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Author (up) Khalilov, U.; Pourtois, G.; van Duin, A.C.T.; Neyts, E.C.
Title On the c-Si\mid a-SiO2 interface in hyperthermal Si oxidation at room temperature Type A1 Journal article
Year 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 116 Issue 41 Pages 21856-21863
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The exact structure and properties of the Si vertical bar SiO2 interface are very important in microelectronics and photovoltaic devices such as metal-oxide-semiconductor field-effect transistors (MOSFETs) and solar cells. Whereas Si vertical bar SiO2 structures are traditionally produced by thermal oxidation, hyperthermal oxidation shows a number of promising advantages. However, the Si vertical bar SiO2 interface induced in hyperthermal Si oxidation has not been properly investigated yet. Therefore, in this work, the interface morphology and interfacial stresses during hyperthermal oxidation at room temperature are studied using reactive molecular dynamics simulations based on the ReaxFF potential. Interface thickness and roughness, as well as the bond length and bond angle distributions in the interface are discussed and compared with other models developed for the interfaces induced by traditional thermal oxidation. The formation of a compressive stress is observed. This compressive stress, which at the interface amounts about 2 GPa, significantly slows down the inward silica growth. This value is close to the experimental value in the Si vertical bar SiO2 interface obtained in traditional thermal oxidation.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000309902100026 Publication Date 2012-09-26
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 27 Open Access
Notes Approved Most recent IF: 4.536; 2012 IF: 4.814
Call Number UA @ lucian @ c:irua:102167 Serial 2458
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Author (up) Khalilov, U.; Pourtois, G.; van Duin, A.C.T.; Neyts, E.C.
Title Self-limiting oxidation in small-diameter Si nanowires Type A1 Journal article
Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 24 Issue 11 Pages 2141-2147
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Recently, core shell silicon nanowires (Si-NWs) have been envisaged to be used for field-effect transistors and photovoltaic applications. In spite of the constant downsizing of such devices, the formation of ultrasmall diameter core shell Si-NWs currently remains entirely unexplored. We report here on the modeling of the formation of such core shell Si-NWs using a dry thermal oxidation of 2 nm diameter (100) Si nanowires at 300 and 1273 K, by means of reactive molecular dynamics simulations using the ReaxFF potential. Two different oxidation mechanisms are discussed, namely a self-limiting process that occurs at low temperature (300 K), resulting in a Si core I ultrathin SiO2 silica shell nanowire, and a complete oxidation process that takes place at a higher temperature (1273 K), resulting in the formation of an ultrathin SiO2 silica nanowire. The oxidation kinetics of both cases and the resulting structures are analyzed in detail. Our results demonstrate that precise control over the Si-core radius of such NWs and the SiOx (x <= 2.0) oxide shell is possible by controlling the growth temperature used during the oxidation process.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000305092600021 Publication Date 2012-05-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 45 Open Access
Notes Approved Most recent IF: 9.466; 2012 IF: 8.238
Call Number UA @ lucian @ c:irua:99079 Serial 2976
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Author (up) 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 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 (up) 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 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 (up) 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 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 (up) Khalilov, U.; Yusupov, M.; Bogaerts, A.; Neyts, E.C.
Title Selective Plasma Oxidation of Ultrasmall Si Nanowires Type A1 Journal article
Year 2016 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 120 Issue 120 Pages 472-477
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Device performance of Si|SiOx core-shell based nanowires critically depends on the exact control over the oxide thickness. Low-temperature plasma oxidation is a highly promising alternative to thermal oxidation allowing for improved control over the oxidation process, in particular for ultrasmall Si nanowires. We here elucidate the room temperature plasma oxidation mechanisms of ultrasmall Si nanowires using hybrid molecular dynamics / force-bias Monte Carlo simulations. We demonstrate how the oxidation and concurrent water formation mechanisms are a function of the oxidizing plasma species and we demonstrate how the resulting core-shell oxide thickness can be controlled through these species. A new mechanism of water formation is discussed in detail. The results provide a detailed atomic level explanation of the oxidation process of highly curved Si surfaces. These results point out a route toward plasma-based formation of ultrathin core-shell Si|SiOx nanowires at room temperature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000368562200057 Publication Date 2015-12-21
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 3 Open Access
Notes U.K. and M.Y. gratefully acknowledge financial support from the Research Foundation – Flanders (FWO), Grants 12M1315N and 1200216N. 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. We thank Prof. A. C. T. van Duin for sharing the ReaxFF code. Approved Most recent IF: 4.536
Call Number c:irua:130677 Serial 4002
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Author (up) Khalilov, U.; Yusupov, M.; Eshonqulov, Gb.; Neyts, Ec.; Berdiyorov, Gr.
