CN114736669A - CMC-Na/CdS @ ZnS flexible quantum dot film and preparation method thereof - Google Patents
CMC-Na/CdS @ ZnS flexible quantum dot film and preparation method thereof Download PDFInfo
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Abstract
The invention discloses a CMC-Na/CdS @ ZnS flexible quantum dot film and a preparation method thereof, belonging to the field of materials. The method for preparing the CMC-Na/CdS @ ZnS flexible quantum dot film comprises the following steps: (1) dissolving sodium carboxymethylcellulose in water, and adjusting pH to 8-8.5; then adding a cadmium source solution into the sodium carboxymethyl cellulose solution, and reacting for 2-3h at 50-60 ℃ in an inert gas atmosphere; adding a sulfur source solution after the reaction is finished, and uniformly mixing; alternately adding zinc source solution and sulfur source solution, and reacting at 50-60 deg.C for 2-5 min; after the reaction is finished, obtaining CMC-Na/CdS @ ZnS quantum dot dispersion liquid; (2) concentrating the CMC-Na/CdS @ ZnS quantum dot dispersion liquid to 1/3-1/4 with the original mass; and mixing the concentrated solution with polyurethane emulsion, and drying to obtain the CMC-Na/CdS @ ZnS flexible quantum dot film. The flexible quantum dot film disclosed by the invention can have certain mechanical strength on the premise of keeping the original fluorescence property; meanwhile, the heat stability is excellent, the application range is wide, and the heat stabilizer can be used in the temperature range from room temperature to 200 ℃.
Description
Technical Field
The invention relates to a CMC-Na/CdS @ ZnS flexible quantum dot film and a preparation method thereof, belonging to the field of materials.
Background
The quantum dots are small in size, can emit wavelength covering the whole visible light region, can be adjusted in wavelength, can be assembled into a light-emitting device by the quantum dots with different sizes, can adjust the light-emitting wavelength of a light source at will, and has excellent advantages in LED manufacturing. In the display field, the typical value of the color gamut of the LCD display equipment based on the common LED is improved from 72 percent to more than 100 percent by adding quantum dot devices, the color reducibility of the display equipment is greatly improved, and the pursuit of various display manufacturers all over the world is aroused.
Polyurethane related materials have been incorporated into a large number of consumer products for many years and continue to play an important role in our daily lives. With the increasingly wide application field of polymer films and the increasingly high requirements on the performance of film materials, the common polysulfone, polyolefin film and the like can not completely meet the market demands, and under the condition, the polyurethane film is produced. The polyurethane film has the advantages of optical transparency, soft hand feeling, high extensibility, durability, easy processing, water resistance and air permeability, and is widely applied to daily life as high-grade or special textile fabrics.
The most convenient and direct method for manufacturing the quantum dot composite film is to mix colloidal quantum dots and polymers, dry and form a film. However, the aggregation of colloidal quantum dots during blending or solvent evaporation can significantly reduce the PL strength of the resulting quantum dot composite film. Although researchers mix the waterborne polyurethane and the quantum dots as the surface coating material, fluorescence and mechanical properties are obtained, experimental results show that the increase of photoluminescence intensity is increased along with the proportion of the added quantum dots, and the mechanical intensity and the photoluminescence intensity cannot be increased simultaneously. Researchers also try to prepare quantum dot films by a QDs/PU/POSS system, but the POSS is introduced only for improving the optical and thermal stability of the quantum dot films, and no research is made on improving the PL strength and the mechanical strength of the composite films at the same time. And the capping agent-coated quantum dots are difficult to maintain long-term stability due to oxidation and degradation of the polymer. Furthermore, the nano-carriers need to be decorated with surface charges to avoid aggregation. In order to maintain the stability of colloidal quantum dots, a high loading of the nanocarriers is generally required. However, a large number of nano-carriers tend to aggregate in the solvent evaporation process, resulting in severe phase separation from the polymer resin, thereby reducing the PL strength and mechanical properties of the quantum dot composite film. Therefore, it is still a great challenge to obtain both high PL strength and mechanical properties of quantum dot composite films.
Although various preparation methods have been developed from the current preparation methods of quantum dot films, it is not difficult to find that many problems such as complicated preparation method process, low economic benefit, practicability, environmental pollution, limitation of external conditions for using the films and the like exist.
