Optical waveguide material with photochromism and its application in information coding field

Abstract

The application discloses a light waveguide material with photochromism and application thereof in the field of information coding. A new type of metal-organic halide material is formed by self-assembly of benzimidazole organic matter and zinc chloride. The material has the following characteristics: (1) reversible photochromism; (2) smooth surface and highly ordered structure, and good fluorescence-phosphorescence dual-emission light waveguide characteristics, and the active light waveguide characteristics can be reflected before and after photochromism. The material not only has photochromism based on fluorescence-phosphorescence dual-emission, but also can effectively adjust the waveguide performance by photochromism, and realizes the application of the new type of waveguide material in the field of information coding.

Description

Technical Field

[0001] This invention belongs to the field of optical functional materials technology, specifically relating to a photochromic optical waveguide material and its application in the field of information encoding. Background Technology

[0002] Photochromic materials, due to their reversible color changes in appearance or fluorescence, are widely used in information storage and anti-counterfeiting fields. However, with the advent of the big data era, there is an urgent need for advanced information security and storage technologies. Traditional photosensitive materials are far from meeting the demands of the times. Notably, persistent luminescent materials with special time-resolved properties show fascinating promise in the field of information security, especially those with tunable emission characteristics. Therefore, if time-resolved photochromic materials can be developed, it will bring new opportunities to the fields of information security and information storage.

[0003] Optical waveguide materials are typical dielectric devices for propagating optical signals and play a crucial role in optical integration. Based on the ability of emitting centers with different excited states to simultaneously capture multiple photons, constructing novel optical waveguide materials with tunable emission colors is at the forefront of research in optical communication and optical anti-counterfeiting. As information carriers, color-tunable optical waveguide materials can not only ensure accurate information transmission but also greatly expand information transmission capabilities. Among these, photochromic methods can not only efficiently control the emission color of optical waveguide materials, but their rich optical parameters also help to further control other properties of optical waveguide materials. However, currently, optical waveguide materials with photochromic properties are rarely reported. Summary of the Invention

[0004] The purpose of this invention is to provide a photochromic optical waveguide material and its preparation method. The material prepared by this invention: (1) possesses reversible photochromic properties; (2) has a smooth surface and a highly ordered structure, exhibiting excellent fluorescence-phosphorescence dual-emission optical waveguide properties, and demonstrating active optical waveguide properties both before and after photochromic changes. This material not only possesses photochromic properties based on fluorescence-phosphorescence dual emission, but also allows for effective modulation of its waveguide performance using photochromism, realizing the application of this novel waveguide material in the field of information coding.

[0005] The preparation method of the photochromic optical waveguide material is as follows: benzimidazole or benzimidazole derivative and zinc chloride are mixed, deionized water is added, and then concentrated hydrochloric acid or concentrated hydrobromic acid is added. After ultrasonic dissolution, the solvent is evaporated by heating at 30-50°C. The resulting crystal is washed and dried to obtain the photochromic optical waveguide material.

[0006] The amount of benzimidazole or benzimidazole derivative used is 1-100 mmol, the amount of zinc chloride used is 2-200 mmol, the amount of deionized water used is 3-3000 mL, and the amount of concentrated hydrochloric acid or concentrated hydrobromic acid used is 200-20000 μL.

[0007] The benzimidazole derivative is 2-(2-pyridine)-benzimidazole.

[0008] The photochromic optical waveguide material prepared above can be used as an information storage and information transmission material.

[0009] The method for information storage and transmission is as follows: test one or more of the ultraviolet-visible absorption spectrum, fluorescence spectrum, and phosphorescence spectrum of the photochromic optical waveguide material, with a scanning range of 200-800 nanometers; calculate the integral area of ​​the corresponding spectrum by extracting different nano-spectral intervals, and encode the obtained integral area to store and transmit information.

[0010] This invention presents a novel metal-organic halide material formed by the self-assembly of benzimidazole organic compounds and zinc chloride. The self-assembly of benzimidazole organic compounds and zinc chloride effectively promotes intersystem crossing between singlet and triplet states, achieving dual emission of fluorescence and phosphorescence. Furthermore, a suitable charge transfer path between halogen and nitrogen atoms endows the material with photochromic properties. Finally, due to the material's smooth surface and highly ordered structure, the prepared metal-organic halide material exhibits excellent optical waveguide properties. Importantly, the material retains its fluorescent-phosphorescent active waveguide properties before and after photochromism. Under different irradiation conditions, the fluorescence-phosphorescence emission wavelength of the active waveguide shows significant changes, exhibiting light-controlled multicolor waveguide properties. Therefore, we not only achieved photochromism based on fluorescent-phosphorescent dual emission but also utilized the material's photosensitivity to develop a class of highly secure and high-information-density micro-light-controlled active waveguide systems and demonstrated their application in the field of information encoding. Attached Figure Description

[0011] Figure 1 The metal-organic halide prepared in Example 1 has fluorescent and phosphorescent waveguide properties.

[0012] Figure 2 A schematic diagram illustrating the use of the metal-organohalides prepared in Example 1 as barcodes. Detailed Implementation

[0013] Example 1

[0014] 150 mg of 2-(2-pyridine)-benzimidazole, 272 mg of zinc chloride, and 200 μL of 36% concentrated hydrochloric acid were dissolved in 3 mL of deionized water. After sonication for 10 minutes, the reaction mixture was heated to 40 °C and maintained at this temperature for 24 hours. After the solvent evaporated, a one-dimensional rod-shaped crystal was obtained. The single crystal was separated and then washed and dried to obtain the target product, a photochromic optical waveguide material.

