Cellulose-based high-fog-efficiency fiber and method for preparing the same

Abstract

The application discloses cellulose-based high-fog-collection-efficiency fiber and a preparation method thereof, and belongs to the field of fog collection. According to the method, cellulose is activated, and polyvinylpyrrolidone is dissolved in a solvent; the mass ratio of the polyvinylpyrrolidone and the activated cellulose is (5-30):100, so that a spinning solution is obtained; the spinning solution is spun in a first water bath through a one-step wet spinning method, and fibers with a draw ratio of 100%-300% are collected, so that the cellulose-based high-fog-collection-efficiency fiber is obtained. The application solves the problem of selecting a material that is helpful to the improvement of the fog collection efficiency, simplifying the preparation process, reducing the cost, and improving the fog collection efficiency of the fiber. The preparation method is simple, the cost is lower, the cellulose and the PVP are formed into the fog collection fiber through the one-step wet spinning method, and the fog collection efficiency of the fiber is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fog collection, and particularly relates to a cellulose-based high-fog-collection-efficiency fiber and a preparation method thereof. BACKGROUND

[0002] With the continuous exploration of natural resources, inspired by the condensation of fog in nature, the method of converting this abundant but underutilized water resource into actually usable fresh water has attracted widespread attention. In this context, the use of fog collection fibers to collect fog as an innovative passive water collection method is widely used in the field of fog collection.

[0003] Current fog collection fibers mainly rely on external assistance (such as electricity, magnetic field, etc.) or other complex infrastructure to improve the fog collection efficiency. These methods can improve the efficiency to some extent, but at the same time, there are also deficiencies. For example, the fog collection fiber assisted by electricity has a significantly reduced service life in a long-term high-density humid air environment, and is prone to unstable performance due to the dependence of the performance of the fog collection material on electricity. Although the fog collection material requiring complex infrastructure is less prone to unstable performance in a high-humidity environment, the additional facility construction and maintenance costs significantly increase the cost. Although the above methods have played an important role in the field of fog collection, traditional fog collectors still have difficulty in balancing low cost and high efficiency, and the breakthrough lies in its simple and efficient characteristics, so it is crucial to find a method that can effectively collect moisture by only using the temperature difference and humidity change in nature. In recent years, biological materials have attracted widespread attention due to their wide range of sources and renewable characteristics. Among them, cellulose, as the oldest and most abundant natural polymer on earth, provides a natural high-efficiency hydrophilic domain with its abundant hydroxyl groups on the molecular backbone of β-D-glucopyranose ring. It is a renewable material with strong moisture absorption and is the best natural raw material for preparing environmentally friendly and biocompatible materials. Therefore, cellulose-based materials have great potential in the preparation of fog collection fibers.

[0004] The cellulose-based biomass set fog fiber has the following advantages: the excellent biocompatibility and degradable characteristics of cellulose itself and the strong hygroscopicity, which are beneficial to the application to the field of advanced functional fibers. In recent years, bionics has been borrowed and applied a lot. It is mentioned in the Chinese patent with the application number CN201811151930.1 and the name of “Preparation method of spider silk fiber structure with directional hydrophobicity” that the use of the special structure of the spider silk fiber and the surface energy difference between the spindle node on the fiber surface can cause Laplace force to promote the movement and aggregation of water droplets. However, due to the limitation of the properties of the used substrate, the improvement of the fiber set fog efficiency is not obvious, and the complex preparation method increases the technical implementation difficulty and the preparation cost, so that the set fog efficiency of the fiber is also limited. Therefore, the problem of selecting a material that can help improve the set fog efficiency, simplifying the preparation process, and reducing the cost while improving the set fog efficiency of the fiber is still an urgent problem to be solved at present. SUMMARY

[0005] In view of the problems in the prior art, the present application provides a cellulose-based high set fog efficiency fiber and a preparation method thereof to solve the problem of selecting a material that can help improve the set fog efficiency, simplifying the preparation process, and reducing the cost while improving the set fog efficiency of the fiber. The preparation method is simple and has a lower cost. The cellulose and PVP are formed into a set fog fiber through a one-step wet spinning method, and the set fog efficiency of the fiber is improved.

