Method for growing molecular sieve membrane in kettle-free normal-pressure system

Abstract

The present invention relates to the technical field of the preparation of molecular sieve membranes. Provided is a method for growing a molecular sieve membrane in a kettle-free normal-pressure system. The method provided by the present invention can implement the synthesis of a molecular sieve membrane in a kettle-free normal-pressure system, and can grow a molecular sieve membrane of any size and any thickness by utilizing a small amount of a mother liquor; and the molecular sieve membrane can be synthesized at a relatively low temperature, or even at room temperature, and is applicable to a wide variety of substrates. In the present invention, by introducing free radicals into a reaction system, the crystallization of a molecular sieve can be accelerated, thereby promoting the growth of a molecular sieve membrane, and a high-quality molecular sieve membrane is thus rapidly obtained. By means of the present invention, a molecular sieve membrane can be grown on a variety of substrates on which molecular sieve membranes cannot be grown by means of conventional methods and which are not heat-resistant and have poor stability; therefore, the method can effectively expand the application range of molecular sieve membranes, and has important value in the practical application of molecular sieve membranes in many fields such as energy storage, medicine, information and petrochemical industry.

Description

A method for growing molecular sieve membranes in a non-aqueous atmospheric pressure system

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on August 14, 2023, with application number CN202311018142.6 and invention name “A method for growing molecular sieve membranes in a non-aqueous normal pressure system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the technical field of molecular sieve membrane preparation, in particular to a method for growing a molecular sieve membrane in a non-aqueous normal pressure system. Background Art

[0003] Molecular sieve membranes have been commercialized and industrialized in many fields such as adsorption, separation, and catalysis, and have very important application value. At present, the preparation of molecular sieve membranes mainly adopts the hydrothermal synthesis method, which has a high reaction temperature. Most reaction temperatures exceed 100°C. The preparation process needs to be carried out in a limited closed space provided by a high-pressure hydrothermal reactor, which not only limits the size of the molecular sieve membrane, but also leads to extremely high costs for large-scale production. At the same time, due to the high reaction temperature for the preparation of molecular sieve membranes, the optional substrates for growing molecular sieve membranes are also very limited. For example, when using the traditional hydrothermal method to synthesize molecular sieve membranes, high-temperature resistant substrates such as ceramics, metals, and metal oxides are generally selected, and molecular sieve membranes are often not able to be grown on substrates that are not resistant to high temperatures (such as polymers). Therefore, it is very necessary to develop a method for growing molecular sieve membranes under low-temperature and normal pressure conditions without the use of a reactor.

[0004] Summary of the Invention

[0005] In view of this, the present invention aims to provide a method for growing molecular sieve membranes in a non-autoclave, atmospheric pressure system. The present invention achieves atmospheric pressure and low-temperature synthesis of molecular sieve membranes in a non-autoclave, open-circuit system, is applicable to a wide variety of substrates, and can produce molecular sieve membranes of any size and thickness.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for growing a molecular sieve membrane in a non-aqueous atmospheric pressure system, comprising the following steps:

[0008] Prepare a molecular sieve membrane growth mother solution; the molar ratio of alkali metal oxide, Al2O3, SiO2 and H2O in the molecular sieve membrane growth mother solution is (1-100):1:(1-25):(50-2000), and the alkali metal oxide is one or more of Na2O, K2O, Li2O and Cs2O;

[0009] The molecular sieve membrane growth mother solution is placed in an open container, a substrate is immersed in the molecular sieve membrane growth mother solution, and a molecular sieve membrane is grown on the surface of the substrate; the growth temperature is room temperature to 60°C.

[0010] Preferably, the substrate includes an inorganic material substrate, an organic material substrate or a composite material substrate; before being immersed in the molecular sieve membrane growth mother liquid, the substrate is also pretreated; the pretreatment method is to treat the substrate in at least one of the following ways: cutting, cleaning, drying, plasma treatment, calcination, loading crystal seeds, and immersing in a treatment liquid; the treatment liquid includes an acid solution, an alkaline solution, an organic solution or a strong oxidizing solution.

[0011] Preferably, the growth is performed under conditions that introduce free radicals.

[0012] Preferably, the method of introducing free radicals comprises subjecting the molecular sieve membrane growth mother solution soaked with the substrate to at least one of the following treatments: ultraviolet irradiation, sunlight or simulated sunlight irradiation, ultrasound, microwaves, and addition of a free radical initiator.

[0013] Preferably, the ultraviolet wavelength of the ultraviolet radiation is 290-390 nm, and the irradiation intensity is 0.8-20 W / m 2 The irradiation time is 4 to 36 hours.

[0014] Preferably, the intensity of the sunlight or simulated sunlight is 500-1800 W / m 2 , the irradiation time is 8 to 100 hours.

[0015] Preferably, the power of the ultrasound is 40 to 400 W, and the time is 1 minute to 4 hours.

[0016] Preferably, the microwave power is 50 to 1800 W, and the duration is 1 minute to 1 hour.

[0017] Preferably, the free radical initiator includes peroxide and / or high-valent metal ion compound; the concentration of the free radical initiator in the molecular sieve membrane growth mother solution is 1×10 -4 mol / mL~1×10 -3 mol / mL; after adding a free radical initiator to the molecular sieve membrane growth mother solution soaked with a substrate, the growth time of the molecular sieve membrane is 6 to 100 hours.

[0018] Preferably, the topological structure of the molecular sieve membrane includes LTA, FAU, SOD, BIK, CHA, MFI, EMT, MOR or BEA; and the FAU includes FAU-X or FAU-Y.

[0019] The present invention provides a method for growing a molecular sieve membrane in a non-aqueous atmospheric pressure system, comprising the following steps: preparing a molecular sieve membrane growth mother solution; wherein the molar ratio of alkali metal oxide, Al2O3, SiO2, and H2O in the molecular sieve membrane growth mother solution is (1-100):1:(1-25):(50-2000), and the alkali metal oxide is one or more of Na2O, K2O, Li2O, and Cs2O; placing the molecular sieve membrane growth mother solution in an open container, immersing a substrate in the molecular sieve membrane growth mother solution, and growing the molecular sieve membrane on the substrate surface; the growth temperature is room temperature to 60°C. The molecular sieve membrane growth mother solution in the present invention can provide sufficient cations as structure-directing agents, which is conducive to the crystallization of the molecular sieve. Furthermore, by introducing free radicals into the reaction system, the crystallization of the molecular sieve can be accelerated, thereby promoting the growth of the molecular sieve membrane, which is conducive to obtaining a higher quality molecular sieve membrane more quickly. Specifically, the SiO4 and AlO4 fragments in the molecular sieve membrane growth mother liquor form an amorphous thin film on the substrate surface and nucleate and grow into a continuous film. Free radicals can play a promoting role in the above process.

