Figure 7.

Effect of cyclic short-term wear on antibacterial activity towards E. coli (a) in the ISO test format, photocatalytic activity (b) and hydrophobicity (c) of the surfaces based on matrix-embedded nano-ZnO and nano-ZnO/Ag. Antibacterial activity of nano-ZnO/Ag surfaces in dark conditions decreased (+0.99 logs; p = 0.0056), while antibacterial activity of nano-ZnO (−1.0 logs; p = 0.0032) and nano-ZnO/Ag (−0.90 logs; p = 0.019) surfaces under UVA increased during 10 cycles of reuse compared to virgin surfaces (a). The latter can be explained by an increase in photocatalytic efficiency of nano-ZnO/Ag surfaces after 10 reuse cycles, with 18% (p = 0.0125) and 22% (p = 0.0025) increase in organic dye degradation (b). All the surfaces changed towards more hydrophilic surface properties, reflected in water contact angle measurements, which decreased ≥10% (p < 0.05) and stabilized after 10 cycles of reuse, while the number of reuse cycles explained 47% variation between samples (p < 0.0001) and surface type had no significant effect on hydrophilicity (c). Mean value of 3 experiments ±SD is presented. Red dotted line denotes the practical limit of quantification with 3 colonies counted in undiluted samples.