Functional biocompatible magnetite-cellulose nanocomposite fibrous networks: Characterization by fourier transformed infrared spectroscopy, X-ray powder diffraction and field emission scanning electron microscopy analysis.

PubMed

Habibi, Neda

2015-02-05

The preparation and characterization of functional biocompatible magnetite-cellulose nano-composite fibrous material is described. Magnetite-cellulose nano-composite was prepared by a combination of the solution-based formation of magnetic nano-particles and subsequent coating with amino celluloses. Characterization was accomplished using X-ray powder diffraction (XRD), fourier transformed infrared (FTIR) and field emission scanning electron microscopy (FESEM) analysis. The peaks of Fe3O4 in the XRD pattern of nanocomposite confirm existence of the nanoparticles in the amino cellulose matrix. Magnetite-cellulose particles exhibit an average diameter of roughly 33nm as demonstrated by field emission scanning electron microscopy. Magnetite nanoparticles were irregular spheres dispersed in the cellulose matrix. The vibration corresponding to the NCH3 functional group about 2850cm(-1) is assigned in the FTIR spectra. Functionalized magnetite-cellulose nano-composite polymers have a potential range of application as targeted drug delivery system in biomedical field. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis and optical properties of Mg-Al layered double hydroxides precursor powders

NASA Astrophysics Data System (ADS)

Lin, Chia-Hsuan; Chu, Hsueh-Liang; Hwang, Weng-Sing; Wang, Moo-Chin; Ko, Horng-Huey

2017-12-01

The synthesis and optical properties of Mg-Al layered double hydroxide (LDH) precursor powders were investigated using X-ray diffraction (XRD), Fourier transform-infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED), high-resolution TEM (HRTEM), UV-transmission spectrometer, and fluorescence spectrophotometer. The FT-IR results show that the intense absorption at around 1363-1377 cm-1 can be assigned to the antisymmetric ν3 mode of interlayer carbonate anions because the LDH phase contains some CO32-. The XRD results show that all of the Mg-Al LDH precursor powders contain only a single phase of [Mg0.833Al0.167(OH)2](CO3)0.083.(H2O)0.75 but have broad and weak intensities of peaks. All of Mg-Al LDHs precursor powders before calcination have the same photoluminescence (PL) spectra. Moreover, these spectra were excited at λex = 235 nm, and the broad emission band was in the range 325-650 nm. In the range, there were relatively strong intensity at around 360, 407 and 510 nm, respectively.

Fabrication of Spherical AlSi10Mg Powders by Radio Frequency Plasma Spheroidization

NASA Astrophysics Data System (ADS)

Wang, Linzhi; Liu, Ying; Chang, Sen

2016-05-01

Spherical AlSi10Mg powders were prepared by radio frequency plasma spheroidization from commercial AlSi10Mg powders. The fabrication process parameters and powder characteristics were investigated. Field emission scanning electron microscope, X-ray diffraction, laser particle size analyzer, powder rheometer, and UV/visible/infrared spectrophotometer were used for analyses and measurements of micrographs, phases, granulometric parameters, flowability, and laser absorption properties of the powders, respectively. The results show that the obtained spherical powders exhibit good sphericity, smooth surfaces, favorable dispersity, and excellent fluidity under appropriate feeding rate and flow rate of carrier gas. Further, acicular microstructures of the spherical AlSi10Mg powders are composed of α-Al, Si, and a small amount of Mg2Si phase. In addition, laser absorption values of the spherical AlSi10Mg powders increase obviously compared with raw material, and different spectra have obvious absorption peaks at a wavelength of about 826 nm.

Effect of preparation conditions on the nanostructure of hydroxyapatite and brushite phases

NASA Astrophysics Data System (ADS)

Mansour, S. F.; El-dek, S. I.; Ahmed, M. A.; Abd-Elwahab, S. M.; Ahmed, M. K.

2016-10-01

Hydroxyapatite (HAP) and dicalcium phosphate dihydrate (brushite) nanoparticles were prepared by co-precipitation method. The obtained products were characterized by X-ray powder diffraction (XRD), Fourier transformation infra-red spectroscopy (FTIR) and thermo-gravimetric analysis (TGA). Scanning electron microscopy (SEM) and transmission electron microscope (TEM) were used to investigate the morphology of the powdered samples as well as their microstructure, respectively. Brushite samples were obtained in a spherical shape, while hydroxyapatite was formed in a needle and rice shape depending on the pH value.

High temperature phase stability in Li{sub 0.12}Na{sub 0.88}NbO{sub 3}: A combined powder X-ray and neutron diffraction study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, S. K.; Krishna, P. S. R.; Shinde, A. B.

2015-09-07

The phase stabilities of ecofriendly piezoelectric material of lithium doped sodium niobate for composition Li{sub 0.12}Na{sub 0.88}NbO{sub 3} (LNN12) have been investigated by a combination of powder X-ray and neutron diffraction techniques in the temperature range of 300–1100 K. We observed interesting changes with appearance or disappearance of the super-lattice reflections in the powder diffraction patterns. Unambiguous experimental evidence is shown for coexistence of paraelectric and ferroelectric orthorhombic phases in the temperature range of 525 K to 675 K. We identified the correct crystal structure of LNN12 with temperature and correlated it with observed anomaly in the physical properties. Identification of crystal structuremore » also helps in the mode assignments in Raman and infrared spectroscopies. We argued that application of chemical pressure as a result of Li substitution in NaNbO{sub 3} matrix favors the freezing of zone centre phonons in contrast to the freezing of zone boundary phonons in pure NaNbO{sub 3} with the variation of temperature.« less

The effect of polymorphism on powder compaction and dissolution properties of chemically equivalent oxytetracycline hydrochloride powders.

PubMed

Liebenberg, W; de Villiers, M M; Wurster, D E; Swanepoel, E; Dekker, T G; Lötter, A P

1999-09-01

In South Africa, oxytetracycline is identified as an essential drug; many generic products are on the market, and many more are being developed. In this study, six oxytetracycline hydrochloride powders were obtained randomly from manufacturers, and suppliers were compared. It was found that compliance to a pharmacopoeial monograph was insufficient to ensure the optimum dissolution performance of a simple tablet formulation. Comparative physicochemical raw material analysis showed no major differences with regard to differential scanning calorimetry (DSC), infrared (IR) spectroscopy, powder dissolution, and particle size. However, the samples could be divided into two distinct types with respect to X-ray powder diffraction (XRD) and thus polymorphism. The two polymorphic forms had different dissolution properties in water or 0.1 N hydrochloride acid. This difference became substantial when the dissolution from tablets was compared. The powders containing form A were less soluble than that containing form B.

Aqueous Combustion Synthesis and Characterization of Nanosized Tetragonal Zirconia Single Crystals

NASA Astrophysics Data System (ADS)

Reddy, B. S. B.; Mal, Indrajit; Tewari, Shanideep; Das, Karabi; Das, Siddhartha

2007-08-01

Nanocrystalline zirconia powder has been synthesized by an aqueous combustion synthesis route using glycine as fuel and nitrate as oxidizer. The powders have been prepared by using different glycine to zirconyl nitrate molar ratios (G/N). The powders produced with different G/N ratios have been characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) to determine the parameters resulting from powder with attractive properties. The theoretical combustion temperature (T ad ) has been calculated for different G/N ratios, and it is correlated with powder characteristics. An attempt is also made to explain the stability of tetragonal zirconia on the basis of extrinsic factors such as the morphology of nanocrystallites. Nanocrystalline metastable tetragonal zirconia (˜25 nm) powder (TZ) with disc-shaped morphology has been produced with a weak agglomeration in fuel deficient mixtures.

Template-free solution approach to synthesize CdS dendrites with SCN based ionic liquid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Kangfeng; Li, Jiajia; Cheng, Xianyi

2011-07-15

Highlights: {yields} Template-free solution approach to synthesize CdS hierarchical dendrites. {yields} The 1-butyl-3-methlyimidazole thiocyanate ([BMIM][SCN]) plays doubly functional roles in the progress. {yields} The CdS hierarchical dendrites exhibit a more intense emission at 710 nm belongs to infrared band. -- Abstract: Cadmium sulfide dendrites were synthesized by a facile hydrothermal treatment from CdCl{sub 2} and ionic liquid 1-butyl-3-methlyimidazole thiocyanate acted both as sulfur source and surfactant. The product was characterized by means of X-ray powder diffraction and scanning electron microscopy. X-ray powder diffraction studies indicated that the product was well-crystallized hexagonal phase of CdS, and the scanning electron microscopy imagesmore » showed that the obtained powders consisted of a wealth of well-defined CdS dendritic microstructures with a pronounced trunk and highly ordered branches. The UV-Vis and photoluminescence spectroscopy measurements were taken as well. The possible formation mechanism of CdS dendrites was simply proposed in the end.« less

Characterization of food additive-potato starch complexes by FTIR and X-ray diffraction.

PubMed

Dankar, Iman; Haddarah, Amira; Omar, Fawaz E L; Pujolà, Montserrat; Sepulcre, Francesc

2018-09-15

Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques were used to study the effect of four food additives, agar, alginate, lecithin and glycerol, at three different concentrations, 0.5, 1 and 1.5%, on the molecular structure of potato puree prepared from commercial potato powder. Vibrational spectra revealed that the amylose-amylopectin skeleton present in the raw potato starch was missing in the potato powder but could be fully recovered upon water addition when the potato puree was prepared. FTIR peaks corresponding to water were clearly present in the potato powder, indicating the important structural role of water molecules in the recovery of the initial molecular conformation. None of the studied puree samples presented a crystalline structure or strong internal order. A comparison of the FTIR and XRD results revealed that the additives exerted some effects, mainly on the long-range order of the starch structure via interacting with and changing -OH and hydrogen bond interactions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Same Precursor, Two Different Products: Comparing the Structural Evolution of In–Ga–O “Gel-Derived” Powders and Solution-Cast Films Using Pair Distribution Function Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, Suzannah R.; Woods, Keenan N.; Plassmeyer, Paul N.

Amorphous metal oxides are central to a variety of technological applications. In particular, indium gallium oxide has garnered attention as a thin-film transistor channel layer material. In this work we examine the structural evolution of indium gallium oxide gel-derived powders and thin films using infrared vibrational spectroscopy, X-ray diffraction, and pair distribution function (PDF) analysis of X-ray total scattering from standard and normal incidence thin-film geometries (tfPDF). We find that the gel-derived powders and films from the same aqueous precursor evolve differently with temperature, forming mixtures of Ga-substituted In2O3 and In-substituted β-Ga2O3 with different degrees of substitution. X-ray total scatteringmore » and PDF analysis indicate that the majority phase for both the powders and films is an amorphous/nanocrystalline β-Ga2O3 phase, with a minor constituent of In2O3 with significantly larger coherence lengths. This amorphous β-Ga2O3 phase could not be identified using the conventional Bragg diffraction techniques traditionally used to study crystalline metal oxide thin films. The combination of Bragg diffraction and tfPDF provides a much more complete description of film composition and structure, which can be used to detail the effect of processing conditions and structure–property relationships. This study also demonstrates how structural features of amorphous materials, traditionally difficult to characterize by standard diffraction, can be elucidated using tfPDF.« less

Green biosynthesis of silver nanoparticles using Curcuma longa tuber powder

PubMed Central

Shameli, Kamyar; Ahmad, Mansor Bin; Zamanian, Ali; Sangpour, Parvanh; Shabanzadeh, Parvaneh; Abdollahi, Yadollah; Zargar, Mohsen

2012-01-01

Green synthesis of noble metal nanoparticles is a vastly developing area of research. Metallic nanoparticles have received great attention from chemists, physicists, biologists, and engineers who wish to use them for the development of a new-generation of nanodevices. In this study, silver nanoparticles were biosynthesized from aqueous silver nitrate through a simple and eco-friendly route using Curcuma longa tuber-powder extracts, which acted as a reductant and stabilizer simultaneously. Characterizations of nanoparticles were done using different methods, which included ultraviolet-visible spectroscopy, powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray fluorescence spectrometry, and Fourier-transform infrared spectroscopy. The ultraviolet-visible spectrum of the aqueous medium containing silver nanoparticles showed an absorption peak at around 415 nm. Transmission electron microscopy showed that mean diameter and standard deviation for the formation of silver nanoparticles was 6.30 ± 2.64 nm. Powder X-ray diffraction showed that the particles are crystalline in nature, with a face-centered cubic structure. The most needed outcome of this work will be the development of value-added products from C. longa for biomedical and nanotechnology-based industries. PMID:23341739

Operando Synchrotron X-ray Powder Diffraction and Modulated-Excitation Infrared Spectroscopy Elucidate the CO2 Promotion on a Commercial Methanol Synthesis Catalyst.

PubMed

Martin, Oliver; Mondelli, Cecilia; Cervellino, Antonio; Ferri, Davide; Curulla-Ferré, Daniel; Pérez-Ramírez, Javier

2016-09-05

Optimal amounts of CO2 are added to syngas to boost the methanol synthesis rate on Cu-ZnO-Al2 O3 in the industrial process. The reason for CO2 promotion is not sufficiently understood at the particle level due to the catalyst complexity and the high demands of characterization under true reaction conditions. Herein, we applied operando synchrotron X-ray powder diffraction and modulated-excitation infrared spectroscopy on a commercial catalyst to gain insights into its morphology and surface chemistry. These studies unveiled that Cu and ZnO agglomerate and ZnO particles flatten under CO/H2 and/or CO2 /H2 . Under the optimal CO/CO2 /H2 mixture, sintering is prevented and ZnO crystals adopt an elongated shape due to the minimal presence of the H2 O byproduct, enhancing the water-gas shift activity and thus the methanol production. Our results provide a rationale to the CO2 promotion emphasizing the importance of advanced analytical methods to establish structure-performance relations in heterogeneous catalysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Upconversion luminescence in BaMoO{sub 4}:Pr{sup 3+} phosphor for display devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soni, Abhishek Kumar; Rai, Vineet Kumar, E-mail: vineetkrrai@yahoo.co.in

2015-08-28

The frequency upconversion is an important nonlinear optical property by which near infrared light is converted into the visible light. The BaMoO{sub 4}:Pr{sup 3+} powder phosphor has been synthesized by solid state reaction method. The upconversion emission bands are recorded under the excitation of 808 nm diode laser. The phase formation of the prepared phosphor has been identified by powder X-ray diffraction (XRD) technique. The upconversion emission mechanism and colour coordinate have been explained by using energy level and CIE (International Commission on Illumination) chromaticity diagram study, respectively.

The effect of ultrasonic irradiation on the crystallinity of nano-hydroxyapatite produced via the wet chemical method.

PubMed

Barbosa, Michelle C; Messmer, Nigel R; Brazil, Tayra R; Marciano, Fernanda R; Lobo, Anderson O

2013-07-01

Nanohydroxyapatite (nHAp) powders were produced via aqueous precipitation by adopting four different experimental conditions, assisted or non-assisted by ultrasound irradiation (UI). The nHAp powders were characterized by X-ray diffraction, energy-dispersive X-ray fluorescence, Raman and attenuated total reflection Fourier transform infrared spectroscopies, which showed typical surface chemical compositions of nHAp. Analysis found strong connections between UI and the crystallization process, crystal growth properties, as well as correlations between calcination and substitution reactions. Copyright © 2013 Elsevier B.V. All rights reserved.

Elaboration of the hydroxyapatite with different precursors and application for the retention of the lead.

PubMed

Meski, S; Ziani, S; Khireddine, H; Yataghane, F; Ferguene, N

2011-01-01

Carbonate hydroxyapatite (CHAP) was synthesized from different precursors; synthetic (CaCO3 and Ca(OH)2) and natural (egg shell before and after calcinations at 900 degrees C) under different conditions and characterized by using TG/DTG analysis, X-ray powder diffraction (XRD) method and Fourier transform infrared (FT-IR) spectroscopy techniques. The results of these analyses indicate that the four powders present the same structure of hydroxyapatite. Furthermore the four powders obtained were used for the retention of lead. The results obtained indicated that all powders present high adsorption capacity for lead, but from environmental and economic views, the hydroxyapatite synthesized from eggshell no calcined (HA2) is most advantageous. The influence of different sorption parameters, such as: initial metal concentration, equilibration time, solution pH and sorbent dosage was studied and discussed.

X-ray diffraction, spectroscopic and mechanical studies on potential organic NLO materials of metaNitroaniline and N-3-Nitrophenyl Acetamide single crystals

NASA Astrophysics Data System (ADS)

Senthil, S.; Madhavan, J.

2015-02-01

In the present paper, attempts were made to grow good quality metaNitroaniline (mNA) and N-3-Nitrophenyl (3-NAA) single crystals. The lattice parameter values from the Powder X-ray diffraction pattern confirms that mNA belongs to orthorhombic crystal system with the unit cell parameter values of a = 6.501 Å, b = 19.330 Å and c = 5.082 Å with space group Pbc21. Similarly the powder XRD data indicates that 3-NAA crystal retained its monoclinic structure with lattice parameter values a = 9.762 Å, b =13.287 Å, c =13.226 Å, and β = 102.99°. Investigation has been carried out to assign the vibrational frequencies of the grown crystals by Fourier Transform infrared spectroscopy technique. The SHG efficiency of mNA and 3NAA was determined by Kurtz and Perry powder technique. The Optical absorption study confirms the suitability of the crystals for device applications. The mechanical properties of the grown crystals have been studied using Vickers microhardness tester.

Phase modification of copper phthalocyanine semiconductor by converting powder to thin film

NASA Astrophysics Data System (ADS)

Ai, Xiaowei; Lin, Jiaxin; Chang, Yufang; Zhou, Lianqun; Zhang, Xianmin; Qin, Gaowu

2018-01-01

Thin films of copper phthalocyanine (CuPc) semiconductor were deposited on glass substrates by a thermal evaporation system using the CuPc powder in a high vacuum. The crystal structures of both the films and the powder were measured by the X-ray diffraction spectroscopy technique. It is observed that CuPc films only show one peak at 6.84°, indicating a high texture of α phase along (200) orientation. In comparison, CuPc powder shows a series of peaks, which are confirmed from the mixture of both α and β phases. The effects of substrate anneal temperature on the film structure, grain size and optical absorption property of CuPc films were also investigated. All the films are of α phase and the full width of half maximum for (200) diffraction peak becomes narrow with increasing the substrate temperatures. The average grain size calculated by the Scherrer's formula is 33.63 nm for the film without anneal, which is increased up to 58.29 nm for the film annealed at 200 °C. Scanning electron microscope was further measured to prove the growth of crystalline grain and to characterize the morphologies of CuPc films. Ultraviolet-visible absorption spectra were employed to study the structure effect on the optical properties of both CuPc films and powder. Fourier Transform infrared spectroscopy was used to identify the crystalline nature of both CuPc powder and film.

Synthesis and optical properties of polycrystalline Li2Al2B2O7 (LABO)

NASA Astrophysics Data System (ADS)

Dagdale, S. R.; Muley, G. G.

2016-05-01

A polycrystalline lithium aluminum borate (Li2Al2B2O7, LABO) has been synthesized by using simple solid-state technique. The obtained LABO polycrystalline was characterized by powder X-ray diffraction; Fourier transform infrared (FT-IR) spectroscopy and second harmonic generation (SHG) efficiency measurement. The functional groups were identified using the FT-IR spectroscopic data. The SHG efficiency of the polycrystalline material was obtained by the classic Kurtz powder technique using a fundamental wavelength 1064 nm of Nd:YAG laser and it is found to be 1.4 times that of potassium dihydrogen phosphate (KDP).

Hydrothermal Synthesis and Characterization of a Metal-Organic Framework by Thermogravimetric Analysis, Powder X-Ray Diffraction, and Infrared Spectroscopy: An Integrative Inorganic Chemistry Experiment

ERIC Educational Resources Information Center

Crane, Johanna L.; Anderson, Kelly E.; Conway, Samantha G.

2015-01-01

This advanced undergraduate laboratory experiment involves the synthesis and characterization of a metal-organic framework with microporous channels that are held intact via hydrogen bonding of the coordinated water molecules. The hydrothermal synthesis of Co[subscript 3](BTC)[subscript 2]·12H[subscript 2]O (BTC = 1,3,5-benzene tricarboxylic acid)…

Structural, optical and photo thermal properties of Er3+:Y2O3 doped PMMA nanocomposite

NASA Astrophysics Data System (ADS)

Tabanli, Sevcan; Eryurek, Gonul

2018-02-01

Thermal decomposition technique was employed to synthesize of phosphors of yttria (Y2O3) doped with erbium (Er3+) ions. After the synthesized procedure, the nano-sized crystalline powders were annealed at 800oC for 24 h. Annealed powders were embedded in poly(methyl methacrylate) (PMMA) by free radical polymerization to fabricate nanocomposite polymer materials. The crystalline structure of the powder and doped PMMA nanocomposite samples were determined using X-ray diffraction technique. Scherrer's equation and the FW1/5/4/5M method were used to determine average crystalline size and grain size distributions, respectively. The spectroscopic properties of the powders and doped PMMA nanocomposites were studied by measuring the upconversion emission spectra under near-infrared laser excitation at room temperature. The laser-induced photo thermal behaviors of Er3+:Y2O3 nano-powders and doped PMMA nanocomposite were investigated using the fluorescence intensity ratio (FIR) technique.

Combined control of morphology and polymorph in spray drying of mannitol for dry powder inhalation

NASA Astrophysics Data System (ADS)

Lyu, Feng; Liu, Jing J.; Zhang, Yang; Wang, Xue Z.

2017-06-01

The morphology and polymorphism of mannitol particles were controlled during spray drying with the aim of improving the aerosolization properties of inhalable dry powders. The obtained microparticles were characterized using scanning electron microscopy, infrared spectroscopy, differential scanning calorimetry, powder X-ray diffraction and inhaler testing with a next generation impactor. Mannitol particles of varied α-mannitol content and surface roughness were prepared via spray drying by manipulating the concentration of NH4HCO3 in the feed solution. The bubbles produced by NH4HCO3 led to the formation of spheroid particles with a rough surface. Further, the fine particle fraction was increased by the rough surface of carriers and the high α-mannitol content. Inhalable dry powders with a 29.1 ± 2.4% fine particle fraction were obtained by spray-drying using 5% mannitol (w/v)/2% NH4HCO3 (w/v) as the feed solution, proving that this technique is an effective method to engineer particles for dry powder inhalation.

Mechanochemical synthesis and structural characterization of three novel cocrystals of dimethylglyoxime with N-heterocyclic aromatic compounds and acetamide

NASA Astrophysics Data System (ADS)

Abidi, Syed Sibte Asghar; Azim, Yasser; Gupta, Abhishek Kumar; Pradeep, Chullikkattil P.

2017-12-01

With an aim to explore the interactions of (RR'Cdbnd Nsbnd OH) oxime moiety of dimethylglyoxime (DMG) with pyridyl ring of N-heterocyclic aromatic compounds and acetamide, three novel cocrystals of dimethylglyoxime with acridine (ACR), 1,10-phenanthroline monohydrate (PT) and acetamide (ACT) are reported. These three cocrystals were obtained with a mechanochemical synthesis approach and were characterized by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), fourier transform-infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Additionally, Hirshfeld surface analysis is used to investigate the intermolecular interaction and the crystal packing of cocrystals.

Preparation and antibacterial properties of titanium-doped ZnO from different zinc salts

PubMed Central

2014-01-01

To research the relationship of micro-structures and antibacterial properties of the titanium-doped ZnO powders and probe their antibacterial mechanism, titanium-doped ZnO powders with different shapes and sizes were prepared from different zinc salts by alcohothermal method. The ZnO powders were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED), and the antibacterial activities of titanium-doped ZnO powders on Escherichia coli and Staphylococcus aureus were evaluated. Furthermore, the tested strains were characterized by SEM, and the electrical conductance variation trend of the bacterial suspension was characterized. The results indicate that the morphologies of the powders are different due to preparation from different zinc salts. The XRD results manifest that the samples synthesized from zinc acetate, zinc nitrate, and zinc chloride are zincite ZnO, and the sample synthesized from zinc sulfate is the mixture of ZnO, ZnTiO3, and ZnSO4 · 3Zn (OH)2 crystal. UV-vis spectra show that the absorption edges of the titanium-doped ZnO powders are red shifted to more than 400 nm which are prepared from zinc acetate, zinc nitrate, and zinc chloride. The antibacterial activity of titanium-doped ZnO powders synthesized from zinc chloride is optimal, and its minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) are lower than 0.25 g L−1. Likewise, when the bacteria are treated by ZnO powders synthesized from zinc chloride, the bacterial cells are damaged most seriously, and the electrical conductance increment of bacterial suspension is slightly high. It can be inferred that the antibacterial properties of the titanium-doped ZnO powders are relevant to the microstructure, particle size, and the crystal. The powders can damage the cell walls; thus, the electrolyte is leaked from cells. PMID:24572014

Phase transformations in xerogels of mullite composition

NASA Technical Reports Server (NTRS)

Hyatt, Mark J.; Bansal, Narottam P.

1990-01-01

Monophasic and diphasic xerogels have been prepared as precursors for mullite (3Al203-2Si02). Monophasic xerogel was synthesized from tetraethyl orthosilicate and aluminum nitrate nanohydrate and the diphasic xerogel from colloidal suspension of silica and boehmite. The chemical and structural evolutions, as a function of thermal treatment, in these two types of sol-gel derived mullite precursor powders have been characterized by DTA, TGA, X-ray diffraction, SEM and infrared spectroscopy. Monophasic xerogel transforms to an Al-Si spinel from an amorphous structure at approximately 980 C. The spinel then changes into mullite on further heating. Diphasic xerogel forms mullite at approximately 1360 C. The components of the diphasic powder react independently up to the point of mullite formation. The transformation in the monophasic powder occurs rapidly and yields strongly crystalline mullite with no other phases present. The diphasic powder, however, transforms rather slowly and contains remnants of the starting materials (alpha-Al203, cristobalite) even after heating at high temperatures for long times (1600 C, 6 hr). The diphasic powder could be sintered to high density but not the monophasic powder in spite of its molecular level homogeneity.

A multi-analytical approach for the characterization of powders from the Pompeii archaeological site.

PubMed

Canevali, Carmen; Gentile, Paolo; Orlandi, Marco; Modugno, Francesca; Lucejko, Jeannette Jacqueline; Colombini, Maria Perla; Brambilla, Laura; Goidanich, Sara; Riedo, Chiara; Chiantore, Oscar; Baraldi, Pietro; Baraldi, Cecilia; Gamberini, Maria Cristina

2011-10-01

Nine black powders found in Pompeii houses in three different types of bronze vessels (cylindrical theca atramentaria, unguentaries, and aryballoi) were characterized in order to assess a correspondence between the composition and the type of vessel and, possibly, to verify if these powders were inks or not. For the compositional characterization, a multi-analytical approach was adopted, which involved the use of scanning electron microscopy-energy dispersive X-ray, Fourier-transformed infrared spectroscopy, Raman, X-ray diffraction, electron paramagnetic resonance spectroscopy, thermogravimetric analysis, gas chromatography coupled with mass spectrometry (GC/MS), and pyrolysis GC/MS. Powders contained in cylindrical theca atramentaria form a homogeneous group, and their organic and inorganic compositions suggest that they were writing inks, while powders contained in unguentaries and aryballoi could have had several different uses, including writing inks and cosmetics. Furthermore, the composition profile of the powders found in cylindrical cases shows that, at 79 AD: , in Pompeii, carbon-based inks were still used for writing, and iron gall inks had not been introduced yet.

Synthesis of a Glibenclamide Cocrystal: Full Spectroscopic and Thermal Characterization.

PubMed

Silva Filho, Silvério Ferreira; Pereira, Andreia Cardoso; Sarraguça, Jorge M G; Sarraguça, Mafalda C; Lopes, João; Façanha Filho, Pedro de Freitas; Dos Santos, Adenilson Oliveira; da Silva Ribeiro, Paulo Roberto

2018-06-01

A cocrystal of glibenclamide, an antidiabetic drug classified as type II compound according to the Biopharmaceutics Classification System, has been synthesized using tromethamine as coformer in 1:1 molar ratio, by slow solvent evaporation cocrystalization. The cocrystal obtained was characterized by X-ray powder diffraction, differential scanning calorimetry, Raman, mid infrared, and near-infrared spectroscopy. The results consistently show the formation of a cocrystal between active pharmaceutical ingredients and conformer with the synthons corresponding to hydrogen bonding between hydrogen in amines of tromethamine and carbonyl and sulfonyl groups in glibenclamide. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Optical, electrochemical and thermal properties of Mn2+ doped CdS nanoparticles

NASA Astrophysics Data System (ADS)

Muruganandam, S.; Anbalagan, G.; Murugadoss, G.

2015-08-01

Mn2+ doped (1-5 and 10 %) CdS nanoparticles have been synthesized by the chemical precipitation method using polyvinylpyrrolidone as a capping agent. The particle size, morphology and optical properties have been studied by X-ray powder diffraction, transmission electron microscopy, UV-Visible and photoluminescence spectroscopy. Powder diffraction data have confirmed that the crystallite size is around 2-5 nm. The band gap of the nanoparticles has been calculated using UV-Visible absorption spectra. An optimum concentration, Mn2+ (3 %) has been selected by optical study. The functional groups of the capping agent have been identified by fourier transform infrared spectroscopy study. The presence of dopant (Mn2+) has been confirmed by electron paramagnetic resonance spectroscopy. Thermal properties of CdS:Mn2+ have been analyzed using thermogravimetric-differential thermal analyser. The electrochemical properties of the undoped and doped samples have been studied by cyclic voltammetry for electrode applications. In addition, magnetic properties of Mn2+ doped CdS have been studied using a vibrating sample magnetometer.

Solution combustion method for synthesis of nanostructured hydroxyapatite, fluorapatite and chlorapatite

NASA Astrophysics Data System (ADS)

Zhao, Junjie; Dong, Xiaochen; Bian, Mengmeng; Zhao, Junfeng; Zhang, Yao; Sun, Yue; Chen, JianHua; Wang, XuHong

2014-09-01

Hydroxyapatite (HAP), fluorapatite (Fap) and chlorapatite (Clap) were prepared by solution combustion method with further annealing at 800 °C. The characterization and structural features of the synthesized powders were evaluated by the powder X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and transmission electron microscopy (TEM) techniques. Characterization results from XRD and Rietveld analysis revealed that OH- in the HAP lattice were gradually substituted with the increase of F- and Cl- content and totally substituted at the molar concentration of 0.28 and 0.6, respectively. The results from FI-IR have also confirmed the incorporation of substituted anions in the apatite structure.

Fabrication of PbFe12O19 nanoparticles and study of their structural, magnetic and dielectric properties

NASA Astrophysics Data System (ADS)

Mousavi Ghahfarokhi, S. E.; Rostami, Z. A.; Kazeminezhad, I.

2016-02-01

In this study, M-type Lead hexaferrite (PbFe12O19) nanoparticles were prepared by a sol-gel method and the prepared powders were annealed at 700-1000 °C for 1, 1.5, 2, 2.5 and 3 h. The Lead hexaferrite powders were characterized using thermogravimetry-differential thermal analysis, X-ray diffraction, scanning electron microscopy, LCR meter, vibrating sample magnetometer, and Fourier transforms infrared spectroscopy. The size of the nanoparticles was increased with the annealing temparature. The results reveal that the best annealing temperature and annealing time for preparing PbFe12O19 nanoparticles at 800 °C and 3 h are obtained. The infrared spectra measured in range of 4000-400 cm-1 exhibit stretching modes of metal ions in tetrahedral site at 580-550 cm-1 and octahedral site at 470-430 cm-1. The variation in ac conductivity (σac) with frequency shows that the electrical conductivity in these ferrites is mainly attributed to the electron hopping mechanism.

High throughput screening of ligand binding to macromolecules using high resolution powder diffraction

DOEpatents

Von Dreele, Robert B.; D'Amico, Kevin

2006-10-31

A process is provided for the high throughput screening of binding of ligands to macromolecules using high resolution powder diffraction data including producing a first sample slurry of a selected polycrystalline macromolecule material and a solvent, producing a second sample slurry of a selected polycrystalline macromolecule material, one or more ligands and the solvent, obtaining a high resolution powder diffraction pattern on each of said first sample slurry and the second sample slurry, and, comparing the high resolution powder diffraction pattern of the first sample slurry and the high resolution powder diffraction pattern of the second sample slurry whereby a difference in the high resolution powder diffraction patterns of the first sample slurry and the second sample slurry provides a positive indication for the formation of a complex between the selected polycrystalline macromolecule material and at least one of the one or more ligands.

Symposium U: Thermoelectric Power Generation. Held in Boston, Massachusetts on November 26-29, 2007

DTIC Science & Technology

2008-04-01

including X - ray /electron diffraction, TGA analysis, Raman / Fourier Transform Infrared Spectroscopy, electron microscopy, Rutherford back-scattering and...Energy dispersive X - ray analysis were performed on the treated sample. The results revealed that a surface layer (from 10 nm to up to micron in...nanoparticles into a matrix of bulk Bi2Te 3 material via a hot pressing process. These nanocomposites have been examined by SEM and X - ray powder

Evaluation of photostability of solid-state nicardipine hydrochloride polymorphs by using Fourier-transformed reflection-absorption infrared spectroscopy - effect of grinding on the photostability of crystal form.

PubMed

Teraoka, Reiko; Otsuka, Makoto; Matsuda, Yoshihisa

2004-11-22

Photostability and physicochemical properties of nicardipine hydrochloride polymorphs (alpha- and beta-form) were studied by using Fourier-transformed reflection-absorption infrared spectroscopy (FT-IR-RAS) of the tablets, X-ray powder diffraction analysis, differential scanning calorimetry (DSC), and color difference measurement. It was clear from the results of FT-IR-RAS spectra after irradiation that nicardipine hydrochloride in the solid state decomposed to its pyridine derivative when exposed to light. The photostability of the ground samples of two forms was also measured in the same manner. The two crystalline forms of the drug changed to nearly amorphous form after 150 min grinding in a mixer mill. X-ray powder diffraction patterns of those ground samples showed almost halo patterns. The nicardipine hydrochloride content on the surface of the tablet was determined based on the absorbance at 1700 cm(-1) attributable to the C=O stretch vibration in FT-IR-RAS spectra before and after irradiation by fluorescent lamp (3500 lx). The photodegradation followed apparently the first-order kinetics for any sample. The apparent photodegradation rate constant of beta-form was greater than that of alpha-form. The ground samples decomposed rapidly under the same light irradiation as compared with the intact crystalline forms. The photodegradation rate constant decreased with increase of the heat of fusion. copyright 2004 Elsevier B.V.

Powder X-ray diffraction, infrared and 13C NMR spectroscopic studies of the homologous series of some solid-state zinc(II) and sodium(I) n-alkanoates

NASA Astrophysics Data System (ADS)

Nelson, Peter N.; Taylor, Richard A.

2015-03-01

A comparative study of the room temperature molecular packing and lattice structures for the homologous series of zinc(II) and sodium(I) n-alkanoates adduced from Fourier transform infrared and solid-state 13C NMR spectroscopic data in conjunction with X-ray powder diffraction measurements is carried out. For zinc carboxylates, metal-carboxyl bonding is via asymmetric bridging bidentate coordination whilst for the sodium adducts, coordination is via asymmetric chelating bidentate bonding. All compounds are packed in a monoclinic crystal system. Furthermore, the fully extended all-trans hydrocarbon chains are arranged as lamellar bilayers. For zinc compounds, there is bilayer overlap, for long chain adducts (nc > 8) but not for sodium compounds where methyl groups from opposing layers in the lamellar are only closely packed. Additionally, the hydrocarbon chains are extended along the a-axis of the unit cell for zinc compounds whilst for sodium carboxylates they are extended along the c-axis. These packing differences are responsible for different levels of Van der Waals effects in the lattices of these two series of compounds, hence, observed odd-even alternation is different. The significant difference in lattice packing observed for these two series of compounds is proposed to be due to the difference in metal-carboxyl coordination mode, arising from the different electronic structure of the central metal ions.

Synthesis, growth, structural, optical, spectral, thermal and mechanical studies of 4-methoxy 4-nitrostilbene (MONS): a new organic nonlinear optical single crystal.

PubMed

Dinakaran, Paul M; Bhagavannarayana, G; Kalainathan, S

2012-11-01

4-Methoxy 4-nitrostilbene (MONS), a new organic nonlinear optical material has been synthesized. Based on the solubility data good quality single crystal with dimensions up to 38×11×3 mm(3) has been grown by slow evaporation method using ethyl methyl ketone (MEK) as a solvent. Powder XRD confirms the crystalline property and also the diffraction planes have been indexed. The lattice parameters for the grown MONS crystals were determined by using single crystal X-ray diffraction analysis and it reveals that the crystal lattice system is triclinic. The crystalline perfection of the grown crystals has been analysed by high resolution X-ray diffraction (HRXRD) rocking curve measurements. Fourier transform infrared (FTIR) spectrum for powdered MONS sample confirms the functional groups present in the grown crystal. The UV-vis absorption spectrum has been recorded in the range of 190-1100 nm and the cut off wavelength 499 nm has been determined. The optical constants of MONS have been determined through UV-vis-NIR spectroscopy. The MONS crystals were further subjected to other characterizations. i.e., (1)H NMR, TG/DTA, photoluminescence and microhardness test. The Kurtz and Perry powder technique confirms the NLO property of the grown crystal and the SHG efficiency of MONS was found to be 1.55× greater than that of KDP crystal. Copyright © 2012 Elsevier B.V. All rights reserved.

[Infrared spectroscopy and XRD studies of coral fossils].

PubMed

Chen, Quan-li; Zhou, Guan-min; Yin, Zuo-wei

2012-08-01

Coral fossil is an old remain of multicellular animal on the earth, and formed by various geological processes. The structural characteristics and compositions of the coral fossils with different color and radial texture on the surface were studied by infrared absorption spectroscopy and X-ray powder diffraction analyses. The results show that the studied coral fossils mainly are composed of SiO2, and the radial microstructure characterized by the calcareous coral cross-section is preserved. It is formed by metasomatism by SiO2. The infrared absorption spectra of the coral fossil with different color and texture are essentially the same, showing typical infrared absorption spectra of the quartz jade. XRD analysis shows that the main components of the coral fossils with different color and texture are consistent and mainly composed of SiO2 with a trace amount of other minerals and without CaCO3.

XRD, SEM and infrared study into the intercalation of sodium hexadecyl sulfate (SHS) into hydrocalumite.

PubMed

Zhang, Ping; Wang, Tianqi; Zhang, Longlong; Wu, Daishe; Frost, Ray L

2015-12-05

Hydrocalumite (CaAl-LDH-Cl) interacted with a natural anionic surfactant, sodium hexadecyl sulfate (SHS), was performed using an intercalation method. To understand the intercalation behavior and characterize the resulting products, powder X-ray diffraction (XRD), scan electron microscopy (SEM) and mid-infrared (MIR) spectroscopy combined with near-infrared (NIR) spectroscopy technique were used. The XRD analysis indicated that SHS was intercalated into CaAl-LDH-Cl successfully, resulting in an expansion of the interlayer (from 0.78 nm to 2.74 nm). The bands of C-H stretching vibrations of SHS were observed in the near-infrared spectra, which indicated that the resulting products were indeed CaAl-LDH-SHS. In addition, the bands of water stretching vibrations and OH groups shifted to higher wavenumbers when SHS was intercalated into CaAl-LDH-Cl interlayer space. Copyright © 2015 Elsevier B.V. All rights reserved.

[Does carbonate originate from carbonate-calcium crystal component of the human urinary calculus?].

PubMed

Yuzawa, Masayuki; Nakano, Kazuhiko; Kumamaru, Takatoshi; Nukui, Akinori; Ikeda, Hitoshi; Suzuki, Kazumi; Kobayashi, Minoru; Sugaya, Yasuhiro; Morita, Tatsuo

2008-09-01

It gives important information in selecting the appropriate treatment for urolithiasis to confirm the component of urinary calculus. Presently component analysis of the urinary calculus is generally performed by infrared spectroscopy which is employed by companies providing laboratory testing services in Japan. The infrared spectroscopy determines the molecular components from the absorption spectra in consequence of atomic vibrations. It has the drawback that an accurate crystal structure cannot be analyzed compared with the X-ray diffraction method which analyzes the crystal constituent based on the diffraction of X-rays on crystal lattice. The components of the urinary calculus including carbonate are carbonate apatite and calcium carbonate such as calcite. Although the latter is reported to be very rare component in human urinary calculus, the results by infrared spectroscopy often show that calcium carbonate is included in calculus. The infrared spectroscopy can confirm the existence of carbonate but cannot determine whether carbonate is originated from carbonate apatite or calcium carbonate. Thus, it is not clear whether calcium carbonate is included in human urinary calculus component in Japan. In this study, we examined human urinary calculus including carbonate by use of X-ray structural analysis in order to elucidate the origin of carbonate in human urinary calculus. We examined 17 human calculi which were reported to contain calcium carbonate by infrared spectroscopy performed in the clinical laboratory. Fifteen calculi were obtained from urinary tract, and two were from gall bladder. The stones were analyzed by X-ray powder method after crushed finely. The reports from the clinical laboratory showed that all urinary culculi consisted of calcium carbonate and calcium phosphate, while the gallstones consisted of calcium carbonate. But the components of all urinary calculi were revealed to be carbonate apatite by X-ray diffraction. The components of gallstones were shown to be calcium carbonate (one calcite and the other aragonite) not only by infrared spectroscopy but by X-ray diffraction. It was shown that component analysis of the calculus could be more accurately performed by adding X-ray diffraction method to infrared spectroscopy. It was shown that calcium carbonate existed in a gallstone. As for the carbonate in human urinary calculi, present study showed that it was not calcium carbonate origin but carbonate apatite origin.

Synthesis of nano-titanium dioxide by sol-gel route

NASA Astrophysics Data System (ADS)

Kaler, Vandana; Duchaniya, R. K.; Pandel, U.

2016-04-01

Nanosized titanium dioxide powder was synthesised via sol-gel route by hydrolysis of titanium tetraisopropoxide with ethanol and water mixture in high acidic medium. The synthesized nanopowder was further characterized by X-ray Diffraction, Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and Ultraviolet Visible Spectroscopy in order to determine size, morphology and crystalline structure of the material. The synthesis of nano-TiO2 powder in anatase phase was realized by XRD. The optical studies of nano-TiO2 powder was carried out by UV-Vis spectroscopy and band gap was calculated as 3.5eV, The SEM results with EDAX confirmed that prepared nano-TiO2 particles were in nanometer range with irregular morphology. The FTIR analysis showed that only desired functional groups were present in sample. These nano-TiO2 particles have applications in solar cells, chemical sensors and paints, which are thrust areas these days.

Rietveld analysis using powder diffraction data with anomalous scattering effect obtained by focused beam flat sample method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, Masahiko, E-mail: masahiko@spring8.or.jp; Katsuya, Yoshio, E-mail: katsuya@spring8.or.jp; Sakata, Osami, E-mail: SAKATA.Osami@nims.go.jp

2016-07-27

Focused-beam flat-sample method (FFM) is a new trial for synchrotron powder diffraction method, which is a combination of beam focusing optics, flat shape powder sample and area detectors. The method has advantages for X-ray diffraction experiments applying anomalous scattering effect (anomalous diffraction), because of 1. Absorption correction without approximation, 2. High intensity X-rays of focused incident beams and high signal noise ratio of diffracted X-rays 3. Rapid data collection with area detectors. We applied the FFM to anomalous diffraction experiments and collected synchrotron X-ray powder diffraction data of CoFe{sub 2}O{sub 4} (inverse spinel structure) using X-rays near Fe K absorptionmore » edge, which can distinguish Co and Fe by anomalous scattering effect. We conducted Rietveld analyses with the obtained powder diffraction data and successfully determined the distribution of Co and Fe ions in CoFe{sub 2}O{sub 4} crystal structure.« less

Synthesis and characterization of polyurethane/CdS-SiO 2 nanocomposites via ultrasonic process

NASA Astrophysics Data System (ADS)

Chen, Jing; Zhou, Yu-Ming; Nan, Qiu-Li; Ye, Xiao-Yun; Sun, Yan-Qing; Wang, Zhi-Qiang; Zhang, Shi-Ming

2008-12-01

In this study, the high-intensity ultrasound was applied in the preparation of chiral polyurethane/CdS-SiO 2 nanocomposites. The polyurethane/CdS-SiO 2 nanocomposites were analyzed by powder X-ray diffraction, thermogravimetric analysis (TGA), TEM and SEM. The results indicated that the heat stability of the nanocomposites was improved in the presence of CdS-SiO 2 core-shell nanoparticles. The infrared emissivity (8-14 μm) study revealed that the nanocomposites possessed much lower infrared values compared with those of the neat polymers and nanoparticles, respectively. A possible mechanism of ultrasonic induced composite reaction was proposed based on the experimental results.

Effect of processing route for preparation of mullite from kaolinite and alumina

NASA Astrophysics Data System (ADS)

Behera, Pallavi Suhasinee; Bhattacharyya, Sunipa

2018-05-01

In current work, two different types of mullite ceramic powder were prepared using kaolinite and alumina by solid state and chemical precipitation route. The phases, bond types and microstructural evolution of the mullite powders were investigated by X-ray diffraction, infrared analysis, and field emission scanning electron microscopy to study the mullitisation behavior. The solid state method evident a pure mullite phase formation at 1550 °C. In case of chemical precipitation route small amount of alumina peak was noticed along with major phase of mullite which was also clearly apprehended from FESEM micrographs and IR spectra. Densification was more for the samples prepared by solid state process which may be correlated to the delayed mullitization process in chemical precipitation route.

Impact of physical and chemical parameters on the hydroxyapatite nanopowder synthesized by chemical precipitation method

NASA Astrophysics Data System (ADS)

Thu Trang Pham, Thi; Phuong Nguyen, Thu; Pham, Thi Nam; Phuong Vu, Thi; Tran, Dai Lam; Thai, Hoang; Thanh Dinh, Thi Mai

2013-09-01

In this paper, the synthesis of hydroxyapatite (HAp) nanopowder was studied by chemical precipitation method at different values of reaction temperature, settling time, Ca/P ratio, calcination temperature, (NH4)2HPO4 addition rate, initial concentration of Ca(NO3)2 and (NH4)2HPO4. Analysis results of properties, morphology, structure of HAp powder from infrared (IR) spectra, x-ray diffraction (XRD), energy dispersive x-ray (EDX) spectra and scanning electron microscopy (SEM) indicated that the synthesized HAp powder had cylinder crystal shape with size less than 100 nm, single-phase structure. The variation of the synthesis conditions did not affect the morphology but affected the size of HAp crystals.

Second harmonic generation and crystal growth of new chalcone derivatives

NASA Astrophysics Data System (ADS)

Patil, P. S.; Dharmaprakash, S. M.; Ramakrishna, K.; Fun, Hoong-Kun; Sai Santosh Kumar, R.; Narayana Rao, D.

2007-05-01

We report on the synthesis, crystal structure and optical characterization of chalcone derivatives developed for second-order nonlinear optics. The investigation of a series of five chalcone derivatives with the second harmonic generation powder test according to Kurtz and Perry revealed that these chalcones show efficient second-order nonlinear activity. Among them, high-quality single crystals of 3-Br-4'-methoxychalcone (3BMC) were grown by solvent evaporation solution growth technique. Grown crystals were characterized by X-ray powder diffraction (XRD), laser damage threshold, UV-vis-NIR and refractive index measurement studies. Infrared spectroscopy, thermogravimetric analysis and differential thermal analysis measurements were performed to study the molecular vibration and thermal behavior of 3BMC crystal. Thermal analysis does not show any structural phase transition.

Effect of Gallium and Indium Co-Substituting on Upconversion Properties of Er/Yb:Yttrium Aluminum Garnet Powders Prepared by the Co-Precipitation Method.

PubMed

Zhang, Wei; Liang, Yun-Ling; Hu, Zheng-Fa; Feng, Zu-Yong; Lun, Ma; Zhang, Xiu-ping; Sheng, Xia; Liu, Qian; Luo, Jie

2016-04-01

Gallium and Indium co-substituted Yb, Er:YAG was fabricated through the chemical co-precipitation method. The formation process and structure of the Ga3+ and In3+ substituted phosphor powders were characterized by the X-ray diffraction, thermo-gravimetry analyzer, infrared spectra, and X-ray photoelectron spectroscopy, and the effects of Ga3+ and In3+ concentration on the luminescence properties were investigated by spectrum. The results showed that the blue shift occurred after the substitution of Ga3+ and In3+ for Al3+ in matrix, and the intensity of emission spectrum was affected by the concentration of Ga3+ and In3+.

Plasma induced sp 2 to sp 3 transition in boron nitride

NASA Astrophysics Data System (ADS)

Zhang, J.; Cui, Q.; Li, X.; He, Z.; Li, W.; Ma, Y.; Guan, Q.; Gao, W.; Zou, G.

2004-12-01

The transition from sp 2 to sp 3 hybridization in boron nitride has been induced in plasma. Nano-crystals of cubic boron nitride (cBN) have been synthesized by direct current arc discharge method using hexagonal boron nitride (hBN) as the starting material. The characterization of the as-grown powders is carried out by X-ray diffraction, Fourier transform infrared spectroscopy and transmission electron microscopy. It has been shown that cBN and hBN grains with 20-60 nm in size co-exist in the powders. A reaction route of sublimation - re-hybridization - crystallization had been put forward to explain the mechanism of the hybridization transition and the growth of cBN by this method.

Phase transformations in xerogels of mullite composition

NASA Technical Reports Server (NTRS)

Hyatt, Mark J.; Bansal, Narottam P.

1988-01-01

Monophasic and diphasic xerogels have been prepared as precursors for mullite (3Al2O3-2SiO2). Monophasic xerogel was synthesized from tetraethyl orthosilicate and aluminum nitrate nanohydrate and the diphasic xerogel from colloidal suspension of silica and boehmite. The chemical and structural evolutions, as a function of thermal treatment, in these two types of sol-gel derived mullite precursor powders have been characterized by DTA, TGA, X-ray diffraction, SEM and infrared spectroscopy. Monophasic xerogel transforms to an Al-Si spinel from an amorphous structure at approximately 980 C. The spinel then changes into mullite on further heating. Diphasic xerogel forms mullite at approximately 1360 C. The components of the diphasic powder react independently up to the point of mullite formation. The transformation in the monophasic powder occurs rapidly and yields strongly crystalline mullite with no other phases present. The diphasic powder, however, transforms rather slowly and contains remnants of the starting materials (alpha-Al2O3, cristobalite) even after heating at high temperatures for long times (1600 C, 6 hr). The diphasic powder could be sintered to high density but not the monophasic powder in spite of its molecular level homogeneity.

New Phases of YBaCuGeO Superconductors Identified from X-ray Diffraction and Infra-red Absorption Measurements

NASA Astrophysics Data System (ADS)

Abo-Arais, Ahmed; Dawoud, Mohamad Ahmad Taher

2005-01-01

X-ray powder diffraction patterns and infra-red absorption spectra have been evaluated and analysed for the Y1 Ba2 Cu3 O7-d - Gex compound samples prepared by the solid state reaction with x values ranging from 0.0 to 1.13. All samples show bulk superconductivity above liquid nitrogen temperature using the levitation test (Meissner effect). Samples with Ge content up to x = 0.2 have offset Tc between 83K and 92K while the sample with x = 1.13 shows semiconducting behavior above 100K. As a result of the solid state interaction between YBCO and Ge, new phases are observed and determined, mainly three phases are concluded from X-ray powder diffraction analysis: (i) Ba2GeO4 (ii) Y2BaCuO5 (iii) BaCO3. The unit cell parameters a, b and c of the orthorhombic superconducting phase are calculated for all the prepared samples. The anisotropy factor is evaluated and related to the new structural phases in YBCO-Ge composite system. The I-R absorption spectra for the samples with orthorhombic symmetry have been determined. The phonon modes between ~ 400 cm-1 and 630 cm-1 are attributed to the Cu - O octahedron and pyramid vibrations for the CuO2 -planes and CuO-chains, while the peaks in the range from ~ 700 cm-1 to ~ 860 cm-1 may be due to defects such as the new phase Ba2GeO4 and the green phase Y2BaCuO5. The obtained results are discussed according to the superconductor - semi-conductor composite model and with the phonon-mediated charge transfer between CuO2 -planes and CuO- chains through apex oxygen (BaO).

Nanoscale contact resistance of V2O5 xerogel films developed by nanostructured powder

NASA Astrophysics Data System (ADS)

Bera, Biswajit; Sekhar Das, Pradip; Bhattacharya, Manjima; Ghosh, Swapankumar; Mukhopadhyay, Anoop Kumar; Dey, Arjun

2016-03-01

Here we report the synthesis of V2O5 nanostructures by a fast, simple, cost-effective, low-temperature chemical process; followed by the deposition of V2O5 xerogel thin films on a glass substrate by a sol-gel route. Phase analysis, phase transition, microstructural and electronic characterization studies are carried out by x-ray diffraction, texture coefficient analysis, field emission scanning electron microscopy, transmission electron microscopy (TEM), related selected area electron diffraction pattern (SAED) analysis, Fourier transform infrared spectroscopy, thermogravimetry and differential thermal analysis, differential scanning calorimetry, and x-ray photoelectron spectroscopy techniques. Confirmatory TEM and SAED data analysis prove further that in this polycrystalline powder there is a unique localized existence of purely single crystalline V2O5 powder with a preferred orientation in the (0 1 0) direction. The most interesting result obtained in the present work is that the xerogel thin films exhibit an inherent capability to enhance the intrinsic resistance against contact induced deformations as more external load is applied during the nanoindentation experiments. In addition, both the nanohardness and Young’s modulus of the films are found to be insensitive to load variations (e.g. 1 to 7 mN). These results are explained in terms of microstructural parameters, e.g. porosity and structural configuration.

Effect of aging temperature on formation of sol-gel derived fluor-hydroxyapatite nanoparticles.

PubMed

Joughehdoust, S; Behnamghader, A; Jahandideh, R; Manafi, S

2010-04-01

Synthetic hydroxyapatite (HA) has been recognized as one of the most important bone substitute materials in orthopaedics and dentistry over past few decades because of its chemical and biological similarity to the mineral phase of human bone. One solution for reduction the solubility of HA in biological environments is replacing F- by OH in HA structure and forming fluor-hydroxyapatite (FHA) solid solution. In this paper, FHA nanoparticles were successfully synthesized by a sol-gel method. Also, the influence of aging temperature on formation of FHA powder was studied. Equimolar solutions of calcium nitrate tetrahydrate, triethyl phosphite and ammonium fluoride in ethanol were used as Ca, P and F precursors. After aging at different temperatures, the synthesized powders were heat treated at 550 degrees C. The powders were investigated with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), selected area electron diffraction pattern (SAED), energy dispersive analysis of X-ray (EDAX) and zetasizer measurement. The results of XRD proved the presence of fluorapatite (FA) and HA in all samples. In addition, the formation of FHA was confirmed by FT-IR results. XRD studies also showed that the crystallites were in nanometric scale. At the same time, this result was in good agreement with the result of zetasizer analysis.

Synthesis and characterization of some metal oxide nanocrystals by microwave irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rashad, M.; Gaber, A.; Abdelrahim, M. A.

2013-12-16

Copper oxide and cobalt oxide (CuO, Co3O4) nanocrystals (NCs) have been successfully prepared in a short time using microwave irradiation. The resulted powders of nanocrystals (NCs) were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thermogravimetric analysis (TGA) measurements are also studied. Fourier-transform infrared (FT-IR) and UV–visible absorption spectroscopy of both kind of nanoparticels are illustrated. Optical absorption analysis indicated the direct band gap for both kinds of nanocrystals.

Synthesis of samarium doped gadolinium oxide nanorods, its spectroscopic and physical properties

NASA Astrophysics Data System (ADS)

Boopathi, G.; Gokul Raj, S.; Ramesh Kumar, G.; Mohan, R.; Mohan, S.

2018-06-01

One-dimensional samarium doped gadolinium oxide [Sm:Gd2O3] nanorods have been synthesized successfully through co-precipitation technique in aqueous solution. The as-synthesized and calcined products were characterized by using powder X-ray diffraction pattern, Fourier transform Raman spectroscopy, thermogravimetric/differential thermal analysis, scanning electron microscopy with energy-dispersive X-ray analysis, transmission electron microscopy, Fourier transform infrared spectroscopy, Ultraviolet-Visible spectrometry, photoluminescence spectrophotometer and X-ray photoelectron spectroscopy techniques. The obtained results are discussed in detailed manner.

DEVELOPMENT OF LiCo0.90Mg0.05Al0.05O2 THIN FILMS BY PULSED LASER DEPOSITION TECHNIQUE

NASA Astrophysics Data System (ADS)

Vasanthi, R.; Ruthmangani, I.; Manoravi, P.; Joseph, M.; Kesavamoorthy, R.; Sundar, C.; Selladurai, S.

LiCo0.90Mg0.05Al0.05O2 bulk powders are synthesized using combustion process and made into a thin film by depositing on silicon wafer using a pulsed laser ablation technique. A comparative study by SEM (Scanning Electron Microscope) XRD (X-ray diffraction), Infrared spectroscopy and Raman Spectroscopy is performed on both bulk and PLD thin films.

Growth, structural, spectral, mechanical, thermal and dielectric characterization of phosphoric acid admixtured L-alanine (PLA) single crystals.

PubMed

Rose, A S J Lucia; Selvarajan, P; Perumal, S

2011-10-15

Phosphoric acid admixtured L-alanine (PLA) single crystals were grown successfully by solution method with slow evaporation technique at room temperature. Crystals of size 18 mm×12 mm×8 mm have been obtained in 28 days. The grown crystals were colorless and transparent. The solubility of the grown samples has been found out at various temperatures. The lattice parameters of the grown crystals were determined by X-ray diffraction technique. The reflection planes of the sample were confirmed by the powder X-ray diffraction study and diffraction peaks were indexed. Fourier transform infrared (FTIR) studies were used to confirm the presence of various functional groups in the crystals. UV-visible transmittance spectrum was recorded to study the optical transparency of grown crystal. The nonlinear optical (NLO) property of the grown crystal was confirmed by Kurtz-Perry powder technique and a study of its second harmonic generation efficiency in comparison with potassium dihydrogen phosphate (KDP) has been made. The mechanical strength of the crystal was estimated by Vickers hardness test. The grown crystals were subjected to thermo gravimetric and differential thermal analysis (TG/DTA). The dielectric behavior of the sample was also studied. Copyright © 2011 Elsevier B.V. All rights reserved.

A Novel Coordination Polymer Based on Trinuclear Cobalt Building Blocks Cluster: Synthesis, Crystal Structure, and Properties

NASA Astrophysics Data System (ADS)

Lu, J. F.; Tang, Z. H.; Shi, J.; Ge, H. G.; Jiang, M.; Song, J.; Jin, L. X.

2017-12-01

The title compound {[Co3(μ3-OH)(μ2-H2O)2(H2O)5(BTC)2] · 6H2O} n (H3BTC is a 1,3,5-benzenetricarboxylic acid) was prepared and characterized by single crystal and powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric and elemental analyses. The single crystal X-ray diffraction reveals that the title compound consists of 1D infinite zigzag chains which were constructed by trinuclear cobalt cluster and BTC3- ligand. Neighbouring above-mentioned 1D infinite zigzag chains are further linked by intermolecular hydrogen bonding to form a 3D supermolecular structure. In addition, the luminescent properties of the title compound were investigated.

Absence of bacterial imprints on struvite-containing kidney stones: a structural investigation at the mesoscopic and atomic scale.

PubMed

Bazin, Dominique; André, Gilles; Weil, Raphael; Matzen, Guy; Emmanuel, Veron; Carpentier, Xavier; Daudon, M

2012-04-01

Bacterial imprints are always observed on highly carbonated apatite kidney stones but not struvite kidney stones. Struvite and carbonated apatite stones with a high CO(3)(2-)/PO(4)(3-) rate are believed to develop from infections, but their structural differences at the mesoscopic scale lack explanation. We investigated 17 urinary calculi composed mainly of struvite or carbonated apatite by Fourier transform infrared, scanning electron microscopy, and powder neutron diffraction techniques. Carbonated apatite but not struvite stones showed bacterial imprints. If the same stone contained both carbonated apatite and struvite components, bacterial imprints were observed on the carbonated apatite but not the struvite part. Moreover, neutron powder diffraction experiments revealed the crystal size of struvite stones were larger than that of carbonated apatite stones (250 ± 50 vs 50 nm). Bacterial imprints may appear more easily on kidney stones with small nanocrystals, such as carbonated apatite than with large nanocrystals, such as struvite. This approach may help identify bacteria contributing to stone formation, perhaps with negative results of urine culture. Copyright © 2012 Elsevier Inc. All rights reserved.

Optical, Magnetic and Photocatalytic Activity Studies of Li, Mg and Sr Doped and Undoped Zinc Oxide Nanoparticles.

PubMed

Shanthi, S I; Poovaragan, S; Arularasu, M V; Nithya, S; Sundaram, R; Magdalane, C Maria; Kaviyarasu, K; Maaza, M

2018-08-01

Nanoparticles of Li, Mg and Sr doped and undoped zinc oxide was prepared by simple precipitation method. The structural, optical, and magnetic properties of the samples were investigated by the Powder X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Fourier Transform Infrared (FTIR) spectroscopy, Ultra-violet Visible spectroscopy (UV-vis) spectra, Photoluminescence (PL) and Vibrational Sample Magnetometer (VSM). The Powder X-ray diffraction data confirm the formation of hexagonal wurtzite structure of all doped and undoped ZnO. The SEM photograph reveals that the pores availability and particles size in the range of 10 nm-50 nm. FTIR and UV-Visible spectra results confirm the incorporation of the dopant into the ZnO lattice nanostructure. The UV-Visible spectra indicate that the shift of blue region (lower wavelength) due to bandgap widening. Photoluminescence intensity varies with doping due to the increase of oxygen vacancies in prepared ZnO. The pure ZnO exist paramagnetic while doped (Li, Mg and Sr) ZnO exist ferromagnetic property. The photocatalytic activity of the prepared sample also carried out in detail.

Synthesis and characterization of nanocrystalline Nd{sup 3+}-doped gadolinium scandium aluminum garnet powders by a gel-combustion method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Jing, E-mail: zlj007@126.com; Miao, Ju-hong; Xu, Lin-hua

2012-07-15

Graphical abstract: The graph shows the emission spectra (λ{sub ex} = 808 nm) of 1 at.% Nd:GSAG powders sintered at different temperatures for 3 h. Compared with the powder sintered at 900 °C, the PL intensity of the powder sintered at 1000 °C decreased significantly. The changes in the PL intensity should mainly due to the crystallinity and dispersion of the powders. Highlights: ► We synthesized Nd:GSAG nano-powders by gel-combustion method successfully. ► We analyzed the structure and the morphology of the heat-treated products. ► We studied the optical characteristics of Nd:GSAG nano-powders. -- Abstract: Nd{sup 3+}-doped gadolinium scandium aluminummore » garnet (Nd:GSAG) precursor was synthesized by a gel combustion method using metal nitrates and citric acid as raw materials. The structure and morphology of the precursor and the sintered powders were studied by means of X-ray diffraction (XRD), infrared spectroscopy (IR) and transmission electron microscopy (TEM). The results showed that the precursor transformed into pure GSAG polycrystalline phase at about 800 °C, and the powders sintered at 800–1000 °C were well-dispersed with average particle sizes in the range of 30–80 nm. Optical properties of Nd:GSAG nano-powders were characterized by using photoluminescence spectroscopy. The highest photoluminescence intensity was achieved for the powder sintered at 900 °C.« less

The Powder Diffraction File: Past, Present, and Future

PubMed Central

Smith, Deane K.; Jenkins, Ron

1996-01-01

The Powder Diffraction file has been the primary reference for Powder Diffraction Data for more than half a century. The file is a collection of about 65 000 reduced powder patterns stored as sets of d/I data along with the appropriate crystallographic, physical and experimental information. This paper reviews the development and growth of the PDF and discusses the role of the ICDD in the maintenance and dissemination of the file. PMID:27805163

Solid state characterization and crystal structure from X-ray powder diffraction of two polymorphic forms of ranitidine base.

PubMed

de Armas, Héctor Novoa; Peeters, Oswald M; Blaton, Norbert; Van Gyseghem, Elke; Martens, Johan; Van Haele, Gerrit; Van Den Mooter, Guy

2009-01-01

Ranitidine hydrochloride (RAN-HCl), a known anti-ulcer drug, is the product of reaction between HCl and ranitidine base (RAN-B). RAN-HCl has been extensively studied; however this is not the case of the RAN-B. The solid state characterization of RAN-B polymorphs has been carried out using different analytical techniques (microscopy, thermal analysis, Fourier transform infrared spectrometry in the attenuated total reflection mode, (13)C-CPMAS-NMR spectroscopy and X-ray powder diffraction). The crystal structures of RAN-B form I and form II have been determined using conventional X-ray powder diffraction in combination with simulated annealing and whole profile pattern matching, and refined using rigid-body Rietveld refinement. RAN-B form I is a monoclinic polymorph with cell parameters: a = 7.317(2), b = 9.021(2), c = 25.098(6) A, beta = 95.690(1) degrees and space group P2(1)/c. The form II is orthorhombic: a = 31.252(4), b = 13.052(2), c = 8.0892(11) A with space group Pbca. In RAN-B polymorphs, the nitro group is involved in a strong intramolecular hydrogen bond responsible for the existence of a Z configuration in the enamine portion of the molecules. A tail to tail packing motif can be denoted via intermolecular hydrogen bonds. The crystal structures of RAN-B forms are compared to those of RAN-HCl polymorphs. RAN-B polymorphs are monotropic polymorphic pairs. (c) 2008 Wiley-Liss, Inc. and the American Pharmacists Association

Determination of cellulose crystallinity from powder diffraction diagrams: Powder Diffraction Diagrams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindner, Benjamin; Petridis, Loukas; Langan, Paul

2014-10-01

Commonly one-dimensional (1D) (spherically averaged) powder diffraction diagrams are used to determine the degree of cellulose crystallinity in biomass samples. Here, it is shown using molecular modeling how disorder in cellulose fibrils can lead to considerable uncertainty in conclusions drawn concerning crystallinity based on 1D powder diffraction data alone. For example, cellulose microfibrils that contain both crystalline and noncrystalline segments can lead to powder diffraction diagrams lacking identifiable peaks, while microfibrils without any crystalline segments can lead to such peaks. Moreover, this leads to false positives, that is, assigning disordered cellulose as crystalline, and false negatives, that is, categorizing fibrilsmore » with crystalline segments as amorphous. Finally, the reliable determination of the fraction of crystallinity in any given biomass sample will require a more sophisticated approach combining detailed experiment and simulation.« less

High-pressure polymorphism of the electrochemically active organic molecule tetrahydroxy-p-benzoquinone

DOE PAGES

Ciezak-Jenkins, Jennifer A.

2016-04-22

We have studied the structural and chemical response of tetrahydroxy-p-benzoquinone to isothermal compression to near 20 GPa using powder x-ray diffraction and vibrational spectroscopy. Compression beyond 11.5 GPa resulted in the appearance of several new peaks in the x-ray patterns, changes in the peak distribution and intensities, as well as the disappearance of features observed at lower pressures, which when coupled with concomitant changes in the infrared spectrum are indicative of a phase transition. Further analysis of the infrared spectra suggest this phase transition results in an increase in the anharmonicity of the system. Finally, Raman spectroscopic experiments indicate themore » high-pressure phase to be highly photosensitive and easily polymerized.« less

Photoluminescent spectroscopy measurements in nanocrystalline praseodymium doped zirconia powders

NASA Astrophysics Data System (ADS)

Ramos-Brito, F.; Murrieta S, H.; Hernández A, J.; Camarillo, E.; García-Hipólito, M.; Martínez-Martínez, R.; Álvarez-Fragoso, O.; Falcony, C.

