Redox response type cross-linked silicon paste containing fullerene and ferrocene group as well as preparation method and application of redox response type cross-linked silicon paste

Abstract

The invention relates to the technical field of novel organic silicon materials and fine chemical engineering, in particular to redox response type cross-linked silicon paste containing fullerene and ferrocene groups as well as a preparation method and application of the redox response type cross-linked silicon paste. The preparation method of the cross-linked silicon paste comprises the following steps: adding a vinyl modified filler, a fullerene cross-linking agent and a resin cross-linking agent into carrier oil under a stirring condition, mixing, adding a catalyst, and carrying out a hydrosilylation reaction to form primary cross-linked silicon paste particles with an interpenetrating network structure; and adding a functional end-capping reagent and a catalyst, continuously reacting, and adding carrier oil after the reaction is finished. The cross-linking density is controllable, the mechanical strength is high, the surface hydrophilic and hydrophobic intelligent switching function is achieved, and intelligent conversion of hydrophilic easy emulsification during processing and hydrophobic strong foam inhibition during use is achieved. The organic silicon defoaming agent is applied to a defoaming agent, hydrophilic in an oxidation state assists emulsification, hydrophobic in a reduction state assists foam inhibition, and the contradiction that the emulsification stability and the foam inhibition durability of a traditional organic silicon defoaming agent are difficult to consider at the same time is solved.

Description

A redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups, its preparation method and application Technical Field

[0001] This invention relates to the fields of organosilicon new materials and fine chemical technology, specifically to a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups, its preparation method and application. Background Technology

[0002] Organosilicon defoamers are widely used in textile printing and dyeing, papermaking and pulping, oil extraction and other fields due to their excellent defoaming performance and low surface tension. Currently, mainstream high-performance organosilicon defoamers are usually emulsified from a "silicone paste" composed of hydrophobic silica and silicone oil.

[0003] However, existing silicone defoamers present a contradiction between difficulty in emulsification and poor foam suppression. To achieve excellent foam suppression performance (long-lasting effect), silicone paste particles need to be highly hydrophobic; however, highly hydrophobic silicone paste is extremely difficult to emulsify, and the emulsion has poor stability, easily leading to oil drift and demulsification. To solve the emulsification problem, a large amount of emulsifier or the introduction of hydrophilic groups is usually required, but this significantly reduces the hydrophobicity of the silicone paste surface, thus sacrificing foam suppression performance. Moreover, under high shear stress, traditional silicone paste particles are prone to breakage and shrinkage, causing them to detach from the foam wall and lose their "bridging" foam-breaking ability, resulting in foam suppression failure. Existing silicone defoamers struggle to simultaneously possess both emulsification stability and long-lasting foam suppression performance. Summary of the Invention

[0004] To overcome the shortcomings and deficiencies of existing technologies, one of the objectives of this invention is to provide a method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups. This method utilizes vinyl-modified fillers, fullerene crosslinking agents with surface-modified silane-hydrogen bonds, vinyl-modified resin crosslinking agents, and functional end-capping agents to crosslink in a carrier oil via a hydrosilylation reaction. The crosslinking density is controllable, the mechanical strength is high, and it possesses intelligent switching functionality between hydrophilic and hydrophobic surfaces. This preparation method is simple to operate, easy to control, has high production efficiency, and low production cost, making it suitable for large-scale production.

[0005] The second objective of this invention is to provide a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups. By introducing fullerene to enhance the skeleton strength and utilizing the redox-responsive characteristics of ferrocene groups, a smart transformation is achieved that allows the paste to be "hydrophilic and easily emulsified during processing, and hydrophobic and strongly defoaming during use".

[0006] The third objective of this invention is to provide an application of a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups in the preparation of fast-acting and long-lasting defoaming agents. The hydrophilicity of the ferrocene groups in the oxidized state aids emulsification and dispersion, while their hydrophobicity in the reduced state enhances defoaming performance, thus resolving the contradiction between emulsification stability and long-lasting defoaming in traditional silicone defoamers. The resulting defoamer possesses advantages such as rapid defoaming, long defoaming time, high temperature resistance, and shear resistance, making it suitable for various harsh foaming systems.

[0007] One of the objectives of this invention is achieved through the following technical solution: a method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups, characterized by comprising the following steps: (S1) under argon protection, the temperature is raised to 60-120°C, and components A, B, and C are added to the carrier oil under stirring conditions, mixed and stirred for 0.5-1.5 h, then a caster catalyst is added, and a hydrosilylation reaction is carried out at 80-120°C, maintaining high-speed shear during the reaction, and the reaction is carried out for 3-5 h to form an interpenetrating network. (S2) Primary cross-linked silicone paste particles with a complex structure; Component D and a cassiterite catalyst are added to the primary cross-linked silicone paste particles, and the reaction is continued for 1.0-2.0 h. Then the temperature is raised to 140-160℃ for 1-3 h of curing reaction. After the reaction is completed, carrier oil is added, the temperature is lowered and the material is discharged to obtain a redox-responsive cross-linked silicone paste containing fullerene and ferrocene groups, abbreviated as fullerene-ferrocene-based cross-linked silicone paste; wherein, component A is a vinyl-modified filler, component B is a fullerene cross-linking agent, component C is a resin cross-linking agent, and component D is a functional end-capping agent.

[0008] The method for preparing redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups involves component A (hard core), component B (spherical), and component C (resin cluster) forming a complex chemical crosslinking network through siloxane segments, which endows the silicone paste with excellent viscoelasticity and film-forming properties and improves the defoaming efficiency. The "first crosslinking, then end-capping" process ensures that the ferrocene groups are mainly distributed on the outermost layer of the silicone paste particles, maximizing its efficiency in regulating surface properties.

[0009] Preferably, the carrier oil is dimethyl silicone oil or alkyl-modified silicone oil; the cassette catalyst is selected from a platinum catalyst with PT-1000ppm; component D is at least one of allyl ferrocene carboxylate, vinylferrocene, and 1,1'-bis(ferroceneyl)-1-butene; the amounts of each raw material by weight are as follows: 10-30 parts of carrier oil, 3-6 parts of component A, 5-30 parts of component B, 2-7 parts of component C, and 0.1-1.5 parts of cassette catalyst in step (S1); 2-10 parts of component D, 0.02-0.10 parts of cassette catalyst, and 20-60 parts of carrier oil in step (S2).

