|   | 
Details
   web
Records
Author Roesler, C.; Aijaz, A.; Turner, S.; Filippousi, M.; Shahabi, A.; Xia, W.; Van Tendeloo, G.; Muhler, M.; Fischer, R.A.
Title Hollow Zn/Co Zeolitic Imidazolate Framework (ZIF) and Yolk-Shell Metal@Zn/Co ZIF nanostructures Type A1 Journal article
Year 2016 Publication Chemistry: a European journal Abbreviated Journal Chem-Eur J
Volume 22 Issue 22 Pages 3304-3311
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Metal-organic frameworks (MOFs) feature a great possibility for a broad spectrum of applications. Hollow MOF structures with tunable porosity and multifunctionality at the nanoscale with beneficial properties are desired as hosts for catalytically active species. Herein, we demonstrate the formation of well-defined hollow Zn/Co-based zeolitic imidazolate frameworks (ZIFs) by use of epitaxial growth of Zn-MOF (ZIF-8) on preformed Co-MOF (ZIF-67) nanocrystals that involve in situ self-sacrifice/excavation of the Co-MOF. Moreover, any type of metal nanoparticles can be accommodated in Zn/Co-ZIF shells to generate yolk-shell metal@ZIF structures. Transmission electron microscopy and tomography studies revealed the inclusion of these nanoparticles within hollow Zn/Co-ZIF with dominance of the Zn-MOF as shell. Our findings lead to a generalization of such hollow systems that are working effectively to other types of ZIFs.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000371419200001 Publication Date 2016-01-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0947-6539 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.317 Times cited 43 Open Access
Notes Approved Most recent IF: 5.317
Call Number UA @ lucian @ c:irua:132347 Serial 4192
Permanent link to this record
 

 
Author Bertoni, G.; Fabbri, F.; Villani, M.; Lazzarini, L.; Turner, S.; Van Tendeloo, G.; Calestani, D.; Gradečak, S.; Zappettini, A.; Salviati, G.
Title Nanoscale mapping of plasmon and exciton in ZnO tetrapods coupled with Au nanoparticles Type A1 Journal article
Year 2016 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
Volume 6 Issue 6 Pages 19168
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (up) Metallic nanoparticles can be used to enhance optical absorption or emission in semiconductors, thanks to a strong interaction of collective excitations of free charges (plasmons) with electromagnetic fields. Herein we present the direct imaging at the nanoscale of plasmon-exciton coupling in Au/ZnO nanostructures by combining scanning transmission electron energy loss and cathodoluminescence spectroscopy and mapping. The Au nanoparticles (~30 nm in diameter) are grown in-situ on ZnO nanotetrapods by means of a photochemical process without the need of binding agents or capping molecules. This results in clean interfaces, enabling to prove the occurrence of the plasmon-exciton coupling and the straightforward mapping of its spatial localization. Interestingly, the Au plasmon resonance is localized at the Au/vacuum interface, rather than presenting an isotropic distribution around the nanoparticle. On the contrary, a strong localization of the ZnO excitons, has been observed inside the Au nanoparticle, revealing the existence of the plasmon-exciton coupling, as also confirmed by numerical simulations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000368111900001 Publication Date 2016-01-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.259 Times cited 15 Open Access
Notes The research leading to these results has received funding from the European Union FP7 Grant Agreement n. 265073 ITN-Nanowiring, and FP7 Grant Agreement n. 312483 ESTEEM2 for Integrated Infrastructure Initiative – I3. S.T. gratefully acknowledges the FWO Vlaanderen. G.V.T. acknowledges the European Research Council (ERC grant N°246791 – COUNTATOMS). The authors thank Alessandra Catellani and Arrigo Calzolari for helpful discussions.; Esteem2_jra3 Approved Most recent IF: 4.259
Call Number c:irua:130406 c:irua:130406 Serial 3999
Permanent link to this record
 

 
Author Calizzi, M.; Venturi, F.; Ponthieu, M.; Cuevas, F.; Morandi, V.; Perkisas, T.; Bals, S.; Pasquini, L.
Title Gas-phase synthesis of Mg-Ti nanoparticles for solid-state hydrogen storage Type A1 Journal article
Year 2016 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 18 Issue 18 Pages 141-148
Keywords A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT)
Abstract (up) Mg-Ti nanostructured samples with different Ti contents were prepared via compaction of nanoparticles grown by inert gas condensation with independent Mg and Ti vapour sources. The growth set-up offered the option to perform in situ hydrogen absorption before compaction. Structural and morphological characterisation was carried out by X-ray diffraction, energy dispersive spectroscopy and electron microscopy. The formation of an extended metastable solid solution of Ti in hcp Mg was detected up to 15 at% Ti in the as-grown nanoparticles, while after in situ hydrogen absorption, phase separation between MgH2 and TiH2 was observed. At a Ti content of 22 at%, a metastable Mg-Ti-H fcc phase was observed after in situ hydrogen absorption. The co-evaporation of Mg and Ti inhibited nanoparticle coalescence and crystallite growth in comparison with the evaporation of Mg only. In situ hydrogen absorption was beneficial to subsequent hydrogen behaviour, studied by high pressure differential scanning calorimetry and isothermal kinetics. A transformed fraction of 90% was reached within 100 s at 300 degrees C during both hydrogen absorption and desorption. The enthalpy of hydride formation was not observed to differ from bulk MgH2.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000368755500014 Publication Date 2015-11-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 31 Open Access Not_Open_Access
Notes ; Part of this work was supported by the COST Action MP1103 “Nanostructured materials for solid-state hydrogen storage”. ; Approved Most recent IF: 4.123
Call Number UA @ lucian @ c:irua:131589 Serial 4184
Permanent link to this record
 

 
Author Meledina, M.; Turner, S.; Filippousi, M.; Leus, K.; Lobato, I.; Ramachandran, R.K.; Dendooven, J.; Detavernier, C.; Van Der Voort, P.; Van Tendeloo, G.
Title Direct Imaging of ALD Deposited Pt Nanoclusters inside the Giant Pores of MIL-101 Type A1 Journal article
Year 2016 Publication Particle and particle systems characterization Abbreviated Journal Part Part Syst Char
Volume 33 Issue 33 Pages 382-387
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (up) MIL-101 giant-pore metal-organic framework (MOF) materials have been loaded with Pt nanoparticles using atomic layer deposition. The final structure has been investigated by aberration-corrected annular dark-field scanning transmission electron microscopy under strictly controlled low dose conditions. By combining the acquired experimental data with image simulations, the position of the small clusters within the individual pores of a metal-organic framework has been determined. The embedding of the Pt nanoparticles is confirmed by electron tomography, which shows a distinct ordering of the highly uniform Pt nanoparticles. The results show that atomic layer deposition is particularly well-suited for the deposition of individual nanoparticles inside MOF framework pores and that, upon proper regulation of the incident electron dose, annular dark-field scanning transmission electron microscopy is a powerful tool for the characterization of this type of materials at a local scale.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000379970000006 Publication Date 2016-02-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0934-0866 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.474 Times cited 11 Open Access
Notes S.T. and J.D. gratefully acknowledge the FWO Vlaanderen for a postdoctoral scholarship. The Titan microscope used for this investigation was partially funded by the Hercules foundation of the Flemish government. This work was supported by the Belgian IAP-PAI network. K.L. acknowledges the financial support from the Ghent University BOF postdoctoral Grant 01P06813T and UGent GOA Grant 01G00710. C.D. thanks the FWO Vlaanderen, BOF-UGent (GOA 01G01513), and the Hercules Foundation (AUGE/09/014) for financial support. Approved Most recent IF: 4.474
Call Number c:irua:131913 Serial 4028
Permanent link to this record
 

