Research On The Security Technology Of Down Fiber Loaded With Characteristic Rare Earth Ions

Down a fiber is a kind of protein fiber with a fluffy and soft structure.It has an excellent thermal insulation properties and plays a vital role in the production and application of cold-resistant textiles.However,more and more bad down and their products enter the market,which seriously blocks the progress of down textile brand development in national.Rare earth fluorescent materials are widely used in the field of material identification and anti-counterfeiting due to their high chemical stability,excellent optical stability,narrow emission band and long luminescence life.Especially,the double invisibility of excitation and emission of rare earth down conversion luminescent materials in the infrared band greatly improves the confidentiality of the protected products,which is recognized as one of the safest state-of-the-art anti-counterfeiting technologies at present.In this paper,the characteristic infrared spectrum of ytterbium ions(Yb³⁺)is used as the core technology of anti-counterfeiting,and the nanoparticle NaYF₄:Yb³⁺with special infrared emission is prepared by complexation precipitation method.On this basis,the nanoparticle NaYF₄:Yb³⁺was modified to obtain the ability of combination with down fibers.Furthermore,verifiable down with infrared excitation-infrared emission was prepared,which realize the certification of natural down fibers.The main research contents and conclusions are as follows:Nanoparticles with infrared emission NaYF₄:Yb³⁺were prepared by complexation precipitation method in which the benzoic acid was used as a complexing agent.The elemental composition,phase structure,surface micro-morphology,near infrared absorption spectrum,emission spectrum and the mechanism of fluorescence emission is conducted by FTIR,X-ray diffractometer?XRD?,transmission electron microscope?TEM?,absorption and emission spectra.The characterization results that sodium benzoate is only used as a complexing agent in the preparation,and the average particle size of nanoparticle?-NaYF₄:Yb³⁺is 86 nm.The absorption and emission spectra of the nanoparticles show that NaYF₄:Yb³⁺has an invisible infrared emission of 930?1080 nm(corresponding to the²F_7/2?²F_5/2/2 transition in Yb³⁺)under the excitation of 900 nm light.Under the excitation of980 nm light,it has a blue visible emission of 475 nm(assigned to cooperative de-excitation of Yb³⁺-Yb³⁺pairs).When the doping concentration of Yb³⁺is 5%and 20%,the infrared and blue emission intensities maximizing,respectively.NaYF₄:Yb³⁺nanoparticles with a Yb³⁺doping concentration of 5%were modified to be grafted sulfonic acid groups?-SO3?on their surface to obtain the ability of combination with down fibers.The security particles SO₃-SiO₂@NaYF₄:Yb³⁺were prepared by modification of?-mercaptotrimethylsiloxane?MPTES?.The phase structure and chemical composition of the product in the preparation process were characterized by TEM,FTIR,XRD,XPS and emission spectra.Experimental results show that the layer on the surface of nanoparticles NaYF₄:Yb³⁺was thickening with the increase of MPTES.When the volume of MPTES reaches 1.5 mL,the increase thickening of the coating is not obvious.The FTIR and XPS spectra of the products show that thiohydro group on the surface of the nanoparticles is oxidized in situ to sulfonic group by acetic acid-hydrogen peroxide.The security particles SO₃-SiO₂@NaYF₄:Yb³⁺reradiated a similar infrared emission?930?1080 nm?to nanoparticles NaYF₄:Yb³⁺under the excitation of 900 nm light,and the emission intensity of security particles is obviously improved due to the reduction of defects.The grease on the surface of down fiber was removed with AEO as detergent,and then the anti-counterfeiting down was prepared after finishing.The effect of the temperature of the finishing solution and the concentration of security particles on the load of security particles particles to down was researched in the single factor analysis method.The surface properties,element composition,surface micro-topography,near infrared emission spectrum of the anti-counterfeiting fiber are measured by static water contact angle test,Zeta potential meter,FTIR,SEM and emission spectrum.Experimental results show that:The pretreatment of AEO washing at 60?for more than 60 min effectively improves the hydrophilicity of the down fiber;the Zeta potential value of the security particles and down fiber in the test solution decreases with the pH value rising,and the chargeability gradually turn from positive to negative.When pH=3,the charge difference between the security particles and the down fibers is large and the binding force is strong.When the finishing temperature is 60?and the concentration of the security particles in the finishing solution is 1.5 g/L,the loading effect of security particles on the the anti-counterfeiting down is significant.The results of water washing test show that they have certain binding fastness.The anti-counterfeiting down also launched 930?1060 nm wide-spectrum infrared emission under excited of 900 nm near-infrared light.Finally,the infrared anti-counterfeiting technology and related hardware of anti-counterfeiting down were designed.The multi-level anti-counterfeiting method composed of rare earth ions is put forward further.