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Tuning the Laser Ignition Properties of Nitrocellulose-Nitroglycerine-Hexogen Propellants via Incorporation of Carbon Nanotubes

Shi Xianrui, Jia Yongjie, Chen Linyu, Tian Lu, Shen Jinpeng, Pei Chonghua

Central European Journal of Energetic Materials

2021

Vol. 18, no. 3

385--404

Near infrared laser ignition is challenging owing to the poor near infrared laser absorption of nitrocellulose-nitroglycerine-hexogen (NC-NG-RDX) propellants. Less than 1 wt.% of carbon nanotubes (CNTs) were uniformly dispersed into the NC-NG-RDX propellants to tune its near infrared laser ignition property. The effects of CNTs on the thermal decomposition, near infrared light absorption and thermal conductivity of NC-NG-RDX propellants were studied. The near infrared laser ignition property of NC-NG-RDX propellants doped with CNTs were investigated compared with raw NC-NG-RDX propellant. The decomposition property and thermal conductivity of NC-NG-RDX propellants doped with CNTs were little changed due to the small quantity of CNTs. The laser reflectivity of the composite propellants decreased obviously as the content of CNTs was increased because of the high laser absorption property of CNTs. The laser ignition performance of the composites propellants is substantially improved by the incorporation of 0.5 wt.% or less CNTs and the successful ignition time decreases remarkably. Higher CNT content, such as 0.75 wt.% can lead to failure of laser ignition due to the excessive laser absorption efficiency and heating rate of the radiated region of the composite propellants together with inefficient deflagration. Our research reveals that the appropriate proportion of CNTs can potentially be used as a laser sensitizer for realizing effective infrared laser ignition of NC-NG-RDX propellants.

Laser Ignition of an Optically Sensitised Secondary Explosive by a Diode Laser

Fang X., Ahmad S. R.

Central European Journal of Energetic Materials

2016

Vol. 13, no. 1

103--115

As a green technology, laser ignition of a relatively insensitive secondary explosive has been experimentally investigated. The explosive, hexanitrostilbene (HNS), was doped with one of two optical sensitizers, carbon black or a laser absorbing dye, and a continuous-wave (CW) infrared diode laser was used as the igniting source. The ignition sensitivities of HNS with each of the two optical sensitizers were analysed and compared in terms of: optical power threshold for ignition, ignition delay and full burn delay at various laser powers. The results have shown that both the chemical dye and carbon black optically sensitize the explosive with similar efficiencies. In contrast to the carbon black, the dye provides wavelength specificity and selectivity in the laser ignition process and its solubility in some specific solvents improves the coating of the explosive material. It was therefore concluded that the laser absorbing dye is a better candidate for optical sensitization in laser ignition than the commonly used carbon black. The combination of laser ignition sensitivity with wavelength selectivity potentially offers higher reliability and safety at a low optical power for future ignitors of secondary explosives.

Controlled Synthesis and Application of Nano-energetic Materials Based on the Copper Oxide/Al System

He S., Chen J., Yang G., Qiao Z., Li J.

Central European Journal of Energetic Materials

2015

Vol. 12, no. 1

129--144

Nanothermite composites containing metal oxide and metal fuel are attracting attention due to their outstanding combustion characteristics. The morphology of metal oxide is important for the performance of nanothermite composites. In this paper, branch-, plate-, sphere-, and hollow sphere-like CuO nano/microstructures were synthesized via a facile hydrothermal process. The CuO/Al based nanothermites were prepared via ultrasonic mixing of the asobtained CuO products and nano-Al. The combustion behaviour of CuO/Al based nanothermites was analyzed by DSC and laser ignition. This study shows that this nanoscale mixing resulted in a large interfacial contact area and low diffusional resistance between the fuel and the oxidizer, and the reaction reflects large energy and laser ignition sensitivity.