Synthesis, crystal structure, and properties of energetic copper(II) compound based on 3,5-dinitrobenzoic acid and imidazole

2021 ◽  
Vol 19 (4) ◽  
pp. 295-304
Author(s):  
Bi-Dong Wu ◽  
Da-Wei Ren ◽  
Zhi-min Li ◽  
Jing-Yu Wang ◽  
Chong-wei An ◽  
...  
Keyword(s):  
Isothermal Kinetics ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Kinetics Parameters ◽  
Ftir Characterization ◽  
Kissinger’S Method ◽  
Potential Applications ◽  
Solid Rocket ◽  
Decomposition Behavior ◽  
Friction Sensitivity

Energetic copper(II) compound was synthesized based on 3,5-dinitrobenzoic acid (HDNBA) and imidazole (IMI), and characterized by elemental analysis and FTIR characterization. Single-crystal X-ray diffraction analysis revealed that [Cu(IMI)2(DNBA)2] (1) belongs to monoclinic, pertains to P21/c space group, β= 96.195(2) and Dc= 1.742 g cm–3. Cu(II) ion was coordinated to a plane tetragon, by two oxygen atoms and two nitrogen atoms from different DNBA ions and IMI ligands, which of them present typical monodentate coordination mode. Differential scanning calorimetry (DSC) was applied to assess the thermal decomposition behavior of 1. The non-isothermal kinetics parameters were calculated by the Kissinger’s method, Ozawa’s method and Starink’s method, respectively. Impact sensitivity and friction Sensitivity were also determined by standard method. In the end, the catalytic effects on the decomposition of ammonium perchlorate (AP), HMX and RDX of 1 were studied by DSC. All results supported the potential applications of the energetic complex 1 as additive of solid rocket propellant.

Crystallization Kinetics of β-Spodumene/Cordierite-Based Glass-Ceramics

2016 ◽  
Vol 881 ◽  
pp. 83-88 ◽  
Author(s):  
Rafael Bianchini Nuernberg ◽  
Oscar Rubem Klegues Montedo
Keyword(s):  
Crystallization Kinetics ◽  
Glass Ceramics ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Kinetics Parameters ◽  
Crystalline Phases ◽  
Cordierite Glass ◽  
Thermal And Electrical Properties ◽  
Kinetics Of

This work aims to investigate the crystallization kinetics of β-spodumene/cordierite glass-ceramics. Thus, three glasses with compositions based predominantly on cordierite (C), β-spodumene (L) and in a molar ratio 1:1 of both phases (CL) were prepared. The kinetics parameters such as activation energy for crystallization (ranging from 160 to 358 kJ/mol) and Avrami exponent (ranging from 1.4 to 10.7) were determined by means of non-isothermal methods using differential scanning calorimetry (DSC). Additionally, the samples were crystalized according to DSC analyses and characterized by using x-ray diffraction (XRD). The main detected crystalline phases were β-spodumene to the glass L, cordierite to the glass C and β-quartz, mulite and spinel to the glass CL. Considering the thermal and electrical properties of these crystalline phases, these glass-ceramics have potential use for LTCC (Low Thermal Co-fired Ceramics) applications.

scholarly journals Doping induced dielectric anomaly below the Curie temperature in molecular ferroelectric diisopropylammonium bromide

2018 ◽  
Vol 5 (11) ◽  
pp. 181397 ◽  
Author(s):  
Kaige Gao ◽  
Binbin Zhang ◽  
Yunqing Cao ◽  
Xiaobing Chen
Keyword(s):  
Point Defects ◽  
Domain Walls ◽  
Ferroelectric Domain ◽  
Dielectric Anomaly ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Potential Applications ◽  
Structure Phase Transition

A dielectric anomaly induced by doping has been observed at about 340 K in chlorine-doped diisopropylammonium bromide. The dielectric anomaly has a switchable behaviour, which indicates potential applications on switches and sensors. Temperature-dependent Raman spectrum, X-ray diffraction and differential scanning calorimetry do not show any anomaly around the dielectric anomaly temperature, which prove that the dielectric anomaly does not come from structure phase transition and has no specific heat variety. It is assumed that this dielectric anomaly can be attributed to the freezing of ferroelectric domain walls induced by the pinning of point defects.

