Fig. 5 shows the correlations between the D4 capacities and the textural parameters of mesoporous aluminosilicates. The data in Fig. 5 have been fitted with both linear and parabolic equations. The fitted lines with highest R2 values are shown. Generally speaking, there are good correlations between the D4 adsorption capacities and BET surface area, total pore volume, external surface area, and mesopore volume. Viewed by the different Si:Al ratios among
the synthesized materials and ZSM-5, the aluminum as acid sites might also contribute to D4 adsorption to some extent. However, in this study, the role of Al in siloxane adsorption was not clear, as the change of the Si:Al ratios was correlated with the change of the textual properties of the materials, such as BET surface area, external surface area, mesopore volume and total pore volume.