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Ghalei M, Mahdi Khoshouei P, Vandenborre J, Guerard F, Blain G, Zarei M, Haddad F, Fattahi M. How radiolysis impacts astatine speciation? Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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2
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Lazaratou CV, Triantaphyllidou IE, Pantelidis I, Chalkias DA, Kakogiannis G, Vayenas DV, Papoulis D. Using raw and thermally modified fibrous clay minerals as low concentration NH 4+-N adsorbents. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:17737-17756. [PMID: 34676475 DOI: 10.1007/s11356-021-17107-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
Raw and modified fibrous clay minerals palygorskite (Pal) and sepiolite (Sep) were tested for their ability to remove ammonium from ammonium polluted water. Palygorskite and sepiolite underwent thermal treatment at 400°C (T-Pal and T-Sep respectively). Raw and thermally treated samples were characterized using XRD, SEM, BET, FTIR, TGA, zeta potential, and XRF. The techniques verified the effect of thermal treatment on sample structures and the enhancement of negative charge. Both raw and thermally activated materials were applied in batch kinetic experiments, and found to be efficient adsorbents in their raw forms, since Pal and Sep achieved 60 and 80% NH4+-N removal respectively within 20 min of contact for initial NH4+-N concentration of 4 mg/L. Similar removal rates were gained for other concentrations representative of contaminated aquifers that were examined, ranging from 1 to 8 mg/L. Results for the modified T-Pal and T-Sep minerals showed up to 20% higher removal rate. Saturation tests indicated the positive effect of thermal treatment on the minerals since T-Pal and T-Sep removal efficiency reached 85% and remained stable for 24 h. However, competitive ions in real water samples can influence the NH4+-N removal efficiency of the examined samples. At almost all the examined samples, the nonlinear Freundlich isotherm and linear pseudo-second kinetic models showed better fitted all examined samples thus indicating heterogeneous chemisorption.
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Affiliation(s)
| | | | | | - Dimitris A Chalkias
- Nanotechnology & Advanced Materials Laboratory, Department of Electrical and Computer Engineering, University of Peloponnese, GR-26334, Patras, Greece
| | | | - Dimitrios V Vayenas
- Department of Chemical Engineering, University of Patras, GR-26504, Patras, Greece
- Institute of Chemical Engineering Sciences, Foundation for Research and Technology, PO Box 1414, 26504, Patras, GR, Greece
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Investigation of mechanisms of radiolytic H2 production in C-S-H: Influence of water content and radiation induced defects. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2021.109865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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4
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Gianni E, Lazaratou CV, Panagopoulos G, Sarantari P, Martsouka F, Papagiannopoulos K, Panagiotaras D, Papoulis D. Raw and modified palygorskite in water treatment applications for low-concentration ammonium removal. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2021; 93:1979-1994. [PMID: 33835675 DOI: 10.1002/wer.1570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/22/2021] [Accepted: 04/01/2021] [Indexed: 06/12/2023]
Abstract
Raw palygorskite (Pal) samples went under acid (H-Pal), NaCl (Na-Pal), and CaCl2 treatment (Ca-Pal) in order to be examined as ammonium (NH4 + ) sorbents from aqueous solutions. The samples were characterized by XRD and FT-IR techniques to examine potential structural differences after modifications, and batch kinetic experiment series were applied to determine the optimal conditions for NH4 + removal. According to thermodynamic analysis, the removal reaction for sodium- and calcium-treated samples was endothermic (ΔΗ0 > 0, 1.65 kJ/mol and 24.66 kJ/mol, respectively), in contrast with the exothermic reactions of raw and acidic-treated palygorskite samples (ΔΗ0 < 0, -37.18 kJ/mol and -27.56 kJ/mol respectively). Moreover, each sample presented a different order of sorbed ions preference, whereas the strong affinity for Ca2+ sorption was common in all cases since the NH4 + removal inhibited. Nevertheless, a similar pattern was followed for raw and modified samples at isotherm study, rendering the linear form of Freundlich isotherm to express better the NH4 + sorption on palygorskite sample, indicating that it is a heterogeneous procedure. In all cases, the NH4 + maximum uptake was within 15 min using 8 g/L of each sorbent, especially for the Na-Pal sample, which could reach almost 100% removal of low concentration NH4 + . PRACTITIONER POINTS: Modified palygorskite samples were tested for NH4 + removal from aqueous solutions. NaCl-treated palygorskite had the higher removal efficiency, which could reach almost 100% removal of low concentration NH4 + . NH4 + maximum uptake was within 15 minutes using 8 g/L of each sorbent. NH4 + adsorption was an endothermic reaction for NaCl- and CaCl2 -treated palygorskite sorbents. NH4 + adsorption was an exothermic reaction for raw and acid-treated palygorskite sorbents.
