阅读说明：本技术 一种聚多巴胺涂覆氧化石墨烯基三元人造珍珠层材料及其制备方法 (Polydopamine-coated graphene oxide-based ternary artificial pearl layer material and preparation method thereof ) 是由 刘镇波 李慕之 于 2019-09-23 设计创作，主要内容包括：一种聚多巴胺涂覆氧化石墨烯基三元人造珍珠层材料及其制备方法,它属于仿生材料制备方法领域。为解决现有氧化石墨烯基仿生材料力学性能差、电导率低等问题,本发明首先配制多巴胺溶液,将溶液pH值调整至8.5。放入氧化石墨烯/纳米纤维素/聚多巴胺人造珍珠层材料,取出清洗并干燥后,得到聚多巴胺涂覆的氧化石墨烯基三元人造珍珠层。将材料再次浸入硝酸铜溶液中,在超声的过程中滴加磷酸二氢钠溶液,取出清洗并干燥。本发明继承并提高了原有材料的拉伸强度,此外,涂层表面涂覆的铜纳米颗粒能够显著提高材料的电导率,在柔性能源设备、超级电容器以及其他电子设备中具有广泛的应用前景。(A polydopamine-coated graphene oxide-based ternary artificial pearl layer material and a preparation method thereof, belonging to the field of preparation methods of bionic materials. In order to solve the problems of poor mechanical property, low conductivity and the like of the existing graphene oxide-based bionic material, the invention firstly prepares a dopamine solution, and adjusts the pH value of the solution to 8.5. Putting the graphene oxide/nano-cellulose/polydopamine artificial pearl layer material into the container, taking out the material, cleaning and drying the material to obtain the polydopamine coated graphene oxide-based ternary artificial pearl layer. The material was again immersed in the copper nitrate solution, and a sodium dihydrogen phosphate solution was added dropwise during sonication, taken out, washed and dried. The invention inherits and improves the tensile strength of the original material, and in addition, the copper nanoparticles coated on the surface of the coating can obviously improve the conductivity of the material, thereby having wide application prospect in flexible energy devices, supercapacitors and other electronic devices.)

1. A preparation method of a polydopamine-coated graphene oxide-based ternary artificial pearl layer material is characterized by comprising the following steps:

step one, respectively weighing a certain mass of dopamine, tris hydrochloride, copper nitrate and sodium dihydrogen phosphate;

step two, preparing Tris-HCl buffer solution from the Tris-aminomethane hydrochloride weighed in the step one, adding NaOH solution, and adjusting the pH value of the Tris-HCl buffer solution to 8.0-8.5;

step three, preparing a dopamine solution, adding the Tris-HCl buffer solution prepared in the step two, and adjusting the pH value of the dopamine solution to 8.0-8.5; preparing a graphene oxide/nano-cellulose/polydopamine artificial pearl layer, immersing the graphene oxide/nano-cellulose/polydopamine artificial pearl layer into a dopamine solution, taking out the graphene oxide/nano-cellulose/polydopamine artificial pearl layer after soaking for a period of time, cleaning and drying to obtain a polydopamine coated graphene oxide/nano-cellulose/polydopamine artificial pearl layer;

and step four, immersing the polydopamine-coated graphene oxide/nano-cellulose/polydopamine artificial pearl layer prepared in the step three into a copper nitrate solution, then slowly dropwise adding a sodium dihydrogen phosphate solution under an ultrasonic condition, taking out and cleaning after soaking for a period of time, and drying to obtain the polydopamine-coated graphene oxide-based ternary artificial pearl layer material.

2. The method for preparing the polydopamine-coated graphene oxide-based ternary artificial pearl layer material according to claim 1, wherein the method comprises the following steps: and the molar ratio of the copper nitrate to the sodium dihydrogen phosphate in the first step is 1: 2.

3. The method for preparing the polydopamine-coated graphene oxide-based ternary artificial pearl layer material according to claim 1, wherein the method comprises the following steps: and the concentration of the Tris-HCl buffer solution in the second step is 20-40 mg/mL, and the concentration of the NaOH solution is 0.01 mol/L.

