Carbon nanomaterial dispersing agent of nano construction unit biomacromolecule as well as preparation method and application of carbon nanomaterial dispersing agent

Abstract

The invention discloses a carbon nanomaterial dispersing agent of a nano construction unit biomacromolecule and a preparation method and application thereof, the carbon nanomaterial dispersing agent has high charge, hydrophobicity and large length-diameter ratio, has good dispersing capacity on a carbon nanomaterial, and also has high reaction activity and degradability; higher charges form effective electrostatic repulsion to prevent agglomeration of the carbon nanomaterials, and the nano construction unit can enable the dispersing agent to realize high-concentration dispersion of the carbon nanomaterials at lower concentration through a steric hindrance effect; the dispersing agent not only can realize high-concentration dispersion of the carbon nanomaterial in an aqueous solution, but also can keep stable existence in an organic solution, and also enables the carbon nanomaterial to be more easily subjected to cross-linking reaction in subsequent practical application; and meanwhile, the dispersing agent can be used as a high-polarity material to combine the carbon nanomaterial with other materials. Therefore, the method has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon nanomaterials, and more specifically, to a carbon nanomaterial dispersant of a nanostructured unit biomacromolecule, and a preparation method and application thereof. Background Art

[0002] Carbon nanomaterials, including carbon quantum dots, fullerenes, carbon nanotubes, digraphene and other nanomaterials, all have excellent electrical and thermal conductivity, stable chemical properties and good thermal stability, and are widely used in materials chemistry and mechanochemistry. Among them, carbon nanotubes are tubular carbon nanomaterials with graphite crystals, which are divided into single-walled and multi-walled carbon nanotubes; graphene is a sheet-structured material with a thickness of only a single layer of carbon atoms. The p electrons of carbon atoms in the two carbon nanomaterials form a large range of delocalized π bonds. Due to the π-π interaction, they tend to gather closely together, resulting in poor dispersibility of the two carbon nanomaterials in solvents or polymers, and easy precipitation. In particular, their poor stability and difficulty in dispersion in water systems limit the wide application of this material.

[0003] Carbon nanomaterials can be dispersed in specific solvents and directly dispersed by ultrasonic crushing. The most commonly used dispersing solvents are N-methylpyrrolidone (NMP) and N, N-dimethylformamide (DMF), and imidazole-based ionic liquids ILs. Commonly used dispersants for carbon nanomaterials include surfactants such as sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), sodium cholate (SC), polyvinylrolidone (PVP) and sodium deoxycholate (DOC). Surfactant molecules with specific structures are wrapped on the surface of carbon nanomaterials, resulting in an increase in the aggregation energy barrier, while the repulsive force of the same charge on their surface keeps them at a certain distance. In addition to surfactants, biomacromolecules (long-chain polypeptides, enzymes, DNA molecules, and cellulose, etc.) are also commonly used as dispersants for carbon nanomaterials and are the most convenient to obtain. Biomacromolecule polymers are composed of repeated fixed components, and their unique optically active spirals are wrapped around carbon nanomaterials, forming strong intermolecular forces, thereby weakening the strong π-π interaction of carbon nanomaterials and dispersing them in the solvent. However, these dispersants still have many limitations. On the one hand, the amount of dispersant used is relatively large, often reaching several times, dozens of times, or even higher than the mass of graphite; on the other hand, the dispersant has limited ability to disperse carbon nanomaterials. After ultrasonic treatment, the concentration of carbon nanomaterials (graphene, carbon nanotubes) in the obtained dispersion is usually less than 0.5 mg·mL, and the dispersion performance is poor, which greatly limits its application in practice. In addition, the dispersant will generally remain as an ineffective component in the carbon nanomaterial composite material, which has a great impact on the final performance of the material.

