Hi

I normally use 1% w/v in 0.1 or 0.2M of acetic acid and I never had problem of dissolving them though we work with big range of chitosan.

Good luck

Dissolving high amount of chitosan in aqueous solution is always time consuming. I usually use more acidic solution and have never had this problem. I think it's a good idea to check the pH of the solution.

Thanks for your help Peter, but I did some calculations and it seems that I am working with 0.17 M acetic acid and my final concentration of chitosan should be

0.5% w/v. I think that the problem could be the DD% of the chitosan, which I don't know yet.

hi Simona Di Blasio

Solubility of chitosan depends on what kind of chitosan you use

I tried 4 different kind of chitosan. Two of them for example :

High viscosity Chitosan, from shrimp shells "sigma aldrich" dd 80% was dissolved in 0.25% v\v acetic acid in one week but in 0.5 acetic acid in two days WITH of course different pH.

Any way, another chitosan - food-grade acid-soluble chitosan dd 75-95 %.- was dissolved in 0.25% v\v acetic acid but left alot of impurity and was cloudy. so I think the problem is the quality of Chitosan and just its purity

I’ve been also working with the same chitosan mw as you. The main concern that you should have is adding some acetic acid droplets (under stirring) do decrease the pH value in order to put chitosan in the solvated state. Chitosan can crosslink itself in higher pH values.

Low MW chitosan LMWC is highly water soluble.