Preparation and application of a four-head bola type high-efficiency bactericide

Abstract

The application discloses a kind of four-head bola type high-efficiency bactericides preparation and application, belong to water treatment scientific field.The four-head bola type high-efficiency bactericides of the application has solubility as high as 1000mmol / L in water at room temperature, and contains amide group, is easy to degrade, and is friendly to environment.The four-head bola type high-efficiency bactericides of the application can reach more than 99.6% in bactericidal rate when concentration is greater than 150mg / L;When concentration is greater than 200mg / L, after three days, the algae killing rate can reach 99.8%.The hydrophobic group of the bactericide of the application is located between ionic head group, so that its foaming property is extremely poor, without adding defoaming agent in use, reduce the operation cost of system.At the same time, the four-head bola type bactericide in the application has good compatibility with common anionic scale inhibitor, the solution is clear and transparent after mixing, and the system still has excellent scale inhibition performance.

Description

Technical Field

[0001] This invention relates to the preparation and application of a four-headed Bola-type high-efficiency bactericide, belonging to the field of water treatment science. Background Technology

[0002] With the rapid development of the global economy and industrialization, water scarcity has become a global problem. In many industrial production processes, such as thermal power generation and pulp and paper manufacturing, the demand for large amounts of water further exacerbates the pressure of water shortages. One key approach to solving this problem is to promote the recycling of water resources. In industrial production, circulating cooling water systems are widely used to achieve efficient water use and water conservation. However, in long-term operating open-loop circulating cooling water systems, the intrusion of airborne microorganisms leads to their proliferation and water quality deterioration; simultaneously, with increasing concentration ratios, scaling occurs on the system walls and pipes. These factors can cause equipment corrosion, reduce heat transfer efficiency, and thus affect the normal operation of the system. Therefore, selecting appropriate chemical agents to inhibit microbial growth and scaling within the system is crucial for ensuring the effective utilization of water resources.

[0003] In circulating cooling water systems, common microorganisms include bacteria, fungi, and algae. Based on their bactericidal mechanisms, commonly used bactericides are classified into oxidizing bactericides (such as chlorine, active bromine, and dichloroisocyanuric acid) and non-oxidizing bactericides (such as chlorophenols and quaternary ammonium salts). While oxidizing bactericides have good bactericidal effects, they typically have higher toxicity and can cause secondary pollution to water bodies. With increasing environmental awareness, people are increasingly turning to less toxic quaternary ammonium salt surfactants; benzalkonium chloride and chlorpyrifos are the two most commonly used.

[0004] However, quaternary ammonium salt surfactants also present certain problems in practical use. First, aqueous solutions containing surfactants generate a large amount of foam during flow. To ensure the normal operation of the circulating water system, defoamers are usually added, increasing costs. Second, because the hydrophilic head groups of quaternary ammonium salt surfactants carry a positive charge, when mixed with some anionic scale inhibitors such as sodium polyacrylate, they easily combine strongly with anions through electrostatic attraction to form organic precipitates, which weakens the bactericidal and scale-inhibiting effects. Existing technology CN116395865A discloses an environmentally friendly phosphorus-free quaternary ammonium salt scale inhibitor and its application, which discloses a compound with a tetrameric quaternary ammonium salt structure. This compound has high solubility and good scale-inhibiting performance, but its bactericidal performance is poor and it is not easily degraded. At the same time, this technology does not solve the problem of surfactant foaming during flow.

[0005] The non-foaming property of bactericides and scale inhibitors reduces foaming problems in the system, which not only helps the normal operation of the water circulation system but also reduces the cost of adding defoamers. Furthermore, their easy degradability makes them more readily biodegradable after use, reducing environmental impact and aligning with the concept of sustainable development. These advantages collectively provide a feasible solution for novel bactericides in improving water resource utilization efficiency, reducing costs, and alleviating environmental burden. Therefore, developing novel quaternary ammonium salt bactericides with high bactericidal efficiency, good scale inhibition, high solubility, poor foaming properties, and easy degradation is of great significance for improving the service life of circulating water systems and conserving water resources. Summary of the Invention

[0006] Technical issues:

[0007] Quaternary ammonium salt bactericides utilize the negatively charged surface of bacteria for adsorption and destruction, making it less likely for bacteria to develop resistance. However, in practical applications, aqueous solutions of quaternary ammonium salt surfactants tend to generate excessive foam during flow, and when mixed with some anionic scale inhibitors, they are prone to precipitation, leading to a weakening of both bactericidal and scale-inhibiting effects. Therefore, designing and synthesizing a bactericide with high bactericidal efficiency, poor foaming properties, good compatibility, and high solubility is a key technical challenge in this field.

