Customized sequential multi-frequency ultrasound extraction method

Abstract

This invention discloses a custom sequential multi-frequency ultrasonic extraction method, comprising the following steps: mixing the extractant with an extraction solvent and placing the mixture into a multi-frequency ultrasonic extraction device, the multi-frequency ultrasonic extraction device including multiple ultrasonic transducers disposed on the bottom surface of an ultrasonic cylinder; turning on the multi-frequency ultrasonic extraction device and performing extraction according to preset operating parameters; the extraction is completed after extraction, the preset operating parameters including multiple ultrasonic frequencies increasing sequentially, the number of which is greater than or equal to three. The multi-frequency ultrasonic extraction method of this invention features high extraction accuracy, short extraction time, and simple operation.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic extraction technology, and in particular to a custom sequential multi-frequency ultrasonic extraction method. Background Technology

[0002] Ultrasonic technology plays a crucial role in chemical reactions, biological reactions, extraction of biological resources, and the enhancement of biomolecular degradation and modification. It primarily utilizes cavitation to generate localized high temperatures and pressures, intensifying the breaking of chemical bonds and promoting changes in molecular structure to achieve extraction. In extracting active ingredients, ultrasound can significantly reduce solvent usage, shorten extraction time, lower extraction temperature, and increase extraction yield. Similarly, in chemical and biological reactions, ultrasound can significantly shorten reaction time and increase reaction yield. Furthermore, the peak-to-peak superposition effect of multi-frequency ultrasound can further enhance the processing effect.

[0003] However, when multiple ultrasonic generators at different frequencies operate simultaneously and emit ultrasonic waves, the resulting synthetic spectrum is very complex. As the processing time increases, it will produce varying degrees of peak-to-peak addition and peak-to-peak cancellation, making it difficult to obtain a multi-frequency ultrasonic extraction method and system with controllable effects. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a custom sequential multi-frequency ultrasonic extraction method, aiming to solve the problem of difficulty in obtaining multi-frequency ultrasonic extraction methods and systems with controllable effects.

[0005] To achieve the above objectives, this invention proposes a custom sequential multi-frequency ultrasonic extraction method, comprising the following steps: mixing the extractant with an extraction solvent and placing it in a multi-frequency ultrasonic extraction device, wherein the multi-frequency ultrasonic extraction device includes multiple ultrasonic transducers disposed on the bottom surface of an ultrasonic cylinder; turning on the multi-frequency ultrasonic extraction device and performing extraction according to preset operating parameters, wherein the extraction is completed after extraction; wherein the preset operating parameters include multiple ultrasonic frequencies that increase sequentially, and the number of the multiple ultrasonic frequencies is greater than or equal to 3.

[0006] In some embodiments, the extraction method is used to extract restricted chemical additives that combine with polymer materials through physical adsorption to improve the properties of polymer materials.

[0007] In some embodiments, the polymeric material includes one of PVC, PP, PET, and PU.

[0008] In some embodiments, the number of the plurality of ultrasonic transducers is 4 to 8, and any 3 ultrasonic transducers can form a parallel triangular array arrangement.

[0009] In some embodiments, the piezoelectric material of the ultrasonic transducer is lead magnesium niobate-lead titanate piezoelectric single crystal material or lead zirconate titanate piezoelectric ceramic material.

[0010] In some embodiments, the piezoelectric constant of the piezoelectric material ranges from 300 pC / N to 706 pC / N; and / or, the electromechanical coupling coefficient k of the piezoelectric material... 33 The value ranges from 0.57 to 0.75.

[0011] In some embodiments, the multi-frequency ultrasonic extraction device includes an ultrasonic cylinder, which is cylindrical in shape and made of titanium alloy.

[0012] In some embodiments, the preset operating parameters include 3 to 6 ultrasonic frequencies that increase sequentially.

