Efficient space station water treatment solid defoaming agent and preparation method thereof

Abstract

The application discloses a kind of high-efficiency space station water treatment solid defoaming agent and preparation method thereof, and relates to the technical field of defoaming agent.The high-efficiency space station water treatment solid defoaming agent includes the following raw materials by weight fraction: dimethyl silicone oil 25-35 parts, water-soluble silicone oil 5-10 parts, surfactant 4-5 parts, dispersing agent 0.5-1.5 parts, anti-caking agent 1.5-2.5 parts, disintegrating agent 1-2 parts, carrier 25-35 parts.By 2-(1-bromovinyl) naphthalene and 3,6,9,12,15,18-hexaoxanonadecan-1-thiol reaction to generate intermediate 1, intermediate 1 and 3-aminopropyl trimethoxysilane reaction to generate intermediate 2, intermediate 2 and glycerol triglycidyl ether reaction to generate surfactant.The high-efficiency space station water treatment solid defoaming agent prepared by the application has excellent water dispersibility, defoaming performance and bubble inhibition performance.

Description

Technical Field

[0001] This invention relates to the field of defoamer technology, specifically to a high-efficiency solid defoamer for space station water treatment and its preparation method. Background Technology

[0002] Water resources in the space station environment need to be repeatedly purified and reused through a closed-loop system. The water treatment process typically involves multiple operations such as biochemical degradation, membrane separation, gas-liquid separation, and catalytic oxidation. These systems commonly contain surface-active organic matter, microbial metabolites, and trace amounts of detergent residue, which easily generate large amounts of foam during aeration, biochemical reactions, and circulation. Unlike Earth's gravity conditions, bubbles are difficult to rise and burst in microgravity, causing foam to remain in reactors and pipelines for extended periods. This can lead to decreased gas-liquid separation efficiency, membrane module blockage, and system instability, becoming a significant factor restricting the safe and reliable operation of the space station's water treatment system. Currently, commonly used defoamers in the water treatment field are mainly liquid dimethyl silicone oil or mineral oil-based. However, liquid defoamers are prone to stratification, leakage, or activity degradation during long-term storage, and their addition is difficult to control in a microgravity environment. Existing solid or powder defoamers mostly employ polymeric dispersants such as polyacrylates and lignin sulfonates to improve particle dispersibility. However, these dispersants have strong hydration capabilities and easily form highly elastic hydration layers at the interface, which is detrimental to bubble film rupture. Furthermore, their dispersion stability in high-electrolyte circulating water systems is easily affected by ionic strength, making it difficult to meet the requirements for long-term stable operation of the space station. In addition, traditional defoaming aids mostly focus on a single function, such as improving spreading or dispersion stability, lacking defoamers that address the synergistic effect between "efficient transport of silicone oil to the bubble film interface" and "long-term stable dispersion of particles in water," making it difficult to simultaneously achieve rapid defoaming and long-lasting foam suppression performance. Therefore, developing a novel, highly efficient defoaming system suitable for the space station water treatment environment, existing in solid form, stable in storage, and capable of rapid disintegration and dispersion upon water introduction, while incorporating special surfactants with interfacial destabilization capabilities and small-molecule dispersants with low foam-stabilizing tendencies, has become a pressing technical problem to be solved in this field.

[0003] Chinese invention patent CN104436765A discloses a method for preparing a solid defoamer. The method involves the following steps: First, the following components are mixed in the following proportions by weight: white mineral oil: white carbon black: self-emulsifying silicone oil: dimethyl silicone oil: fatty acid amide: paraffin wax: polyvinyl alcohol: emulsifier = (20-40) parts: (5-10) parts: (5-10) parts: (20-4) parts: (2-4) parts: (20-40) parts: (2-10) parts: (5-10) parts. Then, the above-mentioned components are added to a reaction vessel equipped with a stainless steel stirring paddle, a motor, and a heating system. The components are mixed evenly at room temperature, then heated to 130°C and held at that temperature for 3-5 hours. Finally, the mixture is continuously stirred and cooled to room temperature before being discharged. This invention has advantages such as a relatively simple preparation method, low production cost, environmentally friendly and pollution-free solid defoamer, and good performance indicators. However, its dispersion performance still needs to be improved. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a high-efficiency solid defoamer for space station water treatment and its preparation method.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A high-efficiency solid defoamer for space station water treatment comprises the following raw materials in parts by weight: 25-35 parts dimethyl silicone oil, 5-10 parts water-soluble silicone oil, 4-5 parts surfactant, 0.5-1.5 parts dispersant, 1.5-2.5 parts anti-caking agent, 1-2 parts disintegrant, and 25-35 parts carrier; The surfactant is prepared by the following method: S1: 2-(1-bromovinyl)naphthalene reacts with 3,6,9,12,15,18-hexaoxane-1-thiol to form intermediate 1; the reaction equation is shown below:

[0006] S2: Intermediate 1 reacts with 3-aminopropyltrimethoxysilane to generate intermediate 2; the reaction equation is shown below.