[0010] Using the above technical solution, component D contains a ferrocene group and has an unsaturated double bond. In step (S2), the double bond in component D reacts with the excess silane-hydrogen bonds remaining in the system to graft the ferrocene group onto the outermost surface of the primary cross-linked silicone paste particles. More preferably, the alkyl-modified silicone oil is a dodecyl-modified silicone oil.

[0011] Preferably, the preparation method of the vinyl-modified filler includes the following steps: (A1) Adding acetic acid to 60-100 parts by weight of deionized water to adjust the pH of the solution to 3-5, then adding 1.0-3.0 parts by weight of unsaturated double-bonded silane coupling agent, and stirring and hydrolyzing at room temperature for 30-50 min; (A2) Then adding 5.0-10.0 parts by weight of hydrophilic fumed silica, stirring and reacting in an oil bath at 60-80℃ for 1-6 h, and then... The filter cake was filtered through a microporous membrane and washed twice with water and twice with anhydrous ethanol. (A3) The filter cake was dried in a vacuum drying oven at 60℃ for 6-12 hours and then ground to obtain vinyl-modified filler (denoted as SiO2-C=C).

[0012] Using the above technical solution, hydrophilic fumed silica is reacted with an unsaturated double-bonded silane coupling agent. The siloxy groups of the unsaturated double-bonded silane coupling agent are condensed with the hydroxyl groups on the surface of silica to obtain modified silica with active double bonds on the surface, namely vinyl-modified filler, which introduces a novel nanomaterial reinforcement structure.

[0013] Preferably, the unsaturated double-bonded silane coupling agent is at least one selected from γ-methacryloyloxypropyltrimethoxysilane, vinyltris(2-methoxyethoxy)silane, vinyltrimethoxysilane, and methylvinyldimethoxysilane; the average particle size of the hydrophilic fumed silica is 10-30 nm, and more preferably, the hydrophilic fumed silica is selected from Degussa A200.

[0014] Preferably, the preparation method of the fullerene crosslinking agent includes the following steps: (B1) By weight, 0.2-0.5 parts of acrylic acid, 0.5-0.8 parts of fullerol, and 0.1-0.3 parts of catalyst 4-dimethylaminopyridine are added to 13-40 parts of anhydrous dichloromethane to dissolve the solid. The mixture is cooled to 0°C under ice bath conditions. Under stirring, 13-21 parts of anhydrous dichloromethane solution containing 0.2-1.0 parts of N,N'-dicyclohexylcarbodiimide are added dropwise over 2-10 minutes. The reaction is continued at 0°C for 10-30 minutes. The ice bath is then removed, and the reaction is stirred at room temperature for 10-72 hours. The reaction is monitored by thin-layer chromatography (TLC). The reaction process: After the reaction is completed, the reaction solution is concentrated under reduced pressure and purified by column chromatography to obtain a fullerene derivative containing double bonds (denoted as C60-C=C); (B2) Under argon protection, 5-60 parts of hydrogen-containing silicone oil at both ends, 0.2-0.9 parts of fullerene derivative containing double bonds and 0.010-0.500 parts of PT-1000ppm platinum catalyst are added to the reaction flask. After stirring at room temperature for 0.5-2.0h, the temperature is raised to 80-120℃ for 2-6h, and then the temperature is raised to 140-160℃ for 1-3h. After the reaction is completed and cooled, the fullerene crosslinking agent (denoted as C60-SO-SiH) is obtained.

[0015] Using the above technical solution, modified fullerenes containing a small amount of double bonds are subjected to a hydrosilylation reaction with an excess of double-ended hydrogen-containing silicone oil to obtain modified fullerenes with long-chain siloxane grafts on the surface and rich in Si-H bonds at the ends. The spherical structure of the fullerene introduced by component B serves as a physical crosslinking point and framework, significantly improving the mechanical strength of the silicone paste particles, making them less prone to breakage under high shear conditions, and greatly extending the foam suppression life.

[0016] Preferably, the hydrogen content of the double-ended hydrogen-containing silicone oil is 0.05-0.5 wt%.

[0017] Preferably, the preparation method of the resin crosslinking agent includes the following steps: (C1) By weight, under argon protection, 2.0-10.0 parts of hydrogen-containing MQ resin, 30-200 parts of double-ended vinyl silicone oil and 0.1-1.5 parts of PT-1000ppm platinum catalyst are mixed and stirred at room temperature for 0.5-3.0h to mix evenly; (C2) Heating to 80-120℃ for 2-6h, then heating to 140-160℃ for 1-3h, and cooling after the reaction to obtain the resin crosslinking agent (denoted as MQ-SO-C=C).

[0018] Preferably, the hydrogen content of the hydrogen-containing MQ resin is 0.18-1.5 wt%, and the vinyl content of the double-ended vinyl silicone oil is 0.05-0.4 wt%.

[0019] Using the above technical solution, low-hydrogen MQ silicone resin is reacted with an excess of double-ended vinyl silicone oil, so that long-chain siloxanes are grafted onto the surface of the MQ resin and the ends are rich in vinyl double bonds.

[0020] The second objective of this invention is achieved through the following technical solution: a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups, prepared by the above-mentioned method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups.

[0021] The third objective of this invention is achieved through the following technical solution: the application of the above-mentioned redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups, wherein the redox-responsive crosslinked silicone paste is used to prepare an organosilicon defoamer; the preparation method of the organosilicon defoamer includes the following steps: (R1) by weight, 15-35 parts of redox-responsive crosslinked silicone paste, 1-3 parts of Span emulsifier, and 1-3 parts of Tween emulsifier are added to a reaction vessel, and the mixture is heated at 25-8... At 0℃, add 20-50 parts of water containing 0.2-1.2 parts of oxidant, and use a high-speed homogenizer at 5000-12000 rpm for shearing emulsification for 30-120 minutes to obtain an emulsion; (R2) reduce the speed to 500-800 rpm, add 0.1-1.2 parts of cellulose thickener and 0.04-0.3 parts of reducing agent to the emulsion, and adjust the emulsion viscosity to 1000-5000 cSt to obtain an organosilicon defoamer.

