Formation of honeycomb polysulfone film with controlled wettability by surfactant-assisted electric breath figure

A surfactant-assisted electric breath figure method, SAEBF, was applied to form the polysulfone, PSF, film. Experimentally, the sodium dodecyl-benzenesulfonate, SDDBS, was employed and the voltage was varied. FESEM images showed that the SAEBF formed PSF films have the honeycomb structure and the pore diameter was reduced with the applied voltage increase. Water contact angle on the honeycomb PSF film surfaces was found to increase with the applied voltage increase and there has a critical voltage at about 0.6 kV among those applied voltages because the applied voltage at lower or higher caused the film surface in hydrophilic or hydrophobic, respectively. A related mechanism was discussed.