“Particle-in-cell/Monte Carlo simulation of a capacitively coupled radio frequency Ar/Cf4 discharge: effect of gas composition”. Georgieva V, Bogaerts A, Gijbels R, Journal of applied physics 93, 2369 (2003). http://doi.org/10.1063/1.1542920
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.068
Times cited: 57
DOI: 10.1063/1.1542920
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“Influence of sticking coefficients on the behavior of sputtered atoms in an argon glow discharge: modeling and comparison with experiment”. Bogaerts A, Naylor J, Hatcher M, Jones WJ, Mason R, Journal of vacuum science and technology: A: vacuum surfaces and films 16, 2400 (1998). http://doi.org/10.1116/1.581359
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.374
Times cited: 12
DOI: 10.1116/1.581359
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“Structural modification of NADPH oxidase activator (Noxa 1) by oxidative stress: An experimental and computational study”. Attri P, Park J-H, De Backer J, Kim M, Yun J-H, Heo Y, Dewilde S, Shiratani M, Choi EH, Lee W, Bogaerts A, International Journal Of Biological Macromolecules 163, 2405 (2020). http://doi.org/10.1016/j.ijbiomac.2020.09.120
Abstract: NADPH oxidases 1 (NOX1) derived reactive oxygen species (ROS) play an important role in the progression of cancer through signaling pathways. Therefore, in this paper, we demonstrate the effect of cold atmospheric plasma (CAP) on the structural changes of Noxa1 SH3 protein, one of the regulatory subunits of NOX1. For this purpose, firstly we purified the Noxa1 SH3 protein and analyzed the structure using X-ray crystallography, and subsequently, we treated the protein with two types of CAP reactors such as pulsed dielectric barrier discharge (DBD) and Soft Jet for different time intervals. The structural deformation of Noxa1 SH3 protein was analyzed by various experimental methods (circular dichroism, fluorescence, and NMR spectroscopy) and by MD simulations. Additionally, we demonstrate the effect of CAP (DBD and Soft Jet) on the viability and expression of NOX1 in A375 cancer cells. Our results are useful to understand the structural modification/oxidation occur in protein due to reactive oxygen and nitrogen (RONS) species generated by CAP.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 8.2
DOI: 10.1016/j.ijbiomac.2020.09.120
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“Streamer propagation in a packed bed plasma reactor for plasma catalysis applications”. Wang W, Kim H-H, Van Laer K, Bogaerts A, Chemical engineering journal 334, 2467 (2018). http://doi.org/10.1016/j.cej.2017.11.139
Abstract: A packed bed dielectric barrier discharge (DBD) is widely used for plasma catalysis applications, but the exact plasma characteristics in between the packing beads are far from understood. Therefore, we study here these plasma characteristics by means of fluid modelling and experimental observations using ICCD imaging, for packing materials with different dielectric constants. Our study reveals that a packed bed DBD reactor in dry air at atmospheric pressure may show three types of discharges, i.e. positive restrikes, filamentary microdischarges, which can also be localized between two packing beads, and surface discharges (so-called surface ionization
waves). Restrikes between the dielectric surfaces result in the formation of filamentary microdischarges, while surface charging creates electric field components parallel to the dielectric surfaces, leading to the formation of surface discharges. A transition in discharge mode occurs from surface discharges to local filamentary discharges between the packing beads when the dielectric constant of the packing rises from 5 to 1000. This may have implications for the efficiency of plasma catalytic gas treatment, because the catalyst activation may be limited by constraining the discharge to the contact points of the beads. The production of reactive species occurs most in the positive restrikes, the surface discharges and the local microdischarges in between the beads, and is less significant in the longer filamentary microdischarges. The faster streamer propagation and discharge development with higher dielectric constant of the packing beads leads to a faster production of reactive species. This study is of great interest for plasma catalysis, where packing beads with different dielectric constants are often used as supports for the catalytic materials. It allows us to better understand how different packing materials can influence the performance of packed bed plasma reactors for environmental applications.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.216
Times cited: 36
DOI: 10.1016/j.cej.2017.11.139
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“From the Birkeland–Eyde process towards energy-efficient plasma-based NOXsynthesis: a techno-economic analysis”. Rouwenhorst KHR, Jardali F, Bogaerts A, Lefferts L, Energy &, Environmental Science 14, 2520 (2021). http://doi.org/10.1039/D0EE03763J
