A spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof

Abstract

The present invention discloses a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof. The method is as follows: immerse the spunbond nonwoven fabric in iron (Fe 3+ )-tannic acid complex solution, taken out and soaked in pyrrole ethanol solution, taken out and soaked in ammonium persulfate aqueous solution, taken out and fully rinsed with deionized water, dried, and the spunbonded nonwoven fabric-based composite fiber membrane is obtained. The method can prepare a spunbonded nonwoven fabric-based composite fiber membrane with a high solar water evaporation rate and seawater desalination rate, does not require a complex synthesis process, has mild preparation conditions, a simple preparation process, low cost, and is easy to achieve quantitative preparation.

Description

Technical Field

[0001] The invention relates to the field of solar seawater desalination, and in particular to a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof. Background Art

[0002] In the 21st century with rapid economic development, the shortage of freshwater resources caused by population explosion and environmental pollution has become one of the important factors restricting the sustainable development of human society. It is estimated that by 2025, 75% of the world's population will face the problem of severe shortage of freshwater resources. At the same time, the depletion of fossil energy has seriously threatened the sustainable development of human society and economy. Therefore, it is urgent to develop and develop a freshwater production technology driven by renewable energy. Solar thermal evaporation technology converts solar energy into thermal energy for water evaporation. It has many advantages such as no restrictions on external energy input, little harm to the environment, and low energy consumption. It shows great application prospects in the field of seawater desalination. This technology makes full use of the two most abundant resources on the earth (seawater and solar energy) and is a green, environmentally friendly and sustainable way to obtain clean water. Through reasonable design and utilization of sunlight to achieve the conversion of solar energy-thermal energy-water vapor-purified water, clean fresh water is finally extracted from seawater.

[0003] The development of efficient and low-cost photothermal conversion materials is the key to promoting the development of solar thermal evaporation technology. For solar thermal evaporation systems, the efficient sunlight absorption, rapid heat localization, excellent hydrophilicity and sufficient porous channels of photothermal conversion materials are the key to achieving efficient, continuous and stable evaporation. Although solar thermal evaporation technology has received more and more attention and has made some phased progress, there are still many challenges in practical applications. For example, photothermal conversion materials are expensive and have complex preparation processes, which limit their large-scale application; photothermal conversion materials have low porosity, insufficient water supply channels, insufficient water supply on the evaporation surface, and it is difficult to continuously generate steam, and the fresh water generation rate is difficult to meet actual needs; the thermal utilization rate of the light absorption layer of the photothermal conversion material is low, and the energy loss is large, resulting in low efficiency of photothermal steam. Therefore, it is necessary to develop low-cost, high-energy-efficiency, and easy-to-prepare solar thermal evaporation materials to meet the practical application needs of future solar seawater desalination and sewage treatment. Summary of the invention

[0004] The purpose of the present invention is to utilize the solar thermal effect to develop a high-efficiency photothermal evaporation seawater desalination technology, and to provide a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof.

[0005] The technical solution of the present invention is as follows:

[0006] A spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof, the preparation method comprising:

[0007] (1) Soak the spunbond nonwoven fabric in iron (Fe 3+ )-tannic acid complex solution for 3 to 30 minutes;

[0008] The spunbonded nonwoven fabric is a kind of polypropylene circular spunbonded nonwoven fabric or polypropylene special-shaped cross-section spunbonded nonwoven fabric;

[0009] The special-shaped cross-section includes a C-shape, a Y-shape, an I-shape, and a cross-shape.

[0010] The method for preparing the iron-tannic acid complex solution is to mix equal volumes of tannic acid ethanol solution and ferric chloride aqueous solution.

[0011] The concentration of the tannic acid ethanol solution is 10-30 mmol / L.

[0012] The concentration of the ferric chloride aqueous solution is 10-50 mmol / L.

[0013] The temperature of the iron-tannic acid complex solution is 10-60° C. More preferably, the soaking condition is: the soaking time is 3-8 minutes.

[0014] (2) taking out the spunbonded nonwoven fabric obtained in step (1), and then soaking it in a pyrrole ethanol solution for 3 to 30 minutes;

[0015] The concentration of the pyrrole ethanol solution is 1-10 mol / L.