[0004] Therefore, designing a new dispersant that can achieve high-concentration and stable dispersion of carbon nanomaterials at low dosages is of great significance for the practical application of carbon nanomaterials. On this basis, through performance design, it has a high charge, a large aspect ratio, and nano and biological characteristics, enabling the dispersant to disperse high-concentration carbon nanomaterials at low concentrations and having biodegradability, thus promoting the industrial development of carbon nanomaterials. Summary of the Invention

[0005] The object of the present invention is to overcome the above-mentioned defects existing in the prior art, and to provide a carbon nanomaterial dispersant of a nano-structuring unit biopolymer with high charge, hydrophobicity, large aspect ratio and degradability, and its preparation method and application. It has good dispersing ability for carbon nanomaterials (graphene, carbon nanotubes), and also has high reactivity and degradability; the high charge forms an effective electrostatic repulsion to prevent the aggregation of carbon nanomaterials, and the nano-structuring unit can achieve high-concentration dispersion of carbon nanomaterials at low concentrations through steric hindrance effects; this dispersant can not only achieve high-concentration dispersion of carbon nanomaterials (graphene, carbon nanotubes) in aqueous solutions, but also remain stably present in organic solutions, making it easier to carry out cross-linking reactions in subsequent practical applications.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] A carbon nanomaterial dispersant of a nano-structuring unit biopolymer, whose chemical structural formula is shown in Formula I:

[0008]

[0009] Optionally, the hydrophobic angle of the carbon nanomaterial dispersant is 115° - 130°.

[0010] Optionally, the diameter of the carbon nanomaterial dispersant is 2 - 4 nm, and the length is 150 - 300 nm.

[0011] Optionally, the zeta potential of the carbon nanomaterial dispersant is -68 - -94 mV.

[0012] Optionally, the viscosity of the carbon nanomaterial dispersant under the condition of a concentration of 0.1% - 0.5% is 0.70 - 4.50 Pa·s.

[0013] The present invention also discloses a preparation method of a carbon nanomaterial dispersant of a nano-structuring unit biopolymer as described above, including the following steps:

[0014] Subject the ramie stalk powder to alternate cooking, the number of times of the alternate cooking is 2 - 3 times, and each step of the alternate cooking is:

[0015] (1) Mix ramie stalk powder, NaOH, and sodium chlorite, then carry out cooking at 60 - 80 °C for 1 - 2 h, and subsequently perform ball milling for 30 - 75 min to obtain biological macromolecules;

[0016] (2) Mix the biological macromolecules with acidic pectin lyase (Cangzhou Xiasheng Enzyme Biotechnology Co., Ltd., acidic pectin lyase, initial enzyme activity 170 U / mL), glacial acetic acid, and glycerol, then carry out cooking at 50 - 70 °C for 1 - 2 h, and subsequently perform ball milling for 20 - 30 min to obtain the carbon nanomaterial dispersant.

[0017] Optionally, in step (1), the particle size of the ramie stalk powder is 100 mesh; the mass concentration of NaOH is 4 - 10%; the mass concentration of sodium chlorite is 1 - 3%; the bath ratio of the ramie stalk powder to NaOH and sodium chlorite solution is 1:8.

[0018] Optionally, in step (2), the mass concentration of the acidic pectin lyase is 1 - 4%; the mass concentration of glacial acetic acid is 0.2 - 0.6%; the mass concentration of glycerol is 0.1 - 0.3%; the bath ratio of the biological macromolecules to acidic pectin lyase, glacial acetic acid, and glycerol solution is 1:8.

[0019] The present invention also discloses the application of the carbon nanomaterial dispersant of the above - mentioned nano - building unit biological macromolecules in the preparation of a carbon nanomaterial dispersion liquid, including the following steps:

[0020] Add carbon nanomaterials to an organic solvent, and under the action of 0.1% - 0.5% of the carbon nanomaterial dispersant, disperse by ultrasonic treatment to achieve the dispersion of high - concentration carbon nanomaterials in the organic solvent, thereby obtaining a carbon nanomaterial dispersion liquid.

[0021] Optionally, the time of ultrasonic treatment is 0.5 - 1 h.

