Water-based gel foam for blocking volatile organic compounds

Abstract

The invention discloses a water-based gel foam for blocking volatile organic compounds. The water-based gel foam is prepared from a composite foaming agent, a gelling agent, a foam stabilizer, an antifreeze agent, a humectant, a cosolvent and water, the mass fraction of each component is as follows: 0.001-0.5% of the composite foaming agent, 0.1-0.5% of the gelling agent, 0-0.5% of the foam stabilizer, 0.15% of the antifreeze agent, 0.2% of the humectant, 0.1% of the cosolvent and the balance of water. The preparation method of the water-based gel foam comprises the following steps: S1, preparing foam components; s2, preparing a gel component; and S3, mixing and uniformly stirring the foam component and the gel component, pouring the mixture into a foaming device, and carrying out foaming operation to obtain the water-based gel foam. Green and environment-friendly preparation materials are adopted, self-made hydrophilic nano silicon dioxide particles are added, and rich hydroxyl groups on the surfaces of the self-made hydrophilic nano silicon dioxide particles are combined with a water phase, a foaming agent and gelling agent molecules through hydrogen bonds and can also serve as cross-linking points to be combined with a three-dimensional gel network of a gelling agent, so that the foam drainage time is prolonged, and the foam stability is enhanced; and the purpose of blocking volatile organic compounds for a long time is achieved.

Description

Technical Field

[0001] This invention relates to the field of environmental protection and emergency management technology, and in particular to a water-based gel foam for blocking volatile organic compounds, its preparation method and application. Background Technology

[0002] Volatile organic compounds (VOCs) are a common type of air pollutant generated during industrial production and daily life. They have wide-ranging sources and are mostly toxic, carcinogenic, and flammable. VOC leaks not only severely damage the surrounding ecological environment but also directly threaten human health and safety. my country has clearly stated its intention to accelerate the comprehensive management of VOC emissions. However, while structural membrane barrier technology is currently an effective method to prevent VOC diffusion, a comprehensive and effective solution has not yet been developed.

[0003] Water-based foam materials have attracted initial attention for their excellent barrier properties, flowability, and environmental friendliness in emergency blocking of volatile organic compounds. However, due to limited barrier time and foam stability, there have been no mature engineering applications. Existing research indicates that foam stability is the main research direction for improving its barrier performance, and based on this, water-based gel foam technology has emerged.

[0004] From the perspective of existing patented technologies, water-based foam barrier materials still have significant shortcomings in the application of volatile organic compound (VOC) blocking. The invention patent with patent publication number "CN107497837A" discloses a foam barrier material and its application suitable for soil contaminated by VOCs. This foam barrier material does not cause environmental pollution, is energy-saving and environmentally friendly, and has a wide range of applications. It can be used to suppress dust, cover liquid pools, block odors, and isolate air. However, the core effect of this patent is not superior to existing technologies. The invention patent with publication number "CN103484127B" discloses a foam for treating polluted soil and its treatment method. In this patent, the foam can adsorb and dissolve soil pollutants by covering the soil with its surface adsorption capacity and bactericidal components. However, the polyacrylamide (high molecular polymer) added to the formula is prone to agglomeration in the foam liquid film, which destroys the uniformity of the liquid film and shortens the foam half-life to less than 8 hours. Moreover, the phenolic bactericidal substances themselves are volatile and have an irritating odor, which not only causes secondary pollution, but their strong oxidizing properties can also destroy the beneficial bacteria community in the soil, leading to the degradation of soil ecological function. At the same time, in the volatile organic compound barrier test, the barrier efficiency of the foam did not reach more than 80%. Patent publication number CN117603705A discloses a green water-based foam barrier material for soil contaminated with volatile organic compounds, its preparation, and its application. This patent uses green and safe raw materials, has minimal impact on the soil ecosystem, and features a highly efficient foaming system with good foam stability. However, the use of natural raw materials such as plant-derived proteins and cellulose results in high costs, limiting its market application in large-scale soil remediation projects. Furthermore, natural proteins are prone to degradation at high temperatures (>35℃) or high humidity, leading to a sharp decline in foam stability. Patent publication number CN119120036A discloses a barrier agent composition, a barrier foaming agent, its preparation method, and a soil remediation foam and remediation method. This patent boasts excellent foam performance and is environmentally friendly. However, it requires complex modification of natural proteins, resulting in high costs and a complex method.

[0005] In summary, current water-based foams still have significant shortcomings in blocking volatile organic compounds (VOCs). They generally suffer from insufficient foam stability, substandard core blocking performance, and some formulations are prone to secondary pollution or excessively expensive. These issues make it difficult to meet the long-lasting, efficient, and low-cost VOC blocking requirements in engineering scenarios. Therefore, it is necessary to make targeted improvements to their formulations and preparation processes. This invention focuses on optimizing the compound system of gelling agents and foam stabilizers to improve foam stability, enabling it to cover for extended periods without defoaming, thus achieving long-term VOC blocking. Summary of the Invention

[0006] The purpose of this invention is to address the aforementioned problems by providing a water-based gel foam for blocking volatile organic compounds (VOCs). This foam features a scientifically designed formula, good thermal stability, high expansion ratio, long drainage half-life, high overall foam index, excellent barrier effect, and is environmentally friendly and pollution-free. The preparation method provided by this invention is simple, convenient to operate, and easy to industrialize. Another objective of this invention is to provide the application of the aforementioned water-based gel foam for blocking VOCs in emergency control of VOC leaks, effectively solving the problems of rapid barrier and long-term control after VOC leaks.

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

[0008] A water-based gel foam for blocking volatile organic compounds, the water-based gel foam being composed of a composite foaming agent, a gelling agent, a foam stabilizer, an antifreeze agent, a humectant, a cosolvent, and water; the mass fraction of each component is as follows: composite foaming agent 0.001-0.5%, gelling agent 0.1-0.5%, foam stabilizer 0-0.5%, antifreeze agent 0.15%, humectant 0.2%, cosolvent 0.1%, and the balance being water.

