CN116574435A

CN116574435A - Preparation method of water-based fluorescent paint based on nanoparticle composite

Info

Publication number: CN116574435A
Application number: CN202310527954.7A
Authority: CN
Inventors: 吉邢虎; 陈扬琪; 赵雅诗; 何治柯
Original assignee: Wuhan University WHU
Current assignee: Wuhan University WHU
Priority date: 2023-05-10
Filing date: 2023-05-10
Publication date: 2023-08-11

Abstract

The invention discloses a preparation method of a water-based fluorescent paint based on nanoparticle compounding, which comprises the steps of preparing nano fluorescent carbon dots or nano fluorescent silicon dots, and then diluting to obtain nano fluorescent carbon dot dispersion liquid or nano fluorescent silicon dot dispersion liquid; and mixing the nano fluorescent carbon dot dispersion liquid or the nano fluorescent silicon dot dispersion liquid with the water-based paint according to the volume ratio of 3:1-1:18 to obtain the nano particle composite water-based fluorescent paint. According to the invention, two nano fluorescent carbon dots and one nano fluorescent silicon dot are prepared, and the fluorescent intensity of the nano fluorescent carbon dots and the nano fluorescent silicon dot is optimized by regulating and controlling the proportion of the preparation precursors of the nano materials; the water-based fluorescent paint is prepared by further mixing the nano fluorescent carbon dots and the nano fluorescent silicon dots with water-based polyurethane and water-based polyacrylic acid, and has the advantages of good compatibility and high stability, and has wide application prospect.

Description

Preparation method of water-based fluorescent paint based on nanoparticle composite

Technical Field

The invention relates to the technical field of water-based fluorescent paint, in particular to a preparation method of water-based fluorescent paint based on nanoparticle compounding.

Background

In recent years, fluorescent nanomaterials have been widely used in different fields, but fluorescent nanomaterials based on carbon dots and silicon dots are favored by many researchers because of their outstanding optical properties, water solubility, non-toxicity and other characteristics.

At present, the common industrial paint is an organic solvent paint, and a large amount of Volatile Organic Compounds (VOCs) can be released in the use process, so that the paint not only causes serious harm to the health of people, but also causes damage to the ecological environment. The water-based paint is a paint which takes water as a dispersion medium, and has the most outstanding advantage of low VOCs content compared with the conventional oil-based paint. Today, the green chemistry concept is deep, the water-based paint is developed at a high speed, and researches show that the market selling ratio of the water-based paint in the residential field is over 80 percent, which is far over that of the oil-based paint. The gradual replacement of oily coatings by aqueous coatings has become a necessary trend.

With the development of the building industry, the common paint can not meet different demands in life, various functional paints are appeared on the market, and the fluorescent paint is one of the functional paints and has wide application value in the fields of road safety, building decoration, file anti-counterfeiting and the like. The water-based fluorescent paint is mainly prepared by adding special fluorescent auxiliary agents into the paint, and most of the water-based fluorescent paint is obtained by blending organic or inorganic micromolecular dye with resin, which tends to bring about a plurality of problems. On the one hand, the fluorescence of the small molecules is derived from the conjugated structure, so that the hydrophilicity is generally poor, and proper dispersing agents and proper dispersing processes are needed to be selected; on the other hand, the small molecules are easy to migrate to the surface of the material to cause falling in the processes of placing, washing, dry cleaning, using and the like; finally, there are some small fluorescent molecules and even harm to the human body.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a preparation method of the water-based fluorescent paint based on nanoparticle composite, which is based on the improvement of the storage stability and the fluorescence effect of the water-based fluorescent paint and the reduction of the preparation cost to meet the requirement of mass production,

preparing nano fluorescent carbon dots or nano fluorescent silicon dots, and then diluting to obtain nano fluorescent carbon dot dispersion liquid or nano fluorescent silicon dot dispersion liquid;

and mixing the nano fluorescent carbon dot dispersion liquid or the nano fluorescent silicon dot dispersion liquid with the water-based paint according to the volume ratio of 3:1-1:18 to obtain the nano particle composite water-based fluorescent paint.

