Konjac glucomannan ultrafiltration membrane, preparation method and application thereof

Abstract

The present application relates to the technical field of daily chemicals, and provides konjac glucomannan ultrafiltration membrane and a preparation method and application thereof, which comprises the following steps: preparing konjac glucomannan sol; preparing amphiphilic modified konjac glucomannan; preparing konjac glucomannan spinning emulsion gel; and preparing konjac glucomannan ultrafiltration membrane. The present application utilizes the physical entanglement of konjac glucomannan molecular chains and PVA molecular chains to form a gel network structure with higher stability, simultaneously utilizes the surface activity of amphiphilic konjac glucomannan to obtain a stable emulsion, and prepares biodegradable konjac glucomannan laundry condensation bead membrane with high utilization degree through microfluidic air jet spinning technology. The raw material is low in price and widely available, and has the advantages of convenient material selection, low cost, good antibacterial property, non-toxicity and harmlessness, biodegradability, and good bioavailability. The microfluidic air jet spinning method is simple in preparation process and high in stability, and can be realized only by using a machine at room temperature, and the obtained fiber membrane is more stable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of daily chemicals, in particular to konjac glucomannan ultrafiltration membrane and its preparation method and application. BACKGROUND

[0002] Laundry condensation beads, also known as laundry beads, are an innovative laundry product named laundry condensation beads due to their bead-like appearance. Laundry condensation beads are mainly composed of two parts, one part is traditional laundry liquid, and the other part is an outer layer of water-soluble film. The design of water-soluble film material is the key to the quality of laundry condensation beads, and the formed film needs to have the characteristics of pressure resistance, moisture resistance, good water solubility, etc. At present, polyvinyl alcohol (PVA) is the most common main material used to prepare laundry condensation bead film, although it has good film-forming property, but still needs to add surfactants, stabilizers and other ingredients in the formula to realize performance stability.

[0003] For example, Chinese patent 202110706810.9, named a bacteriostatic and demite laundry condensation bead and its preparation method, introduces a bacteriostatic and demite laundry condensation bead and its preparation method. The invention mainly improves the cleaning liquid in the laundry condensation bead, by adding polyacrylamide as a stabilizer for silver ion antibacterial agent, and using specific non-ionic surfactant and anionic surfactant complex, the obtained laundry condensation bead has excellent antibacterial stability and extremely high decontamination power. But its condensation bead film still uses traditional PVA film, which is easy to break and not completely water-soluble.

[0004] For example, Chinese patent 201711189404.X, named a stain-proof laundry condensation bead and its preparation method, introduces a stain-proof laundry condensation bead and its preparation method, which is made of detergent and water-soluble film containing detergent, the water-soluble film includes an inner layer in direct contact with the detergent, a middle solubilizing layer and an outer disintegrating layer, each layer is compounded by hot pressing. The water-soluble film used in the laundry condensation bead of the invention has the performance of rapid water-solubility, cracking and dispersion, which can avoid the staining phenomenon occurring during use. But its structure is too complex, the production cost is high and affects the dissolution of the content in the washing process.

[0005] For example, Chinese patent 2020103970414, named a plastic packaging film for laundry condensation bead production and its preparation method and application, introduces a plastic packaging film for laundry condensation bead production, which is composed of polyvinyl alcohol / methyl acrylate-ethylene copolymer, ionic polymer, modified metallocene polyethylene, antistatic agent, etc. The plastic packaging film for laundry condensation bead production solves the technical problem of incomplete water-solubility of the existing laundry condensation bead heat-sealed PVA film, and the appearance of strip-shaped PVA. But its composition is too complex, and a large amount of synthetic polymer materials are used, which has certain safety hazards and environmental problems.

[0006] With the development of science and technology, the continuous improvement of the quality of life, people have higher requirements for laundry cleaning products. In order to meet the needs of the people, it is urgent to provide a product with further effect than the existing water-soluble film to improve the quality of laundry beads. SUMMARY

[0007] In order to achieve the above purpose, the present application provides the following technical solutions:

[0008] The present application provides a preparation method of konjac glucomannan ultrafiltration membrane, which comprises the following steps:

[0009] (1) Preparation of konjac glucomannan sol: take 10-20 parts of konjac glucomannan, add 300-500 parts of deionized water, stir and dissolve to prepare konjac glucomannan sol;

