Publications de Luis Francisco Villalobos Vazquez de la Parra

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

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

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

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

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

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

Hydrogen-sieving zeolitic films by coating zeolite nanosheets on porous polymeric support

Kumar Varoon Agrawal, Mostapha Dakhchoune, Luis Francisco Villalobos Vazquez de la Parra, Xuekui Duan

The synthesis of high-performance gas-sieving zeolitic film is challenging because it involves seeded secondary growth which is complex and difficult to reproduce. Additionally, expensive asymmetric inorganic porous supports are often needed for calcinatio ...

ELSEVIER2023

Unit-cell-thick zeolitic imidazolate framework films for membrane application

Yu Han, Deepu Joseph Babu, Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra, Heng-Yu Chi, Shaoxian Li, Qi Liu, Jian Hao, Shuqing Song

Zeolitic imidazolate frameworks (ZIFs) are a subset of metal-organic frameworks with more than 200 characterized crystalline and amorphous networks made of divalent transition metal centres (for example, Zn2+ and Co2+) linked by imidazolate linkers. ZIF th ...

NATURE PORTFOLIO2023

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

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

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

Enhanced Water Evaporation from A-Scale Graphene Nanopores

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

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

Unblocking Ion-occluded Pore Channels in Poly(triazine imide) Framework for Proton Conduction

Kumar Varoon Agrawal, Pascal Alexander Schouwink, Luis Francisco Villalobos Vazquez de la Parra, Heng-Yu Chi, Qi Liu, Kangning Zhao, Laura Piveteau

Poly(triazine imide) or PTI is an ordered graphitic carbon nitride hosting angstrom-scale pores attractive for selective molecular transport. AA'-stacked PTI layers are synthesized by ionothermal route during which ions occupy the framework and occlude the ...

Wiley-VCH Verlag GmbH2022

Gas Separation Membranes with Atom-Thick Nanopores: The Potential of Nanoporous Single-Layer Graphene

Deepu Joseph Babu, Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra, Kuang-Jung Hsu, Cédric Karel J Van Goethem

Gas separation is one of the most important industrial processes and is poised to take a larger role in the transition to renewable energy, e.g., carbon capture and hydrogen purification. Conventional gas separation processes involving cryogenic distillati ...

AMER CHEMICAL SOC2022

Demonstrating and Unraveling a Controlled Nanometer-Scale Expansion of the Vacancy Defects in Graphene by CO2

Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra, Kuang-Jung Hsu

A controlled manipulation of graphene edges and vacancies is desired for molecular separation, sensing and electronics applications. Unfortunately, available etching methods always lead to vacancy nucleation making it challenging to control etching. Herein ...

Wiley-VCH Verlag GmbH2022

Rapid Gas Transport from Block-Copolymer Templated Nanoporous Carbon Films

Kumar Varoon Agrawal, Mostapha Dakhchoune, Jing Zhao, Luis Francisco Villalobos Vazquez de la Parra, Kuang-Jung Hsu, Marina Micari, Xuekui Duan

Porous carbon films, attributed to their superior thermal and chemical robustness, are attractive for a number of applications. In the context of molecular separation, a major focus has been on films where the effective pore diameter is lower than 1 nm, e. ...

AMER CHEMICAL SOC2021

Systematic design of millisecond gasification reactor for the incorporation of gas-sieving nanopores in single-layer graphene

Kumar Varoon Agrawal, Shiqi Huang, Luis Francisco Villalobos Vazquez de la Parra, Shaoxian Li, Kuang-Jung Hsu

Etching an ensemble of vacancy defects (nanopores) in single-layer graphene (SLG) to obtain a high density of nanopores with an effective size that enables high-performance gas sieving is challenging. This is because nanopore nucleation and expansion are u ...

2021

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

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

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

Method of preparation of porous polymeric support layer and uses thereof

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

The invention relates to methods for the preparation of polymer supported graphene membrane by non-solvent induced phase separation and resulting products thereof, in particular useful for the preparation of gas separation membranes, in particular for He o ...

2021

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

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

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

Millisecond lattice gasification for high-density CO2- and O2-sieving nanopores in single-layer graphene

Mounir Driss Mensi, Emad Oveisi, Deepu Joseph Babu, Kumar Varoon Agrawal, Shiqi Huang, Mostapha Dakhchoune, Luis Francisco Villalobos Vazquez de la Parra, Shaoxian Li, Marina Micari

Etching single-layer graphene to incorporate a high pore density with sub-angstrom precision in molecular differentiation is critical to realize the promising high-flux separation of similar-sized gas molecules, e.g., CO2 from N2. However, rapid etching ki ...

2021

Crystalline poly(triazine imide) membranes and uses thereof

Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra

The invention relates to methods for the preparation of highly crystalline poly(triazine imide) in the form of platelets, atom-thick layers or membranes thereof and resulting products thereof, in particular useful for the preparation of gas separation memb ...

2021

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

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

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

Efficient Kr/Xe separation from triangular g-C(3)N(4)nanopores, a simulation study

Nicola Marzari, Nicola Colonna, Kumar Varoon Agrawal, Davide Campi, Luis Francisco Villalobos Vazquez de la Parra

Poly(triazine imide) or PTI is a promising material for molecular sieving membranes, thanks to its atom-thick ordered lattice with an extremely high density (1.6 x 10(14)pores per cm(2)) of triangular-shaped nanopores of similar to 0.34 nm diameter. Here, ...

Royal Society of Chemistry2020