Plasma enhanced modification of xanthan and its use in chitosan/xanthan hydrogels

This study reports the design and construction of a fluidized bed/non‐equilibrium atmospheric‐pressure‐plasma reactor. The mechanical design of the reactor was devised to modify chemically and physically the surface of different powders. The basis for developing the design and construction of the reaction system were the non‐equilibrium atmospheric‐pressure‐plasma phenomenon known as dielectric barrier discharge and the gas‐solid bubbling fluidization. The reactor was tested modifying xanthan powder that was used in the synthesis of chitosan/xanthan hydrogels, for which the swelling capacity was measured at different pH levels. The chemical modification of xanthan was carried out in a sequential process of plasma treatment with different exposure times and gas flow (from 0.5 to 5 min), followed by chemical vapor deposition of epichlorohydrin. The swelling experiments reveal that the hydrogels increase its swelling capacity in acidic mediums and when the hydrogel was formed with xanthan with 2 or 3 min of plasma treatment. POLYM. ENG. SCI., 54:2264–2271, 2014. © 2013 Society of Plastics Engineers