Preparation method of lignin nanobottle

Abstract

The present invention belongs to the field of nanomaterial preparation, and relates to a method for preparing a lignin nanobottle. It includes: mixing γ-butyrolactone and water evenly to obtain a γ-butyrolactone solution; dissolving the original lignin component in a γ-butyrolactone solution or γ-butyrolactone, mixing evenly under ultrasonic conditions, filtering to remove insoluble components, and obtaining a lignin γ-butyrolactone solution; dropping the lignin γ-butyrolactone solution into water or a γ-butyrolactone solution, and self-assembling to obtain a lignin nanobottle solution; dialyzing the lignin nanobottle solution, dialyzing away γ-butyrolactone, and obtaining a lignin nanobottle aqueous solution. The present invention uses lignin with a wide range of sources, green, harmless, low cost, and good biocompatibility as a raw material, and adopts a homogeneous nanoprecipitation method to solve the problems of the current nanobottle preparation process being complicated, expensive, the raw materials not being able to achieve complete greenness, and the narrow application range of isotropic lignin nanospheres.

Description

Technical Field

[0001] The invention belongs to the technical field of nano material preparation, relates to the preparation of biomass-based nano materials, and specifically relates to a method for preparing a lignin nano bottle. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Nanobottles have received considerable attention in recent years due to their ability to rapidly load chemical reagents, bioeffectors, therapeutic diagnostics, and nanoscale objects. They have been used in a range of applications related to catalysis, pollutant separation, and drug delivery. In addition, the openings can also be designed with smart blocking features to achieve stimuli-responsive release of the payload.

[0004] At present, the existing nanobottle preparation methods mainly process inorganic or organic polymers in a more complicated way. For example: Shreya Udani et al. (Nature Nanotechnology, 2023) infused polyethylene glycol, acrylic acid, gelatin and oil phase into a three-inlet flow focusing microfluidic device, and prepared nanobottles by oil and water phase separation and photoinitiated polymer polymerization for the secretion and transcription of cell growth factors. However, its preparation method is complicated, and the prepared nanobottles still pose certain hazards to the human body during application. A Chinese patent with the authorization publication number CN 106392096 B discloses a method for preparing a gold nanobottle. However, this method uses gold to prepare nanobottles, the process is complicated, the cost is very high, and the scope of application is not wide. Zhang et al. (Journal of Colloid and Interface Science, 2003, 467-472) used a hydrothermal method to assemble functional polymer nanospheres with tetraethoxysilane, and prepared silica nanobottles by removing the core through program calcination. The entire preparation process is difficult to control, the preparation selectivity is not high enough, and the degree of greening is low. Therefore, the preparation of nanobottles urgently requires a simpler and more efficient method, while ensuring that the raw materials are green, harmless, and biocompatible.

[0005] Lignin, as a "natural green raw material", is not only widely present in plants, but also the second largest renewable resource in nature after cellulose. Lignin itself is green and harmless, has good biocompatibility and low cost, which makes it highly efficient in various fields. In recent years, researchers are keen to convert low-quality lignin raw components into lignin nanomaterials to improve their high value-added applications. In the preparation method of lignin-based nanomaterials, current patents and research are mainly focused on the preparation of isotropic micro-nanospheres. As for the preparation of lignin nanobottles with anisotropic nanoscale Janus structures, there are currently no patents or research papers publicly reported. Summary of the invention

[0006] In view of the above problems, the present invention provides a method for preparing a lignin nanobottle. The present invention uses lignin, which is widely available, green, harmless, low-cost, and has good biocompatibility, as raw material, and adopts a homogeneous nanoprecipitation method to solve the problems of the current nanobottle preparation process being complicated, expensive, the raw materials not being completely green, and the narrow application range of isotropic lignin nanospheres. Through the preparation of lignin nanobottles, the application of low-quality lignin in cutting-edge fields such as medical engineering, photokinetic anti-tumor diagnosis and treatment, and intelligent drug delivery can be realized.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] The first aspect of the present invention provides a method for preparing a lignin nanobottle, comprising:

[0009] Mixing γ-butyrolactone and water uniformly to obtain a γ-butyrolactone solution;

[0010] The original lignin component is dissolved in a γ-butyrolactone solution or γ-butyrolactone, mixed evenly under ultrasonic conditions, and filtered to remove insoluble components to obtain a lignin γ-butyrolactone solution;

[0011] The lignin γ-butyrolactone solution is added dropwise to water or γ-butyrolactone solution, and the lignin nanobottles are self-assembled under stirring conditions to obtain a lignin nanobottle solution;

[0012] The lignin nanobottle solution is dialyzed to remove the γ-butyrolactone, thereby obtaining a lignin nanobottle aqueous solution.

