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CN-119663478-B - Chitin nanofiber, bottom-up self-assembled preparation method thereof and transparent chitin nanofiber membrane

CN119663478BCN 119663478 BCN119663478 BCN 119663478BCN-119663478-B

Abstract

The invention belongs to the technical field of natural polymer fiber preparation, and particularly relates to a chitin nanofiber, a bottom-up self-assembly preparation method thereof and a transparent chitin nanofiber membrane. The preparation method of the invention utilizes alkali solution to dissolve the chitin, combines aging and heating treatment, and realizes the efficient preparation of the chitin nanofiber assembled from bottom to top (namely, based on molecular or nano-level oligomer, the characteristic of self-assembly in nature is utilized to form a macroscopic structure) through a simple physical process. The method has the advantages that only the alkali solution is used as the solvent, so that the use of harmful solvents is avoided, and the environment friendliness of the process is ensured. In addition, the prepared chitin nanofiber has a good spiral structure, and can show good performance and adaptability in different applications.

Inventors

  • DUAN BO
  • LIN XINGHUAN
  • FENG YUXIN
  • ZHENG ANMIN

Assignees

  • 武汉科技大学

Dates

Publication Date
20260505
Application Date
20241225

Claims (8)

  1. 1. A preparation method of chitin nanofiber by self-assembling from bottom to top is characterized by comprising the following steps: dispersing chitin in an alkali solution to obtain chitin dispersion; Sequentially freezing and thawing the chitin dispersion liquid to obtain chitin solution; sequentially aging, heat treatment and dialysis are carried out on the chitin solution to obtain the chitin nanofiber, wherein the aging temperature is 5-30 ℃, the heat preservation time is 5-30 hours, the heat treatment temperature is 40-100 ℃, and the heat preservation time is 0.5-7 hours; The length of the chitin nanofiber is hundreds of nanometers to micrometers, and the chitin nanofiber has a spiral and nodular structure.
  2. 2. The method according to claim 1, wherein the alkali solution comprises one or more of sodium hydroxide solution, potassium hydroxide solution and lithium hydroxide solution; The mass concentration of the alkali solution is 20-50%; The mass ratio of the chitin to the alkali solution is 1:3-24; the dispersing temperature is room temperature, and the dispersing time is 4-20 hours.
  3. 3. The method according to claim 1, further comprising diluting the chitin dispersion with water before freezing; the mass concentration of the chitin in the diluted system is 1-10%, and the mass concentration of the alkali is 5-20%.
  4. 4. The preparation method of claim 1, wherein the freezing temperature is-25 to-40 ℃ and the time is 1-12 hours, and the thawing temperature is room temperature and the time is 2-12 hours; the cycle times of freezing and thawing are 1-5 times.
  5. 5. The method according to claim 1, wherein the dialysis bag used for dialysis has a molecular weight cut-off of Mw 8000-14000.
  6. 6. The method according to claim 1 or 5, wherein the dialysis is performed at a temperature of 5-30 ℃ for a period of 1-5 days.
  7. 7. The chitin nanofiber prepared by the preparation method of any one of claims 1-6, wherein the chitin nanofiber has a spiral and nodular structure.
  8. 8. A transparent chitin nanofiber membrane, characterized in that the preparation raw material comprises the chitin nanofiber according to claim 7.

Description

Chitin nanofiber, bottom-up self-assembled preparation method thereof and transparent chitin nanofiber membrane Technical Field The invention belongs to the technical field of natural polymer fiber preparation, and particularly relates to a chitin nanofiber, a bottom-up self-assembly preparation method thereof and a transparent chitin nanofiber membrane. Background In recent decades, with the rapid development of nanotechnology, research and application of natural polymer materials have gradually attracted extensive attention. The polymer nanofiber is applied to a plurality of fields, in particular important materials in biomedical science, environment, food packaging and the like due to excellent mechanical property, biocompatibility and controllable physicochemical property. Chitin, which is a natural polysaccharide derived from shells of shrimps and crabs, has excellent biocompatibility and biodegradability as well as good antibacterial properties, and thus has been attracting attention in nanomaterial research. The traditional preparation method of the chitin nanofiber mainly comprises a quasi-solvent stripping method, a mechanical stripping method, a Tempo oxidation method and the like. Although these methods can provide certain nanofiber products, there are typically drawbacks of solvent contamination, high energy consumption, complex processes, and low yields. In addition, traditional chemical modification methods also present potential risks in terms of environment and health, limiting their use in a wider range of fields. Disclosure of Invention The invention aims to provide a chitin nanofiber, a preparation method of the chitin nanofiber and a transparent chitin nanofiber membrane from bottom to top. In order to achieve the above object, the present invention provides the following technical solutions: The invention provides a preparation method of chitin nanofiber by self-assembling from bottom to top, which comprises the following steps: dispersing chitin in an alkali solution to obtain chitin dispersion; Sequentially freezing and thawing the chitin dispersion liquid to obtain chitin solution; And (3) sequentially aging, heat treatment and dialysis the chitin solution to obtain the chitin nanofiber. Preferably, the alkali solution comprises one or more of sodium hydroxide solution, potassium hydroxide solution and lithium hydroxide solution; The mass concentration of the alkali solution is 20-50%; The mass ratio of the chitin to the alkali solution is 1:3-24; the dispersing temperature is room temperature, and the dispersing time is 4-20 hours. Preferably, before the freezing, the method further comprises the step of adding water into the chitin dispersion liquid for dilution; the mass concentration of the chitin in the diluted system is 1-10%, and the mass concentration of the alkali is 5-20%. Preferably, the freezing temperature is-25 to-40 ℃ and the time is 1-12 hours, and the thawing temperature is room temperature and the time is 2-12 hours; the cycle times of freezing and thawing are 1-5 times. Preferably, the aging temperature is 5-30 ℃, and the heat preservation time is 5-30 hours. Preferably, the temperature of the heat treatment is 40-100 ℃, and the heat preservation time is 0.5-7 h. Preferably, the molecular weight cut-off of the dialysis bag used for dialysis is Mw 8000-14000. Preferably, the dialysis temperature is 5-30 ℃ and the dialysis time is 1-5 days. The invention also provides the chitin nanofiber prepared by the preparation method of the technical scheme, and the chitin nanofiber has a spiral and nodular structure. The invention also provides a transparent chitin nanofiber membrane, and the preparation raw materials comprise the chitin nanofiber according to the technical scheme. The invention provides a bottom-up self-assembly preparation method of chitin nanofibers, which comprises the following steps of dispersing chitin in an alkali solution to obtain chitin dispersion liquid, sequentially freezing and thawing the chitin dispersion liquid to obtain chitin solution, and sequentially aging, heat treatment and dialysis the chitin solution to obtain the chitin nanofibers. The preparation method of the invention utilizes alkali solution to dissolve the chitin, combines aging and heating treatment, and realizes the efficient preparation of the chitin nanofiber assembled from bottom to top (namely, based on molecular or nano-level oligomer, the characteristic of self-assembly in nature is utilized to form a macroscopic structure) through a simple physical process. The method has the advantages that only the alkali solution is used as the solvent, so that the use of harmful solvents is avoided, and the environment friendliness of the process is ensured. In addition, the prepared chitin nanofiber has a good spiral structure, and can show good performance and adaptability in different applications. The invention not only provides a preparation method of high-efficiency and green s