Expanded Nanoclays and Method of Producing Such Expanded Nanoclays

Abstract

A method of producing nanoclays comprising the steps of preparing a first intercalant alkali salt of a carboxylic acid, adding the first intercalant to a swelled clay at a temperature of at least 50° C. so that the metal ions on the clay surface forms a complex with the carboxyl group that enlarges the space between the two galleries of clay. The method further comprises the step of adding an organic acid as a second intercalant to the clay modified by the first intercalant to form a clay/organic salt/organic acid complex. The clay/organic salt/organic acid complex may be post processed by precipitating, homogenizing with a solution comprising of water and alcohol, filtering, drying, milling, and sieving to produce the desired nanoclay.

1 . An expanded nanoclay comprising: 
       
         
           
           
               
               
           
         
       
       wherein:
 M is a divalent metal selected from a group consisting Mg 2+ , Ca 2+ ; 
 R is a long chain alkyl introduced through a first intercalation process; 
 R′ is an organic acid introduced through a second intercalation process; said organic acid is selected from a group consisting of polyacrylic acid, polyacrylamide acid, carboxylic pyrrolidonic acid, and polymethacrylic acid; 
 CL is a layered clay selected from a group consisting of montmorillonite, sepiolite, kaolin, vermiculite, and mica; and 
 R′ is hydrogen bonded with free hydroxyl groups of the layered clay. 
 
     
     
         2 . An expanded nanoclay of claim  29 , said nanoclay has an interlayer distance of at least 30° A. 
     
     
         3 . An expanded nanoclay comprising of
 a layered clay;   an organic salt, said organic salt forming a clay/organic salt complex on the surface of said layered clay, said organic salt added through a first intercalation process; and   a soluble polar organic acid, said organic acid interacting with clay/organic salt complex through hydrogen bonding; said soluble polar organic acid added through a second intercalation process.