[0007] S3: Intermediate 2 reacts with glycerol triglycidyl ether to form a surfactant. The reaction equation is shown below:

[0008] In step S1, the molar ratio of 2-(1-bromovinyl)naphthalene to 3,6,9,12,15,18-hexaoxane-1-thiol is 1:(1.02-1.04).

[0009] In step S2, the molar ratio of intermediate 1 to 3-aminopropyltrimethoxysilane is 1:(1.02-1.05).

[0010] In step S3, the molar ratio of intermediate 2 to glycerol triglycidyl ether is (3.01-3.03):1.

[0011] The dispersant is prepared by the following method: N1: 4,4'-Diaminodibenzo-18-crown ether-6 reacts with β-(acryloyloxy)propionic acid to generate intermediate A; the reaction equation is shown below:

[0012] N2: Intermediate A reacts with lauryl hydroxysulfonate to form a dispersant. The reaction equation is shown below:

[0013] In step N1, the molar ratio of 4,4'-diaminodibenzo-18-crown ether-6 to β-(acryloyloxy)propionic acid is 1:2.01.

[0014] In step N2, the molar ratio of intermediate A to lauryl hydroxysulfonate betaine is 1:2.03.

[0015] The anti-caking agent is talc; the disintegrant is sodium chloride.

[0016] The carrier is diatomaceous earth.

[0017] A method for preparing a high-efficiency solid defoamer for space station water treatment includes the following steps: (1) Weigh out the following by weight: 25-35 parts of dimethyl silicone oil, 5-10 parts of water-soluble silicone oil, 4-5 parts of surfactant, 0.5-1.5 parts of dispersant, 1.5-2.5 parts of anti-caking agent, 1-2 parts of disintegrant, and 25-35 parts of carrier; (2) Mix dimethyl silicone oil and water-soluble silicone oil, heat and stir to mix evenly, cool down, add surfactant, dispersant, anti-caking agent and disintegrant and stir to mix evenly, add carrier and stir to obtain mixture; after drying, crushing and sieving the mixture, obtain high-efficiency solid defoamer for space station water treatment.

[0018] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include: The high-efficiency solid defoamer for space station water treatment prepared by this invention has excellent water dispersibility, defoaming performance and foam suppression performance. Attached Figure Description

[0019] Figure 1 The image shows the proton NMR spectrum of the surfactant prepared in Example 1.

[0020] Figure 2 The image shows a high-resolution mass spectrum of the surfactant prepared in Example 1.

[0021] Figure 3 The image shows the proton NMR spectrum of the dispersant prepared in Example 4.

[0022] Figure 4 The image shows a high-resolution mass spectrum of the dispersant prepared in Example 4. Detailed Implementation

