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“CFD-modelling of activated carbon fibers for indoor air purification”. Roegiers J, Denys S, Chemical engineering journal 365, 80 (2019). http://doi.org/10.1016/J.CEJ.2019.02.007
Abstract: Activated carbon fibers for indoor air purification were investigated by means of pressure drop and adsorption capacity. The Darcy-Forchheimer law combined with Computational Fluid Dynamics (CFD) modelling was deployed to simulate the pressure drop over an activated carbon fiber (ACF) filter with varying filter thickness. The CFD model was later combined with adsorption modelling to simulate breakthrough profiles of acetaldehyde adsorption on the ACF-filter. The adsorption model incorporates mass transfer resistance and adsorption equilibrium. It assumes local equilibrium between gas phase and solid phase. The latter was investigated for three different adsorption isotherms: linear, Langmuir and Freundlich adsorption. Successful agreement between model simulations and experimental data was obtained, using the Freundlich adsorption model. The numerical model could provide valuable insights and allows to continuously improve the design of filtration devices.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.CEJ.2019.02.007
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“MnFe0.5Ru0.5O3 : an above-room-temperature antiferromagnetic semiconductor”. Tan X, McCabe EE, Orlandi F, Manuel P, Batuk M, Hadermann J, Deng Z, Jin C, Nowik I, Herber R, Segre CU, Liu S, Croft M, Kang C-J, Lapidus S, Frank CE, Padmanabhan H, Gopalan V, Wu M, Li M-R, Kotliar G, Walker D, Greenblatt M, Journal of materials chemistry C : materials for optical and electronic devices 7, 509 (2019). http://doi.org/10.1039/C8TC05059G
Abstract: A transition-metal-only MnFe0.5Ru0.5O3 polycrystalline oxide was prepared by a reaction of starting materials MnO, MnO2, Fe2O3, RuO2 at 6 GPa and 1873 K for 30 minutes. A combination of X-ray and neutron powder diffraction refinements indicated that MnFe0.5Ru0.5O3 adopts the corundum (alpha-Fe2O3) structure type with space group R (3) over barc, in which all metal ions are disordered. The centrosymmetric nature of the MnFe0.5Ru0.5O3 structure is corroborated by transmission electron microscopy, lack of optical second harmonic generation, X-ray absorption near edge spectroscopy, and Mossbauer spectroscopy. X-ray absorption near edge spectroscopy of MnFe0.5Ru0.5O3 showed the oxidation states of Mn, Fe, and Ru to be 2+/3+, 3+, and similar to 4+, respectively. Resistivity measurements revealed that MnFe0.5Ru0.5O3 is a semiconductor. Magnetic measurements and magnetic structure refinements indicated that MnFe0.5Ru0.5O3 orders antiferromagnetically around 400 K, with magnetic moments slightly canted away from the c axis. Fe-57 Mossbauer confirmed the magnetic ordering and Fe3+ (S = 5/2) magnetic hyperfine splitting. First principles calculations are provided to understand the electronic structure more thoroughly. A comparison of synthesis and properties of MnFe0.5Ru0.5O3 and related corundum Mn2BB'O-6 derivatives is discussed.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.256
Times cited: 1
DOI: 10.1039/C8TC05059G
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“Cephalosporin antibiotics : electrochemical fingerprints and core structure reactions investigated by LC-MSMS”. Sleegers N, van Nuijs ALN, van den Berg M, De Wael K, Analytical chemistry 91, 2035 (2019). http://doi.org/10.1021/ACS.ANALCHEM.8B04487
Abstract: Electrochemistry and exploiting electrochemical fingerprints is a potent approach to address newly emerging surveillance needs, for instance for antibiotics. However, a comprehensive insight in the electrochemical oxidation behaviour and mechanism is re-quired for this sensing strategy. To address the lack in knowledge of the voltammetric behaviour of the cephalosporins antibiotics, a selection of cephalosporin antibiotics and two main intermediates were subjected to an electrochemical study of their redox behaviour by means of pulsed voltammetric techniques and small-scale electrolysis combined with HPLC-MS/MS analyses. Sur-prisingly, the detected oxidation products did not fit the earlier suggested oxidation of the sulfur group to the corresponding sul-foxide. The influence of different side chains, both at the three and the seven position of the β-lactam core structure on the elec-trochemical fingerprint were investigated. Additional oxidation signals at lower potentials were elucidated and linked to different side chains. These signals were further exploited to allow simultaneous detection of different cephalosporins in one voltammetric sweep. These fundamental insights can become the building blocks for an new on-site screening method.