[0008] Technical solution: To achieve the above objectives, the present invention adopts the following technical solution:

[0009] The first objective of this invention is to provide a compound (a highly effective bactericide of the four-headed bola type), the structural formula of which is shown below:

[0010]

[0011] In one embodiment, the synthetic route of the four-headed Bola-type high-efficiency bactericide is as follows:

[0012]

[0013] In one embodiment, the synthesis step of the four-headed Bola-type high-efficiency bactericide (N2-C12-N2) includes:

[0014] (1) Tetradecanoic acid reacts with thionyl chloride to give compound 1;

[0015] (2) Compound 1 reacts with 3-dimethylaminopropylamine;

[0016] (3) Compound 2 and 3-bromopropyltrimethylammonium bromide were reacted to obtain the target product N2-C12-N2.

[0017] In one embodiment, the preparation method of the four-headed Bola-type high-efficiency bactericide (N2-C12-N2) is as follows:

[0018] (1) Tetradecanoic acid mixed with DMF, thionyl chloride was added until the system was clear, and distillation was performed to obtain compound 1;

[0019] (2) Triethylamine and 3-dimethylaminopropylamine were mixed, compound 1 was added, dichloromethane and acetone were added, and the mixture was recrystallized and dried to obtain compound 2.

[0020] (3) Compound 2 and 3-bromopropyltrimethylammonium bromide were mixed and reacted with ethanol to obtain a four-headed bola-type high-efficiency bactericide.

[0021] In one embodiment, the preparation method of the four-headed Bola-type high-efficiency bactericide (N2-C12-N2) is as follows:

[0022] (1) Place tetradecanoic acid in a three-necked flask, add a few drops of 50 μL DMF, and slowly add thionyl chloride at 60 °C. The acidic gas produced is absorbed by an aqueous sodium hydroxide solution. The reaction continues until the system becomes a clear liquid. After the reaction is complete, remove excess thionyl chloride by vacuum distillation to obtain pure compound 1.

[0023] (2) Triethylamine and 3-dimethylaminopropylamine were placed in a three-necked flask, and compound 1 was slowly added dropwise under ice bath. After the addition was complete, the mixture was reacted at room temperature (25°C) for 6 hours. After the reaction was completed, dichloromethane was added for extraction, the pH was adjusted to strong alkalinity with NaOH aqueous solution, acetone was added for recrystallization, and the product was dried to obtain pure compound 2.

[0024] (3) Synthesis of N2-C12-N2: Compound 2, 3-bromo-propyltrimethylammonium bromide and ethanol were placed in a single-necked flask and reacted at 92°C for 48-72 h. After cooling to room temperature, the solvent was removed by vacuum distillation, and the product was recrystallized three times with ethanol and acetone. After drying, pure N2-C12-N2 was obtained.

[0025] In one embodiment, the solubility of the compound is up to 1000 mmol / L.

[0026] A second object of the present invention is to provide a bactericidal scale inhibitor and penetrant comprising any of the above-mentioned compounds and anionic scale inhibitors.

[0027] In one embodiment, the concentration of the compound is 100 to 300 ppm (ppm is equivalent to mg / L).

[0028] In one embodiment, the concentration of the anionic scale inhibitor sodium polyacrylate is 200 ppm.

[0029] In one embodiment, the ratio of the compound to the anionic scale inhibitor is in the range of 1:2 to 3:2.

[0030] The present invention also provides the application of any of the above-mentioned compounds or any of the above-mentioned bactericides, scale inhibitors and penetrants in water treatment.

