Acidic form zeolite molecular sieve without graft modification and application thereof as emulsifier

Abstract

The application provides a grafted modification-free acidic form zeolite molecular sieve and application thereof as an emulsifier. First, a grafted modification-free acidic form zeolite molecular sieve for emulsification is provided, which is obtained by acid treatment of a specific morphology zeolite; the acid treatment is ammonium exchange or liquid acid solution treatment. Further, the grafted modification-free acidic form zeolite molecular sieve can be used for preparing an emulsifier, and in the absence of surface grafting and without adding a surfactant and an electrolyte, an immiscible system composed of a low-polarity oil phase such as a hydrocarbon, a high-carbon alcohol, an aldehyde, a ketone and the like and a high-polarity water / alcohol phase such as water, a low-carbon alcohol and the like is emulsified, the problem of poor emulsification performance of the existing grafted modification-free zeolite molecular sieve material is solved, and the cost of preparing the emulsifier is lower than that of a surface grafted modification zeolite molecular sieve, so that the grafted modification-free zeolite molecular sieve can be used as a new intrinsic Pickering emulsifier.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of materials, more particularly, to a non-grafting modified acidic form zeolite molecular sieve and its application as an emulsifier. BACKGROUND

[0002] Since the interface area of emulsion droplets is very large, emulsions without emulsifiers are thermodynamically unstable systems. In order to stabilize the emulsion droplets, low-molecular-mass surfactants or surface-active polymers are usually wrapped in the preparation to reduce the interfacial tension between the phases. But this is not the only effective means, another method of stabilizing droplets has been revealed, that is, by using solid particles (usually nanoscale or micrometer scale) to replace surfactants. Therefore, solid particle-stabilized emulsions are called Pickering emulsions; this emulsification phenomenon is called Pickering emulsification; solid particles with emulsifying ability are called Pickering emulsifiers. Pickering emulsions stabilized by solid particles have recently received extensive attention due to their multifunctionality, non-toxicity and recyclability, which provides an environmentally friendly alternative to traditional surfactant-stabilized emulsions and has a wide range of applications. These emulsions are stabilized by solid particles at the oil-water interface, which act as a barrier to prevent droplet coalescence and maintain the emulsion system. The particle size, shape, surface properties and concentration of solid emulsifiers play a crucial role in the microstructure and stability of the emulsion. First, nanoscale spherical, layered and fibrous structures are most commonly used to stabilize emulsions. The common advantage of these three structures is that they can maximize their outer surface as an adsorption surface for phase boundaries. Second, amphiphilic surface functional groups are also a prerequisite for the formation of stable emulsions. Materials with these two properties can reduce the interfacial tension and provide high stability energy for the emulsion system.

[0003] Most emulsifiers do not have amphiphilicity naturally, in order to endow the emulsifiers with amphiphilicity, the surface of SiO2 nanoparticles, MOFs, zeolites, polyoxometalates, clays are usually grafted with surfactants / silane molecules to obtain amphiphilicity. Surface grafting is to connect or grow organic groups to the surface groups of solid particles through chemical reactions. Certain materials can exhibit intrinsic amphiphilicity, for example, attapulgite, graphene oxide, g-C3N4, carbon nanotubes, which can emulsify two-phase systems without grafting. Other emulsifiers with intrinsic amphiphilicity have not been reported.

[0004] Zeolite molecular sieve materials were first discovered in nature as minerals, which absorbed water vapor during heating and then the water vapor was gasified, thus the phenomenon of boiling was observed, so it was called zeolite. At present, there are still a large number of molecular sieve minerals in nature, which are called natural zeolites. In the 1940s, researchers synthesized artificial zeolites by hydrothermal synthesis method. The early zeolites were all silicates in chemical composition, and other elements such as aluminum, boron, gallium and the like existed in the structure as framework doping elements. In 1982, researchers also found that phosphates can also have similar structures. Later, people successively found that germanates and even sulfides can also have similar structures. Therefore, the definition of zeolite is mainly based on its structure. That is: an inorganic material formed by tetrahedra as the structural unit, which has a four-connected, infinite network structure with pores. The tetrahedron center atom (also called T atom) can be silicon, germanium, aluminum, boron, gallium, etc., and the vertex atom can be oxygen, nitrogen, sulfur, etc. The website of International Zeolite Association (www.iza-structure.org) has collected all the recognized zeolite molecular sieve structures. The material with this type of structure is called zeolite. Due to the clear crystal structure of the zeolite structure and the sub-nanometer molecular size level of the pore, it has a sieving effect on molecules of different sizes and shapes. Therefore, it is called molecular sieve. However, in recent years, the number of materials with clear structure and pore materials has been increasing, such as MOF (Metal Organic Framework) materials, COF (Covalent Organic Framework), ordered mesoporous materials, and ordered porous carbon materials, which also have molecular sieving effect, and are also called molecular sieves.

