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Author Jannis, D.
Title Novel detection schemes for transmission electron microscopy Type Doctoral thesis
Year 2021 Publication Abbreviated Journal
Volume Issue Pages iv, 208 p.
Keywords Doctoral thesis; Electron microscopy for materials research (EMAT)
Abstract (down) Electron microscopy is an excellent tool which provides resolution down to the atomic scale with up to pm precision in locating atoms. The characterization of materials in these length scales is of utmost importance to answer questions in biology, chemistry and material science. The successful implementation of aberration-corrected microscopes made atomic resolution imaging relatively easy, this could give the impression that the development of novel electron microscopy techniques would stagnate and only the application of these instruments as giant magnifying tools would continue. This is of course not true and a multitude of problems still exist in electron microscopy. Two of such issues are discussed below. One of the biggest problems in electron microscopy is the presence of beam damage which occurs due the fact that the highly energetic incoming electrons have sufficient kinetic energy to change the structure of the material. The amount of damage induced depends on the dose, hence minimizing this dose during an experiment is beneficial. This minimizing of the total dose comes at the expense of more noise due to the counting nature of the electrons. For this reason, the implementation of four dimensional scanning transmission electron microscopy (4D STEM) experiments has reduced the total dose needed per acquisition. However, the current cameras used to measure the diffraction patterns are still two orders of magnitude slower than to the conventional STEM methods. Improving the acquisition speed would make the 4D STEM technique more feasible and is of utmost importance for the beam sensitive materials since less dose is used during the acquisition. In TEM there is not only the possibility to perform imaging experiments but also spectroscopic measurements. There are two frequently used methods: electron energy-loss spectroscopy (EELS) and energy dispersive x-ray spectroscopy (EDX). EELS measures the energy-loss spectrum of the incoming electron which gives information on the available excitations in the material providing elemental sensitivity. In EDX, the characteristic x-rays, arising from the decay of an atom which is initially excited due to the incoming electrons, are detected providing similar elemental analysis. Both methods are able to provide comparable elemental information where in certain circumstances one outperforms the other. However, both methods have a detection limit of approximately 100-1000 ppm which is not sufficient for some materials. In this thesis, two novel techniques which can make significant progress for the two problems discussed above.
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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:182404 Serial 6872
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Author Schram, J.; Thiruvottriyur Shanmugam, S.; Sleegers, N.; Florea, A.; Samyn, N.; van Nuijs, A.L.N.; De Wael, K.
Title Local conversion of redox inactive molecules into redox active ones : a formaldehyde based strategy for the electrochemical detection of illicit drugs containing primary and secondary amines Type A1 Journal article
Year 2021 Publication Electrochimica Acta Abbreviated Journal Electrochim Acta
Volume 367 Issue Pages 137515
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre
Abstract (down) Electrochemical techniques have evidenced to be highly suitable for the development of portable, rapid and accurate screening methods for the detection of illicit drugs in seized samples. However, the redox inactivity of primary amines, one of the most common functional groups of illicit drugs, masks voltammetric detection in aqueous environment at carbon electrodes and, therefore, leads to false negative results if only these primary amines are present in the structures. This work explores the feasibility of a derivatisation approach that introduces formaldehyde in the measuring conditions in order to achieve methylation, via an Eschweiler-Clarke mechanism, of illicit drugs containing primary and secondary amines, using amphetamine (AMP) and methamphetamine (MET) as model molecules. As a result the electrochemical fingerprint is enriched and thereby the detectability enhanced. A combination of liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOFMS) and square-wave voltammetric (SWV) measurements is employed to identify reaction products and link them to the observed redox peaks. Although an alkaline environment (pH 12.0) proved to increase the reaction yield, a richer electrochemical fingerprint (EF) is obtained in neutral conditions (pH 7.0). Similarly, the addition of formate improved the reaction conversion but reduced the EF by eliminating a redox peak that is attributed to side products formed in the absence of formate. To illustrate the applicability, the derivatisation strategy is applied to several prominent illicit drugs containing primary and secondary amines to demonstrate its EF enriching capabilities. Finally, real street samples from forensic seizures are analysed. Overall, this strategy unlocks the detectability of the hitherto undetectable AMP and other drugs only containing primary amines, while strongly facilitating the identification of MET and analogues. These findings are not limited to illicit drugs, the insights can ultimately be applied to other target molecules containing similar functional groups. (C) 2020 Published by Elsevier Ltd.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000607620700010 Publication Date 2020-11-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-4686 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.798 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 4.798
Call Number UA @ admin @ c:irua:176083 Serial 8177
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Author Karaaslan, Y.; Haskins, J.B.; Yapicioglu, H.; Sevik, C.
Title Influence of randomly distributed vacancy defects on thermal transport in two-dimensional group-III nitrides Type A1 Journal article
Year 2021 Publication Journal Of Applied Physics Abbreviated Journal J Appl Phys
Volume 129 Issue 22 Pages 224304
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (down) Efficient thermal transport control is a fundamental issue for electronic device applications such as information, communication, and energy storage technologies in modern electronics in order to achieve desired thermal conditions. Structural defects in materials provide a mechanism to adjust the thermal transport properties of these materials on demand. In this context, the effect of structural defects on lattice thermal conductivities of two-dimensional hexagonal binary group-III nitride (XN, X = B, Al, and Ga) semiconductors is systematically investigated by means of classical molecular dynamics simulations performed with recently developed transferable inter-atomic potentials accurately describing defect energies. Here, two different Green-Kubo based approaches and another approach based on non-equilibrium molecular dynamics are compared in order to get an overall understanding. Our investigation clearly shows that defect concentrations of 3% decrease the thermal conductivity of systems containing these nitrites up to 95%. Results hint that structural defects can be used as effective adjustment parameters in controlling thermal transport properties in device applications associated with these materials. Published under an exclusive license by AIP Publishing.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000692024300001 Publication Date 2021-06-09
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 2.068 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 2.068
Call Number UA @ admin @ c:irua:181618 Serial 8096
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Author Dillen, A.; Vandezande, W.; Daems, D.; Lammertyn, J.
Title Unraveling the effect of the aptamer complementary element on the performance of duplexed aptamers : a thermodynamic study Type A1 Journal article
Year 2021 Publication Analytical And Bioanalytical Chemistry Abbreviated Journal Anal Bioanal Chem
Volume 413 Issue 19 Pages 4739-4750
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (down) Duplexed aptamers (DAs) are widespread aptasensor formats that simultaneously recognize and signal the concentration of target molecules. They are composed of an aptamer and aptamer complementary element (ACE) which consists of a short oligonucleotide that partially inhibits the aptamer sequence. Although the design principles to engineer DAs are straightforward, the tailored development of DAs for a particular target is currently based on trial and error due to limited knowledge of how the ACE sequence affects the final performance of DA biosensors. Therefore, we have established a thermodynamic model describing the influence of the ACE on the performance of DAs applied in equilibrium assays and demonstrated that this relationship can be described by the binding strength between the aptamer and ACE. To validate our theoretical findings, the model was applied to the 29-mer anti-thrombin aptamer as a case study, and an experimental relation between the aptamer-ACE binding strength and performance of DAs was established. The obtained results indicated that our proposed model could accurately describe the effect of the ACE sequence on the performance of the established DAs for thrombin detection, applied for equilibrium assays. Furthermore, to characterize the binding strength between the aptamer and ACEs evaluated in this work, a set of fitting equations was derived which enables thermodynamic characterization of DNA-based interactions through thermal denaturation experiments, thereby overcoming the limitations of current predictive software and chemical denaturation experiments. Altogether, this work encourages the development, characterization, and use of DAs in the field of biosensing.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000659366300001 Publication Date 2021-06-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1618-2642; 1618-2650 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.431 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 3.431
Call Number UA @ admin @ c:irua:179163 Serial 8713
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Author Chen, X.; Li, L.; Peeters, F.M.; Sanyal, B.