[0010] (2) Preparation of amphiphilic modified konjac glucomannan: take 80-240 parts of konjac glucomannan sol, add NaOH solution to prevent konjac glucomannan molecules from deacetylation, adjust the solution to pH 8-10, then add 3-9 parts of bromohexadecane solution, and stir under the action of magnetic force by ultra-high pressure microjet homogenizer at 40℃, cycle 3-5 times; wash with water several times to remove sodium salt, and prepare amphiphilic modified konjac glucomannan;

[0011] (3) Preparation of konjac glucomannan spinning emulsion gel: take 3-5 parts of PVA as external liquid; take 3-5 parts of amphiphilic modified konjac glucomannan and add it to 3-5 parts of konjac glucomannan sol to obtain a mixed solution as internal liquid; under the conditions of humidity 75RH and temperature 25℃, use 3 injection pumps to inject the internal liquid and external liquid into the microchannel of the microfluidic device, and the konjac glucomannan spinning emulsion gel is prepared;

[0012] (4) Preparation of konjac glucomannan ultrafiltration membrane: take 5-15 parts of konjac glucomannan spinning emulsion gel with a syringe, prepare nanofiber membrane under the conditions of air pressure 0.1 MPa and temperature 40-50℃ by using microfluidic gas spraying spinning equipment, and dry the prepared nanofiber membrane in a vacuum drying box for 4-6h to obtain konjac glucomannan ultrafiltration membrane.

[0013] Further, the ultra-high pressure of the ultra-high pressure microjet homogenizer in step (2) is 100-150 MPa.

[0014] Further, in step (3), the injection speed of the external liquid is 1-5 ml / h, and the injection speed of the internal liquid is 0.1-0.5 ml / h.

[0015] Further, in step (3), the injection tube of the microfluidic device is assembled by bonding glass capillary tube on a glass slide.

[0016] Further, the outer diameter of the glass capillary is 960 mu m.

[0017] Further, in step (4), the microfluidic air jet spinning device comprises a needle (a nozzle), the distance between the needle (the nozzle) and the microfluidic air jet spinning device is 25 cm, the push injection speed is 9 ml / h, and the needle (the nozzle) adopts a 19G+13G model.

[0018] Further, in step (4), the diameter of the prepared nanofiber is between 120-140 nm, and the area is 100-200 mm 2 .

[0019] Further, in step (4), the microfluidic air jet spinning device adopts a drum mode to circularly prepare nanofiber membranes.

[0020] The application provides a konjac glucomannan ultrafiltration membrane, which is prepared by the preparation method.

[0021] The konjac glucomannan ultrafiltration membrane is applied to the encapsulation of cleaning liquid in laundry beads.

[0022] The konjac glucomannan is low in price and wide in source, the konjac glucomannan can improve the film-forming property and stability of laundry beads membranes, and has good hydrophilicity; the hydrophobically modified konjac glucomannan is a substance that is both hydrophilic and oleophilic, and has good interfacial stability, and the two substances have excellent gel properties and good film-forming property, so that the laundry beads membranes prepared by the two substances can be waterproof and moisture-proof in air and have good water solubility in water; the microfluidic air jet spinning method is a new technology for preparing micro-nanofibers, and the fiber membranes obtained by the technology have higher mechanical properties. Therefore, the laundry beads membranes based on the konjac glucomannan prepared by the microfluidic air jet spinning technology further improve the quality of laundry beads.

[0023] The application has the following beneficial effects:

[0024] (1) The application utilizes the physical entanglement of konjac glucomannan molecular chains and PVA molecular chains to form a gel network structure with higher stability, simultaneously utilizes the surface activity of amphiphilic konjac glucomannan to obtain a stable emulsion, and prepares biodegradable and high-usage konjac glucomannan laundry beads membranes by a microfluidic air jet spinning technology;

[0025] (2) The raw material konjac glucomannan of the application is low in price and wide in source, and has the advantages of convenient material selection, low cost, good antibacterial property, non-toxicity, harmlessness, biodegradability and good bioavailability;

[0026] (3) The microfluidic air-jet spinning method adopted by the application has simple preparation process and high stability, can be realized only by mechanical force and at normal temperature, and the obtained fiber membrane is more stable;

[0027] (4) The amphiphilic konjac glucomannan obtained by chemical modification is a natural green surfactant, and the nanoemulsion is embedded in the fiber, further improving the cleaning activity of the encapsulated laundry condensation beads;

[0028] (5) The application is prepared under alkaline conditions, and can be quickly released in neutral water and completely release the laundry liquid from the konjac glucomannan ultrafiltration membrane. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a preparation flow chart of the ultrafiltration membrane of the application. DETAILED DESCRIPTION

[0030] The specific embodiments of the application will be described in detail below with reference to the accompanying drawings, it should be pointed out that the embodiments are only specific elaboration of the application, and should not be regarded as limitation of the application, the purpose of the embodiments is to enable those skilled in the art to better understand and reproduce the technical scheme of the application, the protection scope of the application should still be limited by the scope defined in the claims.