[0005] Zeolite molecular sieves are widely used in adsorption / separation and heterogeneous catalysis due to their porous structure, thermal stability, and adjustable active sites. Zeolite materials are considered to be hydrophilic (low Si / Al ratio) or lipophilic (high Si / Al ratio). Traditionally, zeolites and other solid particles with single hydrophilic / lipophilic properties are not considered to be emulsifiable. Therefore, surface modification is needed, i.e. grafting with organosilane, surfactant or other additives to endow zeolite with the ability as an emulsifier. In other words, traditionally, zeolite is not an intrinsic Pickering emulsifier. Zeolite molecular sieves without surface grafting treatment do not have the ability to emulsify oil-water two-phase systems, or in other words, the stability of the formed emulsion is poor. Although surface grafting modification can endow zeolite with Pickering emulsification performance, a significant disadvantage of surface grafting modification is that the organic surface material restricts its thermal stability, and greatly increases the preparation cost of the material as an emulsifier. Therefore, it is of great significance to provide a zeolite molecular sieve material without surface grafting modification as an emulsifier. SUMMARY

[0006] The present application aims to overcome the above-mentioned defects and deficiencies existing in the prior art, and provide a grafted modification-free acid form of zeolite molecular sieve and its application as an emulsifier.

[0007] The above-mentioned object of the present application is realized by the following technical solutions:

[0008] The present application first provides a grafted modification-free acid form of zeolite molecular sieve for emulsification, which is obtained by acid treatment of zeolite with a sheet-like, fibrous, linear, strip-like, rod-like or tubular particle morphology; the acid treatment is ammonium exchange or liquid acid solution treatment.

[0009] That is, the acid form of zeolite is the form after ammonium exchange or liquid acid (HCl, HNO3, etc.) solution treatment, which is called the acid form of zeolite molecular sieve.

[0010] The silicate zeolite molecular sieve has a framework negative charge, so there are non-framework alkali metal ions, i.e. free ions in the channel, which can be exchanged into the solution by other ions. In order to impart the property of solid acid to the zeolite molecular sieve, ammonium salt is usually used for solution ion exchange with the silicate zeolite molecular sieve. The ammonium ion (NH4 + ) is exchanged into the molecular sieve channel, and after the calcination step, the ammonia molecule (NH3) escapes, and the H + ion remains in the channel and combines with the Al-O-Si group to form an Al-OH-Si group, so that the zeolite molecular sieve becomes a solid acid (also known as a protonic acid).

[0011] Further, the zeolite is an aluminosilicate zeolite.

[0012] Further, the particle morphology of the zeolite is sheet-like or fibrous.

[0013] Preferably, the sheet-like zeolite is a MWW zeolite molecular sieve.

[0014] Preferably, the fibrous zeolite is a MOR zeolite molecular sieve.

[0015] Further, the ammonium source for ammonium exchange is any soluble ammonium salt such as ammonium nitrate, ammonium sulfate, ammonium chloride or ammonium carbonate.

[0016] Preferably, the ammonium source for ammonium exchange is ammonium nitrate.

[0017] Further, the liquid acid is a strong acid and a medium-strong acid such as nitric acid, hydrochloric acid, sulfuric acid or phosphoric acid.

[0018] Preferably, the liquid acid is nitric acid.

[0019] Further, the ammonium exchange step comprises mixing the zeolite with an ammonium ion-containing solution, refluxing, calcining to obtain the acid-form zeolite molecular sieve without grafting modification.