Keywords: A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre
Impact Factor: 6.32
Times cited: 6
DOI: 10.1021/ACS.ANALCHEM.8B04487
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“Atmospheric pressure glow discharge for CO2 conversion : model-based exploration of the optimum reactor configuration”. Trenchev G, Nikiforov A, Wang W, Kolev S, Bogaerts A, Chemical engineering journal 362, 830 (2019). http://doi.org/10.1016/J.CEJ.2019.01.091
Abstract: We investigate the performance of an atmospheric pressure glow discharge (APGD) reactor for CO2 conversion in three different configurations, through experiments and simulations. The first (basic) configuration utilizes the well-known pin-to-plate design, which offers a limited conversion. The second configuration improves the reactor performance by employing a vortex-flow generator. The third, “confined” configuration is a complete redesign of the reactor, which encloses the discharge in a limited volume, significantly surpassing the conversion rate of the other two designs. The plasma properties are investigated using an advanced plasma model.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.216
Times cited: 4
DOI: 10.1016/J.CEJ.2019.01.091
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“A systematic study of various 2D materials in the light of defect formation and oxidation”. Dabral A, Lu AKA, Chiappe D, Houssa M, Pourtois G, Physical chemistry, chemical physics 21, 1089 (2019). http://doi.org/10.1039/C8CP05665J
Abstract: The thermodynamic aspects of various 2D materials are explored using Density Functional Theory (DFT). Various metal chalcogenides (MX2, M = metal, chalcogen X = S, Se, Te) are investigated with respect to their interaction and stability under different ambient conditions met in the integration process of a transistor device. Their interaction with high- dielectrics is also addressed, in order to assess their possible integration in Complementary Metal Oxide Semiconductor (CMOS) field effect transistors. 2D materials show promise for high performance nanoelectronic devices, but the presence of defects (vacancies, grain boundaries,...) can significantly impact their electronic properties. To assess the impact of defects, their enthalpies of formation and their signature levels in the density of states have been studied. We find, consistently with literature reports, that chalcogen vacancies are the most likely source of defects. It is shown that while pristine 2D materials are in general stable whenever set in contact with different ambient atmospheres, the presence of defective sites affects the electronic properties of the 2D materials to varying degrees. We observe that all the 2D materials studied in the present work show strong reactivity towards radical oxygen plasma treatments while reactivity towards other common gas phase chemical such as O-2 and H2O and groups present at the high- surface varies significantly between species. While energy band-gaps, effective masses and contact resistivities are key criteria in selection of 2D materials for scaled CMOS and tunneling based devices, the phase and ambient stabilities might also play a very important role in the development of reliable nanoelectronic applications.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.123
Times cited: 1
DOI: 10.1039/C8CP05665J
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“Enzymatic sensor for phenols based on titanium dioxide generating surface confined ROS after treatment with H2O2”. Rahemi V, Trashin S, Hafideddine Z, Meynen V, Van Doorslaer S, De Wael K, Sensors and actuators : B : chemical 283, 343 (2019). http://doi.org/10.1016/J.SNB.2018.12.039
Abstract: Titanium dioxide (TiO2) is a popular material as host matrix for enzymes. We now evidence that TiO2 can accumulate and retain reactive oxygen species after treatment by hydrogen peroxide (H2O2) and support redox cycling of a phenolic analyte between horseradish peroxidase (HRP) and an electrode. The proposed detection scheme is identical to that of second generation biosensors, but the measuring solution requires no dissolved H2O2. This significantly simplifies the analysis and overcomes issues related to H2O2 being present (or generated) in the solution. The modified electrodes showed rapid stabilization of the baseline, a low noise level, fast realization of a steady-state current response, and, in addition, improved sensitivity and limit of detection compared to the conventional approach, i.e. in the presence of H2O2 in the measuring solution. Hydroquinone, 4-aminophenol, and other phenolic compounds were successfully detected at sub-μM concentrations. Particularly, a linear response in the concentration range between 0.025 and 2 μM and LOD of 24 nM was demonstrated for 4-aminophenol. The proposed sensor design goes beyond the traditional concept with three sensors generations offering a new possibility for the development of enzymatic sensors based on peroxidases and the formation of ROS on titania after treatment with H2O2.
Keywords: A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 5.401
Times cited: 1
DOI: 10.1016/J.SNB.2018.12.039
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“Enhanced carbon and nitrogen removal performance of simultaneous anammox and denitrification (SAD) with mannitol addition treating saline wastewater”. Yang Z, Zhu W, Yu D, Bo Y, Li J, Journal of chemical technology and biotechnology 94, 377 (2019). http://doi.org/10.1002/JCTB.5781
Abstract: BACKGROUND Simultaneous anammox and denitrification (SAD) can remove carbon and nitrogen. However, its performance is suppressed under saline surroundings. In this work, mannitol was used to enhance a SAD process treating saline wastewater. RESULTS The optimum carbon and nitrogen removal was achieved at 0.2 mmol L-1 mannitol, during which ammonium removal efficiency (ARE), nitrite removal efficiency (NRE) and chemical oxygen demand (COD) removal efficiency were 96.95%, 93.70% and 90.05%, respectively. The maximum ammonium removal rate (ARR), nitrite removal rate (NRR) and the specific anammox activity (SAA) were increased by 25.49%, 55.84% and 33.83% with optimum addition (0.2 mmol L-1 mannitol) respectively. The diameter of sludge was enlarged with the addition of mannitol (<= 0.2 mmol L-1). The Tseng-Wayman model was more suitable to simulate the whole SAD process. The modified logistic model, the modified Boltzman model and the modified Gompertz model were all appropriate to describe nitrogen removal in a typical cycle with the addition of mannitol. CONCLUSION Mannitol was effective in enhancing a SAD process treating saline wastewater, and maximum nitrogen removal was achieved at mannitol = 0.2 mmol L-1. The Tseng-Wayman model satisfactorily predicted the whole SAD process treating saline wastewater with mannitol addition. (c) 2018 Society of Chemical Industry
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1002/JCTB.5781
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“Electrochemical strategies for the detection of forensic drugs”. Florea A, De Jong M, De Wael K, Current opinion in electrochemistry 11, 34 (2018). http://doi.org/10.1016/J.COELEC.2018.06.014