[0013] The present invention develops a simple and green method to achieve efficient preparation and structural morphology regulation of nanobottles by utilizing harmless, biocompatible and low-cost lignin, which is not only of great significance for further expanding the utilization of nanobottles, but also broadens the utilization space of lignin.

[0014] In some embodiments, the lignin component is alkali lignin or kraft lignin;

[0015] In some embodiments, the preparation method of the lignin raw component is as follows: adjust the pH of industrial black liquor to 2-5 with 0.5-4 mol / L sulfuric acid, centrifuge at 2000-10000 rpm, pour off the supernatant, and dry the precipitate to obtain.

[0016] In some embodiments, in the γ-butyrolactone solution, the volume ratio of γ-butyrolactone to water is 1-9:9-1.

[0017] In some embodiments, the concentration of lignin in the lignin γ-butyrolactone solution is 2-50 mg / ml.

[0018] In some embodiments, the filtration uses a microporous filter membrane;

[0019] In some embodiments, the pore size of the filter membrane is 0.22 μm or 0.45 μm.

[0020] In some embodiments, during the self-assembly process, the volume ratio of the lignin γ-butyrolactone solution to the water / γ-butyrolactone solution is 1-2:8.

[0021] In some embodiments, during the self-assembly process, the stirring rate is 50-800 rpm / min.

[0022] In some embodiments, the molecular weight of the dialysis bag is 200-2000 Da, and the dialysis time is 24-96 h.

[0023] The second aspect of the present invention provides a lignin nanobottle prepared by the above method, wherein the diameter of the nanobottle body can be adjusted within the range of 50-400 nm, and the size of the bottle mouth can be adjusted within the range of 10-200 nm.

[0024] The third aspect of the present invention provides the use of the above method in preparing lignin micron bottles.

[0025] Beneficial effects of the present invention

[0026] (1) The lignin raw component used in the present invention is obtained by acid precipitation of low-quality liquid rich in lignin from a pulping plant, thereby realizing resource utilization and high-value utilization of low-quality products.

[0027] (2) The morphology, size and opening size of the lignin nanobottle prepared by the present invention can be controlled.

[0028] (3) The preparation method of the lignin nanobottle of the present invention is simple, convenient and efficient, and the solvent used is green.

[0029] (4) The present invention uses a lignin nanobottle with good biocompatibility to broaden the application scope of lignin, making it have application potential in high-end application fields such as bioengineering and drug carriers. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the exemplary embodiments of the present invention and their description are used to explain the present invention and do not constitute improper limitations on the present invention.

[0031] Figure 1 This is the SEM morphology of the lignin nanobottle obtained in Example 2.

[0032] Figure 2 This is the TEM morphology of the lignin nanobottle obtained in Example 4.

[0033] Figure 3 This is the SEM morphology of the lignin nanobottle obtained in Example 7.

[0034] Figure 4 This is the TEM morphology of the lignin nanobottle obtained in Example 8.

[0035] Figure 5 This is the SEM morphology of the lignin nanobottle obtained in Example 10.

[0036] Figure 6 This is the infrared spectrum of the lignin nanobottle obtained in Example 2. DETAILED DESCRIPTION

[0037] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0038] The present invention will be further described in detail below in conjunction with specific embodiments. It should be noted that the specific embodiments are intended to explain the present invention rather than to limit it.

