CN111575917A - A kind of honeycomb structure nanofiber material with high specific surface area and preparation method thereof - Google Patents

Abstract

The invention relates to a kind of honeycomb structure nanofiber material with high specific surface area and a preparation method thereof. As a receiving substrate, a honeycomb-like nanofiber material with a high specific surface area is prepared; the final material has a certain thickness, a microscopic three-dimensional honeycomb-like connected pore structure, the pore is a conical straight through pore, and the pore diameter at the large end of the pore is 20-100 μm , the diameter of the small end of the channel is 5-25 μm, the single fiber is beaded and rough and porous, and the specific surface area is greater than 600 m ² /g. The invention does not need a template, and can prepare nanofiber materials with a three-dimensional honeycomb-like connected pore structure in one step, and the prepared honeycomb-like structure nanofiber material has conical straight-through pores, so that the water vapor can realize rapid directional transmission in the thickness direction, and the orientation of communication in the pore wall Fiber effectively promotes the horizontal diffusion of water, and has broad application prospects in the field of water conduction and dehumidification.

Description

A kind of honeycomb structure nanofiber material with high specific surface area and preparation method thereof

technical field

The invention belongs to the technical field of nanofiber materials, and relates to a high specific surface area honeycomb structure nanofiber material and a preparation method thereof.

Background technique

The fiber materials prepared by traditional electrospinning technology are mostly two-dimensional fiber membranes, and the internal fibers are randomly oriented and stacked. The use of electrospinning technology to construct a three-dimensional honeycomb-shaped interconnected pore structure nanofiber material can effectively reduce the resistance of water vapor transmission, and is expected to greatly improve the water conductivity and water capacity of the material. It has a wide range of applications in the field of water conduction and dehumidification prospect.

Literature [Patterned, highly stretchable and conductive nanofibrous PANI/PVDF strain sensors based on electrospinning and in situ polymerization, Nanoscale, 2016, 8, 2944-2950] reported the use of a metal grid frame as a receiving substrate and its induction of jets A fiber material with a square through-hole structure is prepared by the method. The through-hole diameter of the fiber material prepared by the method is about 1.5 mm, and the patterned nanofiber membrane has a good application prospect in the field of flexible electronics.

The literature [Honeycomb-like polysulphone/polyurethane nanofiber filter for the removal of organic/inorganic species from air streams, Journal of Hazardous Materials, 2018, 347, 325-333] reported the use of honeycomb template as a receiving substrate and collected on its surface Polysulfone/polyurethane electrospun fiber material with pore structure (pore diameter ~5mm).

The literature [Patterning electrospun nanofibers via agarose hydrogel stamps to spatially coordinate cell orientation in microfluidic device, Small, 2017, 13, 1-7] utilizes the shielding effect of circular array baffles on the electric field to obtain fiber materials with circular through-hole structure.

The above technologies all use a specially designed collection device to prepare through-hole structure fiber materials. However, due to the limitation of the hole size of the collection device, it is difficult to obtain a small-sized (pore diameter < 100 μm) through-hole structure, and single or multiple polymers are used for static electricity. The fiber material with through-hole structure obtained by spinning has an active low specific surface (less than 20 m ² /g), which cannot endow the material with excellent unidirectional moisture-conducting and moisture-absorbing and quick-drying properties.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problems existing in the prior art, to provide a high specific surface area honeycomb structure nanofiber material with excellent unidirectional moisture conduction and moisture absorption and quick drying performance and a preparation method thereof, in particular to provide a kind of nanofiber material suitable for extensive polymerization The range of raw materials, the range of specific functional metal-organic frameworks, the one-step preparation of small-sized through-hole structures with regular pore size and uniform distribution without templates, and the electrospinning of high specific surface area nanofiber materials with excellent unidirectional moisture conduction and moisture absorption and quick drying performance silk technology.

For achieving the above object, the technical scheme adopted in the present invention is as follows:

A preparation method of a honeycomb-like structure nanofiber material with high specific surface area, which comprises electrospinning a polymer solution dispersed with a nanoscale metal-organic framework, and using an insulating material subjected to de-charge treatment as a receiving substrate to obtain a high Honeycomb-like nanofiber material with specific surface area;

Usually, nano-sized metal-organic frameworks mixed with polymers are more suitable for electrospinning, because electrospinning fibers are mostly nanofibers; -Organic frameworks are not easy to be ejected by electrospinning technology, and are not easy to be combined with nanofibers; therefore, nano-sized metal-organic frameworks are more suitable for the preparation of honeycomb-like nanofiber materials by electrospinning technology; The size can be adjusted in the synthesis process, and those skilled in the art can adjust the nanoscale metal-organic framework of the corresponding size according to the needs;

The viscosity range of the polymer solution dispersed with the nano-scale metal-organic framework is 1-500 mPa·s, and the conductivity range is 100-10000 μS/cm; the electrospinning in the present invention refers to the low-viscosity solution under a high-voltage electrostatic field. Extrusion, the jet spreads out in the form of a spray. The viscosity of the spinning solution used in the present invention is extremely low, which is almost the lowest limit of the viscosity of the spinnable degree. There is a clear difference;

The process parameters of electrospinning include: voltage 10-40kV, perfusion speed 0.5-4mL/h, distance between spinneret and receiving substrate 6-20cm, and ambient relative humidity 30-60%;

The insulating material is a non-woven fabric or an electrospinning fiber film, which is obviously different from the honeycomb template in the prior art. The present invention does not need a honeycomb template, and only needs to use an ordinary non-woven fabric or an electrospinning fiber film as the receiving substrate;

The method of de-charge treatment is as follows: the insulating material is placed in a de-charge solvent for a period of time and then dried. The solvent acts as a conductor to eliminate static electricity on the substrate and remove the residual charge on the surface of the substrate, so that the formed honeycomb-like structure is obvious.

The reason why the present invention can make the material with excellent unidirectional moisture-conducting and moisture-absorbing and quick-drying properties is because:

In the invention, the metal-organic framework is added to the spinning solution, and the metal-organic framework can be taken out by the polymer during the spinning process, so that the single fiber has a bead-like rough porous structure, and the self-assembly of the porous fiber will obtain an ultra-high ratio Honeycomb-like nanofiber material with surface area and high porosity, the structural characteristics of ultra-high specific surface area and high porosity can improve the capillary effect of the material, greatly increase its contact area with air, and enhance the moisture absorption and moisture conductivity of the material. Moisture diffusion speed and drying speed, which in turn endow the material with excellent unidirectional moisture conduction and moisture absorption and quick-drying properties. At the same time, the introduction of metal-organic framework makes the surface of nanofibers contain a large number of hydrophilic active sites, which can also improve the unidirectional moisture conduction and moisture absorption of the material. Quick drying performance.

