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Author Espinoza Torres, C.; Condó, A.M.; Haberkorn, N.; Zelaya, E.; Schryvers, D.; Guimpel, J.; Lovey, F.C.
Title Structures in textured Cu-Al-Ni shape memory thin films grown by sputtering Type A1 Journal article
Year 2014 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 96 Issue Pages 256-262
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The structure and texture formation in CuAlNi thin films of different thicknesses (1 μm to 5 μm) grown by DC magnetron sputtering without any intentional heating of the substrate are reported. The as-grown films present grains with an average size of 20 nm. The films with thickness of 1 μm have a single metastable phase with a hexagonal structure and are textured with planes (0002) parallel to the plane of the films. It was observed that thicker films present phase coexistence between metastable hexagonal and body centered cubic structures with a gradual increment of the body centered cubic phase fraction. The films with thickness of 5 μm are textured with planes (0002) and View the MathML source101¯0 in the hexagonal structure, whereas in the body centered cubic structure the films are textured with {110} planes parallel to the plane of the films. This fact can be associated with self-heating of the substrate during the growth of the films and with the relative stability of the metastable phases. Free standing films annealed in a second step (1123 K for 1 h) present austenitic phase with L21 structure and sub-micrometric grains textured with {220}L21 planes parallel to the plane of the films. The martensitic transformation temperature was determined from the analysis of resistance against temperature measurements.
Address
Corporate Author Thesis
Publisher Place of Publication New York Editor
Language Wos 000343346400032 Publication Date 2014-08-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.714 Times cited 9 Open Access
Notes (CONICET PIP 11220090100457) and MINCYT-FWO International Exchange Project FW/09/03 is also acknowledged Approved Most recent IF: 2.714; 2014 IF: 1.845
Call Number UA @ lucian @ c:irua:118931 Serial 3321
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Author Li, K.; Idrissi, H.; Sha, G.; Song, M.; Lu, J.; Shi, H.; Wang, W.; Ringer, S.P.; Du, Y.; Schryvers, D.
Title Quantitative measurement for the microstructural parameters of nano-precipitates in Al-Mg-Si-Cu alloys Type A1 Journal article
Year 2016 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 118 Issue 118 Pages 352-362
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Size, number density and volume fraction of nano-precipitates are important microstructural parameters controlling the strengthening of materials. In this work a widely accessible, convenient, moderately time efficient method with acceptable accuracy and precision has been provided for measurement of volume fraction of nano-precipitates in crystalline materials. The method is based on the traditional but highly accurate technique of measuring foil thickness via convergent beam electron diffraction. A new equation is proposed and verified with the aid of 3-dimensional atom probe (3DAP) analysis, to compensate for the additional error resulted from the hardly distinguishable contrast of too short incomplete precipitates cut by the foil surface. The method can be performed on a regular foil specimen with a modem LaB6 or field-emission-gun transmission electron microscope. Precisions around +/- 16% have been obtained for precipitate volume fractions of needle-like beta ''/C and Q precipitates in an aged Al-Mg-Si-Cu alloy. The measured number density is dose to that directly obtained using 3DAP analysis by a misfit of 45%, and the estimated precision for number density measurement is about +/- 11%. The limitations of the method are also discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000383292000042 Publication Date 2016-06-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.714 Times cited 9 Open Access
Notes This work is financially supported by National Natural Science Foundation of China (51501230 and 51531009) and Postdoctoral Science Foundation of Central South University (502042057). H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs under Contract No. P7/21 and FWO project G.0576.09N. Approved Most recent IF: 2.714
Call Number EMAT @ emat @ c:irua:137171 Serial 4334
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Author Pourbabak, S.; Montero-Sistiaga, M.L.; Schryvers, D.; Van Humbeeck, J.; Vanmeensel, K.
Title Microscopic investigation of as built and hot isostatic pressed Hastelloy X processed by Selective Laser Melting Type A1 Journal article
Year 2019 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 153 Issue Pages 366-371
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Microstructural characteristics of Hastelloy X produced by Selective Laser Melting have been investigated by various microscopic techniques in the as built (AB) condition and after hot isostatic pressing (HIP). At sub-grain level the AB material consists of columnar high density dislocation cells while the HIP sample consists of columnar sub-grains with lower dislocation density that originate from the original dislocation cells, contradicting existing models. The sub-grains contain nanoscale precipitates enriched in Al, Ti, Cr and O, located at sub-grain boundaries in the AB condition and within the grains after HIP. At some grain boundaries, micrometer sized chromium carbides are detected after HIP. Micro hardness within the grains was found to decrease after HIP, which was attributed to the decrease in dislocation density due to recovery annealing.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000472696900040 Publication Date 2019-05-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.714 Times cited 2 Open Access Not_Open_Access
Notes S.P. likes to thank the Flemish Science Foundation FWO for financial support under Project G.0366.15N. The authors acknowledge ENGIE Research and Technology Division for the use of the SLM280HL machine and financial support. This work was also made possible through the AUHA13009 grant “TopSPIN for TEM nanostatistics” of the Flemish HERCULES foundation. Approved Most recent IF: 2.714
Call Number EMAT @ emat @UA @ admin @ c:irua:159974 Serial 5178
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Author Charalampopoulou, E.; Lambrinou, K.; Van der Donck, T.; Paladino, B.; Di Fonzo, F.; Azina, C.; Eklund, P.; Mraz, S.; Schneider, J.M.; Schryvers, D.; Delville, R.
Title Early stages of dissolution corrosion in 316L and DIN 1.4970 austenitic stainless steels with and without anticorrosion coatings in static liquid lead-bismuth eutectic (LBE) at 500 degrees C Type A1 Journal article
Year 2021 Publication Materials Characterization Abbreviated Journal Mater Charact
Volume 178 Issue Pages 111234
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract This work addresses the early stages (<= 1000 h) of the dissolution corrosion behavior of 316L and DIN 1.4970 austenitic stainless steels in contact with oxygen-poor (C-O < 10(-8) mass%), static liquid lead-bismuth eutectic (LBE) at 500 degrees C for 600-1000 h. The objective of this study was to determine the relative early-stage resistance of the uncoated steels to dissolution corrosion and to assess the protectiveness of select candidate coatings (Cr2AlC, Al2O3, V2AlxCy). The simultaneous exposure of steels with intended differences in microstructure and thermomechanical state showed the effects of steel grain size, density of annealing/deformation twins, and secondary precipitates on the steel dissolution corrosion behavior. The findings of this study provide recommendations on steel manufacturing with the aim of using the steels to construct Gen-IV lead-cooled fast reactors.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000752582700001 Publication Date 2021-06-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.714 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 2.714
Call Number UA @ admin @ c:irua:186509 Serial 7061
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Author Krishnamurthy, S.C.; Arseenko, M.; Kashiwar, A.; Dufour, P.; Marchal, Y.; Delahaye, J.; Idrissi, H.; Pardoen, T.; Mertens, A.; Simar, A.
