Erik Neyts professor

Research Erik Neyts

Research team

Expertise

We employ computational techniques (molecular dynamics, DFT, enhanced sampling) in astrochemistry and to study the chemistry of nanomaterials. We have expertise in particular in gas-ice interactions and the chemistry of the interstellar medium, and on the chemistry of carbon nanotubes and graphene, Si-nanomaterials, nanoclusters and related nanomaterials.

Chemistry 2.0: Grignard surface modification unraveled 01/01/2023 - 31/12/2026

Abstract

Hybrid organic inorganic metal oxides combine the structural and physicochemical properties of inorganic materials with the versatility and specificity of organic molecules, creating exciting materials for a wide variety of applications in e.g. separation technology, catalysis, electronics and sensing. UAntwerp and VITO invented and patented a Grignard-based surface modification method anchoring the organic group directly to the metal oxide surface, which creates a unique synergic interaction between the metal oxide and the functional organic group, pioneering a new class of materials. While the applicability of this new method was well demonstrated in membrane filtration, the exact mechanism is still lacking. To allow broader and more specific steering of the materials properties this project is therefore aimed directly at 1) elucidating the mechanism of the surface modification; and 2) identifying the role of the metal oxide support. In this project, we will use a combination of beyond-state-of-the-art computational techniques, experimental surface modification and advanced characterization to meet these goals.

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  • Research Project

Unraveling the surface chemistry of icy dust particles in the interstellar medium. 01/10/2022 - 30/09/2026

Abstract

More than 200 different molecules have so far been identified in the interstellar space, ranging from H2 to complex organic molecules such as ethanolamine. In the extreme conditions of the interstellar space, gas phase reactions alone cannot explain their occurrence, and ice-covered dust particles are believed to play a crucial rol in their formation. At present, however, very little is known about the precise mechanisms of the interaction between the interstellar gas and the icy dust particles, and how these ice surfaces could "catalyse" the required chemical reactions. In this project, we will employ in-house developed state-of-the-art computational techniques to address these interactions. We will construct representative ice structures, calculate binding energies of astrochemically relevant molecules, and calculate free energy profiles and rate coefficients for a paradigmatic set of reactions. In collaboration with leading experts in the field, we will also assess the importance of these interactions on the resulting gas phase abundances, to enable accurate benchmarking against experimental data. This research carries the potential to change our perspective on how interstellar icy dust particles determine the chemical evolution of our universe.

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  • Research Project

InSusChem - Consortium for Integrated Sustainable Chemistry Antwerp. 15/10/2020 - 31/12/2026

Abstract

This IOF consortium connects chemists, engineers, economic and environmental oriented researchers in an integrated team to maximize impact in key enabling sustainable chemical technologies, materials and reactors that are able to play a crucial role in a sustainable chemistry and economic transition to a circular, resource efficient and carbon neutral economy (part of the 2030 and 2050 goals in which Europe aims to lead). Innovative materials, renewable chemical feedstocks, new/alternative reactors, technologies and production methods are essential and central elements to achieve this goal. Due to their mutual interplay, a multidisciplinary, concerted effort is crucial to be successful. Furthermore, early on prediction and identification of strengths, opportunities, weaknesses and threats in life cycles, techno-economics and sustainability are key to allow sustainability by design and create effective knowledge-based decision-making and focus. The consortium focuses on sustainable chemical production through efficient and alternative energy use connected to circularity, new chemical pathways, technologies, reactors and materials, that allow the use of alternative feedstock and energy supply. These core technical aspects are supported by expertise in simulation, techno-economic and environmental impact assessment and uncertainty identification to accelerate technological development via knowledge-based design and early stage identified key research, needed for accelerated growth and maximum impact on sustainability. To achieve these goals, the consortium members are grouped in 4 interconnected valorisation programs focusing on key performance elements that thrive the chemical industry and technology: 1) renewable building blocks; 2) sustainable materials and materials for sustainable processes; 3) sustainable processes, efficiently using alternative renewable energy sources and/or circular chemical building blocks; 4) innovative reactors for sustainable processes. In addition, cross-cutting integrated enablers are present, providing expertise and essential support to the 4 valorisation programs through simulation, techno-economic and environmental impact assessment and uncertainty analysis.

