Method for preparing carbon dioxide-based gel foam and testing stability of carbon dioxide-based gel foam

Abstract

The invention provides a method for preparing carbon dioxide-based gel foam and testing stability of the carbon dioxide-based gel foam. The carbon dioxide-based gel foam is prepared by introducing carbon dioxide gas into a gel solution. The gel solution comprises the following components in percentage by mass: 0.2%-1.5% of a compound foaming agent, 0.2%-0.8% of a compound gelling agent, 0.3%-1.5% of a cross-linking agent, 0.1%-1.0% of a foam stabilizer, 0.2%-1.0% of an auxiliary agent and the balance of water. According to the stability testing method, foam is injected through the stability testing device, pressurization testing is conducted, the concentration of carbon dioxide and the foam stacking height are recorded so as to evaluate the stability and fluidity of the foam, and the structural strength and stability of the foam are evaluated by monitoring the concentration change of the carbon dioxide and pressure distribution.

Description

Technical Field

[0001] The present application relates to the field of fire extinguishing materials, and in particular to a method for preparing and testing the stability of a carbon dioxide-based gel foam. Background Art

[0002] With the accelerated advancement of industrialization and the development and utilization of natural resources, my country is facing severe challenges from frequent mine goaf fires and forest fires while taking advantage of the economic benefits brought by its rich mineral resources and vast forest areas. Forest fires are difficult to be effectively controlled because of their rapid spread and wide impact areas; while mine goaf fires are a typical semi-open and closed space, and the presence of flammable materials such as coal and wooden supports left in the goaf makes the spontaneous combustion of coal a major cause of frequent fires.

[0003] The use of fire-fighting gel foam for fire prevention has been proven to be an economical and effective method. In the prior art, gel foam is usually prepared by passing carbon dioxide gas into a gel containing a thiourea structure, and the stability of the gel foam is tested by measuring the size change of the gel foam, observing the appearance change, and detecting the change of mechanical properties.

[0004] However, due to different choices of gelling agents, the stability of the prepared gel foam varies significantly, resulting in complex and costly preparation processes. In addition, gel foams are not stable during transportation and storage, and are prone to rupture or gas escape. Moreover, when evaluating the stability of gel foams, existing test methods are highly subjective and lack reliable quantitative indicators. Summary of the invention

[0005] The embodiments of the present application provide a method for preparing and testing the stability of a carbon dioxide-based gel foam, so as to solve the problems of insufficient stability and limited application range of the gel foam.

[0006] In a first aspect, the present invention provides a gel solution, which is composed of the following by mass percentage:

[0007] Compound foaming agent 0.2% to 1.5%, compound gelling agent 0.2% to 0.8%, cross-linking agent 0.3% to 1.5%, foam stabilizer 0.1% to 1.0%, auxiliary agent 0.2% to 1.0%, and the balance is water;

[0008] The preparation method of the gel solution is as follows:

[0009] Mixing 0.2% to 0.8% by mass of a composite gelling agent and a foam stabilizer within the same concentration range in a mass ratio of 1:1 to obtain a mixture;

[0010] Add the mixture into a beaker and heat in a water bath until completely dissolved;

[0011] Add the compound foaming agent, cross-linking agent, auxiliary agent and water into the beaker, and stir quickly with a stirrer until it is fully foamed;

[0012] The stirring was continued until the gel foam no longer flowed when the beaker was shaken, to obtain the gel solution.

[0013] In a feasible implementation, the compound foaming agent includes 0.2% to 1.5% by mass of sodium lauryl sulfate and 0.2% to 1.5% by mass of fatty alcohol polyoxyethylene ether 9.

[0014] In a feasible implementation, the compound gelling agent includes 0.2% to 0.8% by mass of polydimethylsiloxane and 0.2% to 0.8% by mass of sodium carboxymethylcellulose.

[0015] In a feasible implementation, the cross-linking agent includes 0.3% to 1.5% by mass of polyethylene polyamine or 0.3% to 1.5% by mass of trimethylolpropane.

[0016] In a feasible implementation, the foam stabilizer includes 0.2% to 0.8% by mass of sodium carboxymethyl cellulose or 0.2% to 0.8% by mass of Tween series.

[0017] In a feasible implementation, the auxiliary agent includes sodium hydroxide, sodium carbonate or calcium carbonate.

[0018] In a feasible implementation, the preparation method of the composite foaming agent is as follows:

[0019] The foaming effects of various foaming agents were measured by the Waring Blender method. The foaming agents included sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium α-olefin sulfonate, sodium sulfate of fatty alcohol polyoxyethylene ether, sodium secondary alkyl sulfonate, sodium sulfonated dioctyl sulfosuccinate, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, cocamidopropyl betaine, disodium lauroamphodiacetate, lauroamidopropyl betaine, lauroamidopropyl ammonium oxide, fatty alcohol polyoxyethylene ether 9, lauryl glucoside, octylphenol polyoxyethylene ether and nonylphenol polyoxyethylene ether.

[0020] The stirrer speed was set to 1500 r / min, the stirring time was set to 2 minutes, and the foam volume and the precipitate volume in the container were read immediately after the stirring was completed. The foam volume was used to characterize the foaming effect of the foaming agent.

[0021] The foaming properties of the multiple foaming agents are tested and the foaming effects are ranked, and three foaming agents with the best foaming effects are screened out.

[0022] The three best foaming agents screened out were compounded in pairs to obtain three compound foaming agents, and the compound foaming agents were subjected to foaming tests. The stirrer speed was set to 1500r / min, the stirring time was 2 minutes, and the foam volume and precipitate volume in the container were read immediately after the stirring was completed. The foam volume was used to characterize the foaming effect of the compound foaming agent.