Abstract: Illicit drugs consumption and trafficking is spread worldwide and remains an increasing challenge for local authorities. Forensic drugs and their metabolites are released into wastewaters due to human excretion after illegal consumption of drugs and occasionally due to disposal of clandestine laboratory wastes into sewage systems, being recently classified as the latest group of emerging pollutants. Hence, it is essential to have efficient and accurate methods to detect these type of compounds in seized street samples, biological fluids and wastewaters in order to reduce and prevent trafficking and consumption and negative effects on aquatic systems. Electrochemical strategies offer a fast, portable, low-cost and accurate alternative to chromatographic and spectrometric methods, for the analysis of forensic drugs and metabolites in different matrices. Recent electrochemical strategies applied to the detection of illicit drugs in wastewaters, biological fluids and street samples are presented in this review, together with the impact of drug consumption on the environment.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Times cited: 7
DOI: 10.1016/J.COELEC.2018.06.014
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“Reduced Na2+xTi4O9 composite : a durable anode for sodium-ion batteries”. De Sloovere D, Safari M, Elen K, D'Haen J, Drozhzhin OA, Abakumov AM, Simenas M, Banys J, Bekaert J, Partoens B, Van Bael MK, Hardy A, Chemistry of materials 30, 8521 (2018). http://doi.org/10.1021/ACS.CHEMMATER.8B03301
Abstract: Sodium-ion batteries (SIBs) are potential cost-effective solutions for stationary energy storage applications. Unavailability of suitable anode materials, however, is one of the important barriers to the maturity of SIBs. Here, we report a Na2+xTi4O9/C composite as a promising anode candidate for SIBs with high capacity and cycling stability. This anode is characterized by a capacity of 124 mAh g(-1) (plus 11 mAh g(-1) contributed by carbon black), an average discharge potential of 0.9 V vs Na/Na+, a good rate capability and a high stability (89% capacity retention after 250 cycles at a rate of 1 degrees C). The mechanisms of sodium insertion/deinsertion and of the formation of Na2+xTi4O9/C are investigated with the aid of various ex/in situ characterization techniques. The in situ formed carbon is necessary for the formation of the reduced sodium titanate. This synthesis method may enable the convenient synthesis of other composites of crystalline phases with amorphous carbon.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 9.466
Times cited: 7
DOI: 10.1021/ACS.CHEMMATER.8B03301
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“Enhanced stability of single-layer w-Gallenene through hydrogenation”. Badalov SV, Yagmurcukardes M, Peeters FM, Sahin H, The journal of physical chemistry: C : nanomaterials and interfaces 122, 28302 (2018). http://doi.org/10.1021/ACS.JPCC.8B07353
Abstract: Using density functional theory based first-principles calculations, the effect of surface hydrogenation on the structural, dynamical, electronic, and mechanical properties of monolayer washboard-gallenene (w-gallenene) is investigated. It is found that the dynamically stabilized strained monolayer of w-gallenene has a metallic nonmagnetic ground state. Both one-sided and two-sided hydrogenations of w-gallenene suppress its dynamical instability even when unstrained. Unlike one-sided hydrogenated monolayer w-gallenene (os-w-gallenene), two-sided hydrogenated monolayer w-gallenene (ts-w-gallenene) possesses the same crystal structure as w-gallenene. Electronic band structure calculations reveal that monolayers of hydrogenated derivatives of w-gallenene exhibit also metallic nonmagnetic ground state. Moreover, the linear-elastic constants, in-plane stiffness and Poisson ratio, are enhanced by hydrogenation, which is opposite to the behavior of other hydrogenated monolayer crystals. Furthermore, monolayer w-gallenene and ts-w-gallenene remain dynamically stable up to relatively higher biaxial strains as compared to borophene. With its enhanced dynamical stability, robust metallic character, and enhanced linear-elastic properties, hydrogenated monolayer w-gallenene is a potential candidate for nanodevice applications as a two-dimensional flexible metal.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 4.536
Times cited: 20
DOI: 10.1021/ACS.JPCC.8B07353
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“Sensitivity of nanocrystalline tungsten oxide to CO and ammonia gas determined by surface catalysts”. Marikutsa A, Yang L, Rumyantseva M, Batuk M, Hadermann J, Gaskov A, Sensors and actuators : B : chemical 277, 336 (2018). http://doi.org/10.1016/J.SNB.2018.09.004
Abstract: Nanocrystalline tungsten oxide with variable particle size and surface area was synthesized by aqueous deposition and heat treatment for use in resistive gas sensors. Surface modification with 1 wt.% Pd and Ru was performed by impregnation to improve the sensitivity to CO and ammonia. Acid and oxidation surface sites were evaluated by temperature-programmed techniques using probe molecules. The surface acidity dropped with increasing particle size, and was weakly affected by additives. Lower crystallinity of WO3 and the presence of Ru species favoured temperature-programmed reduction of the materials. Modifying WO3 increased its sensitivity, to CO at ambient condition for modification by Pd and to NH3 at elevated temperature for Ru modification. An in situ infrared study of the gas – solid interaction showed that the catalytic additives change the interaction route of tungsten oxide with the target gases and make the reception of detected molecules independent of the semiconductor oxide matrix.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
DOI: 10.1016/J.SNB.2018.09.004
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“Toxicity of iron oxide nanoparticles : size and coating effects”. Abakumov MA, Semkina AS, Skorikov AS, Vishnevskiy DA, Ivanova AV, Mironova E, Davydova GA, Majouga AG, Chekhonin VP, Journal of biochemical and molecular toxicology 32, e22225 (2018). http://doi.org/10.1002/JBT.22225
Abstract: Toxicological research of novel nanomaterials is a major developmental step of their clinical approval. Since iron oxide magnetic nanoparticles have a great potential in cancer treatment and diagnostics, the investigation of their toxic properties is very topical. In this paper we synthesized bovine serum albumin-coated iron oxide nanoparticles with different sizes and their polyethylene glycol derivative. To prove high biocompatibility of obtained nanoparticles the number of in vitro toxicological tests on human fibroblasts and U251 glioblastoma cells was performed. It was shown that albumin nanoparticles' coating provides a stable and biocompatible shell and prevents cytotoxicity of magnetite core. On long exposure times (48 hours), cytotoxicity of iron oxide nanoparticles takes place due to free radical production, but this toxic effect may be neutralized by using polyethylene glycol modification.
