Preparation method of patterned UiO series inorganic films based on femtosecond laser direct writing and gelled ligand solution

Abstract

This invention discloses a method for preparing patterned UiO series inorganic films based on femtosecond laser direct writing and a gelled ligand solution. The method for preparing patterned UiO series inorganic films based on femtosecond laser direct writing includes the following steps: A: preparation of patterned ZrO2 thin films; B: preparation of gelled ligand solution for UiO series inorganic films; C: preparation of UiO series inorganic films. This invention provides a gelled ligand solution for preparing UiO series inorganic films, which is prepared by dissolving an organic ligand and a modifier in DMF to obtain a gelled ligand solution; the modifier is triethylamine or potassium hydroxide; the organic ligand is one of the following compounds a-c. This invention uses a gel spin-coating method to prepare patterned UiO series inorganic films, which not only reduces the amount of solvent used but also effectively lowers the reaction temperature, enabling the acquisition of micron-scale patterned UiO series inorganic films.

Description

Technical Field

[0001] This invention belongs to the field of patterned materials, specifically relating to a method for preparing patterned UiO series inorganic films based on femtosecond laser direct writing and a gelled ligand solution for preparing UiO series inorganic films. Background Technology

[0002] Femtosecond laser direct writing technology is a technique that directly processes photoresist using a femtosecond laser beam. It requires no mask, has a wide range of applications, and is cost-effective. It is widely used in micro-nano fabrication fields such as microfluidics, micro-nano optical devices, and metamaterials.

[0003] Metal-organic frameworks (MOFs) are crystalline materials with three-dimensional networks, formed by the self-assembly of organic ligands and metal ions or metal clusters. They possess characteristics such as large specific surface area, high porosity, suitable dielectric constant, and abundant modifiable sites, and are used in gas separation, catalysis, luminescence, and electronic devices. The UiO series MOFs are Zr... 4+ Three-dimensional porous materials constructed with dicarboxylic acid ligands exhibit superior stability compared to most MOF materials, showing broad application prospects in photocatalysis, sensing, medicine, and supercapacitors. However, solid powders of MOF particles cannot meet the demands of real-world devices; fabricating patterned MOF films is a prerequisite for their use in electronic devices. In 2016, Rob Ameloot's group reported a method for preparing MOF thin films based on chemical vapor deposition, which holds promise for industrial chip manufacturing (Nat. Mater., 2016, 15, 304-310). Subsequently, the group proposed a method combining photoresist-free X-ray imprinting and electron beam imprinting to prepare high-quality patterned MOF films (Nat. Mater., 2021, 20, 93-99). However, current MOF film patterning still faces challenges such as high cost, complex fabrication, insufficient precision, and limited MOF types, failing to meet practical application requirements.

[0004] Therefore, there is an urgent need to develop a novel method for patterning and preparing micron-scale MOF film materials. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a simple method for patterning UiO series MOFs films using femtosecond laser direct writing technology, and a gelled ligand solution for preparing UiO series inorganic films.

[0006] The technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for preparing patterned UiO series inorganic films based on femtosecond laser direct writing, comprising the following steps:

[0008] A: Preparation of patterned ZrO2 thin films:

[0009] A zirconium-based photoresist was prepared by mixing a photoinitiator, a zirconium-based monomer, and a solvent in a certain proportion. After filtration, the photoresist was dropped onto a glass substrate and a zirconium-based photoresist film was prepared by spin coating. The zirconium-based photoresist film was then exposed to a preset pattern using a femtosecond laser and then developed to obtain a photoresist pattern. Finally, the photoresist pattern was placed in a muffle furnace and annealed at 500–700°C for 2–4 hours in an air atmosphere to prepare a patterned ZrO2 film.