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Affiliation(s)
- Eleni Gianni
- Department of Geology, University of Patras, Patras, Greece
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5
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Role of Na+-montmorillonite in the stability of guanine exposed to high-radiation energy in primitive environments: Heterogeneous models. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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6
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Luna CR, Reimers WG, Avena MJ, Juan A. Theoretical study of the octahedral substitution effect in delaminated pyrophyllite: physicochemical properties and applications. Phys Chem Chem Phys 2021; 23:14601-14607. [PMID: 34190255 DOI: 10.1039/d1cp01032h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have studied, using DFT calculations, some geometrical and electronic properties of delaminated pyrophyllite (D-P) and the corresponding layers that result from three isomorphic substitutions on octahedral sheets (Mg2+, Fe2+ and Fe3+). Bond lengths, layer thickness (dL), band gap (Eg), work function (WF), magnetic moment (μ), density of states and charge distributions are reported. These properties are important to control the behaviour of electronic devices. The results show that the layer thickness increases according to the ionic radius of the considered substituent. In the case of the three substitutions a reduction of the forbidden band is observed. Mg2+ induces a decrease in the Eg value of about 16.5% with respect to D-P, whereas for Fe this reduction is more significant due to the presence of trap states in the forbidden zone. For Fe2+ (Fe3+) the reduction in the Eg is around 62% (51%). Regarding the WF, our results showed that there is a decrease in its value after substitution. D-P has the highest WF value (8.15 eV), whereas the delaminated clay with Fe2+ has the lowest value (2.22 eV). Finally, D-P and D-P substituted with Mg2+ have a diamagnetic behaviour (μ = 0), whereas the presence of Fe2+ and Fe3+ induces a paramagnetic behaviour. The computed magnetic moment is 4 μB and 1 μB for D-P substituted with Fe2+ and Fe3+, respectively.
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Affiliation(s)
- Carla Romina Luna
- Instituto de Física del Sur (IFISUR, UNS-CONICET) and Departamento de Física, Universidad Nacional del Sur, Avenida Alem 1253, B8000CPB, Bahía Blanca, Argentina.
| | - Walter Guillermo Reimers
- Instituto de Física del Sur (IFISUR, UNS-CONICET) and Departamento de Física, Universidad Nacional del Sur, Avenida Alem 1253, B8000CPB, Bahía Blanca, Argentina.
| | - Marcelo Javier Avena
- Instituto de Química del Sur (INQUISUR, UNS-CONICET) and Departamento de Química, Universidad Nacional del Sur, Avenida Alem 1253, B8000CPB, Bahía Blanca, Argentina
| | - Alfredo Juan
- Instituto de Física del Sur (IFISUR, UNS-CONICET) and Departamento de Física, Universidad Nacional del Sur, Avenida Alem 1253, B8000CPB, Bahía Blanca, Argentina.
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7
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Puget M, Shcherbakov V, Denisov S, Moreau P, Dognon JP, Mostafavi M, Le Caër S. Reaction Mechanisms of the Degradation of Fluoroethylene Carbonate, an Additive of Lithium-Ion Batteries, Unraveled by Radiation Chemistry. Chemistry 2021; 27:8185-8194. [PMID: 33772902 DOI: 10.1002/chem.202100562] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Indexed: 11/07/2022]
Abstract
Numerous additives are used in the electrolytes of lithium-ion batteries, especially for the formation of an efficient solid electrolyte interphase at the surface of the electrodes. Understanding the degradation processes of these compounds is thus important; they can be seen through radiolysis. In the case of fluoroethylene carbonate (FEC), picosecond pulse radiolysis experiments evidenced the formation of FEC.- . This radical is stabilized in neat FEC, whereas the ring opens to form more stable radical anions when FEC is a solute in other solvents, as confirmed by quantum chemistry calculations. In neat FEC, pre-solvated electrons primarily undergo attachment rather than solvation. On long timescales, the gases produced (H2 , CO, and CO2 ) were quantified. A reaction scheme for both the oxidizing and reducing pathways at stake in irradiated FEC is proposed. This work shows that the nature of the primary species formed in FEC depends on the amount of FEC in the solution.
