Oil core microcapsule preparation device and drop formation method

Abstract

The application discloses an oil core microcapsule preparation device and a drop forming method, wherein the oil core microcapsule preparation device comprises a drop head module, a vibration element, an oil phase channel, an aqueous phase channel, a cooling phase channel, a cooling forming pipe, a collection box and a cooling box; the drop head module comprises an oil phase inlet, an aqueous phase inlet, a cooling phase inlet, an oil phase drop head, an aqueous phase drop head, a cooling phase shunt and a cooling liquid outlet; the vibration element comprises a reciprocating motor, an eccentric shaft connecting rod, and the lower end of the eccentric shaft connecting rod is above the oil phase channel; the upper end of the cooling forming pipe is connected with the outlet, and the lower end extends into the collection box; and the cooling box is arranged below the collection box. The application is favorable for improving the preparation speed and stability of the oil core microcapsule, the size uniformity of the oil core microcapsule, and effectively improving the quality of the oil core microcapsule product.

Description

Technical Field

[0001] This invention relates to the field of microcapsule preparation technology, and in particular to an apparatus for preparing oil core microcapsules and a drop-forming method. Background Technology

[0002] Microcapsules with a core-shell structure can be loaded with a variety of target substances. By encapsulating the target substances within the shell, they are protected from the influence of the external environment and can achieve controlled release of the target substances. Therefore, they are widely used in the fields of pharmaceuticals, health products, food, cosmetics and other biological products.

[0003] Currently, there are many methods for preparing oil-core microcapsules. Different methods can be used for large-scale emulsion production or to produce monodisperse oil-core microcapsules. Traditional methods for preparing microcapsules are continuous processes, using mechanical stirring to force the multiphase mixture to be rapidly sheared and refined into a homogeneous and stable emulsion system. However, traditional methods lack precise control over the fluid, and the monodispersity of the prepared emulsion needs further improvement. It is evident that traditional methods have poor precision control over the fluid, resulting in low controllability of the basic properties of microcapsules, especially their size, mechanical properties, and release characteristics, even under the same operating conditions.

[0004] Microfluidics, as an emerging method for solving fluid controllability problems, has been used to prepare microcapsules from various materials. Common microfluidic devices include flow-focusing microchannels and T-channels. Existing oil-core microcapsule preparation devices often rely on the internal phase's gravity to overcome the surface tension of the intermediate phase and detach into droplets. This results in slow dispersion, uneven oil core size in the microcapsules, and poor overall preparation efficiency. Furthermore, some microfluidic devices only have one inlet for coolant, leading to unstable coolant flow at the droplet tip, which also affects droplet formation.

[0005] Therefore, there is a need to design an oil core microcapsule preparation device that can prepare oil core microcapsules faster and more stably, while producing oil core microcapsule products with good stability. Summary of the Invention

[0006] The purpose of this invention is to provide an oil core microcapsule preparation apparatus and a drop forming method. By setting a cooling phase distributor to make the cooling phase flow uniformly, and by setting a vibration element to control the oil phase liquid to fall off into droplets by squeezing the oil phase channel, oil core microcapsules can be produced more stably and uniformly. This solves the problems of low efficiency in microcapsule preparation, uneven size of the obtained microcapsule oil cores, and the impact on product quality.

[0007] To solve the above technical problems, the present invention is achieved through the following technical solution:

[0008] The present invention first provides an oil core microcapsule preparation device, including a dropper module, a vibration element, an oil phase channel, an aqueous phase channel, a cooling phase channel, a cooling forming tube, a collection box, and a cooling box;

[0009] The input end of the oil phase channel is connected to an external oil phase feeding device, and the output end of the oil phase channel is connected to the dripper module; a heating belt is provided on the water phase channel, the input end of the water phase channel is connected to an external water phase feeding device, and the output end of the water phase channel is connected to the dripper module; the input end of the cooling phase channel is connected to an external cooling phase feeding device, and the output end of the cooling phase channel is connected to the dripper module.

