Patent Application
20200306715
The present invention relates to porous polymer microspheres. More particularly, the invention relates to porous polymer microspheres with optical anisotropy, method of manufacturing the same and application of the same.
Microspheres, comprising inorganic or organic macromolecular materials, may be of sizes of nanometers to micrometers and of spherical shapes or other similar shapes with various interior structures, including solid structures, hollow structures, porous structures, core-shell structures, yolk structures and other structures. Moreover, organic polymer microspheres can be mainly divided into natural polymer microspheres and synthetic polymer microspheres. Due to their special sizes, diverse interior structures and peculiar functions, polymer microspheres are widely applied in biochemical separation, reaction catalysis, biochemical detection, electronic information, drug release or other fields. One of most important applications is chromatography in biochemical separation.
Widely used to separate and purify various materials: from small molecules to macromolecules, or from synthetic polymers to natural materials, chromatography has become an effective separation method. In the method, the stationary phase is usually filled into the column by a packing method, and then the mobile phase containing a product to be separated is introduced into the column. Depending on the interaction between the product and the stationary phase, the time it takes for the product flowing out of the column with mobile phase is different, thus achieving the purpose of separation. The materials constituting the stationary phase can be of organic and inorganic, where organic material is mainly composed of natural sugars and polymers and inorganic material is mainly silica. Among the organic packing materials, polymers become very important options in chromatography, due to their excellent chemical and physical stability and the ability to achieve various separation modes by introducing different functional groups and different structures.
In order to increase producitivy and reduce cost, polymer microparticles of uniform particles size are commonly used in the industry as chromatography stationary phase. There are many methods for preparing polymer microspheres, such as emulsion polymerization, dispersion polymerization, single coacervation, and complex coacervation. The current production process has been able to prepare cross-linked polymer microspheres with a relatively uniform particle size and a certain mechanical strength, as disclosed in Chinese patent application CN106633168A and patent CN103374143B. However because of their irregular interior pores, when the polymer microspheres are applied to the chromatography process, the mobile phase may have an unfavorable diffusion effect, and further the separation result may be affected. How to control the interior molecular structure, interior pore structure and orientation has become one of the research hotspots to improve the performance of stationary phase in recent years.
Therefore, there remains a need for providing porous polymer microspheres, which have a uniform and controllable size, a regular interior structure, and a pore distribution as well as an easily operated manufacture method, to improve separation efficiency of the chromatographic column and thus save separation time.
In order to fulfill the above mentioned need, one objective of the present invention is to provide porous polymer microspheres having radial optical anisotropy, wherein the porous polymer microspheres have diverse swelling states when dispersed in different solvent which have ability to well swell the porous polymer microspheres.
In some preferred embodiments, the solvent is THF, toluene or ethanol.
In some preferred embodiments, the average particle size of the porous polymer microspheres in ethanol is 1 μm-150 μm.
In some embodiments, the swelling degree of the porous polymer microspheres in THF is 1.0-7.0.
Another objective of the present invention is to provide a method for preparing the porous polymer microspheres, comprising the following steps: (I) forming a homogeneous liquid crystal mixture, wherein the liquid crystal mixture comprises at least one reactive liquid crystal compound, at least one non-reactive liquid crystal compound and at least one polymerization initiator; (II) dispersing the liquid crystal mixture into a continuous phase containing liquid-crystal-configuration-adjusting agent through a membrane emulsification device to form a emulsion of liquid crystal droplets, wherein the liquid-crystal-configuration-adjusting agent align liquid crystal molecules inside the liquid crystal droplets along the radial direction; (III) polymerizing the at least one reactive liquid crystal compound to form intermediate microspheres; (IV) removing the at least one non-reactive liquid crystal compound from the intermediate microspheres to form the porous polymer microspheres; (V) separating, washing and dispersing or drying the porous polymer microspheres.
In some preferred embodiments, the way of polymerizing includes photo polymerization, thermal polymerization and radiation polymerization. In more preferred embodiments, the way of polymerizing is photo polymerization.
In some preferred embodiment, the at least one reactive liquid crystal compound is 5%-50% by weight of the liquid crystal mixture.