[0006] The present application is realized by the following technical solutions:

[0007] A preparation method of a cellulose-based high set fog efficiency fiber, comprising the following steps:

[0008] S1, after activating the cellulose, the cellulose and polyvinylpyrrolidone are dissolved in a solvent, the mass ratio of polyvinylpyrrolidone to activated cellulose is (5-30):100, to obtain a spinning solution;

[0009] S2, the spinning solution is spun in a first water bath through a one-step wet spinning method, and fibers with a draw ratio of 100%-300% are collected to obtain a cellulose-based high set fog efficiency fiber.

[0010] The present application is further improved in that:

[0011] S1, the cellulose is activated according to the following process:

[0012] According to the mass ratio of 1: (10-20), the cellulose is activated in N,N-dimethylacetamide at 60-120℃ for 60-120min, and then dried to complete the activation of the cellulose.

[0013] The solvent in S1 is a solution of LiCl in N,N dimethylacetamide, and the mass ratio of LiCl to N,N dimethylacetamide is 1:11.

[0014] S1 obtains the spinning solution according to the following process:

[0015] The activated cellulose is first placed in the solution of LiCl in N,N dimethylacetamide, and the mass ratio of the activated cellulose to the solution of LiCl in N,N dimethylacetamide is 1:24, and then polyvinylpyrrolidone is added after stirring at 55-65 DEG C for 5.5-6.5 h, and the stirring is continued for 12-24 h to obtain the spinning solution.

[0016] The flow rate of the spinning solution in S2 is 2-20 ml / h during spinning.

[0017] S3 is also included:

[0018] In S3, the cellulose-based high-fog-efficiency fiber is immersed in the mixed solution of the activated cellulose and PVDF in S1, and the mass ratio of the cellulose to PVDF is 3:7, and then phase inversion is carried out in a second water bath, and then room temperature drying is carried out, and then spindle knots are formed on the surface of the cellulose-based high-fog-efficiency fiber to obtain cellulose-based high-fog-efficiency fiber with a biomimetic spider silk structure.

[0019] In the mixed solution in S3, the total mass percentage of the cellulose and PVDF is 2%-10%, and the solvent is N,N dimethylacetamide.

[0020] The rate during the drawing in S3 is 100-200 mm / min.

[0021] The room temperature drying time in S3 is 45-50 h.

[0022] A cellulose-based high-fog-efficiency fiber obtained by the preparation method of the cellulose-based high-fog-efficiency fiber according to any one of the above.

[0023] Compared with the prior art, the present application has the following beneficial technical effects:

[0024] The application discloses a preparation method of cellulose-based high-fog-efficiency fiber. After activation of cellulose, the degree of intermolecular hydrogen bond entanglement is reduced, the solubility of cellulose in a solvent is further improved, and then the cellulose is dissolved to prepare a spinning solution together with PVP. The cellulose-based high-fog-efficiency fiber is formed by controlling a draw ratio. If the PVP content is less than 5% of the activated cellulose, the amount of PVP precipitated is too small, the fiber surface cannot form a clear groove structure, the fiber has no obvious effect on improving the fog collection efficiency, when the PVP content is 10%, the groove structure on the fiber surface is the most uniform, and the fog collection efficiency reaches the maximum value, when the PVP content is further increased, the fiber surface structure becomes disordered, the fog collection efficiency also decreases, and when the PVP content is more than 30%, the fiber surface structure is disordered and the fiber is prone to agglomeration, the relative stable structure for collecting fog cannot be formed, and the fog collection efficiency decreases. Therefore, by controlling the mass ratio of polyvinylpyrrolidone and the activated cellulose to be (5-30): 100, the fiber with the groove structure on the surface can be constructed, and the fog collection efficiency is obviously improved. The raw material of the application is biomass-based cellulose natural material, which is rich in content, low in price, has excellent hydrophilic properties and degradability, and has good biocompatibility and degradability. The cellulose provides a more sustainable choice for the field of fog collection. The cellulose and PVP are formed into the fog collection fiber by one-step wet spinning, the preparation method is simple, the cost is lower, the operability is strong, the production efficiency is high, the method is suitable for large-scale production and application, and the cellulose and PVP are formed into the fog collection fiber by one-step wet spinning, the preparation method is simple, the cost is lower, the operability is strong, the production efficiency is high, the method is suitable for large-scale production and application.