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Affiliation(s)
- Marin Puget
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191, Gif-sur-Yvette Cedex, France
| | - Viacheslav Shcherbakov
- Institut de Chimie-Physique/ELYSE, UMR 8000 CNRS/Université Paris Saclay, 91405, Orsay Cedex, France
| | - Sergey Denisov
- Institut de Chimie-Physique/ELYSE, UMR 8000 CNRS/Université Paris Saclay, 91405, Orsay Cedex, France
| | - Philippe Moreau
- Institut des Matériaux Jean Rouxel, IMN, Université de Nantes, CNRS, 44000, Nantes, France
| | - Jean-Pierre Dognon
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191, Gif-sur-Yvette Cedex, France
| | - Mehran Mostafavi
- Institut de Chimie-Physique/ELYSE, UMR 8000 CNRS/Université Paris Saclay, 91405, Orsay Cedex, France
| | - Sophie Le Caër
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191, Gif-sur-Yvette Cedex, France
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8
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Hwang J, Pini R. Enhanced Sorption of Supercritical CO 2 and CH 4 in the Hydrated Interlayer Pores of Smectite. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:3778-3788. [PMID: 33734708 DOI: 10.1021/acs.langmuir.1c00375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Understanding the long-term confinement of supercritical fluids in the clay pores of subsurface rocks is important for many geo-energy technologies, including geological CO2 storage. However, the adsorption properties of hydrated clay minerals remain largely uncertain because competitive adsorption experiments of supercritical fluids in the presence of water are difficult. Here, we report on the sorption properties of four source clay minerals-Ca-rich montmorillonite (STx-1b), Na-rich montmorillonite (SWy-2), illite-smectite mixed layer (ISCz-1), and illite (IMt-2)-for water at 20 °C up to relative humidity of 0.9. The measurements unveil the unsuitability of physisorption analysis by N2 (at 77 K) and Ar (at 87 K) gases to quantify the textural properties of clays because of their inability to probe the interlayers. We further measure the sorption of CO2 and CH4 on swelling STx-1b and nonswelling IMt-2, both in the absence (dehydrated at 200 °C) and the presence of sub-1W preadsorbed water (following dehydration) up to 170 bar at 50 °C. We observe enhanced sorption of CO2 and CH4 in STx-1b (50 and 65% increase at 30 bar relative to dry STx-1b, respectively), while their adsorption on IMt-2 remains unchanged, indicating the absence of competition with water. By describing the supercritical adsorption isotherms on hydrated STx-1b with the lattice density functional theory model, we estimate that the pore volume has expanded by approximately 6% through the formation of sub-nanometer pore space. By presenting a systematic approach of quantifying the smectite clay mineral's hydrated state, this study provides an explanation for the conflicting literature observations of gas uptake capacities in the presence of water.
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Affiliation(s)
- Junyoung Hwang
- Department of Chemical Engineering, Imperial College London, SW7 2AZ London, United Kingdom
| | - Ronny Pini
- Department of Chemical Engineering, Imperial College London, SW7 2AZ London, United Kingdom
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9
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Chung SH, Ramirez A, Shoinkhorova T, Mukhambetov I, Abou-Hamad E, Telalovic S, Gascon J, Ruiz-Martínez J. The Importance of Thermal Treatment on Wet-Kneaded Silica-Magnesia Catalyst and Lebedev Ethanol-to-Butadiene Process. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:579. [PMID: 33652611 PMCID: PMC7996789 DOI: 10.3390/nano11030579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 11/16/2022]
Abstract
The Lebedev process, in which ethanol is catalytically converted into 1,3-butadiene, is an alternative process for the production of this commodity chemical. Silica-magnesia (SiO2-MgO) is a benchmark catalyst for the Lebedev process. Among the different preparation methods, the SiO2-MgO catalysts prepared by wet-kneading typically perform best owing to the surface magnesium silicates formed during wet-kneading. Although the thermal treatment is of pivotal importance as a last step in the catalyst preparation, the effect of the calcination temperature of the wet-kneaded SiO2-MgO on the Lebedev process has not been clarified yet. Here, we prepared and characterized in detail a series of wet-kneaded SiO2-MgO catalysts using varying calcination temperatures. We find that the thermal treatment largely influences the type of magnesium silicates, which have different catalytic properties. Our results suggest that the structurally ill-defined amorphous magnesium silicates and lizardite are responsible for the production of ethylene. Further, we argue that forsterite, which has been conventionally considered detrimental for the formation of ethylene, favors the formation of butadiene, especially when combined with stevensite.
