CN108794686A - A kind of preparation method with reversible electrochromism transparent aquagel - Google Patents

Abstract

The invention provides a preparation method of a reversible electrochromic transparent hydrogel. The hydrogel uses deionized water as the solvent, acrylamide as the main monomer, hexadecyl methacrylate as the hydrophobic monomer, sodium lauryl sulfate as the surfactant, lithium chloride as the electrolyte, potassium tartrate As organic salts, hydrogels with reversible electrochromic transparent properties were prepared by radical polymerization. This hydrogel changes from opaque to transparent under conductive conditions, and the light transmittance reaches more than 90%. The hydrogel can return to the original opaque state at room temperature after the electricity is stopped, and the hydrogel can become transparent again when the electricity is continued. Therefore, the present invention has successfully prepared a reversible electrochromic transparent hydrogel.

Description

A kind of preparation method with reversible electrochromic transparent hydrogel

technical field

The invention belongs to the technical field of polymer hydrogels, and in particular relates to a preparation method of transparent hydrogels with reversible electrochromism.

Background technique

Hydrogel is a polymer material with water as the dispersion medium and a three-dimensional network structure. Hydrogels are cross-linked by hydrophilic monomers and hydrophobic monomers to form a network structure. The interaction between the two enables the hydrogel to control water molecules in the network structure, and the hydrophobic groups can Molecules are arranged under action and eventually form a polymer. Because the hydrogel contains a large amount of water, it is soft in nature and has certain deformability and load capacity.

Color change is common in nature, such as chameleons, whose body color changes with the surrounding environment. People are interested in a class of materials with reversible discoloration properties, that is, their color can be changed under certain external conditions and restored under another condition. There are four main types of discoloration phenomena found at present: electrochromism, photochromism, thermochromism and piezochromism, among which electrochromism is the most deeply studied. Electrochromism refers to the phenomenon that materials produce stable and reversible changes under the action of an electric field. In terms of appearance performance, it is manifested as reversible changes in color and transparency. Materials with electrochromic properties are called electrochromic materials. This material is divided into two categories: organic and inorganic. The typical representative of inorganic electrochromic materials is tungsten trioxide. At present, electrochromic devices using WO ₃ as functional materials have been industrialized. The organic electrochromic materials mainly include polythiophenes and their derivatives, viologens, tetrathiafulvalenes, and metal phthalocyanines. Among them, electrochromic materials with viologens as functional materials have been practically applied (Xu Na, Shen Xiaodong, Cui Sheng. Research progress and development prospects of electrochromic materials[J]. Rare Metals, 2010, 34(4) :000610-617.). Kazuhide Ueno et al. controlled the energy level in PBG by changing the periodicity and average dielectric constant of photonic crystals in the gel material, and realized different color displays, and achieved the purpose of mutual conversion of two colors by controlling the direction of conduction ( Ueno K, Matsubara K, Watanabe M, et al. An Electro‐ and Thermochromic Hydrogel as a Full‐Color Indicator[J]. Advanced Materials, 2010, 19(19):2807-2812.). Because the properties of this type of material have extremely special significance in light adjustment, they have a wide range of application prospects in electrochromic smart windows, electrochromic displays, glare-free mirrors, and storage devices. They are used in automotive, aviation, aerospace and other fields It has attracted much attention, and due to the rapid development of artificial intelligence biomimetic materials, the advantages of electrochromic materials are becoming more and more prominent.

At present, electrochromic materials are developing rapidly, but the performance of electrochromic materials is still not ideal, and the cost of such materials is relatively high, which limits the application range of electrochromic materials to a large extent. And research progress, the most important thing is that there are few reports on electrochromic properties in the field of hydrogels and the production process is mostly cumbersome, which is greatly limited in various application fields, so we use free radical polymerization. The electrochromic property is introduced into the hydrogel, so that the hydrogel with reversible electrochromic transparent properties is obtained, which broadens the application prospects of the hydrogel in the related fields of the electrochemical industry, and at the same time provides a basis for the development of electrochromic materials. new ideas.

Contents of the invention

The invention provides a preparation method of a reversible electrochromic transparent hydrogel.

The inventive point of the present invention is that organic salts are introduced into the hydrogel to achieve the purpose of reversible electrochromic transparency.

A kind of preparation method with reversible electrochromic transparent hydrogel provided by the present invention, its steps are as follows:

(1) Prepare mixed solution

The components of deionized water, main monomer, hydrophobic monomer, surfactant, electrolyte, organic salt, oxidizing agent and reducing agent are in mass ratio 100: (19.35-25.8): (0.13-0.22): (0.68- 1.37):(3.22-6.45):(1.61-3.87):(0.13-0.26):(0.11-0.20) mixed evenly to obtain a uniform mixed solution; the main monomer is acrylamide, and the hydrophobic monomer is Cetyl methacrylate, surface active agent is sodium lauryl sulfate, electrolyte is lithium chloride, organic salt is potassium tartrate, oxidizing agent is potassium persulfate, and reducing agent is tetramethylethylenediamine.

