Polyphenols as morphogenetic agents for the controlled synthesis of mesoporous silica nanoparticles

Non-surfactant-induced synthesis of mesoporous silica nanoparticles (MSNP) are gaining increasing interest owing to their low toxicity and simple purification compared to conventional surfactant-based methods. Tannic acid (TA), con-sidered as a glucose-derived polyphenol, was first employed a few years ago and has attracted great research interest. Despite recent progress, the mechanisms resulting in the porous structure remain to be elucidated. In this work, we have employed TA and four structurally related polyphenols (gallic acid, ethyl gallate, eudesmic acid and quercetin) to elucidate the effect of the chemical structure and properties of polyphenols on their templating ability. Our results unravel the mechanism of MSNP formation templated by TA, which form a supramolecular framework as skeleton for the silica species to attach. The structure of the supramolecular network results in irregular pores. Additionally, the pKa value of the templates may be accounted for the particle size. Small angle X-ray...