In this work, we study the wetting of a surface decorated with one nanogroove by a bulk Lennard-Jones liquid at various temperatures and densities. We used atomistic simulations aimed at computing the free energy of the stable and metastable states of the system, as well as the intermediate states separating them. We found that the usual description in terms of Cassie-Baxter and Wenzel states is insufficient, as the system presents two states of the Cassie-Baxter type. These states are characterized by different curvatures of the meniscus. The measured free energy barrier separating the Cassie-Baxter from the Wenzel state (and vice versa) largely exceeds the thermal energy, attesting the existence of Cassie-Baxter/Wenzel metastabilities. Finally, we found that the Cassie-Baxter/Wenzel transition follows an asymmetric path, with the formation of a liquid finger on one side of the groove and a vapor bubble on the opposite side.

Giacomello, A., Meloni, S., Chinappi, M., Casciola, C.m. (2012). Cassie-baxter and wenzel states on a nanostructured surface: Phase diagram, metastabilities, and transition mechanism by atomistic free energy calculations. LANGMUIR, 28(29), 10764-10772 [10.1021/la3018453].

Cassie-baxter and wenzel states on a nanostructured surface: Phase diagram, metastabilities, and transition mechanism by atomistic free energy calculations

Chinappi M.;
2012-01-01

Abstract

In this work, we study the wetting of a surface decorated with one nanogroove by a bulk Lennard-Jones liquid at various temperatures and densities. We used atomistic simulations aimed at computing the free energy of the stable and metastable states of the system, as well as the intermediate states separating them. We found that the usual description in terms of Cassie-Baxter and Wenzel states is insufficient, as the system presents two states of the Cassie-Baxter type. These states are characterized by different curvatures of the meniscus. The measured free energy barrier separating the Cassie-Baxter from the Wenzel state (and vice versa) largely exceeds the thermal energy, attesting the existence of Cassie-Baxter/Wenzel metastabilities. Finally, we found that the Cassie-Baxter/Wenzel transition follows an asymmetric path, with the formation of a liquid finger on one side of the groove and a vapor bubble on the opposite side.
2012
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore ING-IND/06 - FLUIDODINAMICA
English
Giacomello, A., Meloni, S., Chinappi, M., Casciola, C.m. (2012). Cassie-baxter and wenzel states on a nanostructured surface: Phase diagram, metastabilities, and transition mechanism by atomistic free energy calculations. LANGMUIR, 28(29), 10764-10772 [10.1021/la3018453].
Giacomello, A; Meloni, S; Chinappi, M; Casciola, Cm
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/247520
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