A porous core-shell purification modifier, self-purifying modified asphalt and preparation method

Abstract

The present invention discloses a porous core-shell purification modifier, a self-purifying modified asphalt and a preparation method thereof, belonging to the technical field of road materials. The porous core-shell purification modifier has a spherical egg yolk-shell porous structure, including a shell and a core located in the shell. The shell is a graphdiyne / tourmaline negative ion powder composite, and the core is composed of a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite. There is a cavity between the core and the shell. The surface-porous outer shell and the micron-scale cavity reactor can effectively adsorb asphalt fumes and vehicle exhaust. At the same time, the permanent polarization effect of the tourmaline negative ion powder and the photocatalytic degradation ability of the inner core catalyst can effectively solve the problems of blockage and saturation of traditional adsorption materials, and realize the adsorption and degradation purification of pollutants in the whole life cycle of the road.

Description

Technical Field

[0001] The present invention belongs to the technical field of road materials, and particularly relates to a porous core-shell structure purification modifier, a modified asphalt with a full-life cycle self-purification function, and a preparation method thereof. Background Art

[0002] At present, the road construction in China mainly focuses on asphalt pavements. However, there are still a series of technical problems in the ecological environment protection during the construction and operation of asphalt pavements at the present stage, such as: a large amount of flue gas is generated during the construction stage of hot mix asphalt mixture, polluting the environment; the emissions of volatile harmful substances from asphalt pavements and vehicle exhaust in the road area pollute the atmosphere during the operation stage. In order to reduce the pollutant emissions of hot mix asphalt mixture, research on some hot mix emission reduction modified asphalt and mixture technologies has been carried out at home and abroad successively. The emission reduction principle is to add inhibitors, warm mix agents or flame retardants to asphalt to modify the asphalt and reduce the release of harmful substances in asphalt fume. However, the emission reduction and purification effect mainly focuses on the construction stage of asphalt mixture mixing and paving, and the emission reduction and purification of the whole life cycle of asphalt pavement construction, operation and maintenance have not been achieved. Moreover, the vehicle exhaust in the road area should also achieve emission reduction and purification. Summary of the Invention

[0003] The present invention provides a porous core-shell purification modifier, a self-purification modified asphalt and a preparation method thereof, which solve the technical problem that the existing modified asphalt does not achieve the full-life cycle emission reduction and purification function.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A porous core-shell purification modifier, the porous core-shell purification modifier has a spherical egg yolk - eggshell porous structure, including a shell and a core located in the shell. The shell is a graphite alkyne / tourmaline negative ion powder composite, and the core is composed of a nano-onion carbon / heterojunction compound / subphthalocyanine composite. There is a cavity between the core and the shell, and the heterojunction compound is Yb2BiSbO7 / CdBiYO4.

[0006] Furthermore, the shell has pores, and the diameter of the pores is 5 - 100 nm.

[0007] A preparation method of a porous core-shell purification modifier includes the following steps:

[0008] Step 1, preparing a nano-onion carbon / heterojunction compound / subphthalocyanine composite core with nano-onion carbon, a heterojunction compound and subphthalocyanine, and the heterojunction compound is Yb2BiSbO7 / CdBiYO4;

[0009] Step 2, preparing a SiO2 outer shell core-shell microsphere solution with the nano-onion carbon / heterojunction compound / subphthalocyanine composite core and tetraethyl orthosilicate solution:

[0010] Step 3: Prepare a porous core-shell microsphere solution of nano-onion carbon / heterojunction compound / subphthalocyanine composite @SiO2@graphyne / tourmaline anion powder composite using graphyne, tourmaline anion powder, calcium carbonate powder, dispersant I, dispersant II, and SiO2 shell-core microsphere solution;

[0011] Step 4: Prepare a porous core-shell structure purifying agent of nano-onion carbon / heterojunction compound / subphthalocyanine composite @graphyne / tourmaline anion powder composite using the porous core-shell microsphere solution of nano-onion carbon / heterojunction compound / subphthalocyanine composite @SiO2@graphyne / tourmaline anion powder composite;

[0012] In the above Steps 1 to 4, by weight, 100 parts of tourmaline anion powder, 45 - 55 parts of graphyne, 20 - 25 parts of tetraethyl orthosilicate, 3 - 5 parts of calcium carbonate powder, 20 - 30 parts of heterojunction compound, 5 - 10 parts of subphthalocyanine, 20 - 25 parts of nano-onion carbon, 45 - 50 parts of dispersant I, and 35 - 40 parts of dispersant II.

[0013] Further, Step 1 includes the following steps:

[0014] Step 1.1: Add n-hexane to the deionized aqueous solution of the heterojunction compound, react at room temperature, filter out the powder after the reaction is completed, dry and sieve it to obtain the pretreated heterojunction compound;

[0015] Step 1.2: Place the pretreated heterojunction compound in ethanol, ultrasonically disperse it to form a mixed solution of nano-onion carbon and heterojunction compound;

[0016] Step 1.3: Ball-mill the mixed solution of nano-onion carbon and heterojunction compound to obtain a nano-onion carbon / heterojunction compound composite solution;

[0017] Step 1.4: Place subphthalocyanine in ethanol to obtain a subphthalocyanine solution, heat the nano-onion carbon / heterojunction compound composite solution, and gradually add the ultrasonically treated subphthalocyanine solution dropwise, and heat until the solution evaporates completely to obtain a nano-onion carbon / heterojunction compound / subphthalocyanine composite;

[0018] Step 1.5: Dry the nano-onion carbon / heterojunction compound / subphthalocyanine composite to constant weight, take out the dried solid product, grind, sieve, disperse, and calcine it to obtain a nano-onion carbon / heterojunction compound / subphthalocyanine composite core.

[0019] Further, Step 2 includes the following steps:

[0020] Step 2.1: Place tetraethyl orthosilicate in ethanol to obtain a tetraethyl orthosilicate solution;

[0021] Step 2.2: Place the nano-onion-like carbon / heterojunction compound / subphthalocyanine composite core in ethanol, disperse it by ultrasonic treatment, then add 10 wt.% - 15 wt.% ammonia water solution and stir evenly. Dropwise add tetraethyl orthosilicate solution, stir evenly at room temperature and age for 18 - 24 h at room temperature to obtain the nano-onion-like carbon / heterojunction compound / subphthalocyanine composite@SiO₂ core-shell microsphere solution;

[0022] Step 2.3: Sinter the nano-onion-like carbon / heterojunction compound / subphthalocyanine composite@SiO₂ core-shell microsphere solution at 170 °C - 175 °C for 1.5 - 2 h to obtain the core-shell microspheres. Wash the core-shell microspheres obtained by high-temperature sintering, and finally place the core-shell microspheres in an ethanol solution to obtain the SiO₂ shell core-shell microsphere solution.

[0023] Further, Step 3 includes the following steps:

[0024] Step 3.1: Add dispersant I to the deionized water solution of tourmaline negative ion powder, react at room temperature. After the reaction is completed, filter out the powder of tourmaline negative ion powder, dry the powder of tourmaline negative ion powder to obtain the pretreated tourmaline negative ion powder;

[0025] Step 3.2: Add graphdiyne to ethanol and disperse it by ultrasonic treatment to obtain a graphdiyne solution. Add the tourmaline negative ion powder to the graphdiyne solution and stir evenly to obtain a graphdiyne / tourmaline negative ion powder solution;

[0026] Step 3.3: Ball-mill the graphdiyne / tourmaline negative ion powder solution to obtain a graphdiyne / tourmaline negative ion powder composite solution;

[0027] Step 3.4: Dry the graphdiyne / tourmaline negative ion powder composite solution to obtain a solid product A. Grind, screen and disperse the solid product A to prepare a graphdiyne / tourmaline negative ion powder composite powder;

[0028] Step 3.5: Add the graphdiyne / tourmaline negative ion powder composite powder and calcium carbonate powder to the SiO₂ shell core-shell microsphere solution, stir evenly, dropwise add dispersant II ethylene glycol and disperse by ultrasonic treatment to obtain a SiO₂ shell core-shell microsphere / graphdiyne and tourmaline negative ion powder composite / calcium carbonate mixed solution;

[0029] Step 3.6: Ball-mill and then dry the SiO₂ shell core-shell microsphere / graphdiyne and tourmaline negative ion powder composite / calcium carbonate mixed solution to obtain a solid product B. Grind, screen and disperse the solid product B to obtain a nano-onion-like carbon / heterojunction compound / subphthalocyanine composite@SiO₂@graphdiyne / tourmaline negative ion powder composite / calcium carbonate core-shell microsphere;

[0030] Step 3.7: Place the nano-onion carbon / heterojunction compound / subphthalocyanine complex@SiO2@graphene alkyne / tourmaline negative ion powder complex / calcium carbonate core-shell microspheres in deionized water and stir evenly. Then add 10 wt.% - 15 wt.% HCl solution and react at room temperature. After that, wash and place them in ionized water to obtain a solution of nano-onion carbon / heterojunction compound / subphthalocyanine complex@SiO2@graphene alkyne / tourmaline negative ion powder complex porous core-shell microspheres.

[0031] Furthermore, by weight, 100 parts of tourmaline negative ion powder, 50 parts of graphene alkyne, 24 parts of tetraethyl orthosilicate, 5 parts of calcium carbonate powder, 27 parts of heterojunction compound, 8 parts of subphthalocyanine, 23 parts of nano-onion carbon, 48 parts of dispersant I, and 36 parts of dispersant II.

[0032] A self-purifying modified asphalt is made from the following raw materials by mass: 80 - 88 parts of road asphalt, 9 - 15 parts of purification modifier, 3 - 5 parts of coupling agent, and the sum of the mass parts of road asphalt, purification modifier, and coupling agent is 100 parts. The purification modifier is the above-mentioned purification modifier.

[0033] Furthermore, by mass, 84 parts of road asphalt, 12 parts of purification modifier, and 4 parts of coupling agent.

