A method for preparing a superhydrophobic textile based on biomass porous carbon

Abstract

The application relates to a preparation method of a biomass porous carbon-based super-hydrophobic textile, which comprises the following steps: taking a solution containing organosilicon and biomass porous carbon as finishing liquid, and sequentially carrying out padding, pre-drying and steaming on the textile to obtain the super-hydrophobic textile; wherein the content of the organosilicon in the solution containing organosilicon and biomass porous carbon is 0.5-8 wt%, the content of the biomass porous carbon is 0.1-5 wt%, the padding time is not less than 10 min, the steaming temperature is not less than 150 DEG C, and the steaming time is not less than 10 min. The biomass porous carbon is applied in the preparation of the super-hydrophobic textile for the first time, the prepared super-hydrophobic textile has electromagnetic wave absorption capacity, and the application field of the biomass porous carbon is widened.

Description

Technical Field

[0001] This invention belongs to the field of biomass renewable materials and chemical surface engineering, and relates to a method for preparing superhydrophobic textiles based on biomass porous carbon. Background Technology

[0002] In recent years, inspired by lotus leaves in nature, research on superhydrophobic materials has attracted widespread attention. Superhydrophobic textiles not only possess excellent water repellency but also good self-cleaning properties, and are widely used in protective clothing, shoes, tents, sleeping bags, and other applications. The water repellency of superhydrophobic textiles prevents water from soaking, aging, and degrading the substrate, thus extending their service life. Furthermore, the self-cleaning property of superhydrophobic textiles effectively reduces the number of washes, thereby avoiding the waste of resources and energy required for washing.

[0003] Currently, the commonly used method for constructing superhydrophobic surfaces involves mixing organic / inorganic nanoparticles with hydrophobic resins and then applying them to the surface of cotton fabrics through methods such as impregnation and spraying. For example, the literature "One-pot fabrication of superhydrophobic and flame-retardant coatings on cotton fabrics via sol-gel reaction[J]. Journal of Colloid and The paper "Interface Science, 2019, 533:198-206" describes the construction of a superhydrophobic and flame-retardant coating on cotton fabric using a sol-gel method. The cotton fabric was activated using oxygen plasma (oxygen ionization generates oxygen ions and free electrons; oxygen ions adsorb contaminants such as grease and dust from the material surface; simultaneously, free electrons break surface chemical bonds, thus activating the surface). The fabric was then immersed in an ethanol suspension containing tetraethoxysilane (TEOS), hydroxyl-terminated polydimethylsiloxane (HPDMS), and ammonium polyphosphate (APP). The hydrogen bonding between APP and cellulose allowed APP to adhere to the cotton fibers. Upon the addition of ammonia, TEOS and HPDMS underwent a sol-gel reaction to generate a polydimethylsiloxane-silica hybrid (PDMS-SiO2), which was then deposited in situ onto the cotton fabric surface. The treated cotton fabric surface forms a micro-nano composite coating composed of PDMS-SiO2 and APP, exhibiting excellent flame retardancy, self-cleaning ability, and durability. However, on the one hand, due to their extremely small size, nanoparticles released into the environment may pose a threat to human health. On the other hand, commonly used hydrophobic resins are mostly petroleum-based products or contain low surface energy fluorine, which are difficult to degrade and harmful to the human body, easily causing secondary environmental pollution. Therefore, research on superhydrophobic textile manufacturing has shifted its focus to finding environmentally friendly and sustainable alternatives, especially bio-derived materials. Developing green and environmentally friendly technologies and finding biomass resources to construct superhydrophobic cotton fabrics remains an unsolved problem.

[0004] Biomass porous carbon is a bio-derived material prepared from sugars or carbon-containing organic waste. It possesses advantages such as large specific surface area, high porosity, stable performance, and environmental friendliness, thus attracting widespread attention from researchers for its applications in soil conditioners, adsorbents, and electrode materials. Patent CN113149005A discloses a high specific surface area biomass porous carbon, its preparation method, and its applications. This method uses sodium lignosulfonate as a carbon precursor, and simultaneously employs an alkali activator and a nitrogen dopant to prepare biomass porous carbon. The biomass porous carbon is then used to remove chloramphenicol from water bodies.

[0005] However, existing technologies have not attempted to apply biomass porous carbon to the preparation of superhydrophobic textiles. If biomass porous carbon could be applied to the preparation of superhydrophobic textiles, it would be expected to expand the application field of biomass porous carbon and solve the problems existing in the preparation of superhydrophobic textiles using existing technologies. Summary of the Invention

[0006] The purpose of this invention is to solve the problems existing in the prior art and provide a method for preparing superhydrophobic textiles based on biomass porous carbon.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing superhydrophobic textiles based on biomass porous carbon involves using a solution containing organosilicon and biomass porous carbon as a finishing liquid, and sequentially padding, pre-drying, and steaming the textiles to obtain the superhydrophobic textiles. The steaming treatment serves two purposes: first, to remove the biomass porous carbon that is not firmly bonded to the surface of the textiles; and second, to firmly bond the organosilicon to the surface of the textiles.

