Structure and Dynamics of n-Alkanol Monolayers on a Mica Surface

All-atom molecular dynamics simulations are conducted to understand the structural and dynamical behavior of self-assembled monolayer of n-alkanols on a mica surface. In particular, we report the effect of increasing carbon chain length (C1–C10) on the self-assembly, surface diffusion, and preferential tilting of n-alkanol monolayer, for monolayer surface coverage ranging from 6 × 10–5 to 3.54 × 10–3 mol/m2. The adsorption phenomena typically follow the Langmuir adsorption isotherm. However, the maximum adsorption is observed for n-hexanol, and it drops with further increase in the chain length. The surface diffusion coefficient, Ds, within monolayer, is nonmonotonic in nature. The maximum value of Ds decreases with increasing carbon chain length, with an exception of methanol owing to its preferential attachment with the cage of mica due to the presence of K+. The behavior of Ds is clearly explained using instantaneous autocorrelation function of hydrogen bonds with the surface. Further, Ds, is found to ...

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