scholarly journals The longstanding challenge of the nanocrystallization of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX)

2017 ◽  
Vol 8 ◽  
pp. 452-466 ◽  
Author(s):  
Florent Pessina ◽  
Denis Spitzer
Keyword(s):  
Particle Size ◽  
Energetic Materials ◽  
Scale Up ◽  
High Explosives ◽  
Recent Advances ◽  
Key Points ◽  
Pyrotechnic Compositions

Research efforts for realizing safer and higher performance energetic materials are continuing unabated all over the globe. While the thermites – pyrotechnic compositions of an oxide and a metal – have been finely tailored thanks to progress in other sectors, organic high explosives are still stagnating. The most symptomatic example is the longstanding challenge of the nanocrystallization of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX). Recent advances in crystallization processes and milling technology mark the beginning of a new area which will hopefully lead the pyroelectric industry to finally embrace nanotechnology. This work reviews the previous and current techniques used to crystallize RDX at a submicrometer scale or smaller. Several key points are highlighted then discussed, such as the smallest particle size and its morphology, and the scale-up capacity and the versatility of the process.

Study on Ball Milling of TiH2 and Application in Energetic Materials

2014 ◽  
Vol 599-601 ◽  
pp. 107-110
Author(s):  
Bing Xue ◽  
Hong Hao Ma ◽  
Zhao Wu Shen ◽  
Yong Yu ◽  
Li Jie Ren
Keyword(s):  
Particle Size ◽  
Energetic Materials ◽  
Ball Mill ◽  
Particle Distribution ◽  
High Explosives ◽  
Initial Stage ◽  
Time Scanning ◽  
Detonation Speed ◽  
Mill Process ◽  
Scanning Electron

Particle distribution of titanium hydride (TiH2) during the ball mill process was studied by milling it with different time. Scanning electron microscope (SEM) pictures showed that particle size decreased quickly at the initial stage, and homogeneous, super fine TiH2 powder was obtained after 4 h mill. Application of TiH2 in energetic materials was investigated by preparation of TiH2/RDX composite explosive and measuring the detonation speed. Results showed that detonation speed of TiH2/RDX explosive was depended on the content and particle size of TiH2. TiH2 is a potential additive in high explosives (HE).

scholarly journals Using thermochemical code EXPLO5 to predict the performance parameters of explosives

2021 ◽  
pp. 17-27
Author(s):  
Muhamed Suceska ◽  
Barbara Stimac Tumara ◽  
Martin Künzel
Keyword(s):  
Numerical Modelling ◽  
Energetic Materials ◽  
Performance Parameters ◽  
Numerical Techniques ◽  
High Explosives ◽  
A Value ◽  
Measuring Techniques ◽  
Thermochemical Equilibrium ◽  
Pyrotechnic Compositions ◽  
Thermochemical Code

Thanks to the development of more powerful computers and efficient numerical techniques, numerical modelling has become a compulsory tool in solving various problems in the field of energetic materials. In cases where measuring techniques are still unable to measure a given parameter, numerical modelling may be the only option of obtaining a value. In addition, numerical modelling helps us to better understand some phenomena, particularly in understanding the influence of input parameters on output results, as well as saving time and money. The thermochemical equilibrium code EXPLO5 is such a tool which enables theoretical prediction of performance of high explosives, propellants and pyrotechnic compositions. The code is used by more than 80 research laboratories worldwide.

Azithromycin nanosuspension preparation using evaporative precipitation into aqueous solution (EPAS) method and its comparative dissolution study

2020 ◽  
Vol 17 ◽  
Author(s):  
Mohammad Hossain Shariare ◽  
Tonmoy Kumar Mondal ◽  
Hani Alothaid ◽  
Md. Didaruzzaman Sohel ◽  
MD Wadud ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Dissolution Rate ◽  
Average Particle Size ◽  
Scale Up ◽  
Average Particle ◽  
Total Drug ◽  
Residual Solvent ◽  
Dissolution Study ◽  
Drug Content