[0039] Example 1

[0040] First, γ-butyrolactone and water were mixed in a volume ratio of 5:1 to form a γ-butyrolactone solution. Then, the original lignin component was added to the γ-butyrolactone solution to prepare a 2mg / ml lignin γ-butyrolactone solution, and the lignin was fully dissolved by ultrasonication for 10 minutes, and then the insoluble components were filtered out with a microfiltration membrane. Then, 2ml of the lignin γ-butyrolactone solution was added dropwise to 8ml of deionized water, and the dropwise addition speed was controlled at 1mg / ml. The mixture was stirred at 50r / min for 0.5h to obtain a lignin nanobottle solution. The lignin nanobottle solution was transferred to a dialysis bag (1000Da) and dialyzed in deionized water for 96h to replace the γ-butyrolactone and obtain a lignin nanobottle aqueous solution. The γ-butyrolactone aqueous solution outside the dialysis bag was evaporated to obtain crude γ-butyrolactone, which can be used further.

[0041] Example 2

[0042] First, γ-butyrolactone and water were mixed in a volume ratio of 5:1 to form a γ-butyrolactone solution. Then, the original lignin component was added to the γ-butyrolactone solution to prepare a 10mg / ml lignin γ-butyrolactone solution, and the lignin was fully dissolved by ultrasonication for 10 minutes, and then the insoluble components were filtered out with a microfiltration membrane. Then 2ml of the lignin γ-butyrolactone solution was added dropwise to 8ml of deionized water, and the dropwise addition speed was controlled at 1mg / ml. The mixture was stirred at 50r / min for 0.5h to obtain a lignin nanobottle solution. The lignin nanobottle solution was transferred to a dialysis bag (1000Da) and dialyzed in deionized water for 24h to replace the γ-butyrolactone to obtain a lignin nanobottle aqueous solution. The γ-butyrolactone aqueous solution outside the dialysis bag was evaporated to obtain crude γ-butyrolactone, which can be used further.

[0043] Example 3

[0044] First, γ-butyrolactone and water were mixed in a volume ratio of 9:1 to form a γ-butyrolactone solution. Then, the original lignin component was added to the γ-butyrolactone solution to prepare a 10mg / ml lignin γ-butyrolactone solution, and the lignin was fully dissolved by ultrasonication for 10 minutes, and then the insoluble components were filtered out with a microfiltration membrane. Then 2ml of the lignin γ-butyrolactone solution was added dropwise to 8ml of deionized water, and the dropwise addition speed was controlled at 1mg / ml. The mixture was stirred at 50r / min for 0.5h to obtain a lignin nanobottle solution. The lignin nanobottle solution was transferred to a dialysis bag (1000Da) and dialyzed in deionized water for 96h to replace the γ-butyrolactone to obtain a lignin nanobottle aqueous solution. The γ-butyrolactone aqueous solution outside the dialysis bag was evaporated to obtain crude γ-butyrolactone, which can be used further.

[0045] Example 4

[0046] First, γ-butyrolactone and water were mixed in a volume ratio of 9:1 to form a γ-butyrolactone solution. Then, the original lignin component was added to the γ-butyrolactone solution to prepare a 10mg / ml lignin γ-butyrolactone solution, and the lignin was fully dissolved by ultrasonication for 10 minutes, and then the insoluble components were filtered out with a microfiltration membrane. Then 2ml of the lignin γ-butyrolactone solution was added dropwise to 8ml of deionized water, and the dropwise addition speed was controlled at 1mg / ml. The mixture was stirred at 200r / min for 0.5h to obtain a lignin nanobottle solution. The lignin nanobottle solution was transferred to a dialysis bag (2000Da) and dialyzed in deionized water for 96h to replace the γ-butyrolactone to obtain a lignin nanobottle aqueous solution. The γ-butyrolactone aqueous solution outside the dialysis bag was evaporated to obtain crude γ-butyrolactone, which can be used further.

