ゴム技術者のためのソフトマター物理講座

第5章　蒸発・乾燥

抄録

When a drop of coffee dries on a dish, many non-equilibrium processes are taking place. The water changes into vapor and diffuses out in air. Inside the coffee, liquid flow is induced by the surface tension, and coffee particles are convected to the edge of the droplets, leaving ring-like stains at the edge. This example demonstrates the complexity and the multi-physics nature involved in the phenomena we are seeing in our everyday life. Here as the last part of this series of lectures, I will discuss a few physics involved in evaporation and drying focusing on two problems, how the evaporation rate is determined, and how the structure of the dried material is determined.