Zhou, Wentao (2023-05). Investigation into the Microorganisms Repelling Behavior of Superhydrophobic Modified Metal Surfaces for Antifouling and Anticorrosion. Master's Thesis.
Thesis
Galvanized steel is commonly used in food production processes and also as food shelving and bench surfaces because zinc provides enhanced corrosion resistance. However, upon exposure to fungus, bacteria and their metabolites, the rusting rate of galvanized steel can become significant. Furthermore, attachment of pathogenic fungus and bacteria on the food contact surfaces constitute an important risk factor in the context of food safety. Herein, we report an antifouling coating on galvanized steel surfaces that demonstrates anticorrosion and antifouling properties against pathogenic fungus and bacteria. This coating relies on the synergistic effect achieved through the combination of nanotexture and low surface energy chemical modification on galvanized steel surfaces to render them superhydrophobic. Contamination of unmodified galvanized steel samples with Aspergillus niger fungi was effectively prevented with the superhydrophobic coating. In addition, the self-cleaning property of the superhydrophobic coating reduced mud attachment on coupons by more than an order of magnitude. Meanwhile, upon applying the coating, the attachment of both gram-negative Salmonella enterica Typhimurium LT2 and gram-positive Listeria innocua model bacterial pathogens was reduced more than 99.3%, compared to unmodified surfaces. Furthermore, utilizing the developed coating, the rate of corrosion in the presence of Salmonella bacteria was also more than halved. Overall, we anticipate that coating technology could represent a significant contribution to the field of food safety and processing by mitigating the risks and economic burdens associated with microorganism contamination and corrosion.
