Refreshments served at 2:45 PM
Development of Nanostructured Membranes for Water Purification and Gas Separations
Abstract: Advances in membrane technology are largely driven by improvements in membrane materials and understanding of their transport properties. In this talk, I will discuss our recent work on two types of nanostructured membranes for water purification and gas separations. The first class of membranes for water desalination employs short hydrophobic nanopores that allow for transport via nearly isothermal evaporation and condensation between two menisci separated by sub-micrometer gaps. This design combines the advantages of thermal processes and reverse osmosis and has the potential for enhanced flux and resistance to anti-biofouling agents. The second class of membranes uses porous graphene as the selective material. Transport measurements have elucidated the role of intrinsic defects that allow for partially selective transport of molecules through graphene. We have also developed methods to create tunable, sub-nanometer pores in graphene using a nucleation and growth process and demonstrated that the process enables us to tune the selectivity of macroscopic graphene membranes. I will also discuss our progress towards further development of these membranes for separation of gases and small molecules/ions, which requires strategies to mitigate the effect of flow through intrinsic defects. These membranes have potential applications in a variety of filtration processes and gas separations with enhanced flux and tunable transport properties that are not be easily accessible in other membrane materials.
Biography: Rohit Karnik is Associate Professor of Mechanical Engineering at the Massachusetts Institute of Technology, where he leads the Microfluidics and Nanofluidics Research Group. His research focuses on the physics of micro- and nanofluidic flows and design of micro- and nanofluidic devices for applications in healthcare, energy systems, and bioanalysis. He obtained his B.Tech. degree from the Indian Institute of Technology at Bombay in 2002, and his Ph.D. from the University of California at Berkeley in 2006 under the guidance of Prof. Arun Majumdar. After postdoctoral work with Prof. Robert Langer, he joined the Department of Mechanical Engineering at MIT in 2007. Among other honors, he is a recipient of the Institute Silver Medal (IIT Bombay, 2002), NSF Career Award (2010), Keenan Award for Innovation in Undergraduate Education (2011), and DOE Early Career Award (2012).
Faculty Host: Chuanhua Duan
Student Host: Constantinos Katevatis