Study On The Luminous Materials For Producing Luminous Fibers And The Photochromic Properties Of Luminous Fibers

Luminous fibers are a kind of new functional materials, produced with fiber matrixadded luminous materials and colored pigments. The luminous materials for producingluminous fibers are aluminate long afterglow luminous materials composed of rare-earthactivator, which have broad application prospects, because of the properties of high brightness,high internal quantum efficiencies, stable performance, and non-radiation. Luminous fibersproduced with the luminous materials have no harms on human body and the environment.The luminous fibers present colors in normal condition and produce color lights in darkness,which determine the application value of luminous fibers.In the paper, the photo chromicproperties and the effect factor of photo chromic mechanism of luminous fibers had beenstudied based on luminous materials and colored pigments.The main contents and conclusions of the dissertation were as follows:(1)The luminous materials SrAl2O4: Eu2+?Dy3+were prepared via a solid state reactionmethod. In order to ascertain the technics of luminous material for preparing luminous fibers,the morphology and optical properties of the obtained luminous materials were characterized,and the effect of calcinations temperature, the dosage of rare-earth activator and cosolvent onthe afterglow intensity were investigated. Experiment results showed that the luminousmaterials showed well-defined boundaries for each particle. The excitation spectra profile andthe emission spectra profile showed broad bands similarly with the peak of excitation spectraat360nm and emission spectra at520nm. With the calcinations temperature increasing, thecolor temperature, purity and afterglow intensity of luminous material decreases. Moreover,the color rending index increases. The afterglow intensity of luminous materials increasedwith the increase of activator and cosolvent addition firstly and began to cut down at a certainposition(2)Luminous fibers were prepared by melting spinning with Polymer-PA6addedluminous materials SrAl2O4: Eu2+?Dy3+and colored pigments. The luminescent process ofluminous fibers was simplistically analyzed by building the model of the cross-section shapeof luminous fibers, and then analyzed its morphology and optical properties. The resultsrevealed that when the excited light entered the fiber and propagated within it, the track of theexcited photons in the fiber affected by luminous materials and colored pigments to producedifferent color emission light which determined the emission colors of luminous fibers.Luminous fibers were uniform in diameter and spun yarn quality, and retained characteristicpeaks of PA6and luminous materials. The XRD and FT-IR spectrum indicated that colored pigments and luminous materials had little impacts on macromolecular structure of the PA6luminous fiber. After being irradiated with ultraviolet light, luminous fibers emitted longlasting yellow-green phosphorescence with an excitation peak at360nm and emission peak at520nm. However, the excitation spectrum of the PA6-Y exhibited a hump characteristic curvewith three peaks:360nm,450nm and470nm. The colored pigments weakened the afterglowintensity of luminous fiber.(3)Under colored pigments and luminous materials influence, there was a certaindeviation in the color and emissive color of luminous fibers, which affected human visualperception and feelings. By testing color properties and emissive light performance, this paperdiscussed the relationship between the color and emissive color. The results showed that thecolors of luminous fibers are similar to that of colored pigments, and the hues were greatdifferences between the colors. In darkness, emissive light of luminous fibers was mixed withyellow light and green light, and there was no obvious difference among the color and hues ofemissive light. The dominant wavelength of the colors was different from that of emissivecolors because of the addition of colored pigments.(4)Based on the experimental data of the emission spectra of the luminous fibers,chromaticity coordinates could be obtained by calculation. On the basis of human's visionmodel of compound light vision principle, the relationship between the equivalent afterglowintensity and the test afterglow intensity of luminous fibers with different angle of view wasanalyzed. The results showed that the equivalent afterglow intensity of luminous fibers wasclose to the test afterglow intensity at2degree field, and it was apparently different at10degree field.(5)The afterglow intensity of luminous fibers was tested under different conditions offiber matrix, exciting light, acid and alkali treatment, ultraviolet irradiation and washing. Theresults showed that the afterglow intensity of luminous fibers was strongly influenced by fibermatrix. The afterglow intensity of luminous fibers increased with the increase of bothexcitingillumination and exciting time, and reached the optimumunder an excitationillumination of1000lx for5minutes.In addition, acid and alkali treatment, ultravioletirradiation and washing had little influence on the afterglow intensity of luminous fibers.