[0034] A preparation method of the self-purifying modified asphalt includes the following steps:

[0035] Heat the road asphalt to 160 ± 5 °C, add the porous core-shell purification modifier and silane coupling agent to the road asphalt, and stir evenly to obtain the self-purifying functional modified asphalt. The road asphalt is 80 - 88 parts, the purification modifier is 9 - 15 parts, the coupling agent is 3 - 5 parts, and the sum of the mass parts of road asphalt, purification modifier, and coupling agent is 100 parts. The purification modifier is the above-mentioned purification modifier.

[0036] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0037] (1) The porous core-shell structure purification modifier prepared by the present invention is a purification agent similar to the yolk-shell structure, with a surface porous shell with electrostatic adsorption force and a micron-sized cavity reactor, which can effectively adsorb asphalt fumes and vehicle exhaust. At the same time, the permanent polarization effect of tourmaline negative ion powder and the photocatalytic degradation ability of the inner core catalyst - nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex can effectively solve the problems of blockage and saturation of traditional adsorption materials, and realize the adsorption and degradation purification of pollutants in the whole life cycle of the road.

[0038] (2) The composite shell of graphdiyne and tourmaline negative ion powder has a powerful ability to adsorb asphalt fumes and tail gases due to the synergistic effect. Graphdiyne has a large specific surface area, which can provide more adsorption sites, improving the adsorption performance. At the same time, it also has excellent electron transport ability, which can effectively promote the separation of electrons and holes in the tourmaline negative ion powder, increasing the surface electrostatic field and helping pollutants to be adsorbed into the inner cavity. The negative ion release amount of the tourmaline negative ion powder is 5000 ions, far higher than that of traditional tourmaline, and it has a stronger ability to reduce and degrade pollutants in asphalt fumes and vehicle exhaust.

[0039] The core catalyst and the graphdiyne / tourmaline negative ion powder shell have advantages that a single catalyst does not have due to the synergistic effect. The catalyst core is a movable nucleus. When it contacts the shell, the surface electrostatic field of the tourmaline negative ion powder can enable photoelectrons to be directionally transported to the positive pole of the tourmaline negative ion powder through graphdiyne with excellent electron transport ability, thus promoting the rapid separation of electrons and holes, inhibiting the recombination of photogenerated electrons and holes, and effectively improving the performance of the catalyst in degrading pollutants.

[0040] The core catalyst has the ability to efficiently catalyze and degrade pollutants. Nano-onion carbon has good electron conduction characteristics and a large specific surface area, which is conducive to the transfer of photogenerated electrons and enhancing the adsorption performance of the catalyst. Composite with heterojunctions can effectively avoid the recombination of photogenerated electron-hole pairs, prolong the lifetime of carriers, and thus improve the photocatalytic performance of the material. Subphthalocyanine as a photosensitizer can increase the wavelength response range of the photocatalyst, significantly enhance the response in the visible light region of the system, and effectively separate photogenerated carriers, improving the photocatalytic degradation performance of the catalyst.

[0041] (3) The cavity of the yolk-shell structure can serve as an efficient microreactor. The internal space can be used for the storage of pollutants, effectively exposing the active sites of the core, increasing the contact time between reactants and active sites, thereby improving the catalytic activity and mass transfer efficiency, and achieving a large amount of adsorption and efficient degradation and purification of pollutants.

[0042] (4) The eggshell not only helps to disperse the catalyst particles, preventing their aggregation from reducing the active surface area of the catalyst, but also protects the internal catalyst particles from the influence of harsh environmental conditions (chemical and thermal), thus maintaining the long-lasting life of the catalyst in efficiently degrading and purifying pollutants.

[0043] (5) The cavity of the yolk-shell structure helps to achieve multiple reflections of light in the inner cavity, effectively prolonging the action time of light, which is beneficial to improving the photocatalytic efficiency. Description of the Drawings

[0044] Figure 1a It is the penetration and softening point diagrams in Examples 1 to 9;

[0045] Figure 1bIt is the ductility diagram in Examples 1 to 9;

[0046] Figure 2a It is the comparison diagram of penetration before and after aging between Example 1 and Comparative Examples 6 to 8;

[0047] Figure 2b It is the comparison diagram of softening point before and after aging between Example 1 and Comparative Examples 6 to 8;

[0048] Figure 2c It is the comparison diagram of ductility before and after aging between Example 1 and Comparative Examples 6 to 8;

[0049] Figure 3 It is the emission reduction rate diagram of the emission reduction and purification modified asphalt in Examples 1 to 9;

[0050] Figure 4 It is the comparison diagram of the emission reduction effect of the modified asphalt between Example 1 and Comparative Examples 1 to 5;

[0051] Figure 5 It is the tail gas purification rate diagram in Examples 1 to 9;

[0052] Figure 6 It is the comparison diagram of the tail gas purification rate between Example 1 and Comparative Examples 1 to 5;

[0053] Figure 7 It is the flow chart of the preparation method of the porous core-shell structure purification modifier provided by the present invention. Detailed implementation manners

[0054] In order to make the objectives and technical solutions of the present invention clearer and easier to understand. The following further details the present invention in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0055] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more. In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0056] First part:

[0057] A porous core-shell structure purification modifier is made from the following raw materials: tourmaline negative ion powder, graphdiyne, nano calcium carbonate powder, Yb2BiSbO7 / CdBiYO4 heterojunction compound, nano onion carbon, tetraethyl orthosilicate, subphthalocyanine, dispersant I and dispersant II.

[0058] Specifically, it is made from the following raw materials by weight: 100 parts of tourmaline negative ion powder, 45 - 55 parts of graphdiyne, 20 - 25 parts of tetraethyl orthosilicate, 3 - 5 parts of calcium carbonate powder, 20 - 30 parts of Yb2BiSbO7 / CdBiYO4 heterojunction compound, 5 - 10 parts of subphthalocyanine, 20 - 25 parts of nano onion carbon, 45 - 50 parts of dispersant I and 35 - 40 parts of dispersant II.

[0059] Preferably, it is made from the following raw materials by weight: 100 parts of tourmaline negative ion powder, 50 parts of graphdiyne, 24 parts of tetraethyl orthosilicate, 5 parts of calcium carbonate powder, 27 parts of Yb2BiSbO7 / CdBiYO4 heterojunction compound, 8 parts of subphthalocyanine, 23 parts of nano onion carbon, 48 parts of dispersant I and 36 parts of dispersant II.

[0060] The present invention also has the following technical features:

[0061] The particle size of the tourmaline anion powder described is 6000 - 8000 mesh, and the anion release amount is 2000 - 8000 ions.

[0062] The thickness of the graphdiyne described is 0.7 - 1.5 μm, and the pore diameter is 3.8 - 4.2 Å.

[0063] The calcium carbonate described is nano calcium carbonate, with a diameter of 5 - 50 nm.

[0064] The diameter of the Yb2BiSbO7 / CdBiYO4 heterojunction compound described is 1.4 - 2 μm.

[0065] The diameter of the nano onion - like carbon described is 10 - 50 nm.

[0066] The dispersant Ⅰ is isomeric tridecyl alcohol polyoxyethylene ether, and the dispersant Ⅱ is ethylene glycol.

[0067] Specifically, the specific structure of the porous core - shell structure purification modifier is a spherical yolk - shell porous structure, including a shell and a core located in the shell. The pore diameter of the pores on the shell is between 5 - 100 nm, and the particle size of the porous core - shell structure purification modifier is between 6 - 9 μm. The shell is composed of a graphdiyne / tourmaline anion powder composite, the core is composed of a nano onion - like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite, and there is a gap between the core and the shell.

[0068] Refer to Figure 7 , the present invention also protects a preparation method of the porous core - shell structure purification modifier as described above. This method includes the following steps:

[0069] Step 1, pretreatment of the raw materials of the porous core - shell structure purification modifier:

[0070] Add isomeric tridecyl alcohol polyoxyethylene ether to the deionized aqueous solution of tourmaline anion powder, react at room temperature for 10 - 12 h, stir once every 1 h. After the reaction is completed, filter out the powder of tourmaline anion powder, place it in an oven at 60 °C to dry, sieve it, and obtain the pretreated tourmaline anion powder for storage and later use;

[0071] Add n - hexane to the deionized aqueous solution of Yb2BiSbO7 / CdBiYO4 heterojunction compound, react at room temperature for 10 - 12 h, stir once every 1 h. After the reaction is completed, filter out the powder, place it in an oven at 60 °C to dry, sieve it, and obtain the pretreated Yb2BiSbO7 / CdBiYO4 heterojunction compound for storage and later use;

[0072] Place tetraethyl orthosilicate in ethanol to obtain a 0.1 - 0.15 mol / L tetraethyl orthosilicate solution;

[0073] Step 2, Preparation of nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite core:

[0074] Step 201, Place nano-onion-like carbon and the pretreated Yb2BiSbO7 / CdBiYO4 heterojunction compound in Step 1 into ethanol, and ultrasonically disperse for 20 - 25 min to form a mixed solution of nano-onion-like carbon and Yb2BiSbO7 / CdBiYO4 heterojunction compound;

[0075] Step 202, Place the mixed solution of nano-onion-like carbon and Yb2BiSbO7 / CdBiYO4 heterojunction compound into a planetary high-energy ball mill, with a ball milling speed of 200 rpm and a ball milling time of 2 h to complete the ball milling process, and obtain a nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound composite solution;

[0076] Step 203, Place subphthalocyanine into ethanol to obtain a subphthalocyanine solution, ultrasonically treat the subphthalocyanine solution for 20 - 25 min, heat the nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound composite solution to 80 °C, and gradually add the ultrasonically treated subphthalocyanine solution dropwise to the nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound composite, so that subphthalocyanine self-assembles onto the nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound composite through π - stacking, and evaporate the ethanol and water in the nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound composite solution until they are completely volatilized to obtain a nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite;

[0077] Step 204, Place the nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite in an oven at 180 °C and dry it to constant weight, take out the dried solid product, grind, sieve, and disperse it, and finally transfer the dried composite to a muffle furnace at 250 - 255 °C and calcine for 2 - 3 h to obtain a nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite core powder;

