NVP-doped PQ / PMMA photopolymer holographic storage materials and their preparation methods

Abstract

This invention relates to the field of holographic storage materials technology, specifically to an NVP-doped PQ / PMMA photopolymer holographic storage material and its preparation method. The NVP-doped PQ / PMMA photopolymer holographic storage material uses NVP, MMA, PQ, and AIBN as raw materials. NVP is doped into PQ / PMMA to achieve the photopolymer material as an excellent medium for holographic storage. This material has a simple preparation process, low cost, high diffraction efficiency, and high photosensitivity, making it better suited for holographic imaging and data storage compared to PQ / PMMA.

Description

Technical Field

[0001] This invention relates to the field of holographic storage materials technology, specifically to NVP-doped PQ / PMMA photopolymer holographic storage materials and their preparation methods. Background Technology

[0002] The advent of the information age and the era of big data has led to an explosive growth in the amount of information. Due to the limitations of two-dimensional planar storage technology, the storage capacity of technologies such as optical discs and hard disks has approached its theoretical limit, making it difficult to meet the storage needs of today's information age for massive amounts of data. Holographic storage, with its three-dimensional volumetric storage method and two-dimensional data transmission characteristics, has the advantages of large capacity and high transmission speed, and is considered a highly promising next-generation storage technology.

[0003] Currently, materials used for holographic recording mainly include silver halide latex, dichromate gelatin, photoresist, photorefractive crystals, photochromic materials, and photopolymers. Among these, photopolymers offer advantages such as high photosensitivity and high resolution compared to other recording materials, and they are also inexpensive and easy to prepare. Phenanthrenequinone-doped polymethyl methacrylate (PQ / PMMA) photopolymers stand out from other photopolymers due to their large thickness and low volume shrinkage. However, because phenanthrenequinone (PQ) has low solubility in methyl methacrylate (MMA), the diffraction efficiency of the material is not high.

[0004] The PQ / PMMA photopolymer material disclosed in Chinese invention patent CN112812210A uses MMA (methyl methacrylate), AIBN (azobisisobutyronitrile), and PQ to prepare a photopolymer with stable performance, allowing for multiple reads from a single recording, and exhibiting very low photo-induced shrinkage. However, the PQ- / PMMA material has a low content of the photosensitizer phenanthrenequinone (PQ), only 0.7 wt%, resulting in lower diffraction efficiency, photoresponse speed, and other properties. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an NVP-doped PQ / PMMA photopolymer holographic storage material with low raw material cost and good optical performance, and a method for preparing the same.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: an NVP-doped PQ / PMMA photopolymer holographic storage material, the raw materials of which include NVP, MMA, PQ and AIBN.

[0007] Another technical solution adopted in this invention is: a method for preparing an NVP-doped PQ / PMMA photopolymer holographic storage material, comprising the following steps: adding NVP, MMA, PQ and AIBN, and sequentially performing mixing and dissolution, prepolymerization and thermal polymerization to obtain an NVP-doped PQ / PMMA photopolymer holographic storage material.

[0008] The beneficial effects of this invention are as follows: The NVP-doped PQ / PMMA photopolymer holographic storage material and its preparation method provided by this invention dope PQ / PMMA with NVP to achieve the photopolymer material as an excellent medium for holographic storage. This material has a simple preparation process, low cost, high diffraction efficiency and photosensitivity, and can be better used in the fields of holographic imaging and data storage compared to PQ / PMMA. Attached Figure Description

[0009] Figure 1 These are diffraction efficiency test diagrams for Embodiment 2 and Comparative Example 1 of the present invention;

[0010] Figure 2 These are photosensitivity test diagrams for Embodiment 2 and Comparative Example 1 of the present invention. Detailed Implementation

[0011] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0012] An NVP-doped PQ / PMMA photopolymer holographic storage material is made of NVP, MMA, PQ and AIBN.

[0013] As can be seen from the above description, the beneficial effects of the present invention are as follows: The NVP-doped PQ / PMMA photopolymer holographic storage material provided by the present invention introduces NVP, in which the N atom is bonded to a vinyl group, enabling it to react with the photosensitizer PQ molecules during the photoreaction stage to generate photoproducts, thereby improving the efficiency of photoproduct production, thus increasing diffraction efficiency, photosensitivity, and shortening response time. Furthermore, because NVP has better solubility for PQ than MMA, PQ molecules can be more uniformly distributed in the system, thus improving the uniformity of the material.

