Edv ard Bormashenk o. Libros

Motivated by various natural phenomena, this textbook explores the physics of wetting surfaces. It begins with the fundamentals of surface tension, followed by applications such as floating objects, capillary waves, bouncing droplets, and the locomotion of water striders. The text delves into Marangoni flows, surface tension-induced instabilities, and the condensation and evaporation of droplets, alongside concepts like liquid marbles and the lotus effect, which highlights superhydrophobicity and superoleophobicity. Each concept is supported by numerous qualitative and quantitative exercises. Key topics include the definition of surface tension, the contact angle in wetting, the floating of heavy and light objects, capillary interactions, and the elasticity of liquid surfaces covered with colloidal particles. It also addresses capillary waves, droplet oscillation, evaporation phenomena including the Kelvin and coffee-stain effects, and the dynamics of wetting—covering bouncing, spreading, and rolling droplets. Additionally, the book examines superhydrophobic and superoleophobic regimes, the Leidenfrost effect, and the physics and geometry of soap films and bubbles, providing a comprehensive understanding of these intricate processes.

The revealing of the phenomenon of superhydrophobicity (the „lotus-effect“) has stimulated an interest in wetting of real (rough and chemically heterogeneous) surfaces. In spite of the fact that wetting has been exposed to intensive research for more than 200 years, there still is a broad field open for theoretical and experimental research, including recently revealed superhydrophobic, superoleophobic and superhydrophilic surfaces, so-called liquid marbles, wetting transitions, etc. This book integrates all these aspects within a general framework of wetting of real surfaces, where physical and chemical heterogeneity is essential. Wetting of rough/heterogeneous surfaces is discussed through the use of the variational approach developed recently by the author. It allows natural and elegant grounding of main equations describing wetting of solid surfaces, i. e. Young, Wenzel and Cassie-Baxter equations. The problems of superhydrophobicity, wetting transitions and contact angle hysteresis are discussed in much detail, in view of novel models and new experimental data.