阅读说明：本技术 一种粒径均匀可控的体系稳定的油水乳液的制备方法 (Preparation method of oil-water emulsion with uniform and controllable particle size and stable system ) 是由 王国勇 李双鑫 于 2021-08-10 设计创作，主要内容包括：本发明提供一种粒径均匀可控的体系稳定的油水乳液的制备方法,涉及油水乳液制备技术领域。该粒径均匀可控的体系稳定的油水乳液的制备方法：S1、溶液的制备,量取实验所需的水和油试剂,按照适当比例,S2、三通针头的制备,选择一个孔径较小的27G的平头针头a,在其前端嵌套一个较大孔径的第一21G的平头针头b。该粒径均匀可控的体系稳定的油水乳液的制备方法,避免外加作用力分布不均匀,导致分散相粒径差异,粒径大小可控,调节分散相和连续相的比例,调节微流器推进速度,改变分散相在乳液中粒径大小,例如降低分散相在油水乳液系统中占比,或增大连续相在油水乳液系统中占比,可以减小分散相小球在油水乳液中的直径。(The invention provides a preparation method of a system-stable oil-water emulsion with uniform and controllable particle size, and relates to the technical field of oil-water emulsion preparation. The preparation method of the oil-water emulsion with uniform and controllable particle size and stable system comprises the following steps: s1, preparing a solution, namely measuring water and an oil reagent required by the experiment, preparing a three-way needle according to a proper proportion S2, selecting a 27G flat-head needle a with a smaller aperture, and nesting a first 21G flat-head needle b with a larger aperture at the front end of the flat-head needle a. The preparation method of the oil-water emulsion with the uniform and controllable particle size and stable system can avoid the condition that the distribution of external acting force is not uniform, so that the particle size difference of a dispersion phase is caused, the particle size is controllable, the proportion of the dispersion phase and a continuous phase is adjusted, the propelling speed of a micro-flow device is adjusted, the particle size of the dispersion phase in the emulsion is changed, for example, the proportion of the dispersion phase in an oil-water emulsion system is reduced, or the proportion of the continuous phase in the oil-water emulsion system is increased, so that the diameter of a dispersion phase globule in the oil-water emulsion can be reduced.)

1. A preparation method of a system-stable oil-water emulsion with uniform and controllable particle size is characterized by comprising the following steps: the method comprises the following steps:

s1, preparation of a solution: measuring water and oil reagents required by an experiment according to a proper proportion;

s2, preparing a three-way needle: selecting a 27G flat-head needle head a with a smaller aperture, and nesting a first 21G flat-head needle head b with a larger aperture at the front end of the flat-head needle head a;

s3, preparing emulsion with uniform particle size: injecting the dispersed phase reagent and the continuous phase reagent prepared in the step S1 into a syringe with proper volume respectively, and then arranging the syringe on the micro-flow syringe to be connected with the three-way needle.

2. The method for preparing the system-stable oil-water emulsion with uniform and controllable particle size according to claim 1, wherein the method comprises the following steps: in S1, a proper emulsifier is selected, for example, a water-in-oil solution is prepared, that is, a span-type emulsifier is selected, and an oil-in-water solution is prepared, that is, a tween-type emulsifier is selected.

3. The method for preparing the system-stable oil-water emulsion with uniform and controllable particle size according to claim 1, wherein the method comprises the following steps: in the S1, the emulsifier is added into the continuous phase and is subjected to ultrasonic treatment to be uniformly mixed.

4. The method for preparing the system-stable oil-water emulsion with uniform and controllable particle size according to claim 1, wherein the method comprises the following steps: in said S2, a hole is punched on the side of the flat-head needle b of the first 21G by a puncher, another flat-head needle c of the second 21G is introduced into the hole, and a plastic tube is connected to the end of the flat-head needle c of the second 21G to connect the flat-head needle d of the third 21G.

5. The method for preparing the system-stable oil-water emulsion with uniform and controllable particle size according to claim 1, wherein the method comprises the following steps: in the S2, a micro-flow tube is externally connected to the front end of the flat-head needle b of the first 21G to guide the prepared oil-water emulsion.

6. The method for preparing the system-stable oil-water emulsion with uniform and controllable particle size according to claim 1, wherein the method comprises the following steps: in S2, the seam of the whole tee joint device is fixed by a hot glue gun to prevent solution leakage in the experimental process, water is injected into the tee joint needle to check the sealing performance of the tee joint needle, then the tee joint needle is immersed into absolute ethyl alcohol for ultrasonic cleaning, and the tee joint device is dried at normal temperature.

