High mass throughput particle generation using multiple nozzle spraying

• US 7,498,063 B2
• Filed: 07/12/2004
• Issued: 03/03/2009
• Est. Priority Date: 05/16/2000
• Status: Expired due to Fees

• Current Assignee: Regents of The University of Minnesota (University of Minnesota)
• Original Assignee: Regents of The University of Minnesota (University of Minnesota)
• Inventors: Chen, Da-Ren, Pui, David Y. H.
• Primary Examiner(s): PARKER, FREDERICK JOHN
• Application Number:
  US10/889,341
• Publication Number:
  US 20040241315A1
• Time in Patent Office: 1,695 Days
• Field of Search: None
• US Class Current: 427/479
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: B05B 1/14 with multiple outlet openings B05B1/02, B05B1/26 take precedence; with strainers in or outside the outlet opening
• CPC Class Codes: B05B 13/06 specially designed for treating the inside of hollow bodies spray heads B05B1/00 - B05B7/00; devices for covering leaks in pipes or hoses, e.g. hose-menders, from inside the pipe F16L55/162; sprayed layers of rubber or plastics for internal protection of pipes or pipe fittings against corrosion or incrustation F16L58/1027
• CPC Class Codes: B05B 5/025 Discharge apparatus, e.g. electrostatic spray guns
• CPC Class Codes: B05B 5/0255 spraying and depositing by electrostatic forces only
• CPC Class Codes: B05B 5/032 for spraying particulate materials
• CPC Class Codes: B05B 5/08 Plant for applying liquids or other fluent materials to objects
• CPC Class Codes: B05B 5/087 Arrangements of electrodes, e.g. of charging, shielding, collecting electrodes B05B5/12, B05B5/14 take precedence; arrangements of electrodes on the discharge apparatus B05B5/0533
• CPC Class Codes: B05B 7/0408 with arrangements for mixing two or more liquids
• CPC Class Codes: B05B 7/066 with an inner liquid outlet surrounded by at least one annular gas outlet

Abstract

Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.

Claims

1. An electrospraying method, the method comprising:

providing a plurality of nozzle structures, wherein each nozzle structure comprises at least one opening defined along a center axis of the nozzle structure and terminating at a dispensing end thereof from which a spray of particles having an electrical charge applied thereto is dispensed, wherein the particles have a nominal diameter of about 1 nanometer to about 2000 nanometers, wherein the dispensing end of each nozzle structure is separated from the dispensing end of adjacent nozzle structures, and further wherein the dispensing end of a first nozzle structure terminates in a first plane orthogonal to the center axis of the nozzle structure and dispensing ends of one or more other nozzle structures terminate in one or more different planes than the first plane;

dispensing the spray of particles from each nozzle structure by creating a nonuniform electrical field between the dispensing ends from which the sprays are established and an electrode electrically isolated from the dispensing ends; and

depositing the particles on a surface to form a coating thereon.

2. The method of claim 1, wherein the surface upon which a coaling is formed is part of a target structure positioned proximate the electrode electrically isolated from the dispensing ends, and further wherein the surface upon which the coating is formed lies between at least a portion of the electrode and the dispensing ends.

3. The method of claim 2, wherein the target structure comprises a tube.

4. The method of claim 1, wherein each of the nozzle structures comprises a capillary tube comprised of a body portion and a tapered capillary tip at the dispensing end of the capillary tube.

5. The method of claim 1, wherein each of the nozzle structures comprises a tapered portion used to define the opening, and further wherein at least a part of each of the nozzle structures extend from an integral multiple nozzle structure conductive portion.

6. The method of claim 1, wherein dispensing the spray of particles includes dispensing a spray of microdroplets comprising an active ingredient, and further wherein the electrical charge is concentrated on the active ingredient as the microdroplet evaporates.

7. The method of claim 1, wherein dispensing the spray of particles includes dispensing a spray of microdroplets comprising a particle, and further wherein the electrical charge is concentrated on the particle as the microdroplet evaporates, wherein the electrical charge of the microdroplet concentrated on the particle is in the range of about 80 percent to 95 percent of the Rayleigh charge limit for the microdroplet.

