A method for preparing partially wrinkled graphene oxide

Abstract

The application provides a preparation method of partially wrinkled graphene oxide, which comprises the following steps: uniformly mixing graphene oxide with solvent water through ultrasonic mixing; obtaining micro droplets containing graphene oxide sheet layers by ultrasonic atomization of the mixed solution; bringing the graphene oxide micro droplets atomized through ultrasonic into a pulsed laser beam through high-speed airflow, generating ionization reaction between the laser and the micro droplets and emitting strong light; collecting the airflow carrying the graphene oxide micro droplets irradiated by the laser through suction filtration and removing the liquid solvent in the airflow; and finally obtaining partially wrinkled graphene oxide, the morphology of which is composed of sheet layers and wrinkles at the same time. The application prepares partially wrinkled graphene oxide which has sheet layer and wrinkle morphology at the same time, and the process is simple, rapid, and no toxic and harmful substances are discharged.

Description

Technical Field

[0001] This invention belongs to the field of chemical engineering and relates to a method for preparing graphene oxide, specifically a method for preparing partially wrinkled graphene oxide. Background Technology

[0002] Two-dimensional sheet graphene oxide exhibits van der Waals forces, which easily lead to sheet stacking problems, reducing its dispersibility in solution, decreasing its specific surface area, and limiting its superior performance and large-scale application. To solve the stacking problem of two-dimensional sheet graphene oxide, it can be transformed into three-dimensional wrinkled graphene oxide. The three-dimensional wrinkled structure reduces the van der Waals forces between particles, thereby improving its dispersibility. However, the preparation of three-dimensional wrinkled structures loses some of the properties of two-dimensional sheet structures, such as conformality. Three-dimensional wrinkled graphene oxide no longer possesses the conformality of two-dimensional sheet graphene oxide, making it difficult for particles to make conformal contacts with each other and with solid surfaces. This results in numerous contact gaps and a small effective contact area, leading to weak connectivity, poor adhesion, and low reliability, thus limiting the application of three-dimensional wrinkled structures in thin film technology, coating technology, and other fields. However, current preparation methods (such as atomized droplet evaporation) are difficult to achieve the composite of sheet and wrinkled graphene oxide structures, and other technologies (such as atomic force microscopy) are difficult to use for large-scale production of composite graphene oxide materials. Therefore, there is still a technological gap in the efficient preparation of wrinkled graphene oxide, which combines sheet-like and wrinkled structures. Summary of the Invention

[0003] To address the technological gap in preparing the aforementioned materials, this invention provides a method for preparing partially wrinkled graphene oxide. This method aims to efficiently prepare partially wrinkled graphene oxide particles that simultaneously possess both sheet-like and wrinkled morphologies, retaining the conformal capability of two-dimensional sheet-like morphology while also having the application value of three-dimensional wrinkled morphology.

[0004] To achieve the above objectives, the present invention provides a method for preparing partially wrinkled graphene oxide, comprising the following steps:

[0005] (1) Graphene oxide and solvent are ultrasonically mixed to obtain a graphene oxide solution.

[0006] (2) The graphene oxide solution was atomized by ultrasonication to obtain graphene oxide microdroplets;

[0007] (3) The graphene oxide microdroplets are carried into the pulsed laser beam by a high-speed gas: When the level is low, the pulsed laser beam does not emit light, and the graphene oxide microdroplets enter the area below the laser beam under the drive of the high-speed gas. When the level is high, the pulsed laser beam emits light, and the graphene oxide microdroplets below are irradiated by the laser and react with the laser.

[0008] (4) Because the micro-droplets have a curved gas-liquid interface, the laser beam that enters from the head of the micro-droplet will converge in a local area at the tail of the droplet. The energy density of the converged laser beam is increased, which triggers the ionization reaction of the material. The ionization reaction generates local high pressure, which partially wrinkles the graphene oxide in the micro-droplet, forming partially wrinkled graphene oxide. The morphology of a single particle of the partially wrinkled graphene oxide is composed of sheets and wrinkles at the same time.

[0009] (5) The laser-irradiated graphene oxide micro-droplet gas flow is collected by vacuum filtration and the liquid solvent in it is removed.

[0010] Furthermore, the solvent is water, and the concentration of the graphene oxide solution is any one of 0.01 g / L to 1 g / L.

[0011] Furthermore, the ultrasonic frequency is 10-30MHz, the ultrasonic power is 40-60W, the diameter of the graphene oxide microdroplets is less than 10μm, and the high-speed airflow velocity is 0.1m / s–10m / s.

[0012] Furthermore, the laser wavelength is 1064 nm, and the power density is 10-30 MW / cm². 2 The pulse duty cycle is 2%-20%.

[0013] Furthermore, the graphene oxide microdroplets will undergo an ionization reaction and generate intense light when irradiated by the laser beam.

[0014] Furthermore, the individual particle morphology of the partially wrinkled graphene consists of both sheets and wrinkles.

[0015] This invention utilizes the intermittent light emission characteristics of high-speed gas and pulsed laser to introduce tiny droplets into a laser beam. The high-energy-density laser beam irradiates ultrasonically atomized graphene oxide droplets. The reaction between the laser and the tiny droplets, and the localized ionization, provide the folding dynamics for the graphene oxide, thus producing partially wrinkled graphene oxide. Each individual particle simultaneously possesses both sheet-like and wrinkled morphologies.

