A method of making and using an inorganic fiber composite

Abstract

The application belongs to the technical field of composite materials, and particularly discloses a preparation method and application of an inorganic fiber composite material.The inorganic fiber composite material is prepared by mixing a mixed solution of a short-chain binary fatty alcohol, a binary organic acid and a titanium source as a precursor, mixing the precursor with inorganic mineral fibers uniformly, and then performing a hydrothermal reaction.The inorganic mineral fibers are used as a substrate of an oil-water separation membrane, and nano-titanium dioxide is loaded on the substrate to construct the inorganic fiber composite material with special surface wettability of super-hydrophilicity and super-oleophobicity underwater.The preparation method of the composite material is simple, and the cost is low.The oil-water separation efficiency of the oil-water separation membrane prepared by using the composite material is high, the oil-water separation membrane can be recycled and reused, and the oil leakage crisis can be greatly alleviated.

Description

Technical Field

[0001] This invention relates to the field of composite materials technology, and specifically discloses a method for preparing and applying inorganic fiber composite materials. Background Technology

[0002] Traditional methods for dealing with oil spills include oil booms, on-site incineration, adding dispersants, manual recovery, adding coagulants, biological technologies, and ordinary separation membranes. These methods have problems such as high cost, low efficiency, difficulty in recovering spilled oil, and secondary pollution. In addition, most of the materials used in handling oil spills are single-use products and cannot be recycled and reused.

[0003] Oil-water separation membrane technology is an advanced separation and purification method that has attracted attention due to its high efficiency, simple operation, and low energy consumption. However, its application in oil spill situations is very limited. Only a few organic separation membranes are used in oil spill treatment, and they are still single-use products. After use, the membrane surface becomes contaminated and loses its separation performance, making them impossible to recycle and reuse. Moreover, they are expensive to manufacture.

[0004] In recent years, composite materials have attracted increasing attention as oil-water separation membranes. Existing technology provides a composite material synthesized via a hydrothermal method using nano-TiO2 powder and chopped basalt fibers as raw materials. This composite material increases the surface area of ​​TiO2, improves its absorption wavelength range, enabling photocatalysis under visible light, and allows for the recycling and reuse of TiO2. It provides a new material for wastewater treatment. However, it still suffers from drawbacks such as a relatively cumbersome preparation process requiring pretreatment of the basalt fibers, the dispersed nature of the chopped fibers making recycling difficult, and the possibility of fiber loss during each recycling process, preventing complete recovery. Therefore, developing a composite material with high oil-water separation efficiency, a simple preparation process, low cost, and recyclability after use is of great significance for mitigating the oil spill crisis. Summary of the Invention

[0005] To address the problems of low oil-water separation efficiency, complex preparation processes, high costs, and inability to recycle existing composite materials, this invention provides a method for preparing and applying an inorganic fiber composite material. Using inorganic mineral fibers as the substrate for an oil-water separation membrane, nano-titanium dioxide is loaded onto the substrate to construct an inorganic fiber composite material with superhydrophilic / underwater superoleophobic surface wettability. The preparation method of this composite material is simple and inexpensive. The oil-water separation membrane prepared using this composite material has high oil-water separation efficiency and can be recycled, which can greatly alleviate the oil spill crisis.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] The first aspect of this invention provides a method for preparing an inorganic fiber composite material, comprising at least the following steps:

[0008] Step 1: Mix the short-chain dihydroxy alcohol, dihydroxy organic acid and titanium source evenly to obtain a precursor solution;

[0009] Step 2: After mixing the inorganic mineral fibers and the precursor solution evenly, perform a hydrothermal reaction, filter, wash, and dry to obtain the inorganic fiber composite material.

