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Author | Kerkhofs, S.; Willhammar, T.; Van Den Noortgate, H.; Kirschhock, C.E.A.; Breynaert, E.; Van Tendeloo, G.; Bals, S.; Martens, J.A. | ||||
Title | Self-Assembly of Pluronic F127—Silica Spherical Core–Shell Nanoparticles in Cubic Close-Packed Structures | Type | A1 Journal article | ||
Year | 2015 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
Volume | 27 | Issue | 27 | Pages | 5161-5169 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A new ordered mesoporous silica material (COK-19) with cubic symmetry is synthesized by silicate polycondensation in a citric acid/citrate buffered micellar solution of Pluronic F127 triblock copolymer near neutral pH. SAXS, nitrogen adsorption, TEM, and electron tomography reveal the final material has a cubic close packed symmetry (Fm3̅m) with isolated spherical mesopores interconnected through micropores. Heating of the synthesis medium from room temperature to 70 °C results in a mesopore size increase from 7.0 to 11.2 nm. Stepwise addition of the silicate source allows isolation of a sequence of intermediates that upon characterization with small-angle X-ray scattering uncovers the formation process via formation and aggregation of individual silica-covered Pluronic micelles. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000359499100003 | Publication Date | 2015-07-24 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 39 | Open Access | OpenAccess |
Notes | J.A.M. acknowledges the Flemish government for long-term structural funding (Methusalem, METH/08/04). The Belgian government is acknowledged for financing the interuniversity poles of attraction (IAP-PAI, P7/05 FS2). G.V.T., S.B. and T.W. acknowledge financial support from European Research Council (ERC Starting Grant no. 335078-COLOURATOMS). E.B. acknowledges financial support the Flemish FWO for a postdoctoral fellowship (1265013N). The authors gratefully thank Kristof Houthoofd for performing the NMR experiments.; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); | Approved | Most recent IF: 9.466; 2015 IF: 8.354 | ||
Call Number | c:irua:127758 | Serial | 3977 | ||
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Author | Morozov, V.A.; Arakcheeva, A.V.; Pattison, P.; Meert, K.W.; Smet, P.F.; Poelman, D.; Gauquelin, N.; Verbeeck, J.; Abakumov, A.M.; Hadermann, J. | ||||
Title | KEu(MoO4)2 : polymorphism, structures, and luminescent properties | Type | A1 Journal article | ||
Year | 2015 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
Volume | 27 | Issue | 27 | Pages | 5519-5530 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | In this paper, with the example of two different polymorphs of KEu(MoO4)2, the influence of the ordering of the A-cations on the luminescent properties in scheelite related compounds (A′,A″)n[(B′,B″)O4]m is investigated. The polymorphs were synthesized using a solid state method. The study confirmed the existence of only two polymorphic forms at annealing temperature range 9231203 K and ambient pressure: a low temperature anorthic α-phase and a monoclinic high temperature β-phase with an incommensurately modulated structure. The structures of both polymorphs were solved using transmission electron microscopy and refined from synchrotron powder X-ray diffraction data. The monoclinic β-KEu(MoO4)2 has a (3+1)-dimensional incommensurately modulated structure (superspace group I2/b(αβ0)00, a = 5.52645(4) Å, b = 5.28277(4) Å, c = 11.73797(8) Å, γ = 91.2189(4)o, q = 0.56821(2)a*0.12388(3)b*), whereas the anorthic α-phase is (3+1)-dimensional commensurately modulated (superspace group I1̅(αβγ)0, a = 5.58727(22) Å, b = 5.29188(18)Å, c = 11.7120(4) Å, α = 90.485(3)o, β = 88.074(3)o, γ = 91.0270(23)o, q = 1/2a* + 1/2c*). In both cases the modulation arises due to Eu/K cation ordering at the A site: the formation of a 2-dimensional Eu3+ network is characteristic for the α-phase, while a 3-dimensional Eu3+-framework is observed for the β-phase structure. The luminescent properties of KEu(MoO4)2 samples prepared under different annealing conditions were measured, and the relation between their optical properties and their structures is discussed. | ||||
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Language | Wos | 000360323700011 | Publication Date | 2015-07-29 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756;1520-5002; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 26 | Open Access | |
Notes | 278510 Vortex; Fwo G039211n; G004413n ECASJO_; | Approved | Most recent IF: 9.466; 2015 IF: 8.354 | ||
Call Number | c:irua:127244 | Serial | 3537 | ||
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Author | Quintelier, M.; Hajizadeh, A.; Zintler, A.; Gonçalves, B.F.; Fernández de Luis, R.; Esrafili Dizaji, L.; Vande Velde, C.M.L.; Wuttke, S.; Hadermann, J. | ||||
Title | In SituStudy of the Activation Process of MOF-74 Using Three-Dimensional Electron Diffraction | Type | A1 Journal Article | ||
Year | 2024 | Publication | Chemistry of Materials | Abbreviated Journal | Chem. Mater. |
Volume | Issue | Pages | |||
Keywords | A1 Journal Article; 3DED; MOFs; in situ; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | Metal–organic framework (MOF)-74 is known for its effectiveness in selectively capturing carbon dioxide (CO2). Especially the Zn and Cu versions of MOF-74 show high efficiency of this material for CO2. However, the activation of this MOF, which is a crucial step for its utilization, is so far not well understood. Here, we are closing the knowledge gap by examining the activation using, for the first time in the MOF, three-dimensional electron diffraction (3DED) during in situ heating. The use of state-of-the-art direct electron detectors enables rapid acquisition and minimal exposure times, therefore minimizing beam damage to the very electron beam-sensitive MOF material. The activation process of Zn-MOF-74 and Cu-MOF-74 is systematically studied in situ, proving the creation of open metal sites. Differences in thermal stability between Zn-MOF-74 and Cu-MOF-74 are attributed to the strength of the metal–oxygen bonds and Jahn–Teller distortions. In the case of Zn-MOF-74, we observe previously unknown remaining electrostatic potentials inside the MOF pores, which indicate the presence of remaining atoms that might impede gas flow throughout the structure when using the MOF for absorption purposes. We believe our study exemplifies the significance of employing advanced characterization techniques to enhance our material understanding, which is a crucial step for unlocking the full potential of MOFs in various applications. | ||||
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Language | Wos | https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=brocade2&SrcAuth=WosAPI&KeyUT=WOS:001275 | Publication Date | 2024-07-22 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 8.6 | Times cited | Open Access | ||
Notes | European Regional Development Fund, PID2021-122940OB-C31 ; H2020 Energy, 101022633 ; Universiteit Antwerpen, BOF TOP 38689 ; H2020 Marie Sklodowska-Curie Actions, 956099 ; Fonds Wetenschappelijk Onderzoek, I003218N ; Japan Science and Technology Agency, JPMJSC2102 ; Funda??o de Amparo ? Pesquisa do Estado de S?o Paulo; Agencia Estatal de Investigaci?n,Ministerio de Ciencia, Innovaci?n y Universidades, PID2021-122940OB-C31 TED2021-130621B-C42 ; | Approved | Most recent IF: 8.6; 2024 IF: 9.466 | ||
Call Number | EMAT @ emat @c:irua:207555 | Serial | 9255 | ||
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Author | Chowdhury, M.S.; Esteban, D.A.; Amin, R.; Román-Freijeiro, C.; Rösch, E.L.; Etzkorn, M.; Schilling, M.; Ludwig, F.; Bals, S.; Salgueiriño, V.; Lak, A. | ||||
Title | Organic Molecular Glues to Design Three-Dimensional Cubic Nano-assemblies of Magnetic Nanoparticles | Type | A1 Journal Article | ||
Year | 2024 | Publication | Chemistry of Materials | Abbreviated Journal | Chem. Mater. |
Volume | 36 | Issue | 14 | Pages | 6865-6876 |
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
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Language | Wos | https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=brocade2&SrcAuth=WosAPI&KeyUT=WOS:001275 | Publication Date | 2024-07-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 8.6 | Times cited | Open Access | ||
Notes | Ministerio de Ciencia e Innovaci?n, PID2020-119242-I00 ; Deutsche Forschungsgemeinschaft, LA 4923/3-1 RTG 1952 ; Horizon 2020 Framework Programme, 823717 ; | Approved | Most recent IF: 8.6; 2024 IF: 9.466 | ||
Call Number | EMAT @ emat @c:irua:207594 | Serial | 9258 | ||
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Author | Vandemeulebroucke, D.; Batuk, M.; Hajizadeh, A.; Wastiaux, M.; Roussel, P.; Hadermann, J. | ||||
