Oil stain cleaning agent, preparation method thereof and oil stain cleaning method

Abstract

The invention discloses a greasy dirt cleaning agent, a preparation method thereof and a greasy dirt cleaning method, and belongs to the technical field of greasy dirt cleaning. 1 to 3 wt% of isomeric octo-carbon polyoxyethylene polyoxypropylene ether; 1-2 wt% of alkyl glycoside; d, 0.5 to 1.0 wt% of limonene; 1-3 wt% of an anionic surfactant; 2 to 4 wt% of other nonionic surfactants; 0.5-1.0 wt% of a buffer stabilizer; 1-3 wt% of a builder; and the balance of deionized water. And the pH range is 7-9. The oil stain cleaning agent is good in oil stain removal effect.

Description

Technical Field

[0001] This invention application belongs to the field of oil stain cleaning technology, specifically relating to oil stain cleaning agents and their preparation methods, and oil stain cleaning methods. Background Technology

[0002] Oil stain removers are widely used chemical agents in industrial, catering, and household fields, primarily used to remove grease, dirt, and other contaminants from the surfaces of machinery, kitchenware, clothing, etc. Based on their cleaning mechanism and main ingredients, general-purpose oil stain removers can typically be divided into the following three categories: (1) Strong alkaline cleaning agents. Strong alkaline cleaning agents use strong alkaline substances such as sodium hydroxide, sodium carbonate, or sodium silicate as the main components. They saponify grease through alkaline hydrolysis and remove heavy oil stains by mechanical means such as spraying or soaking. These cleaning agents have a strong ability to remove heavy oil stains from industrial equipment and catering utensils, and are widely used in machinery manufacturing, ship repair, and large catering industries. However, the strong corrosiveness of strong alkaline cleaning agents may damage the objects being cleaned (such as aluminum alloy and stainless steel surfaces), and also poses a significant safety hazard to the user's skin and respiratory tract. In addition, the discharge of strong alkaline waste liquid may pollute the environment, limiting its application in homes and in scenarios with high environmental protection requirements. (2) Solvent-based cleaning agents. Solvent-based cleaning agents use organic solvents (such as petroleum ether, kerosene, limonene, or alcohol ether compounds) as the main components, and utilize the solvent's dissolving effect on grease to remove oil stains. These cleaning agents have good removal effects on various oil stains (such as mineral oil and vegetable oil) and are often used for precision machinery cleaning or special industrial scenarios. However, organic solvents are usually flammable and explosive, and some solvents (such as aromatic hydrocarbons) are toxic. Long-term use may cause harm to human health and the environment. In addition, solvent-based cleaning agents are expensive, and the emission of volatile organic compounds (VOCs) is subject to strict environmental regulations (such as the "Emission Standard for Volatile Organic Compounds" GB 37822-2019), which greatly restricts their application in homes and public places. (3) Surfactant-based cleaning agents. Surfactant-based cleaning agents use anionic, nonionic, cationic, or amphoteric surfactants (such as sodium alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, and cocamidopropyl betaine) as core components. They decompose oil stains into fine particles through wetting, penetration, emulsification, and dispersion, and then remove the dirt from the carrier through mechanical force (such as scrubbing and rinsing). These cleaning agents have the advantages of being easy to use, mild and low-irritant, and inexpensive, and are widely used in household kitchens, catering utensils, and clothing cleaning. However, surfactant-based cleaning agents have limited effectiveness in removing heavy oil stains (such as high-temperature carbonized oil stains), requiring long soaking times or repeated washing, resulting in low efficiency. In addition, some surfactants easily react with calcium and magnesium ions in hard water environments to form precipitates, reducing their detergency; some formulations have insufficient dispersion and anti-redeposition properties for oil stains, which may lead to dirt re-settling after cleaning.

[0003] In recent years, with the increasing awareness of environmental protection and the development of green chemistry, research on oil stain cleaners at home and abroad has focused on developing efficient, environmentally friendly, and low-toxicity formulations. For example, some patent documents disclose cleaners based on bio-based surfactants (such as alkyl glycosides) or natural terpene solvents (such as D-limonene), attempting to balance detergency and environmental friendliness; other studies have optimized formulations by compounding surfactants, chelating agents, and detergent builders to improve hard water resistance and dispersibility. However, the existing technologies still have the following shortcomings: (1) Insufficient balance between cleaning efficiency and mildness: strong alkaline and solvent-based cleaning agents have strong cleaning power but poor safety, while surfactant-based cleaning agents are mild but not effective against heavy oil stains; (2) Limited anti-redeposition performance: some cleaning agents cannot effectively prevent oil stains from settling back during the cleaning process, affecting the thoroughness of cleaning; (3) Contradiction between environmental protection and cost: green formulas (such as bio-based surfactants) are expensive and difficult to promote on a large scale; solvent-based cleaning agents with high volatile organic compounds (VOCs) face environmental regulations; (4) Limited applicable scenarios: existing cleaning agents are mostly targeted at specific oil stains or carriers and lack versatility, such as insufficient compatibility between household and industrial scenarios.

[0004] In summary, existing oil stain cleaners still have room for improvement in terms of cleaning efficiency, safety, environmental friendliness, and anti-redeposition properties. Therefore, developing an oil stain cleaner that is highly efficient, mild, environmentally friendly, and possesses excellent dispersing and anti-redeposition capabilities is of significant practical importance and market demand. Summary of the Invention

[0005] This invention provides an oil stain cleaning agent and its preparation method, as well as an oil stain cleaning method, aiming to partially or completely solve the technical problems such as insufficient balance between decontamination efficiency and gentleness, limited anti-redeposition performance, contradiction between environmental friendliness and cost, and limited applicability. To achieve the objectives of this invention, the technical solution is as follows: Firstly, an oil stain cleaner includes: Carbon dot surfactant 0.1-0.35wt; isomeric octadecanopolyoxyethylene polyoxypropylene ether 1-3wt; ​​alkyl glycoside 1-2wt; D-limonene 0.5-1.0wt; anionic surfactant 1-3wt; ​​other nonionic surfactants 2-4wt; buffer stabilizer 0.5-1.0wt; detergent builder 1-3wt; ​​balance is deionized water; pH range is 7-9.

[0006] Preferably, the carbon dots in the carbon dot surfactant package appear spherical in a transmission electron microscope, with a particle size ranging from 1 to 5 nm.

[0007] Preferably, the anionic surfactant comprises one or more of the following: sodium alkyl sulfonate, α-olefin sulfonate, alkyl glycerol ether sulfonate, and fatty alcohol sulfate salt; and / or, other nonionic surfactants comprise one or more of the following: fatty alcohol polyoxyethylene ether, PPG2 butanol polyether, dodecyl dimethylamine oxide, and fatty acid methyl ester ethoxylate; and / or, the detergent builder comprises one or more of the following: disodium EDTA, sodium gluconate, and sodium citrate; and / or, the buffer stabilizer comprises one or more of the following: sodium dihydrogen phosphate, sodium bicarbonate, sodium carbonate, and sodium silicate.

[0008] Secondly, a method for preparing an oil stain cleaning agent, comprising: Step S100: Prepare carbon dot surfactant, obtain isomeric octane polyoxyethylene polyoxypropylene ether, mix isomeric octane polyoxyethylene polyoxypropylene ether and carbon dot surfactant, then add alkyl glycoside to form a mixture, and sonicate the mixture under the following conditions: frequency 40-100kHz, power 3.0-10.0kW, 10-60 minutes. Step S200: After ultrasonic treatment, add D-limonene, anionic surfactant, other nonionic surfactant, buffer stabilizer, detergent aid and deionized water to the mixture, stir to make the mixed solution uniform, and adjust the pH value of the mixed solution system to 7-9. Step S300: Sample and test the pH value, surface tension, and detergency of the product. After confirming that it meets the requirements, the finished oil stain cleaning agent is obtained.

[0009] Preferably, in step S100, the preparation of carbon dot surfactant includes: uniformly mixing vegetable oil and hydrogen peroxide in N,N-dimethylformamide to form a homogeneous solution, pyrolyzing at 180°C for 4-8 hours; after the reaction is completed, cooling to room temperature, collecting the crude product, purifying it by dialysis, and then rotary evaporating the resulting solution to obtain carbon dot surfactant.

[0010] Preferably, in step S100, ultrasonic treatment generates ultrasonic cavitation effect to produce microbubbles, which disperses carbon dots. Under the ultrasonic-induced shear force and shock wave, the negative charge of the carbon dots accelerates the formation of a stable mixed micelle system of carbon dots, isomeric octane polyoxyethylene polyoxypropylene ether, and alkyl glycoside, reducing the water-oil interfacial tension. The hydrophobic segment of the isomeric octane polyoxyethylene polyoxypropylene ether includes PPO segments and isomeric octane groups. The hydrophobic segment of the isomeric octane polyoxyethylene polyoxypropylene ether combines with the hydrophobic region of the carbon dots through hydrophobic interaction.

