title: Preparation of chitosan-coated polyethylene packaging films by DBD plasma treatment.
abstract: Polyethylene (PE) packaging films were coated with chitosan in order to introduce the antibacterial activity to the films. To augment the interaction between the two polymers, we modified the surfaces of the PE films by dielectric barrier discharge (DBD) plasma before chitosan coating. After that the plasma-treated PE films were immersed in chitosan acetate solutions with different concentrations of chitosan. The optimum plasma treatment time was 10 s as determined from contact angle measurement. Effect of the plasma treatment on the surface roughness of the PE films was investigated by atomic force microscope (AFM) while the occurrence of polar functional groups was observed by X-ray photoelectron spectroscope (XPS) and Fourier transformed infrared spectroscope (FTIR). It was found that the surface roughness as well as the occurrence of oxygen-containing functional groups (i.e., C═O, C-O, and -OH) of the plasma-treated PE films increased from those of the untreated one, indicating that the DBD plasma enhanced hydrophilicity of the PE films. The amounts of chitosan coated on the PE films were determined after washing the coated films in water for several number of washing cycles prior to detection of the chitosan content by the Kjaldahl method. The amounts of chitosan coated on the PE films were constant after washing for three times and the chitosan-coated PE films exhibited appreciable antibacterial activity against Escherichia coli and Staphylococcus aureus. Hence, the obtained chitosan-coated PE films could be a promising candidate for antibacterial food packaging.
authors.affiliation: The Petroleum and Petrochemical College, Petrochemicals, and Advanced Materials, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Siriporn
authors.initials: S
authors.lastname: Theapsak
authors.forename: Anyarat
authors.initials: A
authors.lastname: Watthanaphanit
authors.forename: Ratana
authors.initials: R
authors.lastname: Rujiravanit
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D048271:Chitosan / Q000737:chemistry*; D004926:Escherichia coli / Q000187:drug effects; D018625:Microscopy, Atomic Force; D056951:Photoelectron Spectroscopy; D020959:Polyethylene / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D020959:Polyethylene; D048271:Chitosan