Investigate the Effect of Coating Concentration and Coating Thickness on the Anti-microbial Properties of Polycarbonate Sheet

Abstract

This paper investigates the effect of coating concentration (ppm), and coating thickness (µm) on the anti-microbial properties of polycarbonate sheets using a variety of anti-microbial agents (Cu-infused Mg(OH)2, Mg(OH)2, Cu(OH)2, MgO, CuCl2.2H2O, and ZnO). In addition, a complete analysis was performed for all agents to rank the best agent in terms of the highest anti-microbial performance against E. coli K-12 MG1655 in two time intervals (4 and 24 hours). The coating concentration (ppm) was found to be a significant factor in the anti-microbial characteristics for Cu-infused Mg(OH)2, Mg(OH)2, Cu(OH)2, MgO, CuCl2.2H2O, and ZnO (p = 0.004, p < 0.0001, p < 0.0001, p = 0.0297, p = 0.0011, and p = 0.0130 respectively). The coating thickness (µm), on the other hand, was found to be a major contributor to the anti-microbial properties of Cu-infused Mg(OH)2, Mg(OH)2, Cu(OH)2, MgO, and CuCl2.2H2O (p < 0.0001, p = 0.0004, p = 0.0011, p = 0.0310, and p < 0.0001 respectively). The analysis determined that the coating did not influence the anti-microbial properties of ZnO. The interaction between the coating concentration (ppm), and the coating thickness (µm) was found to be a significant factor for Cu-infused Mg(OH)2, Cu(OH)2, MgO, CuCl2.2H2O, and ZnO (p < 0.0001, p = 0.0001, p = 0.0004, p < 0.0001, and p < 0.0001 respectively), however, this was not a significant factor for Mg(OH)2. Highlights • The anti-microbial activity of the inorganic material is dependent on the particle shape and size. • Particles with sharp edges will provide additional physical injuries to the microorganisms. • Smaller particle size will provide higher surface area therefore better interaction with microorganisms. • The coating concentration and coating thickness will be crucial to the anti-microbial activity. • The thermal embossing techniques demonstrate good adhesion to the surface.