(2) Put the homogeneous mixed solution obtained above into a sealed mold for preparing hydrogel, place the mold in an oven, and react at a constant temperature of 35°C for 3-4 hours. After the reaction is completed, cool to room temperature after the reaction to obtain Hydrogel samples.

Beneficial effects: the present invention introduces organic salts into the hydrogel, utilizes the electric heating process when the electricity is applied to change the internal structure of the hydrogel, and the hydrogel changes from an opaque state to a transparent state, and the hydrogel stops After electrification, the original opaque state can be restored at room temperature, and the hydrogel can become transparent again when electrification is applied again. Therefore, the reversible electrochromic transparent property and hydrogel are successfully combined, which broadens the application field of hydrogel in color-changing materials.

Detailed ways

Example 1

(1) Prepare mixed solution

The components of deionized water, main monomer, hydrophobic monomer, surfactant, electrolyte, organic salt, oxidizing agent and reducing agent are: 100g, 19.35g, 0.13g, 0.68g, 3.22g, 1.61g , 0.13g and 0.11g are mixed evenly to obtain a uniform mixed solution; the main monomer is acrylamide, the hydrophobic monomer is cetyl methacrylate, the surfactant is sodium lauryl sulfate, and the electrolyte is Lithium chloride, the organic salt is potassium tartrate, the oxidizing agent is potassium persulfate, and the reducing agent is tetramethylethylenediamine.

(2) Put the homogeneous mixed solution obtained above into a sealed mold for preparing hydrogel, place the mold in an oven, and react at a constant temperature of 35°C for 3-4 hours. After the reaction is completed, cool to room temperature after the reaction to obtain Hydrogel samples.

A hydrogel test sample with a length of 50 mm, a width of 4 mm, and a thickness of 2 mm was prepared, and tested by an ultraviolet-visible spectrophotometer.

The reversible electrochromic transparent hydrogel prepared in Example 1 had a transmittance of 50 before being energized, and a transmittance of 95 after being energized. After being energized and placed at room temperature for one hour, the transmittance was 50, and the transmittance of re-energizing was 95. , the transmittance is 50 after being placed at room temperature for one hour after power-on again.

Example 2

(1) Prepare mixed solution

The components of deionized water, main monomer, hydrophobic monomer, surfactant, electrolyte, organic salt, oxidizing agent and reducing agent are: 100g, 21.62g, 0.13g, 0.92g, 4.54g, 2.62g , 0.18g and 0.16g are mixed evenly to obtain a uniform mixed solution; the main monomer is acrylamide, the hydrophobic monomer is cetyl methacrylate, the surfactant is sodium lauryl sulfate, and the electrolyte is Lithium chloride, the organic salt is potassium tartrate, the oxidizing agent is potassium persulfate, and the reducing agent is tetramethylethylenediamine.

(2) Put the homogeneous mixed solution obtained above into a sealed hydrogel mold, place the mold in an oven, and react at a constant temperature of 35°C for 3-4 hours. After the reaction is complete, cool to room temperature after the reaction to obtain Hydrogel samples.

Using the measurement method in Example 1, the light transmittance of the reversible electrochromic transparent hydrogel prepared in Example 2 was 48 before electrification, and 94 after electrification. The transmittance is 48 after standing for one hour after electrification, and the transmittance is 94 when electrified again. After being powered on again, the transmittance was 94 after standing at room temperature for one hour.

Example 3

(1) Prepare mixed solution

The components of deionized water, main monomer, hydrophobic monomer, surfactant, electrolyte, organic salt, oxidizing agent and reducing agent are: 100g, 23.50g, 0.21g, 1.25g, 4.95g, 3.00g , 0.24g and 0.18g are mixed evenly to obtain a uniform mixed solution; the main monomer is acrylamide, the hydrophobic monomer is cetyl methacrylate, the surfactant is sodium lauryl sulfate, and the electrolyte is Lithium chloride, the organic salt is potassium tartrate, the oxidizing agent is potassium persulfate, and the reducing agent is tetramethylethylenediamine.

(2) Put the homogeneous mixed solution obtained above into a sealed hydrogel mold, place the mold in an oven, and react at a constant temperature of 35°C for 3-4 hours. After the reaction is complete, cool to room temperature after the reaction to obtain Hydrogel samples.

Using the measurement method in Example 1, the transmittance of the reversible electrochromic transparent hydrogel prepared in Example 3 was 34 before electrification, and 93 after electrification. The transmittance is 34 after standing for an hour after electrification, and the transmittance is 93 when electrified again. The transmittance was 34 after being placed at room temperature for one hour after being powered on again.

