Differences in water and vapor transport through angstrom-scale pores in atomically thin membranes
Abstract
The transport of water through nanoscale capillaries/pores plays a prominent role in biology, ionic/molecular separations, water treatment and protective applications. However, the mechanisms of water and vapor transport through nanoscale confinements remain to be fully understood. Angstrom-scale pores (~2.8–6.6 Å) introduced into the atomically thin graphene lattice represent ideal model systems to probe water transport at the molecular-length scale with short pores (aspect ratio ~1–1.9) i.e., pore diameters approach the pore length (~3.4 Å) at the theoretical limit of material thickness. Here, we report on orders of magnitude differences (~80×) between transport of water vapor (~44.2–52.4 g m−2 day−1 Pa−1) and liquid water (0.6–2 g m−2 day−1 Pa−1) through nanopores (~2.8–6.6 Å in diameter) in monolayer graphene and rationalize this difference via a flow resistance model in which liquid water permeation occurs near the continuum regime whereas water vapor transport occurs in the free molecular flow regime. We demonstrate centimeter-scale atomically thin graphene membranes with up to an order of magnitude higher water vapor transport rate (~5.4–6.1 × 104 g m−2 day−1) than most commercially available ultra-breathable protective materials while effectively blocking even sub-nanometer (>0.66 nm) model ions/molecules.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 07, 2022
- Source ID
- 10.1038/s41467-022-34172-1
Entities
People
- An-Ping Li
- Francesco Fornasiero
- Juan Carlos Idrobo
- Melinda L Jue
- Michael S H Boutilier
- Peifu Cheng
- Piran Ravichandran Kidambi
- Wonhee Ko
Organizations
- American Chemical Society Petroleum Research Fund
- Defense Threat Reduction Agency
- Oak Ridge National Laboratory