[0009] The solution containing organosilicon and biomass porous carbon contains organosilicon at a content of 0.5–8 wt% and biomass porous carbon at a content of 0.1–5 wt%. The immersion time is not less than 10 min, the steaming temperature is not less than 150 °C, and the steaming time is not less than 10 min.

[0010] Typically, surface wettability is measured by the static contact angle between a solid surface and a droplet. The static contact angle is the angle θ between the solid-liquid interface and the gas-liquid interface when two tangents are drawn at the junction of the solid, liquid, and gas phases. When the θ of the solid surface is higher than 150°, the surface is called a superhydrophobic surface.

[0011] The static contact angle was first calculated using Young's equation. Young's equation states that when the gas and liquid phases remain constant, the solid surface energy decreases, the contact angle increases, and thus hydrophobicity is enhanced. This equation is based on an absolutely smooth and chemically homogeneous solid surface. When a water droplet is stationary on a solid surface, the static contact angle between the droplet and the solid surface is the result of the interaction of surface tensions at the solid-liquid-gas interface. Figure 4 As shown, θ is the static contact angle, γ SV γ SL and γ LV These represent the surface tensions at the solid-gas, solid-liquid, and liquid-gas interfaces, respectively. The force dynamics of the water droplet under these conditions conform to Young's equation:

[0012]

[0013] It is generally believed that when the static contact angle is less than 90°, the surface is hydrophilic; when the static contact angle is between 90° and 150°, the surface is hydrophobic; and when the water contact angle is greater than 150°, the surface is superhydrophobic.

[0014] However, such a surface does not exist in reality. Considering that the surface of a real solid has a certain degree of roughness, Wenzel and Cassie-Baxter successively modified Young's equation, proposing the Wenzel model and the Cassie-Baxter model. The Wenzel model assumes that when water droplets fill the grooves on the rough surface of a solid, the solid surface is completely wetted, such as... Figure 5 (a) The Wenzel model suggests that if the roughness of the solid surface of a hydrophobic material increases, the hydrophobicity of the surface of the hydrophobic material will further increase.

[0015] As the contact area increases, the surface tension at the solid-liquid interface changes, thus affecting the contact angle between the droplet and the solid surface. Wenzel considered the factor that the droplet might fill the interior of the rough solid surface, and added a roughness coefficient r to Young's equation to reflect the surface roughness of the solid, as shown in the following expression:

[0016]

[0017] In the formula, s represents the actual surface area; s' represents the ideal surface area.

[0018] The Wenzel equation is as follows:

[0019] cosθ w =r cosθ;

[0020] In the formula, θw is the apparent contact angle of the rough surface, and θ is the contact angle of the ideal surface;

[0021] According to the Wenzel equation, r>1. Under this model, roughness can make hydrophobic surfaces more hydrophobic (θw>θ) and hydrophilic surfaces more hydrophilic (θw<θ).

[0022] The Cassie-Baxter model posits that the contact between water droplets and a rough surface is actually a solid-liquid-gas three-phase complex contact, such as... Figure 5 (b) The water droplet does not completely wet the surface; air is present in the contact area between the water droplet and the solid surface. Increasing the contact area between the solid and the air increases the contact angle of the water droplet on the solid material surface, thereby improving hydrophobicity. The expression of the Cassie-Baxter equation is as follows:

[0023] cosθ CB = f1cosθ1 + f2cosθ2;

[0024] In the formula, f1 and f2 are the percentages of the droplet surface area in contact with the two phases, respectively, and θ1 and θ2 are the static contact angles between the droplet and the two phases, respectively. When one of the phases is a gas phase, the above formula can be converted into the following formula.

[0025] cosθ CB =f(1+cosθ) w -1;

[0026] Therefore, according to Young's equation, Wenzel model and Cassie-Baxter model, the preparation of superhydrophobic materials requires the simultaneous fulfillment of two conditions: one is a micro-rough structure; the other is a low surface energy material; the two work together to achieve the preparation of superhydrophobic materials.

[0027] This invention applies organosilicon and biomass porous carbon together to the surface of textiles, while optimizing process parameters to endow the textiles with a micro-rough metasurface and low surface energy, wherein:

[0028] The role of porous carbon from biomass is to impart microscopic roughness to textiles via metasurfaces;

[0029] Organosilicon has two functions: first, to provide low surface energy; and second, to effectively combine porous biomass carbon with fabrics. Organosilicon has excellent adhesion and can also firmly adhere porous biomass carbon to fabrics.

