Development of novel antimicrobial surfaces from valorised municipal waste and biodegradable plastics

Common practice compounding of plastic substrates of virgin polymer type and waste origin was achieved to mimic real-world conditions for the desired materials tested in this study. This includes a polyolefin virgin grade, plastic waste, prodegradant additive with a virgin polyolefin and the compostable bioplastic, which were compounded using a number of extrusion techniques. The substrates were then coated with nano-powders divided into four groups, (i.e. Group A: Cu_53.3Zr_25.5Nb_12.9N_i8.3, Group B: CuZn₅₄Zr₂₅Nb₁₄Ni₇, Group C: Cu₄₈Ti₁₇Ni₂₈Zr₅Ag₂ and Group D: Cu₈₅/SUS316L₁₀/Ag₅) leading to a 24 matrix of samples in the experimental design. The in vitro viral toxicity assay revealed that Group B surfaces were best against human coronavirus OC43. Within this category, Sample 6 bioplastic was the most promising as it provided a log₁₀ reduction of −4.75 in just 4h. Based on this work, Group B (e.g. CuZn₅₄Zr₂₅Nb₁₄Ni₇), which has a base of copper (Cu) with a nominal atomic percentile equal to unity, is more effective than the other metal powders considered. The surfaces were also tested against two pathogenic bacterial strains (Staphylococcus aureus and Escherichia coli), with results showing antibacterial properties, namely for Group B substrates. This work could lead to the development of self-cleaning surfaces in various hygienic commodities and applications within the medical and packaging sectors.