In addition, the introduction of the metal-organic framework changed the bulk properties of the electrospinning solution. The increase in the conductivity of the spinning solution increased the surface charge density during the jet drafting process, and the electrostatic repulsion between the fibers deposited on the substrate increased, inducing fiber bundles. branching, promoting its rapid self-assembly to form a honeycomb-like structure.

The forming mechanism of the honeycomb-like nanofiber material is shown in Figure 4, and the details are as follows:

The high-voltage electrostatic field charges and deforms the spinning dope, forming pendant cone-shaped droplets at the end of the spinneret. When the repulsive force on the surface of the droplet exceeds its surface tension, tiny polymer jets will be sprayed and atomized on the droplet surface at a high speed, and the nano-scale metal-organic framework will be taken out with the polymer at the same time, and these jets will pass through a short distance. The high-speed stretching of the electric field force, the volatilization of the solvent, and the final deposition on the receiving substrate. In the process of electrospinning, under a high-voltage electric field, as the perfusion advances, the spinning solution is extruded into fibers, and the rate of electrostatic charging of the extruded fibers exceeds the rate of static dissipation, showing the accumulation of electrostatic charges on them. , forming charged fiber bundles. The forming of honeycomb-like stacking structure depends on the competitive effect of surface tension and electrostatic repulsion of charged fiber bundles. The forming process involves dynamic processes such as charged jet tensile deformation, aggregation into bundles, and fiber bundles branching and stacking. After the insulating material is de-charged, the charged fibers are randomly deposited on the substrate at the beginning, and the wet fibers that do not have time to volatilize will partially fuse to form fiber clusters. , the surface tension can promote some fibers near the contact point to merge into the fiber cluster, while the part far from the contact point bends outward due to the increase of electrostatic repulsion. (120° triangular-branched structure is the most stable). On this basis, the nanofibers deposited during the spinning process were stacked layer by layer to form a honeycomb-like structure composed of multiple branched fiber clusters.

The reason why the present invention controls "the viscosity range of the polymer solution dispersed with the nano-scale metal-organic framework is 1-500 mPa·s, and the conductivity range is 100-10000 μS/cm" is because: the bulk properties of the spinning solution (viscosity, Electrical conductivity) is a necessary condition for the formation of charged fiber bundles; if the viscosity of the spinning solution is high and the electrical conductivity is low, it still belongs to the category of electrospinning within the spinnability level, but compared with the low-viscosity solution, the high-viscosity solution is due to intermolecular. The friction force is higher, so it is more difficult to eject the jet from the droplet under the same electric field force, that is, the droplet is not easy to be split, and it is not easy to branch into fine fibers; the spinning solution with lower conductivity is under the high voltage electric field. The surface charge accumulation of the fiber bundle is difficult to occur, the surface charge density of the fiber decreases, the electrostatic repulsion between the fibers deposited on the substrate decreases, and the fiber bundle is not easily branched, which hinders the rapid self-assembly of the charged fiber bundle under the electrostatic field. It is not easy to generate a honeycomb-like network structure.

The reason why the present invention controls "voltage 10-40kV, perfusion speed 0.5-4mL/h, distance between spinneret and receiving substrate 6-20cm, ambient relative humidity 30-60%" is because: it determines whether a honeycomb-like honeycomb can be formed If the voltage is too low, the droplets cannot be split to form fine fibers, and the electric field strength at low voltage is low, the surface charge density of the fibers is reduced, the electrostatic repulsion between the fiber bundles deposited on the substrate is reduced, and the branching effect between fibers is weakened. , resulting in a reduction in the pore size of the honeycomb-like structure or even no patterning; the perfusion speed affects the shape of the Taylor cone (a pendant conical droplet formed by the charged liquid at the end of the capillary), and the perfusion speed is too low or too high, the Taylor cone will be unstable or When jumping occurs, the instability of the jet also increases, which affects the morphology and structure of the fiber and cannot be patterned; the change of the spinning distance (that is, the distance between the spinneret and the receiving substrate) changes the electric field strength, which in turn affects the charged fiber bundle. The charge density ultimately affects the size of the honeycomb pore size (which also determines the apparent degree of the honeycomb structure). If the spinning distance increases, the electric field strength will decrease, the charge density of the fibers will decrease, the electrostatic repulsion between fibers will decrease, and the branching effect between fibers will decrease. weakened, resulting in a reduction in the pore size of the honeycomb-like structure or even no patterning; humidity within this range can reduce the corona discharge and make the electric charge less likely to dissipate, resulting in an increase in the fiber charge density, thus making the inter-fiber static electricity deposited on the substrate. The repulsive force increases and competes with the surface tension to induce the self-assembly of the honeycomb-like structure. If the humidity is too high, the corona discharge is enhanced to dissipate the charge, and the fiber charge density decreases, which reduces the electrostatic repulsion between the fibers deposited on the substrate. Too little repulsion force cannot provide self-assembly.

The reason why the present invention controls "the receiving substrate is an insulating material that has undergone de-charge treatment" is because: when the positively charged fiber jet is sprayed on the negative receiver, the fiber deposition pattern is determined by the strength of the charge on the fibers and the distance between the deposited fibers. It is controlled by the electrostatic repulsion and surface tension of the wet fibers, the surface tension causes the wet fibers to fuse when they contact, and the electrostatic repulsion pulls the fused fibers apart. Receiving fibers with high charge strength resist newly received similarly charged fibers and drive them to conductive points on nearby receiving substrates for easier charge dissipation. The nanofibers trapped by the fiber clusters are stacked upward by electrostatic repulsion, so that the fiber clusters grow in height into the walls of a three-dimensional honeycomb-like structure. Therefore, the decharged insulating material plays a key role as a receiving substrate, and does not significantly change the charge intensity of the charged fiber bundles initially deposited on the substrate, making it stronger with the subsequently deposited charged fibers The electrostatic repulsion is favorable for the formation of patterned topologies. When the substrate receives the first layer of fibrous film, the charges of the deposited fibers still exist in the fibers to form charged fiber bundles, which compete with the subsequently deposited fibers of the same charge with surface tension and electrostatic repulsion. The selected base material of the present invention is an insulating material, which will not conduct the charges on the deposited charged fibers away, and retains the effect of electrostatic repulsion with the subsequently deposited fibers. If the substrate is not treated, the charge accumulated on the surface of the material cannot be leaked out, resulting in charge accumulation. The charge on the fibers deposited at the beginning will be partially neutralized, resulting in the competition between the surface tension of the charged fibers and the electrostatic repulsion. The effect is affected, and the final fibers are randomly and randomly distributed, that is, the conductive substrate is not easy to form honeycomb-like nanofibers, and the insulating material is not easy to form honeycomb-like nanofibers without treatment.