Further, the preparation of the nano-fluorescent carbon dots includes,

the diethylenetriamine pentamethylene phosphonic acid and m-phenylenediamine are dissolved in water, and then the temperature is raised for reaction.

Further, the mass ratio of the diethylenetriamine pentamethylene phosphonic acid to the m-phenylenediamine is 1:10-9:1.

Further, the preparation of the nano-fluorescent carbon dots includes,

NaOH and rhodamine B are dissolved in water, and then the temperature is raised for reaction.

Further, the mass ratio of the NaOH to the rhodamine B is 1:2-8:1.

Further, the preparation of the nano-fluorescent silicon dots comprises,

n- [3- (trimethoxysilyl) propyl ] ethylenediamine and catechol were dissolved in water, followed by a reaction at elevated temperature.

Further, the mass ratio of the N- [3- (trimethoxysilyl) propyl ] ethylenediamine to the catechol is 1:1-250:1.

Further, the temperature of the temperature-rising reaction is 180-200 ℃ and the time is 4-9 h.

Further, the aqueous coating comprises aqueous polyurethane and aqueous polyacrylic acid.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, two nano fluorescent carbon dots and one nano fluorescent silicon dot are prepared, and the fluorescent intensity of the nano fluorescent carbon dots and the nano fluorescent silicon dot is optimized by regulating and controlling the proportion of the preparation precursors of the nano materials; the water-based fluorescent paint is prepared by further mixing the nano fluorescent carbon dots and the nano fluorescent silicon dots with water-based polyurethane and water-based polyacrylic acid, and has the advantages of good compatibility and high stability, and has wide application prospect.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the steps particularly pointed out in the written description and drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 shows a graph of the fluorescence effect of 0.5mg/L of a-CDs dispersion and a-CDs@PU fluorescent paint under natural light and 365nm ultraviolet light in an embodiment of the invention;

FIG. 2A shows the color development performance of a-CDs@PU fluorescent film containing different a-CDs concentrations in the embodiment of the invention under natural light, and FIG. 2B shows the color development performance of a-CDs@PU fluorescent film containing different a-CDs concentrations in the embodiment of the invention under 365nm ultraviolet irradiation; FIG. 2C shows the color development effect of an a-CDs@PAA fluorescent film under 365nm ultraviolet light in an embodiment of the invention;

FIG. 3A shows the color development state of the a-CDs@PU fluorescent film prepared by different volume ratios of a-CDs to PU in the embodiment of the invention in natural light; FIG. 3B shows the color development state of the a-CDs@PU fluorescent film prepared by different volume ratios of a-CDs to PU in the embodiment of the invention under 365nm ultraviolet light;

FIG. 4A shows a graph of the fluorescence effect of the a-CDs@PU fluorescent film of the embodiment of the invention under different pH environments; FIG. 4B shows a graph of the fluorescence effect of the a-CDs@PU fluorescent film of the embodiment of the invention in sodium chloride solutions with different concentrations;

FIG. 5 shows a graph of the fluorescence effect of the a-CDs@PU fluorescent film of the embodiment of the invention under hydrogen peroxide solutions with different concentrations;

FIG. 6 shows the results of a photo-bleaching resistance experiment of a fluorescent film of an example a-CDs@PU of the invention;

FIG. 7 is a graph showing the fluorescence effect of a b-CDs dispersion at a concentration of 0.5mg/L with a b-CDs@PU fluorescent coating under natural light and 365nm ultraviolet light in an embodiment of the present invention;

FIG. 8A shows the color development performance of B-CDs@PU fluorescent films with different B-CDs concentrations in the embodiment of the invention under natural light, and FIG. 8B shows the color development performance of B-CDs@PU fluorescent films with different B-CDs concentrations in the embodiment of the invention under 365nm ultraviolet light;

