Stabilitet hos nanobubblor i saltlösningar

Abstract

Studies about bulk nanobubbles are relatively new and it was only in recent years that bulk nanobubbles were shown to exist. Many of their properties are still poorly investigated, including their stability. The goal of this project was to study the stability of air-filled bulk nanobubbles in aqueous solutions of MgSO4, CaCl2 and NaCl. The purpose was to investigate whether there is a clear connection between the stability of the bulk nanobubbles and the concentration of the salt. The amount of bulk nanobubbles and their size was investigated using Photon Correlation Spectroscopy. For several salt concentrations, bulk nanobubbles were generated using a high speed stirrer. Measurements were made at several points in time after the generation. The measured intensities from four angles, between 97° and 148°, were used to analyze the variations in the amount of bulk nanobubbles. The results show that the initial amount of bulk nanobubbles varies greatly between the samples and lacks correlation with the concentration of salt. The amount of bulk nanobubbles decreases with time, possibly exponentially. From the result, no clear relation can be seen between the stability of bulk nanobubbles and the concentration of salt.