Abstract: Plasma-based NO<sub>X</sub>synthesis<italic>via</italic>the Birkeland–Eyde process was one of the first industrial nitrogen fixation methods. However, this technology never played a dominant role for nitrogen fixation, due to the invention of the Haber–Bosch process. Recently, nitrogen fixation by plasma technology has gained significant interest again, due to the emergence of low cost, renewable electricity. We first present a short historical background of plasma-based NO<sub>X</sub>synthesis. Thereafter, we discuss the reported performance for plasma-based NO<sub>X</sub>synthesis in various types of plasma reactors, along with the current understanding regarding the reaction mechanisms in the plasma phase, as well as on a catalytic surface. Finally, we benchmark the plasma-based NO<sub>X</sub>synthesis process with the electrolysis-based Haber–Bosch process combined with the Ostwald process, in terms of the investment cost and energy consumption. This analysis shows that the energy consumption for NO<sub>X</sub>synthesis with plasma technology is almost competitive with the commercial process with its current best value of 2.4 MJ mol N<sup>−1</sup>, which is required to decrease further to about 0.7 MJ mol N<sup>−1</sup>in order to become fully competitive. This may be accomplished through further plasma reactor optimization and effective plasma–catalyst coupling.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 29.518
DOI: 10.1039/D0EE03763J
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“Understanding the surface diffusion processes during magnetron sputter-deposition of complex oxide Mg-Al-O thin films”. Georgieva V, Voter AF, Bogaerts A, Crystal growth &, design 11, 2553 (2011). http://doi.org/10.1021/cg200318h
Abstract: It is known that film structure may change dramatically with the extent of surface diffusion during the film growth process. In the present work, surface diffusion, induced thermally or activated by energetic impacts, is investigated theoretically under conditions appropriate for magnetron sputter-deposition of MgAlO thin films with varying stoichiometry. The distribution of surface diffusion energy barriers available to the system was determined for each stoichiometry, which allowed assessing in a qualitative way how much surface diffusion will take place on the time scale available between deposition events. The activation energy barriers increase with the Al concentration in the film, and therefore, the surface diffusion rates in the time frame of typical deposition rates drop, which can explain the decrease in crystallinity in the film structure and the transition to amorphous structure. The deposition process and the immediate surface diffusion enhanced by the energetic adatoms are simulated by means of a molecular dynamics model. The longer-time thermal surface diffusion and the energy landscape are studied by the temperature accelerated dynamics method, applied in an approximate way. The surface diffusion enhanced by the energetic impacts appears to be very important for the film structure in the low-temperature deposition regime.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.055
Times cited: 14
DOI: 10.1021/cg200318h
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“Accurate Reaction Probabilities for Translational Energies on Both Sides of the Barrier of Dissociative Chemisorption on Metal Surfaces”. Gerrits N, Jackson B, Bogaerts A, The Journal of Physical Chemistry Letters 15, 2566 (2024). http://doi.org/10.1021/acs.jpclett.3c03408
Abstract: Molecular dynamics simulations are essential for a better understanding of dissociative chemisorption on metal surfaces, which is often the rate-controlling step in heterogeneous and plasma catalysis. The workhorse quasi-classical trajectory approach ubiquitous in molecular dynamics is able to accurately predict reactivity only for high translational and low vibrational energies. In contrast, catalytically relevant conditions generally involve low translational and elevated vibrational energies. Existing quantum dynamics approaches are intractable or approximate as a result of the large number of degrees of freedom present in molecule−metal surface reactions. Here, we extend a ring polymer molecular dynamics approach to fully include, for the first time, the degrees of freedom of a moving metal surface. With this approach, experimental sticking probabilities for the dissociative chemisorption of methane on Pt(111) are reproduced for a large range of translational and vibrational energies by including nuclear quantum effects and employing full-dimensional simulations.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 5.7
DOI: 10.1021/acs.jpclett.3c03408
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“Plasma in Cancer Treatment”. Privat-Maldonado A, Bogaerts A, Cancers 12, 2617 (2020). http://doi.org/10.3390/cancers12092617
Abstract: Cancer is the second leading cause of death worldwide, and while science has advanced significantly to improve the treatment outcome and quality of life in cancer patients, there are still many issues with the current therapies, such as toxicity and the development of resistance to treatment [...]