[0020] Preferably, the solid-liquid weight ratio of the zeolite to the ammonium ion-containing solution is 1:50.

[0021] Preferably, the ammonium ion-containing solution is an ammonium nitrate solution.

[0022] Preferably, the refluxing is refluxing at 80℃ for 3h.

[0023] Further, the liquid acid solution treatment step comprises mixing the zeolite with a liquid acid, heating and reacting, and after the reaction, washing, drying and calcining to obtain the acid-form zeolite molecular sieve without grafting modification.

[0024] Preferably, the liquid acid is nitric acid.

[0025] Preferably, the heating and reacting is heating and reacting at 80℃ for 10h.

[0026] Preferably, the calcining is at 550℃.

[0027] The present application also provides that the acid-form zeolite molecular sieve without grafting modification as described above can achieve effective water-oil system emulsification effect. Therefore, the present application also provides the use of the acid-form zeolite molecular sieve without grafting modification as described above in Pickering emulsification or preparation of Pickering emulsifier.

[0028] Further, the Pickering emulsification is emulsification of a non-miscible system composed of a low-polarity oil phase and a high-polarity water / alcohol phase.

[0029] Preferably, the low-polarity oil phase is a hydrocarbon, a high-carbon alcohol, an aldehyde or a ketone substance.

[0030] Preferably, the low-polarity oil phase is cyclohexane, dodecane, toluene, dodecanal or ethyl acetate.

[0031] Further, the high-polarity water / alcohol phase is water or a low-carbon alcohol substance.

[0032] Preferably, the low-carbon alcohol substance is ethylene glycol.

[0033] Specifically, the Pickering emulsification is adding the acid-form zeolite molecular sieve without grafting modification as described above to the non-miscible system, ultrasonicating and homogenizing to generate a stable Pickering emulsion.

[0034] The application also provides an intrinsic Pickering emulsifier, which contains the above-mentioned any ungrafted modified acidic form zeolite molecular sieve.

[0035] Further, the intrinsic Pickering emulsifier is used for emulsifying a non-miscible system composed of a low-polarity oil phase and a high-polarity water / alcohol phase.

[0036] Compared with the prior art, the application has the following beneficial effects:

[0037] The application provides an ungrafted modified acidic form zeolite molecular sieve and application thereof as an emulsifier. First, an ungrafted modified acidic form zeolite molecular sieve for emulsification is provided, which is obtained by acid treatment of a zeolite molecular sieve having a lamellar, fibrous, linear, banded, rod-shaped or tubular particle morphology; the acid treatment includes ammonium exchange or liquid acid solution treatment. Further, the ungrafted modified acidic form zeolite molecular sieve can be used to prepare an emulsifier, which has good emulsifying performance for a non-miscible system composed of a low-polarity oil phase and a high-polarity water / alcohol phase without surface grafting, without adding a surfactant or an electrolyte, solves the problem of poor emulsifying performance of the prior art ungrafted modified zeolite molecular sieve material, and has a lower cost than the surface grafted modified zeolite molecular sieve for preparing an emulsifier, and can be used as a new intrinsic Pickering emulsifier. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 XRD and electron micrograph of MWW zeolite.

[0039] Figure 2 XRD and electron micrograph of MOR zeolite.

[0040] Figure 3 XRD of MWW zeolite before ammonium exchange, after ammonium exchange and after HNO3 acid treatment, electron micrograph, emulsifying effect and light micrograph of MWW zeolite after ammonium exchange and after HNO3 acid treatment.

[0041] Figure 4 Emulsifying effect and light micrograph of MWW zeolite after ammonium exchange on dodecane / water, toluene / water, dodecanol / ethylene glycol and ethyl acetate / water systems.

[0042] Figure 5 XRD, electron micrograph, emulsifying effect and light micrograph of commercial lamellar MWW zeolite after ammonium exchange on cyclohexane / water and dodecane / water systems.

[0043] Figure 6 XRD, electron micrograph, emulsifying effect and light micrograph of fibrous MOR zeolite after ammonium exchange on cyclohexane / water systems.

