Temperature-controlled microfluidic device for preparing multiple emulsions

Abstract

The utility model discloses a temperature control microfluidic device for preparing multiple emulsions, which belongs to the technical field of daily chemical products and comprises a raw material container and a microfluidic unit, the raw material container comprises an inner container and an outer container, and the inner container is positioned inside the outer container; the microfluidic unit is formed by assembling two coaxial capillary glass tubes, the two capillary glass tubes are respectively an inner tube and an outer tube, the interior of the inner tube is an inner passage, and the inner passage is communicated with the inner container; an outer passage is arranged between the interior of the outer pipe and the exterior of the inner pipe, the outer passage is communicated with the outer container, and a discharge port of the inner passage is located in the outer passage; a first heat preservation interlayer is arranged outside the raw material container, and a second heat preservation interlayer is arranged outside the micro-fluidic unit. According to the device, stable multiple emulsions are obtained by utilizing the micro-fluidic unit, and the oil-water two-phase container and the micro-fluidic channel are integrated on the micro-fluidic device and are externally attached with the heat-insulating interlayer, so that the constant temperature of the whole emulsification process is ensured, and the problem that the existing micro-fluidic device cannot use solid raw materials is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of daily chemical products, in particular to a temperature-controlled microfluidic device for preparing multiple emulsions. Background Technique

[0002] Multiple emulsions, also known as composite emulsions, are multi-layer emulsions formed by dispersing one type of emulsion (usually called the primary emulsion, abbreviated as the primary milk) in another continuous phase. Generally, they are highly dispersed and multi-phase systems with different particle sizes, and there are various types, with W / O / W (water-in-oil-in-water) and O / W / O (oil-in-water-in-oil) being the two most common types. For example, in the case of a W / O / W type multiple emulsion, its continuous phase is water, and the dispersed phase is oil droplets, but the oil droplets contain dispersed water droplets. Such a multiple emulsion is called a water-in-oil-in-water type multiple emulsion.

[0003] In the daily chemical industry, especially in the cosmetics industry, multiple emulsions have high research value. For example, W / O / W emulsions have excellent skin feel, overcoming the disadvantages of poor moisturizing effect of O / W emulsions and heavy greasiness of W / O emulsions. They can also make water-soluble active substances and oil-soluble active substances exist in the same cosmetic. The multiple structure can make the active substances in the innermost layer be slowly released, prolong the action time of the active ingredients, and achieve a certain controlled release effect.

[0004] Traditional methods for preparing multiple emulsions mostly use ordinary emulsification processes. Taking the preparation method of W / O / W emulsions as an example, the oil and water phases are respectively dissolved in beakers. Under the condition of homogeneous stirring, the water phase is slowly added to the oil phase. A small amount of the water phase is wrapped by a large amount of the oil phase to form a water-in-oil primary emulsion. As the water phase continues to be added, the water phase becomes the outer phase and wraps the water-in-oil primary emulsion to form a water-in-oil-in-water emulsion. The emulsion prepared by this process is only a small-scale optimization of the ordinary emulsion preparation method, relying on less water phase in the early stage, wrapping the water phase with the oil phase to form the primary emulsion. However, this method is affected by conditions such as the type of emulsifier and the addition speed, and cannot precisely control the formation of the water-in-oil primary emulsion. A large number of single emulsions, that is, ordinary water-in-oil emulsions, exist in the prepared multiple emulsions.

[0005] Microfluidic technology is an emerging technology for precisely controlling liquids. It has been applied in the chip field and has not been widely applied in the daily chemical industry. The core of this technology is a small-sized droplet forming device with multiple complex microchannels inside. Using a microfluidic device to prepare multiple emulsions is a new method in recent years.

[0006] The production of multiple emulsions using microfluidic devices, such as the methods described in patents CN102014871A and CN218530969U. However, such devices are generally only prepared at room temperature and cannot be heated, let alone precisely control the emulsification temperature. They can only prepare raw materials that are liquid and have good fluidity at room temperature. In the components of emulsions, fats, emulsifiers, etc. are generally mostly solid raw materials. For example, commonly used cetyl alcohol, stearyl alcohol, paraffin, petrolatum, glyceryl stearate, etc. are all solid raw materials and cannot flow into the microfluidic device. The solid raw materials need to be heated above their melting points to become liquid before participating in the preparation process. The temperature needs to be maintained above the melting point throughout the preparation process, and emulsification cannot be carried out if the heating temperature is too high or too low. If it is too low, the fat is not completely melted, and if it is too high, the fat is prone to oxidation. Therefore, during the emulsion preparation process, it is generally necessary to keep the temperature at a certain level for a period of time to complete the preparation process. For example, in the conventional emulsion preparation process, the oil phase and water phase are kept at 80°C for 30 minutes before emulsification. However, microfluidic devices cannot achieve this function. Summary of the Invention

[0007] In view of the deficiencies of the prior art, the present invention provides a temperature-controlled microfluidic device for preparing multiple emulsions. By using a microfluidic unit, stable multiple emulsions can be obtained. By integrating the oil and water two-phase containers with the microfluidic passage on the microfluidic device and attaching an external heat preservation interlayer, the constant temperature of the entire emulsification process is ensured, so as to solve the problem that existing microfluidic devices cannot use solid raw materials.