[0013] In some embodiments, the preset operating parameters include 3 to 6 ultrasonic frequencies that increase sequentially from the ultrasonic frequency bands specified by f1 (15kHz to 25kHz), f2 (25kHz to 35kHz), f3 (35kHz to 45kHz), f4 (55kHz to 65kHz), f5 (65kHz to 85kHz), and f6 (85kHz to 120kHz).

[0014] In some embodiments, the preset operating parameters include an extraction temperature of 50°C to 65°C; and / or, the preset operating parameters include an ultrasonic power of 400W to 1000W; and / or, the preset operating parameters include an extraction time of 20min to 40min.

[0015] The beneficial effects of this invention are:

[0016] The custom sequential multi-frequency ultrasonic extraction method provided by this invention utilizes multiple transducers working in parallel to provide adjustable total power and frequency bands. Combined with transducers uniformly arranged around the center of the cylinder bottom, it achieves high-intensity ultrasonic output, enhancing the cavitation effect. At the same time, through transducer arrangement simulation optimization, it ensures the uniformity of sound intensity in the cylindrical region centered on the bottom center, thereby improving the uniformity of the sound field. This results in high extraction accuracy, short extraction time, and simple operation. Attached Figure Description

[0017] Figure 1 These are scanning electron microscope images of custom-order multi-frequency ultrasonic extraction at different times according to an embodiment of the present invention, all at a magnification of 5000x.

[0018] Figure 2 This is a structural diagram of a custom sequential multi-frequency ultrasonic device comprising six ultrasonic transducers according to an embodiment of the present invention;

[0019] Figure 3This is a schematic diagram of the ultrasonic transducer layout of a multi-frequency ultrasonic device including six ultrasonic transducers according to an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the ultrasonic transducer layout of a multi-frequency ultrasonic device including seven ultrasonic transducers according to an embodiment of the present invention.

[0021] The reference numerals in the attached diagrams are as follows: 1-ultrasonic transducer, 2-ultrasonic cylinder, 3-sample tube, 4-sample tray, 5-support tray.

[0022] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0023] To make the technical solution and advantages of the present invention clearer, the present invention and its beneficial effects will be described in further detail below in conjunction with specific embodiments. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter recorded in the claims.

[0024] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0025] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0026] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0027] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0028] Ultrasonic technology plays a crucial role in chemical reactions, biological reactions, extraction of biological resources, and the enhancement of biomolecular degradation and modification. It primarily utilizes cavitation to generate localized high temperatures and pressures, intensifying the breaking of chemical bonds and promoting changes in molecular structure to achieve extraction. In extracting active ingredients, ultrasound can significantly reduce solvent usage, shorten extraction time, lower extraction temperature, and increase extraction yield. Similarly, in chemical and biological reactions, ultrasound can significantly shorten reaction time and increase reaction yield. Furthermore, the peak-to-peak superposition effect of multi-frequency ultrasound can further enhance the processing effect.

[0029] However, when multiple ultrasonic generators at different frequencies operate simultaneously and emit ultrasonic waves, the resulting synthetic spectrum is very complex. As the processing time increases, it will produce varying degrees of peak-to-peak addition and peak-to-peak cancellation, making it difficult to obtain a multi-frequency ultrasonic extraction method and system with controllable effects.

[0030] In view of this, the present invention proposes a custom sequential multi-frequency ultrasonic extraction method, comprising the following steps: mixing the extractant with an extraction solvent and placing it in a multi-frequency ultrasonic extraction device, wherein the multi-frequency ultrasonic extraction device includes multiple ultrasonic transducers disposed on the bottom surface of an ultrasonic cylinder; turning on the multi-frequency ultrasonic extraction device and performing extraction according to preset working parameters, wherein the extraction is completed after the extraction is completed, wherein the preset working parameters include multiple ultrasonic frequencies that increase sequentially, and the number of the multiple ultrasonic frequencies is greater than or equal to 3.

