CN109859999B - Method for preparing transmission electron microscope carrier net by LB membrane method - Google Patents
Method for preparing transmission electron microscope carrier net by LB membrane method Download PDFInfo
- Publication number
- CN109859999B CN109859999B CN201910082790.5A CN201910082790A CN109859999B CN 109859999 B CN109859999 B CN 109859999B CN 201910082790 A CN201910082790 A CN 201910082790A CN 109859999 B CN109859999 B CN 109859999B
- Authority
- CN
- China
- Prior art keywords
- graphene
- electron microscope
- transmission electron
- film
- solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Carbon And Carbon Compounds (AREA)
Abstract
The invention provides a transmission electron microscope carrier net prepared by an LB membrane method. The method comprises the steps of preparing a carboxylated graphene film in a liquid level self-assembly mode by an LB (Lub film) membrane method, fixing a transmission electron microscope copper carrying net on a hollowed-out smooth and conductive support network or support, slowly lifting, enabling the support network or support to be at a positive potential when the transmission electron microscope copper carrying net is close to the liquid level, attaching a single-layer graphene film to the surface of the transmission electron microscope copper carrying net, and reducing the carboxylated graphene into graphene. The graphene film prepared by the method can be controlled to be in the thickness of the monoatomic layer, is easy to operate, avoids the problem of inconsistent thickness of the film prepared by a solution casting method, can regulate the thickness of the graphene layer, guarantees high contrast and high resolution of a transmission electron microscope carrier, simultaneously considers the strength, ensures that the graphene film cannot crack when a sample is loaded, has simple preparation process and lower requirement on equipment, is suitable for industrial or laboratory operation, and has huge application prospect.
Description
Technical Field
The invention relates to the technical field of transmission electron microscope preparation, in particular to a method for preparing a transmission electron microscope carrier net by using an LB membrane method.
Background
Transmission electron microscopy has become an indispensable detection means in the fields of material science, life science, and the like. The carrier net film is one of the most commonly used consumables of a transmission electron microscope, and mainly plays a role in loading a small-scale sample during electron microscope observation. At present, the most common copper-based grid is loaded with a supporting film, which mainly comprises a carbon supporting film, a micro-grid, an ultrathin carbon film, a pure carbon film and the like. The carbon film can improve the conductivity of the supporting film, eliminate charge accumulation caused by electron beam irradiation, and reduce the influence of sample drift, jump, even supporting film crack and the like on the detection result. The thinner the thickness of the carbon film is, the higher the contrast of the carbon film is, and the higher the resolution is; however, too thin a carbon film results in low mechanical strength. The existing carbon support film has complex preparation process and thicker thickness, and can not meet the requirement of contrast for part of samples.
The graphene is only 0.34nm in thickness, high in mechanical strength, good in conductivity, high-temperature resistant, corrosion resistant, electron beam bombardment resistant, low in contrast, easy to modify and produce in a large scale, and the contrast and the stability of a sample during observation can be remarkably improved by applying the film. At present, the preparation method for introducing graphene into a grid of a transmission electron microscope mainly comprises the steps of preparing a copper-based graphene film by a chemical vapor deposition method, etching a copper base by using a ferric trichloride solution, and paving the graphene film on a microporous array carbon support film, wherein the graphene film prepared by the method has low coverage rate and complex method; in another method, a single-layer graphene oxide film-micro grid composite film is prepared from an aqueous solution of graphene oxide nanosheets and a porous micro grid support film by a solution casting method and is used as a transmission electron microscope grid support film.
The Langmuir-Blodgett film (LB film for short) method is a technology for constructing an organic ordered ultrathin molecular film established by American scientists I.Langmuir and students K.Blodgett in the second thirty years of the 20 th century. The technology is simple and convenient, and can control the orderliness, thickness and uniformity of the membrane at the molecular level, so that the technology is concerned by researchers at home and abroad. The LB film technology is expected to improve the defects of the current graphene transmission electron microscope grid carrying technology.
Disclosure of Invention
The invention uses LB film method to prepare the transmission electron microscope carrier net. Firstly, preparing a carboxylated graphene material, and preparing a single-layer graphene film by self-assembly on a gas-liquid interface by using an LB (Langmuir-Blodgett) membrane method; then, fixing a plurality of transmission electron microscope copper carrying nets without supporting films on a hollow smooth and conductive supporting net or bracket, wherein the whole transmission electron microscope copper carrying nets are arranged below the liquid level and can allow the solution to smoothly pass through; secondly, slowly lifting the support network or the bracket, enabling the support network or the bracket to be at a positive potential when the support network or the bracket is close to a liquid surface, and attaching the single-layer graphene film to the surface of the transmission electron microscope copper grid; and finally, reducing the carboxylated graphene on the transmission electron microscope copper-carried net to enhance the conductivity of the transmission electron microscope copper-carried net, and repeating the process for multiple times to control the thickness of the graphene supporting film.