[0011] Preferably, the anionic surfactant comprises one or more of the following: sodium alkyl sulfonate, α-olefin sulfonate, alkyl glycerol ether sulfonate, and fatty alcohol sulfate salt; and / or, other nonionic surfactants comprise one or more of the following: fatty alcohol polyoxyethylene ether, PPG2 butanol polyether, dodecyl dimethylamine oxide, and fatty acid methyl ester ethoxylate; and / or, the detergent builder comprises one or more of the following: disodium EDTA, sodium gluconate, and sodium citrate; and / or, the buffer stabilizer comprises one or more of the following: sodium dihydrogen phosphate, sodium bicarbonate, sodium carbonate, and sodium silicate.

[0012] Thirdly, a method for cleaning oil stains on hard surfaces, using any of the oil stain cleaning agents described in the first aspect or employing any of the oil stain cleaning agent preparation methods in the second aspect, includes: Step S10: Apply the oil stain cleaner to the hard surface oil stain; Step S20: Leave at room temperature for 20-30 seconds to wipe and clean the oil stains on the hard surface.

[0013] Preferably, in step S10, the oil stain cleaning agent is applied directly during use; Alternatively, dilute with water at a volume ratio of 1:1 to 1:10 before application.

[0014] Preferably, the hard surface includes a metal, ceramic, glass, or plastic surface; and / or, wiping and cleaning are performed using a cleaning cloth or brush followed by rinsing with water.

[0015] Compared with the prior art, the beneficial effects of this invention application are as follows: (1) In this invention application, firstly, the oil stain cleaner achieves efficient removal of heavy oil stains by using mild carbon point surfactants and alkyl glycosides, combined with the strong dissolving ability of D-limonene, while maintaining mildness and avoiding corrosion or irritation to the cleaned surface or user; the pH value is controlled within the range of 7-9 to ensure its mildness, and the use of bio-based surfactants (such as alkyl glycosides) and natural solvents (such as D-limonene) significantly reduces environmental pollution, controls costs while maintaining high cleaning efficiency, and makes it competitive in the market; in addition, the high adsorption capacity of carbon point surfactants further stabilizes the dispersed oil stain particles, improves the anti-redeposition performance, and ensures long-lasting cleaning effect. Through the combination of various surfactants and additives, the oil stain cleaner can effectively remove different types of oil stains (such as mineral oil, vegetable oil, and animal oil), providing an efficient, mild, environmentally friendly and multi-purpose cleaning solution.

[0016] (2) In this invention application, firstly, the high specific surface area and nano-characteristics of carbon dot surfactants significantly enhance the penetration and dispersion ability of oil stains. Combined with the synergistic effect of anionic and nonionic surfactants, it improves the removal efficiency of various oils, proteins and complex dirt. The addition of D-limonene enhances the dissolution effect on stubborn oil stains, making the cleaning agent suitable for various scenarios such as industrial and household use. In addition, stepwise mixing and precise pH control (7-9) ensure the uniform dispersion and chemical stability of each component. The buffer stabilizer effectively prevents pH drift. The detergent aid reduces hard water interference by chelating metal ions, extends the product shelf life and maintains long-term use effect. The use of green surfactants such as alkyl glycosides and D-limonene reduces the environmental impact of the product. The mildness of nonionic surfactants reduces irritation to the skin and the cleaned surface. Furthermore, the stepwise addition and stirring process is simple and easy to control, suitable for industrial production. Accurate proportioning and post-processing steps (such as filtration and testing) ensure consistent product quality, while optimizing raw material utilization and reducing production costs. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of the method for preparing the oil stain cleaning agent according to the present invention. Figure 2 This is a schematic flowchart of the hard surface oil stain cleaning method of this invention application; Figure 3 This is a schematic diagram illustrating the principle of testing the volatile organic compound value of the oil stain cleaning agent according to the present invention. Figure 4 This is a schematic diagram of the mixture of carbon dot surfactant, isomeric octane polyoxyethylene polyoxypropylene ether, and alkyl glycoside after ultrasonic treatment according to this invention application.

[0018] Figure 5 This is a TIC diagram of Comparative Example 1 of this application; Figure 6 This is a TIC diagram of Comparative Example 2 of this application; Figure 7 This is a TIC diagram of Comparative Example 3 of this invention application; Figure 8 This is a TIC diagram of Embodiment 1 of this invention application; Detailed Implementation

[0019] The technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, not all of them; "multiple" includes one, two, or more than one; the numerical range can be understood to include at least the endpoint values, and can also be reasonably understood according to the actual situation; based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. It is worth noting that the raw materials used in this invention are all common commercially available products, and their sources are not specifically limited.

[0020] Commercially available oil stain cleaners typically consist of active ingredients (such as surfactants), additives (such as alkaline substances and chelating agents), anti-settling agents, fillers, and fragrances. Their mechanism of action is based on physicochemical processes, including wetting, penetration, emulsification, dispersion, and mechanical action.

[0021] The oil stain cleaning process generally consists of two stages: (1) under the action of the cleaning agent, the oil stains detach from their carrier (such as the surface of metal, ceramic, or fabric); (2) the detached oil stains are dispersed and suspended in the cleaning medium (such as an aqueous solution) to prevent them from redepositing. However, oil stain cleaning is a reversible process. The oil stains dispersed or suspended in the medium may redeposit onto the surface of the object being cleaned due to insufficient performance of the cleaning agent, thereby reducing the cleaning effect. Therefore, oil stain cleaning agents not only need to have the ability to detach oil stains from the carrier, but also need to have excellent dispersion, suspension, and anti-redeposition properties to ensure the efficiency and thoroughness of the cleaning process.

[0022] Oil stain cleaner Firstly, an oil stain cleaner comprises: 0.1-0.35 wt% carbon dot surfactant; 1-3 wt% isomeric octane polyoxyethylene polyoxypropylene ether; 1-2 wt% alkyl glycoside; 0.5-1.0 wt% D-limonene; 1-3 wt% anionic surfactant; 2-4 wt% other nonionic surfactants; 0.5-1.0 wt% buffer stabilizer; 1-3 wt% detergent builder; the balance being deionized water; and a pH range of 7-9.

[0023] Understandably, carbon dots, as nanoscale surfactants, have particle sizes ranging from 1 to 10 nm and possess a high specific surface area, thus providing numerous interfacial contact points and significantly enhancing their adsorption capacity for oil molecules. The surface of carbon dots is rich in functional groups such as carboxyl groups (-COOH) and hydroxyl groups (-OH). These groups, upon dissociation in water, impart a negative charge to the carbon dots, increasing their hydrophilicity and promoting their interaction with aqueous solutions. As ionic surfactants, carbon dots can reduce the water-oil interfacial tension, promoting the emulsification and dispersion of oil. However, due to the electrostatic repulsion caused by the negative surface charge, carbon dots struggle to form stable micelle structures independently, thus limiting their detergency when used alone.

[0024] Nevertheless, the nanoscale size and high surface activity of carbon dots allow them to effectively adsorb and disperse oil molecules through electrostatic and van der Waals forces. Their abundant functional groups provide multiple adsorption sites, further enhancing the encapsulation and dispersion effects. Furthermore, the high specific surface area and functional groups of carbon dots can capture free oil molecules, preventing them from re-adhering to the cleaned surface. The electrostatic repulsion generated by the negative charge helps maintain the dispersion of oil in the aqueous phase, prolonging the cleaning effect. Carbon dots also exhibit good biocompatibility and low toxicity, reducing potential harm to humans and the environment, and meeting the requirements of green chemistry.

[0025] It is understandable that isomeric octane polyoxyethylene polyoxypropylene ether (CA) is a nonionic surfactant whose molecular structure includes hydrophilic polyoxyethylene (PEO) segments, hydrophobic polyoxypropylene (PPO) segments, and isomeric octane groups. The PEO segments ensure CA's solubility and stability in water, facilitating its dispersion in the aqueous phase; the PPO segments and isomeric octane groups exhibit strong affinity for oil molecules, enhancing adsorption capacity. The isomeric octane structure further enhances CA's wettability and permeability, enabling it to penetrate deep into the oil contaminants on complex surfaces. CA can spontaneously form stable micelle structures, where the hydrophobic core effectively encapsulates oil molecules, while the hydrophilic outer layer ensures stable dispersion in water. By reducing the water-oil interfacial tension, CA promotes the emulsification and dispersion of oil contaminants, improving cleaning efficiency. Its hydrophilic and hydrophobic portions work synergistically to form a stable emulsion, facilitating the removal of oil contaminants from the surface; the isomeric octane structure accelerates the dissolution and removal of dirt in tiny crevices. As a nonionic surfactant, CA is less irritating to the skin and eyes, making it suitable for mild cleaning agent formulations and reducing potential damage to cleaned surfaces, thus making it suitable for a variety of applications.