2006-05-01

Praseodymium doped zirconia powder (ZrO2: (0.53 at%) Pr3+) was prepared by a co-precipitation technique and annealed in air at a temperature Ta = 950 °C. The x-ray diffraction pattern shows a nanocrystalline structure composed of 29.6% monoclinic and 70.4% cubic-tetragonal phases. Medium infrared and Raman analysis confirms the monoclinic/cubic-tetragonal crystalline structure and proves the absence of praseodymium aggregates in the material. Photoluminescent spectroscopy over excitations of 457.9 and 514.9 nm (at 20 K), shows two emission spectra composed of many narrow peaks in the visible-near infrared region (VIS-NIR) of the electromagnetic spectrum, associated with 4f inter-level electronic transitions in praseodymium ions incorporated in the zirconia. Excitation and emission spectra show the different mechanisms of the direct and non-direct excitation of the dopant ion (Pr3+), and the preferential relaxation of the material by charge transfer from the host (zirconia) to the 4f5d band and the 4f inter-level of the dopant ion (Pr3+). No evidence of energy transfer from the host to the dopant was observed.

Preparation of thermally stable nanocrystalline hydroxyapatite by hydrothermal method.

PubMed

Prakash Parthiban, S; Elayaraja, K; Girija, E K; Yokogawa, Y; Kesavamoorthy, R; Palanichamy, M; Asokan, K; Narayana Kalkura, S

2009-12-01

Thermally stable hydroxyapatite (HAp) was synthesized by hydrothermal method in the presence of malic acid. X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), differential thermal analysis (DTA), thermogravimetric analysis (TGA) was done on the synthesized powders. These analyses confirmed the sample to be free from impurities and other phases of calcium phosphates, and were of rhombus morphology along with nanosized particles. IR and Raman analyses indicated the adsorption of malic acid on HAp. Thermal stability of the synthesized HAp was confirmed by DTA and TGA. The synthesized powders were thermally stable upto 1,400 degrees C and showed no phase change. The proposed method might be useful for producing thermally stable HAp which is a necessity for high temperature coating applications.

Hydroxyapatite nanocrystals: simple preparation, characterization and formation mechanism.

PubMed

Mohandes, Fatemeh; Salavati-Niasari, Masoud; Fathi, Mohammadhossein; Fereshteh, Zeinab

2014-12-01

Crystalline hydroxyapatite (HAP) nanoparticles and nanorods have been successfully synthesized via a simple precipitation method. To control the shape and particle size of HAP nanocrystals, coordination ligands derived from 2-hydroxy-1-naphthaldehyde were first prepared, characterized by Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance ((1)H-NMR) spectroscopies, and finally applied in the synthesis process of HAP. On the other hand, the HAP nanocrystals were also characterized by several techniques including powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). According to the FE-SEM and TEM micrographs, it was found that the morphology and crystallinity of the HAP powders depended on the coordination mode of the ligands. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis of kalsilite from microcline powder by an alkali-hydrothermal process

NASA Astrophysics Data System (ADS)

Su, Shuang-qing; Ma, Hong-wen; Yang, Jing; Zhang, Pan; Luo, Zheng

2014-08-01

The properties of aluminosilicate kalsilite have attracted the interest of researchers in chemical synthesis, ceramic industry, biofuels, etc. In this study, kalsilite was hydrothermally synthesized from microcline powder in a KOH solution. The microcline powder, rich in potassium, aluminum, and silicon, was collected from Mountain Changling in Northwestern China. The effects of temperature, time, and KOH concentration on the decomposition of microcline were investigated. The kalsilite and intermediate products were characterized by means of wet chemistry analysis, X-ray Diffraction (XRD), infrared spectrometry (IR), 29Si magic angle spinning nuclear magnetic resonance (29Si MAS NMR), 27Al MAS NMR, and scanning electron microscope (SEM). With increasing temperature, the microcline powder transforms into a metastable KAlSiO4 polymorph before transforming further into pure kalsilite. A mixture of both kalsilite and metastable KAlSiO4 polymorph is obtained when the hydrothermal reaction is carried out within 2 h; but after 2 h, kalsilite is the predominant product. The concentration of KOH, which needs to be larger than 4.3 M, is an important parameter influencing the synthesis of kalsilite.

Formation of apatitic calcium phosphates in a Na-K-phosphate solution of pH 7.4.

PubMed

Tas, A C; Aldinger, F

2005-02-01

Poorly crystalline, apatitic calcium phosphate powders have been synthesized by slowly adding a Na- and K-containing reference phosphate solution with a pH value of 7.4 to an aqueous calcium nitrate solution at 37 degrees C. Nano-particulated apatitic powders obtained were shown to contain small amounts of Na and K, which render them more similar in chemical composition to that of the bone mineral. Precipitated and dried powders were found to exhibit self-hardening cement properties when kneaded in a mortar with a sodium citrate- and sodium phosphate-containing starter solution. The same phosphate solution used in powder synthesis was found to be able to partially convert natural, white and translucent marble pieces of calcite (CaCO3) into calcium-deficient hydroxyapatite upon aging the samples in that solution for 3 days at 60 degrees C. Sample characterization was performed by using scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, inductively-coupled plasma atomic emission spectroscopy, and simultaneous thermogravimetry and differential thermal analysis.

Nano-sized ZnO powders prepared by co-precipitation method with various pH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Purwaningsih, S. Y., E-mail: sriyanisaputri@gmail.com; Pratapa, S.; Triwikantoro,

2016-04-19

In this work, nano-sized ZnO powders have been synthesized by the co-precipitation method with Zn(CH3COOH)2.2H2O, HCl, and NH3.H2O as raw materials in various pH ranging from 8 to 10. The purity, microstructure, chemical group analysis, morphology of the prepared ZnO powders were studied by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), energy dispersive X-ray spectrometry (EDX), and scanning electron microscope (SEM), respectively. Rietveld refinement of XRD data showed that ZnO crystallizes in the wurtzite structure with high purity. The obtained powders were nano-sized particles with the average crystallite size about 17.9 ± 2.1 nm synthesized with pH of 9.5, atmore » 85°C, and stirring time of 6 h. The SEM results have visualied the morphology of ZnO nanoparticles with spherical-like shape. The effect of processing conditions on morphology of ZnO was also discussed.« less

Properties and Applications of High Emissivity Composite Films Based on Far-Infrared Ceramic Powder

PubMed Central

Xiong, Yabo; Huang, Shaoyun; Wang, Wenqi; Liu, Xinghai; Li, Houbin

2017-01-01

Polymer matrix composite materials that can emit radiation in the far-infrared region of the spectrum are receiving increasing attention due to their ability to significantly influence biological processes. This study reports on the far-infrared emissivity property of composite films based on far-infrared ceramic powder. X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray powder diffractometry were used to evaluate the physical properties of the ceramic powder. The ceramic powder was found to be rich in aluminum oxide, titanium oxide, and silicon oxide, which demonstrate high far-infrared emissivity. In addition, the micromorphology, mechanical performance, dynamic mechanical properties, and far-infrared emissivity of the composite were analyzed to evaluate their suitability for strawberry storage. The mechanical properties of the far-infrared radiation ceramic (cFIR) composite films were not significantly influenced (p ≥ 0.05) by the addition of the ceramic powder. However, the dynamic mechanical analysis (DMA) properties of the cFIR composite films, including a reduction in damping and shock absorption performance, were significant influenced by the addition of the ceramic powder. Moreover, the cFIR composite films showed high far-infrared emissivity, which has the capability of prolonging the storage life of strawberries. This research demonstrates that cFIR composite films are promising for future applications. PMID:29186047

Properties and Applications of High Emissivity Composite Films Based on Far-Infrared Ceramic Powder.

PubMed

Xiong, Yabo; Huang, Shaoyun; Wang, Wenqi; Liu, Xinghai; Li, Houbin

2017-11-29

Polymer matrix composite materials that can emit radiation in the far-infrared region of the spectrum are receiving increasing attention due to their ability to significantly influence biological processes. This study reports on the far-infrared emissivity property of composite films based on far-infrared ceramic powder. X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray powder diffractometry were used to evaluate the physical properties of the ceramic powder. The ceramic powder was found to be rich in aluminum oxide, titanium oxide, and silicon oxide, which demonstrate high far-infrared emissivity. In addition, the micromorphology, mechanical performance, dynamic mechanical properties, and far-infrared emissivity of the composite were analyzed to evaluate their suitability for strawberry storage. The mechanical properties of the far-infrared radiation ceramic (cFIR) composite films were not significantly influenced ( p ≥ 0.05) by the addition of the ceramic powder. However, the dynamic mechanical analysis (DMA) properties of the cFIR composite films, including a reduction in damping and shock absorption performance, were significant influenced by the addition of the ceramic powder. Moreover, the cFIR composite films showed high far-infrared emissivity, which has the capability of prolonging the storage life of strawberries. This research demonstrates that cFIR composite films are promising for future applications.

Detection of compatibility between baclofen and excipients with aid of infrared spectroscopy and chemometry

NASA Astrophysics Data System (ADS)

Rojek, Barbara; Wesolowski, Marek; Suchacz, Bogdan

2013-12-01

In the paper infrared (IR) spectroscopy and multivariate exploration techniques: principal component analysis (PCA) and cluster analysis (CA) were applied as supportive methods for the detection of physicochemical incompatibilities between baclofen and excipients. In the course of research, the most useful rotational strategy in PCA proved to be varimax normalized, while in CA Ward's hierarchical agglomeration with Euclidean distance measure enabled to yield the most interpretable results. Chemometrical calculations confirmed the suitability of PCA and CA as the auxiliary methods for interpretation of infrared spectra in order to recognize whether compatibilities or incompatibilities between active substance and excipients occur. On the basis of IR spectra and the results of PCA and CA it was possible to demonstrate that the presence of lactose, β-cyclodextrin and meglumine in binary mixtures produce interactions with baclofen. The results were verified using differential scanning calorimetry, differential thermal analysis, thermogravimetry/differential thermogravimetry and X-ray powder diffraction analyses.

Fourier transform infrared spectra and molecular structure of 5-methoxytryptamine, N-acetyl-5-methoxytryptamine and N-phenylsulfonamide-5-methoxytryptamine

NASA Astrophysics Data System (ADS)

Bayari, S.; Ide, S.

2003-04-01

5-Methoxytryptamine (5-MT) is a potent antioxidant and has radioprotective action. N-acetyl-5-methoxytryptamine (melatonin, NA-5-MT) is a free radical scavenger and antioxidant, which protects against oxidative damage due to a variety of toxicants. The infrared spectra of 5-MT, NA-5-MT and new synthesized N-phenylsulfonamide-5-methoxytryptamine (PS-5-MT) were investigated in the region between 4000 and 400 cm -1. Vibrational assignments of the molecules have been made for fundamental modes on the basis of the group vibrational concept, infrared intensity and comparison with the assignments for related molecules. X-ray powder diffraction patterns of molecules were also recorded. In order to optimize the geometries of the molecules, molecular mechanic calculations (MM3) were performed. Conformational analysis of 5-MT, NA-5-MT and PS-5-MT was also established by the using PM3 method.

A novel orange-red emitting NaCaVO{sub 4}:Sm{sup 3+} phosphor for solid state lighting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biswas, Pankaj, E-mail: pankaj79biswas@gmail.com; Kumar, Vinay, E-mail: vinaykdhiman@yahoo.com; Ntwaeaborwa, O. M.

2016-05-06

The samarium doped NaCaVO{sub 4} phosphor was synthesized by the combustion method. The X-ray powder diffraction (XRD) analysis confirmed that the phosphor powder crystallized as orthorhombic structure belonging to space group Cmcm. From Williamson-Hall analysis the grain size and microstrain in the powder was estimated. The Fourier- transform infrared (FT-IR) studies further validated the formation of vanadate phase of the phosphor. Photoluminescence (PL) study revealed that the phosphor could be efficiently excited by UV-VIS from 200 nm to 500 nm. The 565 nm, 602 nm, 648 nm and 713 nm emissions were ascribed to {sup 4}G{sub 5/2} to {sup 6}H{submore » J} (J = 5/2, 7/2, 9/2 and 11/2) transitions of the Sm{sup 3+} ion. The present material may be explored as a novel phosphor to be excited by UV light emitting diodes (LEDs) chips for solid-state lighting and display applications.« less

Some critical aspects of FT-IR, TGA, powder XRD, EDAX and SEM studies of calcium oxalate urinary calculi.

PubMed

Joshi, Vimal S; Vasant, Sonal R; Bhatt, J G; Joshi, Mihir J

2014-06-01

Urinary calculi constitute one of the oldest afflictions of humans as well as animals, which are occurring globally. The calculi vary in shape, size and composition, which influence their clinical course. They are usually of the mixed-type with varying percentages of the ingredients. In medical management of urinary calculi, either the nature of calculi is to be known or the exact composition of calculi is required. In the present study, two selected calculi were recovered after surgery from two different patients for detailed examination and investigated by using Fourier-Transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), powder X-ray diffraction (XRD), scanning electron microscopy and energy dispersive analysis of X-rays (EDAX) techniques. The study demonstrated that the nature of urinary calculi and presence of major phase in mixed calculi could be identified by FT-IR, TGA and powder XRD, however, the exact content of various elements could be found by EDAX only.

Magnetic, hyperthermic and structural properties of zn substituted CaFe2O4 powders

NASA Astrophysics Data System (ADS)

Kheradmand, Abbas; Vahidi, Omid; Masoudpanah, S. M.

2018-03-01

In the present study, we have synthesized single phase Ca1 - x Zn x Fe2O4 powders by hydrothermal method. The cation distribution between the tetrahedral and octahedral sites in the spinel structure and the magnetic properties as a function of the zinc substitution have been investigated by X-ray diffraction (XRD), infrared spectroscopy and vibrating sample magnetometer methods. The obtained XRD pattern indicated that the synthesized particles had single phase cubic spinel structure with no impurity. The magnetic measurements showed that the saturation magnetization increased from 83 to 98 emu/g with the addition of zinc due to the decrease of inversity. The particle size observed by electron microscopy decreased from 1.38 to 0.97 µm with the increase of zinc addition. The Ca0.7Zn0.3Fe2O4 powders exhibited appropriate heating capability for hyperthermia applications with the maximum AC heating temperature of 20 °C and specific loss power of 9.29 W/g.

Synthesis and characterization of CdO nano particles by the sol-gel method

NASA Astrophysics Data System (ADS)

Vadgama, V. S.; Vyas, R. P.; Jogiya, B. V.; Joshi, M. J.

2017-05-01

Cadmium Oxide (CdO) is an inorganic compound and one of the main precursors to other cadmium compounds. It finds applications in cadmium plating, storage batteries, in transparent conducting film, etc. Here, an attempt is made to synthesize CdO nano particles by sol-gel technique. The gel was prepared using cadmium nitrate tetra hydrate (Cd(NO3)2.4H2O) and aqueous ammonium hydroxide (NH4OH) as a precursor. The synthesized powder is further characterized by techniques like Powder X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and Thermal gravimetric analysis (TGA). Powder XRD analysis suggested the nano-crystalline nature of the sample with the cubic crystal system. Nano scaled particles of spherical morphology with the size ranging from 50-100 nm are observed from TEM images. While, FT-IR study is used to confirm the presence of different functional groups. Thermo-gravimetric analysis suggests the highly thermally stable nature of the samples. The results are discussed.

Synthesis of nano-titanium dioxide by sol-gel route

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaler, Vandana, E-mail: vandana.kaler@gmail.com; Duchaniya, R. K.; Pandel, U.

Nanosized titanium dioxide powder was synthesised via sol-gel route by hydrolysis of titanium tetraisopropoxide with ethanol and water mixture in high acidic medium. The synthesized nanopowder was further characterized by X-ray Diffraction, Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and Ultraviolet Visible Spectroscopy in order to determine size, morphology and crystalline structure of the material. The synthesis of nano-TiO{sub 2} powder in anatase phase was realized by XRD. The optical studies of nano-TiO{sub 2} powder was carried out by UV-Vis spectroscopy and band gap was calculated as 3.5eV, The SEM results with EDAX confirmed that prepared nano-TiO{sub 2} particles weremore » in nanometer range with irregular morphology. The FTIR analysis showed that only desired functional groups were present in sample. These nano-TiO{sub 2} particles have applications in solar cells, chemical sensors and paints, which are thrust areas these days.« less

Synthesis, characterization and electrical properties of a lead sodium vanadate apatite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakroun-Ouadhour, E.; Ternane, R.; Hassen-Chehimi, D. Ben

2008-08-04

The lacunary lead sodium vanadate apatite Pb{sub 8}Na{sub 2}(VO{sub 4}){sub 6} was synthesized by the solid-state reaction method. The compound was characterized by X-ray powder diffraction, infrared (IR) absorption spectroscopy and Raman scattering spectroscopy. By comparing the effect of vanadate and phosphate ions on electrical properties, it was concluded that Pb{sub 8}Na{sub 2}(VO{sub 4}){sub 6} apatite is better conductor than Pb{sub 8}Na{sub 2}(PO{sub 4}){sub 6} apatite.

Droplet-based microreactor for synthesis of water-soluble Ag₂S quantum dots.

PubMed

Shu, Yun; Jiang, Peng; Pang, Dai-Wen; Zhang, Zhi-Ling

2015-07-10

A droplet-based microreactor was used for synthesis of water-soluble Ag2S quantum dots (QDs). Monodispersed Ag2S nanoparticles with a surface of carboxylic acid-terminated were synthesized in the droplet microreactor. The x-ray powder diffraction results indicated products were monoclinic Ag2S nanocrystals. Furthermore, different-sized Ag2S QDs that were near-infrared-emitting or visible-emitting were continuously stably synthesized in droplet microreactors at different temperatures. We believe we offer a new method for obtaining different-sized Ag2S nanoparticles.

Droplet-based microreactor for synthesis of water-soluble Ag2S quantum dots

NASA Astrophysics Data System (ADS)

Shu, Yun; Jiang, Peng; Pang, Dai-Wen; Zhang, Zhi-Ling

2015-07-01

A droplet-based microreactor was used for synthesis of water-soluble Ag2S quantum dots (QDs). Monodispersed Ag2S nanoparticles with a surface of carboxylic acid-terminated were synthesized in the droplet microreactor. The x-ray powder diffraction results indicated products were monoclinic Ag2S nanocrystals. Furthermore, different-sized Ag2S QDs that were near-infrared-emitting or visible-emitting were continuously stably synthesized in droplet microreactors at different temperatures. We believe we offer a new method for obtaining different-sized Ag2S nanoparticles.

A simple method to synthesize polyhedral hexagonal boron nitride nanofibers

NASA Astrophysics Data System (ADS)

Lin, Liang-xu; Zheng, Ying; Li, Zhao-hui; shen, Xiao-nv; Wei, Ke-mei

2007-12-01

Hexagonal boron nitride (h-BN) fibers with polyhedral morphology were synthesized with a simple-operational, large-scale and low-cost method. The sample obtained was studied by X-ray photoelectron spectrometer (XPS), electron energy lose spectroscopy (EELS), X-ray powder diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR), etc., which matched with h-BN. Environment scanning electron microscopy (ESEM) and transmission electron microscope (TEM) indicated that the BN fibers possess polyhedral morphology. The diameter of the BN fibers is mainly in the range of 100-500 nm.

Preparation and Characterization of Mesoporous Zirconia Made by Using a Poly (methyl methacrylate) Template

NASA Astrophysics Data System (ADS)

Duan, Guorong; Zhang, Chunxiang; Li, Aimei; Yang, Xujie; Lu, Lude; Wang, Xin

2008-03-01

Superfine powders of poly (methyl methacrylate) (PMMA) have been prepared by means of an emulsion polymerization method. These have been used as templates in the synthesis of tetragonal phase mesoporous zirconia by the sol gel method, using zirconium oxychloride and oxalic acid as raw materials. The products have been characterized by infrared spectroscopy, X-ray diffraction analysis, transmission electron microscopy, N2 adsorption-desorption isotherms, and pore size distribution. The results indicate that the average pore size was found to be 3.7 nm.

Solvothermal synthesis of fusiform hexagonal prism SrCO{sub 3} microrods via ethylene glycol solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi Liange; Du Fanglin

2007-08-07

Fusiform hexagonal prism SrCO{sub 3} microrods were prepared by a simple solvothermal route at 120 deg. C, and characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and Fourier transform infrared (FT-IR) spectroscopy. By controlling the content of ethylene glycol (EG), it was found that ethylene glycol (EG) played an important role in the formation of such SrCO{sub 3} microrods. Finally, effects of other solvents on the products, including 1,2-propanediol and glycerin, were also investigated.

Novel polymorphs of the anti-Trypanosoma cruzi drug benznidazole

NASA Astrophysics Data System (ADS)

Honorato, Sara Braga; Mendonça, Jorge Souza; Boechat, Nubia; Oliveira, Alcemira Conceição; Mendes Filho, Josué; Ellena, Javier; Ayala, Alejandro Pedro

2014-01-01

Benznidazole (N-benzyl-2-(2-nitro-1H-imidazol-1-yl)acetamide), is a nitro-heterocyclic drug used in the treatment of Chagas disease. Despite the fact that this drug was released more than 30 years ago, little information about its solid state properties is available in the literature. In this study, it was verified that this drug exhibits three polymorphs, which were characterized in situ by X-ray powder diffraction, thermal analysis, hot stage microscopy and infrared spectroscopy. The thermodynamic relationships among these polymorphs were also discussed.

Reaction Heterogeneity in LiNi 0.8 Co 0.15 Al 0.05 O 2 Induced by Surface Layer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grenier, Antonin; Liu, Hao; Wiaderek, Kamila M.

2017-08-15

Through operando synchrotron powder X-ray diffraction (XRD) analysis of layered transition metal oxide electrodes of composition LiNi0.8Co0.15Al0.05O2 (NCA), we decouple the intrinsic bulk reaction mechanism from surface-induced effects. For identically prepared and cycled electrodes stored in different environments, we demonstrate that the intrinsic bulk reaction for pristine NCA follows solid-solution mechanism, not a two-phase as suggested previously. By combining high resolution powder X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and surface sensitive X-ray photoelectron spectroscopy (XPS), we demonstrate that adventitious Li2CO3 forms on the electrode particle surface during exposure to air, through reaction with atmospheric CO2. This surfacemore » impedes ionic and electronic transport to the underlying electrode, with progressive erosion of this layer during cycling giving rise to different reaction states in particles with an intact vs an eroded Li2CO3 surface-coating. This reaction heterogeneity, with a bimodal distribution of reaction states, has previously been interpreted as a “two-phase” reaction mechanism for NCA, as an activation step that only occurs during the first cycle. Similar surface layers may impact the reaction mechanism observed in other electrode materials using bulk probes such as operando powder XRD.« less

Atomically designed precursors in optical fiber amplifiers: The thermal stability of the heterobimetallic ErAl3(OPri)12 in a solution-coated silica soot

NASA Astrophysics Data System (ADS)

Engholm, M.; Lashgari, K.; Edvardsson, S.; Westin, G.; Norin, L.

2005-06-01

The thermal stability of the bimetallic alkoxide ErAl3(OPri)12 doped in an unsintered silica (soot) has been investigated. Samples have been heated to different temperatures (up to 1500°C and analyzed by using ultraviolet-visible-near infrared absorption spectroscopy, infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, thermal gravimetric analysis, and powder x-ray diffraction. It is seen that the doped samples heated up to 1000°C show broad glasslike absorption spectra, indicating an amorphous structure, while the high-temperature sample shows an ordered crystallinelike structure with sharp characteristic absorption peaks. X-ray diffraction measurements indicate the formation of an ordered structure at temperatures of 1500°C, revealing a crystal phase of silica and phases of erbium and aluminosilicate. A comparison is also made with a sample doped with aqueous ErCl3 and Al(NO3)3. It is concluded that the local structure of the ErAl3 precursor is not preserved at temperatures above 1000°C. Alternative doping procedures are discussed.

In Situ Probes of Capture and Decomposition of Chemical Warfare Agent Simulants by Zr-Based Metal Organic Frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plonka, Anna M.; Wang, Qi; Gordon, Wesley O.

Recently, Zr-based metal organic frameworks (MOFs) were shown to be among the fastest catalysts of nerve-agent hydrolysis in solution. Here, we report a detailed study of the adsorption and decomposition of a nerve-agent simulant, dimethyl methylphosphonate (DMMP), on UiO-66, UiO-67, MOF-808, and NU-1000 using synchrotron-based X-ray powder diffraction, X-ray absorption, and infrared spectroscopy, which reveals key aspects of the reaction mechanism. The diffraction measurements indicate that all four MOFs adsorb DMMP (introduced at atmospheric pressures through a flow of helium or air) within the pore space. In addition, the combination of X-ray absorption and infrared spectra suggests direct coordination ofmore » DMMP to the Zr6 cores of all MOFs, which ultimately leads to decomposition to phosphonate products. Our experimental probes into the mechanism of adsorption and decomposition of chemical warfare agent simulants on Zr-based MOFs open new opportunities in rational design of new and superior decontamination materials.« less

In Situ Probes of Capture and Decomposition of Chemical Warfare Agent Simulants by Zr-Based Metal Organic Frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plonka, Anna M.; Wang, Qi; Gordon, Wesley O.

Zr-based metal organic frameworks (MOFs) have been recently shown to be among the fastest catalysts of nerve-agent hydrolysis in solution. We report a detailed study of the adsorption and decomposition of a nerve-agent simulant, dimethyl methylphosphonate (DMMP), on UiO-66, UiO-67, MOF-808, and NU-1000 using synchrotron-based X-ray powder diffraction, X-ray absorption, and infrared spectroscopy, which reveals key aspects of the reaction mechanism. The diffraction measurements indicate that all four MOFs adsorb DMMP (introduced at atmospheric pressures through a flow of helium or air) within the pore space. In addition, the combination of X-ray absorption and infrared spectra suggests direct coordination ofmore » DMMP to the Zr6 cores of all MOFs, which ultimately leads to decomposition to phosphonate products. These experimental probes into the mechanism of adsorption and decomposition of chemical warfare agent simulants on Zr-based MOFs open new opportunities in rational design of new and superior decontamination materials.« less

In Situ Probes of Capture and Decomposition of Chemical Warfare Agent Simulants by Zr-Based Metal Organic Frameworks

DOE PAGES

Plonka, Anna M.; Wang, Qi; Gordon, Wesley O.; ...

2016-12-30

Recently, Zr-based metal organic frameworks (MOFs) were shown to be among the fastest catalysts of nerve-agent hydrolysis in solution. Here, we report a detailed study of the adsorption and decomposition of a nerve-agent simulant, dimethyl methylphosphonate (DMMP), on UiO-66, UiO-67, MOF-808, and NU-1000 using synchrotron-based X-ray powder diffraction, X-ray absorption, and infrared spectroscopy, which reveals key aspects of the reaction mechanism. The diffraction measurements indicate that all four MOFs adsorb DMMP (introduced at atmospheric pressures through a flow of helium or air) within the pore space. In addition, the combination of X-ray absorption and infrared spectra suggests direct coordination ofmore » DMMP to the Zr6 cores of all MOFs, which ultimately leads to decomposition to phosphonate products. Our experimental probes into the mechanism of adsorption and decomposition of chemical warfare agent simulants on Zr-based MOFs open new opportunities in rational design of new and superior decontamination materials.« less

JCPDS-ICDD Research Associateship (Cooperative Program with NBS/NIST)

PubMed Central

Wong-Ng, W.; McMurdie, H. F.; Hubbard, C. R.; Mighell, A. D.

2001-01-01

The Research Associateship program of the Joint Committee on Powder Diffraction-International Centre for Diffraction Data (JCPDS-ICDD, now known as the ICDD) at NBS/NIST was a long standing (over 35 years) successful industry-government cooperation. The main mission of the Associateship was to publish high quality x-ray reference patterns to be included in the Powder Diffraction File (PDF). The PDF is a continuing compilation of patterns gathered from many sources, compiled and published by the ICDD. As a result of this collaboration, more than 1500 high quality powder diffraction patterns, which have had a significant impact on the scientific community, were reported. In addition, various research collaborations with NBS/NIST also led to the development of several standard reference materials (SRMs) for instrument calibration and quantitative analyses, and computer software for data collection, calibration, reduction, for the editorial process of powder pattern publication, analysis of powder data, and for quantitative analyses. This article summarizes information concerning the JCPDS-ICDD organization, the Powder Diffraction File (PDF), history and accomplishments of the JCPDS-ICDD Research Associateship. PMID:27500061

Effects of various polyoxyethylene sorbitan monooils (Tweens) and sodium dodecyl sulfate on reflux synthesis of copper nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Xifeng; Yin Hengbo; Cheng Xiaonong

2006-11-09

Size-controlled synthesis of phase pure Cu nanoparticles was carried out by using copper sulfate pentahydrate as a precursor, ascorbic acid as a reductant, Tweens and sodium dodecyl sulfate (SDS) as modifiers in an aqueous solution at 80 deg. C. The as-prepared Cu nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and Fourier transform infrared (FT-IR). The stabilizing effects of SDS and Tweens on the Cu nanoparticles should be through the coordination between Cu nanoparticles and the respective sulfate group and oxygen-containing bond. The synergic effect of the composite SDS and Tweensmore » on Cu nanoparticles was different from those arising from the individuals.« less

Total-scattering pair-distribution function of organic material from powder electron diffraction data.

PubMed

Gorelik, Tatiana E; Schmidt, Martin U; Kolb, Ute; Billinge, Simon J L

2015-04-01

This paper shows that pair-distribution function (PDF) analyses can be carried out on organic and organometallic compounds from powder electron diffraction data. Different experimental setups are demonstrated, including selected area electron diffraction and nanodiffraction in transmission electron microscopy or nanodiffraction in scanning transmission electron microscopy modes. The methods were demonstrated on organometallic complexes (chlorinated and unchlorinated copper phthalocyanine) and on purely organic compounds (quinacridone). The PDF curves from powder electron diffraction data, called ePDF, are in good agreement with PDF curves determined from X-ray powder data demonstrating that the problems of obtaining kinematical scattering data and avoiding beam damage of the sample are possible to resolve.

Crystal Structure of 17α-Dihydroequilin, C18H22O2, from Synchrotron Powder Diffraction Data and Density Functional Theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaduk, James; Gindhart, Amy; Blanton, Thomas

The crystal structure of 17α-dihydroequilin has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. 17α-dihydroequilin crystallizes in space group P212121 (#19) with a = 6.76849(1) Å, b = 8.96849(1) Å, c = 23.39031(5) Å, V = 1419.915(3) Å3, and Z = 4. Both hydroxyl groups form hydrogen bonds to each other, resulting in zig-zag chains along the b-axis. The powder diffraction pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ as the entry 00-066-1608.

Effect of nano-sized cerium-zirconium oxide solid solution on far-infrared emission properties of tourmaline powders

NASA Astrophysics Data System (ADS)

Guo, Bin; Yang, Liqing; Hu, Weijie; Li, Wenlong; Wang, Haojing

2015-10-01

Far-infrared functional nanocomposites were prepared by the co-precipitation method using natural tourmaline (XY3Z6Si6O18(BO3)3V3W, where X is Na+, Ca2+, K+, or vacancy; Y is Mg2+, Fe2+, Mn2+, Al3+, Fe3+, Mn3+, Cr3+, Li+, or Ti4+; Z is Al3+, Mg2+, Cr3+, or V3+; V is O2-, OH-; and W is O2-, OH-, or F-) powders, ammonium cerium(IV) nitrate and zirconium(IV) nitrate pentahydrate as raw materials. The reference sample, tourmaline modified with ammonium cerium(IV) nitrate alone was also prepared by a similar precipitation route. The results of Fourier transform infrared spectroscopy show that tourmaline modified with Ce and Zr has a better far-infrared emission property than tourmaline modified with Ce alone. Through characterization by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), the mechanism for oxygen evolution during the heat process in the two composite materials was systematically studied. The XPS spectra show that Fe3+ ratio inside tourmaline modified with Ce alone can be raised by doping Zr. Moreover, it is showed that there is a higher Ce3+ ratio inside the tourmaline modified with Ce and Zr than tourmaline modified with Ce alone. In addition, XRD results indicate the formation of CeO2 and Ce1-xZrxO2 crystallites during the heat treatment and further TEM observations show they exist as nanoparticles on the surface of tourmaline powders. Based on these results, we attribute the improved far-infrared emission properties of Ce-Zr doped tourmaline to the enhanced unit cell shrinkage of the tourmaline arisen from much more oxidation of Fe2+ to Fe3+ inside the tourmaline caused by the change in the catalyst redox properties of CeO2 brought about by doping with Zr4+. In all samples, tourmaline modified with 7.14 wt.% Ce and 1.86 wt.% Zr calcined at 800∘C for 5 h has the best far-infrared emission property with the maximum emissivity value of 98%.

Process Parameters on the Crystallization and Morphology of Hydroxyapatite Powders Prepared by a Hydrolysis Method

NASA Astrophysics Data System (ADS)

Wang, Moo-Chin; Hon, Min-Hsiung; Chen, Hui-Ting; Yen, Feng-Lin; Hung, I.-Ming; Ko, Horng-Huey; Shih, Wei-Jen

2013-07-01

The effects of process parameters on the crystallization and morphology of hydroxyapatite (Ca10(PO4)6(OH)2, HA) powders synthesized from dicalcium phosphate dihydrate (CaHPO4·2H2O, DCPD) using a hydrolysis method have been investigated. X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) were used to characterize the synthesized powders. When DCPD underwent hydrolysis in 2.5 NaOH solution (Na(aq)) at 303 K to 348 K (30 °C to 75 °C) for 1 hour, the XRD results revealed that HA was obtained for all the as-dried samples. The SEM morphology of the HA powders for DCPD hydrolysis produced at 348 K (75 °C) shows regular alignment and a short rod shape with a size of 200 nm in length and 50 nm in width. With DCPD hydrolysis in 2.5 M NaOH(aq) holding at 348 K (75 °C) for 1 to 24 hours, XRD results demonstrated that all samples were HA and no other phases could be detected. Moreover, the XRD results also show that all the as-dried powders still maintained the HA structure when DCPD underwent hydrolysis in 0.1 to 5 M NaOH(aq) at 348 K (75 °C) for 1 hour. Otherwise, the full transformation from HA to octa-calcium phosphate (OCP, Ca8H2(PO4)6·5H2O) occurred when hydrolysis happened in 10 M NaOH(aq). FT-IR spectra analysis revealed that some carbonated HA (Ca10(PO4)6(CO3), CHA) had formed. The SEM morphology results show that the 60 to 65 nm width of the uniformly long rods with regular alignment formed in the HA powder aggregates when DCPD underwent hydrolysis in 2.5 M NaOH(aq) at 348 K (75 °C) for 1 hour.

New Powder Diffraction File (PDF-4) in relational database format: advantages and data-mining capabilities.

PubMed

Kabekkodu, Soorya N; Faber, John; Fawcett, Tim

2002-06-01

The International Centre for Diffraction Data (ICDD) is responding to the changing needs in powder diffraction and materials analysis by developing the Powder Diffraction File (PDF) in a very flexible relational database (RDB) format. The PDF now contains 136,895 powder diffraction patterns. In this paper, an attempt is made to give an overview of the PDF-4, search/match methods and the advantages of having the PDF-4 in RDB format. Some case studies have been carried out to search for crystallization trends, properties, frequencies of space groups and prototype structures. These studies give a good understanding of the basic structural aspects of classes of compounds present in the database. The present paper also reports data-mining techniques and demonstrates the power of a relational database over the traditional (flat-file) database structures.

Neutron and X-ray diffraction of plasma-sprayed zirconia-yttria thermal barrier coatings

NASA Technical Reports Server (NTRS)

Shankar, N. R.; Herman, H.; Singhal, S. P.; Berndt, C. C.

1984-01-01

ZrO2-7.8mol. pct. YO1.5, a fused powder, and ZrO2-8.7mol. pct. YO1.5, a prereacted powder, were plasma-sprayed onto steel substrates. Neutron diffraction and X-ray diffraction of the as-received powder, the powder plasma sprayed into water, as-sprayed coatings, and coatings heat-treated for 10 and 100 h were carried out to study phase transformations and ordering of the oxygen ions on the oxygen sublattice. The as-received fused powder has a much lower monoclinic percentage than does the pre-reacted powder, this resulting in a much lower monoclinic percentage in the coating. Heat treatment increases the percentages of the cubic and monoclinic phases, while decreasing the tetragonal content. An ordered tetragonal phase is detected by the presence of extra neutron diffraction peaks. These phase transformations and ordering will result in volume changes. The implications of these transformations on the performance of partially stabilized zirconia thermal barrier coatings is discussed.

Surface-functionalized cockle shell–based calcium carbonate aragonite polymorph as a drug nanocarrier

PubMed Central

Mohd Abd Ghafar, Syairah Liyana; Hussein, Mohd Zobir; Rukayadi, Yaya; Abu Bakar Zakaria, Md Zuki

2017-01-01

Calcium carbonate aragonite polymorph nanoparticles derived from cockle shells were prepared using surface functionalization method followed by purification steps. Size, morphology, and surface properties of the nanoparticles were characterized using transmission electron microscopy, field emission scanning electron microscopy, dynamic light scattering, zetasizer, X-ray powder diffraction, and Fourier transform infrared spectrometry techniques. The potential of surface-functionalized calcium carbonate aragonite polymorph nanoparticle as a drug-delivery agent were assessed through in vitro drug-loading test and drug-release test. Transmission electron microscopy, field emission scanning electron microscopy, and particle size distribution analyses revealed that size, morphology, and surface characterization had been improved after surface functionalization process. Zeta potential of the nanoparticles was found to be increased, thereby demonstrating better dispersion among the nanoparticles. Purification techniques showed a further improvement in the overall distribution of nanoparticles toward more refined size ranges <100 nm, which specifically favored drug-delivery applications. The purity of the aragonite phase and their chemical analyses were verified by X-ray powder diffraction and Fourier transform infrared spectrometry studies. In vitro biological response of hFOB 1.19 osteoblast cells showed that surface functionalization could improve the cytotoxicity of cockle shell–based calcium carbonate aragonite nanocarrier. The sample was also sensitive to pH changes and demonstrated good abilities to load and sustain in vitro drug. This study thus indicates that calcium carbonate aragonite polymorph nanoparticles derived from cockle shells, a natural biomaterial, with modified surface characteristics are promising and can be applied as efficient carriers for drug delivery. PMID:28572724

Investigation of nanocrystalline zinc chromite obtained by two soft chemical routes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gingasu, Dana; Mindru, Ioana, E-mail: imandru@yahoo.com; Culita, Daniela C.

2014-01-01

Graphical abstract: - Highlights: • Two soft chemical routes to synthesize zinc chromites are described. • Glycine is used as chelating agent (precursor method) and fuel (solution combustion method). • The synthesized chromites have crystallite size in the range of 18–27 nm. • An antiferromagnetic (AFM) transition is observed at about T{sub N} ∼ 18 K. - Abstract: Zinc chromite (ZnCr{sub 2}O{sub 4}) nanocrystalline powders were obtained by two different chemical routes: the precursor method and the solution combustion method involving glycine-nitrates. The complex compound precursors, [ZnCr{sub 2}(NH{sub 2}CH{sub 2}COO){sub 8}]·9H{sub 2}O and [ZnCr{sub 2}(NH{sub 2}CH{sub 2}COOH){sub 4.5}]·(NO{sub 3}){sub 8}·6H{submore » 2}O, were characterized by chemical analysis, infrared spectroscopy (IR), ultraviolet–visible spectroscopy (UV–vis) and thermal analysis. The structure, morphology, surface chemistry and magnetic properties of ZnCr{sub 2}O{sub 4} powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), infrared and Raman spectroscopy (RS), ultraviolet–visible spectroscopy (UV–vis) and magnetic measurements. X-ray diffraction patterns indicated the chromite spinel phase with good crystallinity and an average crystallite size of approximately 18–27 nm. The band gap values ranged between 3.31 and 3.33 eV. The magnetic measurements indicated an antiferromagnetic transition at T{sub N} ∼ 17.5/18 K.« less

Zr doping dependence of structural and magnetic properties of cobalt ferrite synthesized by sol-gel based Pechini method

NASA Astrophysics Data System (ADS)

Motavallian, Pourya; Abasht, Behzad; Abdollah-Pour, Hassan

2018-04-01

Nanocrystalline CoZrxFe2-xO4 (0 ≤ x ≤ 0.3 in a step of 0.05) powders were synthesized by Pechini sol-gel method. The dry gel was grinded and calcined at 700 °C in a static air atmosphere for 1 h. Some tests such as thermo gravimetric analysis (TGA) combined with differential analysis (DTA), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometer (VSM) were carried out to investigate the thermal behaviour, structural bonds identification, crystallographic properties, morphology and magnetic properties of the obtained powders. X-ray diffraction revealed a single-phase cubic spinel structure for all samples, where the crystallite size decreases; the lattice parameter simultaneously increases with substitution of Zr. The results of FE-SEM showed that the particle size is in the 20-70 nm range. The magnetic properties such as saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) were measured from the hysteresis loops. The greatest amount of saturation magnetization for CoZr0.05Fe1.95O4 sample was 67.9 emu·g-1.

Synthesis and characterization of nanosized lithium manganate and its derivatives

NASA Astrophysics Data System (ADS)

Iqbal, Muhammad Javed; Zahoor, Sabia

Spinel lithium manganese oxide, LiMn 2O 4 and its derivatives are prepared by the sol-gel method. The lattice constant of the pure material is calculated as 8.23 Å. Different transition metal cations of chromium, iron, cobalt, nickel, copper and zinc (0.05 and 0.15 M) are doped in place of manganese in the LiMn 2O 4. X-ray powder diffraction data show that the spinel framework preserved its integrity upon doping. Formation of a single phase and the purity of the samples are confirmed by X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). The crystallite size of the samples is calculated by use of the Scherrer formula and is found to be within a range of 43-66 nm. The electrical conductivity of the samples is determined over a temperature range of 200-300 K by means of four-point probe method. An increasing trend of conductivity with increase in temperature is noted for all the samples. The parent compound LiMn 2O 4 has a conductivity value of 3.47 × 10 -4 ohm -1 cm -1 at room temperature. This value increases on doping with the above-mentioned transition metal cations.

Development of carvedilol-cyclodextrin inclusion complexes using fluid-bed granulation: a novel solid-state complexation alternative with technological advantages.

PubMed

Alonso, Ellen C P; Riccomini, Karina; Silva, Luis Antônio D; Galter, Daniela; Lima, Eliana M; Durig, Thomas; Taveira, Stephania F; Martins, Felipe Terra; Cunha-Filho, Marcílio S S; Marreto, Ricardo N

2016-10-01

This study sought to evaluate the achievement of carvedilol (CARV) inclusion complexes with modified cyclodextrins (HPβCD and HPγCD) using fluid-bed granulation (FB). The solid complexes were produced using FB and spray drying (SD) and were characterised by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction, SEM, flowability and particle size analyses and in vitro dissolution. The DSC, FTIR and powder X-ray diffraction findings suggested successful CARV inclusion in the modified β- and γ-cyclodextrins, which was more evident in acidic media. The CARV dissolution rate was ~7-fold higher for complexes with both cyclodextrins prepared using SD than for raw CARV. Complexes prepared with HPβCD using FB also resulted in a significant improvement in dissolution rate (~5-fold) and presented superior flowability and larger particle size. The findings suggested that FB is the best alternative for large-scale production of solid dosage forms containing CARV. Additionally, the results suggest that HPγCD could be considered as another option for CARV complexation because of its excellent performance in inclusion complex formation in the solid state. © 2016 Royal Pharmaceutical Society.

Reaction of Pb(II) and Zn(II) with Ethyl Linoleate To Form Structured Hybrid Inorganic–Organic Complexes: A Model for Degradation in Historic Paint Films

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacDonald, Margaret G.; Palmer, Michael R.; Suchomel, Matthew R.

To investigate soap formation in drying oils in historic paints, the reaction between metal acetates (K +, Zn 2+, Pb 2+) and ethyl linoleate (EL) was studied using optical microscopy, X-ray powder diffraction, and electron microscopy. Pb(II) and Zn(II) react rapidly with EL to form highly structured, spherulitic, luminescent crystallites that aggregate. Evidence from Fourier transform infrared (FTIR) and scanning electron microscopy/energy dispersive X-ray analysis and high-resolution synchrotron powder X-ray diffraction indicates that these are organic-inorganic hybrid complexes or coordination polymers. FTIR absorbance peaks at ca. 1540 cm -1 for Pb(II) and ca. 1580 cm -1 for Zn(II) are consistentmore » with the formation of carboxylate complexes. The complexes formed offer insight into the degradation processes observed in oil paint films, suggesting that soap formation is rapid when metal ions are solubilized and can occur with unsaturated fatty acids that are present in fresh oils. Finally, these complexes may account for the atypical luminescence observed in lead-containing cured oil paint films.« less

Reaction of Pb(II) and Zn(II) with Ethyl Linoleate To Form Structured Hybrid Inorganic–Organic Complexes: A Model for Degradation in Historic Paint Films

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacDonald, Margaret G.; Palmer, Michael R.; Suchomel, Matthew R.

To investigate soap formation in drying oils in historic paints, the reaction between metal acetates (K +, Zn 2+, Pb 2+) and ethyl linoleate (EL) was studied using optical microscopy, X-ray powder diffraction, and electron microscopy. Pb(II) and Zn(II) react rapidly with EL to form highly structured, spherulitic, luminescent crystallites that aggregate. Evidence from Fourier transform infrared (FTIR) and scanning electron microscopy/energy dispersive X-ray analysis and high-resolution synchrotron powder X-ray diffraction indicates that these are organic–inorganic hybrid complexes or coordination polymers. FTIR absorbance peaks at ca. 1540 cm –1 for Pb(II) and ca. 1580 cm –1 for Zn(II) are consistentmore » with the formation of carboxylate complexes. The complexes formed offer insight into the degradation processes observed in oil paint films, suggesting that soap formation is rapid when metal ions are solubilized and can occur with unsaturated fatty acids that are present in fresh oils. These complexes may account for the atypical luminescence observed in lead-containing cured oil paint films.« less

Reaction of Pb(II) and Zn(II) with Ethyl Linoleate To Form Structured Hybrid Inorganic–Organic Complexes: A Model for Degradation in Historic Paint Films

DOE PAGES

MacDonald, Margaret G.; Palmer, Michael R.; Suchomel, Matthew R.; ...

2016-09-07

To investigate soap formation in drying oils in historic paints, the reaction between metal acetates (K +, Zn 2+, Pb 2+) and ethyl linoleate (EL) was studied using optical microscopy, X-ray powder diffraction, and electron microscopy. Pb(II) and Zn(II) react rapidly with EL to form highly structured, spherulitic, luminescent crystallites that aggregate. Evidence from Fourier transform infrared (FTIR) and scanning electron microscopy/energy dispersive X-ray analysis and high-resolution synchrotron powder X-ray diffraction indicates that these are organic-inorganic hybrid complexes or coordination polymers. FTIR absorbance peaks at ca. 1540 cm -1 for Pb(II) and ca. 1580 cm -1 for Zn(II) are consistentmore » with the formation of carboxylate complexes. The complexes formed offer insight into the degradation processes observed in oil paint films, suggesting that soap formation is rapid when metal ions are solubilized and can occur with unsaturated fatty acids that are present in fresh oils. Finally, these complexes may account for the atypical luminescence observed in lead-containing cured oil paint films.« less

Structure and Dynamics Investigations of Sr/Ca-Doped LaPO 4 Proton Conductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

al-Wahish, Amal; al-Binni, U.; Tetard, L.

Proton conductors loom out of the pool of candidate materials with great potential to boost hydrogen alternatives to fossil-based resources for energy. Acceptor doped lanthanum orthophosphates are considered for solid oxide fuel cells (SOFCs) for their potential stability and conductivity at high temperature. By exploring the crystal and defect structure of x% Sr/Ca-doped LaPO 4 with different nominal Sr/Ca concentrations (x = 0 – 10) with Neutron powder diffraction (NPD) and X-ray powder diffraction (XRD), we confirm that Sr/Ca-doped LaPO 4 can exist as self-supported structures at high temperatures during solid oxide fuel cell operation. Thermal stability, surface topography, sizemore » distribution are also studied to better understand the proton conductivity for dry and wet compounds obtained at sintering temperatures ranging from 1200 to 1400 °C using a combination of scanning electron microscopy (SEM), Atomic Force Microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). In conclusion, the results suggest that Sr doped samples exhibit the highest proton conductivity of our samples and illustrate the impact of material design and versatile characterization schemes on the development of proton conductors with superior functionality.« less

Total-scattering pair-distribution function of organic material from powder electron diffraction data

DOE PAGES

Gorelik, Tatiana E.; Billinge, Simon J. L.; Schmidt, Martin U.; ...

2015-04-01

This paper shows for the first time that pair-distribution function analyses can be carried out on organic and organo-metallic compounds from powder electron diffraction data. Different experimental setups are demonstrated, including selected area electron diffraction (SAED) and nanodiffraction in transmission electron microscopy (TEM) or nanodiffraction in scanning transmission electron microscopy (STEM) modes. The methods were demonstrated on organo-metallic complexes (chlorinated and unchlorinated copper-phthalocyanine) and on purely organic compounds (quinacridone). The PDF curves from powder electron diffraction data, called ePDF, are in good agreement with PDF curves determined from X-ray powder data demonstrating that the problems of obtaining kinematical scattering datamore » and avoiding beam-damage of the sample are possible to resolve.« less

Molecular structure of hybrid imino-chalcone in the solid state: X-ray diffraction, spectroscopy study and third-order nonlinear optical properties

NASA Astrophysics Data System (ADS)

Custodio, J. M. F.; Santos, F. G.; Vaz, W. F.; Cunha, C. E. P.; Silveira, R. G.; Anjos, M. M.; Campos, C. E. M.; Oliveira, G. R.; Martins, F. T.; da Silva, C. C.; Valverde, C.; Baseia, B.; Napolitano, H. B.

2018-04-01

A comprehensive structural study of the compound (2E)-1-((E)-4-(4-methoxybenzylideneamino)phenyl)-3-(4-methoxyphenyl)prop-2-en-1-one was carried out in this work. Single crystal X-ray diffraction (SCXRD), X-ray powder diffraction (XRPD), NMR, Raman and Infrared spectroscopies, and DFT calculations were performed for characterization of this iminochalcone hybrid. Intermolecular interactions were described by Hirshfeld surface analysis derived from crystal structure. Reactivity and intramolecular charge transfer were investigated using the frontier molecular orbitals and molecular electrostatic potential. In addition, we have calculated the Nonlinear Optical Properties at the CAM-B3LYP/6-311+g(d) level of theory in the presence of different solvents (gas-phase, acetone, chloroform, dichloromethane, dimethyl sulfoxide, ethanol, methanol, and water), being found meaningful NLO parameters for our compound. At last, there is a good agreement between calculated and experimental IR spectrum, allowing the assignment of some of normal vibrational modes of the iminochalcone hybrid.

Studies on the growth, structural, spectral and third-order nonlinear optical properties of ammonium 3-carboxy-4-hydroxy benzenesulfonate monohydrate single crystal.

PubMed

Silambarasan, A; Krishna Kumar, M; Thirunavukkarasu, A; Mohan Kumar, R; Umarani, P R

2015-01-25

An organic nonlinear optical bulk single crystal, Ammonium 3-carboxy-4-hydroxy benzenesulfonate monohydrate (ACHBS) was successfully grown by solution growth technique. Single crystal X-ray diffraction study confirms that, the grown crystal belongs to P21/c space group. Powder X-ray diffraction and high resolution X-ray diffraction analyses revealed the crystallinity of the grown crystal. Infrared spectral analysis showed the vibrational behavior of chemical bonds and its functional groups. The thermal stability and decomposition stages of the grown crystal were studied by TG-DTA analysis. UV-Visible transmittance studies showed the transparency region and cut-off wavelength of the grown crystal. The third-order nonlinear optical susceptibility of the grown crystal was estimated by Z-scan technique using He-Ne laser source. The mechanical property of the grown crystal was studied by using Vicker's microhardness test. Copyright © 2014 Elsevier B.V. All rights reserved.

A porous Cd(II) metal-organic framework with high adsorption selectivity for CO2 over CH4

NASA Astrophysics Data System (ADS)

Zhu, Chunlan

2017-05-01

Metal-organic frameworks (MOFs) have attracted a lot of attention in recent decades. We applied a semi-rigid four-carboxylic acid linker to assemble with Cd(II) ions to generate a novel microporous Cd(II) MOF material. Single crystal X-ray diffraction study reveals the different two dimension (2D) layers can be further packed together with an AB fashion by hydrogen bonds (O4sbnd H4⋯O7 = 1.863 Å) to construct a three dimension (3D) supermolecular architecture. The resulting sample can be synthesized under solvothermal reactions successfully, which exhibits high selectivity adsorption of CO2 over CH4 at room temperature. In addition, the obtained sample was characterized by thermal gravimetric analyses (TGA), Fourier-transform infrared spectra (FT-IR), elemental analysis (CHN) and powder X-ray diffraction (PXRD).

Raman structural studies of the nickel electrode

NASA Technical Reports Server (NTRS)

Cornilsen, Bahne C.

1994-01-01

The objectives of this investigation have been to define the structures of charged active mass, discharged active mass, and related precursor materials (alpha-phases), with the purpose of better understanding the chemical and electrochemical reactions, including failure mechanisms and cobalt incorporation, so that the nickel electrode may be improved. Although our primary tool has been Raman spectroscopy, the structural conclusions drawn from the Raman data have been supported and augmented by three other analysis methods: infrared spectroscopy, powder X-ray Diffraction (XRD), and x-ray absorption spectroscopy (in particular EXAFS, Extended X-ray Absorption Fine Structure spectroscopy).

Preparation and Characterization of Cabamazepine Cocrystal in Polymer Solution.

PubMed

Zhang, Hao; Zhu, Ying; Qiao, Ning; Chen, Yang; Gao, Linghuan

2017-12-01

In this study, we attempted to prepare carbamazepine (CBZ) cocrystal through the solution method in ethanol-water solvent mixture (volume ratio 1:1) and polyvinyl pyrrolidone (PVP) solution. Nicotinamide (NIC) and saccharin (SAC) were selected as cocrystal coformers. Cocrystal screening products were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Powder X-ray Diffraction (PXRD) techniques. Characterization results show that in ethanol-water solvent mixture, pure CBZ-NIC cocrystal can be prepared, while CBZ-SAC cocrystal cannot be obtained. The addition of PVP can inhibit CBZ-NIC cocrystal formation and facilitate CBZ-SAC cocrystal formation.

Preparation and Characterization of Carbamazepine Cocrystal in Polymer Solution

PubMed Central

Zhang, Hao; Zhu, Ying; Chen, Yang; Gao, Linghuan

2017-01-01

In this study, we attempted to prepare carbamazepine (CBZ) cocrystal through the solution method in ethanol-water solvent mixture (volume ratio 1:1) and polyvinyl pyrrolidone (PVP) solution. Nicotinamide (NIC) and saccharin (SAC) were selected as cocrystal coformers. Cocrystal screening products were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Powder X-ray Diffraction (PXRD) techniques. Characterization results show that in ethanol-water solvent mixture, pure CBZ-NIC cocrystal can be prepared, while CBZ-SAC cocrystal cannot be obtained. The addition of PVP can inhibit CBZ-NIC cocrystal formation and facilitate CBZ-SAC cocrystal formation. PMID:29194387

Adsorption of methyl green on montmorillonite

NASA Astrophysics Data System (ADS)

Margulies, Leon; Rozen, Harel

1986-03-01

Adsorption of the dye methyl green (MG) on Na -montmorillonite (Clay) takes place through a cation exchange mechanism. At low and high MG loads, each MG molecule replaces approximately two and one Na + ions, respectively. Interactions between MG and Clay were studied using visible absorption and FTIR spectroscopies, and the orientation of the adsorbed molecules were determined by infrared linear dichroism and X-ray powder diffraction. The dye molecules are preferentially oriented with their plane parallel to the clay surface. The influence of MG load on the adsorption of two additional organic molecules, benzyl benzoate and benzophenone, was also studied.

Spectroscopic characterization of nanohydroxyapatite synthesized by molten salt method.

PubMed

Gopi, D; Indira, J; Kavitha, L; Kannan, S; Ferreira, J M F

2010-10-01

Hydroxyapatite (HAP) nanopowders were synthesized by molten salt method at 260 degrees C. The as-prepared powders were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM) and thermo gravimetric analysis (TGA). With the aid of the obtained results the effect of calcining time on the crystallinity, size and morphology of HAP nanopowders is presented. The HAP nanopowders synthesized by molten salt method consist of pure phase of HAP without any impurities and showed the rod-like morphology without detectable decomposition up to 1100 degrees C. Copyright 2010 Elsevier B.V. All rights reserved.

Methods of amorphization and investigation of the amorphous state.

PubMed

Einfal, Tomaž; Planinšek, Odon; Hrovat, Klemen

2013-09-01

The amorphous form of pharmaceutical materials represents the most energetic solid state of a material. It provides advantages in terms of dissolution rate and bioavailability. This review presents the methods of solid- -state amorphization described in literature (supercooling of liquids, milling, lyophilization, spray drying, dehydration of crystalline hydrates), with the emphasis on milling. Furthermore, we describe how amorphous state of pharmaceuticals differ depending on the method of preparation and how these differences can be screened by a variety of spectroscopic (X-ray powder diffraction, solid state nuclear magnetic resonance, atomic pairwise distribution, infrared spectroscopy, terahertz spectroscopy) and calorimetry methods.

Analysis of pigments from Roman wall paintings found in the "agro centuriato" of Julia Concordia (Italy).

PubMed

Mazzocchin, Gian-Antonio; Del Favero, Michela; Tasca, Giovanni

2007-09-01

The analysis of wall painting fragments recovered in the "agro centuriato" of Julia Concordia has been carried out by using Scanning Electron Microscopy equipped with an EDS microanalysis detector (SEM-EDS), Infrared Spectroscopy (FTIR) and X-Ray powder Diffraction (XRD). The pigments used have been identified and the data obtained suggest the presence of three rustic villas richly decorated also with Egyptian blue. The presence of white of aragonite suggest that these villas were decorated during the Imperial Age, in agreement with the recovery of high quality materials and a bronze statue.

Effect of Tourmaline-Doped on the Far Infrared Emission of Iron Ore Tailings Ceramics.

PubMed

Liu, Jie; Meng, Junping; Liang, Jinsheng; Zhang, Hongchen; Gu, Xiaoyang

2016-04-01

Iron ore tailings as secondary resources have been of great importance to many countries in the world. Their compositions are similar to that of infrared emission ceramics, but there are few reports about it. In addition, tourmaline has high infrared emission properties due to its unique structure. With the purpose of expanding functional utilization of iron ore tailings, as well as reducing the production cost of far infrared ceramics, a new kind of far infrared emission ceramics was prepared by using iron ore tailings, calcium carbonate, silica, and natural tourmaline. The ceramics powders were characterized by Fourier transform infrared spectroscope, X-ray diffraction and scanning electron microscopy, respectively. The results show that after being sintered at 1065 °C, the percentage of pseudobrookite and lattice strain of samples increased with increasing the elbaite content. Furthermore, the added tourmaline was conducive to the densification sintering of ceramics. The appearance of Li-O vibration at 734.73 cm-1, as well as the strengthened Fe-O vibration at 987.68 cm-1 were attributed to the formation of Li0.375Fe1.23Ti1.4O5 solid solution, which led the average far infrared emissivity of ceramics increase from 0.861 to 0.906 within 8-14 µm.

Crystal Growth and Luminescence Properties of Yb-doped Gd3Al2Ga3O12 Infra-red Scintillator

NASA Astrophysics Data System (ADS)

Suzuki, Akira; Kurosawa, Shunsuke; Nagata, Shinji; Yamamura, Tomoo; Pejchal, Jan; Yamaji, Akihiro; Yokota, Yuui; Shirasaki, Kenji; Homma, Yoshiya; Aoki, Dai; Shikama, Tatsuo; Yoshikawa, Akira

2014-07-01

1-mol%-Yb-doped Gd3Al2Ga3O12 infra-red scintillator crystal has been studied as a novel implantable radiation monitor in radiation therapy. Powder X-ray diffraction measurement and chemical analysis with a field emission scanning microscope and wavelength dispersive spectrometer determined its garnet structure and average chemical composition of Yb0.03±0.01Gd2.99±0.07Al2.21±0.08Ga2.64±0.09O12.10±0.09. Transmittance measurements reached high values of approximately 70% in the human body transparency region between 650 to 1200 nm. Photoluminescence peaks were detected around 970 and 1030 nm under the 940 nm excitation with a Xe lamp. Infra-red scintillation emissions were clearly observed around 970 and 1030 nm due to Yb3+ 4f-4f transitions under X-ray excitation. Therefore, these results suggest that Yb-doped Gd3Al2Ga3O12 might be used as an infra-red scintillator material.

The influence of Ni(II) on brushite structure stabilization

NASA Astrophysics Data System (ADS)

Guerra-López, J. R.; Güida, J. A.; Ramos, M. A.; Punte, G.

2017-06-01

Brushite samples doped with Ni(II) in different concentrations, from 5% to 20%, were prepared in aqueous solution at pH = 7 and at two temperatures: 25 and 37 °C. The solid samples were characterized by chemical analysis, infrared spectroscopy (FTIR) and x-ray powder diffraction (XRPD). Chemical analysis has shown Ni(II) almost complete incorporation to the solid phase up to 15%. X-ray diffraction patterns have allowed to identify brushite phase with almost no modification of the line breadth and only small shifts of lines positions with increasing Ni(II) incorporation up to 15%. For larger Ni(II) concentration, in solution, a mixture of phases has been detected. Infrared spectra have supported diffraction results. For Ni(II) 20% and over the characteristic bands of HPO42- anions tend to vanish, and the typical shaped PO43- bands are observed. These results have allowed to establish that the presence of low levels of Ni in the synthetic process not only helps brushite formation; but, also prevents brushite from apatite conversion and, in addition, preserves brushite crystallinity. According to these findings, it is possible to propose that nickel traces present in the urinary system might be a trigger to brushite stone formation and/or growth, rather than the expected brushite conversion to hydroxyapatite. This outcome would explain the recurrent detection of difficult to treat brushite stones, observed in the last three decades.

Synthesis of PZT powder by conventional method at various conditions

NASA Astrophysics Data System (ADS)

Necira, Z.; Boutarfaia, A.; Abba, M.; Abdessalem, N.

2012-06-01

In this work, the formation of Pb(Zr1-xTix)O3 solid solutions with composition near the morphotropic phase boundary (MPB) using the conventional ceramic method have been studied by changing the thermal conditions such as temperature ramp rate and isothermal times during the calcination treatment performed between 700 and 900 °C. The perovskite phase formation and morphology of undoped Pb(Zr0.52Ti0.48)O3 (abbreviated PZT) and doped new material Pb0.98Gd0.02[(Zr0.52Ti0.48)0.98 (Mg1/3Nb2/3)0.01 (Ni1/3Sb2/3)0.01]O3 (abbreviated PZT-PGMNNS) specimens have been examined by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) while the thermal evolution of the initial precursor was followed by TG-DTA. So the results of these studies have been discussed.

Microstructural, optical and electrical transport properties of Cd-doped SnO2 nanoparticles

NASA Astrophysics Data System (ADS)

Ahmad, Naseem; Khan, Shakeel; Mohsin Nizam Ansari, Mohd

2018-03-01

We have successfully investigated the structural, optical and dielectric properties of Cd assimilated SnO2 nanoparticles synthesized via very convenient precipitation route. The structural properties were studied by x-ray diffraction method (XRD) and Fourier Transform Infrared (FTIR) Spectroscopy. As-synthesized samples in the form of powder were examined for its morphology and average particle size by Transmission electron microscopy (TEM). The optical properties were studied by diffuse reflectance spectroscopy. Dielectric properties such that complex dielectric constant and ac conductivity were investigated by LCR meter. Average crystallite size calculated by XRD and average particle size obtained from TEM were found to be consistent and below 50 nm for all samples. The optical band gap of as-synthesized powder samples from absorption study was found in the range of 3.76 to 3.97 eV. The grain boundary parameters such that Rgb, Cgb and τ were evaluated using impedance spectroscopy.

Porous aerosil loading probucol using supercritical carbon dioxide: preparation, in vitro and in vivo characteristics.

PubMed

Chu, Chunxia; Liu, Muhua; Wang, Dongmei; Guan, Jibin; Cai, Cuifang; Sun, Yuanpeng; Zhang, Tianhong

2014-06-01

The aim of this study was to enhance the dissolution rate and oral bioavailability of probucol. Probucol was adsorbed onto aerosils via supercritical carbon dioxide (ScCO2) and the physicochemistry properties of probucol-aerosil powder were evaluated by differential scanning calorimetry, X-ray diffraction, infrared spectroscopy and scanning electron microscopy. Tablets of the probucol-aerosil powder were prepared by direct compression method. In the dissolution test, the probucol-aerosil tablets showed a significant enhanced dissolution rate compared with commercial tablets. Bioavailability study was carried out in beagle dogs. Probucol-aerosil tablets exhibited higher AUC and Cmax than commercial tablets. The improved dissolution and bioavailability of probucol-aerosil tablets were attributed to the amorphous state and good dispersion of probucol. It is a feasible method to enhance the oral bioavailability by adsorbing probucol onto aerosils via ScCO2.

Synthesis of the complex fluoride LiBaF 3 and optical spectroscopy properties of LiBaF 3: M( M=Eu,Ce) through a solvothermal process

NASA Astrophysics Data System (ADS)

Hua, Ruinian; Lei, Bingfu; Xie, Demin; Shi, Chunshan

2003-11-01

The complex fluoride LiBaF 3 and LiBaF 3: M( M=Eu, Ce) is solvothermally synthesized at 180°C and characterized by means of X-ray powder diffraction, scanning electron microscopy, thermogravimetric analysis and infrared spectroscopy. In the solvothermal process, the solvents, molar ratios of initial mixtures and reaction temperature play important roles in the formation of products. The excitation and emission spectra of the LiBaF 3: M( M=Eu,Ce) have been measured by fluorescence spectrophotometer. In the LiBaF 3:Eu emission spectra, there is one sharp line emission located at 360 nm arising from f→ f transition of Eu 2+ in the host lattice, and typical doublet 5 d-4 f emission of Ce 3+ in LiBaF 3 powder is shown.

