## 3 Results and Discussions
Kinetic favorable developments have also been seen for samples P4 (3% TiO\({}_{2}\)), P6 (4% TiO\({}_{2}\)) and P7 (5% TiO\({}_{2}\)). Different behavior was observed on samples P2 (1% TiO\({}_{2}\)) and P3 (2% TiO\({}_{2}\)) when small amounts water were sprayed (5 mL, 10 mL). The process rate increased, reaching a maximum after spraying a total amount of 15 mL of water. Later, the rate of the process decreases as the amount of sprayed water increases. This behavior was also noticed for P9 (10% TiO\({}_{2}\)). This kinetic behavior can be assimilated with a possible lower surface quality (in terms of self-cleaning capacity), respectively, as there is a tendency to form a water film, but the surface does not have the ability to maintain the continuity of this film. In all cases, as expected, the control sample (P1) shows a much reduced evolution of the water absorption process on the surface compared to the composite samples containing nanoparticles, a sign that this surface is less hydrophilic with most of the water remaining on the surface as droplets fail to form a film and easily fall. Generally, it can be stated that at the beginning of the process (when small amounts of water are sprayed), the evolution of surface water absorption is more strongly influenced by the amount of TiO\({}_{2}\) as the steps of the test increase. As the amount of sprayed water increases, the surface absorption process stabilizes, while the percentage of water added by each spray generally decreases. Figure 5 analyzes the efficiency of the presence of TiO\({}_{2}\) nanoparticles on the surface water absorption on the hydrophilicity of the surfaces of the cementitious matrix, expressed in terms of efficiency index of nanoparticles, depending on the type of samples at the total volume of sprayed water (50 mL) and the type of exposure. As emphasized by Figure 5 in the case of the test specimens without UV exposure, respectively, out of those tested with 1 h UV exposure, P8 (6% TiO\({}_{2}\)) samples show the highest efficiency in terms of the influence of addition of TiO\({}_{2}\) on surface hydrophilicity compared to the control sample. Sample P9 (10% TiO\({}_{2}\)) indicates a decrease in the efficiency of addition of nanoparticles on surface hydrophilicity. Regarding the P6 (4% TiO\({}_{2}\)) sample, followed closely by the P5 (3.6% TiO\({}_{2}\)) sample, the test results after 1 + 24 h UV exposure show the highest efficiency in terms of the influence of TiO\({}_{2}\) addition on surface hydrophilicity when compared to the control sample. The results presented in Figure 6 show that, regardless of the TiO\({}_{2}\) nanoparticles content for all samples, the surface water absorption increases when subjected to UV exposure compared to the lack  
Figure 5: Efficiency Index of Nanoparticles: (**a**) Non-UV test specimens, (**b**) 1 H UV test specimens, (**c**) 1 + 24 h UV test specimens. of UV exposure. The increase of exposure time has also the effect of increasing surface water absorption. The satisfactory behavior of the P8 (6% TiO\({}_{2}\)) test specimens, as well as the unsatisfactory behavior of the P9 (10% TiO\({}_{2}\)) test specimens and the highly dependent role of the UV exposure conditions of the other test specimens, can easily be noticed in the figure above.