[0078] Step 3, Preparation of nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2 core-shell microsphere solution:

[0079] Step 301: Place the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex core in ethanol, ultrasonically disperse it for 20 min, then add 10 wt.% - 15 wt.% ammonia water solution and stir evenly. Dropwise add the tetraethyl orthosilicate solution obtained in Step 1, stir at room temperature for 1 h, and age at room temperature for 18 - 24 h to obtain a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2 core-shell microsphere solution;

[0080] Step 302: Place the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2 core-shell microsphere solution obtained in Step 301 in a stainless steel autoclave with a polytetrafluoroethylene liner, and sinter it at a high temperature of 170 ºC - 175 ºC for 1.5 - 2 h to obtain core-shell microspheres. Wash the core-shell microspheres obtained by high-temperature sintering 4 times with deionized water solution and 1 time with ethanol. Finally, place the core-shell microspheres in an ethanol solution to obtain a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2 core-shell microsphere solution;

[0081] Step 4: Preparation of nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2@graphdiyne / tourmaline negative ion powder composite porous core-shell microsphere solution:

[0082] Step 401: Add graphdiyne to ethanol, ultrasonically disperse it for 20 - 30 min to obtain a graphdiyne solution. Add the pretreated tourmaline negative ion powder in Step 1 to the graphdiyne solution and stir evenly to obtain a graphdiyne / tourmaline negative ion powder solution;

[0083] Step 402: Place the graphdiyne / tourmaline negative ion powder solution in a planetary high-energy ball mill, with a ball milling speed of 200 rpm and a ball milling time of 2 h to complete the ball milling process and obtain a graphdiyne / tourmaline negative ion powder composite solution;

[0084] Step 403: Take out the ball-milled graphdiyne / tourmaline negative ion powder composite solution, place it in an oven at 180 ºC and dry it to constant weight. Take out the dried solid product, grind it, sieve it and disperse it to obtain a graphdiyne / tourmaline negative ion powder composite powder;

[0085] Step 404: Add the graphite alkyne / tourmaline anion powder composite powder and calcium carbonate powder to the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2 core-shell microsphere solution obtained in Step 3, stir evenly, add ethylene glycol and ultrasonically disperse for 20 - 30 min to obtain a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2 core-shell microsphere solution / graphite alkyne and tourmaline anion powder composite / calcium carbonate mixed solution;

[0086] Step 405: Place the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2 core-shell microsphere solution / graphite alkyne and tourmaline anion powder composite / calcium carbonate mixed solution in a planetary high-energy ball mill, with a ball milling speed of 200 rpm and a ball milling time of 5 h. Take out the ball-milled mixed solution and place it in an oven at 180 °C to dry to a constant weight. Take out the dried solid product, grind, sieve, and disperse it to obtain nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2@graphite alkyne / tourmaline anion powder composite / calcium carbonate core-shell microspheres;

[0087] Step 406: Place the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2@graphite alkyne / tourmaline anion powder composite / calcium carbonate core-shell microspheres obtained in Step 405 in deionized water and stir evenly. Then add 10 wt.% - 15 wt.% HCl solution and react with calcium carbonate at room temperature for 12 h, stirring once every 1 h. After the reaction is completed, wash twice with deionized water and place it in deionized water to obtain a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2@graphite alkyne / tourmaline anion powder composite porous core-shell microsphere solution;

[0088] Step 5: Preparation of a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@graphite alkyne / tourmaline anion powder composite porous core-shell structure purifying agent:

[0089] Add 5 wt.% - 10 wt.% NaOH solution to the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine complex@SiO2@graphene alkyne / tourmaline negative ion powder complex porous core-shell microsphere solution. The NaOH solution reacts with SiO2 for 12 h, and it is stirred once every 1 h. After the reaction is completed, a cavity is formed between the shell and the core. Wash it 3 times with deionized water and 1 time with ethanol respectively to obtain microsphere powder. Place the microsphere powder in an oven at 60 °C and dry it to constant weight. After sieving and dispersion, a porous core-shell structure purification modifier is obtained.

[0090] The present invention also protects a modified asphalt with a full-life-cycle self-purification function, which is made from the following raw materials: road asphalt, porous core-shell purification modifier, and coupling agent.

[0091] The porous core-shell purification modifier described above is the porous core-shell purification modifier as described above.

[0092] Specifically, in terms of mass parts, it is made from the following raw materials: 80 - 88 parts of road asphalt, 9 - 15 parts of purification modifier, and 3 - 5 parts of coupling agent. The sum of the mass fractions of the raw materials is 100 parts.

[0093] Preferably, in terms of mass parts, it is made from the following raw materials: 84 parts of road asphalt, 12 parts of purification modifier, and 4 parts of coupling agent.

[0094] The road asphalt is 70 # base asphalt, 90 # base asphalt, SBS modified asphalt, or rubber powder modified asphalt.

[0095] The coupling agent is a silane coupling agent or a phthalate coupling agent.

[0096] The present invention also protects a preparation method of the modified asphalt with a full-life-cycle self-purification function as described above. This method includes the following steps:

[0097] Heat the road asphalt to 160 ± 5 °C, slowly add the porous core-shell purification modifier and the silane coupling agent to the road asphalt. First, use a stirrer to stir at a low speed for 15 min, and the stirring rate is 900 - 1200 rpm. Then, use a shearer to shear at a high speed for 30 min, and the shear rate is 3000 - 3500 rpm to make the modifier distribute fully and evenly, and obtain the modified asphalt with a full-life-cycle self-purification function.

[0098] Example 1

[0099] This example gives a modified asphalt with a full-life-cycle self-purification function. In terms of weight parts, it is made from the following raw materials: 84 parts of road asphalt, 12 parts of porous core-shell structure purification modifier, and 4 parts of coupling agent.

[0100] The described porous core-shell structure purification modifier is made from the following raw materials: 100 parts of tourmaline negative ion powder, 50 parts of graphdiyne, 24 parts of tetraethyl orthosilicate, 5 parts of calcium carbonate powder, 27 parts of Yb2BiSbO7 / CdBiYO4 heterojunction compound, 8 parts of subphthalocyanine, 23 parts of nano-onion carbon, 48 parts of dispersant I, and 36 parts of dispersant II. The specific structure of the porous core-shell structure purification modifier is a spherical yolk-shell porous structure with pore diameters between 5 and 100 nm and particle diameters between 6 and 9 μm.

[0101] In this embodiment:

[0102] The particle size of the described tourmaline negative ion powder is 8000 mesh, and the negative ion release amount is 5000 ions.

[0103] The thickness of the described graphdiyne is 1 μm, and the pore diameter is 4.2 Å.

[0104] The diameter of the described nano-calcium carbonate is 10 nm.

[0105] The diameter of the described Yb2BiSbO7 / CdBiYO4 heterojunction compound is 2 μm.

[0106] The diameter of the described nano-onion carbon is 50 nm.

[0107] The described road asphalt is 70 # base asphalt.

[0108] The described dispersant I is isomeric tridecyl alcohol polyoxyethylene ether, and dispersant II is ethylene glycol.

[0109] The described coupling agent is a silane coupling agent.

[0110] The preparation method of the modified asphalt with a full-life-cycle self-purification function in this embodiment includes the following steps:

[0111] Step 1, pretreatment of the raw materials of the porous core-shell structure purification modifier:

[0112] Add isomeric tridecyl alcohol polyoxyethylene ether to the deionized aqueous solution of tourmaline negative ion powder, react at room temperature for 10 h, stir once every 1 h, filter out the powder of tourmaline negative ion powder after the reaction, place it in an oven at 60 °C to dry, sieve it, and store it for later use;

[0113] Add n-hexane to the deionized aqueous solution of Yb2BiSbO7 / CdBiYO4 heterojunction compound, react at room temperature for 12 h, stir once every 1 h, filter out the powder after the reaction, place it in an oven at 60 °C to dry, sieve it, and store it for later use;

[0114] Place tetraethyl orthosilicate in ethanol to obtain a 0.1 mol / L tetraethyl orthosilicate solution;

[0115] Step 2, Preparation of nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine nucleus:

[0116] Step 201, Place nano-onion-like carbon and the pretreated Yb2BiSbO7 / CdBiYO4 heterojunction compound in Step 1 into ethanol, and ultrasonically disperse for 20 - 25 min to form a mixed solution of nano-onion-like carbon and Yb2BiSbO7 / CdBiYO4 heterojunction compound;

[0117] Step 202, Place the mixed solution of nano-onion-like carbon and Yb2BiSbO7 / CdBiYO4 heterojunction compound in a planetary high-energy ball mill, with a ball milling speed of 200 rpm and a ball milling time of 2 h. Complete the ball milling process to obtain a nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound composite solution;

[0118] Step 203, Place phthalocyanine in ethanol to obtain a phthalocyanine solution. Ultrasonically treat the obtained phthalocyanine solution for 20 min. Heat the nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound composite solution to 80 °C, and gradually add the ultrasonically treated phthalocyanine solution. Continue heating until the solution evaporates completely to obtain a nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine composite;

[0119] Step 204, Place the nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine composite in an oven at 180 °C and dry it to constant weight. Take out the dried solid product, grind, sieve, and disperse it. Finally, transfer the dried composite to a muffle furnace at 250 °C and calcine it for 1.5 h to obtain a nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine composite nucleus;

[0120] Step 3, Preparation of nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine composite@SiO2 core-shell microsphere solution:

[0121] Step 301, Place the nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine composite nucleus in ethanol, ultrasonically disperse for 20 min, then add 10 wt.% ammonia water solution and stir evenly. Gradually add the pretreated tetraethyl orthosilicate solution in Step 1, stir at room temperature for 1 h, and age at room temperature for 24 h to obtain a nano-onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine composite@SiO2 core-shell microsphere solution;