[0031] As shown in Figure 1 , the application provides a preparation method of konjac glucomannan ultrafiltration membrane, the preparation method comprises:

[0032] S1, preparing konjac glucomannan sol: taking 10-20 parts of konjac glucomannan, adding 300-500 parts of deionized water, stirring and dissolving to prepare konjac glucomannan sol;

[0033] S2, preparing amphiphilic modified konjac glucomannan: taking 80-240 parts of konjac glucomannan sol, adding NaOH solution to prevent konjac glucomannan molecules from deacetylation, adjusting the solution to pH 8-10, then adding 3-9 parts of bromohexadecane solution, stirring under the action of 100-150 MPa ultra-high pressure of an ultra-high pressure microjet homogenizer at 40 DEG C, and circulating 3-5 times; washing with water for several times to remove sodium salt, and preparing amphiphilic modified konjac glucomannan;

[0034] S3, preparing konjac glucomannan spinning emulsion gel: taking 3-5 parts of PVA as external liquid; taking 3-5 parts of amphiphilic modified konjac glucomannan and adding it to 3-5 parts of konjac glucomannan sol, the obtained mixed solution is used as internal liquid; under the conditions of humidity 75RH and temperature 25℃, using 3 injection pumps to inject the internal liquid and the external liquid into the microchannel of the microfluidic device, the injection speed of the external liquid is 1-5ml / h, and the injection speed of the internal liquid is 0.1-0.5ml / h; the konjac glucomannan spinning emulsion gel is prepared; the injection tube of the microfluidic device is assembled by glass capillary tube adhered on a glass slide. The outer diameter of the glass capillary tube is 960μm.

[0035] S4, preparing konjac glucomannan ultrafiltration membrane: using a syringe to take 5-15 parts of konjac glucomannan spinning emulsion gel, under the conditions of air pressure 0.1MPa and temperature 40-50℃, using a microfluidic gas jet spinning device to prepare nanofibers with a diameter of 120-140nm and an area of 100-200mm 2 , placing the prepared nanofiber membrane in a vacuum drying box for drying for 4-6h, and obtaining the konjac glucomannan ultrafiltration membrane. The microfluidic gas jet spinning device includes a needle (jet), the distance between the needle (jet) and the microfluidic gas jet spinning device is 25cm, the injection speed is 9ml / h, and the needle (jet) is a 19G+13G type.

[0036] Example 1

[0037] The embodiment provides a preparation method of a konjac glucomannan ultrafiltration membrane, including the following steps:

[0038] S1, preparing konjac glucomannan sol: taking 20 parts of konjac glucomannan and adding 500 parts of deionized water, stirring and dissolving to prepare konjac glucomannan sol;

[0039] S2, preparing amphiphilic modified konjac glucomannan: taking 80 parts of konjac glucomannan sol, adding NaOH solution to prevent konjac glucomannan molecules from deacetylation, adjusting the solution to pH 8.5, and then adding 3 parts of bromohexadecane solution, and under the condition of 40℃, using an ultrahigh pressure microjet homogenizer to magnetically stir, under the action of an ultrahigh pressure of 150MPa, and circulating 5 times; washing with water for multiple times to remove sodium salt, and preparing amphiphilic modified konjac glucomannan;

[0040] S3, preparing konjac glucomannan spinning emulsion gel: taking 5 parts of PVA as external liquid; taking 3 parts of amphiphilic modified konjac glucomannan and adding it to 3 parts of konjac glucomannan sol, the obtained mixed solution is used as internal liquid; under the conditions of humidity 75RH and temperature 25℃, using 3 injection pumps to inject the internal liquid and the external liquid into the microchannel of the microfluidic device, the injection speed of the external liquid is 2ml / h, and the injection speed of the internal liquid is 0.3ml / h;

[0041] The instant konjac glucomannan spinnable emulsion gel is prepared; the injection tube of the microfluidic device is assembled by bonding a glass capillary tube on a glass slide. The outer diameter of the glass capillary tube is 960 μm.

