Highly soluble and stable silicon-based reverse microemulsion, preparation method and application thereof

Abstract

The application discloses a preparation method of high-solubilization and high-stability silicon-based reverse microemulsion, and specifically comprises the following steps: step 1, preparing a compound surfactant; step 2, adding decamethylcyclopentasiloxane oil phase into the compound surfactant prepared in step 1, and ultrasonically treating at room temperature to fully mix and uniformly distribute the system; and step 3, under the condition of continuous ultrasonic treatment, adding deionized water into the mixed system in step 2 in a drop-by-drop mode, and continuously ultrasonically treating until the system presents a transparent and uniform state, so that the silicon-based reverse microemulsion is prepared. The application further discloses the high-solubilization and high-stability silicon-based reverse microemulsion and application thereof; and the microemulsion prepared by the application has the characteristics of high solubility and high stability.

Description

Technical Field

[0001] This invention belongs to the field of fine chemical engineering and microemulsion preparation technology, and relates to highly solubilized and highly stable silicon-based reverse microemulsions. This invention also relates to the preparation method and application of highly solubilized and highly stable silicon-based reverse microemulsions. Background Technology

[0002] Reverse microemulsions are thermodynamically stable, homogeneous colloidal dispersions that spontaneously form from a continuous oil phase, an aqueous phase, surfactants, and co-surfactants in appropriate proportions. Their microstructure consists of nanoscale water cores (typically 10–100 nm) dispersed within the continuous oil phase. Reverse microemulsions possess characteristics such as extremely low interfacial tension, adjustable water core size, and good system stability. They can serve as nanoreactors to support water-soluble or oil-soluble reactants, showing broad application prospects in materials synthesis, textile auxiliaries, biomedicine, and catalytic reactions.

[0003] Traditional reverse microemulsions often use alkane organic solvents (such as cyclohexane, n-heptane, etc.) as the continuous phase. These solvents have the following technical defects: (1) they are highly volatile and toxic, posing a threat to human health; (2) they have poor biodegradability and cause serious environmental pollution; (3) they have limited compatibility with fiber and other substrates, making it difficult to meet the requirements of textile processing for the safety and environmental protection of auxiliaries.

[0004] Decamethylcyclopentasiloxane (D5) is a cyclic organosiloxane with a silicon-oxygen bond (Si-O) as its main chain. It is colorless, odorless, non-toxic, and oil-free, exhibiting strong hydrophobicity and good compatibility with most alcohols and other solvents. Compared to traditional hydrocarbon solvents, D5 is chemically stable at room temperature, does not readily react with acids or alkalis, and is heat-resistant and does not easily decompose. More importantly, D5 possesses excellent eco-friendliness—when it comes into contact with human skin, only about 0.05% is absorbed, and over 83% of the ingested amount is excreted through the circulatory system within 24 hours. As a continuous phase medium for reverse microemulsions, D5 meets the non-polar requirements of reverse micelle continuous phases while overcoming the environmental and health hazards of traditional hydrocarbon solvents, making it an ideal material for constructing green reverse microemulsions. However, the current technology for preparing reverse microemulsions using D5 as the continuous phase still has the following shortcomings: (1) the surfactant system has poor compatibility with the D5 oil phase, making it difficult to form a stable reverse microemulsion; (2) the system has a low amount of solubilizing water, which limits its ability to act as an aqueous reaction medium or degumming aid. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing highly soluble and highly stable silicon-based reverse microemulsions, the microemulsions prepared by this method having both high solubility and strong stability.

[0006] The second objective of this invention is to provide a highly solubilized and highly stable silicon-based reverse microemulsion.

[0007] A third objective of this invention is to provide the application of highly solubilized and highly stable silicon-based reverse microemulsions in natural fiber degumming, fabric finishing, or non-aqueous dyeing.

[0008] The first technical solution adopted in this invention is a method for preparing highly solubilized and highly stable silicon-based reverse microemulsions, specifically including the following steps: Step 1: Prepare the compound surfactant; Step 2: Add decamethylcyclopentasiloxane oil phase to the compound surfactant prepared in step 1, and sonicate at room temperature to ensure the system is fully mixed and homogeneous. Step 3: Under continuous sonication, deionized water is added dropwise to the mixture from Step 2, and sonication is continued until the system becomes transparent and homogeneous, thus obtaining the silicon-based reverse microemulsion.