[0122] Step 302: Place the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2 core-shell microsphere solution obtained in Step 301 into a stainless-steel autoclave with a polytetrafluoroethylene liner, and perform high-temperature sintering at 175 °C for 2 h to obtain core-shell microspheres. Wash the core-shell microspheres obtained by high-temperature sintering 4 times with deionized water solution and 1 time with ethanol. Finally, place the core-shell microspheres in an ethanol solution to obtain the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2 core-shell microsphere solution;

[0123] Step 4: Preparation of nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2@graphene alkyne / tourmaline anion powder composite porous core-shell microspheres:

[0124] Step 401: Add graphene alkyne into ethanol and ultrasonically disperse it for 30 min. Add the treated tourmaline anion powder in Step 1 into the graphene alkyne solution and stir evenly to obtain the graphene alkyne / tourmaline anion powder solution;

[0125] Step 402: Place the graphene alkyne / tourmaline anion powder solution in a planetary high-energy ball mill. The ball milling speed is 200 rpm and the ball milling time is 2 h to complete the ball milling process and obtain the graphene alkyne / tourmaline anion powder composite solution;

[0126] Step 403: Take out the ball-milled graphene alkyne / tourmaline anion powder composite solution and place it in an oven at 180 °C to dry to constant weight. Take out the dried solid product, grind it, sieve it and disperse it to obtain the graphene alkyne / tourmaline anion powder composite powder;

[0127] Step 404: Add the graphene alkyne / tourmaline anion powder composite powder and calcium carbonate powder to the SiO2 shell core-shell microsphere solution obtained in Step 3 and stir evenly. Dropwise add ethylene glycol and ultrasonically disperse it for 30 min to obtain the SiO2 shell core-shell microsphere / graphene alkyne and tourmaline anion powder composite / calcium carbonate mixed solution;

[0128] Step 405: Place the SiO2 shell core-shell microsphere / graphene alkyne and tourmaline anion powder composite / calcium carbonate mixed solution in a planetary high-energy ball mill. The ball milling speed is 200 rpm and the ball milling time is 5 h. Take out the ball-milled mixed solution and place it in an oven at 180 °C to dry to constant weight. Take out the dried solid product, grind it, sieve it and disperse it to obtain the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2@graphene alkyne / tourmaline anion powder composite / calcium carbonate core-shell microspheres;

[0129] Step 406: Place the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine complex@SiO2@graphene alkyne / tourmaline anion powder complex / calcium carbonate core-shell microspheres obtained in Step 405 in deionized water and stir evenly. Then add 10 wt.% HCl solution and react at room temperature for 12 h, stirring once every 1 h. After the reaction is completed, wash twice with deionized water and place in deionized water to obtain a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine complex@SiO2@graphene alkyne / tourmaline anion powder complex porous core-shell microsphere solution;

[0130] Step Five: Preparation of a porous core-shell structure purifying agent of nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine complex@graphene alkyne / tourmaline anion powder complex:

[0131] Add 5 wt.% NaOH solution to the porous outer shell microsphere solution of the graphene alkyne and tourmaline anion powder complex, react for 12 h, stirring once every 1 h. After the reaction is completed, wash three times with deionized water and once with ethanol respectively. Place the washed microsphere powder in an oven at 60 °C and dry to constant weight. After sieving and dispersion, a porous core-shell purifying modifier is obtained.

[0132] Step Six: Preparation of modified asphalt with a full-life-cycle self-purifying function:

[0133] Heat the road asphalt to 160 ± 5 °C, slowly add the purifying modifier and silane coupling agent to the road asphalt. First, stir at a low speed with a stirrer for 15 min, with a shear rate of 900 rpm, and then shear at a high speed with a shearer for 30 min, with a shear rate of 3000 rpm to obtain modified asphalt with a full-life-cycle self-purifying function.

[0134] Example 2

[0135] This example provides a modified asphalt with a full-life-cycle self-purifying function, which is made from the following raw materials by weight: 84 parts of road asphalt, 12 parts of purifying modifier, and 4 parts of coupling agent.

[0136] The porous core-shell structure purifying modifier is made from the following raw materials: 100 parts of tourmaline anion powder, 55 parts of graphene alkyne, 21 parts of tetraethyl orthosilicate, 3 parts of calcium carbonate powder, 20 parts of Yb2BiSbO7 / CdBiYO4 heterojunction compound, 5 parts of phthalocyanine, 20 parts of nano-onion carbon, 50 parts of dispersant I, and 37.5 parts of dispersant II.

[0137] In this example:

[0138] The particle size of the tourmaline negative ion powder is 8000 mesh, and the negative ion release amount is 2000 ions.

[0139] The thickness of the graphdiyne is 0.7 μm, and the pore diameter is 3.8 Å.

[0140] The diameter of the nano calcium carbonate is 5 nm.

[0141] The diameter of the Yb2BiSbO7 / CdBiYO4 heterojunction compound is 1.4 μm.

[0142] The diameter of the nano onion-like carbon is 10 nm.

[0143] The road asphalt is 70 # base asphalt.

[0144] The dispersant I is isomeric tridecyl alcohol polyoxyethylene ether, and the dispersant II is ethylene glycol.

[0145] The coupling agent is a silane coupling agent.

[0146] In step one, isomeric tridecyl alcohol polyoxyethylene ether is added to the deionized aqueous solution of tourmaline negative ion powder, and the reaction is carried out at room temperature for 11 h; n-hexane is added to the deionized aqueous solution of the Yb2BiSbO7 / CdBiYO4 heterojunction compound, and the reaction is carried out at room temperature for 11 h, with stirring every 1 h.

[0147] In step 203, the obtained subphthalocyanine solution is ultrasonically treated for 22 min.

[0148] In step 204, the dried composite is transferred to a muffle furnace at 253 °C and calcined for 2.5 h to obtain a nano onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite core.

[0149] In step 301, the nano onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite core is placed in ethanol, ultrasonically dispersed for 20 min, then 12.5 wt.% ammonia water solution is added and stirred evenly, and the pre-treated tetraethyl orthosilicate solution in step one is added dropwise, stirred at room temperature for 1 h and aged at room temperature for 21 h to obtain a nano onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2 core-shell microsphere solution.

[0150] In step 302, the nano onion-like carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2 core-shell microsphere solution obtained in step 301 is placed in a stainless steel reaction kettle with a polytetrafluoroethylene lining and sintered at a high temperature of 173 °C for 1.7 h to obtain core-shell microspheres.

[0151] In step 401, graphdiyne is added into ethanol and ultrasonically dispersed for 25 min. The treated tourmaline anion powder from step one is added into the graphdiyne solution and stirred evenly to obtain a graphdiyne / tourmaline anion powder solution;

[0152] In step 404, graphdiyne / tourmaline anion powder composite powder and calcium carbonate powder are added into the SiO2 shell core-shell microsphere solution obtained in step three and stirred evenly. Ethylene glycol is added dropwise and ultrasonically dispersed for 20 min to obtain a SiO2 shell core-shell microsphere / graphdiyne and tourmaline anion powder composite / calcium carbonate mixed solution;

[0153] In this embodiment, the HCl solution in step 406 is a 15 wt.% HCl solution, and the NaOH solution in step five is a 10 wt.% NaOH solution.

[0154] In step six, the shear rate of low-speed stirring is 1050 rpm, and the high-speed shear rate is 3250 rpm.

[0155] The preparation method of the modified asphalt with the full-life-cycle self-purification function in this embodiment is the same as that in Example 1.

[0156] Example 3

[0157] This embodiment provides a modified asphalt with the full-life-cycle self-purification function, which is made of the following raw materials in parts by weight: 84 parts of road asphalt, 12 parts of purification modifier, and 4 parts of coupling agent.

[0158] The porous core-shell structure purification modifier is made of the following raw materials: 100 parts of tourmaline anion powder, 47 parts of graphdiyne, 23 parts of tetraethyl orthosilicate, 5 parts of calcium carbonate powder, 25 parts of Yb2BiSbO7 / CdBiYO4 heterojunction compound, 7.5 parts of subphthalocyanine, 22.5 parts of nano-onion carbon, 46 parts of dispersant I, and 39 parts of dispersant II.

[0159] In this embodiment:

[0160] The particle size of the tourmaline anion powder is 8000 mesh, and the anion release amount is 8000 ions.

[0161] The thickness of the graphdiyne is 0.9 μm, and the pore diameter is 3.9 Å.

[0162] The diameter of the nano-calcium carbonate is 27.5 nm.

[0163] The diameter of the Yb2BiSbO7 / CdBiYO4 heterojunction compound is 1.7 μm.

[0164] The diameter of the nano-onion carbon is 30 nm.

[0165] The road asphalt described is 70# base asphalt.

[0166] The dispersant I is isomeric tridecyl alcohol polyoxyethylene ether, and the dispersant II is ethylene glycol.

[0167] The coupling agent described is a silane coupling agent.

[0168] In step one, isomeric tridecyl alcohol polyoxyethylene ether is added to the deionized aqueous solution of tourmaline anion powder, and the reaction is carried out at room temperature for 12 h; n-hexane is added to the deionized aqueous solution of the Yb2BiSbO7 / CdBiYO4 heterojunction compound, and the reaction is carried out at room temperature for 10 h, with stirring once every 1 h.

[0169] In step 203, the obtained subphthalocyanine solution is ultrasonicated for 25 min.

[0170] In step 204, the dried composite is transferred to a muffle furnace at 255 °C and calcined for 25 h to obtain a nano-onion carbon Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite core.

[0171] In step 301, the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite core is placed in ethanol, ultrasonicated and dispersed for 20 min, then 15 wt.% ammonia water solution is added and stirred evenly, and the pre-treated tetraethyl orthosilicate solution in step one is added dropwise, stirred at room temperature for 1 h and aged at room temperature for 18 h to obtain a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2 core-shell microsphere solution.

[0172] In step 302, the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2 core-shell microsphere solution obtained in step 301 is placed in a stainless steel reaction kettle with a polytetrafluoroethylene lining and sintered at a high temperature of 170 °C for 2 h to obtain core-shell microspheres.