The invention adopts the following technical scheme:
the LB film method for preparing the transmission electron microscope carrier net comprises the following steps:
(1) taking a graphite intercalation compound as a raw material, carrying out oxidation-reduction reaction on an intercalation agent of the graphite intercalation compound and a reactant in a solution to prepare high-quality graphene, and oxidizing the high-quality graphene by adopting sodium chlorate, concentrated sulfuric acid and hydrogen peroxide to obtain a carboxylated graphene material;
(2) dropwise adding the carboxylated graphene aqueous solution on a water surface by adopting a Langmuir-Blodgett method to form a graphene oxide film on a water-air interface;
(3) fixing a plurality of transmission electron microscope copper carrying nets without supporting films on a hollow smooth and conductive supporting network or bracket, wherein the whole transmission electron microscope copper carrying nets are arranged below the liquid level and can allow a solution to smoothly pass through;
(4) slowly lifting the support network or the bracket, keeping the support network or the bracket at a positive potential when the support network or the bracket is close to a liquid surface, and attaching the single-layer graphene film to the surface of the transmission electron microscope copper grid:
(5) the carboxylated graphene on the copper-supported mesh of the transmission electron microscope is reduced, so that the conductivity of the graphene supporting film is enhanced, and the thickness of the graphene supporting film can be controlled by repeating the process for many times.
The intercalation agent of the graphite intercalation compound in the step (1) is metal or metal halide, specifically potassium, sodium, lithium, potassium-sodium alloy, iodine chloride, aluminum chloride, nickel chloride, antimony chloride, ferric chloride or antimony fluoride, substances which can react with the intercalation agent between graphite sheets are added into the solution and comprise ethanol, sodium borohydride solution, hydrazine hydrate solution and hydrogen peroxide solution, the mass solubility of the hydrogen peroxide is 30%, the mass ratio of the hydrazine hydrate is 30%, and the sodium borohydride solution needs to be prepared into alkaline solution with the pH of 13.
In the step (1), the mass ratio of sodium chlorate to graphene is 0.5-6, the oxidation time is 0.5-8 h, the temperature is 0-20 ℃, and the oxygen content in the carboxylated graphene accounts for less than 30% of the total mass of carbon and oxygen elements.
The concentration of the carboxylated graphene aqueous solution in the step (2) is 0.02-5 mg/mL.
The transmission electron microscope copper carrying nets without the supporting film in the step (3) cannot be mutually overlapped, and a space should be reserved between the electron microscope copper carrying nets.
In the step (4), the speed of lifting the support network or the support is required to be controlled so as to avoid damaging the film structure too fast, and the positive potential is set to be 1-10V.
The reduction method in the step (5) comprises thermal reduction, chemical reduction and photoreduction.
The invention has the following advantages:
(1) the invention utilizes Langmuir-Blodgett assembly technology to prepare the single-layer graphene film in a self-assembly manner at a gas-liquid interface, the thickness of the film can be controlled to be equal to the thickness of a monoatomic layer, the uniformity is good, and the area can be freely regulated and controlled.
(2) According to the method, the traditional transfer step is omitted by lifting the support network or the support, the single-layer graphene film is firmly attached to the surface of the transmission electron microscope copper grid by loading a positive potential, the single-molecule film is prevented from being damaged, the operation is easy, the problem that the film thickness is different when the film is prepared by a solution casting method is avoided, the graphene film with accurate layers can be prepared in batches, the thickness of the graphene layer can be regulated, the high contrast and high resolution of the transmission electron microscope copper grid are ensured, the strength is considered, and the graphene film is prevented from being broken when a sample is loaded.
(3) The electric conductivity of the carboxylated graphene is greatly improved after reduction, and the carboxylated graphene can be used as a substrate of a positive potential to adsorb the interface carboxylated graphene when a multilayer graphene support film is prepared, so that a monomolecular film is prevented from being damaged.
(4) The method has simple preparation process and low requirement on equipment, is suitable for industrial or laboratory operation, and has huge application prospect.
Drawings
FIG. 1 is a schematic diagram of a process for preparing a transmission electron microscope grid by the method of the present invention, wherein the size ratio of each part is different from the actual situation.
FIG. 2 is a transmission electron microscope image of a multilayer graphene support film prepared by the method of the present invention.
