Method and equipment for preparing nanofiber with three-chamber eccentric parallel structure

Abstract

The invention discloses a preparation method and equipment of three-chamber eccentric parallel structure nanofibers. The preparation method comprises the following steps: simultaneously carrying out high-voltage electrostatic spinning on three spinning solutions; the two spinning solutions are respectively divided into microfluids to be led out through an array formed by two sets of series metal capillary tubes; the other spinning solution is divided into microfluids to be led out through a plurality of bottom through holes of the insulating container; the first series of metal capillary tubes are inserted into the second series of metal capillary tubes to form a series of metal capillary eccentric sleeves; the series of metal capillary eccentric sleeves penetrate through the insulating container and extend out of one side of the interior of the bottom through hole to form a combined eccentric outlet of three strands of spinning solutions; three spinning solutions are guided into a high-voltage electrostatic field in an eccentric parallel mode through the combined eccentric outlet, and the three-chamber eccentric parallel structure nanofiber is formed through single-step direct stretching. According to the method, the capability of preparing the three-chamber eccentric parallel structure characteristic nanofiber with a complete structure in a single-step, batch and large-scale manner is endowed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nanomaterial preparation, and relates to a preparation method and equipment of a three-chamber eccentric parallel structure nanofiber. BACKGROUND

[0002] The material world is structure-controlled (Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology 2019, DOI:10.1002 / wnan.1601), and nanostructure means new nanotechnology, and the preparation method of nanomaterials should be classified according to their final structure (see“In nanoscience, the ability to make new structures enables new science and technology. The ways nanomaterials are made can be classified according to what determines the final structure of the material”in Isaacoff BP, KA Brown. Progress in top-down control of bottom-up assembly. Nano Letters 2017, 17, 6508-6510). The importance of artificial nanostructures and their preparation methods in the field of nanotechnology is self-evident.

[0003] In nature, whether macro or micro, whether cell or molecule, complex multi-chamber structures with both parallel and core-shell structures exist universally, and they are associated with each other, which together give the object unique properties and functions. "Taoism follows nature", taking the complex multi-chamber structure of parallel and core-shell structures as the supporting platform, which can provide effective inspiration and ideas for the design and development of various advanced functional nanomaterials. However, compared with nature, human beings are still very immature in the preparation and application of complex artificial nanostructures. The two most common structural features are core-shell structure (or core-sheath structure) and side-by-side structure (or Janus structure) (see Walther A, Müller AH. Janus particles: Synthesis, self-assembly, physical properties, and applications. Chemical Reviews 2013, 113(7), 5194-5261). These are also the two most basic structures in nature, the former reflects the relationship between the inside and outside space, and the latter reflects the relationship between the left and right or the upper and lower space. These two most basic two-chamber structural features have provided extensive support for the construction of structure-property-function utility relationship of nanomaterials in the past three decades since the rise of nanotechnology (see Li M, Wang H, Zhu W, Li W, Wang C, Lu X. RuNanoparticles embedded in N-doped carbon nanofibers as a robust bifunctional catalyst for efficient overall water splitting. Advanced Science 2020, 7, 1901833).

[0004] On the Web of Science, there are hundreds of thousands of papers on the topic of "core-shell or core-sheath" and "Janus or side-by-side". Based on the comprehensive research reports on these two two-compartment structures, various multi-compartment complex nanostructures are attracting worldwide attention. These structures include three or more core-shell structures, three or more side-by-side structures, and one-sheath multi-core island structures. Among various multi-compartment nanostructures (corresponding to English words including: multiple-compartment nanostructure, hierarchical structure, multi-chamber nanostructure, composite / complicated / complex nanostructure, etc.), the multi-compartment structure composed of side-by-side structure and core-shell structure has the advantages and characteristics of both core-shell structure and side-by-side structure, and therefore has more advantages in the design of nano-material functions than single multi-level core-shell structure or single multi-level side-by-side structure. Since the interface between material and environment plays a crucial role in the function of nano-materials, compared with the multi-level composite multi-compartment structure containing side-by-side structure in the core-shell structure, the composite multi-compartment structure containing core-shell structure in the side-by-side structure will be more flexible and effective in the regulation of nano-material function (see Lauhon LJ, Gudiksen MS, Wang D, Lieber CM. Epitaxial core-shell and core-multishell nanowire heterostructures. Nature 2002, 420, 57-61).

