Comparison study on surface and thermo-chemical properties of PFPE lubricants on DLC film through MD simulations

Molecular dynamics simulations are performed using four types of PFPE lubricants (Zdol, Ztetraol, TA-30, and ZTMD) to investigate their spreadability, airshear behavior, surface contamination, and friction. The more functional end groups in PFPE lubricants the less spreadability on DLC surface, which agrees with the experimental results. The airshear simulation shows that the tangential shear movement of lubricants reduces as the number and the polar strength of functional end group increases. The higher temperature, the more shear displacement due to the increasing mobility. In HDI contact simulations, the PFPE lubricant with more and stronger functional end groups results in higher friction force and less head contamination by lubricant transfer. The higher temperature, the more head contamination but lower friction force.

Automated summary

The more functional end groups in PFPE lubricants, the worse their spreadability and the higher the friction. As temperature increases, lubricant mobility increases, leading to lower friction.