摘要:
Multiphase ceramic nanocomposites having at least three phases are disclosed. Each of the at least three phases has an average grain size less than about 100 nm. In one embodiment, the ceramic nanocomposite is substantially free of glassy grain boundary phases. In another embodiment, the multiphase ceramic nanocomposite is thermally stable up to a temperature of at least about 1500° C. Methods of making such multiphase ceramic nanocomposites are also disclosed.
摘要:
A method of making nanoscale ordered composites of covalent ceramics through block copolymer-assisted assembly. At least one polymeric precursor is mixed with a block copolymer, and self-assembly of the mixture proceeds through an annealing process. During the annealing step, the polymeric precursor cross-links to form a structure robust enough to survive both the order-disorder transition temperature the block copolymer and the pyrolysis process, yielding ordered nanocomposites of high temperature ceramic materials. The method yields a variety of structures and morphologies. A ceramic material having at least one ceramic phase that has an ordered structure on a nanoscale and thermally stable up to a temperature of at least about 800° C. is also disclosed. The ceramic material is suitable for use in hot gas path assemblies, such as turbine assemblies, boilers, combustors, and the like.
摘要:
In some embodiments, the present invention is directed to methods of making structures with complex functional architectures, where such structures generally comprise at least two mesoporous regions comprising different chemical activity, and where such methods afford spatial control over the placement of such regions of differing chemical activity. In some embodiments, the present invention is also directed to the structures formed by such methods, where such structures are themselves novel.
摘要:
A ceramic structure having a scaffold with at least one opening and at least one porous filler material at least partially filling the at least one opening is described. The porous ceramic filler includes a plurality of pores. The pores have an average size in a range from about 2 nm to about 100 nm. The plurality of pores includes at least one pore architecture. For each pore architecture, the average pore size does not vary by more than about 100% when the average pore size is in a range from about 2 nm to about 50 nm, and the average pore size does not vary by more than about 50% when the average pore size is greater than about 50 nm. The plurality of pores includes at least two pore architectures when the porous filler material is silica. Also described is a method of making the ceramic structure.
摘要:
A long-lived phosphor composition is provided, along with methods for making and using the composition. More specifically, in one embodiment, the phosphor comprises a material having a formula of Ax-y-zAl2-m-n-o-pO4:Euy, REz, Bm, Znn, Coo, Scp. In this formula, A may be Ba, Sr, Ca, or a combination of these metals, x is between about 0.75 and 1.3, y is between about 0.0005 and 0.1, z is between about 0.0005 and 0.1, m is between about 0.0005 and 0.30, n is between about 0.0005 and 0.10, o is between about 0 and 0.01 and p is between about 0 and 0.05. RE is Dy, Nd, or a combination thereof. In another embodiment, methods are provided for making persistent phosphors comprising the formulations above. Other embodiments provide applications for such a phosphor, comprising uses in toys, emergency equipment, clothing, and instrument panels, among others.