Surface imprinted membranes with core-shell structure, methods of making and use thereof

Abstract

The application discloses a preparation method of a surface imprinting film with a core-shell structure, and comprises the following steps: (1) preparing a surface imprinting material with a core-shell structure; and (2) preparing a surface imprinting film with a core-shell structure. The application further discloses the surface imprinting film with the core-shell structure and application. The surface imprinting film with the core-shell structure of the application uses a virtual template molecule to replace a damascone molecule to prepare the imprinting film, and solves the problems of few imprinting sites, low imprinting efficiency and inaccurate cavities caused by single active sites of the damascone molecule.

Description

Technical Field

[0001] This invention belongs to the field of materials, specifically relating to surface-imprinted films with core-shell structures, their preparation methods, and their application in the separation of damascone and damasne ketone compounds. Background Technology

[0002] Rose-scented fragrances, with their elegant, rich, and layered aroma, play an irreplaceable role in perfumes, cosmetics, food, and daily chemical products. Damascene compounds, in particular, with their extremely low aroma threshold and characteristic rose and fruity sweetness, have become an important base material in high-end fragrances. Currently, these high-value fragrances are mainly prepared through natural extraction, chemical synthesis, or microbial fermentation. However, significant bottlenecks remain in the separation process during large-scale green production. Efficiently separating high-purity aroma components from plant raw materials or fermentation broths is extremely difficult due to the low content of target substances, poor thermal stability, and their tendency to form azeotropic systems with water. Traditional distillation methods are energy-intensive and may damage heat-sensitive components; solvent extraction faces problems of solvent residue and high energy consumption for recovery, making it difficult to balance environmental friendliness and economic efficiency. In contrast, membrane separation technology, with its gentle process, lack of the need for additional reagents, and low energy consumption, shows outstanding potential in addressing these challenges and is a promising green separation method.

[0003] Membranes for separating small organic molecules such as damascene and damasne ketones can be classified by material into polymer membranes, inorganic membranes, and mixed matrix membranes. The separation mechanism relies on the differences in dissolution and diffusion rates of different components within the membrane. Common polymer membranes include polydimethylsiloxane (PDMS), polyvinyl alcohol (PVA), polyetheramide (PEBA), and chitosan (CS). Pan et al. (Angewandte Chemie-International Edition 61 (2022) e202111810) successfully controlled the migration rate of polymer side groups by introducing phenyl groups as rigid molecules into the PDMS molecular chain, and successfully prepared a high-performance PDMS pervaporation membrane. This method reduces the mass transfer resistance of aromatic compounds within the membrane by reconstructing the polymer conformation. While maintaining a high separation factor of 12.3, they achieved a separation efficiency of 11.8 kg m³ / s during the pervaporation removal of phenol. 2 h -1High permeation flux; polymer membranes offer advantages such as strong designability, ease of processing, and low cost. However, it is well known that these materials often suffer from excessive swelling and insufficient mechanical properties in practical applications, leading to poor long-term operational stability and trade-off effects in flux and selectivity, thus limiting their wider application. Inorganic membranes, due to their large surface area, high pore volume, tunable structure, and strong resistance to corrosive operating conditions such as high temperature and high pressure, are promising candidates for adsorption and separation. Wang et al. (Journal of Membrane Science 698 (2024) 122615) prepared an ultrathin ZIF-67 membrane on a porous polymer substrate using a hydroxyl salt-induced in-situ growth method. Subsequently, they modified the ZIF-67 membrane through a vulcanization strategy to expand the pore size and form a hollow structure. A PDMS layer was then spin-coated to eliminate grain boundary defects and enhance hydrophobicity. The prepared hydrophobic ultrathin ZIF-67 / PDMS composite membrane exhibited an extremely high permeation flux (11.6 kg m³) when used for alcohol-preferential pervaporation separation in a 5 wt% ethanol aqueous solution. -2 h -1 Inorganic membranes exhibit excellent separation selectivity while maintaining high separation performance in pervaporation separation. However, problems such as reliable synthesis, manufacturing, or functionalization remain unsolved, requiring a novel process to manufacture continuous and defect-free hydrophobic inorganic membranes. Hybrid matrix membranes (MMMs) composed of polymeric matrices and inorganic fillers combine the advantages of both polymeric and inorganic membranes. They not only break the trade-off limitations of traditional polymeric membranes but also enhance the mechanical strength and thermal stability of membrane materials. Jin et al. (Journal of Membrane Science 716(2025) 123520) first used microporous MAF-6 as a novel filler and incorporated it into a PDMS matrix through a blending method to prepare MAF-6 / PDMS hybrid matrix membranes. When separating dimethyl carbonate / methanol azeotropic mixtures (30 / 70wt%) under optimal process conditions, they exhibited high DMC permeability (651-811 Barrer) and high selectivity (10.1-10.4) during 31 days of continuous operation, surpassing the performance of the most advanced membranes at the time.

[0004] Molecular Imprinting Technology (MIT) involves pre-assembling template molecules and functional monomers through interactions, followed by monomer polymerization to form a rigid network that immobilizes the template molecules. The template is then removed by elution, leaving three-dimensional imprinted cavities in the polymer that are precisely complementary to the template in shape, size, and chemical functional group arrangement. These imprinted cavities can efficiently and selectively recombine target molecules from complex systems based on their shape, size, and chemical functional group arrangement. Yan et al. (Separation and Purification Technology 342 (2024) 126784) used ribavirin as a template and introduced it in situ into UiO-66 with hydroxyl and amino functionalization to prepare ribavirin-imprinted MOF materials. These materials were then used to fabricate ribavirin-imprinted MOF membranes (RIMMs) for separating ribavirin from complex aquatic environments. The membrane exhibited a high adsorption capacity for ribavirin (46.46 mg g / L). -1 ) and selectivity (above 6).

[0005] Damasone and damasne ketone molecules suffer from poor thermal stability, a limited number of active functional groups, and significant temperature-dependent solubility. Current technologies lack imprinted membranes with specific recognition capabilities for damasone and damasne compounds, and are unable to achieve pervaporation separation of these compounds. Summary of the Invention

[0006] This invention discloses an imprinted membrane with specific recognition ability for damascone and damascone-like compounds, which has good pervaporation separation effect for damascone and damasne ketone compounds.

[0007] This invention also discloses a method for preparing a surface-imprinted membrane with a core-shell structure. First, a surface-imprinted material MIL@MITpBD with a core-shell structure and specific recognition capabilities is prepared. Then, it is integrated into a polymer matrix to prepare a surface-imprinted membrane. This surface-imprinted membrane can be applied to the separation of damascone and damasne ketone compounds.

[0008] Damasone and damasne ketone compounds have fewer active groups (taking β-damasone as an example, see attached). Figure 1As shown, since only carbonyl groups are available as active sites, using damascone and damasne ketone compounds as template molecules to prepare imprinted materials results in fewer imprinting sites, lower imprinting efficiency, and difficulty in forming stable and precise imprinted cavities in polymers. This invention uses virtual template molecules instead of damascone compounds. The template molecule has multiple functional groups distributed at different positions that can form hydrogen bonds with the monomer dihydroxybenzidine. This not only improves the imprinting efficiency of the material but also makes the imprinted cavity distribution more uniform, effectively enhancing the specific recognition and selectivity of the imprinted material for damascone compounds. MIL@MITpBD is a core-shell structured surface-imprinted material with uniformly distributed imprinted cavities on the shell surface. These cavities contain hydroxyl and amino interaction sites, enabling precise recognition and preferential adsorption of damascone compounds through shape, size, and hydrogen bonding interactions. Its abundant pore structure provides a rapid diffusion pathway for the transport of damascone molecules. The shell of MIL@MITpBD is composed of an organic covalent framework, exhibiting excellent compatibility with polymers. Molecularly imprinted membranes prepared from this material improve the accessibility and utilization of the imprinted cavities, demonstrating superior damascone compound separation capabilities.

