TY - JOUR
T1 - Exothermic surface reactions in alumina-aluminum shell-core nanoparticles with iodine oxide decomposition fragments
AU - Mulamba, Oliver
AU - Pantoya, Michelle
N1 - Funding Information:
Acknowledgments The authors gratefully acknowledge support from the Army Research Office under contract W911NF1110439 and encouragement from our Program Manager, Dr. Ralph Anthenien.
PY - 2014/3
Y1 - 2014/3
N2 - A pre-ignition reaction (PIR) once thought to be unique to aluminum (Al) and fluorine-based oxidizer reactions is observed for aluminum and an iodine-containing oxidizer. This PIR is exothermic and precedes the main exothermic reaction corresponding to aluminum combustion. For the aluminum and iodine oxide system, exothermic surface chemistry was recently predicted for I-O fragments forming bridge bonds with the alumina passivation shell using first principle calculations, but now has been observed experimentally. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) were used to assess aluminum and iodine pentoxide (I2O5) powder mixtures. Various equivalence ratios were examined and found to affect the PIR onset temperature. Prior to this work, the PIR was attributed solely to surface reactions of the halogen with the Al2O3 surface, but, results shown here indicate that both the alumina surface and aluminum core contribute to a PIR and a minimum activation energy is necessary for PIR production.
AB - A pre-ignition reaction (PIR) once thought to be unique to aluminum (Al) and fluorine-based oxidizer reactions is observed for aluminum and an iodine-containing oxidizer. This PIR is exothermic and precedes the main exothermic reaction corresponding to aluminum combustion. For the aluminum and iodine oxide system, exothermic surface chemistry was recently predicted for I-O fragments forming bridge bonds with the alumina passivation shell using first principle calculations, but now has been observed experimentally. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) were used to assess aluminum and iodine pentoxide (I2O5) powder mixtures. Various equivalence ratios were examined and found to affect the PIR onset temperature. Prior to this work, the PIR was attributed solely to surface reactions of the halogen with the Al2O3 surface, but, results shown here indicate that both the alumina surface and aluminum core contribute to a PIR and a minimum activation energy is necessary for PIR production.
KW - Alumina surface chemistry
KW - Aluminum combustion
KW - Halogen decomposition fragments
KW - Pre-ignition reactions
KW - Reaction kinetics
UR - http://www.scopus.com/inward/record.url?scp=84896489608&partnerID=8YFLogxK
U2 - 10.1007/s11051-014-2310-9
DO - 10.1007/s11051-014-2310-9
M3 - Article
AN - SCOPUS:84896489608
SN - 1388-0764
VL - 16
JO - Journal of Nanoparticle Research
JF - Journal of Nanoparticle Research
IS - 3
M1 - 2310
ER -