CN113321945A - Preparation method and application of carbon quantum dot regulated aluminum phosphite crystal - Google Patents

Abstract

Translated fromChinese

一种碳量子点调控亚磷酸铝晶体的制备方法及其应用，本发明属于纳米材料技术领域，本发明提供的一种碳量子点/亚磷酸铝复合材料的制备方法是在合成亚磷酸铝晶体的基础上，添加碳量子点进行表面修饰，再将其混合物通过洗涤去除多余碳量子点，最后干燥后得到粉末状固体，即碳量子点/亚磷酸铝复合材料。本发明有益效果在于：(1)所制备的纳米颗粒大小均匀，分布均匀，具有很好的水溶性。(2)该碳量子点/亚磷酸铝复合材料展现出较好分散性，作为涂料添加剂可以很好地分散在基质中，且具有抗老化和抗黄化的作用；(5)本发明制备方法操作简便，所需实验设备简易，生产成本低且周期短，应用性强。

A method for preparing carbon quantum dots regulated aluminum phosphite crystals and applications thereof, and the invention belongs to the technical field of nanomaterials. On the basis of , carbon quantum dots are added for surface modification, and the mixture is washed to remove excess carbon quantum dots, and finally a powdery solid is obtained after drying, that is, carbon quantum dots/aluminum phosphite composite material. The beneficial effects of the present invention are as follows: (1) The prepared nanoparticles are uniform in size, uniform in distribution, and have good water solubility. (2) The carbon quantum dot/aluminum phosphite composite material exhibits good dispersibility, can be well dispersed in the matrix as a coating additive, and has anti-aging and anti-yellowing effects; (5) The preparation method of the present invention The operation is simple, the required experimental equipment is simple, the production cost is low, the cycle is short, and the applicability is strong.

Description

Preparation method and application of carbon quantum dot regulated aluminum phosphite crystal

Technical Field

The invention belongs to the technical field of nano materials, and particularly relates to a preparation method and application of a carbon quantum dot regulated aluminum phosphite material.

Background

The carbon quantum dots are a zero-dimensional semiconductor nano material which is approximately spherical and has the diameter of less than 10nm, and the carbon quantum dots are nanoclusters formed by few molecules or atoms. Compared with quantum dots with larger particle size and molecular weight of hundreds of thousands, the particle size of the carbon dots is generally only a few nanometers, and the fluorescent carbon dots with molecular weight of thousands to tens of thousands are one of the hottest carbon nano-materials after fullerene, carbon nano-tube and graphene. The nano material overcomes some defects of the traditional quantum dots, has excellent optical performance and small-size characteristics, has good biocompatibility, is easy to realize surface functionalization, and has good application potential in the fields of biochemical sensing, imaging analysis, environmental detection, photocatalysis technology, ultraviolet absorption, surface reducing agent, structure regulation, medicine carrying and the like.

Since the first report of organic template method for synthesizing one-dimensional chain zinc phosphite in 2001, the reports about the phosphite microporous material are rare. The salt phosphate microporous materials reported so far contain many transition metal phosphites, such as one-dimensional, two-dimensional, three-dimensional zinc phosphite, organic template chromium fluorophosphite, inorganic-organic hybrid cobalt phosphite, three-dimensional iron phosphite, vanadium phosphite, and the like; and main group metal phosphites have been reported only rarely. Few studies have been made on aluminum phosphite which is excellent in fluidity, fire resistance, and the like. The aluminum phosphite is used as an excellent nontoxic antirust pigment, and can obviously improve the corrosion resistance, the antirust performance and the anti-bubble performance of the paint. The aluminum phosphite has good chemical stability and better whitening and opacifying properties, can partially replace zirconium silicate, and is widely used in the production of various building ceramics, sanitary ceramics, daily ceramics, first-class artware ceramics and the like; it is also a fluxing agent for manufacturing special glass, a binding agent for ceramics and teeth, and can be used as an additive for producing an emollient, a fire-proof coating, conductive cement and the like, an anti-fouling agent in textile industry, a catalyst in organic synthesis, and in addition, the glass is also used in the pharmaceutical industry and the paper industry.

