CN108486544B - Preparation method and application of graphene zinc oxide micro-nano grading functional material with self-cleaning and super-lyophobic characteristics - Google Patents

Abstract

The invention discloses a preparation method and application of a graphene zinc oxide micro-nano grading functional material with a self-cleaning and super-lyophobic property. The preparation method of the graphene zinc oxide micro-nano grading functional material comprises the following steps: s1: generating vertical graphene on a substrate; s2: dip-coating and adsorbing zinc oxide nano-particle seed crystals on the surface of the graphene by an atomic layer deposition method; s3: growing a zinc oxide nanowire on graphene by a hydrothermal method to form a graphene-zinc oxide micro-nano structure material; s4: and (3) carrying out modification treatment on the graphene-zinc oxide micro-nano structure material. Simultaneously, the application of the graphene zinc oxide micro-nano grading functional material is also disclosed. The graphene zinc oxide micro-nano grading functional material prepared by the invention has good performances of super-hydrophobicity, super-oleophobicity and super-blood-phobicity, and is a functional self-cleaning material. The material can be used as an electrode or a modified electrode, can be used as a sensor to detect substances, and has wide application prospect.

Description

A kind of graphene zinc oxide micro-nano graded functional material with self-cleaning super lyophobic properties Preparation method and application of material

technical field

The invention relates to a preparation method and application of a graphene zinc oxide micro-nano hierarchical functional material with self-cleaning super-lyophobic properties.

Background technique

Due to its unique liquid repellency, super lyophobic (both super hydrophobic, super oleophobic, and super hemophobic) materials are widely used in national defense, daily life, such as self-cleaning, anti-fouling and anti-corrosion, liquid transportation, drag reduction materials, and microfluidic control design. The field has broad application prospects. With the deepening of fundamental theoretical research on material surfaces and the rapid development of new fabrication techniques, the research on superlyophobic materials has received increasing attention. There are many examples of superhydrophobic surfaces in nature, such as lotus leaves that can roll off water droplets effortlessly. Undoubtedly, superhydrophobic biomimetic materials based on the "lotus leaf effect" have proven their wide application value in industrial applications such as coatings and films. The fluorine-containing multi-layered nano-silica spheres and carbon nanotubes are decorated on micron-scale carbon cloth, which can have stable superoleophobic properties for commonly used oils. The surface of fluorinated TiO2 nanotubes has good anti-platelet adhesion properties.

For rough surfaces, the wetting behavior can be theoretically described by two wetting models of the Wenzel and Cassie models. In the Wenzel state, since the liquid can completely penetrate into the microstructures of the rough surface, such as pores and concavities, the contact area between the liquid and the solid substrate can be increased, thereby amplifying the wetting or non-wetting properties of the solid material. At this time, the adhesion between the liquid and the solid is stronger. In the Cassie state, air is trapped on the rough surface below the liquid, forming a composite solid-liquid-air interface that supports the droplet, which results in a larger contact angle and a lower rolling angle for the droplet. Therefore, in order to make the surface of the material have super-lyophobic properties, the liquid should be in a stable Cassie state on the surface of the material. The Cassie model can be used to explain the wettability of lotus leaves. The current study reveals that the micro-nano hierarchical structure on the surface of lotus leaves plays a key role in its wettability. Through the biomimetic design of the lotus leaf surface, a superhydrophobic surface with a micro-nano hierarchical structure can be prepared. Generally, a lyophobic surface with a hierarchical structure can achieve liquid repellency through the synergistic effect of the design of surface roughness and the modification of solid surface with low surface energy.

Graphene materials have a wide range of applications due to their good electrical, optical, thermal, and mechanical properties, and graphene-based composite materials are a very important research direction in many graphene applications. Graphene and nano-metal oxides The composite preparation of lithium battery material enhances its conductivity and increases the specific surface area. The composite of graphene and conductive polymers or metal oxides to prepare supercapacitors, supercapacitors have the advantages of high energy density, short charge and discharge time, long cycle life, economical and environmental protection and so on.