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Affiliation(s)
- Sang-Ho Chung
- KAUST Catalysis Center, King Abdullah University of Science and Technology, Catalysis, Nanomaterials, and Spectroscopy (CNS), Thuwal 23955, Saudi Arabia;
| | - Adrian Ramirez
- KAUST Catalysis Center, King Abdullah University of Science and Technology, Advanced Catalytic Materials (ACM), Thuwal 23955, Saudi Arabia; (A.R.); (T.S.); (S.T.); (J.G.)
| | - Tuiana Shoinkhorova
- KAUST Catalysis Center, King Abdullah University of Science and Technology, Advanced Catalytic Materials (ACM), Thuwal 23955, Saudi Arabia; (A.R.); (T.S.); (S.T.); (J.G.)
| | - Ildar Mukhambetov
- KAUST Catalysis Center, King Abdullah University of Science and Technology, Catalysis, Nanomaterials, and Spectroscopy (CNS), Thuwal 23955, Saudi Arabia;
| | - Edy Abou-Hamad
- KAUST Core Labs, King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia;
| | - Selevedin Telalovic
- KAUST Catalysis Center, King Abdullah University of Science and Technology, Advanced Catalytic Materials (ACM), Thuwal 23955, Saudi Arabia; (A.R.); (T.S.); (S.T.); (J.G.)
| | - Jorge Gascon
- KAUST Catalysis Center, King Abdullah University of Science and Technology, Advanced Catalytic Materials (ACM), Thuwal 23955, Saudi Arabia; (A.R.); (T.S.); (S.T.); (J.G.)
| | - Javier Ruiz-Martínez
- KAUST Catalysis Center, King Abdullah University of Science and Technology, Catalysis, Nanomaterials, and Spectroscopy (CNS), Thuwal 23955, Saudi Arabia;
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Pignié MC, Shcherbakov V, Charpentier T, Moskura M, Carteret C, Denisov S, Mostafavi M, Thill A, Le Caër S. Confined water radiolysis in aluminosilicate nanotubes: the importance of charge separation effects. NANOSCALE 2021; 13:3092-3105. [PMID: 33522536 DOI: 10.1039/d0nr08948f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Imogolite nanotubes are potentially promising co-photocatalysts because they are predicted to have curvature-induced, efficient electron-hole pair separation. This prediction has however not yet been experimentally proven. Here, we investigated the behavior upon irradiation of these inorganic nanotubes as a function of their water content to understand the fate of the generated electrons and holes. Two types of aluminosilicate nanotubes were studied: one was hydrophilic on its external and internal surfaces (IMO-OH) and the other had a hydrophobic internal cavity due to Si-CH3 bonds (IMO-CH3), with the external surface remaining hydrophilic. Picosecond pulse radiolysis experiments demonstrated that the electrons are efficiently driven outward. For imogolite samples with very few external water molecules (around 1% of the total mass), quasi-free electrons were formed. They were able to attach to a water molecule, generating a water radical anion, which ultimately led to dihydrogen. When more external water molecules were present, solvated electrons, precursors of dihydrogen, were formed. In contrast, holes moved towards the internal surface of the tubes. They mainly led to the formation of dihydrogen and of methane in irradiated IMO-CH3. The attachment of the quasi-free electron to water was a very efficient process and accounted for the high dihydrogen production at low relative humidity values. When the water content increased, electron solvation dominated over attachment to water molecules. Electron solvation led to dihydrogen production, albeit to a lesser extent than quasi-free electrons. Our experiments demonstrated the spontaneous curvature-induced charge separation in these inorganic nanotubes, making them very interesting potential co-photocatalysts.
