Validation of surface wettability theories via electrochemical analysis

We have developed an experimental method to quantify the parameters defining the shape of a droplet placed on a rough surface. The parameters include the solid-liquid interfacial area under a sessile drop (measured via cyclic voltammetry) along with the optically measurable properties such as the contact angle and projected geometrical area. Using these parameters, it is possible to quantitatively validate many theoretical models proposed for predicting the wetting behaviour on rough surfaces. Carbon substrates with nanostructured surface features were prepared using plasma treatment to test the predictions from the Cassie-Baxter and Wenzel models. These predictions are compared with our experimental results.