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Das A, Schleinitz J, Karmazin L, Vincent B, Le Breton N, Rogez G, Guenet A, Choua S, Grimaud L, Desage‐El Murr M. A Single Bioinspired Hexameric Nickel Catechol–Alloxazine Catalyst Combines Metal and Radical Mechanisms for Alkene Hydrosilylation. Chemistry 2022; 28:e202200596. [DOI: 10.1002/chem.202200596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Agnideep Das
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Jules Schleinitz
- Laboratoire des biomolécules LBM, Chemistry Department École normale supérieure PSL University Sorbonne Université, CNRS 75005 Paris France
| | - Lydia Karmazin
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Bruno Vincent
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Nolwenn Le Breton
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Guillaume Rogez
- Institut de Physique et Chimie des Matériaux de Strasbourg Université de Strasbourg, CNRS, UMR 7504 67000 Strasbourg France
| | - Aurélie Guenet
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Sylvie Choua
- Université de Strasbourg Institut de Chimie, CNRS UMR7177 67000 Strasbourg France
| | - Laurence Grimaud
- Laboratoire des biomolécules LBM, Chemistry Department École normale supérieure PSL University Sorbonne Université, CNRS 75005 Paris France
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Maiti A, Small W, Kroonblawd MP, Lewicki JP, Goldman N, Wilson TS, Saab AP. Constitutive Model of Radiation Aging Effects in Filled Silicone Elastomers under Strain. J Phys Chem B 2021; 125:10047-10057. [PMID: 34450004 DOI: 10.1021/acs.jpcb.1c04958] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Filled silicone elastomers, an essential component in many technological applications, are often subjected to controlled or unintended radiation for a variety of reasons. Radiation exposure can lead to permanent mechanical and structural changes in the material, which is manifested as altered mechanical response, and in some cases, a permanent set. For unfilled elastomers, network theories developed and refined over decades can explain these effects in terms of chain-scission and cross-link formation and a hypothesis involving independent networks formed at different strain levels of the material. Here, we expose a filled silicone rubber to gamma radiation while being under finite elongational strain and show that the observed mechanical and structural changes can be quantitatively modeled within the same theoretical framework developed for unfilled elastomers as long as nuances associated with the Mullins effect are accounted for in a consistent manner. In this work, we employ Ogden's incompressible hyperelastic model within the framework of Tobolsky's two-network scheme to describe the observed permanent set and mechanical modulus changes as a function of radiation dosage. In the process, we conclude that gamma radiation induces both direct cross-linking at chain crossings (H-links) and main-chain-scission followed by cross-linking (Y-links). We provide an estimate of the ratio of chain-scission to cross-linking rates, which is in reasonable agreement with previous experimental estimate from Charlesby-Pinner analysis. We use density functional theory (DFT)-based quantum mechanical calculations to explore the stability of -Si and -SiO radicals that form upon a radiation-induced chain-scission event, which sheds light on the relative rates of Y-linking and H-linking processes.
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Affiliation(s)
- A Maiti
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - W Small
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - M P Kroonblawd
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - J P Lewicki
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - N Goldman
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - T S Wilson
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - A P Saab
- Lawrence Livermore National Laboratory, Livermore, California 94550, United States
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Belh SJ, Ghosh G, Greer A. Surface-Radical Mobility Test by Self-Sorted Recombination: Symmetrical Product upon Recombination (SPR). J Phys Chem B 2021; 125:4212-4220. [PMID: 33856798 DOI: 10.1021/acs.jpcb.1c01099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe here a study of the mobility of the alkoxy radical on a surface by detection of its recombination product. A novel method called symmetrical product recombination (SRP) uses an unsymmetrical peroxide that upon sensitized homolysis recombines to a symmetrical product [R'OOR → R'O•↑ + •OR → ROOR]. This allows for self-sorting of the radical to enhance the recombination path to a symmetrical product, which has been used to deduce surface migratory aptitude. SPR also provides a new opportunity for mechanistic studies of interfacial radicals, including monitoring competition between radical recombination versus surface hydrogen abstraction. This is an approach that might work for other surface-borne radicals on natural and artificial particles.
