Effect of the formation of open microcapsules with Mn3O4 walls during hydrolysis of the MnSO4 salt solution droplets deposited on the alkaline solution surface

It was shown for the first time that open microcapsules 1–5 µm in size with Mn3O4 walls and unique morphology are formed as a result of spraying an aqueous MnSO4 solution onto the surface of an alkali solution. The walls have a thickness of 80–120 nm and consist of an array of Mn3O4 nanosheets with a thickness of 2–3 nm, oriented predominantly in the radial direction towards the center of the microcapsule. There is a special rim with a height of 100–200 nm around the hole of the most microcapsules, which can be a kind of ‘ground’ when fixing such microcapsules on the surface of a substrate in the process of application by the Langmuir–Schaefer technique.