阅读说明：本技术 一种膜乳化系统 (Membrane emulsification system ) 是由 黄庆林 黄岩 宋亮 肖长发 于 2019-10-21 设计创作，主要内容包括：本发明公开了一种膜乳化系统,包括分散相储液罐、膜组件、连续相储液罐、乳液收集罐,所述膜组件中的微孔膜丝采用聚四氟乙烯中空纤维膜或聚全氟乙丙烯中空纤维膜,分散相送料管路的一端通入分散相储液罐内的液面以下,另一端经膜组件的入口端盖与各微孔膜丝的入口端连通,在分散相送料管路上安装分散相流动装置；分散相回流管路的一端经出口端盖与各微孔膜丝的出口端连通,另一端伸入分散相储液罐内；连续相经连续相送料管和膜组件上的连续相入口送入连续相腔体内,在连续相送料管上安装连续相流动装置；膜组件上的乳液排出口与乳液排出管的一端连接,乳液排出管另一端伸入乳液收集罐内。该系统制得的乳液粒径分布较窄、粒径可控、稳定性高。(The invention discloses a membrane emulsification system, which comprises a disperse phase liquid storage tank, a membrane component, a continuous phase liquid storage tank and an emulsion collection tank, wherein microporous membrane filaments in the membrane component adopt polytetrafluoroethylene hollow fiber membranes or fluorinated ethylene propylene hollow fiber membranes, one end of a disperse phase feeding pipeline is introduced below the liquid level in the disperse phase liquid storage tank, the other end of the disperse phase feeding pipeline is communicated with the inlet end of each microporous membrane filament through an inlet end cover of the membrane component, and a disperse phase flowing device is arranged on the disperse phase feeding pipeline; one end of the disperse phase return pipeline is communicated with the outlet end of each microporous membrane wire through an outlet end cover, and the other end of the disperse phase return pipeline extends into the disperse phase liquid storage tank; the continuous phase is fed into the continuous phase cavity through a continuous phase feeding pipe and a continuous phase inlet on the membrane module, and a continuous phase flow device is arranged on the continuous phase feeding pipe; the emulsion outlet on the membrane component is connected with one end of an emulsion discharge pipe, and the other end of the emulsion discharge pipe extends into the emulsion collection tank. The emulsion prepared by the system has narrow particle size distribution, controllable particle size and high stability.)

1. A membrane emulsification system comprises a dispersed phase liquid storage tank, a dispersed phase flow device, a membrane component, a continuous phase liquid storage tank, a continuous phase flow device and an emulsion collection tank, and is characterized in that: also comprises a first flowmeter, a first valve, a second valve and a pressure gauge 4,

the membrane assembly comprises a cylindrical shell and a plurality of microporous membrane filaments arranged in parallel in the shell, wherein two ends of each microporous membrane filament are fixed by resin for packaging two ends of the shell; an inlet end cover and an outlet end cover are respectively connected with two ends of the shell, and spaces for containing the dispersed phase are formed among the inlet end cover, the outlet end cover and the two ends of the shell; a continuous phase cavity is formed between the shell and the microporous membrane yarn, a continuous phase inlet is formed on the shell close to the outlet side of the microporous membrane yarn, and an emulsion outlet is formed on the shell close to the inlet side of the microporous membrane yarn;

one end of a dispersed phase feeding pipeline is communicated below the dispersed phase liquid level in the dispersed phase liquid storage tank, the other end of the dispersed phase feeding pipeline is communicated with the inlet end of each microporous membrane wire through the inlet end cover, and the dispersed phase flowing device is installed on the dispersed phase feeding pipeline; one end of a disperse phase return pipeline is communicated with the outlet end of each microporous membrane wire through the outlet end cover, the other end of the disperse phase return pipeline extends into the disperse phase liquid storage tank, and the pressure gauge, the first valve and the first flow meter are sequentially installed on the disperse phase return pipeline along the flow direction of disperse phases;

the continuous phase liquid storage tank is internally filled with a continuous phase, the continuous phase is fed into the continuous phase cavity through the continuous phase feeding pipe and the continuous phase inlet, and the continuous phase flow device and the second valve are installed on the continuous phase feeding pipe;

the emulsion discharge port is connected with one end of an emulsion discharge pipe, and the other end of the emulsion discharge pipe extends into the emulsion collection tank;

the microporous membrane wire adopts a polytetrafluoroethylene hollow fiber membrane or a fluorinated ethylene propylene hollow fiber membrane, and the average aperture range of the membrane is 0.1-10 microns.

