Ginger waste residue / cellulose electrospun fiber and preparation method thereof

Abstract

The application provides ginger waste residue / cellulose electrostatic spinning fiber and a preparation method thereof. The ginger waste residue / cellulose electrostatic spinning fiber comprises the following components and their weight parts: 4-15 parts of cellulose solution; 1 part of ginger waste residue solution; wherein the solvents of the ginger waste residue solution and the cellulose solution are 1-butyl-3-methyl imidazole acetate salt solutions; the method comprises the following steps: S1, separately preparing ginger waste residue solution and cellulose solution; S2, mixing the ginger waste residue solution and the cellulose solution to prepare an electrostatic spinning solution; S3, preparing ginger waste residue / cellulose fiber by using an electrostatic spinning method; S4, drying the obtained ginger waste residue / cellulose fiber at room temperature after spinning; the application provides a method for preparing a filamentous fiber with large specific surface area and high porosity by using ionic liquid solutions of ginger waste residue and cellulose as raw materials and through an electrostatic spinning technology, and the process is simple; and the ionic liquid has good elution effect and is suitable for large-scale production.

Description

Technical Field

[0001] This invention relates to electrospun fibers from ginger waste / cellulose and their preparation methods, belonging to the field of natural polymer fibers. Background Technology

[0002] Ginger is a traditional natural spice, and its processing generates a large amount of ginger waste, which contains not only abundant biomass resources such as cellulose, but also bioactive small molecules such as gingerol and shogaol. However, current industrial recycling solutions for ginger waste are limited, resulting in a significant waste of biomass resources and putting pressure on the environment. Currently, research on the reuse of spice processing waste in my country is relatively limited, and the technologies are not yet mature. There is an urgent need to develop efficient, green, and safe technologies for reusing spice waste to achieve low-carbon, high-value utilization of spice resources.

[0003] Electrospinning is a special form of electrostatic atomization of polymer fluids. In this process, the atomized material is not split into tiny droplets, but rather into micro-jet streams of polymer that can travel considerable distances before solidifying into fibers. Electrospinning is a specialized fiber manufacturing process where a polymer solution or melt is jetted into fibers within a strong electric field. Under the influence of the electric field, the droplets at the needle tip change from a spherical shape to a conical shape (i.e., a "Taylor cone"), and extend from the tip of the cone to form fine filaments. This method can produce polymer filaments with diameters in the nanometer range.

[0004] Unlike traditional spinning processes, fibers prepared by electrospinning technology have high surface area to volume ratio and high porosity, and have become a general technology for preparing nanofibers and nanofilms from various polymer solutions, sols, gels and composite materials. It has broad application prospects in the preparation of natural polymer materials. Summary of the Invention

[0005] This invention provides a method for preparing filamentous fibers with large specific surface area and high porosity using ionic liquid solutions of ginger waste and cellulose as raw materials through electrospinning technology. The process is simple, and the ionic liquid has good elution effect, making it suitable for large-scale production.

[0006] To achieve this objective, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a ginger waste / cellulose electrospun fiber, the fiber comprising the following components and their parts by weight:

[0008] 4-15 parts cellulose solution;

[0009] One part of ginger waste residue solution;

[0010] The solvent for both the ginger waste solution and the cellulose solution is 1-butyl-3-methylimidazolium acetate solution.

[0011] Preferably, the concentration of the ginger waste residue solution is 2-4 wt%.

[0012] Preferably, the concentration of the cellulose solution is 5-10 wt%.

[0013] In this invention, ginger waste residue is obtained by drying and pulverizing the waste residue after juicing ginger to obtain ginger waste residue powder.

[0014] A second aspect of the present invention provides a method for preparing ginger waste / cellulose electrospun fibers, comprising the following steps:

[0015] S1. Prepare ginger residue solution and cellulose solution separately, and add ginger residue and cellulose to 1-butyl-3-methylimidazolium acetate solution respectively;

[0016] S2. Mix ginger waste residue solution and cellulose solution to prepare electrospinning solution;

[0017] S3. Prepare ginger waste / cellulose fiber by electrospinning;

[0018] S4. After spinning, the resulting ginger waste / cellulose fiber is dried at room temperature.