[0009] Furthermore, the mass fraction of each component in the water-based gel foam is as follows: 0.1% composite foaming agent, 0.2% gelling agent, 0.3% foam stabilizer, 0.15% antifreeze agent, 0.2% humectant, 0.1% cosolvent, and the balance is water.

[0010] Furthermore, the composite foaming agent is prepared by compounding sodium fatty alcohol polyoxyethylene ether sulfate or hexadecyltrimethylammonium bromide with alkyl glycoside or dodecyl dimethyl betaine in pairs, with the total concentration of the compound solution set at 0.1% and the ratio set at 10:0 ~ 0:10.

[0011] Furthermore, the gelling agent is one or a combination of xanthan gum, sodium alginate, and gum arabic.

[0012] Furthermore, the foam stabilizer is a hydrophilic nano-silica prepared by plasma treatment, and the preparation steps are as follows:

[0013] S1. Disperse hydrophobic nano-silica evenly in an appropriate amount of anhydrous ethanol, and treat with ultrasound for 30 minutes to form a uniform suspension.

[0014] S2. Use a dropper to evenly apply the nano-silica suspension onto a glass slide.

[0015] S3. Place the glass slide coated with nano-silica in a 60℃ constant temperature drying oven and dry for 12 hours.

[0016] S4. Place the glass slide into the processing chamber of the plasma cleaner.

[0017] S5. Start the vacuum pump to evacuate the processing chamber to a certain vacuum level. Then, introduce oxygen into the processing chamber and adjust the gas flow rate to 30 sccm. Set the equipment power to 150W and the processing time to 20 minutes.

[0018] S6. Start the plasma generator so that the active particles in the plasma generated in the chamber react with the hydrophobic groups on the surface of the hydrophobic nano-silica, destroying the hydrophobic structure and introducing the hydrophilic hydroxyl group.

[0019] S7. After the processing time is over, wait for the pressure in the chamber to return to normal before taking out the processed sample.

[0020] S8. The modified silica was pressed into sheets, and the water contact angle was measured using an interfacial rheometer. The contact angle was less than 30°, indicating that the hydrophilic nano silica was successfully prepared.

[0021] Furthermore, the antifreeze agent is ethylene glycol, the humectant is glycerol, and the cosolvent is ethylene glycol butyl ether.

[0022] A method for preparing a water-based gel foam for blocking volatile organic compounds includes the following steps:

[0023] S1. Prepare foam components;

[0024] S2. Preparation of gel components;

[0025] S3. Mix the foam component and gel component and stir evenly. Pour the mixture into a foaming device and perform a foaming operation to obtain the prepared water-based gel foam.

[0026] Furthermore, step S1 includes the following steps:

[0027] S11. Weigh out ethylene glycol butyl ether, glycerol and ethylene glycol in proportion, add them to a beaker containing a certain amount of water in sequence, stir well and let them dissolve completely.

[0028] S12. Weigh out sodium fatty alcohol polyoxyethylene ether sulfate, hexadecyltrimethylammonium bromide and alkyl glycoside, dodecyl dimethyl betaine according to the proportions and mix them in pairs. Pour the four groups of reagents into four beakers containing ethylene glycol butyl ether, glycerol and ethylene glycol respectively, stir evenly and obtain foam components.

[0029] S13. Weigh out the hydrophilic nano-silica according to the proportion, add it to the beaker containing the foam component and stir evenly.

[0030] Furthermore, step S2 includes the following steps:

[0031] S21. Weigh out a certain amount of water according to the proportion and add it to the beaker;

[0032] S22. Weigh xanthan gum, sodium alginate, and gum arabic according to the proportions, and slowly add them to three beakers containing water while stirring during the addition process to obtain the gel component.

[0033] Furthermore, the application of the prepared water-based gel foam in emergency treatment of volatile organic compound leaks was tested.

[0034] Furthermore, the volatile organic compounds are toluene, ethyl acetate, and xylene.

[0035] Furthermore, when conducting barrier tests on the prepared foam, a self-designed barrier device was used for testing. The barrier device mainly consists of an air compressor, a pressure regulating valve, a liquid storage tank, a liquid syringe, a constant temperature water bath, a pressure sensor, a temperature sensor, a VOCs detector, and an adsorption column.

[0036] Furthermore, during application, the water-based gel foam is evenly covered on the surface of the area containing volatile organic compounds, and the foam coverage height is controlled to be 15cm.

[0037] Compared with the prior art, the advantages and positive effects of this invention are:

[0038] 1. This invention uses water as the main matrix, and the composite foaming agent, gelling agent and foam stabilizer are all biocompatible and easily degradable substances, which avoids the secondary pollution of soil and water bodies caused by some existing chemical barrier agents and meets environmental protection requirements.

[0039] 2. This invention uses self-made hydrophilic nano silica as a foam stabilizer. Through the triple design of "foaming agent compound + xanthan gum gel skeleton + self-made hydrophilic nano silica foam stabilizer", the long-term stability of the foam is greatly improved, resulting in a foam with a sufficiently long lifespan and strong anti-burst ability.

[0040] 3. This invention uses ethylene glycol as an antifreeze agent, whose solution with water can significantly lower the freezing point, solving the problem of "low-temperature failure" in existing water-based foam materials. Glycerol is used as a humectant, which locks in moisture in the gel foam through hydrogen bonding, allowing the foam to maintain a moist state and intact structure in dry, well-ventilated environments for extended periods, thus enhancing the environmental adaptability of the water-based gel foam.

[0041] 4. The materials used in this invention are inexpensive and readily available, effectively reducing product costs. The equipment requirements are low, with no need for special high-end equipment, and the operation process is simple, making it suitable for rapid preparation and immediate use in emergency situations.

[0042] 5. This invention uses a self-designed barrier device, which can accurately measure the concentration of volatile organic compounds and accurately evaluate the barrier performance of foam. In addition, this equipment can also adjust the ambient temperature through a constant temperature water bath to test the barrier performance of foam at different temperatures. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 The toluene concentration changes over time during toluene barrier experiments in Examples 2 / 4-6;

[0045] Figure 2 The graph shows the change in foam barrier rate over time during the toluene barrier experiment in Examples 2 / 4-6.

