How to control bubble nucleation from superhydrophobic surfaces

9th International Symposium on Cavitation

Giacomello, Alberto^1 ; Amabili, Matteo^1 ; Casciola, Carlo Massimo^1

Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, via Eudossiana 18, Roma

00184, Italy^1

关键词: Bubble nucleation;    Classical nucleation theory;    Free energy molecular dynamics;    Heterogeneous structures;    Negative pressures;    Nucleation rate;    Super-hydrophobic surfaces;    Superhydrophobicity;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/656/1/012124/pdf
DOI  :  10.1088/1742-6596/656/1/012124

来源: IOP

【 摘 要 】

Superhydrophobicity is realized by entrapping gas bubbles inside surface roughness. While this strategy affords remarkable surface properties, it enhances the risk of cavitation from these gas nuclei at negative pressures. Here we use free energy molecular dynamics simulations and an extension of the classical nucleation theory to show that the relevant nucleation rates and barriers can be controlled by engineering the surface structure. Mimicking the re-entrant and chemically heterogeneous structure found in the leaves of the Salvinia molesta allows one both to stabilize the gas pockets against liquid intrusion and to reduce the risk of cavitation.