Ferrite compositions

Abstract

Ferrite compositions, particularly ferrite coated substrates and more particularly fibre plys coated with ferrites in fibre reinforced polymer composites (FRPC), and composites with a plurality of functionalised fibre layers, include a magnetic ferrite composition for coating a substrate, said composition comprising a resin, and dispersed therein ferrite particulates, wherein said ferrite particulates have an average longest dimension of less than 500 nm. The composition may be used to provide a ferrite composite structure comprising at least one fibre ply, with at least one layer of a magnetic ferrite composition disposed thereon, wherein said ply is substantially encapsulated in a binder matrix to form a fibre reinforced polymer composite.

Claims

1. A method of manufacturing a ferrite composite structure comprising at least one glass fibre ply, the method comprising: causing heating of the at least one glass fibre ply to a softening point of the at least one glass fiber ply, thereby forming at least one softened glass fiber ply; embedding a magnetic ferrite powder in the at least one softened glass fibre ply, wherein particles of the magnetic ferrite powder have an average longest dimension of less than 500 nm; causing the at least one softened glass fibre ply to cool, thereby forming at least one cooled glass fibre ply; encapsulating the at least one cooled glass fibre ply in a binder matrix, such that the binder matrix directly contacts the at least one cooled glass fibre ply; and causing a cure of the binder matrix, thereby forming a fibre-reinforced composite.

2. The method of claim 1, wherein the magnetic ferrite powder is embedded in the at least one softened glass fibre ply by spraying the magnetic ferrite powder.

3. The method of claim 1, further comprising shaping the fibre-reinforced composite to form a structural panel.

4. The method of claim 1, wherein at least 40% v/v of the magnetic ferrite powder is embedded in the at least one softened glass fibre ply.

5. The method of claim 1, wherein the magnetic ferrite powder is dispersed within a solvent.

6. The method of claim 1, wherein the average longest dimension of the particles of the magnetic ferrite powder is in a range from 50 to 150 nm.

7. The method of claim 1, wherein said magnetic ferrite powder is embedded in the at least one softened glass fibre ply in an array pattern.

8. A method of manufacturing a ferrite composite structure comprising at least one glass fibre ply, the method comprising: causing heating of the at least one glass fibre ply to a softening point of the at least one glass fiber ply, thereby forming at least one softened glass fiber ply; embedding a magnetic ferrite composition in the at least one softened glass fibre ply, the magnetic ferrite composition comprising a resin and a plurality of ferrite particulates, wherein the ferrite particulates of the magnetic ferrite composition have an average longest dimension of less than 500 nm; causing the at least one softened glass fibre ply to cool, thereby forming at least one cooled glass fibre ply; encapsulating the at least one cooled glass fibre ply in a binder matrix, such that the binder matrix directly contacts the at least one cooled glass fibre ply; and causing a cure of the binder matrix, thereby forming a fibre-reinforced composite.

9. The method of claim 8, wherein the magnetic ferrite composition is embedded in the at least one softened glass fibre ply by spraying the magnetic ferrite composition.

10. The method of claim 8, further comprising shaping the fibre-reinforced composite to form a structural panel.

11. The method of claim 8, wherein at least 40% v/v of the ferrite particulates are embedded in the at least one softened glass fibre ply.

12. The method of claim 8, wherein the average longest dimension of the ferrite particulates is in a range from 50 to 150 nm.

13. The method of claim 8, wherein said magnetic ferrite composition is embedded in the at least one softened glass fibre ply in an array pattern.

14. A method of manufacturing a ferrite composite structure comprising at least one glass fibre ply, the method comprising: coating a magnetic ferrite powder over at least a portion of the at least one glass fibre ply, wherein particles of the magnetic ferrite powder have an average longest dimension of less than 500 nm; causing the at least one glass fibre ply having the magnetic ferrite powder to cool, thereby forming at least one cooled glass fibre ply; encapsulating the at least one cooled glass fibre ply in a binder matrix, such that the binder matrix directly contacts the at least one cooled glass fibre ply; and causing a cure of the binder matrix, thereby forming a fibre-reinforced composite.

15. The method of claim 14, wherein the magnetic ferrite powder is coated on the at least one glass fibre ply by spraying the magnetic ferrite powder.

16. The method of claim 14, further comprising shaping the fibre-reinforced composite to form a structural panel.

17. The method of claim 14, wherein at least 40% v/v of the magnetic ferrite powder is embedded in the at least one glass fibre ply.

18. The method of claim 14, wherein the magnetic ferrite powder is dispersed within a solvent.

19. The method of claim 14, wherein the average longest dimension of the particles of the magnetic ferrite powder is in a range from 50 to 150 nm.

20. The method of claim 14, wherein said magnetic ferrite powder is coated on the at least one glass fibre ply in an array pattern.

Description

(1) Exemplary embodiments of the device in accordance with the invention will now be described with reference to the accompanying drawings in which:

(2) FIGS. 1a and 1b show a composite structure, and ferrite composition

(3) FIG. 2 shows a patch antenna pattern disposed on the surface of a substrate.

(4) FIG. 1a shows an example of a composite structure depicted generally at 10, comprising a nickel ferrite fibre ply 11, optionally a standard fibre ply 14, optionally a metallic coated fibre ply (non ferrite) 15. The fibre plys (11, 14, 15) are encapsulated in a binder matrix 12 to form the composite structure 10. The binder matrix 12 may also contain filler particulates 16, which may also be nickel ferrite particulates.

(5) The enlarged cut portion shows the nickel ferrite fibre ply 11, which is formed from a standard fibre ply 14a, which is impregnated with a ferrite composition 17 and optionally a surface coating 17a of a ferrite composition. FIG. 1b shows a ferrite composition 17 comprising a resin 18 loaded with ferrite particulates 19.

(6) The resin 18 and binder matrix 12, may be independently selected resins or may be selected from the same resin systems. In a preferred arrangement, the ferrite composition 17 may also be selected as the preferred binder matrix material 12, such that the binder matrix 12 comprises ferrite particulates which are not disposed on the fibre ply.

(7) The layers are not necessarily planar. Non-planar configurations may be employed, for example, to provide a curved or even a generally tubular device structure, or to provide devices which can be shaped to any currently existing shaped panel. The structures of the invention are well suited for such configurations.

(8) FIG. 2 shows a top view of a patch antenna 21, which is formed from a substrate 23, which may be a fibre ply, with a disposed ferrite composition 22 in the form of an array pattern 24.