = Nd, Sm) advance material via microwave irradiation

For the first time in the world* a novel microwave irradiated chemical process has been developed for the synthesis of hybrid homogenized nanosized rare earth oxide (Re2O3) and rare earth oxycarbonate (Re2O2CO3) (Re = Nd, Sm) advance material using cytosine molecule. Aqueous nitrate (iii) salt of rare earth metal is allowed to react with cytosine in the presence of microwave irradiation of power source 230 V for 15 minutes at the temperature of 45°C to get the desired product. Cytosine acts as a multifunctional agent by being a source of alkaline amine, carbon containing moieties, a highly effective capping agent and therefore enabling synthesis of hybrid homogenized nanosized advance material of rare earth metal oxide and oxycarbonates. The synthesized materials were characterized by various complementary techniques namely XRD, FTIR, U.V visible, FESEM, EDXA. FESEM study revealed that the sizes of nano particles are up to 21 nm. The applications of synthesized material lies in the area such as CO2 sensor, ceramic, cosmetic, advance glass, optical fiber, luminescent, superconducting,catalyst, nanowire, nanofibre, advance magnets, phosphate removal agent from water and also in biomedical.

Обоснование механизма доминирующего государственного участия в освоении ресурсов высоколиквидных полезных ископаемых Арктики

For a scientific discussion the authors present proposals on the formation in Russia of a new form of effective mineral resource base development of the strategic solid mineral resources in the Arctic zone of Siberia and the Far East. The mechanism is based on the prevailing govenmental participation in projects of development and exploitation of highly liquid metals (rare earth elements, Tomtor ore cluster in Yakutia) and minerals (diamond abrasive materials, Rock Popigai meteorite crater deposit in Krasnoyarsk region) in the Siberian Arctic, carried out under conditions of high risk. Shown, that due to the unique parameters of both rare earth and diamond ores flow of hi-tech products and semi-products is formed. With the extension of the technological and value chain - delivery to the domestic and the global markets of highly liquid products (oxides of rare earth metals and high-purity metals, technical super abrasive diamond powders and products for the treatment of materials). Thus, a cluster for the production of final products based on rare-earth metals and super abrasive rough diamonds with high added value can be created. Milestones and additional exploration operations, preparations for the operation and development of deposits are carried out by the State Corporation for Mineral Resources with the joint participation, investment, technological cooperation of private companies and research organizations. The Corporation could be considered as a platform for international cooperation and foreign investment in technological chains of a presented mega-project of development of two closely located deposits. Introduced organizational and economic mechanism allows to: a) carry out public administration of complex resource projects in the Arctic and to develop them to an economically efficient level with a gradual sale of business projects to the private sector; b) to initiate and stimulate long-term scientific and technological development in conditions of high risk; c) to form a system of preferences for the development of Russian high-tech exports; d) ensure Russia’s economic presence and increased geopolitical and geo-economic interests in the Arctic.

Resistive Switching Characteristics of 10-nm-Thick Amorphous HoScO x Films Doped with Nb and Zn

In this study, 10-nm rare-earth metal-oxide (REMO) films, namely, pure HoScO x (HSO) and HoScO x doped with Nb (HSO-Nb) and Zn (HSO-Zn), were deposited to build resistive random access memory (RRAM) devices with a Pt/REMO/Pt structure using radio frequency magnetron sputtering. The results of x-ray diffraction and transmission electron microscopy showed that all as-deposited REMO films are featureless microstructures lacking long-range order. In all RRAM devices, layer structures were well adhered to each other with relatively smooth interfaces and no cracks or holes were observed. Hall measurements demonstrated n-type conduction in the as-deposited films. The addition of Nb and Zn increased carrier concentration and mobility of the HSO films and reduced electrical resistivity. The former was possibly caused by the electronic compensation of NbSc ··, thereby triggering the formation of polarons, and the latter was probably due to the increase in concentration of oxygen vacancies associated with acceptor doping. The RRAM devices revealed unipolar switching behavior characterized by a resistance ratio of more than three orders of magnitude, good endurance, and a long retention time. The switching behavior of the RRAM with amorphous HSO films was altered by the doping species. Doping with Nb and Zn decreased the forming voltage, facilitated the use of a smaller switching voltage, and increased the resistance ratio of high- and low-resistance states. The conduction mechanisms for the low resistive state and high resistive state were dominated by Ohmic conduction and trap-controlled space-charge-limited current mechanisms, respectively.