[0019] Preferably, the electrospinning method includes the following steps:

[0020] S31. Add the electrospinning solution to the syringe and fix the syringe to the injection pump of the electrospinning machine.

[0021] S32. Set the parameters of the electrospinning machine: solution flow rate is 0.08 mL / min, collection distance is 5-10 cm, collection roller speed is 2 rpm / min, and the temperature inside the spinning machine is 40℃.

[0022] S33. Fix the collecting roller on the electrostatic spinning collecting device, and add coagulation bath solution to the water tank under the collecting roller until it covers the bottom of the collecting roller, for fiber coagulation bath;

[0023] S34. After the temperature inside the electrospinning machine stabilizes, adjust the electrospinning voltage until there is a continuous jet.

[0024] Preferably, in step S33, the coagulation bath solution comprises: deionized water and ethanol / isopropanol.

[0025] Preferably, the coagulation bath solution contains a peristaltic pump to achieve dynamic circulation of the coagulation bath solution in the coagulation bath, so as to efficiently and thoroughly wash away the ionic liquid in the ginger residue / cellulose electrospun fibers, and the flow rate of the peristaltic pump is not less than 25 rpm.

[0026] Preferably, in step S1, the method for preparing the ginger waste residue solution includes: drying and pulverizing the waste residue after juicing ginger to obtain ginger waste residue powder; adding the ginger waste residue powder to a 1-butyl-3-methylimidazolium acetate solution and stirring at 90°C for 5 hours to prepare a 2-4 wt% ginger waste residue / 1-butyl-3-methylimidazolium acetate solution.

[0027] Preferably, in step S1, the method for preparing the cellulose solution includes: adding cellulose to a 1-butyl-3-methylimidazolium acetate solution and stirring at 90°C for 5 hours to obtain a 5-10 wt% cellulose / 1-butyl-3-methylimidazolium acetate solution.

[0028] Preferably, in step S2, the weight ratio of cellulose solution to ginger waste residue solution is (4-15):1; more preferably, the weight ratio of cellulose solution to ginger waste residue solution is 15:1, 12:1, 10:1, 9:1, 8:1, 7:1 and 4:1.

[0029] Preferably, the preparation method of ginger waste / cellulose fiber is as follows: The electrospinning solution is added to a 10mL syringe, and the syringe is fixed to the injection pump of the electrospinning machine. The electrospinning machine parameters are set as follows: solution flow rate is 0.08mL / min, collection distance is 5-10cm, collection roller speed is 2rpm / min, and the temperature inside the spinneret is 40℃. A collection roller covered with tin foil is fixed to the electrospinning collection device, and deionized water is added to the water tank below the collection roller until it covers the bottom of the roller. After the temperature inside the electrospinning machine stabilizes, the electrospinning voltage is adjusted to produce a continuous jet using a No. 19 needle. After spinning, the obtained ginger waste / cellulose fiber is dried at room temperature. The liquid in the coagulation bath is passed through a 2000-mesh sieve, and the deionized water in the coagulation bath is removed by rotary evaporation to obtain the recovered ionic liquid.

[0030] Compared with the prior art, the beneficial effects and significant progress of applying the technical solution of the present invention are as follows:

[0031] 1. In the ginger waste residue / cellulose fiber prepared by the present invention, the ginger waste residue is the spice residue after ginger juice extraction; the utilization of ginger waste residue not only realizes the reuse of biomass, but also avoids the harm to the environment caused by the disposal and accumulation of waste residue.

[0032] 2. By using a peristaltic pump, the 1-butyl-3-methylimidazolium acetate eluted from the coagulation bath is discharged, while fresh deionized water is added to maintain a low concentration of 1-butyl-3-methylimidazolium acetate in the coagulation bath. This improves the elution effect of 1-butyl-3-methylimidazolium acetate in ginger waste / cellulose fiber, meeting the needs of large-scale industrial production. The ionic liquid in the coagulation bath can be recycled and reused, effectively reducing production costs. Attached Figure Description

[0033] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below.

