Cleaning modifier for directionally adsorbing harmful gases, modified asphalt and preparation method

Abstract

The present invention provides a cleaning modifier for directionally adsorbing harmful gases, modified asphalt and a preparation method thereof. The cleaning modifier includes bornite powder, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), methacryloyl chloride, polydivinylbenzene, adsorption base material A, and adsorption base material B. The adsorption base material A is carbon black, biochar, activated carbon, mesoporous silica or zeolite; the adsorption base material B is fly ash or diatomite. The modified asphalt includes road asphalt, a cleaning modifier, a dispersant and a coupling agent. The modified asphalt prepared by the present invention, which has the function of directionally adsorbing harmful gases in the road area, can achieve efficient cleaning of vehicle exhaust gas in the road area and harmful flue gas during the construction, operation and maintenance stages of asphalt pavements. Its cleaning effect is significantly improved compared with the existing single adsorption-type and purification-type modified asphalt, which is of great significance for reducing energy consumption and alleviating the pressure on road service and the ecological environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of road materials, relates to modified asphalt, and specifically relates to a cleaning modifier for directionally adsorbing harmful gases, modified asphalt and a preparation method thereof. Background Art

[0002] At present, the road construction in China mainly uses 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 generated by hot mix asphalt mixture pollutes the environment during the construction stage, and the emissions of volatile harmful substances from asphalt pavements and vehicle exhaust in the road area pollute the atmosphere during the operation stage. Existing research focuses on pollution reduction and carbon reduction technologies such as warm mix, hot mix emission reduction and photocatalytic purification of vehicle exhaust. However, the emission reduction effect or purification effect of related technologies still needs to be further improved. Adsorption-based functional additives designed according to the basic component characteristics of asphalt fume and vehicle exhaust have not been developed, and there are few reports on cleaning modified asphalt with cleaning ability covering the main harmful gases in the road area. Summary of the Invention

[0003] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a cleaning modifier for directionally adsorbing harmful gases, modified asphalt and a preparation method thereof, so as to solve the technical problems that the cleaning effect (emission reduction effect and / or purification effect) of environmental protection modified asphalt in the existing technology needs to be improved urgently and the cleaning ability is difficult to cover the main harmful gases in the road area.

[0004] To solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0005] A cleaning modifier is made from the following raw materials: bornite powder, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), methacryloyl chloride, polydivinylbenzene, adsorption base material A, adsorption base material B.

[0006] The adsorption base material A is carbon black, biochar, activated carbon, mesoporous silica or zeolite.

[0007] The adsorption base material B is fly ash or diatomite.

[0008] Preferably, in the cleaning modifier, the mass ratio of bornite powder, adsorption base material A, adsorption base material B, polydivinylbenzene to poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) is 2:0.8:1.2:0.1:0.05.

[0009] The present invention also protects a preparation method of the above-mentioned cleaning modifier, and the method is carried out according to the following steps:

[0010] Step 1, pretreatment of raw materials:

[0011] Add bornite powder to the methacryloyl chloride-deionized water solution, let it stand at room temperature, control the reaction time to be 3 h, stir it every 30 min during this period, and after the reaction is completed, filter out the powder and dry it for later use.

[0012] Place carbon black in a muffle furnace, set the temperature to 500 °C, keep the temperature for 2 h, then grind, sieve the obtained product and place it in a cetyltrimethylammonium bromide-deionized water solution, let it stand at room temperature, control the reaction time to be 3 h, stir it every 30 min during this period, and after the reaction is completed, filter out the powder and dry it for later use.

[0013] Soak fly ash in 0.1 mol / L hydrochloric acid solution for 6 h, then use deionized water to ultrasonically clean it multiple times until the pH value of the sample is neutral, and then filter it out and dry it for use.

[0014] Step two, preparation of the cleaning modifier:

[0015] Mix poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) with bornite powder in deionized water solution, use a high-speed shear instrument, set the shear speed to 2000 rpm, and the shear time to 30 min, then filter out the powder and dry it for later use.