[0009] The first technical solution of this invention is further characterized by: The specific process of step 1 is as follows: Weigh PEG / PPG-18 / 18 polydimethylsiloxane and n-hexanol, place them in a container and mix them evenly to obtain a compound surfactant.

[0010] In step 1, the mass ratio of PEG / PPG-18 / 18 polydimethylsiloxane to n-hexanol is 1~4:1.

[0011] In step 2, the ultrasonic treatment time is 5~15 min.

[0012] In step 2, the frequency of ultrasonic treatment is 40~60 kHz.

[0013] In step 2, the power of the ultrasonic treatment is 100~300 W.

[0014] In step 3, the dropping rate is 3~8 drops / second.

[0015] The second technical solution adopted in this invention is a highly solubilized and highly stable silicon-based reverse microemulsion, which is prepared by the above-mentioned method for preparing highly solubilized and highly stable silicon-based reverse microemulsion.

[0016] The third technical solution adopted in this invention is the application of highly solubilized and highly stable silicon-based reverse microemulsions in natural fiber degumming, fabric finishing, or non-aqueous dyeing.

[0017] The beneficial effects of this invention are as follows: (1) Using a PEG / PPG-18 / 18 polydimethylsiloxane and n-hexanol compound system, the organosilicon surfactant and D5 oil phase have excellent compatibility, the interfacial film strength and flexibility reach the optimal balance, and the saturated solubilized water content of the system is significantly improved.

[0018] (2) The microemulsion of the present invention does not exhibit stratification, precipitation, or turbidity when left to stand at room temperature for 7 h, and remains transparent and uniform even after ultrasonic treatment for 30 min, meeting the requirements for industrial storage and use.

[0019] (3) Using D5 as a continuous phase instead of traditional alkane organic solvents, D5 is non-toxic, easily degradable, and biocompatible, thus overcoming the environmental pollution and health risks of traditional hydrocarbon solvents.

[0020] (4) The present invention is prepared by room temperature ultrasonic method, which does not require high temperature and high pressure, is easy to operate and easy to scale up for industrial production. Attached Figure Description

[0021] Figure 1(a) is a pseudo-ternary phase diagram of the silicon-based reverse microemulsion prepared in Example 2 of the method for preparing highly soluble and highly stable silicon-based reverse microemulsions of the present invention; Figure 1(b) is a pseudo-ternary phase diagram of the silicon-based reverse microemulsion prepared in Example 3 of the method for preparing highly soluble and highly stable silicon-based reverse microemulsions of the present invention. Figure 1(c) is a pseudo-ternary phase diagram of the silicon-based reverse microemulsion prepared in Example 4 of the method for preparing highly soluble and highly stable silicon-based reverse microemulsions of the present invention. Figure 2 This is a bar chart showing the saturated solubilized water content of the microemulsions prepared in Examples 1-4 of the present invention's method for preparing highly solubilized and highly stable silicon-based reverse microemulsions. Figure 3 This is a graph showing the effect of temperature on the saturated solubilized water content of the microemulsions prepared in Examples 2-4 of the preparation method of the highly solubilized and highly stable silicon-based reverse microemulsion of the present invention. Figure 4 This is a graph showing the effect of pH value on the saturated solubilizing water content of the microemulsions prepared in Examples 2-4 of the present invention's method for preparing highly solubilized and highly stable silicon-based reverse microemulsions. Detailed Implementation

[0022] The following detailed description is provided in conjunction with specific implementation methods.

[0023] This invention relates to a highly solubilizing and highly stable silicone-based reverse microemulsion. It uses decamethylcyclopentasiloxane (D5) as the continuous oil phase, deionized water as the dispersed phase, PEG / PPG-18 / 18 polydimethylsiloxane as the surfactant, and n-hexanol as the co-surfactant. The microemulsion spontaneously forms a water-in-oil reverse microemulsion through the directional adsorption of the surfactant at the oil-water interface. The microemulsion is a transparent and homogeneous single-phase system. The volume percentage of D5 in the microemulsion is 60%–94%. The mass ratio of the surfactant PEG / PPG-18 / 18 polydimethylsiloxane to the co-surfactant n-hexanol is 1–4:1, preferably 3:1. The total amount of surfactant and co-surfactant added is 20–30 g / L (based on the total volume of the microemulsion).

[0024] The microemulsion showed no stratification, precipitation, or turbidity after standing at room temperature for more than 7 hours; it remained transparent and homogeneous even after ultrasonic treatment for 30 minutes.

