A New Biomimetic Approach to Superhydrophobic Nanocomposite Coating Materials Inspired by Natural Materials (Lotus Leaf and Duck Feather)

Soha M. Albukhari (Advisor: Dr. Patricia Heiden)

Doctoral Student, Department of Chemistry, Michigan Technological University

November  17, 2014 – 8:30 am – Fisher Hall, Room 126

Abstract:

This proposal describes a novel approach to create of superhydrophobic polymeric nanocoating materials, inspired by the water-repellant properties in two natural materials, lotus leaves and duck feathers. The process combines simple synthetic techniques with coaxial electrospinning and ultrasonication techniques to form a novel, reinforced superhydrophobic and self-cleaning coating on a glass substrate. To accomplish this we prepare a PMMA-grafted graphene suspension and a fluorinated silica nanoparticle suspension. These two fluids were used in coaxial electrospinning to produce a novel core-sheath nanofiber coating material with a dual superhydrophobic structure that mimics the critical structures in duck feathers and lotus leaves. These features are expected to give nanocomposite micro-nano core-sheath fibers that will impart superhydrophobic properties by increasing the water contact angle (CA) to more than 150º, and give a self-cleaning surface by having a water roll-off angle of less than 10º. These values are also expected to make the surface resistant to icing. Such a dual biomimetic structure has never been produced before, and by combining these features we will be able to study how these two differently functioning structures interact. The basic purpose of the PMMA-graphene core is to fill the air space in the micro-nano helix of the core-sheath nanocomposite by forming a cushion on the fiber-water interface, decreasing its surface wettability. Moreover, graphene electro-conductivity provides anti-icing properties and adds mechanical strength to the coating, so if the sheath layer fails, the graphene layer will still function independently. Studying this new dual-mimetic material may reveal new information about morphology and nanostructures that impart superhydrophobicity, which has value for coating applications such as airplane wings, sidewalks, car windshields, runways, and roads.