Super-hydrophobic activated carbon material, preparation method and application thereof

Abstract

The application discloses a kind of super-hydrophobic activated carbon materials, preparation method and application, it is related to activated carbon production technical field, including the following mass parts of raw materials: 70-90 parts activated carbon, 5-15 parts silicon dioxide nanoparticles, 1-5 parts fluorosilane, 3-7 parts reinforcing modifier.The application adds reinforcing modifier in raw materials, dopamine will occur self-polymerization and form polydopamine in alkaline borate buffer solution, by the active functional groups such as a large number of catechol and amino contained in polydopamine, when pretreated activated carbon B is immersed in reinforcing modifier, polydopamine will be deposited on the surface of activated carbon, by active group, more binding sites are provided for subsequent modification particle A self-assembly, enhance the physical adsorption and chemical bonding effect between modification particle A and activated carbon, to enhance the practical use effect of super-hydrophobic activated carbon, and optimize production process in production process, enhance the functionality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of activated carbon production, in particular to a super-hydrophobic activated carbon material, a preparation method and application thereof. BACKGROUND

[0002] Activated carbon is a kind of microcrystalline carbon material with black appearance, developed internal pore structure, large specific surface area and strong adsorption capacity, which is made of carbon-containing materials. Due to its rich pore structure and large specific surface area, it can adsorb harmful gases in the air, remove organic matter, heavy metal ions, residual chlorine and other harmful substances in water, and thus is widely used in many fields.

[0003] However, ordinary activated carbon contains a large number of hydrophilic groups such as hydroxyl and carboxyl groups, which is easily hygroscopic when used. When the hygroscopic rate of ordinary activated carbon reaches 15%, the water adsorbed on the surface of ordinary activated carbon will form a water barrier layer, which will block the internal pore structure of ordinary activated carbon and show strong oleophobicity. At this time, organic matter will be blocked on the surface of ordinary activated carbon, forming a blocking layer that neither water nor organic matter can penetrate, and ordinary activated carbon will completely lose its adsorption capacity, showing a "high humidity poisoning" phenomenon, which has the problem of low practicality.

[0004] In view of the problems in the related art, no effective solution has been proposed so far. SUMMARY

[0005] In view of the problems in the related art, the present application proposes a super-hydrophobic activated carbon material, a preparation method and application thereof to overcome the above technical problems existing in the prior art.

[0006] To this end, the specific technical solutions adopted by the present application are as follows:

[0007] A super-hydrophobic activated carbon material, comprising the following raw materials by mass fraction: 70-90 parts of activated carbon, 5-15 parts of silicon dioxide nanoparticles, 1-5 parts of fluorosilane, and 3-7 parts of a reinforcing modifier.

[0008] The reinforcing modifier is prepared by the following steps:

[0009] Step 1, mix and dissolve borax and boric acid in deionized water, adjust the pH to 8.4-8.6 with 1M HCl to obtain a borate buffer solution;

[0010] Step 2, add dopamine hydrochloride to the borate buffer solution, ultrasonically disperse for 10 minutes, and react under light-proof conditions in stages. First, nitrogen-air mixed gas is introduced to maintain the dissolved oxygen at 3-4mg / L, and then the reaction is continued for 2 hours under magnetic stirring, and then the temperature is increased for 4 hours. The reinforcing modifier is obtained by concentrating through a 100kDa ultrafiltration membrane.

[0011] As a preferred embodiment, the mass ratio of borax, boric acid, and deionized water used in step 1 is 3.81:3.09:1000, and a magnetic stirrer is used for stirring when adjusting the pH in step 1, with a stirring speed of 200 rpm and a temperature of 24-26°C.

[0012] As a preferred embodiment, the mass-volume ratio of dopamine hydrochloride to borate buffer used in step 2 is 1.5g:1L, the ultrasonic dispersion parameters are 40kHz, the volume ratio of nitrogen-air mixed gas is 4:1, the mixed gas inlet rate is 0.5L / min, the magnetic stirring speed is 300rpm, the constant temperature reaction is divided into two stages, 25°C for 2 hours and 35°C for 4 hours, the transmembrane pressure difference for ultrafiltration operation is 1.3-1.7bar, and the tangential flow rate is 2.5-3.5m / s.