[0010] The dropper module is used to mix the oil phase, water phase, and cooling phase to form oil-in-water microcapsules; the vibration element is set on the oil phase channel to vibrate the oil phase channel, so that the oil phase is in droplet form when it mixes with the water phase in the dropper module; one end of the cooling forming tube is set at the outlet of the dropper module, and the other end extends into the inside of the collection box; the collection box is set inside the cooling box, and the cooling box is filled with coolant.

[0011] As a preferred embodiment of the present invention, the dripper module includes an oil phase inlet, a water phase inlet, a cooling phase inlet, a dripper, and a combined outlet; the oil phase inlet is connected to the oil phase channel, the water phase inlet is connected to the water phase channel, and the cooling phase inlet is connected to the cooling phase channel.

[0012] The dripper includes an oil phase dripper, an aqueous phase dripper, and a cooling phase dripper arranged sequentially from the inside out. The oil phase enters the oil phase dripper through the oil phase inlet, the aqueous phase enters the aqueous phase dripper through the aqueous phase inlet, and the cooling phase enters the cooling phase dripper through the cooling phase inlet. The outlet end of the aqueous phase dripper extends beyond the outlet end of the oil phase dripper, and the outlet end of the outward-facing dripper is connected to the integrated outlet.

[0013] As a preferred embodiment of the present invention, the cooling phase inlet is configured as a convective liquid inlet, and the cooling phase liquid flows downward in the flow channel between the water phase dripper and the cooling phase dripper; a cooling phase distributor is also provided in the flow channel between the water phase dripper and the cooling phase dripper, the cooling phase distributor is sleeved on the middle section outside the water phase dripper, an even number of cooling phase flow ports are uniformly provided on the circumference of the cooling phase distributor, and the transition between the cooling phase flow ports and the edge of the cooling phase distributor is arc-shaped.

[0014] As a preferred embodiment of the present invention, the vibration element includes a reciprocating motor and an eccentric wheel shaft connecting rod. The reciprocating motor is speed-regulated by a speed regulator. One end of the eccentric wheel shaft connecting rod is connected to the shaft of the reciprocating motor, and the other end of the eccentric wheel shaft connecting rod is disposed on the oil phase channel. When the reciprocating motor is operating, the eccentric wheel shaft connecting rod performs reciprocating motion, thereby causing the oil phase channel to vibrate.

[0015] The present invention also provides a method for drop-forming oil core microcapsules using the above-mentioned oil core microcapsule preparation apparatus, comprising the following steps:

[0016] 1) Add the prepared oil phase, water phase and cooling phase to the external oil phase feeder, external water phase feeder and external cooling phase feeder respectively;

[0017] 2) The oil phase, water phase, and cooling phase are respectively transported to the oil phase inlet, water phase inlet, and cooling phase inlet of the dripper module through the oil phase channel, water phase channel, and cooling phase channel.

[0018] 3) Turn on the switch of the vibration element. The vibration element vibrates the oil phase channel, so that when the oil phase meets the water phase in the dripper module (1), it forms an oil core microcapsule in the form of oil in water. The oil core microcapsule falls into the cooling phase under the action of gravity and enters the cooling forming tube through the integrated outlet together with the cooling phase.

[0019] 4) The oil-core microcapsules are cooled during the flow process in the cooling forming tube and then flow into the collection box;

[0020] 5) The cooling water in the cooling box further cools and solidifies the oil core microcapsules in the collection box.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] The present invention discloses an oil core microcapsule preparation device and a drop forming method. Unlike the cooling liquid feeding method with only one side inlet, the cooling liquid feeding method of the present invention is convective feeding, and a cooling phase distributor is set to make the cooling phase flow and dispersion more uniform. A heating belt is set in the aqueous phase channel to ensure the continuity of the aqueous phase flow, which is beneficial to the uniform and stable preparation of microcapsules at the droplet.

