Electrospray/electrospinning apparatus and method

• US 7,762,801 B2
• Filed: 04/08/2004
• Issued: 07/27/2010
• Est. Priority Date: 04/08/2004
• Status: Active Grant

• Current Assignee: Research Triangle Institute
• Original Assignee: Research Triangle Institute
• Inventors: Ensor, David S., Andrady, Anthony L.
• Primary Examiner(s): Tolin; Michael A
• Application Number:
  US10/819,942
• Publication Number:
  US 20050224998A1
• Time in Patent Office: 2,301 Days
• Field of Search: 425/72.2, 425/174.8 E, 425/382.2, 425/467
• US Class Current: 425/72.2
• CPC Class Codes: D01D 5/0069 characterised by the spinning section, e.g. capillary tube, protrusion or pin
• CPC Class Codes: D01D 5/0092 characterised by the electrical field, e.g. combined with a magnetic fields, using biased or alternating fields

Abstract

Apparatus and method for producing fibrous materials in which the apparatus includes an enclosure having an inlet configured to receive a substance from which the fibrous materials are to be composed, a common electrode disposed in the enclosure, and plural extrusion elements provided in a wall of the enclosure opposite the common electrode so as to define between the plural extrusion elements and the common electrode a space in communication with the inlet to receive the substance in the space. In the method, a substance from which the fibrous materials are to be composed is fed to the enclosure having the plural extrusion elements, a common electric field is applied to the extrusion elements in a direction in which the substance is to be extruded, the substance is extruded through the extrusion elements to tips of the extrusion elements, and the substance is electrosprayed from the tips to form the fibrous materials.

Claims

1. An apparatus for producing fibers, comprising:

an enclosure having an inlet configured to receive a substance from which the fibers are to be composed, said substance to be in contact with the enclosure;

a common electrode disposed inside said enclosure;

at least one extrusion element including at least one frit segment entirely covering an opening in the extrusion element; and

a substance-receiving space between the extrusion element and the common electrode and in communication with said inlet to receive said substance in said space.

2. The apparatus of claim 1, wherein said common electrode is located equidistant from said plural extrusion elements.

3. The apparatus of claim 1, further comprising:

an exterior electrode located outside the enclosure such that upon application of a voltage across that common and exterior electrodes an electric field is produced extending from said common electrode through an enclosure wall and to said exterior electrode.

4. The apparatus of claim 3, wherein said exterior electrode is configured to collect said fibers.

5. The apparatus of claim 3, further comprising:

a collecting mechanism disposed between the enclosure and the exterior electrode and configured to collect said fibers.

6. The apparatus of claim 3, wherein said exterior electrode comprises at least one of a plate and a screen.

7. The apparatus of claim 3, wherein said exterior electrode comprises an electrical ground.

8. The apparatus of claim 3, wherein said exterior electrode is disposed 1-50 cm from said common electrode.

9. The apparatus of claim 3, further comprising:

a power source electrically connected across said common electrode and said exterior electrode to generate said electric field.

10. The apparatus of claim 9, wherein said power source is configured to generate said electric field with a strength of 2,000-400,000 V/m.

11. The apparatus of claim 1, wherein said at least one extrusion element comprises plural extrusion elements forming plural openings through said enclosure.

12. The apparatus of claim 11, wherein said plural extrusion elements define 2-100 openings in the wall of the enclosure.

13. The apparatus of claim 11, wherein at least one of said plural extrusion elements comprises a metallic member.

14. The apparatus of claim 11, wherein at least one of said plural extrusion elements comprises an insulating member.

15. The apparatus of claim 11, wherein the common electrode has a flat surface facing said plural extrusion elements.

16. The apparatus of claim 11, wherein the common electrode comprises:

protrusions extending toward said plural extrusion elements.

17. The apparatus of claim 1, wherein the common electrode comprises:

a flat surface having a peripheral rim facing said extrusion elements.

18. The apparatus of claim 1, wherein the common electrode is centered in said enclosure.

19. The apparatus of claim 1, wherein said enclosure having a wall which comprises an electrically permeable material.

20. The apparatus of claim 19, wherein said electrically permeable material comprises an insulator.

21. The apparatus of claim 19, wherein said electrically permeable material comprises a frit.

22. The apparatus of claim 19, wherein said electrically permeable material comprises silicon.

23. The apparatus of claim 1, further comprising:

a chamber enclosing at least said enclosure.

24. The apparatus of claim 1, further comprising:

a shroud enclosing at least said enclosure and an inlet for introduction of electronegative gases into the shroud around the at least one extrusion element.

25. An apparatus for producing fibers, comprising:

an enclosure configured to hold a substance from which the fibers are to be extruded, said substance to be in contact with the enclosure;

a common electrode disposed inside the enclosure; and

means for electrospinning said substance from said enclosure with at least one extrusion element including at least one frit segment entirely covering an opening in the extrusion element, said means for electrospinning facing the common electrode.

26. The apparatus of claim 25, wherein said means for electrospinning electrospins fibers from said substance.

27. The apparatus of claim 25, wherein said means for electrospinning electrospins nanofibers from said substance.

28. The apparatus of claim 25, further comprising:

means for collecting said fibers from said means for electrospinning.

29. The apparatus of claim 25, wherein said means for electrospinning electrospins fibers from said substance in an electric field having a strength of 2,000-400,000 V/m.

30. An apparatus for producing fibers, comprising:

an enclosure having an inlet configured to receive a substance from which the fibers are to be composed, said substance to be in contact with the enclosure;

at least one extrusion element including at least one frit segment entirely covering an opening in the extrusion element;

a common electrode disposed inside said enclosure; and

a substance-receiving space between the extrusion element and the common electrode and in communication with said inlet to receive said substance in said space,

wherein the common electrode extends in a first direction and a second direction to form a circular perimeter.

31. The apparatus of claim 30, wherein the circular perimeter of the common electrode has a surface that is non-planar.