Characterization of modified iron catalysts by X-ray diffraction, infrared spectroscopy, magnetic susceptibility and thermogravimetric analysis

2004 ◽  
Vol 58 (20) ◽  
pp. 2447-2450 ◽  
Author(s):  
Serbia M Rodulfo-Baechler ◽  
Sergio L González-Cortés ◽  
José Orozco ◽  
Vicente Sagredo ◽  
Bernardo Fontal ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Iron Catalysts ◽  
X Ray Diffraction ◽  
X Ray

Synthesis and Characterization of Polyaniline Copolymer

2012 ◽  
Vol 217-219 ◽  
pp. 551-554
Author(s):  
Ting Xi Li ◽  
Yu Hua Zhao ◽  
Qian Li ◽  
Cheng Qian Yuan ◽  
Quan Liang Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
The Difference ◽  
Thermal Stability Of

Abstract. Polyaniline (PANI) and p-phenylenediamine (p-PDA)-aniline copolymer were prepared via a same microemulsion method. The structures of the PANI and p-PDA-aniline copolymer were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis（TGA）. The results revealed the difference of synthesis and characterization between PANI and p-PDA-aniline copolymer. It was shown that structure of the copolymer is almost similar to that of PANI, but the p-PDA-aniline copolymer has a better crystallization than PANI, and the thermal stability of the copolymer is higher than that of pure PANI.

Synthesis and Characterization of Novel Organomodified Nanoclays for Application in Dental Materials

2019 ◽  
Vol >15 (5) ◽  
pp. 512-524 ◽  
Author(s):  
Alexandros K. Nikolaidis ◽  
Elisabeth A. Koulaouzidou ◽  
Dimitris S. Achilias
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Fourier Transform Infrared Spectroscopy ◽  
Quaternary Ammonium ◽  
Fourier Transform Infrared ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray

Background: Nanoclays incorporated in dental resins have been previously investigated. However, limited reports are associated with nanoclays that exhibit high functionality. Objective: The aim of this study was the targeted synthesis and characterization of organomodified nanoclays with methacrylic groups suitable for incorporation in dental nanocomposite resins. Methods: Quaternary ammonium methacrylates were synthesized and characterized by means of proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy. Consequently, they were inserted into the interlayer space of nanoclay through a cation exchange reaction, while silane was also used for simultaneous surface modification. The produced organomodified nanoclays were characterized by means of X-ray diffraction, Fourier-transform infrared spectroscopy and thermogravimetric analysis. Results: Fourier-transform infrared spectra confirmed the successful synthesis of the quaternary ammonium methacrylates. X-ray diffraction analysis showed that organoclays exhibited higher d001- values (up to 1.78 nm) compared to raw nanoclay (1.37 nm), indicating an accomplished intercalation in each case. X-ray diffraction spectra mainly disclosed the presence of methacrylic functional groups in all nanoclays. Thermogravimetric analysis curves verified the different thermal stability of organoclays due to the diversity of their organic modifiers. Conclusion: The experimental results showed that nanoclay was successfully modified with ammonium methacrylates and silane. Τhe combination of X-ray diffraction and thermogravimetric analysis data revealed a high degree of intercalation and methacrylated organic loading as well. These phenomena may favor a good dispersion and high polymerization degree of nanoclays with dental resin monomers, rendering them potentially useful materials for the development of advanced dental nanocomposites resins.

scholarly journals Valorization of Byproducts of Hemp Multipurpose Crop: Short Non-Aligned Bast Fibers as a Source of Nanocellulose

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4723
Author(s):  
Sara Dalle Vacche ◽  
Vijayaletchumy Karunakaran ◽  
Alessia Patrucco ◽  
Marina Zoccola ◽  
Loreleï Douard ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Cannabis Sativa ◽  
Crystallinity Index ◽  
Residual Lignin ◽  
Chemical Pretreatment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bast Fibers ◽  
Seed Maturity

Nanocellulose was extracted from short bast fibers, from hemp (Cannabis sativa L.) plants harvested at seed maturity, non-retted, and mechanically decorticated in a defibering apparatus, giving non-aligned fibers. A chemical pretreatment with NaOH and HCl allowed the removal of most of the non-cellulosic components of the fibers. No bleaching was performed. The chemically pretreated fibers were then refined in a beater and treated with a cellulase enzyme, followed by mechanical defibrillation in an ultrafine friction grinder. The fibers were characterized by microscopy, infrared spectroscopy, thermogravimetric analysis and X-ray diffraction after each step of the process to understand the evolution of their morphology and composition. The obtained nanocellulose suspension was composed of short nanofibrils with widths of 5–12 nm, stacks of nanofibrils with widths of 20–200 nm, and some larger fibers. The crystallinity index was found to increase from 74% for the raw fibers to 80% for the nanocellulose. The nanocellulose retained a yellowish color, indicating the presence of some residual lignin. The properties of the nanopaper prepared with the hemp nanocellulose were similar to those of nanopapers prepared with wood pulp-derived rod-like nanofibrils.