As the preferred technical solution:

The above-mentioned preparation method of a honeycomb-like nanofiber material with high specific surface area, the metal-organic framework is MIL-101(Cr), MIL-101(Cr)-NH ₂ , MIL-100(Fe), HKUST- 1. CAU-1(Al), CAU-23(Al), UiO-66, UiO-66-NH ₂ , KAUST-8, MOF-801, MOF-804, MOF-841, DUT-67(Zr), One or more of DUT-51(Zr), DUT-53(Zr), MOF-74(Mg) and MOF-74(Ni). There is no limitation on the type of metal-organic framework for preparing high specific surface area-like honeycomb-structured nanofiber material, and the metal-organic framework with hygroscopicity and water stability is selected according to the application field of the present invention.

The above-mentioned preparation method of a high specific surface area honeycomb structure nanofiber material, the polymer is polyacrylonitrile, polyurethane, cellulose acetate, polyvinyl alcohol, polylactic acid, polysulfone, polyethylene oxide, polyethylene Lactone, polyamide 6, polyamide 66, polyimide, polyethersulfone, polyethylene terephthalate, polystyrene sulfonic acid, polystyrene sulfonic acid sodium salt, polyacrylate, polyacrylic acid One or more of salt resin, polyethylene glycol, polyvinylpyrrolidone, thermoplastic polyurethane elastomer, chitosan, cellulose derivative and ion exchange resin.

The above-mentioned preparation method of a high specific surface area honeycomb structure nanofiber material, the solvent in the polymer solution is N,N-dimethylformamide, N,N-dimethylacetamide, chloroform, in tetrahydrofuran, N-methylpyrrolidone, chloroform, methanol, ethanol, isopropanol, deionized water, acetone, dichloromethane, formic acid, acetic acid, dimethyl sulfoxide, diethyl ether, toluene, trichloroacetic acid and trifluoroacetic acid of more than one.

The above-mentioned preparation method of a kind of honeycomb structure nanofiber material with high specific surface area, the preparation process of the polymer solution dispersed with nano-scale metal-organic framework is: firstly adding the metal-organic framework into the solvent, dispersing by ultrasonic After 1 to 4 hours, the polymer is added, and the mixture is continuously stirred for 2 to 24 hours at room temperature or at 50 to 90°C with a magnetic stirring device, where the room temperature is 23 to 26°C.

The above-mentioned preparation method of a honeycomb structure nanofiber material with high specific surface area, in the polymer solution dispersed with the nano-scale metal-organic framework, the mass content of the polymer is 3-15%, and the mass of the metal-organic framework is 3-15%. The content is 10-30%.

In the above-mentioned preparation method of a honeycomb-like nanofiber material with a high specific surface area, the process parameters of the electrospinning further include: an ambient temperature of 23-26°C.

In the above-mentioned preparation method of a honeycomb-like nanofiber material with a high specific surface area, the charge-eliminating solvent is deionized water and/or isopropanol, and the period of time is 1-3 minutes.

The present invention also provides a high specific surface area honeycomb structure nanofiber material prepared by the above-mentioned preparation method of a high specific surface area honeycomb structure nanofiber material, which has a certain thickness and a microscopic three-dimensional honeycomb-shaped connected pore structure, The pore channel is a conical straight through pore channel, the large end of the pore channel is far away from the substrate, the small end of the pore channel is close to the substrate, the diameter of the large end of the channel is 20-100 μm, the diameter of the small end of the channel is 5-25 μm, and the single fiber is beaded and rough and porous. Nanofiber materials with conical straight through-holes were prepared by electrospinning self-assembly molding technology, and a small-sized through-hole structure with regular pore size and uniform distribution can be obtained in one step without template.

As the preferred technical solution:

The high specific surface area honeycomb structure nanofiber material as described above, the thickness of the high specific surface area honeycomb structure nanofiber material is greater than 0.8mm, the specific surface area is greater than 600m ² /g, the porosity is greater than 75%, and the unidirectional moisture conductivity index is greater than 1300% , the moisture permeability is greater than 10kg/m ² /d, the present invention uses the moisture permeability to characterize the quick-drying performance of the product, the greater the moisture permeability, the better the quick-drying performance of the product.

Beneficial effects:

(1) Different from the traditional three-dimensional ordered fiber stacking structure based on the patterned receiving template method, the present invention utilizes electrostatic aggregation to form charged fiber bundles during the electrospinning process, and the charged fiber bundles compete in surface tension and electrostatic repulsion. Under the action, the honeycomb-like stacking structure is induced to self-assemble on the surface of the insulating receiving substrate, so as to realize the controllable preparation of the honeycomb-like structure nanofiber material with high specific surface area, and the fiber diameter, pore diameter and thickness are highly controllable; the present invention does not need a template, and can be One-step preparation of a nanofiber material with a high specific surface area having a three-dimensional honeycomb connected pore structure, the material has a small-sized through-hole structure with regular pore diameter and uniform distribution (the pore diameter of the large end of the pore channel is 20-100 μm, and the pore diameter of the small end of the pore channel is 5-25 μm) and Rough and porous beaded single fiber makes it have broad application prospects in the field of water conduction and dehumidification;

(2) Different from the preparation technology of traditional electrospinning pure polymer nanofiber membrane and polymer/metal-organic framework composite nanofiber membrane, the present invention adopts extremely low polymer mass concentration and extremely high metal-organic framework quality Concentration, i.e. low viscosity, high conductivity polymer/metal-organic framework mixture for electrospinning, the metal-organic framework further induces the accumulation of charges on the fiber surface, which facilitates the rapid self-assembly of charged fiber bundles under the electrostatic field. Honeycomb-like structure, that is to say, the introduction of the metal-organic framework makes the surface charge density of the fiber increase during the jet drafting process, which makes it easier to form branched nanofibers, and promotes the formation of honeycomb-structured nanofiber materials, and the present invention is applicable to polymers and The range of metal-organic framework raw materials is extremely wide;

(3) The specific surface of the traditional honeycomb-like nanofiber material is very low (less than 20 m ² /g), and the application is limited. The introduction of the metal-organic framework in the present invention significantly changes the single-fiber structure of the material, which is rough and porous in the form of beads. The honeycomb-like network structure composed of porous single fibers significantly improves the specific surface area and porosity of the material, and the honeycomb-like structure with ultra-high specific surface area significantly improves the moisture absorption and quick-drying properties of the material;

(4) The present invention uses the electrospinning technology and the charge elimination treatment method to prepare the polymer/metal-organic framework composite nanofiber material with honeycomb-like structure in one step for the first time. The thickness of the material can exceed 0.8mm, which breaks through the traditional electrospinning technology. The limitation of preparing two-dimensional nanofiber membranes enables the controllable construction of three-dimensional honeycomb-like interconnected pore-structured nanofibrous materials.

Description of drawings

Fig. 1 is the scanning electron microscope picture of the traditional electrospinning polymer nanofiber material;

Fig. 2 is the scanning electron microscope picture of traditional electrospinning polymer/metal-organic framework composite nanofiber material;

Figure 3 is a scanning electron microscope image of the electrospun honeycomb-like polymer/metal-organic framework composite nanofiber material. The left image is a micrograph at a larger magnification, while the right image is a micrograph at a smaller magnification. microphotos;

Figure 4 is a diagram showing the forming mechanism of the electrospinning honeycomb-like polymer/metal-organic framework composite nanofiber material.

