粒子稳定型泡沫浆料及多孔氧化铝陶瓷的制备

采用短链两亲分子戊酸修饰氧化铝颗粒,使其部分具有的疏水性,在机械搅拌的作用下,形成了粒子稳定型泡沫(particle-stabilized foam),制备了一种新型的超稳定陶瓷泡沫浆料.研究了这种浆料的pH值对发泡率的影响,发现在pH值为4.8附近,戊酸对氧化铝颗粒的表面修饰作用最好,发泡程度最大;通过改变pH值,能够调整浆料的发泡程度,以满足不同应用领域对发泡率的要求.采用凝胶注模成型工艺,利用粒子稳定型泡沫浆料,成功制备了具有相互连通气孔-窗口(cell-window)结构的多孔陶瓷,由于其致密的支架结构使其具有高抗压强度,对于气孔率为85%的多孔氧化铝,其抗压强度在8MPa以上.

PARTICLE-STABILIZED FOAMS SLURRY AND MANUFACTURING OF POROUS ALUMINA CERAMICS

A novel ultrastable particle-stabilized foam slurry was prepared by alumina particles modified by the short amphiphiles to make them partially lyophobic and to initiate direct foaming with vigorous stirring. The foaming rate is different at different pH values, and the optimal pH value is about 4.8. Valeric acid has the most modified action on the surface of alumina particles and the larger foaming action. Because of their dense struts, the porous alumina ceramics with connected pores and cell-window structure manufactured from the ultrastable foam slurry have high compression strength. The compression strength of the porous alumina with 85% porosity is above 8 MPa.