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Thrust characteristics of nano-carbon/Al/oxygenated salt nanothermites for micro-energetic applications

Defence Technology（防务技术） 2023年第12期30卷 55-69页

作者： Ahmed Fahd Alex Baranovsky Charles Dubois Jamal Chaouki sherif elbasuney Shady Shokry Chemical Engineering Department Ecole Polytechnique de MontrealMontrealH3C 3A7Canada Energetic Materials and Nanotechnology Research Center Technical Research CenterCairo11765Egypt Mechanical and Mechatronics Engineering Department University of WaterlooOntarioN2L 3G1Canada Head of Nanotechnology Research Center Military Technical CollegeCairo11767Egypt Laser and Optoelectronics Research Center Technical Research CenterCairo11765Egypt

Combustion within small motors is key in the application-specific development of nanothermite-based micro-energetic systems. This study evaluates the performance of nanothermite mixtures in a converging-diverging nozzle and an open tube. Mixtures were prepared using nano-aluminum(n-Al),potassium perchlorate(KClO_(4)), and different carbon nanomaterials(CNMs) including graphene-oxide(GO), reduced GO, carbon nanotubes(CNTs) and nanofibers(CNFs). The mixtures were packed at different densities and ignited by laser beam. Performance was measured using thrust measurement,high-speed imaging, and computational fluid dynamics modeling, respectively. Thrust, specific impulse(ISP), volumetric impulse(ISV), as well as normalized energy were found to increase notably with CNM content. Two distinctive reaction regimes(fast and slow) were observed in combustion of low and high packing densities(20% and 55%TMD), respectively. Total impulse(IFT) and ISPwere maximized in the 5%GO/Al/KClO_4 mixture, producing 7.95 m N·s and 135.20 s respectively at 20%TMD, an improvement of 57%compared to a GO-free sample(5.05 m N·s and 85.88 s). CFD analysis of the motors over predicts the thrust generated but trends in nozzle layout and packing density agree with those observed experimentally;peak force was maximized by reducing packing density and using an open tube. The numerical force profiles fit better for the nozzle cases than the open tube scenarios due to the rapid nature of combustion. This study reveals the potential of GO in improving oxygenated salt-based nanothermites,and further demonstrates their applicability for micro-propulsion and micro-energetic applications.

关键词： Nanothermites Graphene oxide Reduced graphene oxide Carbon nano material Oxygenated salts Laser ignition Computational fluid dynamics

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Continuous hydrothermal synthesis of AlO(OH)nanorods as a clean flame retardant agent

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Particuology 2015年第5期13卷 66-71页

作者： sherif elbasuney School of Chemical Engineering Military Technical College

Aluminum-oxide-hydroxide （AIOOH） is a clean and non-toxic flame retardant. There have been many trials for the fabrication of ultrafine AIOOH, Two main approaches exist for nano-AlOOH synthesis： reactive precipitation and batch hydrothermal synthesis, Both approaches are laborious and time consuming with poor control of particle morphology. We report on the novel continuous flow manufacture of AIOOH nanorods with controlled morphology （particle size and shape） by hydrothermal synthesis. AIOOH was harvested from its mother liquor （colloidal solution） using poly（acrylamide-co-acrylic acid） copolymer as a flocculating agent. The developed AIOOH shape and size, crystalline phase, thermal stability, and endothermic heat sink action were investigated by transmission electron microscopy, X-ray diffractome- try, thermogravimetric analysis, and differential scanning calorimetry, respectively. The phase transition of AlOOH to Al2O3 was demonstrated by conducting different X-ray diffractometry scans from 400 to 700℃. These results may provide an option for the continuous synthesis of nano-AIOOH as a clean and non-toxic flame retardant with excellent thermal stability. Consequently, enhanced flammability properties can be achieved at low solids loading.

关键词： Flame retardants Hydrated minerals Hydrothermal synthesis

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Thermal decomposition of ammonium perchlorate catalyzed with CuO nanoparticles

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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 *** its initial thermal decomposition is an endothermic process that requires 102.5 J·g^-*** manner involves high activation energy and could render high burning rate *** study reports on the sustainable fabrication of CuO nanoparticles as a novel catalyzing agent for APC *** CuO nanoparticles with consistent product quality were fabricated by using hydrothermal *** micrographs demonstrated mono-dispersed particles of 15 nm particle *** diffractogram demonstrated highly crystalline *** synthesized colloidal CuO particles were effectively coated with APC particles via co-precipitation by using fast-crash solvent-antisolvent *** impact of copper oxide particles on APC thermal behavior has been investigated using DSC and TGA *** demonstrated an initial endothermic decomposition stage at 242℃ with subsequent two exothermic decomposition stages at 297,8℃ and 452.8℃ *** 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

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Synthesis and surface modification of nanophosphorous-based flame retardant agent by continuous flow hydrothermal synthesis

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Particuology 2015年第5期13卷 82-88页