[0009] The technical solution of the present invention is as follows:

[0010] The first aspect of the present invention discloses a method for preparing a surface imprinted film with a core-shell structure, comprising the following steps: (1) preparing a surface imprinted material with a core-shell structure; (2) preparing a surface imprinted film with a core-shell structure.

[0011] Preferably, the preparation of a surface imprinted material with a core-shell structure includes the following steps: (11) using MIL-101-NH2(Cr) as the core structure, the covalent organic framework TpBD-OH is grown in situ on the surface of MIL-101-NH2(Cr) to form a shell, thus forming the MIL@MITpBD core-shell structure; during the growth of the shell, virtual template molecules are introduced into the TpBD-OH shell simultaneously; (12) the template molecules are removed to obtain the surface imprinted material MIL@MITpBD with a core-shell structure that has specific recognition imprinted cavities. The preparation process of the core-shell structured surface imprinted material MIL@MITpBD of this invention is as follows: A metal-organic framework MIL-101-NH2(Cr) is prepared via a hydrothermal method through the coordination interaction between chromium ions and 2-aminoterephthalic acid. MIL-101-NH2(Cr) is also commercially available. Using MIL-101-NH2(Cr) as the core structure, a covalent organic framework TpBD-OH is grown on the outer layer of MIL-101-NH2(Cr) through a ketene-enamine reaction between 3,3'-dihydroxybenzidine and trialdehyde phloroglucinol, forming the MIL@MITpBD core-shell structure. During the growth of the shell, a virtual template molecule that assembles with hydroxyl groups through hydrogen bonding is simultaneously introduced. This virtual template molecule self-assembles with the hydroxyl groups of 3,3'-dihydroxybenzidine and is fixed in the TpBD-OH shell. The template molecule is then removed to obtain the core-shell structured surface imprinted material MIL@MITpBD with a specific recognition cavity.

[0012] The preparation of a surface-imprinted membrane with a core-shell structure includes the following steps: (21) integrating MIL@MITpBD into a polymer matrix to obtain a casting solution; (22) coating the casting solution onto the surface of a support to obtain a surface-imprinted membrane with a core-shell structure.

[0013] Preferably, the detailed steps for preparing surface imprinted materials with a core-shell structure are as follows: (11) Dissolve 3,3'-dihydroxybenzidine in a mixed solvent of solvent A and solvent B with a volume ratio of (0.5~2):1, and ultrasonically disperse it for 0.2~12 h at a temperature of 25~70℃, a frequency of 10~50 kHz, and a power of 200~800W. Then stir it for 0.5~12 h at a temperature of 20~100℃ and a rotation speed of 100~800r / min to obtain solution C; wherein the molar concentration of 3,3'-dihydroxybenzidine in solution C is 0.01~1.0mol / L; add virtual template molecule D to solution C, and stir it for 0.5~12 h at a temperature of 20~100℃ and a rotation speed of 100~800r / min. Solution E was obtained, in which the molar ratio of virtual template molecule D to 3,3'-dihydroxybenzidine was (0.1~3):1. MIL-101-NH2(Cr) was added to solution E and ultrasonically dispersed for 0.2~12 h at a temperature of 25~70°C, a frequency of 10~50 kHz, and a power of 200~800 W. Then, the mixture was stirred for 0.5~12 h at a temperature of 20~100°C and a rotation speed of 100~800 r / min to obtain dispersion F, in which the concentration of MIL-101-NH2(Cr) was 3~40 mg / mL. Trialdehyde phloroglucinol was added to dispersion F and ultrasonically dispersed for 0.2~12 h at a temperature of 25~70°C, a frequency of 10~50 kHz, and a power of 200~800 W to obtain dispersion G, in which the molar concentration of trialdehyde phloroglucinol was 0.01~0.6. mol / L; Add an aqueous acetic acid solution with a concentration of 1~10mol / L to the dispersion G to obtain dispersion H; wherein the volume ratio of the aqueous acetic acid solution to the dispersion G is (0.1~1):1; Freeze-dry the dispersion H three times; After reacting at a temperature of 60~180℃ for 12~96h, cool to room temperature, wash with N,N-dimethylformamide and ethanol 3~5 times, and centrifuge at a speed of 6000~12000 r / min for 1~30 min; Dry in a vacuum oven at a temperature of 50~120℃ for 8~48 h to obtain product I; (12) Elute product I with a mixed solution of acetic acid and methanol with a volume ratio of 1:(5~10) for 0.5~24 h, and dry in a vacuum oven at a temperature of 50~120℃ for 8~48 h to obtain the surface imprinted material MIL@MITpBD with a core-shell structure.

[0014] Preferably, solvent A is trimethylbenzene, solvent B is one of 1,4-dioxane, n-butanol or dimethyl sulfoxide; and virtual template molecule D is one of trans-3-(4-chlorobenzoyl)acrylic acid, trans-4-phenyl-4-oxo-2-butenoic acid or 4-hydroxybenzoylacrylic acid.

[0015] Preferably, the detailed steps for preparing a surface-imprinted film with a core-shell structure are as follows: (21) Add polymer matrix J to solvent K, and stir for 0.5 to 12 h at a temperature of 20 to 100 °C and a rotation speed of 100 to 800 r / min to obtain dispersion L. The mass ratio of polymer matrix J to solvent K is (0.1 to 0.8): 1. Add MIL@MITpBD to dispersion L at a mass ratio of (0.01 to 0.1): 1 with polymer matrix J, and stir for 0.5 to 12 h at a temperature of 20 to 100 °C and a rotation speed of 100 to 800 r / min to obtain dispersion. Liquid M; crosslinking agent N and catalyst O are added to dispersion M in sequence, and stirred for 0.5-12h at a temperature of 20-100℃ and a speed of 100-800r / min to obtain casting liquid P; wherein the mass ratio of crosslinking agent N to polymer matrix J is (0.1-0.5):1, and the mass ratio of catalyst O to crosslinking agent N is (0.01-0.3):1; (22) the casting liquid P is coated on the surface of porous support Q by coating method, and the wet film thickness is controlled to be 20-500μm; thermal crosslinking is performed at 60-240℃ for 12-48h to obtain the surface imprinted film with core-shell structure.

[0016] Preferably, the polymer matrix J is one of polydimethylsiloxane or polyether block amide; the solvent K is one of n-hexane, petroleum ether, isooctane and cyclohexane; the crosslinking agent N is one of tetraethyl orthosilicate, benzyltriethoxysilane or 2-phenylethyltriethoxysilane; the catalyst O is one of dibutyltin dilaurate, dibutyltin maleate or tetrabutyl titanate; and the support Q is one of polysulfone, polyethersulfone, polyvinylidene fluoride or polytetrafluoroethylene, with a molecular weight cutoff of 5000-50000.

[0017] The second aspect of this invention discloses a surface-imprinted film with a core-shell structure prepared by the aforementioned preparation method.

[0018] The third aspect of this invention discloses the application of the surface-imprinted membrane with the core-shell structure for the separation of damascone or damasne ketone compounds.

[0019] Preferably, damascone includes α-damascone, β-damascone and γ-damascone, and damastenone includes α-damastenone, β-damastenone, γ-damastenone and δ-damastenone.

[0020] Preferably, a membrane separation device is used, and the effective area of ​​the membrane is 3~150 cm². 2 The feed flow rate is 10~500L / h, and the feed temperature is 10~60℃. The pressure on the permeation side is controlled by a vacuum pump, the absolute vacuum degree on the permeation side is 0~500Pa, and the permeation time is 1~24h. The separated product is then tested.

