Electrospun electroactive polymers

a technology of electroactive polymers and electroactive polymers, which is applied in the direction of filament/thread forming, transportation and packaging, yarn, etc., can solve the problems of labor-intensive and time-consuming current process, large equipment that is complex to maintain, and process that leads to -phase formation labor-intensive and time-consuming, etc., and achieves fast and easy operation and simple setup.

Inactive Publication Date: 2006-03-16
NASA +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0011] The present invention allows for the production of electroactive polymers using a simple set-up and a processing method that is fast and easy to run. Additionally, electroactive fibers can be created that are only nanometers in diameter. In situ induction of polar phase and spontaneous dipolar orientation of electroactive polymers by a single step electrospinning process produces electroactive polymers from a polymer solution. The need for direct contact or corona filed poling is eliminated, resulting in arc-free processing. Further, nanofibers and fibrous nonwoven mats are produced with minimal pre- and post-processing. Enabling materials are provided for a wide expanse of applications in such fields as aerospace, biomedical, military and environmental.

Problems solved by technology

Unfortunately, current methodology for producing electroactive polymers entails melt-pressing of the polymer at high temperatures, followed by stretching and corona-poling at high electric field strengths in order to produce the polar phase and electroactive behavior.
This current process is labor-intensive and time-consuming, and requires large equipment that is complex to maintain.
The process that leads to the β-phase formation is labor intensive and time consuming, requiring initial melt processing and drawing into a film, followed by further stretching of the film at an elevated temperature either uniaxially or biaxially to induce the polar phase.
While electrospinning is an advantageous processing method to apply to polymers, it has not been applied for the purpose of producing electroactive polymers.

Method used

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Examples

Experimental program
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Effect test

example 1

(PVDF / DMF)

[0032] PVDF pellets (MW 530,000, Aldrich Chemical Company, Inc.) were dissolved into solvent DMF at a concentration of 30 weight percent (wt %) PVDF. The solutions were electrospun into fibers using the apparatus illustrated in FIG. 2. The polymer resins were delivered to the system using a plastic syringe (Becton Dickinson) equipped with an 18-gauge blunt needle tip. Metered infusion of the solution into the system was accomplished with a digitally-controlled syringe pump (KD Scientific, model 100). Voltage was applied to this supply system via an alligator clip connected to the needle and to a high voltage power supply unit (Spellman High Voltage Electronics Corporation, model CZE 1000R). The grounded target was a rotating drum, which imparted some degree of fiber orientation to the collected mat. For these experiments, the infusion pump was set to deliver polymer resin at a rate of 6.0 milliliters per hour (mL / hr). Distance between the needle tip and the grounded targe...

example 2

[0045] PVDF solutions in the solvent DMF with and without single wall nanotubes (SWNTs) were electrospun at various concentrations, as outlined in Table 2. PVDF pellets (MW 530,000, Aldrich Chemical Company, Inc.) were dissolved into DMF at a concentration of 30 weight percent (wt %) PVDF. A SWNT stock solution (1% w / w) in DMF was prepared to mix with PVDF / DMF solution to prepare various compositions of SWNT / PVDF / DMF solutions. The solutions were electrospun into fibers using the apparatus illustrated in FIG. 2. The polymer resins were delivered to the system using a plastic syringe (Becton Dickinson) equipped with an 18-gauge blunt needle tip. Metered infusion of the solution into the system was accomplished with a digitally-controlled syringe pump (KD Scientific, model 100). Voltage was applied to this supply system via an alligator clip connected to the needle and to a high voltage power supply unit (Spellman High Voltage Electronics Corporation, model CZE 1000R). The grounded ta...

example 3

[0055] PVDF combined with carbon nanotubes was tested beginning with 0.1% SWNT in 15 wt % PVDF and 1.0% SWNT in 15 wt % PVDF. Small and few fibers formed. When the 1.0% SWNT was electrospun, black drops fell out of the solution as a result of the excessive concentration of SWNTs. A 0.1 % SMNT in 25 wt % PVDF spun well and was able to be spun onto a rotating roller, producing a nonwoven mat which was vacuum-dried at 60° C. A nonwoven mat was also produced from 0.2% SWNT in 25 wt % PVDF. Optimal conditions for the PVDF solutions with carbon nanotubes were slightly different depending on amount of carbon nanotubes and concentration of PVDF.

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Abstract

Electroactive polymers are produced via electrospinning. The induction of electroactivity via electrospinning can be utilized with one or more soluble polymers with polarizable moieties. Suitable polymer classes include but are not limited to polyimides, polyamides, vinyl polymers, polyurethanes, polyureas, polythioureas, polyacrylates, polyesters, and biopolymers. Any one or more solvents sufficient to dissolve the one or more polymers of interest and make a spinnable solution can be utilized. The polymer can be electrospun into fiber and fibrous nonwoven mat. The electroactive polymer can be doped with inclusions, such as nanotubes, nanofibers, and piezoceramic powders for dielectric enhancement The availability of electroactive polymer fibers and fibrous nonwoven mat will enable many new applications for electroactive polymers.

Description

CLAIM OF BENEFIT OF PROVISIONAL APPLICATION [0001] Pursuant to 35 U.S.C. § 119, the benefit of priority from provisional application having U.S. Ser. No. 60 / 530,637, filed on Dec. 19, 2003, is claimed for this nonprovisional application.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OF DEVELOPMENT [0002] The invention described herein was made in part by employees of the United States Government and may be manufactured and used by and for the Government of the United States for governmental purposes without the payment of any royalties thereon or therefore.BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The present invention relates generally to the production of electroactive polymers via electrospinning. It relates in particular to the induction of the polar phase in electroactive polymers, and the spontaneous orientation of dipoles in a single step process. These materials have widespread application in numerous fields, including aerospace, biomedical, cloth...

Claims

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Application Information

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Patent Type & Authority Applications(United States)
IPC IPC(8): D02G3/00
CPCB82Y30/00D01D5/0038D01F1/10D04H3/02Y10T428/2913H01L41/193H01L41/257H01L41/45D04H3/16H10N30/857H10N30/045H10N30/098
Inventor HARRISON, JOYCELYN S.BURNEY, KRISTIN J.OUNAIES, ZOUBEIDAPARK, CHEOLSIOCHI, EMILIE J.
Owner NASA
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