- Tytuł:
- Multiscale water drop contact angles at selected silica surfaces
- Autorzy:
-
Zhang, Chen
Wang, Xuming
Li, Lixia
Jin, Jiaqi
Polson, Randy
Miller, Jan D. - Powiązania:
- https://bibliotekanauki.pl/articles/2146924.pdf
- Data publikacji:
- 2022
- Wydawca:
- Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
- Tematy:
-
contact angle
atomic force microscopy
hollow tip
submicron-drop
wettability
MD simulation - Opis:
- In this study, multiscale advancing contact angles for glycerol/water drops at silica surfaces are reported for millidrops, submicron-drops, and nanodrops. Selected silica surfaces were muscovite, silicon, and talc. The contact angles for millidrops (1–2 mm) were determined by the traditional sessile drop technique. For submicron-drops (0.1–1.0 μm), a hollow tip Atomic Force Microscope (AFM) procedure was used. The contact angles for nanodrops (~7 nm) were examined from Molecular Dynamics (MD) simulation. The results were compared to evaluate the effect of drop size on the contact angle. In the case of the hydrophobic talc surface, the 75° advancing contact angle did not vary significantly with drop size. For the hydrophilic muscovite surface, the water drop wet the surface and an advancing contact angle of about 10° was found for the millidrops and submicron-drops. However, for the MD simulated nanodrops, attachment and spreading of the ~7 nm drop created a 2D film of molecular dimensions, the contact angle of which was difficult to define and varied from 0° to 17°. Perhaps of equal interest from the MD simulation results was that the spreading of the glycerol/water nanodrop at the muscovite surface resulted in crystallographic directional transport of water molecules to the extremities of the 2D film. Such separation and segregation left the center of the film with an increased concentration of glycerol. Based on these results, the line tension, which has been found in other investigations to account for contact angle decrease with a decrease in drop size, does not seem to be a significant factor in this study.
- Źródło:
-
Physicochemical Problems of Mineral Processing; 2022, 58, 5; art. no. 152154
1643-1049
2084-4735 - Pojawia się w:
- Physicochemical Problems of Mineral Processing
- Dostawca treści:
- Biblioteka Nauki
Artykuł