The permeability as a function of the feed concentration for the chitosan membrane had a different trend from that of the N-methylol nylon 6 membrane. The permeability of the chitosan membrane decreased with increasing ethanol concentration, while
a maximum existed in the permeability curves of the N-methylol nylon 6 membrane. For the blend membranes, the permeability as the function of feed concentration also showed a maximum value. The presence of hydrophobic component, i.e. Nmethylol
nylon 6, accounted for this behavior, which introduced a strong plasticizing effect on the blend membrane when confronting the ethanol±water mixtures.
The blend ratio of the membrane has the opposite influence on pervaporation performance at the feed solutions of high and low water contents (90 and
5 wt%). At a feed solution of high water content, the permeability increased with an increase in chitosan content and showed a maximum separation factor at
the chitosan content around 60 wt%. At the feed solution of low water content, the permeability decreased, while the separation factor increased, with
an increase in chitosan content.