Detroit, MI 48201
Anish Tuteja, from the Department of Materials Science and Engineering, University of Michigan, presents: Designing Surfaces with Extreme Wettabilities
In this talk I will discuss the theoretical and experimental work in my group on developing surfaces with extreme wettabilities, i.e. surfaces that are either completely wet by, or completely repel, polar and/or non-polar liquids. The first portion of the talk will cover the design of so called “superomniphobic surfaces” i.e. surfaces which repel all liquids. Designing and producing textured surfaces that can resist wetting by low surface tension liquids such as various oils or alcohols has been a significant challenge in materials science, and no examples of such surfaces exist in nature. As part of this work, I explain how re-entrant surface curvature,in addition to surface chemistry and roughness, can be used to design one of the first ever surfaces that causes virtually all liquids, including concentrated organic and inorganic acids, bases and solvents, as well as, viscoelastic polymer solutions to roll-off and bounce.
The second portion of my talk will cover the design of the first-ever reconfigurable membranes that, counter-intuitively, are both superhydrophilic (i.e., water contact angles ~ 0 degree)and superoleophobic (i.e., oil contact angles > 150 degrees). This makes these porous surfaces ideal for gravity-based separation of oil and water as they allow the higher density liquid (water) to flow through while retaining the lower density liquid (oil). These fouling-resistant membranes can separate, for the first time, a range of different oil–water mixtures, including emulsions, in a single-unit operation, with > 99.9% separation efficiency, by using the difference in capillary forces acting on the oil and water phases. As the separation methodology is solely gravity-driven, it is expected to be one of the most energy-efficient technologies for oil-water separation.
Finally I will discuss some other areas of current and future research, including the development of ice-phobic coatings that offer one of the lowest adhesion strengths with ice that have ever been reported.