Lecture 13: Contact Angle, Young’s Equation and Wetting

This is the second lecture of Chapter 5 on the topic of contact angle and wetting. We begin by defining the contact angle and its description first introduced by Young followed by a discussion of how real surfaces vary from that of ideal surfaces for which Young’s equation applies. The focus will be on rough surfaces as modeled by homogeneous (Wenzel) and heterogeneous (Cassie-Baxter) wetting behavior on such surfaces and the application of engineered roughness to produce superhydrophobicity and its applications.