Nanoparticles, nanosponges, methods of synthesis, and methods of use

Patent metadata

Field	Value
Publication number	US-9574136-B2
Application number	US-201414475759-A
Country	US
Kind code	B2
Filing date	Sep 3, 2014
Priority date	Feb 10, 2006
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

We disclose novel metallic nanoparticles coated with a thin protective carbon shell, and three-dimensional nano-metallic sponges; methods of preparation of the nanoparticles; and uses for these novel materials, including wood preservation, strengthening of polymer and fiber/polymer building materials, and catalysis.

First claim

What is claimed:

1. A method for making metallic-core carbon-shell nanoparticles, said method comprising the steps of:
(a) impregnating biological fibers with a solution of metal ions in an aqueous or non-aqueous solvent;
(b) removing the solvent, while leaving at least some of the metal ions impregnated in the fibers; and
(c) heating the metal-ion-impregnated fibers in an inert atmosphere or in a vacuum to a temperature that carbonizes at least some of the fibers, that does not vaporize most of the carbon, that reduces at least some of the metal ions to metal particles in a zero oxidation state, and that causes a carbon shell to form around and to completely enclose most of the zero-oxidation-state metal particles; wherein no reducing agent is present during the reduction step, other than said biological fibers themselves; and wherein the reduction of the metal ions to metal particles in a zero oxidation state, and the formation of the carbon shell around the zero-oxidation state metal particles occur simultaneously.

2. A method as recited in claim 1 , wherein the solution of metal ions comprises a metal salt, a metal hydroxide, metal ions complexed by inorganic ligands or metal ions complexed by organic ligands.

3. A method as recited in claim 1 , wherein the biological fibers are selected from the group consisting of cellulose, hemi-cellulose, lignin, cotton, rayon, flax, linen, jute, ramie, sisal, hemp, milkweed, straw, bagasse, hardwood, softwood, lepidopteran silk, hair, wool, spider silk, sinew, and catgut.

4. A method as recited in claim 1 , wherein the metal ions are selected from ions of the group consisting of Group IIA metals (Be, Mg, Ca, Sr, Ba, Ra); Group IIIA metals or semi-metals (B, Al, Ga, In, Tl); Group IVA metals or semimetals (Si, Ge, Sn, Pb); Group VA metals or semi-metals (As, Sb, Bi); Group VIA semi-metals (Te, Po); Group IIIB metals (Sc, Y, La, Ac); Group IVB metals (Ti, Zr, Hf): Group VB metals (V, Nb, Ta); Group VIB metals (Cr, Mo, W); Group VIIB metals (Mn, Tc, Re); Group VIII metals (Fe, Co, In, Ru, Rh, Pd, Os, Ir, Pt); Group IB metals (Cu, Ag, Au); Group IIB metals (Zn, Cd, Hg); Lanthanides (Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu); and Actinides (Th, Pa, U, Np, Pu, Am).

5. A method as recited in claim 1 , wherein the metal ions are selected from ions of the group consisting of Cu, Ag, In, and Gd.

6. A method as recited in claim 1 , wherein the metal ions comprise copper ions.

7. A method as recited in claim 1 , wherein said heating step occurs in a vacuum.

8. A method as recited in claim 1 , wherein said heating step occurs in an inert atmosphere.

9. A method as recited in claim 8 , wherein the inert atmosphere is nitrogen.

Assignees

• Lian Kun
• Univ Louisiana State

Inventors

• Lian Kun

Classifications

• B22F1/102

  Metallic powder coated with organic material · CPC title

• B22F1/107

  containing organic material comprising solvents, e.g. for slip casting · CPC title

• B22F1/054

  Nanosized particles · CPC title

• B22F1/142

  Thermal or thermo-mechanical treatment · CPC title

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title