[0005] The preparation of complex nanostructures is similar to that of ordinary nanomaterials, mainly through two approaches: top-down and bottom-up. Various different preparation techniques have emerged for each of these two approaches. Among numerous top-down technologies, electrohydrodynamic atomization (EHDA), based on the interaction between fluids and high-voltage electrostatics (including high-voltage electrospinning, high-voltage electrospinning mist, and spinning inkjet printing technologies, etc. (Liu H, Zhang S, Liu L, Yu J, Ding B. High-performance PM0.3 airfilters using self-polarized electret nanofiber / nets. Advanced Functional Materials 2020, 1909554), can effectively overcome the shortcomings of bottom-up technologies, such as cumbersome processes, time consumption, and difficulty or even impossibility in scaling up production, and has gained increasing popularity in recent years. Among various EHDA technologies, high-voltage electrospinning (referred to as electrospinning) has developed rapidly due to its powerful nanofiber preparation capabilities, simple and effective preparation process, and flexible and varied nanofiber functional control strategies. On the other hand, the batch single-step preparation of complex nanostructures is a problem that nanotechnology cannot directly solve. Solving this problem will open up new avenues for the commercial application of many advanced functional materials based on complex nanostructures, and multi-fluid electrospinning technology can provide a potential answer to this problem.

[0006] Based on the two important issues mentioned above, namely "controllable preparation of complex nanostructures" and "large-scale production of functional nanomaterials", this invention, based on repeated experiments and following the behavior characteristics of fluids under high voltage electric fields and basic natural laws, proposes for the first time a method and equipment for the batch preparation of three-chamber eccentric parallel nanostructures. Summary of the Invention

[0007] Due to the aforementioned deficiencies in the existing technology, the present invention provides a method and apparatus for preparing three-chamber eccentric parallel structure nanofibers to solve the problem that it is difficult to prepare structurally complete three-chamber eccentric parallel structure nanofibers and to achieve industrial-scale production.

[0008] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing three-chamber eccentric parallel structure nanofibers, characterized in that: three spinning solutions are simultaneously subjected to high-voltage electrospinning;

[0009] The first and second spinning solutions are respectively divided into microfluidic leads through an array of two sets of series of metal capillary tubes from respective collection inlets; the third spinning solution is divided into microfluidic leads from a plurality of bottom through-holes of the insulating container; an outer diameter of the first series of metal capillary tubes is smaller than an outer diameter of the second series of metal capillary tubes, the first series of metal capillary tubes are inserted into the second series of metal capillary tubes to form a series of metal capillary eccentric sleeve; the series of metal capillary eccentric sleeve penetrates through the insulating container and extends 0.8-1.2 mm from an inner side of the bottom through-holes of the insulating container to form a combined eccentric outlet of the three spinning solutions; the three spinning solutions are guided into a high-voltage electrostatic field in an eccentric parallel manner through the combined eccentric outlet to form three-chamber eccentric parallel structure nanofibers through single-step direct stretching.

[0010] The above technical solution uses the insulating container and the two sets of metal capillary tube arrays penetrating through the insulating container as microfluidic control transportation units of the three spinning solutions, the bottom through-holes of the insulating container and the pipe openings of the metal capillary eccentric sleeve jointly form a common outlet for the parallel eccentric leading-out of the three fluids, the three different fluids are synchronously guided into the high-voltage electrostatic field, the common outlet of the series of combined eccentric structures is used as a macroscopic template, under the high-voltage electrostatic field, through the interaction between the high-voltage electrostatic field and the fluids, the three spinning fluids are stretched into three-chamber eccentric parallel structure nanofibers within a few milliseconds; the numerous nozzle outlets are needle-shaped metal tips plus the eccentric small hole structure of the insulating container, which is beneficial to the guiding effect of the "needle", the "wall attachment" of the liquid flowing out of the small hole and the parallel eccentric effect, and ensures the accurate "copying" from the macroscopic combined outlet template to the microscopic three-chamber eccentric parallel structure characteristic nanofibers under the high-voltage electrostatic field; the capillary tube, the fluid in the capillary tube and the fluid outside the capillary tube jointly form an integral whole, under the surface tension of the three fluids, a round Taylor cone is formed, so that the combined outlet forms a complete charged whole, which does not form a repulsion effect like the traditional one-row needle-shaped electrospinning, overcomes the limitations of the traditional needle-shaped electrospinning technology in the laboratory-scale preparation of multi-chamber nanofibers, and endows the single-step with the ability to effectively and batch-scale prepare three-chamber eccentric parallel structure characteristic nanofibers with complete structure, and the insulating container can effectively prevent a large amount of static electricity from dispersing to the surrounding atmosphere, resulting in a huge loss of electric energy.

[0011] Further, the part where the first series of metal capillary tubes is inserted into the second series of metal capillary tubes is sealed by sealing glue. The sealing glue can be any sealing glue that does not react with the spinning solution, such as epoxy resin glue.