[0023] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0024] Example 1 Preparation of Surfactants S1: Under nitrogen protection, 250 ml of tetrahydrofuran, 0.1 mol of 2-(1-bromovinyl)naphthalene, 0.102 mol of 3,6,9,12,15,18-hexaoxane-1-thiol, and 0.5 g of 2,2-dimethoxy-2-phenylacetophenone were stirred and mixed thoroughly at room temperature under an intensity of 100 mW / cm. 2 Irradiated with 365 nm ultraviolet light for 30 min, distilled under reduced pressure at 40 °C for 2 h, added 200 ml of cold diethyl ether and stirred to precipitate, filtered, the filter cake was washed with 80 ml of cold diethyl ether and dried under vacuum at 40 °C for 12 h to obtain intermediate 1; its 1H NMR data are as follows: 1 H NMR (400 MHz, DMSO- d 6 ) δ 8.00-7.92 (m, 2H), 7.88 (d, J = 6.6 Hz, 1H), 7.73 (d, J = 6.7 Hz, 1H), 7.51 (s, 2H), 7.40 (d, J = 7.6 Hz, 1H), 4.83-4.74 (m, 1H), 3.68-3.50 (m, 22H), 3.30 (s, 3H), 3.28-3.21 (m, 2H), 2.68 (d, J= 7.5 Hz, 2H); HRMS (m / z):545.1497[M+H] + ; S2: Under nitrogen protection, 500 ml of anhydrous acetonitrile, 0.1 mol of intermediate 1, 0.102 mol of 3-aminopropyltrimethoxysilane, and 15 g of 4A molecular sieve were stirred and mixed. 0.11 mol of potassium carbonate was added, and the mixture was heated to 55°C and reacted for 9 h. After cooling to room temperature, the mixture was filtered and distilled under reduced pressure at 50°C for 2 h. A mixed solution of 200 ml of anhydrous ethyl acetate and anhydrous n-hexane (V) was used. 无水乙酸乙酯 :V无水正己烷 Recrystallize (6:4 ratio), filter, and dry under vacuum at 50°C for 12 h to obtain intermediate 2; its 1H NMR data are as follows: 1 H NMR (400MHz, DMSO- d 6 ) δ 7.95 (d, J = 6.7 Hz, 1H), 7.89 (dd, J = 9.9, 6.5 Hz, 2H), 7.81 (d, J = 6.7 Hz, 1H), 7.51 (s, 2H), 7.33 (d, J = 6.6 Hz, 1H), 4.09 (d, J= 7.5 Hz, 1H), 3.82 (d, J = 4.5 Hz, 1H), 3.70-3.53 (m, 22H), 3.52 (s, 9H), 3.30 (s, 3H), 3.07-2.95 (m, 2H), 2.72-2.59 (m, 4H), 1.76-1.63 (m, 2H), 1.13-1.08 (m, 2H); HRMS (m / z):644.3215[M+H] + ; S3: Under nitrogen protection, 650 ml of anhydrous ethanol and 0.301 mol of intermediate 2 were stirred and mixed. 0.1 mol of glycerol triglycidyl ether was slowly added dropwise over 30 minutes. The mixture was then heated to 60°C and reacted for 7 hours. After cooling to room temperature, it was distilled under reduced pressure at 50°C for 1 hour. The distillate was then distilled using a mixed solution of 650 ml of anhydrous ethyl acetate and anhydrous n-hexane (V... 无水乙酸乙酯 :V 无水正己烷 The surfactant was obtained by recrystallization of a mixture of 8:2 and vacuum drying at 50°C for 8 hours; its proton NMR spectrum is shown below. Figure 1 As shown, the proton NMR data are as follows: 1 H NMR (400 MHz, Chloroform- d) δ 7.88 (d, J = 6.7 Hz, 9H), 7.65 (d, J = 6.6 Hz, 3H), 7.51 (d,J = 6.5 Hz, 6H), 7.36 (d, J = 6.5 Hz, 3H), 4.03 (s, 1H), 3.97-3.95 (m, 3H), 3.93 (d, J = 2.1 Hz, 3H), 3.87 (dd, J = 13.0, 4.9 Hz, 3H), 3.73-3.58 (m, 60H), 3.57 (s, 27H), 3.56-3.38 (m, 16H), 3.32 (s, 9H), 2.99 (d, J = 3.1 Hz, 6H), 2.80–2.44 (m, 18H), 1.70 (d, J = 2.7 Hz, 6H), 1.06–0.92 (m, 6H); its high-resolution mass spectrum is shown below. Figure 2 As shown, the mass spectrometry data are as follows: HRMS (m / z): 2192.0928 [M+H] + .

[0025] Example 2 Preparation of Surfactants S1: Under nitrogen protection, 250 ml of tetrahydrofuran, 0.1 mol of 2-(1-bromovinyl)naphthalene, 0.103 mol of 3,6,9,12,15,18-hexaoxane-1-thiol, and 0.5 g of 2,2-dimethoxy-2-phenylacetophenone were stirred and mixed thoroughly at room temperature under an intensity of 100 mW / cm². 2 Irradiate under 365nm ultraviolet light for 30 min, distill under reduced pressure at 40℃ for 2 h, add 200ml of cold diethyl ether and stir to precipitate, filter, wash the filter cake with 80ml of cold diethyl ether, and dry under vacuum at 40℃ for 12 h to obtain intermediate 1. S2: Under nitrogen protection, 500 ml of anhydrous acetonitrile, 0.1 mol of intermediate 1, 0.103 mol of 3-aminopropyltrimethoxysilane, and 15 g of 4A molecular sieve were stirred and mixed. 0.11 mol of potassium carbonate was added, and the mixture was heated to 60 °C and reacted for 8 h. After cooling to room temperature, the mixture was filtered and distilled under reduced pressure at 50 °C for 2 h. A mixed solution of 200 ml of anhydrous ethyl acetate and anhydrous n-hexane (V) was used. 无水乙酸乙酯 :V 无水正己烷 =6:4) recrystallized, filtered, and vacuum dried at 50℃ for 12h to obtain intermediate 2; S3: Under nitrogen protection, 650 ml of anhydrous ethanol and 0.302 mol of intermediate 2 were stirred and mixed. 0.1 mol of glycerol triglycidyl ether was slowly added dropwise over 30 minutes. The mixture was then heated to 65°C and reacted for 6.5 hours. After cooling to room temperature, it was distilled under reduced pressure at 50°C for 1 hour. The distillate was obtained using a mixture of 650 ml of anhydrous ethyl acetate and anhydrous n-hexane (V... 无水乙酸乙酯 :V 无水正己烷 The surfactant was obtained by recrystallizing (8:2 ratio) and drying under vacuum at 50°C for 8 hours.