[0010] B: Preparation of gelled ligand solutions for UiO series inorganic membranes:

[0011] The organic ligand and regulator are dissolved in N,N-dimethylformamide (DMF), dissolved by sonication, homogenized on a gel coater, and allowed to stand to obtain a gelled ligand solution; the regulator is triethylamine or potassium hydroxide; the organic ligand is one of the following compounds ac; the molar ratio of the organic ligand, regulator and N,N-dimethylformamide is 1:2 to 5:50 to 90;

[0012]

[0013] C: Preparation of UiO series inorganic membranes:

[0014] The patterned ZrO2 thin film (including glass substrate) obtained in step A is placed on a spin coater, and an appropriate amount of gelation ligand solution is added. The UiO series inorganic film precursor is obtained by spin coating. The inorganic film precursor is placed in a vacuum drying oven and heated to react. The film after reaction is washed and dried to obtain the patterned UiO series inorganic film.

[0015] Preferably, in step A, the zirconium monomer is zirconium acrylate, zirconium methacrylate, or a mixture thereof, the initiator is 7-diethylamino-3-thiophenecarboxycoumarin, and the solvent is propylene glycol methyl ether acetate (PGMEA), acetone, or a mixture thereof.

[0016] Preferably, in step A, the zirconium-based photoresist contains zirconium-based monomers accounting for 2-10% of the solvent mass and initiators accounting for 0.2-2.5% of the zirconium-based monomer mass.

[0017] Preferably, in step A, the spin coating conditions are: first spin coating at 1000 rpm for 6-8 seconds, then spin coating at 2000 rpm for 30-60 seconds.

[0018] Preferably, in step A, the zirconium-based photoresist film is exposed using a femtosecond laser under the following conditions: scanning speed 5-10 mm / s, writing power 40-60 mW.

[0019] Preferably, in step A, the development is a two-stage development, with the primary developer being acetone or PGMEA and the primary development time being 30 seconds; the secondary developer is isopropanol (IPA) and the secondary development time is 60-90 seconds.

[0020] Preferably, in step A, the heating rate during annealing is 15°C / min, and the cooling rate is 2°C / min.

[0021] Preferably, in step B, the settling time after homogenization is 0.5-6 hours.

[0022] Preferably, in step C, the spin coating speed is 3000-8000 rpm and the spin time is 60-300 s.

[0023] Preferably, in step C, the heating reaction temperature is 70–120°C and the reaction time is 10–96 h.

[0024] Preferably, in step C, the washing and drying are performed by thoroughly washing with methanol and then vacuum drying overnight at room temperature.

[0025] In step C of this invention, the amount of gelling ligand solution added is determined based on the zirconium content in the patterned zirconium oxide film, generally so that the molar ratio of zirconium to ligand is about 1:1.

[0026] Secondly, the present invention provides a gelled ligand solution for preparing UiO series inorganic membranes, wherein the gelled ligand solution is prepared by the following method: dissolving an organic ligand and a modifier in N,N-dimethylformamide (DMF), dissolving by ultrasonication, homogenizing on a homogenizer, and allowing to stand to obtain a gelled ligand solution; wherein the modifier is triethylamine or potassium hydroxide; wherein the organic ligand is one of the following compounds ac; and wherein the molar ratio of the organic ligand, modifier, and DMF is 1:2 to 5:50 to 90.

[0027]

[0028] The gelled ligand solution is used to prepare UiO series inorganic films by the following method: a patterned ZrO2 film containing a glass substrate is placed on a spin coater, an appropriate amount of gelled ligand solution is added, and spin-coating is performed to obtain a UiO series inorganic film precursor; the inorganic film precursor is placed in a vacuum drying oven and heated to react; the reacted film is washed and dried to obtain the patterned UiO series inorganic film. Details of the above preparation method can be found in step C of the first aspect. The preparation of the patterned ZrO2 film is described in step A of the first aspect, and will not be repeated here.

[0029] The beneficial effects of this invention are as follows:

[0030] (1) This invention is the first to use the femtosecond laser direct writing method to prepare patterned UiO series inorganic films. No mask is required, and the size and position of the corresponding pattern can be processed quickly, ultimately realizing the controllable preparation of MOFs films with arbitrary patterns including the micron scale.

[0031] (2) This invention is the first to use the gel spin coating method to prepare patterned UiO series inorganic films. Compared with the traditional hydrothermal method, it not only reduces the amount of solvent used, but also effectively lowers the reaction temperature, and can obtain micron-scale patterned UiO series inorganic films. It is an environmentally friendly preparation method.

