resumo
Highly porous cellular ceramics were prepared by a versatile method combining emulsification of sunflower oil in alumina suspension, using collagen as surfactant, stabilizer and gelcasting additive. Emulsified suspensions show shear thinning behavior at emulsification temperatures, and their rheology was related to the volume fraction of dispersed oil droplets, collagen contents and stirring rate, based on a suitable Taguchi plan. This provides guidelines for the dependence of microstructural features on these processing parameters. The robustness of the method was demonstrated by the ability to perform early stages of burnout at relatively high heating rates, without risks of collapse or onset of factures in the resulting cellular ceramics. Combined DTG/DTA/FTIR studies were used to analyse the burnout stages, and provide guidelines to minimize emissions of gases with safety or environmental risks. (C) 2015 Elsevier Ltd. All rights reserved.
palavras-chave
IN-WATER EMULSIONS; POROUS CERAMICS; ALUMINA; RHEOLOGY; AGAROSE; CONSOLIDATION; BEHAVIOR; FOAMS; MODEL
categoria
Materials Science
autores
Sanches, MF; Vitorino, N; Freitas, C; Abrantes, JCC; Frade, JR; Neto, JBR; Hotza, D
nossos autores
João Carlos de Castro Abrantes
Professor Adjunto
Jorge Ribeiro Frade
Professor Catedrático
Nuno Miguel Dias Vitorino
Bolseiro de pós-DoutoramentoProjectos
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)
THERMICS- Cellular PCM-based composites with enhanced thermal conduction and shape stabilization (PTDC/CTM-ENE/2073/2012)
Centre for Research in Ceramics and Composite Materials - CICECO (LA0011: 2013-2014) (PEst-C/CTM/LA0011/2013)
agradecimentos
This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013, PTDC/CTM-ENE/2073/2012 and PEst-C/CTM/LA0011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement.; SEM facilities were funded by FEDER Funds through QREN - Aviso SAIECT-IEC/2/2010, Operacao NORTE-07-0162-FEDER-000050.; Nuno Vitorino and Mariana Sanches would like to acknowledge for their individual grants, SFRH/BPD/99367/2013 and CAPES 1235/11-2 respectively.