Figure 3

FTIR spectra of track-etched PVDF membrane after 30 min of etching in KOH/KMnO\(_{4}\) solution at \(65\,^{\circ }\hbox {C}\) (grey curve) and after subsequent radiation-induced grafting in presence of acrylic acid for 1 h at \(60\,^{\circ }\hbox {C}\) and 48 h of Soxhlet purification (black curve)—zoom in the region of carboxylic acids between 2000 cm\(^{-1}\) and 1500 cm\(^{-1}\)—Inset: FESEM images of PAA-g-PVDF track-etched membrane: (top) view of the surface; (down) cryosection.