[0034] Figure 1 A schematic diagram of the preparation of ginger waste / cellulose fibers by wet electrospinning;

[0035] Figure 2 Scanning electron microscope (SEM) images of electrospun fibers from ginger waste / cellulose at different ratios;

[0036] Figure 3 Fourier transform infrared (FTIR) images of ginger waste residue / cellulose electrospun fibers after elution with different coagulation bath types;

[0037] Figure 4 Images characterizing the tensile strength of electrospun fibers from ginger waste / cellulose with different ratios.

[0038] Figure 5 Fourier transform infrared (FTIR) images of ginger waste / cellulose electrospun fibers prepared under different peristaltic pump flow rates. Detailed Implementation

[0039] The present invention will be further described below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading this invention, those skilled in the art can make various alterations and modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0040] Example 1: Preparation of cellulose / ionic liquid solution

[0041] Experimental steps

[0042] 1.1. Prepare a 10% cellulose / 1-butyl-3-methylimidazolium acetate solution.

[0043] A certain mass of cellulose powder was added to a 1-butyl-3-methylimidazolium acetate solution and stirred at 90°C for 5 hours to prepare a 10 wt% cellulose / 1-butyl-3-methylimidazolium acetate solution (wherein the concentration of cellulose was 10 wt%).

[0044] 1.2. Prepare a 10% cellulose / 1-butyl-3-methylimidazolium chloride solution.

[0045] A certain mass of cellulose powder was added to a 1-butyl-3-methylimidazolium chloride solution and stirred at 90°C for 5 hours to prepare a 10 wt% cellulose / 1-butyl-3-methylimidazolium chloride solution (wherein the concentration of cellulose was 10 wt%).

[0046] 1.3. Prepare a 10% cellulose / 1-decyl-3-methylimidazolium chloride solution.

[0047] A certain mass of cellulose powder was added to a 1-decyl-3-methylimidazolium chloride solution and stirred at 90°C for 5 hours to prepare a 10 wt% cellulose / 1-decyl-3-methylimidazolium chloride solution (wherein the concentration of cellulose was 10 wt%). Ika / Ika viscometer

[0048] 1.4 Observe the solubility of cellulose in ionic liquid and measure the viscosity of 10% cellulose / ionic liquid solution using a viscometer.

[0049] Experimental results

[0050] In a 1-butyl-3-methylimidazolium acetate solution, cellulose is completely dissolved, and the viscosity of a 10 wt% cellulose / 1-butyl-3-methylimidazolium acetate solution at 40°C is 22693 mPa·s.

[0051] In a 1-butyl-3-methylimidazolium chloride solution, cellulose is completely dissolved, and the viscosity of a 10 wt% cellulose / 1-butyl-3-methylimidazolium chloride solution at 40 °C is 162400 mPa·s.

[0052] In the 1-decyl-3-methylimidazolium chloride solution, cellulose was not completely dissolved;

[0053] The 10wt% cellulose / 1-butyl-3-methylimidazolium chloride solution has a high viscosity, making it difficult to achieve the electrospinning process; the solubility of cellulose in the 1-decyl-3-methylimidazolium chloride solution is low; therefore, 1-butyl-3-methylimidazolium acetate was chosen as the final solvent.

[0054] Example 2: Preparation of ginger waste / cellulose electrospun fibers

[0055] like Figure 1 The diagram illustrates the preparation of ginger waste / cellulose fibers using a wet electrospinning method.

[0056] Experimental steps

[0057] 2.1. Prepare a 3% ginger residue / 1-butyl-3-methylimidazolium acetate solution.

[0058] The residue from ginger juice extraction was dried and pulverized to obtain ginger residue powder. A certain mass of ginger residue powder was weighed and added to 1-butyl-3-methylimidazolium acetate, and stirred at 90°C for 5 hours to prepare a 3wt% ginger residue / 1-butyl-3-methylimidazolium acetate solution (wherein, the concentration of ginger residue was 3wt%).

[0059] 2.2 Preparation of 10% cellulose / 1-butyl-3-methylimidazolium acetate solution

[0060] Weigh a certain amount of cellulose powder and add it to a 1-butyl-3-methylimidazolium acetate solution. Stir at 90°C for 5 hours to prepare a 10wt% cellulose / 1-butyl-3-methylimidazolium acetate solution (wherein the concentration of cellulose is 10wt%).