 
Author Roy, P.; Torun, E.; de Groot, R.A.
Title Effect of doping and elastic properties in (Mn,Fe)2(Si,P) Type A1 Journal article
Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 93 Issue 93 Pages 094110
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Mixed magnetism (the coexistence of strong and weak magnetism in one material) is regarded as the origin of the giant magnetocaloric effect (GMCE). A good example is (Mn,Fe)(2)(Si,P), which is established as one of the best magnetocaloric materials available. Tuning the material properties are essential for optimizing its performance, and a straightforward way to do that is by doping. In this article, an ab initio electronic structure method was used to calculate the structure and magnetic properties of 3d-transition-metal-doped (Mn,Fe)(2)(Si,P) materials for magnetocaloric applications (transition metals are Cr, Co, Mn, Ni, Cu). For a steady performance, the material should be mechanically stable. A detailed analysis of the elastic constants shows that the mechanical stability of the (Mn,Fe)(2)(Si,P) system increases significantly by doping with boron without affecting the magnetic properties. Insights of the influence of doping enable future studies to understand and predict bettermagnetocaloric materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000372712100001 Publication Date 2016-03-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950;2469-9969; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 9 Open Access
Notes ; This work is part of an Industrial Partnership Programme (IPP I28) of Fundamenteel Onderzoek der Materie (FOM) (The Netherlands) and co-financed by BASF New Business. The authors would like to thank Phuong Thao Nguyen and Dr. Gilles A. de Wijs for very useful discussions. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:133192 Serial 4164
Permanent link to this record
 

 
Author Bogaerts, A.; Khosravian, N.; Van der Paal, J.; Verlackt, C.C.W.; Yusupov, M.; Kamaraj, B.; Neyts, E.C.
Title Multi-level molecular modelling for plasma medicine Type A1 Journal article
Year 2016 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 49 Issue 49 Pages 054002
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) Modelling at the molecular or atomic scale can be very useful for obtaining a better insight in plasma medicine. This paper gives an overview of different atomic/molecular scale modelling approaches that can be used to study the direct interaction of plasma species with biomolecules or the consequences of these interactions for the biomolecules on a somewhat longer time-scale. These approaches include density functional theory (DFT), density functional based tight binding (DFTB), classical reactive and non-reactive molecular dynamics (MD) and united-atom or coarse-grained MD, as well as hybrid quantum mechanics/molecular mechanics (QM/MM) methods. Specific examples will be given for three important types of biomolecules, present in human cells, i.e. proteins, DNA and phospholipids found in the cell membrane. The results show that each of these modelling approaches has its specific strengths and limitations, and is particularly useful for certain applications. A multi-level approach is therefore most suitable for obtaining a global picture of the plasma–biomolecule interactions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000368944100003 Publication Date 2015-12-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 11 Open Access
Notes This work is financially supported by the Fund for Scientific Research Flanders (FWO) and the Francqui Foundation. The calculations were carried out in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen. Approved Most recent IF: 2.588
Call Number c:irua:131571 Serial 3985
Permanent link to this record
 

 
Author Rezaei, M.; Seuntjens, P.; Joris, I.; Boenne, W.; Van Hoey, S.; Campling, P.; Cornelis, W.M.
Title Sensitivity of water stress in a two-layered sandy grassland soil to variations in groundwater depth and soil hydraulic parameters Type A1 Journal article
Year 2016 Publication Hydrology and earth system sciences Abbreviated Journal
Volume 20 Issue 1 Pages 487-503
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (up) Monitoring and modelling tools may improve irrigation strategies in precision agriculture. We used non-invasive soil moisture monitoring, a crop growth and a soil hydrological model to predict soil water content fluctuations and crop yield in a heterogeneous sandy grassland soil under supplementary irrigation. The sensitivity of the soil hydrological model to hydraulic parameters, water stress, crop yield and lower boundary conditions was assessed after integrating models. Free drainage and incremental constant head conditions were implemented in a lower boundary sensitivity analysis. A time-dependent sensitivity analysis of the hydraulic parameters showed that changes in soil water content are mainly affected by the soil saturated hydraulic conductivity K-s and the Mualem-van Genuchten retention curve shape parameters n and alpha. Results further showed that different parameter optimization strategies (two-, three-, four- or six-parameter optimizations) did not affect the calculated water stress and water content as significantly as does the bottom boundary. In this case, a two-parameter scenario, where K-s was optimized for each layer under the condition of a constant groundwater depth at 135-140 cm, performed best. A larger yield reduction, and a larger number and longer duration of stress conditions occurred in the free drainage condition as compared to constant boundary conditions. Numerical results showed that optimal irrigation scheduling using the aforementioned water stress calculations can save up to 12-22 % irrigation water as compared to the current irrigation regime. This resulted in a yield increase of 4.5-6.5 %, simulated by the crop growth model.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000369668400028 Publication Date 2016-01-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1027-5606; 1607-7938 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:132259 Serial 8514
Permanent link to this record
 

 
Author Yagmurcukardes, M.; Horzum, S.; Torun, E.; Peeters, F.M.; Senger, R.T.
Title Nitrogenated, phosphorated and arsenicated monolayer holey graphenes Type A1 Journal article
Year 2016 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 18 Issue 18 Pages 3144-3150
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Motivated by a recent experiment that reported the synthesis of a new 2D material nitrogenated holey graphene (C2N) [Mahmood et al., Nat. Commun., 2015, 6, 6486], the electronic, magnetic, and mechanical properties of nitrogenated (C2N), phosphorated (C2P) and arsenicated (C2As) monolayer holey graphene structures are investigated using first-principles calculations. Our total energy calculations indicate that, similar to the C2N monolayer, the formation of the other two holey structures are also energetically feasible. Calculated cohesive energies for each monolayer show a decreasing trend going from the C2N to C2As structure. Remarkably, all the holey monolayers considered are direct band gap semiconductors. Regarding the mechanical properties (in-plane stiffness and Poisson ratio), we find that C2N has the highest in-plane stiffness and the largest Poisson ratio among the three monolayers. In addition, our calculations reveal that for the C2N, C2P and C2As monolayers, creation of N and P defects changes the semiconducting behavior to a metallic ground state while the inclusion of double H impurities in all holey structures results in magnetic ground states. As an alternative to the experimentally synthesized C2N, C2P and C2As are mechanically stable and flexible semiconductors which are important for potential applications in optoelectronics.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000369506000095 Publication Date 2015-12-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 36 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). ; Approved Most recent IF: 4.123
Call Number UA @ lucian @ c:irua:132313 Serial 4214
Permanent link to this record
 

 
Author Reguera, J.; Jiménez de Aberasturi, D.; Naomi Winckelmans, N.; Langer, J.; Bals, S.; Liz-Marzan, L.M.
Title Synthesis of Janus plasmonic-magnetic, star-sphere nanoparticles, and their application in SERS detection Type A1 Journal article
Year 2016 Publication Faraday discussions Abbreviated Journal Faraday Discuss
Volume 191 Issue 191 Pages 47-59
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Multicomponent nanoparticles are of particular interest due to a unique combination of properties at the nanoscale, which make them suitable for a wide variety of applications. Among them, Janus nanoparticles, presenting two distinct surface regions, can lead to specific interactions with interfaces, biomolecules, membranes etc. We report the synthesis of Janus nanoparticles comprising iron oxide nanospheres and gold nanostars, through two consecutive seed-mediated-growth steps. Electron tomography combining HAADF-STEM and EDX mapping has been performed to evaluate the spatial distribution of the two components of the nanoparticle, showing their clear separation in a Janus morphology. Additionally, SERS measurements assisted by magnetic separation were carried out to assess the application of combined plasmonic and magnetic properties for sensing.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000385257300003 Publication Date 2016-03-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6640 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.588 Times cited 53 Open Access OpenAccess
Notes This work has been funded by the European Research Council (ERC Advanced Grant #267867, Plasmaquo). N.W. and S.B. acknowledge funding by the European Research Council (ERC Starting Grant #335078, Colouratom).; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); Approved Most recent IF: 3.588
Call Number c:irua:132891 Serial 4060
Permanent link to this record
 