[0022] Optionally, the concentration of carbon nanomaterials in the carbon nanomaterial dispersion liquid is 5 mg·mL.

[0023] Optionally, the solvent includes at least one of water, ethanol, DMSO, and THF.

[0024] Optionally, the carbon nanomaterials include graphene and / or carbon nanotubes.

[0025] Optionally, for every 1 mg·mL increase in the concentration of the carbon nanomaterials, the time of ultrasonic treatment is extended by 30 min.

[0026] The present invention also discloses the application of the carbon nanomaterial dispersant of the above - mentioned nano - building unit biological macromolecules in serving as a high - polarity agent to combine carbon nanomaterials with a polymer or a solvent.

[0027] Optionally, the solvent includes at least one of water, THF, and DMSO.

[0028] Implementing the embodiments of the present invention will have the following beneficial effects:

[0029] The carbon nanomaterial dispersant of the nanoscale building block biopolymer provided by the present invention has the following characteristics: (1) Intrinsic hydrophobicity, with a hydrophobic angle of 115° to 130°; (2) Large aspect ratio, with a diameter of 2 to 4 nm and a length of 150 to 300 nm; (3) High viscosity, with a viscosity of 0.70 to 4.50 Pa·s when the concentration of the carbon nanomaterial dispersant is 0.1% to 0.5%; and a viscosity of 8.88 to 12.84 Pa·s when the concentration is 1% to 2%; (4) High charge, with a Zeta potential (effective external charge) usually being -68 to -94 mV.

[0030] The carbon nanomaterial dispersant of the nanoscale building block biopolymer provided by the present invention can highly disperse carbon nanomaterials (graphene, carbon nanotubes) in organic solvents such as water, ethanol, DMSO, and THF at a dosage of 0.1% to 0.5%. At the same time, the dispersant can also act as a high polarity to combine carbon nanomaterials (graphene, carbon nanotubes) with other materials. Therefore, the present invention has broad application prospects. Description of the Drawings

[0031] Figure 1 It is a test chart of the aspect ratio of the carbon nanomaterial dispersant of the nanoscale building block biopolymer in Example 2 of the present invention.

[0032] Figure 2 It is the water contact angle of the carbon nanomaterial dispersant of the nanoscale building block biopolymer in Example 2 of the present invention.

[0033] Figure 3 It is the viscosity of the carbon nanomaterial dispersant of the nanoscale building block biopolymer in Example 2 of the present invention.

[0034] Figure 4 It is the Zeta of the carbon nanomaterial dispersant of the nanoscale building block biopolymer in Example 2 of the present invention.

[0035] Figure 5 It is the effect diagram of graphene in different solvents without adding a dispersant in Comparative Example 1 of the present invention.

[0036] Figure 6 It is the dispersion effect diagram of graphene in different types of biological dispersants in Comparative Examples 2 - 3 of the present invention.

[0037] Figure 7Dispersion effect diagrams of graphene in different solvents assisted by the carbon nanomaterial dispersant of the present invention in Example 3. Detailed implementation manners

[0038] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited in any way.

[0039] Example 1

[0040] Take 100-mesh ramie stalk powder. After washing 10 grams of it with demineralized water three times, carry out alternating cooking three times. The steps of each alternating cooking are as follows:

[0041] (1) Add 100 mL of cooking solution to the washed ramie stalk powder. The cooking solution includes 8% NaOH and 3% sodium chlorite. Cook at 80 °C for 1 h, wash three times with distilled water, and ball mill for 75 min to obtain biodegradable nano-architectural unit biopolymers with a large aspect ratio (diameter of 5 - 6 nm and length of 200 - 400 nm).