Example 4

(1) Prepare mixed solution

The components of deionized water, main monomer, hydrophobic monomer, surfactant, electrolyte, organic salt, oxidizing agent and reducing agent are: 100g, 24.32g, 0.15g, 1.32g, 5.85g, 3.20g , 0.24g and 0.18g are mixed uniformly to obtain a uniform mixed solution; the main monomer is acrylamide, the hydrophobic monomer is cetyl methacrylate, the surfactant is sodium lauryl sulfate, and the electrolyte is Lithium chloride, the organic salt is potassium tartrate, the oxidizing agent is potassium persulfate, and the reducing agent is tetramethylethylenediamine.

(2) Put the homogeneous mixed solution obtained above into a sealed mold for preparing hydrogel, place the mold in an oven, and react at a constant temperature of 35°C for 3-4 hours. After the reaction is completed, cool to room temperature after the reaction to obtain Hydrogel samples.

Using the measurement method in Example 1, the transmittance of the reversible electrochromic transparent hydrogel prepared in Example 4 was 32 before electrification, and 93 after electrification. The transmittance is 32 after standing for an hour after electrification, and the transmittance is 93 when electrified again. After being powered on again, the transmittance was 32 after being left at room temperature for one hour.

Example 5

(1) Prepare mixed solution

The components of deionized water, main monomer, hydrophobic monomer, surfactant, electrolyte, organic salt, oxidizing agent and reducing agent are: 100g, 25.80g, 0.22g, 1.37g, 6.45g, 3.87g , 0.26g and 0.20g are mixed evenly to obtain a uniform mixed solution; the main monomer is acrylamide, the hydrophobic monomer is cetyl methacrylate, the surfactant is sodium lauryl sulfate, and the electrolyte is Lithium chloride, the organic salt is potassium tartrate, the oxidizing agent is potassium persulfate, and the reducing agent is tetramethylethylenediamine.

(2) Put the homogeneous mixed solution obtained above into a sealed hydrogel mold, place the mold in an oven, and react at a constant temperature of 35°C for 3-4 hours. After the reaction is complete, cool to room temperature after the reaction to obtain Hydrogel samples.

Using the measurement method in Example 1, the transmittance of the reversible electrochromic transparent hydrogel prepared in Example 5 was 16 before electrification, and 92 after electrification. The transmittance is 16 after standing still for one hour after electrification, and the transmittance is 92 when electrified again. After powering on again, the transmittance was 16 after standing at room temperature for one hour.

Example 6

(1) Prepare mixed solution

The components of deionized water, main monomer, hydrophobic monomer, surfactant, electrolyte, organic salt, oxidizing agent and reducing agent are: 100g, 25.80g, 0.22g, 0.68g, 6.45g, 3.25g , 0.13g and 0.11g are mixed evenly to obtain a uniform mixed solution; the main monomer is acrylamide, the hydrophobic monomer is cetyl methacrylate, the surfactant is sodium lauryl sulfate, and the electrolyte is Lithium chloride, the organic salt is potassium tartrate, the oxidizing agent is potassium persulfate, and the reducing agent is tetramethylethylenediamine.

(2) Put the homogeneous mixed solution obtained above into a sealed hydrogel mold, place the mold in an oven, and react at a constant temperature of 35°C for 3-4 hours. After the reaction is complete, cool to room temperature after the reaction to obtain Hydrogel samples.

Using the measurement method in Example 1, the transmittance of the reversible electrochromic transparent hydrogel prepared in Example 6 was 16 before electrification, and 92 after electrification. The transmittance is 16 after standing still for one hour after electrification, and the transmittance is 92 when electrified again. After powering on again, the transmittance was 16 after standing at room temperature for one hour.

Claims (2)

1. A kind of preparation method with reversible electrochromic transparent hydrogel provided by the present invention, steps and conditions are as follows: (1) Prepare mixed solution The components of deionized water, main monomer, hydrophobic monomer, surfactant, electrolyte, organic salt, oxidizing agent and reducing agent are in mass ratio 100: (19.35-25.8): (0.13-0.22): (0.68- 1.37):(3.22-6.45):(1.61-3.87):(0.13-0.26):(0.11-0.20) mixed evenly to obtain a uniform mixed solution; the main monomer is acrylamide, and the hydrophobic monomer is Cetyl methacrylate, surfactant is sodium lauryl sulfate, electrolyte is lithium chloride, organic salt is potassium tartrate, oxidizing agent is potassium persulfate, reducing agent is tetramethylethylenediamine; (2) Put the homogeneous mixed solution obtained above into a sealed hydrogel mold, place the mold in an oven, and react at a constant temperature of 35°C for 3-4 hours. After the reaction is complete, cool to room temperature after the reaction to obtain Hydrogel samples. 2. The reversible electrochromic transparent hydrogel, the main monomer acrylamide and the hydrophobic monomer hexadecyl methacrylate are copolymerized, and the hydrophobic monomer in the copolymer forms hydrophobic association crosslinking points under the action of an emulsifier A hydrogel is formed, and the change of the aggregation state of the organic salt potassium tartrate in the hydrogel during the power-on and power-off process realizes the electrochromic transparent process.