[0032] (3) The gelled ligand solution used in this invention helps to obtain micron-scale patterned UiO series inorganic membranes.

[0033] (4) This invention promotes the fabrication of MOF films in the fields of supercapacitors and semiconductor microdevices. Attached Figure Description

[0034] Figure 1 These are SEM images of the zirconium-based photoresist photolithography design pattern (left) and the pattern after high-temperature annealing (right) in Example 1;

[0035] Figure 2 This is a schematic diagram of the structure of the UiO-66 material in Example 1;

[0036] Figure 3 This is the XRD pattern of the patterned UiO-66 film obtained in Example 1;

[0037] Figure 4 This is a SEM image of the patterned UiO-66 film obtained in Example 1;

[0038] Figure 5 The image is a SEM image of the UiO-66 membrane obtained in Comparative Example 1;

[0039] Figure 6 The image shown is the XRD pattern of the thin film obtained in Comparative Example 2;

[0040] Figure 7 This is a SEM image of the patterned UiO-66 film obtained in Example 2;

[0041] Figure 8 This is the XRD pattern of the patterned UiO-66-NH2 film obtained in Example 3;

[0042] Figure 9 This is a SEM image of the patterned UiO-66-NH2 film obtained in Example 4;

[0043] Figure 10This is the XRD pattern of the patterned UiO-67 film obtained in Example 5;

[0044] Figure 11 This is a SEM image of the patterned UiO-67 film obtained in Example 6;

[0045] Figure 12 This is a schematic diagram of the femtosecond laser direct writing device used in an embodiment of the present invention, wherein 1-femtosecond laser, 2-galvanometer, 3-objective lens, 4-displacement stage, and 5-photoresist. Detailed Implementation

[0046] The following examples will further illustrate the content of the present invention. However, these examples do not limit the scope of protection of the present invention. Based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the present invention.

[0047] The present invention discloses a method for preparing patterned UiO series inorganic films based on femtosecond laser direct writing, comprising the following steps:

[0048] A: Preparation of patterned ZrO2 thin films:

[0049] A zirconium-based photoresist was prepared by mixing a photoinitiator, a zirconium-based monomer, and a solvent in a certain proportion. After filtration, the photoresist was dropped onto a glass substrate and a zirconium-based photoresist film was prepared by spin coating. The zirconium-based photoresist film was then exposed to a preset pattern using a femtosecond laser and then developed to obtain a photoresist pattern. Finally, the photoresist pattern was placed in a muffle furnace and annealed at 500–700°C for 2–4 hours in an air atmosphere to prepare a patterned ZrO2 film.

[0050] B: Preparation of gelled ligand solutions for UiO series inorganic membranes:

[0051] The organic ligand and regulator are dissolved in N,N-dimethylformamide (DMF), dissolved by sonication, homogenized on a gel coater, and allowed to stand to obtain a gelled ligand solution; the regulator is triethylamine or potassium hydroxide; the organic ligand is one of the following compounds ac; the molar ratio of the organic ligand, regulator and DMF is 1:2 to 5:50 to 90;

[0052]

[0053] C: Preparation of UiO series inorganic membranes:

[0054] The patterned ZrO2 thin film (including glass substrate) obtained in step A is placed on a spin coater, and an appropriate amount of gelation ligand solution is added. The UiO series inorganic film precursor is obtained by spin coating. The inorganic film precursor is placed in a vacuum drying oven and heated to react. The film after reaction is washed and dried to obtain the patterned UiO series inorganic film.

[0055] Preferably, in step A, the zirconium monomer is zirconium acrylate, zirconium methacrylate, or a mixture thereof, the initiator is 7-diethylamino-3-thiophenecarboxycoumarin, and the solvent is propylene glycol methyl ether acetate (PGMEA), acetone, or a mixture thereof.

[0056] Preferably, in step A, the zirconium-based photoresist contains zirconium-based monomers accounting for 2-10% of the solvent mass and initiators accounting for 0.2-2.5% of the zirconium-based monomer mass.