7. The method for preparing the system-stable oil-water emulsion with uniform and controllable particle size according to claim 1, wherein the method comprises the following steps: in the step S3, an instrument is set, parameters of the injectors are calibrated, the appropriate propelling speed is adjusted, and the liquid in the two injectors flows out at different speeds, and is converged in the three-way needle to form emulsion with uniform particle size, and flows out from the micro-flow tube.

Technical Field

The invention relates to a preparation method of an aqueous emulsion, in particular to a preparation method of a stable system oil-water emulsion with uniform and controllable particle size, belonging to the technical field of oil-water emulsion preparation.

Background

The emulsion is a dispersed system prepared by two mutually insoluble liquids through methods of mechanical mixing and the like, and is a thermodynamically unstable system. When emulsion preparation is carried out, there is interfacial tension between the water-oil interface, with the level free energy. When the dispersed phases in the emulsion meet each other, the spontaneous phase combination occurs, reducing the total area of the water-oil interface in the emulsion system, so as to reduce the total interfacial energy in the emulsion system. The process belongs to a thermodynamic spontaneous process, and emulsion breaking, layering and the like of the emulsion can be caused. In order to solve the problems, the stability of an emulsion system is increased, so that the purpose that the emulsion can be stored for a long time under the experimental requirements is achieved. During the preparation of the emulsion, a certain amount of emulsifier is added to the water-oil system. Due to the characteristics of the emulsifier and the special molecular structure of the emulsifier, the molecules of the emulsifier can be directionally arranged on a water-oil interface, and the stability of the water-oil interface can be improved because one end of a surface functional group of the emulsifier is hydrophilic and the other end of the surface functional group is oleophilic. Therefore, during the preparation of the emulsion, a certain amount of emulsifier needs to be added to the continuous phase to reduce the interfacial tension between the water-oil phase and increase the emulsion stability. The dispersed phase can stably exist in the emulsion, and the possibility of demulsification and copolymerization delamination is reduced.

1. Solves the problem of nonuniform particle size distribution of a dispersed phase in an oil-water emulsion in the prior emulsion preparation method. The distance between the dispersed phase and an external acting force source is different due to different positions of the dispersed phase in the oil-water mixed solution, and the acting force is reduced due to the increase of the distance between the acting force and a stress source, so that the particle sizes of the dispersed phase at different positions in the oil-water emulsion are different.

2. Solves the problem that the particle size of a dispersed phase in an oil-water emulsion is difficult to control in the existing emulsion preparation method. The particle size of the dispersed phase in the oil-water emulsion can be finely regulated and controlled by regulating the propelling speed of the micro-flow injector or changing the proportion of a continuous phase reagent and a dispersed phase reagent for preparing the emulsion.

Disclosure of Invention

Technical problem to be solved

The present invention aims to solve the above problems and provide a method for preparing a stable oil-water emulsion with a uniform and controllable particle size, so as to solve the problem of non-uniform particle size distribution of a dispersed phase in the oil-water emulsion in the prior art. The distance between the dispersed phase and an external acting force source is different due to different positions of the dispersed phase in the oil-water mixed solution, and the applied acting force is reduced due to the increase of the distance between the applied acting force and a stress source, so that the problem that the particle sizes of the dispersed phase at different positions in the oil-water emulsion are different is finally caused.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: a preparation method of a system-stable oil-water emulsion with uniform and controllable particle size comprises the following steps:

s1, preparation of a solution: measuring water and oil reagents required by an experiment according to a proper proportion;

s2, preparing a three-way needle: selecting a 27G flat-head needle head a with a smaller aperture, and nesting a first 21G flat-head needle head b with a larger aperture at the front end of the flat-head needle head a;

s3, preparing emulsion with uniform particle size: injecting the dispersed phase reagent and the continuous phase reagent prepared in the step S1 into a syringe with proper volume respectively, and then arranging the syringe on the micro-flow syringe to be connected with the three-way needle.

Preferably, in S1, a proper emulsifier is selected, such as a water-in-oil solution, i.e. a span-type emulsifier is selected, such as an oil-in-water solution, i.e. a tween-type emulsifier is selected, and a common emulsion preparation method comprises: mechanical stirring, ultrasonic oscillation, homogenizer, etc. The water-in-oil emulsion or the oil-in-water emulsion prepared by the methods has high efficiency in preparing the emulsion by applying external force to the water-oil mixture and dispersing the dispersed phase under the action of the external force to form the emulsion, but the method has no problem that the particle size distribution is not uniform when the external force is applied to the water-oil mixture, mechanical stress or ultrasonic oscillation is not necessarily applied to the water-oil mixture in the emulsion preparation process.

