|About this Abstract
||Materials Science & Technology 2019
||Late News Poster Session
||P3-111: Frictional Behaviour of 2-D Materials -- MoS2 and Graphene -- in Different Environments
||Ahmet T. Alpas, Zaixiu Yang, Fatih G Sen, Sukanta Bhowmick
|On-Site Speaker (Planned)
||Ahmet T. Alpas
2-D materials like graphene and MoS2 are being increasingly used as additives to metal cutting fluids and also as surface coatings to improve the tribological efficiency of sliding components. Friction experiments and first-principles calculations were performed to study the sliding friction behaviour of MoS2 under different environments in comparison to that of graphene. It was found that dissociative adsorption of water molecules at a mono-vacancy site of the graphene led to the increase in the graphene layer spacing and reduced interlayer binding energy EB, and thus contributed to low coefficient of friction (COF) of graphene under humid environments. On triple vacancy sites of MoS2 water dissociation into O and 2H occurred with EB of MoS2 layers remaining the same as that of pristine MoS2. The undissociated water molecules physically adsorbed between the bilayer MoS2 led to an increase of EB. Thus, MoS2 exhibited a high COF in humid atmospheres.