Fig. 4. (a) Photographs of unmodified (left) and modified (right) polyethersulfone (PES) membranes. (b) Scratches are easily seen on the modified membrane (bottom) compared to the unmodified one (top). The (c) ATFB-TANI molecule and (d) the modified membrane can be protonated and deprotonated when treated with acids and bases. (e) The UV-vis spectra and photo (inset) of undoped (blue) and doped (green) ATFB-TANI dissolved in dimethyl sulfoxide (DMSO). (f) UV light treated TANI stained membranes appeared colorless after rinsing in a vial of ethanol.