A core-shell type material for separating fluorine-containing electronic special gas and a preparation method thereof
By preparing a core-shell structured PSD@HKUST-1 composite material, the problems of insufficient selectivity and stability of traditional separation materials in the separation of fluorine-containing electronic special gases were solved, achieving a high-efficiency and low-energy-consumption separation effect, which is suitable for applications in the semiconductor and flat panel display fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FUZHOU UNIV
- Filing Date
- 2026-04-18
- Publication Date
- 2026-05-26
AI Technical Summary
In existing technologies, traditional separation materials such as molecular sieves and activated carbon have poor selectivity, limited adsorption capacity, and poor mechanical stability in the separation of fluorine-containing electronic special gases, which cannot meet the high precision and low energy consumption requirements of the semiconductor industry.
Polystyrene-divinylbenzene microspheres (PSD) were prepared by emulsion polymerization as the core, and HKUST-1 shells were grown in situ under low temperature conditions to form a core-shell composite material, which enhances mechanical strength and pore structure, and achieves efficient adsorption and highly selective separation of fluorinated electronic specialty gases such as SF6 and CF4.
It achieves efficient adsorption and highly selective separation of fluorine-containing electronic specialty gases such as SF6 and CF4. The material has good structural stability and is suitable for the recovery and purification of electronic specialty gases in the semiconductor and flat panel display fields, reducing energy consumption and operating costs.
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Figure CN122076409A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of gas separation and purification technology, specifically relating to a core-shell material for the separation of fluorine-containing electronic special gases and its preparation method. Background Technology
[0002] Fluorinated electronic specialty gases SF6 and CF4 are indispensable core materials in high-tech fields such as semiconductor manufacturing and flat panel displays. They are widely used in key processes such as chip etching, device cleaning, and thin film deposition. Their purity directly affects the performance and yield of electronic devices, therefore, efficient recovery and deep purification are necessary after use. Furthermore, these gases have a strong greenhouse effect; leaks and uncontrolled emissions can cause serious and lasting damage to the global ecosystem. Achieving efficient separation and recovery is both an inevitable requirement for industry development and an important measure for environmental governance.
[0003] Currently, the separation and purification technology for fluorine-containing electronic specialty gases still faces many bottlenecks, making it difficult to meet the industry's application requirements for high precision, low energy consumption, and high stability. Traditional separation methods utilize materials such as molecular sieves and activated carbon, which suffer from poor separation selectivity, limited adsorption capacity, and poor regeneration performance. This not only leads to low specialty gas recovery efficiency and insufficient purification precision but also results in high energy consumption and high operating costs, making them unsuitable for the stringent standards of specialty gas separation in the semiconductor industry.
[0004] Metal-organic frameworks (MOFs), as novel porous functional materials, have shown broad application prospects in the separation of fluorinated electronic specialty gases due to their tunable pore structure, abundant active adsorption sites, and adjustable surface chemistry. Among them, HKUST-1, a typical MOF material, exhibits excellent adsorption selectivity for fluorinated specialty gases such as SF6 and CF4 due to its unique pore structure and abundant active sites, making it a research hotspot for fluorinated specialty gas separation materials. However, HKUST-1 alone has significant application drawbacks, such as poor mechanical stability and easy aggregation. In practical industrial applications, it is susceptible to structural damage and performance degradation due to factors such as airflow impact and temperature changes, failing to balance excellent separation performance with stable structural characteristics, severely limiting its industrial promotion and application.
[0005] Therefore, in order to address the shortcomings of existing technologies for separating fluorine-containing electronic specialty gases, research on the modification of HKUST-1 materials was conducted to develop composite adsorption materials with simple processing and excellent performance. This has important industrial application value and ecological and environmental significance for achieving high-precision separation and efficient recovery of electronic specialty gases and meeting the development needs of the semiconductor industry. Summary of the Invention
[0006] The purpose of this invention is to provide a core-shell material for efficient separation of fluorine-containing electronic specialty gases and its preparation method. Monodisperse polystyrene-divinylbenzene microspheres (PSD) are prepared by emulsion polymerization, and then HKUST-1 shell is grown in situ under low-temperature controlled conditions using PSD microspheres as the core to obtain a core-shell structured composite material. This solves the problems of low selectivity and poor recovery and purification effect of traditional materials for fluorine-containing electronic specialty gas / nitrogen mixtures.
