Preparation method and application of responsive particles loaded with surfactant

Abstract

The invention relates to a preparation method and application of response type particles loaded with a surfactant, W / O / W type response characteristic particles capable of packaging a water-soluble surfactant and O / W type response characteristic particles capable of packaging an oil-soluble surfactant are prepared through a micro-fluidic chip, and the prepared particles are more uniform in size and performance. The oily carrier is beneficial to improving the stability of the surfactant in an aqueous solution, has a waterproof effect and can be used for a waterproof coating; the adsorption loss of the surfactant in rock in an oil reservoir can be effectively reduced, the loss of the surfactant is reduced, and efficient exploitation of an oil field can be realized; the oily polymer shell material incompatible with water can efficiently seal the content in the shell, so that the service life of the content is prolonged; the degradation rate and the membrane pore density of the material are changed by adjusting the concentration and the thickness of the shell layer material, and the shell layer material has nano-scale pores, so that the filtration of the nano-scale material can be realized; the material can have response characteristics to an environment containing an organic solvent.

Description

TECHNICAL FIELD

[0001] The present application relates to advanced petrochemical intelligent new materials, waterproof coating, high-molecular high-efficiency sealing agent, agricultural improvement of pesticide utilization rate and many other technical fields, in particular to a preparation method and application of a response type microparticle loaded with a surfactant, which combines microfluidic method and material performance to prepare particles with more uniform performance. BACKGROUND

[0002] Surfactants, with their unique molecular structure (hydrophilic and hydrophobic groups), are a class of substances that can significantly reduce the surface tension of liquids, and are widely used in various fields, including industry, medicine, agriculture, and environmental management. Surfactants may not be stable in certain environments, such as high temperatures, strong acids or strong bases, which can easily decompose them. By encapsulation technology, surfactants can be embedded or adsorbed in carrier materials, thereby improving their stability. In oral antibacterial applications, traditional surfactants are easily washed away by water and cannot stay on the surface of teeth for a long time. By combining surfactants with coatings to form composite coatings (GO / CSAA), the antibacterial effect can be significantly prolonged, and even after 7 days of storage in water, the activity can still be maintained. In the generation of nanobubbles, the adsorption of surfactants can significantly affect the diameter, concentration and stability of the bubbles, thereby optimizing their application in antibacterial or wastewater treatment. Direct use of surfactants can have adverse effects on the human body. By encapsulation technology, their toxicity can be reduced and biocompatibility can be improved. For example, in insulin preparations, surfactants are used to inhibit protein aggregation, thereby improving the stability and efficacy of the drug.

[0003] Therefore, by encapsulating surfactants through microfluidic technology, the size and performance of the particles can be uniformly controlled, and the intelligent response characteristics of the encapsulating material can endow the surfactants with new functions, such as water resistance, oil response, improved stability in water, prolonged stability time in water, and release under specific response conditions to improve the stability of surfactants, increase the concentration of surfactants, and reduce the loss of surfactants. SUMMARY

[0004] In view of the above problems existing in the prior art, the technical problem to be solved by the present application is to enhance the stability of surfactants, improve their action time in aqueous solution, effectively reduce the adsorption loss of surfactants in aqueous solution, and improve the service life of surfactants by microfluidic encapsulation technology.

[0005] To solve the above technical problems, the application adopts the following technical scheme: a capillary micro-fluidic chip, comprising a square tube, two drawn capillary tubes and a collection container, the two capillary tubes have a head at one end with a small diameter, the tips of the two capillary tubes are located in the square tube, and the tips of the two capillary tubes are gap-fitted (there are two cases for the gap-fitted, one case is that there is a gap between the tips of the two capillary tubes, and the gap is not greater than 300 microns, and the other case is that the tip of one capillary tube is inserted into the tip of the other capillary tube), the tails of the two capillary tubes are both extended out of the square tube, the tail of one capillary tube is an injection end, the tail of the other capillary tube is a collection end, and the square tube and the two capillary tubes are coaxial; a channel in the injection end capillary tube is defined as an inner phase channel, a gap between the outer wall of the injection end capillary tube and the inner wall of the square tube is defined as an intermediate phase channel, and a gap between the outer wall of the collection end capillary tube and the inner wall of the square tube is defined as an outer phase channel.