[0023] Finally, sodium lauryl sulfate and fatty alcohol polyoxyethylene ether 9 were determined as the foaming agents used in the experiment, wherein the amount of sodium lauryl sulfate was 0.2% to 1.5% by mass, and the amount of fatty alcohol polyoxyethylene ether 9 was 0.2% to 1.5% by mass.

[0024] When testing blowing agents, all blowing agents were used in the same amount and concentration.

[0025] In a second aspect, an embodiment of the present application provides a carbon dioxide-based gel foam, which is prepared by introducing carbon dioxide gas into the gel solution described in the first aspect.

[0026] In a third aspect, the present application provides a method for preparing a carbon dioxide-based gel foam, comprising:

[0027] The gel solution components described in the first aspect are stirred evenly and placed in an environment of 20° C. to 25° C. for 6 to 8 hours;

[0028] A carbon dioxide solution is introduced into the gel solution at a gas-liquid volume ratio of 150:1 or 150:2, and carbon dioxide gas is continuously introduced while stirring, and the reaction is carried out at 70° C. to 80° C. for 48 hours to obtain a carbon dioxide gel foam.

[0029] In a fourth aspect, an embodiment of the present application provides a stability testing device for a carbon dioxide-based gel foam, which is used to test the stability of the carbon dioxide-based gel foam described in the third aspect, and comprises an input device 1, wherein one side of the input device 1 is provided with an inlet carbon dioxide concentration detector 5.

[0030] The sealing piston plate 7 is slidably arranged inside the input device 1, and a plurality of pressure sensors are provided on the lower surface of the sealing piston plate 7; a first inlet 71 for gel foam material is provided on the top of the sealing piston plate 7, and a second inlet 72 connected to the probe of the carbon dioxide concentration detector 5 at the inlet is provided, and a hydraulic plate 73 is also provided on the sealing piston plate 7.

[0031] The input device 1 has a first interface 11 at the bottom which can be controlled to open and close, and is connected to one end of the foam flow pipeline 4. The other end of the foam flow pipeline 4 is connected to a second interface 31 on the cylinder wall of the output device 3, and the height of the first interface 11 is higher than that of the second interface 31.

[0032] An outlet carbon dioxide concentration detector 6 is fixed on a cylinder wall of the output device 3 at one side away from the interface 31 , and a probe of the outlet carbon dioxide concentration detector 6 is arranged on the inner side of the output device 3 .

[0033] The inlet carbon dioxide concentration detector 5, the outlet carbon dioxide concentration detector 6, and the pressure sensor 8 are connected to the data acquisition device 2 via data lines, respectively.

[0034] In a feasible implementation, a flow sensor 9 is provided on the wall of one end of the foam flow pipeline 4 close to the output device 3 .

[0035] In a feasible implementation, the number of the pressure sensors 8 is at least two.

[0036] In a feasible implementation, the foam flow pipeline 4 is made of polyethylene.

[0037] In a fifth aspect, the present application provides a method for testing the stability of a carbon dioxide-based gel foam, the method comprising the following steps:

[0038] Open the gel foam material inlet on the sealing piston plate, continuously pass the carbon dioxide-based gel foam described in the third aspect into the input device through the gel foam material inlet, and extend the probe of the carbon dioxide concentration detector into the input device through the inlet; test and record the carbon dioxide gas concentration Q1 in the input device.

[0039] Continue to inject the prepared carbon dioxide-based gel foam into the first inlet gel foam material inlet, wait for the carbon dioxide-based gel foam to be evenly distributed in the input device, and test and record the carbon dioxide gas concentration Q2 in the input device.

[0040] Open the first interface at the bottom of the input device, close the inlet of the gel foam material, and use an external oil pump to pressurize the hydraulic plate on the sealing piston plate to move the sealing piston plate down to 3 / 4 of the height of the input device. Record the position of the sealing piston plate and the reading p1 of the pressure sensor at this time; after the gel foam is evenly spread on the output device, test and record the carbon dioxide gas concentration Q3 in the output device.

[0041] The stacking height h1 of the carbon dioxide-based gel foam in the output device is measured and recorded.

[0042] By comparing the carbon dioxide gas concentration Q2 in the input device and the carbon dioxide gas concentration Q3 in the output device in the stable state.

[0043] By comparing the stacking height h1 of the carbon dioxide-based gel foam in the output device and the height of the carbon dioxide-based gel foam in the input device in the stable state.

[0044] The difference rate between the carbon dioxide gas concentration Q2 in the input device and the carbon dioxide gas concentration Q3 in the output device is calculated.

[0045] The difference rate of the carbon dioxide gas concentration in the input device and the carbon dioxide gas concentration in the output device under different pressures applied by the external oil pump was recorded.

[0046] Under the same environmental conditions such as temperature, after the same number of pressurizations and pressurization pressures, the difference in carbon dioxide concentration between the input device and the output device of carbon dioxide-based gel foams with different component ratios was compared.

[0047] Under the same environmental conditions such as temperature, after different pressurization times and pressurization pressures, the difference rate of carbon dioxide concentration between the input device and the output device of the carbon dioxide-based gel foam with the same component ratio was compared.

[0048] In the gel solution provided in the embodiment of the present application, the compound foaming agent includes sodium lauryl sulfate and fatty alcohol polyoxyethylene ether 9, and these two substances can work together to not only form stable foam, but also improve the overall stability of the gel solution, and can maintain a good state even during storage and transportation. The compound gelling agent includes polydimethylsiloxane and sodium carboxymethyl cellulose, which can work synergistically to form a soft, smooth gel structure with good water holding capacity. The gel can still maintain its original shape after being placed for a long time and is not easy to dry. The cross-linking agent includes polyethylene polyamine or trimethylolpropane, which can promote the cross-linking between the internal molecules of the gel and enhance the adhesion and elasticity of the gel. The foam stabilizer includes sodium carboxymethyl cellulose or Tween series, which can form a protective layer between the foam film through its viscous properties to enhance the stability of the foam. The auxiliary agent includes sodium hydroxide, sodium carbonate or calcium carbonate, which can adjust the pH value and provide a certain buffering effect, which helps to improve the mechanical strength and foam stability of the gel.