[0012] Further, the thickness of each chamber in the three-chamber eccentric parallel structure nanofiber is controlled by adjusting the polymer concentration in the corresponding spinning solution and / or the absolute flow rate of the corresponding spinning solution and the relative flow rate of each spinning solution. In this way, the present application can conveniently realize the free control of the structure parameters of the nanofiber itself, which is very important for the functionalization of the nanofiber.

[0013] Further, the center distance of the bottom through holes in the insulating container is 2-5 cm. In this way, the electrostatic interference between the common outlets can be avoided.

[0014] Further, the high-voltage electrospinning step comprises:

[0015] The first syringe is installed on the first syringe pump, and the outlet of the first syringe is connected to the inlet of the insulating container through a liquid outlet pipe; the second syringe is installed on the second syringe pump, and the outlet of the second syringe is connected to the inlet end of the first series of metal capillary tubes through a liquid outlet pipe; the third syringe is installed on the third syringe pump, and the outlet of the third syringe is connected to the inlet end of the second series of metal capillary tubes through a liquid outlet pipe;

[0016] The fiber receiving plate is arranged directly below the insulating container, and the high-voltage generator is electrically connected to the first series of metal capillary tubes and the second series of metal capillary tubes; the surface of the fiber receiving plate is made of an electrically conductive material; the fiber receiving plate and the high-voltage generator are both grounded;

[0017] The first syringe, the second syringe, and the third syringe are respectively added with spinning solutions, and the first syringe pump, the second syringe pump, the third syringe pump, and the high-voltage generator are started, so as to prepare three-chamber eccentric parallel structure nanofibers in a single step and in batch through the action of a high-voltage electrostatic field.

[0018] Further, the first spinning solution is an ethanol solution of 10-30wt% ethyl cellulose; the second spinning solution is an ethanol solution of 5-12wt% polyvinylpyrrolidone; the third spinning solution is a 75vol% ethanol aqueous solution of 15-30wt% zein; the flow rate of the first syringe is 5-20 mL / h, the flow rate of the second syringe is 5-20 mL / h, and the flow rate of the third syringe is 5-20 mL / h; the receiving distance of the fiber receiving plate is 10-20 cm, and the output voltage of the high-voltage generator is 25-40 kV.

[0019] In this way, the preparation of three-chamber eccentric parallel structure nanofibers can be realized as long as at least one of the three spinning solutions has spinnability, which greatly expands the selection range of materials constituting the nanofibers. The parameters that mainly affect the spinning quality include the applied voltage, the total flow rate of all the spinning solutions, the compatibility between the fluids, and the relative flow rate between the fluids.

[0020] In another aspect, the present application provides a device for preparing a three-chamber eccentric parallel structure nanofiber, comprising a high-voltage electrospinning device for implementing the preparation method as described above; the flow guide spinning head of the high-voltage electrospinning device comprises a first series of metal capillary tubes, a second series of metal capillary tubes, and an insulating container; a first spinning solution is microfluidically introduced through an array of the first series of metal capillary tubes; a second spinning solution is microfluidically introduced through an array of the second series of metal capillary tubes; and a third spinning solution is microfluidically introduced through a plurality of bottom through-holes of the insulating container; the first series of metal capillary tubes are inserted into the second series of metal capillary tubes to form a series of metal capillary eccentric sleeve pipes; the series of metal capillary eccentric sleeve pipes penetrate through the insulating container and extend 0.8-1.2 mm from the bottom through-holes of the insulating container to form a combined eccentric outlet of the three spinning solutions.

[0021] Further, the insulating container serves as the basket body of the basket, and the series of metal capillary eccentric sleeve pipes are uniformly inserted into the basket body.

[0022] Further, the insulating container is sealed by the insulating layer at the penetration positions of the first series of metal capillary tubes and the second series of metal capillary tubes, further reducing the loss of electric energy.

[0023] The above technical solution is only one possible technical solution of the present application, and the protection scope of the present application is not limited to this. Those skilled in the art can reasonably adjust the specific design according to actual needs.

