02190nas a2200277 4500008004100000022001400041245009100055210006900146260009200215300001200307490000600319520125600325653001601581653001801597653001201615653001301627653001701640100001801657700001801675700001901693700002401712700001801736700002001754700001801774856012001792 2011 eng d a1936-661200aControlling stoichiometry in low temperature synthesis of La0.7Sr0.3MnO3 nanoparticles0 aControlling stoichiometry in low temperature synthesis of La07Sr a26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USAbAMER SCIENTIFIC PUBLISHERScFEB a424-4300 v43 a

Nanoparticles of complex oxides (<20 nm) are desirable for several applications in view of the diverse range of physical properties of such oxides. However the simultaneous presence of multiple cation precursors makes the corresponding chemical synthesis non-trivial with possible intermediate evolution of secondary phases. Such phases could react at high temperatures to form the desired stoichiometry, but this process is diffusion limited and can lead to larger particles. In this work we examine the role of three different reaction and growth controlling additives, namely dextran, citric acid and hexamine, on the synthesis of the well known colossal magneto-resistive (CMR) manganite La0.7Sr0.3MnO3. We demonstrate that phase evolutions differ significantly in the three cases, and the physical properties of the products also differ dramatically. Only dextran is shown to yield the desired phase with faceted nanoparticles at as low a temperature as 600 degrees C. A high saturation moment of similar to 47 emu/gm is realized at 10 K with a good square hysteresis loop. In 650 degrees C annealed sample, room temperature magnetization of similar to 15 emu/gm was obtained, which brings the nanoparticles in the applicability domain.

10aCitric acid10aComplex Oxide10aDextran10aHexamine10ahydrothermal1 aAzarifar, Ali1 aYadav, P., A.1 aChawla, A., K.1 aJog, Jyoti, Prakash1 aPatil, S., I.1 aChandra, Ramesh1 aOgale, S., B. uhttps://library.ncl.res.in/content/controlling-stoichiometry-low-temperature-synthesis-la07sr03mno3-nanoparticles-001862nas a2200265 4500008004100000022001400041245014100055210006900196260015900265300001200424490000700436520082700443653001901270653002901289653001601318653002301334653001401357653001301371653001501384653001501399653002201414653001201436100002301448856012501471 2012 eng d a1857-555200aBehavior of the transport and separation of lanthanum, yttrium and lutetium metal ions through a celluose fiber supported solid membrane0 aBehavior of the transport and separation of lanthanum yttrium an aSTS CYRIL & METHODIUS UNIV, FAC TECHNOL & METALLURGY, PO BOX 560, RUGER BOSKOVIC 16, SKOPJE, MK-1001, MACEDONIAbSOC CHEMISTS TECHNOLOGISTS MADECONIAcJan a255-2690 v313 a

A newly designed membrane cell was used to study the behavior of the transport and separation of lanthanum, yttrium and lutetium metal ions using a cellulose fiber supported solid membrane. The cellulose fiber membrane was prepared by the chemical modification of cellulose fiber using an esterification reaction with citric acid. Different experimental variables were investigated, such as time, membrane size, stirring of the source and receiving phases and the pH of the source phase. The use of different stripping agents in the receiving phase was explored, including nitric acid, hydrochloric acid, sodium nitrate, ammonium thiocyanate, D(2)EHPA, TBP, Aliquat-336, tartaric acid, EDTA and organic solvents. Pre-concentration of lanthanum, yttrium and lutetium metal ions from dilute solutions was carried out.

10abinary mixture10acellulose fiber membrane10aCitric acid10acomplexing reagent10aLanthanum10alutetium10ametal ions10aSeparation10atransport studies10ayttrium1 aGaikwad, Abaji, G. uhttps://library.ncl.res.in/content/behavior-transport-and-separation-lanthanum-yttrium-and-lutetium-metal-ions-through-002303nas a2200229 4500008004100000022001400041245013600055210006900191260009500260300001200355490000700367520140500374653001201779653001601791653002801807653001601835653002101851100002901872700001901901700002201920856013101942 2015 eng d a0263-876200aCatalytic upgrading of citric acid to environmental friendly tri-butyl citrate plasticizer over ultra stable phosphonated Y zeolite0 aCatalytic upgrading of citric acid to environmental friendly tri a165-189 RAILWAY TERRACE, DAVIS BLDG, RUGBY CV21 3HQ, ENGLANDbINST CHEMICAL ENGINEERScJUN a212-2190 v983 a

