Preparation of photo-thermal-electric heating fabric and application of photo-thermal-electric heating fabric in seawater desalination

Abstract

The invention belongs to the technical field of photo-thermal-electric heating fabrics, and relates to preparation of a photo-thermal-electric heating fabric and application of the photo-thermal-electric heating fabric in seawater desalines.The preparation method comprises the steps that a carbon fiber fabric and a hydrochloric acid solution of a titanium source are mixed and subjected to a hydrothermal reaction, then the mixture is mixed with a photo-thermal polymer monomer, a polymerization reaction is conducted, and the photo-thermal-electric heating fabric is prepared; the photo-thermal-electric heating fabric can be used for seawater desalination. Compared with the prior art, the preparation process of the photo-thermal-electric heating fiber fabric is relatively simple, and the prepared fabric has excellent photo-thermal / electric heating conversion performance and can be applied to all-weather seawater desalination in a weak light or dark environment.

Description

Technical Field

[0001] The invention belongs to the technical field of photothermal-electrical heating fabrics and relates to the preparation of photothermal-electrical heating fabrics and their application in seawater desalination. Background Art

[0002] As we all know, seawater accounts for 96% of the world's total water resources and covers 75% of the earth's surface area. It is one of the most abundant natural resources. Converting seawater into fresh water has become one of the most effective ways to alleviate the freshwater crisis. In order to achieve seawater desalination, people have developed a variety of desalination technologies such as membrane distillation and reverse osmosis. Among them, the use of solar thermal conversion to desalinate seawater has developed rapidly. Its main process is to use light absorbing materials to convert light into heat. After the seawater is heated, it evaporates into steam, and the steam is condensed into fresh water. The core of solar seawater desalination is photothermal materials, which require strong light conditions to achieve a high evaporation efficiency. Due to factors such as region, season or climate, the time when solar energy can be used is limited, and most of the time is in dark or weak light conditions. Therefore, it is of great significance to develop highly conductive photothermal materials. During the day, solar thermal energy is used to evaporate seawater, and at night, power is supplied to the power supply to evaporate seawater using the Joule heating effect, thereby achieving all-weather desalination.

[0003] At present, in order to solve the problem of not being able to evaporate in the dark or weak light conditions, people mostly use highly conductive photothermal materials (graphene, carbon nanotubes and metal nitrides (Mxene)) as core materials to prepare evaporation devices. However, these devices will come into direct contact with water under power conditions, which will cause the problem of water electrolysis, greatly reducing the electrothermal conversion performance and energy utilization efficiency. In addition, the currently commonly used solar desalination evaporation mode is the interface floating mode, which has serious problems such as salt precipitation and heat loss after long-term operation, greatly limiting its practical application. Summary of the invention

[0004] The purpose of the present invention is to provide a preparation and application of a photothermal-electrothermal fiber fabric. By extending photothermal materials and electrical insulating materials onto carbon fiber fabrics, the prepared photothermal-electrothermal fiber fabrics prevent direct contact between electrons and water bodies while retaining the original mechanical properties and electrothermal properties of the carbon fiber fabrics. They can efficiently perform photothermal-electrothermal energy conversion and achieve all-weather evaporation.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] The first aspect of the present invention provides a method for preparing a photothermal-electrical heating fabric, comprising: mixing a carbon fiber fabric with a hydrochloric acid solution of a titanium source, performing a hydrothermal reaction, and then mixing with a photothermal polymer monomer and performing a polymerization reaction to obtain a photothermal-electrical heating fabric.

[0007] The photothermal-electrical heating fabric of the present invention uses carbon fiber as a substrate, and attaches semiconductor insulating materials and photothermal materials to the surface of the substrate in sequence, including:

[0008] (1) A semiconductor nanomaterial is grown on the surface of the carbon fiber by a hydrothermal method as an insulating layer, which effectively inhibits electrons from entering other media from the carbon fiber when the fabric is energized, thus ensuring its excellent electrothermal performance;

[0009] (2) The polymer photothermal material is synthesized on the surface of carbon fiber / semiconductor material by in situ polymerization, giving it excellent photothermal properties.

[0010] Furthermore, the carbon fiber fabric is pretreated before being mixed with the hydrochloric acid solution of the titanium source; the pretreatment comprises: ultrasonically treating the carbon fiber fabric in a mixed solution of ethanol, water and acetone in an equal volume ratio.

[0011] Furthermore, the size of the carbon fiber fabric can be adjusted, and its shape can be changed according to different uses.

