2.2. Preparation of organoclay
Organoclays with various concentrations of octadecylamine (i.e.,0.5, 1.0 and 1.5 CEC times of Na-MMT) were prepared by cation exchange.Details of the preparation process are described in our previouswork[18,19]. It isnoted that the organoclays thatwere preparedby using octadecylamine at 0.5,1.0 and 1.5 times the CEC of Na-MMT,are labeled as 0.5OC-18C, 1.0OC-18C and 1.5OC-18C, respectively.