Aim: EPAS (evaporative precipitation into aqueous solution) was used in the current studies to prepare azithromycin nanosuspensions and investigate the physicochemical characteristics for the nanosuspension batches with the aim of enhancing the dissolution rate of the nanopreparation to improve bioavailability. Methods: EPAS method used in this study for preparing azithromycin nanosuspension was achieved through developing an in-house instrumentation method. Particle size distribution was measured using Zetasizer Nano S without sample dilution. Dissolved azithromycin nanosuspensions were also compared with raw azithromycin powder and commercially available products. Total drug content of nanosuspension batches were measured using an Ultra-Performance Liquid Chromatography (UPLC) system with Photodiode Array (PDA) detector while residual solvent was measured using gas chromatography (GC). Results: The average particle size of azithromycin nanosuspension was 447.2 nm and total drug content was measured to be 97.81% upon recovery. Dissolution study data showed significant increase in dissolution rate for nanosuspension batch when compared to raw azithromycin and commercial version (microsuspension). The residual solvent found for azithromycin nanosuspension is 0.000098023 mg/ mL or 98.023 ppb. Conclusion: EPAS was successfully used to prepare azithromycin nanoparticles that exhibited significantly enhanced dissolution rate. Further studies are required to scale up the process and determine long term stability of the nanoparticles.

scholarly journals Recent Advances in the BiVO4 Photocatalyst for Sun-Driven Water Oxidation: Top-Performing Photoanodes and Scale-Up Challenges

Catalysts ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. 13 ◽  
Author(s):  
Kristine Tolod ◽  
Simelys Hernández ◽  
Nunzio Russo
Keyword(s):  
Water Oxidation ◽  
Scale Up ◽  
Recent Advances

Nitrocellulose Catalyzed With Manganese Oxide Nanoparticles: Advanced Energetic Nanocomposite With Superior Decomposition Kinetics

2021 ◽  
Author(s):  
Sherif Elbasuney ◽  
M. Yehia ◽  
Shukri Ismael ◽  
Yasser El-Shaer ◽  
Ahmed Saleh
Keyword(s):  
Activation Energy ◽  
Particle Size ◽  
Manganese Oxide ◽  
Energetic Materials ◽  
Average Particle Size ◽  
Active Surface ◽  
Propagation Rate ◽  
Hydroxyl Groups ◽  
Average Particle ◽  
Decomposition Enthalpy

Abstract Nanostructured energetic materials can fit with advanced energetic first-fire, and electric bridges (microchips). Manganese oxide, with active surface sites (negatively charged surface oxygen, and hydroxyl groups) can experience superior catalytic activity. Manganese oxide could boost decomposition enthalpy, ignitability, and propagation rate. Furthermore manganese oxide could induce vigorous thermite reaction with aluminium particles. Hot solid or liquid particles are desirable for first-fire compositions. This study reports on the facile fabrication of MnO2 nanoparticles of 10 nm average particle size; aluminium nanoplates of 100 nm average particle size were employed. Nitrocellulose (NC) was adopted as energetic polymeric binder. MnO2/Al particles were integrated into NC matrix via co-precipitation technique. Nanothermite particles offered an increase in NC decomposition enthalpy by 150 % using DSC; ignition temperature was decreased by 8 0C. Nanothemrite particles offered enhanced propagation index by 261 %. Kinetic study demonstrated that nanothermite particles experienced drastic decrease in NC activation energy by - 42, and - 40 KJ mol-1 using Kissinger and KAS models respectively. This study shaded the light on novel nanostructured energetic composition, with superior combustion enthalpy, propagation rate, and activation energy.

scholarly journals Recent advances on thermal safety characterization of energetic materials

2018 ◽  
Author(s):  
P. C. Hsu ◽  
S. A. Strout ◽  
G. L. Klunder ◽  
E. M. Kahl ◽  
N. K. Muetterties ◽  
...  
Keyword(s):  
Energetic Materials ◽  
Thermal Safety ◽  
Recent Advances

scholarly journals Fiber Generators in Needleless Electrospinning

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Haitao Niu ◽  
Tong Lin
Keyword(s):  
Production Rate ◽  
Scale Up ◽  
Electrospun Nanofibers ◽  
Scaling Up ◽  
Electrospinning Process ◽  
Recent Advances ◽  
Needleless Electrospinning ◽  
Application Potential

The conventional electrospinning often uses a needle-like nozzle to produce nanofibers with a very low production rate. Despite the enormous application potential, needle electrospun nanofibers meet difficulties in broad applications in practice, due to the lack of an economic and efficient way to scale up the electrospinning process. Recently, needleless electrospinning has emerged as a new electrospinning mode and shown ability to produce nanofibers on large-scales. It has been established that the fiber generator, also referred to as “spinneret” in this paper, in needleless electrospinning plays a key role in scaling up the nanofiber production. This paper summarizes the recent advances in the development of needleless spinnerets and their influences on electrospinning process, nanofiber quality, and productivity.

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