[0016] Dissolve polydivinylbenzene with absolute ethanol, immerse carbon black in the polydivinylbenzene-absolute ethanol mixture for 4 h, and then place it in an oven at 60 °C for 6 h to obtain porous carbon black surface-modified with polydivinylbenzene.

[0017] Place fly ash in a planetary ball mill, use absolute ethanol as the ball milling medium, the ratio of material to liquid is 1:3, the ball milling rate is 600 rpm, and the ball milling time is 3 h. After the grinding is completed, filter out the powder and dry it for later use.

[0018] Mix carbon black, fly ash and bornite powder in deionized water solution, ultrasonically disperse for 2 h, the ultrasonic wave is 50 HZ, and then dry the bornite powder / carbon black / fly ash mixture at 50 °C and sieve it for later use to prepare the cleaning modifier.

[0019] The present invention also protects a modified asphalt, which is made from the following raw materials: road asphalt, cleaning modifier, dispersant and coupling agent.

[0020] The cleaning modifier described above is the cleaning modifier as described above.

[0021] Specifically, in terms of mass parts, it is made from the following raw materials: 85.5 - 89.5 parts of road asphalt, 4.5 - 8.5 parts of cleaning modifier, 2 parts of dispersant, 4 parts of coupling agent, and the sum of the weight parts of the raw materials is 100 parts.

[0022] Preferably, it is made of the following raw materials in parts by mass: 88.68 parts of road asphalt, 5.32 parts of cleaning modifier, 2 parts of dispersant, and 4 parts of coupling agent.

[0023] Preferably, the road asphalt is 70# base asphalt, 90# base asphalt, SBS modified asphalt or rubber powder modified asphalt.

[0024] Preferably, the dispersant is sodium dodecylbenzenesulfonate, sodium dodecyl sulfate or polyoxyethylene octadecylamine.

[0025] Preferably, the coupling agent is silane coupling agent or phthalate coupling agent.

[0026] The present invention also protects a preparation method of the modified asphalt as described above, and this method is carried out according to the following steps:

[0027] Heat the road asphalt to 160±5°C, slowly add the cleaning modifier and silane coupling agent to the road asphalt, first stir at a low speed with a stirrer for 8 min, the shear rate is 1000 - 1200 rpm, and then carry out high-speed shearing with a shearer for 25 min, the shear rate is 3000 - 3500 rpm, to obtain the modified asphalt with the function of directionally adsorbing harmful gases in the road area.

[0028] The cleaning modifier described above is prepared by the preparation method of the cleaning modifier as described above.

[0029] Compared with the prior art, the present invention has the following technical effects:

[0030] (Ⅰ) The pore structure of the existing porous adsorbents is mainly micropores - mesopores, and its pore structure does not match the molecular diameter of harmful substances in the road area. Aiming at nano - scale harmful substances such as VOC and inorganic small - molecule gases in the harmful gases in the road area, and micron - scale harmful substances such as PM2.5 fine particles, based on the molecular kinetic diameters of asphalt fumes and vehicle exhausts, a cleaning modifier with both micron - scale pore diameter and nano - scale pore diameter is designed to achieve the directional adsorption of main harmful gases in the road area such as asphalt fumes and vehicle exhausts.

[0031] (Ⅱ) Use poly(3,4 - ethylenedioxythiophene) - poly(styrenesulfonic acid) to modify bornite powder, which further enhances the ability of the thermoelectric material to degrade harmful substances. On the other hand, the polymer can inhibit the release of asphalt fumes by fixing the light components of the modified asphalt.

[0032] (Ⅲ) Use the liquid - phase deposition method to load polydivinylbenzene on carbon black, which improves its stability and further increases the specific surface area and pore volume of carbon black, and then the adsorption capacity for harmful gases in the road area.

[0033] (IV) The pore size distribution of fly ash was adjusted by the forced mechanical force in the high-energy ball milling process, making its nanoscale pore size distribution more inclined to mesopores, and specifically enhancing the adsorption capacity for severely harmful gases such as VOCs.