[0013] A method for preparing a super-hydrophobic activated carbon material, comprising the following preparation steps:

[0014] S1, the following raw materials are weighed by mass fraction: including 70-90 parts of activated carbon, 5-15 parts of silicon dioxide nanoparticles, 1-5 parts of fluorosilane, and 3-7 parts of strengthening modifier;

[0015] S2, the silicon dioxide nanoparticles are added to anhydrous ethanol and ultrasonically dispersed with an ultrasonic cleaning machine to form a uniform dispersion liquid. Fluorosilane is added under magnetic stirring for 4-6 hours at room temperature. The fluorosilane needs to be mixed with anhydrous ethanol and left for 30 minutes. After the reaction is completed, the modified particles are separated by a centrifuge, washed with anhydrous ethanol for 2-3 times, and then placed in an oven at 60-80°C for drying for 12-24 hours to obtain modified particles A;

[0016] S3, the activated carbon is placed in a muffle furnace and calcined at 350-400°C under argon protection for 2-4 hours. After cooling, it is soaked in a hydrochloric acid solution and stirred with a stirrer for 2-4 hours. Then it is washed with deionized water until the conductivity is <50μS / cm, filtered through a filter, and then placed in an oven at 100-120°C for drying for 12-24 hours to obtain pretreated activated carbon B;

[0017] S4, the pretreated activated carbon B is immersed in the strengthening modifier, oscillated and deposited at 40°C for 6 hours, soaked in 0.1M HNO3 for 20 minutes to remove boron residues, washed with deionized water for 2-3 times, calcined at 250°C under argon protection in a muffle furnace for 40 minutes to obtain pretreated activated carbon C;

[0018] S5, re-disperse the modified particles A in anhydrous ethanol, ultrasonic dispersion by ultrasonic cleaner, then add the pretreated activated carbon C, stir for 4-8 hours by magnetic stirrer, then vacuum soak for 2-4 hours, make the modified particles A self-assemble on the surface and pore of the pretreated activated carbon C by physical adsorption and chemical bonding, separate the activated carbon loaded with particles by centrifuge, wash for 2-3 times by anhydrous ethanol, then dry in the oven at 60-80℃ for 12-24 hours, then put into the muffle furnace for heat treatment under argon protection at 180-200℃ for 1.5 hours, obtain the super-hydrophobic activated carbon.

[0019] As a preferred embodiment, the S5 includes a pretreated activated carbon C assembly time determination step:

[0020] By using the method of overall experimental design, different values of stirring time and soaking time are combined to form multiple experimental conditions, wherein the values of stirring time are 6, 6.5, 7, 7.5, 8, and the values of soaking time are 2, 2.5, 3, 3.5, 4, obtaining 25 experimental combinations.

[0021] Re-disperse the modified particles A in anhydrous ethanol, ultrasonic dispersion by ultrasonic cleaner, add the pretreated activated carbon C, magnetic stirring for the set stirring time t1, then vacuum soak for the set soaking time t2, obtain the final super-hydrophobic activated carbon sample according to step S5, measure the contact angle y of the sample by contact angle measuring instrument, measure the adsorption amount z of the sample to specific substances by adsorption experiment, construct the linear models y = at1 + bt1 + c, z = dt1 + et1 + f.

[0022] Use the least square method to solve the parameters a, b, c, d, e, f in the above linear models, based on the water contact angle and adsorption amount under different order production requirements, obtain two groups of stirring time and two groups of soaking time by linear models, select the maximum value as the current order stirring time and soaking time by max function in the stirring time and soaking time.

[0023] As a preferred embodiment, the ultrasonic cleaning parameters in S2 are 40 kHz, the time is 30 minutes, the stirring speed of the magnetic stirrer is 400 rpm, the centrifuge of the centrifuge is gradient centrifugation, first remove large particles at 2000 rpm, then collect target particles at 4000 rpm.