[0030] Controlling the content of organosilicon in a solution containing organosilicon and biomass porous carbon, with organosilicon content ranging from 0.5 to 8 wt% and biomass porous carbon content ranging from 0.1 to 5 wt%, can give textiles a microscopically rough surface and low surface energy, satisfying the two basic conditions for constructing a superhydrophobic surface. Excessive organosilicon content will form a relatively smooth coating layer on the textile surface, reducing surface irregularity and leading to a slight decrease in the contact angle. Insufficient organosilicon content cannot provide enough low surface energy for the rough surface. Under a certain organosilicon concentration, the amount of biomass porous carbon that textiles can load is fixed. When the amount is too small, it cannot provide enough microscopically rough structure. When the amount is too large, it cannot provide more low surface energy for the rough surface, and instead, it will lead to a decrease in the water droplet contact angle of the textile.

[0031] The purpose of controlling the padding time to be no less than 10 minutes and the steaming temperature to be no less than 150℃, and the steaming time to be no less than 10 minutes, is to fully, uniformly and firmly composite the biomass porous carbon and organosilicon onto the textile to form a superhydrophobic surface. Too short a padding time will not be able to uniformly composite the organosilicon and composite material onto the textile surface. The steaming time and temperature are set in this way so that the fiber can be expanded by heating, so that the organosilicon can be fully composited.

[0032] As a preferred option:

[0033] The method described above for preparing superhydrophobic textiles based on biomass porous carbon, wherein the biomass porous carbon has a microscopically rough porous structure and a specific surface area of ​​825.9–1620 m², is described. 2 / g contains a large number of porous rough structures such as micropores, mesopores and macropores. When micropores, mesopores and macropores coexist and the specific surface area is large, the better the roughness, the better the performance of the prepared superhydrophobic textile.

[0034] The preparation method of superhydrophobic textiles based on biomass porous carbon, as described above, involves the following steps: First, biomass materials are processed into biomass powder to make the particles smaller and more uniform (specifically, the biomass materials are repeatedly washed, then dried in an oven, and the dried biomass materials are pulverized into powder and sieved). Then, the biomass powder is carbonized in a tube furnace. Next, strong alkalis such as KOH or NaOH are added to the carbonized biomass powder, and activation is carried out in a tube furnace. During this process, the strong alkali reacts with the biomass carbon material to generate gases such as CO2 and H2O, and releases oxidation products such as potassium carbonate. The release of gases and the generation of oxidation products cause internal changes in the biomass carbon material, thereby giving it a porous structure. Finally, post-treatment is performed (specifically, the material is first washed in acid until neutral, then dried in an oven, and then ground into powder) to obtain biomass porous carbon.

[0035] The method for preparing superhydrophobic textiles based on biomass porous carbon as described above uses one or more of the following biomass materials: peanut shells, sugarcane bagasse, corn cobs, crop straw, and rice husks; the carbonization temperature is 500–800℃, and the time is 60–210 min; the mass ratio of strong alkali to carbonized biomass powder is 0.5–4:1; the activation temperature is 550–850℃, and the time is 60–210 min; the process for preparing biomass porous carbon in this invention has been optimized, resulting in biomass porous carbon with more uniform pores and a significantly rough porous structure.

[0036] In the preparation method of superhydrophobic textiles based on biomass porous carbon as described above, the organosilicon is one or more of hexadecyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, polydimethylsiloxane, and polydimethylhydroxysiloxane.

[0037] In the preparation method of superhydrophobic textiles based on biomass porous carbon as described above, the solvent in the solution containing organosilicon and biomass porous carbon is one or more of isopropanol, n-hexane, benzyl alcohol, acetone, N,N-dimethylformamide and ethyl acetate.

[0038] As described above, in the preparation method of superhydrophobic textiles based on biomass porous carbon, the pre-drying temperature is 50-100℃ and the pre-drying time is 5-30 minutes. The purpose of pre-drying is to allow the textiles to be initially dried. If the pre-drying temperature or the pre-drying time is too high or too long, it will damage the textiles.

[0039] The method for preparing a superhydrophobic textile based on biomass porous carbon, as described above, involves a padding liquid rate of 80%–90% and a padding line pressure of 200–350 N / cm.

[0040] The method for preparing a superhydrophobic textile based on biomass porous carbon as described above, wherein the textile is polyester fabric, nylon fabric, cotton fabric, Tencel fabric, Modal fabric or cellulose acetate fabric.

[0041] The method for preparing superhydrophobic textiles based on biomass porous carbon, as described above, results in a superhydrophobic textile with a water contact angle greater than 150°. When stains such as cola, milk, and coffee are poured onto the superhydrophobic textile, the stain droplets also exhibit a contact angle exceeding 157°. Furthermore, when powdery stains such as chalk dust are poured onto the superhydrophobic textile, the powdery stains can be easily removed with water. Therefore, the superhydrophobic textile prepared by this invention possesses excellent water repellency, stain resistance, and self-cleaning properties. In addition, unexpectedly, this invention reveals the lowest reflection loss of the superhydrophobic textile (measured using a vector network analyzer). The microwave absorption of the prepared superhydrophobic textile was tested and found to be -20 to -40 dB, indicating that the superhydrophobic textile of this invention has good microwave absorption capability. This may be because the microporous structure of biomass porous carbon induces multiple reflections and scatterings of electromagnetic waves, and generates interfacial polarization, providing dielectric loss performance. The microwave absorption mechanism of the finished fabric is mainly dielectric loss. Given the good microwave absorption capability of the superhydrophobic textile of this invention, it is expected to be used in functional textiles that absorb electromagnetic waves, thus solving the problem of electromagnetic wave harm to the human body.

