Water Structure and Properties at Hydrophilic and Hydrophobic Surfaces

Abstract

The properties of water on both molecular and macroscopic surfaces critically influence a wide range of physical behaviors, with applications spanning from membrane science to catalysis to protein engineering. Yet, our current understanding of water interfacing molecular and material surfaces is incomplete, in part because measurement of water structure and molecular-scale properties challenges even the most advanced experimental characterization techniques and computational approaches. This review highlights progress in the ongoing development of tools working to answer fundamental questions on the principles that govern the interactions between water and surfaces. One outstanding and critical question is what universal molecular signatures capture the hydrophobicity of different surfaces in an operationally meaningful way, since traditional macroscopic hydrophobicity measures like contact angles fail to capture even basic properties of molecular or extended surfaces with any heterogeneity at the nanometer length scale. Resolving this grand challenge will require close interactions between state-of-the-art experiments, simulations, and theory, spanning research groups and using agreed-upon model systems, to synthesize an integrated knowledge of solvation water structure, dynamics, and thermodynamics.

Identifying hydrophobic protein patches to inform protein interaction interfaces

“…However, even when the structure of a protein is available at atomistic resolution, it is challenging to identify its hydrophobic patches because they are not uniformly nonpolar, but display variations in polarity and charge at the nanoscale. Moreover, the emergent hydrophobicity of a protein patch stems from the collective response of protein hydration waters to the nanoscale chemical and topographical patterns displayed by the patch (14)(15)(16)(17)(18)(19)(20) and cannot be captured by simply counting the number of nonpolar groups in the patch, or even through more involved additive approaches, such as hydropathy scales or surface-area models (21)(22)(23)(24)(25)(26)(27)(28).…”

Microwave Enabled Physically Cross Linked Sodium Alginate and Pectin Film and Their Application in Combination with Modified Chitosan-Curcumin Nanoparticles. A Novel Strategy for 2nd Degree Burns Wound Healing in Animals

“…Both polymers, i.e., sodium alginate and pectin, contain a number of polar functional groups viz OH/NH 2 , amide-I and amide-II, which may interact with each other upon microwave treatment preferably through hydrogen bonds [ 63 ]. Exposition of surface hydrophilic functional groups enables attraction and/or interaction with more water molecules [ 64 ]. The blend film also contained additional hydrophilic ingredients namely tween 80 and glycerol.…”

Where Biology and Traditional Polymers Meet: The Potential of Associating Sequence-Defined Polymers for Materials Science

“…Currently, chemical intuition plays a significant role in selecting polymer sequences. While this approach has yielded powerful results, searching for increasingly intricate sequences based purely on intuition and experience will miss many optimal candidates, in part because optimal sequences are often nonintuitive and in part because a fundamental understanding of many self-assembly driving forces, for example, hydrophobicity, 131 is not fully developed. Armed only with limited predictive capabilities, many fantastic candidates will remain undiscovered in vast sequence design spaces.…”