[0049] A carbon dioxide-based gel foam provided in an embodiment of the present application is prepared by passing carbon dioxide into a gel solution. After the gel solution is foamed, the foam formed has a higher stacking height, which means that the foam can occupy a larger space; the gel foam can also retain moisture to ensure that the foam remains moist during use. After the gel foam is foamed, the carbon dioxide gas is stably wrapped by the gel, which can isolate oxygen while keeping the surface of the combustible moist. The inert gas released after the foam bursts further inhibits the contact between the surface of the combustible and oxygen, achieving a long-term oxygen-isolating and flame-retardant effect. This is of great significance in the field of fire protection, and can improve fire extinguishing efficiency and reduce fire risks.

[0050] The stability test device of a carbon dioxide-based gel foam provided in the embodiment of the present application can replace different pipelines and set different delivery pressures. This flexibility enables the device to simulate different actual application environments and evaluate the performance of the foam under different conditions, thereby improving the reliability and accuracy of the test results.

[0051] The present application provides a method for testing the stability of a carbon dioxide-based gel foam. By simulating flow conditions (such as delivery pressure) in actual applications, the test method can evaluate the stability of the foam under dynamic conditions, that is, the changes in the foam during the flow process. The stability of the gel foam when not subjected to external forces, that is, the durability and structural integrity of the foam under static conditions, is also evaluated. Not only the stability of the foam under static conditions is considered, but also the stability under flow conditions, providing a more comprehensive evaluation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a flow chart for preparing carbon dioxide-based gel foam provided in the present application;

[0053] Figure 2 It is a schematic diagram of the structure of a stability test device for carbon dioxide-based gel foam;

[0054] Figure 3 It is the stability testing process of CO2 based gel foam.

[0055] Description of reference numerals:

[0056] 1-input device; 2-data acquisition device; 3-output device; 4-foam flow pipeline; 5-inlet carbon dioxide concentration detector; 6-outlet carbon dioxide concentration detector; 7-sealing piston plate; 8-pressure sensor; 9-flow sensor;

[0057] 11-first interface; 31-second interface; 32-export; 33-third inlet; 41-support frame; 71-first inlet; 72-second inlet; 73-hydraulic plate. DETAILED DESCRIPTION

[0058] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0059] The current method for preparing carbon dioxide gel foam is to pass carbon dioxide gas into a gel containing a thiourea structure to prepare the gel foam. Due to the different choices of gelling agents, the stability of different gel foams also varies, the preparation cost is high, the difficulty is great, the stability of the prepared gel foam is poor, the loss is large during pipeline transportation, and the gas wrapped in the foam is easy to leak out. Common stability test methods for gel foam include: measuring the size change of gel foam, observing the appearance change, detecting the change of mechanical properties, etc. These test methods all have some problems, such as the test results are highly subjective and lack of quantitative indicators. Therefore, the present invention aims to develop a method for preparing and testing the stability of carbon dioxide-based gel foam, mainly to provide new materials and stability detection methods for environments such as forests and mine goafs.

[0060] The present invention is further described below in conjunction with the examples. The concentrations "%" in the examples are all mass percentage concentrations, unless otherwise specified.

[0061] Example 1

[0062] The present application provides a gel solution, which has the following composition by mass percentage:

[0063] Compound foaming agent 0.2% to 1.5%, compound gelling agent 0.2% to 0.8%, cross-linking agent 0.3% to 1.5%, foam stabilizer 0.1% to 1.0%, auxiliary agent 0.2% to 1.0%, and the balance is water;

[0064] The preparation method of the gel solution is as follows:

[0065] Mixing 0.2% to 0.8% by mass of the composite gelling agent and the foam stabilizer within the same concentration range in a mass ratio of 1:1 to ensure that the two components are fully in contact with each other to obtain a mixture;

[0066] The mixture is added into a beaker and placed in a water bath to be heated until completely dissolved, so as to accelerate the dissolution process of the composite gelling agent and foam stabilizer so as to facilitate subsequent fusion with other ingredients;

[0067] Then add the compound foaming agent to the beaker to produce rich foam, so that it has good expansion properties, the cross-linking agent promotes the cross-linking between the internal molecules of the gel, improves the adhesion and elasticity of the gel, and the auxiliary agent adjusts other properties of the gel as needed, such as improving the rheological properties and water, and uses a stirrer to quickly stir the mixture until it is completely foamed;

[0068] The stirring was continued until the gel foam stopped flowing when the beaker was shaken, so as to obtain the gel solution, which was then placed at 20° C. for 8 h.

[0069] Take 0.2% to 0.8% by mass of the compound gelling agent and the foam stabilizer within the same concentration range, and mix them in a mass ratio of 1:1 to ensure that the two components are fully in contact and evenly distributed to form a basic mixture.

[0070] Add the above mixture to a beaker and heat it in a water bath until the composite gelling agent and foam stabilizer are completely dissolved. This step helps speed up the dissolution process of these two ingredients so that they can be better integrated with other ingredients later.

[0071] Next, add the compound foaming agent, cross-linking agent, auxiliary agent and appropriate amount of water into the beaker to achieve the desired final concentration. During this process, use a stirrer to quickly stir the mixture until the mixture is completely foamed.

[0072] The mixture was stirred continuously until the gel foam stopped flowing when the beaker was shaken, indicating that the gel had formed. At this point, stirring was stopped and the gel solution was placed in an environment of 20°C for 8 hours to ensure the stability and integrity of the gel structure.

