Molecular dynamics simulation on the adsorption behaviors of biodiesel components on iron surface

The adsorption behavior of typical components of biodiesel (eight fatty acid esters) on Fe(110) surface was investigated by using molecular dynamics(MD) simulations. The results indicated that the ester group or double bond was paralleled to the surface when the fatty acid ester molecule was adsorbed on the iron surface. The introduction of double bond or hydroxyl group in the fatty acid part or the chain length increase of the alcohol part led to a higher binding strength between the fatty acid ester molecule and the iron surface. More double bond or hydroxyl group could enhance the compactness of the adsorption film of fatty acid ester, and longer chain length of the alcohol part could increase the thickness of the adsorption film, because double bond or hydroxyl group caused an increase of cohesive energy mainly due to the increase of electrostatic interaction, and the chain length increase of alcohol part also caused a higher cohesive energy, which was mainly attributed to the increase of van der Waals interaction.