[0014] Existing technologies involve adding NMP as an organic solvent to PQ / PMMA to improve the solubility of the photosensitizer PQ. However, NMP has a different structure than NVP and will not react with the original system to generate photoproducts. Therefore, the mechanisms by which the two are used to improve diffraction efficiency are different.

[0015] Furthermore, the mass ratio of NVP, MMA, AIBN, and PQ is 0.08~0.12:100:1:1.

[0016] As described above, introducing NVP monomers into the basic PQ / PMMA system allows for the provision of more C=C bonds during the photoreaction stage due to the vinyl structure of NVP, leading to the generation of more and faster photoproducts. If the proportion of NVP doping is too low, the number of C=C bonds provided will decrease, and the material's performance will not be significantly improved. Furthermore, since NVP is in a liquid state, excessive doping will affect the molding effect of the material after baking.

[0017] Another technical solution adopted in this invention is: a method for preparing an NVP-doped PQ / PMMA photopolymer holographic storage material, comprising the following steps: adding NVP, MMA, PQ and AIBN, and sequentially performing mixing and dissolution, prepolymerization and thermal polymerization to obtain an NVP-doped PQ / PMMA photopolymer holographic storage material.

[0018] As can be seen from the above description, the preparation process is simple, the raw materials are inexpensive, and the prepared photopolymer has high diffraction efficiency and photosensitivity.

[0019] Furthermore, the specific steps for mixing and dissolving are as follows: sonicate in a water bath at 58~62℃ for 10~15 minutes.

[0020] As can be seen from the above description, the purpose of sonication is to fully dissolve solid reagents (AIBN, PQ). For conventional MMA, the solubility is not ideal, so a longer time is required. However, with the introduction of NVP, the sonication time can be shortened to a certain extent.

[0021] Furthermore, the specific steps for prepolymerization are as follows: stirring at 58~62℃ for 85~90 min.

[0022] As can be seen from the above description, the purpose of prepolymerization is to allow MMA small molecules to polymerize into PMMA long chains. For conventional materials, a good degree of polymerization can be achieved by controlling the time to 70-80 minutes. However, after introducing NVP, due to the certain polymerization inhibition effect of NVP, a longer prepolymerization time is required to achieve a similar degree of polymerization.

[0023] Furthermore, the specific steps of thermal polymerization are as follows: place at 58~62℃ for 20~21 hours.

[0024] Embodiment 1 of the present invention is: an NVP-doped PQ / PMMA photopolymer holographic storage material, which is made of NVP, MMA, AIBN and PQ in a mass ratio of 0.1:100:1:1.

[0025] Embodiment 2 of the present invention is: a method for preparing an NVP-doped PQ / PMMA photopolymer holographic storage material, comprising the following steps:

[0026] S1: Weigh NVP, MMA, AIBN and PQ in a mass ratio of 0.1:100:1:1, mix them and dissolve them by sonication in a 60℃ water bath for 12 minutes;

[0027] S2: Stir the dissolved mixture at 60°C for 87 minutes to perform prepolymerization;

[0028] S3: Inject the prepolymerized mixture into a mold with a height of 2mm. Then place the mold in an oven at 60℃ and bake for 20.5h to obtain sheet-like NVP-doped PQ / PMMA photopolymer holographic storage material.

[0029] Embodiment 3 of the present invention is as follows:

[0030] A method for preparing an NVP-doped PQ / PMMA photopolymer holographic storage material includes the following steps:

[0031] S1: Weigh NVP, MMA, AIBN and PQ in a mass ratio of 0.08:100:1:1, mix them and dissolve them by sonication in a 58℃ water bath for 15 minutes;

[0032] S2: Stir the dissolved mixture at 58°C for 90 minutes to perform prepolymerization;

[0033] S3: Inject the prepolymerized mixture into a mold with a height of 2mm. Then place the mold in an oven at 58℃ and bake for 21 hours to obtain sheet-like NVP-doped PQ / PMMA photopolymer holographic storage material.

