Figure 23: FESEM photographs of the surfaces of the MWNTs/PSf blend membranes with different contents of MWNTs: (a) just PSf membrane; (b) 0.5 wt.% ofMWNTs; (c) 1.0 wt.% of MWNTs; (d) 1.5 wt.% of MWNTs; (e) 2.0 wt.% of MWNTs; (f) 4.0 wt.% of MWNTs.