CN112226848B

CN112226848B - Chitosan-graphene oxide composite fiber and preparation method and application thereof

Info

Publication number: CN112226848B
Application number: CN202010915429.9A
Authority: CN
Inventors: 拜永孝; 金丽君; 党锡江; 张桂兰
Original assignee: Fangda Carbon New Material Co ltd; Lanzhou University
Current assignee: Fangda Carbon New Material Co ltd; Lanzhou University
Priority date: 2020-09-03
Filing date: 2020-09-03
Publication date: 2022-11-29
Anticipated expiration: 2040-09-03
Also published as: CN112226848A

Abstract

The invention discloses a preparation method of chitosan-graphene oxide composite fiber, which comprises the steps of adding a graphene oxide aqueous solution into a chitosan aqueous dispersion, mixing, adding glacial acetic acid, stirring to obtain a spinning stock solution, defoaming, extruding, solidifying, stretching, soaking, adding dopamine, and soaking to obtain the chitosan-graphene oxide composite fiber; the chitosan-graphene oxide composite fiber prepared by the preparation method of the chitosan-graphene oxide composite fiber is also provided. According to the invention, a solution compounding method is adopted to graft micromolecular graphene oxide onto chitosan macromolecules, so that the interaction between chitosan molecules is enhanced. The chitosan-graphene oxide composite fiber with greatly improved antibacterial property and tensile strength is prepared by wet spinning.

Description

Chitosan-graphene oxide composite fiber and preparation method and application thereof

Technical Field

The invention relates to the technical field of preparation of composite fibers. More specifically, the invention relates to a chitosan-graphene oxide composite fiber, and a preparation method and application thereof.

Background

The chitosan chitin N-deacetylated product has stronger reactivity of amino groups in a chitosan molecular structure than acetylamino groups in chitin molecules, so that the chitosan has excellent biological functions and can perform chemical modification reaction. As a natural polymer material, the chitosan has wide source and low cost, and is a green raw material with great application value. The chitosan fiber can be prepared by wet spinning, and has excellent biocompatibility, antibacterial property, degradability and the like. However, the chitosan fiber has poor mechanical properties due to the existence of more intermolecular and intramolecular hydrogen bonds in the chitosan molecular structure, and the strength of the chitosan fiber in practical application is difficult to achieve, so that the application of the chitosan fiber in practical life is limited to a great extent. Graphene, which is the thinnest and lightest small molecular material, is a common polymer reinforcing agent and is often used for optimizing the mechanical properties of polymer materials. However, the dispersibility of graphene is poor due to the special molecular structure of graphene, and the defect causes that graphene cannot be applied to the wet spinning preparation of chitosan.

Disclosure of Invention

It is an object of the present invention to address at least the above problems and to provide at least the advantages described hereinafter.

The invention also aims to provide a preparation method of the chitosan-graphene oxide composite fiber, which comprises the steps of adding the graphene oxide aqueous solution into the chitosan aqueous dispersion, mixing, adding glacial acetic acid, stirring to obtain a spinning solution, defoaming, extruding, solidifying, stretching, soaking, and adding dopamine for soaking to obtain the chitosan-graphene oxide composite fiber. By utilizing the graphene oxide, the problem of poor graphene dispersibility is solved, the prepared composite fiber is excellent in mechanical property, and the composite fiber prepared by the preparation method is good in antibacterial effect.

In order to achieve these objects and other advantages in accordance with the present invention, a method for preparing chitosan-graphene oxide composite fibers is provided, which comprises adding an aqueous solution of graphene oxide into an aqueous dispersion of chitosan, mixing, adding glacial acetic acid, stirring to obtain a spinning dope, defoaming, extruding, solidifying, stretching, soaking, adding dopamine, and impregnating to obtain chitosan-graphene oxide composite fibers.

Preferably, the chitosan mass content in the chitosan water dispersion is 4.0-6.0 wt%;

the mass ratio of the graphene oxide to the chitosan in the graphene oxide aqueous solution is 0.008-0.015;

the chitosan has a degree of deacetylation greater than 80%.

Preferably, the volume of the glacial acetic acid is 6-10% of the volume of the spinning solution, the stirring temperature is 10-50 ℃, and the stirring time is 4-8 h.

Preferably, the coagulation bath for coagulation is a mixed solution of an aqueous sodium hydroxide solution and ethanol, and the temperature of the coagulation bath is 20 to 50 ℃.

Preferably, the stretching is performed under a water bath condition of 50 to 90 ℃, and the draw ratio of the stretching is 1.5 to 3.2 times.

Preferably, the soaking is performed in an alkaline solution having a pH of 7.2 to 10.5.