[0022] The above technical solution cleverly resolves the contradiction between emulsification and dispersion and hydrophobic defoaming by utilizing the redox properties of ferrocene. The oxidized state is hydrophilic, aiding emulsification, while the reduced state is hydrophobic, aiding defoaming. Specifically, in step (R1), the emulsification stage involves emulsifying the cross-linked silicone paste and its compounded emulsifier in an aqueous system containing an oxidant (such as ferric sulfate). During this process, the ferrocene groups on the surface are oxidized to positively charged ferrocene onium ions (hydrophilic), significantly reducing the oil-water interfacial tension, promoting silicone paste dispersion, and obtaining an emulsion with uniform particle size and excellent stability. In step (R2), the activation stage involves adding a reducing agent (such as ascorbic acid) to the emulsion. The ferrocene onium ions are reduced to neutral ferrocene groups (hydrophobic), restoring the silicone paste particles to a highly hydrophobic state and thus activating their excellent defoaming properties.

[0023] More preferably, the Span-type emulsifier is at least one of Span-20, Span-40, Span-65, and Span-80; the Tween-type emulsifier is at least one of Tween-20, Tween-40, Tween-60, and Tween-80; the oxidant is at least one of ferric sulfate, ammonium persulfate, ferric chloride, hydrogen peroxide, and cerium ammonium nitrate; the reducing agent is at least one of aciduric acid, sodium borohydride, sodium sulfite, and sodium bisulfite; and the cellulose-based thickener is hydroxyethyl cellulose and / or hydroxypropyl methyl cellulose.

[0024] The beneficial effects of this invention are as follows: The preparation method of the redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups utilizes vinyl-modified fillers, fullerene crosslinking agents with surface-modified silane-hydrogen bonds, resin crosslinking agents with surface-modified vinyl groups, and functional end-capping agents to crosslink in a carrier oil via hydrosilylation reaction. The crosslinking density is controllable, the mechanical strength is high, and it possesses intelligent switching functionality between hydrophilic and hydrophobic surfaces. Component A (hard core), component B (spherical), and component C (resin cluster) form a complex chemical crosslinking network through siloxane segments, endowing the silicone paste with excellent viscoelasticity and film-forming properties, and improving defoaming efficiency. The "first crosslink, then end-cap" process ensures that the ferrocene groups are mainly distributed on the outermost layer of the silicone paste particles, maximizing their efficiency in regulating surface properties. This preparation method is simple to operate, easy to control, has high production efficiency, and low production cost, making it suitable for large-scale production.

[0025] The redox-responsive crosslinked silicone paste of the present invention, containing fullerene and ferrocene groups, enhances the backbone strength by introducing fullerene and utilizes the redox-responsive characteristics of ferrocene groups to achieve a smart transformation of "hydrophilic and easy emulsification during processing, and hydrophobic and strong foam suppression during use".

[0026] This invention relates to the application of a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups in the preparation of fast-acting and long-lasting defoaming agents. The hydrophilicity of the ferrocene groups in the oxidized state aids emulsification and dispersion, while their hydrophobicity in the reduced state enhances defoaming performance. This resolves the contradiction between emulsification stability and long-lasting defoaming in traditional silicone defoamers. The oxidized state's hydrophilicity aids emulsification, while the reduced state's hydrophobicity aids defoaming. The resulting defoamer possesses advantages such as rapid defoaming, long defoaming time, high temperature resistance, and shear resistance, making it suitable for various harsh foaming systems.

[0027] The defoaming speed mainly depends on whether the defoamer particles can quickly penetrate the foam film surface and spread rapidly, causing the film to rupture. This invention accelerates this process through the following mechanisms: "hydrophilic-assisted dispersion" (intelligent dispersion) in the oxidized state; and a special "fullerene + MQ resin" microstructure (efficient penetration). Foam suppression refers to the ability to prevent the formation of new foam over a long period, which is usually limited by the hydrophobicity and mechanical strength of the defoamer. This invention addresses these limitations through the following mechanisms: "hydrophobicity recovery" (intelligent locking) in the reduced state; the "mechanical reinforcement" effect of fullerene (shear resistance, high temperature resistance); and the "film-forming properties" (durable barrier) of the multi-crosslinked network. In short, this invention uses a chemical switch (ferrocene) to resolve the contradiction between dispersion and hydrophobicity, and physical reinforcement (fullerene) to solve the durability problem, thereby achieving a "fast and effective" defoaming effect. Attached Figure Description

[0028] Figure 1 is a structural schematic diagram of components A, B, C, and D, and component D based on the redox regulation mechanism of ferrocene groups, as described in Example 1 of the present invention; Figure 2 is a structural schematic diagram of the fullerene-ferrocene-based crosslinked silicone paste described in Example 1 of the present invention; Figure 3 is a schematic diagram of the synthesis route of component A described in Example 1 of the present invention; Figure 4 is a schematic diagram of the synthesis route of component B described in Example 1 of the present invention; Figure 5 is a schematic diagram of the synthesis route of component C described in Example 1 of the present invention; Figure 6 is a comparison diagram of the infrared spectra (FT-IR) of hydrophilic fumed silica, KH570, and component A described in Example 1 of the present invention; Figure 7 is a comparison diagram of the infrared spectra (FT-IR) of the double-bonded fullerene derivative, the hydrogen-containing silicone oil, and component B described in Example 1 of the present invention; Figure 8 is a comparison diagram of the infrared spectra (FT-IR) of the hydrogen-containing MQ resin and component C described in Example 1 of the present invention; Figure 9 is a thermogravimetric analysis (TG) curve of the fullerene-ferrocene-based crosslinked silicone paste described in Example 1 of the present invention. Detailed Implementation

[0029] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0030] Example 1, as shown in Figures 1-2, describes a method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups, comprising the following steps: (S1) Under argon protection, the temperature is raised to 90°C, and 4g of component A, 12g of component B, and 4g of component C are added to 20g of carrier oil under stirring. The mixture is stirred for 1 hour, and then 1.0g of caster catalyst is added. A hydrosilylation reaction is carried out at 100°C, with high-speed shear maintained during the reaction, for 4 hours to form primary crosslinked silicone paste particles with an interpenetrating network structure; (S2) 6g of component D and 0.06g of caster catalyst are added to the above primary crosslinked silicone paste particles, and the reaction continues for 1.5 hours. Then, the temperature is raised to 150°C for aging reaction for 2 hours. After the reaction is completed, 40g of caster catalyst is added to the primary crosslinked silicone paste particles. g carrier oil, cooled and discharged, yields a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups; wherein, component A is a vinyl-modified filler, component B is a fullerene crosslinking agent, component C is a resin crosslinking agent, and component D is a functional end-capping agent.

