Fig. 2: Water vapor and liquid water transport through atomically thin graphene membrane with angstrom-scale pores.

A Schematic of the setup to measure water vapor transport—dynamic moisture permeation cell (DMPC) with mass flow controllers (MFCs), differential pressure meter (DP), back-pressure regulator (BPR), bubble flow meter (BPM), and relative humidity sensor (RHS). B Water vapor transmission rates (WVTRs) through bare PCTE and graphene membranes (GM) based on the effective membrane area (9.4% of total area) under different mean relative humidities (RHs) of 30 and 40%. C WVTRs of the fabricated GM (accounting for ~9.4% porosity of PCTE supports) and commercial breathable materials⁵⁴ (ePTFE, eVent, Neoshell, Gore-Tex, and Sympatex) measured under 30% \(\overline{{{{{{\rm{RH}}}}}}}\) with a constant RH difference of 50% across the membrane at 30 °C. Also, see Supplementary Fig. 2. D Schematic of the Side-Bi-Side diffusion cell used to measure liquid water as well as solute transport. E Water flux measured through bare PCTE and graphene membranes (GMs) under forward osmosis (FO) based on effective membrane area (9.4% of total area). Also, see Supplementary Fig. 5. F Solute rejections of KCl (~0.66 nm), NaCl (~0.716 nm), L-Tr (~0.7–0.9 nm), and B12 (~1–1.5 nm) through the fabricated GMs. Also, see Supplementary Fig. 7. G Schematic of the custom-made hydrostatic pressure-driven cross-flow reverse osmosis (RO) system for liquid water transport measurement. H Water flux measured through bare PCTE and graphene membrane (GM) under reverse osmosis (RO) based on effective membrane area (9.4% of total area). Also, see Supplementary Figs. 4 and 5. I Flux ratio of GM/PCTE for water vapor and liquid water. The GMs show significant water vapor flux (~57.3–62.9% of PCTE support) but very low liquid water flux (~1.2% of PCTE support under FO and ~0.0086% of PCTE support under RO). All error bars indicate one standard deviation. Source data are provided as Source Data file.