[0046] Figure 3 The change in ethyl acetate concentration over time during the ethyl acetate barrier experiments in Examples 2 / 4-6;

[0047] Figure 4 The graph shows the change in foam blocking rate over time during the ethyl acetate barrier experiment in Examples 2 / 4-6.

[0048] Figure 5 The xylene concentration changes over time during xylene barrier experiments in Examples 2 / 4-6;

[0049] Figure 6 The graph shows the change in foam barrier rate over time during xylene barrier experiments in Examples 2 / 4-6.

[0050] Figure 7 This is a structural diagram of the experimental barrier device.

[0051] In the picture: For air compressors; For pressure regulating valve; For storage tanks; For use as a liquid syringe; It is a constant temperature water bath; It is a pressure sensor; It is a temperature sensor; For VOCs detectors; It is an adsorption column. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art to all other embodiments obtained without creative effort should be included within the protection scope of the present invention.

[0053] This invention discloses a water-based gel foam for blocking volatile organic compounds, wherein the raw material components of the water-based gel foam are composed of a composite foaming agent, a gelling agent, a foam stabilizer, an antifreeze agent, a humectant, a solubilizer, and water;

[0054] The mass fractions of each component are as follows: composite foaming agent 0.001-0.5%, gelling agent 0.1-0.5%, foam stabilizer 0-0.5%, antifreeze agent 0.15%, humectant 0.2%, cosolvent 0.1%, and the balance is water.

[0055] The composite foaming agent has a mass percentage of 0.001 to 0.5% in the water-based gel foam; it is prepared by compounding sodium fatty alcohol polyoxyethylene ether sulfate or hexadecyltrimethylammonium bromide with alkyl glycoside or dodecyl dimethyl betaine in pairs, with the total concentration of the compound solution set at 0.1% and the ratio set at 10:0 to 0:10.

[0056] The function of composite foaming agents is to generate abundant foam while reducing the surface tension of water, allowing the foam to spread rapidly on volatile organic compounds, thereby achieving efficient barrier properties.

[0057] The gelling agent has a mass percentage of 0.1-0.5% in the water-based gel foam, and it is composed of one or more of xanthan gum, sodium alginate, and gum arabic. Xanthan gum, sodium alginate, and gum arabic are all soluble polysaccharide polymers with long-chain structures.

[0058] The role of gelling agents is to increase the stability of foam by forming a more stable three-dimensional network gel structure through intermolecular hydrogen bonds and hydrophobic interactions, so that the water-based gel foam can maintain a stable form and continue to function during the process of volatile organic compound blocking. After xanthan gum dissolves in water, the rigid helical molecular chains will intertwine to form a three-dimensional network structure, inhibiting the collision and fusion of adjacent bubbles due to Brownian motion, while reducing bubble wall thinning and rupture. In addition, the polar groups such as carboxyl groups on xanthan gum molecular chains will be adsorbed at the gas-liquid interface to form a high-viscosity polysaccharide adsorption film. Sodium alginate is an anionic polysaccharide extracted from brown algae. It can form a dense polysaccharide film at the gas-liquid interface through the interaction of carboxyl groups with hydrogen bonds in water molecules. Gum arabic has a molecular structure that combines "polysaccharide backbone" and "short branches" and contains a small amount of protein fragments. The protein fragments have certain surface activity and can be preferentially adsorbed at the gas-liquid interface. Through the directional arrangement of "hydrophobic groups facing the bubble interior and hydrophilic groups facing the water phase", a composite interfacial film combining polysaccharide and protein is formed.

[0059] The foam stabilizer is hydrophilic nano-silica, and its mass percentage in the water-based gel foam is 0-0.5%.

[0060] The role of foam stabilizers is to enhance foam stability, prolong foam exudation time, and enable foam to exist for a longer period of time. Hydrophilic nano-silica, with its abundant hydroxyl groups on its surface, combines with aqueous phase, foaming agent, and gelling agent molecules through hydrogen bonds, and is directionally adsorbed at the gas-liquid interface to form a "nanoparticle-surfactant" composite film. This film strengthens the bubble walls to improve mechanical strength and inhibits liquid drainage. Furthermore, the uniformly dispersed nanoparticles form physical barriers between bubbles through steric hindrance, preventing bubble aggregation and slowing down gas diffusion to inhibit Ostwald curing and maintain foam size uniformity. At the same time, it can also act as a crosslinking point to combine with the three-dimensional gel network of the gelling agent, enhancing network rigidity and anti-shrinkage ability, reducing the risk of bubbles being squeezed and ruptured due to gel shrinkage, significantly extending foam life and improving stability.

[0061] The antifreeze agent is ethylene glycol, which accounts for 0.15% of the mass of the water-based gel foam; the humectant is glycerol, which accounts for 0.2% of the mass of the water-based gel foam; and the cosolvent is ethylene glycol butyl ether, which accounts for 0.1% of the mass of the water-based gel foam.

[0062] Ethylene glycol is mainly used to improve the antifreeze properties of foam and prevent it from freezing; glycerol can increase the saturated vapor pressure of the solvent and prevent the evaporation of water in the foam solution; ethylene glycol butyl ether, as a solvent, helps to dissolve various components and ensures that various reagents can be fully dissolved.

[0063] The performance and effects of the water-based gel foam in this invention will be further verified through examples, comparative examples, and test examples below;

[0064] Example 1:

[0065] This embodiment discloses a water-based gel foam for blocking volatile organic compounds, which is composed of a composite foaming agent, a gelling agent, a foam stabilizer, an antifreeze agent, a humectant, a cosolvent, and water. The mass percentages of each component are as follows: composite foaming agent 0.1%, gelling agent 0.2%, foam stabilizer 0.2%, antifreeze agent 0.15%, humectant 0.2%, cosolvent 0.1%, and the balance is water.

[0066] The composite foaming agent used is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate and alkyl glycoside in a mass ratio of 7:3; the gelling agent is xanthan gum; the foam stabilizer is hydrophilic nano silica; the antifreeze agent is ethylene glycol; the humectant is glycerol; and the cosolvent is ethylene glycol butyl ether.