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Bringing nanoscience from the lab to society (NANOLAB). 01/01/2020 - 31/12/2025

Abstract

Nanomaterials play a key role in modern technology and society, because of their unique physical and chemical characteristics. The synthesis of nanomaterials is maturing but surprisingly little is known about the exact roles that different experimental parameters have in tuning their final properties. It is hereby of crucial importance to understand the connection between these properties and the (three-dimensional) structure or composition of nanomaterials. The proposed consortium will focus on the design and use of nanomaterials in fields as diverse as plasmonics, electrosensing, nanomagnetism and in applications such as art conservation, environment and sustainable energy. In all of these studies, the consortium will integrate (3D) quantitative transmission electron microscopy and X-ray spectroscopy with density functional calculations of the structural stability and optoelectronic properties as well as with accelerated molecular dynamics for chemical reactivity. The major challenge will be to link the different time and length scales of the complementary techniques in order to arrive at a complete understanding of the structure-functionality correlation. Through such knowledge, the design of nanostructures with desired functionalities and the incorporation of such structures in actual applications, such as e.g. highly selective sensing and air purification will become feasible. In addition, the techno-economic and environmental performance will be assessed to support the further development of those applications. Since the ultimate aim of this interdisciplinary consortium is to contribute to the societal impact of nanotechnology, the NanoLab will go beyond the study of simplified test materials and will focus on nanostructures for real-life, cost-effective and environmentally-friendly applications.

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Computational modeling of materials: from atomistic properties to new functionalities. 01/01/2019 - 31/12/2028

Abstract

In this WOG, the overarching goal is to employ existing and develop new computational methodologies at the atomistic and molecular scale to model and simulate fundamental material properties to explore and understand novel material functionalities.

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Computational design of layered graphene oxide (GO) membranes. 01/10/2022 - 30/09/2023

Abstract

In recent years layered graphene oxide (GO) membranes showed immense potential to overcome the limitations of conventional membrane materials with superior water flux and intriguing physical/chemical properties. However, its practical applications is still questionable mainly due to its undesirable swelling in water. To address this issue, meticulous understanding on the effect of the oxygen containing functional groups on the performance of layered GO membranes is of utmost importance, which is not available in the existing literature. Intercalation of cations could enhance aqueous stability of layered GO membranes. Inspired by this, I propose that also the generation of hydronium ions inside the interlayer gallery would impart aqueous stability of GO membranes. Hydronium ions could be generated by the dissociation of water molecules using an external electric field. Additionally, by constructing a membrane from a heterostructure of GO and reduced GO nanosheets, a balance between water flux and aqueous stability could be obtained. This could also lead to a Janus membrane with different wettabilities on the same membrane structure which could be effective in the separation of various oil-water mixtures. In this proposal, we will investigate all these aspects using atomistic simulations with extensive collaborations with different experimental and theoretical groups.

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Computational exploration of new pathways in gas conversion on novel nanocatalysts. 01/11/2020 - 31/10/2024

Abstract

Conversion of greenhouse gases (especially CH4 and CO2) to valueadded chemicals is of great importance in the context of climate change as well as chemical industry. The traditional conversion of CH4 and CO2 often requires high temperature and pressure using expensive and polluting metal surfaces. Finding a clean catalyst with high selectivity to directly synthesize fuels from CH4 and CO2 gases at room temperature would thus be very beneficial from chemical, environmental and economic perspective. Recently, single individual metal atoms anchored to graphene-based materials are explored as novel materials not only because they minimize material usage, but also because they may surpass conventional catalysts in terms of the high specific activity. In this project, I will employ DFT calculations to explore a new class of nanocatalysts by tailoring their surfaces. The detailed mechanisms of direct chemical and electrochemical conversion of CH4 and CO2 gases to fuels on these tailored nanocatalysts will be studied. I will explore how these mechanisms control the reaction rates by developing a specific kinetic model for each chemical (electrochemical) reaction. To obtain a more global understanding of optimized conversion and energy efficiencies, the computational results will be compared to both experimental literature data and collaboration results.

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Understanding the chemistry at the plasma–catalyst interface through atomistic modeling. 01/10/2019 - 30/09/2022

Abstract

Recently, plasma catalysis is gaining interest as an alternative to traditional thermo-catalytic techniques. Due to the non-equilibrium physical state of the plasma, with much energy stored in a limited number of degrees of freedom, specific chemical processes can be selectively stimulated or inhibited, and the location of the chemical equilibrium can be shifted. Various physical effects at the plasma–catalyst interface—such as vibrationally excited molecules, excess charges, and electric fields—are nonexistent under purely thermal conditions, and can dramatically change the chemistry at the catalyst surface. However, very little is known about this new frontier in surface science due to lack of dedicated experiments or detailed models. In this project, I will explore the unique physicochemical phenomena that arise at the plasma–catalyst interface. I will develop an integrated atomistic modeling approach based on advanced first principles simulation techniques, unravel the fundamental mechanisms of plasma-induced processes at the catalyst, and reveal how new chemical regimes can be accessed through several types of selective plasma–catalyst coupling. Indeed, the unconventional chemistry at the plasma–catalyst interface constitutes a new, unexplored discipline of catalysis. The fundamental insights from this project would hence greatly improve our understanding of the physical chemistry of surfaces and can aid the development of new efficient gas conversion technologies.