[0073] Example 2

[0074] As shown in Example 1, the composite foaming agent includes 0.2% to 1.5% by mass of sodium dodecyl sulfate for reducing the surface tension of water and 0.2% to 1.5% by mass of fatty alcohol polyoxyethylene ether 9 with good wettability and dispersibility. Preferably, the mass percentage of sodium dodecyl sulfate is 0.8% and the mass percentage of fatty alcohol polyoxyethylene ether 9 is 0.8%.

[0075] In the embodiment of the present application, sodium lauryl sulfate and fatty alcohol polyoxyethylene ether 9 can produce rich and delicate foam. The compound use of the two substances can not only form stable foam, but also improve the overall stability of the gel solution, and can maintain a good state even during storage and transportation.

[0076] Example 3

[0077] As shown in Example 1, the compound gelling agent includes 0.2% to 0.8% by mass of polydimethylsiloxane and 0.2% to 0.8% by mass of sodium carboxymethylcellulose. Preferably, the mass percentage of polydimethylsiloxane is 0.5%, and the mass percentage of sodium carboxymethylcellulose is 0.5%. Polydimethylsiloxane has very low surface tension, excellent lubricity and flexibility, and helps to form a soft and smooth gel structure; sodium carboxymethylcellulose has good thickening and suspending properties. As a gelling agent, sodium carboxymethylcellulose can form a network structure in water, enhance the stability and viscosity of the gel, and make the gel have good water holding capacity and shape retention ability.

[0078] In the examples of the present application, the addition of polydimethylsiloxane makes the gel have a silky texture, and the presence of sodium carboxymethylcellulose enhances the structural stability of the gel, so that the gel can still maintain its original shape after being placed for a long time. The thickening effect of sodium carboxymethylcellulose and the low surface tension characteristics of polydimethylsiloxane make the gel have good water retention performance and are not easy to dry.

[0079] Example 4

[0080] As shown in Example 1, the crosslinking agent includes 0.3% to 1.5% by mass of polyethylene polyamine or 0.3% to 1.5% by mass of trimethylolpropane. Preferably, the polyethylene polyamine or trimethylolpropane is 0.5% by mass. Polyethylene polyamine has a strong crosslinking ability. As a crosslinking agent, polyethylene polyamine can promote the crosslinking between molecules inside the gel, enhance the adhesion and elasticity of the gel, and improve its mechanical strength and stability. Trimethylolpropane can react with other components in the gel through its hydroxyl group to form a three-dimensional network structure, thereby enhancing the structural strength and durability of the gel.

[0081] In the embodiments of the present application, both polyethylene polyamine and trimethylolpropane can enhance the mechanical strength of the gel by promoting intermolecular crosslinking, so that the gel is not easy to break or deform during use. The presence of a crosslinking agent makes the structure of the gel more compact and less susceptible to external environmental factors (such as temperature changes). An appropriate degree of crosslinking can give the gel better elasticity and toughness. Since the crosslinking agent can enhance the structural stability of the gel, the service life of the gel product can be extended, and product failure caused by structural failure can be reduced.

[0082] Example 5

[0083] As shown in Example 1, the foam stabilizer includes 0.2% to 0.8% by mass of sodium carboxymethyl cellulose or 0.2% to 0.8% by mass of Tween series, preferably, the mass percentage of sodium carboxymethyl cellulose or Tween series is 0.5%. Sodium carboxymethyl cellulose has good thickening and suspension properties. As a foam stabilizer, sodium carboxymethyl cellulose can form a protective layer between the foam films through its viscosity, thereby enhancing the stability of the foam and preventing the foam from bursting prematurely. The Tween series can reduce the surface tension of water, promote the formation of foam, and stabilize the foam through its surface active properties to prevent the foam film from bursting.

[0084] In the examples of the present application, both sodium carboxymethyl cellulose and Tween series can significantly improve the stability of the foam, so that the foam remains intact for a long time.

[0085] Example 6

[0086] As shown in Example 1, the auxiliary agent includes sodium hydroxide, sodium carbonate or calcium carbonate, and preferably, the mass percentage of sodium hydroxide, sodium carbonate or calcium carbonate is 0.3%. Sodium hydroxide is commonly used to adjust the pH value. In the gel solution, NaOH can be used to adjust the pH value of the system to a desired range, thereby affecting the effectiveness of other components, such as enhancing the decontamination ability of the surfactant or improving the stability of the gel. Sodium carbonate can also be used to adjust the pH value and has a certain buffering effect. In addition to adjusting the pH value, sodium carbonate can also be used as a buffer to help maintain the pH stability of the gel solution and avoid large fluctuations in the pH value due to external factors. Calcium carbonate has good stability. Calcium carbonate mainly plays the role of a filler in the gel, which can increase the consistency and touch of the gel, and also helps to improve the mechanical strength of the gel.

[0087] In the embodiments of the present application, both sodium hydroxide and sodium carbonate can effectively adjust the pH value of the gel solution to ensure that other components function under optimal conditions. The buffering effect of sodium carbonate helps to maintain the pH stability of the gel, which is very important for the long-term preservation of the gel solution. Calcium carbonate, as a filler, helps to improve the mechanical strength of the gel, making it more durable, and enhances the foam stability and foam film strength in the gel solution.

