WO2016008290A1

WO2016008290A1 - Oxidized graphene nano-ribbon/polymer composite film and preparation method therefor

Info

Publication number: WO2016008290A1
Application number: PCT/CN2015/071165
Authority: WO
Inventors: 郑玉婴; 樊志敏; 林锦贤
Original assignee: 福州大学
Priority date: 2014-07-18
Filing date: 2015-01-21
Publication date: 2016-01-21
Also published as: CN104072979A; CN104072979B

Abstract

Disclosed are an oxidized graphene nano-ribbon/polymer composite film and a preparation method therefor. A multi-walled carbon nano-tube is longitudinally cut into oxidized graphene nano-ribbons with strip-shaped structures through an oxidation method, and then the oxidized graphene nano-ribbons are compounded with a polymer to form the film. The composite film prepared according to the invention is excellent in barrier property and mechanical property, and has a certain fixed degree of transparency, thereby being widely applied to the field with higher barrier requirements. At present, mass production of carbon nano-tubes is realized in domestic and foreign countries, so that the preparation cost of the oxidized graphene nano-ribbon is greatly reduced. The barrier property and mechanical property of the composite film can be greatly improved only with few oxidized graphene nano-ribbons. The preparation method is simple, high in operability, and is suitable for large-scale industrialized production.

Description

Graphene oxide nanobelt/polymer composite film and preparation method thereof

Technical field

The invention belongs to the technical field of preparation of polymer composite films, and particularly relates to a graphene oxide nanobelt/polymer composite film and a preparation method thereof.

Background technique

The ideal graphene is a single-layer two-dimensional infinite structure with high crystallinity and semi-metal electrical properties. It has become a research hotspot in the fields of energy storage materials, electronic devices, composite materials, etc., and graphene has excellent impermeability. Sexuality is currently favored in the field of barrier materials, but the surface of graphene sheets prepared in practice often has wrinkle and undulation defects, which will inevitably affect its application in many fields. A new type of carbon material graphene nanobelt that has emerged in recent years has become a best candidate in the fields of transparent electrodes and barrier fillers due to its unique high aspect ratio, low defect, and controllable morphology.

The graphene nanoribbon is a thin strip-shaped material formed by a sp ² hybrid orbital of carbon atoms, and can be prepared by a CVD method, a lithography method, an ultrasonic method, or a longitudinal oxidation-cut carbon nanotube method. Carbon nanotubes are mainly classified into single-walled carbon nanotubes and multi-walled carbon nanotubes. It is known from the known literature that graphene nanoribbons which are conventionally obtained by longitudinal oxidation-oxidation of single-walled carbon nanotubes are easily entangled and are not advantageous for use. The graphene nanoribbons obtained by cutting with multi-wall carbon nanotubes have neat edges, few band structure defects, excellent electron transport performance, mechanical properties, transparency and impermeability, but their preparation costs are relatively expensive. Therefore, it is an effective way to solve the above problems by replacing the graphene nanoribbons with the same impenetrable and low-cost graphene oxide nanobelts, which are used in the field of barriers. In addition, due to the characteristics of the polymer itself, some small molecules such as gases will permeate in the past, which will inevitably affect the application of polymer materials in the field of barriers. By adding high-barrier graphene oxide nanoribbons, the barrier properties of polymers can be improved. .

Summary of the invention

The object of the present invention is to provide a graphene oxide nanobelt/polymer composite film and a preparation method thereof, and the graphene oxide nanobelt/polymer composite film prepared by the method of the invention has excellent barrier properties and mechanical properties, and can Widely used in food, pharmaceutical packaging and electronic surface packaging materials. The preparation method of the invention is scientific and reasonable, simple in process, strong in operability, and suitable for large-scale industrial production.

To achieve the above object, the present invention adopts the following technical solutions:

A graphene oxide nanobelt/polymer composite film is a graphene nanobelt in which a multi-walled carbon nanotube is longitudinally cut into a strip structure by oxidation, and then a graphene nanobelt is polymerized by a solution forming method. The compound is composited to form the film.