Synthesis, crystal structure, and thermal properties of Ni(NH3)4(AFT)2

2020 ◽  
pp. 174751982093947
Author(s):  
Shu-han Wei ◽  
Xiao Ma ◽  
Zi-mei Ding ◽  
Kang-zhen Xu ◽  
Hong-xu Gao ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Peak Temperature ◽  
Isothermal Kinetics ◽  
Scanning Calorimetry ◽  
Orthorhombic Crystal ◽  
Kinetics Parameters ◽  
Stability Parameters ◽  
Exothermic Decomposition

Ni(NH3)4(AFT)2 [NiC6H16N18O2, AFT = 4-amino-3-(5-tetrazolate)furazan] is synthesized and characterized by elemental analysis and Fourier-transform infrared spectroscopy for the first time. X-ray diffraction measurements are used to determine the crystal structure of compound 1. The results demonstrate that compound 1 crystallized in the orthorhombic crystal system. The nickel(II) ion is six-coordinated by N atoms from two AFT-ligands and four NH3 molecules. Its thermal properties are investigated by differential scanning calorimetry and thermogravimetry-derivative thermogravimetry methods, with the results demonstrating that the differential scanning calorimetry curve exhibits two endothermic and one exothermic processes. The endothermic processes are in the range of 130–510 °C with a peak temperature of 188 °C. The temperature from 230 to 400 °C is the exothermic process in which the peak temperature is 314.58 °C. In addition, Kissinger’s and Ozawa-Doyle’s methods are used for calculating the non-isothermal kinetics parameters. Moreover, the apparent activation energy ( E), safety, and thermal stability parameters ( TSADT, TTIT, Tb) for Ni(NH3)4(AFT)2 are calculated. In addition, the calculated thermodynamic functions ( ∆S≠, ∆H≠, and ∆G≠) for the exothermic decomposition process of Ni(NH3)4(AFT)2 are 55.07 J mol−1 K−1, 196.18 kJ mol−1, and 164.90 kJ mol−1, respectively.

scholarly journals Nano-CL-20/HMX Cocrystal Explosive for Significantly Reduced Mechanical Sensitivity

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Chongwei An ◽  
Hequn Li ◽  
Baoyun Ye ◽  
Jingyu Wang
Keyword(s):  
Spray Drying ◽  
Raw Materials ◽  
Drop Height ◽  
Drying Method ◽  
X Ray Diffraction ◽  
Mechanical Sensitivity ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Friction Sensitivity ◽  
Scanning Electron

Spray drying method was used to prepare cocrystals of hexanitrohexaazaisowurtzitane (CL-20) and cyclotetramethylene tetranitramine (HMX). Raw materials and cocrystals were characterized using scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, Raman spectroscopy, and Fourier transform infrared spectroscopy. Impact and friction sensitivity of cocrystals were tested and analyzed. Results show that, after preparation by spray drying method, microparticles were spherical in shape and 0.5–5 µm in size. Particles formed aggregates of numerous tiny plate-like cocrystals, whereas CL-20/HMX cocrystals had thicknesses of below 100 nm. Cocrystals were formed by C–H⋯O bonding between –NO2 (CL-20) and –CH2– (HMX). Nanococrystal explosives exhibited drop height of 47.3 cm, and friction demonstrated explosion probability of 64%. Compared with raw HMX, cocrystals displayed significantly reduced mechanical sensitivity.

Synthesis and Liquid Crystalline Properties of New Chiral Monomers and Polysiloxanes

2013 ◽  
Vol 815 ◽  
pp. 747-751
Author(s):  
Jian She Hu ◽  
Yi Nan Liu ◽  
Ya Ting Song ◽  
Di Wang
Keyword(s):  
Liquid Crystalline ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Cholesteric Phase ◽  
Crystalline Materials ◽  
H Nmr ◽  
Structure Property Relationships ◽  
Potential Applications ◽  
Liquid Crystalline Materials

To study the structure-property relationships of new chiral liquid crystalline materials based on menthol and explore their potential applications, a monomer 4-(4-allyloxybenzoyloxy) phenyl-4-menthyl-oxyacetyloxybiphenyl-4-carboxylate (LCM) and the corresponding homopolymer (LCP) were synthesized. The chemical structure was characterized by FT-IR and 1H NMR. The liquid crystalline properties were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction. The monomer LCM formed a cholesteric phase when a flexible linkage chain was inserted between the mesogenic core and the terminal menthyl groups by reducing the steric effect. The homopolymer LCP exhibited a batonnet texture of a smectic A phase.