[0031] The coordinated operation of multiple ultrasonic transducers can significantly improve the utilization rate of ultrasonic energy and avoid the problem of rapid attenuation of ultrasonic energy with increasing propagation distance. Multi-transducer systems can optimize the sound field distribution to ensure that the material receives uniform ultrasonic action at all locations, thereby improving overall extraction efficiency. Different frequencies of ultrasound have different mechanisms of action during extraction. Low-frequency ultrasound typically has a stronger cavitation effect, while high-frequency ultrasound is more conducive to vibration effects. By using multiple transducers to achieve multi-frequency coordinated operation, the advantages of different frequencies of ultrasound can be fully utilized. Multi-transducer systems can flexibly adapt to different extraction targets and process requirements by adjusting the number, position, and operating frequency of the transducers.

[0032] This scheme utilizes multiple transducers working in parallel to provide adjustable total power and frequency bands. Combined with transducers evenly arranged around the center of the cylinder bottom, it achieves high-intensity ultrasonic output and enhances the cavitation effect. At the same time, through transducer arrangement simulation optimization, it ensures the uniformity of sound intensity in the cylindrical region centered on the bottom center, thereby improving the uniformity of the sound field. This results in high extraction accuracy, short extraction time, and simple operation.

[0033] In some embodiments, see Figure 2 A multi-frequency ultrasonic extraction device includes at least an ultrasonic transducer 1 capable of generating ultrasonic waves of multiple frequencies, an ultrasonic cylinder 2, a sample tube 3, a sample tray 4, and a support tray 5. In some embodiments, the multi-frequency ultrasonic extraction device also includes components such as a multi-frequency control circuit board and a touch panel.

[0034] In some embodiments, the ratio of the extract to the extraction solvent is 1g:20mL to 50mL, and the extraction solvent may be dichloromethane, n-hexane, etc.

[0035] In some embodiments, the extraction method is used to extract restricted chemical additives that combine with polymer materials through physical adsorption to improve the properties of polymer materials.

[0036] In some embodiments, restricted chemical additives include phthalate esters (PAEs) plasticizers, polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs), all of which are suitable for the extraction system of this scheme. Phthaate esters (PAEs) plasticizers are a class of chemicals synthesized by esterification of phthalic acid with alcohol compounds. They are widely used as plasticizers to increase the flexibility and plasticity of plastics. Common PAEs include di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and diisooctyl phthalate (DINP).

[0037] In some embodiments, the polymeric material includes one of polyvinyl chloride (PVC), polypropylene (PP), polyethylene terephthalate (PET), and polyurethane (PU). Phthalate esters (PAEs) are used in PVC, PP, PET, and PU to increase the flexibility, chemical resistance, and impact resistance of plastics. The use of PAEs in these materials is strictly limited in children's products and food applications. Phthalate esters may also damage the liver and immune system and increase the risk of cancer. Furthermore, they accumulate through the food chain, potentially exacerbating health risks, and due to their environmental persistence and bioaccumulation, they have become environmental pollutants of global concern. Therefore, extracting PAEs from these materials is of profound significance for maintaining human health.

[0038] In some embodiments, the number of ultrasonic transducers is 4 to 8, and any three ultrasonic transducers can form a parallel triangular array arrangement. In some embodiments, the number of ultrasonic transducers is preferably 6 to 7, see the appendix to the specification. Figure 3 and attached Figure 4 In some embodiments, the ultrasonic transducers are arranged in a triangular array with a spacing of more than 50 mm between them, forming a triangular distribution of oscillators to avoid an excessively large low-pressure area and to maintain the stability and uniformity of energy throughout the ultrasonic extraction process. The triangle is an isosceles or equilateral triangle.

[0039] In some embodiments, the piezoelectric material of the ultrasonic transducer is a lead magnesium niobate-lead titanate piezoelectric single crystal material or a lead zirconate titanate piezoelectric ceramic material. The ultrasonic transducer is designed to generate ultrasonic waves of various specific frequencies, and the aforementioned materials are suitable for high-frequency vibrations and possess high piezoelectric constants and suitable electromechanical coupling coefficients.