[0026] As is understandable, alkyl glycosides (APGs) are nonionic surfactants derived from natural ingredients. Their molecular structure includes a hydrophilic sugar moiety (derived from natural sugars) and a hydrophobic alkyl chain (derived from fatty alcohols). The sugar moiety provides excellent water solubility, ensuring APG's stability in the aqueous phase; the alkyl chain has an affinity for oil molecules, enhancing detergency. APGs are made from renewable resources and have good biodegradability, making them an ideal choice for environmentally friendly cleaning agents. By reducing interfacial tension, APGs can form stable micelle structures, dispersing oil molecules into the aqueous phase. These micelles effectively encapsulate oil, improving cleaning efficiency and forming a stable emulsion system that prevents redeposition of oil. APGs are readily biodegradable, have minimal environmental impact, and are less irritating to skin and eyes, making them particularly suitable for household and personal care products.

[0027] Understandably, anionic surfactants, such as sodium alkylbenzene sulfonate, provide strong detergency and foaming properties, and work synergistically with nonionic surfactants to further enhance cleaning performance. Understandably, D-limonene is a natural terpene solvent with strong oil-dissolving ability, which can effectively break down heavy oil stains and bring a citrus fragrance, thus enhancing the user experience. Understandably, other nonionic surfactants, such as fatty alcohol polyoxyethylene ethers, can further optimize the emulsifying, dispersing, and wetting abilities of cleaning agents, thereby enhancing their overall performance. Understandably, buffer stabilizers, such as sodium bicarbonate, maintain the pH of the cleaning agent within the range of 7-9 to ensure its stability and gentleness.

[0028] Understandably, detergent builders, such as disodium EDTA and sodium gluconate, prevent hard water interference by chelating calcium and magnesium ions in water, while also improving anti-redeposition performance.

[0029] In this invention application, a large amount of deionized water and moderately priced surfactants are used, which effectively reduces the cost of oil stain cleaners, making the formulation cost reasonable, and the efficient cleaning reduces the amount used, further improving cost-effectiveness. At the same time, the pH value is in the range of 7-9, which is neutral to weakly alkaline, avoiding corrosion of surfaces or skin irritation. Mild ingredients (such as alkyl glycosides and carbon dot surfactants) are used, combined with the low toxicity of D-limonene, to ensure safe use and suitability for various scenarios.

[0030] In this invention application, firstly, the oil stain cleaner achieves highly efficient removal of heavy oil stains by using mild carbon-dot surfactants and alkyl glycosides, combined with the strong dissolving power of D-limonene, while maintaining mildness to avoid corrosion or irritation to the cleaned surface or user. The pH value is controlled within the range of 7-9 to ensure its mild properties. At the same time, the use of bio-based surfactants (such as alkyl glycosides) and natural solvents (such as D-limonene) reduces environmental pollution. While maintaining high cleaning efficiency, the cost is controlled, making it competitive in the market and achieving a win-win situation of environmental protection and economy. In addition, the high adsorption capacity of carbon-dot surfactants stabilizes dispersed oil particles, improves anti-redeposition performance, and ensures long-lasting cleaning effect. Through the combination of various surfactants and additives, the oil stain cleaner can effectively remove different types of oil stains (such as mineral oil, vegetable oil, and animal oil), providing an efficient, mild, environmentally friendly, and multi-purpose cleaning solution.

[0031] Preferably, the carbon dots of the carbon dot surfactant appear spherical in a transmission electron microscope, with a particle size ranging from 1 to 5 nm.

[0032] In this invention application, the high specific surface area and strong adsorption capacity of carbon dot surfactants significantly improve the removal efficiency of heavy oil stains. Their nanoscale size allows them to penetrate tiny crevices and thoroughly clean areas that are difficult for traditional surfactants to reach. Carbon dot surfactants are prepared from renewable biomass, have good biodegradability, and have little environmental impact after use, reducing the pollution caused by traditional chemical surfactants and conforming to the trend of green chemistry. Carbon dot surfactants have low toxicity and a pH value controlled within a mild range of 7-9, avoiding corrosion or irritation to the cleaned surface and the user's skin, thus improving safety. The raw materials for the preparation of carbon dot surfactants are inexpensive and the dosage is small (0.1-0.35 wt%), effectively controlling production costs. While effectively removing stains, it also reduces the amount of cleaning agent used, improving economic efficiency.

[0033] Preferably, the anionic surfactant comprises one or more of the following: sodium alkyl sulfonate, α-olefin sulfonate, alkyl glycerol ether sulfonate, and fatty alcohol sulfate salt; and / or, other nonionic surfactants comprise one or more of the following: fatty alcohol polyoxyethylene ether, PPG2 butanol polyether, dodecyl dimethylamine oxide, and fatty acid methyl ester ethoxylate; and / or, the detergent builder comprises one or more of the following: disodium EDTA, sodium gluconate, and sodium citrate; and / or, the buffer stabilizer comprises one or more of the following: sodium dihydrogen phosphate, sodium bicarbonate, sodium carbonate, and sodium silicate.

[0034] In some embodiments, the anionic surfactants include: sodium alkyl sulfonates (e.g., sodium octyl sulfonate, which have strong detergency and are resistant to hard water); α-olefin sulfonates (e.g., sodium α-olefin sulfonate, which have good foaming properties and are suitable for emulsification); alkyl glycerol ether sulfonates (which are mild, resistant to hard water, and enhance dispersion); and fatty alcohol sulfates (e.g., sodium lauryl sulfate, which have rich foaming properties and strong detergency). The proportion of anionic surfactants is 1-3 wt%, providing the main detergency agent, and their performance is optimized when combined with nonionic surfactants.

[0035] In some embodiments, other nonionic surfactants include: fatty alcohol polyoxyethylene ethers (e.g., AEO-9, which have strong emulsifying power and are suitable for various oil stains); PPG-2-butanol polyethers (which enhance wetting and are suitable for cleaning hard surfaces); dodecyl dimethyl amine oxide (which has amphoteric properties, foaming and thickening properties, and is mild); and fatty acid methyl ester ethoxylates (which are environmentally friendly, have strong detergency, and are suitable for heavy oil stains). The proportion of other nonionic surfactants is 2-4 wt%, which optimizes emulsification, dispersion, and wetting properties, adapts to different types of oil stains, and improves formulation diversity and adaptability.

[0036] In some embodiments, the buffer stabilizers are: sodium dihydrogen phosphate: mild buffer, suitable for neutral pH; sodium bicarbonate: weakly alkaline, stabilizes pH, enhances detergency; sodium carbonate: aids in washing, breaks down grease; sodium silicate: prevents corrosion, protects metal surfaces. The appropriate proportion of buffer stabilizers maintains pH 7-9, ensuring the formula is mild and stable, and avoiding the impact of acid-base fluctuations on performance.

[0037] In some embodiments, the builders are: disodium EDTA: strong chelation, preventing hard water precipitation; sodium gluconate: mild, environmentally friendly, preventing redeposition; sodium citrate: weakly acidic buffer, aiding in stain removal. The optimized builder ratio enhances resistance to hard water and prevents redeposition.

[0038] In some embodiments, deionized water serves as a solvent to ensure the uniformity and environmental friendliness of water-based formulations.

[0039] In this invention application, the synergistic effect of anionic and nonionic surfactants significantly enhances the removal ability of various dirt (such as grease), buffer stabilizers effectively maintain pH value, prevent component degradation, and extend product shelf life, detergent builders reduce the interference of hard water on washing effect by chelating metal ions, enhance the adaptability of the formula under different water quality conditions, and the addition of nonionic surfactants reduces irritation to skin and fabrics, making it suitable for household and personal care products. By optimizing the component ratio, production costs can be reduced while ensuring performance, making it suitable for large-scale industrial applications.

[0040] Oil stain cleaning agent preparation method Secondly, such as Figure 1 As shown, a method for preparing an oil stain cleaning agent, comprising preparing any of the oil stain cleaning agents described in the first aspect, including: Step S100: Prepare carbon dot surfactant, obtain isomeric octane polyoxyethylene polyoxypropylene ether, mix isomeric octane polyoxyethylene polyoxypropylene ether and carbon dot surfactant, then add alkyl glycoside to form a mixture, and sonicate the mixture under the following conditions: frequency 40-100kHz, power 3.0-10.0kW, time 10-60 minutes. Step S200: After ultrasonic treatment, add D-limonene, anionic surfactant, other nonionic surfactant, buffer stabilizer, detergent aid and deionized water to the mixture, stir to make the mixed solution uniform, and adjust the pH value of the mixed solution system to 7-9. Step S300: Sample and test the pH value, surface tension, and detergency of the product. After confirming that it meets the requirements, the finished oil stain cleaning agent is obtained.

