Influence of nanobubbles on the surface tension and atomization characteristics of water

Atomization of bulk fluid and its characterization is of importance in various applications like combustion of liquid fuels, crop sprays, and manufacturing. Influencing the physical properties of the fluid by different means is a way to achieve desired atomization quality. It has been recently reported that stable suspensions of nano-meter-sized bubbles in liquids can be obtained for a large number of liquid-gas combinations. The possibility of having a high concentration of such nanobubbles and the long-term stability of nanobubble suspensions can be seen as an opportunity to manipulate the physical properties of base liquid. The present study involves the introduction of oxygen nanobubbles in pure water, and characterization of the resulting nanobubble suspension, including the measurement of surface tension and its atomization by impinging jets. Our investigations reveal a surface tension drop of the order of 5 % to 12% of water on the introduction of nanobubbles. Correspondingly, better liquid atomization behavior in terms of drop in liquid sheet breakup length of the order 15% compared to pure water is also observed and reported in terms of the liquid sheet dimensions.