Antibacterial treatment of LDPE with halogen derivatives via cold plasma

Abstract

The factor limiting the application of low-density polyethylene (LDPE) in healthcare is its high susceptibility to bacterial growth. For this reason, we here investigated antibacterial treatments of LDPE foils using appropriate antibacterial agents. Benzalkonium chloride and bronopol were selected because of their satisfactory antibacterial effect, which has been confirmed by their application in the medical and cosmetic industries. The aforementioned substances were immobilized by a multistep approach via the grafting of polyacrylic acid (PAA) brushes onto LDPE surfaces pre-treated with low-temperature plasma. Measurements of the surface energy, peel strength of the adhesive joints, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR), and atomic force micro scopy (AFM) were used to investigate the surface and adhesive properties of the antibacterial-treated LDPE. Moreover, the antibacterial effect was determined via measurements of the inhibition zone of the Staphylococcus aureus (S. aureus) bacterial strain. The antibacterial activity of benzalkonium chloride was observed to be more pronounced than that of bronopol. Inhibition- zone measurements of Escherichia coli (E. coli) were also conducted, but an antibacterial effect was not observed.