CN104451912A - Preparing device and method for forming micro-nanofiber - Google Patents

Abstract

The invention provides a preparation device and method for forming micro-nano fibers, belonging to the field of biological materials and tissue engineering. In the present invention, the electrospinning nozzles are used to prepare parallel holes of different sizes on a nozzle, and the electrospinning stock solution is injected into the electrospinning nozzle through a micro-injection pump, and the parallel nozzle holes in the electrospinning nozzle are simultaneously formed by applying a high voltage. Multiple Taylor cones are used to obtain electrospun precursors of different sizes in a single step, and effectively improve the yield of electrospun precursors to prepare micro-nano fibers. Electrospinning by this method can increase the yield of electrospinning, which is obviously higher than that of single-needle electrospinning; at the same time, it is an effective means to solve the regulation of spinning fiber diameter, and obtain relatively uniform/different size distribution of micro-nano fibers, fiber diameter The controllable range is 50nm-1mm, which effectively improves the yield and size control problems in the field of electrospinning micro-nano fibers.

Description

Preparation device and method for forming micro-nano fibers

technical field

The invention belongs to the field of electrospinning micro-nano fiber engineering, and relates to a preparation method of nano-fibers and a technology for preparing different micro-nano fibers by electrospinning nozzle electrostatic spinning technology.

Background technique

Electrospinning technology is one of the methods for preparing micro-nano fibers, and the diameter of the prepared fibers can reach nanometer scale. The electrospinning system mainly includes the following parts: high voltage source, nozzle needle, and ground collector. The key principle of electrospinning is to apply a high voltage to the polymer solution, so that the polymer solution forms a Taylor cone at the nozzle nozzle. As the voltage continues to increase, the charged liquid forms a jet at the tip of the Taylor cone. As the jet falls, fibers are formed as the solvent evaporates and fall onto the collector due to electrostatic forces. The collected polymer film forms a randomly arranged structure due to the disordered movement of the fibers when they fall. Non-woven fabrics made of electrospun fibers have the advantages of high porosity, large specific surface area, high fiber fineness and uniformity, and large aspect ratio. These preparation advantages are characteristics that cannot be obtained by other preparation methods, endowing electrospun fibers with a wide range of application prospects. For example, it can be used as a bioscaffold in biomaterials. It has appropriate mechanical strength, can induce cell growth and differentiation, can be degraded and absorbed by the human body, and has biocompatibility. It has been widely used in human tissue repair and treatment.

In the international electrospinning as a method of preparing nanofibers, the low yield is the most significant drawback and also limits the feasibility of mass production and fabrication. Therefore, some researchers have conducted research on multi-channel electrospinning devices to improve the yield of electrospinning. Yasmin Srivastava et al. (Srivastava, Y., et al., Electrospinning of hollow and core/sheath nanofibers using a microfluidic manifold. Microfluidics and Nanofluidics, 2007. 4(3): p. 245-250) used semiconductor devices to prepare microfluidics For PDMS components, a parallel electrospinning device with branched microchannel structures and coaxial nozzles was designed to obtain hollow nanofibers and composite nanofibers. The equipment successfully increased the yield to produce PVP and TiO ₂ mixture hollow fibers and PPy/PVP hybrid fibers with diameters between 100 and 250 nm. Yarin, AL and others (Yarin, AL and E. Zussman, Upward needleless electrospinning of multiple nanofibers. Polymer, 2004. 45(9): p. 2977-2980) mixed magnets and silicone resin oil to make a magnet fluid, using permanent magnets A magnetic field is generated to induce the formation of lance-like protrusions on the surface of the fluid, then a polymer solution is added to the fluid, the solution is left on the surface of the magneto-silicon-oil mixture, a high voltage is applied to the mixture, and a conductive grounded metal is used to collect the fibers. In the US patent application US6616435 B2, the researchers used a single syringe pump to deliver the polymer solution or molten polymer material into seven syringes, and applied a voltage for electrospinning, while the collector below moved from side to side at a certain speed Collect and form a uniform fiber web. This kind of electrospinning is relatively stable and effectively increases the output of electrospun fibers. These devices have improved the yield of electrospinning to a certain extent. Due to the low yield of single-needle electrospinning, it needs to be improved by matching several syringe pumps and needles, or using multi-channel electrospinning devices prepared by micro-nano processing, most of which are complicated and expensive to manufacture. , which is a certain obstacle to the realization of the industrialization of electrospinning to prepare micro-nano fibers.

