Electrospinning in a controlled gaseous environment

• US 8,632,721 B2
• Filed: 09/23/2011
• Issued: 01/21/2014
• Est. Priority Date: 04/08/2004
• Status: Expired due to Fees

• Current Assignee: Research Triangle Institute
• Original Assignee: Research Triangle Institute
• Inventors: Andrady, Anthony L., Ensor, David S., Newsome, Randall J.
• Primary Examiner(s): Tentoni, Leo B
• Application Number:
  US13/243,400
• Publication Number:
  US 20120077014A1
• Time in Patent Office: 851 Days
• Field of Search: 264/10, 264/85, 264/464, 264/465, 264/466, 264/484
• US Class Current: 264/465
• CPC Class Codes: D01D 5/0061 characterised by the electro-spinning apparatus
• CPC Class Codes: D01F 11/00 Chemical after-treatment of artificial filaments or the like during manufacture
• CPC Class Codes: H05B 6/62 Apparatus for specific applications
• CPC Class Codes: Y10T 428/249924 Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber

Abstract

Apparatus and method for producing fibrous materials in which the apparatus includes an extrusion element configured to electrospin a substance from which the fibers are to be composed by an electric field extraction of the substance from a tip of the extrusion element, a collector disposed from the extrusion element and configured to collect the fibers, a chamber enclosing the collector and the extrusion element, and a control mechanism configured to control a gaseous environment in which the fibers are to be electrospun. The apparatus and method provide a way to produce a fiber collection having a plurality of nanofibers disposed in relation to each other. The nanofibers in the fiber collection are preferentially oriented along a longitudinal axis of the fiber collection.

Claims

1. A method for producing a fiber collection comprising:

providing a substance from which the fibers are to be composed to a tip of an electrospinning element;

applying an electric field to the electrospinning element in an electrospinning direction of the electrospining element;

controlling a gaseous environment about where the fibers are to be electrospun to retard a drying rate of the fibers; and

depositing a plurality of nanofibers disposed in relation to each other to form the fiber collection,

said nanofibers in said fiber collection being preferentially oriented with a principal axis of a majority of the fibers lying on average along a longitudinal axis of the fiber collection extending parallel to a surface of the fiber collection.

2. The method of claim 1, wherein said nanofibers in the formed fiber collection are oriented with a principal axis of a majority of the nanofibers lying within 30°

of the longitudinal axis.

3. The method of claim 1, wherein said nanofibers in the formed fiber collection are oriented with a principal axis of a majority of the nanofibers lying within 10°

of the longitudinal axis.

4. The method of claim 1, further comprising depositing the fiber collection on a mesh supporting the nanofibers.

5. The method of claim 1, wherein the nanofibers in the formed fiber collection comprise at least one of acrylonitrile/butadiene copolymer, cellulose, cellulose acetate, chitosan, collagen, DNA, fibrinogen, fibronectin, nylon, poly(acrylic acid), poly(chloro styrene), poly(dimethyl siloxane), poly(ether imide), poly(ether sulfone), poly(ethyl acrylate), poly(ethyl vinyl acetate), poly(ethyl-co-vinyl acetate), poly(ethylene oxide), poly(ethylene terephthalate), poly(lactic acid-co-glycolic acid), poly(methacrylic acid) salt, poly(methyl methacrylate), poly(methyl styrene), poly(styrene sulfonic acid) salt, poly(styrene sulfonyl fluoride), poly(styrene-co-acrylonitrile), poly(styrene-co-butadiene), poly(styrene-co-divinyl benzene), poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidene fluoride), polyacrylamide, polyacrylonitrile, polyamide, polyaniline, polybenzimidazole, polycaprolactone, polycarbonate, poly(dimethylsiloxane-co-polyethyleneoxide), poly(etheretherketone), polyethylene, polyethyleneimine, polyimide, polyisoprene, polylactide, polypropylene, polystyrene, polysulfone, polyurethane, poly(vinylpyrrolidone), proteins, SEBS copolymer, silk, and styrene/isoprene copolymer.

6. The method of claim 1, wherein the nanofibers in the formed fiber collection comprise a polymer blend.

7. The method of claim 6, wherein the polymer blend of the nanofibers in the formed fiber collection comprises at least one of poly(vinylidene fluoride)-blend-poly(methyl methacrylate), polystyrene-blend-poly(vinylmethylether), poly(methyl methacrylate)-blend-poly(ethyleneoxide), poly(hydroxypropyl methacrylate)-blend poly(vinylpyrrolidone), poly(hydroxybutyrate)-blend-poly(ethylene oxide), protein blend-polyethyleneoxide, polylactide-blend-polyvinylpyrrolidone, polystyrene-blend-polyester, polyester-blend-poly(hyroxyethyl methacrylate), poly(ethylene oxide)-blend poly(methyl methacrylate), poly(hydroxystyrene)-blend-poly(ethylene oxide)).

8. The method of claim 1, wherein the controlling a gaseous environment comprises:

retarding a drying rate of the fibers by introducing an organic solvent into the gaseous environment.

9. The method of claim 1, wherein the depositing a plurality of nanofibers comprises:

electrospinning the substance from the tip of the electrospinning element by an electric field extraction of the substance from the tip into the gaseous environment.

10. The method of claim 1, wherein the controlling a gaseous environment comprises:

flowing an electronegative gas through into the gaseous environment.

11. The method of claim 1, wherein the controlling a gaseous environment comprises:

flowing at least one of CO₂, CO, SF₆, CF₄, N₂O, CCl₄, CCl₃F, and C₂Cl₂F₂ into the controlled gaseous environment.

12. The method of claim 1, further comprising:

introducing a vapor of a solvent into the gaseous environment.

13. The method of claim 12, wherein the introducing a vapor comprises:

introducing the vapor at a predetermined vapor pressure.

14. The method of claim 12, where the introducing comprises:

introducing at least one of dimethyl formamide, methylene chloride, acetone, and water.