[0020] The present invention realizes the synthesis of molecular sieve membranes in a non-aqueous normal pressure system for the first time, without the need for synthesis under high pressure conditions in a closed environment; it is capable of growing molecular sieve membranes of any size and thickness, and is not limited by the size of the reactor; it can be synthesized at a relatively low temperature (room temperature to 60°C); it is applicable to a wide range of substrates, and molecular sieve membranes can also be synthesized on substrates (such as polymer substrates) on which molecular sieve membranes cannot be prepared by traditional methods; in addition, the preparation method provided by the present invention can be used to prepare ultra-thin molecular sieve membranes. Furthermore, due to the action of free radicals replacing the action of part of the hydroxide and water in the mother liquor of the molecular sieve membrane growth, the amount of mother liquor used can be reduced, and there is no need to use a large amount of mother liquor to synthesize the molecular sieve membrane. The present invention can effectively expand the scope of application of molecular sieve membranes, and is of great value for the practical application of molecular sieve membranes in many fields such as energy storage, medicine, information, and petrochemicals. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is an XRD spectrum and SEM image of the LTA molecular sieve membrane / PP membrane sample prepared in Example 1, (a) is the XRD spectrum of the LTA molecular sieve membrane / PP membrane sample, (b) is the SEM image of the LTA molecular sieve membrane / PP membrane sample, (c) is a cross-sectional SEM image of the LTA molecular sieve membrane / PP membrane sample, (d) is a physical photograph of the LTA molecular sieve membrane / PP membrane sample at the top, and is a physical photograph of the sample prepared using the existing technology (using a reaction temperature of 100°C and a hydrothermal reactor) at the bottom;

[0022] Figure 2 is an XRD spectrum and SEM image of the LTA molecular sieve membrane / stainless steel mesh sample prepared in Example 2, (a) is the XRD spectrum of the LTA molecular sieve membrane / stainless steel mesh sample, (b) is the SEM image of the LTA molecular sieve membrane / stainless steel mesh sample, and (c) is an enlarged SEM image of the LTA molecular sieve membrane / stainless steel mesh sample;

[0023] FIG3 is an XRD spectrum and SEM image of the LTA molecular sieve membrane / glass sample prepared in Example 3, (a) is an XRD pattern of the LTA molecular sieve membrane / glass sample, and (b) is an SEM image of the LTA molecular sieve membrane / glass sample;

[0024] FIG4 is an EPR spectrum of the molecular sieve membrane growth mother solution of Example 4;

[0025] Figure 5 is an SEM image of the molecular sieve membrane of Example 4 irradiated with ultraviolet light for different times, (a) is an SEM image of the molecular sieve membrane irradiated with ultraviolet light for 4 hours, and (b) is an SEM image of the molecular sieve membrane irradiated with ultraviolet light for 6 hours;

[0026] Figure 6 is an XRD spectrum and SEM image of the FAU-Y molecular sieve membrane / titanium sheet sample prepared in Example 5, (a) is the XRD pattern of the FAU-Y molecular sieve membrane / titanium sheet sample, (b) is the SEM image of the FAU-Y molecular sieve membrane / titanium sheet sample, and (c) is a cross-sectional SEM image of the FAU-Y molecular sieve membrane / titanium sheet sample;

[0027] Figure 7 is an XRD spectrum and SEM image of the SOD molecular sieve film / glass sample prepared in Example 6, (a) is the XRD pattern of the SOD molecular sieve film / glass sample, (b) is the SEM image of the SOD molecular sieve film / glass sample, and (c) is a cross-sectional SEM image of the SOD molecular sieve film / glass sample;

[0028] FIG8 is an EPR spectrum of the molecular sieve membrane growth mother solution in Example 7;

[0029] Figure 9 is an SEM image of the zeolite membrane of Example 7 after reaction for different times when no free radicals are introduced, (a) is an SEM image of the zeolite membrane after reaction for 4 hours when no free radicals are introduced, (b) is an SEM image of the zeolite membrane after reaction for 6 hours when no free radicals are introduced, and (c) is an SEM image of the zeolite membrane after reaction for 8 hours when no free radicals are introduced. DETAILED DESCRIPTION

[0030] The present invention provides a method for growing a molecular sieve membrane in a non-aqueous atmospheric pressure system, comprising the following steps:

[0031] Prepare a molecular sieve membrane growth mother solution; the molar ratio of alkali metal oxide, Al2O3, SiO2 and H2O in the molecular sieve membrane growth mother solution is (1-100):1:(1-25):(50-2000), and the alkali metal oxide is one or more of Na2O, K2O, Li2O and Cs2O;

[0032] The molecular sieve membrane growth mother solution is placed in an open container, a substrate is immersed in the molecular sieve membrane growth mother solution, and a molecular sieve membrane is grown on the surface of the substrate; the growth temperature is room temperature to 60°C.

[0033] In the present invention, unless otherwise specified, the raw materials are all commercially available products well known to those skilled in the art.

[0034] The present invention prepares a molecular sieve membrane growth mother solution. In the present invention, the molar ratio of alkali metal oxide, Al2O3, SiO2, and H2O in the molecular sieve membrane growth mother solution is (1-100):1:(1-25):(50-2000), and the alkali metal oxide is Na2O, K2O, Li2O, or Cs2O. The alkali metal oxide, Al2O3, SiO2, and H2O in the molecular sieve membrane growth mother solution are obtained by converting the raw materials used to prepare the molecular sieve membrane growth mother solution accordingly.