Detailed ways

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

The polymers in Examples 1 to 9 are polyacrylonitrile (molecular weight is 20W), polyvinyl alcohol (molecular weight is 19.5W), cellulose acetate (acetyl 39.8wt%, hydroxyl 3.5wt%), polyurethane (molecular weight is 20W) , polylactic acid (molecular weight is 80W), polysulfone (molecular weight is 30W), polycaprolactone (molecular weight is 20W); solvent selects N,N-dimethylformamide, deionized water, acetone, dimethyl sulfoxide , N,N-dimethylacetamide, chloroform and chloroform are all produced by Shanghai Crystal Pure Reagent Co., Ltd.

Example 1

A preparation method of a honeycomb structure nanofiber material with high specific surface area, the specific steps are as follows:

(1) First, add MIL-101 (Cr) into N,N-dimethylformamide, ultrasonically disperse it for 3 hours, then add polyacrylonitrile to the above dispersion, and continuously stir it with a magnetic stirring device for 12 hours at room temperature to obtain Uniform and stable mixed solution, in which polyacrylonitrile accounts for 5% by mass of the mixed solution, MIL-101(Cr) accounts for 20% by mass of the mixed solution, the viscosity of the mixed solution is 30mPa·s, and the conductivity is 146.4 μS/cm;

(2) drying the non-woven fabric after placing it in deionized water for 3 minutes, the deionized water can be used as a conductor to eliminate static electricity, remove the residual charge on the surface of the non-woven fabric, and use the non-woven fabric after the deionization treatment as a receiving substrate;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 12kV, the perfusion speed was 1mL/h, the distance between the spinneret and the receiving substrate was 15cm, the ambient temperature was 24±1°C, and the ambient relative humidity was 46 ±3% to obtain a honeycomb-like nanofiber material.

The final high specific surface area honeycomb-like structure nanofiber material is shown in Figure 3. It has a certain thickness and a microscopic three-dimensional honeycomb-shaped connected pore structure. The pores are conical straight through pores. The large end of the pores is far away from the substrate, and the small ends of the pores are close to The base material, the diameter of the large end of the channel is 55±5μm, the diameter of the small end of the channel is 15±5μm, the single fiber is beaded and rough and porous; the thickness of the high specific surface area honeycomb structure nanofiber material is 1mm, and the specific surface area is 820m ² / g, the porosity is 85%, the unidirectional moisture conductivity index is 1402%, the moisture permeability is 11.6kg/m ² /d, and the moisture absorption and quick drying effect is good.

Comparative Example 1

A preparation method of nanofiber material, the specific steps are as follows:

(1) First, add MIL-101 (Cr) into N,N-dimethylformamide, ultrasonically disperse it for 3 hours, then add polyacrylonitrile to the above dispersion, and continuously stir it with a magnetic stirring device for 12 hours at room temperature to obtain Uniform and stable mixed solution, in which polyacrylonitrile accounts for 12% by mass of the mixed solution, MIL-101(Cr) accounts for 8% by mass of the mixed solution, the viscosity of the mixed solution is 900mPa·s, and the conductivity is 85.4 μS/cm;

(2) Use aluminum foil as the receiving substrate;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 12kV, the perfusion speed was 1mL/h, the distance between the spinneret and the receiving substrate was 15cm, the ambient temperature was 24±1°C, and the ambient relative humidity was 46 ±3% to obtain nanofibrous material.

The final nanofiber material is shown in Figure 2. Macroscopically, it is a two-dimensional fiber membrane with a thickness of only micrometers (100 μm). Microscopically, the fibers are randomly oriented and stacked, and the single fiber is rough and porous. MIL-101(Cr) Evenly distributed on the single fiber, this common ^two -dimensional structure limits its application in the field of water conduction and dehumidification.

Comparing Example 1 with Comparative Example 1, it can be seen that the content of polyacrylonitrile in the mixed solution of Example 1 is lower (leading to lower viscosity of the mixed solution), and the content of MIL-101 (Cr) is higher (leading to the mixed solution). The electrical conductivity is higher), the receiving substrate is an insulating material after charge elimination treatment, etc., which together lead to the formation of a honeycomb-like structure, resulting in the final nanofiber material having a certain thickness, microscopically in the form of a cone-shaped straight through fiber network. The pore channel, the single fiber is extremely fine and rough and porous, the MOF is distributed on the single fiber in the form of beads, and the conical straight through pore channel enables the rapid directional transmission of water vapor in the thickness direction. It has broad application prospects in the field of dehumidification.

Comparative Example 2

A preparation method of nanofiber material is basically the same as that of Comparative Example 1, except that the mixture does not contain MIL-101(Cr), the mass percentage of polyacrylonitrile in the solution is 12%, and the viscosity of the mixture is 500mPa s, the conductivity is 58.8 μS/cm.

Comparing Comparative Example 1 and Comparative Example 2, it can be seen that the mixed solution of Comparative Example 2 does not contain metal-organic frameworks, the conductivity of the solution is significantly reduced, and the receiving substrates are all conductive substrates of aluminum foil, resulting in the formation of a non-like honeycomb structure, The final nanofiber material is shown in Figure 1. Macroscopically, it is a two-dimensional fiber membrane with a thickness of only micrometers (80 μm). Microscopically, the fibers are randomly oriented and stacked, and the surface of the single fiber is smooth. This ordinary two-dimensional structure Limiting its application in the field of water conduction and dehumidification, the moisture permeability is 3.3kg/m ² /d, and it does not have unidirectional moisture conduction performance.

Comparative Example 3

A preparation method of nanofiber material, the specific steps are as follows:

(1) First, add MIL-101 (Cr) into N,N-dimethylformamide, ultrasonically disperse it for 3 hours, then add polyacrylonitrile to the above dispersion, and continuously stir it with a magnetic stirring device for 12 hours at room temperature to obtain Uniform and stable mixed solution, in which polyacrylonitrile accounts for 12% by mass of the mixed solution, MIL-101(Cr) accounts for 8% by mass of the mixed solution, the viscosity of the mixed solution is 900mPa·s, and the conductivity is 85.4 μS/cm;

(2) drying the non-woven fabric after placing it in deionized water for 3 minutes, the deionized water can be used as a conductor to eliminate static electricity, remove the residual charge on the surface of the non-woven fabric, and use the non-woven fabric after the deionization treatment as a receiving substrate;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 12kV, the perfusion speed was 1mL/h, the distance between the spinneret and the receiving substrate was 15cm, the ambient temperature was 24±1°C, and the ambient relative humidity was 46 ±3% to obtain nanofibrous material.