[0026] Example 3 Preparation of Surfactants S1: Under nitrogen protection, 250 ml of tetrahydrofuran, 0.1 mol of 2-(1-bromovinyl)naphthalene, 0.104 mol of 3,6,9,12,15,18-hexaoxane-1-thiol, and 0.5 g of 2,2-dimethoxy-2-phenylacetophenone were stirred and mixed thoroughly at room temperature under an intensity of 100 mW / cm². 2 Irradiate under 365nm ultraviolet light for 30 min, distill under reduced pressure at 40℃ for 2 h, add 200ml of cold diethyl ether and stir to precipitate, filter, wash the filter cake with 80ml of cold diethyl ether, and dry under vacuum at 40℃ for 12 h to obtain intermediate 1. S2: Under nitrogen protection, 500 ml of anhydrous acetonitrile, 0.1 mol of intermediate 1, 0.105 mol of 3-aminopropyltrimethoxysilane, and 15 g of 4A molecular sieve were stirred and mixed. 0.11 mol of potassium carbonate was added, and the mixture was heated to 65°C and reacted for 7 h. After cooling to room temperature, the mixture was filtered and distilled under reduced pressure at 50°C for 2 h. A mixed solution of 200 ml of anhydrous ethyl acetate and anhydrous n-hexane (V) was used. 无水乙酸乙酯 :V 无水正己烷 =6:4) recrystallized, filtered, and vacuum dried at 50℃ for 12h to obtain intermediate 2; S3: Under nitrogen protection, 650 ml of anhydrous ethanol and 0.303 mol of intermediate 2 were stirred and mixed. 0.1 mol of glycerol triglycidyl ether was slowly added dropwise over 30 minutes. The mixture was then heated to 70°C and reacted for 6 hours. After cooling to room temperature, it was distilled under reduced pressure at 50°C for 1 hour. The distillate was then distilled using a mixed solution of 650 ml of anhydrous ethyl acetate and anhydrous n-hexane (V... 无水乙酸乙酯 :V 无水正己烷 The surfactant was obtained by recrystallizing (8:2 ratio) and drying under vacuum at 50°C for 8 hours.

[0027] Example 4 Preparation of dispersant N1: Under nitrogen protection, 300 ml of acetonitrile, 0.1 mol of 4,4'-diaminodibenzo-18-crown ether-6, and 0.201 mol of β-(acryloyloxy)propionic acid were stirred and mixed. 0.2 mol of triethylamine was added, and the mixture was heated to 50 °C and reacted for 8 h. After cooling to room temperature, the mixture was filtered. The filtrate was rotary evaporated at 50 °C to constant weight. 250 ml of cold n-hexane was added and stirred to precipitate the precipitate. The precipitate was filtered, and the filter cake was washed successively with cold n-hexane (3 × 50 ml) and cold diethyl ether (2 × 50 ml). The precipitate was dried under vacuum at 50 °C for 10 h to obtain intermediate A. Its 1H NMR data are as follows: 1 HNMR (400 MHz, Chloroform- d ) δ 11.23 (s, 2H), 6.76-6.69 (m, 2H), 6.59-6.54 (m,4H), 6.53 (s, 2H), 4.29 (d, J = 2.9 Hz, 4H), 4.20 (d, J = 6.9 Hz, 8H), 3.74(d, J = 3.7 Hz, 8H), 3.46 (d, J = 3.5 Hz, 4H), 2.64 (d, J = 8.0 Hz, 8H); HRMS(m / z):679.2641[M+H] + ; Under nitrogen protection, 800 ml of acetonitrile and 0.1 mol of intermediate A were stirred and mixed. Then, 0.21 mol of dicyclohexylcarbodiimide and 0.04 mol of 4-dimethylaminopyridine were added, and the mixture was stirred for 15 min. Then, 0.203 mol of lauryl hydroxysulfonate betaine was added, and the mixture was reacted at 25 °C for 18 h. After filtration, the mixture was rotary evaporated at 50 °C to constant weight. The final weight was determined using 450 ml of a mixed solution of dichloromethane and methanol (V...). 二氯甲烷 :V 甲醇 The mixture was recrystallized (7:3 ratio), filtered, and dried under vacuum at 50°C for 12 hours to obtain the dispersant; its proton NMR spectrum is shown below. Figure 3 As shown, the proton NMR data are as follows: 1H NMR (400 MHz, Chloroform- d) δ 6.76-6.69 (m, 2H), 6.58-6.55 (m, 4H), 6.53 (s, 2H), 5.36-5.30 (m, 2H), 4.25 (d, J = 3.0 Hz, 4H), 4.20 (dd, J = 4.2,3.8 Hz, 8H), 3.77-3.72 (m, 8H), 3.71-3.55 (m, 4H), 3.49-3.41 (m, 8H), 3.20 (s, 12H), 3.19-3.17 (m, 4H), 2.84-2.59 (m, 8H), 1.83-1.65 (m, 4H), 1.43-1.25(m, 36H), 0.90 (t, J = 6.2 Hz, 6H); its high-resolution mass spectrum is shown below. Figure 4 As shown, the mass spectrometry data are as follows: HRMS (m / z): 1345.7316 [M+H] + .

