Confined water transport and desalination mechanism through lamellar Boron-Nitride Channels: A molecular dynamics simulation study

Abstract

The lamellar channels created by hexagonal boron nitride sheets (hBNSs) offer great promise as membranes for RO desalination plants. However, boron nitride nanochannels (BNNCs) have not yet been extensively explored for their desalination mechanisms. Therefore, to address this gap of knowledge, in this study, molecular dynamics simulations (MDs) are used to investigate the performance of BNNCs in water desalination applications. For this purpose, the effect of various parameters, including channel height in the range of 6.14 Å to 12.38 Å, applied pressure, ion concentration, and membrane flexibility are evaluated. Results show that for channel height ranging 6.14 Å to 8.77 Å, the rejection percentage of double-charged ions is more than single-charged ions. In contrast, this trend is reversed for larger channel heights. Another important point is that 7.675 Å can be selected as an optimum channel height for a design of BNNC membranes. Moreover, the water permeation and ion rejection of flexible membrane decrease and increase, respectively, compared to the rigid membrane. In addition, the Boron Nitride-Nanoflake nanochannel membranes (BNFNC) are investigated as a realistic model of nanosheet-based membranes. Finally, the results of the present study propose that BNNCs can be an appropriate membrane for RO desalination plants.