As an important additive component, the improvement of uniformity and dispersibility of aluminum phosphite crystals facilitates the addition in more products. Carbon quantum dots are used as a structure inducer and an ultraviolet additive and are added in the process of synthesizing the phosphorous acid crystal, so that the final product has good dispersibility, uniform particles and ageing resistance. The composite material is easy to manufacture, has the advantages of high stability, complete uniformity, low toxicity and the like, and has wide application prospect. The composite material is mixed with commercial paint, mechanical stirring is carried out, inorganic glass, wood plates and iron plates are used as carriers, and a layer of coating is spin-coated on the surfaces of the inorganic glass, the wood plates and the iron plates, so that the composite material has the characteristics of good uniformity, ageing resistance and yellowing resistance. This suggests that the aluminum phosphite crystals may be an emerging class of additive materials for a variety of applications.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention mainly aims to provide a preparation method for regulating and controlling the dispersibility of phosphorous acid crystals by using carbon quantum dots; the method is simple, rapid, environment-friendly, safe and excellent in performance.

The invention also aims to provide the carbon quantum dot/aluminum phosphite composite material obtained by the preparation method.

The invention further aims to provide application of the carbon quantum dot/aluminum phosphite composite material.

The purpose of the invention is realized by the following technical scheme:

a process for preparing the carbon quantum dots/aluminium phosphite composite material includes such steps as adding carbon quantum dots to synthesize aluminium phosphite crystal, surface modification, washing to remove excess carbon quantum dots, and drying to obtain powdered solid. The preparation method specifically comprises the following steps:

(1) and (3) synthesis of carbon quantum dots:

citric acid and ethylenediamine were dissolved in double distilled water. Then transferring the solution into a reaction kettle, and reacting under heating condition until the reaction is finished. After the reaction, the reactor is cooled to room temperature by water or natural cooling. The product is brownish black and transparent, and is dialyzed to obtain the carbon quantum dots. The yield was about 58%.

The weight percentage of the citric acid is 6-10 wt%, and 8.8% is preferable;

the weight percentage of the ethylenediamine is 2-4 wt%, and the preferred weight percentage is 3 wt%;

the reaction kettle is a polytetrafluoroethylene lining reaction kettle.

The heating equipment can be a high-temperature oven, the heating temperature is 180-220 ℃, and the preferred temperature is 200 ℃;

the reaction heating time is 4-6h, preferably 5 h.

(2) Preparing a carbon quantum dot/aluminum phosphite composite material:

a quantity of phosphorous acid was added to a round bottom beaker containing a small amount of carbon dot solution. The round bottom flask was placed in an oil bath and stirred uniformly, and then a sol containing 10mL of aluminum hydroxide was slowly added dropwise to the mixed solution under heating for 3 hours.

The mass concentration of the phosphorous acid in the mixed solution is 30-70 wt%, preferably 50 wt%;

the volume of the carbon dot solution is 10 mu L-2 mL.

The content of aluminum hydroxide in the aluminum hydroxide sol is 70-90 wt%, and preferably 88%;

the reaction molar ratio of the phosphorous acid to the aluminum hydroxide is 2.8-3.2: 2, preferably 3: 2;

the heating condition is that the heating temperature is 60-90 ℃, and preferably 80 ℃;

the reaction heating time is 2-4h, preferably 3 h.

And naturally cooling to room temperature after the reaction is finished, carrying out suction filtration and distilled water washing on the mixed solution to obtain a product, and then placing the product in an oven for 6 hours to obtain the carbon quantum dot/aluminum phosphite composite material.

The heating temperature of the oven is 60-90 ℃, and preferably 70 ℃;

a carbon quantum dot/aluminum phosphite composite material prepared by the preparation method.

Compared with the prior art, the invention has the following advantages and effects:

(1) according to the invention, the hydrothermal method is adopted to prepare the carbon quantum dots, the hydrothermal method is the most common method for synthesizing the carbon quantum dots, and the prepared nano-particles are uniform in size, uniform in distribution and good in water solubility.

(2) The carbon quantum dot/aluminum phosphite composite material prepared by the invention has good water solubility, uniform particle size, uniform distribution and wide application.

(3) The prepared composite material is novel. There is no composite material of aluminum phosphite crystals and carbon dots.

