Superhydrophobic Surfaces via Nano-Emulsion Polymerization
Preface:
Non-wettable surfaces with high water contact angles (WCAs) and facile sliding of drops, called superhydrophobic or ultrahydrophobic, have received tremendous attention in recent years, both in academia and in industrial applications. These surfaces are of special interest because properties such as antisticking, anti-contamination and self-cleaning are expected. During last half century, many methods of imparting hydrophobic character to cotton have been developed that includes the use of hydrophobic polymer films and attachment of hydrophobic monomers via physical or chemical sorption processes.
Difference between Hydrophobic & Superhdyrophobic:
- Hydrophobic Surfaces: “Water-fearing surface” Water tries to minimize contact with surface or surfaces with a contact angle θc > 90°. Examples: Teflon, oily surfaces.
Superhydrophobic Surfaces: Hydrophobic surface having nano-scale roughness or surfaces with a contact angle θc > 150°
Materials in an Emulsion Polymerization:
The formulation and application of polymeric nano particles dispersed in non-solvent, so-called polymer latexes enjoy great popularity in academia and industry.
The main components of an emulsion polymerization system are the monomer(s), dispersing medium, emulsifier and water soluble initiator. The dispersing medium is usually water, in which the various components are dispersed by means of the emulsifier.
Approaches to Produce Hydrophobic Surfaces:
Techniques to make super hydrophobic surfaces can be simply divided into two categories:
· By surface modification i.e by making a rough surface
· By the application of chemical finishes.
The main challenge in this area is to achieve a durable non-fluoro hydrophobic finish with better latex stability. Based on the above challenges the main aim of this study would be to prepare a durable superhydrophobic finish and a suitable application method on to textiles.
Applications:
Applications of superhydrophobic surfaces are interesting because self-cleaning and antisticking properties of the surfaces are prominent. These properties are desirable for many industrial and biological applications. In the textile industry, manufacture of water-proof, fire-retardant clothes, medical and military end-uses, as well as those for everyday life uses, such as beach umbrellas, shade shelters, camps, garments, and advertisement materials can be obtained from superhydrophobic surfaces.
Applications of super hydrophobic surfaces
Achievements:
Hydrophobic polymer was synthesized using three different kind of hydrophobic monomer and reactive monomer by emulsion polymerization technique. Using dilute solution of emulsion enhanced the hydrophobicity of cotton fabric that it has taken maximum of 7 h to spread the water drops. Also after vigorous washing it was found maximum of 6 h to spread the water drop.