A method for preparing carbon nanofluid

Abstract

The present invention provides a method for preparing a carbon nanofluid. The method includes providing a base fluid, providing a number of carbon nanotubes, combining the carbon nanotubes with the base fluid, dispersing the carbon nanotubes substantially evenly in the base fluid through a physical agitation operation, and cooling a system performing the physical agitation operation during the physical agitation operation. The present invention also provides a carbon nanofluid capable of serving as a heat transfer fluid. The carbon nanofluid includes about 99.8 to about 98% by volume of a base fluid, and from about 0.2 to about 2.0% by volume of functionalized carbon nanotubes substantially evenly-dispersed in the base fluid.

1 . A method for preparing carbon nanofluid, the method comprising: 
 providing a base fluid;    providing a number of carbon nanotubes;    combining the carbon nanotubes with the base fluid; and    dispersing carbon nanotubes substantially evenly in the base fluid through a physical agitation operation; and    cooling a system performing the physical agitation operation during the physical agitation operation.    
     
     
         2 . The method according to  claim 1 , wherein the physical agitation comprises ultrasonication.  
     
     
         3 . The method according to  claim 1 , wherein the carbon nanotubes comprise at least one of single-walled, double-walled and multi-walled carbon nanotubes having a plurality of functional groups introduced thereon.  
     
     
         4 . The method according to  claim 3 , wherein each of the functional groups comprises COOH.  
     
     
         5 . The method according to  claim 1 , wherein the base fluid comprises at least one of ethylene glycol, water and oil.  
     
     
         6 . A method for preparing a fluid capable of serving as a heat transfer agent, the method comprising: 
 introducing a number of functional groups onto carbon nanotubes for providing functionalized carbon nanotubes;    providing a base fluid;    combining the functionalized carbon nanotubes with the base fluid; and    dispersing the carbon nanotubes substantially evenly in the base fluid through an ultrasonication operation; and    cooling a system performing the ultrasonication operation during the ultrasonication operation.    
     
     
         7 . The method according to  claim 6 , wherein introducing the functional groups comprises treating with an acidic solution comprising H 2 SO 4  and HNO 3  in a ratio of about 3:1  
     
     
         8 . The method according to  claim 7 , further comprising purifying the functionalized carbon nanotubes by high speed centrifugation before combining the carbon nanotubes with the base fluid.  
     
     
         9 . The method according to  claim 8 , wherein the carbon nanotubes comprise at least one of single-walled, double-walled and multi-walled carbon nanotubes.  
     
     
         10 . The method according to  claim 8 , wherein each of the functional groups comprises COOH.  
     
     
         11 . The method according to  claim 8 , wherein the base fluid comprises at least one of ethylene glycol, oil and water.  
     
     
         12 . A carbon nanofluid capable of serving as a heat transfer fluid, the carbon nanofluid comprising: 
 (a) about 99.8 to about 98% by volume of a base fluid; and    (b) from about 0.2 to about 2.0% by volume of functionalized carbon nanotubes substantially evenly-dispersed in the base fluid, wherein the carbon nanofluid has a thermal conductivity at least 1.3 times higher than a base fluid having no carbon nanotubes.    
     
     
         13 . The carbon nanofluid according to  claim 12 , wherein the functionalized carbon nanotubes comprise at least one of single-walled, double-walled and multi-walled carbon nanotubes with a number of functional groups introduced thereon.  
     
     
         14 . The carbon nanofluid according to  claim 12 , wherein the base fluid comprises at least one of ethylene glycol, water and oil.  
     
     
         15 . A carbon nanofluid made by the process of: 
 introducing a number of functional groups onto carbon nanotubes for providing functionalized carbon nanotubes;    providing a base fluid;    combining the functionalized carbon nanotubes with the base fluid; and    dispersing the carbon nanotubes substantially evenly in the base fluid through an ultrasonication operation; and    cooling a system performing the ultrasonication operation during the ultrasonication operation.