Super-hydrophobic activated carbon material as well as preparation method and application thereof

Abstract

The invention discloses a super-hydrophobic activated carbon material, a preparation method and application thereof, and relates to the technical field of activated carbon production, the super-hydrophobic activated carbon material comprises the following raw materials by mass: 70-90 parts of activated carbon, 5-15 parts of silica nanoparticles, 1-5 parts of fluorosilane, and 3-7 parts of a reinforcing modifier. According to the invention, the reinforced modifier is added into the raw materials, dopamine is subjected to self-polymerization reaction in an alkaline borate buffer solution to form polydopamine, and the polydopamine contains a large amount of catechol, amino and other active functional groups, so that when the pretreated activated carbon B is immersed into the reinforced modifier, the polydopamine is deposited on the surface of the activated carbon, and the activated carbon B is subjected to self-polymerization reaction to form the modified activated carbon. More binding sites are provided for the self-assembly of the modified particles A through the active groups, the physical adsorption and chemical bonding effects between the modified particles A and the activated carbon are enhanced, so that the actual use effect of the super-hydrophobic activated carbon is enhanced, the production process is optimized in the production process, and the functionality is enhanced.

Description

Technical Field

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

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

[0003] However, ordinary activated carbon contains a large number of hydrophilic groups such as hydroxyl and carboxyl groups, and is extremely easy to absorb moisture during use. When the moisture absorption 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 extremely 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. Ordinary activated carbon will completely lose its adsorption capacity, showing the phenomenon of "high humidity poisoning", and has the problem of low practicality.

[0004] Currently, no effective solutions have been proposed for the problems in related technologies. Summary of the Invention

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

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

[0007] A super-hydrophobic activated carbon material comprises the following raw materials in parts by weight: 70-90 parts activated carbon, 5-15 parts silicon dioxide nanoparticles, 1-5 parts fluorosilane, and 3-7 parts strengthening modifier;

[0008] Wherein, the strengthening modifier is prepared by the following steps:

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

[0010] Step 2: Add dopamine hydrochloride to borate buffer, ultrasonically disperse for 10 minutes, and react in stages at a constant temperature under light-proof conditions. First, introduce a nitrogen-air mixture to maintain the dissolved oxygen at 3-4 mg / L. After magnetic stirring for 2 hours, increase the temperature and continue the reaction for 4 hours. Concentrate through a 100 kDa ultrafiltration membrane to obtain an enhanced modifier.

[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. When adjusting the pH in step 1, a magnetic stirrer is used for stirring, the stirring speed is 200 rpm, and the temperature is 24-26°C.

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

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

[0014] S1. Weigh the following raw materials by mass: 70-90 parts of activated carbon, 5-15 parts of silica nanoparticles, 1-5 parts of fluorosilane, and 3-7 parts of a strengthening modifier;

[0015] 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. After the reaction is completed, the modified particles are separated using a centrifuge, washed with anhydrous ethanol 2-3 times, and then dried in an oven at 60-80° C. for 12-24 hours to obtain modified particles A.

[0016] S3. calcining the activated carbon in a muffle furnace at 350-400° C. under argon protection for 2-4 hours. After cooling, immersing the activated carbon in a hydrochloric acid solution and stirring with a stirrer for 2-4 hours, then washing with deionized water until the conductivity is less than 50 μS / cm, filtering the solution through a filter, and drying the solution in an oven at 100-120° C. for 12-24 hours to obtain pretreated activated carbon B.

[0017] S4, immersing the pretreated activated carbon B in the strengthening modifier, shaking and depositing at 40 ° C for 6 hours, soaking in 0.1M HNO3 for 20 minutes to remove the boron residue, washing with deionized water 2-3 times, and calcining in a muffle furnace at 250 ° C for 40 minutes under argon protection to obtain pretreated activated carbon C;

[0018] S5. Re-disperse the modified particles A in anhydrous ethanol, ultrasonically disperse them using an ultrasonic cleaner, then add pretreated activated carbon C, stir with a magnetic stirrer for 4-8 hours, and then vacuum impregnate for 2-4 hours, so that the modified particles A are self-assembled onto the surface and pores of the pretreated activated carbon C through physical adsorption and chemical bonding. Use a centrifuge to separate the particle-loaded activated carbon, wash it with anhydrous ethanol 2-3 times, and dry it in an oven at 60-80°C for 12-24 hours. Then, place it in a muffle furnace and heat-treat it at 180-200°C under argon protection for 1.5 hours to obtain superhydrophobic activated carbon.