Vapor-phase dehydration of C4 unsaturated alcohols to 1,3-butadiene

Vapor-phase dehydration of C4 unsaturated alcohols such as 3-buten-1-ol, 2-buten-1-ol and 3-buten-2-ol were performed to produce 1,3-butadiene over various solid catalysts including ordinary solid acid catalysts such as Al2O3, SiO2-Al2O3, and TiO2 and basic rare earth metal oxides such as Yb2O3 and CeO2. In the reaction of 3-buten-1-ol, 1,3-butadiene could not be selectively produced because the acid catalysts decomposed 3-buten-1-ol into propylene. In contrast to the acid catalysts, CeO2 inhibited the decomposition of 3-buten-1-ol and showed a relatively high performance for the formation of 1,3-butadiene. In the dehydration of 2-buten-1-ol and 3-buten-2-ol, however, acid catalysts were effective for the formation of 1,3-butadiene. Among the tested catalysts, commercial SiO2-Al2O3 showed a relatively high catalytic performance, although it deactivated rapidly. We prepared a series of SiO2/Al2O3 catalysts by depositing SiO2 species onto Al2O3 support, and the SiO2/Al2O3 with a SiO2 content of 10wt.% showed more stable catalytic activity than the commercial SiO2-Al2O3. Furthermore, modification of SiO2/Al2O3 with Ag at a loading of 3–5wt.% was found to be efficient for inhibiting the coke formation and improving the catalytic stability of SiO2/Al2O3 in the dehydration of both 2-buten-1-ol and 3-buten-2-ol under hydrogen flow conditions.

Dosimetric properties of europium, gadolinium and cerium borosilicate glasses in application of electron beam dose measurements

Dosimetric properties of the borosilicate glasses (SiO2–B2O3–Al2O3–CaO–Na2O type) doped with Eu2O3, Gd2O3 and CeO2 rare earth oxides were investigated as potential materials for e-beam radiation dose measurement purposes. Glasses were prepared by classical melt-quench methodology with varying concentration of rare earth metal oxides from 0.5% to 1.5%. Linear electron accelerator was used for irradiation (17ns or 4μs duration pulsed mode). For lower dose range investigated (up to 900Gy) all samples studied exhibit good dosimetric response vs. dose absorbed, whereas for higher dose range (up to 30kGy), only materials doped with 0.5% and 1.5% of Gd2O3, as well as 0.5% CeO2 doped glasses were able to provide reproducible dosimetric response. Significant dose sensitivity variation was observed for all investigated glasses, which was dependent both on the rare earth metal concentration and the dose rate of radiation used for signal generation. For irradiated 0.5% Eu2O3, Gd2O3 and CeO2 doped glasses spectrally-resolved thermoluminescence measurements were performed. Results suggest different traps formation and stabilization mechanisms for each dopant, indicating Eu3+→Eu2+ ions reduction with simultaneous traps number consumption, glass network modification and traps stabilization for Gd2O3 doped glass and direct reduction of Ce4+→Ce3+ with simultaneous glass network disruption and increasing number of low energy traps. All investigated glass samples can be considered as potential dosimetric materials for electron beam delivered dose within the dose range up to 900Gy and with some limitations, regarding higher doses up to 15kGy.