8. The method of claim 1, wherein the particles have a nominal diameter of about 1 nanometers to about 200 nanometers.

9. The method of claim 1, wherein each of the nozzle structures comprise at least a first and second opening terminating at the dispensing end of each nozzle structure.

10. The method of claim 9, wherein the method further comprises:

providing a first flow of a first fluid composition at the first opening;

providing a second flow of a second fluid composition at the second opening; and

establishing a spray of particles from the first and second fluid compositions.

11. The method of claim 1, wherein the method further comprises:

providing a charged pattern; and

collecting the spray of particles on the charged pattern.

12. The method of claim 1, wherein depositing the particles on a surface to form a coating thereon comprises depositing a plurality of layers on the surface.

13. The method of claim 1, wherein providing a plurality of nozzle structures comprises providing a circular configuration of nozzle structures comprising an outer multiple nozzle structure ring and one or more inner multiple nozzle structure rings, wherein each of the outer multiple nozzle structure rings and the inner multiple nozzle structure rings arc concentric about a center nozzle structure, and further wherein each of the nozzle structures of the one or more inner multiple nozzle structure rings are at a substantially equal internozzle distance (L) from adjacent nozzle structure.

14. The method of claim 1, wherein the dispensing ends of the plurality of nozzle structures form a configuration with the dispensing end of the first nozzle structure lying in the first plane orthogonal to the center axis thereof and at least one or more other dispensing ends of the plurality nozzle structures lying in at least a second plane different from the first plane and orthogonal to the center axis of the first nozzle structure.

15. The method of claim 1, wherein the center axes of two or more nozzle structures are not parallel to one another.

16. An electrospraying method, the method comprising:

providing a plurality of nozzle structures, wherein each nozzle structure comprises at least two openings defined along a center axis of the nozzle structure and terminating at a dispensing end thereof from which a spray of particles having an electrical charge applied thereto is dispensed, wherein the at least two openings comprise at least a first and second opening terminating at the dispensing end of each nozzle structure, wherein the dispensing end of a first nozzle structure terminates in a first plane orthogonal to the center axis of the nozzle structure, and further wherein the dispensing ends of one or more other nozzle structures terminate in one or more different planes than the first plane;

providing a first flow of a first fluid composition at the first opening;

providing a second flow of a second fluid composition at the second opening;

dispensing the spray of particles from each nozzle structure using the first and second fluid compositions by creating a nonuniform electrical field between the dispensing ends from which the sprays are established and an electrode electrically isolated from the dispensing ends, wherein the particles have a nominal diameter of about 1 nanometer to about 2000 nanometers, and further wherein dispensing the spray of particles comprises dispensing a spray of microdroplets comprising an active ingredient, wherein the electrical charge is concentrated on the active ingredient as the microdroplet evaporates;

providing a target structure comprising a surface upon which a coating is to be formed, wherein the target structure is positioned proximate the electrode electrically isolated from the dispensing ends, and further wherein the surface upon which the coating is to be formed lies between at least a portion of the electrode and the dispensing ends; and

depositing the particles on the surface of the target structure to form a coating thereon.

17. The method of claim 16, wherein the target structure comprises a tube.

18. The method of claim 16, wherein each of the nozzle structures comprises a capillary tube comprised of a body portion and a tapered capillary tip at the dispensing end of the capillary tuba.

19. The method of claim 16, wherein each of the nozzle structures comprises a tapered portion used to define the opening, and further wherein at least a part of each of the nozzle structures extend from an integral multiple nozzle structure conductive portion.

20. The method of claim 16, wherein the electrical charge of the microdroplet concentrated on the particle is in the range of about 80 percent to 95 percent of the Rayleigh charge limit for the microdroplet.

21. The method of claim 16, wherein the particles have a nominal diameter of about 1 nanometers to about 200 nanometers.

22. The method of claim 16, wherein the method further comprises:

providing a charged pattern; and

collecting the spray of particles on the charged pattern.

23. The method of claim 16, wherein depositing the particles on a surface to form a coating thereon comprises depositing a plurality of layers on the surface.

