Effective Chitosan Solubility in 1% Acetic Acid: Tips and Tricks

[Ngo Hoang An]

I am trying to create a solution of Chitosan (Low MW) in 1% Acetic acid. I've tried dissolving up to 3gr per 100ml. My problem is that by using extensive sonication, heating (~50 C) and stirring for days the solution is still very thick (very viscous) and you can see particles in it. Any suggestion to make chitosan soluble?

 

[Navin A S]

It sounds like your chitosan is not fully dissolving in the acetic acid. There are a few things you can try to help it dissolve: 1) Increase the concentration of the acetic acid. Chitosan is more soluble in stronger acids, so increasing the concentration of acetic acid may help it to dissolve.2) Try adding other solvents. Chitosan is more soluble in some organic solvents such as isopropanol, ethanol, and acetone. Adding small amounts of these solvents to the solution may help the chitosan to dissolve. 3) Add surfactants. Chitosan is more soluble in the presence of surfactants such as sodium dodecyl sulfate (SDS) or Tween 20. Adding small amounts of these surfactants may help the chitosan to dissolve. 4) Increase the temperature. Chitosan is more soluble at higher temperatures, so increasing the temperature of the solution may help it to dissolve.5) Try using a different form of chitosan. If none of the above methods work, you may need to try using a different form of chitosan such as a higher molecular weight or a different type of chitosan.