[0023] Meanwhile, a vibration element is set above the oil phase channel to create instability in the fluid. By squeezing the pipe, the formation of microcapsules at the drip head is accelerated, and the droplets encapsulating the oil core are controlled to fall. This helps to improve the size uniformity of the oil core and oil phase. Microcapsules can be prepared at a certain frequency, which helps to improve the size uniformity of the oil core and oil phase, and effectively improves the quality stability of the microcapsule products. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the oil core microcapsule preparation device of the present invention;

[0025] Figure 2 This is a schematic diagram of the dripping head module in this invention;

[0026] Figure 3 This is a schematic diagram of the cooling phase splitter in this invention. Detailed Implementation

[0027] The present invention will be further described and illustrated below with reference to specific embodiments. The embodiments described are merely examples of the content of this disclosure and do not limit the scope of the invention. The technical features of each embodiment in the present invention can be combined accordingly, provided that there is no mutual conflict.

[0028] like Figure 1 As shown, the present invention provides an oil core microcapsule preparation device, including a dropper module 1, a vibration element 2, an oil phase channel 3, an aqueous phase channel 4, a cooling phase channel 5, a cooling forming tube 6, a collection box 7, and a cooling box 8. An external oil phase feeding device is connected to the input end of the oil phase channel 3, and the output end is connected to the oil phase inlet 101 of the dropper module. An external aqueous phase feeding device is connected to the input end of the aqueous phase channel 4, and the output end is connected to the aqueous phase inlet 102 of the dropper module. An external cooling phase feeding device is connected to the input end of the cooling phase channel 5, and the output end is connected to the cooling phase inlet 103 of the dropper module. The vibration element 2 includes a reciprocating motor and an eccentric wheel shaft connecting rod. The lower end of the eccentric wheel shaft connecting rod is positioned above the oil phase channel 3. The upper end of the cooling forming tube 6 is connected to the integrated outlet 104 of the dropper module, and the lower end of the cooling forming tube 6 extends into the collection box 7. The collection box 7 is placed in the cooling box 8.

[0029] like Figure 2 As shown, the dripper module 1 includes an oil phase inlet 101, a water phase inlet 102, a cooling phase inlet 103, an oil phase dripper 105, a water phase dripper 106, a cooling phase distributor 107, a cooling phase dripper 108, and a combined outlet 104. The oil phase dripper 105 and the water phase dripper 106 are coaxial, with the oil phase dripper 105 recessed within the water phase dripper 106. The outlet end of the cooling phase dripper 108 is connected to the combined outlet 104. The oil phase dripper 105 has a diameter of 0.7-2 mm and a wall thickness of 0.2-0.4 mm, the water phase dripper 106 has a diameter of 2-4 mm and a wall thickness of 0.2-0.4 mm, the oil phase inlet 101 has a diameter of 0.7-5 mm, the water phase inlet 102 has a diameter of 2-5 mm and a wall thickness of 0.5-2 mm, and the cooling phase inlet 103 has a diameter of 3-8 mm and a wall thickness of 0.5-2 mm.

[0030] The cooling phase inlet 103 is configured for convective liquid inlet, where the cooling phase liquid flows downwards from the outside of the aqueous phase dripper 106. After passing through the cooling phase distributor 107, it is further evenly distributed to the surrounding area by the cooling phase distributor 107, improving the flow stability of the cooling phase liquid at the aqueous phase dripper 106 and facilitating the stable formation of the oil core microcapsules 9. Figure 3As shown, the cooling phase distributor 107 is fitted in the middle section outside the water phase dripper 106, and its inner wall is cut into the water phase dripper 106. An even number of cooling phase flow ports are evenly provided on the circumference of the cooling phase distributor 107. The transition between the cooling phase flow port and the edge of the cooling phase distributor is arc-shaped. The outlet 104 has an inner diameter of 8-10 mm and a wall thickness of 2-5 mm.

[0031] The reciprocating motor of the vibration element 2 can be speed-regulated by a speed controller, with a speed of 1r / s-200r / s. The eccentric wheel shaft connecting rod is set on the oil phase channel 3. During operation, the eccentric wheel shaft connecting rod reciprocates and squeezes the oil phase channel 3 with an amplitude of 1-2mm.