[0042] Beneficial effects:

[0043] (1) Biomass porous carbon itself does not have superhydrophobic properties. This invention is the first to apply it to the preparation of superhydrophobic textiles, which broadens the application field of biomass porous carbon.

[0044] (2) The method of the present invention is simple, the preparation conditions are mild, and it is easy to operate. The raw materials are taken from biomass waste, which is abundant and readily available, realizing the reuse of resources and meeting the inherent requirements of my country to promote high-quality economic development and high-level ecological environment protection.

[0045] (3) The superhydrophobic textile based on biomass porous carbon prepared by the present invention has excellent superhydrophobic properties, good electromagnetic wave absorption ability, and also has the softness of textiles, as well as self-cleaning and anti-fouling functions. It can effectively avoid the adhesion or corrosion damage of pollutants, extend the service life of textiles, and has great development prospects. Attached Figure Description

[0046] Figure 1 This is a scanning electron microscope image of the biomass porous carbon from Example 1;

[0047] Figure 2 This is a scanning electron microscope image of the superhydrophobic textile of Example 1;

[0048] Figure 3 The water droplet contact angle diagram of the superhydrophobic textile prepared in Example 1;

[0049] Figure 4 This is a schematic diagram of the static contact angle;

[0050] Figure 5 The two models are the Wenzel model and the Cassie-Baxter model, where (a) is the Wenzel model and (b) is the Cassie-Baxter model. Detailed Implementation

[0051] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0052] The following are the test methods for each performance aspect in the examples:

[0053] Minimum reflection loss: Microwave absorption performance was tested using the waveguide method in the range of 8.2–12.4 GHz with a vector network analyzer.

[0054] Specific surface area: The specific surface area was measured using an AUTOSORBIQ Quantachrome USA BET tester.

[0055] Example 1

[0056] A method for preparing superhydrophobic textiles based on biomass porous carbon, comprising the following steps:

[0057] (1) Preparation of raw materials;

[0058] Biomass material: peanut shells;

[0059] Strong base: KOH;

[0060] Organosilicon: hexadecyltrimethoxysilane;

[0061] Solvent: Isopropanol;

[0062] Textiles: Cotton fabrics;

[0063] (2) Preparation of porous carbon from biomass;

[0064] After repeatedly washing the biomass material in deionized water, it was dried in an oven. The dried biomass material was then pulverized into powder and sieved. The sieved biomass powder was then carbonized in a tube furnace at 600°C for 120 minutes. Next, a strong alkali was added to the carbonized biomass powder, and it was activated in a tube furnace at 650°C for 120 minutes to give the biomass carbon a porous structure. The carbon was then washed in acid until neutral, dried completely in an oven, and then ground into powder to obtain porous biomass carbon. The mass ratio of the strong alkali to the carbonized biomass powder was 3:1.

[0065] The biomass porous carbon produced, such as Figure 1 As shown, it has a micro-rough porous structure with a specific surface area of ​​1488 m². 2 / g;

[0066] (3) Prepare the finishing solution;

[0067] After mixing the organosilicon, the biomass porous carbon obtained in step (2), and the solvent evenly, a finishing solution is obtained; wherein the content of organosilicon is 4wt% and the content of biomass porous carbon is 0.3wt%.

[0068] (4) Using the finishing solution prepared in step (3), the textile is sequentially subjected to padding (two dips and two nips), pre-drying, and steaming to obtain the superhydrophobic textile; wherein, the padding time (i.e., the total time of two dips and two nips) is 20 min, the padding liquid rate is 80%, the padding line pressure is 300 N / cm, the pre-drying temperature is 80℃, the pre-drying time is 15 min, the steaming temperature is 150℃, and the steaming time is 60 min.

[0069] The final superhydrophobic textiles produced are as follows Figure 2 and Figure 3 As shown, the water contact angle is 168.3°, and the minimum reflection loss of the superhydrophobic textile is -33dB.

[0070] Comparative Example 1

[0071] A method for preparing a superhydrophobic textile based on biomass porous carbon is basically the same as in Example 1, except that the content of organosilicon in the finishing solution prepared in step (3) is 0.3 wt%.

[0072] The final superhydrophobic textile produced has a water contact angle of 145° and a minimum reflection loss of -10dB.