[0067] This embodiment also discloses a method for preparing the above-mentioned water-based gel foam, including the following steps:

[0068] The first step is to prepare the foam components;

[0069] S1: Weigh 0.3g of ethylene glycol, 0.4g of glycerol and 0.2g of ethylene glycol butyl ether using an electronic balance and pour them into a beaker containing 98.5g of water. Stir well and dissolve completely in the water.

[0070] S2: Weigh 0.14g of sodium fatty alcohol polyoxyethylene ether sulfate and 0.06g of alkyl glycoside using an electronic balance, then pour them into the aqueous solution containing the above ingredients, stir until completely dissolved, and obtain the foam component;

[0071] S3: Weigh 0.4g of hydrophilic nano-silica using an electronic balance, pour it into an aqueous solution containing foam components, and stir until completely dissolved.

[0072] The second step is to prepare the gel components;

[0073] S1: Weigh 0.4g of xanthan gum using an electronic balance and pour it into a beaker containing 99.6g of water while stirring. Stir until completely dissolved to obtain the gel component.

[0074] The third step is to mix the foam components and the gel components;

[0075] Pour the foam component completely into the gel component, stir it evenly, and after thorough mixing, pour it into a foaming device for foaming to obtain water-based gel foam.

[0076] Example 2:

[0077] This embodiment discloses a water-based gel foam for blocking volatile organic compounds, which is composed of a composite foaming agent, a gelling agent, a foam stabilizer, an antifreeze agent, a humectant, a cosolvent, and water; the mass percentage of each component is as follows: composite foaming agent 0.1%, gelling agent 0.2%, foam stabilizer 0.3%, antifreeze agent 0.15%, humectant 0.2%, cosolvent 0.1%, and the balance is water.

[0078] The composite foaming agent used is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate and alkyl glycoside in a mass ratio of 7:3; the gelling agent is xanthan gum; the foam stabilizer is hydrophilic nano silica; the antifreeze agent is ethylene glycol; the humectant is glycerol; and the cosolvent is ethylene glycol butyl ether.

[0079] This embodiment also discloses a method for preparing the above-mentioned water-based gel foam, including the following steps:

[0080] The first step is to prepare the foam components;

[0081] S1: Weigh 0.3g of ethylene glycol, 0.4g of glycerol and 0.2g of ethylene glycol butyl ether using an electronic balance and pour them into a beaker containing 98.3g of water. Stir well and dissolve completely in the water.

[0082] S2: Weigh 0.14g of sodium fatty alcohol polyoxyethylene ether sulfate and 0.06g of alkyl glycoside using an electronic balance, then pour them into the aqueous solution containing the above ingredients, stir until completely dissolved, and obtain the foam component;

[0083] S3: Weigh 0.6g of hydrophilic nano-silica using an electronic balance, pour it into an aqueous solution containing foam components, and stir until completely dissolved.

[0084] The second step is to prepare the gel components;

[0085] S1: Weigh 0.4g of xanthan gum using an electronic balance and pour it into a beaker containing 99.6g of water while stirring. Stir until completely dissolved to obtain the gel component.

[0086] The third step is to mix the foam components and the gel components;

[0087] Pour the foam component completely into the gel component, stir it evenly, and after thorough mixing, pour it into a foaming device for foaming to obtain water-based gel foam.

[0088] Example 3:

[0089] This embodiment discloses a water-based gel foam for blocking volatile organic compounds, which is composed of a composite foaming agent, a gelling agent, a foam stabilizer, an antifreeze agent, a humectant, a cosolvent, and water. The mass percentages of each component are as follows: composite foaming agent 0.1%, gelling agent 0.2%, foam stabilizer 0.4%, antifreeze agent 0.15%, humectant 0.2%, cosolvent 0.1%, and the balance is water.

[0090] The composite foaming agent used is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate and alkyl glycoside in a mass ratio of 7:3; the gelling agent is xanthan gum; the foam stabilizer is hydrophilic nano silica; the antifreeze agent is ethylene glycol; the humectant is glycerol; and the cosolvent is ethylene glycol butyl ether.

[0091] This embodiment also discloses a method for preparing the above-mentioned water-based gel foam, including the following steps:

[0092] The first step is to prepare the foam components;

[0093] S1: Weigh 0.3g of ethylene glycol, 0.4g of glycerol and 0.2g of ethylene glycol butyl ether using an electronic balance and pour them into a beaker containing 98.1g of water. Stir well and dissolve completely in the water.

[0094] S2: Weigh 0.14g of sodium fatty alcohol polyoxyethylene ether sulfate and 0.06g of alkyl glycoside using an electronic balance, then pour them into the aqueous solution containing the above ingredients, stir until completely dissolved, and obtain the foam component;

[0095] S3: Weigh 0.8g of hydrophilic nano-silica using an electronic balance, pour it into an aqueous solution containing foam components, and stir until completely dissolved.

[0096] The second step is to prepare the gel components;

[0097] S1: Weigh 0.4g of xanthan gum using an electronic balance and pour it into a beaker containing 99.6g of water while stirring. Stir until completely dissolved to obtain the gel component.

[0098] The third step is to mix the foam components and the gel components;

[0099] Pour the foam component completely into the gel component, stir it evenly, and after thorough mixing, pour it into a foaming device for foaming to obtain water-based gel foam.

[0100] Example 4:

[0101] This embodiment discloses a water-based gel foam for blocking volatile organic compounds, which is composed of a composite foaming agent, a gelling agent, a foam stabilizer, an antifreeze agent, a humectant, a cosolvent, and water; the mass percentage of each component is as follows: composite foaming agent 0.1%, gelling agent 0.2%, foam stabilizer 0.3%, antifreeze agent 0.15%, humectant 0.2%, cosolvent 0.1%, and the balance is water.

[0102] The composite foaming agent used is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate and dodecyl dimethyl betaine in a mass ratio of 9:1; the gelling agent is xanthan gum; the foam stabilizer is hydrophilic nano silica; the antifreeze agent is ethylene glycol; the humectant is glycerol; and the cosolvent is ethylene glycol butyl ether.