Title | Incommensurate Modulations and Perovskite Growth in LaxSr2–xMnO4−δAffecting Solid Oxide Fuel Cell Conductivity | Type | A1 Journal article | ||
Year | 2024 | Publication | Chemistry of materials | Abbreviated Journal | Chem. Mater. |
Volume | Issue | Pages | |||
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Ruddlesden-Popper La????Sr2−????MnO4−???? materials are interesting symmetric solid oxide fuel cell electrodes due to their good redox stability, mixed ionic and electronic conducting behavior and thermal expansion that matches well with common electrolytes. In reducing environments – as at a solid oxide fuel cell anode – the x = 0.5 member, i.e. La0.5Sr1.5MnO4−????, has a much higher total conductivity than compounds with a different La/Sr ratio, although all those compositions have the same K2NiF4-type I4/mmm structure. The origin for this conductivity difference is not yet known in literature. Now, a combination of in-situ and ex-situ 3D electron diffraction, high-resolution imaging, energy-dispersive X-ray analysis and electron energy-loss spectroscopy uncovered clear differences between x=0.25 and x=0.5 in the pristine structure, as well as in the transformations upon high-temperature reduction. In La0.5Sr1.5MnO4−????, Ruddlesden-Popper n=2 layer defects and an amorphous surface layer are present, but not in La0.25Sr1.75MnO4−????. After annealing at 700°C in 5% H2/Ar, La0.25Sr1.75MnO4−???? transforms to a tetragonal 2D incommensurately modulated structure with modulation vectors ⃗????1 = 0.2848(1) · (⃗????* +⃗????*) and ⃗????2 =0.2848(1) · (⃗????* – ⃗????*), whereas La0.5Sr1.5MnO4−???? only partially transforms to an orthorhombic 1D incommensurately modulated structure, with ⃗???? = 0.318(2) · ⃗????*. Perovskite domains grow at the crystal edge at 700°C in 5% H2 or vacuum, due to the higher La concentration on the surface compared to the bulk, which leads to a different thermodynamic equilibrium. Since it is known that a lower degree of oxygen vacancy ordering and a higher amount of perovskite blocks enhance oxygen mobility, those differences in defect structure and structural transformation upon reduction, might all contribute to the higher conductivity of La0.5Sr1.5MnO4−???? in solid oxide fuel cell anode conditions compared to other La/Sr ratios. |
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Language | English | Wos | 001174840900001 | Publication Date | 2024-02-20 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 8.6 | Times cited | Open Access | Not_Open_Access | |
Notes | Universiteit Antwerpen, BOF TOP 38689 ; Fonds Wetenschappelijk Onderzoek, I003218N ; European Commission NanED, 956099 ; | Approved | Most recent IF: 8.6; 2024 IF: 9.466 | ||
Call Number | EMAT @ emat @c:irua:204354 | Serial | 8997 | ||
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Author | Manzaneda-Gonzalez, V.; Jenkinson, K.; Pena-Rodriguez, O.; Borrell-Grueiro, O.; Trivino-Sanchez, S.; Banares, L.; Junquera, E.; Espinosa, A.; Gonzalez-Rubio, G.; Bals, S.; Guerrero-Martinez, A. | ||||
Title | From multi- to single-hollow trimetallic nanocrystals by ultrafast heating | Type | A1 Journal article | ||
Year | 2023 | Publication | Chemistry of materials | Abbreviated Journal | |
Volume | 35 | Issue | 22 | Pages | 9603-9612 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Metal nanocrystals (NCs) display unique physicochemical features that are highly dependent on nanoparticle dimensions, anisotropy, structure, and composition. The development of synthesis methodologies that allow us to tune such parameters finely emerges as crucial for the application of metal NCs in catalysis, optical materials, or biomedicine. Here, we describe a synthetic methodology to fabricate hollow multimetallic heterostructures using a combination of seed-mediated growth routes and femtosecond-pulsed laser irradiation. The envisaged methodology relies on the coreduction of Ag and Pd ions on gold nanorods (Au NRs) to form Au@PdAg core-shell nanostructures containing small cavities at the Au-PdAg interface. The excitation of Au@PdAg NRs with low fluence femtosecond pulses was employed to induce the coalescence and growth of large cavities, forming multihollow anisotropic Au@PdAg nanostructures. Moreover, single-hollow alloy AuPdAg could be achieved in high yield by increasing the irradiation energy. Advanced electron microscopy techniques, energy-dispersive X-ray spectroscopy (EDX) tomography, X-ray absorption near-edge structure (XANES) spectroscopy, and finite differences in the time domain (FDTD) simulations allowed us to characterize the morphology, structure, and elemental distribution of the irradiated NCs in detail. The ability of the reported synthesis route to fabricate multimetallic NCs with unprecedented hollow nanostructures offers attractive prospects for the fabrication of tailored high-entropy alloy nanoparticles. | ||||
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Language | Wos | 001110623500001 | Publication Date | 2023-11-06 | |
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ISSN | 0897-4756; 1520-5002 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.6 | Times cited | 2 | Open Access | OpenAccess |
Notes | Approved | Most recent IF: 8.6; 2023 IF: 9.466 | |||
Call Number | UA @ admin @ c:irua:202144 | Serial | 9040 | ||
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Author | Mayda, S.; Monico, L.; Krishnan, D.; De Meyer, S.; Cotte, M.; Garrevoet, J.; Falkenberg, G.; Sandu, I.C.A.; Partoens, B.; Lamoen, D.; Romani, A.; Miliani, C.; Verbeeck, J.; Janssens, K. | ||||
Title | A combined experimental and computational approach to understanding CdS pigment oxidation in a renowned early 20th century painting | Type | A1 Journal article | ||
Year | 2023 | Publication | Chemistry of materials | Abbreviated Journal | |
Volume | 35 | Issue | 24 | Pages | 10403-10415 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Antwerp X-ray Imaging and Spectroscopy (AXIS) | ||||
Abstract | Cadmium sulfide (CdS)-based yellow pigments have been used in a number of early 20th century artworks, including The Scream series painted by Edvard Munch. Some of these unique paintings are threatened by the discoloration of these CdS-based yellow oil paints because of the oxidation of the original sulfides to sulfates. The experimental data obtained here prove that moisture and cadmium chloride compounds play a key role in promoting such oxidation. To clarify how these two factors effectively prompt the process, we studied the band alignment between CdS, CdCl2, and Cd-(OH)Cl as well as the radicals center dot OH and H3O center dot by density functional theory (DFT) methods. Our results show that a stack of several layers of Cd-(OH)Cl creates a pocket of positive holes at the Cl-terminated surface and a pocket of electrons at the OH-terminated surface by leading in a difference in ionization energy at both surfaces. The resulting band alignment indicates that Cd-(OH)Cl can indeed play the role of an oxidative catalyst for CdS in a moist environment, thus providing an explanation for the experimental evidence. | ||||
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Language | Wos | 001133000900001 | Publication Date | 2023-12-08 | |
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ISSN | 0897-4756; 1520-5002 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 8.6 | Times cited | Open Access | ||
Notes | The experimental research on the cadmium yellow powders/paint mock-ups and The Scream (ca. 1910) was financially supported by the European Union, research projects IPERION-CH (H2020-INFRAIA-2014-2015, GA no. 654028) and IPERION-HS (H2020-INFRAIA-2019-1, GA no. 871034) and the project AMIS within the program Dipartimenti di Eccellenza 2018-2022 (funded by MUR and the University of Perugia). For the beamtime grants received, the authors thank the ESRF-ID21 beamline (experiments HG64 and HG95), the DESY-P06 beamline, a member of the Helmholtz Association HGF (experiments I-20130221 EC and I-20160126 EC), and the project CALIPSOplus under the GA no. 730872 from the E.U. Framework Programme for Research and Innovation Horizon 2020. All of the staff of the MUNCH Museum (Conservation Department) is acknowledged for their collaboration. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO – Vlaanderen and the Flemish Government, Department EWI. | Approved | Most recent IF: 8.6; 2023 IF: 9.466 | ||
Call Number | UA @ admin @ c:irua:202836 | Serial | 8999 | ||
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Author | Sa, J.; Hu, N.; Heyvaert, W.; Van Gordon, K.; Li, H.; Wang, L.; Bals, S.; Liz-Marzán, L.M.; Ni, W. | ||||
