New Insights into Hydrophobic Interactions Encoded by Chemical Nanopatterns

Colloquium | November 29 | 4-6 p.m. | 180 Tan Hall

 Nicholas L. Abbott, University of Wisconsin-Madison

 Department of Chemical Engineering

The structuring of water near non-polar molecular fragments or surfaces mediates cohesive interactions (so-called hydrophobic interactions) that underlie a broad range of biophysical, colloidal and materials-related phenomena. Substantial progress has been made during the past decade towards understanding hydrophobic interactions in simple model systems, but in most biological and technological contexts, non-polar domains are found in close proximity to polar and charged functional groups. We are using conformationally-stable -amino acid oligomers, and single-molecule force measurements to elucidate hydrophobic interactions encoded by specific chemical nanopatterns. These measurements reveal, for example, that ions immobilized adjacent to non-polar domains can substantially increase or decrease the strength of hydrophobic adhesion, with the effect strongly dependent on the specific ion type. This understanding is providing a fresh starting point for molecular design in aqueous environments in a broad range of contexts.