[0103] This embodiment also discloses a method for preparing the above-mentioned water-based gel foam, including the following steps:

[0104] The first step is to prepare the foam components;

[0105] S1: Weigh 0.3g of ethylene glycol, 0.4g of glycerol and 0.2g of ethylene glycol butyl ether using an electronic balance and pour them into a beaker containing 98.3g of water. Stir well and dissolve completely in the water.

[0106] S2: Weigh 0.18g of sodium fatty alcohol polyoxyethylene ether sulfate and 0.02g of dodecyl dimethyl betaine using an electronic balance, then pour them into the aqueous solution containing the above ingredients, stir until completely dissolved, and obtain the foam component.

[0107] S3: Weigh 0.6g of hydrophilic nano-silica using an electronic balance, pour it into an aqueous solution containing foam components, and stir until completely dissolved.

[0108] The second step is to prepare the gel components;

[0109] S1: Weigh 0.4g of xanthan gum using an electronic balance and pour it into a beaker containing 99.6g of water while stirring. Stir until completely dissolved to obtain the gel component.

[0110] The third step is to mix the foam components and the gel components;

[0111] Pour the foam component completely into the gel component, stir it evenly, and after thorough mixing, pour it into a foaming device for foaming to obtain water-based gel foam.

[0112] Example 5:

[0113] This embodiment discloses a water-based gel foam for blocking volatile organic compounds, which is composed of a composite foaming agent, a gelling agent, a foam stabilizer, an antifreeze agent, a humectant, a cosolvent, and water; the mass percentage of each component is as follows: composite foaming agent 0.1%, gelling agent 0.2%, foam stabilizer 0.3%, antifreeze agent 0.15%, humectant 0.2%, cosolvent 0.1%, and the balance is water.

[0114] The composite foaming agent used is a mixture of hexadecyltrimethylammonium bromide and alkyl glycoside in a mass ratio of 9:1; the gelling agent is xanthan gum; the foam stabilizer is hydrophilic nano-silica; the antifreeze agent is ethylene glycol; the humectant is glycerol; and the cosolvent is ethylene glycol butyl ether.

[0115] This embodiment also discloses a method for preparing the above-mentioned water-based gel foam, including the following steps:

[0116] The first step is to prepare the foam components;

[0117] S1: Weigh 0.3g of ethylene glycol, 0.4g of glycerol and 0.2g of ethylene glycol butyl ether using an electronic balance and pour them into a beaker containing 98.3g of water. Stir well and dissolve completely in the water.

[0118] S2: Weigh 0.18g of cetyltrimethylammonium bromide and 0.02g of alkyl glycoside using an electronic balance, then pour them into the aqueous solution containing the above ingredients, stir until completely dissolved, and obtain the foam component;

[0119] S3: Weigh 0.6g of hydrophilic nano-silica using an electronic balance, pour it into an aqueous solution containing foam components, and stir until completely dissolved.

[0120] The second step is to prepare the gel components;

[0121] S1: Weigh 0.4g of xanthan gum using an electronic balance and pour it into a beaker containing 99.6g of water while stirring. Stir until completely dissolved to obtain the gel component.

[0122] The third step is to mix the foam components and the gel components;

[0123] Pour the foam component completely into the gel component, stir it evenly, and after thorough mixing, pour it into a foaming device for foaming to obtain water-based gel foam.

[0124] Example 6:

[0125] This embodiment discloses a water-based gel foam for blocking volatile organic compounds, which is composed of a composite foaming agent, a gelling agent, a foam stabilizer, an antifreeze agent, a humectant, a cosolvent, and water; the mass percentage of each component is as follows: composite foaming agent 0.1%, gelling agent 0.2%, foam stabilizer 0.3%, antifreeze agent 0.15%, humectant 0.2%, cosolvent 0.1%, and the balance is water.

[0126] The composite foaming agent used is a mixture of hexadecyltrimethylammonium bromide and dodecyldimethyl betaine in a mass ratio of 8:2; the gelling agent is xanthan gum; the foam stabilizer is hydrophilic nano-silica; the antifreeze agent is ethylene glycol; the humectant is glycerol; and the cosolvent is ethylene glycol butyl ether.

[0127] This embodiment also discloses a method for preparing the above-mentioned water-based gel foam, including the following steps:

[0128] The first step is to prepare the foam components;

[0129] S1: Weigh 0.3g of ethylene glycol, 0.4g of glycerol and 0.2g of ethylene glycol butyl ether using an electronic balance and pour them into a beaker containing 98.3g of water. Stir well and dissolve completely in the water.

[0130] S2: Weigh 0.16g of hexadecyltrimethylammonium bromide and 0.04g of dodecyldimethyl betaine using an electronic balance, then pour them into the aqueous solution containing the above ingredients, stir until completely dissolved, and obtain the foam component;

[0131] S3: Weigh 0.6g of hydrophilic nano-silica using an electronic balance, pour it into an aqueous solution containing foam components, and stir until completely dissolved.

[0132] The second step is to prepare the gel components;

[0133] S1: Weigh 0.4g of xanthan gum using an electronic balance and pour it into a beaker containing 99.6g of water while stirring. Stir until completely dissolved to obtain the gel component.

[0134] The third step is to mix the foam components and the gel components;

[0135] Pour the foam component completely into the gel component, stir it evenly, and after thorough mixing, pour it into a foaming device for foaming to obtain water-based gel foam.

[0136] Comparative Example 1:

[0137] The comparative example consists of a composite foaming agent, an antifreeze agent, a humectant, a cosolvent, and water; the mass percentages of each component are: 0.1% composite foaming agent, 0.15% antifreeze agent, 0.2% humectant, 0.1% cosolvent, and the balance being water.

[0138] The composite foaming agent used is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate and alkyl glycoside in a mass ratio of 7:3; the antifreeze agent is ethylene glycol; the humectant is glycerol; and the cosolvent is ethylene glycol butyl ether.