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A structured methodology for NADES selection and formulation for enzymatic reactions. 01/10/2019 - 30/09/2022

Abstract

Natural deep eutectic solvents (NADES) show great promise as media for enzymatic reactions in sectors where (bio)compatibility with natural or medical products is a must. Whereas in theory they can be tailored to the envisioned reaction, ensuring optimized yields, to date the knowledge is predominantly empirical, with some mechanistic reports giving a fragmented view at best. Therefore, even merely explaining experimental observations is not straightforward, let alone making predictions. This doctoral study aims at building a structured, holistic understanding of the effect of NADES media on enzymatic reactions, whereby effects on solubility, solvation, viscosity, inhibition and denaturation will be distinguished. The solubility, solvation energy and viscosity will be predicted by first principles and molecular dynamics calculations, serving as input for a group contribution model using machine learning. Experiments will train and validate the model, and learnings from observed reaction kinetics will be further benchmarked against molecular dynamics calculations of enzyme structures and interactions in NADES. Structural changes of the enzyme will be demonstrated using Raman optical activity spectroscopy. The combination of these methods ensures fundamental knowledge acquisition, while the group contribution model is part of a structured methodology. The findings of this project are transferable to other uses of NADES.

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Atomic thin membranes for water and ion transport. 01/01/2019 - 31/12/2022

Abstract

Membranes are used for different separation processes with applications in areas as diverse as water desalination, gas separation, energy technologies, microfluidics and medicine. Due to its atomic thickness and its exceptional mechanical properties, graphene and related materials have opened up new possibilities in membrane technologies. Such membranes will be investigated for water and hydrogen transport, ion sieving and hydrogen isotope separation. Fundamental insights into mass transport at the nanoscale will be obtained through theoretical and computational modelling with intensive collaboration with experimentalists for validation.

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Multiscale numerical simulations of magnetron sputter deposition. 01/10/2018 - 31/03/2019

Abstract

Numerical simulations allow to gain insight in basic processes underlying the complexity of real-life experiments. In this project, multiscale simulations are carried out to investigate the formation of thin catalytic Pt layers in a magnetron sputter deposition setup. Fluid simulations are employed to study the macroscale sputter deposition process. This provides the input needed for the subsequent microscale / atomic scale simulations. In these atomic scale simulations, novel methodologies – in particular collective variable-driven hyperdynamics – are used to access time scales well beyond the reach of standard molecular dynamics techniques. From these simulations, we hope to reach a better understanding of how the morphology and structure of thin Pt films is formed and could be steered.

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Plasma catalysis at the nanoscale: A generic Monte Carlo model for the investigation of the diffusion and the chemical reactions of plasma species at porous catalysts. 01/10/2017 - 30/09/2020

Abstract

In this project we will develop a generic model to simulate the diffusion of plasma species in and out of the pores of a catalyst and the catalytic reactions at the pore surface. In this way we will try to gather insight in the underlying processes in plasma catalysis in general and in the plasma catalytic conversion of CO2 and H2 to methanol specifically. In this project, we will focus on the conversion on a Cu-catalyst. Using quantum chemical calculations we will determine the properties of adsorption of the most important plasma species and the different reaction mechanisms and reaction rates at the surface. In parallel we will develop a Monte Carlo model to examine the diffusion of plasma species inside catalyst pores, as well as their surface reactions, for which we will make use of the results provided by the quantum chemical calculations. This model will allow us to investigate the role of plasma species in the methanol synthesis, the influence of the pore size and the pore shape on the total yield, which reaction products and side products are formed and whether these products can diffuse out of the pores to make room for new reactants. The results of this study will provide the necessary information for understanding plasma catalytic processes at a fundamental level and are essential to further optimise these promising processes.

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Long time scale dynamics of carbon nanostructure growth 01/10/2017 - 30/09/2020

Abstract

The spectacular properties of carbon nanotubes and graphene have generated worldwide commercial interest in these materials. However, realizing their full application in nanotechnology requires fundamental knowledge which is currently lacking. In particular, their properties strongly depend on their exact structure. How to control the structure during the growth is still elusive. Plasma-enhanced chemical vapor deposition (PECVD) has been envisaged as a means towards structure control due its ability to narrow the resulting chirality distribution with respect to thermal CVD and other growth techniques. In PECVD, however, several synergistic effects, such as the interplay between growth species, electric field and catalyst have not been investigated yet. Also, simultaneous etching complicates the PECVD-based growth process of CNTs and graphene considerably. Moreover, also the nucleation mechanism of multi-walled CNTs in both CVD setups is still unclear. In this project, we aim to study both CVD-based growth processes in the picosecond-to-seconds regime, by making use of a novel, in-house developed simulation method, called collective variable-driven hyperdynamics. In particular, we will analyze the intermediate nanoscale mechanisms in detail, focussing explicitly on the synergistic effects, which are extremely difficult to observe directly by experiments. We envisage that this research will lead to the understanding that is required to eventually control the carbon structure.