[0173] In step 401, graphdiyne is added to ethanol, ultrasonicated and dispersed for 20 min, and the pre-treated tourmaline anion powder in step one is added to the graphdiyne solution and stirred evenly to obtain a graphdiyne / tourmaline anion powder solution.

[0174] In step 404, the graphdiyne / tourmaline anion powder composite powder and calcium carbonate powder are added to the SiO2 outer shell core-shell microsphere solution obtained in step three and stirred evenly, and ethylene glycol is added dropwise and ultrasonicated and dispersed for 25 min to obtain a SiO2 outer shell core-shell microsphere / graphdiyne and tourmaline anion powder composite / calcium carbonate mixed solution.

[0175] The HCl solution in step 406 of this embodiment is a 12 wt.% HCl solution, and the NaOH solution in step 5 is a 7 wt.% NaOH solution.

[0176] In step 6, the shear rate of low-speed stirring is 1200 rpm, and the high-speed shear rate is 3500 rpm.

[0177] The preparation method of the modified asphalt with the full-life-cycle self-purification function in this embodiment is the same as that in Embodiment 1.

[0178] Embodiment 4

[0179] This embodiment provides a modified asphalt with the full-life-cycle self-purification function, which is made of the following raw materials in parts by weight: 84 parts of road asphalt, 12 parts of purification modifier, and 4 parts of coupling agent.

[0180] The porous core-shell structure purification modifier is made of the following raw materials: 100 parts of tourmaline negative ion powder, 51 parts of graphdiyne, 20 parts of tetraethyl orthosilicate, 4 parts of calcium carbonate powder, 30 parts of Yb2BiSbO7 / CdBiYO4 heterojunction compound, 10 parts of subphthalocyanine, 25 parts of nano-onion carbon, 47.5 parts of dispersant I, and 35 parts of dispersant II.

[0181] In this embodiment:

[0182] The particle size of the tourmaline negative ion powder is 6000 mesh, and the negative ion release amount is 5000 ions.

[0183] The thickness of the graphdiyne is 1.3 μm, and the pore diameter is 4 Å.

[0184] The diameter of the nano-calcium carbonate is 30 nm.

[0185] The diameter of the Yb2BiSbO7 / CdBiYO4 heterojunction compound is 1.6 μm.

[0186] The diameter of the nano-onion carbon is 40 nm.

[0187] The road asphalt is 70 # base asphalt.

[0188] The dispersant I is isomeric tridecyl alcohol polyoxyethylene ether, and the dispersant II is ethylene glycol.

[0189] The coupling agent is a silane coupling agent.

[0190] In Step 1, isomeric tridecyl alcohol polyoxyethylene ether is added to the deionized aqueous solution of tourmaline negative ion powder, and the reaction is carried out at room temperature for 11 h; n-hexane is added to the deionized aqueous solution of Yb2BiSbO7 / CdBiYO4 heterojunction compound, and the reaction is carried out at room temperature for 12 h, with stirring every 1 h.

[0191] In Step 203, the obtained subphthalocyanine solution is ultrasonicated for 23 min.

[0192] In Step 204, the dried composite is transferred to a muffle furnace at 252 °C and calcined for 2.2 h to obtain a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite core.

[0193] In Step 301, the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite core is placed in ethanol, ultrasonically dispersed for 20 min, then 13 wt.% ammonia water solution is added and stirred evenly, and the pre-treated tetraethyl orthosilicate solution in Step 1 is added dropwise, stirred at room temperature for 1 h and aged at room temperature for 23 h to obtain a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2 core-shell microsphere solution.

[0194] In Step 302, the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine composite@SiO2 core-shell microsphere solution obtained in Step 301 is placed in a stainless steel reaction kettle with a polytetrafluoroethylene lining and sintered at a high temperature of 170 °C for 1.8 h to obtain core-shell microspheres.

[0195] In Step 401, graphdiyne is added to ethanol and ultrasonically dispersed for 28 min, and the pre-treated tourmaline negative ion powder in Step 1 is added to the graphdiyne solution and stirred evenly to obtain a graphdiyne / tourmaline negative ion powder solution.

[0196] In Step 404, graphite diyne / tourmaline negative ion powder composite powder and calcium carbonate powder are added to the SiO2 outer shell core-shell microsphere solution obtained in Step 3 and stirred evenly, and ethylene glycol is added dropwise and ultrasonically dispersed for 22 min to obtain a SiO2 outer shell core-shell microsphere / graphite diyne and tourmaline negative ion powder composite / calcium carbonate mixed solution.

[0197] The HCl solution in Step 406 of this example is a 12.5 wt.% HCl solution, and the NaOH solution in Step 5 is a 7.5 wt.% NaOH solution.

[0198] In Step 6, the shear rate of low-speed stirring is 1000 rpm, and the high-speed shear rate is 3300 rpm.

[0199] The preparation method of the modified asphalt with the full-life-cycle self-purification function in this embodiment is the same as that in Example 1.

[0200] Example 5

[0201] This embodiment provides a modified asphalt with the full-life-cycle self-purification function, which is made from the following raw materials by weight: 84 parts of road asphalt, 12 parts of purification modifier, and 4 parts of coupling agent.

[0202] The porous core-shell structure purification modifier is made from the following raw materials: 100 parts of tourmaline anion powder, 53 parts of graphdiyne, 25 parts of tetraethyl orthosilicate, 3 parts of calcium carbonate powder, 22 parts of Yb2BiSbO7 / CdBiYO4 heterojunction compound, 6 parts of subphthalocyanine, 21 parts of nano-onion carbon, 45 parts of dispersant I, and 40 parts of dispersant II.

[0203] In this embodiment:

[0204] The particle size of the tourmaline anion powder is 8000 mesh, and the anion release amount is 4000 ions.

[0205] The thickness of the graphdiyne is 1.5 μm, and the pore diameter is 4.1 Å.

[0206] The diameter of the nano-calcium carbonate is 50 nm.

[0207] The diameter of the Yb2BiSbO7 / CdBiYO4 heterojunction compound is 1.9 μm.

[0208] The diameter of the nano-onion carbon is 30 nm.

[0209] The road asphalt is 70# base asphalt.

[0210] The dispersant I is isomeric tridecyl alcohol polyoxyethylene ether, and the dispersant II is ethylene glycol.

[0211] The coupling agent is a silane coupling agent.

[0212] The HCl solution in step 406 of this embodiment is a 13 wt.% HCl solution, and the NaOH solution in step 5 is an 8 wt.% NaOH solution.

[0213] The preparation method of the modified asphalt with the full-life-cycle self-purification function in this embodiment is the same as that in Example 1.

[0214] Example 6

[0215] This embodiment provides a modified asphalt with the full-life-cycle self-purification function, which is made from the following raw materials by weight: 84 parts of road asphalt, 12 parts of purification modifier, and 4 parts of coupling agent.

[0216] The described porous core-shell structure purification modifier is made from the following raw materials: 100 parts of tourmaline negative ion powder, 49 parts of graphdiyne, 22 parts of tetraethyl orthosilicate, 4 parts of calcium carbonate powder, 28 parts of Yb2BiSbO7 / CdBiYO4 heterojunction compound, 9 parts of subphthalocyanine, 24 parts of nano-onion carbon, 49 parts of dispersant I, and 38 parts of dispersant II.

[0217] In this embodiment:

[0218] The described tourmaline negative ion powder has a particle size of 7000 mesh and a negative ion release amount of 5000 ions.

[0219] The described graphdiyne has a thickness of 1.1 μm and a pore diameter of 4.1 Å.

[0220] The described nano-calcium carbonate has a diameter of 20 nm.

[0221] The described Yb2BiSbO7 / CdBiYO4 heterojunction compound has a diameter of 1.8 μm.

[0222] The described nano-onion carbon has a diameter of 40 nm.

[0223] The described road asphalt is 70# base asphalt.

[0224] The described dispersant I is isomeric tridecyl alcohol polyoxyethylene ether, and the dispersant II is ethylene glycol.

[0225] The described coupling agent is a silane coupling agent.

[0226] The HCl solution in step 406 of this embodiment is an 11 wt.% HCl solution, and the NaOH solution in step five is a 6 wt.% NaOH solution.

[0227] The preparation method of the modified asphalt with the full-life-cycle self-purification function in this embodiment is the same as that in Example 1.

[0228] Example 7

[0229] This embodiment provides a modified asphalt with the full-life-cycle self-purification function, which is made from the following raw materials in parts by weight: 84 parts of road asphalt, 12 parts of purification modifier, and 4 parts of coupling agent.

[0230] The described porous core-shell structure purification modifier is made from the following raw materials: 100 parts of tourmaline negative ion powder, 45 parts of graphdiyne, 23 parts of tetraethyl orthosilicate, 3 parts of calcium carbonate powder, 24 parts of Yb2BiSbO7 / CdBiYO4 heterojunction compound, 7 parts of subphthalocyanine, 22 parts of nano-onion carbon, 47 parts of dispersant I, and 37 parts of dispersant II.

[0231] In this embodiment:

[0232] The particle size of the tourmaline negative ion powder is 8000 mesh, and the negative ion release amount is 5000 ions.

[0233] The thickness of the graphdiyne is 0.8 μm, and the pore size is 3.9 Å.

[0234] The diameter of the nano calcium carbonate is 40 nm.

[0235] The diameter of the Yb2BiSbO7 / CdBiYO4 heterojunction compound is 1.5 μm.

[0236] The diameter of the nano onion carbon is 20 nm.

[0237] The road asphalt is 70# matrix asphalt.

[0238] The dispersant I is isomeric tridecanol polyoxyethylene ether, and the dispersant II is ethylene glycol.

[0239] The coupling agent is a silane coupling agent.

[0240] The HCl solution in step 406 of this embodiment is a 14 wt.% HCl solution, and the NaOH solution in step five is a 9 wt.% NaOH solution.