Title Controlled precipitation in a new Al-Mg-Sc alloy for enhanced corrosion behavior while maintaining the mechanical performance Type A1 Journal article
Year 2023 Publication Materials characterization Abbreviated Journal
Volume 200 Issue Pages 112886-11
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The hot working of 5xxx series alloys with Mg ≥3.5 wt% is a concern due to the precipitation of β (Al3Mg2) phase at grain boundaries favoring Inter Granular Corrosion (IGC). The mechanical and corrosion properties of a new 5028-H116 Al-Mg-Sc alloy under various β precipitates distribution is analyzed by imposing different cooling rates from the hot forming temperature (i.e. 325 °C). The mechanical properties are maintained regardless of the heat treatment. However, the different nucleation sites and volume fractions of β precipitates for different cooling rates critically affect IGC. Controlled furnace cooling after the 325 °C heat treatment is ideal in 5028-H116 alloy to reduce susceptibility to IGC after sensitization.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000977059100001 Publication Date 2023-04-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.7; 2023 IF: 2.714
Call Number UA @ admin @ c:irua:195598 Serial 7291
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Author Montero-Sistiaga, M.L.; Pourbabak, S.; Van Humbeeck, J.; Schryvers, D.; Vanmeensel, K.
Title Microstructure and mechanical properties of Hastelloy X produced by HP-SLM (high power selective laser melting) Type A1 Journal article
Year 2019 Publication Materials & design Abbreviated Journal Mater Design
Volume 165 Issue Pages 107598
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In order to increase the production rate during selective laser melting (SLM), a high power laser with a large beam diameter is used to build fully dense Hastelloy X parts. Compared to SLM with a low power and small diameter beam, the productivity was increased from 6 mm3/s to 16 mm3/s, i.e. 2.6 times faster. Besides the productivity benefit, the influence of the use of a high power laser on the rapid solidification microstructure and concomitant material properties is highlighted. The current paper compares the microstructure and tensile properties of Hastelloy X built with low and high power lasers. The use of a high power laser results in wider and shallower melt pools inducing an enhanced morphological and crystallographic texture along the building direction (BD). In addition, the increased heat input results in coarser sub-grains or high density dislocation walls for samples processed with a high power laser. Additionally, the influence of hot isostatic pressing (HIP) as a post-processing technique was evaluated. After HIP, the tensile fracture strain increased as compared to the strain in the as-built state and helped in obtaining competitive mechanical properties as compared to conventionally processed Hastelloy X parts.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000458259300020 Publication Date 2019-01-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0264-1275 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.364 Times cited 15 Open Access OpenAccess
Notes This research was supported by the ENGIE Research and Technology Division. The authors acknowledge ENGIE Research and Technology Division for the use of the SLM280HL machine. S.P. likes to thank the Flemish Science Foundation FWO for financial support under Project G.0366.15N. Approved Most recent IF: 4.364
Call Number EMAT @ emat @UA @ admin @ c:irua:157469 Serial 5176
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Author Bignoli, F.; Rashid, S.; Rossi, E.; Jaddi, S.; Djemia, P.; Terraneo, G.; Li Bassi, A.; Idrissi, H.; Pardoen, T.; Sebastiani, M.; Ghidelli, M.
Title Effect of annealing on mechanical properties and thermal stability of ZrCu/O nanocomposite amorphous films synthetized by pulsed laser deposition Type A1 Journal article
Year 2022 Publication Materials & design Abbreviated Journal Mater Design
Volume 221 Issue Pages 110972-10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Binary ZrCu nanocomposite amorphous films are synthetized by pulsed laser deposition (PLD) under vac-uum (2 x 10-3 Pa) and 10 Pa He pressure, leading to fully amorphous compact and nanogranular mor-phologies, respectively. Then, post-thermal annealing treatments are carried out to explore thermal stability and crystallization phenomena together with the evolution of mechanical properties. Compact films exhibit larger thermal stability with partial crystallization phenomena starting at 420 degrees C, still to be completed at 550 degrees C, while nanogranular films exhibit early-stage crystallization at 300 degrees C and com-pleted at 485 degrees C. The microstructural differences are related to a distinct evolution of mechanical
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000886072100004 Publication Date 2022-07-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0264-1275; 1873-4197 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.4 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 8.4
Call Number UA @ admin @ c:irua:192194 Serial 7299
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Author Kashiwar, A.; Arseenko, M.; Simar, A.; Idrissi, H.
Title On the role of microstructural defects on precipitation, damage, and healing behavior in a novel Al-0.5Mg2Si alloy Type A1 Journal article
Year 2024 Publication Materials & design Abbreviated Journal
Volume 239 Issue Pages 112765-112769
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A recently developed healable Al-Mg2Si designed by the programmed damage and repair (PDR) strategy is studied considering the role microstructural defects play on precipitation, damage, and healing. The alloy incorporates sacrificial Mg2Si particles that precipitate after friction stir processing (FSP). They act as damage localization sites and are healable based on the solid-state diffusion of Al-matrix. A combination of different transmission electron microscopy (TEM) imaging techniques enabled the visualization and quantification of various crystallographic defects and the spatial distribution of Mg2Si precipitates. Intragrain nucleation is found to be the dominant mechanism for precipitation during FSP whereas grain boundaries and subgrain boundaries mainly lead to coarsening of the precipitates. The statistical and spatial analyses of the damaged particles have shown particle fracture as the dominant damage mechanism which is strongly dependent on the size and aspect ratio of the particles whereas the damage was not found to depend on the location of the precipitates within the matrix. The damaged particles are associated with dislocations accumulated around them. The interplay of these dislocations is directly visualized during healing based on in situ TEM heating which revealed recovery in the matrix as an operative mechanism during the diffusion healing of the PDR alloy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001194110200001 Publication Date 2024-02-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0264-1275; 1873-4197 ISBN Additional Links UA library record; WoS full record
Impact Factor 8.4 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 8.4; 2024 IF: 4.364
Call Number UA @ admin @ c:irua:203298 Serial 9068
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Author Kumar, M.; Sengupta, A.; Kummamuru, N.B.
Title Molecular simulations for carbon dioxide capture in silica slit pores Type A3 Journal article
Year 2023 Publication Materials Today: Proceedings Abbreviated Journal
Volume Issue Pages 1-9
Keywords A3 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In present work, we have performed the Grand Canonical Monte Carlo (GCMC) simulations to quantify CO2 capture inside porous silica at high operating temperatures of 673.15 K and 873.15 K; and over a operating pressure range of 500 kPa – 4000 kPa that are methane steam reforming process parameters. Related chemical potential values at these thermodynamic conditions are obtained from the bulk phase simulations in the Canonical ensemble in conjunction with Widom’s insertion technique, where the CO2 has been accurately represented by TraPPE force field. Present structure of the porous silica is a single slit pore geometry of various heights (H = 20 Å, 31.6 Å, 63.2 Å and 126.5 Å), dimensions in which possible vapour-liquid equilibria for generic square well fluids has been reported in literature. Estimation of the pore-fluid interactions show a higher interaction between silica pore and adsorbed CO2 compared to the reported pore-fluid interactions between homogeneous carbon slit pore and adsorbed CO2; thus resulting in an enhancement of adsorption inside silica pores of H = 20 Å and H = 126.5 Å, which are respectively 3.5 times and 1.5 times higher than that in homogeneous carbon slit pores of same dimensions and at 673.15 K and 500 kPa. Estimated local density plots indicate the presence of structured layers due to more molecular packing, which confirms possible liquid-like and vapour-like phase coexistence of the supercritical bulk phase CO2 under confinement.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2023-05-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2214-7853 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:200944 Serial 9058
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Author Sun, M.-H.; Zhou, J.; Hu, Z.-Y.; Chen, L.-H.; Li, L.-Y.; Wang, Y.-D.; Xie, Z.-K.; Turner, S.; Van Tendeloo, G.; Hasan, T.; Su, B.-L.