Keywords: A1 Journal article; Pharmacology. Therapy; Electron microscopy for materials research (EMAT)
DOI: 10.1002/JBT.22225
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“Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO2Nanomaterials”. Barreca D, Gri F, Gasparotto A, Altantzis T, Gombac V, Fornasiero P, Maccato C, Inorganic Chemistry 57, 14564 (2018). http://doi.org/10.1021/acs.inorgchem.8b02108
Abstract: Among transition metal oxides, MnO2 is of considerable importance for various technological end-uses,from heterogeneous catalysis to gas sensing, owing to its
structural flexibility and unique properties at the nanoscale. In this work, we demonstrate the successful fabrication of supported MnO2 nanomaterials by a catalyst-free, plasmaassisted process starting from a fluorinated manganese(II)
molecular source in Ar/O2 plasmas. A thorough multitechnique characterization aimed at the systematic investigation of material structure, chemical composition, and
morphology revealed the formation of F-doped, oxygendeficient, MnO2-based nanomaterials, with a fluorine content tunable as a function of growth temperature (TG). Whereas phase-pure β-MnO2 was obtained for 100 °C ≤ TG ≤ 300 °C, the formation of mixed phase MnO2 + Mn2O3 nanosystems took place at 400 °C. In addition, the system nano-organization could be finely tailored, resulting in a controllable evolution from wheat-ear columnar arrays to high aspect ratio pointed-tip nanorod assemblies. Concomitantly, magnetic force microscopy analyses suggested the formation of spin domains with features dependent on material morphology. Preliminary tests in Vislight activated photocatalytic degradation of rhodamine B aqueous solutions pave the way to possible applications of the target materials in wastewater purification.
Keywords: A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Impact Factor: 4.857
DOI: 10.1021/acs.inorgchem.8b02108
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“Chemical cutting of perovskite nanowires into single-photon emissive low-aspect-ratio CsPbX3(X = Cl, Br, I) nanorods”. Tong Y, Fu M, Bladt E, Huang H, Richter AF, Wang K, Mueller-Buschbaum P, Bals S, Tamarat P, Lounis B, Feldmann J, Polavarapu L, Angewandte Chemie: international edition in English 57, 16094 (2018). http://doi.org/10.1002/ANIE.201810110
Abstract: Post-synthetic shape-transformation processes provide access to colloidal nanocrystal morphologies that are unattainable by direct synthetic routes. Herein, we report our finding about the ligand-induced fragmentation of CsPbBr3 perovskite nanowires (NWs) into low aspect-ratio CsPbX3 (X = Cl, Br and I) nanorods (NRs) during halide ion exchange reaction with PbX2-ligand solution. The shape transformation of NWs-to-NRs resulted in an increase of photoluminescence efficiency owing to a decrease of nonradiative decay rates. Importantly, we found that the perovskite NRs exhibit single photon emission as revealed by photon antibunching measurements, while it is not detected in parent NWs. This work not only reports on the quantum light emission of low aspect ratio perovskite NRs, but also expands our current understanding of shape-dependent optical properties of perovskite nanocrystals.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 11.994
Times cited: 70
DOI: 10.1002/ANIE.201810110
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“Impedimetric sensing of the immuno-enzymatic reaction of gliadin with a collagen-modified electrode”. Bottari F, Moretto LM, Ugo P, Electrochemistry communications 97, 51 (2018). http://doi.org/10.1016/J.ELECOM.2018.10.011
Abstract: This paper presents a previously unexplored biosensing strategy for detecting gliadin which exploits the crosslinking of gliadin with collagen, catalyzed by transglutaminase at the interfacial electron transfer rate, on a modified electrode. The process is monitored by electrochemical impedance spectroscopy using a glassy carbon electrode coated with a collagen layer. To validate the specificity of the response as well as to eliminate possible interferences from other proteins, such as soy protein or casein, the captured gliadin is further reacted with a specific anti-gliadin antibody. Changes in charge transfer resistance, measured from the Nyquist plots, scale linearly with the gliadin concentration in the range 5-20 mg/L, a range suitable for testing the gliadin concentration in gluten-free food commodities.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.ELECOM.2018.10.011
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“Analysis of Short-Lived Reactive Species in Plasma–Air–Water Systems: The Dos and the Do Nots”. Gorbanev Y, Privat-Maldonado A, Bogaerts A, Analytical Chemistry 90, 13151 (2018). http://doi.org/10.1021/acs.analchem.8b03336
Abstract: This Feature addresses the analysis of the reactive species generated by nonthermal atmospheric
pressure plasmas, which are widely employed in industrial and biomedical research, as well as first
clinical applications. We summarize the progress in detection of plasma-generated short-lived
reactive oxygen and nitrogen species in aqueous solutions, discuss the potential and limitations of
various analytical methods in plasma−liquid systems, and provide an outlook on the possible future
research goals in development of short-lived reactive species analysis methods for a general
nonspecialist audience.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 6.32
Times cited: 17
DOI: 10.1021/acs.analchem.8b03336
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“Supersonic Microwave Plasma: Potential and Limitations for Energy-Efficient CO2Conversion”. Vermeiren V, Bogaerts A, Journal Of Physical Chemistry C 122, 25869 (2018). http://doi.org/10.1021/acs.jpcc.8b08498
Abstract: Supersonic flows provide a high thermodynamic
nonequilibrium, which is crucial for energy-efficient conversion of
CO 2 in microwave plasmas and are therefore of great interest.
