Patent Application

App. No. 12/326,362

Abstract

Claims (34)

1 . A laminated composite, comprising:

a plurality of stacked prepregs having an interface formed between each pair of adjacent prepregs, each prepreg including a matrix material and reinforcing fibers dispersed therein; and

at least one fibrous veil laminated to at least a portion of at least one of the interfaces, the at least one fibrous veil having nanofibers attached to at least one surface thereof.

2 . The laminated composite of claim 1 wherein the at least one fibrous veil having the nanofibers attached thereto adds a predetermined thickness to the composite.

3 . The laminated composite of claim 2 wherein the predetermined thickness ranges from about 0.01 mm to about 0.1 mm.

4 . The laminated composite of claim 1 wherein the nanofibers are selected from the group consisting of oxidized carbon nanofibers, non-oxidized carbon nanofibers and combinations thereof.

5 . The laminated composite of claim 1 wherein the reinforcing fibers are carbon fibers and the matrix material is a resin, wherein each of the prepregs includes at most 35 weight % of the resin and at least 65 weight % of the carbon fibers, and wherein the carbon fibers are selected from the group consisting of 12K carbon fibers, 24K carbon fibers and combinations thereof.

6 . The laminated composite of claim 1 wherein the at least one fibrous veil is a glass fibrous veil.

7 . The laminated composite of claim 1 wherein an amount of the nanofibers in the laminated composite is less than 2 wt. % of an amount of total matrix material in the laminated composite.

8 . The laminated composite of claim 1 exhibiting an increase in at least one of maximum load, energy to maximum load, and energy to penetration.

9 . The laminated composite of claim 1 wherein each of i) the plurality of prepregs and ii) the at least one fibrous veil includes fibers, wherein such fibers have the same or similar average diameters, and wherein the average diameter ranges from about 7000 nm to about 9000 nm.

10 . The laminated composite of claim 1 wherein each of the plurality of prepregs includes i) fibers selected from carbon fibers, glass fibers, boron fibers, and polymeric fibers, ii) a structure selected from a unidirectional structure, woven fabrics, and multi-axial fabrics, and iii) a resin selected from epoxy resins, phenolic resins, polyester resins, vinyl ester resins, polyimide resins, and thermoplastic resins.

11 . A method of making an impact-resistant laminated composite, the method comprising:

doping a surface of at least one fibrous veil with nanofibers;

laminating the at least one fibrous veil to at least a portion of an interface between a plurality of prepregs, each prepreg including reinforcing fibers in a matrix material; and

molding the laminated plurality of prepregs into the composite.

12 . The method of claim 11 wherein the reinforcing fibers are carbon fibers and the matrix material is a resin, wherein each of the prepregs includes at most 35 weight % of the resin and at least 65 weight % of the carbon fibers, and wherein the carbon fibers are selected from the group consisting of 12K carbon fibers, 24K carbon fibers and combinations thereof.

13 . The method of claim 11 wherein the nanofibers are selected from the group consisting of oxidized carbon nanofibers, non-oxidized carbon nanofibers, polymeric nanofibers, ceramic nanofibers, metallic nanofibers, and combinations thereof.

14 . The method of claim 11 wherein the nanofibers are carbon nanofibers, and wherein doping the surface of the at least one fibrous veil with the carbon nanofibers is accomplished by:

dipping the at least one fibrous veil in a solution containing the carbon nanofibers dispersed therein; and

drying the at least one fibrous veil having the arbon nanofibers attached thereto.

15 . The method of claim 14 wherein the carbon nanofibers are oxidized fibers and wherein the solvent is selected from the group consisting of isopropyl alcohol, acetone, dimethylformamide, methanol, ethanol, and combinations thereof.

16 . The method of claim 14 wherein the carbon nanofibers are non-oxidized fibers and wherein the solution includes isopropyl alcohol, a dispersant, and a mixture of colloidal nanosilica and isopropanol.

17 . A fibrous veil, comprising:

a base including a plurality of fibers, each of the plurality of glass fibers having an average diameter ranging from about 7,000 nm to about 9,000 nm; and

at least one of oxidized and non-oxidized carbon nanofibers attached to at least some of the plurality of glass fibers, wherein the carbon nanofibers have an average diameter ranging from about 60 nm to about 200 nm.

18 . The fibrous veil as defined in claim 17 wherein the plurality of fibers in the base are selected from glass fibers, carbon fibers, and polymeric fibers.

19 . A method of making a nanofiber-doped fibrous veil, the method comprising:

dispersing at least one of oxidized carbon nanofibers and non-oxidized carbon nanofibers into a solution by sonication;

dipping at least one fibrous veil into the dispersed carbon nanofiber solution; and

drying the at least one dipped veil at a predetermined temperature.

20 . The method of claim 19 wherein the oxidized carbon nanofibers are used, and wherein the solution includes one of isopropyl alcohol, acetone, dimethylformamide, methanol, ethanol, or combinations thereof.

21 . The method of claim 19 wherein the non-oxidized carbon nanofibers are used, and wherein the solution includes isopropyl alcohol, a dispersant, and a mixture of colloidal nanosilica and isopropanol.

22 . The method of claim 22 wherein the dispersant is selected from the group consisting of dimethylsulfoxide, N-methyl-2-pyrrolidone, and a nonionic surfactant which includes a hydrophilic polyethylene oxide group.

Assignments (11)