Preparation method of acrylate-based wall material microcapsule based on micro-fluidic double-emulsification technology

Abstract

The invention belongs to the technical field of microcapsule preparation, and particularly relates to a preparation method of an acrylate-based wall material microcapsule based on a micro-fluidic double-emulsification technology. The invention provides a glass capillary micro-fluidic platform. The glass capillary micro-fluidic platform comprises a micro-injection system and a glass capillary chip, and the glass capillary chip is connected with the micro-injection system through a conduit. And the microcapsules prepared by using the platform and a method of combining a photocuring material are uniform in size, relatively good in encapsulation performance and rapid in mass preparation.

Description

Technical Field

[0001] The invention belongs to the technical field of microcapsule preparation, and more specifically relates to a method for preparing acrylate-based wall material microcapsules based on microfluidic double emulsification technology. Background Art

[0002] The preparation methods of microcapsules are divided into physical method, chemical method and physicochemical method. However, the particle size of microcapsules prepared by the methods provided in the prior art is not uniform and it is easy to cause waste of materials. Therefore, how to prepare microcapsules with uniform and controllable size has become a difficult problem that technicians in this field need to overcome urgently.

[0003] Microfluidics is a discipline that systematically and precisely manipulates microfluids at scales of tens to hundreds of microns. Microfluidics emerged in the early 1990s, with the initial purpose of simply meeting the needs of miniaturization, microquantification, convenience and efficiency in the fields of biology and chemistry. Later, due to its increasingly prominent advantages, it gradually developed into a discipline with cross-applications in multiple fields. At the same time, a series of terms such as "chip lab" and "micro-microfluidic chip" also emerged. On this basis, how to further reduce the amount of reagents and shorten the time process has always been the driving force for the development of microfluidics. Droplet microfluidics is a branch of microfluidics technology that emerged in this context. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing acrylate-based wall material microcapsules based on microfluidic double emulsification technology to solve the problems existing in the above-mentioned prior art and realize the preparation of acrylate-based wall material microcapsules with uniform size.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention: a capillary microfluidic platform, the capillary microfluidic platform comprises a microinjection system and a capillary chip;

[0007] The microinjection system includes three microinjection pumps and three syringes;

[0008] The capillary chip comprises a coaxially arranged A tube, a B tube and a C tube;

[0009] Wherein, the A tube and the B tube are arranged relative to each other; the C tube is sleeved outside the A tube and the B tube;

[0010] One end of the A tube, the connection between the A tube and the C tube, and the connection between the B tube and the C tube are respectively provided with an injection port A, an injection port B, and an injection port C;

[0011] The injection port A, the injection port B and the injection port C are respectively connected to three syringes in the microinjection system which are respectively controlled by three microinjection pumps.

[0012] Furthermore, the A tube is obtained by drawing a fine glass capillary with ID 0.8mm / OD 1.0mm (inner diameter 0.8mm / outer diameter 1.0mm) into a cone shape, wherein the cone end diameter of the A tube is 200 μm and the length is 3.2-3.5 cm.

[0013] Furthermore, the B tube is obtained by drawing a fine glass capillary with ID 0.8mm / OD 1.0mm into a cone shape, wherein the cone end diameter of the B tube is 500 μm and the length is 3.7-4.0 cm.

[0014] Furthermore, the C tube is a thick glass capillary tube with ID 1.05mm / OD 1.15mm and a length of 3.2-3.5cm.

[0015] Furthermore, the A tube is subjected to hydrophobic treatment.

[0016] Optionally, the hydrophobic treatment is performed by soaking in 5 vol% octadecyltrichlorosilane (OTS) acetylacetone solution for 8 hours.

[0017] Furthermore, the B tube and the C tube are subjected to hydrophilic treatment.

[0018] Optionally, the hydrophilic treatment is performed by soaking in a 5 vol% 3-APTES (3-aminopropyltriethoxysilane) ethanol solution for 8 hours.

[0019] Tubes A, B and C are coaxially arranged to form an injection tube, a collection tube and an outer sleeve. AB type epoxy resin is used to fix the glass capillary on a glass slide, and epoxy resin is also used to fix the flat-mouth needle to the three-phase channel port.

[0020] The second technical solution of the present invention is to provide a method for preparing acrylate-based wall material microcapsules based on microfluidic double emulsion technology, which is prepared using the above-mentioned capillary microfluidic platform, and the steps include:

[0021] The inner phase fluid is injected from the channel port at one end of tube A, the middle phase fluid is injected from the channel port at the connection between tube A and tube C, and the outer phase fluid is injected from the channel port at the connection between tube B and tube C to form double emulsion droplets of uniform size, which are cured by ultraviolet light to form acrylate-based wall material microcapsules;

[0022] The internal phase fluid consists of water and PVA;

[0023] The intermediate phase fluid is composed of methacryloxypropyl tris(trimethylsiloxy)silane, trimethylolpropane trimethacrylate and 2-hydroxy-2-methylpropiophenone;

[0024] The external phase fluid consists of water and PVA.

