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Novel sol-gel methodology to produce LaCoO <inf>3</inf> by acrylamide polymerization assisted by γ-irradiation

Abstract:

In this paper we report the synthesis of LaCoO 3 (LCO) nano-particles with two methodologies: the conventional sol-gel reaction of acrylamide (AA) polymerization using a cross-linking agent (methylenebisacrylamide or MBA) with the activation of the polymerization reaction by thermo-chemical initiator (azobisisobutyrnitrile or AIBN). The second was a novel sol-gel methodology in which the polymerization of AA monomers was done without MBA and the initiation was achieved by gamma radiation. With thermochemical initiator a xerogel with a foam and porous structure was obtained, while the gamma-irradiation of the mixture leads to the formation of a compact resin with entrapped cations. X-ray diffraction (XRD) shows that formation of the product begins around 500°C and according to analysis of microscopy images of powders calcined in 700°C the average sizes of particles are 20nm and 42nm for samples obtained using γ-irradiation and AIBN as initiators, respectively. TEM images also show differences in particle morphology. Those synthesized using AIBN as initiator are dispersed, while those with γ-irradiation are in aggregates. © 2012 Elsevier Ltd.