Institute of Physics , Academia Sinica , Sec. 2, 128 Academia Road , Taipei 11529 , Taiwan , ROC.
Department of Physics , National Taiwan University , No. 1, Sec. 4, Roosevelt Road , Taipei 10617 , Taiwan , ROC.
Langmuir. 2018 Dec 18;34(50):15360-15369. doi: 10.1021/acs.langmuir.8b03016. Epub 2018 Dec 7.
We investigated how the stability of aqueous argon surface nanobubbles on hydrophobic surfaces depends on gas adsorption, solid-gas interaction energy, and the bulk gas concentration using molecular dynamics simulation with the SPC/E water solvent. We observed stable surface nanobubbles without surface pinning sites for longer than 160 ns, contrary to previous findings using monoatomic Lennard-Jones solvent. In addition, the hydrophobicity of a substrate has an effect to reduce the requirement degree of oversaturation on water bulk. We found that the gas enrichment layer, gas adsorption monolayer on the hydrophobic substrate, and water hydrogen bonding near the interface are likely necessary conditions for nanobubble stability. We concluded that gas nanobubble stability does not necessarily require three-phase pinning sites.
我们使用 SPC/E 水分子溶剂的分子动力学模拟研究了气体吸附、固-气相互作用能和体相气体浓度如何影响疏水表面上水的氩气表面纳米气泡的稳定性。我们观察到，与使用单原子 Lennard-Jones 溶剂的先前发现相反，在没有表面钉扎位的情况下，表面纳米气泡稳定存在的时间超过 160ns。此外，基底的疏水性会降低对水的过饱和度的要求程度。我们发现，气体富集层、疏水基底上的气体吸附单层以及界面附近的水分子氢键可能是纳米气泡稳定的必要条件。我们的结论是，气体纳米气泡的稳定性不一定需要三相钉扎位。