The final nanofiber material is a two-dimensional fiber film macroscopically, with a thickness of only micrometers (100 μm), microscopically, the fibers are randomly oriented and stacked, the single fiber is rough and porous, and MIL-101(Cr) is evenly distributed on the single fiber. , this ordinary two-dimensional structure limits its application in the field of water conduction and dehumidification, the moisture permeability is 3.4kg/m ² /d, and it does not have unidirectional moisture conduction performance.

Comparing Example 1 with Comparative Example 3, it can be seen that when the viscosity of the mixed solution is high (beyond the viscosity range of 1-500 mPa·s) and the conductivity is low (beyond the conductivity range of 100-10000 μS/cm), it is difficult to A honeycomb-like structure is formed because the surface charge repulsion of the droplets formed by the high-viscosity mixed liquid at the end of the spinneret is difficult to exceed its surface tension, and it is not easy to be ejected to form tiny fluids. The polymer content is large and the viscosity is high, and the obtained fibers are also thicker; the mixed solution with low conductivity is difficult to generate the surface charge accumulation of the fiber bundle under the high-voltage electric field, the charge density decreases, and the fibers deposited on the substrate are inter-fiber. The electrostatic repulsion is reduced, and the fiber bundle is not easily branched, which hinders the rapid self-assembly of the charged fiber bundle under the electrostatic field.

Comparative Example 4

A preparation method of nanofiber material, the specific steps are as follows:

(1) First, add MIL-101 (Cr) into N,N-dimethylformamide, ultrasonically disperse it for 3 hours, then add polyacrylonitrile to the above dispersion, and continuously stir it with a magnetic stirring device for 12 hours at room temperature to obtain Uniform and stable mixed solution, in which polyacrylonitrile accounts for 5% by mass of the mixed solution, MIL-101(Cr) accounts for 20% by mass of the mixed solution, the viscosity of the mixed solution is 30mPa·s, and the conductivity is 146.4 μS/cm;

(2) Use aluminum foil as the receiving substrate;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 12kV, the perfusion speed was 1mL/h, the distance between the spinneret and the receiving substrate was 15cm, the ambient temperature was 24±1°C, and the ambient relative humidity was 46 ±3% to obtain nanofibrous material.

The final nanofiber material is macroscopically a two-dimensional fiber membrane with a thickness of only micrometers (130 μm). Microscopically, the fibers are randomly oriented and stacked, and the single fibers are beaded and rough and porous. In the field of water conduction and dehumidification, the moisture permeability is 3.6kg/m ² /d, and it does not have unidirectional moisture conduction performance.

Comparing Example 1 with Comparative Example 4, it can be seen that when the receiving substrate is a conductive material, it is difficult to form a honeycomb-like structure, because the use of aluminum foil as a conductive substrate will cause the charges on the initially deposited charged fibers to be removed. If it is guided away, sufficient electrostatic repulsion cannot be generated with the subsequently deposited charged fibers, and it is difficult to branch the fiber bundle, that is, the self-assembly of the honeycomb structure is difficult to occur.

Comparative Example 5

A preparation method of nanofiber material, the specific steps are as follows:

(1) First, add MIL-101 (Cr) into N,N-dimethylformamide, ultrasonically disperse it for 3 hours, then add polyacrylonitrile to the above dispersion, and continuously stir it with a magnetic stirring device for 12 hours at room temperature to obtain Uniform and stable mixed solution, in which polyacrylonitrile accounts for 5% by mass of the mixed solution, MIL-101(Cr) accounts for 20% by mass of the mixed solution, the viscosity of the mixed solution is 30mPa·s, and the conductivity is 146.4 μS/cm;

(2) drying the non-woven fabric after placing it in deionized water for 3 minutes, the deionized water can be used as a conductor to eliminate static electricity, remove the residual charge on the surface of the non-woven fabric, and use the non-woven fabric after the deionization treatment as a receiving substrate;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 8kV, the perfusion speed was 5mL/h, the distance between the spinneret and the receiving substrate was 23cm, the ambient temperature was 24±1°C, and the ambient relative humidity was 65 ±3% to obtain nanofibrous material.

The final nanofiber material is macroscopically a two-dimensional fiber membrane with a thickness of only micrometers (150 μm). Microscopically, the fibers are randomly oriented and stacked, and the single fibers are beaded and rough and porous. In the application of water conduction and dehumidification, the moisture permeability is 3.1kg/m ² /d, and it does not have unidirectional moisture conduction performance.

Comparing Example 1 with Comparative Example 5, it can be seen that when the process parameters of electrospinning exceed the set range (voltage 10～40kV, perfusion speed 0.5～4mL/h, the spinneret is 6～20cm away from the receiving substrate, When the relative humidity of the environment is 30-60%), it is difficult to form a honeycomb-like structure. This is because the change of the electrospinning process parameters changes the electric field strength, which in turn affects the surface charge density of the charged fiber bundle, thereby affecting the fibers deposited on the substrate. The electrostatic repulsion between them ultimately affects the size of the honeycomb pore size (which also determines the apparent degree of the honeycomb structure). If the voltage is too low, the droplets cannot be split to form fine fibers, and the electric field strength at low voltage is low, the surface charge density of the fibers is reduced, the electrostatic repulsion between the fiber bundles deposited on the substrate is reduced, and the branching effect between fibers is weakened, resulting in The pore size of the honeycomb-like structure decreases and even tends to be unpatterned. Similarly, the increase of the spinning distance reduces the electric field strength, the charge density of the fibers, the electrostatic repulsion between the fibers deposited on the substrate, and the branching effect between the fibers. , resulting in a reduction in the pore size of the honeycomb-like structure or even no patterning; if the humidity is too high, the corona discharge is enhanced to dissipate the charge, resulting in a decrease in the surface charge density of the fiber, thereby reducing the electrostatic repulsion between the fibers, and it is difficult to compete with the surface tension. Induces the formation of honeycomb-like structures by self-assembly.

Comparative Example 6

A preparation method of nanofiber material is basically the same as Example 1, except that the mixed solution does not contain MIL-101(Cr), the mass percentage of polyacrylonitrile in the solution is 5%, and the solution viscosity is 26 mPa·s, The electrical conductivity was 48.8 μS/cm, the voltage was 25 kV, the perfusion rate was 0.2 mL/h, and the ambient relative humidity was 23±3%.

Comparing Example 1 with Comparative Example 6, it can be seen that the mixed solution of Comparative Example 6 does not contain metal-organic frameworks, and the conductivity of the solution is significantly reduced, but the electric field strength increases due to the increase in voltage, and the decrease in relative humidity leads to corona. The decrease of the discharge makes it difficult to dissipate the charge, and the surface charge density of the fiber can still increase, so that the electrostatic repulsion between the fibers deposited on the substrate increases, which competes with the surface tension and induces the self-assembly of the honeycomb-like structure. That is to say, if the spinning solution without metal-organic framework is to form a honeycomb-like nanofiber material, it is necessary to increase the voltage and strictly control the environmental humidity. Temperature and humidity control devices, reducing the ambient humidity to a very low level will consume a lot of energy; at the same time, due to changes in voltage and humidity, the perfusion speed also needs to be reduced accordingly, and the extremely low perfusion speed significantly reduces the output of electrospun fibers. Therefore, the honeycomb-like structures prepared from pure polymers are complicated to operate, require strict spinning conditions, and are difficult to achieve fine control of the structure. In addition, in terms of structure and performance, although the nanofiber material prepared in Comparative Example 6 has a honeycomb-like structure, the single-fiber non-porous fiber has a specific surface area of only 6m ² /g, and the moisture absorption and quick-drying performance cannot reach the index of Example 1.

