A hydrated calcium silicate-glass fiber composite material and its preparation method

Abstract

This application discloses a hydrated calcium silicate-glass fiber composite material and its preparation method. The preparation method includes: firstly, calcining alkali-free waste glass fiber at high temperature, followed by ultrasonication, washing, and drying to obtain single glass fibers with the surface wetting agent removed; then, reacting the single glass fibers in an alkaline solution to obtain a crude hydrated calcium silicate-glass fiber composite material; finally, subjecting the crude hydrated calcium silicate-glass fiber composite material to ultrasonication, washing, and drying to obtain the final hydrated calcium silicate-glass fiber composite material. This composite material can effectively adsorb dyes from wastewater and is easy to recycle, simultaneously solving the problems of land pollution from waste glass fiber and water pollution from dyes.

Description

Technical Field

[0001] This application belongs to the field of glass fiber technology, specifically relating to a hydrated calcium silicate-glass fiber composite material and its preparation method. Background Technology

[0002] With the rapid development of society and the economy, water pollution is also intensifying. Water is an essential component for biological life, yet only 0.007% of water is drinkable. Currently, with the rapid development of the textile, paper, and other chemical industries, the discharge of dye wastewater is also increasing rapidly. At present, the world produces as many as 10,000 types of dyes, with an annual production exceeding 700,000 tons. However, during their use and consumption, more than 10% of these dyes are discharged into water bodies without being fully utilized, causing very serious water pollution. For example, methylene blue, a common dye, dissolves in water to form a blue alkaline solution. Excessive intake can oxidize hemoglobin, forming methemoglobin, causing adverse reactions such as nausea, abdominal pain, precordial pain, dizziness, and headache. Therefore, removing dyes (such as methylene blue dye) from water is crucial for environmental protection and human health. Traditional treatment methods are not widely used due to problems such as incomplete removal, difficulty in recycling, secondary pollution, and lack of reusability. Adsorption, as a low-cost, simple-to-operate method that can simultaneously adsorb different pollutants, has been widely applied in wastewater treatment. This method removes pollutants by concentrating them into the pores of an adsorbent through physical or chemical adsorption. However, the adsorbent often presents difficulties in recovery.

[0003] Waste fiberglass filaments, an unavoidable byproduct of the production and reinforcement processes, can cause soil pollution if buried deep underground. Remelting them in a furnace presents problems such as cumbersome procedures and high production costs. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application provides a hydrated calcium silicate-glass fiber composite material and its preparation method. This application utilizes an in-situ conversion method to partially convert waste glass fiber filaments into hydrated calcium silicate, thereby transforming the waste glass fiber filaments into a hydrated calcium silicate-glass fiber composite material. This composite material leverages the strong adsorption properties of hydrated calcium silicate to adsorb dyes from water, while simultaneously utilizing the excellent mechanical properties of glass fibers to recover the hydrated calcium silicate-glass fiber composite material. This approach can simultaneously solve the problems of land pollution from waste glass fiber filaments and water pollution from dyes.

[0005] According to a first aspect of this application, a method for preparing a hydrated calcium silicate-glass fiber composite material is provided, comprising:

[0006] Step 1S: At the first temperature, the waste glass fiber is calcined for a first time, then ultrasonicated at the first ultrasonic frequency for a second time, and after washing and drying, a single glass fiber with the surface wetting agent removed is obtained.

[0007] Step 2S: Place a single glass fiber in an alkaline solution. The single glass fiber and the alkaline solution react at a second temperature for a third time to generate sheet-like hydrated calcium silicate, thus obtaining a crude product of hydrated calcium silicate-glass fiber composite material.

[0008] Step 3S: The crude hydrated calcium silicate-glass fiber composite material is ultrasonicated at the second ultrasonic frequency for a fourth duration, then rinsed with deionized water and ethanol, and then dried in an oven to obtain the hydrated calcium silicate-glass fiber composite material.