Title Hierarchical zeolite single-crystal reactor for excellent catalytic efficiency Type A1 Journal article
Year 2020 Publication Matter Abbreviated Journal
Volume 3 Issue 4 Pages 1226-1245
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract As a size- and shape-selective catalyst, zeolites are widely used in petroleum and fine-chemicals processing. However, their small micropores severely hinder molecular diffusion and are sensitive to coke formation. Hierarchically porous zeolite single crystals with fully interconnected, ordered, and tunable multimodal porosity at macro-, meso-, and microlength scale, like in leaves, offer the ideal solution. However, their synthesis remains highly challenging. Here, we report a versatile confined zeolite crystallization process to achieve these superior properties. Such zeolite single crystals lead to significantly improved mass transport properties by shortening the diffusion length while maintaining shape-selective properties, endowing them with a high efficiency of zeolite crystals, enhanced catalytic activities and lifetime, highly reduced coke formation, and reduced deactivation rate in bulky-molecule reactions and methanol-to-olefins process. Their industrial utilization can lead to the design of innovative and intensified reactors and processes with highly enhanced efficiency and minimum energy consumption.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000581132600021 Publication Date 2020-08-12
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 Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:174329 Serial 6727
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Author Van Goethem, C.; Verbeke, R.; Pfanmoeller, M.; Koschine, T.; Dickmann, M.; Timpel-Lindner, T.; Egger, W.; Bals, S.; Vankelecom, I.F.J.
Title The role of MOFs in Thin-Film Nanocomposite (TFN) membranes Type A1 Journal article
Year 2018 Publication Journal of membrane science Abbreviated Journal J Membrane Sci
Volume 563 Issue 563 Pages 938-948
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Incorporation of MOFs in interfacially polymerized Thin-Film Nanocomposite (TFN) membranes has widely been shown to result in increased membrane performance. However, the exact functioning of these membranes is poorly understood as large variability in permeance increase, filler incorporation and rejection changes can be observed in literature. The synthesis and functioning of TFN membranes (herein exemplified by ZIF-8 filled polyamide (PA) membranes prepared via the EFP method) was investigated via targeted membrane synthesis and thorough characterization via STEM-EDX, XRD and PALS. It is hypothesized that the acid generated during the interfacial polymerization (IP) at least partially degrades the crystalline, acid-sensitive ZIF-8 and that this influences the membrane formation (through so-called secondary effects, i.e. not strictly linked to the pore morphology of the MOF). Nanoscale HAADF-STEM imaging and STEM-EDX Zn-mapping revealed no ZIF-8 particles but rather the presence of randomly shaped regions with elevated Zn-content. Also XRD failed to show the presence of crystalline areas in the composite PA films. As the addition of the acid-quenching TEA led to an increase in the diffraction signal observed in XRD, the role of the acid was confirmed. The separate addition of dissolved Zn2+ to the synthesis of regular TFC membranes showed an increase in permeance while losing some salt retention, similar to observations regularly made for TFN membranes. While the addition of a porous material to a TFC membrane is a straightforward concept, all obtained results indicate that the synthesis and performance of such composite membranes is often more complex than commonly accepted.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000441897200099 Publication Date 2018-06-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0376-7388 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.035 Times cited 84 Open Access OpenAccess
Notes ; C.V.G. and R.V. kindly acknowledge respectively the Flemish Agency for Innovation through Science and Technology (IWT) (IWT, 141697) and the Flemish Fund for Scientific Research (FWO, 1500917N) for a PhD scholarship. The authors kindly acknowledge funding from KU Leuven through C16/17/005 and from the Belgian Federal Government through IAP 6/27 Functional Supramolecular systems. S.B. and M.P. acknowledge financial support from the European Research Council (ERC Starting Grant #335078-COLOURATOM). M.P. acknowledges funding from the European Union (ESTEEM2, No. 312483) and the HEiKA centre FunTECH-3D (Ministry of Science, Research and Art Baden-Wurttemberg, AZ: 33-753-30-20/3/3). The MLZ-Garching is kindly acknowledged for providing access to the NEPOMUC facilities (project no 11541). ; ecas_sara Approved Most recent IF: 6.035
Call Number UA @ lucian @ c:irua:153618UA @ admin @ c:irua:153618 Serial 5132
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Author Monico, L.; Janssens, K.; Cotte, M.; Sorace, L.; Vanmeert, F.; Brunetti, B.G.; Miliani, C.
Title Chromium speciation methods and infrared spectroscopy for studying the chemical reactivity of lead chromate-based pigments in oil medium Type A1 Journal article
Year 2016 Publication Microchemical journal T2 – TECHNART Conference, APR 27-30, 2015, Catania, ITALY Abbreviated Journal Microchem J
Volume 124 Issue Pages 272-282
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Environmental factors, such as light, humidity and temperature are triggering agents for the alteration of organic and/or inorganic constituents of oil paintings. The oxidation of the organic material is favored by increasing of relative humidity and temperature, whereas processes involving changes of the oxidation states of a number of inorganic pigments (e.g., vermilion, cadmium yellows, zinc yellows, chrome yellows) are mainly activated by light-exposure. In view of the optimization of the long-term conservation and restoration strategies of paintings it is of relevant interest to establish the consequences of thermal parameters (temperature and relative humidity) on the chemical/photochemical-reactivity and the nature of the alteration products of light sensitive-pigments in oil medium. To this aim here we propose a multi-method analytical approach based on the combination of diffuse reflectance UV-Vis, FTIR, synchrotron radiation (SR)-based micro X-ray fluorescence (mu-XRF)/micro-X-ray absorption neat edge structure ()CANES) and electron paramagnetic resonance (EPR) spectroscopies for studying the effects of different relative humidity conditions before and after light exposure on the reactivity of a series of lead chromate-based pigments [such as PbCrO4 center dot PbO (monoclinic), PbCrO4 (monoclinic) and PbCr0.2S0.8O4 (orthorhombic)] in an oil medium. The investigation of paint models was also compared to that of a late 19th century historical orthorhombic PbCr0.4S0.6O4 oil paint. Diffuse reflectance UV-Vis and FTIR spectroscopies were used to obtain information associated with chromatic changes and the formation of organo-metal degradation products at the paint surface. SR-based Cr K-edge mu-XANES/mu-XRF mapping analysis and EPR spectroscopy were employed in a complementary fashion to determine the amount, nature and distribution of Cr(III) and Cr(V)-based alteration compounds within the paints with micrometric spatial resolution. Under the employed thermal aging conditions, lead(II)-carboxylates and reduced Cr-compounds (in abundance of up to about 35% at the surface) have been identified in the lead chromate-based paints. The tendency of chromates to become reduced increased with increasing moisture levels and was favored for the orthorhombic PbCr0.2S0.8O4 compounds. The redox process gave rise to the formation of Cr(V)-species in relative amount much higher than that was formed in the equivalent paint which was exposed only to light. After light-exposure of the thermally aged paints, compounds ascribable to the oxidation of the organic binder were detected for all the types of pigments. Nevertheless, the previous thermal treatment increased the tendency toward photo-reduction of only the PbCr0.2S0.8O4 pigment. For this light-sensitive compound, the thickness variation of the reduced Cr-rich (ca. 70%) photo-alteration layer with moisture levels could be ascribed to a surface passivation phenomenon that had already occurred before photochemical aging. (C) 2015 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000367755600042 Publication Date 2015-09-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-265x; 0026-265x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.034 Times cited 23 Open Access
Notes ; ; Approved Most recent IF: 3.034
Call Number UA @ admin @ c:irua:131099 Serial 5519
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Author Vermeulen, M.; Janssens, K.; Sanyova, J.; Rahemi, V.; McGlinchey, C.; De Wael, K.
