CN111019186A - Ordered porous structure material based on common crystalline polymer and preparation method thereof - Google Patents
Ordered porous structure material based on common crystalline polymer and preparation method thereof Download PDFInfo
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Abstract
The invention provides an ordered porous structure material based on a common crystalline polymer and a preparation method thereof, belonging to the technical field of ordered porous structure material preparation. The method adopts the composite seed crystal with affinity effect on the polyvinylidene fluoride to protect the high-energy crystal face of the polyvinylidene fluoride, and reduces the crystal face to prevent disordered aggregation and enable the crystal to be crystallized and developed along a one-dimensional direction. The invention utilizes the special affinity function of the composite seed crystal and the incomplete fluorinated molecular chain of the polyvinylidene fluoride to realize the control of the molecular conformation of the polyvinylidene fluoride during the forming, thereby controlling the folding and aggregation modes of the molecular chain during the crystallization. The method can control the amount of nucleation of polyvinylidene fluoride, obtain directionally aggregated high-energy crystal faces by using the steric hindrance of seed crystals and the protection of specific crystal faces, and combine the interfacial effect and the shearing action in the product forming process, thereby obtaining the directional assembly of the polyvinylidene fluoride crystal faces and forming the porous polyvinylidene fluoride polymer material product consisting of ordered nanofiber crystals.
Description
Technical Field
The invention relates to the technical field of preparation of ordered porous structure materials, in particular to an ordered porous structure material based on a common crystalline polymer and a preparation method of the material.
Background
The ordered porous material is a material which is provided with micropores, the micropores are orderly arranged on the surface and the internal space of the material, and the size of the micropores can be regulated and controlled within the size from nanometer to micrometer.
The porous film with ordered surface belongs to one kind of porous material and may be used in catalyst carrier, filtering film, dialysis film, template material, optical material, biomedicine material, super hydrophobic surface, etc. Therefore, once it appears, it has received high attention from the international physical, chemical and material communities and has rapidly developed into one of the research hotspots across disciplines. In recent years, the research of the ordered porous film is rapidly developed, so that the ordered porous film becomes a very active research field and provides possibility for further exploring the application of the ordered porous film.
The preparation of the ordered porous material can adopt a photoetching technology, and the technology is widely researched and used in the field of materials as a traditional micro-nano processing means. Photolithography techniques include electron beam lithography, X-ray lithography, scanning probe lithography, and the like. Since the invention, the photolithography technology has been the dominance of the semiconductor industry, and has been developed rapidly in recent decades, the resolution has been gradually improved, and the patterning technology can reach nanometer level. However, as a decomposition and transformation process from large to small, the photolithography technique has the disadvantages of complicated process, high equipment requirement, high cost and the like, and is difficult to realize large-scale production and application.
The template method is another method for effectively preparing the ordered porous structure. In brief, the template method is to fill and mold the template with the original shape and then remove the template so that the material forms an ordered porous structure with a certain shape and structure. However, the template method has many disadvantages, firstly, the source of the template is limited, secondly, the template is not completely removed, more defects are caused in the processes of solvent and ignition, and the problem of uneven thickness of the porous ordered material prepared by the template method still exists.
The principle of the method is that in a humid environment, the temperature of the surface of a high molecular solution is reduced due to the evaporation effect of a solvent, water vapor in the air is condensed into water drops on a gas-liquid contact surface, the water drops are continuously generated on the surface of the high molecular solution along with the evaporation of the solvent, the condensed water drops are dispersed in a polymer, the water drops are continuously interacted with each other and are finally arranged into a regular hexagonal lattice structure and sink under the gravity effect, after the solvent is volatilized, the water drops are gradually evaporated, and the polymer part occupied by the original water drops forms holes to form an ordered film structure. The template used in the odour pattern method is the most common water, is environment-friendly and easy to obtain, and experimental conditions are easy to control, but the film forming strength is weak, and large-scale production and application are still difficult.