[0044] Figure 7 XRD, electron microscope images and emulsification performance comparison of NaHCO3 treated hydrogen type ZSM-5 zeolite Na-IRZ-MFI001, commercial hydrogen type ZSM-5 zeolite IRZ-MFI001, HNO3 treated hydrogen type ZSM-5 zeolite HNO3-IRZ-MFI001.

[0045] Figure 8 XRD, electron microscope images and emulsification performance comparison of NaHCO3 treated hydrogen type zeolite Na-MOR (block morphology), commercial hydrogen type zeolite H-MOR, HNO3 treated hydrogen type zeolite HNO3-H-MOR.

[0046] Figure 9 XRD, electron microscope images and emulsification performance comparison of NaHCO3 treated hydrogen type zeolite NaY (4.8), commercial hydrogen type zeolite HY (4.8), HNO3 treated hydrogen type zeolite HNO3-HY (4.8).

[0047] Figure 10 XRD, electron microscope images and emulsification performance comparison of Beta zeolite molecular sieve, SBA-15 mesoporous molecular sieve and SAPO-34 zeolite molecular sieve. DETAILED DESCRIPTION

[0048] The present application will be further described in conjunction with the accompanying drawings and specific examples, but the examples do not limit the present application in any form. Unless otherwise specified, the reagents, methods and equipment used in the present application are conventional reagents, methods and equipment in the technical field.

[0049] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0050] Example 1

[0051] Taking a sheet-like molecular sieve with MWW structure (see www.iza-structure.org) as an example, materials with different condensation degrees and different crystallinities are also called MCM-22, MCM-49, MCM-56, etc.

[0052] The MWW sheet layer zeolite powder is synthesized by hydrothermal synthesis, and the specific synthesis steps are as follows:

[0053] Silica sol (40 wt% SiO2, Sigma-Aldrich), sodium hydroxide (98.0 wt% NaOH, Aladdin), sodium aluminate (43 wt% Al2O3, 35 wt% Na2O), hexamethyleneimine (98 wt% HMI, TCI) and distilled water were used as starting materials for the synthesis of zeolite particles. An aluminosilicate gel was synthesized with a molar ratio of SiO2:Al2O3:HMI:Na2O:H2O = 1:0.05:0.5:0.09:40 and reacted at 160 °C for 168 h, the sample was collected by filtration, washed with water, and dried at 60 °C overnight. The organic material was removed by calcination at 550 °C for 6 h under ambient atmosphere to obtain MWW lamellar zeolite powder, the XRD and electron microscope photos of which are shown in Figs. 1 and 2, respectively. Figure 1

[0054] Ammonium exchange treatment: The procedure was as follows: the calcined sample was subjected to ammonium ion exchange with 1 mol / L ammonium acetate solution at a solid-liquid weight ratio of 1:50, refluxed at 80 °C for 3 h, repeated twice, and then calcined to obtain the acidic form of MWW zeolite molecular sieve.

[0055] Example 2

[0056] The procedure was basically the same as in Example 1, except that the MWW lamellar zeolite powder was prepared using nitric acid treatment, the specific steps of which were as follows:

[0057] The MWW lamellar zeolite powder was treated with 1 mol / L nitric acid and heated at 80 °C for 10 h, washed again and dried. Finally, the sample was calcined at 550 °C to obtain the acidic form of MWW zeolite molecular sieve.

[0058] Example 3

[0059] The procedure was basically the same as in Example 1, except that the zeolite molecular sieve used for ammonium exchange treatment was a commercial (Jiangsu Lvkexin Material Co., Ltd., product model lk011, Si / Al = 14, SiO2 / Al2O3= 28) lamellar MWW zeolite molecular sieve, which was obtained in the acidic form.

[0060] Example 4

[0061] Taking a fibrous molecular sieve with MOR structure as an example, MOR type zeolite is also known as mordenite, Mordenite, etc.

