Porous ceramics have been widely used in heat insulation, filtration, and as a catalyst carrier. Ceramics with high porosity and high strength are desired; however, this high porosity commonly results in low strength materials. In this study, porous alumina with high porosity and high strength was prepared by a popular direct foaming method based on particle-stabilized wet foam that used ammonium polyacrylate (PAA) and dodecyl trimethyl ammonium chloride (DTAC) as the dispersant and hydrophobic modifier, respectively. The effects of the dispersant and surfactant contents on the rheological properties of alumina slurries, stability of wet foams, and microstructure and mechanical properties of sintered ceramics were investigated. The microstructure of porous ceramics was regulated using wet foams to achieve high strength. For a given PAA content, the wet foams exhibited increasing stability with increasing DTAC content. The most stable wet foam was successfully obtained with 0.40 wt% PAA and 0.02 wt% DTAC. The corresponding porous alumina ceramics had a porosity of 82%, an average grain size of 0.7 µm, and a compressive strength of 39 MPa. However, for a given DTAC content, the wet foams had decreasing stability with increasing PAA content. A possible mechanism to explain these results is analyzed.

多孔陶瓷已广泛用于绝热，过滤和用作催化剂载体。要求具有高孔隙率和高强度的陶瓷。但是，这种高孔隙率通常导致材料强度低。在这项研究中，通过一种流行的直接发泡方法，基于颗粒稳定的湿泡沫，制备了具有高孔隙率和高强度的多孔氧化铝，分别使用聚丙烯酸酯铵（PAA）和十二烷基三甲基氯化铵（DTAC）作为分散剂和疏水改性剂。 。研究了分散剂和表面活性剂含量对氧化铝浆料的流变性能，湿泡沫的稳定性以及烧结陶瓷的微观结构和力学性能的影响。使用湿泡沫调节多孔陶瓷的微观结构以获得高强度。对于给定的PAA内容，随着DTAC含量的增加，湿泡沫表现出增加的稳定性。用0.40 wt％的PAA和0.02 wt％的DTAC成功地获得了最稳定的湿泡沫。相应的多孔氧化铝陶瓷具有82％的孔隙率，0.7μm的平均晶粒尺寸和39MPa的抗压强度。但是，对于给定的DTAC含量，随着PAA含量的增加，湿泡沫的稳定性下降。分析了解释这些结果的可能机制。