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Kumar Varoon Agrawal

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Related publications (71)

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

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

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

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

Selective Photonic Gasification of Strained Oxygen Clusters on Graphene for Tuning Pore Size in the Å Regime

Oleg Yazyev, Kumar Varoon Agrawal, Shaoxian Li, Kristians Cernevics, Luc Sébastien Bondaz, Jian Hao

Controlling the size of single-digit pores, such as those in graphene, with an & Aring; resolution has been challenging due to the limited understanding of pore evolution at the atomic scale. The controlled oxidation of graphene has led to & Aring;-scale p ...

AMER CHEMICAL SOC2023

Electrophoretic Nuclei Assembly for Crystallization of High Performance Membranes on Unmodified Supports

Kumar Varoon Agrawal, Shiqi Huang, Mostapha Dakhchoune, Guangwei He, Jing Zhao

Metal-organic frameworks (MOFs) films have recently emerged as highly permselective membranes yielding orders of magnitude higher gas permeance than that from the conventional membranes. However, synthesis of highly-intergrown, ultrathin MOF films on porou ...

2018

Dynamic Behavior of Spatially Confined Sn Clusters and Its Application in Highly Efficient Sodium Storage with High Initial Coulombic Efficiency

Lei Zhang, Kumar Varoon Agrawal, Kangning Zhao

Advanced battery electrodes require a cautious design of microscale particles with built-in nanoscale features to exploit the advantages of both micro- and nano-particles relative to their performance attributes. Herein, the dynamic behavior of nanosized S ...

Wiley-V C H Verlag Gmbh2024

In Situ Nucleation-Decoupled and Site-Specific Incorporation of angstrom-Scale Pores in Graphene Via Epoxidation

Nicola Marzari, Kumar Varoon Agrawal, Victor Carle Adrien Boureau, Luis Francisco Villalobos Vazquez de la Parra, Shiqi Huang, Heng-Yu Chi, Shaoxian Li, Kuang-Jung Hsu, Luc Sébastien Bondaz, Mohammad Tohidivahdat

Generating pores in graphene by decoupled nucleation and expansion is desired to achieve a fine control over the porosity, and is desired to advance several applications. Herein, epoxidation is introduced, which is the formation of nanosized epoxy clusters ...

Wiley-V C H Verlag Gmbh2022

Electrophoretic Crystallization of Ultrathin High-performance Metal-organic Framework Membranes

Kumar Varoon Agrawal, Guangwei He, Deepu Joseph Babu

We report the synthesis of thin, highly intergrown, polycrystalline metal-organic framework (MOF) membranes on a wide range of unmodified porous and non-porous supports (polymer, ceramic, metal, carbon, and graphene). We developed a novel crystallization t ...

JOURNAL OF VISUALIZED EXPERIMENTS2018

Advancing Molecular Sieving via Å-Scale Pore Tuning in Bottom-Up Graphene Synthesis

Kumar Varoon Agrawal, Mounir Driss Mensi, Kangning Zhao, Heng-Yu Chi, Cédric Karel J Van Goethem, Yueqing Shen

Porous graphene films are attractive as a gas separation membrane given that the selective layer can be just one atom thick, allowing high-flux separation. A favorable aspect of porous graphene is that the pore size, essentially gaps created by lattice def ...

Amer Chemical Soc2024

Synthesis of high-performance polycrystalline metal-organic framework membranes at room temperature in a few minutes

Kumar Varoon Agrawal, Heng-Yu Chi, Qi Liu, Deepu Joseph Babu, Jian Hao

The development of a rapid and reproducible crystallization route for the synthesis of polycrystalline metal-organic framework (MOF) films is attractive for the scalable production of nanoporous membranes on porous supports. Prior crystallization studies h ...

Royal Society of Chemistry2020

Graphene membranes with pyridinic nitrogen at pore edges for high-performance CO2 capture

Andreas Züttel, Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra, Shiqi Huang, Liping Zhong, Heng-Yu Chi, Shaoxian Li, Kuang-Jung Hsu, Marina Micari, Shuqing Song, Xuekui Duan

Membranes based on a porous two-dimensional selective layer offer the potential to achieve exceptional performance to improve energy efficiency and reduce the cost for carbon capture. So far, separation from two-dimensional pores has exploited differences ...