[0025] Furthermore, the ratio of water to PVA in the internal phase fluid is 50 mL:2.5 g.

[0026] Furthermore, the volume ratio of methacryloxypropyl tris(trimethylsiloxy)silane, trimethylolpropane trimethacrylate and 2-hydroxy-2-methylpropiophenone in the intermediate phase fluid is 0.7:3.5:0.8.

[0027] Furthermore, the ratio of water to PVA in the external phase fluid is 100 mL:5 g.

[0028] Furthermore, the flow rate of the inner phase fluid is 1.2-1.5 mL / h.

[0029] Optionally, the flow rate of the inner phase fluid is 1.5 mL / h.

[0030] Furthermore, the flow rate of the intermediate phase fluid is 0.7-1.0 mL / h.

[0031] Optionally, the flow rate of the intermediate phase fluid is 0.7 mL / h.

[0032] Furthermore, the flow rate of the external phase fluid is 5-7 mL / h.

[0033] Optionally, the flow rate of the external phase fluid is 7 mL / h.

[0034] The invention can control the particle size and shell thickness of the microcapsule by adjusting the flow rate.

[0035] Furthermore, the wavelength of the ultraviolet light in the ultraviolet light curing is 365nm, provided by a 7-25W ultraviolet lamp, and the curing time is 5-10s.

[0036] In the present invention, the inner phase fluid is introduced from the A tube, cut into a jet by the middle phase fluid, and then formed into double emulsion droplets of uniform size under the shearing action of the outer phase fluid. Subsequently, the double emulsion droplets (W / O / W type) are irradiated by an ultraviolet lamp in the collecting tube channel. Under the irradiation of ultraviolet light, the middle phase fluid undergoes a cross-linking reaction under the action of an ultraviolet light initiator 2-hydroxy-2-methylpropiophenone, solidifies to form an outer shell, and embeds the inner phase fluid to form a microcapsule.

[0037] The third technical solution of the present invention is to provide an acrylate-based wall material microcapsule with uniform size, which is prepared by the above preparation method.

[0038] The present invention adopts microfluidic technology to prepare microcapsules with thinner shell chemical structure, wherein the microcapsules have an adjustable structure and the overall size of the microcapsules can be changed by adjusting the three-phase flow rate. At the same time, acrylate-based materials provide guidance for the research of microcapsule wall materials.

[0039] The present invention discloses the following technical effects:

[0040] The microcapsules prepared by the method of combining a microfluidic chip with a photocurable material have uniform size, good encapsulation performance and can be prepared quickly and in large quantities.

[0041] The invention uses methacryloxypropyl tris(trimethylsiloxy)silane, trimethylolpropane trimethacrylate and 2-hydroxy-2-methylpropiophenone to form an intermediate phase fluid as a microcapsule wall material to prepare microcapsules with uniform sizes.

[0042] The present invention adopts glass capillary chip combined with light curing to prepare microcapsules, and the overall size and shell thickness of the microcapsules can be adjusted.

[0043] The present invention provides new ideas and technical support for the development of new functional microcapsule materials, especially in the field of microcapsule shell curing, and is expected to bring significant technological progress and practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0045] Figure 1 Schematic diagram of glass capillary microfluidic platform device;

[0046] Figure 2 Schematic diagram of the relative positions of tube A, tube B, tube C and injection port A to injection port C;

[0047] Figure 3 Schematic diagram of glass capillary microfluidic chip;

[0048] Figure 4 This is a physical picture of the glass capillary microfluidic chip;

[0049] Figure 5 This is a diagram of the internal structure of the glass capillary microfluidic chip and the droplet generation diagram;

[0050] Figure 6 This is a physical picture of the acrylic ester-based wall material microcapsule prepared in Example 1;

[0051] Figure 7 This is a microscope photo of the acrylic ester-based wall material microcapsules prepared in Example 1;

[0052] Figure 8 The SEM images of the acrylic ester-based wall material microcapsules prepared in Example 1 at different magnifications, wherein a is 50 times and b is 1000 times;

[0053] Fig. 9 These are microscope photos of acrylate-based wall material microcapsules prepared in Examples 1-4, wherein a is Example 1, b is Example 2, c is Example 3, and d is Example 4. DETAILED DESCRIPTION

[0054] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0055] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0056] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0057] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0058] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0059] The raw materials, reagents and devices used in the specific embodiments of the present invention are all commercially available products.