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Affiliation(s)
- Sarah J Belh
- Department of Chemistry, Brooklyn College, 2900 Bedford Avenue, Brooklyn, New York 11210, United States.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
| | - Goutam Ghosh
- Department of Chemistry, Brooklyn College, 2900 Bedford Avenue, Brooklyn, New York 11210, United States.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
| | - Alexander Greer
- Department of Chemistry, Brooklyn College, 2900 Bedford Avenue, Brooklyn, New York 11210, United States.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
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Xu M, Xue H, Tin WY, Wang H, Yong Z, Wang Q. Synergistic Effect by Polyethylene Glycol as Interfacial Modifier in Silane-Modified Silica-Reinforced Composites. Polymers (Basel) 2021; 13:788. [PMID: 33806605 PMCID: PMC7961832 DOI: 10.3390/polym13050788] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 11/30/2022] Open
Abstract
The viscoelastic behavior and reinforcement mechanism of polyethylene glycol (PEG) as an interfacial modifier in green tire tread composites were investigated in this study. The results show a clear positive effect on overall performance, and it significantly improved all the parameters of the "magic triangle" properties, the abrasion resistance, wet grip and ice traction, as well as the tire rolling resistance, simultaneously. For the preparation of the compounds, two mixing steps were used, as PEG 4000 was added on the second stage in order to avoid the competing reaction between silica/PEG and silanization. Fourier transform infrared spectroscopy (FTIR) confirmed that PEG could cover the silanol groups on the silica surface, resulting in the shortening of cure times and facilitating an increase of productivity. At low content of PEG, the strength was enhanced by the improvement of silica dispersion and the slippage of PEG chains, which are chemically and physically adsorbed on silica surface, but the use of excess PEG uncombined with silica in the compound, i.e., 5 phr, increases the possibility to shield the disulfide bonds of bis(3-(triethoxysilyl)-propyl) tetrasulfide (TESPT), and, thus, the properties were deteriorated. A constrained polymer model was proposed to explain the constrained chains of PEG in the silica-loaded composites on the basis of these results. An optimum PEG content is necessary for moderately strong matrix-filler interaction and, hence, for the enhancement in the mechanical properties.
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Affiliation(s)
| | | | | | | | | | - Qingfu Wang
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, School of Polymer Science and Engineering, Qingdao University of Science & Technology, Qingdao 266042, China; (M.X.); (H.X.); (W.Y.T.); (H.W.); (Z.Y.)
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Yao J, Yu Y, Qu R, Chen J, Huo Z, Zhu F, Wang Z. Fe-Activated Peroxymonosulfate Enhances the Degradation of Dibutyl Phthalate on Ground Quartz Sand. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:9052-9061. [PMID: 32539364 DOI: 10.1021/acs.est.0c00793] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Soil contamination by organic compounds has received worldwide concern for decades. Here, we found that dibutyl phthalate (DBP) could be degraded on moist quartz sand (QS, crystal, a typical soil constituent) during stirring, and the removal rate reached 57.2 ± 3.1% after 8 h of reaction. The introduction of peroxymonosulfate (PMS) and zerovalent iron (Fe0) substantially improved the decomposition of DBP to 94.2 ± 1.6% in 8 h, suggesting they have great contributions. DBP decomposition was caused by multiple reactive species, such as surface silicon-based radicals (like ≡SiO•) and other reactive species like superoxide radical (O2•-), hydroxyl radical (•OH), and sulfate radical (SO4•-). In the QS/ultrapure water system, DBP was mainly attacked by O2•- or ≡SiO•, with the formation of hydrolysis products. In the iron@QS/PMS system, due to the activation of PMS by Fe0, SO4•- and •OH were produced while the latter led to DBP degradation, and thus hydroxyl substitution products of DBP were ubiquitous. DBP was hardly removed on amorphous supporters like silica gel, alumina, and red soil even with the presence of PMS and Fe0, indicating the indispensable role of surface radicals on crystals like QS. This work presents a new remediation technology for polluted soil, especially aquifer.