[0006] The capillary micro-fluidic chip further comprises an inner phase fluid injector in communication with the inner phase channel through an inner phase fluid injection tube, an intermediate phase injector in communication with the intermediate phase channel through an intermediate phase fluid injection tube, and an outer phase injector in communication with the outer phase channel through an outer phase fluid injection tube.

[0007] The capillary micro-fluidic chip further comprises a collection tube in communication with the collection container at one end and with the collection end at the other end.

[0008] Preferably, the tips of the two capillary tubes have a diameter of 20-300 microns.

[0009] A preparation method of a surfactant-loaded responsive micro-particle, characterized in that the capillary micro-fluidic chip is used, and the method comprises the following steps:

[0010] An inner phase fluid is injected into the inner phase channel through the inner phase fluid injector, an intermediate phase fluid is injected into the intermediate phase channel through the intermediate phase injector, and an outer phase fluid is injected into the outer phase channel through the outer phase injector, the inner phase fluid, the intermediate phase fluid and the outer phase fluid are mixed through the collection tube to obtain W / O / W emulsion droplets, and finally the W / O / W responsive micro-particles are obtained in the collection container through the output end of the collection tube; after the W / O / W responsive micro-particles are cleaned, the surfactant-loaded micro-capsules are formed. The micro-capsule structure comprises, from the inside to the outside, a coated surfactant solution, a film with a response characteristic and an outer phase containing a stabilizer.

[0011] The flow rate of the inner phase fluid, the middle phase fluid and the outer phase fluid ranges from 100 μL / h to 1000 μL / h, 500 μL / h to 2000 μL / h and 4000 to 20000 μL / h, respectively. The dispersed phase fluid is injected into the inner phase channel through the inner phase fluid injector, the continuous phase fluid is injected into the middle phase channel through the middle phase injector, the dispersed phase fluid and the continuous phase fluid are mixed in the fluid collection tube to obtain the O / W emulsion droplets, and finally the O / W response characteristic microparticles are obtained in the collection container through the output end of the collection tube; after the O / W response characteristic microparticles are washed, the microspheres are formed, and the surfactant is encapsulated in the hydrogel. The flow rate of the dispersed phase fluid and the continuous phase fluid ranges from 50 μL / h to 1000 μL / h and 2000 μL / h to 20000 μL / h, respectively.

[0012] Preferably, the inner phase fluid for forming the W / O / W emulsion droplets is an aqueous solution prepared by using distilled water and a surfactant, and the mass fraction of the surfactant ranges from 1wt% to 20wt%. The surfactant can be selected from Tween 80, Triton 100, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, betaine surfactant, cetyltrimethylammonium chloride and dodecyltrimethylammonium chloride.

[0013] Preferably, the middle phase fluid for forming the W / O / W emulsion droplets or the continuous phase fluid for forming the O / W emulsion droplets is an aqueous solution prepared by using a water-immiscible liquid, wherein the water-immiscible liquid is an oil-soluble polymer with a mass fraction of 1wt% to 40wt%, or a mixture of a monomer with a mass fraction of 1wt% to 40wt% and an initiator with a mass fraction of 0.1wt% to 5wt%. This facilitates rapid shell formation of the capsule. The solvent of the oil-soluble polymer, the monomer and the initiator is an organic solvent, which can be selected from dichloromethane, mineral oil, paraffin oil and toluene. The middle phase fluid forms a film in the W / O / W response characteristic microparticles, and the oil-soluble polymer used in the middle phase fluid can be selected from polylactic acid, polybutylene succinate, polybutylene terephthalate-adipate, polystyrene and polyhydroxyalkanoate; the monomer used in the middle phase fluid is polyethylene glycol diacrylate, butyl methacrylate, methyl methacrylate or styrene, and the initiator used in the middle phase fluid is 2-hydroxy-2-methyl-1-phenyl-1-propanone, azobisisobutyronitrile or benzoyl peroxide.

[0014] Preferably, the outer phase fluid for forming the W / O / W emulsion droplets is an aqueous solution prepared by using distilled water, a stabilizer and sodium chloride, and the mass fraction of the stabilizer ranges from 0.5wt% to 15wt%, and the mass fraction of sodium chloride ranges from 0 to 1wt%. The stabilizer can be selected from an aqueous solution of a polysaccharide compound with different molecular weights and sodium chloride.

