Electro spinning of submicron diameter polymer filaments

• US 6,641,773 B2
• Filed: 01/10/2001
• Issued: 11/04/2003
• Est. Priority Date: 01/10/2001
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Hirvonen, James, Kleinmeyer, James, Deitzel, Joseph
• Primary Examiner(s): Tentoni, Leo B.
• Application Number:
  US09/757,272
• Publication Number:
  US 20020089094A1
• Time in Patent Office: 1,028 Days
• Field of Search: 264/210.8, 264/211.12, 264/452, 264/465
• US Class Current: 264/452
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: D01D 5/0092 characterised by the electrical field, e.g. combined with a magnetic fields, using biased or alternating fields
• CPC Class Codes: Y10S 977/788 Of specified organic or carbon-based composition
• CPC Class Codes: Y10S 977/84 Manufacture, treatment, or detection of nanostructure
• CPC Class Codes: Y10S 977/933 Spintronics or quantum computing

Abstract

An electro spinning process yields uniform, nanometer diameter polymer filaments. A thread-forming polymer is extruded through an anodically biased die orifice and drawn through an anodically biased electrostatic field. A continuous polymer filament is collected on a grounded collector. The polymer filament is linearly oriented and highly uniform in quality. The filament is particularly useful for weaving body armor, for chemical/biological protective clothing, as a biomedical tissue growth support, for fabricating micro sieves and for microelectronics fabrication.

Claims

1. An electro spinning process for extruding a thread-forming polymer and drawing between an electrically charged die, having a first electrical bias and a first polarity and an electrically charged collecting means to produce a continuous polymer filament, comprising the steps of:

liquefying the thread-forming polymer and extruding through a die orifice to form a liquid-state filament,

drawing the liquid-state filament through a longitudinally sequentially biased electrostatic field having the same polarity as the first polarity, thereby imparting a bias gradient to the liquid-state filament,

solidifying the liquid-state filament to form a linearly oriented solid polymer filament, and

collecting the solid polymer filament on the collecting means.

2. The electro spinning process of claim 1 wherein the die and electrostatic field are positively biased and the collecting means is negatively biased.

3. The electro spinning process of claim 1 wherein the die and charged electrostatic field are positively biased and the collecting means is grounded.

4. The electro spinning process of claim 1 wherein the longitudinally sequentially biased field gradient has a length of 3 centimeters or more.

5. The electro spinning process of claim 1 wherein the longitudinally sequentially biased field gradient has a length of 3 to 100 centimeters.

6. The electro spinning process of claim 1 wherein the longitudinally sequentially biased field gradient is linearly charged.

7. The electro spinning process of claim 1 wherein the longitudinally sequentially biased field gradient is linearly charged to 10,000 to 300,000 volts/meter.

8. The electro spinning process of claim 1 wherein the longitudinally sequentially biased field gradient is linearly charged to 50,000 to 250,000 volts/meter.

9. The method of claim 1 wherein the polymer filament is extruded to a diameter of 100 to 500 nanometers.