Method of manufacturing tin-doped indium oxide nanofibers

Patent metadata

Field	Value
Publication number	US-9670598-B2
Application number	US-201514673130-A
Country	US
Kind code	B2
Filing date	Mar 30, 2015
Priority date	Mar 30, 2015
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A method of making indium tin oxide nanofibers includes the step of mixing indium and tin precursor compounds with a binder polymer to form a nanofiber precursor composition. The nanofiber precursor composition is co-formed with a supporting polymer to form a composite nanofiber having a precursor composition nanofiber completely surrounded by the supporting polymer composition. The supporting polymer composition is removed from the composite nanofiber to expose the precursor composition nanofiber. The precursor composition nanofiber is then heated in the presence of oxygen such as O 2 to form indium tin oxide and to remove the binder polymer to form an indium tin oxide nanofiber. A method of making metal oxide nanofibers is also disclosed.

First claim

We claim:

1. A method of making indium tin oxide nanofibers, comprising the steps of:
mixing indium and tin precursor compounds with a binder polymer to form a nanofiber precursor composition;
co-forming the nanofiber precursor composition with a supporting polymer to form a composite nanofiber comprising a precursor composition nanofiber completely surrounded by the supporting polymer composition;
removing the supporting polymer composition from the composite nanofiber to expose the precursor composition nanofiber;
heating the precursor composition nanofiber in the presence of oxygen to form indium tin oxide and to remove the binder polymer to form an indium tin oxide nanofiber.

2. The method of claim 1 , wherein the precursor composition nanofiber is between 100 nm and 20 μm in width.

3. The method of claim 1 , wherein the composite nanofiber is greater than 10 μm in width.

4. The method of claim 1 , wherein the indium tin oxide nanofiber is less than 100 μm.

5. The method of claim 1 , further comprising the step of stretching the nanofiber precursor to produce indium tin oxide nanofiber to a width of less than 1 μm.

6. The method of claim 1 , wherein the indium precursor compound is at least one selected from the group consisting of Indium acetate (In(CH 3 COO) 3 , Indium trihalide [e.g., Indium trichloride (InCl 3 ), Indium tribromide (InBr 3 )] Indium nitrate (In(NO 3 ) 3 ), Indium sulfate (In 2 (SO 4 ) 3 ), and Indium hydroxide (In(OH) 3 ).

7. The method of claim 1 , wherein the tin precursor compound is at least one selected from the group consisting of Tin(II) 2-ethylhexanoate ([CH 3 (CH 2 ) 3 CH(C 2 H 5 )CO 2 ]2Sn), Tin Chloride (SnCl 2 .2H 2 O), Tin Bromide (SnBr 2 ), Tin Pyrophsophate Sn 2 P 2 O 7 , and Tin Nitrate Sn(NO 3 ) 4 .

8. The method of claim 1 wherein the binder polymer comprises at least one selected from the group consisting of polyethylene, polyethelene oxide polyvinyl acetate, poly lactic acid, polyester, polypropylene, and ethylene-propylene copolymers.

9. The method of claim 1 , wherein the supporting polymer comprises at least one selected from the group consisting of polylactic acid, polyethelene, polyesters, polystyrene, and polyurethane.

10. The method of claim 1 , wherein the step of removing the supporting polymer composition comprises heating.

11. The method of claim 10 , wherein the heating to remove the supporting polymer composition is to a temperature sufficient to melt, pyrolize, or combust the supporting polymer composition, but not the binder polymer.

12. The method of claim 1 , wherein the step of removing the supporting polymer composition comprises the step of contacting the supporting polymer with a removal composition.

13. The method of claim 12 , wherein the removal composition comprises at least one selected from the group consisting of a solvent for the supporting polymer, and a composition reactive with the supporting polymer and unreactive with the binder polymer.

14. The method of claim 1 , wherein the step of heating the precursor nanofiber to form indium tin oxide comprises heating the precursor composition nanofiber to between 300° C. and 1000° C.

15. The method of claim 14 wherein the step of heating the precursor composition nanofiber to form indium tin oxide comprises increasing the temperature of the precursor composition nanofiber at a ramp rate of between 1° C./min. and 20° C./min.

16. The method of claim 1 , wherein the co-forming step is melt spinning.

17. The method of claim 1 , further comprising the step of forming a plurality of the indium tin oxide nanofibers into a web.

18. The method of claim 1 , wherein the mixing step comprises at least one selected from the group consisting of melt mixing and solution mixing.

19. The method of claim 1 , wherein the co-forming step comprises multicomponent spinning.

20. The method of claim 19 , wherein the multicomponent spinning comprises at least one selected from the group consisting of melt spinning, gel spinning, and solution spinning.

21. The method of claim 1 , further comprising the step of, after the formation of indium tin oxide, treating the indium tin oxide nanofiber to render the indium tin oxide nanofiber more electrically conductive.

22. The method of claim 21 , wherein the treating is with heat and H 2 .

23. The method of claim 1 , wherein the co-forming step comprises forming the precursor composition nanofiber into a desired shape.

Assignees

• Ut Battelle Llc

Inventors

• Ozcan Soydan
• Naskar Amit K

Classifications

• C01P2004/90

  Other morphology not specified above · CPC title

• C01P2004/16

  Nanowires or nanorods, i.e. solid nanofibres with two nearly equal dimensions between 1-100 nanometer · CPC title

• D01D5/36

  Matrix structure; Spinnerette packs therefor · CPC title

• D01F9/08 Primary

  of inorganic material (working or processing of metal wire B21F; from softened glass, minerals or slags C03B37/00) · CPC title

• D01D5/34

  Core-skin structure; Spinnerette packs therefor · CPC title