The Impact of Pore Geometry on Frictional Properties of hBN and MoS₂ Nanomaterials

Two-dimensional (2D) nanomaterials hold significant promise for reducing energy consumption in water desalination. This study investigates the influence of pore size and shape on the slip behavior of saline water at the interface of two promising 2D nanomaterials: hexagonal boron nitride (hBN) and molybdenum disulfide (MoS₂). Slip length, a key parameter governing fluid flow at the nanoscale, is highly dependent on interfacial properties. Here, we explore how the pore characteristics in these 2D nanomaterials can impact slip length, aiming to gain a fundamental understanding of the role of pore size and shape in optimizing desalination efficiency. We performed quantum mechanical calculations to compute the partial atomic charges on atoms in hBN and MoS₂ containing pores. Our DFT calculations reveal a spatially varying charge distribution on these 2D nanomaterials with pores, which we then incorporate into molecular dynamic simulations to elucidate their influence on the 2D nanomaterial-water interface. Our results reveal a significant impact of pore size on friction for nanomaterials containing hexagonal pores, while pore size had no effect on nanomaterials containing triangular pores. Moreover, friction increases with pores in both materials. This research contributes to the development of efficient and energy-saving desalination technologies through the manipulation of interfacial properties in 2D nanomaterials.