[0041] In some embodiments, in step S100, the mixture is treated with an ultrasonic generator. By adjusting the frequency, power, and time, the components are ensured to be fully dispersed. For example, the ultrasonic conditions are: frequency, for example, 40 kHz, 50 kHz, 60 kHz, 70 kHz, 80 kHz, 90 kHz, 100 kHz; power, for example, 3.0 kW, 4.0 kW, 5.0 kW, 6.0 kW, 7.0 kW, 8.0 kW, 9.0 kW, 10.0 kW; and time, for example, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes. The ultrasonic treatment makes the carbon dots, CA, and APG uniformly dispersed, forming a stable mixture, laying the foundation for the subsequent addition of components.

[0042] In some embodiments, in step S100, ultrasonic treatment generates ultrasonic cavitation effect to generate microbubbles, which disperses carbon dots. Under the ultrasonic-induced shear force and shock wave, the negative charge of the carbon dots accelerates the formation of a stable mixed micelle system of carbon dots, isomeric octane polyoxyethylene polyoxypropylene ether, and alkyl glycosides, reducing the water-oil interfacial tension and enabling the carbon dots to be used to adsorb and capture oil stains. The hydrophobic segment of the isomeric octane polyoxyethylene polyoxypropylene ether includes PPO segments and isomeric octane groups. The hydrophobic segment of the isomeric octane polyoxyethylene polyoxypropylene ether is combined with the hydrophobic region of the carbon dots through hydrophobic interaction.

[0043] In some embodiments, in step S200, each component can be accurately weighed according to a certain formula ratio and gradually added to the mixture. Rapid pouring should be avoided to ensure uniform mixing. The stirring process is carried out at room temperature, and the stirring speed and time are adjusted according to the equipment specifications. It usually continues until the solution has no obvious layering or precipitation, forming a uniform and stable cleaning agent solution. The pH value is controlled at 7-9 to ensure that the system is mild and suitable for various cleaning scenarios.

[0044] In some embodiments, in step S300, precision instruments (such as pH meters and surface tension meters) can be used for testing. The detergency test can be carried out under laboratory conditions, using standard oil stain samples and cleaning procedures, and the removal rate is recorded to ensure that the finished cleaning agent has a stable pH value, low surface tension and high detergency to meet household or industrial cleaning needs.

[0045] In the oil stain cleaning agent preparation method of this invention application, firstly, the high specific surface area and nano-characteristics of carbon point surfactants significantly enhance the penetration and dispersion ability of oil stains. Combined with the synergistic effect of anionic and nonionic surfactants, it improves the removal efficiency of various greases, proteins and complex dirt. The addition of D-limonene enhances the dissolution effect on stubborn oil stains, making the cleaning agent suitable for various scenarios such as industrial and household use. In addition, stepwise mixing and precise pH control (7-9) ensure the uniform dispersion and chemical stability of each component. The buffer stabilizer effectively prevents pH drift. The detergent aid reduces hard water interference by chelating metal ions, extending the product's shelf life and maintaining long-term use effect. The use of green surfactants such as alkyl glycosides and D-limonene reduces the product's environmental impact. The mildness of nonionic surfactants reduces irritation to the skin and the cleaned surface. Furthermore, the stepwise addition and stirring process is simple and easy to control, suitable for industrial production. Accurate proportioning and post-processing steps (such as filtration and testing) ensure consistent product quality, while optimizing raw material utilization and reducing production costs.

[0046] Preferably, in step S100, vegetable oil and hydrogen peroxide are uniformly mixed in N,N-dimethylformamide to form a homogeneous solution, and pyrolyzed at 180°C for 4-8 hours. After the reaction is completed, the mixture is cooled to room temperature, the crude product is collected, and then purified by dialysis. The resulting solution is then subjected to rotary evaporation to obtain a carbon dot surfactant.

[0047] In some embodiments, vegetable oil (e.g., rich in fatty acids or triglycerides) is uniformly mixed with hydrogen peroxide (an oxidant) in N,N-dimethylformamide (DMF) to form a homogeneous solution. DMF, as a polar aprotic solvent, possesses excellent solubility and high-temperature stability, effectively dissolving both vegetable oil and hydrogen peroxide and promoting uniform contact between reactant molecules. Hydrogen peroxide provides reactive oxygen species, initially oxidizing unsaturated bonds or aliphatic chains in the vegetable oil, laying the foundation for the subsequent pyrolysis reaction to generate carbon dot structures.

[0048] In some embodiments, at a high temperature of 180°C, vegetable oil molecules undergo pyrolysis, carbonization, and condensation reactions under the oxidation of hydrogen peroxide, forming nanoscale carbon dots. During pyrolysis, fatty acid chains break and recombine, generating carbon dot structures with carbon skeletons and surface functional groups (such as hydroxyl, carboxyl, and amino groups). DMF, as a reaction medium, not only stabilizes the reaction system but may also enhance the surface activity of carbon dots by participating in the formation of surface functional groups through its nitrogen atoms. The reaction time (4-8 hours) controls the particle size and surface properties of the carbon dots; too short a time may lead to incomplete carbon dot formation, while too long a time may cause over-carbonization and reduce surface activity.

[0049] In some embodiments, after the reaction is complete, the system is cooled to room temperature to terminate the pyrolysis reaction and stabilize the resulting carbon dot structure. The crude product contains carbon dots, byproducts (such as low molecular weight organic compounds), and residual solvent, requiring further purification to separate the target carbon dots.

[0050] In some embodiments, dialysis, for example, to remove small molecule impurities (such as unreacted vegetable oil fragments, DMF residues, and low molecular weight byproducts) from the crude product, is employed. The dialysis membrane is selected to retain carbon dots with a particle size of 1-10 nm, preferably 1-5 nm, while excluding substances with a molecular weight below 1000 Da, thereby improving the purity and uniformity of the carbon dots.

[0051] In some embodiments, the dialyzed solution is concentrated by rotary evaporation to remove solvent and water, yielding a high-purity carbon dot surfactant. Rotary evaporation is performed under low-temperature and reduced-pressure conditions to avoid damage to the functional groups on the carbon dot surface from high temperatures, thus ensuring its surface activity and the integrity of its nanostructure.

[0052] In this invention application, the carbon dot surfactant has a moderate particle size, enhancing its surface activity in oil stain cleaners. Its nano-size and abundant surface functional groups (such as hydroxyl and carboxyl groups) effectively reduce liquid surface tension, promote oil stain dispersion and emulsification, and improve cleaning efficiency. Dialysis purification and rotary evaporation processes ensure the high purity and uniformity of the carbon dots, preventing impurities from interfering with their dispersibility in the cleaning agent system. The nanostructure and hydrophilic surface functional groups of the carbon dots give them good dispersion stability in the aqueous phase, making them suitable for synergistic effects with anionic and nonionic surfactants to form stable microemulsion systems. Using vegetable oil as a raw material ensures renewable availability, and the preparation process avoids the use of heavy metals or toxic chemicals, conforming to green chemistry principles. Hydrogen peroxide is used as an oxidant, decomposing into water and oxygen, reducing environmental pollution. The resulting carbon dot surfactant exhibits good biocompatibility, suitable for both household and industrial cleaning applications. By controlling the pyrolysis time (4-8 hours) and the dialysis molecular weight cutoff (e.g., 1000 Da), the particle size and surface properties of the carbon dots are regulated, ensuring they meet the performance requirements of oil stain cleaners for nano-surfactants within a set range. The larger specific surface area further enhances its ability to adsorb and catalyze the decomposition of oil stains; the preparation process uses conventional equipment (such as reaction kettles, dialysis devices, and rotary evaporators), the process flow is clear, it is easy to scale up production, vegetable oil and hydrogen peroxide are inexpensive, and DMF can be recycled and reused, reducing production costs and making it suitable for industrial applications.

[0053] Methods for cleaning oil stains on hard surfaces Thirdly, such as Figure 2 As shown, a method for cleaning oil stains on hard surfaces, using any of the oil stain cleaning agents described in the first aspect or employing any of the oil stain cleaning agent preparation methods in the second aspect, includes: Step S10: Apply the oil stain cleaner to the hard surface oil stain; Step S20: Leave at room temperature for 20-30 seconds to wipe and clean the oil stains on the hard surface.