Intercalation of paracetamol into the hydrotalcite-like host

NASA Astrophysics Data System (ADS)

Kovanda, František; Maryšková, Zuzana; Kovář, Petr

2011-12-01

Hydrotalcite-like compounds are often used as host structures for intercalation of various anionic species. The product intercalated with the nonionic, water-soluble pharmaceuticals paracetamol, N-(4-hydroxyphenyl)acetamide, was prepared by rehydration of the Mg-Al mixed oxide obtained by calcination of hydrotalcite-like precursor at 500 °C. The successful intercalation of paracetamol molecules into the interlayer space was confirmed by powder X-ray diffraction and infrared spectroscopy measurements. Molecular simulations showed that the phenolic hydroxyl groups of paracetamol interact with hydroxide sheets of the host via the hydroxyl groups of the positively charged sites of Al-containing octahedra; the interlayer water molecules are located mostly near the hydroxide sheets. The arrangement of paracetamol molecules in the interlayer is rather disordered and interactions between neighboring molecules cause their tilting towards the hydroxide sheets. Dissolution tests in various media showed slower release of paracetamol intercalated in the hydrotalcite-like host in comparison with tablets containing the powdered pharmaceuticals.

Synthesis of thoria nano-particles at low temperature through base electrogeneration on steel 316L surface: Effect of current density

NASA Astrophysics Data System (ADS)

Yousefi, Taher; Torab-Mostaedi, Meisam; Mobtaker, Hossein Ghasemi; Keshtkar, Ali Reza

2016-10-01

The strategy developed in this study, offers significant advantages (simplicity and cleanness of method and also a product purity and new morphology of the product) over the conventional routes for the synthesis of ThO2 nanostructure. The effect of current density on morphology was studied. The synthesized powder was characterized by means of Powder X-ray Diffraction (PXRD), Transmission Electron Microscopy (TEM, Phillips EM 2085) Brunauer-Emmett-Teller (BET) and Fourier Transform Infrared (FT-IR) spectroscopy. The results show that the current density has a great effect on the morphology of the samples. The average size of the particles decreases as the applied current density increases and the average size of the samples decreases from 50 to 15 nm when the current density increases from 2 to 5 mA cm-2.

Synthesis of Gd2O3:Ho3+/Yb3+ upconversion nanoparticles for latent fingermark detection on difficult surfaces

NASA Astrophysics Data System (ADS)

Kumar, A.; Tiwari, S. P.; Singh, A. K.; Kumar, K.

2016-07-01

Infrared to visible upconversion fluorescent nanoparticles of Gd2O3 codoped with Ho3+/Yb3+ ions are synthesized via thermal decomposition process. The X-ray diffraction analysis of as-synthesized nanoparticles and annealed sample at 1000 °C has shown body-centered cubic phase of Gd2O3. The synthesized phosphor has shown intense green emission upon 980-nm excitation. High-contrast latent fingermarks on some difficult semi-porous and non-porous surfaces under 980-nm diode laser excitation were developed through powder dusting and colloidal solution spraying techniques and the results are compared with the commercial green luminescent fingermark powder. The latent fingermarks were developed on transparent (biological glass slides), single-color (aluminum foil) and multicolor (plywood, plastic bottle and book cover page) background surfaces. The present study depicts that the upconversion-based latent fingermarks detection using Gd2O3:Ho3+/Yb3+ phosphor material is suitable over the other conventional powders and has potential for practical applications in forensic science.

Synthesis, characterization and magnetic properties of MFe2O4 (M=Co, Mg, Mn, Ni) nanoparticles using ricin oil as capping agent

NASA Astrophysics Data System (ADS)

Gherca, Daniel; Pui, Aurel; Cornei, Nicoleta; Cojocariu, Alina; Nica, Valentin; Caltun, Ovidiu

2012-11-01

We focused on obtaining MFe2O4 nanoparticles using ricin oil solution as surfactant and on their structural characterization and magnetic properties. The annealed samples at 500 °C in air for 6 h were analyzed for the crystal phase identification by powder X-ray diffraction using CuKα radiation. The particle size, the chemical composition and the morphology of the calcinated powders were characterized by scanning electron microscopy. All sintered samples contain only one phase, which has a cubic structure with crystallite sizes of 12-21 nm. From the infrared spectra of all samples were observed two strong bands around 600 and 400 cm-1, which correspond to the intrinsic lattice vibrations of octahedral and tetrahedral sites of the spinel structure, respectively, and characteristic vibration for capping agent. The magnetic properties of fine powders were investigated at room temperature by using a vibrating sample magnetometer. The room temperature M-H hysteresis loops show ferromagnetic behavior of the calcined samples, with specific saturation magnetization (Ms) values ranging between 11 and 53 emu/g.

Effect of Heat Treatment Temperature on Chemical Compositions of Extracted Hydroxyapatite from Bovine Bone Ash

NASA Astrophysics Data System (ADS)

Younesi, M.; Javadpour, S.; Bahrololoom, M. E.

2011-11-01

This article presents the effect of heat treating temperature on chemical composition of hydroxyapatite (HA) that was produced by burning bovine bone, and then heat treating the obtained bone ash at different temperatures in range of 600-1100 °C in air. Bone ash and the resulting white powder from heat treating were characterized by Fourier transformed infrared spectroscopy (FT-IR) and x-ray diffractometry (XRD). The FT-IR spectra confirmed that heat treating of bone ash at temperature of 800 °C removed the total of organic substances. x-ray diffraction analysis showed that the white powder was HA and HA was the only crystalline phase indicated in heat treating product. x-ray fluorescence analyses revealed that calcium and phosphorous were the main elements and magnesium and sodium were minor impurities of produced powder at 800 °C. The results of the energy dispersive x-ray analysis showed that Ca/P ratio in produced HA varies in range of 1.46-2.01. The resulting material was found to be thermally stable up to 1100 °C.

Investigations on Cu2+-substituted Ni-Zn ferrite nanoparticles

NASA Astrophysics Data System (ADS)

Amarjeet; Kumar, Vinod

2016-11-01

CuxNi(1-x)/2Zn(1-x)/2Fe2O4 (x = 0.1, 0.3 and 0.5) nanoparticles were prepared by chemical co-precipitation method. The developed nanoparticles were characterized for structural properties by powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. Peak position in the X-ray diffraction pattern confirmed the single spinel phase of the developed particles. Infrared (IR) spectroscopy in mid-IR range showed the presence of characteristic absorption bands corresponding to octahedral and tetrahedral bonds in the spinel structure of prepared samples. Thermo-gravimetric analysis (TGA) measurements showed a considerable weight loss in the developed samples above 700∘C. Frequency dependence of the electrical properties of the developed material pellets was studied in the frequency range of 1 kHz-5 MHz. Temperature dependence of the dielectric constant of Cu0.1Ni0.45Zn0.45Fe2O4 was studied at different temperatures, i.e. at 425, 450 and 475 K, in the frequency range of 1 kHz-5 MHz. It was found that the electrical conductivity decreases with increasing Cu2+ ion content while it increases with the increase in temperature.

Application of focused-beam flat-sample method to synchrotron powder X-ray diffraction with anomalous scattering effect

NASA Astrophysics Data System (ADS)

Tanaka, M.; Katsuya, Y.; Matsushita, Y.

2013-03-01

The focused-beam flat-sample method (FFM), which is a method for high-resolution and rapid synchrotron X-ray powder diffraction measurements by combination of beam focusing optics, a flat shape sample and an area detector, was applied for diffraction experiments with anomalous scattering effect. The advantages of FFM for anomalous diffraction were absorption correction without approximation, rapid data collection by an area detector and good signal-to-noise ratio data by focusing optics. In the X-ray diffraction experiments of CoFe2O4 and Fe3O4 (By FFM) using X-rays near the Fe K absorption edge, the anomalous scattering effect between Fe/Co or Fe2+/Fe3+ can be clearly detected, due to the change of diffraction intensity. The change of observed diffraction intensity as the incident X-ray energy was consistent with the calculation. The FFM is expected to be a method for anomalous powder diffraction.

[Studies on the brand traceability of milk powder based on NIR spectroscopy technology].

PubMed

Guan, Xiao; Gu, Fang-Qing; Liu, Jing; Yang, Yong-Jian

2013-10-01

Brand traceability of several different kinds of milk powder was studied by combining near infrared spectroscopy diffuse reflectance mode with soft independent modeling of class analogy (SIMCA) in the present paper. The near infrared spectrum of 138 samples, including 54 Guangming milk powder samples, 43 Netherlands samples, and 33 Nestle samples and 8 Yili samples, were collected. After pretreatment of full spectrum data variables in training set, principal component analysis was performed, and the contribution rate of the cumulative variance of the first three principal components was about 99.07%. Milk powder principal component regression model based on SIMCA was established, and used to classify the milk powder samples in prediction sets. The results showed that the recognition rate of Guangming milk powder, Netherlands milk powder and Nestle milk powder was 78%, 75% and 100%, the rejection rate was 100%, 87%, and 88%, respectively. Therefore, the near infrared spectroscopy combined with SIMCA model can classify milk powder with high accuracy, and is a promising identification method of milk powder variety.

Expected values and variances of Bragg peak intensities measured in a nanocrystalline powder diffraction experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Öztürk, Hande; Noyan, I. Cevdet

A rigorous study of sampling and intensity statistics applicable for a powder diffraction experiment as a function of crystallite size is presented. Our analysis yields approximate equations for the expected value, variance and standard deviations for both the number of diffracting grains and the corresponding diffracted intensity for a given Bragg peak. The classical formalism published in 1948 by Alexander, Klug & Kummer [J. Appl. Phys.(1948),19, 742–753] appears as a special case, limited to large crystallite sizes, here. It is observed that both the Lorentz probability expression and the statistics equations used in the classical formalism are inapplicable for nanocrystallinemore » powder samples.« less

Expected values and variances of Bragg peak intensities measured in a nanocrystalline powder diffraction experiment

DOE PAGES

Öztürk, Hande; Noyan, I. Cevdet

2017-08-24

A rigorous study of sampling and intensity statistics applicable for a powder diffraction experiment as a function of crystallite size is presented. Our analysis yields approximate equations for the expected value, variance and standard deviations for both the number of diffracting grains and the corresponding diffracted intensity for a given Bragg peak. The classical formalism published in 1948 by Alexander, Klug & Kummer [J. Appl. Phys.(1948),19, 742–753] appears as a special case, limited to large crystallite sizes, here. It is observed that both the Lorentz probability expression and the statistics equations used in the classical formalism are inapplicable for nanocrystallinemore » powder samples.« less

Thermal analysis, X-ray powder diffraction and electron microscopy data related with the production of 1:1 Caffeine:Glutaric Acid cocrystals.

PubMed

Duarte, Íris; Andrade, Rita; Pinto, João F; Temtem, Márcio

2016-09-01

The data presented in this article are related to the production of 1:1 Caffeine:Glutaric Acid cocrystals as part of the research article entitled "Green production of cocrystals using a new solvent-free approach by spray congealing" (Duarte et al., 2016) [1]. More specifically, here we present the thermal analysis and the X-ray powder diffraction data for pure Glutaric Acid, used as a raw material in [1]. We also include the X-ray powder diffraction and electron microscopy data obtained for the 1:1 Caffeine:Glutaric Acid cocrystal (form II) produced using the cooling crystallization method reported in "Operating Regions in Cooling Cocrystallization of Caffeine and Glutaric Acid in Acetonitrile" (Yu et al., 2010) [2]. Lastly, we show the X-ray powder diffraction data obtained for assessing the purity of the 1:1 Caffeine:Glutaric cocrystals produced in [1].

Crystal structure, spectrum character and explosive property of a new cocrystal CL-20/DNT

NASA Astrophysics Data System (ADS)

Liu, Ke; Zhang, Gao; Luan, Jieyu; Chen, Zhiqun; Su, Pengfei; Shu, Yuanjie

2016-04-01

A new cocrystal explosive of 2,4,6,8,10,12-hexanitrohexaazaiso-wurtzitane(CL-20) and 2,5-dinitrotoluene(DNT) in a molar ratio of 1:2 has been prepared by slow solvent evaporation method. Crystal structure of the cocrystal characterized by single crystal X-ray diffraction (SXRD) reveals that the cocrystal is formed by intermolecular hydrogen bond interactions and belongs to the triclinic system with P-1 group. Moreover, the obivious differences of powder X-ray diffraction (PXRD) patterns, infrared spectroscopy and Raman spectroscopy confirm that the intermolecular interactions have great influence for the crystal structure and formation of cocrystal. The cocrystal exhibits a lower impact height of 44 cm, suggesting a substantial reduction of sensitivity in comparison with CL-20. And thermal test results showed cocrystal obtains a lower melting point than DNT, which means huge advantages in blasting engineering.

Syntheses, structure characterization and dissolution of two novel cocrystals of febuxostat

NASA Astrophysics Data System (ADS)

Kang, Yanlei; Gu, Jianming; Hu, Xiurong

2017-02-01

Febuxostat was investigated due to its significant effect in the treatment of gout. However, its poor water solubility hinder its potential applications. In recent years, cocrystals have increasingly being applied to enhance the drug solubility. To improve the solubility, two cocrystals of Febuxostat were synthesized through the method of cooling crystallization. The prepared cocrystals febuxostat-isonicotinamide(FEB-INA) and febuxostat-arginine(FEB-Arg) were studied by microscopical observation, Powder X-Ray Diffraction(PXRD), Single Crystal X-ray Diffraction, Differential Scanning Calorimetry(DSC), and infrared spectrometry. At the same time, the cocrystals' solubility and dissolution rate were explored. Both the cocrystals showed higher solubility compared to the pure drug. The FEB-Arg cocrystal enhanced about 900 times of solubility compared to the pure drug. The current study proved that cocrystallization can be a better way to enhance the solubility of the poorly water-soluble drug.

A novel coordination polymer of Ni(II) based on 1,3,5-benzenetricarboxylic acid synthesis, characterization, crystal structure, thermal study, and luminescent properties

NASA Astrophysics Data System (ADS)

Saheli, Sania; Rezvani, Alireza

2017-01-01

A new metal-organic framework (MOF) formulated as [Ni(H2btc)(OH)(H2O)2] (1) (H3btc = 1,3,5-benzenetricarboxylic acid) was synthesized using the hydrothermal technique. The complex 1 was characterized by elemental analysis, infrared spectroscopy, and powder X-ray diffraction in addition to single crystal X-ray diffraction. X-ray crystal structural analysis displayed that the compound belonged to the monoclinic space group P21/n with cell parameters a = 6.8658(14) Å, b = 18.849(4) Å, c = 8.5608(17) Å. In the title complex, ligand is linked to metal centers through two μ-oxo bridges and forming a 2D layer which is led to form an interesting geometry. The thermal stability and fluorescence property of 1 have also been investigated.

Synthesis of nanostructured vanadium powder by high-energy ball milling: X-ray diffraction and high-resolution electron microscopy characterization

NASA Astrophysics Data System (ADS)

Krishnan, Vinoadh Kumar; Sinnaeruvadi, Kumaran

2016-10-01

Vanadium metal powders, ball milled with different surfactants viz., stearic acid, KCl and NaCl, have been studied by X-ray diffraction and transmission electron microscopy. The surfactants alter the microstructural and morphological characteristics of the powders. Ball milling with stearic acid results in solid-state amorphization, while powders milled with KCl yield vanadium-tungsten carbide nanocomposite mixtures. NaCl proved to be an excellent surfactant for obtaining nanostructured fusion-grade vanadium powders. In order to understand the reaction mechanism behind any interstitial addition in the ball-milled powders, CHNOS analysis was performed.

Biocompatibility assessment of SiO2-TiO2 composite powder on MG63 osteoblast cell lines for orthopaedic applications.

PubMed

Chellappa, Maniickam; Thejaswini, Bezawada; Vijayalakshmi, Uthirapathy

2017-02-01

The objective of this study is to evaluate the biocompatibility of composite powder consisting of silica and titania (SiO 2 -TiO 2 ) for biomedical applications. The advancement of nanoscience and nanotechnology encourages researchers to actively participate in reinvention of existing materials with improved physical, chemical and biological properties. Hence, a composite/hybrid material has given birth of new materials with intriguing properties. In the present investigation, SiO 2 -TiO 2 composite powder was synthesised by sol-gel method and the prepared nanocomposite was characterised for its phase purity, functional groups, surface topography by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy. Furthermore, to understand the adverse effects of composite, biocompatibility test was analysed by cell culture method using MG63 osteoblast cell lines as a basic screening method. From the results, it was observed that typical Si-O-Ti peaks in FT-IR confirms the formation of composite and the crystallinity of the composite powder was analysed by XRD analysis. Further in vitro biocompatibility and acridine orange results have indicated better biocompatibility at different concentrations on osteoblast cell lines. On the basis of these observations, we envision that the prepared silica-titania nanocomposite is an intriguing biomaterial for better biomedical applications.

Optical properties of hydroxyapatite obtained by mechanical alloying

NASA Astrophysics Data System (ADS)

Silva, C. C.; Thomazini, D.; Pinheiro, A. G.; Lanciotti, F.; Sasaki, J. M.; Góes, J. C.; Sombra, A. S. B.

2002-09-01

Calcium phosphate based bioceramics, mainly in the form of hydroxyapatite (HA), have been in use in medicine and dentistry for the last 20 years. Applications include coatings of orthopaedic and dental implants, alveolar ridge augmentation, maxillofacial surgery, otolaryngology, and scaffolds for bone growth and as powders in total hip and knee surgery. These materials exhibit several problems of handling and fabrication, which can be overcome by mixing with a suitable binder. In this paper, mechanical alloying has been used successfully to produce nanocrystalline powders of HA using five different experimental procedures. The milled HA were studied by X-ray powder diffraction, infrared and Raman scattering spectroscopy. For four different procedures, HA was obtained after a couple of hours of milling (on an average, 20 h of milling depending on the reaction procedure). The XRD patterns indicate that the grain size is within the range of 29-103 nm. This milling process, used to produce HA, presents the advantage that melting is not necessary and the powder obtained is nanocrystalline with extraordinary mechanical properties. The material can be compacted and transformed in solid ceramic samples. The high efficiency of the process opens a way to produce commercial amount of nanocrystalline HA. Due to the nanocrystalline character of this powder, their mechanical properties have changed and for this reason a pressure of 1 GPa is enough to shape the sample into any geometry.

Quantitative assessment of copper proteinates used as animal feed additives using ATR-FTIR spectroscopy and powder X-ray diffraction (PXRD) analysis.

PubMed

Cantwell, Caoimhe A; Byrne, Laurann A; Connolly, Cathal D; Hynes, Michael J; McArdle, Patrick; Murphy, Richard A

2017-08-01

The aim of the present work was to establish a reliable analytical method to determine the degree of complexation in commercial metal proteinates used as feed additives in the solid state. Two complementary techniques were developed. Firstly, a quantitative attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopic method investigated modifications in vibrational absorption bands of the ligand on complex formation. Secondly, a powder X-ray diffraction (PXRD) method to quantify the amount of crystalline material in the proteinate product was developed. These methods were developed in tandem and cross-validated with each other. Multivariate analysis (MVA) was used to develop validated calibration and prediction models. The FTIR and PXRD calibrations showed excellent linearity (R 2  > 0.99). The diagnostic model parameters showed that the FTIR and PXRD methods were robust with a root mean square error of calibration RMSEC ≤3.39% and a root mean square error of prediction RMSEP ≤7.17% respectively. Comparative statistics show excellent agreement between the MVA packages assessed and between the FTIR and PXRD methods. The methods can be used to determine the degree of complexation in complexes of both protein hydrolysates and pure amino acids.

Chemical and Thermal Analysis

NASA Technical Reports Server (NTRS)

Bulluck, J. W.; Rushing, R. A.

1997-01-01

Work during the past three years has included significant research in several areas aimed at further clarification of the aging and chemical failure mechanism of thermoplastics (PVDF or Tefzel) for pipes. Among the areas investigated were the crystallinity changes associated with both the Coflon and Tefzel after various simulated environmental exposures using X-Ray diffraction analysis. We have found that significant changes in polymer crystallinity levels occur as a function of the exposures. These crystallinity changes may have important consequences on the fracture, fatigue, tensile, and chemical resistance of the materials. We have also noted changes in the molecular weight distribution and the increased crosslinking of the Coflon material using Gel Permeation Chromatographic Analysis. Again these changes may result in variations in the mechanical and chemical properties in the material. We conducted numerous analytical studies with methods including X-ray Diffraction, Gel Permeation Chromatography, Fourier Transform Infrared Spectroscopy, and Differential Scanning Calorimetry. We investigated a plethora of aged samples of both Tefzel and Coflon that were forwarded from MERL. Pressurized tests were performed on powdered PVDF in a modified Fluid A, which we will call A-2. In this case the ethylene diamine concentration was increased to 3 percent in methanol. Coflon pipe sections and powdered Coflon were exposed in pressure cells at 1700 psi at three separate test temperatures.

Sequential changes of main components in different kinds of milk powders using two-dimensional infrared correlation analysis

NASA Astrophysics Data System (ADS)

Zhou, Qun; Sun, Su-Qin; Yu, Lu; Xu, Chang-Hua; Noda, Isao; Zhang, Xin-Rong

2006-11-01

Infrared (IR) spectroscopy and two-dimensional (2D) correlation IR spectroscopy are shown to offer some information about stability and shelf life of milk powders without separation and extraction of individual components in this paper. Temperature has been chosen as the perturbation to monitor the infrared behavior of various milk powders, namely, whole milk powder (WMP), sweet whole milk powder (Sweet WMP), low-fat milk powder (LFMP), and skim milk powder (SMP). The sequential order of changes in protein, fat and carbohydrates (mainly lactose) in milk powders is studied for the first time. The protein changes before the sucrose in WMP, whereas the sucrose changes before the protein in Sweet WMP under temperature perturbation. It is also found that in SMP, carbohydrate changes prior to protein whereas in LFMP and WMP protein changes first as the temperature is increased. The conclusion can provide some useful reference to understand the thermal stability of milk powders.

Sucrose lyophiles: a semi-quantitative study of residual water content by total X-ray diffraction analysis.

PubMed

Bates, S; Jonaitis, D; Nail, S

2013-10-01

Total X-ray Powder Diffraction Analysis (TXRPD) using transmission geometry was able to observe significant variance in measured powder patterns for sucrose lyophilizates with differing residual water contents. Integrated diffraction intensity corresponding to the observed variances was found to be linearly correlated to residual water content as measured by an independent technique. The observed variance was concentrated in two distinct regions of the lyophilizate powder pattern, corresponding to the characteristic sucrose matrix double halo and the high angle diffuse region normally associated with free-water. Full pattern fitting of the lyophilizate powder patterns suggested that the high angle variance was better described by the characteristic diffraction profile of a concentrated sucrose/water system rather than by the free-water diffraction profile. This suggests that the residual water in the sucrose lyophilizates is intimately mixed at the molecular level with sucrose molecules forming a liquid/solid solution. The bound nature of the residual water and its impact on the sucrose matrix gives an enhanced diffraction response between 3.0 and 3.5 beyond that expected for free-water. The enhanced diffraction response allows semi-quantitative analysis of residual water contents within the studied sucrose lyophilizates to levels below 1% by weight. Copyright © 2013 Elsevier B.V. All rights reserved.

Potential of Sm3+ doped LiSrVO4 nanophosphor to fill amber gap in LEDs

NASA Astrophysics Data System (ADS)

Biswas, P.; Kumar, Vinay; Sharma, Vishal; Bedyal, A. K.; Padha, Naresh; Swart, H. C.

2018-04-01

The LiSrVO4:Sm3+ phosphor powders were synthesized by the combustion method by varying the concentration of the Sm3+ ions from 0.25 mol% to 2.5 mol%. The powder X-ray diffraction (XRD) studies confirmed that the phosphors were crystallized as monoclinic structure belonging to space group P2/m and the transmission electron microscopy (TEM) revealed nanosized grains of the powders. The Fourier transform infrared studies (FTIR) established the formation of non-hygroscopic vanadate powders. The photoluminescence (PL) and diffused reflectance studies (DRS) were also carried out and discussed. Under 401 nm excitation, the optimized phosphor exhibited the characteristic 568, 600, 646 and 704 nm emissions of Sm3+ which corresponded to the orange-red (amber) color with (0.59, 0.41) Commission Internationale de' Eclairage (CIE) chromaticity coordinates. Concentration quenching of phosphor intensity on account of non-radiative energy transfer was ascribed to dipole-dipole interaction between activators. DRS study reveals that the host of the phosphor is a wide bandgap material which accommodates the dopant successfully. The present results signify that the LiSrVO4:Sm3+ phosphor can suitably be excited by the GaN family of UV-LEDs chips for efficient amber LEDs applications.

Bioactivity and mineralization of natural hydroxyapatite from cuttlefish bone and Bioglass® co-sintered bioceramics.

PubMed

Cozza, Natascia; Monte, Felipe; Bonani, Walter; Aswath, Pranesh; Motta, Antonella; Migliaresi, Claudio

2018-02-01

In this study, bioactive hydroxyapatite (HAP)-based bioceramics starting from cuttlefish bone powders have been prepared and characterized. In particular, fragmented cuttlefish bone was co-sintered with 30 wt% of Bioglass ® -45S5 to synthesize HAP-based powders with enhanced mechanical properties and bioactivity. Commercial synthetic HAP was treated following the same procedure and used as a reference. The structure and composition of the bioceramics formulations were characterized using Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. After the thermal treatment of cuttlefish bone powder added with 30 wt% Bioglass, new phases with compositions of sodium calcium phosphate [Na 3 Ca 6 (PO 4 ) 5 ], β-tricalcium phosphate [Ca 3 (PO 4 )] and amorphous silica were detected. In vitro cell culture studies were performed by evaluating proliferation, metabolic activity and differentiation of human osteoblast-like cells (MG63). Scaffolds made with cuttlefish bone powder exhibited increased apatite deposition, alkaline phosphatase activity and cell proliferation compared with commercial synthetic HAP. In addition, the ceramic compositions obtained after the combination with Bioglass ® further enhanced the metabolic activity of MG63 cell and promoted the formation of a well-developed apatite layer after 7 days of incubation in Dulbecco's modified Eagle's medium. Copyright © 2017 John Wiley & Sons, Ltd.

Synthesis of fluorapatite–hydroxyapatite nanoparticles and toxicity investigations

PubMed Central

Montazeri, N; Jahandideh, R; Biazar, Esmaeil

2011-01-01

In this study, calcium phosphate nanoparticles with two phases, fluorapatite (FA; Ca10(PO4)6F2) and hydroxyapatite (HA; Ca10(PO4)6(OH)2), were prepared using the solgel method. Ethyl phosphate, hydrated calcium nitrate, and ammonium fluoride were used, respectively, as P, Ca, and F precursors with a Ca:P ratio of 1:72. Powders obtained from the sol-gel process were studied after they were dried at 80°C and heat treated at 550°C. The degree of crystallinity, particle and crystallite size, powder morphology, chemical structure, and phase analysis were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Zetasizer experiments. The results of XRD analysis and FTIR showed the presence of hydroxyapatite and fluorapatite phases. The sizes of the crystallites estimated from XRD patterns using the Scherrer equation and the crystallinity of the hydroxyapatite phase were about 20 nm and 70%, respectively. Transmission electron microscope and SEM images and Zetasizer experiments showed an average size of 100 nm. The in vitro behavior of powder was investigated with mouse fibroblast cells. The results of these experiments indicated that the powders were biocompatibile and would not cause toxic reactions. These compounds could be applied for hard-tissue engineering. PMID:21499417

Pressure-induced polymerization of P(CN) 3

DOE PAGES

Gou, Huiyang; Yonke, Brendan L.; Epshteyn, Albert; ...

2015-05-21

Motivated to explore the formation of novel extended carbon-nitrogen solids via well-defined molecular precursor pathways, we studied the chemical reactivity of highly pure phosphorous tricyanide, P(CN) 3, under conditions of high pressure at room temperature. Raman and infrared (IR) spectroscopic measurements reveal a series of phase transformations below 10 GPa, and several low-frequency vibrational modes are reported for the first time. Synchrotron powder Xray diffraction (PXRD) measurements taken during compression show that molecular P(CN) 3 is highly compressible with a bulk modulus of 10.0±0.3 GPa and polymerizes into an amorphous solid above ~10.0 GPa. Raman and infrared (IR) spectra, togethermore » with first-principles molecular-dynamics simulations, show that the amorphization transition is associated with polymerization of the cyanide groups into CN bonds with predominantly sp 2 character, similar to known carbon nitrides, resulting in a novel PCN polymeric phase, which is recoverable to ambient pressure.« less

Monetite formed in mixed solvents of water and ethylene glycol and its transformation to hydroxyapatite.

PubMed

Ma, Ming-Guo; Zhu, Ying-Jie; Chang, Jiang

2006-07-27

Agglomerated nanorods of hydroxyapatite have been synthesized using monetite as a precursor in a NaOH solution. Monetite consisting of nanosheets has been successfully synthesized by a one-step microwave-assisted method using CaCl(2).2.5H(2)O, NaH(2)PO(4), and sodium dodecyl sulfate (SDS) in water/ethylene glycol (EG) mixed solvents. The effects of the molar ratio of water to EG and the reaction time on the products were investigated. The products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectrometry (FTIR).

Synthesis, crystal growth, structural, thermal and optical properties of naphthalene picrate an organic NLO material.

PubMed

Chandramohan, A; Bharathikannan, R; Kandavelu, V; Chandrasekaran, J; Kandhaswamy, M A

2008-12-01

Crystalline substance of naphthalene picrate (NP) was synthesized and single crystals were grown using slow evaporation solution growth technique. The solubility of the naphthalene picrate complex was estimated using different solvents such as chloroform and benzene. The material was characterized by elemental analysis, powder X-ray diffraction (XRD), nuclear magnetic resonance (NMR) and fourier transform-infrared (FT-IR) techniques. The electronic absorption was studied through UV-vis spectrophotometer. Thermal behavior and stability of the crystal were studied using thermogravimetric (TG) and differential thermal analysis (DTA) techniques. The second harmonic generation (SHG) of the material was confirmed using Nd:YAG laser.

Characterization of mineral coatings associated with a Pleistocene-Holocene rock art style: The Northern Running Figures of the East Alligator River region, western Arnhem Land, Australia.

PubMed

King, Penelope L; Troitzsch, Ulrike; Jones, Tristen

2017-02-01

This data article contains mineralogic and chemical data from mineral coatings associated with rock art from the East Alligator River region. The coatings were collected adjacent to a rock art style known as the "Northern Running Figures" for the purposes of radiocarbon dating (doi:10.1016/j.jasrep.2016.11.016; (T. Jones, V. Levchenko, P.L. King, U. Troitzsch, D. Wesley, 2017) [1]). This contribution includes raw and processed powder X-ray Diffraction data, Scanning Electron Microscopy energy dispersive spectroscopy data, and Fourier Transform infrared spectral data.

In vitro cytotoxicity and quantitative silica analysis of diatomaceous earth products.

PubMed

Bye, E; Davies, R; Griffiths, D M; Gylseth, B; Moncrieff, C B

1984-05-01

Mouse peritoneal macrophages were used to evaluate the relative cytotoxicity of a series of diatomaceous earth products in vitro. The amorphous and crystalline silica content of the products was determined by a combination of infrared spectroscopy and x ray powder diffraction techniques. The cytotoxicities of the high cristobalite content flux calcined materials were similar to that of the standard cristobalite ; both the natural and straight calcined materials had significantly greater activities than the flux calcined materials. Thus within the limitations of the macrophage cytotoxicity test the hypothesis that crystalline content is the only determinant of fibrogenicity of diatomaceous earth is not supported.

In vitro cytotoxicity and quantitative silica analysis of diatomaceous earth products.

PubMed Central

Bye, E; Davies, R; Griffiths, D M; Gylseth, B; Moncrieff, C B

1984-01-01

Mouse peritoneal macrophages were used to evaluate the relative cytotoxicity of a series of diatomaceous earth products in vitro. The amorphous and crystalline silica content of the products was determined by a combination of infrared spectroscopy and x ray powder diffraction techniques. The cytotoxicities of the high cristobalite content flux calcined materials were similar to that of the standard cristobalite ; both the natural and straight calcined materials had significantly greater activities than the flux calcined materials. Thus within the limitations of the macrophage cytotoxicity test the hypothesis that crystalline content is the only determinant of fibrogenicity of diatomaceous earth is not supported. Images PMID:6326795

Microwave assisted combustion synthesis of nanocrystalline CoFe2O4 for LPG sensing

NASA Astrophysics Data System (ADS)

Chaudhari, Prashant; Acharya, S. A.; Darunkar, S. S.; Gaikwad, V. M.

2015-08-01

A microwave-assisted citrate precursor method has been utilized for synthesis of nanocrystalline powders of CoFe2O4. The process takes only a few minutes to obtain as-synthesized CoFe2O4. Structural properties of the synthesized material were investigated by X-ray diffraction; scanning electron microscopy, Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy. The gas sensing properties of thick film of CoFe2O4 prepared by screen printing towards Liquid Petroleum Gas (LPG) revealed that CoFe2O4 thick films are sensitive and shows maximum sensitivity at 350°C for 2500 ppm of LPG.

Analysis of Short and Long Range Atomic Order in Nanocrystalline Diamonds with Application of Powder Diffractometry

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Neuefiend, J.; Weber, H.-P.; Proffen, T.; VonDreele, R.; Palosz, W.;

A New Camera for Powder Diffraction of Macromolecular Crystallography at SPring-8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miura, Keiko; Inoue, Katsuaki; Goto, Shunji

2004-05-12

A powder diffractometer of Guinier geometry was developed and tested on a beamline, BL40B2, at SPring-8. The long specimen-to-detector distance, 1,000 mm, is advantageous in recording diffraction from Bragg spacing of 20 nm or larger. The angular resolution, 0.012 degrees, was realized together with the focusing optics, the long specimen-to-detector distance and the small pixel size of Blue-type Imaging Plate detector. Such a high resolution makes the peak separation possible in the powder diffraction from microcrystals with large unit cell and low symmetry of biological macromolecules.

Energy research with neutrons (ErwiN) and installation of a fast neutron powder diffraction option at the MLZ, Germany1

PubMed Central

Mühlbauer, Martin J.

2018-01-01

The need for rapid data collection and studies of small sample volumes in the range of cubic millimetres are the main driving forces for the concept of a new high-throughput monochromatic diffraction instrument at the Heinz Maier-Leibnitz Zentrum (MLZ), Germany. A large region of reciprocal space will be accessed by a detector with sufficient dynamic range and microsecond time resolution, while allowing for a variety of complementary sample environments. The medium-resolution neutron powder diffraction option for ‘energy research with neutrons’ (ErwiN) at the high-flux FRM II neutron source at the MLZ is foreseen to meet future demand. ErwiN will address studies of energy-related systems and materials with respect to their structure and uniformity by means of bulk and spatially resolved neutron powder diffraction. A set of experimental options will be implemented, enabling time-resolved studies, rapid parametric measurements as a function of external parameters and studies of small samples using an adapted radial collimator. The proposed powder diffraction option ErwiN will bridge the gap in functionality between the high-resolution powder diffractometer SPODI and the time-of-flight diffractometers POWTEX and SAPHiR at the MLZ. PMID:29896055

Effect of multiple circular holes Fraunhofer diffraction for the infrared optical imaging

NASA Astrophysics Data System (ADS)

Lu, Chunlian; Lv, He; Cao, Yang; Cai, Zhisong; Tan, Xiaojun

2014-11-01

With the development of infrared optics, infrared optical imaging systems play an increasingly important role in modern optical imaging systems. Infrared optical imaging is used in industry, agriculture, medical, military and transportation. But in terms of infrared optical imaging systems which are exposed for a long time, some contaminations will affect the infrared optical imaging. When the contamination contaminate on the lens surface of the optical system, it would affect diffraction. The lens can be seen as complementary multiple circular holes screen happen Fraunhofer diffraction. According to Babinet principle, you can get the diffraction of the imaging system. Therefore, by studying the multiple circular holes Fraunhofer diffraction, conclusions can be drawn about the effect of infrared imaging. This paper mainly studies the effect of multiple circular holes Fraunhofer diffraction for the optical imaging. Firstly, we introduce the theory of Fraunhofer diffraction and Point Spread Function. Point Spread Function is a basic tool to evaluate the image quality of the optical system. Fraunhofer diffraction will affect Point Spread Function. Then, the results of multiple circular holes Fraunhofer diffraction are given for different hole size and hole spacing. We choose the hole size from 0.1mm to 1mm and hole spacing from 0.3mm to 0.8mm. The infrared wavebands of optical imaging are chosen from 1μm to 5μm. We use the MATLAB to simulate light intensity distribution of multiple circular holes Fraunhofer diffraction. Finally, three-dimensional diffraction maps of light intensity are given to contrast.

Microporous Cd(II) metal-organic framework as fluorescent sensor for nitroaromatic explosives at the sub-ppm level

NASA Astrophysics Data System (ADS)

Wang, Xing-Po; Han, Lu-Lu; Wang, Zhi; Guo, Ling-Yu; Sun, Di

2016-03-01

A novel Cd(II) metal-organic framework (MOF) based on a rigid biphenyltetracarboxylic acid, [Cd4(bptc)2(DMA)4(H2O)2·4DMA] (1) was successfully synthesized under the solvothermal condition and characterized by single-crystal X-ray diffraction and further consolidated by elemental analyses, powder X-ray diffraction (PXRD), infrared spectra (IR) and luminescent measurements. Single crystal X-ray diffraction analysis reveals that compound 1 is 4-connected PtS (Point symbol: {42·84}) network based on [Cd2(COO)4] secondary building units (SBUs). Its inherent porous and emissive characteristics make them to be a suitable fluorescent probe to sense small solvents and nitroaromatic explosives. Compound 1 shows obviously solvent-dependent emissive behaviors, especially for acetone with very high fluorescence quenching effect. Moreover, compound 1 displays excellent sensing of nitroaromatic explosives at sub-ppm level, giving a detection limit of 0.43 ppm and 0.37 ppm for nitrobenzene (NB) and p-nitrotoluene (PNT), respectively. This shows this Cd(II) MOF can be used as fluorescence probe for the detection of nitroaromatic explosives.

Sodium Hydroxide Activated Nanoporous Carbons Based on Lapsi Seed Stone.

PubMed

Joshi, Sahira; Shrestha, Lok Kumar; Kamachi, Yuichiro; Yamauchi, Yusuke; Pradhananga, Mandira Adhikari; Pokhrel, Bhadra Prasad; Ariga, Katsuhiko; Pradhananga, Raja Ram

2015-02-01

Nanoporous activated carbons (ACs) were prepared from Lapsi (Choerospondias axillaris) seed powder by chemical activation with sodium hydroxide (NaOH) at different NaOH impregnation ratios. The prepared ACs were characterized by Fourier transform-infrared (FTIR) spectroscopy, Raman scattering, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Semi-quantitative information on the surface properties was obtained by estimating iodine number. FTIR spectra showed the presence of oxygenated functional groups such as hydroxyl, carbonyl, and carboxyl in the prepared ACs. Raman scattering showed clear D and G bands in the spectra. The intensity ratio of G and D band peak intensity was ca. 1.39 at lowest NaOH and Lapsi seed powder ratio 0.25:1 showing high graphitic degree. This ratio decreased with increase in the NaOH impregnation ratio and reached minimum ca. 0.94 (comparable with commercial AC) at NaOH and Lapsi seed powder ratio 1:1 demonstrating that higher NaOH impregnation reduces the graphitic structure of the carbon. XRD patterns showed two broad peaks at diffraction angles of approximately 25 and 43 degrees indicating the amorphous structure. Surface properties of the ACs (BET surface area, pore volume, and pore size distributions) were evaluated by nitrogen adsorption-desorption isotherm. Our ACs showed strong methylene blue adsorption property (maximum methylene blue is ca. 200 mg/g). Judging from the iodine number and methylene blue values, structure, and surface areas, it can be concluded that NaOH impregnation ratio is one of the key parameters to tune the surface properties of Lapsi seed stone-based activated carbons.

Structure determination of two structural analogs, named 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-fluorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C23H16F2N4S) and 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-chlorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C23H16ClFN4S) by synchrotron X-ray powder diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gündoğdu, Gülsüm; Aytaç, Sevim Peri; Müller, Melanie

Two novel compounds, 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-fluorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C 23H 16F 2N 4S) (1) and 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-chlorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C 23H 16ClFN 4S) (2), have been designed and synthesized as cytotoxic agents. The compounds were characterized by infrared, proton nuclear magnetic resonance, mass spectral data, elemental analysis and X-ray powder diffraction. The present study comprises spectral data and crystal structures of these novel compounds determined from synchrotron X-ray powder diffraction data. The structure solutions were obtained by simulated annealing. The final structures were achieved by Rietveld refinement using soft restraints for all bond lengths, bond angles, and planar groups. Both compounds crystallize in space groupmore » $$P\\bar 1$$,Z= 2, with the unit-cell parametersa= 6.37433(9),b= 11.3641(2),c= 14.09115(19) Å,α= 80.1740(8)°,β= 85.1164(8)°,γ= 80.9831(10)°,V= 991.55(3) Å 3of compound (1) anda= 6.53736(6),b= 11.55725(15),c= 14.01373(13) Å,α= 80.3323(7)°,β= 84.8939(6)°,γ= 79.3954(8)°,V= 1024.08(2) Å 3of compound (2). Structural analyses reveal that the title compounds are isostructural.« less

Influence of thermal treatment on the formation of zirconia nanostructured powder by thermal decomposition of different precursors

NASA Astrophysics Data System (ADS)

Stoia, Marcela; Barvinschi, Paul; Barbu-Tudoran, Lucian; Negrea, Adina; Barvinschi, Floricica

2013-10-01

The paper presents some results concerning the preparation of zirconia powders starting from ZrOCl2·8H2O by using two synthesis methods: (a) precipitation with NH3, at 90 °C, and (b) thermal decomposition of carboxylate precursors, obtained in the reaction of zirconium nitrate and two different alcohols, 1,3-propanediol (PD) and poly(vinyl alcohol) (PVA), at 150 °C. The precursors obtained at different temperatures have been characterized by thermal analysis (TG, DTA) and FT-IR spectroscopy. DTA analysis evidenced very clearly the transition temperatures between zirconia crystalline phases. The precursors have been annealed at different temperatures in order to obtain zirconia powders and the as obtained powders have been characterized by means of X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). In case of precipitation method the presence of the tetragonal phase was observed at 400 °C, while the monoclinic phase appears at temperatures higher than 400 °C, becoming major crystalline phase starting with 700 °C. In case of the powders prepared by thermal decomposition of carboxylate precursors, the tetragonal phase was formed at temperatures below 700 °C, when the monoclinic phase begin to crystallize as secondary phase, in a higher proportion for the samples synthesized with 1,3-propanediol. All powders annealed at 1200 °C are pure monoclinic zirconia. SEM images have evidenced for the zirconia powders annealed at 1000 °C particles with diameters up to 150 nm, agglomerated in micrometer-sized aggregates, more individualized and homogenous than that obtained in the case of zirconia powder synthesized with poly(vinyl alcohol).

High-resolution neutron diffraction study of microstructural changes in nanocrystalline ball-milled niobium carbide NbC{sub 0.93}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balagurov, Anatoly M.; Bobrikov, Ivan A.; Bokuchava, Gizo D.

2015-11-15

High resolution neutron diffraction was applied for elucidating of the microstructural evolution of nanocrystalline niobium carbide NbC{sub 0.93} powders subjected to high-energy ball milling. The diffraction patterns were collected with the high resolution Fourier diffractometer HRFD by using the reverse time-of-flight (RTOF) mode of data acquisition. The traditional single diffraction line analysis, the Rietveld method and more advanced Whole Powder Pattern Modeling technique were applied for the data analysis. The comparison of these techniques was performed. It is established that short-time milling produces a non-uniform powder, in which two distinct fractions with differing microstructure can be identified. Part of themore » material is in fact milled efficiently, with a reduction in grain size, an increase in the quantity of defects, and a corresponding tendency to decarburize reaching a composition NbC{sub 0.80} after 15 h of milling. The rest of the powder is less efficiently processed and preserves its composition and lower defect content. Larger milling times should have homogenized the system by increasing the efficiently milled fraction, but the material is unable to reach a uniform and homogeneous state. It is definitely shown that RTOF neutron diffraction patterns can provide the very accurate data for microstructure analysis of nanocrystalline powders. - Highlights: • The NbC{sub 0.93} powder was processed by high-energy ball milling. • The microstrain and dislocation density increase with milling time increase. • The corresponding decrease in crystallite size with milling time was observed. • The material exhibits the presence of two fractions after ball milling. • The RTOF neutron diffraction data are suitable for accurate microstructure analysis.« less

Digital Image Correlation of 2D X-ray Powder Diffraction Data for Lattice Strain Evaluation

PubMed Central

Zhang, Hongjia; Sui, Tan; Daisenberger, Dominik; Fong, Kai Soon

2018-01-01

High energy 2D X-ray powder diffraction experiments are widely used for lattice strain measurement. The 2D to 1D conversion of diffraction patterns is a necessary step used to prepare the data for full pattern refinement, but is inefficient when only peak centre position information is required for lattice strain evaluation. The multi-step conversion process is likely to lead to increased errors associated with the ‘caking’ (radial binning) or fitting procedures. A new method is proposed here that relies on direct Digital Image Correlation analysis of 2D X-ray powder diffraction patterns (XRD-DIC, for short). As an example of using XRD-DIC, residual strain values along the central line in a Mg AZ31B alloy bar after 3-point bending are calculated by using both XRD-DIC and the conventional ‘caking’ with fitting procedures. Comparison of the results for strain values in different azimuthal angles demonstrates excellent agreement between the two methods. The principal strains and directions are calculated using multiple direction strain data, leading to full in-plane strain evaluation. It is therefore concluded that XRD-DIC provides a reliable and robust method for strain evaluation from 2D powder diffraction data. The XRD-DIC approach simplifies the analysis process by skipping 2D to 1D conversion, and opens new possibilities for robust 2D powder diffraction data analysis for full in-plane strain evaluation. PMID:29543728

Structure determination of Ba5AlF13 by coupling electron, synchrotron and neutron powder diffraction, solid-state NMR and ab initio calculations.

PubMed

Martineau, Charlotte; Allix, Mathieu; Suchomel, Matthew R; Porcher, Florence; Vivet, François; Legein, Christophe; Body, Monique; Massiot, Dominique; Taulelle, Francis; Fayon, Franck

2016-10-04

The room temperature structure of Ba 5 AlF 13 has been investigated by coupling electron, synchrotron and neutron powder diffraction, solid-state high-resolution NMR ( 19 F and 27 Al) and first principles calculations. An initial structural model has been obtained from electron and synchrotron powder diffraction data, and its main features have been confirmed by one- and two-dimensional NMR measurements. However, DFT GIPAW calculations of the 19 F isotropic shieldings revealed an inaccurate location of one fluorine site (F3, site 8a), which exhibited unusual long F-Ba distances. The atomic arrangement was reinvestigated using neutron powder diffraction data. Subsequent Fourier maps showed that this fluorine atom occupies a crystallographic site of lower symmetry (32e) with partial occupancy (25%). GIPAW computations of the NMR parameters validate the refined structural model, ruling out the presence of local static disorder and indicating that the partial occupancy of this F site reflects a local motional process. Visualisation of the dynamic process was then obtained from the Rietveld refinement of neutron diffraction data using an anharmonic description of the displacement parameters to account for the thermal motion of the mobile fluorine. The whole ensemble of powder diffraction and NMR data, coupled with first principles calculations, allowed drawing an accurate structural model of Ba 5 AlF 13 , including site-specific dynamical disorder in the fluorine sub-network.

A new theory for X-ray diffraction.

PubMed

Fewster, Paul F

2014-05-01

This article proposes a new theory of X-ray scattering that has particular relevance to powder diffraction. The underlying concept of this theory is that the scattering from a crystal or crystallite is distributed throughout space: this leads to the effect that enhanced scatter can be observed at the `Bragg position' even if the `Bragg condition' is not satisfied. The scatter from a single crystal or crystallite, in any fixed orientation, has the fascinating property of contributing simultaneously to many `Bragg positions'. It also explains why diffraction peaks are obtained from samples with very few crystallites, which cannot be explained with the conventional theory. The intensity ratios for an Si powder sample are predicted with greater accuracy and the temperature factors are more realistic. Another consequence is that this new theory predicts a reliability in the intensity measurements which agrees much more closely with experimental observations compared to conventional theory that is based on `Bragg-type' scatter. The role of dynamical effects (extinction etc.) is discussed and how they are suppressed with diffuse scattering. An alternative explanation for the Lorentz factor is presented that is more general and based on the capture volume in diffraction space. This theory, when applied to the scattering from powders, will evaluate the full scattering profile, including peak widths and the `background'. The theory should provide an increased understanding of the reliability of powder diffraction measurements, and may also have wider implications for the analysis of powder diffraction data, by increasing the accuracy of intensities predicted from structural models.

Study on the infrared radiation performance of Tourmaline composite and its effect on the diesel characteristic

NASA Astrophysics Data System (ADS)

Liao, Jian Bin; Yu, Hong Liang; Sun, Di; Ma, Fong Yuan

2017-09-01

The black tourmaline, magnesium tourmaline, and spinel were ground into powder, and the infrared radiation material was prepared by adding the ceramic powder, clay and the other material into the tourmaline powder according to a certain proportion. The infrared radiation property was tested and analyzed, the diesel was infrared radiation activated by the composite material, and the physicochemical property of fuel oil was analyzed pre-test and post-test. The result shows that the infrared absorption spectrum of the black tourmaline of different particle size is stable. After the diesel oil was infrared radiation activated by tourmaline composite materials, the physicochemical property of diesel oil was changed, the activation energy decreased, the viscosity and surface tension of fuel oil were reduced.

Evidence from x-ray and neutron powder diffraction patterns that the so-called icosahedral and decagonal quasicrystals of MnAl(6) and other alloys are twinned cubic crystals.

PubMed

Pauling, L

1987-06-01

It is shown that the x-ray powder diffraction patterns of rapidly quenched MnAl(6) and Mg(32)(Al,Zn)(49) and the neutron powder diffraction pattern of MnAl(6) are compatible with the proposed 820-atom primitive cubic structure [Pauling, L. (1987) Phys. Rev. Lett. 58, 365-368]. The values found for the edge of the unit cube are 23.365 A (x-ray) and 23.416 A (neutron) for MnAl(6) and 24.313 A (x-ray) for Mg(32)(Al,Zn)(49).

Evidence from x-ray and neutron powder diffraction patterns that the so-called icosahedral and decagonal quasicrystals of MnAl6 and other alloys are twinned cubic crystals

PubMed Central

Pauling, Linus

1987-01-01

It is shown that the x-ray powder diffraction patterns of rapidly quenched MnAl6 and Mg32(Al,Zn)49 and the neutron powder diffraction pattern of MnAl6 are compatible with the proposed 820-atom primitive cubic structure [Pauling, L. (1987) Phys. Rev. Lett. 58, 365-368]. The values found for the edge of the unit cube are 23.365 Å (x-ray) and 23.416 Å (neutron) for MnAl6 and 24.313 Å (x-ray) for Mg32(Al,Zn)49. PMID:16593841

New high- and low-temperature apparatus for synchrotron polycrystalline X-ray diffraction.

PubMed

Tang, C C; Bushnell-Wye, G; Cernik, R J

1998-05-01

A high-temperature furnace with an induction heater coil and a cryogenic system based on closed-cycle refrigeration have been assembled to enhance the non-ambient powder diffraction facilities at the Synchrotron Radiation Source, Daresbury Laboratory. The commissioning of the high- and low-temperature devices on the high-resolution powder diffractometer of Station 2.3 is described. The combined temperature range provided by the furnace/cryostat is 10-1500 K. Results from Fe and NH(4)Br powder samples are presented to demonstrate the operation of the apparatus. The developments presented in this paper are applicable to a wide range of other experiments and diffraction geometries.

Improved camera for better X-ray powder photographs

NASA Technical Reports Server (NTRS)

Parrish, W.; Vajda, I. E.

1969-01-01

Camera obtains powder-type photographs of single crystals or polycrystalline powder specimens. X-ray diffraction photographs of a powder specimen are characterized by improved resolution and greater intensity. A reasonably good powder pattern of small samples can be produced for identification purposes.

Solid state 13C-NMR, infrared, X-ray powder diffraction and differential thermal studies of the homologous series of some mono-valent metal (Li, Na, K, Ag) n-alkanoates: A comparative study

NASA Astrophysics Data System (ADS)

Nelson, Peter N.; Ellis, Henry A.; White, Nicole A. S.

2015-06-01

A comparative study of the molecular packing, lattice structures and phase behaviors of the homologous series of some mono-valent metal carboxylates (Li, Na, K and Ag) is carried out via solid state FT-infrared and 13C-NMR spectroscopes, X-rays powder diffraction, density measurements, differential scanning calorimetry, polarizing light microscopy and variable temperature infrared spectroscopy. It is proposed that, for lithium, sodium and potassium carboxylates, metal-carboxyl coordination is via asymmetric chelating bidentate bonding with extensive intermolecular interactions to form tetrahedral metal centers, irrespective of chain length. However, for silver n-alkanoates, carboxyl moieties are bound to silver ions via syn-syn type bridging bidentate coordination to form dimeric units held together by extensive head group inter-molecular interactions. Furthermore, the fully extended hydrocarbon chains which are crystallized in the all-trans conformation are tilted at ca. 30°, 27°, 15° and 31° with respect to a normal to the metal plane, for lithium, sodium, silver and potassium carboxylates, respectively. All compounds are packed as lamellar bilayer structures, however, lithium compounds are crystallized in a triclinic crystal system whilst silver, sodium and potassium n-alkanoates are all monoclinic with possible P1 bravais lattice. Odd-even alternation observed in various physical features is associated with different inter-planar spacing between closely packed layers in the bilayer which are not in the same plane; a phenomenon controlled by lattice packing symmetry requirements. All compounds, except silver carboxylates, show partially reversibly first order pre-melting transitions; the number of which increases with increasing chain length. These transitions are associated, for the most part, with lamellar collapse followed by increased gauche-trans isomerism in the methylene group assembly, irrespective of chain length. It is proposed that the absence of mesomorphic transitions in their phase sequences is due to a lack of sufficient balance between attractive and repulsive electrostatic and van der Waals forces during phase change. The evidence presented in this study shows that phase behaviors of mono-valent metal carboxylates are controlled, mainly, by head group bonding.

Synthesis of TiO2 nano-powders prepared from purified sulphate leach liquor of red mud.

PubMed

Tsakiridis, P E; Oustadakis, P; Katsiapi, A; Perraki, M; Agatzini-Leonardou, S

2011-10-30

The research work presented in this paper is focused on the development of a purification process of red mud sulphate leach liquor for the recovery of titanium oxide (TiO(2)) nano-powders in the form of anatase. Initially, titanium was extracted over iron and aluminium from the leach liquor by solvent extraction using Cyanex 272 in toluene, at pH: 0.3 and T: 25°C, with 40% extractant concentration. Stripping of the loaded, with titanium, organic phase was carried out by diluted HCl (3 mol/L) at ambient temperature. Finally, the recovery of titanium nano-powder, in the form of anatase, was performed by chemical precipitation at pH: 6 and T: 95°C, using 10 wt% MgO pulp as neutralizing agent. The produced precipitates were characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric/differential thermal analysis (TGA/DTA). Their morphological characteristics and microstructure were studied by scanning electron microscopy (SEM). High grade titanium white precipitate, in the form of anatase, was obtained. Iron concentration in the precipitate did not exceed 0.3%, whereas no aluminium was detected. Copyright © 2011 Elsevier B.V. All rights reserved.

Preparation and characterization of new photoluminescent nano-powder based on Eu3+:La2Ti2O7 and dispersed into silica matrix for latent fingerprint detection

NASA Astrophysics Data System (ADS)

Saif, M.; Alsayed, N.; Mbarek, A.; El-Kemary, M.; Abdel-Mottaleb, M. S. A.

2016-12-01

Pure lanthanum titanate doped with europium metal ions (La2Ti2O7:Eu3+) and dispersed in silica matrix phosphor powder was prepared by sol-gel process followed by thermal treatment. The prepared nanophosphors were characterized by powder X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR), Transmission Electron Microscope (TEM), Energy Dispersive Spectroscopy (EDX), and Photoluminescence Spectroscopy (PL). The effects of silica, thermal treatment, Eu3+ ion, and surfactant (CTAB) concentrations on the crystal, morphology, and photoluminescence properties were investigated. The present work found that dispersion of La2Ti2O7:Eu3+ into silica matrix significantly altered the morphology of La2Ti2O7:Eu3+ from high crystalline micro-plate like shape into amorphous aggregated Nano-spherical shape. The high separated spherical shape with intense red PL emission and long lifetime was obtained from 10 mol% Eu3+:La2Ti2O7:Eu3+, dispersed into silica matrix, and prepared in the presence of CTAB. The high PL Nano-phosphor has been successfully used in developing latent fingerprint from various forensic relevant materials.

Synthesis of Carbon-Coated ZnO Composite and Varistor Properties Study

NASA Astrophysics Data System (ADS)

Sun, Wei-Jie; Liu, Jin-Ran; Yao, Da-Chuan; Chen, Yong; Wang, Mao-Hua

2017-03-01

In this article, monodisperse ZnO composite nanoparticles were successfully prepared by sol-gel mixed precursor method. Subsequently, carbon as the shell was homogeneously coated on the surface of the ZnO composite nanoparticles via a simple adsorption and calcination process. Microstructural studies of the as-obtained powders were carried out using the techniques of the x-ray powder diffraction, scanning electron microscopy, field emission scanning electron microscopy, transmission electron microscopy with energy dispersive x-ray spectroscopy, and Fourier transform infrared spectroscopy. The results show that the pink ZnO composite powders were fully coated by carbon. Based on the results, the effect of glucose content on the microstructure of the synthesized composites and the electrical properties of the ZnO varistors sintered in air at 1150°C for 2 h were also fully studied. As the amount of glucose increased, the thickness of carbon can be increased from 2.5 nm to 5 nm. In particular, the ZnO varistor fabricated with the appropriate thickness of the carbon coating (5 nm) leads to the superior electrical performance, with present high breakdown voltage ( V b = 420 V/mm) and excellent nonlinear coefficient ( α = 61.7), compared with the varistors obtained without carbon coating.

In vitro bioactivity and antimicrobial tuning of bioactive glass nanoparticles added with neem (Azadirachta indica) leaf powder.

PubMed

Prabhu, M; Ruby Priscilla, S; Kavitha, K; Manivasakan, P; Rajendran, V; Kulandaivelu, P

2014-01-01

Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications.

Piroxicam cocrystals with phenolic coformers: preparation, characterization, and dissolution properties.

PubMed

Emami, Shahram; Adibkia, Khosro; Barzegar-Jalali, Mohammad; Siahi-Shadbad, Mohammadreza

2018-04-04

This study explores the preparation and investigation of dissolution properties of piroxicam cocrystals. Differential scanning calorimetry (DSC) was used to determine the capability of resorcinol (RES), methylparaben (MPB), and vanillin (VAN) to form cocrystals with piroxicam (PRX). Generation of cocrystals was attempted by liquid assisted grinding and slurry methods. Cocrystals were characterized by thermal methods, powder X-ray diffraction, and Fourier-transform infrared spectroscopy. Apparent solubility, intrinsic dissolution rate (IDR), and powder dissolution profile of cocrystals were compared with anhydrous piroxicam, piroxicam monohydrate (PRXMH), and previously reported piroxicam-succinic acid cocrystal. Contact angles and particle sizes of the studied solids were also measured. Based on the DSC screening results, we prepared and characterized PRX-RES and PRX-MPB cocrystals. Interestingly, the cocrystals not only failed to improve apparent solubility and IDR of PRX but also showed lower values than PRX that were attributed to induction of phase transformation of PRX to PRXMH. In contrary, cocrystals performed better than PRX in powder dissolution studies. The higher dissolution rates of cocrystals were explained by improved wettability and reduced sizes. This study has highlighted the complexity of solid state properties of cocrystals and has provided new evidence for the in-solution stability issues of cocrystals.

In Vitro Bioactivity and Antimicrobial Tuning of Bioactive Glass Nanoparticles Added with Neem (Azadirachta indica) Leaf Powder

PubMed Central

Prabhu, M.; Ruby Priscilla, S.; Kavitha, K.; Manivasakan, P.; Rajendran, V.; Kulandaivelu, P.

2014-01-01

Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications. PMID:25276834

Preparation of fine powdered composite for latent heat storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fořt, Jan, E-mail: jan.fort.1@fsv.cvut.cz; Trník, Anton, E-mail: anton.trnik@fsv.cvut.cz; Pavlíková, Milena, E-mail: milena.pavlikova@fsv.cvut.cz

Application of latent heat storage building envelope systems using phase-change materials represents an attractive method of storing thermal energy and has the advantages of high-energy storage density and the isothermal nature of the storage process. This study deals with a preparation of a new type of powdered phase change composite material for thermal energy storage. The idea of a composite is based upon the impregnation of a natural silicate material by a reasonably priced commercially produced pure phase change material and forming the homogenous composite powdered structure. For the preparation of the composite, vacuum impregnation method is used. The particlemore » size distribution accessed by the laser diffraction apparatus proves that incorporation of the organic phase change material into the structure of inorganic siliceous pozzolana does not lead to the clustering of the particles. The compatibility of the prepared composite is characterized by the Fourier transformation infrared analysis (FTIR). Performed DSC analysis shows potential of the developed composite for thermal energy storage that can be easily incorporated into the cement-based matrix of building materials. Based on the obtained results, application of the developed phase change composite can be considered with a great promise.« less

Facile synthesis of Curcuma longa tuber powder engineered metal nanoparticles for bioimaging applications

NASA Astrophysics Data System (ADS)

Sankar, Renu; Rahman, Pattanathu K. S. M.; Varunkumar, Krishnamoorthy; Anusha, Chidambaram; Kalaiarasi, Arunachalam; Shivashangari, Kanchi Subramanian; Ravikumar, Vilwanathan

2017-02-01

Nanomaterials based fluorescent agents are rapidly becoming significant and promising transformative tools for improving medical diagnostics for extensive in vivo imaging modalities. Compared with conventional fluorescent agents, nano-fluorescence has capabilities to improve the in vivo detection and enriched targeting efficiencies. In our laboratory we synthesized fluorescent metal nanoparticles of silver, copper and iron using Curcuma longa tuber powder by simple reduction. The physicochemical properties of the synthesized metal nanoparticles were attained using UV-visible spectrophotometry, scanning electron microscopy with EDAX spectroscopy, dynamic light scattering, Fourier-transform infrared spectroscopy and X-ray diffraction. The Curcuma longa tuber powder has one of the bioactive compound Curcumin might act as a capping agent during the synthesis of nanoparticles. The synthesized metal nanoparticles fluorescence property was confirmed by spectrofluorometry. When compared with copper and iron nanoparticles the silver nanoparticles showed high fluorescence intensity under spectrofluorometry. Moreover, in vitro cell images of the silver nanoparticles in A549 cell lines also correlated with the results of spectrofluorometry. These silver nanoparticles show inspiring cell-imaging applications. They enter into cells without any further modifications, and the fluorescence property can be utilized for fluorescence-based cell imaging applications.

Vibrational spectra, powder X-ray diffractions and physical properties of cyanide complexes with 1-ethylimidazole

NASA Astrophysics Data System (ADS)

Kürkçüoğlu, Güneş Süheyla; Kiraz, Fulya Çetinkaya; Sayın, Elvan

2015-10-01

The heteronuclear tetracyanonickelate(II) complexes of the type [M(etim)Ni(CN)4]n (hereafter, abbreviated as M-Ni-etim, M = Mn(II), Fe(II) or Co(II); etim = 1-ethylimidazole, C5H8N2) were prepared in powder form and characterized by FT-IR and Raman spectroscopy, powder X-ray diffraction (PXRD), thermal (TG; DTG and DTA), and elemental analysis techniques. The structures of these complexes were elucidated using vibrational spectra and powder X-ray diffraction patterns with the peak assignment to provide a better understanding of the structures. It is shown that the spectra are consistent with a proposed crystal structure for these compounds derived from powder X-ray diffraction measurements. Vibrational spectra of the complexes were presented and discussed with respect to the internal modes of both the etim and the cyanide ligands. The C, H and N analyses were carried out for all the complexes. Thermal behaviors of these complexes were followed using TG, DTG and DTA curves in the temperature range 30-700 °C in the static air atmosphere. The FT-IR, Raman spectra, thermal and powder X-ray analyses revealed no significant differences between the single crystal and powder forms. Additionally, electrical and magnetic properties of the complexes were investigated. The FT-IR and Raman spectroscopy, PXRD, thermal and elemental analyses results propose that these complexes are similar in structure to the Hofmann-type complexes.

Near-Infrared Photoluminescence Enhancement in Ge/CdS and Ge/ZnS Core/Shell Nanocrystals: Utilizing IV/II-VI Semiconductor Epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Yijun; Rowland, Clare E; Schaller, Richard D

2014-08-26

Ge nanocrystals have a large Bohr radius and a small, size-tunable band gap that may engender direct character via strain or doping. Colloidal Ge nanocrystals are particularly interesting in the development of near-infrared materials for applications in bioimaging, telecommunications and energy conversion. Epitaxial growth of a passivating shell is a common strategy employed in the synthesis of highly luminescent II–VI, III–V and IV–VI semiconductor quantum dots. Here, we use relatively unexplored IV/II–VI epitaxy as a way to enhance the photoluminescence and improve the optical stability of colloidal Ge nanocrystals. Selected on the basis of their relatively small lattice mismatch comparedmore » with crystalline Ge, we explore the growth of epitaxial CdS and ZnS shells using the successive ion layer adsorption and reaction method. Powder X-ray diffraction and electron microscopy techniques, including energy dispersive X-ray spectroscopy and selected area electron diffraction, clearly show the controllable growth of as many as 20 epitaxial monolayers of CdS atop Ge cores. In contrast, Ge etching and/or replacement by ZnS result in relatively small Ge/ZnS nanocrystals. The presence of an epitaxial II–VI shell greatly enhances the near-infrared photoluminescence and improves the photoluminescence stability of Ge. Ge/II–VI nanocrystals are reproducibly 1–3 orders of magnitude brighter than the brightest Ge cores. Ge/4.9CdS core/shells show the highest photoluminescence quantum yield and longest radiative recombination lifetime. Thiol ligand exchange easily results in near-infrared active, water-soluble Ge/II–VI nanocrystals. We expect this synthetic IV/II–VI epitaxial approach will lead to further studies into the optoelectronic behavior and practical applications of Si and Ge-based nanomaterials.« less

Preparation of LiFePO{sub 4} with inverse opal structure and its satisfactory electrochemical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu Junbiao; Tang Zilong; Zhang Zhongtai

Phase pure, well-crystallized and homogeneous LiFePO{sub 4} powder with inverse opal structure was obtained by calcining the precursors of Li{sup +}, Fe{sup 2+} and PO{sub 4} {sup 3-} in the presence of organic template of poly(styrene-methyl methacrylate-acrylic acid) latex micro-spheres under nitrogen atmosphere. The resultant products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), chemical titration, Fourier transform infrared (FTIR) and Land 2001A electrochemical measurement system. Results indicated that after the decomposition of organic template, inverse opal structure and conductive carbon were left in the resultant products. With the large specific surface areamore » resulting from inverse opal structure and with the conductive carbon, the products delivered satisfactory capacity and superior rate capability at room temperature, i.e., over 100 mAh/g at the high current density of 5.9C.« less

A Direct Ultrasound Irradiation Method Synthesis of Monodisperse ZnO Microspheres for Varistors Ceramics Application

NASA Astrophysics Data System (ADS)

Chen, Tao; Wang, Mao-Hua; Zhang, Han-Ping; Liu, Jin-Ran; Yao, Da-Chuan

2016-08-01

Monodisperse and uniform ZnO microspheres were synthesized via an ultrasound irradiation method. The microstructure and morphology of the as-prepared sample were characterized by x-ray powder diffraction, Fourier transformation infrared spectra and scanning electron microscopy. The results indicate that the size of ZnO microspheres was strongly affected by the Zn(NO3)2·6H2O. As the amount of the precursor increased, the diameters of the ZnO microspheres can be turned from ˜500 nm to ˜2 μm. The electrical properties of the varistors ceramics prepared from the as-obtained ZnO powders were investigated. The results show that the varistors ceramics made from ZnO with a size of ˜500 nm and sintered in air at 1150°C for 2 h possess a density of 5.50 g/cm3 corresponding to 95.1% of the theoretical density, with breakdown voltage of 280.9 V/mm and nonlinear coefficient of ˜61.3.