FIG. 9 is a graph showing the fluorescence effect of Si-CDs dispersion at a concentration of 0.5mg/L with Si-CDs@PU fluorescent paint under natural light and 365nm ultraviolet light in an embodiment of the present invention;

FIG. 10A shows the color development performance of Si-CDs@PU fluorescent films with different Si-CDs concentrations in the embodiment of the invention under natural light, and FIG. 10B shows the color development performance of Si-CDs@PU fluorescent films with different Si-CDs concentrations in the embodiment of the invention under 365nm ultraviolet light.

Detailed Description

The endpoints of the ranges and any values disclosed in the present invention are not limited to the precise range or value, and the range or value should be understood to include values close to the range or value. For numerical ranges, one or more new numerical ranges may be obtained in combination with each other between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point values, and are to be considered as specifically disclosed in the present invention.

The following description of specific embodiments of the present invention and the accompanying drawings will provide a clear and complete description of the technical solutions of embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Abbreviation interpretation in the examples:

DAP: diethylenetriamine pentamethylenephosphonic acid;

DAMO: n- [3- (trimethoxysilyl) propyl ] ethylenediamine;

a-CDs: nano fluorescent carbon dots prepared in example 1 to example 19;

b-CDs: nano fluorescent carbon dots prepared in examples 20 to 25;

SiDs: nano fluorescent silicon dots prepared in examples 26 to 31;

PU: aqueous polyurethane;

PAA: aqueous polyacrylic acid.

Examples 1 to 6

The preparation method of the water-based fluorescent paint based on nanoparticle composite, wherein the nanoparticles are a-CDs. The raw material proportioning table is shown in table 1.

Table 1 raw material blending tables of examples 1 to 6

Examples 1 to 4 and example 6 differ from example 5 only in the mass of DAP. The preparation method of the examples can refer to the example 5, and comprises the following steps:

adding 0.5g of m-phenylenediamine and 3.0g of DAP into 30mL of deionized water at room temperature, dissolving by 100W ultrasonic, putting into a 50mL of polytetrafluoroethylene high-temperature reaction kettle, transferring into a 200 ℃ oven for reaction for 5 hours, and naturally cooling the room temperature to obtain a-CDs;

loading the a-CDs obtained in the step one into a centrifuge tube, centrifuging for 3 times at a speed of 8000r/min for 5min each time, taking supernatant and respectively diluting with deionized water to obtain a-CDs dispersion liquid with the concentration of 100mg/L, 200mg/L, 300mg/L, 400mg/L, 500mg/L, 600mg/L, 700mg/L, 800mg/L, 900mg/L and 1000 mg/L;

and step three, adding 4mL of the a-CDs dispersion liquid obtained in the step two into 36mL of PU respectively, and mixing for 10min under 200W ultrasonic power to obtain clear yellow solution, thus obtaining the a-CDs@PU fluorescent coating.

Examples 7 to 13

Examples 7 to 13 were prepared in substantially the same manner as in example 5 except that the volume ratio of a-CDs to PU was different as shown in Table 2.

TABLE 2 volume ratio of a-CDs to PU volume ratios in examples 7 to 13

	Volume ratio of a-CDs to PU
		Example 5	1:9
Example 7	3:1
		Example 8	1:1
Example 9	1:3
		Example 10	1:6
Example 11	1:12
		Example 12	1:15
Example 13	1:18

Examples 14 to 19

Examples 14 to 19 were prepared in substantially the same manner as in examples 1 to 6, except that PU was replaced with PAA. The raw material ingredients are shown in Table 3

Table 3 raw material blending tables of examples 7 to 12

Comparative example 1

Comparative example 1 was prepared in substantially the same manner as in reference to example 5 except that DAP was not added.