The ordered porous structure can also be carried out in a self-assembly mode, wherein the self-assembly refers to a technology that basic structural units (molecules, nano materials, substances with the size of micron or larger) are spontaneously organized or aggregated into a stable and ordered structure under the action of non-covalent bonds such as hydrogen bonds, van der waals force, electrostatic force and the like. Compared with etching technology, self-assembly is a typical method for constructing an ordered structure from small to large or from bottom to top. Although the self-assembly method can conveniently obtain the ordered porous structure, the raw material molecules must have a special structural form to enable the molecules to generate corresponding special interaction, such as hydrogen bonds, van der waals force, electrostatic force and the like, and the assembly can be carried out only after the molecules generate the interaction, so the raw material selection is greatly limited.
Obviously, because of the size effect of the one-dimensional nano-fiber crystals, the porous products formed by the one-dimensional nano-crystalline materials have outstanding porosity, pore connectivity and mechanical properties, so that the preparation research and application research on the properties and functions of the one-dimensional nano-structures by synthesis and characterization and by applying theoretical and experimental means are increasingly attracting great interest in academia and industrial fields.
Crystallization is an effective self-assembly process that allows for the directed assembly of disordered molecules into a variety of ordered morphologies. For small molecules, one mesogenic theory is gradually accepted and utilized by researchers, as opposed to the traditional crystallization process (nucleation and growth mechanism). Mesomorphic theory states that: first, a plurality of monomers (molecules or ions) are aggregated to form a nanocrystal (in which the interior of the crystal grain may not completely reach the ordered state of the crystal), and then ordered assembly is performed to form a crystal. The monomers that are assembled are not individual molecules or ions, but rather preliminary aggregates thereof. The crystallization kinetics are due to the high surface energy of the nanocrystals, and one-dimensional directional aggregation often occurs if the grains have an asymmetric structure or different crystal plane energies.
In contrast to small molecule crystallization, for polymers with highly entangled molecular segments, the crystallization process is more complicated and is always one of the challenging basic problems in the field of polymer physics. Polymer crystallization tends to form metastable platelets with folded chains rather than directly generating the most stable extended chain crystals. Through slow crystallization of dilute solutions, lamellar single crystals of polymers can be obtained, thus recognizing that polymer platelets play a particularly important role in polymer crystal morphology. The special structural form of the polymer crystal is different from that of the small molecule crystal, so that the research on the polymer crystal not only needs to consider the crystallization thermodynamics, but also has important kinetic processes.
In addition, in polymer crystallization studies, even if nanocrystals can be used as an intermediate stage of crystallization, they are rarely observed directly because it is difficult to form nanocrystals themselves for highly entangled macromolecular chains, and even if they can be formed, they are extremely unstable as an intermediate stage in the early stage, are evanescent in most moments, and are rarely captured, let alone in the preparation and stable presence of the product.
Disclosure of Invention
Problem (A)
In summary, how to provide a polymer crystalline porous material with simple production process becomes a problem to be solved by those skilled in the art.
(II) technical scheme
In a first aspect of the embodiments of the present invention, a method for preparing an ordered porous structure material based on a common crystalline polymer is disclosed, the method comprising:
the composite seed crystal with affinity to polyvinylidene fluoride is adopted to protect the high-energy crystal face of polyvinylidene fluoride, disordered aggregation of polyvinylidene fluoride microcrystals can be prevented by reducing the crystal face of polyvinylidene fluoride, and polyvinylidene fluoride crystals are crystallized and developed along a one-dimensional direction.
Optionally, the method includes the steps of:
adding a composite seed crystal with affinity to polyvinylidene fluoride into a polyvinylidene fluoride solution to prepare a membrane casting solution;
carrying out gel operation on the membrane casting solution and preparing a gel membrane;
and washing the gel film to prepare the polyvinylidene fluoride gel film with the surface of an ordered porous structure.
Optionally, after the membrane casting solution is prepared, the membrane casting solution is subjected to stress shearing to obtain oriented and ordered PVDF aggregates, and then the gel operation is performed.
Optionally, performing stress shearing on the membrane casting solution through membrane scraping or fiber extrusion operation;
and/or, the gelling operation is carried out in a coagulation bath.
Optionally, the composite seed crystal comprises: soluble small molecule substances, rigid small molecule suspensions and polar organic molecule materials. Wherein the mass fraction of the soluble micromolecule substance is 30-60%, the mass fraction of the rigid micromolecule suspended substance is 10-35%, and the mass fraction of the polar organic molecule is 10-35%.
