Preparation of Graphene Quantum Dots Decorated Montmorillonite to Reinforce Fire Retardancy of Polystyrene

Abstract

Graphene quantum dots (GQDs) are unique zero-dimensional carbon materials that possess a graphene-like plane structure and are easy to be functionalized. GQDs can strongly attach to the basal plane via π–π stacking, which might be beneficial to improve the dispersion in the polystyrene (PS) matrix. In this study, montmorillonite (MMT) was decorated with graphene quantum dots to create nanohybrids, which were then incorporated into a PS matrix via a simple solvent blending-precipitation method. The resulted nanohybrids were uniformly dispersed in the polymer matrix and demonstrated enhanced interfacial interaction between nanoadditives and PS. After the addition of nanohybrids, the flame retardancy of the PS nanocomposites was significantly increased, which can be attributed to the physical barrier effect. Furthermore, the storage modulus of the nanocomposites with nanohybrids was further enhanced compared to that with MMT alone. This work proposes a novel method to modify MMT and produce well-dispersed polymeric materials with enhanced fire safety. Furthermore, this feasible and effective decoration method offers possibilities for broadening the applications of MMT, and it could also be extended to modify other clay materials with different functional groups for various applications.