Unraveling the hydrophobic interaction mechanisms of hydrocarbon and fluorinated surfaces

Lu Gong; Feiyi Wu; Wenshuai Yang; Charley Huang; Wenhui Li; Xiaogang Wang; Jianmei Wang; Tian Tang; Hongbo Zeng

doi:10.1016/j.jcis.2022.12.084

Unraveling the hydrophobic interaction mechanisms of hydrocarbon and fluorinated surfaces

J Colloid Interface Sci. 2023 Apr:635:273-283. doi: 10.1016/j.jcis.2022.12.084. Epub 2022 Dec 20.

Authors

Lu Gong¹, Feiyi Wu¹, Wenshuai Yang¹, Charley Huang¹, Wenhui Li¹, Xiaogang Wang², Jianmei Wang², Tian Tang³, Hongbo Zeng⁴

Affiliations

¹ Department of Chemical & Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
² Heavy Machinery Engineering Research Center of Education Ministry, Taiyuan University of Science and Technology, Taiyuan 030024, China.
³ Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
⁴ Department of Chemical & Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada. Electronic address: hongbo.zeng@ualberta.ca.

PMID: 36587579
DOI: 10.1016/j.jcis.2022.12.084

Abstract

Hypothesis: Numerous hydrocarbon and fluorine-based hydrophobic surfaces have been widely applied in various engineering and bioengineering fields. It is hypothesized that the hydrophobic interactions of hydrocarbon and fluorinated surfaces in aqueous media would show some differences.

Experiments: The hydrophobic interactions of hydrocarbon and fluorinated surfaces with air bubbles in aqueous solutions have been systematically and quantitatively measured using a bubble probe atomic force microscopy (AFM) technique. Ethanol was introduced to water for modulating the solution polarity. The experimental force profiles were analyzed using a theoretical model combining the Reynolds lubrication theory and augmented Young-Laplace equation by including disjoining pressure arisen from the Derjarguin-Landau-Verwey-Overbeek (DLVO) and non-DLVO interactions (i.e., hydrophobic interactions).

Findings: The experiment results show that the hydrophobic interactions were firstly weakened and then strengthened by increasing ethanol content in the aqueous media, mainly due to the variation in interfacial hydrogen bonding network. The fluorinated surface exhibited less sensitivity to ethanol than hydrocarbon surface, which is attributed to the presence of ordered interfacial water layer. Our work reveals the different hydrophobic effects of hydrocarbon and fluorinated surfaces, with useful implications on modulating the interfacial interactions of relevant materials in various engineering and bioengineering applications.

Keywords: Fluorinated surface; Hydrocarbon surface; Hydrogen bonds; Hydrophobic mechanisms; Ordered water layer.