A team of researchers from the National University of the South in Bahia Blanca, Argentina have analysed the condition required for hydrophobic cavities and similar tunnel structures that is similar to the protein binding sites to remain dry without losing their capability to react.
This capability is highly essential for proteins in order to stablish consistent interactions with other proteins in aqueous solution. The research team had chosen an alkane-like monolayer to study its cavities, tunnels and tendencies to stay dry owing to it being hydrophobic.
The minimum size of a hydrophobic cavity to be filled with water is a nanometer. A smaller size than this must be inherently protected by a geometric umbrella that prevents it from getting wet. In case a water molecule was to enter in such small cavity then it has to shed one of its hydrogen bonds. However this is not the same case with carbon nanotubes that are two times smaller than the alkane like monolayer but less hydrophobic hence prone to getting wet sooner.
The nanometric cavities and tunnels eventually get filled as water molecules through an arrangement of hydrogen bonds network. With temperature variation the bond rupture resulting in the drying up of the cavities. However, these bonds re-appear when the temperature drops.
This study has greater application on water exclusion sites of proteins in biophysics owing to their geometry thereby enabling to understand the protein-protein linkages.
Source: http://www.epj.org