An asymmetric structure polypyrrole film and a preparation method and application thereof

Abstract

The application discloses an asymmetric structure polypyrrole film and a preparation method and application thereof. A substrate material is repeatedly washed with ethanol and deionized water and dried to obtain a pretreated substrate material; the pretreated substrate material is immersed in a pyrrole solution, the bottom of the substrate material soaked with the pyrrole solution is vertically immersed in a peroxide solution, and then the polymer film is dried to obtain the asymmetric structure polypyrrole film. The asymmetric structure polypyrrole film prepared by the method can play a function under light and without light, has the potential of simultaneously generating steam and electric energy under light, and can output electric energy as an energy generator on a cloudy day or at night.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of functional film material preparation, and particularly relates to an asymmetric structure polypyrrole film and a preparation method and application thereof. BACKGROUND

[0002] Renewable energy technologies have the potential to provide sustainable solutions for the growing clean water and electricity consumption of human society. Solar steam technology and energy generation is an emerging water treatment technology that can effectively address issues such as freshwater resource shortage and energy demand. In recent years, solar photothermal devices have attracted widespread attention due to their simultaneous production of clean water and electricity. Solar steam technology obtains clean water by evaporating seawater, atmosphere and contaminated water sources. Among them, the steam technology with local interfacial heating design improves the energy conversion efficiency in the evaporation system. Previous research work has been invested to maximize the use of full-spectrum solar energy, reduce heat loss, increase capillary water supply, and improve the conversion efficiency of solar energy to steam.

[0003] Although different advanced photothermal materials such as modified graphene, carbonized wood, composite hydrogel and multilayer film have been used to construct interfacial evaporation systems. However, the raw materials of the photothermal layer still face the problems of cost and scalability. In order to be able to simultaneously solve the problems of freshwater resource shortage and energy demand, thermoelectric modules and thermal primary batteries have been integrated into solar-driven interfacial evaporation systems for power generation. In these systems, the rigid solar-to-electricity conversion modules occupy a large part of the space. In addition, the complex packaging of multiple components in the evaporation system raises concerns about possible chemical leaks and long-term reliability. SUMMARY

[0004] The technical problem solved by the present application is to provide an asymmetric structure polypyrrole film with a simple preparation process and easy large-scale preparation, and a preparation method thereof. The asymmetric structure polypyrrole film prepared by the method can function under light and without light, has the potential to simultaneously produce steam and electrical energy under light, can output electrical energy as an energy generator on cloudy days or at night, realizes the maximum utilization of resources through the dual function, and thus can solve the problems of freshwater resource shortage and energy demand.

[0005] The technical problem solved by the present application is to provide an asymmetric structure polypyrrole film with a simple preparation process and easy large-scale preparation, and a preparation method thereof. The asymmetric structure polypyrrole film prepared by the method can function under light and without light, has the potential to simultaneously produce steam and electrical energy under light, can output electrical energy as an energy generator on cloudy days or at night, realizes the maximum utilization of resources through the dual function, and thus can solve the problems of freshwater resource shortage and energy demand.

[0006] Step S1, washing and drying the substrate material with ethanol and deionized water repeatedly to obtain a pretreated substrate material, the substrate material being non-woven fabric, face washing cotton or filter paper;

[0007] Step S2, the pretreated substrate material obtained in step S1 is immersed in a pyrrole solution, and then the bottom of the substrate material infiltrated with the pyrrole solution is vertically immersed in a peroxidation agent solution, so that the peroxidation agent solution is transported upwards along the substrate material by capillary tension to form a gradient polypyrrole film with more polymer content at the lower part of the substrate material and less polymer content at the upper part of the substrate material, wherein the peroxidation agent is one or more of ammonium persulfate or ferric chloride, and then the polymer film is dried to obtain an asymmetric structure polypyrrole film.

[0008] Further, in step S2, the volume ratio of pyrrole to deionized water in the pyrrole solution is 0.05-0.2:1.

[0009] Further, in step S2, the concentration of the peroxidation agent solution is 20-30 mg / mL -1 .

[0010] Further, in step S2, the polymerization reaction temperature is 0-28℃, and the polymerization reaction time is 3-10 min.

[0011] Further, in step S2, the drying temperature is 40-80℃, and the drying time is 1-4 h.

[0012] The asymmetric structure polypyrrole film prepared by the method has the characteristics of the asymmetric structure polypyrrole film.