Optionally, the soluble small molecule substance includes a soluble inorganic salt and a soluble organic small molecule, the rigid small molecule suspension is an insoluble solid particle, and the polar organic molecule material is a polar organic molecule material chemically grafted on the surface of the solid particle.
Optionally, the polar organic molecular material comprises: one or more of polyethylene glycol, methoxy polyethylene glycol, polyurethane, ethylene glycol-polyurethane-ethylene glycol copolymer, styrene and ethylene glycol copolymer, poly N-methyl pyrrolidone, and copolymer of N-methyl pyrrolidone and N-methyl methacrylate; and/or, one or more of a soluble homopolymer or copolymer of a long chain fatty amine or a long chain fatty acid;
the rigid micromolecule suspended substance comprises one or more of sheet graphene, montmorillonite, transition metal sulfide, transition metal carbide and crosslinked and cured organic resin particles;
soluble small organic molecules include: one or more of C5-9 fatty acid ethylene glycol ester, C7-9 fatty acid diethylene glycol ester, diethylene glycol butyl ether, carbitol ester, propylene glycol carbonate, gamma-butyrolactone, diethyl phthalate, dibutyl phthalate, dioctyl phthalate and diisooctyl phthalate.
Optionally, the polar organic molecular material has a molecular weight of 200-1.0X 105In the meantime.
Optionally, the addition amount of the composite seed crystal in the polyvinylidene fluoride solution is 1 wt% -23 wt%.
In a second aspect of the embodiments of the present invention, there is also provided a regular porous structure material based on a common crystalline polymer, the regular porous structure material being prepared by the above preparation method of the regular porous structure material based on a common crystalline polymer.
(III) technical effects
The invention provides a preparation method of an ordered porous structure material based on a common crystalline polymer, and provides an ordered porous structure material based on a common crystalline polymer according to the method. According to the preparation method of the ordered porous structure material based on the common crystalline polymer, the composite seed crystal with affinity effect on polyvinylidene fluoride is adopted to protect the high-energy crystal face of polyvinylidene fluoride, and the polyvinylidene fluoride can be prevented from gathering by reducing the crystal face of polyvinylidene fluoride, so that the polyvinylidene fluoride crystal develops along one-dimensional direction crystallization.
The invention utilizes the special affinity function of the multifunctional composite seed crystal and the incomplete fluorinated molecular chain of the polyvinylidene fluoride to ensure the steric hindrance effect during processing and forming, and realizes the control of the molecular conformation of the polyvinylidene fluoride during forming, thereby controlling the folding and aggregation modes of the molecular chain (namely controlling the crystal structure and the microscopic form) during crystallization. The method not only can control the amount of nucleation of the polyvinylidene fluoride, but also can obtain directionally aggregated high-energy crystal faces by utilizing the steric hindrance of the seed crystal and the protection of the specific crystal faces, and combines the interface effect and the shearing action in the product forming process, so that the oriented assembly of the polyvinylidene fluoride crystal faces is obtained, and the porous polyvinylidene fluoride high polymer material product consisting of the ordered nano fiber crystals is formed.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
FIG. 1 is an enlarged view of an ordered porous structure material prepared by a method for preparing an ordered porous structure material based on a general crystalline polymer according to one embodiment of the present invention;
FIG. 2 is an enlarged view of an ordered porous structure material prepared by a method for preparing an ordered porous structure material based on a general crystalline polymer according to the second embodiment of the present invention;
FIG. 3 is an enlarged view of an ordered porous structure material prepared by a method for preparing an ordered porous structure material based on a general crystalline polymer according to the third embodiment of the present invention;
FIG. 4 is an enlarged view of an ordered porous structure material prepared by a method for preparing an ordered porous structure material based on a general crystalline polymer according to the fourth embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The present invention will be described in more detail with reference to the following embodiments in order to make the technical aspects of the present invention more apparent and understandable.
The invention utilizes the multifunctional composite seed crystal which controls the crystallization degree, the crystallization type (crystal form) and the microcosmic crystallization form of polyvinylidene fluoride (PVDF) and combines the interface effect in the film preparation process to complete the crystallization control in the phase conversion process of the PVDF.