[0016] The temperature of the pyrrole ethanol solution is 10 to 60° C. More preferably, the soaking condition is: the soaking time is 3 to 8 minutes.

[0017] (3) taking out the spunbonded nonwoven fabric obtained in step (2), and then soaking it in an aqueous solution of ammonium persulfate for 10 to 60 minutes;

[0018] The concentration of the ammonium persulfate aqueous solution is 0.1-1 mol / L.

[0019] The temperature of the ammonium persulfate aqueous solution is 60 to 80° C. More preferably, the soaking time is 10 to 20 minutes.

[0020] (4) taking out the spunbond nonwoven fabric obtained in step (3), then rinsing it thoroughly with deionized water and air-drying it to obtain the spunbond nonwoven fabric-based composite fiber membrane.

[0021] The present invention provides a spunbond nonwoven fabric-based composite fiber membrane prepared by the above method. The prepared spunbond nonwoven fabric-based composite fiber membrane is black, has full-spectrum solar energy absorption characteristics and excellent photothermal conversion efficiency.

[0022] The spunbonded nonwoven fabric-based composite fiber membrane prepared by the present invention can be applied to fields such as photothermal desalination.

[0023] Compared with the prior art, the characteristics and advantages of the present invention are:

[0024] (1) The present invention provides a spunbonded nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof, wherein the modified coating formed is composed of iron (Fe 3+ )-tannic acid interface layer and polypyrrole photothermal layer, in which iron (Fe 3 + )-tannic acid interface layer preferentially coats the fiber surface, and iron (Fe 3+ The tannic acid interface layer is rich in catechol groups, and its excellent biomimetic adhesive properties can strengthen the interface interaction between the polypyrrole photothermal layer and the fiber and improve the stability of the coating; the polypyrrole photothermal layer is attached to the outer surface of the fiber through the oxidation of pyrrole monomers. 3+ )-Fe in the tannic acid interface layer 3+ and ammonium persulfate synergistically catalyze the self-polymerization of polypyrrole.

[0025] (2) The present invention provides a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof, wherein the spunbond nonwoven fabric has a high specific surface area and can form a photothermal composite layer with higher coverage;

[0026] (3) The present invention provides a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof, wherein the prepared spunbond nonwoven fabric-based composite fiber membrane has a high solar water evaporation rate and seawater desalination rate;

[0027] (4) The present invention provides a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof, wherein the high porosity of the spunbond nonwoven fabric used can form more water supply channels and steam escape channels in the photothermal desalination process;

[0028] (5) The present invention provides a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof, wherein the spunbond nonwoven fabric used has high mechanical strength;

[0029] (6) The present invention provides a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof, wherein the raw materials involved are all general chemicals and do not require a complicated synthesis process;

[0030] (7) The present invention provides a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and a preparation method thereof, which has mild preparation conditions, a simple preparation process, low cost, and is easy to achieve quantitative preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1This is the infrared spectrum of the surface of the spunbond nonwoven fabric-based composite fiber membrane prepared in Example 1.

[0032] Figure 2 This is a scanning electron microscope image of the surface of the spunbond nonwoven fabric-based composite fiber membrane prepared in Example 1.

[0033] Figure 3 This is a scanning electron microscope image of the surface of the spunbond nonwoven fabric-based composite fiber membrane prepared in Example 2.

[0034] Figure 4 This is a scanning electron microscope image of the surface of the spunbond nonwoven fabric-based composite fiber membrane prepared in Example 3.

[0035] Figure 5 This is a comparison chart of the solar water evaporation efficiency of the spunbond nonwoven fabric-based composite fiber membranes prepared in Examples 1, 2, 3, 6, and 7 and the composite fiber membranes prepared in Comparative Examples 1 and 2. DETAILED DESCRIPTION

[0036] The following examples further illustrate the spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination and the preparation method thereof. It should be understood that the following examples are only for specific illustration and do not limit the scope of the present invention. At the same time, obvious changes and modifications made by those skilled in the art according to the present invention are also included in the scope of the present invention.