[0024] The above-mentioned application has the following advantages or beneficial effects:

[0025] (1) The capillary tube, the fluid in the capillary tube, and the fluid outside the capillary tube collectively form an integral whole, under the surface tension of the three fluids, forming a round Taylor cone, so that the eccentric combined outlet forms a complete charged whole, and does not form a repulsive effect like the traditional one-row needle type electrospinning, overcoming the limitations of the traditional needle type electrospinning technology in the laboratory scale preparation of multi-chamber nanofibers, and endowing the ability to effectively and batch-scale prepare three-chamber eccentric parallel structure characteristic nanofibers with complete structure in a single step; meanwhile, the insulating container can effectively prevent the dispersion of a large amount of static electricity to the surrounding atmosphere, resulting in a huge loss of electric energy;

[0026] (2) The nozzle outlet of the present application is a needle type metal tip plus an eccentric small hole structure of the insulating container, which is conducive to the guiding effect of the "needle", and the "wall attachment" and eccentric parallel effect of the liquid flowing out of the small hole, ensuring the accurate "copying" from the macro combined outlet template to the micro three-chamber eccentric parallel structure characteristic nanofiber under a high-voltage electrostatic field;

[0027] (3) The three-chamber eccentric parallel structure nanofiber of the application has the material property of heterojunction nanostructure, and can obtain controllable material performance by setting different hetero-materials. BRIEF DESCRIPTION OF DRAWINGS

[0028] The present application, its features, shapes and advantages will become more apparent by reading the detailed description of the non-limiting embodiments, made with reference to the following drawings. In all the drawings, the same references indicate the same parts. The drawings are not necessarily drawn to scale, the emphasis being on illustrating the principle of the application.

[0029] Figure 1 It is a schematic diagram of a multi-fluid high-voltage electrospinning device in an embodiment of the application;

[0030] Figure 2 It is a structural schematic diagram of a micro-fluid spinning head for high-voltage electrospinning and one of its common outlets in an embodiment of the application;

[0031] Figure 3 It is a photo of a micro-fluid spinning head for high-voltage electrospinning in an embodiment of the application;

[0032] Figure 4 It is a scanning electron microscope observation diagram of the three-chamber eccentric parallel structure nanofiber prepared in Example 1 of the application;

[0033] Figure 5 It is a transmission electron microscope observation diagram of the three-chamber eccentric parallel structure nanofiber prepared in Example 1 of the application;

[0034] Figure 6 It is a scanning electron microscope observation diagram of the three-chamber eccentric parallel structure nanofiber prepared in Example 2 of the application;

[0035] Figure 7 It is a transmission electron microscope observation diagram of the three-chamber eccentric parallel structure nanofiber prepared in Example 2 of the application;

[0036] Figure 8 It is a scanning electron microscope observation diagram of the three-chamber eccentric parallel structure nanofiber prepared in Example 3 of the application;

[0037] Figure 9 It is a transmission electron microscope observation diagram of the three-chamber eccentric parallel structure nanofiber prepared in Example 3 of the application;

[0038] Wherein, 1, first capillary collection inlet; 2, second capillary collection inlet; 3, liquid inlet; 4, common outlet; 41, bottom through hole; 51, first series of metal capillary; 52, second series of metal capillary; 6, insulating container; 7, high voltage generator; 8, first syringe; 9, second syringe; 10, third syringe; 11, microfluidic spinning head; 12, first syringe pump; 13, second syringe pump; 14, third syringe pump; 15, first high elasticity silica gel tube; 16, second high elasticity silica gel tube; 17, third high elasticity silica gel tube; 18, fiber receiving plate; 19, fixed support. DETAILED DESCRIPTION

[0039] The application will be further described below in conjunction with the drawings and specific examples. It should be understood that these examples are only used to illustrate the application and not used to limit the scope of the application. Furthermore, it should be understood that after reading the content of the application, those skilled in the art can make various modifications or changes to the application, and these equivalent forms also fall within the scope defined by the appended claims of the application.

[0040] In the description of the present application, it should be understood that the terms "first", "second" are only used for description purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "several" is two or more, unless otherwise specifically limited. The monomer compounds and organic and inorganic solvents involved in the following examples are commercially available.

[0041] Example 1

[0042] Referring to Figures 1 to 3 , the present embodiment provides a method for preparing a three-chamber eccentric parallel structure nanofiber, which simultaneously performs high-voltage electrospinning on three kinds of spinning solutions. The prepared equipment is a conventional high-voltage electrospinning equipment configured with a specific microfluidic spinning head 11. Referring to Figure 2 and Figure 3 , in the microfluidic spinning head 11, the first spinning solution is microfluidically drawn through an array of first series of metal capillary 51; the second spinning solution is microfluidically drawn through an array of second series of metal capillary 52; the third spinning solution is microfluidically drawn through several bottom through holes 41 of the insulating container 6; the outer diameter of the first series of metal capillary is smaller than that of the second series of metal capillary, and the first series of metal capillary 51 is inserted into the second series of metal capillary 52 to form a series of metal capillary eccentric sleeve. Referring to Figure 3The first series of metal capillary tubes 51 are inserted into the second series of metal capillary tubes 52, and the insertion position is sealed by sealant. The series of metal capillary eccentric sleeve tubes pass through the insulation container 6 and extend 0.8-1.2 mm from the inside of the bottom through hole 41 of the insulation container 6, forming a combined eccentric outlet 4 of three spinning liquid streams. Preferably, the center-to-center distance of several bottom through holes 41 at the bottom of the insulation container 6 is 2-5 cm. The first series of metal capillary tubes 51 and the second series of metal capillary tubes 52 are respectively collected into a first capillary collection inlet 1 and a second capillary collection inlet 2. The material of the insulation container 6 is preferably polypropylene. The entire microfluidic spinning head 11 can be suspended and fixed on the operating table by a fixed support 19.