On the other hand, electrospinning can form continuous fibers by applying an electric field to a polymer solution or melt under the action of an electric field. Controlling the obtained electrospinning diameter is a key technology and has also affected the application field. The current diameter control method can be obtained by changing the applied voltage, spinning distance, dope concentration, injection flow rate and control current to obtain the control of the spinning diameter. In order to effectively change the square filament diameter or obtain different spinning diameter distributions in the spinning operation, the above parameters (voltage, spinning distance, spinning solution concentration, injection flow rate and control current) must be fixed, and then the parameters must be changed. A parameter of 2000 obtains different spinning diameters, so simultaneous (simultaneous) spinning with different diameters cannot be effectively obtained. Due to the need to change the control parameters for the preparation of fibers with different diameter distributions, and the inability to prepare fibers with different diameters at the same time, the simultaneous spinning of different diameters has also formed certain obstacles to the industrial application of electrospinning to prepare micro-nano fibers.

Contents of the invention

In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a preparation device and a preparation method for forming micro-nano fibers.

A preparation device for forming micro-nano fibers, which includes a high-voltage power supply, a syringe pump, an electrospinning nozzle, and a receiving and curing device; the syringe pump is connected to the electrospinning nozzle, and the electrospinning nozzle is connected to a high-voltage power supply.

The electrospinning nozzle has a hollow inner diameter, and at least two nozzle holes are arranged side by side. The electrospinning stock solution flows to the outlet of the nozzle hole through the hollow inner diameter. Taylor cone, below which micro- and nanofibers are produced and collected.

In the electrospinning nozzle, at least two nozzle holes are arranged side by side, and the nozzle holes may be composed of the same size or different sizes.

A method for preparing shaped micro-nano fibers according to the preparation device, the steps are as follows:

1) The polymer solution is used as the electrospinning stock solution, and injected into the electrospinning nozzle through a syringe pump;

2) Apply a high voltage between the electrospinning nozzle and the receiving and curing device, so that multiple Taylor cones are formed at the exit of the pinhole at the same time, and polymer micro-nano fibers are produced;

3) Collect the nanofibers prepared in step 2) by receiving and curing the device.

The diameter of the nanofiber is 50nm-1mm.

The electrospinning stock solution is selected from the following materials: organic substances, inorganic substances, or organic/inorganic composites; the organic substances include: polyether, polyphenylene ether, polyanhydride, polythiophene, polyaniline, polyamide, polyamide Imine, polyester, polyurethane, epoxy resin, polyolefin, polyhaloolefin, polystyrene, polyparastyrene, polyoxyethylene, polyethyleneimine, sodium polystyrene sulfonate, polyethylene oxide , polymethyl acrylate, poly-p-phenylenediamine terephthalate, polyvinyl acetate, polyacetylene, polyglycolic acid, polyacrylic acid, polylactic acid, polylactic acid-glycolic acid copolymer, polyvinylpyrrolidone, polyethylene Glycol, polyvinyl alcohol, polymethylsilsesquioxane, polyε-caprolactone, polybutyrolactone, polyvalerolactone, polypyrrole, poly-α-amino acid, methylcellulose, ethylcellulose Sodium carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl methyl cellulose terephthalate, cellulose terephthalate, starch and Its derivatives, fibrin, silk protein, chitin, chitosan, chondroitin sulfate, collagen, gelatin, hydrogel, hyaluronic acid and its copolymers, derivatives or mixtures; inorganic substances include: Al ₂ O ₃ , CuO, NiO ₂ , SiO ₂ , GeO ₂ , V ₂ O ₅ , Mn ₂ O ₃ , Mn ₃ O ₄ , ZrO ₂ , ZnO, Co ₃ O ₄ , Nb ₂ O ₅ , MgTiO ₃ , PdO, CeO ₂ , BaTiO ₃ , La ₂ CuO ₄ , SnO ₂ , NiFe ₂ O ₄ , Fe ₃ O ₄ , NiTiO ₃ .