[0139] Meanwhile, a comparative example also discloses a method for preparing the above-mentioned water-based gel foam, including the following steps:

[0140] S1: Weigh 0.3g of ethylene glycol, 0.4g of glycerol and 0.2g of ethylene glycol butyl ether using an electronic balance and pour them into a beaker containing 198.9g of water. Stir well and dissolve completely in the water.

[0141] S2: Weigh 0.14g of sodium fatty alcohol polyoxyethylene ether sulfate and 0.06g of alkyl glycoside using an electronic balance, then pour them into the aqueous solution containing the above ingredients, stir until completely dissolved, and obtain the foam component;

[0142] S3: Pour the foam components into a foaming device for foaming to obtain water-based gel foam.

[0143] Comparative Example 2:

[0144] The comparative example consists of a composite foaming agent, a gelling agent, an antifreeze agent, a humectant, a cosolvent, and water; the mass percentages of each component are: composite foaming agent 0.1%, gelling agent 0.2%, foam stabilizer 0.3%, antifreeze agent 0.15%, humectant 0.2%, cosolvent 0.1%, and the balance being water.

[0145] The composite foaming agent used is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate and alkyl glycoside in a mass ratio of 7:3; the gelling agent is xanthan gum; the foam stabilizer is commercially available ordinary silica; the antifreeze agent is ethylene glycol; the humectant is glycerol; and the cosolvent is ethylene glycol butyl ether.

[0146] This embodiment also discloses a method for preparing the above-mentioned water-based gel foam, including the following steps:

[0147] The first step is to prepare the foam components;

[0148] S1: Weigh 0.3g of ethylene glycol, 0.4g of glycerol and 0.2g of ethylene glycol butyl ether using an electronic balance and pour them into a beaker containing 98.3g of water. Stir well and dissolve completely in the water.

[0149] S2: Weigh 0.14g of sodium fatty alcohol polyoxyethylene ether sulfate and 0.06g of alkyl glycoside using an electronic balance, then pour them into the aqueous solution containing the above ingredients, stir until completely dissolved, and obtain the foam component;

[0150] S3: Weigh 0.6g of commercially available ordinary silica using an electronic balance, pour it into an aqueous solution containing foam components, and stir until completely dissolved;

[0151] The second step is to prepare the gel components;

[0152] S1: Weigh 0.4g of xanthan gum using an electronic balance and pour it into a beaker containing 99.6g of water while stirring. Stir until completely dissolved to obtain the gel component.

[0153] The third step is to mix the foam components and the gel components;

[0154] Pour the foam component completely into the gel component, stir it evenly, and after thorough mixing, pour it into a foaming device for foaming to obtain water-based gel foam.

[0155] Comparative Example 3:

[0156] The comparative example consists of a composite foaming agent, a gelling agent, an antifreeze agent, a humectant, a cosolvent, and water; the mass percentages of each component are: composite foaming agent 0.1%, gelling agent 0.3%, foam stabilizer 0.2%, antifreeze agent 0.15%, humectant 0.2%, cosolvent 0.1%, and the balance being water.

[0157] The composite foaming agent used is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate and alkyl glycoside in a mass ratio of 7:3; the gelling agent is sodium alginate; the foam stabilizer is carboxymethyl cellulose; the antifreeze agent is ethylene glycol; the humectant is glycerol; and the cosolvent is ethylene glycol butyl ether.

[0158] This embodiment also discloses a method for preparing the above-mentioned water-based gel foam, including the following steps:

[0159] The first step is to prepare the foam components;

[0160] S1: Weigh 0.3g of ethylene glycol, 0.4g of glycerol and 0.2g of ethylene glycol butyl ether using an electronic balance and pour them into a beaker containing 98.5g of water. Stir well and dissolve completely in the water.

[0161] S2: Weigh 0.14g of sodium fatty alcohol polyoxyethylene ether sulfate and 0.06g of alkyl glycoside using an electronic balance, then pour them into the aqueous solution containing the above ingredients, stir until completely dissolved, and obtain the foam component;

[0162] S3: Weigh 0.4g of carboxymethyl cellulose using an electronic balance, pour it into an aqueous solution containing the foaming component, and stir until completely dissolved.

[0163] The second step is to prepare the gel components;

[0164] S1: Weigh 0.6g of sodium alginate using an electronic balance and pour it into a beaker containing 99.4g of water while stirring. Stir until completely dissolved to obtain the gel component.

[0165] The third step is to mix the foam components and the gel components;

[0166] Pour the foam component completely into the gel component, stir it evenly, and after thorough mixing, pour it into a foaming device for foaming to obtain water-based gel foam.

[0167] Comparative Example 4:

[0168] The comparative example consists of a composite foaming agent, a gelling agent, an antifreeze agent, a humectant, a cosolvent, and water; the mass percentages of each component are: composite foaming agent 0.1%, gelling agent 0.3%, foam stabilizer 0.3%, antifreeze agent 0.15%, humectant 0.2%, cosolvent 0.1%, and the balance being water.

[0169] The composite foaming agent used is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate and alkyl glycoside in a mass ratio of 7:3; the gelling agent is gum arabic; the foam stabilizer is hydroxypropyl guar gum; the antifreeze agent is ethylene glycol; the humectant is glycerol; and the cosolvent is ethylene glycol butyl ether.

[0170] This embodiment also discloses a method for preparing the above-mentioned water-based gel foam, including the following steps:

[0171] The first step is to prepare the foam components;

[0172] S1: Weigh 0.3g of ethylene glycol, 0.4g of glycerol and 0.2g of ethylene glycol butyl ether using an electronic balance and pour them into a beaker containing 98.3g of water. Stir well and dissolve completely in the water.

[0173] S2: Weigh 0.14g of sodium fatty alcohol polyoxyethylene ether sulfate and 0.06g of alkyl glycoside using an electronic balance, then pour them into the aqueous solution containing the above ingredients, stir until completely dissolved, and obtain the foam component;

[0174] S3: Weigh 0.6g of hydroxypropyl guar gum using an electronic balance, pour it into an aqueous solution containing the foaming component, and stir until completely dissolved.

