Effect of iodine treatment on morphological control in carbonization of polysaccharides

An iodine treatment was applied to control the morphology in carbonization of polymer films prepared from two kinds of polysaccharides, starch and chitosan. Differences in carbonization properties of the films with or without the iodine treatment were investigated by nitrogen adsorption, TG-Mass and Raman spectroscopy. Microporous carbon film was derived from the starch film with iodine stabilization, while non-porous one was done from the chitosan film without iodine stabilization. The char from the starch film was doubled in yield by the iodine treatment but that from the chitosan film remained almost unchanged. It is suggested that these differences in their carbonizations are attributed to the difference in the reactivity between each polysaccharide and iodine, which depends on their polymer conformations.