Custom sequence multi-frequency ultrasonic extraction method

Abstract

The invention discloses a user-defined sequence multi-frequency ultrasonic extraction method which comprises the following steps: mixing an object to be extracted with an extraction solvent, and putting the mixture into a multi-frequency ultrasonic extraction device which comprises a plurality of ultrasonic transducers arranged on the bottom surface of an ultrasonic cylinder body; the multi-frequency ultrasonic extraction device is started, extraction is carried out according to preset working parameters, extraction is completed after extraction is finished, the preset working parameters comprise multiple ultrasonic frequencies which are gradually increased in sequence, and the number of the multiple ultrasonic frequencies is larger than or equal to 3. The multi-frequency ultrasonic extraction method disclosed by the invention is high in extraction precision, short in time consumption and simple and convenient to operate.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic extraction, and in particular to a user-defined sequential multi-frequency ultrasonic extraction method. Background Art

[0002] Ultrasonic technology plays an important role in chemical reactions, biological reactions, extraction of biological resources, and enhancement of degradation and modification of biomacromolecules. It mainly produces local high temperature and high pressure through cavitation, strengthens chemical bond breaking, promotes molecular structure changes, and achieves the purpose of extraction. When extracting effective ingredients, ultrasound can significantly reduce the amount of solvent, shorten the extraction time, reduce the extraction temperature, and increase the extraction rate. In chemical and biological reactions, ultrasound can also significantly shorten the reaction time and increase the reaction yield. The effect of multi-frequency ultrasonic peak superposition can be used to further improve the treatment effect of ultrasound.

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

[0004] In view of the shortcomings of the prior art, the present invention provides a customized sequential multi-frequency ultrasonic extraction method, aiming to solve the problem that it is difficult to obtain a multi-frequency ultrasonic extraction treatment method and system with controllable effects.

[0005] In order to achieve the above-mentioned purpose, the present invention proposes a custom sequential multi-frequency ultrasonic extraction method, comprising the following steps: mixing the object to be extracted with the extraction solvent and placing them in a multi-frequency ultrasonic extraction device, wherein the multi-frequency ultrasonic extraction device comprises a plurality of ultrasonic transducers arranged on the bottom surface of an ultrasonic cylinder; turning on the multi-frequency ultrasonic extraction device, and performing extraction according to preset working parameters, after which the extraction is completed, wherein the preset working parameters comprise a plurality of ultrasonic frequencies that increase in sequence, and the number of the plurality of ultrasonic frequencies is greater than or equal to 3.

[0006] In some embodiments, the extraction method is used to extract restricted chemical additives that are combined with polymer materials by physical adsorption to improve the performance of polymer materials.

[0007] In some embodiments, the polymer 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 three ultrasonic transducers can form a parallel triangular array arrangement.

[0009] 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.

[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 It is 0.57~0.75.

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

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

[0013] In some embodiments, the preset operating parameters include 3 to 6 ultrasonic frequencies that increase in sequence in 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 working parameters include an extraction temperature of 50°C to 65°C; and / or, the preset working parameters include an ultrasonic power of 400w to 1000w; and / or, the preset working parameters include an extraction time of 20min to 40min.

[0015] Beneficial effects of the present invention:

[0016] The customized sequential multi-frequency ultrasonic extraction method provided by the present invention utilizes multiple transducers working in parallel to provide adjustable total power and band frequency, and combines the transducers evenly arranged at the center and around the bottom surface of the cylinder to achieve high-intensity ultrasonic output and enhance the cavitation effect. At the same time, through the simulation optimization of the transducer arrangement, the uniformity of the sound intensity in the cylindrical area with the bottom center as the center is ensured, thereby improving the uniformity of the sound field, so that the final extraction has high precision, short time consumption and simple operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a scanning electron microscope image of a custom sequential multi-frequency ultrasonic extraction at different times according to an embodiment of the present invention, and the magnification is 5000 times;

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

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

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

[0021] Wherein, the accompanying drawings indicate: 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 embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0023] In order to make the technical solutions and advantages of the present invention clearer, the present invention and its beneficial effects will be further described in detail below in conjunction with specific implementation methods. The drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter recorded in the claims.