[0013] The asymmetric structure polypyrrole film can be used in the preparation of energy power generation devices.

[0014] The asymmetric structure polypyrrole film can be used in the preparation of photo-thermal water evaporation devices.

[0015] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0016] 1. The preparation method of the asymmetric structure polypyrrole film is simple, easy to mass-produce, and suitable for industrial production, which can solve the problems of cost and scalability.

[0017] 2. The asymmetric structure polypyrrole film can stably output electric energy when water or brine is added, which can effectively alleviate the energy crisis.

[0018] 3. The asymmetric structure polypyrrole film can realize high evaporation performance by structure regulation of water transmission, and the evaporation rate can reach 2.5 kg / m -2 h -1 .

[0019] 4. The asymmetric structure polypyrrole film can desalinate seawater only by solar energy, which provides a strategy for alleviating water resource shortage. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 SEM image of the low polymerization amount end of the asymmetric structure polypyrrole film;

[0021] Figure 2 SEM image of the low polymerization amount end of the asymmetric structure polypyrrole film;

[0022] Figure 3 XPS image of the non-woven fabric and the asymmetric structure polypyrrole film;

[0023] Figure 4 Voltage output performance graph of the asymmetric structure polypyrrole film prepared by different concentrations of ammonium persulfate when water is added dropwise;

[0024] Figure 5 Current output performance graph of the asymmetric structure polypyrrole film prepared by different concentrations of ammonium persulfate when water is added dropwise;

[0025] Figure 6 Voltage output performance graph of the asymmetric structure polypyrrole film when different amounts of water are added dropwise;

[0026] Figure 7 Current output performance graph of the asymmetric structure polypyrrole film when different amounts of water are added dropwise;

[0027] Figure 8 Voltage output performance comparison graph of the asymmetric structure polypyrrole film in water and salt water;

[0028] Figure 9 Current output performance comparison graph of the asymmetric structure polypyrrole film in water and salt water;

[0029] Figure 10 Evaporation performance graph of the asymmetric structure polypyrrole film in different system structures;

[0030] Figure 11 Surface temperature graph of the asymmetric structure polypyrrole film in different evaporation systems;

[0031] Figure 12 Seawater desalination ion concentration change graph of the asymmetric structure polypyrrole film. DETAILED DESCRIPTION

[0032] The above content of the present application is further described in detail through the following examples, but this should not be understood as limiting the scope of the above subject matter of the present application to only the following examples. Any technology realized based on the above content of the present application falls within the scope of the present application. EXAMPLE

[0033] Get clean, dry non-woven fabric 3 cm * 4 cm, repeatedly washed with ethanol and deionized water 3 times, placed in a drying oven at 60 DEG C to dry to obtain the pretreatment non-woven fabric.

[0034] The pretreatment non-woven fabric is immersed in 0.15 mL of pyrrole solution, the volume ratio of pyrrole to deionized water in the pyrrole solution is 0.1:1, then the non-woven fabric immersed in the pyrrole solution is vertically immersed in 0.15 mL, 25 mg mL -1 of ammonium persulfate solution at the bottom, and polymerized at 20 DEG C for 5 min until the non-woven fabric becomes black, and dried in an oven at 60 DEG C for 2 h to obtain an asymmetric structure polypyrrole film.

[0035] Comparative Example 1

[0036] According to the preparation method of Example 1, except that the concentration of ammonium persulfate solution is changed to 5 mg mL -1 .

[0037] Comparative Example 2

[0038] According to the preparation method of Example 1, except that the concentration of ammonium persulfate solution is changed to 12.5 mg mL -1 .

[0039] Comparative Example 3

[0040] According to the preparation method of Example 1, except that the concentration of ammonium persulfate solution is changed to 37.5 mg mL -1 .

[0041] From Example 1 and Comparative Examples 1-3, it can be seen that different concentrations of peroxidizing agents will first lead to different amounts of polypyrrole obtained, and less amount of polypyrrole cannot completely cover, and more amount of polypyrrole has a thicker thickness. In addition, increasing the concentration of oxidizing agent will also lead to different degrees of polymerization of polypyrrole, and excessive amount will lead to transition polymerization of polypyrrole, which will affect the conductivity. Therefore, the optimal concentration of peroxidizing agent solution is 20-30 mg mL -1 .