[0060] Figure 1 Schematic diagram of the capillary microfluidic platform device.

[0061] Figure 2 This is a schematic diagram of the relative positions of tube A, tube B, tube C and injection port A to injection port C.

[0062] Figure 3 Schematic diagram of the capillary microfluidic chip.

[0063] Figure 4 This is a physical picture of the capillary microfluidic chip.

[0064] Figure 5 This is a diagram of the internal structure of the capillary microfluidic chip and the droplet generation diagram.

[0065] Example 1

[0066] The preparation method of acrylate-based wall material microcapsules based on microfluidic double emulsification technology comprises the following steps:

[0067] S1. Construction of capillary microfluidic chip

[0068] (1) Use a tube puller to pull a thin glass capillary with an ID of 0.8 mm and an OD of 1.0 mm into a tapered end, and cut the tapered end to obtain tube A and tube B; the size of tube A is 200 μm × 3.4 cm (diameter of the tapered end × overall length of the glass capillary); the size of tube B is 500 μm × 4.0 cm (diameter of the tapered end × overall length of the glass capillary); cut a thick glass capillary with an ID of 1.05 mm and an OD of 1.15 mm to a length of 3.5 cm as tube C.

[0069] (2) Use a 5 vol% octadecyltrichlorosilane (OTS) acetylacetone solution to soak tube A for 8 h for hydrophobic treatment; use a 5 vol% 3-APTES (3-aminopropyltriethoxysilane) ethanol solution to soak tubes B and C for 8 h for hydrophilic treatment.

[0070] (3) Tube A and tube B are arranged relative to each other and are inserted into tube C. Tube A, tube B and tube C are coaxially arranged to form an injection tube, a collection tube and an outer sleeve. They are fixed on a glass slide using AB type epoxy resin and then a flat-mouth needle is fixed to the three-phase channel port to complete the construction of the capillary microfluidic chip. The three channel ports are located at one end of tube A, the connection between tube A and tube C, and the connection between tube B and tube C.

[0071] S2. Construction of capillary microfluidic platform

[0072] A microsyringe pump (XMSP-C Ximai Intelligent Syringe Pump) was used to precisely control and push the syringes (three), which were connected to the plain needles using Teflon catheter connections.

[0073] S3. Preparation of raw materials

[0074] (1) Internal phase fluid: Take 50 mL of up water into a beaker, add 2.5 g of PVA in small amounts and repeatedly with heating and stirring in the up water (70°C, 1500 rpm, 3 h) until it is completely dissolved to obtain the internal phase fluid.

[0075] (2) Intermediate phase fluid: Take 0.7 mL of methacryloyloxypropyl tris(trimethylsiloxy)silane, 3.5 mL of trimethylolpropane trimethacrylate, and 0.8 mL of 2-hydroxy-2-methylpropiophenone, and shake them for 5 min until they are completely blended to obtain an intermediate phase fluid.

[0076] (3) External phase fluid: Take 100 mL up water and 5.0 g PVA to prepare a 5 wt % PVA solution as the external phase fluid.

[0077] S4, inject the inner phase fluid from the channel port at one end of tube A at a flow rate of 1.5 mL / h; inject the intermediate phase fluid from the channel port at the connection between tube A and tube C at a flow rate of 0.7 mL / h; inject the outer phase fluid from the channel port at the connection between tube B and tube C at a flow rate of 7 mL / h;

[0078] The inner phase fluid is introduced from the small tip of the cone end of tube A, and is wrapped by the middle phase fluid. Then, double emulsion droplets (W / O / W type) are formed under the shearing action of the outer phase fluid. Then, a 25W ultraviolet lamp provides 365nm ultraviolet light for curing. The curing time is 5s, and the acrylate-based wall material microcapsules with a particle size of about 358μm, an error of ≤50μm, and a shell thickness of 8.18μm are obtained. Figure 6 shown.

[0079] Figure 7 This is a microscope photo of the acrylic ester-based wall material microcapsules prepared in Example 1. As can be seen from the figure, the microcapsules prepared in the present invention are uniform in size.

[0080] Figure 8 The SEM images of the acrylic ester-based wall material microcapsules prepared in Example 1 at different magnifications, where a is 50 times and b is 1000 times. It can be seen from the figure that the microcapsules prepared in the present invention have a thinner shell thickness.

[0081] Example 2

[0082] Compared with Example 1, the difference is that the flow rate of the inner phase fluid is 1.2 mL / h, the flow rate of the middle phase fluid is 0.7 mL / h, the flow rate of the outer phase fluid is 7 mL / h, the photocuring time is 5 s, and the particle size of the prepared acrylate-based wall material microcapsules is about 342 μm, the error is ≤50 μm, and the shell thickness is 18.6 μm.