[0042] S4, preparation of konjac glucomannan ultrafiltration membrane: 15 parts of konjac glucomannan spinnable emulsion gel are taken, and a nanofiber membrane with a diameter of 140 nm and an area of 200 mm 2 The prepared nanofiber membrane is dried in a vacuum drying box for 6 h to obtain a konjac glucomannan ultrafiltration membrane. The microfluidic gas jet spinning device comprises a needle (jet), the distance from the needle (jet) to the microfluidic gas jet spinning device is 25 cm, the injection speed is 9 ml / h, and the needle (jet) adopts a 19G+13G model.

[0043] Example 2

[0044] A method for preparing a konjac glucomannan ultrafiltration membrane, comprising the following steps:

[0045] (1) Preparation of konjac glucomannan sol: 15 parts of konjac glucomannan are taken, 400 parts of deionized water are added, and stirring and dissolution are performed to prepare a konjac glucomannan sol;

[0046] (2) Preparation of amphiphilic modified konjac glucomannan: an ultrahigh pressure microjet homogenizer device is used to prepare the amphiphilic modified konjac glucomannan. First, 160 parts of konjac glucomannan sol are taken, NaOH solution is added to prevent konjac glucomannan molecules from being deacetylated, and the solution is adjusted to pH 8. Second, 6 parts of bromohexadecane solution are added, and magnetic stirring is performed at 40°C to obtain a mixed solution. The mixed solution is subjected to 3 cycles of ultrahigh pressure of 120 MPa by an ultrahigh pressure microjet homogenizer. Then, the solution is washed with water multiple times to remove sodium salt to prepare the amphiphilic modified konjac glucomannan;

[0047] (3) Preparation of laundry bead membrane spinnable emulsion gel: a microfluidic device is assembled by bonding a glass capillary tube on a glass slide. Three cylindrical capillary tubes with an outer diameter of 960 μm are usually selected as injection tubes. 4 parts of PVA are taken as an external liquid; 4 parts of amphiphilic modified konjac glucomannan are added to 4 parts of konjac glucomannan sol to obtain a mixed solution as an internal liquid; three injection pumps are used to inject the fluids into the microchannel at appropriate flow rates. The droplet microfluidic parameters are as follows: humidity 75 RH, temperature 25°C, injection speed of external liquid 1 ml / h, and injection speed of internal liquid 0.1 ml / h. The instant laundry bead membrane spinnable emulsion gel is prepared;

[0048] (4) Preparation of konjac glucomannan laundry bead film: take 10 parts of sol of step (2) with a syringe, and prepare a konjac glucomannan laundry bead film with a microfluidic air jet spinning device; the spinning parameters are as follows: air pressure 0.1 MPa, receiving distance (distance from the needle to the microfluidic air jet spinning device) 25 cm, injection speed 9 ml / h, temperature 45°C, and needle 19G+13G type; after fixing the parameters, a membrane with a fiber diameter of 130 nm and an area of 150 mm2 is prepared in a drum mode cycle, and the prepared ultrafiltration membrane is dried in a vacuum drying box for 5 h, thereby obtaining a konjac glucomannan membrane.

[0049] Example 3

[0050] The present embodiment provides a preparation method of a konjac glucomannan ultrafiltration membrane, comprising the following steps:

[0051] (1) Preparation of konjac glucomannan sol: take 20 parts of konjac glucomannan, add 500 parts of deionized water, stir and dissolve to prepare a konjac glucomannan sol;

[0052] (2) Preparation of amphiphilic modified konjac glucomannan: use an ultra-high pressure microjet homogenizer device to prepare the amphiphilic modified konjac glucomannan. First, take 240 parts of konjac glucomannan sol, add NaOH solution to prevent konjac glucomannan molecules from being deacetylated, and adjust the solution to pH 10. Second, add 9 parts of bromohexadecane solution to the obtained solution, and magnetically stir at 40°C to obtain a mixed solution. The mixed solution is subjected to 100 MPa ultra-high pressure for 5 cycles by an ultra-high pressure microjet homogenizer. Then, the solution is washed with water multiple times to remove sodium salt, thereby preparing the amphiphilic modified konjac glucomannan;