[0241] The preparation method of the modified asphalt with the full life cycle self-purification function in this embodiment is the same as that in Example 1.

[0242] Example 8

[0243] This embodiment provides a modified asphalt with the full life cycle self-purification function, which is made of the following raw materials by mass: 88 parts of road asphalt, 9 parts of purification modifier, and 3 parts of coupling agent.

[0244] The porous core-shell structure purification modifier is made of the following raw materials: 100 parts of tourmaline negative ion powder, 50 parts of graphdiyne, 24 parts of tetraethyl orthosilicate, 5 parts of calcium carbonate powder, 27 parts of Yb2BiSbO7 / CdBiYO4 heterojunction compound, 8 parts of subphthalocyanine, 23 parts of nano onion carbon, 48 parts of dispersant I, and 36 parts of dispersant II.

[0245] The selection and specifications of the raw materials in this embodiment are the same as those in Example 1.

[0246] The preparation method of the modified asphalt with the full life cycle self-purification function in this embodiment is the same as that in Example 1.

[0247] Example 9

[0248] This embodiment provides a modified asphalt with a self-purification function throughout its life cycle. It is made from the following raw materials in parts by mass: 80 parts of road asphalt, 15 parts of purification modifier, and 5 parts of coupling agent.

[0249] The porous core-shell structure purification modifier is made from the following raw materials: 100 parts of tourmaline negative ion powder, 50 parts of graphdiyne, 24 parts of tetraethyl orthosilicate, 5 parts of calcium carbonate powder, 27 parts of Yb2BiSbO7 / CdBiYO4 heterojunction compound, 8 parts of subphthalocyanine, 23 parts of nano-onion carbon, 48 parts of dispersant I, and 36 parts of dispersant II.

[0250] The selection and specifications of the raw materials in this embodiment are the same as those in Embodiment 1.

[0251] The preparation method of the modified asphalt with a self-purification function throughout its life cycle in this embodiment is the same as that in Embodiment 1.

[0252] Comparative Example 1

[0253] This comparative example provides a modified asphalt. The difference from Embodiment 1 is that in this comparative example, 12 parts of a single nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex are used to equivalently replace 12 parts of the purification modifier in Embodiment 1.

[0254] The preparation method of the modified asphalt in this comparative example is basically the same as that in Embodiment 1.

[0255] Comparative Example 2

[0256] This comparative example provides a modified asphalt. The difference from Embodiment 1 is that in this comparative example, 12 parts of a single nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2 core-shell microspheres are used to equivalently replace 12 parts of the purification modifier in Embodiment 1.

[0257] The selection and specifications of the raw materials in this comparative example are the same as those in Embodiment 1.

[0258] The preparation method of the modified asphalt in this comparative example is basically the same as that in Embodiment 1.

[0259] Comparative Example 3

[0260] This comparative example provides a modified asphalt. The difference from Embodiment 1 is that in this comparative example, 12 parts of a single nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2@graphdiyne / tourmaline negative ion powder composite porous solid core-shell microspheres are used to equivalently replace 12 parts of the purification modifier in Embodiment 1.

[0261] The selection and specifications of the raw materials in this comparative example are the same as those in Embodiment 1.

[0262] The preparation method of the modified asphalt in this comparative example is basically the same as that in Example 1.

[0263] Comparative Example 4

[0264] This comparative example provides a modified asphalt. The difference from Example 1 is that in this comparative example, 8 parts of tourmaline negative ion powder and 4 parts of graphdiyne are used to make a tourmaline negative ion powder / graphdiyne composite hollow microsphere, which is used to equally replace 12 parts of the purification modifier in Example 1.

[0265] The selection and specifications of the raw materials in this comparative example are the same as those in Example 1.

[0266] The preparation method of the modified asphalt in this comparative example is to stir the tourmaline negative ion powder / graphdiyne hollow microsphere evenly in the asphalt heated to 160 ± 5 °C.

[0267] The preparation method of the tourmaline negative ion powder / graphdiyne hollow microsphere in this comparative example is carried out according to the following steps:

[0268] Step 1, perform the pretreatment of the tourmaline negative ion powder and the preparation of the tetraethyl orthosilicate solution according to the preparation steps in Example 1;

[0269] Step 2, preparation of SiO2 microspheres:

[0270] According to the mass ratio of cetyltrimethylammonium bromide to tetraethyl orthosilicate of 1:4, add 0.015 mol / L of cetyltrimethylammonium bromide to 0.1 - 0.15 mol / L of tetraethyl orthosilicate solution and stir evenly. While stirring, add 0.1 - 0.15 mol / L of diethanolamine solution drop by drop according to the mass ratio of diethanolamine to tetraethyl orthosilicate of 1:15. Stir for 1 h, let it stand for 12 h. After the reaction is completed, wash it with deionized water twice and ethanol twice respectively. Place the washed microsphere solution in an oven at 60 °C and dry it to constant weight. Place the dried microsphere powder in a muffle furnace and calcine it at 550 °C for 2 h to obtain SiO2 microspheres;

[0271] Step 3, preparation of SiO2@tourmaline negative ion powder / graphdiyne composite porous microspheres:

[0272] Step 301, add graphdiyne into ethanol, ultrasonically disperse it for 20 - 30 min, add the pretreated tourmaline negative ion powder in Step 1 into the graphdiyne solution and stir evenly to obtain a graphdiyne / tourmaline negative ion powder solution;

[0273] Step 302, place the graphdiyne / tourmaline negative ion powder solution in a planetary high-energy ball mill, with the ball milling speed of 200 rpm and the ball milling time of 2 h. Complete the ball milling process to obtain a graphdiyne / tourmaline negative ion powder composite solution;

[0274] Step 303: Take out the ball-milled graphite alkyne / tourmaline anion powder composite solution, place it in an oven at 180°C - 185°C and dry it to constant weight. Take out the dried solid product, grind, sieve and disperse it to obtain the graphite alkyne / tourmaline anion powder composite powder.

[0275] Step 304: Add the graphite alkyne / tourmaline anion powder composite powder and calcium carbonate powder to the SiO2 microsphere solution obtained in Step 3, stir evenly, add ethylene glycol and ultrasonically disperse for 20 - 30 min to obtain the SiO2 microsphere / graphite alkyne and tourmaline anion powder composite / calcium carbonate mixed solution.

[0276] Step 305: Place the SiO2 microsphere / graphite alkyne and tourmaline anion powder composite / calcium carbonate mixed solution in a planetary high-energy ball mill, with a ball milling speed of 200 rpm and a ball milling time of 2 h. Take out the ball-milled mixed solution, place it in an oven at 180°C - 185°C and dry it to constant weight. Take out the dried solid product, grind, sieve and disperse it to obtain the SiO2@graphite alkyne / tourmaline anion powder composite / calcium carbonate core-shell microspheres.

[0277] Step 306: Place the core-shell microspheres obtained in Step 305 in deionized water and stir evenly, then add 10 wt.% - 15 wt.% HCl solution, react at room temperature for 12 h, stir once every 1 h. After the reaction is completed, wash twice with deionized water and place it in deionized water to obtain the SiO2@graphite alkyne / tourmaline anion powder composite porous core-shell microsphere solution.

[0278] Step Four: Preparation of tourmaline anion powder / graphite alkyne composite hollow microspheres:

[0279] Add 5 wt.% NaOH solution to the SiO2@graphite alkyne / tourmaline anion powder porous core-shell microsphere solution, react for 12 h, stir once every 1 h. After the reaction is completed, wash three times with deionized water and once with ethanol respectively. Place the washed microsphere solution in an oven at 60°C and dry it to constant weight. After sieving and dispersing, obtain the tourmaline anion powder / graphite alkyne composite hollow microspheres.

[0280] Comparative Example 5

[0281] This comparative example gives a modified asphalt, which is different from Example 1 in that in this comparative example, 8 parts of tourmaline and 4 parts of graphite alkyne are used to make tourmaline / graphite alkyne composite hollow microspheres to equivalently replace 12 parts of the purification modifier in Example 1.

[0282] The selection and specifications of the raw materials in this comparative example are the same as those in Example 1.

[0283] The preparation method of the modified asphalt in this comparative example is the same as that in Comparative Example 4.

[0284] Comparative Example 6

[0285] This comparative example provides an asphalt, namely 70 # asphalt, and a commercially available product can be specifically used.

[0286] Comparative Example 7

[0287] This comparative example provides an asphalt, namely SBS asphalt, and a commercially available product can be specifically used.

[0288] Comparative Example 8

[0289] This comparative example provides an asphalt, namely SBR modified asphalt, and a commercially available product can be specifically used.

[0290] Second part:

[0291] The performance test of self-purifying modified asphalt includes three parts: the basic performance test of self-purifying modified asphalt, the emission reduction effect and the purification effect test. According to the test procedures of "Highway Engineering Asphalt and Asphalt Mixtures" (JTGE20 - 2011), the three major indicators of self-purifying modified asphalt are measured to clarify the change law of the road performance of self-purifying modified asphalt; the emissions of harmful substances in the whole life cycle of asphalt pavement are tested, and the asphalt fume emission reduction rate and vehicle exhaust purification rate of asphalt pavement in the construction period, operation period and maintenance period are calculated to explore the environmental effects such as emission reduction and purification of self-purifying modified asphalt.

[0292] (1) Basic performance:

[0293] It can be seen from Figures 1a to 2c that the basic road performance such as penetration, ductility and softening point of self-purifying modified asphalt all meet the relevant technical requirements of "Technical Specifications for Construction of Highway Asphalt Pavement" (JTG F40 - 2004) and can be used in the road field.

[0294] Compared with the base asphalt, the softening point and ductility of self-purifying modified asphalt are higher, indicating that the high-temperature performance and low-temperature performance of self-purifying modified asphalt are both superior to those of the base asphalt.

