Back to Search
Start Over
Molecularly Capped Omniphobic Polydimethylsiloxane Brushes with Ultra-Fast Contact Line Dynamics.
- Source :
-
Small (Weinheim an der Bergstrasse, Germany) [Small] 2023 Sep; Vol. 19 (38), pp. e2301142. Date of Electronic Publication: 2023 May 18. - Publication Year :
- 2023
-
Abstract
- Droplet friction is common and significant in any field where liquids interact with solid surfaces. This study explores the molecular capping of surface-tethered, liquid-like polydimethylsiloxane (PDMS) brushes and its substantial effect on droplet friction and liquid repellency. By exchanging polymer chain terminal silanol groups for methyls using a single-step vapor phase reaction, the contact line relaxation time is decreased by three orders of magnitude-from seconds to milliseconds. This leads to a substantial reduction in the static and kinetic friction of both high- and low-surface tension fluids. Vertical droplet oscillatory imaging confirms the ultra-fast contact line dynamics of capped PDMS brushes, which is corroborated by live contact angle monitoring during fluid flow. This study proposes that truly omniphobic surfaces should not only have very small contact angle hysteresis, but their contact line relaxation time should be significantly shorter than the timescale of their useful application, i.e., a Deborah number less than unity. Capped PDMS brushes that meet these criteria demonstrate complete suppression of the coffee ring effect, excellent anti-fouling behavior, directional droplet transport, increased water harvesting performance, and transparency retention following the evaporation of non-Newtonian fluids.<br /> (© 2023 The Authors. Small published by Wiley-VCH GmbH.)
Details
- Language :
- English
- ISSN :
- 1613-6829
- Volume :
- 19
- Issue :
- 38
- Database :
- MEDLINE
- Journal :
- Small (Weinheim an der Bergstrasse, Germany)
- Publication Type :
- Academic Journal
- Accession number :
- 37202658
- Full Text :
- https://doi.org/10.1002/smll.202301142