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Affiliation(s)
- Jiayi Yao
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, P. R. China
| | - Yao Yu
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, P. R. China
| | - Ruijuan Qu
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, P. R. China
| | - Jing Chen
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, P. R. China
| | - Zongli Huo
- Jiangsu Provincial Center for Disease Control and Prevention, No. 172 Jiangsu Road, Nanjing 210009, Jiangsu, P. R. China
| | - Feng Zhu
- Jiangsu Provincial Center for Disease Control and Prevention, No. 172 Jiangsu Road, Nanjing 210009, Jiangsu, P. R. China
| | - Zunyao Wang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, P. R. China
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Nauth AM, Schechtel E, Dören R, Tremel W, Opatz T. TiO2 Nanoparticles Functionalized with Non-innocent Ligands Allow Oxidative Photocyanation of Amines with Visible/Near-Infrared Photons. J Am Chem Soc 2018; 140:14169-14177. [DOI: 10.1021/jacs.8b07539] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Alexander M. Nauth
- Institut für Organische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
| | - Eugen Schechtel
- Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
| | - René Dören
- Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
| | - Wolfgang Tremel
- Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
| | - Till Opatz
- Institut für Organische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
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Sommer-Marquez A, Mansas C, Talha N, Rey C, Causse J. Reinforced silica monoliths functionalised with metal hexacyanoferrates for cesium decontamination: a combination of a one-pot procedure and skeleton calcination. RSC Adv 2016; 6:73475-73484. [DOI: 10.1039/c6ra16980e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023] Open
Abstract
Procedure describes the synthesis of silica monoliths functionalised with metal hexacyanoferrate (MHCF) using a high internal phase emulsion template. The materials exhibit excellent Cs ion sorption properties.
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Affiliation(s)
- A. Sommer-Marquez
- Institut de Chimie Séparative de Marcoule ICSM
- UMR 5257
- CNRS/CEA/UM/ENSCM
- 30207 Bagnols sur Cèze
- France
| | - C. Mansas
- Institut de Chimie Séparative de Marcoule ICSM
- UMR 5257
- CNRS/CEA/UM/ENSCM
- 30207 Bagnols sur Cèze
- France
| | - N. Talha
- Institut de Chimie Séparative de Marcoule ICSM
- UMR 5257
- CNRS/CEA/UM/ENSCM
- 30207 Bagnols sur Cèze
- France
| | - C. Rey
- Institut de Chimie Séparative de Marcoule ICSM
- UMR 5257
- CNRS/CEA/UM/ENSCM
- 30207 Bagnols sur Cèze
- France
| | - J. Causse
- Institut de Chimie Séparative de Marcoule ICSM
- UMR 5257
- CNRS/CEA/UM/ENSCM
- 30207 Bagnols sur Cèze
- France
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Ward AJ, Lesic RA, Proschogo N, Masters AF, Maschmeyer T. Strained surface siloxanes as a source of synthetically important radicals. RSC Adv 2015. [DOI: 10.1039/c5ra20399f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The calcination of pure amorphous silica at temperatures up to 850 °C results in the formation of strained siloxane rings which are capable of undergoing homolytic cleavage to generate radicals when in the presence of an appropriate substrate.
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Affiliation(s)
- Antony J. Ward
- Laboratory of Advanced Catalysis for Sustainability
- School of Chemistry
- The University of Sydney
- Australia
| | - Rebecca A. Lesic
- Laboratory of Advanced Catalysis for Sustainability
- School of Chemistry
- The University of Sydney
- Australia
| | - Nicholas Proschogo
- Mass Spectrometry Unit
- School of Chemistry F11
- The University of Sydney
- Australia
| | - Anthony F. Masters
- Laboratory of Advanced Catalysis for Sustainability
- School of Chemistry
- The University of Sydney
- Australia
| | - Thomas Maschmeyer
- Laboratory of Advanced Catalysis for Sustainability
- School of Chemistry
- The University of Sydney
- Australia
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Dondi D, Buttafava A, Zeffiro A, Palamini C, Lostritto A, Giannini L, Faucitano A. The mechanisms of the sulphur-only and catalytic vulcanization of polybutadiene: An EPR and DFT study. Eur Polym J 2015. [DOI: 10.1016/j.eurpolymj.2014.11.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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D'Acunzo F, Gentili P, Masci G, Ursini O. Towards controlled cationic polymer growth from inorganic oxide defects: Directing the mechanism of polystyrene grafting from γ-irradiated silica. POLYMER 2014. [DOI: 10.1016/j.polymer.2014.08.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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D'Acunzo F, Capitani D, Masci G, Cherubini C, Ursini O. Polymerization, grafting and adsorption in the presence of inorganic substrates: Thermal polymerization of styrene with untreated and γ-irradiated silica gel as a case study. POLYMER 2013. [DOI: 10.1016/j.polymer.2013.10.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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