阅读说明：本技术 一种广波段太阳能吸收偶氮苯光储能材料的制备方法 (Preparation method of wide-waveband solar energy absorption azobenzene optical energy storage material ) 是由 王潮霞 费良 殷允杰 于 2021-08-10 设计创作，主要内容包括：本发明公开了一种广波段太阳能吸收偶氮苯光储能材料的制备方法,将烷氧基偶氮苯和相变材料的混合物与苯乙烯进行混合,加入水、乳化剂和引发剂,在机械力的作用下完成乳化,后加热得到苯乙烯微球；将制备的偶氮苯相变材料微胶囊与纳米铯钨粉共混合,加入水、增稠剂和粘合剂,搅拌制成印花浆料,通过印花的方式作用到纺织品上。本发明制备得到的偶氮苯光储能材料能够吸收紫外光、可见光以及红外光,具有高的太阳能利用率,高的光稳定性以及循环性能,可将其应用于纺织品上,达到可穿戴的太阳能光热转化的目的,实现人体的温度管理。(The invention discloses a preparation method of a wide-waveband solar energy absorption azobenzene optical energy storage material, which comprises the steps of mixing a mixture of alkoxy azobenzene and a phase change material with styrene, adding water, an emulsifier and an initiator, completing emulsification under the action of mechanical force, and heating to obtain styrene microspheres; mixing the prepared azobenzene phase change material microcapsule with nano cesium tungsten powder, adding water, a thickening agent and an adhesive, stirring to prepare printing slurry, and applying the printing slurry to a textile in a printing mode. The azobenzene optical energy storage material prepared by the invention can absorb ultraviolet light, visible light and infrared light, has high solar energy utilization rate, high light stability and cycle performance, can be applied to textiles, achieves the purpose of wearable solar photothermal conversion, and realizes the temperature management of human bodies.)

1. A preparation method of a wide-waveband solar energy absorption azobenzene optical energy storage material is characterized by comprising the following steps:

(1) mixing a mixture of alkoxy azobenzene and a phase-change material with styrene, adding water, an emulsifier and an initiator, completing emulsification under the action of mechanical force, and heating to obtain an azobenzene phase-change material microcapsule;

(2) mixing the prepared azobenzene phase change material microcapsule with nano cesium tungsten powder, adding water, a thickening agent and an adhesive, stirring to prepare printing slurry, and applying the printing slurry to a textile in a printing mode.

2. The method for preparing the wide-band solar energy absorption azobenzene optical energy storage material according to claim 1, wherein the method comprises the following steps: in the step (1), the phase-change material is any one of alkyl alcohol, paraffin, fatty acid or polyethylene glycol.

3. The method for preparing the wide-band solar energy absorption azobenzene optical energy storage material according to claim 1, wherein the method comprises the following steps: in the step (1), in the mixture of the alkoxy azobenzene and the phase-change material, the mass ratio of the alkoxy azobenzene to the phase-change material is 0.1-5: 1.

4. The method for preparing the wide-band solar energy absorption azobenzene optical energy storage material according to claim 1, wherein the method comprises the following steps: in the step (1), the mass ratio of the mixture of the alkoxy azobenzene and the phase-change material to the styrene is 1-10: 1.

5. The method for preparing the wide-band solar energy absorption azobenzene optical energy storage material according to claim 1, wherein the method comprises the following steps: in the step (1), the initiator is an azobisisobutyronitrile substance or a persulfate substance.

6. The method for preparing the wide-band solar energy absorption azobenzene optical energy storage material according to claim 1, wherein the method comprises the following steps: the heating temperature in the step (1) is 30-100 ℃.

7. The method for preparing the wide-band solar energy absorption azobenzene optical energy storage material according to claim 1, wherein the method comprises the following steps: in the step (2), the mass ratio of the azobenzene phase-change material microcapsule to the nano cesium tungsten powder is 20-1: 1.

8. The method for preparing the wide-band solar energy absorption azobenzene optical energy storage material according to claim 1, wherein the method comprises the following steps: in the step (2), the thickener is a natural or synthetic thickener.

9. The method for preparing the wide-band solar energy absorption azobenzene optical energy storage material according to claim 1, wherein the method comprises the following steps: in the step (2), the adhesive is synthetic resin or synthetic rubber.