The application of graphene in the direction of biosensors has been increasing in recent years. Biosensors are instruments that are sensitive to biological substances and use this sensitivity to detect them. Biosensors are classified into immunosensors, enzyme sensors, electrochemical DNA sensors, animal and plant tissue sensors, and microbial sensors according to the sensitive materials of biological materials. The cheapness, environmental friendliness, biocompatibility and uniform distribution of active groups of graphene, as well as a large number of carboxyl groups, hydroxyl groups and other functional groups, and good solubility make graphene an ideal biosensing material. Due to the introduction of the electrode modified by graphene composite material, the oxidation potential is greatly reduced, the sensitivity is improved, and the detection range is enlarged. In the detection of small biological molecules, the graphene composite material modified electrode can detect nicotinamide dinucleotide (NADH), dopamine (DA) is a catechol, paracetamol (APAP), anti-cyclohexemia More accurate detection of small biomolecules such as acid, uric acid, tyrosine and tryptophan. In the detection of biological macromolecules, it can be used as an immune biosensor to detect proteins, pathogens, bacteria, viruses and cells. At the same time, graphene also has broad applications in enzyme biosensors.

The unique two-dimensional structure, excellent mechanical properties, good optoelectronic properties, and large specific surface area of graphene materials have attracted the attention of scientists all over the world. It has shown excellent performance in the fields of energy storage, liquid crystal devices, electronic devices, biological materials, sensing materials and catalyst supports, and has broad application prospects. However, how to improve the dispersibility, compatibility, nanostructure and size control among the components of graphene-based composites, and the choice of solvents are worthy of continued research and discussion.

Since the biosensor is an instrument that uses the sensitivity of biological substances to detect it and can quickly track the detected biomolecules, the biosensor needs to have high selectivity, high sensitivity, fast analysis, low cost and miniaturization of the instrument, etc. Characteristics, graphene materials meet these conditions in all aspects, but because biosensors need to come into contact with various organic and inorganic liquids when detecting substances, it is inevitable that some water, dust, oil or dirt in the liquid to be detected will adhere. Contamination, once the biosensor is contaminated with these liquids, its detection performance will decline, and it cannot continue to be used as a biosensor, thus limiting the lifespan, stability, durability, and sensitivity of the biosensor. The reason for this is that the vertical graphene itself is superhydrophobic, but its adhesion to water is very strong. Even if the vertical graphene is reversed, the water droplets still stick to the surface of the vertical graphene. Generally speaking, the viscosity of the solid surface is related to the three-phase line (solid-liquid-gas) on the solid surface. The three-phase line is continuous, the viscosity is high, and the three-phase line is discontinuous, the adhesion is low. The three-phase lines of vertical graphene are continuous, so its adhesion is high. It is because the adhesiveness is too high that some liquids will contaminate the biosensor when used as a biosensor.

SUMMARY OF THE INVENTION

In order to overcome the defects and deficiencies that graphene materials are easily polluted when used as biological materials, sensors and catalyst carriers, the object of the present invention is to provide a kind of graphene zinc oxide micro-nano hierarchical functional material preparation with self-cleaning super lyophobic properties method and its application.

The technical scheme adopted by the present invention is:

A method for preparing a graphene zinc oxide micro-nano hierarchical functional material with self-cleaning super-lyophobic properties, comprising the following steps:

S1: generate vertical graphene on the substrate;

S2: Dip-coating and adsorbing zinc oxide nanoparticle seeds on the surface of graphene by atomic layer deposition;

S3: ZnO nanowires are grown on graphene by hydrothermal method to form graphene-ZnO micro-nanostructured materials;

S4: modifying the graphene-zinc oxide micro-nano structured material to obtain a graphene-zinc oxide micro-nano hierarchical functional material with self-cleaning super-lyophobic properties.

In step S1, the method for generating vertical graphene is plasma enhanced chemical vapor deposition method.

In step S1, the control conditions for the formation of vertical graphene by plasma enhanced chemical vapor deposition are: the substrate is a stainless steel substrate; the growth C source is CH ₄ and H ₂ ; the growth power is 800W-1200W; the growth temperature is 800°C-1000°C ; Growth time is 15min ~ 20min; cooling time is 20min ~ 40min.

In step S2, the precursors of the atomic layer deposition method are organic zinc compounds and water; the deposition temperature is 95°C to 105°C; each deposition time is 45s to 55s; and the number of cycles is 280 to 320 times.

In step S3, the hydrothermal method is specifically as follows: the graphene, water, zinc nitrate and hexamethylenetetramine adsorbed on the zinc oxide nanoparticle seed crystals are sealed and subjected to a hydrothermal synthesis reaction.