[0043] The three spinning liquids are introduced into the high-voltage electrostatic field in an eccentric parallel manner through the common outlet 4, and single-step direct stretching forms a three-chamber eccentric parallel structure nanofiber. Figure 2 Both the first series of metal capillary tubes 51 and the second series of metal capillary tubes 52 have 5 tubes. It can be understood that the number of metal capillary tubes can be adjusted according to the size of the insulation container. The junction between the metal capillary tube and the insulation container 6 can be sealed and fixed by epoxy resin or polyethylene film.

[0044] Specifically, the step of high-voltage electrospinning includes:

[0045] The first syringe 8 is installed on the first syringe pump 12, and the outlet of the first syringe 8 is connected to the inlet of the insulation container 6 through the first high-elasticity silicone tube 15. The second syringe 9 is installed on the second syringe pump 13, and the outlet of the second syringe 9 is connected to the inlet end of the first series of metal capillary tubes 51 through the second high-elasticity silicone tube 16. The third syringe 10 is installed on the third syringe pump 14, and the outlet of the third syringe 10 is connected to the inlet end of the second series of metal capillary tubes 52 through the third high-elasticity silicone tube 17. The spinning liquid is injected into the insulation container 6 through the liquid inlet 3 and led out from the bottom through hole 41 of the insulation container 6. The liquid inlet 3 can also serve as a cleaning port of the insulation container 6.

[0046] The fiber receiving plate 18 is arranged directly below the insulation container 6, and the surface of the fiber receiving plate 18 is made of conductive material, preferably aluminum foil wrapped hardboard; the high-voltage generator 7 is electrically connected to the first series of metal capillary tubes 51 and the second series of metal capillary tubes 52; the fiber receiving plate 18 and the high-voltage generator 7 are both grounded;

[0047] The first syringe 8, the second syringe 9, and the third syringe 10 are respectively added with the first spinning liquid, the second spinning liquid, and the third spinning liquid. The first syringe pump 12, the second syringe pump 13, the third syringe pump 14, and the high-voltage generator 7 are started, and three-chamber eccentric parallel structure nanofibers are prepared in a single step by the action of the high-voltage electrostatic field.

[0048] A specific application example of the above spinning device for batch preparation of three-chamber eccentric parallel structure nanofibers includes the following steps:

[0049] (1) Preparation of spinning solution;

[0050] The first spinning solution is an ethanol solution with a mass percentage concentration of 25% ethyl cellulose. The preparation method is as follows: 250 g of ethyl cellulose powder is placed in 750 g of ethanol, and stirred to dissolve, obtaining the spinning solution.

[0051] The second spinning solution is a mass percentage concentration of 8% polyvinylpyrrolidone solution. The preparation method is as follows: 80 g of polyvinylpyrrolidone is dissolved in 920 g of ethanol, obtaining the spinning solution.

[0052] The third spinning solution is a 75% (volume ratio) ethanol aqueous solution with a mass percentage concentration of 20% zein. The preparation method is as follows: 200 g of zein is dissolved in 800 g of ethanol solution, and stirred to dissolve, obtaining the spinning solution.

[0053] (2) The first, second, and third spinning solutions obtained in step (1) are respectively added to the corresponding syringes, and then the first injection pump 12, the second injection pump 13, and the third injection pump 14 are turned on;

[0054] (3) The flow rate of the first syringe 8 is controlled at 10 mL / h, the flow rate of the second syringe 9 is controlled at 10 mL / h, the flow rate of the third syringe 10 is controlled at 10 mL / h, the high-voltage generator 7 is turned on, the receiving distance of the fiber plate is adjusted to 15 cm, the voltage is raised to 34 kV for electrospinning, and three-chamber eccentric parallel structure nanofibers are prepared from the combination of the first and second spinning solutions with spinning properties and the third spinning solution without spinning properties, which is a single-step direct batch preparation.

