# Halloysite and Laponite Hybrid Pigments Synthesis with Copper Chlorophyll
## 3 Results and Discussion
### Chlorophylll Adsorption  
All the supernatants separated after the centrifugation step were measured to find the presence of natural colorants to calculate synthesis performance as the percentage of dye adsorbed in both nanoclays (Ads(%)) (Table 2). Significant differences were found depending on the synthesis conditions. The analysis of variance revealed that the significant factors in the percentage of dye adsorbed in both nanoclays (Ads(%)) were the mordant and pH interactions (see Table 3). The p-values in both factors were lower than 0.05. According to Figure 3, when mordant salt was present (MORD = 1.0), no differences appeared due to the pH level (from \(-\)1.0 to 1.0), and the supernatant was clear and dye adsorption was maximum (\(\approx\)99%) in both structures. However, when no mordant salt was present (MORD= \(-\)1.0), pH became a critical factor and had to be acidic (pH = \(-\)1.0 (3-4)) to maintain dye adsorption close to 99% in both nanoclay structures. The lowest adsorption percentage (\(\approx\)84%) was found at a natural pH (pH = 1.0 (9-7)) with no mordant salt present (MORD= \(-\)1.0). Based on these results, the mordant-modified solvent ion strengthened and favored the chlorophyll-clay interaction similarly to the textile dying process. In the halloysite structures, the protonation constants increased accordingly to ionic strength, which favored the chlorophyll interactions. At a low pH, halloysite layers were protonated from pH 2 to pH 6.5, the silicic surface underwent deprotonation, and its lowest possible negative charge was reached at the highest point of the range. Depending on the nanoclay layer, both ionic strength and pH changed protonation and favored H \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Sample Code** & **pH 1** & **SURF 2** & **MORD 2** & **SIL 2** \\ \hline GLAP.1 & 4 & 0 & 0 & 0 \\ GLAP.2 & 9 & 0 & 0 & 2 \\ GLAP.3 & 4 & 2 & 0 & 2 \\ GLAP.4 & 9 & 2 & 0 & 0 \\ GLAP.5 & 4 & 0 & 2 & 2 \\ GLAP.6 & 9 & 0 & 2 & 0 \\ GLAP.7 & 4 & 2 & 2 & 0 \\ GLAP.8 & 9 & 2 & 2 & 2 \\ GHA.1 & 4 & 0 & 0 & 0 \\ GHA.2 & 9 & 0 & 0 & 2 \\ GHA.3 & 4 & 2 & 0 & 2 \\ GHA.4 & 9 & 2 & 0 & 0 \\ GHA.5 & 4 & 0 & 2 & 2 \\ GHA.3 & 9 & 0 & 2 & 0 \\ GHA.3 & 4 & 2 & 2 & 0 \\ GHA.8 & 9 & 2 & 2 & 2 \\ \hline \hline \end{tabular} \({}^{\dagger}\) Nanoclay in water dispersion pH. 2 Modifier concentration % over nanoclay mass.  
\end{table} 
Table 1: Synthesis condition analysis using the 2\({}^{4-1}\) DoE experiment and two experimental blocs; 1-laponite, 2-halloysite, and dispersion pH, surfactant (SURF), mordant (MORD), and/or silane (SIL) factors. bonding. The aluminic layer was protonated up to pH 6 and then its deprotonation process was affected by ionic strength. The presence of H\({}^{+}\) in the W-SiO-H system did not allow water molecules to interact with the inner halloysite layer. The preferred protonated site in the acidic chemical environment was the aluminic surface, which was slightly stabler than its silicic counterpart. In addition, the formation of H\({}^{3}\)O\({}^{+}\) species on the positively charged silicic layer made the systems in which it was present much stabler than their analogous version on the aluminic layer [36]. \begin{table}
\begin{tabular}{c c c} \hline
**REF** & **Abs \(\lambda\) (405.4 nm)** & **Abs (\%)** \\ \hline GLAP.1 & 0.1267876 & 97.91 \\ GLAP.2 & 0.4166450 & 80.21 \\ GLAP.3 & 0.1168471 & 98.51 \\ GLAP.4 & 0.1445317 & 96.82 \\ GLAP.5 & 0.1220899 & 98.19 \\ GLAP.6 & 0.1101210 & 98.92 \\ GLAP.7 & 0.1197555 & 98.34 \\ GLAP.8 & 0.1242313 & 98.06 \\ CHA.1 & 0.1197628 & 98.34 \\ CHA.2 & 0.2486290 & 90.47 \\ CHA.3 & 0.1279232 & 97.84 \\ CHA.4 & 0.6237080 & 67.57 \\ CHA.5 & 0.1153758 & 98.60 \\ CHA.6 & 0.1140121 & 98.69 \\ CHA.7 & 0.1160737 & 98.56 \\ CHA.8 & 0.1136496 & 98.71 \\ \hline \end{tabular}
\end{table} 
Table 2: The absorption (Ads (%)) results at \(\lambda\) 405.4 nm and the percentage of dye adsorbed under different synthesis conditions by the DoE 24\({}^{-1}\), calculation.