[0073] Comparing Comparative Example 1 and Example 1, it can be seen that the low content of organosilicon in the finishing liquid used in Comparative Example 1 leads to a decrease in the water droplet contact angle and a decrease in the minimum reflection loss. This is because the reduced content of organosilicon cannot provide enough low surface energy and cannot composite enough biomass porous carbon, so it cannot provide a good minimum reflection loss value.

[0074] Comparative Example 2

[0075] A method for preparing superhydrophobic textiles based on biomass porous carbon is basically the same as in Example 1, except that the content of organosilicon in the finishing solution prepared in step (3) is 9 wt%.

[0076] The final superhydrophobic textile produced has a water contact angle of 148.2° and a minimum reflection loss of -28dB.

[0077] Comparing Comparative Example 2 and Example 1, it can be seen that the high content of silicone in the finishing liquid used in Comparative Example 2 leads to a decrease in the water droplet contact angle and the minimum reflection loss. This is because excessive silicone content forms a smoother coating on the surface of textiles, reducing the micro-roughness of the surface, resulting in a slight decrease in the contact angle and a decrease in the minimum reflection loss value.

[0078] Comparative Example 3

[0079] A method for preparing superhydrophobic textiles based on biomass porous carbon is basically the same as in Example 1, except that the content of biomass porous carbon in the finishing solution prepared in step (3) is 0.05 wt%.

[0080] The final superhydrophobic textile produced has a water contact angle of 148° and a minimum reflection loss of -12dB.

[0081] Comparing Comparative Example 3 and Example 1, it can be seen that the low content of biomass porous carbon in the finishing liquid used in Comparative Example 3 leads to a decrease in the water droplet contact angle and the minimum reflection loss. This is because the low content of biomass porous carbon material cannot provide sufficient micro-roughness, resulting in a decrease in the water droplet contact angle. Furthermore, the low content of biomass porous carbon will reduce the minimum reflection loss value of the finished fabric.

[0082] Comparative Example 4

[0083] A method for preparing superhydrophobic textiles based on biomass porous carbon is basically the same as in Example 1, except that the content of biomass porous carbon in the finishing solution prepared in step (3) is 6 wt%.

[0084] The final superhydrophobic textile produced has a water contact angle of 149° and a minimum reflection loss of -32dB.

[0085] Comparing Comparative Example 4 and Example 1, it can be seen that the water droplet contact angle is reduced because the content of biomass porous carbon in the finishing liquid used in Comparative Example 4 is too high. This is because the content of biomass porous carbon that can be loaded by organosilicon at a certain concentration is fixed. Increasing the biomass carbon content will reduce the surface energy, resulting in a decrease in the water droplet contact angle, but the minimum reflection loss does not change much.

[0086] Comparative Example 5

[0087] A method for preparing a superhydrophobic textile based on biomass porous carbon is basically the same as in Example 1, except that the time for impregnating the textile in step (4) is 8 minutes.

[0088] The final superhydrophobic textile produced has a water contact angle of 147.5° and a minimum reflection loss of -27.2dB.

[0089] Comparing Comparative Example 5 and Example 1, it can be seen that the water droplet contact angle and the minimum reflection loss are reduced because the padding time of the textile in Comparative Example 5 is too short. This is because the padding time is too short, and the biomass porous carbon and organosilicon cannot be fully, uniformly and firmly compounded on the textile.

[0090] Comparative Example 6

[0091] A method for preparing superhydrophobic textiles based on biomass porous carbon is basically the same as in Example 1, except that the temperature for steaming the textiles in step (4) is 120°C.

[0092] The final superhydrophobic textile produced has a water contact angle of 143.3° and a reflection loss of -30dB.

[0093] Comparing Comparative Example 6 and Example 1, it can be seen that the water droplet contact angle and minimum reflection loss are reduced because the steaming temperature of the textile in Comparative Example 6 is too low. This is because the steaming temperature is too low to allow the organosilicon to fully adhere to the textile, and thus cannot provide enough low surface energy, causing some of the biomass porous carbon to fall off.

[0094] Comparative Example 7

[0095] A method for preparing superhydrophobic textiles based on biomass porous carbon is basically the same as in Example 1, except that the steaming time for the textiles in step (4) is 7 minutes.

[0096] The final superhydrophobic textile produced had a water contact angle of 144.9° and a reflection loss of -29.8dB.

[0097] Comparing Comparative Example 7 and Example 1, it can be seen that the water droplet contact angle and minimum reflection loss are reduced because the steaming time of the textile in Comparative Example 7 is too short. This is because the steaming time is too short to allow the organosilicon to fully adhere to the textile, and thus cannot provide sufficient low surface energy, causing some of the biomass porous carbon to fall off.