Comparative example 2

Comparative example 2 was prepared in substantially the same manner as in reference to example 5 except that metaphenylene diamine was not added.

Test example 1

To investigate the properties of the a-CDs dispersions of examples 1 to 6, fluorescence spectra of these materials and comparative examples 1 and 2 were measured at a concentration of 0.5mg/L, and excitation wavelength, emission wavelength and fluorescence intensity were characterized, and the results are shown in Table 4.

TABLE 4 characterization of fluorescence spectrograms

As can be seen from the results in Table 4, when the mass ratio of DAP to m-phenylenediamine is 1:6, the prepared a-CDs dispersion has the best fluorescence performance.

The a-CDs dispersion in example 5 was diluted with a-CDs@PU fluorescent coating to a-CDs concentration of 0.5mg/L and its fluorescence spectrum was characterized. The result shows that the maximum fluorescence excitation peak of the a-CDs dispersion liquid is 440nm, and the maximum fluorescence emission peak is 512nm; the maximum fluorescence excitation peak of the a-CDs@PU fluorescent coating is 460nm, the maximum fluorescence emission peak is 502nm, and the fluorescence intensity of the a-CDs dispersion liquid and the fluorescence intensity of the a-CDs@PU fluorescent coating are not obviously different. This shows that the excitation emission wavelength is slightly shifted after the a-CDs are compounded with PU, but the fluorescence intensity is not affected. FIG. 1 shows a graph of the fluorescence effect of the a-CDs dispersion (B) and the a-CDs@PU fluorescent coating (A) of example 5 under natural light (left of FIG. 1) and 365nm ultraviolet light (right of FIG. 1).

To investigate the effect of the initial concentration of a-CDs on the performance of a-CDs@PU fluorescent paint, 100mg/L, 200mg/L, 300mg/L, 400mg/L, 500mg/L, 600mg/L, 700mg/L, 800mg/L, 900mg/L and 1000mg/L of a-CDs dispersion in example 5 was added to PU at a volume ratio of 1:9 to give a-CDs fluorescent paint having a-CDs concentration of 10mg/L, 20mg/L, 30mg/L, 40mg/L, 50mg/L, 60mg/L, 70mg/L, 80mg/L, 90mg/L and 100mg/L, and the a-CDs@PU fluorescent films of 2cm×2cm×1mm were produced by adding these fluorescent paints to a silicone mold, and the results were shown in FIG. 2A and FIG. 2B, respectively. As can be seen from FIG. 2A, the a-CDs@PU fluorescent films with different a-CDs concentrations show brown yellow color under natural light, and the color is deepened along with the increase of the a-CDs concentration; as can be seen from FIG. 2B, the a-CDs@PU fluorescent films with different a-CDs concentrations show blue-green fluorescence under 365nm ultraviolet irradiation, and have the best fluorescence effect when the a-CDs concentration in the a-CDs@PU fluorescent film is 70 mg/L. FIG. 2C is a graph showing the color development effect of the a-CDs@PAA fluorescent film prepared in example 18 and having a-CDs concentration of 70mg/L, wherein the left side of FIG. 2C shows the color development effect of the a-CDs@PAA fluorescent film under natural light; the right side of FIG. 2C shows the color development effect of a-CDs@PAA fluorescent film (a-CDs concentration of 70 mg/L) under 365nm ultraviolet light.

To investigate the effect of the volume ratio of a-CDs dispersion to PU on the performance of a-CDs@PU fluorescent paint, a-CDs@PU fluorescent paint prepared in example 5 and example 7 to example 13 was added to a silica gel mold to prepare a 2cm×2cm×1mm a-CDs@PU fluorescent film (the concentration of a-CDs is 70 mg/L), and the state thereof under natural light and 365nm ultraviolet light was observed, and the results are shown in FIG. 3A and FIG. 3B, respectively. As can be seen from FIG. 3A, when the volume ratio of the a-CDs dispersion liquid to the PU is 3:1-1:6, the a-CDs@PU fluorescent film is dark brown in color and poor in transmittance; as can be seen from FIG. 3B, the fluorescence intensity of the a-CDs dispersion liquid and PU is weaker in the volume ratio of 1:12-1:18, and the volume ratio of the a-CDs dispersion liquid and PU has good transmittance and stronger fluorescence intensity in the volume ratio of 1:9.