[0028] Example 5: Preparation of a high-efficiency solid defoamer for space station water treatment (1) Weigh the following by weight: 25g dimethyl silicone oil, 5g water-soluble silicone oil, 4g surfactant (prepared in Example 1), 0.5g dispersant (prepared in Example 4), 1.5g anti-caking agent (talc), 1g disintegrant (sodium chloride), and 25g carrier (diatomaceous earth); (2) Mix dimethyl silicone oil and water-soluble silicone oil, heat to 120°C, stir at 300 rpm for 2 hours, cool to 50°C, add surfactant, dispersant, anti-caking agent and disintegrant, stir at 300 rpm for 1 hour, add carrier, stir at 200 rpm for 1 hour to obtain a mixture; dry the mixture in a vacuum drying oven at 80°C for 12 hours, place it in a pulverizer, pulverize at 600 rpm for 15 minutes, pass through a 100-mesh sieve to obtain a high-efficiency solid defoamer for space station water treatment.

[0029] Example 6: Preparation of a high-efficiency solid defoamer for space station water treatment (1) Weigh the following by weight: 30g of dimethyl silicone oil, 8g of water-soluble silicone oil, 4.5g of surfactant (prepared in Example 2), 1g of dispersant (prepared in Example 4), 2g of anti-caking agent (talc), 1.5g of disintegrant (sodium chloride), and 30g of carrier (diatomaceous earth); (2) Mix dimethyl silicone oil and water-soluble silicone oil, heat to 120°C, stir at 300 rpm for 2 hours, cool to 50°C, add surfactant, dispersant, anti-caking agent and disintegrant, stir at 300 rpm for 1 hour, add carrier, stir at 200 rpm for 1 hour to obtain a mixture; dry the mixture in a vacuum drying oven at 80°C for 12 hours, place it in a pulverizer, pulverize at 600 rpm for 15 minutes, pass through a 100-mesh sieve to obtain a high-efficiency solid defoamer for space station water treatment.

[0030] Example 7 Preparation of a high-efficiency solid defoamer for space station water treatment (1) Weigh the following by weight: 35g of dimethyl silicone oil, 10g of water-soluble silicone oil, 5g of surfactant (prepared in Example 3), 1.5g of dispersant (prepared in Example 4), 2.5g of anti-caking agent (talc), 2g of disintegrant (sodium chloride), and 35g of carrier (diatomaceous earth); (2) Mix dimethyl silicone oil and water-soluble silicone oil, heat to 120°C, stir at 300 rpm for 2 hours, cool to 50°C, add surfactant, dispersant, anti-caking agent and disintegrant, stir at 300 rpm for 1 hour, add carrier, stir at 200 rpm for 1 hour to obtain a mixture; dry the mixture in a vacuum drying oven at 80°C for 12 hours, place it in a pulverizer, pulverize at 600 rpm for 15 minutes, pass through a 100-mesh sieve to obtain a high-efficiency solid defoamer for space station water treatment.

[0031] Comparative Example 1 The raw material composition and preparation method of the high-efficiency solid defoamer for space station water treatment are basically the same as those in Example 6, except that the surfactant is replaced with an equal weight of surfactant prepared by the following method: The preparation method of the surfactant is basically the same as that in Example 2, except that 2-(1-bromovinyl)naphthalene in step S1 is replaced with an equimolar amount of 1-styrene bromide.