[0040] In some embodiments, the piezoelectric constant of the piezoelectric material ranges from 300 pC / N to 706 pC / N; and / or, the electromechanical coupling coefficient k of the piezoelectric material... 33 The values ​​range from 0.57 to 0.75. Utilizing the thickness stretching and shearing vibration characteristics of these piezoelectric materials, combined with frequency matching and impedance matching, this transducer can effectively generate ultrasonic waves of various frequencies. By combining the time of these frequencies, it ensures more effective breaking of intermolecular forces between chemical substances at different stages during multi-frequency continuous ultrasonic extraction, thereby improving extraction efficiency. Various polymer materials can achieve rapid and efficient processing, significantly increasing the ultrasonic extraction power for PAEs.

[0041] In some embodiments, the multi-frequency ultrasonic extraction device includes an ultrasonic cylinder, which is cylindrical in shape and made of titanium alloy.

[0042] In some embodiments, titanium alloy types include TC4, TC6, TC17, etc. Titanium alloy materials can achieve a tensile strength of up to 1700 MPa, an elongation between 6% and 20%, and a fatigue limit of 250–450 MPa. Compared to stainless steel's 1500 MPa ultimate tensile strength, 5% to 30% elongation, and 200–300 MPa fatigue limit, titanium alloys offer longer lifespan and higher strength. These characteristics endow titanium alloy materials with excellent deformation resistance and good resonance properties, ensuring that the high-frequency vibration energy generated by the ultrasonic transducer can be effectively and continuously transferred to the medium inside the cylinder.

[0043] Meanwhile, the cylinder adopts a cylindrical design, which has geometric symmetry. The ultrasonic waves are distributed more evenly in the cylinder medium, and the acoustic flow distribution of the cylindrical structure is more uniform, which improves the penetration of ultrasonic waves and the energy utilization efficiency; it also reduces the standing wave phenomenon caused by sound wave reflection and scattering at the boundary.

[0044] In some embodiments, the preset operating parameters include 3 to 6 sequentially increasing ultrasonic frequencies. Using multiple increasing ultrasonic frequencies allows for better adaptation to the physical and chemical properties of different materials. Low-frequency ultrasound can generate a stronger cavitation effect, helping to disrupt the structure of polymer materials and making it easier for plasticizers to be released; while high-frequency ultrasound can further enhance the contact between the solvent and the plasticizer, accelerating the diffusion process. Different frequencies of ultrasound may have different mechanisms of action on different types of plasticizers. By using multiple frequencies, the extraction process can be completed more efficiently compared to single-frequency ultrasonic extraction. Using multiple frequencies allows for better adaptation to the characteristics of different materials, thus achieving wider applicability, and the optimized combination of ultrasonic frequencies can achieve high extraction efficiency in a shorter time while reducing the amount of solvent used.

[0045] In some embodiments, the preset operating parameters include 3 to 6 ultrasonic frequencies in ascending order from the specified ultrasonic frequency bands: f1 (15kHz–25kHz), f2 (25kHz–35kHz), f3 (35kHz–45kHz), f4 (55kHz–65kHz), f5 (65kHz–85kHz), and f6 (85kHz–120kHz). The size of the bubbles produced by different ultrasonic frequencies varies. At the initial stage of ultrasonic extraction, the f1 frequency produces large bubbles with high energy upon rupture, making it suitable for initial extraction. As the ultrasonic time increases, the sample gradually swells from the outside in. To avoid damaging the polymer matrix and interfering with subsequent analysis, the extraction is further performed at the higher frequency and lower energy of f2. As time progresses, the extraction is then performed at frequencies f3, f4, f5, and f6. The internal logic includes automatic heating and cooling start-up based on temperature, and ultrasonic extraction based on user-set frequencies and power, ensuring efficient and safe operation of the device under various operating conditions.