[0016] Compared with existing technologies, the present invention represents a significant technological advancement. This invention utilizes the intermittent characteristics of high-speed gas and pulsed laser to achieve a continuous reaction between the laser and tiny droplets. It then uses the localized reaction between the laser and the tiny droplets to prepare partially wrinkled graphene oxide particles, simultaneously achieving sheet-like and wrinkled morphologies on a single particle. Furthermore, the process is simple, highly efficient, and produces no toxic or harmful emissions, making it environmentally friendly. Attached Figure Description

[0017] Figure 1The image shows the morphology of partially wrinkled graphene oxide prepared according to the method of the present invention.

[0018] Figure 2 This is a particle size distribution diagram of ultrasonically atomized graphene oxide microdroplets in the embodiment.

[0019] Figure 3 This is a schematic diagram of the ionization reaction and intense light generated between the laser and the tiny droplets in the embodiment. Detailed Implementation

[0020] To facilitate understanding of the technical means, creative features, objectives, and effects of this invention, the following embodiments, in conjunction with the accompanying drawings, specifically illustrate a method for preparing partially wrinkled graphene oxide according to this invention. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0021] A method for preparing partially wrinkled graphene oxide, comprising the following steps:

[0022] (1) Weigh 1g of graphene oxide and mix it with 1L of water by ultrasonication to obtain a graphene oxide solution with a concentration of 1g / L.

[0023] (2) 50 mL of a 1 g / L graphene oxide solution was atomized using ultrasound at a frequency of 17 MHz and a power of 50 W to obtain micro-droplets of graphene oxide. The particle size distribution is shown in the figure. Figure 2 As shown, the horizontal axis represents the diameter of the microdroplets, and the vertical axis represents the statistical number of microdroplets.

[0024] (3) Graphene oxide droplets were blown into a pulsed laser beam with a high-speed airflow of 1 m / s and a wavelength of 1064 nm and a power density of 16 MW / cm². 2 The focal spot diameter is 20μm, and the pulse duty cycle is 5%.

[0025] (4) Under the irradiation of the laser beam, the graphene oxide microdroplets will undergo an ionization reaction and produce strong light, such as... Figure 3 As shown in the figure, the bright spot is the intense light produced by the ionization reaction.

[0026] (5) The laser-irradiated graphene oxide microdroplet gas flow is collected by a filtration device. The filter membrane is a Teflon membrane with a pore size of 220 nm. The liquid solvent is removed by filtration, and the solid particles are collected to obtain partially wrinkled graphene oxide particles, the morphology of which is as follows. Figure 1 As shown, each individual particle exhibits both lamellar and folded morphologies.

[0027] This method uses the high-speed airflow and intermittent pulsed laser characteristics to introduce tiny droplets into a laser beam. The high-energy-density laser beam irradiates ultrasonically atomized graphene oxide droplets. The reaction between the laser and the tiny droplets and the local ionization generated provide the folding dynamics for the graphene oxide, thus producing partially wrinkled graphene oxide. Each particle simultaneously possesses sheet-like and wrinkled morphologies.

[0028] This method can simultaneously achieve lamellar and wrinkled morphologies on a single particle, and the process is simple, rapid, and environmentally friendly with no toxic or harmful emissions.

[0029] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing partially wrinkled graphene oxide, characterized in that... Includes the following steps: (1) Graphene oxide and solvent are ultrasonically mixed to obtain a graphene oxide solution; (2) The graphene oxide solution was atomized by ultrasonication to obtain graphene oxide microdroplets; (3) The graphene oxide microdroplets are driven into the pulsed laser beam by a high-speed airflow: When the laser is at a low level, the pulsed laser beam does not emit light, and the graphene oxide microdroplets are driven into the area below the laser beam by the high-speed airflow. When the laser is at a high level, the pulsed laser beam emits light, and the graphene oxide microdroplets below are irradiated by the laser and react with the laser. (4) Because the micro-droplets have a curved gas-liquid interface, the laser beam that enters from the head of the micro-droplet is focused on a local area at the tail of the droplet. The energy density of the focused laser beam is increased, which triggers the ionization reaction of the material. The ionization reaction generates local high pressure, which partially wrinkles the graphene oxide in the micro-droplet, forming partially wrinkled graphene oxide. The morphology of a single particle of the partially wrinkled graphene oxide is composed of sheets and wrinkles at the same time. (5) Collect the laser-irradiated graphene oxide micro-droplet gas flow by vacuum filtration and remove the liquid solvent in it.

2. The method for preparing partially wrinkled graphene oxide according to claim 1, characterized in that... The solvent is water, and the concentration of the graphene oxide solution is any one of 0.01 g / L to 1 g / L.

3. The method for preparing partially wrinkled graphene oxide according to claim 1, characterized in that... The ultrasonic frequency is 10-30 MHz, the ultrasonic power is 40-60 W, the diameter of the graphene oxide microdroplets is less than 10 μm, and the high-speed airflow velocity is 0.1 m / s – 10 m / s.

4. The method for preparing partially wrinkled graphene oxide according to claim 1, characterized in that... The laser wavelength is 1064 nm and the power density is 10-30 MW / cm². 2 The pulse duty cycle is 2%-20%.

5. The method for preparing partially wrinkled graphene oxide according to claim 1, characterized in that... The graphene oxide microdroplets undergo ionization and produce intense light when irradiated by the laser beam.

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