 
Author Kirilenko, D.A.; Brunkov, P.N.
Title Measuring the height-to-height correlation function of corrugation in suspended graphene Type A1 Journal article
Year 2016 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 165 Issue 165 Pages 1-7
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract (up) Nanocorrugation of 2D crystals is an important phenomenon since it affects their electronic and mechanical properties. The corrugation may have various sources; one of them is flexural phonons that, in particular, are responsible for the thermal conductivity of graphene. A study of corrugation of just the suspended graphene can reveal much of valuable information on the physics of this complicated phenomenon. At the same time, the suspended crystal nanorelief can hardly be measured directly because of high flexibility of the 2D crystal. Moreover, the relief portion related to rapid out-of-plane oscillations (flexural phonons) is also inaccessible by such measurements. Here we present a technique for measuring the Fourier components of the height-height correlation function H(q) of suspended graphene which includes the effect of flexural phonons. The technique is based on the analysis of electron diffraction patterns. The H(q) is measured in the range of wavevectors q approximately 0.4-4.5nm(-1). At the upper limit of this range H(q) does follow the T/kappaq(4) law. So, we measured the value of suspended graphene bending rigidity kappa=1.2+/-0.4eV at ambient temperature T approximately 300K. At intermediate wave vectors, H(q) follows a slightly weaker exponent than theoretically predicted q(-3.15) but is closer to the results of the molecular dynamics simulation. At low wave vectors, the dependence becomes even weaker, which may be a sign of influence of charge carriers on the dynamics of undulations longer than 10nm. The technique presented can be used for studying physics of flexural phonons in other 2D materials.
Address Ioffe Institute, Politekhnicheskaya ul. 26, 194021 St-Petersburg, Russia; ITMO University, Kronverksky pr. 49, 197101 St. Petersburg, Russia
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000375946200001 Publication Date 2016-03-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links
Impact Factor 2.843 Times cited 3 Open Access
Notes D.K. thanks the RFBR (Grant no. 16-32-60165) for the partial support of this research. The work was carried out in part at the Joint Research Center “Material Science and Characterization in Advanced Technologies” (St-Petersburg, Russia) under the financial support from the Ministry of Education and Science of the Russian Federation (Agreement 14.621.21.0007, 04.12.2014, id RFMEFI62114X0007, the use of the Jeol JEM-2100F microscope) and at EMAT, Universiteit Antwerpen (Antwerpen, Belgium), (the use of the FEI Tecnai G2 microscope). Approved Most recent IF: 2.843
Call Number EMAT @ emat @ Serial 4124
Permanent link to this record
 

 
Author Ilin, A.; Martyshov, M.; Forsh, E.; Forsh, P.; Rumyantseva, M.; Abakumov, A.; Gaskov, A.; Kashkarov, P.
Title UV effect on NO2 sensing properties of nanocrystalline In2O3 Type A1 Journal article
Year 2016 Publication Sensors and actuators : B : chemical Abbreviated Journal Sensor Actuat B-Chem
Volume 231 Issue 231 Pages 491-496
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Nanocrystalline indium oxide films with extremely small grains in range of 7-40 nm are prepared by sol-gel method. The influence of grain size on the sensitivity of indium oxide to nitrogen dioxide in low concentration at room temperature is investigated under the UV illumination and without illumination. The sensitivity increases with the decrease of grain sizes when In2O3 is illuminated while in the dark In2O3 with intermediate grain size exhibits the highest response. An explanation of the different behavior of the In2O3 with different grain size sensitivity to NO2 under illumination and in the dark is proposed. We demonstrate that pulsed illumination may be used for NO2 detection at room temperature that significantly reduces the power consumption of sensor. (C) 2016 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos 000374330900055 Publication Date 2016-03-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-4005 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.401 Times cited 27 Open Access
Notes Approved Most recent IF: 5.401
Call Number UA @ lucian @ c:irua:133630 Serial 4273
Permanent link to this record
 

 
Author Zanaga, D.; Bleichrodt, F.; Altantzis, T.; Winckelmans, N.; Palenstijn, W.J.; Sijbers, J.; de Nijs, B.; van Huis, M.A.; Sanchez-Iglesias, A.; Liz-Marzan, L.M.; van Blaaderen, A.; Joost Batenburg, K.; Bals, S.; Van Tendeloo, G.
Title Quantitative 3D analysis of huge nanoparticle assemblies Type A1 Journal article
Year 2016 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 8 Issue 8 Pages 292-299
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Vision lab
Abstract (up) Nanoparticle assemblies can be investigated in 3 dimensions using electron tomography. However, it is not straightforward to obtain quantitative information such as the number of particles or their relative position. This becomes particularly difficult when the number of particles increases. We propose a novel approach in which prior information on the shape of the individual particles is exploited. It improves the quality of the reconstruction of these complex assemblies significantly. Moreover, this quantitative Sparse Sphere Reconstruction approach yields directly the number of particles and their position as an output of the reconstruction technique, enabling a detailed 3D analysis of assemblies with as many as 10 000 particles. The approach can also be used to reconstruct objects based on a very limited number of projections, which opens up possibilities to investigate beam sensitive assemblies where previous reconstructions with the available electron tomography techniques failed.
Address EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. sara.bals@uantwerpen.be
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000366911700028 Publication Date 2015-11-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 34 Open Access OpenAccess
Notes The authors acknowledge financial support from European Research Council (ERC Starting Grant # 335078-COLOURATOMS, ERC Advanced Grant # 291667 HierarSACol and ERC Advanced Grant 267867 – PLASMAQUO), the European Union under the FP7 (Integrated Infrastructure Initiative N. 262348 European Soft Matter Infrastructure, ESMI and N. 312483 ESTEEM2), and from the Netherlands Organisation for Scientific Research (NWO), project number 639.072.005 and NWO CW 700.57.026. Networking support was provided by COST Action MP1207.; esteem2jra4; ECASSara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); Approved Most recent IF: 7.367
Call Number c:irua:131062 c:irua:131062 Serial 3979
Permanent link to this record
 