2. The membrane emulsification system of claim 1, wherein: the outer diameter of each microporous membrane wire is 1.8-2.2mm, the inner diameter is 0.5-1.4mm, and the distance between each microporous membrane wire and the adjacent microporous membrane wire is 0.2-1 cm.

3. The membrane emulsification system according to claim 1 or 2, wherein: the continuous phase is an oil phase containing a surfactant or a high polymer monomer.

4. The membrane emulsification system of claim 3, wherein: the oil phase is one or a mixture of more of dichloromethane, chloroform, ethyl chloride, dichloroethane, trichloroethane and the like, kerosene, diesel oil, toluene, ethyl acetate, ethyl formate, diethyl ether, cyclohexane and benzyl alcohol which are mixed in any proportion; the surfactant is sorbitan monooleate, sodium dodecyl benzene sulfonate or sodium dodecyl sulfate, and the dosage of the surfactant is 0.01 to 3 weight percent of the oil phase; the high polymer monomer is trimesoyl chloride, adipoyl chloride or toluene diisocyanate, and the dosage of the high polymer monomer is 0.01 to 2 weight percent of the oil phase.

5. The membrane emulsification system of claim 4, wherein: the dispersed phase is water, or one or a mixed solution of a plurality of water-phase polymer monomers, film forming agents and thickening agents which are mixed in any proportion.

6. The membrane emulsification system according to claim 5, wherein the water phase polymer monomer is m-phenylenediamine, piperazine, hexanediamine or tetraethylenepentamine in an amount of 0.1-8 wt% of the water phase; the film forming agent is polyvinyl alcohol, polypropylene alcohol, gelatin, Arabic gum, hyaluronic acid, pectin or carrageenan; the thickener is gelatin, starch, carrageenan, sodium alginate, chitosan or fructose.

7. The membrane emulsification system of claim 6, wherein: and a second flowmeter is also arranged on the emulsion discharge pipe.

8. The membrane emulsification system of claim 7, wherein: the dispersed phase flow device and the continuous phase flow device are pressure pumps or peristaltic pumps, and the pressure range of the pumps is 0.01-0.6 MPa.

9. The membrane emulsification system of claim 8 wherein the dispersed phase reservoir, the continuous phase reservoir and the emulsion collection reservoir are each equipped with a stirring device, the stirring device being a magnetic stirrer or an electric stirrer; and cooling and heating devices for adjusting the temperature are also arranged in the dispersed phase liquid storage tank and the continuous phase liquid storage tank.

10. The polytetrafluoroethylene hollow fiber membrane and the polyfluorinated ethylene propylene hollow fiber membrane are applied to a membrane emulsification system.

Technical Field

The invention relates to the field of membrane emulsification, in particular to a membrane emulsification system.

Background

An emulsion is a dispersion of two or more mutually immiscible liquids, at least one of which is present in the continuous phase in the form of droplets. There are two main types of emulsions, namely oil-in-water (O/W) and water-in-oil (W/O). The emulsification process plays a very important role in many fields such as cosmetics, foods, medicines, etc. The traditional emulsification method mainly comprises a high-pressure shearing method, an ultrasonic dispersion method, high-speed stirring and the like, the size of dispersed phase droplets depends on the crushing degree of eddy shearing force generated by input mechanical energy to the dispersed phase, and the defects of wide particle size distribution, difficult control of particle size, high energy consumption, poor experimental repeatability and the like of the dispersed phase droplets exist.

The membrane emulsification technique has attracted much attention since the 90 s in the 20 th century and is considered to be a simple and effective method for preparing monodisperse emulsions. In the membrane emulsification process, a dispersion phase and a continuous phase are distributed at two sides of a microporous membrane, the dispersion phase forms droplets on the surface of the other side of the membrane after passing through the micropores under the action of pressure and grows, and when the diameter of the droplets reaches a certain critical value, the droplets are peeled from the surface of the membrane under the action of the shearing force of the continuous phase flowing at high speed, so that an oil-in-water or water-in-oil emulsion is formed. The membrane emulsification is characterized in that the size of dispersed phase liquid drops is controlled by the pore size and distribution of the microporous membrane to be monodisperse, and compared with the conventional emulsion preparation method, the membrane emulsification has the advantages of low energy consumption, mild preparation conditions, small emulsifier dosage and the like.

The most common membrane emulsion is a Porous Glass membrane SPG (Shirasu Porous Glass membrane). However, porous glass membranes are poorly hydrophobic and alkali resistant, fragile, and poorly flexible, limiting their development and further use.