4. The method for preparing the polydopamine-coated graphene oxide-based ternary artificial pearl layer material according to claim 1, wherein the method comprises the following steps: and the concentration of the dopamine solution in the third step is 2 mg/mL.

5. The method for preparing the polydopamine-coated graphene oxide-based ternary artificial pearl layer material according to claim 1, wherein the method for preparing the graphene oxide/nanocellulose/polydopamine artificial pearl layer in the third step comprises the following steps:

step 1, respectively weighing a certain mass of graphene oxide, nanocellulose and dopamine according to the weight fraction of 60-96: 1-25: 1-5, wherein the size range of the graphene oxide is 1.0-2.0 mu m, and the thickness of a sheet layer is 0.8-1 nm;

step 2, respectively dissolving graphene oxide and nanocellulose in deionized water, uniformly mixing the obtained graphene oxide solution and the nanocellulose solution, adding a Tris buffer solution, adjusting the pH value to 8.5, adding dopamine, and stirring for a certain time to obtain a mixed solution;

and 3, carrying out vacuum filtration on the mixed solution obtained in the step 2 to form a film, and drying the obtained film at a certain temperature for a certain time to obtain the graphene oxide/nano-cellulose/polydopamine artificial pearl layer.

6. The method for preparing the polydopamine-coated graphene oxide-based ternary artificial pearl layer material according to claim 1, wherein the method comprises the following steps: and step three, soaking for 24 hours, drying at the temperature of 45-60 ℃ for 24 hours.

7. The method for preparing the polydopamine-coated graphene oxide-based ternary artificial pearl layer material according to claim 1, wherein the method comprises the following steps: fourthly, the concentration of the copper nitrate solution is 0.02-0.05 mol/L, and the concentration of the sodium dihydrogen phosphate solution is 0.02-0.04 mol/L.

8. The method for preparing the polydopamine-coated graphene oxide-based ternary artificial pearl layer material according to claim 1, wherein the method comprises the following steps: and step four, the soaking time is 12 hours, the drying temperature is 45-60 ℃, and the drying time is 24 hours.

9. A polydopamine coated graphene oxide-based ternary artificial pearl layer material prepared by the preparation method of the polydopamine coated graphene oxide-based ternary artificial pearl layer material according to any one of claims 1 to 8, which is characterized in that: the conductivity of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material is 207.6S cm^-1。

Technical Field

The invention belongs to the field of a preparation method of a bionic material; in particular to a polydopamine-coated graphene oxide-based ternary artificial pearl layer material and a preparation method thereof.

Background

In nature, mussels exhibit excellent adhesive properties and are capable of adhering tightly to the surfaces of a variety of organic and inorganic materials. Inspired by the viscous protein component in mussels, Dopamine (DA) is commonly used as an adhesive coating for substrates. As a small organic molecule containing multiple functional groups (catechol groups, amino groups), DA can spontaneously polymerize long-chain polymer PolyDopamine (PDA) under weakly alkaline conditions (pH 8.5). In addition to excellent adhesion properties, the catechol groups abundant in PDA coatings are able to introduce functional molecules into the material surface by secondary reactions.

Disclosure of Invention

The invention aims to provide a polydopamine-coated graphene oxide-based ternary artificial pearl layer material with good conductivity and a preparation method thereof.

The invention is realized by the following technical scheme:

a preparation method of a polydopamine-coated graphene oxide-based ternary artificial pearl layer material comprises the following steps:

step one, respectively weighing a certain mass of dopamine, tris hydrochloride, copper nitrate and sodium dihydrogen phosphate;

step two, preparing Tris-HCl buffer solution from the Tris-aminomethane hydrochloride weighed in the step 1, adding NaOH solution, and adjusting the pH value of the TRIS-HCl buffer solution to 8.0-8.5;