[0032] Comparative Example 2 The raw material composition and preparation method of the high-efficiency solid defoamer for space station water treatment are basically the same as those in Example 6, except that the surfactant is replaced with an equal weight of surfactant prepared by the following method: The preparation method of the surfactant is basically the same as that in Example 2, except that 3,6,9,12,15,18-hexaoxane-1-thiol in step S1 is replaced with an equimolar amount of 2,5,8,11,14,17,20,23,26,29-decaoxane-31-thiol.

[0033] Comparative Example 3 The raw material composition and preparation method of the high-efficiency solid defoamer for space station water treatment are basically the same as those in Example 6, except that the surfactant is replaced with an equal weight of surfactant prepared by the following method: The preparation method of the surfactant is basically the same as that in Example 2, except that 3,6,9,12,15,18-hexaoxane-1-thiol in step S1 is replaced with an equimolar amount of 2-methoxy[2-ethoxy(2-ethoxy)]-1-ethanethiol.

[0034] Comparative Example 4 The raw material composition and preparation method of the high-efficiency solid defoamer for space station water treatment are basically the same as those in Example 6, except that the surfactant is replaced with an equal weight of surfactant prepared by the following method: The preparation method of the surfactant is basically the same as that in Example 2, except that 3,6,9,12,15,18-hexaoxane-1-thiol in step S1 is replaced with an equimolar amount of 1-octadecanethiol.

[0035] Comparative Example 5 The raw material composition and preparation method of the high-efficiency solid defoamer for space station water treatment are basically the same as those in Example 6, except that the surfactant is replaced with an equal weight of surfactant prepared by the following method: The preparation method of the surfactant is basically the same as that in Example 2, except that the glycerol triglycidyl ether in step S3 is replaced with 0.15 mol of ethylene glycol diglycidyl ether.

[0036] Comparative Example 6 The raw material composition and preparation method of the high-efficiency solid defoamer for space station water treatment are basically the same as those in Example 6, except that the surfactant is replaced with an equal weight of surfactant prepared by the following method: The preparation method of the surfactant is basically the same as that in Example 2, except that the glycerol triglycidyl ether in step S3 is replaced with 0.075 mol of pentaerythritol glycidyl ether.

[0037] Comparative Example 7 The raw material composition and preparation method of the high-efficiency solid defoamer for space station water treatment are basically the same as those in Example 6, except that the dispersant is replaced with an equal weight of dispersant prepared by the following method: The preparation method of the dispersant is basically the same as that in Example 4, except that 4,4'-diaminodibenzo-18-crown ether-6 in step N1 is replaced with 0.2 mol of 4'-aminobenzo-18-crown ether-6; and the amount of lauryl hydroxysulfonate in step N2 is replaced with 0.101 mol.

[0038] Comparative Example 8 The raw material composition and preparation method of the high-efficiency solid defoamer for space station water treatment are basically the same as those in Example 6, except that the dispersant is replaced with an equal weight of dispersant prepared by the following method: The preparation method of the dispersant is basically the same as that in Example 4, except that 4,4'-diaminodibenzo-18-crown ether-6 in step N1 is replaced with an equimolar amount of 6,7,14,15-tetrahydro-dibenzo[b,h][1,4,7,10]tetraoxane-2,11-diamine (CAS No. 2699877-12-6).

[0039] Comparative Example 9 The raw material composition and preparation method of the high-efficiency solid defoamer for space station water treatment are basically the same as those in Example 6, except that the dispersant is replaced with an equal weight of dispersant prepared by the following method: The preparation method of the dispersant is basically the same as that in Example 4, except that lauryl hydroxysulfonate betaine in step N2 is replaced with an equimolar amount of dodecyl (2-hydroxyethyl) dimethylammonium bromide.

[0040] The dimethyl silicone oil used in the embodiments and comparative examples of this application is model QL-201, manufactured by Jiangsu Quanli Chemical Co., Ltd.; the water-soluble silicone oil is model Cosmethicone. ® SF-939 is produced by Guangdong Biaomei Silicon Fluorine New Materials Co., Ltd.; the talc powder is model BHS-807, produced by Quanzhou Xufeng Powder Raw Materials Co., Ltd.; the diatomite is model AG-WX4, produced by Qingdao Geruit Diatomite Co., Ltd.; the CAS number of 4,4'-diaminodibenzo-18-crown ether-6 is 31406-52-7.

[0041] The water dispersibility, defoaming and foam suppression performance of the high-efficiency solid defoamers for space station water treatment prepared in Examples 5-7 and Comparative Examples 1-9 were tested, and the test results are shown in Table 1.

