Preparation method of environment-friendly nano silica sol-based hydrophobic cold aerosol explosion suppressant

Abstract

The invention discloses a preparation method of an environment-friendly nano silica sol-based hydrophobic cold aerosol explosion suppressant, and belongs to the technical field of explosion suppressant preparation. The preparation method comprises the following steps: S1, uniformly mixing nano silica sol, a functional modifier, a solvent and a catalyst to obtain a mixed solution A; s2, uniformly mixing the superfine fire extinguishing base material dispersion liquid and an initiator to obtain a mixed solution B; s3, uniformly mixing the mixed solution A and the mixed solution B, carrying out water bath heating reaction, and then sequentially filtering, washing and drying to obtain the environment-friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant. The problems that existing cold aerosol is prone to moisture absorption and caking and poor in fluidity are solved, the inhibition efficiency of the fire explosion inhibitor is improved, and explosion suppression of combustible gas under complex working conditions is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of explosion suppressant preparation, and particularly relates to a method for preparing an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant. Background Art

[0002] Nano cold aerosol explosion suppressants, with their tiny particle size, offer a new approach to gas explosion suppression. However, their extremely high surface area and surface energy can easily lead to particle agglomeration, resulting in a decrease in surface area and a reduction in key properties such as dispersion, fluidity, and diffusivity, significantly weakening their explosion suppression effectiveness.

[0003] Existing stability control technologies are mainly divided into two categories: physical interference and surface modification. The former inhibits agglomeration through external forces such as dry dispersion, mechanical dispersion or electrostatic dispersion, but has inherent defects of limited intensity and insufficient timeliness. The latter weakens the van der Waals force between particles at the microscopic level by regulating the physical and chemical properties of the powder surface such as wettability and charge state, thereby achieving long-term and stable dispersion control. Although the introduction of hydrophobic groups can effectively enhance the moisture absorption resistance of cold aerosol explosion suppressants and improve the fluidity of the powder, the surface energy of the material is limited, and the number of active sites available for reaction restricts the loading amount of the modifier. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for preparing an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant. The present invention solves the problems of the existing cold aerosol being easy to absorb moisture and agglomerate and having poor fluidity, improves the suppression efficiency of the explosion suppressant, and realizes the explosion suppression of combustible gas under complex working conditions.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant, comprising the following steps:

[0007] S1. The nano-silica sol, functional modifier, solvent, and catalyst are mixed to obtain a mixed solution A;

[0008] S2. The ultrafine fire extinguishing base dispersion, the initiator is mixed to obtain a mixture B;

[0009] S3. Mix the mixed solution A and the mixed solution B evenly and heat them in a water bath for reaction. Then, filter, wash and dry them in sequence to obtain an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant.

[0010] Preferably, the mass ratio of the nano-silica sol, functional modifier, solvent and catalyst in S1 is (5-15):(1-5):(20-60):(0.1-4).

[0011] Preferably, the nano-silica sol is acidic nano-silica sol; the particle size of the nano-silica sol is 1 to 500 nm.

[0012] Preferably, the acidic nano-silica sol is prepared from one or more of ethyl orthosilicate, tetramethoxysilane, methyltriethoxysilane, ethyl silicate 28, ethyl silicate 32, ethyl silicate 40, tetramethylsilane, tetraethylsilane, and polydimethylsiloxane; more preferably, ethyl orthosilicate.

[0013] Preferably, the functional modifier in S1 is one or more of nine-carbon perfluoropolyether siloxane, tridecafluorooctyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropylmethyldimethoxysilane, trifluoropropyltriethoxysilane, tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, and heptadecafluorodecyltriethoxysilane; more preferably, nine-carbon perfluoropolyether siloxane.

[0014] More preferably, the solvent in S1 is one or more of ethanol, methanol, and acetone; more preferably, it is ethanol.

[0015] Preferably, the catalyst in S1 is at least one of hydrochloric acid, acetic acid, sulfuric acid, nitric acid, phosphoric acid, and formic acid; more preferably, hydrochloric acid.

[0016] Preferably, the mixing temperature in S1 is 0-60° C. and the mixing time is 2-6 hours.

[0017] More preferably, the mixing and stirring speed is 200-400 r / min.

[0018] Preferably, the mass concentration of the ultrafine fire extinguishing base dispersion in S2 is 10-50%; and the initiator accounts for 0.5-5% of the mass of the solution.