Example 2

A preparation method of a honeycomb structure nanofiber material with high specific surface area, the specific steps are as follows:

(1) First, MIL-101(Cr) _-NH2 was added to N,N-dimethylformamide, ultrasonically dispersed for 4 h, then polyacrylonitrile was added to the above dispersion, and it was continuously stirred with a magnetic stirring device at room temperature 14h, a uniform and stable mixed solution was obtained, in which the mass percentage of polyacrylonitrile in the mixed solution was 8%, the mass percentage of MIL-101(Cr)-NH ₂ in the mixed solution was 24%, and the viscosity of the mixed solution was 53mPa· s, the conductivity is 256.4 μS/cm;

(2) drying the non-woven fabric after 1min in isopropanol, isopropanol can be used as a conductor to eliminate static electricity, remove the residual charge on the surface of the non-woven fabric, and use the non-woven fabric after the de-charge treatment as a receiving substrate;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 20kV, the perfusion speed was 1.2mL/h, the distance between the spinneret and the receiving substrate was 15cm, the ambient temperature was 24±1°C, and the ambient relative humidity was 46±3%, and the honeycomb-like structure nanofiber material was obtained.

The finally obtained high specific surface area honeycomb structure nanofiber material has a certain thickness, a microscopic three-dimensional honeycomb-shaped connected channel structure, the channel is a conical straight channel, the large end of the channel is far away from the substrate, the small end of the channel is close to the substrate, and the large end of the channel The pore diameter is 75±5μm, the small end diameter of the channel is 20±5μm, the single fiber is beaded and rough and porous; the thickness of the high specific surface area honeycomb structure nanofiber material is 1.5mm, the specific surface area is 780m ² /g, and the porosity is 68%, the one-way moisture index is 1556%, the moisture permeability is 12.1kg/m ² /d, and the moisture absorption and quick drying effect is good.

Example 3

A preparation method of a honeycomb structure nanofiber material with high specific surface area, the specific steps are as follows:

(1) First add MIL-101(Cr) _-NH2 into deionized water, ultrasonically disperse for 3h, then add polyvinyl alcohol to the above dispersion, stir continuously with a magnetic stirring device for 12h at room temperature to obtain uniform and stable mixing Among them, the mass percentage of polyvinyl alcohol in the mixed solution is 6%, the mass percentage of MIL-101(Cr)-NH ₂ in the mixed solution is 24%, the viscosity of the mixed solution is 43mPa·s, and the conductivity is 5079μS/ cm;

(2) Put the electrospinning fiber membrane in deionized water for 2 minutes and then dry it. The deionized water can be used as a conductor to eliminate static electricity, remove the residual charge on the surface of the electrospun fiber membrane, and use the electrospun fiber membrane after deionization treatment as the receiving substrate. ;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 18kV, the perfusion speed was 1mL/h, the distance between the spinneret and the receiving substrate was 15cm, the ambient temperature was 24±1°C, and the ambient relative humidity was 46 ±3% to obtain a honeycomb-like nanofiber material.

The finally obtained high specific surface area honeycomb structure nanofiber material has a certain thickness, a microscopic three-dimensional honeycomb-shaped connected channel structure, the channel is a conical straight channel, the large end of the channel is far away from the substrate, the small end of the channel is close to the substrate, and the large end of the channel The pore diameter is 45±5μm, the small end diameter of the channel is 10±5μm, the single fiber is beaded and rough and porous; the thickness of the honeycomb-like nanofiber material with high specific surface area is 1.3mm, the specific surface area is 800m ² /g, and the porosity is 84%, the one-way moisture index is 1487%, the moisture permeability is 11.3kg/m ² /d, and the moisture absorption and quick drying effect is good.

Example 4

A preparation method of a honeycomb structure nanofiber material with high specific surface area, the specific steps are as follows:

(1) First, add MIL-100 (Fe) into a mixed solvent of acetone and dimethyl sulfoxide, the mass ratio of the mixed solvent is 3:2, ultrasonically disperse for 2 hours, then add cellulose acetate to the above dispersion liquid, at room temperature The magnetic stirring device was used for continuous stirring for 14 hours to obtain a uniform and stable mixed solution, wherein the mass percentage of cellulose acetate in the mixed solution was 8%, and the mass percentage of MIL-100(Fe) in the mixed solution was 24%. The viscosity is 85mPa·s, and the conductivity is 4540μS/cm;

(2) Put the electrospinning fiber membrane in isopropanol for 1 min and then dry it. Isopropanol can be used as a conductor to eliminate static electricity, remove the residual charge on the surface of the electrospun fiber membrane, and use the electrospun fiber membrane after de-charge treatment as the receiving base. material;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 25kV, the perfusion speed was 1.5mL/h, the distance between the spinneret and the receiving substrate was 15cm, the ambient temperature was 24±1°C, and the ambient relative humidity was 46±3%, and the honeycomb-like structure nanofiber material was obtained.

The finally obtained high specific surface area honeycomb structure nanofiber material has a certain thickness, a microscopic three-dimensional honeycomb-shaped connected channel structure, the channel is a conical straight channel, the large end of the channel is far away from the substrate, the small end of the channel is close to the substrate, and the large end of the channel The pore diameter is 95±5μm, the small end diameter of the channel is 25±5μm, the single fiber is beaded and rough and porous; the thickness of the honeycomb-like nanofiber material with high specific surface area is 2mm, the specific surface area is 710m ² /g, and the porosity is 80 %, the one-way moisture index is 1573%, the moisture permeability is 11.5kg/m ² /d, and the moisture absorption and quick drying effect is good.

Example 5

A preparation method of a honeycomb structure nanofiber material with high specific surface area, the specific steps are as follows:

(1) First, add HKUST-1 to N,N-dimethylformamide, ultrasonically disperse it for 3 hours, then add polyacrylonitrile to the above dispersion, and continuously stir it with a magnetic stirring device for 12 hours at room temperature to obtain a uniform and stable Mixed liquid, wherein the mass percentage of polyacrylonitrile in the mixed liquid is 6%, the mass percentage of HKUST-1 in the mixed liquid is 24%, the viscosity of the mixed liquid is 37mPa·s, and the conductivity is 163.2μS/cm;

(2) Place the non-woven fabric in a mixed solvent of deionized water and isopropanol, the mass ratio of the mixed solvent is 1:1, soak for 2 minutes and then dry, and the mixed solvent of deionized water and isopropanol can be used as a conductor to eliminate Static electricity, remove the residual charge on the surface of the non-woven fabric, and use the non-woven fabric after de-charge treatment as the receiving substrate;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 18kV, the perfusion speed was 0.8mL/h, the distance between the spinneret and the receiving substrate was 20cm, the ambient temperature was 24±1°C, and the ambient relative humidity was 46±3%, and the honeycomb-like structure nanofiber material was obtained.