[0015] As a preferred embodiment, the dispersing fluid for forming the O / W emulsion droplet is an oil-soluble solution prepared using a surfactant and a water-insoluble material, wherein the mass fraction of the surfactant is 1wt% to 30wt%, the mass fraction of the water-insoluble polymer ranges from 1wt% to 40wt%, or a mixture of 1wt% to 40wt% monomers and 0.1wt% to 5wt% initiator, and the solvent for the surfactant and the water-insoluble polymer is an organic solvent. The organic solvent can be selected from dichloromethane, mineral oil, paraffin oil or toluene, the oil-soluble polymer used in the dispersing fluid can be selected from polylactic acid, polybutylene succinate, polybutylene terephthalate-adipate, polystyrene and polyhydroxyalkanoate, the oil-soluble monomer can be selected from polyethylene glycol diacrylate, butyl methacrylate, methyl methacrylate or styrene, and the initiator used in the intermediate phase fluid can be 2-hydroxy-2-methyl-1-phenyl-1-propanone, azobisisobutyronitrile or benzoyl peroxide. The surfactant used in the dispersing fluid can be selected from Span 80, polyglyceryl ricinoleate, oleic acid, oleylamine and OP-4.

[0016] As a preferred embodiment, the continuous phase fluid for forming the O / W emulsion droplet is an aqueous solution prepared using distilled water and a stabilizer, wherein the mass fraction of the stabilizer ranges from 0.5wt% to 15wt%. The stabilizer can be an aqueous solution of polysaccharide compounds with different molecular weights.

[0017] As a preferred embodiment, the particle size of the prepared W / O / W responsive characteristic microparticles ranges from 40μm to 300μm, and the shell thickness of the W / O / W responsive characteristic microparticles ranges from 500nm to 50μm; the particle size of the prepared O / W responsive characteristic microparticles ranges from 40μm to 500μm.

[0018] An application of the surfactant-loaded responsive microparticles, the responsive microparticles prepared by the above method are applied in new materials or waterproof coatings or high-molecular-weight efficient sealing agents.

[0019] Compared with the prior art, the present application has at least the following advantages:

[0020] 1. The present application proposes a preparation method and test method of surfactant-loaded responsive microparticles, which aims to enhance the stability of surfactant, improve the action time in aqueous solution, effectively reduce the adsorption loss of surfactant in external environment, and improve the service life of surfactant by microfluidic wrapping technology. The adsorption loss of surfactant in the process of oil exploitation can be effectively reduced, the consumption of surfactant can be reduced, the comprehensive utilization efficiency of surfactant can be improved, and efficient exploitation of oil field can be realized. 2. The present application uses microfluidic method to prepare W / O / W type responsive characteristic microparticles, i.e. microcapsules, and O / W type responsive characteristic microparticles, i.e. microspheres, which can accurately control the transportation and fusion of three inner liquid drops of inner phase channel, middle phase channel and outer phase channel, and realize rapid mixing in the channel with small liquid consumption. The microfluidic method can timely change the structure of microspheres by changing the injection flow rate, which is more controllable than the previous synthesis experiment, and the required emulsion size can be obtained in a short time.

[0021] 3. The prepared microcapsules and microspheres can load various types of surfactants, and the stability of surfactant in aqueous solution can be improved by encapsulating surfactant. The surfactant is encapsulated by hydrophobic material, which not only achieves the effect of waterproofing as a hydrophobic coating, but also makes the whole particle have intelligent response characteristics by using responsive material. It can achieve waterproofing effect and can be used for waterproofing coating, and at the same time, it can realize efficient sealing of the contents in the shell.

[0022] 4. The particle size of the particles prepared by microfluidic method is more uniform and the structure is controllable. By adjusting the concentration of oil-soluble material and the thickness of shell layer, the degradation rate of material and the pore density of material film can be changed. The degradation characteristics are helpful for green environmental protection, and the nanometer pores of the film material can help to realize nanofiltration and block the passage of small molecular weight substances, which can be used for filtering liquid.