Title Two-dimensional oxygen functionalized honeycomb and zigzag dumbbell silicene with robust Dirac cones Type A1 Journal article
Year 2021 Publication New Journal Of Physics Abbreviated Journal New J Phys
Volume 23 Issue 2 Pages 023007
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (down) Dumbbell-like structures are recently found to be energetically favored in group IV two-dimensional (2D) materials, exhibiting rich physics and many interesting properties. In this paper, using first-principles calculations, we have investigated the oxidized form of the hexagonal honeycomb (ODB-h) and zigzag dumbbell silicene (ODB-z). We confirm that both oxidization processes are energetically favorable, and their phonon spectra further demonstrate the dynamic stability. Contrary to the pristine dumbbell silicene structures (PDB-h and PDB-z silicene), these oxidized products ODB-h and ODB-z silicene are both semimetals with Dirac cones at the Fermi level. The Dirac cones of ODB-h and ODB-z silicene are at the K point and between Y and Gamma points respectively, possessing high Fermi velocities of 3.1 x 10(5) m s(-1) (ODB-h) and 2.9-3.4 x 10(5) m s(-1) (ODB-z). The origin of the Dirac cones is further explained by tight-binding models. The semimetallic properties of ODB-h and ODB-z are sensitive to compression due to the self-absorption effect, but quite robust against the tensile strain. These outstanding properties make oxidized dumbbell silicene a promising material for quantum computing and high-speed electronic devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000616114900001 Publication Date 2021-01-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1367-2630 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.786 Times cited 2 Open Access OpenAccess
Notes Approved Most recent IF: 3.786
Call Number UA @ admin @ c:irua:176575 Serial 6741
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Author Wang, Q.; Lin, S.; Liu, X.; Xu, W.; Xiao, Y.; Liang, C.; Ding, L.; Peeters, F.M.
Title Photoluminescence and electronic transition behaviors of single-stranded DNA Type A1 Journal article
Year 2021 Publication Physical Review E Abbreviated Journal Phys Rev E
Volume 104 Issue 3 Pages 034412
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (down) Due to the potential application of DNA for biophysics and optoelectronics, the electronic energy states and transitions of this genetic material have attracted a great deal of attention recently. However, the fluorescence and corresponding physical process of DNA under optical excitation with photon energies below ultraviolet are still not fully clear. In this work, we experimentally investigate the photoluminescence (PL) properties of single-stranded DNA (ssDNA) samples under near-ultraviolet (NUV) and visible excitations (270 similar to 440 nm). Based on the dependence of the PL peak wavelength (lem) upon the excitation wavelength (lex), the PL behaviors of ssDNA can be approximately classified into two categories. In the relatively short excitation wavelength regime, lem is nearly constant due to exciton-like transitions associated with delocalized excitonic states and excimer states. In the relatively long excitation wavelength range, a linear relation of lem = Alex + B with A 0 or A < 0 can be observed, which comes from electronic transitions related to coupled vibrational-electronic levels. Moreover, the transition channels in different excitation wavelength regimes and the effects of strand length and base type can be analyzed on the basis of these results. These important findings not only can give a general description of the electronic energy states and transitional behaviors of ssDNA samples under NUV and visible excitations, but also can be the basis for the application of DNA in nanoelectronics and optoelectronics.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000703562300002 Publication Date 2021-09-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0053 ISBN Additional Links UA library record; WoS full record
Impact Factor 2.366 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 2.366
Call Number UA @ admin @ c:irua:182517 Serial 7009
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Author Herzog, M.J.; Gauquelin, N.; Esken, D.; Verbeeck, J.; Janek, J.
Title Increased Performance Improvement of Lithium-Ion Batteries by Dry Powder Coating of High-Nickel NMC with Nanostructured Fumed Ternary Lithium Metal Oxides Type A1 Journal article
Year 2021 Publication ACS applied energy materials Abbreviated Journal ACS Appl. Energy Mater.
Volume 4 Issue 9 Pages 8832-8848
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (down) Dry powder coating is an effective approach to protect the surfaces of layered cathode active materials (CAMs) in lithium-ion batteries. Previous investigations indicate an incorporation of lithium ions in fumed Al2O3, ZrO2, and TiO2 coatings on LiNi0.7Mn0.15Co0.15O2 during cycling, improving the cycling performance. Here, this coating approach is transferred for the first time to fumed ternary LiAlO2, Li4Zr3O8, and Li4Ti5O12 and directly compared with their lithium-free equivalents. All materials could be processed equally and their nanostructured small aggregates accumulate on the CAM surfaces to quite homogeneous coating layers with a certain porosity. The LiNixMnyCozO2 (NMC) coated with lithium-containing materials shows an enhanced improvement in overall capacity, capacity retention, rate performance, and polarization behavior during cycling, compared to their lithium-free analogues. The highest rate performance was achieved with the fumed ZrO2 coating, while the best long-term cycling stability with the highest absolute capacity was obtained for the fumed LiAlO2-coated NMC. The optimal coating agent for NMC to achieve a balanced system is fumed Li4Ti5O12, providing a good compromise between high rate capability and good capacity retention. The coating agents prevent CAM particle cracking and degradation in the order LiAlO2 ≈ Al2O3 > Li4Ti5O12 > Li4Zr3O8 > ZrO2 > TiO2. A schematic model for the protection and electrochemical performance enhancement of high-nickel NMC with fumed metal oxide coatings is sketched. It becomes apparent that physical and chemical characteristics of the coating significantly influence the performance of NMC. A high degree of coating-layer porosity is favorable for the rate capability, while a high coverage of the surface, especially in vulnerable grain boundaries, enhances the long-term cycling stability and improves the cracking behavior of NMCs. While zirconium-containing coatings possess the best chemical properties for high rate performances, aluminum-containing coatings feature a superior chemical nature to protect high-nickel NMCs.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000703338600018 Publication Date 2021-09-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2574-0962 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 15 Open Access OpenAccess
Notes For his support in scanning electron microscopy analysis, the authors thank Erik Peldszus. N. G. and J. V. acknowledge funding from GOA project “Solarpaint” of the University of Antwerp and from the Flemish Research Fund (FWO) project G0F1320N. The Qu-Ant-EM microscope and the direct electron detector were partly funded by the Hercules fund from the Flemish Government Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:183949 Serial 6823
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Author Sharafi, L.; Zarafshani, K.; Keshavarz, M.; Azadi, H.; Van Passel, S.
