Molecular dynamics study of confined liquid film viscosity in constant-pressure and constant-distance systems
Viscosity changes in confined liquids have been explored using experimental techniques including surface force apparatus (SFA) and fiber wobbling method (FWM), revealing different magnitudes of viscosity increment as the gap between confining solid surfaces decreases. To address this disparity, we p...
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| Format: | Article |
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Elsevier B.V.
2024
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| _version_ | 1824452059963850752 |
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| author | Chen, Xingyu Zhang, Hedong Yokoyama, Hayata Chong, William Woei Fong Fukuzawa, Kenji Itoh, Shintaro |
| author_facet | Chen, Xingyu Zhang, Hedong Yokoyama, Hayata Chong, William Woei Fong Fukuzawa, Kenji Itoh, Shintaro |
| author_sort | Chen, Xingyu |
| collection | ePrints |
| description | Viscosity changes in confined liquids have been explored using experimental techniques including surface force apparatus (SFA) and fiber wobbling method (FWM), revealing different magnitudes of viscosity increment as the gap between confining solid surfaces decreases. To address this disparity, we performed molecular dynamics simulations to gain insights into the mechanisms of viscosity changes in confined liquid UV-curable resin films used in nanoimprint lithography. Solid surfaces were fixed to maintain a constant pressure or distance, resembling SFA and FWM, respectively. Consistent with experimental results, our simulations confirmed that the viscosity increases with decreasing solid–solid gaps, notably, more pronounced in the constant-distance system than in the constant-pressure one. However, the two systems exhibited no distinct difference in the liquid molecular distribution. By introducing a new concept of free volume change rate, we conducted an in-depth analysis of liquid molecular motion, revealing more active motion in the constant-pressure system, particularly in the central region between the solid surfaces. This motion correlated positively with atomic vibrations of the confining surfaces. Our findings emphasize that different confinement conditions (constant pressure or constant distance) distinctly alter the liquid molecular motion and thus the magnitude of viscosity, underscoring the necessity for precise characterization of the rheological properties of confined UV-curable resins. |
| first_indexed | 2025-02-19T02:44:31Z |
| format | Article |
| id | utm.eprints-108890 |
| institution | Universiti Teknologi Malaysia - ePrints |
| last_indexed | 2025-02-19T02:44:31Z |
| publishDate | 2024 |
| publisher | Elsevier B.V. |
| record_format | dspace |
| spelling | utm.eprints-1088902024-12-11T09:45:10Z http://eprints.utm.my/108890/ Molecular dynamics study of confined liquid film viscosity in constant-pressure and constant-distance systems Chen, Xingyu Zhang, Hedong Yokoyama, Hayata Chong, William Woei Fong Fukuzawa, Kenji Itoh, Shintaro TJ Mechanical engineering and machinery Viscosity changes in confined liquids have been explored using experimental techniques including surface force apparatus (SFA) and fiber wobbling method (FWM), revealing different magnitudes of viscosity increment as the gap between confining solid surfaces decreases. To address this disparity, we performed molecular dynamics simulations to gain insights into the mechanisms of viscosity changes in confined liquid UV-curable resin films used in nanoimprint lithography. Solid surfaces were fixed to maintain a constant pressure or distance, resembling SFA and FWM, respectively. Consistent with experimental results, our simulations confirmed that the viscosity increases with decreasing solid–solid gaps, notably, more pronounced in the constant-distance system than in the constant-pressure one. However, the two systems exhibited no distinct difference in the liquid molecular distribution. By introducing a new concept of free volume change rate, we conducted an in-depth analysis of liquid molecular motion, revealing more active motion in the constant-pressure system, particularly in the central region between the solid surfaces. This motion correlated positively with atomic vibrations of the confining surfaces. Our findings emphasize that different confinement conditions (constant pressure or constant distance) distinctly alter the liquid molecular motion and thus the magnitude of viscosity, underscoring the necessity for precise characterization of the rheological properties of confined UV-curable resins. Elsevier B.V. 2024-06-15 Article PeerReviewed Chen, Xingyu and Zhang, Hedong and Yokoyama, Hayata and Chong, William Woei Fong and Fukuzawa, Kenji and Itoh, Shintaro (2024) Molecular dynamics study of confined liquid film viscosity in constant-pressure and constant-distance systems. Journal of Molecular Liquids, 404 (NA). NA. ISSN 0167-7322 http://dx.doi.org/10.1016/j.molliq.2024.124955 DOI:10.1016/j.molliq.2024.124955 |
| spellingShingle | TJ Mechanical engineering and machinery Chen, Xingyu Zhang, Hedong Yokoyama, Hayata Chong, William Woei Fong Fukuzawa, Kenji Itoh, Shintaro Molecular dynamics study of confined liquid film viscosity in constant-pressure and constant-distance systems |
| title | Molecular dynamics study of confined liquid film viscosity in constant-pressure and constant-distance systems |
| title_full | Molecular dynamics study of confined liquid film viscosity in constant-pressure and constant-distance systems |
| title_fullStr | Molecular dynamics study of confined liquid film viscosity in constant-pressure and constant-distance systems |
| title_full_unstemmed | Molecular dynamics study of confined liquid film viscosity in constant-pressure and constant-distance systems |
| title_short | Molecular dynamics study of confined liquid film viscosity in constant-pressure and constant-distance systems |
| title_sort | molecular dynamics study of confined liquid film viscosity in constant pressure and constant distance systems |
| topic | TJ Mechanical engineering and machinery |
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