(4) The carbon quantum dot/aluminum phosphite composite material shows better dispersibility, can be well dispersed in a matrix as a coating additive, has the effects of aging resistance and yellowing resistance, and is applied to the industrial fields such as coating, glass ceramics and the like.

(5) The preparation method is simple and convenient to operate, simple in required experimental equipment, low in production cost, short in period and strong in applicability.

Drawings

FIG. 1 is a photograph of an aluminum phosphite and carbon quantum dot/aluminum phosphite composite.

FIG. 2 is an XRD diffraction pattern of an aluminum phosphite and carbon quantum dot/aluminum phosphite composite.

FIG. 3 is a scanning electron micrograph of an aluminum phosphite and carbon quantum dot/aluminum phosphite composite.

FIG. 4 is an enlarged scanning electron microscope image of the composite material of aluminum phosphite and carbon quantum dots/aluminum phosphite.

Fig. 5 is a particle size distribution diagram of aluminum phosphite and carbon quantum dot/aluminum phosphite composite. The inset is a photograph of the carbon quantum dot/aluminum phosphite composite material under the excitation of ultraviolet light.

FIG. 6 is an infrared spectrum of a carbon quantum dot/aluminum phosphite composite.

FIG. 7 is a) excitation and emission spectra of carbon quantum dots; b) carbon quantum dot ultraviolet absorption spectrogram.

Fig. 8 is an ultraviolet absorption spectrum of aluminum phosphite and a carbon quantum dot/aluminum phosphite composite.

FIG. 9 is a drawing of a coating layer and a Control (Control: pure commercial coating layer) in which an aluminum phosphite and carbon quantum dot/aluminum phosphite composite material is added to a coating.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.

Comparative example 1 preparation of aluminum phosphite crystals

A. 14g phosphorous acid was added to a 25mL round bottom beaker containing 14g of the secondary aqueous solution. The round-bottomed flask was placed in an oil bath at 80 ℃ and stirred uniformly, and then 10mL of an aluminum hydroxide sol containing 8.879g of aluminum hydroxide was slowly added dropwise to the mixed solution, and the reaction was continued at 80 ℃ for 3 hours.

B. And naturally cooling to room temperature after the reaction is finished, filtering the mixed solution to remove the reaction solvent, washing for a plurality of times by using secondary distilled water, and then placing the solid in an oven at 70 ℃ for drying to obtain pure aluminum phosphite crystals.

In FIG. 1A₀As a picture of the aluminum phosphite obtained after the reaction of example 1, it can be seen that the prepared pure aluminum phosphite is white powder under a fluorescent lamp and does not have fluorescence under the irradiation of ultraviolet light. The aluminum phosphite solid in the obtained reaction system is precipitated to the bottom of the cup. In FIG. 2A₀The aluminum phosphite XRD diffractogram is shown to show that the aluminum phosphite is pure phase compared to the standard card. In FIG. 3A₀The aluminum phosphite is shown as a scanning electron micrograph of pure aluminum phosphite, and the aluminum phosphite is shown to be ellipsoid-shaped and easy to agglomerate.

Example 1 preparation of carbon quantum dot/aluminum phosphite composite

C. 14g phosphorous acid was added to a round bottom beaker containing a carbon dot solution. The round bottom flask was placed in an oil bath at 80 ℃ and stirred uniformly, and then 10mL of an aqueous solution containing 8.879g of aluminum hydroxide was slowly added dropwise to the mixed solution, and the reaction was continued at 80 ℃ for 3 hours.

D. And naturally cooling to room temperature after the reaction is finished, filtering the mixed solution to remove the reaction solvent, washing the mixed solution for a plurality of times by using secondary distilled water, and then placing the solid in an oven at 70 ℃ for drying to obtain the carbon quantum dot/aluminum phosphite composite material with the yield of 86.8 percent.

In FIG. 1A₁-A₇Is the carbon quantum dot/aluminum phosphite picture obtained after the reaction is finished (A)₁-A₇The addition amount of carbon dots is increased, and the other conditions are consistent), the prepared compound is white powder under a fluorescent lamp, and blue fluorescence is obtained under ultraviolet irradiation. The right image can be observed to see that the aluminum phosphite solid in the obtained reaction system is precipitated to the bottom of the cup, and the supernatant liquid shows blue fluorescence. In FIG. 2A₁-A₇Shown as a carbon quantum dot/aluminum phosphite XRD diffractogram, which shows that the carbon quantum dot/aluminum phosphite XRD diffraction peak positions are consistent with the pure phase.

