Fracture behaviour of pristine and defective form of water submerged h-BN nanosheets

Abstract

Hexagonal boron nitride (h-BN) nanosheets are emerging as potential candidates to replace polymeric membrane for water purification. Synthesizing the membrane size of immaculate h-BN is a fictitious concept. So far, no articles have reported on the fracture behaviour of pristine and defective h-BN nanosheets in a water-submerged state. In this article, classical mechanics-based simulations were employed to study the effect of the hydrogen functionalization of sp-hybridized crack edge atoms and spatial distribution of Stone–Thrower–Wales (STW) and dislocation defects on the fracture properties of water-submerged h-BN nanosheets. Classical mechanics-based simulations were carried out with the help of hybrid-type interatomic potential in which reactive force field and transferable intermolecular potentials were used for arresting the atomistic interaction in h-BN and water, respectively, while for interfacial interactions, Lennard–Jones potential was employed. Enhancement in the values of fracture toughness of h-BN was investigated in the prescence of water molecules compared to in a dry state. It was deduced from the results that passivation, as well as the spatial distribution of STW defects, have a deteriorating effect on the values of fracture toughness of h-BN in the dry state, but water molecules help in nullifying a negative affect. Compared to the spatial distribution of dislocations, the STW type of defects have a more pronounced effect on the values of fracture toughness of h-BN water-submerged state. It can be predicted from the simulations that these improved fracture toughness values in a water-submerged state will help in developing these nanosheets as an effective desalination membrane in water purification.