Generation of antifouling layers from polyethylene glycol by cold plasma technique on stainless steel and polymer surfaces

Biofilm is composed of colonies of microorganisms that are embedded in extracellular polymers produced by the microorganisms. Biofilm formation can lead to health and economic problems in many environments, including food processing and medical device industries. Surface modification of materials provides an alternative strategy for biofilm control. Polyethylene glycol (PEG) has been shown to reduce protein and bacterial adsorption on various surfaces. The objective of this dissertation is to generate antifouling PEG thin layers onto commonly used food-contact materials by cold plasma techniques.; PEG was successfully crosslinked onto stainless steel (SS) surfaces. PEG was spin-coated on oxidized SS surfaces and crosslinked by argon plasma. Electron Spectroscopy for Chemical Analysis (ESCA) suggested that macromolecular layers composed of CH2-CH2-O-units were present on the PEG-crosslinked SS. The antifouling ability was evaluated by the attachment and biofilm formation using Listeria monocytogenes. PEG-crosslinked SS showed significant decrease in both the attachment and biofilm formation.; In another approach, PEG was grafted onto SiCl4 plasma functionalized polyamide (PA) and polyester (PET) surfaces. The grafting condition was optimized and the effect of molecular weight of PEG was studied. ESCA data suggested that PEG was successfully grafted. The molecular weight of PEG affected the antifouling ability of PEG-grafted PET surfaces, and PET-PEG2000 showed maximum inhibition on the attachment and biofilm formation by both L. monocytogenes and Salmonella enterica. Significant reduction of biofilm formation by L. monocytogenes was also observed on PEG-grafted PA, SS, and SR surfaces, indicating the adaptability of this novel grafting approach.