Sub-micrometer gas-containing cavity, or bubble, in aqueous solutions
A nanobubble is a small sub-micrometer gas-containing cavity, or bubble, in aqueous solutions with unique properties caused by high internal pressure, small size and surface charge.[1][2] Nanobubbles generally measure between 70-150 nanometers in size [3][4] and less than 200 nanometers in diameter[5][6] and are known for their longevity and stability, low buoyancy, negative surface charge, high surface area per volume, high internal pressure, and high gas transfer rates.[2][7][8][9]
Nanobubbles can be formed by injecting any gas into a liquid.[10][11] Because of their unique properties, they can interact with and affect physical, chemical, and biological processes.[12] They have been used in technology applications for industries such as wastewater, environmental engineering, agriculture, aquaculture, medicine and biomedicine, and others.[7][13][14]