[0007] To achieve the above objectives, the present invention adopts the following technical solution:
[0008] In a first aspect, the present invention provides a method for preparing a core-shell material for the separation of fluorine-containing electronic special gases, comprising the following steps:
[0009] (1) Polyvinylpyrrolidone was dissolved in anhydrous ethanol to obtain a first solution, and azobisisobutyronitrile was dissolved in styrene to obtain a second solution; the first solution and the second solution were mixed and stirred at 65-75°C for 18-30 h under nitrogen; after the reaction was completed, the mixture was cooled, centrifuged, washed and dried to obtain polystyrene seed microspheres;
[0010] (2) Polystyrene seed microspheres and dibutyl phthalate were dispersed in sodium dodecyl sulfate aqueous solution, and the above solutions were mixed and swollen at 25-35°C for 18-30 h; then benzoyl peroxide, divinylbenzene and styrene were dispersed in sodium dodecyl sulfate aqueous solution and added, and swollen at 25-35°C for 18-30 h.
[0011] (3) Add a polyvinyl alcohol solution with a mass concentration of 8-12 wt% to the reaction system of step (2), and stir the reaction at 65-75℃ for 18-30 h under nitrogen. After the reaction is completed, PSD microspheres with regular structure and uniform particle size are obtained by centrifugation, washing and drying as the core.
[0012] (4) PSD microspheres, copper nitrate trihydrate and polyvinylpyrrolidone were dissolved in methanol to obtain solution A, and trimesic acid was dissolved in methanol to obtain solution B. The two solutions were mixed and reacted at low temperature for 20-28 h. The reaction product was centrifuged, washed and dried to obtain PSD@HKUST-1 core-shell material.
[0013] Furthermore, in step (1), the mass ratio of polyvinylpyrrolidone, anhydrous ethanol, azobisisobutyronitrile and styrene is (1-2):(70-90):(0.3-0.6):(10-20).
[0014] Furthermore, the ratio of polystyrene seed microspheres, dibutyl phthalate, benzoyl peroxide, divinylbenzene, styrene, and polyvinyl alcohol solution is 1~2g: 3~6mL: 0.5~1g: 3~6mL: 2~4mL: 20~30mL.
[0015] Furthermore, the mass concentration of the sodium dodecyl sulfate aqueous solution in step (2) is 0.30–0.45 wt%.
[0016] Furthermore, in step (4), the mass ratio of PSD microspheres, copper nitrate trihydrate, polyvinylpyrrolidone and pyromellitic acid is 1: (8~10): (4~5): (3~5).
[0017] Furthermore, the low temperature mentioned in step (4) is 0 to 10°C. At low temperature, HKUST-1 grows uniformly in situ on the surface of PSD microspheres and forms a complete shell. The low temperature reaction can effectively inhibit particle aggregation and ensure that the shell is continuous and uniform.
[0018] Secondly, the present invention provides a PSD@HKUST-1 core-shell material prepared by the above preparation method.
[0019] Thirdly, the present invention provides an adsorbent material comprising the above-mentioned PSD@HKUST-1 core-shell material.
[0020] Fourthly, the present invention provides the application of the above-mentioned PSD@HKUST-1 core-shell material or the above-mentioned adsorbent material in the adsorption and / or separation of fluorine-containing electronic special gases, characterized in that: the fluorine-containing electronic special gases are CF4 and SF6.
[0021] Fifthly, the present invention provides the application of the above-mentioned PSD@HKUST-1 core-shell material or the above-mentioned adsorbent material in the separation of CF4 / N2 and / or SF6 / N2.
[0022] The PSD@HKUST-1 core-shell composite material prepared in this invention uses PSD microspheres as the core. PSD possesses a regular pore structure, excellent mechanical strength, and good dispersibility, and its preparation process is mature and cost-controllable. Using PSD as the core provides excellent mechanical strength and structural stability, while the mesopores enhance mass transfer efficiency, effectively improving the defects of pure HKUST-1 such as easy aggregation and structural fragility. The HKUST-1 shell layer grown in situ on the surface of the PSD microspheres provides abundant open metal sites and an ordered pore structure, exhibiting specific recognition of fluorine-containing electronic specialty gases such as SF6 and CF4, significantly improving adsorption capacity and separation selectivity, and achieving efficient and precise separation of fluorine-containing gas / nitrogen mixed systems. This material combines structural stability and high-efficiency adsorption performance, making it suitable for electronic specialty gas recovery, high-purity purification, and tail gas treatment in fields such as semiconductors and flat panel displays.
