Generation and In Situ Electrochemical Detection of Transient Nanobubbles
Generation and In Situ Electrochemical Detection of Transient Nanobubbles
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DOI：
10.1021/acs.jpcc.0c00435
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发表时间：
2020-04-02
影响因子：
3.7
通讯作者：
Denuault, Guy
中科院分区：
文献类型：
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作者：
Birkin, Peter R.;Linfield, Steven;Denuault, Guy
纳米气泡是一种迷人但有争议的物体。虽然有强有力的证据表明存在表面结合的纳米气泡，但在体中稳定纳米气泡的可能性仍然存在问题。在这项工作中，我们展示了电解液的超声如何产生瞬态体纳米气泡。为了做到这一点，玻璃纳米孔被用作库尔特计数器来检测纳米气泡。超声作用过程中，这些瞬态体积纳米气泡以相对高浓度存在，而靠近孔隙的固体介质表面的气泡活性是由超声驱动的。然而，在超声源终止后，这些气泡的瞬态性质是明显的。高速成像表明，这些瞬态纳米气泡起源于较大气泡的破碎，这些气泡在声场中滑过结构表面。可以检测到半径小至100纳米的瞬态纳米气泡。与先前的微泡研究相反，没有发现这些纳米泡在转运过程中振荡的证据。本文提出的新实验方法为体溶液中瞬态纳米气泡的存在提供了强有力的证据。
Nanobubbles are fascinating but controversial objects. Although there is strong evidence for the existence of surface bound nanobubbles, the possibility of stable nanobubbles in the bulk remains in question. In this work, we show how ultrasonication of electrolytes can create transient bulk nanobubbles. To do this, glass nanopores are used as Coulter counters to detect nanobubbles. During ultrasonication, these transient bulk nanobubbles are shown to exist in relatively high concentrations while bubble activity on the surface of a solid media close to the pore is driven by ultrasound. However, the transient nature of these bubbles is evident upon termination of the ultrasonic source. High-speed imaging suggests that these transient nanobubbles originate from the fragmentation of larger bubbles, which skate over the surface of the structure in the acoustic field present. Transient nanobubbles as small as similar to 100 nm in radius are detected. In contrast to previous work with microbubbles, no evidence for the oscillation of these nanobubbles during translocation was found. The novel experimental approach presented here provides strong evidence for the existence of transient nanobubbles in bulk solution.