10. The method for preparing the wide-band solar energy absorption azobenzene optical energy storage material according to claim 1, wherein the method comprises the following steps: in the step (2), the printing mode is flat screen printing or rotary screen printing.

Technical Field

The invention relates to preparation of a fabric, in particular to a preparation method of an energy storage fabric.

Background

Energy management is based on energy storage and release to control the ambient temperature, and can effectively promote energy utilization and promote the development of new energy and environmental heat storage. The storage capacity of latent heat storage can be increased by using Phase Change Materials (PCM), including organic, salt hydrates or alloys. Compared to inorganic PCMs, organic materials generally have cost-effective energy storage, have widely selected crystallization and melting points, and are compatible with the intended applications. When the phase transition temperature is as low as 35-40 ℃, the temperature management of the human body can be realized, and the microenvironment on the surface of the body can be adjusted.

The phase transition is very sensitive to temperature, and the latent heat of the PCM is far away from the environment of the heat source, so that self-heating loss can occur. For this, insertion of an energy barrier into the solid-liquid phase transition can be employed, by the action of intermolecular interactions, and thus the phase transition temperature or latent heat release can be regulated by regulating intermolecular forces such as van der waals forces and hydrogen bonds. Several types of optical switch molecules can achieve control of intermolecular forces, such as dihydroazolene/vinyl heptafluoroethylene coupling, anthracene dimers, and azobenzenes, which undergo reversible structural changes upon continuous absorption of light at two different wavelengths.

The azobenzene molecule changes the physical property through the change of intermolecular force between cis-isomer or trans-isomer, and the control of the phase change point of the phase change material can be realized by doping azobenzene into the phase change material. Meanwhile, azobenzene molecules can be used as solar energy fuel (STF), in order to obtain large energy density, azobenzene derivatives increase energy barrier through close packing, however, the close structure needs to adopt solvents to assist azobenzene charging and discharging energy, and the solvents can cause environmental pollution.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a preparation method of an azobenzene-based optical energy storage fabric, and the prepared azobenzene optical energy storage fabric has high solar energy utilization rate, high light stability and cycle performance and is environment-friendly.

The technical scheme is as follows: the invention relates to a preparation method of an azobenzene optical energy storage fabric, which comprises the following steps:

(1) mixing a mixture of alkoxy azobenzene and a phase-change material with styrene, adding water, an emulsifier and an initiator, completing emulsification under the action of mechanical force, and heating to obtain an azobenzene phase-change material microcapsule;

(2) mixing the prepared azobenzene phase change material microcapsule with nano cesium tungsten powder, adding water, a thickening agent and an adhesive, stirring to prepare printing slurry, and applying the printing slurry to a textile in a printing mode.

Further, in the step (1), the phase change material is any one of alkyl alcohol, paraffin, fatty acid or polyethylene glycol.

Further, in the step (1), in the mixture of the alkoxy azobenzene and the phase-change material, the mass ratio of the alkoxy azobenzene to the phase-change material is 0.1-5: 1.

Further, in the step (1), the mass ratio of the mixture of the alkoxy azobenzene and the phase change material to the styrene is 1-10: 1.

Further, in the step (1), the initiator is an azobisisobutyronitrile substance or a persulfate substance.

Further, the heating temperature in the step (1) is 30-100 ℃.

Further, the mechanical force is one or more of homogenization, ultrasound and mechanical stirring.

Further, in the step (2), the mass ratio of the azobenzene phase-change material microcapsule to the nano cesium tungsten powder is 20-1: 1.

Further, in the step (2), the thickener is a natural or synthetic thickener.

Further, in the step (2), the binder is synthetic resin or synthetic rubber.

Further, in the step (2), the printing mode is flat screen printing or rotary screen printing.

In the step (2), the mass ratio of the azobenzene phase change material microcapsule to the nano cesium tungsten powder is 20-1: 1; the printing mode is flat screen printing or rotary screen printing.

The azobenzene optical energy storage fabric prepared by the invention can indicate energy storage and release application through color, and specifically comprises the following steps: under a certain light source, the alkoxy azobenzene shows a steady state of light, namely a certain proportion of trans-structure and cis-structure is kept, the proportion of the azobenzene with the two structures is different, the azobenzene with the two structures shows different colors, and the change of the cis-trans isomerization proportion of the azobenzene is monitored through the color, so that the charge and discharge energy state and the process of energy are further indicated. Meanwhile, the color change is reversible cycle and can be repeatedly used.

