01866nas a2200241 4500008004100000022001400041245009100055210006900146260007400215300001200289490000700301520101100308653002301319653002301342653001401365653001901379653002501398653002401423100002101447700002201468700001801490856011601508 2009 eng d a0928-070700aSynthesis of Si-MCM-41 from ternary SiO2-CTAOH-H2O system via dry gel conversion route0 aSynthesis of SiMCM41 from ternary SiO2CTAOHH2O system via dry ge aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcAUG a244-2500 v513 a

Steam assisted dry gel conversion method was employed for the synthesis of Si-MCM-41 from ternary SiO2:CTAOH:H2O systems wherein fumed silica was used as a source of silica. The influence of synthesis time, molar ratios of CTAOH/SiO2 in dry gel and the water content at the bottom of autoclave on the quality and formation of mesophases has been investigated. Powder XRD, N-2 adsorption-desorption, TEM and hydrothermal stability test were the techniques used for sample characterization. Keeping molar ratio of CTAOH/SiO2 constant, shorter synthesis time, lower unit cell parameter and d spacing were observed when steam assisted dry gel conversion method was employed in place of conventional hydrothermal method. There exists an optimum lower limit for water content at the bottom of autoclave for reducing the synthesis period. Keeping synthesis temperature and CTAOH/SiO2 molar ratio fixed, Si-MCM-41 with improved hydrothermal stability was obtained by steam assisted dry gel conversion route.

10aDry gel conversion10apowder diffraction10aSi-MCM-4110aSol-gel growth10aStructural stability10aTextural properties1 aTaralkar, U., S.1 aNiphadkar, P., S.1 aJoshi, P., N. uhttps://library.ncl.res.in/content/synthesis-si-mcm-41-ternary-sio2-ctaoh-h2o-system-dry-gel-conversion-route-002581nas a2200253 4500008004100000022001400041245014900055210006900204260006900273300001200342490000800354520161400362653001501976653002301991653003002014653002402044653002302068653001802091100002202109700002802131700001702159700002502176856012602201 2014 eng d a0254-058400aPreparation and characterization of porous fly ash/NiFe2O4 composite: promising adsorbent for the removal of congo red dye from aqueous solution0 aPreparation and characterization of porous fly ashNiFe2O4 compos aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcNOV a371-3790 v1483 a

A series of fly ash/NiFe2O4 composites were prepared using fly ash and aqueous solutions of Ni, Fe nitrate salts and NaOH by co-precipitation followed by calcination method. The % mass ratio of fly ash: NiFe2O4 was varied in the range of 0:100 to 100:0. Samples were characterized by powder XRD, SEM, FTIR and N-2 adsorption-desorption measurements. These samples were further evaluated for their adsorptive performance in removal of Congo red (CR) dye from an aqueous solution. In all the composites, spinel nickel ferrite phase was found to be capable to get anchored with the fly ash surface and exhibited more crystalline nature as compared to pure NiFe2O4 phase. The BET surface area and porous character of the composite were found to increase with the decrease in the contribution of the fly ash, reach to maximum and then decreases on further decrease in fly ash. The composite having % mass ratio of fly ash: NiFe2O4 = 50:50 exhibited maximum CR adsorption from the aqueous solution on account of the higher BET surface area, more porous character, favorable condition for diffusion of dye molecules and combined effect of chemisorption and physisorption. Under optimum conditions, it has shown the recyclability with adsorption capacity of the magnitude 23.33 mg g(-1), which is much higher than individual fly ash, NiFe2O4 and other composites. The sorption data provided good fit with pseudo-second order kinetic model. The analyses of the adsorption data indicated that, the Langmuir model provides better correlation with the experimental data. (C) 2014 Elsevier B.V. All rights reserved.

10aAdsorption10aComposite material10aElectron microscopy (SEM)10aInorganic compounds10apowder diffraction10aPrecipitation1 aSonar, Shilpa, K.1 aNiphadkar, Prashant, S.1 aMayadevi, S.1 aJoshi, Praphulla, N. uhttps://library.ncl.res.in/content/preparation-and-characterization-porous-fly-ashnife2o4-composite-promising-adsorbent-002279nas a2200217 4500008004100000022001400041245007500055210006900130260006900199300001000268490000800278520153400286653001701820653001901837653002301856653001801879100001801897700001801915700001901933856010901952 2014 eng d a0254-058400aSynthesis and luminescence of graphene-nano calcium sulphide composite0 aSynthesis and luminescence of graphenenano calcium sulphide comp aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcSEP a57-640 v1473 a

Graphene-nanocrystalline calcium sulphide has been synthesized using in-situ reduction of calcium salt and graphene oxide. Graphene oxide was prepared using Hummer's method. Surface morphology and crystal structure of samples were observed by transmission electron microscopy (TEM) and X-Ray diffraction (XRD). Ultra thin graphene and graphene oxide sheets with size ranging between tens to several hundreds of square nanometers are observed in TEM images. The TEM micrographs of G-CaS show that CaS particles are embedded in graphene sheets and the average particle size of CaS particles in the composite is less than 50 nm. The reduction in the intensity of various functional groups in FTIR spectrum also confirms the formation of graphene. The UV-Visible spectra of CaS shows absorption peak at 220 nm with a small shoulder at 250 nm whereas in G-CaS 220 nm absorption peak has reduced intensity and the shoulder at 250 nm has now shifted to 270 nm due to modification in the defect structure of CaS by graphene. CaS and G-CaS shows photoluminescence emission at 470 nm (lambda(exc.) = 375 nm) and 440 nm (lambda(exc.) = 350 nm) respectively, however emission intensity of G-CaS is relatively lower than CaS. Although the emission intensity is found to be lower than CaS, addition of CaS to graphene in G-CaS complex has made graphene luminescent. XPS spectra also indicate reduction of various oxygen containing functional groups in highly reduced graphene oxide and G-CaS. (C) 2014 Elsevier B.V. All rights reserved.

