## 3 Results and Discussion
The decrease in the absorbance could be explained by different water content and various intermolecular interactions between polysaccharide molecules and nanoparticles. Size exclusion chromatography results are presented in Table 1. It shows an increase in the molecular weight in the samples containing nanoparticles. The highest increase was observed after the generation of Au nanoparticles. We could also notice an increase in the radii of gyration in both nanomaterial solutions compared to native ALG. This observation can be explained by interactions between sodium alginate, graphene oxide and nanometals. The DSC charts presented in Figures 6 and 7 show that as a result of heating, all samples release water which is observed in the first endo peaks. The ALG/Au/GOX and ALG/Ag/GOX samples have peaks shifting towards higher temperatures (maximum above 100 \({}^{\circ}\)C) relative to the reference sample (ALG) which indicates a higher water binding enthalpy. These samples bind more water and to a stronger extent than the sample with sodium alginate alone. Water in the nanosilver sample is bound more strongly than  
Figure 5: FTIR spectra of ALG (black line), ALG/Au/GOX (red line), ALG/Ag/GOX (blue line) and GOX (green line). water in the nanogold sample. In contrast, the water content of the nanogold sample is slightly higher than that of the nanosilver sample. The strong endo effect at 195-196 \({}^{\circ}\)C for the ALG/Ag/GOX sample in air and argon indicates the rapid evaporation of water due to vesicle rupture. This indicates that the texture of this porous material is tight and has closed vesicles. The ALG/Au/GOX sample also shows a similar effect, but it is much smaller, which may indicate that the vesicles are much smaller due to the smaller size of the gold nanoparticles. The sample containing only sodium alginate does not have this endo peak. All samples are stable up to a temperature of about 200 \({}^{\circ}\)C.  
Figure 6: DSC chart in argon: ALG (black line), ALG/Ag/GOX (blue line), ALG/Au/GOX (red line). Figure 7: DSC chart in air: ALG (black line), ALG/Ag/GOX (blue line), ALG/Au/GOX (red line). The exo peak in the range of 205-215 \({}^{\circ}\)C comes from sodium alginate. The system obtains stabilization and releases energy which may be related to crosslinking. Above 215 \({}^{\circ}\)C, there are thermal effects, characteristic of the caramelization and carbonization of polysaccharides. The results of the wettability of the samples and the surface free energy are presented in Table 2. As can be seen, the wettability of the samples differs slightly after adding silver or gold nanoparticles. However, the difference between the samples is not that big. Only the ALG/Ag/GOX film shows slightly greater hydrophobic properties than the original reference ALG alginate film. The surface free energy analysis confirms the initial assumptions of the wettability research. In foil containing silver, the dispersion energy is lower than in foil without any additives (or in foil with gold). The obtained results also correlate with the DSC results. The two-step hydrolysis reaction of materials by alginate lyase is a zero-order reaction, where \(\
u=k\) (curves depicting oligosaccharides vs. reaction time are linear (Figure 8)). The reaction rate constants of each step were determined by a graphical method (linear regression) [47]. The inverse value of the line slope coefficient equals the value of the reaction rate constant (Table 3). \begin{table}
\begin{tabular}{c c c} \hline \hline
**Sample** & **Contact Angle** & **Surface Free Energy** \\ \hline  & **Water** & **Diiodomethane** & **Polar (m/m2)** & **Dispersive (m/m2)** \\ \hline ALG & 36.95 & 52.8 & 22.80 & 36.74 & 59.54 \\ ALG/Au/GOX & 39.8 & 56 & 21.30 & 35.98 & 57.28 \\ ALG/Ag/GOX & 46.95 & 56.15 & 22.34 & 30.10 & 52.44 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The wettability and surface free energy of studied foil samples: ALG, ALG/Au/GOX and ALG/Ag/GOX.