[0031] In one embodiment, the application includes, but is not limited to, industrial water treatment, cooling water systems, and drinking water disinfection.

[0032] Beneficial effects:

[0033] This invention synthesizes a tetra-headed bola-type compound using tetradecanoic acid as a raw material. The specific beneficial effects are as follows:

[0034] (1) The four-headed bola-type compound of the present invention has a solubility of up to 1000 mmol / L in water at room temperature, and the high solubility broadens its application field.

[0035] (2) The four-headed bola-type quaternary ammonium salt of the present invention has a concentrated charge, which can form a strong binding with the surface of bacteria and algae, and has a high efficiency of bactericidal and algae-killing performance. When the concentration is greater than 150 mg / L, the bactericidal rate can reach more than 99.6%; when the concentration is greater than 200 mg / L, the algae-killing rate can reach 99.8% in three days. Moreover, the bactericide is adsorbed onto the surface of bacteria through strong electrostatic effect, which makes it difficult for bacteria to develop drug resistance.

[0036] (3) The hydrophobic group of the four-headed Bola-type quaternary ammonium salt of the present invention is located between the ionic head groups. This can greatly weaken its surface activity without affecting its bactericidal and algicidal ability, resulting in extremely poor foaming properties. Therefore, no defoamer needs to be added during use, reducing the operating cost of the system. The four-headed Bola-type quaternary ammonium salt molecule of the present invention contains an amide group, which makes it easy to degrade and environmentally friendly.

[0037] (4) The four-headed Bola-type high-efficiency bactericide in this invention has good compatibility with common anionic scale inhibitor sodium polyacrylate. The solution after mixing the two is still clear and transparent, and the system still has excellent scale inhibition performance. Attached Figure Description

[0038] Figure 1 It has the molecular structure of N2-C12-N2.

[0039] Figure 2 The N2-C12-N2 is a hydrogen nuclear magnetic resonance spectrum.

[0040] Figure 3 The graph shows the surface tension of an N2-C12-N2 aqueous solution as a function of concentration (25℃).

[0041] Figure 4Photographs of the foam appearance of aqueous solutions of N2-C12-N2 and hexadecyltrimethylammonium bromide (CTAB) at concentrations of 100 mmol / L.

[0042] Figure 5 Photographs of the appearance of aqueous solutions of N2-C12-N2 at different concentrations and 200 ppm sodium polyacrylate after standing for 7 days.

[0043] Figure 6 Photographs showing the appearance of mixed aqueous solutions of CaCl2 and Na2CO3 with and without different concentrations of N2-Cl2-N2 and 200ppm sodium polyacrylate, with and without the addition of different concentrations of N2-Cl2-N2 and sodium polyacrylate.

[0044] Figure 7 Microscopic comparison images of CaCO3 formed in aqueous solutions of CaCl2 and Na2CO3 with and without different concentrations of N2-Cl2-N2 and 200 ppm sodium polyacrylate.

[0045] Figure 8 Photographs showing the appearance of aqueous solutions of N2-C12-N2 and tetrameric quaternary ammonium salt at equal concentrations of 50 mmol / L mixed with 1000 mmol / L CaCl2.

[0046] Figure 9 Photographs of the appearance of aqueous solutions of different concentrations of benzalkonium chloride and 200 ppm sodium polyacrylate after standing for 7 days. Detailed Implementation

[0047] Example 1: Synthesis of a four-headed Bola-type high-efficiency bactericide (N2-C12-N2)

[0048] 1. Synthesis of compound 1

[0049] Tetradecanoic acid (50 g, 0.19 mol) was placed in a 1000 mL three-necked flask, and a few drops of DMF were added. Thionyl chloride (52.95 g, 0.45 mol) was slowly added dropwise at 60 °C. The acidic gas produced was absorbed by an aqueous sodium hydroxide solution. The reaction continued until the system became a clear liquid and no bubbles were produced in the sodium hydroxide solution. After the reaction was completed, excess thionyl chloride was removed by vacuum distillation to obtain compound 1.