[0023] 5. By microfluidic wrapping technology, it is helpful to prepare particles with more uniform size and performance, which can enhance the stability of surfactant, improve the stability in aqueous solution, effectively reduce the adsorption loss of surfactant in the process of oil exploitation, prolong the service life of surfactant, reduce the consumption of surfactant, improve the comprehensive utilization efficiency of surfactant, and realize efficient exploitation of oil field. The oil polymer shell material incompatible with water can achieve waterproofing effect and be used for waterproofing coating, and at the same time, it can realize efficient sealing of the contents in the shell. By adjusting the concentration of oil-soluble material and the thickness of shell layer, the degradation rate of material and the pore density of material film can be changed. The degradation characteristics are helpful for green environmental protection, and the nanometer pores of the film material can help to realize nanofiltration and block the passage of small molecular weight substances, which can be used for filtering liquid. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1A schematic diagram of a microfluidic chip.

[0025] Figure 2 A schematic diagram of a microcapsule loaded with a water-soluble surfactant.

[0026] Figure 3 A schematic diagram of a microsphere loaded with an oil-soluble surfactant.

[0027] Reference numerals: 1 - outer phase syringe, 2 - intermediate phase syringe, 3 - inner phase fluid syringe, 4 - square tube, 5 - injection end, 6 - collection end, 7 - glass sheet, 8 - outer phase fluid injection tube, 9 - intermediate phase fluid injection tube, 10 - inner phase fluid injection tube, 11 - collection tube, 12 - collection container. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below.

[0029] Example 1: Preparation of W / O / W type responsive micro-particles, i.e. microcapsules, and performance testing:

[0030] S1: Preparation of a microfluidic chip: the sizes of the two capillary tips were 30 μm and 200 μm, respectively.

[0031] S2: Preparation of microcapsules

[0032] (1) Preparation of an inner phase fluid: 2 g of Tween 80 was dissolved in 18 g of distilled water;

[0033] (2) Preparation of an intermediate phase fluid: 8 g of polybutylene succinate was dissolved in 12 g of chloroform;

[0034] (3) Preparation of an outer phase fluid: 3 g of a polysaccharide compound and 0.04 g of sodium chloride were dissolved in 16.96 g of distilled water;

[0035] (4) The fluids (1), (2) and (3) were sequentially injected from the three injection ports of the microfluidic chip;

[0036] (5) By adjusting the flow rates of the three liquids, the inner phase flow rate was 500 μL / h, the intermediate phase flow rate was 2000 μL / h, and the outer phase flow rate was 8000 μL / h, a multiple emulsion droplet was synthesized, and after washing, a microcapsule loaded with a surfactant was obtained;

[0037] (6) The particle size of the core-shell particles was measured by image analysis software of a microscope, and the particle size of the microcapsule was measured to be 80 μm, and the shell thickness was about 4 μm.

[0038] S3: Performance testing

[0039] (1) 0.3 g of microcapsules, 0.02 g of sodium chloride and 9.68 g of water were mixed to obtain a suspension of microcapsules;

[0040] (2) Water release experiment: After standing, the microcapsules sink to the bottom, and the concentration of sodium dodecyl sulfate in the supernatant is measured at different time periods. The release amount is 1.8% within 10 days;

[0041] (3) Organic solvent response experiment: 0.3 g of microcapsules is mixed with 0.3 g of toluene, and the microcapsules are broken within 10 min, indicating that the capsules have intelligent response characteristics.

[0042] Example 2-40 has the same process steps as Example 1, except for the selection, mass fraction, and flow rate of the inner phase fluid, the middle phase fluid, and the outer phase fluid. See Table 1 for details.

[0043] Table 1 Change in inner phase fluid injection process parameters

[0044]

[0045] Wherein, the unit of flow rate is μL / h; the unit of pipe diameter is μm; the unit of mass fraction is wt%.

[0046] The performance test results of the preparation of W / O / W type response characteristic microparticles of Example 1-10 are shown in Table 2.

[0047] Table 2 Performance of W / O / W type response characteristic microparticles

[0048]

[0049] As can be seen from Table 2, the higher the concentration of water-soluble surfactant in the inner phase of the W / O / W type response characteristic microparticles, the stronger the interfacial interaction, which enhances the stability of the inner phase and the intermediate phase, has a greater impact on the particle size, and can reduce the size of the microcapsules, but has little effect on the shell thickness and release. Different types of surfactants have a greater impact on the interface between the inner phase and the intermediate phase, which can change the size of the microcapsules, but has little effect on the shell thickness and release.