[0047] Example 5

[0048] First, γ-butyrolactone and water were mixed in a volume ratio of 9:1 to form a γ-butyrolactone solution. Then, the original lignin component was added to the γ-butyrolactone solution to prepare a 20mg / ml lignin γ-butyrolactone solution, and the lignin was fully dissolved by ultrasonication for 10 minutes, and then the insoluble components were filtered out with a microfiltration membrane. Then 2ml of the lignin γ-butyrolactone solution was added dropwise to 8ml of deionized water, and the dropwise addition speed was controlled at 1mg / ml. The mixture was stirred at 50r / min for 0.5h to obtain a lignin nanobottle solution. The lignin nanobottle solution was transferred to a dialysis bag (200Da) and dialyzed in deionized water for 96h to replace the γ-butyrolactone to obtain a lignin nanobottle aqueous solution. The γ-butyrolactone aqueous solution outside the dialysis bag was evaporated to obtain crude γ-butyrolactone, which can be used further.

[0049] Example 6

[0050] First, 4 ml of γ-butyrolactone was mixed with 20 ml of water to obtain a γ-butyrolactone solution. 50 mg of sulfate lignin was dissolved in 1 ml of γ-butyrolactone to obtain a 50 mg / ml lignin γ-butyrolactone solution. Then, 1 ml of the lignin γ-butyrolactone solution was added to 8 ml of the γ-butyrolactone solution at a uniform speed of 1 ml / min, and the stirring speed was 800 r / min to obtain a lignin nanobottle solution. The lignin nanobottle solution was transferred to a dialysis bag (1000 Da) and dialyzed in deionized water for 96 hours to replace the γ-butyrolactone to obtain a lignin nanobottle aqueous solution. The γ-butyrolactone aqueous solution outside the dialysis bag was evaporated to obtain crude γ-butyrolactone, which can be used further.

[0051] Example 7

[0052] First, 4 ml of γ-butyrolactone was mixed with 6 ml of water to obtain a γ-butyrolactone solution. 50 mg of alkali lignin was dissolved in 1 ml of γ-butyrolactone to obtain a 50 mg / ml lignin γ-butyrolactone solution. Then, 1 ml of the lignin γ-butyrolactone solution was added to 8 ml of the γ-butyrolactone solution at a uniform speed of 1 ml / min, and the stirring speed was 800 r / min to obtain a lignin nanobottle solution. The lignin nanobottle solution was transferred to a dialysis bag (1000 Da) and dialyzed in deionized water for 96 hours to replace the γ-butyrolactone to obtain a lignin nanobottle aqueous solution. The γ-butyrolactone aqueous solution outside the dialysis bag was evaporated to obtain crude γ-butyrolactone, which can be used further.

[0053] Example 8

[0054] First, 4 ml of γ-butyrolactone was mixed with 6 ml of water to obtain a γ-butyrolactone solution. 10 mg of alkali lignin was dissolved in 1 ml of γ-butyrolactone to obtain a 10 mg / ml lignin γ-butyrolactone solution. Then, 1 ml of the lignin γ-butyrolactone solution was added to 8 ml of the γ-butyrolactone solution at a uniform speed of 1 ml / min, and the stirring speed was 800 r / min to obtain a lignin nanobottle solution. The lignin nanobottle solution was transferred to a dialysis bag (1000 Da) and dialyzed in deionized water for 96 hours to replace the γ-butyrolactone to obtain a lignin nanobottle aqueous solution. The γ-butyrolactone aqueous solution outside the dialysis bag was evaporated to obtain crude γ-butyrolactone, which can be used further.

[0055] Example 9

[0056] First, 4 ml of γ-butyrolactone was mixed with 20 ml of water to obtain a γ-butyrolactone solution. 50 mg of alkali lignin was dissolved in 5 ml of γ-butyrolactone to obtain a 50 mg / ml lignin γ-butyrolactone solution. Then, 5 ml of the lignin γ-butyrolactone solution was added to 8 ml of the γ-butyrolactone solution at a uniform speed of 1 ml / min, and the stirring speed was 800 r / min to obtain a lignin nanobottle solution. The lignin nanobottle solution was transferred to a dialysis bag (1000 Da) and dialyzed in deionized water for 96 hours to replace the γ-butyrolactone to obtain a lignin nanobottle aqueous solution. The γ-butyrolactone aqueous solution outside the dialysis bag was evaporated to obtain crude γ-butyrolactone, which can be used further.