[0035] In the present invention, the raw materials for preparing the molecular sieve membrane growth mother solution preferably include a silicon source, an aluminum source and water, or include a silicon source, an aluminum source, an alkali metal hydroxide (ie, NaOH, KOH, LiOH or CsOH) and water. In the present invention, the aluminum source preferably includes one or more of aluminum, aluminum oxide, aluminum hydroxide, sodium aluminate and pseudo-boehmite; the silicon source preferably includes one or more of white carbon black, silica sol, sodium silicate and tetraethyl orthosilicate; when the aluminum source and the silicon source contain the alkali metal element, and after conversion to alkali metal oxide, Al2O3 and SiO2, the molar ratio of the above-mentioned alkali metal oxide, Al2O3, SiO2 and H2O is satisfied, then the raw materials for preparing the molecular sieve membrane growth mother solution include silicon source, aluminum source and water; when the aluminum source and the silicon source do not contain the alkali metal element, or after conversion to alkali metal oxide, Al2O3 and SiO2, the amount of alkali metal oxide is less than the molar ratio requirement of the above-mentioned alkali metal oxide, Al2O3, SiO2 and H2O, then the raw materials for preparing the molecular sieve membrane growth mother solution include silicon source, aluminum source, alkali metal hydroxide and water.

[0036] In the present invention, when growing an LTA type molecular sieve membrane, the molar ratio of Na2O, Al2O3, SiO2 and H2O in the molecular sieve membrane growth mother liquor is preferably (30-45):1:(1-10):(400-600) or (1-10):1:(1-5):(50-300); when growing an FAU-X type molecular sieve membrane, the molar ratio of Na2O, Al2O3, SiO2 and H2O in the molecular sieve membrane growth mother liquor is preferably (50-100):1:(1-20):(300-1000); when growing an FAU-Y type molecular sieve membrane, the molar ratio of Na2O, Al2O3, SiO2 and H2O in the molecular sieve membrane growth mother liquor is preferably (50-100):1:(1-25):(300-2000); when growing an SOD type molecular sieve membrane, the molar ratio of Na2O, Al2O3, SiO2 and H2O in the molecular sieve membrane growth mother liquor is preferably (50-100):1:(1-25):(300-2000); When growing a molecular sieve membrane, the molar ratio of Na2O, Al2O3, SiO2 and H2O in the molecular sieve membrane growth mother solution is preferably (50-100):1:(1-20):(300-1000); when growing a BIK type molecular sieve membrane, the molar ratio of Li2O, Al2O3, SiO2 and H2O in the molecular sieve membrane growth mother solution is preferably (10-50):1:(1-10):(300-1000), more preferably 26:1:5:520; when growing a CHA type molecular sieve membrane, the molar ratio of Na2O, K2O, Cs2O, SiO2, Al2O3 and H2O in the molecular sieve membrane growth mother solution is preferably (25-50):(1-10):(1-10):(5-30):1:(300-1000), more preferably 36:3:1.55:20:1:560; when growing an MFI type molecular sieve membrane, the molar ratio of Na2O, SiO2, Al2O3 and H2O in the molecular sieve membrane growth mother liquor is preferably (50-100): (30-100): 1: (300-1500), more preferably 72:45:1:780, and 1-10 wt% of MFI molecular sieve seeds are preferably added to the molecular sieve membrane growth mother liquor; when growing an EMT type molecular sieve membrane, the molar ratio of Na2O, SiO2, Al2O3 and H2O in the molecular sieve membrane growth mother liquor is preferably (10-50): (1-10): 1: (100-1000), more preferably 19:5:1:260; when growing a MOR type molecular sieve membrane, The molar ratio of Na2O, SiO2, Al2O3, and H2O in the molecular sieve membrane growth mother solution is preferably (50-100):(20-100):1:(300-1500), more preferably 73:27:1:792. 1-10 wt% of MOR molecular sieve seed crystals are also preferably added to the molecular sieve membrane growth mother solution. When growing a BEA type molecular sieve membrane, the molar ratio of Na2O, SiO2, Al2O3, and H2O in the molecular sieve membrane growth mother solution is preferably (50-100):(30-100):1:(200-1500), more preferably 82:49:1:852. 1-10 wt% of BEA molecular sieve seed crystals are also preferably added to the molecular sieve membrane growth mother solution.

[0037] In the present invention, when the raw materials for preparing the molecular sieve membrane growth mother solution include a silicon source, an aluminum source, an alkali metal hydroxide and water, the method for preparing the molecular sieve membrane growth mother solution preferably includes the following steps:

[0038] (a) first mixing part of water, part of alkali metal hydroxide and an aluminum source to obtain a first solution;

[0039] (b) mixing the remaining water, the remaining alkali metal hydroxide and the silicon source for a second time to obtain a second solution;

[0040] (c) performing a third mixing of the first solution and the second solution to obtain a molecular sieve membrane growth mother solution.

[0041] In the present invention, the temperature of the first mixing is preferably 20-60°C, and the time is preferably 1-12 hours; the temperature of the second mixing is preferably 20-60°C, and the time is preferably 1-12 hours; the temperature of the third mixing is preferably 10-60°C, and the time is preferably 1-6 hours; the first mixing, second mixing, and third mixing are preferably performed under stirring. In the present invention, the mass ratio of the partial water to the remaining water is preferably 1:0.5-2.

[0042] In the present invention, when the silicon source and aluminum source generate a free radical quencher during the preparation of the molecular sieve membrane growth mother solution, the prepared molecular sieve membrane growth mother solution is preferably subjected to infrared irradiation to remove the generated free radical quencher. For example, when the silicon source includes tetraethyl orthosilicate, tetraethyl orthosilicate hydrolysis produces ethanol, which is a free radical quencher. After the second mixing in step (b), the resulting second solution is preferably subjected to infrared irradiation. The infrared irradiation conditions preferably include: the infrared light source is 20 cm away from the liquid surface of the second solution, and the irradiation power is 100 W. After the infrared irradiation, the water lost in the solution due to the infrared irradiation is preferably replenished.

[0043] In the present invention, when the raw materials for preparing the molecular sieve membrane growth mother solution include a silicon source, an aluminum source and water, the operation of adding alkali metal hydroxide in steps (a) and (b) in the above technical solution is omitted, and the rest of the method for preparing the molecular sieve membrane growth mother solution is the same as the above technical solution.

[0044] After the molecular sieve membrane growth mother solution is prepared, the present invention places the molecular sieve membrane growth mother solution in an open container, immerses a substrate in the molecular sieve membrane growth mother solution, and grows a molecular sieve membrane on the surface of the substrate.