In order to apply the azobenzene phase change material to the fabric, the invention selects the polystyrene as the shell material, and adopts the microcapsule technology to coat the azobenzene phase change material, thereby preventing the leakage in the using process, the polystyrene shell material has better light transmittance, has small influence on the light absorption energy of the azobenzene, and can realize the improvement of the energy storage on the basis of ensuring the coating rate by preferably selecting the proportion of the shell material and the core material.

According to the invention, the nano cesium tungsten powder is introduced into the whole energy storage system, so that the utilization of solar energy spectrum is further promoted, and the absorption of solar energy is improved. The nano cesium tungsten powder can absorb visible light and near infrared light and convert the visible light and the near infrared light into heat, and the heat can be transferred to adjacent azobenzene phase change material microcapsules to generate phase change and store energy. In the exothermic process of azobenzene (cis-form is converted into trans-form), the nano cesium tungsten powder can emit heat under visible light, so that the conversion of azobenzene from cis-form to trans-form is promoted, and the release speed of energy is accelerated. On the other hand, the nano cesium tungsten powder is blue powder, and the color matching effect is generated by combining the blue powder with azobenzene. The azobenzene generates different colors under different illuminations, and when the azobenzene is matched with blue, the color gamut of the azobenzene is increased, so that the colors are easier to distinguish.

The addition of the nano cesium tungsten powder improves the utilization rate of solar spectrum. Under the irradiation of simulated sunlight, the nanometer cesium tungsten powder particles convert light into heat, and the heat is transferred to azobenzene phase change material microcapsules to generate phase change storage energy. And then the azobenzene phase-change material microcapsule can store optical energy in the microcapsule under ultraviolet illumination, the azobenzene structure is converted from a trans form into a cis form, the optical energy is converted into structural energy, and simultaneously the phase-change point of the azobenzene phase-change material is reduced along with the isomerization of azobenzene. Under the blue light or sunlight, azobenzene molecules in the azobenzene phase change material microcapsules are changed into a trans-structure from a cis-structure, the structure in the azobenzene molecules can be released in the form of heat energy, meanwhile, the phase change point is raised, and azobenzene releases phase change energy at a specific temperature. The azobenzene has photochromic performance along with different illumination, and is compounded with blue nano cesium tungsten powder to endow wider color gamut change, so that the azobenzene can be converted between green and yellow, and further accurately monitor energy release.

In the invention, PCM is used as a special solvent, and the charging of azobenzene can be accelerated under the condition of not sacrificing the environmental pressure. However, the solvent has the problem of leakage in the process of reapplication, and the microcapsule can coat the phase change component in the capsule as an effective means, so that the phase change component can be applied to the textile to realize the textile with energy storage performance. The nano cesium tungsten powder is used as a photo-thermal conversion material, can convert visible light parts and near infrared parts in sunlight into heat to be released, is combined with azobenzene phase change material microcapsules, and can transfer the converted heat to the phase change material, so that the effective storage of energy is realized, and meanwhile, the utilization of solar energy spectrums can be improved by adding the nano cesium tungsten powder. Color is a visual expression of information transmission, color change has been applied to specific temperature monitoring in energy release, and monitoring energy state at any given time remains a significant challenge. Therefore, the condition of releasing and storing can be realized by monitoring the color change of the azobenzene based on the azobenzene photochromic performance, so that the optical energy storage textile capable of visually monitoring energy is further constructed.

Has the advantages that:

(1) the azobenzene optical energy storage changing material can act on the fabric through a microcapsule technology on the premise of not influencing optical energy storage, so that the textile with optical energy storage performance is constructed;

(2) by adding nano cesium tungsten powder, the broad-spectrum utilization of solar energy can be realized, and the azobenzene optical energy storage fabric can absorb ultraviolet light, visible light and near infrared light;

(3) the invention realizes the visual monitoring of energy storage; the azobenzene optical energy storage fabric has photochromic performance, so that the azobenzene energy storage and release degree is indicated, and compared with the discoloration of pure azobenzene molecules, the azobenzene optical energy storage fabric has larger color gamut change and more obvious color change.