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Affiliation(s)
- Marie-Claire Pignié
- NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
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11
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Huang X, Li J, Su X, Fang K, Wang Z, Liu L, Wang H, Yang C, Wang X. Remarkable damage in talc caused by electron beam irradiation with a dose of up to 1000 kGy: lattice shrinkage in the Z- and Y-axis and corresponding intrinsic microstructural transformation process speculation. RSC Adv 2021; 11:21870-21884. [PMID: 35478784 PMCID: PMC9034090 DOI: 10.1039/d1ra04012j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 05/31/2021] [Indexed: 11/21/2022] Open
Abstract
To reduce the polluted areas caused by the migration of radioactive or toxic matter, a clear understanding of soil matrix stability, especially the lattice, is essential under irradiation conditions like those of β-ray irradiation. In reality, the matrix of soil or clay is silicate, with talc being one of the most simple species with a similar structure to that matter, exhibiting “2 : 1” stacking and a complete crystal. Therefore, in this work, it was irradiated by an electron beam in air with dose up to 1000 kGy. Then, variations in lattice and the intrinsic microstructural transformation process, especially in terms of defect formation and transformation, were explored. The main results show that irradiation led to talc lattice plane shrinkage and amorphization. Shrinkage and amorphization levels in the Z-axis were more serious than those in the Y-axis. For a 1000 kGy-irradiated sample, the shrinkage level of the (002) lattice plane was close to 2% near 0.2 Å and that of (020) was close to 1.3% near 0.06 Å. Variation in the (002) lattice plane was more obvious than that of (020). The main mechanisms involve the cleavage of tetrahedral Si–O and linkage of tetrahedra and octahedra. Tetrahedral Si–O cleavage was visible, leading to serious amorphization. Nevertheless, lattice plane shrinkage, especially in the Z-axis, was mainly caused by linkage cleavage in this direction. In addition to linkage cleavage, dehydroxylation and H2O volatilization occurred, coupled with H2O radiolysis. Nevertheless, those factors are secondary to lattice variation. Upon irradiation, tetrahedral Si–O and the links of tetrahedron and octahedron sheets are cleaved, leading to shrinkage and amorphization. That in the Z-axis is more pronounced than in the Y-axis.![]()
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Affiliation(s)
- Xiaojun Huang
- School of Textile Science and Engineering
- Wuhan Textile University
- Wuhan 430200
- China
| | - Jiayan Li
- School of Textile Science and Engineering
- Wuhan Textile University
- Wuhan 430200
- China
| | - Xiaoya Su
- School of Textile Science and Engineering
- Wuhan Textile University
- Wuhan 430200
- China
| | - Ke Fang
- School of Textile Science and Engineering
- Wuhan Textile University
- Wuhan 430200
- China
| | - Zishuang Wang
- School of Textile Science and Engineering
- Wuhan Textile University
- Wuhan 430200
- China
| | - Lin Liu
- School of Textile Science and Engineering
- Wuhan Textile University
- Wuhan 430200
- China
| | - Honglong Wang
- School of Textile Science and Engineering
- Wuhan Textile University
- Wuhan 430200
- China
| | - Chenguang Yang
- School of Materials Science and Engineering
- Wuhan Textile University
- Wuhan 430200
- China
| | - Xiaoguang Wang
- School of Textile Science and Engineering
- Wuhan Textile University
- Wuhan 430200
- China
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Gulen B, Demircivi P. Adsorption properties of flouroquinolone type antibiotic ciprofloxacin into 2:1 dioctahedral clay structure: Box-Behnken experimental design. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127659] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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13
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Gulen B, Bugdayci M, Turan A, Demircivi P. Determination of adsorption characteristics of monolayer titanium carbide with fluoroquinolone pollutants in aqueous solution. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.112643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Ghandi K, Landry C, Du T, Lainé M, Saul A, Le Caër S. Influence of confinement on free radical chemistry in layered nanostructures. Sci Rep 2019; 9:17165. [PMID: 31748626 PMCID: PMC6868163 DOI: 10.1038/s41598-019-52662-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/18/2019] [Indexed: 11/08/2022] Open
Abstract
The purpose of the present work was to study how chemical reactions and the electronic structure of atoms are affected by confinement at the sub-nanometer scale. To reach this goal, we studied the H atom in talc, a layered clay mineral. Talc is a highly 2D-confining material with the width of its interlayer space close to angstrom. We investigated talc with a particle accelerator-based spectroscopic method that uses elementary particles. This technique generates an exotic atom, muonium (Mu), which can be considered as an isotope of the H atom. Moreover, the technique allows us to probe a single atom (H atom) at any time and explore the effects of the layered clay on a single ion (proton) or atom. The cation/electron recombination happens in two time windows: one faster than a nanosecond and the other one at longer than microseconds. This result suggests that two types of electron transfer processes take place in these clay minerals. Calculations demonstrated that the interlayer space acts as a catalytic surface and is the primary location of cation/electron recombination in talc. Moreover, the studies of the temperature dependence of Mu decay rates, due to the formation of the surrogate of H2, is suggestive of an "H2" formation reaction that is thermally activated above 25 K, but governed by quantum diffusion below 25 K. The experimental and computational studies of the hyperfine coupling constant of Mu suggest that it is formed in the interlayer space of talc and that its electronic structure is extremely changed due to confinement. All these results imply that the chemistry could be strongly affected by confinement in the interlayer space of clays.