[0045] In the present invention, the substrate preferably includes an inorganic substrate, an organic substrate or a composite substrate; the present invention has no special requirements for the inorganic substrate, the organic substrate or the composite substrate, and any corresponding material familiar to those skilled in the art can be used, for example, the inorganic substrate can be a metal substrate such as titanium sheet, stainless steel mesh, a metal oxide substrate such as iron oxide, aluminum oxide, zirconium oxide, titanium oxide, and an inorganic non-metallic substrate such as glass and ceramics; the organic substrate can be a polymer substrate such as PE film, PP / PE / PP composite film, PP film (Celgard 2400, Celgard 2500 and Celgard M825 and many other models); the composite substrate can be a substrate such as reinforced concrete, FTO glass, fiberglass, fiber reinforced metal, etc. The present invention is applicable to a wide range of substrates, and molecular sieve membranes can be synthesized on substrates that are not resistant to high temperatures and have poor stability (substrates on which molecular sieve membranes cannot be grown by conventional methods).

[0046] In the present invention, before being immersed in the molecular sieve membrane growth mother solution, the substrate is preferably pretreated; the pretreatment method is preferably to treat the substrate in at least one of the following ways: cutting, cleaning, drying, plasma treatment, calcining, loading crystal seeds, and soaking in a treatment solution; the treatment solution preferably includes an acid solution, an alkaline solution, an organic solution or a strong oxidizing solution, and the treatment solution can remove grease, dust and other stains on the surface of the substrate, and modify the surface of the substrate. After modification, the surface of the substrate has rich oxygen-containing or nitrogen-containing groups. These structures are conducive to the nucleation and growth of molecular sieve crystal nuclei, making the substrate more conducive to the attachment of molecular sieve nuclei until they grow into molecular sieve membranes, and enhancing the chemical bonding between the molecular sieve membrane and the substrate, so that the molecular sieve membrane can still be tightly combined with the substrate under extreme conditions (such as scratching or high temperature conditions). In an embodiment of the present invention, the substrate is a metal substrate, an inorganic non-metallic substrate and a polymer substrate. The following is a specific description of the pretreatment method using a metal substrate, an inorganic non-metallic substrate and a polymer substrate as an example:

[0047] When the substrate is a metal substrate, the pretreatment preferably includes sequentially cleaning, drying, and calcining the metal substrate; the calcination temperature is preferably 400-700°C, more preferably 500-650°C, and the time is preferably 3-12 hours, more preferably 3-8 hours. The calcination increases the amount of oxygen-containing species on the surface of the metal substrate, making it easier to grow a molecular sieve membrane. After calcination, the present invention also preferably sequentially ultrasonically cleans and dries the resulting calcined substrate.

[0048] In the present invention, when the substrate is an inorganic non-metallic substrate, the pretreatment preferably includes sequentially cleaning, drying, and immersing the inorganic non-metallic substrate in a piranha solution. In the present invention, the piranha solution is a Piranha solution, a mixed solution of 98% concentrated sulfuric acid and 30% hydrogen peroxide; the immersion time is preferably 20 to 60 minutes; after the immersion, the soaked substrate is preferably washed and dried in sequence, the washing preferably being rinsed with deionized water, and the drying preferably being dried with nitrogen. By immersing in the piranha solution, pollutants on the surface of the inorganic non-metallic substrate can be removed, and the number of hydroxyl groups on the surface of the inorganic non-metallic substrate can be increased, which is more conducive to the growth of the molecular sieve membrane.

[0049] In the present invention, when the substrate is a polymer substrate, the pretreatment preferably includes sequentially washing and drying the polymer substrate, followed by a hydrophilic treatment. The hydrophilic treatment is preferably a first hydrophilic treatment and a second hydrophilic treatment. In the present invention, the treatment liquid for the first hydrophilic treatment is preferably a hydrogen peroxide solution or a persulfate solution. The temperature for the first hydrophilic treatment is preferably 40-80°C, more preferably 50-60°C, and the duration is preferably 1-12 hours, more preferably 1-5 hours. In the present invention, the hydrogen peroxide solution or persulfate solution at a temperature of 40-80°C can generate free radicals, which react with hydrophobic groups such as methylene groups in the polymer substrate to produce hydroxyl groups on the surface of the polymer substrate, thereby constructing a hydrophilic surface on the polymer substrate. After the first hydrophilic treatment, the substrate obtained after the first hydrophilic treatment is preferably washed and dried, and the washing includes sequentially washing with deionized water and ethanol. In the present invention, the treatment liquid for the second hydrophilic treatment is preferably the first treatment liquid or the second treatment liquid. The first treatment liquid is preferably a mixed aqueous solution of acrylamide, an aqueous free radical initiator, and nitric acid, and the second treatment liquid is preferably a polyethyleneimine solution. In the present invention, the mass content of acrylamide in the first treatment liquid is preferably 1-10%, more preferably 1-5%; the aqueous free radical initiator is preferably ammonium cerium nitrate, ammonium cerium sulfate, ammonium persulfate, sodium persulfate, potassium persulfate or hydrogen peroxide, and the concentration of the aqueous free radical initiator in the first treatment liquid is preferably 0.5×10 -4 ~5 × 10 -4 mol / L, more preferably 0.5×10 -4 ~1×10 -4mol / L; the concentration of nitric acid in the first treatment liquid is preferably 0.002-0.05 mol / L, more preferably 0.002-0.01 mol / L; the preparation method of the first treatment liquid is preferably: adding acrylamide to deionized water to obtain an acrylamide aqueous solution; adding an aqueous free radical initiator and nitric acid in sequence to the acrylamide aqueous solution to obtain a first treatment liquid. In the present invention, the mass content of polyethyleneimine in the second treatment liquid is preferably 1%. In the present invention, when the treatment liquid for the second hydrophilic treatment is the first treatment liquid, the temperature of the second hydrophilic treatment is preferably 30-80°C, more preferably 50-60°C, and the time is preferably 1-12h, more preferably 1-5h; when the treatment liquid for the second hydrophilic treatment is the second treatment liquid, the temperature of the second hydrophilic treatment is preferably 40-60°C, and the time is preferably 1-5h. The first hydrophilic treatment generates hydroxyl groups on the surface of the polymer substrate. During the second hydrophilic treatment, acrylamide in the treatment solution reacts with the hydroxyl groups on the surface of the polymer substrate under the action of an aqueous free radical initiator and the acidic conditions provided by nitric acid, thereby constructing a more hydrophilic, amino-rich surface on the polymer substrate. After the second hydrophilic treatment, the resulting substrate is preferably washed and dried in sequence, preferably including a deionized water rinse and an ethanol rinse.

