Detailed kinetic observation revealing the formation mechanism of chiral mesoporous silica (CMS) synthesized by cooperative self-assembly of anionic chiral surfactant

• Formation process of chiral mesoporous silica (CMS) was investigated.
• Helical cylindrical micelles were formed first.
• Ionization of the NH2 of APS by COO− of C14AlaA is very important in the CMS formation.
• Such electrostatic interactions draw silica closer to the micelles and polycondensed.
• CMS with high thermal stability were obtained after 20 h of heating.

The synthesis of chiral mesoporous silica (CMS) is desirable for emerging applications, particularly in enantioselective catalysis. However, the detailed evolution during the CMS formation templated by self-assembly of chiral surfactants have not been clearly explained. In this study, we reported the evolutional formation of CMS which was understood by complementary analyses involving advanced techniques such as spectroscopy, microscopy and thermogravimetry. The samples were kinetically studied starting from the time intervals during precursors mixing until fully well-ordered CMS was obtained. Insignificant interactions between C14AlaA and APS were observed at the initiate state and the interaction was becoming crucial for the CMS formation. Additionally, we also speculated that the electrostatic interaction between NH2 group and COO− anionic head group on the micelle surface is the driving force for the CMS formation.

Figure optionsDownload as PowerPoint slide