[0037] Example 1

[0038] In this embodiment, a method for preparing a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination comprises the following steps:

[0039] (1) mixing equal volumes of a 30 mmol / L tannic acid ethanol solution and a 50 mmol / L ferric chloride aqueous solution to obtain an iron-tannic acid complex solution;

[0040] (2) soaking the polypropylene circular spunbond nonwoven fabric in the above-mentioned iron-tannic acid complex solution at a temperature of 20° C. for 5 minutes;

[0041] (3) taking out the spunbonded nonwoven fabric obtained in step (2), and then soaking it in a 10 mol / L pyrrole ethanol solution at a temperature of 20° C. for 5 minutes;

[0042] (4) taking out the spunbonded nonwoven fabric obtained in step (3), and then soaking it in an aqueous solution of ammonium persulfate having a concentration of 0.5 mol / L at a temperature of 60° C. for 10 minutes;

[0043] (5) The spunbond nonwoven fabric obtained in step (4) is thoroughly rinsed with deionized water, taken out and air-dried to obtain the spunbond nonwoven fabric-based composite fiber membrane.

[0044] The spunbonded nonwoven fabric-based composite fiber membrane prepared in Example 1 is labeled as M1, and its surface infrared spectrum is as follows: Figure 1 As shown, M1 at 1170cm -1 、1295cm -1 The CN characteristic peaks belonging to polypyrrole appeared at 1550cm -1 、1030cm -1 The characteristic peaks of phenolic hydroxyl coordinated chelated substituted benzene ring and CO of tannic acid appeared at the position, confirming the successful preparation of the modified coating of spunbond nonwoven fabric-based composite fiber membrane; its surface morphology is as follows Figure 2 As shown in the figure, under the irradiation of 1 sun energy, the membrane surface temperature is 87℃ and the solar water evaporation rate is 3.7kg / m 2 ·h, seawater desalination rate 99.99%.

[0045] Example 2

[0046] In this embodiment, the experimental steps of a method for preparing a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination are the same as those in Example 1, except that the spunbond nonwoven fabric in step (1) is a polypropylene C-section spunbond nonwoven fabric.

[0047] The spunbonded nonwoven fabric-based composite fiber membrane prepared in Example 2 is marked as M2, and its surface morphology is as follows: Figure 3 As shown in the figure, under the irradiation of 1 sun energy, the membrane surface temperature is 89°C and the solar water evaporation rate is 3.8kg / m 2 ·h, seawater desalination rate 99.99%.

[0048] Example 3

[0049] In this embodiment, the experimental steps of a method for preparing a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination are the same as those in Example 1, except that the spunbond nonwoven fabric in step (1) is a polypropylene Y-shaped cross-section spunbond nonwoven fabric.

[0050] The spunbonded nonwoven fabric-based composite fiber membrane prepared in Example 3 is marked as M3, and its surface morphology is as follows: Figure 4 As shown in the figure, under the irradiation of 1 sun energy, the membrane surface temperature is 87℃ and the solar water evaporation rate is 3.6kg / m 2 ·h, seawater desalination rate 99.98%.

[0051] Example 4

[0052] In this embodiment, the experimental steps of a method for preparing a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination are the same as those in Example 1, except that the spunbond nonwoven fabric in step (1) is a polypropylene I-section spunbond nonwoven fabric.

[0053] Example 5

[0054] In this embodiment, the experimental steps of a method for preparing a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination are the same as those in Example 1, except that the spunbond nonwoven fabric in step (1) is a polypropylene cross-section spunbond nonwoven fabric.

[0055] Example 6

[0056] In this embodiment, the experimental steps of a method for preparing a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination are the same as those in Example 2, except that the temperature of the iron-tannic acid complex solution in step (2) is 60°C, the temperature of the pyrrole ethanol solution in step (3) is 60°C, and the temperature of the ammonium persulfate aqueous solution in step (4) is 80°C.

[0057] The spunbonded nonwoven composite fiber membrane prepared in Example 6 is marked as M6. Under the irradiation of 1 sun energy, the membrane surface temperature is 87°C, and the solar water evaporation rate is 3.6 kg / m 2 ·h, seawater desalination rate 99.97%.