Photosensitized synthesis of silver nanoparticles using Withania somnifera leaf powder and silver nitrate.

PubMed

Raut, Rajesh Warluji; Mendhulkar, Vijay Damodhar; Kashid, Sahebrao Balaso

2014-03-05

The metal nanoparticle synthesis is highly explored field of nanotechnology. The biological methods seem to be more effective; however, due to slow reduction rate and polydispersity of the resulting products, they are less preferred. In the present study, we report rapid and facile synthesis of silver nanoparticles at room temperature. The exposure of reaction mixtures containing silver nitrate and dried leaf powder of Withania somnifera Linn to direct sunlight resulted in reduction of metal ions within five minutes whereas, the dark exposure took almost 12h. Further studies using different light filters reveal the role of blue light in reduction of silver ions. The synthesized silver nanoparticles were characterized by UV-Vis, Infrared spectroscopy (IR), Transmission Electron Microscopy (TEM), X-ray Diffraction studies (XRD), Nanoparticle Tracking Analysis (NTA), Energy Dispersive Spectroscopy (EDS), and Cyclic Voltammetry (CV). The Antibacterial and antifungal studies showed significant activity as compared to their respective standards. Copyright © 2014 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deus, R.C.; Cortés, J.A., E-mail: leandrosrr89@gmail.com; Ramirez, M.A.

Highlights: • CeO{sub 2} nanoparticles were obtained by microwave-hydrothermal method. • Rietveld refinement reveals a cubic structure. • KOH mineralizer agent exhibit weak agglomeration at low temperature and shorter time. - Abstract: The structural and photoluminescent properties at room temperature of CeO{sub 2} and La-doped CeO{sub 2} particles were undertaken. The obtained particles were synthesized by a microwave-assisted hydrothermal method (MAH) under different lanthanum contents. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Fourier transform Raman (FT-Raman), Ultra-violet spectroscopy (UV–vis) and photoluminescence (PL) measurements were carried out. XRD revealed that the powders are free of secondary phases and crystallize in themore » cubic structure. Raman data show that increasing La doping content increase oxygen vacancies due to lattice expansion. The UV/vis absorption spectroscopy suggested the presence of intermediate energy levels in the band gap of structurally ordered powders. Lanthanum addition creates oxygen vacancies and shifts the photoluminescence in the low energy range leading to intense PL emission.« less

Synthesis, crystal growth and characterization of a phase matchable nonlinear optical single crystal: p-chloro dibenzylideneacetone

NASA Astrophysics Data System (ADS)

Ravindra, H. J.; John Kiran, A.; Nooji, Satheesha Rai; Dharmaprakash, S. M.; Chandrasekharan, K.; Kalluraya, Balakrishna; Rotermund, Fabian

2008-05-01

Good quality single crystals of p-chloro dibenzylideneacetone (CDBA) of size 13 mm×8 mm×2 mm were grown by slow evaporation solution growth technique. The grown crystals were confirmed by elemental analysis, Fourier transform infrared (FTIR) analysis and single crystal X-ray diffraction techniques. From the thermo gravimetric/differential thermal (TG/DT) analysis, the CDBA was found to be thermally stable up to 250 °C. The mechanical stability of the crystal is comparable with that of the other reported chalcones. The lower optical cut-off wavelength for this crystal was observed at 440 nm. The laser damage threshold of the crystal was 0.6 GW/cm 2 at 532 nm. The second harmonic generation conversion efficiency of the powder sample of CDBA was found to be 4.5 times greater than that of urea. We also demonstrate the existence of the phase matching property in this crystal using Kurtz powder technique.

[Preparation of panax notoginseng saponins-tanshinone H(A) composite method for pulmonary delivery with spray-drying method and its characterization].

PubMed

Wang, Hua-Mei; Fu, Ting-Ming; Guo, Li-Wei

2013-02-01

To prepare panax notoginseng saponins-tanshinone II(A) composite particles for pulmonary delivery, in order to explore a dry powder particle preparation method ensuring synchronized arrival of multiple components of traditional Chinese medicine compounds at absorption sites. Panax notoginseng saponins-tanshinone II(A) composite particles were prepared with spray-drying method, and characterized by scanning electron microscopy (SEM), confocal laser scanning microscope (CLSM), X-ray diffraction (XRD), infrared analysis (IR), dry laser particle size analysis, high performance liquid chromatography (HPLC) and the aerodynamic behavior was evaluated by a Next Generation Impactor (NGI). The dry powder particles produced had narrow particle size distribution range and good aerodynamic behavior, and could realize synchronized administration of multiple components. The spray-drying method is used to combine traditional Chinese medicine components with different physical and chemical properties in the same particle, and product into traditional Chinese medicine compound particles in line with the requirements for pulmonary delivery.

Magnetic properties of Li0.5Fe2.5O4 nanoparticles synthesized by solution combustion method

NASA Astrophysics Data System (ADS)

Naderi, P.; Masoudpanah, S. M.; Alamolhoda, S.

2017-11-01

In this research, lithium ferrite (Li0.5Fe2.5O4) powders were prepared by solution combustion synthesis using glycine and citric acid fuels at various fuel to oxidant molar ratios ( ϕ = 0.5, 1 and 1.5). Phase evolution, microstructure and magnetic properties were characterized by thermal analysis, infrared spectroscopy, X-ray diffraction, electron microscopy and vibration sample magnetometry techniques. Single-phase lithium ferrite was formed using glycine fuel at all fuel to oxidant ratios, while some impurity α-Fe2O3 phase was appeared using citric acid fuel at ϕ ≥ 1. The phase and crystallite size mainly depended on the combustion rate through fuel type. Bulky microstructure observed for citric acid fuel was attributed to its slow combustion, while the fast exhausting of gaseous products led to spongy microstructure for glycine fuel. The highest saturation magnetization of 59.3 emu/g and coercivity of 157 Oe were achieved for the as-combusted powders using glycine fuel.

Evaluation of High-Performance Curcumin Nanocrystals for Pulmonary Drug Delivery Both In Vitro and In Vivo

NASA Astrophysics Data System (ADS)

Hu, Liandong; Kong, Dongqian; Hu, Qiaofeng; Gao, Na; Pang, Saixi

2015-10-01

This paper focused on formulating high-performance curcumin spray-dried powders for inhalation (curcumin-DPIs) to achieve a high lung concentration. Curcumin-DPIs were produced using wet milling combined with the spray drying method. The effects of different milling times on particle size and aerodynamic performance were investigated. The curcumin-DPIs were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), and in vitro dissolution. Furthermore, the in vivo pharmacokinetic behavior and tissue distribution after pulmonary administration were also evaluated. Results showed that the drug dissolution was significantly enhanced by processing into curcumin-DPIs. The aerodynamic results indicated that the DPIs displayed a good aerosol performance. The plasma curcumin concentration was obviously enhanced by inhalation, and most of the curcumin-DPIs were deposited in the lung. This study demonstrated that inhalation was an effective way to carry drug to the lung, and curcumin-DPIs were hopeful for lung cancer treatment in the future.

Development of hydroxyapatite derived from Indian coral.

PubMed

Sivakumar, M; Kumar, T S; Shantha, K L; Rao, K P

1996-09-01

A simple method of converting the calcium carbonate skeleton of the corals available in the Indian coast into hydroxyapatite granules has been developed. By heating the coral to 900 degrees C, the organic materials were eliminated. Powder X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were employed to characterize the coral and to optimize the processing parameters as well as to confirm the hydroxyapatite formation. The coral used exhibits the presence of both aragonite and calcite phases (dimorphism). At a temperature of 900 degrees C the coral was found to decompose all the carbonate phases. The pre-heated coral is converted into hydroxyapatite by a chemical exchange reaction with di-ammonium phosphate under hydrothermal conditions. The hydroxyapatite obtained was in powder form and does not contain any impurities. The in vitro solubility test of the apatite granules performed in Gomoris, Michalelis, Sorensens, Ringer's and phosphate buffer of pH 7.2 and de-ionized water indicated the stability of the coralline hydroxyapatite.

Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

DOE PAGES

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit; ...

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials and in situ and operando diffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, overmore » a continuous range of diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. In addition, the design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less

A new theory for X-ray diffraction

PubMed Central

Fewster, Paul F.

2014-01-01

This article proposes a new theory of X-ray scattering that has particular relevance to powder diffraction. The underlying concept of this theory is that the scattering from a crystal or crystallite is distributed throughout space: this leads to the effect that enhanced scatter can be observed at the ‘Bragg position’ even if the ‘Bragg condition’ is not satisfied. The scatter from a single crystal or crystallite, in any fixed orientation, has the fascinating property of contributing simultaneously to many ‘Bragg positions’. It also explains why diffraction peaks are obtained from samples with very few crystallites, which cannot be explained with the conventional theory. The intensity ratios for an Si powder sample are predicted with greater accuracy and the temperature factors are more realistic. Another consequence is that this new theory predicts a reliability in the intensity measurements which agrees much more closely with experimental observations compared to conventional theory that is based on ‘Bragg-type’ scatter. The role of dynamical effects (extinction etc.) is discussed and how they are suppressed with diffuse scattering. An alternative explanation for the Lorentz factor is presented that is more general and based on the capture volume in diffraction space. This theory, when applied to the scattering from powders, will evaluate the full scattering profile, including peak widths and the ‘background’. The theory should provide an increased understanding of the reliability of powder diffraction measurements, and may also have wider implications for the analysis of powder diffraction data, by increasing the accuracy of intensities predicted from structural models. PMID:24815975

Studies on magnetic properties of chemically synthesized crystalline calcium ferrite nanoparticles

NASA Astrophysics Data System (ADS)

Debnath, A.; Bera, A.; Chattopadhyay, K. K.; Saha, B.

2016-05-01

Spinel-type ferrites have taken a very important role for modern electronic industry. Most of these ferrites exhibit low-loss dielectric properties, high resistivity, low eddy current and also high temperature ferromagnetism. Calcium ferrite is one such important metal oxide which is environmentally safe, chemically stable, low cost and greatly abundant. This outstanding material of calcium ferrite is synthesized by a simple chemical precipitation method using NaOH as the precipitating agent. Ferric chloride anhydrous (FeCl3) and Calcium chloride dihydrate (CaCl2.2H2O) were used as iron and calcium sources respectively. The samples were heated at 200°C for 8h to obtain homogeneous powder of Calcium ferrite. The powders were characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Transmission electrical microscopy (TEM), and Fourier transform infrared spectroscopic (FTIR) measurements. The polycrystalline nature of the sample was confirmed by X-ray diffraction study. The magnetic properties of the sample were investigated by vibrating sample magnetometer (VSM) measurements. Magnetization curve of the prepared sample depicts that as synthesized calcium ferrite nanoparticles have saturation magnetic moment of 1.74 emu/g and the coercivity of 35.08 Oe with superparamagnetic behavior. The synthesized calcium ferrite nanoparticles with such magnetic properties will be a candidate material for different applications in electronics and exploring its functionality in the field of recently developing semiconductor device physics and spintronics.

Pb 2MnTeO 6 Double Perovskite: An Antipolar Anti-ferromagnet

DOE PAGES

Retuerto, Maria; Skiadopoulou, Stella; Li, Man-Rong; ...

2016-04-08

Pb 2MnTeO 6, a new double perovskite, has been synthesized. Its crystal structure was determined by synchrotron X-ray and powder neutron diffraction.Pb 2MnTeO 6 is monoclinic (I2/m) at room temperature with a regular arrangement of all the cations in their polyhedra. However, when the temperature is lowered to ~120 K it undergoes a phase transition from I2/m to C2/c structure. This transition is accompanied by a displacement of the Pb atoms from the center of their polyhedra due to the 6s 2 lone-pair electrons, together with a surprising off-centering of Mn 2+ (d 5) magnetic cations. This strong first-order phasemore » transition is also evidenced by specific heat, dielectric, Raman, and infrared spectroscopy measurements. The magnetic characterizations indicate an anti-ferromagnetic (AFM) order below T N ≈ 20 K; analysis of powder neutron diffraction data confirms the magnetic structure with propagation vector k = (0 1 0) and collinear AFM spins. The observed jump in dielectric permittivity near ~150 K implies possible anti-ferroelectric behavior; however, the absence of switching suggests that Pb 2MnTeO 6 can only be antipolar. First-principle calculations confirmed that the crystal and magnetic structures determined are locally stable and that anti-ferroelectric switching is unlikely to be observed in Pb 2MnTeO 6.« less

Growth and characterization of an organic single crystal: 2-[2-(4-Diethylamino-phenyl)-vinyl]-1-methyl-pyridinium iodide

NASA Astrophysics Data System (ADS)

Senthil, K.; Kalainathan, S.; Ruban Kumar, A.

Optically transparent crystal of the organic salt DEASI (2-[2-(4-Diethylamino-phenyl)-vinyl]-1-methyl-pyridinium iodide) has been synthesized by using knoevenagel condensation reaction method. The synthesized material has been purified by successfully recrystallization process. Single crystals of DEASI have been grown by slow evaporation technique at room temperature. The solubility of the title material has been determined at different temperature in acetonitrile/methanol mixture. The cell parameters and crystallinity of the title crystal were determined by single crystal XRD. The powder diffraction was carried out to study the reflection plane of the grown crystal and diffraction peaks were indexed. The presence of different functional groups in the crystal was confirmed by Fourier transform infrared (FTIR) analysis. 1H NMR spectrum was recorded to confirm the presence of hydrogen nuclei in the synthesized material. The optical property of the title crystal was studied by UV-Vis-NIR spectroscopic analysis. The melting point and thermal property of DEASI were studied using TGA/DSC technique. The Vicker’s hardness (Hv) was carried out to know the category. The dielectric constant and dielectric loss of the compound decreases with an increase in frequencies. Chemical etching studies showed that the DEASI grows in the two dimensional growth mechanisms. The Kurtz-Perry powder second harmonic generation (SHG) test has done for title crystal.

Growth and characterization of an organic single crystal: 2-[2-(4-diethylamino-phenyl)-vinyl]-1-methyl-pyridinium iodide.

PubMed

Senthil, K; Kalainathan, S; Ruban Kumar, A

2014-05-05

Optically transparent crystal of the organic salt DEASI (2-[2-(4-Diethylamino-phenyl)-vinyl]-1-methyl-pyridinium iodide) has been synthesized by using knoevenagel condensation reaction method. The synthesized material has been purified by successfully recrystallization process. Single crystals of DEASI have been grown by slow evaporation technique at room temperature. The solubility of the title material has been determined at different temperature in acetonitrile/methanol mixture. The cell parameters and crystallinity of the title crystal were determined by single crystal XRD. The powder diffraction was carried out to study the reflection plane of the grown crystal and diffraction peaks were indexed. The presence of different functional groups in the crystal was confirmed by Fourier transform infrared (FTIR) analysis. (1)H NMR spectrum was recorded to confirm the presence of hydrogen nuclei in the synthesized material. The optical property of the title crystal was studied by UV-Vis-NIR spectroscopic analysis. The melting point and thermal property of DEASI were studied using TGA/DSC technique. The Vicker's hardness (Hv) was carried out to know the category. The dielectric constant and dielectric loss of the compound decreases with an increase in frequencies. Chemical etching studies showed that the DEASI grows in the two dimensional growth mechanisms. The Kurtz-Perry powder second harmonic generation (SHG) test has done for title crystal. Copyright © 2014 Elsevier B.V. All rights reserved.

Synchrotron X-ray powder diffraction data of LASSBio-1515: A new N-acylhydrazone derivative compound

NASA Astrophysics Data System (ADS)

Costa, F. N.; Braz, D.; Ferreira, F. F.; da Silva, T. F.; Barreiro, E. J.; Lima, L. M.; Colaço, M. V.; Kuplich, L.; Barroso, R. C.

2014-02-01

In this work, synchrotron X-ray powder diffraction data allowed for a successful indexing of LASSBio-1515 compound, candidate to analgesic and anti-inflammatory activity. X-ray powder diffraction data collected in transmission and high-throughput geometries were used to analyze this compound. The X-ray wavelength of the synchrotron radiation used in this study was determined to be λ=1.55054 Å. LASSBio-1515 was found to be monoclinic with space group P21/c and unit cell parameters a=11.26255(16) Å, b=12.59785(16) Å, c=8.8540(1) Å, β=90.5972(7)° and V=1256.17(3) Å3.

Crystal growth, structural, optical, mechanical and thermal properties of a new nonlinear optical single crystal: L-Ornithine monohydrochloride.

PubMed

Balakrishnan, T; Ramamurthi, K

2009-03-01

Amino acid family crystals exhibit excellent nonlinear optical and electro optical properties. l-Ornithine monohydrochloride single crystal, belongs to the amino acid group, was grown by the slow evaporation solution growth technique at room temperature. The grown crystals were characterized by single crystal and powder X-ray diffraction analysis, Fourier transform infrared (FTIR) spectroscopy, TGA, DTA and DSC analyses. UV-vis-NIR spectrum shows excellent transmission in the UV, visible and NIR region (300-1600nm). The mechanical properties of grown crystals were studied using Vickers microhardness tester. Its second harmonic generation efficiency was tested using Nd:YAG laser and is 1.25 times that of KDP.

Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound.

PubMed

Pais, Joana M; Barroca, Maria João; Marques, Maria Paula M; Almeida Paz, Filipe A; Braga, Susana S

2017-01-01

Fisetin is a natural antioxidant with a wide range of nutraceutical properties, including antidiabetic, neuroprotecting, and suppression or prevention of tumors. The present work describes the preparation of a water-soluble, solid inclusion compound of fisetin with gamma-cyclodextrin (γ-CD), a cyclic oligosaccharide approved for human consumption. A detailed physicochemical analysis of the product is carried out using elemental analysis, powder X-ray diffraction (PXRD), Raman, infrared and 13 C{ 1 H} CP-MAS NMR spectroscopies, and thermal analysis (TGA) to verify fisetin inclusion and to present a hypothetical structural arrangement for the host-guest units. The antioxidant activity of the γ-CD·fisetin inclusion compound is evaluated by the DPPH assay.

Aging effects in bulk and fiber TlBr-TlI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wysocki, J.A.; Wilson, R.G.; Standlee, A.G.

1988-05-01

A study of optical aging in bulk and extruded fibers of thallium bromo-iodide (TlBr-TlI) is presented. A variety of techniques including secondary ion mass spectrometry (SIMS), powder neutron and x-ray diffraction, infrared spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy are used to probe the chemical and structural properties of both pristine and aged material. High concentration levels of a hydrogen bearing impurity have been detected by SIMS and neutron scattering in aged TlBr-TlI, and have been shown to be localized in the surface layers of fibers as well as bulk samples. We present EPR evidence which indicates that the hydrogenmore » bearing impurity is water.« less

Efficient mechanochemical bifunctional nanocatalysts for the conversion of isoeugenol to vanillin

NASA Astrophysics Data System (ADS)

Ostovar, Somayeh; Franco, Ana; Puente-Santiago, Alain R.; Pinilla-de Dios, María; Rodríguez-Padrón, Daily; Shaterian, Hamid R.; Luque, Rafael

2018-04-01

A novel highly functionalized nanocatalyst composed of iron containing SBA-15 material modified with sulfonic acid groups was synthesized by a mechanochemical approach. A full characterization of the obtained nanoreactor was performed by N2 physisorption isotherms analysis, transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and Fourier-Infrared Spectroscopy (FT-IR). The mechanochemically synthesized nanocatalyst displays a high isoeugenol conversion to vanillin under mild conditions using H2O2 as oxidizing agent. Interestingly, this conversion resulted to be higher than that one obtained with the same material synthesized by an impregnation method. Additionally, the nanoreactor showed excellent reusability over four successive runs under the studied reaction conditions.

A Green Protocol for Synthesis of MAl2O4, [M=Cu and Co] Spinels Under Microwave Irradiation Method

NASA Astrophysics Data System (ADS)

Yuvasravana, R.; George, P. P.

Nanosized metal aluminates MAl2O4, [M=Cu and Co] are synthesized from their nitrates solution by using pomegranate peel extract as fuel in microwave combustion. MAl2O4 [M=Cu and Co] nanoparticles are grown in microwave assisted synthesis followed by annealing at 700∘C. The nanoparticles have been characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV-VIS spectroscopy and photoluminescence (PL) spectroscopy. The PXRD analysis has confirmed their spinel composition. The green protocol and microwave combustion route for spinel synthesis are rapid, simple, without any hazardous chemicals as reducing or stabilizing agents and economical.

Nanoparticles of wurtzite aluminum nitride from the nut shells

NASA Astrophysics Data System (ADS)

Qadri, S. B.; Gorzkowski, E. P.; Rath, B. B.; Feng, C. R.; Amarasinghe, R.

2016-11-01

Nanoparticles of aluminum nitride were produced from a thermal treatment of a mixture of aluminum oxide (Al2O3) and shells of almond, cashew, coconuts, pistachio, and walnuts in a nitrogen atmosphere at temperatures in excess of 1450 °C. By selecting the appropriate ratios of each nut powder to Al2O3, it is shown that stoichiometric aluminum nitride can be produced by carbo-thermal reduction in nitrogen atmosphere. Using x-ray diffraction analysis, Raman scattering and Fourier Transform Infrared spectroscopy, it is demonstrated that aluminum nitride consists of pure wurtzite phase. Transmission electron microscopy showed the formation of nanoparticles and in some cases nanotubes of AlN.

Rietveld refinement and FTIR analysis of bulk ceramic Co3-xMnxO4 compositions

NASA Astrophysics Data System (ADS)

Meena, P. L.; Kumar, Ravi; Sreenivas, K.

2013-02-01

Co3-xMnxO4 (x = 0.0, 0.6, 1.2) prepared by solid state reaction method and characterized by powder X-ray diffraction (XRD) and Fourier transform infrared (FTIR). Lattice parameters (a), oxygen parameter (u), and ionic radii of cations have been determined through Rietveld analysis. Both a and u parameters are related to expansion of octahedral site as Mn content in Co3O4. Analysis of XRD data show that Mn (x ≤ 1.2) is accommodated at the octahedral site, while retaining the cubic spinel structure. FTIR results also confirm the same and signify strong interactions due to overlapping of Co and Mn octahedra.

Solid-state NMR and IR for the analysis of pharmaceutical solids: polymorphs of fosinopril sodium.

PubMed

Brittain, H G; Morris, K R; Bugay, D E; Thakur, A B; Serajuddin, A T

1993-01-01

The two polymorphic modifications of fosinopril sodium have been characterized as to their differences in melting behaviour, powder X-ray diffraction patterns, Fourier transform infrared spectra (FTIR), and solid-state 31P- and 13C-NMR spectra. The polymorphs were found to be enantiotropically related based upon melting point, heat of fusion, and solution mediated transformation data. Analysis of the solid-state FTIR and 13C-NMR data indicated that the environment of the acetal side chain of fosinopril sodium differed in two polymorphs, and that there might be cis-trans isomerization about the C6-N peptide bond. These conformational differences are postulated as the origin of the observed polymorphism.

Identification of Ice Nucleation Active Sites on Feldspar Dust Particles

PubMed Central

2015-01-01

Mineral dusts originating from Earth’s crust are known to be important atmospheric ice nuclei. In agreement with earlier studies, feldspar was found as the most active of the tested natural mineral dusts. Here we investigated in closer detail the reasons for its activity and the difference in the activity of the different feldspars. Conclusions are drawn from scanning electron microscopy, X-ray powder diffraction, infrared spectroscopy, and oil-immersion freezing experiments. K-feldspar showed by far the highest ice nucleation activity. Finally, we give a potential explanation of this effect, finding alkali-metal ions having different hydration shells and thus an influence on the ice nucleation activity of feldspar surfaces. PMID:25584435

Synthesis and photoluminescence of ultra-pure germanium nanoparticles

NASA Astrophysics Data System (ADS)

Chivas, R.; Yerci, S.; Li, R.; Dal Negro, L.; Morse, T. F.

2011-09-01

We have used aerosol deposition to synthesize defect and micro-strain free, ultra-pure germanium nanoparticles. Transmission electron microscopy images show a core-shell configuration with highly crystalline core material. Powder X-ray diffraction measurements verify the presence of highly pure, nano-scale germanium with average crystallite size of 30 nm and micro-strain of 0.058%. X-ray photoelectron spectroscopy demonstrates that GeO x ( x ⩽ 2) shells cover the surfaces of the nanoparticles. Under optical excitation, these nanoparticles exhibit two separate emission bands at room temperature: a visible emission at 500 nm with 0.5-1 ns decay times and an intense near-infrared emission at 1575 nm with up to ˜20 μs lifetime.

Synthesis and Characterization of YVO4-Based Phosphor Doped with Eu3+ Ions for Display Devices

NASA Astrophysics Data System (ADS)

Thakur, Shashi; Gathania, Arvind K.

2015-10-01

YVO4:Eu nanophosphor has been synthesized by the sol-gel method. Samples were characterized by x-ray diffraction (XRD), energy-dispersive x-ray spectroscopy, Fourier-transform infrared spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, photoluminescence, and Raman spectroscopy. The XRD profile confirms the tetragonal phase of the Eu3+-doped YVO4 nanophosphor. The efficiency of the prepared phosphor was analyzed by means of its emission spectral profile. We also observed rich red emission from the prepared phosphor on excitation by an ultraviolet source. The calculated Commission International de l'Éclairage coordinates reveal excellent color purity efficiency. Such luminescent powder is useful as red phosphor in display device applications.

Copper-based 2D-coordination polymer as catalyst for allylation of aldehydes

NASA Astrophysics Data System (ADS)

da Silva, Gilson B.; Menezes, Paulo H.; Malvestiti, Ivani; Falcão, Eduardo H. L.; Alves, Severino, Jr.; Chojnacki, Jarosław; da Silva, Fausthon F.

2018-03-01

A copper-tartrate, [Cu2(Tart)2(H2O)2]·4H2O, was synthesized at room temperature in aqueous media using copper chloride and D-tartaric acid. The compound crystallizes in the monoclinic system P21 space group and was characterized by infrared spectroscopy, thermogravimetry, X-ray powder diffraction and the results are in good agreement with the single crystal structure. Catalytic properties for allylation of aldehydes were investigated at different solvents, and the best conditions obtained were using a mixture of CH2Cl2:H2O. The copper-tartrate obtained showed good performance as catalyst for different substrates and yields were between 62% and 95%.

Surface modification of silicon carbide with silane coupling agent and hexadecyl iodiele

NASA Astrophysics Data System (ADS)

Shang, Xujing; Zhu, Yumei; Li, Zhihong

2017-02-01

In this paper, two kinds of silane coupling agents, namely 3-aminopropyl triethoxysilane (KH550) and 3-mercaptopropyl trimethoxysilane (KH590), were adopted as preliminary modifiers to improve the hydrophobic surface properties of silicon carbide (SiC) powder for the first step. The factors that influence the modification effects were investigated by measuring the contact angle. The results showed that KH590 has a better effect than KH550 for the hydrophobic modification of SiC, and the contact angle improved most after SiC powder was reacted with 0.3 g KH590 at 75 °C in aqueous/alcohol solution for 4 h. On account of further enhancement of hydrophobicity, the study was focused on utilizing nucleophilic substitution between KH590 and hexadecyl iodiele to extend the length of alkyl chain. Compared with using KH590 alone, SiC powder modified by KH590 and hexadecyl iodiele showed better water resistance with an increase of contact angle from 106.8° to 127.5°. The Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectra (XPS) as well as X-ray diffraction (XRD) analysis results showed that KH550/KH590 and hexadecyl iodiele can be covalently bonded to the surface of SiC powder without altering its crystal configuration. This methodology may provide a new way of the modification of inorganic materials in further.

In-situ fabrication of zirconium-titanium nano-composite and its coating on Ti-6Al-4V for biomedical applications.

PubMed

Chellappa, Manickam; Vijayalakshmi, Uthirapathy

2017-02-01

In this study, nanocomposite powder consisting of zirconia and titania (Zr-Ti) have been synthesised by sol-gel method, with the aim of protecting Ti-6Al-4V surface. A simple and low cost electrophoretic deposition (EPD) technique has been employed for coating the nanocomposite material on Ti-6Al-4V. The prepared nanocomposite powder was characterised for its functional groups, phase purity, surface topography by Fourier transform infrared spectroscopy, powder X-ray diffraction and scanning electron microscopy. Further, the biocompatibility nature of the composite powder was studied by [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] colorimetric assay and fluorescence analysis with MG63 osteoblast cell lines. The electrochemical behaviour of composite coating was investigated by potentiodynamic polarization and electrochemical impedance method. The results obtained from the electrochemical techniques indicate more corrosion resistance behaviour with increase of R ct value with the corresponding decrease in R dl values. From the above findings, the composite coating acts as a barrier layer against corrosion by preventing the leaching of metal ions from a dense and defect free coating. A scratch test analyser was used to assess the integrity of the coating; the lower traction force value of composite coating with increase in load has confirmed the presence of thick adherent layer on the substrate.

[Preparation of coated tablets of glycyrrhetic acid-HP-beta-cyclodextrin tablets for colon-specific release].

PubMed

Cui, Qi-Hua; Cui, Jing-Hao; Zhang, Jin-Jin

2008-10-01

To prepare coated tablets of glycyrrhetinic acid and hydroxypropyl-beta-cyclodextrin (GTA-HP-beta-CYD) inclusion complex tablets for colon-specific release. In order to improve the solubility of GTA, the GTA-HP-beta-CYD inclusion complex was prepared by ultrasonic-lyophilization technique and its formation were characterized by X-ray powder diffraction profiles and infrared spectrometry. The effects of inclusion condition on the inclusion efficiency and stability coefficient of inclusion complex were investigated, respectively. After prepared GTA-HP-beta-CYD tablets by powder direct compression, the pH dependant polymer Eudragit III and/or mixed with Eudragit II were used for further coating materials in fluid-bed coater. The influences of coating weight on the GTA release in different pH conditions were evaluated to establish the method for prepering colon specific delivery tablets with pulsed release properties. The formation of inclusion complexes were proved by X-ray powder diffraction profile and phase solubility curve. The effect of pH value of solvent was played critical role on the preparation of GTA- HP-beta-CYD inclusion complex. And the inclusion efficiency of GTA was 9. 3% and the solubility was increased to 54. 6 times at optimized method. The Eudragit III coated GTA- HP-beta-CYD tablets with coating weight 10% and 16% were showed pH dependant colon specific release profiles with slow release rate. The release profile of tablets coated with the mixture of Eudragit II and Eudragit III (1:2) were indicated typical pH dependant colon specific and pulsed release properties while the coating weight was 17%. The preliminary method for preparation of colon specific release tablets containing glycyrrhetinic acid with improved solubility was established for further in vivo therapeutic experiment.

Observations on online educational materials for powder diffraction crystallography software.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toby, B. H.

2010-10-01

This article presents a series of approaches used to educate potential users of crystallographic software for powder diffraction. The approach that has been most successful in the author's opinion is the web lecture, where an audio presentation is coupled to a video-like record of the contents of the presenter's computer screen.

Frequency analysis for modulation-enhanced powder diffraction.

PubMed

Chernyshov, Dmitry; Dyadkin, Vadim; van Beek, Wouter; Urakawa, Atsushi

2016-07-01

Periodic modulation of external conditions on a crystalline sample with a consequent analysis of periodic diffraction response has been recently proposed as a tool to enhance experimental sensitivity for minor structural changes. Here the intensity distributions for both a linear and nonlinear structural response induced by a symmetric and periodic stimulus are analysed. The analysis is further extended for powder diffraction when an external perturbation changes not only the intensity of Bragg lines but also their positions. The derived results should serve as a basis for a quantitative modelling of modulation-enhanced diffraction data measured in real conditions.

Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials andin situandoperandodiffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, over a continuous range ofmore » diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. The design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less

Pressure-Induced Polymerization of LiN(CN) 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keefer, Derek W.; Gou, Huiyang; Purdy, Andrew P.

The high-pressure behavior of lithium dicyanamide (LiN(CN) 2) was studied with in situ Raman and infrared (IR) spectroscopies, and synchrotron angle-dispersive powder X-ray diffraction (PXRD) in a diamond anvil cell (DAC) to 22 GPa. The fundamental vibrational modes associated with molecular units were assigned using a combination of experimental data and density functional perturbation theory. Some low-frequency modes were observed for the first time. On the basis of spectroscopic and diffraction data, we suggest a polymorphic phase transformation at ~8 GPa, wherein dicyanamide ions remain as discrete molecular species. Above ca. 18 GPa, dicyanamide units polymerize, forming a largely disorderedmore » network, and the extent of polymerization may be increased by annealing at elevated temperature. The polymerized product consists of tricyanomelaminate-like groups containing sp 2-hybidized carbon–nitrogen bonds and exhibits a visible absorption edge near 540 nm. The product is recoverable to ambient conditions but is not stable in air/moisture.« less

Growth and characterization of barium complex of 1,3,5-triazinane-2,4,6-trione in gel: a corrosion inhibiting material

NASA Astrophysics Data System (ADS)

Divya, R.; Nair, Lekshmi P.; Bijini, B. R.; Nair, C. M. K.; Babu, K. Rajendra

2018-05-01

Good quality prismatic crystals of industrially applicable corrosion inhibiting barium complex of 1,3,5-triazinane-2,4,6-trione have been grown by conventional gel method. The crystal structure, packing, and nature of bonds are revealed in the single crystal X-ray diffraction analysis. The crystal has a three-dimensional polymeric structure having a triclinic crystal system with the space group P-1. The powder X-ray diffraction analysis confirms its crystalline nature. The functional groups present in the crystal are identified by Fourier transform infrared spectroscopy. Elemental analysis confirms the stoichiometry of the elements present in the complex. Thermogravimetric analysis and differential thermal analysis reveal its good thermal stability. The optical properties like band gap, refractive index and extinction coefficient are evaluated from the UV-visible spectral analysis. The singular property of the material, corrosion inhibition efficiency achieved by the adsorption of the sample molecules is determined by the weight loss method.

Design and synthesis of two luminescent Zn(II)-based coordination polymers with different structures regulated by different solvent system

NASA Astrophysics Data System (ADS)

Wu, Wei-Ping; Wen, Gui-Lin; Liao, Yi; Wang, Jun; Lu, Lu; Wu, Yu; Xie, Bin

2016-08-01

Two new coordination polymers (CPs) [Zn(HL)(H2O)]n (1) and [Zn3(L)2(H2O)2]n·(H2O)n (2), based on a multifunctional ligand combined carboxylate groups and a nitrogen donor group 5-(6-carboxypyridin-2-yl)isophthalic acid (H3L), have been synthesized under different solvent media and fully characterized by powder X-ray diffraction (PXRD), infrared (IR) spectra, elemental analyses (EA) and thermogravimetric analyses (TGA). Single-crystal X-ray diffraction analysis reveals that 1 shows 1D dimeric chain structure, while 2 gives a 3D dense packing framework. Topology analysis illustrates that 2 can be simplified as a 3-nodal net (4, 5, 6-connected net) with the point symbol of {44·62}{46·64}2{48·66·8}. In addition, solid state luminescent properties of two complexes have also been studied in detail, which may act as the potential optical materials.

The first 3-D LaIII-SrII heterometallic complex: Synthesis, structure and luminescent properties

NASA Astrophysics Data System (ADS)

Hong, Zhiwei; Ran, Jingwen; Li, Tao; Chen, Yanmei

2016-10-01

The first 3-D LaIII-SrII heterometallic complex, namely [La2Sr(pda)4(H2O)4]n·6nH2O (1, H2pda = pyridine-2,6-dicarboxylic acid), has been successfully synthesized under solvothermal conditions. Single crystal X-ray diffraction analysis reveals that complex 1 features a 3-D porous framework and displays a new topology. The crystal structure can be simplified to a 4,6-connected 3-D network with Schläfli symbol of {34·42·88·9}2{34·42}. The crystals also have been characterized by X-ray powder diffraction, elemental analysis, thermal analysis, and IR spectroscopy. The infrared spectral analysis indicates that complex 1 is a carboxylate coordinated compound, several water molecules exist in the compound. The thermal study shows that there are ten water molecules in the crystal structure. The luminescent property has also been investigated. It shows a blue-purple fluorescence emission.

Synthesis, structural, spectroscopic and optical studies of charge transfer complex salts.

PubMed

Manikandan, Maruthappan; Mahalingam, Thaiyan; Hayakawa, Yasuhiro; Ravi, Ganesan

2013-01-15

New charge transfer molecular complex adducts of picric acid (C6H3N3O7) with triethylamine (C6H15N) and dimethylformamide (HCON(CH3)2) were synthesized successfully for the first time. Chemical composition and stoichiometry of the synthesized complex salts were verified by CHN elemental analysis. Solubility of the complex salts have been determined by gravimetric method and single crystals of two new salts were grown by low temperature solution growth technique. Crystal system, crystalline nature and cell parameters of the grown crystals were determined by single crystal X-ray diffraction (SXRD) and powder X-ray diffraction (PXRD) analyses. The formations of the charge-transfer complex, functional groups and the modes of vibrations have been confirmed by Fourier transform infrared (FTIR) spectroscopy. In order to know the linear and nonlinear optical suitability for device fabrication, UV-Vis (UV) spectral analysis and relative second harmonic generation (SHG) efficiency test were performed for the grown crystals. Copyright © 2012 Elsevier B.V. All rights reserved.

Analysis of submicron-sized niflumic acid crystals prepared by electrospray crystallization.

PubMed

Ambrus, Rita; Radacsi, Norbert; Szunyogh, Tímea; van der Heijden, Antoine E D M; Ter Horst, Joop H; Szabó-Révész, Piroska

2013-03-25

Interest in submicron-sized drug particles has emerged from both laboratory and industrial perspectives in the last decade. Production of crystals in the nano size scale offers a novel way to particles for drug formulation solving formulation problems of drugs with low solubility in class II of the Biopharmaceutical Classification System. In this work niflumic acid nanoparticles with a size range of 200-800nm were produced by the novel crystallization method, electrospray crystallization. Their properties were compared to those from evaporative and anti-solvent crystallizations, using the same organic solvent, acetone. There is a remarkable difference in the product crystal size depending on the applied methods. The size and morphology were analyzed by scanning electron microscopy and laser diffraction. The structure of the samples was investigated using differential scanning calorimetry, Fourier-transformed infrared spectroscopy and X-ray powder diffraction. The particles produced using electrospray crystallization process were probably changing from amorphous to crystalline state after the procedure. Copyright © 2012 Elsevier B.V. All rights reserved.

Sulfaguanidine cocrystals: Synthesis, structural characterization and their antibacterial and hemolytic analysis.

PubMed

Abidi, Syed Sibte Asghar; Azim, Yasser; Khan, Shahper Nazeer; Khan, Asad U

2018-02-05

Sulfaguanidine (SG), belongs to the class of sulfonamide drug used as an effective antibiotic. In the present work, using crystal engineering approach two novel cocrystals of SG were synthesized (SG-TBA and SG-PT) with thiobarbutaric acid (TBA) and 1,10-phenanthroline (PT), characterized by solid state techniques viz., powder X-ray diffraction (PXRD), fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and the crystal structures were determined by single crystal X-ray diffraction studies. A comparative antibacterial activity and hemolytic potential was done on SG drug, coformers and their cocrystals. The tested cocrystals formulations showed almost two fold higher antibacterial activity against the tested strains of bacteria Gram-positive bacteria (S. mutans and E. faecalis) and Gram-negative bacteria (E. coli, K. pneumonia and E. clocae) over SG alone and their coformers. Cocrystal SG-TBA showed better antibacterial activity and reduced hemolysis, thereby, reduced cytotoxicity than SG-PT. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis, structural, spectroscopic and optical studies of charge transfer complex salts

NASA Astrophysics Data System (ADS)

Manikandan, Maruthappan; Mahalingam, Thaiyan; Hayakawa, Yasuhiro; Ravi, Ganesan

2013-01-01

New charge transfer molecular complex adducts of picric acid (C6H3N3O7) with triethylamine (C6H15N) and dimethylformamide (HCON(CH3)2) were synthesized successfully for the first time. Chemical composition and stoichiometry of the synthesized complex salts were verified by CHN elemental analysis. Solubility of the complex salts have been determined by gravimetric method and single crystals of two new salts were grown by low temperature solution growth technique. Crystal system, crystalline nature and cell parameters of the grown crystals were determined by single crystal X-ray diffraction (SXRD) and powder X-ray diffraction (PXRD) analyses. The formations of the charge-transfer complex, functional groups and the modes of vibrations have been confirmed by Fourier transform infrared (FTIR) spectroscopy. In order to know the linear and nonlinear optical suitability for device fabrication, UV-Vis (UV) spectral analysis and relative second harmonic generation (SHG) efficiency test were performed for the grown crystals.

Controllable synthesis of protein-conjugated lead sulfide nanocubes by using bovine hemoglobin as a capping agent

NASA Astrophysics Data System (ADS)

Yang, Guangrui; Qin, Dezhi; Zhang, Li

2014-06-01

A simple, convenient, and controllable strategy was reported in this contribution for protein-assisted synthesis BHb-conjugated PbS nanocubes. Powder X-ray diffraction, energy disperse X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and selected-area electron diffraction characterizations were used to determine the structure and morphology of BHb-conjugated PbS nanocubes. The prepared PbS nanocrystals with cubic rock salt structure were uniform and monodispersed with homogeneous size around 12 nm. The results of Fourier transform infrared and circular dichroism assay proved that Pb2+/PbS had coordination interaction with functional groups of BHb besides physical-binding effect, and the secondary structure of protein significantly changed with this interaction. Thermogravimetric analysis results confirmed the existence of BHb in PbS nanocrystals and indicated that the conjugate bonds existed between PbS and BHb. A clear perspective was shown here that special nanostructure could be created by using proteins as a mediating template at the inorganic-organic interface.

Physicochemical characterization and aerosol dispersion performance of organic solution advanced spray-dried cyclosporine A multifunctional particles for dry powder inhalation aerosol delivery

PubMed Central

Wu, Xiao; Zhang, Weifen; Hayes, Don; Mansour, Heidi M

2013-01-01

In this systematic and comprehensive study, inhalation powders of the polypeptide immunosuppressant drug – cyclosporine A – for lung delivery as dry powder inhalers (DPIs) were successfully designed, developed, and optimized. Several spray drying pump rates were rationally chosen. Comprehensive physicochemical characterization and imaging was carried out using scanning electron microscopy, hot-stage microscopy, differential scanning calorimetry, powder X-ray diffraction, Karl Fischer titration, laser size diffraction, and gravimetric vapor sorption. Aerosol dispersion performance was conducted using a next generation impactor with a Food and Drug Administration-approved DPI device. These DPIs displayed excellent aerosol dispersion performance with high values in emitted dose, respirable fraction, and fine particle fraction. In addition, novel multifunctional inhalation aerosol powder formulations of cyclosporine A with lung surfactant-mimic phospholipids were also successfully designed and developed by advanced organic solution cospray drying in closed mode. The lung surfactantmimic phospholipids were 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-dipalmitoyl-snglycero- 3-(phosphor-rac-1-glycerol). These cyclosporine A lung surfactant-mimic aerosol powder formulations were comprehensively characterized. Powder X-ray diffraction and differential scanning calorimetry confirmed that the phospholipid bilayer structure in the solid state was preserved following advanced organic solution spray drying in closed mode. These novel multifunctional inhalation powders were optimized for DPI delivery with excellent aerosol dispersion performance and high aerosol performance parameters. PMID:23569375

Design and fabrication of a real-time measurement system for the capsaicinoid content of Korean red pepper (Capsicum annuum L.) powder by visible and near-infrared spectroscopy

USDA-ARS?s Scientific Manuscript database

This research aims to design and fabricate a system to measure the capsaicinoid content of red pepper powder in a non-destructive and rapid method through visible and near infrared spectroscopy (VNIR). The developed system scans a well-leveled powder surface continuously to minimize the influence of...

Non-destructive and rapid prediction of moisture content in red pepper (Capsicum annuum L.) powder using near-infrared spectroscopy and a partial least squares regression model

USDA-ARS?s Scientific Manuscript database

Purpose: The aim of this study was to develop a technique for the non-destructive and rapid prediction of the moisture content in red pepper powder using near-infrared (NIR) spectroscopy and a partial least squares regression (PLSR) model. Methods: Three red pepper powder products were separated in...

The High Resolution Powder Diffraction Beam Line at ESRF.

PubMed

Fitch, A N

2004-01-01

The optical design and performance of the high-resolution powder diffraction beam line BM16 at ESRF are discussed and illustrated. Some recent studies carried out on BM16 are described, including crystal structure solution and refinement, anomalous scattering, in situ measurements, residual strain in engineering components, investigation of microstructure, and grazing-incidence diffraction from surface layers. The beam line is built on a bending magnet, and operates in the energy range from 5 keV to 40 keV. After the move to an undulator source in 2002, it will benefit from an extented energy range up to 60 keV and increased flux and resolution. It is anticipated that enhancements to the data quality will be achieved, leading to the solution of larger crystal structures, and improvements in the accuracy of refined structures. The systematic exploitation of anisotropic thermal expansion will help reduce the effects of peak overlap in the analysis of powder diffraction data.

Application of powder X-ray diffraction in studying the compaction behavior of bulk pharmaceutical powders.

PubMed

Bandyopadhyay, Rebanta; Selbo, Jon; Amidon, Gregory E; Hawley, Michael

2005-11-01

This study investigates the effects of crystal lattice deformation on the powder X-ray diffraction (PXRD) patterns of compressed polycrystalline specimen (compacts/tablets) made from molecular, crystalline powders. The displacement of molecules and the corresponding adjustment of interplanar distances (d-spacings) between diffracting planes of PNU-288034 and PNU-177553, which have crystal habits with a high aspect ratio favoring preferred orientation during tableting, are demonstrated by shifts in the diffracted peak positions. The direction of shift in diffracted peak positions suggests a reduction of interplanar d-spacing in the crystals of PNU-288034 and PNU-177553 following compaction. There is also a general reduction of peak intensities following compression at the different compressive loads. The lattice strain representing the reduction in d-spacing is proportional to the original d-spacing of the uncompressed sample suggesting that, as with systems that obey a simple Hooke's law relationship, the further apart the planes of atoms/molecules within the lattice are, the easier it is for them to approach each other under compressive stresses. For a third model compound comprising more equant-shaped crystals of PNU-141659, the shift in diffracted peak positions are consistent with an expansion of lattice spacing after compression. This apparent anomaly is supported by the PXRD studies of the bulk powder consisting of fractured crystals where also, the shift in peak position suggests expansion of the lattice planes. Thus the crystals of PNU-141659 may be fracturing under the compressive loads used to produce the compacts. Additional studies are underway to relate the PXRD observations with the bulk tableting properties of these model compounds.

Dicoumarol complexes of Cu(II) based on 1,10-phenanthroline: Synthesis, X-ray diffraction studies, thermal behavior and biological evaluation

NASA Astrophysics Data System (ADS)

Dholariya, Hitesh R.; Patel, Ketan S.; Patel, Jiten C.; Patel, Kanuprasad D.

2013-05-01

A series of Cu(II) complexes containing dicoumarol derivatives and 1, 10-phenanthroline have been synthesized. Structural and spectroscopic properties of ligands were studied on the basis of mass spectra, NMR (1H and 13C) spectra, FT-IR spectrophotometry and elemental analysis, while physico-chemical, spectroscopic and thermal properties of mixed ligand complexes have been studied on the basis of infrared spectra, mass spectra, electronic spectra, powder X-ray diffraction, elemental analysis and thermogravimetric analysis. X-ray diffraction study suggested the suitable octahedral geometry for hexa-coordinated state. The kinetic parameters such as order of reaction (n), energy of activation (Ea), entropy (S*), pre-exponential factor (A), enthalpy (H*) and Gibbs free energy (G*) have been calculated using Freeman-Carroll method. Ferric-reducing antioxidant power (FRAP) of all complexes were measured. All the compounds were screened for their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogenes and Bacillus subtilis, while antifungal activity against Candida albicans and Aspergillus niger have been carried out. Also compounds against Mycobacterium tuberculosis shows clear enhancement in the anti-tubercular activity upon copper complexation.

Synthesis, crystal structure and characterization of a new organic-inorganic hybrid material 4-(ammonium methyl) pipyridinium hexachloro stanate (II) trihydrate

NASA Astrophysics Data System (ADS)

Lassoued, Mohamed Saber; Abdelbaky, Mohammed S. M.; Lassoued, Abdelmajid; Ammar, Salah; Gadri, Abdellatif; Ben Salah, Abdelhamid; García-Granda, Santiago

2018-03-01

The present paper undertakes the study of (C6H16N2) SnCl6·3H2O which is a new hybrid compound. It was prepared and characterized by single crystal X-ray diffraction, X-ray powder, Hirshfeld surface, Spectroscopy measurement, thermal study and photoluminescence properties. The single crystal X-ray diffraction studies revealed that the compound crystallizes in monoclinic Cc space group with cell parameters a = 8.3309(9) Å, b = 22.956(2) Å, c = 9.8381(9) Å, β = 101.334(9) ° and Z = 4. The atomic arrangement shows an alternation of organic and inorganic entities. The cohesion between these entities is performed via Nsbnd H⋯Cl, Nsbnd H⋯O, Osbnd H⋯Cl and Osbnd H⋯O hydrogen bonding to form a three-dimensional network. Hirshfeld surface analysis was used to investigate intermolecular interactions, as well 2D finger plots were conducted to reveal the contribution of these interactions in the crystal structure quantitatively. The X-ray powder is in agreement with the X-ray structure. Scanning electron microscope (SEM) was carried out. Furthermore, the room temperature infrared (IR) spectrum of the title compound was recorded and analyzed on the basis of data found in the literature. Solid state 13C NMR spectrum shows four signals, confirming the solid state structure determined by X-ray diffraction. Besides, the thermal analysis studies were performed, but no phase transition was found in the temperature range between 30 and 450 °C. The optical and PL properties of the compound were investigated in the solid state at room temperature and exhibited three bands at 348 and 401 cm-1 and a strong fluorescence at 480 nm.

Water-Free Rare Earth-Prussian Blue Type Analogues: Synthesis, Structure, Computational Analysis, and Magnetic Data of {Ln[superscript III](DMF)[subscript 6]Fe[superscript III](CN)[subcsript 6]}[subscript infinity] (Ln = Rare Earths Excluding Pm)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, Duane C.; Liu, Shengming; Chen, Xuenian

2009-11-04

Water-free rare earth(III) hexacyanoferrate(III) complexes, {l_brace}Ln(DMF){sub 6}({mu}-CN){sub 2}Fe(CN){sub 4}{r_brace}{sub {infinity}} (DMF = N,N-dimethylformamide; Ln = Sm, 1; Eu, 2; Gd, 3; Tb, 4; Dy, 5; Ho, 6; Er, 7; Tm, 8; Yb, 9; Lu, 10; Y, 11; La, 12; Ce, 13; Pr, 14; Nd, 15), were synthesized in dry DMF through the metathesis reactions of [(18-crown-6)K]{sub 3}Fe(CN){sub 6} with LnX{sub 3}(DMF){sub n} (X = Cl or NO{sub 3}). Anhydrous DMF solutions of LnX{sub 3}(DMF){sub n} were prepared at room temperature from LnCl{sub 3} or LnX{sub 3} {center_dot} nH{sub 2}O under a dynamic vacuum. All compounds were characterized by IR, X-raymore » powder diffraction (except for 10), and single crystal X-ray diffraction (except for 2, 7, 10). Infrared spectra reveal that a monotonic, linear relationship exists between the ionic radius of the lanthanide and the {nu}{sub {mu}-CN} stretching frequency of 1-10, 12-15 while 11 deviates slightly from the ionic radius relationship. X-ray powder diffraction data are in agreement with powder patterns calculated from single crystal X-ray diffraction results, a useful alternative for bulk sample confirmation when elemental analysis data are difficult to obtain. Eight-coordinate Ln(III) metal centers are observed for all structures. trans-cyanide units of [Fe(CN){sub 6}]{sup 3-} formed isocyanide linkages to Ln(III) resulting in one-dimensional polymeric chains. Structures of compounds 1-9 and 11 are isomorphous, crystallizing in the space group C2/c. Structures of compounds 12-15 are also isomorphous, crystallizing in the space group P2/n. One unique polymeric chain exists in the structures of 1-9 and 11 while two unique polymeric chains exist in structures of 12-15. One of the polymeric chains of 12-15 is similar to that observed for 1-9, 11 while the other is more distorted and has a shorter Ln-Fe distance. Magnetic susceptibility measurements for compounds 3-6, 8, 11 were performed on polycrystalline samples of the compounds.« less

An Inquiry-Based Project Focused on the X-Ray Powder Diffraction Analysis of Common Household Solids

ERIC Educational Resources Information Center

Hulien, Molly L.; Lekse, Jonathan W.; Rosmus, Kimberly A.; Devlin, Kasey P.; Glenn, Jennifer R.; Wisneski, Stephen D.; Wildfong, Peter; Lake, Charles H.; MacNeil, Joseph H.; Aitken, Jennifer A.

2015-01-01

While X-ray powder diffraction (XRPD) is a fundamental analytical technique used by solid-state laboratories across a breadth of disciplines, it is still underrepresented in most undergraduate curricula. In this work, we incorporate XRPD analysis into an inquiry-based project that requires students to identify the crystalline component(s) of…

Using Variable Temperature Powder X-Ray Diffraction to Determine the Thermal Expansion Coefficient of Solid MgO

ERIC Educational Resources Information Center

Corsepius, Nicholas C.; DeVore, Thomas C.; Reisner, Barbara A.; Warnaar, Deborah L.

2007-01-01

A laboratory exercise was developed by using variable temperature powder X-ray diffraction (XRD) to determine [alpha] for MgO (periclase)and was tested in the Applied Physical Chemistry and Materials Characterization Laboratories at James Madison University. The experiment which was originally designed to provide undergraduate students with a…

Analysis of macromolecules, ligands and macromolecule-ligand complexes

DOEpatents

Von Dreele, Robert B [Los Alamos, NM

2008-12-23

A method for determining atomic level structures of macromolecule-ligand complexes through high-resolution powder diffraction analysis and a method for providing suitable microcrystalline powder for diffraction analysis are provided. In one embodiment, powder diffraction data is collected from samples of polycrystalline macromolecule and macromolecule-ligand complex and the refined structure of the macromolecule is used as an approximate model for a combined Rietveld and stereochemical restraint refinement of the macromolecule-ligand complex. A difference Fourier map is calculated and the ligand position and points of interaction between the atoms of the macromolecule and the atoms of the ligand can be deduced and visualized. A suitable polycrystalline sample of macromolecule-ligand complex can be produced by physically agitating a mixture of lyophilized macromolecule, ligand and a solvent.

Host sensitized near-infrared emission in Nd3+ doped different alkaline-sodium-phosphate phosphors

NASA Astrophysics Data System (ADS)

Balakrishna, A.; Swart, H. C.; Kroon, R. E.; Ntwaeaborwa, O. M.

2018-04-01

Near-infrared (NIR) emitting phosphors of different alkaline based sodium-phosphate (MNa[PO4], where M = Mg, Ca, Sr and Ba were prepared by a conventional solution combustion method with fixed doping concentration of Nd3+ (1.0 mol%). The phosphors were characterized by powder X-ray diffraction, field emission scanning electron microscope, Fourier transform infrared spectroscopy, UV-vis spectroscopy and fluorescent spectrophotometry. The optical properties including reflectance, excitation and emission were investigated. The excitation spectra of the phosphors were characterized by a broadband extending from 450 to 900 nm. Upon excitation with a wavelength of 580 nm, the phosphor emits intensely infrared region at 872 nm, 1060 nm and 1325 nm which correspond to the 4F3/2 → 4I9/2, 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 transitions of Nd3+ ions and were found to vary for the different hosts. The strongest emission wavelength reaches 1060 nm. The most intense emission of Nd3+ was observed from Ca2+ incorporated host. The down conversion emissions of the material fall in the NIR region suggesting that the prepared phosphors have potential application in the development of photonic devices emitting in the NIR.

Application of a novel combination of near-infrared spectroscopy and a humidity-controlled 96-well plate to the characterization of the polymorphism of imidafenacin.

PubMed

Uchida, Hiroshi; Yoshinaga, Tokuji; Mori, Hirotoshi; Otsuka, Makoto

2010-11-01

This study aimed to apply a currently available chemometric near-infrared spectroscopy technique to the characterization of the polymorphic properties of drug candidates. The technique requires only small quantities of samples and is therefore applicable to drugs in the early stages of development. The combination of near-infrared spectroscopy and a patented 96-well plate divided into 32 individual, humidity-controlled, three-well compartments was used in the characterization of a hygroscopic drug, imidafenacin, which has two polymorphs and one pseudo-polymorph. Characterization was also conducted with powder X-ray diffraction and thermal analysis. The results were compared with those from routinely used conventional analyses. Both the microanalysis and conventional analysis successfully characterised the substance (transformation and relative stability among the two polymorphs and a pseudo-polymorph) depending on the storage conditions. Near-infrared spectroscopic analyses utilizing a humidity-controlled 96-well plate required only small amounts of the sample for characterization under the various conditions of relative humidity. Near-infrared microanalysis can be applied to polymorphic studies of small quantities of a drug candidate. The results also suggest that the method will predict the behaviors of a hygroscopic candidate in solid pharmaceutical preparations at the early stages of drug development. © 2010 The Authors. JPP © 2010 Royal Pharmaceutical Society of Great Britain.

The preparation of a plasmonically resonant VO2 thermochromic pigment.

PubMed

Bai, Huaping; Cortie, Michael B; Maaroof, Abbas I; Dowd, Annette; Kealley, Catherine; Smith, Geoffrey B

2009-02-25

Vanadium dioxide (VO(2)) undergoes a reversible metal-insulator transition, normally at approximately 68 degrees C. While the properties of continuous semi-transparent coatings of VO(2) are well known, there is far less information available concerning the potential use of discrete VO(2) nanoparticles as a thermochromic pigment in opaque coatings. Individual VO(2) nanoparticles undergo a localized plasmon resonance with near-infrared light at about 1100 nm and this resonance can be switched on and off by simply varying the temperature of the system. Therefore, incorporation of VO(2) nanoparticles into a coating system imbues the coating with the ability to self-adaptively modulate its own absorptive efficiency in the near-infrared. Here we examine the magnitude and control of this phenomenon. Prototype coatings are described, made using VO(2) powder produced by an improved process. The materials are characterized using calorimetry, x-ray diffraction, high-resolution scanning electron microscopy, transmission electron microscopy, and by measurement of optical properties.

Near-infrared photoluminescence in La0.98AlO3: 0.02Ln3+(Ln = Nd/Yb) for sensitization of c-Si solar cells

NASA Astrophysics Data System (ADS)

Sawala, N. S.; Koparkar, K. A.; Bajaj, N. S.; Omanwar, S. K.

2016-05-01

The host matrix LaAlO3 was synthesized by conventional solid state reaction method in which the Nd3+ ions and Yb3+ ions successfully doped at 2mol% concentrations. The phase purity was confirmed by X ray powder diffraction (XRD) method. The photoluminescence (PL) properties were studied by spectrophotometer in near infra red (NIR) and ultra violet visible (UV-VIS) region. The Nd3+ ion doped LaAlO3 converts a visible (VIS) green photon (587 nm) into near infrared (NIR) photon (1070 nm) while Yb3+ ion doped converts ultra violet (UV) photon (221 nm) into NIR photon (980 nm). The La0.98AlO3: 0.02Ln3+(Ln = Nd / Yb) can be potentiality used for betterment of photovoltaic (PV) technology. This result further indicates its potential application as a luminescence converter layer for enhancing solar cells performance.

A new sol-gel synthesis of 45S5 bioactive glass using an organic acid as catalyst.

PubMed

Faure, J; Drevet, R; Lemelle, A; Ben Jaber, N; Tara, A; El Btaouri, H; Benhayoune, H

2015-02-01

In this paper a new sol-gel approach was explored for the synthesis of the 45S5 bioactive glass. We demonstrate that citric acid can be used instead of the usual nitric acid to catalyze the sol-gel reactions. The substitution of nitric acid by citric acid allows to reduce strongly the concentration of the acid solution necessary to catalyze the hydrolysis of silicon and phosphorus alkoxides. Two sol-gel powders with chemical compositions very close to that of the 45S5 were obtained by using either a 2M nitric acid solution or either a 5mM citric acid solution. These powders were characterized and compared to the commercial Bioglass®. The surface properties of the two bioglass powders were assessed by scanning electron microscopy (SEM) and by Brunauer-Emmett-Teller method (BET). The Fourier transformed infrared spectroscopy (FTIR) and the X-ray diffraction (XRD) revealed a partial crystallization associated to the formation of crystalline phases on the two sol-gel powders. The in vitro bioactivity was then studied at the key times during the first hours of immersion into acellular Simulated Body Fluid (SBF). After 4h immersion into SBF we clearly demonstrate that the bioactivity level of the two sol-gel powders is similar and much higher than that of the commercial Bioglass®. This bioactivity improvement is associated to the increase of the porosity and the specific surface area of the powders synthesized by the sol-gel process. Moreover, the nitric acid is efficiently substituted by the citric acid to catalyze the sol-gel reactions without alteration of the bioactivity of the 45S5 bioactive glass. Copyright © 2014 Elsevier B.V. All rights reserved.

Application of Powder Diffraction Methods to the Analysis of the Atomic Structure of Nanocrystals: The Concept of the Apparent Lattice Parameter (ALP)

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Gierlotka, S.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Weber, H.-P.; Palosz, W.; Curreri, Peter A. (Technical Monitor)

2002-01-01

The applicability of standard methods of elaboration of powder diffraction data for determination of the structure of nano-size crystallites is analysed. Based on our theoretical calculations of powder diffraction data we show, that the assumption of the infinite crystal lattice for nanocrystals smaller than 20 nm in size is not justified. Application of conventional tools developed for elaboration of powder diffraction data, like the Rietveld method, may lead to erroneous interpretation of the experimental results. An alternate evaluation of diffraction data of nanoparticles, based on the so-called 'apparent lattice parameter' (alp) is introduced. We assume a model of nanocrystal having a grain core with well-defined crystal structure, surrounded by a surface shell with the atomic structure similar to that of the core but being under a strain (compressive or tensile). The two structural components, the core and the shell, form essentially a composite crystal with interfering, inseparable diffraction properties. Because the structure of such a nanocrystal is not uniform, it defies the basic definitions of an unambiguous crystallographic phase. Consequently, a set of lattice parameters used for characterization of simple crystal phases is insufficient for a proper description of the complex structure of nanocrystals. We developed a method of evaluation of powder diffraction data of nanocrystals, which refers to a core-shell model and is based on the 'apparent lattice parameter' methodology. For a given diffraction pattem, the alp values are calculated for every individual Bragg reflection. For nanocrystals the alp values depend on the diffraction vector Q. By modeling different a0tomic structures of nanocrystals and calculating theoretically corresponding diffraction patterns using the Debye functions we showed, that alp-Q plots show characteristic shapes which can be used for evaluation of the atomic structure of the core-shell system. We show, that using a simple model of a nanocrystal with spherical shape and centro-symmetric strain at the surface shell we obtain theoretical alp-Q values which match very well the alp-Q plots determined experimentally for Sic, GaN, and diamond nanopowders. The theoretical models are defined by the lattice parameter of the grain core, thickness of the surface shell, and the magnitude and distribution of the strain field in the surface shell. According to our calculations, the part of the diffraction pattern measured at relatively low diffraction vectors Q (below 10/angstrom) provides information on the surface strain, whle determination of the lattice parameters in the grain core requires measurements at large Q-values (above 15 - 20/angstrom).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frølich, S.; Leemreize, H.; Jakus, A.

A model sample consisting of two different hydroxyapatite (hAp) powders was used as a bone phantom to investigate the extent to which X-ray diffraction tomography could map differences in hAp lattice constants and crystallite size. The diffraction data were collected at beamline 1-ID, the Advanced Photon Source, using monochromatic 65 keV X-radiation, a 25 × 25 µm pinhole beam and translation/rotation data collection. The diffraction pattern was reconstructed for each volume element (voxel) in the sample, and Rietveld refinement was used to determine the hAp lattice constants. The crystallite size for each voxel was also determined from the 00.2 hApmore » diffraction peak width. The results clearly show that differences between hAp powders could be measured with diffraction tomography.« less

Photon up-conversion production in Tb{sup 3+}–Yb{sup 3+} co-doped CaF{sub 2} phosphors prepared by combustion synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rakov, Nikifor, E-mail: nikifor.gomez@univasf.edu.br; Guimarães, Renato B.; Maciel, Glauco S., E-mail: glauco@if.uff.br

2016-02-15

Graphical abstract: Up-conversion luminescence from Tb{sup 3+} obtained by energy transfer from Yb{sup 3+} pairs in CaF{sub 2} powder prepared by combustion synthesis. - Highlights: • Calcium fluoride (CaF{sub 2}) powders were prepared by combustion synthesis. • Rare-earth ions doped in this material were found in interstitial sites. • Cooperative up-conversion was observed in Tb{sup 3+}:Yb{sup 3+}:CaF{sub 2} powder. • Energy transfer between Tb{sup 3+} and pairs of Yb{sup 3+} was analyzed using rate equations. - Abstract: Calcium fluoride (CaF{sub 2}) crystalline powders were successfully prepared by the combustion synthesis method. The powder material containing luminescent rare-earth ions, more specificallymore » terbium (Tb{sup 3+}) and ytterbium (Yb{sup 3+}), was studied by X-ray diffraction, scanning electronic microscopy and optical spectroscopy. These ions are allocated in charge compensated interstitial positions of tetragonal (C{sub 4v}) and trigonal (C{sub 3v}) symmetry sites of the cubic (O{sub h}) CaF{sub 2} lattice. Up-conversion (UC) luminescence in Tb{sup 3+} was achieved using a low power diode laser operating at 975 nm. Tb{sup 3+} is insensitive to near-infrared radiation but UC can be achieved via energy transfer from pairs of Yb{sup 3+} ions to Tb{sup 3+} ions. The UC luminescence dynamics of Tb{sup 3+} was used to study the energy transfer mechanism.« less

On the nature and origin of the oxalate package in Solanum sisymbriifolium anthers.

