[CCoE Notice] PhD Defense Announcement

[Khator, Suresh]

Ph.D. Defense Announcement

Leizheng Wang

Friday, July 15, 2011, 12:30 PM, Chemical Engineering Conference Room
Major Professor: Dr. Dan Luss


Nanoenergetic Gas Generators

Conventional energetic materials typically have relatively low energy density and reaction burn rate. By reducing the reactant particle size from micron size to nano scale, nanothermite mixtures decrease the diffusion and transport limitation, exhibiting a superfast reactivity and high pressure release rate during nanothermite reactions. These novel nanoergnergetic materials have the potential to become the next generation explosive and propellant.

 In this study, numerous nanothermite mixtures (metal oxide, polymer, Carbon nanotube with different sizes of aluminum particles) were tested for high gas pressure release during the nanothermite reactions. By decreasing the particle size from micron to nano scale, the pressure release increased up to three orders of magnitude during reactions. Bi2O3/Al and I2O3/Al nanothermite mixtures exhibited the highest pressure release. Using a 0.5 g of the nanothermite mixtures generated a peak pressures exceeding over 13 MPa. The combustion velocity was measured up to 2500 ms/s and the maximum reaction temperature measured by IR camera was over 2700 ºC during nanothermite reactions. We also synthesized the Bi2O3 nanoparticles by a solution combustion synthesis method. The results show the structure and morphology of metal oxide particle significantly affected the pressure release during nanothermite reactions.

 Reducing the thermite reactant particle sizes also decreased the reaction activation energy. The alumina layer surrounding the nano aluminum particles was  critical when considering the nanothermite reaction rate and pressure release rate. The low melting temperature and short melting time of nanoaluminum particles enhance the nanothermite reactivity and the pressure release.
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