[0019] Preferably, the ultrafine fire extinguishing base material in the ultrafine fire extinguishing base material dispersion is bicarbonate, carbonate, or phosphate, and the particle size of the ultrafine fire extinguishing base material is less than 10 μm.

[0020] Preferably, the initiator is one of aqueous ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, tetramethylammonium hydroxide or triethylamine; more preferably aqueous ammonia.

[0021] Preferably, the volume ratio of the mixed liquid A to the mixed liquid B in S3 is 1:3.

[0022] More preferably, the stirring speed in S3 is 2000 r / min.

[0023] More preferably, the water bath heating reaction temperature in S3 is 50-60° C. and the time is 2-6 h.

[0024] Contains at least the following beneficial technical effects:

[0025] The present invention discovered that the nano-scale particle size of silica sol can serve as an ideal platform for loading functional groups. The rich silanol groups on its surface can undergo a directional condensation reaction with various silane coupling agents; the sol-gel properties can achieve micro-nanoscale coating modification; these properties make silica sol a key carrier for constructing "core-shell" structured functional explosion suppressants, providing a new path to break through the bottleneck of existing technologies.

[0026] The present invention uses the bridging effect of nano-silica sol to break through the limitation of insufficient active sites on the surface of traditional substrates and achieve a significant increase in the loading amount of the modifier; at the same time, combined with the large-scale introduction of fluorine-based functional groups, the cold aerosol explosion suppressant has excellent hydrophobicity, fluidity and targeted inhibition ability for gas explosion free radical chain reactions. This synergistic mechanism provides a solution for efficient explosion suppression of combustible gas explosions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flow chart of the preparation method of Example 1.

[0028] Figure 2 This is an electron microscope image of the product obtained in Example 1.

[0029] Figure 3 This is an electron microscope image of the product obtained in Example 2.

[0030] Figure 4 This is a particle size classification diagram of powders with different modification concentrations.

[0031] Figure 5 This is the X-ray photoelectron spectrum of the product obtained in Example 1.

[0032] Figure 6 This is the thermogravimetric curve of the product obtained in Example 1.

[0033] Figure 7 This is the explosion suppression effect diagram of the product obtained in Example 1.

[0034] Figure 8 This is a hydrophobicity test chart of environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant with different modifier dosages. DETAILED DESCRIPTION

[0035] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0036] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0037] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0038] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the present invention. The present description and examples are intended to be illustrative only.

[0039] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0040] Unless otherwise specified, the "room temperature" and "normal temperature" mentioned in the present invention are all calculated as 25±2°C.

[0041] Unless otherwise specified, all raw materials and instruments used in the following examples of the present invention are commercially available.

[0042] The commercially available nano-acidic silica sol can be used.

[0043] Example 1

[0044] This embodiment provides a method for preparing an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant:

[0045] S1. 10 ml of nano-acidic silica sol and 2.4 g of nine-carbon perfluoropolyether siloxane were added to 40 ml of ethanol, 1 ml of hydrochloric acid was added dropwise to the solution, and the mixture was stirred in a water bath at 300 r / min and 50°C for 2 h to obtain a mixed solution A;

[0046] S2. 30 g of ultrafine potassium bicarbonate (particle size 6 μm) was added to 150 ml of ethanol solution, and 2 ml of aqueous ammonia was added dropwise to the solution to obtain a mixed solution B;

[0047] S3. Add the mixed solution A dropwise to the mixed solution B and react at a stirring speed of 2000 r / min and 50°C for 6 h. After the reaction is completed, filter out the powder in the reaction solution, rinse it three times with anhydrous ethanol, dry it at 60°C under normal pressure, and then sieve it to obtain an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant with an 8% modifier dosage.

[0048] Example 2

[0049] The preparation method of this embodiment is the same as that of Example 1 except that the amount of nine-carbon perfluoropolyether siloxane used in step S1 is 4.8 g.