[0042] Water dispersibility test: Pour 50g of water into a 500ml sealed bottle, add 3g of the solid defoamer prepared in Examples 5-7 and Comparative Examples 1-9, seal the bottle, and place it in an ultrasonic oscillator (frequency 30kHz) for ultrasonic dispersion. Record the time it takes for the defoamer to be completely dispersed in the water (without turbidity). Repeat the test 3 times and take the average value.

[0043] Defoaming performance test: Pour 100 ml of 1 wt% sodium dodecylbenzenesulfonate aqueous solution into a 500 ml graduated cylinder, bubble with nitrogen gas to the 500 ml mark, add 20 mg of the solid defoamer prepared in Examples 5-7 and Comparative Examples 1-9, and record the time when the foam is ≤10 ml. Repeat the test 3 times and take the average value as the final defoaming time.

[0044] Defoaming performance test: 100 ml of 1 wt% sodium dodecylbenzenesulfonate aqueous solution was poured into a 500 ml graduated cylinder, and 20 mg of the solid defoamer prepared in Examples 5-7 and Comparative Examples 1-9 was added. Nitrogen gas was then introduced at a flow rate of 2 L / min, and the time it took for the bubbles to reach the 500 ml mark was recorded. The test was repeated 3 times, and the average value was taken as the final defoaming time.

[0045] Table 1 Performance Test Data

[0046] As can be seen from Table 1, the solid defoamers for space station water treatment prepared in Examples 5-7 of this application have excellent water dispersibility, defoaming performance and foam suppression performance.

[0047] The surfactant added to the defoamer components prepared in Examples 5-7 of this application has a three-arm structure. Each arm incorporates a long, flexible ether chain, a hydroxyl group, a naphthalene ring, and a siloxane, forming a multi-point anchoring structure. The long, flexible ether chain on each arm endows the molecule with moderate migration ability in the aqueous phase, enabling it to rapidly accumulate at the gas-liquid interface. The hydroxyl group in the molecule provides a weak hydrophilic positioning effect, ensuring interfacial adsorption without excessive hydration, thereby avoiding the formation of a highly elastic stable bubble film. The introduced naphthalene ring rigid aromatic structure generates steric hindrance when oriented at the interface, disrupting the orderly accumulation of the original surfactant in the bubble film, reducing the mechanical strength and elasticity of the bubble film, thereby achieving rapid bubble breaking. At the same time, the siloxane segments at the arm ends have good compatibility and affinity with dimethyl silicone oil, effectively attracting the silicone oil to the bubble film interface and the interior of the film, leaving a hydrophobic silica layer at the interface after bubble breaking, thereby inhibiting the formation of new bubbles. The synergistic effect of the structural units in the surfactant molecule enables a continuous process of "rapid interface migration - foam structure disruption - efficient silicone oil introduction - construction of an interface hydrophobic layer", thereby simultaneously improving defoaming speed and foam suppression durability.

[0048] The surfactant used in Comparative Example 5 has a two-arm structure, and the molecule changes from a spatially multi-point anchoring configuration to an approximately linear structure. The anchoring ability at the gas-liquid interface is significantly weakened, and the molecule is more likely to be re-desorbed with the liquid phase flow, resulting in a shorter interfacial residence time. It is difficult to maintain a stable hydrophobic silica residue layer after bubble rupture, thus weakening the bubble suppression ability. At the same time, due to the reduction of effective anchoring points, the interfacial structure disturbance effect generated by the naphthalene ring and the traction effect of the siloxane segment on the dimethyl silicone oil both show a downward trend. The transport efficiency of silicone oil to the bubble film interface is reduced, making it difficult to quickly establish the local surface tension gradient and structural defects required for bubble rupture, and the bubble rupture rate is reduced. The surfactant used in Comparative Example 6 has a four-arm structure, which significantly increases the overall molecular volume, interfacial area, and conformational freedom. This leads to a decrease in the molecular migration rate in the aqueous phase, hinders diffusion to the gas-liquid interface, and slows down the interfacial enrichment rate, thus weakening the kinetic advantage required for rapid defoaming. At the same time, the four-arm configuration tends to form excessively dense multi-point adsorption at the interface, increasing the hydrophilic portion of the hydroxyl and ether chains, resulting in higher overall molecular hydrophilicity. The interfacial film tends to be continuous and stable, which in turn increases the viscoelasticity of the interfacial film, which is not conducive to rapid bubble rupture. In addition, the spatial arrangement of too many arms restricts the directional extension of siloxane segments, making it difficult for them to effectively embed into the dimethyl silicone oil phase. This reduces the efficiency of silicone oil introduction into the bubble film, thereby reducing the defoaming and foam-suppressing abilities of the defoamer.

