Can One Predict a Drop Contact Angle?

The study of wetting phenomena is great interest due to the multifaceted technological applications hydrophobic and hydrophilic surfaces. theoretical approaches proposed by Wenzel later Cassie Baxter describe behavior a droplet water on rough solid are extensively used continuously updated characterize apparent contact angle droplet. However, equilibrium hypothesis implied in these models means that they not always predictive experimental angles strong metastabilities typically occurring heterogeneous A scheme for thus urgently needed both surface measurements design super-hydrophobic -oleophobic surfaces with desired properties, example, hysteresis. In this work, combination Monte Carlo simulation string method employed calculate free energy profile liquid deposited pillared surface. For analyzed surfaces, it shown there only one minimum corresponds superhydrophobic state while wet can present multiple minima. Furthermore, when roughness decreases amount local minima observed increases. presented approach clarifies origin hysteresis providing quantitative tools understanding controlling at structured