resumo
The ubiquitous presence of barium carbonate (BaCO3 - BC) as an impurity in barium titanate (BaTiO3 - BT) has been pointed out as the main reason for the well-known difficulties found by many investigators when attempting to process BT powders in aqueous media. Different and controversial arguments have been put forward to justify the observed aqueous processing difficulties of BT, but a satisfactory explanation is still to be found. With this aim, a systematic study was here undertaken to shed further light on the solid/liquid interactions occurring at the surface of BC and BT particles and their impact on the dispersion ability of both powders, separately and mixed in certain proportions. Long term colloidal stability and high solid loadings (60 vol.%) were obtained for BC, while colloidal instability and a lower maximum content of solids (50 vol.%) could be achieved for BT. This responds to the question risen in the title. (C) 2013 Elsevier Ltd, All rights reserved.
palavras-chave
POLYMERIC STABILIZATION; DISSOLUTION RATES; PART II; SUSPENSIONS; BATIO3; PH; TEMPERATURE; KINETICS; POWDERS
categoria
Materials Science
autores
Ferreira, JMF; Olhero, SM; Kaushal, A
nossos autores
Ajay Kaushal
Bolseiro de pós-Doutoramento
José Maria da Fonte Ferreira
Professor(a) Jubilado(a)
Susana Maria Henriques Olhero
Professor AuxiliarProjectos
Development of microelectromechanical systems by gelcasting - GELMEMS (PTDC/CTM/099489/2008)
agradecimentos
S.M. Olhero and Ajay Kaushal thanks to the Foundation for Science and Technology of Portugal (FCT) for the financial support under the grants SFRH/BPD/27013/2006 and SFRH/BPD/77598/2011. The authors would like to thank CICECO, Department of Ceramics and Glass Engineering, University of Aveiro for the facilities and to FCT for the financial support under the project PTDC/CTM/099489/2008.