[0012] Furthermore, the process of mixing the carbon fiber fabric with the hydrochloric acid solution of the titanium source includes: immersing the carbon fiber fabric in the hydrochloric acid solution of the titanium source for 10 to 40 minutes.

[0013] Furthermore, the titanium source is tetrabutyl titanate.

[0014] Furthermore, in the hydrochloric acid solution of the titanium source, the titanium source concentration is 0.05 to 0.25 mol / L; and the hydrochloric acid concentration is 3.5 to 6.5 mol / L.

[0015] Furthermore, the feed ratio of the carbon fiber fabric to the titanium source is 100-300 mg: 1.5-7.5 mmol.

[0016] Furthermore, in the hydrothermal reaction, the reaction temperature is 100-200° C. and the reaction time is 10-20 h.

[0017] Furthermore, after the hydrothermal reaction, the mixture is repeatedly rinsed with ethanol solution and deionized water and dried at a drying temperature of 40 to 80° C. for a drying time of 6 to 12 hours.

[0018] Furthermore, the photothermal polymer monomer is pyrrole, and the catalyst is ferric chloride.

[0019] Furthermore, in the polymerization reaction, the reaction solvent is ethanol, the pyrrole concentration is 2-8 g / L, and the feed ratio of pyrrole to ferric chloride is 0.1-0.3 mL:1-3 mmol.

[0020] Furthermore, the feed ratio of the carbon fiber fabric to the photothermal polymer monomer is 100-300 mg: 0.1-0.3 mL.

[0021] Furthermore, in the polymerization reaction, the reaction temperature is 0-20°C and the reaction time is 12-24h.

[0022] Furthermore, after the polymerization reaction, the mixture is repeatedly rinsed with ethanol solution and deionized water and dried at a drying temperature of 30 to 60° C. for 4 to 8 hours.

[0023] A second aspect of the present invention provides an application of a photothermal-electrical heating fabric, including using the photothermal-electrical heating fabric for seawater desalination.

[0024] Furthermore, the photothermal-electrothermal fabric can be combined with a phototropic suspension device to form an all-weather solar interface water evaporator.

[0025] Furthermore, the photothermal-electrical heating fiber fabric is applied to a light-oriented suspension device to evaporate seawater under light and / or electricity conditions, thereby realizing continuous production of fresh water around the clock.

[0026] Furthermore, in the illumination, the illumination intensity is 0.5 to 1 W / cm 2 .

[0027] Furthermore, during the power-on, the voltage applied to the photothermal-electrothermal fabric is 1 to 3V.

[0028] The present invention uses a carbon fiber fabric with high conductivity, high mechanical strength and easy modification as the substrate of the photothermal-electrical material, and introduces a semiconductor nanoarray coating with insulating properties as an electrical insulating layer through a hydrothermal method, which prevents electrons from entering the water body and causing electrolysis, thereby ensuring the excellent electric-thermal conversion performance of the composite material; then, a layer of dense photothermal nanoparticles is grown on the surface of the semiconductor material by an in-situ polymerization method, giving the composite material excellent photothermal conversion performance. In addition, the prepared photothermal-electrical fiber fabric is combined with a new type of suspension evaporation mode, which not only maintains the optimal evaporation performance of the photothermal-electrical material, but also realizes efficient non-salting seawater desalination under all-weather conditions such as weak light and darkness.

[0029] Compared with the prior art, the present invention has the following characteristics:

[0030] 1) The present invention provides a method for preparing a photothermal-electrical heating fiber fabric under controllable conditions, which has the characteristics of simple synthesis, high photothermal-electrical heating efficiency, and good mechanical properties;

[0031] 2) The present invention achieves excellent photothermal-to-electrothermal conversion performance and exhibits a high evaporation rate under weak light and dark conditions, providing a feasible approach for obtaining fresh water through all-weather seawater desalination. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1It is a process schematic diagram of a method for preparing an electrothermal-photothermal fiber fabric in the present invention;

[0033] Figure 2 The actual photograph and scanning electron microscope image of an electrothermal-photothermal fiber fabric prepared in Example 1;

[0034] Figure 3 This is a UV-visible-near infrared absorption spectrum of an electrothermal-photothermal fiber fabric prepared in Example 1;

[0035] Figure 4 The photothermal temperature rise diagram and photothermal evaporation performance test of an electrothermal-photothermal fiber fabric prepared in Example 1;

[0036] Figure 5 The electric heating temperature rise diagram and electric heating evaporation performance test of an electric heating-photothermal fiber fabric prepared in Example 1;

[0037] Figure 6 This is a photothermal / electrothermal synergistic temperature rise diagram and photothermal / electrothermal synergistic evaporation performance test of an electrothermal-photothermal fiber fabric prepared in Example 1. DETAILED DESCRIPTION

[0038] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0039] The following are more detailed implementation cases, which further illustrate the technical solutions of the present invention and the technical effects that can be obtained.