[0054] In some embodiments, in step S10, the oil stain cleaner evenly covers the oily area of ​​the hard surface by application, ensuring that the active components of the cleaner are in full contact with the oil. The carbon-dot surfactants in the cleaner (e.g., particle size 1-10 nm, specific surface area >1000 m² / g) can quickly penetrate the oil layer due to their nanoscale size and high specific surface area, reducing the adhesion between the oil and the hard surface. Anionic surfactants (such as sodium alkyl sulfonate and fatty alcohol sulfate salts) form micelles through their hydrophilic and lipophilic structures, encapsulating and dispersing oil molecules. Nonionic surfactants (such as fatty alcohol polyoxyethylene ethers and alkyl glycosides) enhance the emulsification ability of grease and improve the stability of the cleaner in hard water. D-limonene, as a natural solvent, further dissolves stubborn oil stains and, in conjunction with a builder (such as disodium EDTA), chelates metal ions, preventing the formation of insoluble complexes between the oil and the surface. The mild environment of pH range 7-9 ensures the safety of the cleaner on hard surfaces while optimizing the detergency of the surfactants.

[0055] In some embodiments, in step S20, the cleaning agent acts at room temperature for 20-30 seconds, or possibly between 20 and 300 seconds, sufficient for the active components to penetrate, emulsify, and disperse the oil. The efficient penetration and dissolving effects of carbon-dot surfactants and D-limonene accelerate the removal of oil from hard surfaces. The micellar structure formed by anionic and nonionic surfactants stably encapsulates oil molecules, preventing their redeposition. The wiping process further peels away the emulsified oil through mechanical force, combined with the chemical action of the cleaning agent, achieving efficient removal. Buffer stabilizers (such as sodium carbonate and sodium dihydrogen phosphate) maintain the pH stability of the system, ensuring the continuous action of the active components during cleaning, while protecting hard surfaces from acid and alkali corrosion.

[0056] In this invention application, firstly, the nano-characteristics and high specific surface area of ​​carbon dot surfactants, combined with the synergistic effect of anionic and nonionic surfactants, significantly enhance the penetration, emulsification, and dispersion capabilities of hard surface oil stains (including grease, protein, and complex dirt). The dissolving effect of D-limonene further enhances the removal effect on stubborn oil stains, enabling the cleaning process to be completed within 20-30 seconds. It is suitable for various hard surfaces such as metals, ceramics, glass, and plastics, requiring no heating or prolonged immersion, simplifying the operation process and improving cleaning efficiency. Furthermore, the simple application and wiping steps are suitable for industrial and household scenarios, lowering the barrier to entry. The raw materials are renewable, resulting in a low environmental impact. The cleaning process does not require high temperatures or strong acids / alkalis, reducing energy consumption and wastewater treatment costs, meeting the requirements of green chemistry and sustainable development. This achieves efficient, rapid, gentle, and environmentally friendly oil stain removal, demonstrating significant technological advantages and broad application prospects.

[0057] Preferably, in step S10, the oil stain cleaner is applied directly during use; or, it is applied after being diluted with water at a volume ratio of 1:1 to 1:10. In some embodiments, the cleaning agent can be diluted with water (typically deionized water or tap water) at a volume ratio of 1:1 to 1:10 before application to reduce the concentration of active ingredients, making it suitable for light to moderate oil stains or large-area cleaning scenarios. Even after dilution, the surfactants in the cleaning agent can still form effective micelles, and the nano-properties of the carbon dot surfactants ensure excellent penetration and dispersion capabilities even at lower concentrations. The mildness of the nonionic surfactants and the dissolving effect of D-limonene remain effective in the diluted system, synergistically maintaining the detergency and pH stability of the system with the help of the builders and buffer stabilizers. The dilution process increases the fluidity of the cleaning agent, facilitating uniform coverage of large surfaces while reducing the amount of active ingredients used and lowering cleaning costs. The addition of water improves the cleaning agent's adaptability in hard water environments, and the builders further reduce interference from calcium and magnesium ions through chelation.

[0058] In this invention application, the direct application method, due to its high concentration of active ingredients, can quickly penetrate and decompose stubborn oil stains, making it suitable for heavy oil stain scenarios, such as grease deposits on industrial equipment. Diluted application (1:1 to 1:10 volume ratio) is suitable for light to moderate oil stains or large-area cleaning, such as household kitchen surfaces or glassware, meeting diverse cleaning needs. The diluted application method, by adjusting the dilution ratio to 1:1 to 1:10, significantly reduces the amount of cleaning agent used, lowering usage costs, and is especially suitable for large-area or frequent cleaning scenarios. Direct application provides an efficient solution for localized heavy stains, avoiding the dilution step and simplifying the operation process. Both direct and diluted application are achieved through simple smearing or spraying, making them convenient to operate and suitable for both industrial and household scenarios.

[0059] Preferably, the hard surface includes a metal, ceramic, glass, or plastic surface; and / or, wiping and cleaning are performed using a cleaning cloth or brush followed by rinsing with water.

[0060] In some embodiments, the hard surface cleaning method involves hard surfaces including metal, ceramic, glass, or plastic surfaces, and wiping cleaning can be performed using a cleaning cloth or brush followed by rinsing with water. Wiping cleaning removes oil through a combination of mechanical and chemical action. Cleaning cloths (such as microfiber cloths), due to their high oil absorption and softness, adsorb and strip oil molecules after the cleaning agent emulsifies the oil, making them suitable for smooth surfaces (such as glass and ceramics). Brushes (soft or hard bristles) provide stronger mechanical friction, suitable for more stubborn oil stains on metal or plastic surfaces, enhancing the penetration and dispersion of the cleaning agent. Water rinsing (atmospheric or high-pressure water flow) uses the impact of water to further remove emulsified oil residue, especially suitable for hard surfaces with large areas or complex structures. Surfactants and D-limonene in the cleaning agent continue to play an emulsifying and dissolving role during wiping and rinsing, preventing oil redeposition. Buffer stabilizers (such as sodium carbonate) maintain the pH stability of the system, ensuring the activity of the cleaning agent during the mechanical cleaning process.

[0061] In this invention application, the cleaning method is applicable to various hard surfaces such as metals, ceramics, glass, and plastics, covering multiple application scenarios including industrial (e.g., mechanical parts), household (e.g., kitchenware, windows), and commercial (e.g., ceramic floors). The cleaning cloth is suitable for small areas or fine cleaning, the brush is suitable for stubborn stains, and water rinsing is convenient for large areas or complex surface treatments. The combination of multiple cleaning methods meets the needs of different scenarios. It is simple to operate, requiring no professional equipment or high-temperature conditions, lowering the barrier to entry and making it suitable for both industrial and household environments.

[0062] Examples and Comparative Examples Unless otherwise specified, the raw materials or reagents used in the following experiments of this invention are all commercially available products or reagents prepared according to conventional methods. Unless otherwise specified, the methods used in the experiments are all conventional experimental methods. Unless otherwise specified, the instruments used in the experiments are all commercially available.

[0063] The preparation of carbon dot surfactants includes: The preparation of carbon dot surfactants includes: uniformly mixing vegetable oil and hydrogen peroxide in N,N-dimethylformamide to form a homogeneous solution, pyrolyzing at 180°C for 4-8 hours; after the reaction is completed, cooling to room temperature, collecting the crude product, and then purifying it by dialysis. The resulting solution is then subjected to rotary evaporation to obtain the carbon dot surfactant.

[0064] Example 1 (Carbon Dots + CA + APG + Ultrasound) Step S1001: Obtain 0.2 wt% of the carbon dot surfactant prepared above, obtain 2.0 wt% of isomeric octane polyoxyethylene polyoxypropylene ether, mix the isomeric octane polyoxyethylene polyoxypropylene ether and the carbon dot surfactant, then add 1 wt% alkyl glycoside to form a mixture, and sonicate the mixture under the following conditions: frequency 50 kHz, power 5.0 kW, 30 minutes. Step S1002: After ultrasonic treatment, add 1.0 wt% D limonene, 1 wt% sodium octyl sulfonate, 2.5 wt% fatty alcohol polyoxyethylene ether, 0.5 wt% sodium bicarbonate, and 1.5 wt% sodium gluconate to the mixture, with the remainder being deionized water. Stir to make the mixed solution uniform, with a pH value of 8.4. Example 2 (Carbon Dots + CA + APG) Step S2001: Obtain 0.2 wt% of the carbon dot surfactant prepared above, obtain 2.0 wt% of isomeric octane polyoxyethylene polyoxypropylene ether, mix the isomeric octane polyoxyethylene polyoxypropylene ether and the carbon dot surfactant, and then add 1 wt% alkyl glycoside to form a mixture. Step S2002: Add 1.0 wt% D-limonene, 1 wt% sodium octyl sulfonate, 2.5 wt% fatty alcohol polyoxyethylene ether, 0.5 wt% sodium bicarbonate, and 1.5 wt% sodium gluconate to the mixture, with the remainder being deionized water. Stir to make the mixed solution homogeneous, with a pH value of 8.2.

