The influence of the interior structure of Aliquat 336/PVC membranes to their extraction behavior

In this study, new results of the cross-sectional structures of Aliquat 336/PVC-based composite membranes were obtained using Scanning Electron Microscopy (SEM). The SEM images show that micro channels exist when the Aliquat 336 content reaches a certain level. Our data suggests that this level is between 30-40% (m/m) Aliquat 336/PVC. The extraction of Cd(II) using these membranes clearly shows that the micro channels in the membrane facilitated the transportation of the free Aliquat 336 molecules and the Aliquat 336-CdCl3 ion pairs within the membrane and as such enhances the extraction rate. Results of this study provide valuable information for future work in modeling of the extraction mechanism.