However, the effect of the flow on the chemical reactions is poorly
understood. In this work, we present a combined flow and plasma
chemical kinetics model of a microwave CO 2 plasma in a Laval
nozzle setup. The effects of the flow field on the different dissociation
and recombination mechanisms, the vibrational distribution, and the
vibrational transfer mechanism are discussed. In addition, the effect
of experimental parameters, like position of power deposition, outlet
pressure, and specific energy input, on the CO 2 conversion and
energy efficiency is examined. The short residence time of the gas in
the plasma region, the shockwave, and the maximum critical heat,
and thus power, that can be added to the flow to avoid thermal
choking are the main obstacles to reaching high energy efficiencies.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 4.536
Times cited: 5
DOI: 10.1021/acs.jpcc.8b08498
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“Overcoming floc formation limitations in high-rate activated sludge systems”. Van Winckel T, Liu X, Vlaeminck SE, Takács I, Al-Omari A, Sturm B, Kjellerup BV, Murthy SN, De Clippeleir H, Chemosphere 215, 342 (2019). http://doi.org/10.1016/J.CHEMOSPHERE.2018.09.169
Abstract: High-rate activated sludge (HRAS) is an essential cornerstone of the pursuit towards energy positive sewage treatment through maximizing capture of organics. The capture efficiency heavily relies on the degree of solid separation achieved in the clarifiers. Limitations in the floc formation process commonly emerge in HRAS systems, with detrimental consequences for the capture of organics. This study pinpointed and overcame floc formation limitations present in full-scale HRAS reactors. Orthokinetic flocculation tests were performed with varying shear, sludge concentration, and coagulant or flocculant addition. These were analyzed with traditional and novel settling parameters and extracellular polymeric substances (EPS) measurements. HRAS was limited by insufficient collision efficiency and occurred because the solids retention time (SRT) was short and colloid loading was high. The limitation was predominantly caused by impaired flocculation rather than coagulation. In addition, the collision efficiency limitation was driven by EPS composition (low protein over polysaccharide ratio) instead of total EPS amount. Collision efficiency limitation was successfully overcome by bio-augmenting sludge from a biological nutrient removal reactor operating at long SRT which did not show any floc formation limitations. However, this action brought up a floc strength limitation. The latter was not correlated with EPS composition, but rather EPS amount and hindered settling parameters, which determined floc morphology. With this, an analysis toolkit was proposed that will enable design engineers and operators to tackle activated solid separation challenges found in HRAS systems and maximize the recovery potential of the process. (C) 2018 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.CHEMOSPHERE.2018.09.169
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“Small-moment paramagnetism and extensive twinning in the topochemically reduced phase Sr2ReLiO5.5”. Hasanli N, Gauquelin N, Verbeeck J, Hadermann J, Hayward MA, Journal of the Chemical Society : Dalton transactions 47, 15783 (2018). http://doi.org/10.1039/C8DT03463J
Abstract: Reaction of the cation-ordered double perovskite Sr2ReLiO6 with dilute hydrogen at 475 degrees C leads to the topochemical deintercalation of oxide ions from the host lattice and the formation of a phase of composition Sr2ReLiO5.5, as confirmed by thermogravimetric and EELS data. A combination of neutron and electron diffraction data reveals the reduction process converts the -Sr2O2-ReLiO4-Sr2O2-ReLiO4- stacking sequence of the parent phase into a -Sr2O2-ReLiO3-Sr2O2-ReLiO4-, partially anion-vacant ordered sequence. Furthermore a combination of electron diffraction and imaging reveals Sr2ReLiO5.5 exhibits extensive twinning – a feature which can be attributed to the large, anisotropic volume expansion of the material on reduction. Magnetisation data reveal a strongly reduced moment of (eff) = 0.505(B) for the d(1) Re6+ centres in the phase, suggesting there remains a large orbital component to the magnetism of the rhenium centres, despite their location in low symmetry coordination environments.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.029
DOI: 10.1039/C8DT03463J
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“Leaf-deposited semi-volatile organic compounds (SVOCs) : an exploratory study using GCxGC-TOFMS on leaf washing solutions”. Castanheiro A, Joos P, Wuyts K, De Wael K, Samson R, Chemosphere 214, 103 (2019). http://doi.org/10.1016/J.CHEMOSPHERE.2018.09.067
Abstract: Airborne particulate matter (PM) includes semi-volatile organic compounds (SVOCs), which can be deposited on vegetation matrices such as plant leaves. In alternative to air-point measurements or artificial passive substrates, leaf monitoring offers a cost-effective, time-integrating means of assessing local air quality. In this study, leaf washing solutions from ivy (Hedera hibernica) leaves exposed during one-month at different land use classes were explored via comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-TOFMS). The composition of leaf-deposited SVOCs, corrected for those of unexposed leaves, was compared against routinely monitored pollutants concentrations (PM10, PM2.5, O3, NO2, SO2) measured at co-located air monitoring stations. The first study on leaf-deposited SVOCs retrieved from washing solutions, herein reported, delivered a total of 911 detected compounds. While no significant land use (rural, urban, industrial, traffic, mixed) effects were observed, increasing exposure time (from one to 28 days) resulted in a higher number and diversity of SVOCs, suggesting cumulative time-integration to be more relevant than local source variations between sites. After one day, leaf-deposited SVOCs were mainly due to alcohols, N-containing compounds, carboxylic acids, esters and lactones, while ketones, diketones and hydrocarbons compounds gained relevance after one week, and phenol compounds after one month. As leaf-deposited SVOCs became overall more oxidized throughout exposure time, SVOCs transformation or degradation at the leaf surface is suggested to be an important phenomenon. This study confirmed the applicability of GCxGC-TOFMS to analyze SVOCs from leaf washing solutions, further research should include validation of the methodology and comparison with atmospheric organic pollutants.