[0049] The dispersant added to the components of the defoamer prepared in Examples 5-7 of this application is based on a crown ether, with benzene rings, secondary amines, ester groups, sulfonates, quaternary ammonium salts, and long-chain alkyl groups symmetrically introduced at both ends. This dispersant molecule, with the crown ether as its hydrophilic core structure, forms a stable hydration shell through weak complexation with metal ions in the aqueous phase, endowing the system with continuous hydration capability. The benzene rings and long-chain alkyl groups symmetrically introduced at both ends of the molecule act as hydrophobic anchoring groups, which can be firmly adsorbed onto the surface of dimethyl silicone oil and diatomaceous earth carrier particles, constructing a stable adsorption layer. The ester group and secondary amine structure provide interfacial compatibility, enabling the molecule to effectively spread without excessively densely packing at the solid-liquid interface. The amphiphilic structure of the sulfonate group and quaternary ammonium salt forms a highly hydrated double electric layer on the outside of the particles, generating a synergistic stabilizing effect of steric hindrance and weak electrostatic repulsion, thereby inhibiting particle aggregation and sedimentation. The synergistic effect of the various structural units in the dispersant molecule ensures the uniform dispersion of the defoamer particles in water. The dispersant used in Comparative Example 9 lacked a sulfonate structure and could not form a synergistic stabilizing effect with the quaternary ammonium salt structure, resulting in a decrease in the dispersing performance of the prepared defoamer.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A high-efficiency solid defoamer for space station water treatment, characterized in that, The ingredients include the following parts by weight: 25-35 parts dimethyl silicone oil, 5-10 parts water-soluble silicone oil, 4-5 parts surfactant, 0.5-1.5 parts dispersant, 1.5-2.5 parts anti-caking agent, 1-2 parts disintegrant, and 25-35 parts carrier; The surfactant is prepared by the following method: S1: 2-(1-bromovinyl)naphthalene reacts with 3,6,9,12,15,18-hexaoxane-1-thiol to form intermediate 1. S2: Intermediate 1 reacts with 3-aminopropyltrimethoxysilane to generate intermediate 2. S3: Intermediate 2 reacts with glycerol triglycidyl ether to generate a surfactant.

2. The high-efficiency solid defoamer for space station water treatment according to claim 1, characterized in that, In step S1, the molar ratio of 2-(1-bromovinyl)naphthalene to 3,6,9,12,15,18-hexaoxane-1-thiol is 1:(1.02-1.04).

3. The high-efficiency solid defoamer for space station water treatment according to claim 1, characterized in that, In step S2, the molar ratio of intermediate 1 to 3-aminopropyltrimethoxysilane is 1:(1.02-1.05).

4. The high-efficiency solid defoamer for space station water treatment according to claim 1, characterized in that, In step S3, the molar ratio of intermediate 2 to glycerol triglycidyl ether is (3.01-3.03):

1.

5. The high-efficiency solid defoamer for space station water treatment according to claim 1, characterized in that, The dispersant is prepared by the following method: N1: 4,4'-Diaminodibenzo-18-crown ether-6 reacts with β-(acryloyloxy)propionic acid to generate intermediate A; N2: Intermediate A reacts with lauryl hydroxysulfonate to form a dispersant.

6. The high-efficiency solid defoamer for space station water treatment according to claim 5, characterized in that, In step N1, the molar ratio of 4,4'-diaminodibenzo-18-crown ether-6 to β-(acryloyloxy)propionic acid is 1:2.

01.

7. The high-efficiency solid defoamer for space station water treatment according to claim 5, characterized in that, In step N2, the molar ratio of intermediate A to lauryl hydroxysulfonate betaine is 1:2.

03.

8. The high-efficiency solid defoamer for space station water treatment according to claim 1, characterized in that, The anti-caking agent is talc; the disintegrant is sodium chloride.

9. The high-efficiency solid defoamer for space station water treatment according to claim 1, characterized in that, The carrier is diatomaceous earth.

10. A method for preparing a high-efficiency solid defoamer for space station water treatment according to any one of claims 1-9, characterized in that, Includes the following steps: (1) Weigh out the following by weight: 25-35 parts of dimethyl silicone oil, 5-10 parts of water-soluble silicone oil, 4-5 parts of surfactant, 0.5-1.5 parts of dispersant, 1.5-2.5 parts of anti-caking agent, 1-2 parts of disintegrant, and 25-35 parts of carrier; (2) Mix dimethyl silicone oil and water-soluble silicone oil, heat and stir to mix evenly, cool down, add surfactant, dispersant, anti-caking agent and disintegrant and stir to mix evenly, add carrier and stir to obtain mixture; after drying, crushing and sieving the mixture, obtain high-efficiency solid defoamer for space station water treatment.

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