Fe2o3 / cement composite material with decoration and energy storage functions

Abstract

The application discloses a Fe2O3 / cement composite material with decoration and energy storage functions, which can be used for preparing daily decorative articles such as mobile phone back plates, watch cases and necklaces and can also be used for energy storage of super capacitors. The Fe2O3 / cement composite material utilizes transition metals and ion defects, reflects 600-800 nm wavelength visible light through ion transition, and absorbs excess visible light, so that an orange-red cement composite material is finally obtained. In combination with excellent mechanical properties (28d compressive strength > 30 MPa), the material can meet the mechanical and optical properties of decorative articles such as mobile phone back plates, watch cases and necklaces. Meanwhile, Fe2O3 is coated in the cement matrix and forms a conductive network, which promotes the migration of ions. With the increase of the content of Fe2O3, the energy storage density and discharge time of the composite material gradually increase. The cement-based super capacitor prepared from the material can accept current charging of different voltage values and light up a bulb and other electrical appliances within a certain time, and has a wide application prospect in the collection of green energy such as tides, solar energy and wind energy.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of new use development of cement-based composite materials, and particularly relates to a Fe2O3 / cement composite material with decoration and energy storage functions. BACKGROUND

[0002] Cement is a kind of artificial composite material, which is rich in resources, low in price and simple to manufacture, and has been widely used in civil engineering and other buildings since its invention. However, cement is mainly used as a building material, and lacks research on the collection of green energy such as wind, sun and tides in daily necessities. Therefore, it is of great significance to develop new uses of cement, energy saving and environmental protection to construct a multifunctional cementitious material with decoration and energy storage functions.

[0003] In recent years, with the improvement of people's living standards, people's demand for decorative items has gradually increased, especially for mobile phone backboards and watch faces and various daily necessities. The current decorations are mainly expensive materials such as pearls, agate and gold, as well as color ceramic or glass materials with complex preparation process and high price. In terms of energy storage, lithium batteries, lead batteries and lead storage batteries are mostly used, which have high manufacturing cost and low mechanical damage resistance. When collecting wind, tides and solar energy in harsh environments, they are prone to damage, which not only increases the cost of collecting solar, tidal and other energy, but also poses a threat to the environment. SUMMARY

[0004] In view of the above problems, the application provides a Fe2O3 / cement composite material with decoration and energy storage functions. The material has two main uses: one is to prepare mobile phone backboards, watch cases, necklaces and other daily decorative items; the other is to prepare supercapacitors for collecting green energy such as wind energy and solar energy.

[0005] The technical scheme of the application is as follows:

[0006] A Fe2O3 / cement composite material with decoration and energy storage functions is prepared by using transition metal oxide (Fe2O3) as a regulating particle in a cement matrix to realize the functions of color development and energy storage of cement materials.

[0007] Fe2O3 / cement composite material utilizes transition metal and ion defects, reflects 600-800nm wavelength visible light through ion transition, and absorbs excess visible light, finally obtains orange red cement composite material, combines excellent mechanical properties (28d compressive strength > 30MPa), and the material can meet the mechanical and optical properties of mobile phone back plate, watch case, necklace and other ornaments. Fe2O3 is coated in the cement matrix and forms a conductive network, promotes the migration of ions, and the energy storage density and discharge time of the composite material gradually increase with the increase of the content of Fe2O3. The cement-based super capacitor prepared from the material can accept current charging of different voltage values, and light a bulb and other electrical appliances in a certain time, and has wide application prospects in collecting green energy such as tide, solar and wind energy.