[0009] Preferably, in step 1S, the first temperature is 500℃-700℃ and the first duration is 1-8h.

[0010] Preferably, in step 1S, the first ultrasonic frequency is 60-100Hz and the second duration is 5-20min.

[0011] Preferably, in step 2S, the alkaline solution is an aqueous NaOH solution, and the mass percentage concentration of the aqueous NaOH solution is 5%-50%.

[0012] Preferably, in step 2S, the second temperature is 80℃-140℃, and the third duration is 1-36h.

[0013] Preferably, in step 2S, the mass ratio of a single glass fiber to an alkaline solution is 0.01:1 to 0.3:1.

[0014] Preferably, in step 3S, the second ultrasonic frequency is 30-60Hz and the fourth duration is 1-5min.

[0015] Preferably, in step 3S, the oven temperature is 60℃-100℃ and the drying time is 8-20h.

[0016] Preferably, the reaction equations for the single glass fiber reacting with the alkaline solution at a second temperature for a third time to produce sheet-like hydrated calcium silicate include formulas (I) and (II).

[0017] SiO2 + 2OH - →[SiO2(OH)2] 2- Equation (Ⅰ);

[0018] 2[SiO2(OH)2] 2- +5Ca 2+ +6OH -→Ca5(SiO4)2(OH)2↓+4H2O (Formula II).

[0019] According to a second aspect of this application, a hydrated calcium silicate-glass fiber composite material prepared by the above-described method for preparing hydrated calcium silicate-glass fiber composite material is provided.

[0020] This application utilizes an in-situ conversion method to transform alkali-free waste glass fiber into hydrated calcium silicate-glass fiber composite material. The process is simple, low-cost, and suitable for industrial production. Furthermore, the resulting sheet-like hydrated calcium silicate has a large specific surface area, and the remaining glass fibers possess good mechanical properties, facilitating easy handling and recycling. Therefore, this application simultaneously solves the problems of large amounts of waste fiber and water pollution from dyes generated during both glass fiber production and reinforcing material production. Attached Figure Description

[0021] The accompanying drawings, incorporated herein by reference, illustrate embodiments of the present application and, together with the textual description, serve to explain these embodiments. In these drawings, similar reference numerals are used to denote similar elements. The drawings described below are some embodiments of the present application, but not all embodiments. Other drawings will be readily apparent to those skilled in the art from these drawings without inventive effort.

[0022] Figure 1 SEM image of a single glass fiber and hydrated calcium silicate-glass fiber composite material according to an exemplary embodiment.

[0023] Figure 2 The image shows the XRD pattern of a hydrated calcium silicate-glass fiber composite material according to an exemplary embodiment.

[0024] Figure 3 The images show a comparison of methylene blue adsorption before and after on a hydrated calcium silicate-glass fiber composite material according to an exemplary embodiment.

[0025] Figure 4 This is a graph showing the relationship between the adsorption time and the methylene blue concentration of a hydrated calcium silicate-glass fiber composite material according to an exemplary embodiment. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0027] In some optional embodiments, a method for preparing a hydrated calcium silicate-glass fiber composite material is provided, comprising:

[0028] Step 1S: At the first temperature, the waste glass fiber is calcined for a first time, then ultrasonicated at the first ultrasonic frequency for a second time, and after washing and drying, a single glass fiber with the surface wetting agent removed is obtained.

[0029] Step 2S: Place a single glass fiber in an alkaline solution. The single glass fiber and the alkaline solution react at a second temperature for a third time to generate sheet-like hydrated calcium silicate, thus obtaining a crude product of hydrated calcium silicate-glass fiber composite material.

[0030] Step 3S: The crude hydrated calcium silicate-glass fiber composite material is ultrasonicated at the second ultrasonic frequency for a fourth duration, then rinsed with deionized water and ethanol, and then dried in an oven to obtain the hydrated calcium silicate-glass fiber composite material.