The preparation of the graphene oxide nanobelt/polymer composite film comprises the following steps:

1) 15-20g of polymer is dissolved in 40-60ml of solvent, swelled in a blast oven at 80-100 ° C for 12h;

2) Dissolve 0.045-0.15g of graphene oxide nanobelt in 10-20ml of solvent, 100W ultrasonic dispersion for 20-30min;

3) mixing the polymer solution of step 1) and the ultrasonically dispersed graphene oxide nanobelt of step 2) uniformly, dispersing 100W ultrasonically for 1-5 h, and stirring for 1-3 h on a mechanical stirrer to form a paste liquid;

4) Extract the air in the paste liquid on the filter, place the glass plate on the coater, and then apply a film of 0.10±0.01mm thickness with a wet film preparer, then place the glass plate at a vacuum of 60-65 °C. Vacuum is applied in the drying oven; after 10-20 minutes, the vacuum drying oven is opened, the solvent vapor is discharged, and then the glass plate is dried at 70-80 ° C for 4-8 hours, then allowed to cool at room temperature, and the film is removed to obtain the graphite oxide. A olefinic nanoribbon-polymer composite film.

The preparation of the graphene oxide nanobelt includes the following steps:

1) Add 20-30 ml of a 85.8% by mass H ₃ PO ₄ solution to a 500 ml round bottom flask with a magnetic rotor, then add 180-200 ml of concentrated H ₂ SO ₄ to the round bottom flask, 300r Stir evenly at /min;

2) Add 1-1.5 g of multi-walled carbon nanotubes to the solution of step 1), stir for 1-2 h, then slowly add 6-9 g of KMnO ₄ to the above mixture in 3 steps in 30 min, and then stir 15 -30min;

3) Move the reaction system of step 2) to an oil bath at 55-65 ° C, stir the reaction at 300 r / min for 2-6 h, let cool to room temperature, and then pour into 5-10 ml H ₂ O ₂ The ice water mixture was condensed for 24 hours, at which time the solution turned dark green, indicating that the reaction was complete;

4) The solution of step 3) is ultrasonically dispersed at a power of 100 W for 20-30 min, repeatedly washed and filtered on a polytetrafluoroethylene film with 10% by mass of HCl and deionized water, and finally vacuum dried at 60 ° C for 24 h to obtain the above. Graphene oxide nanobelts.

The polymer is any one of polyester thermoplastic polyurethane, polyether thermoplastic polyurethane, polyvinyl alcohol, polyvinyl chloride, polymethyl methacrylate, polyaniline, polyamide, polystyrene or polyethylene. .

The solvent is any one of N-N dimethylformamide, tetrahydrofuran, chloroform, toluene or water.

Conventionally, the use of graphene oxide to prepare a composite film has many defects in the base portion of the graphene oxide, so it does not have a good barrier effect on small molecular substances, and the graphene oxide nanoribbon has only the edge of the strip which is defective, and its surface is It can be well contacted with the polymer matrix, and therefore, the composite film prepared by the same has better impermeability than the composite film prepared by using graphene oxide nano.

On the other hand, the original multi-walled carbon nanotubes have no obvious effect on the reinforced polymer composite because the multi-walled carbon nanotubes have only a tubular surface contact, and the graphene nanoribbons are cut longitudinally into a strip structure. After that, since both sides of the graphene oxide nanobelt can be well contacted with the polymer matrix, the contact area is significantly increased, thereby being significantly enhanced. The properties of polymer films.

The advantages of the invention are:

(1) At present, large-scale industrial production of carbon nanotubes has been realized at home and abroad, and the preparation of graphene oxide nanobelts is also very inexpensive. At the same time, the present invention can prepare barrier properties by using only a small amount of graphene oxide nanobelts. The composite film with excellent mechanical properties makes it low in cost, can be widely applied in the field with high barrier requirements, and has simple preparation process and strong operability, and is suitable for large-scale industrial production.

