Research On The Preparation And Application Of Temperature-sensitive Fluorescent Materials

Quantum dots(QD),also known as fluorescent semiconductor nanocrystals,have unique electronic and optical characteristics,and have been used as a security material in film materials,security inks and other security fields.Existing anti-counterfeiting research of fluorescent semiconductor nanomaterials is through the fiber-composite composite material to emit light under excitation,or the doping ratio of a fluorescent material and lanthanide is used to change the luminous intensity by adjusting the doping ratio.Broadening the application fields of quantum dots in fluorescence anti-counterfeiting and the detection methods in application fields have become the main research directions at present.In this paper,a temperature-sensitive fluorescent light-emitting fluorescent system was prepared.By mixing graphene quantum dots(GQDs)with gold nanoclusters(Au NCs)whichi has temperature-sensitive fluorescence properties to form a mixed system,Au NCs have strong fluorescence at low temperatures,and the fluorescence intensity gradually decreases with increasing temperature,while GQDs The fluorescence intensity is almost unchanged,thereby achieving the purpose of temperature-sensitive fluorescence discoloration of the system.citric acid was used as the carbon source,and GQDs with high fluorescence quantum yield were prepared by a combination of pyrolysis and hydrothermal method.Au NCs were prepared with chloroauric acid as the gold source and glutathione as the reducing agent and stabilizer.The optimal reaction conditions were obtained by optimizing the respective reaction conditions.X-ray powder diffractometer,X-ray photoelectron spectrometer,transmission electron microscope,ultraviolet-visible spectrophotometer,infrared spectrum absorption spectrometer,and fluorescence spectrophotometer were used to characterize the morphology and fluorescence of the product.The results show that we prepared: GQDs with an average size of 9.72 nm and blue-green fluorescence,excitation and emission wavelengths of 365 nm and 467 nm,and an average size of 2.25 nm and orange-red fluorescence,excitation and emission wavelengths of 420 nm and 620 nm,respectively.GQDs-Au NCs were prepared by mixing Au Qs with GQDs and Au NCs at a volume ratio of 1: 19.The cyanine pigments that emit light under ultraviolet light irradiation was obtained by that GQDs,Au NCs,and GQDs-Au NCs mixed with traditional Chinese painting pigment cyanine.Using Origin software to analyzed the infrared absorption spectrum of pigment cyanine and the connection between the characteristic peak area.and then pigments was been confirmed by the fixed area ratio of characteristic asorption peak fitting.