[0050] 2. Synthesize compound 2

[0051] Triethylamine (113.51 g, 1.16 mol) and 3-dimethylaminopropylamine (42.03 g, 0.41 mol) were placed in a three-necked flask. Compound 1 (55.2 g, 0.19 mol) was slowly added dropwise under ice bath conditions. After the addition was complete, the reaction was allowed to proceed at room temperature for 6 h. After the reaction was complete, 500 mL of dichloromethane was added for extraction. The pH was adjusted to a strongly alkaline state of 10–11 with NaOH aqueous solution. Acetone was added for recrystallization, and the mixture was dried to give compound 2, with a yield of 35%.

[0052] 3. Synthesis of N2-Cl2-N2

[0053] Compound 2 (6 g, 0.01 mol), 3-bromo-propyltrimethylammonium bromide (6.99 g, 0.03 mol), and 200 mL of ethanol were placed in a single-necked flask and reacted at 92 °C for 48 h. After cooling to room temperature, the solvent was removed by vacuum distillation, and the mixture was recrystallized three times with ethanol and acetone. After drying, a white powdery solid N2-C12-N2 was obtained, with a yield of 52%. The molecular structure is shown below. Figure 1 As shown, the hydrogen nuclear magnetic resonance spectrum is as follows: Figure 2 As shown.

[0054] 4. Determination of the structure and purity of N2-C12-N2

[0055] Weigh 10 mg of N2-C12-N2 and place it in an NMR tube, then dissolve it in deuterated reagent DMSO. Perform NMR analysis using an Aduance III NMR spectrometer at 25°C. 1 H NMR test. 1 The resonant frequency of H is 400MHz. From... Figure 2 The hydrogen nuclear magnetic resonance spectrum of N2-C12-N2 shows that the chemical shifts of each hydrogen atom are consistent with the target product, and there are no impurity peaks on the spectrum, indicating that the product has reached a very high purity and meets the requirements of subsequent experiments.

[0056] 1H NMR (400MHz, DMSO) δ8.06(t,2H,C1-1H,C18-1H),3.30,3.40(m,12H,C27-3H,C28-3H,C29-3H,C30-3H),3.16(s,18 H,C39-3H,C40-3H,C41-3H,C42-3H,C43-3H,C44-3H),3.12(s,4H,C23-2H,C14-2H),3.09(s,12H,C21-2H,C31-2H, C33-2H,C25-2H,C35-2H,C37-2H),2.23(q,4H,C32-2H,C36-2H),2.09(t,4H,C3-2H,C14-2H),1.85(q,4H,C20-2H, C24-2H), 1.48 (q, 4H, C4-2H, C13-2H), 1.24 (s, 16H, C5-2H, C6-2H, C7-2H, C8-2H, C9-2H, C10-2H, C11-2H, C12-2H).

[0057] Example 2: Performance Testing of N2-C12-N2

[0058] 1. Determination of the solubility of N2-C12-N2

[0059] The solubility of compound N2-C12-N2 prepared in Example 1 was determined by observation. A certain amount of N2-C12-N2 was weighed into a 10 mL column-shaped vial, 5 mL of ultrapure water was added, and the solution was heated in a dry bath at 65 °C until clear and transparent. Then, it was placed in a constant temperature oven at 25 °C for 48 h to equilibrate, and the phenomenon was observed. If no solid precipitated, the sample was added to the solution, and the above steps were repeated until a very small amount of solid precipitated at 25 °C; if solid precipitated, solvent was added until it was completely dissolved. The solubility of N2-C12-N2 was thus obtained.

[0060] At room temperature, N2-C12-N2 has a solubility of up to 1000 mmol / L in water, which greatly expands the application fields of N2-C12-N2.