Further, auxiliary materials are added to the electrospinning stock solution to obtain micro-nano fiber-coated auxiliary materials, and the ratio of the auxiliary materials is selected according to different requirements.

The auxiliary materials are magnetic particles and quantum dots; the magnetic particles include: Fe, Co, Ni, Mn, MeFe ₂ O ₄ , Me=Co, Ni, Mn, Fe ₃ O ₄ nanoparticles, Fe ₂ O ₃ Nanoparticles; the quantum dots include: carbon quantum dots, CdS, CdSe, CdTe, ZnSe, InP, InAs.

The auxiliary material is a dye, and the dye is selected from the following materials: disperse dyes, fluorescent dyes, ice dyes, cationic dyes, sulfur dyes, phthalocyanine dyes, reactive dyes, direct dyes, acid dyes, basic dyes, Polycondensation dyes, vat dyes, photoluminescent dyes.

The auxiliary materials are anisotropic nanoparticles.

The auxiliary material is a high atomic number metal, and the high atomic number metal includes: Au, Ag, Pt, Zn, Ti.

The beneficial effects of the present invention are: compared with the prior art, the device is simple, only by placing more than two nozzle holes in parallel on the electrospinning nozzle, the effect of multi-channel jetting can be achieved, and high yield can be obtained for the preparation of nanofibers; On the other hand, by changing the nozzle size of the electrospinning nozzle, the synchronous realization of different spinning diameters can be achieved in a single step, and fiber spinning with a diameter of micron to nanometer can be obtained, which can be used for biological scaffolds and other fields; significantly improve the production rate and diameter preparation problems of existing electrospinning, and provide the possibility for its industrial production.

Description of drawings

The utility invention is further described below in conjunction with accompanying drawing and embodiment:

Fig. 1 is a schematic diagram of an electrospinning two-hole electrospinning nozzle having the same diameter nozzle hole;

Figure 2 is a schematic diagram of a two-hole device system with the same diameter for electrospinning;

Fig. 3 is a schematic diagram of an electrospinning four-hole electrospinning nozzle with the same diameter orifice device;

Figure 4 is a schematic diagram of a four-hole device system with the same diameter for electrospinning;

Fig. 5 is a schematic diagram of an electrospinning four-hole electrospinning nozzle with different diameters of orifices;

Figure 6 is a schematic diagram of a four-hole device system with different diameters for electrospinning;

Fig. 7 is an optical micrograph of polyvinyl alcohol fiber obtained by four-hole electrospinning.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope of the appended claims of the present application.

The invention specifically includes: an electrospinning nozzle, the needle has more than two parallel nozzle holes, the electrospinning stock solution can flow out through the nozzle holes of the electrospinning nozzle, and the liquid flowing out of the nozzle holes under the action of an electric field forms a Taylor cone , to obtain the preparation of micro-nanofibers. Among them, the electrospinning nozzle has a plurality of parallel orifices with different apertures, which can simultaneously prepare micro-nano fibers of different scales, or the electrospinning nozzle has multiple identical parallel orifice devices to increase the yield of micro-nano fibers. The selection of the liquid used in the preparation of fiber materials (including the selection of carrier materials, solvents, drugs, dyes, and other auxiliary materials) can be combined with the selection of different control parameters to regulate the size, diameter, surface characteristics and shape of electrospun fibers .

