1 research outputs found
Density Functional Investigation of the Adsorption of Isooctane, Ethanol, and Acetic Acid on a Water-Covered Fe(100) Surface
The
presence of water in biofuels poses the question of how it affects
the frictional performance of additives in fuels containing organic
substances. To investigate the effect of water on the adsorption of
molecules present in fuel and its additives we simulated within the
framework of density functional theory the adsorption of ethanol,
isooctane (2,2,4-trimethylpentane), and acetic acid on a bare and
a water-covered Fe(100) surface. Van der Waals interactions are taken
into account in our computations. In those molecules, where dispersion
forces contribute significantly to the binding mechanism, the water
layer has a stronger screening effect. Additionally, this effect can
be enhanced by the presence of polar functional groups in the molecule.
Thus, with the introduction of a water layer, the adsorption energy
of isooctane and ethanol is reduced but it is increased in the case
of the acetic acid. The adsorption configuration of ethanol is changed,
while the one of acetic acid is moderately, and for isooctane only
very slightly altered. Therefore, the effect of a water layer in the
adsorption of organic molecules on an Fe(100) surface strongly depends
on the type of bond and consequently, so do the tribological properties