Control of pore size in ceramic foams: Influence of surfactant concentration

The role of sodium lauryl sulfate (SLS) on pore size of ceramic foams has been investigated using silica foams with 65-70% porosity prepared by a mechanical foaming and gelcasting method. Experiments were carried out to determine bubble size and stability of three-phase foams as well as the pore size of ceramic foams under a range of SLS concentration. Results suggested that pore size of ceramic foams is successfully controlled by changing the SLS concentration of three-phase foam slurries. The controllable range of pore size in this study was roughly 70-150 mu m, which corresponded to the SLS concentration range between 7 x 10(-3) and 7 x 10(-2) M. Furthermore, it was found that the SLS concentration significantly influenced on the foam stability during post-foaming processes as well as the initial bubble size. (C) 2008 Elsevier B.V. All rights reserved.