[0088] Example 7

[0089] As shown in Example 1, the preparation method of the composite foaming agent is as follows:

[0090] The foaming effects of various foaming agents are measured by the Waring Blender method, and the foaming agents include but are not limited to sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium α-olefin sulfonate, sodium sulfate of fatty alcohol polyoxyethylene ether, sodium secondary alkyl sulfonate, sodium sulfonated dioctyl succinate, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, cocamidopropyl betaine, disodium lauroamphodiacetate, lauroamidopropyl betaine, lauroamidopropyl ammonium oxide, fatty alcohol polyoxyethylene ether 9, lauryl glucoside, octylphenol polyoxyethylene ether and nonylphenol polyoxyethylene ether;

[0091] The stirrer speed was set to 1500 r / min, the stirring time was 2 minutes, and the foam volume and the precipitate volume in the container were read immediately after the stirring was completed. The foam volume was used to characterize the foaming effect of the foaming agent;

[0092] Testing the foaming properties of the multiple foaming agents and ranking the foaming effects, and selecting three foaming agents with the best foaming effects;

[0093] The three best foaming agents screened out were compounded in pairs to obtain three compound foaming agents, and the compound foaming agents were subjected to a foaming test. The stirrer speed was set to 1500r / min, the stirring time was 2 minutes, and the foam volume and the precipitate volume in the container were read immediately after the stirring was completed. The foam volume was used to characterize the foaming effect of the compound foaming agent;

[0094] Finally, sodium lauryl sulfate and fatty alcohol polyoxyethylene ether 9 were determined as the foaming agents used in the experiment, wherein the amount of sodium lauryl sulfate was 0.2% to 1.5% by mass, and the amount of fatty alcohol polyoxyethylene ether 9 was 0.2% to 1.5% by mass;

[0095] When testing blowing agents, all blowing agents were used in the same amount and concentration.

[0096] Example 8

[0097] The embodiment of the present application provides a carbon dioxide-based gel foam, which is prepared by introducing carbon dioxide gas into the gel solution described in any one of embodiments 1-7.

[0098] In the embodiment of the present application, a large number of tiny bubbles are formed in the gel solution by introducing carbon dioxide gas, so that the gel foam finally formed has a lower density. The lightweight property makes this gel foam very suitable for applications that require weight reduction. The gel solution contains a foam stabilizer, which can form a stable foam structure after the introduction of carbon dioxide gas. A stable foam structure means that it is not easy to collapse or deform during use and can be maintained for a long time. The presence of carbon dioxide bubbles gives the gel foam certain thermal insulation properties.

[0099] Example 9

[0100] See also Figure 1 As shown, the present application embodiment provides a method for preparing a carbon dioxide-based gel foam, comprising:

[0101] The gel solution components described in any one of Examples 1 to 7 are stirred evenly and placed in an environment of 20° C. to 25° C. for 6 to 8 hours;

[0102] A carbon dioxide solution is introduced into the above-mentioned gel solution at a gas-liquid volume ratio of 150:1 or 150:2, and carbon dioxide gas is continuously introduced while stirring, and the reaction is carried out at 70°C to 80°C for 48 hours to obtain a carbon dioxide gel foam. The gas-liquid volume ratio mentioned here refers to the ratio of the volume of the carbon dioxide gas introduced to the volume of the gel solution. Continuous stirring is required during the process of introducing carbon dioxide gas to ensure that the gas can be evenly dispersed in the gel solution to form a stable foam structure. The temperature range of 70°C to 80°C helps promote the interaction between the components in the gel solution to form a stable foam structure. A constant temperature needs to be maintained during the reaction to ensure the consistency of the reaction conditions.

[0103] Example 10

[0104] See also Figure 2 As shown, a stability testing device for a carbon dioxide-based gel foam according to an embodiment of the present application is used to test the stability of the carbon dioxide-based gel foam described in Example 8, and includes an input device 1. An inlet carbon dioxide concentration detector 5 is provided on one side of the input device 1. The inlet carbon dioxide concentration detector 5 can monitor the carbon dioxide concentration entering the device in real time to ensure the consistency and accuracy of the test conditions.

[0105] A sealing piston plate 7 is slidably arranged up and down inside the input device 1, and a plurality of pressure sensors 8 are provided on the lower surface of the sealing piston plate 7; a first inlet 71 for gel foam material is provided on the top of the sealing piston plate 7, and a second inlet 72 connected to the probe of the carbon dioxide concentration detector 5 at the inlet is provided, and a hydraulic plate 73 is also provided on the sealing piston plate 7. Preferably, the gel foam material inlet 71 is square with a side length of 100 mm.

[0106] The sealing piston plate 7 is used to control the amount of gel foam material entering, and the pressure change under the sealing piston plate is monitored by the pressure sensor 8, so as to indirectly understand the state of the gel foam. The hydraulic plate 73 drives the sealing piston plate 7 to move up and down, so as to control the feeding amount of the gel foam material. The pressure sensor 8 detects the pressure change of the gel foam under pressure to help evaluate its physical properties. The square gel foam material inlet design is convenient for standardizing the sample size to ensure the comparability of the test results. The bottom of the input device 1 is provided with a first interface 11 that can be controlled to open and close, which is connected to one end of the foam flow pipeline 4, and the other end of the foam flow pipeline 4 is connected to the second interface 31 on the cylinder wall of the output device 3, and the height of the first interface 11 is higher than the second interface 31. Preferably, the height difference between the first interface 11 and the second interface is 100mm; this height difference design helps the foam to flow smoothly under the action of gravity and reduce the flow resistance, and is also conducive to observing the fluidity changes of the foam under different conditions.

[0107] An outlet carbon dioxide concentration detector 6 is fixed on the cylinder wall of the output device 3 on one side away from the second interface 31, and the probe of the outlet carbon dioxide concentration detector 6 is arranged on the inner side of the output device 3; the outlet carbon dioxide concentration detector 6 can monitor the change of carbon dioxide concentration of the foam after the entire test process, so as to evaluate the stability of the gel foam.