[0024] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0025] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0026] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0027] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0028] Ultrasonic technology plays an important role in chemical reactions, biological reactions, extraction of biological resources, and enhancement of degradation and modification of biomacromolecules. It mainly produces local high temperature and high pressure through cavitation, strengthens chemical bond breaking, promotes molecular structure changes, and achieves the purpose of extraction. When extracting effective ingredients, ultrasound can significantly reduce the amount of solvent, shorten the extraction time, reduce the extraction temperature, and increase the extraction rate. In chemical and biological reactions, ultrasound can also significantly shorten the reaction time and increase the reaction yield. The effect of multi-frequency ultrasonic peak superposition can be used to further improve the treatment effect of ultrasound.

[0029] However, when ultrasonic generators of multiple frequencies currently work and emit ultrasonic waves simultaneously, the resulting synthetic spectrum is very complex, and as the processing time increases, peak-to-peak addition and peak-to-peak cancellation will occur to varying degrees, making it difficult to obtain a multi-frequency ultrasonic extraction processing 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 object to be extracted with the extraction solvent, and placing the mixture into a multi-frequency ultrasonic extraction device, wherein the multi-frequency ultrasonic extraction device comprises a plurality of ultrasonic transducers arranged on the bottom surface of an ultrasonic cylinder; turning on the multi-frequency ultrasonic extraction device, and performing extraction according to preset working parameters, and the extraction is completed after the extraction is completed, wherein the preset working parameters comprise a plurality of ultrasonic frequencies that increase in sequence, and the number of the plurality of ultrasonic frequencies is greater than or equal to 3.

[0031] The coordinated work of multiple ultrasonic transducers can significantly improve the utilization rate of ultrasonic energy and avoid the problem of rapid attenuation of ultrasonic energy as the propagation distance increases. The multi-transducer system can optimize the sound field distribution to ensure that the material is uniformly subjected to ultrasonic action at all positions, thereby improving the overall extraction efficiency. Ultrasonic waves of different frequencies have different action mechanisms in the extraction process. Low-frequency ultrasonic waves usually have a stronger cavitation effect, while high-frequency ultrasonic waves are more conducive to vibration effects. By using multiple transducers to achieve multi-band coordinated work, the advantages of ultrasonic waves of different frequencies can be fully utilized. The multi-transducer system can flexibly adapt to different extraction objects and process requirements by adjusting the number, position and operating frequency of the transducers and the multi-band synergy.

[0032] In this solution, multiple transducers are used in parallel to provide adjustable total power and band frequency. Combined with the transducers evenly arranged in the center and around the bottom surface of the cylinder, high-intensity ultrasonic output is achieved to enhance the cavitation effect. At the same time, through the simulation optimization of the transducer arrangement, the uniformity of the sound intensity in the cylindrical area with the bottom center as the center is ensured, thereby improving the uniformity of the sound field, making the final extraction high in precision, short in time and easy to operate.

[0033] In some embodiments, see Figure 2 The multi-frequency ultrasonic extraction device at least comprises 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 further comprises components such as a multi-frequency control circuit board and a touch panel.

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

[0035] In some embodiments, the extraction method is used to extract restricted chemical additives that are combined with polymer materials by physical adsorption to improve the performance of polymer materials.

[0036] In some embodiments, the restricted chemical additives include phthalate esters (PAEs) plasticizers, polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs), all of which are applicable to the extraction system of this solution. Phthalate esters (PAEs) plasticizers are a class of chemicals synthesized by esterification of phthalic acid and 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 di-isooctyl phthalate (DINP).

[0037] In some embodiments, the polymer material includes one of polyvinyl chloride (PVC), polypropylene (PP), polyethylene terephthalate (PET), and polyurethane (PU). PAEs are used in PVC, PP, PET, and PU for the purpose of increasing the flexibility, chemical resistance, and impact resistance of plastics. The use of phthalates in the above-mentioned materials is strictly restricted in the fields of children's products and food applications. Phthalate compounds may also cause damage to the liver and immune system and increase the risk of cancer. In addition, they are enriched through the food chain, which may further aggravate health risks. Due to their environmental persistence and bioaccumulation, they have become environmental pollutants of global concern. Therefore, the extraction of PAEs in the above-mentioned materials has profound significance for the maintenance of human health.