Preferably, the dopamine accounts for 0.001-0.05 wt% of the alkaline solution, the dipping temperature is 10-50 ℃, and the time is 2-24 h.

A chitosan-graphene oxide composite fiber is prepared by a preparation method of the chitosan-graphene oxide composite fiber.

An application of chitosan-graphene oxide composite fiber in preparation of surgical suture.

Due to the fact that the graphene has poor dispersity caused by the special molecular structure, the graphene cannot be directly applied to the wet spinning preparation of chitosan due to the defect. Graphene oxide, which is the most important derivative of graphene, can greatly improve the dispersibility of graphene in water by grafting oxygen-containing functional groups, such as carboxyl, hydroxyl and the like, on the surface or edge of graphene. According to the invention, graphene oxide with excellent water dispersibility is adopted to modify chitosan macromolecules, the graphene oxide can be grafted to the chitosan macromolecules through high-activity oxygen-containing groups on the surface and the edge of the graphene oxide, the structure of the chitosan macromolecules is changed, and the graphene oxide reinforced chitosan-graphene oxide composite fibers are prepared through wet spinning.

The deacetylation degree of chitosan corresponds to the content of amino groups on a macromolecular chain, the number of the amino groups on the macromolecular chain of chitosan is increased along with the increase of the deacetylation degree, a large amount of amino groups are protonated to increase the charged groups of the chitosan in a dilute acid solution, the charge density of polyelectrolyte is increased, and the structure, property and performance of the chitosan can be changed. When the deacetylation degree of the chitosan is less than 60%, the content of amine groups on a chitosan molecular chain is low, the fibrilization of the chitosan is extremely poor due to winding among macromolecular chains, and the chitosan has good fibrilization only when the deacetylation degree of the chitosan is high. The chitosan fiber prepared by the method has excellent mechanical properties.

Dopamine is a biologically safe micromolecular drug, is used as a reaction monomer, and can be subjected to polymerization reaction under an alkaline condition by taking oxygen as an oxidant to obtain polydopamine. Under the alkaline condition, dopamine monomer catechol can form dopamine quinone after deprotonation oxidation, but the structure of the dopamine quinone is unstable and can be continuously oxidized, intramolecular rearrangement and crosslinking are carried out, and dark brown polydopamine is formed. The polydopamine has good adhesion performance, can be effectively adhered to the surface of a substrate, and can generate a uniform and compact polydopamine coating on the surface of the substrate after a certain reaction time. Enhancing the biocompatibility of the substrate material. According to the invention, the chitosan-graphene oxide composite fiber is soaked in the polydopamine solution obtained from the dopamine alkaline solution for a period of time, so that a layer of compact and uniform polydopamine can be coated on the surface of the composite fiber, the mechanical property of the composite fiber is further improved, the antibacterial property of the composite fiber can be enhanced, and the obtained treated fiber can be used as an operation suture.

The invention at least comprises the following beneficial effects:

according to the method, a solution compounding method is adopted to graft micromolecular graphene oxide onto chitosan macromolecules, so that the interaction between chitosan molecules is enhanced;

compared with pure chitosan fiber, the chitosan-graphene oxide composite fiber prepared by wet spinning has obviously improved mechanical property;

dopamine is polymerized in an alkaline environment to generate polydopamine, and the polydopamine is adhered to the surface of the chitosan-graphene oxide composite fiber to obtain a treated composite fiber, so that the mechanical property of the composite fiber is further improved;

the graphene oxide micromolecules have excellent antibacterial performance, and the antibacterial rate of the prepared composite fiber to staphylococcus aureus and escherichia coli is more than 99.9% by cooperating with the biological safety performance of dopamine to act on the chitosan fiber.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

Fig. 1 is a flowchart illustrating a process for preparing graphene oxide-chitosan composite fibers according to an embodiment of the present invention;

fig. 2 is a scanning electron microscope image of the surface of the graphene oxide-chitosan composite fiber according to embodiment 1 of the present invention;

fig. 3 is a scanning electron microscope image of a cross section of the graphene oxide-chitosan composite fiber in example 1 of the present invention.

Detailed Description

The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.

It is to be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified.