scholarly journals Coordination Assemblies of Zn(II) Coordination Polymers: Positional Isomeric Effect and Optical Properties

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 664 ◽  
Author(s):  
Chang-Jie Liu ◽  
Tong-Tong Zhang ◽  
Wei-Dong Li ◽  
Yuan-Yuan Wang ◽  
Shui-Sheng Chen
Keyword(s):  
Optical Properties ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Quantum Yield ◽  
Coordination Polymers ◽  
Square Lattice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Ligands ◽  
Isomeric Effect

Two Zn(II) coordination polymers (CPs) [Zn(L)(pphda)] (1) and [Zn(L)(ophda)]·H2O (2) were prepared by reactions of ZnSO4·7H2O based on the N-donor 1,4-di(1H-imidazol-4-yl)benzene (L) ligand and two flexible carboxylic acids isomers of 1,4-phenylenediacetic acid (H2pphda) and 1,2-phenylenediacetic acid (H2ophda) as mixed ligands, respectively. Structures of CPs 1 and 2 were characterized by elemental analysis, Infrared spectroscopy (IR), thermogravimetric analysis and single-crystal X-ray diffraction. The CP 1 is a fourfold interpenetrating 66-diamond (dia) architecture, while 2 is a 2D (4, 4) square lattice (sql) layer based on the Zn2(cis-1,2-ophda2−)2 binuclear Zn(II) subunits. The luminescent property, including luminescence lifetime and quantum yield (QY), have been investigated for CPs 1 and 2.

scholarly journals Effects of strain on La0.67-x Prx Ca0.33 MnO3, LaMn1-x Cox O3 and LaMn1-x Nix O3 magnetite samples

DYNA ◽  
2019 ◽  
Vol 86 (211) ◽  
pp. 278-287
Author(s):  
Javier Alberto Olarte Torres ◽  
María Cristina Cifuentes Arcila ◽  
Harvey Andrés Suárez Moreno
Keyword(s):  
Compressive Strength ◽  
Magnetic Susceptibility ◽  
Sol Gel ◽  
Morphological Characterization ◽  
Electric Resistivity ◽  
The Other ◽  
X Ray Diffraction ◽  
Metal Insulator ◽  
X Ray

This paper presents the results obtained from the synthesis and morphological characterization of different magnetite samples:  La0.67-x Prx Ca0.33 MnO3.LaMn1-x Cox O3 and LaMn1-x Nix O3 at 0.13 ≤ 𝑥𝑥 ≤ 0.67 produced by a solid-state reaction mechanism and 𝐿𝐿𝐿𝐿𝑀𝑀𝑀𝑀1−𝑥𝑥(𝐶𝐶𝐶𝐶/𝑁𝑁𝑁𝑁)𝑥𝑥𝑂𝑂3 at 0.0 ≤ 𝑥𝑥 ≤ 0.5 produced by the sol-gel method. These samples were characterized using X-ray diffraction spectroscopy and by measuring electric resistivity and magnetic susceptibility which were carried out as a function of temperature. Notably, the effects of strain and compressive strength on the lattices of magnetite samples were highly dependent on the concentration of 𝑃𝑃𝑟𝑟, 𝐶𝐶𝐶𝐶, and 𝑁𝑁𝑁𝑁. Moreover, the transition temperatures of metal-insulator and ferromagnetic-paramagnetic phases also largely depend on these strength effects, e.g., at higher concentrations of 𝑃𝑃𝑟𝑟, effects of increased strain strength were observed, relocating the shifts of ferromagnetic-paramagnetic transitions to lower temperatures. On the other hand, effects of increased compressive strength were observed at higher concentrations of 𝑁𝑁𝑁𝑁 and 𝐶𝐶𝐶𝐶, relocating the shifts of ferromagnetic-paramagnetic and metal-insulator transitions to higher temperatures.