Keywords: Editorial; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
DOI: 10.3390/cancers12092617
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“Gliding Arc Plasmatron: Providing an Alternative Method for Carbon Dioxide Conversion”. Ramakers M, Trenchev G, Heijkers S, Wang W, Bogaerts A, Chemsuschem 10, 2642 (2017). http://doi.org/10.1002/cssc.201700589
Abstract: Low-temperature plasmas are gaining a lot of interest for environmental and energy applications. A large research field in these applications is the conversion of CO2 into chemicals and fuels. Since CO2 is a very stable molecule, a key performance indicator for the research on plasma-based CO2 conversion is the energy efficiency. Until now, the energy efficiency in atmospheric plasma reactors is quite low, and therefore we employ here a novel type of plasma reactor, the gliding arc plasmatron (GAP). This paper provides a detailed experimental and computational study of the CO2 conversion, as well as the energy cost and efficiency in a GAP. A comparison with thermal conversion, other plasma types and other novel CO2 conversion technologies is made to find out whether this novel plasma reactor can provide a significant contribution to the much-needed efficient conversion of CO2. From these comparisons it becomes evident that our results are less than a factor of two away from being cost competitive and already outperform several other new technologies. Furthermore, we indicate how the performance of the GAP can still be improved by further exploiting its non-equilibrium character. Hence, it is clear that the GAP is very promising for CO2 conversion.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 7.226
Times cited: 42
DOI: 10.1002/cssc.201700589
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“Two-dimensional model of a direct current glow discharge : description of the argon metastable atoms, sputtered atoms and ions”. Bogaerts A, Gijbels R, Analytical chemistry 68, 2676 (1996). http://doi.org/10.1021/ac951206z
Abstract: A two-dimensional model is presented that describes the behavior of argon metastable atoms, copper atoms, and copper ions in an argon direct. current glow discharge, in the standard cell of the VG9000 glow discharge mass spectrometer for analyzing flat samples. The model is combined with a previously developed model for the electrons, argon ions, and atoms in the same cell to obtain an overall picture of the glow discharge, The results of the present model comprise the number densities of the described plasma species, the relative contributions of different production and loss processes for the argon metastable atoms, the thermalization profile of the sputtered copper atoms, the relative importance of the different ionization mechanisms for the copper atoms, the ionization degree of copper, the copper ion-to-argon ion density ratio, and the relative roles of copper ions, argon ions, and atoms in the sputtering process. All these quantities are calculated for a range of voltages and pressures, Moreover, since the sticking coefficient of copper atoms on solid surfaces is not well-known in the literature, the influence of this parameter on the results is briefly discussed.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 5.636
Times cited: 57
DOI: 10.1021/ac951206z
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“Atomic spectroscopy”. Bings NH, Bogaerts A, Broekaert JAC, Analytical chemistry 74, 2691 (2002). http://doi.org/10.1021/ac020190r
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.32
Times cited: 18
DOI: 10.1021/ac020190r
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“Numerical study of the size-dependent melting mechanisms of nickel nanoclusters”. Neyts EC, Bogaerts A, The journal of physical chemistry: C : nanomaterials and interfaces 113, 2771 (2009)
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.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.536
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“Cold Atmospheric Plasma Treatment for Pancreatic Cancer–The Importance of Pancreatic Stellate Cells”. Verloy R, Privat-Maldonado A, Smits E, Bogaerts A, Cancers 12, 2782 (2020). http://doi.org/10.3390/cancers12102782