Title Farmers' decision to use drought early warning system in developing countries Type A1 Journal article
Year 2021 Publication Science Of The Total Environment Abbreviated Journal Sci Total Environ
Volume 758 Issue Pages 142761
Keywords A1 Journal article; Engineering Management (ENM)
Abstract (down) Drought is a persistent, sluggish natural disaster in developing countries that has generated a financial burden and an unstable climate. Farmers should adopt early warning systems (EWS) in their strategies for monitoring drought to reduce its serious consequences. However, farmers in developing countries are reluctant to use EWS as their management strategies. Hence, the aim of this study was to investigate the decision of farmers to use climate knowledge through the model of farming activity in Kermanshah Township, Iran. A surveyor questionnaire was used to gather data from 370 wheat farmers using random sampling methods inmulti-stage clusters. Results revealed that the decision to use climate information is affected by personal factors, attitude towards climate information, objectives of using climate information, and external/physical farming factors. The result of this study has implications for drought management practitioners. To be specific, the results can aid policymakers to design early alert programs to minimize the risk of drought and thus move from conventional to climate smart agriculture. (C) 2020 Elsevier B.V. All rights reserved.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000605623800001 Publication Date 2020-10-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0048-9697 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.9 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.9
Call Number UA @ admin @ c:irua:176030 Serial 6924
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Author Dingenen, F.; Verbruggen, S.W.
Title Tapping hydrogen fuel from the ocean : a review on photocatalytic, photoelectrochemical and electrolytic splitting of seawater Type A1 Journal article
Year 2021 Publication Renewable & Sustainable Energy Reviews Abbreviated Journal Renew Sust Energ Rev
Volume 142 Issue Pages 110866
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) Direct splitting of earth-abundant seawater provides an eco-friendly route for the production of clean H2, but is hampered by selectivity and stability issues. Direct seawater electrolysis is the most established technology, attaining high current densities in the order of 1–2 A cm−2. Alternatively, light-driven processes such as photocatalytic and photoelectrochemical seawater splitting are particularly promising as well, as they rely on renewable solar power. Solar-to-Hydrogen efficiencies have increased over the past decade from negligible values to about 2%. Especially the absence of large local pH changes (in the order of several tenths of a pH unit compared to up to 9 pH units for electrolysis) is a strong asset for pure photocatalysis. This may lead to less adverse side-reactions such as Cl2 and ClO− formation, (acid or base induced) corrosion and scaling. Besides, additional requirements for electrolytic cells, e.g. membranes and electricity input, are not needed in pure photocatalysis systems. In this review, the state-of-the-art technologies in light-driven seawater splitting are compared to electrochemical approaches with a focus on sustainability and stability. Promising advances are identified at the level of the catalyst as well as the process, and insight is provided in solutions crossing different fields.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000632316600003 Publication Date 2021-03-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1364-0321; 1879-0690 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.05 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 8.05
Call Number UA @ admin @ c:irua:175701 Serial 8642
Permanent link to this record
 
 
Author Li, S.; Ahmed, R.; Yi, Y.; Bogaerts, A.
Title Methane to Methanol through Heterogeneous Catalysis and Plasma Catalysis Type A1 Journal article
Year 2021 Publication Catalysts Abbreviated Journal Catalysts
Volume 11 Issue 5 Pages 590
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (down) Direct oxidation of methane to methanol (DOMTM) is attractive for the increasing industrial demand of feedstock. In this review, the latest advances in heterogeneous catalysis and plasma catalysis for DOMTM are summarized, with the aim to pinpoint the differences between both, and to provide some insights into their reaction mechanisms, as well as the implications for future development of highly selective catalysts for DOMTM.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000653609900001 Publication Date 2021-05-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-4344 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.082 Times cited Open Access OpenAccess
Notes Fundamental Research Funds for the Central Universities of China, DUT18JC42 ; National Natural Science Foundation of China, 21503032 ; PetroChina Innovation Foundation, 2018D-5007-0501 ; TOP-BOF research project of the Research Council of the University of Antwerp, 32249 ; This research was funded by the Fundamental Research Funds for the Central Universities of China (DUT18JC42), the National Natural Science Foundation of China (21503032) PetroChina Innovation Foundation (2018D-5007-0501) and the TOP-BOF research project of the Research Council of the University of Antwerp (grant ID 32249). This research was supported by the China Scholarship Council (CSC). The authors warmly acknowledge CSC for their support. Approved Most recent IF: 3.082
Call Number PLASMANT @ plasmant @c:irua:177851 Serial 6753
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Author Demiroglu, I.; Karaaslan, Y.; Kocabas, T.; Keceli, M.; Vazquez-Mayagoitia, A.; Sevik, C.
Title Computation of the thermal expansion coefficient of graphene with Gaussian approximation potentials Type A1 Journal article
Year 2021 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C
Volume 125 Issue 26 Pages 14409-14415
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract (down) Direct experimental measurement of thermal expansion coefficient without substrate effects is a challenging task for two-dimensional (2D) materials, and its accurate estimation with large-scale ab initio molecular dynamics is computationally very expensive. Machine learning-based interatomic potentials trained with ab initio data have been successfully used in molecular dynamics simulations to decrease the computational cost without compromising the accuracy. In this study, we investigated using Gaussian approximation potentials to reproduce the density functional theory-level accuracy for graphene within both lattice dynamical and molecular dynamical methods, and to extend their applicability to larger length and time scales. Two such potentials are considered, GAP17 and GAP20. GAP17, which was trained with pristine graphene structures, is found to give closer results to density functional theory calculations at different scales. Further vibrational and structural analyses verify that the same conclusions can be deduced with density functional theory level in terms of the reasoning of the thermal expansion behavior, and the negative thermal expansion behavior is associated with long-range out-of-plane phonon vibrations. Thus, it is argued that the enabled larger system sizes by machine learning potentials may even enhance the accuracy compared to small-size-limited ab initio molecular dynamics.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000672734100027 Publication Date 2021-06-24
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 Open Access OpenAccess
Notes Approved Most recent IF: 4.536
Call Number UA @ admin @ c:irua:179850 Serial 7719
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Author Lavor, I.R.; Chaves, A.; Peeters, F.M.; Van Duppen, B.
Title Tunable coupling of terahertz Dirac plasmons and phonons in transition metal dichalcogenide-based van der Waals heterostructures Type A1 Journal article
Year 2021 Publication 2d Materials Abbreviated Journal 2D Mater
Volume Issue Pages 015018
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (down) Dirac plasmons in graphene hybridize with phonons of transition metal dichalcogenides (TMDs) when the materials are combined in so-called van der Waals heterostructures (vdWh), thus forming surface plasmon-phonon polaritons (SPPPs). The extend to which these modes are coupled depends on the TMD composition and structure, but also on the plasmons' properties. By performing realistic simulations that account for the contribution of each layer of the vdWh separately, we calculate how the strength of plasmon-phonon coupling depends on the number and composition of TMD layers, on the graphene Fermi energy and the specific phonon mode. From this, we present a semiclassical theory that is capable of capturing all relevant characteristics of the SPPPs. We find that it is possible to realize both strong and ultra-strong coupling regimes by tuning graphene's Fermi energy and changing TMD layer number.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000722020100001 Publication Date 2021-11-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record
Impact Factor 6.937 Times cited 1 Open Access OpenAccess
Notes Approved Most recent IF: 6.937
Call Number UA @ admin @ c:irua:183053 Serial 7036
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Author Lavor, I.R.; Cavalcante, L.S.R.; Chaves, A.; Peeters, F.M.; Van Duppen, B.