The catalytic synthesis of non-toxic/eco-friendly tributyl citrate (TBC) plasticizer by esterification of renewable citric acid (CA) with butanol would be completely sustainable route. In this context, catalytic performance of parent ultra stable Y (USY) and phosphonated USY catalysts were investigated for TBC synthesis. Parent USY and phosphonated USY catalysts were characterized by powder X-ray diffraction (XRD), N-2 adsorption-desorption, NH3 temperature programmed desorption (TPD), pyridine-Fourier Transform Infrared Spectroscopy (FTIR), FTIR, SEM, ICP. The influence of various process parameters such as phosphorous (P) loading (0 to 4 wt/%), catalyst loading (5-25%), molar ratio of CA to n-butanol (1:4 to 1:12), reaction temperature (383-423 K) and reaction time (1-5 h) have been investigated over USY catalyst with aim to maximize CA conversion and TBC yield. Amongst the studied catalysts, the 2% (w/w) P/USY was found to be highly potential catalyst with complete CA conversion (100%) and 93% TBC yield. The present method of using 2% (w/w) P/USY catalyst for the synthesis of TBC would be environmentally benign in the context of bio-renewable synthetic route, high catalytic activity, non-toxic product, long term stability and reusability of catalyst (five catalytic cycles). (c) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved,

10aButanol10aCitric acid10aheterogeneous catalysis10aPlasticizer10aTributyl citrate1 aNandiwale, Kakasaheb, Y.1 aGogoi, Pranjal1 aBokade, Vijay, V. uhttps://library.ncl.res.in/content/catalytic-upgrading-citric-acid-environmental-friendly-tri-butyl-citrate-plasticizer-over-002520nas a2200289 4500008004100000022001400041245010300055210006900158260000800227300001100235490000800246520160800254653001801862653001401880653001601894653002101910653002701931653002101958100001901979700001701998700001402015700001602029700001702045700002302062700001602085856012902101 2022 eng d a0169-131700aNa-montmorillonite to Fe(II)-Mt using ferrous citrate/ascorbate obtained by dissolving iron powder0 aNamontmorillonite to FeIIMt using ferrous citrateascorbate obtai cFEB a1063960 v2173 aBentonite containing montmorillonite (Mt) as the major clay mineral is the potential buffer material of engineered barrier system in the deep geological repository for high-level waste management. The corrosion products of canister/or overpack material (carbon steel) may alter the basic characteristics of bentonite through Fe/clay interaction and formation of FeMt to certain extent. A convenient method is required for quantitative preparation of Fe(II)-Mt because the only few direct methods reported have some limitations. For this, weak ferrous complexes having good solubility to facilitate the cation-exchange with bentonite is essential. Therefore, Fe(II)-citrate, Fe(II)-ascorbate and Fe(II)-citrate/ascorbate were obtained here by dissolving the iron powder (Fe0) in citric acid (CA), ascorbic acid (AA) and their equimolar mixtures from 25 mM to 300 mM at 70 °C under N2 atmosphere. The redox potential was measured to monitor the dissolution of Fe0 in these mild organic acids. Higher dissolution of Fe0 occurred in CA + AA mixture. The dissolved iron in the form of ferrous complex was reasonably stable in inert atmosphere, Fe2+/Fetotal ≈ 1. The parent clay mineral (bentonite, NaMt) was treated with Fe(II) − cit/asc to form Fe(II) − Mt. through cation exchange process. The CEC and ferrous to ferric ratio of the Fe(II)-Mt was close to the stoichiometric amount. The XRF, XRD, ac impedance, FT-IR, TGA/DSC, XPS and FE-SEM are used for further characterization. In-situ complexation reaction of interlayer Fe2+ ions in Fe(II)-Mt with o-phenanthroline was also observed.10aAscorbic acid10aBentonite10aCitric acid10aCr(VI) reduction10aFe(II)-montmorillonite10aIron dissolution1 aChikkamath, S.1 aManjanna, J.1 aMomin, N.1 aHegde, B.G.1 aNayaka, G.P.1 aKar, Aishwarya, S.1 aTomar, B.S. uhttps://library.ncl.res.in/content/na-montmorillonite-feii-mt-using-ferrous-citrateascorbate-obtained-dissolving-iron-powder