[0055] The prepared nanofibers are observed after surface gold spraying by field scanning electron microscopy, and the results are shown in Figure 4 The prepared three-chamber eccentric parallel structure nanofibers are collected uniformly and exhibit good linear state, with a diameter of 750 ± 160 nm. The coaxial structure nanofibers are observed by high-resolution transmission electron microscopy, and the results are shown in Figure 5 The nanofibers are composed of multiple gray parts, reflecting the internal structure characteristics of three-chamber eccentric parallel. The materials corresponding to different gray areas from left to right are zein, ethyl cellulose, and polyvinylpyrrolidone, respectively. The thickness of zein on the left side is about 310 nm, the thickness of polyvinylpyrrolidone in the middle is about 330 nm, and the thickness of ethyl cellulose on the right side is about 160 nm.

[0056] Example 2

[0057] The embodiment provides a batch preparation method of three-chamber eccentric parallel structure nanofibers, and the preparation equipment and steps are similar to those of the embodiment 1, and the difference from the embodiment 1 is that:

[0058] The first spinning solution is an ethanol solution with a mass percentage concentration of 10% ethyl cellulose, and the preparation method is as follows: 100 g of ethyl cellulose powder is put into 900 g of ethanol, and stirring and dissolution are performed to obtain the spinning solution.

[0059] The second spinning solution is a polyvinylpyrrolidone solution with a mass percentage concentration of 12%, and the preparation method is as follows: 120 g of polyvinylpyrrolidone is dissolved in 880 g of ethanol to obtain the second spinning solution.

[0060] The third spinning solution is a 75% (by volume) ethanol aqueous solution with a mass percentage concentration of 15% corn alcohol-soluble protein, and the preparation method is as follows: 150 g of corn alcohol-soluble protein is dissolved in 850 g of ethanol solution, and stirring and dissolution are performed to obtain the third spinning solution.

[0061] The flow of the first injector 8 is controlled to be 5 mL / h, the flow of the second injector 9 is controlled to be 5 mL / h, the flow of the third injector 10 is controlled to be 5 mL / h, the high-voltage generator 7 is started, the fiber plate receiving distance is adjusted to be 10 cm, the voltage is increased to 25 kV, and electrospinning is performed, so that three-chamber eccentric parallel structure nanofibers are prepared from the combination of the first and second spinning solutions with spinning properties and the third spinning solution without spinning properties. Figure 6 and Figure 7 The prepared three-chamber eccentric parallel structure nanofibers are collected uniformly and present a good linear state, the diameter of the nanofibers is 510 ± 120 nm, and the three-chamber eccentric parallel structure characteristics are reflected, wherein the regions with different gray scales from top to bottom correspond to corn alcohol-soluble protein, polyvinylpyrrolidone and ethyl cellulose in sequence, wherein the thickness of the corn alcohol-soluble protein on the top is about 140 nm, the thickness of the polyvinylpyrrolidone in the middle is about 260 nm, and the thickness of the ethyl cellulose on the bottom is about 160 nm. Compared with the application embodiment 1, the second spinning solution is spinnable, and the first and third spinning solutions are both non-spinnable spinning solutions because the concentrations are lower than the spinnable concentration, but the three-chamber eccentric parallel structure can be collectively prepared by the three fluids. Moreover, compared with the application embodiment 1, because the flow is reduced and the polymer concentration is reduced, the total diameter of the fibers and the thickness of each chamber are reduced to a certain extent, and the batch production convenience and usefulness of the electrospinning process of the application for regulating the fiber diameter and the thickness of each chamber by parameters such as the polymer concentration and the flow are increased.

[0062] Embodiment 3

[0063] The embodiment provides a batch preparation method of three-chamber eccentric parallel structure nanofibers, and the preparation equipment and steps are similar to those of the embodiment 1, and the difference from the embodiment 1 is that:

[0064] The first spinning solution is an ethanol solution with 30% ethyl cellulose by mass percentage, which is prepared as follows: 300 g of ethyl cellulose powder is put into 700 g of ethanol, and stirred to dissolve, to obtain the spinning solution.

[0065] The second spinning solution is a 5% polyvinylpyrrolidone solution by mass percentage, which is prepared as follows: 50 g of polyvinylpyrrolidone is dissolved in 950 g of ethanol, to obtain the spinning solution.

[0066] The third spinning solution is a 75% (by volume) ethanol aqueous solution with 30% zein by mass percentage, which is prepared as follows: 300 g of zein is dissolved in 7000 g of ethanol solution, and stirred to dissolve, to obtain the spinning solution.