Title Atomic level mechanisms of graphene healing by methane-based plasma radicals Type A1 Journal article
Year 2023 Publication FlatChem Abbreviated Journal FlatChem
Volume 39 Issue Pages 100506
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 Editor
Language Wos 000990342500001 Publication Date 2023-04-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2452-2627 ISBN Additional Links UA library record; WoS full record
Impact Factor 6.2 Times cited Open Access OpenAccess
Notes U.K., M.Y. and G.B.E. acknowledge the support of the Agency for Innovative Development of the Republic of Uzbekistan (Grant numbers F-FA-2021-512 and FZ-2020092435). The computational resources and services used in this work were partially provided by the HPC core facility CalcUA of the Universiteit Antwerpen and VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government. Approved Most recent IF: 6.2; 2023 IF: NA
Call Number PLASMANT @ plasmant @c:irua:197442 Serial 8813
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Author (up) Khan, A.W.; Jan, F.; Saeed, A.; Zaka-ul-Islam, M.; Abrar, M.; Khattak, N.A.D.; Zakaullah, M.
Title Comparative study of electron temperature and excitation temperature in a magnetic pole enhanced-inductively coupled argon plasma Type A1 Journal article
Year 2013 Publication Current applied physics Abbreviated Journal Curr Appl Phys
Volume 13 Issue 7 Pages 1241-1246
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Magnetic Pole Enhanced-Inductively Coupled Plasmas (MaPE-ICPs) in analogy to the conventional ICPs exhibit two modes of operation, depending on the power coupling mechanism, i.e., a low power mode with dominant capacitive coupling (E-mode) and a high power mode with dominant inductive coupling (H-mode). A comparative study of the electron temperature measured by a Langmuir probe (T-e(LP)) and the electron excitation temperature (T-exc(OES)) determined by Optical Emission Spectroscopy (OES) is reported in the two distinct modes of a MaPE-ICP operated in argon. The dependence of T-e(LP), T-exc(OES) and their ratio (T-e(LP)/T-exc(OES)) on applied power (5-50 W) and gas pressure (15-60 mTorr) is explored, and the validity of T-exc(OES) as an alternative diagnostic to T-e(LP) is tested in the two modes of MaPE-ICP. The OES based non-invasive measurement of the plasma parameters such as electron temperature is very useful for plasma processing applications in which probe measurements are limited. (C) 2013 Elsevier B. V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000322631400014 Publication Date 2013-04-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1567-1739; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.971 Times cited 13 Open Access
Notes Approved Most recent IF: 1.971; 2013 IF: 2.026
Call Number UA @ lucian @ c:irua:110718 Serial 421
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Author (up) Khanam, A.; Vohra, A.; Slotte, J.; Makkonen, I.; Loo, R.; Pourtois, G.; Vandervorst, W.
Title A demonstration of donor passivation through direct formation of V-As-i complexes in As-doped Ge1-XSnx Type A1 Journal article
Year 2020 Publication Journal Of Applied Physics Abbreviated Journal J Appl Phys
Volume 127 Issue 19 Pages 195703
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Positron annihilation spectroscopy in the Doppler and coincidence Doppler mode was applied on Ge1 xSnx epitaxial layers, grown by chemical vapor deposition with different total As concentrations (1019-1021 cm3), high active As concentrations (1019 cm3), and similar Sn concentrations (5.9%-6.4%). Positron traps are identified as mono-vacancy complexes. Vacancy-As complexes, V-Asi, formed during the growth were studied to deepen the understanding of the electrical passivation of the Ge1 xSnx:As epilayers. Larger monovacancy complexes, V-Asi (i 2), are formed as the As doping increases. The total As concentration shows a significant impact on the saturation of the number of As atoms (i 1/4 4) around the vacancies in the sample epilayers. The presence of V-Asi complexes decreases the dopant activation in the Ge1 xSnx:As epilayers. Furthermore, the presence of Sn failed to hinder the formation of larger V-Asi complexes and thus failed to reduce the donor-deactivation.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000536196000003 Publication Date 2020-05-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.2 Times cited Open Access
Notes ; ; Approved Most recent IF: 3.2; 2020 IF: 2.068
Call Number UA @ admin @ c:irua:170252 Serial 6447
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Author (up) Khosravian, N.; Bogaerts, A.; Huygh, S.; Yusupov, M.; Neyts, E.C.
Title How do plasma-generated OH radicals react with biofilm components? Insights from atomic scale simulations Type A1 Journal article
Year 2015 Publication Biointerphases Abbreviated Journal Biointerphases
Volume 10 Issue 10 Pages 029501
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The application of nonthermal atmospheric pressure plasma is emerging as an alternative and efficient technique for the inactivation of bacterial biofilms. In this study, reactive molecular dynamics simulations were used to examine the reaction mechanisms of hydroxyl radicals, as key reactive oxygen plasma species in biological systems, with several organic molecules (i.e., alkane, alcohol, carboxylic acid, and amine), as prototypical components of biomolecules in the biofilm. Our results demonstrate that organic molecules containing hydroxyl and carboxyl groups may act as trapping agents for the OH radicals. Moreover, the impact of OH radicals on N-acetyl-glucosamine, as constituent component of staphylococcus epidermidis biofilms, was investigated. The results show how impacts of OH radicals lead to hydrogen abstraction and subsequent molecular damage. This study thus provides new data on the reaction mechanisms of plasma species, and particularly the OH radicals, with fundamental components of bacterial biofilms.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000357195600019 Publication Date 2014-12-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1934-8630;1559-4106; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.603 Times cited 10 Open Access
