Wettability control of conjugated polymer films by electric-field polarization technique

Abstract

Polymer film materials with smart wetting surfaces can be widely used in aerospace, petrochemicals, shipbuilding, automotives, energy saving, environmental protection and other fields. Here, the wettability of conjugated polymer poly(3-hexylthiophene) (P₃HT) films was accurately controlled by an electric field polarization technique, and transition of the films from being hydrophobic to hydrophilic was successfully achieved. The water contact angle of the P₃HT films could be changed from 105.9° to 75.6° by the effect of the electric field. More importantly, the contact angle of the P₃HT films’ surfaces could be precisely controlled by adjusting the electric field strength. The molecular orientation of the conjugated polymers under electric field is investigated to explain this novel phenomenon, which will expand the application scope and improve the properties of conjugated polymers greatly.