[0295] By comparing Examples 2, 3, 5, and 7, it can be found that the softening point of the self-purifying modified asphalt gradually decreases as the release amount of tourmaline negative ions increases. This is because tourmaline negative ion powder has thermoelectric properties, and when the temperature changes, it releases charges to form an electrostatic field. The electrostatic field is very unstable at high temperatures, which in turn affects the high-temperature stability of the asphalt. The higher the release amount of negative ions, the worse the high-temperature performance of the asphalt, and the ductility and low-temperature performance show the opposite trend. By comparing Examples 1, 4, and 6, it can be found that the softening point of the self-purifying modified asphalt gradually increases as the mesh number of tourmaline negative ion powder increases. This is because tourmaline powder can absorb the soft components in the asphalt, increase the viscosity of the asphalt, and cause the softening point to rise. The larger the mesh number of tourmaline negative ion powder, the more obvious the influence on the asphalt components, the greater the viscosity of the asphalt, and the better the high-temperature stability.

[0296] After thin film oven + ultraviolet aging, compared with each comparative example, Example 1 has a higher penetration residue ratio, a smaller softening point increment, and the smallest ductility reduction. The changes in the three major indicators are small, indicating that the self-purifying modified asphalt has better high- and low-temperature stability compared with the matrix asphalt, SBS modified asphalt, and SBR modified asphalt, and can better meet the long-term stable use of asphalt pavements.

[0297] (2)Emission reduction efficacy:

[0298] To comprehensively evaluate the emission reduction efficacy of the self-purifying modified asphalt throughout its life cycle, it is necessary to test the emission reduction efficacy during the construction and operation stages of the asphalt pavement and the emission reduction efficacy during the maintenance period of the asphalt pavement. The calculation method for the emission reduction rate of asphalt mixtures at different stages is shown in Equation (1), and the test results are shown in Table 1, Figure 3 and Figure 4 as shown.

[0299] (1);

[0300] In the formula:

[0301] is the emission reduction rate of asphalt fume of the self-purifying modified asphalt mixture at different stages.

[0302] is the emission concentration of asphalt fume of ordinary hot mix asphalt mixture at different stages.

[0303] is the emission concentration of asphalt fume of the self-purifying modified asphalt mixture at different stages.

[0304] Table 1 Emission reduction efficacy of each example and comparative examples 1 - 5 throughout the life cycle

[0305]

[0306] From Figure 3It can be seen that in Examples 1-9, the emission reduction rate during the construction period of the asphalt pavement is 53.37% - 64.57%, the emission reduction rate during the operation period of the asphalt pavement is 48.67% - 61.22%, and the emission reduction rate during the maintenance period of the asphalt pavement is 45.03% - 57.73%. The emission reduction rate in each pollutant emission stage is greater than 45%. The self-purifying asphalt has excellent emission reduction ability. With the extension of the life cycle, the self-purifying modified asphalt shows good anti-decay ability, and the maximum emission reduction decay rate is 15.63% of Example 2, indicating that the self-purifying modified asphalt prepared by the present invention has excellent emission reduction effect of asphalt fume in the whole life cycle.

[0307] (3)Purification effect:

[0308] The purification effect refers to the absorption and degradation of main gaseous pollutants such as CO X , HC and NO X in vehicle exhaust during the operation period of the asphalt pavement. To determine the purification effect of the self-purifying modified asphalt developed by the present invention, the exhaust gas concentration before and after absorption and degradation by the self-purifying modified asphalt mixture was measured, and the purification rate was calculated according to formula (2). The test results are as Figure 5 and Figure 6 shown.

[0309] (2);

[0310] In the formula:

[0311] is the purification rate of vehicle exhaust.

[0312] is the initial emission concentration of vehicle exhaust.

[0313] is the concentration of vehicle exhaust after absorption and degradation by the self-purifying modified asphalt mixture.

[0314] Table 2 Emission reduction effect of vehicle exhaust in each example and Comparative Examples 1-5

[0315]

[0316] It can be Figure 5 seen that the exhaust gas purification rate of each example is 41.97% - 52.32%, and the exhaust gas purification effect is excellent. Among them, the exhaust gas purification rate of Example 1 is the highest, which is 52.32%, and the exhaust gas purification effect is the best. Moreover, the exhaust gas purification rate of the self-purifying asphalt in the examples shows the same law as the asphalt fume emission reduction effect. The reason is that the components of vehicle exhaust are the same as some components of asphalt fume. The modified asphalt with self-purifying function in the whole life cycle of the present invention absorbs and degrades CO X , HC and NO XTail gas purification is achieved, and its tail gas purification mechanism is similar to the bitumen fume emission reduction mechanism.

[0317] Part Three:

[0318] It can be seen from Figures 1a to 2c that compared with the matrix asphalt, the softening point and ductility of the purified modified asphalt are higher, indicating that the high-temperature performance and low-temperature performance of the purified modified asphalt are superior to those of the matrix asphalt. After thin film oven + ultraviolet aging, Example 1 has a higher penetration residue ratio, a smaller softening point increment, and the smallest ductility reduction compared with each comparative example. The changes in the three major indicators are small, indicating that the purified modified asphalt has better high- and low-temperature stability than the matrix asphalt, SBS modified asphalt, and SBR modified asphalt, and can better meet the long-term stable use of asphalt pavements.

[0319] As Figure 3 shown, by comparing Examples 1 - 7, it can be found that the bitumen fume emission reduction effect first increases and then decreases with the increase in the dosages of graphdiyne, Yb2BiSbO7 / CdBiYO4 heterojunction compound, subphthalocyanine, and nano-onion carbon, and the change range is large. By comparing Examples 1, 4, and 6, it can be found that the bitumen fume emission reduction effect gradually decreases with the decrease in the dosages of tetraethyl orthosilicate and calcium carbonate powder, and the change range is small. By comparing Examples 1, 8, and 9, it can be found that the bitumen fume emission reduction effect first increases and then decreases with the increase in the dosages of the purified modifier and coupling agent, and the change range is large. By comparing Examples 2, 3, 5, and 7, it can be found that the bitumen fume emission reduction effect gradually increases with the increase in the negative ion release amount of tourmaline negative ion powder, and the change range is large. Although the bitumen fume emission reduction effect gradually increases with the increase in the release amount of tourmaline negative ion powder, the high-temperature stability of the asphalt also decreases. To ensure the good road performance of the asphalt, it is best to select tourmaline negative ion powder with a negative ion release amount of 5000 ions. Among them, Example 1 has the best full-life cycle bitumen fume emission reduction effect, which is 64.57% during the construction period of the asphalt pavement, 61.22% during the operation period of the asphalt pavement, and 57.73% during the maintenance period of the asphalt pavement. Therefore, Example 1 with a purified modifier dosage of 12% and a coupling agent dosage of 4% is preferably selected as the best emission reduction effect example.

[0320] It can be seen from Figure 4It can be seen that the emission reduction efficacy of Comparative Example 1 showed a significant decline compared to Example 1 at each stage. The emission reduction rate of Comparative Example 2 was within 2%. The emission reduction rate of Comparative Example 3 was lower than that of Example 1 at each stage, and the emission reduction rate decreased significantly as the life cycle of the asphalt pavement progressed. By the maintenance period of the asphalt pavement, the emission reduction rate was only 22.57%. This is because in Comparative Example 1, a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex core was used as the purification modifier, and only nano-onion carbon adsorbed the asphalt fume. When Comparative Example 2 used a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2 core-shell microsphere purification modifier, the SiO2 outer shell formed a closed layer and had no adsorption and degradation effect, resulting in an almost zero emission reduction efficacy for the asphalt fume. When Comparative Example 3 used a nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / subphthalocyanine complex@SiO2@graphdiyne / tourmaline negative ion powder complex porous solid core-shell microsphere as the emission reduction agent, the presence of the SiO2 shell only allowed the graphdiyne / tourmaline negative ion powder complex outer shell to exert an adsorption and degradation effect, which was prone to adsorption saturation, thus resulting in a significant attenuation of the emission reduction rate as the life cycle progressed. Therefore, using a single core or a tourmaline negative ion powder / graphdiyne complex porous solid microsphere as the emission reduction agent resulted in poor emission reduction efficacy for the modified asphalt.

[0321] Comparative Example 4 was a tourmaline negative ion powder / graphdiyne complex hollow microsphere structure purification modifier. The difference between Comparative Example 5 and Comparative Example 4 was that tourmaline was used instead of the tourmaline negative ion powder. The emission reduction efficacy of Comparative Example 5 decreased at each stage compared to Comparative Example 4. The reason is that the tourmaline negative ion powder has a greater negative ion release amount, a greater polarization effect, and a stronger adsorption and sedimentation effect on pollutants compared to tourmaline.

[0322] By comparing Comparative Example 4 with Comparative Examples 1-3, the emission reduction rate of the tourmaline anion powder / graphdiyne composite hollow microsphere structure purification modifier is higher than that of the single-core purification modifier and the tourmaline anion powder / graphdiyne composite porous solid microsphere purification modifier. However, its emission reduction rate is only 28.22% - 39.43%, and the emission reduction rate also shows a significant attenuation as the life cycle of the asphalt pavement progresses. In contrast, the asphalt fume emission reduction rate of Example 1 reaches 57.73% - 64.57% at each stage, with an increase in the emission reduction rate of 25.14% - 29.51% compared to Comparative Example 4, and the minimum attenuation amplitude is 6.84% as the life cycle progresses. This is because the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine complex@graphdiyne / tourmaline anion powder composite porous core-shell purification modifier used in the present invention can effectively degrade and adsorb the asphalt fumes adsorbed into the cavity, realizing core-shell synergistic emission reduction, solving the problems of blockage and saturation of traditional adsorption materials, and thus achieving efficient adsorption, degradation, and purification of pollutants throughout the life cycle of the road.