To examine the stability of the a-CDs@PU fluorescent film prepared in example 5 (a-CDs concentration of 70 mg/L) was placed in an acidic, alkaline, salt solution and oxidizing agent environment (the a-CDs@PU fluorescent film was taken out after being immersed in the corresponding solution for 30 min), the change in fluorescence intensity was observed, and a photo-bleaching resistance experiment was also performed. FIG. 4A shows the fluorescence properties of the a-CDs@PU fluorescent film at an environmental pH of 1 to 12, and it can be seen that the stability of the a-CDs@PU fluorescent film is good at an environmental pH of 3 to 11. FIG. 4B shows a graph of fluorescence effects at sodium chloride solutions at concentrations of 0.5M, 1M, 1.5M, and 2M, and it can be seen that the sodium chloride solution at 2M does not have an effect on the fluorescence properties of the a-CDs@PU fluorescent film. FIG. 5 shows a graph of the fluorescence effect at hydrogen peroxide solutions at concentrations of 0, 0.01M, 0.1M and 1M, it being seen that the hydrogen peroxide solution at 1M does not have a significant effect on the fluorescence properties of the a-CDs@PU fluorescent film. FIG. 6 shows a graph of fluorescence effect after 5 hours under natural light, 365nm ultraviolet light and light-shielding conditions, and shows that the a-CDs@PU fluorescent film has good photobleaching resistance.

Examples 20 to 25

The preparation method of the water-based fluorescent paint based on nanoparticle composite, wherein the nanoparticles are b-CDs. The raw material proportioning table is shown in table 5.

Table 5 raw material blending tables of examples 20 to 25

Examples 20 to 22, example 24 and example 25 differ only in the mass of NaOH from example 23. The preparation method of the examples can refer to the example 23, and comprises the following steps:

step one, adding 100mg of rhodamine B and 400mg of NaOH into 15mL of deionized water at room temperature, performing ultrasonic dissolution through 100W, placing into a 50mL of polytetrafluoroethylene high-temperature reaction kettle, transferring into a 180 ℃ oven for reaction for 8 hours, and naturally cooling the room temperature to obtain B-CDs;

respectively diluting the b-CDs obtained in the step one with deionized water to obtain b-CDs dispersion liquid with the concentration of 100mg/L, 200mg/L, 300mg/L, 400mg/L, 500mg/L, 600mg/L, 700mg/L, 800mg/L, 900mg/L and 1000 mg/L;

and step three, respectively adding 4mL of the b-CDs dispersion liquid obtained in the step two into 36mL of PU, and mixing for 10min under 200W ultrasonic power to obtain a clear light green solution, thus obtaining the b-CDs@PU fluorescent coating.

Comparative example 3

Comparative example 3 was prepared in substantially the same manner as in reference example 23 except that rhodamine B was not added.

Comparative example 4

Comparative example 2 was prepared in substantially the same manner as in reference example 23 except that NaOH was not added.

Test example 2

To investigate the properties of the b-CDs dispersions of examples 20 to 25, fluorescence spectra of these materials and comparative examples 3 and 4 were measured at a concentration of 0.5mg/L, and excitation wavelength, emission wavelength and fluorescence intensity were characterized, and the results are shown in Table 6.

TABLE 6 characterization of fluorescence spectrograms

Although comparative example 4 had the highest fluorescence intensity, it had poor fluorescence stability because rhodamine B was not highly stable in molecular fluorescence after the reaction. As can be seen from the results of Table 6, the prepared B-CDs dispersion had the best fluorescence properties when the mass ratio of NaOH to rhodamine B was 4.