PubMed

Burrieza, Hernán Pablo; López-Fernández, María Paula; Láinez, Verónica; Montenegro, Teresita; Maldonado, Sara

2010-11-01

This is a detailed study carried out in Solanum sisymbriifolium Lam. on the development of the circular cell cluster (CCC) during crystal deposition, as well as the composition of the crystals. Light microscopy and scanning and transmission electron microscopy (TEM) were used to characterize tissue throughout anther development. Energy dispersive X-ray analysis (EDAX) allowed the determination of the elemental composition of crystals that form in the CCC region, and infrared and x-ray diffraction analysis were used to specify the crystal salt composition. TEM analysis revealed that the crystals originated simultaneously within the vacuoles in association with a paracrystalline protein. Prior to the appearance of protein within vacuoles, protein paracrystals were visible in both rough endoplasmic reticulum and vesicles with ribosomes on their membranes. In vacuoles, paracrystals constitute nucleation sites for druse crystals formation. EDAX revealed that C, O, and Ca were the main elements, and K, Cl, Mg, P, S, and Si, the minor elements. X-ray powder diffraction of crystals detected the predominant presence of calcium oxalate, but also vestiges of calcite, quartz, and sylvite. The calcium oxalate coexisted in the three chemical forms, that is, whewellite, weddellite, and caoxite. Infrared spectrophotometry identified bands that characterize O-C-O, H-O, C-H bonds, all of calcium oxalate, and Si-O-Si, of quartz. These results were compared with studies of anthers carried out in other Solanaceae genera.

Synthesis, characterization and photoluminescence properties of Bi³⁺ co-doped CaSiO₃:Eu³⁺ nanophosphor.

PubMed

Kumar, M Madesh; Krishna, R Hari; Nagabhushana, B M; Shivakumara, C

2015-03-15

Ceramic luminescent powders with the composition Ca(0.96-x)Eu0.04Bi(x)SiO3 (x=0.01-0.05) were prepared by solution combustion method. The nanopowders are characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and photoluminescence (PL) techniques. PXRD patterns of calcined (950°C for 3h) Ca(0.96-x)Eu0.04Bi(x)SiO3 powders exhibit monoclinic phase with mean crystallite sizes ranging from 28 to 48 nm. SEM micrographs show the products are foamy, agglomerated and fluffy in nature due to the large amount of gases liberated during combustion reaction. TEM micrograph shows the crystalline characteristics of the nanoparticles. Upon 280 nm excitation, the photoluminescence of the Ca(0.96-x)Eu0.04Bi(x)SiO3 particles show red emission at 611 nm corresponding to 5D0→7F2 transition. It is observed that PL intensity increases with Bi(3+) concentration. Our work demonstrates very interesting energy transfer from Bi(3+) to Eu(3+) in CaSiO3 host. Copyright © 2014 Elsevier B.V. All rights reserved.

Methanol steam reforming over Ni-CeO 2 model and powder catalysts: Pathways to high stability and selectivity for H 2/CO 2 production

DOE PAGES

Liu, Zongyuan; Yao, Siyu; Johnston-Peck, Aaron; ...

2017-08-25

Here, nickel-ceria has been reported as a very good catalysts for the reforming of methane. Here, the methanol steam reforming reaction on both powder (Ni-CeO 2) and model (Ni-CeO 2-x(111)) catalysts was investigated. The active phase evolution and surface species transformation on powder catalysts were studied via in situ X-ray diffraction (XRD) and diffuse reflectance infrared transform spectroscopy (DRIFTS). Phase transitions of NiO → NiC → Ni and CeO 2 → CeO 2-x were observed during the reaction. The simultaneous production of H 2/CO 2 demonstrates that the active phase of the catalysts contains metallic Ni supported over partially reducedmore » ceria. The DRIFTS experiments indicate that a methoxy to formate transition is associated with the reduction of ceria whereas the formation of carbonate species results from the presence of metallic Ni. A study of the reaction of methanol with Ni-CeO 2-x(111) by X-ray photoelectron spectroscopy (XPS) points to the essential role of metal-support interactions in an oxygen transfer from ceria to Ni that contributes to the high selectivity of the catalysts.« less

Starch-based polyurethane/CuO nanocomposite foam: Antibacterial effects for infection control.

PubMed

Ashjari, Hamid Reza; Dorraji, Mir Saeed Seyed; Fakhrzadeh, Vahid; Eslami, Hosein; Rasoulifard, Mohammad Hossein; Rastgouy-Houjaghan, Mehrdad; Gholizadeh, Pourya; Kafil, Hossein Samadi

2018-05-01

In the present study, a new method for the synthesis of the open cell flexible polyurethane foams (PUFs) was developed by using starch powder and the modification of closed cell foam formulation. Starch is the second largest polymeric carbohydrate as a macromolecule on this planet with a large number of glucose units. Copper oxide nanoparticles (CuO NPs) were synthesized by thermal degradation method at different temperatures of 400, 600 and 800 °C as antimicrobial agents. The antimicrobial activity of CuO NPs and commercial CuO powder against the main causes of hospital infections were tested. CuO 600 was the most effective antimicrobial agent and enhanced polymer matrix tensile strength with starch powder as new polyurethane foams (PUFs) cell opener with high tensile strength. The effects of parameters on tensile strength were optimized using response surface methodology (RSM). CuO NPs and PUF had optimal conditions and were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Foam synthesized at the optimal conditions had an open cell structure with high tensile strength and efficient antimicrobial activity that made them suitable to be used as an antimicrobial hospital mattress to control hospital infections. Copyright © 2018 Elsevier B.V. All rights reserved.

Preparation and characterization of selenite substituted hydroxyapatite.

PubMed

Ma, Jun; Wang, Yanhua; Zhou, Lei; Zhang, Shengmin

2013-01-01

Selenite-substituted hydroxyapatite (Se-HA) with different Se/P ratios was synthesized by a co-precipitation method, using sodium selenite (Na2SeO3) as a Se source. Selenium has been incorporated into the hydroxyapatite lattice by partially replacing phosphate (PO4(3-)) groups with selenite (SeO3(2-)) groups. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) techniques reveal that substitutions of phosphate groups by selenite groups cause lower carbonate groups occupying at phosphate sites and change the lattice parameters of hydroxyapatite. The powders obtained are nano-crystalline hydroxyapatite when the Se/P ratios are not more than 0.1. The particle shape of Se-HA has not been altered compared with selenite-free hydroxyapatite but Se-incorporation reduces the crystallite size. The crystallinity was reduced as the Se/P ratios increased until amorphous phase (Se/P=0.3) appeared in the Se-HA powder obtained, and then another crystal phase presented as calcium selenite hydrate (Se/P=10). In addition, the sintering tests show that the Se-HA powders with the Se/P ratio of 0.1 have thermal stability at 900 °C for 2 h; hence they have great potential in the fabrication of bone repair scaffolds. Copyright © 2012 Elsevier B.V. All rights reserved.

Thermal and ultrasonic influence in the formation of nanometer scale hydroxyapatite bio-ceramic

PubMed Central

Poinern, GJE; Brundavanam, R; Le, X Thi; Djordjevic, S; Prokic, M; Fawcett, D

2011-01-01

Hydroxyapatite (HAP) is a widely used biocompatible ceramic in many biomedical applications and devices. Currently nanometer-scale forms of HAP are being intensely investigated due to their close similarity to the inorganic mineral component of the natural bone matrix. In this study nano-HAP was prepared via a wet precipitation method using Ca(NO3)2 and KH2PO4 as the main reactants and NH4OH as the precipitator under ultrasonic irradiation. The Ca/P ratio was set at 1.67 and the pH was maintained at 9 during the synthesis process. The influence of the thermal treatment was investigated by using two thermal treatment processes to produce ultrafine nano-HAP powders. In the first heat treatment, a conventional radiant tube furnace was used to produce nano-particles with an average size of approximately 30 nm in diameter, while the second thermal treatment used a microwave-based technique to produce particles with an average diameter of 36 nm. The crystalline structure and morphology of all nanoparticle powders produced were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). Both thermal techniques effectively produced ultrafine powders with similar crystalline structure, morphology and particle sizes. PMID:22114473

Synthesis of nano-sized ZnO particles by co-precipitation method with variation of heating time

DOE Office of Scientific and Technical Information (OSTI.GOV)

Purwaningsih, S. Y., E-mail: sriyanisaputri@gmail.com; Pratapa, S.; Triwikantoro

Zinc oxide powders have been synthesized by a co-precipitation method at low temperature (85 °C), using zinc acetate dihydrate, ammonia, hydrochloric acid solutions as the reactants. A number of process parameters such as reaction temperature, solution basicity or pH and heating time are the main factors affecting the morphology and physical properties of the ZnO nanostructures. In this work the effect of heating time on the morphology and particles size were studied. The as-synthesized ZnO powders were characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques. The samples were also analyzed using Fourier transform infrared (FTIR). Rietveld refinementmore » of XRD data confirms that ZnO crystallizes in the hexagonal wurtzite structure with high degree of purity and the (101) plane predominant. The XRD results show that the average crystallite sizes were about 66, 27 and 12 nm for 3, 4 and 5 h of heating times, respectively. The XRD analysis indicated that a fraction of nano-sized ZnO powders were in the form of aggregates, which was also verified by TEM image. The TEM photograph demonstrated that the nano-sized ZnO particles were a pseudo-spherical shape.« less

Methanol steam reforming over Ni-CeO 2 model and powder catalysts: Pathways to high stability and selectivity for H 2/CO 2 production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Zongyuan; Yao, Siyu; Johnston-Peck, Aaron

Here, nickel-ceria has been reported as a very good catalysts for the reforming of methane. Here, the methanol steam reforming reaction on both powder (Ni-CeO 2) and model (Ni-CeO 2-x(111)) catalysts was investigated. The active phase evolution and surface species transformation on powder catalysts were studied via in situ X-ray diffraction (XRD) and diffuse reflectance infrared transform spectroscopy (DRIFTS). Phase transitions of NiO → NiC → Ni and CeO 2 → CeO 2-x were observed during the reaction. The simultaneous production of H 2/CO 2 demonstrates that the active phase of the catalysts contains metallic Ni supported over partially reducedmore » ceria. The DRIFTS experiments indicate that a methoxy to formate transition is associated with the reduction of ceria whereas the formation of carbonate species results from the presence of metallic Ni. A study of the reaction of methanol with Ni-CeO 2-x(111) by X-ray photoelectron spectroscopy (XPS) points to the essential role of metal-support interactions in an oxygen transfer from ceria to Ni that contributes to the high selectivity of the catalysts.« less

Comparison of Physical-chemical and Mechanical Properties of Chlorapatite and Hydroxyapatite Plasma Sprayed Coatings

PubMed Central

Demnati, Imane; Grossin, David; Marsan, Olivier; Bertrand, Ghislaine; Collonges, Gérard; Combes, Christèle; Parco, Maria; Braceras, Inigo; Alexis, Joel; Balcaen, Yannick; Rey, Christian

2015-01-01

Chlorapatite can be considered a potential biomaterial for orthopaedic applications. Its use as plasma-sprayed coating could be of interest considering its thermal properties and particularly its ability to melt without decomposition unlike hydroxyapatite. Chlorapatite (ClA) was synthesized by a high-temperature ion exchange reaction starting from commercial stoichiometric hydroxyapatites (HA). The ClA powder showed similar characteristics as the original industrial HA powder, and was obtained in the monoclinic form. The HA and ClA powders were plasma-sprayed using a low-energy plasma spraying system with identical processing parameters. The coatings were characterized by physical-chemical methods, i.e. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy, including distribution mapping of the main phases detected such as amorphous calcium phosphate (ACP), oxyapatite (OA), and HA or ClA. The unexpected formation of oxyapatite in ClA coatings was assigned to a side reaction with contaminating oxygenated species (O2, H2O). ClA coatings exhibited characteristics different from HA, showing a lower content of oxyapatite and amorphous phase. Although their adhesion strength was found to be lower than that of HA coatings, their application could be an interesting alternative, offering, in particular, a larger range of spraying conditions without formation of massive impurities. PMID:25893015

A novel particle engineering technology to enhance dissolution of poorly water soluble drugs: spray-freezing into liquid.

PubMed

Rogers, True L; Nelsen, Andrew C; Hu, Jiahui; Brown, Judith N; Sarkari, Marazban; Young, Timothy J; Johnston, Keith P; Williams, Robert O

2002-11-01

A novel cryogenic spray-freezing into liquid (SFL) process was developed to produce microparticulate powders consisting of an active pharmaceutical ingredient (API) molecularly embedded within a pharmaceutical excipient matrix. In the SFL process, a feed solution containing the API was atomized beneath the surface of a cryogenic liquid such that the liquid-liquid impingement between the feed and cryogenic liquids resulted in intense atomization into microdroplets, which were frozen instantaneously into microparticles. The SFL micronized powder was obtained following lyophilization of the frozen microparticles. The objective of this study was to develop a particle engineering technology to produce micronized powders of the hydrophobic drug, danazol, complexed with hydroxypropyl-beta-cyclodextrin (HPbetaCD) and to compare these SFL micronized powders to inclusion complex powders produced from other techniques, such as co-grinding of dry powder mixtures and lyophilization of bulk solutions. Danazol and HPbetaCD were dissolved in a water/tetrahydrofuran cosolvent mixture prior to SFL processing or slow freezing. Identical quantities of the API and HPbetaCD used in the solutions were co-ground in a mortar and pestle and blended to produce a co-ground physical mixture for comparison. The powder samples were characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), scanning electron microscopy, surface area analysis, and dissolution testing. The results provided by DSC, XRD, and FTIR suggested the formation of inclusion complexes by both slow-freezing and SFL. However, the specific surface area was significantly higher for the latter. Dissolution results suggested that equilibration of the danazol/HPbetaCD solution prior to SFL processing was required to produce the most soluble conformation of the resulting inclusion complex following SFL. SFL micronized powders exhibited better dissolution profiles than the slowly frozen aggregate powder. Results indicated that micronized SFL inclusion complex powders dissolved faster in aqueous dissolution media than inclusion complexes formed by conventional techniques due to higher surface areas and stabilized inclusion complexes obtained by ultra-rapid freezing.

Entrainment of lactose inhalation powders: a study using laser diffraction.

PubMed

Watling, C P; Elliott, J A; Cameron, R E

2010-07-11

We have investigated the mechanism of entrainment of lactose inhalation blends released from a dry powder inhaler using a diffraction particle size analyser (Malvern Spraytec). Whether a powder blend entrains as a constant stream of powder (the "erosion" mechanism) or as a few coarse plugs (the "fracture" mechanism) was found by comparing transmission data with particle size information. This technique was then applied to a lactose grade with 0, 5 and 10wt% added fine particles. As the wt% fines increased, the entrainment mechanism was found to change from a mild fracture, consisting of multiple small plugs, to more severe fracture with fewer plugs. The most severe fracture mechanism consisted of either the powder reservoir emptying as a single plug, or of the reservoir emptying after a delay of the order of 0.1s due to the powder sticking to its surroundings. Further to this, three different inhalation grades were compared, and the severity of the fracture was found to be inversely proportional to the flowability of the powder (measured using an annular ring shear tester). By considering the volume of aerosolised fine particles in different blends it was determined that the greater the volume of fines added to a powder, the smaller the fraction of fines that were aerosolised. This was attributed to different behaviour when fines disperse from carrier particles compared with when they disperse from agglomerates of fines. In summary, this paper demonstrates how laser diffraction can provide a more detailed analysis of an inhalation powder than just its size distribution. 2010. Published by Elsevier B.V. All rights reserved.

Real-time powder diffraction studies of energy materials under non-equilibrium conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, Vanessa K.; Auckett, Josie E.; Pang, Wei-Kong

Energy materials form the central part of energy devices. An essential part of their function is the ability to reversibly host charge or energy carriers, and analysis of their phase composition and structure in real time under non-equilibrium conditions is mandatory for a full understanding of their atomic-scale functional mechanism. Real-time powder diffraction is increasingly being applied for this purpose, forming a critical step in the strategic chemical engineering of materials with improved behaviour. This topical review gives examples of real-time analysis using powder diffraction of rechargeable battery electrodes and porous sorbent materials used for the separation and storage ofmore » energy-relevant gases to demonstrate advances in the insights which can be gained into their atomic-scale function.« less

Real-time powder diffraction studies of energy materials under non-equilibrium conditions

PubMed Central

Peterson, Vanessa K.; Auckett, Josie E.; Pang, Wei-Kong

2017-01-01

Energy materials form the central part of energy devices. An essential part of their function is the ability to reversibly host charge or energy carriers, and analysis of their phase composition and structure in real time under non-equilibrium conditions is mandatory for a full understanding of their atomic-scale functional mechanism. Real-time powder diffraction is increasingly being applied for this purpose, forming a critical step in the strategic chemical engineering of materials with improved behaviour. This topical review gives examples of real-time analysis using powder diffraction of rechargeable battery electrodes and porous sorbent materials used for the separation and storage of energy-relevant gases to demonstrate advances in the insights which can be gained into their atomic-scale function. PMID:28989711

Structural phase transition in d-benzil characterised by capacitance measurements and neutron powder diffraction

NASA Astrophysics Data System (ADS)

Goossens, D. J.; Wu, Xiaodong; Prior, M.

2005-12-01

The ferroelectric phase transition in deuterated benzil, C 14H 10O 2, has been studied using capacitance measurements and neutron powder diffraction. Hydrogenous benzil shows a phase transition at 83.5 K from a high temperature P3 121 phase to a cell-doubled P2 1 phase. The phase transition in d-benzil occurs at 88.1 K, a small isotope effect. Neutron powder diffraction was consistent with a low temperature phase of space group P2 1. Upon deuteration the transition remained first-order and the dynamics of the phenyl ring dominated the behaviour. The isotope effect can be attributed to the difference in mass and moment of inertia between C 6H 5 and C 6D 5.

Room Temperature Ferromagnetism of Fe Doped Indium Tin Oxide Based on Dispersed Fe3O4 Nanoparticles

NASA Astrophysics Data System (ADS)

Okada, Koichi; Kohiki, Shigemi; Nishi, Sachio; Shimooka, Hirokazu; Deguchi, Hiroyuki; Mitome, Masanori; Bando, Yoshio; Shishido, Toetsu

2007-09-01

Transmission electron microscopy revealed that Fe3O4 nanoparticles with diameter of ≈200 nm dispersed in Fe doped indium tin oxide (Fe@ITO) powders exhibiting co-occurrence of room temperature ferromagnetism and superparamagnetism. Although we observed no X-ray diffraction peak from Fe related compounds for Fe0.19@ITO (ITO: In1.9Sn0.1O3) powders, the powders showed both hysteresis loop in field dependent magnetization at 300 K and divergence of zero-field-cooled magnetization from field-cooled magnetization. Scanning transmission electron microscopy with energy dispersive X-ray spectroscopy demonstrated that the nanoparticle with diameter of ≈200 nm consists of Fe and oxygen. Transmission electron diffraction revealed that crystal structure of the nanoparticle is inverse spinel type Fe3O4. The Fe3O4 crystalline phase by electron diffraction is consistent with the saturation magnetization of 1.3 μB/Fe and magnetic anomaly at ≈110 K observed for the powders.

Synthesis, growth, structural, spectroscopic and optical studies of a new semiorganic nonlinear optical crystal: L-valine hydrochloride.

PubMed

Kirubavathi, K; Selvaraju, K; Valluvan, R; Vijayan, N; Kumararaman, S

2008-04-01

Single crystals of a new semiorganic nonlinear optical (NLO) material, L-valine hydrochloride (LVHCl), having dimensions up to 20 mm x 6 mm x 4 mm have been grown by slow evaporation solution growth technique. Single crystal X-ray diffraction studies confirm that the grown crystal belongs to the monoclinic system. The functional groups presented in the crystal were confirmed by Fourier transform infrared (FTIR) technique. Optical transmission spectrum shows very low absorption in the entire visible region. Differential thermal and thermogravimetric analyses confirmed that the crystal is stable up to 211 degrees C. The powder second harmonic generation (SHG) efficiency of LVHCl is 1.7 times efficient as potassium dihydrogen phosphate (KDP).

Adsorption properties of biomass-based activated carbon prepared with spent coffee grounds and pomelo skin by phosphoric acid activation

NASA Astrophysics Data System (ADS)

Ma, Xiaodong; Ouyang, Feng

2013-03-01

Activated carbon prepared from spent coffee grounds and pomelo skin by phosphoric acid activation had been employed as the adsorbent for ethylene and n-butane at room temperature. Prepared activated carbon was characterized by means of nitrogen adsorption-desorption, X-ray powder diffraction, scanning electron microscope and Fourier transform infrared spectroscope. It was confirmed that pore structure played an important role during the adsorption testes. Adsorption isotherms of ethylene and n-butane fitted well with Langmuir equation. The prepared samples owned better adsorption capacity for n-butane than commercial activated carbon. Isosteric heats of adsorptions at different coverage were calculated through Clausius-Clapeyron equation. Micropore filling effect was explained in a thermodynamic way.

Determination of residual solvents and investigation of their effect on ampicillin trihydrate crystal structure.

PubMed

Nojavan, Saeed; Ghassempour, Alireza; Bashour, Yosef; Darbandi, Masoud Khalilian; Ahmadi, Seyyed Hamid

2005-01-04

In the present work, the relationship between residual solvents concentration and ampicillin trihydrate crystals stability has been investigated. The amounts of residual solvents determined by GC, X-ray powder diffraction (XRPD) and Fourier transform infrared spectroscopy (FT-IR) were used for characterization of solid state. The obtained results have shown good relationship between concentration of methylene chloride (as a critical residue solvent) and degree of ampicillin trihydrate crystallinity. As with the increasing methylene chloride concentration in the sample the degree of crystallinity decreased after stability test. From this relationship, critical concentration of methylene chloride into the ampicillin trihydrate is obtained and the results can be used for improving the large-scale production of ampicillin trihydrate.

Surface modification of boron nitride nanosheets by polyelectrolytes via atom transfer radical polymerization

NASA Astrophysics Data System (ADS)

Wu, Yuanpeng; Guo, Meiling; Liu, Guanfei; Xue, Shishan; Xia, Yuanmeng; Liu, Dan; Lei, Weiwei

2018-04-01

In this study, the surface modification of boron nitride nanosheets (BNNSs) with poly 2-acrylamido-2-methyl- propanesulfonate (PAMPS) brushes is achieved through electron transfer atom transfer radical polymerization (ARGET ATRP). BNNSs surface was first modified with α-bromoisobutyryl bromide (BIBB) via hydroxyl groups, then PAMPS brushes were grown on the surface through ARGET ATRP. Polyelectrolyte brushes modified BNNSs were further characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyses (TGA), x-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The concentraction of water-dispersion of BNNSs have been enhanced significantly by PAMPS and the high water-dispersible functional BNNSs/PAMPS composites are expected to have potential applications in biomedical and thermal management in electronics.

Effects for rapid conversion from abalone shell to hydroxyapaptite nanosheets by ionic surfactants.

PubMed

Zhong, Shengnan; Wen, Zhenliang; Chen, Jingdi; Li, Qian; Shi, Xuetao; Ding, Shinnjyh; Zhang, Qiqing

2017-08-01

Hydroxyapatite (HAP) has been widely used for repairing or substituting human hard tissues. In this paper, two typical ionic surfactants, cation hexadecyltrimethylammonium bromide (CTAB) and anion sodium dodecyl sulfate (SDS), were used for rapid conversion of HAP from abalone shell. From field emission scanning electron microscopy (FESEM), the prepared HAP is flake-like structure. From X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermal analysis, these samples contain a small amount of calcium carbonate whose content gradually increases by increasing the surfactants. The results showed that the HAP formed fast on the layer of abalone shell powder with the assistance of CTAB and SDS. Copyright © 2017 Elsevier B.V. All rights reserved.

Plasma induced grafting carboxymethyl cellulose on multiwalled carbon nanotubes for the removal of UO(2)(2+) from aqueous solution.

PubMed

Shao, Dadong; Jiang, Zhongqing; Wang, Xiangke; Li, Jiaxing; Meng, Yuedong

2009-01-29

Carboxymethyl cellulose (CMC) is grafted on multiwalled carbon nanotubes (MWCNT) by using plasma techniques. The CMC grafted MWCNT (MWCNT-g-CMC) is characterized by using Fourier transform infrared spectra (FT-IR), Raman spectra, powder X-ray diffraction (XRD), thermogravimetric analysis (TGA)-differential thermal analysis (DTA), scanning electron microscopy (SEM), and N(2)-BET methods in detail. The application of MWCNT-g-CMC in the removal of UO(2)(2+) from aqueous solution is investigated. MWCNT-g-CMC has much higher sorption ability in the removal of UO(2)(2+) than raw MWCNT. The MWCNT-g-CMC is a suitable material in the preconcentration and solidification of heavy metal ions from large volume of aqueous solutions.

Design of high-efficiency diffractive optical elements towards ultrafast mid-infrared time-stretched imaging and spectroscopy

NASA Astrophysics Data System (ADS)

Xie, Hongbo; Ren, Delun; Wang, Chao; Mao, Chensheng; Yang, Lei

2018-02-01

Ultrafast time stretch imaging offers unprecedented imaging speed and enables new discoveries in scientific research and engineering. One challenge in exploiting time stretch imaging in mid-infrared is the lack of high-quality diffractive optical elements (DOEs), which encode the image information into mid-infrared optical spectrum. This work reports the design and optimization of mid-infrared DOE with high diffraction-efficiency, broad bandwidth and large field of view. Using various typical materials with their refractive indices ranging from 1.32 to 4.06 in ? mid-infrared band, diffraction efficiencies of single-layer and double-layer DOEs have been studied in different wavelength bands with different field of views. More importantly, by replacing the air gap of double-layer DOE with carefully selected optical materials, one optimized ? triple-layer DOE, with efficiency higher than 95% in the whole ? mid-infrared window and field of view greater than ?, is designed and analyzed. This new DOE device holds great potential in ultrafast mid-infrared time stretch imaging and spectroscopy.

Mineral and Geochemical Classification From Spectroscopy/Diffraction Through Neural Networks

NASA Astrophysics Data System (ADS)

Ferralis, N.; Grossman, J.; Summons, R. E.

2017-12-01

Spectroscopy and diffraction techniques are essential for understanding structural, chemical and functional properties of geological materials for Earth and Planetary Sciences. Beyond data collection, quantitative insight relies on experimentally assembled, or computationally derived spectra. Inference on the geochemical or geophysical properties (such as crystallographic order, chemical functionality, elemental composition, etc.) of a particular geological material (mineral, organic matter, etc.) is based on fitting unknown spectra and comparing the fit with consolidated databases. The complexity of fitting highly convoluted spectra, often limits the ability to infer geochemical characteristics, and limits the throughput for extensive datasets. With the emergence of heuristic approaches to pattern recognitions though machine learning, in this work we investigate the possibility and potential of using supervised neural networks trained on available public spectroscopic database to directly infer geochemical parameters from unknown spectra. Using Raman, infrared spectroscopy and powder x-ray diffraction from the publicly available RRUFF database, we train neural network models to classify mineral and organic compounds (pure or mixtures) based on crystallographic structure from diffraction, chemical functionality, elemental composition and bonding from spectroscopy. As expected, the accuracy of the inference is strongly dependent on the quality and extent of the training data. We will identify a series of requirements and guidelines for the training dataset needed to achieve consistent high accuracy inference, along with methods to compensate for limited of data.

Combined synchrotron X-ray tomography and X-ray powder diffraction using a fluorescing metal foil.

PubMed

Kappen, P; Arhatari, B D; Luu, M B; Balaur, E; Caradoc-Davies, T

2013-06-01

This study realizes the concept of simultaneous micro-X-ray computed tomography and X-ray powder diffraction using a synchrotron beamline. A thin zinc metal foil was placed in the primary, monochromatic synchrotron beam to generate a divergent wave to propagate through the samples of interest onto a CCD detector for tomographic imaging, thus removing the need for large beam illumination and high spatial resolution detection. Both low density materials (kapton tubing and a piece of plant) and higher density materials (Egyptian faience) were investigated, and elemental contrast was explored for the example of Cu and Ni meshes. The viability of parallel powder diffraction using the direct beam transmitted through the foil was demonstrated. The outcomes of this study enable further development of the technique towards in situ tomography∕diffraction studies combining micrometer and crystallographic length scales, and towards elemental contrast imaging and reconstruction methods using well defined fluorescence outputs from combinations of known fluorescence targets (elements).

Synthesis and crystal structure determination of yttrium ultraphosphate YP 5O 14

NASA Astrophysics Data System (ADS)

Mbarek, A.; Graia, M.; Chadeyron, G.; Zambon, D.; Bouaziz, J.; Fourati, M.

2009-03-01

The crystal structure of monoclinic YP 5O 14 (space group C2/ c, a=12.919(2) Å, b=12.796(4) Å, c=12.457(2) Å, β=91.30(1)°, Z=8) has been refined from single-crystal X-ray diffraction data. Full-matrix least-squares refinement on F2 using 2249 independent reflections for 183 refinable parameters results in a final R value of 0.027 ( ωR=0.069). The structure is isotypic with HoP 5O 14. This structure is built up from infinite layers of PO 4 tetrahedra linked through isolated YO 8 polyhedra. The three-dimensional cohesion of the framework results from Y-O-P bridges. This crystal structure refinement leads to the calculated X-ray diffraction powder pattern of this monoclinic polymorph, which has been the starting point of a thorough study of the solid-state synthesis of this ultraphosphate. This investigation further leads to a better outstanding of features observed during the synthesis of powdered samples. The thermal behavior of this ultraphosphate has been studied by DTA and TGA analyses. The infrared and Raman spectroscopic characterizations have been carried out on polycrystalline samples. The luminescence properties of the Eu 3+ ion incorporated in the monoclinic C2/ c polymorph of YP 5O 14 as local structural probe show that in YP 5O 14: 5% Eu 3+ sample, the Eu 3+ ions are distributed over the two Y 3+ crystallographic sites of C 2 symmetry of this structure.

Agglomerated novel spray-dried lactose-leucine tailored as a carrier to enhance the aerosolization performance of salbutamol sulfate from DPI formulations.

PubMed

Molina, Carlos; Kaialy, Waseem; Chen, Qiao; Commandeur, Daniel; Nokhodchi, Ali

2017-12-19

Spray-drying allows to modify the physicochemical/mechanical properties of particles along with their morphology. In the present study, L -leucine with varying concentrations (0.1, 0.5, 1, 5, and 10% w/v) were incorporated into lactose monohydrate solution for spray-drying to enhance the aerosolization performance of dry powder inhalers containing spray-dried lactose-leucine and salbutamol sulfate. The prepared spray-dried lactose-leucine carriers were analyzed using laser diffraction (particle size), differential scanning calorimetry (thermal behavior), scanning electron microscopy (morphology), powder X-ray diffraction (crystallinity), Fourier transform infrared spectroscopy (interaction at molecular level), and in vitro aerosolization performance (deposition). The results showed that the efficacy of salbutamol sulfate's aerosolization performance was, in part, due to the introduction of L -leucine in the carrier, prior to being spray-dried, accounting for an increase in the fine particle fraction (FPF) of salbutamol sulfate from spray-dried lactose-leucine (0.5% leucine) in comparison to all other carriers. It was shown that all of the spray-dried carriers were spherical in their morphology with some agglomerates and contained a mixture of amorphous, α-lactose, and β-lactose. It was also interesting to note that spray-dried lactose-leucine particles were agglomerated during the spray-drying process to make coarse particles (volume mean diameter of 79 to 87 μm) suitable as a carrier in DPI formulations.

Studies on magnetic properties of chemically synthesized crystalline calcium ferrite nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Debnath, A., E-mail: debnathanimesh@gmail.com; Bera, A.; Saha, B.

Spinel-type ferrites have taken a very important role for modern electronic industry. Most of these ferrites exhibit low-loss dielectric properties, high resistivity, low eddy current and also high temperature ferromagnetism. Calcium ferrite is one such important metal oxide which is environmentally safe, chemically stable, low cost and greatly abundant. This outstanding material of calcium ferrite is synthesized by a simple chemical precipitation method using NaOH as the precipitating agent. Ferric chloride anhydrous (FeCl{sub 3}) and Calcium chloride dihydrate (CaCl{sub 2}.2H{sub 2}O) were used as iron and calcium sources respectively. The samples were heated at 200°C for 8h to obtain homogeneousmore » powder of Calcium ferrite. The powders were characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Transmission electrical microscopy (TEM), and Fourier transform infrared spectroscopic (FTIR) measurements. The polycrystalline nature of the sample was confirmed by X-ray diffraction study. The magnetic properties of the sample were investigated by vibrating sample magnetometer (VSM) measurements. Magnetization curve of the prepared sample depicts that as synthesized calcium ferrite nanoparticles have saturation magnetic moment of 1.74 emu/g and the coercivity of 35.08 Oe with superparamagnetic behavior. The synthesized calcium ferrite nanoparticles with such magnetic properties will be a candidate material for different applications in electronics and exploring its functionality in the field of recently developing semiconductor device physics and spintronics.« less

High surface area nanocrystalline hausmannite synthesized by a solvent-free route

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herrera-Miranda, Daniel; Ponrouch, Alexandre; Pons, Josefina

Highlights: ► High surface area Mn{sub 3}O{sub 4} nanoparticles obtained by a solvent-free low temperature route. ► 3,6,9-Trioxadecanoic acid allows to obtain nanocrystalline hausmannite. ► Tape casted electrodes show up to 300 mAh g{sup −1} capacity after more than 40 cycles at a C/3 rate. ► Upper cut off voltage strongly influences capacity retention upon cycling at high C rates. -- Abstract: Nanocrystalline high surface area Mn{sub 3}O{sub 4} powder was obtained at low temperature by a solvent-free route. The precursor was a mixture of manganese (II) acetate, 3,6,9-trioxadecanoic acid (TODA) and ammonium acetate that were intimately mixed by groundingmore » in an agate mortar. Nanocrystalline Mn{sub 3}O{sub 4} was obtained by thermal treatment at 120 °C. Powder X-ray diffraction, selected area electron diffraction, high resolution transmission electron microscopy, and Fourier transformed infrared characterization confirmed the formation of the hausmannite phase. The as-prepared mesoporous material has high specific surface area (120 m{sup 2} g{sup −1}). The performances of tape casted Mn{sub 3}O{sub 4} nanopowder electrodes were investigated as anode material for lithium ion batteries. High capacity values were achieved at diverse C rates. Capacity fading was found to be dependent on the upper cut off voltage, the presence of a plateau at 2.25 V vs. Li{sup +}/Li being detrimental for long term cyclability.« less

Detection of starch adulteration in onion powder by FT-NIR and FT-IR spectroscopy

USDA-ARS?s Scientific Manuscript database

Adulteration of onion powder with cornstarch was identified by Fourier transform near-infrared (FT-NIR) and Fourier transform infrared (FT-IR) spectroscopy. The reflectance spectra of 180 pure and adulterated samples (1–35 wt% starch) were collected and preprocessed to generate calibration and predi...

Penetration depth measurement of near-infrared hyperspectral imaging light for milk powder

USDA-ARS?s Scientific Manuscript database

The increasingly common application of near-infrared (NIR) hyperspectral imaging technique to the analysis of food powders has led to the need for optical characterization of samples. This study was aimed at exploring the feasibility of quantifying penetration depth of NIR hyperspectral imaging ligh...

Co-Precipitation Synthesis and Characterization of SrBi2Ta2O9 Ceramic

NASA Astrophysics Data System (ADS)

Afqir, Mohamed; Tachafine, Amina; Fasquelle, Didier; Elaatmani, Mohamed; Carru, Jean-Claude; Zegzouti, Abdelouahad; Daoud, Mohamed

2018-04-01

Strontium bismuth tantalate (SrBi2Ta2O9) was synthesized by a co-precipitation method. The sample was characterized by x-ray powder diffraction patterns (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results of the dielectric properties are reported at room temperature. No secondary phases were found while heating the powder at 850°C and the pure SrBi2Ta2O9 phase was formed, as revealed by XRD. The characteristic bands for SrBi2Ta2O9 were observed by FTIR at approximately 619 cm-1 and 810 cm-1. SEM micrographs for the sample displayed thin plate-like grains. The grain size was less than 1 μm and the crystallite size of about 24 nm. Dielectric response at room temperature shows that the SrBi2Ta2O9 ceramic has low loss values, and the flattening of the dielectric constant at higher frequencies. The observed Curie temperature is comparable with those reported in the literature.

Lanthanum cerate (La2Ce2O7): hydrothermal synthesis, characterization and optical properties

NASA Astrophysics Data System (ADS)

Khademinia, Shahin; Behzad, Mahdi

2015-03-01

La2Ce2O7 nano-powders were synthesized via a hydrothermal reaction in a deionized water (S 1) and in a 2 M NaOH aqueous solution (S 2) at 180 °C for 48 h. La(NO3)3·H2O and (NH4)2Ce(NO3)6 were used in the stoichiometric 1:1 La:Ce molar ratio as raw materials. The obtained materials were crystallized in a cubic crystal structure with space group. The synthesized materials were characterized by powder X-ray diffraction technique and Fourier-transform infrared spectroscopy. To investigate the effect of the basic solution on the morphology of the obtained materials, the morphologies of the synthesized materials were studied by field emission scanning electron microscopy technique. The technique showed that the morphology of La2Ce2O7 samples changed from grain to rod-like structure in presence of the basic solution. Cell parameter refinements showed that these parameters were larger for S2 than those for S 1. Photoluminescence and ultraviolet visible spectra of the synthesized nanomaterials were also investigated.

Fabrication and Properties of polyacrylic acid by ionic surfactant disturbance method

NASA Astrophysics Data System (ADS)

Lawan, S.; Osotchan, T.; Chuajiw, W.; Subannajui, K.

2017-09-01

The formation of polymeric materials can be achieved by several methods such as melting and casting, screw extrusion, cross-linking of resin or rubber in a mold, and so on. In this work, the polyacrylic acid is formed by using the emulsion disturbance method. Despite extensively used in the colour painting and coating industries, acrylic emulsion can be processed into a foam and powder configuration by a reaction between acrylic emulsion and salt. The solidification hardly changes the volume between liquid emulsion and solidified polymer which means the final structure of polyacrylic acid is filled with opened air cells. The opened air cell structure is confirmed by the result from scanning electron microscopy. The chemical analysis and crystallography of acrylic powder and foam are examined by Fourier-transform infrared spectroscopy and X-ray diffraction respectively. The phase transformation and Thermal stability are studied by differential scanning calorimetry and thermo gravimetric analysis. Moreover, the mechanical properties of acrylic foam were observed by tensile, compressive and hardness test. In addition to the basic property analysis, acrylic foam was also used in the particle filtration application.

Effect on dielectric, magnetic, optical and structural properties of Nd-Co substituted barium hexaferrite nanoparticles

NASA Astrophysics Data System (ADS)

Kaur, Talwinder; Kumar, Sachin; Bhat, Bilal Hamid; Want, Basharat; Srivastava, A. K.

2015-06-01

M-type barium hexaferrite [Ba1- x Nd x Co x Fe12- x O19 ( x = 0.0-0.5) (BNCM)] powders, synthesized using citrate precursor method, were heat treated at 900 °C for 5 h. The pattern of powders, when subjected to X-ray diffraction, shows the formation of M-type hexaferrite phase. The formation of BNCM, from thermogravimetric analysis/differential thermal analysis/derivative thermogravimetry, is observed to be at 440 °C. The presence of two prominent peaks near 430 and 580 cm-1 in Fourier transform infrared spectroscopy spectra indicates the formation of M-type hexaferrites. The M- H curves obtained from vibrating sample magnetometer were used to calculate saturation magnetization ( M S), retentivity ( M R), squareness ration and coercivity ( H C). UV-Vis NIR spectroscopy reveals that band gap depends on size of the crystallites. The dielectric constant is found to be high at low frequency and decreases with increase in frequency. This kind of behaviour is explained on the basis of Koop's phenomenological theory and Maxwell-Wagner theory.

Europium concentration effect on characteristics and luminescent properties of hydroxyapatite nanocrystalline powders

NASA Astrophysics Data System (ADS)

Nikolaev, Anton; Kolesnikov, Ilya; Frank-Kamenetskaya, Olga; Kuz'mina, Maria

2017-12-01

Series of Eu-apatites were synthesized by precipitation from aqueous solutions with the Eu/Ca atomic ratio from 0.5% to 5% at T = 90 °C. Resulting precipitates were studied using different experimental techniques including X-ray powder diffraction, infrared and raman spectroscopy, scanning elecrton microscopy, EDX and photoluminescent spectroscopy. Eu-doped Ca-deficit nanosized non-stoichiometric hydroxyapatite with high water content has been obtained throughout the experiment. Europium content in the synthesized apatites reaches 0.24 apfu (Eu/Ca = 2.5%). Relations between Eu content is the solution and precipitate have been established. It was shown that Eu-monacite starts to precipitate as secondary phase at Eu/Ca ratio in starting solution 1% or higher. Maximum luminescence is observed in apatite with ∼2% Eu/Ca ratio (which equals to ∼0.2 apfu and corresponds to 3% Eu/Ca ratio in the starting solution). As an important and brand-new result, apatite with 2% Eu/Ca ratio can be considered as the most appropriate material for the producing biolabels for luminescent research in medicine and biology.

Nano-sized, quaternary titanium(IV) metal-organic frameworks with multidentate ligands.

PubMed

Baranwal, Balram Prasad; Singh, Alok Kumar

2010-12-01

Some mononuclear nano-sized, quaternary titanium(IV) complexes having the general formula [Ti(acac)(OOCR)2(SB)] (where Hacac=acetylacetone, R=C15H31 or C17H35, HSB=Schiff bases) have been synthesized using different multidentate ligands. These were characterized by elemental analyses, molecular weight determinations and spectral (FTIR, 1H NMR and powder XRD) studies. Conductance measurement indicated their non-conducting nature which may behave like insulators. Structural parameters like the values of limiting indices h, k, l, cell constants a, b, c, angles α, β, γ and particle size are calculated from powder XRD data for complex 1 which indicated nano-sized triclinic system in them. Bidentate chelating nature of acetylacetone, carboxylate and Schiff base anions in the complexes was established by their infrared spectra. Molecular weight determinations confirmed mononuclear nature of the complexes. On the basis of physico-chemical studies, coordination number 8 was assigned for titanium(IV) in the complexes. Transmission electron microscopy (TEM) and the selected area electron diffraction (SAED) studies indicated spherical particles with poor crystallinity. Copyright © 2010 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Guangci; Liu, Yunqi, E-mail: liuyq@upc.edu.cn; Liu, Di

Boehmite (AlOOH) with hierarchical flower-like structures was synthesized by the solvothermal reaction of AlCl{sub 3}.6H{sub 2}O in the presence of ethanol and toluene at 200 {sup o}C for 24 h. The product was characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that boehmite with flower-like nanostructures, which aggregated together by the weak hydrogen bonds, was formed through dissolution-deposition process of boehmite microcrystals and the toluene has a great effect on the morphology of product in the reaction system. Meanwhile, the {gamma}-Al{sub 2}O{sub 3} was alsomore » obtained by calcination of above product at 500 {sup o}C for 2 h, and the flower-like morphology kept no change. The surface area of {gamma}-Al{sub 2}O{sub 3} powder was determined to be 166.8 m{sup 2}/g by N{sub 2} adsorption measurement. The possible formation mechanism of flower-like boehmite nanostructures was proposed and discussed.« less

Extraction of cellulose from pistachio shell and physical and mechanical characterisation of cellulose-based nanocomposites

NASA Astrophysics Data System (ADS)

Movva, Mounika; Kommineni, Ravindra

2017-04-01

Cellulose is an important nanoentity that have been used for the preparation of composites. The present work focuses on the extraction of cellulose from pistachio shell and preparing a partially degradable nanocomposite with extracted cellulose. Physical and microstructural characteristics of nanocellulose extracted from pistachio shell powder (PSP) through various stages of chemical treatment are identified from scanning electron microscopy (SEM), Fourier transform infra-red spectroscopy (FTIR), x-ray powder diffraction (XRD), and thermogravimetric analysis (TGA). Later, characterized nanocellulose is reinforced in a polyester matrix to fabricate nanocellulose-based composites according to the ASTM standard. The resulting nanocellulose composite performance is evaluated in the mechanical perspective through tensile and flexural loading. SEM, FTIR, and XRD showed that the process for extraction is efficient in obtaining 95% crystalline cellulose. Cellulose also showed good thermal stability with a peak thermal degradation temperature of 361 °C. Such cellulose when reinforced in a matrix material showed a noteworthy rise in tensile and flexural strengths of 43 MPa and 127 MPa, at a definite weight percent of 5%.

Synthesis and structural properties of (Y, Sr)(Ti, Fe, Nb)O3-δ perovskite nanoparticles fabricated by modified polymer precursor method

NASA Astrophysics Data System (ADS)

Miruszewski, T.; Gdaniec, P.; Karczewski, J.; Bochentyn, B.; Szaniawska, K.; Kupracz, P.; Prześniak-Welenc, M.; Kusz, B.

2016-09-01

The yttrium, iron and niobium doped-SrTiO3 powders have been successfully fabricated by a modified low-temperature synthesis method from a polymer complex. The usage of strontium hydroxide precursor instead of conventional strontium nitrate or strontium carbonate provides to the possibility of significant decrease of annealing temperature. It allows to prepare a material with sphere-shape grains of nanometric size (15-70 nm). The results of thermal analysis indicate that the crystallization of precursor takes place at different stages. The product after heat treatment at 600 °C for 3 h in air was also characterized by X-Ray diffraction method (XRD) and Fourier transform - infrared spectroscopy (FT-IR). After the crystallization and the impurity removal process, a single-phase material was obtained in case of all analyzed samples. The morphology of obtained nano-powders was also studied by a scanning electron microscopy (SEM). It can be concluded, that this method allows obtaining a perovskite phase of a metal doped SrTiO3 with nanometric particles.

Influence of sodium fluoride on the synthesis of hydroxyapatite by gel method

NASA Astrophysics Data System (ADS)

Kanchana, P.; Sekar, C.

2010-03-01

Hydroxyapatite (HA) is a good candidate for bone substitutes due to its chemical and structural similarity to bone mineral. Hydroxyapatite has been grown by the gel method using sodium fluoride (NaF) as additive. The growth was carried out at room temperature under the physiological pH of 7.4. The addition of NaF has significantly reduced growth rate and the yield was much less when compared to pure system. The samples of pure and fluoride doped HA were sintered at 600, 900 and 1200 °C in ambient atmosphere. Scanning electron microscopy (SEM), powder X-ray diffraction (XRD), thermogravimetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR) were adopted to investigate the influence of NaF on the morphology, crystallinity, stability and phase purity of HA. EDAX and FTIR studies confirm that the fluoride is doped into the hydroxyapatite. Powder XRD and TGA results suggested that the incorporation of fluorine into the HA matrix improves the phase formation and crystallinity. SEM studies show that the microstructural morphology of HA changes from the fibers for pure to granular structure for the fluoride doped.

Synthesis and thermal evolution of structure in alkoxide-derived niobium pentoxide gels

NASA Technical Reports Server (NTRS)

Bansal, Narottam P.

1993-01-01

Niobium pentoxide gels in the form of transparent monoliths and powder have been synthesized from the controlled hydrolysis and polycondensation of niobium pentaethoxide under different experimental conditions using various mole ratios of Nb(OC2H5)5:H2O:C2H5OH:HCl. Alcohol acted as the mutual solvent and HCl as the deflocculating agent. In the absence of HCl, precipitation of colloidal particles was encountered on the addition of any water to the alkoxide. The gels were subjected to various thermal treatments and characterized by differential thermal analysis, thermogravimetric analysis, x-ray diffraction, and infrared spectroscopy. After drying at 400 C, the gels were amorphous to x-rays. The amorphous powder crystallized into the low-temperature orthorhombic form of Nb2O5 at approximately 500 C, which transformed irreversibly into the high-temperature monoclinic alpha-Nb2O5 between 900 to 1000 C. The kinetics of crystallization of the amorphous niobium pentoxide have been investigated by non-isothermal differential scanning calorimetry. The crystallization activation energy was determined to be 399 kJ/mol.

Interaction of hydrogen chloride and water with oxide surfaces. III - Titanium dioxide

NASA Technical Reports Server (NTRS)

Siriwardane, R. V.; Wightman, J. P.

1983-01-01

The adsorption of hydrogen chloride and water vapors on five TiO2 powders in both the anatase and rutile crystalline forms was studied as a function of temperature, pressure, and outgas conditions. The adsorbents were characterized utilizing X-ray powder diffraction, scanning electron microscopy, surface area analysis, indicator method, microelectrophoresis, XPS, and infrared spectroscopy. It was found that both outgas temperature and adsorption temperature influenced the adsorption of water vapor on TiO2, while water vapor adsorption on TiO2 was completely reversible. It is argued that the number of hydroxyl groups present on the surface determines the adsorption capacity of water on the different titanium dioxides. It was found that heats of immersion in water were affected significantly by outgas temperature. Hydrogen chloride adsorption isotherms at 30 C measured on TiO2 after outgassing at 100-400 C showed that a part of the total HCl adsorbed was irreversibly adsorbed. The highest HCl adsorption capacity per unit area was exhibited by anatase, while pure rutile exhibited the lowest adsorption capacity.

Spectroscopic investigation on the efficient organic nonlinear crystals of pure and diethanolamine added DAST.

PubMed

Karthikeyan, C; Haja Hameed, A S; Sagaya Agnes Nisha, J; Ravi, G

2013-11-01

4-N,N'-dimethylamino-N-methyl-4-stilbazolium toyslate (DAST) and diethanolamine (DEA) added DAST crystals are grown by slow cooling method. The corresponding powder samples are examined by characterization studies such as XRD, FT-IR, FT-Raman, UV-Vis-NIR and photoluminescence studies. From the powder X-ray diffraction, their lattice parameter values are found out. Since the vibrational spectra of the molecules are considerably contributed to their linear and nonlinear optical effects, Infrared and Raman spectroscopic studies are carried out for the samples. The UV-Vis-NIR absorption spectra of the samples are used to find the nature of transitions occurred in the samples. Using the density functional theory, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) analyses are done in order to explain the transition and density of states (DOS). The first order hyperpolarizability is calculated by HF and B3LYP/6-311 G(d,p) basis sets for the DAST molecule. From the photoluminescence (PL) spectral studies, the strong excitation emissions are observed. Copyright © 2013 Elsevier B.V. All rights reserved.

Study on optical properties of L-valine doped ADP crystal

NASA Astrophysics Data System (ADS)

Shaikh, R. N.; Anis, Mohd.; Shirsat, M. D.; Hussaini, S. S.

2015-02-01

Single crystal of L-valine doped ammonium dihydrogen phosphate has been grown by slow evaporation method at room temperature. The crystalline nature of the grown crystal was confirmed using powder X-ray diffraction technique. The different functional groups of the grown crystal were identified using Fourier transform infrared analysis. The UV-visible studies were employed to examine the high optical transparency and influential optical constants for tailoring materials suitability for optoelectronics applications. The cutoff wavelength of the title crystal was found to be 280 nm with wide optical band gap of 4.7 eV. The dielectric measurements were carried to determine the dielectric constant and dielectric loss at room temperature. The grown crystal has been characterized by thermogravimetric analysis. The second harmonic generation efficiency of the grown crystal was determined by the classical Kurtz powder technique and it is found to be 1.92 times that of potassium dihydrogen phosphate. The grown crystal was identified as third order nonlinear optical material employing Z-scan technique using He-Ne laser operating at 632.8 nm.

Near-infrared quantum cutting in Yb3+ ion doped strontium vanadate

NASA Astrophysics Data System (ADS)

Sawala, N. S.; Bajaj, N. S.; Omanwar, S. K.

2016-05-01

The materials Sr3-x(VO4)2:xYb were successfully synthesized by co-precipitation method varying the concentration of Yb3+ ions from 0 to 0.06 mol. It was characterize by powder X-ray powder diffraction (XRD) and surface morphology was studied by scanning electronic microscope (SEM). The photoluminescence (PL) properties were studied by spectrophotometers in near infra red (NIR) and ultra violet visible (UV-VIS) region. The Yb3+ ion doped tristrontium vanadate (Sr3(VO4)2) phosphors that can convert a photon of UV region (349 nm) into photons of NIR region (978, 996 and 1026 nm). Hence this phosphor could be used as a quantum cutting (QC) luminescent convertor in front of crystalline silicon solar cell (c-Si) panels to reduce thermalization loss due to spectral mismatch of the solar cells. The theoretical value of quantum efficiency (QE) was calculated from steady time decay measurement and the maximum efficiency approached up to 144.43%. The Sr(3-x) (VO4)2:xYb can be potentiality used for betterment of photovoltaic (PV) technology.

Synthesis and characterization of fluorapatite-titania (FAp-TiO 2) nanocomposite via mechanochemical process

NASA Astrophysics Data System (ADS)

Ebrahimi-Kahrizsangi, Reza; Nasiri-Tabrizi, Bahman; Chami, Akbar

2010-09-01

In this paper, synthesis of bionanocomposite of fluorapatite-titania (FAp-TiO 2) was studied by using one step mechanochemical process. Characterization of the products was accomplished by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. Based on XRD patterns and FT-IR spectroscopy, correlation between the structural features of the nanostructured FAp-TiO 2 and the process conditions was discussed. Variations in crystallite size, lattice strain, and volume fraction of grain boundary were investigated during milling and the following heat treatment. Crystallization of the nanocomposite occurred after thermal treatment at 650 °C. Morphological features of powders were influenced by the milling time. The resulting FAp-20 wt.%TiO 2 nanocomposite powder exhibited an average particle size of 15 nm after 20 h of milling. The results show that the one step mechanosynthesis technique is an effective route to prepare FAp-based nanocomposites with excellent morphological and structural features.

X-ray diffraction studies of shocked lunar analogs

NASA Technical Reports Server (NTRS)

Hanss, R. E.

1979-01-01

The X-ray diffraction experiments on shocked rock and mineral analogs of particular significance to lunar geology are described. Materials naturally shocked by meteorite impact, nuclear-shocked, or artificially shocked in a flat plate accelerator were utilized. Four areas were outlined for investigation: powder diffractometer studies of shocked single crystal silicate minerals (quartz, orthoclase, oligoclase, pyroxene), powder diffractometer studies of shocked polycrystalline monomineralic samples (dunite), Debye-Scherrer studies of single grains of shocked granodiorite, and powder diffractometer studies of shocked whole rock samples. Quantitative interpretation of peak shock pressures experienced by materials found in lunar or terrestrial impact structures is presented.

Solid state ¹³C-NMR, infrared, X-ray powder diffraction and differential thermal studies of the homologous series of some mono-valent metal (Li, Na, K, Ag) n-alkanoates: a comparative study.

PubMed

Nelson, Peter N; Ellis, Henry A; White, Nicole A S

2015-06-15

A comparative study of the molecular packing, lattice structures and phase behaviors of the homologous series of some mono-valent metal carboxylates (Li, Na, K and Ag) is carried out via solid state FT-infrared and (13)C-NMR spectroscopes, X-rays powder diffraction, density measurements, differential scanning calorimetry, polarizing light microscopy and variable temperature infrared spectroscopy. It is proposed that, for lithium, sodium and potassium carboxylates, metal-carboxyl coordination is via asymmetric chelating bidentate bonding with extensive intermolecular interactions to form tetrahedral metal centers, irrespective of chain length. However, for silver n-alkanoates, carboxyl moieties are bound to silver ions via syn-syn type bridging bidentate coordination to form dimeric units held together by extensive head group inter-molecular interactions. Furthermore, the fully extended hydrocarbon chains which are crystallized in the all-trans conformation are tilted at ca. 30°, 27°, 15° and 31° with respect to a normal to the metal plane, for lithium, sodium, silver and potassium carboxylates, respectively. All compounds are packed as lamellar bilayer structures, however, lithium compounds are crystallized in a triclinic crystal system whilst silver, sodium and potassium n-alkanoates are all monoclinic with possible P1 bravais lattice. Odd-even alternation observed in various physical features is associated with different inter-planar spacing between closely packed layers in the bilayer which are not in the same plane; a phenomenon controlled by lattice packing symmetry requirements. All compounds, except silver carboxylates, show partially reversibly first order pre-melting transitions; the number of which increases with increasing chain length. These transitions are associated, for the most part, with lamellar collapse followed by increased gauche-trans isomerism in the methylene group assembly, irrespective of chain length. It is proposed that the absence of mesomorphic transitions in their phase sequences is due to a lack of sufficient balance between attractive and repulsive electrostatic and van der Waals forces during phase change. The evidence presented in this study shows that phase behaviors of mono-valent metal carboxylates are controlled, mainly, by head group bonding. Copyright © 2015 Elsevier B.V. All rights reserved.

Diffraction experiments with infrared remote controls

NASA Astrophysics Data System (ADS)

Kuhn, Jochen; Vogt, Patrik

2012-02-01

In this paper we describe an experiment in which radiation emitted by an infrared remote control is passed through a diffraction grating. An image of the diffraction pattern is captured using a cell phone camera and then used to determine the wavelength of the radiation.

On the possibility of using polycrystalline material in the development of structure-based generic assays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allaire, Marc, E-mail: allaire@bnl.gov; Moiseeva, Natalia; Botez, Cristian E.

The correlation coefficients calculated between raw powder diffraction profiles can be used to identify ligand-bound/unbound states of lysozyme. The discovery of ligands that bind specifically to a targeted protein benefits from the development of generic assays for high-throughput screening of a library of chemicals. Protein powder diffraction (PPD) has been proposed as a potential method for use as a structure-based assay for high-throughput screening applications. Building on this effort, powder samples of bound/unbound states of soluble hen-egg white lysozyme precipitated with sodium chloride were compared. The correlation coefficients calculated between the raw diffraction profiles were consistent with the known bindingmore » properties of the ligands and suggested that the PPD approach can be used even prior to a full description using stereochemically restrained Rietveld refinement.« less

Addressing the amorphous content issue in quantitative phase analysis: the certification of NIST standard reference material 676a.

PubMed

Cline, James P; Von Dreele, Robert B; Winburn, Ryan; Stephens, Peter W; Filliben, James J

2011-07-01

A non-diffracting surface layer exists at any boundary of a crystal and can comprise a mass fraction of several percent in a finely divided solid. This has led to the long-standing issue of amorphous content in standards for quantitative phase analysis (QPA). NIST standard reference material (SRM) 676a is a corundum (α-Al(2)O(3)) powder, certified with respect to phase purity for use as an internal standard in powder diffraction QPA. The amorphous content of SRM 676a is determined by comparing diffraction data from mixtures with samples of silicon powders that were engineered to vary their specific surface area. Under the (supported) assumption that the thickness of an amorphous surface layer on Si was invariant, this provided a method to control the crystalline/amorphous ratio of the silicon components of 50/50 weight mixtures of SRM 676a with silicon. Powder diffraction experiments utilizing neutron time-of-flight and 25 keV and 67 keV X-ray energies quantified the crystalline phase fractions from a series of specimens. Results from Rietveld analyses, which included a model for extinction effects in the silicon, of these data were extrapolated to the limit of zero amorphous content of the Si powder. The certified phase purity of SRM 676a is 99.02% ± 1.11% (95% confidence interval). This novel certification method permits quantification of amorphous content for any sample of interest, by spiking with SRM 676a.

Cooperative upconversion luminescence in Tb{sup 3+}:Yb{sup 3+} co-doped Y{sub 2}SiO{sub 5} powders prepared by combustion synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rakov, Nikifor, E-mail: nikifor.gomez@univasf.edu.br; Vieira, Simone A.; Guimarães, Renato B.

2014-03-15

Frequency upconversion (UC) luminescence via cooperative energy transfer (CET) process between pairs of Yb{sup 3+} and Tb{sup 3+} ions was investigated in Tb{sup 3+}:Yb{sup 3+}:Y{sub 2}SiO{sub 5} crystalline ceramic powders prepared by combustion synthesis. Surface morphology and structure of the powders were investigated by scanning electronic microscopy and X-ray powder diffraction. Photoluminescence experiments were performed in Tb{sup 3+}-singly doped samples using ultraviolet light (λ=255 nm) and in Tb{sup 3+}:Yb{sup 3+} co-doped samples using a near-infrared (NIR) diode laser (λ=975 nm). Upon excitation with the NIR diode laser, UC luminescence with an intense emission band centered at ∼549 nm, corresponding tomore » the 4f intraband {sup 5}D{sub 4}→{sup 7}F{sub 5} transition of Tb{sup 3+}, along with less intense emission bands at ∼490, ∼590 and ∼620 nm, corresponding to other {sup 5}D{sub 4}→{sup 7}F{sub J} transitions, was detected. The CET rate was estimated by analyzing the dynamics of UC luminescence with rate equations model of the electronic populations. -- Graphical Abstract: Left: Cooperative upconversion luminescence spectra of three powder samples prepared by combustion synthesis. Right: The SEM image of the powder showing that it consists of agglomerated flake-like shaped particles of various sizes. Full scale bar is 20 μm. Highlights: • Yttrium orthosilicate (Y{sub 2}SiO{sub 5}) powders were prepared by combustion synthesis. • Cooperative upconversion is observed for the first time in Tb{sup 3+}–Yb{sup 3+} doped Y{sub 2}SiO{sub 5}. • Energy transfer and back-transfer rates between Tb{sup 3+} and Yb{sup 3+} pairs were estimated.« less

Effect of the Chemical State of the Surface on the Relaxation of the Surface Shell Atoms in SiC and GaN Nanocrystals

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Weber, H. P.; Janik, J. F.; Palosz, W.; Curreri, Peter A. (Technical Monitor)

2002-01-01

The effect of the chemical state of the surface of nanoparticles on the relaxation in the near-surface layer was examined using the concept of the apparent lattice parameter (alp) determined for different diffraction vectors Q. The apparent lattice parameter is a lattice parameter determined either from an individual Bragg reflection, or from a selected region of the diffraction pattern. At low diffraction vectors the Bragg peak positions are affected mainly by the structure of the near-surface layer, while at high Q-values only the interior of the nano-grain contributes to the diffraction pattern. Following the measurements on raw (as prepared) powders we investigated powders cleaned by annealing at 400C under vacuum, and the same powders wetted with water. Theoretical alp-Q plots showed that the structure of the surface layer depends on the sample treatment. Semi-quantitative analysis based on the comparison of the experimental and theoretical alp-Q plots was performed. Theoretical alp-Q relations were obtained from the diffraction patterns calculated for models of nanocrystals with a strained surface layer using the Debye functions.

Characterization of composite materials based on cement-ceramic powder blended binder

NASA Astrophysics Data System (ADS)

Kulovaná, Tereza; Pavlík, Zbyšek

2016-06-01

Characterization of newly developed composite mortars with incorporated ceramic powder coming from precise brick cutting as partial Portland cement replacement up to 40 mass% is presented in the paper. Fine ceramic powder belongs to the pozzolanic materials. Utilization of pozzolanic materials is accompanied by lower request on energy needed for Portland clinker production which generally results in lower production costs of blended binder and lower CO2 emission. In this paper, the ceramic powder is used in cement based mortar composition in amount of 8, 16, 24, 32, and 40 mass% of cement. Chemical composition of ceramic powder is analyzed by X-Ray Fluorescence and X-Ray Diffraction. The particle size distribution of ceramics is accessed on laser diffraction principle. For 28 days cured mortar samples, basic physical and mechanical properties are experimentally determined. The obtained results demonstrate that ceramic powder has potential to replace a part of Portland cement in composition of cement based composites and to reduce negative environmental impact of their production.

Phase analysis of ZrO2-SiO2 systems synthesized through Ball milling mechanical activations

NASA Astrophysics Data System (ADS)

Nurlaila, Rizka; Musyarofah, Muwwaqor, Nibras Fuadi; Triwikantoro, Kuswoyo, Anton; Pratapa, Suminar

2017-01-01

Zircon powders have been produced from raw materials of amorphous zirconia and amorphous silica powders obtained from natural zircon sand of Kalimantan Tengah, Indonesia. Synthesis process was started with the extraction of zircon powder to produce sodium silicate solution and pure zircon powder. The amorphous zirconia and silica powders were prepared by alkali fusion and co-precipitation techniques. The powders were mixed using a planetary ball mill, followed by a calcination of various holding time of 3, 10, and 15 h. Phase characterization was done using X-Ray Diffraction (XRD) technique and analysis of the diffraction data was carried out using Rietica and MAUD software. The identified phases after the calcination were zircon, tetragonal zirconia, and cristobalite. The highest zircon content was obtained in the sample calcinated for15 hours - reaching 99.66 %wt. Crystallite size analysis revealed that the samples calcinated for 3, 10, and 15 h exhibited zircon crystal size of 176 (1) nm, 191 (1) nm and 233 (1) nm respectively.

Characterization of composite materials based on cement-ceramic powder blended binder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulovaná, Tereza; Pavlík, Zbyšek

Characterization of newly developed composite mortars with incorporated ceramic powder coming from precise brick cutting as partial Portland cement replacement up to 40 mass% is presented in the paper. Fine ceramic powder belongs to the pozzolanic materials. Utilization of pozzolanic materials is accompanied by lower request on energy needed for Portland clinker production which generally results in lower production costs of blended binder and lower CO{sub 2} emission. In this paper, the ceramic powder is used in cement based mortar composition in amount of 8, 16, 24, 32, and 40 mass% of cement. Chemical composition of ceramic powder is analyzedmore » by X-Ray Fluorescence and X-Ray Diffraction. The particle size distribution of ceramics is accessed on laser diffraction principle. For 28 days cured mortar samples, basic physical and mechanical properties are experimentally determined. The obtained results demonstrate that ceramic powder has potential to replace a part of Portland cement in composition of cement based composites and to reduce negative environmental impact of their production.« less

Performance Characteristics of Waste Glass Powder Substituting Portland Cement in Mortar Mixtures

NASA Astrophysics Data System (ADS)

Kara, P.; Csetényi, L. J.; Borosnyói, A.

2016-04-01

In the present work, soda-lime glass cullet (flint, amber, green) and special glass cullet (soda-alkaline earth-silicate glass coming from low pressure mercury-discharge lamp cullet and incandescent light bulb borosilicate glass waste cullet) were ground into fine powders in a laboratory planetary ball mill for 30 minutes. CEM I 42.5N Portland cement was applied in mortar mixtures, substituted with waste glass powder at levels of 20% and 30%. Characterisation and testing of waste glass powders included fineness by laser diffraction particle size analysis, specific surface area by nitrogen adsorption technique, particle density by pycnometry and chemical analysis by X-ray fluorescence spectrophotometry. Compressive strength, early age shrinkage cracking and drying shrinkage tests, heat of hydration of mortars, temperature of hydration, X-ray diffraction analysis and volume stability tests were performed to observe the influence of waste glass powder substitution for Portland cement on physical and engineering properties of mortar mixtures.

Polymorphism of Alprazolam (Xanax): a review of its crystalline phases and identification, crystallographic characterization, and crystal structure of a new polymorph (form III).

PubMed

de Armas, Héctor Novoa; Peeters, Oswald M; Van den Mooter, Guy; Blaton, Norbert

2007-05-01

A new polymorphic form of Alprazolam (Xanax), 8-chloro-1-methyl-6-phenyl-4H-[1,2,4]triazolo-[4,3-alpha][1,4]benzodiazepine, C(17)H(13)ClN(4), has been investigated by means of X-ray powder diffraction (XRPD), single crystal X-ray diffraction, and differential scanning calorimetry (DSC). This polymorphic form (form III) was obtained during DSC experiments after the exothermic recrystallization of the melt of form I. The crystal unit cell dimensions for form III were determined from diffractometer methods. The monoclinic unit cell found for this polymorph using XRPD after indexing the powder diffractogram was confirmed by the cell parameters obtained from single crystal X-ray diffractometry on a crystal isolated from the DSC pans. The single crystal unit cell parameters are: a = 28.929(9), b = 13.844(8), c = 7.361(3) angstroms, beta = 92.82(3) degrees , V = 2944(2) angstroms(3), Z = 8, space group P2(1) (No.4), Dx = 1.393 Mg/m(3). The structure obtained from single crystal X-ray diffraction was used as initial model for Rietveld refinement on the powder diffraction data of form III. The temperature phase transformations of alprazolam were also studied using high temperature XRPD. A review of the different phases available in the Powder Diffraction File (PDF) database for this drug is described bringing some clarification and corrections. (c) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.