[0010] Compared to existing technologies, the inorganic fiber composite material provided by this invention uses short-chain dihydroxyl alcohols, dihydroxyl organic acids, and titanium sources as raw materials to prepare a precursor solution. Since the titanium dioxide precursor rapidly hydrolyzes upon contact with water, and the reaction is vigorous and difficult to control, this invention uses a mixed solvent of dihydroxyl organic acid and short-chain dihydroxyl alcohol to inhibit its hydrolysis. The dihydroxyl organic acid and short-chain dihydroxyl alcohol undergo an esterification reaction at high temperature, generating an ester of water and a six-membered ring. The reaction process is slow, and the rate of water generation is also relatively slow, thereby controlling the hydrolysis rate of the titanium source and preventing it from hydrolyzing too quickly to form a gel. After hydrolysis, the titanium source generates Ti(OH)4, which can combine with hydroxyl groups on the surface of inorganic mineral fibers. Through a dehydration condensation reaction, nano-titanium dioxide is generated. The specific reaction process is as follows.

[0011]

[0012] This invention, through extensive research, reveals that existing technologies for loading titanium dioxide onto inorganic mineral fibers primarily rely on physical loading. This involves pretreating the inorganic mineral fibers and then surface-modifying them with a titanium dioxide solution. The surface coating with titanium dioxide increases the contact area with wastewater, compensating for the catalytic degradation limitations of titanium dioxide. However, titanium dioxide is relatively stable, and its physical attachment to the inorganic mineral fiber surface results in an unstable composite material prone to titanium dioxide detachment, significantly impacting catalytic degradation efficiency. To address this challenge, the inventors creatively propose using easily hydrolyzed titanium-containing compounds as the titanium raw material. By limiting hydrolysis with a suitable solvent, the generated titanium dioxide is firmly attached to the inorganic mineral fiber surface through chemical bridging. The two are linked by chemical bonds, resulting in a more stable inorganic fiber composite material with significantly improved catalytic performance. Furthermore, the inorganic fiber composite material provided by this invention requires no pretreatment of the raw materials, is simple to operate, low in cost, and can be repeatedly recycled, conserving resources.

[0013] Preferably, in step one, the short-chain dihydroxy alcohol is ethylene glycol.

[0014] Preferably, in step one, the dibasic organic acid is oxalic acid.

[0015] Preferably, in step one, the titanium source is tetrabutyl titanate.

[0016] Preferably, in step two, the inorganic mineral fiber is basalt fiber.

[0017] In a further preferred embodiment, in step two, the inorganic mineral fiber is basalt fiber cloth.

[0018] Preferably, the mass ratio of short-chain dihydroxy alcohol, dihydroxy organic acid and titanium source in the precursor solution is 66:10:1-6.

[0019] Preferably, the mass ratio of the inorganic mineral fiber to the precursor solution is 1:175-188.

[0020] Preferably, in step two, the temperature of the hydrothermal reaction is 120℃-180℃, and the time of the hydrothermal reaction is 6h-18h.

[0021] Preferably, the washing process involves alternating between 20-30 mL of deionized water and 10 mL-25 mL of anhydrous ethanol for 3-5 washes.

[0022] Preferably, the drying temperature is 60℃-100℃ and the drying time is 20min-30min.

[0023] A second aspect of the present invention provides an inorganic fiber composite material, which is prepared by the method for preparing the inorganic fiber composite material.

[0024] A third aspect of the present invention provides an oil-water separation membrane made of the aforementioned inorganic fiber composite material.

[0025] The inorganic fiber composite material of this invention increases the surface area of ​​titanium dioxide and improves the absorption wavelength range, enabling it to perform photocatalysis under visible light, degrade residual organic pollutants on the membrane surface, restore the membrane's high-efficiency separation performance, and regenerate the oil-water separation membrane. Furthermore, the basalt fiber cloth is flexible, can be folded for storage, occupies a small area, and can be folded for use in environments with high hydraulic pressure, thus improving its pressure resistance.

[0026] Preferably, the contact angle between the surface of the oil-water separation membrane and water is 0°-5°.

[0027] Preferably, the contact angle between the surface of the oil-water separation membrane and the oil is ≥150°.

