(420r) The Role of Structure and Surface Composition on the Contact Angle and Wetting Characteristics of Carbon Nanofiber Coatings

Mazumder, S., Birla Institute of Technology and Science, Pilani

In recent years, superhydrophobic surfaces have attracted considerable interest because of their potential applications with great significance in various domains such as microfluidics, paints, and anticorrosive agents. The role of roughness and composition on the wetting characteristics of a series of carbon nanofiber based coatings were studied in order to evaluate its superhydrophobic properties.  In this study, idealized surfaces were created from a smooth stainless steel and aluminium plates and two other stainless steel plates with different textured surfaces.  All surfaces were coated with carbon nanofiber alcohol solutions in order to generate coatings of variable compositions using mixtures of isopropanol, water and a commercial carbon nanofibre. Nanofiber coatings of various concentration were created and studied in this work.  A general trend of increasing hydrophobicity was observed for coated surfaces as compared to the bare substrate.  Individual contact angles were dependent on the nature of the underlying substrate, relative surface pattern, and roughness.  Apparent surface contact angles on these substrates exhibited behavior that followed both the Wenzel and Cassie models.  Overall wetting properties were dependent upon composition and micro scale roughness of the coatings. 

Key words:  Contact Angle, Wetting, Wenzel and Cassie model, Coatings, Carbon Nanofibre, Superhydrophobicity