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2013-04-19 - Colloque/Présentation - poster - Anglais - 1 page(s)

Sciamanna Valérie , Nait-Ali Benoît, Maury Nathalie , RGuiti Mohamed, Gonon Maurice , "Macroporous ceramics produced from stable foams and emulsions" in 2013 meeting of the Belgian Ceramic Society, University of Hasselt, Diepenbeek, Belgium, 2013

  • Codes CREF : Matériaux céramiques et poudres (DI2744)
  • Unités de recherche UMONS : Science des Matériaux (F502)
  • Instituts UMONS : Institut de Recherche en Science et Ingénierie des Matériaux (Matériaux)

Abstract(s) :

(Anglais) In this work, macroporous ceramics are produced from particle-stabilized wet foams and emulsions, following the procedures defined by Gonzenbach et al. [1] and Akartuna et al. [2]. Stable foams and emulsions are obtained thanks to adsorption of partially hydrophobic particles to the air/water or oil/water interface. The hydrophobization of particles is achieved through the adsorption of short-chain amphiphilic molecules (butyric acid) on the particle surface. The colloidal particles used in this study are: (a) ?-Al2O3 powder (Alcan P172 LSB, d50 = 0.41 µm) and (b) BaTiO3 powder (Inframat Advanced Materials, d50 = 50 nm). Macroporous alumina ceramics were characterized in terms of microstructure, mechanical properties and thermal conductivity. Microstructures of sintered alumina foams and emulsions reveal closed pores surrounded by a thin alumina layer. The microstructure of these macroporous ceramics is related with the composition of the initial suspension (alumina and butyric acid contents). Macroporous alumina ceramics with average pore sizes (d50) ranging from 20 µm to 85 µm and porosities between 25% and 80% were obtained after sintering at 1585°C for two hours. The mechanical properties (compressive strength, indirect tensile strength (Brazilian test) and flexural strength) of these porous samples were investigated. Thermal diffusivity measurements were performed at ambient temperature (23°C) with the laser flash technique in order to determine the effective thermal conductivity. Otherwise, porous BaTiO3 ceramics were obtained from stable foams. Foams were sintered at 1400°C for one hour. The piezoelectric properties of porous BaTiO3 samples were studied. First results show that it is possible to obtain a d33 piezoelectric coefficient of 170 pC/N with a porosity level of about 60%. References [1] Gonzenbach U.T., Studart A.R., Tervoort E., Gauckler L.J., "Macroporous Ceramics from Particle-Stabilized Wet Foams", J. Am. Ceram. Soc., 90 [1], 2007, pp. 16-22 [2] Akartuna I., Studart A.R., Tervoort E., Gauckler L.J., "Macroporous Ceramics from Particle-Stabilized Emulsions", Advanced Materials, 20, 2008, pp. 4714-4718