Stability of sodalite relative to nepheline in NaCl–H2O brines at 750 °C: Implications for hydrothermal formation of sodalite

2020 ◽  
Vol 58 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Jonathan B. Schneider ◽  
David M. Jenkins
Keyword(s):  
Infrared Spectroscopy ◽  
Constant Temperature ◽  
Molar Ratio ◽  
Standard State ◽  
X Ray Diffraction ◽  
Cage Structure ◽  
X Ray ◽  
Brine Concentration

ABSTRACT Formation of the feldspathoid sodalite (Na6Al6Si6O24·2NaCl) by reaction of nepheline (NaAlSiO4) with NaCl-bearing brines was investigated at 3 and 6 kbar and at a constant temperature of 750 °C to determine the brine concentration at which sodalite forms with variation in pressure. The reaction boundary was located by reaction-reversal experiments in the system NaAlSiO4–NaCl–H2O at a brine concentration of 0.16 ± 0.08 XNaCl [= molar ratio NaCl/(NaCl + H2O)] at 3 kbar and at a brine concentration of 0.35 ± 0.03 XNaCl at 6 kbar. Characterization of the sodalite using both X-ray diffraction and infrared spectroscopy after treatment in these brines indicated no obvious evidence of water or hydroxyl incorporation into the cage structure of sodalite. The data from this study were combined with earlier results by Wellman (1970) and Sharp et al. (1989) at lower (1–1.5 kbar) and higher (7–8 kbar) pressures, respectively, on sodalite formation from nepheline and NaCl which models as a concave-down curve in XNaCl – P space. In general, sodalite buffers the concentration of neutral aqueous NaCl° in the brine to relatively low values at P < 4 kbar, but NaCl° increases rapidly at higher pressures. Thermochemical modeling of these data was done to determine the activity of the aqueous NaCl° relative to a 1 molal (m) standard state, demonstrating very low activities (<0.2 m, or 1.2 wt.%) of NaCl° at 3 kbar and lower, but rising to relatively high activities (>20 m, or 54 wt.%) of NaCl° at 6 kbar or higher. The results from this study place constraints on the concentration of NaCl° in brines coexisting with nepheline and sodalite and, because of the relative insensitivity of this reaction to temperature, can provide a convenient geobarometer for those localities where the fluid compositions that formed nepheline and sodalite can be determined independently.

Characterization of a new Ca–Cd hydroxide hydrothermally synthesized and its implications for cement isolation of Cd

1998 ◽  
Vol 13 (1) ◽  
pp. 16-21 ◽  
Author(s):  
S. Gñni ◽  
A. Macías ◽  
J. Madrid ◽  
J. M. Díez
Keyword(s):  
Infrared Spectroscopy ◽  
Pore Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Predominant Species ◽  
Solubility Constant ◽  
Tg And Dtg ◽  
Low Solubility ◽  
Mechanism Of The Reaction

Mixtures of CaO–CdO (1 : 1) were hydrothermally treated in a pressure reactor at 200 °C and 200 psi of pressure during a period of 16 h. The evolution of the reaction was followed by x-ray diffraction (XRD), infrared spectroscopy (IR), and thermogravimetric (TG and DTG) analysis. Also, the composition of the filtered solutions was analyzed to determine the mechanism of the reaction as well as the thermodynamic solubility constant of the new compound formed. The results show that CaO and CdO react, giving rise to a new CaCd(OH)4 hydroxide whose thermodynamic solubility constant, 1.5 ± 0.4 × 10−11 M2, is six orders of magnitude lower than those of both Ca(OH) 2 and β–Cd(OH) 2. This low solubility constant justifies the Cd2+ concentration measured in the pore solution of cement matrices used to immobilize cadmium containing wastes. The mechanism of the reaction proposed is via dissolution of both Ca(OH) 2 and β–Cd(OH)2, Ca2+ and being the predominant species in solution.

Preparation and characterization of poly(tetramethyl-p-phenylenediamine)/clay hybrids via intercalative polymerization

2003 ◽  
Vol 18 (2) ◽  
pp. 482-486 ◽  
Author(s):  
Guangming Chen ◽  
Nobuo Iyi ◽  
Taketoshi Fujita
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Thermal Behavior ◽  
Fourier Transform Infrared Spectroscopy ◽  
Interlayer Space ◽  
X Ray Diffraction ◽  
X Ray ◽  
Noncovalent Bonding ◽  
Intercalative Polymerization

New noncovalent bonding polymer/clay hybrids were prepared, including the polymer poly(tetramethyl-p-phenylenediamine) (poly-TMPD). Polymerization occurred in the interlayer space of clay mineral successively after intercalation of monomers. Two types of clay minerals with different surface properties—a hydrophilic lithium fluorotaeniolite (TN) and four kinds of organophilic fluorotaeniolites (org-TNs)—were used as the hosts. Powder x-ray diffraction results showed an increase of 0.7–1.0 nm in the basal spacings, indicating the formation of poly–TMPD in the interlayer space of the hosts. Intercalative polymerization was also supported by Fourier transform infrared spectroscopy. The orientation of the poly-TMPD and thermal behavior were also discussed.

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