[0025] The method for preparing highly solubilized and highly stable silicon-based reverse microemulsions of the present invention specifically includes the following steps: Step 1: Weigh PEG / PPG-18 / 18 polydimethylsiloxane and n-hexanol, place them in a container and mix them evenly to obtain a compound surfactant; the mass ratio of PEG / PPG-18 / 18 polydimethylsiloxane to n-hexanol is 1~4:1; PEG / PPG-18 / 18 polydimethylsiloxane is used as the surfactant and n-hexanol is used as the co-surfactant; the total amount of surfactant and co-surfactant added is 20~30 g / L.

[0026] Step 2: Add the set amount of D5 oil phase to the compound surfactant from Step 1, and sonicate at room temperature for 5-15 minutes to ensure the system is fully mixed and homogeneous; the frequency of sonication in Step 2 is 40-60 kHz, and the power of sonication is 100-300 W.

[0027] Step 3: Under continuous sonication, deionized water is slowly added dropwise to the mixture from Step 2, with a dropping rate controlled at 3-8 drops / second. Sonication continues until the system becomes transparent and homogeneous, thus obtaining the silicone-based reverse microemulsion. The amount of deionized water added in Step 3 shall not exceed the saturated solubilized water volume of the system; the saturated solubilized water volume is determined by titration, measured as the volume of deionized water consumed when the system changes from transparent to turbid and cannot be restored to clarity after stirring.

[0028] Example 1 (The mass ratio of surfactant to co-surfactant is 1:1) Step 1: Weigh 12.5 g of PEG / PPG-18 / 18 polydimethylsiloxane and 12.5 g of n-hexanol (mass ratio 1:1), place them in a container and mix them evenly to obtain a compound surfactant; Step 2: Add 940 mL of D5 oil phase to the above compound surfactant and sonicate in a CNC ultrasonic cleaner (frequency 40 kHz, power 200 W) for 10 min at room temperature to ensure thorough mixing of the system. Step 3: Under continuous sonication, deionized water (60 mL in total) is added dropwise at a constant rate of 50 μL / drop using a pipette, with the dropping rate controlled at 5 drops / second. The system is continuously sonicated until it becomes transparent and homogeneous, thus obtaining a silicone-based reverse microemulsion (total volume 1 L). Observe the state of the system; Figure 2 The bar chart shows that the saturated solubilized water content of the emulsion is relatively low. This indicates that the aqueous phase carrying capacity of this embodiment is limited, but it can form a stable microemulsion, avoiding the problem of hydrocarbon solvent contamination.

[0029] Example 2 (the mass ratio of surfactant to co-surfactant is 2:1) Step 1: Weigh 25.0 g of PEG / PPG-18 / 18 polydimethylsiloxane and 12.5 g of n-hexanol (mass ratio 2:1), place them in a container and mix them evenly; Step 2: Add 940 mL of D5 oil phase to the above compound surfactant and sonicate in a CNC ultrasonic cleaner (frequency 40 kHz, power 200 W) for 10 min at room temperature to ensure thorough mixing of the system. Step 3: Under continuous sonication, deionized water (60 mL in total) is added dropwise at a constant rate of 50 μL / drop using a pipette, with the dropping rate controlled at 5 drops / second. The system is continuously sonicated until it becomes transparent and homogeneous, thus obtaining a silicone-based reverse microemulsion (total volume 1 L). In this embodiment, five identical samples were prepared in parallel according to steps 1 to 3. The saturated solubility of the five samples was observed at temperatures of 60℃, 70℃, 80℃, 90℃, and 100℃, and the saturated solubility of the five samples was observed at pH values ​​of 5, 6, 7, 8, and 9.

[0030] The system exhibits good stability, and the finished microemulsion is transparent in appearance, showing no stratification after standing and sonication. Figure 1(a) shows a pseudo-ternary phase diagram indicating a relatively small stability range for the emulsion (the area to the right of the curve). Figure 2 The bar chart shows a low saturated solubilized water content in the emulsion. This indicates that the aqueous phase carrying capacity of this embodiment is limited, but it can form a stable microemulsion, avoiding hydrocarbon solvent contamination issues. Combined with... Figure 3 , Figure 4 It can be seen that the decrease in the amount of water dissolved decreases with increasing temperature, and the emulsion is stable in the pH range of 5 to 9.