[0031] The carrier oil is dimethyl silicone oil; the cassette catalyst is selected from a platinum catalyst with a PT-1000ppm concentration; and component D is allyl ferrocene.

[0032] As shown in Figure 3, the preparation method of the vinyl-modified filler includes the following steps: (A1) Add 80 mL of deionized water to a 500 mL flask equipped with a magnetic stirrer, then add acetic acid to adjust the pH of the solution to 3-5, then add 2.0 g of unsaturated double-bonded silane coupling agent, and stir and hydrolyze at room temperature for 40 min; (A2) Then add 8.0 g of hydrophilic fumed silica (Degussa A200), stir and react for 4 h under 70℃ oil bath conditions, and then... The filter cake was filtered through a microporous membrane and washed twice with water and twice with anhydrous ethanol. (A3) The filter cake was dried in a vacuum drying oven at 60°C for 8 hours and then ground to obtain vinyl-modified filler.

[0033] The unsaturated double-bonded silane coupling agent is γ-methacryloyloxypropyltrimethoxysilane.

[0034] As shown in Figure 4, the preparation method of the fullerene crosslinking agent includes the following steps: (B1) In a dry 100 mL three-necked flask, add 0.3 g of acrylic acid, 0.6 g of fullerol and 0.2 g of catalyst 4-dimethylaminopyridine, and 20 mL of water. The solid was dissolved in mL of anhydrous dichloromethane and cooled to 0°C under ice bath conditions. 12 mL of anhydrous dichloromethane solution containing 0.6 g of N,N'-dicyclohexylcarbodiimide was added dropwise over 6 min with stirring. The reaction was maintained at 0°C for 20 min, then the ice bath was removed, and the reaction was stirred at room temperature for 24 h. The reaction progress was monitored by thin-layer chromatography (TLC). After the reaction was completed, the reaction solution was concentrated under reduced pressure and purified by column chromatography to obtain a fullerene derivative containing double bonds. (B2) Under argon protection, 30 g of hydrogen-terminated silicone oil, 0.6 g of a fullerene derivative containing double bonds, and 0.100 g of PT-1000 ppm platinum catalyst were added to the reaction flask. After stirring at room temperature for 1.0 h, the temperature was raised to 100°C for 4 h, and then further raised to 150°C for 2 h. After cooling, a fullerene crosslinking agent was obtained.

[0035] The hydrogen content of the double-ended hydrogen-containing silicone oil is 0.2 wt%.

[0036] As shown in Figure 5, the preparation method of the resin crosslinking agent includes the following steps: (C1) Under argon protection, 6.0g of hydrogen-containing MQ resin, 100g of double-ended vinyl silicone oil and 1.0g of PT-1000ppm platinum catalyst are added to the reaction flask and mixed. The mixture is stirred at room temperature for 1.0h to achieve uniform mixing; (C2) The mixture is heated to 100℃ and reacted for 4h, then heated to 150℃ and reacted for another 2h. After the reaction is completed and cooled, the resin crosslinking agent is obtained.

[0037] The hydrogen-containing MQ resin has a hydrogen content of 1 wt%, and the vinyl content of the double-ended vinyl silicone oil is 0.2 wt%.

[0038] The redox-responsive crosslinked silicone paste is used to prepare an organosilicon defoamer. The preparation method of the organosilicon defoamer includes the following steps: (R1) 25g of redox-responsive crosslinked silicone paste, 2g of Span emulsifier, and 2g of Tween emulsifier are added to a reaction vessel. Under the condition of 50°C, 35g of ultrapure water containing 1.0g of ferric sulfate oxidant is added. The mixture is sheared and emulsified at 8000rpm for 60min using a high-speed homogenizer to obtain an emulsion; (R2) The speed is reduced to 600rpm, and 0.8g of cellulose thickener and 0.1g of reducing agent oxalic acid are added to the emulsion to adjust the viscosity of the emulsion to 2000cSt to obtain the organosilicon defoamer.

[0039] The Span-type emulsifier is Span-20, the Tween-type emulsifier is Tween-20, and the cellulose-type thickener is hydroxyethyl cellulose.

[0040] Example 2: A method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups, comprising the following steps: (S1) Under argon protection, the temperature is raised to 60°C, and 3g of component A, 5g of component B, and 2g of component C are added to 10g of carrier oil under stirring. The mixture is stirred for 0.5h, and then 0.1g of caster catalyst is added. A hydrosilylation reaction is carried out at 80°C, with high-speed shearing maintained during the reaction. The reaction is carried out for 3h to form primary crosslinked silicone paste particles with an interpenetrating network structure; (S2) 2g of component D and 0.020g of caster catalyst are added to the above primary crosslinked silicone paste particles, and the reaction is continued for 1.0h. Then the temperature is raised to 140°C for aging reaction for 1h. After the reaction is completed, 20g of carrier oil is added, and the mixture is cooled and discharged to obtain a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups; wherein, component A is a vinyl-modified filler, component B is a fullerene crosslinking agent, component C is a resin crosslinking agent, and component D is a functional end-capping agent.

[0041] The carrier oil is dimethyl silicone oil; the cassette catalyst is selected from PT-1000ppm platinum catalyst; and component D is vinyl ferrocene.

[0042] The preparation method of the vinyl-modified filler includes the following steps: (A1) Add 60 mL of deionized water to a 500 mL flask equipped with a magnetic stirrer, then add acetic acid to adjust the pH of the solution to 3-5, then add 1.0 g of unsaturated double-bonded silane coupling agent, and stir and hydrolyze at room temperature for 30 min; (A2) Then add 5.0 g of hydrophilic fumed silica (Degussa A200), stir and react for 1 h in an oil bath at 60℃, and then... The filter cake was filtered through a microporous membrane and washed twice with water and twice with anhydrous ethanol. (A3) The filter cake was dried in a vacuum drying oven at 60°C for 6 hours and then ground to obtain vinyl-modified filler.

