Functionalized carbon nanofiber yarn

Abstract

Functionalized nanofiber yarns with increased hydrophilicity with more than doubled water absorption property are provided. Methods of treatment for producing such functionalized nanofiber yarns are also provided.

What is claimed is: 
     
         1 . A nanofiber yarn bundle, comprising:
 at least two treated nanofiber yarns,   wherein the treatment includes exposing the nanofiber yarn bundle to an oxidizing agent and removing the oxidization agent.   
     
     
         2 . The nanofiber yarn bundle of  claim 1 , wherein the treated nanofiber yarn bundle has an increased water absorption rate compared to an untreated nanofiber yarn bundle. 
     
     
         3 . The nanofiber yarn bundle of  claim 2 , wherein the increased water absorption rate is at least 18 mg of water per 1 mg of the treated nanofiber yarn bundle. 
     
     
         4 . The nanofiber yarn bundle of  claim 3 , wherein the oxidizing agent is at least one oxidizing gas or at least one strong acid. 
     
     
         5 . The nanofiber yarn bundle of  claim 4 , wherein the at least one oxidizing gas includes ozone, chlorine, or a combination thereof. 
     
     
         6 . The nanofiber yarn bundle of  claim 4 , wherein the at least one strong acid includes nitric acid, sulfuric acid, perchloric acid, dichromate, permanganate acid, or a combination thereof. 
     
     
         7 . The nanofiber yarn bundle of  claim 1 , wherein the nanotube yarn bundle is a carbon nanotube yarn bundle, and the at least two treated nanofiber yarns have microstructurally modified carbon nanotube walls. 
     
     
         8 . A method of increasing hydrophilicity of a yarn bundle, the method comprising:
 a) preparing a nanofiber yarn bundle;   b) selecting an oxidizing agent;   c) exposing the nanofiber yarn bundle to the oxidizing agent; and   d) removing the nanofiber yarn bundle from the exposure of the oxidizing agent and freeing the nanofiber yarn bundle of the oxidizing agent.   
     
     
         9 . The method of  claim 8 , wherein the oxidizing agent comprises at least one acid. 
     
     
         10 . The method of  claim 8 , wherein the oxidizing agent comprises a combination of at least two acids. 
     
     
         11 . The method of  claim 10 , wherein the two acids are mixed in two to one ratio. 
     
     
         12 . The method of  claim 10 , wherein the two acids include at least one of a nitric acid, a sulfuric acid, and a perchloric acid. 
     
     
         13 . The method of  claim 10 , wherein the combination includes a nitric acid and a sulfuric acid mixture, a sulfuric acid and a potassium dichromate mixture, or a sulfuric acid and a potassium permanganate mixture. 
     
     
         14 . The method of  claim 10 , wherein the oxidizing agent includes 70% nitric acid mixed with a 98% sulfuric acid in two-to-one volumetric ratio, respectively. 
     
     
         15 . The method of  claim 8 , wherein the oxidizing agent comprises at least one gas. 
     
     
         16 . The method of  claim 15 , wherein the gas is ozone or chlorine. 
     
     
         17 . The method of  claim 8 , wherein the nanofiber yarn bundle is exposed to the oxidizing agent for at least 300 minutes. 
     
     
         18 . The method of  claim 8 , wherein the nanofiber yarn bundle is exposed to the oxidizing agent for at least 30 minutes. 
     
     
         19 . The method of  claim 8 , wherein the nanofiber yarn bundle is exposed to the oxidizing agent for at least 10 minutes.