[0023] The beneficial effects of this invention are as follows:
[0024] (1) PSD@HKUST-1 core-shell composite material was prepared by emulsion polymerization combined with low temperature in situ growth process. The preparation method is simple, highly controllable, and the reaction conditions are mild. It does not require complex equipment, which is convenient for industrial scale-up production and reduces the cost of practical application.
[0025] (2) The core-shell structure design with PSD microspheres as the core and HKUST-1 as the shell takes into account both structural stability and adsorption and separation performance. It utilizes the excellent mechanical strength of PSD microspheres to solve the defects of pure HKUST-1 such as easy agglomeration, fragile structure and fast performance decay. It also utilizes the rich active adsorption sites and adjustable pore structure of HKUST-1 to achieve efficient adsorption and high selective separation of fluorine-containing electronic special gases such as SF6 and CF4, effectively solving the problem of imbalance between adsorption capacity and selectivity of traditional materials.
[0026] (3) Applying PSD@HKUST-1 core-shell composite material to the field of fluorine-containing electronic special gas separation overcomes the shortcomings of traditional separation materials such as poor selectivity, high energy consumption and poor regeneration performance. The resulting material has a stable structure, excellent porosity, and good recyclability, which can reduce the actual loss in the application process. Attached Figure Description
[0027] Figure 1 The images are (a) XRD patterns, (b) SEM images of the PSD, PSD@HKUST-1-0 and PSD@HKUST-1-10 of the present invention, and (c, d) TEM-EDS images of the PSD@HKUST-1-0 and PSD@HKUST-1-10.
[0028] Figure 2 The adsorption-desorption curves and pore size distributions of the PSD, PSD@HKUST-1-0 and PSD@HKUST-1-10 of this invention at 77K are shown in (a) and (b) respectively.
[0029] Figure 3 The adsorption curves of the single components of PSD, PSD@HKUST-1-0 and PSD@HKUST-1-10 of the present invention at 298 K are (a) N2, (b) CF4 and (c) SF6.
[0030] Figure 4 The present invention describes the separation selectivity of PSD, PSD@HKUST-1-0 and PSD@HKUST-1-10 for (a) CF4 / N2 and (b) SF6 / N2.
[0031] Figure 5This is a GC separation curve of (ac)CF4 / N2 and (df)SF6 / N2 of PSD, PSD@HKUST-1-0 and PSD@HKUST-1-10 under multiple cyclic tests.
[0032] Figure 6 This is the XRD pattern of the PSD@HKUST-1-0 of this invention after GC cycle testing and three months of storage. Detailed Implementation
[0033] To further understand the present invention, the embodiments of the present invention are described below in conjunction with the accompanying drawings. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention.
[0034] In the following embodiments, the polyvinylpyrrolidone is of type K30 with a molecular weight of approximately 40,000-60,000; the polyvinyl alcohol is of type 1788 with an average degree of polymerization of 1650-1850 and a degree of alcoholysis of approximately 87.0-89.0%.
[0035] Comparative Example 1: PSD Microspheres
[0036] 1.5 g of polyvinylpyrrolidone was weighed and added to 80 g of anhydrous ethanol, and 0.44 g of azobisisobutyronitrile was added to 15 g of styrene. Both solutions were dissolved separately by sonication, and then added together to a three-necked flask. N2 was bubbled through the flask for 15 min. The temperature was then raised to 70 °C, and the reaction was mechanically stirred at 300 rpm for 24 h. After the reaction was complete, the mixture was cooled to room temperature and centrifuged. The resulting precipitate was washed three times each with anhydrous ethanol and water (centrifuged at 2500 rpm), and then dried in a vacuum drying oven at room temperature to obtain polystyrene (PS) seed microspheres.
