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

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 20 nm and 42 nm 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.