[0032] In one specific embodiment of the present invention, the input end of the oil phase channel 3 is connected to an external oil phase feeding device, and the output end is connected to the oil phase inlet 101 of the dripper module. The oil phase channel 3 is a 0.7-5mm silicone hose with a length of 40cm-500cm. The input end of the aqueous phase channel 4 is connected to an external aqueous phase feeding device, and the output end is connected to the aqueous phase inlet 102 of the dripper module. The aqueous phase channel 4 is a 2-5mm silicone hose with a length of 40cm-500cm. The input end of the cooling phase channel 5 is connected to an external cooling phase feeding device, and the output end is connected to the cooling phase inlet 103 of the dripper module. The cooling phase channel 5 is a 3-8mm silicone hose with a length of 40cm-500cm. The cooling and forming tube 6 has an inner diameter of 10-15mm, a wall thickness of 2-5mm, and a length of 100-1000cm. The upper end is connected to the integrated outlet 104 of the dripping module, and the lower end extends into the collection box 7. The collection box 7 is placed in the cooling box 8, which is pre-filled with 4-6℃ ice water, covering half the height of the collection box.

[0033] The present invention also provides a drop-forming method based on the above-mentioned oil core microcapsule preparation device, comprising the following steps:

[0034] 1) Prepare the relevant solutions. For the oil-in-water system, choose gelatin solution as the aqueous phase, linseed oil as the oil phase, and liquid paraffin oil as the cooling phase.

[0035] 2) Using an external feeding device, the oil phase, water phase and cooling phase are uniformly and stably transported to the oil phase inlet 101, water phase inlet 102 and cooling phase inlet 103 of the dripper module through the oil phase channel 3, water phase channel 4 and cooling phase channel 5. The oil phase flow rate is 10-800 μL / min, the water phase flow rate is 100-2000 μL / min and the cooling phase flow rate is 10-1000 mL / min.

[0036] 3) Turn on the switch of the vibration element 2 to make the eccentric wheel shaft connecting rod reciprocate to squeeze the oil phase channel 3, so that the oil phase liquid is squeezed out of the oil phase dropper 105 at a certain frequency, the frequency being 1-120Hz, and water-in-oil microcapsules 9 are formed at the water phase dropper 106. The size of the microcapsules is 1-5mm. When the cooling phase flows into the cooling phase distributor 107, it is evenly dispersed, so that the cooling phase flows stably at the water phase dropper 106. The microcapsules 9 fall into the cooling phase at the water phase dropper 106 under the action of gravity, and after being cooled for a certain time by the cooling forming tube 6, they flow into the collection box 7.

[0037] 4) Place 4-6℃ ice water in the cooling box 8 in advance to further cool and solidify the microcapsules 9 in the collection box 7.

[0038] Example 1

[0039] 1) Prepare the relevant solutions. For the oil-in-water system, select 25% gelatin solution as the aqueous phase, linseed oil as the oil phase, and liquid paraffin oil as the cooling phase.

[0040] 2) Using an external feeding device, the oil phase, water phase and cooling phase are uniformly and stably transported to the oil phase inlet, water phase inlet and cooling phase inlet of the dripper module through the oil phase channel, water phase channel and cooling phase channel. The oil phase flow rate is 100 μL / min, the water phase flow rate is 600 μL / min and the cooling phase flow rate is 20 mL / min.

[0041] 3) Turn on the switch of the vibration element to make the eccentric wheel shaft connecting rod reciprocate to squeeze the oil phase channel, so that the oil phase liquid is squeezed out of the oil phase dropper at a certain frequency of 1Hz and 1mm amplitude, forming water-in-oil microcapsules at the water phase dropper. The size of the microcapsules is 2-3.5mm. When the cooling phase flows into the cooling phase distributor, it is evenly dispersed, so that the cooling phase flows stably at the water phase dropper. The microcapsules fall into the cooling phase at the water phase dropper under the action of gravity, and after being cooled for a certain period of time by the cooling forming tube, they flow into the collection box.

