Characterization and use of radio frequency plasma-activated natural polymers

A group of natural materials having anhydroglucose units linked by glycosidic bonds, as well as other related compounds, were irradiated with plasmas generated by a radio frequency field (13.56 MHz). Reactive sites created were characterized by electron spin resonance, chemiluminescence, infrared, and x‐ray photoelectron spectroscopy. The free radicals are related to the number of glycosidic bonds, and their decays result in chemiluminescence. In the absence of moisture and oxygen, however, the radicals are stable. During plasma irradiation, carbonyl groups as well as free radicals are formed on surfaces, and the atom ratio of oxygen to carbon on surfaces increases. Within the reactor, thin films of polymers can be deposited on cotton fabrics by allowing the monomer to enter the reactor above the fabric that is in a horizontal position downstream from the external electrodes.