[0061] 2.3 Preparation of electrospinning solution

[0062] The 10wt% cellulose / 1-butyl-3-methylimidazolium acetate solution and the 3wt% ginger waste / 1-butyl-3-methylimidazolium acetate solution prepared above were added to a 100ml beaker at a mass ratio of 9:1 and stirred at 90℃ for 1h to mix well.

[0063] 2.4 Electrospinning for fiber preparation

[0064] 11.29 g of electrospinning solution was added to a 10 ml syringe, and the electrospinning parameters were set as follows: voltage 15.5 kV, collection distance 6 cm, and solution flow rate 0.08 ml / min. After spinning, the fibers were soaked in deionized water for 48 h (coagulation bath) and then dried at room temperature.

[0065] 2.5 Mechanical Strength Test

[0066] The tensile strength (TS) of the film samples was measured using an intelligent electronic tensile testing machine (C610M, Labthink, Jinan, China). The initial clamping distance was 30 mm, the speed was 3 mm / min, and the film was cut into rectangular strips (30 mm × 10 mm) before testing.

[0067] TS(MPa)=Fm / (d×b)

[0068] In the formula, Fm is the maximum tensile force (N) that the film sample can withstand; d is the film width (mm); and b is the film thickness (mm).

[0069] Experimental results

[0070] The tensile strength of the ginger waste / cellulose electrospun fiber prepared in this embodiment was measured to be 2.1408 MPa.

[0071] Example 3: Recovery of Ionic Liquids from Coagulation Bath

[0072] Experimental steps

[0073] The coagulation bath from Example 2 was collected, and the liquid in the coagulation bath was passed through a 2000-mesh sieve. Then, the deionized water in the coagulation bath was removed by rotary evaporation at 90°C and 20 rpm, yielding 8.46 g of recovered ionic liquid.

[0074] Experimental results

[0075] The 11.29 g 9:1 solution contained approximately 10.24 g of 1-butyl-3-methylimidazolium acetate, and the recovery rate of the ionic liquid was approximately 82.62%.

[0076] Example 4: Preparation of electrospun fibers from ginger waste / cellulose in different proportions

[0077] Experimental steps

[0078] The ratio of 10% cellulose / 1-butyl-3-methylimidazolium acetate solution and ginger waste residue / 1-butyl-3-methylimidazolium acetate solution in Example 2 was adjusted as shown in Table 1, while other parameters remained unchanged from Example 2, to obtain ginger waste residue / cellulose electrospun fibers.

[0079] SEM images of ginger waste / cellulose electrospun fibers prepared from mixed solutions of different proportions of 10% cellulose / 1-butyl-3-methylimidazolium acetate solution and ginger waste / 1-butyl-3-methylimidazolium acetate solution are shown below. Figure 2 As shown, from Figure 2 It can be seen that the fiber diameter is uneven; the fiber surface and cross-section are relatively rough, which may be related to the elution of ionic liquid during the spinning process; from the overall morphology, the 9:1 ginger waste residue / cellulose electrospun fiber has fewer liquid droplets and a better overall fiber morphology.

[0080] The performance test results of the ginger waste / cellulose electrospun fibers prepared from mixed solutions of different proportions of 10% cellulose / 1-butyl-3-methylimidazolium acetate solution and ginger waste / 1-butyl-3-methylimidazolium acetate solution are as follows: Figure 4 As shown in Table 1:

[0081] Table 1. Performance test results of ginger waste / cellulose electrospun fibers prepared from mixed solutions of different proportions of 10% cellulose / 1-butyl-3-methylimidazolium acetate solution and ginger waste / 1-butyl-3-methylimidazolium acetate solution.

[0082]

[0083] Note: "—" indicates that tensile strength testing cannot be performed because fibers cannot be formed.