The finally obtained high specific surface area honeycomb structure nanofiber material has a certain thickness, a microscopic three-dimensional honeycomb-shaped connected channel structure, the channel is a conical straight channel, the large end of the channel is far away from the substrate, the small end of the channel is close to the substrate, and the large end of the channel The pore diameter is 25±5μm, the small end diameter of the channel is 6±5μm, the single fiber is beaded and rough and porous; the thickness of the high specific surface area honeycomb structure nanofiber material is 0.9mm, the specific surface area is 910m ² /g, and the porosity is 78%, the one-way moisture index is 1314%, the moisture permeability is 10.5kg/m ² /d, and the moisture absorption and quick drying effect is good.

Example 6

A preparation method of a honeycomb structure nanofiber material with high specific surface area, the specific steps are as follows:

(1) First, add MIL-101(Cr) into N,N-dimethylacetamide, ultrasonically disperse it for 2 hours, then add polyurethane to the above dispersion liquid, and continuously stir it with a magnetic stirring device for 12 hours at room temperature to obtain a uniform and stable The mixed solution, wherein the mass percentage of polyurethane in the mixed solution is 3%, the mass percentage of MIL-101(Cr) in the mixed solution is 15%, the viscosity of the mixed solution is 148mPa·s, and the conductivity is 150.5μS/cm;

(2) The electrospinning fiber membrane is placed in a mixed solvent of deionized water and isopropanol, the mass ratio of the mixed solvent is 2:1, soaked for 2 minutes and then dried, and the mixed solvent of deionized water and isopropanol can be used as a conductor Eliminate static electricity, remove the residual charge on the surface of the electrospinning fiber membrane, and use the electrospun fiber membrane after de-charging treatment as the receiving substrate;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 25kV, the perfusion speed was 0.6mL/h, the distance between the spinneret and the receiving substrate was 18cm, the ambient temperature was 24±1°C, and the ambient relative humidity was 33±3%, the honeycomb-like structure nanofiber material was obtained.

The finally obtained high specific surface area honeycomb structure nanofiber material has a certain thickness, a microscopic three-dimensional honeycomb-shaped connected channel structure, the channel is a conical straight channel, the large end of the channel is far away from the substrate, the small end of the channel is close to the substrate, and the large end of the channel The pore size is 95±5μm, the pore diameter at the small end of the channel is 24±5μm, the single fiber is beaded and rough and porous; the thickness of the honeycomb-like nanofiber material with high specific surface area is 1mm, the specific surface area is as high as 850m ² /g, and the porosity is 85 %, the unidirectional moisture index is 1358%, the moisture permeability is 14.5kg/m ² /d, and the moisture absorption and quick drying effect is good.

Example 7

A preparation method of a honeycomb structure nanofiber material with high specific surface area, the specific steps are as follows:

(1) First, add CAU-1 (Al) into the mixed solvent of N,N-dimethylformamide and chloroform, the mass ratio of N,N-dimethylformamide and chloroform is 1:1 , ultrasonically dispersed for 4h, then polylactic acid was added to the above dispersion liquid, and the magnetic stirring device was continuously stirred for 12h at room temperature to obtain a uniform and stable mixed liquid, wherein the mass percentage of polylactic acid in the mixed liquid was 4%, CAU-1 (Al) accounts for 24% by mass of the mixed solution, the viscosity of the mixed solution is 236 mPa·s, and the conductivity is 443 μS/cm;

(2) The non-woven fabric is placed in a mixed solvent of deionized water and isopropanol, the mass ratio of the mixed solvent is 1:2, and dried after soaking for 2 minutes. The mixed solvent of deionized water and isopropanol can be used as a conductor to eliminate Static electricity, remove the residual charge on the surface of the non-woven fabric, and use the non-woven fabric after de-charge treatment as the receiving substrate;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 40kV, the perfusion speed was 0.6mL/h, the distance between the spinneret and the receiving substrate was 20cm, the ambient temperature was 25±1°C, and the ambient relative humidity was 37±3%, and the honeycomb-like nanofiber material was obtained.

The finally obtained high specific surface area honeycomb structure nanofiber material has a certain thickness, a microscopic three-dimensional honeycomb-shaped connected channel structure, the channel is a conical straight channel, the large end of the channel is far away from the substrate, the small end of the channel is close to the substrate, and the large end of the channel The pore diameter is 85±5μm, the small end diameter of the channel is 20±5μm, the single fiber is beaded and rough and porous; the thickness of the high specific surface area honeycomb structure nanofiber material is 1.5mm, the specific surface area is 750m ² /g, and the porosity is 87%, the one-way moisture index is 1554%, the moisture permeability is 13.6kg/m ² /d, and the moisture absorption and quick drying effect is good.

Example 8

A preparation method of a honeycomb structure nanofiber material with high specific surface area, the specific steps are as follows:

(1) at first add HKUST-1 to the mixed solvent of dimethyl sulfoxide and N,N-dimethylacetamide, the mass ratio of dimethylsulfoxide and N,N-dimethylacetamide is 1: 1. Ultrasonic dispersion for 4 hours, then adding polysulfone and polyurethane with a mass ratio of 1:1 to the above dispersion liquid, stirring continuously for 16 hours with a magnetic stirring device at room temperature, to obtain a uniform and stable mixed liquid, wherein the polymer accounts for the mixed liquid. The mass percentage of HKUST-1 is 5%, the mass percentage of HKUST-1 in the mixture is 30%, the viscosity of the mixture is 240mPa·s, and the conductivity is 130.2μS/cm;

(2) Put the electrospinning fiber membrane in deionized water for 1 min and then dry it. The deionized water can be used as a conductor to eliminate static electricity, remove the residual charge on the surface of the electrospun fiber membrane, and use the electrospun fiber membrane after deionization treatment as the receiving substrate. ;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 40kV, the perfusion speed was 2mL/h, the distance between the spinneret and the receiving substrate was 20cm, the ambient temperature was 25±1°C, and the ambient relative humidity was 57 ±3% to obtain a honeycomb-like nanofiber material.

The finally obtained high specific surface area honeycomb structure nanofiber material has a certain thickness, a microscopic three-dimensional honeycomb-shaped connected channel structure, the channel is a conical straight channel, the large end of the channel is far away from the substrate, the small end of the channel is close to the substrate, and the large end of the channel The pore diameter is 85±5μm, the small end diameter of the channel is 20±5μm, the single fiber is beaded and rough and porous; the thickness of the high specific surface area honeycomb structure nanofiber material is 1mm, the specific surface area is 900m ² /g, and the porosity is 80 %, the one-way moisture index is 1421%, the moisture permeability is 14.3kg/m ² /d, and the moisture absorption and quick drying effect is good.