The technical solution adopted by the present invention to solve its technical problems is: use the electrospinning nozzle to match different electrospinning stock solutions, such as polyvinyl alcohol aqueous solution (can add 0.2% sodium chloride) as the electrospinning stock solution, and inject it in one direction through a micro-injection pump In the electrospinning nozzle; a high voltage is applied between the parallel nozzle holes and the flat collector, so that the porous nozzle holes simultaneously form multiple Taylor cones and produce nanofibers with a higher yield; the prepared nanofibers are collected by receiving and curing devices fiber.

In the above method, the mass fraction of polyvinyl alcohol in the solution is 10-12%, the feed rate of the solution is 0.1-2.0ml/h, the distance between the electrospinning nozzle and the collector is 4-12cm, and the voltage is 3-2.0ml/h. 19kV.

The above method uses an electrospinning device (Fig. 2) consisting of a high-voltage electrostatic generator, an electrospinning liquid syringe, a syringe pump, an electrospinning nozzle (Fig. 1) and a receiving device. Spinneret connection. The specific operation is as follows: connect the 10% polyvinyl alcohol aqueous solution to the spinning nozzle (outer diameter*wall thickness: 2.0*0.15mm) through the 5mL injection syringe and the silica gel thin tube, The polyvinyl alcohol aqueous solution is fed to the silk nozzle, which is sprayed out from the two nozzle holes (0.8mm in diameter and 6mm in hole distance) of the electrospinning nozzle, and the feed rate of polyvinyl alcohol is controlled by a micro injection pump to 0.1ml/L . The electrospinning nozzle is connected with a high-voltage electrostatic generator, the upper electrode is fixed at the injection needle, and the lower electrode is a metal ring. When the electrostatic force is greater than the surface tension of the solution, the solution is stretched, and at the nozzle hole of the electrospinning nozzle A Taylor cone forms and a jet stream forms below. The solvent evaporates during the spraying process, and finally the solidified polyvinyl alcohol fibers are collected on the collecting device. By adding a certain proportion of sodium chloride to the electrospinning stock solution, the diameter of the collected fibers can be reduced.

The average diameter of the polyvinyl alcohol fiber prepared by the above method is 10 μm, and the diameter of the fiber can be controlled by adjusting parameters such as nozzle aperture, solution concentration, electrospinning voltage, solution feed rate and collection distance. The electrospinning nozzle can obtain higher yield, and the obtained nanofiber has better diameter uniformity and high porosity, and is suitable for cell attachment and growth.

Another technical solution adopted by the present invention to solve its technical problems is: to prepare micro-nano fibers of different diameters in a single step with an electrospinning nozzle, such as an aqueous solution of polyvinyl alcohol (with 0.2% sodium chloride added) as the electrospinning stock solution, through The micro-injection pump is injected into the electrospinning nozzle in one direction; the polyvinyl alcohol aqueous solution with a concentration of 10% is connected to the spinning nozzle (outer diameter*wall thickness: 2.0*0.15mm) through a 5mL injection syringe through a thin silica gel tube, and injected The syringe feeds the polyvinyl alcohol aqueous solution to the electrospinning nozzle at an appropriate rate, and it is sprayed out from the two nozzle holes (0.2mm and 0.8mm in diameter and 6mm in hole distance) of the electrospinning nozzle, and the polyvinyl alcohol solution is controlled by a micro-injection pump. The feed rate of vinyl alcohol was 0.1 ml/L. The electrospinning nozzle is connected with a high-voltage electrostatic generator, the upper electrode is fixed at the injection needle, and the lower electrode is a metal ring. When the electrostatic force is greater than the surface tension of the solution, the solution is stretched, and at the nozzle hole of the electrospinning nozzle A Taylor cone is formed and a jet flow is formed below, so that multiple parallel nozzle holes with different diameters form multiple Taylor cones at the same time to obtain fibers with different diameters, and finally the solidified polyvinyl alcohol fibers are collected on the collecting device. The polyvinyl alcohol fiber prepared by the above method has a diameter of 50nm-30μm, and can obtain different fiber diameters and pores in a single step with parameters such as fixed solution concentration, electrospinning voltage, solution feed rate and collection distance. High rate, suitable for cell attachment and growth.

