TY - JOUR
T1 - Study on growth of hollow nanoparticles of alumina
AU - Kulkarni, Naveen V.
AU - Karmakar, Soumen
AU - Asthana, Srinanadan N.
AU - Nawale, Ashok B.
AU - Sheikh, Arif
AU - Patole, Shashikant P.
AU - Yoo, J. B.
AU - Mathe, Vikas L.
AU - Das, Ashok K.
AU - Bhoraskar, Sudha V.
N1 - Funding Information:
Acknowledgements The authors extend their thanks to ARMREB (India) for funding the project. S V. Bhoraskar acknowledges CSIR (India) for granting her the ES Scheme.
PY - 2011/4
Y1 - 2011/4
N2 - This article addresses the growth of hollow nanocrystalline particles of γ-alumina by the post-oxidation of nano-aluminium particles in air. The nanoparticles of aluminium were synthesized in a DC-transferred arc thermal plasma reactor. The as-synthesized nano-aluminium particles were oxidized, in air, at different temperatures. The as-synthesized parent nano aluminium and their daughter nanoparticles of aluminium oxide were thoroughly characterized with the help of X-ray diffraction analysis, high resolution transmission electron microscopy and thermogravimetric analysis. Two-step oxidation behaviours, unique in nanoparticles, are found to be the main driving force behind the formation of hollow spherical structures. The entire phenomenon is compared with the oxidation behaviour of coarse grain aluminium. The content of γ-alumina, identified by X-ray diffraction, relative to that of unreacted aluminium, has increased almost exponentially with the oxidation temperature in the case of nano aluminium. Similar behaviour is not observed in the case of coarse grain aluminium. The crystalline features of alumina, forming the walls of the hollow sphere, were confirmed by high resolution transmission electron microscopy.
AB - This article addresses the growth of hollow nanocrystalline particles of γ-alumina by the post-oxidation of nano-aluminium particles in air. The nanoparticles of aluminium were synthesized in a DC-transferred arc thermal plasma reactor. The as-synthesized nano-aluminium particles were oxidized, in air, at different temperatures. The as-synthesized parent nano aluminium and their daughter nanoparticles of aluminium oxide were thoroughly characterized with the help of X-ray diffraction analysis, high resolution transmission electron microscopy and thermogravimetric analysis. Two-step oxidation behaviours, unique in nanoparticles, are found to be the main driving force behind the formation of hollow spherical structures. The entire phenomenon is compared with the oxidation behaviour of coarse grain aluminium. The content of γ-alumina, identified by X-ray diffraction, relative to that of unreacted aluminium, has increased almost exponentially with the oxidation temperature in the case of nano aluminium. Similar behaviour is not observed in the case of coarse grain aluminium. The crystalline features of alumina, forming the walls of the hollow sphere, were confirmed by high resolution transmission electron microscopy.
UR - http://www.scopus.com/inward/record.url?scp=79751530544&partnerID=8YFLogxK
U2 - 10.1007/s10853-010-5059-2
DO - 10.1007/s10853-010-5059-2
M3 - Article
AN - SCOPUS:79751530544
SN - 0022-2461
VL - 46
SP - 2212
EP - 2220
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 7
ER -