Extruded ceramic nanofibers and derived materials
AssigneeThe United States of America as represented by the Secretary of the Air Force
InventorsMatthew B. Dickerson, John J. Bowen
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Abstract
The present invention relates to gels and processes for making bundles of aligned ceramic nanofibers, ceramic nanostructures made by such processes, and methods of using such ceramic nanostructures. Such process is templated via block copolymer self-assembly but does not require any post processing thermal and/or solvent annealing steps. As a result, such process is significantly more efficient and scalable than other processes that are templated via block copolymer self-assembly. The resulting fibers are aligned according to the direction of deposition, making steps where individual fibers are bundled unnecessary.
Claims11
A process of making bundles of aligned ceramic fibers, said process comprising pyrolyzing a cured extruded filament under an inert gas, said cured extruded filament being produced by extruding a gel to form an extruded filament and then thermally curing said extruded filament to form a cured extruded filament, said gel comprising, based on total gel weight:
- a) from about 11% to about 40%, of a block co-polymer having a weight average molecular weight of from about 53,000 Da to about 77,000 Da, said block co-polymer having Structure 1 below:
- wherein the total weight ratio of
- in said block co-polymer is from about 1:3 to about 3:1;
- b) from about 8% to about 34% of a pre-ceramic polymer having a weight average molecular weight of from about 500 Da to about 100,000 Da, said pre-ceramic polymer comprising units having Structure 2 below:
- wherein the weight ratio of the moiety having indice x to the moiety having indice y is from about 10:1 to about 1:100;
- c) from about 30% to about 50% of an amphilic solvent, and
- d) from about 13% to about 25% of a plasticizer;
- with the proviso that the combined weight percentage of said block co-polymer, pre-ceramic polymer, amphilic solvent and plasticizer does not exceed 100%.
Dependencies are inferred from the claim text.