[0057] Preferably, in step A, the spin coating conditions are: spin coating at 1000 rpm for 6-8 seconds, followed by spin coating at 2000 rpm for 30-60 seconds.

[0058] Preferably, in step A, the zirconium-based photoresist film is exposed using a femtosecond laser under the following conditions: scanning speed 5-10 mm / s, writing power 40-60 mW.

[0059] Preferably, in step A, the development is a two-stage development, with the primary developer being acetone or PGMEA and the primary development time being 30 seconds; the secondary developer is isopropanol (IPA) and the secondary development time is 60-90 seconds.

[0060] Preferably, in step A, the heating rate during annealing is 15°C / min, and the cooling rate is 2°C / min.

[0061] Preferably, in step B, the settling time after homogenization is 0.5-6 hours.

[0062] Preferably, in step C, the spin coating speed is 3000-8000 rpm and the spin time is 60-300 s.

[0063] Preferably, in step C, the heating reaction temperature is 70–120°C, and the reaction time is 10–96 h.

[0064] Preferably, in step C, the washing and drying are performed by thoroughly washing with methanol and then vacuum drying overnight at room temperature.

[0065] A schematic diagram of the femtosecond laser direct writing device used in this embodiment of the invention is shown below. Figure 12As shown, unless specific conditions are specified in the examples, they should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained through conventional technical means or commercially available.

[0066] Example 1:

[0067] (1) Weigh 8g zirconium methacrylate, 90g acetone and 120mg 7-diethylamino-3-thiophenecarboxycoumarin and place them in a brown glass bottle. After sonicating for 30min, filter with a 0.22μm needle filter to prepare zirconium-based photoresist.

[0068] (2) The synthesized zirconium-based photoresist was dropped onto a glass substrate and spin-coated at 1000 rpm for 8 s, followed by spin-coating at 2000 rpm for 30 s to obtain a zirconium-based photoresist film. Subsequently, a 780 nm femtosecond laser was used for photolithography at a scanning speed of 5 mm / s and a writing power of 40 mW. By reading the preset pattern and performing focused scanning, the monomers at specific locations underwent photopolymerization, achieving patterned writing. After writing, the film was developed in acetone for 30 s, then in isopropanol for 90 s, and dried at room temperature to obtain the etched pattern.

[0069] (3) The obtained zirconium-based photoresist pattern was placed in a muffle furnace and annealed for 2 hours in an air atmosphere at a temperature of 600°C, a heating rate of 15°C / min, and a cooling rate of 2°C / min. After annealing, a patterned ZrO2 film was obtained. Figure 1 The pattern is designed and the ZrO2 thin film pattern is annealed;

[0070] (4) Take 66 mg of organic ligand a and place it in a 5 mL reagent bottle. Then add 2 mL of DMF, dissolve by sonication, add 110 μL of triethylamine, homogenize with a homogenizer, and let stand for 2 h to obtain a gelled organic ligand solution.

[0071] (5) Place the patterned ZrO2 film obtained on a spin coater, add 2 mL of the gelled ligand solution prepared above, and spin coat at 6000 rpm for 200 s to obtain UiO-66 inorganic film precursor.

[0072] (6) The UiO-66 inorganic membrane precursor was then placed in a vacuum drying oven and heated at 80°C for 90 hours. After naturally cooling to room temperature, it was washed several times with methanol and then vacuum dried overnight at room temperature to obtain patterned UiO-66 inorganic thin films. Figure 2 , Figure 3 and Figure 4 The images show a schematic diagram of the UiO-66 material structure, an XRD pattern of a patterned UiO-66 film, and a SEM image of a patterned UiO-66 film. Figure 3As shown, the characteristic peaks in the XRD pattern of the prepared patterned thin film are basically consistent with the standard XRD pattern of UiO-66, indicating the successful preparation of the patterned UiO-66 thin film and its good crystallinity. Furthermore, Figure 4 The SEM images further demonstrate the successful preparation of uniform and dense micron-sized patterned UiO-66 films.

