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Porous ceramics find applications in the field of filtration and separation, thermal insulation, catalyst support, and bone implant. The final porosity, pore size, and pore connectivity are significant factors influencing their properties and applications. Partial sintering of powder compacts, fugitive pore template method, polymer foam templating, foaming and setting of powder suspensions, and freeze casting are generally used for the preparation of porous ceramics. Among them fugitive pore templating is a simples and easy method for the preparation of porous ceramics. Various synthetic and natural materials are used as fugitive pore templates. The naturally renewable materials as pore template getting renewed interest due to environmental friendliness and sustainability. The present study reports preparation and characterization of porous ceramics using natural rubber latex (NRL) particles as pore templates. The natural rubber latex (NRL) particles are used as template for the preparation microporous alumina ceramics for the first time. The aqueous alumina powder dispersion using ammonium poly(acrylate) dispersant and concentrated natural rubber latex mixes easily by magnetic stirring due to the high negative surface charge on both alumina and NRL particles. The alumina-NRL co-dispersions show shear thinning flow behavior with low viscosity. The co-dispersion cast in a mold consolidates to alumina-NR composite bodies on drying at room temperature. The rubber chains in the alumina-NR composites undergo cross-linking through the double bonds present in the isoprene units on annealing at 200 °C. The cross-linked rubber from the green body exhibits a near steady-state burnout without creating any crack. The diametrical shrinkage during the sintering depends on the NR concentration. The porosity of the microporous ceramics sintered at 1350 °C increases from 42 to 58% when NR concentration increases from 15 to 30 wt.%. The microstructure indicated uniform distribution of micropores of average size nearly 0.74 µm. The relatively larger pore size observed at higher rubber concentrations indicated self-aggregation of NRL particles during consolidation by drying.

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Preparations of Macroporous Alumina Ceramics Using Banana Leaf Fiber as Pore Template

  • 会议论文

  • 发表日期：

    2025年

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  • E. Senthilkumar,
  • K. Prabhakaran,
  • Kasala Narasaiah,
  • G. Krishnakumar

摘要

Porous ceramics find applications in the field of filtration and separation, thermal insulation, catalyst support, and bone implant. The final porosity, pore size, and pore connectivity are significant factors influencing their properties and applications. Partial sintering of powder compacts, fugitive pore template method, polymer foam templating, foaming and setting of powder suspensions, and freeze casting are generally used for the preparation of porous ceramics. Among them fugitive pore templating is a simples and easy method for the preparation of porous ceramics. Various synthetic and natural materials are used as fugitive pore templates. The naturally renewable materials as pore template getting renewed interest due to environmental friendliness and sustainability. The present study reports preparation and characterization of porous ceramics using natural rubber latex (NRL) particles as pore templates. The natural rubber latex (NRL) particles are used as template for the preparation microporous alumina ceramics for the first time. The aqueous alumina powder dispersion using ammonium poly(acrylate) dispersant and concentrated natural rubber latex mixes easily by magnetic stirring due to the high negative surface charge on both alumina and NRL particles. The alumina-NRL co-dispersions show shear thinning flow behavior with low viscosity. The co-dispersion cast in a mold consolidates to alumina-NR composite bodies on drying at room temperature. The rubber chains in the alumina-NR composites undergo cross-linking through the double bonds present in the isoprene units on annealing at 200 °C. The cross-linked rubber from the green body exhibits a near steady-state burnout without creating any crack. The diametrical shrinkage during the sintering depends on the NR concentration. The porosity of the microporous ceramics sintered at 1350 °C increases from 42 to 58% when NR concentration increases from 15 to 30 wt.%. The microstructure indicated uniform distribution of micropores of average size nearly 0.74 µm. The relatively larger pore size observed at higher rubber concentrations indicated self-aggregation of NRL particles during consolidation by drying.