[0021] The beneficial effects of this invention are:

[0022] The core-shell structured surface-imprinted material MIL@MITpBD of this invention has numerous specifically imprinted cavities on its surface, with amino and hydroxyl sites distributed within these cavities. These cavities enable precise recognition and preferential adsorption of damascone compounds through shape, size, and hydrogen bonding interactions. Therefore, the core-shell structured surface-imprinted membrane of this invention possesses uniform imprinted cavities, allowing for precise recognition and preferential adsorption of damascone compounds based on shape, size, and hydrogen bonding. The abundant pores of the core-shell structured surface-imprinted material MIL@MITpBD provide a rapid diffusion path for the transport of damascone compound molecules, facilitating molecular diffusion. Furthermore, the covalent organic framework shell of MIL@MITpBD exhibits good compatibility with polymers, improving the accessibility and utilization of imprinted cavities in the molecularly imprinted membrane, significantly enhancing the membrane's separation performance and demonstrating excellent separation performance for damascone compounds. The preparation method of this invention uses virtual template molecules instead of damascone molecules to prepare the imprinted membrane, solving the problems of limited imprinted sites, low imprinting efficiency, and imprecise cavities caused by the single active site of damascone molecules. The virtual template molecule of the present invention is selected from one of trans-3-(4-chlorobenzoyl)acrylic acid, trans-4-phenyl-4-oxo-2-butenoic acid, or 4-hydroxybenzoylacrylic acid. Attached Figure Description

[0023] Figure 1 The images show the molecular structures of β-damascone (top left), the virtual template molecule trans-3-(4-chlorobenzoyl)acrylic acid (bottom left), and 3,3'-dihydroxybenzidine, the raw material for preparing the shell material (right). The virtual template molecule trans-3-(4-chlorobenzoyl)acrylic acid contains –COOH and –Cl, which can undergo hydrogen bonding with the hydroxyl groups of 3,3'-dihydroxybenzidine, the raw material for preparing the shell material. Detailed Implementation

[0024] The present invention will be further illustrated by the following embodiments, but is not limited to the following embodiments.

[0025] First, three comparative examples are given, showing the preparation of PDMS membrane, PDMS / MIL-101-NH2(Cr) membrane, and PEBA / TpBD-OH membrane using existing technologies. PDMS is polydimethylsiloxane, and PEBA is polyether block amide.

[0026] Comparative Example 1:

[0027] First, polydimethylsiloxane (PDMS) was added to n-hexane and magnetically stirred for 5 h at 20 °C and 200 r / min to obtain a dispersion, wherein the mass ratio of PDMS to n-hexane was 0.2:1. Ethyl orthosilicate and dibutyltin dilaurate were added sequentially to the dispersion, and magnetically stirred for 2 h at 40 °C and 300 r / min to obtain a casting solution. The casting solution was coated onto the surface of a porous polysulfone support with a molecular weight cutoff of 5000 using a coating method, controlling the wet film thickness to be 50 μm, wherein the mass ratio of ethyl orthosilicate to PDMS was 0.1:1, and the mass ratio of dibutyltin dilaurate to ethyl orthosilicate was 0.05:1. Finally, the PDMS film was obtained by thermal crosslinking at 80 °C for 12 h.

[0028] The prepared PDMS membrane was subjected to pervaporation performance tests on β-damascone aqueous solution at a temperature of 30℃ and a feed concentration of 100 ppm. The permeation flux was 242 g·m³. -2 ·h -1 The separation factor is 55.

[0029] Comparative Example 2:

[0030] (1) Preparation of MIL-101-NH2(Cr):

[0031] First, chromium nitrate nonahydrate was dissolved in deionized water and ultrasonically dispersed for 1 hour at 30°C, 50kHz, and 600W using an ultrasonic disperser to obtain a Cr-rich solution. 2+ Solution A, in which Cr 2+ The molar concentration was 0.1 mol / L; then, 2-aminoterephthalic acid was added to the above solution A, and ultrasonically dispersed for 1 h at 30°C, 50 kHz, and 600 W using an ultrasonic disperser. The dispersion was then magnetically stirred for 1 h at 30°C and 200 r / min to obtain dispersion B, in which Cr... 2+ The molar ratio of 2-aminoterephthalic acid to 2-aminoterephthalic acid was 1:1. Finally, dispersion B was transferred to a high-pressure reactor and heated at 150°C for 8 h. After the reaction, it was washed three times with N,N'-dimethylformamide and anhydrous ethanol and dried under vacuum at 80°C for 12 h to obtain MIL-101-NH2(Cr).

[0032] (2) Preparation of PDMS / MIL-101-NH2(Cr) membrane:

[0033] First, polydimethylsiloxane (PDMS) was added to cyclohexane and magnetically stirred for 1 h at 30°C and 100 r / min to obtain dispersion C, wherein the mass ratio of PDMS to cyclohexane was 0.4:1. MIL-101-NH2(Cr) was added to dispersion C at a mass ratio of 0.05:1 to PDMS, and magnetically stirred for 3 h at 30°C and 400 r / min to obtain dispersion D. 2-Phenylethyltriethoxysilane and dibutyltin dilaurate were added sequentially to dispersion D, and magnetically stirred for 3 h at 50°C and 400 r / min to obtain casting solution E. Casting solution E was coated onto the surface of a porous polyvinylidene fluoride support with a flux cutoff of 5000 using a coating method, and the wet film thickness was controlled to be 50 μm. The mass ratio of 2-phenylethyltriethoxysilane to polydimethylsiloxane was 0.2:1, and the mass ratio of dibutyltin dilaurate to 2-phenylethyltriethoxysilane was 0.06:1. Finally, the film was thermally crosslinked at 100 °C for 24 h to obtain a PDMS / MIL-101-NH2(Cr) membrane.

[0034] The prepared PDMS / MIL-101-NH2(Cr) membrane was subjected to pervaporation performance tests on β-damascone aqueous solution at a temperature of 30℃ and a feed concentration of 100ppm. The permeation flux was 411 g·m³. -2 ·h -1 The separation factor is 195.

[0035] Comparative Example 3:

[0036] (1) Preparation of TpBD-OH:

[0037] First, 3,3'-dihydroxybenzidine was dissolved in a mixed solvent of trimethylbenzene and 1,4-dioxane. The solution was ultrasonically dispersed for 0.5 h at 25°C, 10 kHz, and 400 W using an ultrasonic cleaner. Then, it was magnetically stirred for 1 h at 20°C and 200 r / min to obtain solution A. Solution A contained in solution A had a molar concentration of 0.09 mol / L for 3,3'-dihydroxybenzidine and a volume ratio (v / v) of 1:1 for trimethylbenzene and 1,4-dioxane. Next, trialdehyde phloroglucinol was added to solution A and ultrasonically dispersed for 1 h at 25°C, 10 kHz, and 400 W using an ultrasonic cleaner to obtain solution B. Solution B contained in solution B had a molar concentration of 0.06 mol / L for trialdehyde phloroglucinol. Next, a 6 mol / L aqueous acetic acid solution was added to solution B to obtain dispersion C, wherein the volume ratio of the aqueous acetic acid solution to solution B was 0.1:1. Dispersion C was then transferred to a Schlenk tube and freeze-dried three times. Following this, the mixture was heated at 120°C for 72 h, cooled to room temperature, and washed three times with N,N-dimethylformamide and ethanol. The washing product was centrifuged at 8000 r / min for 5 min and then dried in a vacuum oven at 80°C for 12 h to obtain the product TpBD-OH.