[0046] In some embodiments, the preset operating parameters include an extraction temperature of 50°C to 65°C; and / or, the preset operating parameters include an ultrasonic power of 400W to 1000W; and / or, the preset operating parameters include an extraction time of 20min to 40min. Three or more combinations of operating times with different frequencies are selected for different types of polymer materials to improve the extraction efficiency of restricted substances (PAEs).

[0047] Example 1:

[0048] The custom sequential multi-frequency ultrasonic extraction device is designed with seven transducers arranged in a parallel triangular array on the bottom surface of a titanium alloy cylinder. A 2-5 mm cylindrical PVC standard sample containing a certain amount of phthalate plasticizer is placed in the sample tray.

[0049] The sample was mixed with 99.9% analytical grade dichloromethane at a ratio of 1 g: 25 mL.

[0050] Perform multi-frequency ultrasonic extraction according to preset parameters and sequence: control the extraction environment temperature at 58℃~62℃, turn on the ultrasonic for 3 minutes, select f1 (23kHz) for 10 minutes, f2 (35kHz) for 10 minutes, f3 (40kHz) for 5 minutes, f4 (60kHz) for 5 minutes, set the power to 500W, and the total extraction time is 30 minutes.

[0051] Example 2:

[0052] The custom sequential multi-frequency ultrasonic extraction device is designed with seven transducers arranged in a parallel triangle on the bottom of a stainless steel cylinder. A 2-5 mm cylindrical PVC standard sample containing a certain amount of phthalate plasticizer is placed in the sample tray.

[0053] The sample was mixed with 99.9% analytical grade dichloromethane at a ratio of 1 g: 25 mL.

[0054] Perform multi-frequency ultrasonic extraction according to preset parameters and sequence: control the extraction environment temperature at 58℃~62℃, turn on the ultrasonic for 3 minutes, select f1 (23kHz) for 10 minutes, f2 (35kHz) for 10 minutes, f3 (40kHz) for 7.5 minutes, f4 (60kHz) for 7.5 minutes, set the power to 500W, and the total extraction time is 35 minutes.

[0055] Example 3:

[0056] The self-sequential multi-frequency ultrasonic extraction device is designed with seven transducers arranged in a parallel triangle on the bottom surface of a titanium alloy cylinder. A 2-5 mm cylindrical PU standard sample containing a certain amount of phthalate plasticizer is placed in the sample tray.

[0057] The sample was mixed with 99.9% analytical grade dichloromethane at a ratio of 1 g: 25 mL.

[0058] Multi-frequency ultrasonic extraction was performed according to preset parameters and sequence: the material temperature was controlled at 58℃~62℃, and after the ultrasonic was turned on for 3 minutes, f1 (20kHz) for 15 minutes, f2 (35kHz) for 10 minutes, f4 (58kHz) for 10 minutes, and f5 (82kHz) for 5 minutes were selected. The power was set to 500W, and the total extraction time was 40 minutes.

[0059] Example 4:

[0060] The self-sequential multi-frequency ultrasonic extraction device is designed with seven transducers arranged in a parallel triangle on the bottom surface of a titanium alloy cylinder. A 2-5 mm cylindrical PET standard sample containing a certain amount of phthalate plasticizer is placed in the sample tray.

[0061] The sample was mixed with 99.9% analytical grade dichloromethane at a ratio of 1 g: 25 mL.

[0062] Perform multi-frequency ultrasonic extraction according to preset parameters and sequence: control the material temperature at 50℃~58℃, turn on the ultrasonic for 3 minutes, select f1 (23kHz) for 15 minutes, f3 (40kHz) for 10 minutes, f4 (58kHz) for 5 minutes, f5 (82kHz) for 5 minutes, set the power to 500W, and the total extraction time is 35 minutes.

[0063] Example 5:

[0064] The custom sequential multi-frequency ultrasonic extraction device is designed with six transducers arranged in a parallel triangular array on the bottom surface of a titanium alloy cylinder. A 2-5 mm cylindrical PVC standard sample containing a certain amount of phthalate plasticizer is placed in the sample tray.

