Search results for "Thermal Analysis"

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…

Reactivity and Structural Defects in Glaserite-Type Iron-Vanadates

2018

Synthesis and characterization of diatomaceous earth chemically modified with γ-aminopropyltrimethoxysilane

2003

A stationary phase for thin-layer chromatography has been prepared by bonding purified diatomaceous earth (rich in silica) with γ-aminopropyltrimethoxysilane. The phase has been characterized by elemental analysis, measurement of the specific surface area, IR spectroscopy, thermal analysis, and chromatographic testing.

New insights on the thermal analysis of low moisture composite foods.

2014

Abstract Low moisture baked products were investigated with a view to characterising the effect of both formulation and humidity on their physical stability. At the end of the baking process, the samples were in the amorphous state as a result of starch gelatinization and sugar melting. Their thermal properties were analyzed with differential scanning calorimetry and their glass transitions were studied. The DSC thermograms were thoroughly studied through a Gaussian deconvolution of the first derivative of their heat flow. This approach evidenced a multiple phase behavior with different glass transitions in composite systems. They were associated with either a polymer-rich phase and/or a pl…

A Comprehensive Thermogravimetric Analysis Multifaceted Method for the Exact Determination of the Composition of Multifunctional Metal‐Organic Framew…

2020

Thermogravimetric analysis (TGA) has been widely used as a tool to characterise the composition of materials such as Metal-Organic Frameworks (MOFs). However, given their multifunctionality and structural complexity, examples of detailed methodologies for the exact calculation of the composition of complex MOF structures and MOF composites are lacking in the literature. Herein, we introduce a new straightforward methodology – based on the experimental ratio between the mass of a structure and its residue – for the exact calculation of the composition of almost any MOF material. We provide a detailed guide for the application of our methodology to different MOF materials, including MOFs in w…

Improving thermoelectric performance of TiNiSn by mixing MnNiSb in the half-Heusler structure

2016

The thermoelectric properties of n type semiconductor, TiNiSn is optimized by partial substitution with metallic, MnNiSb in the half Heusler structure. Herein, we study the transport properties and intrinsic phase separation in the system. The Ti1-xMnxNiSn1-xSbx alloys were prepared by arc-melting and were annealed at temperatures obtained from differential thermal analysis and differential scanning calorimetry results. The phases were characterized using powder X-ray diffraction patterns, energy dispersive X-ray spectroscopy, and differential scanning calorimetry. After annealing the majority phase was TiNiSn with some Ni rich sites and the minority phases was majorly Ti6Sn5, Sn, and MnSn2…

Heterobimetallic MOFs containing tetrathiocyanometallate building blocks: Pressure-induced spin crossover in the porous {Fe II(pz)[Pd II(SCN) 4]} 3D …

2012

Here we describe the synthesis, structure, and magnetic properties of two related coordination polymers made up of self-assembling Fe(II) ions, pyrazine (pz), and the tetrathiocyanopalladate anion. Compound {Fe(MeOH) 2[Pd(SCN) 4]}·pz (1a) is a two-dimensional coordination polymer where the Fe(II) ions are equatorially coordinated by the nitrogen atoms of four [Pd(SCN) 4] 2- anions, each of which connects four Fe(II) ions, forming corrugated layers {Fe[Pd(SCN) 4]} ∞. The coordination sphere of Fe(II) is completed by the oxygen atoms of two CH 3OH molecules. The layers stack one on top of each other in such a way that the included pz molecule establishes strong hydrogen bonds with the coordin…

Thermal modelling of the ATHENA X-IFU filters

2018

Copyright 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. The X-IFU instrument of the ATHENA mission requires a set of thermal filters to reduce the photon shot noise onto its cryogenic detector and to protect it from molecular contamination. A set of five filters, operating at different nominal temperatures corresponding to the cryostat shield temperatures, is currently baselined. The knowledge of the actual filter temperature profi…

Three anhydrous forms and a dihydrate form of quifenadine hydrochloride: a structural study of the thermodynamic stability and dehydration mechanism

2015

Crystal structures of dihydrate (DH) and three anhydrous forms (A, B and C) of quifenadine (1-azabicyclo[2.2.2]oct-8-yl-diphenyl-methanol) hydrochloride are presented, and crystal structure information is used to explain and rationalize the relative stability of polymorphs and observed phase transformations. The dehydration mechanism of the hydrate is provided by interpreting the results obtained in studies of crystal structures, dehydration kinetics and thermal analysis. Structural analysis is used to explain the observed relative stability of the anhydrous phases and the hydrate. The crystal structures have been determined either from single crystal (form DH) or from powder diffraction da…

Thermal analysis applied to the characterization of degradation in soil of polylactide: I. Calorimetric and viscoelastic analyses

2010

[EN] An accelerated soil burial test has been performed on a commercial polylactide (PLA) for simulating non-controlled disposal. Degradation in soil promotes physical and chemical changes in polylactide properties, which can be characterized by Thermal Analysis techniques. Physical changes occurred in polylactide due to the degradation in soil were evaluated by correlating their calorimetric and visco-elastic properties. It is highly remarkable that each calorimetric scan offers specific and enlightening information. Degradation in soil affects the polylactide chains reorganization. A multimodal melting behavior is observed for buried PLA, degradation in soil also promotes the enlarging th…