Novel AIE luminescent tetraphenylethene-doped poly (lactic acid) composites for fused deposition modeling and their application in fluorescent analysis of 3D printed products

Luminescent 3D printing materials have attracted many attentions due to their promising applications of luminescent inks, hydrogels and microstructures. However, no reports have shown the priority of their fluorescence for detection of the quality of 3D printing products. In this work, novel luminescent poly (lactic acid) (PLA) composite filaments with typical aggregation-induced emission (AIE) building block (tetraphenylethene, TPE) for 3D printing have been successfully developed, by simple solution premixing and melt extrusion methods. It was found that TPE uniformly dispersed in the PLA matrix and significantly increased the crystallinity of PLA, which not only maintained the good thermal property but also improved the mechanical properties of TPE/PLA composites. Notably, the composite filaments emitted ultra-bright blue light under UV lamp, and the fluorescence intensity increased as the content of TPE increased. Finally, several brightly luminescent exquisite articles could be manufactured by a single-nozzle 3D printer with these new fluorescent filaments. Most interestingly, a thin layer of 0.4 mm TPE/PLA was implanted in the strip-shaped specimens by a dual-nozzle printer, which could be used as a very sensitively fluorescent visual inspection of the quality of 3D printing products, including the degree of bending damage and their small defects. Therefore, the development of novel luminescent TPE/PLA composites combined with 3D printing technology in this work provides a unique opportunity for the design and application of luminescent 3D printing materials.