[0065] Example 3 (CA+APG+Ultrasound) Step S3001: Obtain 2.0 wt% of isomeric octane polyoxyethylene polyoxypropylene ether, add 1 wt% alkyl glycoside to the isomeric octane polyoxyethylene polyoxypropylene ether to form a mixture, and sonicate the mixture under the following conditions: frequency 50 kHz, power 5.0 kW, 30 minutes. Step S3002: After ultrasonic treatment, add 1.0 wt% D-limonene, 1 wt% sodium octyl sulfonate, 2.5 wt% fatty alcohol polyoxyethylene ether, 0.5 wt% sodium bicarbonate, and 1.5 wt% sodium gluconate to the mixture, with the remainder being deionized water. Stir to make the mixed solution uniform, with a pH value of 7.0.

[0066] Example 4 (CA + Ultrasound) Step S4001: Obtain 2.0 wt% of isomeric octane polyoxyethylene polyoxypropylene ether and ultrasonically treat it under the following conditions: frequency 50 kHz, power 5.0 kW, 30 minutes. Step S4002: After ultrasonic treatment, add 1.0 wt% D-limonene, 1 wt% sodium octyl sulfonate, 2.5 wt% fatty alcohol polyoxyethylene ether, 0.5 wt% sodium bicarbonate, and 1.5 wt% sodium gluconate to the mixture, with the remainder being deionized water. Stir to make the mixed solution uniform, with a pH value of 7.2.

[0067] Example 5 (APG + Ultrasound) Step S5001: Obtain a 1 wt% alkyl glycoside mixture and sonicate it under the following conditions: frequency 50 kHz, power 5.0 kW, 30 minutes. Step S5002: After ultrasonic treatment, add 1.0 wt% D-limonene, 1 wt% sodium octyl sulfonate, 2.5 wt% fatty alcohol polyoxyethylene ether, 0.5 wt% sodium bicarbonate, and 1.5 wt% sodium gluconate to the mixture, with the remainder being deionized water. Stir to make the mixed solution uniform, with a pH value of 7.1.

[0068] Comparative Example 1 The commercially available Vegetable and Fruit Garden Sunshine Orange Oil Stain Remover, produced by Dongguan Jianwen Detergent Products Co., Ltd., contains: natural orange oil enzymes, alkyl glycosides, citric acid, sodium bicarbonate, shell powder, tetrasodium EDTA, preservatives, fragrance, and the remainder is water.

[0069] Comparative Example 2 The commercially available Mr. Muscle Kitchen Degreaser, manufactured by Shanghai Johnson Pharmaceutical Co., Ltd., contains: sodium carbonate, linear alkylbenzene sulfonic acid, diethylene glycol butyl ether, preservatives, fragrance, and the balance being water.

[0070] Comparative Example 3 The commercially available "Big Rooster Steward" multi-purpose oil stain remover produced by Relkemi Ltd. includes: cetyltrimethylammonium bromide (CTAB), fatty alcohol polyoxyethylene ether, limonene, sodium hydroxide, ethylene glycol butyl ether, citronellol, geraniol, benzyl alcohol, cocamidopropyl betaine, and the balance being water.

[0071] It should be noted that this invention application may also include all embodiments corresponding to the endpoint values ​​of all components, the endpoint values ​​of ultrasonic treatment, and the intermediate values ​​mentioned above. The weight percentage (wt%) of each component in all embodiments can be determined by the final oil stain cleaning agent components and pH range, and its weight value or number of parts can be calculated. This invention application will not be elaborated upon in comparison.

[0072] Tests: Volatile Organic Compounds (VOCs), Total Intake (TIC) Peak Area, and Detergent Power Determination of volatile organic compounds (VOCs): such as... Figure 3As shown, the device for detecting volatile organic compounds (VOCs) in oil stain cleaning agents includes: an air sampler, a sample cell, and a handheld gas detector. The air sampler is connected to the sample cell via a gas pipeline, and the sample cell is connected to the handheld gas detector via a pipeline. Before testing, a blank test is performed using air. Air is introduced through the air sampler, while the sample cell contains only pure water to obtain the background value of VOCs. This background value needs to be subtracted later. Air is then introduced through the air sampler into the sample cell containing the oil stain cleaning agent. The air carrying the VOCs from the oil stain cleaning agent enters the handheld gas detector, which detects the VOCs value of the oil stain cleaning agent sample.

[0073] TIC total peak area determination: can be determined by GCMS (Gas Chromatography Mass Spectrometry) technology, as follows: (1) Sample pretreatment. Liquid-liquid extraction (LLE): take 10-50 mL of sample, add 10 mL of dichloromethane, shake for 5 min; add 2-5 g of NaCl, enhance phase separation, let stand for layering; collect the organic phase, dry with Na2SO4, concentrate to 1 mL, filter, add internal standard (such as d8-toluene 10 µg / mL); headspace injection: take 5 mL of sample and place it in a 20 mL headspace vial, heat (60-80°C, 20 min), after equilibration, take gas phase for injection; dilution: if the sample concentration is high, directly dilute with methanol or hexane 40-100 times, add internal standard, filter and then inject; blank sample: repeat pretreatment with pure solvent or water to confirm no contamination; (2) Instrument settings. Gas chromatography (GC) settings: Injector: 250°C, Mode: Split injection (split ratio 10:1 or 50:1) or splitless injection (high sensitivity), Injection volume: 1-2 μL, Column: DB-5MS (30m × 0.25mm × 0.25μm), Carrier gas: Helium, constant flow 1.0 mL / min; Temperature program: Initial temperature: 40°C, hold for 2 min, ramp to 150°C at 10°C / min, hold for 1 min, ramp to 280°C at 5°C / min, hold for 5 min, Total run time: Approximately 30 min, Transfer line temperature: 280°C; Mass spectrometry (MS) settings: Ion source: EI, 70 eV, Temperature: 230°C, Mass analyzer: Full Scanning mode, m / z 35-500, qualitative analysis, solvent delay: 3-5 min, avoid solvent peak interference, use PFTBA to calibrate the mass axis, and ensure that the deviation of m / z 69, 219, 502 is <0.5u; (3) Data acquisition: the software records the total ion chromatogram (TIC) and the mass spectrum of each retention time. The horizontal axis of TIC is the retention time (time / s), and the vertical axis is the ion intensity; (4) Data processing: peak identification: the software (such as MassHunter) automatically integrates each peak in TIC, and manually checks to ensure that there are no missing peaks or misidentification; remove baseline noise and solvent peaks (RT < solvent delay time), sum the areas of all detected peaks to obtain the total ion signal intensity. The above content can also be performed using standard operation.

[0074] Determination of detergency: Refer to the operation of national standard GBT358332018. The specific method is as follows: (1) Preparation of artificial dirt. Formula: 64.0g soybean oil, 8.0g ammonia-free caramel coloring, 12.0g wheat flour, 8.0g lard, 8.0g tallow, 2.4g glyceryl monostearate. Weigh soybean oil, tallow, lard and glyceryl monostearate in a 250mL plastic beaker, heat to 70℃ in a water bath to dissolve; while stirring, cool to 30℃, add ammonia-free caramel coloring, stir at a speed of not less than 1000r / min for 30min, emulsify evenly, add wheat flour, stir for another 10min, age for 24h, store in the refrigerator for later use, restore to 20℃~25℃ when using. Note 1: The shelf life of artificial dirt in the refrigerator is set at half a month. Note 2: The detergency test results of some actual samples may change as the dirt storage period is extended. Therefore, the test results are marked with the dirt preparation and usage dates for traceability. (2) Dirt preparation. 1Cr18Ni9Ti brushed stainless steel (50mm×50mm×3mm) was selected as the test specimen. The specimen was washed, dried in an oven at 120°C for 1h, cooled to room temperature, and weighed on an analytical balance and recorded as M. Oil stains were evenly applied to the specified parts of the specimen with a brush. The dirt mass was controlled at 20-100mg / piece. After application, the specimen was dried in an oven at 150°C for 15min. After cooling, it was placed in a UV constant temperature aging chamber and irradiated at 45°C for 1h. After the end, the specimen was taken out, dried and aged in a desiccator for 10h, weighed, and recorded as M1. Clamp the prepared test strips on the washing rack of the washing machine, use a stopwatch to time, and immerse the oily part completely in the carbon point solution (5mg / mL) for 10min, wash for 10min, and then wash in clean water for 1min. Remove the test strips, dry them in an oven at 120°C for 30min, cool them to room temperature, weigh them, and record the weight as M2. Use 3 test strips for each sample and measure them in parallel three times; (3) Calculation of detergency (index). Detergency is the efficiency of washing away oil stains, expressed as % and the calculation formula is: In the formula: M is the mass of the test piece, in grams (g); M1 is the mass of the soiled piece before washing, in grams (g); M2 is the mass of the soiled piece after washing, in grams (g). Under repeated conditions, the absolute difference between two measurements should ideally not exceed 3%, and the arithmetic mean of the measurement data should be taken as the detergency result.