[0061] 2. Determination of surface tension of N2-Cl2-N2 aqueous solution (25℃)

[0062] Before the test, N2-C12-N2 prepared in Example 1 was used to prepare a series of N2-C12-N2 solutions, which were then placed in a 25°C incubator for equilibration for 12 hours. The specific test method is as follows: First, a weighing dish was prepared... 16 mL of ultrapure water was added to calibrate the ring parameters. Then, a series of N2-C12-N2 solutions of varying concentrations were added sequentially to bring the solution concentration in the weighing dish to the required value. After equilibration for 10 min, the surface tension was measured using the Du Noüy ring method. The test temperature was 25 ± 0.1℃, and the average of three measurements was taken to ensure an error within 0.1 mN·m. -1 Within.

[0063] Figure 3 The graph shows the surface tension of an N2-C12-N2 aqueous solution as a function of concentration. It can be seen from the graph that the CMC of N2-C12-N2 is as high as 48.5 mmol / L, and the γ... CMC Up to 50.6 mN·m -1 Its surface activity is poor, which is not conducive to foam formation.

[0064] 3. Foaming performance test of 100 mmol / L N2-C12-N2 aqueous solution

[0065] Take the N2-C12-N2 prepared in Example 1, and add 5 mL of a 100 mmol / L N2-C12-N2 aqueous solution to a 50 mL stoppered graduated cylinder. Observe the foaming after vigorously shaking up and down 25 times at 25°C.

[0066] Figure 4 Photographs show the foam appearance of 100 mmol / L aqueous solutions of N2-C12-N2 and hexadecyltrimethylammonium bromide (CTAB). The images show that CTAB has strong foaming properties, while the same concentration of N2-C12-N2 produces almost no foam. This indicates that N2-C12-N2 has extremely poor foaming properties, which can prevent the generation of excessive foam in practical use and reduce the need for defoamers.

[0067] 4. Sterilization performance test of N2-C12-N2

[0068] The N2-C12-N2 prepared in Example 1 was tested using Yangtze River water. Following GB / T 22595-2008 "Evaluation Method for Biocidal Efficiency—Heterotrophic Bacteria," a static heterotrophic bacteria method was used for sterilization experiments, and the sterilization effect was evaluated based on the bacterial count. The culture temperature was (29±1)℃, and the total bacterial count was measured after 72 hours of constant temperature. The results showed that when the N2-C12-N2 concentration was greater than 150 mg / L, the sterilization rate reached over 98.4%, demonstrating highly efficient sterilization performance.

[0069] 5. Algae-killing performance test of N2-C12-N2

[0070] In Example 1, 50 mL of the mixed algal solution was added to a 500 mL Erlenmeyer flask containing the N2-C12-N2 prepared in the experiment. Then, 20 mL of water was added. After two days of incubation at room temperature under a light intensity of 3000 lux, the algal cell count reached 10. 6 / cubic meter or more. A certain concentration of N2-C12-N2 solution was added, and the change in algal cell content over time was observed. The results showed that when the concentration of N2-C12-N2 was greater than 200 mg / L, the algae removal rate could reach 99.8% after three days, demonstrating a good algae removal effect.

[0071] Example 3: Preparation of a composite bactericidal, scale-inhibiting, and penetrant agent using N2-C12-N2

[0072] The N2-C12-N2 prepared in Example 1 was mixed with 200 ppm sodium polyacrylate at concentrations of 100, 200, and 300 ppm respectively to obtain composite bactericidal, scale-inhibiting, and penetrant agents with different N2-C12-N2 concentrations.

[0073] Place the bactericidal, scale-inhibiting, and penetrant agent in a 25°C constant temperature chamber for 7 days.

[0074] Figure 5 Photographs show the appearance of aqueous solutions of different concentrations of N2-C12-N2 mixed with 200 ppm sodium polyacrylate after standing for 7 days. The images show that the mixed solutions are all clear and transparent, indicating that N2-C12-N2 has good compatibility with the anionic polymer.

[0075] Example 4: Scale inhibition performance test of composite bactericidal scale inhibitor penetrant

[0076] The composite bactericidal, scale-inhibiting and penetrant agents with different N2-Cl2-N2 concentrations prepared in Example 3 were added to 5 mmol / L CaCl2, followed by 5 mmol / L Na2CO3. After mixing evenly, macroscopic photographs were taken.

