The advent of nanotechnology
has seen a growing interest in the
nature of fluid flow and transport under nanoconfinement. The present
study leverages fully atomistic molecular dynamics (MD) simulations
to study the effect of nanochannel length and intrusion of molecules
of the organic solvent, hexafluoro-2-propanol (HFIP), on the dynamical
characteristics of water within it. Favorable interactions of HFIP
with the nanochannels comprised of single-walled carbon nanotubes
traps them over time scales greater than 100 ns, and confinement confers
small but distinguishable spatial redistribution between neighboring
HFIP pairs. Water molecules within the nanochannels show clear signatures
of dynamical slowdown relative to bulk water even for pure systems. The
presence of HFIP causes further rotational and translational slowdown
in waters when the nanochannel dimension falls below a critical length
of 30 Å. The enhanced slowdown in the presence of HFIP is quantified
from characteristic relaxation parameters and diffusion coefficients
in the absence and presence of HFIP. It is finally seen that the net
flow of water between the ends of the nanochannel shows a decreasing
dependence with nanochannel length only when the number of HFIP molecules
is small. These results lend insights into devising ways of modulating
solvent properties within nanochannels with cosolvent impurities.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.