< example 1>

A preparation method of chitosan-graphene oxide composite fibers specifically comprises the following steps:

step one, weighing 4.0g of chitosan with deacetylation degree of more than 80 percent, and dispersing the chitosan in 84mL of deionized water at a mechanical stirring speed of 200rppm to obtain chitosan water dispersion;

step two, adding 10mL of graphene oxide aqueous solution with the content of 4mg/mL into the chitosan aqueous dispersion, and stirring for 10min to obtain graphene oxide-chitosan aqueous dispersion; adding 6mL of glacial acetic acid into the graphene oxide-chitosan aqueous dispersion, and continuously stirring for 8h at 10 ℃ to obtain a uniform graphene oxide-chitosan spinning stock solution;

step three, centrifuging the spinning solution obtained in the step two at the rotating speed of 4500rppm for 4min to remove bubbles, and extruding the spinning solution into a mixed solution of sodium hydroxide aqueous solution and ethanol at 30 ℃ through a digital metering pump at the extrusion rate of 0.2mL/min to obtain graphene oxide-chitosan nascent fiber;

step four, immersing the nascent fiber obtained in the step three in a water bath at 60 ℃ and stretching the nascent fiber by 1.5 times to obtain graphene oxide-chitosan composite fiber;

and step five, soaking the composite fiber obtained in the step four in 100mL of alkaline solution with the pH value of 7.8, then adding 0.01g of dopamine, and soaking the fiber for 16 hours at the temperature of 20 ℃ to obtain the treated graphene oxide-chitosan composite fiber.

Referring to fig. 1, a schematic flow diagram of a process for preparing graphene oxide-chitosan composite fibers by wet spinning is shown, and scanning electron microscope images of the graphene oxide-chitosan composite fibers are shown in fig. 2 and fig. 3.

< example 2>

step one, weighing 5g of chitosan with deacetylation degree of more than 80 percent, and dispersing the chitosan in 83mL of deionized water at a mechanical stirring speed of 200rppm to obtain chitosan water dispersion;

step two, adding 10mL of graphene oxide aqueous solution with the content of 5mg/mL into the chitosan aqueous dispersion, and stirring for 10min to obtain graphene oxide-chitosan aqueous dispersion; adding 7mL of glacial acetic acid into the graphene oxide-chitosan aqueous dispersion, and continuously stirring for 6h at 50 ℃ to obtain a uniform graphene oxide-chitosan spinning stock solution;

step three, centrifuging the spinning solution obtained in the step two for 4min at the rotating speed of 4500rppm to remove air bubbles, and extruding the spinning solution into a mixed solution of a sodium hydroxide aqueous solution and ethanol at 20 ℃ through a digital metering pump at the extrusion rate of 0.2mL/min to obtain the graphene oxide-chitosan nascent fiber;

step four, immersing the nascent fiber obtained in the step three in a water bath at 90 ℃ and stretching by 3.2 times to obtain graphene oxide-chitosan composite fiber;

and step five, soaking the composite fiber obtained in the step four in 100mL of alkaline solution with the pH value of 8.3, then adding 0.001g of dopamine, and soaking the fiber for 20 hours at the temperature of 30 ℃ to obtain the treated graphene oxide-chitosan composite fiber.

< example 3>

step one, weighing 4.0g of chitosan with deacetylation degree of more than 80 percent, and dispersing the chitosan in 80mL of deionized water at a mechanical stirring speed of 200rppm to obtain chitosan water dispersion;

step two, adding 10mL of graphene oxide aqueous solution with the content of 5mg/mL into the chitosan aqueous dispersion, and stirring for 10min to obtain graphene oxide-chitosan aqueous dispersion; adding 10mL of glacial acetic acid into the graphene oxide-chitosan aqueous dispersion, and continuously stirring for 4h at 40 ℃ to obtain a uniform graphene oxide-chitosan spinning stock solution;

step three, centrifuging the spinning solution obtained in the step two at the rotating speed of 4500rppm for 4min to remove bubbles, and extruding the spinning solution into a mixed solution of a sodium hydroxide aqueous solution and ethanol at 50 ℃ through a digital metering pump at the extrusion rate of 0.2mL/min to obtain graphene oxide-chitosan nascent fibers;

step four, immersing the nascent fiber obtained in the step three in a water bath at 50 ℃ and stretching the nascent fiber by 2.0 times to obtain graphene oxide-chitosan composite fiber;

and step five, soaking the composite fiber obtained in the step four in 100mL of alkaline solution with the pH value of 10.5, then adding 0.05g of dopamine, and soaking the fiber for 2 hours at 50 ℃ to obtain the treated graphene oxide-chitosan composite fiber.