Notes Approved Most recent IF: 2.603; 2015 IF: 3.374
Call Number c:irua:121371 Serial 1492
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Author (up) Khosravian, N.; Kamaraj, B.; Neyts, E.C.; Bogaerts, A.
Title Structural modification of P-glycoprotein induced by OH radicals: Insights from atomistic simulations Type A1 Journal article
Year 2016 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
Volume 6 Issue 6 Pages 19466
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract This study reports on the possible effects of OH radical impact on the transmembrane domain 6 of P-glycoprotein, TM6, which plays a crucial role in drug binding in human cells. For the first time, we employ molecular dynamics (MD) simulations based on the self-consistent charge density functional tight binding (SCC-DFTB) method to elucidate the potential sites of fragmentation and mutation in this domain upon impact of OH radicals, and to obtain fundamental information about the underlying reaction mechanisms. Furthermore, we apply non-reactive MD simulations to investigate the long-term effect of this mutation, with possible implications for drug binding. Our simulations indicate that the interaction of OH radicals with TM6 might lead to the breaking of C-C and C-N peptide bonds, which eventually cause fragmentation of TM6. Moreover, according to our simulations, the OH radicals can yield mutation in the aromatic ring of phenylalanine in TM6, which in turn affects its structure. As TM6 plays an important role in the binding of a range of cytotoxic drugs with P-glycoprotein, any changes in its structure are likely to affect the response of the tumor cell in chemotherapy. This is crucial for cancer therapies based on reactive oxygen species, such as plasma treatment.
Address Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000369573900001 Publication Date 2016-02-09
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 7 Open Access
Notes The authors acknowledge financial support from the Fund for Scientific Research (FWO) Flanders, grant number G012413N. 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 c:irua:131610 Serial 4031
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Author (up) Klinkhammer, C.; Verlackt, C.; Smilowicz, D.; Kogelheide, F.; Bogaerts, A.; Metzler-Nolte, N.; Stapelmann, K.; Havenith, M.; Lackmann, J.-W.
Title Elucidation of plasma-induced chemical modifications on glutathione and glutathione disulphide Type A1 Journal article
Year 2017 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
Volume 7 Issue Pages 13828
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Cold atmospheric pressure plasmas are gaining increased interest in the medical sector and clinical trials to treat skin diseases are underway. Plasmas are capable of producing several reactive oxygen and nitrogen species (RONS). However, there are open questions how plasma-generated RONS interact on a molecular level in a biological environment, e.g. cells or cell components. The redox pair glutathione (GSH) and glutathione disulphide (GSSG) forms the most important redox buffer in organisms responsible for detoxification of intracellular reactive species. We apply Raman spectroscopy, mass spectrometry, and molecular dynamics simulations to identify the time-dependent chemical modifications on GSH and GSSG that are caused by dielectric barrier discharge under ambient conditions. We find GSSG, S-oxidised glutathione species, and S-nitrosoglutathione as oxidation products with the latter two being the final products, while glutathione sulphenic acid, glutathione sulphinic acid, and GSSG are rather reaction intermediates. Experiments using stabilized pH conditions revealed the same main oxidation products as were found in unbuffered solution, indicating that the dominant oxidative or nitrosative reactions are not influenced by acidic pH. For more complex systems these results indicate that too long treatment times can cause difficult-to-handle modifications to the cellular redox buffer which can impair proper cellular function.
Address
Corporate Author Thesis
Publisher Nature Publishing Group Place of Publication London Editor
Language Wos 000413401300003 Publication Date 2017-10-17
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 17 Open Access OpenAccess
Notes Approved Most recent IF: 4.259
Call Number UA @ lucian @ c:irua:146666 Serial 4783
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Author (up) Koelman, P.; Heijkers, S.; Tadayon Mousavi, S.; Graef, W.; Mihailova, D.; Kozak, T.; Bogaerts, A.; van Dijk, J.
Title A Comprehensive Chemical Model for the Splitting of CO2in Non-Equilibrium Plasmas: A Comprehensive Chemical Model for CO2Splitting Type A1 Journal article
Year 2017 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym
Volume 14 Issue 14 Pages 1600155
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract An extensive CO2 plasmamodel is presented that is relevant for the production of ‘‘solar fuels.’’ It is based on reaction rate coefficients fromrigorously reviewed literature, and is augmented with reactionrate coefficients that are obtained fromscaling laws.The input data set,which is suitable for usage with the plasma simulation software Plasimo (https://plasimo.phys.tue.nl/), is available via the Plasimo and publisher’s websites.1 The correctness of this model implementation has been established by independent ZDPlasKin implementation (http://www.zdplaskin.