[0034] Embodiment four of the present invention is as follows:

[0035] A method for preparing an NVP-doped PQ / PMMA photopolymer holographic storage material includes the following steps:

[0036] S1: Weigh NVP, MMA, AIBN and PQ in a mass ratio of 0.12:100:1:1, mix them and dissolve them by sonication in a 62℃ water bath for 10 minutes;

[0037] S2: Stir the dissolved mixture at 62°C for 85 minutes to perform prepolymerization;

[0038] S3: Inject the prepolymerized mixture into a mold with a height of 2mm. Then place the mold in an oven at 62℃ and bake for 20 hours to obtain sheet-like NVP-doped PQ / PMMA photopolymer holographic storage material.

[0039] Comparative Example 1 of the present invention is:

[0040] The only difference between Comparative Example 1 and Example 2 is that NVP is not added, and the mass ratio of MMA, AIBN and PQ is 100:1:1.

[0041] The diffraction efficiency of Example 2 (NVP-PQ / PMMA) and Comparative Example 1 (PQ / PMMA) was tested, and the test results are shown in [the table below]. Figure 1 ;Depend on Figure 1 It can be seen that the diffraction efficiency of the NVP-doped PQ / PMMA photopolymer holographic storage material in Example 1 reached 80%, shortened the photoresponse speed, and the NVP-doped PQ / PMMA material had better uniformity.

[0042] The photosensitivity of Example 2 (NVP-PQ / PMMA) and Comparative Example 1 (PQ / PMMA) was tested, and the test results are shown in [link to test results]. Figure 2 ;Depend on Figure 2 It is known that NVP-doped PQ / PMMA has higher photosensitivity.

[0043] The above test methods are described in the reference: Po Hu, Jinhong Li, Junchao Jin, Xiao Lin, & Xiaodi Tan. Highly Sensitive Photopolymer for Holographic Data Storage Containing Methacryl Polyhedral Oligomeric Silsesquioxane [J]. ACS Appl. Mater. Interfaces 2022, 14, 18, 21544–21554.

[0044] In summary, this invention provides a method for preparing NVP-doped PQ / PMMA photopolymer holographic storage materials. The preparation process is simple, efficient, and uses inexpensive raw materials. Compared to the original PQ / PMMA materials, the prepared NVP-doped PQ / PMMA photopolymer materials, with approximately 0.1 wt% NVP doping, exhibit higher diffraction efficiency, reaching over 80%. The NVP-doped PQ / PMMA photopolymer holographic storage materials introduce NVP, whose nitrogen atom is bonded to a vinyl group. This allows NVP to react with the photosensitizer PQ molecules during the photoreaction stage to generate photoproducts, improving the efficiency of photoproduct production and thus enhancing diffraction efficiency, photosensitivity, and shortening response time. Furthermore, because NVP has better solubility for PQ than MMA, PQ molecules can be more uniformly distributed in the system, improving the material's uniformity.

[0045] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A NVP doped PQ\PMMA photopolymer holographic storage material characterized in that, The NVP, MMA, AIBN and PQ have a mass ratio of 0.08-0.12:100:1:

1.

2. A method for preparing NVP doped PQ\PMMA photopolymer holographic storage material, characterized in that, The method comprises the following steps: NVP, MMA, PQ and AIBN are added, and mixed dissolving, pre-polymerization and thermal polymerization are sequentially carried out to obtain a NVP-doped PQ / PMMA photopolymer holographic storage material. The NVP, MMA, AIBN and PQ have a mass ratio of 0.08-0.12:100:1:

1.

3. The method for preparing the NVP-doped PQ / PMMA photopolymer holographic storage material according to claim 2, characterized in that, The specific step of the mixed dissolving is ultrasonic treatment in a 58-62 ℃ water bath for 10-15 min.

4. The method for preparing the NVP-doped PQ / PMMA photopolymer holographic storage material according to claim 2, characterized in that, The specific step of the pre-polymerization is stirring at 58-62 ℃ for 85-90 min.

5. The method for preparing the NVP-doped PQ / PMMA photopolymer holographic storage material according to claim 2, characterized in that, The specific step of the thermal polymerization is placing at 58-62 ℃ for 20-21 h.

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