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Author Neyts, E.C.; Brault, P.
Title Molecular Dynamics Simulations for Plasma-Surface Interactions: Molecular Dynamics Simulations… Type A1 Journal article
Year 2017 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym
Volume 14 Issue 14 Pages 1600145
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Plasma-surface interactions are in general highly complex due to the interplay of many concurrent processes. Molecular dynamics simulations provide insight in some of these processes, subject to the accessible time and length scales, and the availability of suitable force fields. In this introductory tutorial-style review, we aim to describe the current capabilities and limitations of molecular dynamics simulations in this field, restricting ourselves to low-temperature nonthermal plasmas. Attention is paid to the simulation of the various fundamental processes occurring, including sputtering, etching, implantation, and deposition, as well as to what extent the basic plasma components can be accounted for, including ground state and excited species, electric fields, ions, photons, and electrons. A number of examples is provided, giving an bird’s eye overview of the current state of the field.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000393184600009 Publication Date 2016-09-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1612-8850 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.846 Times cited 13 Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 2.846
Call Number PLASMANT @ plasmant @ c:irua:141758 Serial 4488
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Author Neyts, E.C.; Bal, K.M.
Title Effect of electric fields on plasma catalytic hydrocarbon oxidation from atomistic simulations Type A1 Journal article
Year 2017 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym
Volume 14 Issue 6 Pages e1600158
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The catalytic oxidative dehydrogenation of hydrocarbons is an industrially important process, in which selectivity is a key issue. We here investigate the conversion of methanol to formaldehyde on a vanadia surface employing long timescale simulations, reaching a time scale of seconds. In particular, we compare the thermal process to the case where an additional external electric field is applied, as would be the case in a direct plasma-catalysis setup. We find that the electric field influences the retention time of the molecules at the catalyst surface. These simulations provide an atomic scale insight in the thermal catalytic oxidative dehydrogenation process, and in how an external electric field may affect this process.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000403699900013 Publication Date 2016-11-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1612-8850 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.846 Times cited 2 Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 2.846
Call Number UA @ lucian @ c:irua:144210 Serial 4647
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Author Grubova, I.Y.; Surmeneva, M.A.; Huygh, S.; Surmenev, R.A.; Neyts, E.C.
Title Density functional theory study of interface interactions in hydroxyapatite/rutile composites for biomedical applications Type A1 Journal article
Year 2017 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 121 Issue 29 Pages 15687-15695
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract To gain insight into the nature of the adhesion mechanism between hydroxyapatite (HA) and rutile (rTiO(2)), the mutual affinity between their surfaces was systematically studied using density functional theory (DFT). We calculated both bulk and surface properties of HA and rTiO(2), and explored the interfacial bonding mechanism of amorphous HA (aHA) surface onto amorphous as well as stoichiometric and nonstoichiometric crystalline rTiO(2). Formation energies of bridging and subbridging oxygen vacancies considered in the rTiO(2)(110) surface were evaluated and compared with other theoretical and experimental results. The interfacial interaction was evaluated through the work of adhesion. For the aHA/rTiO(2)(110) interfaces, the work of adhesion is found to depend strongly on the chemical environment of the rTiO(2)(110) surface. Electronic analysis indicates that the charge transfer is very small in the case of interface formation between aHA and crystalline rTiO(2)(110). In contrast, significant charge transfer occurs between aHA and amorphous rTiO(2) (aTiO(2)) slabs during the formation of the interface. Charge density difference (CDD) analysis indicates that the dominant interactions in the interface have significant covalent character, and in particular the Ti-O and Ca-O bonds. Thus, the obtained results reveal that the aHA/aTiO(2) interface shows a more preferable interaction and is thermodynamically more stable than other interfaces. These results are particularly important for improving the long-term stability of HA-based implants.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000406726200022 Publication Date 2017-06-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 5 Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 4.536
Call Number UA @ lucian @ c:irua:145195 Serial 4715
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Author Vets, C.; Neyts, E.C.
Title Stabilities of bimetallic nanoparticles for chirality-selective carbon nanotube growth and the effect of carbon interstitials Type A1 Journal article
Year 2017 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 121 Issue 28 Pages 15430-15436
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Bimetallic nanoparticles play a crucial role in various applications. A better understanding of their properties would facilitate these applications and possibly even enable chirality-specific growth of carbon nanotubes (CNTs). We here examine the stabilities of NiFe, NiGa, and FeGa nanoparticles and the effect of carbon dissolved in NiFe nanoparticles through density functional theory (DFT) calculations and Born Oppenheimer molecular dynamics (BOMD) simulations. We establish that nanoparticles with more Fe in the core and more Ga on the surface are more stable and compare these results with well-known properties such as surface energy and atom size. Furthermore, we find that the nanoparticles become more stable with increasing carbon content, both at 0 K and at 700 K. These results provide a basis for further research into the chirality-specific growth of CNT's.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000406355700050 Publication Date 2017-06-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 2 Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 4.536
Call Number UA @ lucian @ c:irua:145206 Serial 4725
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Author Razzokov, J.; Yusupov, M.; Vanuytsel, S.; Neyts, E.C.; Bogaerts, A.
Title Phosphatidylserine flip-flop induced by oxidation of the plasma membrane: a better insight by atomic scale modeling Type A1 Journal article
Year 2017 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym
Volume 14 Issue 10 Pages 1700013
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We perform molecular dynamics simulations to study the flip-flop motion of phosphatidylserine (PS) across the plasma membrane upon increasing oxidation degree of the membrane. Our computational results show that an increase of the oxidation degree in the lipids leads to a decrease of the free energy barrier for translocation of PS through the membrane. In other words, oxidation of the lipids facilitates PS flip-flop motion across the membrane, because in native phospholipid bilayers this is only a “rare event” due to the high energy barriers for the translocation of PS. The present study provides an atomic-scale insight into the mechanisms of the PS flip-flop upon oxidation of lipids, as produced for example by cold atmospheric plasma, in living cells.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000413045800010 Publication Date 2017-04-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1612-8850 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.846 Times cited 9 Open Access (up) Not_Open_Access
Notes Fonds Wetenschappelijk Onderzoek, 1200216N ; Approved Most recent IF: 2.846
Call Number PLASMANT @ plasmant @c:irua:149567 Serial 4910
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Author Neyts, E.C.
