Molecular dynamics studies of the stability of water/n-heptane interfaces with adsorbed naphthenic acids

Molecular dynamics (MD) simulation is used to study the stability and molecular origin of nanometer-sized water clusters in n-heptane, with the full coverage of adsorbed 6-methyl-2-naphthatenepropionic acid at the water/n-heptane interfaces, at two temperatures. The results show that the coalescence of two water clusters fully covered by naphthenic acid molecules is a low-probability event even at evaluated temperatures and the mobility of naphthenic acids is enhanced with more n-heptane molecules present outside a water droplet.