Title Probing the structure and composition of van der Waals heterostructures using the nonlocality of Dirac plasmons in the terahertz regime Type A1 Journal article
Year 2021 Publication 2d Materials Abbreviated Journal 2D Mater
Volume 8 Issue 1 Pages 015014
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (down) Dirac plasmons in graphene are very sensitive to the dielectric properties of the environment. We show that this can be used to probe the structure and composition of van der Waals heterostructures (vdWh) put underneath a single graphene layer. In order to do so, we assess vdWh composed of hexagonal boron nitride and different types of transition metal dichalcogenides (TMDs). By performing realistic simulations that account for the contribution of each layer of the vdWh separately and including the importance of the substrate phonons, we show that one can achieve single-layer resolution by investigating the nonlocal nature of the Dirac plasmon-polaritons. The composition of the vdWh stack can be inferred from the plasmon-phonon coupling once it is composed by more than two TMD layers. Furthermore, we show that the bulk character of TMD stacks for plasmonic screening properties in the terahertz regime is reached only beyond 100 layers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000582820500001 Publication Date 2020-10-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited 4 Open Access OpenAccess
Notes ; This work was financially supported by the Brazilian Council for Research (CNPq), Brazilian National Council for the Improvement of Higher Education (CAPES) and by the Research Foundation Flanders (FWO) through a postdoctoral fellowship to B.V.D. ; Approved Most recent IF: 6.937
Call Number UA @ admin @ c:irua:173507 Serial 6696
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Author Tao, Z.H.; Dong, H.M.; Milošević, M.V.; Peeters, F.M.; Van Duppen, B.
Title Tailoring dirac plasmons via anisotropic dielectric environment by design Type A1 Journal article
Year 2021 Publication Physical Review Applied Abbreviated Journal Phys Rev Appl
Volume 16 Issue 5 Pages 054030
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (down) Dirac plasmons in a two-dimensional (2D) crystal are strongly affected by the dielectric properties of the environment, due to interaction of their electric field lines with the surrounding medium. Using graphene as a 2D reservoir of free carriers, one can engineer a material configuration that provides an anisotropic environment to the plasmons. In this work, we discuss the physical properties of Dirac plasmons in graphene surrounded by an arbitrary anisotropic dielectric and exemplify how h-BN-based heterostructures can be designed to bear the required anisotropic characteristics. We calculate how dielec-tric anisotropy impacts the spatial propagation of the plasmons and find that an anisotropy-induced plasmon mode emerges, together with a damping pathway, that stem from the out-of-plane off-diagonal elements in the dielectric tensor. Furthermore, we find that one can create hyperbolic plasmons by inher-iting the dielectric hyperbolicity of the designed material environment. Strong control over plasmon propagation patterns can be realized in a similar manner. Finally, we show that in this way one can also control the polarization of the light-matter excitations that constitute the plasmon. Taken together, our results promote the design of the dielectric environment as an effective path to tailor the plasmonic response of graphene on the nanoscopic level.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000720372500002 Publication Date 2021-11-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2331-7019 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.808 Times cited 2 Open Access Not_Open_Access
Notes Approved Most recent IF: 4.808
Call Number UA @ admin @ c:irua:184063 Serial 7028
Permanent link to this record
 
 
Author Hamid, I.; Jalali, H.; Peeters, F.M.; Neek-Amal, M.
Title Abnormal in-plane permittivity and ferroelectricity of confined water : from sub-nanometer channels to bulk Type A1 Journal article
Year 2021 Publication Journal Of Chemical Physics Abbreviated Journal J Chem Phys
Volume 154 Issue 11 Pages 114503
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (down) Dielectric properties of nano-confined water are important in several areas of science, i.e., it is relevant in the dielectric double layer that exists in practically all heterogeneous fluid-based systems. Molecular dynamics simulations are used to predict the in-plane dielectric properties of confined water in planar channels of width ranging from sub-nanometer to bulk. Because of suppressed rotational degrees of freedom near the confining walls, the dipole of the water molecules tends to be aligned parallel to the walls, which results in a strongly enhanced in-plane dielectric constant (epsilon (parallel to)) reaching values of about 120 for channels with height 8 angstrom < h < 10 angstrom. With the increase in the width of the channel, we predict that epsilon (parallel to) decreases nonlinearly and reaches the bulk value for h > 70 angstrom. A stratified continuum model is proposed that reproduces the h > 10 angstrom dependence of epsilon (parallel to). For sub-nanometer height channels, abnormal behavior of epsilon (parallel to) is found with two orders of magnitude reduction of epsilon (parallel to) around h similar to 7.5 angstrom, which is attributed to the formation of a particular ice phase that exhibits long-time (similar to mu s) stable ferroelectricity. This is of particular importance for the understanding of the influence of confined water on the functioning of biological systems.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000629831900001 Publication Date 2021-03-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-9606 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.965 Times cited 13 Open Access OpenAccess
Notes Approved Most recent IF: 2.965
Call Number UA @ admin @ c:irua:177579 Serial 6967
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Author van ‘t Veer, K.; van Alphen, S.; Remy, A.; Gorbanev, Y.; De Geyter, N.; Snyders, R.; Reniers, F.; Bogaerts, A.
Title Spatially and temporally non-uniform plasmas: microdischarges from the perspective of molecules in a packed bed plasma reactor Type A1 Journal article
Year 2021 Publication Journal Of Physics D-Applied Physics Abbreviated Journal J Phys D Appl Phys
Volume 54 Issue 17 Pages 174002
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (down) Dielectric barrier discharges (DBDs) typically operate in the filamentary regime and thus exhibit great spatial and temporal non-uniformity. In order to optimize DBDs for various applications, such as in plasma catalysis, more fundamental insight is needed. Here, we consider how the millions of microdischarges, characteristic for a DBD, influence individual gas molecules. We use a Monte Carlo approach to determine the number of microdischarges to which a single molecule would be exposed, by means of particle tracing simulations through a full-scale packed bed DBD reactor, as well as an empty DBD reactor. We find that the fraction of microdischarges to which the molecules are exposed can be approximated as the microdischarge volume over the entire reactor gas volume. The use of this concept provides good agreement between a plasma-catalytic kinetics model and experiments for plasma-catalytic NH3 synthesis. We also show that the concept of the fraction of microdischarges indicates the efficiency by which the plasma power is transferred to the gas molecules. This generalised concept is also applicable for other spatially and temporally non-uniform plasmas.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000618776000001 Publication Date 2021-04-29
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 Open Access OpenAccess
Notes Excellence of Science FWO-FNRS project, FWO grant ID GoF9618n ; Flemish Government, project P2C (HBC.2019.0108) ; H2020 European Research Council, grant agreement No 810182 – SCOPE ERC Synergy pr ; This research was supported by the Excellence of Science FWO-FNRS project (FWO Grant ID GoF9618n, EOS ID 30505023), the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No 810182—SCOPE ERC Synergy project) and by the Flemish Government through the Moonshot cSBO project P2C (HBC. 2019.0108). The calculations were performed 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. The authors would also like to thank Hamid Ahmadi Eshtehardi for discussions on the plasma-kinetic DBD model and Yannick Engelmann for discussions on the surface kinetics model. Approved Most recent IF: 2.588
Call Number PLASMANT @ plasmant @c:irua:175878 Serial 6674
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Author Zheng, Y.-R.; Vernieres, J.; Wang, Z.; Zhang, K.; Hochfilzer, D.; Krempl, K.; Liao, T.-W.; Presel, F.; Altantzis, T.; Fatermans, J.; Scott, S.B.; Secher, N.M.; Moon, C.; Liu, P.; Bals, S.; Van Aert, S.; Cao, A.; Anand, M.; Nørskov, J.K.; Kibsgaard, J.; Chorkendorff, I.