[0098] Example 2

[0099] A method for preparing superhydrophobic textiles based on biomass porous carbon, comprising the following steps:

[0100] (1) Preparation of raw materials;

[0101] Biomass material: sugarcane bagasse;

[0102] Strong base: K2CO3;

[0103] Organosilicon: γ-methacryloyloxypropyltrimethoxysilane;

[0104] Solvent: n-hexane;

[0105] Textiles: Nylon fabrics;

[0106] (2) Preparation of porous carbon from biomass;

[0107] After repeatedly washing the biomass material in deionized water, it was dried in an oven. The dried biomass material was then pulverized into powder and sieved. The sieved biomass powder was then carbonized in a tube furnace at 800°C for 180 minutes. Next, a strong alkali was added to the carbonized biomass powder, and it was activated in a tube furnace at 850°C for 180 minutes to give the biomass carbon a porous structure. The material was then washed in acid until neutral, dried completely in an oven, and then ground into powder to obtain porous biomass carbon. The mass ratio of the strong alkali to the carbonized biomass powder was 2:1.

[0108] The prepared biomass porous carbon has a micro-rough porous structure and a specific surface area of ​​1620 m². 2 / g;

[0109] (3) Prepare the finishing solution;

[0110] After the organosilicon, the biomass porous carbon obtained in step (2) and the solvent are mixed evenly, the finishing solution is obtained; wherein the content of organosilicon is 3wt% and the content of biomass porous carbon is 0.4wt%.

[0111] (4) Using the finishing solution prepared in step (3), the textile is sequentially subjected to padding (two dips and two nips), pre-drying, and steaming to obtain the superhydrophobic textile; wherein, the padding time (i.e., the total time of two dips and two nips) is 20 min, the padding liquid rate is 85%, the padding line pressure is 300 N / cm, the pre-drying temperature is 80℃, the pre-drying time is 15 min, the steaming temperature is 150℃, and the steaming time is 60 min.

[0112] The final superhydrophobic textile produced has a water contact angle of 161.5° and a minimum reflection loss of -35dB.

[0113] Example 3

[0114] A method for preparing superhydrophobic textiles based on biomass porous carbon, comprising the following steps:

[0115] (1) Preparation of raw materials;

[0116] Biomass material: corn cob;

[0117] Strong base: CaCO3;

[0118] Organosilicon: Polydimethylsiloxane;

[0119] Solvent: Benzyl alcohol;

[0120] Textiles: Polyester fabrics;

[0121] (2) Preparation of porous carbon from biomass;

[0122] After repeatedly washing the biomass material in deionized water, it was dried in an oven. The dried biomass material was then pulverized into powder and sieved. The sieved biomass powder was then carbonized in a tube furnace at 700°C for 150 minutes. Next, a strong alkali was added to the carbonized biomass powder, and it was activated in a tube furnace at 750°C for 150 minutes to give the biomass carbon a porous structure. The carbon was then washed in acid until neutral, dried completely in an oven, and then ground into powder to obtain porous biomass carbon. The mass ratio of the strong alkali to the carbonized biomass powder was 0.5:1.

[0123] The prepared biomass porous carbon has a micro-rough porous structure and a specific surface area of ​​1108 m². 2 / g;

[0124] (3) Prepare the finishing solution;

[0125] After the organosilicon, the biomass porous carbon obtained in step (2) and the solvent are mixed evenly, the finishing solution is obtained; wherein the content of organosilicon is 4wt% and the content of biomass porous carbon is 0.5wt%.

[0126] (4) Using the finishing solution prepared in step (3), the textile is sequentially subjected to padding (two dips and two nips), pre-drying, and steaming to obtain the superhydrophobic textile; wherein, the padding time (i.e., the total time of two dips and two nips) is 20 min, the padding liquid rate is 85%, the padding line pressure is 300 N / cm, the pre-drying temperature is 80℃, the pre-drying time is 15 min, the steaming temperature is 150℃, and the steaming time is 60 min.

[0127] The final superhydrophobic textile produced has a water contact angle of 158.1° and a minimum reflection loss of -32.1dB.

[0128] Example 4

[0129] A method for preparing superhydrophobic textiles based on biomass porous carbon, comprising the following steps:

[0130] (1) Preparation of raw materials;

[0131] Biomass materials: crop straw;

[0132] Strong base: NaOH;

[0133] Organosilicon: Polydimethylhydroxysiloxane;

[0134] Solvent: Acetone;

[0135] Textiles: Tencel fabric;

[0136] (2) Preparation of porous carbon from biomass;

[0137] After repeatedly washing the biomass material in deionized water, it was dried in an oven. The dried biomass material was then pulverized into powder and sieved. The sieved biomass powder was then carbonized in a tube furnace at 550°C for 180 minutes. Next, a strong alkali was added to the carbonized biomass powder, and it was activated in a tube furnace at 550°C for 180 minutes to give the biomass carbon a porous structure. The carbon was then washed in acid until neutral, dried completely in an oven, and then ground into powder to obtain porous biomass carbon. The mass ratio of the strong alkali to the carbonized biomass powder was 1:1.