Example 1

Weigh 3g of polyvinyl alcohol, dissolve it in 27g of ultrapure water, and stir magnetically at 150°C for 30 minutes to obtain a transparent solution; then add 0.06g of sodium chloride and stir magnetically at 150°C for 20 minutes to obtain a pure spinning solution.

The prepared pure spinning solution was sucked into 5mL syringes respectively, and the syringes were connected to the two-hole electrospinning nozzle with the same diameter orifice device (shown in Figure 1) through a silicone tube. Connect the positive side of the high voltage power supply to the needle and the negative side to the ferrule. Adjust the flow rate of the two syringe pumps to 0.15mL/h and the receiving distance to 4cm, then turn on the high-voltage power supply and set the voltage to 15kV to collect electrospun fibers with a double yield (as shown in Figure 2).

Example 2

Weigh 3g of polyvinyl alcohol, dissolve it in 27g of ultrapure water, and stir magnetically at 150°C for 30 minutes to obtain a transparent solution; then add 0.06g of sodium chloride and stir magnetically at 150°C for 20 minutes to obtain a pure spinning solution.

The prepared pure spinning solution was sucked into 5mL syringes respectively, and the syringes were connected to the four-hole electrospinning nozzle with the same diameter nozzle hole device (shown in Figure 3 ) through a silicone tube. Connect the positive side of the high voltage power supply to the needle and the negative side to the ferrule. Adjust the flow rate of the two syringe pumps to 0.25mL/h and the receiving distance to 4cm, then turn on the high-voltage power supply and set the voltage to 18kV to collect electrospun fibers with a 4-fold yield (as shown in Figure 4).

Example 3

Weigh 3g of polyvinyl alcohol, dissolve it in 27g of ultrapure water, and stir it magnetically at 150°C for 30min to obtain a pure spinning solution.

The prepared pure spinning solution was sucked into 5mL syringes respectively, and the syringes were connected to the four-hole electrospinning nozzles with different diameters of nozzles through silicone tubes (shown in Figure 5). Connect the positive side of the high voltage power supply to the needle and the negative side to the ferrule. Adjust the flow rate of the two syringe pumps to 0.1mL/h and the receiving distance to 6cm, then turn on the high-voltage power supply and set the voltage to 18kV to collect electrospun fibers with different diameters at the same time (as shown in Figure 6).

Example 4

Weigh 3g of polyvinyl alcohol, dissolve it in 27g of ultrapure water, and stir magnetically at 150°C for 30min to obtain a transparent solution.

The prepared spinning solutions were sucked into 5mL syringes respectively, and the syringes were connected to 5-hole needles through silicone tubes. Connect the positive side of the high voltage power supply to the needle and the negative side to the ferrule. Adjust the flow rate of the two syringe pumps to 0.35mL/h and the receiving distance to 6cm, then turn on the high-voltage power supply and set the voltage to 18kV, and the electrospun fibers can be collected (as shown in Figure 7).