laplace.univ-tlse.fr/), to verify that the results agree. Results of these ‘‘global models’’ are presented for a DBD plasma reactor.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000403074000009 Publication Date 2016-10-17
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 21 Open Access Not_Open_Access
Notes Dutch Technology Foundation STW; Ministerie van Economische Zaken; Hercules Foundation; Acknowledgements: This research is supported by the Dutch Technology Foundation STW, which is part of the Netherlands Organization for Scientific Research (NWO), and which is partly funded by the Ministry of Economic Affairs. Furthermore, we acknowledge financial support from the IAP/7 (Inter-university Attraction Pole) program PSI-Physical Chemistry of Plasma- Surface Interactions by the Belgian Federal Office for Science Policy (BELSPO). Part of the calculations were carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. Approved Most recent IF: 2.846
Call Number PLASMANT @ plasmant @ c:irua:142643 Serial 4565
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Author (up) Kolev, I.; Bogaerts, A.
Title Calculation of gas heating in a dc sputter magnetron Type A1 Journal article
Year 2008 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 104 Issue 9 Pages 093301,1-093301,8
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The effect of gas heating in laboratory sputter magnetrons is investigated by means of numerical modeling. The model is two-dimensional in the coordinate space and three-dimensional in the velocity space based on the particle-in-cellMonte Carlo collisions technique. It is expanded in a way that allows the inclusion of the neutral plasma particles (fast gas atoms and sputtered atoms), which makes it possible to calculate the gas temperature and its influence on the discharge behavior in a completely self-consistent way. The results of the model are compared to experimental measurements and to other existing simulation results. The results show that gas heating is pressure dependent (rising with the increase in the gas pressure) and should be taken into consideration at pressures above 10 mTorr.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000260941700017 Publication Date 2008-11-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 19 Open Access
Notes Approved Most recent IF: 2.068; 2008 IF: 2.201
Call Number UA @ lucian @ c:irua:71286 Serial 267
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Author (up) Kolev, I.; Bogaerts, A.
Title Detailed numerical investigation of a DC sputter magnetron Type A1 Journal article
Year 2006 Publication IEEE transactions on plasma science Abbreviated Journal Ieee T Plasma Sci
Volume 34 Issue 3 Pages 886-894
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000238582700019 Publication Date 2006-06-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0093-3813; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.052 Times cited 28 Open Access
Notes Approved Most recent IF: 1.052; 2006 IF: 1.144
Call Number UA @ lucian @ c:irua:58198 Serial 667
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Author (up) Kolev, I.; Bogaerts, A.
Title Numerical models of the planar magnetron glow discharges Type A1 Journal article
Year 2004 Publication Contributions to plasma physics Abbreviated Journal Contrib Plasm Phys
Volume 44 Issue 7/8 Pages 582-588
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000225541000003 Publication Date 2004-11-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0863-1042;1521-3986; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.44 Times cited 22 Open Access
Notes Approved Most recent IF: 1.44; 2004 IF: 0.701
Call Number UA @ lucian @ c:irua:49069 Serial 2402
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Author (up) Kolev, I.; Bogaerts, A.
Title Numerical study of the sputtering in a dc magnetron Type A1 Journal article
Year 2009 Publication Journal of vacuum science and technology: A: vacuum surfaces and films Abbreviated Journal J Phys Chem C
Volume 27 Issue 1 Pages 20-28
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Molecular dynamics simulations were used to investigate the size-dependent melting mechanism of nickel nanoclusters of various sizes. The melting process was monitored by the caloric curve, the overall cluster Lindemann index, and the atomic Lindemann index. Size-dependent melting temperatures were determined, and the correct linear dependence on inverse diameter was recovered. We found that the melting mechanism gradually changes from dynamic coexistence melting to surface melting with increasing cluster size. These findings are of importance in better understanding carbon nanotube growth by catalytic chemical vapor deposition as the phase state of the catalyst nanoparticle codetermines the growth mechanism.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000263299600018 Publication Date 2009-02-03
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 66 Open Access
Notes Approved Most recent IF: 4.536; 2009 IF: 4.224
Call Number UA @ lucian @ c:irua:71634 Serial 2411
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Author (up) Kolev, I.; Bogaerts, A.
Title PIC – MCC numerical simulation of a DC planar magnetron Type A1 Journal article
Year 2006 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym
Volume 3 Issue 2 Pages 127-134
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000235628300005 Publication Date 2006-02-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1612-8850;1612-8869; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.846 Times cited 27 Open Access
Notes Approved Most recent IF: 2.846; 2006 IF: 2.298
Call Number UA @ lucian @ c:irua:56077 Serial 2621
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Author (up) Kolev, I.; Bogaerts, A.; Gijbels, R.
Title Influence of electron recapture by the cathode upon the discharge characteristics in dc planar magnetrons Type A1 Journal article
Year 2005 Publication Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics Abbreviated Journal Phys Rev E
Volume 72 Issue Pages 056402,1-11
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In dc magnetrons the electrons emitted from the cathode may return there due to the applied magnetic field. When that happens, they can be recaptured or reflected back into the discharge, depending on the value of the reflection coefficient (RC). A 2d3v (two-dimensional in coordinate and three-dimensional in velocity space) particle-in-cellMonte Carlo model, including an external circuit, is developed to determine the role of the electron recapture in the discharge processes. The detailed discharge structure as a function of RC for two pressures (4 and 25mtorr) is studied. The importance of electron recapture is clearly manifested, especially at low pressures. The results indicate that the discharge characteristics are dramatically changed with varying RC between 0 and 1. Thus, the electron recapture at the cathode appears to be a significant mechanism in magnetron discharges and RC a very important parameter in their correct quantitative description that should be dealt with cautiously.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000233603200089 Publication Date 2005-11-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1539-3755;1550-2376; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.366 Times cited 29 Open Access
Notes Approved Most recent IF: 2.366; 2005 IF: 2.418
Call Number UA @ lucian @ c:irua:54667 Serial 1621
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Author (up) Kolev, S.; Bogaerts, A.
Title A 2D model for a gliding arc discharge Type A1 Journal article
Year 2015 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 24 Issue 24 Pages 015025
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this study we report on a 2D fluid model of a gliding arc discharge in argon. Despite the 3D nature of the discharge, 2D models are found to be capable of providing very useful information about the operation of the discharge. We employ two modelsan axisymmetric and a Cartesian one. We show that for the considered experiment and the conditions of a low current arc (around 30 mA) in argon, there is no significant heating of the cathode surface and the discharge is sustained by field electron emission from the cathode accompanied by the formation of a cathode spot. The obtained discharge power and voltage are relatively sensitive to the surface properties and particularly to the surface roughness, causing effectively an amplification of the normal electric field. The arc body and anode region are not influenced by this and depend mainly on the current value. The gliding of the arc is modelled by means of a 2D Cartesian model. The arcelectrode contact points are analysed and the gliding mechanism along the electrode surface is discussed. Following experimental observations, the cathode spot is simulated as jumping from one point to another. A complete arc cycle is modelled from initial ignition to arc decay. The results show that there is no interaction between the successive gliding arcs.
Address
Corporate Author Thesis
Publisher Institute of Physics Place of Publication Bristol Editor
Language Wos 000348298200026 Publication Date 2014-12-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252;1361-6595; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 34 Open Access
Notes Approved Most recent IF: 3.302; 2015 IF: 3.591
Call Number c:irua:122538 c:irua:122538 c:irua:122538 c:irua:122538 Serial 3
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Author (up) Kolev, S.; Bogaerts, A.
Title Similarities and differences between gliding glow and gliding arc discharges Type A1 Journal article
Year 2015 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 24 Issue 24 Pages 065023
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this work we have analyzed the properties of a gliding dc discharge in argon at atmospheric pressure. Despite the usual designation of these discharges as ‘gliding arc discharges’, it was found previously that they operate in two different regimes—glow and arc. Here we analyze the differences in both regimes by means of two dimensional fluid modeling. In order to address different aspects of the discharge operation, we use two models—Cartesian and axisymmetric in a cylindrical coordinate system. The obtained results show that the two types of discharges produce a similar plasma column for a similar discharge current. However, the different mechanisms of plasma channel attachment to the cathode could produce certain differences in the plasma parameters (i.e. arc elongation), and this can affect gas treatments applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000368117100028 Publication Date 2015-11-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252;1361-6595; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 12 Open Access
Notes This work is financially supported by the Methusalem financing and by the IAP/7 (Inter-university Attraction Pole) program ‘Physical Chemistry of Plasma-Surface Interactions’ from the Belgian Federal Office for Science Policy (BELSPO). 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 Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen Approved Most recent IF: 3.302; 2015 IF: 3.591
Call Number c:irua:129214 Serial 3952
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Author (up) Kolev, S.; Bogaerts, A.
Title Three-dimensional modeling of energy transport in a gliding arc discharge in argon Type A1 Journal Article
Year 2018 Publication Plasma Sources Science & Technology Abbreviated Journal Plasma Sources Sci T
Volume 27 Issue 12 Pages 125011
Keywords A1 Journal Article; gliding arc discharge, sliding arc discharge, energy transport, fluid plasma model, atmospheric pressure plasmas; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Abstract In this work we study energy transport in a gliding arc discharge with two diverging flat