Facile Synthesis of High Performance Platinum-Cerium Oxide Nanocatalysts for Methanol Oxidation

Electrooxidation of methanol has been studied intensively in the scientific community, and various catalysts have been developed for direct methanol fuel cells. In this study, platinum-cerium oxide nanoparticles have been synthesised, exhibiting high activity towards methanol electrooxidation. The materials were electrochemically characterised using rotating disk electrode, cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy methods. Scanning electron microscopy, X-Ray diffraction, inductively coupled plasma mass spectrometry and BET surface area mesurements were performed to characterise the physical properties of the synthesised materials. The methodology of the synthesis of the materials was straightforward and resource efficient. The synthesised nanocatalysts have a very uniform dispersion on the catalyst support material, and a narrow size distribution. Even at low platinum loadings, the materials have a lower overpotential towards methanol oxidation than commercial Pt-Vulcan catalysts. Based on cyclic voltammetry measurement data, the peak potential for the synthesised materials was 40 mV more negative than for the commercial material in the anodic potential scan, and 60 mV more negative in the cathodic potential scan. In addition to the high currents for methanol oxidation, extremely high currents were achieved in the cathodic potential sweep, in the region attributable to the oxidation of carbon monoxide. Methanol and carbon monoxide poisoning of the nanocatalysts was unnoticeable during the experiments. The results of the study lay a promising foundation for the investigation of nanocatalysts containing other rare earth metal oxides, as well as to the investigation of the electrooxidation of ethanol or other organic fuels on composite catalysts. Acknowlegements The authors wish to thank P. Paiste for ICP-MS measurements and J. Aruväli for XRD measurements This work was supported by the EU through the European Regional Development Fund TK141, the institutional research funding project IUT20-13 of the Estonian Ministry of Education and Research, the Estonian Energy Technology Program Project No. SLOKT10209T, Estonian Materials Technology project 3.2.1101.12-0019, Estonian Center of Excellence in Science Project TK117T, grant ETF9352 and PUT55.

Increased efficiency of dye-sensitized solar cells by addition of rare earth oxide microparticles into a titania acceptor

The addition of 400micron scale rare-earth metal oxide particles to the TiO2 nanoparticle acceptor layer of a dye-sensitized solar cell (DSSC) dramatically increases the efficiency of the solar cell by 10-30%. Oxidized neodymium powder, Nd2O3, combined with TiO2 nanoparticles forms a composite photoanode containing a wide range of Nd2O3 particle sizes. Based on absorbance measurements, the dye-uptake on the Nd2O3/TiO2 anode increases substantially compared to both a standard anode and to one made from a mixture of large and small TiO2 particles. Electrochemical impedance spectroscopy (EIS) shows a similar electron lifetime, but increased electron transport diffusion coefficient through the Nd2O3/TiO2 composite as compared to TiO2 only. This shows that the Nd2O3/TiO2 composite has a lower internal resistance for charge transport. This decrease in resistance, possibly due to the filling of trap states by the Nd2O3 valence or f-states, and increased dye uptake results in improved efficiency by simple incorporation of Nd2O3 powder.

Non-isothermal kinetics and mechanistic study of thermal decomposition of light rare earth metal nitrate hydrates using thermogravimetric analysis

