An experimental verification of the possible influence of gas nano-bubbles on the response of an electrochemical quartz crystal microbalance

Abstract

Electrochemical removal of oxygen and hydrogen from aqueous solution in the vicinity of gold electrodes, with simultaneous measurements of the response of the quartz crystal microbalance, show no evidence of gas nano-bubbles attached to the surface, irrespective of its roughness and hydrophobicity. The contact between gold and frozen electrolyte, which forms a liquid-like layer between them, also does not contain gas bubbles. These statements could be extended to nano-bubbles with characteristic dimensions larger than a few nanometers.

Nitrogen nanobubbles and butane nanodroplets at Si(100)

“…Although much has been studied about the nanobubble, the established knowledge is limited. For example, the experiments by the X-ray reflectometry (XR) [8] and the quartz crystal microbalance (QCM) [4] do not support the existence. The nanobubble is still the controversial topic in the surface science.…”

“…Unexpectedly, spontaneously assembled soft nano-structures have been successively reported in the last decade, which are nanometer size bubbles appearing at hydrophobic solid surfaces in contact with gas containing aqueous solutions [1][2][3][4][5]. These soft nano-structures are certainly ubiquitous in natural and also artificial systems such as the lungs [6] and the fuel cell [4,7].…”

“…Unexpectedly, spontaneously assembled soft nano-structures have been successively reported in the last decade, which are nanometer size bubbles appearing at hydrophobic solid surfaces in contact with gas containing aqueous solutions [1][2][3][4][5]. These soft nano-structures are certainly ubiquitous in natural and also artificial systems such as the lungs [6] and the fuel cell [4,7]. In spite of these ubiquities, the small size and the softness of the nanobubbles need to wait for the instrumental development in the non-invasive nano-imaging, the mainly tapping mode atomic force microscope (TM-AFM) [1,2] or the neutron reflectometry (NR) [3].…”

Hemispherical nanobubbles reduce interfacial slippage in simple liquids

“…The results shown below are of a similar kind as the ones reported in ref. 29. In particular, we have seen many examples, where we expected nanobubble formation and did not see corresponding changes in frequency or bandwidth.…”

“…Finally, there is an interesting and carefully performed study on electrochemically produced bubbles and the extent to which these lead to slip. 29 Interestingly, the experimental results remained inconclusive.…”