electrodes in argon gas at atmospheric pressure. The discharge is ignited at the shortest electrode

gap and it is pushed downstream by a forced gas flow. The current values considered are

relatively low and therefore a non-equilibrium plasma is produced. We consider two cases, i.e.

with high and low discharge current (28 mA and 2.8mA), and a constant gas flow of 10 lmin −1 ,

with a significant turbulent component to the velocity. The study presents an analysis of the

various energy transport mechanisms responsible for the redistribution of Joule heating to the

plasma species and the moving background gas. The objective of this work is to provide a

general understanding of the role of the different energy transport mechanisms in arc formation

and sustainment, which can be used to improve existing or new discharge designs. The work is

based on a three-dimensional numerical model, combining a fluid plasma model, the shear stress

transport Reynolds averaged Navier–Stokes turbulent gas flow model, and a model for gas

thermal balance. The obtained results show that at higher current the discharge is constricted

within a thin plasma column several hundred kelvin above room temperature, while in the low-

current discharge the combination of intense convective cooling and low Joule heating prevents

discharge contraction and the plasma column evolves to a static non-moving diffusive plasma,

continuously cooled by the flowing gas. As a result, the energy transport in the two cases is

determined by different mechanisms. At higher current and a constricted plasma column, the

plasma column is cooled mainly by turbulent transport, while at low current and an unconstricted