[0037] In a three-necked flask, 1.3 g of PS seed microspheres and 50 mL of sodium dodecyl sulfate aqueous solution (0.375 wt%) were added and ultrasonically dispersed until homogeneous. 5 mL of dibutyl phthalate was added to 100 mL of sodium dodecyl sulfate aqueous solution (0.375 wt%), ultrasonically dispersed, and then added to the three-necked flask with stirring at 300 rpm. The mixture swelled at 30 ℃ for 24 h. Separately, 0.6 g of benzoyl peroxide, 5 mL of divinylbenzene (DVB), and 3 mL of styrene were added to 150 mL of sodium dodecyl sulfate aqueous solution (0.25 wt%), ultrasonically dispersed, and then added to the three-necked flask with stirring at 300 rpm. The mixture swelled at 30 ℃ for 24 h. Subsequently, 25 mL of polyvinyl alcohol aqueous solution (10 wt%) was added to the three-necked flask, and the mixture was purged with N2 for 30 min. The stirring speed was adjusted to 120 rpm, and the reaction was carried out at 70 ℃ for 24 h. The product was washed by centrifugation at 2000 rpm with anhydrous ethanol and ultrapure water, and then dried under vacuum at room temperature to obtain PSD microspheres.
[0038] Example 1 PSD@HKUST-1-0
[0039] 0.4 g of PSD microspheres (prepared in Comparative Example 1), 3.6 g of copper nitrate trihydrate, and 1.7 g of polyvinylpyrrolidone were ultrasonically dissolved in 200 mL of methanol to obtain solution A; separately, 1.72 g of trimesic acid was ultrasonically dissolved in 200 mL of methanol to obtain solution B. Solutions A and B were mixed thoroughly and reacted at 0 °C for 24 h with stirring. The product was washed three times by centrifugation with methanol at 6000 rpm and dried under vacuum at 70 °C to obtain PSD@HKUST-1-0.
[0040] Example 2 PSD@HKUST-1-10
[0041] 0.4 g of PSD microspheres, 3.6 g of copper nitrate trihydrate, and 1.7 g of polyvinylpyrrolidone were dissolved in 200 mL of methanol to obtain solution A; 1.72 g of trimesic acid was dissolved in 200 mL of methanol to obtain solution B. Solutions A and B were mixed thoroughly and reacted at 10 °C for 24 h with stirring. The product was washed three times by centrifugation with methanol at 6000 rpm and dried under vacuum at 70 °C to obtain PSD@HKUST-1-10.
[0042] Figure 1 The crystal structure and morphology of PSD microspheres, PSD@HKUST-1-0, and PSD@HKUST-1-10 were characterized. The surface of the PSD microspheres is wrinkled, which is conducive to the successful growth of HKUST-1 on its surface, and the shell thickness of PSD@HKUST-1-0 is greater than that of PSD@HKUST-1-10.
[0043] Figure 2 The adsorption-desorption curves of PSD microspheres, PSD@HKUST-1-0, and PSD@HKUST-1-10 at 77 K and N2 are shown, along with the pore size distribution of each material. The specific surface area of PSD is 33 m² / g. 2 / g, the specific surface areas of PSD@HKUST-1-0 and PSD@HKUST-1-10 are 64 m² / g and 64 m² / g, respectively. 2 / g and 98 m 2 / g. The pore size distribution within the micropore range was calculated using a nonlocal density functional theory model, PSD@HKUST-1-10 (0.12-0.41 cm). 3 g -1 It has a greater number of pores in the 11.4-14.3 Å range, which can be used to capture gases and has a higher SF6 adsorption capacity.
[0044] Figure 3 The adsorption capacities of PSD microspheres, PSD@HKUST-1-0, and PSD@HKUST-1-10 for N2, CF4, and SF6 at 298 K are shown. Compared to PSD microspheres, PSD@HKUST-1-0 and PSD@HKUST-1-10 show significantly improved single-component adsorption capacities for SF6 and CF4.
[0045] Figure 4 The potential separation capabilities of PSD microspheres, PSD@HKUST-1-0, and PSD@HKUST-1-10 for CF4 / N2 (v / v=70 / 30) and SF6 / N2 (v / v=70 / 30) were evaluated. PSD@HKUST-1-10 exhibited the best CF4 / N2 separation selectivity, while PSD@HKUST-1-0 showed the best SF6 / N2 separation selectivity. Furthermore, both PSD@HKUST-1-0 and PSD@HKUST-1-10 demonstrated significantly improved separation selectivity compared to PSD microspheres.
