M. Scott Shell

University of California- Santa Barbara
Professor, Department of Chemical Engineering

Topic: Simulation design of interfaces through shape and chemistry

The patterning of interfaces, both chemical and structural, directs an enormous range of thermodynamic and dynamic properties of the fluids that meet them. Here, we present two examples where molecular simulations allow systematic charting of the effects of different interfacial configurations, which in turn offers design principles for engineering desired structures and behaviors. In the first, we examine a route to chiral surfaces through the selfassembly of achiral, quasi 2D colloidal particles of tunable shapes. We show that a surprisingly simple mechanism, based only on excluded volume interactions, can drive achiral particles into chiral materials. The mechanism quantitatively explains recent experimental results, predicts new chiralprone shapes, and suggests a way that chiral structures might emerge in nature. In the second part, we show that precise hydrophobic/hydrophilic chemical patterning on a variety of solid surfaces provides an important way to control the dynamic behavior of adjacent water. We develop a novel genetic optimization algorithm, coupled to iterative molecular dynamic simulations, that designs the arrangement of surface groups so as to minimize or maximize the diffusion nearby water. Surprisingly, the algorithm uncovers novelsurface designs that produce a wide range of dynamics for a given constant average surface hydrophobicity fraction. We provide a molecular thermodynamic interpretation of these results using water structural order parameters.

Biography

Prof. M. Scott Shell is Professor and Vice Chair of Chemical Engineering at the University of California Santa Barbara.  He earned his B.S. in Chemical Engineering at Carnegie Mellon in 2000 and his Ph.D. in Chemical Engineering from Princeton in 2005, followed by a postdoc in the Department of Pharmaceutical Chemistry at UC San Francisco from 2005-07.  Prof. Shell’s group develops novel molecular simulation, multiscale modeling, and statistical thermodynamic approaches to address problems in contemporary biophysics and soft condensed matter. Recent areas of interest include self-assembled peptide materials, nanobubbles, hydrophobic interfaces, colloidal physics, and nanoparticle-membrane interactions.  He is the recipient of a Dreyfus Foundation New Faculty Award (2007), an NSF CAREER Award (2009), a Hellman Family Faculty Fellowship (2010), a Northrop-Grumman Teaching Award (2011), a Sloan Research Fellowship (2012), a UCSB Academic Senate Distinguished Teaching Award (2014), the Dudley A. Saville Lectureship at Princeton (2015), and the CoMSEF Impact Award from AIChE (2017).

Wednesday, April 18, 2018

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M. Scott Shell, Professor

University of California- Santa Barbara