Arcot, Yashwanth (2021-04). Investigating the Bacteria Repellency and Durability of the Fabricated Superhydrophobic Coatings on High Density Poly-ethylene Based Food Contact Surfaces.. Master's Thesis.
Large epidemics of foodborne illness in the recent times have substantially increased the concerns over hygienic processing and, packaging environments in the food industries. Lack of maintenance and poor sanitation of the food contact surfaces result in air and, food-borne microbial attachment, contamination and, biofilm formation. With the increasing concerns over food safety and hygiene both for industries and consumers, it is important to keep the FCS bacteria-free, to protect the consumers from various foodborne illnesses. To resolve this problem, we plan to modify high-density polyethylene, one of the most common materials to make FCSs, used in the food industry, to manufacture of conveyor belts, storage boxes, cutting pads, and knives, using durable and superhydrophobic coating materials to prevent the formation of notches, cracks, and scratches on the surfaces that occur due to continual use, which aggravate the possibility of bacterial adhesion and cross-contamination on these HDPE based FCSs. The fabricated, highly durable, nano-diamond-based coatings on HDPE combined chemisorption of low surface energy organoflurosilane and rigid nanotexturing, achieved a static water contact angle greater than 150 ?, and demonstrated excellent mechanical durability with water-repellency sustained after 10,000 cycles of onion peel, and spinach leaf abrasion and, fifty cycles of sand abrasion. In comparison to the bare HDPE surfaces, the coated substrates showed over 97.75% reduction in the bacterial adhesion against Salmonella Typhimurium LT2 and Listeria innocua, two of the most common foodborne bacteria, predominantly transmitted by food contamination. Also, the coated substrates successfully reduced the cross-contamination of Salmonella Typhimurium LT2 and Listeria innocua by contaminated spinach leaf significantly. With this, we prove that these durable coating mechanisms can significantly contribute to reduce the potential bacterial contamination and cross-contamination by FCS in the food processing environment. Overall we demonstrate that these coated HDPE substrates could significantly help in improving the hygiene and safety in the food processing environment.