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KR-20260066864-A - Core-shell Microsphere and Method for Removing Gaseous Formaldehyde Using the Same

KR20260066864AKR 20260066864 AKR20260066864 AKR 20260066864AKR-20260066864-A

Abstract

The present disclosure describes a microsphere comprising copper hydroxysulfate (CHS) as a core and MOF-199 (M199) as a cell layer, and a technology that uses this as an adsorbent to effectively remove FA contained in a gaseous medium such as the atmosphere or indoor air.

Inventors

  • 김기현
  • 김원기
  • 임대환
  • 비크란트 쿠마르
  • 트란 티 옌

Assignees

  • 한양대학교 산학협력단

Dates

Publication Date
20260512
Application Date
20241105

Claims (20)

  1. A core comprising copper hydroxysulfate (CHS), and A cell layer comprising MOF-199, formed in-situ on the above core. Microspheres with a core-cell structure for adsorbing gaseous FA, including
  2. A microsphere with a core-cell structure according to claim 1, characterized in that the diameter of the microsphere with the core-cell structure is in the range of 1 to 5 μm, and the diameter of the core is in the range of 0.5 to 3.5 μm.
  3. A microsphere with a core-cell structure according to claim 2, characterized in that the volume ratio of the core to the cell layer within the microsphere with the core-cell structure is in the range of 1:1.1 to 2.
  4. A microsphere with a core-cell structure according to claim 1, characterized in that the microsphere with the core-cell structure exhibits porosity, wherein the average pore diameter is in the range of 0.5 to 3 nm.
  5. In claim 4, the core-cell structured microsphere is characterized by exhibiting a BET specific surface area of at least 1100 m² g⁻¹ and a pore volume of 0.4 to 0.8 cm³ g⁻¹ when measured by BET analysis.
  6. In claim 5, the specific surface area of the microsphere of the core-cell structure is at least 31% higher than the specific surface area of M199 alone, and A microsphere with a core-cell structure characterized in that the pore volume of the microsphere with the core-cell structure is at least 35% higher than the pore volume of M199 alone.
  7. The microsphere of the core-shell structure according to claim 1, characterized in that, when measured by XPS, the microsphere of the core-shell structure comprises, on an elemental basis, 0.5 to 1.2 wt% sulfur (S), 50 to 65 wt% carbon (C), 0.1 to 0.5 wt% nitrogen (N), 28 to 40 wt% oxygen (O), and 5 to 10 wt% copper (Cu).
  8. A microsphere with a core-cell structure according to claim 1, characterized in that the microsphere with the core-cell structure exhibits a partition coefficient (PC) of at least 0.25 mol kg⁻¹ Pa⁻¹ based on 100% BT when adsorbed to gaseous FA.
  9. In claim 8, the core-cell structured microsphere is characterized by exhibiting a breakthrough volume (BTV) of at least 2500 L atm g⁻¹ based on 100% BT when adsorbed to gaseous FA.
  10. In claim 9, the core-cell structured microsphere is characterized by exhibiting an adsorption capacity (capacity; Q) of at least 70 mg g - 1 based on 100% BT when adsorbed to gaseous FA.
  11. a) a step of forming a copper hydroxysulfate (CHS) template by reacting a water-soluble copper precursor compound and an amine-based compound in an aqueous medium; and b) a step of reacting copper ions in the CHS template with an organic ligand to form a cell layer containing MOF-199 in-situ using the CHS template as a core; A method for manufacturing a core-shell structured microsphere for adsorbing gaseous formaldehyde (FA), comprising
  12. In Paragraph 11, In step a) above, the reaction temperature is controlled within the range of 15 to 40°C, and A method for manufacturing a core-shell structured microsphere, characterized in that the reaction temperature in step b) above is controlled within the range of 15 to 40℃.
  13. A method for manufacturing a core-shell structured microsphere according to claim 11, wherein the copper precursor compound is at least one selected from the group consisting of copper(II) sulfate ( CuSO₄ ), brochantite ( Cu₄ (OH) ₆SO₄ ), copper(II) thiosulfate ( CuS₂O₃ ), copper(II) sulfide (CuS), copper(I) sulfide ( Cu₂S ), copper(I) sulfate ( Cu₂SO₄ ), and hydrates thereof.
  14. A method for manufacturing a core-shell structured microsphere according to claim 11, wherein the amine compound is at least one selected from the group consisting of propanediamine (DPA), ethylenediamine (EDA), triethylenetetramine (TETA), diethylenetriamine (DETA), hexamethylenetetramine (HMTA), tetramethylethylenediamine (TMEDA), and polyethyleneimine (PEI).
  15. A method for manufacturing a core-shell structured microsphere according to claim 11, characterized in that the organic ligand is benzene-1,3,5-tricarboxylic acid (BTC).
  16. A step of contacting a gaseous medium containing formaldehyde (FA) with an adsorbent comprising a core-shell structured microsphere according to any one of claims 1 to 10; A method for removing formaldehyde including
  17. A method for removing formaldehyde according to claim 16, characterized in that the gaseous medium is the atmosphere.
  18. A method for removing formaldehyde according to claim 16, characterized in that the contact temperature between the gaseous medium and the adsorbent is in the range of 15 to 40°C.
  19. A method for removing formaldehyde according to claim 16, characterized in that the humidity of the gaseous medium is 80% or less.
  20. A method for removing formaldehyde according to claim 16, characterized in that the concentration of the gaseous medium FA is at least 40 ppm (4 Pa).