Title Monitoring oxygen production on mass-selected iridium–tantalum oxide electrocatalysts Type A1 Journal article
Year 2021 Publication Nature Energy Abbreviated Journal Nat Energy
Volume Issue Pages
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract (down) Development of low-cost and high-performance oxygen evolution reaction catalysts is key to implementing polymer electrolyte membrane water electrolyzers for hydrogen production. Iridium-based oxides are the state-of-the-art acidic oxygen evolution reactio catalysts but still suffer from inadequate activity and stability, and iridium's scarcity motivates the discovery of catalysts with lower iridium loadings. Here we report a mass-selected iridium-tantalum oxide catalyst prepared by a magnetron-based cluster source with considerably reduced noble-metal loadings beyond a commercial IrO2 catalyst. A sensitive electrochemistry/mass-spectrometry instrument coupled with isotope labelling was employed to investigate the oxygen production rate under dynamic operating conditions to account for the occurrence of side reactions and quantify the number of surface active sites. Iridium-tantalum oxide nanoparticles smaller than 2 nm exhibit a mass activity of 1.2 ± 0.5 kA “g” _“Ir” ^“-1” and a turnover frequency of 2.3 ± 0.9 s-1 at 320 mV overpotential, which are two and four times higher than those of mass-selected IrO2, respectively. Density functional theory calculations reveal that special iridium coordinations and the lowered aqueous decomposition free energy might be responsible for the enhanced performance.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000728458000001 Publication Date 2021-12-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2058-7546 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 95 Open Access OpenAccess
Notes Y.-R.Z. and Z.W acknowledge funding from the Toyota Research Institute. This project has received funding from VILLUM FONDEN (grant no. 9455) and the European Research Council under the European Union’s Horizon 2020 research and innovation programme (grants no. 741860-CLUNATRA, no. 815128−REALNANO and no. 770887−PICOMETRICS). S.B. and S.V.A. acknowledge funding from the Research Foundation Flanders (FWO, G026718N and G050218N). T.A. acknowledges the University of Antwerp Research Fund (BOF). STEM measurements were supported by the European Union's Horizon 2020 Research Infrastructure-Integrating Activities for Advanced Communities under grant agreement No 823717 – ESTEEM3.; sygmaSB Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:184794 Serial 6903
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Author Yildiz, A.; Chouki, T.; Atli, A.; Harb, M.; Verbruggen, S.W.; Ninakanti, R.; Emin, S.
Title Efficient iron phosphide catalyst as a counter electrode in dye-sensitized solar cells Type A1 Journal article
Year 2021 Publication ACS applied energy materials Abbreviated Journal
Volume 4 Issue 10 Pages 10618-10626
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) Developing an efficient material as a counter electrode (CE) with excellent catalytic activity, intrinsic stability, and low cost is essential for the commercial application of dye-sensitized solar cells (DSSCs). Transition metal phosphides have been demonstrated as outstanding multifunctional catalysts in a broad range of energy conversion technologies. Here, we exploited different phases of iron phosphide as CEs in DSSCs with an I–/I3–-based electrolyte. Solvothermal synthesis using a triphenylphosphine precursor as a phosphorus source allows to grow a Fe2P phase at 300 °C and a FeP phase at 350 °C. The obtained iron phosphide catalysts were coated on fluorine-doped tin oxide substrates and heat-treated at 450 °C under an inert gas atmosphere. The solar-to-current conversion efficiency of the solar cells assembled with the Fe2P material reached 3.96 ± 0.06%, which is comparable to the device assembled with a platinum (Pt) CE. DFT calculations support the experimental observations and explain the fundamental origin behind the improved performance of Fe2P compared to FeP. These results indicate that the Fe2P catalyst exhibits excellent performance along with desired stability to be deployed as an efficient Pt-free alternative in DSSCs.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000711236300022 Publication Date 2021-10-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2574-0962 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:181953 Serial 7853
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Author Arslan Irmak, E.; Liu, P.; Bals, S.; Van Aert, S.
Title 3D Atomic Structure of Supported Metallic Nanoparticles Estimated from 2D ADF STEM Images: A Combination of Atom – Counting and a Local Minima Search Algorithm Type A1 Journal article
Year 2021 Publication Small methods Abbreviated Journal Small Methods
Volume Issue Pages 2101150
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (down) Determining the three-dimensional (3D) atomic structure of nanoparticles (NPs) is critical to understand their structure-dependent properties. It is hereby important to perform such analyses under conditions relevant for the envisioned application. Here, we investigate the 3D structure of supported Au NPs at high temperature, which is of importance to understand their behavior during catalytic reactions. To overcome limitations related to conventional high-resolution electron tomography at high temperature, 3D characterization of NPs with atomic resolution has been performed by applying atom-counting using atomic resolution annular darkfield scanning transmission electron microscopy (ADF STEM) images followed by structural relaxation. However, at high temperatures, thermal displacements, which affect the ADF STEM intensities, should be taken into account. Moreover, it is very likely that the structure of a NP investigated at elevated temperature deviates from a ground state configuration, which is difficult to determine using purely computational energy minimization approaches. In this paper, we therefore propose an optimized approach using an iterative local minima search algorithm followed by molecular dynamics (MD) structural relaxation of candidate structures associated with each local minimum. In this manner, it becomes possible to investigate the 3D atomic structure of supported NPs, which may deviate from their ground state configuration.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000716511600001 Publication Date 2021-11-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2366-9608 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 12 Open Access OpenAccess
Notes This work was supported by the European Research Council (Grant 815128 REALNANO to SB, Grant 770887 PICOMETRICS to SVA, Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0267.18N, G.0502.18N, G.0346.21N).; sygmaSB; esteem3jra; esteem3reported Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:183289 Serial 6820
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Author Trashin, S.; Morales-Yánez, F.; Thiruvottriyur Shanmugam, S.; Paredis, L.; Carrión, E.N.; Sariego, I.; Muyldermans, S.; Polman, K.; Gorun, S.M.; De Wael, K.
Title Nanobody-based immunosensor detection enhanced by photocatalytic-electrochemical redox cycling Type A1 Journal article
Year 2021 Publication Analytical Chemistry Abbreviated Journal Anal Chem
Volume 93 Issue 40 Pages 13606-13614
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Abstract (down) Detection of antigenic biomarkers present in trace amounts is of crucial importance for medical diagnosis. A parasitic disease, human toxocariasis, lacks an adequate diagnostic method despite its worldwide occurrence. The currently used serology tests may stay positive even years after a possibly unnoticed infection, whereas the direct detection of a re-infection or a still active infection remains a diagnostic challenge due to the low concentration of circulating parasitic antigens. We report a time-efficient sandwich immunosensor using small recombinant single-domain antibodies (nanobodies) derived from camelid heavy-chain antibodies specific to Toxocara canis antigens. An enhanced sensitivity to pg/mL levels is achieved by using a redox cycle consisting of a photocatalytic oxidation and electrochemical reduction steps. The photocatalytic oxidation is achieved by a photosensitizer generating singlet oxygen (1O2) that, in turn, readily reacts with p-nitrophenol enzymatically produced under alkaline conditions. The photooxidation produces benzoquinone that is electrochemically reduced to hydroquinone, generating an amperometric response. The light-driven process could be easily separated from the background, thus making amperometric detection more reliable. The proposed method for detection of the toxocariasis antigen marker shows superior performances compared to other detection schemes with the same nanobodies and outperforms by at least two orders of magnitude the assays based on regular antibodies, thus suggesting new opportunities for electrochemical immunoassays of challenging low levels of antigens.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000708550500025 Publication Date 2021-09-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.32 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 6.32
Call Number UA @ admin @ c:irua:181795 Serial 8290
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Author Kumar, N.; Perez-Novo, C.; Shaw, P.; Logie, E.; Privat-Maldonado, A.; Dewilde, S.; Smits, E.; Berghe, W.V.; Bogaerts, A.
