Unexpected Homogeneous Bubble Nucleation near a SolidィCLiquid Interface
Unexpected Homogeneous Bubble Nucleation near a SolidィCLiquid Interface
复制标题
固体 C-液体界面附近意外的均质气泡成核
DOI：
10.1021/acs.jpcc.8b09200
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Koji;
中科院分区：
文献类型：
--
作者：
Tomo;Yoko; Li;Qin-Yi; Ikuta;Tatsuya; Takata;Yasuyuki; Takahashi;Koji;
我们报道了利用液体细胞电子显微镜在1000 nm厚的水层内对电子束诱导的纳米气泡的准三维观察。在观察初期，发生了非均相气泡成核，小气泡在相互接触时与相邻气泡合并。然而，我们首次发现，经过长时间的电子束辐照后，非均形成核不再发生，即使有固体表面可供非均形成核，也开始出现均形成核。我们得出结论，奥斯特瓦尔德成熟效应阻止了非均相成核的发生，离子和自由基的产生导致的较低的表面张力促进了均相成核的发生。研究还发现，均形核的生成点位于已有界面气泡三相接触线的下方。
We report a quasi-three-dimensional observation of electron-beam-induced nanobubbles inside a 1000 nm thick layer of water using the liquid cell electron microscopy. In the early stage of observation, heterogeneous bubble nucleation occurred, and small bubbles coalesced with the adjacent bubbles when they come in contact with each other. However, for the first time, we found that after prolonged electron beam irradiation heterogeneous nucleation did not occur more, and then homogeneous nucleation started even though a solid surface was available for heterogeneous nucleation. We conclude that the Ostwald ripening effect prevents heterogeneous nucleation from occurring and that the lower surface tension due to the generation of ions and radicals boosts the homogeneous nucleation. It was also discovered that the generation sites of homogeneous nucleation are beneath the three-phase contact lines of existing interfacial bubbles.