Disclosure of Invention
[ problem ] to
The carbon quantum dot film prepared at present has the problems of complex preparation mode and process, low economic benefit, practicability, environmental pollution, limitation of external conditions in the use of the film, incapability of considering high PL strength and mechanical property and the like.
[ solution ]
In order to solve at least one problem, the CMC-Na/CdS @ ZnS flexible quantum dot film is prepared by combining CMC-Na/CdS @ ZnS quantum dots and polyurethane.
The first purpose of the invention is to provide a method for preparing CMC-Na/CdS @ ZnS flexible quantum dot film, which comprises the following steps:
(1) preparing CMC-Na/CdS @ ZnS quantum dot dispersion liquid
Dissolving sodium carboxymethylcellulose in water, and adjusting pH to 8-8.5 to obtain sodium carboxymethylcellulose solution; then adding a cadmium source solution into the sodium carboxymethyl cellulose solution, and reacting for 2-3h at 50-60 ℃ in an inert gas atmosphere; adding a sulfur source solution after the reaction is finished, and uniformly mixing; alternately adding zinc source solution and sulfur source solution, and reacting at 50-60 deg.C for 2-5 min; after the reaction is finished, obtaining CMC-Na/CdS @ ZnS quantum dot dispersion liquid;
(2) preparation of CMC-Na/CdS @ ZnS flexible quantum dot film
Concentrating the CMC-Na/CdS @ ZnS quantum dot dispersion liquid to 1/3-1/4 with the original mass to obtain a concentrated liquid; and mixing the concentrated solution with polyurethane emulsion, and drying to obtain the CMC-Na/CdS @ ZnS flexible quantum dot film.
In one embodiment of the present invention, the ratio of the sodium carboxymethyl cellulose to the water in the sodium carboxymethyl cellulose solution in step (1) is 0.02 to 0.04 g: 50 mL.
In one embodiment of the present invention, the pH adjustment in step (1) is performed by using sodium hydroxide solution, and the concentration of the sodium hydroxide solution is 0.1-0.2M.
In one embodiment of the present invention, the cadmium source solution in step (1) comprises one of a cadmium chloride solution and a cadmium acetate solution; wherein the concentration of the cadmium source solution is 0.02M.
In one embodiment of the present invention, the inert gas in step (1) includes one or more of nitrogen, helium, and neon.
In one embodiment of the present invention, the sulfur source solution in step (1) comprises one of a sodium sulfide solution and a thiourea solution, wherein the concentration of the sulfur source solution is 0.01-0.04M.
In one embodiment of the invention, the zinc source solution in the step (1) comprises one of zinc nitrate solution and zinc sulfate; wherein the concentration of the zinc source solution is 0.01-0.04M.
In one embodiment of the present invention, the solvent of the sulfur source solution, the cadmium source solution and the zinc source solution in step (1) is water.
In one embodiment of the present invention, the concentration ratio of the cadmium source solution, the sulfur source solution and the zinc source solution in step (1) is 1: 1; the adding volume ratio of the cadmium source solution, the first sulfur source adding solution, the zinc source solution and the second sulfur source adding solution is 1: 1: 1: 1.
in one embodiment of the present invention, the volume ratio of the water to the cadmium source solution in the sodium carboxymethyl cellulose solution in the step (1) is 48 to 52: 1.
in one embodiment of the invention, the adding rate of the first adding of the sulfur source solution, the zinc source solution and the second adding of the sulfur source solution in the step (1) is 0.1-0.2 mL/min.
In one embodiment of the present invention, the concentration in step (2) is performed at 60-70 ℃.
In one embodiment of the present invention, the mass ratio of the concentrated solution in the step (2) to the polyurethane emulsion is 5: 6-8.
In one embodiment of the invention, the polyurethane emulsion in step (2) is an aqueous polyurethane emulsion, has a viscosity of 300-350 mPa.S and a solid content of 20-40% (mass percent), and is commercially available.
In one embodiment of the present invention, the mixing in step (2) is performed by ultrasonic oscillation for 0.5-2 min.
In one embodiment of the present invention, the drying in step (2) may be performed at room temperature.
The second purpose of the invention is to obtain the CMC-Na/CdS @ ZnS flexible quantum dot film prepared by the method.
The third purpose of the invention is the application of the CMC-Na/CdS @ ZnS flexible quantum dot film in displays and LEDs.