Title Atomistic simulations of plasma catalytic processes Type A1 Journal article
Year 2018 Publication Frontiers of Chemical Science and Engineering Abbreviated Journal Front Chem Sci Eng
Volume 12 Issue 1 Pages 145-154
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract There is currently a growing interest in the realisation and optimization of hybrid plasma/catalyst systems for a multitude of applications, ranging from nanotechnology to environmental chemistry. In spite of this interest, there is, however, a lack in fundamental understanding of the underlying processes in such systems. While a lot of experimental research is already being carried out to gain this understanding, only recently the first simulations have appeared in the literature. In this contribution, an overview is presented on atomic scale simulations of plasma catalytic processes as carried out in our group. In particular, this contribution focusses on plasma-assisted catalyzed carbon nanostructure growth, and plasma catalysis for greenhouse gas conversion. Attention is paid to what can routinely be done, and where challenges persist.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000425156500017 Publication Date 2017-09-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2095-0179 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.712 Times cited 5 Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 1.712
Call Number UA @ lucian @ c:irua:149233 Serial 4927
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Author Nematollahi, P.; Neyts, E.C.
Title A comparative DFT study on CO oxidation reaction over Si-doped BC2N nanosheet and nanotube Type A1 Journal article
Year 2018 Publication Applied surface science Abbreviated Journal Appl Surf Sci
Volume 439 Issue 439 Pages 934-945
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this study, we performed density functional theory (DFT) calculations to investigate different reaction mechanisms of CO oxidation catalyzed by the Si atom embedded defective BC2N nanostructures as well as the analysis of the structural and electronic properties. The structures of all the complexes are optimized and characterized by frequency calculations at the M062X/6-31G* computational level. Also, The electronic structures and thermodynamic parameters of adsorbed CO and O-2 molecules over Si-doped BC2N nanostructures are examined in detail. Moreover, to investigate the curvature effect on the CO oxidation reaction, all the adsorption and CO oxidation reactions on a finite-sized armchair (6,6) Si-BC2NNT are also studied. Our results indicate that there can be two possible pathways for the CO oxidation with O-2 molecule: O-2(g) + CO(g) -> O-2(ads) + CO(ads) -> CO2(g) + O-(ads) and O-(ads) + CO(g) -> CO2(g). The first reaction proceeds via the Langmuir-Hinshelwood (LH) mechanism while the second goes through the Eley-Rideal (ER) mechanism. On the other hand, by increasing the tube diameter, the energy barrier increases due to the strong adsorption energy of the O-2 molecule which is related to its dissociation over the tube surface. Our calculations indicate that the two step energy barrier of the oxidation reaction over Si-BC2NNS is less than that over the Si-BC2NNT. Hence, Si-BC2NNS may serve as an efficient and highly activated substrate to CO oxidation rather than (4,4) Si-BC2NNT. (C) 2018 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000427457100112 Publication Date 2018-01-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.387 Times cited 8 Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 3.387
Call Number UA @ lucian @ c:irua:150745 Serial 4960
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Author Wang, Z.; Zhang, Y.; Neyts, E.C.; Cao, X.; Zhang, X.; Jang, B.W.-L.; Liu, C.-jun
Title Catalyst preparation with plasmas : how does it work? Type A1 Journal article
Year 2018 Publication ACS catalysis Abbreviated Journal Acs Catal
Volume 8 Issue 3 Pages 2093-2110
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Catalyst preparation with plasmas is increasingly attracting interest. A plasma is a partially ionized gas, consisting of electrons, ions, molecules, radicals, photons, and excited species, which are all active species for catalyst preparation and treatment. Under the influence of plasma, nucleation and crystal growth in catalyst preparation can be very different from those in the conventional thermal approach. Some thermodynamically unfavorable reactions can easily take place with plasmas. Compounds such as sulfides, nitrides, and phosphides that are produced under harsh conditions can be synthesized by plasma under mild conditions. Plasmas can produce catalysts with smaller particle sizes and controllable structure. Plasma is also a facile tool for reduction, oxidation, doping, etching, coating, alloy formation, surface treatment, and surface cleaning in a simple and direct way. A rapid and convenient plasma template removal has thus been established for zeolite synthesis. It can operate at room temperature and allows the catalyst preparation on temperature-sensitive supporting materials. Plasma is typically effective for the production of various catalysts on metallic substrates. In addition, plasma-prepared transition-metal catalysts show enhanced low-temperature activity with improved stability. This provides a useful model catalyst for further improvement of industrial catalysts. In this review, we aim to summarize the recent advances in catalyst preparation with plasmas. The present understanding of plasma-based catalyst preparation is discussed. The challenges and future development are addressed.
Address
Corporate Author Thesis
Publisher Amer chemical soc Place of Publication Washington Editor
Language Wos 000426804100055 Publication Date 2018-01-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2155-5435 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 10.614 Times cited 81 Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 10.614
Call Number UA @ lucian @ c:irua:150880 Serial 4963
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Author Heyne, M.H.; de Marneffe, J.-F.; Radu, I.; Neyts, E.C.; De Gendt, S.
Title Thermal recrystallization of short-range ordered WS2 films Type A1 Journal article
Year 2018 Publication Journal of vacuum science and technology: A: vacuum surfaces and films Abbreviated Journal J Vac Sci Technol A
Volume 36 Issue 5 Pages 05g501
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The integration of van der Waals materials in nanoelectronic devices requires the deposition of few-layered MX2 films with excellent quality crystals covering a large area. In recent years, astonishing progress in the monolayer growth of WS2 and MoS2 was demonstrated, but multilayer growth resulted often in separated triangular or hexagonal islands. These polycrystalline films cannot fully employ the specific MX2 properties since they are not connected in-plane to the other domains. To coalesce separated islands, ultrahigh-temperature postdeposition anneals in H2S are applied, which are not compatible with bare silicon substrates. Starting from the deposition of stoichiometric short-ordered films, the present work studies different options for subsequent high-temperature annealing in an inert atmosphere to form crystalline films with large grains from stoichiometric films with small grains. The rapid thermal annealing, performed over a few seconds, is compared to excimer laser annealing in the nanosecond range, which are both able to crystallize the thin WS2. The WS2 recrystallization temperature can be lowered using metallic crystallization promoters (Co and Ni). The best result is obtained using a Co cap, due to the circumvention of Co and S binary phase formation below the eutectic temperature. The recrystallization above a critical temperature is accompanied by sulfur loss and 3D regrowth. These undesired effects can be suppressed by the application of a dielectric capping layer prior to annealing. A SiO2 cap can suppress the sulfur loss successfully during annealing and reveals improved material quality in comparison to noncapped films Published by the AVS.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000444033200002 Publication Date 2018-07-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0734-2101 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.374 Times cited 2 Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 1.374
Call Number UA @ lucian @ c:irua:153671 Serial 5134
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Author Khalilov, U.; Vets, C.; Neyts, E.C.