[0073] Compare with Example 1:

[0074] (1) The ZrO2 thin film patterned in the first three steps is the same as in Example 1;

[0075] (2) Weigh 66 mg of organic ligand a and dissolve it in a mixed solution of 7.2 mL H2O and 15.5 mL DMF. After sonication, transfer it to a 30 mL reaction vessel.

[0076] (3) The patterned ZrO2 film was then placed in the above solution and reacted at 120°C for 72 h. The reacted film was washed three times with methanol and dried overnight at room temperature to obtain the UiO-66 film. Figure 5 As shown, the UiO-66 thin film prepared by the traditional solvothermal method has obvious gaps.

[0077] Compare with Example 2:

[0078] (4) The ZrO2 thin film patterned in the first three steps is the same as in Example 1;

[0079] (5) Dissolve 66 mg of organic ligand a in 2 mL of DMF by sonication;

[0080] (3) Place the patterned ZrO2 film obtained on a spin coater, add 2 mL of the prepared ligand solution, and spin coat at 6000 rpm for 200 s to obtain UiO-66 inorganic film precursor.

[0081] (4) Subsequently, the UiO-66 inorganic film precursor was placed in a vacuum drying oven and heated at 80°C for 90 h. After naturally cooling to room temperature, it was washed several times with methanol, and then vacuum dried overnight at room temperature. The prepared UiO-66 inorganic film was characterized by XRD, as shown below. Figure 6 As shown, the prepared film did not exhibit the characteristic peaks corresponding to UiO-66.

[0082] Example 2:

[0083] (1) Weigh 10g zirconium acrylate, 120g PGMEA and 100mg 7-diethylamino-3-thiophenecarboxycoumarin and place them in a brown glass bottle. After sonicating for 30min, filter with a 0.22μm needle filter to prepare zirconium-based photoresist.

[0084] (2) The synthesized zirconium-based photoresist was dropped onto a glass substrate and spin-coated at 1000 rpm for 8 s, followed by spin-coating at 2000 rpm for 40 s to obtain a zirconium-based photoresist film. Subsequently, a 780 nm femtosecond laser was used for photolithography at a scanning speed of 5 mm / s and a writing power of 40 mW. By reading the preset pattern and performing focused scanning, the monomers at specific locations underwent photopolymerization, achieving patterned writing. After writing, the film was first developed in PGMEA for 30 s, then developed in isopropanol for 60 s, and dried at room temperature to obtain the etched pattern.

[0085] (3) The obtained zirconium-based photoresist pattern was placed in a muffle furnace and annealed for 3 hours in air atmosphere. The annealing temperature was 600℃, the heating rate was 15℃ / min, and the cooling rate was 2℃ / min. After annealing, a patterned ZrO2 film was obtained.

[0086] (4) Weigh 66 mg of organic ligand a and place it in a 5 mL reagent bottle. Then add 1.8 mL of DMF, sonicate to dissolve, add 70 μL of potassium hydroxide aqueous solution (50 wt%), homogenize with a homogenizer, and let stand for 3 h to obtain a gelled organic ligand solution.

[0087] (5) The patterned ZrO2 film was placed on a spin coater, and 1.8 mL of the above gelled ligand solution was added. The spin coater was operated at 6000 rpm for 240 s to obtain the UiO-66 inorganic film precursor.

[0088] (6) Subsequently, the UiO-66 inorganic membrane precursor was placed in a vacuum drying oven and heated at 100°C for 72 hours. After naturally cooling to room temperature, it was washed several times with methanol, and then vacuum dried overnight at room temperature to obtain the desired product. Figure 7 The patterned UiO-66 inorganic thin film shown.

[0089] Example 3:

[0090] (1) Weigh 10g zirconium acrylate, 100g PGMEA and 80mg 7-diethylamino-3-thiophenecarboxycoumarin and place them in a brown glass bottle. After sonicating for 30min, filter with a 0.22μm needle filter to prepare zirconium-based photoresist.