[0050] Example 3

[0051] This embodiment provides a method for preparing an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant:

[0052] S1. 2.4 ml of nano-acidic silica sol and 2.4 g of tridecafluorooctyltriethoxysilane were added to 20 ml of ethanol, 0.5 ml of sulfuric acid was added dropwise to the solution, and stirred in a water bath at a speed of 200-400 r / min and 55 ° C for 4 h to obtain a mixed solution A;

[0053] S2. 30 g of ultrafine potassium bicarbonate (particle size 10 μm) was added to 300 ml of ethanol solution, and 5 ml of sodium hydroxide was added dropwise to the solution to obtain a mixed solution B;

[0054] S3. Add the mixed solution A dropwise to the mixed solution B and react at a stirring speed of 2000 r / min and 55°C for 4 h. After the reaction is completed, filter out the powder in the reaction solution, rinse it three times with anhydrous ethanol, dry it at 60°C under normal pressure, and then sieve it to obtain an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant with an 8% modifier dosage.

[0055] Example 4

[0056] This embodiment provides a method for preparing an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant:

[0057] S1. 30 ml of nano-acidic silica sol and 2.4 g of 3,3,3-trifluoropropyltrimethoxysilane were added to 60 ml of ethanol, 3 ml of nitric acid was added dropwise to the solution, and stirred in a water bath at 200-400 r / min and 60 ° C for 6 h to obtain a mixed solution A;

[0058] S2. 30 g of ultrafine potassium bicarbonate (particle size 10 μm) was added to 100 ml of ethanol solution, and 2 ml of sodium carbonate was added dropwise to the solution to obtain a mixed solution B;

[0059] S3. Add the mixed solution A dropwise to the mixed solution B and react at a stirring speed of 2000 r / min and 50°C for 2 h. After the reaction is completed, filter out the powder in the reaction solution, rinse it three times with anhydrous ethanol, dry it at 60°C under normal pressure, and then sieve it to obtain an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant with an 8% modifier dosage.

[0060] Experimental Example 1

[0061] The products obtained in Example 1-2 were tested for performance using the following method:

[0062] Scanning electron microscopy (SEM, Zeiss Sigma 300) was used to study the microstructure of the sample surface, and an ultra-high-speed intelligent particle size analyzer (Mastersize 3000) was used to measure the particle size (0.01-3500 μm).

[0063] FTIR spectra were evaluated using a Thermo Fisher Nicolet iS50 Fourier transform spectrometer in the wavenumber range of 500–4000 cm -1 .

[0064] The surface chemical composition of the powder was characterized and analyzed using a Thermo Scientific K-Alpha X-ray photoelectron spectrometer (XPS) at a magnification of 250 times.

[0065] Thermogravimetric analysis (TGA) curves of the powders were drawn using a thermogravimetric mass spectrometer (STA-449F5) in a nitrogen environment (50-600°C, 10°C / min), and the evolved gases were analyzed.

[0066] The electron microscope image of the environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant with 8% modifier dosage prepared in Example 1 is shown in FIG. Figure 2 .

[0067] The electron microscope image of the environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant with a modifier dosage of 16% prepared in Example 2 is shown in FIG. Figure 3 .

[0068] Figure 4 The particle size distribution of environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant with different modifier dosages (0%, 4%, 8%, 16%) shows that the four modification concentrations do not affect the particle size of the powder. The particle sizes are all at the same order of magnitude, and the particle size distribution is uniform and stable.

[0069] The X-ray photoelectron spectrum of the environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant with 8% modifier dosage prepared in Example 1 is shown in FIG. Figure 5 ;

[0070] Thermogravimetric curve of modified powder Figure 6 , indicating that the explosion suppressant prepared by the present invention has a good heat absorption effect.

[0071] Experimental Example 2

[0072] Explosion suppression performance test

[0073] This experiment used a 20L spherical explosive device system consisting of an experimental chamber, a gas distribution system, a powder spraying system, a pulse ignition system, and a data acquisition system. Gas premixing was controlled using a partial pressure method: the chamber pressure was first reduced to -0.03 MPa using a vacuum pump. A fixed amount of hydrogen was then injected to restore the pressure to normal. The mixed gas concentration was controlled with an accuracy of ±0.1%. The powder spraying system was equipped with a 600mL powder storage tank. 1MPa high-pressure air was used to atomize the powder through a bottom-rebound nozzle. The spraying duration was 50ms, and the ignition delay was set to 60ms. The ignition system used a central electrode pulse ignition with an energy configuration of 10J (Quet al., 2024b). The dynamic changes in explosion pressure within the range of 0-4MPa were recorded in real time. All experiments were conducted at room temperature (25±2°C) and atmospheric pressure (101.3kPa).