Title Catalyzed growth of encapsulated carbyne Type A1 Journal article
Year 2019 Publication Carbon Abbreviated Journal Carbon
Volume 153 Issue Pages 1-5
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Carbyne is a novel material of current interest in nanotechnology. As is typically the case for nanomaterials, the growth process determines the resulting properties. While endohedral carbyne has been successfully synthesized, its catalyst and feedstock-dependent growth mechanism is still elusive. We here study the nucleation and growth mechanism of different carbon chains in a Ni-containing double walled carbon nanotube using classical molecular dynamics simulations and first-principles calculations. We find that the understanding the competitive role of the metal catalyst and the hydrocarbon is important to control the growth of 1-dimensional carbon chains, including Ni or H-terminated carbyne. Also, we find that the electronic property of the Ni-terminated carbyne can be tuned by steering the H concentration along the chain. These results suggest catalyst-containing carbon nanotubes as a possible synthesis route for carbyne formation.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000485054200001 Publication Date 2019-07-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited Open Access (up) Not_Open_Access
Notes Fund of Scientific Research Flanders (FWO), Belgium, 12M1318N 1S22516N ; Flemish Supercomputer Centre VSC; Hercules Foundation; Flemish Government; University of Antwerp; The authors gratefully acknowledge the financial support from the Fund of Scientific Research Flanders (FWO), Belgium, Grant numbers 12M1318N and 1S22516N. The work was carried out in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Centre VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. Approved Most recent IF: 6.337
Call Number PLASMANT @ plasmant @c:irua:160695 Serial 5187
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Author Heyne, M.H.; Marinov, D.; Braithwaite, N.; Goodyear, A.; de Marneffe, J.-F.; Cooke, M.; Radu, I.; Neyts, E.C.; De Gendt, S.
Title A route towards the fabrication of 2D heterostructures using atomic layer etching combined with selective conversion Type A1 Journal article
Year 2019 Publication 2D materials Abbreviated Journal 2D Mater
Volume 6 Issue 3 Pages 035030
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Heterostructures of low-dimensional semiconducting materials, such as transition metal dichalcogenides (MX2), are promising building blocks for future electronic and optoelectronic devices. The patterning of one MX2 material on top of another one is challenging due to their structural similarity. This prevents an intrinsic etch stop when conventional anisotropic dry etching processes are used. An alternative approach consist in a two-step process, where a sacrificial silicon layer is pre-patterned with a low damage plasma process, stopping on the underlying MoS2 film. The pre-patterned layer is used as sacrificial template for the formation of the top WS2 film. This study describes the optimization of a cyclic Ar/Cl-2 atomic layer etch process applied to etch silicon on top of MoS2, with minimal damage, followed by a selective conversion of the patterned Si into WS2. The impact of the Si atomic layer etch towards the MoS2 is evaluated: in the ion energy range used for this study, MoS2 removal occurs in the over-etch step over 1-2 layers, leading to the appearance of MoOx but without significant lattice distortions to the remaining layers. The combination of Si atomic layer etch, on top of MoS2, and subsequent Si-to-WS2 selective conversion, allows to create a WS2/MoS2 heterostructure, with clear Raman signals and horizontal lattice alignment. These results demonstrate a scalable, transfer free method to achieve horizontally individually patterned heterostacks and open the route towards wafer-level processing of 2D materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000468335500004 Publication Date 2019-04-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 6.937
Call Number UA @ admin @ c:irua:160229 Serial 5266
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Author Grubova, I.Y.; Surmeneva, M.A.; Huygh, S.; Surmenev, R.A.; Neyts, E.C.
Title Effects of silicon doping on strengthening adhesion at the interface of the hydroxyapatite-titanium biocomposite : a first-principles study Type A1 Journal article
Year 2019 Publication Computational materials science Abbreviated Journal Comp Mater Sci
Volume 159 Issue 159 Pages 228-234
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this paper we employ first-principles calculations to investigate the effect of substitutional Si doping in the amorphous calcium-phosphate (a-HAP) structure on the work of adhesion, integral charge transfer, charge density difference and theoretical tensile strengths between an a-HAP coating and amorphous titanium dioxide (a-TiO2) substrate systemically. Our calculations demonstrate that substitution of a P atom by a Si atom in a-HAP (a-Si-HAP) with the creation of OH-vacancies as charge compensation results in a significant increase of the bonding strength of the coating to the substrate. The work of adhesion of the optimized Si-doped interfaces reaches a value of up to -2.52 J m(-2), which is significantly higher than for the stoichiometric a-HAP/a-TiO2. Charge density difference analysis indicates that the dominant interactions at the interface have significant covalent character, and in particular two Ti-O and three Ca-O bonds are formed for a-Si-HAP/a-TiO2 and one Ti-O and three Ca-O bonds for a-HAP/a-TiO2. From the stress-strain curve, the Young's modulus of a-Si-HAP/a-TiO2 is calculated to be about 25% higher than that of the a-HAP/a-TiO2, and the yielding stress is about 2 times greater than that of the undoped model. Our calculations therefore demonstrate that the presence of Si in the a-HAP structure strongly alters not only the bioactivity and resorption rates, but also the mechanical properties of the a-HAP/a-TiO2 interface. The results presented here provide an important theoretical insight into the nature of the chemical bonding at the a-HAP/a-TiO2 interface, and are particularly significant for the practical medical applications of HAP-based biomaterials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000457856900023 Publication Date 2018-12-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0927-0256 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.292 Times cited 1 Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 2.292
Call Number UA @ admin @ c:irua:157480 Serial 5272
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Author Neyts, E.C.