Title Assessing the stability of arsenic sulfide pigments and influence of the binding media on their degradation by means of spectroscopic and electrochemical techniques Type A1 Journal article
Year 2018 Publication Microchemical journal Abbreviated Journal Microchem J
Volume 138 Issue 138 Pages 82-91
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract In this paper, we used the semiconducting and lightfastness properties of synthetic and mineral arsenic sulfide pigments to study their stability by means of electrochemical and microfadometric techniques. A combination of these techniques shows that in the early stage of the degradation process, amorphous arsenic sulfides are more stable than both crystalline forms, while upon longer exposure time, amorphous pigments will fade more than both mineral pigments, making it less suitable. While the stability study was carried out on unbound pigments, the influence of the organic binder on the relative degradation of the arsenic sulfide pigments was investigated through a multi-analytical approach on pigment/binder mock-up paint samples. For this purpose, the formation of arsenic trioxide was assessed by micro Fourier transform infrared (μ-FTIR) spectroscopy while the influence of the binder on the formation of sulfates was studied by means of synchrotron radiation X-ray near edge structure (μ-XANES). Both techniques elucidate a higher stability of all pigments in gum arabic while the use of egg yolk as binder leads to the most degradation, most likely due to its sulfur-rich composition. In the context of the degradation of arsenic sulfide pigments, other binders such as animal glue, egg white or linseed oil show an intermediate impact.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000428103000010 Publication Date 2018-01-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-265x; 0026-265x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.034 Times cited 4 Open Access
Notes ; This research is made possible with the support of the Belgian Science Policy Office (BELSPO, Brussels) through the research program Science for a Sustainable Development – SDD, “Long-term role and fate of metal-sulfides in painted works of art – S2ART” (grant number SD/RI/04A). We gratefully acknowledge Megane Willems (Institut Paul-Lambin) for her help with mu-FFIR analyses and realization of the mock-up paint samples. We acknowledge the Paul Scherrer Institut, Villigen, Switzerland for provision of synchrotron radiation beamtime at beamline Phoenix of the SLS. ; Approved Most recent IF: 3.034
Call Number UA @ admin @ c:irua:150149 Serial 5482
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Author Schram, J.; Parrilla, M.; Slosse, A.; Van Durme, F.; Åberg, J.; Björk, K.; Bijvoets, S.M.; Sap, S.; Heerschop, M.W.J.; De Wael, K.
Title Paraformaldehyde-coated electrochemical sensor for improved on-site detection of amphetamine in street samples Type A1 Journal article
Year 2022 Publication Microchemical journal Abbreviated Journal
Volume 179 Issue Pages 107518-107519
Keywords A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Abstract The increasing illicit production, distribution and abuse of amphetamine (AMP) poses a challenge for law enforcement worldwide. To effectively combat this issue, fast and portable tools for the on-site screening of suspicious samples are required. Electrochemical profile (EP)-based sensing of illicit drugs has proven to be a viable option for this purpose as it allows rapid voltammetric measurements via the use of disposable and low-cost graphite screen-printed electrodes (SPEs). In this work, a highly practical paraformaldehyde (PFA)-coated sensor, which unlocks the detectability of primary amines through derivatization, is developed for the on-site detection of AMP in seized drug samples. A potential interval was defined at the sole AMP peak (which is used for identification of the target analyte) to account for potential shifts due to fluctuations in concentration and temperature, which are relevant factors for on-site use. Importantly, it was found that AMP detection was not hindered by the presence of common diluents and adulterants such as caffeine, even when present in high amounts. When inter-drug differentiation is desired, a simultaneous second test with the same solution on an unmodified electrode is introduced to provide the required additional electrochemical information. Finally, the concept was validated by analyzing 30 seized AMP samples (reaching a sensitivity of 96.7 %) and comparing its performance to that of commercially available Raman and Fourier Transform Infrared (FTIR) devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000809675500010 Publication Date 2022-04-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-265x; 0026-265x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access OpenAccess
Notes Approved no
Call Number UA @ admin @ c:irua:188454 Serial 8910
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Author Van Echelpoel, R.; Parrilla, M.; Sleegers, N.; Thiruvottriyur Shanmugam, S.; van Nuijs, A.L.N.; Slosse, A.; Van Durme, F.; De Wael, K.
Title Validated portable device for the qualitative and quantitative electrochemical detection of MDMA ready for on-site use Type A1 Journal article
Year 2023 Publication Microchemical journal Abbreviated Journal
Volume 190 Issue Pages 108693-10
Keywords A1 Journal article; Engineering sciences. Technology; Toxicological Centre; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Abstract Identifying and quantifying 3,4-methyl​enedioxy​methamphetamine (MDMA) on-site in suspected illicit drug samples, whether it be at recreational settings or manufacturing sites, is a major challenge for law enforcement agencies (LEAs). Various analytical techniques exist to fulfil this goal, e.g. colourimetry and portable spectroscopic techniques, each having its specific limitations (e.g. low accuracy, fluorescence, no quantification) and strengths (e.g. fast, easy to use). In this work, for the first time, an electrochemical MDMA sensor is presented to become a detection tool that can realistically be used on-site. More specifically, the use of a single buffer solution and an unmodified screen-printed electrode, along with the integration of a data analysis algorithm and mobile application permits the straightforward on-site identification and quantification of MDMA in suspicious samples. Multiple studies investigating different parameters, including pH, concentration, reproducibility, temperature and binary mixture analyses, were executed. To fully understand all the occurring redox processes, liquid chromatography coupled with high-resolution mass spectrometry analysis of partially electrolyzed MDMA samples was performed unravelling oxidation of the methylenedioxy group. Validation of the methodology was executed on 15 MDMA street samples analysed by gas chromatography coupled with mass spectrometry and compared with the performance of a commercial portable Raman and Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) device. The novel methodology outperformed the spectroscopic techniques, correctly identifying all 15 street samples. Additionally, the electrochemical sensor predicted the purity of the tablets with a mean absolute error of 2.3%. Overall, this new, electrochemical detection strategy provides LEAs the rapid, low-cost, on-site detection and quantification of MDMA in suspicious samples, without requiring specialized training.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000977060400001 Publication Date 2023-03-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-265x; 0026-265x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.8 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.8; 2023 IF: 3.034
Call Number UA @ admin @ c:irua:195415 Serial 8952
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Author Drăgan, A.-M.; Parrilla, M.; Cambré, S.; Domínguez-Robles, J.; Detamornrat, U.; Donnelly, R.F.; Oprean, R.; Cristea, C.; De Wael, K.