Specifically, as an implementation mode, by utilizing the special affinity effect of the multifunctional composite seed crystal and the PVDF incomplete fluorinated molecular chain, a chemical structure capable of generating specific interaction is carried on the PVDF molecular chain, the steric hindrance effect during processing and molding is ensured, and the control on the conformation of the PVDF molecule during molding is realized, so that the folding and aggregation modes of the molecular chain during crystallization, namely the crystal structure and the micro form, are controlled. At the moment, the amount of nucleation of PVDF can be controlled, the directionally aggregated high-energy crystal face can be obtained by utilizing the steric hindrance of the seed crystal and the protection of the specific crystal face, and the interface effect and the shearing action in the product forming process are combined, so that the oriented assembly (oriented attachment) of the PVDF crystal face is obtained, and the porous PVDF high polymer material product consisting of the ordered nano fiber crystals is formed.
In the embodiment of the invention, the composite seed crystal capable of aggregating PVDF molecules is added in advance into the PVDF solution, which is embodied in that the composite seed crystal is compounded by a plurality of chemical materials, wherein the compounding is not only physical compounding, but also chemical reaction methods. The composition not only comprises soluble micromolecular substances and rigid micromolecular suspended substances, but also comprises polar organic molecular materials. The soluble micromolecule substance can be divided into soluble inorganic salt and soluble organic micromolecule; the rigid micromolecule suspended substance is insoluble solid particles; the polar organic molecular material is a polar macromolecular material chemically grafted on the surface of the solid particle.
In the embodiment of the present invention, preferably, in the composite seed crystal, the mass fraction of the soluble small molecule substance is 30 to 60 wt%, the mass fraction of the rigid small molecule suspension is 10 to 35 wt%, and the mass fraction of the polar organic molecule is 10 to 35 wt%.
In the embodiment of the present invention, it is preferable that the PVDF solution containing the composite seed crystal is subjected to film scraping at a speed of 1m/s or more, or fiber extrusion is performed using the above speed, so as to obtain a corresponding shear stress, so that the solution containing the PVDF aggregate obtains an orientation corresponding to the shear stress, and immediately placed in a coagulating bath (such as water), so that the PVDF aggregate is crystallized and solidified to form an ordered fiber crystal structure, and the aggregation of the fiber crystal is prevented by the thickness of the thin film, so as to obtain an ordered porous structure material.
In the embodiment of the invention, the polar organic molecular material in the composite seed crystal mainly comprises one or more of soluble homopolymers or copolymers of polyethylene glycol, methoxy polyethylene glycol, polyurethane, ethylene glycol-polyurethane-ethylene glycol copolymer, styrene-ethylene glycol copolymer (PS-b-PEG), poly N-methyl pyrrolidone (PVP), copolymer of N-methyl pyrrolidone and N-methyl methacrylate (PVP-b-PMMA-b-PVP), long-chain fatty amine or long-chain fatty acid, and the molecular weight is 200-1.0 x 105In the meantime.
The soluble small molecule substance comprises a certain amount of C5～9Fatty acid ethylene glycol ester, C7～9Fatty acid diethylene glycol ester, diethylene glycol butyl ether, carbitol ester, propylene glycol carbonate, gamma-butyrolactone, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diisooctyl phthalate and other small molecular organic matters.
The composite seed crystal can be mutually soluble with a common organic solvent within a certain range, and PVDF molecules can be well gathered in a PVDF solution to form a PVDF cluster polymer, so that the composite seed crystal has a good orientation effect under shear stress, is not easy to relax within a short time, and forms ordered fiber crystals in the curing process.
The main reason why the multifunctional composite seed crystal of the invention can be used for obtaining the nanofiber crystal is that one or more chemical reagents in the composite seed crystal have special affinity with PVDF, so that part of high-energy crystal faces can be protected, the crystal faces can be greatly reduced and cannot be further developed or aggregated, and the development of the crystal is along a one-dimensional direction.
In the embodiment of the invention, the addition amount of the composite seed crystal in the PVDF solution is 1-23 wt%.
