A Theoretical Study of the Lubricating Abilities of 2D Layered Hydrogen Bonded Systems

It has been estimated that 100 million terajoules of energy is used every year to combat friction. For perspective, this corresponds to one fifth of the world’s total energy expenditure. This significant amount leaves plenty of room for improvement. To reduce the environmental and financial impact of friction, lubricants are usually placed in mechanical systems and act as a barrier between moving parts. Lubricants come in many forms but they all have low energy slip mechanisms and resistance to conformational change under pressure. Chemicals with these properties can be predicted through some educated guesswork and computational simulations. Its advantageous to look at novel lubricants computationally because each small reaction can be analyzed, whereas in the lab it may be difficult to see the molecular mechanisms taking place in such short time spans. Additionally, computation is more environmentally friendly than hands-on testing because no chemicals are used. My research studies compounds found in nature and assesses their potential for use as lubricants. The focus of my studies has been on layered systems of melamine molecules that self-assemble into two-dimensional structures through hydrogen bonding. The layered nature of this system is similar to that of graphite – an effective layered lubricant; however, the reversibility of self-assembly may allow the layered structure to reform when disrupted during sliding to increase the robustness of the system. In this presentation, I will discuss the results of my simulations, with an emphasis on the structure of the system, the slip mechanism, slip energetics and friction forces.