[0031] This application utilizes an in-situ conversion method to partially convert waste glass fiber into hydrated calcium silicate on its surface, thereby transforming the waste glass fiber into a hydrated calcium silicate-glass fiber composite material. The hydrated calcium silicate-glass fiber composite material utilizes the strong adsorption properties of hydrated calcium silicate to adsorb dyes in water, while simultaneously recovering the glass fiber through the excellent mechanical properties of glass fiber. This approach can simultaneously solve the problems of land pollution from waste glass fiber and water pollution from dyes.

[0032] In some optional embodiments, in step 1S, the first temperature is 500℃-700℃, and the first duration is 1-8h. In other optional embodiments, the first temperature is 600℃-650℃, and the first duration is 1-2h.

[0033] In some optional embodiments, in step 1S, the first ultrasonic frequency is 60-100Hz, and the second duration is 5-20min. In other optional embodiments, the first ultrasonic frequency is 70-80Hz, and the second duration is 5-8min.

[0034] In some optional embodiments, in step 2S, the alkaline solution is an aqueous NaOH solution with a mass percentage concentration of 5%-50%. In other optional embodiments, the mass percentage concentration of the aqueous NaOH solution is 20%-30%.

[0035] In some optional embodiments, in step 2S, the second temperature is 80°C-140°C, and the third duration is 1-36 hours. In other optional embodiments, the second temperature is 120°C-140°C, and the third duration is 2-4 hours.

[0036] In some optional embodiments, in step 2S, the mass ratio of the single glass fiber to the alkaline solution is 0.01:1 to 0.3:1. In other optional embodiments, the mass ratio of the single glass fiber to the alkaline solution is 0.04:1 to 0.15:1.

[0037] In some optional embodiments, in step 3S, the second ultrasonic frequency is 30-60 Hz, and the fourth duration is 1-5 min. In other optional embodiments, the second ultrasonic frequency is 30-40 Hz, and the fourth duration is 1-2 min.

[0038] In some optional embodiments, in step 3S, the oven temperature is 60℃-100℃ and the drying time is 8-20h. In other optional embodiments, in step 3S, the oven temperature is 80℃-100℃ and the drying time is 8-10h.

[0039] In some optional embodiments, in step 3S, the washing is performed 3-5 times with deionized water and 3-5 times with ethanol.

[0040] In some optional embodiments, the reaction equations for the single glass fiber reacting with the alkaline solution at a second temperature for a third time to produce sheet-like hydrated calcium silicate include equations (I) and (II).

[0041] SiO2 + 2OH - →[SiO2(OH)2] 2- Equation (Ⅰ);

[0042] 2[SiO2(OH)2] 2- +5Ca 2+ +6OH - →Ca5(SiO4)2(OH)2↓+4H2O (Formula II).

[0043] In this application, the alkaline solution contains a large amount of OH-. - It will break the ≡Si-O-Si≡ bonds in the glass structure, forming [SiO2(OH)2]. 2-Because the reaction takes place in a high-temperature, high-pressure, and high-concentration environment, a large amount of [SiO2(OH)2] is produced. 2- It will transfer into the solution. Furthermore, because typical alkali-free glass contains a large amount of CaO (≥20%), after the structure is destroyed, the CaO... 2+ It precipitates from the structure and reacts with [SiO2(OH)2] in the solution. 2- The reaction produces hydrated calcium silicate. Due to the slow ion precipitation process, the reaction occurs in situ on the glass fiber surface. Furthermore, the resulting crystals continue to grow in a high-temperature, high-pressure reactor, eventually forming sheet-like hydrated calcium silicate.

[0044] In some optional embodiments, a hydrated calcium silicate-glass fiber composite material prepared by the above-described method for preparing hydrated calcium silicate-glass fiber composite material is provided.

[0045] To further illustrate the beneficial effects of the hydrated calcium silicate-glass fiber composite material and its preparation method of this application, some specific embodiments of the preparation method of the hydrated calcium silicate-glass fiber composite material of this application are listed below.