[0038] (2) Preparation of PEBA / TpBD-OH membrane:

[0039] First, polyether block amide (PEBA) was added to n-hexane and magnetically stirred for 2 hours at 40°C and 200 rpm to obtain dispersion D, wherein the mass ratio of polyether block amide to n-hexane was 0.6:1. TpBD-OH was added to dispersion D at a mass ratio of 0.05:1 to polyether block amide, and magnetically stirred for 2 hours at 40°C and 300 rpm to obtain dispersion E. Benzyltriethoxysilane and dibutyltin maleate were added sequentially to dispersion E, and magnetically stirred for 2 hours at 60°C and 300 rpm to obtain casting solution F. Casting solution F was coated onto the surface of a porous polyethersulfone support with a flux cutoff of 10000 using a coating method, and the wet film thickness was controlled to be 50 μm. The mass ratio of benzyltriethoxysilane to polyether block amide was 0.5:1, and the mass ratio of dibutyltin maleate to benzyltriethoxysilane was 0.1:1. Finally, the film was thermally crosslinked at 150 °C for 12 h to obtain a PEBA / TpBD-OH membrane.

[0040] The prepared PEBA / TpBD-OH membrane was subjected to pervaporation performance tests on β-damascone aqueous solution at 30℃ and a feed concentration of 100 ppm. The permeation flux was 471.58.11 g·m³. -2 ·h-1 The separation factor is 185.21.

[0041] The following is a surface-imprinted membrane of damasone compounds with a core-shell structure prepared by the method of this invention. Compared with the comparative example above, the separation of damasone and damasne ketone aqueous solutions by pervaporation improves the permeation flux and separation factor through the specific recognition and adsorption of imprinted sites.

[0042] Example 1:

[0043] (1) Preparation of surface-imprinted material MIL@MITpBD with core-shell structure:

[0044] First, 3,3'-dihydroxybenzidine was dissolved in a mixed solvent of trimethylbenzene and 1,4-dioxane. The solution was ultrasonically dispersed for 0.5 h at 40°C, 30 kHz, and 400 W using an ultrasonic cleaner. Then, it was magnetically stirred for 1 h at 30°C and 300 r / min to obtain solution C. Solution C contained 0.09 mol / L of 3,3'-dihydroxybenzidine and had a volume ratio (v / v) of 0.5:1 for trimethylbenzene and 1,4-dioxane. Next, trans-3-(4-chlorobenzoyl)acrylic acid was added to solution C and magnetically stirred for 2 h at 50°C and 300 r / min. Solution E was obtained by hydrogen bond self-assembly, with a molar ratio of trans-3-(4-chlorobenzoyl)acrylic acid to 3,3'-dihydroxybenzidine of 0.3:1. Subsequently, MIL-101-NH2(Cr) was added to solution E and ultrasonically dispersed for 0.5 h at 40°C, 30 kHz, and 400 W using an ultrasonic cleaner. Then, the dispersion was magnetically stirred for 3 h at 30°C and 300 r / min to obtain dispersion F, with a MIL-101-NH2(Cr) concentration of 5 mg / mL. Next, trialdehyde phloroglucinol was added to dispersion F and ultrasonically dispersed for 0.5 h at 40°C, 30 kHz, and 400 W using an ultrasonic cleaner to obtain dispersion G, with a trialdehyde phloroglucinol molar concentration of 0.06 mg / mL. Next, a 3 mol / L aqueous solution of acetic acid was added to dispersion G to obtain dispersion H, wherein the volume ratio of the aqueous acetic acid solution to dispersion G was 0.1:1. Dispersion H was then transferred to a Schlenk tube and freeze-dried three times. Next, the mixture was heated at 100°C for 24 h and then cooled to room temperature. It was washed three times with N,N-dimethylformamide and ethanol. The washing product was centrifuged at 10000 r / min for 5 min and dried in a vacuum oven at 80°C for 12 h to obtain product I. Finally, product I was eluted with an acetic acid / methanol solution at a volume ratio of 1:9 for 2 h. It was then dried in a vacuum oven at 80°C for 12 h to obtain the core-shell structured surface-imprinted material MIL@MITpBD.

[0045] (2) Preparation of surface-imprinted films of damascene ketones:

[0046] First, polydimethylsiloxane was added to n-hexane and magnetically stirred for 2 hours at 30°C and 400 rpm to obtain dispersion L. The mass ratio of polydimethylsiloxane to n-hexane was 0.3:1. MIL@MITpBD was then added to dispersion L at a mass ratio of 0.05:1 to polydimethylsiloxane, and magnetically stirred for 4 hours at 30°C and 400 rpm to obtain dispersion M. Tetraethyl orthosilicate and dibutyltin dilaurate were added sequentially to dispersion M. After magnetic stirring at 30℃ and 400 r / min for 2 h, a casting solution P was obtained. Casting solution P was then coated onto the surface of a porous polysulfone support with a molecular weight cutoff of 10000 using a coating method, controlling the wet film thickness to be 50 μm. The mass ratio of tetraethyl orthosilicate to polydimethylsiloxane was 0.1:1, and the mass ratio of dibutyltin dilaurate to tetraethyl orthosilicate was 0.08:1. Finally, a damascone compound surface-imprinted film was obtained by thermal crosslinking at 100℃ for 12 h.

[0047] The prepared damascone-based surface-imprinted film was subjected to pervaporation performance tests on an aqueous solution of β-damascone at 30°C and a raw material concentration of 100 ppm. The pervaporation flux was 587 g·m³. -2 ·h -1 The separation factor is 353.

[0048] Example 2:

[0049] (1) Preparation of surface-imprinted material MIL@MITpBD with core-shell structure:

[0050] First, 3,3'-dihydroxybenzidine was dissolved in a mixed solvent of trimethylbenzene and n-butanol. The solution was ultrasonically dispersed for 0.5 hours at 30°C, 40kHz, and 600W using an ultrasonic cleaner. Then, it was magnetically stirred for 1 hour at 30°C and 300 rpm to obtain solution C. Solution C contained 0.15 mol / L of 3,3'-dihydroxybenzidine, and the volume ratio (v / v) of trimethylbenzene to n-butanol was 1:1. Next, trans-3-(4-chlorobenzoyl)acrylic acid was added to solution C, and the solution was magnetically stirred for 2 hours at 50°C and 300 rpm. Solution E was obtained by hydrogen bond self-assembly, in which the molar ratio of trans-3-(4-chlorobenzoyl)acrylic acid to 3,3'-dihydroxybenzidine was 0.3:1. Subsequently, MIL-101-NH2(Cr) was added to solution E, and the mixture was ultrasonically dispersed for 1 h at 30°C, 40 kHz, and 600 W using an ultrasonic cleaner. Then, it was magnetically stirred for 2 h at 30°C and 300 r / min. Dispersion F was obtained, with a concentration of 5 mg / mL of MIL-101-NH2(Cr). Next, trialdehyde phloroglucinol was added to dispersion F and ultrasonically dispersed for 0.5 h at 40°C, 30 kHz, and 600 W to obtain dispersion G, with a molar concentration of 0.1 mol / L of trialdehyde phloroglucinol. Then, a 5 mol / L aqueous acetic acid solution was added to dispersion G to obtain dispersion H, with a volume ratio of acetic acid solution to dispersion G of 0.1:1. Dispersion H was then transferred to a Schlenk tube and freeze-dried three times. Next, the mixture was heated at 120°C for 72 h, cooled to room temperature, washed five times with N,N-dimethylformamide and ethanol, and the washing product was centrifuged at 10000 r / min for 5 min and dried in a vacuum oven at 100°C for 12 h to obtain product I. Finally, product I was eluted with an acetic acid / methanol solution with a volume ratio of acetic acid to methanol of 1:7 for 1.5 h. The product was then dried in a vacuum oven at 100 °C for 12 h to obtain the surface-imprinted material MIL@MITpBD with a core-shell structure.