Preferably, in S1, the emulsifier is added to the continuous phase, sonicated to mix the emulsion uniformly, and sonicated to mix the emulsion uniformly, so that the dispersed phase in the emulsion can be kept stable.

Preferably, in the step S2, a hole is punched on the side of the flat-head needle b of the first 21G by a puncher, another flat-head needle c of the second 21G is introduced into the hole, and a plastic tube is connected to the tail of the flat-head needle c of the second 21G to connect the flat-head needle d of the third 21G.

Preferably, in S2, a micro flow tube is externally connected to the front end of the first 21G flat-head needle b to guide the prepared oil-water emulsion.

Preferably, in S2, the joint of the whole tee apparatus is fixed by a hot glue gun to prevent the leakage of the solution during the experiment, water is injected into the tee needle to check the sealing performance, and then the tee needle is immersed in absolute ethanol for ultrasonic cleaning and dried at room temperature, when two immiscible liquids, namely water and oil, are injected into the micro flow tube together by the micro flow injector according to a certain ratio, a dispersed phase liquid with a small volume fraction will form a discontinuous fluid dispersed uniformly in the micro flow tube due to the water-oil interfacial tension and shear force existing inside the mixed liquid system.

Preferably, in S3, the apparatus is set up, the parameters of the syringes are calibrated, the appropriate propulsion speed is adjusted, the liquids in the two syringes are discharged at different speeds, they are merged in the three-way needle to form an emulsion with uniform particle size, and the emulsion is discharged from the micro flow tube, if a certain proportion of emulsifier is added to the continuous phase before mixing. Due to the nature of the emulsifier, the discontinuous fluid in the microflow channel will retain a spherical shape. By the method, the water-oil emulsion with stable system and uniform particle size distribution can be prepared.

The invention provides a preparation method of a stable oil-water emulsion with uniform and controllable particle size, which has the following beneficial effects:

1. the preparation method of the oil-water emulsion with the uniform and controllable particle size and stable system can change the particle size of the dispersed phase in the emulsion by adjusting the proportion of the dispersed phase and the continuous phase or adjusting the propelling speed of the microfluidizer. For example, decreasing the dispersed phase fraction in an oil and water emulsion system, or increasing the continuous phase fraction in an oil and water emulsion system, can decrease the diameter of the dispersed phase globules in the oil and water emulsion.

2. The preparation method of the oil-water emulsion with the uniform and controllable particle size and stable system enables the dispersed phase in the emulsion to exist in a spherical shape stably by adjusting the addition amount of the emulsifier and by means of factors such as shearing force applied to the liquid in a micro-flow tube.

Drawings

FIG. 1 is a schematic diagram of a three-way needle for achieving convergence of aqueous and oil phases as continuous and dispersed phases in an oil-water emulsion in this experiment;

FIG. 2 is a schematic view of the apparatus used to prepare the oil-water emulsion in this experiment.

In the figure: a. a flat head needle of 27G; b. a first 21G flat-head needle; c. a second 21G flat-head needle; d. a third 21G flat-head needle; e. a glass beaker; f. 0.5 mm microflow channels; g. a plastic tube; h. a microfluidic injector.

Detailed Description

The embodiment of the invention provides a preparation method of a system-stable oil-water emulsion with uniform and controllable particle size.

Referring to fig. 1 and 2, the method includes the following steps:

s1, preparation of a solution: measuring water and oil reagents required by an experiment according to a proper proportion;

s2, preparing a three-way needle: selecting a 27G flat-head needle head a with a smaller aperture, and nesting a first 21G flat-head needle head b with a larger aperture at the front end of the flat-head needle head a;

s3, preparing emulsion with uniform particle size: injecting the dispersed phase reagent and the continuous phase reagent prepared in the step S1 into a syringe with proper volume respectively, and then arranging the syringe on the micro-flow syringe to be connected with the three-way needle.