[0046] Example 1

[0047] Take 5g of waste glass fiber and place it in a muffle furnace at 650℃ for calcination treatment for 1 hour. After cooling, place it in an ultrasonic cleaner and sonicate it at 80Hz for 5 minutes. After rinsing with deionized water, dry it in an oven to obtain single glass fiber with the surface wetting agent removed.

[0048] Prepare 100 mL of 20% NaOH aqueous solution and pour it into a 300 mL reaction vessel. Place a single glass fiber in the reaction vessel and react the single glass fiber with the NaOH aqueous solution at 130 °C for 3 h to generate sheet-like hydrated calcium silicate, thus obtaining crude hydrated calcium silicate-glass fiber composite material; wherein the mass ratio of single glass fiber to NaOH aqueous solution is 0.04:1.

[0049] The crude product of hydrated calcium silicate-glass fiber composite material was placed in an ultrasonic cleaner and ultrasonicated at 30 Hz for 1 min. It was then rinsed three times with deionized water and three times with alcohol, and finally dried in an oven at 90 ℃ for 8 h to obtain the hydrated calcium silicate-glass fiber composite material.

[0050] Example 2

[0051] Take 15g of waste glass fiber and place it in a muffle furnace at 600℃ for calcination treatment for 1.5h. After cooling, put it in an ultrasonic cleaner and sonicate it at 100Hz for 8min. After rinsing with deionized water, dry it in an oven to obtain single glass fiber with the surface wetting agent removed.

[0052] Prepare 100 mL of 25% NaOH aqueous solution and pour it into a 300 mL reaction vessel. Place a single glass fiber in the reaction vessel and allow the single glass fiber to react with the NaOH aqueous solution at 140℃ for 2 hours to generate sheet-like hydrated calcium silicate, thus obtaining crude hydrated calcium silicate-glass fiber composite material; wherein the mass ratio of single glass fiber to NaOH aqueous solution is 0.12:1.

[0053] The crude product of hydrated calcium silicate-glass fiber composite material was placed in an ultrasonic cleaner and ultrasonicated at 40 Hz for 1 min. It was then rinsed three times with deionized water and three times with alcohol, and finally dried in an oven at 80 ℃ for 10 h to obtain the hydrated calcium silicate-glass fiber composite material.

[0054] Example 3

[0055] Take 10g of waste glass fiber and place it in a muffle furnace at 600℃ for calcination treatment for 2 hours. After cooling, put it into an ultrasonic cleaner and sonicate it at 80Hz for 10 minutes. After rinsing with deionized water, dry it in an oven to obtain single glass fiber with the surface wetting agent removed.

[0056] Prepare 100 mL of 30% NaOH aqueous solution and pour it into a 300 mL reaction vessel. Place a single glass fiber in the reaction vessel and allow the single glass fiber to react with the NaOH aqueous solution at 135℃ for 2 hours to generate sheet-like hydrated calcium silicate, thus obtaining crude hydrated calcium silicate-glass fiber composite material; wherein the mass ratio of single glass fiber to NaOH aqueous solution is 0.07:1.

[0057] The crude product of hydrated calcium silicate-glass fiber composite material was placed in an ultrasonic cleaner and ultrasonicated at 40 Hz for 1 min. It was then rinsed three times with deionized water and three times with alcohol, and finally dried in an oven at 80 ℃ for 10 h to obtain the hydrated calcium silicate-glass fiber composite material.

[0058] Example 4

[0059] 12g of waste glass fiber was placed in a muffle furnace at 550℃ for calcination for 5h. After cooling, it was placed in an ultrasonic cleaner and ultrasonicated at 60Hz for 5min. After rinsing with deionized water, it was dried in an oven to obtain single glass fiber with the surface wetting agent removed.