[0024] As a preferred embodiment, the heating rate of the muffle furnace in S3, S4, S5 is 5℃ / min, the concentration of hydrochloric acid solution in S3 is 5%-10%, the solid-liquid ratio of activated carbon and hydrochloric acid is 1:10, and the stirring speed of the stirrer is 250 rpm.

[0025] As a preferred embodiment, the ultrasonic cleaning parameters in S5 are 40 kHz, 35 minutes, the stirring speed of the magnetic stirrer is 250 rpm, and the vacuum degree of the vacuum immersion is-0.09 MPa.

[0026] As a preferred embodiment, the fluorosilane is heptadecafluorodecyltrimethoxysilane.

[0027] The application of the super-hydrophobic activated carbon material is an adsorption material.

[0028] The beneficial effects of the present application are:

[0029] 1. By adding a strengthening modifier to the raw material, dopamine will undergo a self-polymerization reaction to form polydopamine in an alkaline borate buffer solution. The polydopamine contains a large number of active functional groups such as catechol and amino groups. When the pretreated activated carbon B is immersed in the strengthening modifier, the polydopamine will deposit on the surface of the activated carbon. The active groups provide more binding sites for the self-assembly of the subsequent modified particle A, enhancing the physical adsorption and chemical bonding between the modified particle A and the activated carbon, thereby enhancing the actual use effect of the super-hydrophobic activated carbon.

[0030] 2. The polydopamine forms hydrogen bonds and covalent bonds with the hydroxyl groups on the surface of the activated carbon through phenolic hydroxyl groups and amino groups, and simultaneously bonds with the silicon hydroxyl groups of the fluorosilane-modified silica nanoparticles, forming a three-dimensional network cross-linked structure to improve the water contact angle stability.

[0031] 3. The polydopamine deposited on the surface of the activated carbon may form a small protrusion and a granular structure, further increasing the roughness of the activated carbon surface, which is conducive to the synergistic effect of the silica nanoparticles and the fluorosilane, and can better form an air layer, thereby improving the contact angle of the super-hydrophobic activated carbon and enhancing its super-hydrophobic performance, thereby enhancing the functionality.

[0032] 4. The magnetic stirrer is used to realize the physical adsorption of the modified particle A, and then the vacuum immersion is used to strengthen the pore penetration. By constructing a relationship model of the water contact angle, the adsorption capacity, the stirring time, and the immersion time, and combining the actual order requirements, the stirring time and the immersion time in the actual production process can be flexibly set to optimize the actual production process. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0034] Figure 1 is a flow chart of a method for preparing a super-hydrophobic activated carbon material according to an embodiment of the present application;

[0035] Figure 2 is a graph of static water contact angle test results for a super-hydrophobic activated carbon material according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] To further illustrate the embodiments, the present application provides accompanying drawings, which are part of the disclosure and mainly serve to illustrate the embodiments. The working principles of the embodiments can be explained in conjunction with the relevant descriptions in the specification. Those skilled in the art should be able to understand other possible implementations and advantages of the present application by referring to these contents. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0037] According to embodiments of the present application, a super-hydrophobic activated carbon material, a preparation method thereof, and applications thereof are provided.

[0038] The present application will be further described in conjunction with the accompanying drawings and specific embodiments:

[0039] Embodiment 1:

[0040] According to an embodiment of the present application, a high-strength corrosion-resistant inflatable boat material includes the following raw materials by mass fraction: 70-90 parts of activated carbon, 5-15 parts of silicon dioxide nanoparticles, 1-5 parts of fluorosilane, and 3-7 parts of a strengthening modifier.