Title Physical plasma-derived oxidants sensitize pancreatic cancer cells to ferroptotic cell death Type A1 Journal article
Year 2021 Publication Free Radical Biology And Medicine Abbreviated Journal Free Radical Bio Med
Volume 166 Issue Pages 187-200
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Abstract (down) Despite modern therapeutic advances, the survival prospects of pancreatic cancer patients remain poor, due to chemoresistance and dysregulated oncogenic kinase signaling networks. We applied a novel kinome activitymapping approach using biological peptide targets as phospho-sensors to identify vulnerable kinase de­pendencies for therapy sensitization by physical plasma. Ser/Thr-kinome specific activity changes were mapped upon induction of ferroptotic cell death in pancreatic tumor cells exposed to reactive oxygen and nitrogen species of plasma-treated water (PTW). This revealed a broad kinome activity response involving the CAMK, the AGC and CMGC family of kinases. This systems-level kinome network response supports stress adaptive switches between chemoresistant anti-oxidant responses of Kelch-like ECH-associated protein 1 (KEAP1)/Heme Oxy­genase 1 (HMOX1) and ferroptotic cell death sensitization upon suppression of Nuclear factor (erythroid derived 2)-like 2 (NRF2) and Glutathione peroxidase 4 (GPX4). This is further supported by ex vivo experiments in the chicken chorioallantoic membrane assay, showing decreased GPX4 and Glutathione (GSH) expression as well as increased lipid peroxidation, along with suppressed BxPC-3 tumor growth in response to PTW. Taken all together, we demonstrate that plasma treated water-derived oxidants sensitize pancreatic cancer cells to fer­roptotic cell death by targeting a NRF2-HMOX1-GPX4 specific kinase signaling network.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000632703400001 Publication Date 2021-02-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0891-5849 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.606 Times cited Open Access OpenAccess
Notes We gratefully acknowledge the financial support obtained from the Research Foundation Flanders (FWO), Belgium, grant number 12J5617 N and Department of Biotechnology (DBT) Ramalingaswami Re-entry Fellowship, India, grant number D.O.NO.BT/HRD/35/02/2006. We are thankful to the Laboratory of Experimental Hematology, for providing the facilities for the experimental and fluorescence micro­scopy work. The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the University of Antwerp, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI), Belgium. The Kinome profiling was performed at the Epigenetic Signaling service facility (PPES-UA) funded by the Hercules Foundation and Foundation against cancer Belgium (KOTK 7872). Approved Most recent IF: 5.606
Call Number PLASMANT @ plasmant @c:irua:176878 Serial 6711
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Author Uytdenhouwen, Y.; Hereijgers, J.; Breugelmans, T.; Cool, P.; Bogaerts, A.
Title How gas flow design can influence the performance of a DBD plasma reactor for dry reforming of methane Type A1 Journal article
Year 2021 Publication Chemical Engineering Journal Abbreviated Journal Chem Eng J
Volume 405 Issue Pages 126618
Keywords A1 Journal article; Engineering sciences. Technology; Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract (down) DBD plasma reactors are commonly used in a static ‘one inlet – one outlet’ design that goes against reactor design principles for multi-component reactions, such as dry reforming of methane (DRM). Therefore, in this paper we have developed a novel reactor design, and investigated how the shape and size of the reaction zone, as well as gradual gas addition, and the method of mixing CO2 and CH4 can influence the conversion and product com­ position of DRM. Even in the standard ‘one inlet – one outlet’ design, the direction of the gas flow (i.e. short or long path through the reactor, which defines the gas velocity at fixed residence time), as well as the dimensions of the reaction zone and the power delivery to the reactor, largely affect the performance. Using gradual gas addition and separate plasma activation zones for the individual gases give increased conversions within the same operational parameters, by optimising mixing ratios and kinetics. The choice of the main (pre-activated) gas and the direction of gas flow largely affect the conversion and energy cost, while the gas inlet position during separate addition only influences the product distribution.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000626511800005 Publication Date 2020-08-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1385-8947 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.216 Times cited Open Access OpenAccess
Notes Interreg; Flanders; FWO; University of Antwerp; The authors acknowledge financial support from the European Fund for Regional Development through the cross-border collaborative Interreg V program Flanders-the Netherlands (project EnOp), the Fund 13 for Scientific Research (FWO; grant number: G.0254.14N), and an IOFSBO (SynCO2Chem) project from the University of Antwerp. Approved Most recent IF: 6.216
Call Number PLASMANT @ plasmant @c:irua:170609 Serial 6410
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Author Velazco Torrejón, A.
Title Alternative scan strategies for high resolution STEM imaging Type Doctoral thesis
Year 2021 Publication Abbreviated Journal
Volume Issue Pages 131 p.
Keywords Doctoral thesis; Electron microscopy for materials research (EMAT)
Abstract (down) Currently, a large variety of materials are studied by transmission electron microscopy (TEM) as it offers the possibility to perform structural and elemental analysis at a local scale. Relatively recent advances in aberration correctors and electron sources allow the instrument to achieve atomic resolution. Along with these advances, a state-of-the-art technology has been reached in TEM. However, the instrument is far from being perfect and imperfections or external sources can make the interpretation of information troublesome. Environmental factors such as acoustic and mechanical vibrations, temperature fluctuations, etc., can induce sample drift and create image distortions. These distortions are enhanced in scanning operation because of the serial acquisition of the information, which are more apparent at atomic resolution as small field of views are imaged. In addition, scanning distortions are induced due to the finite time response of the scan coils. These types of distortions would reduce precision in atomic-scale strain analysis, for instance, in semiconductors. Most of the efforts to correct these distortions are focused on data processing techniques post-acquisition. Another limitation in TEM is beam damage effects. Beam damage arises because of the energy transferred to the sample in electron-sample interactions. In scanning TEM, at atomic resolution, the increased electron charge density (electron dose) carried on a sub-Å size electron probe may aggravate beam damage effects. Soft materials such as zeolites, organic, biological materials, etc., can be destroyed under irradiation limiting the amount of information that can be acquired. Current efforts to circumvent beam damage are mostly based on low electron dose acquisitions and data processing methods to maximize the signal at low dose conditions. In this thesis, a different approach is given to address drift and scanning distortions, as well as beam damage effects. Novel scan strategies are proposed for that purpose, which are shown to substantially overcome these issues compared to the standard scan method in TEM.
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Language Wos Publication Date
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Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:180973 Serial 6852
Permanent link to this record
 
 
Author Marchetti, A.
Title Novel insights and approaches for the analytical characterization of tangible cultural heritage objects Type Doctoral thesis
Year 2021 Publication Abbreviated Journal
Volume Issue Pages 333 p.