Title Special Issue on future directions in plasma nanoscience Type Editorial
Year 2019 Publication Frontiers of Chemical Science and Engineering Abbreviated Journal Front Chem Sci Eng
Volume 13 Issue 2 Pages 199-200
Keywords Editorial; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000468848400001 Publication Date 2019-05-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2095-0179 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.712 Times cited Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 1.712
Call Number UA @ admin @ c:irua:160277 Serial 5280
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Author Kovács, A.; Yusupov, M.; Cornet, I.; Billen, P.; Neyts, E.C.
Title Effect of natural deep eutectic solvents of non-eutectic compositions on enzyme stability Type A1 Journal article
Year 2022 Publication Journal Of Molecular Liquids Abbreviated Journal J Mol Liq
Volume 366 Issue Pages 120180-17
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Biochemical Wastewater Valorization & Engineering (BioWaVE); Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)
Abstract Natural deep eutectic solvents (NADES) represent a green alternative to common organic solvents in the biochemical industry due to their benign behavior and tailorable properties, in particular as media for enzymatic reactions. However, to fully exploit their potential in enzymatic reactions, there is a need for a more fundamental understanding of how these neoteric solvents influence the course of these reac-tions. Thus, the aim of this study is to investigate the influence of NADES with various molar composi-tions on the stability and structure of enzymes, applying molecular dynamics simulations. This can help to better understand the effect of individual compounds of NADES, in addition to eutectic mixtures. More specifically, we simulate the behavior of Candida antarctica lipase B (CALB) enzyme in NADES com-posed of choline chloride with either urea, ethylene glycol or glycerol. Hereto, we monitor the NADES microstructure, the general stability of the enzyme and changes in the structure of its active sites and sur-face residues. Our simulations show that none of the studied NADES systems significantly disrupt the microstructure of the solvent or the stability of the CALB enzyme within the time scales of the simula-tions. The enzyme preserves its initial structure, size and intra-chain hydrogen bonds in all investigated compositions and, for the first time reported, also in NADES with increased hydrogen bond donating com-pound ratios. As the main novelty, our results indicate that, in addition to the composition, the molar ratio can be an additional variable to fine-tune the physicochemical properties of NADES without altering the enzyme characteristics. These findings could facilitate the development and application of task -tailored NADES media for biocatalytic processes. (c) 2022 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000865431800010 Publication Date 2022-08-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0167-7322 ISBN Additional Links UA library record; WoS full record
Impact Factor 6 Times cited Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 6
Call Number UA @ admin @ c:irua:191538 Serial 7265
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Author Faraji, F.; Neek-Amal, M.; Neyts, E.C.; Peeters, F.M.
Title Cation-controlled permeation of charged polymers through nanocapillaries Type A1 Journal article
Year 2023 Publication Physical review E Abbreviated Journal Phys Rev E
Volume 107 Issue 3 Pages 034501-34510
Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Molecular dynamics simulations are used to study the effects of different cations on the permeation of charged polymers through flat capillaries with heights below 2 nm. Interestingly, we found that, despite being monovalent, Li+ , Na+ , and K+ cations have different effects on polymer permeation, which consequently affects their transmission speed throughout those capillaries. We attribute this phenomenon to the interplay of the cations' hydration free energies and the hydrodynamic drag in front of the polymer when it enters the capillary. Different alkali cations exhibit different surface versus bulk preferences in small clusters of water under the influence of an external electric field. This paper presents a tool to control the speed of charged polymers in confined spaces using cations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000955986000006 Publication Date 2023-03-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0053 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.4 Times cited Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 2.4; 2023 IF: 2.366
Call Number UA @ admin @ c:irua:196089 Serial 7586
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Author Khalilov, U.; Uljayev, U.; Mehmonov, K.; Nematollahi, P.; Yusupov, M.; Neyts, E.C.; Neyts, E.C.
Title Can endohedral transition metals enhance hydrogen storage in carbon nanotubes? Type A1 Journal article
Year 2024 Publication International journal of hydrogen energy Abbreviated Journal
Volume 55 Issue Pages 640-610
Keywords A1 Journal article; Engineering sciences. Technology; Modelling and Simulation in Chemistry (MOSAIC); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The safe and efficient use of hydrogen energy, which is in high demand worldwide today, requires efficient hydrogen storage. Despite significant advances in hydrogen storage using carbon-based nanomaterials, including carbon nanotubes (CNTs), efforts to substantially increase the storage capacity remain less effective. In this work, we demonstrate the effect of endohedral transition metal atoms on the hydrogen storage capacity of CNTs using reactive molecular dynamics simulations. We find that an increase in the volume fraction of endohedral nickel atoms leads to an increase in the concentration of physisorbed hydrogen molecules around single-walled CNTs (SWNTs) by approximately 1.6 times compared to pure SWNTs. The obtained results provide insight into the underlying mechanisms of how endohedral transition metal atoms enhance the hydrogen storage ability of SWNTs under nearly ambient conditions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001142427400001 Publication Date 2023-11-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0360-3199 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.2 Times cited Open Access (up) Not_Open_Access
Notes Approved Most recent IF: 7.2; 2024 IF: 3.582
Call Number UA @ admin @ c:irua:202315 Serial 9006
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Author Dabaghmanesh, S.; Neek-Amal, M.; Partoens, B.; Neyts, E.C.
Title The formation of Cr2O3 nanoclusters over graphene sheet and carbon nanotubes Type A1 Journal article
Year 2017 Publication Chemical physics letters Abbreviated Journal Chem Phys Lett
Volume 687 Issue Pages 188-193
Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000412453700030 Publication Date 2017-09-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0009-2614 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.815 Times cited 2 Open Access (up) Not_Open_Access: Available from 01.11.2019
Notes ; This work was supported by SIM vzw, Technologiepark 935, BE-9052 Zwijnaarde, Belgium, within the InterPoCo project of the H-INT-S horizontal program. The computational resources and services used in this work were provided by the Vlaams Supercomputer Centrum (VSC) and the HPC infrastructure of the University of Antwerp. ; Approved Most recent IF: 1.815
Call Number UA @ lucian @ c:irua:146646 Serial 4795
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Author Khalilov, U.; Vets, C.; Neyts, E.C.
Title Molecular evidence for feedstock-dependent nucleation mechanisms of CNTs Type A1 Journal article
Year 2019 Publication Nanoscale Horizons Abbreviated Journal Nanoscale Horiz.