[0034] (V) The adsorption capacity of the porous material was improved by the self-electrostatic force of bornite powder; on the other hand, the polarization effect of the thermoelectric material continuously degraded the harmful substances in the pores, overcoming the adsorption saturation phenomenon and extending the service life of the cleaning modifier.

[0035] (VI) The porous material in the present invention provided a high-concentration harmful substance environment for bornite powder, improving the degradation efficiency of road area harmful gases. Finally, the prepared modified asphalt had a significant cleaning effect on asphalt fume and vehicle exhaust, and the cleaning function was long-term effective.

[0036] (VII) The modified asphalt prepared in the present invention with the function of directionally adsorbing road area harmful gases can achieve efficient cleaning of vehicle exhaust and harmful flue gases during the construction, operation, and maintenance stages of asphalt pavements. Its cleaning effect is significantly improved compared with the existing single adsorption and purification modified asphalts, which is of great significance for reducing energy consumption and alleviating the pressure on road service and the ecological environment. Brief Description of the Drawings

[0037] Figure 1(a) is the emission reduction effect diagram of the modified asphalt in Examples 1 to 5 during the construction period and the operation period.

[0038] Figure 1(b) is the emission reduction effect diagram of the modified asphalt in Examples 1 to 5 during thermal regeneration and re-service.

[0039] Figure 2(a) is the comparison diagram of the emission reduction effect of the modified asphalt in Example 2 and Comparative Examples 1 to 4 during the construction period.

[0040] Figure 2(b) is the comparison diagram of the emission reduction effect of the modified asphalt in Example 2 and Comparative Example 1 during the full cycle.

[0041] Figure 3 is the emission reduction effect diagram of Example 2 on the basic components of asphalt fume.

[0042] Figure 4(a) is the tail gas purification rate of Examples 1 to 5.

[0043] Figure 4(b) is the purification effect diagram of Example 2 on the basic components of the tail gas.

[0044] The following further elaborates on the specific content of the present invention in conjunction with examples. Specific Embodiments

[0045] It should be noted that all raw materials in the present invention, unless otherwise specified, are all raw materials known in the prior art. For example, SBS modified asphalt or rubber powder modified asphalt both adopt the known and commonly used SBS modified asphalt or rubber powder modified asphalt.

[0046] The number-average molecular weight of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) is 70,000, and the polymerization method is copolymerization. Among them, the mass ratio of poly(3,4-ethylenedioxythiophene) to poly(styrenesulfonic acid) is 1:2.5.

[0047] The number-average molecular weight of polydivinylbenzene is 40,000.

[0048] The pore size distribution of the adsorption base material A is in the range of 2-50 nm, and the target harmful substances adsorbed by the adsorption base material A are VOC and inorganic small molecule gases in the roadside harmful gases.

[0049] The pore size distribution of the adsorption base material B is in the range of 0.5-2.5 μm, and the target harmful substances adsorbed by the adsorption base material B are fine solid particles such as PM2.5 in the roadside harmful gases.

[0050] Following the above technical solution, the specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent transformations made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0051] Example 1:

[0052] This example provides a modified asphalt with the function of directionally adsorbing roadside harmful gases. Calculated by mass, it is made from the following raw materials: 89.5 parts of road asphalt, 4.5 parts of cleaning modifier, 2 parts of dispersant, and 4 parts of coupling agent.

[0053] This example also provides a cleaning modifier, which is made from the following raw materials: bornite powder, adsorption base material A, adsorption base material B, polydivinylbenzene, and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), and their mass ratio is 2:0.8:1.2:0.1:0.05.

[0054] The adsorption base material A is carbon black.

[0055] The adsorption base material B is fly ash.

[0056] The road asphalt is 70# base asphalt.

[0057] The dispersant is sodium dodecylbenzenesulfonate.

[0058] The coupling agent is a silane coupling agent.

[0059] The preparation method of the modified asphalt with the function of directionally adsorbing roadside harmful gases in this example is carried out according to the following steps:

[0060] Step 1, pretreatment of raw materials:

[0061] Add chalcopyrite powder to the methacryloyl chloride-deionized water solution, let it stand at room temperature, control the reaction time to be 3 h, stir it every 30 min during this period, and after the reaction is completed, filter out the powder and dry it for later use.

