A porphyrin two-dimensional polymer nonlinear optical material and its preparation and application

Abstract

The present invention relates to a porphyrin two-dimensional polymer nonlinear optical material and its preparation and application. A bottom-up growth strategy is adopted, and a monomer self-coupling polymerization reaction is utilized. With the assistance of a template agent, a porphyrin two-dimensional polymer nonlinear optical material is obtained by reaction. Compared with the existing technology, the material of the present invention not only has a broadened conjugated plane and an ultra-thin nanosheet morphology, but also has excellent dispersibility and can be further prepared into a thin film device. The device exhibits broadband optical radiation limiting performance across the visible light region and the near-infrared light region for the first time under an ultrafast pulse laser. At the same time, the reaction monomer is easy to obtain, the preparation process is simple to operate, easy to control, and suitable for mass production.

Description

Technical Field

[0001] The invention belongs to the technical field of two-dimensional polymer nonlinear optical materials, and relates to a porphyrin two-dimensional polymer nonlinear optical material and a preparation method and application thereof. Background Art

[0002] Ultrafast lasers have promoted the development of nanomedicine, communications, nanoprocessing and other fields. However, the high energy of ultrafast lasers poses potential risks to photosensitive devices and even the human eye. Therefore, it is particularly important to use ultrafast pulsed lasers rationally and efficiently. Optical limiting is a type of device that can control the intensity of laser pulses to protect optical devices and human eyes from unacceptable energy exposure. The optical limiting performance depends on materials with anti-saturation absorption or multiphoton absorption. Most of the optical limiting materials reported so far are concentrated in organic small molecules, nanocrystals, and organic-inorganic hybrid materials. However, their optical limiting performance is mostly observed in solutions or dispersions, and the solution system is not conducive to practical application scenarios. Therefore, it is of great scientific significance to develop an optical limiting device for the protection of ultrafast lasers.

[0003] Two-dimensional materials have the advantages of fast optical response and strong exciton effect, and may achieve excellent performance in the field of nonlinear optics. Porphyrin monomers have abundant π electrons, and the surrounding conjugated environment can change the electronic structure of porphyrin, thereby regulating its optical properties. The expanded conjugated structure obtained by integrating porphyrin monomers in two-dimensional space not only has the properties of porphyrin monomers, but also has the performance of two-dimensional materials, and is expected to achieve optical radiation limiting performance under ultrafast pulsed lasers.

[0004] For example, Chinese patent CN202210503555.2 discloses a self-supporting crystalline two-dimensional polymer nonlinear thin film material and its preparation and application, which utilizes monomer self-assembly-assisted interfacial polymerization reaction to construct an interface with mutually immiscible aqueous phase and organic phase. Under the action of a catalyst, the two monomers undergo polymerization reaction at the interface under room temperature to obtain a self-supporting crystalline two-dimensional polymer nonlinear thin film material. However, the synthesis involved in the patent requires a very long reaction time, and the preparation process is relatively complicated, involving the addition of multiple reactants, which brings a lot of inconvenience to the post-processing process. Summary of the invention

[0005] The purpose of the present invention is to provide a porphyrin two-dimensional polymer nonlinear optical material and its preparation and application in order to overcome the defects of the above-mentioned prior art. The material has a two-dimensional film structure and a large conjugated plane. At the same time, the nonlinear optical material can be further prepared into a device. Under the excitation of ultrafast laser, the device exhibits good nonlinear optical absorption phenomenon, specifically excited state absorption and two-photon absorption. .

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] One of the technical solutions of the present invention provides a method for preparing a porphyrin two-dimensional polymer nonlinear optical material, comprising the following steps:

[0008] (1) weighing a monomer of 5,10,15,20-tetrakis(4-bromophenyl)porphyrin, dissolving it in a solvent, adding it to sodium chloride, evaporating the solvent therein, and obtaining a uniform mixture of 5,10,15,20-tetrakis(4-bromophenyl)porphyrin and sodium chloride;

[0009] (2) The obtained mixture is placed in a porcelain boat, placed in a tube furnace, and reacted under the protection of an inert atmosphere to obtain a crude product, which is then washed to obtain the target product.

[0010] Furthermore, in step (1), the mass ratio of 5,10,15,20-tetrakis(4-aminophenyl)porphyrin to sodium chloride is 1:(2000-8000).

[0011] Furthermore, in step (1), the solvent is dichloromethane.