 
Author Geboes, B.; Ustarroz, J.; Sentosun, K.; Vanrompay, H.; Hubin, A.; Bals, S.; Breugelmans, T.
Title Electrochemical behavior of electrodeposited nanoporous Pt catalysts for the oxygen reduction reaction Type A1 Journal article
Year 2016 Publication ACS catalysis Abbreviated Journal Acs Catal
Volume 6 Issue 6 Pages 5856-5864
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract (up) Nanoporous Pt based nanoparticles (NP's) are promising fuel cell catalysts due to their high surface area and increased electrocatalytic activity toward the ORR In this work a direct double-pulse electrodeposition procedure at room temperature is applied to obtain dendritic Pt structures (89 nm diameter) with a high level of porosity (ca. 25%) and nanopores of 2 nm protruding until the center of the NP's. The particle morphology is characterized using aberration corrected high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and electron tomography (ET) combined with field emission scanning electron microscopy (FESEM) and macroscopic electrochemical measurements to assess their activity and stability toward the ORR. Macroscopic determination of the active surface area through hydrogen UPD measurements in combination with FESEM and ET showed that a considerable amount of the active sites inside the pores of the low overpotential NP's were accessible to oxygen species. As a result of this accessibility, up to a 9-fold enhancement of the Pt mass corrected ORR activity at 0.85 V vs RHE was observed at the highly porous structures. After successive potential cycling upward to 1.5 V vs RHE in a deaerated HClO4 solution a negative shift of 71 mV in half-wave potential occurred. This decrease in ORR activity could be correlated to the partial collapse of the nanopores, visible in both the EASA values and 3D ET reconstructions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000382714000025 Publication Date 2016-07-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2155-5435 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 10.614 Times cited 48 Open Access OpenAccess
Notes ; The Quanta 250 FEG microscope of the Electron Microscopy for Material Science group at the University of Antwerp was funded by the Hercules foundation of the Flemish Government. The authors acknowledge financial support from the Fonds Wetenschappelijk Onderzoek in Flanders (FWOAL708). S.B. acknowledges financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS). J.U. acknowledges funding from the Fonds Wetenschappelijk Onderzoek in Flanders (FWO, postdoctoral grant 12I7816N). ; ecas_Sara Approved Most recent IF: 10.614
Call Number UA @ lucian @ c:irua:135703 Serial 4302
Permanent link to this record
 

 
Author Poelma, R.H.; Fan, X.; Hu, Z.-Y.; Van Tendeloo, G.; van Zeijl, H.W.; Zhang, G.Q.
Title Effects of Nanostructure and Coating on the Mechanics of Carbon Nanotube Arrays Type A1 Journal article
Year 2016 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
Volume 26 Issue 26 Pages 1233-1242
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (up) Nanoscale materials are one of the few engineering materials that can be grown from the bottom up in a controlled manner. Here, the effects of nanostructure and nanoscale conformal coating on the mechanical behavior of vertically aligned carbon nanotube (CNT) arrays through experiments and simulation are systematically investigated. A modeling approach is developed and used to quantify the compressive strength and modulus of the CNT array under large deformation. The model accounts for the porous

nanostructure, which contains multiple CNTs with random waviness, van der Waals interactions, fracture strain, contacts, and frictional forces. CNT array micropillars are grown and their porous nanostructure is controlled by the infi ltration and deposition of thin conformal coatings using chemical vapor deposition. Flat-punch nanoindentation experiments reveal signifi cant changes in material properties as a function of coating thickness. The simulations explain the experimental results and show the novel failure transition regime that changes from collective CNT buckling toward structural collapse due to fracture. The compressive strength and the elastic

modulus increase exponentially as a function of the coating thickness and demonstrate a unique dependency on the CNT waviness. More interestingly, a design rule is identifi ed that predicts the optimum coating thickness for porous materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000371078100010 Publication Date 2016-01-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301X ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 17 Open Access
Notes The research leading to the TEM/HAADF-STEM results received funding from the EC Framework 7 Program ESTEEM2 (Reference 312483). We wish to acknowledge the support of the Else Kooi Laboratory for their assistance during the clean room processing.; esteem2_ta Approved Most recent IF: 12.124
Call Number c:irua:130060 c:irua:130060 Serial 3996
Permanent link to this record
 

 
Author Wee, L.H.; Meledina, M.; Turner, S.; Custers, K.; Kerkhofs, S.; Sree, S.P.; Gobechiya, E.; Kirschhock, C.E.A.; Van Tendeloo, G.; Martens, J.A.
Title Anatase TiO2nanoparticle coating on porous COK-12 platelets as highly active and reusable photocatalysts Type A1 Journal article
Year 2016 Publication RSC advances Abbreviated Journal Rsc Adv
Volume 6 Issue 6 Pages 46678-46685
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Nanoscale TiO2 photocatalysts are widely used for biomedical applications, self-cleaning processes and wastewater treatments. The impregnation/deposition of TiO2 nanoparticles is indispensable for facile handling and separation as well as the improvement of their photocatalytic performance. In the present study, ordered mesoporous COK-12 silica thin platelets with a high-aspect-ratio and rough surfaces are demonstrated as a potential nanoporous support for homogeneous TiO2 nanoparticle coatings with high loading up to 16.7 wt%. The photocatalytic composite of COK-12 platelets and TiO2 nanoparticles is characterized in detail by HRSEM, SAXS, XRD, N2 physisorption analysis, solid-state UV-vis spectroscopy, HAADF-STEM, EDX analysis, and electron tomography. HAADF-STEM-EDX and electron tomography studies reveal a homogeneous dispersion of nanosized TiO2 nanoparticles over COK-12 platelets. The final composite material with anatase TiO2 nanoparticles that demonstrate a blueshifted semiconductor band gap energy of 3.2 eV coated on a highly porous COK-12 support shows exceptional photocatalytic catalytic activity for photodegradation of organic dyes (rhodamine 6G and methylene blue) and an organic pollutant (1-adamantanol) under UV light radiation, outperforming the commercial P25 TiO2 (Degussa) catalyst.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000377254800070 Publication Date 2016-05-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2046-2069 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.108 Times cited 6 Open Access
Notes L. H. W. and S. T. thanks the FWO-Vlaanderen for a postdoctoral research fellowships under contract number (12M1415N) and (G004613N), respectively. J. A.Mgratefully acknowledge nancial supports from Flemish Government (Long-term structural funding-Methusalem). Collaboration among universities was supported by the Belgium Government (IAP-PAI networking). Approved Most recent IF: 3.108
Call Number c:irua:133775 Serial 4074
Permanent link to this record
 

 
Author Filippousi, M.; Turner, S.; Leus, K.; Siafaka, P.I.; Tseligka, E.D.; Vandichel, M.; Nanaki, S.G.; Vizirianakis, I.S.; Bikiaris, D.N.; Van Der Voort, P.; Van Tendeloo, G.
Title Biocompatible Zr-based nanoscale MOFs coated with modified poly(epsilon-caprolactone) as anticancer drug carriers Type A1 Journal article
Year 2016 Publication International journal of pharmaceutics Abbreviated Journal Int J Pharmaceut
Volume 509 Issue 509 Pages 208-218
Keywords A1 Journal article; Pharmacology. Therapy; Electron microscopy for materials research (EMAT)
Abstract (up) Nanoscale Zr-based metal organic frameworks (MOFs) UiO-66 and UiO-67 were studied as potential anticancer drug delivery vehicles. Two model drugs were used, hydrophobic paclitaxel and hydrophilic cisplatin, and were adsorbed onto/into the nano MOFs (NMOFs). The drug loaded MOFs were further encapsulated inside a modified poly(epsilon-caprolactone) with d-alpha-tocopheryl polyethylene glycol succinate polymeric matrix, in the form of microparticles, in order to prepare sustained release formulations and to reduce the drug toxicity. The drugs physical state and release rate was studied at 37 degrees C using Simulated Body Fluid. It was found that the drug release depends on the interaction between the MOFs and the drugs while the controlled release rates can be attributed to the microencapsulated formulations. The in vitro antitumor activity was assessed using HSC-3 (human oral squamous carcinoma; head and neck) and U-87 MG (human glioblastoma grade IV; astrocytoma) cancer cells. Cytotoxicity studies for both cell lines showed that the polymer coated, drug loaded MOFs exhibited better anticancer activity compared to free paclitaxel and cisplatin solutions at different concentrations.
Address EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000378949800022 Publication Date 2016-05-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0378-5173 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.649 Times cited 37 Open Access
Notes This work is performed within the framework of the IAP-P7/05. S.T. Gratefully acknowledges the Fund for Scientific Research Flanders (FWO). K.L. acknowledges the financial support from the Ghent University BOF postdoctoral grant 01P06813T and UGent GOA Grant 01G00710. Approved Most recent IF: 3.649
Call Number c:irua:134039 Serial 4088
Permanent link to this record
 