Example 9

A preparation method of a honeycomb structure nanofiber material with high specific surface area, the specific steps are as follows:

(1) First, add MIL-100(Fe) into the mixed solvent of chloroform and N,N-dimethylformamide, the mass ratio of chloroform and N,N-dimethylformamide is 4:1, and ultrasonically disperse for 3h , and then polycaprolactone was added to the above dispersion liquid, and the magnetic stirring device was continuously stirred for 12 hours at room temperature to obtain a uniform and stable mixed liquid, wherein the mass percentage of polycaprolactone in the mixed liquid was 5%, and MIL-100 (Fe) accounts for 25% of the mass of the mixture, the viscosity of the mixture is 48mPa·s, and the conductivity is 1966μS/cm;

(2) drying the non-woven fabric in isopropanol for 2 minutes, isopropanol can be used as a conductor to eliminate static electricity, remove the residual charge on the surface of the non-woven fabric, and use the non-woven fabric after the de-charge treatment as a receiving substrate;

(3) Electrospinning was carried out using the mixed solution obtained above, the voltage was 40kV, the perfusion speed was 3mL/h, the distance between the spinneret and the receiving substrate was 20cm, the ambient temperature was 25±1°C, and the ambient relative humidity was 57 ±3% to obtain a honeycomb-like nanofiber material.

The finally obtained high specific surface area honeycomb structure nanofiber material has a certain thickness, a microscopic three-dimensional honeycomb-shaped connected channel structure, the channel is a conical straight channel, the large end of the channel is far away from the substrate, the small end of the channel is close to the substrate, and the large end of the channel The pore diameter is 95±5μm, the diameter of the small end of the channel is 20±5μm, the single fiber is beaded and rough and porous; the thickness of the high specific surface area honeycomb structure nanofiber material is 2mm, the specific surface area is 740m ² /g, and the porosity is 83 %, the one-way moisture index is 1693%, the moisture permeability is 12.8kg/m ² /d, and the moisture absorption and quick drying effect is good.

Claims (10)

1. The preparation method of the nano-fiber material with the high specific surface area honeycomb-like structure is characterized in that polymer solution dispersed with a nano-scale metal-organic framework is subjected to electrostatic spinning, and an insulating material subjected to charge elimination treatment is used as a receiving base material to prepare the nano-fiber material with the high specific surface area honeycomb-like structure;

the polymer solution dispersed with the nanoscale metal-organic framework has the viscosity ranging from 1 to 500mPa · S and the conductivity ranging from 100 to 10000 muS/cm;

the technological parameters of electrostatic spinning comprise: the voltage is 10-40 kV, the filling speed is 0.5-4 mL/h, the distance between a spinning head and a receiving base material is 6-20 cm, and the relative humidity of the environment is 30-60%;

the insulating material is non-woven fabric or electrostatic spinning fiber membrane;

the method for eliminating charges comprises the following steps: and (3) placing the insulating material in a charge eliminating solvent for a period of time and then drying.

2. A shank as set forth in claim 1The preparation method of the nano-fiber material with the specific surface area and the honeycomb-like structure is characterized in that the metal-organic framework is MIL-101(Cr) or MIL-101(Cr) -NH₂、MIL-100(Fe)、HKUST-1、CAU-1(Al)、CAU-23(Al)、UiO-66、UiO-66-NH₂KAUST-8, MOF-801, MOF-804, MOF-841, DUT-67(Zr), DUT-51(Zr), DUT-53(Zr), MOF-74(Mg), and MOF-74 (Ni).

3. The method for preparing the nano-fiber material with the high specific surface area and the honeycomb-like structure according to claim 2, wherein the polymer is one or more of polyacrylonitrile, polyurethane, cellulose acetate, polyvinyl alcohol, polylactic acid, polysulfone, polyethylene oxide, polycaprolactone, polyamide 6, polyamide 66, polyimide, polyethersulfone, polyethylene terephthalate, polystyrene sulfonic acid sodium salt, polyacrylate resin, polyethylene glycol, polyvinylpyrrolidone, thermoplastic polyurethane elastomer, chitosan, cellulose derivative and ion exchange resin.

4. The method for preparing a nano-fiber material with a high specific surface area and a honeycomb-like structure according to claim 3, wherein the solvent in the polymer solution is one or more of N, N-dimethylformamide, N-dimethylacetamide, chloroform, tetrahydrofuran, N-methylpyrrolidone, chloroform, methanol, ethanol, isopropanol, deionized water, acetone, dichloromethane, formic acid, acetic acid, dimethyl sulfoxide, diethyl ether, toluene, trichloroacetic acid and trifluoroacetic acid.

5. The method for preparing the nano fiber material with the high specific surface area honeycomb-like structure according to claim 4, wherein the polymer solution dispersed with the nano metal-organic framework is prepared by the following steps: adding a metal-organic framework into a solvent, performing ultrasonic dispersion for 1-4 hours, adding a polymer, and continuously stirring for 2-24 hours at room temperature or 50-90 ℃ by using a magnetic stirring device.

6. The method for preparing the nano-fiber material with the high specific surface area and the honeycomb-like structure as claimed in claim 4, wherein the polymer solution dispersed with the nano-scale metal-organic framework comprises 3-15% by mass of the polymer and 10-30% by mass of the metal-organic framework.

7. The method for preparing a nano fiber material with a high specific surface area and a honeycomb-like structure according to claim 1, wherein the electrostatic spinning process parameters further comprise: the ambient temperature is 23-26 ℃.

8. The method for preparing the nano fiber material with the high specific surface area and the honeycomb-like structure according to claim 1, wherein the charge eliminating solvent is deionized water and/or isopropanol; the period of time is 1-3 min.

9. The high specific surface area honeycomb-like structure nanofiber material prepared by the preparation method of the high specific surface area honeycomb-like structure nanofiber material according to any one of claims 1 to 8, wherein the high specific surface area honeycomb-like structure nanofiber material has a certain thickness and is microscopically in a three-dimensional honeycomb-like communicated pore channel structure, the pore channels are tapered through pore channels, the large ends of the pore channels are far away from the base material, the small ends of the pore channels are close to the base material, the pore diameter of the large ends of the pore channels is 20-100 μm, the pore diameter of the small ends of the pore channels is 5-25 μm, and single fibers are in a bead-.

10. The high specific surface area honeycomb-like structure nanofiber material as claimed in claim 9, wherein the high specific surface area honeycomb-like structure nanofiber material has a thickness of more than 0.8mm and a specific surface area of more than 600m²The porosity is more than 75 percent, the one-way moisture permeability index is more than 1300 percent, and the moisture permeability is more than 10kg/m²/d。

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