Search results for "thermal decomposition"
showing 10 items of 112 documents
Electrochemical characterization of solid state reaction kinetics using voltammetry of microparticles. Application to thermal decomposition of iron c…
2011
The voltammetry of microparticles is applied to characterize the electrocatalytic ability of solids towards selected electrochemical processes. The variation of catalytic currents under fixed electrochemical conditions permits to obtain composition/time data to be fitted with solid state kinetic models. This methodology is applied to analyze the thermal decomposition of magnesiochromite ferroan and chlorite chromian standards and a South Africa iron chromite ore on the basis of the significant catalytic effect on the electrochemical oxygen evolution reaction (OER) in aqueous alkaline media at mineral-modified graphite electrodes. Measurement of the time variation of catalytic current for OE…
Chemical Vapour Deposition of Pure Titanium Using a Heated Wire Reactor and TiI4
2017
Master's thesis Renewable Energy ENE500 - University of Agder 2017 An experimental reactor system has been optimized throughout a series of experiments for making titanium tubes from an electrically heated titanium coil filament by a chemical vapour deposition method, based on the original van Arkel-de Boer -process. The titanium is thermally decomposed on the filament from vapourized titanium tetraiodide in a method not seen in similar experiments. The small-scale reactor is built for this purpose, and the associated systems and methods are developed to maintain the optimal conditions for a continuous metal deposition. A filament current control system is made of an Arduino micro-controlle…
Experimental and Theoretical Investigations of Structural Trends for Selenium(IV) Imides and Oxides: X-ray Structure of Se3(NAd) 2
2004
The thermal decomposition of Se(NAd)(2) (Ad = 1-adamantyl) in THF was monitored by (77)Se NMR and shown to give the novel cyclic selenium imide Se(3)(NAd)(2) as one of the products. An X-ray structural determination showed that Se(3)(NAd)(2) is a puckered five-membered ring with d(Se-Se) = 2.404(1) A and |d(Se-N)| = 1.873(4) A. On the basis of (77)Se NMR data, other decomposition products include the six-membered ring Se(3)(NAd)(3), and the four-membered rings AdNSe(micro-NAd)(2)SeO and OSe(micro-NAd)(2)SeO. The energies for the cyclodimerization of E(NR)(2) and RNEO (E = S, Se; R = H, Me, (t)Bu, SiMe(3)), and the cycloaddition reactions of RNSeO with E(NR)(2), RNSO(2) with Se(NR)(2), and S…
Thermal behaviour of anhydrous, dihydrate and (2/1) ethanol forms of 1-O-α-d-glucopyranosyl-d-mannitol
1998
Abstract The melting points of anhydrous 1-O-α- d -glucopyranosyl- d -mannitol, 1-O-α- d -glucopyranosyl- d -mannitol dihydrate and a new compound, 1-O-α- d -glucopyranosyl- d -mannitol-ethanol (2/1) were determined using differential scanning calorimetry. The melting onset values were 169.2 (3), 104.3 (18) and 158.7 (9), respectively, and the melting peak values were 171.4 (5), 107.9 (15) and 160.1 (6), respectively. 1-O-α- d -glucopyranosyl- d -mannitol dihydrate and 1-O-α- d -glucopyranosyl- d -mannitol-ethanol (2/1) decompose to anhydrous form when heated at slow heating rates. According to TG-FTIR measurements, 1-O-α- d -glucopyranosyl- d -mannitol-ethanol (2/1) lost its ethanol in the…
Synthesis and Crystal Structure of Ln3(OH)(CrO4)4 · 3.5H2O (Ln = Pr, Nd) and Ln2(OH)2(CrO4)2 (Ln = Tb, Gd): Thermal Behavior and Infrared Spectra of …
1993
Abstract Crystal structures of Ln 2 (OH) 2 (CrO 4 ) 2 ( Ln = Gd, Tb) and Ln 3 (OH)(CrO 4 ) 4 · 3.5H 2 O ( Ln = Pr, Nd) were determined by a conventional single-crystal X-ray diffraction technique. Crystals of Ln 2 (OH) 2 (CrO 4 ) 2 ( Ln = Gd, Tb) are monoclinic, space group P 2 1 / c (no. 14) with lattice parameters a = 8.2454(4) A, b = 11.3834(5) A, C = 12.1420(8) A, and β = 136,590(5)°, Z = 4, D x = 4.92 mg · m -3 for Gd 2 (OH) 2 (CrO 4 ) 2 and a = 8.214(1) A, b = 11.348(1) A, c = 12.094(2) A, and β = 136.59(1)°, Z = 4, D x = 5.01 Mg · m -3 for Tb 2 (OH) 2 (CrO 4 ) 2 . Crystals of Ln 3 (OH)(CrO 4 )) 4 · 3.5H 2 O ( Ln = Pr, Nd) are monoclinic, space group C 2/ c (No. 15) with lattice param…
ChemInform Abstract: Evidence for the Formation of 1,3- and 1,4-Dehydrobenzenes in the Thermal Decomposition of Diaryliodonium-carboxylates.
