The Structure and Dynamics of Patterned Nanospheres
Professor Rigoberto Hernandez
School of Chemistry and Biochemistry, Georgia Institute of Technology

Abstract: Colloidal dispersions have been useful for many applications, particularly because of the balance of microscopic heterogeneity and the wealth of tunable properties they exhibit at macroscopic length scales.  At the small extreme of nanoparticles, the patterning on the surface can be controlled through chemistry.  An assembly of nanospheres can consequently exhibit a wealth of structural properties.  Perhaps surprisingly, Janus particles (those with oppositely charged hemispheres), were seen to exhibit similar equilibrium structure as uniformly interacting particles [J. Chem. Phys. 137, 044505 (2012)]. Their dynamics, however, are quite sensitive to the patterning of the surface [J. Chem. Phys. 138, 184903 (2013)].  Course-graining of the particles into spherically symmetric interactions leads to different time scales in the structuring of the particles than that which can be captured by time-rescaling or uniform dissipative mechanism.  Higher-multiplicity striped particles (beyond the two found in Janus particles) offer the possibility that commensurability in the overlap of the stripes can give rise to dramatic density effects on their structure [J. Chem. Pnys., 140, 034701 (2014)]. We will report the behavior for a range of stripes up to seven and examine the trends for even and odd patterns.

Bio: Dr. Rigoberto Hernandez is a Professor in the School of Chemistry and Biochemistry at Georgia Tech, a Co-Director of the Center for Computational Molecular Science and Technology and the Director of the Open Chemistry Collaborative in Diversity Equity (OXIDE). He holds a B.S.E. in Chemical Engineering and Mathematics from Princeton University (1989), and a Ph.D. in Chemistry from the University of California, Berkeley (1993). His research interests can be broadly classified as the theoretical and computational chemistry of systems far from equilibrium. This includes a focus on microscopic reaction dynamics and their effects on macroscopic chemical reaction rates in arbitrary solvent environments. Dr. Hernandez is the recipient of a National Science Foundation (NSF) CAREER Award (1997), Research Corporation Cottrell Scholar Award (1999), the Alfred P. Sloan Fellow Award (2000), a Humboldt Research Fellowshp (2006-07), and the ACS Award for Encouraging Disadvantaged Students into Careers in the Chemical Sciences (2014). He is a Fellow of the American Association for the Advancement of Science, the American Chemical Society, and the American Physical Society. He is also currently a member of the American Chemical Society Board of Directors.