Effects of transparent inorganic pigment on spectral properties of spectrum-fingerprint anti-counterfeiting fiber containing rare earths

Transparent inorganic pigment is the color-filler material for manufacturing spectrum-fingerprint anti-counterfeiting fiber, and has great effects on the emission spectral characteristics of the fiber. In order to explain the change mechanism of the emission spectral characteristics of spectrum-fingerprint anti-counterfeiting fiber and to promote the development of the fiber, several kinds of spectrum-fingerprint fiber samples were prepared by using rare-earth strontium aluminate and polyethylene terephthalate (PET) as raw materials and by adding different kinds of transparent inorganic pigments respectively in this research. The effect of transparent inorganic pigment on the spectral characteristics of the fiber was analyzed in detail by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and fluorescence spectrometer. The results showed that transparent inorganic pigment had no effect on the dispersion state and phase structure of rare-earth luminescent material in spectrum-fingerprint fiber and the microscopic morphology of the fiber. However, transparent inorganic pigment did affect the excitation and emission process of spectrum-fingerprint fiber so as to decrease its excitation and emission efficiency. The change of both the type and content of transparent inorganic pigment exerted great effects on the excitation and emission spectra of the fiber. Therefore, it was a feasible way to control the emission spectrum of spectrum-fingerprint fiber through changing the type and content of transparent inorganic pigment.