FIG. 3 is an electron diffraction pattern of a multilayer graphene support film prepared by the method of the present invention.
Detailed Description
For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the purpose of facilitating understanding of the present invention and should not be construed as specifically limiting the present invention.
Example 1
(1) 0.3g of anhydrous FeCl3Mixing with 0.05g of expanded graphite, sealing in a vacuum ampoule with the specification of 20mL in vacuum, heating to 380 ℃ for 1h, and maintaining for 12 h. Dissolving the black product in dilute hydrochloric acid solution, filtering and drying for later use.
(2) Taking out the intercalation compound, dispersing the intercalation compound into 50mL of organic solvent N-methyl pyrrolidone to prepare 5mg/mL suspension, adding 10mL of sodium borohydride alkaline aqueous solution into a container, carrying out ultrasonic reaction for 1h to obtain a graphene material, and cleaning for later use.
(3) 20mL of H2SO4The temperature was maintained in ice water (0 ℃) for 0.5h, and 30mg of the original graphene material was added to concentrated sulfuric acid and stirred for 10 min.
(4) 120mg of sodium chlorate and 0.1mL of H with the mass fraction of 30 percent2O2And (3) putting the solution into concentrated sulfuric acid and graphene solution, stirring for 4 hours at room temperature, repeatedly centrifuging and washing the product, and performing ultrasonic treatment to obtain the carboxylated graphene solution dispersed in water.
(5) Preparing 1mg/mL carboxylated graphene aqueous solution, and dropwise adding the carboxylated graphene aqueous solution on the water surface to form a graphene oxide film on a water-air interface.
(6) 80 transmission electron microscope copper carrying nets without supporting films are placed on a hollowed-out flat screen, and the whole is placed below the liquid level.
(7) And slowly lifting the support network or the bracket, keeping the support network or the bracket at a positive potential of 3V when the support network or the bracket is close to the liquid surface, and attaching the single-layer graphene film to the surface of the transmission electron microscope copper grid.
(8) And (3) placing the carrier net in a reducing atmosphere consisting of 3% of hydrogen and 97% of argon, and heating and reducing for 60min at 800 ℃ to obtain the graphene film.
Example 2
(1) 0.3g of anhydrous FeCl3Mixing with 0.05g of expanded graphite, sealing in a vacuum ampoule with the specification of 20mL in vacuum, heating to 380 ℃ for 1h, and maintaining for 12 h. Dissolving the black product in dilute hydrochloric acid solution, filtering, and dryingThe application is as follows.
(2) Taking out the intercalation compound, dispersing the intercalation compound into 50mL of organic solvent N-methyl pyrrolidone to prepare 5mg/mL suspension, adding 10mL of sodium borohydride alkaline aqueous solution into a container, carrying out ultrasonic reaction for 1h to obtain a graphene material, and cleaning for later use.
(3) 20mL of H2SO4The temperature was maintained in ice water (0 ℃) for 0.5h, and 30mg of the original graphene material was added to concentrated sulfuric acid and stirred for 10 min.
(4) 120mg of sodium chlorate and 0.1mL of H with the mass fraction of 30 percent2O2And (3) putting the solution into concentrated sulfuric acid and graphene solution, stirring for 4 hours at room temperature, repeatedly centrifuging and washing the product, and performing ultrasonic treatment to obtain the carboxylated graphene solution dispersed in water.
(5) Preparing 1mg/mL carboxylated graphene aqueous solution, and dropwise adding the carboxylated graphene aqueous solution on the water surface to form a graphene oxide film on a water-air interface.
(6) 80 transmission electron microscope copper carrying nets without supporting films are placed on a hollowed-out flat screen, and the whole is placed below the liquid level.
(7) And slowly lifting the support network or the bracket, keeping the support network or the bracket at a positive potential of 3V when the support network or the bracket is close to the liquid surface, and attaching the single-layer graphene film to the surface of the transmission electron microscope copper grid.
(8) And (3) placing the carrier net in a reducing atmosphere consisting of 3% of hydrogen and 97% of argon, and heating and reducing for 60min at 800 ℃ to obtain the graphene film.
(9) Repeating the steps for 4 times to obtain the multilayer graphene supporting film.