[0091] (2) The synthesized zirconium-based photoresist was dropped onto a glass substrate and spin-coated at 1000 rpm for 8 s, followed by spin-coating at 2000 rpm for 60 s to obtain a zirconium-based photoresist film. Subsequently, a 780 nm femtosecond laser was used for photolithography at a scanning speed of 8 mm / s and a writing power of 45 mW. By reading the preset pattern and performing focused scanning, the monomers at specific locations underwent photopolymerization, achieving patterned writing. After writing, the film was first developed in PGMEA for 30 s, then developed in isopropanol for 60 s, and dried at room temperature to obtain the etched pattern.

[0092] (3) The obtained zirconium-based photoresist pattern was placed in a muffle furnace and annealed for 4 hours in an air atmosphere at a temperature of 700℃, a heating rate of 15℃ / min, and a cooling rate of 2℃ / min. After annealing, a patterned ZrO2 film was obtained;

[0093] (4) Weigh 78 mg of organic ligand b into a 5 mL reagent bottle, then add 2.5 mL of DMF, dissolve by sonication, add 200 μL of triethylamine, homogenize with a homogenizer, and let stand for 3 h to obtain a gelled organic ligand solution.

[0094] (5) Place the patterned ZrO2 film obtained on a spin coater, add 2.5 mL of the gelled ligand solution prepared above, and spin coat at 8000 rpm for 240 s to obtain UiO-66-NH2 inorganic film precursor.

[0095] (6) The UiO-66-NH2 inorganic membrane precursor was then placed in a vacuum drying oven and heated at 100°C for 48 hours. After naturally cooling to room temperature, it was washed several times with methanol and then vacuum dried overnight at room temperature to obtain the patterned UiO-66-NH2 inorganic thin film. Figure 8 This indicates that the patterned UiO-66-NH2 film was successfully prepared and exhibits good crystallinity.

[0096] Example 4:

[0097] (1) Weigh 12g zirconium acrylate, 120g PGMEA and 100mg 7-diethylamino-3-thiophenecarboxycoumarin and place them in a brown glass bottle. After sonicating for 60min, filter with a 0.22μm needle filter to prepare zirconium-based photoresist.

[0098] (2) The synthesized zirconium-based photoresist was dropped onto a glass substrate and spin-coated at 1000 rpm for 8 s, followed by spin-coating at 2000 rpm for 90 s to obtain a zirconium-based photoresist film. Subsequently, a 780 nm femtosecond laser was used for photolithography at a scanning speed of 10 mm / s and a writing power of 50 mW. By reading the preset pattern and performing focused scanning, the monomers at specific locations underwent photopolymerization, achieving patterned writing. After writing, the film was developed in PGMEA for 30 s, then in isopropanol for 60 s, and dried at room temperature to obtain the etched pattern.

[0099] (3) The obtained zirconium-based photoresist pattern was placed in a muffle furnace and annealed for 4 hours in an air atmosphere at a temperature of 700℃, a heating rate of 15℃ / min, and a cooling rate of 2℃ / min. After annealing, a patterned ZrO2 film was obtained;

[0100] (4) Weigh 94 mg of organic ligand b into a 5 mL reagent bottle, then add 3 mL of DMF, dissolve by sonication, add 80 μL of potassium hydroxide aqueous solution (50%), homogenize with a homogenizer, and let stand for 5 h to obtain a gelled organic ligand solution.

[0101] (5) The patterned ZrO2 film was placed on a spin coater, and 3 mL of the above gelled ligand solution was added. The spin coater was operated at 8000 rpm for 240 s to obtain the UiO-66-NH2 inorganic film precursor.

[0102] (6) Subsequently, the UiO-66-NH2 inorganic membrane precursor was placed in a vacuum drying oven and heated at 110°C for 48 hours. After naturally cooling to room temperature, it was washed several times with methanol, and then vacuum dried overnight at room temperature to obtain the membrane precursor. Figure 9 The patterned UiO-66-NH2 inorganic thin film shown.