[0108] The inlet carbon dioxide concentration detector 5, the outlet carbon dioxide concentration detector 6, and the pressure sensor 8 are respectively connected to the data acquisition device 2 through data lines. The data acquisition device 2 can collect and record the changes of various parameters during the test in real time, providing a basis for subsequent data analysis.

[0109] In the embodiment of the present application, by real-time monitoring of carbon dioxide concentration and pressure changes, the test conditions can be accurately controlled to ensure the accuracy and reliability of the test results. Through the data acquisition device 2, various key data on the stability test of the gel foam can be collected to provide detailed information support for analyzing the performance of the gel foam. By comparing the changes in carbon dioxide concentration at the inlet and outlet, the stability of the gel foam can be directly reflected, which is convenient for quickly judging the quality of the gel foam. The device is reasonably designed, the operation process is simple and clear, the operation difficulty is reduced, and the test efficiency is improved. The stability testing device helps to comprehensively evaluate the performance of carbon dioxide-based gel foam and ensure its reliability and effectiveness in practical applications.

[0110] Embodiment 11

[0111] See also Figure 2As shown in Example 10, a flow sensor 9 is provided on the wall of the foam flow pipeline 4 near the output device 3. The flow sensor 9 is installed at the end of the foam flow pipeline 4 near the input device 1 to monitor the gel foam flow through the pipeline in real time.

[0112] In the embodiment of the present application, the flow sensor 9 can accurately measure the flow rate of the foam. By monitoring the change in the flow rate, the loss of the foam after being transmitted over a certain distance can be evaluated, and then the stability of the foam can be determined.

[0113] Example 12

[0114] See also Figure 2 As shown in Example 10, the number of the pressure sensors 8 is at least two, which are used to monitor the pressure changes of the gel foam at different positions.

[0115] In the embodiment of the present application, by setting up multiple pressure sensors, the pressure distribution of the gel foam during the test can be more comprehensively understood, so as to better evaluate the stability and structural strength of the foam. Multiple sensors can provide more accurate pressure data.

[0116] Embodiment 13

[0117] See also Figure 2 As shown in Example 10, the foam flow pipeline 4 is made of polyethylene, which has good chemical stability and mechanical strength and strong corrosion resistance. A support frame 41 is provided below the foam flow pipeline for fixing and supporting the pipeline. Preferably, the radius of the foam flow pipeline 4 is 50 mm, and the length of the foam flow pipeline 4 is 500 mm. The larger radius and moderate length can ensure that the foam has enough space to expand during the flow process, and the flow resistance in the pipeline is relatively small, which is conducive to the stable transmission and testing of the foam.

[0118] In the embodiment of the present application, the polyethylene pipe and the appropriate size design ensure that the flow state of the foam during the test can truly reflect its performance, thereby improving the accuracy of the test results. The design of the support frame 41 makes the test device more stable, which can be operated more conveniently during the test and reduce the error caused by the instability of the equipment. The polyethylene pipe is easy to clean and maintain, which reduces the workload of device maintenance and prolongs the service life of the device.

[0119] Embodiment 14

[0120] See also Figure 3 As shown, the present application embodiment provides a method for testing the stability of a carbon dioxide-based gel foam, the method comprising the following steps:

[0121] Open the gel foam material inlet on the sealing piston plate to ensure that the gel foam can smoothly enter the test device. Continue to pass the carbon dioxide-based gel foam described in Example 8 into the input device through the gel foam material inlet, extend the probe of the carbon dioxide concentration detector into the input device through the inlet, monitor the carbon dioxide concentration in the input device in real time, test and record the carbon dioxide gas concentration Q1 in the input device, and provide baseline data for subsequent comparison with the concentration after the gel foam enters;

[0122] Continue to inject the prepared carbon dioxide-based gel foam into the first inlet gel foam material inlet, wait for the carbon dioxide-based gel foam to be evenly distributed in the input device, and test and record the carbon dioxide gas concentration Q2 in the input device;

[0123] Open the first interface at the bottom of the input device, close the gel foam material inlet, use an external oil pump to pressurize the hydraulic plate on the sealing piston plate, move the sealing piston plate down to 3 / 4 of the height of the input device, and record the position of the sealing piston plate and the reading p1 of the pressure sensor at this time; after the gel foam is evenly spread on the output device, test and record the carbon dioxide gas concentration Q3 in the output device; Q3-Q1=Q4 can represent the leakage amount of carbon dioxide gas wrapped in bubbles;

[0124] Measure and record the stacking height h1 of the carbon dioxide-based gel foam in the output device;

[0125] By comparing the carbon dioxide gas concentration Q2 in the input device with the carbon dioxide gas concentration Q3 in the output device in a stable state;

[0126] By comparing the stacking height h1 of the carbon dioxide-based gel foam in the output device and the height of the carbon dioxide-based gel foam in the input device in the steady state;

[0127] Calculate the difference between the carbon dioxide gas concentration Q2 in the input device and the carbon dioxide gas concentration Q3 in the output device. The greater the difference, the worse the foam stability and the more serious the rupture and fusion.

[0128] Record the difference rate between the carbon dioxide gas concentration in the input device and the carbon dioxide gas concentration in the output device under different pressures applied by the external oil pump;

[0129] Under the same environmental conditions such as temperature, after the same number of pressurizations and pressurization pressures, the difference rate of carbon dioxide concentration between the input device and the output device of carbon dioxide-based gel foams with different component ratios is compared;

[0130] Under the same environmental conditions such as temperature, after different pressurization times and pressurization pressures, the difference rate of carbon dioxide concentration between the input device and the output device of the carbon dioxide-based gel foam with the same component ratio is compared. In the embodiment of the present application, the stability, fluidity and structural strength of the gel foam are comprehensively evaluated by recording the carbon dioxide concentration and the gel foam stacking height under different conditions. The accuracy and repeatability of the test results are ensured by real-time monitoring and recording the changes in various parameters. Based on the test results, the formula and production process of the gel foam can be optimized to improve its stability and other performance indicators. By simulating different pressurization conditions, the situation in actual applications can be better simulated, and the performance of the gel foam under different conditions can be evaluated, which is helpful to comprehensively evaluate the performance of the carbon dioxide-based gel foam.