[0060] Prepare 100 mL of 50% NaOH aqueous solution and pour it into a 300 mL reaction vessel. Place a single glass fiber in the reaction vessel and react the single glass fiber with the NaOH aqueous solution at 110 °C for 4 h to generate sheet-like hydrated calcium silicate, thus obtaining crude hydrated calcium silicate-glass fiber composite material; wherein the mass ratio of single glass fiber to NaOH aqueous solution is 0.08:1.

[0061] The crude product of hydrated calcium silicate-glass fiber composite material was placed in an ultrasonic cleaner and ultrasonicated at 35 Hz for 3 min. It was then rinsed 3 times with deionized water and 3 times with alcohol, and finally dried in an oven at 85 ℃ for 14 h to obtain the hydrated calcium silicate-glass fiber composite material.

[0062] Example 5

[0063] Take 10g of waste glass fiber and place it in a muffle furnace at 700℃ for calcination treatment for 1 hour. After cooling, place it in an ultrasonic cleaner and sonicate it at 100Hz for 8 minutes. After rinsing with deionized water, dry it in an oven to obtain single glass fiber with the surface wetting agent removed.

[0064] Prepare 100 mL of 40% NaOH aqueous solution and pour it into a 300 mL reaction vessel. Place a single glass fiber in the reaction vessel and allow the single glass fiber to react with the NaOH aqueous solution at 120℃ for 5 h to generate sheet-like hydrated calcium silicate, thus obtaining crude hydrated calcium silicate-glass fiber composite material; wherein the mass ratio of single glass fiber to NaOH aqueous solution is 0.07:1.

[0065] The crude product of hydrated calcium silicate-glass fiber composite material was placed in an ultrasonic cleaner and ultrasonicated at 60 Hz for 1.5 min. It was then rinsed three times with deionized water and three times with alcohol, and finally dried in an oven at 70 ℃ for 20 h to obtain the hydrated calcium silicate-glass fiber composite material.

[0066] Example 6

[0067] Take 10g of waste glass fiber and place it in a muffle furnace at 620℃ for calcination treatment for 4 hours. After cooling, put it into an ultrasonic cleaner and sonicate it at 90Hz for 15 minutes. After rinsing with deionized water, dry it in an oven to obtain single glass fiber with the surface wetting agent removed.

[0068] Prepare 100 mL of 10% NaOH aqueous solution and pour it into a 300 mL reaction vessel. Place a single glass fiber in the reaction vessel and allow the single glass fiber to react with the NaOH aqueous solution at 80℃ for 30 h to generate sheet-like hydrated calcium silicate, thus obtaining crude hydrated calcium silicate-glass fiber composite material; wherein the mass ratio of single glass fiber to NaOH aqueous solution is 0.09:1.

[0069] The crude product of hydrated calcium silicate-glass fiber composite material was placed in an ultrasonic cleaner and ultrasonicated at 50 Hz for 2 min. It was then rinsed 3 times with deionized water and 3 times with alcohol, and finally dried in an oven at 100 ℃ for 11 h to obtain the hydrated calcium silicate-glass fiber composite material.

[0070] This application used scanning electron microscopy (SEM) to scan the single glass fiber and the hydrated calcium silicate-glass fiber composite material in Example 1, and the SEM images are shown below. Figure 1 As shown; where, Figure 1 Figure (a) is a SEM image of a single glass fiber in Example 1. Figure 1 Figure (b) is a SEM image of the hydrated calcium silicate-glass fiber composite material in Example 1. According to... Figure 1 It is known that a single glass fiber has a smooth surface, but when a single glass fiber is placed in an aqueous solution of NaOH, the surface part of the glass fiber reacts with NaOH to form sheet-like hydrated calcium silicate, and the surface of the resulting hydrated calcium silicate-glass fiber composite material is not smooth.

[0071] This application utilizes X-ray diffraction (XRD) technology to analyze the hydrated calcium silicate-glass fiber composite material in Example 1, and its XRD pattern is shown below. Figure 2 As shown, Figure 2 In the diagram, the vertical axis represents intensity, and the horizontal axis represents the angle scanned by the diffractometer. Analysis Figure 2 It can be seen that the diffraction peaks of the composite material in Example 1 are in the same position as the diffraction peaks of hydrated calcium silicate, confirming the formation of hydrated calcium silicate.