Specifically, the special affinity effect of the multifunctional composite seed crystal and the incomplete fluorinated molecular chain of the polyvinylidene fluoride is utilized, the steric hindrance effect during processing and forming is ensured, the control of the conformation of the polyvinylidene fluoride molecules during forming is realized, and the folding and aggregation modes of the molecular chain (namely the control of the crystal structure and the microscopic form) during crystallization are controlled. The method not only can control the amount of nucleation of the polyvinylidene fluoride, but also can obtain directionally aggregated high-energy crystal faces by utilizing the steric hindrance of the seed crystal and the protection of the specific crystal faces, and combines the interface effect and the shearing action in the product forming process, so that the oriented assembly of the polyvinylidene fluoride crystal faces is obtained, and the porous polyvinylidene fluoride high polymer material product consisting of the ordered nano fiber crystals is formed.
The invention will be further illustrated by the following specific examples:
example 1
⑴ preparing casting solution, dissolving polyvinylidene fluoride powder in dimethylacetamide solvent, preparing 10% casting solution, adding 5% ester composite seed crystal, heating in a heating jacket at 50 deg.C, stirring for 1h to obtain uniform and clear casting solution, standing in an electrothermal blowing drying oven at 50 deg.C for 2h to defoam completely;
⑵ preparing gel film by coating the obtained membrane casting solution on non-woven fabric in an electrothermal blowing dry box at 50 deg.C, soaking in a constant temperature water bath at 0 deg.C under a sealing condition, and maintaining for 24 hr to allow the gel to crystallize to form gel film;
⑶ post-treatment, namely placing the obtained gel film in a methanol extracting agent for washing for three times, wherein the first washing time is 30min, the second washing time is 2h, and the third washing time is 24 h.
The polyvinylidene fluoride gel film prepared in example 1 is shown in fig. 1.
Example 2
⑴ preparing casting solution, dissolving polyvinylidene fluoride powder and alcohol compound seed crystal in mixed solvent of triethyl phosphate and the compound seed crystal, the mass fraction of polyvinylidene fluoride powder is 8%, the mass fraction of compound seed crystal is 4%, then placing the mixture in a heating jacket at 100 ℃ to heat and stir for 3h, thus obtaining even and clear casting solution, then placing the casting solution in an electrothermal blowing dry box at 100 ℃ to stand for 2h, and fully defoaming the casting solution for standby;
⑵ preparing gel film by knife coating the obtained casting solution on a stainless steel plate in an electrothermal blowing dry box at 100 deg.C, immediately soaking in constant temperature water bath at 20 deg.C for 20min to crystallize gel to form gel film;
⑶ post-treatment, namely placing the obtained gel film in a methanol extracting agent for washing for three times, wherein the first washing time is 30min, the second mass fraction is 2h, and the third mass fraction is 24 h.
The polyvinylidene fluoride gel film prepared in example 2 is shown in fig. 2.
Example 3
⑴ preparing casting solution, dissolving polyvinylidene fluoride powder and phthalate diester composite seed crystal in dimethylacetamide, wherein the mass fraction of polyvinylidene fluoride powder is 12% and the composite seed crystal is 3%, placing the mixture in a heating jacket at 80 ℃ to heat and stir for 3h to obtain uniform and clear casting solution, placing the casting solution in an electrothermal blowing dry box at 80 ℃ to stand for 2h to fully defoam the casting solution for later use;
⑵ preparing gel film by knife coating the obtained casting solution on a stainless steel plate in an electrothermal blowing dry box at 80 deg.C, immediately immersing in 80 deg.C constant temperature water bath, and maintaining for 24 hr to crystallize gel to form gel film;
⑶ post-treatment, namely placing the obtained gel film in a methanol extracting agent for washing for three times, wherein the first washing time is 30min, the second washing time is 2h, and the third washing time is 24 h.
The polyvinylidene fluoride gel film prepared in example 3 is shown in fig. 3.
Example 4
⑴ preparing casting solution, dissolving polyvinylidene fluoride powder and ester composite seed crystal in dimethyl formamide solvent, the mass fraction of polyvinylidene fluoride powder is 15%, the composite seed crystal is 2%, then placing in a heating jacket at 50 deg.C, heating and stirring for 1h to obtain uniform and clear casting solution, then placing the casting solution in an electrothermal blowing dry box at 50 deg.C, standing for 2h to defoam it fully for use;
⑵ preparing gel film by scraping the obtained membrane casting solution in an electrothermal blowing dry box at 50 deg.C, maintaining at 10 deg.C and 60% humidity for 4h to induce phase separation with steam to form gel film;
⑶ post-treatment, namely placing the obtained gel film in a methanol extracting agent for washing for three times, wherein the first washing time is 30min, the second washing time is 2h, and the third washing time is 24 h.