Title Microneedle array-based electrochemical sensor functionalized with SWCNTs for the highly sensitive monitoring of MDMA in interstitial fluid Type A1 Journal article
Year 2023 Publication Microchemical journal Abbreviated Journal
Volume 193 Issue Pages 109257-11
Keywords A1 Journal article; Pharmacology. Therapy; Nanostructured and organic optical and electronic materials (NANOrOPT); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Abstract Illicit drug consumption constitutes a great concern worldwide due to its increased spread and abuse, and the negative consequences exerted on society. For instance, 3,4-methylenedioxymethamphetamine (MDMA), a synthetic amphetamine-type substance, was abused by 20 million people worldwide in 2020. This psychoactive substance exerts a myriad of effects on the human body being dangerous for the consumer’s health. Besides, MDMA has been used in the treatment of some psychiatric conditions. Therefore, the development of wearable devices for MDMA sensing in biological fluids is of great importance for forensic toxicology (e.g., monitoring of patients with suspected or known MDMA consumption) as well as for therapeutic management of patients. Herein, we report the development of a wearable electrochemical platform based on a hollow microneedle (MN) array sensor for the monitoring of MDMA in the interstitial fluid by square-wave voltammetry. First, the holes of the MN array were modified with conductive pastes to devise a MN patch with a three-electrode system. Subsequently, the functionalization of the working electrode with nanomaterials enhanced MDMA detection. Thereafter, analytical parameters were evaluated exhibiting a slope of 0.05 µA µM−1 within a linear range from 1 to 50 µM and a limit of detection of 0.75 µM in artificial interstitial fluid. Importantly, critical parameters such as selectivity, piercing capability, temperature, reversibility and stability were assessed. Overall, the obtained MN sensor exhibited excellent analytical performance, making it a promising tool for MDMA tracking in interstitial fluid for individuals on probation or under therapeutic treatment.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001067945900001 Publication Date 2023-08-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-265x; 0026-265x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.8 Times cited Open Access Not_Open_Access: Available from 27.02.2024
Notes Approved Most recent IF: 4.8; 2023 IF: 3.034
Call Number UA @ admin @ c:irua:198183 Serial 8898
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Author van Oers, C.J.; Kurttepeli, M.; Mertens, M.; Bals, S.; Meynen, V.; Cool, P.
Title Zeolite \beta nanoparticles based bimodal structures : mechanism and tuning of the porosity and zeolitic properties Type A1 Journal article
Year 2014 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 185 Issue Pages 204-212
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract Despite great efforts in the research area of zeolite nanoparticles and their use in the synthesis of bimodal materials, still little is known about the impact of the synthesis conditions of the zeolite nanoparticles on its own characteristics, and on the properties and the formation mechanism of the final bimodal materials. A zeolite β nanoparticles solution is applied in a mesotemplate-free synthesis method, and the influence of the hydrothermal ageing temperature of the nanoparticles solution on both the zeolitic and porosity characteristics of the final bimodal material has been studied. Transmission electron microscopy in combination with 3-dimensional reconstructions obtained by electron tomography revealed that the zeolite β nanoparticles are connected by neck-like structures, thus creating a wormhole-like mesoporous material. Considering the zeolitic properties, a clear threshold is observed in the synthesis temperature series at 413 K. Below and at this threshold, the biporous materials show no apparent zeolitic characteristics, although these materials exhibit a more condensed and uniform SiOSi network in comparison to Al-MCF. Synthesis temperatures above the threshold lead to bimodal structures with defined zeolitic properties. Moreover, the dimensions of the nanoparticles are studied by TEM, revealing an increasing particle size with increasing temperature under the threshold of 413 K, which is in agreement with a sol-mechanism. This mechanism is disturbed after the threshold due to the start of the crystallisation process.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000330930400025 Publication Date 2013-11-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 10 Open Access OpenAccess
Notes 262348 Esmi Approved Most recent IF: 3.615; 2014 IF: 3.453
Call Number UA @ lucian @ c:irua:112501 Serial 3930
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Author Lin, F.; Meng, X.; Kukueva, E.; Kus, M.; Mertens, M.; Bals, S.; Van Doorslaer, S.; Cool, P.
Title Novel method to synthesize highly ordered ethane-bridged PMOs under mild acidic conditions : taking advantages of phosphoric acid Type A1 Journal article
Year 2015 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 207 Issue 207 Pages 61-70
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract Highly ordered SBA-15-type ethane-bridged PMOs have been obtained by employing H3PO4 as acid to tune the pH in the presence of copolymer surfactant P123. The effects of the acidity and the addition of inorganic salt on the formation of the mesostructure are investigated. It is found that, compared with HCl, the polyprotic weak acid H3PO4 is preferable for the synthesis of highly ordered SBA-15-type ethane-bridged PMOs with larger pore size and surface areas under mild acidic conditions. Moreover, taking the advantages of the mild acidic condition, vanadium-containing SBA-15-type ethane-bridged PMOs were successfully prepared through a direct synthesis approach. The XRD, N2-sorption, UVVis and CW-EPR studies of the V-PMO show that part of the vanadium species are present in polymeric (VOV)n clusters, while part of the vanadium centers are well-dispersed and immobilized on the inner surface of the mesopores.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000350518600009 Publication Date 2015-01-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 5 Open Access OpenAccess
Notes ; The Erasmus Mundus CONNEC program is acknowledged for PhD funding of F.Lin. Furthermore, the authors acknowledge support by the GOA-BOF project 'Optimization of the structure-activity relation in nanoporous materials', funded by the University of Antwerp. ; Approved Most recent IF: 3.615; 2015 IF: 3.453
Call Number c:irua:123910 Serial 2379
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Author Filippousi, M.; Turner, S.; Katsikini, M.; Pinakidou, F.; Zamboulis, D.; Pavlidou, E.; Van Tendeloo, G.
Title Direct observation and structural characterization of natural and metal ion-exchanged HEU-type zeolites Type A1 Journal article
Year 2015 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 210 Issue 210 Pages 185-193
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The atomic structure of natural HEU-type zeolite and two ion-exchanged variants of the zeolite, Ag+ (Ag-HEU) and Zn2+ (Zn-HEU) ion exchanged HEU-type zeolites, are investigated using advanced transmission electron microscopy techniques in combination with X-ray powder diffraction and X-ray absorption fine structure measurements. In both ion-exchanged materials, loading of the natural HEU zeolite is confirmed. Using low-voltage, aberration-corrected transmission electron microscopy at low-dose conditions, the local crystal structure of natural HEU-type zeolite is determined and the interaction of the ion-exchanged natural zeolites with the Ag+ and Zn2+ ions is studied. In the case of Ag-HEU, the presence of Ag+ ions and clusters at extra-framework sites as well as Ag nanoparticles has been confirmed. The Ag nanoparticles are preferentially positioned at the zeolite surface. For Zn-HEU, no large Zn(O) nanopartides are present, instead, the HEU channels are evidenced to be decorated by small Zn(O) clusters. (c) 2015 Elsevier Inc. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000353733300024 Publication Date 2015-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 5 Open Access
Notes 246791 Countatoms; Iap-Pai; Fwo Approved Most recent IF: 3.615; 2015 IF: 3.453
Call Number c:irua:126006 Serial 715
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Author Kurttepeli, M.; Locus, R.; Verboekend, D.; de Clippel, F.; Breynaert, E.; Martens, J.; Sels, B.; Bals, S.