[0008] The technical solution of the present invention to solve the above technical problems is as follows:

[0009] A temperature-controlled microfluidic device for preparing multiple emulsions, comprising a raw material container and a microfluidic unit. The raw material container includes an inner container and an outer container, and the inner container is located inside the outer container. The microfluidic unit is composed of two coaxial capillary glass tubes connected together. The two capillary glass tubes are respectively an inner tube and an outer tube. The inside of the inner tube is an inner passage, and the inner passage is communicated with the inner container. The space between the inside of the outer tube and the outside of the inner tube is an outer passage, and the outer passage is communicated with the outer container. The outlet of the inner passage is located inside the outer passage. An outer heat preservation interlayer is provided outside the raw material container, and a second heat preservation interlayer is provided outside the microfluidic unit.

[0010] The beneficial effects of adopting the above technical solution are as follows: the raw materials in the raw material container and the microfluidic unit can be heated at a constant temperature through the first heat preservation interlayer and the second heat preservation interlayer, so that the device can use solid oil to prepare multiple emulsions, ensuring that the whole process of emulsion preparation is above the melting point of the solid oil, and solving the problems that the existing microfluidic devices cannot be heated and kept at a constant temperature during the preparation process. By adding the aqueous phase and the oil phase into the inner container and the outer container respectively, and through the microfluidic unit composed of two coaxial capillary glass tubes, the raw materials discharged from the discharge port of the inner passage are wrapped by the raw materials in the outer passage, and an oil-in-water primary emulsion or a water-in-oil primary emulsion can be formed, and then the next operation can be carried out to generate a water-in-oil-in-water emulsion or an oil-in-water-in-oil emulsion.

[0011] Further, the discharge port of the inner passage is a first conical structure, and the outer passage is a second conical structure at the discharge port of the inner passage.

[0012] The beneficial effects of adopting the above technical solution are as follows: it can reduce the size of the raw materials discharged from the discharge port of the inner passage, which is beneficial for the raw materials in the outer passage to wrap it.

[0013] Further, a discharge pipe is provided at the end of the second conical structure on the outer passage.

[0014] The beneficial effects of adopting the above technical solution are as follows: the discharge pipe is used to discharge the oil-in-water primary emulsion or the water-in-oil primary emulsion.

[0015] Further, the aperture of the discharge pipe on the outer passage is larger than the aperture of the discharge port of the inner passage.

[0016] The beneficial effects of adopting the above technical solution are as follows: it is convenient for the oil-in-water primary emulsion or the water-in-oil primary emulsion to be discharged from the discharge pipe on the outer passage.

[0017] Further, a flow guide is provided on the discharge pipe of the outer passage.

[0018] The beneficial effects of adopting the above technical solution are as follows: it is convenient to introduce the oil-in-water primary emulsion or the water-in-oil primary emulsion into the subsequent container for the next operation.

[0019] Further, a three-hole piston is provided on the microfluidic unit, and the three-hole piston is located at one end of the microfluidic unit connected to the raw material container.

[0020] The beneficial effects of adopting the above technical solution are as follows: the three-hole piston can control the feeding of the raw materials in the raw material container.

[0021] Further, a protective sleeve is provided outside the microfluidic unit, and the second heat preservation interlayer is located outside the protective sleeve.

[0022] The beneficial effects of adopting the above technical solution are as follows: the protective sleeve can protect the capillary glass tubes of the microfluidic unit. Description of the Drawings

[0023] Figure 1 This is a schematic diagram of the overall structure of the present utility model.

[0024] Description of the reference numerals: 1, raw material container; 11, inner container; 12, outer container; 2, microfluidic unit; 21, inner tube; 22, outer tube; 3, inner passage; 4, outer passage; 5, first heat insulation layer; 6, second heat insulation layer; 7, discharge pipe; 8, flow guide device; 9, three-hole piston; 10, protective sleeve; 13, first conical structure; 14, second conical structure. Detailed Description of the Invention

[0025] The principles and features of the present utility model will be described below in conjunction with the Figure 1 drawings. The examples given are only used to explain the present utility model and are not intended to limit the scope of the present utility model.

[0026] An embodiment of the present utility model discloses a temperature-controlled microfluidic device for preparing multiple emulsions.

[0027] Referring to Figure 1 , a temperature-controlled microfluidic device for preparing multiple emulsions includes a raw material container 1 and a microfluidic unit 2. A first heat insulation layer 5 is provided outside the raw material container 1, and a second heat insulation layer 6 is provided outside the microfluidic unit 2. The raw materials in the raw material container 1 and the microfluidic unit 2 can be heated at a constant temperature through the first heat insulation layer 5 and the second heat insulation layer 6 respectively, so that the device can use solid grease to prepare multiple emulsions, and it can ensure that the whole process of emulsion preparation is above the melting point of the solid grease, solving the problems that the existing microfluidic device cannot be heated and kept at a constant temperature during the preparation process.