The b-CDs dispersion in example 23 was diluted with b-CDs@PU fluorescent paint to give a b-CDs concentration of 0.5mg/L and its fluorescence spectrum was characterized. The result shows that the maximum fluorescence excitation peak of the b-CDs dispersion liquid is 490nm, and the maximum fluorescence emission peak is 515nm; the maximum fluorescence excitation peak of the prepared b-CDs@PU is 490nm, and the maximum fluorescence emission peak is 513nm; after the fluorescent dye is compounded with the aqueous polyurethane, the excitation emission wavelength has no obvious displacement, and the fluorescence intensity is not affected. FIG. 7 shows a graph of the fluorescence effect of the a-CDs dispersion (B) and a-CDs@PU fluorescent coating (A) of example 23 under natural light (left of FIG. 7) and ultraviolet light (right of FIG. 7).

To investigate the effect of the initial B-CDs dispersion concentration on the properties of the B-CDs@PU fluorescent paint, 100mg/L, 200mg/L, 300mg/L, 400mg/L, 500mg/L, 600mg/L, 700mg/L, 800mg/L, 900mg/L and 1000mg/L B-CDs dispersions of example 23 were added to PU at a volume ratio of 1:9 to give B-CDs fluorescent paint having B-CDs concentrations of 10mg/L, 20mg/L, 30mg/L, 40mg/L, 50mg/L, 60mg/L, 70mg/L, 80mg/L, 90mg/L and 100mg/L, and these fluorescent paint were added to a silica gel mold to give B-CDs@PU fluorescent films of 2cm×2cm×1mm, and the results thereof under natural light and 365nm ultraviolet light were shown in FIG. 8A and FIG. 8B, respectively. As can be seen from fig. 8A, the a-cds@pu fluorescent films with different b-CDs concentrations show colorless transparency and slightly yellow under natural light, and the yellow phenomenon becomes obvious with the increase of the b-CDs concentration but the whole still shows transparency; as can be seen from FIG. 8B, the a-CDs@PU fluorescent film with different a-CDs concentrations shows yellow-green fluorescence under 365nm ultraviolet irradiation, and has the best fluorescence effect when the B-CDs concentration in the B-CDs@PU fluorescent film is 70 mg/L.

Examples 26 to 31

The preparation method of the water-based fluorescent paint based on nanoparticle composite, wherein the nanoparticles are Si-CDs. The raw material proportioning table is shown in table 7.

Table 7 raw material blending tables of examples 26 to 31

Examples 26 to 29 and example 31 differ from example 30 only in the mass of the DAMO. The preparation method of these examples can refer to example 30, and includes the following steps:

adding 2200mg of DAMO and 11mg of catechol into 10mL of deionized water at room temperature, performing ultrasonic dissolution through 100W, placing into a 30mL of polytetrafluoroethylene high-temperature reaction kettle, transferring into a 200 ℃ oven for reaction for 4 hours, and naturally cooling the room temperature to obtain brown yellow Si-CDs;

and step two, filling the Si-CDs obtained in the step one into a 1000Da dialysis bag, placing the dialysis bag into a 200mL beaker containing 150mL deionized water, placing a magneton into the beaker, and placing the beaker on a magnetic stirrer to stir for 6 hours at normal temperature to obtain yellow SiDs. Diluting the yellow SiDs with deionized water to obtain SiDs dispersion liquid with mass concentrations of 50mg/L, 400mg/L and 750mg/L respectively;

and step three, respectively adding 4mL of SiDs dispersion liquid obtained in the step two into 36mL of PU, and mixing for 10min under 200W ultrasonic power to obtain a clear pale yellow solution, thus obtaining the b-CDs@PU fluorescent coating.

