Method of making flexible ceramic fibers and polymer composite
AssigneeEyrekjiute Holding B.V.
InventorsGerard CADAFALCH GAZQUEZ, Roger Brunet Espinosa
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Abstract
The present application discloses and claims a method to make a flexible ceramic fibers (Flexiramics™) and polymer composites. The resulting composite has an improved mechanical strength (tensile) when compared with the Flexiramics™ respective the nanofibers alone. Additionally a composite has better properties than the polymer alone such as lower fire retardancy, higher thermal conductivity and lower thermal expansion. Several different polymers can be used, both thermosets and thermoplastics. Flexiramics™ has unique physical characteristic and the composite materials can be used for numerous industrial and laboratory applications.
Claims13
A process for making a flexible composite material comprising flexible ceramic nanofibers and a polymer, the process of making flexible ceramic nanofibers comprising the steps of:
- a) preparing a ceramic fiber precursor solution comprising
- (i) a dissolved metal precursor for ceramic selected from the group consisting of metallic ions and metal containing polymer and selected from the group consisting of Si4+, Zr4+, Ti4+, Y3+, Al3+, Zn2+, Mg2+, Pb4+, Ni2+, Sr2+, Ca2+, La3+;
- (ii) a polymer to increase the precursor solution viscosity, with the solid content of the precursor solution (polymer plus precursor) being above 5% by weight in order to obtain the required deposition, and
- (iii) solvent capable of providing the precursor solution a sufficiently high evaporation rate;
- b) allowing the dissolved metal precursors for ceramic to form a final metal oxide also known as ceramic;
- c) maintaining the precursor solution viscosity between 0.01 and 1000 Pascal-second at a shear rate of 0.01 to 1 s−1 in order to spin usable fibers;
- d) spinning the precursor solution by forcespinning, electrospinning and blowspinning wherein the spinning parameters are tunable so that the spinning step results in polymeric fibers and with the spinning parameters being adaptable to each precursor solution;
- e) annealing the polymeric fibers obtained from the spinning process, the polymeric fibers comprising the metal precursors for ceramic, until all the organic content is burned out and the metallic ion oxidizes to form a ceramic;
- f) tuning and calibrating annealing parameters comprising heating and cooling rates, annealing temperature and dwell time consistent with a trapezium shaped thermal profile so a crystallinity comprising a crystal size of 1 to 100 nm and a smoothness of 0.05 to 5 nm of Rq of the resulting 20 to 10000 nm thick fibers is obtained, the annealing parameters being distinct and specific with respect to each material composition;
- and
- g) setting the annealing temperature above the ceramic fiber crystallization point resulting in the formation of ceramic material.
Dependencies are inferred from the claim text.