Drawings

FIG. 1 is a heterogeneous energy release diagram of an azobenzene optical energy storage microcapsule of the invention;

FIG. 2 is a microscopic topography of the azobenzene optical energy storage fabric of the present invention;

FIG. 3 is a chart of the heat of an azobenzene optical energy storage fabric of the present invention under visible light;

FIG. 4 is a schematic diagram of the color change of the azobenzene optical energy storage fabric;

FIG. 5 is a graph showing the relationship between the color and the energy of the azobenzene optical energy storage fabric.

Detailed Description

The present invention will be described in further detail with reference to examples.

The starting materials and reagents used in the following examples are all commercially available.

Preparation of azobenzene-based phase change material microcapsules

Example 1

The method comprises the steps of mixing a tetradecyloxy azobenzene and tetradecanol mixture (the mass ratio is 1: 1) and styrene at the mass ratio of 1:1, adding 10 times of water, an emulsifier (2% wt) and azobenzene diisobutyronitrile (1% wt), completing emulsification under the action of ultrasound, and reacting at 70 ℃ for 6 hours to form the nitrobenzene phase change material microcapsule.

Example 2

Mixing a mixture of octadecyloxyazobenzene and polyethylene glycol 600 (the mass ratio is 1: 5) and styrene at the mass ratio of 1:10, adding 10 times of water, emulsifier (wt.%) and potassium persulfate (1 wt.%), emulsifying under the action of mechanical stirring, and reacting at 40 ℃ for 12h to form the styrene microspheres.

Example 3

Mixing a butane oxy azobenzene and paraffin mixture (the mass ratio is 1: 2) and styrene at the mass ratio of 1:3, adding 10 times of water, an emulsifier (2 percent by weight) and azobisisobutyronitrile (1 percent by weight), completing emulsification under the action of homogenization, and reacting for 8 hours at 75 ℃ to form the styrene microspheres.

Example 4

Mixing a mixture of butane oxy azobenzene and tetradecanol (the mass ratio is 1: 5) and styrene at the mass ratio of 1:15, adding 3 times of water, an emulsifier (3% wt) and azobisisobutyronitrile (1.5% wt), completing emulsification under the action of homogenization, and reacting for 8 hours at 75 ℃ to form the styrene microspheres. As shown in FIG. 1, the azobenzene energy release is only 7J g^-1The temperature is not obviously increased in the practical application process.

Preparation of optical energy storage fabric based on azobenzene

Example 5

The azobenzene phase change material microcapsule prepared in example 1 and nano cesium tungsten powder are blended in a mass ratio of 1:5, 1 volume of water, a thickening agent (0.5% wt) and a binder (0.5% wt) are added, the mixture is fully stirred to prepare printing paste, and the printing paste is applied to a textile in a screen printing manner (as shown in fig. 2). The azobenzene phase change material microcapsule and the nano cesium tungsten powder uniformly act on the surface of the fiber, and the azobenzene phase change material microcapsule and the nano cesium tungsten powder are in contact with each other, so that the azobenzene phase change material microcapsule and the nano cesium tungsten powder are beneficial to the transfer and absorption of heat energy in the photothermal conversion process.

Example 6

The azobenzene phase change material microcapsule prepared in example 2 and nano cesium tungsten powder are blended according to the mass ratio of 1:20, 5 times of water, a thickening agent (2.5 wt%) and an adhesive (2.5 wt%) are added, the mixture is fully stirred to prepare printing paste, and the printing paste is applied to textiles in a rotary screen printing mode. As shown in FIG. 3, the energy storage fabric after charging is irradiated under visible light (AM1.5 light source, 100mW cm)^-2) The temperature can reach 72 ℃ within 220 s.

Application of azobenzene-based optical energy storage fabric in color monitoring energy

Example 7

According to the invention, the azobenzene-based optical energy storage fabric prepared in the embodiment 5 is irradiated under a visible light source, the heating performance of the azobenzene-based optical energy storage fabric is shown in fig. 2, and the generated heat can be phase change of a phase change material, so that the heat is stored. Then irradiating under ultraviolet light, wherein the color of the fabric moves to the red phase along with the ultraviolet light, and under the irradiation of blue light, the color can return to the original state (as shown in figure 4). The ratio of cis-trans isomers of azobenzene can be indicated by the change of color, and the ratio of cis-trans isomers of azobenzene can correspond to the corresponding energy value (as shown in fig. 5).