[0038] In some embodiments, the number of the plurality 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 attached specification. Figure 3 and attached Figure 4 In some embodiments, the ultrasonic transducers are arranged in a triangular array with a distance of more than 50 mm, forming a triangular distributed vibrator to avoid excessive low pressure area and maintain energy stability and uniformity during the entire ultrasonic extraction process, and 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. The above materials are suitable for high-frequency vibration and have a high piezoelectric constant and a suitable electromechanical coupling coefficient.

[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 0.57~0.75. By utilizing the thickness stretch vibration and thickness shear vibration characteristics generated by these piezoelectric materials, combined with frequency matching and impedance matching, the transducer can effectively generate ultrasonic waves of various frequencies. Through the time combination of multiple frequencies, it is ensured that in the multi-frequency continuous ultrasonic extraction process, the intermolecular forces between chemical substances are more effectively broken at different stages, thereby improving the extraction efficiency. Various polymer materials can achieve fast and efficient processing effects, greatly improving the ultrasonic extraction power for PAEs.

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

[0042] In some embodiments, the titanium alloy models include TC4, TC6, TC17, etc. Titanium alloy materials can reach a tensile strength of up to 1700MPa, an elongation of 6% to 20%, and a fatigue limit of 250 to 450MPa. Compared with the ultimate tensile strength of 1500MPa, the elongation of 5% to 30%, and the fatigue limit of 200 to 300MPa of stainless steel, titanium alloy materials have a longer life and higher strength. These characteristics give titanium alloy materials excellent deformation resistance and good resonance characteristics, ensuring that the high-frequency vibration energy generated by the ultrasonic transducer can be effectively and continuously transmitted to the medium in the cylinder.

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

[0044] In some embodiments, the preset working parameters include 3 to 6 ultrasonic frequencies that increase in sequence. The use of multiple increasing ultrasonic frequencies can better adapt to the physical and chemical properties of different materials. Low-frequency ultrasound can produce a stronger cavitation effect, which helps to destroy the structure of polymer materials and make plasticizers easier to release; while high-frequency ultrasound can further enhance the contact between solvent and plasticizer and accelerate the diffusion process. Ultrasonic waves of different frequencies may have different mechanisms of action on different types of plasticizers. By using multiple frequencies, the extraction process can be completed more efficiently than ultrasonic extraction with a single frequency. By using multiple frequencies, the characteristics of different materials can be better adapted, thereby achieving a wider range of applicability, and the optimized ultrasonic frequency combination can achieve higher extraction efficiency in a shorter time while reducing the amount of solvent used.

[0045] In some embodiments, the preset working parameters include 3 to 6 ultrasonic frequencies in the ultrasonic frequency band 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). The size of the bubbles generated by different ultrasonic frequencies is different. The bubbles at the frequency f1 in the early stage of ultrasound are large, and the energy generated after rupture is strong, which is suitable for use in the early stage of ultrasound extraction. As the ultrasonic time increases, the sample gradually swells from the outside to the inside. In order to avoid the destruction of the polymer matrix and interfere with the subsequent analysis and testing, it is switched to the frequency f2 with higher frequency and weaker energy for further extraction. As time goes by, the frequencies f3, f4, f5 and f6 are gradually switched for extraction. The internal logic includes automatic heating and cooling startup based on temperature, and ultrasonic extraction according to the frequency and power set by the user, ensuring that the device can operate efficiently and safely under various operating conditions.

[0046] In some embodiments, the preset working parameters include an extraction temperature of 50°C to 65°C; and / or, the preset working parameters include an ultrasonic power of 400w to 1000w; and / or, the preset working parameters include an extraction time of 20min to 40min. For different types of polymer materials, a combination of working times of three or more frequencies is selected to improve the extraction efficiency of restricted substances (PAEs).