scholarly journals Microstructure and Thermomechanical Characterization of Fe-28Mn-6Si-5Cr Shape Memory Alloy

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 649
Author(s):  
Antonio Collazo ◽  
Raúl Figueroa ◽  
Carmen Mariño-Martínez ◽  
Carmen Pérez
Keyword(s):  
Shape Memory ◽  
Thermal Activation ◽  
Tensile Tests ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Potential Applications ◽  
Ε Martensite ◽  
Microscopy Techniques ◽  
Activation Cycle

Iron-based shape memory alloys (SMAs) have been widely studied during the last years, producing new formulations with potential applications in civil engineering. In the present paper, the microstructure and the thermomechanical behavior of the Fe-28Mn-6Si-5Cr memory alloy has been investigated. At room temperature, the presence of ε-martensite and γ-austenite was confirmed using optical and electron microscopy techniques. The martensitic transformation temperatures (As, Af, Ms, and Mf) were determined by differential scanning calorimetry, together with an X-ray diffraction technique. The use of these techniques also confirmed that this transformation is not totally reversible, depending on the strain degree and the number of thermal cycles. From the kinetics study of the ε → γ transformation, the isoconversion curves (transformation degree versus time) were built, which provided the information required to optimize the thermal activation cycle. Tensile tests were performed to characterize the mechanical properties of the studied alloy. These kinds of tests were also performed to assess the shape memory effect, getting a recovery stress of 140 MPa, after a 7.6% pre-strain and a thermal activation up to 160 °C.

scholarly journals Preparation of Co Nanocrystallites by Solvothermal Process and Its Catalytic Activity on the Thermal Decomposition of Ammonium Perchlorate

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Shusen Zhao ◽  
Dongxu Ma
Keyword(s):  
Thermal Decomposition ◽  
Catalytic Activity ◽  
Ammonium Perchlorate ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Polyol Medium ◽  
Decomposition Behavior

Nanometer cobalt ferrite (Co) was synthesized by polyol-medium solvothermal method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). Further, the catalytic activity and kinetic parameters of Co nanocrystallites on the thermal decomposition behavior of ammonium perchlorate (AP) have been investigated by thermogravimetry and differential scanning calorimetry analysis (TG-DSC). The results imply that the catalytic performance of Co nanocrystallites is significant and the decrease in the activation energy and the increase in the rate constant for AP further confirm the enhancement in catalytic activity of Co nanocrystallites. A mechanism based on an proton transfer process has also been proposed for AP in the presence of Co nanocrystallites.

Synthesis and Characterization of Nanocrystalline Barium–Samarium Titanate

2016 ◽  
Vol 35 (5) ◽  
pp. 499-505 ◽  
Author(s):  
M. M. Hessien ◽  
Nader El-Bagoury ◽  
M. H. H. Mahmoud ◽  
Osama M. Hemeda
Keyword(s):  
Annealing Temperature ◽  
Crystalline Size ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Analysis Measurement ◽  
Lower Annealing Temperature ◽  
Precursor Route ◽  
Decomposition Behavior ◽  
Dominant Structure

AbstractBarium–samarium titanate nanopowder (Ba0.85 Sm0.1TiO3) was synthesized through tartrate precursor route. The effect of annealing temperature on the formation, crystalline size, morphology and magnetic properties was systematically studied. The annealing temperature was varied from 600°C to 1,100°C. Thermal analysis measurement (TG-DSC, thermogravimetry-differential scanning calorimetry) was carried out on the precursor to characterize the thermal decomposition behavior. The results showed that the precursor of Ba–Sm–Ti mixture decomposed thermally in multistep weight loss up to about 480°C and perovskite Ba0.85Sm0.1TiO3 started to form at ~520°C. X-ray diffraction and Fourier transform infrared (FTIR) spectroscopic measurements showed that the synthesized Ba0.85Sm0.1TiO3 has a tetragonal dominant structure with the presence of intermediate SmTi2O3 at lower annealing temperature. The ratio of SmTi2O3 was decreased and completely disappeared at higher annealing temperatures. The tetragonality, the theoretical density and the crystalline size were increased by increasing annealing temperature. The crystalline size is still in nano-range of 12.4–19.9 nm even after annealing at 1,100°C. The morphology of the produced sample transferred from nano-cubes to nano-whisker to nano-mace (nano-aggregates) with the increase of annealing temperature.