10aLuminescence10aNanostructures10apowder diffraction10aPrecipitation1 aSharma, Geeta1 aPatil, K., R.1 aGosavi, S., W. uhttps://library.ncl.res.in/content/synthesis-and-luminescence-graphene-nano-calcium-sulphide-composite-004390nas a2200265 4500008004100000022001400041245017900055210006900234260007400303300001400377490000700391520332100398653003003719653004303749653001403792653002203806653002103828653002603849653002303875653002803898100002503926700002403951700002403975856012503999 2015 eng d a2053-229600aCrystal structures of the pyrazinamide-p-aminobenzoic acid (1/1) cocrystal and the transamidation reaction product 4-(pyrazine-2-carboxamido)-benzoic acid in the molten state0 aCrystal structures of the pyrazinamidepaminobenzoic acid 11 cocr a2 ABBEY SQ, CHESTER, CH1 2HU, ENGLANDbINT UNION CRYSTALLOGRAPHYcNOV a1010-U2760 v713 a

The synthesis of pharmaceutical cocrystals is a strategy to enhance the performance of active pharmaceutical ingredients (APIs) without affecting their therapeutic efficiency. The 1: 1 pharmaceutical cocrystal of the antituberculosis drug pyrazinamide (PZA) and the cocrystal former p-aminobenzoic acid (p-ABA), C7H7NO2- C5H5N3O, (1), was synthesized successfully and characterized by relevant solid-state characterization methods. The cocrystal crystallizes in the monoclinic space group P21/n containing one molecule of each component. Both molecules associate via intermolecular O-H center dot center dot center dot O and NH center dot center dot center dot O hydrogen bonds [O center dot center dot center dot O = 2.6102 (15)angstrom and O-H center dot center dot center dot O = 168.3 (19)degrees; N center dot center dot center dot O = 2.9259 (18) angstrom and N-H center dot center dot center dot O = 167.7 (16)degrees] to generate a dimeric acidamide synthon. Neighbouring dimers are linked centrosymmetrically through N-H center dot center dot center dot O interactions [N center dot center dot center dot O = 3.1201 (18) angstrom and N-H center dot center dot center dot O = 136.9 (14)degrees] to form a tetrameric assembly supplemented by C-H center dot center dot center dot N interactions [C center dot center dot center dot N = 3.5277 (19) angstrom and C-H center dot center dot center dot N = 147 degrees]. Linking of these tetrameric assemblies through N-H center dot center dot center dot O [N center dot center dot center dot O = 3.3026 (19) angstrom and N-H center dot center dot center dot O = 143.1 (17)degrees], NH center dot center dot center dot N [N center dot center dot center dot N = 3.221 (2) angstrom and N-H center dot center dot center dot N = 177.9 (17)degrees] and C-H center dot center dot center dot O [C center dot center dot center dot O = 3.5354 (18) angstrom and C-H center dot center dot center dot O = 152 degrees] interactions creates the twodimensional packing. Recrystallization of the cocrystals from the molten state revealed the formation of 4-(pyrazine-2-carboxamido) benzoic acid, C12H9N3O3, (2), through a transamidation reaction between PZA and p-ABA. Carboxamide (2) crystallizes in the triclinic space group P1 with one molecule in the asymmetric unit. Molecules of (2) form a centrosymmetric dimeric homosynthon through an acid-acid O-H center dot center dot center dot O hydrogen bond [O center dot center dot center dot O = 2.666 (3) angstrom and O-H center dot center dot center dot O = 178 (4) degrees]. Neighbouring assemblies are connected centrosymmetrically via a C-H center dot center dot center dot N interaction [C center dot center dot center dot N = 3.365 (3) angstrom and C-H center dot center dot center dot N = 142 degrees] engaging the pyrazine groups to generate a linear chain. Adjacent chains are connected loosely via C-H center dot center dot center dot O interactions [C center dot center dot center dot O = 3.212 (3) angstrom and CH center dot center dot center dot O = 149 degrees] to generate a two-dimensional sheet structure. Closely associated two-dimensional sheets in both compounds are stacked via aromatic pi-stacking interactions engaging the pyrazine and benzene rings to create a threedimensional multi-stack structure.

10aacid-amide hetero-synthon10aactive pharmaceutical ingredient (API)10acocrystal10acrystal structure10ahydrogen bonding10amolten-state reaction10apowder diffraction10atransamidation reaction1 aThorat, Shridhar, H.1 aSahu, Sanjay, Kumar1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/crystal-structures-pyrazinamide-p-aminobenzoic-acid-11-cocrystal-and-transamidation-1