 
Author Smets, W.; Moretti, S.; Denys, S.; Lebeer, S.
Title Airborne bacteria in the atmosphere : presence, purpose, and potential Type A1 Journal article
Year 2016 Publication Atmospheric environment : an international journal Abbreviated Journal
Volume 139 Issue Pages 214-221
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (up) Numerous recent studies have highlighted that the types of bacteria present in the atmosphere often show predictable patterns across space and time. These patterns can be driven by differences in bacterial sources of the atmosphere and a wide range of environmental factors, including UV intensity, precipitation events, and humidity. The abundance of certain bacterial taxa is of interest, not only for their ability to mediate a range of chemical and physical processes in the atmosphere, such as cloud formation and ice nucleation, but also for their implications -both beneficial and detrimental-for human health. Consequently, the widespread importance of airborne bacteria has stimulated the search for their applicability. Improving air quality, modelling the dispersal of airborne bacteria (e.g. pathogens) and biotechnological purposes are already being explored. Nevertheless, many technological challenges still need to be overcome to fully understand the roles of airborne bacteria in our health and global ecosystems.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000379093900021 Publication Date 2016-05-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1352-2310 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:133711 Serial 7432
Permanent link to this record
 

 
Author Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J.
Title Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations Type A1 Journal article
Year 2016 Publication Dental materials Abbreviated Journal Dent Mater
Volume 32 Issue 12 Pages E327-E337
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Objective. The aim was to evaluate the optical properties, mechanical properties and aging stability of yttria-stabilized zirconia with different compositions, highlighting the influence of the alumina addition, Y2O3 content and La2O3 doping on the translucency. Methods. Five different Y-TZP zirconia powders (3 commercially available and 2 experimentally modified) were sintered under the same conditions and characterized by X-ray diffraction with Rietveld analysis and scanning electron microscopy (SEM). Translucency (n = 6/group) was measured with a color meter, allowing to calculate the translucency parameter (TP) and the contrast ratio (CR). Mechanical properties were appraised with four-point bending strength (n = 10), single edge V-notched beam (SEVNB) fracture toughness (n = 8) and Vickers hardness (n = 10). The aging stability was evaluated by measuring the tetragonal to monoclinic transformation (n = 3) after accelerated hydrothermal aging in steam at 134 degrees C, and the transformation curves were fitted by the Mehl-Avrami-Johnson (MAJ) equation. Data were analyzed by one-way ANOVA, followed by Tukey's HSD test (alpha = 0.05). Results. Lowering the alumina content below 0.25 wt.% avoided the formation of alumina particles and therefore increased the translucency of 3Y-TZP ceramics, but the hydrothermal aging stability was reduced. A higher yttria content (5 mol%) introduced about 50% cubic zirconia phase and gave rise to the most translucent and aging-resistant Y-TZP ceramics, but the fracture toughness and strength were considerably sacrificed. 0.2 mol% La2O3 doping of 3Y-TZP tailored the grain boundary chemistry and significantly improved the aging resistance and translucency. Although the translucency improvement by La2O3 doping was less effective than for introducing a substantial amount of cubic zirconia, this strategy was able to maintain the mechanical properties of typical 3Y-TZP ceramics. Significance. Three different approaches were compared to improve the translucency of 3YTZP ceramics. (C) 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Copenhagen Editor
Language Wos 000389516400003 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0109-5641 ISBN Additional Links UA library record; WoS full record
Impact Factor 4.07 Times cited 47 Open Access
Notes Approved Most recent IF: 4.07
Call Number UA @ lucian @ c:irua:140246 Serial 4447
Permanent link to this record
 

 
Author Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J.
Title Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations Type A1 Journal article
Year 2016 Publication Dental Materials Abbreviated Journal Dent Mater
Volume 32 Issue 32 Pages e327-e337
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract (up) OBJECTIVE: The aim was to evaluate the optical properties, mechanical properties and aging stability of yttria-stabilized zirconia with different compositions, highlighting the influence of the alumina addition, Y2O3 content and La2O3 doping on the translucency. METHODS: Five different Y-TZP zirconia powders (3 commercially available and 2 experimentally modified) were sintered under the same conditions and characterized by X-ray diffraction with Rietveld analysis and scanning electron microscopy (SEM). Translucency (n=6/group) was measured with a color meter, allowing to calculate the translucency parameter (TP) and the contrast ratio (CR). Mechanical properties were appraised with four-point bending strength (n=10), single edge V-notched beam (SEVNB) fracture toughness (n=8) and Vickers hardness (n=10). The aging stability was evaluated by measuring the tetragonal to monoclinic transformation (n=3) after accelerated hydrothermal aging in steam at 134 degrees C, and the transformation curves were fitted by the Mehl-Avrami-Johnson (MAJ) equation. Data were analyzed by one-way ANOVA, followed by Tukey's HSD test (alpha=0.05). RESULTS: Lowering the alumina content below 0.25wt.% avoided the formation of alumina particles and therefore increased the translucency of 3Y-TZP ceramics, but the hydrothermal aging stability was reduced. A higher yttria content (5mol%) introduced about 50% cubic zirconia phase and gave rise to the most translucent and aging-resistant Y-TZP ceramics, but the fracture toughness and strength were considerably sacrificed. 0.2mol% La2O3 doping of 3Y-TZP tailored the grain boundary chemistry and significantly improved the aging resistance and translucency. Although the translucency improvement by La2O3 doping was less effective than for introducing a substantial amount of cubic zirconia, this strategy was able to maintain the mechanical properties of typical 3Y-TZP ceramics. SIGNIFICANCE: Three different approaches were compared to improve the translucency of 3Y-TZP ceramics.
Address KU Leuven, Department of Materials Engineering, Kasteelpark Arenberg 44, Belgium
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000389516400003 Publication Date 2016-10-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0109-5641 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.07 Times cited Open Access
Notes The authors acknowledge the Research Fund of KU Leu- ven under project 0T/10/052 and the Fund for Scientific Research Flanders (FWO-Vlaanderen) under grant G.0431.10N. F. Zhang thanks the Research Fund of KU Leuven for her post- doctoral fellowship (PDM/15/153). We thank M. Peumans for the translucency measurements. Approved Most recent IF: 4.07
Call Number EMAT @ emat @ c:irua:136821 Serial 4313
Permanent link to this record
 

 
Author Mirzakhani, M.; Zarenia, M.; Ketabi, S.A.; da Costa, D.R.; Peeters, F.M.
Title Energy levels of hybrid monolayer-bilayer graphene quantum dots Type A1 Journal article
Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 93 Issue 93 Pages 165410
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Often real samples of graphene consist of islands of both monolayer and bilayer graphene. Bound states in such hybrid quantum dots are investigated for (i) a circular single-layer graphene quantum dot surrounded by an infinite bilayer graphene sheet and (ii) a circular bilayer graphene quantum dot surrounded by an infinite single-layer graphene. Using the continuum model and applying zigzag boundary conditions at the single-layer-bilayer graphene interface, we obtain analytical results for the energy levels and the corresponding wave spinors. Their dependence on perpendicular magnetic and electric fields are studied for both types of quantum dots. The energy levels exhibit characteristics of interface states, and we find anticrossings and closing of the energy gap in the presence of a bias potential.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000373572700004 Publication Date 2016-04-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950;2469-9969; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 26 Open Access
Notes ; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO)-CNPq project between Flanders and Brazil and the Brazilian Science Without Borders program. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:133261 Serial 4174
Permanent link to this record
 

