Preparation of silica/polymer nanocomposites with aggregation-induced emission properties as fluorescent responsive coatings

Abstract

Fluorescent materials in the recent past have found numerous novel applications in various fields such as medicine, environment, electronics and coatings. For smart coating applications, durability, responsiveness and repeatable functionalities are desirable especially in their solid state. However, due to the known aggregation-caused quench (ACQ) effect, many traditional fluorescent molecules’ intensity tends to diminish at aggregated state. This ultimately affects the traditional fluorescent materials’ use in these applications. To develop smart coatings with suitable properties and responsiveness, herein, a novel aggregation-induced emission (AIE)-based composite fluorescent latex was prepared and systematically studied. Briefly, the approach involved first grafting tetraphenylethene (TPE) derivant onto the silica sol. The resultant modified silica sol could then emit strong fluorescent light courtesy of TPE’s restricted intramolecular rotation. Further, the modified silica sol was used as the surface to emulsion polymerize acrylic latex, forming a fluorescent composite core-shell structure. As a smart and responsive fluorescent composite coating, when cured, it showed fluorescent responsiveness to the external stimuli, such as water and toluene vapor, demonstrating possible application in smart paints.