[0028] The raw material container 1 includes an inner container 11 and an outer container 12, and the inner container 11 is located inside the outer container 12. The microfluidic unit 2 is composed of two coaxial capillary glass tubes connected together, and the two capillary glass tubes are respectively an inner tube 21 and an outer tube 22. The inside of the inner tube 21 is an inner passage 3, and the inner passage 3 is communicated with the inner container 11. The space between the inside of the outer tube 22 and the outside of the inner tube 21 is an outer passage 4, and the outer passage 4 is communicated with the outer container 12. The discharge port of the inner passage 3 is located inside the outer passage 4.

[0029] By adding the aqueous phase and the oil phase into the inner container 11 and the outer container 12 respectively, through the microfluidic unit 2 composed of two coaxial capillary glass tubes joined together, the raw material discharged from the discharge port of the inner passage 3 is wrapped by the raw material in the outer passage 4, and a water-in-oil primary emulsion or an oil-in-water primary emulsion can be formed, and then the next operation can be carried out to generate a water-in-oil-in-water emulsion or an oil-in-water-in-oil emulsion. Specifically, when the aqueous phase is added to the inner container 11 and the oil phase is added to the outer container 12, a water-in-oil primary emulsion can be formed, and a water-in-oil-in-water emulsion can be generated by carrying out subsequent operations; when the oil phase is added to the inner container 11 and the aqueous phase is added to the outer container 12, an oil-in-water primary emulsion can be formed, and an oil-in-water-in-oil emulsion can be generated by carrying out subsequent operations.

[0030] A three-hole piston 9 is installed on the microfluidic unit 2. The three-hole piston 9 is located at one end of the microfluidic unit 2 connected to the raw material container 1, and the three-hole piston 9 is used to control the feeding of the raw material in the raw material container 1.

[0031] A protective sleeve 10 is arranged outside the microfluidic unit 2 to protect the capillary glass tube of the microfluidic unit 2, and the second heat insulation interlayer 6 is located outside the protective sleeve 10.

[0032] The discharge port of the inner passage 3 is a first conical structure 13, and the outer passage 4 is a second conical structure 14 at the discharge port of the inner passage 3 to reduce the size of the raw material discharged from the discharge port of the inner passage 3, which is beneficial for the raw material in the outer passage 4 to wrap it.

[0033] A discharge pipe 7 is arranged at the end of the second conical structure 14 on the outer passage 4 for discharging the water-in-oil primary emulsion or the oil-in-water primary emulsion. The aperture of the discharge pipe 7 on the outer passage 4 is larger than the aperture of the discharge port of the inner passage 3, which is convenient for the water-in-oil primary emulsion or the oil-in-water primary emulsion to be discharged from the discharge pipe 7 on the outer passage 4.

[0034] A flow guide device 8 is arranged on the discharge pipe 7 of the outer passage 4, which is convenient for guiding the water-in-oil primary emulsion or the oil-in-water primary emulsion into the subsequent container for the next operation to generate a water-in-oil-in-water emulsion or an oil-in-water-in-oil emulsion.

[0035] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A temperature-controlled microfluidic device for preparing multiple emulsions, characterized in that: It includes a raw material container (1) and a microfluidic unit (2). The raw material container (1) includes an inner container (11) and an outer container (12), and the inner container (11) is located inside the outer container (12). The microfluidic unit (2) is assembled by connecting two coaxial capillary glass tubes, which are an inner tube (21) and an outer tube (22) respectively. The inside of the inner tube (21) is an inner passage (3), and the inner passage (3) is communicated with the inner container (11). The space between the inside of the outer tube (22) and the outside of the inner tube (21) is an outer passage (4), and the outer passage (4) is communicated with the outer container (12). The outlet of the inner passage (3) is located inside the outer passage (4). A first heat insulation layer (5) is provided outside the raw material container (1), and a second heat insulation layer (6) is provided outside the microfluidic unit (2).

2. The temperature-controlled microfluidic device for preparing multiple emulsions according to claim 1, characterized in that: The outlet of the inner passage (3) is a first conical structure (13), and the outer passage (4) is a second conical structure (14) at the outlet of the inner passage (3).

3. The temperature-controlled microfluidic device for preparing multiple emulsions according to claim 2, wherein: A discharge pipe (7) is provided at the end of the second conical structure (14) on the outer passage (4).

4. The temperature-controlled microfluidic device for preparing multiple emulsions according to claim 3, wherein: The aperture of the discharge pipe (7) on the outer passage (4) is larger than the aperture of the outlet of the inner passage (3).

5. The temperature-controlled microfluidic device for preparing multiple emulsions according to claim 3, characterized in that: A flow deflector (8) is provided on the discharge pipe (7) of the outer passage (4).

6. The temperature-controlled microfluidic device for preparing multiple emulsions according to claim 1, wherein: A three-hole piston (9) is provided on the microfluidic unit (2), and the three-hole piston (9) is located at one end of the microfluidic unit (2) connected to the raw material container (1).

7. The temperature-controlled microfluidic device for preparing multiple emulsions according to claim 1, characterized in that: A protective sleeve (10) is provided outside the microfluidic unit (2), and the second heat insulation layer (6) is located outside the protective sleeve (10).

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