[0057] Example 10

[0058] First, 4 ml of crude γ-butyrolactone was mixed with 6 ml of water to obtain a γ-butyrolactone solution. 50 mg of alkali lignin was dissolved in 1 ml of γ-butyrolactone to obtain a 50 mg / ml lignin crude γ-butyrolactone solution. Then, 1 ml of the lignin γ-butyrolactone solution was added to 8 ml of the γ-butyrolactone solution at a uniform speed of 1 ml / min, and the stirring speed was 800 r / min to obtain a lignin nanobottle solution. The lignin nanobottle solution was transferred to a dialysis bag (1000 Da) and dialyzed in deionized water for 96 hours to replace the crude γ-butyrolactone to obtain a lignin nanobottle aqueous solution.

[0059] The particle size and pore size of the nanobottles prepared in Examples 1 to 10 were tested, and the results are shown in Table 1.

[0060] Table 1: Particle size and pore size of nanobottles obtained in all examples

[0061]

[0062] From Table 1 and Figure 1-Figure 6 It can be seen that the morphology, size and opening size of the lignin nanobottle prepared by the present invention can be controlled.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a lignin nanobottle, characterized in that: include: Method one is, Mixing γ-butyrolactone and water uniformly to obtain a γ-butyrolactone solution; The original lignin component is dissolved in the γ-butyrolactone solution, mixed evenly under ultrasonic conditions, and filtered to remove insoluble components to obtain a lignin γ-butyrolactone solution; The lignin γ-butyrolactone solution is added dropwise into water, and the lignin nanobottles are self-assembled under stirring conditions to obtain a lignin nanobottle solution; The lignin nanobottle solution is dialyzed to remove the γ-butyrolactone, thereby obtaining a lignin nanobottle aqueous solution; During the self-assembly process, the volume ratio of the lignin γ-butyrolactone solution to water is 1:4; In the γ-butyrolactone solution, the volume ratio of γ-butyrolactone to water is 5-9:1; In the lignin γ-butyrolactone solution, the concentration of lignin is 2-50 mg / ml; During the self-assembly process, the stirring rate is 50-800 rpm / min; Or, method 2 is, Mixing γ-butyrolactone and water uniformly to obtain a γ-butyrolactone solution; The original lignin component is dissolved in γ-butyrolactone, mixed evenly under ultrasonic conditions, and filtered to remove insoluble components to obtain a lignin γ-butyrolactone solution; The lignin γ-butyrolactone solution is added dropwise to the γ-butyrolactone solution, and the lignin nanobottles are self-assembled under stirring conditions to obtain a lignin nanobottle solution; The lignin nanobottle solution is dialyzed to remove the γ-butyrolactone, thereby obtaining a lignin nanobottle aqueous solution; During the self-assembly process, the volume ratio of the lignin γ-butyrolactone solution to the γ-butyrolactone solution is 1:8; In the γ-butyrolactone solution, the volume ratio of γ-butyrolactone to water is 1:1.5-5; In the lignin γ-butyrolactone solution, the concentration of lignin is 2-50 mg / ml; During the self-assembly process, the stirring rate is 50-800 rpm / min.

2. The method for preparing the lignin nanobottle according to claim 1, characterized in that: The lignin raw component is alkali lignin or kraft lignin; Alternatively, the preparation method of the original lignin component is as follows: the pH of the industrial black liquor is adjusted to 2-5 with 0.5-4 mol / L sulfuric acid, centrifuged at 2000-10000 rpm, the supernatant is discarded, and the precipitate is dried to obtain the product.

3. The method for preparing the lignin nanobottle according to claim 1, characterized in that: The filtration adopts a microporous filter membrane; the pore size of the filter membrane is 0.22 μm or 0.45 μm.

4. The method for preparing the lignin nanobottle according to claim 1, characterized in that: The molecular weight of the dialysis bag is 200-2000 Da, and the dialysis time is 24-96 h.

5. The lignin nanobottle prepared by the method according to any one of claims 1 to 4, characterized in that: The diameter of the nanobottle can be adjusted between 50-400 nm, and the size of the bottle mouth can be adjusted between 10-200 nm.

Images