Synthesis of magnetic, dielectric or phosphorescent NANO composites

• US 7,431,862 B2
• Filed: 04/30/2004
• Issued: 10/07/2008
• Est. Priority Date: 04/30/2004
• Status: Expired due to Term

• Current Assignee: Flextronics International USA Incorporated (Flex, Ltd.)
• Original Assignee: ColdWatt, Inc. (Flex, Ltd.)
• Inventors: Mehrotra, Vivek, Goldberg, Ira
• Primary Examiner(s): Koslow; C. Melissa
• Application Number:
  US10/837,552
• Publication Number:
  US 20050245658A1
• Time in Patent Office: 1,621 Days
• Field of Search: None
• US Class Current: 252/62.54
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 3/24 Acids; Salts thereof C08K3/16 takes precedence

Abstract

A method of forming nano composites within a polymer structure comprises exposing a wettable polymer having ion-exchangeable groups pendant therefrom to an aqueous solution of a soluble salt containing metal ions, the metal ions replacing, by ion exchange, the pendant groups on the polymer. After ion exchange the polymer is exposed to a reducing agent forming metal oxides trapped within the polymer structure.

Claims

1. A nanocomposite comprising a metal oxide and an ionomeric or cellulosic polymer matrix, wherein said metal oxide is formed as phosphorescent ZnO nanoparticles including an ion exchange and precipitation procedure within said ionomeric or cellulosic polymer matrix.

2. The nanocomposite as recited in claim 1 wherein said ionomeric or cellulosic polymer matrix comprises a polymer matrix having ion exchange groups.

3. The nanocomposite as recited in claim 2 wherein said polymer matrix having ion exchange groups comprises sulfonated polymer chains with hydrogen ions balancing a charge.

4. The nanocomposite as recited in claim 2 wherein a volume fraction of nanoparticles within said polymer matrix is controlled by repeating said ion exchange and precipitation procedure.

5. The nanocomposite as recited in claim 1 wherein said cellulosic polymer matrix comprises one of cotton, linen, rayon and paper products.

6. The nanocomposite as recited in claim 1 wherein said cellulosic polymer matrix is formed by oxidizing hydroxyl groups to carboxylate groups followed by an ion exchange and precipitation procedure within said cellulosic polymer matrix.

7. A method of forming a nanocomposite, comprising:

contacting an ionomeric or cellulosic polymer matrix with a solution of zinc ions by an ion exchange and precipitation procedure, thereby attaching said zinc ions to said ionomeric or cellulosic polymer matrix; and

oxidizing said zinc ions with an alkali base, thereby dispersing a zinc oxide as phosphorescent ZnO nanoparticles throughout said ionomeric or cellulosic polymer matrix.

8. The method as recited in claim 7 wherein said ionomeric or cellulosic polymer matrix comprises a polymer matrix having ion exchange groups.

9. The method as recited in claim 8 wherein said polymer matrix having ion exchange groups comprises sulfonated polymer chains with hydrogen ions balancing a charge.

10. The method as recited in claim 8 wherein a volume fraction of nanoparticles within said polymer matrix is controlled by repeating said ion exchange and precipitation procedure.

11. The method as recited in claim 7 wherein said cellulosic polymer matrix comprises one of cotton, linen, rayon and paper products.

12. The method as recited in claim 7 wherein said cellulosic polymer matrix is formed by oxidizing hydroxyl groups to carboxylate groups followed by said ion exchange and precipitation procedure within said cellulosic polymer matrix.

13. A nanocomposite comprising a metallic alloy and an ionomeric or cellulosic polymer matrix, wherein said metallic alloy is formed as nanoparticles including an ion exchange and precipitation procedure within said ionomeric or cellulosic polymer matrix, wherein said metallic alloy is magnetic, phosphorescent or magnetodielectric and is selected from the group consisting of Ni—

Fe, Sm—

Co, Mn—

Fe, Co—

Fe, and combinations thereof.

14. The nanocomposite as recited in claim 13 wherein said metallic alloy is formed by reducing metal ions with a reducing agent, thereby dispersing said metallic alloy as nanoparticles throughout said ionomeric or cellulosic polymer matrix.

15. The nanocomposite as recited in claim 13 wherein said ionomeric or cellulosic polymer matrix comprises a polymer matrix having ion exchange groups.

16. The nanocomposite as recited in claim 15 wherein said polymer matrix having ion exchange groups comprises sulfonated polymer chains with hydrogen ions balancing a charge.

17. The nanocomposite as recited in claim 15 wherein a volume fraction of nanoparticles within said polymer matrix is controlled by repeating said ion exchange and precipitation procedure.

18. The nanocomposite as recited in claim 13 wherein said cellulosic polymer matrix comprises one of cotton, linen, rayon and paper products.

19. The nanocomposite as recited in claim 13 wherein said cellulosic polymer matrix is formed by oxidizing hydroxyl groups to carboxylate groups followed by said ion exchange and precipitation procedure within said cellulosic polymer matrix.

20. A method of forming a nanocomposite, comprising:

contacting an ionomeric or cellulosic polymer matrix with a solution of first and second metal ions, thereby attaching said first and second metal ions to said ionomeric or cellulosic polymer matrix; and

reducing said first and second metal ions with a reducing agent, thereby dispersing a metallic alloy as nanoparticles throughout said ionomeric or cellulosic polymer matrix, wherein said metallic alloy is magnetic, phosphorescent or magnetodielectric and is selected from the group consisting of Ni—

Fe, Sm—

Co, Mn—

Fe, Co—

Fe, and combinations thereof.

21. The method as recited in claim 20 wherein said reducing agent comprises NaBH₄.

22. The method as recited in claim 20 wherein said ionomeric or cellulosic polymer matrix comprises a polymer matrix having ion exchange groups.

23. The method as recited in claim 22 wherein said polymer matrix having ion exchange groups comprises sulfonated polymer chains with hydrogen ions balancing the charge.

24. The method as recited in claim 22 wherein a volume fraction of nanoparticles within said polymer matrix is controlled by repeating said ion exchange and precipitation procedure.

25. The method as recited in claim 20 wherein said cellulosic polymer matrix comprises one of cotton, linen, rayon and paper products.

26. The method as recited in claim 20 wherein said cellulosic polymer matrix is formed by oxidizing hydroxyl groups to carboxylate groups followed by said ion exchange and precipitation procedure within said cellulosic polymer matrix.