CONICET | Buscador de Institutos y Recursos Humanos

Due to the serious concern caused by microbial contamination in food industry and infection arising from medical applications, an intense search for new materials has been generated. The development of active carrier nanocomposite doped materials with antibacterial, antioxidant, and improved mechanical properties is the new goal searched in food, plastics, cardboard packaging industries, etc. The addition of small percentage of organo-montmorillonite had been proved to enhance some of the nanocomposite mechanical properties, whilst the bactericide effectiveness against Staphylococcus aureus of Cetylpyridinium chloride (CP) sorbed on a Montmorillonite (Mt), from Middle Anatolia, Turkey was proved previously. The purpose of this work was to characterize and compare a native Mt from Río Negro, Argentine (Mt-A) and that from Turkey (Mt-T), and their products prepared exchanging CP with 50% of the cation exchange capacity (CEC). The percentage was previously determined as the minimum quantity of CP to maintain bactericide capacity in Mt-T. The CP adsorbed on Mt-A and Mt-T, respectively, shifted the d001 peak 0.31 and 0.37 nm, on the XRD spectra, with respect to the corresponding raw samples, indicating the entrance of CP to the Mt interlayer. By thermogravimetric analysis (TG), the CP addition produced an increase of around 7 % mass loss in the range from 200 to 550°C assigned to the CP (234.6°C) decomposition. Analysis of Zeta potential curves in the pH range from pH 3 to 12, indicated a decrease of negative charge in Mt-A-CP sample with respect to Mt-A, while no variation in external charge was found between Mt-T-CP and Mt-T samples.These results indicate that although the exchanged CP amount was similar in both Mt, in Mt-A both interlayer and external sites interacted with CP, while in Mt-T the interlayer sites were mainly used to bond CP.