In step S3, the temperature of the hydrothermal reaction is 80°C to 100°C, and the reaction time is 80 min to 100 min.

In step S4, the modification treatment is specifically as follows: mixing the graphene-zinc oxide micro-nano structure material and the modifier, and reacting at a vacuum degree of 0.05MPa-0.1MPa for 10h-14h.

In step S4, the modifier used in the modification treatment is at least one of fluorine-containing compounds, carbon nanotubes, and organosilicon-modified acrylic resins.

The application of this graphene-zinc oxide micro-nano hierarchical functional material with self-cleaning super-lyophobic properties in the preparation of sensors.

The beneficial effects of the present invention are:

The invention prepares a graphene zinc oxide micro-nano graded functional material, the material has good properties of super-hydrophobicity, super-oleophobicity and super-hemophobicity, and is a functional self-cleaning material. Due to the high contact angle and low rolling angle of the superhydrophobic material, the droplets can roll freely on the surface, achieve their own self-cleaning effect through the action of water, and take away the dirt through the rolling of the water droplets. The graphene zinc oxide micro-nano hierarchical structure of the present invention can be used as an electrode or a modified electrode, and can be used as a sensor to detect some substances, such as hydrogen peroxide, glucose, urea, pH, amino acids, proteins, DNA and other various biomolecules, with broadly application foreground.

Description of drawings

Fig. 1 is the process schematic diagram that the present invention prepares graphene zinc oxide micro-nano graded functional material;

Fig. 2 is the scanning electron microscope picture of the graphene zinc oxide micro-nano graded functional material obtained in Example 1;

3 is an effect diagram of the graphene zinc oxide micro-nano graded functional material of the present invention when there are droplets on the surface.

Detailed ways

A method for preparing a graphene zinc oxide micro-nano hierarchical functional material with self-cleaning super-lyophobic properties, comprising the following steps:

S1: generate vertical graphene on the substrate;

S2: Dip-coating and adsorbing zinc oxide nanoparticle seeds on the surface of graphene by atomic layer deposition;

S3: ZnO nanowires are grown on graphene by hydrothermal method to form graphene-ZnO micro-nanostructured materials;

S4: modifying the graphene-zinc oxide micro-nano structured material to obtain a graphene-zinc oxide micro-nano hierarchical functional material with self-cleaning super-lyophobic properties.

Preferably, in step S1, the method for generating vertical graphene is plasma enhanced chemical vapor deposition method.

Preferably, in step S1, the control conditions for the formation of vertical graphene by plasma enhanced chemical vapor deposition are: the substrate is a stainless steel substrate; the growth C source is CH ₄ and H ₂ ; the growth power is 800W-1200W; the growth temperature is 800°C ～1000℃; the growth time is 15min～20min; the cooling time is 20min～40min.

Preferably, in step S2, the precursors of the atomic layer deposition method are organic zinc compounds and water; the deposition temperature is 95°C to 105°C; the deposition time is 45s to 55s; and the number of cycles is 280 to 320 times. ; Further preferably, in step S2, the organic zinc compound is diethyl zinc; the deposition temperature is 100 ° C; the time of each deposition is 50s; the number of cycles is 300 times.

Preferably, in step S3, the hydrothermal method is specifically as follows: the graphene, water, zinc nitrate and hexamethylenetetramine (HTMA) adsorbed on the zinc oxide nanoparticle seeds are sealed and subjected to a hydrothermal synthesis reaction.

Preferably, in step S3, the concentration of zinc nitrate is 0.2mol/L～0.3mol/L; the concentration of hexamethylenetetramine is 0.2mol/L～0.3mol/L.

Preferably, in step S3, the temperature of the hydrothermal reaction is 80°C to 100°C, and the reaction time is 80 min to 100 min.

Preferably, in step S4, the modification treatment is specifically: mixing the graphene-zinc oxide micro-nano structure material with a modifier, and reacting for 10h-14h under a vacuum degree of 0.05MPa-0.1MPa.

Preferably, in step S4, the modifier used in the modification treatment is at least one of fluorine-containing compounds, carbon nanotubes, and organosilicon modified acrylic resin; further preferably, in step S4, the modifier used in the modification treatment The modifier is a fluorine-containing compound; further preferably, in step S4, the modifier used in the modification treatment is 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane.

Further, in step S4, when the modifier used is a fluorine-containing compound, the modification treatment is fluorination treatment; specifically, the fluorination treatment is vacuum gas phase fluorination.