[0041] The strengthening modifier is prepared by the following steps:

[0042] Step 1, mix and dissolve borax and boric acid in deionized water, adjust the pH to 8.4-8.6 with 1M HCl to obtain a borate buffer solution;

[0043] Step 2, add dopamine hydrochloride to the borate buffer solution, ultrasonically disperse for 10 minutes, and react under constant temperature in the dark. First, introduce nitrogen-air mixed gas to maintain the dissolved oxygen at 3-4 mg / L, then continue to react for 4 hours after magnetic stirring reaction for 2 hours, and then concentrate to obtain the strengthening modifier through a 100 kDa ultrafiltration membrane;

[0044] A method for preparing a super-hydrophobic activated carbon material includes the following preparation steps:

[0045] S1, the following raw materials are weighed by mass fraction: 70-90 parts of activated carbon, 5-15 parts of silicon dioxide nanoparticles, 1-5 parts of fluorosilane, and 3-7 parts of a strengthening modifier;

[0046] S2, the silica nanoparticles are added to anhydrous ethanol, ultrasonic dispersion is performed by using an ultrasonic cleaner to form a uniformly dispersed solution, fluorosilane is added under stirring of a magnetic stirrer, and reaction is performed at room temperature for 4-6 hours, wherein the fluorosilane needs to be mixed with anhydrous ethanol and left to stand for 30 minutes, the modified particles are separated by using a centrifuge after the reaction is completed, the modified particles are washed 2-3 times by using anhydrous ethanol, and then are placed in an oven for drying at 60-80 °C for 12-24 hours to obtain modified particles A;

[0047] S3, the activated carbon is placed in a muffle furnace, calcination is performed at 350-400 °C under argon protection for 2-4 hours, after cooling, the activated carbon is soaked in a hydrochloric acid solution, stirring is performed by using a stirrer for 2-4 hours, then washing is performed by using deionized water until the conductivity is less than 50 μS / cm, the activated carbon is filtered by using a filter, and then is placed in an oven for drying at 100-120 °C for 12-24 hours to obtain pretreated activated carbon B;

[0048] S4, the pretreated activated carbon B is immersed in a reinforced modifier, deposition is performed by oscillation at 40 °C for 6 hours, boron residues are removed by immersing in 0.1M HNO3 for 20 minutes, washing is performed 2-3 times by using deionized water, calcination is performed by using a muffle furnace at 250 °C under argon protection for 40 minutes to obtain pretreated activated carbon C;

[0049] S5, the modified particles A are redispersed in anhydrous ethanol, ultrasonic dispersion is performed by using an ultrasonic cleaner, then the pretreated activated carbon C is added, stirring is performed by using a magnetic stirrer for 4-8 hours, vacuum impregnation is performed for 2-4 hours, the modified particles A are self-assembled on the surface and pores of the pretreated activated carbon C by physical adsorption and chemical bonding, the loaded particle activated carbon is separated by using a centrifuge, washing is performed 2-3 times by using anhydrous ethanol, drying is performed in an oven at 60-80 °C for 12-24 hours, then heat treatment is performed by using a muffle furnace at 180-200 °C under argon protection for 1.5 hours to obtain super-hydrophobic activated carbon;

[0050] The assembly time determination step of the pretreated activated carbon C in S5 is as follows:

[0051] The full experimental design method is adopted, different values of the stirring time and the impregnation time are combined to form multiple experimental conditions, wherein the values of the stirring time are 6, 6.5, 7, 7.5 and 8, and the values of the impregnation time are 2, 2.5, 3, 3.5 and 4, and 25 kinds of experimental combinations are obtained;

[0052] The modified particles A are redispersed in anhydrous ethanol, ultrasonic dispersion is performed by using an ultrasonic cleaner, the pretreated activated carbon C is added, magnetic stirring is performed according to the set stirring time t1, vacuum impregnation is performed according to the set impregnation time t2, the final super-hydrophobic activated carbon sample is obtained according to step S5, the contact angle y of the sample is measured by using a contact angle measuring instrument, the adsorption amount z of the sample to a specific substance is measured by using an adsorption experiment, and a linear model y=at1+bt1+c, z=dt1+et1+f is constructed.

[0053] The parameters a, b, c, d, e, f in the above linear model are solved by using the least square method, and two groups of stirring time and two groups of immersion time are obtained by the linear model based on the water contact angle and the adsorption amount under different order production requirements, and the maximum value is selected as the current order stirring time and immersion time by the max function in the stirring time and the immersion time.