In FIG. 3A₁-A₇Shown as a scanning electron micrograph of carbon quantum dots/aluminum phosphite, which shows that the dispersibility of the composite is changed from good to bad with the increase of the concentration of the carbon quantum dots, wherein the dispersibility is optimally A₂Wherein the shape of the single particle is ellipsoidal.

In step C, the carbon dot addition volume may range from 20. mu.L to 2 mL. FIG. 4 shows a scan enlarged view of A0-A7, from which it can be observed that as the addition of carbon dots is gradually increased, the composite surface forms flocs and tends to agglomerate.

FIG. 5 is A₀And A₁The particle size distribution diagram of the material can be seen visually that the particle size distribution interval of pure aluminum phosphite crystals is far and far largeIn the carbon quantum dot/aluminum phosphite composite material. In addition, the particle size of the composite material tends to become smaller. The inset is a picture of the composite material under ultraviolet irradiation, the composite material displays uniformly bright blue fluorescence, the fluorescence is uniformly distributed, and the carbon quantum dots can well regulate and control the dispersibility of the carbon quantum dots and can be embedded into the carbon quantum dots to keep the fluorescence characteristics of the carbon quantum dots. Then, we characterized the red spectrum of the A1 material, and from FIG. 6, we can observe that the surface of the composite material is rich in-OH, NH₂And C ═ O, C-O, C-N and other functional groups, and the functional groups enable the material to have the characteristics of good water dispersibility and easy addition.

In addition, the carbon quantum dots themselves have excellent luminescence characteristics, and the luminescence quantum efficiency reaches 80%. As shown in FIG. 7a, the fluorescence emission of the carbon quantum dots is in the blue region of 440nm, and the optimal excitation wavelength is 380nm in the ultraviolet region. More importantly, the carbon quantum dots have excellent ultraviolet absorption properties, as shown in fig. 7b, and the carbon quantum dots have excellent ultraviolet absorption in the ultraviolet radiation region (280nm-410 nm). The quantum dots are doped into the pores of the aluminum phosphite, and the fluorescence and ultraviolet absorption characteristics of the quantum dots are reserved. As shown in FIG. 8, composite A₁-A₇Shows solid ultraviolet absorption performance and has good yellowing resistance and aging resistance.

The carbon quantum dot/aluminum phosphite composite material is applied to a coating additive:

E. 5g of the carbon quantum dot/aluminum phosphite composite material is fully mixed with 20g of the commercial coating, and the mixture is mechanically stirred for 30 minutes.

F. And (3) smearing the uniform paint added with the carbon quantum dot/aluminum phosphite composite material on a wood plate with the diameter of 10 x 10cm, a steel plate and a glass plate with the diameter of 7.5cm, and performing vacuum drying for 4 hours at room temperature.

FIG. 9 is a photograph showing the carbon quantum dot/aluminum phosphite composite material obtained in example 3 as a paint additive added to a paint and applied to a wood board, an iron board and glass, from which a commercial paint alone and A₁The additive coating exhibits a relatively uniform, smooth texture, and A₀The surface of the additive coating is rough and uneven. In conclusion, the carbon quantum dot/aluminum phosphite composite material can be used for adding various materialsAdding the product and playing a role in resisting yellowing.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims (9)