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

[0020] A comprehensive experimental design method was used to combine different values ​​of stirring time and immersion time to form multiple experimental conditions, among which the stirring time values ​​were 6, 6.5, 7, 7.5, and 8, and the immersion time values ​​were 2, 2.5, 3, 3.5, and 4, resulting in 25 experimental combinations;

[0021] The modified particles A are redispersed in anhydrous ethanol, ultrasonically dispersed using an ultrasonic cleaner, pretreated activated carbon C is added, magnetic stirring is performed according to a set stirring time t1, and vacuum impregnation is performed according to a set impregnation time t2. The final superhydrophobic activated carbon sample is obtained according to step S5, the contact angle y of the sample is measured using a contact angle meter, and the adsorption amount z of the sample on a specific substance is measured through an adsorption experiment, and a linear model y = at1 + bt1 + c, z = dt1 + et1 + f is constructed;

[0022] The least squares method is used to solve the parameters a, b, c, d, e, and f in the above linear model. Based on the water contact angle and adsorption amount under different order production requirements, two sets of stirring times and two sets of immersion times are obtained through the linear model. The maximum value of the stirring time and immersion time is selected as the stirring time and immersion time of the current order through the max function.

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

[0024] As a preferred embodiment, the heating rate of the muffle furnace in S3, S4 and S5 is 5°C / min, the concentration of the hydrochloric acid solution 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 250rpm.

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

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

[0027] The invention discloses an application of a super-hydrophobic activated carbon material, wherein the application of the super-hydrophobic activated carbon material is an adsorption material.

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

[0029] 1. The present invention adds a strengthening modifier to the raw materials, and dopamine undergoes a self-polymerization reaction in an alkaline borate buffer to form polydopamine. Due to the large number of active functional groups such as catechol and amino groups contained in polydopamine, when the pretreated activated carbon B is immersed in the strengthening modifier, polydopamine will be deposited on the surface of the activated carbon. The active groups provide more binding sites for the subsequent self-assembly of the modified particles A, thereby enhancing the physical adsorption and chemical bonding between the modified particles A and the activated carbon, thereby enhancing the actual use effect of the superhydrophobic activated carbon.

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

[0031] 3. The present invention may form tiny protrusions and granular structures on the surface of activated carbon by depositing polydopamine, further increasing the roughness of the activated carbon surface, which is conducive to the synergistic effect of silica nanoparticles and fluorosilane, and can better form an air layer, thereby increasing the contact angle of superhydrophobic activated carbon, enhancing its superhydrophobic properties, and enhancing functionality;

[0032] 4. The present invention achieves physical adsorption of modified particles A by stirring with a magnetic stirrer, and then strengthens pore penetration through vacuum impregnation. By constructing a relationship model between water contact angle, adsorption amount, stirring time and impregnation time, and combining actual order requirements, the stirring time and impregnation time in the actual production process are flexibly set to optimize the actual production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[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 invention;

[0035] Figure 2 This is a static water contact angle test result diagram of a super-hydrophobic activated carbon material according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention. They are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. By referring to these contents, ordinary technicians in this field should be able to understand other possible implementation methods and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

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

[0038] The present invention will now be further described with reference to the accompanying drawings and specific embodiments:

[0039] Example 1:

[0040] A high-strength, corrosion-resistant inflatable boat material according to an embodiment of the present invention includes the following raw materials in parts by weight: 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: Dissolve borax and boric acid in deionized water, and adjust the pH to 8.4-8.6 with 1M HCl to obtain a borate buffer solution.

[0043] Step 2: dopamine hydrochloride was added to a borate buffer solution and ultrasonically dispersed for 10 minutes. The reaction was carried out in stages at a constant temperature under light-shielding conditions. A nitrogen-air mixture was first introduced to maintain the dissolved oxygen at 3-4 mg / L. The reaction was carried out under magnetic stirring for 2 hours, and then the temperature was raised and the reaction was continued for 4 hours. The enhanced modifier was then concentrated through a 100 kDa ultrafiltration membrane.