[0067] The flow rate of the first injector 8 is controlled to be 20 mL / h, the flow rate of the second injector 9 is controlled to be 20 mL / h, the flow rate of the third injector 10 is controlled to be 20 mL / h, the high-voltage generator 7 is turned on, the fiber plate receiving distance is adjusted to be 20 cm, the voltage is increased to 40 kV, and electrospinning is performed, to prepare the three-compartment eccentric parallel structure nanofiber from the combination of the first and second spinning solutions with spinning performance and the third spinning solution without spinning performance. See Figure 6 and Figure 7 The prepared three-compartment eccentric parallel structure nanofiber is collected uniformly and presents a good linear state, and the diameter of the nanofiber is 950 ± 260 nm, which reflects the three-compartment eccentric parallel structure characteristics, wherein the materials corresponding to the regions of different gray scales from left to right are zein, polyvinylpyrrolidone, and ethyl cellulose in turn, wherein the thickness of the zein on the left and right sides is about 290 nm, the thickness of the polyvinylpyrrolidone in the middle is about 160 nm, and the thickness of the ethyl cellulose on the right side is about 470 nm. Compared with the application example 1, the first and third spinning solutions are spinnable, and the second spinning solution is not spinnable because it is below the spinnable concentration, but it does not affect the batch preparation of the three-compartment eccentric parallel structure by the three fluids. Moreover, compared with the application example 1, because the concentrations of the first and third polymers are increased, and the concentration of the second polymer is decreased, the total diameter of the fiber is increased, and the relative thicknesses of the compartments are greatly different, the thickness of the polyvinylpyrrolidone in the middle is reduced, and the thicknesses of the ethyl cellulose on the right side and the zein on the left side are both increased. It is shown that by the electrospinning process of the application, the thicknesses of the compartments can be regulated by the relative differences in the polymer concentrations of the different compartments, to provide a nanometer structure support platform for the rich design and construction of multifunctional nanometer materials.

[0068] In summary, the application provides a preparation method and equipment of three-chamber eccentric parallel structure nanofiber. The insulation container and the series of metal capillary eccentric sleeve array passing through the insulation container are used as the microfluid control transportation unit of three kinds of spinning fluid respectively, a plurality of groups of three fluid parallel arranged and led out of the common outlet are arranged at the bottom of the insulation container, the three different fluids are synchronously guided into the high-voltage electrostatic field, the common outlet of the series of eccentric combination structure is used as the macroscopic template, under the high-voltage electrostatic field, the three spinning fluid streams are stretched into three-chamber eccentric parallel structure nanofiber in a few milliseconds through the interaction between the high-voltage electrostatic field and the fluid, so that the problem that the three-chamber eccentric parallel structure nanofiber with complete structure is difficult to prepare and difficult to realize industrial scale is solved. In addition, the preparation method can also freely regulate the structure parameters of the nanofiber itself, which is important for the functionalization of the nanofiber.

[0069] Those skilled in the art should understand that the skilled in the art can realize the variation examples in combination with the prior art and the above-mentioned embodiments, which are not described here. Such variation examples do not affect the essential content of the application, which are not described here.

[0070] The preferred embodiments of the application are described above. It should be understood that the application is not limited to the above specific embodiments, and the equipment and structures not described in detail should be understood as being implemented in the ordinary way in the art; any skilled person in the art can make many possible changes and modifications to the technical solutions of the application or modify equivalent embodiments without departing from the scope of the technical solutions of the application, which does not affect the essential content of the application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the application, without departing from the content of the technical solutions of the application, still belongs to the protection scope of the technical solutions of the application.

Claims

1. A method for preparing a three-compartment off-center side-by-side structure nanofiber, characterized by: Simultaneously electrospinning three kinds of spinning solutions; The first spinning solution and the second spinning solution are respectively divided into microfluidic leads through the array composed of two sets of series of metal capillary tubes from the respective collection inlets; the third spinning solution is divided into microfluidic leads from the several bottom through holes (41) of the insulating container (6); the outer diameter of the first series of metal capillary tubes is smaller than the outer diameter of the second series of metal capillary tubes, and the first series of metal capillary tubes are inserted into the second series of metal capillary tubes to form a series of metal capillary eccentric sleeve; the series of metal capillary eccentric sleeve penetrates through the insulating container (6) and extends 0.8-1.2 mm from the inside of the bottom through hole (41) of the insulating container (6) to form a combined eccentric outlet (4) of the three kinds of spinning solutions; the three kinds of spinning solutions are guided into a high-voltage electrostatic field in an eccentric parallel manner through the combined eccentric outlet (4) to form three-chamber eccentric parallel structure nanofibers in a single step.