[0047] Embodiment 1:

[0048] A custom sequential multi-frequency ultrasonic extraction device was designed with seven transducers in parallel triangular array arranged on the bottom of the titanium alloy cylinder, and a 2-5 mm cylindrical PVC standard sample containing quantitative phthalate plasticizers was placed in the sample tray;

[0049] Mix the sample with 99.9% analytical grade dichloromethane at a solid-liquid ratio of 1 g:25 mL;

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

[0051] Embodiment 2:

[0052] A custom sequential multi-frequency ultrasonic extraction device was designed with seven transducers arranged in parallel in a triangle on the bottom of a stainless steel cylinder. A 2-5 mm cylindrical PVC standard sample containing quantitative phthalate plasticizers was placed in the sample pan.

[0053] Mix the sample with 99.9% analytical grade dichloromethane at a solid-liquid ratio of 1 g:25 mL;

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

[0055] Embodiment 3:

[0056] The self-sequential multi-frequency ultrasonic extraction device is designed with seven transducers arranged in parallel triangles on the bottom of the titanium alloy cylinder. The 2-5 mm cylindrical PU standard sample containing quantitative phthalate plasticizers is placed in the sample tray;

[0057] Mix the sample with 99.9% analytical grade dichloromethane at a solid-liquid ratio of 1 g:25 mL;

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

[0059] Embodiment 4:

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

[0061] Mix the sample with 99.9% analytical grade dichloromethane at a solid-liquid ratio of 1 g:25 mL;

[0062] Multi-frequency ultrasonic extraction was performed according to the preset parameters and sequence: the material temperature was controlled at 50°C ~ 58°C, after the ultrasound was turned on for 3 minutes, f1 (23kHz) 15min, f3 (40kHz) 10min, f4 (58kHz) 5min, f5 (82kHz) 5min were selected, the power was set to 500W, and the total extraction time was 35min.

[0063] Embodiment 5:

[0064] A custom sequential multi-frequency ultrasonic extraction device was designed with six transducers in parallel triangular array arranged on the bottom of the titanium alloy cylinder, and a 2-5 mm cylindrical PVC standard sample containing quantitative phthalate plasticizers was placed in the sample tray;

[0065] Mix the sample with 99.9% analytical grade dichloromethane at a solid-liquid ratio of 1 g:25 mL;

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

[0067] Comparative Example 1:

[0068] A custom sequential multi-frequency ultrasonic extraction device was designed with a transducer on the bottom of the titanium alloy cylinder, and a 2-5 mm cylindrical PVC standard sample containing quantitative phthalate plasticizers was placed in the sample pan;

[0069] Mix the sample with 99.9% analytical grade dichloromethane at a solid-liquid ratio of 1 g:25 mL;

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

[0071] Comparative Example 2:

[0072] A custom sequential multi-frequency ultrasonic extraction device was designed with seven transducers on the bottom of the titanium alloy cylinder, and a 2-5 mm cylindrical PVC standard sample containing quantitative phthalate plasticizers was placed in the sample pan;

[0073] Mix the sample with 99.9% analytical grade dichloromethane at a solid-liquid ratio of 1 g:25 mL;

[0074] Perform multi-frequency ultrasonic extraction according to the preset parameters and sequence: control the extraction environment temperature at 58°C ~ 62°C, turn on the ultrasound for 3 minutes, select f3 (38kHz) for 20 minutes, 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 to 5 and Comparative Examples 1 to 2 are summarized in Table 1. The yield data are obtained by gas chromatography-mass spectrometry analysis, and the integration process involves accurate measurement of chromatographic peaks. The start and end time of each peak is marked, the peak boundary is defined, the peak vertex is determined to obtain the retention time qualitatively, a baseline is established to distinguish the background signal from the target peak, the peak area, peak height and peak width are calculated, and the chromatographic separation effect is quantitatively analyzed and evaluated. The software tools and manual integration adjustment are 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), diethyl phthalate (DEP).

[0076] Table 1.

