2012 : The Effect of Sonication on the Characteristic of Chitosan
This research aim was to study the effect of sonication process on the changes of chitosan characteristics such as molecular weight,chemical structure, degree of crystallinity and the amount of dissolved chitosan after sonication. Sonication process was conducted on a mixture of chitosan-bidest 1% (w/v) in a glass reactor during 10 - 120 minutes at temperature 20, 40, 60 oC and frequency sonication of 20 kHz. The sonication probe was inserted into a mixture of chitosan-bidest in the reactor, and sonication was performed on selected time and temperature sonication. After sonication, solid residue was filtered and dried before analyzed by viscometry, FTIR, XRD, and TOC to determine the changes of molecular weight, chemical structure, crystallinity, and the amount of the total organic carbon dissolved in the system. The results showed that molecular weight and degree of crystallinity of chitosan decreased for longer sonication time and higher temperature system. Moreover, the chemical structure was no changes on functional groups significantly and it was indicated that there were no new compounds formed. Total organic carbon from which degraded chitosan also increased for further sonication time because more organic carbon was dissolved in the system.