In some preferred embodiments, the at least one non-reactive liquid crystal compound is nematic liquid crystal.
In some preferred embodiments, the liquid-crystal-configuration-adjusting agent is SDS, NaI or NaClO4. In more preferred embodiments, the liquid-crystal-configuration-adjusting agent is SDS, and the concentration of SDS in the continuous phase is 1 mM to 200 mM.
In some preferred embodiments, the continuous phase is water or a water-miscible system.
Another objective of the present invention is to provide an application of the porous polymer microspheres as the stationary phase in chromatograph separation.
The present invention utilizes a liquid-crystal-assisted template polymerization method to prepare porous polymer microparticles with controlled sizes. Because of the porous structure and the swell property in solutions, the polymer microspheres may be used as the stationary phase of chromatograph separation, improving both separation efficiency and packing efficiency of the column. Meanwhile, the porous polymer microparticles have radial optical anisotropy, indicating their ordered interior structures. Since the space order of polymer molecules will involve in the separation process, the porous polymer microspheres as the stationary phase provide a better separation effect for a mixture of components with similar boiling point and polarities but different structures, but cause no adverse diffusion effects on the mobile phase.
These and other features and advantages of the present invention will be better understood by reference to the following detailed description of an illustrative embodiment of the present disclosure when read in conjunction with the accompanying drawings, wherein:
The following description of the disclosed embodiments is provided in detail to enable any person skilled in the art to fully understand the present invention. However, it will be apparent to those skilled in the art to readily make or use the present invention without these specific details. In other examples, well-known structures and devices are shown in the block diagram. In this regard, the description of the different illustrative exemplary embodiments presented herein are for the purpose of illustration and description and are not intended to be exhaustive or limited to the inventive concept. Accordingly, the scope of the invention is not to be limited by the specific embodiments described above, and is subject only to the scope of the appended claims.
Abbreviations used in the present invention are listed below:
SPG membrane: Shirasu Porous Glass membrane
SDS: sodium dodecyl sulfate
THF: tetrahydrofuran.
Referring first to
Porous polymer microspheres with a radial optical anisotropy can be prepared by a liquid-crystal-assisted template polymerization method, including the following steps: First, at least one reactive liquid crystal, at least one non-reactive liquid crystal, and at least one polymerization initiator are mixed in a certain ratio to form a uniform liquid crystal mixture. The reactive liquid crystal compounds contain polymerizable groups and can be further polymerized in the presence of polymerization initiators, such as acrylate type liquid crystals (RM257), methacrylate type liquid crystals (HCM062), allyl type liquid crystals (HCM126) and so on. The non-reactive liquid crystal compounds do not have polymerizable groups to further polymerize. The non-reactive liquid crystal may be a nematic liquid crystal, a cholesteric liquid crystal, a smectic liquid crystal, and other liquid crystals without polymerizable groups. The mass ratio of the reactive liquid crystal compound over the liquid crystal mixture varies from 0.05 to 0.50.
After that, the liquid crystal mixture is passed through a membrane emulsification device into a continuous phase to form monodisperse liquid crystal droplets. The continuous phase can be water. The principle of the membrane emulsifier device is shown in
Next, the reactive liquid crystals 11 in the liquid crystal droplets are polymerized to form intermediate microspheres containing the unreacted non-reactive liquid crystals 12. As shown in
Then porous polymer microparticles are further formed by removing the unreacted non-reactive liquid crystals. As shown in
Finally, the polymer microspheres are separated, washed and dispersed/dried. Because the polymer microspheres have different swelling states in different solvents, the polymer microspheres at dry and in solvents have different particle sizes and morphologies. In the following examples, the polymer microspheres in ethanol have a particle size from 1 μm to 150 μm.
The dried polymer microparticles can be applied in biochemical separation as the stationary phase of chromatography. Chromatography is usually carried out by a column operation, where the polymer microparticles are packed in the column and a mobile phase containing different components is passed through the column. Due to the porous structure, the solvent-dependent swelling degree and the special and regular interior structure, the polymer microparticles, as the stationary phase, have different interaction with various substances as well as different combination levels, achieving the purpose of substance separation.