[0051] (2) Preparation of surface-imprinted films of damascene ketones:

[0052] First, polydimethylsiloxane was added to cyclohexane and magnetically stirred for 2 hours at 35°C and 300 rpm to obtain dispersion L. The mass ratio of polydimethylsiloxane to cyclohexane was 0.5:1. MIL@MITpBD was then added to dispersion L at a mass ratio of 0.05:1 to polydimethylsiloxane, and magnetically stirred for 3 hours at 35°C and 300 rpm to obtain dispersion M. Tetraethyl orthosilicate and dibutyltin dilaurate were added sequentially to dispersion M. After magnetic stirring at 35℃ and 300 r / min for 4 h, a casting solution P was obtained. Casting solution P was then coated onto the surface of a porous polysulfone support with a molecular weight cutoff of 15000 using a coating method, controlling the wet film thickness to be 50 μm. The mass ratio of tetraethyl orthosilicate to polydimethylsiloxane was 0.3:1, and the mass ratio of dibutyltin dilaurate to tetraethyl orthosilicate was 0.1:1. Finally, a damascone compound surface-imprinted film was obtained by thermal crosslinking at 150℃ for 24 h.

[0053] The prepared damascone-based surface-imprinted film was subjected to pervaporation performance tests on an aqueous solution of β-damascone at 30°C and a raw material concentration of 100 ppm. The pervaporation flux was 612 g·m³. -2 ·h -1 The separation factor is 389.

[0054] Example 3:

[0055] (1) Preparation of surface-imprinted material MIL@MITpBD with core-shell structure:

[0056] First, 3,3'-dihydroxybenzidine was dissolved in a mixed solvent of trimethylbenzene and dimethyl sulfoxide. The solution was ultrasonically dispersed for 2 hours at 60°C, 20kHz, and 500W using an ultrasonic cleaner. Then, it was magnetically stirred for 1 hour at 50°C and 400 rpm to obtain solution C. Solution C contained 0.09 mol / L of 3,3'-dihydroxybenzidine, and the volume ratio (v / v) of trimethylbenzene to dimethyl sulfoxide was 1:1. Next, 4-hydroxybenzoylacrylic acid was added to solution C, and the mixture was magnetically stirred for 3 hours at 50°C and 400 rpm. Solution E was obtained by hydrogen bond self-assembly, in which the molar ratio of 4-hydroxybenzoylacrylic acid to 3,3'-dihydroxybenzidine was 0.3:1. Subsequently, MIL-101-NH2(Cr) was added to solution E, and the mixture was ultrasonically dispersed for 1.5 hours at 60°C, 20kHz, and 500W using an ultrasonic cleaner. Then, it was magnetically stirred for 3 hours at 50°C and 300 rpm. Dispersion F was obtained, with a concentration of 5 mg / mL of MIL-101-NH2(Cr). Next, trialdehyde phloroglucinol was added to dispersion F and ultrasonically dispersed for 2.5 h at 60°C, 20 kHz, and 500 W to obtain dispersion G, with a molar concentration of 0.06 mol / L of trialdehyde phloroglucinol. Then, a 6 mol / L aqueous acetic acid solution was added to dispersion G to obtain dispersion H, with a volume ratio of acetic acid solution to dispersion G of 0.3:1. Dispersion H was then transferred to a Schlenk tube and freeze-dried three times. Next, the mixture was heated at 150°C for 72 h, cooled to room temperature, and washed three times with N,N-dimethylformamide and ethanol. The washing product was centrifuged at 7000 r / min for 5 min and dried in a vacuum oven at 100°C for 10 h to obtain product I. Finally, product I was eluted with an acetic acid / methanol solution with a volume ratio of acetic acid to methanol of 1:5 for 1 h. The product was then dried in a vacuum oven at 100 °C for 10 h to obtain the surface-imprinted material MIL@MITpBD with a core-shell structure.

[0057] (2) Preparation of surface-imprinted films of damascone compounds:

[0058] First, polydimethylsiloxane was added to n-hexane and magnetically stirred for 3 hours at 20°C and 300 rpm to obtain dispersion L. The mass ratio of polydimethylsiloxane to n-hexane was 0.5:1. MIL@MITpBD was then added to dispersion L at a mass ratio of 0.1:1 to polydimethylsiloxane and magnetically stirred for 3 hours at 20°C and 300 rpm to obtain dispersion M. Tetraethyl orthosilicate and dibutyltin dilaurate were added sequentially to dispersion M. After magnetic stirring at 20℃ and 300 r / min for 2 h, a casting solution P was obtained. Casting solution P was then coated onto the surface of a porous polysulfone support with a molecular weight cutoff of 10000 using a coating method, controlling the wet film thickness to be 50 μm. The mass ratio of tetraethyl orthosilicate to polydimethylsiloxane was 0.2:1, and the mass ratio of dibutyltin dilaurate to tetraethyl orthosilicate was 0.1:1. Finally, a damascone compound surface-imprinted film was obtained by thermal crosslinking at 200℃ for 24 h.

[0059] The prepared damascone-based surface-imprinted film was subjected to pervaporation performance tests on an aqueous solution of β-damascone at 30°C and a raw material concentration of 100 ppm. The pervaporation flux was 724 g·m³. -2 ·h -1 The separation factor is 446.

[0060] Example 4:

[0061] (1) Preparation of surface-imprinted material MIL@MITpBD with core-shell structure:

[0062] First, 3,3'-dihydroxybenzidine was dissolved in a mixed solvent of trimethylbenzene and n-butanol. The solution was ultrasonically dispersed for 0.5 hours at 50°C, 40kHz, and 300W using an ultrasonic cleaner. Then, it was magnetically stirred for 1 hour at 40°C and 300 rpm to obtain solution C. Solution C contained 0.09 mol / L of 3,3'-dihydroxybenzidine, and the volume ratio (v / v) of trimethylbenzene to n-butanol was 1:1. Next, trans-4-phenyl-4-oxo-2-butenoic acid was added to solution C, and the mixture was magnetically stirred for 3 hours at 40°C and 300 rpm. Solution E was obtained by hydrogen bond self-assembly, in which the molar ratio of trans-4-phenyl-4-oxo-2-butenoic acid to 3,3'-dihydroxybenzidine was 0.3:1. Subsequently, MIL-101-NH2(Cr) was added to solution E, and the mixture was ultrasonically dispersed for 1.5 h at 50 °C, 40 kHz, and 300 W using an ultrasonic cleaner. Then, it was magnetically stirred for 4 h at 40 °C and 300 r / min. Dispersion F was obtained, with a concentration of 5 mg / mL of MIL-101-NH2(Cr). Next, trialdehyde phloroglucinol was added to dispersion F and ultrasonically dispersed for 2.5 h at 50°C, 40 kHz, and 300 W to obtain dispersion G, with a molar concentration of 0.06 mol / L of trialdehyde phloroglucinol. Then, a 6 mol / L aqueous acetic acid solution was added to dispersion G to obtain dispersion H, with a volume ratio of acetic acid solution to dispersion G of 0.2:1. Dispersion H was then transferred to a Schlenk tube and freeze-dried three times. Next, the mixture was heated at 180°C for 72 h, cooled to room temperature, washed five times with N,N-dimethylformamide and ethanol, and the washing product was centrifuged at 10000 r / min for 5 min and dried in a vacuum oven at 100°C for 8 h to obtain product I. Finally, product I was eluted with an acetic acid / methanol solution with a volume ratio of acetic acid to methanol of 1:9 for 3 h. The product was then dried in a vacuum oven at 120 °C for 8 h to obtain the surface-imprinted material MIL@MITpBD with a core-shell structure.

[0063] (2) Preparation of surface-imprinted films of damascene ketones:

[0064] First, polydimethylsiloxane was added to cyclohexane and magnetically stirred for 2 hours at 35°C and 300 rpm to obtain dispersion L. The mass ratio of polydimethylsiloxane to cyclohexane was 0.1:1. MIL@MITpBD was then added to dispersion L at a mass ratio of 0.05:1 to polydimethylsiloxane. The mixture was magnetically stirred for 2 hours at 40°C and 300 rpm to obtain dispersion M. Tetraethyl orthosilicate and dibutyltin dilaurate were added sequentially to dispersion M. After magnetic stirring at 40℃ and 300 r / min for 4 h, a casting solution P was obtained. Casting solution P was then coated onto the surface of a porous polysulfone support with a molecular weight cutoff of 20,000 using a coating method, controlling the wet film thickness to be 50 μm. The mass ratio of tetraethyl orthosilicate to polydimethylsiloxane was 0.2:1, and the mass ratio of dibutyltin dilaurate to tetraethyl orthosilicate was 0.1:1. Finally, a damascone compound surface-imprinted film was obtained by thermal crosslinking at 200℃ for 48 h.