[0077]

[0078] Please refer to Table 1 and Figure 1 In the ultrasonic extraction process of Example 1, the bubble size generated by the 20-100kHz frequency ultrasound is 397.452μm-66.242μm, which matches the PVC void size. In the early stage of the extraction for 5min, the Brownian motion of the plasticizer molecules is more intense than the large molecular motion, and diffuses to the surface of the product at a higher migration rate to form 1μm-sized holes. As time goes by, at 20min, dichloromethane as an extractant has strong polarity, and contacts deeply with the PVC polymer, destroys the secondary structure of the polymer, enhances the activity of PVC and other molecules, and swells the PVC material. The plasticizer molecules migrate further, and the gaps of the PVC particles appear to be further enlarged. At this time, high-frequency ultrasonic extraction is called to generate micro-sized ultrasonic bubbles to enter the PVC gaps. On the basis of avoiding further damage to the surface of the PVC body, the phthalate plasticizers in the PVC particles are further extracted. When the extraction reaches 40min, the internal plasticizer is almost completely extracted, but there is still a part of the residue. Therefore, a higher frequency ultrasound is selected to generate smaller bubbles to penetrate into the interior of the PVC matrix to achieve a deeper extraction.

[0079] In summary, the customized sequential multi-frequency ultrasonic extraction method provided by the present invention utilizes multiple transducers working in parallel to provide adjustable total power and band frequency, and combines the transducers evenly arranged in the center and around the bottom surface of the cylinder to achieve high-intensity ultrasonic output and enhance the cavitation effect. At the same time, through the simulation optimization of the transducer arrangement, the uniformity of the sound intensity in the cylindrical area with the bottom center as the center is ensured, thereby improving the uniformity of the sound field, so that the final extraction has high accuracy, short time consumption and simple operation.

[0080] Those skilled in the art may combine and associate different embodiments or examples and features of different embodiments or examples described in this specification without mutual contradiction.

[0081] The above description is only a partial or preferred embodiment of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.

Claims

1. A self-defined sequential multi-frequency ultrasonic extraction method, characterized in that: The following steps are involved: Mixing the object to be extracted with the extraction solvent and placing them in a multi-frequency ultrasonic extraction device, wherein the multi-frequency ultrasonic extraction device comprises a plurality of ultrasonic transducers arranged on the bottom surface of an ultrasonic cylinder; The multi-frequency ultrasonic extraction device is turned on and extraction is performed according to preset working parameters. After the extraction is completed, the preset working parameters include a plurality of ultrasonic frequencies that increase in sequence, and the number of the plurality of ultrasonic frequencies is greater than or equal to 3.

2. The self-defined sequential multi-frequency ultrasonic extraction method according to claim 1, characterized in that: The extraction method is used to extract the restricted chemical additives which are combined with the polymer material by physical adsorption to improve the performance of the polymer material.

3. The self-defined sequential multi-frequency ultrasonic extraction method according to claim 2, characterized in that: The polymer material includes one of PVC, PP, PET and PU.

4. The self-defined sequential multi-frequency ultrasonic extraction method according to claim 1, characterized in that: The number of the plurality of ultrasonic transducers is 4 to 8, and any three ultrasonic transducers can form a parallel triangular array arrangement.

5. The self-defined 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.

6. The self-defined sequential multi-frequency ultrasonic extraction method according to claim 5, characterized in that: 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 It is 0.57~0.

75.

7. The self-defined sequential multi-frequency ultrasonic extraction method according to claim 1, characterized in that: The multi-frequency ultrasonic extraction device comprises an ultrasonic cylinder body, the shape of the ultrasonic cylinder body is a cylinder, and the material of the ultrasonic cylinder body is titanium alloy.

8. The self-defined sequential multi-frequency ultrasonic extraction method according to claim 1, characterized in that: The preset working parameters include 3 to 6 ultrasonic frequencies which increase in sequence.

9. The self-defined sequential multi-frequency ultrasonic extraction method according to claim 8, characterized in that: The preset working parameters include 3 to 6 ultrasonic frequencies that increase in sequence in 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).

10. The self-defined sequential multi-frequency ultrasonic extraction method according to claim 1, characterized in that: The preset working parameters include an extraction temperature of 50°C to 65°C; And / or, the preset working parameters include an ultrasonic power of 400w to 1000w; And / or, the preset working parameters include an extraction time of 20 min to 40 min.

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