[0050] In the present invention, the method for pretreating the substrate to load the seed crystal preferably includes the following steps:

[0051] mixing the molecular sieve seed crystals with water to obtain a mixed solution;

[0052] adjusting the pH value of the mixed solution to 7-9 to obtain a seed solution;

[0053] The substrate is contacted with the seed solution to load the molecular sieve seed crystals on the surface of the substrate.

[0054] In the present invention, the size of the molecular sieve seed crystal is preferably 100 nm to 1 μm, and the crystal phase of the molecular sieve seed crystal is consistent with the crystal phase of the growing molecular sieve membrane; the present invention has no special requirements for the source of the molecular sieve seed crystal, and commercially available products well known to those skilled in the art or self-prepared products can be used. In the present invention, the water is preferably deionized water, and the mass content of the molecular sieve seed crystal in the mixed solution is preferably 0.1 to 10%; the present invention preferably adds ammonia water to the mixed solution and adjusts the pH value of the mixed solution to 7 to 9. The present invention has no special requirements for the way in which the substrate contacts the seed solution, and can adopt methods well known to those skilled in the art, such as dip coating, brush coating, rubbing coating, vacuum seed coating, slide coating or electrostatic self-assembly.

[0055] In the present invention, the growth method of the molecular sieve membrane is divided into a substrate single-sided growth method and a substrate double-sided growth method. When the growth method of the molecular sieve membrane is a substrate single-sided growth method, and the density of the substrate is greater than the density of the molecular sieve membrane growth mother solution, the operation of immersing the substrate in the molecular sieve membrane growth mother solution is preferably: placing the substrate horizontally and completely submerging it in the molecular sieve membrane growth mother solution; when the growth method of the molecular sieve membrane is a substrate single-sided growth method, and the density of the substrate is less than or equal to the density of the molecular sieve membrane growth mother solution, the operation of immersing the substrate in the molecular sieve membrane growth mother solution is specifically preferably: floating the substrate on the surface of the molecular sieve membrane growth mother solution. When the growth method of the molecular sieve membrane is a substrate double-sided growth method, the operation of immersing the substrate in the molecular sieve membrane growth mother solution is specifically preferably: placing the substrate vertically and completely submerging it in the molecular sieve membrane growth mother solution, or suspending the substrate in the molecular sieve membrane growth mother solution.

[0056] In the present invention, the growth of the molecular sieve membrane is preferably carried out under the conditions of introducing free radicals. In the present invention, the method of introducing free radicals preferably includes: subjecting the molecular sieve membrane growth mother solution soaked with the substrate to at least one of the following treatments: ultraviolet irradiation, sunlight or simulated sunlight irradiation, ultrasound, microwaves, and the addition of free radical initiators. In the present invention, the conditions of ultraviolet irradiation preferably include: ultraviolet wavelength of 290 to 390 nm; irradiation intensity of 0.8 to 20 W / m 2 , more preferably 3 to 10 W / m 2 The distance between the ultraviolet light source and the surface of the mother solution for the growth of the molecular sieve membrane is 1 to 10 cm; the irradiation time is 4 to 36 hours. In the present invention, the intensity of the sunlight or simulated sunlight irradiation is 500 to 1800 W / m 2 , preferably 1000~1800W / m 2 , preferably 8 to 100 hours. In the present invention, the power of the ultrasound is preferably 40 to 400W, and the time is preferably 1 minute to 4 hours. In the present invention, the power of the microwave is preferably 50 to 1800W, and the time is preferably 1 minute to 1 hour. In the present invention, the free radical initiator preferably includes peroxides and / or high-valent metal ion compounds. In the present invention, the peroxide is preferably hydrogen peroxide (which can be combined with Fe 2+ 、Co 2+ 、Mn 2+ 、Cu +The mixture of variable valence metal ions constitutes an oxidation-reduction initiation system to further promote the generation of free radicals), peroxy acid salts (such as peroxydisulfuric acid and its salts, peroxydiphosphoric acid, peroxy acids containing transition metals), organic peroxides (alkyl peroxides, such as tert-butyl hydroperoxide, isopropyl benzene hydroperoxide, etc.; dialkyl peroxides, such as 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3; peroxy esters, such as tert-butyl peroxybenzoate, tert-butyl peroxybenzoate, etc. Peroxyketals, such as 2,2-di(tert-butylperoxy)butane, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, etc.; acyl peroxides, such as dilauroyl peroxide, dibenzoyl peroxide, etc.; peroxydicarbonates, such as dihexadecyl peroxydicarbonate, bis(4-tert-butylcyclohexyl peroxydicarbonate), etc.), organic peroxyacids (with the general structural formula of R-OOH, such as peroxyformic acid, peroxyacetic acid). In the present invention, the high-valent metal ion compound is preferably Pb(OAc)4, Mn(OAc)3 or (NH4)2Ce(NO3)6. In the present invention, the concentration of the free radical initiator in the molecular sieve membrane growth mother solution is preferably 1×10 -4 mol / mL~1×10 -3 mol / mL, more preferably 1×10 -4 mol / mL~5×10 -4 mol / mL; after adding a free radical initiator to the molecular sieve membrane growth mother liquor soaked with a substrate, the growth time of the molecular sieve membrane is preferably 6 to 100 hours. In the present invention, the temperature of the growth of the molecular sieve membrane is room temperature to 60°C; during the growth of the molecular sieve membrane, it is also preferred to cover the molecular sieve membrane growth mother liquor or the container surface with a thin film, a lid, etc. to slow down the volatilization of water, or add an appropriate amount of water. The present invention can accelerate the crystallization of the molecular sieve by introducing free radicals into the reaction system, thereby promoting the growth of the molecular sieve membrane and quickly obtaining a high-quality molecular sieve membrane; the topological structure of the molecular sieve membrane preferably includes LTA, FAU, SOD, BIK, CHA, MFI, EMT, MOR or BEA; the FAU includes FAU-X or FAU-Y.