[0031] Example 3 (the mass ratio of surfactant to co-surfactant is 3:1) Step 1: Weigh 37.5 g of PEG / PPG-18 / 18 polydimethylsiloxane and 12.5 g of n-hexanol (mass ratio 3:1), place them in a container and mix them evenly to obtain a compound surfactant; Step 2: Add 940 mL of D5 oil phase to the above compound surfactant and sonicate in a CNC ultrasonic cleaner (frequency 40 kHz, power 200 W) for 10 min at room temperature to ensure thorough mixing of the system. Step 3: Under continuous sonication, deionized water (60 mL in total) is added dropwise at a constant rate of 50 μL / drop using a pipette, with the dropping rate controlled at 5 drops / second. The system is continuously sonicated until it becomes transparent and homogeneous, thus obtaining a silicone-based reverse microemulsion (total volume 1 L). In this embodiment, five identical samples were prepared in parallel according to steps 1 to 3. The saturated solubility of the five samples was observed at temperatures of 60℃, 70℃, 80℃, 90℃, and 100℃, and the saturated solubility of the five samples was observed at pH values ​​of 5, 6, 7, 8, and 9.

[0032] Stability test: The prepared microemulsion was left to stand at room temperature for 7 h. The system remained transparent and homogeneous, without layering, precipitation, or turbidity. After being treated under ultrasonic conditions for 30 min, the system still remained transparent and homogeneous.

[0033] Figure 1(b) shows that the stable single-phase interval is the largest among the three groups; Figure 2 The medium-saturated solubilized water content is the highest, and the interfacial membrane structure matching is optimal. (Control) Figure 3 The water solubility reaches its peak at 60℃ and still retains sufficient capacity at 100℃. Figure 4 The results show that the emulsion's solubility is basically stable within the pH range of 5-9, and it has the best adaptability to temperature and acid / alkali conditions. This can solve the defects of existing D5 microemulsions, such as high temperature, easy pH fluctuation and instability, and insufficient solubility.

[0034] Example 4 (surfactant to active agent ratio 4:1) Step 1: Weigh 50.0 g of PEG / PPG-18 / 18 polydimethylsiloxane and 12.5 g of n-hexanol (mass ratio 4:1), place them in a container and mix them evenly to obtain a compound surfactant; Step 2: Add 940 mL of D5 oil phase to the above compound surfactant and sonicate in a CNC ultrasonic cleaner (frequency 40 kHz, power 200 W) for 10 min at room temperature to ensure thorough mixing of the system. Step 3: Under continuous sonication, deionized water (60 mL in total) is added dropwise at a constant rate of 50 μL / drop using a pipette, with the dropping rate controlled at 5 drops / second. The system is sonicated until it becomes transparent and homogeneous, thus obtaining a silicone-based reverse microemulsion (total volume 1 L).

[0035] Figure 2 It is evident that the stability range and the amount of solubilized water are lower than those in Examples 2 and 3. Figure 3 , Figure 4 The decrease in solubility of water was greater when the temperature increased and the pH shifted, and the emulsion stability was weaker than in Example 3.

[0036] In this embodiment, five identical samples were prepared in parallel according to steps 1 to 3. The saturated solubility of the five samples was observed at temperatures of 60℃, 70℃, 80℃, 90℃, and 100℃, and the saturated solubility of the five samples was observed at pH values ​​of 5, 6, 7, 8, and 9.

[0037] The system passed the static and ultrasonic stability tests. Refer to Figure 1(c) for the stable range. Figure 2 With increased saturated water content, the performance of this embodiment is superior to that of Embodiments 1 and 2, and the emulsion system has better compatibility with D5. Combined with... Figure 3 , Figure 4 It can be seen that the decrease in the amount of water dissolved decreases with increasing temperature, and the emulsion is stable in the pH range of 5 to 9.

[0038] Example 5 (D5 content 90%) Step 1: Weigh 37.5 g of PEG / PPG-18 / 18 polydimethylsiloxane and 12.5 g of n-hexanol, place them in a container and mix them evenly to obtain a compound surfactant; Step 2: Add 900 mL of D5 oil phase to the above compound surfactant and sonicate in a CNC ultrasonic cleaner (frequency 50 kHz, power 100 W) for 5 min at room temperature to ensure thorough mixing of the system. Step 3: Under continuous sonication, deionized water (100 mL in total) is added dropwise at a constant rate of 50 μL / time using a pipette, with the dropping rate controlled at 3 drops / second. The system is continuously sonicated until it becomes transparent and homogeneous, thus obtaining a silicone-based reverse microemulsion (total volume 1 L). The system is stable and has good solubilizing properties.

