检索结果-南通市图书馆

Cellulose Nanocrystal from Washingtonia Fibre and Its Characterization

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2022年第6期10卷 1459-1470页

作者： Mohammad Jawaid Lau Kia Kian Hassan Fouad Ramzi Khiari Othman Y.Alothman Mohamed Hashem Laboratory of Biocomposite Technology Institute of Tropical Forestry and Forest Products(INTROP)Universiti Putra MalaysiaSelangorMalaysia Applied Medical Science Department Community CollegeKing Saud UniversityRiyadhSaudi Arabia CNRS University of Grenoble AlpesGrenobleFrance Department of Textile Higher Institute of Technological Studies of Ksar HellalKsar HellalTunisia University of Monastir Laboratory of Environmental Chemistry and Cleaner Process(LCE2P-LR21ES04)MonastirTunisia Chemical Engineering Department College of EngineeringKing Saud UniversityRiyadhSaudi Arabia Dental Health Department College of Applied Medical SciencesKing Saud UniversityRiyadhSaudi Arabia

Cellulose nanocrystal(CNC)is a biomaterial derived from plant lignocellulosic components,widely applied in various industrial fields.Concurrently,with the growth of awareness in developing green nanomaterial,the explored Washingtonia fibre could be alternative biomass for obtaining CNC products.In the present work,different acid concentrations of 5%,15%,and 25%hydrochloric solutions were employed to produce CNCs from Washingtonia fibre.With the chemical treatments,the yield of the CNC product was successfully retained at 21.6%-25.1%.Individually separated and needle-shaped CNC particles could be observed under the microscopic viewing with the increased acid concentrations.From elemental analysis,a relatively pure cellulose compartment was produced for all CNC samples.The zeta potential values between-10 to-16 mV proved that each nanoparticle sample possessed dispersion ability within an aqueous solution.Meanwhile,the degree of crystallinity and the thermal behavior of CNCs were enhanced with the increased acidic concentrations.Hence,the isolated CNCs(with 15%)from Washingtonia fibre lead a CNC with the highest aspect ratio(30).This parameter is so important that these structures show empowering points of view as nanomaterials for reinforced polymer composites,and it could be a reliable nano-filler for the composite fabrication process in the future.

关键词： Cellulose nanocrystal washingtonia fibre structure degree of crystallinity thermal behavior

thermal decomposition of ammonium perchlorate catalyzed with CuO nanoparticles

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2019年第6期15卷 868-874页

作者： Sherif Elbasuney M.Yehia Head of Nanotechnology Research Center School of Chemical EngineeringMilitary Technical College

Ammonium perchlorate(APC)is the most common oxidizer in use for solid rocket propulsion systems.However its initial thermal decomposition is an endothermic process that requires 102.5 J·g^-1.This manner involves high activation energy and could render high burning rate regime.This study reports on the sustainable fabrication of CuO nanoparticles as a novel catalyzing agent for APC oxidizer.Colloidal CuO nanoparticles with consistent product quality were fabricated by using hydrothermal processing.TEM micrographs demonstrated mono-dispersed particles of 15 nm particle size.XRD diffractogram demonstrated highly crystalline material.The synthesized colloidal CuO particles were effectively coated with APC particles via co-precipitation by using fast-crash solvent-antisolvent technique.The impact of copper oxide particles on APC thermal behavior has been investigated using DSC and TGA techniques.APC demonstrated an initial endothermic decomposition stage at 242℃ with subsequent two exothermic decomposition stages at 297,8℃ and 452.8℃ respectively.At 1 wt%,copper oxide offered decrease in initial endothermic decomposition stage by 30%.The main outcome of this study is that the two main exothermic decomposition peaks were merged into one single peak with an increase in total heat release by 53%.These novel features can inherit copper oxide particles unique catalyzing ability for advanced highly energetic systems.

关键词： Ammonium perchlorate Catalyst thermal behavior Energetic systems Catalyzed propellants

Thermochemical Aspects of Activated Ammonium Perchlorates with Superior thermal Stability,Decomposition Enthalpy,Propagation Index,and Decomposition Kinetic Parameters

在线全文

学校读者我要写书评

暂无评论

Journal of thermal Science 2021年第6期30卷 2196-2201页

作者： SHERIF Elbasuney M.Yehia SHUKRI Ismael SHERIF Farag AHMED Saleh GHARIEB S.El-Sayyad Head of Nanotechnology Research Center Military Technical College(MTC)Cairo 11646Egypt School of Chemical Engineering Military Technical College(MTC)Cairo 11646Egypt Science and Technology Center of Excellence Cairo 11646Egypt Drug Radiation Research Department National Center for Radiation Research and Technology(NCRRT)Egyptian Atomic Energy Authority(EAEA)Cairo 11646Egypt

