Comparative study on gamma irradiation and cold plasma pretreatment for a cellulosic substrate modification with phenolic compounds

• A two steps procedure was applied to bond phenolic compounds onto cellulose/chitin substrate.
• γ-irradiation or cold plasma were used to activate a cellulose/chitin mix substrate.
• Some vegetable oils containing phenolic compounds were reacted with pre-activated substrate.
• By bonding of phenolic compounds antimicrobial/antioxidant materials were obtained.

The efficiency of the activation of the cellulose/chitin mix substrate by cold plasma or γ-radiation exposure in order to modify it with bioactive compounds was studied. The eugenol or vegetable oils such as grape seed oil and rosehip seed oil have been grafted onto activated substrate. The examination of modified cellulose/chitin mix substrate by ATR-FTIR spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy confirms that the structural and morphological changes took place in both cases.The grafting degrees of the surface layer estimated from XPS data varied from 31.1% to 58.7% for air cold plasma activation and from 9.7% to 22.8% for γ-irradiation treatment. They depend both on bioactive compound used and procedure of substrate activation. Higher grafting degree are obtain by using vegetable oils than in the case of modification with eugenol and the air cold plasma activation seems to be much efficient than γ-irradiation.By grafting the polymeric substrate with bioactive compounds, antimicrobial and antioxidant properties have been conferred. Such materials can be considered promising for food packaging applications and medical textiles and also the applied procedures are environmental friendly ones.