[0175] The second step is to prepare the gel components;

[0176] S1: Weigh 0.6g of gum arabic using an electronic balance and pour it into a beaker containing 99.4g of water while stirring. Stir until completely dissolved to obtain the gel component.

[0177] The third step is to mix the foam components and the gel components;

[0178] Pour the foam component completely into the gel component, stir it evenly, and after thorough mixing, pour it into a foaming device for foaming to obtain water-based gel foam.

[0179] Test Example 1

[0180] The water-based gel foam compositions prepared in Examples 1-6 and Comparative Examples 1-4 were tested for foam viscosity, foam volume, liquid discharge half-life, FC and MD parameters.

[0181] Viscosity was measured using an NDJ-5S rotational viscometer. A suitable rotor speed was selected for the viscosity measurement. The prepared gel foam composition was placed in a beaker, and the rotor was fully submerged in the foam before the viscosity measurement began. Once the reading on the viscosity counter screen stabilized, the reading was recorded as the viscosity of the foam. The measurement was repeated three times, and the average value was taken as the final result.

[0182] A foam scanner, purchased from Teclis GmbH, France (model: FOAMSCAN), was used to test foam volume and dissipation half-life performance. The system features a temperature sensor at the bottom of the glass container to monitor temperature changes during the experiment. Before the experiment, a certain amount of solution was injected into the sample chamber via an injection device. Air was then blown into the sample chamber through the bottom of the glass container, causing the solution to form foam. As the foam accumulated and rose within the glass container, five electrodes distributed at different heights measured the liquid volume using conductivity. The top four electrodes measured the liquid volume contained within the foam, while the bottom electrode specifically measured the solution volume. Simultaneously, a CCD camera was used to capture and record the morphological changes during bubble formation, and the bubble size data was analyzed in detail using accompanying CSA software.

[0183] During testing, a solution volume of 60 mL was injected into the electrode channel, and the air flow rate was 80 mL / min. Foam performance was tested using the blowing method. A foam scanner automatically measured parameters such as foam volume, foam liquid content at different heights, Foam Capacity (FC), Foam Maximum Density (MD), and Bikerman Index (IB). A CCD camera took an image every 10 seconds. Each solution was tested three times, and the average value was used as the final result. The foaming time was set to 120 seconds. The foam volume was used to characterize the foaming ability of different solutions; a larger volume indicated stronger foaming ability. The change in foam liquid content over time could be used to study the foam's liquid-carrying capacity and half-life.

[0184]

[0185] In the formula: FC represents the foaming capacity of the solution; Vf foamVf represents the foaming volume of the solution, in mL; gas The volume of air required for foaming, mL

[0186]

[0187] In the formula: MD is the maximum density of the foam; Vil iq Vf represents the initial solution volume, in mL; liq Vf represents the final solution volume, in mL; foam The volume of the solution that foams is mL.

[0188] To comprehensively consider the impact of foaming capacity and liquid-carrying half-life on foam performance, a comprehensive foam index is used to evaluate the overall foam performance of the compound solution. The formula is as follows:

[0189] FCI=0.75V A T 1 / 2

[0190] In the formula, FCI is the foam index, in mL; V A T is the foaming volume per unit time, in mL / s. 1 / 2 The half-life of the foam drainage is s.

[0191] The test data results are shown in Table 1.

[0192] Table 1

[0193] Foam viscosity / mPa.s 120s foaming volume / ml Drainage half-life / s Bubble Composite Index Example 1 152.8 194 26876 32587.2 Example 2 165.5 187 28910 33788.6 Example 3 178.8 175 29638 32416.6 Example 4 170.5 210 27100 35568.8 Example 5 184.6 205 29511 37811.0 Example 6 178.2 182 28520 32441.5 Comparative Example 1 32.5 225 14050 19757.8 Comparative Example 2 141.5 211 16050 21165.9 Comparative Example 3 83.5 208 14332 18631.6 Comparative Example 4 94.2 181 16573 18748.2

[0194] As shown in Table 1, adding xanthan gum as a gelling agent and a self-made hydrophilic nano-silica material with a foam stabilizer significantly prolongs the foam half-life, enhances foam stability, and substantially improves the overall foam index. Test Example 2

[0195] The barrier effect of water-based gel foam prepared in Examples 2 / 4-6 on toluene was studied. First, the foam prepared in Example 6 was designated as Case 1, the foam prepared in Example 4 as Case 2, the foam prepared in Example 5 as Case 3, and the foam prepared in Example 2 as Case 4. Before each experiment, 2L of the prepared foam stock solution was added to a storage tank. Powered by an air compressor, the premixed foam in the storage tank was pumped into the pipeline. The driving pressure of the air compressor was set to 3.0MPa using a pressure regulating valve to ensure sufficient foam formation. The soil was dried in a drying oven at 400℃ for 4 hours and then removed. Deionized water was then added to control the moisture content to approximately 20%. Two custom-made adsorption columns, labeled A and B, were used. The treated soil was placed in the adsorption columns, with a soil layer height of 10cm. The foamed foam was immediately applied to the soil on adsorption column A to a height of 15cm, while adsorption column B was left untreated. Toluene was then injected into the soil using a syringe. The concentration of volatile organic compounds (VOCs) in adsorption columns A and B was monitored in real time using a VOCs detector. These concentrations were denoted as C and C, respectively. a C b The blocking rate (η) at time i is calculated using the following formula. i ):

[0196]

[0197] In the formula, η i For barrier efficiency, %; C ai C bi , , represent the concentrations at time i of adsorption columns A and B, respectively, in ppm.

[0198] Test results are as follows Figure 1 and Figure 2 As shown, the foams formed in all four embodiments exhibited significant blocking effects against toluene. The foam material coverage rapidly reduced the toluene concentration, maintaining it below 7.0 ppm within 18 hours. Case 3 demonstrated superior blocking performance, with the toluene concentration decreasing to 4.2 ppm after 1 hour (a blocking rate of 96.5%), and reaching a minimum concentration of 1.2 ppm after 12 hours. The toluene blocking performance of the four foams was, in descending order: Case 3 > Case 4 > Case 2 > Case 1.