[0062] Place carbon black in a muffle furnace, set the temperature to 500 °C, keep the temperature for 2 h, then grind the obtained product, sieve it and place it in a cetyltrimethylammonium bromide-deionized water solution, let it stand at room temperature, control the reaction time to be 3 h, stir it every 30 min during this period, and after the reaction is completed, filter out the powder and dry it for later use.

[0063] Soak fly ash in 0.1 mol / L hydrochloric acid solution for 6 h, then use deionized water to ultrasonically clean it multiple times until the pH value of the sample is neutral, and then filter it out and dry it for use.

[0064] Step two, preparation of cleaning modifier:

[0065] Mix poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) with chalcopyrite powder in deionized water solution, use a high-speed shearer, set the shear speed to 2000 rpm, and the shear time to 30 min, then filter out the powder and dry it for later use.

[0066] Dissolve polydivinylbenzene with absolute ethanol, immerse carbon black in the polydivinylbenzene-absolute ethanol mixture for 4 h, and then place it in an oven at 60 °C for 6 h to obtain porous carbon black surface-modified with polydivinylbenzene.

[0067] Place fly ash in a planetary ball mill, use absolute ethanol as the ball milling medium, the ratio of material to liquid is 1:3, the ball milling rate is 600 rpm, and the ball milling time is 3 h. After the grinding is completed, filter out the powder and dry it for later use.

[0068] Mix carbon black, fly ash and chalcopyrite powder in deionized water solution, ultrasonically disperse for 2 h, the ultrasonic wave is 50 HZ, then dry the chalcopyrite powder / carbon black / fly ash mixture at 50 °C and sieve it for later use to prepare the cleaning modifier.

[0069] Step three, preparation of modified asphalt with the function of directionally adsorbing harmful gases in the road area:

[0070] Heat the road asphalt to 160 ± 5 °C, slowly add the cleaning modifier and silane coupling agent to the road asphalt, first use a stirrer to stir at low speed for 8 min, the shear rate is 1000 - 1200 rpm, and then use a shearer to shear at high speed for 25 min, the shear rate is 3000 - 3500 rpm, to prepare the modified asphalt with the function of directionally adsorbing harmful gases in the road area.

[0071] Example 2:

[0072] This embodiment provides a modified asphalt with the function of directionally adsorbing harmful gases in the road area. It is made from the following raw materials by mass: 88.68 parts of road asphalt, 5.32 parts of cleaning modifier, 2 parts of dispersant, and 4 parts of coupling agent.

[0073] The cleaning modifier in this embodiment is the same as that in Embodiment 1.

[0074] The selection and specifications of the raw materials in this embodiment are the same as those in Embodiment 1.

[0075] The preparation method of the modified asphalt with the function of directionally adsorbing harmful gases in the road area in this embodiment is the same as that in Embodiment 1.

[0076] Embodiment 3:

[0077] This embodiment provides a modified asphalt with the function of directionally adsorbing harmful gases in the road area. It is made from the following raw materials by mass: 87.85 parts of road asphalt, 6.15 parts of cleaning modifier, 2 parts of dispersant, and 4 parts of coupling agent.

[0078] The cleaning modifier in this embodiment is the same as that in Embodiment 1.

[0079] The selection and specifications of the raw materials in this embodiment are the same as those in Embodiment 1.

[0080] The preparation method of the modified asphalt with the function of directionally adsorbing harmful gases in the road area in this embodiment is the same as that in Embodiment 1.

[0081] Embodiment 4:

[0082] This embodiment provides a modified asphalt with the function of directionally adsorbing harmful gases in the road area. It is made from the following raw materials by mass: 87.04 parts of road asphalt, 6.96 parts of cleaning modifier, 2 parts of dispersant, and 4 parts of coupling agent.

[0083] The cleaning modifier in this embodiment is the same as that in Embodiment 1.

[0084] The selection and specifications of the raw materials in this embodiment are the same as those in Embodiment 1.