[0012] Furthermore, in step (2), the reaction temperature is 200-600°C.

[0013] Furthermore, in step (2), the reaction time is 1 to 15 hours.

[0014] Furthermore, in step (2), the inert atmosphere is nitrogen.

[0015] Furthermore, the washing process is: repeatedly washing and filtering with an organic solvent and distilled water until the filtrate is colorless; the organic solvent is selected from one or more of methanol, ethanol, dichloromethane, 1,3,5-trimethylbenzene, dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran, petroleum ether or N-methylpyrrolidone.

[0016] During the reaction, sodium chloride acts as a template. A suitable solvent is selected to fully dissolve the porphyrin monomer, fully mix it with the sodium chloride, and then evaporate the solvent. The purpose is to allow the porphyrin monomer to be evenly adsorbed on the surface of the sodium chloride.

[0017] The second technical solution of the present invention provides a porphyrin two-dimensional polymer nonlinear optical material, which is prepared by any of the preparation methods described above, and the nonlinear optical material has an extended conjugated structure and an ultra-thin nanosheet morphology. Specifically, the thickness of the nanosheet is about 4-5nm and the lateral size is about 30-40μm.

[0018] A third technical solution of the present invention provides an application of a porphyrin two-dimensional polymer nonlinear optical material, and the nonlinear optical material is used for constructing an ultrafast laser response device.

[0019] Furthermore, the process of constructing an ultrafast laser response device with nonlinear optical materials is as follows: dispersing the prepared porphyrin two-dimensional polymer material in one of tetrahydrofuran, dichloromethane, and N,N-dimethylformamide, placing a substrate in the dispersion, and volatilizing the solvent to obtain a device. The substrate includes at least one of quartz glass, silicon wafer, glass slide, cover glass, and polyethylene terephthalate.

[0020] Furthermore, the ultrafast laser response device is applicable to an ultrafast laser waveband of 400 to 2000 nm.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. Compared with traditional optically sensitive materials, the porphyrin two-dimensional polymer nonlinear optical material prepared in the present invention has a very high conjugation property, provides sufficient space for electron delocalization, has a very wide optical absorption band, and is conducive to generating ultrafast laser response.

[0023] Second, the porphyrin two-dimensional polymer nonlinear optical material prepared in the present invention has very good dispersibility, and the prepared optical device overcomes the shortcomings of uneven surface and poor performance of the device prepared by the traditional method. Under ultrafast laser excitation, it has ultra-high nonlinear optical response. And it has excellent thermal stability and can meet the requirements of practical applications.

[0024] 3. The present invention uses the porphyrin two-dimensional polymer material for the first time to construct an ultrafast laser response device, and has good nonlinear optical properties, which can be used for broadband optical limiting applications of ultrafast laser response. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the synthesis of the porphyrin two-dimensional polymer nonlinear optical material prepared by the present invention;

[0026] Figure 2 is a scanning electron microscope (SEM) photograph of the porphyrin two-dimensional polymer nonlinear optical material prepared in Example 1;

[0027] Figure 3 is a transmission electron microscope (TEM) photograph of the porphyrin two-dimensional polymer nonlinear optical material prepared in Example 1;

[0028] Figure 4 is an absorption spectrum of the porphyrin two-dimensional polymer nonlinear optical material prepared in Example 2;

[0029] Figure 5This is a diagram of the ultrafast nonlinear performance of the porphyrin two-dimensional polymer nonlinear optical material device prepared in Example 3.

[0030] Figure 6 is a scanning electron microscope (SEM) photograph of the material of Comparative Example 1 prepared in the present invention;

[0031] Figure 7 It is a scanning electron microscope (SEM) photograph of the material of Comparative Example 2 prepared in the present invention. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0033] In the following examples, unless otherwise specified, raw materials or processing techniques are conventional commercial products or conventional processing techniques in the art.

[0034] Embodiment 1:

[0035] The preparation of porphyrin two-dimensional polymer nonlinear optical material specifically includes the following steps:

[0036] (1) Weigh 20 mg of monomer 5,10,15,20-tetrakis(4-bromophenyl)porphyrin, dissolve it in 50 mL of dichloromethane, add it to 100 g of sodium chloride, evaporate the dichloromethane, and obtain a uniform mixture of 5,10,15,20-tetrakis(4-bromophenyl)porphyrin and sodium chloride.