[0050] Table 3 Change in intermediate phase fluid injection process parameters

[0051]

[0052]

[0053] Wherein, the unit of flow rate is μL / h; the unit of pipe diameter is μm; the unit of mass fraction is wt%.

[0054] Table 4 Performance of W / O / W type response characteristic microparticles

[0055] Property 1 (particle size and shell thickness) Property 2 (release rate in water for 10 days) Property 3 (response characteristics in organic solvents) Example 11 Particle size 79.4 μm, shell thickness 3.7 μm Release amount in 10 days 2.1% Break in toluene in 8 min Example 12 Particle size 78.6 μm, shell thickness 3.3 μm Release amount in 10 days 2.8% Break in toluene in 8 min Example 13 Particle size 78 μm, shell thickness 3 μm Release amount in 10 days 3.9% Break in toluene in 6 min Example 14 Particle size 77.2 μm, shell thickness 2.6 μm Release amount in 10 days 5.0% Break in toluene in 5 min Example 15 Particle size 72 μm, shell thickness 4 μm Release amount in 10 days 1.1% Break in toluene in 3 min Example 16 Particle size 72 μm, shell thickness 4 μm Release amount in 10 days 0.8% Break in toluene in 15 min Example 17 Particle size 72 μm, shell thickness 4 μm Release amount in 10 days 0.6% Break in toluene in 8 min Example 18 Particle size 72 μm, shell thickness 4 μm Release amount in 10 days 2.3% Break in toluene in 10 min Example 19 Particle size 72 μm, shell thickness 4 μm Release amount in 10 days 1.6% Break in toluene in 5 min Example 20 Particle size 72 μm, shell thickness 4 μm Release amount in 10 days 2.0% Break in toluene in 12 min

[0056] As shown in Table 4, the higher the concentration of the W / O / W type response characteristic microparticle intermediate phase oil-soluble polymer, the thicker the shell and the larger the particle size, the shell thickness has a greater impact, the release amount in water is reduced, and the response to organic solvents will be slower. Different types of shell materials have different response regularities, but have little effect on particle size.

[0057] Table 5 Change of outer phase fluid injection process parameters

[0058] Wherein, the unit of flow rate is μL / h; the unit of pipe diameter is μm; the unit of mass fraction is wt%.

[0059] Table 6 Performance of W / O / W type response characteristic microparticles

[0060] Property 1 (particle size and shell thickness) Property 2 (release rate in water for 10 days) Property 3 (response characteristics in organic solvents) Example 21 Particle size 80.8 μm, shell thickness 4.4 μm Release amount in 10 days 2.0% Break in toluene in 10 min Example 22 Particle size 82.6 μm, shell thickness 5.3 μm Release amount in 10 days 2.3% Break in toluene in 11 min Example 23 Particle size 83 μm, shell thickness 5.5 μm Release amount in 10 days 2.9% Break in toluene in 13 min Example 24 Particle size 84.6 μm, shell thickness 6.3 μm Release amount in 10 days 3.0% Break in toluene in 15 min Example 25 Particle size 86 μm, shell thickness 7 μm Release amount in 10 days 4.1% Break in toluene in 19 min

[0061] As shown in Table 6, the lower the content of the W / O / W type response characteristic microparticle outer phase stabilizer, the weaker the ability to stabilize the oil-water interface, the larger the microcapsule particle size, the shell thickness is increased, resulting in enhanced water stability, and the response to organic solvents is weakened.

[0062] Table 7 Variable flow rate and capillary tip diameter

[0063]

[0064] Wherein, the unit of flow rate is μL / h; the unit of pipe diameter is μm; the unit of mass fraction is wt%.

[0065] Table 8 Performance of W / O / W type response characteristic microparticles

[0066]

[0067]

[0068] As shown in Table 8, increasing the flow rate of the W / O / W type response characteristic microparticle inner phase or intermediate phase will increase the microcapsule particle size; increasing the flow rate of the outer phase will reduce the particle size. Under the condition of constant three-phase flow rate, the smaller the capillary tip size, the stronger the shear force, which will reduce the microcapsule particle size to a certain extent, but the overall impact is weak.

