Molecular self-assembling structure and formation mechanism of lubricating grease: A computational simulation approach

Grease is an important type of lubricant. In this study, a computational simulation strategy suitable for revealing the self-assembled structure of grease and its formation mechanism is investigated by combining the advantages of quantum mechanics, molecular dynamics, and dissipative particle dynamics. The results show that the main driving force of self-assembly of thickener molecules in oil is electrostatic force; the molecular configuration of the thickener changes from a bending to a stretching state during the cooling process. The simulation methods developed in this work are successfully applied to study the formation mechanism of sodium stearate and potassium stearate grease, and the results are in good agreement with the experimental results.