[0077] Figure 6 The images show the appearance of equimolar concentration (5 mmol / L) CaCl2 and Na2CO3 aqueous solutions with and without the addition of different concentrations of N2-C12-N2 and 200 ppm sodium polyacrylate. As can be seen from the figures, compared to the control group, the system with the addition of different concentrations of N2-C12-N2 and 200 ppm sodium polyacrylate aqueous solutions exhibits higher transmittance, indicating the formation of less CaCO3 precipitate.

[0078] Example 5: Effect of composite bactericidal, scale-inhibiting, and penetrant agent on the morphology of CaCO3

[0079] The composite bactericidal, scale-inhibiting and penetrating agents with different N2-Cl2-N2 concentrations prepared in Example 3 were added to 5 mmol / L CaCl2, followed by 5 mmol / L Na2CO3. After mixing evenly, the mixture was placed in a constant temperature oven at 70℃ for 4 hours. The resulting CaCO3 precipitate was then photographed using a microscope.

[0080] Figure 7 Microscopic comparison images show the formation of CaCO3 in equimolar concentration (5 mmol / L) CaCl2 and Na2CO3 aqueous solutions with and without the addition of different concentrations of N2-C12-N2 and 200 ppm sodium polyacrylate. The images show that the CaCO3 crystals in the control group exhibit a regular calcite structure, and the crystals accumulate to form calcium carbonate scale. After adding the N2-C12-N2 and sodium polyacrylate solution, the CaCO3 crystals transform from a calcite-shaped structure to an irregular, spherical structure. This is because the scale inhibitor adsorbs onto the surface of the CaCO3 crystals, preventing normal crystal growth, and ultimately dispersing them in the water as loose, tiny crystals. This demonstrates that the scale inhibitor sodium polyacrylate, when mixed with the highly effective bactericide N2-C12-N2, still exhibits excellent scale inhibition performance.

[0081] Example 6: Bactericidal performance test of composite bactericidal and scale-inhibiting penetrant

[0082] The composite bactericidal, scale-inhibiting, and penetrant prepared in Example 3 was used. The test water was Yangtze River water. Following GB / T22595-2008 "Evaluation Method for the Efficiency of Biocides—Heterotrophic Bacteria," a static heterotrophic bacteria method was employed for bactericidal experiments, and the bactericidal effect was evaluated based on the bacterial count. The culture temperature was (29±1)℃, and the total bacterial count was measured after 72 hours of constant temperature. The results showed that when the N2-Cl2-N2 concentration in the composite bactericidal, scale-inhibiting, and penetrant was equal to 150 mg / L, the bactericidal rate of the composite bactericidal, scale-inhibiting, and penetrant could reach over 99.4%, demonstrating highly efficient bactericidal performance.

[0083] Example 7: Algae-killing performance test of composite bactericidal, scale-inhibiting, and penetrant agent

[0084] The composite bactericidal, scale-inhibiting, and penetrant prepared in Example 3 was added to a 500mL Erlenmeyer flask along with 50mL of mixed algal solution and 20mL of water. After two days of incubation at room temperature under a light intensity of 3000 lux, the algal cell content reached 10. 6 The algae count was above 100 cells / cubic meter. A certain concentration of a compound bactericidal, scale-inhibiting, and penetrant was added, and the change in algae cell content over time was observed. The results showed that when the N2-Cl2-N2 content in the compound bactericidal, scale-inhibiting, and penetrant was greater than 200 mg / L, the algae removal rate reached 99.7% after three days, demonstrating a good algae removal effect.

[0085] Example 8: Application of composite bactericidal, scale-inhibiting, and penetrant agents in water treatment

[0086] The composite bactericidal, scale-inhibiting, and penetrating agent prepared in Example 3 was used. The test water was Yangtze River water. 100 mL of Yangtze River water was added to a 500 mL conical flask, and then a certain concentration of composite bactericidal, scale-inhibiting, and penetrating agent was added to make the final concentration of N2-C12-N2 150 mg / L and the final concentration of sodium polyacrylate 200 mg / L. After being kept at a constant temperature for 72 h, the total number of bacteria and algae cells and the amount of sediment in the water were measured.