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 4.208
DOI: 10.1016/J.CHEMOSPHERE.2018.09.067
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“Optical readout of controlled monomer-dimer self-assembly”. Tarakanov PA, Tarakanova EN, Dorovatovskii PV, Zubavichus YV, Khrustalev VN, Trashin SA, De Wael K, Neganova ME, Mischenko DV, Sessler JL, Stuzhin PA, Pushkarev VE, Tomilova LG, Journal of the Chemical Society : Dalton transactions 47, 14169 (2018). http://doi.org/10.1039/C8DT00384J
Abstract: 5,7-Substituted 1,4-diazepinoporphyrazine magnesium(II) complexes were synthesized via Mg(II)-alkoxide templated macrocyclization. A single crystal growth synchrotron diffraction analysis permitted what is to our knowledge the first structural characterization of a 1,4-diazepinoporphyrazine. It exists as a dimer in the solid state. In silico calculations supported by solution phase spectral studies involving a series of representative derivatives, provided insights into the factors governing dimerization of 1,4-diazepinoporphyrazines. The present 1,4-diazepinoporphyrazines serve as useful probes for understanding the determinants that guide dimermonomer equilibria and the self-assembly of phthalocyanine derivatives.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Times cited: 4
DOI: 10.1039/C8DT00384J
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“On the control and effect of water content during the electrodeposition of Ni nanostructures from deep eutectic solvents”. Cherigui EAM, Şentosun K, Mamme MH, Lukaczynska M, Terryn H, Bals S, Ustarroz J, The journal of physical chemistry: C : nanomaterials and interfaces 122, 23129 (2018). http://doi.org/10.1021/acs.jpcc.8b05344
Abstract: The electrodeposition of nickel nanostructures on glassy carbon was investigated in 1:2 choline chloride urea deep eutectic solvent (DES) containing different amounts of water. By combining electrochemical techniques, with ex situ field emission scanning electron microscopy, high-angle annular dark field scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy, the effect of water content on the electrochemical processes occurring during nickel deposition was better understood. At highly negative potentials and depending on water content, Ni growth is halted due to water splitting and formation of a mixed layer of Ni/NiOx(OH)(2(1-x)(ads)). Moreover, under certain conditions, the DES components can also be (electro)chemically reduced at the electrode surface, blocking further three-dimensional growth of the Ni NPs. Hence, a two-dimensional crystalline Ni-containing network can be formed in the interparticle region.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.536
Times cited: 27
DOI: 10.1021/acs.jpcc.8b05344
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“Interfacial oxidation and photoluminescence of InP-Based core/shell quantum dots”. Tessier MD, Baquero EA, Dupont D, Grigel V, Bladt E, Bals S, Coppel Y, Hens Z, Nayral C, Delpech F, Chemistry of materials 30, 6877 (2018). http://doi.org/10.1021/ACS.CHEMMATER.8B03117
Abstract: Indium phosphide colloidal quantum dots (QDs) are emerging as an efficient cadmium-free alternative for optoelectronic applications. Recently, syntheses based on easy-to-implement aminophosphine precursors have been developed. We show by solid-state nuclear magnetic resonance spectroscopy that this new approach allows oxide-free indium phosphide core or core/shell quantum dots to be made. Importantly, the oxide-free core/shell interface does not help in achieving higher luminescence efficiencies. We demonstrate that in the case of InP/ZnS and InP/ZnSe QDs, a more pronounced oxidation concurs with a higher photoluminescence efficiency. This study suggests that a II-VI shell on a III-V core generates an interface prone to defects. The most efficient InP/ZnS or InP/ZnSe QDs are therefore made with an oxide buffer layer between the core and the shell: it passivates these interface defects but also results in a somewhat broader emission line width.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 74
DOI: 10.1021/ACS.CHEMMATER.8B03117
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“Determination of intrinsic kinetic parameters in photocatalytic multi-tube reactors by combining the NTUm-method with radiation field modelling”. van Walsem J, Roegiers J, Modde B, Lenaerts S, Denys S, Chemical engineering journal 354, 1042 (2018). http://doi.org/10.1016/J.CEJ.2018.08.010