step three, preparing a dopamine solution, adding the Tris-HCl buffer solution prepared in the step two, and adjusting the pH value of the dopamine solution to 8.0-8.5; preparing a graphene oxide/nano-cellulose/polydopamine artificial pearl layer, immersing the graphene oxide/nano-cellulose/polydopamine artificial pearl layer into a dopamine solution, taking out the graphene oxide/nano-cellulose/polydopamine artificial pearl layer after soaking for a period of time, cleaning and drying to obtain a polydopamine coated graphene oxide/nano-cellulose/polydopamine artificial pearl layer;

and step four, immersing the polydopamine-coated graphene oxide/nano-cellulose/polydopamine artificial pearl layer prepared in the step three into a copper nitrate solution, then slowly dropwise adding a sodium dihydrogen phosphate solution under an ultrasonic condition, taking out and cleaning after soaking for a period of time, and drying to obtain the polydopamine-coated graphene oxide-based ternary artificial pearl layer material.

The preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material comprises the step one, wherein the molar ratio of copper nitrate to sodium dihydrogen phosphate is 1: 2.

The preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material comprises the step two, wherein the concentration of a Tris-HCl buffer solution is 20-40 mg/mL, and the concentration of a NaOH solution is 0.01 mol/L.

The preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material provided by the invention comprises the step three, wherein the concentration of a dopamine solution is 2 mg/mL.

The invention relates to a preparation method of a polydopamine-coated graphene oxide-based ternary artificial pearl layer material, which comprises the following steps:

step 1, respectively weighing a certain mass of graphene oxide, nanocellulose and dopamine according to the weight parts of 60-96: 1-25: 1-5, wherein the size range of the graphene oxide is 1.0-2.0 mu m, and the thickness of a lamella is 0.8-1 nm;

step 2, respectively dissolving graphene oxide and nanocellulose in deionized water, uniformly mixing the obtained graphene oxide solution and the nanocellulose solution, adding a Tris buffer solution, adjusting the pH value to 8.5, adding dopamine, and stirring for a certain time to obtain a mixed solution;

and 3, carrying out vacuum filtration on the mixed solution obtained in the step 2 to form a film, and drying the obtained film at a certain temperature for a certain time to obtain the graphene oxide/nano-cellulose/polydopamine artificial pearl layer.

The preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material comprises the third step of soaking for 24 hours, drying at the temperature of 45-60 ℃ and drying for 24 hours.

The preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material comprises the step four, wherein the concentration of a copper nitrate solution is 0.02-0.05 mol/L, and the concentration of a sodium dihydrogen phosphate solution is 0.02-0.04 mol/L.

The preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material comprises the step four, wherein the soaking time is 12 hours, the drying temperature is 45-60 ℃, and the drying time is 24 hours.

The polydopamine-coated graphene oxide-based ternary artificial pearl layer material prepared by the preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material has the conductivity of 207.6S cm^-1。

The invention has the beneficial effects that:

according to the preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material, a copper nitrate solution is added in the preparation process, copper is used as a common metal, the copper has excellent electrical property, and the conductivity of the copper is as high as 5.7 multiplied by 10⁷S/m, second only to silver. However, since silver materials tend to be expensive, copper is often used in the industry for electrical devices. Copper nitrate [ Cu (NO)₃)₂]The copper nano-particles are easy to dissolve in water, and the aqueous solution of the copper nano-particles is reduced into the copper nano-particles on the surface of the copper nano-particles through secondary reaction of polydopamine, so that the electrical properties of the material can be obviously improved.

According to the preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material, the polydopamine can react with copper ions in a solution to form a polydopamine-copper ion chelating structure, and the special structure can enhance the tensile strength of the artificial pearl layer material. The mechanical test result shows that the tensile strength, Young modulus and toughness of the polydopamine coated graphene oxide-based ternary artificial pearl layer material can reach 544.8MPa, 9.7GPa and 5.9MJ m at most^-3. Besides, PDA can introduce multiple functional molecules to the surface of the material through secondary reaction, so that PDA is an excellent choice as a surface modifier.

According to the preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material, the cross section of the layered bionic material prepared by the invention shows a good layered structure through SEM observation, graphene oxide sheets are pulled out after stretching and breaking, and the sheets are bent.

