Combustion syntheses of CoAl2O4 powders using different fuels

MARÍA CELESTE GARDEY MERINO; ALFREDO L. ESTRELLA; MARIANA E. RODRIGUEZ; LEANDRO ACUÑA; MARÍA SILVINA LASSA; GUSTAVO E. LASCALEA; PATRICIA VÁZQUEZ

Procedia materials Science

Elsevier

Año: 2014

2211-8128

CoAl2O4 powders were obtained by combustion methods in which it is proposed the use of aspartic acid (Asp) or lysine (Lys) as fuels.  The  powders  obtained  were  calcined  between  600°C  and  1100°C.  Then,  these  powders  were  characterized  by  X-ray diffraction  (XRD),  scanning  electron  microscopy  (SEM),  transmission  electron  microscopy  (TEM)  and  Fourier  transform infrared spectroscopy  (FTIR). The purpose of  this work was to analyse  the potential use of CoAl2O4 as an opaque pigment  for selective paints  for  solar  collectors,  this  is possible when  average  crystallite  size  is micrometric.  In  all powders,  the CoAl2O4 phase was observed. The lowest average crystallite size was≈24 nm corresponding to the sample obtained with Asp and calcined at 600°C, meanwhile both powders calcined at 1100°C showed sizes higher than 200nm. Regarding these results, it is proposed that employing even higher calcination temperatures it could be obtained opaque pigments more suitable, for proper application.