[0042] (2) Take 5 grams of the biopolymers prepared in step (1), add 100 mL of cooking solution. The cooking solution includes 4% acidic pectin lyase (Cangzhou Xiasheng Enzyme Biotechnology Co., Ltd., acidic pectin lyase, initial enzyme activity 170 U / mL), 0.2% glacial acetic acid, and 0.3% glycerol. Cook at 60 °C for 1 h, wash three times with distilled water, and ball mill for 20 min to obtain biodegradable, highly charged, hydrophobic nano-architectural unit biopolymer carbon nanomaterial dispersants with a large aspect ratio (diameter of 2 - 4 nm and length of 100 - 200 nm).

[0043] Example 2

[0044] This example is different from Example 1 only in that: the preparation parameters in step (2) are changed. Specifically as follows:

[0045] (2) Take 5 grams of the biopolymers prepared in step (1) of Example 1, add 100 mL of cooking solution. The cooking solution includes 3% acidic pectin lyase, 0.3% glacial acetic acid, and 0.2% glycerol. Cook at 70 °C for 1 h, wash three times with distilled water, and ball mill for 10 min to obtain biodegradable, highly charged, hydrophobic nano-architectural unit biopolymer carbon nanomaterial dispersants with a large aspect ratio (diameter of 3 - 4 nm and length of 150 - 300 nm).

[0046] Example 3

[0047] Graphene was added to water, ethanol, DMSO, and THF respectively. Under the action of the carbon nanomaterial dispersant prepared in Example 1 at a concentration of 0.2%, it was dispersed by ultrasonic treatment for 30 min to achieve the dispersion of graphene with a concentration of 5 mg·mL in water, ethanol, DMSO, and THF respectively, obtaining a dispersion of graphene, as Figure 7 shown.

[0048] Example 4

[0049] Carbon nanotubes were added to ethanol. Under the action of the carbon nanomaterial dispersant prepared in Example 1 at a concentration of 0.3%, it was dispersed by ultrasonic treatment for 30 min to achieve the dispersion of carbon nanotubes with a concentration of 5 mg·mL in ethanol, obtaining a dispersion of carbon nanotubes.

[0050] Example 5

[0051] Graphene was added to DMSO. Under the action of the carbon nanomaterial dispersant prepared in Example 2 at a concentration of 0.2%, it was dispersed by ultrasonic treatment for 40 min to achieve the dispersion of graphene with a concentration of 5 mg·mL in DMSO, obtaining a dispersion of graphene.

[0052] Example 6

[0053] Carbon nanotubes were added to THF. Under the action of the carbon nanomaterial dispersant prepared in Example 2 at a concentration of 0.4%, it was dispersed by ultrasonic treatment for 40 min to achieve the dispersion of carbon nanotubes with a concentration of 5 mg·mL in THF, obtaining a dispersion of carbon nanotubes.

[0054] Example 7

[0055] Graphene was added to ethanol. Under the action of the carbon nanomaterial dispersant prepared in Example 1 at a concentration of 0.1%, it was dispersed by ultrasonic treatment for 30 min to achieve the dispersion of graphene with a concentration of 5 mg·mL in ethanol, obtaining a dispersion of graphene.

[0056] Example 8

[0057] Graphene was added to ethanol. Under the action of the carbon nanomaterial dispersant prepared in Example 1 at a concentration of 0.5%, it was dispersed by ultrasonic treatment for 30 min to achieve the dispersion of graphene with a concentration of 5 mg·mL in ethanol, obtaining a dispersion of graphene.

[0058] Comparative Example 1

[0059] This comparative example is compared with Example 3. The only difference is that no dispersant is added, as Figure 5 shown.

[0060] Comparative Example 2

[0061] This comparative example is different from Example 3 only in that the dispersant is a biopolymer prepared by a conventional chemical method (nanocrystalline cellulose purchased from FlashThink Technology), as Figure 6 shown.

[0062] Test Example

[0063] 1. The performance of the carbon nanomaterial dispersant prepared in Example 2 was tested, as Figures 1-4 shown, indicating that the carbon nanomaterial dispersant prepared in Example 2 has hydrophobicity, a large aspect ratio, high viscosity, and high charge.