[0025] Further, the activated cellulose and PVDF mixed solution is immersed on the surface of the cellulose-based high-efficiency mist collecting fiber to form a spindle knot by phase inversion in the second water bath and room temperature drying. The phase inversion in the second water bath can convert the immersion coating liquid on the fiber surface from liquid to solid, the driving force generated by the certain curvature gradient of the spindle knot has a beneficial effect on the improvement of the mist collecting efficiency of the fiber, and the certain hydrophilic and hydrophobic properties of the immersion coating liquid can produce a wettability gradient from the fiber surface to the spindle knot, which has a positive effect on the mist collecting efficiency of the fiber. The cellulose-based high-efficiency mist collecting fiber with the obtained biomimetic spider silk structure is placed on a support in a 25℃ environment. Due to the uniform and consistent groove structure on the fiber surface, when the mist flows through, the existence of the groove structure on the fiber surface increases the effective contact area between the fiber and the mist, and at the same time, a large amount of capillary force can be provided to accelerate the capture of the mist, and a small droplet is quickly generated on the fiber surface. At the same time, the introduction of the spindle knot further improves the water collecting capacity and droplet suspension capacity of the fiber. After the liquid droplet is captured on the fiber surface, it is transported along the groove structure to the spindle knot, and then grows in situ on the spindle knot. When the critical droplet volume is reached, it falls and collects under the action of gravity. During the transportation of the liquid droplet, a liquid film is formed between adjacent groove structures due to the existence of the groove structure, which can provide continuous internal driving force to quickly complete the entire transportation process, thereby improving the mist collecting performance and transportation performance of the fiber. The mist collecting efficiency can reach 180.62g / (cm²·h), which is a simple and efficient solution and has great potential in the field of mist collecting materials. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a sample physical map of the cellulose-based high-efficiency mist collecting fiber (PVP silk) prepared in embodiment 3 of the present application.

[0027] Figure 2a is a scanning electron microscope image of the cellulose silk (denoted as C) obtained in embodiment 1 of the present application.

[0028] Figure 2b is a scanning electron microscope image of the cellulose-based high-efficiency mist collecting fiber (PVP silk, denoted as P) obtained in embodiment 3 of the present application.

[0029] Figure 3a is a comparison chart of the mist collecting efficiency of the cellulose silk (denoted as C) obtained in embodiment 1 of the present application and the cellulose-based high-efficiency mist collecting fiber (denoted as P) obtained in embodiment 3.

[0030] Figure 3b is a comparison chart of the mist collecting efficiency of the biomimetic spider silk cellulose silk (denoted as CF) after the construction of the spindle knot structure in embodiment 7 of the present application and the PVP silk (denoted as PCF).

[0031] Figure 4is the fiber (PCF) fog collecting process diagram of the biomimetic spider silk high-efficiency fog collecting fiber prepared by embodiment 7 of the present application. DETAILED DESCRIPTION

[0032] The technical solutions of the present application will be described clearly and completely below in combination with specific drawings, process steps, implementation conditions and materials. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0033] The present application is a preparation method of cellulose-based high fog collection efficiency fiber, comprising the following steps:

[0034] 1) After the cellulose is activated (dried after activation in the activator, the mass ratio of the activator to the cellulose is 10-20:1), the degree of intermolecular hydrogen bonding of the cellulose is reduced, and the solubility of the cellulose in the solvent is further improved.

[0035] The activator of the activation process is N,N dimethylacetamide (DMAc). The activation temperature is 60-120℃, and the activation time is 60-120 min.