[0062] The MOR fibrous zeolite powder was synthesized by hydrothermal synthesis, the specific synthesis steps of which were as follows:

[0063] ​Silica sol (40 wt% Si02, Sigma-Aldrich), sodium hydroxide (98.0 wt% NaOH, Aladdin), sodium aluminate (43 wt% Al203, 35 wt% Na20), and distilled water were used as starting materials for the synthesis of zeolite particles. The synthesis molar ratio was Si02 / 0.2 Al203 / 0.3 Na20 / 22.5 H20 (i.e. Si02: Al203: Na20: H20 = 1 : 0.2 : 0.3 : 22.5) was fed into a 165 °C oven for 48 h. The sample was collected by filtration, washed with water, and dried at 60 °C overnight to obtain MOR fibrous zeolite molecular sieve powder, whose XRD and electron microscope photos are shown in FIGS. 1 and 2, respectively. Figure 2

[0064] Ammonium exchange treatment: The procedure was as follows: MOR fibrous zeolite molecular sieve powder sample was treated with 1 mol / L ammonium acetate solution with a solid-liquid weight ratio of 1:50 for ammonium ion exchange at 80 °C for 3 h, repeated twice, and then calcined to obtain an acidic form of MWW zeolite molecular sieve.

[0065] Example 5

[0066] Example 4 was basically the same, except that the MOR fibrous zeolite molecular sieve powder obtained was treated with nitric acid, and the specific steps were as follows:

[0067] The MOR fibrous zeolite molecular sieve powder was treated with 1 mol / L nitric acid and heated at 80 °C for 10 h, washed again and dried. Finally, the sample was calcined at 550 °C to obtain an acidic form of MOR zeolite molecular sieve.

[0068] Test Example 1

[0069] The hydrothermally synthesized MWW lamellar zeolite molecular sieve, the ammonium-exchanged and nitric acid-treated MWW zeolite molecular sieve (i.e. the zeolite molecular sieve obtained in Examples 1-2) were subjected to X-ray diffraction analysis, and the structure of the ammonium-exchanged and nitric acid-treated MWW zeolite molecular sieve was observed by electron microscopy. The acid-treated molecular sieve material was used in an emulsification process and observed by light microscopy. The emulsification process steps were as follows:

[0070] 3 mL of deionized water and 20 mg of acid-treated zeolite molecular sieve powder were mixed with 3 mL of cyclohexane in a 10 mL glass bottle. The mixture was ultrasonically treated for 10 minutes, then homogenized to generate a stable Pickering emulsion. After standing for 24 hours, a photo was taken and light microscopy was performed.

[0071] Further, the lamellar MWW zeolite molecular sieve subjected to ammonium exchange treatment in Example 1 was used to emulsify other oil-water systems. The emulsification process steps were as follows:

[0072] ​The 3 mL deionized water or ethylene glycol and 20 mg of the acid treated zeolite molecular sieve powder were mixed with 3 mL of the oil phase (dodecane / toluene / dodecanal / ethyl acetate) in a 10 mL glass bottle, i.e. the zeolite molecular sieve powder was mixed with dodecane / water, toluene / water, dodecanal / ethylene glycol, ethyl acetate / water four systems respectively. The mixture was ultrasonically treated for 10 minutes, and then homogenized to generate a stable Pickering emulsion. After standing for 24 hours, a photo was taken and optical microscopy was performed.

[0073] The XRD, electron microscopy observation structure and emulsification results of the ammonium exchanged and nitric acid treated acidic form MWW zeolite molecular sieve are shown in Figure 3 The XRD results show that the MWW zeolite molecular sieve after calcination and acid treatment has good crystallinity, and the electron micrograph shows that the two samples have obvious lamellar structure. These are important prerequisites for the emulsification performance of the zeolite molecular sieve material. The material is applied to the emulsification system of water / cyclohexane, and the above emulsification operation is performed, as shown in Figure 3 The photo shows that after homogenization and standing for 24 hours, the emulsion state can still be maintained. The corresponding optical microscope photo shows that the emulsion is an oil-in-water emulsion, and the emulsion droplets can stably exist. It shows that the ammonium exchanged and nitric acid treated acidic form MWW zeolite molecular sieve both have good emulsification performance.