[0053] (3) Preparation of laundry bead film spinning emulsion gel: a microfluidic device is assembled by bonding glass capillary tubes on a glass slide. Usually, three cylindrical capillary blood vessels with an outer diameter of 960 μm are selected as injection tubes. Take 5 parts of PVA as an external liquid; take 3 parts of amphiphilic modified konjac glucomannan, and add it to 5 parts of konjac glucomannan sol to obtain a mixed solution as an internal liquid; use three injection pumps to inject the fluids into the microchannel at appropriate flow rates. The microfluidic parameters of the droplets are as follows: humidity 75 RH, temperature 25°C, injection speed of the external liquid 3 ml / h, and injection speed of the internal liquid 0.5 ml / h. Thus, a laundry bead film spinning emulsion gel is prepared;

[0054] (4) Preparation of konjac glucomannan laundry bead film: 15 parts of the sol of step (2) were taken with a syringe, and a konjac glucomannan laundry bead film was prepared using a microfluidic air-jet spinning device; the spinning parameters were as follows: air pressure 0.1 MPa, receiving distance (distance from the needle (jet) to the microfluidic air-jet spinning device) 25 cm, injection speed 9 ml / h, temperature 50°C, and needle type 19G+13G; after fixing the parameters, a drum mode cycle was used to prepare a film with a fiber diameter of 140 nm and an area of 200 mm2; the prepared ultrafiltration membrane was dried in a vacuum drying oven for 6 h to obtain a konjac glucomannan membrane.

[0055] The konjac glucomannan ultrafiltration membranes prepared in Examples 1, 2 and 3 were used for encapsulation of cleaning liquid in laundry beads.

[0056] To verify the performance of the laundry bead film prepared by the present application, the relevant performance was tested and compared with the existing laundry bead film on the market.

[0057] The time for dissolution in neutral and alkaline water was tested, and the test results are shown in Table 1.

[0058] Table 1

[0059]

[0060] As can be seen from Table 1, the laundry bead film prepared by Examples 1, 2 and 3 has a dissolution time of 5 min in neutral water, while the existing PVA film on the market has a dissolution time of 10 min, the laundry bead plastic sealing film has a dissolution time of 6 min, and the laundry bead multi-layer film has a dissolution time of 6 min. It can be clearly seen that the laundry bead film prepared from the konjac glucomannan ultrafiltration membrane can be dissolved and released more quickly in neutral water; the laundry bead films prepared by Examples 1 and 3 and the laundry bead multi-layer film on the market have a dissolution time of 6 min in alkaline water, and the laundry bead film prepared by Example 2 has a dissolution time of 5 min in alkaline water, but the laundry bead films prepared by Examples 1, 2 and 3 have a dissolution time in alkaline water that is significantly shorter than the dissolution speed of the PVA film and the laundry bead plastic sealing film. Therefore, it can be known that the dissolution time of the laundry bead film prepared by the present application in neutral and alkaline water is significantly shortened compared with the existing laundry bead film.

[0061] The water solubility of the product was tested in a low-temperature environment (<5°C), and the test results are shown in Table 2.

[0062] Table 2

[0063]

[0064] As can be seen from Table 2, the konjac glucomannan ultrafiltration membranes prepared by Examples 1, 2 and 3 completely dissolved in 8 min, 9 min and 8 min respectively in a low temperature environment (<5℃), while the existing PVA membrane, laundry bead plastic sealing film and laundry bead multilayer film completely dissolved in 15 min, 9 min and 10 min respectively, and the konjac glucomannan ultrafiltration membranes prepared by the present application have a faster dissolution speed in a low temperature environment.

[0065] Heat resistance test: keep at (40±2)℃ for 24 hours, after recovery to room temperature, compare with the test before, the test results are shown in Table 3.

[0066] Table 3

[0067]

[0068] As can be seen from Table 3, the konjac glucomannan ultrafiltration membranes prepared by Examples 1, 2 and 3 have no obvious change after keeping at (40±2)℃ for 24 hours and recovery to room temperature, and the heat resistance test is qualified.

[0069] Cold resistance test: keep at (-5±2)℃ for 24 hours, after recovery to room temperature, compare with the test before, the test results are shown in Table 4.

[0070] Table 4

[0071]

[0072] As can be seen from Table 4, the konjac glucomannan ultrafiltration membranes prepared by Examples 1, 2 and 3 have no obvious change after keeping at (-5±2)℃ for 24 hours and recovery to room temperature, and the cold resistance test is qualified.