[0042] Figure 1 SEM image of the low polymerization amount end of the asymmetric structure polypyrrole film of Example 1. The prepared low polymerization amount end shows that the base material is not completely covered by polypyrrole, and the polypyrrole is a spherical structure.

[0043] Figure 2 SEM image of the high polymerization amount end of the asymmetric structure polypyrrole film of Example 1. The prepared high polymerization amount end of the base material is completely covered by the spherical structure polypyrrole.

[0044] Figure 3The XPS diagram of the non-woven fabric of Example 1 and the high polymerization end of the asymmetric structure polypyrrole film is shown in the figure. The non-woven fabric contains C and O elements, and the high polymerization end of the asymmetric structure polypyrrole film contains C, N, O and S four elements. Example

[0045] The asymmetric structure polypyrrole film prepared in Example 1 and Comparative Examples 1-3 was cut to a size of 1 cm*2.5 cm, at which time one end of the film was darker and the other end was lighter. The voltage and current were tested by connecting the two ends with a conductive electrode, and 20 μL of water was added along the lighter end, while the voltage and current output performance were recorded in real time by a computer.

[0046] Figure 4 The voltage output performance diagram of the asymmetric structure polypyrrole film prepared in Example 1 and Comparative Examples 1-3 when water was added is shown in the figure. It can be seen from the figure that the asymmetric structure polypyrrole film prepared in Example 1 has the highest output voltage compared with the asymmetric structure polypyrrole films prepared in other comparative examples.

[0047] Figure 5 The current output performance diagram of the asymmetric structure polypyrrole film prepared in Example 1 and Comparative Examples 1-3 when water was added is shown in the figure. It can also be seen from the figure that the asymmetric structure polypyrrole film prepared in Example 1 has the highest output current compared with the asymmetric structure polypyrrole films prepared in other comparative examples. Example

[0048] According to the method of Example 2, only the performance of the asymmetric structure polypyrrole film prepared in Example 1 was tested, and the volume of water added was changed to 10 μL. Example

[0049] According to the method of Example 2, only the performance of the asymmetric structure polypyrrole film prepared in Example 1 was tested, and the volume of water added was changed to 30 μL.

[0050] Figure 6 The voltage output performance diagram of Examples 2-4 of the application is shown in the figure. It can be seen from the figure that the asymmetric structure polypyrrole film prepared in Example 1 has the highest output voltage when 20 μL of water is added.

[0051] Figure 7 The current output performance diagram of Examples 2-4 of the application is shown in the figure. It can also be seen from the figure that the asymmetric structure polypyrrole film prepared in Example 3 has the highest output current when 20 μL of water is added.

[0052] In the embodiment of measuring the output current and voltage, the influence of different water amount was compared, 10 µL, 20 µL, 30 µL (Example 2-4). The mechanism of power generation can be explained by the band gap change of polypyrrole surface. When polypyrrole is exposed to air, oxygen molecules are naturally adsorbed on its surface and combine with electrons to form oxygen ions, which increases the concentration of the majority carriers (holes), resulting in the bending of the energy band upwards. When polypyrrole is in contact with water, the oxygen ions on the surface dissolve in water and form hydroxyl ions. The hydroxyl ions adhere to the surface and the holes are trapped. Therefore, the hole concentration on the wet polypyrrole surface is reduced, resulting in the bending of the energy band downwards, thus the difference in carrier concentration (hole concentration) between the wet and dry areas, generating electrical energy. Different amounts of water result in different changes in hole concentration, thus different generation of electrical energy. Example

[0053] According to the method of Example 2, only the performance of the asymmetric structure polypyrrole film prepared in Example 3 was tested, and the water was replaced by a 3wt% sodium chloride solution.

[0054] Figure 8 The voltage output performance chart of Example 2 and 5 of the present application can be seen from the chart, the output voltage of the asymmetric structure polypyrrole film prepared in Example 1 is higher when the salt water is added.

[0055] Figure 9 The current output performance chart of Example 2 and 5 of the present application can also be seen from the chart, the output current of the asymmetric structure polypyrrole film prepared in Example 1 is higher when the salt water is added. Example

[0056] The mass loss of the asymmetric structure polypyrrole film prepared in Example 1 under light was monitored by an electronic balance, including the following steps:

[0057] (1) Turn on the xenon lamp light source, and adjust the light intensity to 1 sun (1 kW m -2 );

[0058] (2) The entire evaporation system includes water containing a beaker, a heat insulation layer, the asymmetric structure polypyrrole film prepared in Example 1, and the height of the asymmetric structure polypyrrole film from the heat insulation layer is adjusted to 2 cm.

