Dr. Eui-Hyeok Yang
Professor Department of Mechanical Engineering Stevens Institute of Technology Castle Point on the Hudson, Hoboken
Title: Controlled Adhesion of Liquid Droplets on Smart Surfaces
Biography
Biography: Dr. Eui-Hyeok Yang
Abstract
The control of adhesion of liquid droplets on solid substrates has broad implications in surface cleaning, water treatment, microfluidics, biochemistry, and lab-on-a-chip devices. An earlier report using a conjugated polymer, polyaniline (PANI) doped with dodecylbenzene sulfonic acid (DBSA), demonstrates the control of the contact angle of a liquid droplet. Poly(3,4-ethylenedioxythiophene(PEDOT) polymers bearing imidazolium ionic-liquid moieties (PEDOT-Im) show multi-responsive properties to a variety of stimuli, such as temperature, pH, oxidative doping, and the presence of anions. Recently, there has been a growing number of reports concerning the liquid adhesion and wetting on polypyrrole surfaces. Here we show the development and application of smart polymer functional surfaces using dodecylbenzenesulfonate-doped polypyrrole (PPy(DBS)); we demonstrate a novel in situ control of droplet pinning on the polymer surface, enabling the control of droplet adhesion from strongly pinned to extremely slippery (and vice versa). The pinning of organic droplets on the surfaces is dramatically controlled in situ, presenting a great potential for manipulation and control of liquid droplets for various applications including oil separation, water treatment and anti-bacterial surfaces. We believe that our work represents a major advance in materials science and engineering, especially pertaining to those topics that involve functional and tunable surfaces