The schematic diagram of the preparation process of the graphene zinc oxide micro-nano hierarchical functional material of the present invention can be seen in accompanying drawing 1. FIG. 1 only shows an example of the preparation method, and the method of the present invention is not limited to the related substances shown in the figure.

The application of this graphene-zinc oxide micro-nano hierarchical functional material with self-cleaning super-lyophobic properties in the preparation of sensors.

Preferably, in the application, the sensor is an electrochemical sensor and/or a biosensor; the biosensor may be a field effect transistor biosensor or an optical biosensor.

Further, the graphene zinc oxide micro-nano-graded functional material with self-cleaning super-lyophobic properties can be used to modify electrodes or directly prepare electrodes, which can be used for glucose, urea, pH, amino acid, protein, DNA, hydrogen peroxide, etc. Biosensors for the detection of a wide variety of biomolecules.

The graphene zinc oxide micro-nano graded functional material prepared by the invention is a functional material with self-cleaning, which can well protect the biosensor and prevent it from being affected by various complex molecules in biological tissue fluid or biological samples, such as proteins and polypeptides. , small molecules, etc., so that it can not be contaminated by biological tissue fluid or biological samples, can prolong its service life, durability and maintain its sensitivity and stability. In addition, the graphene zinc oxide micro-nano graded functional material prepared by the present invention can also be used as an electrode of an electrochemical sensor to detect H ₂ O ₂ , H ₂ S, NO, ascorbic acid, etc.; as a field effect transistor biosensor to detect pH; Taking advantage of the fluorescence quenching properties of graphene in DNA biosensing, an optical biosensor can also be made to detect DNA.

The inventive idea of the present invention is further described below as follows:

In the present invention, the flake graphene with vertical orientation is manufactured by using plasma enhanced chemical vapor deposition method (PECVD), and the density of graphene growth is controlled by changing the temperature, power and time, and the vertically oriented graphene can be controllably prepared. The graphene zinc oxide micro-nano hierarchical structure is prepared by a series of steps such as atomic deposition method and hydrothermal method. The hydrothermal method controls the growth length and diameter of zinc oxide nanowires by controlling the concentration of growth reagents, growth temperature, time, and growth times. . Due to the distribution of zinc oxide nanowires in graphene zinc oxide micro-nano hierarchical structure, the air is trapped on the rough surface below the liquid when it contacts the droplet, forming a composite solid-liquid-gas interface that can support the droplet. The surface of the material is in a stable Cassie state, which makes the droplet have a large contact angle and a low rolling angle. By fluorination treatment, the surface energy of the material surface can be further reduced, so that the lyophobicity of the material can be improved. In terms of hydrophobic and oleophobic properties, it has superhydrophobicity and superoleophobicity, and water droplets or oil droplets can easily slide off the functional surface. In terms of hemophobicity, the anti-platelet adhesion experiment can show that the functional surface of graphene zinc oxide micro-nano hierarchical structure can make the blood slide off easily, and achieve the effect of super hemophobicity.

Graphene zinc oxide micro-nano hierarchical structure material, can obtain excellent waterproof, anti-blood and oil-proof properties, providing a method to create graphene zinc oxide micro-nano hierarchical structure with self-cleaning properties, which is useful for protection as electrodes and other applications It is very important for graphene to be free from contamination. As a detection sensor, the graphene zinc oxide micro-nano hierarchical structure is used as an electrode or a modified electrode, which can be used as a sensor to detect some substances, such as hydrogen peroxide, glucose, urea, pH, amino acids, proteins, DNA and other various biological molecular.

The content of the present invention will be described in further detail below through specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field.

Example 1:

1. Preparation method

The preparation of the graphene zinc oxide micro-nano graded functional material with self-cleaning super-lyophobic properties of embodiment 1 comprises the following steps:

S1. Growth of vertical graphene

(1) Clean the stainless steel substrate with deionized water and ethanol, and then dehumidify with nitrogen;

(2) Discharge the stainless steel substrate on the inner substrate of the PECVD chamber and vacuumize; control the PECVD power to be 1200W, the growth temperature to be 900°C, the growth C source to be CH ₄ and H ₂ , the growth time to be 15 minutes, and the cooling time to be time 30 minutes, after the growth is completed, the furnace is released to obtain vertical graphene;