Volume 4 Issue 3 Pages 674-682
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Atomic scale simulations have been shown to be a powerful tool for elucidating the growth mechanisms of carbon nanotubes. The growth picture is however not entirely clear yet due to the gap between current simulations and real experiments. We here simulate for the first time the nucleation and subsequent growth of single-wall carbon nanotubes (SWNTs) from oxygen-containing hydrocarbon feedstocks using the hybrid Molecular Dynamics/Monte Carlo technique. The underlying nucleation mechanisms of Ni-catalysed SWNT growth are discussed in detail. Specifically, we find that as a function of the feedstock, different carbon fractions may emerge as the main growth species, due to a competition between the feedstock decomposition, its rehydroxylation and its contribution to etching of the growing SWNT. This study provides a further understanding of the feedstock effects in SWNT growth in comparison with available experimental evidence as well as with<italic>ab initio</italic>and other simulation data, thereby reducing the simulation–experiment gap.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000471816500011 Publication Date 2019-01-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2055-6756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 1 Open Access (up) Not_Open_Access: Available from 03.01.2020
Notes Fonds Wetenschappelijk Onderzoek, 12M1318N 1S22516N ; The authors gratefully acknowledge financial support from the Research Foundation Flanders (FWO), Belgium (Grant numbers 12M1318N and 1S22516N). The work was carried out in part using the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Centre VSC, funded by FWO and the Flemish Government (Department EWI). We thank Prof. A. C. T. van Duin for sharing the reax-code and forcefield parameters. Approved Most recent IF: NA
Call Number PLASMANT @ plasmant @UA @ admin @ c:irua:159658 Serial 5169
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Author Bal, K.M.; Neyts, E.C.
Title Overcoming Old Scaling Relations and Establishing New Correlations in Catalytic Surface Chemistry: Combined Effect of Charging and Doping Type A1 Journal article
Year 2019 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 123 Issue 10 Pages 6141-6147
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Optimization of catalytic materials for a given application is greatly constrained by linear scaling relations. Recently, however, it has been demonstrated that it is possible to reversibly modulate the chemisorption of molecules on nanomaterials by charging (i.e., injection or removal of electrons) and hence reversibly and selectively modify catalytic activity beyond structure−activity correlations. The fundamental physical relation between the properties of the material, the charging process, and the chemisorption energy, however, remains unclear, and a systematic exploration and optimization of charge-switchable sorbent materials is not yet possible. Using hybrid DFT calculations of CO2 chemisorption on hexagonal boron nitride nanosheets with several types of defects and dopants, we here reveal the existence of fundamental correlations between the electron affinity of a material and charge-induced chemisorption, show how defect engineering can be used to modulate the strength and efficiency of the adsorption process, and demonstrate that excess electrons stabilize many topological defects. We then show how these insights could be exploited in the development of new electrocatalytic materials and the synthesis of doped nanomaterials. Moreover, we demonstrate that calculated chemical properties of charged materials are highly sensitive to the employed computational methodology because of the self-interaction error, which underlines the theoretical challenge posed by such systems.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000461537400035 Publication Date 2019-03-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 5 Open Access (up) Not_Open_Access: Available from 21.02.2020
Notes Fonds Wetenschappelijk Onderzoek, 11V8915N ; Approved Most recent IF: 4.536
Call Number PLASMANT @ plasmant @UA @ admin @ c:irua:158117 Serial 5160
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Author Aussems, D.U.B.; Bal, K.M.; Morgan, T.W.; van de Sanden, M.C.M.; Neyts, E.C.
Title Mechanisms of elementary hydrogen ion-surface interactions during multilayer graphene etching at high surface temperature as a function of flux Type A1 Journal article
Year 2018 Publication Carbon Abbreviated Journal Carbon
Volume 137 Issue Pages 527-532
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In order to optimize the plasma-synthesis and modification process of carbon nanomaterials for applications such as nanoelectronics and energy storage, a deeper understanding of fundamental hydrogengraphite/graphene interactions is required. Atomistic simulations by Molecular Dynamics have proven to be indispensable to illuminate these phenomena. However, severe time-scale limitations restrict them to very fast processes such as reflection, while slow thermal processes such as surface diffusion and molecular desorption are commonly inaccessible. In this work, we could however reach these thermal processes for the first time at time-scales and surface temperatures (1000 K) similar to high-flux plasma exposure experiments during the simulation of multilayer graphene etching by 5 eV H ions. This was achieved by applying the Collective Variable-Driven Hyperdynamics biasing technique, which extended the inter-impact time over a range of six orders of magnitude, down to a more realistic ion-flux of 1023m2s1. The results show that this not only causes a strong shift from predominant ion-to thermally induced interactions, but also significantly affects the hydrogen uptake and surface evolution. This study thus elucidates H ion-graphite/graphene interaction mechanisms and stresses the importance of including long time-scales in atomistic simulations at high surface temperatures to understand the dynamics of the ion-surface system.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000440661700056 Publication Date 2018-05-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 4 Open Access (up) Not_Open_Access: Available from 25.05.2020
Notes DIFFER is part of the Netherlands Organisation for Scientific Research (NWO). K.M.B. is funded as PhD fellow (aspirant) of the FWO-Flanders (Fund for Scientific Research-Flanders), Grant 11V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government e department EWI. Approved Most recent IF: 6.337
Call Number PLASMANT @ plasmant @c:irua:152172 Serial 4993
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Author Van der Paal, J.; Verheyen, C.; Neyts, E.C.; Bogaerts, A.