Influence of short chain organic acids and bases on the wetting properties and surface energy of submicrometer ceramic powders.

PubMed

Neirinck, Bram; Soccol, Dimitri; Fransaer, Jan; Van der Biest, Omer; Vleugels, Jef

2010-08-15

The effect of short chained organic acids and bases on the surface energy and wetting properties of submicrometer alumina powder was assessed. The surface chemistry of treated powders was determined by means of Diffuse Reflectance Infrared Fourier Transform spectroscopy and compared to untreated powder. The wetting of powders was measured using a modified Washburn method, based on the use of precompacted powder samples. The geometric factor needed to calculate the contact angle was derived from measurements of the porous properties of the powder compacts. Contact angle measurements with several probe liquids before and after modification allowed a theoretical estimation of the surface energy based on the surface tension component theory. Trends in the surface energy components were linked to observations in infrared spectra. The results showed that the hydrophobic character of the precompacted powder depends on both the chain length and polar group of the modifying agent. Copyright 2010 Elsevier Inc. All rights reserved.

Detection of melamine in milk powder using MCT-based short-wave infrared hyperspectral imaging system.

PubMed

Lee, Hoonsoo; Kim, Moon S; Lohumi, Santosh; Cho, Byoung-Kwan

2018-06-05

Extensive research has been conducted on non-destructive and rapid detection of melamine in powdered foods in the last decade. While Raman and near-infrared hyperspectral imaging techniques have been successful in terms of non-destructive and rapid measurement, they have limitations with respect to measurement time and detection capability, respectively. Therefore, the objective of this study was to develop a mercury cadmium telluride (MCT)-based short-wave infrared (SWIR) hyperspectral imaging system and algorithm to detect melamine quantitatively in milk powder. The SWIR hyperspectral imaging system consisted of a custom-designed illumination system, a SWIR hyperspectral camera, a data acquisition module and a sample transfer table. SWIR hyperspectral images were obtained for melamine-milk samples with different melamine concentrations, pure melamine and pure milk powder. Analysis of variance and the partial least squares regression method over the 1000-2500 nm wavelength region were used to develop an optimal model for detection. The results showed that a melamine concentration as low as 50 ppm in melamine-milk powder samples could be detected. Thus, the MCT-based SWIR hyperspectral imaging system has the potential for quantitative and qualitative detection of adulterants in powder samples.

Mg(1 + x)Ir(1 - x) (x = 0, 0.037 and 0.054), a binary intermetallic compound with a new orthorhombic structure type determined from powder and single-crystal X-ray diffraction.

PubMed

Cerný, Radovan; Renaudin, Guillaume; Favre-Nicolin, Vincent; Hlukhyy, Viktor; Pöttgen, Rainer

2004-06-01

The new binary compound Mg(1 + x)Ir(1 - x) (x = 0-0.054) was prepared by melting the elements in the Mg:Ir ratio 2:3 in a sealed tantalum tube under an argon atmosphere in an induction furnace (single crystals) or by annealing cold-pressed pellets of the starting composition Mg:Ir 1:1 in an autoclave under an argon atmosphere (powder sample). The structure was independently solved from high-resolution synchrotron powder and single-crystal X-ray data: Pearson symbol oC304, space group Cmca, lattice parameters from synchrotron powder data a = 18.46948 (6), b = 16.17450 (5), c = 16.82131 (5) A. Mg(1 + x)Ir(1 - x) is a topologically close-packed phase, containing 13 Ir and 12 Mg atoms in the asymmetric unit, and has a narrow homogeneity range. Nearly all the atoms have Frank-Kasper-related coordination polyhedra, with the exception of two Ir atoms, and this compound contains the shortest Ir-Ir distances ever observed. The solution of a rather complex crystal structure from powder diffraction, which was fully confirmed by the single-crystal method, shows the power of powder diffraction in combination with the high-resolution data and the global optimization method.

Roller compaction of different pseudopolymorphic forms of theophylline: Effect on compressibility and tablet properties.

PubMed

Hadzović, Ervina; Betz, Gabriele; Hadzidedić, Seherzada; El-Arini, Silvia Kocova; Leuenberger, Hans

2010-08-30

The effect of roller compaction on disintegration time, dissolution rate and compressibility of tablets prepared from theophylline anhydrate powder, theophylline anhydrate fine powder and theophylline monohydrate was studied. In addition, the influence of adding microcrystalline cellulose, a commonly used excipient, in mixtures with these materials was investigated. Theophylline anhydrate powder was used as a model drug to investigate the influence of different compaction pressures on the tablet properties. Tablets with same porosity were prepared by direct compaction and by roller compaction/re-compaction. Compressibility was characterized by Heckel and modified Heckel equations. Due to the property of polymorphic materials to change their form during milling and compression, X-ray diffraction analysis of theophylline anhydrate powder, theophylline anhydrate fine powder and theophylline monohydrate powders and granules was carried out. After roller compaction the disintegration time and the dissolution rate of the tablets were significantly improved. Compressibility of theophylline anhydrate powder and theophylline anhydrate fine powder was decreased, while theophylline monohydrate showed higher compressibility after roller compaction. Microcrystalline cellulose affected compressibility of theophylline anhydrate powder, theophylline anhydrate fine powder and theophylline monohydrate whereby the binary mixtures showed higher compressibility than the individual materials. X-ray diffraction analyses confirmed that there were no polymorphic/pseudopolymorphic changes after roller compaction. Copyright 2010 Elsevier B.V. All rights reserved.

Three pharmaceuticals cocrystals of adefovir: Syntheses, structures and dissolution study

NASA Astrophysics Data System (ADS)

Zhang, Xiaoming; Sun, Fuxing; Zhang, Tingting; Jia, Jiangtao; Su, Hongmin; Wang, Chenhui; Zhu, Guangshan

2015-11-01

We report here three novel cocrystals, which are composed of adefovir as the API (Active Pharmaceutical Ingredient) with p-aminobenzoic acid (1, 2C8H12N5O4P·C7H6NO2·3H2O), 3,5-dihydroxybenzoic acid (2, C8H12N5O4P·C7H6O4·H2O) and 2,6-pyridinedicarboxlic acid (3, C8H12N5O4P·C7H5NO4) as CCFs (cocrystal formers) respectively by crystal engineering strategy. Their structures were characterized by single crystal X-ray diffraction, powder X-ray diffraction (PXRD) analysis, thermogravimetric analyses (TGA), elemental analysis (EA) and infrared spectral analysis (IR). The analysis of single crystal X-ray diffraction demonstrate that cocrystal 1 and 2 form a strong hydrogen-bonded assembly through the phosphoric acids of API with water in the lattice and carboxylic acids of CCF respectively. Cocrystal 3 is formed in which the phosphoric acid groups of API are also held by the carboxylic acid groups of CCF. The PXRD results indicate their high purity of as-synthesized samples. The TGA, EA, IR and dissolution study of API and the cocrystals were also measured and discussed.

Synthesis, characterization and dissolution of three pharmaceutical cocrystals based on deferiprone

NASA Astrophysics Data System (ADS)

Zhang, Xiaoming; Tian, Yuyang; Jia, Jiangtao; Zhang, Tingting; Zhu, Guangshan

2016-03-01

In this paper we present three new cocrystals based on deferiprone which is the first oral medicine as iron chelator. Solitary deferiprone possesses some known problems due to its good solubility and frequent dosing side effects. For these three novel co crystals, deferiprone is the active pharmaceutical ingredient (API), p-hydroxybenzoic acid (1, C7H9NO2·C7H6O3), 2, 5-dihydroxybenzoic acid (2, C7H9NO2·C7H6O4) and maleic acid (3, C7H9NO2·C4H4O4) are used as cocrystal formers (CCFs), respectively. Their structures were characterized by single crystal X-ray diffraction, powder X-ray diffraction (PXRD) analysis, thermogravimetric analyses (TGA), differential thermal analysis (DTA), elemental analysis (EA) and infrared spectral analysis (IR). Single crystal X-ray diffraction demonstrates that all three cocrystals (1-3) possess strong hydrogen-bondings assembled through hydroxyl of API and carboxylic acids of CCFs. The PXRD results indicate their high purity of as-synthesized samples. TGA, DTA, EA, IR and dissolution study of API and cocrystals were also measured and discussed, respectively. The results suggest that the cocrystals exhibit low dissolution rates comparing with solitary deferiprone, which is very advantageous for the oral medicine with frequent dosing side effects.

Synthesis, growth, structural characterization, Hirshfeld analysis and nonlinear optical studies of a methyl substituted chalcone

NASA Astrophysics Data System (ADS)

Prabhu, Shobha R.; Jayarama, A.; Chandrasekharan, K.; Upadhyaya, V.; Ng, Seik Weng

2017-05-01

A new chalcone compound (2E)-3-(3-methylphenyl)-1-(4-nitrophenyl)prop-2-en-1-one (3MPNP) with molecular formula C16H13NO3 has been synthesized and crystallized by slow solvent evaporation technique. The Fourier transform infrared, Fourier transform Raman and nuclear magnetic resonance techniques were used for structural characterization. UV-visible absorption studies were carried out to study the transparency of the crystal in the visible region. Differential scanning calorimetry study shows thermal stability of crystals up to temperature 122 °C. Single crystal X-ray diffraction and powder X-ray diffraction techniques were used to study crystal structure and cell parameters. The Hirshfeld surface and 2-D fingerprint analysis were performed to study the nature of interactions and their quantitative contributions towards the crystal packing. The third order non-linear optical properties have been studied using single beam Z-scan technique and the results show that the material is a potential candidate for optical device applications such as optical limiters and optical switches.

Hydrothermal synthesis, crystal structures, and enantioselective adsorption property of bis(L-histidinato)nickel(II) monohydrate

NASA Astrophysics Data System (ADS)

Ramos, Christian Paul L.; Conato, Marlon T.

2018-05-01

Despite the numerous researches in metal-organic frameworks (MOFs), there are only few reports on biologically important amino acids, histidine in particular, on its use as bridging ligand in the construction of open-framework architectures. In this work, hydrothermal synthesis was used to prepare a compound based on Ni2+ and histidine. The coordination assembly of imidazole side chain of histidine with divalent nickel ions in aqueous condition yielded purple prismatic solids. Single crystal X-ray diffraction (XRD) analysis of the product revealed structure for Ni(C6H8N3O2)2 • H2O that has a monoclinic (C2) structure with lattice parameters, a = 29.41, b = 8.27, c = 6.31 Å, β = 90.01 ˚. Circular dichroism - optical rotatory dispersion (CD-ORD), Powder X-ray diffraction (PXRD) and Fourier transform - infrared spectroscopy (FT-IR) analyses are conducted to further characterize the crystals. Enantioselective adsorption analysis using racemic mixture of 2-butanol confirmed bis(L-histidinato)nickel(II) monohydrate MOF crystal's enantioselective property preferentially favoring the adsorption of (S)-2-butanol isomer.

Screening and structural elucidation of the zwitterionic cocrystal o-picolinic acid with p-nitro aniline

NASA Astrophysics Data System (ADS)

Mekala, R.; Jagdish, P.; Mathammal, R.; Sangeetha, K.

2017-04-01

The cocrystal was screened by solvent drop grinding method and the crystals were grown by slow evaporation method at ambient conditions. The cocrystal formation of o-picolinic acid with p-nitro aniline was initially analysed by powder X-ray diffraction. Further the structural properties of the grown crystal were confirmed by the single X-ray diffraction which indicates that the cocrystal were connected by the strong N+sbnd H-⋯O hydrogen bond interaction. The cell parameters of the grown crystal were a = 14.2144(5) Å, b = 5.7558(2) Å, c = 16.0539(6) Å. The functional groups were identified using Fourier transform infrared and Raman spectral analysis. The excitation and emission state of the sample was analysed by the UV-Visible and Fluorescence studies. The red emission was observed from the Fluorescence studies. NMR studies revealed the chemical shift of the cocrystal. Thermal stability and its melting behaviour were studied by TGA and DSC analytical techniques. Electrical behaviour was studied using the dielectric studies. The intermolecular charge transfer within the molecule were analysed using HOMO- LUMO plots.

A novel structure of gel grown strontium cyanurate crystal and its structural, optical, electrical characterization

NASA Astrophysics Data System (ADS)

Divya, R.; Nair, Lekshmi P.; Bijini, B. R.; Nair, C. M. K.; Gopakumar, N.; Babu, K. Rajendra

2017-12-01

Strontium cyanurate crystals with novel structure and unique optical property like mechanoluminescence have been grown by conventional gel method. Transparent crystals were obtained. The single crystal X-ray diffraction analysis reveals the exquisite structure of the grown crystal. The crystal is centrosymmetric and has a three dimensional polymeric structure. The powder X ray diffraction analysis confirms its crystalline nature. The functional groups present in the crystal were identified by Fourier transform infrared spectroscopy. Elemental analysis confirmed the composition of the complex. A study of thermal properties was done by thermo gravimetric analysis and differential thermal analysis. The optical properties like band gap, refractive index and extinction coefficient were evaluated from the UV visible spectral analysis. The etching study was done to reveal the dislocations in the crystal which in turn explains mechanoluminescence emission. The mechanoluminescence property exhibited by the crystal makes it suitable for stress sensing applications. Besides being a centrosymmetric crystal, it also exhibits NLO behavior. Dielectric properties were studied and theoretical calculations of Fermi energy, valence electron plasma energy, penn gap and polarisability have been done.

Structural and magnetic properties of Ni0.8M0.2Fe2O4 (M = Cu, Co) nano-crystalline ferrites

NASA Astrophysics Data System (ADS)

Vijaya Babu, K.; Satyanarayana, G.; Sailaja, B.; Santosh Kumar, G. V.; Jalaiah, K.; Ravi, M.

2018-06-01

Nano-crystalline nickel ferrites are interesting materials due to their large physical and magnetic properties. In the present work, two kinds of spinel ferrites Ni0.8M0.2Fe2O4 (M = Cu, Co) are synthesized by using sol-gel auto-combustion method and the results are compared with NiFe2O4. The structural properties of synthesized ferrites are determined by using X-ray powder diffraction; scanning electron microscope and Fourier transform infrared spectroscopy. The cation distribution obtained from X-ray diffraction show that cobalt/copper occupies only tetrahedral site in spinel lattice. The lattice constant increases with the substitution of cobalt/copper. The structural parameters like bond lengths, tetrahedral and octahedral edges have been varied with the substitution. The microstructural study is carried out by using SEM technique and the average grain size is increased with nickel ferrite. The initial permeability (μi) is improving with the substitution. The observed g-value from ESR is approximately equal to standard value.

Synthesis and characterization of nano TiO2-SiO2: PVA composite - a novel route

NASA Astrophysics Data System (ADS)

Venckatesh, Rajendran; Balachandaran, Kartha; Sivaraj, Rajeshwari

2012-07-01

A novel, simple, less time consuming and cost-effective sol-gel method has been developed to synthesize nano titania-silica with polyvinyl alcohol (PVA) composite relatively at low temperature in acidic pH. Titania sol is prepared by hydrolysis of titanium tetrachloride and was mixed with silicic acid and tetrahydrofuran mixture. The reaction was carried out under vigorous stirring for 6 h and dried at room temperature with the addition of PVA solution. The resulting powders were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared (FT-IR), UV-visible spectroscopy and thermal techniques. The grain size of the particles was calculated by X-ray diffraction; surface morphology and chemical composition were determined from scanning electron microscopy-energy dispersive spectroscopy; metal oxide stretching was confirmed from FT-IR spectroscopy; bandgap was calculated using UV-visible spectroscopy, and thermal stability of the prepared composite was determined by thermogravimetric/differential thermal analysis. Since TiO2 got agglomerated on the surface of SiO2, effective absorptive sites increase which in turn increase the photocatalytic efficiency of the resulting composite.

Influence of spray drying and dispersing agent on surface and dissolution properties of griseofulvin micro and nanocrystals.

PubMed

Shah, Dhaval A; Patel, Manan; Murdande, Sharad B; Dave, Rutesh H

2016-11-01

The purpose for the current research is to compare and evaluate physiochemical properties of spray-dried (SD) microcrystals (MCs), nanocrystals (NCs), and nanocrystals with a dispersion agent (NCm) from a poorly soluble compound. The characterization was carried out by performing size and surface analysis, interfacial tension (at particle moisture interface), and in-vitro drug dissolution rate experiments. Nanosuspensions were prepared by media milling and were spray-dried. The SD powders that were obtained were characterized morphologically using scanning electron microscopy (SEM), polarized light microscopy (PLM), and Flowchem. Solid-state characterization was performed using X-ray powder diffraction (XRPD), Fourier transfer infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC) for the identification of the crystalline nature of all the SD powders. The powders were characterized for their redispersion tendency in the water and in pH 1.2. Significant differences in redispersion were noted for both the NCs in both dissolution media. The interfacial tension for particle moisture interface was determined by applying the BET (Braunauer-Emmett-Teller) equation to the vapor sorption data. No significant reduction in the interfacial tension was observed between MCs and NCs; however, a significant reduction in the interfacial tension was observed for NCm at both 25 °C and 35 °C temperatures. The difference in interfacial tension and redispersion behavior can be attributed to a difference in the wetting tendency for all the SD powders. The dissolution studies were carried out under sink and under non-sink conditions. The non-sink dissolution approach was found suitable for quantification of the dissolution rate enhancement, and also for providing the rank order to the SD formulations.

Low temperature synthesis of nano alpha-alumina powder by two-step hydrolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Ting; Guo, Xiaode, E-mail: guoxiaodenj@sina.com; Zhang, Xiang

Highlights: • The nano α-Al{sub 2}O{sub 3} with good dispersion was prepared by two-step hydrolysis. • α-Al{sub 2}O{sub 3} powders were added as seed particles in the hydrolysis. • This article indicated that the glucose could impel the γ-Al{sub 2}O{sub 3} transformed to α-Al{sub 2}O{sub 3} directly. • This article indicated that the addictive of α-Al{sub 2}O{sub 3} seed could improve the phase transformation rate of γ-Al{sub 2}O{sub 3} to α-Al{sub 2}O{sub 3}. • In this article, the pure α-Al{sub 2}O{sub 3} could be obtained by calcining at 1000 °C for 1.5 h. - Abstract: The ultral fine alpha-alumina powdermore » has been successfully synthesized via two-step hydrolysis of aluminum isopropoxide. Glucose and polyvinyl pyrrolidone were used as surfactants during the appropriate processing step. The alpha-alumina powder was used as seed particles. Several synthesis parameters, such as the amount of seeds, surfactants, and calcination temperature, were studied by X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), Thermogravimetry-differential scanning calorimetry (TG-DSC), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The experimental results showed that glucose greatly lower the phase transformation temperature of alpha-alumina by impelling the gamma-alumina transformed to alpha-alumina directly, and the seed could improve the phase transformation rate of alpha-alumina, the polyvinylpyrrolidone have an effect on preventing excessive grain growth and agglomeration of alpha-alumina powder. Comparatively well dispersed alpha-alumina powder with particle size less than 50 nm can be synthesized through this method after calcinations at 1000 °C for 2 h.« less

Crystal structure of hydrocortisone acetate, C23H32O6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaduk, James A.; Gindhart, Amy M.; Blanton, Thomas N.

The crystal structure of hydrocortisone acetate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Hydrocortisone acetate crystallizes in space groupP2 1(#4) witha= 8.85173(3) Å,b= 13.53859(3) Å,c= 8.86980(4) Å,β= 101.5438(3)°,V= 1041.455(6) Å 3, andZ= 2. Both hydroxyl groups form hydrogen bonds to the ketone oxygen atom on the steroid ring system, resulting in a three-dimensional hydrogen bond network. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.

Physiochemical Characterization and Release Rate Studies of SolidDispersions of Ketoconazole with Pluronic F127 and PVP K-30

PubMed Central

Kumar, Pankaj; Mohan, Chander; KanamSrinivasan Uma Shankar, Mara; Gulati, Monica

2011-01-01

In the present study solid dispersions of the antifungal drug Ketoconazole were prepared with Pluronic F-127 and PVP K-30 with an intention to improve its dissolution properties. Investigations of the properties of the dispersions were performed using release studies, Differential scanning calorimetery (DSC), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR). The results obtained showed that the rate of dissolution of Ketoconazole was considerably improved when formulated in solid dispersions with PVP K-30 and Pluronic F-127 as compared with pure drug and physical mixtures. The results from DSC and XRD studies showed the transition of crystalline nature of drug to amorphous form, while FTIR studies demonstrated the absence of drug-carriers interaction. PMID:24250403

Application of Solid-State NMR to Reveal Structural Differences in Cefazolin Sodium Pentahydrate from Different Manufacturing Processes

NASA Astrophysics Data System (ADS)

Tian, Ye; Wang, Wei D.; Zou, Wen-Bo; Qian, Jian-Qin; Hu, Chang-Qin

2018-04-01

The solid form of an active pharmaceutical ingredient is important when developing a new chemical entity. A solid understanding of the crystal structure and morphology that affect the mechanical and physical characteristics of pharmaceutical powders determines the manufacturing process. Solid-state NMR, thermogravimetric analysis, X-ray diffraction, and Fourier-transform infrared spectroscopy were combined with theoretical calculation to investigate different crystal packings of α-cefazolin sodium from three different vendors and conformational polymorphism was identified to exist in the α-cefazolin sodium. Marginal differences observed among CEZ-Na pentahydrate 1, 2, and 3 were speculated as the proportion of conformation 2. Understanding the differences in the polymorphic structure of α-cefazolin sodium may help with making modifications to incorporate new knowledge with a product’s development.

Growth and characterization of organic material 4-dimethylaminobenzaldehyde single crystal.

PubMed

Jebin, R P; Suthan, T; Rajesh, N P; Vinitha, G; Madhusoodhanan, U

2015-01-25

The organic material 4-dimethylaminobenzaldehyde single crystals were grown by slow evaporation technique. The grown crystal was confirmed by the single crystal and powder X-ray diffraction analyses. The functional groups of the crystal have been identified from the Fourier Transform Infrared (FTIR) and FT-Raman studies. The optical property of the grown crystal was analyzed by UV-Vis-NIR and photoluminescence (PL) spectral measurements. The thermal behavior of the grown crystal was analyzed by thermogravimetric (TG) and differential thermal analyses (DTA). Dielectric measurements were carried out with different frequencies by using parallel plate capacitor method. The third order nonlinear optical properties of 4-dimethylaminobenzaldehyde was measured by the Z-scan technique using 532 nm diode pumped continuous wave (CW) Nd:YAG laser. Copyright © 2014 Elsevier B.V. All rights reserved.

Hydrothermally synthesized flower like MoS2 microsphere: A highly efficient adsorbent for methylene blue dye removal

NASA Astrophysics Data System (ADS)

Panda, Jnanranjan; Tudu, Bharati

2018-05-01

Herein, a flower like MoS2 (M1) microsphere assembled by layered porous nanosheet was successfully prepared by facile hydrothermal synthesis procedure. The structural, chemical and morphological characterizations for the as synthesized sample (M1) were carried out by powder x-ray diffraction (PXRD), Fourier-transform infrared (FTIR) and Field Emission Scanning Electron microscope (FESEM) respectively and spectroscopic characterization was performed by UV-Vis absorption and photoluminescence emission spectroscopy. The photocatalytic activity of the product was evaluated through photocatalytic degradation of Methylene Blue under visible light irradiation. The results indicate that layered MoS2structures possess significant adsorption ability, which may be useful for further research and practical applications of the layered MoS2 adsorbent in wastewater treatment.

NASA Astrophysics Data System (ADS)

Wang, Mao-Hua; Zhang, Bo; Zhou, Fu

2014-07-01

Silica was homogeneously coated on the surface of CaCu3Ti4O12 (CCTO) particles via the sol-gel method. The obtained powders were characterized by x-ray diffraction analysis, Fourier-transform infrared spectroscopy, transmission electron microscopy (TEM), energy-dispersive spectroscopy, scanning electron microscopy, and zeta potential analysis. The results demonstrate that there were silica layers on the surface of the CCTO particles. Physical and dielectric properties of silica-coated CCTO were also studied. TEM imaging showed that the thickness of the silica layer on the CCTO particles was about 20 nm to 35 nm. The specimen coated with 1.0 wt.% silica showed the maximum relative density of 96.7% with high dielectric constant (12.78 × 104) and low dielectric loss (0.005) at 20°C after sintering at 1000°C for 6 h.

Montmorillonite-Alginate Composites as a Drug delivery System: Intercalation and In vitro Release of Diclofenac sodium

PubMed Central

Kevadiya, B. D.; Patel, H. A.; Joshi, G. V.; Abdi, S. H. R.; Bajaj, H. C.

2010-01-01

Diclofenac sodium and alginate was intercalated into montmorillonite to form uniform sized beads by gelation method. The structure and surface morphology of the synthesized composite beads were characterized by powdered X-ray diffraction, Fourier transform infrared spectroscopy, thermo gravimetric analysis and scanning electron microscopy. Diclofenac release kinetics of the composite in simulated intestinal fluid medium (pH 7.4) and effect of montmorillonite content on the in vitro release of diclofenac from diclofenac-montmorillonite-alginate composites bead was investigated by UV/Vis spectrophotometer. Diclofenac encapsulation efficiency in the montmorillonite-alginate composites bead increases with an increase in the montmorillonite content. The control release of diclofenac from diclofenac-montmorillonite-alginate composites beads was observed to be better as compared to diclofenac-alginate beads. PMID:21969745

Growth, optical, ICP and thermal studies of nonlinear optical single crystal: Sodium acid phthalate (NaAP)

NASA Astrophysics Data System (ADS)

Mahadevan, M.; Arivanandhan, M.; Elangovan, K.; Anandan, P.; Ramachandran, K.

2017-07-01

Good quality single crystals of sodium acid phthalate (NaAP) were grown by slow evaporation technique. Single crystal X-ray diffraction study of the grown crystal reveals that the crystal belongs to orthorhombic system with space group B2ab. Fourier transform infrared spectrum confirms the presence of the functional groups of the grown material. Inductively coupled plasma emission spectroscopy analysis is used to confirm the presence of Na element in the sample. Thermal analysis of the NaAP crystal shows that the crystal is stable up to 140°C. Optical transmittance of the grown crystal was recorded in the wavelength range from 200 and 800 nm using UV-Vis-NIR spectrophotometer. The second harmonic generation of NaAP was analysed using Kurtz powder technique.

Luminescent silver(I) tert-butylethynide compounds with nicotinic/isonicotinic acid as ligands

NASA Astrophysics Data System (ADS)

Xie, Yi-Ming; Fan, Yue-Yue; Lin, Fu-Lin; Hu, Ting; Liu, Jia; Lu, Can-Zhong

2017-12-01

Solvothermal reaction of tBuC≡CAg, AgBF4 and nicotinic/isonicotinic acid in acetonitrile afforded two new silver(I) tert-butylethynide double salts, namely [(tBuC≡CAg)(AgL1)3] (HL1 = nicotinic acid) (1) and [(tBuC≡CAg)(AgL1)2] (HL2 = isonicotinic acid) (2). These compounds have been characterized by elemental analysis, infrared spectra, single-crystal X-ray analysis, X-ray powder diffraction, thermogravimetric analysis, UV-visible absorption spectra, and luminescent measurement. 1 exhibits a two-dimensional coordination network, and 2 features a three-dimensional coordination architecture. Luminescence measurements indicate that 1 shows a fluorescent emission band centered at 568 nm, and 2 exhibits an intense emission maximum at 550 nm and a shoulder peak at 436 nm.

Synthesis, characterization and antibacterial property of ZnO:Mg nanoparticles

NASA Astrophysics Data System (ADS)

Kompany, A.; Madahi, P.; Shahtahmasbi, N.; Mashreghi, M.

2012-09-01

Sol-gel method was successfully used for the synthesis of ZnO nanoparticles (NPs) doped with different concentrations of Mg and the structural, optical and antibacterial properties of the nanoparticles were studied. The synthesized ZnO:Mg powders were characterized using x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transformation Infrared (FTIR) and UV-Vis spectroscopy. It was revealed that the samples have hexagonal Wurtzite structure, and the phase segregation takes place for 15% Mg content. TEM images show that the average size of the particles is about 50 nm. Also, the antibacterial activities of the nanoparticles were tested against Escherichia coli (Gram negative) cultures. ZnO:Mg nanofluid showed good antibacterial activity which increases with the increase of NPs concentration, and decreases slightly with the amount of Mg.

Synthesis and characterization of ZnO incorporated magnetically recoverable KIT-6 as a novel and efficient catalyst in the preparation of symmetrical N, N‧-alkylidene bisamides

NASA Astrophysics Data System (ADS)

Saadati-Moshtaghin, Hamid Reza; Zonoz, Farrokhzad Mohammadi; Amini, Mostafa M.

2018-04-01

A novel magnetically recoverable nanocomposite consisting of the NiFe2O4 core and KIT-6 mesoporous silica shell incorporated with ZnO nanoparticles was constructed. This nanocomposite was characterized by Fourier transform infrared (FT-IR), powder X-ray diffraction (XRD), Brunauer Emmett Teller (BET), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). This new nanocomposite demonstrated a catalytic performance in the synthesis of symmetrical N,N‧-alkylidene bisamides at the condensation reaction under solvent-free conditions. The nanocatalyst could simply be recovered from the reaction environment by using an exterior magnet and reused five times without a remarkable losing in the catalytic property.

Optical properties of Dy3+ doped YBO3 phosphor

NASA Astrophysics Data System (ADS)

Nair, Ramya G.; Nigam, Sandeep; Sudarsan, V.; Vatsa, R. K.

2018-04-01

Dysprosium doped YBO3 luminescent particleis synthesized via poly-ol method and by subsequent annealing at 800°C. The synthesized material has been characterized for structure properties using powder X-ray diffraction (XRD) and Fourier transform infrared (FTIR)spectroscopy. Photoluminescence properties of these samples are studiedby means of steady state measurements and decay curve. The phosphor shows characteristic transitions of Dy3+ in the excitation and emission spectra. Colour purity is determined in terms of yellow/blue ratio, which is found to be 1.8. The higher ratio of yellow/blue indicates that Dy3+ preferentially occupies the asymmetric site in host lattice. The average lifetime is found to be 1.1ms. The chromatic properties of the phosphor have been found to have chromaticity coordinates x = 0.245, y = 0.274.

Synthesis and characterization of high-quality cobalt vanadate crystals and their applications in lithium-ion batteries

NASA Astrophysics Data System (ADS)

Bhuiyan, Md. Tofajjol Hossen; Rahman, Md. Afjalur; Rahman, Md. Atikur; Sultana, Rajia; Mostafa, Md. Rakib; Tania, Asmaul Husna; Sarker, Md. Abdur Razzaque

2016-12-01

High-quality cobalt vanadate crystals have been synthesized by solid-state reaction route. Structure and morphology of the synthesized powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR) spectroscopy. The XRD patterns revealed that the as prepared materials are of high crystallinity and high quality. The SEM images showed that the crystalline CoV2O6 material is very uniform and well separated, with particle (of) area 252 μm. The electronic and optical properties were investigated by impedance analyzer and UV-visible spectrophotometer. Temperature-dependent electrical resistivity was measured using four-probe technique. The crystalline CoV2O6 material is a semiconductor and its activation energy is 0.05 eV.

Spectral downshifting in MBO3:Nd3+ (M=Y, La) phosphor

NASA Astrophysics Data System (ADS)

Omanwar, S. K.; Sawala, N. S.

2017-11-01

The spectral downshifting (DS) from ultra-violet (UV)/visible (VIS) light to near infra-red (NIR) radiation in Nd3+ doped YBO3 and LaBO3 phosphors is reported. The prepared materials were characterized by X-ray powder diffraction (XRD) and photoluminescence (PL) properties along with time-decay curves were studied which confirmed the spectral DS from VIS to NIR radiation. This can be employed to overcome the spectral mismatch of crystalline silicon (c-Si) solar cell with solar spectrum. The prepared Nd3+ doped as prepared phosphors provide NIR emission (1052 nm) at excitation of 586 nm where response of c-Si solar cell was optimum. Thus spectral modification by mentioned phosphor can be utilized to improve solar cells performance. Hence these phosphors have potential application for photovoltaic (PV) technology.

Neutron and X-ray powder diffraction study of skutterudite thermoelectrics

DOE PAGES

Wang, H.; Kirkham, M. J.; Watkins, T. R.; ...

2016-02-17

N- and p-type filled-skutterudite materials prepared for thermoelectric power generation modules were analyzed by neutron diffraction at the POWGEN beam line of the Spallation Neutron Source (SNS) and X-ray diffraction (XRD). The skutterudite powders were processed by melt spinning, followed by ball milling and annealing. The n-type material consists of Ba–Yb–Co–Sb and the p-type material consists of Di–Fe–Ni–Sb or Di–Fe–Co–Sb (Di = didymium, an alloy of Pr and Nd). Powders for prototype module fabrication from General Motors and Marlow Industries were analyzed in this study. XRD and neutron diffraction studies confirm that both the n- and p-type materials have cubicmore » symmetry. Structural Rietveld refinements determined the lattice parameters and atomic parameters of the framework and filler atoms. The cage filling fraction was found to depend linearly on the lattice parameter, which in turn depends on the average framework atom size. Ultimately, this knowledge may allow the filling fraction of these skutterudite materials to be purposefully adjusted, thereby tuning the thermoelectric properties.« less

Synthesis of cerium oxide (CeO 2) by co-precipitation for application as a reference material for X-ray powder diffraction peak widths

DOE Office of Scientific and Technical Information (OSTI.GOV)

de Lima Batista, Anderson Márcio; Miranda, Marcus Aurélio Ribeiro; Martins, Fátima Itana Chaves Custódio

Several methods can be used to obtain, from powder diffraction patterns, crystallite size and lattice strain of polycrystalline samples. Some examples are the Scherrer equation, Williamson–Hall plots, Warren/Averbach Fourier decomposition, Whole Powder Pattern Modeling, and Debye function analysis. To apply some of these methods, it is necessary to remove the contribution of the instrument to the widths of the diffraction peaks. Nowadays, one of the main samples used for this purpose is the LaB6 SRM660b commercialized by the National Institute of Standard Technology; the width of the diffraction peak of this sample is caused only by the instrumental apparatus. However,more » this sample can be expensive for researchers in developing countries. In this work, the authors present a simple route to obtain micron-sized polycrystalline CeO 2that have a full width at half maximum comparable with the SRM660b and therefore it can be used to remove instrumental broadening.« less

Crystal structure determination of new antimitotic agent bis(p-fluorobenzyl)trisulfide.

PubMed

An, Haoyun; Hu, Xiurong; Gu, Jianming; Chen, Linshen; Xu, Weiming; Mo, Xiaopeng; Xu, Wanhong; Wang, Xiaobo; Xu, Xiao

2008-01-01

The purpose of this research was to investigate the physical characteristics and crystalline structure of bis(p-fluorobenzyl)trisulfide, a new anti-tumor agent. Methods used included X-ray single crystal diffraction, X-ray powder diffraction (XRPD), Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetric (DSC) and thermogravimetric (TG) analyses. The findings obtained with X-ray single crystal diffraction showed that a monoclinic unit cell was a = 12.266(1) A, b = 4.7757(4) A, c = 25.510(1) A, beta = 104.25(1) degrees ; cell volume = 1,448.4(2) A(3), Z = 4, and space group C2/c. The XRPD studies of the four crystalline samples, obtained by recrystallization from four different solvents, indicated that they had the same diffraction patterns. The diffraction pattern stimulated from the crystal structure data is in excellent agreement with the experimental results. In addition, the identical FT-IR spectra of the four crystalline samples revealed absorption bands corresponding to S-S and C-S stretching as well as the characteristic aromatic substitution. Five percent weight loss at 163.3 degrees C was observed when TG was used to study the decomposition process in the temperature range of 20-200 degrees C. DSC also allowed for the determination of onset temperatures at 60.4(1)-60.7(3) degrees C and peak temperatures at 62.1(3)-62.4(3) degrees C for the four crystalline samples studied. The results verified that the single crystal structure shared the same crystal form with the four crystalline samples investigated.

Structure and physicochemical properties of starches in lotus (Nelumbo nucifera Gaertn.) rhizome

PubMed Central

Yu, Huaguang; Cheng, Libao; Yin, Jingjing; Yan, Shunjun; Liu, Kejun; Zhang, Fengmin; Xu, Bin; Li, Liangjun

2013-01-01

The type and content of starch are believed to be the most critical factors in determining the storage and processing quality of lotus rhizome species, and the intention of this study is to survey the structure and properties of starches isolated from rhizomes of two lotus cultivars using X-ray powder diffraction, solid-state nuclear magnetic resonance spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, scanning electron microscope, differential scanning calorimetry, and rapid viscosity analyzer (RVA). Starch in rhizome of cultivar Meirenhong exhibited C-type X-ray diffraction pattern, while starch in rhizome of cultivar Wawalian showed A-type pattern. 13C cross-polarization magic-angle spinning nuclear magnetic resonance (13C CP-MAS NMR) also confirmed the polymorphs. The relative crystallinity of two starches was quantitatively estimated from two methods and compared. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) results indicated that the external regions of the starch granules had a great level of ordered structure. Starch granules in Meirenhong showed oval-shaped granules, while starch granules in Wawalian were elongated and oval in shape with relatively large size. Gelatinization temperatures of starch in Meirenhong and Wawalian were 330.5 and 342.4 K, respectively, and the gelatinization temperature range of Meirenhong was significantly wider than that of Wawalian. Starch in rhizome of cultivar Meirenhong showed lower pasting temperature, lower hot and cool viscosities, lower setback, and higher peak viscosity and breakdown than those of Wawalian in RVA pasting profiles at 6% starch concentration. PMID:24804031

Synthesis of Cu/CuO nanoparticles in mesoporous material by solid state reaction

NASA Astrophysics Data System (ADS)

Sohrabnezhad, Sh.; Valipour, A.

2013-10-01

The Mobil Composition of Matter No. 41 (MCM-41) containing 1.0 and 5.0 wt.% of Cu was synthesized under solid state reaction. The calcinations of samples were done at two different temperatures, 500 and 300 °C. X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) were used for samples characterization. Powder X-ray diffraction showed that when Cu(CH3COO)2 content is about 1.0 wt.% in Cu/MCM-41, the guest CuO-NPs and copper ions is formed on the silica channel wall, and more exists in the crystalline state. When Cu(CH3COO)2 content exceeds this value (5.0 wt.%), CuO nanoparticles and Cu2+ ions can be observed in low crystalline state. From the diffuse reflectance spectra it was confirmed that 5 wt.% Cu/MCM-41 sample calcined at 500 °C show plasmon resonance band due to Cu nanoparticles in the range between 500 and 600 nm and small copper clusters Cun in 450 nm. It also shows that some of the Cu2+ ions are present octahedrally in extraframework position in all samples. Both fourier transform infrared and diffuse reflectance spectra indicate that some of Cu2+ ions are tetrahedrally within the framework position in 1 wt.% Cu/MCM-41 samples. TEM images indicated that nanoparticles size of CuO is in range of 30-40 nm.

[X-ray diffraction and infrared spectrum analysis of fault gouge in Wenchuan seismic belt].

PubMed

Wang, Zheng-Yang; Cao, Jian-Jin; Luo, Song-Ying; Liao, Yi-Peng

2014-05-01

Wenchuan earthquake produced a series of co-seismic surface ruptures in Leigu and Zhaojiagou, and we collected samples of co-seismic fault gouge in the surface ruptures as well as the old gouge in the fault of Nanba. Testing The new and old fault gouge was tested with X-ray diffraction and infrared absorption spectra, and its characteristics such as mineral compositions, clay mineral contents and combinations were comprehensively analyzed. The results display obvious differences between the new and old fault gouge, showing that the old fault gouge is mainly composed of wall rock debris or milled powders, while the main components of new fault gouge are clay minerals. The assemblage of clay minerals composition shows that the environment of the fault activity was mainly warm and humid, and the clay minerals were mainly transformed by low temperature and low pressure dynamic metamorphism. And this also partly indicates that the latest way of the fault activity in this area may be a creeping. However the previous researches on the fault gouge of Wenchuan earthquake fault zone are mainly focused on its mechanical properties as well as its texture and structure, the research in this paper is to determine the physical and chemical environment of fault activity through the mineral compositions and clay mineral contents in the fault gouge characteristics, and this research has important scientific significance to the researches on the evolution of the fault environment and the activity mechanism of the earthquake.

Optical Properties of Natural Minerals in the Far-Infrared

NASA Astrophysics Data System (ADS)

Long, Larry Lavern

The reflectivity of natural mineral powders were measured in the far infrared. The complex indices of refraction were then determined by Kramers-Kronig analysis or dispersive analysis. The samples were constructed by pressing the powdered sample into a 13 mm diameter pellet. A few of the samples that were measured were kaolin, illite, and montmorillonite, clay samples that could not be obtained in large single crystals. For calcite and gypsum crystals a comparison between the single crystal measurements and powder measurements was done to determine the effect of sample preparation on the measured spectra.

Influence of Cu substitution on the structural ordering, photocatalytic activity and photoluminescence emission of Ag3-2xCuxPO4 powders

NASA Astrophysics Data System (ADS)

Pereira, Wyllamanney da S.; Sczancoski, Júlio C.; Calderon, Yormary N. C.; Mastelaro, Valmor R.; Botelho, Gleice; Machado, Thales R.; Leite, Edson R.; Longo, Elson

2018-05-01

Materials presenting high photocatalytic performance and interesting photoluminescence emissions are promising candidates for photodegradation of organic pollutants discharged into natural waters as well as for development of new electro-optical devices, respectively. In this study, Ag3-2xCuxPO4 (x = 0.00, 0.01, 0.02, 0.04 and 0.08) powders were synthesized by the precipitation method. The long- and short-range structural ordering was affected when the copper (Cu) content was increased in the lattice, as identified by X-ray diffraction patterns, Fourier transform infrared spectroscopy and Raman spectroscopy, respectively. The field emission scanning electron microscope and transmission electron microscope revealed a particle system composed of irregular spherical-like microcrystals. The presence of Cu as well as its real amount in the samples were confirmed by means of X-ray photoelectron spectroscopy and inductively coupled plasma-atomic emission spectrometry, respectively. On increasing Cu level, a slight variation was noted on the photocatalytic activity of Ag3-2xCuxPO4 powders for degradation of rhodamine B under visible light irradiation. A photodegradation mechanism was proposed in details. The photoluminescence emissions were explained by electronic transitions involving intermediary energy levels in the band gap. The origin these energy levels was related to defects caused by the substitution of Ag by Cu in the crystalline structure.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rounaghi, S.A., E-mail: s.a.rounaghi@gmail.com; Kiani Rashid, A.R.; Eshghi, H., E-mail: heshghi@ferdowsi.um.ac.ir

Decomposition of melamine was studied by solid state reaction of melamine and aluminum powders during high energy ball-milling. The milling procedure performed for both pure melamine and melamine/Al mixed powders as the starting materials for various times up to 48 h under ambient atmosphere. The products were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results revealed that Al causes melamine deammoniation at the first stages of milling and further milling process leads to the s-triazine ring degradation while nano-crystallite hexagonal aluminum nitride (h-AlN) was the main solid product. Comparison to milling process, the possibility ofmore » the reaction of melamine with Al was also investigated by thermal treatment method using differential scanning calorimeter (DSC) and thermo gravimetric analyzer (TGA). Melamine decomposition occurred by thermal treatment in the range of 270-370 Degree-Sign C, but no reaction between melamine and aluminum was observed. - Graphical Abstract: Mechanochemical reaction of melamine with Al resulted in the formation of nanocrystalline AlN after 7 h milling time Highlights: Black-Right-Pointing-Pointer High energy ball milling of melamine and aluminum results decomposition of melamine with elimination of ammonia. Black-Right-Pointing-Pointer Nano-crystalline AlN was synthesized by the mechanochemical route. Black-Right-Pointing-Pointer Milling process has no conspicuous effect on pure melamine degradation. Black-Right-Pointing-Pointer No reaction takes place by heating melamine and aluminum powder mixture in argon.« less

Structure-property relationships of iron-hydroxyapatite ceramic matrix nanocomposite fabricated using mechanosynthesis method.

PubMed

Nordin, Jamillah Amer; Prajitno, Djoko Hadi; Saidin, Syafiqah; Nur, Hadi; Hermawan, Hendra

2015-06-01

Hydroxyapatite (HAp) is an attractive bioceramics due to its similar composition to bone mineral and its ability to promote bone-implant interaction. However, its low strength has limited its application as load bearing implants. This paper presented a work focusing on the improvement of HAp mechanical property by synthesizing iron (Fe)-reinforced bovine HAp nanocomposite powders via mechanosynthesis method. The synthesis process was performed using high energy milling at varied milling time (3, 6, 9, and 12h). The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and scanning electron microscopy (SEM). Its mechanical properties were investigated by micro-Vicker's hardness and compression tests. Results showed that milling time directly influenced the characteristics of the nanocomposite powders. Amorphous BHAp was formed after 9 and 12h milling in the presence of HPO4(2-) ions. Continuous milling has improved the crystallinity of Fe without changing the HAp lattice structure. The nanocomposite powders were found in spherical shape, agglomerated and dense after longer milling time. The hardness and Young's modulus of the nanocomposites were also increased at 69% and 66%, respectively, as the milling time was prolonged from 3 to 12h. Therefore, the improvement of the mechanical properties of nanocomposite was attributed to high Fe crystallinity and homogenous, dense structure produced by mechanosynthesis. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and characterization of β-Ni(OH)2 embedded with MgO and ZnO nanoparticles as nanohybrids for energy storage devices

NASA Astrophysics Data System (ADS)

Kumar, C. R. Ravi; Santosh, M. S.; Nagaswarupa, H. P.; Prashantha, S. C.; Yallappa, S.; Kumar, M. R. Anil

2017-06-01

In this study, the electrode material (nickel hydroxide powder) has been synthesized by a co-precipitation method using sodium hydroxide and nickel sulphate as precipitator and nickel source, respectively. The obtained nickel hydroxide powder has been subsequently embedded with biosynthesized MgO and ZnO nanoparticles as nanohybrids, which have been investigated as a novel hybrid electrode material for power-storage applications. The powder x-ray diffraction pattern of nickel hydroxide (Ni(OH)2)-based nanohybrid materials reveals a typical β-phase. Fourier transform infrared spectroscopy confirms the embedded structures of nanohybrids and thermal stability by thermogravimetry and differential thermal) analysis. The electrochemical properties of these materials have been studied using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The specific capacitance values are found to be 439, 1076, and 622 F g-1 for bare β-Ni(OH)2, and for β-Ni(OH)2 embedded with ZnO and MgO nanohybrids, respectively, at a scan rate of 10 mVs-1. The enhanced capacitance of nanohybrids is also evident from EIS measurements. Galvanostatic charge-discharge tests for these designed nanohybrids show excellent capacitance performance in battery and supercapacitor applications. These innovative results could be considered for the expansion of novel resources to scale for power-storage applications and may contribute to the development of this niche area at large.

Optimizing adsorption of blue pigment from wastewater by nano-porous modified Na-bentonite using spectrophotometry based on response surface method

NASA Astrophysics Data System (ADS)

Moradi, Neshat; Salem, Shiva; Salem, Amin

2018-03-01

This work highlighted the effective activation of bentonite paste to produce nano-porous powder for removal of cationic dye from wastewater. The effects of activation parameters such as soda and moisture contents, ageing time and temperature were analyzed using response surface methodology (RSM). The significance of independent variables and their interactions were tested by blending the obtained powders with wastewater and then the adsorption was evaluated, spectrophotometrically. The experiments were carried out by preparation of pastes according to response surface methodology and central composite design, which is the standard method, was used to evaluate the effects and interactions of four factors on the treatment efficiency. RSM was demonstrated as an appropriate approach for optimization of alkali activation. The optimal conditions obtained from the desirable responses were 5.0 wt% soda and 45.0 wt% moisture, respectively in which the powder activation was carried out at 150 °C. In order to well understand the role of nano-structured material on dye removal, the adsorbents were characterized through X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and Brunauer-Emmett-Teller surface area measurement. Finally, the analysis clearly demonstrates that the dye removal onto prepared adsorbent is well fitted with Langmuir isotherm compared to the other isotherm models. The low cost of material and facile process support the further development for commercial application purpose.

Near-infrared photoluminescence in La{sub 0.98}AlO{sub 3}: {sub 0.02}Ln{sup 3+}(Ln = Nd/Yb) for sensitization of c-Si solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sawala, N. S., E-mail: nssawala@gmail.com; Koparkar, K. A.; Omanwar, S. K.

2016-05-06

The host matrix LaAlO{sub 3} was synthesized by conventional solid state reaction method in which the Nd{sup 3+} ions and Yb{sup 3+} ions successfully doped at 2mol% concentrations. The phase purity was confirmed by X ray powder diffraction (XRD) method. The photoluminescence (PL) properties were studied by spectrophotometer in near infra red (NIR) and ultra violet visible (UV-VIS) region. The Nd{sup 3+} ion doped LaAlO{sub 3} converts a visible (VIS) green photon (587 nm) into near infrared (NIR) photon (1070 nm) while Yb{sup 3+} ion doped converts ultra violet (UV) photon (221 nm) into NIR photon (980 nm). The La{sub 0.98}AlO{sub 3}: {sub 0.02}Ln{supmore » 3+}(Ln = Nd / Yb) can be potentiality used for betterment of photovoltaic (PV) technology. This result further indicates its potential application as a luminescence converter layer for enhancing solar cells performance.« less

Synthesis, spectroscopic, thermal and anticancer studies of metal-antibiotic chelations: Ca(II), Fe(III), Pd(II) and Au(III) chloramphenicol complexes

NASA Astrophysics Data System (ADS)

Al-Khodir, Fatima A. I.; Refat, Moamen S.

2016-09-01

Four Ca(II), Fe(III), Pd(II) and Au(III) complexes of chloramphenicol drug have been synthesized and well characterized using elemental analyses, (infrared, electronic, and 1H-NMR) spectra, magnetic susceptibility measurement, and thermal analyses. Infrared spectral data show that the chloramphenicol drug coordinated to Ca(II), Pd(II) and Au(III) metal ions through two hydroxyl groups with 1:1 or 1:2 M ratios, but Fe(III) ions chelated towards chloramphenicol drug via the oxygen and nitrogen atoms of amide group with 1:2 ratio based on presence of keto↔enol form. The X-ray powder diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) techniques were used to identify the nano-size particles of both iron(III) and gold(III) chloramphenicol complexes. The antimicrobial assessments of the chloramphenicol complexes were scanned and collected the results against of some kind of bacteria and fungi. The cytotoxic activity of the gold(III) complex was tested against the human colon carcinoma (HCT-116) and human hepatocellular carcinoma (HepG-2) tumor cell lines.

Addressing the amorphous content issue in quantitative phase analysis : the certification of NIST SRM 676a.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cline, J. P.; Von Dreele, R. B.; Winburn, R.

2011-07-01

A non-diffracting surface layer exists at any boundary of a crystal and can comprise a mass fraction of several percent in a finely divided solid. This has led to the long-standing issue of amorphous content in standards for quantitative phase analysis (QPA). NIST standard reference material (SRM) 676a is a corundum ({alpha}-Al{sub 2}O{sub 3}) powder, certified with respect to phase purity for use as an internal standard in powder diffraction QPA. The amorphous content of SRM 676a is determined by comparing diffraction data from mixtures with samples of silicon powders that were engineered to vary their specific surface area. Undermore » the (supported) assumption that the thickness of an amorphous surface layer on Si was invariant, this provided a method to control the crystalline/amorphous ratio of the silicon components of 50/50 weight mixtures of SRM 676a with silicon. Powder diffraction experiments utilizing neutron time-of-flight and 25 keV and 67 keV X-ray energies quantified the crystalline phase fractions from a series of specimens. Results from Rietveld analyses, which included a model for extinction effects in the silicon, of these data were extrapolated to the limit of zero amorphous content of the Si powder. The certified phase purity of SRM 676a is 99.02% {+-} 1.11% (95% confidence interval). This novel certification method permits quantification of amorphous content for any sample of interest, by spiking with SRM 676a.« less

Addressing the Amorphous Content Issue in Quantitative Phase Analysis: The Certification of NIST Standard Reference Material 676a

DOE Office of Scientific and Technical Information (OSTI.GOV)

J Cline; R Von Dreele; R Winburn

2011-12-31

A non-diffracting surface layer exists at any boundary of a crystal and can comprise a mass fraction of several percent in a finely divided solid. This has led to the long-standing issue of amorphous content in standards for quantitative phase analysis (QPA). NIST standard reference material (SRM) 676a is a corundum ({alpha}-Al{sub 2}O{sub 3}) powder, certified with respect to phase purity for use as an internal standard in powder diffraction QPA. The amorphous content of SRM 676a is determined by comparing diffraction data from mixtures with samples of silicon powders that were engineered to vary their specific surface area. Undermore » the (supported) assumption that the thickness of an amorphous surface layer on Si was invariant, this provided a method to control the crystalline/amorphous ratio of the silicon components of 50/50 weight mixtures of SRM 676a with silicon. Powder diffraction experiments utilizing neutron time-of-flight and 25 keV and 67 keV X-ray energies quantified the crystalline phase fractions from a series of specimens. Results from Rietveld analyses, which included a model for extinction effects in the silicon, of these data were extrapolated to the limit of zero amorphous content of the Si powder. The certified phase purity of SRM 676a is 99.02% {+-} 1.11% (95% confidence interval). This novel certification method permits quantification of amorphous content for any sample of interest, by spiking with SRM 676a.« less

Application of Fourier transform infrared spectroscopy to silica diagenesis: The opal-A to opal-CT transformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rice, S.B.; Freund, H.; Huang, W.L.

An important goal in silica diagenesis research is to understand the kinetics of opal transformation from noncrystalline opal-A to the disordered silica polymorph opal-CT. Because the conventional technique for monitoring the transformation, powder X-ray diffraction (XRD), is applicable only to phases with long-range order, the authors used Fourier transform infrared spectroscopy (FTIR) to monitor the transformation. They applied this technique, combined with XRD and TEM, to experimental run products and natural opals from the Monterey Formation and from siliceous deposits in the western Pacific Ocean. Using a ratio of two infrared absorption intensities ({omega} = I{sub 472 cm{sup {minus}1}}/I{sub 500more » cm{sup {minus}1}}), the relative proportions of opal-A and opal-CT can be determined. The progress of the transformation is marked by changes in slope of {omega} vs. depth or time when a sufficient stratigraphic profile is available. There are three stages in the opal-A to opal-CT reaction: (1) opal-A dissolution; (2) opal-CT precipitation, whose end point is marked by completion of opal-A dissolution; and (3) opal-CT ordering, during which tridymite stacking is eliminated in favor of crystobalite stacking.« less

Additional evidence from x-ray powder diffraction patterns that icosahedral quasi-crystals of intermetallic compounds are twinned cubic crystals

PubMed Central

Pauling, Linus

1988-01-01

Analysis of the measured values of Q for the weak peaks (small maxima, usually considered to be background fluctuations, “noise”) on the x-ray powder diffraction curves for 17 rapidly quenched alloys leads directly to the conclusion that they are formed by an 820-atom or 1012-atom primitive cubic structure that by icosahedral twinning produces the so-called icosahedral quasi-crystals. PMID:16593948

Test and Delivery of the Chemin Mineralogical Instrument for Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Blake, D. F.; Vaniman, D.; Anderson, R.; Bish, D.; Chipera, S.; Chemtob, S.; Crisp, J.; DesMarais, D. J.; Downs, R.; Feldman, S.;

Melting point suppression in new lanthanoid(III) ionic liquids by trapping of kinetic polymorphs: an in situ synchrotron powder diffraction study.

PubMed

Chesman, Anthony S R; Yang, Mei; Mallick, Bert; Ross, Tamsyn M; Gass, Ian A; Deacon, Glen B; Batten, Stuart R; Mudring, Anja-Verena

2012-01-04

The complexes (N(4444))(3)[Ln(dcnm)(6)] (Ln = La-Nd, Sm; N(4444) = tetrabutylammonium) display a decrease in the melting point upon fast cooling from a melt, which is shown by in situ synchrotron based X-ray powder diffraction to be due to the formation of a second, less thermodynamically stable, polymorph. This journal is © The Royal Society of Chemistry 2012

Effects of N precursor on the agglomeration and visible light photocatalytic activity of N-doped TiO2 nanocrystalline powder.

PubMed

Hu, Yulong; Liu, Hongfang; Rao, Qiuhua; Kong, Xiaodong; Sun, Wei; Guo, Xingpeng

2011-04-01

N-doped TiO2 nanocrystalline powders were prepared by the sol-gel method using various N precursors, including triethylamine, hydrazine hydrate, ethylenediamine, ammonium hydroxide, and urea. The samples were characterized by X-ray diffraction, N2 adsorption isotherms, transmission electron microscopy, ultraviolet-visible diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic activities of as-prepared samples under irradiation of visible light (lambda > 405 nm) were evaluated by photodecomposition of methyl orange. The alkalinity of N precursor was found to play a key role in the gel process. The N precursor with moderate alkalinity causes TiO2 nanoparticles to be sol-transformed into a loosely agglomerated gel. This transformation facilitates the preparation of an N-doped TiO2 powder with small nanocrystal size, large specific surface area, and high N doping level and results in high visible light photocatalytic activity. The N in TiO2 with N is binding energy at 399-400 eV may be assigned to the N-H species located in interstitial sites of TiO2 lattice which is the active N species responsible for the visible light photocatalytic activity. The N species of N 1s peak at 402 and 405 eV are ineffective to the visible light photocatalytic activity and may inhibit the photocatalytic activity. Moreover, a TiO2 nanoparticle powder with large specific area can be achieved by using urea as a template and then by using ammonium hydroxide to transform the sol into gel.

Clifford G. Shull, Neutron Diffraction, Hydrogen Atoms, and Neutron

Science.gov Websites

Analysis of NaH and NaD, DOE Technical Report, April 1947 The Diffraction of Neutrons by Crystalline Powders; DOE Technical Report; 1948 Neutron Diffraction Studies, DOE Technical Report, 1948 Laue Structure of Thorium and Zirconium Dihydrides by X-ray and Neutron Diffraction, DOE Technical Report, April

Synthesis, characterization, temperature dependent electrical and magnetic properties of Ca3Co4O9 by a starch assisted sol-gel combustion method

NASA Astrophysics Data System (ADS)

Agilandeswari, K.; Ruban Kumar, A.

2014-09-01

In this present work we discussed the synthesis of pure Ca3Co4O9 ceramic powder by a starch assisted sol-gel combustion method. The products were characterized by powder X-ray diffraction (XRD), thermogravimetric and differential thermal analyses (TGA-DTA), Fourier transformation infrared spectroscopy (FTIR), scanning electron microscope (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). X-ray diffraction pattern confirmed the formation of single phase Ca3Co4O9 at a sintering temperature of 1073 K, and it is also confirmed in the thermal analysis. SEM images indicate the presence of diffused microporous sphere like morphology and the grain sizes are in the range of 150-300 nm. Optical properties of Ca3Co4O9 ceramic show a band gap at an energy level of 2.10 eV. A maximum electrical resistivity of 0.002 mΩ cm was exhibited by Ca3Co4O9 that was decreased to 0.0012 mΩ cm, when the temperature increased from 300 K to 473 K. Dielectric studies were conducted at various temperatures from room temperature to 673 K and the results indicate that the space charge polarization contributes to the conduction mechanism. It also shows that the dielectric relaxation with activation energy is 0.96 eV. The magnetic properties as a function of temperature represent the ferri-paramagnetic phase transition at above 50 K. M-H curve shows the hysteresis loop with saturation magnetization (Ms) and confirms the presence of soft magnetic materials.

Synthesis, growth, structural, spectral, thermal, chemical etching, linear and nonlinear optical and mechanical studies of an organic single crystal 4-chloro 4-nitrostilbene (CONS): a potential NLO material.

PubMed

Dinakaran, Paul M; Kalainathan, S

2013-07-01

4-Chloro 4-nitrostilbene (CONS) a new organic nonlinear optical material has been synthesized. Employing slow evaporation method, good optical quality single crystals (dimensions up to 6×2×3 mm(3)) have been grown using ethyl methyl ketone (EMK) as a solvent. The grown crystals have been subjected to various characterizations such as single crystal X-ray diffraction, powder XRD, Fourier Transform Infrared spectroscopy (FTIR), proton NMR, solid UV absorption, SHG studies. Single crystal X-ray diffraction reveals that the crystal system belongs to monoclinic with noncentrosymmetric space group P21. The UV-Vis absorption spectrum has been recorded and found that the cut off wavelength is 380 nm. Functional groups and the structure of the title compound have been confirmed by FTIR and (1)H NMR spectroscopic analyses respectively. Molecular mass of the CONS confirmed by the high resolution mass spectral analysis .The thermal behavior of the grown crystal has been studied by TG/DTA analysis and it shows the melting point is at 188.66 °C. Dislocations and growth pattern present in the grown crystal revealed by the etching study. The mechanical strength of the CONS crystal has been studied by Vicker's hardness measurement. The SHG efficiency of the grown crystal has been determined by Kurtz and Perry powder test which revealed that the CONS crystal (327 mV) has 15 times greater efficiency than that of KDP (21.7 mV). Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of powder compaction on radiation-thermal synthesis of lithium-titanium ferrites

NASA Astrophysics Data System (ADS)

Surzhikov, A. P.; Lysenko, E. N.; Vlasov, V. A.; Malyshev, A. V.; Korobeynikov, M. V.; Mikhailenko, M. A.

2017-01-01

Effect of powder compaction on the efficiency of thermal and radiation-thermal synthesis of lithium-substituted ferrites was investigated by X-Ray diffraction and specific magnetization analysis. It was shown that the radiation-thermal heating of compacted powder reagents mixture leads to an increase in efficiency of lithium-titanium ferrites synthesis.

Synthesis of nano-forsterite powder by making use of natural silica sand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nurbaiti, Upik, E-mail: upik-nurbaiti@mail.unnes.ac.id; Department of Physics, Faculty of Mathematics and Natural Sciences Semarang State University Jl. Raya Sekaran GunungPati, Semarang 50221; Suud, Fikriyatul Azizah

2016-02-08

Nano-forsterite powder with natural silica sand and magnesium powder as the raw materials have been succesfully synthesized. The silica sand was purified followed by a coprecipitation process to obtain colloidal silica. The magnesium powder was dissolved in a chloric acid solution to obtain MgCl{sub 2} solution. The nanoforsterite powder was synthesised using a sol-gel method which included the mixing the colloidal silica and the MgCl{sub 2} solution with various aging and filtering processes. The samples were dried at 100 °C using a hot plate and then the dried powders were calcinated at 900 °C for 2 hours. The samples weremore » characetised for their elements and phase compositions using X-ray Flourescence (XRF) and X-ray Diffraction (XRD) methods, respectively. The diffraction data were qualitatively analyzed using Match!2 software and quantitatively using Rietica software. The crystallite size was verified using Transmission Electron Microscopy (TEM). Results of XRD data analysis showed that the forsterite content reached up to 90.5% wt. The TEM average crystallite size was approximately 53(6) nm.« less

Crystal structure of methylprednisolone acetate form II, C 24H 32O 6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wheatley, Austin M.; Kaduk, James A.; Gindhart, Amy M.

The crystal structure of methylprednisolone acetate form II, C 24H 32O 6, has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Methylprednisolone acetate crystallizes in space groupP2 12 12 1(#19) witha= 8.17608(2),b= 9.67944(3),c= 26.35176(6) Å,V= 2085.474(6) Å 3, andZ= 4. Both hydroxyl groups act as hydrogen bond donors, resulting in a two-dimensional hydrogen bond network in theabplane. C–H…O hydrogen bonds also contribute to the crystal energy. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1412.

Comparative study of proteasome inhibitory, synergistic antibacterial, synergistic anticandidal, and antioxidant activities of gold nanoparticles biosynthesized using fruit waste materials.

PubMed

Patra, Jayanta Kumar; Baek, Kwang-Hyun

The aim of this study was to compare the biological synthesis of gold nanoparticles (AuNPs) generated using the aqueous extracts of outer oriental melon peel (OMP) and peach. The synthesized OMP-AuNPs and peach extract (PE)-AuNPs were characterized by ultraviolet-visible spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray analysis, X-ray powder diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The surface plasmon resonance spectra were obtained at 545 nm and 540 nm for OMP-AuNPs and PE-AuNPs, respectively. The estimated absolute crystallite size of the synthesized AuNPs was calculated to be 78.11 nm for OMP-AuNPs and 39.90 nm for PE-AuNPs based on the Scherer equation of the X-ray powder diffraction peaks. Fourier transform infrared spectroscopy results revealed the involvement of bioactive compounds present in OMP and peach extracts in the synthesis and stabilization of synthesized AuNPs. Both the OMP-AuNPs and PE-AuNPs showed a strong antibacterial synergistic activity when combined with kanamycin (9.38-20.45 mm inhibition zones) and rifampicin (9.52-25.23 mm inhibition zones), and they also exerted a strong synergistic anticandidal activity (10.09-15.47 mm inhibition zones) when combined with amphotericin B against five pathogenic Candida species. Both the OMP-AuNPs and PE-AuNPs exhibited a strong antioxidant potential in terms of 1,1-diphenyl-2-picrylhydraxyl radical scavenging, nitric oxide scavenging, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging, and a reducing power, along with a strong proteasome inhibitory potential that could be useful in cancer drug delivery and cancer treatments. The PE-AuNPs showed comparatively higher activity than OMP-AuNPs, which could be attributed to the presence of rich bioactive compounds in the PE that acted as reducing and capping agents in the synthesis of PE-AuNPs. Overall, the results of the current investigation highlighted a novel green technology for the synthesis of AuNPs using food waste materials and their potential applications in the biomedical, pharmaceutical, and cosmetic industries.

Effects of Peripheral Architecture on the Properties of Aryl Polyhedral Oligomeric Silsesquioxanes

DTIC Science & Technology

2012-07-26

POSS) molecules are described. These POSS materials were synthesized in our laboratory and characterized by single-crystal and powder X - ray diffraction ...powder X - ray diffraction (XRD), where applicable. 1H, 13C, and 29Si NMR spectra were obtained on Bruker 300 and 400 MHz spectrometers using 5 mm o.d...degree of cage ordering during precipitation. Referring back to Figure 14, strong X - ray scattering peaks in the spectra for 1 in the d- spacing range

[Application of infrared spectroscopy technique to protein content fast measurement in milk powder based on support vector machines].

