Furthermore, it was shown that the pH range of 6.5 to 7.2 and 5.6 to 10.0 was optimal for the stability of micelle holding DT for Brij S20 and Brij 58 respectively, as lowering the pH interferes with micelle formation. Lowering the pH causes the concentration of hydronium ions in water to rise, as was mentioned in section 3.1. As a result, the micelles' surface charges become neutral, which is followed by enlargement due to coalescence and, in the end, the micelle formation becomes unstable.