Title Hampering Effect of Cholesterol on the Permeation of Reactive Oxygen Species through Phospholipids Bilayer: Possible Explanation for Plasma Cancer Selectivity Type A1 Journal article
Year 2017 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
Volume 7 Issue 7 Pages 39526
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In recent years, the ability of cold atmospheric pressure plasmas (CAPS) to selectively induce cell death in cancer cells has been widely established. This selectivity has been assigned to the reactive oxygen and nitrogen species (RONS) created in CAPs. To provide new insights in the search for an explanation

for the observed selectivity, we calculate the transfer free energy of multiple ROS across membranes containing a varying amount of cholesterol. The cholesterol fraction is investigated as a selectivity parameter because membranes of cancer cells are known to contain lower fractions of cholesterol compared to healthy cells. We find that cholesterol has a significant effect on the permeation of

reactive species across a membrane. Indeed, depending on the specific reactive species, an increasing cholesterol fraction can lead to (i) an increase of the transfer free energy barrier height and width, (ii) the formation of a local free energy minimum in the center of the membrane and (iii) the creation of extra free energy barriers due to the bulky sterol rings. In the context of plasma oncology, these observations suggest that the increased ingress of RONS in cancer cells can be explained by the decreased cholesterol fraction of their cell membrane.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000391306900001 Publication Date 2017-01-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.259 Times cited 27 Open Access (up) OpenAccess
Notes The authors acknowledge financial support from the Fund for Scientific Research (FWO) Flanders, grant number 11U5416N. The calculations were performed in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen. Approved Most recent IF: 4.259
Call Number PLASMANT @ plasmant @ c:irua:139512 Serial 4340
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Author Shirazi, M.; Neyts, E.C.; Bogaerts, A.
Title DFT study of Ni-catalyzed plasma dry reforming of methane Type A1 Journal article
Year 2017 Publication Applied catalysis : B : environmental Abbreviated Journal Appl Catal B-Environ
Volume 205 Issue 205 Pages 605-614
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract tWe investigated the plasma-assisted catalytic reactions for the production of value-added chemicalsfrom Ni-catalyzed plasma dry reforming of methane by means of density functional theory (DFT). Weinspected many activation barriers, from the early stage of adsorption of the major chemical fragmentsderived fromCH4andCO2molecules up to the formation of value-added chemicals at the surface, focusingon the formation of methanol, as well as the hydrogenation of C1and C2hydrocarbon fragments. Theactivation barrier calculations show that the presence of surface-bound H atoms and in some cases alsoremaining chemical fragments at the surface facilitates the formation of products. This implies that thehydrogenation of a chemical fragment on the hydrogenated crystalline surface is energetically favouredcompared to the simple hydrogenation of the chemical fragment at the bare Ni(111) surface. Indeed, thepresence of hydrogen modifies the electronic structure of the surface and the course of the reactions.We therefore conclude that surface-bound H atoms, and to some extent also the remaining chemicalfragments at the crystalline surface, induce the following effects: they facilitate associative desorption ofmethanol and ethane by increasing the rate of H-transfer to the adsorbed fragments while they impedehydrogenation of ethylene to ethane, thus promoting again the desorption of ethylene. Overall, they thusfacilitate the catalytic conversion of the formed fragments from CH4and CO2, into value-added chemicals.Finally, we believe that the retention of methane fragments, especially CH3, in the presence of surface-boundHatoms (as observed here for Ni) can be regarded as an identifier for the proper choice of a catalystfor the production of value-added chemicals.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000393931000063 Publication Date 2017-01-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0926-3373 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.446 Times cited 26 Open Access (up) OpenAccess
Notes Financial support from the Reactive Atmospheric Plasmaprocessing –eDucation network (RAPID), through the EU 7thFramework Programme (grant agreement no. 606889) is grate-fully acknowledged. The calculations were performed using theTuring HPC infrastructure at the CalcUA core facility of the Univer-siteit Antwerpen, a division of the Flemish Supercomputer CenterVSC, funded by the Hercules Foundation, the Flemish Approved Most recent IF: 9.446
Call Number PLASMANT @ plasmant @ c:irua:139514 Serial 4343
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Author Yusupov, M.; Van der Paal, J.; Neyts, E.C.; Bogaerts, A.
Title Synergistic effect of electric field and lipid oxidation on the permeability of cell membranes Type A1 Journal article
Year 2017 Publication Biochimica et biophysica acta : G : general subjects Abbreviated Journal Bba-Gen Subjects
Volume 1861 Issue 1861 Pages 839-847
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Background: Strong electric fields are knownto affect cell membrane permeability,which can be applied for therapeutic purposes, e.g., in cancer therapy. A synergistic enhancement of this effect may be accomplished by the presence of reactive oxygen species (ROS), as generated in cold atmospheric plasmas. Little is known about the synergy between lipid oxidation by ROS and the electric field, nor on howthis affects the cell membrane permeability.

Method: We here conduct molecular dynamics simulations to elucidate the dynamics of the permeation process under the influence of combined lipid oxidation and electroporation. A phospholipid bilayer (PLB), consisting of di-oleoyl-phosphatidylcholine molecules covered with water layers, is used as a model system for the plasma membrane.

Results and conclusions:Weshow howoxidation of the lipids in the PLB leads to an increase of the permeability of the bilayer to ROS, although the permeation free energy barriers still remain relatively high. More importantly, oxidation of the lipids results in a drop of the electric field threshold needed for pore formation (i.e., electroporation) in the PLB. The created pores in the membrane facilitate the penetration of reactive plasma species deep into the cell interior, eventually causing oxidative damage.

General significance: This study is of particular interest for plasma medicine, as plasma generates both ROS and electric fields, but it is also of more general interest for applications where strong electric fields and ROS both come into play.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000397366200012 Publication Date 2017-01-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-4165 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.702 Times cited Open Access (up) OpenAccess
Notes This work is financially supported by the Fund for Scientific Research Flanders (FWO; grant numbers: 1200216N and 11U5416N). The work was carried out using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flem Approved Most recent IF: 4.702
Call Number PLASMANT @ plasmant @ c:irua:140095 Serial 4413
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Author Verlackt, C.C.W.; Neyts, E.C.; Bogaerts, A.
