Preparação e caracterização estrutural de materiais cerâmicos obtidos via processo freeze-casting

Abstract

Porous materials have attracted great attention as a new class of materials with a wide range of applications, including membranes for gas separation and desalination. It is well established that the properties of porous ceramic materials are related to the manufacturing process. Thus, the knowledge and control of the process parameters is a key issue for tailoring the properties of these materials. In this work alumina-based supports were prepared using tert-butyl alcohol as the solvent and citric acid as the dispersant. When the solid loading was increased from 15 to 30 vol%, the total porosity of the alumina ceramic decreased linearly from 73 to 48%. The samples showed a closed porosity below 2%. The flexural strength of these materials ranged from 3.6 ± 0.7 to 21.9 ± 0.6 MPa. The freeze-cast porous alumina was examined by scanning electron microscopy, and X-ray microtomography. The obtained samples exhibited a well-connected and ordered pore network. The results obtained in this work confirm the versatility of freeze-casting process for preparing porous ceramic materials.