Ammonium perchlorate(AP)includes oxidizing and reducing elements on the same molecule.AP can act as an efficient oxidizer and mono-propellant as well.In this study,AP experienced crystallographic phase change from orthorhombic centrosymmetric to non-centrosymmetric under controlled isothermal heat treatment.XRD diffractograms confirmed this crystallographic phase change.The thermal behaviour of activated AP had been investigated using DSC.Activated AP demonstrated high chemical stability with an increase in endothermic phase transition enthalpy by 170%.The enthalpy of the subsequent two main exothermic decomposition reactions was increased by 250%.Whereas AP demonstrated total decomposition enthalpy of 733 J/g,activated AP showed 2614 J/g.Activated AP can secure self-sustained response at a high rate.Propagation index(combustion enthalpy/ignition temperature)was employed to assess self-sustained reaction propagation.Activated AP demonstrated high propagation index of 8.7 compared with 2.5 for un-activated AP.Primary decomposition kinetic parameters had investigated using Kissinger and KAS methods.Activated AP showed an increase in activation energy by 89%using the Kissinger method;kinetic parameters using the KAS method were in good agreement with the Kissinger method.It can have concluded that AP with novel kinetic decomposition parameters for enhanced safety storage and high combustion characteristics has evolved.

关键词： solid propellants oxidizers thermal behavior Kinetic parameters activation energy

Effects of rare earth oxide additives on the thermal behaviors of aluminum nitride ceramics

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2009年第6期28卷 596-599页

作者： YAO Yijun WANG Ling LI Chuncheng JIANG Xiaolong QIU Tai School of Mathematics and Physics Nanjing University of Information and Science Technology Nanjing 210044 China College of Materials Science and Engineering Nanjing University of Technology Nanjing 210009 China

The effects of Y2O3 and Er2O3 on the sintering behaviors, thermal properties and microstructure of A1N ceramics were investigated. The experimental results show that the sintering temperature can be decreased; the relative density and thermal behavior can be improved by adding rare earth oxide in A1N ceramics. For A1N ceramics with 3 wt.% Er2O3 additive, the relative density is 98.8%, and the thermal conductivity reaches 106 W.m^-1.K^-1. The microstructure research found that no obvious aluminum erbium oxide was found in A1N ceramics doped with 3 wt.% Er203, which favored the improvement of the thermal conductivity of A1N ceramics.

关键词： alumina nitride rare earth oxide thermal behavior sintering

Synthesis, Structure and thermal behaviors of a Magnesium(Ⅱ) Complex with Tetrazole-1-acetic Acid

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2013年第7期32卷 981-988页

作者：李志敏张同来张国涛杨利周遵宁张建国 State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology The 42nd Institute of the Fourth Academy of CASC

A new complex of magnesium with tetrazole-l-acetic acid （tza） has been synthe- sized and characterized by elemental analysis and FT-IR spectrum. Single-crystal X-ray diffraction analysis determined the molecular formula as Mg（tza）2（H20）4. The crystal belongs to the triclinic system with Pi space group, and a = 6.133（2）, b = 6.488（2）, c = 10.0127（7） A, a = 77.282（10）, fl = 91.558（1）, ）, = 76.002（8）°, Y = 349.0（2）A3, Z = 1, C6HI4MgNsOs, Mr = 350.56, Dc = 1.668 g.cm-3, F（000） = 182,μ = 0.189, S = 1.000, the final R = 0.0294 and wR = 0.0785 for 1128 observed reflections with I 〉 20-（I）. In this molecule, the tza ion exhibits an infrequent monodentate coordination mode. The magnesium center is hexa-coordinated to a slightly distorted octahedral configuration by six oxygen atoms from two tza ligands and four coordinated water molecules. DSC and TG-DTG analyses were applied to assess the thermal decomposition behavior. The kinetic parameters of the exothermal peak were calculated by non-isothermal reaction kinetics. The values of critical temperature of thermal explosion, △S≠, △H≠ and △G^≠, were obtained as 596 K, -42.25 J mo1^-1 K^-1, 296.43 kJ mol^-1 and 323.53 kJ mol1, respectively.