[0065] The prepared damascone-based surface-imprinted film was subjected to pervaporation performance tests on an aqueous solution of β-damascone at 50°C and a raw material concentration of 100 ppm. The pervaporation flux was 669 g·m³. -2 ·h -1 The separation factor is 418.

[0066] Example 5:

[0067] (1) Preparation of surface-imprinted material MIL@MITpBD with core-shell structure:

[0068] First, 3,3'-dihydroxybenzidine was dissolved in a mixed solvent of trimethylbenzene and 1,4-dioxane. The solution was ultrasonically dispersed for 1.5 hours at 45°C, 20kHz, and 300W using an ultrasonic cleaner. Then, it was magnetically stirred for 2 hours at 30°C and 400 rpm to obtain solution C. The molar concentration of 3,3'-dihydroxybenzidine in solution C was 0.09 mol / L, and the volume ratio (v / v) of trimethylbenzene to 1,4-dioxane was... The ratio of trans-3-(4-chlorobenzoyl)acrylic acid to 3,3'-dihydroxybenzidine was 1:1. Next, trans-3-(4-chlorobenzoyl)acrylic acid was added to solution C, and the mixture was magnetically stirred for 3 hours at 30°C and 400 r / min to complete hydrogen bond self-assembly, yielding solution E. The molar ratio of trans-3-(4-chlorobenzoyl)acrylic acid to 3,3'-dihydroxybenzidine was 0.3:1. Subsequently, MIL-101-NH2(Cr) was added to solution E, and an ultrasonic cleaner was used at 45°C, 20 kHz, and 300 W. After ultrasonic dispersion for 1.5 h, the mixture was magnetically stirred for 3 h at 30 °C and 400 r / min to obtain dispersion F, in which the concentration of MIL-101-NH2(Cr) was 5 mg / mL. Next, trialdehyde phloroglucinol was added to dispersion F, and the mixture was ultrasonically dispersed for 1.5 h at 50 °C, 20 kHz, and 300 W using an ultrasonic cleaner to obtain dispersion G, in which the molar concentration of trialdehyde phloroglucinol was 0.06 mol / L. Then, the... A 5 mol / L aqueous acetic acid solution was added to dispersion G to obtain dispersion H, where the volume ratio of the aqueous acetic acid solution to dispersion G was 0.1:1. Dispersion H was then transferred to a Schlenk tube and freeze-dried three times. Next, the mixture was heated at 120 °C for 24 h, cooled to room temperature, and washed five times with N,N-dimethylformamide and ethanol. The washing product was centrifuged at 8000 r / min for 5 min and dried in a vacuum oven at 100 °C for 12 h to obtain product I. Finally, product I was eluted with an acetic acid / methanol solution at a volume ratio of 1:9 for 2 h. The product was then dried in a vacuum oven at 100 °C for 12 h to obtain the core-shell structured surface-imprinted material MIL@MITpBD.

[0069] (2) Preparation of surface-imprinted films of damascene ketones:

[0070] First, polydimethylsiloxane was added to isooctane and magnetically stirred for 3 hours at 45°C and 300 rpm to obtain dispersion L. The mass ratio of polydimethylsiloxane to isooctane was 0.3:1. MIL@MITpBD was then added to dispersion L at a mass ratio of 0.05:1 to polydimethylsiloxane, and magnetically stirred for 2 hours at 45°C and 300 rpm to obtain dispersion M. Benzyltriethoxysilane and tetrabutyl titanate were added sequentially to dispersion M. After magnetic stirring at 45℃ and 300 r / min for 2 h, a casting solution P was obtained. Casting solution P was then coated onto the surface of a porous polysulfone support with a molecular weight cutoff of 20,000 using a coating method, controlling the wet film thickness to be 50 μm. The mass ratio of benzyltriethoxysilane to polydimethylsiloxane was 0.1:1, and the mass ratio of tetrabutyl titanate to benzyltriethoxysilane was 0.08:1. Finally, a damascone-based compound surface-imprinted film was obtained by thermal crosslinking at 100℃ for 12 h.

[0071] The prepared damascone-based surface-imprinted film was subjected to pervaporation performance tests on an aqueous solution of β-damascone at 30°C and a raw material concentration of 200 ppm. The pervaporation flux was 620 g·m³. -2 ·h -1 The separation factor is 318.

[0072] Example 6:

[0073] (1) Preparation of surface-imprinted material MIL@MITpBD with core-shell structure:

[0074] First, 3,3'-dihydroxybenzidine was dissolved in a mixed solvent of trimethylbenzene and 1,4-dioxane. The solution was ultrasonically dispersed for 2 hours at 30°C, 40 kHz, and 400 W using an ultrasonic cleaner. Then, it was magnetically stirred for 2 hours at 30°C and 500 r / min to obtain solution C. Solution C contained 0.09 mol / L of 3,3'-dihydroxybenzidine, and the volume ratio (v / v) of trimethylbenzene to 1,4-dioxane was 1:1. Next, trans-3-(4-chlorobenzoyl)acrylic acid was added to solution C, and the mixture was magnetically stirred for 4 hours at 30°C and 500 r / min. Solution E was obtained by hydrogen bond self-assembly, with a molar ratio of trans-3-(4-chlorobenzoyl)acrylic acid to 3,3'-dihydroxybenzidine of 0.3:1. MIL-101-NH2(Cr) was then added to solution E and ultrasonically dispersed for 2 h at 30°C, 40 kHz, and 400 W. The dispersion was then magnetically stirred for 2 h at 30°C and 500 r / min to obtain dispersion F, with a MIL-101-NH2(Cr) concentration of 5 mg / mL. Next, trialdehyde phloroglucinol was added to dispersion F and ultrasonically dispersed for 2.5 h at 30°C, 40 kHz, and 400 W to obtain dispersion G, with a trialdehyde phloroglucinol molar concentration of 0.06 mol / L. Finally, a concentration of 5 mg / mL was added to... A mol / L aqueous solution of acetic acid was added to dispersion G to obtain dispersion H, wherein the volume ratio of aqueous acetic acid to dispersion G was 0.1:1. Dispersion H was then transferred to a Schlenk tube and freeze-dried three times. Next, the mixture was heated at 120 °C for 72 h, cooled to room temperature, and washed three times with N,N-dimethylformamide and ethanol. The washing product was centrifuged at 12000 r / min for 5 min and dried in a vacuum oven at 80 °C for 12 h to obtain product I. Finally, product I was eluted with an acetic acid / methanol solution at a volume ratio of 1:9 for 2 h. The product was then dried in a vacuum oven at 80 °C for 12 h to obtain the core-shell structured surface-imprinted material MIL@MITpBD.

[0075] (2) Preparation of surface-imprinted films of damascene ketones:

[0076] First, polydimethylsiloxane (PDMS) was added to n-hexane and magnetically stirred for 1 hour at 30°C and 400 r / min to obtain dispersion L. The mass ratio of PDMS to n-hexane was 0.2:1. MIL@MITpBD was then added to dispersion L at a mass ratio of 0.05:1 to PDMS and magnetically stirred for 4 hours at 30°C and 400 r / min to obtain dispersion M. Tetraethyl orthosilicate and dibutyltin dilaurate were added sequentially to dispersion M. After magnetic stirring at 30℃ and 400 r / min for 2 h, a casting solution P was obtained. Casting solution P was then coated onto the surface of a porous polysulfone support with a molecular weight cutoff of 30,000 using a coating method, controlling the wet film thickness to be 50 μm. The mass ratio of tetraethyl orthosilicate to polydimethylsiloxane was 0.1:1, and the mass ratio of dibutyltin dilaurate to tetraethyl orthosilicate was 0.08:1. Finally, a damascone compound surface-imprinted film was obtained by thermal crosslinking at 100℃ for 12 h.