Specifically, the method comprises the following steps: the oil-water emulsion prepared by the invention can keep long-time stability under the environment required by experiments due to the addition of a proper emulsifier, and greatly reduces the possibility of demulsification and delamination. The amount of the added emulsifier is moderate, and if the amount of the added emulsifier is too small, the dispersed phase is difficult to maintain a spherical shape in the oil-water emulsion and is easy to meet and converge, so that demulsification or delamination can be caused. If the dosage of the emulsifier is too large, the viscosity of the whole oil-water emulsion system is too large, the operation such as emulsion preparation is not facilitated, and the waste of experimental materials is caused. Finally, the preparation of different types of oil-water emulsions requires the use of different types of emulsifiers, and the preparation of water-in-oil emulsions, often requires the use of span-type emulsifiers, such as span-80. For the preparation of oil-in-water emulsions, it is generally necessary to use a tween type emulsifier, such as tween-80, and the dispersed phase has a uniform particle size distribution. Because the prepared oil-water emulsion is prepared by the same three-way needle equipment and the micro-flow tube, the particle size of the dispersed phase caused by the uneven distribution of the applied force by other methods such as stirring, homogenization and the like is avoided, and the particle size of the dispersed phase is controllable on the basis of the even distribution of the particle size. The particle size of the dispersed phase in the emulsion can be changed by adjusting the proportion of the dispersed phase and the continuous phase or adjusting the advancing speed of the microfluidizer. For example, decreasing the dispersed phase fraction in an oil and water emulsion system, or increasing the continuous phase fraction in an oil and water emulsion system, can decrease the diameter of the dispersed phase globules in the oil and water emulsion.

Referring again to fig. 1, in S1, a proper emulsifier is selected, such as preparing a water-in-oil solution, i.e., a span-type emulsifier is selected, such as preparing an oil-in-water solution, i.e., a tween-type emulsifier is selected, and in S1, the emulsifier is added to the continuous phase and sonicated to mix it uniformly.

Specifically, the method comprises the following steps: the oil-water emulsion contains a certain proportion of oil phase and water phase which are not mutually soluble. By adjusting the amount of the emulsifier to be added and by means of factors such as shearing force applied to the liquid in the micro flow tube, the dispersed phase in the emulsion can be stably present in a spherical shape.

Referring to fig. 1 again, in S2, a hole is drilled on the side of the flat-head needle b of the first 21G by a puncher, another flat-head needle c of the second 21G is introduced into the hole, a plastic tube is connected to the tail of the flat-head needle c of the second 21G to connect with the flat-head needle d of the third 21G, in S2, a micro-flow pipe is externally connected to the front end of the flat-head needle b of the first 21G to guide the prepared oil-water emulsion, in S2, the joint of the whole tee joint device is fixed by a hot glue gun to prevent the solution leakage in the experimental process, the tee joint needle is filled with water to check the sealing performance, and then the tee joint device is immersed in absolute ethyl alcohol for ultrasonic cleaning and dried at normal temperature.

Specifically, the method comprises the following steps: the dispersed phase and the continuous phase which are not dissolved mutually can be converged according to a certain proportion and then flow out through the micro-flow tube. Due to the shear forces present in the three-way needle-micro-fluidic system and by means of the precise control of the micro-fluidic injector, the dispersed phase can be distributed discontinuously in the continuous phase in a certain proportion and uniformly. And then flows out of the microfluidic tube in this form. Finally, the dispersed phase is stabilized in the continuous phase in a spherical shape by the action of the emulsifier added to the continuous phase.

Referring to fig. 2 again, in S3, the instrument is set, the parameters of the syringes are calibrated, the appropriate propulsion speed is adjusted, and the liquids in the two syringes flow out at different speeds, and are merged in the three-way needle to form an emulsion with uniform particle size, which flows out from the micro flow tube.

Va(mL)	Vb(mL)	Ua(mL/min)	Ub(mL/min)	Da(μm)
					1	5	0.032	0.160	660
1	5	0.020	0.160	378
					1	5	0.016	0.160	313
1	5	0.010	0.160	214
					1	5	0.004	0.160	96
1	10	0.016	0.160	339
					1	10	0.010	0.160	197
1	10	0.004	0.160	83

TABLE 1 particle size variation of dispersed phase in emulsions prepared at different propulsion speeds

Va Capacity of Syringe for injecting dispersed phase reagents

Vb Capacity of injector for injecting continuous phase reagent

Ua speed of advancement of dispersed phase reagent

Rate of advancement of Ub continuous phase reagent

Particle size of continuous phase droplets in Da emulsion

Specifically, the method comprises the following steps: the oil phase and the water phase which are used as raw materials of the oil-water emulsion can flow out of the injector at a constant speed and stably according to a certain proportion by adjusting instrument parameters. The micro-flow injector should not be advanced too fast during the emulsion preparation process. Because the internal diameters of the three-way needle and the micro-flow tube used in the experimental equipment are smaller, the flow velocity which can be realized in unit time is not very large, if the propelling speed is too fast, the liquid pressure in the three-way needle is too high, the equipment is cracked, and particularly, the three-way needle is easy to bounce off from the injector because the pressure is too large at the joint of the injector and the needle. Can lead to experimental failure and even danger.

The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.