Abstract: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with low five-year survival rates of 8% by conventional treatment methods, e.g., chemotherapy, radiotherapy, and surgery. PDAC shows high resistance towards chemo- and radiotherapy and only 15–20% of all patients can have surgery. This disease is predicted to become the third global leading cause of cancer death due to its significant rise in incidence. Therefore, the development of an alternative or combinational method is necessary to improve current approaches. Cold atmospheric plasma (CAP) treatments could offer multiple advantages to this emerging situation. The plasma-derived reactive species can induce oxidative damage and a cascade of intracellular signaling pathways, which could lead to cell death. Previous reports have shown that CAP treatment also influences cells in the tumor microenvironment, such as the pancreatic stellate cells (PSCs). These PSCs, when activated, play a crucial role in the propagation, growth and survival of PDAC tumors. However, the effect of CAP on PSCs is not yet fully understood. This review focuses on the application of CAP for PDAC treatment and the importance of PSCs in the response to treatment.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
DOI: 10.3390/cancers12102782
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“Combining experimental and modelling approaches to study the sources of reactive species induced in water by the COST RF plasma jet”. Gorbanev Y, Verlackt CCW, Tinck S, Tuenter E, Foubert K, Cos P, Bogaerts A, Physical chemistry, chemical physics 20, 2797 (2018). http://doi.org/10.1039/C7CP07616A
Abstract: The vast biomedical potential of cold atmospheric pressure plasmas (CAPs) is governed by the formation of reactive species. These biologically active species are formed upon the interaction of CAPs with the surroundings. In biological milieu, water plays an essential role. The development of biomedical CAPs thus requires understanding of the sources of the reactive species in aqueous media exposed to the plasma. This is especially important in case of the COST RF plasma jet, which is developed as a reference microplasma system. In this work, we investigated the formation of the OH radicals, H atoms and H2O2 in aqueous solutions exposed to the COST plasma jet. This was done by combining experimental and modelling approaches. The liquid phase species were analysed using UV-Vis spectroscopy and spin trapping with hydrogen isotopes and electron paramagnetic resonance (EPR) spectroscopy. The discrimination between the species formed from the liquid phase and the gas phase molecules was performed by EPR and 1H-NMR analyses of the liquid samples. The concentrations of the reactive species in the gas phase plasma were obtained using a zero-dimensional (0D) chemical kinetics computational model. A three-dimensional (3D) fluid dynamics model was developed to provide information on the induced humidity in the plasma effluent. The comparison of the experimentally obtained trends for the formation of the species as a function of the feed gas and effluent humidity with the modelling results suggest that all reactive species detected in our system are mostly formed in the gas phase plasma inside the COST jet, with minor amounts arising from the plasma effluent humidity.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.123
Times cited: 23
DOI: 10.1039/C7CP07616A
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“Producing oxygen and fertilizer with the Martian atmosphere by using microwave plasma”. Kelly S, Verheyen C, Cowley A, Bogaerts A, Chem 8, 2797 (2022). http://doi.org/10.1016/j.chempr.2022.07.015
Abstract: We explorethepotentialofmicrowave(MW)-plasma-based in situ
utilizationoftheMartianatmospherewithafocusonthenovelpos-
sibilityoffixingN2 forfertilizerproduction. Conversioninasimulant
plasma (i.e., 96% CO2, 2% N2, and 2% Ar),performedunderen-
ergyconditionssimilartothoseoftheMarsOxygen In Situ Resource
UtilizationExperiment(MOXIE),currentlyonboardNASA’sPerse-
verancerover,demonstratesthatO/O2 formedthroughCO2 dissociation
facilitatesthefixationoftheN2 fractionviaoxidationtoNOx.
