CN-121975513-A - Bio-based rare earth circularly polarized luminescent material and application thereof

Abstract

The invention discloses a biological-based rare earth circularly polarized luminescent material and application thereof, wherein the material is prepared by mixing cellulose nanocrystals with inorganic rare earth salt, so as to prepare a mixture with the weight of the inorganic rare earth salt and the solid mass of the cellulose nanocrystals of 0.4-0.6%, and then drying, wherein the rare earth element in the inorganic rare earth salt is selected from at least one of Tb or Eu. The emission half-peak width of the material obtained by the invention is far smaller than that of the traditional fluorescent material (< 5 nm) and realizes the light-emitting asymmetry factor of up to-0.26, rare earth ions can be directly doped, the preparation process is simpler and more convenient, the performance of the material is ensured, the doping concentration, the rare earth cation type and the anion type can be simultaneously changed, the light-emitting (intensity and color) and circular polarization properties can be finely regulated and controlled, and finally, the ligand belongs to a biological base material, thereby being beneficial to green chemistry and being more suitable for practical application environments.

Inventors

• WU YUE
• WANG ZEPENG
• WANG QIANNAN
• HE JINGJING
• ZHU WEIHONG

Assignees

• 深圳大学

Dates

Publication Date

20260505

Application Date

20260112

Claims (9)

1. 1. The biological base rare earth circular polarization luminescent material is characterized by being prepared by the following steps: Mixing cellulose nanocrystals with inorganic rare earth salt, thus preparing a mixture with the weight of the inorganic rare earth salt and the mass of the cellulose nanocrystals being 0.4-0.6%, and then drying to obtain the bio-based rare earth circularly polarized luminescent material; Wherein the rare earth element in the inorganic rare earth salt is selected from at least one of Tb or Eu.
2. 2. The bio-based rare earth circularly polarized light emitting material of claim 1, wherein the anionic portion of the inorganic rare earth salt is selected from at least one of chloride, sulfate or nitrate ions.
3. 3. The biobased rare earth circularly polarized light emitting material of claim 1 or 2, wherein the inorganic rare earth salt is selected from any one of europium chloride, terbium chloride or europium nitrate.
4. 4. The bio-based rare earth circularly polarized light emitting material according to claim 1, wherein the cellulose nanocrystals are rod-shaped nanomaterials having a diameter of 10-50 nm and a length of 100-600 nm.
5. 5. The bio-based rare earth circularly polarized light emitting material of claim 1, wherein the surface functional group of the cellulose nanocrystal is a carboxyl group or a sulfonic group.
6. 6. The bio-based rare earth circularly polarized light emitting material of claim 1, wherein the mixing time of the cellulose nanocrystals and the inorganic rare earth salt is 0.5-24 h.
7. 7. The bio-based rare earth circularly polarized light emitting material of claim 1, wherein the drying temperature is 15-60 o C.
8. 8. The bio-based rare earth circularly polarized light emitting material as claimed in claim 1, wherein the circularly polarized light emitting asymmetry factor of the material is 0.10 or more and the full width at half maximum (FWHM) of the emission spectrum is less than 5 nm.
9. 9. Use of a bio-based rare earth circularly polarized luminescent material as claimed in any one of claims 1-8 for the preparation of a three-dimensional display, anti-counterfeiting technology or biospecific recognition material.

Description

Bio-based rare earth circularly polarized luminescent material and application thereof Technical Field The invention belongs to the field of circularly polarized materials, and particularly relates to a bio-based rare earth circularly polarized luminescent material and application thereof. Background Circularly polarized luminescence (Circularly polarized luminescence, CPL) refers to the excitation of luminescent materials to emit different intensities of left-handed and right-handed circularly polarized light, depending on the intrinsic chirality and luminescent properties of the material. Based on this, a circularly polarized light emission index, i.e., an asymmetry factor g lum value, is defined and widely used: . By virtue of the unique left-right circularly polarized light emission difference, the CPL material has great application potential in numerous front fields, and is widely applied to three-dimensional display with high contrast imaging capability, anti-counterfeiting technology with higher safety performance, specific identification in biological fields and the like. Although CPL materials show wide application prospects, further commercialization and integration of high-performance optoelectronic devices are still subject to two core bottlenecks, namely low luminescence asymmetry factor (g lum value) and insufficient color purity. Currently, most reported chiral small organic molecules and polymeric materials have g lum values that are predominantly distributed on the order of 10 -3—10-2. This value is still too low for practical applications, severely limiting the photoelectric conversion efficiency and signal transmission quality of the device. Second, color purity is another important parameter for evaluating the quality of a luminescent material, and is generally measured by full width at half maximum (FWHM) of a luminescent peak. In most organic circularly polarized materials, there is a vibrational coupling between the ground and excited states, which results in a broadening of the luminescence peak (full width at half maximum FWHM, > 60 nm). The broadband emission not only reduces the color purity of the luminescence, but also disperses photon energy, which is not beneficial to the construction of high-energy-efficiency devices, and is difficult to meet the requirement of high-definition display on high color gamut. To break through the limitations, researchers have focused on rare earth complex materials. Because the 4f orbit transition in the rare earth complex material is shielded by the outer layer, the related material with narrow-band high-color purity emission can be obtained, however, the disadvantages of low coordination energy barrier and easy racemization of the rare earth complex material lead to the extremely easy quenching of circular polarized luminescence. To overcome this defect and induce strong CPL signals, excellent luminescent asymmetry factors are typically conferred to rare earth materials by fine tuning the chemical structure of the ligand and its coordination geometry with the rare earth ions. In searching for highly efficient chiral ligands, bio-based Materials (Bio-based Materials) stand out by their unique advantages. Natural biological molecules (such as amino acids, proteins, polysaccharides, DNA, etc.) are not only widely available and have good environmental friendliness and biocompatibility, but more importantly, possess highly ordered intrinsic chiral structures and rich coordination sites (such as carboxyl, hydroxyl, amino, etc.). For example, CN120535794A discloses a cellulose nanocrystalline composite film with circular polarization luminescence characteristic and a preparation method thereof, and the method specifically comprises the following steps of step 1, synthesizing europium macromolecules, and step 2, preparing a coated circular polarization luminescence cellulose composite film according to the product obtained in step 1. However, the preparation process of the method uses a large amount of organic reagents, has great environmental hazard, and the asymmetry factor |g lum | is only 0.12. Therefore, there is a need to develop an assembly and coordination method that is environmentally friendly, and also to obtain a high quality circularly polarized light emitting material with high asymmetry, high color purity, and environmental friendliness. Disclosure of Invention The invention aims to overcome at least one defect of the prior art and provides a bio-based rare earth circularly polarized luminescent material and application thereof The technical scheme adopted by the invention is as follows: In a first aspect, the invention provides a bio-based rare earth circularly polarized luminescent material, which is prepared by the following method: Mixing cellulose nanocrystals with inorganic rare earth salt, thus preparing a mixture with the weight of the inorganic rare earth salt and the solid mass of the cellulose nanocrystals being 0.4-0.6%, and