[0036] Specifically, the solvent is an N,N dimethylacetamide solution of LiCl, the mass ratio of LiCl to N,N dimethylacetamide is 1:11, the activated cellulose is first placed in the solvent, the mass ratio of the activated cellulose to the solvent is 1:24, 60℃ water bath heating and stirring for 6h, then PVP is added and continues to stir for 12-24h, to obtain a uniform spinning solution.

[0037] 3) The spinning solution is spun by a one-step wet spinning method in the first water bath (the coagulation bath is water), the flow rate of the spinning solution is 2-20ml / h, the conversion from liquid phase to solid phase is completed during the spinning process, and the fiber with a draw ratio of 100%-300% is collected to obtain the cellulose-based high-efficiency fog collecting fiber (the groove structure is successfully constructed on the surface of the fiber).

[0038] 4) The wet-spun fiber is immersed in a mixed solution of activated cellulose (hereinafter referred to as cellulose) and PVDF (the solvent is N,N dimethylacetamide, the mass ratio of cellulose to PVDF is 3:7, and the total mass percentage of cellulose and PVDF is 2wt%-10wt%), and then pulled up at a pulling rate of 100-200mm / min, to form a certain hydrophobic spindle knot on the surface of the fiber by means of Rayleigh instability principle, to obtain the cellulose-based biomimetic spider silk high-efficiency fog collecting fiber.

[0039] 5) The fiber obtained in S4 is then immersed in a second water bath (the coagulation bath is water) for a second phase inversion (the dip-coating liquid on the surface of the fiber is changed from liquid to solid, reducing the subsequent drying time), and the fiber is dried at room temperature for 45-50 hours to obtain the final-state cellulose-based biomimetic spider silk high-efficiency fog collection fiber (the fiber with a groove structure on the surface successfully introduces a spindle knot structure).

[0040] The PVP addition amount is 10% of the activated cellulose, the groove structure on the surface of the fiber is the most uniform, and the fog collection efficiency also reaches a maximum value. Further improvement starts to disorder the surface structure of the fiber, and the fog collection efficiency also decreases. This is mainly due to the excessive precipitation of PVP, which is prone to agglomeration and causes obvious damage to the surface structure of the fiber.

[0041] By dip-coating 2wt%, 4wt%, 6wt%, 8wt% and 10wt% cellulose and PVDF mixed liquid on the surface of the fiber to continue forming a spindle knot (biomimetic spider silk structure), the driving force generated by the curvature gradient helps the fiber transmission process, and the certain hydrophilic and hydrophobic properties of the dip-coating liquid will cause a wettability gradient on the fiber surface to the spindle knot. The driving force generated by the wettability gradient is also beneficial to improve the water guiding capacity of the fiber. In addition, the spindle knot surface with certain hydrophobicity can reduce the pinning phenomenon caused by the excessive hydrophilicity of cellulose on the fiber surface, thereby accelerating the falling of the droplets. The size and size of the spindle knot can be controlled by controlling the concentration of the dip-coating liquid and the pulling speed, and the spindle knot size and spacing also increase with the increase of the concentration of the mixed liquid and the pulling speed. By using Rayleigh instability, the curvature of the spindle knot at the junction with the fiber also increases, but when the concentration of the dip-coating liquid exceeds 6wt%, the solution becomes viscous and difficult to fall naturally by gravity. The shape of the spindle knot is not easy to form completely, the curvature gradient of the spindle knot and the fiber surface starts to decrease, and too much dip-coating liquid will remain on the fiber surface, which will fill the groove structure on the fiber surface and cause the spindle knot to be completely shaped.

[0042] Example 1

[0043] Take DMAc 100g, add 10g cellulose, activate at 120℃ for 60min, and dry to obtain activated cellulose.

[0044] Dissolve 0.8g LiCl in 8.8g DMAc, then dissolve 0.4g activated cellulose, stir at 60℃ for 6h, and obtain a uniform spinning solution.