In the present invention, the ratios all refer to mass ratios, unless otherwise indicated.
First, 7.9 g of 5CB (non-reactive liquid crystal) compound 5CB, 2 g of RM257 (reactive liquid crystal), and 0.1 g of DMPAP (photo polymerization initiator) were mixed and heated above the clearing point of the liquid crystals to form a homogeneous solution. After that, the solution was sufficiently shaken to be uniformly blended and then slowly cooled to room temperature, forming a liquid crystal mixture. Since DMPAP is sensitive to light, the solution must be placed in dark during the cooling process. 100 mg of the above uniform liquid crystal mixture was slowly and smoothly passed through a membrane emulsifier device with a membrane pore diameter of 2.8 μm under a pressure of 0.030 MPa, and dispersed into 275 ml of mM SDS aqueous solution (water is the continuous phase, SDS is the liquid-crystal-configuration-adjusting agent). The prepared liquid crystal droplets are uniform in size which is averagely 10 μm (as shown in
A liquid crystal mixture (40% RM257, 1% DMPAP) was prepared as example 1. Then 10 g of the liquid crystal mixture was slowly and smoothly passed through a membrane emulsifier device with a membrane pore size of 10 μm under a pressure of 0.030 MPa, and dispersed in 275 mL of 2 mM SDS aqueous solution (water is the continuous phase, SDS is the liquid-crystal-configuration-adjusting agent) to form an emulsion containing liquid crystal droplets with a uniform size and a radial configuration. After that, the emulsion was placed under a UV light source to process polymerization. The radiation intensity was 2.5 mW/cm2, and the time was 30 minutes. The system needs to be constantly stirred during the polymerization. After the polymerization, the reaction solution was washed with ethanol and then centrifuged (8000 rpm, 10 minutes) to remove the supernatant. After repeating the washing and centrifugation three times, the ethanol was removed to obtain polymer microspheres without 5CB, and then the polymer microspheres were dispersed in different solvents. The polymer microspheres may also be dried for further applications. As shown in
A liquid crystal mixture (20% RM257, 1% DMPAP) was prepared as example 1. Then 10 g of the liquid crystal mixture was slowly and smoothly passed through a membrane emulsifier device with a membrane pore size of 10 μm under a pressure of 0.030 MPa, and dispersed in 275 mL of 78 mM SDS aqueous solution (water is the continuous phase, SDS is the liquid-crystal-configuration-adjusting agent) to form an emulsion containing liquid crystal droplets with a uniform size and a radial configuration. After that, the emulsion was placed under a UV light source to process polymerization. The radiation intensity was 2.5 mW/cm2, and the time was 30 minutes. The system needs to be constantly stirred during the polymerization. After the polymerization, the reaction solution was washed with ethanol and then centrifuged (8000 rpm, 10 minutes) to remove the supernatant. After repeating the washing and centrifugation three times, the ethanol was removed to obtain polymer microspheres without 5CB, and then the polymer microspheres were dispersed in different solvents. The polymer microspheres may also be dried for further applications. As shown in
A liquid crystal mixture (20% RM257, 1% DMPAP) was prepared as example 1. Then 10 g of the liquid crystal mixture was slowly and smoothly passed through a membrane emulsifier device with a membrane pore size of 20 μm under a pressure of 0.030 MPa, and dispersed in 275 mL of 2 mM SDS aqueous solution (water is the continuous phase, SDS is the liquid-crystal-configuration-adjusting agent) to form an emulsion containing liquid crystal droplets with a uniform size and a radial configuration. After that, the emulsion was placed under a UV light source to process polymerization. The radiation intensity was 2.5 mW/cm2, and the time was 30 minutes. The system needs to be constantly stirred during the polymerization. After the polymerization, the reaction solution was washed with ethanol and then centrifuged (8000 rpm, 10 minutes) to remove the supernatant. After repeating the washing and centrifugation three times, the ethanol was removed to obtain polymer microspheres without 5CB, and then the polymer microspheres were dispersed in different solvents. The polymer microspheres may also be dried for further applications. As shown in