 
Author Van Havenbergh, K.; Turner, S.; Marx, N.; Van Tendeloo, G.
Title The mechanical behavior during (de)lithiation of coated silicon nanoparticles as anode material for lithium-ion batteries studied by InSitu transmission electron microscopy Type A1 Journal article
Year 2016 Publication Energy technology Abbreviated Journal Energy Technol-Ger
Volume 4 Issue 4 Pages 1005-1012
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (up) One approach to cope with the continuous irreversible capacity loss in Si-based electrodes, attributed to lithiation-induced volume changes and the formation of a solid-electrolyte interface (SEI), is by coating silicon nanoparticles. A coating can improve the conductivity of the electrode, form a chemical shield against the electrolyte, or provide mechanical confinement to reduce the volume increase. The influence of such a coating on the mechanical behavior of silicon nanoparticles during Li insertion and Li extraction was investigated by insitu transmission electron microscopy. The type of coating was shown to influence the size of the unreacted core that remains after reaction of silicon with lithium. Furthermore, two mechanisms to relieve the stress generated during volume expansion are reported: the initiation of cracks and the formation of nanovoids. Both result in a full reaction of the silicon nanoparticles, whereas with the formation of cracks, additional surface area is created, on which an SEI can be formed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000382549500012 Publication Date 2016-06-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2194-4296; 2194-4288 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.789 Times cited 6 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:137167 Serial 4406
Permanent link to this record
 

 
Author Schalm, O.; Anaf, W.
Title Laminated altered layers in historical glass : density variations of silica nanoparticle random packings as explanation for the observed lamellae Type A1 Journal article
Year 2016 Publication Journal of non-crystalline solids Abbreviated Journal
Volume 442 Issue Pages 1-16
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES)
Abstract (up) One of the most striking but unexplained phenomena in the natural degradation of glass is the transformation of an almost colorless, transparent and homogeneous glass into a colored, opaque and heterogeneous degradation layer. In many cases, the degradation layer consists of numerous lamellae with a thickness between 0.1 and 10 pm. However, both internal structure and formation proess of laminated degradation layers remain unclear. In this paper, a model is proposed where we assume that transformed (degraded) glass consists of a random packing of nano-sized silica particles while the lamellae are the result of different packing densities. The model is able to connect the texture of numerous lamellae observed by several types of microscopic techniques with the structure at molecular level determined by means of chemical analysis. In addition, the model is able to explain numerous properties such as the parameters responsible for the contrast between lamellae. This contrast can be caused by differences in color, density, elemental composition, or surface roughness. (C) 2016 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000375809800001 Publication Date 2016-04-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3093 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:133634 Serial 8146
Permanent link to this record
 

 
Author Altantzis, T.; Coutino-Gonzalez, E.; Baekelant, W.; Martinez, G.T.; Abakumov, A.M.; Van Tendeloo, G.; Roeffaers, M.B.J.; Bals, S.; Hofkens, J.
Title Direct Observation of Luminescent Silver Clusters Confined in Faujasite Zeolites Type A1 Journal article
Year 2016 Publication ACS nano Abbreviated Journal Acs Nano
Volume 10 Issue 10 Pages 7604-7611
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) One of the ultimate goals in the study of metal clusters is the correlation between the atomic-scale organization and their physicochemical properties. However, direct observation of the atomic organization of such minuscule metal clusters is heavily hindered by radiation damage imposed by the different characterization techniques. We present direct evidence of the structural arrangement, at an atomic level, of luminescent silver species stabilized in faujasite (FAU) zeolites using aberration-corrected scanning transmission electron microscopy. Two different silver clusters were identified in Ag-FAU zeolites, a trinuclear silver species associated with green emission and a tetranuclear silver species related to yellow emission. By combining direct imaging with complementary information obtained from X-ray powder diffraction and Rietveld analysis, we were able to elucidate the main differences at an atomic scale between luminescent (heat-treated) and nonluminescent (cation-exchanged) Ag-FAU zeolites. It is expected that such insights will trigger the directed synthesis of functional metal nanocluster-zeolite composites with tailored luminescent properties.
Address RIES, Hokkaido University , N20W10, Kita-Ward Sapporo 001-0020, Japan
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000381959100043 Publication Date 2016-07-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 57 Open Access OpenAccess
Notes The authors gratefully acknowledge financial support from the Belgian Federal government (Belspo through the IAP-VI/27 and IAP-VII/05 programs), the European Union’s Seventh Framework Programme (FP7/2007-2013 under grant agreement no. 310651 SACS and no. 312483-ESTEEM2), the Flemish government in the form of long-term structural funding “Methusalem” grant METH/15/04 CASAS2, the Hercules foundation (HER/11/14), the “Strategisch Initiatief Materialen” SoPPoM program, and the Fund for Scientific Research Flanders (FWO) grants G.0349.12 and G.0B39.15. S.B. acknowledges funding from ERC Starting Grant COLOURATOMS (335078). The authors thank Prof. S. Van Aert for helpful discussions, Dr. T. De Baerdemaeker for XRD measurements, Mr. B. Dieu for the preparation of graphical material, and UOP Antwerp for the kind donation of zeolite samples.; esteem2jra4; ECASSara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 13.942
Call Number c:irua:134576 c:irua:134576 Serial 4102
Permanent link to this record
 

 
Author Altantzis, T.; Yang, Z.; Bals, S.; Van Tendeloo, G.; Pileni, M.-P.
Title Thermal Stability of CoAu13Binary Nanoparticle Superlattices under the Electron Beam Type A1 Journal article
Year 2016 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 28 Issue 28 Pages 716-719
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) One primary goal of self-assembly in nanoscale regime is to implement multifunctional binary nanoparticle superlattices into practical use. In the last decade, considerable effort has been put into the fabrication of binary nanoparticle superlattices with controllable structure and stoichiometry. However, limited effort has been made in order to improve the stability of these binary nanoparticle superlattices, which is a prerequisite for their potential application. In this work, we demonstrate that the carbon deposition from specimen contamination can play an auxiliary role during the heat treatment of binary nanoparticle superlattices. With the in-situ carbon matrix formation, the thermal stability of CoAu 13 binary nanoparticle superlattices is unambiguously enhanced.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000370112200007 Publication Date 2016-01-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 10 Open Access OpenAccess
Notes The research leading to these results has been supported by an Advanced Grant of the European Research Council under Grant 267129. The authors appreciate financial support by theEuropean Union under the Framework 7 program under a contract for an Integrated Infrastructure Initiative (Reference No. 262348 ESMI). S.B. acknowledges funding from ERC Starting Grant COLOURATOMS (335078).; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 9.466
Call Number c:irua:131908 Serial 4040
Permanent link to this record
 