scholarly journals The Effect of Alkali Roasting Pretreatment on Nickel Extraction from Limonite Ore by Using Dissolved SO2-Air

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 701
Author(s):  
Winny Wulandari ◽  
Meiyer Marthen Kinda ◽  
Rahmaditha Murida ◽  
Tjokorde Walmiki Samadhi
Keyword(s):  
Absorption Spectrometry ◽  
Combination Method ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Nickel Extraction ◽  
Nickel Recovery ◽  
Alkali Compounds ◽  
Decomposition Behavior ◽  
Hydrometallurgical Method

Extraction of limonite ore using dissolved SO2–air is an alternative hydrometallurgical method for nickel recovery. This process is carried out at atmospheric pressure and is shown to have good selectivity of nickel over iron, but with a low recovery yield. The literature refers to the application of alkali roasting as pretreatment in laterite ore leaching to increase nickel recovery. Thus, this study aims to apply the combination method of alkali roasting and leaching to extract nickel from limonite ore (1.33% Ni, 46.61% Fe) from the Southeast Sulawesi region. Three alkali compounds were included in the study (NaOH, Na2CO3 and Na2SO4). The batch-leaching process was carried out at pH 1 and 3 and temperatures of 55 and 80 °C for 180 min. The leach liquors were sampled at 15, 60, 90 and 120 min, and concentrations of the extracted metals were measured by Atomic Absorption Spectrometry (AAS). A mineralogy characterization of the raw ore and its residue after leaching was undertaken by using X-Ray Diffraction (XRD), while the thermal decomposition behavior of the ore was characterized by Thermogravimetry Analyzer (TGA)/Differential Scanning Calorimetry (DSC). The addition of Na2CO3, Na2SO4 and NaOH in the ore pretreatment increases nickel recovery from 14.80% without alkali roasting to 23.99%, 28.15% and 39.22%, respectively. The optimum extraction condition for nickel recovery is at pH 1 and a temperature of 80 °C. However, the highest Ni/Fe selectivity of 24,947 is obtained at pH 3 and a temperature of 80 °C, preceded by roasting in the absence of alkali. Compared to other hydrometallurgical processes, the process studied in this work exhibits lower recovery, but provides an alternative to extract nickel from low-grade limonite ore.

Preparation of hollow carbon submicro-fibers with controllable wall thicknesses from acrylonitrile copolymer

2017 ◽  
Vol 88 (16) ◽  
pp. 1893-1901 ◽  
Author(s):  
Anqi Ju ◽  
Shengfei Hou ◽  
Yuexiu Pan ◽  
Yue Wang ◽  
Yanan Zhu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Performance ◽  
Lithium Ion ◽  
Rechargeable Batteries ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Potential Applications ◽  
Hollow Carbon ◽  
Scanning Electron

Most of the hollow carbon submicro-fibers (HCSFs) reported today are made from polyacrylonitrile (PAN) homopolymer. The obtained HCSFs are fragile due to the poor stabilization and spinnability of PAN. In this study, a bifunctional comonomer, β-methylhydrogen itaconate (MHI), was synthesized to prepare poly(acrylonitrile- co-β-methylhydrogen itaconate) [P(AN- co-MHI)] copolymer, which was used as a precursor to produce HCSF by coaxial electrospinning. The stabilization of P(AN- co-MHI) was studied by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR); the structure of HCSFs was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and field emission scanning electron microscopy (FE-SEM). The stabilization of P(AN- co-MHI) has been improved significantly by MHI with lower cyclization temperature, broadened peak and lower activation energy, which is beneficial to producing high-performance HCSFs. HCSFs with fine and uniform structures were obtained after stabilization and carbonization; the diameter of the HCSFs shrinks due to the elimination of N and the extra H. The diameter and wall thickness of HCSFs can be controlled simply by the feeding ratio of P(AN- co-MHI) solution/styrene- co-acrylonitrile solution. The resultant HCSFs can be bent more than 280° without breaking, which has potential applications in lithium-ion rechargeable batteries, supercapacitors, fuel cells, and catalyst.

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