[0084] Example 5: Investigation on the effect of coagulation bath type on the removal of ionic liquids from ginger residue / cellulose electrospun fibers

[0085] In Example 2, the coagulation bath type of the peristaltic pump was adjusted to 20% ethanol, 40% ethanol, and 60% ethanol, respectively. The ethanol was diluted with deionized water. The other parameters remained unchanged from Example 2, and ginger waste residue / cellulose electrospun fibers were obtained.

[0086] Experimental results

[0087] The FTIR spectrum of the obtained ginger waste / cellulose electrospun fibers is shown below. Figure 3 As shown, from Figure 3 It can be seen that when 20% ethanol, 40% ethanol, and 60% ethanol are used as coagulation baths, the fibers reach a coagulation depth of 1567 cm⁻¹. -1 The peaks near the region disappear. 1580-1550cm -1 The peaks in the region were assigned to imidazole ring stretching vibrations, indicating that complete elution of ionic liquids from ginger waste / cellulose electrospun fibers can be maintained when ethanol is used as the coagulation bath.

[0088] Example 6: A method for preparing ginger waste / cellulose electrospun fibers from an effective elution ionized liquid.

[0089] Experimental steps

[0090] 6.1. Prepare a 3% ginger residue / 1-butyl-3-methylimidazolium acetate solution.

[0091] The residue from ginger juice extraction was dried and pulverized to obtain ginger residue powder. A certain mass of ginger residue powder was weighed and added to 1-butyl-3-methylimidazolium acetate, and stirred at 90°C for 5 hours to prepare a 3wt% ginger residue / 1-butyl-3-methylimidazolium acetate solution.

[0092] 6.2. Prepare a 10% cellulose / 1-butyl-3-methylimidazolium acetate solution.

[0093] Weigh a certain amount of cellulose and add it to a 1-butyl-3-methylimidazolium acetate solution. Stir at 90°C for 5 hours to prepare a 10% cellulose / 1-butyl-3-methylimidazolium acetate solution.

[0094] 6.3 Electrospinning Solution

[0095] The 10% cellulose / 1-butyl-3-methylimidazolium acetate solution and the 3% ginger waste / 1-butyl-3-methylimidazolium acetate solution prepared above were added to a 100ml beaker at a mass ratio of 10:1 and stirred at 90℃ for 1 hour to mix well.

[0096] 6.4 Electrospinning for fiber preparation

[0097] The electrospinning solution was added to a 10ml syringe, and the electrospinning parameters were set as follows: voltage 15.5kV, collection distance 6cm, and solution flow rate 0.08ml / min. During the spinning process, a peristaltic pump was added to the coagulation bath, and the flow rate of the peristaltic pump was set to 100rpm to achieve the circulation of deionized water.

[0098] 6.5 Recovery of Ionic Liquids

[0099] After passing the liquid in the coagulation bath through a 2000-mesh sieve, the deionized water in the coagulation bath is removed by rotary evaporation at 90°C and 20 rpm to obtain the recovered ionic liquid.

[0100] Experimental results

[0101] The FTIR spectrum of the obtained ginger waste / cellulose electrospun fibers is shown below. Figure 5 As shown, from Figure 5 It can be seen that under the condition of 100 rpm peristaltic pump, the fiber is at 1567 cm. -1 The peaks near the region disappear. 1580-1550cm -1 The peaks in the region were assigned to the imidazole ring stretching vibration, indicating that the use of a peristaltic pump can maintain a high concentration gradient difference between the coagulation bath and the fibers, thereby improving the elution effect of ionic liquids in nanofibers.

[0102] Example 7: Investigation on the effect of peristaltic pump flow rate on the removal of ionic liquids from ginger residue / cellulose electrospun fibers

[0103] The flow rate of the peristaltic pump in Example 5 was adjusted to 10 rpm, 25 rpm, 50 rpm, 75 rpm, and 100 rpm, while the other parameters remained unchanged from Example 5, to obtain ginger waste residue / cellulose electrospun fibers.

[0104] Experimental results

[0105] The FTIR spectrum of the obtained ginger waste / cellulose electrospun fibers is shown below. Figure 5 As shown, from Figure 5 It can be seen that when the peristaltic pump flow rate is ≥25 rpm, the fiber is at 1567 cm. -1 The peaks near the region disappear. 1580-1550cm -1 The peaks in the region were assigned to the imidazole ring stretching vibration, which indicates that when the peristaltic pump flow rate is ≥25 rpm, a high concentration gradient difference of ionic liquid between the coagulation bath and the fiber can be maintained, thus achieving complete elution of ionic liquid from the nanofiber.