[0065] The sample was mixed with 99.9% analytical grade dichloromethane at a ratio of 1 g: 25 mL.

[0066] Multi-frequency ultrasonic extraction was performed according to preset parameters and sequence: the extraction environment temperature was controlled at 58℃~65℃, and after the ultrasonic was turned on for 3 minutes, f1 (23kHz) for 10 minutes, f2 (35kHz) for 10 minutes, f3 (40kHz) for 7.5 minutes, f4 (60kHz) for 5 minutes, and f5 (82kHz) for 5 minutes were selected. The power was set to 500W, and the total extraction time was 37.5 minutes.

[0067] Comparative Example 1:

[0068] The custom sequential multi-frequency ultrasonic extraction device is designed with a transducer on the bottom of a titanium alloy cylinder. A 2-5 mm cylindrical PVC standard sample containing a certain amount of phthalate plasticizer is placed in the sample tray.

[0069] The sample was mixed with 99.9% analytical grade dichloromethane at a ratio of 1 g: 25 mL.

[0070] Perform multi-frequency ultrasonic extraction according to preset parameters and sequence: control the extraction environment temperature at 58℃~62℃, turn on the ultrasonic for 3 minutes, select f1 (23kHz) for 10 minutes, f2 (35kHz) for 10 minutes, f3 (40kHz) for 5 minutes, f4 (60kHz) for 5 minutes, set the power to 100W, and the total extraction time is 35 minutes.

[0071] Comparative Example 2:

[0072] The custom sequential multi-frequency ultrasonic extraction device is designed with seven transducers on the bottom surface of a titanium alloy cylinder. A 2-5 mm cylindrical PVC standard sample containing a certain amount of phthalate plasticizer is placed in the sample tray.

[0073] The sample was mixed with 99.9% analytical grade dichloromethane at a ratio of 1 g: 25 mL.

[0074] Perform multi-frequency ultrasonic extraction according to preset parameters and sequence: control the extraction environment temperature at 58℃~62℃, turn on the ultrasonic for 3 minutes, select f3 (38kHz) for 20 minutes and f5 (80kHz) for 20 minutes, set the power to 500W, and the total extraction time is 40 minutes.

[0075] The yield results of Examples 1-5 and Comparative Examples 1-2 are summarized in Table 1. The yield data were obtained by gas chromatography-mass spectrometry analysis, and the integration process involved precise measurement of chromatographic peaks. The start and end times of each peak were marked, peak boundaries were defined, peak apex was determined to obtain retention time for qualitative analysis, a baseline was established to distinguish background signals from target peaks, peak area, peak height, and peak width were calculated, and quantitative analysis and evaluation of chromatographic separation effect were performed. Software tools and manual integration adjustments were combined to ensure the accuracy and reliability of the results. The abbreviations in Table 1 represent: di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), butyl benzyl phthalate (BBP), dicyclohexyl phthalate (DCHP), and diethyl phthalate (DEP).

[0076] Table 1.

[0077]

[0078] Please refer to Table 1 and see also... Figure 1 In Example 1, during the ultrasonic extraction process, the bubble size generated by the 20-100kHz ultrasound ranged from 397.452μm to 66.242μm, which matched the pore size of the PVC. In the early stage, at 5 minutes of extraction, the Brownian motion of the plasticizer molecules was more intense than that of the larger molecules, and they diffused to the surface of the product at a high migration rate, forming pores of 1μm in size. As time progressed, at 20 minutes, dichloromethane, as the extractant, had strong polarity and made deep contact with the PVC polymer, destroying the secondary structure of the polymer, enhancing the mobility of PVC molecules, and causing the PVC material to swell. The plasticizer molecules migrated further, and the gaps between the PVC particles increased further. At this time, high-frequency ultrasonic extraction was used to generate tiny ultrasonic bubbles that entered the PVC gaps. While avoiding further damage to the PVC surface, the phthalate plasticizers in the PVC particles were extracted more deeply. At 40 minutes of extraction, the internal plasticizers were almost completely extracted, but some residues remained. Therefore, higher frequency ultrasound was used to generate even smaller bubbles that penetrated deeper into the PVC matrix, achieving deeper extraction.