PubMed

Wu, Di; Cao, Fang; Feng, Shui-Juan; He, Yong

2008-05-01

In the present study, the JASCO Model FTIR-4 000 fourier transform infrared spectrometer (Japan) was used, with a valid range of 7 800-350 cm(-1). Seven brands of milk powder were bought in a local supermarket. Milk powder was compressed into a uniform tablet with a diameter of 5 mm and a thickness of 2 mm, and then scanned by the spectrometer. Each sample was scanned 40 times and the data were averaged. About 60 samples were measured for each brand, and data for 409 samples were obtained. NIRS analysis was based on the range of 4 000 to 6 666 cm(-1), while MIRS analysis was between 400 and 4 000 cm(-1). The protein content was determined by kjeldahl method and the factor 6.38 was used to convert the nitrogen values to protein. The protein content value is the weight of protein per 100 g of milk powder. The NIR data of the milk powder exhibited slight differences. Univariate analysis was not really appropriate for analyzing the data sets. From NIRS region, it could be observed that the trend of different curves is similar. The one around 4 312 cm(-1) embodies the vibration of protein. From MIRS region, it could be determined that there are many differences between transmission value curves. Two troughs around 1 545 and 1 656 cm(-1) stand for the vibration of amide I and II bands of protein. The smoothing way of Savitzky-Golay with 3 segments and zero polynomials and multiplicative scatter correction (MSC) were applied for denoising. First 8 important principle components (PCs), which were obtained from principle component analysis (PCA), were the optimal input feature subset. Least-squares support vector machines was applied to build the protein prediction model based on infrared spectral transmission value. The prediction result was better than that of traditional PLS regression model as the determination coefficient for prediction (R(p)2) is 0.951 7 and root mean square error for prediction (RMSEP) is 0.520 201. These indicate that LS-SVM is a powerful tool for spectral analysis. Moreover, the study compared the prediction results based on near infrared spectral data and mid-infrared spectral data. The results showed that the performance of the model with mid-infrared spectral data was better than the one with near infrared spectra data. It was concluded that infrared spectroscopy technique can do the quantification of protein content in milk powder fast and non-destructively and the process was simple and easy to operate. The results of this study can be used for the design of a simple and non-destructive spectra sensor for the quantitative of protein content in milk powder.

Testing the limits of sensitivity in a solid-state structural investigation by combined X-ray powder diffraction, solid-state NMR, and molecular modelling.

PubMed

Filip, Xenia; Borodi, Gheorghe; Filip, Claudiu

2011-10-28

A solid state structural investigation of ethoxzolamide is performed on microcrystalline powder by using a multi-technique approach that combines X-ray powder diffraction (XRPD) data analysis based on direct space methods with information from (13)C((15)N) solid-state Nuclear Magnetic Resonance (SS-NMR) and molecular modeling. Quantum chemical computations of the crystal were employed for geometry optimization and chemical shift calculations based on the Gauge Including Projector Augmented-Wave (GIPAW) method, whereas a systematic search in the conformational space was performed on the isolated molecule using a molecular mechanics (MM) approach. The applied methodology proved useful for: (i) removing ambiguities in the XRPD crystal structure determination process and further refining the derived structure solutions, and (ii) getting important insights into the relationship between the complex network of non-covalent interactions and the induced supra-molecular architectures/crystal packing patterns. It was found that ethoxzolamide provides an ideal case study for testing the accuracy with which this methodology allows to distinguish between various structural features emerging from the analysis of the powder diffraction data. This journal is © the Owner Societies 2011

Composition and particle size of electrolytic copper powders prepared in water-containing dimethyl sulfoxide electrolytes

NASA Astrophysics Data System (ADS)

Mamyrbekova, Aigul'; Abzhalov, B. S.; Mamyrbekova, Aizhan

2017-07-01

The possibility of the electroprecipitation of copper powder via the cathodic reduction of an electrolyte solution containing copper(II) nitrate trihydrate and dimethyl sulfoxide (DMSO) is shown. The effect electrolysis conditions (current density, concentration and temperature of electrolyte) have on the dimensional characteristics of copper powder is studied. The size and shape of the particles of the powders were determined by means of electron microscopy; the qualitative composition of the powders, with X-ray diffraction.

Nd³⁺-Yb³⁺ doped powder for near-infrared optical temperature sensing.

PubMed

Rakov, Nikifor; Maciel, Glauco S

2014-07-01

Er³⁺ doped powders are generally used for fluorescence-based temperature sensing application when near-infrared lasers are the excitation sources of choice. The fluorescence of Er³⁺ is produced by nonlinear (upconversion) processes, which generate strong internal heat. Lowering the excitation power causes drastic reduction of the fluorescence signal, and as a consequence the sensor applicability of Er³⁺ doped powders becomes compromised. Here we propose the use of the downconverted fluorescence of Yb³⁺ produced by efficient energy transfer from Nd³⁺ as an alternative temperature sensing system. Our results are presented for yttrium silicate powders prepared by combustion synthesis.

Crystallographic Determination of Molecular Parameters for K2SiF6: A Physical Chemistry Laboratory Experiment.

ERIC Educational Resources Information Center

Loehlin, James H.; Norton, Alexandra P.

1988-01-01

Describes a crystallography experiment using both diffraction-angle and diffraction-intensity information to determine the lattice constant and a lattice independent molecular parameter, while still employing standard X-ray powder diffraction techniques. Details the method, experimental details, and analysis for this activity. (CW)

Synthesis, structural, optical and thermal studies of an organic nonlinear optical 4-aminopyridinium maleate single crystal.

PubMed

Pandi, P; Peramaiyan, G; Kumar, M Krishna; Kumar, R Mohan; Jayavel, R

2012-03-01

Synthesis and growth of a novel organic nonlinear optical (NLO) crystal of 4-aminopyridinium maleate (4APM) in larger size by the slow evaporation solution growth technique are reported. Single crystal and powder X-ray diffraction analyses reveal that 4APM crystallizes in monoclinic system with space group P2(1) with cell parameters a=8.140(4)Å, b=5.457(5)Å, c=10.926(10)Å and volume=481.4(7)Å(3). The grown crystal has been characterized by Fourier transform infrared and UV-visible spectral analyses. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) have been carried out to study its thermal properties. Dielectric measurements have been carried out to study the distribution of charges within the crystal. The mechanical strength of the crystal has been studied by using Vickers' microhardness test. The etching studies have been carried out on the grown crystal. The Kurtz and Perry powder SHG technique confirms the NLO property of the grown crystal and the SHG efficiency of 4APM was found to be 4.8 times greater than that of KDP crystal. Copyright © 2011 Elsevier B.V. All rights reserved.

Influence of nickel substitution on crystal structure and magnetic properties of strontium ferrite preparation via sol-gel auto-combustion route

NASA Astrophysics Data System (ADS)

Roohani, Ebrahim; Arabi, Hadi; Sarhaddi, Reza

2018-01-01

In this research, SrFe12-xNixO19 (x = 0 - 1) hexagonal ferrites were prepared by sol-gel auto-combustion method. Effect of Ni substitution on structural, morphological and magnetic properties of nanoparticles was investigated by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM), respectively. The XRD results confirmed that all samples with x ≤ 0.5 have single phase M-type strontium ferrite structure, whereas for the SrFe12-xNixO19 samples with x > 0.5, the spinel NiFe2O4 phase has also appeared. The lattice parameters and crystallite sizes of the powders were concluded from the XRD data and Williamson-Hall method. Magnetic analyses showed that the coercivity of powders decreased from 5672 Oe to 639 Oe while the saturation magnetization increased from 74 emu/g to 81 emu/g with nickel substitution. The results of this study suggest that the strontium hexaferrites doped with Ni are suitable for applications in high density magnetic recording media as well as microwave devices because of their promising magnetic properties.

Synthesis of porous Cu-BTC with ultrasonic treatment: Effects of ultrasonic power and solvent condition.

PubMed

Israr, Farrukh; Kim, Duk Kyung; Kim, Yeongmin; Oh, Seung Jin; Ng, Kim Choon; Chun, Wongee

2016-03-01

Cu-BTC (BTC=1,3,5-benzenetricarboxylate) metal organic framework (MOF) was synthesized using different solvent conditions with ultrasonic treatment. Solvent mixtures of water/N,N-dimethylformamide (DMF), water/ethanol were used for the reactions with or without a variety of bases under 20 kHz ultrasonically treated conditions. Prepared crystals were purified through 30 min of sonication to remove unreacted chemicals. Treatment time and ultrasonic power effects were compared to get optimum synthetic condition. The characterization of MOF powders was performed by scanning electron microscopy, X-ray powder diffraction, infrared-spectroscopy, thermo-gravimetric analysis and specific surface determination using the BET method. Isolated crystal yields varied with different solvent and applied ultrasonic power conditions. A high isolated crystal yield of 86% was obtained from water/ethanol/DMF solvent system after 120 min of ultrasonic treatment at 40% power of 750 W. Different solvent conditions led to the formation of Cu-BTC with different surface area, and an extremely high surface area of 1430 m(2)/g was obtained from the crystals taken with the solvent condition of water:DMF=70:30. Copyright © 2015 Elsevier B.V. All rights reserved.

Structural, microstructural and magnetic evolution in cryo milled carbon doped MnAl.

PubMed

Fang, Hailiang; Cedervall, Johan; Hedlund, Daniel; Shafeie, Samrand; Deledda, Stefano; Olsson, Fredrik; von Fieandt, Linus; Bednarcik, Jozef; Svedlindh, Peter; Gunnarsson, Klas; Sahlberg, Martin

2018-02-06

The low cost, rare earth free τ-phase of MnAl has high potential to partially replace bonded Nd 2 Fe 14 B rare earth permanent magnets. However, the τ-phase is metastable and it is experimentally difficult to obtain powders suitable for the permanent magnet alignment process, which requires the fine powders to have an appropriate microstructure and high τ-phase purity. In this work, a new method to make high purity τ-phase fine powders is presented. A high purity τ-phase Mn 0.55 Al 0.45 C 0.02 alloy was synthesized by the drop synthesis method. The drop synthesized material was subjected to cryo milling and  followed by a flash heating process. The crystal structure and microstructure of the drop synthesized, cryo milled and flash heated samples were studied by X-ray in situ powder diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy and electron backscatter diffraction. Magnetic properties and magnetic structure of the drop synthesized, cryo milled, flash heated  samples were characterized by magnetometry and neutron powder diffraction, respectively. The results reveal that the 2 and 4 hours cryo milled and flash heated samples both exhibit high τ-phase purity and micron-sized round particle shapes. Moreover, the flash heated samples display high saturation magnetization as well as increased coercivity.

Phase diagram of the relaxor ferroelectric (1- x )Pb(Mg 1/3Nb 2/3)O 3+ x PbTiO 3 revisited: a neutron powder diffraction study of the relaxor skin effect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phelan, D.; Rodriguez, E. E.; Gao, J.

2014-11-17

We revisit the phase diagram of the relaxor ferroelectric PMN- xPT using neutron powder diffraction to test suggestions that residual oxygen vacancies and/or strain affect the ground state crystal structure. Powdered samples of PMN- xPT were prepared with nominal compositions of x = 0:10, 0.20, 0.30, and 0.40 and divided into two identical sets, one of which was annealed in air to relieve grinding-induced strain and to promote an ideal oxygen stoichiometry. For a given composition and temperature the same structural phase is observed for each specimen. However, the distortions in all of the annealed samples are smaller than thosemore » in the as-grown samples. Further, the diffraction patterns for x = 0:10, 0.20, and 0.30 are best refined using the monoclinic Cm space group. By comparing our neutron diffraction results to those obtained on single crystals having similar compositions, we conclude that the relaxor skin effect in PMN- xPT vanishes on the Ti-rich side of the morphotropic phase boundary.« less

Hydrogenation properties of Li{sub x}Sr{sub 1−x}AlSi studied by quantum-chemical methods (0≤x≤1) and in-situ neutron powder diffraction (x=1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kunkel, Nathalie, E-mail: nathalie.kunkel@chimie-paristech.fr; FR 8.1 Universität des Saarlandes, Postach 151150, 66041 Saarbrücken; Reichert, Christian

2015-01-15

In-situ neutron powder diffraction studies of the Half-Heusler phase LiAlSi under high deuterium pressures and first principle calculations of solid solutions of Li{sub x}Sr{sub 1−x}AlSi and their hydrides Li{sub x}Sr{sub 1−x}AlSiH were carried out. In contrast to an earlier study, there is no experimental evidence for hydrogen (deuterium) uptake up to gas pressures of 15 MPa and temperatures of 550 °C. Instead a slow decomposition reaction according to LiAlSi+1/2H{sub 2}=LiH+Al+Si was found by in-situ neutron powder diffraction. Theoretical calculations by DFT methods on hypothetical solid solutions of Li{sub x}Sr{sub 1−x}AlSi show the LiAlSi type to be the energetically most stablemore » structure for 0.7« less

Characterization of Metal Powders Used for Additive Manufacturing.

PubMed

Slotwinski, J A; Garboczi, E J; Stutzman, P E; Ferraris, C F; Watson, S S; Peltz, M A

2014-01-01

Additive manufacturing (AM) techniques can produce complex, high-value metal parts, with potential applications as critical parts, such as those found in aerospace components. The production of AM parts with consistent and predictable properties requires input materials (e.g., metal powders) with known and repeatable characteristics, which in turn requires standardized measurement methods for powder properties. First, based on our previous work, we assess the applicability of current standardized methods for powder characterization for metal AM powders. Then we present the results of systematic studies carried out on two different powder materials used for additive manufacturing: stainless steel and cobalt-chrome. The characterization of these powders is important in NIST efforts to develop appropriate measurements and standards for additive materials and to document the property of powders used in a NIST-led additive manufacturing material round robin. An extensive array of characterization techniques was applied to these two powders, in both virgin and recycled states. The physical techniques included laser diffraction particle size analysis, X-ray computed tomography for size and shape analysis, and optical and scanning electron microscopy. Techniques sensitive to structure and chemistry, including X-ray diffraction, energy dispersive analytical X-ray analysis using the X-rays generated during scanning electron microscopy, and X-Ray photoelectron spectroscopy were also employed. The results of these analyses show how virgin powder changes after being exposed to and recycled from one or more Direct Metal Laser Sintering (DMLS) additive manufacturing build cycles. In addition, these findings can give insight into the actual additive manufacturing process.

A novel contrast agent with rare earth-doped up-conversion luminescence and Gd-DTPA magnetic resonance properties

NASA Astrophysics Data System (ADS)

Lu, Qing; Wei, Daixu; Cheng, Jiejun; Xu, Jianrong; Zhu, Jun

2012-08-01

The magnetic-luminescent multifunctional nanoparticles based on Gd-DTPA and NaYF4:Yb, Er were successfully synthesized by the conjugation of activated DTPA and silica-coated/surface-aminolated NaYF4:Yb, Er nanoparticles through EDC/NHS coupling chemistry. The as-prepared products were characterized by powder X-ray diffraction, transmission electron microscopy, dynamic light scattering, energy dispersive X-ray analysis, and fourier transform infrared spectrometry. The room-temperature upconversion luminescent spectra and T1-weighted maps of the obtained nanoparticles were carried out by 980 nm NIR light excitation and a 3T MR imaging scanner, respectively. The results indicated that the as-synthesized multifunctional nanoparticles with small size, highly solubility in water, and both high MR relaxivities and upconversion luminescence may have potential usage for MR imaging in future.

A study of the phase transition behaviour of [(NH4)0.63Li0.37]2TeBr6

NASA Astrophysics Data System (ADS)

Karray, R.; Linda, D.; Van Der Lee, A.; Ben Salah, A.; Kabadou, A.

2012-02-01

The mixed hexabromotellurate [(NH4)0.63Li0.37]2TeBr6, presenting at room temperature a K2PtCl6-type structure with space group Fm bar 3 m, exhibits three anomalies at 195, 395 and 498 K in the differential scanning calorimetry diagram. Different techniques: dielectric investigation, High-temperature X-ray powder diffraction and infrared spectroscopic study, in the range temperature (300-470) K are applied to explore the phase transition around 395 K. Combining XRD, dielectric and differential scanning calorimetry (DSC) results, no phase transition leading to a super-ionic conductivity phase is found. At high temperature, [(NH4)0.63Li0.37]2TeBr6 is characterized by a medium conductivity σ453≈ 10-4 Ω-1m-1.

Synthesis and physicochemical characterizations and antimicrobial activity of ZnO nanoparticles

NASA Astrophysics Data System (ADS)

Sharma, Bhumika K.; Patel, Kinjal; Roy, Debesh R.

2018-05-01

Nanoparticles exhibit very interesting and useful physicochemical properties when they interact with substrates and goes through some physicochemical and/or biological processes. ZnO is known to be a highly demanding nanomaterial due to its discreet properties, shapes and sizes. A detail experimental study on the synthesis, characterization and antibacterial activity of ZnO nanoparticles (NPs) is performed. ZnO NPs are synthesized using chemical precipitation method. The understanding of crystal structure, morphology and elemental compositions are explained using Powder X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FE-SEM) respectively. Fourier transform infrared spectroscopy (FTIR) is performed to achieve the information on the presence of various functional groups. The antibacterial activity of these ZnO NPs is investigated in terms of Zone of Inhibition (ZOI) against Escherichia coli (Gram negative) microorganisms.

Fabrication of malachite with a hierarchical sphere-like architecture.

PubMed

Xu, Jiasheng; Xue, Dongfeng

2005-09-15

Malachite (Cu2(OH)2CO3) with a hierarchical sphere-like architecture has been successfully synthesized via a simple and mild hydrothermal route in the absence of any external inorganic additives or organic structure-directing templates. Powder X-ray diffraction, scanning electron microscopy, and Fourier transmission infrared spectrometry are used to characterize various properties of the obtained malachite samples. The hierarchical malachite particles are uniform spheres with a diameter of 10-20 microm, which are comprised of numerous two-dimensional microplatelets paralleling the sphere surface. The initial concentration of reagents, the hydrothermal reaction time, and temperature are important factors which dominantly affect the evolution of crystal morphologies. The growth of the hierarchical architecture is believed to be a layer-by-layer growth process. Further, copper oxide with the similar morphology can be easily obtained from the as-prepared malachite.

Synthesis and characterization of α-cobalt hydroxide nanobelts

NASA Astrophysics Data System (ADS)

Tian, L.; Zhu, J. L.; Chen, L.; An, B.; Liu, Q. Q.; Huang, K. L.

2011-08-01

α-Cobalt hydroxide was synthesized by a facile hydrothermal process from Co(Ac)2 and NH3·H2O in the presence of 1,3-propanediol. The large-scale-prepared cobalt hydroxide has a uniform nanobelt morphology with a considerably high aspect-ratio more than 20 which may be advantageous for exploration of their physicochemical properties. This synthetic method is convenient, economical, and controllable. The samples were characterized by powder X-ray diffraction, energy dispersive spectrum, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, CHN element analysis, thermogravimetric and differential-thermogravimetric analysis, which revealed the compound is lamellar structural cobalt organic-inorganic hybrid with the chemical formula of Co(OH)1.49(NH3)0.01(CO3 2-)0.22(Ac-)0.07(H2O)0.11 and single-crystalline.

Synthesis and spectroscopic characterization of gold nanobipyramids prepared by a chemical reduction method

NASA Astrophysics Data System (ADS)

Thanh Ngo, Vo Ke; Phat Huynh, Trong; Giang Nguyen, Dang; Phuong Uyen Nguyen, Hoang; Lam, Quang Vinh; Dat Huynh, Thanh

2015-12-01

Gold nanobipyramids (NBPs) have attracted much attention because they have potential for applications in smart sensing devices, such as medical diagnostic equippments. This is due to the fact that they show more advantageous plasmonic properties than other gold nanostructures. We describe a chemical reduction method for synthesizing NBPs using conventional heating with ascorbic acid reduction and cetyltrimethylamonium bromide (CTAB) + AgNO3 as capping agents. The product was characterized by ultraviolet-visible spectroscopy (UV-vis), Fourier transmission infrared spectroscopy (FTIR), transmission electron microscopy (TEM), x-ray powder diffraction (XRD). The results showed that gold nanoparticles were formed with bipyramid shape (tip-to-tip distance of 88.4 ± 9.4 nm and base length of 29.9 ± 3.2 nm) and face-centered-cubic crystalline structure. Optimum parameters for preparation of NBPs are also found.

Defect-Induced Luminescence of a Self-Activated Borophosphate Phosphor

NASA Astrophysics Data System (ADS)

Han, Bing; Liu, Beibei; Dai, Yazhou; Zhang, Jie

2018-05-01

A self-activated borophosphate phosphor Ba3BPO7 was prepared via typical solid-state reaction in thermal-carbon reduction atmosphere. The structural and luminescence properties were investigated using x-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and photoluminescence spectroscopy. Upon excitation with ultraviolet (UV) light, the as-prepared phosphor shows bright greenish-yellow emission with a microsecond-level fluorescence lifetime, which could result from the oxygen vacancies produced in the process of solid-state synthesis. The possible luminescence mechanism is proposed. Through the introduction of defects in the host, this work realizes visible luminescence in a pure borophosphate compound that does not contain any rare earth or transition metal activators, so it is helpful to develop defect-related luminescent materials in view of energy conservation and environmental protection for sustainable development.

Hybrid magnetic materials formed by ferritin intercalated into a layered double hydroxide

NASA Astrophysics Data System (ADS)

Clemente-León, Miguel; Coronado, Eugenio; Primo, Vicent; Ribera, Antonio; Soriano-Portillo, Alejandra

2008-12-01

A hybrid magnetic material formed by ferritin intercalated into a layered double hydroxide (LDH) of Mg and Al (Mg/Al molar ratio 2) is prepared and characterized through powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, electron probe microanalysis (EPMA) and high resolution transmission electron microscopy (HRTEM). One observes an enhancement in the thermal stability of the ferritin molecules when they are inserted in the layered material. Magnetic measurements of the hybrid material exhibit the typical superparamagnetic behaviour of the ferritin molecule. On the other hand, the intercalation of ferritin into the LDH guarantees a homogeneous dispersion of the ferritin molecules, which do not aggregate even after calcination of the sample. This feature allows obtaining well-dispersed magnetic metal oxide nanoparticles upon calcination of the hybrid material.

Immobilization of Chlorosulfonyl-Calix[4]arene onto the surface of silica gel through the directly estrification

NASA Astrophysics Data System (ADS)

Taghvaei-Ganjali, Saeed; Zadmard, Reza; Saber-Tehrani, Mandana

2012-06-01

For the first time Chlorosulfonyl-Calix[4]arene has been chemically bonded to silica gel through the directly estrification without silane coupling agent to prepare Chlorosulfonyl-Calix[4]arene-bonded silica gel. Sample characterization was performed by various techniques such as elemental analysis, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), powder X-ray diffraction (XRD), N2 adsorption-desorption, thermal gravimetric analysis (TGA), 29Si CP/MAS spectroscopy and acid-base titration. All data approve the successful incorporation of organic group via covalent bond. From the comparison between sulfur content determined by elemental analysis and the number of H+ determined by acid-base titration, it was shown that two ester units took place onto the new synthesized sample and two acidic sites exist on the surface.

A Novel Method for Preparation of Gold NanoBipyramids Using Microwave Irradiation and Its Application in Immunosensors

NASA Astrophysics Data System (ADS)

Huynh, Trong Phat; Ngo, Vo Ke Thanh; Nguyen, Dang Giang; Nguyen, Hoang Phuong Uyen; Nghiem, Quoc Dat; Lam, Quang Vinh; Huynh, Thanh Dat

2016-05-01

Gold nanobipyramids (NBPs) have attracted attention for producing smart sensing devices as diagnostic tools in biotechnological and medical applications, because they show more advantageous plasmonic properties than comparable gold nanorods. Normally, NBPs were synthesized using seed-mediated growth process at room temperature. In this report, our group describes a method for synthesising of NBPs using microwave irradiation with ascorbic acid reduction and cetyltrimethylammonium bromide + silver nitrate (AgNO3) as capping agents. The advantages of this method are a highly effective approach to fast and uniform NBPs. The product was characterized by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and x-ray powder diffraction. As an application in quartz crystal microbalance immunosensors, NBPs is conjugated with the chloramphenicol antibodies for signal amplification to detect chloramphenicol residuals in the QCM system.

Intercalation of anionic organic ultraviolet ray absorbers into layered zinc hydroxide nitrate.

PubMed

Cursino, Ana Cristina Trindade; Gardolinski, José Eduardo Ferreira da Costa; Wypych, Fernando

2010-07-01

Layered zinc hydroxide nitrate (ZHN) was synthesized and nitrate ions were topotactically exchanged with three different anionic species of commercial organic ultraviolet (UV) ray absorbers: 2-mercaptobenzoic acid, 2-aminobenzoic acid, and 4-aminobenzoic acid. The exchange reactions were confirmed by X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR), ultraviolet visible (UV-Vis) spectroscopy, and thermal analysis (thermogravimetry, TGA, and differential thermal analysis, DTA). In all the anionic exchanged products, evidence of grafting of the organic species onto the inorganic matrix was obtained. In general, after intercalation/grafting, the UV absorption ability was improved in relation to the use of the parent organic material, showing that layered hydroxide salts (LHS) can be good alternative matrixes for the immobilization of organic species with UV-blocking properties in cosmetic products. Copyright 2010 Elsevier Inc. All rights reserved.

A structural investigation of a synthesized precursor for optical fiber applications; the heterobimetallic ErNb 2(OPr i) 13

NASA Astrophysics Data System (ADS)

Engholm, M.; Norin, L.; Edvardsson, S.; Lashgari, K.; Westin, G.

2006-12-01

A structural investigation of a synthesized precursor in a silica glass matrix is performed. Silica soot samples are doped with the heterobimetallic precursor ErNb 2(OPr i) 13 by using a conventional solution doping technique and heat treatments to different temperatures. The precursor has also been introduced into a silica fiber preform by using the modified chemical vapor deposition technique. Analyses are made by using ultraviolet-visible-near infrared absorption spectroscopy, scanning electron microscopy, energy dispersive spectroscopy and powder X-ray diffraction. It is concluded that an immiscible system of ErNbO 4 crystallites and Nb 2O 5 is formed in the silica soot samples at high temperatures. Colloidal particles of ErNbO 4 are also formed in the silica glass fiber preform showing interesting features.

Crystal structure of choline fenofibrate (Trilipix®), (C5H14NO) (C17H14ClO4)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaduk, James A.; Zhong, Kai; Gindhart, Amy M.

2016-04-04

The crystal structure of choline fenofibrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Choline fenofibrate crystallizes in space groupPbca(#61) witha= 12.341 03(2),b= 28.568 70(6),c= 12.025 62(2) Å,V= 4239.84(1) Å 3, andZ= 8. The hydroxyl group of the choline anion makes a strong hydrogen bond to the ionized carboxylate group of the fenofibrate anion. Together with C–H···O hydrogen bonds, these link the cations and anions into layers parallel to theac-plane. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.

Mechanical behaviour of pressed and sintered CP Ti and Ti-6Al-7Nb alloy obtained from master alloy addition powder.

PubMed

Bolzoni, L; Weissgaerber, T; Kieback, B; Ruiz-Navas, E M; Gordo, E

2013-04-01

The Ti-6Al-7Nb alloy was obtained using the blending elemental approach with a master alloy and elemental titanium powders. Both the elemental titanium and the Ti-6Al-7Nb powders were characterised using X-ray diffraction, differential thermal analysis and dilatometry. The powders were processed using the conventional powder metallurgy route that includes uniaxial pressing and sintering. The trend of the relative density with the sintering temperature and the microstructural evolution of the materials sintered at different temperatures were analysed using scanning electron microscopy and X-ray diffraction. A minimum sintering temperature of 1200°C has to be used to ensure the homogenisation of the alloying elements and to obtain a pore structure composed of spherical pores. The sintered samples achieve relative density values that are typical for powder metallurgy titanium and no intermetallic phases were detected. Mechanical properties comparable to those specified for wrought Ti-6Al-7Nb medical devices are normally obtained. Therefore, the produced materials are promising candidates for load bearing applications as implant materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bioactivity and cell proliferation in radiopaque gel-derived CaO-P2O5-SiO2-ZrO2 glass and glass-ceramic powders.

PubMed

Montazerian, Maziar; Yekta, Bijan Eftekhari; Marghussian, Vahak Kaspari; Bellani, Caroline Faria; Siqueira, Renato Luiz; Zanotto, Edgar Dutra

2015-10-01

In this study, 10 mol% ZrO2 was added to a 27CaO-5P2O5-68SiO2 (mol%) base composition synthesized via a simple sol-gel method. This composition is similar to that of a frequently investigated bioactive gel-glass. The effects of ZrO2 on the in vitro bioactivity and MG-63 cell proliferation of the glass and its derivative polycrystalline (glass-ceramic) powder were investigated. The samples were characterized using thermo-gravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) coupled to energy dispersive X-ray spectroscopy (EDS). Release of Si, Ca, P and Zr into simulated body fluid (SBF) was determined by inductively coupled plasma (ICP). Upon heat treatment at 1000 °C, the glass powder crystallized into an apatite-wollastonite-zirconia glass-ceramic powder. Hydroxycarbonate apatite (HCA) formation on the surface of the glass and glass-ceramic particles containing ZrO2 was confirmed by FTIR and SEM. Addition of ZrO2 to the base glass composition decreased the rate of HCA formation in vitro from one day to three days, and hence, ZrO2 could be employed to control the rate of apatite formation. However, the rate of HCA formation on the glass-ceramic powder containing ZrO2 crystal was equal to that in the base glassy powder. Tests with a cultured human osteoblast-like MG-63 cells revealed that the glass and glass-ceramic materials stimulated cell proliferation, indicating that they are biocompatible and are not cytotoxic in vitro. Moreover, zirconia clearly increased osteoblast proliferation over that of the Zr-free samples. This increase is likely associated with the lower solubility of these samples and, consequently, a smaller variation in the media pH. Despite the low solubility of these materials, bioactivity was maintained, indicating that these glassy and polycrystalline powders are potential candidates for bone graft substitutes and bone cements with the special feature of radiopacity. Copyright © 2015 Elsevier B.V. All rights reserved.

Design, physicochemical characterization, and optimization of organic solution advanced spray-dried inhalable dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine poly(ethylene glycol) (DPPE-PEG) microparticles and nanoparticles for targeted respiratory nanomedicine delivery as dry powder inhalation aerosols

PubMed Central

Meenach, Samantha A; Vogt, Frederick G; Anderson, Kimberly W; Hilt, J Zach; McGarry, Ronald C; Mansour, Heidi M

2013-01-01

Novel advanced spray-dried and co-spray-dried inhalable lung surfactant-mimic phospholipid and poly(ethylene glycol) (PEG)ylated lipopolymers as microparticulate/nanoparticulate dry powders of biodegradable biocompatible lipopolymers were rationally formulated via an organic solution advanced spray-drying process in closed mode using various phospholipid formulations and rationally chosen spray-drying pump rates. Ratios of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine PEG (DPPE-PEG) with varying PEG lengths were mixed in a dilute methanol solution. Scanning electron microscopy images showed the smooth, spherical particle morphology of the inhalable particles. The size of the particles was statistically analyzed using the scanning electron micrographs and SigmaScan® software and were determined to be 600 nm to 1.2 μm in diameter, which is optimal for deep-lung alveolar penetration. Differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) were performed to analyze solid-state transitions and long-range molecular order, respectively, and allowed for the confirmation of the presence of phospholipid bilayers in the solid state of the particles. The residual water content of the particles was very low, as quantified analytically via Karl Fischer titration. The composition of the particles was confirmed using attenuated total-reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy and confocal Raman microscopy (CRM), and chemical imaging confirmed the chemical homogeneity of the particles. The dry powder aerosol dispersion properties were evaluated using the Next Generation Impactor™ (NGI™) coupled with the HandiHaler® dry powder inhaler device, where the mass median aerodynamic diameter from 2.6 to 4.3 μm with excellent aerosol dispersion performance, as exemplified by high values of emitted dose, fine particle fraction, and respirable fraction. Overall, it was determined that the pump rates defined in the spray-drying process had a significant effect on the solid-state particle properties and that a higher pump rate produced the most optimal system. Advanced dry powder inhalers of inhalable lipopolymers for targeted dry powder inhalation delivery were successfully achieved. PMID:23355776

Synthesis of Amorphous Powders of Ni-Si and Co-Si Alloys by Mechanical Alloying

NASA Astrophysics Data System (ADS)

Omuro, Keisuke; Miura, Harumatsu

1991-05-01

Amorphous powders of the Ni-Si and Co-Si alloys are synthesized by mechanical alloying (MA) from crystalline elemental powders using a high energy ball mill. The alloying and amorphization process is examined by X-ray diffraction, differential scanning calorimetry (DSC), and scanning electron microscopy. For the Ni-Si alloy, it is confirmed that the crystallization temperature of the MA powder, measured by DSC, is in good agreement with that of the powder sample prepared by mechanical grinding from the cast alloy ingot products of the same composition.

Three-dimensional electron diffraction as a complementary technique to powder X-ray diffraction for phase identification and structure solution of powders.

PubMed

Yun, Yifeng; Zou, Xiaodong; Hovmöller, Sven; Wan, Wei

2015-03-01

Phase identification and structure determination are important and widely used techniques in chemistry, physics and materials science. Recently, two methods for automated three-dimensional electron diffraction (ED) data collection, namely automated diffraction tomography (ADT) and rotation electron diffraction (RED), have been developed. Compared with X-ray diffraction (XRD) and two-dimensional zonal ED, three-dimensional ED methods have many advantages in identifying phases and determining unknown structures. Almost complete three-dimensional ED data can be collected using the ADT and RED methods. Since each ED pattern is usually measured off the zone axes by three-dimensional ED methods, dynamic effects are much reduced compared with zonal ED patterns. Data collection is easy and fast, and can start at any arbitrary orientation of the crystal, which facilitates automation. Three-dimensional ED is a powerful technique for structure identification and structure solution from individual nano- or micron-sized particles, while powder X-ray diffraction (PXRD) provides information from all phases present in a sample. ED suffers from dynamic scattering, while PXRD data are kinematic. Three-dimensional ED methods and PXRD are complementary and their combinations are promising for studying multiphase samples and complicated crystal structures. Here, two three-dimensional ED methods, ADT and RED, are described. Examples are given of combinations of three-dimensional ED methods and PXRD for phase identification and structure determination over a large number of different materials, from Ni-Se-O-Cl crystals, zeolites, germanates, metal-organic frameworks and organic compounds to intermetallics with modulated structures. It is shown that three-dimensional ED is now as feasible as X-ray diffraction for phase identification and structure solution, but still needs further development in order to be as accurate as X-ray diffraction. It is expected that three-dimensional ED methods will become crucially important in the near future.

High Pressure X-Ray Diffraction Studies of Nanocrystalline Materials

NASA Technical Reports Server (NTRS)

Palosz, B.; Stel'makh, S.; Grzanka, E.; Gierlotka, S.; Palosz, W.

2004-01-01

Experimental evidence obtained for a variety of nanocrystalline materials suggest that the crystallographic structure of a very small size particle deviates from that in the bulk crystals. In this paper we show the effect of the surface of nanocrystals on their structure by the analysis of generation and distribution of macro- and micro-strains at high pressures and their dependence on the grain size in nanocrystalline powders of Sic. We studied the structure of Sic nanocrystals by in-situ high-pressure powder diffraction technique using synchrotron and neutron sources and hydrostatic or isostatic pressure conditions. The diffraction measurements were done in HASYLAB at DESY using a Diamond Anvil Cell (DAC) in the energy dispersive geometry in the diffraction vector range up to 3.5 - 4/A and under pressures up to 50 GPa at room temperature. In-situ high pressure neutron diffraction measurements were done at LANSCE in Los Alamos National Laboratory using the HIPD and HIPPO diffractometers with the Paris-Edinburgh and TAP-98 cells, respectively, in the diffraction vector range up to 26 Examination of the response of the material to external stresses requires nonstandard methodology of the materials characterization and description. Although every diffraction pattern contains a complete information on macro- and micro-strains, a high pressure experiment can reveal only those factors which contribute to the characteristic diffraction patterns of the crystalline phases present in the sample. The elastic properties of powders with the grain size from several nm to micrometers were examined using three methodologies: (l), the analysis of positions and widths of individual Bragg reflections (used for calculating macro- and micro-strains generated during densification) [I], (2). the analysis of the dependence of the experimental apparent lattice parameter, alp, on the diffraction vector Q [2], and (3), the atomic Pair Distribution Function (PDF) technique [3]. The results of our studies show, that Sic nanocrystals have the features of two phases, each with its distinct elastic properties. and under pressures up to 8 GPa.

A Comparison of Cocrystal Structure Solutions from Powder and Single Crystal Techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

S Lapidus; P Stephens; K Arora

We demonstrate the effectiveness and accuracy of high resolution powder diffraction for determination of cocrystal structures through a double-blind study. Structures of 10 cocrystals of varying complexity were determined independently using single crystal and powder techniques. The two methodologies give identical molecular packing and hydrogen bond topology, and an rms difference in covalent bond lengths of 0.035 {angstrom}. Powder techniques are clearly sufficient to establish a complete characterization of cocrystal geometry.

Heat-Stable Dry Powder Oxytocin Formulations for Delivery by Oral Inhalation.

PubMed

Fabio, Karine; Curley, Kieran; Guarneri, Joseph; Adamo, Benoit; Laurenzi, Brendan; Grant, Marshall; Offord, Robin; Kraft, Kelly; Leone-Bay, Andrea

2015-12-01

In this work, heat stable dry powders of oxytocin (OT) suitable for delivery by oral inhalation were prepared. The OT dry powders were prepared by spray drying using excipients chosen to promote OT stability including trehalose, isoleucine, polyvinylpyrrolidone, citrate (sodium citrate and citric acid), and zinc salts (zinc chloride and zinc citrate). Characterization by laser diffraction indicated that the OT dry powders had a median particle size of 2 μm, making them suitable for delivery by inhalation. Aerodynamic performance upon discharge from proprietary dry powder inhalers was evaluated by Andersen cascade impaction (ACI) and in an anatomically correct airway (ACA) model, and confirmed that the powders had excellent aerodynamic performance, with respirable fractions up to 77% (ACI, 30 L/min). Physicochemical characterization demonstrated that the powders were amorphous (X-ray diffraction) with high glass transition temperature (modulated differential scanning calorimetry, MDSC), suggesting the potential for stabilization of the OT in a glassy amorphous matrix. OT assay and impurity profile were conducted by reverse phase HPLC and liquid chromatography-mass spectrometry (LC-MS) after storage up to 32 weeks at 40°C/75%RH. Analysis demonstrated that OT dry powders containing a mixture of citrate and zinc salts retained more than 90% of initial assay after 32 weeks storage and showed significant reduction in dimers and trisulfide formation (up to threefold reduction compared to control).

X-ray investigations related to the shock history of the Shergotty achondrite

NASA Technical Reports Server (NTRS)

Horz, F.; Hanss, R.; Serna, C.

1986-01-01

The shock stress suffered by naturally shocked materials from the Shergotty achondrite was studied using X-ray diffraction techniques and experimentally shocked augite and enstatite as standards. The Shergotty pyroxenes revealed the formation of continuous diffraction rings, line broadening, preferred orientation of small scale diffraction domains, and other evidence of substantial lattice disorders. As disclosed by the application of Debye-Scherrer techniques, they are hybrids between single crystals and fine-grained random powders. The pyroxene lattice is very resistant to shock damage on smaller scales. While measurable lattice disaggregation and progressive fragmentation occur below 25 GPa, little additional damage is suffered from application of pressures between 30 to 60 GPa, making pressure calibration of naturally shocked pyroxenes via X-ray methods difficult. Powder diffractometer scans on pure maskelynite fractions of Shergotty revealed small amounts of still coherently diffracting plagioclase, which may contribute to the high refractive indices of the diaplectic feldspar glasses of Shergotty.

Examination of Short- and Long-Range Atomic Order Nanocrystalline SiC and Diamond by Powder Diffraction Methods

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Stelmakh, S.; Gierlotka, S.; Weber, H.-P.; Proffen, T.; Palosz, W.

2002-01-01

The real atomic structure of nanocrystals determines unique, key properties of the materials. Determination of the structure presents a challenge due to inherent limitations of standard powder diffraction techniques when applied to nanocrystals. Alternate methodology of the structural analysis of nanocrystals (several nanometers in size) based on Bragg-like scattering and called the "apparent lattice parameter" (alp) is proposed. Application of the alp methodology to examination of the core-shell model of nanocrystals will be presented. The results of application of the alp method to structural analysis of several nanopowders were complemented by those obtained by determination of the Atomic Pair Distribution Function, PDF. Based on synchrotron and neutron diffraction data measured in a large diffraction vector of up to Q = 25 Angstroms(exp -1), the surface stresses in nanocrystalline diamond and SiC were evaluated.

Valence fluctuating compound α-YbAlB4 studied by 174Yb Mössbauer spectroscopy and X-ray diffraction using synchrotron radiation

NASA Astrophysics Data System (ADS)

Oura, Momoko; Ikeda, Shugo; Masuda, Ryo; Kobayashi, Yasuhiro; Seto, Makoto; Yoda, Yoshitaka; Hirao, Naohisa; Kawaguchi, Saori I.; Ohishi, Yasuo; Suzuki, Shintaro; Kuga, Kentaro; Nakatsuji, Satoru; Kobayashi, Hisao

2018-05-01

The structural properties and the Yb 4 f electronic state of the valence fluctuating α-YbAlB4 have been investigated by powder X-ray diffraction under pressure and 174Yb Mössbauer spectroscopy with magnetic fields at low temperature, respectively, using synchrotron radiation. Powder X-ray diffraction patterns showed that the crystal structure does not change up to p ∼ 18 GPa at 8 K and the volume decreases smoothly. However, the pressure dependence of the difference in the structure factor between the (060) and (061) diffraction lines changes at ∼ 3.4 GPa, indicating the change of atomic coordination parameters. The 174Yb Mössbauer spectroscopy measurements at 2 K with 10 and 50 kOe suggest that the electrical quadrupole interaction changes by applied magnetic fields.

XRD and FTIR structural investigation of gadolinium-zinc-borate glass ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borodi, G.; Pascuta, P.; Dan, V.

2013-11-13

X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy measurements have been employed to investigate the (Gd{sub 2}O{sub 3}){sub x}⋅(B{sub 2}O{sub 3}){sub (60−x)}⋅(ZnO){sub 40} glass ceramics system, with 0 ≤ x ≤ 15 mol%. After heat treatment applied at 860 °C for 2 h, some structural changes were observed and new crystalline phases appeared in the structure of the samples. In these glass ceramics four crystalline phases were identified using powder diffraction files (PDF 2), namely ZnB{sub 4}O{sub 7}, Zn{sub 4}O(B{sub 6}O{sub 12}), Zn{sub 3}(BO{sub 3}){sub 2} and GdBO{sub 3}. From the XRD data, the average unit-cell parameter and themore » quantitative ratio of the crystallographic phases in the studied samples were evaluated. FTIR data revealed that the BO{sub 3}, BO{sub 4} and ZnO{sub 4} are the main structural units of these glass ceramics network. The compositional dependence of the different structural units which appear in the studied samples was followed.« less

Microwave-assisted hydrothermal synthesis of biocompatible silver sulfide nanoworms

NASA Astrophysics Data System (ADS)

Xing, Ruimin; Liu, Shanhu; Tian, Shufang

2011-10-01

In this study, silver sulfide nanoworms were prepared via a rapid microwave-assisted hydrothermal method by reacting silver nitrate and thioacetamide in the aqueous solution of the Bovine Serum Albumin (BSA) protein. The morphology, composition, and crystallinity of the nanoworms were characterized by field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray energy dispersive spectroscopy (EDS), and Fourier transform infrared (FTIR) spectroscopy. The results show that the nanoworms were assembled by multiple adjacent Ag2S nanoparticles and stabilized by a layer of BSA attached to their surface. The nanoworms have the sizes of about 50 nm in diameter and hundreds of nanometers in length. The analyses of high-resolution TEM and their correlative Fast Fourier Transform (FFT) indicate that the adjacent Ag2S nanoparticles grow by misoriented attachment at the connective interfaces to form the nanoworm structure. In vitro assays on the human cervical cancer cell line HeLa show that the nanoworms exhibit good biocompatibility due to the presence of BSA coating. This combination of features makes the nanoworms attractive and promising building blocks for advanced materials and devices.

Different water clusters dependent on long-chain dicarboxylates in two Ag(I) coordination polymers: Synthesis, structure and thermal stability

NASA Astrophysics Data System (ADS)

Sun, Di; Liu, Fu-Jing; Hao, Hong-Jun; Huang, Rong-Bin; Zheng, Lan-Sun

2011-10-01

Two mixed-ligand Ag(I) coordination polymers (CPs), [Ag 2(bipy) 2(sub)·5H 2O] n ( 1), [Ag 2(bipy) 2(aze)·3H 2O] n ( 2), (bipy = 4,4'-bipyridine, H 2sub = suberic acid, H 2aze = azelaic acid) have been synthesized and structurally characterized by elemental analysis, infrared (IR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric (TG) analysis, and single crystal X-ray diffraction. Both 1 and 2 are two-dimensional (2D) sheets based on infinite [Ag(bipy)] n double chain incorporating Ag⋯Ag interactions. Interestingly, two different water clusters are encapsulated in the voids between the sheets of 1 and 2. For 1, one water decamer (H 2O) 10 based on a cyclic water tetramer was hydrogen-bonded with the host 2D sheet. While, one water hexamer (H 2O) 6 also based on a cyclic water tetramer was observed in 2. Comparing the experimental results, it is comprehensible that the dicarboxylates play a crucial role in the formation of the different water clusters. Moreover, the thermal stabilities of them were also discussed.

Utilization of oriented crystal growth for screening of aromatic carboxylic acids cocrystallization with urea

NASA Astrophysics Data System (ADS)

Przybyłek, Maciej; Ziółkowska, Dorota; Kobierski, Mirosław; Mroczyńska, Karina; Cysewski, Piotr

2016-01-01

The possibility of molecular complex formation in the solid state of urea with benzoic acid analogues was measured directly on the crystallite films deposited on the glass surface using powder X-ray diffractometry (PXRD). Obtained solid mixtures were also analyzed using Fourier transform infrared spectroscopy (FTIR). The simple droplet evaporation method was found to be efficient, robust, fast and cost-preserving approach for first stage cocrystal screening. Additionally, the application of orientation effect to cocrystal screening simplifies the analysis due to damping of majority of diffraction signals coming from coformers. During validation phase the proposed approach successfully reproduced both positive cases of cocrystallization (urea:salicylic acid and urea:4-hydroxy benzoic acid) as well as pairs of co-formers immiscible in the solid state (urea:benzoic acid and urea:acetylsalicylic acids). Based on validated approach new cocrystals of urea were identified in complexes with 3-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid and 3,5-dihydroxybenzoic acid. In all cases formation of multicomponent crystal phase was confirmed by the appearance of new reflexes on the diffraction patterns and FTIR absorption band shifts of O-H and N-H groups.

The effect of chemical modification on the physico-chemical characteristics of halloysite: FTIR, XRF, and XRD studies

NASA Astrophysics Data System (ADS)

Szczepanik, Beata; Słomkiewicz, Piotr; Garnuszek, Magdalena; Czech, Kamil; Banaś, Dariusz; Kubala-Kukuś, Aldona; Stabrawa, Ilona

2015-03-01

The effect of chemical modification of halloysite from a Polish strip mine "Dunino" on the chemical composition and structure of this clay mineral was studied using infrared spectroscopy (ATR FT-IR), wavelength dispersive X-ray fluorescence (WDXRF), and X-ray powder diffraction (XRPD) methods. The results obtained by the WDXRF technique confirm that the content of silica and alumina was the highest for bleached halloysite samples and the lowest for acid-treated halloysite. A higher content of Fe2O3 in comparison to halloysite samples coming from other countries was observed for raw halloysite samples. XRPD diffraction pattern obtained for raw halloysite confirmed the presence of halloysite, kaolinite, hematite, and calcite minerals in the sample. Bleaching the halloysite removes (or significantly reduces) the content of other minerals present in the raw halloysite. The FT-IR spectra of the studied halloysite samples show in the 3700-3600 cm-1 region well-defined hydroxyl stretching bands characteristic for the kaolin-group minerals and bands associated with the vibrations of the aluminium-silicon skeleton in the 1400-1000 cm-1 region. Modifying halloysite with 4-chloro-aniline causes successive incorporation of amine into the BH sample.

Ag/CuO nanoparticles prepared from a novel trinuclear compound [Cu(Imdz)4(Ag(CN)2)2] (Imdz = imidazole) by a pyrolysis display excellent antimicrobial activity

NASA Astrophysics Data System (ADS)

Adhikary, Jaydeep; Das, Balaram; Chatterjee, Sourav; Dash, Sandeep Kumar; Chattopadhyay, Sourav; Roy, Somenath; Chen, Jeng-Wei; Chattopadhyay, Tanmay

2016-06-01

One copper and two silver containing one hetero tri-nuclear precursor compound [Cu(Imdz)4(Ag(CN)2)2] (1) (Imdz = Imidazole) has been synthesized and characterized by single crystal X-ray diffraction. Simple pyrolysis of the complex at 550 °C for 4 h afforded Ag/CuO nanoparticles (NPs). The synthesized nanoparticles were characterized by ultraviolet-visible (UV-Vis), Fourier transform infrared (FT-IR), X-ray powder diffraction (XRPD), dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and X-ray photo electron spectroscopy (XPS). Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) have been employed as model microbial species to study the anti-microbial activity of the synthesized NPs. The NPs showed potent anti-microbial activity evidenced from the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values. Very high level of cell uptake and then generation of reactive oxygen species (ROS) are the origin of such strong antimicrobial activity for the NPs. However, the cytotoxicity level of the NPs towards normal human cell is very low.

X-ray diffraction, vibrational and quantum chemical investigations of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid

NASA Astrophysics Data System (ADS)

Arjunan, V.; Marchewka, Mariusz K.; Pietraszko, A.; Kalaivani, M.

2012-11-01

The structural investigations of the molecular complex of 2-methyl-4-nitroaniline with trichloroacetic acid, namely 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid (C11H10Cl6N2O6) have been performed by means of single crystal and powder X-ray diffraction method. The complex was formed with accompanying proton transfer from trichloroacetic acid molecule to 2-methyl-4-nitroaniline. The studied crystal is built up of singly protonated 2-methyl-4-nitroanilinium cations, trichloroacetate anions and neutral trichloroacetic acid molecules. The crystals are monoclinic, space group P21/c, with a = 14.947 Å, b = 6.432 Å, c = 19.609 Å and Z = 4. The vibrational assignments and analysis of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid have also been performed by FTIR, FT-Raman and far-infrared spectral studies. More support on the experimental findings were added from the quantum chemical studies performed with DFT (B3LYP) method using 6-31G**, cc-pVDZ, 6-31G and 6-31++G basis sets. The structural parameters, energies, thermodynamic parameters and the NBO charges of 2M4NATCA were also determined by the DFT methods.

New synchrotron powder diffraction facility for long-duration experiments

PubMed Central

Murray, Claire A.; Potter, Jonathan; Day, Sarah J.; Baker, Annabelle R.; Thompson, Stephen P.; Kelly, Jon; Morris, Christopher G.; Tang, Chiu C.

2017-01-01

A new synchrotron X-ray powder diffraction instrument has been built and commissioned for long-duration experiments on beamline I11 at Diamond Light Source. The concept is unique, with design features to house multiple experiments running in parallel, in particular with specific stages for sample environments to study slow kinetic systems or processes. The instrument benefits from a high-brightness X-ray beam and a large area detector. Diffraction data from the commissioning work have shown that the objectives and criteria are met. Supported by two case studies, the results from months of measurements have demonstrated the viability of this large-scale instrument, which is the world’s first dedicated facility for long-term studies (weeks to years) using synchrotron radiation. PMID:28190992

Synthesis and Characterization of Single-Source Molecular Precursors to Binary Metal Sulphides: Bis(Diethyldithiocarbamato) M(II)Trialkylphosphine (M=Zn and Cd) Adducts

DTIC Science & Technology

1994-05-06

while the heterobimetallic species, 7, thermally decomposed to give00 crystalline ZnO.5S according to X-ray powder diffraction data. A. SUBJECT TERMS 15... heterobimetallic species, 7, thermally decomposed to give crystalline ZnO.5CdO.5S according to X-ray powder diffraction data. LaGOSSIOn "or OTIS RA&I VT-iC TAB EU...on the NMR timescale, and a single heterobimetallic species. Attempts to distinguish these possibilities are described later. The variable temperature

Synthesis and characterisation of composite based biohydroxyapatite bovine bone mandible waste (BHAp) doped with 10 wt % amorphous SiO{sub 2} from rice husk by solid state reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asmi, Dwi, E-mail: dwiasmi82@yahoo.com, E-mail: dwi.asmi@fmipa.unila.ac.id; Sulaiman, Ahmad, E-mail: ahmadsulaiman@yahoo.co.id; Oktavia, Irene Lucky, E-mail: ireneluckyo@gmail.com

Effect of 10 wt% amorphous SiO{sub 2} from rice husk addition on the microstructures of biohydroxyapatite (BHAp) obtained from bovine bone was synthesized by solid state reaction. In this study, biohydroxyapatite powder was obtained from bovine bone mandible waste heat treated at 800 °C for 5 h and amorphous SiO{sub 2} powder was extracted from citric acid leaching of rice husk followed by combustion at 700°C for 5 h. The composite powder then mixed and sintered at 1200 °C for 3 h. X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy and Scanning electron microscopy (SEM) techniques are utilized to characterize the phase relations,more » functional group present and morphology of the sample. The study has revealed that the processing procedures played an important role in microstructural development of BHAp-10 wt% SiO{sub 2} composite. The XRD study of the raw material revealed that the primary phase material in the heat treated of bovine bone mandible waste is hydroxyapatite and in the combustion of rice husk is amorphous SiO{sub 2}. However, in the composite the hydroxyapatite, β-tricalcium phosphate, and calcium phosphate silicate were observed. The FTIR result show that the hydroxyl stretching band in the composite decrease compared with those of hydroxyapatite spectra and the evolution of morphology was occurred in the composite.« less

X-ray diffraction and infrared spectroscopy analyses on the crystallinity of engineered biological hydroxyapatite for medical application

NASA Astrophysics Data System (ADS)

Poralan, G. M., Jr.; Gambe, J. E.; Alcantara, E. M.; Vequizo, R. M.

2015-06-01

Biological hydroxyapatite (BHAp) derived from thermally-treated fish bones was successfully produced. However, the obtained biological HAp was amorphous and thus making it unfavorable for medical application. Consequently, this research exploits and engineers the crystallinity of BHAp powders by addition of CaCO3 and investigates its degree of crystallinity using XRD and IR spectroscopy. On XRD, the HAp powders with [Ca]/[P] ratios 1.42, 1.46, 1.61 and 1.93 have degree of crystallinity equal to 58.08, 72.13, 85.79, 75.85% and crystal size equal to 0.67, 0.74, 0.75, 0.72 nm, respectively. The degree of crystallinity and crystal size of the obtained calcium deficient biological HAp powders increase as their [Ca]/[P] ratio approaches the stoichiometric ratio by addition of CaCO3 as source of Ca2+ ions. These results show the possibility of engineering the crystallinity and crystal size of biological HAp by addition of CaCO3. Moreover, the splitting factor of PO4 vibration matches the result with % crystallinity on XRD. Also, the area of phosphate-substitution site of PO4 vibration shows linear relationship (R2 = 0.994) with crystal size calculated from XRD. It is worth noting that the crystallinity of the biological HAp with [Ca]/[P] ratios 1.42 and 1.48 fall near the range 60-70% for highly resorbable HAp used in the medical application.

Synthesis and characterisation of composite based biohydroxyapatite bovine bone mandible waste (BHAp) doped with 10 wt % amorphous SiO2 from rice husk by solid state reaction

NASA Astrophysics Data System (ADS)

Asmi, Dwi; Sulaiman, Ahmad; Oktavia, Irene Lucky; Badaruddin, Muhammad; Zulfia, Anne

2016-04-01

Effect of 10 wt% amorphous SiO2 from rice husk addition on the microstructures of biohydroxyapatite (BHAp) obtained from bovine bone was synthesized by solid state reaction. In this study, biohydroxyapatite powder was obtained from bovine bone mandible waste heat treated at 800 °C for 5 h and amorphous SiO2 powder was extracted from citric acid leaching of rice husk followed by combustion at 700°C for 5 h. The composite powder then mixed and sintered at 1200 °C for 3 h. X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy and Scanning electron microscopy (SEM) techniques are utilized to characterize the phase relations, functional group present and morphology of the sample. The study has revealed that the processing procedures played an important role in microstructural development of BHAp-10 wt% SiO2 composite. The XRD study of the raw material revealed that the primary phase material in the heat treated of bovine bone mandible waste is hydroxyapatite and in the combustion of rice husk is amorphous SiO2. However, in the composite the hydroxyapatite, β-tricalcium phosphate, and calcium phosphate silicate were observed. The FTIR result show that the hydroxyl stretching band in the composite decrease compared with those of hydroxyapatite spectra and the evolution of morphology was occurred in the composite.

Soapnut extract mediated synthesis of nanoscale cobalt substituted NdFeB ferromagnetic materials and their characterization

NASA Astrophysics Data System (ADS)

Rao, G. V. S. Jayapala; Prasad, T. N. V. K. V.; Shameer, Syed; Rao, M. Purnachandra

2018-04-01

Neodymium iron boron (NdFeB) permanent magnets have high energy product with suitable magnetic and physical properties for an array of applications including power generation and motors. However, synthetic routes of NdFeB permanent magnets involve critical procedures with high energy and needs scientific skills. Herein, we report on soapnut extract mediated synthesis of nanoscale cobalt substituted NdFeB (Co-NdFeB) permanent magnetic powders (Nd: 15%, Fe: 77.5%, B: 7.5% and Co with molar ratios: 0.5, 1, 1.5 and 2). A 10 ml of 10% soapnut extract was added to 90 ml of respective chemical composition and heated to 60 °C for 30 min and aged for 24 h. The dried powder was sintered at 500 °C for 1 h. The characterization of the prepared nanoscale Co-NdFeB magnetic powders was done using the techniques such as Dynamic Light Scattering (DLS for size and zeta potential measurements), X-ray diffraction (XRD) for structural determination, Scanning electron microscopy (SEM) with energy dispersion spectroscopy (EDS) for surface morphological and elemental analysis, Fourier transform infrared spectroscopy (FT-IR) for the identification of functional groups associated and hysteresis loop studies to quantify the magnetization. The results revealed that particles were in irregular and tubular shaped and highly stable (Zeta potential: -44.4 mV) with measured size <100 nm. XRD micrographs revealed a tetragonal crystal structure and FTIR showed predominant N-H and O-H stretching indicates the involvement of these functional groups in the reduction and stabilization process of Co-NdFeB magnetic powders. Hysteresis studies signify the effect of an increase in Co concentration.

Advanced Structural Analyses by Third Generation Synchrotron Radiation Powder Diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakata, M.; Aoyagi, S.; Ogura, T.

2007-01-19

Since the advent of the 3rd generation Synchrotron Radiation (SR) sources, such as SPring-8, the capabilities of SR powder diffraction increased greatly not only in an accurate structure refinement but also ab initio structure determination. In this study, advanced structural analyses by 3rd generation SR powder diffraction based on the Large Debye-Scherrer camera installed at BL02B2, SPring-8 is described. Because of high angular resolution and high counting statistics powder data collected at BL02B2, SPring-8, ab initio structure determination can cope with a molecular crystals with 65 atoms including H atoms. For the structure refinements, it is found that a kindmore » of Maximum Entropy Method in which several atoms are omitted in phase calculation become very important to refine structural details of fairy large molecule in a crystal. It should be emphasized that until the unknown structure is refined very precisely, the obtained structure by Genetic Algorithm (GA) or some other ab initio structure determination method using real space structural knowledge, it is not possible to tell whether the structure obtained by the method is correct or not. In order to determine and/or refine crystal structure of rather complicated molecules, we cannot overemphasize the importance of the 3rd generation SR sources.« less

Investigation of the Surface Stress in SiC and Diamond Nanocrystals by In-situ High Pressure Powder Diffraction Technique

NASA Technical Reports Server (NTRS)

Palosz, B.; Stelmakh, S.; Grzanka, E.; Gierlotka, S.; Zhao, Y.; Palosz, W.

2003-01-01

The real atomic structure of nanocrystals determines key properties of the materials. For such materials the serious experimental problem lies in obtaining sufficiently accurate measurements of the structural parameters of the crystals, since very small crystals constitute rather a two-phase than a uniform crystallographic phase system. As a result, elastic properties of nanograins may be expected to reflect a dual nature of their structure, with a corresponding set of different elastic property parameters. We studied those properties by in-situ high-pressure powder diffraction technique. For nanocrystalline, even one-phase materials such measurements are particularly difficult to make since determination of the lattice parameters of very small crystals presents a challenge due to inherent limitations of standard elaboration of powder diffractograms. In this investigation we used our methodology of the structural analysis, the 'apparent lattice parameter' (alp) concept. The methodology allowed us to avoid the traps (if applied to nanocrystals) of standard powder diffraction evaluation techniques. The experiments were performed for nanocrystalline Sic and GaN powders using synchrotron sources. We applied both hydrostatic and isostatic pressures in the range of up to 40 GPa. Elastic properties of the samples were examined based on the measurements of a change of the lattice parameters with pressure. The results show a dual nature of the mechanical properties (compressibilities) of the materials, indicating a complex, core-shell structure of the grains.

Effect of solvents on optical band gap of silicon-doped graphene oxide

NASA Astrophysics Data System (ADS)

Tul Ain, Qura; Al-Modlej, Abeer; Alshammari, Abeer; Naeem Anjum, Muhammad

2018-03-01

The objective of this study was to determine the influence on the optical band gap when the same amount of silicon-doped graphene oxide was dissolved in three different solvents namely, distilled water, benzene, and dichloroethane. Ultraviolet-visible spectroscopy was used to analyse the optical properties of the solutions. Among all these solutions distilled water containing silicon-doped graphene oxide has the smallest optical band gap of 2.9 eV and is considered a semiconductor. Other solutions are not considered as semiconductors as they have optical band gaps greater than 4 eV. It was observed that there is an increase in the value of optical band gap of distilled water, benzene, and dichloroethane solutions indicating a rise in the insulating behaviour. In this experiment, graphene oxide was synthesised from graphite powder by modified Hummer’s method and was then doped with silicon. Synthesis and doping of graphene oxide were confirmed by various characterization techniques. Fourier transmission infrared spectroscopy was used for identification of surface functional groups. X-ray diffraction was carried out to confirm the formation of crystalline graphene oxide and silicon doped graphene oxide. In x-ray diffraction pattern, shifting of intensity peak from a 2θ value of 26.5° to 10° confirmed the synthesis of graphene oxide and various intensity peaks at different values of 2θ confirmed doping of graphene oxide with silicon. Scanning electron microscopy images indicated that graphene oxide sheets were decorated with spherical silicon nanoparticles. Energy dispersive x-ray spectroscopy showed that silicon doped graphene oxide powder contained 63.36% carbon, 34.05% oxygen, and 2.6% silicon.

Calculating cellulose diffraction patterns

USDA-ARS?s Scientific Manuscript database

Although powder diffraction of cellulose is a common experiment, the patterns are not widely understood. The theory is mathematical, there are numerous different crystal forms, and the conventions are not standardized. Experience with IR spectroscopy is not directly transferable. An awful error, tha...

Titration of a Solid Acid Monitored by X-Ray Diffraction

ERIC Educational Resources Information Center

Dungey, Keenan E.; Epstein, Paul

2007-01-01

An experiment is described to introduce students to an important class of solid-state reactions while reinforcing concepts of titration by using a pH meter and a powder X-ray diffractometer. The experiment was successful in teaching students the abstract concepts of solid-state structure and diffraction by applying the diffraction concepts learned…

Characterization of Metal Powders Used for Additive Manufacturing

PubMed Central

Slotwinski, JA; Garboczi, EJ; Stutzman, PE; Ferraris, CF; Watson, SS; Peltz, MA

2014-01-01

Additive manufacturing (AM) techniques1 can produce complex, high-value metal parts, with potential applications as critical parts, such as those found in aerospace components. The production of AM parts with consistent and predictable properties requires input materials (e.g., metal powders) with known and repeatable characteristics, which in turn requires standardized measurement methods for powder properties. First, based on our previous work, we assess the applicability of current standardized methods for powder characterization for metal AM powders. Then we present the results of systematic studies carried out on two different powder materials used for additive manufacturing: stainless steel and cobalt-chrome. The characterization of these powders is important in NIST efforts to develop appropriate measurements and standards for additive materials and to document the property of powders used in a NIST-led additive manufacturing material round robin. An extensive array of characterization techniques was applied to these two powders, in both virgin and recycled states. The physical techniques included laser diffraction particle size analysis, X-ray computed tomography for size and shape analysis, and optical and scanning electron microscopy. Techniques sensitive to structure and chemistry, including X-ray diffraction, energy dispersive analytical X-ray analysis using the X-rays generated during scanning electron microscopy, and X-Ray photoelectron spectroscopy were also employed. The results of these analyses show how virgin powder changes after being exposed to and recycled from one or more Direct Metal Laser Sintering (DMLS) additive manufacturing build cycles. In addition, these findings can give insight into the actual additive manufacturing process. PMID:26601040

Structure of N-(5-ethyl-[1,3,4]-thiadiazole-2-yl)toluenesulfonamide by combined X-ray powder diffraction, 13C solid-state NMR and molecular modelling.

PubMed

Hangan, Adriana; Borodi, Gheorghe; Filip, Xenia; Tripon, Carmen; Morari, Cristian; Oprean, Luminita; Filip, Claudiu

2010-12-01

The crystal structure solution of the title compound is determined from microcrystalline powder using a multi-technique approach that combines X-ray powder diffraction (XRPD) data analysis based on direct-space methods with information from (13)C solid-state NMR (SSNMR), and molecular modelling using the GIPAW (gauge including projector augmented-wave) method. The space group is Pbca with one molecule in the asymmetric unit. The proposed methodology proves very useful for unambiguously characterizing the supramolecular arrangement adopted by the N-(5-ethyl-[1,3,4]-thiadiazole-2-yl)toluenesulfonamide molecules in the crystal, which consists of extended double strands held together by C-H···π non-covalent interactions.

Crystal structure of paliperidone palmitate (INVEGA SUSTENNA®), C39H57FN4O4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaduk, James A.; Dmitrienko, Artem O.; Gindhart, Amy M.

2017-08-29

The crystal structure of paliperidone palmitate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Paliperidone palmitate crystallizes in space groupP2 1/c(#14) witha= 34.415 40(35),b= 10.093 49(7),c= 10.904 92(9) Å,β= 94.3917(9)°,V= 3776.94(6) Å 3, andZ= 4. The conformation of the paliperidone fragment differs from that of the parent compound. The palmitate chain exhibits a slight twist close to the ester group. Several C–H•••O hydrogen bonds contribute to the crystal packing, which is dominated by van der Waals interactions. The powder pattern is included in the Powder Diffraction File™ as entry 00-066-1614.

Nonvolatile RRAM cells from polymeric composites embedding recycled SiC powders.

PubMed

De Girolamo Del Mauro, Anna; Nenna, Giuseppe; Miscioscia, Riccardo; Freda, Cesare; Portofino, Sabrina; Galvagno, Sergio; Minarini, Carla

2014-10-21

Silicon carbide powders have been synthesized from tires utilizing a patented recycling process. Dynamic light scattering, Raman spectroscopy, SEM microscopy, and X-ray diffraction have been carried out to gather knowledge about powders and the final composite structure. The obtained powder has been proven to induce resistive switching in a PMMA polymer-based composite device. Memory effect has been detected in two-terminal devices having coplanar contacts and quantified by read-write-erase measurements in terms of level separation and persistence.

