Surface Modification of PES/PI Blend Membranes Using Different Diamines to Increase the Rejection of Heavy Metals and Dyes

To increase the efficiency of polymeric membranes, the surface of PES/PI polymeric blend membranes was modified by different diamines. Different diamines such as ethylenediamine (representative of aliphatic diamines, EDA), piperazine (representative of cycle diamines, PIP), and 1,4-phenylenediamine (representative of an aromatic diamine, PPD) were exploited to change the surface properties of the membranes. The results showed a favorable rejection for EDA-modified membranes against copper ions from 35 to near 70% (nearly 100% further rejection). This parameter against lead ions was obtained from 29 to about 55%. Furthermore, the prepared membranes illustrated significant development for the removal of organic dyes. The contact angle data implied that the surface of modified membranes was changed. The physicochemical properties of the membranes were investigated with SEM, EDX, AFM, ATR-IR as well as water contact angle.