[0085] The preparation method of the modified asphalt with the function of directionally adsorbing harmful gases in the road area in this embodiment is the same as that in Embodiment 1.

[0086] Embodiment 5:

[0087] This embodiment provides a modified asphalt with the function of directionally adsorbing harmful gases in the road area. It is made from the following raw materials by mass: 86.24 parts of road asphalt, 7.76 parts of cleaning modifier, 2 parts of dispersant, and 4 parts of coupling agent.

[0088] The cleaning modifier in this example is the same as that in Example 1.

[0089] The selection and specifications of the raw materials in this example are the same as those in Example 1.

[0090] The preparation method of the modified asphalt with the function of directionally adsorbing harmful gases in road areas in this example is the same as that in Example 1.

[0091] Comparative Example 1:

[0092] This comparative example provides a modified asphalt, which is different from that in Example 2 in that 5.32 parts of separate bornite powder are used to replace 5.32 parts of the cleaning modifier in Example 2 in equal mass.

[0093] The preparation method of the modified asphalt in this comparative example is as follows: heat the road asphalt to 160 ± 5 °C, slowly add the bornite powder and silane coupling agent to the road asphalt, first stir at a low speed with a stirrer for 8 min, the shear rate is 1000 - 1200 rpm, and then shear at a high speed with a shearer for 25 min, the shear rate is 3000 - 3500 rpm, to obtain the modified asphalt with polarization effect.

[0094] Comparative Example 2:

[0095] This comparative example provides a modified asphalt, which is different from that in Example 2 in that 5.32 parts of separate carbon black are used to replace 5.32 parts of the cleaning modifier in Example 2 in equal mass.

[0096] The preparation method of the modified asphalt in this comparative example is basically the same as that in Comparative Example 1, and the only difference is that carbon black is used to completely replace bornite powder in equal mass.

[0097] Comparative Example 3:

[0098] This comparative example provides a modified asphalt, which is different from that in Example 2 in that 5.32 parts of separate fly ash are used to replace 5.32 parts of the cleaning modifier in Example 2 in equal mass.

[0099] The preparation method of the modified asphalt in this comparative example is basically the same as that in Comparative Example 1, and the only difference is that fly ash is used to completely replace bornite powder in equal mass.

[0100] Comparative Example 4:

[0101] This comparative example provides a modified asphalt, which is different from that in Example 2 in that 5.32 parts of carbon black / fly ash composite powder are used to replace 5.32 parts of the cleaning modifier in Example 2 in equal mass.

[0102] The preparation method of the carbon black / fly ash composite powder is as follows: anhydrous ethanol is used as the ball milling medium, the ratio of material to liquid is 1:3, the ball milling rate is 600 rpm, and the ball milling time is 3 h. After the grinding is completed, the fly ash is filtered out and dried for standby; anhydrous ethanol is used to dissolve polydivinylbenzene, and the carbon black is impregnated in the polydivinylbenzene-anhydrous ethanol mixture for 4 h, and then placed in an oven at 60 °C for 6 h to obtain porous carbon black modified on the surface of polydivinylbenzene; finally, the carbon black, fly ash and diatomite are mixed in deionized water solution and placed in a planetary ball mill, the ball milling rate is 200 rpm, and the ball milling time is 2 h to prepare a carbon black / fly ash / diatomite composite powder with a multi-level pore structure.

[0103] The preparation method of the modified asphalt in this comparative example is as follows: heat the road asphalt to 160 ± 5 °C, slowly add the carbon black / fly ash / diatomite composite powder and the silane coupling agent to the road asphalt, first use a stirrer to stir at a low speed for 8 min, the shear rate is 1000 - 1200 rpm, and then use a shearer to shear at a high speed for 25 min, the shear rate is 3000 - 3500 rpm, to prepare a modified asphalt with a polarization effect.

[0104] Comparative Example 5:

[0105] This comparative example provides an asphalt, namely 70 # asphalt, and a commercially available product can be used specifically.