(2) The composite film prepared by the invention not only has excellent barrier properties and mechanical properties, but also has certain transparency, and can be widely applied in the fields of food, pharmaceutical packaging and surface packaging materials of electronic products.

DRAWINGS

FIG. 1 is a schematic diagram showing the barrier principle of a graphene oxide nanobelt/polymer composite film.

2 is an SEM image of a multi-walled carbon nanotube and a graphene oxide nanobelt prepared by the present invention, wherein A is a multi-walled carbon nanotube and B is a graphene oxide nanobelt.

3 is a TEM image of a multi-walled carbon nanotube and a graphene oxide nanobelt prepared by the present invention, wherein A is a multi-walled carbon nanotube and B is a graphene oxide nanobelt.

4 is a Raman comparison diagram of multi-walled carbon nanotubes and graphene oxide nanobelts prepared by the present invention.

Figure 5 is a comparison of XRD of multi-walled carbon nanotubes with the graphene oxide nanoribbons prepared by the present invention.

6 is an infrared contrast diagram of a multi-walled carbon nanotube and a graphene oxide nanobelt prepared by the present invention.

detailed description

The invention is further illustrated by the following examples, but the scope of the invention is not limited to the following examples.

The preparation of graphene oxide nanoribbons includes the following steps:

1) Add 20 ml of 85.8% H ₃ PO ₄ solution to a 500 ml round bottom flask with a magnetic rotor, then add 200 ml of concentrated H ₂ SO ₄ to the round bottom flask at 300 r/min. Stir well under;

2) 1g of multi-walled carbon nanotubes were added to the solution of step 1), stirred for 2h, then 6g of KMnO ₄ was slowly added to the above mixture in 3 minutes in 30min, and then stirred for 20min;

3) The reaction system of step 2) was transferred to an oil bath at 55 ° C, stirred at 300 r / min for 2 h, allowed to cool to room temperature, and then poured into an ice water mixture containing 5 ml of H ₂ O ₂ to coagulate. At 24h, the solution turned dark green, indicating complete reaction;

4) The solution of step 3) was ultrasonically dispersed at 100 W for 30 min, repeatedly washed and filtered on a polytetrafluoroethylene film with 10% by mass of HCl and deionized water, and finally dried at 60 ° C for 24 h to obtain the graphite oxide. Alkene nanobelts.

2 is an SEM image of a multi-walled carbon nanotube and a prepared graphene oxide nanobelt, and FIG. 3 is a multi-walled carbon nanotube and TEM image of the prepared graphene oxide nanobelts.

4 is a Raman comparison diagram of the multi-walled carbon nanotubes and the prepared graphene oxide nanobelts. In FIG. 4, the multi-walled carbon nanotubes represent D and G peaks at 1317 cm ^-1 and 1594 cm ^-1 , and are cut to obtain graphite oxide. The peak shape of the D peak of 1326 cm ^-1 and the G peak of 1594 cm ^-1 of the ene nanobelt relative to the multi-walled carbon nanotube became stronger and wider, indicating that lattice distortion and structural defects increased, demonstrating that the multi-walled carbon nanotube was opened.

Figure 5 is a comparison of XRD of multi-walled carbon nanotubes with the prepared graphene oxide nanobelts. In Figure 5, the multi-walled carbon nanotubes exhibit strong diffraction peaks at 2θ=26.26° and exhibit sharp shapes, which are derived from the Bragg equation. The layer spacing of the multi-walled carbon nanotubes is 0.34 nm. The graphene oxide nanobelts showed strong diffraction peaks at 2θ=9.06°, and the corresponding layer spacing was 0.98 nm, indicating that the multi-walled carbon nanotubes were successfully longitudinally cut into graphene oxide nanoribbons; at 2θ=26.26° The peak shape is relatively flat, indicating that the multi-walled carbon nanotubes are substantially completely oxidized and chopped into graphene oxide nanoribbons.