[0131] According to the above technical features, the working principle of the preparation and stability testing method of the carbon dioxide-based gel foam provided by the present application in the actual application scenario is:

[0132] First, a gel solution is prepared according to any gel solution formula in Examples 1-7, which includes ingredients such as a compound foaming agent, a compound gelling agent, a cross-linking agent, a foam stabilizer, and an auxiliary agent. The above gel solution is placed in a reaction vessel, and while stirring, carbon dioxide gas is introduced into the gel solution at a gas-liquid volume ratio of 150:1 or 150:2 and a carbon dioxide solution is added at the same time. The stirring and ventilation process is to ensure that the carbon dioxide gas can be evenly dispersed in the gel solution to form a stable foam structure. The gel solution is allowed to react with the carbon dioxide gas at 70°C to 80°C for 48 hours. Through appropriate temperature and time conditions, the chemical reaction between the components in the gel solution is promoted to form a stable foam structure.

[0133] The prepared carbon dioxide-based gel foam is continuously introduced into the input device through the gel foam material inlet, and the probe of the carbon dioxide concentration detector is extended into the input device. The gel foam material inlet on the sealing piston plate is opened, and the carbon dioxide gas concentration Q1 in the input device is recorded. The gel foam is continued to be injected into the input device until it is evenly distributed in the input device, and the carbon dioxide gas concentration Q2 at this time is recorded. The gel foam material inlet is closed, the first interface at the bottom of the input device is opened, and the hydraulic plate on the sealing piston plate is pressurized with an external oil pump to move the sealing piston plate down to 3 / 4 of the height of the input device, and the pressure sensor reading p1 at this time is recorded. After the gel foam is evenly spread on the output device, the carbon dioxide gas concentration Q3 in the output device is recorded. The gel foam accumulation height h1 in the output device is measured and recorded. By comparing the carbon dioxide gas concentration Q2 in the input device with the carbon dioxide gas concentration Q3 in the output device under stable conditions, the concentration difference rate is calculated; by comparing the gel foam accumulation heights in the input device and the output device, the stability of the foam is evaluated. Under the same environmental conditions such as temperature, after the same number of pressurizations and pressurization pressures, the difference rate of carbon dioxide concentration between the input device and the output device of carbon dioxide-based gel foam with different component ratios is compared. Under the same environmental conditions such as temperature, after the same number of pressurizations and pressurization pressures, the difference rate of carbon dioxide concentration between the input device and the output device of carbon dioxide-based gel foam with the same component ratio is compared.

[0134] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application to obtain other embodiments based on the several embodiments provided in the present application, and these embodiments do not exceed the protection scope of the present application.

[0135] The above specific implementation methods further explain in detail the purpose, technical solutions and beneficial effects of the embodiments of the present application. It should be understood that the above are only specific implementation methods of the embodiments of the present application and are not used to limit the protection scope of the embodiments of the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A gel solution, characterized in that: The composition by mass percentage is as follows: Compound foaming agent 0.2% to 1.5%, compound gelling agent 0.2% to 0.8%, cross-linking agent 0.3% to 1.5%, foam stabilizer 0.1% to 1.0%, auxiliary agent 0.2% to 1.0%, and the balance is water; The preparation method of the gel solution is as follows: Mixing 0.2% to 0.8% by mass of a composite gelling agent and a foam stabilizer within the same concentration range in a mass ratio of 1:1 to obtain a mixture; Add the mixture into a beaker and heat in a water bath until completely dissolved; Add the compound foaming agent, cross-linking agent, auxiliary agent and water into the beaker, and stir quickly with a stirrer until it is fully foamed; The stirring was continued until the gel foam no longer flowed when the beaker was shaken, to obtain the gel solution.

2. The gel solution according to claim 1, characterized in that The composite foaming agent comprises 0.2% to 1.5% by mass of sodium lauryl sulfate and 0.2% to 1.5% by mass of fatty alcohol polyoxyethylene ether 9.

3. The gel solution according to claim 1, characterized in that The compound gelling agent comprises 0.2% to 0.8% by mass of polydimethylsiloxane and 0.2% to 0.8% by mass of sodium carboxymethyl cellulose.

4. The gel solution according to claim 1, characterized in that The cross-linking agent includes 0.3% to 1.5% by mass of polyethylene polyamine or 0.3% to 1.5% by mass of trimethylolpropane.

5. The gel solution according to claim 1, characterized in that The foam stabilizer comprises 0.2% to 0.8% by mass of sodium carboxymethyl cellulose or 0.2% to 0.8% by mass of Tween series.

6. The gel solution according to claim 1, characterized in that The auxiliary agent includes sodium hydroxide, sodium carbonate or calcium carbonate.

