A computer simulation study of stick-slip transitions in water films confined between model hydrophilic surfaces. 1. Monolayer films.
The shear behavior of monolayer water films confined in a slit-like pore between hydrophilic walls is simulated in the quasistatic regime using the grand canonical Monte Carlo technique. Each wall is represented as a hexagonal lattice of force sites that interact with water through an orientation-dependent hydrogen-bonding potential. When the walls are in registry, the water oxygen atoms form either a crystal- or fluid-like structure, depending on the period of the wall's lattice. In both cases, however, the monolayer structure is orientationally disordered. Both the crystal- and fluid-like monolayers prove to be capable of experiencing well-defined stick-slip transitions, with the largest yield stress occurring in the crystal-like case. Beyond the yield point, the crystal-like monolayers "melt", but their structure and molecular motion differ in many respects from those characteristic of normal fluids.
Pertsin
Alexander
A
Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany.
Grunze
Michael
M
D003198:Computer Simulation; D003460:Crystallization; D006860:Hydrogen Bonding; D046911:Macromolecular Substances / Q000737:chemistry*; D008566:Membranes / Q000737:chemistry*; D008956:Models, Chemical; D010100:Oxygen / Q000737:chemistry; D033081:Shear Strength; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
D046911:Macromolecular Substances; D014867:Water; D010100:Oxygen