 
Author Ben Dkhil, S.; Pfannmöller, M.; Bals, S.; Koganezawa, T.; Yoshimoto, N.; Hannani, D.; Gaceur, M.; Videlot-Ackermann, C.; Margeat, O.; Ackermann, J.
Title Square-centimeter-sized high-efficiency polymer solar cells : how the processing atmosphere and film quality influence performance at large scale Type A1 Journal article
Year 2016 Publication Laser physics review Abbreviated Journal Adv Energy Mater
Volume 6 Issue 6 Pages 1600290
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (up) Organic solar cells based on two benzodithiophene-based polymers (PTB7 and PTB7-Th) processed at square centimeter-size under inert atmosphere and ambient air, respectively, are investigated. It is demonstrated that the performance of solar cells processed under inert atmosphere is not limited by the upscaling of photoactive layer and the interfacial layers. Thorough morphological and electrical characterizations of optimized layers and corresponding devices reveal that performance losses due to area enlargement are only caused by the sheet resistance of the transparent electrode reducing the effi ciency from 9.3% of 7.8% for PTB7-Th in the condition that both photoactive layer and the interfacial layers are of high layer quality. Air processing of photoactive layer and the interfacial layers into centimeter-sized solar cells lead to additional, but only slight, losses (< 10%) in all photovoltaic parameters, which can be addressed to changes in the electronic properties of both active layer and ZnO layers rather than changes in layer morphology. The demonstrated compatibility of polymer solar cells using solution-processed photoactive layer and interfacial layers with large area indicates that the introduction of a standard active area of 1 cm(2) for measuring effi ciency of organic record solar cells is feasible. However electric standards for indium tin oxides (ITO) or alternative transparent electrodes need to be developed so that performance of new photovoltaic materials can be compared at square centimeter-size.
Address
Corporate Author Thesis
Publisher Place of Publication Place of publication unknown Editor
Language Wos 000379314700010 Publication Date 2016-05-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1614-6832 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 16.721 Times cited 6 Open Access Not_Open_Access
Notes ; The authors acknowledge financial support by the French Fond Unique Intermisteriel (FUI) under the project “SFUMATO” (Grant number: F1110019V/ 201308815) as well as by the European Commission under the Project “SUNFLOWER” (FP7-ICT-2011-7-contract no. 287594). Generalitat Valenciana (ISIC/2012/008 Institute of Nanotechnologies for Clean Energies) is also acknowledged for providing financial support. The synchrotron radiation experiments were performed at BL46XU and BL19B2 in SPring-8 with the approval of Japan Synchrotron Radiation Research Institute (JASRI) (Proposal Nos. 2014B1916 and 2015A1984). The authors further acknowledge financial support from the European Research Council (ERC Starting Grant #335078-COLOURATOMS). ; Approved Most recent IF: 16.721
Call Number UA @ lucian @ c:irua:134951 Serial 4249
Permanent link to this record
 

 
Author Geuchies, J.J.; van Overbeek, C.; Evers, W.H.; Goris, B.; de Backer, A.; Gantapara, A.P.; Rabouw, F.T.; Hilhorst, J.; Peters, J.L.; Konovalov, O.; Petukhov, A.V.; Dijkstra, M.; Siebbeles, L.D.A.; van Aert, S.; Bals, S.; Vanmaekelbergh, D.
Title In situ study of the formation mechanism of two-dimensional superlattices from PbSe nanocrystals Type A1 Journal article
Year 2016 Publication Nature materials Abbreviated Journal Nat Mater
Volume 15 Issue 15 Pages 1248-1254
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Oriented attachment of PbSe nanocubes can result in the formation of two-dimensional (2D) superstructures with long-range nanoscale and atomic order. This questions the applicability of classic models in which the superlattice grows by first forming a nucleus, followed by sequential irreversible attachment of nanocrystals, as one misaligned attachment would disrupt the 2D order beyond repair. Here, we demonstrate the formation mechanism of 2D PbSe superstructures with square geometry by using in situ grazing-incidence X-ray scattering (small angle and wide angle), ex situ electron microscopy, and Monte Carlo simulations. We observed nanocrystal adsorption at the liquid/gas interface, followed by the formation of a hexagonal nanocrystal monolayer. The hexagonal geometry transforms gradually through a pseudo-hexagonal phase into a phase with square order, driven by attractive interactions between the {100} planes perpendicular to the liquid substrate, which maximize facet-to-facet overlap. The nanocrystals then attach atomically via a necking process, resulting in 2D square superlattices.
Address Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000389104400011 Publication Date 2016-09-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1476-1122 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 39.737 Times cited 182 Open Access OpenAccess
Notes This research is part of the programme ‘Designing Dirac Carriers in semiconductor honeycomb superlattices (DDC13),’ which is supported by the Foundation for Fundamental Research on Matter (FOM), which is part of the Dutch Research Council (NWO). J.J.G. acknowledges funding from the Debye and ESRF Graduate Programs. The authors gratefully acknowledge funding from the Research Foundation Flanders (G.036915 G.037413 and funding of postdoctoral grants to B.G. and A.d.B). S.B. acknowledges the European Research Council, ERC grant No 335078—Colouratom. The authors gratefully acknowledge I. Swart and M. van Huis for fruitful discussions. We acknowledge funding from NWO-CW TOPPUNT ‘Superficial Superstructures’. The X-ray scattering measurements were performed at the ID10 beamline at ESRF under proposal numbers SC-4125 and SC-3786. The authors thank G. L. Destri and F. Zontone for their support during the experiments.; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); Approved Most recent IF: 39.737
Call Number EMAT @ emat @ c:irua:136165 Serial 4289
Permanent link to this record
 

 
Author Vermeulen, M.; Nuyts, G.; Sanyova, J.; Vila, A.; Buti, D.; Suuronen, J.-P.; Janssens, K.
Title Visualization of As(III) and As(V) distributions in degraded paint micro-samples from Baroque- and Rococo-era paintings Type A1 Journal article
Year 2016 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 31 Issue 9 Pages 1913-1921
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (up) Orpiment and realgar, both arsenic sulfide pigments respectively used for their vivid yellow and red-orange hues, are two of many artists' pigments that appear not to be stable upon light exposure, quickly degrading to arsenic trioxide and arsenate. This often results in whitening or transparency in the painted surfaces. While conventional techniques such as microscopic Raman (mu-RS) and microscopic Fourier transform infrared (mu-FTIR) spectroscopies can allow a quick and relatively easy identification of the orpiment, realgar, artificial arsenic sulfide glass and, to some extent, arsenic oxide, the identification and visualization of distributions of the degradation products – and especially arsenate compounds – in the paint micro-samples is generally more challenging. This challenge is due to the rather unfavorable limit of detection and low spectral resolution of such conventional spectroscopic techniques. This restricts the conclusions that can be drawn regarding the conservation state of valuable works of art. In this paper, we present how synchrotron radiation (SR) based techniques can overcome this challenge while working on painting cross-sections taken from a 17th-century painting by the Flemish artist Daniel Seghers (oil on canvas, Statens Museum for Kunst, Denmark) and an 18th-century French Chinoiserie (private collection, France). SR micro-X-ray fluorescence (m-XRF) mapping analysis performed on a visually degraded orpiment-containing paint stratigraphy reveals that arsenic is distributed throughout the entire cross-section, while X-ray absorption near edge structure (mu-XANES) demonstrated that the arsenic is present in both arsenite (As-III) and arsenate (As-V) forms. The latter compound(s), despite being barely identifiable by means of FTIR, were not only located at the surface of large and partially altered grains of arsenic sulfide but also spread throughout the entire paint stratigraphy. Their presence and distribution are attributed either to the complete degradation of smaller arsenic sulfide grains or to migration of the arsenates within the paint layer away from their original location of formation. The combination of mu-XRF and mu-XANES was very useful for the characterization of the advanced degradation state of the arsenic-containing pigments in paint systems; this type of information could not be obtained by means of conventional spectroscopic methods of microanalysis.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000382071200017 Publication Date 2016-08-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 20 Open Access
Notes ; This research is made possible with the support of the Belgian Science Policy Office (BELSPO) through the research program Science for a Sustainable Development – SDD, “Long-term role and fate of metal-sulfides in painted works of art – S2ART” (SD/RI/04A). The CATS gratefully acknowledge VILLUM FONDEN and VELUX FONDEN for infra-structural financial support as well as Anne Haack Christensen, Hannah Tempest and Johanne M. Nielsen for their help and suggestions. The European Synchrotron Radiation Facility is acknowledged for provision of synchrotron radiation facilities. ; Approved Most recent IF: 3.379
Call Number UA @ admin @ c:irua:135691 Serial 5907
Permanent link to this record
 