[0059] (3) Place the above device on the electronic balance, and use the mass loss of the asymmetric structure polypyrrole film prepared in Example 1. Example

[0060] According to the method of Example 6, only the mass loss of the water containing a beaker was tested as a comparison group. Example 8

[0061] According to the method of Example 6, only the asymmetric structure polypyrrole was replaced by a non-woven fabric. Example

[0062] The method of example 6, only the height of the asymmetric structure of polypyrrole film distance from the heat insulation layer is changed to 0 cm. Example

[0063] The method of example 6, only the height of the asymmetric structure of polypyrrole film distance from the heat insulation layer is changed to 1 cm. Example

[0064] The method of example 6, only the height of the asymmetric structure of polypyrrole film distance from the heat insulation layer is changed to 3 cm.

[0065] The height is adjusted to adjust the water transport rate. In the evaporation process, if the water transport rate is too fast, the interface water will be heated too much, which will slow down the evaporation rate. If the water transport is too slow, the water supply will be insufficient, which will also slow down the water evaporation. Therefore, we adjusted the height of 0 cm, 1 cm, 2 cm, 3 cm (example 6, 9-11), and compared the different performances. Figure 10 The evaporation performance chart of example 6-11 of the present application, from the chart, when the height of the asymmetric structure of polypyrrole film distance from the heat insulation layer is 2 cm, the evaporation performance is the best. Example

[0066] The temperature of the asymmetric structure of polypyrrole film prepared in example 1 under light is monitored by thermocouple, including the following steps:

[0067] (1) Turn on the xenon lamp light source, and adjust the light intensity to 1 sun (1 kW m -2 );

[0068] (2) The whole evaporation system includes water containing beaker, heat insulation layer, asymmetric structure of polypyrrole film prepared in example 1, and the height of the asymmetric structure of polypyrrole film distance from the heat insulation layer is adjusted to 2 cm. Thermocouple is used to monitor the surface temperature change and record in real time. Example

[0069] The method of example 12, only the height of the asymmetric structure of polypyrrole film distance from the heat insulation layer is changed to 0 cm.

[0070] Figure 11 The surface temperature chart of example 12-13 of the present application, when the height of the asymmetric structure of polypyrrole film distance from the heat insulation layer is 2 cm, the surface temperature is lower, which proves that most of the heat is used for evaporation. Example

[0071] ICP analyzer is used to quantitatively analyze the Na + , Ca 2+ , Mg2+ and K + The ion concentration, such as Figure 12 As shown, the Na+ in the purified water obtained through solar steam purification... + Ca 2+ Mg 2+ and K + The ion concentrations were all far lower than the initial concentrations of the corresponding ions in the purified seawater.

[0072] The above embodiments describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are only illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from the scope of the principles of the present invention, and all such changes and modifications fall within the protection scope of the present invention.

Claims

1. A method for preparing a non-symmetrically structured polypyrole film, characterized by The specific steps are as follows: Step S1, the base material is repeatedly washed with ethanol and deionized water and dried to obtain a pretreated base material, which is a non-woven fabric, facial cotton or filter paper; Step S2, immersing the pretreated substrate material obtained in step S1 into a pyrrole solution, and then vertically immersing the bottom of the substrate material infiltrated with the pyrrole solution into a peroxidation agent solution, so that the peroxidation agent solution is transported upward along the substrate material by capillary tension to form a gradient polypyrrole film with more polymer content at the lower part of the substrate material and less polymer content at the upper part of the substrate material, wherein the peroxidation agent is one or more of ammonium persulfate or ferric chloride, and the concentration of the peroxidation agent solution is 20-30 mg / mL -1 After drying the polymer film, an asymmetric structure polypyrrole film is obtained, which can function both in light and in the absence of light, and has the potential to simultaneously generate steam and electrical energy under light, and is used for preparing photo-thermal water evaporation devices and energy power generation devices.

2. The method for preparing the asymmetric polypyrrole membrane according to claim 1, characterized in that: The volume ratio of pyrrole to deionized water in the pyrrole solution in step S2 is 0.05-0.2:

1.

3. The method for preparing the asymmetric polypyrrole membrane according to claim 1, characterized in that: The polymerization reaction temperature in step S2 is 0-28℃, and the polymerization reaction time is 3-10 min.

Images