[0057] The present invention realizes the synthesis of molecular sieve membranes in a non-reactor normal pressure system for the first time. The synthesis process can be carried out at normal pressure and does not need to be synthesized under high pressure conditions in a closed environment; molecular sieve membranes of any size and thickness can be grown and are not limited by the size of the reactor; synthesis can be performed at low temperature (room temperature to 60°C) and is applicable to a wide range of substrates. Molecular sieve membranes can be synthesized on substrates that are not resistant to high temperatures and have poor stability (substrates on which molecular sieve membranes cannot be grown by conventional methods).

[0058] The method for growing molecular sieve membranes in a non-aqueous atmospheric pressure system provided by the present invention is described in detail below with reference to the following examples, but they should not be construed as limiting the scope of protection of the present invention.

[0059] In each embodiment, the sources of the raw materials used are not limited, such as domestic reagents such as Shanghai Sinopharm, Tianjin Guangfu, or foreign reagents such as Aladdin, Sigma-Aldrich, etc.

[0060] Example 1

[0061] A method for growing a molecular sieve membrane in a non-aqueous atmospheric pressure system is as follows:

[0062] The polymer film (PP film) substrate was placed in water for 0.5 h, then placed in ethanol for 0.5 h, and then placed in acetone for 0.5 h. This process was repeated three times. After ultrasonic cleaning, the polymer film substrate was placed in a 60°C oven and dried for 2 h.

[0063] The dried polymer film substrate was placed in a 1 mol / L potassium persulfate aqueous solution and stirred at 60°C for 1 hour for a first hydrophilic treatment, followed by washing with deionized water and ethanol, and drying for later use.

[0064] Acrylamide was added to deionized water to prepare a solution with a solute content of 1 wt%, and then 0.5×10 -4 mol / L ceric ammonium nitrate aqueous free radical initiator, and finally 0.002 mol / L nitric acid to obtain a treatment solution; the polymer film substrate dried after the first hydrophilic treatment was placed in the treatment solution, stirred at 50°C for 1 hour to perform a second hydrophilic treatment, and then washed with deionized water and ethanol respectively, and dried to obtain a pretreated polymer film substrate for use;

[0065] Sodium hydroxide, sodium silicate nonahydrate, and water were mixed in appropriate proportions to form a silicon source solution. An aluminum source solution was prepared by mixing sodium hydroxide, sodium aluminate, and water in appropriate proportions. The aluminum source solution was added to the silicon source solution and stirred continuously for 2 hours to obtain a molecular sieve membrane growth mother solution. The molar ratio of the oxides and solvent components in the molecular sieve membrane growth mother solution was 30% Na₂O: 2% SiO₂: Al₂O₃: 400% H₂O. A pretreated polymer film substrate was placed on the surface of the molecular sieve membrane growth mother solution and subjected to ultrasonic treatment at 120 W for 1 hour while heating at 40°C. The substrate was then placed in an oven at 45°C for 7 hours. The polymer film substrate was then removed, rinsed repeatedly with deionized water until neutral, and dried in air at 60°C to obtain a polymer film with LTA molecular sieve membranes, designated as LTA molecular sieve membrane / PP membrane.

[0066] Figure 1 shows the XRD spectrum and SEM image of the LTA molecular sieve membrane / PP membrane prepared in Example 1. (a) is the XRD spectrum of the LTA molecular sieve membrane / PP membrane, (b) is the SEM image of the LTA molecular sieve membrane / PP membrane, and (c) is the cross-sectional SEM image of the LTA molecular sieve membrane / PP membrane. The upper portion of (d) is a physical photograph of the LTA molecular sieve membrane / PP membrane sample, and the lower portion is a physical photograph of the sample prepared using the existing technology (using a reaction temperature of 100°C and a hydrothermal reactor). Figure 1 (a) proves that the molecular sieve membrane in this sample is in the LTA phase. (b) shows that the LTA molecular sieve membrane is continuous and dense. (c) shows that the membrane thickness is 3μm. (d) shows that the size of the LTA molecular sieve membrane / PP membrane prepared in the laboratory is much larger than that of the sample prepared using the reactor, which can achieve the preparation of molecular sieve membranes of any reaction size.

[0067] Example 2

[0068] A method for growing a molecular sieve membrane in a non-aqueous atmospheric pressure system is as follows:

[0069] The stainless steel mesh substrate was placed in water and ethanol in sequence for ultrasonic treatment for 0.5 h, and then placed in an oven at 100° C. for 2 h to obtain a pretreated stainless steel mesh substrate;

[0070] Sodium hydroxide, sodium silicate nonahydrate and water were mixed in proportion to prepare a silicon source solution, sodium hydroxide, sodium aluminate and water were mixed in proportion to prepare an aluminum source solution, the aluminum source solution was added to the silicon source solution, and the mixture was stirred for 3 hours to obtain a molecular sieve membrane growth mother solution. The molar ratio of the oxides and solvents of each component in the molecular sieve membrane growth mother solution was: 45Na2O: 2SiO2: Al2O3: 600H2O. The pretreated stainless steel mesh substrate was placed vertically in the molecular sieve membrane growth mother solution and placed outdoors under sunlight (average light intensity 1000W / m 2 ) for 20 to 24 hours (which can be divided into 2 to 3 days). The stainless steel mesh substrate was then removed and repeatedly rinsed with deionized water until neutral. After drying in air at 60° C., a stainless steel mesh with an LTA molecular sieve membrane was obtained, which was designated as LTA molecular sieve membrane / stainless steel mesh.

[0071] Figure 2 shows the XRD pattern and SEM images of the LTA molecular sieve membrane / stainless steel mesh prepared in Example 2. (a) shows the XRD pattern of the LTA molecular sieve membrane / stainless steel mesh, while (b) and (c) show the SEM images of the LTA molecular sieve membrane / stainless steel mesh. Figure 2 (a) demonstrates that the molecular sieve membrane in this sample is in the LTA phase, while (b) and (c) demonstrate that the LTA molecular sieve membrane is continuous and dense.

[0072] Example 3

[0073] A method for growing a molecular sieve membrane in a non-aqueous atmospheric pressure system is as follows:

[0074] The glass substrate was cleaned according to the steps described in Example 1 and then dried in an oven at 100° C. for 2 h. The cleaned and dried glass substrate was then immersed in piranha solution for approximately 30 min, rinsed with a large amount of deionized water, and dried using nitrogen gas to obtain a pretreated glass substrate for later use.

