Publications de Wan-Chi Lee | EPFL Graph Search

Tuning Pore Size in Graphene in the Angstrom Regime for Highly Selective Ion-Ion Separation

Kumar Varoon Agrawal, Kuang-Jung Hsu, Heng-Yu Chi, Kangning Zhao, Luis Francisco Villalobos Vazquez de la Parra, Shaoxian Li, Wan-Chi Lee, Yuyang Zhang

Zero-dimensional pores spanning only a few angstroms in size in two-dimensional materials such as graphene are some of the most promising systems for designing ion-ion selective membranes. However, the key challenge in the field is that so far a crack-free ...

Amer Chemical Soc2024

Enhanced Water Evaporation from A-Scale Graphene Nanopores

Kumar Varoon Agrawal, Mounir Driss Mensi, Kuang-Jung Hsu, Luis Francisco Villalobos Vazquez de la Parra, Mostapha Dakhchoune, Shiqi Huang, Wan-Chi Lee

Enhancing the kinetics of liquid-vapor transition from nanoscale confinements is an attractive strategy for developing evaporation and separation applications. The ultimate limit of confinement for evaporation is an atom thick interface hosting angstrom-sc ...

AMER CHEMICAL SOC2022

Mass transport of water vapor and ions from Å-scale graphene nanopores

Wan-Chi Lee

Hydrodynamics at the nanoscale involves both fundamental study and application of fluid and mass transport phenomena in nanometer-sized confinements. Nanopores in single-layer graphene can be highly attractive for exploring the molecular transport of gas a ...

EPFL2022

Multipulsed Millisecond Ozone Gasification for Predictable Tuning of Nucleation and Nucleation-Decoupled Nanopore Expansion in Graphene for Carbon Capture

Kumar Varoon Agrawal, Mounir Driss Mensi, Kuang-Jung Hsu, Heng-Yu Chi, Luis Francisco Villalobos Vazquez de la Parra, Mostapha Dakhchoune, Shiqi Huang, Guangwei He, Wan-Chi Lee

Predictable and tunable etching of angstrom-scale nanopores in single-layer graphene (SLG) can allow one to realize high-performance gas separation even from similar-sized molecules. We advance toward this goal by developing two etching regimes for SLG whe ...

2021

Centimeter-scale gas-sieving nanoporous single-layer graphene membrane

Kumar Varoon Agrawal, Luc Sébastien Bondaz, Mostapha Dakhchoune, Shiqi Huang, Guangwei He, Wan-Chi Lee

High-permeance, molecular-sieving, nanoporous single-layer graphene (NSLG) membranes are highly promising for gas separation. However, the formation of cracks during the transfer of NSLG to a low-cost porous support is difficult to avoid. These cracks are ...

2020

Polybenzimidazole copolymer derived lacey carbon film for graphene transfer and contamination removal strategies for imaging graphene nanopores

Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra, Mostapha Dakhchoune, Shiqi Huang, Guangwei He, Wan-Chi Lee

The study of the nanometer-scale vacancy defects (nanopores) in graphene by transmission electron microscopy (TEM) is severely hindered by the presence of polymeric residues originating from the graphene-transfer-step to the TEM grid. The state-of-the-art ...

2020

Synergistic CO2-Sieving from Polymer with Intrinsic Microporosity Masking Nanoporous Single-Layer Graphene

Kumar Varoon Agrawal, Mounir Driss Mensi, Luis Francisco Villalobos Vazquez de la Parra, Shiqi Huang, Guangwei He, Jing Zhao, Wan-Chi Lee

High-flux nanoporous single-layer graphene membranes are highly promising for energy-efficient gas separation. Herein, in the context of carbon capture, a remarkable enhancement in the CO(2)selectivity is demonstrated by uniquely masking nanoporous single- ...

WILEY-V C H VERLAG GMBH2020