The applicant states that the present invention is illustrated by the above examples to show the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above detailed process equipment and process flow, i.e. it does not mean that the present invention must rely on the above detailed process equipment and process flow to be implemented. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
Claims (7)
- A method for preparing a transmission electron microscope grid by an LB membrane method comprises the following steps:(1) taking a graphite intercalation compound as a raw material, carrying out oxidation-reduction reaction on an intercalation agent of the graphite intercalation compound and a reactant in a solution to prepare high-quality graphene, and oxidizing the high-quality graphene by adopting sodium chlorate, concentrated sulfuric acid and hydrogen peroxide to obtain a carboxylated graphene material;(2) dropwise adding the carboxylated graphene aqueous solution on a water surface by adopting a Langmuir-Blodgett method to form a graphene oxide film on a water-air interface;(3) fixing a plurality of transmission electron microscope copper carrying nets without supporting films on a hollow smooth and conductive supporting network or bracket, wherein the whole transmission electron microscope copper carrying nets are arranged below the liquid level and can allow a solution to smoothly pass through;(4) slowly lifting the support network or the bracket, enabling the support network or the bracket to be at a positive potential when the support network or the bracket is close to a liquid surface, and attaching the single-layer graphene oxide film to the surface of the transmission electron microscope copper grid;(5) the carboxylated graphene on the copper-supported mesh of the transmission electron microscope is reduced, so that the conductivity of the graphene supporting film is enhanced, and the thickness of the graphene supporting film can be controlled by repeating the process for many times.
- 2. The method according to claim 1, wherein the intercalation agent of the graphite intercalation compound in step (1) is a metal or metal halide, specifically potassium, sodium, lithium, potassium-sodium alloy, iodine chloride, aluminum chloride, nickel chloride, antimony chloride, ferric chloride or antimony fluoride, and the substance capable of reacting with the intercalation agent between graphite sheets is added to the solution and comprises ethanol, sodium borohydride solution, hydrazine hydrate solution or hydrogen peroxide solution, wherein the mass fraction of hydrogen peroxide is 30%, the mass ratio of hydrazine hydrate is 30%, and the sodium borohydride solution is prepared into alkaline solution with pH 13.
- 3. The preparation method according to claim 1, wherein the mass ratio of sodium chlorate to graphene in the step (1) is 0.5-6, the oxidation time is 0.5-8 h, the temperature is 0-20 ℃, and the oxygen content in the carboxylated graphene accounts for less than 30% of the total mass of carbon and oxygen elements.
- 4. The method according to claim 1, wherein the concentration of the aqueous solution of carboxylated graphene in step (2) is 0.02 to 5 mg/mL.
- 5. The production method according to claim 1, wherein the transmission electron microscope copper carrying meshes without the supporting film in the step (3) do not overlap each other, and a space should be left between the transmission electron microscope copper carrying meshes.
- 6. The method of claim 1, wherein the speed of lifting the support network or stent is controlled in step (4) so as not to destroy the membrane structure too quickly, and the positive potential is set in the range of 1-10V.
- 7. The method according to claim 1, wherein the reduction in the step (5) comprises thermal reduction, chemical reduction or photo reduction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910082790.5A CN109859999B (en) | 2019-01-23 | 2019-01-23 | Method for preparing transmission electron microscope carrier net by LB membrane method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910082790.5A CN109859999B (en) | 2019-01-23 | 2019-01-23 | Method for preparing transmission electron microscope carrier net by LB membrane method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109859999A CN109859999A (en) | 2019-06-07 |
| CN109859999B true CN109859999B (en) | 2021-01-12 |
Family
ID=66896649
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910082790.5A Active CN109859999B (en) | 2019-01-23 | 2019-01-23 | Method for preparing transmission electron microscope carrier net by LB membrane method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109859999B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111908455A (en) * | 2019-10-30 | 2020-11-10 | 清华大学 | Reduced graphene oxide film and preparation method thereof |
| CN114804088A (en) * | 2022-03-22 | 2022-07-29 | 苏州金墨生物科技有限公司 | Preparation method of graphene oxide suitable for electron microscope imaging |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20120046601A (en) * | 2010-11-02 | 2012-05-10 | 강원대학교산학협력단 | Grid for transmission electron microscope and manufacturing method thereof |
