Pyrotechnic compositions comprising nanostructured crystalline boron phosphide and oxidizer

Patent metadata

Field	Value
Publication number	US-9938203-B2
Application number	US-201715429561-A
Country	US
Kind code	B2
Filing date	Feb 10, 2017
Priority date	Jan 19, 2016
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A novel pyrotechnic composition comprising nanostructured crystalline boron phosphide and oxidizer such as potassium nitrate wherein the crystalline boron phosphide is synthesized by a self-propagating high-temperature reaction. The nanostructured crystalline boron phosphide and oxidizer pyrotechnic composition unexpectedly emits smoke and green flame upon ignition.

First claim

What is claimed is:

1. A mixture comprising crystalline boron phosphide wherein the specific surface area of the crystalline boron phosphide is between 0.05 m 2 /g and 40 m 2 /g and a solid oxidizer, wherein said mixture is a solid pyrotechnic composition.

2. The mixture of claim 1 , wherein the oxidizer is selected from the group consisting of potassium nitrate, potassium chlorate, potassium perchlorate, sodium periodate, and sodium persulfate.

3. The mixture of claim 1 , wherein the oxidizer is potassium nitrate.

4. The mixture of claim 1 , wherein the specific surface area of the crystalline boron phosphide is between 0.5 m 2 /g and 20 m 2 /g.

5. The mixture of claim 1 , wherein the specific surface area of the crystalline boron phosphide is between 4 m 2 /g and 14 m 2 /g.

6. The mixture of claim 1 , wherein ignition of the pyrotechnic composition produces smoke and flame.

7. The mixture of claim 6 , wherein the flame is green.

8. The mixture of claim 1 , wherein the boron phosphide is prepared by a high-temperature synthesis reaction comprising:
a. mixing a composition consisting essentially of boron phosphate and magnesium metal into a homogenous mixture;
b. loading the homogenous mixture into a column structure;
c. packing the homogenous mixture at a pressure of 0 psi to 20,000 psi to form a pellet;
d. igniting the pellet by applying a minimum energy input to initiate a self-propagating high-temperature synthesis reaction of the pellet.

9. The mixture of claim 8 , wherein the minimum energy input is about 0.025% to about 20% of the heat output of the homogenous mixture.

10. The mixture of claim 8 , wherein the homogenous mixture is packed at a pressure of up to about 10,000 psi.

11. The mixture of claim 8 , wherein the homogenous mixture is packed into a powderous column or self-standing pellet form.

12. The mixture of claim 8 , wherein the homogenous mixture is packed into the column without any pressure.

13. The mixture of claim 8 , wherein the mass ratio of the magnesium and boron phosphate is about 1:1.

14. The mixture of claim 8 , wherein the particle size of the magnesium metal is less than 74 microns.

15. A mixture comprising crystalline boron phosphide wherein the specific surface area of the crystalline boron phosphide is between 0.05 m 2 /g and 40 m 2 /g and potassium nitrate, wherein the crystalline boron phosphide is prepared by a self-propagating high-temperature synthesis reaction and wherein ignition of the composition produces smoke and flame.

Assignees

• Us Army

Inventors

• Shaw Anthony P
• Brusnahan Jason
• Poret Jay C
• Morris Lauren A
• Haines Christopher D
• Luan Zhaohua

Classifications

• C06B39/06 Primary

  with free metal, alloy, boron, silicon, selenium or tellurium · CPC title

• C06B45/00

  Compositions or products which are defined by structure or arrangement of component of product (explosive charges of particular form or shape F42B1/00, F42B3/00) · CPC title

• C06B39/00 Primary

  Compositions containing free phosphorus or a binary compound of phosphorus, except with oxygen · CPC title

• C06D3/00

  Generation of smoke or mist (chemical part) (compositions used as biocides, pest repellants or attractants, or plant growth regulators A01N25/18) · CPC title

• C06C15/00

  Pyrophoric compositions; Flints (chemical lighters C06C9/00) · CPC title