Title | Spontaneous Chirality Evolved at the Au–Ag Interface in Plasmonic Nanorods | Type | A1 Journal article | ||
Year | 2023 | Publication | Chemistry of materials | Abbreviated Journal | Chem. Mater. |
Volume | Issue | Pages | |||
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Chiral ligands are considered a required ingredient during the synthesis of dissymmetric plasmonic metal nanocrystals. The mechanism behind the generation of chiral structures involves the formation of high Miller index chiral facets, induced by the adsorption of such chiral ligands. We found however that, chirality can also evolve spontaneously, without the involvement of any chiral ligands, during the co-deposition of Au and Ag on Au nanorods. When using a specific Au/Ag ratio, phase segregation of the two metals leads to an interface within the obtained AuAg shell, which can be exposed by removing the Ag component via oxidative etching. Although a close-to-racemic mixture of chiral Au nanorods with right and left handedness is found in solution, electron tomography analysis evidences left- and righthanded helicities, both at the Au-Ag interface and at the exposed surface of Au NRs after Ag etching. The helicity profile of the NRs indicates dominating inclination angles in a range from 30° to 60°. Single-particle optical characterization also reveals random handedness in the plasmonic response of individual nanorods. We hypothesize that, the origin of chirality is related with symmetry breaking during the co-deposition of Au and Ag, through an initial perturbation in a small region on the Au-Ag interface that eventually leads to chiral segregation throughout the nanocrystal. | ||||
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Language | Wos | 001052093300001 | Publication Date | 2023-08-21 | |
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ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 8.6 | Times cited | Open Access | OpenAccess | |
Notes | The authors acknowledge the financial support from the National Natural Science Foundation of China (grant 22074102). LMLM acknowledges funding from 26 MCIN/AEI/10.13039/501100011033 and “ESF Investing in your future” (Grant PID2020- 117779RB-I00). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3.; Ministerio de Ciencia e Innovaci?n, PID2020-117779RB-I00 ; H2020 Research Infrastructures, 823717 ; European Social Fund, PID2020-117779RB-I00 ; National Natural Science Foundation of China, 22074102 ; | Approved | Most recent IF: 8.6; 2023 IF: 9.466 | ||
Call Number | EMAT @ emat @c:irua:198151 | Serial | 8810 | ||
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Author | Arenas Esteban, D.; Pacquets, L.; Choukroun, D.; Hoekx, S.; Kadu, A.A.; Schalck, J.; Daems, N.; Breugelmans, T.; Bals, S. | ||||
Title | 3D characterization of the structural transformation undergone by Cu@Ag core-shell nanoparticles following CO₂ reduction reaction | Type | A1 Journal article | ||
Year | 2023 | Publication | Chemistry of materials | Abbreviated Journal | |
Volume | 35 | Issue | 17 | Pages | 6682-6691 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | The increasing use of metallic nanoparticles (NPs) is significantly advancing the field of electrocatalysis. In particular, Cu/Ag bimetallic interfaces are widely used to enhance the electrochemical CO2 reduction reaction (eCO(2)RR) toward CO and, more recently, C-2 products. However, drastic changes in the product distribution and performance when Cu@Ag core-shell configurations are used can often be observed under electrochemical reaction conditions, especially during the first few minutes of the reaction. Possible structural changes that generate these observations remain underexplored; therefore, the structure-property relationship is hardly understood. In this study, we use electron tomography to investigate the structural transformation mechanism of Cu@Ag core-shells NPs during the critical first minutes of the eCO(2)RR. In this manner, we found that the crystallinity of the Cu seed determines whether the formation of a complete and homogeneous Ag shell is possible. Moreover, by tracking the particles' transformations, we conclude that modifications of the Cu-Ag interface and Cu2O enrichment at the surface of the NPs are key factors contributing to the product generation changes. These insights provide a better understanding of how bimetallic core-shell NPs transform under electrochemical conditions. | ||||
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Language | Wos | 001061530700001 | Publication Date | 2023-08-31 | |
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ISSN | 0897-4756; 1520-5002 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.6 | Times cited | 1 | Open Access | OpenAccess |
Notes | L.P. was supported through a PhD fellowship for strategicbasic research (1S56920N) of the Research Foundation – Flanders(FWO). S.H. was supported through a PhD fellowship for strategic basicresearch (1S42623N) of the Research Foundation – Flanders (FWO).S.B., D.A.E., and A.A.K. acknowledge financial support from ERC Consolidator Grant Number 815128 REALNANO. This research was financed by the researchcouncil of the University of Antwerp (BOF-GOA 33928). | Approved | Most recent IF: 8.6; 2023 IF: 9.466 | ||
Call Number | UA @ admin @ c:irua:199187 | Serial | 8825 | ||
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Author | Mulder, J.T.T.; Jenkinson, K.; Toso, S.; Prato, M.; Evers, W.H.H.; Bals, S.; Manna, L.; Houtepen, A.J.J. | ||||
Title | Nucleation and growth of bipyramidal Yb:LiYF₄ nanocrystals : growing up in a hot environment | Type | A1 Journal article | ||
Year | 2023 | Publication | Chemistry of materials | Abbreviated Journal | |
Volume | 35 | Issue | 14 | Pages | 5311-5321 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Lanthanide-doped LiYF4 (Ln:YLF) is commonlyused fora broad variety of optical applications, such as lasing, photon upconversionand optical refrigeration. When synthesized as nanocrystals (NCs),this material is also of interest for biological applications andfundamental physical studies. Until now, it was unclear how Ln:YLFNCs grow from their ionic precursors into tetragonal NCs with a well-defined,bipyramidal shape and uniform dopant distribution. Here, we studythe nucleation and growth of ytterbium-doped LiYF4 (Yb:YLF),as a template for general Ln:YLF NC syntheses. We show that the formationof bipyramidal Yb:YLF NCs is a multistep process starting with theformation of amorphous Yb:YLF spheres. Over time, these spheres growvia Ostwald ripening and crystallize, resulting in bipyramidal Yb:YLFNCs. We further show that prolonged heating of the NCs results inthe degradation of the NCs, observed by the presence of large LiFcubes and small, irregular Yb:YLF NCs. Due to the similarity in chemicalnature of all lanthanide ions our work sheds light on the formationstages of Ln:YLF NCs in general. | ||||
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Language | Wos | 001021474500001 | Publication Date | 2023-07-03 | |
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ISSN | 0897-4756; 1520-5002 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 8.6 | Times cited | Open Access | OpenAccess | |
Notes | This project has received funding from the European Union's Horizon 2020 research and innovation program under Grant Agreement No. 766900 (Testing the large-scale limit of quantum mechanics). The authors thank Niranjan Saikumar for proof reading the manuscript. | Approved | Most recent IF: 8.6; 2023 IF: 9.466 | ||
Call Number | UA @ admin @ c:irua:197787 | Serial | 8907 | ||
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Author | van der Sluijs, M.M.; Salzmann, B.B.V.; Arenas Esteban, D.; Li, C.; Jannis, D.; Brafine, L.C.; Laning, T.D.; Reinders, J.W.C.; Hijmans, N.S.A.; Moes, J.R.; Verbeeck, J.; Bals, S.; Vanmaekelbergh, D. | ||||
Title | Study of the Mechanism and Increasing Crystallinity in the Self-Templated Growth of Ultrathin PbS Nanosheets | Type | A1 Journal article | ||
Year | 2023 | Publication | Chemistry of materials | Abbreviated Journal | |
Volume | Issue | Pages | |||
