Water and the Hydrophobic Interaction in X10,000,000 Magnification

The governing role of hydrophobic interactions in countless biological phenomena and technological systems, including protein folding, transmembrane proteins, cell membranes, detergents, paints, decontamination of pollute water, and more, has motivated extensive theoretical and experimental efforts aimed at deciphering the microscopic foundations of this interaction. Yet, after more than a century of extensive research a full predictive theory of this elusive phenomenon is still missing, largely due to the lack of suitable experimental techniques capable of probing the interface between hydrophobic surfaces and water at high enough resolution. In the talk, I will present our recent explorations of this interface using an ultra-high resolution atomic force microscope built in-house for the task and disclose compelling evidence that the hydrophobic interaction reflects a phase transition taking place in the medium when two hydrophobic surfaces approach each other to within a few nanometers. Along the way I'll demonstrate the sub-atomic resolution of our microscope and its value for the study of water structure near surfaces and biomolecules.