[0054] The fluorosilane used is heptadecafluorodecyltrimethoxysilane.

[0055] Example 2:

[0056] A super-hydrophobic activated carbon, the specific process and preparation process are as follows:

[0057] S1, the following raw materials are weighed by mass fraction: including 70-90 parts of activated carbon, 5-15 parts of silicon dioxide nanoparticles, 1-5 parts of fluorosilane, 3-7 parts of strengthening modifier;

[0058] S2, 5 parts of silicon dioxide nanoparticles are added to anhydrous ethanol, and an ultrasonic cleaning machine is used to disperse for 30 minutes at 40 kHz to form a uniform dispersion liquid, 1 part of fluorosilane is added under the stirring of a magnetic stirrer at 400 rpm, and the reaction is carried out at room temperature for 4 hours, wherein the fluorosilane needs to be mixed with anhydrous ethanol and left for 30 minutes, after the reaction, a centrifuge is used to remove large particles at 2000 rpm first, and then collect the modified particles at 4000 rpm, after washing with anhydrous ethanol for 3 times, put into an oven and dry at 60-80°C for 18 hours, to obtain modified particles A;

[0059] S3, 70 parts of activated carbon are placed in a muffle furnace and calcined at 350-400°C under argon protection for 3 hours, after cooling, soaked in 5% hydrochloric acid solution, stirred with a stirrer at 250 rpm for 4 hours, then washed with deionized water until the conductivity is <50 μS / cm, filtered through a filter, and then placed in an oven and dried at 100-120°C for 18 hours to obtain pretreated activated carbon B;

[0060] S4, the pretreated activated carbon B is immersed in 3 parts of the strengthening modifier, oscillated and deposited at 40°C for 6 hours, soaked in 0.1M HNO3 for 20 minutes to remove boron residues, washed with deionized water for 3 times, calcined at 250°C under argon protection in a muffle furnace for 40 minutes, to obtain pretreated activated carbon C;

[0061] S5, the modified particles A are re-dispersed in anhydrous ethanol, dispersed by an ultrasonic cleaning machine at 40 kHz, then the pretreated activated carbon C is added, stirred by a magnetic stirrer at 250 rpm for 6 hours, vacuum impregnated for 3 hours, so that the modified particles A are self-assembled on the surface and pores of the pretreated activated carbon C by physical adsorption and chemical bonding, the activated carbon loaded with the particles is separated by a centrifuge, washed by anhydrous ethanol for 3 times, dried in an oven at 60-80°C for 18 hours, then placed in a muffle furnace for heat treatment at 180°C under argon protection for 1.5 hours, to obtain super-hydrophobic activated carbon.

[0062] wherein the fluorosilane used is heptadecafluorodecyltrimethoxysilane.

[0063] Example 3:

[0064] S1, the following raw materials are weighed according to the mass fraction: 90 parts of activated carbon, 15 parts of silica nanoparticles, 5 parts of fluorosilane, and 7 parts of strengthening modifier.

[0065] S2, 15 parts of silica nanoparticles are added to anhydrous ethanol, dispersed by an ultrasonic cleaning machine at 40 kHz for 30 minutes to form a uniform dispersion, 5 parts of fluorosilane is added under stirring by a magnetic stirrer at 400 rpm, and the reaction is carried out at room temperature for 4 hours, wherein the fluorosilane needs to be mixed with anhydrous ethanol and left for 30 minutes, then the reaction is completed, large particles are removed by a centrifuge at 2000 rpm, and the modified particles are collected by a centrifuge at 4000 rpm, washed by anhydrous ethanol for 3 times, and dried in an oven at 60-80°C for 18 hours to obtain modified particles A;

[0066] S3, 90 parts of activated carbon are placed in a muffle furnace and calcined at 350-400°C under argon protection for 3 hours, then cooled, soaked in a 5% hydrochloric acid solution, stirred by a stirrer at 250 rpm for 4 hours, then washed by deionized water until the conductivity is <50 μS / cm, filtered by a filter, and dried in an oven at 100-120°C for 18 hours to obtain pretreated activated carbon B;

