Nanobubble size distribution measurement by interactive force apparatus under an electric field

Nanobubbles have been applied in many fields, such as environmental cleaning, material production, agriculture, and medicine. However, the measured nanobubble sizes differed among the measurement methods, such as dynamic light scattering, particle trajectory, and resonance mass methods. Additionally, the measurement methods were limited with respect to the bubble concentration, refractive index of liquid, and liquid color. Here, a novel interactive force measurement method for bulk nanobubble size measurement was developed by measuring the force between two electrodes filled with bulk nanobubble-containing liquid under an electric field when the electrode distance was changed in the nm scale with piezoelectric equipment. The nanobubble size was measured with a bubble gas diameter and also an effective water thin film layer covered with a gas bubble that was estimated to be approximately 10 nm based on the difference between the median diameter of the particle trajectory method and this method. This method could also be applied to the solid particle size distribution measurement in a solution.

Automated summary

Nanobubbles have been widely used in various fields, but the measurement of their sizes has shown discrepancies across different methods. To address this issue, a novel interactive force measurement method was developed to measure the size of bulk nanobubbles. This method involved measuring the force between two electrodes filled with nanobubble-containing liquid under an electric field. The results showed that the size of nanobubbles was approximately 10 nm based on the gas diameter and the thin water film layer covering the bubbles. This method could also be applied to measure the solid particle size distribution in a solution.