plasma, the major cooling mechanism is energy transport due to non-turbulent gas convection. In

general, the study also demonstrates the importance of turbulent energy transport in

redistributing the Joule heating in the arc and its significant role in arc cooling and the formation

of the gas temperature profile. In general, the turbulent energy transport lowers the average gas

temperature in the arc, thus allowing additional control of thermal non-equilibrium in the

discharge.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000454555600005 Publication Date 2018-12-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1361-6595 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited Open Access Not_Open_Access
Notes This work was supported by the European Regional Devel- opment Fund within the Operational Programme ’Science and Education for Smart Growth 2014 – 2020’ under the Project CoE ’National center of mechatronics and clean technologies’ BG05M2OP001-1.001-0008-C01, and by the Flemish Fund for Scientific Research (FWO); grant no G.0383.16N. Approved Most recent IF: 3.302
Call Number PLASMANT @ plasmant @c:irua:155973 Serial 5140
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Author (up) Kolev, S.; Paunska, T.; Trenchev, G.; Bogaerts, A.
Title Modeling the CO2 dissociation in pulsed atmospheric-pressure discharge Type P1 Proceeding
Year 2020 Publication Technologies Abbreviated Journal
Volume Issue Pages 012007
Keywords P1 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract CO2 dissociation and its subsequent conversion into added-value chemicals is a promising strategy for recycling CO2 gas into reusable products. One of the possible methods is direct plasma-induced dissociation. In this work we study the efficiency of CO2 dissociation in pulsed atmospheric-pressure gas discharge between two conducting electrodes by a 0-D numerical plasma model. The purpose of the study is to provide results on the optimal conditions of CO2 conversion with respect to the energy efficiency and dissociation by varying the maximum power density value and the pulse length. The power density is directly related to the discharge current and the reduced electric field in the discharge. We consider pulse lengths in the range from hundreds of nanosecond up to milliseconds. The results obtained show that the dissociation degree and energy efficiency are sensitive to the pulse length (duration) and the power density, so that a considerable improvement of the discharge performance can be achieved by fine-tuning these parameters. The study is intended to provide guidance in designing an experimental set-up and a power supply with the characteristics necessary to achieve optimal conversion.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000593712900007 Publication Date 2020-06-03
Series Editor Series Title Abbreviated Series Title
Series Volume 1492 Series Issue Edition
ISSN 1742-6588; 1742-6596 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:174447 Serial 6769
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Author (up) Kolev, S.; Sun, S.; Trenchev, G.; Wang, W.; Wang, H.; Bogaerts, A.
Title Quasi-Neutral Modeling of Gliding Arc Plasmas: Quasi-Neutral Modeling of Gliding Arc Plasmas Type A1 Journal article
Year 2017 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym
Volume 14 Issue 14 Pages 1600110
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The modelling of a gliding arc discharge (GAD) is studied by means of the quasineutral (QN) plasma modelling approach. The model is first evaluated for reliability and proper description of a gliding arc discharge at atmospheric pressure, by comparing with a more elaborate non-quasineutral (NQN) plasma model in two different geometries – a 2D axisymmetric and a Cartesian geometry. The NQN model is considered as a reference, since it provides a continuous self-consistent plasma description, including the near electrode regions. In general, the results of the QN model agree very well with those obtained from the NQN model. The small differences between both models are attributed to the approximations in the derivation of the QN model. The use of the QN model provides a substantial reduction of the computation time compared to the NQN model, which is crucial for the development of more complex models in three dimensions or with complicated chemistries. The latter is illustrated for (i) a reverse vortex flow(RVF) GAD in argon, and (ii) a GAD in CO2. The RVF discharge is modelled in three dimensions and the effect of the turbulent heat transport on the plasma and gas characteristics is