[0138] The prepared biomass porous carbon has a micro-rough porous structure and a specific surface area of ​​825.9 m². 2 / g;

[0139] (3) Prepare the finishing solution;

[0140] After mixing the organosilicon, the biomass porous carbon obtained in step (2), and the solvent evenly, a finishing solution is obtained; wherein the content of organosilicon is 2wt% and the content of biomass porous carbon is 0.1wt%.

[0141] (4) Using the finishing solution prepared in step (3), the textile is sequentially subjected to padding (two dips and two nips), pre-drying, and steaming to obtain the superhydrophobic textile; wherein, the padding time (i.e., the total time of two dips and two nips) is 10 min, the padding liquid rate is 85%, the padding line pressure is 200 N / cm, the pre-drying temperature is 50℃, the pre-drying time is 30 min, the steaming temperature is 190℃, and the steaming time is 20 min.

[0142] The final superhydrophobic textile produced has a water contact angle of 155.9° and a minimum reflection loss of -33.17dB.

[0143] Example 5

[0144] A method for preparing superhydrophobic textiles based on biomass porous carbon, comprising the following steps:

[0145] (1) Preparation of raw materials;

[0146] Biomass material: coconut shell;

[0147] Strong base: Ca(OH)2;

[0148] Organosilicon: Polydimethylsiloxane;

[0149] Solvent: N,N-dimethylformyl;

[0150] Textiles: Modal fabric;

[0151] (2) Preparation of porous carbon from biomass;

[0152] After repeatedly washing the biomass material in deionized water, it was dried in an oven. The dried biomass material was then pulverized into powder and sieved. The sieved biomass powder was then carbonized in a tube furnace at 750°C for 120 minutes. Next, a strong alkali was added to the carbonized biomass powder, and it was activated in a tube furnace at 800°C for 120 minutes to give the biomass carbon a porous structure. The carbon was then washed in acid until neutral, dried completely in an oven, and then ground into powder to obtain porous biomass carbon. The mass ratio of the strong alkali to the carbonized biomass powder was 2.5:1.

[0153] The prepared biomass porous carbon has a micro-rough porous structure and a specific surface area of ​​965 m². 2 / g;

[0154] (3) Prepare the finishing solution;

[0155] After the organosilicon, the biomass porous carbon obtained in step (2) and the solvent are mixed evenly, the finishing solution is obtained; wherein the content of organosilicon is 1 wt% and the content of biomass porous carbon is 5 wt%.

[0156] (4) Using the finishing solution prepared in step (3), the textile is sequentially subjected to padding (two dips and two nips), pre-drying, and steaming to obtain the superhydrophobic textile; wherein, the padding time (i.e., the total time of two dips and two nips) is 25 min, the padding liquid rate is 85%, the padding line pressure is 300 N / cm, the pre-drying temperature is 90℃, the pre-drying time is 10 min, the steaming temperature is 180℃, and the steaming time is 60 min.

[0157] The final superhydrophobic textile produced has a water contact angle of 160.5° and a minimum reflection loss of -38dB.

[0158] Example 6

[0159] A method for preparing superhydrophobic textiles based on biomass porous carbon, comprising the following steps:

[0160] (1) Preparation of raw materials;

[0161] Biomass material: grapefruit peel;

[0162] Strong base: Ba(OH)2;

[0163] Organosilicon: hexadecyltrimethoxysilane;

[0164] Solvent: Ethyl acetate;

[0165] Textiles: Acetate fiber fabric;

[0166] (2) Preparation of porous carbon from biomass;

[0167] After repeatedly washing the biomass material in deionized water, it was dried in an oven. The dried biomass material was then pulverized into powder and sieved. The sieved biomass powder was then carbonized in a tube furnace at 500°C for 60 minutes. Next, a strong alkali was added to the carbonized biomass powder, and it was activated in a tube furnace at 550°C for 60 minutes to give the biomass carbon a porous structure. The carbon was then washed in acid until neutral, dried completely in an oven, and then ground into powder to obtain porous biomass carbon. The mass ratio of the strong alkali to the carbonized biomass powder was 2:1.

[0168] The prepared biomass porous carbon has a micro-rough porous structure and a specific surface area of ​​1267.45 m². 2 / g;

[0169] (3) Prepare the finishing solution;

[0170] After mixing the organosilicon, the biomass porous carbon obtained in step (2), and the solvent evenly, a finishing solution is obtained; wherein the content of organosilicon is 0.5wt% and the content of biomass porous carbon is 0.3wt%.

[0171] (4) Using the finishing solution prepared in step (3), the textile is sequentially subjected to padding (two dips and two nips), pre-drying, and steaming to obtain the superhydrophobic textile; wherein, the padding time (i.e., the total time of two dips and two nips) is 20 min, the padding liquid rate is 85%, the padding line pressure is 300 N / cm, the pre-drying temperature is 80℃, the pre-drying time is 15 min, the steaming temperature is 150℃, and the steaming time is 60 min.