[0067] S4, the pretreated activated carbon B is immersed in 7 parts of the strengthening modifier, oscillated at 40°C for 6 hours, soaked in 0.1M HNO3 for 20 minutes to remove boron residues, washed by deionized water for 3 times, calcined in a muffle furnace at 250°C under argon protection for 40 minutes to obtain pretreated activated carbon C;

[0068] S5, the modified particles A were re-dispersed in anhydrous ethanol, dispersed by an ultrasonic cleaning machine at 40 kHz, then the pretreated activated carbon C was added, and the mixture was stirred by a magnetic stirrer at 250 rpm for 6 hours, followed by vacuum impregnation for 3 hours, so that the modified particles A were self-assembled onto the surface and pores of the pretreated activated carbon C by physical adsorption and chemical bonding, the activated carbon loaded with the particles was separated by a centrifuge, washed with anhydrous ethanol for 3 times, dried in an oven at 60-80°C for 18 hours, and then placed in a muffle furnace for heat treatment at 180°C under argon protection for 1.5 hours, to obtain the super-hydrophobic activated carbon.

[0069] wherein the fluorosilane used is heptadecafluorodecyltrimethoxysilane.

[0070] Comparative Example 1:

[0071] The step S4 in Example 2 was removed, and the pretreated activated carbon B was used to assemble the modified particles A, and the other raw materials were unchanged, to obtain the super-hydrophobic activated carbon.

[0072] Comparative Example 2:

[0073] The step S4 in Example 3 was removed, and the pretreated activated carbon B was used to assemble the modified particles A, and the other raw materials were unchanged, to obtain the super-hydrophobic activated carbon.

[0074] Experimental Example 1:

[0075] The super-hydrophobic activated carbons obtained in Examples 2, 3 and Comparative Examples 1 and 2 were subjected to performance tests, including static water contact angle test, dynamic rolling angle test, moisture absorption rate test, BET specific surface area test, and toluene adsorption capacity, and the test results are shown in Table 1.

[0076] Table 1: Test Table of Super-hydrophobic Activated Carbon

[0077] Test item Example 2 Example 3 Comparative Example 1 Comparative Example 2 Static water contact angle (°) 151 154 128 130 Dynamic roll-off angle (°) 5 4 25 23 Moisture absorption rate 7.2％ 6.8％ 14.5％ 15.1％ BET specific surface area retention rate 93.7％ 94.2％ 83.4％ 82.1％ Toluene adsorption capacity 298 315 210 225

[0078] wherein the static water contact angle was measured according to the standard GB / T 30693-2014, the sample was pressed into a 10x10mm flat surface, a contact angle measuring instrument was used, 5μL of ultrapure water was added dropwise, the contact angle was calculated by Young-Laplace equation, and the average value of 5 points was taken as the static water contact angle; for the rolling angle, the sample table was slowly tilted until the water droplet began to roll, and the inclination angle of the sample table at this time was recorded, which was the rolling angle, each sample was measured 5 times, and the average value was taken as the dynamic rolling angle;

[0079] It can be seen that the hydrophobicity of the super-hydrophobic activated carbon is further improved by strengthening the interface bonding of the modifier and reducing defects.

[0080] The moisture absorption rate test is to respectively take the dry sample mass m0 in examples 2, 3 and comparative examples 1 and 2, place it in a constant temperature and humidity box, and take out and weigh the wet weight m1 after 48 hours at a temperature of 25 DEG C and a humidity of 90% RH, and calculate the moisture absorption rate

[0081] The BET specific surface area retention rate test is to respectively vacuum degas the samples in examples 2, 3 and comparative examples 1 and 2 at 150 DEG C for 6 hours, and calculate the specific surface area by the BET model using nitrogen adsorption method;

[0082] The toluene adsorption capacity test is to respectively put the samples in examples 2, 3 and comparative examples 1 and 2 into a closed cabin and introduce toluene vapor with a concentration of 500 ppm and a humidity of 80% RH, so that the samples in examples 2, 3 and comparative examples 1 and 2 are saturated, and the unit mass adsorption capacity is calculated.