[0028] The inorganic fiber composite material provided by this invention has special surface wettability of superhydrophilic / underwater superoleophobic. In air, the contact angle of water on the material surface is 0°-5°, reaching a superhydrophilic state; underwater, the contact angle of oil on the material surface is ≥150°, reaching a superoleophobic state.

[0029] Compared with existing technologies, this invention provides a method for preparing and applying an inorganic fiber composite material. Using nano-titanium dioxide as a modifying layer for an oil-water separation membrane and inorganic mineral fibers as the substrate, an oil-water separation membrane with superhydrophilic / underwater superoleophobic surface wettability is constructed. The preparation method of this inorganic fiber composite material is simple and low-cost. The oil-water separation membrane prepared using this composite material has high oil-water separation efficiency. Tests show that the oil-water separation efficiency of the oil-water separation membrane provided by this invention can reach up to 99%. Furthermore, the oil-water separation membrane provided by this invention can be recycled and reused, greatly saving production costs. Attached Figure Description

[0030] Figure 1 Optical photographs of the untreated basalt fiber cloth surface (a) and the sample (b) of Example 1;

[0031] Figure 2 Scanning electron microscope images of the surface of untreated basalt fiber cloth (a) and sample (b) from Example 1;

[0032] Figure 3 X-ray photoelectron spectra of the untreated basalt fiber cloth surface (a) and the sample of Example 1 (b). Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] This embodiment provides an inorganic fiber composite material, the details of which are as follows:

[0036] Step 1: Mix ethylene glycol, oxalic acid and tetrabutyl titanate in a mass ratio of 66:10:5 to obtain a precursor solution.

[0037] Step 2: Mix the basalt fiber cloth and the precursor solution at a mass ratio of 1:180, transfer the mixture to a reaction vessel, and react at 160°C for 12 hours. After the reaction is complete, cool to 25°C, filter, and wash the mixture four times alternately with 20 mL of deionized water and 15 mL of anhydrous ethanol each time. Dry the mixture at 80°C for 25 minutes to obtain the inorganic fiber composite material.

[0038] Example 2

[0039] This embodiment provides an inorganic fiber composite material, the details of which are as follows:

[0040] Step 1: Mix ethylene glycol, oxalic acid and tetrabutyl titanate in a mass ratio of 66:10:6 until homogeneous to obtain a precursor solution;

[0041] Step 2: Mix the basalt fiber cloth and the precursor solution at a mass ratio of 1:182 until homogeneous, then transfer the mixture to a reaction vessel and react at 160°C for 10 hours. After the reaction is complete, cool to 25°C, filter, and wash the mixture 5 times each time with 20 mL of deionized water and 15 mL of anhydrous ethanol. Dry the mixture at 60°C for 30 minutes to obtain the inorganic fiber composite material.

[0042] Example 3

[0043] This embodiment provides an inorganic fiber composite material, the details of which are as follows:

[0044] Step 1: Mix ethylene glycol, oxalic acid and tetrabutyl titanate in a mass ratio of 66:10:1 to obtain a precursor solution.

[0045] Step 2: Mix the basalt fiber cloth and the precursor solution at a mass ratio of 1:188 until homogeneous, then transfer the mixture to a reaction vessel and react at 180°C for 6 hours. After the reaction is complete, cool to 25°C, filter, and wash the mixture 5 times each time with 20 mL of deionized water and 15 mL of anhydrous ethanol. Dry the mixture at 90°C for 20 minutes to obtain the inorganic fiber composite material.

[0046] Example 4

[0047] This embodiment provides an inorganic fiber composite material, the details of which are as follows:

[0048] Step 1: Mix ethylene glycol, oxalic acid and tetrabutyl titanate in a mass ratio of 66:10:2 to obtain a precursor solution.

[0049] Step 2: Mix the basalt fiber cloth and the precursor solution at a mass ratio of 1:175 until homogeneous, then transfer the mixture to a reaction vessel and react at 120°C for 18 hours. After the reaction is complete, cool to 25°C, filter, and wash the mixture 5 times each time with 20 mL of deionized water and 15 mL of anhydrous ethanol. Dry the mixture at 80°C for 20 minutes to obtain the inorganic fiber composite material.