 
Author Bals, S.; Goris, B.; de Backer, A.; Van Aert, S.; Van Tendeloo, G.
Title Atomic resolution electron tomography Type A1 Journal article
Year 2016 Publication MRS bulletin Abbreviated Journal Mrs Bull
Volume 41 Issue 41 Pages 525-530
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Over the last two decades, three-dimensional (3D) imaging by transmission electron microscopy or “electron tomography” has evolved into a powerful tool to investigate a variety of nanomaterials in different fields, such as life sciences, chemistry, solid-state physics, and materials science. Most of these results were obtained with nanometer-scale resolution, but different approaches have recently pushed the resolution to the atomic level. Such information is a prerequisite to understand the specific relationship between the atomic structure and the physicochemical properties of (nano) materials. We provide an overview of the latest progress in the field of atomic-resolution electron tomography. Different imaging and reconstruction approaches are presented, and state-of-the-art results are discussed. This article demonstrates the power and importance of electron tomography with atomic-scale resolution.
Address
Corporate Author Thesis
Publisher Place of Publication Pittsburgh, Pa Editor
Language Wos 000382508100012 Publication Date 2016-07-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0883-7694 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.199 Times cited 19 Open Access OpenAccess
Notes ; The authors gratefully acknowledge funding from the Research Foundation Flanders (G.0381.16N, G.036915, G.0374.13, and funding of postdoctoral grants to B.G. and A.D.B.). S.B. acknowledges the European Research Council, ERC Grant Number 335078-Colouratom. The research leading to these results received funding from the European Union Seventh Framework Program under Grant Agreements 312483 (ESTEEM2). The authors would like to thank the colleagues who have contributed to this work, including K.J. Batenburg, J. De Beenhouwer, R. Erni, M.D. Rossell, W. Van den Broek, L. Liz-Marzan, E. Carbo-Argibay, S. Gomez-Grana, P. Lievens, M. Van Bael, B. Partoens, B. Schoeters, and J. Sijbers. ; ecas_sara Approved Most recent IF: 5.199
Call Number UA @ lucian @ c:irua:135690 Serial 4299
Permanent link to this record
 

 
Author Rodal-Cedeira, S.; Montes-García, V.; Polavarapu, L.; Solís, D.M.; Heidari, H.; La Porta, A.; Angiola, M.; Martucci, A.; Taboada, J.M.; Obelleiro, F.; Bals, S.; Pérez-Juste, J.; Pastoriza-Santos, I.
Title Plasmonic Au@Pd Nanorods with Boosted Refractive Index Susceptibility and SERS Efficiency: A Multifunctional Platform for Hydrogen Sensing and Monitoring of Catalytic Reactions Type A1 Journal article
Year 2016 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 28 Issue 28 Pages 9169-9180
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Palladium nanoparticles (NPs) have received tremendous attention over the years due to their high catalytic activity for various chemical reactions. However, unlike other noble metal nanoparticles such as Au and Ag NPs, they exhibit poor plasmonic properties with broad extinction spectra and less scattering efficiency, and thus limiting their applications in the field of plasmonics. Therefore, it has been challenging to integrate tunable and strong plasmonic properties into catalytic Pd nanoparticles. Here we show that plasmonic Au@Pd nanorods (NRs) with relatively narrow and remarkably tunable optical responses in the NIR region can be obtained by directional growth of Pd on penta-twinned Au NR seeds. We found the presence of bromide ions facilitates the stabilization of facets for the directional growth of Pd shell to obtain Au@Pd nanorods (NR) with controlled length scales. Interestingly, it turns out the Au NR supported Pd NRs exhibit much narrow extinction compared to pure Pd NRs, which makes them suitable for plasmonic sensing applications. Moreover, these nanostructures display, to the best of our knowledge, one of the highest ensemble refractive index sensitivity values reported to date (1067 nm per refractive index unit, RIU). Additionally, we showed the application of such plasmonic Au@Pd NRs for localized surface plasmon resonance (LSPR)-based sensing of hydrogen both in solution as well as on substrate. Finally, we demonstrate the integration of excellent plasmonic properties in catalytic palladium enables the in situ monitoring of a reaction progress by surface-enhanced Raman scattering. We postulate the proposed approach to boost the plasmonic properties of Pd nanoparticles will ignite the design of complex shaped plasmonic Pd NPs to be used in various plasmonic applications such as sensing and in situ monitoring of various chemical reactions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000391080900036 Publication Date 2016-12-27
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 80 Open Access OpenAccess
Notes Funding from Spanish Ministerio de Economía y Competitividad (Grants MAT2013-45168-R and MAT2016-77809-R) is gratefully acknowledge. A.L.P. and S.B. acknowledge support by the European Research Council through an ERC Starting Grant (#335078-COLOURATOMS). L. P. acknowledges the financial support from by the Alexander von Humboldt-Stiftung. V. M.-G. acknowledges the financial support from FPU scholarship from the Spanish MINECO. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara Approved Most recent IF: 9.466
Call Number EMAT @ emat @ c:irua:139513 Serial 4344
Permanent link to this record
 

 
Author Retuerto, M.; Skiadopoulou, S.; Li, M.R.; Abakumov, A.M.; Croft, M.; Ignatov, A.; Sarkar, T.; Abbett, B.M.; Pokorný, J.; Savinov, M.; Nuzhnyy, D.; Prokleška, J.; Abeykoon, M.; Stephens, P.W.; Hodges, J.P.; Vaněk, P.; Fennie, C.J.; Rabe, K.M.; Kamba, S.; Greenblatt, M.;
Title Pb2MnTeO6 double perovskite : an antipolar anti-ferromagnet Type A1 Journal article
Year 2016 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 55 Issue 55 Pages 4320-4329
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Pb2MnTeO6, a new double perovskite, was synthesized. Its crystal structure was determined by synchrotron X-ray and powder neutron diffraction. Pb2MnTeO6 is monoclinic (I2/m) at room temperature with a regular arrangement of all the cations in their polyhedra. However, when the temperature is lowered to similar to 120 K it undergoes a phase transition from I2/m to C2/c structure. This transition is accompanied by a displacement of the Pb atoms from the center of their polyhedra due to the 6s2 lone-pair electrons, together with a surprising off-centering of Mn2+ (d5) magnetic cations. This strong first-order phase transition is also evidenced by specific heat, dielectric, Raman, and infrared spectroscopy measurements. The magnetic characterizations indicate an anti-ferromagnetic (AFM) order below TN approximate to 20 K; analysis of powder neutron diffraction data confirms the magnetic structure with propagation vector k = (0 1 0) and collinear AFM spins. The observed jump in dielectric permittivity near similar to 150 K implies possible anti-ferroelectric behavior; however, the absence of switching suggests that Pb2MnTeO6 can only be antipolar. First-principle calculations confirmed that the crystal and magnetic structures determined are locally stable and that anti-ferroelectric switching is unlikely to be observed in Pb2MnTeO6.
Address
Corporate Author Thesis
Publisher Place of Publication Easton, Pa Editor
Language Wos 000375519700027 Publication Date 2016-04-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.857 Times cited 9 Open Access
Notes Approved Most recent IF: 4.857
Call Number UA @ lucian @ c:irua:134219 Serial 4258
Permanent link to this record