S2. Dip-coat and adsorb zinc oxide nanoparticle seed crystals on the graphene surface in step 1 by atomic layer deposition

Arrange the samples in step S1 into the chamber of the ALD instrument, control the temperature to 100 °C, the precursors are diethylzinc and oxygen, the oxygen source is water, the time is 50s, and the surface of the sample is rinsed with argon, and repeated 300 times Cycle, dip-coat and adsorb zinc oxide nanoparticle seeds on the graphene surface, so that the next step can grow zinc oxide nanowires on the graphene surface;

S3. Hydrothermal synthesis method to grow ZnO nanowires on graphene

First, configure the reagents required for growth: 0.25mol/L zinc nitrate hexahydrate and 0.25mol/L HTMA (hexamethylenetetramine); then invert the graphene substrate that adsorbs the zinc oxide nanoparticle seeds in step 2 into an appropriate volume Add 4 mL of deionized water, 0.5 mL of zinc nitrate and 0.5 mL of HTMA to a beaker of the same size, seal it with plastic wrap, place it in a drying box at 90°C, and grow it hydrothermally for 90 minutes. After the growth, take it out and rinse it with deionized water. excess ZnO. Repeat the above steps, so that the inter-sheet channels of the sheet graphene are filled with zinc oxide nanowires to form secondary zinc oxide nanowire branches, that is, the graphene zinc oxide micro-nano graded functional material is prepared;

S4. Fluorination of Graphene ZnO Micro/Nano Hierarchical Functional Materials

Vacuum gas phase fluorination fluorination: take the graphene zinc oxide micro/nano graded functional material prepared in step 3 and place it in a vacuum desiccator, add 100 μL of 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane, Vacuuming, the vacuum degree reached 0.08MPa, the vacuuming was 2min, and the fluorination time was about 12 hours. After the fluorination was completed, the sample was rinsed with acetone or ethanol to remove redundant fluorination reagents to obtain the graphene zinc oxide microparticles of Example 1. Nanoscale functional materials.

2. Performance test

The graphene zinc oxide micro-nano graded functional material prepared in Example 1 was characterized and analyzed, and its SEM image was shown in Figure 2.

Hydrophobicity, oleophobicity and hemophobicity were tested by the graphene zinc oxide micro/nano graded functional material prepared in Example 1:

(1) Hydrophobicity test

A drop of water (4 microliters) was dropped on the surface of the graphene zinc oxide micro-nano graded material by a contact angle measuring instrument, and the movement of the water drop was observed. The results are shown in Figure 3, the droplets were dropped on the functionally wetted surface of the graphene zinc oxide micro/nano hierarchical structure, and due to the low surface energy of the sample after fluorination, the droplets formed on the functionally wetted surface greater than 150°. The contact angle and the hysteresis angle are very small, the droplets slide freely on the surface of the graphene zinc oxide micro-nano hierarchical structure material, and have hydrophobicity and self-cleaning properties.

(2) Oleophobicity test

Same as step (1), replace the water droplets with oil droplets. The results show that oil droplets slide freely on the liquid surface of graphene zinc oxide micro-nano hierarchical structure material, and have oleophobicity.

(3) Hemophobicity test

Same as step (1), replace the water droplets with blood droplets. The results show that the blood droplets slide freely on the surface of the graphene zinc oxide micro-nano hierarchical structure material liquid, achieving the effect of super hemophobicity.

Example 2:

1. Preparation method

The preparation of the graphene zinc oxide micro-nano graded functional material with self-cleaning super-lyophobic properties of embodiment 2 comprises the following steps:

S1. Growth of vertical graphene

(1) Clean the stainless steel substrate with deionized water and ethanol, and then dehumidify with nitrogen;

(2) Discharge the stainless steel substrate on the inner substrate of the PECVD chamber and vacuumize; control the PECVD power to 1000W, the growth temperature to 800°C, the growth C source to be CH ₄ and H ₂ , the growth time to be 20 minutes, and the cooling time to be time 30 minutes, after the growth is completed, the furnace is released to obtain vertical graphene;

S2. Dip-coat and adsorb zinc oxide nanoparticle seed crystals on the graphene surface in step 1 by atomic layer deposition

Same as Example 1;