[0043] The unsaturated double-bonded silane coupling agent is vinyltris(2-methoxyethoxy)silane.

[0044] The preparation method of the fullerene crosslinking agent includes the following steps: (B1) In a dry 100 mL three-necked flask, 0.2 g of acrylic acid, 0.5 g of fullerol and 0.1 g of catalyst 4-dimethylaminopyridine are added to 10 mL of anhydrous dichloromethane to dissolve the solid. The mixture is cooled to 0 °C under ice bath conditions, and 10 mL of the solution is added dropwise over 2 min with stirring. mL of anhydrous dichloromethane solution containing 0.2 g N,N'-dicyclohexylcarbodiimide was reacted at 0℃ for 10 min, then the ice bath was removed, and the reaction was stirred at room temperature for 10 h. The reaction progress was monitored by thin-layer chromatography (TLC). After the reaction was completed, the reaction solution was concentrated under reduced pressure and purified by column chromatography to obtain a fullerene derivative containing double bonds; (B2) Under argon protection, 5 g of hydrogen-containing silicone oil, 0.2 g of fullerene derivative containing double bonds, and 0.010 g of PT-1000 ppm platinum catalyst were added to the reaction flask. After stirring at room temperature for 0.5 h, the temperature was raised to 80℃ for 2 h, and then the temperature was raised to 140℃ for 1 h. After the reaction was completed and cooled, a fullerene crosslinking agent was obtained.

[0045] The hydrogen content of the double-ended hydrogen-containing silicone oil is 0.05 wt%.

[0046] The preparation method of the resin crosslinking agent includes the following steps: (C1) Under argon protection, 2.0g of hydrogen-containing MQ resin, 30g of double-ended vinyl silicone oil and 0.1g of PT-1000ppm platinum catalyst are added to the reaction flask and mixed. The mixture is stirred at room temperature for 0.5h to achieve uniform mixing; (C2) The mixture is heated to 80℃ and reacted for 2h, then heated to 140℃ and reacted for another 1h. After the reaction is completed and cooled, the resin crosslinking agent is obtained.

[0047] The hydrogen content of the hydrogen-containing MQ resin is 0.18 wt%, and the vinyl content of the double-ended vinyl silicone oil is 0.05 wt%.

[0048] The redox-responsive crosslinked silicone paste is used to prepare an organosilicon defoamer. The preparation method of the organosilicon defoamer includes the following steps: (R1) 15g of redox-responsive crosslinked silicone paste, 1g of Span emulsifier, and 1g of Tween emulsifier are added to a reaction vessel. Under the condition of 25°C, 20g of ultrapure water containing 0.2g of oxidant ferric sulfate is added. The mixture is sheared and emulsified at 5000rpm for 30min using a high-speed homogenizer to obtain an emulsion; (R2) The speed is reduced to 500rpm, and 0.1g of cellulose thickener and 0.04g of reducing agent oxalic acid are added to the emulsion to adjust the viscosity of the emulsion to 1000cSt to obtain the organosilicon defoamer.

[0049] The Span-type emulsifier is Span-40, the Tween-type emulsifier is Tween-40, and the cellulose-type thickener is hydroxypropyl methylcellulose.

[0050] Example 3: A method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups, comprising the following steps: (S1) Under argon protection, the temperature is raised to 120°C, and 6 g of component A, 30 g of component B, and 7 g of component C are added to 30 g of carrier oil under stirring. The mixture is stirred for 1.5 h, and then 1.5 g of caster catalyst is added. A hydrosilylation reaction is carried out at 120°C, with high-speed shear maintained during the reaction. The reaction is carried out for 5 h to form primary crosslinked silicone paste particles with an interpenetrating network structure; (S2) 10 g of component D and 0.10 g of caster catalyst are added to the above primary crosslinked silicone paste particles, and the reaction is continued for 2.0 h. Then the temperature is raised to 160°C for aging reaction for 3 h. After the reaction is completed, 60 g of component D and 0.10 g of caster catalyst are added. g carrier oil, cooled and discharged, yields a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups; wherein, component A is a vinyl-modified filler, component B is a fullerene crosslinking agent, component C is a resin crosslinking agent, and component D is a functional end-capping agent.

[0051] The carrier oil is dimethyl silicone oil; the cassette catalyst is selected from a platinum catalyst with a PT-1000ppm concentration; and component D is 1,1'-bis(ferrocene)-1-butene.

[0052] The preparation method of the vinyl-modified filler includes the following steps: (A1) Add 100 mL of deionized water to a 500 mL flask equipped with a magnetic stirrer, then add acetic acid to adjust the pH of the solution to 3-5, then add 3.0 g of unsaturated double-bonded silane coupling agent, and stir and hydrolyze at room temperature for 50 min; (A2) Then add 10.0 g of hydrophilic fumed silica (Degussa A200), stir and react for 6 h under 80℃ oil bath conditions, and then... The filter cake was filtered through a microporous membrane and washed twice with water and twice with anhydrous ethanol. (A3) The filter cake was dried in a vacuum drying oven at 60°C for 12 hours and then ground to obtain vinyl-modified filler.

[0053] The unsaturated double-bonded silane coupling agent is methylvinyldimethoxysilane.

[0054] The preparation method of the fullerene crosslinking agent includes the following steps: (B1) In a dry 100 mL three-necked flask, 0.5 g of acrylic acid, 0.8 g of fullerol and 0.3 g of catalyst 4-dimethylaminopyridine are added to 30 mL of anhydrous dichloromethane to dissolve the solids. The mixture is cooled to 0°C under ice bath conditions, and 15 g of the catalyst is added dropwise over 10 min with stirring. mL of anhydrous dichloromethane solution containing 1.0 g N,N'-dicyclohexylcarbodiimide was reacted at 0°C for 30 min. The ice bath was then removed, and the reaction was stirred at room temperature for 72 h. The reaction progress was monitored by thin-layer chromatography (TLC). After the reaction was completed, the reaction solution was concentrated under reduced pressure and purified by column chromatography to obtain a fullerene derivative containing double bonds. (B2) Under argon protection, 60 g of hydrogen-terminated silicone oil, 0.9 g of fullerene derivative containing double bonds, and 0.500 g of PT-1000 ppm platinum catalyst were added to the reaction flask. After stirring at room temperature for 2.0 h, the temperature was raised to 120°C and reacted for 6 h. Then, the temperature was raised to 160°C and reacted for 3 h. After the reaction was completed and cooled, a fullerene crosslinking agent was obtained.