[0039] Example 6 (D5 content 98%) Step 1: Weigh 37.5 g of PEG / PPG-18 / 18 polydimethylsiloxane and 12.5 g of n-hexanol, place them in a container and mix them evenly to obtain a compound surfactant; Step 2: Add 980 mL of D5 oil phase to the above compound surfactant and sonicate in a CNC ultrasonic cleaner (frequency 60 kHz, power 300 W) for 15 min at room temperature to ensure thorough mixing of the system. Step 3: Under continuous sonication, deionized water (20 mL in total) is added dropwise at a rate of 50 μL / time using a pipette, with the dropping rate controlled at 8 drops / second. The sonication continues until the system becomes transparent and homogeneous, thus obtaining a silicone-based reverse microemulsion (total volume 1 L). The system has insufficient polarity and the amount of water solubilized is low.

[0040] Example 7 Step 1: Weigh 12.5 g of PEG / PPG-18 / 18 polydimethylsiloxane and 12.5 g of n-hexanol (mass ratio 1:1), place them in a container and mix them evenly to obtain a compound surfactant; Step 2: Add 940 mL of D5 oil phase to the above compound surfactant and sonicate in a CNC ultrasonic cleaner (frequency 40 kHz, power 200 W) at room temperature for 15 min to ensure thorough mixing of the system. Step 3: Under continuous sonication, deionized water (60 mL in total) is added dropwise at a constant rate of 50 μL / drop using a pipette, with the dropping rate controlled at 5 drops / second. The system is sonicated until it becomes transparent and homogeneous, thus obtaining a silicone-based reverse microemulsion (total volume 1 L).

[0041] Example 8 Step 1: Weigh 12.5 g of PEG / PPG-18 / 18 polydimethylsiloxane and 12.5 g of n-hexanol (mass ratio 1:1), place them in a container and mix them evenly to obtain a compound surfactant; Step 2: Add 940 mL of D5 oil phase to the above compound surfactant and sonicate in a CNC ultrasonic cleaner (frequency 40 kHz, power 300 W) for 15 min at room temperature to ensure thorough mixing of the system. Step 3: Under continuous sonication, deionized water (60 mL in total) is added dropwise at a constant rate of 50 μL / drop using a pipette, with the dropping rate controlled at 5 drops / second. The system is sonicated until it becomes transparent and homogeneous, thus obtaining a silicone-based reverse microemulsion (total volume 1 L).

Claims

1. A method for preparing highly solubilized and highly stable silicon-based reverse microemulsions, characterized in that: Specifically, the steps include the following: Step 1: Prepare the compound surfactant; Step 2: Add decamethylcyclopentasiloxane oil phase to the compound surfactant prepared in step 1, and sonicate at room temperature to ensure the system is fully mixed and homogeneous. Step 3: Under continuous sonication, deionized water is added dropwise to the mixture from Step 2, and sonication is continued until the system becomes transparent and homogeneous, thus obtaining the silicon-based reverse microemulsion.

2. The method for preparing the highly solubilized and highly stable silicon-based reverse microemulsion according to claim 1, characterized in that: The specific process of step 1 is as follows: Weigh PEG / PPG-18 / 18 polydimethylsiloxane and n-hexanol, place them in a container and mix them evenly to obtain a compound surfactant.

3. The method for preparing the highly solubilized and highly stable silicon-based reverse microemulsion according to claim 2, characterized in that: In step 1, the mass ratio of PEG / PPG-18 / 18 polydimethylsiloxane to n-hexanol is 1~4:

1.

4. The method for preparing the highly solubilized and highly stable silicon-based reverse microemulsion according to claim 2, characterized in that: In step 2, the ultrasonic treatment time is 5-15 minutes.

5. The method for preparing the highly solubilized and highly stable silicon-based reverse microemulsion according to claim 2, characterized in that: In step 2, the frequency of ultrasonic treatment is 40~60 kHz.

6. The method for preparing the highly solubilized and highly stable silicon-based reverse microemulsion according to claim 2, characterized in that: In step 2, the power of the ultrasonic treatment is 100~300 W.

7. The method for preparing the highly solubilized and highly stable silicon-based reverse microemulsion according to claim 2, characterized in that: In step 3, the dripping rate is 3-8 drops / second.

8. A highly solubilized and highly stable silicon-based reverse microemulsion, prepared by the method for preparing a highly solubilized and highly stable silicon-based reverse microemulsion as described in any one of claims 1 to 7.

9. Application of highly solubilizing and highly stable silicone-based reverse microemulsions in natural fiber degumming, fabric finishing, or non-aqueous dyeing.

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