[0045] The spinning solution was injected into a needle diameter of 0.60 mm syringe connected to the wet spinning device. The extrusion speed, coagulation bath distance and take-up speed were kept at 4 mL / h, 0.6 m and 12 cm / s, the coagulation bath was water, the temperature was 35°C, the time was 15 seconds, and the draw ratio was 200%, so as to obtain cellulose fibers (denoted as C). The spinning process was carried out at an ambient temperature of 25°C.

[0046] Example 2

[0047] Take DMAc 100 g, add 10 g of cellulose, activate at 120°C for 60 min, and dry to obtain activated cellulose.

[0048] Dissolve 0.8 g of LiCl in 8.8 g of DMAc, then dissolve 0.4 g of activated cellulose, stir at 60°C for 6 h, then add 0.02 g of PVP and continue stirring for 12 h to obtain a uniform spinning solution.

[0049] The spinning solution was injected into a needle diameter of 0.60 mm syringe connected to the wet spinning device. The extrusion speed, coagulation bath distance and take-up speed were kept at 4 mL / h, 0.6 m and 12 cm / s, the coagulation bath was water, the temperature was 35°C, the time was 15 seconds, and the draw ratio was 200%, so as to obtain cellulose fibers (denoted as C). The spinning process was carried out at an ambient temperature of 25°C.

[0050] Example 3

[0051] Take DMAc 100 g, add 10 g of cellulose, activate at 120°C for 60 min, and dry to obtain activated cellulose.

[0052] Dissolve 0.8 g of LiCl in 8.8 g of DMAc, then dissolve 0.4 g of activated cellulose, stir at 60°C for 6 h, then add 0.02 g of PVP and continue stirring for 12 h to obtain a uniform spinning solution.

[0053] The spinning solution was injected into a needle diameter of 0.60 mm syringe connected to the wet spinning device. The extrusion speed, coagulation bath distance and take-up speed were kept at 4 mL / h, 0.6 m and 12 cm / s, the coagulation bath was water, the temperature was 35°C, the time was 15 seconds, and the draw ratio was 200%, so as to obtain cellulose fibers (denoted as C). The spinning process was carried out at an ambient temperature of 25°C.

[0054] Example 4

[0055] Take DMAc 100 g, add 10 g of cellulose, activate at 120°C for 60 min, and dry to obtain activated cellulose.

[0056] Take 0.8 g LiCl dissolved in 8.8 g DMAc, then dissolve 0.4 g of activated cellulose, stir at 60°C for 6h, then add 0.06 g PVP and continue stirring for 12h to obtain a uniform spinning solution.

[0057] The spinning solution is injected into a needle diameter of 0.60 mm injector, connected to the wet spinning device. The extrusion speed, coagulation bath distance and winding speed are kept at 4 mL / h, 0.6 m and 12 cm / s, the coagulation bath is water, the temperature is 35°C, the time is 15 seconds, and the stretching ratio is 200%. The spinning process is carried out at an ambient temperature of 25°C.

[0058] Example 5

[0059] Take DMAC 100 g, add 10 g cellulose, activate at 120°C for 60 min, and dry to obtain activated cellulose.

[0060] Take 0.8 g LiCl dissolved in 8.8 g DMAc, then dissolve 0.4 g of activated cellulose, stir at 60°C for 6h, then add 0.06 g PVP and continue stirring for 12h to obtain a uniform spinning solution.

[0061] The spinning solution is injected into a needle diameter of 0.60 mm injector, connected to the wet spinning device. The extrusion speed, coagulation bath distance and winding speed are kept at 4 mL / h, 0.6 m and 12 cm / s, the coagulation bath is water, the temperature is 35°C, the time is 15 seconds, and the stretching ratio is 200%. The spinning process is carried out at an ambient temperature of 25°C.

[0062] Then the above obtained fiber is immersed in a 2wt% cellulose and PVDF mixed solution, the pulling rate is 150 mm / min, and after the formation of hydrophobic and hydrophilic characteristics on the surface of the fiber, it enters the second water bath for the second phase inversion (temperature is 40°C, time is 20 seconds), and after drying at room temperature for 48h, cellulose-based biomimetic spider silk high-efficiency fog collecting fiber can be obtained.