[0050] Comparative Example 1

[0051] This comparative example provides an inorganic fiber composite material, which differs from Example 1 in that oxalic acid is replaced with an equal amount of nitric acid. The specific details are as follows:

[0052] Step 1: Mix ethylene glycol, nitric acid and tetrabutyl titanate in a mass ratio of 66:10:5 to obtain a precursor solution.

[0053] Step 2: Mix the basalt fiber cloth and the precursor solution at a mass ratio of 1:180, transfer the mixture to a reaction vessel, and react at 160°C for 12 hours. After the reaction is complete, cool to 25°C, filter, and wash the mixture four times alternately with 20 mL of deionized water and 15 mL of anhydrous ethanol each time. Dry the mixture at 80°C for 25 minutes to obtain the inorganic fiber composite material.

[0054] Comparative Example 2

[0055] This comparative example provides an inorganic fiber composite material, which differs from Example 1 in that ethylene glycol is replaced with an equal amount of polyvinylpyrrolidone. The specific details are as follows:

[0056] Step 1: Mix polyvinylpyrrolidone, oxalic acid and tetrabutyl titanate in a mass ratio of 66:10:5 to obtain a precursor solution.

[0057] Step 2: Mix the basalt fiber cloth and the precursor solution at a mass ratio of 1:180, transfer the mixture to a reaction vessel, and react at 160°C for 12 hours. After the reaction is complete, cool to 25°C, filter, and wash the mixture four times alternately with 20 mL of deionized water and 15 mL of anhydrous ethanol each time. Dry the mixture at 80°C for 25 minutes to obtain the inorganic fiber composite material.

[0058] Comparative Example 3

[0059] This comparative example provides an inorganic fiber composite material, which differs from Example 1 in that ethylene glycol is replaced with an equal amount of polyvinylpyrrolidone, and oxalic acid is replaced with nitric acid. The specific details are as follows:

[0060] Step 1: Mix polyvinylpyrrolidone, nitric acid and tetrabutyl titanate in a mass ratio of 66:10:5 to obtain a precursor solution.

[0061] Step 2: Mix the basalt fiber cloth and the precursor solution at a mass ratio of 1:180, transfer the mixture to a reaction vessel, and react at 160°C for 12 hours. After the reaction is complete, cool to 25°C, filter, and wash the mixture four times alternately with 20 mL of deionized water and 15 mL of anhydrous ethanol each time. Dry the mixture at 80°C for 25 minutes to obtain the inorganic fiber composite material.

[0062] Comparative Example 4

[0063] This comparative example provides an inorganic fiber composite material, the details of which are as follows:

[0064] Step 1: Add 3g of nano titanium dioxide to 30mL of deionized water and stir for 30min to obtain titanium dioxide gel;

[0065] Step 2: Add 0.3g of short-cut basalt fibers to 10mL of 0.02mol / L sodium hydroxide solution and stir for 30min to obtain a suspension;

[0066] Step 2: Mix the titanium dioxide gel and the suspension evenly, transfer them to a reaction vessel, and react at 150°C for 10 hours. After the reaction is complete, cool to 25°C, filter, and wash 5 times each with 20 mL of deionized water and 15 mL of anhydrous ethanol. Dry at 80°C for 20 minutes to obtain the inorganic fiber composite material.

[0067] To further demonstrate that the inorganic fiber composite material provided by the present invention can be used for oil-water separation, the inorganic fiber composite materials provided in Examples 1-4 and Comparative Examples 1-4 were immersed in deionized water for 3 minutes, cut to obtain an oil-water separation membrane, and the performance of the obtained oil-water separation membrane was tested. The specific contents are as follows.