[0087] The results showed that the sterilization and algae removal efficiency in the cooling water reached over 99%, and the water was clear with no foam or sediment.

[0088] Comparative Example 1: Performance Testing of Tetrameric Quaternary Ammonium Salts

[0089] 1. Preparation of tetrameric quaternary ammonium salts

[0090] The synthesis route is shown below:

[0091]

[0092] 3-Bromopropyltrimethylammonium bromide (33 g, 0.13 mol) and N,N,N',N'-tetramethylethylenediamine (7.0 g, 0.06 mol) were added to a 250 mL single-necked flask. The mixture was stirred at 80 °C for 20 h, then heating was stopped. After the reaction mixture cooled, it was filtered under reduced pressure. The resulting solid was recrystallized twice, filtered again, and then dried under vacuum to obtain a white powder, which was the target product, the oligomeric quaternary ammonium salt scale inhibitor.

[0093] 2. The bactericidal properties of tetrameric quaternary ammonium salts:

[0094] The test water was Yangtze River water. Following GB / T22595-2008 "Evaluation Method for the Efficacy of Biocides—Heterotrophic Bacteria", a static heterotrophic bacteria sterilization experiment was conducted, and the sterilization effect was evaluated based on the bacterial count. The culture temperature was (29±1)℃, and the total bacterial count was determined after 72 hours of constant temperature.

[0095] The results showed that when the concentration of the tetrameric cationic scale inhibitor was 120 mg / L, the bactericidal rate could reach 69.2%, while when the concentration of N2-Cl2-N2 was 100 mg / L, the bactericidal rate could reach more than 98.4%, demonstrating more efficient bactericidal performance.

[0096] 3. Salt tolerance of tetrameric quaternary ammonium salts:

[0097] 50 mmol / L of N2-C12-N2 prepared in Example 1 and 50 mmol / L of tetrameric quaternary ammonium salt were mixed with 1000 mmol / L of CaCl2 and placed in a constant temperature incubator at 25°C for 7 days.

[0098] Figure 8 The images show the appearance of aqueous solutions of N2-C12-N2 and tetraquaternary ammonium salt at concentrations of 50 mmol / L and 1000 mmol / L CaCl2, respectively. As can be seen from the images, the N2-C12-N2 solution remains clear and transparent even under high salt conditions, while the tetraquaternary ammonium salt precipitates, indicating that N2-C12-N2 has better salt tolerance.

[0099] Comparative Example 2: Performance Testing of a Composite Bactericidal, Scale-Inhibiting, and Penetrating Agent Prepared Using Benzalkonium Chloride

[0100] 100, 200, and 300 ppm of benzalkonium chloride were mixed with 200 ppm of sodium polyacrylate to obtain composite bactericidal, scale-inhibiting, and penetrant agents with different benzalkonium chloride concentrations.

[0101] Place the bactericidal, scale-inhibiting, and penetrant agent in a 25°C constant temperature chamber for 7 days.

[0102] Figure 9 Photographs show the appearance of aqueous solutions of different concentrations of benzalkonium chloride and 200 ppm sodium polyacrylate after standing for 7 days. The images show that the mixed solutions are all turbid with precipitation, indicating that benzalkonium chloride and anionic polymers do not have good compatibility.

Claims

1. A compound with the following molecular structure: 。 2. A bactericidal, scale-inhibiting, and penetrating agent, characterized in that, The bactericidal scale inhibitor contains the compound of claim 1 and an anionic scale inhibitor; the anionic scale inhibitor is sodium polyacrylate; the concentration of the compound is 100~300 ppm, and the concentration of the anionic scale inhibitor is 200 ppm~500 ppm.

3. The application of the compound of claim 1 in water treatment.

4. The application according to claim 3, characterized in that, The applications include industrial water treatment, cooling water systems, and drinking water disinfection.

5. The application of the bactericidal, scale-inhibiting, and penetrant agent according to claim 2 in water treatment.

6. The application according to claim 5, characterized in that, The applications include industrial water treatment, cooling water systems, and drinking water disinfection.

Images