[0083] It can be seen that the reinforcing modifier significantly improves the hydrophobic durability and moisture adsorption resistance of the super-hydrophobic activated carbon through chemical anchoring and pore protection, and argon protection calcination forms a conductive network to enhance the stability of the material. In comparative examples 1 and 2, the unsealed -OH groups cause the moisture absorption of the pores to be blocked, resulting in a decrease of 30-40% in the adsorption capacity.

[0084] In summary, the present application adds a reinforcing modifier to the raw material. Dopamine will undergo a self-polymerization reaction to form polydopamine in an alkaline borate buffer. The polydopamine contains a large number of active functional groups such as catechol and amino groups. When the pretreated activated carbon B is immersed in the reinforcing modifier, the polydopamine will deposit on the surface of the activated carbon. The active groups provide more binding sites for the self-assembly of the modified particles A, enhancing the physical adsorption and chemical bonding between the modified particles A and the activated carbon, to enhance the actual use effect of the super-hydrophobic activated carbon.

[0085] The modified particles A are physically adsorbed by magnetic stirring, and the pore penetration is strengthened by vacuum immersion. By constructing a relationship model of water contact angle, adsorption capacity, stirring time and immersion time, the stirring time and immersion time in the actual production process can be flexibly set to optimize the actual production process.

[0086] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A superhydrophobic activated carbon material, characterized in that, The raw materials include the following parts by weight: 70-90 parts activated carbon, 5-15 parts silica nanoparticles, 1-5 parts fluorosilane, and 3-7 parts reinforcing modifier. The preparation method of this superhydrophobic activated carbon material is as follows: S1. Weigh the following raw materials by mass: including 70-90 parts activated carbon, 5-15 parts silica nanoparticles, 1-5 parts fluorosilane, and 3-7 parts reinforcing modifier. The reinforcing modifier is prepared by the following steps: Step 1: Dissolve borax and boric acid in deionized water, and adjust the pH to 8.4-8.6 with 1M HCl to obtain borate buffer solution; Step 2: Add dopamine hydrochloride to borate buffer, sonicate for 10 minutes, and react in stages at a constant temperature under light-protected conditions. First, introduce nitrogen-air mixture to maintain dissolved oxygen at 3-4 mg / L. After stirring magnetically for 2 hours, raise the temperature and continue the reaction for 4 hours. Then, concentrate the mixture through a 100 kDa ultrafiltration membrane to obtain the enhanced modifier. S2. Add silica nanoparticles to anhydrous ethanol and ultrasonically disperse them using an ultrasonic cleaner to form a uniform dispersion. Add fluorosilane while stirring with a magnetic stirrer and react at room temperature for 4-6 hours. The fluorosilane needs to be mixed with anhydrous ethanol and allowed to stand for 30 minutes beforehand. After the reaction is complete, separate the modified particles using a centrifuge, wash them 2-3 times with anhydrous ethanol, and then dry them in an oven at 60-80℃ for 12-24 hours to obtain modified particles A. S3. Place the activated carbon in a muffle furnace and calcine it under argon protection at 350-400℃ for 2-4 hours. After cooling, soak it in hydrochloric acid solution and stir it with a stirrer for 2-4 hours. Then wash it with deionized water until the conductivity is <50μS / cm. After filtering it through a filter, dry it in an oven at 100-120℃ for 12-24 hours to obtain pretreated activated carbon B. S4. Immerse pretreated activated carbon B in a strengthening modifier, shake and deposit at 40°C for 6 hours, soak in 0.1M HNO3 for 20 minutes to remove boron residue, wash with deionized water 2-3 times, and calcine in a muffle furnace at 250°C under argon protection for 40 minutes to obtain pretreated activated carbon C. S5. The modified particles A are redispersed in anhydrous ethanol and ultrasonically dispersed using an ultrasonic cleaner. Then, pretreated activated carbon C is added and stirred with a magnetic stirrer for 4-8 hours. After vacuum impregnation for 2-4 hours, the modified particles A are self-assembled into the surface and pores of the pretreated activated carbon C through physical adsorption and chemical bonding. The activated carbon loaded with particles is separated by centrifugation, washed 2-3 times with anhydrous ethanol, and dried in an oven at 60-80℃ for 12-24 hours. Then, it is heat-treated in a muffle furnace at 180-200℃ under argon protection for 1.5 hours to obtain superhydrophobic activated carbon.

