Fabrication of aligned lamellar porous alumina using directional solidification of aqueous slurries with an applied electrostatic field

Abstract

A novel method combining directional solidification of aqueous slurries with an applied electrostatic field was used to fabricate aligned porous alumina scaffolds. A temperature gradient of 1 °C/mm induced a vertical solidification direction. The angle between the temperature gradient and the applied electrostatic field was 90°. As the electrostatic field intensity was increased from 10 to 100 kV/m, the average lamellar spacing of the porous alumina increased from 53.2 to 278.5 μm, and the angle of the lamellar pore channels changed from 7.5° to 52.6° compared to the direction of the temperature gradient. The direction of the lamellar pore channels was a vector sum of the temperature gradient and the electrostatic field intensity. The fabrication of porous alumina with an ordered, lamellar structure can be readily controlled using directional solidification combined with an applied electrostatic field.