[0074] The emulsification effect of the ammonium exchanged MWW zeolite molecular sieve on dodecane / water, toluene / water, dodecanal / ethylene glycol, ethyl acetate / water four systems is shown in Figure 4 The camera picture shows that after homogenization for 24 hours, the four emulsion systems can still maintain the emulsion state. The corresponding optical microscope photo shows that the emulsion is a water / alcohol oil emulsion, and the emulsion droplets can stably exist. It shows that the ammonium exchanged MWW zeolite molecular sieve has good emulsification performance on the immiscible system composed of different oil phases and water phases.

[0075] Test Example 2

[0076] The acid treated MWW zeolite molecular sieve obtained in Example 3 was subjected to X-ray diffraction analysis, and its structure was observed by electron microscopy. The ammonium exchanged molecular sieve material was used in the emulsification process and observed by optical microscopy. The emulsification process steps are as follows:

[0077] The 3 mL deionized water and 20 mg of the acid treated zeolite molecular sieve powder were mixed with 3 mL of the oil (cyclohexane / dodecane) in a 10 mL glass bottle. The mixture was ultrasonically treated for 10 minutes, and then homogenized to generate a stable Pickering emulsion. After standing for 24 hours, a photo was taken and optical microscopy was performed.

[0078] The results are shown in Figure 5As shown, XRD results show that the commercial MWW zeolite molecular sieve has good crystallinity, and the electron microscope photos show that the zeolite molecular sieve sample has obvious lamellar morphology. When applied in the cyclohexane / water and dodecane / water emulsion system, after 24 hours of standing, the camera photos show that it still maintains good emulsion state. The corresponding light microscope photos show that it is an oil-in-water emulsion, and the emulsion droplets remain stable. It is shown that the commercial lamellar MWW zeolite molecular sieve after ammonium exchange treatment also has good emulsification performance.

[0079] Test Example 3

[0080] The hydrothermally synthesized MOR fibrous zeolite molecular sieve, the ammonium exchanged MOR fibrous zeolite molecular sieve (i.e. the zeolite molecular sieve obtained in Example 4) were subjected to X-ray diffraction analysis, and the structure was observed by electron microscopy. The ammonium exchanged molecular sieve material was used in the emulsification process and observed by light microscopy. The emulsification process steps are as follows:

[0081] 3 mL of deionized water and 20 mg of acid-treated zeolite molecular sieve powder were mixed with 3 mL of oil (cyclohexane) in a 10 mL glass bottle. The mixture was ultrasonically treated for 10 minutes, and then homogenized to generate a stable Pickering emulsion. After standing for 24 hours, a photo was taken and light microscopy was performed.

[0082] As shown in Table 2, XRD results show that the MOR zeolite molecular sieve has good crystallinity, and the electron microscope photos show that it has obvious fibrous morphology. After standing for 24 hours in the cyclohexane / water emulsion system, the camera photos show that it maintains good emulsion state. The light microscope photos show that it is an oil-in-water emulsion, and the emulsion droplets remain stable. It is shown that the acid form MOR fibrous zeolite molecular sieve after ammonium exchange treatment has good emulsification performance. Figure 6

[0083] In addition, ribbon, rod or tube zeolites and the like are fibrous-like morphologies, which are zeolite materials with high aspect ratio characteristics. After acid treatment by the method of Examples 1-2, an acid form zeolite molecular sieve is obtained; the acid treatment is ammonium exchange or liquid acid solution treatment. Then the material is applied to a water / oil emulsion system, and the above emulsification operation is performed, which has emulsification performance, which can be predicted by a person skilled in the art according to scientific research common sense.

[0084] Comparative Example

[0085] ​Traditionally, zeolites and other solid particles with single hydrophilic / oleophilic properties are not considered to be emulsifiable. Therefore, surface modification is required, i.e. grafting by organosilane, surfactant or other additives, to impart the ability of zeolites as emulsifiers. There is no report on the emulsification of zeolite molecular sieve materials without grafting modification due to their poor performance. Therefore, the present application provides a comparison of the emulsification performance of common ZSM-5, LTA, Y, Beta, SAPO-34, SBA-15 molecular sieves.