The polyvinylidene fluoride gel film prepared in example 4 is shown in fig. 4.
The invention relates to a method for preparing an ordered porous structure material, which utilizes a common crystallization polymer solution crystallization process and multifunctional composite seed crystals for effectively controlling the crystallization degree, the crystallization type (crystal form) and the microscopic crystallization form of polyvinylidene fluoride (polyvinylidene fluoride), adopts a common solution phase separation method, combines the ultrathin membrane interface effect and the space effect, has an ordered fiber crystal structure, can effectively prevent the deformation and aggregation of fiber crystals, and finally forms the ordered porous structure.
The special affinity action of the multifunctional composite seed crystal and the incomplete fluorinated molecular chain of the polyvinylidene fluoride is adopted, the steric hindrance effect during the processing and forming in a solution or molten state is ensured, the control of the conformation of the polyvinylidene fluoride molecules during the forming is realized, the folding and aggregation modes of the molecular chain during the crystallization, namely the crystal structure and the microscopic morphology are controlled, the nucleation quantity of the polyvinylidene fluoride can be controlled, the steric hindrance of the seed crystal and the protection of a specific crystal face can be utilized, the directionally aggregated high-energy crystal face can be obtained, the forming process of the product is combined, the oriented assembly of the polyvinylidene fluoride crystal face is obtained, the orderly-arranged nano fiber crystal material is formed, and meanwhile, the fiber crystal is prevented from being changed in the later period by utilizing the film interface effect and the solution phase separation principle, and the orderly porous structure is obtained.
Specifically, the one-dimensional polymer nanofibers are generally formed by drawing a polymer solution through an external force, which may be an electrostatic force, a high-speed wind force, or the like, such as electrospinning and air-flow spinning.
In the invention, firstly, through the early-stage deep research on the crystallization process of the high molecular solution, including the solution phase separation mechanism, the high molecular clustering, the mesomorphism formation and the like, the polymer sectional crystallization is realized by utilizing the crystal nucleus induction with different properties, the interaction of a solvent and a non-solvent and combining the protection of the high-energy crystal face of the nano-crystal in the porous membrane forming process. Then, by utilizing the ultrathin film interface effect and the space effect, the growth of spherulites is limited while the nucleation and the directional growth of the interface are realized, and the ordered nano fibrous crystal structure is formed by assembling. Or, adopting a plurality of inducing factors and solvent exchange processes, and carrying out one-dimensional directional assembly through external force guidance and the geometrical structure characteristics of the crystal face of the nano-crystal to prepare the nano-fiber crystal array and other ordered structures.
The ordered porous structure membrane material can be used for high-efficiency filtration and separation membranes, catalyst carriers, structural color materials, biomedical materials, super-hydrophobic surfaces and the like.
The other main characteristic of the invention is that the polyvinylidene fluoride solution containing the composite seed crystal is sheared with certain stress, such as film scraping or fiber extrusion, to obtain a solution of polyvinylidene fluoride aggregate with certain orientation, and the solution is immediately put into a coagulating bath (such as water) to ensure that the polyvinylidene fluoride aggregate is crystallized and solidified to form an ordered fiber crystal structure, and the aggregation of the fiber crystal is prevented through the thickness of the film, so as to obtain the ordered porous structure material.
The seed crystal adopted by the invention can be mutually soluble with a common organic solvent, and can well gather polyvinylidene fluoride molecules in a polyvinylidene fluoride solution to form a polyvinylidene fluoride cluster polymer, so that the seed crystal has a good orientation effect under shear stress and is not easy to relax in a short time, and thus, ordered fiber crystals are formed in the curing process.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.
Claims (10)
1. A method for preparing an ordered porous structure material based on a common crystalline polymer is characterized by comprising the following steps:
the composite seed crystal with affinity to polyvinylidene fluoride is adopted to protect the high-energy crystal face of polyvinylidene fluoride, disordered aggregation of polyvinylidene fluoride microcrystals can be prevented by reducing the crystal face of polyvinylidene fluoride, and polyvinylidene fluoride crystals are crystallized and developed along a one-dimensional direction.