S3. Hydrothermal synthesis method to grow ZnO nanowires on graphene

First, configure the reagents required for growth: 0.25mol/L zinc nitrate hexahydrate and 0.25mol/L HTMA (hexamethylenetetramine); then invert the graphene substrate that adsorbs the zinc oxide nanoparticle seeds in step 2 into an appropriate volume Add 4 mL of deionized water, 0.5 mL of zinc nitrate and 0.5 mL of HTMA to a beaker of the same size, seal it with plastic wrap, place it in a drying box at 80°C, and grow it hydrothermally for 100 minutes. After the growth, take it out and rinse it with deionized water. excess ZnO. Repeat the above steps, so that the inter-sheet channels of the sheet graphene are filled with zinc oxide nanowires to form secondary zinc oxide nanowire branches, that is, the graphene zinc oxide micro-nano graded functional material is prepared;

S4. Fluorination of Graphene ZnO Micro/Nano Hierarchical Functional Materials

Vacuum gas phase fluorination fluorination: take the graphene zinc oxide micro/nano graded functional material prepared in step 3 and place it in a vacuum desiccator, add 100 μL of 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane, Vacuuming, the vacuum degree reached 0.08MPa, the vacuuming was 2min, and the fluorination time was about 14 hours. After the fluorination was completed, the sample was rinsed with acetone or ethanol to remove the excess fluorination reagent to obtain the graphene zinc oxide microparticles of Example 2. Nanoscale functional materials.

2. Performance test

Hydrophobicity, oleophobicity and hemophobicity were tested for the graphene zinc oxide micro/nano graded functional material prepared in Example 2; the results showed that the graphene zinc oxide micro/nano graded functional material of Example 2 had superhydrophobicity, Oil, good superhemophobic properties, with self-cleaning superlyophobic properties.

Example 3:

1. Preparation method

The preparation of the graphene zinc oxide micro-nano graded functional material with self-cleaning super-lyophobic properties of embodiment 3 comprises the following steps:

S1. Growth of vertical graphene

(1) Clean the stainless steel substrate with deionized water and ethanol, and then dehumidify with nitrogen;

(2) Discharge the stainless steel substrate on the inner substrate of the PECVD chamber, and vacuumize; control the PECVD power to be 800W, the growth temperature to be 1000°C, the growth C sources to be CH ₄ and H ₂ , the growth time to be 18 minutes, and the cooling time to be time 30 minutes, after the growth is completed, the furnace is released to obtain vertical graphene;

S2. Dip-coat and adsorb zinc oxide nanoparticle seed crystals on the graphene surface in step 1 by atomic layer deposition

Same as Example 1;

S3. Hydrothermal synthesis method to grow ZnO nanowires on graphene

First, configure the reagents required for growth: 0.25mol/L zinc nitrate hexahydrate and 0.25mol/L HTMA (hexamethylenetetramine); then invert the graphene substrate that adsorbs the zinc oxide nanoparticle seeds in step 2 into an appropriate volume Add 4 mL of deionized water, 0.5 mL of zinc nitrate and 0.5 mL of HTMA to a beaker of the same size, seal it with plastic wrap, place it in a drying box at 100°C, and grow it hydrothermally for 80 minutes. After the growth, take it out and rinse it with deionized water. excess ZnO. Repeat the above steps, so that the inter-sheet channels of the sheet graphene are filled with zinc oxide nanowires to form secondary zinc oxide nanowire branches, that is, the graphene zinc oxide micro-nano graded functional material is prepared;

S4. Fluorination of Graphene ZnO Micro/Nano Hierarchical Functional Materials

Vacuum gas phase fluorination fluorination: take the graphene zinc oxide micro/nano graded functional material prepared in step 3 and place it in a vacuum desiccator, add 100 μL of 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane, Vacuuming, the vacuum degree reaches 0.08MPa, vacuuming for 2min, and the fluorination time is about 10 hours. After the fluorination is completed, the sample is rinsed with acetone or ethanol to remove excess fluorination reagent to obtain the graphene zinc oxide microparticles of Example 3. Nanoscale functional materials.

2. Performance test

The graphene zinc oxide micro/nano graded functional material prepared in Example 3 was tested for hydrophobicity, oleophobicity and hemophobicity; the results showed that the graphene zinc oxide micro/nano graded functional material of Example 3 had superhydrophobicity, superoleophobicity , Good performance of super hemophobic, with self-cleaning super lyophobic properties.