< example 4>

step one, weighing 5.0g of chitosan with deacetylation degree of more than 80 percent, and dispersing the chitosan in 82mL of deionized water at a mechanical stirring speed of 200rppm to obtain chitosan water dispersion;

step two, adding 10mL of graphene oxide aqueous solution with the content of 7.5mg/mL into the chitosan aqueous dispersion, and stirring for 10min to obtain graphene oxide-chitosan aqueous dispersion; adding 8mL of glacial acetic acid into the graphene oxide-chitosan aqueous dispersion, and continuously stirring for 5h at 30 ℃ to obtain a uniform graphene oxide-chitosan spinning stock solution;

step three, centrifuging the spinning solution obtained in the step two for 4min at the rotating speed of 4500rppm to remove air bubbles, and extruding the spinning solution into a mixed solution of a sodium hydroxide aqueous solution and ethanol at the temperature of 30 ℃ through a digital metering pump at the extrusion rate of 0.2mL/min to obtain the graphene oxide-chitosan nascent fiber;

step four, immersing the nascent fiber obtained in the step three in a water bath at 70 ℃ and stretching by 2.5 times to obtain graphene oxide-chitosan composite fiber;

and step five, soaking the composite fiber obtained in the step four in 100mL of alkaline solution with the pH value of 9.0, then adding 0.02g of dopamine, and soaking the fiber for 24 hours at 10 ℃ to obtain the treated graphene oxide-chitosan composite fiber.

< comparative example 1>

Comparative example 1 is different from example 1 in that chitosan was dissolved in an acetic acid solution having a volume concentration of 6% in step one, glacial acetic acid was not added in step two, and the other steps were the same as example 1.

< comparative example 2>

The difference between the comparative example 2 and the example 1 is that graphene oxide is not added in the second step, the chitosan pure sample composite fiber is obtained through the fourth step, post-treatment is not carried out on the fiber, and other steps are the same as those of the example 1.

< comparative example 3>

The comparative example 3 is different from the example 1 in that the graphene oxide-chitosan composite fiber is prepared through the fourth step, the composite fiber is not subjected to post-treatment, and other steps are the same as the example 1.

< comparative example 4>

Comparative example 4 is different from example 1 in that a chitosan raw material having a degree of deacetylation of 72.8% was used in the first step, and the other steps were the same as in example 1.

< comparative example 5>

The difference between comparative example 5 and example 1 is that 0.05g of dopamine was added to 10mL of graphene oxide aqueous solution in step two, and no dopamine was added in step five, and the other steps were the same as example 1.

< test on Properties of composite fibers >

The composite fibers of examples 1 to 4 and comparative examples 1 to 5 were subjected to a bacteriostasis test, and the results were counted using a plate counting method, and the test results are shown in the following table.

As can be seen from the table above, the composite fibers of examples 1 to 4 have better bacteriostatic rate and mechanical properties than those of comparative examples 1 to 5. As can be seen from examples 1 to 4 and comparative example 2, the composite fiber formed by combining chitosan and graphene oxide has better mechanical new performance. As can be seen from examples 1 to 4 and comparative examples 1, 3 and 5, the composite fiber prepared by the preparation steps of the invention has good bacteriostatic effect. As can be seen from examples 1 to 4 and comparative example 4, the composite fiber prepared by using chitosan with deacetylation degree of more than 80% has good mechanical property.

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable to various fields of endeavor for which the invention may be embodied with additional modifications as would be readily apparent to those skilled in the art, and the invention is therefore not limited to the details given herein and to the embodiments shown and described without departing from the generic concept as defined by the claims and their equivalents.

Claims

1. A preparation method of chitosan-graphene oxide composite fibers is characterized in that graphene oxide aqueous solution is added into chitosan aqueous dispersion to be mixed, glacial acetic acid is added to be stirred to obtain spinning dope, and the spinning dope is defoamed, extruded, solidified, stretched and soaked, and then dopamine is added to be soaked to obtain the chitosan-graphene oxide composite fibers; the stretching is carried out under the water bath condition of 50 to 90 ℃, and the draw-up multiplying power of the stretching is 1.5 to 3.2 times;

the mass content of chitosan in the chitosan water dispersion liquid is 4.0-6.0 wt%;

the mass ratio of the graphene oxide to the chitosan in the graphene oxide aqueous solution is 0.008 to 0.015;

the deacetylation degree of the chitosan is more than 80%;

the soaking is carried out in an alkaline solution with the pH value of 7.2 to 10.5; the dopamine accounts for 0.001 to 0.05wt% of the alkaline solution, the dipping temperature is 10 to 50 ℃, and the time is 2 to 24h.

2. The method for preparing the chitosan-graphene oxide composite fiber according to claim 1, wherein the volume of glacial acetic acid is 6 to 10% of the volume of the spinning dope, the stirring temperature is 10 to 50 ℃, and the stirring time is 4 to 8h.

3. The method for producing a chitosan-graphene oxide composite fiber according to claim 1, wherein a mixed solution of an aqueous solution of sodium hydroxide and ethanol is used as a coagulation bath for the coagulation treatment, and the temperature of the coagulation bath is 30 to 50 ℃.

4. A chitosan-graphene oxide composite fiber, which is prepared by the preparation method according to any one of claims 1 to 3.

5. Use of the chitosan-graphene oxide composite fiber of claim 4 in the preparation of a surgical suture.