Pyrophoric foam materials and methods of making the same
An in-situ process for synthesizing highly pyrophoric foam materials using metal and carbon precursors wherein the precursors serve as foaming and activating agents to disperse and lock nano-sized metal particles within a rigid porous carbon matrix. The resulting carbon matrix is also pyrophoric.
1. A process for preparing a pyrophoric porous foam material comprising:
(a) mixing a precursor pyrophoric composition comprising, precursor metal molecules wherein said precursor metal molecules is one or more of a member selected from the group consisting of an inorganic metal salt or organometallic compound, a carbon precursor, wherein the carbon precursor is selected from the group consisting of resole phenolic resin, petroleum mesopitch, and carbohydrate, and a solvent to form a homogenous mixture;
(b) casting the homogenous mixture of step (a) into a geometric shape;
(c) curing the product of step (b) at above ambient temperature; and
(d) activating the product of step (c) by heating said product under an inert or reducing atmosphere to carbonize the carbon matrix and uniformly embed the metal nanoparticles in said matrix; and
(e) wherein the steps of mixing, casting, and curing are performed in-situ.
2. The process of claim 1 , wherein the inorganic metal salt or organometallic compound comprises metal ions or metal elements of iron, aluminum, bismuth, boron, calcium, hafnium, iron, magnesium, manganese, tin, titanium, cobalt, uranium, zinc, and/or zirconium.
3. The process of claim 1 , wherein the inorganic metal salt is aluminum sulfate.
4. The process of claim 1 , wherein the inorganic metal salt is a metal dihydrate.
5. The process of claim 4 , wherein the metal dihydrate is iron oxalate dihydrate.
6. The process of claim 1 , wherein the organometallic compound is triethylaluminum or ferrocene.
7. The process of claim 1 , wherein the carbon precursor is resole phenolic resin.
8. The process of claim 1 , wherein the solvent is ethanol.
9. The process of claim 1 , wherein curing the product of step (b) comprises heating said product to about 50° C. to about 200° C.
10. The process of claim 1 , wherein the inert or reducing atmosphere is a mixture of hydrogen and argon gas or hydrogen and nitrogen gas.
11. The process of claim 1 , wherein the inert or reducing atmosphere is at least 5% hydrogen in argon or 5% hydrogen in nitrogen gas.
12. The process of claim 1 , wherein activating the product of step (c) is performed by heating said product at about 400° C. to about 800° C.
13. The process for claim 1 wherein the geometric shapes of step (b) is selected from the group consisting of thin disks, beads, granulars, monoliths, and pellets.
14. An process for preparing a pyrophoric porous foam material comprising:
(a) mixing a pyrophoric composition consisting essentially of iron oxalate dihydrate, resole phenolic resin, and ethanol into a homogenous mixture;
(b) casting the homogenous mixture;
(c) curing said homogenous mixture at above room temperature; and
(d) activating the cured homogenous mixture by heating said cured homogenous mixture at about 400° C. to about 800° C. in the presence of an inert or reducing atmosphere.
15. The process of claim 14 wherein the steps of mixing, casting, and curing are performed in-situ.
16. The process of claim 14 wherein the inert or reducing atmosphere consists essentially of at least one gas selected from the group of hydrogen, nitrogen, an argon.