Modified supercritical CO2 extraction of amine template from hexagonal mesoporous silica (HMS) materials: Effects of template identity and matrix Al/Si molar ratio

- Matrix/template interactions become stronger as the Al/Si molar ratio increases.
- Extraction efficiency obtained is observed to decrease with the Al/Si molar ratio.
- Efficiency depends on the template chain length due to the formed matrix pore size.
- Formic acid modifier results in better extraction performance than methanol.
- SFE-treated HMS materials have higher acidity than the directly calcined samples.