New process of preparation, X-ray characterisation, structure and vibrational studies of a solid solution LiTiOAs 1-xP xO 4 (0⩽ x⩽1)

NASA Astrophysics Data System (ADS)

Chakir, M.; El Jazouli, A.; Chaminade, J. P.; Bouree, F.; de Waal, D.

2006-01-01

LiTiOAs 1-xP xO 4 (0⩽ x⩽1) compounds have been prepared using solutions of Li, Ti, As and P elements as starting products. Selected compositions have been investigated by powder X-ray or neutrons diffraction analysis, Raman and infrared spectroscopy. The structure of LiTiOAs 1-xP xO 4 ( x=0, 0.5 and 1) samples determined by Rietveld analysis is orthorhombic with Pnma space group. It is formed by a 3D network of TiO 6 octahedra and XO 4 ( X=As 1-xP x) tetrahedra where octahedral cavities are occupied by lithium atoms. TiO 6 octahedra are linked together by corners and form infinite chains along a-axis. Ti atoms are displaced from the centre of octahedral units in alternating short (1.700-1.709 Å) and long (2.301-2.275 Å) Ti-O bonds. Raman and infrared studies confirm the existence of Ti-O-Ti chains. Thermal stability of LiTiOAsO 4 has been reported.

The effect of organic ligands on the crystallinity of calcium phosphate

NASA Astrophysics Data System (ADS)

van der Houwen, Jacqueline A. M.; Cressey, Gordon; Cressey, Barbara A.; Valsami-Jones, Eugenia

2003-03-01

Calcium phosphate phases precipitated under critical supersaturation were identified and studied in detail using X-ray powder diffraction, electron probe microanalysis, infrared spectroscopy (IR) and transmission electron microscopy. These synthetic calcium phosphates formed by spontaneous precipitation at pH 7, 25°C and 0.1 M ionic strength (NaCl as the background electrolyte). The combination of several methods allowed detailed characterisation of the calcium phosphates. The purpose of the work was to assess the influence of carboxylate ligands, specifically acetate and citrate, on the quality of the calcium phosphate precipitate. All precipitates were identified as non-stoichiometric, calcium-deficient hydroxylapatites (HAPs), containing carbonate, HPO 42-, sodium and chloride impurities. No other phases were found to be present in any of the precipitates. The presence of citrate resulted in a decrease in crystal size and a higher degree of apatite lattice imperfection in the precipitated HAP. Furthermore, IR spectroscopy showed a higher amount of carbonate present in that HAP, compared with the ones formed in the control and acetate experiments. An additional absorption band, in the infrared spectrum of the HAP formed in the presence of citrate, was observed at 1570 cm -1; this is interpreted as carboxyl groups bound to HAP.

Synthesis, characterization and anti-microbial activity of pure, Cu2+ and Cd2+ doped organic NLO l-arginine trifluoroacetate single crystals

NASA Astrophysics Data System (ADS)

Prasanyaa, T.; Haris, M.; Jayaramakrishnan, V.; Amgalan, M.; Mathivanan, V.

2013-10-01

Optically transparent Cu2+ and Cd2+ doped l-arginine trifluoroacetate (LATF) single crystals were grown from its aqueous solution using the slow solvent evaporation technique. The grown crystals were characterized by powder x-ray diffraction to confirm the monoclinic crystal structure. The percentage of transmittance measured using the ultraviolet-visible-near infrared spectrophotometer was found to be more than 80% for doped crystals. The functional group analysis of the grown crystals has been made by Fourier transform infrared spectroscopy. Thermogravimetric/differential thermal analysis was performed for the grown crystals. An atomic absorption study was carried out to determine the presence of Cu2+ and Cd2+. The hardness of the grown crystals was assessed and the results show a significant variation in the hardness value between the pure and doped LATF crystals. The second harmonic generation measurements show that Cu2+ doped LATF is 2.8 times greater and Cd2+ doped is 2.6 times greater than KDP. The anti-bacterial and anti-fungal activities of the title compound were performed using the disc diffusion method against standard bacteria Escherichia coli, Xanthomonas oryzae and against the fungus Aspergillus niger and Aspergillus flavus.

Melamine detection in infant formula powder using near- and mid-infrared spectroscopy.

PubMed

Mauer, Lisa J; Chernyshova, Alona A; Hiatt, Ashley; Deering, Amanda; Davis, Reeta

2009-05-27

Near- and mid-infrared spectroscopy methods (NIR, FTIR-ATR, FTIR-DRIFT) were evaluated for the detection and quantification of melamine in infant formula powder. Partial least-squares (PLS) models were established for correlating spectral data to melamine concentration: R(2) > 0.99, RMSECV ≤ 0.9, and RPD ≥ 12. Factorization analysis of spectra was able to differentiate unadulterated infant formula powder from samples containing 1 ppm melamine with no misclassifications, a confidence level of 99.99%, and selectivity > 2. These nondestructive methods require little or no sample preparation. The NIR method has an assay time of 1 min, and a 2 min total time to detection. The FTIR methods require up to 5 min for melamine detection. Therefore, NIR and FTIR methods enable rapid detection of 1 ppm melamine in infant formula powder.

Vibrational microspectroscopic identification of powdered traditional medicines: Chemical micromorphology of Poria observed by infrared and Raman microspectroscopy

NASA Astrophysics Data System (ADS)

Chen, Jian-bo; Sun, Su-qin; Ma, Fang; Zhou, Qun

2014-07-01

Microscopic identification using optical microscopes is a simple and effective method to identify powdered traditional medicines made from plants, animals and fungi. Sometimes, the criteria based on physical properties of the microscopic characteristics of drug powder may be ambiguous, which makes the microscopic identification method subjective and empirical to some extent. In this research, the vibrational microspectroscopic identification method is proposed for more explicit discrimination of powdered traditional medicines. The chemical micromorphology, i.e., chemical compositions and related physical morphologies, of the drug powder can be profiled objectively and quantitatively by infrared and Raman microspectroscopy, leading to better understanding about the formation mechanisms of microscopic characteristics and more accurate identification criteria. As an example, the powder of Poria, which is one of the most used traditional Chinese medicines, is studied in this research. Three types of hyphae are classified according to their infrared spectral features in the region from 1200 to 900 cm-1. Different kinds of polysaccharides indicate that these hyphae may be in different stages of the growth. The granular and branched clumps observed by the optical microscope may be formed from the aggregation of the mature hyphae with β-D-glucan reserves. The newfound spherical particles may originate from the exuded droplets in the fresh Poria because they are both composed of α-D-glucan. The results are helpful to understand the development of the hyphae and the formation of active polysaccharides in Poria and to establish accurate microspectroscopic identification criteria.

The elimination of zero-order diffraction of 10.6 μm infrared digital holography

NASA Astrophysics Data System (ADS)

Liu, Ning; Yang, Chao

2017-05-01

A new method of eliminating the zero-order diffraction in infrared digital holography has been raised in this paper. Usually in the reconstruction of digital holography, the spatial frequency of the infrared thermal imager, such as microbolometer, cannot be compared to the common visible CCD or CMOS devices. The infrared imager suffers the problems of large pixel size and low spatial resolution, which cause the zero-order diffraction a severe influence of the reconstruction process of digital holograms. The zero-order diffraction has very large energy and occupies the central region in the spectrum domain. In this paper, we design a new filtering strategy to overcome this problem. This filtering strategy contains two kinds of filtering process which are the Gaussian low-frequency filter and the high-pass phase averaging filter. With the correct set of the calculating parameters, these filtering strategies can work effectively on the holograms and fully eliminate the zero-order diffraction, as well as the two crossover bars shown in the spectrum domain. Detailed explanation and discussion about the new method have been proposed in this paper, and the experiment results are also demonstrated to prove the performance of this method.

Effect of boron on enhancing infrared emissivity of Ni-Cr system coating

NASA Astrophysics Data System (ADS)

Li, Yongjia; Ouyang, Taoyuan; Wang, Xiaohuan; Li, Shuhao; Mao, Jiawei; Cheng, Xudong

2018-03-01

High infrared emissivity coating possesses great value in practical application, whether in the military or civilian areas. In this study, B-NiCr precursor powder containing NiO, Cr2O3 and ZrB2 was calcined at 1300 °C and then used to prepare a high infrared emissivity B-NiCr coating via atmospheric plasma spraying. A large number of test methods were employed to analyze the powder and coating, including TG-DSC, XRD, FE-SEM, infrared spectrometer and so on. The result of infrared emissivity measurement indicates that the coating possesses maximum infrared emissivity of 0.908 at 1000 °C while the infrared emissivity is 0.901 after thermal shock test. Comparing with NiCr coating, Ni2CrO2(BO3) formed during calcination may be the main factor to improve the infrared emissivity of B-NiCr coating. The B-NiCr coating possesses good thermal shock resistance and can withstand 50 times thermal shock at least without falling off, from 800 °C to room temperature.

In situ synthesis of magnesium-substituted biphasic calcium phosphate and in vitro biodegradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Tae-Wan; Lee, Hyeong-Shin; Kim, Dong-Hyun

Highlights: ► Mg–BCP were successfully prepared through in situ aqueous co-precipitation method. ► The amount of β-TCP phase was changed with the magnesium substitution level. ► The substitution of magnesium led to a decrease in the unit cell volume. ► Mg–BCP could be able to develop a new apatite phase on the surface faster than BCP. -- Abstract: In situ preparation of magnesium (Mg) substituted biphasic calcium phosphate (BCP) of hydroxyapatite (HAp)/β-tricalcium phosphate (β-TCP) were carried out through aqueous co-precipitation method. The concentrations of added magnesium were varied with the calcium in order to obtain constant (Ca + Mg)/P ratiosmore » of 1.602. X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy were used to characterize the structure of synthesized magnesium substituted BCP powders. The results have shown that substitution of magnesium in the calcium deficient apatites revealed the formation of biphasic mixtures of different HAp/β-TCP ratios after heating at 1000 °C. The ratios of the formation of phase mixtures were dependent on the content of magnesium. After immersing in Hanks’ balanced salt solution (HBSS) for 1 week, 1 wt% magnesium substituted BCP powders were degraded and precipitation started to be formed with small granules consisting of number of flake-like crystal onto the surface of synthesized powders. On the other hand, in the case of pure BCP powders, the formation of new precipitates was detected after immersion in HBSS for 2 weeks. On the basis of these results, magnesium substituted BCP could be able to develop a new apatite phase on the surface in contact with physiological fluids faster than BCP does. In addition, the retention time to produce the new apatite phase in implantation operation for the BCP powder could be controlled by the amount of magnesium substitution.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aldridge, James D.; Womick, Jordan M.; Rosmus, Kimberly A.

Novel quaternary lanthanide-substituted oxides of stoichiometry LnxY2-xTi2O7 (where Ln is lanthanum, neodymium, samarium, gadolinium, or ytterbium) were prepared by traditional high-temperature, solid-state techniques and characterized by X-ray powder diffraction. Samples with nominal values of x up to 1.0 were attempted. The well-studied ternary cubic pyrochlore compound yttrium titanium oxide (Y2Ti2O7, space group Fd-3m, Z = 8), served as a parent structural framework in which Ln3+ cations were substituted on the Y3+ site. Laboratory-grade X-ray powder diffraction data revealed pure quaternary pyrochlore phases for LnxY2-xTi2O7 with x ≤ 0.2. Pyrochlore phase purity was verified by Rietveld analysis using high-resolution synchrotron X-raymore » powder diffraction data when x ≤ 0.2, however, for La3+ substitution specifically, pure quaternary pyrochlore formed at x<0.1. Band gap energies on selected samples were determined using optical diffuse reflectance spectroscopy and showed that these materials can be classified as electrical insulators with indirect band gap energies around 3.7 eV.« less

Real-time monitoring of laser powder bed fusion process using high-speed X-ray imaging and diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Cang; Fezzaa, Kamel; Cunningham, Ross W.

Here, we employ the high-speed synchrotron hard X-ray imaging and diffraction techniques to monitor the laser powder bed fusion (LPBF) process of Ti-6Al-4V in situ and in real time. We demonstrate that many scientifically and technologically significant phenomena in LPBF, including melt pool dynamics, powder ejection, rapid solidification, and phase transformation, can be probed with unprecedented spatial and temporal resolutions. In particular, the keyhole pore formation is experimentally revealed with high spatial and temporal resolutions. The solidification rate is quantitatively measured, and the slowly decrease in solidification rate during the relatively steady state could be a manifestation of the recalescencemore » phenomenon. The high-speed diffraction enables a reasonable estimation of the cooling rate and phase transformation rate, and the diffusionless transformation from β to α’ phase is evident. The data present here will facilitate the understanding of dynamics and kinetics in metal LPBF process, and the experiment platform established will undoubtedly become a new paradigm for future research and development of metal additive manufacturing.« less

Structural properties of a family of hydrogen-bonded co-crystals formed between gemfibrozil and hydroxy derivatives of t-butylamine, determined directly from powder X-ray diffraction data

NASA Astrophysics Data System (ADS)

Cheung, Eugene Y.; David, Sarah E.; Harris, Kenneth D. M.; Conway, Barbara R.; Timmins, Peter

2007-03-01

We report the formation and structural properties of co-crystals containing gemfibrozil and hydroxy derivatives of t-butylamine H 2NC(CH 3) 3-n(CH 2OH) n, with n=0, 1, 2 and 3. In each case, a 1:1 co-crystal is formed, with transfer of a proton from the carboxylic acid group of gemfibrozil to the amino group of the t-butylamine derivative. All of the co-crystal materials prepared are polycrystalline powders, and do not contain single crystals of suitable size and/or quality for single crystal X-ray diffraction studies. Structure determination of these materials has been carried out directly from powder X-ray diffraction data, using the direct-space Genetic Algorithm technique for structure solution followed by Rietveld refinement. The structural chemistry of this series of co-crystal materials reveals well-defined structural trends within the first three members of the family ( n=0, 1, 2), but significantly contrasting structural properties for the member with n=3.

Real-time monitoring of laser powder bed fusion process using high-speed X-ray imaging and diffraction

DOE PAGES

Zhao, Cang; Fezzaa, Kamel; Cunningham, Ross W.; ...

2017-06-15

Here, we employ the high-speed synchrotron hard X-ray imaging and diffraction techniques to monitor the laser powder bed fusion (LPBF) process of Ti-6Al-4V in situ and in real time. We demonstrate that many scientifically and technologically significant phenomena in LPBF, including melt pool dynamics, powder ejection, rapid solidification, and phase transformation, can be probed with unprecedented spatial and temporal resolutions. In particular, the keyhole pore formation is experimentally revealed with high spatial and temporal resolutions. The solidification rate is quantitatively measured, and the slowly decrease in solidification rate during the relatively steady state could be a manifestation of the recalescencemore » phenomenon. The high-speed diffraction enables a reasonable estimation of the cooling rate and phase transformation rate, and the diffusionless transformation from β to α’ phase is evident. The data present here will facilitate the understanding of dynamics and kinetics in metal LPBF process, and the experiment platform established will undoubtedly become a new paradigm for future research and development of metal additive manufacturing.« less

Raman scattering and X-ray powder diffraction studies of hydrate layered perovskites: dirubidium aquapentafluoromanganate(III) and dipotassium aquapentafluoroferrate(III)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galicka, Karolina; Slodczyk, Aneta; Ratuszna, Alicja

2004-06-08

The structural and vibrational properties of above mentioned crystals were determined using X-ray powder diffraction and Raman scattering experiments. At room temperature hydrate layered perovskites: Rb{sub 2}MnF{sub 5}{center_dot}H{sub 2}O and K{sub 2}FeF{sub 5}{center_dot}H{sub 2}O exhibit orthorhombic--Cmcm (D{sub 2h}{sup 17}) and monoclinic--C2/c (C{sub 2h}{sup 6}) symmetry. Their structure is built up of MnF{sub 6} or FeF{sub 5}{center_dot}H{sub 2}O octahedra forming trans-linked zig-zag chains or hydrogen bonded zig-zag chains along the major crystallographic direction [0 0 1], respectively. To confirm crystal structures and to describe lattice dynamics of these compounds the vibrational normal modes (in {gamma} point of first Brillouin zone) weremore » calculated on the base of the group theory analysis and compared with the spectra obtained from Raman scattering experiments. A relatively good reliability was obtained for both X-ray powder diffraction and Raman scattering.« less

Infrared-optical transmission and reflection measurements on loose powders

NASA Astrophysics Data System (ADS)

Kuhn, J.; Korder, S.; Arduini-Schuster, M. C.; Caps, R.; Fricke, J.

1993-09-01

A method is described to determine quantitatively the infrared-optical properties of loose powder beds via directional-hemispherical transmission and reflection measurements. Instead of the integration of the powders into a potassium bromide (KBr) or a paraffin oil matrix, which would drastically alter the scattering behavior, the powders are placed onto supporting layers of polyethylene (PE) and KBr. A commercial spectrometer is supplemented by an external optics, which enables measurements on horizontally arranged samples. For data evaluation we use a solution of the equation of radiative transfer in the 3-flux approximation under boundary conditions adapted to the PE or KBr/powder system. A comparison with Kubelka-Munk's theory and Schuster's 2-flux approximation is performed, which shows that 3-flux approximation yields results closest to the exact solution. Equations are developed, which correct transmission and reflection of the samples for the influence of the supporting layer and calculate the specific extinction and the albedo of the powder and thus enables us to separate scattering and absorption part of the extinction spectrum. Measurements on TiO2 powder are presented, which show the influence of preparation techniques and data evaluation with different methods to obtain the albedo. The specific extinction of various TiO2 powders is presented.

Investigation of phase evolution of CaCu3Ti4O12 (CCTO) by in situ synchrotron high-temperature powder diffraction

NASA Astrophysics Data System (ADS)

Ouyang, Xin; Huang, Saifang; Zhang, Weijun; Cao, Peng; Huang, Zhaohui; Gao, Wei

2014-03-01

In situ synchrotron X-ray powder diffraction was used to study the high-temperature phase evolution of CaCu3Ti4O12 (CCTO) precursors prepared via solid-state and sol-gel methods. After the precursors are heated to 1225 °C, the CCTO phase is the main phase observed in the calcined powder, with the presence of some minor impurities. Comparing the two precursors, we found that the onset temperature for the CCTO phase formation is 800 °C in the sol-gel precursor, lower than that in the solid-state precursor (875 °C). Intermediate phases were only observed in the sol-gel precursor. Both precursors are able to be calcined to sub-micrometric sized powders. Based on the synchrotron data along with differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), the phase formation sequence and mechanism during calcination are proposed in this study.

Development of Cu Reinforced SiC Particulate Composites

NASA Astrophysics Data System (ADS)

Singh, Harshpreet; Kumar, Lailesh; Nasimul Alam, Syed

2015-02-01

This paper presents the results of Cu-SiCp composites developed by powder metallurgy route and an attempt has been made to make a comparison between the composites developed by using unmilled Cu powder and milled Cu powder. SiC particles as reinforcement was blended with unmilled and as-milled Cu powderwith reinforcement contents of 10, 20, 30, 40 vol. % by powder metallurgy route. The mechanical properties of pure Cu and the composites developed were studied after sintering at 900°C for 1 h. Density of the sintered composites were found out based on the Archimedes' principle. X-ray diffraction of all the composites was done in order to determine the various phases in the composites. Scanning electron microscopy (SEM) and EDS (electron diffraction x-ray spectroscopy) was carried out for the microstructural analysis of the composites. Vickers microhardness tester was used to find out the hardness of the samples. Wear properties of the developed composites were also studied.

Application of Powder Diffraction Methods to the Analysis of Short- and Long-Range Atomic Order in Nanocrystalline Diamond and SiC: The Concept of the Apparent Lattice Parameter (alp)

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Gierlotka, S.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Weber, H.-P.; Palosz, W.

2003-01-01

Two methods of the analysis of powder diffraction patterns of diamond and SiC nanocrystals are presented: (a) examination of changes of the lattice parameters with diffraction vector Q ('apparent lattice parameter', alp) which refers to Bragg scattering, and (b), examination of changes of inter-atomic distances based on the analysis of the atomic Pair Distribution Function, PDF. Application of these methods was studied based on the theoretical diffraction patterns computed for models of nanocrystals having (i) a perfect crystal lattice, and (ii), a core-shell structure, i.e. constituting a two-phase system. The models are defined by the lattice parameter of the grain core, thickness of the surface shell, and the magnitude and distribution of the strain field in the shell. X-ray and neutron experimental diffraction data of nanocrystalline SiC and diamond powders of the grain diameter from 4 nm up to micrometers were used. The effects of the internal pressure and strain at the grain surface on the structure are discussed based on the experimentally determined dependence of the alp values on the Q-vector, and changes of the interatomic distances with the grain size determined experimentally by the atomic Pair Distribution Function (PDF) analysis. The experimental results lend a strong support to the concept of a two-phase, core and the surface shell structure of nanocrystalline diamond and SiC.

Fourier Transforms Simplified: Computing an Infrared Spectrum from an Interferogram

ERIC Educational Resources Information Center

Hanley, Quentin S.

2012-01-01

Fourier transforms are used widely in chemistry and allied sciences. Examples include infrared, nuclear magnetic resonance, and mass spectroscopies. A thorough understanding of Fourier methods assists the understanding of microscopy, X-ray diffraction, and diffraction gratings. The theory of Fourier transforms has been presented in this "Journal",…

A general method for baseline-removal in ultrafast electron powder diffraction data using the dual-tree complex wavelet transform.

PubMed

René de Cotret, Laurent P; Siwick, Bradley J

2017-07-01

The general problem of background subtraction in ultrafast electron powder diffraction (UEPD) is presented with a focus on the diffraction patterns obtained from materials of moderately complex structure which contain many overlapping peaks and effectively no scattering vector regions that can be considered exclusively background. We compare the performance of background subtraction algorithms based on discrete and dual-tree complex (DTCWT) wavelet transforms when applied to simulated UEPD data on the M1-R phase transition in VO 2 with a time-varying background. We find that the DTCWT approach is capable of extracting intensities that are accurate to better than 2% across the whole range of scattering vector simulated, effectively independent of delay time. A Python package is available.

In Situ Neutron Diffraction of Rare-Earth Phosphate Proton Conductors Sr/Ca-doped LaPO4 at Elevated Temperatures

NASA Astrophysics Data System (ADS)

Al-Wahish, Amal; Al-Binni, Usama; Bridges, C. A.; Huq, A.; Bi, Z.; Paranthaman, M. P.; Tang, S.; Kaiser, H.; Mandrus, D.

Acceptor-doped lanthanum orthophosphates are potential candidate electrolytes for proton ceramic fuel cells. We combined neutron powder diffraction (NPD) at elevated temperatures up to 800° C , X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) to investigate the crystal structure, defect structure, thermal stability and surface topography. NPD shows an average bond length distortion in the hydrated samples. We employed Quasi-Elastic Neutron Scattering (QENS) and electrochemical impedance spectroscopy (EIS) to study the proton dynamics of the rare-earth phosphate proton conductors 4.2% Sr/Ca-doped LaPO4. We determined the bulk diffusion and the self-diffusion coefficients. Our results show that QENS and EIS are probing fundamentally different proton diffusion processes. Supported by the U.S. Department of Energy.

X-ray diffraction study of the caged magnetic compound DyFe 2 Zn 20 at low temperatures

NASA Astrophysics Data System (ADS)

Ohashi, M.; Ohashi, K.; Sawabu, M.; Miyagawa, M.; Maeta, K.; Isikawa, Y.

2018-05-01

We have carried out high-angle X-ray powder diffraction measurements of the caged magnetic compound DyFe2Zn20 at low temperature between 14 and 300 K. Even though a strong magnetic anisotropy exists in the magnetization and magnetic susceptibility due to strong exchange interaction between Fe and Dy, almost all X-ray powder diffraction peaks correspond to Bragg reflections of the cubic structural models not only at room temperature paramagnetic state but also at low temperature magnetic ordering state. The Debye temperature is obtained to be 227 K from the results of the volumetric thermal expansion coefficient, which is approximately coincident with that of CeRu2Zn20 (245 K) and that of pure Zn metal (235 K).

Structural and optical properties of furfurylidenemalononitrile thin films

NASA Astrophysics Data System (ADS)

Ali, H. A. M.

2013-03-01

Thin films of furfurylidenemalononitrile (FMN) were deposited on different substrates at room temperature by thermal evaporation technique under a high vacuum. The structure of the powder was confirmed by Fourier transformation infrared (FTIR) technique. The unit cell dimensions were determined from X-ray diffraction (XRD) studies. The optical properties were investigated using spectrophotometric measurements of the transmittance and reflectance at normal incidence of light in the wavelength range from 200 to 2500 nm. The refractive index (n), the absorption index (k) and the absorption coefficient (α) were calculated. The analysis of the spectral behavior of the absorption coefficient in the absorption region revealed an indirect allowed transition. The refractive index dispersion was analyzed using the single oscillator model. Some dispersion parameters were estimated. Complex dielectric function and optical conductivity were determined. The influence of the irradiation with high-energy X-rays (6 MeV) on the studied properties was also investigated.

Synthesis of imine bond containing insoluble polymeric ligand and its transition metal complexes, structural characterization and catalytic activity on esterification reaction.

PubMed

Gönül, İlyas; Ay, Burak; Karaca, Serkan; Saribiyik, Oguz Yunus; Yildiz, Emel; Serin, Selahattin

2017-01-01

In this study, synthesis of insoluble polymeric ligand (L) and its transition metal complexes [Cu(L)Cl 2 ]·2H 2 O (1) , [Co(L)Cl 2 (H 2 O) 2 ] (2) and [Ni(L)Cl 2 (H 2 O) 2 ] (3) , having the azomethine groups, were synthesized by the condensation reactions of the diamines and dialdehydes. The structural properties were characterized by the analytical and spectroscopic methods using by elemental analysis, Fourier Transform Infrared, Thermo Gravimetric Analysis, Powder X-ray Diffraction, magnetic susceptibility and Inductively Coupled Plasma. The solubilities of the synthesized polymeric materials were also investigated and found as insoluble some organic and inorganic solvents. Additionally, their catalytic performance was carried out for the esterification reaction of acetic acid and butyl acetate. The highest conversion rate is 75.75% by using catalyst 1 . The esterification of butanol gave butyl acetate with 100% selectivity.

Reflection and Transmission Coefficient of Yttrium Iron Garnet Filled Polyvinylidene Fluoride Composite Using Rectangular Waveguide at Microwave Frequencies

PubMed Central

Soleimani, Hassan; Abbas, Zulkifly; Yahya, Noorhana; Shameli, Kamyar; Soleimani, Hojjatollah; Shabanzadeh, Parvaneh

2012-01-01

The sol-gel method was carried out to synthesize nanosized Yttrium Iron Garnet (YIG). The nanomaterials with ferrite structure were heat-treated at different temperatures from 500 to 1000 °C. The phase identification, morphology and functional groups of the prepared samples were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. The YIG ferrite nanopowder was composited with polyvinylidene fluoride (PVDF) by a solution casting method. The magnitudes of reflection and transmission coefficients of PVDF/YIG containing 6, 10 and 13% YIG, respectively, were measured using rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in X-band frequencies. The results indicate that the presence of YIG in polymer composites causes an increase in reflection coefficient and decrease in transmission coefficient of the polymer. PMID:22942718

Polyethyleneimine-modified superparamagnetic Fe3O4 nanoparticles: An efficient, reusable and water tolerance nanocatalyst

NASA Astrophysics Data System (ADS)

Khoobi, Mehdi; Delshad, Tayebeh Modiri; Vosooghi, Mohsen; Alipour, Masoumeh; Hamadi, Hosein; Alipour, Eskandar; Hamedani, Majid Pirali; Sadat ebrahimi, Seyed Esmaeil; Safaei, Zahra; Foroumadi, Alireza; Shafiee, Abbas

2015-02-01

A novel magnetically separable catalyst was prepared based on surface modification of Fe3O4 magnetic nanoparticle (MNPs) with polyethyleneimine (PEI) via covalent bonding. [3-(2,3-Epoxypropoxy)propyl]trimethoxysilane (EPO) was used as cross linker to bond PEI on the surface of MNPs with permanent stability in contrast to PEI coating via electrostatic interactions. The synthesized catalyst was characterized by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The catalyst show high efficiency for one-pot synthesis of 2-amino-3-cyano-4H-pyran derivatives via multi-component reaction (MCR). This procedure offers the advantages of green reaction media, high yield, short reaction time, easy purification of the products and simple recovery and reuse of the catalyst by simple magnetic decantation without significant loss of catalytic activity.

Microwave mediated synthesis of ZnS spherical nanoparticles for IR optical ceramics

NASA Astrophysics Data System (ADS)

Ravichandran, D.; Wharton, T.; Devan, B.; Korenstein, R.; Tustison, R.; Komarneni, S.

2011-06-01

The existing material choice for long-wave infrared (LWIR) and semi-active laser domes is multispectral zinc sulfide (ZnS), made by chemical vapor deposition. An alternative route to make more erosion-resistant ZnS could be through hot pressing ZnS nanoparticles into small-grain material. We have attempted to produce ZnS nanoparticles both by microwave and microwave-hydrothermal methods. Microwave route produced ultrahigh purity, homogeneous, well dispersed, and uniformly spherical ZnS nanoparticles. Microwave-hydrothermal route produced equiaxed cubic-faceted nanoparticles. The powder X-ray diffraction patterns of ZnS shows the presence of broad reflections corresponding to the (1 1 1), (2 2 0), and (3 1 1) planes of the cubic crystalline ZnS material. The domain size of the particles estimated from the Debye-Scherrer formula for the main reflection (111) gives a value of 2.9 and 2.5 for the microwave and microwave-hydrothermal methods respectively.

Sonochemically synthesized MnO2 nanoparticles as electrode material for supercapacitors.

PubMed

Gnana Sundara Raj, Balasubramaniam; Asiri, Abdullah M; Qusti, Abdullah H; Wu, Jerry J; Anandan, Sambandam

2014-11-01

In this study, manganese oxide (MnO2) nanoparticles were synthesized by sonochemical reduction of KMnO4 using polyethylene glycol (PEG) as a reducing agent as well as structure directing agent under room temperature in short duration of time and characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM), Transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis. A supercapacitor device constructed using the ultrasonically-synthesized MnO2 nanoparticles showed maximum specific capacitance (SC) of 282Fg(-1) in the presence of 1M Ca(NO3)2 as an electrolyte at a current density of 0.5mAcm(-2) in the potential range from 0.0 to 1.0V and about 78% of specific capacitance was retained even after 1000 cycles indicating its high electrochemical stability. Copyright © 2013 Elsevier B.V. All rights reserved.

Synthesis, crystal growth, structural, thermal, optical and mechanical properties of solution grown 4-methylpyridinium 4-hydroxybenzoate single crystal.

PubMed

Sudhahar, S; Krishna Kumar, M; Sornamurthy, B M; Mohan Kumar, R

2014-01-24

Organic nonlinear optical material, 4-methylpyridinium 4-hydroxybenzoate (4MPHB) was synthesized and single crystal was grown by slow evaporation solution growth method. Single crystal and powder X-ray diffraction analyses confirm the structure and crystalline perfection of 4MPHB crystal. Infrared, Raman and NMR spectroscopy techniques were used to elucidate the functional groups present in the compound. TG-DTA analysis was carried out in nitrogen atmosphere to study the decomposition stages, endothermic and exothermic reactions. UV-visible and Photoluminescence spectra were recorded for the grown crystal to estimate the transmittance and band gap energy respectively. Linear refractive index, birefringence, and SHG efficiency of the grown crystal were studied. Laser induced surface damage threshold and mechanical properties of grown crystal were studied to assess the suitability of the grown crystals for device applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Luminescence studies of CdS spherical particles via hydrothermal synthesis

NASA Astrophysics Data System (ADS)

Xu, Guo Qin; Liu, Bing; Xu, Shi Jie; Chew, Chwee Har; Chua, Soo Jin; Gana, Leong Ming

2000-06-01

The spherical particles of CdS consisting of nanoparticles (∼100 nm) were synthesized by a hydrothermal process. The particle formation and growth depend on the rate of sulfide-ion generation and diffusion-controlled aggregation of nanoparticles. As demonstrated in the profiles of powder X-ray diffraction, the crystalline phases are governed by the reaction temperature. Photoluminescence studies on CdS particles show two emission bands at the room temperature. The red emission at 680 nm is due to sulfur vacancies, and a new infrared red (IR) emission at 760 nm is attributed to self-activated centers. A red shift of IR band with the decrease of temperature was explained with a configurational coordinate model. The different saturation limits for the red and IR bands are discussed in terms of the formation of donor-acceptor pairs and exciton in CdS particles.

Rapid hydrothermal synthesis of VO2 (B) and its conversion to thermochromic VO2 (M1).

PubMed

Popuri, Srinivasa Rao; Miclau, Marinela; Artemenko, Alla; Labrugere, Christine; Villesuzanne, Antoine; Pollet, Michaël

2013-05-06

The present study provides a rapid way to obtain VO2 (B) under economical and environmentally friendly conditions. VO2 (B) is one of the well-known polymorphs of vanadium dioxide and is a promising cathode material for aqueous lithium ion batteries. VO2 (B) was successfully synthesized by rapid single-step hydrothermal process using V2O5 and citric acid as precursors. The present study shows that phase-pure VO2 (B) polytype can be easily obtained at 180 °C for 2 h and 220 °C for 1 h, that is, the lowest combination of temperature and duration reported so far. The obtained VO2 (B) is characterized by X-ray powder diffraction, high-resolution scanning electron microscopy, and Fourier transform infrared spectroscopy. In addition, we present an indirect way to obtain VO2 (M1) by annealing VO2 (B) under vacuum for 1 h.

New opportunities in the preparation of nanocomposites for biomedical applications: revised mechanosynthesis of magnetite-silica nanocomposites

NASA Astrophysics Data System (ADS)

Scano, Alessandra; Cabras, Valentina; Marongiu, Francesca; Peddis, Davide; Pilloni, Martina; Ennas, Guido

2017-02-01

Environmentally friendly preparation of functionalized magnetite-silica (Fe3O4/SiO2) nanocomposites (NCs) with different SiO2 content (6, 20 and 50 wt%) using revised mechanosynthesis is reported. High-energy ball milling of α-Fe2O3, Si and SiO2 mixtures was followed by hydrolysis and condensation of 3-aminopropyl-triethoxysilane. X-ray powder diffraction and transmission electron microscopy showed the formation of almost spherical Fe3O4 nanocrystals with a narrow size distribution (4-6 nm) uniformly dispersed in the amorphous 100-200 nm SiO2 agglomerates. Scanning electron microscopy and energy dispersive spectroscopy were used to study the elemental distribution in the sample. Fourier transform infrared spectroscopy confirmed the NC surface functionalization with amino groups. Magnetic properties were also explored, indicating a homogeneous distribution of magnetic nanoparticles in the silica matrix.

Reusable magnetic nanobiocatalyst for synthesis of silver and gold nanoparticles.

PubMed

Mazumder, Jahirul Ahmed; Ahmad, Razi; Sardar, Meryam

2016-12-01

In the present work, we describe a simple procedure for the biosynthesis of nanosilver and gold by the reduction of silver nitrate and auric chloride respectively using a nanobiocatalyst. The nanobiocatalyst was prepared by covalent coupling of alpha amylase on (3-aminopropyl)triethoxysilane (APTES) modified iron oxide magnetic nanoparticles. The nanobiocatalyst retains 77% of its activity as compared to free alpha amylase. The nanobiocatalyst can be used up to three consecutive cycles for the synthesis of nano silver and gold. The biosynthesized nanoparticles after each cycle were characterized by UV-vis spectrophotometer, Dynamic Light Spectroscopy (DLS), Transmission Electron Microscope (TEM), X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Silver and gold nanoparticles of same morphology and dimensions were formed in each cycle. The procedure for synthesis of nanoparticles using an immobilized enzyme is eco-friendly and can be used repeatedly. Copyright © 2016 Elsevier B.V. All rights reserved.

Low-cost and eco-friendly synthesis of silver nanoparticles using coconut (Cocos nucifera) oil cake extract and its antibacterial activity.

PubMed

Govarthanan, Muthusamy; Seo, Young-Seok; Lee, Kui-Jae; Jung, Ik-Boo; Ju, Ho-Jong; Kim, Jae Su; Cho, Min; Kamala-Kannan, Seralathan; Oh, Byung-Taek

2016-12-01

The present study reports the simple, inexpensive, eco-friendly synthesis of silver nanoparticles (AgNPs) using coconut oil cake extract. Scanning electron microscopy-energy dispersive spectroscopy peak at 3 keV confirmed the presence of silver. Transmission electron micrograph showed that nanoparticles are mostly circular with an average size of 10-70 nm. The results of the X-ray powder diffraction analysis (2θ = 46.2, 67.4 and 76.8) indicated the crystal nature of the AgNPs. Fourier transform infrared spectroscopy analysis indicates that proteins present in the oilcake extract could be responsible for the reduction of silver ions. The synthesized AgNPs (1-4 mm) reduced the growth rate of multi-antibiotic-resistant bacteria such as Aeromonas sp., Acinetobacter sp. and Citrobacter sp. isolated from livestock wastewater.

New solid state forms of antineoplastic 5-fluorouracil with anthelmintic piperazine

NASA Astrophysics Data System (ADS)

Moisescu-Goia, C.; Muresan-Pop, M.; Simon, V.

2017-12-01

The aim of the present study was to asses the formation of solid forms between the 5-fluorouracil chemotherapy drug and the anthelmintic piperazine. Two new solid forms of antineoplastic agent 5-fluorouracil with anthelmintic piperazine were obtained by liquid assisted ball milling and slurry crystallization methods. The Nsbnd H hydrogen bonding donors and C = O hydrogen bonding acceptors of 5-fluorouracil allow to form co-crystals with other drugs delivering improved properties for medical applications, as proved for other compounds of pharmaceutical interest. Both new solid forms were investigated using X-ray powder diffraction (XRD), differential thermal analysis (DTA) and Fourier transform infrared (FTIR) spectroscopy. The XRD results show that by both methods were successfully synthesized new solid forms of 5-fluorouracil with piperazine. According to FTIR results the form prepared by lichid assisted grinding process was obtained as co-crystal and the other one, prepared by slurry method, resulted as a salt.

A Potential Waste to be Selected as Media for Metal and Nutrient Removal

NASA Astrophysics Data System (ADS)

Zayadi, N.; Othman, N.; Hamdan, R.

2016-07-01

This study describes the potential of application of cassava peel, banana peel, coconut shell, and coconut coir to be selected as metal removal while limestone and steel slag for nutrient removal. The media were characterized by X-Ray Fluorescence (XRF), Fourier Transform Infrared (FTIR), Field Emission Scanning Electron Microscopy-Energy Dispersive X-Ray (FESEM-EDX), and X-Ray Powder Diffraction (XRD). The results of XRF analysis medias show the present of calcium oxide, CaO which confirm the high efficiency in adsorbing metal ions and nutrient which is in agreement with the result of XRD. The characteristics of medias by FTIR analysis also confirmed the involvement of alcohol, carboxylic, alkanes, amines and ethers which play important role to reduce ions while FESEM-EDX indicates the porous structures of study medias. The characterization analysis highlight that cassava peel and steel slag were selected as a potential media in this study.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Xin-Yu; Zhu, Ying-Jie, E-mail: y.j.zhu@mail.sic.ac.cn; Lu, Bing-Qiang

Graphical abstract: Hydroxyapatite nanorods are synthesized using biocompatible biomolecule pyridoxal-5′-phosphate as a new organic phosphorus source by the hydrothermal method. - Highlights: • Hydrothermal synthesis of hydroxyapatite nanorods is reported. • Biocompatible pyridoxal-5′-phosphate is used as an organic phosphorus source. • This method is simple, surfactant-free and environmentally friendly. - Abstract: Hydroxyapatite nanorods are synthesized by the hydrothermal method using biocompatible biomolecule pyridoxal-5′-phosphate (PLP) as a new organic phosphorus source. In this method, PLP biomolecules are hydrolyzed to produce phosphate ions under hydrothermal conditions, and these phosphate ions react with pre-existing calcium ions to form hydroxyapatite nanorods. The effects ofmore » experimental conditions including hydrothermal temperature and time on the morphology and crystal phase of the products are investigated. This method is simple, surfactant-free and environmentally friendly. The products are characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric (TG) analysis.« less

Synthesis, characterization, bioactivity and antibacterial studies of silver doped calcium borosilicate glass-ceramics

NASA Astrophysics Data System (ADS)

Kumar, Alesh; Mariappan, C. R.

2018-04-01

Bioactive glass-ceramics 45.8 mol% SiO- 45.8 CaO - 8.4 B2O3 doped with Ag2O were synthesized by sol-gel method. The glass-ceramic nature of samples was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. Fourier transform infrared (FT-IR) spectra reveal the probable stretching and bending vibration modes of silicate and borate groups. UV-Visible spectra reveal the presence of Ag+ ions and metallic Ag in the glass matrix for Ag2O doped ceramic sample. Biocompatibility of the glass nature of samples was studied by soaking of samples in Dulbecco's Modified Eagle's Medium (DMEM) with subsequent XRD studies. It was found that bone-like apatite formation on the glasses after soaked in DMEM. Antibacterial studies of glass ceramics powder against gram positive and negative microorganisms were carried out.

Physicochemical and mechanical properties of paracetamol cocrystal with 5-nitroisophthalic acid.

PubMed

Hiendrawan, Stevanus; Veriansyah, Bambang; Widjojokusumo, Edward; Soewandhi, Sundani Nurono; Wikarsa, Saleh; Tjandrawinata, Raymond R

2016-01-30

We report novel pharmaceutical cocrystal of a popular antipyretic drug paracetamol (PCA) with coformer 5-nitroisophhthalic acid (5NIP) to improve its tabletability. The cocrystal (PCA-5NIP at molar ratio of 1:1) was synthesized by solvent evaporation technique using methanol as solvent. The physicochemical properties of cocrystal were characterized by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), fourier transform infrared spectroscopy (FTIR), hot stage polarized microscopy (HSPM) and scanning electron microscopy (SEM). Stability of the cocrystal was assessed by storing them at 40°C/75% RH for one month. Compared to PCA, the cocrystal displayed superior tableting performance. PCA-5NIP cocrystal showed a similar dissolution profile as compared to PCA and exhibited good stability. This study showed the utility of PCA-5NIP cocrystal for improving mechanical properties of PCA. Copyright © 2015 Elsevier B.V. All rights reserved.

Preparation and characterization of photoactive composite kaolinite/TiO(2).

PubMed

Mamulová Kutláková, K; Tokarský, J; Kovář, P; Vojtěšková, S; Kovářová, A; Smetana, B; Kukutschová, J; Čapková, P; Matějka, V

2011-04-15

Preparation of nanocomposite kaolinite/TiO(2), using hydrolysis of titanyl sulfate in the presence of kaolin was addressed. A variable (kaolin)/(titanyl sulfate) ratio has been used in order to achieve the desired TiO(2) content in prepared nanocomposites. Calcination of the composites at 600 °C led to the transformation of the kaolinite to metakaolinite and to origination of metakaolinite/TiO(2) composites. The prepared samples were investigated using X-ray fluorescence spectroscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetry and diffuse reflectance spectroscopy in the UV-VIS region. Structural ordering of TiO(2) on the kaolinite particle surface was modeled using empirical force field atomistic simulations in the Material Studio modeling environment. Photodegradation activity of the composites prepared was evaluated by the discoloration of Acid Orange 7 aqueous solution. Copyright © 2011 Elsevier B.V. All rights reserved.

Titan's Lakes in a Beaker

NASA Astrophysics Data System (ADS)

Hodyss, R. P.

2017-12-01

The surface of Titan presents a complex, varied surfaced, with mountains, plains, dunes, rivers, lakes and seas, composed of a layer of organics over a water ice bedrock. Over the past 10 years, our group at JPL has developed a variety of techniques to study the chemistry of Titan's organic surface under relevant temperature and pressure conditions (90-100 K, 1.5 bar). Dissolution, precipitation, and both covalent and non-covalent chemical processes are examined using Raman and infrared spectroscopy, mass spectrometry, optical microscopy, and synchrotron X-ray powder diffraction. Despite the low temperatures, our experiments are revealing that a rich and active organic chemistry is possible on Titan's surface. Laboratory experiments like these can provide crucial insights into the geological processes occurring Titan's surface, and help explain the wealth of observational data returned by the Cassini/Huygens mission. This type of data is also critical for the development of future missions to Titan.

Fabrication of (K0.5Na0.5)(Nb0.7Ta0.3)O3 thick films by electrophoretic deposition

NASA Astrophysics Data System (ADS)

Vineetha, P.; Saravanan, K. Venkata

2018-05-01

(K0.5Na0.5)(Nb0.7Ta0.3)O3 (KNNT) thick films were prepared by electrophoretic deposition method on copper plates (substrates). Prior to the deposition, stable suspensions of KNNT powder were prepared in isopropyl alcohol medium with and without adding triethanolamine (TEA) as dispersant. The optical transmittance spectra with time for both the suspensions were recorded and compared. Suspensions with dispersant has shown low transmittance, which indicate that the particles were dispersed very well in isopropyl alcohol. Fourier Transform Infrared (FTIR) spectroscopy was used to analyze the adsorption of TEA on KNNT particles. Suspension with dispersant was used for electrophoretic deposition. The depositions were carried out at various d.c voltages, keeping the deposition duration and inter electrode distance constant. X-Ray diffraction was used for the phase analysis of the films.

Sol-gel synthesis, phase composition, morphological and structural characterization of Ca10(PO4)6(OH)2: XRD, FTIR, SEM, 3D SEM and solid-state NMR studies

NASA Astrophysics Data System (ADS)

Kareiva, Simonas; Klimavicius, Vytautas; Momot, Aleksandr; Kausteklis, Jonas; Prichodko, Aleksandra; Dagys, Laurynas; Ivanauskas, Feliksas; Sakirzanovas, Simas; Balevicius, Vytautas; Kareiva, Aivaras

2016-09-01

Aqueous sol-gel chemistry route based on ammonium-hydrogen phosphate as the phosphorus precursor, calcium acetate monohydrate as source of calcium ions, and 1,2-ethylendiaminetetraacetic acid (EDTA), or 1,2-diaminocyclohexanetetracetic acid (DCTA), or tartaric acid (TA), or ethylene glycol (EG), or glycerol (GL) as complexing agents have been used to prepare calcium hydroxyapatite (Ca10(PO4)6(OH)2, CHAp). The phase transformations, composition, and structural changes in the polycrystalline samples were studied by infrared spectroscopy (FTIR), X-ray powder diffraction analysis (XRD), and scanning electron microscopy (SEM). The local short-range (nano- and mezo-) scale effects in CHAp were studied using solid-state NMR spectroscopy. The spatial 3D data from the SEM images of CHAp samples obtained by TA, EG and GL sol-gel routes were recovered for the first time to our knowledge.

Sonochemical synthesis and characterization of a novel hetro-binuclear metal organic nano polymer based on picolinic acid ligand

NASA Astrophysics Data System (ADS)

Hayati, Payam; Souri, Bagher; Rezvani, Ali Reza; Morsali, Ali; Gutierrez, Angel

2017-12-01

Nanoparticles of one new lead and K coordination polymer (CP), {[Pb6(pyc)6(N3)7K].½H2O}n (1) Hpyc = picolinic acid ligand, has been synthesized by use of a sonochemical process and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR) spectroscopy and elemental analyses. The single crystal X-ray data of compound 1 imply that the Pb ion is seven coordinated. The thermal stability of compound 1 has been studied by thermogravimetric (TG) and differential scanning calorimetry (DSC). The role of temperature, reaction time and ultrasound irradiation power on the size and morphfology of the nano-structured compound obtained from 1, have been investigated. Results indicate that an increase of temperature and sonication power and a decrease in time reaction led to a decrease of particle size.

Synthesis and characterization of MOF-aminated graphite oxide composites for CO2 capture

NASA Astrophysics Data System (ADS)

Zhao, Yunxia; Ding, Huiling; Zhong, Qin

2013-11-01

A kind of metal-organic frameworks (MOF-5) and aminated graphite oxide (AGO) composites were prepared for CO2 capture to mitigate global warming. MOF-5, MOF-5/GO (composite of MOF-5 and graphite oxide) and MOF-5/AGO samples were characterized by X-ray powder diffraction (XRD), infrared spectroscopy (IR), scanning electron microscope (SEM), nitrogen adsorption as well as thermogravimetric analysis to figure out their chemistry and structure information. Three types of samples with suitable specific surface area and pore diameter were chosen to test CO2 adsorption performance and stability under humidity conditions. The results indicate that high surface area and pore volume, pore similar in size to the size of gas adsorbate, and extra reactive sites modified in the composites contributes to the high CO2 capacity. Besides, the composites involved by GO or AGO show better anti-moisture performance than the parent MOF.

Acetone Sensing Properties of a Gas Sensor Composed of Carbon Nanotubes Doped With Iron Oxide Nanopowder

PubMed Central

Tan, Qiulin; Fang, Jiahua; Liu, Wenyi; Xiong, Jijun; Zhang, Wendong

2015-01-01

Iron oxide (Fe2O3) nanopowder was prepared by a precipitation method and then mixed with different proportions of carbon nanotubes. The composite materials were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. A fabricated heater-type gas sensor was compared with a pure Fe2O3 gas sensor under the influence of acetone. The effects of the amount of doping, the sintering temperature, and the operating temperature on the response of the sensor and the response recovery time were analyzed. Experiments show that doping of carbon nanotubes with iron oxide effectively improves the response of the resulting gas sensors to acetone gas. It also reduces the operating temperature and shortens the response recovery time of the sensor. The response of the sensor in an acetone gas concentration of 80 ppm was enhanced, with good repeatability. PMID:26569253

Acetone Sensing Properties of a Gas Sensor Composed of Carbon Nanotubes Doped With Iron Oxide Nanopowder.

PubMed

Tan, Qiulin; Fang, Jiahua; Liu, Wenyi; Xiong, Jijun; Zhang, Wendong

2015-11-11

Iron oxide (Fe₂O₃) nanopowder was prepared by a precipitation method and then mixed with different proportions of carbon nanotubes. The composite materials were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. A fabricated heater-type gas sensor was compared with a pure Fe₂O₃ gas sensor under the influence of acetone. The effects of the amount of doping, the sintering temperature, and the operating temperature on the response of the sensor and the response recovery time were analyzed. Experiments show that doping of carbon nanotubes with iron oxide effectively improves the response of the resulting gas sensors to acetone gas. It also reduces the operating temperature and shortens the response recovery time of the sensor. The response of the sensor in an acetone gas concentration of 80 ppm was enhanced, with good repeatability.

Amine-functionalized magnetic mesoporous silica nanoparticles for DNA separation

NASA Astrophysics Data System (ADS)

Sheng, Wei; Wei, Wei; Li, Junjian; Qi, Xiaoliang; Zuo, Gancheng; Chen, Qi; Pan, Xihao; Dong, Wei

2016-11-01

We report a modified approach for the functionalized magnetic mesoporous silica nanoparticles (MMSN) using polymer microspheres incorporated with magnetic nanoparticles in the presence of cetyltrimethylammonium bromide (CTAB) and the core-shell magnetic silica nanoparticles (MSN). These particles were functionalized with amino groups via the addition of aminosilane directly to the particle sol. We then evaluate their DNA separation abilities and find the capacity of DNA binding significantly increased (210.22 μg/mg) compared with normal magnetic silica spheres (138.44 μg/mg) by using an ultraviolet and visible spectrophotometer (UV). The morphologies, magnetic properties, particle size, pore size, core-shell structure and Zeta potential are characterized by Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), Transmission electron microscopy (TEM), Powder X-ray diffraction (XRD), and dynamic light scattering (DLS). This work demonstrates that our MMSN own an excellent potential application in bioseparation and drug delivery.

Uniform surface modification of diatomaceous earth with amorphous manganese oxide and its adsorption characteristics for lead ions

NASA Astrophysics Data System (ADS)

Li, Song; Li, Duanyang; Su, Fei; Ren, Yuping; Qin, Gaowu

2014-10-01

A novel method to produce composite sorbent material compromising porous diatomaceous earth (DE) and surface functionalized amorphous MnO2 is reported. Via a simple in situ redox reaction over the carbonized DE powders, a uniform layer of amorphous MnO2 was anchored onto the DE surface. The hybrid adsorbent was characterized by X-ray diffraction, scanning electron microscopy, and infrared spectroscopy. The batch method has been employed to investigate the effects of surface coating on adsorption performance of DE. According to the equilibrium studies, the adsorption capacity of DE for adsorbing lead ions after MnO2 modification increased more than six times. And the adsorption of Pb2+ on the MnO2 surface is based on ion-exchange mechanism. The developed strategy presents a novel opportunity to prepare composite adsorbent materials by integrating nanocrystals with porous matrix.

Enhancement of room temperature ferromagnetism in tin oxide nanocrystal using organic solvents

NASA Astrophysics Data System (ADS)

Sakthiraj, K.; Hema, M.; Balachandra Kumar, K.

2017-10-01

The effect of organic solvents (ethanol & ethylene glycol) on the room temperature ferromagnetism in nanocrystalline tin oxide has been studied. The samples were synthesized using sol-gel method with the mixture of water & organic liquid as solvent. It is found that pristine SnO2 nanocrystal contain two different types of paramagnetic centres over their surface:(i) surface chemisorbed oxygen species and (ii) Sn interstitial & oxygen vacancy defect pair. The magnetic moment induced in the as-prepared samples is mainly contributed by the alignment of local spin moments resulting from these defects. These surface defect states are highly activated by the usage of ethylene glycol solvent rather than ethylene in tin oxide nanostructure synthesis. Powder X-ray diffraction, transmission electron microscope imaging, energy dispersive spectrometry, Fourier transformed infrared spectroscopy, UV-vis absorption spectroscopy, photoluminescence spectroscopy, vibrating sample magnetometer measurement and electron spin resonance spectroscopy were employed to characterize the nanostructured tin oxide materials.

Impurity characterization of magnesium diuranate using simultaneous TG-DTA-FTIR measurements

NASA Astrophysics Data System (ADS)

Raje, Naina; Ghonge, Darshana K.; Hemantha Rao, G. V. S.; Reddy, A. V. R.

2013-05-01

Current studies describe the application of simultaneous thermogravimetry-differential thermal analysis - evolved gas analysis techniques for the compositional characterization of magnesium diuranate (MDU) with respect to the impurities present in the matrix. The stoichiometric composition of MDU was identified as MgU2O7ṡ3H2O. Presence of carbonate and sulphate as impurities in the matrix was confirmed through the evolved gas analysis using Fourier Transformation Infrared Spectrometry detection. Carbon and magnesium hydroxide content present as impurities in magnesium diuranate have been determined quantitatively using TG and FTIR techniques and the results are in good agreement. Powder X-ray diffraction analysis of magnesium diuranate suggests the presence of magnesium hydroxide as impurity in the matrix. Also these studies confirm the formation of magnesium uranate, uranium sesquioxide and uranium dioxide above 1000 °C, due to the decomposition of magnesium diuranate.

Mechanical Grinding Preparation and Characterization of TiO2-Coated Wollastonite Composite Pigments

PubMed Central

Chen, Wanting; Liang, Yu; Hou, Xifeng; Zhang, Jing; Ding, Hao; Sun, Sijia; Cao, Hu

2018-01-01

TiO2-coated wollastonite composite pigments were prepared by the mechano-chemical grinding of wollastonite and TiO2 powder together in a wet ultrafine stirred mill. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and infrared spectra were used to investigate the microstructures and morphologies of the composite and the reaction mechanism. The results indicate that the TiO2-coated wollastonite composite pigments have similar properties to titanium dioxide pigment, showing much better properties than dry and wet mixing of wollastonite and TiO2. The hiding power of TiO2-coated wollastonite composite pigments (45% TiO2) is 17.97 g/m2, reaching 81.08% of titanium dioxide. A firm combination between wollastonite and TiO2 is obtained through a surface dehydroxylation reaction during the mechano-chemical method. PMID:29649116

Effects of Solvent Diols on the Synthesis of ZnFe2O4 Particles and Their Use as Heterogeneous Photo-Fenton Catalysts

PubMed Central

Anchieta, Chayene Gonçalves; Cancelier, Adriano; Mazutti, Marcio Antonio; Jahn, Sérgio Luiz; Kuhn, Raquel Cristine; Gündel, Andre; Chiavone-Filho, Osvaldo; Foletto, Edson Luiz

2014-01-01

A solvothermal method was used to prepare zinc ferrite spinel oxide (ZnFe2O4) using ethylene glycol and 1,4 butanediol as solvent diols, and the influence of diols on the physical properties of ZnFe2O4 particles was investigated. The produced particles were characterized by X-ray powder diffraction (XRD), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption isotherms, and the catalytic activity for the organic pollutant decomposition by heterogeneous photo-Fenton reaction was investigated. Both solvents produced particles with cubic spinel structure. Microporous and mesoporous structures were obtained when ethylene glycol and 1,4 butanediol were used as diols, respectively. A higher pore volume and surface area, as well as a higher catalytic activity for the pollutant degradation were found when 1,4 butanediol was used as solvent. PMID:28788191

Synthesis, characterisation and anion exchange properties of copper, magnesium, zinc and nickel hydroxy nitrates

NASA Astrophysics Data System (ADS)

Biswick, Timothy; Jones, William; Pacuła, Aleksandra; Serwicka, Ewa

2006-01-01

Anion exchange reactions of four structurally related hydroxy salts, Cu 2(OH) 3NO 3, Mg 2(OH) 3NO 3, Ni 2(OH) 3NO 3 and Zn 3(OH) 4(NO 3) 2 are compared and trends rationalised in terms of the strength of the covalent bond between the nitrate group and the matrix cation. Powder X-ray diffraction (PXRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and elemental analysis are used to characterise the materials. Replacement of the nitrate anions in the zinc and copper salts with benzoate anions is possible although exchange of the zinc salt is accompanied by modification of the layer structure from one where zinc is exclusively six-fold coordinated to a structure where there is both six- and four-fold zinc coordination. Magnesium and nickel hydroxy nitrates, on the other hand, hydrolyse to their respective metal hydroxides.

Preparation of C.I. Pigment 52:1 anion-pillared layered double hydroxide and the thermo- and photostability of the resulting intercalated material

NASA Astrophysics Data System (ADS)

Guo, Shengchang; Evans, David G.; Li, Dianqing

2006-05-01

Intercalation of 2-naphthalenecarboxylic acid, 4-((4-chloro-5-methyl-2-sulfophenyl) azo)-3-hydroxy-, calcium salt (1:1) (C.I. Pigment Red 52:1, also known as New Rubine S6B) into a layered double hydroxide (LDHs) host was carried out using MgAl NO3 LDHs as a precursor in an effort to improve the thermal and photo stability of the pigment. After intercalation, the powder X-ray diffraction (XRD) pattern shows that the basal spacing of the LDHs increased from 0.86 to 1.92 nm. Infrared spectra and TG DTA curves demonstrate that there are supramolecular host guest interactions. It was found that the intercalated material is more stable than the pristine pigment at high temperatures. The pigment anion-pillared LDHs also exhibit much higher photostablity to UV-light than the pristine pigment.

Preparation and characterization of 'green' hybrid clay-dye nanopigments

NASA Astrophysics Data System (ADS)

Kaya, Mehmet; Onganer, Yavuz; Tabak, Ahmet

2015-03-01

We obtained a low cost and abundant nanopigment material composed of Rhodamine B (Rh-B) organic dye compound and Unye bentonite (UB) clay from Turkey. The characterization of the nanopigment was investigated using scanning electron microscopy (SEM), particle size distribution, powder X-ray diffraction (PXRD), Fourier transformed infra-red spectroscopy (FT-IR) and thermal analysis techniques. According to the result of texture analyses, we showed that the particle size distribution (d: 0.5-mean distribution) of Rh-B/UB nanopigment material was around 100 nm diameter. It was also demonstrated that the samples had a particle size around nm diameter in SEM images. As seen in the PXRD and thermal analysis, there is a difference in basal spacing by 1.46° (2θ) and a higher mass loss by 7.80% in the temperature range 200-500 °C compared to the raw bentonite.

Construction of a novel pH-sensitive drug release system from mesoporous silica tablets coated with Eudragit

NASA Astrophysics Data System (ADS)

Xu, Yingpu; Qu, Fengyu; Wang, Yu; Lin, Huiming; Wu, Xiang; Jin, Yingxue

2011-03-01

A novel pH-sensitive drug release system has been established by coating Eudragit (Eud) on drug-loaded mesoporous silica (MS) tablets. The release rate of ibuprofen (IBU) from the MS was retarded by coating with Eudragit S-100, and the higher retardation was due to the increase of coating concentration and the coating layers. The target position of the release depended on the pH of the release medium, which was confirmed by the drug release from IBU/MS/Eud increasing rapidly with the change of medium pH from 1.2 to 7.4. This drug delivery system could prohibit irritant drug from leaking in the stomach and make it only release in the intestine. The loaded and unloaded drug samples were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), N 2 adsorption/desorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM).

Development of a novel dry powder inhalation formulation for the delivery of rivastigmine hydrogen tartrate.

PubMed

Simon, Alice; Amaro, Maria Inês; Cabral, Lucio Mendes; Healy, Anne Marie; de Sousa, Valeria Pereira

2016-03-30

The purpose of this study was to prepare engineered particles of rivastigmine hydrogen tartrate (RHT) and to characterize the physicochemical and aerodynamic properties, in comparison to a lactose carrier formulation (LCF). Microparticles were prepared from ethanol/water solutions containing RHT with and without the incorporation of L-leucine (Leu), using a spray dryer. Dry powder inhaler formulations prepared were characterized by scanning electron microscopy, powder X-ray diffraction, laser diffraction particle sizing, ATR-FTIR, differential scanning calorimetry, bulk and tapped density, dynamic vapour sorption and in vitro aerosol deposition behaviour using a next generation impactor. The smooth-surfaced spherical morphology of the spray dried microparticles was altered by adding Leu, resulting in particles becoming increasingly wrinkled with increasing Leu. Powders presented low densities. The glass transition temperature was sufficiently high (>90 °C) to suggest good stability at room temperature. As Leu content increased, spray dried powders presented lower residual solvent content, lower particle size, higher fine particle fraction (FPF<5 μm), and lower mass median aerodynamic diameter (MMAD). The LCF showed a lower FPF and higher MMAD, relative to the spray dried formulations containing more than 10% Leu. Spray dried RHT powders presented better aerodynamic properties, constituting a potential drug delivery system for oral inhalation. Copyright © 2016. Published by Elsevier B.V.

High resolution powder diffraction at HASYLAB

NASA Astrophysics Data System (ADS)

Wroblewski, Thomas; Ihringer, Jorg; Maichle, Josef

1988-04-01

HASYLAB's beamline F1 was modified for powder diffraction in a triple-axis geometry. The diffractometer consists of two independent circles for θ and 2θ motion on either side of the beam. The θ circle can be translated along its axis. This makes the instrument highly flexible for the installation of different attachments like a cryostat which was used for low temperature measurements on the new high Tc superconductors. Measurements on zeolites demonstrate the excellent resolution and signal-to-noise ratio. Novel measuring strategies concerning the use of multiple analyzers, the examination of phase transitions and anomalous dispersion are presented.

Neutron powder diffraction studies as a function of temperature of structure II hydrate formed from propane

USGS Publications Warehouse

Rawn, C.J.; Rondinone, A.J.; Chakoumakos, B.C.; Circone, S.; Stern, L.A.; Kirby, S.H.; Ishii, Y.

2003-01-01

Neutron powder diffraction data confirm that hydrate samples synthesized with propane crystallize as structure type II hydrate. The structure has been modeled using rigid-body constraints to describe C3H8 molecules located in the eight larger polyhedral cavities of a deuterated host lattice. Data were collected at 12, 40, 100, 130, 160, 190, 220, and 250 K and used to calculate the thermal expansivity from the temperature dependence of the lattice parameters. The data collected allowed for full structural refinement of atomic coordinates and the atomic-displacement parameters.

TSX-PLUS MULTI-TASKING UPGRADE FOR THE NICOLET L-11 POWDER DIFFRACTION SYSTEM.

USGS Publications Warehouse

Fitzpatrick, J.; Queen, David L.

1985-01-01

In August of 1982, a single-user, dual-translator, automated powder diffraction system was purchased by the Denver Research Institute for use on project work in the Chemical and Materials Sciences Division. Within a short period of time, the system had already become saturated with users. Scheduling conflicts arose. In view of these problems, an answer was sought in the form of hardware and software changes which would allow many users access to the system simultaneously. A low-cost, minimum impact solution was eventually found. The elements of the solution are reported.

Structure resolution by electron diffraction tomography of the complex layered iron-rich Fe-2234-type Sr{sub 5}Fe{sub 6}O{sub 15.4}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lepoittevin, Christophe, E-mail: christophe.lepoittevin@neel.cnrs.fr

2016-10-15

The crystal structure of the strontium ferrite Sr{sub 5}Fe{sub 6}O{sub 15.4}, was solved by direct methods on electron diffraction tomography data acquired on a transmission electron microscope. The refined cell parameters are a=27.4047(3) Å, b=5.48590(7) Å and c=42.7442(4) Å in Fm2m symmetry. Its structure is built up from the intergrowth sequence between a quadruple perovskite-type layer with a complex rock-salt (RS)-type block. In the latter iron atoms are found in two different environments : tetragonal pyramid and tetrahedron. The structural model was refined by Rietveld method based on the powder X-ray diffraction pattern. - Highlights: • Complex structure of Sr{submore » 5}Fe{sub 6}O{sub 15.4} solved by electron diffraction tomography. • Observed Fourier maps allow determining missing oxygen atoms in the structure. • Structural model refined from powder X-ray diffraction data. • Intergrowth between quadruple perovskite layer with double rock-salt-type layer.« less

Idealized powder diffraction patterns for cellulose polymorphs

USDA-ARS?s Scientific Manuscript database

Cellulose samples are routinely analyzed by X-ray diffraction to determine their crystal type (polymorph) and crystallinity. However, the connection is seldom made between those efforts and the crystal structures of cellulose that have been determined with synchrotron X-radiation and neutron diffrac...

Quantitative analysis of crystalline pharmaceuticals in powders and tablets by a pattern-fitting procedure using X-ray powder diffraction data.

PubMed

Yamamura, S; Momose, Y

2001-01-16

A pattern-fitting procedure for quantitative analysis of crystalline pharmaceuticals in solid dosage forms using X-ray powder diffraction data is described. This method is based on a procedure for pattern-fitting in crystal structure refinement, and observed X-ray scattering intensities were fitted to analytical expressions including some fitting parameters, i.e. scale factor, peak positions, peak widths and degree of preferred orientation of the crystallites. All fitting parameters were optimized by the non-linear least-squares procedure. Then the weight fraction of each component was determined from the optimized scale factors. In the present study, well-crystallized binary systems, zinc oxide-zinc sulfide (ZnO-ZnS) and salicylic acid-benzoic acid (SA-BA), were used as the samples. In analysis of the ZnO-ZnS system, the weight fraction of ZnO or ZnS could be determined quantitatively in the range of 5-95% in the case of both powders and tablets. In analysis of the SA-BA systems, the weight fraction of SA or BA could be determined quantitatively in the range of 20-80% in the case of both powders and tablets. Quantitative analysis applying this pattern-fitting procedure showed better reproducibility than other X-ray methods based on the linear or integral intensities of particular diffraction peaks. Analysis using this pattern-fitting procedure also has the advantage that the preferred orientation of the crystallites in solid dosage forms can be also determined in the course of quantitative analysis.