Keywords Doctoral thesis; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (down) Cultural heritage represents the vehicle of our cultural identity, handed over from past to future generations throughout human history. As a repository of fundamental cultural and social values, the preservation of all forms of cultural heritage is a responsibility of every society and of humankind as a whole. When it comes to tangible cultural heritage, preservation of heritage translates into preservation of objects and, therefore, of the materials they are constituted of. This crucial task relies heavily on the application of scientific analytical methods to answer material and conservation-related questions. ​ ​ The fundamental contribution of this analytical approach led, in the past decades, to an ever-deepening understanding of the factors governing the degradation of cultural heritage. However, the extreme complexity of the heritage object-environment system results in a massive research field, which inevitably presents relevant open questions. This is where the present PhD work comes into play, attempting to fill knowledge gaps in literature by starting from specific case studies and un-answered research questions. ​ ​ The multianalytical research conducted during this PhD unraveled fundamental information on the properties governing the reactivity and long-term behavior of different classes of materials, from α-brass in an indoor environment to artists’ pigments in the presence of light, moisture and soluble particulate matter (PM). The paramount importance of the synthesis conditions on the composition, physical properties and reactivity of heritage materials was also demonstrated, in particular for stable lead pyroantimonate and unstable Geranium lake artists’ pigments. Moreover, the study and characterization of specific heritage objects, namely a series of 16th century reliquary altarpieces and the painting L’Arlesienne, by Vincent Van Gogh, allowed to obtain relevant insights into their composition and on potential risks for their conservation. The challenging nature of the samples considered, created the perfect opportunity to test an innovative spectroscopic technique, optical photo-thermal IR (O-PTIR), for the characterization of heritage materials. Striking results were obtained, highlighting a great potential for the application of this non-destructive sub-micron molecular spectroscopy to the analysis of cultural heritage. Finally, in the last section of this work, strategies to implement the continuous monitoring of PM levels in indoor environmental quality studies were also considered, with a particular focus on the identification of environmental hazards for the collections housed in specific conservation environments (War Heritage Institute in Brussels and St. Martin’s church in Aalst, BE).
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Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
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Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:177849 Serial 8319
Permanent link to this record
 
 
Author Motta, M.; Burger, L.; Jiang, L.; Acosta, J.D.G.; Jelić, Ž.L.; Colauto, F.; Ortiz, W.A.; Johansen, T.H.; Milošević, M.V.; Cirillo, C.; Attanasio, C.; Xue, C.; Silhanek, A., V.; Vanderheyden, B.
Title Metamorphosis of discontinuity lines and rectification of magnetic flux avalanches in the presence of noncentrosymmetric pinning forces Type A1 Journal article
Year 2021 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 103 Issue 22 Pages 224514
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (down) Considering a noncentrosymmetric pinning texture composed of a square array of triangular holes, the magnetic flux penetration and expulsion are investigated experimentally and theoretically. A direct visualization of the magnetic landscape obtained using a magneto-optical technique on a Nb film is complemented by a multiscale numerical modeling. This combined approach allows the magnetic flux dynamics to be identified from the single flux quantum limit up to the macroscopic electromagnetic response. Within the theoretical framework provided by time-dependent Ginzburg-Landau simulations, an estimation of the in-plane current anisotropy is obtained and its dependence with the radius of the curvature of hole vertices is addressed. These simulations show that current crowding plays an important role in channeling the flux motion, favoring hole-to-hole flux hopping rather than promoting interstitial flux displacement in between the holes. The resulting anisotropy of the critical current density gives rise to a distinct pattern of discontinuity lines for increasing and decreasing applied magnetic fields, in sharp contrast to the invariable patterns reported for centrosymmetric pinning potentials. This observation is partially accounted for by the rectification effect, as demonstrated by finite-element modeling. At low temperatures, where magnetic field penetration is dominated by thermomagnetic instabilities, highly directional magnetic flux avalanches with a fingerlike shape are observed to propagate along the easy axis of the pinning potential. This morphology is reproduced by numerical simulations. Our findings demonstrate that anisotropic pinning landscapes and, in particular, ratchet potentials produce subtle modifications to the critical state field profile that are reflected in the distribution of discontinuity lines.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000687246200001 Publication Date 2021-06-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 6 Open Access OpenAccess
Notes Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:181714 Serial 7002
Permanent link to this record
 
 
Author Li, C.; Tardajos, A.P.; Wang, D.; Choukroun, D.; Van Daele, K.; Breugelmans, T.; Bals, S.
Title A simple method to clean ligand contamination on TEM grids Type A1 Journal article
Year 2021 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 221 Issue Pages 113195
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract (down) Colloidal nanoparticles (NPs) including nanowires and nanosheets made by chemical methods involve many organic ligands. When the structure of NPs is investigated via transmission electron microscopy (TEM), the organic ligands act as a source for e-beam induced deposition and this causes substantial build-up of carbon layers in the investigated areas, which is typically referred to as “contamination” in the eld of electron mi- croscopy. This contamination is often more severe for scanning TEM, a technique that is based on a focused electron beam and hence higher electron dose rate. In this paper, we report a simple and effective method to clean drop-cast TEM grids that contain NPs with ligands. Using a combination of activated carbon and ethanol, this method effectively reduces the amount of ligands on TEM grids, and therefore greatly improves the quality of electron microscopy images and subsequent analytical measurements. This ef cient and facile method can be helpful during electron microscopy investigation of different kinds of nanomaterials that suffer from ligand- induced contamination.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000612539600002 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 10 Open Access OpenAccess
Notes This research was funded by the University Antwerp GOA project (ID 33928). DW acknowledges an Individual Fellowship funded by the Marie Sklodowska-Curie Actions (MSCA) in Horizon 2020 program (grant 894254 SuprAtom). Approved Most recent IF: 2.843
Call Number EMAT @ emat @c:irua:174947 Serial 6666
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Author Choukroun, D.; Pacquets, L.; Li, C.; Hoekx, S.; Arnouts, S.; Baert, K.; Hauffman, T.; Bals, S.; Breugelmans, T.
Title Mapping composition–selectivity relationships of supported sub-10 nm Cu–Ag nanocrystals for high-rate CO₂ electroreduction Type A1 Journal article
Year 2021 Publication Acs Nano Abbreviated Journal Acs Nano
Volume 15 Issue 9 Pages 14858-14872
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract (down) Colloidal Cu–Ag nanocrystals measuring less than 10 nm across are promising candidates for integration in hybrid CO2 reduction reaction (CO2RR) interfaces, especially in the context of tandem catalysis and selective multicarbon (C2–C3) product formation. In this work, we vary the synthetic-ligand/copper molar ratio from 0.1 to 1.0 and the silver/copper atomic ratio from 0 to 0.7 and study the variations in the nanocrystals’ size distribution, morphology and reactivity at rates of ≥100 mA cm–2 in a gas-fed recycle electrolyzer operating under neutral to mildly basic conditions (0.1–1.0 M KHCO3). High-resolution electron microscopy and spectroscopy are used in order to characterize the morphology of sub-10 nm Cu–Ag nanodimers and core–shells and to elucidate trends in Ag coverage and surface composition. It is shown that Cu–Ag nanocrystals can be densely dispersed onto a carbon black support without the need for immediate ligand removal or binder addition, which considerably facilitates their application. Although CO2RR product distribution remains an intricate function of time, (kinetic) overpotential and processing conditions, we nevertheless conclude that the ratio of oxygenates to hydrocarbons (which depends primarily on the initial dispersion of the nanocrystals and their composition) rises 3-fold at moderate Ag atom % relative to Cu NCs-based electrodes. Finally, the merits of this particular Cu–Ag/C system and the recycling reactor employed are utilized to obtain maximum C2–C3 partial current densities of 92–140 mA cm–2 at −1.15 VRHE and liquid product concentrations in excess of 0.05 wt % in 1 M KHCO3 after short electrolysis periods.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000703553600082 Publication Date 2021-08-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 25 Open Access OpenAccess
Notes D.C. acknowledges Thomas Kenis for configuring the analytical instrumentation (HPLC/GC-FID/ICP-MS), Hannelore Andries for assistance with ICP-MS measurements, and Dr. Saeid Pourbabak and Dr. Tine Derez for assistance with Cu sputtering. L.P. was supported by Research Foundation of Flanders (FWO 1S56920N). S.B. acknowledges financial support from ERC Consolidator grant number 815128 REALNANO. S.B. and T.B. acknowledge financial support from the university research fund (BOF-GOA-PS ID no. 33928).; sygmaSB Approved Most recent IF: 13.942
Call Number UA @ admin @ c:irua:180305 Serial 6844
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Author Xia, C.; Pedrazo-Tardajos, A.; Wang, D.; Meeldijk, J.D.; Gerritsen, H.C.; Bals, S.; de Donega, C.M.