[0199] Test Example 3

[0200] This test case is basically conducted in the same manner as Test Case 2, except that the volatile organic compound being tested is replaced with ethyl acetate.

[0201] Test results are as follows Figure 3 and Figure 4As shown, the foams formed in all four examples exhibited significant blocking effects against ethyl acetate. Case 3 showed the best blocking effect, with the ethyl acetate concentration decreasing to 8.8 ppm after 1 hour (blocking rate reaching 95.0%), and the concentration reaching a minimum of 3.0 ppm after 8 hours. The blocking performance of the four foams against ethyl acetate was, in descending order: Case 3 > Case 1 > Case 2 > Case 4.

[0202] Test Example 4

[0203] This test case is basically conducted in the same manner as Test Case 2, except that the volatile organic compound being tested is replaced with xylene.

[0204] Test results are as follows Figure 5 and Figure 6 As shown, the foams formed in all four examples exhibited significant blocking effects against ethyl acetate, and the coverage of the foam material rapidly reduced the concentration. Case 3 showed the best blocking effect, with the xylene concentration decreasing to 6.8 ppm after 1 hour (blocking rate reaching 95.5%), and the xylene concentration reaching a minimum of 2.9 ppm after 8 hours. The blocking performance of the four foams against xylene was, in descending order: Case 3 > Case 1 > Case 2 > Case 4.

Claims

1. A water-based gel foam for blocking volatile organic compounds, characterized by: The water-based gel foam is composed of a composite foaming agent, a gelling agent, a foam stabilizer, an antifreeze agent, a humectant, a co-solvent, and water. The mass fraction of each component is as follows: composite foaming agent 0.001-0.5%, gelling agent 0.1-0.5%, foam stabilizer 0-0.5%, antifreeze agent 0.15%, humectant 0.2%, co-solvent 0.1%, and the balance is water. The composite foaming agent is prepared by compounding sodium fatty alcohol polyoxyethylene ether sulfate or hexadecyltrimethylammonium bromide with alkyl glycoside or dodecyl dimethyl betaine in pairs at a ratio of 7:3 to 9:

1. The foam stabilizer is a hydrophilic nano-silica prepared by plasma treatment. The preparation steps are as follows: S1. Disperse hydrophobic nano-silica evenly in an appropriate amount of anhydrous ethanol, and sonicate for 30 minutes to form a uniform suspension.

2. Use a dropper to evenly apply the nano-silica suspension onto a glass slide; S3. Place the glass slide coated with nano-silica in a 60℃ constant temperature drying oven and dry for 12 hours; S4. Place the glass slide into the processing chamber of the plasma cleaner; S5. Start the vacuum pump to evacuate the processing chamber to a certain vacuum level. Then introduce oxygen into the processing chamber and adjust the gas flow rate to 30 sccm. Set the equipment power to 150W and the processing time to 20 minutes. S6. Start the plasma generator so that the active particles in the plasma generated in the chamber react with the hydrophobic groups on the surface of the hydrophobic nano-silica, destroying the hydrophobic structure and introducing the hydrophilic hydroxyl group. S7. After the processing time is over and the pressure in the chamber returns to normal, remove the processed sample. S8. The modified silica was pressed into sheets, and the water contact angle was measured using an interfacial rheometer. The contact angle was less than 30°, indicating that the hydrophilic nano silica was successfully prepared.

2. The water-based gel foam for blocking volatile organic compounds as described in claim 1, characterized in that: The mass fractions of each component in the water-based gel foam are as follows: 0.1% composite foaming agent, 0.2% gelling agent, 0.3% foam stabilizer, 0.15% antifreeze agent, 0.2% humectant, 0.1% cosolvent, and the balance being water.

3. The water-based gel foam as described in claim 2, characterized in that: The gelling agent is one or a combination of xanthan gum, sodium alginate, and gum arabic.

4. The water-based gel foam as described in claim 1, characterized in that: The composite foaming agent is selected as a mixture of sodium fatty alcohol polyoxyethylene ether sulfate and alkyl glycoside in a ratio of 7:

3.

5. The water-based gel foam as described in claim 1, characterized in that: The antifreeze agent is ethylene glycol, the humectant is glycerol, and the cosolvent is ethylene glycol butyl ether.

6. The water-based gel foam as described in claim 1, characterized in that, The method for preparing the water-based gel foam includes the following preparation steps: S1. Prepare foam components; S2. Preparation of gel components; S3. Mix the foam component and gel component and stir evenly. Pour the mixture into a foaming device and perform a foaming operation to obtain the prepared water-based gel foam.

7. The water-based gel foam as described in claim 6, characterized in that: Step S1 includes the following steps: S11. Weigh out ethylene glycol butyl ether, glycerol and ethylene glycol in proportion, add them to a beaker containing water in sequence, stir well and let them dissolve completely. S12. Prepare composite foaming agents according to the proportions, pour the obtained composite foaming agents into a beaker containing antifreeze, humectant and solubilizer, stir evenly to obtain foam components; S13. Weigh out the hydrophilic nano-silica according to the proportion, add it to the beaker containing the foam component and stir evenly.

8. A water-based gel foam for blocking volatile organic compounds as described in claim 6, characterized in that: Step S2 includes the following steps: S21. Weigh out a certain amount of water according to the proportion and add it to the beaker; S22. Weigh xanthan gum, sodium alginate, and gum arabic according to the proportions, and slowly add them to three beakers containing water while stirring during the addition process to obtain the gel component.

9. The application of the water-based gel foam as described in claim 2 in emergency control of leaks of volatile organic compounds such as toluene, ethyl acetate, and xylene, characterized in that: When applying, the water-based gel foam is evenly covered on the surface of the area containing volatile organic compounds, and the foam coverage height is controlled to be 15cm.

10. An experimental barrier device for blocking volatile organic compounds using water-based gel foam, characterized in that: The experimental barrier device consists of an air compressor, a pressure regulating valve, a liquid storage tank, a liquid syringe, a constant temperature water bath, a pressure sensor, a temperature sensor, a VOCs detector, and an adsorption column.

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