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Atomic scale simulations for a better understanding of cancer treatment by plasmas. 01/10/2017 - 30/09/2019

Abstract

Atmospheric pressure plasmas are gaining increasing interest for biomedical applications, like sterilization, wound treatment, dental treatment, blood coagulation, and especially cancer treatment. In the latter case, plasmas have demonstrated to give very promising results, both in vitro and in vivo, and are able to attack a wide range of cancer cell lines without damaging healthy cells. However, the underlying mechanisms are not yet fully understood. I will therefore perform atomic scale simulations to study the interaction mechanisms of reactive oxygen and nitrogen species (ROS, RNS) formed in the plasma with biomolecules, present in eukaryotic cells, which play a role in cancer (treatment). More specifically, I will apply classical molecular dynamics and density functional based tight binding simulations, and I will study three types of biomolecules, which play a crucial role in cancer (treatment): (1) a phospholipid bilayer (PLB) as model system for the cell membrane, (2) a part of a DNA string and (3) peptides, as a model system for proteins. I will investigate how the ROS and RNS interact with these biomolecules, which reaction products are formed, and how this can lead to apoptosis (cell death). This research will contribute to a better understanding of the role of plasmas in cancer treatment.

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Computational design of improved catalysts for plasma catalytic dry reforming of methane. 01/10/2016 - 30/09/2020

Abstract

This projects aims at the computational screening and design of bimetallic nanocatalysts for plasma catalytic dry reforming of methane. This reaction is highly interesting from both from an ecological as well as an economical point of view, since the reactants (CH4 and CO2) are strong greenhouse gases, while the product (syngas, i.e., a mixture of CO and H2) is the raw material for a wide variety of chemicals, including synthetic fuels. Based on extensive density functional theory calculations, a large number of potentially interesting catalyst candidates will be screened on 3 criteria: 1) adsorption and desorption of relevant plasma species from the catalyst surface (thermodynamic screening); 2) energy barriers of elementary reactions at the catalyst surface (1st kinetic screening); and 3) reaction rate coefficients of elementary reactions at the catalyst surface (2nd kinetic screening). In each of these steps, less suitable catalyst candidates are excluded in order to narrow down the list of remaining potentially interesting catalyst candidates. This will eventually lead to a list of catalysts which are theoretically suitable for syngas formation starting from plasma species derived from CH4 and CO2.

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Multi-timescale atomistic modeling of plasma catalysis and plasmabased growth of carbon nanostructures. 01/10/2016 - 30/09/2018

Abstract

In this project I will develop a novel atomic scale simulation tool to unravel the fundamental mechanisms underpinning complex plasma-based processes. Specifically, I will concentrate on plasma catalysis, which is envisaged to provide an energy efficient route for greenhouse gas conversion into value-added chemicals, and plasma-based growth of carbon nanostructures, which holds promise to offer control on structure and composition, unattainable by thermal methods.

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Plasma catalysis at the nanoscale: Model development for diffusion of plasma particles in pores and study of the catalytic behaviour at the pore surface. 01/10/2016 - 30/09/2017

Abstract

In this project we will develop a generic model to simulate the diffusion of plasma species in and out of catalyst pores and the catalytic reactions at the pore surface. We will try to gather insight in the underlying processes of plasma catalysis in general and of the plasma catalytic conversion of CO2 and H2 to methanol specifically. We will focus on the conversion on a Cu-catalyst. Using quantum chemical calculations we will determine the properties of adsorption of the most important plasma species and the different reaction mechanisms and reaction rates. In parallel we will develop a Monte Carlo model to examine the diffusion of plasma species inside catalyst pores, as well as their surface reactions, for which I will apply the results arising from the quantum chemical calculations. We will determine the minimum pore diameter needed for the plasma species to be able to penetrate the catalyst pores and undergo chemical reactions, which reaction products and side products are formed and whether these products can diffuse out of the pores to make room for new reactants. The results of this study will provide the necessary information to understand plasma catalytic processes at a fundamental level and are essential to further optimize these promising processes.