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Colloidal 2D semiconductor nanocrystals, the analogue of solid-state quantum wells, have attracted strong interest in material science and physics. Molar quantities of suspended quantum objects with spectrally pure absorption and emission can be synthesized. For the visible region, CdSe nanoplatelets with atomically precise thickness and tailorable emission have been (almost) perfected. For the near-infrared region, PbS nanosheets (NSs) hold strong promise, but the photoluminescence quantum yield is low and many questions on the crystallinity, atomic structure, intriguing rectangular shape, and formation mechanism remain to be answered. Here, we report on a detailed investigation of the PbS NSs prepared with a lead thiocyanate single source precursor. Atomically resolved HAADF-STEM imaging reveals the presence of defects and small cubic domains in the deformed orthorhombic PbS crystal lattice. Moreover, variations in thickness are observed in the NSs, but only in steps of 2 PbS monolayers. To study the reaction mechanism, a synthesis at a lower temperature allowed for the study of reaction intermediates. Specifically, we studied the evolution of pseudo-crystalline templates towards mature, crystalline PbS NSs. We propose a self-induced templating mechanism based on an oleylamine-lead-thiocyanate (OLAM-Pb-SCN) complex with two Pb-SCN units as a building block; the interactions between the long-chain ligands regulate the crystal structure and possibly the lateral dimensions. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000959572100001 | Publication Date | 2023-03-25 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.6 | Times cited | 2 | Open Access | OpenAccess |
Notes | H2020 Research Infrastructures, 731019 ; H2020 European Research Council, 692691 815128 ; Nederlandse Organisatie voor Wetenschappelijk Onderzoek, 715.016.002 ; | Approved | Most recent IF: 8.6; 2023 IF: 9.466 | ||
Call Number | EMAT @ emat @c:irua:195894 | Serial | 7255 | ||
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Author | Filez, M.; Feng, J.-Y.; Minjauw, M.M.; Solano, E.; Poonkottil, N.; Van Daele, M.; Ramachandran, R.K.; Li, C.; Bals, S.; Poelman, H.; Detavernier, C.; Dendooven, J.; Filez, M.; Minjauw, M.; Solano, E.; Poonkottil, N.; Li, C.; Bals, S.; Dendooven, J. | ||||
Title | Shuffling atomic layer deposition gas sequences to modulate bimetallic thin films and nanoparticle properties | Type | A1 Journal article | ||
Year | 2022 | Publication | Chemistry of materials | Abbreviated Journal | |
Volume | Issue | Pages | |||
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Atomic layer deposition (ALD) typically employs metal precursors and co-reactant pulses to deposit thin films in a layer-by-layer fashion. While conventional ABAB-type ALD sequences implement only two functionalities, namely, a metal source and ligand exchange agent, additional functionalities have emerged, including etching and reduction agents. Herein, we construct gas-phase sequences-coined as ALD+-with complex-ities reaching beyond the classic ABAB-type ALD by freely combining multiple functionalities within irregular pulse schemes, e.g., ABCADC. The possibilities of such combinations are explored as a smart strategy to tailor bimetallic thin films and nanoparticle (NP) properties. By doing so, we demonstrate that bimetallic thin films can be tailored with target thickness and through the full compositional range, while the morphology can be flexibly modulated from thin films to NPs by shuI 1ing the pulse sequence. These complex pulse schemes are expected to be broadly applicable but are here explored for Pd-Ru bimetallic thin films and NPs. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000823205700001 | Publication Date | 2022-06-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756; 1520-5002 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | Times cited | 2 | Open Access | OpenAccess | |
Notes | This research was funded by the Research Foundation, Flanders (FWO) , and the Special Research Fund BOF of Ghent University (GOA 01G01019) . M.F. and M.M.M. acknowledge the FWO for a postdoctoral research fellowship (1280621N) . N.P. acknowledges the European Union's Horizon 2020 research and innovation program under the Marie Skiodowska-Curie grant agreement no. 765378. For the GISAXS measurements, the author s received funding from the European Community's Transnational Access Program CALIPSOplus. E.S. acknowledges the Spanish project RTI2018-093996-B-C32 MICINN/FEDER funds. Air Liquide is acknowledged for supporting this research. The authors acknowledge SOLEIL for the provision of synchrotron radiation facilities and would like to thank Dr. Alessandro Coati for assistance in using beamline SiXS. The GIWAXS experiments were performed at NCD-SWEET beamline at ALBA Synchrotron with the collaboration of ALBA staff . | Approved | no | ||
Call Number | UA @ admin @ c:irua:189541 | Serial | 8928 | ||
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Author | Salzmann, B.B.V.; Vliem, J.F.; Maaskant, D.N.; Post, L.C.; Li, C.; Bals, S.; Vanmaekelbergh, D. | ||||
Title | From CdSe nanoplatelets to quantum rings by thermochemical edge reconfiguration | Type | A1 Journal article | ||
Year | 2021 | Publication | Chemistry Of Materials | Abbreviated Journal | Chem Mater |
Volume | 33 | Issue | 17 | Pages | 6853-6859 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The variation in the shape of colloidal semiconductor nanocrystals (NCs) remains intriguing. This interest goes beyond crystallography as the shape of the NC determines its energy levels and optoelectronic properties. While thermodynamic arguments point to a few or just a single shape(s), terminated by the most stable crystal facets, a remarkable variation in NC shape has been reported for many different compounds. For instance, for the well-studied case of CdSe, close-to-spherical quantum dots, rods, two-dimensional nanoplatelets, and quantum rings have been reported. Here, we report how two-dimensional CdSe nanoplatelets reshape into quantum rings. We monitor the reshaping in real time by combining atomically resolved structural characterization with optical absorption and photoluminescence spectroscopy. We observe that CdSe units leave the vertical sides of the edges and recrystallize on the top and bottom edges of the nanoplatelets, resulting in a thickening of the rims. The formation of a central hole, rendering the shape into a ring, only occurs at a more elevated temperature. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000696553600024 | Publication Date | 2021-08-24 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756; 1520-5002 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 7 | Open Access | OpenAccess |
Notes | Hans Meeldijk is kindly acknowledged for helping with electron microscopy at Utrecht University. B.B.V.S. and D.V. acknowledge the Dutch NWO for financial support via the TOP-ECHO grant no. 715.016.002. D.V. acknowledges financial support from the European ERC Council, ERC Advanced grant 692691 “First Step”. D.V. and L.C.P. acknowledge the Dutch NWO for financial support via the TOP-ECHO grant nr. 718.015.002. S.B acknowledges financial support from the European ERC Council, ERC Consolidator grant 815128. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement no. 731019 (EUSMI). Realnano; sygmaSB | Approved | Most recent IF: 9.466 | ||
Call Number | UA @ admin @ c:irua:181550 | Serial | 6839 | ||
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Author | Feng, H.L.; Kang, C.-J.; Manuel, P.; Orlandi, F.; Su, Y.; Chen, J.; Tsujimoto, Y.; Hadermann, J.; Kotliar, G.; Yamaura, K.; McCabe, E.E.; Greenblatt, M. | ||||
Title | Antiferromagnetic order breaks inversion symmetry in a metallic double perovskite, Pb₂NiOsO₆ | Type | A1 Journal article | ||
Year | 2021 | Publication | Chemistry Of Materials | Abbreviated Journal | Chem Mater |
Volume | 33 | Issue | 11 | Pages | 4188-4195 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A polycrystalline sample of Pb2NiOsO6 was synthesized under high-pressure (6 GPa) and high-temperature (1575 K) conditions. Pb2NiOsO6 crystallizes in a monoclinic double perovskite structure with a centrosymmetric space group P2(1)/n at room temperature. Pb2NiOsO6 is metallic down to 2 K and shows a single antiferromagnetic (AFM) transition at T-N = 58 K. Pb2NiOsO6 is a new example of a metallic and AFM oxide with three-dimensional connectivity. Neutron powder diffraction and first-principles calculation studies indicate that both Ni and Os moments are ordered below T-N and the AFM magnetic order breaks inversion symmetry. This loss of inversion symmetry driven by AFM order is unusual in metallic systems, and the 3d-Sd double-perovskite oxides represent a new class of noncentrosymmetric AFM metallic oxides. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000661521800032 | Publication Date | 2021-05-26 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756; 1520-5002 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | Open Access | OpenAccess | |
Notes | Approved | Most recent IF: 9.466 | |||
Call Number | UA @ admin @ c:irua:179679 | Serial | 6854 | ||
