Synthesis of chiral mesoporous silica by using chiral anionic surfactants

Recently, the use of a chiral anionic surfactant derived from amino acid, N-myristoyl-l-alanine sodium salt, has enabled us to obtain a chiral mesoporous silica. In this study, chiral mesoporous silicas with helical particles were successfully synthesized by using the chiral anionic surfactants N-miristoyl-d-alanine as well as N-miristoyl-l-alanine. The left-/right-handed ratios for the helical particles synthesized with C14-l-AlaA and C14-d-AlaA proved to be 75/25 and 25/75, respectively, suggesting that the predominant handedness of helices was directed by the handedness of the surfactants. The optimization of the synthesis conditions for obtaining a chiral mesoporous silica were conducted. We found that the macroscopic morphology as well as the mesostructure of the chiral mesoporous silica was extremely sensitive to the synthetic conditions. The influence of the stereoisomerism of the chiral surfactant on the mesostructure and morphology of chiral AMS was investigated by using a mixture of C14-l-AlaA and C14-d-AlaA.