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Multi-scale modeling of plasma catalysis/ 01/01/2016 - 31/12/2019

Abstract

This project aims to obtain more insight in the fundamental processes of plasma catalysis by multi-scale modeling. The plasma chemistry in a CH4/CO2 mixture will be described by a 0D model, and inserted in a 3D macro-scale model of a packed bed reactor. The plasma behavior near/in catalyst pores will be modelled on a micro-scale. Finally, the plasma-catalyst interactions on the atomic scale will be modeled by classical MD and DFT simulations.

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Computational catalyst screening for chirality-controlled growth of carbon nanotubes 01/01/2016 - 31/12/2019

Abstract

Carbon nanotubes find many application in diverse areas, such as fibers in composite materials, as sensors, actuators, transistor components, etc. The electronic and optical properties of CNTs, however, are strongly dependent on the CNT chirality, i.e., on the exact CNT structure. This chirality is determined during the growth process, and hence it is very important to be able to control the growth process. The first goal of this project is therefore to unravel the CNT growth mechanisms and to understand the influence of the catalyst on the resulting chirality, by means of density functional theory (DFT) calculations. Experiments have shown that bi- and multi-metallic catalysts show great potential for chirality-specific growth. A generic screening procedure, capable to select possible suitable catalyst materials fast and cheap, would be highly beneficial. The development of such a procedure is therefore the second goal of this project. The screening procedure will consist of 1 thermodynamic and 2 kinetic screenings. DFT calculations will be performed for various bimetallic catalysts. CNTs with various charities will be modeled, as well as a number of CNTs with defects. The combination of these screenings will lead to two final goals: a correct reproduction of chirality-controlled growth for a known class of bimetallic catalysts, and the prediction of possible chirality-controlled growth for as yet unknown combinations of catalysts, which can be verified experimentally in collaboration with Tohoku University (Japan).

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Formation of hydroxyapatite coatings with tailored properties using radio-frequency mognetron sputtering through combined experiments and simulations. 01/12/2015 - 31/05/2016

Abstract

Ceramics based on hydroxyapatite is one of the most widely used materials for bone replacement, because of its high biocompatibility. Nowadays, HA-based coatings are commonly used in medicine to enhance the osteoinductive properties of metallic implants. In contrast to the relatively large number of experimental data, which in some cases can provide a global insight into the growth mechanism and structure of thin firms, there are currently very few atomistic studies using computer modeling to study the evolution of the coating structure and composition during thin film growth at the atomic level. Simulation of the HA coating growth process with desired properties deposited by RF-magnetron sputtering allows to gain insight in preparing the coating with tailored properties. Through detailed comparison between experimental and theoretical results, this project aims to further develop the scientific research, the mathematical model will help us to explicitly determine the physical and chemical phenomena that occur during the reactive deposition of the thin film, and will eventually allow to increase the resource efficiency of the industrial ion-plasma system.

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Atomic scale modeling for plasma cancer treatment. 01/10/2015 - 30/09/2018

Abstract

The application of cold atmospheric plasmas (CAPs) in medicine is increasingly gaining attention in recent years and is becoming one of the main topical areas of plasma research. The effective use of CAPs, however, is strongly dependent on the understanding of the underlying processes, both in the plasma and more importantly in the contact region of plasma with the living cells. In order to accurately control the processes occurring at the surface of the bio-organisms, there is a strong need to deeply investigate the exact interaction mechanisms of the plasma-generated species with biochemically relevant structures. This still remains a big challenge. Computer simulations may provide fundamental atomic level insight into the processes occurring at the surface of living cells, which is difficult or even impossible to obtain through experiments. Thus, in this project, I envisage to use atomistic simulations to investigate the interaction mechanisms of reactive plasma species with biomolecules, which play a crucial role in cancer (treatment), to better understand the underlying mechanisms of plasma oncology. For this purpose I will use reactive molecular dynamics as well as density functional based tight binding simulations. Specifically, I aim to determine whether plasma-induced reactive species can react and modify the biomolecular structure (or conformation) and change its function, which can eventually lead to cancer cell death (i.e., apoptosis).

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Computer modeling of plasmas and their surface processes, with experimental validation, for a better understanding of cryogenic etching. 01/10/2015 - 31/08/2018

Abstract

Plasmas are widely used in the microelectronics industry for the fabrication of computer chips, during plasma etching and deposition of materials. Following Moore's law, much effort is put into continuously decreasing electronic feature dimensions. Indeed, typical feature sizes decreased from 10 μm in 1971 to 14 nm in 2014. The gradual shrinking of features thus entails a continuous improvement of the plasma processes. To go beyond 14 nm features, it is crucial to limit plasma induced damage during processing. Recently, one such novel process to limit plasma damage is cryogenic etching of low-k material with SF6/O2/SiF4 and CxFy plasmas. In this project, I wish to obtain a fundamental understanding of the plasma behavior and its interaction with the surface, for these gas mixtures, to improve cryogenic plasma etching. For this purpose, I will apply numerical models to describe (i) the plasma behavior for SF6/O2/SiF4 and CxFy gas mixtures, and (ii) the surface interactions of the plasma species with the substrate. The plasma behavior will be simulated by a hybrid Monte Carlo - fluid model for addressing the various plasma species (electrons, ions, neutrals and excited species). The interaction of the plasma species with the substrate surface will be described by additional Monte Carlo and molecular dynamics (MD) simulations, allowing a detailed insight in the microscopic trench etching process. Furthermore, I plan to validate the models by means of cryogenic etch experiments.