[0075] The total TIC peak area of ​​the oil stain cleaning agents of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 was measured. The total TIC peak areas of the oil stain cleaning agents of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 are as follows: sample TIC total peak area Example 1 <![CDATA[1.7×10 10 ]]> Comparative Example 1 <![CDATA[2.0×10 10 ]]> Comparative Example 2 <![CDATA[1.5×10 10 <!-- 12 -->]]> Comparative Example 3 <![CDATA[1.4×10 11 ]]> The volatile organic compound (VOC) values ​​and detergency of the oil stain cleaners from Examples 1, 2, 3, 4, 5, Comparative Examples 1, 2, and 3 were tested. The VOC values ​​(VOCs) and detergency of the oil stain cleaners from Examples 1, 2, 3, 4, 5, Comparative Examples 1, 2, and 3 are as follows (due to handheld testing, the following VOC values ​​may have an error adjustment range of -20% to 20%): sample VOCs / ppm Cleaning power Example 1 22 93.56% Example 2 23 60.07% Example 3 24 80.36% Example 4 25 70.46% Example 5 25 69.88% Comparative Example 1 20 87.36% Comparative Example 2 15 59.01% Comparative Example 3 140 89.22% (1) Analysis of the reasons for the total peak area of ​​TIC 1) Total peak area results of TIC The total peak area of ​​TIC ranges from 1.5 × 10¹ 0 The difference between Comparative Example 2 and Comparative Example 3 is significant, spanning an order of magnitude. The total TIC peak area of ​​Comparative Example 3 (1.4 × 10¹¹) is much larger than that of the other samples, approximately equal to that of Example 1 (1.7 × 10¹¹). 0 Comparative Example 1 (2.0 × 10¹) 0 ) and Comparative Example 2 (1.5 × 10¹ 0 The total TIC peak area of ​​Example 1, Comparative Example 1, and Comparative Example 2 is 7-9 times that of the previous example, and is close to 10¹. 0 The magnitude indicates a low content of volatile components.

[0076] 2) Analysis of the reasons for the total peak area of ​​TIC Example 1: The total TIC peak area was mainly contributed by D-limonene (1 wt%), which produced a strong ionic signal in GC-MS. Other components, such as carbon dot surfactants, alkyl glycosides, and fatty alcohol polyoxyethylene ethers, contributed little to the TIC due to their high molecular weight or low volatility. The moderate TIC value indicates that Example 1 maintained the stability of the formulation while containing a small amount of volatile components.

[0077] Comparative Example 1: Natural orange oil enzyme may contain volatile terpenoids, which produce certain ion signals, but their concentration is low, and other components (such as sodium bicarbonate and shell powder) are not volatile, resulting in a slightly lower total TIC peak area than in Example 1.

[0078] Comparative Example 2: Due to the low volatility of diethylene glycol butyl ether and the fact that components such as linear alkylbenzene sulfonic acid and sodium carbonate are difficult to volatilize or ionize under GC-MS conditions, the low TIC value reflects that its volatile component content is the lowest, which may affect the detergency performance due to the lack of efficient solvents (such as D-limonene).

[0079] Comparative Example 3: The total peak area of ​​TIC was significantly higher than that of other samples, mainly because it contained a variety of volatile compounds (D-limonene, ethylene glycol butyl ether, citronellol, geraniol, benzyl alcohol, etc.). These substances generated a large number of ion signals in GC-MS. The complexity of the fragrance (citronellol, geraniol, etc.) further increased the TIC. Sodium hydroxide (strong alkaline) may promote the decomposition or release of volatile solvents, increasing the TIC.

[0080] (2) Analysis of the reasons for the volatile organic compound values 1) Volatile Organic Compounds Values The VOC values ​​ranged from 15 ppm (Comparative Example 2) to 140 ppm (Comparative Example 3), showing significant differences. The VOC values ​​of Examples 1-5 were between 20-30 ppm, which is at a moderately low level and has good environmental performance. Comparative Example 2 (15 ppm) and Comparative Example 1 (20 ppm) had the lowest VOC values, showing excellent environmental performance. Comparative Example 3 (140 ppm) had a VOC value much higher than other samples and had the worst environmental performance.

[0081] 2) Analysis of the causes of volatile organic compound (VOC) values Comparative Example 3 contains several highly volatile solvents (limonene, ethylene glycol butyl ether, citronellol, geraniol, and benzyl alcohol), which have high volatilization pressures and readily release VOCs. The fragrance components (citronellol, geraniol, etc.) further increase volatility, resulting in the highest total TIC peak area and VOC values ​​far exceeding those of other samples. The strong alkalinity of sodium hydroxide may promote the release of certain volatile components. Comparative Example 2 used only a single solvent (diethylene glycol butyl ether) in low amounts (lower than D limonene in Examples 1-5). Diethylene glycol butyl ether is less volatile than limonene, has a low fragrance content, and sodium carbonate and alkylbenzene sulfonic acid are non-volatile components.

[0082] Comparative Example 1 uses natural orange oil enzymes, which have lower volatility than limonene. APG, citric acid, sodium bicarbonate, and shell powder are low / non-volatile components, while fragrance and tetrasodium EDTA contribute a small amount of VOCs.

[0083] The VOC values ​​(22ppm-25ppm) of Examples 1-5 were mainly affected by the amount of D-limonene, the type of component, and the pH. The VOC values ​​were low and within an acceptable range.

[0084] (3) Analysis of the reasons for the detergency results 1) Detergent cleaning power results The detergency ranged from 59.01% (Comparative Example 2) to 93.56% (Example 1), with significant differences in cleaning effect. Example 1 (93.56%), Comparative Example 1 (87.36%), and Comparative Example 3 (89.22%) showed high detergency and were suitable for heavy oil stains. Example 2 (60.07%), Example 5 (69.88%), Example 4 (70.46%), and Comparative Example 2 (59.01%) showed low detergency and poor cleaning effect.

[0085] 2) Analysis of the reasons for poor detergency In this invention application, ultrasonic treatment plays a crucial role in the preparation of oil stain cleaning agents. It generates microbubbles through ultrasonic cavitation, and these microbubbles, upon collapse, produce high shear stress, shock waves, and localized high temperature and pressure, promoting molecular diffusion and uniform dispersion in the mixture. In surfactant systems, ultrasonic treatment can lower the critical micelle concentration (CMC), accelerate micelle formation, and enhance their stability, facilitating the dispersion of carbon dots, preventing aggregation, and improving interfacial activity. Ultrasound can also enhance the permeability and emulsifying ability of surfactants, reducing the hindrance of electrostatic repulsion to micelle formation, thereby improving overall detergency. Ultrasonic treatment conditions (e.g., frequency 40-100 kHz, power 3.0-10.0 kW, duration 10-60 minutes) allow for gentle operation, avoiding damage to component structures and meeting environmental protection requirements.

[0086] In this invention application, the synergy between carbon dots and CA, carbon dots and APG, and CA and APG is as follows: the negative charge of carbon dots leads to electrostatic repulsion, hindering their independent formation of micelles; CA, as a nonionic surfactant, is inserted into the micelles of carbon dots, reducing charge repulsion and lowering the energy barrier for micelle formation; the hydrophobic segments of CA (PPO segments and isomeric eight-carbon groups) combine with the hydrophobic regions of carbon dots through hydrophobic interactions, improving the internal stability of the micelles; the addition of CA reduces the surface charge density of carbon dot micelles, reducing electrostatic repulsion and improving emulsification efficiency; the nanoscale size of carbon dots provides more interfacial contact points, and their interaction with CA accelerates oil adsorption and separation. The mixture of APG and carbon dots forms a hybrid micelle. The nonionic properties of APG compensate for the electrostatic defects of carbon dots, improving micelle stability and emulsifying ability. The nanoscale size and high specific surface area of ​​carbon dots also enhance the synergistic effect with APG, accelerating the adsorption and dispersion of oil. Carbon dots capture oil through adsorption, while APG micelles maintain their dispersed state, jointly preventing redeposition. The permeability of CA combined with the emulsifying ability of APG allows the formulation to penetrate deep into the oil and disperse efficiently. Both are nonionic surfactants, forming a stable hybrid micelle that improves the cleaning effect on heavy oil stains. Its mild properties make it suitable for sensitive surfaces and skin contact scenarios.

