title: Synthesis and performance of bismuth trioxide nanoparticles for high energy gas generator use.
abstract: Our experiments showed that the combustion of an Al-Bi2O3 nanoparticle mixture generated the highest pressure pulse among common nanothermite reactions and can potentially be used as a nanoenergetic gas generator. The combustion front propagation velocity and rate of energy release increased by up to three orders of magnitude when the particle size was reduced to a nanosize range for both the aluminum and the oxidizer. We developed a novel one-step (metal nitrate-glycine) combustion synthesis of nanostructured amorphous-like and highly crystalline bismuth trioxide nanoparticles. The combustion synthesis was conducted using a solution of molten bismuth nitrate as an oxidizer and glycine as a fuel. The glycine was completely combusted during the thermal decomposition of the bismuth nitrate pentahydrate and generated a temperature front that propagated through the sample. Increasing the fuel concentration increased the maximum combustion temperature from 280 to 1200 degrees C and the Bi2O3 particle size from 20 to 100 nm. The oxidizer/fuel ratio had a strong impact on the bismuth trioxide particle crystallinity. At low temperature (280 degrees C), amorphous-like bismuth trioxide nanoparticles formed, while at T > or =370 degrees C the structures were crystalline. A peak pressure of approximately 12 MPa and a thermal front propagating velocity of approximately 2500 m s(-1) were achieved during the combustion of an Al-Bi2O3 mixture containing 80 wt% of the synthesized Bi2O3 crystalline nanoparticles (size: 40-50 nm).
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77204, USA. kmartirossian@uh.edu
authors.forename: K S
authors.initials: KS
authors.lastname: Martirosyan
authors.forename: L
authors.initials: L
authors.lastname: Wang
authors.forename: A
authors.initials: A
authors.lastname: Vicent
authors.forename: D
authors.initials: D
authors.lastname: Luss
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D008962:Models, Theoretical; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*
chemical_list: C033301:bismuth oxide; D001729:Bismuth