1987
Abstract Abstract: Generation of m- and p-benzynes in decomposition of diaryliodonium- 3- and 4-carboxylates is demonstrated by three-phase method.
Synthesis and characterization of novel organic–inorganic hybrid block copolymers
2004
Novel organic–inorganic hybrid block copolymers based on poly(methylsilsesquioxanes) (PMSSQs) have been synthesized. Two routes to functionalized PMSSQs are presented and from both atom transfer radical polymerization of methylmethacrylate could be performed. Copolymers with different block ratios have been polymerized and were characterized. In particular, thermal properties were investigated by TGA and the promising thermal decomposition behaviour makes the copolymers potential candidates as pore generators in future nanoporous materials. Additionally, these copolymers were analysed as surface coatings of regular PMMA. Contact angle measurements proved the dramatic effect on the surface p…
Influence of diamagnetic impurity on mid‐IR absorption in antiferromagnetic insulator NiO
2005
-1 was studied in polycrystalline Ni c Mg 1-c O solid solutions with c=0.99, 0.98, 0.97, 0.95, 0.90, 0.80, 0.70 and 0.60. The composition and temperature dependences of the absorption suggest that the band has magnetic origin re- lated to simultaneous excitation of two-magnons at the Brillouin-zone boundary and one phonon. -1 in polycrystalline NicMg1-cO solid solutions. Polycrystalline solid solutions NicMg1-cO (c=0.99, 0.98, 0.97, 0.95, 0.90, 0.80, 0.70 and 0.60) were prepared using ceramic technology from the appropriate amounts of aqueous solutions of Mg(NO3)2·6H2O and Ni(NO3)2·6H2O salts, which were mixed and slowly evaporated. The remaining dry 'flakes' were heated up to 500-600 oC to…
Nachweis des di-2-cyanoisopropylperoxides bei der zersetzung von azoisobuttersäuredinitril in gegenwart von sauerstoff
1970
Das Di-2-cyanoisopropylperoxid entsteht in etwa 5-proz. Ausbeute bei der Zersetzung von Azoisobuttersaredinitril unter Sauerstoff in Isobutyronitril als Losungsmittel. Thermisch zerfallt das Peroxid est oberhalb von 120°C mit mesbarer Geschwindigkeit in einer Reaktion erster Ordnung. Die Aktivierungsenergie, in Cumol als Losungsmittel, wurde zu 37,9 kcal · mol−1 bestimmt. Werte fur die Zerfallskonstante bei 140°C sind in Cumol 0,057 h−1, in tert-Butylbenzol 0,073 h−1, in Chlorbenzol 0,18 h−1 und in o-Dichlorbenzol 0,23 h−1. Di-2-cyanoisopropylperoxide is formed when azobisisobutyronitrile is decomposed under oxygen in isobutyronitrile as a solvent. The yield amounts to ca. 5%. Thermal decom…
Synthesis of MoO3 Nanostructures and Their Facile Conversion to MoS2 Fullerenes and Nanotubes.
2007
The fast thermolysis of ammonium molybdate leads to a mixture of MoO3 and Mo5.3O14.5(OH)2.8(H2O)1.36 with spherical and rod-like morphologies. The oxide mixture can be converted in quantitative yield to inorganic fullerene-type (IF) MoS2 and MoS2 nanotubes (NT) by H2S reduction using a facile and quick procedure. The products were studied by X-Ray Diffraction (XRD) and by Transmission Electron Microscopy (TEM). TEM analysis reveals that the spherical and rod-like morphology of the oxide precursor is preserved during the H2S treatment.