[0087] In this invention application, the synergy between carbon dots and ultrasound, CA and ultrasound, and APG and ultrasound is as follows: the cavitation effect of ultrasound promotes the uniform dispersion of carbon dots, overcomes the aggregation problem caused by their electrostatic repulsion, and enhances the interfacial activity of nanoparticles; the negative charge of carbon dots, under the shear force and shock wave induced by ultrasound, reduces the water-oil interfacial tension, enhancing adsorption and emulsification; ultrasound enhances the permeability of CA, accelerating its penetration into the micropores of oil stains through shock waves; the micelle structure of CA is more stable under the action of ultrasound, promoting the formation of emulsions; ultrasound reduces the critical micelle concentration (CMC) of APG, accelerating micelle formation; the natural emulsifying ability of APG is enhanced in the dynamic environment of ultrasound, improving oil stain dispersion and preventing redeposition.

[0088] In this invention application, the cavitation effect of ultrasound assists in the assembly and dynamic optimization of a ternary system of carbon dots, CA, and APG. Ultrasound promotes the stable mixing of carbon dots, CA, and APG to construct a quaternary system, reducing electrostatic repulsion and accelerating the formation of mixed micelles. The ternary synergy of carbon dots, CA, and APG forms a highly efficient and stable mixed micelle system through electrostatic shielding, hydrophobic interactions, and nanoscale effects. The nano-adsorption capacity of carbon dots is amplified under ultrasound-induced shear force and shock wave, combining with the permeability of CA and the emulsifying effect of APG to form a more stable emulsion system. Ultrasound enhances the overall interfacial activity, reduces the water-oil interfacial tension, and promotes the rapid stripping and dispersion of oil stains through local high pressure. At the same time, carbon dots capture oil stains, and CA and APG prevent redeposition through micelle action. The quaternary synergy not only improves the decontamination efficiency but also improves the environmental friendliness (low VOC emissions). The biodegradability of APG, the mildness of CA, the biocompatibility of carbon dots, and the physical assistance of ultrasound work together to achieve efficient, safe, and sustainable cleaning results, reducing the amount of surfactant used.

[0089] In this invention application, the quaternary synergistic system enhances the detergency, anti-redeposition performance, environmental friendliness, and applicability of the cleaning agent. The dispersion of carbon dots, the penetration of CA, the emulsification of APG, and the physical assistance of ultrasound work synergistically to suit various types of oil stains. The non-ionic properties ensure gentleness, while the biocompatibility of carbon dots and the efficiency of ultrasound guarantee safety. The renewability of APG and the high efficiency of carbon dots reduce the amount of surfactant used, lower production costs, comply with strict environmental regulations, and are suitable for cleaning in various scenarios such as homes and industries.

[0090] Those skilled in the art will understand that the steps, measures, and schemes in the various operations, methods, and processes discussed in this application can be alternated, modified, combined, or deleted; furthermore, other steps, measures, and schemes in the various operations, methods, and processes discussed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted; furthermore, the steps, measures, and schemes in the prior art that are similar to those disclosed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above-described embodiments are merely illustrative of several implementation methods of this disclosure, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of the patent for the embodiments of this disclosure. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the embodiments of this disclosure, and these all fall within the protection scope of the embodiments of this disclosure. Therefore, the protection scope of the embodiments of this disclosure should be determined by the appended claims. As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes in form and detail can be made without departing from the spirit and scope of the present invention as defined in the appended claims.

[0091] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. An oil stain cleaner, characterized in that, include: Carbon dot surfactant 0.1-0.35 wt%; 1-3 wt% of isomeric octacarbon polyoxyethylene polyoxypropylene ether; Alkyl glycoside 1-2 wt%; D-Limonene 0.5-1.0 wt%; Anionic surfactant 1-3 wt%; Other nonionic surfactants 2-4 wt%; Buffer stabilizer 0.5-1.0 wt%; 1-3 wt% of detergent builder; The remainder is deionized water; The pH range is 7-9.

2. The oil stain cleaning agent according to claim 1, characterized in that, The carbon dots of carbon dot surfactants appear spherical in transmission electron microscopy, with a particle size ranging from 1 to 5 nm.

3. An oil stain cleaning agent according to claim 1 or 2, characterized in that, The anionic surfactant includes one or more of the following: sodium alkyl sulfonate, α-olefin sulfonate, alkyl glycerol ether sulfonate, and fatty alcohol sulfate salt; and / or, other nonionic surfactants include one or more of the following: fatty alcohol polyoxyethylene ether, PPG2 butanol polyether, dodecyl dimethylamine oxide, and fatty acid methyl ester ethoxylate; and / or, the detergent builder includes one or more of the following: disodium EDTA, sodium gluconate, and sodium citrate; and / or, the buffer stabilizer includes one or more of the following: sodium dihydrogen phosphate, sodium bicarbonate, sodium carbonate, and sodium silicate.

4. A method for preparing an oil stain cleaning agent, comprising preparing the oil stain cleaning agent according to any one of claims 1-3, characterized in that, include: Step S100: Prepare carbon dot surfactant, obtain isomeric octane polyoxyethylene polyoxypropylene ether, mix isomeric octane polyoxyethylene polyoxypropylene ether and carbon dot surfactant, then add alkyl glycoside to form a mixture, and sonicate the mixture under the following conditions: frequency 40-100kHz, power 3.0-10.0kW, 10-60 minutes. Step S200: After ultrasonic treatment, add D-limonene, anionic surfactant, other nonionic surfactant, buffer stabilizer, detergent aid and deionized water to the mixture, stir to make the mixed solution uniform, and adjust the pH value of the mixed solution system to 7-9. Step S300: Sample and test the pH value, surface tension, and detergency of the product. After confirming that it meets the requirements, the finished oil stain cleaning agent is obtained.

5. The method for preparing an oil stain cleaning agent according to claim 4, characterized in that, In step S100, the preparation of carbon dot surfactant includes: uniformly mixing vegetable oil and hydrogen peroxide in N,N-dimethylformamide to form a homogeneous solution, pyrolyzing at 180°C for 4-8 hours; after the reaction is completed, cooling to room temperature, collecting the crude product, purifying it by dialysis, and then rotary evaporating the resulting solution to obtain carbon dot surfactant.

6. The method for preparing an oil stain cleaning agent according to claim 5, characterized in that, In step S100, ultrasonic treatment generates ultrasonic cavitation effect to produce microbubbles, which disperses carbon dots. Under the ultrasonic-induced shear force and shock wave, the negative charge of the carbon dots accelerates the formation of a stable mixed micelle system of carbon dots, isomeric octane polyoxyethylene polyoxypropylene ether, and alkyl glycosides, reducing the water-oil interfacial tension. The hydrophobic segment of the isomeric octane polyoxyethylene polyoxypropylene ether includes PPO segments and isomeric octane groups. The hydrophobic segment of the isomeric octane polyoxyethylene polyoxypropylene ether combines with the hydrophobic region of the carbon dots through hydrophobic interaction.

7. The method for preparing an oil stain cleaning agent according to claim 6, characterized in that, The anionic surfactant includes one or more of the following: sodium alkyl sulfonate, α-olefin sulfonate, alkyl glycerol ether sulfonate, and fatty alcohol sulfate salt; and / or, other nonionic surfactants include one or more of the following: fatty alcohol polyoxyethylene ether, PPG2 butanol polyether, dodecyl dimethylamine oxide, and fatty acid methyl ester ethoxylate; and / or, the detergent builder includes one or more of the following: disodium EDTA, sodium gluconate, and sodium citrate; and / or, the buffer stabilizer includes one or more of the following: sodium dihydrogen phosphate, sodium bicarbonate, sodium carbonate, and sodium silicate.

8. A method for cleaning oil stains on hard surfaces, using the oil stain cleaning agent according to any one of claims 1-3 or the oil stain cleaning agent preparation method according to any one of claims 4-7, characterized in that, include: Step S10: Apply the oil stain cleaner to the hard surface oil stain; Step S20: Leave at room temperature for 20-30 seconds to wipe and clean the oil stains on the hard surface.

9. A method for cleaning oil stains on hard surfaces according to claim 8, characterized in that, In step S10, the oil stain cleaning agent is applied directly during use; Alternatively, dilute with water at a volume ratio of 1:1 to 1:10 before application.

10. A method for cleaning oil stains on hard surfaces according to claim 9, characterized in that, The hard surface includes a metal, ceramic, glass, or plastic surface; and / or, wiping and cleaning with a cleaning cloth or brush followed by rinsing with water.

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