PromisingproductionratesforO2, CO,andNOx of 47.0,76.1,and
1.25g/h,respectively,arerecordedwithcorrespondingenergy
costs of0.021,0.013,and0.79kWh/g,respectively.Notably,O2
productionratesare 30 timeshigherthanthosedemonstrated
by MOXIE,whiletheNOx production raterepresentsan 7% fixa-
tionoftheN2 fraction presentintheMartian atmosphere.MW-
plasma-basedconversionthereforeshowsgreatpotentialasan in
situ resourceutilization(ISRU)technologyonMarsinthatitsimulta-
neouslyfixesN2 and producesO2.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 23.5
DOI: 10.1016/j.chempr.2022.07.015
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“Towards biolubricant compatible vegetable oils by pore mouth hydrogenation with shape-selective Pt/ZSM-5 catalysts”. Van Aelst J, Philippaerts A, Bartholomeeusen E, Fayad E, Thibault-Starzyk F, Lu J, Schryvers D, Ooms R, Verboekend D, Jacobs P, Sels B, Catalysis science &, technology 6, 2820 (2016). http://doi.org/10.1039/C6CY00498A
Abstract: Pt/ZSM-5 catalysts with various crystal sizes were prepared via competitive ion-exchange, followed by a slow activation procedure. Even when using very large ZSM-5 crystals, highly dispersed Pt nano-clusters were contained within the zeolite crystal's voids, as ascertained by 2D pressure-jump IR spectroscopy of adsorbed CO and focussed ion-beam transmission electron microscopy. The shape-selective properties of the Pt/ZSM-5 catalysts were evaluated in the partial hydrogenation of soybean oil. Unique hydrogenation selectivities were observed, as the fatty acids located at the central position of the triacylglycerol (TAG) molecules were preferentially hydrogenated. The resulting oil has therefore high levels of intermediately melting TAGs, which are compatible with biolubricants due to their improved oxidative stability and still appropriate low-temperature fluidity. The TAG distribution in the partially hydrogenated soybean oil samples was independent from the zeolite crystal size, while the hydrogenation activity linearly increases with the crystal's external surface area. This trend was confirmed with a Pt loaded mesoporous ZSM-5 zeolite, obtained via a mild alkaline treatment. These observations imply and confirm a genuine pore mouth catalysis mechanism, in which only one fatty acid chain of the TAG is able to enter the micropores of ZSM-5, where the double bonds are hydrogenated by the crystal encapsulated Pt-clusters.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.773
Times cited: 5
DOI: 10.1039/C6CY00498A
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“Lipid Oxidation: Role of Membrane Phase-Separated Domains”. Oliveira MC, Yusupov M, Bogaerts A, Cordeiro RM, Journal Of Chemical Information And Modeling 61, 2857 (2021). http://doi.org/10.1021/acs.jcim.1c00104
Abstract: Lipid oxidation is associated with several inflammatory and neurodegenerative diseases, but many questions to unravel its effects on biomembranes are still open due to the complexity of the topic. For instance, recent studies indicated that phase-separated domains can have a significant effect on membrane function. It is reported that domain interfaces are “hot spots” for pore formation, but the underlying mechanisms and the effect of oxidation-induced phase separation on membranes remain elusive. Thus, to evaluate the permeability of the membrane coexisting of liquid-ordered (Lo) and liquid-disordered (Ld) domains, we performed atomistic molecular dynamics simulations. Specifically, we studied the membrane permeability of nonoxidized or oxidized homogeneous membranes (single-phase) and at the Lo/Ld domain interfaces of heterogeneous membranes, where the Ld domain is composed of either oxidized or nonoxidized lipids. Our simulation results reveal that the addition of only 1.5% of lipid aldehyde molecules at the Lo/Ld domain interfaces of heterogeneous membranes increases the membrane permeability, whereas their addition at homogeneous membranes does not have any effect. This study is of interest for a better understanding of cancer treatment methods based on oxidative stress (causing among others lipid oxidation), such as plasma medicine and photodynamic therapy.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 3.76
DOI: 10.1021/acs.jcim.1c00104
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Van Loenhout J, Freire Boullosa L, Quatannens D, De Waele J, Merlin C, Lambrechts H, Lau HW, Hermans C, Lin A, Lardon F, Peeters M, Bogaerts A, Smits E, Deben C (2021) Auranofin and Cold Atmospheric Plasma Synergize to Trigger Distinct Cell Death Mechanisms and Immunogenic Responses in Glioblastoma. 2936