[0072] In this application, the hydrated calcium silicate-glass fiber composite material of Example 1 is placed in a solution containing methylene blue. Figure 3 Figure (a) shows a photograph of the hydrated calcium silicate-glass fiber composite material before it was placed in a methylene blue solution. At this time, the hydrated calcium silicate-glass fiber composite material is milky white. Figure 3 Image (b) shows a photograph of the hydrated calcium silicate-glass fiber composite material after it has been immersed in a methylene blue solution for 2 hours and then dried. At this point, the hydrated calcium silicate-glass fiber composite material is blue. Figure 3 It can be seen that the hydrated calcium silicate-glass fiber composite material of Example 1 has a strong adsorption capacity for methylene blue.

[0073] In this application, the hydrated calcium silicate-glass fiber composite material of Example 1 is placed in a solution containing methylene blue. Figure 4 The concentration of methylene blue in the solution changes at different adsorption times. Figure 4 In the graph, the horizontal axis represents adsorption time, and the vertical axis represents the ratio of the current concentration of methylene blue in the solution to its original concentration. As the adsorption time increases, the concentration of methylene blue in the solution decreases. When the adsorption time is greater than or equal to 210 min, the ratio of the current concentration of methylene blue in the solution to its original concentration is less than or equal to 0.17.

Claims

1. A method for preparing a hydrated calcium silicate-glass fiber composite material, characterized in that, include: Step 1S: At the first temperature, the waste glass fiber is calcined for a first time, then ultrasonicated at the first ultrasonic frequency for a second time, and after washing and drying, a single glass fiber with the surface wetting agent removed is obtained. Step 2S: Place a single glass fiber in an alkaline solution, and react the single glass fiber with the alkaline solution at a second temperature for a third time to generate sheet-like hydrated calcium silicate on the surface of the single glass fiber, thereby obtaining a crude product of hydrated calcium silicate-glass fiber composite material. Step 3S: The crude product of hydrated calcium silicate-glass fiber composite material is ultrasonicated at the second ultrasonic frequency for a fourth duration, then rinsed with deionized water and ethanol, and then dried in an oven to obtain hydrated calcium silicate-glass fiber composite material. The glass fiber waste filaments are alkali-free glass fiber waste filaments; In step 2S, the alkaline solution is an aqueous NaOH solution with a mass percentage concentration of 20%-50%; the second temperature is 110℃-140℃.

2. The method for preparing the hydrated calcium silicate-glass fiber composite material according to claim 1, characterized in that, In step 1S, the first temperature is 500℃-700℃ and the first duration is 1-8 h.

3. The method for preparing the hydrated calcium silicate-glass fiber composite material according to claim 1, characterized in that, In step 1S, the first ultrasonic frequency is 60-100kHz, and the second duration is 5-20 min.

4. The method for preparing the hydrated calcium silicate-glass fiber composite material according to claim 1, characterized in that, In step 2S, the third duration is 1-36 h.

5. The method for preparing the hydrated calcium silicate-glass fiber composite material according to claim 1, characterized in that, In step 2S, the mass ratio of a single glass fiber to an alkaline solution is 0.01:1 to 0.3:

1.

6. The method for preparing the hydrated calcium silicate-glass fiber composite material according to claim 1, characterized in that, In step 3S, the second ultrasonic frequency is 30-60kHz, and the fourth duration is 1-5 min.

7. The method for preparing the hydrated calcium silicate-glass fiber composite material according to claim 1, characterized in that, In step 3S, the oven temperature is 60℃-100℃ and the drying time is 8-20 h.

8. A hydrated calcium silicate-glass fiber composite material, characterized in that, It is prepared by the method for preparing hydrated calcium silicate-glass fiber composite material according to any one of claims 1-7.

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