[0103] Example 5:

[0104] (1) Weigh 8g of zirconium methacrylate, 100g of PGMEA and 100mg of 7-diethylamino-3-thiophenecarboxycoumarin and place them in a brown glass bottle. After sonicating for 30 minutes, filter the solution with a 0.22μm needle filter to prepare zirconium-based photoresist.

[0105] (2) The synthesized zirconium-based photoresist was dropped onto a glass substrate and spin-coated at 1000 rpm for 6 s, then at 2000 rpm for 90 s to obtain a zirconium-based photoresist film. Subsequently, a 780 nm femtosecond laser was used for photolithography at a scanning speed of 10 mm / s and a writing power of 50 mW. By reading the preset pattern and performing focused scanning, the monomers at specific locations underwent photopolymerization, achieving patterned writing. After writing, the film was developed in PGMEA for 30 s, then in isopropanol for 60 s, and dried at room temperature to obtain the written pattern.

[0106] (3) The obtained zirconium-based photoresist pattern was placed in a muffle furnace and annealed for 2 hours in air atmosphere. The annealing temperature was 500℃, the heating rate was 15℃ / min, and the cooling rate was 2℃ / min. After annealing, a patterned ZrO2 film was obtained.

[0107] (4) Weigh 97 mg of organic ligand c and place it in a 5 mL reagent bottle. Then add 2.0 mL of DMF, dissolve by sonication, add 250 μL of triethylamine, homogenize with a homogenizer, and let stand for 3 h to obtain a gelled organic ligand solution.

[0108] (5) The patterned ZrO2 film was placed on a spin coater, and 2.0 mL of the above gelled ligand solution was added. The spin coater was rotated at 7500 rpm for 180 s to obtain the UiO-67 inorganic film precursor.

[0109] (6) The UiO-67 inorganic membrane precursor was then placed in a vacuum drying oven and heated at 100°C for 60 hours. After naturally cooling to room temperature, it was washed several times with methanol and then vacuum dried overnight at room temperature to obtain patterned UiO-67 inorganic thin films. Figure 10 This indicates that the patterned UiO-67 film was successfully prepared and exhibits good crystallinity.

[0110] Example 6:

[0111] (1) Weigh 8g of zirconium methacrylate, 100g of PGMEA and 100mg of 7-diethylamino-3-thiophenecarboxycoumarin and place them in a brown glass bottle. After sonicating for 30 minutes, filter the solution with a 0.22μm needle filter to prepare zirconium-based photoresist.

[0112] (2) The synthesized zirconium-based photoresist was dropped onto a glass substrate and spin-coated at 1000 rpm for 6 s, followed by spin-coating at 2000 rpm for 90 s to obtain a zirconium-based photoresist film. Subsequently, a 780 nm femtosecond laser was used for photolithography at a scanning speed of 5 mm / s and a writing power of 40 mW. By reading the preset pattern and performing focused scanning, the monomers at specific locations underwent photopolymerization, achieving patterned writing. After writing, the film was first developed in PGMEA for 30 s, then developed in isopropanol for 60 s, and dried at room temperature to obtain the etched pattern.

[0113] (3) The obtained zirconium-based photoresist pattern was placed in a muffle furnace and annealed for 2 hours in air atmosphere. The annealing temperature was 500℃, the heating rate was 15℃ / min, and the cooling rate was 2℃ / min. After annealing, a patterned ZrO2 film was obtained.

[0114] (4) Weigh 97 mg of organic ligand c and place it in a 5 mL reagent bottle. Then add 2.2 mL of DMF, sonicate to dissolve, and add 70 μL of potassium hydroxide aqueous solution (50%). After homogenizing with a homogenizer, let stand for 4 h to obtain a gelled organic ligand solution.

[0115] (5) The patterned ZrO2 film was placed on a spin coater, and 2.2 mL of the above gelled ligand solution was added. The spin coater was rotated at 7500 rpm for 180 s to obtain the UiO-67 inorganic film precursor.

[0116] (6) Subsequently, the UiO-67 inorganic membrane precursor was placed in a vacuum drying oven and heated at 110°C for 72 hours. After naturally cooling to room temperature, it was washed several times with methanol, and then vacuum dried overnight at room temperature to obtain the desired product. Figure 11 The patterned UiO-67 inorganic thin film shown.