[0172] The final superhydrophobic textile produced has a water contact angle of 155.6° and a minimum reflection loss of -21dB.

[0173] Example 7

[0174] A method for preparing superhydrophobic textiles based on biomass porous carbon, comprising the following steps:

[0175] (1) Preparation of raw materials;

[0176] Biomass material: a mixture of peanut shells and corn cobs in a 1:1 mass ratio;

[0177] Strong base: MgCO3;

[0178] Organosilicon: A mixture of polydimethylsiloxane and polydimethylhydroxysiloxane in a mass ratio of 1:1;

[0179] Solvent: A mixture of isopropanol and n-hexane in a mass ratio of 1:1;

[0180] Textiles: Cotton fabrics;

[0181] (2) Preparation of porous carbon from biomass;

[0182] After repeatedly washing the biomass material in deionized water, it was dried in an oven. The dried biomass material was then pulverized into powder and sieved. The sieved biomass powder was then carbonized in a tube furnace at 650°C for 210 minutes. Next, a strong alkali was added to the carbonized biomass powder, and it was activated in a tube furnace at 700°C for 210 minutes to give the biomass carbon a porous structure. The carbon was then washed in acid until neutral, dried completely in an oven, and then ground into powder to obtain porous biomass carbon. The mass ratio of the strong alkali to the carbonized biomass powder was 4:1.

[0183] The prepared biomass porous carbon has a micro-rough porous structure and a specific surface area of ​​1037.6 m². 2 / g;

[0184] (3) Prepare the finishing solution;

[0185] After the organosilicon, the biomass porous carbon obtained in step (2) and the solvent are mixed evenly, the finishing solution is obtained; wherein the content of organosilicon is 8wt% and the content of biomass porous carbon is 5wt%.

[0186] (4) Using the finishing solution prepared in step (3), the textile is sequentially subjected to padding (two dips and two nips), pre-drying, and steaming to obtain the superhydrophobic textile; wherein, the padding time (i.e., the total time of two dips and two nips) is 30 min, the padding liquid rate is 90%, the padding line pressure is 350 N / cm, the pre-drying temperature is 100℃, the pre-drying time is 5 min, the steaming temperature is 200℃, and the steaming time is 10 min.

[0187] The final superhydrophobic textile produced has a water contact angle of 161.3° and a minimum reflection loss of -39.2dB.

Claims

1. A method for preparing superhydrophobic textiles based on biomass porous carbon, characterized in that, A solution containing organosilicon and biomass porous carbon is used as the finishing liquid. Textiles are then subjected to padding, pre-drying, and steaming in sequence to obtain superhydrophobic textiles. The solution containing organosilicon and biomass porous carbon contains organosilicon at a content of 0.5-8 wt% and biomass porous carbon at a content of 0.1-5 wt%. The immersion time is not less than 10 min, the steaming temperature is not less than 150℃, and the steaming time is not less than 10 min. The organosilicon is one or more of hexadecyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, polydimethylsiloxane, and polydimethylhydroxysiloxane; Biomass porous carbon has a microscopically rough porous structure with a specific surface area of ​​825.9~1620 m². 2 / g; The preparation process of biomass porous carbon is as follows: First, biomass material is processed into biomass powder, then the biomass powder is carbonized, then a strong alkali is added to the carbonized biomass powder for activation, and finally post-treatment is carried out to obtain biomass porous carbon. The biomass material is one or more of peanut shells, sugarcane bagasse, corn cobs, crop straw, and rice husks; the carbonization temperature is 500~800℃ and the time is 60~210min; the mass ratio of strong alkali to carbonized biomass powder is 0.5~4:1; the activation temperature is 550~850℃ and the time is 60~210min.

2. The method for preparing a superhydrophobic textile based on biomass porous carbon according to claim 1, characterized in that, In a solution containing organosilicon and biomass porous carbon, the solvent is one or more of isopropanol, n-hexane, benzyl alcohol, acetone, N,N-dimethylformamide, and ethyl acetate.

3. The method for preparing a superhydrophobic textile based on biomass porous carbon according to claim 1, characterized in that, The pre-drying temperature is 50~100℃, and the pre-drying time is 5~30min.

4. The method for preparing a superhydrophobic textile based on biomass porous carbon according to claim 1, characterized in that, The slurry rate of the impregnation rolling is 80%~90%, and the rolling mill line pressure is 200~350N / cm.

5. The method for preparing a superhydrophobic textile based on biomass porous carbon according to claim 1, characterized in that, Textiles include polyester fabrics, nylon fabrics, cotton fabrics, Tencel fabrics, Modal fabrics, or acetate fabrics.

6. A method for preparing a superhydrophobic textile based on biomass porous carbon according to any one of claims 1 to 5, characterized in that, The water contact angle of superhydrophobic textiles is greater than 150°, and the minimum reflection loss of superhydrophobic textiles is -20 to -40 dB.

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