[ advantageous effects ]
(1) Although the cadmium source and the sulfur source adopted by the invention have certain harm, the harm of the insulator can be effectively reduced to a certain extent through the core-shell structure, the ZnS shell layer can effectively protect the CdS nuclear layer and reduce the contact between the nuclear layer and external oxygen, and the crystal lattice strength can be enhanced through the Zn/Cd alloy, so that the stability of the crystal lattice is improved to a great extent. Therefore, the method not only can prepare the stable water-phase quantum dots, but also has the characteristic of environmental friendliness.
(2) The flexible quantum dot film disclosed by the invention can have certain mechanical strength on the premise of keeping the original fluorescence property; meanwhile, the heat stability is excellent, the application range is wide, and the heat stabilizer can be used in the temperature range from room temperature to 200 ℃.
(3) The method is simple, easy to operate and high in repeatability.
Drawings
FIG. 1 is a flow chart for preparing CMC-Na/CdS @ ZnS quantum dot dispersion.
FIG. 2 is a PL spectrum (A) and luminescence plot (B) of CMC-Na/CdS @ ZnS flexible quantum dot films prepared in examples 1-4.
FIG. 3 is a spectrum chart of different CMC-Na/CdS @ ZnS quantum dot dispersions and different ratios of flexible quantum dot films.
FIG. 4 is a graph of transmittance of different CMC-Na/CdS @ ZnS flexible quantum dot films.
FIG. 5 is an SEM topography of different CMC-Na/CdS @ ZnS flexible quantum dot films.
FIG. 6 is a graph of tensile strength for different CMC-Na/CdS @ ZnS flexible quantum dot films.
FIG. 7 is a luminescence diagram of different CMC-Na/CdS @ ZnS flexible quantum dot films.
FIG. 8 shows the thermal stability test results of different CMC-Na/CdS @ ZnS flexible quantum dot films.
Detailed Description
The following description of the preferred embodiments of the present invention is provided for the purpose of better illustrating the invention and is not intended to limit the invention thereto.
The test method comprises the following steps:
measurement of PL spectra: placing the dispersion in a quartz cuvette by using a fluorescence spectrometer (FS 5); the quantum dot solution does not need any pretreatment; the quantum dot film is placed in a glass vessel special for measuring a solid by a fluorescence spectrometer; the rest of the operations can be performed by referring to the specific operation method of the used instrument.
And (3) transmittance test: an ultraviolet-visible spectrophotometer (UV-vis) is adopted, and specifically comprises the following components: the sample preparation specification is smaller than the size of the cuvette, and the transmittance can be measured by attaching the quantum dot film to one side of the inner wall of the cuvette; the rest of the operations can be performed by referring to the specific operation method of the used instrument.
And (3) testing tensile strength: using an electronic universal tester, sample standards: 2cm in length and 0.6cm in width, dumbbell-shaped, and 2mm/sec in stretching rate; the rest of the operations can be performed by referring to the specific operation method of the used instrument.
Testing of thermal stability: thermogravimetric analysis (TGA) was carried out under nitrogen flow at a temperature range of room temperature-400 ℃ with a heating rate of 10 ℃/min; the rest of the operations can be performed by referring to the specific operation method of the used instrument.
Example 1
A method for preparing a CMC-Na/CdS @ ZnS flexible quantum dot film comprises the following steps:
(1) preparing CMC-Na/CdS @ ZnS quantum dot dispersion liquid
Dissolving 0.03g of sodium carboxymethylcellulose in 50mL of water, and stirring at room temperature to completely dissolve the sodium carboxymethylcellulose; adjusting pH to 8 with dilute sodium hydroxide solution (concentration of 0.1M) to obtain sodium carboxymethylcellulose solution; then adding 1mL of cadmium chloride solution (0.02M) into the sodium carboxymethylcellulose solution, ultrasonically oscillating for 15min, and stirring (250rpm) at 50 ℃ in a nitrogen atmosphere to react for 2 h; after the reaction was complete, 1mL of sodium sulfide solution (0.02M) was added at a rate of 0.1 mL/min; stirring for 2min, sequentially and alternately adding 1mL of zinc nitrate solution (0.02M) and 1mL of sodium sulfide solution (0.02M) at the rate of 0.2mL/min, and reacting for 5min at 50 ℃; after the reaction is finished, obtaining CMC-Na/CdS @ ZnS quantum dot dispersion liquid; as shown in FIG. 1;
(2) preparation of CMC-Na/CdS @ ZnS flexible quantum dot film
Heating and concentrating the CMC-Na/CdS @ ZnS quantum dot dispersion liquid at 60 ℃ to 1/3 with the original mass to obtain a concentrated liquid; mixing the concentrated solution and the aqueous polyurethane emulsion (viscosity of 250-350mPa & S, solid content of 20-40%) in a ratio of 5: 8, uniformly mixing, ultrasonically oscillating for 1min, and naturally drying the mixed solution in a culture dish to obtain a CMC-Na/CdS @ ZnS flexible quantum dot film; wherein the thickness of the film is 0.14 mm.