Claims

1. A method for preparing patterned UiO series inorganic films based on femtosecond laser direct writing, characterized in that: The preparation method includes the following steps: A: Preparation of patterned ZrO2 thin films: A zirconium-based photoresist was prepared by mixing a photoinitiator, a zirconium-based monomer, and a solvent in a certain proportion. After filtration, the photoresist was dropped onto a glass substrate and a zirconium-based photoresist film was prepared by spin coating. The zirconium-based photoresist film was then exposed to a preset pattern using a femtosecond laser and subsequently developed to obtain a photoresist pattern. Finally, the photoresist pattern was placed in a muffle furnace and annealed at 500-700 °C for 2-4 h in an air atmosphere to prepare a patterned ZrO2 film. B: Preparation of gelled ligand solutions for UiO series inorganic membranes: The organic ligand and regulator are dissolved in N,N-dimethylformamide, dissolved by sonication, homogenized on a gel coater, and allowed to stand for 0.5-6 h to obtain a gelled ligand solution; the regulator is triethylamine or potassium hydroxide; the organic ligand is one of the following compounds ac; the molar ratio of the organic ligand, regulator and N,N-dimethylformamide is 1:2~5:50~90; C: Preparation of UiO series inorganic membranes: The patterned ZrO2 thin film containing a glass substrate obtained in step A is placed on a spin coater, and an appropriate amount of gelling ligand solution is added. The UiO series inorganic film precursor is obtained by spin coating. The inorganic film precursor is placed in a vacuum drying oven and heated to react. The film after reaction is washed and dried to obtain the patterned UiO series inorganic film.

2. The preparation method according to claim 1, characterized in that: In step A, the zirconium monomer is zirconium acrylate, zirconium methacrylate, or a mixture thereof, the initiator is 7-diethylamino-3-thiophenecarboxycoumarin, and the solvent is propylene glycol methyl ether acetate, acetone, or a mixture thereof.

3. The preparation method according to claim 1 or 2, characterized in that: In step A, the zirconium-based photoresist contains zirconium-based monomers accounting for 2-10% of the solvent mass and initiators accounting for 0.2-2.5% of the zirconium-based monomer mass.

4. The preparation method according to claim 1, characterized in that: In step A, the zirconium-based photoresist film is exposed using a femtosecond laser under the following conditions: scanning speed 5-10 mm / s, writing power 40-60 mW.

5. The preparation method according to claim 1, characterized in that: In step A, the development is a two-stage development. The primary developer is acetone or propylene glycol methyl ether acetate, and the primary development time is 30 seconds. The secondary developer is isopropanol, and the secondary development time is 60-90 seconds.

6. The preparation method according to claim 1, characterized in that: In step A, the heating rate during annealing is 15℃ / min, and the cooling rate is 2℃ / min.

7. The preparation method according to claim 1, characterized in that: In step C, the heating reaction temperature is 70~120℃, and the reaction time is 10~96 h.

8. A gelled ligand solution for preparing UiO series inorganic membranes, characterized in that: The gelled ligand solution is prepared by the following method: dissolving an organic ligand and a modifier in N,N-dimethylformamide, dissolving by sonication, homogenizing on a gel coater, and allowing it to stand for 0.5-6 h to obtain the gelled ligand solution; the modifier is triethylamine or potassium hydroxide; the organic ligand is one of the following compounds ac; the molar ratio of the organic ligand, modifier, and N,N-dimethylformamide is 1:2~5:50~90; 。 9. The gelled ligand solution as described in claim 8, characterized in that: The gelled ligand solution is used to prepare UiO series inorganic films by the following method: a patterned ZrO2 film containing a glass substrate is placed on a spin coater, an appropriate amount of gelled ligand solution is added, and the rotation speed and rotation time are controlled to prepare a UiO series inorganic film precursor; the above inorganic film precursor is placed in a vacuum drying oven for heating and reaction, and the film after reaction is washed and dried to obtain the patterned UiO series inorganic film.

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