Composite hollow ceramic fibers, precursors for, methods of making the same, and methods of using the same

摘要

A composite hollow ceramic fiber includes a porous hollow core supporting a thin, dense sheath. The non-gas-tight core comprises a first ceramic compound and an interconnecting network of pores. The gas-tight sheath comprises a second ceramic compound. The fiber is made by extruding first and second suspensions of the first and second ceramic compounds in polymeric binders and solvent from a spinnerette and coagulating the nascent hollow fiber to effect phase inversion of the polymeric binders. The resultant green fiber is sintered in a two step process. First, the binder is burned off. Second, the sheath is densified and the second ceramic compound is sinter without fully sintering the first ceramic compound. The first ceramic compound has a melting point higher than that of the second ceramic compound.

主权项

1. A process for making a composite hollow fiber, comprising the steps of:
preparing a first suspension comprising a first polymeric binder, particles of a first ceramic compound, a solvent, and optionally particles of a second ceramic compound; preparing a second suspension comprising a second polymeric binder, particles of the second ceramic compound, the solvent, and optionally particles of the first ceramic compound; providing a spinnerette adapted and configured to continuously extrude one or more nascent hollow fibers comprising a hollow core formed from the first suspension and a sheath surrounding the core formed from the second suspension; immersing the nascent hollow fiber in a liquid coagulant to facilitate phase inversion of the first and second polymeric binders, wherein: the first ceramic compound is a mixed oxide conductor; the second ceramic compound is a mixed oxide conductor; the first ceramic compound is not the same as the second ceramic compound; the first ceramic compound has a melting point higher than that of the second ceramic compound; and the first and second polymeric binders are the same or different.