# Comparative Studies on Nanocellulose as a Bio-Based Consolidating Agent for Ancient Wood
## 3 Results and Discussion
### Characterization of Treated Degraded Wood Samples

Table 13: Comparison of the colorimetric parameters (L\({}^{*}\), a\({}^{*}\), b\({}^{*}\)) of the nanocellulose-treated samples before the second treatment (Nanocellulose 2024) with data collected three years earlier from the same samples one month after the first treatment (Nanocellulose 2021). Figure 7: Reflectance spectra of untreated (NT) and treated samples (CNC, Paraloid B-72, Regalrez 1126), acquired in SCI and SCE mode, one month after the consolidation treatment. For the samples treated with nanocellulose, the most important parameter \(\Delta\)E was still less than five, and this had even decreased compared to 2021; on the contrary, for the samples treated with Paraloid B-72 and Regalrez 1126, all the parameters were increased, showing a variation in the visual aspect of the samples. All these results are described in Figure 8, where the comparison between the colorimetric data of the consolidating agents three years after the first treatment is shown. In this graph, we can observe that, in general, the trend of the curves corresponding to the different consolidants is very similar to that found three years before: the samples treated with nanocellulose were still more like the untreated sample, while the blue curves related to the samples treated with Regalrez 1126 were detached from those in pink of the samples treated with Paraloid B-72-- thus showing, over time, a behavior closer to that of nanocellulose. At this point, the wood samples were treated for a second time with the respective consolidating solutions, and the colorimetric measurements were repeated. In Tables 16-18, a comparison of the colorimetric parameters of each treated sample three years after the first treatment, with the data collected one week after the second treatment from the same samples, is shown. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & **L\({}^{*}\) (D65)** & **a\({}^{*}\) (D65)** & **b\({}^{*}\) (D65)** & & & \\ \hline \multirow{2}{*}{**Nanocellulose**} & SCI & 62.40 & 8.99 & 23.53 & & **\(\Delta\)L** & **\(\Delta\)C** & **\(\Delta\)E** \\ \cline{2-7}  & SCE & 62.21 & 9.02 & 23.58 & SCI & 0.34 & 2.88 & 2.90 \\ \hline \multirow{2}{*}{**Nanocellulose**} & SCI & 62.75 & 9.81 & 26.29 & SCE & 0.38 & 2.96 & 2.98 \\ \cline{2-7}  & SCE & 62.59 & 9.85 & 26.42 & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 16: Comparison of the colorimetric parameters (L\({}^{*}\), a\({}^{*}\), b\({}^{*}\)) of the nanocellulose-treated samples three years after the first treatment with data collected one week after the second treatment from the same samples. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & & **L\({}^{*}\) (D65)** & **a\({}^{*}\) (D65)** & **b\({}^{*}\) (D65)** & & & \\ \hline \multirow{2}{*}{**Paraloid B72**} & SCI & 51.88 & 12.96 & 26.25 & & \(\Delta\)L & **\(\Delta\)C** & **\(\Delta\)E** \\ \cline{2-7}  & SCE & 51.70 & 13.01 & 26.36 & SCI & \(-\)0.42 & 5.54 & 5.56 \\ \hline \multirow{2}{*}{**Paraloid B72**} & SCI & 51.46 & 15.43 & 31.21 & SCE & \(-\)0.38 & 5.54 & 5.55 \\ \cline{2-7}  & SCE & 51.32 & 15.47 & 31.32 & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 14: Comparison of the colorimetric parameters (L\({}^{*}\), a\({}^{*}\), b\({}^{*}\)) of samples treated with Paraloid B-72 before the second treatment (Paraloid B-72 2024) with data collected three years earlier from the same sample one month after the first treatment (Paraloid B-72 2021). \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & **L\({}^{*}\) (D65)** & **a\({}^{*}\) (D65)** & **b\({}^{*}\) (D65)** & & & \\ \hline \multirow{2}{*}{**Regalrez 1126**} & SCI & 52.40 & 12.99 & 26.68 & & \(\Delta\)L & **\(\Delta\)C** & **\(\Delta\)E** \\ \cline{2-7}  & SCE & 52.30 & 13.03 & 26.75 & SCI & 1.25 & 4.47 & 4.65 \\ \hline \multirow{2}{*}{**Regalrez 1126**} & SCI & 53.65 & 15.42 & 30.43 & SCE & 1.26 & 4.45 & 4.63 \\ \cline{2-7}  & SCE & 53.55 & 15.46 & 30.49 & & & & \\ \hline \hline \end{tabular}
\end{table}