[0055] The hydrogen content of the double-ended hydrogen-containing silicone oil is 0.5 wt%.

[0056] The preparation method of the resin crosslinking agent includes the following steps: (C1) Under argon protection, 10.0g of hydrogen-containing MQ resin, 200g of double-ended vinyl silicone oil and 1.5g of PT-1000ppm platinum catalyst are added to the reaction flask and mixed. The mixture is stirred at room temperature for 3.0h to achieve uniform mixing; (C2) The mixture is heated to 120℃ and reacted for 6h, then heated to 160℃ and reacted for another 3h. After the reaction is completed and cooled, the resin crosslinking agent is obtained.

[0057] The hydrogen-containing MQ resin has a hydrogen content of 1.5 wt%, and the vinyl content of the double-ended vinyl silicone oil is 0.4 wt%.

[0058] The redox-responsive crosslinked silicone paste is used to prepare an organosilicon defoamer. The preparation method of the organosilicon defoamer includes the following steps: (R1) 35g of redox-responsive crosslinked silicone paste, 3g of Span emulsifier, and 3g of Tween emulsifier are added to a reaction vessel. Under the condition of 80°C, 50g of ultrapure water containing 1.2g of ferric sulfate oxidant is added. The mixture is sheared and emulsified at 12000rpm using a high-speed homogenizer for 120min to obtain an emulsion; (R2) The speed is reduced to 800rpm, 1.2g of cellulose thickener and 0.3g of reducing agent oxalic acid are added to the emulsion, and the viscosity of the emulsion is adjusted to 5000cSt to obtain the organosilicon defoamer.

[0059] The Span-type emulsifier is Span-20, the Tween-type emulsifier is Tween-20, and the cellulose-type thickener is hydroxyethyl cellulose.

[0060] Comparative Example 1: An organosilicon defoamer selected from Dow Chemical's DOWSIL FS Antifoam 544 Compound (Defoamer 544).

[0061] Comparative Example 2: An organosilicon defoamer selected from BYK-024.

[0062] Testing and Characterization: I. To verify the successful preparation of each modified component and the formation of the final crosslinked network, FT-IR analysis was performed on key intermediates and products. Based on Example 1, the infrared spectra of hydrophilic fumed silica, KH570, and component A were tested; the infrared spectra of fullerene derivatives containing double bonds, hydrogen-terminated silicone oil, and component B were tested; and the infrared spectra of vinyl-terminated silicone oil, hydrogen-containing MQ resin, and component C were tested. The testing conditions were as follows: Fourier Transform Infrared Spectroscopy (FT-IR): A Nicolet 6700 Fourier Transform Infrared Spectrometer (Thermo Scientific, USA) was used. Testing conditions: ATR total reflection mode (germanium crystal), scanning range 600-4000 cm⁻¹ -1 .

[0063] The test results are shown in Figure 6-7.

[0064] (1) The structure of component A (SiO2-C=C) is confirmed as shown in Figure 6. Comparing the spectra of fumed silica (SiO2), silane coupling agent (KH570), and modified product (SiO2-C=C), it can be seen that in the SiO2-C=C spectrum, 1083 cm⁻¹ -1 The Si-O-Si antisymmetric stretching vibration peak at the silica surface becomes narrower and sharper, indicating that a large amount of free hydroxyl groups on the silica surface are consumed, the surface hydrogen bonding is weakened, and the hydrophobicity is significantly improved. Meanwhile, the characteristic absorption peak of KH570 at 2944 cm⁻¹ is clearly visible in the spectrum. -1 (CH stretching vibration), 1718 cm -1 (C=O carbonyl vibration) and 1637 cm -1 (C=C double bond vibration). The appearance of the above characteristic peaks and the change in the hydroxyl peak confirm that KH570 has been successfully grafted onto the silica surface through chemical bonding, thus preparing a modified filler with active double bonds (component A).

[0065] (2) Component B (C 60 The structure of (-SO-SiH) is confirmed as shown in Figure 7. In the spectrum of component B, the characteristic vibrational peak of the fullerene carbon skeleton (1430 cm⁻¹) was observed. -1 and 1180 cm -1It also retains the characteristic Si-H absorption peak (2160 cm⁻¹) of hydrogen-containing silicone oil (PHMS). -1 ) and Si-CH3 characteristic peak (1260 cm⁻¹) -1 The key change lies in the raw material, fullerol acrylate (C...). 60 -C=C) at 1637 cm -1 The characteristic absorption peak of the double bond at the point completely disappeared. This result strongly proves that the double bond in the fullerol acrylate underwent a complete hydrosilylation reaction with the hydrogen-containing silicone oil, successfully constructing a fullerene crosslinking center (component B) with a surface rich in active silane-hydrogen bonds.

[0066] (3) The structure of component C (MQ-SO-C=C) is confirmed as shown in Figure 8. The spectrum of component C shows the typical Si-O-Si framework vibration of MQ resin (1064 cm⁻¹). -1 ) and Si-CH3 deformation vibration (840 cm) -1 The most significant change compared to the raw material hydrogen-containing MQ resin is at 2165 cm⁻¹. -1 The complete disappearance of the Si-H characteristic absorption peak at the MQ resin surface indicates that the active hydrogen on the MQ resin surface has fully participated in the reaction. Combined with the introduction of vinyl silicone oil segments, this confirms that vinyl silicone oil has been successfully grafted onto the MQ resin surface, yielding a resin reinforcing component (component C) with reactive double bonds.