[0040] In the following examples, unless otherwise specified, raw materials, reagents or processing techniques are all conventional commercial products or conventional processing techniques in the art.

[0041] Embodiment 1:

[0042] An electrothermal-photothermal fiber fabric, the preparation method of which comprises the following steps:

[0043] S1: 220 mg of carbon fiber fabric was placed in a mixed solution of anhydrous ethanol, acetone and deionized water in an equal volume ratio and ultrasonicated for 40 minutes. After the ultrasonication, it was washed and dried to obtain a pretreated carbon fiber fabric (CFC);

[0044] Tetrabutyl orthotitanate with a final concentration of 0.1 mol / L was added to concentrated hydrochloric acid with a final concentration of about 6.0 mol / L to obtain 30 mL of a mixed solution. After stirring for 30 min, it was placed in a polytetrafluoroethylene-lined autoclave containing pretreated carbon fiber fabrics and placed in an oven. The reaction temperature was set to 160 ° C and the reaction time was set to 16 h. The obtained carbon fiber / titanium dioxide fabric was repeatedly washed with anhydrous ethanol and deionized water, and placed in a 65 ° C oven to dry for 6 h to obtain a carbon fiber / titanium dioxide fabric (CFC / TiO 2 ).

[0045] S2: 0.2 mL of pyrrole monomer was added to 15 mL of ethanol to obtain a mixed solution. After stirring for 30 min, the mixed solution was dripped into a beaker containing carbon fiber / titanium dioxide fabric. Then 15 mL of 0.2 mol / L ferric chloride hexahydrate solution was dripped into the beaker. The beaker was placed in a 0°C refrigerator. After standing for 20 h, the fabric was washed several times with anhydrous ethanol and dried in a 45°C oven for 4 h to obtain carbon fiber / titanium dioxide / polypyrrole electrothermal-photothermal fabric (CFC / TiO 2 / Ppy).

[0046] A process schematic diagram of a method for preparing an electrothermal-photothermal fiber fabric is shown in Figure 1 shown.

[0047] like Figure 2 Shown are actual photos and scanning electron microscope images of the electrothermal-photothermal fiber fabric. The carbon fiber fabric is composed of multiple carbon fibers with smooth surfaces (Figure a), the electrical insulating material is in the form of nanorods evenly distributed on the surface of the carbon fibers (Figure b), and the photothermal material is in the form of nanoparticles attached to the surface of the electrical insulating material (Figure c), proving the successful synthesis of the electrothermal-photothermal fiber fabric.

[0048] like Figure 3 Shown is the UV-Vis-NIR absorption spectrum of the electrothermal-photothermal fiber fabric. The material has excellent solar light absorption performance. The light absorption efficiency of the electrothermal-photothermal fiber fabric can reach 95.5%, which is conducive to achieving high photothermal conversion and improved evaporation efficiency.

[0049] Application Example 1: Photothermal temperature rise diagram and photothermal evaporation performance test of electrothermal-photothermal fiber fabric

[0050] Under the simulated sunlight with a light intensity of one times, the electrothermal-photothermal fiber fabric (CFC / TiO 2 / Ppy) rose from room temperature (26°C) to an equilibrium temperature of 65.3°C in a short period of time (Figure a). Figure 4As shown in a, the electrothermal-photothermal fiber fabric shows excellent photothermal conversion performance. The environmental conditions maintained during the evaporation test: room temperature maintained at about 25°C, humidity: 35% to 50%. The solar seawater evaporation experiments were all completed in a hanging device. The experimental device is shown in Figure 4 As shown in b (refer to the phototropic evaporation device in CN111348708A): two water tanks, one high and one low, are placed horizontally, and the fabric is fixed obliquely between the two tanks, with both ends immersed under the water surface of the tanks on both sides. The evaporation area of ​​the fabric between the two tanks is 6cm 2 , place the whole set of equipment on an electronic balance and record the mass change of the whole set of equipment after different evaporation times. Figure 4 c is the mass loss diagram of the electrothermal-photothermal fiber fabric in simulated seawater. The results show that the fabric has excellent photothermal evaporation performance.

