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Abstract
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Molecular dynamics simulation was applied to
study ethanol?water mixtures with different component
contents that were confined between graphene surfaces. The
effect of mixture component content and pore width on
structural and dynamic properties and percolation of confined
fluids were investigated and compared with the corresponding
properties in bulk. All dynamic properties of water molecules
significantly reduced because their movement is limited to a
space in the middle of the box. Water molecules percolated in
all mixtures and formed larger clusters compared to ethanol
molecules. Also, percolation in confined systems happened
with more probability compared to bulk systems. The
segregation was found in a way that a layered structure with
adsorbed ethanol molecules, with hydrophobe alkyl group, on
graphene surface was formed specially in smaller pore width
and dilute ethanol content mixtures. Diffusion coefficients of
water and ethanol molecules in mixture are approximately
comparable, so their different movement capability was balanced with interaction between water and ethanol. The ethanol?
water hydrogen bond strength is more than the ethanol?ethanol hydrogen bond strength in bulk mixtures while it is less than
its counterpart in the confined system, which is in agreement with segregation tendency in confined systems.
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