[0008] The beneficial effects of the present application are:

[0009] The present application discloses a Fe2O3 / cement composite material with decoration and energy storage functions, which utilizes the hydrophobicity of Fe2O3, a small amount of which participates in the hydration reaction, and a large amount of Fe2O3 particles are distributed in the cement matrix, which can change the reflection and absorption of light, make it color, be used for preparing colored mobile phone back plate, watch case and necklace and other daily decorative articles, and provides a new way for the material selection of decorative articles; and can form a conductive network, promote the migration of ions, and improve the energy storage efficiency, and provides a new technology for collecting solar energy, wind energy and tidal energy. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 It is a preparation process and application characteristic diagram of Fe2O3 / cement composite material;

[0011] Figure 2 It is a coloration mechanism diagram of Fe2O3 / cement composite material;

[0012] Figure 3 It is a metallographic diagram of Fe2O3 / cement composite material;

[0013] Figure 4 It is an acoustic emission monitoring diagram in the pre-press forming process of Fe2O3 / cement composite material;

[0014] Figure 5 It is a compressive property diagram of Fe2O3 / cement composite material;

[0015] Figure 6 It is an energy storage characteristic diagram of Fe2O3 / cement composite material;

[0016] Figure 7 It is an application characteristic diagram of cement-based super capacitor prepared from Fe2O3 / cement composite material;

[0017] Figure 8Fig. 1 is a microstructure diagram of a cement composite material with a Fe203 content of 20%. DETAILED DESCRIPTION

[0018] A Fe203 / cement composite material with decoration and energy storage functions, the preparation process comprising the following steps:

[0019] (1) Mix Portland cement and Fe203 in a certain proportion, and mix and bake the mixture according to the ball milling method mentioned in patent CN202211380372.2. After drying, grind in an agate mortar and sieve through a 300-mesh sieve. Add an appropriate amount of alkaline solution (such as saturated KOH solution) to the sieved mixture, and use a gel dropper to granulate according to the proportion of 3 drops of alkaline solution per gram of material.

[0020] (2) After granulation, the mixture is left to stand for about 10 minutes, and then a pre-pressing forming method is used to obtain a Fe203 / cement composite material (forming pressure is 8-10 MPa). The pre-pressing formed cement composite material is soaked in an alkaline solution for hydration and curing at a temperature of 20±5℃.

[0021] (3) Use ultraviolet-visible spectroscopy (UV-Vis) to collect the diffuse reflectance of the color ceramic sample at a speed of 2nm / s between 200nm and 800nm. After calibration with a white silicon oxide sheet as a standard sample, the measurement is performed.

[0022] (4) Put cement and Fe203 in a beaker according to the mass ratio of 4:1, add a certain amount of alkaline solution (mixture: water = 2:1), and put the beaker into an ultrasonic cleaning instrument for ultrasonic dispersion while stirring for more than 15 minutes.

[0023] (5) Paste a copper mesh as an electrode on both ends of the pre-pressing formed cement disc, weld a wire to each end of the electrode, and use the cement slurry obtained in the previous step to encapsulate it. After 24 hours, demold and soak in an alkaline solution at a temperature of 20±5℃ for 28 days to obtain a cement-based supercapacitor.

[0024] Example 1

[0025] (1) Select Fe203 / cement composite materials with different Fe203 contents, and use ultraviolet-visible spectroscopy (UV-Vis) to characterize the color development mechanism of the samples. The results show that with the addition of Fe203, the impurity electrons (Fe 3+) absorb photons from the valence band transition to the conduction band, which is reflected in the spectrum of visible light at a wavelength of 600-800 nm, making the cement composite material present orange red, and with the increase of Fe2O3 content, the reflectivity of visible light at a wavelength of 600-800 nm presents the trend of first increasing and then decreasing, when the Fe2O3 content is 10%, the reflectivity reaches the maximum, as Figure 2 shown.

[0026] (2) The distribution of Fe2O3 in cement was obtained by using MJ33 metallographic microscope, the results showed that Fe2O3 particles were uniformly distributed in the cement matrix, when the doping amount of iron oxide reached 15%, the cement hydration product began to coat a large number of Fe2O3 particles Figure 3 ), metal ions and lattice defects together affect the color development of the composite material.