Example 2
A method for preparing a CMC-Na/CdS @ ZnS flexible quantum dot film comprises the following steps:
(1) preparation of CMC-Na/CdS @ ZnS quantum dot dispersion liquid
Dissolving 0.03g of sodium carboxymethylcellulose in 50mL of water, and stirring at room temperature to completely dissolve the sodium carboxymethylcellulose; adjusting pH to 8 with dilute sodium hydroxide solution (concentration of 0.1M) to obtain sodium carboxymethylcellulose solution; then adding 1mL of cadmium chloride solution (0.02M) into the sodium carboxymethylcellulose solution, ultrasonically oscillating for 15min, and stirring (250rpm) at 50 ℃ in a nitrogen atmosphere to react for 2 h; after the reaction was complete, 1mL of sodium sulfide solution (0.01M) was added at a rate of 0.1 mL/min; stirring for 2min, sequentially and alternately adding 1mL of zinc nitrate solution (0.01M) and 1mL of sodium sulfide solution (0.01M) at the rate of 0.2mL/min, and reacting for 5min at 50 ℃; after the reaction is finished, obtaining CMC-Na/CdS @ ZnS quantum dot dispersion liquid;
(2) preparation of CMC-Na/CdS @ ZnS flexible quantum dot film
Heating and concentrating the CMC-Na/CdS @ ZnS quantum dot dispersion liquid at 60 ℃ to 1/3 with the original mass to obtain a concentrated liquid; mixing the concentrated solution and the aqueous polyurethane emulsion (viscosity of 250-350mPa & S, solid content of 20-40%) in a ratio of 5: 8, uniformly mixing, ultrasonically oscillating for 1min, and naturally drying the mixed solution in a culture dish to obtain a CMC-Na/CdS @ ZnS flexible quantum dot film; wherein the thickness of the film is 0.14 mm.
Example 3
A method for preparing a CMC-Na/CdS @ ZnS flexible quantum dot film comprises the following steps:
(1) preparing CMC-Na/CdS @ ZnS quantum dot dispersion liquid
Dissolving 0.03g of sodium carboxymethylcellulose in 50mL of water, and stirring at room temperature to completely dissolve the sodium carboxymethylcellulose; adjusting pH to 8 with dilute sodium hydroxide solution (concentration of 0.1M) to obtain sodium carboxymethylcellulose solution; then adding 1mL of cadmium chloride solution (0.02M) into the sodium carboxymethylcellulose solution, ultrasonically oscillating for 15min, and stirring (250rpm) at 50 ℃ in a nitrogen atmosphere to react for 2 h; after the reaction was complete, 1mL of sodium sulfide solution (0.03M) was added at a rate of 0.1 mL/min; stirring for 2min, sequentially and alternately adding 1mL of zinc nitrate solution (0.03M) and 1mL of sodium sulfide solution (0.03M) at the speed of 0.2mL/min, and reacting for 5min at 50 ℃; after the reaction is finished, obtaining CMC-Na/CdS @ ZnS quantum dot dispersion liquid;
(2) preparation of CMC-Na/CdS @ ZnS flexible quantum dot film
Heating and concentrating the CMC-Na/CdS @ ZnS quantum dot dispersion liquid at 60 ℃ to 1/3 with the original mass to obtain a concentrated liquid; mixing the concentrated solution and the aqueous polyurethane emulsion (viscosity of 250-350mPa & S, solid content of 20-40%) in a ratio of 5: 8, uniformly mixing, ultrasonically oscillating for 1min, and naturally drying the mixed solution in a culture dish to obtain a CMC-Na/CdS @ ZnS flexible quantum dot film; wherein the thickness of the film is 0.14 mm.