Abstract: Targeting the redox balance of malignant cells via the delivery of high oxidative stress unlocks a potential therapeutic strategy against glioblastoma (GBM). We investigated a novel reactive oxygen species (ROS)-inducing combination treatment strategy, by increasing exogenous ROS via cold atmospheric plasma and inhibiting the endogenous protective antioxidant system via auranofin (AF), a thioredoxin reductase 1 (TrxR) inhibitor. The sequential combination treatment of AF and cold atmospheric plasma-treated PBS (pPBS), or AF and direct plasma application, resulted in a synergistic response in 2D and 3D GBM cell cultures, respectively. Differences in the baseline protein levels related to the antioxidant systems explained the cell-line-dependent sensitivity towards the combination treatment. The highest decrease of TrxR activity and GSH levels was observed after combination treatment of AF and pPBS when compared to AF and pPBS monotherapies. This combination also led to the highest accumulation of intracellular ROS. We confirmed a ROS-mediated response to the combination of AF and pPBS, which was able to induce distinct cell death mechanisms. On the one hand, an increase in caspase-3/7 activity, with an increase in the proportion of annexin V positive cells, indicates the induction of apoptosis in the GBM cells. On the other hand, lipid peroxidation and inhibition of cell death through an iron chelator suggest the involvement of ferroptosis in the GBM cell lines. Both cell death mechanisms induced by the combination of AF and pPBS resulted in a significant increase in danger signals (ecto-calreticulin, ATP and HMGB1) and dendritic cell maturation, indicating a potential increase in immunogenicity, although the phagocytotic capacity of dendritic cells was inhibited by AF. In vivo, sequential combination treatment of AF and cold atmospheric plasma both reduced tumor growth kinetics and prolonged survival in GBM-bearing mice. Thus, our study provides a novel therapeutic strategy for GBM to enhance the efficacy of oxidative stress-inducing therapy through a combination of AF and cold atmospheric plasma.
Keywords: A1 Journal Article;oxidative stress; auranofin; cold atmospheric plasma; glioblastoma; cancer cell death; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
DOI: 10.3390/cells10112936
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“Plasma-Catalytic Partial Oxidation of Methane on Pt(111): A Microkinetic Study on the Role of Different Plasma Species”. Loenders B, Engelmann Y, Bogaerts A, Journal Of Physical Chemistry C 125, 2966 (2021). http://doi.org/10.1021/acs.jpcc.0c09849
Abstract: We use microkinetic modeling to examine the potential of plasma-catalytic partial oxidation (POX) of CH4 as a promising new approach to produce oxygenates. We study how different plasma species affect POX of CH4 on the Pt(111) surface, and we discuss the associated kinetic and mechanistic changes. We discuss the effect of vibrationally excited CH4 and O2, as well as plasma-generated radicals and stable intermediates. Our results show that vibrational excitation enhances the turnover frequency (TOF) of catalytic CH4 dissociation and has good potential for improving the selectivities toward CH3OH, HCOOH, and C2 hydrocarbons. Nevertheless, when also considering plasma-generated radicals, we find that these species mainly govern the surface chemistry. Additionally, we find that plasma-generated radicals and stable intermediates enhance the TOFs of COx and oxygenates, increase the selectivity toward oxygenates, and make the formation of HCOOH more significant on Pt(111). We also briefly illustrate the potential impact of Eley−Rideal reactions that involve plasma-generated radicals. Finally, we reveal how various radicals affect the catalyst surface chemistry and we link this to the formation of different products. This allows us to make suggestions on how the plasma composition should be altered to improve the formation of desired products.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Movement Antwerp (MOVANT)
Impact Factor: 4.536
DOI: 10.1021/acs.jpcc.0c09849
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“Modeling of ionization of argon in an analytical capacitively coupled radio-frequency glow discharge”. Bogaerts A, Yan M, Gijbels R, Goedheer W, Journal of applied physics 86, 2990 (1999). http://doi.org/10.1063/1.371159
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.068
Times cited: 18
DOI: 10.1063/1.371159
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“Nitrogen fixation with water vapor by nonequilibrium plasma : toward sustainable ammonia production”. Gorbanev Y, Vervloessem E, Nikiforov A, Bogaerts A, Acs Sustainable Chemistry &, Engineering 8, 2996 (2020). http://doi.org/10.1021/ACSSUSCHEMENG.9B07849
