The Coating Techniques of Thin Film

**189**

**Chapter 11**

**Abstract**

Electrospinning Technique as a

Powerful Tool for the Design of

*Pedro J. Rivero, Adrian Vicente and Rafael J. Rodriguez*

**Keywords:** electrospinning, superhydrophobicity, wettability properties,

superoleophobic (CA > 150°) [5] behavior measured by using oil droplets.

The measurement of the contact angle (CA) value is one of the most important parameters used for the determination and quantification of the wettability of solid surfaces. This CA is used to describe the behavior of a liquid droplet on a solid surface in air and is measured as the angle between the tangent at three phase points and the solid surface [1]. Accordingly, a surface is considered hydrophilic when the resultant solid surface shows a water contact angle (WCA) less than 90°, whereas a solid surface is considered hydrophobic when the WCA is higher than 90°. Nowadays, due to the development of the nanotechnology, bioinspired surfaces with special wettability properties are continuously emerging in the scientific research areas. Some representative examples are the design of novel surfaces with superhydrophilic (WCA < 10°) [2] or superhydrophobic (WCA > 150°) [3] behavior measured by water as well as surfaces with superoleophilic (CA < 10°) [4] or even

polymeric precursors, industrial applications

**1. Introduction**

The development of surface engineering techniques to tune-up the composition, structure, and function of materials surfaces is a permanent challenge for the scientific community. In this chapter, the electrospinning process is proposed as a versatile technique for the development of highly hydrophobic or even superhydrophobic surfaces. Electrospinning makes possible the fabrication of nanostructured ultrathin fibers, denoted as electrospun nanofibers (ENFs), from a wide range of polymeric materials that can be deposited on any type of surface with arbitrary geometry. In addition, by tuning the deposition parameters (mostly applied voltage, flow rate, and distance between collector/needle) in combination with the chemical structure of the polymeric precursor (functional groups with hydrophobic behavior) and its resultant viscosity, it is possible to obtain nanofibers with highly porous surface. As a result, functionalized surfaces with water-repellent behavior can be implemented in a wide variety of industrial applications such as in corrosion resistance, high efficient water-oil separation, surgical meshes in biomedical applications, or even in energy systems for long-term efficiency of dye-sensitized solar cells, among others.

Superhydrophobic Surfaces