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

[0045] S1. Weigh the following raw materials by mass: 70-90 parts of activated carbon, 5-15 parts of silica nanoparticles, 1-5 parts of fluorosilane, and 3-7 parts of a strengthening modifier;

[0046] 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. After the reaction is completed, the modified particles are separated using a centrifuge, washed with anhydrous ethanol 2-3 times, and then dried in an oven at 60-80° C. for 12-24 hours to obtain modified particles A.

[0047] S3. calcining the activated carbon in a muffle furnace at 350-400° C. under argon protection for 2-4 hours. After cooling, immersing the activated carbon in a hydrochloric acid solution and stirring with a stirrer for 2-4 hours, then washing with deionized water until the conductivity is less than 50 μS / cm, filtering the solution through a filter, and drying the solution in an oven at 100-120° C. for 12-24 hours to obtain pretreated activated carbon B.

[0048] S4, immersing the pretreated activated carbon B in the strengthening modifier, shaking and depositing at 40 ° C for 6 hours, soaking in 0.1M HNO3 for 20 minutes to remove the boron residue, washing with deionized water 2-3 times, and calcining in a muffle furnace at 250 ° C for 40 minutes under argon protection to obtain pretreated activated carbon C;

[0049] S5. Re-dispersing the modified particles A in anhydrous ethanol, ultrasonically dispersing them using an ultrasonic cleaner, then adding pretreated activated carbon C, stirring with a magnetic stirrer for 4-8 hours, and then vacuum impregnating for 2-4 hours, so that the modified particles A self-assemble onto the surface and pores of the pretreated activated carbon C through physical adsorption and chemical bonding. The particle-loaded activated carbon is separated by a centrifuge, washed 2-3 times with anhydrous ethanol, and then dried in an oven at 60-80° C. for 12-24 hours. Then, the mixture is placed in a muffle furnace and heat-treated under argon protection at 180-200° C. for 1.5 hours to obtain superhydrophobic activated carbon.

[0050] S5 includes the step of determining the assembly time of the pretreated activated carbon C:

[0051] A comprehensive experimental design method was used to combine different values ​​of stirring time and immersion time to form multiple experimental conditions, among which the stirring time values ​​were 6, 6.5, 7, 7.5, and 8, and the immersion time values ​​were 2, 2.5, 3, 3.5, and 4, resulting in 25 experimental combinations;

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

[0053] The least squares method is used to solve the parameters a, b, c, d, e, and f in the above linear model. Based on the water contact angle and adsorption amount under different order production requirements, two sets of stirring times and two sets of immersion times are obtained through the linear model. The maximum value of the stirring time and immersion time is selected as the stirring time and immersion time of the current order through the max function.

[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. Weigh the following raw materials by mass: 70-90 parts of activated carbon, 5-15 parts of silica nanoparticles, 1-5 parts of fluorosilane, and 3-7 parts of a strengthening modifier;

[0058] S2. Add 5 parts of silica nanoparticles to anhydrous ethanol and ultrasonically disperse them at 40 kHz for 30 minutes using an ultrasonic cleaner to form a uniform dispersion. Add 1 part of fluorosilane while stirring with a magnetic stirrer at 400 rpm, and react at room temperature for 4 hours. The fluorosilane needs to be mixed with anhydrous ethanol and allowed to stand for 30 minutes. After the reaction, use a centrifuge at 2000 rpm to remove large particles, then collect the modified particles at 4000 rpm, wash them with anhydrous ethanol three times, and then dry them in an oven at 60-80°C for 18 hours to obtain modified particles A.

[0059] S3. calcining 70 parts of activated carbon in a muffle furnace at 350-400° C. under argon protection for 3 hours. After cooling, immersing in a 5% hydrochloric acid solution and stirring with a stirrer at 250 rpm for 4 hours, then washing with deionized water until the conductivity is less than 50 μS / cm, filtering through a filter, and drying in an oven at 100-120° C. for 18 hours to obtain pretreated activated carbon B.