[0069] From Tables 1-8, further in connection with the preparation method of the present application, it can be seen that the microcapsules prepared by the microfluidic method can change the parameters of the three-phase fluid, the three-phase fluid does not interfere with each other in the respective channels, and the microcapsules encapsulating the water-soluble surfactant are quickly prepared at the fluid intersection; by adjusting the flow rate and the effective components of the inner and outer phases, the particle size and shell thickness size can be controlled, by adjusting the effective content and concentration of the intermediate phase fluid, the stability in water and the response time to organic solvents can be adjusted; the microcapsule particles prepared by the microfluidic method are more uniform, so that the physical and chemical properties of the microcapsules are more uniform and stable; the degradation rate of the oil-soluble material in water is slow, so that the stability of the shell layer in water is strong; the oil-soluble material is more sensitive to organic solvents, and is more easily broken after contacting the organic solvents, thereby having a response characteristic.

[0070] Example 41: Preparation of O / W type response characteristic microparticles, i.e. microspheres:

[0071] S1: Preparation of microfluidic chip: the sizes of the capillary tips are 30 μm and 200 μm, respectively.

[0072] S2: Preparation of microparticles

[0073] (1) Preparation of dispersed phase solution: 6 g of Span 80 and 4 g of polybutylene succinate were dissolved in 10 g of chloroform;

[0074] (2) Preparation of continuous phase solution: 3 g of polysaccharide compound was dissolved in 17 g of distilled water;

[0075] (3) The fluids (1) and (2) were sequentially injected from the two injection ports of the microfluidic chip;

[0076] (4) By adjusting the flow rates of the three liquids, the dispersed phase flow rate was 200 μL / h, and the continuous phase flow rate was 4000 μL / h, to synthesize single emulsion droplets, and after cleaning, the microparticles loaded with surfactant were obtained;

[0077] (5) The particle size of the microparticles was measured by the image analysis software of the microscope, and the particle size of the microcapsules was 53 μm.

[0078] S3: Performance test

[0079] (1) 0.3 g of microcapsules and 9.7 g of water were mixed to obtain a suspension of microparticles;

[0080] (2) Water release experiment: after standing, the microparticles sank to the bottom, and the concentration of Span 80 in the supernatant was measured at different time periods.

[0081] The release amount within 10 days was 2.3%;

[0082] (3) Organic solvent response experiment: 0.3 g of the microcapsules were mixed with 0.3 g of dichloromethane, and the microcapsules deformed within 3 min, indicating that the microcapsules had intelligent response characteristics.

[0083] Examples 42-79 were identical to the process steps of Example 41, except for the selection, mass fraction, and flow rate of the inner phase fluid, middle phase fluid, and outer phase fluid, as shown in Table 9.

[0084] Table 9 Process parameters for varying dispersed phase fluid injection

[0085]

[0086] wherein the flow rate is in μL / h; the tube diameter is in μm; and the mass fraction is in wt%.

[0087] Table 10 Performance of O / W type response characteristic microcapsules

[0088]

[0089]

[0090] As shown in Table 10, in the O / W type response characteristic microcapsules, decreasing the concentration of the oil-soluble surfactant in the dispersed phase and increasing the concentration of the oil-soluble polymer can increase the particle size, and the release amount in water gradually decreases, and the response gradually weakens. Different types of surfactants have an effect on the particle size, but have no effect on the release in water and the response to organic solvents. The type of oil-soluble polymer has little effect on the particle size, but has an effect on the release in water and the response to organic solvents.

[0091] Table 11 Process parameters for varying continuous phase injection

[0092]

[0093] wherein the flow rate is in μL / h; the tube diameter is in μm; and the mass fraction is in wt%.

[0094] Table 12 Performance of O / W type response characteristic microcapsules

[0095] Property 1 (particle size) Property 2 (release rate in water for 10 days) Property 3 (response characteristics in organic solvents) Example 61 62 μm Release amount in 10 days 3.3% Deformation in dichloromethane in 2 min Example 62 64 μm Release amount in 10 days 3.3% Deformation in dichloromethane in 2 min Example 63 69 μm Release amount in 10 days 3.3% Deformation in dichloromethane in 2 min Example 64 72 μm Release amount in 10 days 3.3% Deformation in dichloromethane in 2 min Example 65 76 μm Release amount in 10 days 3.3% Deformation in dichloromethane in 2 min

[0096] As shown in Table 12, in the O / W type response characteristic microcapsules, the lower the content of the continuous phase stabilizer, the weaker the ability to stabilize the oil-water interface, and the larger the particle size. However, the type of continuous phase stabilizer has no effect on the release in water and the response to organic solvents.