[0027] Example 2

[0028] (1) The commercial acoustic emission system was used to monitor the real-time dynamic of the preforming process of cement samples under pressure, and the monitoring results are shown in Figure 4 . The results showed that with the increase of Fe2O3 content, the pressure rising time of the measured sample gradually increased, and the acoustic emission signal gradually appeared during the pressure maintaining process. This is because the incorporation of Fe2O3 particles increases the interfacial friction, and the mutual extrusion and combination of metal particles and cement particles lead to the appearance of acoustic emission signal in the pressure maintaining stage.

[0029] (2) By changing the pressure maintaining time, it was found that the acoustic emission signal basically remained unchanged with the increase of pressure maintaining time, as Figure 4 (c), which means that the pressure maintaining time of 60s fully meets the requirements of preforming.

[0030] (3) The mechanical properties of the material were evaluated by using the FBY-D floor type hydraulic testing machine produced by Japan Hitachi Company. The results showed that with the increase of iron oxide content, the 7d compressive strength presented the trend of first decreasing and then increasing, at the same time, the 28d and later compressive strength presented the trend of first increasing and then decreasing, as Figure 5 shown. The 28d compressive strength of all samples was greater than 30MPa, combined with its bright color, it can meet the use requirements of necklace, mobile phone shell, watch chain and other decorations.

[0031] Example 3

[0032] (1) The energy storage properties of Fe2O3 / cement composites were evaluated by electrochemical workstation. The results showed that there were obvious redox peaks on the CV curves, indicating the existence of Faraday redox behavior, which meant that the composite had the characteristics of battery-type supercapacitors. With the increase of Fe2O3 content, the current density of the composite gradually increased. When the content of Fe2O3 was 20%, the current density was the largest, which was 4.27 mV / cm 2 It can also be seen from the figure that the integral area of the CV curve is large, which means that it has a high specific capacity. With the increase of Fe2O3 content, the charging speed gradually decreases, and the discharging time gradually increases, as shown in Figure 6

[0033] (2) The composite material with 20% Fe2O3 content was selected to prepare cement-based supercapacitors, and the charging characteristics were studied by using direct current power. The results showed that with the increase of charging voltage, the time required for the cement-based supercapacitor to be fully charged gradually decreased, and it could successfully light the USB bulb, as shown in Figure 7 This means that the cement-based supercapacitor made of this material can accept the alternating voltage generated by solar energy, tidal energy and wind energy.

[0034] (3) In order to reveal its energy storage mechanism, the microstructure was analyzed by scanning electron microscope. It was found that the Fe2O3 particles inside the cement were directly wrapped by the hydration products, which expanded the ion transfer channel of the material, and a large number of gel holes and capillary holes generated during the hydration process provided space for the alkaline solution, so that it had energy storage properties, as shown in Figure 8

[0035] The remaining matters of the present application are known technologies.

[0036] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.​​

Claims

1. A method for preparing a cement-based supercapacitor, characterized in that: (1) Mix cement and Fe2O3, mix and dry the mixture by ball milling, grind and sieve the dried mixture, add alkaline solution to the sieved mixture for granulation; the mass of Fe2O3 in the cement is 10-20%; (2) After granulation, the mixture is left to stand, and then cement discs containing Fe2O3 conductive network are obtained by pre-pressing and then hydrating and curing. The pre-pressed cement composite material is then immersed in an alkaline solution for hydration and curing. (3) Place cement and Fe2O3 in a beaker, add alkaline solution, and place the beaker in an ultrasonic cleaner to disperse the mixture by stirring and ultrasonication for more than 15 minutes to obtain cement paste; (4) A copper mesh is attached to each end of a cement disc containing an Fe2O3 conductive network as an electrode. A wire is welded to each end of the electrode. The cement slurry obtained in the previous step is used to encapsulate the disc. After demolding, the disc is immersed in an alkaline solution for curing to obtain a cement-based supercapacitor.

2. The preparation method according to claim 1, characterized in that: In step (3), cement and Fe2O3 are placed in a beaker at a mass ratio of 4:1 to form a mixture. The added alkaline solution makes the mass ratio of the mixture to water 2:

1.

3. The preparation method according to claim 1, characterized in that: In step (4), the temperature for curing with alkaline solution is 20±5℃, and the curing time is 28 days.

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