[0067] II. Thermal Stability Analysis (TG) of Materials Thermal stability is an important indicator for evaluating whether an antifoaming agent can withstand harsh working conditions such as high-temperature pulping and dyeing. Based on Example 1, the thermogravimetric analysis (TG) curves of fullerene-ferrocene-based crosslinked silicone paste were tested. The test method is as follows: A TGA 8000 thermogravimetric analyzer (PerkinElmer) was used. Test conditions: nitrogen atmosphere (flow rate 20 mL / min), sample volume approximately 8 mg, alumina crucible, heating rate 10 ℃ / min, temperature range room temperature to 600 ℃.

[0068] The test results are shown in Figure 9.

[0069] Figure 9 shows the thermogravimetric (TG) curves of the fullerene / ferrocene-based crosslinked silicone paste prepared according to this invention. The results show that this crosslinked silicone paste exhibits excellent heat resistance, with an initial decomposition temperature (T5%) as high as 339.6℃. Even at 600℃, the system retains a high char residue of 58.23%. This excellent thermal stability is mainly attributed to two factors: firstly, the dense inorganic-organic hybrid network formed by the rigid fullerene spheres and MQ silicone resin effectively blocks heat transfer; secondly, the high-bond-energy Si-O-Si framework formed by silica and siloxane segments possesses inherent heat resistance. This indicates that the silicone paste can fully meet the defoaming requirements of high-temperature foaming systems.

[0070] III. Rheological Behavior Analysis of Crosslinked Silicone Paste Rheological properties directly affect the dispersion efficiency of silicone paste during emulsification and its spreading ability on the foam wall. Based on Example 1, the rheological viscosity of fullerene / ferrocene-based crosslinked silicone paste was tested at different shear rates. Viscosity testing method: NDJ-9S digital viscometer (Shenzhen Dingxinyi Test Equipment Co., Ltd.), measurement range 0-6×10⁻⁶. 6 mPa·s, measured at room temperature.

[0071] The test results are shown in Table 1 below: Table 1 Rheological viscosity data of fullerene / ferrocene-based crosslinked silicone paste at different shear rates

[0072] Table 1 lists the viscosity data of the crosslinked silicone paste as a function of shear rate at room temperature. The test results show that the silicone paste exhibits obvious pseudoplastic fluid (shear-thinning) characteristics. At low shear rates, the silicone paste maintains a high viscosity, which is beneficial for maintaining the storage stability of the emulsion system and preventing the sedimentation of active ingredients; while at high shear rates, the viscosity decreases rapidly, which not only benefits subsequent emulsification and dispersion processes but also ensures that the defoamer can quickly spread at the gas-liquid interface during use, achieving rapid foam defoaming. This rheological property is attributed to the physical-chemical dual crosslinking network constructed by fullerene and modified silica in the silicone oil matrix.

[0073] IV. Defoaming Performance Test and Redox Response Mechanism Verification: To verify the core advantage of this invention—namely, resolving the contradiction between "difficult emulsification" and "poor foam suppression" through the redox switching of ferrocene groups—the defoaming performance test method (hand-shaking method) for the organosilicon defoamers of Example 1 and Comparative Examples 1-2 was performed on the appearance and defoaming performance of the organosilicon defoamers in Example 1 and Comparative Examples 1-2. Appearance observation method: Take 10 ml of the organosilicon defoamer from Example 1 and Comparative Examples 1-2 respectively and observe the phenomenon of the liquid.

[0074] Defoaming performance test was conducted according to the national standard GB / T 26527-2024 "Determination of Defoaming Performance of Organosilicon Defoamers" (hand-shaking method). Test method: Prepare the foaming solution by dissolving 5.0 g of fatty alcohol polyoxyethylene ether (AEO-9) and 5.0 g of sodium dodecylbenzenesulfonate in 990 mL of deionized water and stirring until homogeneous and transparent. Take 50 mL of the foaming solution into a custom-made square plastic bottle, add 0.05 g of each test defoamer to a solid content of 10 wt%, and after capping the bottle, shake it up and down 10, 100, and 1000 times at a frequency of 2 times / second and an amplitude of 30-35 cm. Record the time required for the foam to subside to the liquid surface (unit: seconds).

[0075] The test results are shown in Table 2 below:

[0076] As shown in Table 2 above: (1) Emulsification and dispersibility and defoaming speed (defoaming performance): During the emulsification stage, due to the introduction of oxidant, the ferrocene groups on the surface of the silicone paste are converted into hydrophilic ferrocene ions, which significantly reduces the oil-water interfacial tension. Experimental observation shows that the silicone paste of the present invention is very easy to disperse, and the resulting emulsion has a uniform particle size. After adding reducing agent, the ferrocene groups are reduced to a hydrophobic state, restoring the high hydrophobicity of the silicone paste. Data shows that the defoaming time of the defoamer of the present invention after shaking 10 times is significantly shorter than that of the commercially available Dow Chemical defoamer 544 in Comparative Example 1, showing a very fast defoaming speed. This indicates that the "smart switch" strategy successfully achieves easy emulsification during processing and high activity during use.

[0077] (2) Long-lasting defoaming performance: In the high-shear simulation test with 100 shakes, the defoaming advantage of the sample of the present invention is more significant. Compared with comparative examples 1-2, the defoamer of the present invention can still maintain a very short defoaming time after long-term shaking, without obvious performance degradation. This is mainly due to the reinforcing effect introduced by fullerene: as a rigid nanonode, fullerene significantly improves the mechanical strength of silicone paste particles, making them less prone to breakage and detachment under repeated shearing and foam rupture impacts, thereby maintaining the complete "bridging" structure and achieving excellent long-lasting defoaming performance.

[0078] In summary, the crosslinked silicone paste prepared by this invention possesses excellent thermal stability, suitable rheological properties, and outstanding defoaming / foam-suppressing performance, successfully solving the technical bottlenecks of traditional organosilicon defoamers in terms of emulsification stability and shear resistance.

[0079] This invention successfully prepared a novel cross-linked silicone paste integrating nano-reinforcement and intelligent surface response through molecular structure design and a stepwise reaction strategy. This material not only overcomes the shortcomings of traditional organosilicon defoamers, such as difficult emulsification and short foam suppression time, but also improves the material's shear resistance by introducing fullerenes. This technical solution is scientifically sound and the process is controllable, showing broad application prospects and significant commercial value in the field of high-end industrial defoamers.