[0015] The product was characterized as follows:

[0016] Single-crystal X-ray diffraction analysis of the single-crystal products revealed that the metal-organic halide belongs to the triclinic crystal system, space group P-1. Among them, Zn... 2+ ZnCl4 coordinates with four chloride ions in a four-coordinate manner. 2- The unit cell exhibits a tetrahedral structure. The protonated molecules have two orientations in the lattice, arranged head-to-tail antiparallel in the asymmetric unit cell. Furthermore, the two co-crystallized components exhibit long-range ordered arrangement through cation-anion electrostatic interactions, hydrogen bonds, halogen bonds, and other interactions, ultimately constructing a metal-organohalide material.

[0017] Temperature-dependent spectroscopy and time-resolved lifetime decay characterization revealed that the luminescence intensity of this type of metal-organohalide decreased with increasing temperature at long wavelengths, and the excited-state decay lifetime reached the millisecond level, indicating that this material exhibits phosphorescence properties at long wavelengths. Spectroscopic analysis showed that when excited at 365 nm, the fluorescence and phosphorescence emission peaks of this metal-organohalide were at 438 nm and 590 nm, respectively, with a luminescence quantum yield of 17.76%. Under ultraviolet light excitation, this metal-organohalide emitted blue light, and after the excitation was stopped, it emitted a yellow phosphorescent afterglow visible to the human eye for about one second. After 25 minutes of ultraviolet irradiation, the fluorescence and phosphorescence emission peaks appeared at 475 nm and 560 nm, respectively, with a luminescence quantum yield of 3.13%. Simultaneously, the fluorescence color of this metal-organohalide changed from blue to cyan, and the phosphorescence color changed from yellow to green. Steady-state and delayed spectral characterization revealed that this type of metal-organohalide exhibits photochromic properties as well as fluorescence-phosphorescence dual emission characteristics.

[0018] Waveguide characterization revealed that this metal-organic halide exhibits both fluorescent and phosphorescent waveguide properties. Furthermore, the waveguide color shows a significant change before and after photochromism, indicating that the material possesses optically controlled multicolor waveguide properties. Figure 1 ).

[0019] Application Example 1

[0020] The metal-organic halide prepared in Example 1 exhibits multimode luminescence and photochromic properties, and its rich optical properties endow it with the potential to become an advanced information storage material. It is used as a barcode for information storage and transmission. The preparation and usage process is as follows: First, the solid-state UV-Vis absorption spectrum of the material is tested using a solid-state UV-Vis absorption spectrometer, or the fluorescence and phosphorescence spectra are tested using a fluorescence spectrometer. The scanning range of these spectra is 200-800 nm. After obtaining the corresponding spectral information, a specific interval can be encoded. Taking the solid-state UV-Vis absorption spectrum as an example, we first extract the 380-500 nm spectral interval. Then, according to actual needs and based on the width of the horizontal axis, it is divided into several equally wide parts; here, we divide it into five parts. Subsequently, the ratio of the integral area of ​​these five parts is calculated, and then solid barcodes with an area ratio equal to the ratio of the integral areas of the five parts are prepared according to a specification of 1 cm in height. Each corresponding solid barcode is placed in the middle of its corresponding spectral interval. This completes the preparation of barcodes based on the solid-state UV-Vis absorption spectrum with a specific scanning range. Using the same method, barcodes can also be prepared based on the fluorescence or phosphorescence spectra of the material. Furthermore, barcodes prepared from different spectra can be combined in any proportion as needed, thereby greatly expanding the information encoding capacity of the material. For example… Figure 2 As shown, the widths of the three sub-barcodes are assembled according to 15%, 35%, and 50% to obtain the final barcode.

[0021] Because the optical waveguide material prepared by this invention has multiple emission modes, each with a wide range of collectable spectra, and also exhibits photochromic properties, massive barcodes can be fabricated using the encoding method and material designed according to this invention. The fabrication of massive barcodes not only means the storage of massive amounts of information, but also provides better protection for information stored in barcodes with specific characteristics.

[0022] like Figure 2 As shown on the right, this metal-halide, used as an information storage tag, can be embedded in packaging and circulate with goods during production and freight transportation. As an information storage material, people can not only determine the authenticity of a product by observing the color change of the tag under different irradiation conditions, but also utilize a second, more advanced form of information storage. At room temperature, specific ranges of a spectrum can be collected using a solid-state UV-Vis absorption spectrometer and a fluorescence spectrometer. Then, according to encoding rules, a relevant barcode can be obtained. Only after obtaining the correct barcode can the actual stored information be retrieved.

Claims

1. A method of producing a photoconductive optical waveguide material, characterized by, The specific steps of the preparation method are as follows: 2-(2-pyridine)-benzimidazole and zinc chloride are mixed, deionized water is added, concentrated hydrochloric acid is added, ultrasonic dissolution is carried out, heating is carried out at 30-50 DEG C to volatilize the solvent, and the obtained crystal is washed and dried to obtain the photoconductive photo waveguide material. The amount of 2-(2-pyridine)-benzimidazole is 1-100 mmol, the amount of zinc chloride is 2-200 mmol, the amount of deionized water is 3-3000 mL, and the amount of concentrated hydrochloric acid is 200-20000 μL. The prepared photochromic optical waveguide material has Zn 2+ ZnCl4 2− The unit presents a tetrahedral structure.

2. The application of the photoconductive photo waveguide material prepared by the method of claim 1 as information storage and information transmission material.

3. Use according to claim 2, characterized in that, The information storage and information transmission method is as follows: one or more of ultraviolet-visible absorption spectrum, fluorescence spectrum and phosphorescence spectrum of the photoconductive photo waveguide material is tested, the scanning range is 200-800 nm, different nanometer spectral intervals are intercepted, the integral area of the corresponding spectrum is calculated, and the obtained integral area is coded to store and transmit information.

Images