The formation of light rare earth metal oxides such as CeO2, La2O3, Sm2O3, Nd2O3 and Pr2O3 from thermal decomposition of its nitrate precursors (Ce(NO3)3·6H2O, La(NO3)3·6H2O, Sm(NO3)3·6H2O, Nd(NO3)3·6H2O and Pr(NO3)3·6H2O) have been investigated by thermogravimetric analysis. The rare earth metal oxides obtained were characterized for the nature of chemical bonds and textural properties using FTIR and N2-physisorption analyses, respectively. The FTIR analysis of the rare earth metal precursors and the oxides showed that the OH– and NO– bonds depicting the presence of hydrated water molecules and nitrate disappeared after the thermal decomposition leaving out only the pure solid oxides. The kinetics data obtained from the thermogravimetric analysis were fitted into “model free” kinetic expressions such as Kissinger, Ozawa–Flynn–Wall to calculate the apparent activation energy of the solid-state decomposition reaction of the rare earth metal precursors. The kinetic parameters were further analyzed using Coat–Redfern model to determine the possible mechanism of the decomposition process. The calculated values of the activation energy obtained from both Kissinger and Ozawa–Flynn–Wall models were similar compared to that obtained from Coat–Redfern model. Highest activation energies of 230.26, 344.78, 320.2.78, 392.72 and 258.26 kJ mol−1 were obtained from decomposition of Ce(NO3)3·6H2O, La(NO3)3·6H2O, Sm(NO3)3·6H2O, Nd(NO3)3·6H2O and Pr(NO3)3·6H2O), respectively, using Kissinger model, while the analysis of the kinetic data using Ozawa–Flynn–Wall model gave the highest activation energies of 229.01, 350.56, 348.56, 392.72 and 388.56 kJ mol−1 for decomposition of Ce(NO3)3·6H2O, La(NO3)3·6H2O, Sm(NO3)3·6H2O, Nd(NO3)3·6H2O and Pr(NO3)3·6H2O), respectively. Thirteen different models were evaluated using Coat–Redfern models in order to determine the mechanisms that govern the decomposition process. Interestingly, two-dimensional diffusion mechanism with activation energy of 105.61, 107.61, 140.61, 144.52 and 154.78 kJ mol−1 was obtained for thermal decomposition of Ce(NO3)3·6H2O, La(NO3)3·6H2O, Sm(NO3)3·6H2O, Nd(NO3)3·6H2O and Pr(NO3)3·6H2O), respectively. The rare earth metal oxides obtained from this study finds potential application as supports, promoters and catalysts in the field of catalysis.

Folic acid conjugated amine functionalized cerium oxide nanoparticle for cancer targeted gene therapy

Event Abstract Back to Event Folic acid conjugated amine functionalized cerium oxide nanoparticle for cancer targeted gene therapy Kishor Sarkar1, Harini V. Krishnan1, G Vinoth Kumar2, K Suresh Babu2, Vinayak Sant1 and Shilpa Sant1, 3, 4 1 University of Pittsburgh, Department of Pharmaceutical Sciences, United States 2 Pondicherry University, Centre for Nano Science and Technology, India 3 University of Pittsburgh, Department of Bioengineering, United States 4 University of Pittsburgh, McGowan Institute for Regenerative Medicine, United States Introduction: Gene therapy has become alternative therapeutic approach to treat genetic diseases such as cancer[1]. Nonviral vectors have gained tremendous attraction over the viral vector due to its low toxicity, non-immunogenicity and low production cost[2]-[4]. Recently, rare earth metal oxide especially cerium oxide nanoparticle (CNP) has widely been used in biomedical fields such as drug delivery, bio-imaging, nanomedicine and tissue engineering application because of its inherent antioxidant activity, free radical scavenging activity and radioprotection to normal cell[5],[6]. It is also reported that CNP increased the ROS (reactive oxygen species) in cancer cell[7]. Therefore, we hypothesized that therapeutic gene (like siRNA, p53 etc.) delivery by means of CNP may give the dual therapeutic effect in conjugation with increased ROS level in cancer cell for the treatment of cancer. Here we report the functionalization of CNP by low molecular weight polyethyleneimine (LPEI, 2 kDa) followed by conjugation of folic acid (FA) for targeted gene delivery. Methods: LPEI was conjugated with CNP (LPEI-conj-CNP) through carboxylation followed by amidation reaction. Then, FA was reacted with LPEI-conj-CNP by carbodiimide to get FA-LPEI-conj- CNP. CNP/pDNA (enhanced green fluorescent protein, EGFP encoding pDNA) complexes were prepared at various weight ratios and characterized by agarose gel electrophoresis assay and dynamic light scattering (DLS). In vitro transfection efficiency, toxicity, ROS and underlying mechanistic pathway were also evaluated in HeLa cell. Results: Poor water dispersibility of CNP at physiological pH is a major drawback for biological field especially gene/ drug delivery application. CNP forms stable dispersion in acidic pH only. Despite the positive zeta potential of CNP, it did not bind any DNA at any weight ratio due to poor dispersibility. But, the DNA complexation capability of CNP significantly increased after conjugation of LPEI and LPEI-conj-CNP complexed all pDNA at a very low weight ratio of 0.5:1. Due to presence of lots of primary amine groups in LPEI, the water dispersibility of CNP increased drastically and resulted better DNA complexation through the cationic primary amine groups. The transfection efficiency of CNP increased after conjugation of LPEI but the efficiency increased significantly after FA conjugation with LPEI-conj-CNP. FA-LPEI-conj-CNP/pDNA complex at weight ratio of 15:1 showed highest transfection efficiency which also surpassed the efficiency offered by PEI (25 kDa) (Figure 1). It was also observed that FA-LPEI-conj-CNP internalized into cell via folate receptor as well as caveolae mediated pathway and resulted enhanced transfection efficiency. While LPEI-conj-CNP followed clathrin mediated pathway followed by lysosomal compartment entrapment and as a result showed low transfection efficiency. It was found that green fluorescence (fluorescent dichlorofluorescein, DCF obtained through oxidation of nonfluorescent dichlorofluorescein diacetate, DCFA by ROS) increased drastically by FA-LPEI-conj-CNP compared to all CNPs and H2O2 treated cell indicating the increase in ROS (Figure 2). Conclusion: The transfection efficiency as well as ROS of CNP increased after functionalization of CNP especially after FA conjugation. Therefore, FA-LPEI-conj-CNP may be useful candidate in nonviral gene therapy for cancer treatment by using its dual property including gene delivery and ROS enhancement. This work was financially supported by Start-up funds from University of Pittsburgh School of Pharmacy