FIG 6 is a comparison of infrared MWCNTs nano graphene oxide prepared with FIG. 6 MWCNTs faint absorption peak of C-OH at 1043cm ^-1, 1580cm ^-1 has at C Characteristic absorption peak of =C. The graphene oxide nanobelts showed new absorption peaks at 1225cm ^-1 and 1725cm ^-1 , corresponding to C=O and COC, respectively, and OH stretching absorption peak at 3395cm ^-1 , indicating that the multi-walled carbon nanotubes were all cut into strips. Graphene oxide nanoribbons.

Example 1

1) 15g of polyester thermoplastic polyurethane was dissolved in 40ml N-N dimethylformamide, swelled in a blast oven at 80 ° C for 12h;

2) Dissolve 0.045 g of graphene oxide nanobelt in 10 ml of N-N dimethylformamide, and disperse 100 W ultrasonically for 20 min;

3) The polymer solution of step 1) and the ultrasonically dispersed graphene oxide nanobelt of step 2) are uniformly mixed, ultrasonically dispersed at 100 W for 1 h, and then stirred on a mechanical stirrer for 3 h to form a paste-like liquid;

4) Pour the paste liquid into a small volumetric flask with a straw, and then extract the air from the paste liquid on the filter until there is no air bubble in the volumetric flask; place the glass plate on the coater and then use the wet The film preparation device was coated with a film having a thickness of 0.09 mm, and then the glass plate was placed in a vacuum drying oven at 60 ° C to evacuate; after 10 minutes, the vacuum drying oven was opened, the solvent vapor was discharged, and then the glass plate was dried at 70 ° C for 8 hours. After cooling at room temperature, the film was removed to obtain the graphene oxide nanobelt-polymer composite film.

Example 2

1) Dissolve 15 g of polyether thermoplastic polyurethane in 60 ml of tetrahydrofuran and swell in a blast drying oven at 80 ° C 12h;

2) Dissolve 0.075 g of graphene oxide nanobelt in 10 ml of tetrahydrofuran, and disperse 100 W ultrasonically for 20 min;

3) The polymer solution of step 1) and the 2) ultrasonically dispersed graphene oxide nanobelt are uniformly mixed, 100W ultrasonically dispersed for 3 hours, and then stirred on a mechanical stirrer for 2 hours to form a paste liquid;

4) Pour the paste liquid into a small volumetric flask with a straw, and then extract the air from the paste liquid on the filter until there is no air bubble in the volumetric flask; place the glass plate on the coater and then use the wet The film preparation device was coated with a film having a thickness of 0.09 mm, and then the glass plate was placed in a vacuum drying oven at 62 ° C to evacuate; after 15 minutes, the vacuum drying oven was opened, the solvent vapor was discharged, and then the glass plate was dried at 75 ° C for 5 hours. After cooling at room temperature, the film was removed to obtain the graphene oxide nanobelt-polymer composite film.

Example 3

The pure polyester thermoplastic polyurethane film was prepared in the same manner as in Example 1 without adding graphene oxide nanobelts as Comparative Experiment Group 1.

Example 4

The pure polyether thermoplastic polyurethane film was prepared in the same manner as in Example 2 without adding graphene oxide nanobelts as Comparative Experiment Group 2.

Example 5

Step 2) Dissolve 0.045 g of graphene oxide in 10 ml of NN dimethylformamide, and disperse 100 W ultrasonically for 20 min; prepare a graphene oxide/polyester thermoplastic polyurethane composite film according to the conditions of Example 1 as a comparative experiment group. 3.

