## 3 Results
### Mechanism of Action of Antibacterial Properties  
Using the TiO\({}_{2}\)+Ag+O\({}_{2}\) material, tests were carried out to describe the mechanism of action of the material deposited on the foils--i.e., the inhibition of development in the respective area or antibacterial effect at a specific time in the development of _Escherichia coli_. Thus, the described protocol was followed, but the samples were photographed at the initial moment of the inoculation of the medium (time 0) at 1 h, 2, 3, 4, 5, 9, 10, 11, 12, 13, 14, 15, 17, 18 and 24 h of incubation at 37 \({}^{\circ}\)C (Figure 7).  
Figure 6: The appearance of the development of Escherichia coli with a concentration of \(10^{4}\) CFU/mL under the conditions of using the foils deposited with SiO\({}_{2}\)+Ag, TiO\({}_{2}\)+Ag, TiO\({}_{2}\)+Ag+O\({}_{2}\) and the non-deposited sample (reference sample—REF).  
By preventing or regulating the microbial biofilm architecture of surfaces, antifouling coatings inhibit biofilm deposition on surfaces [9]. Antimicrobial coatings, on the other hand, only function by means of bacteriostatic or bactericidal action [9]. The latter exploits the method of contact killing or releases the antibacterial chemicals or inorganic metal ions that induce cell death, while the former is based on the mechanism of steric repulsion or nanoscale-based topographies. The polymers are classified as either active (killing) or passive (repelling) materials based on their antibacterial activity and associated mechanism [61]. This test shows that bacterial development between 0 and 5 h does not occur, but bacterial cultures appear between 5 h and 9 h of incubation. However, from the first 9 h of incubation at 37 \({}^{\circ}\)C, bacterial cultures do not develop around and under the film deposited with TiO\({}_{2}\)+Ag+O\({}_{2}\) (Figure 8a). This trend is maintained during the 24 h of incubation at 37 \({}^{\circ}\)C--no _Escherichia coli_ colonies appeared around and under the TiO\({}_{2}\)+Ag+O\({}_{2}\) film (Figure 8b).  
The diameter of the zone of inhibition after the 24 h of incubation of the media at 37 \({}^{\circ}\)C was 1.841 \(\pm\) 0.142 for the sample deposited with TiO\({}_{2}\)+Ag+O\({}_{2}\), while the non-deposited sample did not register bacterial activity. The low surface energy of the matrix and hydrophilic/hydrophobic and electrostatic repulsions are the primary sources of the \"repelling\"-based process. Electrostatic and biocidal interactions are the foundation of the  
Figure 8: Aspect of the development of Escherichia coli of concentration 10\({}^{4}\) CFU/mL under the conditions of using the films deposited with TiO\({}_{2}\)+Ag+O\({}_{2}\) and the non-deposited sample after 9 h (**a**) and after 24 h (**b**) of incubation (with the samples removed).  
Figure 7: The aspect of the development of Escherichia coli with a concentration of 10\({}^{4}\) CFU/mL under the conditions of using the films deposited with TiO\({}_{2}\)+Ag+O\({}_{2}\) and the film not deposited at different incubation intervals.  
\"killing\"-based process [61]. Gram-negative bacteria have a thick layer of lipopolysaccharide-grade in their cell walls, with a relatively thin layer of peptidoglycan; this thick peptidoglycan structure of the cell wall can limit the penetration of AgNPs into the cells. The internalization of AgNPs is vital for their antibacterial activity for this type of bacteria [43].