[0077] The prepared damasne compound surface-imprinted film was subjected to pervaporation performance tests on an aqueous solution of β-damasne at a test temperature of 30℃ and a raw material concentration of 100ppm. The permeation flux was 645 g·m³. -2 ·h -1 The separation factor is 392.

[0078] Example 7:

[0079] (1) Preparation of surface-imprinted material MIL@MITpBD with core-shell structure:

[0080] First, 3,3'-dihydroxybenzidine was dissolved in a mixed solvent of trimethylbenzene and dimethyl sulfoxide. The solution was ultrasonically dispersed for 0.5 h at 25°C, 10 kHz, and 400 W using an ultrasonic cleaner. Then, it was magnetically stirred for 1 h at 20°C and 200 r / min to obtain solution C. Solution C contained 0.09 mol / L of 3,3'-dihydroxybenzidine and had a volume ratio (v / v) of 0.9:1 for trimethylbenzene and dimethyl sulfoxide. Next, 4-hydroxybenzoylacrylic acid was added to solution C and magnetically stirred for 1 h at 40°C and 400 r / min. Solution E was obtained by hydrogen bond self-assembly, with a molar ratio of 4-hydroxybenzoylacrylic acid to 3,3'-dihydroxybenzidine of 0.3:1. Subsequently, MIL-101-NH2(Cr) was added to solution E and ultrasonically dispersed for 2.5 h at 50°C, 50 kHz, and 600 W using an ultrasonic cleaner. Then, the dispersion was magnetically stirred for 3 h at 40°C and 400 r / min to obtain dispersion F, with a MIL-101-NH2(Cr) concentration of 5 mg / mL. Next, trialdehyde phloroglucinol was added to dispersion F and ultrasonically dispersed for 1.5 h at 50°C, 50 kHz, and 600 W using an ultrasonic cleaner to obtain dispersion G, with a trialdehyde phloroglucinol molar concentration of 0.06 mg / mL. Next, a 6 mol / L aqueous solution of acetic acid was added to dispersion G to obtain dispersion H, wherein the volume ratio of the aqueous acetic acid solution to dispersion G was 0.1:1. Dispersion H was then transferred to a Schlenk tube and freeze-dried three times. Following this, the mixture was heated at 140 °C for 48 h and then cooled to room temperature. It was washed three times with N,N-dimethylformamide and ethanol. The washing product was centrifuged at 10000 r / min for 5 min and dried in a vacuum oven at 80 °C for 12 h to obtain product I. Finally, product I was eluted with an acetic acid / methanol solution at a volume ratio of 1:5 for 1 h. It was then dried in a vacuum oven at 80 °C for 12 h to obtain the core-shell structured surface-imprinted material MIL@MITpBD.

[0081] (2) Preparation of surface-imprinted films of damascene ketones:

[0082] First, polyether block amide (PEBA) was added to n-hexane and magnetically stirred for 2 h at 40 °C and 400 r / min to obtain dispersion L. The mass ratio of polyether block amide to n-hexane was 0.3:1. MIL@MITpBD was then added to dispersion L at a mass ratio of 0.05:1 to polyether block amide, and magnetically stirred for 3 h at 40 °C and 400 r / min to obtain dispersion M. Tetraethyl orthosilicate and dibutyltin dilaurate were added sequentially to dispersion M. After magnetic stirring at 40 °C and 400 r / min for 3 h, a casting solution P was obtained. Casting solution P was then coated onto the surface of a porous polysulfone support with a molecular weight cutoff of 50,000 using a coating method, controlling the wet film thickness to be 50 μm. The mass ratio of tetraethyl orthosilicate to polydimethylsiloxane was 0.1:1, and the mass ratio of dibutyltin dilaurate to tetraethyl orthosilicate was 0.08:1. Finally, a damascone compound surface-imprinted film was obtained by thermal crosslinking at 100 °C for 12 h.

[0083] The prepared damascone-based surface-imprinted film was subjected to pervaporation performance tests on an aqueous solution of β-damascone at a test temperature of 30℃ and a raw material concentration of 100ppm. The permeation flux was 520 g·m³. -2 ·h -1 The separation factor is 347.

[0084] In summary, the permeation flux of the polydimethylsiloxane (PDMS) membrane in Comparative Example 1 was 242 g·m³ under the conditions of a test temperature of 30°C and a raw material concentration of 100 ppm for the β-damascone aqueous solution. -2 ·h -1 The separation factor was 55; the PDMS / MIL-101-NH2(Cr) membrane prepared in Comparative Example 2 had a permeation flux of 411 g·m⁻¹ for the β-damascone aqueous solution under the conditions of a test temperature of 30 °C and a feed concentration of 100 ppm. -2 ·h -1 The separation factor was 195. Compared with Comparative Examples 1 and 2, the separation ability of the damascone surface-imprinted membranes prepared in Examples 1-6 for β-damascone was significantly improved. Example 1 tested the separation performance of the prepared damascone surface-imprinted membrane for β-damascone aqueous solution at a test temperature of 30°C and a raw material concentration of 100 ppm, with a permeation flux of 587 g·m³. -2 ·h -1The separation factor was 353; the introduction of the core-shell structured surface-imprinted material MIL@MITpBD significantly improved the membrane's separation performance. Example 2 tested the separation performance of a damascone surface-imprinted membrane with increased shell thickness for β-damascone aqueous solution at a test temperature of 30°C and a feed concentration of 100 ppm, achieving a permeation flux of 612 g·m³. -2 ·h -1 The separation factor was 389. Increasing the thickness of the imprinted layer increases the number of imprinted cavities and improves the adsorption capacity for β-damascone. Example 3 increased the amount of the core-shell structured surface imprinted material MIL@MITpBD added to the membrane. The damascone-based surface imprinted membrane was tested for separation performance of β-damascone aqueous solution at a test temperature of 30°C and a raw material concentration of 100 ppm. The permeation flux was 724 g·m³. -2 ·h -1 The separation factor was 446. Increasing the amount of MIL@MITpBD added to the membrane introduced more specific recognition sites and diffusion channels, significantly improving flux and separation factor. Example 4 involved increasing the testing temperature. The surface-imprinted membrane of damascone compounds prepared was tested for pervaporation performance of β-damascone aqueous solution at a testing temperature of 50°C and a raw material concentration of 100 ppm. The permeation flux was 669 g·m³. -2 ·h -1 The separation factor was 418; increasing the operating temperature enhanced the driving force on both sides of the membrane, effectively improving the membrane's separation performance. In Example 5, the concentration of the feed solution was increased, and the damascone-based surface-imprinted membrane was tested for separation performance of β-damascone aqueous solution at a test temperature of 30℃ and a feed concentration of 200 ppm. The permeation flux was 620 g·m³. -2 ·h -1 The separation factor was 318. While increasing the feed concentration increases the concentration difference across the membrane and thus the flux, it also decreases the separation factor. Example 6 used a porous polysulfone support with a molecular cutoff of 30,000 to prepare a surface-imprinted membrane for damascenone compounds. The separation performance for β-damascenone aqueous solutions was tested at 30°C and a feed concentration of 100 ppm, with a permeation flux of 645 g·m³. -2 ·h -1 The separation factor was 392. Comparative Example 3 prepared a PEBA / TpBD-OH membrane (PEBA polyether block amide), and the permeation flux of the β-damastenone aqueous solution was 542 g·m⁻¹ under the conditions of a test temperature of 30℃ and a feed concentration of 100 ppm. -2 ·h -1The separation factor was 246; in Example 7, a damascone surface-imprinted membrane prepared using PEBA was tested for separation performance against β-damascone aqueous solution at a test temperature of 30°C and a feed concentration of 100 ppm, with a permeation flux of 520 g·m⁻¹. -2 ·h -1 The separation factor was 347; compared with Comparative Example 3, the separation performance of β-damascenone in Example 7 was also significantly improved. It can be seen that the core-shell structured surface imprinted membrane of the present invention can significantly improve the separation performance of damascenone compounds; the reasons are as follows: (1) Using virtual template molecules instead of damascenone molecules for imprinting increases the number of imprinting sites, increases imprinting efficiency, and standardizes the imprinted cavity structure; (2) The surface of MIL@MITpBD has a large number of specific imprinted cavities, and amino and hydroxyl sites are distributed in the cavities, which can accurately identify and preferentially adsorb damascenone compounds through shape, size and hydrogen bond interaction; (3) MIL@MITpBD has a rich pore structure, which provides a fast diffusion path for the transfer of damascenone compound molecules; (4) The shell of MIL@MITpBD is composed of a covalent organic framework, which has excellent compatibility with polymers. The molecular imprinted membrane prepared from it improves the accessibility and utilization of the imprinted cavity, and greatly improves the separation performance of the membrane.

