Fast reverse osmosis using boron nitride and carbon nanotubes

We investigate reverse osmosis through commonly used polymeric and advanced inorganic nanotube based semipermeable membranes by performing nonequilibrium molecular dynamics simulations. Simulations indicate that there is a significantly higher water flux through boron-nitride nanotube (BNNT) and carbon nanotube (CNT) compared to a polymethyl methacrylate (PMMA) pore, and a slightly higher water flux through BNNT as compared to CNT. The calculated permeation coefficient is in reasonable agreement with the theoretical single-file “hopping” model. Potential of mean force analysis indicates that the irregular nature of PMMA pore surface can cause significant localized energy barriers inside the pore, thereby reducing the water flux.