Aggregates of cholic acid and benzylamine as templates for the formation of hollow silica spheres

Excerpt

Silica is an abundant and important biomineral in one-celled diatoms through to higher animals and plants. Due to its amorphous structure, silica morphogenesis principally depends upon the suitable templates [1‐6]. It is well known that the sufficient interaction between the aggregates and negatively charged silica precursors, such as tetraethyl orthosilicate (TEOS), is indispensable for effective transcription [7‐9]. Thus, silica transcription via TEOS polycondensation was limited to molecules possessing positive charges or hydrogen bond sites, like amino groups, until people discovered the utilization of amine additives to promote the silica transcription even in the absence of cationic groups or hydrogen bond sites on the aggregates [10‐14]. The self-assembly morphologies of poly(l-lysine) vesicles [10] and organogel fibers [11] have been successfully transcribed into their silica analogs with the help of benzylamine. As a result, a great amount of organic molecules, including anionic and neutral molecules, can be considered as templates for silica transcription. …