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Atomic scale simulations for a better understanding of cancer treatment by plasmas. 01/10/2015 - 30/09/2017

Abstract

Atmospheric pressure plasmas are gaining increasing interest for biomedical applications, like sterilization, wound treatment, dental treatment, blood coagulation, and especially cancer treatment. In the latter case, plasmas have demonstrated to give very promising results, both in vitro and in vivo, and are able to attack a wide range of cancer cell lines without damaging healthy cells. However, the underlying mechanisms are not yet fully understood. I will therefore perform atomic scale simulations to study the interaction mechanisms of reactive oxygen and nitrogen species (ROS, RNS) formed in the plasma with biomolecules, present in eukaryotic cells, which play a role in cancer (treatment). More specifically, I will apply classical molecular dynamics and density functional based tight binding simulations, and I will study three types of biomolecules, which play a crucial role in cancer (treatment): (1) a phospholipid bilayer (PLB) as model system for the cell membrane, (2) a part of a DNA string and (3) peptides, as a model system for proteins. I will investigate how the ROS and RNS interact with these biomolecules, which reaction products are formed, and how this can lead to apoptosis (cell death). This research will contribute to a better understanding of the role of plasmas in cancer treatment.

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  • Research Project

Computer simulations of gold-catalyzed growth of carbon nanotubes at the atomic scale. 01/10/2014 - 30/09/2017

Abstract

Recently, Au-catalyzed plasma enhanced chemical-vapor deposition (PECVD) has been shown to significantly narrow the chirality distribution. However, actual control still remains unachieved and moreover, very little is known about the underpinning fundamental mechanisms of chirality formation. In this project, I therefore envisage to use atomistic simulations to investigate these mechanisms and how these mechanisms may be controlled through the PECVD process conditions in order to obtain a definable and predictable CNT structure and chirality. I will therefore investigate the role of several plasma effects, including the electric field, plasma-generated radicals, ion bombardment and etching. By comparing Au-catalyzed CNT growth to Ni-catalyzed growth, the specific role of the catalyst in PECVD will be investigated as well.

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Towards a fundamental understanding of plasma-TiO2 catalyst interaction for greenhouse conversion. 01/10/2014 - 30/09/2016

Abstract

In this PhD project, we will build more insight in these fundamental processes on an anatase TiO2 catalyst surface, by means of state-of-the-art computer simulations. The plasma-catalyst interactions will be studied on the atomic scale by a combination of various simulations techniques. These techniques are based on an interatomic potential ("force field") that governs all atomic interactions. First, force field parameters for the Ti/O/C/H system will be developed, in collaboration with various other research groups in Flanders. Subsequently, reaction mechanisms and corresponding reaction rate coefficients for all relevant plasma species interacting with the TiO2 catalyst surface will be studied by nudged elastic band (NEB) and force biased Monte Carlo (MC) simulations. Finally, also the actual plasma catalysis process itself will be simulated by molecular dynamics (MD) and hybrid MD/MC simulations. These results will provide the necessary knowledge of the plasma/catalyst interaction, required for controlling and steering the conversion process of greenhouse gases into value-added chemicals.

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Multi-timescale atomistic modeling of plasma catalysis and plasma-based growth of carbon nanostructures. 01/10/2014 - 30/09/2016

Abstract

In this project I will develop a novel atomic scale simulation tool to unravel the fundamental mechanisms underpinning complex plasma-based processes. Specifically, I will concentrate on plasma catalysis, which is envisaged to provide an energy efficient route for greenhouse gas conversion into value-added chemicals, and plasma-based growth of carbon nanostructures, which holds promise to offer control on structure and composition, unattainable by thermal methods.

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Computer modeling for a better insight in the underlying mechanisms of plasma catalysis. 01/01/2014 - 31/12/2017

Abstract

Plasma catalysis is gaining increasing interest in environmental applications, e.g. for the conversion of greenhouse gases into value-added chemicals or new fuels. However, the fundamental mechanisms of plasma-catalyst interaction are virtually unknown. In this project, we hope to obtain more insight in these fundamental processes, by computer modeling and experimental validation.