24. The method of claim 16, wherein providing a plurality of nozzle structures comprises providing a circular configuration of nozzle structures comprising an outer multiple nozzle structure ring and one or more inner multiple nozzle structure rings, wherein each of the outer multiple nozzle structure rings and the inner multiple nozzle structure rings are concentric about a center nozzle structure, and further wherein each of the nozzle structures of the one or more inner multiple nozzle structure rings are at a substantially equal internozzle distance (L) from adjacent nozzle structures.

25. The method of claim 16, wherein the dispensing ends of the plurality of nozzle structures form a configuration with the dispensing end of the first nozzle structure lying in the first plane orthogonal to the center axis thereof and at least one or more other dispensing ends of the plurality nozzle structures lying in at least a second plane different from the first plane and orthogonal to the center axis of the first nozzle structure.

26. The method of claim 16, wherein the center axes of two or more nozzle structures are not parallel to one another.

27. An electrospraying method, the method comprising:

providing a plurality of nozzle structures, wherein each of the plurality of nozzle structures comprises at least two openings defined along a center axis of the nozzle structure and terminating at a dispensing end thereof from which a spray of particles having an electrical charge applied thereto is dispensed, wherein the at least two openings comprise at least a first and second opening terminating at the dispensing end of the at least one nozzle structure, wherein the dispensing end of a first nozzle structure terminates in a first plane orthogonal to the center axis of the nozzle structure, and further wherein dispensing ends of one or more other nozzle structures terminate in one or more different planes than the first plane;

providing a first flow of a first fluid composition at the first opening;

providing a second flow of a second fluid composition at the second opening;

dispensing the spray of particles from the plurality of nozzle structures using the first and second fluid compositions by creating a nonuniform electrical field between the dispensing ends from which the spray is established and an electrode electrically isolated from the dispensing ends, wherein the particles have a nominal diameter of about 1 nanometer to about 2000 nanometers;

providing a target structure comprising a surface upon which a coating is to be formed; and

depositing the particles on the surface of the target structure to form a coating thereon.

28. The method of claim 27, wherein the target structure is positioned proximate the electrode electrically isolated from the dispensing ends, and further wherein the surface upon which the coating is to be formed lies between at least a portion of the electrode and the dispensing ends.

29. The method of claim 27, wherein the target structure comprises a tube.

30. The method of claim 27, wherein each of the nozzle structures comprises a capillary tube comprised of a body portion and a tapered capillary tip at the dispensing end of the capillary tube.

31. The method of claim 27, wherein each of the nozzle structures comprises a tapered portion used to define the opening, and further wherein at least a part of each of the nozzle structures extend from an integral multiple nozzle structure conductive portion.

32. The method of claim 27, wherein dispensing the spray of particles comprises dispensing a spray of microdroplets comprising an active ingredient, wherein the electrical charge is concentrated on the active ingredient as the microdroplet evaporates.

33. The method of claim 32, wherein the electrical charge of the microdroplet concentrated on the particle is in the range of about 80 percent to 95 percent of the Rayleigh charge limit for the microdroplet.

34. The method of claim 27, wherein the particles have a nominal diameter of about 1 nanometers to about 200 nanometers.

35. The method of claim 27, wherein the method further comprises:

providing a charged pattern; and

collecting the spray of particles on the charged pattern.

36. The method of claim 27, wherein depositing the particles on the surface to form a coating thereon comprises depositing a plurality of layers on the surface.

37. The method of claim 27, wherein providing a plurality of nozzle structures comprises providing a circular configuration of nozzle structures comprising an outer multiple nozzle structure ring and one or more inner multiple nozzle structure rings, wherein each of the outer multiple nozzle structure rings and the inner multiple nozzle structure rings are concentric about a center nozzle structure, and further wherein each of the nozzle structures of the one or more inner multiple nozzle structure rings are at a substantially equal internozzle distance (L) from adjacent nozzle structures.

38. The method of claim 27, wherein the dispensing ends of the plurality of nozzle structures form a configuration with the dispensing end of the first nozzle structure lying in the first plane orthogonal to the center axis thereof and at least one or more other dispensing ends of the plurality nozzle structures lying in at least a second plane different from the first plane and orthogonal to the center axis of the first nozzle structure.

39. The method of claim 27, wherein the center axes of two or more nozzle structures are not parallel to one another.