Zero internal concentration polarization FO membrane: functionalized graphene

Abstract

Reducing internal concentration polarization (ICP) and increasing water flux are essential for forward osmosis (FO) efficiency. Here, we use functionalized porous-single-layer graphene as a FO membrane and study its permeation properties via molecular dynamics simulations. Our results indicate that the ICP decreases to zero during FO processes, and that the water flux of graphene oxide reaches 91.5 L per cm² per day, which is about 1.7 × 10³ times higher than that of typical cellulose triacetate FO membranes. Furthermore, no forward or reverse solutes passing through the membrane are observed when the pore-diameter is smaller than 9.4 Å. This work may bring potential opportunities for functionalized porous graphene in water desalination, FO power generation and so forth.