Title Synthesis of aluminum-containing hierarchical mesoporous materials with columnar mesopore ordering by evaporation induced self assembly Type A1 Journal article
Year 2016 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 234 Issue 234 Pages 186-195
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The incorporation of aluminum into the silica columns of hierarchical mesoporous materials (HMMs) was studied. The HMMs were synthesized by a combination of hard and soft templating methods, forming mesoporous SBA-15-type silica columns inside the pores of anodic aluminum oxide membranes via evaporation induced self-assembly (EISA). By adding Al-isopropoxide to the EISA-mixture a full tetrahedral incorporation of Al and thus the creation of acid sites was achieved, which was proved by nuclear magnetic resonance spectroscopy. Electron microscopy showed that the use of Al-isopropoxide as an Al source for the HMMs led to a change in the mesopore ordering of silica material from circular hexagonal (donut-like) to columnar hexagonal and a 37% increase in specific surface (BET surface). These results were confirmed by a combination of nitrogen physisorption and small-angle X-ray scattering experiments and can be attributed to a swelling of the P123 micelles with isopropanol. The columnar mesopore ordering of silica is advantageous towards the pore accessibility and therefore preferential for many possible applications including catalysis and adsorption on the acid tetrahedral Al-sites. (C) 2016 Elsevier Inc. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000383291400020 Publication Date 2016-07-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 5 Open Access OpenAccess
Notes ; The Belgian government (Belgian Science Policy Office, Belspo) is acknowledged for financing the Interuniversity Attraction Poles (IAP-PAI). S. B. acknowledges the financial support from the European Research Council (ERC Starting Grant #335078-COLOURATOMS). D. V. acknowledges the Flanders Research Foundation (FWO). ; ecas_Sara Approved Most recent IF: 3.615
Call Number UA @ lucian @ c:irua:137108 Serial 4404
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Author Huybrechts, W.; Mali, G.; Kuśtrowski, P.; Willhammar, T.; Mertens, M.; Bals, S.; Van Der Voort, P.; Cool, P.
Title Post-synthesis bromination of benzene bridged PMO as a way to create a high potential hybrid material Type A1 Journal article
Year 2016 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 236 Issue 236 Pages 244-249
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract Periodic mesoporous organosilicas provide the best of two worlds: the strength and porosity of an inorganic framework combined with the infinite possibilities created by the organic bridging unit. In this work we focus on post-synthetical modification of benzene bridged PMO, in order to create bromobenzene PMO. In the past, this proved to be very challenging due to unwanted structural deterioration. However, now we have found a way to brominate this material whilst keeping the structure intact. In-depth structural analysis by solid state NMR and XPS shows both vast progress over previous attempts as well as potential for improvement.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000385899600028 Publication Date 2016-09-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 7 Open Access OpenAccess
Notes ; The authors would like to thank financial support from the FWO-Flanders (project no G.0068.13). The authors further acknowledge financial support of the University of Antwerp through BOF GOA funding. S.B. acknowledges financial support from European Research Council (ERC Starting Grant #335078-COLOURATOM). ; ecas_Sara Approved Most recent IF: 3.615
Call Number UA @ lucian @ c:irua:135274 Serial 4228
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Author Godet, M.; Vergès-Belmin, V.; Gauquelin, N.; Saheb, M.; Monnier, J.; Leroy, E.; Bourgon, J.; Verbeeck, J.; Andraud, C.
Title Nanoscale investigation by TEM and STEM-EELS of the laser induced yellowing Type A1 Journal article
Year 2018 Publication Micron Abbreviated Journal Micron
Volume 115 Issue Pages 25-31
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Nd-YAG QS laser cleaning of soiled stone at 1064 nm can sometimes result in a more yellow appearance compared to other cleaning techniques. Especially in France, this yellowing effect is still considered as a major aesthetic issue by the architects and conservators. One explanation states that the yellowing is linked to the formation of iron-rich nanophase(s) through the laser beam interaction with black crusts that would re-deposit on the cleaned substrate after irradiation. To characterize these nanophases, a model crust containing hematite was elaborated and laser irradiated using a Nd-YAG QS laser. The color of the sample shifted instantaneously from red to a bright yellow and numerous particles were ablated in a visible smoke. Transmission electron microscopy (TEM) was used to examine the morphology and the crystallinity of the neo-formed compounds, both on the surface of the samples and in the ablated materials. In addition, an investigation of the chemical and structural properties of the nanophases was conducted by X-ray dispersive energy (EDX) and electron energy loss (EELS) spectroscopies. It was found that both the surface of the sample and the ablated materials are covered by crystallized nano-spheres and nano-residues, all containing iron and oxygen, sometimes along with calcium and sulfur. In particular an interfacial area containing the four elements was evidenced between some nanostructures and the substrate. Magnetite Fe3O4 was also identified at the nanoscale. This study demonstrates that the laser yellowing of a model crust is linked to the presence of iron-rich nanophases including CaxFeySzOδ nanostructures and magnetite Fe3O4 at the surface after irradiation.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000449125600004 Publication Date 2018-08-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0968-4328 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.98 Times cited 9 Open Access Not_Open_Access: Available from 19.08.2020
Notes The authors wish to thank Valérie Lalanne for the sample preparation for TEM and Stijn Van den Broeck for the FIB cut elaboration. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative–I3). Approved Most recent IF: 1.98
Call Number EMAT @ emat @c:irua:154356UA @ admin @ c:irua:154356 Serial 5056
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Author Jain, N.; Hao, Y.; Parekh, U.; Kaltenegger, M.; Pedrazo-Tardajos, A.; Lazzaroni, R.; Resel, R.; Geerts, Y.H.; Bals, S.; Van Aert, S.
Title Exploring the effects of graphene and temperature in reducing electron beam damage: A TEM and electron diffraction-based quantitative study on Lead Phthalocyanine (PbPc) crystals Type A1 Journal article
Year 2023 Publication Micron Abbreviated Journal
Volume 169 Issue Pages 103444
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract High-resolution transmission electron microscopy (TEM) of organic crystals, such as Lead Phthalocyanine (PbPc), is very challenging since these materials are prone to electron beam damage leading to the breakdown of the crystal structure during investigation. Quantification of the damage is imperative to enable high-resolution imaging of PbPc crystals with minimum structural changes. In this work, we performed a detailed electron diffraction study to quantitatively measure degradation of PbPc crystals upon electron beam irradiation. Our study is based on the quantification of the fading intensity of the spots in the electron diffraction patterns. At various incident dose rates (e/Å2/s) and acceleration voltages, we experimentally extracted the decay rate (1/s), which directly correlates with the rate of beam damage. In this manner, a value for the critical dose (e/Å2) could be determined, which can be used as a measure to quantify beam damage. Using the same methodology, we explored the influence of cryogenic temperatures, graphene TEM substrates, and graphene encapsulation in prolonging the lifetime of the PbPc crystal structure during TEM investigation. The knowledge obtained by diffraction experiments is then translated to real space high-resolution TEM imaging of PbPc.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000965998800001 Publication Date 2023-03-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0968-4328 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.4 Times cited 1 Open Access OpenAccess
Notes This work is supported by FWO and FNRS within the 2Dto3D network of the EOS (Excellence of Science) program (grant number 30489208) and ERC-CoGREALNANO-815128 (to Prof. Dr. Sara Bals). N.J. would like to thank Dr. Kunal S. Mali and Dr. Da Wang for useful and interesting discussions on sample preparation procedures. Approved Most recent IF: 2.4; 2023 IF: 1.98
Call Number EMAT @ emat @c:irua:196069 Serial 7379
Permanent link to this record
 

 
Author Bal, K.M.; Cautereels, J.; Blockhuys, F.