discussed. The GAD model in CO2 is in a 1D geometry with axial symmetry and provides results for the time evolution of the electron, gas and vibrational temperature of CO2, as well as for the molar fractions of the different species.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000403074000011 Publication Date 2016-10-04
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 Not_Open_Access
Notes Methusalem financing of the University of Antwerp; Approved Most recent IF: 2.846
Call Number PLASMANT @ plasmant @ c:irua:142982 Serial 4570
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Author (up) Kong, L.; Wang, W.; Murphy, A.B.; Xia, G.
Title Numerical analysis of direct-current microdischarge for space propulsion applications using the particle-in-cell/Monte Carlo collision (PIC/MCC) method Type A1 Journal article
Year 2017 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 50 Issue 16 Pages 165203
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Microdischarges are an important type of plasma discharge that possess several unique characteristics, such as the presence of a stable glow discharge, high plasma density and intense excimer radiation, leading to several potential applications. The intense and controllable gas heating within the extremely small dimensions of microdischarges has been exploited in microthruster technologies by incorporating a micro-nozzle to generate the thrust. This kind of microthruster has a significantly improved specific impulse performance compared to conventional cold gas thrusters, and can meet the requirements arising from the emerging development and application of micro-spacecraft. In this paper, we performed a self-consistent 2D particle-in-cell simulation, with a Monte Carlo collision model, of a microdischarge operating in a prototype micro-plasma thruster with a hollow cylinder geometry and a divergent micro-nozzle. The model takes into account the thermionic electron emission including the Schottky effect, the secondary electron emission due to cathode bombardment by the plasma ions, several different collision processes, and a non-uniform argon background gas density in the cathode-anode gap. Results in the high-pressure (several hundreds of Torr), high-current (mA) operating regime showing the behavior of the plasma density, potential distribution, and energy flux towards the hollow cathode and anode are presented and discussed. In addition, the results of simulations showing the effect of different argon gas pressures, cathode material work function and discharge voltage on the operation of the microdischarge thruster are presented. Our calculated properties are compared with experimental data under similar conditions and qualitative and quantitative agreements are reached.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000398856300001 Publication Date 2017-02-22
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 8 Open Access OpenAccess
Notes Approved Most recent IF: 2.588
Call Number UA @ lucian @ c:irua:143642 Serial 4674
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Author (up) Kosimov, D.P.; Dzhurakhalov, A.A.; Peeters, F.M.
Title Carbon clusters: from ring structures to nanographene Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue 19 Pages 195414,1-195414,12
Keywords A1 Journal article; Condensed Matter Theory (CMT); Integrated Molecular Plant Physiology Research (IMPRES); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The lowest-energy configurations of Cn(n≤55) clusters are obtained using the energy-minimization technique with the conjugate gradient method where a modified Brenner potential is invoked to describe the carbon and hydrocarbon interaction. We found that the ground-state configuration consists of a single ring for small number of C atoms and multiring structures are found with increasing n, which can be in planar, bowl-like or caplike form. Contrary to previous predictions, the binding energy Eb does not show even-odd oscillations and only small jumps are found in the Eb(n) curve as a consequence of specific types of edges or equivalently the number of secondary atoms. We found that hydrogenation of the edge atoms may change the ground-state configuration of the nanocluster. In both cases we determined the magic clusters. Special attention is paid to trigonal and hexagonal shaped carbon clusters and to clusters having a graphenelike configuration. Trigonal clusters are never the ground state while hexagonal-shaped clusters are only the ground state when they have zigzag edges.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000278142000103 Publication Date 2010-05-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 55 Open Access
Notes ; This work was supported by the Belgian Science Policy (IAP) and the Flemish Science Foundation (FWO-V1). ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:83385 Serial 278
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Author (up) Kosimov, D.P.; Dzhurakhalov, A.A.; Peeters, F.M.
Title Theoretical study of the stable states of small carbon clusters Cn (n=210) Type A1 Journal article
Year 2008 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 78 Issue 23 Pages 235433,1-235433,8
Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Both even- and odd-numbered neutral carbon clusters Cn (n=210) are systematically studied using the energy minimization method and the modified Brenner potential for the carbon-carbon interactions. Many stable configurations were found, and several new isomers are predicted. For the lowest energy stable configurations we obtained their binding energies and bond lengths. We found that for n5 the linear isomer is the most stable one while for n>5 the monocyclic isomer becomes the most stable. The latter was found to be regular for all studied clusters. The dependence of the binding energy for linear and cyclic clusters versus the cluster size n (n=210) is found to be in good agreement with several previous calculations, in particular with ab initio calculations as well as with experimental data for n=25.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000262245400119 Publication Date 2008-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 35 Open Access
Notes Approved Most recent IF: 3.836; 2008 IF: 3.322
Call Number UA @ lucian @ c:irua:76006 Serial 3613
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Author (up) Kovács, A.
Title A structured methodology for natural deep eutectic solvent selection and formulation for enzymatic reactions Type Doctoral thesis
Year 2023 Publication Abbreviated Journal
Volume Issue Pages viii, 216 p.
Keywords Doctoral thesis; Engineering sciences. Technology; 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) show great promise as media for enzymatic reactions in areas where (bio)compatibility with natural or medicinal products is a must. While in theory they can be tailored to the intended reaction to ensure optimized yields, the knowledge to date is predominantly empirical, with some mechanistic reports providing a fragmented view at best. Therefore, it is not easy to explain experimental observations, let alone make predictions. The aim of this study was to develop a structured, holistic understanding of the effects of NADES media on enzymatic reactions, distinguishing between effects on solubility, solvation, viscosity, inhibition and denaturation. Experimental and computational chemistry methods were combined to separately study the interactions between enzyme, substrate, and NADES as reaction media. The initial enzyme activity and the final conversion of vinyl laurate transesterification by immobilized Candida antarctica lipase were studied experimentally. The direct effect of NADES on the same enzyme was modeled by molecular dynamics simulation. The effect of solubility was studied by both experimental and computational methods. To predict the solubility and viscosity of NADES, data-driven models were developed by combining group contribution and machine learning methods, based on the accumulated experimental knowledge on NADES found in the literature. Finally, the composed relationships and prediction models were applied to the practical example of deacetylation of mannosylerythritol lipids (MELs). The experimental findings show that the chosen NADES system has a significant effect on both the apparent initial activity and the final conversion. However, in the simulations, the enzyme retains its original structure; moreover, NADES has an additional stabilizing effect on the enzyme. In addition, changes in the molar ratio of the compounds in NADES do not show a significant effect on the stability of the enzyme. These results indicate that the main effect of NADES on the reaction is mainly related to the substrate-solvent interactions (solvation energy) and the viscosity of the system. On the other hand, the experimental results only confirmed the significance of solvation, viscosity did not show a clear correlation with the studied reaction parameters. The machine learning models built for solubility and viscosity gave quantitative predictions of these properties. The accumulated knowledge was used to optimize the yield in the deacetylation reaction of MELs. The combination of these methods provides fundamental knowledge about the effect of NADES on biocatalysis, but the results are also applicable to other uses of NADES.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:194886 Serial 7276
Permanent link to this record
 

