Research Projects

Water's properties are significantly influenced by nanoscale confinement, which affects its molecular structure and dynamics. This research is crucial for applications in nanotechnology and biochemistry, such as water permeation, drug delivery, and desalination. However, experimental studies are challenging due to small length scales, making theoretical or computational approaches more useful. Accurate estimation of viscosity of nanoconfined water is essential for understanding diffusion and other physicochemical processes. The Green-Kubo equation can be used for computing viscosity of bulk water, but it cannot accurately provide viscosity due to system anisotropy. The Stokes-Einstein relation (SER) can be used to obtain viscosity through diffusion computation. However, the SER is violated in water, especially in a supercooled state. The translational jump-diffusion (TJD) approach, developed by the group, found that residual diffusion from small step displacements remains fairly coupled to viscosity. Instead of total diffusion, residual diffusion of water in the SER can be used to calculate the viscosity of confined water. This method requires calculating the translational jump-diffusion coefficient using the TJD approach and separates it from total diffusion to acquire the residual diffusion coefficient. This method can compute the viscosity of water under confinement and can be generalized for other liquids in more complex environments.

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