Title Structures and spectroscopic properties of sulfur-nitrogen-pnictogen chains : R2P-N=S=N-PR2 and R2P-N=S=N-AsR2 Type A1 Journal article
Year 2017 Publication Journal of molecular structure Abbreviated Journal J Mol Struct
Volume 1132 Issue Pages 102-108
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The conformational and configurational preferences of Me2PNSNPMe2 (3) and Me2PNSNAsMe2 (4) have been identified using quantum chemical calculations at the DFT/B3LYP/6-311+G* level of theory. An approach in which energetic, structural (geometries and bond orders), electronic (analysis of the electron density) and spectroscopic properties are combined leads to the conclusion that these sulfur-nitrogen-pnictogen chains share many of the properties of their chalcogen-nitrogen analogues but that the through-space intramolecular interactions favouring the Z,Z configuration are even weaker than in these latter compounds. The results of this analysis also lead to an unambiguous assignment of the variable-temperature 31P and 15N NMR spectra of these compounds and their structures both in solution and in the solid state.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000393254400015 Publication Date 2016-08-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2860 ISBN Additional Links UA library record; WoS full record
Impact Factor 1.753 Times cited Open Access Not_Open_Access: Available from 03.10.2019
Notes Approved Most recent IF: 1.753
Call Number UA @ lucian @ c:irua:145533 Serial 4726
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Author Ben Abdallah, M.A.; Bacchi, A.; Parisini, A.; Canossa, S.; Bergamonti, L.; Balestri, D.; Kamoun, S.
Title Crystal structure, vibrational, electrical, optical and DFT study of C₂H₁0N₂(IO₃)₂.HIO₃ Type A1 Journal article
Year 2020 Publication Journal Of Molecular Structure Abbreviated Journal J Mol Struct
Volume 1215 Issue Pages 128254-12
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The reinvestigation of the EDA-HIO3-H2O system using a different stoichiometric ratio gives rise to a new iodate salt C2H10N2(IO3)(2 center dot)HIO3 denoted as EBIMIA. In this study, we reported the structural properties of ethylenediammonium bis iodate mono iodic acid using X-ray powder and single crystal diffraction at room temperature. The Hirshfeld and the potential energy surface analysis reveal that I center dot center dot center dot O and N-H center dot center dot center dot O are the most noticeable interactions that took place inside the crystal and contribute to the cohesion and stability of the synthesized compound. The DSC measurement shows that this iodate salt undergoes two structural phase transitions, the first occurs at T = 290 K while the second occurs at T = 363 K. However, the dielectric analysis confirms only the second transition because it lies in the studied temperature domain 338-413K. Besides, the impedance data obey a circuit model consisting of a parallel combination of a bulk resistance and CPE. The frequency dispersion of the conductivity follows Jonscher's law and the charge carrier transport may be interpreted using the correlation barrier hopping mechanism (CBH). Finally, the electronic properties and the vibrational analysis of this novel iodate salt are studied using DFT and compared to the experimental data given by the FT-IR, Raman and UV-visible spectroscopies. (C) 2020 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000537221300012 Publication Date 2020-04-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2860 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.8 Times cited Open Access OpenAccess
Notes ; The authors are grateful to Pr. Giovani Predieri, Pr. Pier Paolo Lottici, and Pr. Danilo Bersani, for their help with the vibrational measurement. Moreover, authors wish to thank, Pr. Salvatore Vantaggio and Dr. Silvio Scaravonati for their contribution in carrying out the impedance spectroscopy measurements. The authors acknowledge also the Analytical Chemistry, Cultural Heritage, Inorganic Chemistry and Crystallography Unit (SCVSA department, university of Parma, Italy) and the Tunisian Ministry of Higher Education and Scientific Research (LR11ES46) for their support. ; Approved Most recent IF: 3.8; 2020 IF: 1.753
Call Number UA @ admin @ c:irua:170148 Serial 6480
Permanent link to this record
 

 
Author Yang, M.; Chen, H.; Orekhov, A.; Lu, Q.; Lan, X.; Li, K.; Zhang, S.; Song, M.; Kong, Y.; Schryvers, D.; Du, Y.
Title Quantified contribution of β″ and β′ precipitates to the strengthening of an aged Al–Mg–Si alloy Type A1 Journal article
Year 2020 Publication Materials Science And Engineering A-Structural Materials Properties Microstructure And Processing Abbreviated Journal Mat Sci Eng A-Struct
Volume 774 Issue Pages 138776
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract It is generally believed that β00 precipitates, rather than β0 precipitates, are the major strengthening precipitates in

aged Al–Mg–Si alloys. The reason for this difference is not well understood. To clarify this, two samples of the

same Al–Mg–Si alloy but with different aging states were prepared. The under-aged sample only contains nanoprecipitates

of the β00 type, while the peak-aged one contains nearly equal volumes of β00 and β0 precipitates. We

have, for the first time, separated the strengthening effect of the contribution from βʺ and βʹ precipitates,

respectively, by an indirect approach based on high-precision measurements of volume fractions, number densities,

sizes, proportions of the precipitates, their lattice strains, the composition and grain size of the matrix. The

β0 precipitates, which take 45.6% of the total precipitate volume in the peak-aged sample, contribute to the entire

precipitation strengthening by only 31.6%. The main reason why they are less useful compared to β00 precipitates

has been found to be associated with their smaller lattice strains relative to the matrix, which is 0.99% versus

2.10% (for β00 ).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000514747200001 Publication Date 2019-12-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-5093 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.4 Times cited Open Access OpenAccess
Notes National Natural Science Foundation of China, 51531009 51711530713 51501230 ; Central South University, 2018gczd033 ; Flemish Science Foundation, VS.026.18N ; Program for Guangdong Introducing Innovative and Entrepreneurial Teams, 2016ZT06G025 ; Guangdong Natural Science Foundation, 2017B030306014 ; Approved Most recent IF: 6.4; 2020 IF: 3.094
Call Number EMAT @ emat @c:irua:165290 Serial 5440
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Author Gkanatsiou, A.; Lioutas, C.B.; Frangis, N.; Polychroniadis, E.K.; Prystawko, P.; Leszczynski, M.; Altantzis, T.; Van Tendeloo, G.