 
Author (up) Kovács, A.; Billen, P.; Cornet, I.; Wijnants, M.; Neyts, E.C.
Title Modeling the physicochemical properties of natural deep eutectic solvents : a review Type A1 Journal article
Year 2020 Publication Chemsuschem Abbreviated Journal Chemsuschem
Volume 13 Issue 15 Pages 3789-3804
Keywords A1 Journal article; Engineering sciences. Technology; Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Biochemical Wastewater Valorization & Engineering (BioWaVE)
Abstract Natural deep eutectic solvents (NADES) are mixtures of naturally derived compounds with a significantly decreased melting point due to the specific interactions among the constituents. NADES have benign properties (low volatility, flammability, toxicity, cost) and tailorable physicochemical properties (by altering the type and molar ratio of constituents), hence they are often considered as a green alternative to common organic solvents. Modeling the relation between their composition and properties is crucial though, both for understanding and predicting their behavior. Several efforts were done to this end, yet this review aims at structuring the present knowledge as an outline for future research. First, we reviewed the key properties of NADES and relate them to their structure based on the available experimental data. Second, we reviewed available modeling methods applicable to NADES. At the molecular level, density functional theory and molecular dynamics allow interpreting density differences and vibrational spectra, and computation of interaction energies. Additionally, properties at the level of the bulk media can be explained and predicted by semi-empirical methods based on ab initio methods (COSMO-RS) and equation of state models (PC-SAFT). Finally, methods based on large datasets are discussed; models based on group contribution methods and machine learning. A combination of bulk media and dataset modeling allows qualitative prediction and interpretation of phase equilibria properties on the one hand, and quantitative prediction of melting point, density, viscosity, surface tension and refractive indices on the other hand. In our view, multiscale modeling, combining the molecular and macroscale methods, will strongly enhance the predictability of NADES properties and their interaction with solutes, yielding truly tailorable solvents to accommodate (bio)chemical reactions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000541499100001 Publication Date 2020-05-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1864-5631 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.4 Times cited Open Access
Notes Approved Most recent IF: 8.4; 2020 IF: 7.226
Call Number UA @ admin @ c:irua:168851 Serial 6770
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Author (up) Kovács, A.; Janssens, N.; Mielants, M.; Cornet, I.; Neyts, E.C.; Billen, P.
Title Biocatalyzed vinyl laurate transesterification in natural deep eutectic solvents Type A1 Journal article
Year 2023 Publication Waste and biomass valorization Abbreviated Journal
Volume Issue Pages 1-12
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 Purpose Natural deep eutectic solvents (NADES) represent a green alternative to conventional organic solvents as reaction medium, offering more benign properties. To efficiently design NADES for biocatalysis, a better understanding of their effect on these reactions is needed. We hypothesize that this effect can be described by separately considering (1) the solvent interactions with the substrates, (2) the solvent viscosities and (3) the enzyme stability in NADES. Methods We investigated the effect of substrate solvation and viscosity on the reaction rate; and the stability of the enzyme in NADES. To this end, we monitored the conversion over time of the transesterification of vinyl laurate with 1- butanol by the lipase enzyme Candida antarctica B in NADES of different compounds and molar ratios. Results The initial reaction rate is higher in most NADES ( varying between 1.14 and 15.07 mu mol min(-1) mg(-1)) than in the reference n-hexane (4.0 mu mol min(-1) mg(-1))), but no clear relationship between viscosity and initial reaction rate was found. The increased reaction rate is most likely related to the solvation of the substrate due to a change in the activation energy of the reaction or a change in the conformation of the substrate. The enzyme retained part of its activity after the first 2 h of reaction (on average 20 % of the substrate reacted in the 2-24 h period). Enzyme incubation in ethylene glycol-based NADES resulted in a reduced reaction rate ( 15.07 vs. 3.34 mu mol min(-1) mg(-1)), but this may also be due to slow dissolution of the substrate. Conclusions The effect of viscosity seems to be marginal next to the effect of solvation and possible enzyme-NADES interaction. The enzyme retains some of its activity during the 24-hour measurements, but the enzyme incubation experiments did not yield accurate, comparable values. [GRAPHICS] .
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001117290800003 Publication Date 2023-12-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1877-2641; 1877-265x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.2 Times cited Open Access
Notes Approved Most recent IF: 3.2; 2023 IF: 1.337
Call Number UA @ admin @ c:irua:202709 Serial 9005
Permanent link to this record