Title Atomic scale behavior of oxygen-based radicals in water Type A1 Journal article
Year 2017 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 50 Issue 50 Pages 11LT01
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Cold atmospheric pressure plasmas in and in contact with liquids represent a growing field of research for various applications. Understanding the interactions between the plasma generated species and the liquid is crucial. In this work we perform molecular dynamics (MD) simulations based on a quantum mechanical method, i.e. density-functional based tight-binding (DFTB), to examine the interactions of OH radicals and O atoms in bulk water. Our calculations reveal that the transport of OH radicals through water is not only governed by diffusion, but also by an equilibrium reaction of H-abstraction with water molecules. Furthermore, when two OH radicals encounter each other, they either form a stable cluster, or react, resulting in the formation of a new water molecule and an O atom. In addition,

the O atoms form either oxywater (when in singlet configuration) or they remain stable in solution (when in triplet configuration), stressing the important role that O atoms can play in aqueous solution, and in contact with biomolecules. Our observations are in line with both experimental and ab initio results from the literature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000415252400001 Publication Date 2017-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 11 Open Access (up) OpenAccess
Notes The authors thank Peter Bruggeman (University of Minnesota, USA) and Jan Benedikt (Ruhr-Universität Bochum, Germany) for the interesting discussions regarding the existence of O in aqueous solutions. Furthermore, they acknowledge financial support from the Fund for Scientific Research (FWO) Flanders (project number G012413N). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen. Approved Most recent IF: 2.588
Call Number PLASMANT @ plasmant @ c:irua:140845 Serial 4420
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Author Khalilov, U.; Bogaerts, A.; Xu, B.; Kato, T.; Kaneko, T.; Neyts, E.C.
Title How the alignment of adsorbed ortho H pairs determines the onset of selective carbon nanotube etching Type A1 Journal article
Year 2017 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 9 Issue 9 Pages 1653-1661
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Unlocking the enormous technological potential of carbon nanotubes strongly depends on our ability to specifically produce metallic or semiconducting tubes. While selective etching of both has already been demonstrated, the underlying reasons, however, remain elusive as yet. We here present computational and experimental evidence on the operative mechanisms at the atomic scale. We demonstrate that during the adsorption of H atoms and their coalescence, the adsorbed ortho hydrogen pairs on single-walled carbon nanotubes induce higher shear stresses than axial stresses, leading to the elongation of HC–CH bonds as a function of their alignment with the tube chirality vector, which we denote as the γ-angle. As a result, the C–C cleavage occurs more rapidly in nanotubes containing ortho H-pairs with a small γ-angle. This phenomenon can explain the selective etching of small-diameter semiconductor nanotubes with a similar curvature. Both theoretical and experimental results strongly indicate the important role of the γ-angle in the selective etching mechanisms of carbon nanotubes, in addition to the nanotube curvature and metallicity effects and lead us to clearly understand the onset of selective synthesis/removal of CNT-based materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000395422800036 Publication Date 2016-12-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 6 Open Access (up) OpenAccess
Notes U. K. gratefully acknowledges financial support from the Fund of Scientific Research Flanders (FWO), Belgium (Grant No. 12M1315N). This work was also supported in part by Grant-in- Aid for Young Scientists A (Grant No. 25706028), Grant-in-Aid for Scientific Research on Innovative Areas (Grant No. 26107502) from JSPS KAKENHI. This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. The authors also thank Prof. A. C. T. van Duin for sharing the ReaxFF code and J. Razzokov for his assistance to perform the DFT calculations. Approved Most recent IF: 7.367
Call Number PLASMANT @ plasmant @ c:irua:140091 Serial 4417
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Author Heyne, M.H.; de Marneffe, J.-F.; Delabie, A.; Caymax, M.; Neyts, E.C.; Radu, I.; Huyghebaert, C.; De Gendt, S.
Title Two-dimensional WS2 nanoribbon deposition by conversion of pre-patterned amorphous silicon Type A1 Journal article
Year 2017 Publication Nanotechnology Abbreviated Journal Nanotechnology
Volume 28 Issue 28 Pages 04LT01
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We present a method for area selective deposition of 2D WS2 nanoribbons with tunable thickness on a dielectric substrate. The process is based on a complete conversion of a prepatterned, H-terminated Si layer to metallic W by WF6, followed by in situ sulfidation by H2S. The reaction process, performed at 450 degrees C, yields nanoribbons with lateral dimension down to 20 nm and with random basal plane orientation. The thickness of the nanoribbons is accurately controlled by the thickness of the pre-deposited Si layer. Upon rapid thermal annealing at 900 degrees C under inert gas, the WS2 basal planes align parallel to the substrate.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000391445100001 Publication Date 2016-12-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0957-4484 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.44 Times cited 13 Open Access (up) OpenAccess
Notes Approved Most recent IF: 3.44
Call Number UA @ lucian @ c:irua:140382 Serial 4471
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Author Khalilov, U.; Bogaerts, A.; Neyts, E.C.
Title Atomic-scale mechanisms of plasma-assisted elimination of nascent base-grown carbon nanotubes Type A1 Journal article
Year 2017 Publication Carbon Abbreviated Journal Carbon
Volume 118 Issue 118 Pages 452-457
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Selective etching allows for obtaining carbon nanotubes with a specific chirality. While plasma-assisted etching has already been used to separate metallic tubes from their semiconducting counterparts, little is known about the nanoscale mechanisms of the etching process. We combine (reactive) molecular dynamics (MD) and force-bias Monte Carlo (tfMC) simulations to study H-etching of CNTs. In particular, during the hydrogenation and subsequent etching of both the carbon cap and the tube, they sequentially transform to different carbon nanostructures, including carbon nanosheet, nanowall, and polyyne chains, before they are completely removed from the surface of a substrate-bound Ni-nanocluster.We also found that onset of the etching process is different in the cases of the cap and the tube, although the overall etching scenario is similar in both cases. The entire hydrogenation/etching process for both cases is analysed in detail, comparing with available theoretical and experimental evidences.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000401120800053 Publication Date 2017-03-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 2 Open Access (up) OpenAccess
Notes U. K. gratefully acknowledges financial support from the Research Foundation – Flanders (FWO), Belgium (Grant No. 12M1315N). The work was carried out in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Centre VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen. The authors also thank Prof. A. C. T. van Duin for sharing the ReaxFF code. Approved Most recent IF: 6.337
Call Number PLASMANT @ plasmant @ c:irua:141915 Serial 4531
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Author Khalilov, U.; Bogaerts, A.; Hussain, S.; Kovacevic, E.; Brault, P.; Boulmer-Leborgne, C.; Neyts, E.C.
Title Nanoscale mechanisms of CNT growth and etching in plasma environment Type A1 Journal article
Year 2017 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 50 Issue 50 Pages 184001
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Plasma-enhanced chemical deposition (PECVD) of carbon nanotubes has already been shown to allow chirality control to some extent. In PECVD, however, etching may occur simultaneously with the growth, and the occurrence of intermediate processes further significantly complicates the growth process.