| CN105140083A (en) * | 2015-06-24 | 2015-12-09 | 中国科学院生物物理研究所 | Preparation method of grid of transmission electron microscope |
| CN106276872A (en) * | 2016-08-03 | 2017-01-04 | 合肥工业大学 | The preparation method of self-supporting transparent conductive graphene membrane |
| CN107089653A (en) * | 2017-04-02 | 2017-08-25 | 浙江大学 | A kind of redox graphene carbon supports film transmission electron microscope carrier net and preparation method thereof |
| KR20180032374A (en) * | 2016-09-22 | 2018-03-30 | 주식회사 엘지화학 | Modification method of the support film for TEM analysis of hydrophilic nanoparticles |
-
2019
- 2019-01-23 CN CN201910082790.5A patent/CN109859999B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20120046601A (en) * | 2010-11-02 | 2012-05-10 | 강원대학교산학협력단 | Grid for transmission electron microscope and manufacturing method thereof |
| CN105140083A (en) * | 2015-06-24 | 2015-12-09 | 中国科学院生物物理研究所 | Preparation method of grid of transmission electron microscope |
| CN106276872A (en) * | 2016-08-03 | 2017-01-04 | 合肥工业大学 | The preparation method of self-supporting transparent conductive graphene membrane |
| KR20180032374A (en) * | 2016-09-22 | 2018-03-30 | 주식회사 엘지화학 | Modification method of the support film for TEM analysis of hydrophilic nanoparticles |
| CN107089653A (en) * | 2017-04-02 | 2017-08-25 | 浙江大学 | A kind of redox graphene carbon supports film transmission electron microscope carrier net and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| Few-Layer Graphene as a Support Film for Transmission Electron Microscopy Imaging of Nanoparticles;James R. McBride等;《ACS Applied Materials and Interfaces》;20091103;第1卷(第12期);第2886-2892页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109859999A (en) | 2019-06-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Mayyas et al. | Liquid‐metal‐templated synthesis of 2D graphitic materials at room temperature | |
| Kurra et al. | A general strategy for the fabrication of high performance microsupercapacitors | |
| Ahmad et al. | One-step synthesis and decoration of nickel oxide nanosheets with gold nanoparticles by reduction method for hydrazine sensing application | |
| Lu et al. | Direct vapor deposition growth of 1T′ MoTe2 on carbon cloth for electrocatalytic hydrogen evolution | |
| CN110783577A (en) | Platinum nickel cobalt alloy @ carbon nanotube composite material, and preparation and application thereof | |
| Wei et al. | Electrochemically synthesized Cu/Pt core-shell catalysts on a porous carbon electrode for polymer electrolyte membrane fuel cells | |
| CN109859999B (en) | Method for preparing transmission electron microscope carrier net by LB membrane method | |
| CN107399729A (en) | A kind of bimetallic MOFs nitrogenous graphitized carbon material | |
| Shi et al. | Strongly coupled W2C atomic nanoclusters on N/P‐codoped graphene for kinetically enhanced sulfur host | |
| WO2020164360A1 (en) | Upright few-layer graphene-metal nanoparticle composite catalytic electrode | |
| US11512000B2 (en) | Porous graphene film, its manufacturing method and electronic product | |
| Cheng et al. | Strongly coupling of amorphous/crystalline reduced FeOOH/α-Ni (OH) 2 heterostructure for extremely efficient water oxidation at ultra-high current density | |
| Wang et al. | Emerging synthesis strategies of 2D MOFs for electrical devices and integrated circuits | |
| WO2018120601A1 (en) | Preparation method for self-supporting thin film of graphene-enhanced three-dimensional porous carbon | |
| Du et al. | Template-directed fabrication of zeolitic imidazolate framework-67-derived coating materials on nickel/titanium alloy fiber substrate for selective solid-phase microextraction | |
| JP2007136645A (en) | Method for manufacturing carbon nanotube (cnt) thin film and biosensor using the thin film | |
| CN105322187A (en) | Synthesis of alloy nanoparticles as a stable core for core-shell electrocatalysts | |
| JP2008183508A (en) | Composite material and its manufacturing method | |
| CN109786196B (en) | Method for preparing grid of transmission electron microscope | |
| Shen et al. | CoSe2/MoS2 heterostructures to couple polysulfide adsorption and catalysis in lithium‐sulfur batteries | |
| WO2021196518A1 (en) | Lead dioxide-carbon nanotube adsorptive submicron electrochemical reactor as well as preparation method therefor and application thereof | |
| Ruan et al. | Enhanced electrochemical properties of surface roughed Pt nanowire electrocatalyst for methanol oxidation | |
| Zhao et al. | Decoration of ultrafine platinum-ruthenium particles on functionalized graphene sheets in supercritical fluid and their electrocatalytic property | |
| Posudievsky et al. | Facile mechanochemical preparation of nitrogen and fluorine co-doped graphene and its electrocatalytic performance | |
| Islam et al. | Electrodeposition and characterization of silicon films obtained through electrochemical reduction of SiO2 nanoparticles |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20230918 Address after: No. 2 Gongqing Street, Jinzhuang Village, Anju Street Office, Rencheng District, Jining City, Shandong Province, 272055 Patentee after: He Maochang Address before: 224000 No.2, hope Avenue South Road, Yancheng City, Jiangsu Province Patentee before: YANCHENG TEACHERS University |