[0106] Performance test:

[0107] First, emission reduction effect:

[0108] The flue gas emissions of the asphalt pavement include the pavement construction, operation and maintenance (hot recycling, re-service) stages. The emission reduction rates of the asphalt mixture at 170 °C and 60 °C are used to evaluate the emission reduction effects of the asphalt pavement construction stage and the operation stage respectively; in addition, the emission reduction rates of the aged modified asphalt mixture at 170 °C and 60 °C are tested to evaluate the emission reduction effect of the asphalt pavement maintenance stage.

[0109] As shown in Figure 1(a) and Figure 1(b), in Examples 1 - 5, the emission reduction rate of the asphalt pavement construction period is 48.76 - 51.54%, the emission reduction rate of the asphalt pavement operation period is 45.51 - 58.62%, the emission reduction rate of the recycled asphalt pavement construction period is 41.38 - 44.21%, and the emission reduction rate of the recycled asphalt pavement operation period is 39.21 - 42.43%. The emission reduction rates in each pollutant emission stage are all greater than 42%, showing excellent emission reduction effects, and the emission reduction rate of the self-cleaning asphalt prepared decays little with the passage of the road life cycle, indicating that the self-cleaning modified asphalt prepared by the present invention has a significant long-term emission reduction effect throughout the life cycle.

[0110] Comparing Examples 1 - 5, Example 2 has the best reduction rate of asphalt fume throughout the life cycle of asphalt pavement. Among them, the reduction rate during the construction period of asphalt pavement is 51.54%, the reduction rate during the operation period of asphalt pavement is 48.62%, the reduction rate during the construction period of recycled asphalt pavement is 44.21%, and the reduction rate during the operation period of recycled asphalt pavement is 42.43%, with the best emission reduction effect. Therefore, Example 2 with a clean modifier dosage of 7% is preferably the example with the best emission reduction effect.

[0111] As shown in Figures 2(a) and 2(b), the reduction rate of Comparative Example 1 in each pollutant emission stage decreased significantly compared to Example 2. The emission reduction effects of Comparative Examples 2 - 4 can only ensure the construction period of asphalt pavement. This is because using bornite powder as an emission reduction agent can only rely on the thermoelectric effect of bornite powder to degrade asphalt fumes. When using carbon black, fly ash, or carbon black / fly ash as emission reduction agents, saturation occurs with the progress of adsorption, and the emission reduction effect of modified asphalt during the operation period of asphalt pavement drops suddenly. Therefore, the emission reduction effects of modified asphalt prepared with single purification and adsorption modifiers are not good.

[0112] From Figure 3 it can be seen that in the construction period and operation period of the embodiments of the present invention, there is a good cleaning effect on various pollutants in asphalt fume. During the construction period, the reduction rates of CO2, CO, NO x , SO2, H2S, TVOC, PM2.5, and PM10 reach 54.28%, 54.89%, 64.89%, 63.18%, 59.01%, 70.74%, 63.58%, and 69.34%. During the operation period, the reduction rates of CO2, CO, NO x , SO2, H2S, TVOC, PM2.5, and PM10 in TBD modified asphalt reach 48.46%, 49.44%, 58.87%, 56.11%, 53.71%, 64.35%, 52.73%, and 59.71%.

[0113] First, purification effect:

[0114] 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 asphalt pavement. To determine the purification effect of the modified asphalt developed in the present invention, the exhaust gas concentration before and after the absorption and degradation of the modified asphalt mixture was measured, and the purification rate was calculated. The test results are shown in Figures 4(a) and 4(b).

[0115] As can be seen from Figures 4(a) and 4(b), the exhaust gas purification rates of each example are 44.67 - 53.08%, with excellent exhaust gas purification effects. Among them, the exhaust gas purification rate of Example 2 is the highest, at 53.08%, with the best exhaust gas purification effect. The self-cleaning modified asphalt mixture has a purification efficiency of CO and NO for vehicle exhaust at 70°Cx The purification rates of CO2 and HC are 34.31%, 61.79%, 37.87% and 44.79% respectively.

Claims

1. A cleaning modifier, characterized in that, It is made from the following raw materials: bornite powder, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), methacryloyl chloride, polydivinylbenzene, adsorption base material A, adsorption base material B; The adsorption base material A is carbon black, biochar, activated carbon, mesoporous silica or zeolite; The adsorption base material B is fly ash or diatomite.