作者： sherif elbasuney Hosam E.Mostafa School of Chemical Engineering Military Technical College

Nanoparticles can provide flame retardance to hosting polymers and act as nano fire extinguishers. Hydroxyapatite （Ca5（OH）（PO4）3）（HA） is not hygroscopic, and is thermally stable up to 800℃, with 18.5 wt% phosphorous content. It is this high phosphorous content that can provide HA with flame retardant properties. In this paper, we report on the continuous synthesis of ultrafine HA using a hydrothermal synthesis technique. The HA surface properties were changed from hydrophilic to hydrophobic by post-synthesis surface modification. The ratio of the HA nanoparticles and an intumescent agent known as Exolit AP750 was investigated to yield a self-extinguishing multi-component epoxy nanocomposite for extended application under extreme fire conditions. The HA/AP750/epoxy nanocomposite was able to resist a flame at 1700 oc and self-extinguish after the flame had been removed. The nanocomposite showed an enhanced flammability performance in standard cone calorimetry testing and formed a compact and cohesive protective char layer with a 50% decrease in peak heat released compared with virgin epoxy. Our aim was to establish the use of HA as an effective nanofiller with phosphorous-based flame retardant properties. The surface of this nano fire extinguisher was modified effectively with different surfactants for enhanced compatibility with different polymeric matrices.

关键词： Flame retardancy Phosphorous-based agent Nanocomposites Hydrothermal synthesis Hydroxyapatite

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Novel yellow colored flame compositions with superior spectral performance

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Defence Technology（防务技术） 2017年第1期13卷 33-39页

作者： Ramy Sadek Mohamed Kassem Mohamed Abdo sherif elbasuney School of Chemical Engineering Military Technical CollegeKobry El-KobbaCairoEgypt

The production of colored flames is the primary purpose of military signaling, projectile tracing, and illuminating devices. Certain elements and compounds when heated to high temperature have the unique property of emitting lines or narrow bands in the visible region(380-780 nm). This study, reports on the development of novel yellow colored flame compositions with enhanced spectral performance in terms of luminous intensity, and color quality to standard Russian yellow tracer. The light intensity and the imprint spectra of developed yellow flares were measured using digital luxmeter and UV e Vis. spectrometer respectively. The main giving of this study is that the light intensity, and color quality of Russian yellow tracer were improved by 287%, and 170% respectively. This was accomplished by means of optimizing the ratio of novel binder to color source using aluminum metal fuel. Aluminumbased formulations were found to maximize the formation of yellow reactive emitting specimens, and to eliminate any interfering incandescent emission resulted from Mg O. Quantification of yellow color emitting specimens in the combustion gaseous products was achieved using chemical equilibrium thermodynamic code named ICT(Institute of Chemical Technology in Germany, Virgin 2008); in an attempt to judge the light quality. This improvement in yellow flare performance established the rule that the emission intensity increases as the reaction temperature increases. In the meantime upper limit of temperature was avoided to maximize the color quality.

关键词： Pyrotechnics Colored flames Yellow tracer Atomic spectroscopy Color quality

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Chemical stability, thermal behavior, and shelf life assessment of extruded modified double-base propellants

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Defence Technology（防务技术） 2018年第1期14卷 70-76页

作者： sherif elbasuney Ahmed Fahd Hosam E.Mostafa sherif F.Mostafa Ramy Sadek School of Chemical Engineering Military Technical College

Double base propellant suffers from lack of chemical stability; this could result in self ignition during storing. Modified double base(MDB) propellant based on stoichiometric binary mixture of oxidizermetal fuel(Ammonium perchlorate/Aluminum), and energetic nitramines(HMX) offered enhanced thrust as well as combustion characteristics. This study is devoted to evaluate the impact of such energetic additives on thermal behavior, chemical stability, and shelf life. Extruded MDB formulations were manufactured by extrusion process. Artificial aging at 80℃ for 28 days was conducted. Shelf life assessment was performed using Van't Hoff's equation. Quantification of evolved NOxgases with aging time was performed using quantitative stability tests. MDB formulation based on HMX demonstrated extended service life of 16 years compared with(AP/Al)-MDB which demonstrated 9 years. This finding was ascribed to the reactivity of AP with nitroglycerin with the formation of perchloric acid. Thermal behavior of aged MDB, exhibited an increase in heat released with time; this was ascribed to the autocatalytic thermal degradation during artificial aging. The increase in released heat by 31% was found to be equivalent to evolved NOx gases of 6.2 cm^3/5 g and 2.5 cm^3/1 g for Bergmann-Junk test, and Vacuum stability test respectively. This manuscript shaded the light on a novel approach to quantify evolved NOx gases to heat released with aging time. MDB based on HMX offered balanced ballistic performance,chemical stability, and service life.