[0051] Application Example 2: Test of the electric heating temperature rise diagram and electric thermal evaporation performance of the electrothermal-photothermal fiber fabric Under the condition of 3V DC voltage regulation, the electrothermal-photothermal fiber fabric (CFC / TiO 2 / Ppy) rose from room temperature (26°C) to an equilibrium temperature of 131.5°C in a short time. Figure 5 As shown in a, the electrothermal-photothermal fiber fabric shows excellent electrothermal heat conversion performance. The environmental conditions maintained during the evaporation test: room temperature maintained at about 25°C, humidity: 35% to 50%. The solar seawater evaporation experiments were all completed in a hanging device. The experimental device is shown in Figure 5 As shown in b (refer to the phototropic evaporation device in CN111348708A, without light): two water tanks, one high and one low, are placed horizontally, and the fabric is fixed obliquely between the two tanks, with both ends immersed under the water surface of the tanks on both sides. The evaporation area of ​​the fabric between the two tanks is 6cm 2 , place the whole set of equipment on an electronic balance and record the mass change of the whole set of equipment after different evaporation times. Figure 5 c is the mass loss diagram of the electrothermal-photothermal fiber fabric in simulated seawater. The results show that the fabric has excellent electrothermal evaporation performance.

[0052] Application Example 3: Photothermal / electrothermal synergistic temperature rise diagram and photothermal / electrothermal synergistic evaporation performance test of electrothermal-photothermal fiber fabric

[0053] At a light intensity of 1 W / cm 2 Under the irradiation of a xenon lamp simulator and a DC regulated power supply with a voltage of 3V, the electrothermal-photothermal fiber fabric (CFC / TiO 2 / Ppy) rises from room temperature (26°C) to an equilibrium temperature of 158°C in a short time ( Figure 6a). Environmental conditions during evaporation test: room temperature maintained at about 25°C, humidity: 35% to 50%. Solar seawater evaporation experiments are all completed in a hanging device. Figure 6 As shown in b (refer to the phototropic evaporation device in CN111348708A): two water tanks, one high and one low, are placed horizontally, and the fabric is fixed obliquely between the two tanks, with both ends immersed under the water surface of the tanks on both sides. The evaporation area of ​​the fabric between the two tanks is 6cm 2 , place the whole set of equipment on an electronic balance and record the mass change of the whole set of equipment after different evaporation times. Figure 6 c is the mass loss diagram of the electrothermal-photothermal fiber fabric in simulated seawater. The results show that the fabric has excellent photothermal and electrothermal thermal evaporation performance.

[0054] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for preparing a photothermal-electric heating fabric, characterized in that: include: The carbon fiber fabric is mixed with a hydrochloric acid solution of a titanium source, and after a hydrothermal reaction, it is mixed with a photothermal polymer monomer and subjected to a polymerization reaction to obtain a photothermal-electrical heating fabric.

2. The method for preparing the photothermal-electric heating fabric according to claim 1, characterized in that: The titanium source is tetrabutyl titanate.

3. The method for preparing the photothermal-electrical heating fabric according to claim 1, characterized in that: In the hydrochloric acid solution of the titanium source, the titanium source concentration is 0.05-0.25 mol / L; and the hydrochloric acid concentration is 3.5-6.5 mol / L.

4. The method for preparing the photothermal-electrical heating fabric according to claim 1, characterized in that: The feeding ratio of the carbon fiber fabric to the titanium source is 100-300 mg: 1.5-7.5 mmol.

5. The method for preparing the photothermal-electrical heating fabric according to claim 1, characterized in that: In the hydrothermal reaction, the reaction temperature is 100-200° C. and the reaction time is 10-20 hours.

6. The method for preparing the photothermal-electrical heating fabric according to claim 1, characterized in that: The photothermal polymer monomer is pyrrole, and the catalyst is ferric chloride.

7. The method for preparing the photothermal-electrical heating fabric according to claim 6, characterized in that: In the polymerization reaction, the reaction solvent is ethanol, the pyrrole concentration is 2-8 g / L, and the feed ratio of pyrrole to ferric chloride is 0.1-0.3 mL:1-3 mmol.

8. The method for preparing the photothermal-electrical heating fabric according to claim 1, characterized in that: The feeding ratio of the carbon fiber fabric to the photothermal polymer monomer is 100-300 mg: 0.1-0.3 mL.

9. The method for preparing the photothermal-electrical heating fabric according to claim 1, characterized in that: In the polymerization reaction, the reaction temperature is 0-20° C. and the reaction time is 12-24 hours.

10. An application of the photothermal-electrical heating fabric prepared by the method according to any one of claims 1 to 9, characterized in that: The photothermal-electric heating fabric is used for seawater desalination.

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