[0037] (2) The obtained mixture was placed in a porcelain boat, put into a tube furnace, and reacted under nitrogen protection at a temperature of 300° C. for 8 hours to obtain a crude product.

[0038] (3) The obtained crude product is washed with dichloromethane, tetrahydrofuran and distilled water to obtain the target product.

[0039] The prepared porphyrin two-dimensional polymer nonlinear optical material is dispersed in dichloromethane to prepare an ultrafast laser response device.

[0040] In addition, the device prepared as above was used for ultrafast laser optical testing. Under 35fs pulse laser excitation, wavelength in the range of 400-2000nm, and energy of 0.2-500uJ, the nonlinear performance was tested using Z scanning technology.

[0041] Embodiment 2:

[0042] The preparation of porphyrin two-dimensional polymer nonlinear optical material specifically includes the following steps:

[0043] (1) Weigh 20 mg of monomer 5,10,15,20-tetrakis(4-bromophenyl)porphyrin, dissolve it in 50 mL of dichloromethane, add it to 100 g of sodium chloride, evaporate the dichloromethane, and obtain a uniform mixture of 5,10,15,20-tetrakis(4-bromophenyl)porphyrin and sodium chloride.

[0044] (2) The obtained mixture was placed in a porcelain boat, put into a tube furnace, and reacted under nitrogen protection at a reaction temperature of 500° C. for 8 hours to obtain a crude product.

[0045] (3) The crude product is washed with dichloromethane, tetrahydrofuran and distilled water to obtain the target product.

[0046] The prepared porphyrin two-dimensional polymer nonlinear optical material is dispersed in dichloromethane to prepare an ultrafast laser response device.

[0047] In addition, the device prepared as above was used for ultrafast laser optical testing. Under 35fs pulse laser excitation, wavelength in the range of 400-2000nm, and energy of 0.2-500uJ, the nonlinear performance was tested using Z scanning technology.

[0048] Embodiment 3:

[0049] The preparation of porphyrin two-dimensional polymer nonlinear optical material specifically includes the following steps:

[0050] (1) Weigh 20 mg of monomer 5,10,15,20-tetrakis(4-bromophenyl)porphyrin, dissolve it in 50 mL of dichloromethane, add it to 100 g of sodium chloride, evaporate the dichloromethane, and obtain a uniform mixture of 5,10,15,20-tetrakis(4-bromophenyl)porphyrin and sodium chloride.

[0051] (2) The obtained mixture was placed in a porcelain boat, put into a tube furnace, and reacted under nitrogen protection at a reaction temperature of 500° C. for 14 hours to obtain a crude product.

[0052] (3) The obtained crude product is washed with dichloromethane, tetrahydrofuran and distilled water to obtain the target product.

[0053] The prepared porphyrin two-dimensional polymer nonlinear optical material is dispersed in dichloromethane to prepare an ultrafast laser response device.

[0054] In addition, the device prepared as above was used for ultrafast laser optical testing. Under 35fs pulse laser excitation, wavelength in the range of 400-2000nm, and energy of 0.2-500uJ, the nonlinear performance was tested using Z scanning technology.

[0055] Comparative Example 1:

[0056] Compared with Example 1, most of them are the same, except that the addition of sodium chloride is omitted.

[0057] Comparative Example 2:

[0058] Compared with Example 1, most of them are the same, and the mass ratio of monomer 5,10,15,20-tetrakis(4-bromophenyl)porphyrin to sodium chloride is 1:1000.

[0059] Figure 1 A schematic diagram for the synthesis of porphyrin two-dimensional polymer nonlinear optical materials is given.

[0060] Figure 2 A scanning electron microscope (SEM) photograph of the porphyrin two-dimensional polymer nonlinear optical material prepared in Example 1 of the present invention is given. From the photograph, it can be seen that the nanosheet morphology is obvious, which verifies the expected result of Example 1.

[0061] Figure 3 A transmission electron microscope (TEM) photograph of the porphyrin two-dimensional polymer nonlinear optical material prepared in Example 1 of the present invention is given, which further verifies that the microscopic morphology of the synthesized material is nanosheets, verifying the expected results of Example 1.

[0062] Figure 4 The optical absorption performance diagram of the porphyrin two-dimensional polymer nonlinear optical material prepared in Example 2 of the present invention is given. It can be seen from the figure that the prepared porphyrin two-dimensional polymer nonlinear optical material has broadband absorption from the visible light region to the infrared light region, verifying the expected results of Example 2.

