Structure and Diffusion of Ionic PDMS Melts
Ionic polymers exhibit mechanical properties that can be widely tuned upon selectively charging them. However, the correlated structural and dynamical properties underlying the microscopic mechanism remain largely unexplored. Here, we investigate, for the first time, the structure and diffusion of r...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-07-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/14/15/3070 |
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| author | Argyrios V. Karatrantos Jettawat Khantaveramongkol Martin Kröger |
| author_facet | Argyrios V. Karatrantos Jettawat Khantaveramongkol Martin Kröger |
| author_sort | Argyrios V. Karatrantos |
| collection | DOAJ |
| description | Ionic polymers exhibit mechanical properties that can be widely tuned upon selectively charging them. However, the correlated structural and dynamical properties underlying the microscopic mechanism remain largely unexplored. Here, we investigate, for the first time, the structure and diffusion of randomly and end-functionalized ionic poly(dimethylsiloxane) (PDMS) melts with negatively charged bromide counterions, by means of atomistic molecular dynamics using a united atom model. In particular, we find that the density of the ionic PDMS melts exceeds the one of their neutral counterpart and increases as the charge density increases. The counterions are condensed to the cationic part of end-functionalized cationic PDMS chains, especially for the higher molecular weights, leading to a slow diffusion inside the melt; the counterions are also correlated more strongly to each other for the end-functionalized PDMS. Temperature has a weak effect on the counterion structure and leads to an Arrhenius type of behavior for the counterion diffusion coefficient. In addition, the charge density of PDMS chains enhances the diffusion of counterions especially at higher temperatures, but hinders PDMS chain dynamics. Neutral PDMS chains are shown to exhibit faster dynamics (diffusion) than ionic PDMS chains. These findings contribute to the theoretical description of the correlations between structure and dynamical properties of ion-containing polymers. |
| first_indexed | 2024-03-09T10:05:59Z |
| format | Article |
| id | doaj.art-f1c57c1589f94ce59a7da8739db026cb |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-09T10:05:59Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-f1c57c1589f94ce59a7da8739db026cb2023-12-01T23:06:59ZengMDPI AGPolymers2073-43602022-07-011415307010.3390/polym14153070Structure and Diffusion of Ionic PDMS MeltsArgyrios V. Karatrantos0Jettawat Khantaveramongkol1Martin Kröger2Materials Research and Technology, Luxembourg Institute of Science and Technology, 5, Avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette, LuxembourgMaterials Research and Technology, Luxembourg Institute of Science and Technology, 5, Avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette, LuxembourgPolymer Physics, Department of Materials, ETH Zurich, Leopold-Ruzicka-Weg 4, CH-8093 Zurich, SwitzerlandIonic polymers exhibit mechanical properties that can be widely tuned upon selectively charging them. However, the correlated structural and dynamical properties underlying the microscopic mechanism remain largely unexplored. Here, we investigate, for the first time, the structure and diffusion of randomly and end-functionalized ionic poly(dimethylsiloxane) (PDMS) melts with negatively charged bromide counterions, by means of atomistic molecular dynamics using a united atom model. In particular, we find that the density of the ionic PDMS melts exceeds the one of their neutral counterpart and increases as the charge density increases. The counterions are condensed to the cationic part of end-functionalized cationic PDMS chains, especially for the higher molecular weights, leading to a slow diffusion inside the melt; the counterions are also correlated more strongly to each other for the end-functionalized PDMS. Temperature has a weak effect on the counterion structure and leads to an Arrhenius type of behavior for the counterion diffusion coefficient. In addition, the charge density of PDMS chains enhances the diffusion of counterions especially at higher temperatures, but hinders PDMS chain dynamics. Neutral PDMS chains are shown to exhibit faster dynamics (diffusion) than ionic PDMS chains. These findings contribute to the theoretical description of the correlations between structure and dynamical properties of ion-containing polymers.https://www.mdpi.com/2073-4360/14/15/3070polymer electrolytesionomersionic group distributiongrafted polymerscounterion condensationion transport |
| spellingShingle | Argyrios V. Karatrantos Jettawat Khantaveramongkol Martin Kröger Structure and Diffusion of Ionic PDMS Melts Polymers polymer electrolytes ionomers ionic group distribution grafted polymers counterion condensation ion transport |
| title | Structure and Diffusion of Ionic PDMS Melts |
| title_full | Structure and Diffusion of Ionic PDMS Melts |
| title_fullStr | Structure and Diffusion of Ionic PDMS Melts |
| title_full_unstemmed | Structure and Diffusion of Ionic PDMS Melts |
| title_short | Structure and Diffusion of Ionic PDMS Melts |
| title_sort | structure and diffusion of ionic pdms melts |
| topic | polymer electrolytes ionomers ionic group distribution grafted polymers counterion condensation ion transport |
| url | https://www.mdpi.com/2073-4360/14/15/3070 |
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