Semi-metallic, strong conductive polymer microfiber, method and fast response rate actuators and heating textiles

Abstract

A method comprising: providing at least one first composition comprising at least one conjugated polymer and at least one solvent, wet spinning the at least one first composition to form at least one first fiber material, hot-drawing the at least one fiber to form at least one second fiber material. In lead embodiments, high-performance poly(3,4-ethylenedioxy-thiophene)/poly(styrenesulfonate) (PEDOT/PSS) conjugated polymer microfibers were fabricated via wet-spinning followed by hot-drawing. In these lead embodiments, due to the combined effects of the vertical hot-drawing process and doping/de-doping the microfibers with ethylene glycol (EG), a record electrical conductivity of 2804 S·cm −1 was achieved. This is believed to be a six-fold improvement over the best previously reported value for PEDOT/PSS fibers (467 S·cm −1 ) and a twofold improvement over the best values for conductive polymer films treated by EG de-doping (1418 S·cm −1 ). Moreover, these lead, highly conductive fibers experience a semiconductor-metal transition at 313 K. They also have superior mechanical properties with a Young's modulus up to 8.3 GPa, a tensile strength reaching 409.8 MPa and a large elongation before failure (21%). The most conductive fiber also demonstrates an extraordinary electrical performance during stretching/unstretching: the conductivity increased by 25% before the fiber rupture point with a maximum strain up to 21%. Simple fabrication of the semi-metallic, strong and stretchable wet-spun PEDOT/PSS microfibers can make them available for conductive smart electronics. A dramatic improvement in electrical conductivity is needed to make conductive polymer fibers viable candidates in applications such as flexible electrodes, conductive textiles, and fast-response sensors and actuators.

1 . A method comprising: providing at least one first composition comprising at least one conjugated polymer and at least one solvent, wet spinning the at least one first composition to form at least one first fiber material, hot-drawing the at least one first fiber material to form at least one second fiber material. 
     
     
         2 . The method of  claim 1 , wherein the method further comprises doping of the first composition. 
     
     
         3 . The method of  claim 1 , wherein the method further comprises de-doping of the first fiber material before hot drawing. 
     
     
         4 . The method of  claim 1 , wherein the method further comprises doping of the first composition and de-doping of the first fiber material before hot drawing. 
     
     
         5 . The method of  claim 2 , wherein the doping is carried out with at least one organic solvent. 
     
     
         6 . The method of  claim 2 , wherein the doping is carried out with ethylene glycol. 
     
     
         7 . The method of  claim 3 , wherein the de-doping is carried out with at least one organic solvent. 
     
     
         8 . The method of  claim 3 , wherein the de-doping is carried out with ethylene glycol. 
     
     
         9 . The method of  claim 1 , wherein the conjugated polymer comprises a polythiophene. 
     
     
         10 . (canceled) 
     
     
         11 . The method of  claim 1 , wherein the conjugated polymer comprises PEDOT. 
     
     
         12 . The method of  claim 1 , wherein the first composition comprises a polymeric dopant for the conjugated polymer. 
     
     
         13 - 14 . (canceled) 
     
     
         15 . The method of  claim 1 , wherein the first composition is an aqueous dispersion. 
     
     
         16 - 19 . (canceled) 
     
     
         20 . The method of  claim 1 , wherein the hot drawing is done at a temperature of 50° C. to 140° C. 
     
     
         21 - 26 . (canceled) 
     
     
         27 . A method comprising: providing at least one first composition comprising PEDOT:PSS and water, wet spinning the at least one first composition to form at least one first fiber material, hot-drawing the at least one first fiber material to form at least one second fiber material, wherein the method further comprises doping of the first composition and de-doping of the first fiber material before hot-drawing. 
     
     
         28 . A fiber material prepared by the method of  claim 1 . 
     
     
         29 . (canceled) 
     
     
         30 . The fiber material of  claim 28 , wherein the fiber material shows a conductivity of at least 2,000 S·cm −1 . 
     
     
         31 . The fiber material of  claim 28 , wherein the fiber material shows a cross-over temperature of semiconductor-to-metal transition of at least 25° C. 
     
     
         32 . The fiber material of  claim 28 , wherein the fiber material shows a cross-over temperature of semiconductor-to-metal transition of at least 40° C. 
     
     
         33 . The fiber material of  claim 28 , wherein the fiber material shows a Young's modulus of at least 5 GPa, a tensile strength of at least 300 MPa, and an elongation at break of at least 10%. 
     
     
         34 . The fiber material of  claim 28 , wherein the fiber material shows a Young's modulus of at least 8 GPa, a tensile strength of at least 409 MPa, and an elongation at break of at least 21%.