Example 4
A method for preparing a CMC-Na/CdS @ ZnS flexible quantum dot film comprises the following steps:
(1) preparing CMC-Na/CdS @ ZnS quantum dot dispersion liquid
Dissolving 0.03g of sodium carboxymethylcellulose in 50mL of water, and stirring at room temperature to completely dissolve the sodium carboxymethylcellulose; adjusting pH to 8 with dilute sodium hydroxide solution (concentration of 0.1M) to obtain sodium carboxymethylcellulose solution; then adding 1mL of cadmium chloride solution (0.02M) into the sodium carboxymethylcellulose solution, ultrasonically oscillating for 15min, and stirring (250rpm) at 50 ℃ in a nitrogen atmosphere to react for 2 h; after the reaction was complete, 1mL of sodium sulfide solution (0.04M) was added at a rate of 0.1 mL/min; after stirring for 2min, adding 1mL of zinc nitrate solution (0.04M) and 1mL of sodium sulfide solution (0.04M) at the rate of 0.2mL/min alternately in sequence, and reacting for 5min at 50 ℃; after the reaction is finished, obtaining CMC-Na/CdS @ ZnS quantum dot dispersion liquid;
(2) preparation of CMC-Na/CdS @ ZnS flexible quantum dot film
Heating and concentrating the CMC-Na/CdS @ ZnS quantum dot dispersion liquid at 60 ℃ to 1/3 with the original mass to obtain a concentrated liquid; mixing the concentrated solution and the aqueous polyurethane emulsion (viscosity of 250-350mPa & S, solid content of 20-40%) in a ratio of 5: 8, uniformly mixing, ultrasonically oscillating for 1min, and naturally drying the mixed solution in a culture dish to obtain a CMC-Na/CdS @ ZnS flexible quantum dot film; wherein the thickness of the film is 0.14 mm.
The CMC-Na/CdS @ ZnS flexible quantum dot dispersion obtained in examples 1 to 4 was tested, and the test results are shown in FIG. 2 and Table 1:
TABLE 1 Performance testing of CMC-Na/CdS @ ZnS Flexible Quantum dot dispersions obtained in examples 1-4
| Example (b) | Maximum emission wavelength (nm) | Luminous intensity (a.u.) |
| Example 1 | 620 | 517094.041 |
| Example 2 | 590 | 330769.606 |
| Example 3 | 690 | 380184.243 |
| Example 4 | 730 | 286535.260 |
As can be seen from fig. 2: with Na2And the concentration of S and ZnS is increased, the maximum emission wavelength of the CMC-Na/CdS @ ZnS quantum dot dispersion is gradually red-shifted, and the emission color is changed from yellow to red.
Example 5
The mass ratio of the concentrated solution to the aqueous polyurethane emulsion in the step (2) in the example 1 is adjusted to 5: and 6, keeping the balance consistent with that of the example 1 to obtain the CMC-Na/CdS @ ZnS flexible quantum dot film.
Comparative example 1
The mass ratio of the concentrated solution to the aqueous polyurethane emulsion in the step (2) in the example 1 is adjusted to 5: and 2, keeping the balance consistent with the example 1 to obtain the CMC-Na/CdS @ ZnS flexible quantum dot film.
Comparative example 2
The mass ratio of the concentrated solution to the aqueous polyurethane emulsion in the step (2) in the example 1 is adjusted to 5: and 4, keeping the consistency with the example 1 to obtain the CMC-Na/CdS @ ZnS flexible quantum dot film.
Comparative example 3
The mass ratio of the concentrated solution to the aqueous polyurethane emulsion in the step (2) in the example 1 is adjusted to 5: and (16) keeping the consistency with the example 1 to obtain the CMC-Na/CdS @ ZnS flexible quantum dot film.
Comparative example 4
Naturally drying the aqueous polyurethane emulsion in a culture dish to obtain a pure aqueous polyurethane film; wherein the thickness of the film is 0.14 mm.
The CMC-Na/CdS @ ZnS flexible quantum dot films obtained in examples 1 and 5 and comparative examples 1 to 4 (mass ratios of CMC-Na to solute in examples 1 and 5 and comparative examples 1, 2, 3 and 4 were 0.37 wt%, 0.50 wt%, 1.50 wt%, 0.74 wt%, 0.19 wt%, 0, respectively) were tested;
wherein, the calculation process of the ratio is as follows:
CMC-Na(wt％)＝mCMC-Na/(mCMC-Na+mPUsolid content).