[0060] S4, immersing the pretreated activated carbon B in 3 parts of the strengthening modifier, oscillating and depositing at 40°C for 6 hours, soaking in 0.1M HNO3 for 20 minutes to remove boron residue, washing with deionized water 3 times, and calcining in a muffle furnace at 250°C under argon protection for 40 minutes to obtain pretreated activated carbon C;

[0061] S5. Re-disperse the modified particles A in anhydrous ethanol, ultrasonically disperse them using an ultrasonic cleaner at 40 kHz, then add pretreated activated carbon C, stir with a magnetic stirrer at 250 rpm for 6 hours, and then vacuum impregnate for 3 hours to allow the modified particles A to self-assemble onto the surface and pores of the pretreated activated carbon C through physical adsorption and chemical bonding. Use a centrifuge to separate the particle-loaded activated carbon, wash it three times with anhydrous ethanol, and dry it in an oven at 60-80°C for 18 hours. Then, place it in a muffle furnace and heat-treat it under argon protection at 180°C for 1.5 hours to obtain superhydrophobic activated carbon.

[0062] The fluorosilane used is heptadecafluorodecyltrimethoxysilane.

[0063] Example 3:

[0064] S1. Weigh the following raw materials by mass: 90 parts activated carbon, 15 parts silica nanoparticles, 5 parts fluorosilane, and 7 parts strengthening modifier;

[0065] S2. 15 parts of silica nanoparticles were added to anhydrous ethanol and ultrasonically dispersed at 40 kHz for 30 minutes using an ultrasonic cleaner to form a uniform dispersion. 5 parts of fluorosilane were added while stirring with a magnetic stirrer at 400 rpm. The mixture was reacted at room temperature for 4 hours. The fluorosilane was first mixed with anhydrous ethanol and allowed to stand for 30 minutes. After the reaction, large particles were removed using a centrifuge at 2000 rpm, and then the modified particles were collected at 4000 rpm. After washing with anhydrous ethanol three times, the modified particles were dried in an oven at 60-80°C for 18 hours to obtain modified particles A.

[0066] S3. calcining 90 parts of activated carbon in a muffle furnace at 350-400° C. under argon protection for 3 hours. After cooling, immersing in a 5% hydrochloric acid solution and stirring with a stirrer at 250 rpm for 4 hours, then washing with deionized water until the conductivity is less than 50 μS / cm, filtering through a filter, and drying in an oven at 100-120° C. for 18 hours to obtain pretreated activated carbon B.

[0067] S4, immersing the pretreated activated carbon B in 7 parts of the strengthening modifier, shaking and depositing at 40 ° C for 6 hours, soaking in 0.1 M HNO3 for 20 minutes to remove boron residue, washing with deionized water three times, and calcining in a muffle furnace at 250 ° C for 40 minutes under argon protection to obtain pretreated activated carbon C;

[0068] S5. Re-disperse the modified particles A in anhydrous ethanol, ultrasonically disperse them using an ultrasonic cleaner at 40 kHz, then add pretreated activated carbon C, stir with a magnetic stirrer at 250 rpm for 6 hours, and then vacuum impregnate for 3 hours to allow the modified particles A to self-assemble onto the surface and pores of the pretreated activated carbon C through physical adsorption and chemical bonding. Use a centrifuge to separate the particle-loaded activated carbon, wash it three times with anhydrous ethanol, and dry it in an oven at 60-80°C for 18 hours. Then, place it in a muffle furnace and heat-treat it under argon protection at 180°C for 1.5 hours to obtain superhydrophobic activated carbon.

[0069] The fluorosilane used is heptadecafluorodecyltrimethoxysilane.

[0070] Comparative Example 1:

[0071] Step S4 in Example 2 was removed, and the pretreated activated carbon B was used to assemble the modified particles A, while the other raw materials remained unchanged to prepare superhydrophobic activated carbon;

[0072] Comparative Example 2:

[0073] Step S4 in Example 3 was removed, and the pretreated activated carbon B was used to assemble the modified particles A, while the other raw materials remained unchanged to prepare superhydrophobic activated carbon;

[0074] Experimental Example 1:

[0075] The super-hydrophobic activated carbon obtained in Examples 2 and 3 and Comparative Examples 1 and 2 was 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. The test results are shown in Table 1:

[0076] Table 1: Super hydrophobic activated carbon test table

[0077] Test items Example 2 Example 3 Comparative Example 1 Comparative Example 2 Static water contact angle (°) 151 154 128 130 Dynamic rolling 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] The static water contact angle was measured according to the standard GB / T 30693-2014. The sample was pressed into a 10×10 mm flat surface. A contact angle meter was used to add 5 μL of ultrapure water. The contact angle was calculated using the Young-Laplace equation. The average of the five points was taken as the static water contact angle. For the rolling angle, the sample stage was slowly tilted until the water droplet began to roll. The tilt angle of the sample stage at this time was recorded, which was the rolling angle. Each sample was measured five times, and the average value was taken as the dynamic rolling angle.

[0079] It can be seen that the hydrophobicity of superhydrophobic activated carbon is further improved by strengthening the interfacial bonding and reducing defects through strengthening the modifier.

[0080] The moisture absorption rate test is to weigh the mass m0 of the dried samples in Examples 2 and 3 and Comparative Examples 1 and 2 respectively, place them in a constant temperature and humidity chamber at a temperature of 25°C and a humidity of 90% RH for 48 hours, take them out and weigh the wet weight m1, and calculate the moisture absorption rate

[0081] The BET specific surface area retention rate test was performed by vacuum degassing the samples in Examples 2 and 3 and Comparative Examples 1 and 2 at 150° C. for 6 hours, and calculating the specific surface area using the BET model using the nitrogen adsorption method;

[0082] The toluene adsorption capacity test was performed by placing samples of Examples 2 and 3 and Comparative Examples 1 and 2 in a sealed chamber and introducing toluene vapor at a concentration of 500 ppm and a humidity of 80% RH until the samples of Examples 2 and 3 and Comparative Examples 1 and 2 were adsorbed to saturation, and the adsorption capacity per unit mass was calculated.

[0083] This shows that the strengthening modifier significantly improves the hydrophobic durability and anti-wet adsorption efficiency of superhydrophobic activated carbon through chemical anchoring and pore protection. Argon protection calcination carbonizes PDA to form a conductive network, enhancing the stability of the material. In comparative examples 1 and 2, the presence of unblocked -OH groups causes hygroscopic pore blockage, resulting in a 30-40% decrease in adsorption capacity.

[0084] In summary, the present invention adds a strengthening modifier to the raw material, and dopamine undergoes a self-polymerization reaction in an alkaline borate buffer to form polydopamine. Due to the large number of active functional groups such as catechol and amino groups contained in polydopamine, when the pretreated activated carbon B is immersed in the strengthening modifier, polydopamine is deposited on the surface of the activated carbon, and the active groups provide more binding sites for the subsequent self-assembly of the modified particles A, thereby enhancing the physical adsorption and chemical bonding between the modified particles A and the activated carbon, thereby enhancing the actual use effect of the superhydrophobic activated carbon.

[0085] The modified particles A are physically adsorbed by stirring with a magnetic stirrer, and the pore penetration is enhanced by vacuum impregnation. By constructing a relationship model between the water contact angle, adsorption amount, stirring time and impregnation time, and combining it with actual order requirements, the stirring time and impregnation time in the actual production process are flexibly set to optimize the actual production process.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A super hydrophobic activated carbon material, characterized in that, The raw materials include the following parts by weight: 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; Wherein, the strengthening 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 a borate buffer solution. Step 2: Add dopamine hydrochloride to borate buffer, ultrasonically disperse for 10 minutes, and react in stages at a constant temperature under light-proof conditions. First, introduce a nitrogen-air mixture to maintain the dissolved oxygen at 3-4 mg / L. After magnetic stirring for 2 hours, increase the temperature and continue the reaction for 4 hours. Concentrate through a 100 kDa ultrafiltration membrane to obtain an enhanced modifier.

2. A super hydrophobic 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 stirring speed of 200 rpm and a temperature of 24-26°C.