Comparative Example 1:

1. Preparation method

The preparation of the graphene zinc oxide micro-nano graded functional material of Comparative Example 1 comprises the following steps:

S1. Growth of vertical graphene

Same as Example 1;

S2. Dip-coating and adsorbing zinc oxide nanoparticle seeds on graphene surface

The vertical graphene sample of step 1 was lightly dipped in methanol solution of 0.005mol/L zinc acetate, evaporated to dryness at 60°C for several times, and then reacted in a vacuum state of 300°C, and the graphene surface was plated with seeds;

S3. Hydrothermal synthesis method to grow ZnO nanowires on graphene

Same as Example 1;

S4. Fluorination of Graphene ZnO Micro/Nano Hierarchical Functional Materials

Similar to Example 1, the graphene zinc oxide micro-nano graded functional material of Comparative Example 1 was prepared.

2. Performance test

The distribution of the obtained crystal seeds prepared through above-mentioned steps 2 is not uniform, so that the oxidized nanowires of subsequent growth are not uniform enough, and the hydrophobicity, oleophobicity and hemophobicity of the prepared graphene zinc oxide micro-nano graded functional material are all poor ( Wet, will not slip), can not be used in practice.

In summary:

In the preparation of the graphene zinc oxide micro-nano composite structure of the present invention, the graphene is grown by a plasma-enhanced chemical vapor deposition method, and the growth density length of the graphene is controlled by controlling the temperature, power, time and other conditions. Dip-coating and adsorbing zinc oxide nanoparticle seeds on the surface of graphene, and adopting a hydrothermal method to prepare step by step to ensure that the microstructure is controllably added in stages. Low surface energy fluorine-containing compounds are surface modified to impart hydrophobic, oleophobic, hemophobic or lyophobic properties. The principle of superhydrophobic self-cleaning material is to achieve its own self-cleaning effect through the action of water. Due to the high contact angle and low rolling angle of superhydrophobic material, water droplets can roll freely on the surface, so the dirt can be taken away by the rolling of water droplets. .

Since the prepared graphene zinc oxide micro-nano graded functional material is a self-cleaning functional material, it can well protect the biosensor and prevent it from being affected by various complex molecules in biological tissue fluid or biological samples, such as proteins, peptides, The adhesion of small molecules, etc., makes it free from contamination by biological tissue fluids or biological samples, which can prolong its service life, durability and maintain its sensitivity and stability.

Claims (2)

1. a preparation method of the graphene zinc oxide micro-nano graded functional material with self-cleaning super-lyophobic properties, is characterized in that: Include the following steps: S1: generate vertical graphene on the substrate; S2: Dip-coating and adsorbing zinc oxide nanoparticle seeds on the surface of graphene by atomic layer deposition; S3: ZnO nanowires are grown on graphene by hydrothermal method to form graphene-ZnO micro-nanostructured materials; S4: modifying the graphene-zinc oxide micro-nano structure material to obtain a graphene-zinc oxide micro-nano hierarchical functional material with self-cleaning super-lyophobic properties; In step S1, the method for generating vertical graphene is plasma enhanced chemical vapor deposition method; In step S1, the control conditions for the formation of vertical graphene by plasma enhanced chemical vapor deposition are: the substrate is a stainless steel substrate; the growth C source is CH ₄ and H ₂ ; the growth power is 800W-1200W; the growth temperature is 800°C-1000°C ; The growth time is 15min～20min; The cooling time is 20min～40min; In step S2, the precursors of the atomic layer deposition method are organic zinc compounds and water; the deposition temperature is 95°C to 105°C; the deposition time is 45s to 55s; the number of cycles is 280 to 320 times; In step S3, the hydrothermal method is specifically as follows: the graphene, water, zinc nitrate and hexamethylenetetramine adsorbed on the zinc oxide nanoparticle seeds are sealed and subjected to a hydrothermal synthesis reaction; In step S3, the temperature of the hydrothermal reaction is 80°C～100°C, and the reaction time is 80min～100min; In step S4, the modification treatment is specifically: mixing the graphene-zinc oxide micro-nano structure material and the modifier, and reacting for 10h-14h under a vacuum degree of 0.05MPa-0.1MPa; In step S4, the modifier used in the modification treatment is at least one of fluorine-containing compounds, carbon nanotubes, and organosilicon-modified acrylic resins. 2. the application of the graphene zinc oxide micro-nano graded functional material prepared by claim 1 in the preparation of biosensors.

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