2. The method of claim 1, wherein the three-compartment eccentric parallel structure nanofiber is prepared by the steps of: The part where the first series of metal capillary tubes are inserted into the second series of metal capillary tubes is sealed by sealing glue.

3. The method for preparing a three-chambered eccentric parallel structure nanofiber according to claim 1, characterized in that, The thickness of each chamber in the three-chamber eccentric parallel structure nanofiber is controlled by the polymer concentration in the corresponding spinning solution and / or the absolute flow rate of the corresponding spinning solution and the relative flow rate of each spinning solution.

4. The method for preparing a three-chambered, eccentrically aligned, parallel-structured nanofiber according to claim 1, characterized in that, The center distance of the several bottom through holes in the insulating container is 2-5 cm.

5. The method for preparing a three-chambered, eccentrically aligned, parallel-structured nanofiber according to claim 1, characterized in that, The steps of the high-voltage electrospinning include: The first syringe is installed on the first syringe pump, and the outlet of the first syringe is connected with the inlet of the insulating container through a liquid outlet pipe; the second syringe is installed on the second syringe pump, and the outlet of the second syringe is connected with the inlet end of the first series of metal capillary tubes through a liquid outlet pipe; the third syringe is installed on the third syringe pump, and the outlet of the third syringe is connected with the inlet end of the second series of metal capillary tubes through a liquid outlet pipe; The fiber receiving plate is arranged directly below the insulating container, and the high-voltage generator is electrically connected with the first series of metal capillary tubes and the second series of metal capillary tubes; the surface of the fiber receiving plate is made of conductive material; the fiber receiving plate and the high-voltage generator are both grounded; The first syringe, the second syringe and the third syringe are respectively added with spinning solutions, and the first syringe pump, the second syringe pump, the third syringe pump and the high-voltage generator are started to prepare three-chamber eccentric parallel structure nanofibers in a single step through the action of a high-voltage electrostatic field.

6. The method of claim 5, wherein the three-compartment eccentric parallel structure nanofiber is prepared by the steps of: The first spinning solution is an ethanol solution of 10-30wt% ethyl cellulose; the second spinning solution is an ethanol solution of 5-12wt% polyvinylpyrrolidone; and the third spinning solution is a 75vol% ethanol aqueous solution of 15-30wt% zein; The flow rate of the first syringe is 5-20 mL / h, the flow rate of the second syringe is 5-20 mL / h, and the flow rate of the third syringe is 5-20 mL / h; The receiving distance of the fiber receiving plate is 10-20 cm, and the output voltage of the high-voltage generator is 25-40 kV.

7. The method of claim 6, wherein the three-compartment eccentric parallel structure nanofiber is prepared by the steps of: The first spinning solution is an ethanol solution of 25wt% ethyl cellulose; the second spinning solution is an ethanol solution of 8wt% polyvinylpyrrolidone; and the third spinning solution is a 75vol% ethanol aqueous solution of 20wt% zein; The flow rate of the first injector is 10 mL / h, the flow rate of the second injector is 10 mL / h, and the flow rate of the third injector is 10 mL / h. The receiving distance of the fiber receiving plate is 15 cm, and the output voltage of the high-voltage generator is 34 kV.

8. An apparatus for preparing a tri-compartment eccentric side-by-side structure nanofiber, characterized by, The high-voltage electrospinning device comprises a first series of metal capillary tubes (51), a second series of metal capillary tubes (52), and an insulating container (6). The first spinning solution is microfluidically introduced through the array of the first series of metal capillary tubes (51). The second spinning solution is microfluidically introduced through the array of the second series of metal capillary tubes (52). The third spinning solution is microfluidically introduced through the bottom through holes (41) of the insulating container (6). The first series of metal capillary tubes (51) are inserted into the second series of metal capillary tubes to form a series of metal capillary eccentric sleeve tubes. The series of metal capillary eccentric sleeve tubes penetrate through the insulating container (6) and extend 0.8-1.2 mm from the bottom through holes (41) of the insulating container (6) to form a combined eccentric outlet (4) for the three spinning solutions.

9. The apparatus of claim 8, wherein the apparatus further comprises a third chamber. The insulating container (6) serves as the basket body of a basket, and the series of metal capillary eccentric sleeve tubes are uniformly inserted into the basket body.

10. The apparatus of claim 8, wherein the apparatus further comprises a third chamber. The insulating container (6) is sealed by an insulating layer at the penetration points of the first series of metal capillary tubes (51) and the second series of metal capillary tubes (52).

Images