Molecular Design of Conductive Polymers To Modulate Superoleophobic Properties

Abstract

Natural surfaces can be superhydrophobic, but on the other hand, superoleophobic properties are extremely rare. We demonstrate that modification of the 3,4-alkylenedioxy bridge length in pyrrole-derivative monomers can have a dramatic influence on the superoleophobic properties of electrodeposited conductive polymers. Here we report the synthesis and characterization of novel fluorinated 3,4-ethylenedioxypyrrole (EDOP) and 3,4-propylenedioxypyrrole (ProDOP) monomers and their corresponding electrodeposited polymers. The polymer surfaces were characterized by static and dynamic contact angle measurements, scanning electron microscopy, and cyclic voltammetry. Surprisingly, the antiwetting properties do not depend of the fluorocarbon chain length (F-octyl to F-hexyl) but are in fact governed by the nature of the electrochemically deposited core. Indeed, superhydrophobic and superoleophobic surfaces with extremely low hysteresis and sliding angles for water droplets were obtained by electrochemical polymerization of highly fluorinated EDOP, whereas highly fluorinated ProDOP gave only superhydrophobic surfaces with a sticky behavior. The difference in wettability is attributed to surface nanoporosity resulting from the doping process.