Description

Core-shell Microsphere and Method for Removing Gaseous Formaldehyde Using the Same The present disclosure relates to a core-shell structured microsphere and a method for removing gaseous formaldehyde (FA) using the same. More specifically, the present disclosure relates to a microsphere comprising a copper hydroxysulfate (CHS) template as a core and a MOF-199 (M199) metal-organic framework (MOF) as a cell layer, and a method for effectively removing FA present in a gaseous medium such as the atmosphere or indoor air using the microsphere as an adsorbent. Due to the emergence of environmental rights demanding a pleasant environment in human life and the strengthening of policies or institutional regulations to support them, effective control of environmental pollution is emerging as a critical issue in urbanized and industrialized societies. The formation of large-scale industrial areas and large cities resulting from urbanization and industrialization is causing an increase in various air pollutants, such as nitrogen oxides (NOx), sulfur oxides (SOx), hydrocarbons (e.g., monocyclic or polycyclic aromatic hydrocarbons), and volatile organic compounds (VOCs). In particular, volatile organic compounds (VOCs) are one of the indoor air pollutants that cause serious health problems for humans. Among these, FAs are VOCs widely present in indoor air; even short-term exposure to concentrations above a certain level (0.1 ppm or higher) can cause mucosal irritation, headaches, dizziness, and irritation to the eyes and skin, and they are known as the main causative agents of various diseases such as sick building syndrome and sick building syndrome. In particular, exposure to chronic or abnormally high concentrations can cause cancer, and the International Agency for Research on Cancer (IARC) has classified FAs as a Group 1 carcinogen. Major sources of FA in indoor air include household products (e.g., paint, adhesives, wood, candles, detergents, etc.), combustion processes, and building materials. While FA concentrations in indoor air are typically at the ppb or sub-ppm level, emissions from certain industries (e.g., pesticides, textiles, synthetic leather processing, etc.) can reach hundreds of ppm. In particular, as people's lifestyles increasingly take place indoors, interest in and the importance of indoor air quality control technologies are rapidly growing. Therefore, it is crucial to effectively remove FA from indoor air and industrial emissions. As a solution to this, technologies for removing FA have been developed, such as thermal catalytic oxidation, photocatalytic oxidation, and adsorption; however, considering efficiency, simplicity, low energy requirements, flexibility, and low cost, the adsorption method is the most widely applied. However, when using conventional adsorbents (e.g., zeolites, biochar, activated carbon (AC), etc.), it is difficult to effectively remove FA due to low adsorption capacity resulting from the properties of FA. Several studies have developed various types of functional materials, such as MOFs and their derivatives, which possess controllable pore networks and highly porous crystal structures. For example, Cu-MOFs (e.g., M199) can effectively adsorb FA molecules by utilizing surface chemistry and pore structure (Environ. Res. 2019, 168, 96). Despite the aforementioned advantages, MOFs face limitations in widespread application due to high cost, low scalability, high energy consumption, low stability, and the use of hazardous solvents. Therefore, there is a need for functional adsorbents capable of overcoming the disadvantages of conventional technology. FIG. 1 shows the N2 adsorption-desorption isotherms of CHS@M199, the CHS template, and M199, respectively; Figure 2 shows the Fourier-transform infrared (FTIR) analysis results for CHS@M199, CHS template, and M199, respectively; Figure 3 shows the PXRD (Powder X-ray diffraction) analysis results of CHS@M199, CHS template, and M199, respectively; Figure 4 shows the XPS spectra of CHS@M199, the CHS template, and M199, respectively; Figure 5 shows the XPS core-level fitting values for the surface elements of CHS; Figure 6 shows XPS core-level fitting values for surface elements of CHS@M199; Figure 7 shows XPS core-level fitting values for surface elements of M199; Figure 8 shows FESEM (Field-emission scanning electron microscope) images of CHS@M199, CHS template, and M199, respectively; Figure 9 is a TEM (Transmission Electron Microscopy) image of the CHS template and CHS@M199, respectively; Figure 10 is a graph showing the experimental results (C out /C in ) of FA adsorption performance for CHS@M199, CHS template, M199, and AC, respectively (FA concentration: 10 Pa, adsorbent mass = 5 mg, flow rate = 230 mL min ⇌ 1 , relative humidity (RH) = 0.016%); Figure 11 shows the results (BT) evaluating the FA adsorption performance of CHS@M199 according to the inflow concentration (partial pressure); FIG. 12 is a graph showing the BT behavi