[0075] A silicon source solution was prepared by mixing sodium hydroxide, silica sol, and water in appropriate proportions. An aluminum source solution was then prepared by mixing sodium hydroxide, aluminum powder, and water in appropriate proportions. The aluminum source solution was added to the silicon source solution and stirred continuously for 4 hours to obtain a molecular sieve membrane growth mother solution. The molar ratio of the oxides and solvent components in the molecular sieve membrane growth mother solution was 5 Na₂O: 2 SiO₂: Al₂O₃: 130 H₂O. A pretreated glass substrate was placed in the molecular sieve membrane growth mother solution, which was then crystallized in a microwave oven at 600W for 20 minutes. The glass substrate was then removed, rinsed repeatedly with deionized water until neutral, and dried in air at 60°C to obtain a glass substrate with an LTA molecular sieve membrane, designated as LTA molecular sieve membrane / glass.

[0076] Figure 3 shows the XRD spectrum and SEM image of the LTA molecular sieve membrane / glass sample prepared in Example 3. (a) shows the XRD pattern of the LTA molecular sieve membrane / glass sample, and (b) shows the SEM image of the LTA molecular sieve membrane / glass sample. Figure 3 (a) demonstrates that the molecular sieve membrane in this sample is in the LTA phase, while (b) shows that the LTA molecular sieve membrane is continuous and dense.

[0077] Example 4

[0078] A method for growing a molecular sieve membrane in a non-aqueous atmospheric pressure system is as follows:

[0079] The PP / PE composite polymer film substrate was cleaned and dried according to the method of Example 1, and then placed in a 1 mol / L potassium persulfate aqueous solution and stirred at 60° C. for 1 hour for a first hydrophilic treatment. The substrate was then washed with deionized water and ethanol, and dried for later use.

[0080] Acrylamide was added to deionized water to prepare a solution with a solute content of 1 wt%, and then 0.5 × 10 -4 mol / L of ceric ammonium nitrate aqueous free radical initiator, and finally 0.002 mol / L of nitric acid to obtain a treatment solution; the polymer film substrate dried after the first hydrophilic treatment was placed in the treatment solution and stirred at 50°C for 1 hour to perform a second hydrophilic treatment, and then washed with deionized water and ethanol respectively, and dried to obtain a pretreated PP / PE substrate for use;

[0081] Sodium hydroxide, sodium silicate nonahydrate and water are mixed in proportion to form a silicon source solution, sodium hydroxide, sodium aluminate and water are mixed in proportion to form an aluminum source solution, the aluminum source solution is added to the silicon source solution, and the mixture is stirred for 2 hours to obtain a molecular sieve membrane growth mother solution, wherein the molar ratio of the oxides and the solvent of each component in the molecular sieve membrane growth mother solution is: 45Na2O: 2SiO2: Al2O3: 600H2O; a pretreated PP / PE substrate is placed on the surface of the molecular sieve membrane growth mother solution, and then placed in an oven at 45°C and irradiated with a 365nm ultraviolet lamp at an irradiation intensity of 10W / cm 2 , 10 cm away from the surface of the zeolite membrane growth mother liquor, and react for 4 h and 6 h, respectively. Then, the PP / PE substrate membrane was removed and repeatedly rinsed with deionized water until neutral. After drying in air at 60°C, a PP / PE membrane with a zeolite membrane was obtained, which was recorded as zeolite membrane / PP / PE membrane.

[0082] FIG4 is an EPR spectrum of the molecular sieve membrane growth mother solution of Example 4. The test shows that hydroxyl radicals are generated in the molecular sieve membrane growth mother solution.

[0083] Figure 5 shows SEM images of the zeolite membranes of Example 4 after UV irradiation for different times. Figure 5 (a) shows an SEM image of the zeolite membrane after UV irradiation for 4 hours, and (b) shows an SEM image of the zeolite membrane after UV irradiation for 6 hours. As can be seen from Figure 5, the zeolite membrane has become relatively dense after 4 hours of reaction.

[0084] Example 5

[0085] A method for growing a FAU-Y molecular sieve membrane in a non-aqueous atmospheric pressure system is as follows:

[0086] The clean titanium sheet was placed in a muffle furnace and calcined at 550°C for 3 hours, then ultrasonically placed in water for 0.5 hours, then ultrasonically placed in ethanol for 0.5 hours, and then ultrasonically placed in acetone for 0.5 hours. This process was repeated three times. After ultrasonic cleaning, the titanium dioxide sheet was placed in an oven at 80°C and dried for 2 hours to obtain a pretreated substrate.

[0087] Sodium hydroxide, AS-40 silica sol, and water were mixed in proportion to form a silicon source solution. Sodium hydroxide, aluminum powder, and water were mixed in proportion to form an aluminum source solution. The aluminum source solution was added to the silicon source solution and stirred for 12 hours to obtain a molecular sieve membrane growth mother solution. The molar ratio of the oxides and solvent components in the molecular sieve membrane growth mother solution was 70 Na2O: 20 SiO2: Al2O3: 1400 H2O. The pretreated substrate was placed on the surface of the molecular sieve membrane growth mother solution and then placed in a 60°C oven. A 365nm ultraviolet lamp was used with an irradiation intensity of 10W / cm 2The substrate was removed and repeatedly rinsed with deionized water until neutral. After drying in air at 60°C, a titanium sheet with a molecular sieve membrane was obtained, designated FAU-Y molecular sieve membrane / titanium sheet.

[0088] Figure 6 shows the XRD spectrum and SEM images of the FAU-Y molecular sieve membrane / titanium sheet sample prepared in Example 5. (a) shows the XRD pattern of the FAU-Y molecular sieve membrane / titanium sheet sample, (b) shows the SEM image of the FAU-Y molecular sieve membrane / titanium sheet sample, and (c) shows the cross-sectional SEM image of the FAU-Y molecular sieve membrane / titanium sheet sample. Figure 6 (a) demonstrates that the molecular sieve membrane in this sample is a FAU-Y phase, (b) shows that the FAU-Y molecular sieve membrane is continuous and dense, and (c) shows that the membrane thickness is 10 μm.