Title Influence of 4H-SiC substrate miscut on the epitaxy and microstructure of AlGaN/GaN heterostructures Type A1 Journal article
Year 2019 Publication Materials science in semiconductor processing Abbreviated Journal Mat Sci Semicon Proc
Volume 91 Issue Pages 159-166
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract AlGaN/GaN heterostructures were grown on “on-axis” and 2° off (0001) 4H-SiC substrates by metalorganic vapor phase epitaxy (MOVPE). Structural characterization was performed by transmission electron microscopy. The dislocation density, being greater in the on-axis case, is gradually reduced in the GaN layer and is forming

dislocation loops in the lower region. Steps aligned along [11̅00] in the off-axis case give rise to simultaneous defect formation. In the on-axis case, an almost zero density of steps is observed, with the main origin of defects probably being the orientation mismatch at the grain boundaries between the small not fully coalesced AlN grains. V-shaped formations are observed in the AlN nucleation layer, but are more frequent in the off-axis case, probably enhanced by the presence of steps. These V-shaped formations are completely overgrown by the GaN layer, during the subsequent deposition, presenting AlGaN areas in the walls of the defect, indicating an interdiffusion between the layers. Finally, at the AlGaN/GaN heterostructure surface in the on-axis case, V-shapes are observed, with the AlN spacer and AlGaN (21% Al) thickness on relaxed GaN exceeding the critical thickness for relaxation. On the other hand, no relaxation in the form of V-shape creation is observed in the off-axis case, probably due to the smaller AlGaN thickness (less than 21% Al). The AlN spacer layer, grown in between the heterostructure, presents a uniform thickness and clear interfaces.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000454537700022 Publication Date 2018-11-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1369-8001 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.359 Times cited 1 Open Access Not_Open_Access
Notes Funding: This work was supported by the IKY Fellowships of Excellence for Postgraduate Studies in Greece-SIEMENS Program; the Greek General Secretariat for Research and Technology, contract SAE 013/8–2009SE 01380012; and the JU ENIAC Project LAST POWER Large Area silicon carbide Substrates and heteroepitaxial GaN for POWER device applications [grant number 120218]. Also part of the research leading to these results has received funding from the European Union Seventh Framework Program under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative–I3). T.A. acknowledges financial support from the Research Foundation Flanders (FWO, Belgium) through a post-doctoral grant. Approved Most recent IF: 2.359
Call Number EMAT @ emat @UA @ admin @ c:irua:156200 Serial 5149
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Author Juneja, R.; Thebaud, S.; Pandey, T.; Polanco, C.A.; Moseley, D.H.; Manley, M.E.; Cheng, Y.Q.; Winn, B.; Abernathy, D.L.; Hermann, R.P.; Lindsay, L.
Title Quasiparticle twist dynamics in non-symmorphic materials Type A1 Journal article
Year 2021 Publication Materials Today Physics Abbreviated Journal
Volume 21 Issue Pages 100548
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Quasiparticle physics underlies our understanding of the microscopic dynamical behaviors of materials that govern a vast array of properties, including structural stability, excited states and interactions, dynamical structure factors, and electron and phonon conductivities. Thus, understanding band structures and quasiparticle interactions is foundational to the study of condensed matter. Here we advance a 'twist' dynamical description of quasiparticles (including phonons and Bloch electrons) in nonsymmorphic chiral and achiral materials. Such materials often have structural complexity, strong thermal resistance, and efficient thermoelectric performance for waste heat capture and clean refrigeration technologies. The twist dynamics presented here provides a novel perspective of quasiparticle behaviors in such complex materials, in particular highlighting how non-symmorphic symmetries determine band crossings and anti-crossings, topological behaviors, quasiparticle interactions that govern transport, and observables in scattering experiments. We provide specific context via neutron scattering measurements and first-principles calculations of phonons and electrons in chiral tellurium dioxide. Building twist symmetries into the quasiparticle dynamics of non-symmorphic materials offers intuition into quasi particle behaviors, materials properties, and guides improved experimental designs to probe them. More specifically, insights into the phonon and electron quasiparticle physics presented here will enable materials design strategies to control interactions and transport for enhanced thermoelectric and thermal management applications. (C) 2021 Published by Elsevier Ltd.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000708226400009 Publication Date 2021-09-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2542-5293 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:184040 Serial 7016
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Author Sun, C.; Street, M.; Zhang, C.; Van Tendeloo, G.; Zhao, W.; Zhang, Q.
Title Boron structure evolution in magnetic Cr₂O₃ thin films Type A1 Journal article
Year 2022 Publication Materials Today Physics Abbreviated Journal
Volume 27 Issue Pages 100753-100757
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract B substituting O in antiferromagnetic Cr2O3 is known to increase the Ne ' el temperature, whereas the actual B dopant site and the corresponding functionality remains unclear due to the complicated local structure. Herein, A combination of electron energy loss spectroscopy and first-principles calculations were used to unveil B local structures in B doped Cr2O3 thin films. B was found to form either magnetic active BCr4 tetrahedra or various inactive BO3 triangles in the Cr2O3 lattice, with a* and z* bonds exhibiting unique spectral features. Identification of BO3 triangles was achieved by changing the electron momentum transfer to manipulate the differential cross section for the 1s-z* and 1s-a* transitions. Modeling the experimental spectra as a linear combination of simulated B K edges reproduces the experimental z* / a* ratios for 15-42% of the B occupying the active BCr4 structure. This result is further supported by first-principles based thermodynamic calculations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000827323200003 Publication Date 2022-06-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2542-5293 ISBN Additional Links UA library record; WoS full record
Impact Factor 11.5 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 11.5
Call Number UA @ admin @ c:irua:189660 Serial 7078
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Author Abakumov, M.A.; Nukolova, N.V.; Sokolsky-Papkov, M.; Shein, S.A.; Sandalova, T.O.; Vishwasrao, H.M.; Grinenko, N.F.; Gubsky, I.L.; Abakumov, A.M.; Kabanov, A.V.; Chekhonin, V.P.;
Title VEGF-targeted magnetic nanoparticles for MRI visualization of brain tumor Type A1 Journal article
Year 2015 Publication Nanomedicine: nanotechnology, biology and medicine Abbreviated Journal Nanomed-Nanotechnol
Volume 11 Issue 11 Pages 825-833
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract This work is focused on synthesis and characterization of targeted magnetic nanoparticles as magnetic resonance imaging (MRI) agents for in vivo visualization of gliomas. Ferric oxide (Fe3O4) cores were synthesized by thermal decomposition and coated with bovine serum albumin (BSA) to form nanoparticles with D-eff of 53 +/- 9 nm. The BSA was further cross-linked to improve colloidal stability. Monoclonal antibodies against vascular endothelial growth factor (mAbVEGF) were covalently conjugated to BSA through a polyethyleneglycol linker. Here we demonstrate that 1) BSA coated nanoparticles are stable and non-toxic to different cells at concentration up to 2.5 mg/mL; 2) conjugation of monoclonal antibodies to nanoparticles promotes their binding to VEGF-positive glioma C6 cells in vitro; 3) targeted nanoparticles are effective in MRI visualization of the intracranial glioma. Thus, mAbVEGF-targeted BSA-coated magnetic nanoparticles are promising MRI contrast agents for glioma visualization. (C) 2015 Elsevier Inc. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication S.l. Editor
Language Wos 000354559600004 Publication Date 2015-01-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1549-9634; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.72 Times cited 62 Open Access
Notes Approved Most recent IF: 5.72; 2015 IF: 6.155
Call Number c:irua:126351 Serial 3838
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