REM-containing silicate concentrates

A new method of advanced complex processing of ores containing rare-earth elements (REE) is proposed to obtain porous X-ray amorphous aluminosilicate material with a stable chemical composition which concentrates oxides of rare-earth metals (REM). The ferromanganese oxide ores of Chuktukon deposit (Krasnoyarsk Region, RF) were used for the experiment. The obtained aluminosilicate material is appropriate for treatment with 5 - 15% solutions of mineral acids to leach REM.

Microbial induced synthesis of CeCO3OH and CeO2 hollow rods micro/nanostructure

The preparation of rare earth metal oxide (CeO2) using bacteria with urea hydrolysis is reported. A urease-generated bacterium, Bacillus pasteurii (BP), was used to induce the precipitation of CeCO3OH crystals in aqueous solutions containing urea and Ce3+ ions. The CeCO3OH crystals were subsequently converted to CeO2 by its thermal decomposition. Hollow rod shaped (CeCO3OH and CeO2) micro/nanostructure was prepared by simple method under ambient conditions. The 13C cross polarization magic-angle spinning NMR spectra revealed the possible explanation of the interaction of organic–inorganic moieties and precipitation of ceria on cell wall of bacteria. This is a promising route of bacteria-templated metal oxide crystals to produce hollow micro/nanostructures with potential in various technical applications. The synthesis of bacteria-guided metal oxides is cheap, non-toxic and eco-friendly.

Структурно-функциональный дизайн нанокомпозитных катализаторов для процессов продуцирующего и экологического катализа

This paper presents the results of studies targeted at designing novel high output nanocomposite catalysts, including those on the structured supports, for a number of producing and the environmental catalysis processes (reforming of methane and methanol producing hydrogen (synthesis gas), epoxidation of ethylene with nitrogen oxide(I), deep oxidation of methane, three-component (CO/NOx/CnHm) conversion, DeNOx-processes). Effects of modifying by the oxides of alkali and rare-earth metals, the role of promoters as well as an optimum combination of redox and acidic characteristics of the surface of transition metal oxide based catalysts are shown in the regulating and optimizing their functional properties.