Comparative example 5

Comparative example 5 was prepared in substantially the same manner as in reference example 30 except that catechol was not added.

Comparative example 6

Comparative example 2 was prepared in substantially the same manner as in reference example 23 except that no DAMO was added.

Test example 3

To investigate the properties of the Si-CDs dispersions of examples 26 to 31, fluorescence spectra of these materials and comparative examples 5 and 6 were measured at a concentration of 0.5mg/L, and excitation wavelength, emission wavelength and fluorescence intensity were characterized, and the results are shown in Table 8.

TABLE 8 characterization of fluorescence spectrograms

As can be seen from the results of Table 8, the prepared Si-CDs dispersion had the best fluorescence properties when the mass ratio of DAMO to catechol was 200.

The SiDs dispersion prepared in example 30 and SiDs@PU fluorescent paint were diluted to a SiDs concentration of 0.5mg/L and the fluorescence spectrum thereof was characterized. The result shows that the maximum fluorescence excitation peak of the SiDs dispersion liquid is 440nm, and the maximum fluorescence emission peak is 515nm; the prepared SiDs@PU fluorescent paint has a maximum fluorescence excitation peak of 460nm and a maximum fluorescence emission peak of 500nm; after being compounded with the aqueous polyurethane, the excitation emission wavelength is slightly shifted, but the fluorescence intensity is not affected basically. FIG. 9 shows the fluorescence effect of SiDs dispersion (B) and SiDs@PU fluorescent paint (A) in example 30 under natural light (left of FIG. 9) and ultraviolet light (right of FIG. 9).

To investigate the effect of the initial concentration of the SiDs dispersion on the performance of SiDs@PU fluorescent paint, 50mg/L, 400mg/L, 750mg/L of SiDs dispersion in example 30 was added to PU at a volume ratio of 1:9 to obtain SiDs@PU fluorescent paint of 5mg/L, 40mg/L, 75mg/L, and these fluorescent paints were added to a silica gel mold to prepare SiDs@PU fluorescent films of 2cm×2cm×1mm, and the conditions under natural light and 365nm ultraviolet light were observed, and the results are shown in FIG. 10A and FIG. 10B, respectively. As can be seen from fig. 10A, the color of the sids@pu fluorescent film gradually deepens as the concentration of SiDs increases; as can be seen from FIG. 10B, the a-CDs@PU fluorescent films with different a-CDs concentrations show yellow-green fluorescence under 365nm ultraviolet irradiation, and the fluorescence effect of the SiDs@PU fluorescent films is obviously improved along with the increase of the SiDs concentration.

Finally, it should be noted that: the foregoing description is only illustrative of the preferred embodiments of the present invention, and although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described, or equivalents may be substituted for elements thereof, and any modifications, equivalents, improvements or changes may be made without departing from the spirit and principles of the present invention.

Claims

1. A preparation method of a water-based fluorescent paint based on nanoparticle composite is characterized by comprising the following steps of,

2. The method of claim 1, wherein preparing the nano-fluorescent carbon dots comprises,

3. The preparation method according to claim 2, wherein the mass ratio of the diethylenetriamine penta-methylene phosphonic acid to the m-phenylenediamine is 1:10-9:1.

4. The method of claim 1, wherein preparing the nano-fluorescent carbon dots comprises,

5. The preparation method according to claim 4, wherein the mass ratio of the NaOH to the rhodamine B is 1:2-8:1.

6. The method of claim 1, wherein preparing the nano-fluorescent silicon dots comprises,

7. The method according to claim 6, wherein the mass ratio of the N- [3- (trimethoxysilyl) propyl ] ethylenediamine to the catechol is 1:1 to 250:1.

8. The process according to any one of claims 2 to 7, wherein the temperature of the elevated temperature reaction is 180 to 200 ℃ for 4 to 9 hours.

9. The method of claim 1, wherein the aqueous coating comprises aqueous polyurethane and aqueous polyacrylic acid.