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Affiliation(s)
- Khashayar Ghandi
- University of Guelph, Department of chemistry, Guelph, ON, N1G 2W1, Canada.
| | - Cody Landry
- University of Guelph, Department of chemistry, Guelph, ON, N1G 2W1, Canada
| | - Tait Du
- Université de Sherbrooke, Faculté de médecine, Sherbrooke, QC, J1H 5N4, Canada
| | - Maxime Lainé
- LIONS, NIMBE, CEA, CNRS, Université Paris Saclay, CEA Saclay, F-91191, Gif-sur-Yvette, Cedex, France
| | - Andres Saul
- Aix-Marseille University, CINaM-CNRS UMR 7325 Campus de Luminy, F-13288, Marseille, Cedex 9, France
| | - Sophie Le Caër
- LIONS, NIMBE, CEA, CNRS, Université Paris Saclay, CEA Saclay, F-91191, Gif-sur-Yvette, Cedex, France
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15
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Influence of calcium to silica ratio on H2 gas production in calcium silicate hydrate. Radiat Phys Chem Oxf Engl 1993 2019. [DOI: 10.1016/j.radphyschem.2019.04.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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16
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Wang H, Sun Y, Chu J, Wang X, Zhang M. Intensive study on structure transformation of muscovite single crystal under high-dose γ-ray irradiation and mechanism speculation. ROYAL SOCIETY OPEN SCIENCE 2019; 6:190594. [PMID: 31417756 PMCID: PMC6689601 DOI: 10.1098/rsos.190594] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 06/12/2019] [Indexed: 05/10/2023]
Abstract
Intensive study on structure transformation of muscovite single crystal under high-dose γ-ray irradiation is essential for its use in irradiation detection and also beneficial for mechanism cognition on defect formation within a matrix of clay used in the disposal of high-level radioactive waste (HLRW). In this work, muscovite single crystal was irradiated with Co-60 γ ray in air at a dose rate of 54 Gy min-1 with doses of 0-1000 kGy. Then, structure transformation and mechanism were explored by Raman spectrum, Fourier-transform infrared spectrum, X-ray diffraction, thermogravimetric analysis, CA, scanning electron microscope and atomic force microscopy. The main results show that variations in the chemical/crystalline structure are dose-dependent. Low-dose irradiation sufficiently destroyed the structure, removing Si-OH, thus declining hydrophilicity. With dose increase up to 100 kGy, CA increased from 20° to 40°. Except for hydrophilicity variation, shrink occurred in the (004) lattice plane which later recovered; the variation range at 500 kGy irradiation was 0.5% close to 0.02 Å. The main mechanisms involved were framework break and H2O radiolysis. Framework break results in Si-OH removal and H2O radiolysis results in extra OH introduction. The extra introduced OH probably results in Si-OH bond regeneration, lattice plane shrink and recovered surface hydrophilicity. The importance of framework break and H2O radiolysis on structure transformation is dose-dependence. At low doses, framework break seems more important while at high doses H2O radiolysis is important. Generally, variations in the chemical structure and surface property are nonlinear and less at high doses. This indicates using the chemical structure or surface property variation to describe irradiation is correct at low doses but not at high doses. This finding is meaningful for realizing whether muscovite is suitable for detecting high-dose irradiation or not, and mechanism exploration is efficient for identifying the procedure for defect formation within the matrix of clay used in disposal HLRW in practice.
