With a special cross-linking procedure, air-filled polyvinyl alcohol capsules can be produced in sizes ranging from 3-4 µm. These bubbles are stable for months, hydrophilic and uncharged. Due to the low degree of density, they slowly float in water to the top. In combination with an LbL coating, further functions can be added. The air can also be exchanged for water.
Fluorescent-microscopic images of air-filled microbubbles,
which are dyed with Rhodamine (image size 40 µm x 40 µm).