Title Seeded growth combined with cation exchange for the synthesis of anisotropic Cu2-xS/ZnS, Cu2-xS, and CuInS2 nanorods Type A1 Journal article
Year 2021 Publication Chemistry of materials Abbreviated Journal
Volume 33 Issue 1 Pages 102-116
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Colloidal copper(I) sulfide (Cu2-xS) nanocrystals (NCs) have attracted much attention for a wide range of applications because of their unique optoelectronic properties, driving scientists to explore the potential of using Cu2-xS NCs as seeds in the synthesis of heteronanocrystals to achieve new multifunctional materials. Herein, we developed a multistep synthesis strategy toward Cu2-xS/ZnS heteronanorods. The Janus-type Cu2-xS/ZnS heteronanorods are obtained by the injection of hexagonal high-chalcocite Cu2-xS seed NCs in a hot zinc oleate solution in the presence of suitable surfactants, 20 s after the injection of sulfur precursors. The Cu2-xS seed NCs undergo rapid aggregation and coalescence in the first few seconds after the injection, forming larger NCs that act as the effective seeds for heteronucleation and growth of ZnS. The ZnS heteronucleation occurs on a single (100) facet of the Cu2-xS seed NCs and is followed by fast anisotropic growth along a direction that is perpendicular to the c-axis, thus leading to Cu2-xS/ZnS Janus-type heteronanorods with a sharp heterointerface. Interestingly, the high-chalcocite crystal structure of the injected Cu2-xS seed NCs is preserved in the Cu2-xS segments of the heteronanorods because of the highthermodynamic stability of this Cu2-xS phase. The Cu2-xS/ZnS heteronanorods are subsequently converted into single-component Cu2-xS and CuInS2 nanorods by postsynthetic topotactic cation exchange. This work expands the possibilities for the rational synthesis of colloidal multicomponent heteronanorods by allowing the design principles of postsynthetic heteroepitaxial seeded growth and nanoscale cation exchange to be combined, yielding access to a plethora of multicomponent heteronanorods with diameters in the quantum confinement regime.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000610984700009 Publication Date 2020-12-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 10 Open Access OpenAccess
Notes C.X. acknowledges China Scholarship Council (CSC) for the financial support (grant number 201406330055). C.d.M.D. acknowledges funding from the European Commission for access to the EMAT facilities (grant number EUSMI E180900184). D.W. acknowledges an Individual Fellowship funded by the Marie Sklodowska-Curie Actions (MSCA) in Horizon 2020 program (grant 894254 SuprAtom). S.B. acknowledges support by means of the ERC Consolidator grant no. 815128 REALNANO. The authors thank Donglong Fu for XRD measurements.; sygma Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:176587 Serial 6732
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Author Bengtson, C.; Bogaerts, A.
Title The Quest to Quantify Selective and Synergistic Effects of Plasma for Cancer Treatment: Insights from Mathematical Modeling Type A1 Journal article
Year 2021 Publication International Journal Of Molecular Sciences Abbreviated Journal Int J Mol Sci
Volume 22 Issue 9 Pages 5033
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (down) Cold atmospheric plasma (CAP) and plasma-treated liquids (PTLs) have recently become a promising option for cancer treatment, but the underlying mechanisms of the anti-cancer effect are still to a large extent unknown. Although hydrogen peroxide () has been recognized as the major anti-cancer agent of PTL and may enable selectivity in a certain concentration regime, the co-existence of nitrite can create a synergistic effect. We develop a mathematical model to describe the key species and features of the cellular response toward PTL. From the numerical solutions, we define a number of dependent variables, which represent feasible measures to quantify cell susceptibility in terms of the membrane diffusion rate constant and the intracellular catalase concentration. For each of these dependent variables, we investigate the regimes of selective versus non-selective, and of synergistic versus non-synergistic effect to evaluate their potential role as a measure of cell susceptibility. Our results suggest that the maximal intracellular concentration, which in the selective regime is almost four times greater for the most susceptible cells compared to the most resistant cells, could be used to quantify the cell susceptibility toward exogenous . We believe our theoretical approach brings novelty to the field of plasma oncology, and more broadly, to the field of redox biology, by proposing new ways to quantify the selective and synergistic anti-cancer effect of PTL in terms of inherent cell features.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000650366900001 Publication Date 2021-05-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1422-0067 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.226 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 3.226
Call Number PLASMANT @ plasmant @c:irua:178123 Serial 6757
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Author Quintero-Coronel, D.A.; Lenis-Rodas, Y.A.; Corredor, L.A.; Perreault, P.; Gonzalez-Quiroga, A.
Title Thermochemical conversion of coal and biomass blends in a top-lit updraft fixed bed reactor : experimental assessment of the ignition front propagation velocity Type A1 Journal article
Year 2021 Publication Energy Abbreviated Journal Energy
Volume 220 Issue Pages 119702-119710
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) Co-thermochemical conversion of coal and biomass can potentially decrease the use of fossil carbon and pollutant emissions. This work presents experimental results for the so-called top-lit updraft fixed bed reactor, in which the ignition front starts at the top and propagates downward while the gas product flows upwards. The study focuses on the ignition front propagation velocity for the co-thermochemical conversion of palm kernel shell and high-volatile bituminous coal. Within the range of assessed air superficial velocities, the process occurred under gasification and near stoichiometric conditions. Under gasification conditions increasing coal particle size from 7.1 to 22 mm decreased ignition front velocity by around 26% regardless of the coal volume percentage. Furthermore, increasing coal volume percentage and decreasing coal particle size result in product gas with higher energy content. For the operation near stoichiometric conditions, increasing coal volume percentage from 10 to 30% negatively affected the ignition front velocity directly proportional to its particle size. Additional experiments confirmed a linear dependence of ignition front velocity on air superficial velocity. Further steps in the development of the top-lit updraft technology are implementing continuous solids feeding and variable cross-sectional area and optimizing coal particle size distribution.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000623087300003 Publication Date 2020-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0360-5442 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.52 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.52
Call Number UA @ admin @ c:irua:175861 Serial 8664
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