Abstract: Ammonia is a crucial nutrient used for plant growth and as a building block in the pharmaceutical and chemical industry, produced via nitrogen fixation of the ubiquitous atmospheric N2. Current industrial ammonia production relies heavily on fossil resources, but a lot of work is put into developing nonfossil-based pathways. Among these is the use of nonequilibrium plasma. In this work, we investigated water vapor as a H source for nitrogen fixation into NH3 by nonequilibrium plasma. The highest selectivity toward NH3 was observed with low amounts of added H2O vapor, but the highest production rate was reached at high H2O vapor contents. We also studied the role of H2O vapor and of the plasma-exposed liquid H2O in nitrogen fixation by using isotopically labeled water to distinguish between these two sources of H2O. We show that added H2O vapor, and not liquid H2O, is the main source of H for NH3 generation. The studied catalyst- and H2-free method offers excellent selectivity toward NH3 (up to 96%), with energy consumption (ca. 95–118 MJ/mol) in the range of many plasma-catalytic H2-utilizing processes.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 8.4
Times cited: 14
DOI: 10.1021/ACSSUSCHEMENG.9B07849
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“Insights into the growth of (ultra)nanocrystalline diamond by combined molecular dynamics and Monte Carlo simulations”. Eckert M, Neyts E, Bogaerts A, Crystal growth &, design 10, 3005 (2010). http://doi.org/10.1021/cg100063c
Abstract: In this paper, we present the results of combined molecular dynamics−Metropolis Monte Carlo (MD-MMC) simulations of hydrocarbon species at flat diamond (100)2 × 1 and (111)1 × 1 surfaces. The investigated species are considered to be the most important growth species for (ultra)nanocrystalline diamond ((U)NCD) growth. When applying the MMC algorithm to stuck species at monoradical sites, bonding changes are only seen for CH2. The sequence of the bond breaking and formation as put forward by the MMC simulations mimics the insertion of CH2 into a surface dimer as proposed in the standard growth model of diamond. For hydrocarbon species attached to two adjacent radical (biradical) sites, the MMC simulations give rise to significant changes in the bonding structure. For UNCD, the combinations of C3 and C3H2, and C3 and C4H2 (at diamond (100)2 × 1) and C and C2H2 (at diamond (111)1 × 1) are the most successful in nucleating new crystal layers. For NCD, the following combinations pursue the diamond structure the best: C2H2 and C3H2 (at diamond (100)2 × 1) and CH2 and C2H2 (at diamond (111)1 × 1). The different behaviors of the hydrocarbon species at the two diamond surfaces are related to the different sterical hindrances at the diamond surfaces.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.055
Times cited: 13
DOI: 10.1021/cg100063c
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“Nitrogen fixation in an electrode-free microwave plasma”. Kelly S, Bogaerts A, Joule 5, 3006 (2021). http://doi.org/10.1016/j.joule.2021.09.009
Abstract: Plasma-based gas conversion has great potential for enabling carbon-free fertilizer production powered by renewable electricity. Sustaining an energy-efficient plasma process without eroding the containment vessel is currently a significant challenge, limiting scaling to higher powers and throughputs. Isolation of the plasma from contact with any solid surfaces is an advantage, which both limits energy loss to the walls and prevents material erosion that could lead to disastrous soil contamination. This paper presents highly energy-efficient nitrogen fixation from air into NOx by microwave plasma, with the plasma filament isolated at the center of a quartz tube using a vortex gas flow. NOx production is found to scale very efficiently when increasing both gas flow rate and absorbed power. The lowest energy cost recorded of ~2 MJ/mol, for a total NOx production of ~3.8%, is the lowest reported up to now for atmospheric pressure plasmas.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
DOI: 10.1016/j.joule.2021.09.009
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“Incorporating the gas flow in a numerical model of rf discharges in methane”. Okhrimovskyy A, Bogaerts A, Gijbels R, Journal of applied physics 96, 3070 (2004). http://doi.org/10.1063/1.1782951
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.068
Times cited: 11
DOI: 10.1063/1.1782951
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“Advances in Plasma Oncology toward Clinical Translation”. Lin A, Stapelmann K, Bogaerts A, Cancers 12, 3283 (2020). http://doi.org/10.3390/cancers12113283
Abstract: This Special Issue on “Advances in Plasma Oncology Toward Clinical Translation” aims to bring together cutting-edge research papers within the field in the context of clinical translation and application [...]
