Massachusetts Institute of Technology
Location - Tech L211
Hosted by the Ryan Fellows
Our laboratory has been interested in how 1D and 2D electronic materials such as carbon nanotubes and graphene, respectively, can be utilized to illustrate new concepts in molecular transport and energy transfer. My talk will highlight recent efforts in my laboratory along these lines. In the first example, we predict and demonstrate the concept of thermopower waves for energy generation. Coupling an exothermic chemical reaction with a thermally conductive CNT or graphene creates a self-propagating reactive wave driven along its length. We realize such waves in 1D and 2D conduits and show that they produce concomitant electrical pulses of high specific power >7 kW/kg. Recent work has lead us to the Theory of Excess Thermopower to describe these voltage waves, showing that they are necessarily larger than conventional thermoelectric devices. We have also developed a theory of Superadiabacity, showing that reaction waves of this type can generate temperatures in excess of the adiabatic limit. Such waves of high power density may find uses as unique energy sources, including new fuel cells and thermal batteries. Next, I introduce CoPhMoRe or corona phase molecular recognitionas a method invented at MIT for discovering what can be thought of as nanoparticle coupled synthetic antibodies, or recognition sites formed from a specifically designed heteropolymer library. We show that certain synthetic heteropolymers, once constrained onto a single-walled carbon nanotube by chemical adsorption, form a new corona phase that exhibits highly selective recognition for speciﬁc molecules. I will highlight recent examples allowing us to detect a wide range of challenging molecules, from neurotransmitters, to explosives, carbohydrates, and protein components in whole blood. The ability to generate synthetic recognition sites that are non-biological in origin has potential to extend robust chemical detection to harsh environments. I will also outline our recent success in extending these platforms for in-vivo recognition. I’ll also highlight our recent efforts to initiate a new research endeavor of plant nanobionics whereby we use techniques to deliver and transport functional nanoparticles into living plants to grant them non-native functions. I’ll highlight these techniques and some of our nanobionic plant prototypes. Finally, I discuss our efforts to study the nanopore transport and thermodynamics through the narrowest straight-line nanopores of single walled carbon nanotubes. We fabricate and study SWNT ion channels exploring ion transport in the diameter range of 0.9–2 nm for the first time. We observe a surprising fivefold enhancement of stochastic ion transport rates for single-walled carbon nanotube centered at a diameter of approximately 1.6 nm. An electrochemical transport model informed from literature simulations is used to understand the phenomenon. We also observe rates that scale with cation type as Li > K > Cs > Na and pore blocking extent as K > Cs > Na > Li potentially reflecting changes in hydration shell size. Across several ion types, the pore-blocking current and inverse dwell time are shown to scale linearly at low electric field. This work opens up new avenues in the study of transport effects at the nanoscale. I will also discuss our recent work exploring aqueous phase transitions in the interior of nanotubes of this type, showing significant departures from the Gibbs Thomson equation.
Professor Michael S. Strano is currently the Carbon P. Dubbs Professor of Chemical Engineering at the Massachusetts Institute of Technology. He received his B.S from Polytechnic University in Brooklyn, NY and Ph.D. from the University of Delaware both in Chemical Engineering. He was a post doctoral research fellow at Rice University in the departments of Chemistry and Physics under the guidance of Nobel Laureate Richard E. Smalley. From 2003 to 2007, Michael was an Assistant Professor in the Department of Chemical and Biomolecular Engineering at the University of Illinois at Urbana-Champaign before moving to MIT. His research focuses on biomolecule/nanoparticle interactions and the surface chemistry of low dimensional systems, nano-electronics, nanoparticle separations, and applications of vibrational spectroscopy to nanotechnology. Michael is the recipient of numerous awards for his work, including a 2005 Presidential Early Career Award for Scientists and Engineers, a 2006 Beckman Young Investigator Award, the 2006 Coblentz Award for Molecular Spectroscopy, the Unilever Award from the American Chemical Society in 2007 for excellence in colloidal science, and the 2008 Young Investigator Award from the Materials Research Society, the 2008 Allen P. Colburn Award from the American Institute of Chemical Engineers, the 2009 Office of Naval Research, Young Investigator Award and selected as a member of Popular Science’s Brilliant 10 in 2009, 2011 Thompson Reuters, Ranked 19th of the Top 20 Chemists of the Decade 2000-2010, 2011 Kavli Frontiers of Science Fellow, National Academy of Sciences, 2012 Nanoscale Science and Engineering Forum Award, American Institute of Chemical Engineering, 2014 Blavatnik National Award for Young Scientist (Finalist; Chemistry) and 2014 Selection for Defense Science Study Group, Department of Defense.