[0083] Example 3

[0084] Compared with Example 1, the difference is that the flow rate of the inner phase fluid is 1.5 mL / h, the flow rate of the middle phase fluid is 1.0 mL / h, the flow rate of the outer phase fluid is 7 mL / h, the photocuring time is 5 s, and the particle size of the prepared acrylate-based wall material microcapsules is about 402 μm, the error is ≤50 μm, and the shell thickness is 40.3 μm.

[0085] Example 4

[0086] Compared with Example 1, the difference is that the flow rate of the inner phase fluid is 1.5 mL / h, the flow rate of the middle phase fluid is 0.7 mL / h, the flow rate of the outer phase fluid is 5 mL / h, the photocuring time is 5 s, and the particle size of the prepared acrylate-based wall material microcapsules is about 422 μm, the error is ≤50 μm, and the shell thickness is 40.9 μm.

[0087] Fig. 9 These are microscope photos of acrylate-based wall material microcapsules prepared in Examples 1-4, wherein a is Example 1, b is Example 2, c is Example 3, and d is Example 4. Fig. 9 The scale bars are all 200 μm.

[0088] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0089] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A capillary microfluidic platform, characterized in that: The capillary microfluidic platform includes a microinjection system and a capillary chip; the microinjection system includes three microinjection pumps and three syringes; The capillary chip comprises a coaxially arranged A tube, a B tube and a C tube; Wherein, the A tube and the B tube are arranged relative to each other; the C tube is sleeved outside the A tube and the B tube; One end of the A tube, the connection between the A tube and the C tube, and the connection between the B tube and the C tube are respectively provided with an injection port A, an injection port B, and an injection port C; The injection port A, the injection port B and the injection port C are respectively connected to three syringes in the microinjection system which are respectively controlled by three microinjection pumps.

2. The capillary microfluidic platform according to claim 1, characterized in that: The cone end diameter of the A tube is 200 μm and the length is 3.2-3.5 cm; and / or the cone end diameter of the B tube is 500 μm and the length is 3.7-4.0 cm; and / or the C tube is a thick glass capillary with ID 1.05 mm / OD 1.15 mm and a length of 3.2-3.5 cm.

3. The capillary microfluidic platform according to claim 1, characterized in that: The A tube is treated to be hydrophobic.

4. The capillary microfluidic platform according to claim 1, characterized in that: The B tube and the C tube are subjected to hydrophilic treatment.

5. A method for preparing acrylate-based wall material microcapsules based on microfluidic double emulsion technology, using the capillary microfluidic platform according to any one of claims 1 to 4, comprising the following steps: The inner phase fluid is injected from the channel port at one end of tube A, the middle phase fluid is injected from the channel port at the connection between tube A and tube C, and the outer phase fluid is injected from the channel port at the connection between tube B and tube C to form double emulsion droplets of uniform size, which are cured by ultraviolet light to form acrylate-based wall material microcapsules; The internal phase fluid consists of water and PVA; The intermediate phase fluid is composed of methacryloxypropyl tris(trimethylsiloxy)silane, trimethylolpropane trimethacrylate and 2-hydroxy-2-methylpropiophenone; The external phase fluid consists of water and PVA.

6. The preparation method according to claim 5, characterized in that: The ratio of water to PVA in the inner phase fluid is 50 mL:2.5 g; and / or, the volume ratio of methacryloxypropyl tris(trimethylsiloxy)silane, trimethylolpropane trimethacrylate and 2-hydroxy-2-methylpropiophenone in the intermediate phase fluid is 0.7:3.5:0.8; and / or, the ratio of water to PVA in the outer phase fluid is 100 mL:5 g; and / or, the wavelength of ultraviolet light in the ultraviolet light curing is 365 nm, and the curing time is 5-10 s.

7. The preparation method according to claim 5, characterized in that: The flow rate of the inner phase fluid is 1.2-1.5 mL / h; and / or, the flow rate of the intermediate phase fluid is 0.7-1.0 mL / h; and / or, the flow rate of the outer phase fluid is 5-7 mL / h.

8. The preparation method according to claim 7, characterized in that: The flow rate of the inner phase fluid is 1.5 mL / h; and / or, the flow rate of the middle phase fluid is 0.7 mL / h; and / or, the flow rate of the outer phase fluid is 7 mL / h.

9. An acrylate-based wall material microcapsule with uniform size, characterized in that: It is prepared by the preparation method according to any one of claims 5 to 8.

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