Publications by Guangwei He | EPFL Graph Search

Influence Of Span-Wise Coherence In A Cylinder Wake On The Acoustic Radiations

In the present work the influence of the spanwise coherence of the flow structures on the acoustic emission in the case of cylinder wakes is investigated. For this purpose, the correlation between pressure fluctuations in the far field and velocity fluctua ...

International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics2022

Sodium Superionic Conductors (NASICONs) as Cathode Materials for Sodium-Ion Batteries

Kangning Zhao, Guangwei He, Minmin Liu

Sodium-ion batteries (SIBs) have developed rapidly owing to the high natural abundance, wide distribution, and low cost of sodium. Among the various materials used in SIBs, sodium superion conductor (NASICON)-based electrode materials with remarkable struc ...

SPRINGERNATURE2021

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

Hybrid membranes for energy-efficient carbon capture

Kumar Varoon Agrawal, Guangwei He

Gas separation membrane comprising a porous support onto which is deposited a nanoporous single-layer graphene film with a CO2-philic polymer film having a thickness of 5-100 nm coated on top of graphene nanopores, acting as a CO2-selective film, wherein t ...

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

Two-dimensional nanochannel membranes for molecular and ionic separations

Guangwei He, Shaoyu Wang, Yifan Li, Zheyu Jiang

Two-dimensional (2D) nanosheets have emerged as promising functional materials owing to their atomic thickness and unique physical/chemical properties. By using 2D nanosheets as building blocks, diverse kinds of two-dimensional nanochannel membranes (2DNCM ...

Royal Society of Chemistry2020

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

High-permeance polymer-functionalized single-layer graphene membranes that surpass the postcombustion carbon capture target

Emad Oveisi, Kumar Varoon Agrawal, Mounir Driss Mensi, Luis Francisco Villalobos Vazquez de la Parra, Shiqi Huang, Guangwei He, Jing Zhao

Membrane-based postcombustion carbon capture can reduce the capture penalty in comparison to absorbent-based separation. To realize this, high-performance membranes are urgently needed with a CO2 permeance exceeding 1000 gas permeation units or GPU, and a ...

2019

Crystal Engineering of Metal-Organic Framework Thin Films for Gas Separations

Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra, Guangwei He, Deepu Joseph Babu

Metal organic frameworks or MOFs have witnessed a phenomenal rise owing to a highly tunable synthetic chemistry allowing flexibility in the selection of its constituents, namely metal nodes and linkers. Combined with their superior adsorption and diffusion ...

AMER CHEMICAL SOC2019