[0058] Example 7

[0059] In this embodiment, the experimental steps of a method for preparing a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination are the same as those in Example 1, except that the concentration of the tannic acid ethanol solution in step (1) is 10 mmol / L, the concentration of the ferric chloride aqueous solution is 10 mmol / L, and the concentration of the pyrrole ethanol solution in step (3) is 1 mol / L.

[0060] The spunbonded nonwoven composite fiber membrane prepared in Example 7 is marked as M7. Under the irradiation of 1 sun energy, the membrane surface temperature is 81°C, and the solar water evaporation rate is 3.2 kg / m 2 ·h, seawater desalination rate 99.98%.

[0061] Comparative Example 1

[0062] In this comparative example, the experimental steps of a method for preparing a composite fiber membrane for photothermal desalination are the same as those in Example 1, except that the fiber substrate used in step (1) is a meltblown nonwoven fabric.

[0063] The meltblown nonwoven composite fiber membrane prepared in the above comparative example 1 is marked as CM1. Under the irradiation of 1 sun energy, the membrane surface temperature is 84°C, and the solar water evaporation rate is 2.7 kg / m 2 ·h, seawater desalination rate 99.98%.

[0064] Comparative Example 2

[0065] In this comparative example, the experimental steps of a method for preparing a composite fiber membrane for photothermal desalination are the same as those in Example 1, except that the fiber substrate used in step (1) is cotton fiber cloth.

[0066] The spunbonded nonwoven composite fiber membrane prepared in the above comparative example 1 is marked as CM2. Under the irradiation of 1 sun energy, the membrane surface temperature is 85°C, and the solar water evaporation rate is 2.3 kg / m 2 ·h, seawater desalination rate 99.98%.

Claims

1. A method for preparing a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination, characterized in that: The following steps are involved: (1) Soaking the spunbond nonwoven fabric in an iron-tannic acid complex solution; The spunbonded nonwoven fabric is a kind of polypropylene circular spunbonded nonwoven fabric or polypropylene special-shaped cross-section spunbonded nonwoven fabric; The special-shaped cross section is one of C-shaped, Y-shaped, I-shaped and cross-shaped; The method for preparing the iron-tannic acid complex solution comprises: Mix equal volumes of tannic acid ethanol solution and ferric chloride aqueous solution; Wherein, the concentration of the tannic acid ethanol solution is 10-30 mmol / L, and the concentration of the ferric chloride aqueous solution is 10-50 mmol / L; (2) taking out the spunbonded nonwoven fabric obtained in step (1), and then soaking it in a pyrrole ethanol solution; (3) taking out the spunbonded nonwoven fabric obtained in step (2), and then soaking it in an aqueous solution of ammonium persulfate; (4) The spunbond nonwoven fabric obtained in step (3) is taken out, and then post-processed to obtain a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination.

2. The method for preparing a spunbonded nonwoven fabric-based composite fiber membrane for photothermal desalination according to claim 1, characterized in that: In step (1), the soaking condition is: the temperature is 10~60℃.

3. The method for preparing a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination according to claim 1, characterized in that: In step (2), the concentration of the pyrrole ethanol solution is 1-10 mol / L.

4. The method for preparing a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination according to claim 1, characterized in that: In step (2), the soaking condition is: 10~60℃.

5. The method for preparing a spunbonded nonwoven fabric-based composite fiber membrane for photothermal desalination according to claim 1, characterized in that: In step (3), the concentration of the ammonium persulfate aqueous solution is 0.1-1 mol / L.

6. The method for preparing a spunbonded nonwoven fabric-based composite fiber membrane for photothermal desalination according to claim 1, characterized in that: In step (3), the soaking condition is: the temperature is 60~80℃.

7. The method for preparing a spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination according to claim 1, characterized in that: In step (4), the post-processing includes: Rinse thoroughly with deionized water and allow to dry.

8. A spunbond nonwoven fabric-based composite fiber membrane for photothermal desalination prepared according to the preparation method according to any one of claims 1 to 7.

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