[0085] Although the present invention has been described above, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many modifications under the guidance of the present invention without departing from the spirit of the present invention, and these modifications are all within the protection scope of the present invention.

Claims

1. A method for preparing a surface-imprinted film with a core-shell structure, characterized in that, The process includes the following steps: (1) preparing a surface imprinted material with a core-shell structure; (2) preparing a surface imprinted film with a core-shell structure.

2. The preparation method according to claim 1, characterized in that, The preparation of surface imprinted materials with core-shell structure includes the following steps: (11) Using MIL-101-NH2(Cr) as the core structure, the covalent organic framework TpBD-OH is grown in situ on the surface of MIL-101-NH2(Cr) to form a shell, thus forming the MIL@MITpBD core-shell structure; during the growth of the shell, virtual template molecules are introduced into the TpBD-OH shell simultaneously; (12) The template molecules are removed to obtain the surface imprinted material MIL@MITpBD with core-shell structure; The preparation of a surface-imprinted membrane with a core-shell structure includes the following steps: (21) integrating MIL@MITpBD into a polymer matrix to obtain a casting solution; (22) coating the casting solution onto the surface of a support to obtain a surface-imprinted membrane with a core-shell structure.

3. The preparation method according to claim 2, characterized in that, The detailed steps for preparing surface-imprinted materials with core-shell structures are as follows: (11) Dissolve 3,3'-dihydroxybenzidine in a mixed solvent of solvent A and solvent B with a volume ratio of (0.5~2):1, and ultrasonically disperse it for 0.2~12 h at a temperature of 25~70℃, a frequency of 10~50 kHz, and a power of 200~800W. Then stir it for 0.5~12 h at a temperature of 20~100℃ and a rotation speed of 100~800 r / min to obtain solution C; wherein the molar concentration of 3,3'-dihydroxybenzidine in solution C is 0.01~1.0 mol / L; add virtual template molecule D to solution C, and stir it for 0.5~12 h at a temperature of 20~100℃ and a rotation speed of 100~800 r / min. Solution E was obtained, in which the molar ratio of virtual template molecule D to 3,3'-dihydroxybenzidine was (0.1~3):

1. MIL-101-NH2(Cr) was added to solution E and ultrasonically dispersed for 0.2~12 h at a temperature of 25~70°C, a frequency of 10~50 kHz, and a power of 200~800 W. Then, the mixture was stirred for 0.5~12 h at a temperature of 20~100°C and a rotation speed of 100~800 r / min to obtain dispersion F, in which the concentration of MIL-101-NH2(Cr) was 3~40 mg / mL. Trialdehyde phloroglucinol was added to dispersion F and ultrasonically dispersed for 0.2~12 h at a temperature of 25~70°C, a frequency of 10~50 kHz, and a power of 200~800 W to obtain dispersion G, in which the molar concentration of trialdehyde phloroglucinol was 0.01~0.

6. mol / L; Add an aqueous acetic acid solution with a concentration of 1~10mol / L to the dispersion G to obtain dispersion H; wherein the volume ratio of the aqueous acetic acid solution to the dispersion G is (0.1~1):1; Freeze-dry the dispersion H three times; After reacting at a temperature of 60~180℃ for 12~96h, cool to room temperature, wash with N,N-dimethylformamide and ethanol 3~5 times, centrifuge at a speed of 6000~12000 r / min for 1~30min; dry in a vacuum oven at a temperature of 50~120℃ for 8~48h to obtain product I; (12) Elute product I with a mixed solution of acetic acid and methanol with a volume ratio of 1:(5~10) for 0.5~24h, and dry in a vacuum oven at a temperature of 50~120℃ for 8~48h to obtain the surface imprinted material MIL@MITpBD with a core-shell structure.

4. The preparation method according to claim 3, characterized in that, Solvent A is trimethylbenzene; solvent B is one of 1,4-dioxane, n-butanol, or dimethyl sulfoxide; virtual template molecule D is one of trans-3-(4-chlorobenzoyl)acrylic acid, trans-4-phenyl-4-oxo-2-butenoic acid, or 4-hydroxybenzoylacrylic acid.

5. The preparation method according to claim 2, characterized in that, The detailed steps for preparing a surface-imprinted film with a core-shell structure are as follows: (21) Add polymer matrix J to solvent K and stir for 0.5-12 h at a temperature of 20-100℃ and a rotation speed of 100-800 r / min to obtain dispersion L. The mass ratio of polymer matrix J to solvent K is (0.1-0.8):

1. Add MIL@MITpBD to dispersion L at a mass ratio of (0.01-0.1):1 with polymer matrix J. Stir for 0.5-12 h at a temperature of 20-100℃ and a rotation speed of 100-800 r / min to obtain dispersion M. Crosslinking agent N and catalyst O are added to dispersion M in sequence, and stirred for 0.5-12h at a temperature of 20-100℃ and a speed of 100-800r / min to obtain casting liquid P; wherein the mass ratio of crosslinking agent N to polymer matrix J is (0.1-0.5):1, and the mass ratio of catalyst O to crosslinking agent N is (0.01-0.3):1; (22) Casting liquid P is coated on the surface of porous support Q by coating method, and the wet film thickness is controlled to be 20-500μm; thermal crosslinking is performed at 60-240℃ for 12-48h to obtain the surface imprinted film with core-shell structure.

6. The preparation method according to claim 5, characterized in that, The polymer matrix J is one of polydimethylsiloxane or polyether block amide; the solvent K is one of n-hexane, petroleum ether, isooctane and cyclohexane; the crosslinking agent N is one of tetraethyl orthosilicate, benzyltriethoxysilane or 2-phenylethyltriethoxysilane; the catalyst O is one of dibutyltin dilaurate, dibutyltin maleate or tetrabutyl titanate; the support Q is one of polysulfone, polyethersulfone, polyvinylidene fluoride or polytetrafluoroethylene, with a molecular weight cutoff of 5000-50000.

7. A surface-imprinted film with a core-shell structure prepared by any of the preparation methods described in claims 1-6.

8. The application of the core-shell structured surface-imprinted membrane according to claim 7 for the separation of damascone or damasne ketone compounds.

9. The application according to claim 8, characterized in that, Damascones include α-damascones, β-damascones, and γ-damascones, while damastenones include α-damastenone, β-damastenone, γ-damastenone, and δ-damastenone.

10. The application according to claim 8, characterized in that, A membrane separation device is used, with a feed liquid temperature of 10~60℃ and an absolute vacuum of 0~500Pa on the permeate side.

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