关键词： energetic materials magnesium complex tetrazole-l-acetic acid crystal structure thermal behavior

Synthesis,Crystal Structure and thermal Analysis of N-(2,3-Dimethyl-phenyl)-N'-(methoxyl formyl)thiourea

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2012年第2期28卷 230-233页

作者： ZHAO Dan HUANG Jie SONG Ji-rong ZHONG Yi-tang WANG Li-qin HE Jian-yun Shaanxi Key Laboratory of Physico-inorganic Chemistry Department of Chemical EngineeringNorthwest UniversityXi'an 710069P.R.China Conservation Technology Department the Palace MuseumBeijing 100009P R.China

N-（2,3-Dimethyl-phenyl）-N＇-（methoxyl formyl）thiourea was synthesized by the reacting of 2,3-dimethylaniline,potassium thiocyanate（KSCN） and methyl chloroformate（ClCOOCH 3）.Single crystal was obtained by slowly evaporation solvent at room temperature.The structure was characterized by elemental analysis,IR and X-ray crystalography.The compound crystallized：a triclinic system with space group Pī,a=0.83440（12） nm,b=0.89113（13） nm,c=0.93015（13） nm,α=76.548（2） o,β=63.906（2） o,γ=82.538（2） o,V=0.60379（15） nm 3,Z=2,D c =1.311 mg/m 3,F（000）=252,μ=0.256 mm-1,R 1 =0.0379,wR 2 =0.0919.The specific heat capacity of the title compound was determined by a Micro-DSC method,and the specific heat capacity was 1.25 J·g-1 ·K-1 at 298.15 K.Thermodynamic functions,relative to those at the standard temperature of 298.15 K,were calculated via thermodynamic relationship.The thermal behavior of the title compound under a non-isothermal condition was studied by differential scanning calorimetry/thermogravimetric（DSC/TG） method.There was an obvious endothermic peak in the DSC curve,the peak temperature was 479.43 K.The compound mass loss was 89.94% observed from the TG curve.

关键词： X-Ray diffraction Acylthiourea Crystal structure Specific heat capacity thermal behavior

thermal Analysis of Sclerotium of Pleurotus tuber-regium (osu) for Effective Drying

在线全文

学校读者我要写书评

暂无评论

World Journal of Engineering and Technology 2023年第1期11卷 153-163页

作者： Austin I. Gbasouzor Klein Ileleji Department of Agricultural and Biological Engineering College of Engineering Purdue University West Lafayette IN USA

thermal drying could lead to the deterioration of substance which affect its nutraceutical and chemical properties. Hence, thermal stability of substance is necessary in course of its drying to acertain the degree of temperature it will be subjected to. In this research, sclerotium of Pleurotus tuberregium is subjected to thermogravimetric analysis, differential thermal analysis and differential scanning calorimetry. Both thermogravimetric analysis and differential thermal analysis were conducted from ambient temperature to 1000°C at a rate of 20°C/min constant heating rate, while differential scanning calorimetry was conducted from ambient temperature to 400°C at a rate of 10°C/min constant heating rate. Besides, the oxides contents of sclerotium of Pleurotus tuberregium were determined using x-ray fluorescence analysis and the mircostruture was determined with scanning electron microscopy. It was discovered that complete dehydration of the sample ended at about 110.38°C and oxidation reaction occurred between 233.42°C to 373.82°C with release of heat by the sample. Sclerotium of Pleurotus tuber-regium is thermal stable up to 233.42°C with decompostion of steroid which is its second major component at about 400°C to 480°C. The x-ray fluorescence analysis of sclerotium of Pleurotus tuber-regium revealed that Na2O, MgO, SiO2, Al2O3, and Fe2O3 are the major compound and SEM analysis showed that it is a solid with amorphous structure having some fibrous skeleton. This study revealed that sclerotium of Pleurotus tuberregium could be dried to minimal moisture content without the deterioration of its nutritional and medinicnal properties.

关键词： Bio-Active Macro-Fungi osu thermal behavior Nutraceutical

Structural Characterization and thermal behavior of 1-amino-1-hydrazino-2,2-dinitroethylene guanidine salt

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Structural Characterization and Thermal behavior of 1-amino-...

Synthesis,crystal structure and thermal behavior of a new high-nitrogen energetic compound:（NH4）2DNMT

中国化学会第28届学术年会

作者：徐抗震张航宋纪蓉赵凤起 Department of Chemical Engineering Northwest University

＜正＞"Push-pull" nitro-enamine is a kind of compound with special construction, which possessesa highly polarized carbon-carbon double bond with positive and negative charges being stabilized by the

关键词： 1,1-Diamino-2,2-dinitroethylene （FOX-7） 1-Amino-1-hydrazino-2,2-dinitroethylene （AHDNE） Guanidine salt Synthesis thermal behavior

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Synthesis,crystal structure and thermal behavior of a new hi...