Abstract: In this work, we propose an adapted Number of Transfer Units (NTUm)-method as an effective tool to determine the Langmuir-Hinshelwood kinetic parameters for a photocatalytic multi-tube reactor. The Langmuir-Hinshelwood rate constant kLH and the Langmuir adsorption constant KL were determined from several experiments under different UV-irradiance conditions, resulting in irradiance depending values for kLH. In order to determine a unique, intrinsic empirical constant k0, valid for all irradiation conditions, we coupled the adapted NTUm-method with a radiation field model to predict UV-irradiance distribution inside the reactor. The final set of kinetic parameters were derived using a Generalized Reduced Gradient (GRG) nonlinear solving method in Matlab which minimizes the differences between model and experimental reactor outlet concentrations of acetaldehyde for various photocatalytic experiments under varying operating conditions, including inlet concentration, flow rate and UV-irradiance. An excellent agreement of the intrinsic empirical constant k0, derived from the coupled NTUm-radiation field model and an earlier published CFD approach was found, emphasizing its validity and reliability.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 6.216
Times cited: 2
DOI: 10.1016/J.CEJ.2018.08.010
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“Enhanced electrochemical performance of Li-rich cathode materials through microstructural control”. Serrano-Sevillano J, Reynaud M, Saracibar A, Altantzis T, Bals S, van Tendeloo G, Casas-Cabanas M, Physical chemistry, chemical physics 20, 23112 (2018). http://doi.org/10.1039/C8CP04181D
Abstract: The microstructural complexity of Li-rich cathode materials has so far hampered understanding the critical link between size, morphology and structural defects with both capacity and voltage fadings that this family of materials exhibits. Li2MnO3 is used here as a model material to extract reliable structure–property
relationships that can be further exploited for the development of high-performing and long-lasting Li-rich oxides. A series of samples with microstructural variability have been prepared and thoroughly characterized using the FAULTS software, which allows quantification of planar defects and extraction of
average crystallite sizes. Together with transmission electron microscopy (TEM) and density functional theory (DFT) results, the successful application of FAULTS analysis to Li2MnO3 has allowed rationalizing the synthesis conditions and identifying the individual impact of concurrent microstructural features on
both voltage and capacity fadings, a necessary step for the development of high-capacity Li-ion cathode materials with enhanced cycle life.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.123
Times cited: 36
DOI: 10.1039/C8CP04181D
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“Kinetics of lifetime changes in bimetallic nanocatalysts revealed by quick X-ray absorption spectroscopy”. Filez M, Poelman H, Redekop EA, Galvita VV, Alexopoulos K, Meledina M, Ramachandran RK, Dendooven J, Detavernier C, Van Tendeloo G, Safonova OV, Nachtegaal M, Weckhuysen BM, Marin GB, Angewandte Chemie: international edition in English 57, 12430 (2018). http://doi.org/10.1002/ANIE.201806447
Abstract: Alloyed metal nanocatalysts are of environmental and economic importance in a plethora of chemical technologies. During the catalyst lifetime, supported alloy nanoparticles undergo dynamic changes which are well-recognized but still poorly understood. High-temperature O-2-H-2 redox cycling was applied to mimic the lifetime changes in model Pt13In9 nanocatalysts, while monitoring the induced changes by insitu quick X-ray absorption spectroscopy with one-second resolution. The different reaction steps involved in repeated Pt13In9 segregation-alloying are identified and kinetically characterized at the single-cycle level. Over longer time scales, sintering phenomena are substantiated and the intraparticle structure is revealed throughout the catalyst lifetime. The insitu time-resolved observation of the dynamic habits of alloyed nanoparticles and their kinetic description can impact catalysis and other fields involving (bi)metallic nanoalloys.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 11.994
Times cited: 4
DOI: 10.1002/ANIE.201806447
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“Impact of the Particle Diameter on Ion Cloud Formation from Gold Nanoparticles in ICPMS”. Fuchs J, Aghaei M, Schachel TD, Sperling M, Bogaerts A, Karst U, Analytical chemistry 90, 10271 (2018). http://doi.org/10.1021/acs.analchem.8b02007
Abstract: The unique capabilities of microsecond dwell time (DT) single-particle inductively coupled plasma mass spectrometry (spICPMS) were utilized to characterize the cloud of ions generated from the introduction of suspensions of gold nanoparticles (AuNPs) into the plasma. A set of narrowly distributed particles with diameters ranging from 15.4 to 100.1 nm was synthesized and characterized according to established protocols. Statistically significant numbers of the short transient spICPMS events were evaluated by using 50 μs DT for their summed intensity, maximum intensity, and duration, of which all three were found to depend on the particle diameter. The summed intensity increases from 10 to 1661 counts and the maximum intensity from 6 to 309 counts for AuNPs with diameters from 15.4 to 83.2 nm. The event duration rises from 322 to 1007 μs upon increasing AuNP diameter. These numbers represent a comprehensive set of key data points of the ion clouds generated in ICPMS from AuNPs. The extension of event duration is of high interest to appoint the maximum possible particle number concentration at which separation of consecutive events in spICPMS can still be achieved. Moreover, the combined evaluation of all above-mentioned ion cloud characteristics can explain the regularly observed prolonged single-particle events. The transport and ionization behavior of AuNPs in the ICP was also computationally modeled to gain insight into the size-dependent signal generation. The simulated data reveals that the plasma temperature, and therefore the point of ionization of the particles, is the same for all diameters. However, the maximum number density of Au+, as well as the extent of the ion cloud, depends on the particle diameter, in agreement with the experimental data, and it provides an adequate explanation for the observed ion cloud characteristics.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.32
