Continuous method for obtaining composite fibres containing colloidal particles and resulting fibre

Abstract

The invention relates to a method for obtaining composite fibers, that comprises dispersing colloidal particles in a solvent, injecting the dispersion into a co-flow of a polymer coagulation solution for forming a pre-fiber, circulating the pre-fiber in a duct, extracting, optionally washing and drying the pre-fiber in order to obtain a fiber, and winding the fiber thus obtained, characterized in that the minimum retention time of the fiber within the duct is adjusted so that it has a mechanical strength sufficient to be extracted from the duct, and in that its extraction is vertical and continuous. The invention also relates to composite fibers that can be made according to said method.

1 . A continuous process for producing composite fibers, said process comprising:
 dispersing colloidal particles in a solvent optionally with the help of a surface-active agent,   injecting the dispersion of colloidal particles into a coflow of a coagulation solution comprising a polymer as coagulating agent, in order to form a prefiber,   circulating said prefiber in a duct,   extracting said prefiber,   optional washing said prefiber,   drying said prefiber, in order to obtain a fiber, and   winding the fiber thus obtained,   
     characterized in that the minimum residence time of the prefiber in said duct is adjusted so that the prefiber has a sufficient mechanical strength to be extracted from said duct and in that the extraction of said prefiber is a continuous vertical extraction. 
   
   
       2 . The process as claimed in  claim 1 , characterized in that the colloidal particles are chosen from nanotubes, tungsten sulfide, molybdenum sulfide, boron nitride, vanadium oxide, cellulose whiskers, silicon carbide whiskers or clay platelets. 
   
   
       3 . The process as claimed in  claim 2 , characterized in that the nanotubes are carbon nanotubes. 
   
   
       4 . The process as claimed in  claim 3 , characterized in that the carbon nanotubes have a length from 0.1 to 20 μm. 
   
   
       5 . The process as claimed in  claim 3 , characterized in that the carbon nanotubes have a diameter ranging from 0.1 to 100 nm. 
   
   
       6 . The process as claimed in  claim 1 , characterized in that the polymer is a chosen from polyalcohol, alginate or cellulose. 
   
   
       7 . The process as claimed in  claim 6 , characterized in that the polyalcohol is polyvinyl alcohol. 
   
   
       8 . The process as claimed in  claim 1 , characterized in that the rate of flow of the coagulation solution measured at the center of the duct is from 1 m/min to 100 m/min. 
   
   
       9 . The process as claimed in  claim 1 , characterized in that the extraction of said prefiber is a continuous extraction by overflowing of the coagulation solution. 
   
   
       10 . A composite fiber obtained according to the process as claimed in  claim 1 . 
   
   
       11 . The process as claimed in  claim 3 , characterized in that the carbon nanotubes have a diameter ranging from 0.4 to 50 nm. 
   
   
       12 . The process as claimed in  claim 3 , characterized in that the carbon nanotubes have a diameter ranging from 1 to 30 nm. 
   
   
       13 . The process as claimed in  claim 1 , characterized in that the rate of flow of the coagulation solution measured at the center of the duct is from 2 m/min to 50 m/min. 
   
   
       14 . The process as claimed in  claim 1 , characterized in that the rate of flow of the coagulation solution measured at the center of the duct is from 5 m/min to 25 m/min.