Keywords: Editorial; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
DOI: 10.3390/cancers12113283
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“Atomic spectroscopy”. Bings NH, Bogaerts A, Broekaert JAC, Analytical chemistry 76, 3313 (2004). http://doi.org/10.1021/ac040052x
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.32
Times cited: 32
DOI: 10.1021/ac040052x
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“Possible Synergies of Nanomaterial-Assisted Tissue Regeneration in Plasma Medicine: Mechanisms and Safety Concerns”. Shaw P, Vanraes P, Kumar N, Bogaerts A, Nanomaterials 12, 3397 (2022). http://doi.org/10.3390/nano12193397
Abstract: Cold atmospheric plasma and nanomedicine originally emerged as individual domains, but are increasingly applied in combination with each other. Most research is performed in the context of cancer treatment, with only little focus yet on the possible synergies. Many questions remain on the potential of this promising hybrid technology, particularly regarding regenerative medicine and tissue engineering. In this perspective article, we therefore start from the fundamental mechanisms in the individual technologies, in order to envision possible synergies for wound healing and tissue recovery, as well as research strategies to discover and optimize them. Among these strategies, we demonstrate how cold plasmas and nanomaterials can enhance each other’s strengths and overcome each other’s limitations. The parallels with cancer research, biotechnology and plasma surface modification further serve as inspiration for the envisioned synergies in tissue regeneration. The discovery and optimization of synergies may also be realized based on a profound understanding of the underlying redox- and field-related biological processes. Finally, we emphasize the toxicity concerns in plasma and nanomedicine, which may be partly remediated by their combination, but also partly amplified. A widespread use of standardized protocols and materials is therefore strongly recommended, to ensure both a fast and safe clinical implementation.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 5.3
DOI: 10.3390/nano12193397
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“Physical Plasma-Treated Skin Cancer Cells Amplify Tumor Cytotoxicity of Human Natural Killer (NK) Cells”. Clemen R, Heirman P, Lin A, Bogaerts A, Bekeschus S, Cancers 12, 3575 (2020). http://doi.org/10.3390/cancers12123575
Abstract: Skin cancers have the highest prevalence of all human cancers, with the most lethal forms being squamous cell carcinoma and malignant melanoma. Besides the conventional local treatment approaches like surgery and radiotherapy, cold physical plasmas are emerging anticancer tools. Plasma technology is used as a therapeutic agent by generating reactive oxygen species (ROS). Evidence shows that inflammation and adaptive immunity are involved in cancer-reducing effects of plasma treatment, but the role of innate immune cells is still unclear. Natural killer (NK)-cells interact with target cells via activating and inhibiting surface receptors and kill in case of dominating activating signals. In this study, we investigated the effect of cold physical plasma (kINPen) on two skin cancer cell lines (A375 and A431), with non-malignant HaCaT keratinocytes as control, and identified a plasma treatment time-dependent toxicity that was more pronounced in the cancer cells. Plasma treatment also modulated the expression of activating and inhibiting receptors more profoundly in skin cancer cells compared to HaCaT cells, leading to significantly higher NK-cell killing rates in the tumor cells. Together with increased pro-inflammatory mediators such as IL-6 and IL-8, we conclude that plasma treatment spurs stress responses in skin cancer cells, eventually augmenting NK-cell activity.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
DOI: 10.3390/cancers12123575
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“Spatial behavior of energy relaxation of electrons in capacitively coupled discharges: comparison between Ar and SiH4”. Yan M, Bogaerts A, Gijbels R, Goedheer WJ, Journal of applied physics 87, 3628 (2000). http://doi.org/10.1063/1.372392
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.068
Times cited: 14
DOI: 10.1063/1.372392
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“Modeling of metastable argon atoms in a direct current glow discharge”. Bogaerts A, Gijbels R, Physical review : A : atomic, molecular and optical physics 52, 3743 (1995). http://doi.org/10.1103/PhysRevA.52.3743
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.808
Times cited: 98
DOI: 10.1103/PhysRevA.52.3743
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