[0064] 2. According to Figure 5 , Figure 6 and Figure 7 comparison shows that, compared with the comparative example, the carbon nanomaterial dispersant using the nanobuilding unit biopolymer provided by the present invention can disperse graphene at a high concentration in water, ethanol, DMSO, and THF under low-concentration conditions, and has a good dispersion effect.

[0065] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of this invention patent shall be subject to the appended claims.

Claims

1. A carbon nanomaterial dispersant for biological macromolecules of nanoscale building units, characterized in that, Its chemical structural formula is shown in Formula I:

2. The carbon nanomaterial dispersant for biological macromolecules of the nano-building unit according to claim 1, wherein The hydrophobic angle of the carbon nanomaterial dispersant is 115°-130°.

3. The carbon nanomaterial dispersant for biomacromolecules of the nanoscale building units according to claim 1, characterized in that, The diameter of the carbon nanomaterial dispersant is 2-4 nm, and the length is 150-300 nm.

4. The carbon nanomaterial dispersant for biomacromolecules of the nano building units according to claim 1, characterized in that, The zeta potential of the carbon nanomaterial dispersant is -68 to -94 mV.

5. The carbon nanomaterial dispersant for biological macromolecules of the nano building unit according to claim 1, characterized in that, The viscosity of the carbon nanomaterial dispersant under the condition of a concentration of 0.1%-0.5% is 0.70-4.50 Pa·s.

6. A preparation method of a carbon nanomaterial dispersant for a nano-constructed unit biopolymer as described in any one of claims 1-5, characterized in that, It includes the following steps: Carry out alternating cooking on the ramie stalk powder. The number of times of the alternating cooking is 2-3 times. Each step of the alternating cooking is as follows: (1) Mix the ramie stalk powder, NaOH and sodium chlorite, and carry out cooking at 60-80°C for 1 h-2 h, and then carry out ball milling for 30-75 min to obtain biological macromolecules; (2) Mix the biological macromolecules with acidic pectin lyase, glacial acetic acid and glycerol, and carry out cooking at 50-70°C for 1 h-2 h, and then carry out ball milling for 20-30 min to obtain the carbon nanomaterial dispersant.

7. The preparation method according to claim 6, wherein, In step (1), the particle size of the ramie stalk powder is 100 mesh; the mass concentration of NaOH is 4%-10%; the mass concentration of sodium chlorite is 1%-3%; the bath ratio of the ramie stalk powder to NaOH and sodium chlorite solution is 1:8; In step (2), the mass concentration of the acidic pectin lyase is 1%-4%; the mass concentration of glacial acetic acid is 0.2%-0.6%; the mass concentration of glycerol is 0.1%-0.3%; the bath ratio of the biological macromolecules to the acidic pectin lyase, glacial acetic acid and glycerol solution is 1:

8.

8. Use of a carbon nanomaterial dispersant for a nanoscale building unit biopolymer as described in any one of claims 1-5 in the preparation of a carbon nanomaterial dispersion, characterized in that, It includes the following steps: Add the carbon nanomaterial into an organic solvent, and under the action of 0.1%-0.5% of the carbon nanomaterial dispersant, carry out dispersion by ultrasonic treatment to realize the dispersion of a high-concentration carbon nanomaterial in the organic solvent, and obtain a carbon nanomaterial dispersion liquid.

9. The application according to claim 8, wherein The time of the ultrasonic treatment is 0.5-1 h; The concentration of the carbon nanomaterial in the carbon nanomaterial dispersion liquid is 5 mg·mL; The solvent includes at least one of water, ethanol, DMSO, and THF; The carbon nanomaterial includes graphene and / or carbon nanotubes; For every 1 mg·mL increase in the concentration of the carbon nanomaterial, the ultrasonic time is extended by 30 min.

10. Application of a carbon nanomaterial dispersant of a nano-structuring unit biological macromolecule as described in any one of claims 1-5 in making a carbon nanomaterial combine with a high-polarity polymer or solvent.

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