[0068] The specific procedures for oil-water separation testing are as follows:

[0069] Step 1: Mix deionized water and n-hexadecane in a volume ratio of 1:1 until homogeneous to obtain an oil-water mixture;

[0070] Step 2: Pass the oil-water mixture through an oil-water separation membrane from top to bottom to obtain separated water and oil.

[0071] According to the formula for calculating oil-water separation efficiency, η = (m a / m b ) × 100%, where η represents the oil-water separation efficiency, m a and m b The values ​​are the mass of the oil-water separation membranes after and before hexadecane separation, respectively. The separation efficiency of the oil-water separation membranes obtained in each example and comparative example was calculated, and the calculation results are shown in Table 1.

[0072] Table 1. Test results of the separation efficiency of the oil-water separation membranes obtained in each embodiment and comparative example.

[0073]

[0074] As can be seen from Table 1, the oil-water separation membrane provided by the present invention has a high separation efficiency of over 99%. When the oil-water mixture passes through the oil-water separation membrane of the present invention, the water passes smoothly through the oil-water separation membrane and flows out from below, while the oil is blocked above the oil-water separation membrane. It can be seen that the oil-water separation membrane provided by the present invention has special surface wettability of superhydrophilic / underwater superoleophobic.

[0075] To verify whether the surface of the basalt fiber cloth was loaded with nano-titanium dioxide, the present invention also conducted scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis. The results are as follows: Figure 1 , Figure 2 and Figure 3 As shown.

[0076] According to the appendix Figure 1 It can be seen that, compared with the untreated basalt fiber cloth, the sample provided in Example 1 of the present invention has obvious titanium dioxide particles on the basalt fiber cloth; while in the scanning electron microscope image ( Figure 2 In the experiment, after magnifying the untreated basalt fiber cloth and the sample obtained in Example 1 by 10,000 times, it can be seen that the surface of the untreated basalt fiber is smooth, while the surface of the basalt fiber of the sample obtained in Example 1 of this invention is covered with nano-titanium dioxide, and granular titanium dioxide appears on the surface. According to the XPS image, the characteristic peaks of Ti and O elements are significantly enhanced, which further illustrates that titanium dioxide is loaded onto the surface of the basalt fiber cloth.

[0077] 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 or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an inorganic fiber composite material, characterized in that: It should include at least the following steps: Step 1: Mix the short-chain dihydroxy alcohol, dihydroxy organic acid and titanium source evenly to obtain a precursor solution; Step 2: After uniformly mixing the inorganic mineral fibers and the precursor solution, perform a hydrothermal reaction, filter, wash, and dry to obtain the inorganic fiber composite material; in Step 1, the short-chain difatty alcohol is ethylene glycol; In step one, the dibasic organic acid is oxalic acid; In step one, the titanium source is tetrabutyl titanate; In step two, the inorganic mineral fiber is basalt fiber.

2. The method for preparing the inorganic fiber composite material as described in claim 1, characterized in that: The mass ratio of short-chain dihydroxy alcohol, dihydroxy organic acid and titanium source in the precursor solution is 66:10:1-6.

3. The method for preparing the inorganic fiber composite material as described in claim 1, characterized in that: The mass ratio of the inorganic mineral fiber to the precursor solution is 1:175-188.

4. The method for preparing the inorganic fiber composite material as described in claim 1, characterized in that: In step two, the temperature of the hydrothermal reaction is 120℃-180℃, and the reaction time is 6h-18h.

5. The method for preparing the inorganic fiber composite material as described in claim 1, characterized in that: In step two, the drying temperature is 60℃-100℃, and the drying time is 20min-30min.

6. An inorganic fiber composite material, characterized in that: It is prepared by the method of any one of claims 1-5 for preparing inorganic fiber composite materials.

7. An oil-water separation membrane, characterized in that: Made from the inorganic fiber composite material as described in claim 6.

8. The oil-water separation membrane as described in claim 7, characterized in that: The contact angle between the surface of the oil-water separation membrane and water is 0°-5°; and / or The contact angle between the surface of the oil-water separation membrane and the oil is ≥150°.

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