Influence of starch type on characteristics of porous 3Y-ZrO2 prepared from a direct consolidation casting method

Abstract

Starch consolidation casting has been successfully used to produce porous ceramics with complex shapes at a relatively low producing cost. In this work, porous 3Y-ZrO 2 ceramics were produced using two types of starch (corn and potato). Concentrated (50-52 vol. (%)) aqueous suspensions of the different 3Y-ZrO 2 -starch mixtures (i.e. starch to zirconia weight ratios between 0.20 and 0.52) were thermally consolidated and the effect of the type and amount of added starch on properties of resultant dried product was examined. After starch granules burnout, the effect of sintering temperature varying between 1000 and 1500 °C on the porosity evolution, interconnection and morphology of pores and microstructure of final ceramic was followed by water absorption measurements, Hg porosimetry and scanning electron microscopy SEM. Typical microstructure of the ceramic sintered at 1500 °C consisted of large nearly spherical pores (created by starch) uniformly distributed in a dense ZrO 2 matrix. As the content of starch in the dried product (expressed as volume fraction) X st is increased from 0.23 to 0.65, porosity of the ceramic sintered at 1500 °C increased from 38 to 52 vol. (%) for corn starch, while it achieved 50 to 54 vol. (%) for potato starch; thus, lower X st of potato starch developed a porous zirconia with higher porosity. In this case, the pore structure contained pores having sizes above 50 μm and resulted completely interconnected while for those prepared using corn starch the pore interconnection occurred for X st above 0.50.

Potentials of fabricating porous ceramic bodies from kaolin for catalytic substrate applications

“…Numerous pore-forming agents have been investigated, including starch (Zivcová et al, 2012;Khattab et al, 2012;Garrido et al, 2011;Chen et al, 2011;Zivcová et al, 2009;Zivcová et al, 2010;Gregorová et al, 2006), graphite (Sarikaya and Dogan, 2013;Sanson et al, 2008;Ding et al, 2007;Boaro et al, 2003), lycopodium (Zivcová et al, 2007;Zivcová et al, 2008;Seržane et al, 2010), sucrose (Sarikaya andDogan, 2013: Ray et al, 2010;Wang et al, 2005) and polymethyl methacrylate Yao et al, 2005;Kumar et al, 2005) and others (Bai et al, 2012;Horri et al, 2012 andSilva et al, 2002). Even though starch is the most frequently used pore forming agent, possibly due to its biological origin and availability, the difficulties in maintaining the pore structure formed by the starch burn out, and the narrow size range of commercially available starch types (typically between 5 and 50 μm) limits its application when large pores are desirable .…”

Starch Consolidation Casting of Cordierite Precursor Mixtures—Rheological Behavior and Green Body Properties

“…In fact, almost simultaneously with the publication of the 1998 key paper by Lyckfeldt and Ferreira, which presented the first results for alumina ceramics, this process has also been applied to cordierite ceramics . Further applications of this processing technique, using either native or modified starches, concerned porous calcium carbonate, silica, gibbsite, zirconia, mullite,, and even cermets and metals (porous steels) prepared by the powder metallurgy route . Also clay‐based materials, and, very recently, porcelain foams have been prepared using starch consolidation casting.…”

Preparation of macroporous membrane using natural Kaolin and Tunisian lignite as a pore-forming agent

“…The morphology of these voids will depend on the selected pore-forming agent, and thus can be controlled through suitable incorporation content and particle size distribution [18]. Numerous porogen agents have been investigated, including starch [19][20][21][22][23][24][25], graphite [26][27][28][29][30], lycopodium [31][32][33], sucrose [34,35], among others [36][37][38].…”