The test results were as follows:
table 2 performance testing of quantum dot films
As can be seen from table 2 and fig. 3, 4, 6:
(1) as the CMC-Na concentration is reduced, the emission wavelength of the CMC-Na/CdS @ ZnS flexible quantum dot film is kept unchanged, but the luminous intensity is increased, and the luminous intensity is 66503.762 when the concentration is 0.37%.
(2) The transmission of the pure polyurethane film was approximately 85.81%. The transmittance of the CMC-Na/CdS @ ZnS flexible quantum dot film is increased along with the reduction of the concentration of CMC-Na;
(3) the elongation at break of the pure polyurethane film is 887.1%, and the elongation at break of the CMC-Na/CdS @ ZnS flexible quantum dot film gradually increases along with the decrease of the CMC-Na concentration. The elongation at break was about 730.6% at a CMC-Na concentration of 0.37%.
(4) As the CMC-Na concentration decreases, the luminescence intensity and the mechanical strength of the quantum dot film increase simultaneously.
FIG. 5 is an SEM topography of CMC-Na/CdS @ ZnS flexible quantum dot films with different concentrations. As can be seen from fig. 5: when the CMC-Na concentration is too high, the surface of the CMC-Na/CdS @ ZnS flexible quantum dot film is incomplete, a plurality of fractures are distributed, the surface fractures are gradually reduced along with the reduction of the CMC-Na concentration, and when the CMC-Na concentration ratio is 0.37%, the complete film with a better cross section form can be formed.
Table 3 shows the fluorescence intensity of the CMC-Na/CdS @ ZnS flexible quantum dot film of example 1 at different tensile elongations. As can be seen from table 3: the fluorescence intensity decreases with increasing tensile elongation.
TABLE 3 fluorescence intensity of CMC-Na/CdS @ ZnS flexible quantum dot film of example 1 at different tensile elongations
| Tensile elongation | Intensity of |
| 100％ | 17725.593 |
| 150％ | 12355.946 |
| 200％ | 10429.737 |
| 250％ | 8967.859 |
| 300％ | 6855.372 |
FIG. 7 is a luminescence diagram of CMC-Na/CdS @ ZnS flexible quantum dot films with different concentrations. As can be seen from fig. 7: the color of the CMC-Na/CdS @ ZnS flexible quantum dot film gradually becomes lighter from dark yellow to light yellow along with the reduction of the CMC-Na concentration, and the color of the film is no longer yellow when the CMC-Na concentration is reduced to 0.19 percent.
FIG. 8 shows the thermal stability test results of CMC-Na/CdS @ ZnS flexible quantum dot films with different concentrations, and it can be seen from FIG. 8 that: after polyurethane is added, the thermal stability of the film is greatly improved, and the thermal stability of the polyurethane added with different qualities is similar.
Comparative example 5
And (2) adjusting the sodium carboxymethylcellulose in the step (1) of the embodiment 1 to be sodium carboxymethylcellulose (CNC-Na) and Cellulose Nanofibers (CNFs), and keeping the balance of the method and the embodiment 1 to obtain the CMC-Na/CdS @ ZnS flexible quantum dot film.
The sodium carboxymethylcellulose is replaced by sodium carboxymethylcellulose and cellulose nanofibers, and in the experimental process, the following results are found:
(1) compared with CMC-Na, the stability of sodium carboxymethylcellulose and cellulose nanofibers in a dispersion (a dispersion obtained by adding cadmium chloride after the sodium carboxymethylcellulose (CNC-Na) and the Cellulose Nanofibers (CNFs) are dissolved in water) is poor, the sodium carboxymethylcellulose and the cellulose nanofibers are difficult to serve as polyelectrolyte salt to play a role in charge balance, and the solution is easily turbid in the process of synthesizing the quantum dot dispersion;
(2) when the mass ratio of the sodium carboxymethyl cellulose to water is 0.03:50, the sodium carboxymethyl cellulose is well dissolved, but the sodium carboxymethyl cellulose and the cellulose nano-fiber are difficult to dissolve, so that the experiment difficulty is increased;
(3) from the economic point of view, the price of the sodium carboxymethylcellulose is much cheaper than the rest two and has more cost performance (CMC-Na: about 0.07 yuan/g, CNC-Na: about 10 yuan/g and CNFs: about 4 yuan/g).
Therefore, sodium carboxymethylcellulose is selected as polyelectrolyte salt to synthesize the CMC-Na/CdS @ ZnS flexible quantum dot film.
