Deep Processing of Pluronics: Production of Surface-Active Carbon Dots and Application in Photoluminescent Soft Materials

Abstract

Poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers, with trademark of Pluronics, are an important class of nonionic, macromolecular surfactants. In this work, deep processing of Pluronics was tried through pyrolysis of citric acid (CA) in Pluronics, leading to the formation of blue-emitting, surface-active carbon dots (sa-CDs) where the PEO-PPO-PEO chains are covalently attached to the carbonized CA. Production of sa-CDs is successful for all three Pluronics including F127, F68 and P123. The sa-CDs could be produced facilely and massively. Specifically in the case of F127, the surface activity becomes stronger after deep processing. The sa-CDs were used as the photoluminescent component to construct microemulsions using liquid flavor or essential oils extracted from plants as the oil phase. The controlled release of the liquid flavor or essential oil in the microemulsions provides opportunities of formula modulation towards applications in food and cosmetics. By further introducing chiral molecules to the system, circularly polarized luminescence was achieved, which opens the door for applications in photonic devices.

Keywords: surface active, carbon dots, Pluronic, microemulsion, circularly polarized luminescence