[0063] Figure 5 The ultrafast optical performance diagram of the porphyrin two-dimensional polymer nonlinear optical device prepared in Example 3 of the present invention is given. Under different excitation wavelengths, the device exhibits obvious nonlinear absorption, specifically anti-saturation absorption and two-photon absorption behavior.

[0064] Figure 6 A scanning electron microscope (SEM) photograph of the porphyrin two-dimensional polymer nonlinear optical material prepared in Comparative Example 1 is given. It can be seen from the picture that although nanosheets are generated, the size of the nanosheets is very small, which verifies the results of Example 1 and Comparative Example 1, indicating that sodium chloride plays an important role in the morphology of the product during the synthesis process.

[0065] Figure 7A scanning electron microscope (SEM) photograph of the porphyrin two-dimensional polymer nonlinear optical material prepared in Comparative Example 2 is given. From the picture, it can be seen that the morphology of the generated nanosheets is not obvious and they are stacked together, which verifies the results of Example 1 and Comparative Example 2, indicating that the mass ratio of porphyrin monomer and sodium chloride affects the morphology of the product. During the reaction, the appropriate mass ratio of the two should be controlled.

[0066] Functions and Effects of the Embodiments

[0067] In general, according to the porphyrin two-dimensional polymer nonlinear optical material provided by the present invention, a crude product is obtained by a template-assisted monomer coupling reaction, which is washed with distilled water and an organic solvent, and then an ultrafast laser response device is constructed. The device has a very good nonlinear response under ultrafast pulse laser, which is specifically manifested in excited state absorption and two-photon absorption behavior.

[0068] Scanning electron microscopy and transmission electron microscopy tests of the prepared porphyrin two-dimensional polymer nonlinear optical material show that it exhibits an obvious thin film structure.

[0069] The prepared porphyrin two-dimensional polymer device has excellent ultrafast optical response, which meets the needs of practical applications. It is also simple to operate, has high repeatability, and the reaction conditions are easy to control and can be easily mass-produced.

[0070] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for preparing a porphyrin two-dimensional polymer nonlinear optical material, characterized in that: The following steps are involved: (1) Weighing monomer 5,10,15,20-tetrakis(4-bromophenyl)porphyrin, dissolving it in a solvent, adding it into sodium chloride, evaporating the solvent therein, and obtaining a uniform mixture of 5,10,15,20-tetrakis(4-bromophenyl)porphyrin and sodium chloride; (2) placing the obtained mixture in a porcelain boat, placing it in a tube furnace, reacting it under the protection of an inert atmosphere to obtain a crude product, and washing it to obtain the target product; In step (1), the mass ratio of 5,10,15,20-tetrakis(4-bromophenyl)porphyrin to sodium chloride is 1:(2000-8000).

2. The method for preparing a porphyrin two-dimensional polymer nonlinear optical material according to claim 1, characterized in that: In step (1), the solvent is dichloromethane.

3. The method for preparing a porphyrin two-dimensional polymer nonlinear optical material according to claim 1, characterized in that: In step (2), the reaction temperature is 200-600°C.

4. The method for preparing a porphyrin two-dimensional polymer nonlinear optical material according to claim 1, characterized in that: In step (2), the reaction time is 1 to 15 hours.

5. The method for preparing a porphyrin two-dimensional polymer nonlinear optical material according to claim 1, characterized in that: In step (2), the inert atmosphere is nitrogen.

6. The method for preparing a porphyrin two-dimensional polymer nonlinear optical material according to claim 1, characterized in that: The washing process is: repeatedly washing and filtering with an organic solvent and distilled water until the filtrate is colorless; the organic solvent is selected from one or more of methanol, ethanol, dichloromethane, 1,3,5-trimethylbenzene, dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran, petroleum ether or N-methylpyrrolidone.

7. A porphyrin two-dimensional polymer nonlinear optical material, prepared by the preparation method according to any one of claims 1 to 6, characterized in that: The nonlinear optical material has an extended conjugated structure and an ultrathin nanosheet morphology.

8. The use of the porphyrin two-dimensional polymer nonlinear optical material according to claim 7, characterized in that: The nonlinear optical material is used to construct ultrafast laser response devices.

9. The use of the porphyrin two-dimensional polymer nonlinear optical material according to claim 8, characterized in that: The ultrafast laser response device is suitable for an ultrafast laser waveband of 400-2000 nm.

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