2. A method for preparing a material with ordered porous structure based on common crystalline polymer according to claim 1, characterized in that it comprises the steps of:
adding a composite seed crystal with affinity to polyvinylidene fluoride into a polyvinylidene fluoride solution to prepare a membrane casting solution;
carrying out gel operation on the membrane casting solution and preparing a gel membrane;
and washing the gel film to prepare the polyvinylidene fluoride gel film with the surface of an ordered porous structure.
3. The method for preparing ordered porous structure material based on common crystalline polymer according to claim 2,
and after the membrane casting solution is prepared, carrying out stress shearing on the membrane casting solution to obtain a PVDF aggregate with ordered orientation, and then carrying out gel operation.
4. The method for preparing ordered porous structure material based on common crystalline polymer according to claim 3,
carrying out stress shearing on the membrane casting solution through membrane scraping or fiber extrusion operation;
and/or, the gelling operation is carried out in a coagulation bath.
5. The method for preparing ordered porous structure material based on common crystalline polymer according to claim 1,
the composite seed crystal comprises: soluble small molecule substances, rigid small molecule suspended matters and polar organic molecules;
wherein the mass fraction of the soluble micromolecular substance is 30-60%, the mass fraction of the rigid micromolecular suspension is 10-35%, and the mass fraction of the polar organic molecule is 10-35%.
6. The method for preparing ordered porous structure material based on common crystalline polymer according to claim 5,
the soluble small molecule substance comprises soluble inorganic salt and soluble organic small molecule, the rigid small molecule suspended substance is insoluble solid particles, and the polar organic molecule is a polar organic molecule material chemically grafted on the surfaces of the solid particles.
7. The method for preparing ordered porous structure material based on common crystalline polymer according to claim 1,
the polar organic molecules include: one or more of polyethylene glycol, methoxy polyethylene glycol, polyurethane, ethylene glycol-polyurethane-ethylene glycol copolymer, styrene and ethylene glycol copolymer, poly N-methyl pyrrolidone, and copolymer of N-methyl pyrrolidone and N-methyl methacrylate; and/or, one or more of a soluble homopolymer or copolymer of a long chain fatty amine or a long chain fatty acid;
the rigid micromolecule suspended substance comprises one or more of sheet graphene, montmorillonite, transition metal sulfide, transition metal carbide and crosslinked and cured organic resin particles;
the soluble small organic molecules include: one or more of C5-9 fatty acid ethylene glycol ester, C7-9 fatty acid diethylene glycol ester, diethylene glycol butyl ether, carbitol ester, propylene glycol carbonate, gamma-butyrolactone, diethyl phthalate, dibutyl phthalate, dioctyl phthalate and diisooctyl phthalate.
8. Method for preparing ordered porous materials based on common crystalline polymers according to any of claims 1 to 7, characterized in that the molecular weight of said polar organic molecules is comprised between 200 and 1.0 x 105In the meantime.
9. The method for preparing an ordered porous structure material based on common crystalline polymer according to any of claims 1 to 7, wherein the addition amount of the composite seed crystal in the polyvinylidene fluoride solution is 1 wt% -23 wt%.
10. An ordered porous structure material based on a common crystalline polymer, characterized in that it is prepared by the method for preparing an ordered porous structure material based on a common crystalline polymer according to any one of claims 1 to 9.
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| CN112768600A (en) * | 2020-12-30 | 2021-05-07 | 成都中电熊猫显示科技有限公司 | Metal oxide semiconductor sensor and preparation method thereof |
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| CN1687222A (en) * | 2005-03-29 | 2005-10-26 | 哈尔滨工业大学 | Modification film of polyvinylidene fluoride and preparation method thereof |
| CN101362057A (en) * | 2008-01-30 | 2009-02-11 | 清华大学 | Method for preparing polyvinylidene fluoride porous membrane |
| CN102179187A (en) * | 2010-12-10 | 2011-09-14 | 顾方明 | Polyvinylidene fluoride ultrafiltration membrane and preparation method thereof |
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| CN112768600B (en) * | 2020-12-30 | 2024-05-03 | 成都京东方显示科技有限公司 | Metal oxide semiconductor sensor and preparation method thereof |
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