[0097] Table 13 Parameters for varying flow rate and capillary tip diameter

[0098]

[0099]

[0100] wherein the flow rate is in μL / h; the tube diameter is in μm; and the mass fraction is in wt%.

[0101] Table 14 Performance of O / W responsive microspheres

[0102] Property 1 (particle size) Property 2 (release rate in water for 10 days) Property 3 (response characteristics in organic solvents) Example 66 47 μm Release amount in 10 days 3.3% Deformation in dichloromethane in 2 min Example 67 55 μm Release amount in 10 days 3.3% Deformation in dichloromethane in 2 min Example 68 68 μm Release amount in 10 days 3.3% 2 min deformation in dichloromethane Example 69 76 μm Release 3.3% in 10 days 2 min deformation in dichloromethane Example 70 84 μm Release 3.3% in 10 days 2 min deformation in dichloromethane Example 71 71 μm Release 3.3% in 10 days 2 min deformation in dichloromethane Example 72 55 μm Release 3.3% in 10 days 2 min deformation in dichloromethane Example 73 52 μm Release 3.3% in 10 days 2 min deformation in dichloromethane Example 74 50 μm Release 3.3% in 10 days 2 min deformation in dichloromethane Example 75 46 μm Release 3.3% in 10 days 2 min deformation in dichloromethane Example 76 71 μm Release 3.3% in 10 days 2 min deformation in dichloromethane Example 77 96 μm Release 3.3% in 10 days 2 min deformation in dichloromethane Example 78 56 μm Release 3.3% in 10 days 2 min deformation in dichloromethane Example 79 60 μm Release 3.3% in 10 days 2 min deformation in dichloromethane

[0103] From Table 14, it can be seen that in the O / W responsive microspheres, increasing the flow rate of the dispersed phase and decreasing the flow rate of the continuous phase can increase the particle size, but have no effect on the release in water and response to organic solvents. Decreasing the tip diameter can increase the shear force on the particles, resulting in a decrease in the particle size, but have no effect on the release in water and response to organic solvents.

[0104] From Tables 9-14, further in connection with the preparation method of the present application, it can be seen that the microcapsules prepared by the microfluidic method can change the parameters of the two-phase fluid, the fluids do not interfere with each other in the respective channels, and the microspheres can be quickly prepared by wrapping the oil-soluble surfactant at the fluid intersection, and the prepared particles are more uniform. The particle size can be changed by adjusting the flow rate and the concentration of the oil-soluble surfactant in real time. The physical and chemical properties of the particles can be changed by adjusting the content of the oil-soluble polymer. Increasing the concentration of the oil-soluble material can slow the degradation rate of the particles in water, and the stability of the microspheres in water is strong. Decreasing the concentration of the oil-soluble material can enhance the sensitivity of the particles to organic solvents, and the particles can be more easily deformed after contacting the organic solvents, thereby having a response characteristic.

[0105] Finally, it should be pointed out that the above examples are only used to illustrate the technical solutions of the present application and not to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the purpose and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A capillary microfluidic chip, characterized in that: The container includes a square tube (4), two drawn capillary tubes, and a collection container (12). The smaller end of the two capillary tubes is the head, and the tips of the two capillary tubes are located inside the square tube (4). The heads of the two capillary tubes are fitted with a gap, and the tails of the two capillary tubes extend out of the square tube (4). The tail of one capillary tube is the injection end (5), and the tail of the other capillary tube is the collection end (6). The square tube (4) and the two capillary tubes are coaxial. The channel inside the capillary tube at the injection end (5) is defined as the inner phase channel, the gap between the outer wall of the capillary tube at the injection end (5) and the inner wall of the square tube (4) is defined as the intermediate phase channel, and the gap between the outer wall of the capillary tube at the collection end (6) and the inner wall of the square tube (4) is defined as the outer intermediate phase channel. It also includes an inner phase fluid injector (3) connected to the inner phase channel via an inner phase fluid injection tube (10), an intermediate phase injector (2) connected to the intermediate phase channel via an intermediate phase fluid injection tube (9), and an outer phase injector (1) connected to the outer phase channel via an outer phase fluid injection tube (8). It also includes a collection tube (11) with one end connected to the collection container (12) and the other end connected to the collection end (6).