[0079] In summary, the custom sequential multi-frequency ultrasonic extraction method provided by this invention utilizes multiple transducers working in parallel to provide adjustable total power and frequency bands. Combined with transducers uniformly arranged around the center of the cylinder bottom, it achieves high-intensity ultrasonic output, enhancing the cavitation effect. At the same time, through transducer arrangement simulation optimization, it ensures the uniformity of sound intensity in the cylindrical region centered on the bottom center, thereby improving the uniformity of the sound field. This results in high extraction accuracy, short extraction time, and simple operation.

[0080] Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples.

[0081] The above description is only a part or preferred embodiment of the present invention. Neither the text nor the drawings should limit the scope of protection of the present invention. All equivalent structural transformations made using the content of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A custom-ordered multi-frequency ultrasonic extraction method, characterized in that, Includes the following steps: The extractant is mixed with the extraction solvent and placed in a multi-frequency ultrasonic extraction device, which includes multiple ultrasonic transducers disposed on the bottom surface of the ultrasonic cylinder. Turn on the multi-frequency ultrasonic extraction device and perform extraction according to the preset working parameters. After the extraction is completed, the extraction is finished. The preset working parameters include multiple ultrasonic frequencies that increase sequentially. The number of ultrasonic frequencies is greater than or equal to 3. The preset working parameters include 3 to 6 ultrasonic frequencies that increase sequentially with the ultrasonic time in the ultrasonic frequency band specified by f1, f2, f3, f4, f5, and f6, and 15kHz≤f1≤25kHz, 25kHz≤f2≤35kHz, 35kHz≤f3≤45kHz, 55kHz≤f4≤65kHz, 65kHz≤f5≤85kHz, and 85kHz≤f6≤120kHz. The extraction method is used to extract restricted chemical additives that improve the properties of polymer materials by combining with them through physical adsorption. These restricted chemical additives include phthalate plasticizers. 、 One of polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs), wherein the polymer material includes polyvinyl chloride (PVC). 、 One of polypropylene, polyethylene terephthalate, and polyurethane.

2. The custom-order multi-frequency ultrasonic extraction method according to claim 1, characterized in that, The number of ultrasonic transducers is 4 to 8, and any 3 ultrasonic transducers can form a parallel triangular array arrangement.

3. The custom sequential multi-frequency ultrasonic extraction method according to claim 1, characterized in that, The piezoelectric material of the ultrasonic transducer is lead magnesium niobate-lead titanate piezoelectric single crystal material or lead zirconate titanate piezoelectric ceramic material.

4. The custom sequential multi-frequency ultrasonic extraction method according to claim 3, characterized in that, The piezoelectric constant of the piezoelectric material is in the range of 300 pC / N to 706 pC / N; And / or, the electromechanical coupling coefficient k of the piezoelectric material 33 The value is 0.57~0.

75.

5. The custom sequential multi-frequency ultrasonic extraction method according to claim 1, characterized in that, The multi-frequency ultrasonic extraction device includes an ultrasonic cylinder, which is cylindrical in shape and made of titanium alloy.

6. The custom-sequence multi-frequency ultrasonic extraction method according to claim 1, characterized in that, The preset operating parameters include 3 to 6 ultrasonic frequencies that increase sequentially.

7. The custom-sequence multi-frequency ultrasonic extraction method according to claim 1, characterized in that, The preset operating parameters include an extraction temperature of 50℃~65℃; And / or, the preset operating parameters include an ultrasonic power of 400W~1000W; And / or, the preset working parameters include an extraction time of 20 min to 40 min.

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