Response to Comment on Bulk Nanobubbles or Not Nanobubbles: That is the Question

Advanced techniques that combine high spatial resolution with chemical sensitivity to directly probe the observed nanoentities and provide direct evidence that they are truly gas-filled nanobubbles do not exist. Therefore, in our paper, we focused on providing, for the first time, multiple types of indirect evidence using a variety of physical and chemical techniques that the nanoentities are not due to contamination and, hence, they must be bulk nanobubbles (BNBs). It should be noted that such techniques require good experimental skills, sound protocols, good scientific expertise, and reliable equipment. While no single piece of indirect evidence on its own can be considered as conclusive proof, we estimate that our results combined provide strong evidence that bulk nanobubbles do exist and they are stable. The work presented in our paper is the culmination of a series of studies, and many authors have either directly or indirectly confirmed our findings. Nonetheless, in their Comment, Rak & Sedlak reject all of the work we reported. We here address their comments point by point and show that their criticisms are unwarranted and unfounded, as follows.

Automated summary

The paper focuses on providing indirect evidence for the existence of bulk nanobubbles using various physical and chemical techniques, which require good experimental skills, sound protocols, and reliable equipment. Although no single piece of direct evidence is conclusive, combining multiple results provides strong support for the existence of bulk nanobubbles.