Preface

Chapter 8 **A General-Purpose Multiphase/Multispecies Model to Predict**

Chapter 9 **Micro/Nano Hierarchical Super-Lyophobic Surfaces Against**

**Heterobifunctional Acyclic Oligomers (HEHAO)**

Harinarayanan Puliyalil, Gregor Filipič and Uroš Cvelbar

Irep Gözen, Paul Dommersnes and Aldo Jesorka

**Gallium-Based Liquid Metal Alloy 265** Daeyoung Kim and Jeong-Bong Lee

Chapter 10 **Effect of Certain Ethylene Oxide Heterogeneous**

Chapter 11 **Recent Advances in the Methods for Designing Superhydrophobic Surfaces 311**

Chapter 12 **Lipid Self-Spreading on Solid Substrates 337**

**on Wetting 289** Calin Jianu

**Section 3 Surfaces 263**

**VI** Contents

**the Spread, Percutaneous Hazard, and Contact Dynamics for Nonporous and Porous Substrates and Membranes 205** Navaz Homayun, Zand Ali, Gat Amir and Atkinson Theresa

> The words "hydro", "phobic" and "philic" are derived from Greek and they mean water, fear and adoration respectively. These words are being used to define the interaction of wa‐ ter and other materials. As an example, these words are being used in classification of liq‐ uids and solids based on their solubility in water, as well as classification on the solid surfaces regarding to their wettability. A lot of surfaces in the nature have Superhydropho‐ bic and self-cleaning properties. For example the wings of a butterfly, leaves of some plants, including cabbage and Indian Cress, have the mentioned properties. The best example is the LOTUS leaf.

> The electron microscope pictures of the lotus leaf show some protrusion parts which have a 20-40 μm distance from each other and are being covered with a rough surface with a waxy structure. A numerous studies confirm that this coarsened structure is a combination of mi‐ cro and Nano meter scale which have a low surface energy; and this combination causes a contact angle higher than 150° and a low slide angle and self-cleaning effect. Surfaces with such properties are called "Superhydrophobic". Some natural examples don't show this two scaled structure and there are some questions about the necessity of this two scaled struc‐ ture, which are going to be discussed in section 2 from the wettability point of view. Before 1996, there were a few attentions to the superhydrophobic surfaces which were based on the connection of the static contact angle of the water and the geometry of the rough surface. In 1997 two German botanist, Neinhuis and Barthlott, using SEM discovered the two scaled structure of the lotus leaf and investigated its chemical composition. That study was a revo‐ lution, which revealed two important guidelines for researchers who study on superhydro‐ phobic surfaces. First one is the roughening of the surface of materials with low surface energy and the second one is modification and creation of the rough surfaces using low sur‐ face energy materials. So the unusual surface wettability in the nature can be created by con‐ trolling the microstructure of the geometry of the surface and low surface energy. After that discovery (by German scientists) a lot of research and review articles related to the superhy‐ drophobic surfaces were published, explaining the applications of the superhydrophobic surface in the day life. These applications include self-cleaning windscreen of the car, optical equipment, windowpanes ,and anti fog and anti corrosion coatings.

> This book collects new developments in the science of surface energy. I like to express my gratitude to all of the contributors for their high quality manuscripts. I hope open access format of this book will help all researchers and that they will benefit from this collection.

> > **Dr. Mahmood Aliofkhazraei** Tarbiat Modares University Iran www.aliofkhazraei.com

**Section 1**