2. The cleaning modifier according to claim 1, wherein In the cleaning modifier, the mass ratio of bornite powder, adsorption base material A, adsorption base material B, polydivinylbenzene to poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) is 2:0.8:1.2:0.1:0.

05.

3. A preparation method of the cleaning modifier as described in claim 1 or 2, the method is carried out according to the following steps: Step 1, pretreatment of raw materials: Add bornite powder to the methacryloyl chloride-deionized water solution, let it stand at room temperature, control the reaction time to be 3 h, stir every 30 min during this period, after the reaction ends, filter out the powder and dry it for later use; Place carbon black in a muffle furnace, set the temperature to 500 °C, keep the temperature for 2 h, then grind the obtained product, sieve it and place it in a cetyltrimethylammonium bromide-deionized water solution, let it stand at room temperature, control the reaction time to be 3 h, stir every 30 min during this period, after the reaction ends, filter out the powder and dry it for later use; Soak fly ash in 0.1 mol / L hydrochloric acid solution for 6 h, then use deionized water for ultrasonic cleaning multiple times until the pH value of the sample is neutral, then filter it out and dry it for use; Step 2, preparation of the cleaning modifier: Mix poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) with bornite powder in deionized water solution, use a high-speed shear instrument, set the shear speed to 2000 rpm, shear time to 30 min, then filter out the powder and dry it for later use; Dissolve polydivinylbenzene with absolute ethanol, immerse carbon black in the polydivinylbenzene-absolute ethanol mixture for 4 h, then place it in an oven at 60 °C for 6 h to obtain porous carbon black surface-modified with polydivinylbenzene; Place fly ash in a planetary ball mill, use absolute ethanol as the ball milling medium, the ratio of material to liquid is 1:3, the ball milling rate is 600 rpm, the ball milling time is 3 h, after the grinding ends, filter out the powder and dry it for later use; Mix carbon black, fly ash and bornite powder in deionized water solution, ultrasonically disperse for 2 h, the ultrasonic wave is 50 HZ, then dry the bornite powder / carbon black / fly ash mixture at 50 °C and sieve it for later use to prepare the cleaning modifier.

4. A modified asphalt, characterized in that, It is made from the following raw materials: road asphalt, cleaning modifier, dispersant and coupling agent; The cleaning modifier uses the cleaning modifier as described in claim 1 or 2.

5. The modified asphalt according to claim 4, characterized in that, Calculated by mass fraction, it is made from the following raw materials: 85.5 - 89.5 parts of road asphalt, 4.5 - 8.5 parts of cleaning modifier, 2 parts of dispersant, 4 parts of coupling agent, and the sum of the weight fractions of the raw materials is 100 parts.

6. The modified asphalt according to claim 5, characterized in that, Calculated by mass fraction, it is made from the following raw materials: 88.68 parts of road asphalt, 5.32 parts of cleaning modifier, 2 parts of dispersant, 4 parts of coupling agent.

7. The modified asphalt according to claim 4, wherein The road asphalt described above is 70# base asphalt, 90# base asphalt, SBS modified asphalt or crumb rubber modified asphalt.

8. The modified asphalt according to claim 4, characterized in that, The dispersant described above is sodium dodecylbenzenesulfonate, sodium dodecyl sulfate or polyoxyethylene octadecylamine.

9. The modified asphalt according to claim 4, characterized in that, The coupling agent described above is a silane coupling agent or a phthalate coupling agent.

10. A method for preparing the modified asphalt according to any one of claims 4 to 9, the method comprising the following steps: Heat the road asphalt to 160 ± 5 °C, slowly add the cleaning modifier and the silane coupling agent to the road asphalt, first stir at a low speed with a stirrer for 8 min, the shear rate is 1000 - 1200 rpm, and then use a shearer to shear at a high speed for 25 min, the shear rate is 3000 - 3500 rpm, to obtain the modified asphalt with the function of directionally adsorbing harmful gases in the road area.

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