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

4. A method for preparing a super-hydrophobic activated carbon material according to any one of claims 1 to 3, characterized in that: The method comprises the following preparation steps: S1. Weigh the following raw materials by mass: 70-90 parts of activated carbon, 5-15 parts of silica nanoparticles, 1-5 parts of fluorosilane, and 3-7 parts of a strengthening 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. After the reaction is completed, the modified particles are separated using a centrifuge, washed with anhydrous ethanol 2-3 times, and then dried in an oven at 60-80° C. for 12-24 hours to obtain modified particles A. S3. calcining the activated carbon in a muffle furnace at 350-400° C. under argon protection for 2-4 hours. After cooling, immersing the activated carbon in a hydrochloric acid solution and stirring with a stirrer for 2-4 hours, then washing with deionized water until the conductivity is less than 50 μS / cm, filtering the solution through a filter, and drying the solution in an oven at 100-120° C. for 12-24 hours to obtain pretreated activated carbon B. S4, immersing the pretreated activated carbon B in the strengthening modifier, shaking and depositing at 40 ° C for 6 hours, soaking in 0.1M HNO3 for 20 minutes to remove the boron residue, washing with deionized water 2-3 times, and calcining in a muffle furnace at 250 ° C for 40 minutes under argon protection to obtain pretreated activated carbon C; S5. Re-disperse the modified particles A in anhydrous ethanol, ultrasonically disperse them using an ultrasonic cleaner, then add pretreated activated carbon C, stir with a magnetic stirrer for 4-8 hours, and then vacuum impregnate for 2-4 hours, so that the modified particles A are self-assembled onto the surface and pores of the pretreated activated carbon C through physical adsorption and chemical bonding. Use a centrifuge to separate the particle-loaded activated carbon, wash it with anhydrous ethanol 2-3 times, and dry it in an oven at 60-80°C for 12-24 hours. Then, place it in a muffle furnace and heat-treat it at 180-200°C under argon protection for 1.5 hours to obtain superhydrophobic activated carbon.

5. A method for preparing a super hydrophobic activated carbon material according to claim 4, characterized in that, Said S5 includes the step of determining the assembly time of the pre-treated activated carbon C: A comprehensive experimental design method was used to combine different values ​​of stirring time and immersion time to form multiple experimental conditions, among which the stirring time values ​​were 6, 6.5, 7, 7.5, and 8, and the immersion time values ​​were 2, 2.5, 3, 3.5, and 4, resulting in 25 experimental combinations; The modified particles A are redispersed in anhydrous ethanol, ultrasonically dispersed using an ultrasonic cleaner, pretreated activated carbon C is added, magnetic stirring is performed according to a set stirring time t1, and vacuum impregnation is performed according to a set impregnation time t2. The final superhydrophobic activated carbon sample is obtained according to step S5, the contact angle y of the sample is measured using a contact angle meter, and the adsorption amount z of the sample on a specific substance is measured through an adsorption experiment, and a linear model y = at1 + bt1 + c, z = dt1 + et1 + f is constructed; The least squares method is used to solve the parameters a, b, c, d, e, and f in the above linear model. Based on the water contact angle and adsorption amount under different order production requirements, two sets of stirring times and two sets of immersion times are obtained through the linear model. The maximum value of the stirring time and immersion time is selected as the stirring time and immersion time of the current order through the max function.

6. A method for preparing a super hydrophobic activated carbon material according to claim 4, characterized in that, The ultrasonic cleaning parameters in S2 are 40 kHz, the time is 30 minutes, the stirring speed of the magnetic stirrer is 400 rpm, and the centrifuge is a gradient centrifugation, first removing large particles at 2000 rpm, and then collecting target particles at 4000 rpm.

7. A super-hydrophobic activated carbon material, preparation method and application thereof according to claim 4, characterized in that: The heating rate of the muffle furnace in S3, S4 and S5 is 5°C / min, the concentration of the hydrochloric acid solution 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.

8. A method for preparing a super hydrophobic activated carbon material according to claim 4, characterized in that, The S5 super-cleaning parameters are 40 kHz, the time is 35 minutes, the stirring speed of the magnetic stirrer is 250 rpm, and the vacuum degree of the vacuum impregnation is -0.09 MPa.

9. A method for preparing a super hydrophobic activated carbon material according to claim 4, characterized in that, The fluorosilane is heptadecafluorodecyltrimethoxysilane.

10. An application of a super-hydrophobic activated carbon material obtained by the method for preparing super-hydrophobic activated carbon material according to claims 4-9, characterized in that: The super hydrophobic activated carbon material is used as an adsorption material.

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