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Author | Imran, M.; Ramade, J.; Di Stasio, F.; De Franco, M.; Buha, J.; Van Aert, S.; Goldoni, L.; Lauciello, S.; Prato, M.; Infante, I.; Bals, S.; Manna, L. | ||||
Title | Alloy CsCdxPb1–xBr3Perovskite Nanocrystals: The Role of Surface Passivation in Preserving Composition and Blue Emission | Type | A1 Journal article | ||
Year | 2020 | Publication | Chemistry Of Materials | Abbreviated Journal | Chem Mater |
Volume | 32 | Issue | Pages | acs.chemmater.0c03825 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Various strategies have been proposed to engineer the band gap of metal halide perovskite nanocrystals (NCs) while preserving their structure and composition and thus ensuring spectral stability of the emission color. An aspect that has only been marginally investigated is how the type of surface passivation influences the structural/color stability of AMX3 perovskite NCs composed of two different M2+ cations. Here, we report the synthesis of blue-emitting Cs-oleate capped CsCdxPb1–xBr3 NCs, which exhibit a cubic perovskite phase containing Cd-rich domains of Ruddlesden–Popper phases (RP phases). The RP domains spontaneously transform into pure orthorhombic perovskite ones upon NC aging, and the emission color of the NCs shifts from blue to green over days. On the other hand, postsynthesis ligand exchange with various Cs-carboxylate or ammonium bromide salts, right after NC synthesis, provides monocrystalline NCs with cubic phase, highlighting the metastability of RP domains. When NCs are treated with Cs-carboxylates (including Cs-oleate), most of the Cd2+ ions are expelled from NCs upon aging, and the NCs phase evolves from cubic to orthorhombic and their emission color changes from blue to green. Instead, when NCs are coated with ammonium bromides, the loss of Cd2+ ions is suppressed and the NCs tend to retain their blue emission (both in colloidal dispersions and in electroluminescent devices), as well as their cubic phase, over time. The improved compositional and structural stability in the latter cases is ascribed to the saturation of surface vacancies, which may act as channels for the expulsion of Cd2+ ions from NCs. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000603288800034 | Publication Date | 2020-12-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.6 | Times cited | 44 | Open Access | OpenAccess |
Notes | European Commission; Fonds Wetenschappelijk Onderzoek, G.0267.18N ; H2020 European Research Council, 770887 815128 851794 ; We acknowledge funding from the FLAG-ERA JTC2019 project PeroGas. S.B., and S.V.A. acknowledges funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Consolidator Grants #815128REALNANO and #770887PICOMETRICS) and from the Research Foundation Flanders (FWO, Belgium) through project funding G.0267.18N. F.D.S. acknowledges the funding from ERC starting grant NANOLED (851794). The computational work was carried out on the Dutch National e-infrastructure with the support of the SURF Cooperative; sygma | Approved | Most recent IF: 8.6; 2020 IF: 9.466 | ||
Call Number | EMAT @ emat @c:irua:174004 | Serial | 6659 | ||
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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 | 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. | ||||
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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 | Rahemi, V.; Trashin, S.; Hafideddine, Z.; Van Doorslaer, S.; Meynen, V.; Gorton, L.; De Wael, K. | ||||
Title | Amperometric flow-injection analysis of phenols induced by reactive oxygen species generated under daylight irradiation of titania impregnated with horseradish peroxidase | Type | A1 Journal article | ||
Year | 2020 | Publication | Analytical Chemistry | Abbreviated Journal | Anal Chem |
Volume | 92 | Issue | 92 | Pages | 3643-3649 |
Keywords | A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | Titanium dioxide (TiO2) is a unique material for biosensing applications due to its capability of hosting enzymes. For the first time, we show that TiO2 can accumulate reactive oxygen species (ROS) under daylight irradiation and can support the catalytic cycle of horseradish peroxidase (HRP) without the need of H2O2 to be present in the solution. Phenolic compounds, such as hydroquinone (HQ) and 4-aminophenol (4-AP), were detected amperometrically in flow-injection analysis (FIA) mode via the use of an electrode modified with TiO2 impregnated with HRP. In contrast to the conventional detection scheme, no H2O2 was added to the analyte solution. Basically, the inherited ability of TiO2 to generate reactive oxygen species is used as a strategy to avoid adding H2O2 in the solution during the detection of phenolic compounds. Electron paramagnetic resonance (EPR) spectroscopy indicates the presence of ROS on titania which, in interaction with HRP, initiate the electrocatalysis toward phenolic compounds. The amperometric response to 4-AP was linear in the concentration range between 0.05 and 2 μM. The sensitivity was 0.51 A M–1 cm–2, and the limit of detection (LOD) 26 nM. The proposed sensor design opens new opportunities for the detection of phenolic traces by HRP-based electrochemical biosensors, yet in a more straightforward and sensitive way following green chemistry principles of avoiding the use of reactive and harmful chemical, such as H2O2. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000518234700023 | Publication Date | 2020-01-27 | |
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 | 7.4 | Times cited | 3 | Open Access | |
Notes | ; The authors thank Scientific Reseatch-Flanders (F-WO) (grant 12T4219N) for funding. ; | Approved | Most recent IF: 7.4; 2020 IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:166241 | Serial | 5463 | ||
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Author | De Jong, M.; Sleegers, N.; Florea, A.; Van Loon, J.; van Nuijs, A.L.N.; Samyn, N.; De Wael, K. | ||||
Title | Unraveling the mechanisms behind the complete suppression of cocaine electrochemical signals by chlorpromazine, promethazine, procaine, and dextromethorphan | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 24 | Pages | 15453-15460 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre; Product development | ||||
Abstract | The present work investigates the challenges accompanied by the electrochemical cocaine detection in physiological conditions (pH 7) in the presence of chlorpromazine, promethazine, procaine, and dextromethorphan, frequently used cutting agents in cocaine street samples. The problem translates into the absence of the cocaine oxidation signal (signal suppression) when in a mixture with one of these compounds, leading to false negative results. Although a solution to this problem was provided through earlier experiments of our group, the mechanisms behind the suppression are now fundamentally investigated via electrochemical and liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) strategies. The latter was used to confirm the passivation of the electrodes due to their interaction with promethazine and chlorpromazine. Electron transfer mechanisms were further identified via linear sweep voltammetry. Next, adsorption experiments were performed on the graphite screen printed electrodes both with and without potential assistance in order to confirm if the suppression of the cocaine signals is due to passivation induced by the cutting agents or their oxidized products. The proposed strategies allowed us to identify the mechanisms of cocaine suppression for each cutting agent mentioned. Suppression due to procaine and dextromethorphan is caused by fouling of the electrode surface by their oxidized forms, while for chlorpromazine and promethazine the suppression of the cocaine signal is related to the strong adsorption of these (nonoxidized) cutting agents onto the graphite electrode surface. These findings provide fundamental insights in possible suppression and other interfering mechanisms using electrochemistry in general not only in the drug detection sector. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000503910600018 | Publication Date | 2019-11-14 | |
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 | ||
Notes | ; The authors acknowledge financial support from IOF-SBO/POC (UAntwerp) and the Fund for Scientific Research (FWO) Flanders, Grant 1S 37658 17N. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:165727 | Serial | 5887 | ||
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Author | Florea, A.; Schram, J.; De Jong, M.; Eliaerts, J.; Van Durme, F.; Kaur, B.; Samyn, N.; De Wael, K. | ||||