[0080] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups, characterized in that, The process includes the following steps: (S1) Under argon protection, the temperature is raised to 60-120℃, and components A, B, and C are added to the carrier oil under stirring. The mixture is stirred for 0.5-1.5 hours, and then a cascade catalyst is added. A hydrosilylation reaction is carried out at 80-120℃, with high-speed shearing maintained during the reaction. The reaction lasts for 3-5 hours to form primary cross-linked silicone paste particles with an interpenetrating network structure. (S2) Component D and the cascade catalyst are added to the above primary cross-linked silicone paste particles, and the reaction continues for 1.0-2.0 hours. Then, the temperature is raised to 140-160℃ for aging reaction for 1-3 hours. After the reaction is completed, the carrier oil is added, the temperature is lowered, and the material is discharged to obtain a redox-responsive cross-linked silicone paste containing fullerene and ferrocene groups. Component A is a vinyl-modified filler, component B is a fullerene cross-linking agent, component C is a resin cross-linking agent, and component D is a functional end-capping agent.

2. The method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups according to claim 1, characterized in that: The carrier oil is dimethyl silicone oil or alkyl-modified silicone oil; the cassette catalyst is selected from platinum catalysts with PT-1000ppm; component D is at least one of allyl ferrocene carboxylate, vinylferrocene, and 1,1'-bis(ferroceneyl)-1-butene; the amounts of each raw material by weight are as follows: 10-30 parts of carrier oil, 3-6 parts of component A, 5-30 parts of component B, 2-7 parts of component C, and 0.1-1.5 parts of cassette catalyst in step (S1); 2-10 parts of component D, 0.02-0.10 parts of cassette catalyst, and 20-60 parts of carrier oil in step (S2).

3. The method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups according to claim 1, characterized in that, The preparation method of the vinyl-modified filler includes the following steps: (A1) By weight, add acetic acid to 60-100 parts of deionized water to adjust the pH of the solution to 3-5, then add 1.0-3.0 parts of unsaturated double-bonded silane coupling agent, and stir and hydrolyze at room temperature for 30-50 min; (A2) Then add 5.0-10.0 parts of hydrophilic fumed silica, stir and react in an oil bath at 60-80℃ for 1-6 h, and then... The filter cake was filtered through a microporous membrane and washed twice with water and twice with anhydrous ethanol. (A3) The filter cake was dried in a vacuum drying oven at 60°C for 6-12 hours and then ground to obtain vinyl-modified filler.

4. The method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups according to claim 3, characterized in that: The unsaturated double-bonded silane coupling agent is at least one of γ-methacryloxypropyltrimethoxysilane, vinyltris(2-methoxyethoxy)silane, vinyltrimethoxysilane, and methylvinyldimethoxysilane; the average particle size of the hydrophilic fumed silica is 10-30 nm.

5. The method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups according to claim 1, characterized in that, The preparation method of the fullerene crosslinking agent includes the following steps: (B1) By weight, 0.2-0.5 parts of acrylic acid, 0.5-0.8 parts of fullerol, and 0.1-0.3 parts of catalyst 4-dimethylaminopyridine are added to 13-40 parts of anhydrous dichloromethane to dissolve the solid. The mixture is cooled to 0°C under ice bath conditions. With stirring, 13-21 parts of anhydrous dichloromethane solution containing 0.2-1.0 parts of N,N'-dicyclohexylcarbodiimide are added dropwise over 2-10 minutes. The reaction is continued at 0°C for 10-30 minutes. Then, the ice bath is removed, and the mixture is stirred at room temperature for 10-72 hours. The reaction process was monitored by thin-layer chromatography (TLC). After the reaction was completed, the reaction solution was concentrated under reduced pressure and purified by column chromatography to obtain a fullerene derivative containing double bonds. (B2) Under argon protection, 5-60 parts of hydrogen-containing silicone oil at both ends, 0.2-0.9 parts of fullerene derivative containing double bonds and 0.010-0.500 parts of PT-1000ppm platinum catalyst were added to the reaction flask. After stirring at room temperature for 0.5-2.0 h, the temperature was raised to 80-120℃ and reacted for 2-6 h. Then the temperature was raised to 140-160℃ and reacted for 1-3 h. After the reaction was completed and cooled, the fullerene crosslinking agent was obtained.

6. The method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups according to claim 5, characterized in that: The hydrogen content of the double-ended hydrogen-containing silicone oil is 0.05-0.5 wt%.

7. The method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups according to claim 1, characterized in that, The preparation method of the resin crosslinking agent includes the following steps: (C1) By weight, under argon protection, 2.0-10.0 parts of hydrogen-containing MQ resin, 30-200 parts of double-ended vinyl silicone oil and 0.1-1.5 parts of PT-1000ppm platinum catalyst are mixed and stirred at room temperature for 0.5-3.0h to mix evenly; (C2) Heating to 80-120℃ for 2-6h, then heating to 140-160℃ for 1-3h, and cooling after the reaction is completed to obtain the resin crosslinking agent.

8. The method for preparing a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups according to claim 7, characterized in that: The hydrogen content of the hydrogen-containing MQ resin is 0.18-1.5wt%, and the vinyl content of the double-ended vinyl silicone oil is 0.05-0.4wt%.

9. A redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups, characterized in that: It is prepared by the redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups as described in any one of claims 1-8.

10. The application of a redox-responsive crosslinked silicone paste containing fullerene and ferrocene groups as described in claim 9, characterized in that: The redox-responsive crosslinked silicone paste is used to prepare an organosilicon defoamer. The preparation method of the organosilicon defoamer includes the following steps: (R1) By weight, 15-35 parts of redox-responsive crosslinked silicone paste, 1-3 parts of Span emulsifier, and 1-3 parts of Tween emulsifier are added to a reaction vessel. Under the temperature of 25-80℃, 20-50 parts of water containing 0.2-1.2 parts of oxidant are added. The mixture is sheared and emulsified using a high-speed homogenizer at a speed of 5000-12000 rpm for 30-120 min to obtain an emulsion; (R2) The speed is reduced to 500-800 rpm, and 0.1-1.2 parts of cellulose thickener and 0.04-0.3 parts of reducing agent are added to the emulsion to adjust the viscosity of the emulsion to 1000-5000 cSt to obtain the organosilicon defoamer.

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