A liquid crystal mixture (20% RM257, 1% DMPAP) was prepared as example 1. Then 10 g of the liquid crystal mixture was slowly and smoothly passed through a membrane emulsifier device with a membrane pore size of 2.8 μm under a pressure of 0.030 MPa, and dispersed in 275 mL of 160 mM SDS aqueous solution (water is the continuous phase, SDS is the liquid-crystal-configuration-adjusting agent) to form an emulsion containing liquid crystal droplets with a uniform size and a radial configuration. After that, the emulsion was placed under a UV light source to process polymerization. The radiation intensity was 2.5 mW/cm2, and the time was 30 minutes. The system needs to be constantly stirred during the polymerization. After the polymerization, the reaction solution was washed with ethanol and then centrifuged (8000 rpm, 10 minutes) to remove the supernatant. After repeating the washing and centrifugation three times, the ethanol was removed to obtain polymer microspheres without 5CB, and then the polymer microspheres were dispersed in different solvents. The polymer microspheres may also be dried for further applications. As shown in
A liquid crystal mixture (10% RM257, 1% DMPAP) was prepared as example 1. Then 10 g of the liquid crystal mixture was slowly and smoothly passed through a membrane emulsifier device with a membrane pore size of 10 μm under a pressure of 0.030 MPa, and dispersed in 275 mL of 2 mM SDS aqueous solution (water is the continuous phase, SDS is the liquid-crystal-configuration-adjusting agent) to form an emulsion containing liquid crystal droplets with a uniform size and a radial configuration. After that, the emulsion was placed under a UV light source to process polymerization. The radiation intensity was 2.5 mW/cm2, and the time was 30 minutes. The system needs to be constantly stirred during the polymerization. After the polymerization, the reaction solution was washed with ethanol and then centrifuged (8000 rpm, 10 minutes) to remove the supernatant. After repeating the washing and centrifugation three times, the ethanol was removed to obtain polymer microspheres without 5CB, and then the polymer microspheres were dispersed in different solvents. The polymer microspheres may also be dried for further applications. As shown in
A liquid crystal mixture (20% RM257, 1% DMPAP) was prepared as example 1. Then 10 g of the liquid crystal mixture was slowly and smoothly passed through a membrane emulsifier device with a membrane pore size of 50 μm under a pressure of 0.030 MPa, and dispersed in 275 mL of 2 mM SDS aqueous solution (water is the continuous phase, SDS is the liquid-crystal-configuration-adjusting agent) to form an emulsion containing liquid crystal droplets with a uniform size and a radial configuration. After that, the emulsion was placed under a UV light source to process polymerization. The radiation intensity was 2.5 mW/cm2, and the time was 30 minutes. The system needs to be constantly stirred during the polymerization. After the polymerization, the reaction solution was washed with ethanol and then centrifuged (8000 rpm, 10 minutes) to remove the supernatant. After repeating the washing and centrifugation three times, the ethanol was removed to obtain polymer microspheres without 5CB, and then the polymer microspheres were dispersed in different solvents. The polymer microspheres may also be dried for further applications. As shown in
In addition, for the purpose of concise illustration, the drawings herein are described in terms of a substantially planar form. However, it should be understood by those skilled in the art that the rearview mirror (and all of its functional layers) of the present invention may also include concave and convex curved surfaces, such as cylinders, spheres, ellipsoids, parabolas, or their combination. In addition, it will be appreciated by those skilled in the art that the rearview mirror of the present invention may also be applied to a combined rearview mirror system which has two or more different mirrors with different reflection directions or curvature characteristics.
While several particular exemplary embodiments have been described above in detail, the disclosed embodiments are considered illustrative rather than limiting. Those skilled in the art will readily realize that alternatives, modifications, variations, improvements, and substantial equivalents are possible without substantially departing from the novelty spirits or scope of the present disclosure. Thus, all such alternatives, modifications, variations, improvements, and substantial equivalents are intended to be embraced within the scope of the present disclosure as defined by the appended claims.
The method of the present invention can be applied to the field of polymer.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201711420820.6 | Dec 2017 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2018/122320 | 12/20/2018 | WO | 00 |