Comparative example 6
The dosage of the sodium carboxymethylcellulose in the step (1) of the embodiment 1 is adjusted to be 15mg and 40mg, and the other dosage is consistent with that of the embodiment 1, so that the CMC-Na/CdS @ ZnS flexible quantum dot film is obtained.
As a result, it was found that: CMC-Na as polyelectrolyte salt, if the concentration is too low, can't play the role of maintaining the charge balance of solution system. In contrast, if the concentration is too high, the anion carried on the main chain of the sodium carboxymethyl cellulose is mixed with the anionic aqueous polyurethane, and the electrostatic interaction of the whole system is increased due to too high ionic strength, so that a normal film cannot be formed (as can be seen from the CMC-Na/CdS @ ZnS flexible quantum dot film SEM figure 5).
Comparative example 7
The CMC-Na/CdS @ ZnS flexible quantum dot film was obtained by adjusting the concentration to 1/5, 1/10 of the original mass in the step (2) of example 1, and keeping the other properties consistent with those of example 1.
As a result, it was found that: when the concentration multiple is too high, the concentration of CMC-Na can also be greatly increased, so that the electrostatic interaction in the system is increased, the coagulation phenomenon is generated, and a normal film can not be formed.
Comparative example 8
The concentration in the step (2) of the embodiment 1 is omitted, CMC-Na/CdS @ ZnS quantum dot dispersion liquid and polyurethane emulsion are directly mixed, and the rest is consistent with the embodiment 1, so that the CMC-Na/CdS @ ZnS flexible quantum dot film is obtained.
As a result, it was found that: the fluorescence intensity of the film was insufficient and was about 8X 104And the fluorescence intensity is far lower than that of the quantum dot film prepared after concentration.
Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (10)
1. A method for preparing a CMC-Na/CdS @ ZnS flexible quantum dot film is characterized by comprising the following steps:
(1) preparing CMC-Na/CdS @ ZnS quantum dot dispersion liquid
Dissolving sodium carboxymethylcellulose in water, and adjusting pH to 8-8.5 to obtain sodium carboxymethylcellulose solution; then adding a cadmium source solution into the sodium carboxymethyl cellulose solution, and reacting for 2-3h at 50-60 ℃ in an inert gas atmosphere; adding a sulfur source solution after the reaction is finished, and uniformly mixing; alternately adding zinc source solution and sulfur source solution, and reacting at 50-60 deg.C for 2-5 min; after the reaction is finished, obtaining CMC-Na/CdS @ ZnS quantum dot dispersion liquid;
(2) preparation of CMC-Na/CdS @ ZnS flexible quantum dot film
Concentrating the CMC-Na/CdS @ ZnS quantum dot dispersion liquid to 1/3-1/4 to obtain a concentrated liquid; and mixing the concentrated solution with polyurethane emulsion, and drying to obtain the CMC-Na/CdS @ ZnS flexible quantum dot film.
2. The method according to claim 1, wherein the mass ratio of the concentrated solution in the step (2) to the polyurethane emulsion is 5: 6-8.
3. The method of claim 1, wherein the sulfur source solution of step (1) comprises one of a sodium sulfide solution and a thiourea solution, wherein the concentration of the sulfur source solution is 0.01-0.04M.
4. The method of claim 1, wherein the zinc source solution of step (1) comprises one of a zinc nitrate solution, zinc sulfate; wherein the concentration of the zinc source solution is 0.01-0.04M.
5. The method of claim 1, wherein the concentration ratio of the cadmium source solution, the sulfur source solution and the zinc source solution in step (1) is 1: 1; the adding volume ratio of the cadmium source solution, the first sulfur source adding solution, the zinc source solution and the second sulfur source adding solution is 1: 1: 1: 1.
6. the method of claim 1, wherein the cadmium source solution of step (1) comprises one of a cadmium chloride solution, a cadmium acetate solution; wherein the concentration of the cadmium source solution is 0.02M.
7. The method as claimed in claim 1, wherein the polyurethane emulsion in step (2) is an aqueous polyurethane emulsion having a viscosity of 300-350mPa · S and a solid content of 20-40% (mass percent).
8. The method according to claim 1, wherein the ratio of the sodium carboxymethylcellulose in the sodium carboxymethylcellulose solution in step (1) to the water is 0.02-0.04 g: 50 mL.
