Wettability of Nanostructured Surfaces

There are many studies in literature concerning contact angle measurements on different materials/substrates. It is documented that textiles can be coated with multifunctional materials in form of thin films or nanoparticles to acquire character‐ istics that can improve the protection and comfort of the wearer. The capacity of oxide nanostructures to inhibit fungal development and neutralize bacteria is a direct consequence of their wetting behavior [1–6]. Moreover, the radical modification of wetting behavior of nanostructures from hydrophilic to hydrophobic when changing the pulsed laser deposition (PLD) ambient will be thoroughly discussed. When an implant is introduced inside the human body, its surface is first wetted by the physiological fluids. This further controls the proteins adsorption followed by the attachment of cells to the implant surface. Hence, surface wettability is considered an important criterion that dictates biocompatibility of the implant and could stand for a decisive factor for its long-term stability inside the human body. In Section 1 of this chapter, the reader is briefly introduced to wetting phenomenon, and correlations between well-known Young, Cassie, and Wenzel approaches are made. Next, one of the most spread techniques to measure the wettability of surface, the contact angle measurement, is thoroughly explained and relevant examples are given. Section 2 begins with a summarized table about previous works on synthesis of hydrophobic or hydrophilic nanostructures with a special focus on ZnO, SiOx, TiO2, and DLC materials. A short presentation of the advantages of their synthesis by PLD, sol-gel, thermal evaporation, solution based on chemical approaches, sputtering, and plasma enhanced chemical vapor deposition will be introduced. © 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Sections 3 includes a brief literature overview on results regarding synthesis by aforementioned techniques of different oxides (ZnO, TiO2, and SiOx) and DLC nanostructures onto textile (polyester, polyamide, cotton/polyester, and poly(lactic acid)) or metallic substrates for medical purposes. The chapter ends with conclusions and references, which include books and review articles relevant to the topics.