Performance Testing:

(1) Oxygen transmission rate test

According to the national standard GBT1038-2000, the film prepared in the examples was subjected to oxygen transmission test; the film sample was a wafer having an area of 50 cm ² , and the test accuracy was 0.01 cc/m ² .day.0.1 MPa, and the degree of vacuum was <10 Pa. The temperature control method adopts semiconductor bidirectional high-efficiency temperature control, and finally takes the average value of oxygen permeability of three samples of each sample.

(2) Mechanical properties test of composite film

The tensile properties of the films obtained in the examples were tested according to the national standard GBT 528-2009.

The test results are shown in Table 1.

Table 1 performance test results

Comparing the results of Table 1, it can be seen that the graphene oxide nanobelt/polymer composite film prepared by the invention has lower oxygen permeability and better mechanical properties than the pure polymer film; and in the case of equal amount of raw materials. The graphene oxide nanobelt/polymer composite film has better barrier properties than the graphene oxide/polymer composite film. Therefore, it has been experimentally shown that the graphene oxide nanobelt/polymer composite film of the present invention has good performance and is suitable for use in fields with high barrier requirements.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should fall within the scope of the present invention.

Claims

A graphene oxide nanobelt/polymer composite film characterized in that a multi-walled carbon nanotube is longitudinally cut into a ribbon-structured graphene oxide nanobelt by oxidation, and then a graphene nanoparticle is formed by a solution forming method. The tape is composited with a polymer to form the film.
A method for preparing a graphene oxide nanobelt/polymer composite film according to claim 1, comprising the steps of:

After dissolving the polymer in a solvent, it is swollen in a blast drying oven at 80-100 ° C for 12 h;

2) dissolving the graphene oxide nanobelt in a solvent, and dispersing 100W ultrasonically for 20-30 min;

3) mixing the polymer solution of step 1) and the ultrasonically dispersed graphene oxide nanobelt of step 2) uniformly, dispersing 100W ultrasonically for 1-5 h, and stirring for 1-3 h on a mechanical stirrer to form a paste liquid;

4) Extract the air in the paste liquid on the filter, place the glass plate on the coater, and then apply a film of 0.10±0.01mm thickness with a wet film preparer, then place the glass plate at a vacuum of 60-65 °C. A vacuum is applied in the drying oven to remove the solvent; then the glass plate is dried at 70-80 ° C for 4-8 h, then allowed to cool at room temperature, and the film is removed to obtain the graphene oxide nanobelt/polymer composite film.
The method for preparing a graphene oxide nanobelt/polymer composite film according to claim 2, wherein the method for preparing the graphene oxide nanobelt comprises the following steps:

Adding a mass fraction of 85.8% H 3 PO 4 solution to a round bottom flask with a magnetic rotor, then adding concentrated H 2 SO 4 to the round bottom flask and stirring uniformly at 300 r/min;

Adding multi-walled carbon nanotubes to the solution of step 1), stirring for 1-2 h, then slowly adding KMnO 4 to the above mixture, and stirring for another 15-30 min;

Move the reaction system of step 2) to an oil bath at 55-65 ° C, stir the reaction at 300 r / min for 2-6 h, let cool to room temperature, and then pour into ice water mixture containing H 2 O 2 Condensation 24h;

The solution of the step 3) was ultrasonically dispersed at a power of 100 W for 20-30 min, repeatedly washed and filtered on a polytetrafluoroethylene film with 10% by mass of HCl and deionized water, and finally vacuum dried at 60 ° C for 24 h to obtain the graphite oxide. Alkene nanobelts.
The method for preparing a graphene oxide nanobelt/polymer composite film according to claim 2, wherein the polymer is a polyester thermoplastic polyurethane, a polyether thermoplastic polyurethane, a polyvinyl alcohol, a polyvinyl chloride, Any of polymethyl methacrylate, polyaniline, polyamide, polystyrene or polyethylene.
The method for preparing a graphene oxide nanobelt/polymer composite film according to claim 2, characterized in that It is to be noted that the solvent is any one of N-N dimethylformamide, tetrahydrofuran, chloroform, toluene or water.