7. The gel solution according to claim 1, characterized in that The preparation method of the composite foaming agent is as follows: The foaming effects of various foaming agents are measured by the Waring Blender method, and the foaming effects include sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium α-olefin sulfonate, sodium sulfate of fatty alcohol polyoxyethylene ether, sodium secondary alkyl sulfonate, sodium sulfonated dioctyl succinate, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, cocamidopropyl betaine, disodium lauroamphodiacetate, lauroamidopropyl betaine, lauroamidopropyl ammonium oxide, fatty alcohol polyoxyethylene ether 9, lauryl glucoside, octylphenol polyoxyethylene ether, and nonylphenol polyoxyethylene ether. The stirrer speed was set to 1500 r / min, the stirring time was 2 minutes, and the foam volume and the precipitate volume in the container were read immediately after the stirring was completed. The foam volume was used to characterize the foaming effect of the foaming agent; Testing the foaming properties of the multiple foaming agents and ranking the foaming effects, and selecting three foaming agents with the best foaming effects; The three best foaming agents screened out were compounded in pairs to obtain three compound foaming agents, and the compound foaming agents were subjected to a foaming test. The stirrer speed was set to 1500r / min, the stirring time was 2 minutes, and the foam volume and the precipitate volume in the container were read immediately after the stirring was completed. The foam volume was used to characterize the foaming effect of the compound foaming agent; Finally, sodium lauryl sulfate and fatty alcohol polyoxyethylene ether 9 were determined as the foaming agents used in the experiment, wherein the amount of sodium lauryl sulfate was 0.2% to 1.5% by mass, and the amount of fatty alcohol polyoxyethylene ether 9 was 0.2% to 1.5% by mass; When testing blowing agents, all blowing agents were used in the same amount and concentration.

8. A carbon dioxide-based gel foam, characterized in that: The carbon dioxide-based gel foam is prepared by introducing carbon dioxide gas into the gel solution according to any one of claims 1 to 7.

9. A method for preparing a carbon dioxide-based gel foam, characterized in that: include: Stirring the gel solution components according to any one of claims 1 to 7 uniformly and placing them in an environment of 20° C. to 25° C. for 6 to 8 hours; A carbon dioxide solution is introduced into the gel solution at a gas-liquid volume ratio of 150:1 or 150:2, and carbon dioxide gas is continuously introduced while stirring, and the reaction is carried out at 70° C. to 80° C. for 48 hours to obtain a carbon dioxide gel foam.

10. A stability testing device for carbon dioxide-based gel foam, used for testing the stability of the carbon dioxide-based gel foam according to claim 8, characterized in that: It comprises an input device (1), wherein one side of the input device (1) is provided with an inlet carbon dioxide concentration detector (5); A sealing piston plate (7) is slidably disposed inside the input device (1) up and down, and a plurality of pressure sensors are disposed on the lower surface of the sealing piston plate (7); a first inlet (71) for a gel foam material inlet and a second inlet (72) connected to a probe of a carbon dioxide concentration detector (5) at the inlet are provided on the top of the sealing piston plate (7); a hydraulic plate (73) is also provided on the sealing piston plate (7); The input device (1) has a first interface (11) at the bottom thereof which can be controlled to be opened and closed and is connected to one end of a foam flow pipeline (4); the other end of the foam flow pipeline (4) is connected to a second interface (31) on the cylinder wall of the output device (3); and the height of the first interface (11) is higher than that of the second interface (31); An outlet carbon dioxide concentration detector (6) is fixed on a cylinder wall of the output device (3) at a side away from the second interface (31), and a probe of the outlet carbon dioxide concentration detector (6) is arranged on the inner side of the output device (3); The inlet carbon dioxide concentration detector (5), the outlet carbon dioxide concentration detector (6), and the pressure sensor (8) are respectively connected to the data acquisition device (2) via data lines.

11. The stability testing device for carbon dioxide-based gel foam according to claim 10, characterized in that: A flow sensor (9) is provided on the pipe wall of one end of the foam flow pipe (4) close to the output device (3).

12. The stability testing device for carbon dioxide-based gel foam according to claim 10, characterized in that: The number of the pressure sensors (8) is at least two.

13. The stability testing device for carbon dioxide-based gel foam according to claim 10, characterized in that: The foam flow pipeline (4) is made of polyethylene.

14. A method for testing the stability of carbon dioxide-based gel foam, characterized in that: The method comprises the following steps: Open the gel foam material inlet on the sealing piston plate, continuously introduce the carbon dioxide-based gel foam described in claim 8 into the input device through the gel foam material inlet, and extend the probe of the carbon dioxide concentration detector into the input device through the inlet; test and record the carbon dioxide gas concentration Q1 in the input device; Continue to inject the prepared carbon dioxide-based gel foam into the first inlet gel foam material inlet, wait for the carbon dioxide-based gel foam to be evenly distributed in the input device, and test and record the carbon dioxide gas concentration Q2 in the input device; Open the first interface at the bottom of the input device, close the gel foam material inlet, use an external oil pump to pressurize the hydraulic plate on the sealing piston plate, move the sealing piston plate down to 3 / 4 of the height of the input device, and record the position of the sealing piston plate and the reading p1 of the pressure sensor at this time; after the gel foam is evenly spread on the output device, test and record the carbon dioxide gas concentration Q3 in the output device; Measure and record the stacking height h1 of the carbon dioxide-based gel foam in the output device; By comparing the carbon dioxide gas concentration Q2 in the input device with the carbon dioxide gas concentration Q3 in the output device in a stable state; By comparing the stacking height h1 of the carbon dioxide-based gel foam in the output device and the height of the carbon dioxide-based gel foam in the input device in the steady state; Calculating the difference rate between the carbon dioxide gas concentration Q2 in the input device and the carbon dioxide gas concentration Q3 in the output device; Record the difference rate between the carbon dioxide gas concentration in the input device and the carbon dioxide gas concentration in the output device under different pressures applied by the external oil pump; Under the same environmental conditions such as temperature, after the same number of pressurizations and pressurization pressures, the difference rate of carbon dioxide concentration between the input device and the output device of carbon dioxide-based gel foams with different component ratios is compared; Under the same environmental conditions such as temperature, after different pressurization times and pressurization pressures, the difference rate of carbon dioxide concentration between the input device and the output device of the carbon dioxide-based gel foam with the same component ratio was compared.

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