Title | Electrochemical strategies for adulterated heroin samples | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 12 | Pages | 7920-7928 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | Electrochemical strategies to selectively detect heroin in street samples without the use of complicated electrode modifications were developed for the first time. For this purpose, heroin, mixing agents (adulterants, cutting agent, and impurities), and their binary mixtures were subjected to square wave voltammetry measurements at bare graphite electrodes at pH 7.0 and pH 12.0, in order to elucidate the unique electrochemical fingerprint of heroin and mixing agents as well as possible interferences or reciprocal influences. Adjusting the pH from pH 7.0 to pH 12.0 allowed a more accurate detection of heroin in the presence of most common mixing agents. Furthermore, the benefit of introducing a preconditioning step prior to running square wave voltammetry on the electrochemical fingerprint enrichment was explored. Mixtures of heroin with other drugs (cocaine, 3,4-methylenedioxymethamphetamine, and morphine) were also tested to explore the possibility of their discrimination and simultaneous detection. The feasibility of the proposed electrochemical strategies was tested on realistic heroin street samples from forensic cases, showing promising results for fast, on-site detection tools of drugs of abuse. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000472682000056 | Publication Date | 2019-05-30 | |
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 | 2 | Open Access | |
Notes | ; This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. The authors also acknowledge IOF (UAntwerp) and Belspo for financial support. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:160061 | Serial | 5596 | ||
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Author | Morales-Yanez, F.; Trashin, S.; Hermy, M.; Sariego, I.; Polman, K.; Muyldermans, S.; De Wael, K. | ||||
Title | Fast one-step ultrasensitive detection of toxocara canis antigens by a nanobody-based electrochemical magnetosensor | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 18 | Pages | 11582-11588 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | Human toxocariasis (HT) is a cosmopolitan zoonotic disease caused by the migration of the larval stage of the roundworm Toxocara canis. Current HT diagnostic methods do not discriminate between active and past infections. Here, we present a method to quantify Toxocara excretory/secretory antigen, aiming to identify active cases of HT. High specificity is achieved by employing nanobodies (Nbs), single domain antigen binding fragments from camelid heavy chain-only antibodies. High sensitivity is obtained by the design of an electrochemical magnetosensor with an amperometric read-out. Reliable detection of TES antigen at 10 and 30 pg/mL level was demonstrated in phosphate buffered saline and serum, respectively. Moreover, the assay showed no cross-reactivity with other nematode antigens. To our knowledge, this is the most sensitive method to quantify the TES antigen so far. It also has great potential to develop point of care diagnostic systems in other conditions where high sensitivity and specificity are required. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000487156900016 | Publication Date | 2019-08-20 | |
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 | 2 | Open Access | |
Notes | ; This project was funded by the Fonds Wetenschappelijk Onderzoek-Vlaanderen (FWO-Flanders, Project G.0189.13N) and BOF UAntwerp. The authors acknowledge Prof. Pierre Dorny (Institute of Tropical Medicine Antwerp) and Dr. Beatrice Nickel (Swiss Institute of Tropical Medicine) for providing the antigens needed for the cross-reactivity experiments. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:163784 | Serial | 5621 | ||
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Author | Vanmeert, F.; De Keyser, N.; van Loon, A.; Klaassen, L.; Noble, P.; Janssens, K. | ||||
Title | Transmission and reflection mode macroscopic x-ray powder diffraction imaging for the noninvasive visualization of paint degradation in still life paintings by Jan Davidsz. de Heem | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 11 | Pages | 7153-7161 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | The use of noninvasive chemical imaging techniques is becoming more widespread for the study of cultural heritage artifacts. Recently a mobile instrument for macroscopic X-ray powder diffraction (MA-XRPD) scanning was developed, which is capable of visualizing the distribution of crystalline (pigment) phases in quasi-flat-painted artifacts. In this study, MA-XRPD is used in both transmission and reflection mode for the analysis of three 17th century still life paintings, two paintings by Jan Davidsz. de Heem (1606-1684) and one copy painting after De Heem by an unknown artist. MA-XRPD allowed to reveal and map the presence of in situ-formed alteration products. In the works examined, two rare lead arsenate minerals, schultenite (PbHAsO4) and mimetite (Pb-5(AsO4)(3)Cl), were encountered, both at and below the paint surface; they are considered to be degradation products of the pigments realgar (alpha-As4S4) and orpiment (As2S3). In transmission mode, the depletion of lead white, present in the (second) ground layer, could be seen, illustrating the intrusive nature of this degradation process. In reflection mode, several sulfate salts, palmierite (K2Pb(SO4)(2)), syngenite (K2Ca(SO4)(2)center dot H2O), and gypsum (CaSO4 center dot 2H(2)O), could be detected, in particular, at the (top) surface of the copy painting. Estimates for the information depth and sensitivity of both transmission and reflection mode MA-XRPD for various pigments have been made. The possibility of MA-XRPD to allow for noninvasive identification and visualization of alteration products is considered a significant advantage and unique feature of this method. MA-XRPD can thus provide highly relevant information for assessing the conservation state of artworks and could guide possible future restoration treatments. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000470793800031 | Publication Date | 2019-05-10 | |
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 | 5 | Open Access | |
Notes | ; The authors acknowledge financial support from BELSPO (Brussels) S2-ART and METOX projects, the NWO (The Hague) Science4Arts “ReVisRembrandt” project, and the GOA Project Solarpaint (University of Antwerp Research Council). The authors thank the Rijksmuseum, the Royal Museum of Fine Arts Antwerp, and their staff for the collaborations. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:160245 | Serial | 5882 | ||
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Author | Sleegers, N.; van Nuijs, A.L.N.; van den Berg, M.; De Wael, K. | ||||
Title | Cephalosporin antibiotics : electrochemical fingerprints and core structure reactions investigated by LC-MSMS | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 3 | Pages | 2035-2041 |
Keywords | A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre | ||||
Abstract | Electrochemistry and exploiting electrochemical fingerprints is a potent approach to address newly emerging surveillance needs, for instance for antibiotics. However, a comprehensive insight in the electrochemical oxidation behaviour and mechanism is re-quired for this sensing strategy. To address the lack in knowledge of the voltammetric behaviour of the cephalosporins antibiotics, a selection of cephalosporin antibiotics and two main intermediates were subjected to an electrochemical study of their redox behaviour by means of pulsed voltammetric techniques and small-scale electrolysis combined with HPLC-MS/MS analyses. Sur-prisingly, the detected oxidation products did not fit the earlier suggested oxidation of the sulfur group to the corresponding sul-foxide. The influence of different side chains, both at the three and the seven position of the β-lactam core structure on the elec-trochemical fingerprint were investigated. Additional oxidation signals at lower potentials were elucidated and linked to different side chains. These signals were further exploited to allow simultaneous detection of different cephalosporins in one voltammetric sweep. These fundamental insights can become the building blocks for an new on-site screening method. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000458220300055 | Publication Date | 2019-01-03 | |
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 | 6 | Open Access | |
Notes | ; The authors acknowledge financial support from the Fund for Scientific Research (FWO) Flanders, Grant 1S 37658 17N. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:156046 | Serial | 5497 | ||