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Affiliation(s)
| | | | | | | | - Ming Zhang
- Authors for correspondence: Ming Zhang e-mail:
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Wang H, Sun Y, Chu J, Wang X, Zhang M. Intensive evaluation of radiation stability of phlogopite single crystals under high doses of γ-ray irradiation. RSC Adv 2019; 9:6199-6210. [PMID: 35517284 PMCID: PMC9060914 DOI: 10.1039/c8ra08565j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 02/06/2019] [Indexed: 11/25/2022] Open
Abstract
The evaluation of radiation stability of clay is important for the disposal of high-level radioactive waste (HLRW). In this study, phlogopite single crystals were irradiated by Co-60 γ-rays in air at a dose rate of 3.254 kGy h−1 with doses up to 1000 kGy. Subsequently, the radiation stability and mechanism of radiation damage were explored by RS, FT-ATR, XRD, TGA, CA, and SEM techniques. In general, phlogopite single crystals show worthwhile radiation resistance toward their chemical structure but poor radiation stability toward their crystalline structure. Upon irradiation, their chemical structure changed slightly, while their crystalline structure varied obviously. For the 1000 kGy-irradiated sample, the interlayer space d of the (001) lattice plane increased by more than 1% with a value close to 0.13 Å, showing expansion. This could be mainly ascribed to H2O radiolysis and framework breakage: the former seems more important. These variations had a considerable impact on surface hydrophilicity, while they had marginal impacts on thermal stability and morphology: the effect on surface hydrophilicity is dose-dependent. A lower dose of irradiation sufficiently reduced the hydrophilicity, while a higher dose recovered the hydrophilicity. For instance, the CA increased from 14° to 28° with dose increases from 0 kGy to 200 kGy and then decreased to approximately 20° as the dose continued to increase to 1000 kGy. In general, the crystalline structure is more sensitive toward γ-ray irradiation and phlogopites could be regarded as poorly radiation-resistant. In this procedure, H2O radiolysis occupies a crucial role and seems to be the dominant factor. This finding is meaningful to evaluate the radiation stability of clay matrixes and to understand the microscopic property variations in clays used in practice when they are under irradiation. Upon irradiation, the framework underwent breakage, H2O underwent radiolysis, and the radiolysis products reacted with the framework, expanding the lattice plane.![]()
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Affiliation(s)
- Honglong Wang
- Institute of Materials, China Academy of Engineering Physics Jiangyou 621908 China
| | - Yaping Sun
- Institute of Materials, China Academy of Engineering Physics Jiangyou 621908 China
| | - Jian Chu
- Institute of Materials, China Academy of Engineering Physics Jiangyou 621908 China
| | - Xu Wang
- Institute of Materials, China Academy of Engineering Physics Jiangyou 621908 China
| | - Ming Zhang
- Institute of Materials, China Academy of Engineering Physics Jiangyou 621908 China
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Butnaru E, Stoleru E, Brebu MA, Darie-Nita RN, Bargan A, Vasile C. Chitosan-Based Bionanocomposite Films Prepared by Emulsion Technique for Food Preservation. MATERIALS 2019; 12:ma12030373. [PMID: 30691000 PMCID: PMC6384585 DOI: 10.3390/ma12030373] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/21/2019] [Accepted: 01/22/2019] [Indexed: 12/04/2022]
Abstract
Biopolymer nanocomposite films were prepared by casting film-forming emulsions based on chitosan/Tween 80/rosehip seed oil and dispersed montmorillonite nanoclay C30B. The effect of composition on structural, morphological characteristics and, mechanical, barrier, antimicrobial and antioxidant properties was studied. The presence of rosehip seed oil in chitosan films led to the formation of flexible films with improved mechanical, gas and water vapour barrier properties and antioxidant activity. The in vitro antibacterial tests against Escherichia coli, Salmonella typhymurium, and Bacillus cereus showed that the chitosan/rosehip seed oil/montmorillonite nanoclay composites effectively inhibited all the three microorganisms.
