Promoting rebound of impinging viscoelastic droplets on heated superhydrophobic surfaces
The rebound of impinging droplets is a defining characteristic of superhydrophobic surfaces; yet, such an intriguing interfacial phenomenon can be effectively suppressed by adding a tiny amount of flexible polymers to induce non-Newtonian viscoelastic properties. In this work, however, we demonstrat...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2020-01-01
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| Series: | New Journal of Physics |
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| Online Access: | https://doi.org/10.1088/1367-2630/abcacf |
| _version_ | 1827872903886012416 |
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| author | Bin Li Shiji Lin Yile Wang Quanzi Yuan Sang W Joo Longquan Chen |
| author_facet | Bin Li Shiji Lin Yile Wang Quanzi Yuan Sang W Joo Longquan Chen |
| author_sort | Bin Li |
| collection | DOAJ |
| description | The rebound of impinging droplets is a defining characteristic of superhydrophobic surfaces; yet, such an intriguing interfacial phenomenon can be effectively suppressed by adding a tiny amount of flexible polymers to induce non-Newtonian viscoelastic properties. In this work, however, we demonstrate the promoting effects of surface heating on the rebound of impinging viscoelastic droplets on superhydrophobic surfaces. The underlying mechanism for the promotion is that the local heat transfer at the liquid–solid interface causes the fast evaporation of the liquid and thus the breakup of the formed viscoelastic filaments, which hinder droplet recoiling. Therefore, the lower threshold velocity for rebound increases while the upper threshold velocity for rebound suppression decreases with increasing surface temperature, resulting in a wider regime for droplet rebound in the impact phase diagram. The surface heating effect on liquid–solid interactions also leads to a nontrivial dependence of the contact time on the impact velocity and a linear decrease of the restitution coefficient with the Weber number for diverse bouncing viscoelastic droplets, which can be rationalized by coupling the interfacial force and energy analyses. We envision that these findings would be useful in technological processes requiring control the retention of viscoelastic liquids on solid surfaces. |
| first_indexed | 2024-03-12T16:30:07Z |
| format | Article |
| id | doaj.art-0b25cd81f43a4d30955b145ca3229f44 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:30:07Z |
| publishDate | 2020-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-0b25cd81f43a4d30955b145ca3229f442023-08-08T15:30:10ZengIOP PublishingNew Journal of Physics1367-26302020-01-01221212300110.1088/1367-2630/abcacfPromoting rebound of impinging viscoelastic droplets on heated superhydrophobic surfacesBin Li0Shiji Lin1Yile Wang2Quanzi Yuan3Sang W Joo4https://orcid.org/0000-0001-9102-4224Longquan Chen5https://orcid.org/0000-0002-6785-5914School of Physics, University of Electronic Science and Technology of China , Chengdu 610054, People’s Republic of China; School of Mechanical Engineering, Yeungnam University , Gyeongsan 38541, Republic of KoreaSchool of Physics, University of Electronic Science and Technology of China , Chengdu 610054, People’s Republic of ChinaSchool of Physics, University of Electronic Science and Technology of China , Chengdu 610054, People’s Republic of ChinaState Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences , Beijing 100190, People’s Republic of China; School of Engineering Science, University of Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaSchool of Mechanical Engineering, Yeungnam University , Gyeongsan 38541, Republic of KoreaSchool of Physics, University of Electronic Science and Technology of China , Chengdu 610054, People’s Republic of ChinaThe rebound of impinging droplets is a defining characteristic of superhydrophobic surfaces; yet, such an intriguing interfacial phenomenon can be effectively suppressed by adding a tiny amount of flexible polymers to induce non-Newtonian viscoelastic properties. In this work, however, we demonstrate the promoting effects of surface heating on the rebound of impinging viscoelastic droplets on superhydrophobic surfaces. The underlying mechanism for the promotion is that the local heat transfer at the liquid–solid interface causes the fast evaporation of the liquid and thus the breakup of the formed viscoelastic filaments, which hinder droplet recoiling. Therefore, the lower threshold velocity for rebound increases while the upper threshold velocity for rebound suppression decreases with increasing surface temperature, resulting in a wider regime for droplet rebound in the impact phase diagram. The surface heating effect on liquid–solid interactions also leads to a nontrivial dependence of the contact time on the impact velocity and a linear decrease of the restitution coefficient with the Weber number for diverse bouncing viscoelastic droplets, which can be rationalized by coupling the interfacial force and energy analyses. We envision that these findings would be useful in technological processes requiring control the retention of viscoelastic liquids on solid surfaces.https://doi.org/10.1088/1367-2630/abcacfdroplet impactviscoelastic filamentssuperhydrophobic surfaceheat transfercontact timerestitution coefficient |
| spellingShingle | Bin Li Shiji Lin Yile Wang Quanzi Yuan Sang W Joo Longquan Chen Promoting rebound of impinging viscoelastic droplets on heated superhydrophobic surfaces New Journal of Physics droplet impact viscoelastic filaments superhydrophobic surface heat transfer contact time restitution coefficient |
| title | Promoting rebound of impinging viscoelastic droplets on heated superhydrophobic surfaces |
| title_full | Promoting rebound of impinging viscoelastic droplets on heated superhydrophobic surfaces |
| title_fullStr | Promoting rebound of impinging viscoelastic droplets on heated superhydrophobic surfaces |
| title_full_unstemmed | Promoting rebound of impinging viscoelastic droplets on heated superhydrophobic surfaces |
| title_short | Promoting rebound of impinging viscoelastic droplets on heated superhydrophobic surfaces |
| title_sort | promoting rebound of impinging viscoelastic droplets on heated superhydrophobic surfaces |
| topic | droplet impact viscoelastic filaments superhydrophobic surface heat transfer contact time restitution coefficient |
| url | https://doi.org/10.1088/1367-2630/abcacf |
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