Synthesis of Cellular Silica Structure Under Microchannel Confinement
Abstract:A silica cellular structure was synthesized as a novel means of enhancing the geometrical surface area of a silicon microchannel with cell diameter of ∼10 m and cell interconnectivity of ∼0.4. Surface-selective infiltration, assembly, and partial sintering of polystyrene microspheres in the microchannel were used as mechanisms to create a sacrificial template. The polymer template was infiltrated with a silica precursor, and the infiltrated structure was dried and calcined at 500°C to remove the polymer phase and subsequently sintered at 1100°C to form dense silica skeleton. Volume shrinkage and crack formation during calcining and sintering of the infiltrated silica structure were strongly influenced by silica particle size in the precursor. In comparison with free-standing cellular specimens prepared by similar template methods, the shrinkage and cracking issues offered an interesting challenge for synthesizing the cellular structure which could be net-shaped into the spatial confinement of the microchannel geometry.
Document Type: Research Article
Affiliations: Department of Chemical, Biomedical, and Materials Engineering, New Jersey Center for MicroChemical Systems, Stevens Institute of Technology, Hoboken, New Jersey
Publication date: January 1, 2007