[0063] Example 6

[0064] Take DMAC 100 g, add 10 g cellulose, activate at 120°C for 60 min, and dry to obtain activated cellulose.

[0065] Take 0.8 g LiCl dissolved in 8.8 g DMAc, then dissolve 0.4 g of activated cellulose, stir at 60°C for 6h, then add 0.06 g PVP and continue stirring for 12h to obtain a uniform spinning solution.

[0066] The spinning solution was injected into a needle diameter of 0.60 mm syringe connected to the wet spinning device. The extrusion speed, coagulation bath distance and take-up speed were kept at 4 mL / h, 0.6 m and 12 cm / s, the coagulation bath was water, the temperature was 35°C, the time was 15 seconds, and the draw ratio was 200%. The spinning process was carried out at an ambient temperature of 25°C.

[0067] The obtained fiber was immersed in a 4wt% cellulose and PVDF mixed solution again, the pulling rate was 150 mm / min, and after the spindle knot with hydrophilic and hydrophobic properties was formed on the surface of the fiber, it entered the second water bath tank for the second heavy phase transformation (temperature was 40°C, time was 20 seconds), and after drying at room temperature for 48h, the cellulose-based biomimetic spider silk high-efficiency fog collecting fiber was obtained.

[0068] Example 7

[0069] Take 100g of DMAC, add 10g of cellulose, activate at 120°C for 60min, and dry to obtain activated cellulose.

[0070] Dissolve 0.8g of LiCl in 8.8g of DMAc, then dissolve 0.4g of activated cellulose, stir at 60°C for 6h, then add 0.04g of PVP and continue stirring for 12h to obtain a uniform spinning solution.

[0071] The spinning solution was injected into a needle diameter of 0.60 mm syringe connected to the wet spinning device. The extrusion speed, coagulation bath distance and take-up speed were kept at 4 mL / h, 0.6 m and 12 cm / s, the coagulation bath was water, the temperature was 35°C, the time was 15 seconds, and the draw ratio was 200%. The spinning process was carried out at an ambient temperature of 25°C.

[0072] The obtained fiber was immersed in a 4wt% cellulose and PVDF mixed solution again, the pulling rate was 150 mm / min, and after the spindle knot with hydrophilic and hydrophobic properties was formed on the surface of the fiber, it entered the second water bath tank for the second heavy phase transformation (temperature was 40°C, time was 20 seconds), and after drying at room temperature for 48h, the cellulose-based biomimetic spider silk high-efficiency fog collecting fiber was obtained.

[0073] Example 8

[0074] Take 100g of DMAC, add 10g of cellulose, activate at 120°C for 60min, and dry to obtain activated cellulose.

[0075] Take 0.8 g LiCl dissolved in 8.8 g DMAc, then dissolve 0.4 g of activated cellulose, stir at 60°C for 6h, then add 0.04 g PVP and continue stirring for 12h to obtain a uniform spinning solution.

[0076] The spinning solution is injected into a needle diameter of 0.60 mm syringe connected to a wet spinning device. The extrusion speed, coagulation bath distance and winding speed are kept at 4 mL / h, 0.6 m and 12 cm / s, the coagulation bath is water, the temperature is 35°C, the time is 15 seconds, and the stretching ratio is 200%. The spinning process is carried out at an ambient temperature of 25°C.

[0077] Then the above obtained fiber is immersed in a mixed solution of 8wt% cellulose and PVDF, the pulling rate is 150mm / min, and after the formation of spindle knots with hydrophilic and hydrophobic properties on the surface of the fiber, it enters the second water bath for the second phase inversion (temperature is 40°C, time is 20 seconds), and after drying at room temperature for 48h, cellulose-based biomimetic spider silk high-efficiency fog collecting fiber can be obtained.

[0078] As shown in Figure 1 , the prepared high-efficiency fog collecting fiber is collected on the winding roller, and the surface of the prepared fiber is uniform.

[0079] As shown in Figure 2a and Figure 2b are the SEM comparison diagrams of the surface of the cellulose silk (C) prepared in Example 1 and the fog collecting fiber (P) prepared in Example 3, respectively, it can be clearly seen that the fiber surface after adding PVP successfully constructs a uniform groove structure.

