Home About us Contact
|
Home About us Contact | ||
|
|
||
Powder X-ray Diffraction Analysis (powder + x-ray_diffraction_analysis)
Selected AbstractsStereochemistry Determination by Powder X-Ray Diffraction Analysis and NMR Spectroscopy Residual Dipolar Couplings,ANGEWANDTE CHEMIE, Issue 31 2009Manuela Eine Frage der Technik: Dieselbe Konfiguration an C23,C26 wurde für das neue Steroidlactol Jaborosalactol,24 (1), isoliert aus Jaborosa parviflora, auf zwei unabhängigen Wegen bestimmt: NMR-spektroskopisch aus dipolaren Restkupplungen und durch Röntgenpulverbeugung. Herkömmliche NMR-spektroskopische Techniken wie die Analyse von NOEs und 3J -Kopplungskonstanten lieferten keine eindeutigen Ergebnisse. [source] Metathetic Reaction in Reverse Micelles: Synthesis of Nanostructured Alkaline-Earth Metal PhosphatesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2007Purnendu Parhi For the past few years, hydroxyapatite (HAp) has been identified as a potential biomaterial due to its excellent biocompatibility and bioactivity. The preparation of nanostructured HAp with controlled powder characteristics is a pre-requisite for processing it into useful biocomposites. Here, the synthesis of nanorods of calcium hydroxyapatite (Ca-HAp), strontium hydroxyapatite (Sr-HAp), and barium hydroxyapatite (Ba-HAp) by exploiting the metathetic reaction taking place in reverse micelles in the presence of cetyltrimethylammonium bromide has been reported. Powder X-ray diffraction analysis and thermogravimetric measurements confirm the formation of monophasic Ca-HAp and Sr-HAp. The growth of nanorods was further confirmed using transmission electron microscopy studies. The average lengths of Ca-HAp and Sr-HAp were ,60 and 30 nm, respectively. However, the preparation of Ba-HAp invariably yielded a multiphasic mixture with other competitive phases like BaHPO4 and Ba(H2PO4)2. [source] Synthesis of higher soluble nanostructured polyaniline by vapor-phase polymerization and determination of its crystal structureJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2009Sambhu Bhadra Abstract Higher soluble nanostructured polyaniline was prepared by vapor-phase polymerization after passing aniline vapor through an aqueous acidic solution of ammonium persulfate (PANI-V). Polyaniline was also synthesized by the conventional oxidative polymerization method (PANI-C) in an aqueous medium for the comparison of its properties with PANI-V. PANI-V exhibited lower conductivity but higher hydrophilicity and higher solubility (2,3 times) in different solvents, such as tetrahydrofuran, N -methyl-2-pyrrolidone, dimethylsulfoxide, N,N -dimethyl formamide, and m -cresol at room temperature compared with that of PANI-C. The thermal stability of PANI-V was higher than that of PANI-C. In-depth investigations of the crystal structures of PANI-C and PANI-V were performed through powder X-ray diffraction analysis. The PANI-V showed a less ordered structure with a lower crystallinity and crystallite size and with a higher d-spacing and interchain separation compared with PANI-C. The unit cell volume of PANI-V was significantly higher with a greater number of atoms in the unit cell than that of PANI-C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Enhancement of Tc(0) by Substitution of Gallium in the Bismuth-Based High- Tc Superconducting MaterialJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2008Muhammad Javed Iqbal We report the enhancement of the zero resistivity Tc(0) by 5.5 K i.e. from 104 to 109.5 K by substitution of gallium 1.34% of copper in the bismuth 2223 compound. A series of Ga-containing compounds Bi2Pb0.4Sr2Ca2Cu3,xGaxOy (x=0.00, 0.02, 0.04, 0.06, and 0.08) are synthesized by the solid-state reaction method. The samples are characterized by measurements of their dc electrical resistivity and ac magnetic susceptibility and by the powder X-ray diffraction analysis. It is noted that the high- Tc (2223) phase increases from 57.55% in an undoped sample to 92.99% in samples containing a low concentration of gallium i.e. x,0.04. [source] Synthesis, structural characterization, biological activity and thermal study of tri- and diorganotin(IV) complexes of Schiff base derived from 2-aminomethylbenzimidazoleAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2009Mala Nath Abstract This report deals with the synthesis and structural features of tri- and diorganotin(IV) complexes of the general formulae, RnSn(L)m [n = 3, m = 1, R = Me, n -Bu and Ph; n = 2, m = 2, R = Me, n -Bu, n -Oct and Ph; HL = Schiff base derived from the condensation of 2-aminomethylbenzimidazole (ambmz) and salicylaldehyde (abbreviated as HL or Hsal-ambmz)]. The newly synthesized complexes were characterized by elemental analysis, molar conductance, electronic, infrared, far-infrared, 1H NMR, 13C NMR, 119Sn NMR and 119Sn Mössbauer spectral studies. Thermal studies of all of the synthesized complexes were also carried out using thermogravimetry,differential thermal analysis-derivative thermogravimetric (TG-DTA-DTG) techniques. The residues thus obtained were characterized by infrared and powder X-ray diffraction analysis. The bioassay results of anti-inflammatory activity (using the carrageenan-induced paw edema bioassay in rats) and acute toxicity (LD50) of the synthesized derivatives indicated that diorganotin(IV) derivatives (19.75,22.23% inhibition) show better activity as compared with triorganotin(IV) derivatives (10.32,17.86% inhibition). Copyright © 2009 John Wiley & Sons, Ltd. [source] | |||||||||||||