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Characterisation and modeling of the initial growth and stability of anisotropic Au and Au/Ag nanoparticles at the atomic scale. 01/01/2014 - 31/12/2017

Abstract

The overall goal of this project is to characterise and simulate the growth and stability of anisotropic Au and Au/Ag nanocrystals at the atomic scale. In order to reach this final objective, our intermediate technical goals are: • To experimentally determine the p osition and chemical nature of each individual atom in anisotropic Au and Au/Ag NP's. • To develop a reactive force field required for the atomistic simulations.

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Mechanical properties and chemical bonding at the interfaces in polymer-based composite materials (InterPoCo). 01/03/2013 - 28/02/2017

Abstract

The main goals of the SB01 project "Mechanical properties and chemical bonding at the interfaces in polymer-based composite materiais" (InterPoCo) within the H-INT-S program are to (i) develop and apply a set of experimental and computational tools for comprehensive structural, compositional and quantitative mechanical characterisation of the interfaces in polymer-based composites at na no- and microscale level, (ii) to measure and predict structural, electronical, compositional, thermodynamica I and mechanical properties of bulk polymers and interfaces in polymer-based composites, (iii) to validate and improve the prediction reliability by emphasizing the interplay between modelling and experimental data obtained using a high-throughput approach and advanced characterisation results and (iv) to provide currently unavailable information on the above aspects to the running and future vertical SIBO programs.

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Modeling of plasma and plasma-cell interaction for a better understanding of plasma medicine applications. 01/01/2013 - 31/12/2016

Abstract

The aim of this project is to obtain a better insight in plasma-cell interactions on the atomic scale, and specifically on plasma-bacteria interactions. For this purpose, hybrid MD / Monte Carlo (MC) simulations will be performed, for the plasma species bombarding the "substrate" (i.e., bacteria) to be treated. The plasma species and their fluxes will be determined from plasma modeling. Therefore, this project is a combination of plasma modeling and modeling of plasma-bacteria interactions.

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Towards a fundamental understanding of plasma - TiO2 catalyst interaction for greenhouse gas conversion. 01/10/2012 - 30/09/2014

Abstract

In this PhD project, we will build more insight in these fundamental processes on an anatase TiO2 catalyst surface, by means of state-of-the-art computer simulations. The plasma-catalyst interactions will be studied on the atomic scale by a combination of various simulations techniques. These techniques are based on an interatomic potential ("force field") that governs all atomic interactions. First, force field parameters for the Ti/O/C/H system will be developed, in collaboration with various other research groups in Flanders. Subsequently, reaction mechanisms and corresponding reaction rate coefficients for all relevant plasma species interacting with the TiO2 catalyst surface will be studied by nudged elastic band (NEB) and force biased Monte Carlo (MC) simulations. Finally, also the actual plasma catalysis process itself will be simulated by molecular dynamics (MD) and hybrid MD/MC simulations. These results will provide the necessary knowledge of the plasma/catalyst interaction, required for controlling and steering the conversion process of greenhouse gases into value-added chemicals.

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  • Research Project

Modelling transport of CO2 through porous structures during carbonation reaction. 01/07/2012 - 30/09/2013

Abstract

In this project, the carbonation processes leading to the production of carbonates through reaction between magnesium/calcium-rich minerals that typically occur in waste materials and carbon dioxide (C02) will be investigated by numerical modelling. The aim is to be able to optimise the parameters that influence the carbonation process in order to improve the transition of the process from lab to pilot scale.

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  • Research Project

Atomistic simulations of plasma-enhanced chemical vapor deposition of single walled carbon nanotubes 01/07/2011 - 31/12/2015

