New sight for in-situ monitoring of silica growth process: The incorporation of Stöber process and aggregation-induced emission (AIE) technique

A silane based AIE probe (APTS-TPE) was prepared through the incorporation of (3-Aminopropyl)triethoxysilane (APTS) and tetraphenylethylene (TPE), and applied for in-situ visual monitoring of the silica growth in Stöber process. The TPE groups in the APTS-TPE structure can be anchored in the -Si-O-Si- molecular network and exhibited strong fluorescence emission owing to the restriction of intramolecular motion of TPE group. Real-time in-situ particles size analysis and photoluminescence (PL) intensity analysis were carried out to follow the evolution of PL intensity with particle size. The relationship between silica size and PL intensity in parallel experiments were also discussed. Compared with traditional characterization methods, this method has the potential application for silica industrial production and fundamental research, with the advantage of sensitive, rapid and non-invasive.