[0042] 4) Place 6°C ice water in the cooling box in advance to further cool and solidify the microcapsules in the collection box.

[0043] Example 2

[0044] 1) Prepare the relevant solutions. For the oil-in-water system, select 28% gelatin solution as the aqueous phase, linseed oil as the oil phase, and liquid paraffin oil as the cooling phase.

[0045] 2) Using an external feeding device, the oil phase, water phase and cooling phase are uniformly and stably transported to the oil phase inlet, water phase inlet and cooling phase inlet of the dripper module through the oil phase channel, water phase channel and cooling phase channel. The oil phase flow rate is 200 μL / min, the water phase flow rate is 800 μL / min and the cooling phase flow rate is 10 mL / min.

[0046] 3) Turn on the switch of the vibration element to make the eccentric wheel shaft connecting rod reciprocate to squeeze the oil phase channel, so that the oil phase liquid is squeezed out of the oil phase dropper at a certain frequency. The frequency is 100Hz and the amplitude is 1.1mm. Water-in-oil microcapsules are formed at the water phase dropper. The size of the microcapsules is 3-3.8mm. When the cooling phase flows into the distributor, it is evenly dispersed, so that the cooling phase flows stably at the water phase dropper. The microcapsules fall into the cooling phase at the water phase dropper under the action of gravity. After being cooled for a certain period of time by the cooling forming tube, they flow into the collection box.

[0047] 4) Place 4°C ice water in the cooling box in advance to further cool and solidify the microcapsules in the collection box.

[0048] Comparative Example 1

[0049] Compared with Example 1, the difference is that no vibration element is provided at the oil phase channel.

[0050] Comparative Example 2

[0051] Compared with Example 1, the difference is that no splitter is provided.

[0052] Comparative Example 3

[0053] Oil core microcapsules were prepared using a coaxial, flow-focusing capillary glass tube device. The solution used was the same as in Example 1. The inner diameters of the oil and water phase capillaries were the same as those of the oil and water phase droppers of this invention. The flow rates of the oil, water, and cooling phases were the same as in Example 1.

[0054] Example 1

[0055] To evaluate the differences between the examples and comparative examples, the preparation processes and microcapsules obtained in Examples 1-2 and Comparative Examples 1-3 were evaluated. The relevant evaluation results are shown in Table 1.

[0056]

[0057] Therefore, the oil core microcapsule preparation device of the present invention can prepare oil core microcapsules more stably, and the microcapsules prepared are more uniform in both oil core size and microcapsule size compared with comparative examples 1-3.