[0086] XRD analysis, electron microscopy and emulsification of water / oil system results of NaHCO3 treated hydrogen type ZSM-5 zeolite Na-IRZ-MFI001, commercial hydrogen type ZSM-5 zeolite IRZ-MFI001, HNO3 treated hydrogen type ZSM-5 zeolite HNO3-IRZ-MFI001 are shown in Figure 7 XRD analysis, electron microscopy and emulsification of water / oil system results of NaHCO3 treated hydrogen type ZSM-5 zeolite Na-IRZ-MFI001, commercial hydrogen type ZSM-5 zeolite IRZ-MFI001, HNO3 treated hydrogen type ZSM-5 zeolite HNO3-IRZ-MFI001 are shown in Figure 8 XRD analysis, electron microscopy and emulsification of water / oil system results of NaHCO3 treated hydrogen type ZSM-5 zeolite Na-IRZ-MFI001, commercial hydrogen type ZSM-5 zeolite IRZ-MFI001, HNO3 treated hydrogen type ZSM-5 zeolite HNO3-IRZ-MFI001 are shown in Figure 9 XRD analysis, electron microscopy and emulsification of water / oil system results of NaHCO3 treated hydrogen type ZSM-5 zeolite Na-IRZ-MFI001, commercial hydrogen type ZSM-5 zeolite IRZ-MFI001, HNO3 treated hydrogen type ZSM-5 zeolite HNO3-IRZ-MFI001 are shown in Figure 10As shown, XRD proved that the SBA-15 type zeolite molecular sieve was amorphous, and the electron microscope showed that it had strip-shaped morphology. However, the camera photo showed that it did not have emulsifying ability. XRD proved that both SAPO-34 and Beta zeolite molecular sieves had good crystallinity, and the electron microscope photo of the Beta zeolite molecular sieve showed that it had irregular block-shaped morphology, and the electron microscope photo of the SAPO-34 zeolite molecular sieve showed that it had regular cubic morphology. After homogenization of the cyclohexane / water emulsion system, the Beta zeolite molecular sieve dispersed into the water phase, and a small amount of SAPO-34 zeolite molecular sieve dispersed into the oil phase, and no emulsion was formed. In combination with the above results, it can be seen that these existing molecular sieve materials do not have emulsifying performance or have poor emulsifying performance. Figures 7 to 10 As can be seen from the comparison of the results of Test Examples 1-3, these existing molecular sieve materials do not have emulsifying performance or have poor emulsifying performance.

Claims

1. The application of ungrafted acidic zeolite molecular sieves in Pickering emulsification or in the preparation of Pickering emulsifiers, characterized in that, The ungrafted acidic zeolite molecular sieve is obtained by treating zeolite with lamellar, fibrous, linear, ribbon-like, rod-like, or tubular particle morphologies with ammonium exchange or liquid acid solution. The ammonium exchange step includes mixing zeolite with an ammonium ion-containing solution for ammonium exchange, reflux, and calcination to obtain the ungrafted acidic zeolite molecular sieve. The liquid acid solution treatment step includes mixing zeolite with liquid acid, heating and reacting, and after the reaction is completed, washing, drying and calcining to obtain acidic zeolite molecular sieves without grafting modification.

2. The application according to claim 1, characterized in that, The zeolite particles have a lamellar or fibrous morphology.

3. The application according to claim 1, characterized in that, The ammonium source for the ammonium exchange is ammonium nitrate, ammonium sulfate, ammonium chloride, or ammonium carbonate.

4. The application according to claim 1, characterized in that, The liquid acid is nitric acid, hydrochloric acid, sulfuric acid, or phosphoric acid.

5. The application according to claim 1, characterized in that, The Pickering emulsification is an emulsification of an immiscible system consisting of a low-polarity oil phase and a high-polarity water / alcohol phase.

6. The application according to claim 5, characterized in that, The low-polarity oil phase is a hydrocarbon, higher alcohol, aldehyde, or ketone.

7. The application according to claim 5, characterized in that, The low-polarity oil phase is cyclohexane, dodecane, toluene, dodecyl aldehyde, or ethyl acetate.

8. The application according to claim 5, characterized in that, The highly polar water / alcohol phase is water or a low-carbon alcohol.

9. The application according to claim 8, characterized in that, The lower alcohol is ethylene glycol.

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