[0073] The overall results of the test of the related properties of the laundry bead film on the market are shown in Table 5.

[0074] Table 5

[0075]

[0076] After the above test and comparison, the laundry bead prepared by the konjac glucomannan ultrafiltration membrane of the present application is better than other laundry bead films on the market in mechanical strength, water solubility, stability and potential market.

[0077] It should be noted that the technical features not described in detail in the present application can be realized by any existing technology.

[0078] While the preferred embodiments of the application have been described, additional variations and modifications can be made to these embodiments by those skilled in the art once they have the benefit of the foregoing description. Therefore, the appended claims are intended to encompass all such variations and modifications as falling within the scope of the application.

Claims

1. A method for preparing a konjac glucomannan ultrafiltration membrane, characterized by, The preparation method comprises: (1) preparing konjac glucomannan sol: taking 10-20 parts of konjac glucomannan, adding 300-500 parts of deionized water, stirring and dissolving to prepare konjac glucomannan sol; (2) preparing amphiphilic modified konjac glucomannan: taking 80-240 parts of konjac glucomannan sol, adding NaOH solution to prevent konjac glucomannan molecules from deacetylation, adjusting the solution to pH 8-10, and then adding 3-9 parts of bromohexadecane solution, stirring under the action of a magnetic stirrer at 40°C, and circulating 3-5 times; washing with water multiple times to remove sodium salt to prepare amphiphilic modified konjac glucomannan; (3) preparing konjac glucomannan spinning emulsion gel: taking 3-5 parts of PVA as an external solution; taking 3-5 parts of amphiphilic modified konjac glucomannan and adding it to 3-5 parts of konjac glucomannan sol to obtain a mixed solution as an internal solution; under the conditions of humidity 75 RH and temperature 25°C, using three injection pumps to inject the internal solution and the external solution into the microchannel of a microfluidic device to prepare konjac glucomannan spinning emulsion gel; (4) preparing konjac glucomannan ultrafiltration membrane: using a syringe to take 5-15 parts of konjac glucomannan spinning emulsion gel, preparing a nanofiber membrane under the conditions of air pressure 0.1 MPa and temperature 40-50°C using a microfluidic gas spraying spinning device, and drying the prepared nanofiber membrane in a vacuum drying box for 4-6 h to obtain konjac glucomannan ultrafiltration membrane.

2. The method for preparing a konjac glucomannan ultrafiltration membrane according to claim 1, characterized in that, In step (2), the ultra-high pressure of the ultra-high pressure microjet homogenizer is 100-150 MPa.

3. The method for preparing a konjac glucomannan ultrafiltration membrane according to claim 1, characterized in that, In step (3), the push injection speed of the external solution is 1-5 ml / h, and the push injection speed of the internal solution is 0.1-0.5 ml / h.

4. The method for preparing a konjac glucomannan ultrafiltration membrane according to claim 1, characterized in that, In step (3), the injection tube of the microfluidic device is assembled by bonding a glass capillary tube on a glass slide.

5. The method for preparing a konjac glucomannan ultrafiltration membrane according to claim 4, characterized in that, The outer diameter of the glass capillary tube is 960 μm.

6. The method for preparing a konjac glucomannan ultrafiltration membrane according to claim 1, characterized in that, In step (4), the microfluidic gas spraying spinning device comprises a needle, the distance from the needle to the microfluidic gas spraying spinning device is 25 cm, the push injection speed is 9 ml / h, and the needle is of 19G+13G type.

7. The method for preparing a konjac glucomannan ultrafiltration membrane according to claim 1, characterized in that, In step (4), the diameter of the prepared nanofiber is between 120-140 nm, and the area is 100-200 mm 2 .

8. The method for preparing a konjac glucomannan ultrafiltration membrane according to claim 1, characterized in that, In step (4), the microfluidic gas spraying spinning device is used in a drum mode to prepare a nanofiber membrane.

9. A konjac glucomannan ultrafiltration membrane, characterized by, The konjac glucomannan ultrafiltration membrane is prepared by the preparation method of any one of claims 1-8.

10. Use of konjac glucomannan ultrafiltration membrane, characterized in that, The konjac glucomannan ultrafiltration membrane of claim 9 is used for encapsulating cleaning liquid in laundry bead.

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