2. The capillary microfluidic chip as described in claim 1, characterized in that: The tip diameter of the two capillaries is 20-300 μm.

3. A method for preparing responsive microparticles loaded with surfactant, characterized in that: The capillary microfluidic chip as defined in claim 1 or 2 includes the following steps: The inner phase fluid is injected into the inner phase channel through the inner phase fluid injector (3), the middle phase fluid is injected into the middle phase channel through the intermediate phase injector (2), and the outer phase fluid is injected into the outer phase channel through the outer phase injector (1). The inner phase fluid, the middle phase fluid and the outer phase fluid are mixed in the collection tube (11) to obtain W / O / W type emulsion droplets. Finally, W / O / W type responsive microparticles are obtained in the collection container (12) through the output end of the collection tube (11). The flow rate ranges for the inner phase fluid, middle phase fluid, and outer phase fluid are 100 μL / h to 1000 μL / h, 500 μL / h to 2000 μL / h, and 4000 to 20000 μL / h, respectively. Dispersed phase fluid is injected into the inner phase channel through the inner phase fluid injector (3), and continuous phase fluid is injected into the intermediate phase channel through the intermediate phase injector (2). The dispersed phase fluid and the continuous phase fluid are mixed in the collection tube (11) to obtain O / W type emulsion droplets. Finally, O / W type responsive microparticles are obtained in the collection container (12) through the output end of the collection tube (11). The flow rates of the dispersed phase fluid and the continuous phase fluid were 50 μL / h to 1000 μL / h and 2000 μL / h to 20000 μL / h, respectively.

4. The method for preparing responsive microparticles loaded with surfactant as described in claim 3, characterized in that: The internal phase fluid that forms W / O / W type emulsion droplets is an aqueous solution prepared using distilled water and a surfactant, with the surfactant mass fraction ranging from 1 wt% to 20 wt%.

5. The method for preparing responsive microparticles loaded with surfactant as described in claim 3, characterized in that: The intermediate phase fluid that forms W / O / W type emulsion droplets or the continuous phase fluid that forms O / W type emulsion droplets is a water-immiscible liquid, wherein the water-immiscible liquid is a mixture of 1 wt% to 40 wt% oil-soluble polymer or 1 wt% to 40 wt% monomer and 0.1 wt% to 5 wt% initiator.

6. The method for preparing responsive microparticles loaded with surfactant as described in claim 3, characterized in that: The external phase fluid that forms the W / O / W type emulsion droplets is an aqueous solution prepared using distilled water, a stabilizer, and sodium chloride, with the stabilizer having a mass fraction ranging from 0.5 wt% to 15 wt% and the sodium chloride having a mass fraction ranging from 0 to 1 wt%.

7. The method for preparing responsive microparticles loaded with surfactant as described in claim 3, characterized in that: The dispersing fluid that forms O / W type emulsion droplets is an oil-soluble solution prepared using a surfactant and a water-insoluble material, wherein the surfactant has a mass fraction of 1 wt% to 30 wt%, the water-insoluble polymer has a mass fraction of 1 wt% to 40 wt%, or a mixture consisting of a monomer with a mass fraction of 1 wt% to 40 wt% and an initiator with a mass fraction of 0.1 wt% to 5 wt%, and the surfactant and the water-insoluble polymer are in the form of an organic solvent.

8. The method for preparing responsive microparticles loaded with surfactant as described in claim 3, characterized in that: The continuous phase fluid that forms O / W type emulsion droplets is an aqueous solution prepared using distilled water and a stabilizer, with the stabilizer mass fraction ranging from 0.5 wt% to 15 wt%.

9. The method for preparing responsive microparticles loaded with surfactant as described in claim 3, characterized in that: The particle size of the prepared W / O / W type responsive microparticles is 40μm to 300μm, and the shell thickness of the W / O / W type responsive microparticles is 500nm to 50μm; the particle size of the prepared O / W type responsive microparticles is 40μm to 500μm.

10. The application of a surfactant-loaded responsive microparticle, characterized in that, The responsive microparticles prepared by the method according to any one of claims 3-9 can be applied to new materials, waterproof coatings, or high-efficiency polymeric sealing agents.

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