Chinese patent publication No. CN107376669A discloses a preparation method of a perfluoropolymer hollow fiber composite membrane, and the prepared hollow fiber composite membrane can be used for wastewater treatment under severe conditions; chinese patent publication No. CN110180401A discloses a method for preparing a perfluoropolymer hollow fiber membrane, which is widely used in the fields of water treatment, food, petrochemical industry, medicine, etc. as a separation membrane. However, in the field of membrane emulsification, no report is found on the application of perfluoropolymer hollow fiber membranes.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a membrane emulsification system adopting a perfluoropolymer hollow fiber membrane.

Therefore, the technical scheme of the invention is as follows:

a membrane emulsification system comprises a dispersed phase liquid storage tank, a dispersed phase flow device, a membrane assembly, a continuous phase liquid storage tank, a continuous phase flow device, an emulsion collection tank, a first flowmeter, a first valve, a second valve and a pressure gauge. The membrane assembly comprises a cylindrical shell and a plurality of microporous membrane filaments arranged in parallel in the shell, wherein two ends of each microporous membrane filament are fixed by resin for packaging two ends of the shell; an inlet end cover and an outlet end cover are respectively connected with two ends of the shell, and spaces for containing the dispersed phase are formed among the inlet end cover, the outlet end cover and the two ends of the shell; a continuous phase cavity is formed between the shell and the microporous membrane yarn, a continuous phase inlet is formed on the shell close to the outlet side of the microporous membrane yarn, and an emulsion outlet is formed on the shell close to the inlet side of the microporous membrane yarn; one end of a dispersed phase feeding pipeline is communicated below the dispersed phase liquid level in the dispersed phase liquid storage tank, the other end of the dispersed phase feeding pipeline is communicated with the inlet end of each microporous membrane wire through the inlet end cover, and the dispersed phase flowing device is installed on the dispersed phase feeding pipeline; one end of a disperse phase return pipeline is communicated with the outlet end of each microporous membrane wire through the outlet end cover, the other end of the disperse phase return pipeline extends into the disperse phase liquid storage tank, and the pressure gauge, the first valve and the first flow meter are sequentially installed on the disperse phase return pipeline along the flow direction of disperse phases; the continuous phase liquid storage tank is internally filled with a continuous phase, the continuous phase is fed into the continuous phase cavity through the continuous phase feeding pipe and the continuous phase inlet, and the continuous phase flow device and the second valve are installed on the continuous phase feeding pipe; the emulsion discharge port is connected with one end of an emulsion discharge pipe, and the other end of the emulsion discharge pipe extends into the emulsion collection tank; the microporous membrane wire adopts a polytetrafluoroethylene hollow fiber membrane or a fluorinated ethylene propylene hollow fiber membrane, and the aperture of the membrane is 0.1-10 microns.

Preferably, each microporous membrane filament has an outer diameter of 1.8 to 2.2mm and an inner diameter of 0.5 to 1.4mm, and the distance between each microporous membrane filament and the adjacent microporous membrane filament is 0.2 to 1cm (the distance between the outer surfaces of the membrane filaments).

Wherein the continuous phase is an oil phase containing a surfactant or a high polymer monomer. The oil phase is one or a mixture of more of dichloromethane, chloroform, ethyl chloride, dichloroethane, trichloroethane and the like, kerosene, diesel oil, toluene, ethyl acetate, ethyl formate, diethyl ether, cyclohexane and benzyl alcohol which are mixed in any proportion; the surfactant is sorbitan monooleate, sodium dodecyl benzene sulfonate or sodium dodecyl sulfate, and the dosage of the surfactant is 0.01 to 3 weight percent of the oil phase; the high polymer monomer is trimesoyl chloride, adipoyl chloride or toluene diisocyanate, and the dosage of the high polymer monomer is 0.01 to 2 weight percent of the oil phase.

The dispersed phase is water, or one or a mixed solution of a plurality of water-phase polymer monomers, film forming agents and thickening agents which are mixed in any proportion.

The water-phase polymer monomer is m-phenylenediamine, piperazine, hexamethylene diamine or tetraethylenepentamine, and the using amount of the water-phase polymer monomer is 0.1-8 wt% of the water phase; the film forming agent is polyvinyl alcohol, polypropylene alcohol, gelatin, Arabic gum, hyaluronic acid, pectin or carrageenan; the thickener is gelatin, starch, carrageenan, sodium alginate, chitosan or fructose.

Preferably, a second flowmeter is further mounted on the emulsion discharge pipe.

The dispersed phase flow device and the continuous phase flow device can be pressure pumps or peristaltic pumps, and the pressure range of the pumps is 0.01-0.6 MPa.