Times cited: 5
DOI: 10.1021/acs.analchem.8b02007
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“Monitoring the effect of asymmetrical vertical strain on Janus single layers of MoSSe via spectrum”. Kandemir A, Peeters FM, Sahin H, The journal of chemical physics 149, 084707 (2018). http://doi.org/10.1063/1.5043207
Abstract: Using first principles calculations, we study the structural and phononic properties of the recently synthesized Janus type single layers of molybdenum dichalcogenides. The Janus MoSSe single layer possesses 2H crystal structure with two different chalcogenide sides that lead to out-of-plane anisotropy. By virtue of the asymmetric structure of the ultra-thin Janus type crystal, we induced the out-of-plane anisotropy to show the distinctive vertical pressure effect on the vibrational properties of the Janus material. It is proposed that for the corresponding Raman active optical mode of the Janus structure, the phase modulation and the magnitude ratio of the strained atom and its first neighbor atom adjust the distinctive change in the eigen-frequencies and Raman activity. Moreover, a strong variation in the Raman activity of the Janus structure is obtained under bivertical and univertical strains. Not only eigen-frequency shifts but also Raman activities of the optical modes of the Janus structure exhibit distinguishable features. This study reveals that the vertical anisotropic feature of the Janus structure under Raman measurement allows us to distinguish which side of the Janus crystal interacts with the externals (substrate, functional adlayers, or dopants). Published by AIP Publishing.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.965
Times cited: 11
DOI: 10.1063/1.5043207
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“Hierarchically dual-mesoporous TiO2 microspheres for enhanced photocatalytic properties and lithium storage”. Xiao S, Lu Y, Xiao B-Y, Wu L, Song J-P, Xiao Y-X, Wu S-M, Hu J, Wang Y, Chang G-G, Tian G, Lenaerts S, Janiak C, Yang X-Y, Su B-L, Chemistry: a European journal 24, 13246 (2018). http://doi.org/10.1002/CHEM.201801933
Abstract: Hierarchically dual‐mesoporous TiO2 microspheres have been synthesized via a solvothermal process in the presence of 1‐butyl‐3‐methylmidazolium tetrafluoroborate ([BMIm][BF4]) and diethylenetriamine (DETA) as co‐templates. Secondary mesostructured defects in the hierarchical TiO2 microspheres produce the oxygen vacancies, which not only significantly enhance the photocatalytic activity on degrading methyl blue (over 1.7 times to P25) and acetone (over 2.9 times of P25), but which also are beneficial for lithium storage. Moreover, we propose a mechanism to obtain a better understanding of the role of dual mesoporosity of TiO2 microspheres for enhancing the molecular diffusion, ion transportation and electron transformation.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 5.317
Times cited: 6
DOI: 10.1002/CHEM.201801933
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“Can surface reactivity of mixed crystals be predicted from their counterparts? A case study of (Bi1-xSbx)2Te3 topological insulators”. Volykhov AA, Sanchez-Barriga J, Batuk M, Callaert C, Hadermann J, Sirotina AP, Neudachina VS, Belova AI, Vladimirova NV, Tamm ME, Khmelevsky NO, Escudero C, Perez-Dieste V, Knop-Gericke A, Yashina LV, Journal of materials chemistry C : materials for optical and electronic devices 6, 8941 (2018). http://doi.org/10.1039/C8TC02235F
Abstract: The behavior of ternary mixed crystals or solid solutions and its correlation with the properties of their binary constituents is of fundamental interest. Due to their unique potential for application in future information technology, mixed crystals of topological insulators with the spin-locked, gapless states on their surfaces attract huge attention of physicists, chemists and material scientists. (Bi1-xSbx)(2)Te-3 solid solutions are among the best candidates for spintronic applications since the bulk carrier concentration can be tuned by varying x to obtain truly bulk-insulating samples, where the topological surface states largely contribute to the transport and the realization of the surface quantum Hall effect. As this ternary compound will be evidently used in the form of thin-film devices its chemical stability is an important practical issue. Based on the atomic resolution HAADF-TEM and EDX data together with the XPS results obtained both ex situ and in situ, we propose an atomistic picture of the mixed crystal reactivity compared to that of its binary constituents. We find that the surface reactivity is determined by the probability of oxygen attack on the Te-Sb bonds, which is directly proportional to the number of Te atoms bonded to at least one Sb atom. The oxidation mechanism includes formation of an amorphous antimony oxide at the very surface due to Sb diffusion from the first two quintuple layers, electron tunneling from the Fermi level of the crystal to oxygen, oxygen ion diffusion to the crystal, and finally, slow Te oxidation to the +4 oxidation state. The oxide layer thickness is limited by the electron transport, and the overall process resembles the Cabrera-Mott mechanism in metals. These observations are critical not only for current understanding of the chemical reactivity of complex crystals, but also to improve the performance of future spintronic devices based on topological materials.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.256
Times cited: 3
DOI: 10.1039/C8TC02235F
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