9. CMC-Na/CdS @ ZnS flexible quantum dot film produced by the method of any one of claims 1 to 8.
10. Use of the CMC-Na/CdS @ ZnS flexible quantum dot film of claim 9 in displays, LEDs.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103436111A (en) * | 2013-07-29 | 2013-12-11 | 复旦大学 | Preparation method of water-based ultraviolet barrier coating based on ZnO quantum dots |
| CN103709731A (en) * | 2013-12-27 | 2014-04-09 | Tcl集团股份有限公司 | Quantum dot/polyurethane nano crystal complex and preparation method thereof as well as colorful conversion film |
| US20150021551A1 (en) * | 2011-11-22 | 2015-01-22 | Qd Vision, Inc. | Methods for coating semiconductor nanocrystals |
| CN105085999A (en) * | 2015-08-07 | 2015-11-25 | 复旦大学 | Biocompatible quantum dot light-emitting film and preparation method thereof |
| WO2018095442A1 (en) * | 2016-11-22 | 2018-05-31 | 华南农业大学 | Quantum dot and use of composite material thereof in preparing ultraviolet resistant products |
| US20180151884A1 (en) * | 2016-11-28 | 2018-05-31 | Sila Nanotechnologies Inc. | High-capacity battery electrodes with improved binders, construction, and performance |
| CN110044884A (en) * | 2019-04-11 | 2019-07-23 | 华南理工大学 | A kind of Test paper of divalent manganesetion and the preparation method and application thereof |
| CN113073369A (en) * | 2021-03-31 | 2021-07-06 | 武汉理工大学 | Silver nano-cluster/carboxymethyl cellulose membrane with fluorescence property and preparation method thereof |
| CN113292749A (en) * | 2021-03-16 | 2021-08-24 | 华南农业大学 | Fluorescent blotting membrane for in-situ visual detection of root exudates and preparation and application thereof |
| CN113480998A (en) * | 2021-08-19 | 2021-10-08 | 河南师范大学 | Preparation method based on bottom-up fluorescent sulfur quantum dots |
-
2022
- 2022-05-10 CN CN202210505175.2A patent/CN114736669B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150021551A1 (en) * | 2011-11-22 | 2015-01-22 | Qd Vision, Inc. | Methods for coating semiconductor nanocrystals |
| CN103436111A (en) * | 2013-07-29 | 2013-12-11 | 复旦大学 | Preparation method of water-based ultraviolet barrier coating based on ZnO quantum dots |
| CN103709731A (en) * | 2013-12-27 | 2014-04-09 | Tcl集团股份有限公司 | Quantum dot/polyurethane nano crystal complex and preparation method thereof as well as colorful conversion film |
| CN105085999A (en) * | 2015-08-07 | 2015-11-25 | 复旦大学 | Biocompatible quantum dot light-emitting film and preparation method thereof |
| WO2018095442A1 (en) * | 2016-11-22 | 2018-05-31 | 华南农业大学 | Quantum dot and use of composite material thereof in preparing ultraviolet resistant products |
| US20180151884A1 (en) * | 2016-11-28 | 2018-05-31 | Sila Nanotechnologies Inc. | High-capacity battery electrodes with improved binders, construction, and performance |
| CN110044884A (en) * | 2019-04-11 | 2019-07-23 | 华南理工大学 | A kind of Test paper of divalent manganesetion and the preparation method and application thereof |
| CN113292749A (en) * | 2021-03-16 | 2021-08-24 | 华南农业大学 | Fluorescent blotting membrane for in-situ visual detection of root exudates and preparation and application thereof |
| CN113073369A (en) * | 2021-03-31 | 2021-07-06 | 武汉理工大学 | Silver nano-cluster/carboxymethyl cellulose membrane with fluorescence property and preparation method thereof |
| CN113480998A (en) * | 2021-08-19 | 2021-10-08 | 河南师范大学 | Preparation method based on bottom-up fluorescent sulfur quantum dots |
Non-Patent Citations (1)
| Title |
|---|
| ALEXANDRA A. P. MANSUR等: "Composition-Tunable Optical Properties of ZnxCd(1-x)S Quantum Dot– Carboxymethylcellulose Conjugates: Towards One-Pot Green Synthesis of Multifunctional Nanoplatforms for Biomedical and Environmental Applications", 《NANOSCALE RESEARCH LETTERS》 * |
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