[0046] PSD microspheres, PSD@HKUST-1-0, and PSD@HKUST-1-10 materials were packed into separation columns, respectively. The separation test conditions for CF4 / N2 (v / v=70 / 30) mixed gases were set as follows: column temperature 30℃, mixed gas flow rate 50 mL / min; the separation test conditions for SF6 / N2 (v / v=70 / 30) mixed gases were set as follows: column temperature 40℃, mixed gas flow rate 90 mL / min. The separation effect of each material on the two mixed gases was detected and recorded using gas chromatography. The differences in separation performance between PSD microspheres and PSD@HKUST-1-0 and PSD@HKUST-1-10 were compared and analyzed. The results are as follows: Figure 5As shown, the actual separation performance of PSD@HKUST-1-0 and PSD@HKUST-1-10 was greatly improved. After the above separation test was completed, the material was recovered and placed in a vacuum drying oven, and heated at 90℃ for 2 h. The treated material was then repacked into the separation column, and the above separation test steps were repeated for a total of 3 cycles. The results of gas chromatography detection showed that after 3 cycles, the peak shape, resolution, and retention time did not change significantly, and the material still maintained excellent separation performance and good cycling stability.
[0047] Figure 6 The XRD pattern of PSD@HKUST-1-0 after three GC cycles and three months of storage shows that PSD@HKUST-1-0 has excellent structural stability and recyclability.
[0048] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.
Claims
1. A method for preparing a core-shell material for the separation of fluorine-containing electronic special gases, characterized in that: Includes the following steps: (1) Polyvinylpyrrolidone was dissolved in anhydrous ethanol to obtain a first solution, and azobisisobutyronitrile was dissolved in styrene to obtain a second solution; the first solution and the second solution were mixed and stirred at 65-75°C for 18-30 h under nitrogen; after the reaction was completed, the mixture was cooled, centrifuged, washed and dried to obtain polystyrene seed microspheres; (2) Polystyrene seed microspheres and dibutyl phthalate were dispersed in sodium dodecyl sulfate aqueous solution, and the above solutions were mixed and swollen at 25-35°C for 18-30 h; then benzoyl peroxide, divinylbenzene and styrene were dispersed in sodium dodecyl sulfate aqueous solution and added, and swollen at 25-35°C for 18-30 h. (3) Add a polyvinyl alcohol solution with a mass concentration of 8-12 wt% to the reaction system of step (2), and stir the reaction at 65-75℃ for 18-30 h under nitrogen. After the reaction is completed, PSD microspheres are obtained by centrifugation, washing and drying. (4) PSD microspheres, copper nitrate trihydrate and polyvinylpyrrolidone were dissolved in methanol to obtain solution A, and trimesic acid was dissolved in methanol to obtain solution B. The two solutions were mixed and reacted at low temperature for 20-28 h. The reaction product was centrifuged, washed and dried to obtain PSD@HKUST-1 core-shell material.
2. The preparation method according to claim 1, characterized in that: In step (1), the mass ratio of polyvinylpyrrolidone, anhydrous ethanol, azobisisobutyronitrile and styrene is (1-2): (70-90): (0.3-0.6): (10-20).
3. The preparation method according to claim 1, characterized in that: The ratio of polystyrene seed microspheres, dibutyl phthalate, benzoyl peroxide, divinylbenzene, styrene, and polyvinyl alcohol solution is 1~2g: 3~6mL: 0.5~1g: 3~6mL: 2~4mL: 20~30mL.
4. The preparation method according to claim 1, characterized in that: The mass concentration of sodium dodecyl sulfate aqueous solution in step (2) is 0.30–0.45 wt%.
5. The preparation method according to claim 1, characterized in that: In step (4), the mass ratio of PSD microspheres, copper nitrate trihydrate, polyvinylpyrrolidone and pyromellitic acid is 1: (8~10): (4~5): (3~5).
6. The preparation method according to claim 1, characterized in that: The low temperature mentioned in step (4) is 0 to 10°C.
7. A PSD@HKUST-1 core-shell material prepared by the preparation method according to any one of claims 1-6.
8. An adsorbent material, characterized in that: It contains the PSD@HKUST-1 core-shell material as described in claim 7.
9. The application of the PSD@HKUST-1 core-shell material as described in claim 7 or the adsorbent material as described in claim 8 in the adsorption and / or separation of fluorine-containing electronic specialty gases, characterized in that: The fluorine-containing electronic specialty gases are CF4 and SF6.
10. The application of the PSD@HKUST-1 core-shell material as described in claim 7 or the adsorbent material as described in claim 8 in the separation of CF4 / N2 and / or SF6 / N2.