Abstract
Prabal K Maiti: „Structure and dynamics of water confined in narrow carbon nanotube and nanoring”
Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, India
We study the various translational and orientational dynamics of water molecules confined inside carbon nanotube using atomistic Molecular dynamics (MD) simulations. The water molecules inside the nanotube show solid-like ordering at room temperature and surprisingly exhibit Fickian diffusion instead of single-file even if the particles can not cross one another. We propose model systems where single-file diffusion can be observed and test the prediction doing simulation in a nanoring. The confinement leads to strong anisotropy in the reorientational relaxation of the confined water molecules. The time scale of the relaxation of the dipolar correlations become ultra-slow. In contrast, the relaxation of the vector that joins the two hydrogens in a molecule becomes much faster. The relaxation proceeds by angular jumps between the two stable states. These jumps cause the ratio of the timescales of the first and second order reorientational correlation functions to exceed the value in the diffusive limit.