Design, Preparation, and Mechanical Property Study of Polylactic Acid/Ca 2 BO 3 Cl: Eu 2+ , Dy 3+ Composite Material for 3D Printing.

To break through the simplification of three-dimensional printing (3DP) materials and realize the application of long-persistent phosphors in more fields, polylactic acid doped with Ca 2 BO 3 Cl: Eu 2+ , Dy 3+ was prepared in this study. The structure of the mixtures was analyzed and determined by infrared spectroscopy. The luminescence properties of phosphors and the composites were studied by fluorescence spectra and afterglow decay curve measurements. The yellow light of the mixtures could be attributed to the 5d-4f energy level transition of Eu 2+ . After the excitation of 254 nm ultraviolet lamp, the luminance and duration of the composites could be clearly observed. The mechanical properties of the composite filaments were tested, including maximal force and elasticity modulus. In particular, the influence of humidity on mechanical properties was analyzed in detail. The prepared composite filaments were printed into hollow dodecahedrons and presented in this study. Therefore, the composites had great properties and might be expected to put into practical applications of 3DP technology.