According to the preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material, the polydopamine-coated graphene oxide-based ternary artificial pearl layer material is better in conductivity by further coating polydopamine and treating with a copper nitrate solution. EDS (electron-dispersive spectroscopy) spectrum proves that the surface of the material contains a large amount of copper nanoparticles; the electrical test result shows that when the addition of the nano-cellulose is 4.8 wt%, the conductivity of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material reaches 207.6S cm^-1Comparable to reduced graphene oxide (rGO).

The preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material disclosed by the invention is characterized in that the polydopamine-coated graphene oxide-based ternary artificial pearl layer material is constructed on the basis of the graphene oxide-based composite material, and the tensile strength of the original material is inherited and improved. In addition, the copper nanoparticles coated on the surface of the coating can obviously improve the electrical conductivity of the material.

The preparation method of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material is simple and convenient to operate, and the prepared polydopamine-coated graphene oxide-based ternary artificial pearl layer material serving as a novel bionic material has a wide application prospect in flexible energy equipment, supercapacitors and other electronic equipment.

Drawings

Fig. 1 is a process flow diagram of a preparation method of a polydopamine-coated graphene oxide-based ternary artificial pearl layer material according to the invention;

FIG. 2 is a 2000-fold SEM cross-sectional view of a polydopamine coated graphene oxide based ternary artificial pearl layer material with a nano-cellulose addition of 4.8 wt% prepared in example 7;

FIG. 3 is a 2000-fold SEM cross-sectional view of a polydopamine coated graphene oxide based ternary artificial pearl layer material with 9.5 wt% nanocellulose addition prepared in example 8;

FIG. 4 is a 2000-fold SEM cross-sectional view of a polydopamine coated graphene oxide based ternary artificial pearl layer material with 14.3 wt% nanocellulose addition prepared in example 9;

FIG. 5 is a 2000-fold SEM cross-sectional view of a polydopamine coated graphene oxide based ternary artificial pearl layer material with a 23.8 wt% nano-cellulose addition prepared in example 10;

FIG. 6 is a 5000-fold SEM side view of a fracture surface of a polydopamine coated graphene oxide based ternary artificial pearl layer material prepared in example 7 with a nano-cellulose addition of 4.8 wt%;

FIG. 7 is a 5000-fold SEM side view of a fracture surface of a polydopamine coated graphene oxide based ternary artificial pearl layer material prepared in example 8 with a 9.5 wt% nano-cellulose addition amount;

FIG. 8 is a 5000-fold SEM side view of a fracture surface of a polydopamine coated graphene oxide based ternary artificial pearl layer material prepared in example 9 with a nano-cellulose addition of 14.3 wt%;

FIG. 9 is a 10000-fold SEM side view of a fracture surface of a polydopamine coated graphene oxide based ternary artificial pearl layer material prepared in example 10, wherein the nano-cellulose addition amount of the polydopamine coated graphene oxide based ternary artificial pearl layer material is 23.8 wt%;

fig. 10 is an EDS spectrum of copper element on the surface of the polydopamine-coated graphene oxide-based ternary artificial pearl layer material prepared in example 7;

fig. 11 is a stress-strain tensile curve of polydopamine coated graphene oxide based ternary artificial pearl layer material prepared in example 8 at various nano-cellulose addition levels and an artificial pearl layer material of comparative example 1 that has not been treated with polydopamine and copper nitrate;

fig. 12 is tensile strength of polydopamine coated graphene oxide based ternary artificial pearl layer material prepared in examples 7-10 with different nano-cellulose addition amounts and the artificial pearl layer material of comparative example 2 with nano-cellulose addition amount of 0 wt%;

fig. 13 is a graph showing the toughness of the polydopamine coated graphene oxide-based ternary artificial pearl layer material prepared in examples 7 to 10 at different nano-cellulose addition amounts and the artificial pearl layer material prepared in comparative example 2 at a nano-cellulose addition amount of 0 wt%.

Detailed Description

The technical solutions of the present invention are further described below with reference to the following examples, but the present invention is not limited thereto, and any modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.