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Author | Gorbanev, Y.; Privat-Maldonado, A.; Bogaerts, A. | ||||
Title | Analysis of Short-Lived Reactive Species in Plasma–Air–Water Systems: The Dos and the Do Nots | Type | A1 Journal Article | ||
Year | 2018 | Publication | Analytical Chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 22 | Pages | 13151-13158 |
Keywords | A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | This Feature addresses the analysis of the reactive species generated by nonthermal atmospheric pressure plasmas, which are widely employed in industrial and biomedical research, as well as first clinical applications. We summarize the progress in detection of plasma-generated short-lived reactive oxygen and nitrogen species in aqueous solutions, discuss the potential and limitations of various analytical methods in plasma−liquid systems, and provide an outlook on the possible future research goals in development of short-lived reactive species analysis methods for a general nonspecialist audience. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000451246100002 | Publication Date | 2018-11-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 17 | Open Access | Not_Open_Access |
Notes | European Commission, 743151 ; This work was supported by the European Marie Sklodowska- Curie Individual Fellowship within Horizon2020 (“LTPAM”, Grant No. 743151). | Approved | Most recent IF: 6.32 | ||
Call Number | PLASMANT @ plasmant @c:irua:156301 | Serial | 5152 | ||
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Author | Fuchs, J.; Aghaei, M.; Schachel, T.D.; Sperling, M.; Bogaerts, A.; Karst, U. | ||||
Title | Impact of the Particle Diameter on Ion Cloud Formation from Gold Nanoparticles in ICPMS | Type | A1 Journal article | ||
Year | 2018 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 17 | Pages | 10271-10278 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | The unique capabilities of microsecond dwell time (DT) single-particle inductively coupled plasma mass spectrometry (spICPMS) were utilized to characterize the cloud of ions generated from the introduction of suspensions of gold nanoparticles (AuNPs) into the plasma. A set of narrowly distributed particles with diameters ranging from 15.4 to 100.1 nm was synthesized and characterized according to established protocols. Statistically significant numbers of the short transient spICPMS events were evaluated by using 50 μs DT for their summed intensity, maximum intensity, and duration, of which all three were found to depend on the particle diameter. The summed intensity increases from 10 to 1661 counts and the maximum intensity from 6 to 309 counts for AuNPs with diameters from 15.4 to 83.2 nm. The event duration rises from 322 to 1007 μs upon increasing AuNP diameter. These numbers represent a comprehensive set of key data points of the ion clouds generated in ICPMS from AuNPs. The extension of event duration is of high interest to appoint the maximum possible particle number concentration at which separation of consecutive events in spICPMS can still be achieved. Moreover, the combined evaluation of all above-mentioned ion cloud characteristics can explain the regularly observed prolonged single-particle events. The transport and ionization behavior of AuNPs in the ICP was also computationally modeled to gain insight into the size-dependent signal generation. The simulated data reveals that the plasma temperature, and therefore the point of ionization of the particles, is the same for all diameters. However, the maximum number density of Au+, as well as the extent of the ion cloud, depends on the particle diameter, in agreement with the experimental data, and it provides an adequate explanation for the observed ion cloud characteristics. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000444060600028 | Publication Date | 2018-09-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 5 | Open Access | OpenAccess |
Notes | We thank Dr. Harald Rösner from the Institute of Materials Physics of the University of Münster for the TEM imaging. | Approved | Most recent IF: 6.32 | ||
Call Number | PLASMANT @ plasmant @c:irua:153651 | Serial | 5057 | ||
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Author | De Jong, M.; Florea, A.; Eliaerts, J.; Van Durme, F.; Samyn, N.; De Wael, K. | ||||
Title | Tackling poor specificity of cocaine color tests by electrochemical strategies | Type | A1 Journal article | ||
Year | 2018 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 11 | Pages | 6811-6819 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | This paper presents electrochemical strategies for the fast screening of cocaine and most common cutting agents found in seized drug samples. First, a study on the performance of Scott color tests on cocaine and a wide range of cutting agents is described. The cutting agents causing false positive or false negative results when in mixture with cocaine are identified. To overcome the lack of specificity of color tests, we further propose a fast screening strategy by means of square wave voltammetry on disposable graphite screen printed electrodes, which reveals the unique fingerprint of cocaine and cutting agents. By employing a forward and backward scan and by a dual pH strategy, we enrich the electrochemical fingerprint and enable the simultaneous detection of cocaine and cutting agents. The effectiveness of the developed strategies was tested for the detection of cocaine in seized cocaine samples and compared with the color tests. Moreover, we prove the usefulness of square wave voltammetry for predicting possible interfering agents in color tests, based on the reduction peak of cobalt thiocyanate. The developed electrochemical strategies allow for a quick screening of seized cocaine samples resulting in a selective identification of drugs and cutting agents. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000434893200066 | Publication Date | 2018-05-09 | |
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 | 7 | Open Access | |
Notes | ; This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. This work was also supported by Grants BR/314 /PI/APTADRU and IOF-SBO. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:151316 | Serial | 5867 | ||
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Author | Vanmeert, F.; de Nolf, W.; Dik, J.; Janssens, K. | ||||
Title | Macroscopic X-ray powder diffraction scanning : possibilities for quantitative and depth-selective parchment analysis | Type | A1 Journal article | ||
Year | 2018 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 11 | Pages | 6445-6452 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | At or below the surface of painted works of art, valuable information is present that provides insights into an objects past, such as the artists technique and the creative process that was followed or its conservation history but also on its current state of preservation. Various noninvasive techniques have been developed over the past 2 decades that can probe this information either locally (via point analysis) or on a macroscopic scale (e.g., full-field imaging and raster scanning). Recently macroscopic X-ray powder diffraction (MA-XRPD) mapping using laboratory X-ray sources was developed. This method can visualize highly specific chemical distributions at the macroscale (dm(2)). In this work we demonstrate the synergy between the quantitative aspects of powder diffraction and the noninvasive scanning capability of MA-XRPD highlighting the potential of the method to reveal new types of information. Quantitative data derived from a 15th/16th century illuminated sheet of parchment revealed three lead white pigments with different hydrocerussite-cerussite compositions in specific pictorial elements, while quantification analysis of impurities in the blue azurite pigment revealed two distinct azurite types: one rich in barite and one in quartz. Furthermore, on the same artifact, the depth-selective possibilities of the method that stem from an exploitation of the shift of the measured diffraction peaks with respect to reference data are highlighted. The influence of different experimental parameters on the depth-selective analysis results is briefly discussed. Promising stratigraphic information could be obtained, even though the analysis is hampered by not completely understood variations in the unit cell dimensions of the crystalline pigment phases. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000434893200020 | Publication Date | 2018-04-06 | |
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 | 6 | Open Access | |