[0089] Example 6

[0090] A method for growing a SOD molecular sieve membrane in a non-aqueous atmospheric pressure system is as follows:

[0091] The glass substrate was placed in water and ethanol for ultrasonic treatment for 0.5 h, then dried in a 100°C oven for 2 h, taken out and immersed in piranha solution for about 30 min, then rinsed with a large amount of deionized water and dried with nitrogen to obtain a pretreated glass substrate for later use;

[0092] Sodium hydroxide, sodium silicate nonahydrate, and water were mixed in proportion to prepare a silicon source solution. Sodium hydroxide, sodium aluminate, and water were mixed in proportion to prepare an aluminum source solution. The aluminum source solution was added to the silicon source solution and stirred for 6 hours to obtain a molecular sieve membrane growth mother solution. The molar ratio of the oxides and solvent components in the molecular sieve membrane growth mother solution was 75 Na2O: 17 SiO2: Al2O3: 650 H2O. Hydrogen peroxide solution was added to the mother solution at a concentration of 5×10 -4 mol / mL. The pretreated glass substrate was placed in the zeolite membrane growth mother liquor and then placed in a 45°C oven for 36 hours. The glass substrate was then removed and repeatedly rinsed with deionized water until neutral. After drying in air at 60°C, a glass substrate with a zeolite membrane was obtained, which was designated as SOD zeolite membrane / glass.

[0093] Figure 7 is an XRD spectrum and SEM image of the SOD molecular sieve film / glass sample prepared in Example 6, (a) is the XRD pattern of the SOD molecular sieve film / glass sample, (b) is the SEM image of the SOD molecular sieve film / glass sample, and (c) is the cross-sectional SEM image of the SOD molecular sieve film / glass sample. Figure 7 (a) shows that the molecular sieve film in the sample is in the SOD phase, (b) shows that the SOD molecular sieve film is continuous and dense, and (c) shows that the film thickness is 8 μm.

[0094] Example 7

[0095] A polymer film (PP / PE / PP film, Celgard 2325) was selected as the substrate, and the UV lamp irradiation operation was omitted. Other operations were the same as those in Example 4.

[0096] FIG8 is an EPR spectrum of the mother liquor for the growth of the molecular sieve membrane in Example 7. The test shows that no hydroxyl radical signal is detected in the reaction mother liquor.

[0097] Figure 9 shows SEM images of the zeolite membranes of Example 7 after different reaction times. Figure 9 (a) shows an SEM image of the zeolite membrane after 4 hours of reaction, (b) shows an SEM image of the zeolite membrane after 6 hours of reaction, and (c) shows an SEM image of the zeolite membrane after 8 hours of reaction. As can be seen from Figure 9, the crystallization progress of the zeolite membrane is slower than that of Example 4 (Figure 5), and a longer time is required to grow a continuous and dense zeolite membrane.

[0098] It can be seen from the above embodiments and comparative examples that the present invention realizes the synthesis of molecular sieve membranes in a non-reactor normal pressure system, without the need for synthesis under high pressure conditions in a closed environment, thereby being able to grow molecular sieve membranes of any size without being restricted by the size of the reactor; and it can be synthesized at low temperatures, and is applicable to a wide variety of substrates. Molecular sieve membranes can also be synthesized on a variety of heat-sensitive and poorly stable substrates on which molecular sieve membranes cannot be grown by conventional methods, such as on the surface of a polymer substrate.

[0099] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for growing a molecular sieve membrane in a non-aqueous atmospheric pressure system, comprising the following steps: Prepare a molecular sieve membrane growth mother solution; the molar ratio of alkali metal oxide, Al2O3, SiO2 and H2O in the molecular sieve membrane growth mother solution is (1-100):1:(1-25):(50-2000), and the alkali metal oxide is one or more of Na2O, K2O, Li2O and Cs2O; The molecular sieve membrane growth mother solution is placed in an open container, a substrate is immersed in the molecular sieve membrane growth mother solution, and a molecular sieve membrane is grown on the surface of the substrate; the growth temperature is room temperature to 60°C.

2. The method according to claim 1, characterized in that The substrate includes an inorganic material substrate, an organic material substrate or a composite material substrate; before being immersed in the molecular sieve membrane growth mother solution, the substrate is also pretreated; the pretreatment method is to treat the substrate in at least one of the following ways: cutting, cleaning, drying, plasma treatment, calcination, loading crystal seeds, and immersing in a treatment solution; the treatment solution includes an acid solution, an alkaline solution, an organic solution or a strong oxidizing solution.

3. The method according to claim 1, characterized in that The growth is carried out under the conditions of introducing free radicals.

4. The method according to claim 3, characterized in that The method for introducing free radicals comprises treating the molecular sieve membrane growth mother solution soaked with the substrate by at least one of the following methods: ultraviolet irradiation, sunlight or simulated sunlight irradiation, ultrasound, microwave, and adding a free radical initiator.

5. The method according to claim 4, characterized in that The ultraviolet wavelength of the ultraviolet radiation is 290-390nm, and the irradiation intensity is 0.8-20W / m 2 The irradiation time is 4 to 36 hours.

6. The method according to claim 4 or 5, characterized in that: The distance between the ultraviolet light source of the ultraviolet irradiation and the surface of the molecular sieve membrane growth mother liquid is 1 to 10 cm.

7. The method according to claim 4, characterized in that The light intensity of the sunlight or simulated sunlight is 500-1800 W / m 2 The irradiation time is 8 to 100 hours.

8. The method according to claim 4, characterized in that The power of the ultrasound is 40-400W, and the time is 1min-4h.

9. The method according to claim 4, characterized in that The power of the microwave is 50-1800W, and the time is 1min-1h.

10. The method according to claim 4, characterized in that The free radical initiator includes peroxide and / or high-valent metal ion compound; the concentration of the free radical initiator in the molecular sieve membrane growth mother solution is 1×10 -4 mol / mL~1×10 -3 mol / mL; after adding the free radical initiator to the molecular sieve membrane growth mother solution immersed in the substrate, the growth time of the molecular sieve membrane is 6 to 100 hours.

11. The method according to claim 10, characterized in that The high-valent metal ion compound is Pb(OAc)4, Mn(OAc)3 or (NH4)2Ce(NO3)6.

12. The method according to claim 1 or 4, characterized in that: The topological structure of the molecular sieve membrane includes LTA, FAU, SOD, BIK, CHA, MFI, EMT, MOR or BEA.

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