Branched versus linear perfluorocarbon chains in the formation of superhydrophobic electrodeposited films with low bioaccumulative potential

This work concerns the replacing of long and linear perfluorocarbon chains by branched ones to reduce the bioaccumulative potentials of fluorinated materials. Here, novel 3,4-propylenedioxythiophene monomers containing a branched perfluorocarbon chain or a linear perfluorocarbon chain with the same number of C-F bonds are synthesized and used to produce superhydrophobic films by electropolymerization. The branching induces higher steric hindrance during electropolymerization, which reduces the mean polymer backbone length, decreases the polymer electrical conductivity, and changes the surface morphology. Here, we show that these changes can be beneficial in the case of super liquid-repellent properties. Indeed, superhydrophobic properties are obtained with linear and branched perfluorocarbon chains. However, while superoleophilic properties are obtained with both linear perfluorocarbon chains, much higher oleophobic properties are obtained with branched perfluorocarbon chains. Here, the differences are due to changes in the surface morphology and roughness. This work opens new strategies to obtain surfaces with high hydrophobicity and oleophobicity.