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Affiliation(s)
- Elena Butnaru
- Physical Chemistry of Polymers Department, "Petru Poni" Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, RO 700487 Iasi, Romania.
| | - Elena Stoleru
- Physical Chemistry of Polymers Department, "Petru Poni" Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, RO 700487 Iasi, Romania.
| | - Mihai Adrian Brebu
- Physical Chemistry of Polymers Department, "Petru Poni" Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, RO 700487 Iasi, Romania.
| | - Raluca Nicoleta Darie-Nita
- Physical Chemistry of Polymers Department, "Petru Poni" Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, RO 700487 Iasi, Romania.
| | - Alexandra Bargan
- Physical Chemistry of Polymers Department, "Petru Poni" Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, RO 700487 Iasi, Romania.
| | - Cornelia Vasile
- Physical Chemistry of Polymers Department, "Petru Poni" Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, RO 700487 Iasi, Romania.
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Abstract
Abstract
Smectite-rich natural clay is being evaluated as the backfill and buffer material in the Indian repository program for the nuclear high level waste disposal. In the natural clay, montmorillonite is one of the major mineral component governing the sorption behavior of various radionuclides. In the present work, influence of sulfate anion on sorption of Eu(III) by Na-montmorillonite has been investigated. The effect of pH and sulfate concentration on Eu(III) sorption by Na-montmorillonite was used to understand the mechanism of sorption process. The Eu(III) sorption by clay at varying pH was virtually pH independent at lower pH (<4), with ion exchange as the dominant mode for Eu(III) sorption. In the pH region of 4–6.5, sharp increase in sorption indicates surface complexation as predominant mechanism. At pH>6.5, the sorption attained a constant value. To deduce the mechanism of sorption of Eu(III) on Na-montmorillonite surface in presence of sulfate, ATR-FTIR spectroscopic investigations has been carried out which indicate the presence of sulfate bearing species on Na-montmorillonite surface. Using spectroscopic findings as a guide, the surface complexation modeling, in absence and presence of sulfate, was successfully carried out.
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Bouniol P, Guillot W, Dauvois V, Dridi W, Le Caër S. Original behavior of pore water radiolysis in cement-based materials containing sulfide: Coupling between experiments and simulations. Radiat Phys Chem Oxf Engl 1993 2018. [DOI: 10.1016/j.radphyschem.2018.04.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Soft X-ray Heterogeneous Radiolysis of Pyridine in the Presence of Hydrated Strontium-Hydroxyhectorite and its Monitoring by Near-Ambient Pressure Photoelectron Spectroscopy. Sci Rep 2018; 8:6164. [PMID: 29670155 PMCID: PMC5906652 DOI: 10.1038/s41598-018-24329-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 03/22/2018] [Indexed: 11/15/2022] Open
Abstract
The heterogeneous radiolysis of organic molecules in clays is a matter of considerable interest in astrochemistry and environmental sciences. However, little is known about the effects of highly ionizing soft X-rays. By combining monochromatized synchrotron source irradiation with in situ Near Ambient Pressure X-ray Photoelectron Spectroscopy (in the mbar range), and using the synoptic view encompassing both the gas and condensed phases, we found the water and pyridine pressure conditions under which pyridine is decomposed in the presence of synthetic Sr2+-hydroxyhectorite. The formation of a pyridine/water/Sr2+ complex, detected from the Sr 3d and N 1s core-level binding energies, likely presents a favorable situation for the radiolytic breaking of the O-H bond of water molecules adsorbed in the clay and the subsequent decomposition of the molecule. However, decomposition stops when the pyridine pressure exceeds a critical value. This observation can be related to a change in the nature of the active radical species with the pyridine loading. This highlights the fact that the destruction of the molecule is not entirely determined by the properties of the host material, but also by the inserted organic species. The physical and chemical causes of the present observations are discussed.
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γ-radiation induced corrosion of copper in bentonite-water systems under anaerobic conditions. Radiat Phys Chem Oxf Engl 1993 2018. [DOI: 10.1016/j.radphyschem.2017.11.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kumagai Y, Kimura A, Taguchi M, Watanabe M. Radiation-induced degradation of aqueous 2–chlorophenol assisted by zeolites. J Radioanal Nucl Chem 2018. [DOI: 10.1007/s10967-018-5762-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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