Nature Portfolio2024

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, Mojtaba Chevalier, 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

Bottom-up synthesis of graphene films hosting atom-thick molecular-sieving apertures

Emad Oveisi, Kumar Varoon Agrawal, Kangning Zhao, Victor Carle Adrien Boureau, Luis Francisco Villalobos Vazquez de la Parra, Shiqi Huang, Mostapha Dakhchoune, Shaoxian Li, Kuang-Jung Hsu, Cédric Karel J Van Goethem, Yueqing Shen, Mina Moradi

Incorporation of a high density of molecular-sieving nanopores in the graphene lattice by the bottom-up synthesis is highly attractive for high-performance membranes. Herein, we achieve this by a controlled synthesis of nanocrystalline graphene where incom ...

National Academy of Sciences2021

Mechanistic Insights on Functionalization of Graphene with Ozone

Nicola Marzari, Kumar Varoon Agrawal, Shiqi Huang, Shaoxian Li, Kuang-Jung Hsu, Luc Sébastien Bondaz, Nicéphore Arthur François Bonnet

The exposure of graphene to O-3 results in functionalization of its lattice with epoxy, even at room temperature. This reaction is of fundamental interest for precise lattice patterning, however, is not well understood. Herein, using van der Waals density ...

Amer Chemical Soc2023

Towards ultrathin metal-organic frameworks membranes for high-performance separation

Kumar Varoon Agrawal, Heng-Yu Chi, Qi Liu, Shuqing Song, Ranadip Goswami

Research on metal-organic frameworks (MOFs) based membranes has gained a lot of attention in the last decade thanks to the unique and highly versatile chemistry of MOFs, which allows one to synthesize a variety of structural dimensions, topologies, pore si ...

Aip Publishing2023

Unraveling the Oxidation of a Graphitic Lattice: Structure Determination of Oxygen Clusters

Nicola Marzari, Kumar Varoon Agrawal, Shiqi Huang, Shaoxian Li

Unraveling the oxidation of graphitic lattice is of great interest for atomic-scale lattice manipulation. Herein, we build epoxy cluster, atom by atom, using Van der Waals' density-functional theory aided by Clar's aromatic it-sextet rule. We predict the f ...

Amer Physical Soc2023

Gas-sieving zeolitic membranes fabricated by condensation of precursor nanosheets

Michele Ceriotti, Kumar Varoon Agrawal, Pascal Alexander Schouwink, Luis Francisco Villalobos Vazquez de la Parra, Mostapha Dakhchoune, Claudia Esther Avalos, Mojtaba Chevalier, Rocio Semino Barbaresi

The synthesis of molecular-sieving zeolitic membranes by the assembly of building blocks, avoiding the hydrothermal treatment, is highly desired to improve reproducibility and scalability. Here we report exfoliation of the sodalite precursor RUB-15 into cr ...

2020

In depth analysis of heterogeneous catalysts for the chemoenzymatic dynamic kinetic resolution of beta-amino esters

Kumar Varoon Agrawal, Cédric Karel J Van Goethem

The chemoenzymatic dynamic kinetic resolution of beta-amino esters is established after detailed evaluation of metal-based heterogeneous catalysts for racemization and enzyme catalysts for kinetic resolution. Several heterogeneous palladium catalysts prove ...

ROYAL SOC CHEMISTRY2022

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, Shiqi Huang, Mostapha Dakhchoune, 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

Influence of micro-patterned support properties and interfacial polymerization conditions on performance of patterned thin-film composite membranes

Kumar Varoon Agrawal, Cédric Karel J Van Goethem

Patterned membranes prepared via spray-modified non -solvent induced phase separation (s-NIPS) have successfully shown enhanced fluxes and better fouling control, thanks to the increased surface area and high fluid shear at the membrane/feed interface. The ...

Elsevier2024

Angstrom‐Scale Triangular Pore in Single‐Layer Hexagonal Boron Nitride Membrane for Molecular Sieving

Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra, Heng-Yu Chi

Single‐layer crystalline films are ideal separation membrane materials because their atomic thickness could yield the highest possible molecular flux once nanopores are generated. However, the development of single‐layer membranes with well‐defined pore st ...

Wiley2025