Curved nanofiber products and applications thereof

• US 10,099,165 B2
• Filed: 12/21/2015
• Issued: 10/16/2018
• Est. Priority Date: 12/06/2012
• Status: Active Grant

• Current Assignee: Research Triangle Institute
• Original Assignee: Research Triangle Institute
• Inventors: Walls, Howard Jerome, Newsome, Randall J., Clayton, Anthony Clint, Yaga, Robert W., Ensor, David Samuel
• Primary Examiner(s): McKenzie, T. Bennett
• Application Number:
  US14/975,978
• Publication Number:
  US 20160243480A1
• Time in Patent Office: 1,030 Days
• Field of Search: 55500
• CPC Class Codes: A62B 18/02 Masks gas-masks for animals A62B18/06; masks for welders A61F9/06
• CPC Class Codes: A62B 18/04 Gas helmets
• CPC Class Codes: A62B 18/084 Means for fastening gas-masks to heads or helmets
• CPC Class Codes: A62B 23/025 the filter having substantially the shape of a mask surgical face masks A41D13/11
• CPC Class Codes: B01D 46/0001 Making filtering elements
• CPC Class Codes: B01D 46/103 Curved filtering elements
• CPC Class Codes: B01D 46/546 using nano- or microfibres
• CPC Class Codes: D01D 5/0076 characterised by the collecting device, e.g. drum, wheel, endless belt, plate or grid D01D5/0046 takes precedence
• CPC Class Codes: D10B 2509/00 Medical; Hygiene

Abstract

A filtration device including a contoured support having 1) an interior surface, 2) an outside peripheral surface spaced farther from a center of the contoured support than the interior surface, and 3) a rim enclosed and sealed to a perimeter of the contoured support. The filtration device includes macroscopic openings in the contoured support extending from the interior surface to the outside peripheral surface, and a plurality of nanofibers having diameters less than 1 micron. The nanofibers are disposed on the outside peripheral surface of the contoured support, and cover the macroscopic openings to form a filtration medium on the contoured support.

Claims

1. A method for producing conformal shaped fiber mats, comprising:

feeding a substance from which a fibrous material is to be composed to an electrospinning extrusion element;

extruding the substance through the electrospinning extrusion element;

collecting the fibrous material on a contoured support disposed on a tilt axis tilted relative to the electrospinning extrusion element; and

moving at least one of the electrospinning extrusion element and the contoured support to form the fibrous materials on the contoured support such that at least a tilt angle of the contoured support relative to the electrospinning extrusion element changes during the collecting while the contoured support rotates about the tilt axis of the contoured support,

wherein

the moving comprises tilting the electrospinning extrusion element relative to the contoured support, and

the tilting comprises tilting the electrospinning extrusion element relative to the contoured support so that a time spent at plural stepped tilt angles is longer for greater tilt angles than smaller tilt angles of the electrospinning extrusion element relative to the contoured support.

2. The method of claim 1, wherein the moving comprises forming the fibrous material uniformly on the contoured support.

3. The method of claim 1, wherein the extruding the substance comprises applying an electric field to the electrospinning extrusion element to extract the substance from the electrospinning extrusion element.

4. The method of claim 3, wherein applying an electric field comprises applying said electric field to an electrospinning spinneret of the electrospinning extrusion element.

5. The method of claim 1, wherein the moving occurs during active positioning of the contoured support relative to the electrospinning extrusion element.

6. The method of claim 1, wherein the moving comprises providing substantially equal deposition and coverage of nanofibers across the surface of the contoured support.

7. The method of claim 1, wherein the electrospinning extrusion element is fixed while the contoured support is moved relative to the electrospinning extrusion element.

8. The method of claim 1, wherein said tilting comprises tilting the electrospinning extrusion element relative to the contoured support as a function of the tilt angle and time such that the tilt angle varies temporally relative to the contoured support.

9. The method of claim 1, wherein said tilting comprises tilting the electrospinning extrusion element relative to the contoured support so that a distance between the electrospinning extrusion element and a surface of the contoured support remains constant as the contoured support is tilted.

10. The method of claim 1, further comprising providing an auxiliary electric field to promote uniform deposition on the contoured support.

11. The method of claim 1, wherein the contoured support is shaped as a dome.

12. The method of claim 1, further comprising:

supplying a process gas during said extruding; and

drawing the process gasses through the contoured support.

13. The method of claim 12, wherein supplying a process gas comprises supplying CO₂ gas.

14. The method of claim 13, further comprising monitoring a pressure drop across the contoured support.

15. The method of claim 1, further comprising controlling at least one of a temperature and a humidity.

16. The method of claim 1, wherein collecting the contoured support comprises a metallic mesh.

17. The method of claim 16, further comprising applying a negative bias to the metallic mesh.

18. The method of claim 1, wherein the extruding the substance through the electrospinning extrusion element comprises electrospinning nanofibers onto the contoured support.