[0074] In the experiments, the H2 volume fractions were 20.1%, 29.6%, and 37%, respectively. The amount of each explosion suppressant added ranged from 0 to 30g. All gases were sourced from Jiaozuo Xinbailong Trading Co., Ltd. and had a purity greater than 99.9%.

[0075]

[0076] Where, is the equivalent ratio; F / A is the ratio of the H2 volume fraction to the air volume fraction during actual combustion; and (F / A)stoic is the ratio of the H2 concentration to the air concentration during ideal complete combustion. Table 1 summarizes the experimental conditions.

[0077] Table 1 Experimental conditions

[0078]

[0079] The explosion suppression effect of modified powder is shown in Figure 7 ( Figure 7 In each equivalent ratio experimental group in the middle and left figures, the inhibitor masses in the bars from left to right are 0, 5, 10, 15, 20, 25, 30); Figure 7 The middle left figure shows the maximum explosion pressure at different hydrogen gas volume fractions with different inhibitor masses. As shown in the figure, the maximum explosion pressure decreases significantly with the increase of inhibitor mass; Figure 7 The middle left figure shows the pressure rise rate at different inhibitor masses and different hydrogen gas volume fractions. The pressure rise rate decreases significantly with the increase of inhibitor mass.

[0080] Experimental Example 2

[0081] The hydrophobicity of environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressants with different modifier dosages (2%, 4%, 8%, and 16%) was tested and accurately and reliably measured using a contact angle meter (SDC-100). Figure 8 .

[0082] Figure 8 As shown, the contact angles of the environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant with a modifier dosage of 4% are 145.6° at 0s, 144.8° at 10s, and 144.3° at 30s; and it shows that the modifier dosages of 4%, 8%, and 16% all have good hydrophobic effects.

[0083] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant, characterized in that: The following steps are involved: S1. The nano-silica sol, functional modifier, solvent, and catalyst are mixed to obtain a mixed solution A; S2. The ultrafine fire extinguishing base dispersion, the initiator is mixed to obtain a mixture B; S3. Mix the mixed solution A and the mixed solution B evenly and heat them in a water bath for reaction. Then, filter, wash and dry them in sequence to obtain an environmentally friendly nano-silica sol-based hydrophobic cold aerosol explosion suppressant.

2. The preparation method according to claim 1, characterized in that The mass ratio of the nano-silica sol, functional modifier, solvent and catalyst in S1 is (5-15): (1-5): (20-60): (0.1-4).

3. The preparation method according to claim 2, characterized in that The nano silica sol is acidic nano silica sol; the particle size of the nano silica sol is 1 to 500 nm.

4. The preparation method according to claim 3, characterized in that The acidic nano-silica sol is prepared from one or more of ethyl orthosilicate, tetramethoxysilane, methyltriethoxysilane, ethyl silicate 28, ethyl silicate 32, ethyl silicate 40, tetramethylsilane, tetraethylsilane, and polydimethylsiloxane.

5. The preparation method according to claim 1, characterized in that The functional modifier in S1 is one or more of nine-carbon perfluoropolyether siloxane, tridecafluorooctyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropylmethyldimethoxysilane, trifluoropropyltriethoxysilane, tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, and heptadecafluorodecyltriethoxysilane.

6. The preparation method according to claim 1, characterized in that The catalyst in S1 is at least one of hydrochloric acid, acetic acid, sulfuric acid, nitric acid, phosphoric acid, and formic acid.

7. The preparation method according to claim 1, characterized in that The mass concentration of the ultrafine fire extinguishing base material dispersion in S2 is 10-50%; the initiator accounts for 0.5-5% of the mass of the solution.

8. The preparation method according to claim 7, characterized in that The ultrafine fire extinguishing base material in the ultrafine fire extinguishing base material dispersion is bicarbonate, carbonate and phosphate, and the particle size of the ultrafine fire extinguishing base material is less than 10 μm.

9. The preparation method according to claim 7, characterized in that The initiator is one of ammonia water, sodium hydroxide, potassium hydroxide, sodium carbonate, tetramethylammonium hydroxide or triethylamine.

10. The preparation method according to claim 1, characterized in that The volume ratio of the mixed solution A to the mixed solution B in S3 is 1:3.

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