Claims (10)

1. A preparation device for forming micro-nano fibers, characterized in that it includes a high-voltage power supply, a syringe pump, an electrospinning nozzle, and a receiving and curing device; the syringe pump is connected with the electrospinning nozzle, and the electrospinning nozzle is connected to the electrospinning nozzle High voltage power supply is connected. 2. The preparation device according to claim 1, wherein the electrospinning nozzle has a hollow inner diameter, at least two nozzle holes are arranged side by side, and the electrospinning stock solution flows to the outlet of the nozzle hole through the hollow inner diameter. Under the action of the electric field of the power supply, more than two Taylor cones are formed at the outlet of the nozzle hole at the same time, and micro-nano fibers are prepared and collected below. 3. A preparation device according to claim 2, characterized in that at least two nozzle holes of the electrospinning nozzle are arranged side by side, and the nozzle holes can be formed in parallel by the same size, or the nozzle holes can be formed in parallel by different sizes . 4. A method for preparing micro-nano fibers according to the preparation device according to claim 2, characterized in that the steps are as follows: 1) The polymer solution is used as the electrospinning stock solution, and injected into the electrospinning nozzle through a syringe pump; 2) Apply a high voltage between the electrospinning nozzle and the receiving and curing device, so that multiple Taylor cones are formed at the exit of the pinhole at the same time, and polymer micro-nano fibers are produced; 3) Collect the nanofibers prepared in step 2) by receiving and curing the device. 5. The method according to claim 3, wherein the electrospinning stock solution is selected from the following materials: organic matter, inorganic matter, or organic/inorganic compound; the organic matter includes: polyether, polyphenylene ether , polyanhydride, polythiophene, polyaniline, polyamide, polyimide, polyester, polyurethane, epoxy resin, polyolefin, polyhalogenated olefin, polystyrene, polyparastyrene, polyoxyethylene, polyethylene Imine, sodium polystyrene sulfonate, polyethylene oxide, polymethyl methacrylate, poly-p-phenylene terephthalate, polyvinyl acetate, polyacetylene, polyglycolic acid, polyacrylic acid, polylactic acid , polylactic acid-glycolic acid copolymer, polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, polymethylsilsesquioxane, polyε-caprolactone, polybutyrolactone, polyvalerolactone, polypyrrole , poly-alpha-amino acid, methyl cellulose, ethyl cellulose, sodium carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl terephthalate Methylcellulose, cellulose terephthalate, starch and its derivatives, fibrin, silk protein, chitin, chitosan, chondroitin sulfate, collagen, gelatin, hydrogel, hyaluronic acid and its copolymer substances, derivatives or mixtures; inorganic substances include: Al ₂ O ₃ , CuO, NiO ₂ , SiO ₂ , GeO ₂ , V ₂ O ₅ , Mn ₂ O ₃ , Mn ₃ O ₄ , ZrO ₂ , ZnO, Co ₃ O _4. Nb ₂ O ₅ , MgTiO ₃ , PdO, CeO ₂ , BaTiO ₃ , La ₂ CuO ₄ , SnO ₂ , NiFe ₂ O ₄ , Fe ₃ O ₄ , NiTiO ₃ . 6. The method according to claim 4, characterized in that, further, adding auxiliary materials to the electrospinning stock solution to obtain micro-nanofiber-coated auxiliary materials, and the ratio of the auxiliary materials is selected according to different requirements. 7. The method according to claim 6, wherein the auxiliary materials are magnetic particles and quantum dots; the magnetic particles include: Fe, Co, Ni, Mn, MeFe ₂ O ₄ , Me=Co, Ni, Mn, Fe ₃ O ₄ nanoparticles, Fe ₂ O ₃ nanoparticles; the quantum dots include: carbon quantum dots, CdS, CdSe, CdTe, ZnSe, InP, InAs. 8. The method according to claim 6, wherein the auxiliary material is a dye, and the dye is selected from the following materials: disperse dyes, fluorescent dyes, ice dyes, cationic dyes, sulfur dyes, phthalocyanines Dyes, reactive dyes, direct dyes, acid dyes, basic dyes, polycondensation dyes, vat dyes, photoluminescent dyes. 9. The method according to claim 6, wherein the auxiliary material is anisotropic nanoparticles. 10. The method according to claim 5, wherein the auxiliary material is a high atomic number metal, and the high atomic number metal includes: Au, Ag, Pt, Zn, Ti.