[0323] It can be seen from Figure 6 that Comparative Example 2 is the nano-onion carbon / Yb2BiSbO7 / CdBiYO4 heterojunction compound / phthalocyanine complex@SiO2 core-shell microsphere modified asphalt, which has almost no tail gas purification effect. The tail gas purification rates of Comparative Examples 1 and 3 are 28.54% and 26.74% respectively, indicating that the modified asphalt prepared with the single-core and tourmaline anion powder / graphdiyne composite porous solid microsphere purification modifiers has a certain tail gas purification effect. The tail gas purification rate of Comparative Example 4 is 36.38%, indicating that the modified asphalt prepared with the tourmaline anion powder / graphdiyne composite hollow microsphere purification modifier has a better tail gas purification effect than the modified asphalt prepared with the single-core and tourmaline anion powder / graphdiyne composite porous solid microsphere purification modifiers. The tail gas purification rate of Comparative Example 5 is 23.78%, which is 12.6% lower than that of Comparative Example 4, indicating that tourmaline anion powder has a stronger adsorption and degradation ability for automobile tail gas than tourmaline. The tail gas purification rate of Example 1 is the best, at 52.32%, with an increase of 15.94% compared to Comparative Example 4. This is because the porous core-shell structure purification modifier prepared in the present invention realizes the synergistic purification of the catalyst inner core and the tourmaline anion powder / graphdiyne composite outer shell, solving the problem that the hot mix emission reduction asphalt at the present stage has not achieved the purification of automobile tail gas, and the prepared self-purifying modified asphalt has excellent automobile tail gas purification effect.

[0324] Part Four:

[0325] It should be noted that all raw materials in the present invention, without special instructions, are commonly used raw materials known in the art. The SBS modified asphalt or the rubber powder modified asphalt are both commonly used SBS modified asphalt or rubber powder modified asphalt known in the art.

[0326] The road asphalt described above is 70# base asphalt, 90# base asphalt, SBS modified asphalt or rubber powder modified asphalt.

[0327] The dispersant I is isomeric tridecyl alcohol polyoxyethylene ether, and the dispersant II is ethylene glycol.

[0328] The coupling agent is a silane coupling agent or a phthalate coupling agent.

[0329] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A porous core-shell purification modifier, characterized in that: The porous core-shell purification modifier is a spherical egg yolk-eggshell porous structure, comprising a shell and a core located in the shell, the shell is a graphyne / tourmaline negative ion powder composite, the shell has holes, the core is composed of a nano-onion carbon / heterojunction compound / subphthalocyanine composite, the heterojunction compound is Yb2BiSbO7 / CdBiYO4, and there is a cavity between the core and the shell.

2. A porous core-shell purification modifier according to claim 1, characterized in that: The diameter of the pore is 5-100 nm.

3. A method for preparing a porous core-shell purification modifier, characterized in that: The following steps are involved: Step 1, preparing a nano-onion carbon / heterojunction compound / subphthalocyanine composite core using nano-onion carbon, a heterojunction compound and subphthalocyanine, wherein the heterojunction compound is Yb2BiSbO7 / CdBiYO4; Step 2, using nano-onion carbon / heterojunction compound / subphthalocyanine composite core and ethyl orthosilicate solution to prepare SiO2 shell core-shell microsphere solution: Step 3, using graphyne, tourmaline anion powder, calcium carbonate powder, dispersant I, dispersant II and SiO2 shell core-shell microsphere solution to prepare nano onion carbon heterojunction compound / subphthalocyanine composite @ SiO2@graphyne / tourmaline anion powder composite porous core-shell microsphere solution; Step 4, using the nano onion carbon / heterojunction compound / subphthalocyanine complex@SiO2@graphite / tourmaline negative ion powder complex porous core-shell microsphere solution to prepare a nano onion carbon / heterojunction compound / subphthalocyanine complex@graphite / tourmaline negative ion powder complex porous core-shell structure purifier; In the steps 1 to 4, in parts by weight, there are 100 parts of tourmaline negative ion powder, 45-55 parts of graphyne, 20-25 parts of ethyl orthosilicate, 3-5 parts of calcium carbonate powder, 20-30 parts of heterojunction compound, 5-10 parts of subphthalocyanine, 20-25 parts of nano onion carbon, 45-50 parts of dispersant I and 35-40 parts of dispersant II.

4. The method for preparing a porous core-shell purification modifier according to claim 3, characterized in that: The step 1 comprises the following steps: Step 1.1, adding n-hexane to a deionized water solution of a heterojunction compound, reacting at room temperature, filtering out the powder after the reaction is completed, drying, and sieving to obtain a pretreated heterojunction compound; Step 1.2, placing the pretreated heterojunction compound in ethanol and ultrasonically dispersing it to form a mixed solution of nano-onion carbon and the heterojunction compound; Step 1.3, ball-milling the mixed solution of nano-onion carbon and heterojunction compound to obtain a nano-onion carbon / heterojunction compound composite solution; Step 1.4, placing subphthalocyanine in ethanol to obtain a subphthalocyanine solution, heating the nano-onion carbon / heterojunction compound complex solution, adding dropwise to the subphthalocyanine solution after ultrasound, and heating until the solution is completely volatilized to obtain a nano-onion carbon / heterojunction compound / subphthalocyanine complex; Step 1.5, drying the nano-onion carbon / heterojunction compound / subphthalocyanine complex to constant weight, taking out the dried solid product, grinding, sieving, dispersing, and calcining to obtain the nano-onion carbon heterojunction compound / subphthalocyanine complex core.

5. The method for preparing a porous core-shell purification modifier according to claim 3, characterized in that: The step 2 comprises the following steps: Step 2.1, placing tetraethyl orthosilicate in ethanol to obtain a tetraethyl orthosilicate solution; Step 2.2, placing the nano-onion carbon / heterojunction compound / subphthalocyanine complex core in ethanol, ultrasonically dispersing, then adding 10 wt.%~15 wt.% ammonia solution and stirring evenly, adding ethyl orthosilicate solution dropwise, stirring evenly at room temperature and aging at room temperature for 18~24h to obtain a nano-onion carbon heterojunction compound / subphthalocyanine complex @ SiO2 core-shell microsphere solution; Step 2.3, sintering the nano-onion carbon / heterojunction compound / subphthalocyanine composite @ SiO2 core-shell microsphere solution at 170°C~175°C for 1.5~2 h to obtain core-shell microspheres, washing the core-shell microspheres obtained by high-temperature sintering, and finally placing the core-shell microspheres in an ethanol solution to obtain a SiO2 shell core-shell microsphere solution.

6. The method for preparing a porous core-shell purification modifier according to claim 3, characterized in that: The step 3 comprises the following steps: Step 3.1, adding dispersant I to the deionized water solution of tourmaline negative ion powder, reacting at room temperature, filtering out the powder of tourmaline negative ion powder after the reaction is completed, and drying the powder of tourmaline negative ion powder to obtain pretreated tourmaline negative ion powder; Step 3.2, adding graphyne to ethanol and ultrasonically dispersing it to obtain a graphyne solution, adding tourmaline anion powder to the graphyne solution and stirring it evenly to obtain a graphyne / tourmaline anion powder solution; Step 3.3, ball-milling the Graphene Olefin / Tourmaline Anion Powder solution to obtain a Graphene Olefin / Tourmaline Anion Powder composite solution; Step 3.4, drying the Graphene Olefin / Tourmaline Anion Powder Composite Solution to obtain a solid product A, grinding, sieving and dispersing the solid product A to obtain a Graphene Olefin / Tourmaline Anion Powder Composite Powder; Step 3.5, adding Graphene / tourmaline anion powder composite powder and calcium carbonate powder to the SiO2 shell core-shell microsphere solution and stirring evenly, dropping dispersant II ethylene glycol and performing ultrasonic dispersion to obtain a SiO2 shell core-shell microsphere / graphene and tourmaline anion powder composite / calcium carbonate mixed solution; Step 3.6, ball-milling the SiO2 shell core-shell microspheres / graphite and tourmaline negative ion powder composite / calcium carbonate mixed solution and drying it to obtain a solid product B, grinding, sieving and dispersing the solid product B to obtain nano onion carbon / heterojunction compound / subphthalocyanine composite @ SiO2@graphite / tourmaline negative ion powder composite / calcium carbonate core-shell microspheres; Step 3.7, placing nano-onion carbon / heterojunction compound / subphthalocyanine complex @ SiO2@graphite / tourmaline negative ion powder complex / calcium carbonate core-shell microspheres in deionized water and stirring evenly, then adding 10 wt.%~15 wt.% HCl solution, reacting at room temperature, and then washing and placing in deionized water to obtain nano-onion carbon / heterojunction compound / subphthalocyanine complex @ SiO2@graphite / tourmaline negative ion powder complex porous core-shell microsphere solution.

7. The method for preparing a porous core-shell purification modifier according to claim 3, characterized in that: In parts by weight, the present invention comprises 100 parts of tourmaline negative ion powder, 50 parts of graphyne, 24 parts of ethyl orthosilicate, 5 parts of calcium carbonate powder, 27 parts of heterojunction compound, 8 parts of subphthalocyanine, 23 parts of nano-onion carbon, 48 parts of dispersant I and 36 parts of dispersant II.

8. A self-purifying modified asphalt, characterized in that: The invention is prepared from the following raw materials in parts by mass: 80 to 88 parts of road asphalt, 9 to 15 parts of a purification modifier, and 3 to 5 parts of a coupling agent. The sum of the parts by mass of the road asphalt, the purification modifier and the coupling agent is 100 parts. The purification modifier is the purification modifier according to claim 1.

9. The self-purifying modified asphalt according to claim 8, characterized in that: In terms of mass, there are 84 parts of road asphalt, 12 parts of purification modifier, and 4 parts of coupling agent.

10. A method for preparing self-purifying modified asphalt, characterized in that: The following steps are involved: Heat the road asphalt to 160±5°C, add the porous core-shell purification modifier and the silane coupling agent to the road asphalt, stir evenly, and obtain a self-purification functional modified asphalt; the road asphalt is 80-88 parts, the purification modifier is 9-15 parts, the coupling agent is 3-5 parts, the sum of the mass parts of the road asphalt, the purification modifier and the coupling agent is 100 parts, and the purification modifier is the purification modifier described in claim 1.

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