Molecular dynamic simulations of bulk nanobubbles: Investigation of factors important to their stability
Nanobubbles are gas-filled bubbles in liquids with a diameter in the 100 nm range. Due to their small size and their long-term stability (up to months), there are various applications available in numerous fields, including medicine, agriculture, water remediation, washing, and mining. Although there are numerous applications and much research has been performed, there is a lack of insight into the stability of bulk nanobubbles. Since bubble pressure is an important parameter for bubble stability, in this project we have used molecular dynamics simulations to investigate nanobubbles in water and factors affecting the pressure. For all simulations, the TIP4P/2005 water model was used. A suitable method to calculate the short-range interactions in nanobubble simulations was explored and the particle mesh Ewald summation method was shown to be superior to the cut-off method. The pressure in systems with different sized nanobubbles was measured to examine whether there may be other contributions in addition to the Laplace pressure. The radii and positions of the bubbles were calculated based on the densities of slices through the systems. The results confirmed that pressure is impacted by factors other than the Laplace pressure, where long-range dipole-dipole interactions are found to play an important role. A manifestation of this was the observation that the distance between adjacent bubbles can effect the pressure.
Nanobubbles MD simulations
Pathirannehelage, N. S. P. (2023). Molecular dynamic simulations of bulk nanobubbles: investigation of factors important to their stability (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.