In addition, stirring devices are arranged in the dispersed phase liquid storage tank, the continuous phase liquid storage tank and the emulsion collection tank, and the stirring devices are magnetic stirrers or electric stirrers; and cooling and heating devices for adjusting the temperature are also arranged in the dispersed phase liquid storage tank and the continuous phase liquid storage tank.

Compared with the prior art, the invention has the following beneficial effects:

(1) the hollow fiber membrane adopted by the membrane emulsification system is a perfluoropolymer hollow fiber membrane with stable and strong hydrophobicity, has narrow membrane pore size distribution, is acid-base resistant, high temperature resistant, organic solvent resistant, and stable and strong hydrophobicity, and makes up the defects of poor alkali resistance and hydrophobicity and the like of the conventional SPG membrane;

(2) the average pore size range of the polytetrafluoroethylene porous membrane and the polyperfluorinated ethylene propylene porous membrane is 0.1-10 micrometers, the transmembrane pressure is adjusted according to membranes with different pore sizes, emulsions with different particle sizes can be prepared, nano-scale emulsions can be obtained, and the polymer emulsion is resistant to acid and alkali corrosion and wider in application range.

(3) When the membrane emulsification system is used for preparing emulsion, the dispersed phase transmembrane pressure can be accurately adjusted by adopting a circulating flow mode through a valve and a stable pressure supply device, the stability of the transmembrane pressure is improved, and the uniformity of the droplet particle size in the membrane emulsification process is ensured. Compared with the traditional methods such as high-speed mechanical stirring, the method has the advantages of narrow liquid particle size distribution, low energy consumption, small dosage of the surfactant and high repeatability.

(4) The invention adopts a stirring and cross flow mode, the shearing action of the membrane surface is strong and controllable, the drop of the liquid drops is facilitated, the fusion of the liquid drops is avoided, and the particle size of the liquid drops can be regulated and controlled by regulating and controlling the shearing strength of the membrane surface.

(5) The system of the invention has the advantages of high yield of water-in-oil emulsion, simple process, easy operation and short reaction time, can be used for preparing the water-in-oil emulsion, embedding bioactive substances or unstable medicaments and the like, is suitable for industrial production, and has small volume of membrane emulsification equipment and simple and portable structure.

(6) The emulsion prepared by the system has narrow particle size distribution, controllable particle size and high stability.

Drawings

FIG. 1 is a schematic diagram of the structure of a membrane emulsification system of the present invention;

FIG. 2 is an electron microscope image of the outer surface of a fluorinated ethylene propylene hollow fiber membrane used in example 1 of the present invention;

FIG. 3 is an electron microscope image of the outer surface of a polytetrafluoroethylene hollow fiber membrane used in example 3 of the invention;

FIG. 4 is an optical microscope photograph of a water-in-oil emulsion obtained in example 1 of the present invention.

In the figure:

1-a dispersed phase liquid storage tank, 2-a dispersed phase flow device, 3 a-a first valve, 3 b-a second valve, 4-a pressure gauge, 5-a membrane component, 6 a-a first flowmeter, 6 b-a second flowmeter, 7-a continuous phase liquid storage tank and 8-an emulsion collection tank; 9-continuous phase flow device.

Detailed Description

In the present invention, the polytetrafluoroethylene hollow fiber membrane and the polyperfluoroethylpropylene hollow fiber membrane used in the membrane module are prepared by the methods disclosed in chinese patent publication nos. CN 103776669a and CN110180401A, the entire contents of which are incorporated in this document by reference.

The membrane emulsification system of the present invention will be described in detail with reference to the accompanying drawings and specific examples.

Referring to fig. 1, a membrane emulsification system of the present invention comprises a dispersed phase reservoir 1, a dispersed phase flow device 2, a membrane module 5, a continuous phase reservoir 7, a continuous phase flow device 9, an emulsion collection tank 8, a first flow meter 6a, first and second valves 3a, 3b, and a pressure gauge 4. The concrete structure is as follows:

the membrane module 5 comprises a cylindrical shell 5a and a plurality of microporous membrane filaments 5b arranged in parallel in the shell, wherein two ends of the microporous membrane filaments are fixed by resin for encapsulating the two ends of the shell. An inlet end cover 5c and an outlet end cover 5d are respectively connected to two ends of the shell, and spaces for containing the dispersed phase are formed among the inlet end cover, the outlet end cover and the two ends of the shell. A continuous phase chamber is formed between the casing 5a and the microporous membrane yarn 5b, a continuous phase inlet 7a is formed in the casing on the side close to the outlet of the microporous membrane yarn, and an emulsion outlet 8a is formed in the casing on the side close to the inlet of the microporous membrane yarn. One end of the dispersed phase feeding pipeline is communicated below the dispersed phase liquid level in the dispersed phase liquid storage tank 1, the other end of the dispersed phase feeding pipeline is communicated with the inlet end of each microporous membrane wire through the inlet end cover 5c, and the dispersed phase flowing device 2 is installed on the dispersed phase feeding pipeline. One end of the disperse phase return pipeline is communicated with the outlet end of each microporous membrane wire through the outlet end cover, the other end of the disperse phase return pipeline extends into the disperse phase liquid storage tank 1, and the pressure gauge 4, the first valve 3a and the first flow meter 6a are sequentially arranged on the disperse phase return pipeline along the disperse phase flow direction. The continuous phase liquid storage tank 7 is internally filled with a continuous phase, the continuous phase is fed into the continuous phase cavity through the continuous phase feeding pipe and the continuous phase inlet, and the continuous phase flow device 9 and the second valve 3b are installed on the continuous phase feeding pipe. The emulsion discharge port is connected with one end of an emulsion discharge pipe, and the other end of the emulsion discharge pipe extends into the emulsion collection tank 8.

In the system, the dispersed phase and the mobile phase adopt a cross-flow/counter-flow mode, so that the shearing action of the membrane surface is stronger, the drop of the liquid drops is facilitated, and the particle size of the liquid drops can be regulated and controlled by regulating and controlling the shearing strength of the membrane surface.

In the system, the microporous membrane wire adopts a polytetrafluoroethylene hollow fiber membrane or a fluorinated ethylene propylene hollow fiber membrane. Preferably, the outer diameter of each microporous membrane wire is 1.8-2.2mm, and the inner diameter is 0.5-1.4 mm; the distance between the microporous membrane filaments is 0.2-1cm to avoid droplet fusion; the pore diameter of the membrane is 0.1-10 microns.

The continuous phase in the above system is an oil phase containing a surfactant or a high polymer monomer. The oil phase is one or a mixture of more of dichloromethane, chloroform, ethyl chloride, dichloroethane, trichloroethane and the like, kerosene, diesel oil, toluene, ethyl acetate, ethyl formate, diethyl ether, cyclohexane and benzyl alcohol which are mixed in any proportion; the surfactant is sorbitan monooleate, sodium dodecyl benzene sulfonate or sodium dodecyl sulfate, and the dosage of the surfactant is 0.01 to 3 weight percent of the oil phase; the high polymer monomer is trimesoyl chloride, adipoyl chloride or toluene diisocyanate, and the dosage of the high polymer monomer is 0.01 to 2 weight percent of the oil phase.

The dispersed phase is water, or one or a mixed solution of a plurality of water-phase polymer monomers, film forming agents and thickening agents which are mixed in any proportion. Wherein the water-phase polymer monomer is m-phenylenediamine, piperazine, hexamethylene diamine or tetraethylenepentamine, and the using amount of the water-phase polymer monomer is 0.1-8 wt% of the water phase; the film forming agent is polyvinyl alcohol, polypropylene alcohol, gelatin, Arabic gum, hyaluronic acid, pectin or carrageenan; the thickener is gelatin, starch, carrageenan, sodium alginate, chitosan or fructose.

Further, a second flow meter 6b is attached to the emulsion discharge pipe. The dispersed phase flow device and the continuous phase flow device can be pressure pumps or peristaltic pumps, and the pressure range of the pumps is 0.01-0.6 MPa. Stirring devices are further arranged in the dispersed phase liquid storage tank, the continuous phase liquid storage tank and the emulsion collecting tank 8, so that the stirring speed can be controlled, and the stirring devices are magnetic stirrers or electric stirrers. Cooling and heating devices can be further installed in the dispersed phase liquid storage tank and the continuous phase liquid storage tank, so that the temperature in each liquid storage tank can be adjusted according to actual needs, and the emulsifying effect is better.

The process for preparing the emulsion using the emulsification system of the present invention is as follows:

injecting the prepared water phase solution into the dispersed phase liquid storage tank, injecting the prepared oil phase solution into the continuous phase liquid storage tank, opening the valve, each stirring device and the dispersed phase and continuous phase flow devices, adjusting the flow rate and pressure, and allowing the water phase to form liquid drops through the membrane holes to enter the continuous oil phase under the action of the pressure to obtain the uniform water-in-oil emulsion.