[0058] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. Those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. An oil core microcapsule production apparatus characterized by comprising: It includes a dripper module (1), a vibration element (2), an oil phase channel (3), a water phase channel (4), a cooling phase channel (5), a cooling forming tube (6), a collection box (7), and a cooling box (8); The input end of the oil phase channel (3) is connected to an external oil phase feeding device, and the output end of the oil phase channel (3) is connected to the dripper module (1); the vibration element (2) includes a reciprocating motor and an eccentric wheel shaft connecting rod. One end of the eccentric wheel shaft connecting rod is connected to the shaft of the reciprocating motor, and the other end of the eccentric wheel shaft connecting rod is set on the oil phase channel. When the reciprocating motor operates, the eccentric wheel shaft connecting rod moves back and forth, thereby causing the oil phase channel to vibrate; a heating belt is provided on the water phase channel (4). The input end of the water phase channel (4) is connected to an external water phase feeding device, and the output end of the water phase channel (4) is connected to the dripper module (1); the input end of the cooling phase channel (5) is connected to an external cooling phase feeding device, and the output end of the cooling phase channel (5) is connected to the dripper module (1); The dripper module (1) includes an oil phase inlet (101), a water phase inlet (102), a cooling phase inlet (103), drippers, and a comprehensive outlet (104); the oil phase inlet (101) is connected to the oil phase channel (3), the water phase inlet (102) is connected to the water phase channel (4), and the cooling phase inlet (103) is connected to the cooling phase channel (5); the dripper includes an oil phase dripper (105), a water phase dripper (106), and a cooling phase dripper (108) arranged sequentially from the inside to the outside; the oil phase enters the oil phase dripper (105) through the oil phase inlet (101), the water phase enters the water phase dripper (106) through the water phase inlet (102), and the cooling phase enters the cooling phase dripper (108) through the cooling phase inlet (103); the outlet end of the water phase dripper (106) is located in front of the outlet end of the oil phase dripper (105), and the outlet end of the cooling phase dripper (108) is connected to the comprehensive outlet (104); The diameter of the oil phase dropper (105) is 0.7-2 mm; the diameter of the aqueous phase dropper (106) is 2-4 mm, and the outlet end of the aqueous phase dropper (106) is located 0.5-2 mm in front of the outlet end of the oil phase dropper (105). The cooling phase inlet is configured as a convective liquid inlet, and the cooling phase flows downward in the channel between the water phase dripper (106) and the cooling phase dripper (108); a cooling phase distributor (107) is also provided in the channel between the water phase dripper (106) and the cooling phase dripper (108). The cooling phase distributor (107) is sleeved on the middle section outside the water phase dripper (106). An even number of cooling phase flow ports are evenly provided on the circumference of the cooling phase distributor (107), and the transition between the cooling phase flow ports and the edge of the cooling phase distributor is arc-shaped. One end of the cooling forming tube (6) is located at the outlet of the dripping module (1), and the other end extends into the inside of the collection box (7); the collection box (7) is located inside the cooling box (8), and ice water is added to the cooling box (8).

2. The oil core microcapsule preparation apparatus according to claim 1, characterized in that, The inner diameter of the oil phase channel is 0.7-5mm; the inner diameter of the cooling forming tube is 10-15mm, and the length is 100-1000cm.

3. A method for drop-forming oil core microcapsules using the oil core microcapsule preparation apparatus of claim 1, characterized in that, Includes the following steps: 1) Add the prepared oil phase, water phase and cooling phase to the external oil phase feeder, external water phase feeder and external cooling phase feeder respectively; The aqueous phase prepared in step 1) is a deionized aqueous solution of one of gelatin, gum arabic, pectin, gellan gum, carrageenan, agar, xanthan gum, guar gum, agarose, and sodium alginate with a volume concentration of 20-40%; the oil phase is a hydrophobic oil that is liquid at room temperature; and the cooling phase is liquid paraffin oil. 2) The oil phase, water phase and cooling phase are respectively transported to the oil phase inlet (101), water phase inlet (102) and cooling phase inlet (103) of the dripper module through the oil phase channel (3), water phase channel (4) and cooling phase channel (5). 3) Turn on the switch of the vibration element (2), and the reciprocating motor starts to operate. When the reciprocating motor operates, the eccentric wheel shaft connecting rod moves back and forth and drives the oil phase channel to start vibrating, so that when the oil phase and the water phase meet in the dripper module (1), an oil core microcapsule in the form of water-in-oil is formed. The oil core microcapsule falls into the cooling phase under the action of gravity and enters the cooling forming tube (6) through the integrated outlet (104) together with the cooling phase. 4) The oil core microcapsules are cooled during the flow process in the cooling forming tube (6) and then flow into the collection box (7); 5) The ice water in the cooling box (8) further cools and shapes the oil core microcapsules in the collection box (7).

4. The method for forming oil-core microcapsules according to claim 3, characterized in that, The flow rate of the oil phase in the oil phase channel is 10-800 μL / min, the flow rate of the water phase in the water phase channel is 100-2000 μL / min, and the flow rate of the cooling phase in the cooling phase channel is 10-1000 mL / min.

5. The method for forming oil-core microcapsules by dropping according to claim 3, characterized in that, Glycerin is also added to the aqueous phase, and the volume concentration of glycerin in the aqueous phase is 5-12%.

6. The method for forming oil-core microcapsules by dropping according to claim 3, characterized in that, In step 3), the reciprocating motor operates at a frequency of 1-120Hz and an amplitude of 1-2mm.

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