# Influence of Synthesis Parameters in Obtaining KIT-6 Mesoporous Material
## 3 Results and Discussions
Considering this study and the results obtained in the present work, it has been shown that the type of alcohol is an important parameter for the generation of the _la3d_ cubic structure. Due to the small size of the carbonic chains (methanol, ethanol and propanol), the interaction of the steric forces exerted by these alcohols in the micelle is possibly reduced. In this case, the smaller carbon chains are probably not enough to promote the posterior curvature of channels, resulting in unidirectional channels typical of SBA-15 materials. An opposite behavior was observed when increasing the size of the carbonic chain (KPe sample). The data probably suggest that pentanol alcohol provides an excessive interaction between the micelles to the point of promotion of the collapse of the structure. Figure 3C shows a representative scheme as a proposal of the influence of the variation on the type of alcohol in the formation mechanism of the KIT-6 material. The modifications on the aging time of the synthesis gel showed that, with the increase of time, the formation of the cubic structure is favored. This behavior reveals that 6 h (KAT6 sample) is inadequate to the formation of any organized structure. This fact can be related to the low rate of hydrolysis and posterior condensation of the silica groups. From 12 h (KAT12 sample) of aging time the formation of a material with hexagonal phase and unidirectional channels like the SBA-15 material was noticed. This fact corroborates the results described by [PERSON] et al. [30], where the authors observed the formation of a unidirectional phase with low synthesis time, which preceded the cubic phase. In addition to the present discussion, some studies showed that the change in synthesis parameters could cause a transition from the hexagonal to the cubic phase, and later to a lamellar phase [31; 32]. Corroborating these studies, this study demonstrated that the X-ray diffraction behavior at longer aging times, such as 18 h and 30 h (KAT18 and KAT 30 samples), provided the formation of the _la3d_ cubic structure characteristic of KIT-6 material. This case reveals that the \"organic-inorganic\" agglomerate obtained by the deposition of silicate species over the co-polymer needs periods longer than 18 h to go from a two-dimensional hexagonal organization with one-directional channels to a cubic three-dimensional phase with curved channels. Another relevant discussion refers to the curvature of the bi-continuous channels of the KIT-6 material. This indicates that the adequate time for there to be interaction forces exercised by the alcohol in the P123 micelles is between 12 h and 18 h of aging time in the synthesis gel. Considering this fact, even when using the standard alcohol for all the syntheses of this modification stage, only with times higher than 18 h can the desired _la3d_ cubic structure be obtained (see scheme in Figure 3D). The results of the variation on the thermal treatment time of synthesis gel show that all of the materials of this modification stage (KHT12, KHT18 and KHT30 samples) had structure typical of KIT-6, XRD peaks that were very similar to the standard sample. This fact indicates that all of the formation stages and structural organization of the cubic phase are probably found in the earlier stages of the synthesis mechanism. Thus, it is possible to obtain a high degree of condensation of the Si-OH groups and later formation of Si-O-Si bonds without any significant interference in the material'sstructure with a reduction of up to 12 h of the standard time. It should be noted that modifications performed in this parameter of the synthesis demonstrated greater influence on the textural properties (discussions performed posteriorly). By the XRD data, the interplanar distance (d\({}_{(211)}\) and d\({}_{(100)}\)), and the mesoporous parameters (a\({}_{\text{cub}}\) and a\({}_{\text{hex}}\)), for cubic and hexagonal structures, respectively, could also be determined. Table 1 exhibit these values for all the samples.