Novel sol–gel methodology to produce LaCoO3 by acrylamide polymerization assisted by γ-irradiation

• Published in: Radiation physics and chemistry (Oxford, England : 1993) England : 1993), 2012-05, Vol.81 (5), p.512-518
• Main Authors: Carabalí, G., Chavira, E., Castro, I., Bucio, E., Huerta, L., Jiménez-Mier, J.
• Format: Article
• Language: English
• Subjects: Acrylamide; Gamma radiation; Initiators; MBA; Methodology; Nanostructure; Polyacrylamide; Polymerization; Semiconductor material LaCoO3; Sol gel process; Sol–gel reaction; Thermochemical initiator
• ISSN: 0969-806X; 1879-0895
• DOI: 10.1016/j.radphyschem.2012.01.039

In this paper we report the synthesis of LaCoO3 (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. ► LaCoO3 nano-crystallites were synthesized by two different polyacrylamide sol–gel processes. ► Acrylamide polymerization reaction initiated by gamma irradiation and by thermo-chemical agent. ► Polymerization reaction with thermo-chemical initiator produces a porous gel. ► Xerogel obtained using gamma radiation is compact resin. ► LaCoO3 powders produced by both methods differ in the size and morphology of particles.