## 3 Results and Discussion
### AFM Analysis  
Figure 5 displays the bi-dimensional AFM topographic images of samples F1 and F2 deposited on glass substrates, at a scale of 4 \(\upmu\)m \(\times\) 8 \(\upmu\)m. AFM images were scanned firstly over larger scales, in order to prove that the films were adherent to the substrate used and to check the corrugation of the surfaces. Sample F1 exhibited random \"bumps\" which were a few nm in height and 100-300 nm in diameter (see Figure 5a and the red line in Figure 5c), and, additionally, a few pits no deeper than 10 nm (see the green line in Figure 5c). Sample F2 showed some wavy-like parcels (as seen in the red line from \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**30–100 \({}^{\circ}\)C**} & \multicolumn{2}{c}{**100–240 \({}^{\circ}\)C**} & \multicolumn{2}{c}{**240–750 \({}^{\circ}\)C**} & \multicolumn{2}{c}{**Resolute at 750 \({}^{\circ}\)C**} \\ \cline{2-7}
**Sample** & **Wt. Loss** & **Wt. Loss** & **T\({}_{\text{max}}\) 1** & **Wt. Loss** & **T\({}_{\text{max}}\)** & **N\({}_{\text{2}}\)** \\  & **\%** & **\%** & \({}^{\circ}\)C** & **\%** & \({}^{\circ}\)C** & **\%** \\ \hline F1 & 3.64 & 7.94 & 131.6 & 4.04 & 470.7 & 84.37 \\ F2 & 1.38 & 2.59 & 114.1 & 27.31 & 518.8 & 68.72 \\ \hline \hline \end{tabular} \({}^{\dagger}\)T\({}_{\text{max}}\) (\({}^{\circ}\)C) = T(d\(\upalpha\)/dt)\({}_{\text{max}}\).  
\end{table} 
Table 1: The maximum decomposition temperature (T\({}_{\text{max}}\)) and weight loss (Wt. loss %) of the fluorinated silica materials, obtained as powdered materials (30–750 \({}^{\circ}\)C range). Figure 3: TGA curves of the fluorinated silica materials (as powdered materials): TEOS/MTES/FS (F1) and TEOS/MTES/HDTMES/FS (F2). Figure 5d) and some deposits of materials (see the right down corner), but in between these defects, the surface was uniform (see the green line in Figure 5d). Figure 6 exhibits the morphology of samples F1 and F2, deposited on glass substrates. It was obtained from bi-dimensional AFM topographic images, scanned over an area of 2 \(\upmu\)m \(\times\) 2 \(\upmu\)m.  
Figure 4: The TEM images of fluorinated silica materials (powdered samples): TEOS/MTES/FS (F1), and TEOS/MTES/HDTMES/FS (F2). Figure 5: 2D AFM images (enhanced contrast) scanned over 4 \(\upmu\)m \(\times\) 8 \(\upmu\)m, together with two representative line scans collected along the X-axis (the positions are indicated in each AFM figure) for fluorinated hybrid coatings: sample F1 (**a**,**c**) and sample F2 (**b**,**d**). As can be observed from Figure 6a,b, on smaller scales of 2 \(\upmu\)m \(\times\) 2 \(\upmu\)m, both samples were relatively smooth, as observed from the arbitrary line-scans collected by Figure 6c,d in different areas. While sample F1 (Figure 6a) exhibited randomly distributed small pores, visible as dark spots a few nm deep (see the red line in Figure 6c), sample F2 (Figure 6b) presented level differences in the z-axis no higher than 6 nm (see the green line in Figure 6d). Figure 7 shows the root-mean-square roughness of the F1 and F2 coatings in comparison with the uncoated glass substrate. It can be seen that at low scales (2 \(\upmu\)m \(\times\) 2 \(\upmu\)m), both F1 and F2 coatings were smooth, as their RMS roughness's did not exceed 1.2 nm, while at larger scales (4 \(\upmu\)m \(\times\) 8 \(\upmu\)m), sample F2 became more corrugated due to some protuberances formed during film deposition. The roughness is in line with the values of water contact angles, but it is also influenced by the chemical differences between the fluorinated silica-based coatings. Figure 6: 2D AFM images (enhanced contrast) scanned over 2 \(\upmu\)m \(\times\) 2 \(\upmu\)m together with two representative line scans collected along the green and red lines (the positions are indicated in each AFM figure) for fluorinated hybrid coatings: sample F1 (**a**,**c**) and sample F2 (**b**,**d**).