2. The superhydrophobic activated carbon material according to claim 1, characterized in that, The mass ratio of borax, boric acid, and deionized water used in step 1 is 3.81:3.09:1000. When adjusting the pH in step 1, a magnetic stirrer is used for stirring at a speed of 200 rpm and a temperature of 24-26℃.

3. The superhydrophobic activated carbon material according to claim 1, characterized in that, In step 2, the mass-to-volume ratio of dopamine hydrochloride to borate buffer was 1.5 g: 1 L, the ultrasonic dispersion parameter was 40 kHz, the volume ratio of nitrogen-air mixture was 4:1, the gas flow rate was 0.5 L / min, the magnetic stirring speed was 300 rpm, the staged isothermal reaction was carried out at 25 °C for the first 2 hours and 35 °C for the next 4 hours, the transmembrane pressure difference for ultrafiltration was 1.3-1.7 bar, and the tangential flow rate was 2.5-3.5 m / s.

4. The superhydrophobic activated carbon material according to claim 1, characterized in that, S5 includes a step for determining the assembly time of pretreated activated carbon C: Using a comprehensive experimental design approach, different values ​​of stirring time and immersion time were combined to form multiple experimental conditions. The stirring time was 6 hours, 6.5 hours, 7 hours, 7.5 hours, and 8 hours, and the immersion time was 2 hours, 2.5 hours, 3 hours, 3.5 hours, and 4 hours, resulting in 25 experimental combinations. Modified particles A were redispersed in anhydrous ethanol and ultrasonically dispersed using an ultrasonic cleaner. Pretreated activated carbon C was then added, and the mixture was stirred for the set time. Perform magnetic stirring, then proceed with the set soaking time. Vacuum impregnation was performed, and the final superhydrophobic activated carbon sample was obtained according to step S5. The contact angle of the sample was measured using a contact angle meter. The amount of a sample adsorbed by a specific substance is measured through adsorption experiments. Construct a linear model , ; The parameters in the above linear model are solved using the least squares method. Based on the water contact angle and adsorption amount under different order production requirements, two sets of stirring time and two sets of immersion time are obtained through a linear model. The maximum value of stirring time and immersion time is selected as the stirring time and immersion time of the current order through the max function.

5. The superhydrophobic activated carbon material according to claim 1, characterized in that, In S2, the ultrasonic cleaning parameters are 40 kHz and 30 minutes. The stirring speed of the magnetic stirrer is 400 rpm. The centrifugation is gradient centrifugation, first removing large particles at 2000 rpm and then collecting target particles at 4000 rpm.

6. The superhydrophobic activated carbon material according to claim 1, characterized in that, In S3, S4, and S5, the muffle furnace heating rate is 5°C / minute, the hydrochloric acid solution concentration in S3 is 5%-10%, the solid-liquid ratio of activated carbon to hydrochloric acid is 1:10, and the stirring speed of the stirrer is 250 rpm.

7. The superhydrophobic activated carbon material according to claim 1, characterized in that, In S5, the ultrasonic cleaning parameters are 40kHz, the time is 35 minutes, the magnetic stirrer speed is 250rpm, and the vacuum degree of vacuum impregnation is -0.09 MPa.

8. The superhydrophobic activated carbon material according to claim 1, characterized in that, The fluorosilane is heptadecafluorodecyltrimethoxysilane.

9. An application of the superhydrophobic activated carbon material according to any one of claims 1-8, characterized in that, The superhydrophobic activated carbon material is used as an adsorption material.

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