[0080] Figure 3a The fog collecting efficiency of the cellulose silk (C) prepared in Example 1 and the cellulose-based high-efficiency fog collecting fiber (P) prepared in Example 3 is shown, and it can be seen from the figure that the fog collecting efficiency of the fiber (P) with a groove structure on the surface is obviously improved, which further verifies the effect of the groove structure on improving the fog collecting performance of the fiber.

[0081] Figure 3b The fog collecting efficiency of the biomimetic spider silk cellulose silk (CF) and PVP silk (PCF) after adding spindle knot structure in Example 7 is shown, and it can be easily obtained from the figure that the introduction of spindle knot can further improve the fog collecting performance of the fiber, and the PCF surface has both groove structure and spindle knot structure, and the fog collecting efficiency of the fiber is best at this time.

[0082] The fiber of Example 7 was placed on a U-shaped support, a commercial humidifier (YC-D205, Beijing Yada Technology Co., Ltd.) was used to generate simulated fog flow, and the fog was aimed at the fiber. The generated fog flow volume was 300 mL / h, the distance between the humidifier and the fiber was kept constant (5 cm), a glass plate was placed directly below the fiber as a collection device to collect the liquid droplets captured by the fiber, and the environmental conditions were controlled throughout the experiment, with the temperature kept at 25±3°C and the relative humidity kept at 50±10%RH. The change in fog collection on the fiber was recorded according to time, Figure 4 The time consumed for a complete water cycle process on the fiber (i.e. the process from the fiber contacting the fog on the surface to start collecting to the first complete liquid droplet falling and collecting) was only 36 s, and the fog collection efficiency could reach 180.62 g / (cm²·h).

Claims

1. A method for producing a cellulose-based high-fog-efficiency fiber, characterized by, The method comprises the following steps: S1, dissolving cellulose and polyvinylpyrrolidone in a solvent, the solvent is a solution of LiCl in N,N-dimethylacetamide, the mass ratio of LiCl and N,N-dimethylacetamide is 1:11, the mass ratio of polyvinylpyrrolidone and activated cellulose is (5-30):100, to obtain a spinning solution; S2, spinning the spinning solution by a one-step wet spinning method in a first water bath, collecting fibers with a draw ratio of 100%-300% to obtain cellulose-based high-fog-efficiency fibers; S3, immersing the cellulose-based high-fog-efficiency fibers in a mixed solution of activated cellulose and PVDF, the total mass percentage of cellulose and PVDF in the mixed solution is 2%-10%, the solvent is N,N-dimethylacetamide, the mass ratio of cellulose and PVDF is 3:7, the pulling rate is 100-200 mm / min, then performing phase inversion in a second water bath, and drying at room temperature for 45-50 hours, to form a spindle knot on the surface of the cellulose-based high-fog-efficiency fibers, thereby obtaining cellulose-based high-fog-efficiency fibers with a biomimetic spider silk structure; S1 activates the cellulose according to the following process: According to a mass ratio of 1:(10-20), the cellulose is activated in N,N-dimethylacetamide at 60-120°C for 60-120 min, and then dried to complete the activation of the cellulose.

2. The process for preparing a cellulose-based high-capacity mist eliminator fiber according to claim 1, characterized by, S1 obtains the spinning solution according to the following process: First, the activated cellulose is placed in a solution of LiCl in N,N-dimethylacetamide, the mass ratio of activated cellulose and the solution of LiCl in N,N-dimethylacetamide is 1:24, stirring at 55-65°C for 5.5-6.5 h, then adding polyvinylpyrrolidone and continuing to stir for 12-24 h to obtain the spinning solution.

3. The process for preparing a cellulose-based high-capacity mist eliminator fiber according to claim 1, characterized by, The flow rate of the spinning solution in the spinning process of S2 is 2-20 ml / h.

4. A cellulose-based high-fog-efficiency fiber prepared by the method of any one of claims 1-3.

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