# Influence of Synthesis Parameters in Obtaining KIT-6 Mesoporous Material
## 3 Results and Discussions
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Samples** & \(\mathbf{W_{BJH}/nm}\) & \(\mathbf{W_{VBS}/nm}\) & \(\mathbf{W_{NLDFT}/nm}\) & \(\mathbf{W_{VBS}/nm}\) & \\ \hline  & & **Adsorption** & & **Desorption** & \\ \hline KIT-6 & 7.2 & 6.8 & 9.6 & 7.0 & 5.8 \\ K0.012 & 6.8 & 7.0 & 9.1 & 6.6 & 6.9 \\ K0.022 & 6.6 & 6.8 & 8.7 & 6.7 & 5.7 \\ KDT2 & 6.7 & 6.8 & 9.1 & 6.6 & 6.1 \\ KDT4 & 6.9 & 7.0 & 9.2 & 6.5 & 4.6 \\ KDT8 & 7.2 & 7.2 & 9.6 & 7.2 & 5.4 \\ Kdt & 6.5 & 6.7 & 8.7 & 6.5 & 6.2 \\ KE & 6.8 & 7.0 & 9.1 & 6.7 & 6.5 \\ KPr & 6.5 & 6.7 & 8.9 & 6.7 & 5.0 \\ KAT12 & 6.7 & 6.7 & 8.3 & 6.6 & 5.7 \\ KAT18 & 6.9 & 7.3 & 8.2 & 7.5 & 5.2 \\ KAT30 & 6.0 & 7.5 & 8.2 & 7.3 & 5.6 \\ KHT12 & 6.1 & 6.5 & 8.2 & 6.6 & 5.9 \\ KHT18 & 6.2 & 6.6 & 8.3 & 6.8 & 5.8 \\ KHT30 & 7.0 & 6.9 & 9.0 & 7.0 & 5.6 \\ \hline \end{tabular} \(\mathrm{W_{BJH}}=\) pore diameter using the BJH method. \(\mathrm{W_{NLDFT}}=\) pore diameter using the NLDFT method. \(\mathrm{W_{VBS}}=\) pore diameter using the VBS method. \(\mathrm{W_{T}}=\) wall thickness calculated from: \(\mathrm{a_{Cub}}-\mathrm{W_{VBS}}\) (cubic structures) and \(\mathrm{a_{Hex}}-\mathrm{W_{VBS}}\) (hexagonal structures).  
\end{table} 
Table 4: Average values of pore diameter through the Barrett-Joyner–Halanda (BJH), Villarroel–Bezerra–Sapag (VBS) and non-local density functional theory (NLDFT) techniques of all samples with ordered structures. adding a correction term to the original Kelvin equation, providing more accurate values for the pore size. Taking this into account, all discussion about the PSD and average pore diameter were carried out based on the VBS method applied in the desorption branch. This is because, according to the authors [24; 44], the desorption branch reflects the transition of the equilibrium phase, which supports the macroscopic methods that use the Kelvin equation. From the data of the K0.012 and K0.022 samples obtained, there can be seen a similarity in the values of pore diameter when compared to the standard KIT-6. Such a fact demonstrates that the variation of the amount of organic template did not influence in an expressive way the pore size of the materials. However, when analyzing the values of wall thickness, a difference of 1.1 nm between the K0.012 sample and the standard KIT-6 can be noted. This difference is directly related to the values of cubic parameters observed (see Table 2). In consequence, such behavior is reflected in the wall thickness. Thus, the wall thickness values contribute to the explanation of the synthesis mechanism and the specific area values for such materials, as cited previously. Evaluating the dissolution time for the materials with 3D cubic structures, the KDT4 and KDT8 samples showed proportional differences for pore diameter, when compared to the standard KIT-6. The values of pore diameter exhibited a difference of 0.4 nm (values of 6.5, 6.9 and 7.3 nm) between the KDT4, KIT-6 and KDT8 samples, respectively. This behavior indicates an increase in the average pore size in function of the dissolution time of the organic template. Analyzing the values of wall thickness, it denotes a significant decrease of 1.2 nm on the KDT4 sample, when compared to the standard KIT-6. This data correlates the values observed for the cubic parameter (a\({}_{\text{cub}}\)) and, in consequence, specific area (S\({}_{\text{BET}}\)), corroborating with the synthesis mechanism cited. The KDT8 sample was compared with the standard KIT-6 and it is worth mentioning that, despite the values of wall thickness being similar, the KDT8 sample demonstrated superior textural properties (specific area, mesoporous volume, total volume and pore diameter) with the addition of 2 h in the synthesis process. Evaluating the pore diameter data for the KMT, KEt and KPr materials with hexagonal structure, this shows very similar behavior for each one. On the other hand, a very irregular behavior was seen when comparing the data obtained for wall thickness of these materials.