ACQ effect in fluorescent materials

The aggregation caused quench (ACQ) effect in traditional fluorescent molecules can lead to a significant fluorescent intensity decrease of fluorescent-based materials during aggregation or at solid state, which apparently limits their application. To overcome this effect, in a recently published paper, a series of water-based fluorescent paints doped with rhodamine B were synthesised and systematically characterised using photoluminescence (PL) spectrum and other analytical methods.

Real-time monitoring according to PL spectrum

Rhodamine B was employed because it can be adsorbed onto the shell of latex by ionic attraction force during emulsion polymerisation, and hence its aggregation trends can be inhibited, thus emitting fluorescent light effectively. To explore this phenomenon, a series of characterisations were employed. Firstly, the different emulsion polymerisation processes, such as cationic emulsion polymerisation and anionic emulsion polymerisation of the systems were studied with real-time monitoring according to PL spectrum.

Environment-friendly smart coatings

Secondly, the factors that affect the luminescence behavior of the fluorescent latexes were studied systematically by varying the different conditions, such as the dispersing forms of rhodamine B, the concentration of rhodamine B and the latex particles, the size, and glass transition temperature of latex particles. Lastly, the relationship between the fluorescence property of the cured fluorescent latex and the testing temperatures were also studied. The research findings herein not only reports a way to inhibit the ACQ effect of traditional fluorescent molecules, but also are predicted to be beneficial to the development of the environment-friendly smart coatings.

The study is published in: Progress in Organic Coatings Volume 120, July 2018, Pages 1-9.