关键词： Double-base Chemical stability Thermal behavior Artificial aging Shelf life assessment

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Spectrally adapted red flare tracers with superior spectral performance

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Defence Technology（防务技术） 2017年第6期13卷 406-412页

作者： Ramy Sadek Mohamed Kassem Mohamed Abdo sherif elbasuney School of Chemical Engineering Military Technical CollegeKobry ElkobaCairoEgypt

The production of bright light, with vivid color, is the primary purpose of signaling, illuminating devices,and fire control purposes. This study, reports on the development of red flame compositions with enhanced performance in terms of luminous intensity, and color quality. The light intensity and the imprint spectra of developed red flame compositions to standard NATO red tracer(R-284 NATO) were measured using digital luxmeter, and UV-Vis. spectrometer. The main giving of this study is that the light intensity of standard NATO red tracer was increased by 72%, the color quality was also improved by60%(over the red band from 650 to 780 nm). This enhanced spectral performance was achieved by means of deriving the combustion process to maximize the formation of red color emitting species in the combustion flame. Thanks to the optimum ratio of color source to color intensifier using aluminum metal fuel; this approach offered the highest intensity and color quality. Upon combustion, aluminum was found to maximize the formation SrCL(the main reactive red color emitting species) and to minimize the interfering incandescent emission resulted from MgO and SrO. Quantification of active red color emitting species in the combustion flame was conducted using chemical equilibrium thermodynamic code named ICT. The improvement in red flare performance, established the rule that the color intensifier should be in the range from 10 to 15 Wt % of the total composition.

关键词： Pyrotechnics Colored flames Tracers Luminous intensity Molecular spectroscopy

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

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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 *** can act as an efficient oxidizer and mono-propellant as *** this study,AP experienced crystallographic phase change from orthorhombic centrosymmetric to non-centrosymmetric under controlled isothermal heat *** diffractograms confirmed this crystallographic phase *** thermal behaviour of activated AP had been investigated using *** 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/*** AP can secure self-sustained response at a high *** index(combustion enthalpy/ignition temperature)was employed to assess self-sustained reaction *** AP demonstrated high propagation index of 8.7 compared with 2.5 for un-activated *** decomposition kinetic parameters had investigated using Kissinger and KAS *** 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 *** 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

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Novel colored flames via chromaticity of essential colors

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Defence Technology（防务技术） 2019年第2期15卷 210-215页

作者： Ramy Sadek Mohamed Kassem Mohamed Abdo Ahmed Fahd Hesham Tantawy Amir Elsaidy sherif elbasuney School of Chemical Engineering Military Technical College

Colored flame compositions have distinctive variety of applications ranging from military signaling,rocket tracking, and illuminating devices. Certain elements and compounds when heated to high temperature are able to emit unique wavelengths in the visible region. This study, reports on the development of novel colored flames that cannot be generated by emitting atomic/molecular species. This was achieved by using chromaticity of basic colored flames. Mixing of high quality primary colored flames including Blue, Yellow, and Red in proper ratio was conducted; any interfering incandescent emission resulted from MgO was eliminated using Al metal fuel. The spectral characteristics in terms of luminous intensity, and color quality were evaluated using digital luxmeter and UV-Vis. spectrometer *** quality mixed colored flames include violet, sweet pink, and marigold were developed. This study shaded the light on the state of the art for the real development of novel colored flame compositions and chromaticity of basic colored flames.

关键词： Pyrotechnics Colored flame Atomic spectroscopy Molecular spectroscopy Luminous intensity Color quality Chromaticity

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Novel approach to quantify the chemical stability and shelf life of modified double-base propellants

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Defence Technology（防务技术） 2018年第6期14卷 720-724页

作者： Ashraf M.A.Elghafour Mostafa Radwan Ahmed Fahd Hosam E.Mostafa sherif elbasuney School of Chemical Engineering Military Technical CollegeKobry El-KobbaCairoEgypt British University in Egypt Elshrouk CityCairoEgypt

Double-base(DB) propellant is vulnerable to auto-catalytic decomposition reactions during storing with the evolution of nitrogen oxides. Modified DB propellant based on energetic nitramines(RDX) can offer enhanced thrust and action time. This study is devoted to evaluate the impact of RDX on chemical stability and shelf life of DB propellant. Extruded modified DB propellant based on RDX was manufactured by solventless extrusion process. Shelf life assessment was performed using an artificial aging at70 ℃ up to 120 days and employing Van't Hoffs formula. Quantification of evolved NOx gases and stabilizer depletion with aging time was conducted using Bergmann-Junk test and HPLC *** DB formulation based on RDX 20 wt % demonstrated enhanced chemical stability and extended service life up to 46 years compared with reference formulation. This finding was ascribed to the high chemical and thermal stability of RDX as well as its compatibility with DB constituents; no side chemical reactions could take place during storing. This manuscript shaded the light on RDX as effective energetic constituent that offered DB propellants with enhanced performance, good chemical stability, and extended service life.

关键词： Double-base propellant Chemical stability Artificial aging Shelf life assessment

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