Translated fromChinese

1.一种碳量子点调控亚磷酸铝晶体的制备方法,其特征在于，所述的制备方法包括如下的步骤：1. a preparation method of carbon quantum dots regulating aluminium phosphite crystal, is characterized in that, described preparation method comprises the steps:1)将亚磷酸加入到含有碳点溶液中，油浴加热搅拌均匀，然后往混合溶液中缓慢滴加入氢氧化铝溶胶，持续反应；1) adding phosphorous acid to the solution containing carbon dots, heating and stirring in an oil bath, then slowly adding aluminum hydroxide sol dropwise to the mixed solution to continue the reaction;所述的亚磷酸在混合溶液中的质量浓度为30％～70wt％；The mass concentration of the phosphorous acid in the mixed solution is 30% to 70% by weight;所述的碳点溶液体积为10μL-2mL；The volume of the carbon dot solution is 10 μL-2 mL;所述亚磷酸与氢氧化铝的反应摩尔比为2.8-3.2：2；The reaction molar ratio of the phosphorous acid and aluminum hydroxide is 2.8-3.2:2;加热温度为60～90℃；The heating temperature is 60～90℃;2)反应结束后自然冷却至室温，将混合溶液抽滤，蒸馏水洗涤，然后产物烘干即可得到碳量子点/亚磷酸铝复合材料。2) After the reaction is finished, it is naturally cooled to room temperature, the mixed solution is suction filtered, washed with distilled water, and then the product is dried to obtain a carbon quantum dot/aluminum phosphite composite material.所述烘干温度为60-90℃。The drying temperature is 60-90°C.2.如权利要求1所述的碳量子点调控亚磷酸铝晶体的制备方法,其特征在于，所述的亚磷酸在混合溶液中的质量浓度为50wt％。2 . The preparation method of carbon quantum dots regulating aluminum phosphite crystals as claimed in claim 1 , wherein the mass concentration of the phosphorous acid in the mixed solution is 50 wt %. 3 .3.如权利要求1所述的碳量子点调控亚磷酸铝晶体的制备方法,其特征在于，所述的氢氧化铝溶胶中氢氧化铝含量为70～90wt％。3 . The preparation method of carbon quantum dots regulating aluminum phosphite crystals as claimed in claim 1 , wherein the aluminum hydroxide content in the aluminum hydroxide sol is 70-90 wt %. 4 .4.如权利要求1所述的碳量子点调控亚磷酸铝晶体的制备方法,其特征在于，所述的亚磷酸与氢氧化铝的反应摩尔比为3：2。4. The preparation method of carbon quantum dots regulating aluminum phosphite crystals as claimed in claim 1, wherein the reaction molar ratio of the phosphorous acid and aluminum hydroxide is 3:2.5.如权利要求1所述的碳量子点调控亚磷酸铝晶体的制备方法,其特征在于，所述的烘干温度为70℃。5. The preparation method of carbon quantum dots regulating aluminum phosphite crystals as claimed in claim 1, wherein the drying temperature is 70°C.6.如权利要求1所述的碳量子点调控亚磷酸铝晶体的制备方法,其特征在于，所述的碳量子点的合成方法如下：6. the preparation method of carbon quantum dot regulation and control aluminum phosphite crystal as claimed in claim 1, is characterized in that, the synthetic method of described carbon quantum dot is as follows:将柠檬酸和乙二胺溶于二次蒸馏水中，然后将溶液转移到反应釜中，在加热条件下反应至结束，反应后，用水或自然冷却反应堆至室温。Dissolve citric acid and ethylenediamine in double distilled water, then transfer the solution to a reactor, and react under heating conditions to the end. After the reaction, cool the reactor with water or naturally to room temperature.所述柠檬酸用量为6-10wt％；The amount of citric acid is 6-10wt%;所述乙二胺用量为2-4wt％；The ethylenediamine consumption is 2-4wt%;加热温度为180-220℃。The heating temperature is 180-220°C.7.如权利要求6所述的碳量子点调控亚磷酸铝晶体的制备方法,其特征在于，所述的柠檬酸用量为8.8％。7. The preparation method of carbon quantum dots regulating aluminum phosphite crystals as claimed in claim 6, wherein the citric acid dosage is 8.8%.8.如权利要求6所述的碳量子点调控亚磷酸铝晶体的制备方法,其特征在于，所述的乙二胺用量为3wt％。8. The preparation method of carbon quantum dots regulating aluminum phosphite crystals as claimed in claim 6, wherein the amount of the ethylenediamine is 3wt%.9.如权利要求6所述的碳量子点调控亚磷酸铝晶体的制备方法,其特征在于，所述的加热温度为200摄氏度。9. The preparation method of carbon quantum dots regulating aluminum phosphite crystals as claimed in claim 6, wherein the heating temperature is 200 degrees Celsius.

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