[0106] The applicant declares that, in the process of describing the above-mentioned specification:

[0107] The terms "this embodiment," "an embodiment of the present invention," "as shown," "further," and "further improved technical solutions," etc., indicate that the specific features, structures, materials, or characteristics described in the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms are not necessarily directed at the same embodiment or example, and the specific features, structures, materials, or characteristics described can be combined or combined in any suitable manner in one or more embodiments or examples. Furthermore, without causing contradiction, those skilled in the art can combine or combine the different embodiments or examples described in this specification and the features of the different embodiments or examples.

[0108] Finally, it should be noted that:

[0109] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them;

[0110] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. Non-essential improvements, adjustments or substitutions made by those skilled in the art based on the content of this specification are all within the scope of protection claimed by the present invention.

Claims

1. A ginger waste / cellulose electrospun fiber, characterized in that, The ginger waste residue / cellulose electrospun fiber is prepared from the following raw materials: cellulose solution and ginger waste residue solution, with a weight ratio of ginger waste residue solution to cellulose solution of 1:(7-10), the concentration of ginger waste residue solution is 3wt%, and the concentration of cellulose solution is 10wt%. The solvent for the ginger waste residue solution and the cellulose solution is 1-butyl-3-methylimidazolium acetate solution; The ginger waste / cellulose electrospun fibers are coagulated using a coagulation bath solution during electrospinning. The coagulation bath solution is either deionized water or a mixture of deionized water and ethanol. The ginger residue is the residue after juicing ginger.

2. The method for preparing ginger waste / cellulose electrospun fibers according to claim 1, characterized in that, Includes the following steps: S1. Prepare ginger residue solution and cellulose solution separately; S2. Mix ginger waste residue solution and cellulose solution to prepare electrospinning solution; S3. Prepare ginger waste / cellulose fiber by electrospinning; S4. After spinning, the resulting ginger waste / cellulose fiber is dried at room temperature.

3. The method for preparing ginger waste / cellulose electrospun fibers according to claim 2, characterized in that, The electrospinning method includes the following steps: S31. Add the electrospinning solution to the syringe and fix the syringe to the injection pump of the electrospinning machine. S32. Set the parameters of the electrospinning machine: solution flow rate is 0.08 mL / min, collection distance is 5-10 cm, collection roller speed is 2 rpm / min, and the temperature inside the spinning machine is 40℃. S33. Fix the collecting roller on the electrospinning collecting device, and add coagulation bath solution to the water tank under the collecting roller until it covers the bottom of the collecting roller for fiber coagulation. S34. After the temperature inside the electrospinning machine stabilizes, adjust the electrospinning voltage until there is a continuous jet.

4. The method for preparing ginger waste / cellulose electrospun fibers according to claim 3, characterized in that, The coagulation bath solution contains a peristaltic pump to achieve dynamic circulation of the coagulation bath solution in the coagulation bath, thoroughly washing away the ionic liquid in the ginger residue / cellulose electrospun fibers. The flow rate of the peristaltic pump is not less than 25 rpm.

5. The method for preparing ginger waste / cellulose electrospun fibers according to claim 2, characterized in that, In step S1, the preparation method of ginger waste residue solution includes: drying and pulverizing the waste residue after juicing ginger to obtain ginger waste residue powder; Ginger waste powder was added to a 1-butyl-3-methylimidazolium acetate solution and stirred at 90°C for 5 hours to prepare a ginger waste / 1-butyl-3-methylimidazolium acetate solution.

6. The method for preparing ginger waste / cellulose electrospun fibers according to claim 2, characterized in that, In step S1, the method for preparing the cellulose solution includes: adding cellulose to a 1-butyl-3-methylimidazolium acetate solution and stirring at 90°C for 5 hours to obtain a cellulose / 1-butyl-3-methylimidazolium acetate solution.

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