We here employ a computational approach with experimental support to study the plasma-based formation of Ni nanoclusters, Ni-catalyzed CNT growth and subsequent etching processes, in order to understand the underpinning nanoscale mechanisms. We find that hydrogen is the dominant factor in both the re-structuring of a Ni film and the subsequent appearance of Ni nanoclusters, as well as in the CNT nucleation and etching processes. The obtained results are compared with available theoretical and experimental studies and provide a deeper understanding of the occurring nanoscale mechanisms in plasma-assisted CNT nucleation and growth.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000398300900001 Publication Date 2017-04-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 6 Open Access (up) OpenAccess
Notes UK gratefully acknowledges financial support from the Research Foundation – Flanders (FWO), Belgium (Grant No. 12M1315N). The work was carried out in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Centre VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen. The authors also thank Prof A C T van Duin for sharing the ReaxFF code. Approved Most recent IF: 2.588
Call Number PLASMANT @ plasmant @ c:irua:141918 Serial 4533
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Author Verlackt, C.C.W.; Van Boxem, W.; Dewaele, D.; Lemière, F.; Sobott, F.; Benedikt, J.; Neyts, E.C.; Bogaerts, A.
Title Mechanisms of Peptide Oxidation by Hydroxyl Radicals: Insight at the Molecular Scale Type A1 Journal article
Year 2017 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 121 Issue 121 Pages 5787-5799
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Molecular dynamics (MD) simulations were performed to provide atomic scale insight in the initial interaction between hydroxyl radicals (OH) and peptide systems in solution. These OH radicals are representative reactive oxygen species produced by cold atmospheric plasmas. The use of plasma for biomedical applications is gaining increasing interest, but the fundamental mechanisms behind the plasma modifications still remain largely elusive. This study helps to gain more insight in the underlying mechanisms of plasma medicine but is also more generally applicable to peptide oxidation, of interest for other applications. Combining both reactive and nonreactive MD simulations, we are able to elucidate the reactivity of the amino acids inside the peptide systems and their effect on their structure up to 1 μs. Additionally, experiments were performed, treating the simulated peptides with a plasma jet. The computational results presented here correlate well with the obtained experimental data and highlight the importance of the chemical environment for the reactivity of the individual amino acids, so that specific amino acids are attacked in higher numbers than expected. Furthermore, the long time scale simulations suggest that a single oxidation has an effect on the 3D conformation due to an increase in hydrophilicity and intra- and intermolecular interactions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000396969900037 Publication Date 2017-03-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 5 Open Access (up) OpenAccess
Notes Fonds Wetenschappelijk Onderzoek, G012413N ; Approved Most recent IF: 4.536
Call Number PLASMANT @ plasmant @ c:irua:142202 Serial 4537
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Author Khalilov, U.; Bogaerts, A.; Neyts, E.C.
Title Toward the Understanding of Selective Si Nano-Oxidation by Atomic Scale Simulations Type A1 Journal article
Year 2017 Publication Accounts of chemical research Abbreviated Journal Accounts Chem Res
Volume 50 Issue 50 Pages 796-804
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The continuous miniaturization of nanodevices, such as transistors, solar cells, and optical fibers, requires the controlled synthesis of (ultra)thin gate oxides (<10 nm), including Si gate-oxide (SiO2) with high quality at the atomic scale. Traditional thermal growth of SiO2 on planar Si surfaces, however, does not allow one to obtain such ultrathin oxide due to either the high oxygen diffusivity at high temperature or the very low sticking ability of incident oxygen at low temperature. Two recent techniques, both operative at low (room) temperature, have been put forward to overcome these obstacles: (i) hyperthermal oxidation of planar Si surfaces and (ii) thermal or plasma-assisted oxidation of nonplanar Si surfaces, including Si nanowires (SiNWs). These nanooxidation processes are, however, often difficult to study experimentally, due to the key intermediate processes taking place on the nanosecond time scale.

In this Account, these Si nano-oxidation techniques are discussed from a computational point of view and compared to both hyperthermal and thermal oxidation experiments, as well as to well-known models of thermal oxidation, including the Deal−Grove, Cabrera−Mott, and Kao models and several alternative mechanisms. In our studies, we use reactive molecular dynamics (MD) and hybrid MD/Monte Carlo simulation techniques, applying the Reax force field. The incident energy of oxygen species is chosen in the range of 1−5 eV in hyperthermal oxidation of planar Si surfaces in order to prevent energy-induced damage. It turns out that hyperthermal growth allows for two growth modes, where the ultrathin oxide thickness depends on either (1) only the kinetic energy of the incident oxygen species at a growth temperature below Ttrans = 600 K, or (2) both the incident energy and the growth temperature at a growth temperature above Ttrans. These modes are specific to such ultrathin oxides, and are not observed in traditional thermal oxidation, nor theoretically considered by already existing models. In the case of thermal or plasma-assisted oxidation of small Si nanowires, on the other hand, the thickness of the ultrathin oxide is a function of the growth temperature and the nanowire diameter. Below Ttrans, which varies with the nanowire diameter, partially oxidized SiNW are formed, whereas complete oxidation to a SiO2 nanowire occurs only above Ttrans. In both nano-oxidation processes at lower temperature (T < Ttrans), final sandwich c-Si|SiOx|a-SiO2 structures are obtained due to a competition between overcoming the energy barrier to penetrate into Si subsurface layers and the compressive stress (∼2−3 GPa) at the Si crystal/oxide interface. The overall atomic-simulation results strongly indicate that the thickness of the intermediate SiOx (x < 2) region is very limited (∼0.5 nm) and constant irrespective of oxidation parameters. Thus, control over the ultrathin SiO2 thickness with good quality is indeed possible by accurately tuning the oxidant energy, oxidation temperature and surface curvature.

In general, we discuss and put in perspective these two oxidation mechanisms for obtaining controllable ultrathin gate-oxide films, offering a new route toward the fabrication of nanodevices via selective nano-oxidation.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000399859800016 Publication Date 2017-04-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0001-4842 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 20.268 Times cited 5 Open Access (up) OpenAccess
Notes Fonds Wetenschappelijk Onderzoek, 12M1315N ; Approved Most recent IF: 20.268
Call Number PLASMANT @ plasmant @ c:irua:142638 Serial 4561
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