Tetraarylethene fluorescent dyes with aggregation-induced emission for LED-driven photocuring and 3D printing

Abstract

Four tetraarylethene-based fluorescent dyes (i.e., Cz-bi-Ph, Cz-hex-Ph, DHBF-Ph, and BP-Ph) with aggregation-induced emission (AIE) properties were synthesized. The fluorescence properties of the dyes in the liquid (solution) and solid states during the photocuring process were characterized. Their sensitizing activity to the photoinitiator in the LED-driven photocuring of acrylic monomer and epoxy resin was investigated. In the photocuring system initiated by photoinitiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), all the dyes showed good photostability and fluorescence enhancement within the irradiation period. Dyes can be used to successfully obtain solid-state fluorescent samples from digital light processing 3D printing that can be used as the fluorescent probe to monitor the photocuring process. The obtained tetraarylethene-based fluorescent dyes were found to have photosensitization properties for photoinitiator diaryliodonium salt (ONI) under a 405 nm LED and can initiate the curing of acrylate monomer and epoxy oligomer. In the photocuring system initiated by dye-sensitized ONI, Cz-bi-Ph and Cz-hex-Ph showed a strong photosensitization activity. The sensitization activities of DHBF-Ph and BP-Ph were relatively weak. However, the fluorescence of the corresponding systems, which can be used as both fluorescent probes and sensitizers, changed significantly with the photocuring process, and their fluorescence tended to be stable when the photocuring was completed.