Droplet slipperiness despite surface heterogeneity at molecular scale
No Thumbnail Available
Access rights
openAccess
publishedVersion
URL
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
Date
2024-04
Major/Subject
Mcode
Degree programme
Language
en
Pages
8
Series
Nature Chemistry, Volume 16, issue 4, pp. 506–513
Abstract
Friction determines whether liquid droplets slide off a solid surface or stick to it. Surface heterogeneity is generally acknowledged as the major cause of increased contact angle hysteresis and contact line friction of droplets. Here we challenge this long-standing premise for chemical heterogeneity at the molecular length scale. By tuning the coverage of self-assembled monolayers (SAMs), water contact angles change gradually from about 10° to 110° yet contact angle hysteresis and contact line friction are low for the low-coverage hydrophilic SAMs as well as high-coverage hydrophobic SAMs. Their slipperiness is not expected based on the substantial chemical heterogeneity of the SAMs featuring uncoated areas of the substrate well beyond the size of a water molecule as probed by metal reactants. According to molecular dynamics simulations, the low friction of both low- and high-coverage SAMs originates from the mobility of interfacial water molecules. These findings reveal a yet unknown and counterintuitive mechanism for slipperiness, opening new avenues for enhancing the mobility of droplets.Description
| openaire: EC/H2020/725513/EU//SuperRepel
Keywords
Other note
Citation
Lepikko, S, Morais Jaques, Y, Junaid, M, Backholm, M, Lahtinen, J, Julin, J, Jokinen, V, Sajavaara, T, Sammalkorpi, M, Foster, A & Ras, R 2024, ' Droplet slipperiness despite surface heterogeneity at molecular scale ', Nature Chemistry, vol. 16, no. 4, pp. 506–513 . https://doi.org/10.1038/s41557-023-01346-3