State of water in citrate crosslinked chitosan membrane

The ionically crosslinked membranes were prepared of chitosan (Ch) and trisodium citrate (Ch/CIT). The characteristics of the state of water in crosslinked and uncrosslinked chitosan membranes with different water content was performed by differential scanning calorimetry (DSC). The kinetics of water swelling in Ch and Ch/CIT membranes were also studied. Conclusions concerning effect of ionic crosslinking on the state of water in chitosan hydrogel membranes were drawn out. Results shows that freezable and non-freezable water exist in analysed Ch and Ch/CIT membranes, while there are variations in the amount of non-freezing bound water in these polymers.