Abstract

Single walled carbon nanotubes ("SWNTs") are hollow cylindrical structures consisting of a hexagonal carbon network. Their unique properties, such as extreme strength, very high thermal conductivity and structure dependent bandgap, offer perspective on various applications, in e.g. nanoelectronics, as chemical sensors or as induced field emitters. Such applications, however, require precise control over fundamental properties of the SWNTs. This control is currently lacking. Especially control over the chirality of the SWNT, which is directly responsible for the bandbap, is desired. Plasma-enhanced chemical vapor deposition ("PECVD") is regarded as one of the most promising deposition tools to accomplish this control. However, the underlying fundamental growth mechanisms are largely unknown. In this project, we therefore wish to investigate various PECVD-specific processes and process parameters in order to gain insight in the growth mechanisms, aiming at gaining control over the resulting SWNT properties. We wish to accomplish this goal by using a state-of-the-art hybrid Molecular Dynamics / force biased Monte Carlo simulation model, that allows us to simulate self-consistently all relevant processes at the atomic scale. Specifically, we plan (i) to optimize the existing simulation model in order to reduce the required computation time and extend the model to PECVD-growth; (ii) to perform specific simulations to simulate the growth of SWNTs under realistic (PECVD) process conditions on nickel nanocatalysts; (iii) to perform parameter studies that allow us to investigate the effect of the variation of precisely one parameter at a time, in order to determine how we can influence the growth process; and (iv) to develop a force field parametrization for Ni/Fe alloys to be used in the interatomic potential, and subsequent simulation of the PECVD-growth of SWNTs on Ni/Fe nanocatalysts. The innovative character of this project consists of (i) the use of the accurate interatomic potential in combination with the use of the hybrid MD/MC model that takes into account both short time scale as well as long time scale events; (ii) the study of SWNT growth in a PECVD-setup by means of atomistic simulations; and (iii) de development and application of Ni/Fe force field parameters for the simulation of PECVD-growth of SWNTs on Ni/Fe nanocatalysts. Although this project is indeed very innovative (both regarding the used methodology as the goals we are aiming for), we believe that this project is very feasible: indeed, we have already proven the effectivity of the simulation model in simulating the growth of SWNTs under thermal CVD conditions. Furthermore, we have access to all required tools needed to simulate the PECVD-specific process conditions. We therefore believe that we will be able to unravel fundamental processes in PECVD growth of SWNTs and to gain insight in this promising but until now at the atomic level nearly unexplored process.

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  • Research Project

Numerical simulations on the atomic scale of nanotechnological C- and Si-materials. 01/10/2010 - 30/11/2011

Abstract

In this project, we wish to investigate the fundamental formation processes that give rise to specific carbon and silicon nanomaterials: (ultra)nanocrystalline diamond, carbon nanotubes, amorphous hydrogenated carbon, and nanocrystalline silicon. The objective is gaining control over their structure in order to tune their properties making them suitable for real life applications. This requires insight into the relevant mechanisms on the atomic scale. Therefore, we will perform atomistic simulations of the growth process under realistic growth conditions, in strong collaboration with experimental groups for validation and further model improvements.

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Atomistic multi-time scale simulations of catalyzed carbon nanotube growth 01/01/2009 - 31/12/2012

Abstract

This research project aims at bringing atomistic simulations closer to experimental conditions by developing realistic interatomic M-C-H interaction potentials and implementing long-time scale algorithms.

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  • Research Project

Combined numerical simulations of the growth of nanoparticles in reactive plasmas and the deposition of nanomaterials. 01/10/2007 - 30/09/2010

Abstract

The aim of this project is to obtain a better insight, by means of numerical simulations, in the behavior of reactive carbon-based plasmas, used for the formation and deposition of nanostructured carbon films and nanomaterials (such as (U)NCD and CNT), as well as about the formation process of the nanomaterials itself. We wish to describe in a fully integrated way the formation, growth and behavior of the nanoparticles in the plasma, the interaction of these particles with the substrate and the walls, and the formation of the nanomaterials.

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Mathematical simulation of the deposition of diamond-like carbon (DLC) films. 01/01/2004 - 31/12/2005

Abstract

In this project, computer simulations are performed to investigate the deposition of thin diamond-like carbon (DLC) films. In a first step, molecular dynamics (MD) simulations are used to study chemisorption reactions taking place during DLC-deposition. Molecular dynamics are based on the use of a suitable interatomic potential, from which the forces on all atoms in a system of atoms are calculated in a self-consistent way. The atom's spatial trajectory, as governed by Newtons laws, is integrated explicitly in time. Therefore, using this type of simulations, detailed information regarding film growth, growth mechanisms and film structure on the atomic level can be obtained. In a second step, physisorption is included by changing the interatomic potential, such that it is suited both for chemisorption and physisorption. Finally, diffusion of particles at the substrate will also be included. This can be done by so-called time-dependent Monte Carlo (TDMC) calculations. A TDMC model will be developed, and coupled to the MD model. Ultimately, this will lead to a model which is capable of simulating DLC film.

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  • Research Project

Mathematical simulation of a radiofrequent capacitively coupled CH4/H2-plasma and the deposition of diamond-like-carbon (DLC) films. 01/01/2002 - 31/12/2003

Abstract

A low-pressure CH4/H2 plasma will be simulated using a combined fluid / Monte Carlo model. This model yields data like the flux and energy of particles impinging on a substrate. These impinging particles lead to diamand-like carbon film growth. This film growth will be simulated using a Molecular Dynamics model. Also, we will combine the plasma model and the film growth model. The goal is to gain insight into the underlying mechanisms of film growth, and to obtain information about the resulting film, as its structure and composition.

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  • Research Project