Infrared-transparent, polymer fiber-based woven textiles for human body cooling

Abstract

A fiber includes an elongated member and refractive index contrast domains dispersed within the elongated member. The elongated member includes at least one polymer having a transmittance of infrared radiation at a wavelength of 9.5μπι of at least about 40%.

1 . A fiber comprising:
 an elongated member; and   refractive index contrast domains dispersed within the elongated member,   wherein the elongated member includes at least one polymer having a transmittance of infrared radiation at a wavelength of 9.5 μm of at least 40%.   
     
     
         2 . The fiber of  claim 1 , wherein the elongated member includes at least one polyolefin. 
     
     
         3 . The fiber of  claim 1 , wherein the elongated member includes at least one of polyethylene or polypropylene. 
     
     
         4 . The fiber of  claim 1 , wherein:
 the elongated member includes a blend of polyethylene and polypropylene, and a weight percentage of polypropylene relative to a combined weight of polyethylene and polypropylene is in a range of 1% to 50%; or   the elongated member includes a blend of polyethylene and polypropylene, and a weight percentage of polyethylene relative to a combined weight of polyethylene and polypropylene is in a range of 1% to 50%.   
     
     
         5 . The fiber of  claim 1 , wherein the refractive index contrast domains are pores. 
     
     
         6 . The fiber of  claim 5 , wherein the pores have an average pore size in a range of 50 nm to 1000 nm. 
     
     
         7 . The fiber of  claim 5 , wherein a volume percentage of the pores within the elongated member is at least 10%. 
     
     
         8 . The fiber of  claim 1 , wherein the refractive index contrast domains are particulate fillers. 
     
     
         9 . The fiber of  claim 8 , wherein the fillers have an average particle size in a range of 50 nm to 1000 nm. 
     
     
         10 . The fiber of  claim 8 , wherein a volume percentage of the fillers within the elongated member is at least 10%. 
     
     
         11 . The fiber of  claim 8 , wherein the fillers include an inorganic material. 
     
     
         12 . The fiber of  claim 1 , wherein a difference in refractive index between the refractive index contrast domains and the elongated member is at least ±1% with respect to a refractive index of the elongated member. 
     
     
         13 . The fiber of  claim 1 , wherein the elongated member is a first elongated member, and further comprising a second elongated member combined with the first elongated member to form a body of the fiber. 
     
     
         14 . The fiber of  claim 13 , wherein a cross-sectional dimension of at least one of the first elongated member or the second elongated member is up to about 5 μm. 
     
     
         15 . A woven textile including the fiber of  claim 1 . 
     
     
         16 . The woven textile of  claim 15 , having a transmittance of infrared radiation at a wavelength of 9.5 μm of at least 40%. 
     
     
         17 . The woven textile of  claim 15 , having an opacity to visible light over a wavelength range of 400-700 nm of at least 40%. 
     
     
         18 . A cloth comprising:
 at least one layer including a woven textile including the fiber of  claim 1 .   
     
     
         19 . A method of regulating a temperature of a human body, comprising:
 placing a woven textile adjacent to the human body, wherein the woven textile includes the fiber of  claim 1 .   
     
     
         20 . A method of forming a porous polymer fiber, comprising:
 forming a mixture of a solvent and at least one polymer;   extruding the mixture to form a polymer fiber including the solvent dispersed within the polymer fiber; and   extracting the solvent from the polymer fiber to form the porous polymer fiber.   
     
     
         21 . The method of  claim 20 , wherein a volume percentage of the solvent in the mixture is at least 10%. 
     
     
         22 . The method of  claim 20 , wherein the mixture includes at least one polyolefin. 
     
     
         23 . The method of  claim 20 , wherein the mixture includes at least one of polyethylene or polypropylene. 
     
     
         24 . The method of  claim 20 , wherein the mixture includes polyethylene and polypropylene.