Notes | ; The authors thank Incoatec GmbH for giving us the opportunity to test the I mu S Cu X-ray source. We acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” project, and GOA Project Solarpaint (University of Antwerp Research Council). Photo Copyright Geert Van der Snickt, 2008 for the photograph of the illuminated manuscript in the TOC graphic. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:151994 | Serial | 5702 | ||
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Author | Vanmeert, F.; de Nolf, W.; De Meyer, S.; Dik, J.; Janssens, K. | ||||
Title | Macroscopic X-ray powder diffraction scanning, a new method for highly selective chemical imaging of works of art : instrument optimization | Type | A1 Journal article | ||
Year | 2018 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 11 | Pages | 6436-6444 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | In the past decade macroscopic X-ray fluorescence imaging (MA-XRF) has become established as a method for the noninvasive investigation of flat painted surfaces, yielding large scale elemental maps. MA-XRF is limited by a lack of specificity, only allowing for indirect pigment identification based on the simultaneous presence of chemical elements. The high specificity of X-ray powder diffraction (XRPD) mapping is already being exploited at synchrotron facilities for investigations at the (sub)microscopic scale, but the technique has not yet been employed using lab sources. In this paper we present the development of a novel MA-XRPD/XRF instrument based on a laboratory X-ray source. Several combinations of X-ray sources and area detectors are evaluated in terms of their spatial and angular resolution and their sensitivity. The highly specific imaging capability of the combined MA-XRPD/XRF instrument is demonstrated on a 15th/16th century illuminated manuscript directly revealing the distribution of a large number of inorganic pigments, including the uncommon yellow pigment massicot (o-PbO). The case study illustrates the wealth of new mapping information that can be obtained in a noninvasive manner using the laboratory MA-XRPD/XRF instrument. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000434893200019 | Publication Date | 2018-04-06 | |
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 | 11 | Open Access | |
Notes | ; The authors thank the persons involved at Incoatec GmbH, imXPAD SAS and Dectris Ltd. for loaning us some of their products over the past years. We acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” Project and GOA Project Solarpaint (University of Antwerp Research Council). Photo Copyright Geert Van der Snickt, 2008 for the photograph of the illuminated manuscript in the TOC graphic. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:151993 | Serial | 5701 | ||
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Author | De Jong, M.; Florea, A.; de Vries, A.-M.; van Nuijs, A.L.N.; Covaci, A.; Van Durme, F.; Martins, J.C.; Samyn, N.; De Wael, K. | ||||
Title | Levamisole : a common adulterant in cocaine street samples hindering electrochemical detection of cocaine | Type | A1 Journal article | ||
Year | 2018 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 8 | Pages | 5290-5297 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre | ||||
Abstract | The present work investigates the electrochemical determination of cocaine in the presence of levamisole, one of the most common adulterants found in cocaine street samples. Levamisole misleads cocaine color tests, giving a blue color (positive test) even in the absence of cocaine. Moreover, the electrochemical detection of cocaine is also affected by the presence of levamisole, with a suppression of the oxidation signal of cocaine. When levamisole is present in the sample in ratios higher than 1:1, the cocaine signal is no longer detected, thus leading to false negative results. Mass spectrometry and nuclear magnetic resonance were used to investigate if the signal suppression is due to the formation of a complex between cocaine and levamisole in bulk solution. Strategies to eliminate this suppressing effect are further suggested in this manuscript. In a first approach, the increase of the pH of the sample solution from pH 7 to pH 12 allowed the voltammetric determination of cocaine in the presence of levamisole in a concentration range from 10 to 5000 μM at nonmodified graphite disposable electrodes with a detection limit of 5 μM. In a second approach, the graphite electrode was cathodically pretreated, resulting in the presence of oxidation peaks of both cocaine and levamisole, with a detection limit for cocaine of 3 μM over the linear range of concentrations from 10 to 2500 μM. Both these strategies have been successfully applied for the simultaneous detection of cocaine and levamisole in three street samples on unmodified graphite disposable electrodes. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000430512200049 | Publication Date | 2018-02-23 | |
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 | 8 | Open Access | |
Notes | ; This project has received funding from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. This work was also supported by BR/314/PI/ APTADRU Project and IOF-SBO (UAntwerp). Alexander van Nuijs acknowledges the Research Foundation-Flanders (FWO) for his postdoctoral fellowship. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:149528 | Serial | 5693 | ||
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Author | Cagno, S.; Brede, D.A.; Nuyts, G.; Vanmeert, F.; Pacureanu, A.; Tucoulou, R.; Cloetens, P.; Falkenberg, G.; Janssens, K.; Salbu, B.; Lind, O.C. | ||||
Title | Combined computed nanotomography and nanoscopic x-ray fluorescence imaging of cobalt nanoparticles in caenorhabditis elegans | Type | A1 Journal article | ||
Year | 2017 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 89 | Issue | 21 | Pages | 11435-11442 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | Synchrotron radiation phase-contrast computed nanotomography (nano-CT) and two-and three-dimensional (2D and 3D) nanoscopic X-ray fluorescence (nano-XRF) were used to investigate the internal distribution of engineered-cobalt nanoparticles (Co NPs) in exposed individuals of the nematode Caenorhabditis elegans. Whole-nematodes and selected tissues and organs were 3D-rendered: anatomical 3D renderings with 50 nm voxel size enabled the visualization of spherical nanoparticle aggregates. with size tip to 200 nm within intact C. elegans. A 20 X 37 nm(2) high-brilliance beam was employed to obtain XRF elemental distribution maps of entire nematodes or anatomical details such as embryos, which could be compared with the CT data, These maps showed Co NPs to be predominantly present within the intestine and the epithelium, and they were not colocalized with Zn granules found in the lysosonie-containing vesicles or Fe agglomerates in the intestine. Iterated XRF scanning of a specimen at 0 degrees and 90 degrees angles suggested that NP aggregates were translocated into tissues outside of the intestinal lumen. Virtual-slicing by means of 2D XRF tomography, combined with holotomography, indicated presumable presence of individual NP aggregates inside the uterus and within embryos. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000414887000041 | Publication Date | 2017-10-10 | |
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 | 13 | Open Access | |
Notes | ; This study has been funded by the Norwegian Research Council through its Centre of Excellence (CoE) funding scheme (Project 223268/F50). We gratefully acknowledge ESRF and DESY for granting beamtime and Karl Andreas Jensen for performing ICPMS analysis. We thank Erica Maremonti for supplying the phase-contrast image used in Figure ^1A. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:147383 | Serial | 5520 | ||
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Author | Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K. | ||||
Title | Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings | Type | A1 Journal article | ||
Year | 2017 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 89 | Issue | 89 | Pages | 3326-3334 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken. | ||||
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Publisher | Place of Publication | Washington, D.C. | Editor | ||
Language | Wos | 000397478300015 | Publication Date | 2017-02-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 7 | Open Access | OpenAccess |
Notes | ; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government, department EWI. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ lucian @ c:irua:140886 | Serial | 4451 | ||
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